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| author | Rene Mayrhofer <rene@mayrhofer.eu.org> | 2007-01-30 12:21:07 +0000 |
|---|---|---|
| committer | Rene Mayrhofer <rene@mayrhofer.eu.org> | 2007-01-30 12:21:07 +0000 |
| commit | aaa0331ecf95ced1e913ac9be50168cf0e7cbb82 (patch) | |
| tree | 3a86b51b3cb0b5ce596ebd0043af7b3f44384461 /doc | |
| parent | 61aaf3c61a16fb7257ea58f381f3579cea84d9c1 (diff) | |
| download | vyos-strongswan-aaa0331ecf95ced1e913ac9be50168cf0e7cbb82.tar.gz vyos-strongswan-aaa0331ecf95ced1e913ac9be50168cf0e7cbb82.zip | |
[svn-upgrade] Integrating new upstream version, strongswan (2.8.2)
Diffstat (limited to 'doc')
87 files changed, 0 insertions, 64751 deletions
diff --git a/doc/.cvsignore b/doc/.cvsignore deleted file mode 100644 index a523b809d..000000000 --- a/doc/.cvsignore +++ /dev/null @@ -1,66 +0,0 @@ -HowTo.html -HowTo.html -adv_config.html -adv_config.html -background.html -background.html -biblio.html -biblio.html -compat.html -compat.html -config.html -config.html -draft-richardson-ipsec-opportunistic.nr -draft-richardson-ipsec-rr.nr -draft-richardson-ipsec-rr.txt -faq.html -faq.html -firewall.html -firewall.html -glossary.html -glossary.html -index.html -index.html -install.html -install.html -interop.html -interop.html -intro.html -intro.html -ipsec.html -ipsec.html -kernel.html -kernel.html -mail.html -mail.html -makecheck.html -manpage.d -manpage.d -manpages.html -manpages.html -multi_netjig.png -nightly.html -performance.html -performance.html -policygroups.html -politics.html -politics.html -quickstart.html -rfc.html -rfc.html -rfc_pg -roadmap.html -roadmap.html -single_netjig.png -testing.html -testing.html -toc.html -toc.html -trouble.html -trouble.html -umltesting.html -upgrading.html -user_examples.html -user_examples.html -web.html -web.html diff --git a/doc/HowTo.html b/doc/HowTo.html deleted file mode 100644 index a6f92dda9..000000000 --- a/doc/HowTo.html +++ /dev/null @@ -1,18733 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<CENTER><A HREF="#CONTENTS"><H1>Introduction to FreeS/WAN</H1></A><BR> -</CENTER> -<HR> -<H1 ALIGN="CENTER"><A NAME="CONTENTS">Table of Contents</A></H1> -<BR> -<BR><B><A HREF="#intro">Introduction</A></B> -<UL> -<LI><A HREF="#ipsec.intro">IPsec, Security for the Internet Protocol</A></LI> -<UL> -<LI><A HREF="#intro.interop">Interoperating with other IPsec - implementations</A></LI> -<LI><A HREF="#advantages">Advantages of IPsec</A></LI> -<LI><A HREF="#applications">Applications of IPsec</A></LI> -<UL> -<LI><A HREF="#makeVPN">Using secure tunnels to create a VPN</A></LI> -<LI><A HREF="#road.intro">Road Warriors</A></LI> -<LI><A HREF="#opp.intro">Opportunistic encryption</A></LI> -</UL> -<LI><A HREF="#types">The need to authenticate gateways</A></LI> -</UL> -<LI><A HREF="#project">The FreeS/WAN project</A></LI> -<UL> -<LI><A HREF="#goals">Project goals</A></LI> -<LI><A HREF="#staff">Project team</A></LI> -</UL> -<LI><A HREF="#products">Products containing FreeS/WAN</A></LI> -<UL> -<LI><A HREF="#distwith">Full Linux distributions</A></LI> -<LI><A HREF="#kernel_dist">Linux kernel distributions</A></LI> -<LI><A HREF="#office_dist">Office server distributions</A></LI> -<LI><A HREF="#fw_dist">Firewall distributions</A></LI> -<LI><A HREF="#turnkey">Firewall and VPN products</A></LI> -</UL> -<LI><A HREF="#docs">Information sources</A></LI> -<UL> -<LI><A HREF="#docformats">This HowTo, in multiple formats</A></LI> -<LI><A HREF="#rtfm">RTFM (please Read The Fine Manuals)</A></LI> -<LI><A HREF="#text">Other documents in the distribution</A></LI> -<LI><A HREF="#assumptions">Background material</A></LI> -<LI><A HREF="#archives">Archives of the project mailing list</A></LI> -<LI><A HREF="#howto">User-written HowTo information</A></LI> -<LI><A HREF="#applied">Papers on FreeS/WAN</A></LI> -<LI><A HREF="#licensing">License and copyright information</A></LI> -</UL> -<LI><A HREF="#sites">Distribution sites</A></LI> -<UL> -<LI><A HREF="#1_5_1">Primary site</A></LI> -<LI><A HREF="#mirrors">Mirrors</A></LI> -<LI><A HREF="#munitions">The "munitions" archive of Linux crypto - software</A></LI> -</UL> -<LI><A HREF="#1_6">Links to other sections</A></LI> -</UL> -<B><A HREF="#2">Upgrading to FreeS/WAN 2.x</A></B> -<UL> -<LI><A HREF="#2_1">New! Built in Opportunistic connections</A></LI> -<UL> -<LI><A HREF="#2_1_1">Upgrading Opportunistic Encryption to 2.01 (or - later)</A></LI> -</UL> -<LI><A HREF="#2_2">New! Policy Groups</A></LI> -<LI><A HREF="#2_3">New! Packetdefault Connection</A></LI> -<LI><A HREF="#2_4">FreeS/WAN now disables Reverse Path Filtering</A></LI> -<LI><A HREF="#2_5">Revised ipsec.conf</A></LI> -<UL> -<LI><A HREF="#2_5_1">No promise of compatibility</A></LI> -<LI><A HREF="#2_5_2">Most ipsec.conf files will work fine</A></LI> -<LI><A HREF="#2_5_3">Backward compatibility patch</A></LI> -<LI><A HREF="#2_5_4">Details</A></LI> -<LI><A HREF="#2_5_5">Upgrading from 1.x RPMs to 2.x RPMs</A></LI> -</UL> -</UL> -<B><A HREF="#quickstart">Quickstart Guide to Opportunistic Encryption</A> -</B> -<UL> -<LI><A HREF="#opp.setup">Purpose</A></LI> -<UL> -<LI><A HREF="#3_1_1">OE "flag day"</A></LI> -</UL> -<LI><A HREF="#opp.dns">Requirements</A></LI> -<LI><A HREF="#easy.install">RPM install</A></LI> -<UL> -<LI><A HREF="#3_3_1">Download RPMs</A></LI> -<LI><A HREF="#3_3_2">Check signatures</A></LI> -<LI><A HREF="#3_3_3">Install the RPMs</A></LI> -<LI><A HREF="#testinstall">Test</A></LI> -</UL> -<LI><A HREF="#opp.setups.list">Our Opportunistic Setups</A></LI> -<UL> -<LI><A HREF="#3_4_1">Full or partial opportunism?</A></LI> -</UL> -<LI><A HREF="#opp.client">Initiate-only setup</A></LI> -<UL> -<LI><A HREF="#3_5_1">Restrictions</A></LI> -<LI><A HREF="#forward.dns">Create and publish a forward DNS record</A></LI> -<UL> -<LI><A HREF="#3_5_2_1">Find a domain you can use</A></LI> -<LI><A HREF="#3_5_2_2">Choose your ID</A></LI> -<LI><A HREF="#3_5_2_3">Create a forward TXT record</A></LI> -<LI><A HREF="#3_5_2_4">Publish the forward TXT record</A></LI> -</UL> -<LI><A HREF="#3_5_3">Test that your key has been published</A></LI> -<LI><A HREF="#3_5_4">Configure, if necessary</A></LI> -<LI><A HREF="#3_5_5">Test</A></LI> -</UL> -<LI><A HREF="#3_6">Full Opportunism</A></LI> -<UL> -<LI><A HREF="#3_6_1">Put a TXT record in a Forward Domain</A></LI> -<LI><A HREF="#3_6_2">Put a TXT record in Reverse DNS</A></LI> -<UL> -<LI><A HREF="#3_6_2_1">Create a Reverse DNS TXT record</A></LI> -<LI><A HREF="#3_6_2_2">Publish your TXT record</A></LI> -</UL> -<LI><A HREF="#3_6_3">Test your DNS record</A></LI> -<LI><A HREF="#3_6_4">No Configuration Needed</A></LI> -<LI><A HREF="#3_6_5">Consider Firewalling</A></LI> -<LI><A HREF="#3_6_6">Test</A></LI> -<LI><A HREF="#3_6_7">Test</A></LI> -</UL> -<LI><A HREF="#opp.test">Testing opportunistic connections</A></LI> -<LI><A HREF="#3_8">Now what?</A></LI> -<LI><A HREF="#3_9">Notes</A></LI> -<LI><A HREF="#3_10">Troubleshooting OE</A></LI> -<LI><A HREF="#3_11">Known Issues</A></LI> -</UL> -<B><A HREF="#4">How to Configure Linux FreeS/WAN with Policy Groups</A></B> -<UL> -<LI><A HREF="#4_1">What are Policy Groups?</A></LI> -<UL> -<LI><A HREF="#4_1_1">Built-In Security Options</A></LI> -</UL> -<LI><A HREF="#4_2">Using Policy Groups</A></LI> -<UL> -<LI><A HREF="#4_2_1">Example 1: Using a Base Policy Group</A></LI> -<LI><A HREF="#4_2_2">Example 2: Defining IPsec Security Policy with - Groups</A></LI> -<LI><A HREF="#4_2_3">Example 3: Creating a Simple IPsec VPN with the - private Group</A></LI> -<LI><A HREF="#4_2_4">Example 4: New Policy Groups to Protect a Subnet</A> -</LI> -<LI><A HREF="#4_2_5">Example 5: Adding a Subnet to the VPN</A></LI> -</UL> -<LI><A HREF="#4_3">Appendix</A></LI> -<UL> -<LI><A HREF="#4_3_1">Our Hidden Connections</A></LI> -<LI><A HREF="#4_3_2">Custom Policy Groups</A></LI> -<LI><A HREF="#4_3_3">Disabling Opportunistic Encryption</A></LI> -</UL> -</UL> -<B><A HREF="#5">FreeS/WAN FAQ</A></B> -<UL> -<LI><A HREF="#questions">Index of FAQ questions</A></LI> -<LI><A HREF="#whatzit">What is FreeS/WAN?</A></LI> -<LI><A HREF="#problems">How do I report a problem or seek help?</A></LI> -<LI><A HREF="#generic">Can I get ...</A></LI> -<UL> -<LI><A HREF="#lemme_out">Can I get an off-the-shelf system that includes - FreeS/WAN?</A></LI> -<LI><A HREF="#consultant">Can I hire consultants or staff who know - FreeS/WAN?</A></LI> -<LI><A HREF="#commercial">Can I get commercial support?</A></LI> -</UL> -<LI><A HREF="#release">Release questions</A></LI> -<UL> -<LI><A HREF="#rel.current">What is the current release?</A></LI> -<LI><A HREF="#relwhen">When is the next release?</A></LI> -<LI><A HREF="#rel.bugs">Are there known bugs in the current release?</A></LI> -</UL> -<LI><A HREF="#mod_cons">Modifications and contributions</A></LI> -<UL> -<LI><A HREF="#modify.faq">Can I modify FreeS/WAN to ...?</A></LI> -<LI><A HREF="#contrib.faq">Can I contribute to the project?</A></LI> -<LI><A HREF="#ddoc.faq">Is there detailed design documentation?</A></LI> -</UL> -<LI><A HREF="#interact">Will FreeS/WAN work in my environment?</A></LI> -<UL> -<LI><A HREF="#interop.faq">Can FreeS/WAN talk to ...?</A></LI> -<LI><A HREF="#old_to_new">Can different FreeS/WAN versions talk to each - other?</A></LI> -<LI><A HREF="#faq.bandwidth">Is there a limit on throughput?</A></LI> -<LI><A HREF="#faq.number">Is there a limit on number of tunnels?</A></LI> -<LI><A HREF="#faq.speed">Is a ... fast enough to handle FreeS/WAN with - my loads?</A></LI> -</UL> -<LI><A HREF="#work_on">Will FreeS/WAN work on ... ?</A></LI> -<UL> -<LI><A HREF="#versions">Will FreeS/WAN run on my version of Linux?</A></LI> -<LI><A HREF="#nonIntel.faq">Will FreeS/WAN run on non-Intel CPUs?</A></LI> -<LI><A HREF="#multi.faq">Will FreeS/WAN run on multiprocessors?</A></LI> -<LI><A HREF="#k.old">Will FreeS/WAN work on an older kernel?</A></LI> -<LI><A HREF="#k.versions">Will FreeS/WAN run on the latest kernel - version?</A></LI> -<LI><A HREF="#interface.faq">Will FreeS/WAN work on unusual network - hardware?</A></LI> -<LI><A HREF="#vlan">Will FreeS/WAN work on a VLAN (802.1q) network?</A></LI> -</UL> -<LI><A HREF="#features.faq">Does FreeS/WAN support ...</A></LI> -<UL> -<LI><A HREF="#VPN.faq">Does FreeS/WAN support site-to-site VPN (Virtual - Private Network) applications?</A></LI> -<LI><A HREF="#warrior.faq">Does FreeS/WAN support remote users - connecting to a LAN?</A></LI> -<LI><A HREF="#road.shared.possible">Does FreeS/WAN support remote users - using shared secret authentication?</A></LI> -<LI><A HREF="#wireless.faq">Does FreeS/WAN support wireless networks?</A> -</LI> -<LI><A HREF="#PKIcert">Does FreeS/WAN support X.509 or other PKI - certificates?</A></LI> -<LI><A HREF="#Radius">Does FreeS/WAN support user authentication - (Radius, SecureID, Smart Card...)?</A></LI> -<LI><A HREF="#NATtraversal">Does FreeS/WAN support NAT traversal?</A></LI> -<LI><A HREF="#virtID">Does FreeS/WAN support assigning a "virtual - identity" to a remote system?</A></LI> -<LI><A HREF="#noDES.faq">Does FreeS/WAN support single DES encryption?</A> -</LI> -<LI><A HREF="#AES.faq">Does FreeS/WAN support AES encryption?</A></LI> -<LI><A HREF="#other.cipher">Does FreeS/WAN support other encryption - algorithms?</A></LI> -</UL> -<LI><A HREF="#canI">Can I ...</A></LI> -<UL> -<LI><A HREF="#policy.preconfig">Can I use policy groups along with - explicitly configured connections?</A></LI> -<LI><A HREF="#policy.off">Can I turn off policy groups?</A></LI> -<LI><A HREF="#reload">Can I reload connection info without restarting?</A> -</LI> -<LI><A HREF="#masq.faq">Can I use several masqueraded subnets?</A></LI> -<LI><A HREF="#dup_route">Can I use subnets masqueraded to the same - addresses?</A></LI> -<LI><A HREF="#road.masq">Can I assign a road warrior an address on my - net (a virtual identity)?</A></LI> -<LI><A HREF="#road.many">Can I support many road warriors with one - gateway?</A></LI> -<LI><A HREF="#road.PSK">Can I have many road warriors using shared - secret authentication?</A></LI> -<LI><A HREF="#QoS">Can I use Quality of Service routing with FreeS/WAN?</A> -</LI> -<LI><A HREF="#deadtunnel">Can I recognise dead tunnels and shut them - down?</A></LI> -<LI><A HREF="#demanddial">Can I build IPsec tunnels over a demand-dialed - link?</A></LI> -<LI><A HREF="#GRE">Can I build GRE, L2TP or PPTP tunnels over IPsec?</A></LI> -<LI><A HREF="#NetBIOS">... use Network Neighborhood (Samba, NetBIOS) - over IPsec?</A></LI> -</UL> -<LI><A HREF="#setup.faq">Life's little mysteries</A></LI> -<UL> -<LI><A HREF="#cantping">I cannot ping ....</A></LI> -<LI><A HREF="#forever">It takes forever to ...</A></LI> -<LI><A HREF="#route">I send packets to the tunnel with route(8) but they - vanish</A></LI> -<LI><A HREF="#down_route">When a tunnel goes down, packets vanish</A></LI> -<LI><A HREF="#firewall_ate">The firewall ate my packets!</A></LI> -<LI><A HREF="#dropconn">Dropped connections</A></LI> -<LI><A HREF="#defaultroutegone">Disappearing %defaultroute</A></LI> -<LI><A HREF="#tcpdump.faq">TCPdump on the gateway shows strange things</A> -</LI> -<LI><A HREF="#no_trace">Traceroute does not show anything between the - gateways</A></LI> -</UL> -<LI><A HREF="#man4debug">Testing in stages</A></LI> -<UL> -<LI><A HREF="#nomanual">Manually keyed connections don't work</A></LI> -<LI><A HREF="#spi_error">One manual connection works, but second one - fails</A></LI> -<LI><A HREF="#man_no_auto">Manual connections work, but automatic keying - doesn't</A></LI> -<LI><A HREF="#nocomp">IPsec works, but connections using compression - fail</A></LI> -<LI><A HREF="#pmtu.broken">Small packets work, but large transfers fail</A> -</LI> -<LI><A HREF="#subsub">Subnet-to-subnet works, but tests from the - gateways don't</A></LI> -</UL> -<LI><A HREF="#compile.faq">Compilation problems</A></LI> -<UL> -<LI><A HREF="#gmp.h_missing">gmp.h: No such file or directory</A></LI> -<LI><A HREF="#noVM">... virtual memory exhausted</A></LI> -</UL> -<LI><A HREF="#error">Interpreting error messages</A></LI> -<UL> -<LI><A HREF="#route-client">route-client (or host) exited with status 7</A> -</LI> -<LI><A HREF="#unreachable">SIOCADDRT:Network is unreachable</A></LI> -<LI><A HREF="#modprobe">ipsec_setup: modprobe: Can't locate module ipsec</A> -</LI> -<LI><A HREF="#noKLIPS">ipsec_setup: Fatal error, kernel appears to lack - KLIPS</A></LI> -<LI><A HREF="#noDNS">ipsec_setup: ... failure to fetch key for ... from - DNS</A></LI> -<LI><A HREF="#dup_address">ipsec_setup: ... interfaces ... and ... share - address ...</A></LI> -<LI><A HREF="#kflags">ipsec_setup: Cannot adjust kernel flags</A></LI> -<LI><A HREF="#message_num">Message numbers (MI3, QR1, et cetera) in - Pluto messages</A></LI> -<LI><A HREF="#conn_name">Connection names in Pluto error messages</A></LI> -<LI><A HREF="#cantorient">Pluto: ... can't orient connection</A></LI> -<LI><A HREF="#no.interface">... we have no ipsecN interface for either - end of this connection</A></LI> -<LI><A HREF="#noconn">Pluto: ... no connection is known</A></LI> -<LI><A HREF="#nosuit">Pluto: ... no suitable connection ...</A></LI> -<LI><A HREF="#noconn.auth">Pluto: ... no connection has been authorized</A> -</LI> -<LI><A HREF="#noDESsupport">Pluto: ... OAKLEY_DES_CBC is not supported.</A> -</LI> -<LI><A HREF="#notransform">Pluto: ... no acceptable transform</A></LI> -<LI><A HREF="#rsasigkey">rsasigkey dumps core</A></LI> -<LI><A HREF="#sig4">!Pluto failure!: ... exited with ... signal 4</A></LI> -<LI><A HREF="#econnrefused">ECONNREFUSED error message</A></LI> -<LI><A HREF="#no_eroute">klips_debug: ... no eroute!</A></LI> -<LI><A HREF="#SAused">... trouble writing to /dev/ipsec ... SA already - in use</A></LI> -<LI><A HREF="#ignore">... ignoring ... payload</A></LI> -<LI><A HREF="#unknown_rightcert">unknown parameter name "rightcert"</A></LI> -</UL> -<LI><A HREF="#spam">Why don't you restrict the mailing lists to reduce - spam?</A></LI> -</UL> -<B><A HREF="#manpages">FreeS/WAN manual pages</A></B> -<UL> -<LI><A HREF="#man.file">Files</A></LI> -<LI><A HREF="#man.command">Commands</A></LI> -<LI><A HREF="#man.lib">Library routines</A></LI> -</UL> -<B><A HREF="#firewall">FreeS/WAN and firewalls</A></B> -<UL> -<LI><A HREF="#filters">Filtering rules for IPsec packets</A></LI> -<LI><A HREF="#examplefw">Firewall configuration at boot</A></LI> -<UL> -<LI><A HREF="#simple.rules">A simple set of rules</A></LI> -<LI><A HREF="#complex.rules">Other rules</A></LI> -<UL> -<LI><A HREF="#7_2_2_1">Adding additional rules</A></LI> -<LI><A HREF="#7_2_2_2">Modifying existing rules</A></LI> -</UL> -<LI><A HREF="#rules.pub">Published rule sets</A></LI> -<UL> -<LI><A HREF="#Ranch.trinity">Scripts based on Ranch's work</A></LI> -<LI><A HREF="#seawall">The Seattle firewall</A></LI> -<LI><A HREF="#rcf">The RCF scripts</A></LI> -<LI><A HREF="#asgard">Asgard scripts</A></LI> -<LI><A HREF="#user.scripts">User scripts from the mailing list</A></LI> -</UL> -</UL> -<LI><A HREF="#updown">Calling firewall scripts, named in ipsec.conf(5)</A> -</LI> -<UL> -<LI><A HREF="#pre_post">Scripts called at IPsec start and stop</A></LI> -<LI><A HREF="#up_down">Scripts called at connection up and down</A></LI> -<UL> -<LI><A HREF="#fw.default">The default script</A></LI> -<LI><A HREF="#userscript">User-written scripts</A></LI> -</UL> -<LI><A HREF="#ipchains.script">Scripts for ipchains or iptables</A></LI> -</UL> -<LI><A HREF="#NAT">A complication: IPsec vs. NAT</A></LI> -<UL> -<LI><A HREF="#nat_ok">NAT on or behind the IPsec gateway works</A></LI> -<LI><A HREF="#nat_bad">NAT between gateways is problematic</A></LI> -<LI><A HREF="#NAT.ref">Other references on NAT and IPsec</A></LI> -</UL> -<LI><A HREF="#complications">Other complications</A></LI> -<UL> -<LI><A HREF="#through">IPsec through the gateway</A></LI> -<LI><A HREF="#ipsec_only">Preventing non-IPsec traffic</A></LI> -<LI><A HREF="#unknowngate">Filtering packets from unknown gateways</A></LI> -</UL> -<LI><A HREF="#otherfilter">Other packet filters</A></LI> -<UL> -<LI><A HREF="#ICMP">ICMP filtering</A></LI> -<LI><A HREF="#traceroute">UDP packets for traceroute</A></LI> -<LI><A HREF="#l2tp">UDP for L2TP</A></LI> -</UL> -<LI><A HREF="#packets">How it all works: IPsec packet details</A></LI> -<UL> -<LI><A HREF="#noport">ESP and AH do not have ports</A></LI> -<LI><A HREF="#header">Header layout</A></LI> -<LI><A HREF="#dhr">DHR on the updown script</A></LI> -</UL> -</UL> -<B><A HREF="#trouble">Linux FreeS/WAN Troubleshooting Guide</A></B> -<UL> -<LI><A HREF="#overview">Overview</A></LI> -<LI><A HREF="#install">1. During Install</A></LI> -<UL> -<LI><A HREF="#8_2_1">1.1 RPM install gotchas</A></LI> -<LI><A HREF="#8_2_2">1.2 Problems installing from source</A></LI> -<LI><A HREF="#install.check">1.3 Install checks</A></LI> -<LI><A HREF="#oe.trouble">1.3 Troubleshooting OE</A></LI> -</UL> -<LI><A HREF="#negotiation">2. During Negotiation</A></LI> -<UL> -<LI><A HREF="#state">2.1 Determine Connection State</A></LI> -<UL> -<LI><A HREF="#8_3_1_1">Finding current state</A></LI> -<LI><A HREF="#8_3_1_2">What's this supposed to look like?</A></LI> -</UL> -<LI><A HREF="#find.pluto.error">2.2 Finding error text</A></LI> -<UL> -<LI><A HREF="#8_3_2_1">Verbose start for more information</A></LI> -<LI><A HREF="#8_3_2_2">Debug levels count</A></LI> -<LI><A HREF="#8_3_2_3">ipsec barf for lots of debugging information</A></LI> -<LI><A HREF="#8_3_2_4">Find the error</A></LI> -<LI><A HREF="#8_3_2_5">Play both sides</A></LI> -</UL> -<LI><A HREF="#interpret.pluto.error">2.3 Interpreting a Negotiation - Error</A></LI> -<UL> -<LI><A HREF="#ikepath">Connection stuck at STATE_MAIN_I1</A></LI> -<LI><A HREF="#8_3_3_2">Other errors</A></LI> -</UL> -</UL> -<LI><A HREF="#use">3. Using a Connection</A></LI> -<UL> -<LI><A HREF="#8_4_1">3.1 Orienting yourself</A></LI> -<UL> -<LI><A HREF="#8_4_1_1">How do I know if it works?</A></LI> -<LI><A HREF="#8_4_1_2">ipsec barf is useful again</A></LI> -</UL> -<LI><A HREF="#8_4_2">3.2 Those pesky configuration errors</A></LI> -<LI><A HREF="#route.firewall">3.3 Check Routing and Firewalling</A></LI> -<UL> -<LI><A HREF="#8_4_3_1">Background:</A></LI> -<LI><A HREF="#ifconfig">View Interface and Firewall Statistics</A></LI> -</UL> -<LI><A HREF="#sniff">3.4 When in doubt, sniff it out</A></LI> -<UL> -<LI><A HREF="#8_4_4_1">Anticipate your packets' path</A></LI> -</UL> -<LI><A HREF="#find.use.error">3.5 Check your logs</A></LI> -<UL> -<LI><A HREF="#interpret.use.error">Interpreting log text</A></LI> -</UL> -<LI><A HREF="#bigpacket">3.6 More testing for the truly thorough</A></LI> -<UL> -<LI><A HREF="#8_4_6_1">Large Packets</A></LI> -<LI><A HREF="#8_4_6_2">Stress Tests</A></LI> -</UL> -</UL> -<LI><A HREF="#prob.report">4. Problem Reporting</A></LI> -<UL> -<LI><A HREF="#8_5_1">4.1 How to ask for help</A></LI> -<LI><A HREF="#8_5_2">4.2 Where to ask</A></LI> -</UL> -<LI><A HREF="#notes">5. Additional Notes on Troubleshooting</A></LI> -<UL> -<LI><A HREF="#system.info">5.1 Information available on your system</A></LI> -<UL> -<LI><A HREF="#logusage">Logs used</A></LI> -<LI><A HREF="#pages">man pages provided</A></LI> -<LI><A HREF="#statusinfo">Status information</A></LI> -</UL> -<LI><A HREF="#testgates"> 5.2 Testing between security gateways</A></LI> -<LI><A HREF="#ifconfig1">5.3 ifconfig reports for KLIPS debugging</A></LI> -<LI><A HREF="#gdb"> 5.4 Using GDB on Pluto</A></LI> -</UL> -</UL> -<B><A HREF="#compat">Linux FreeS/WAN Compatibility Guide</A></B> -<UL> -<LI><A HREF="#spec">Implemented parts of the IPsec Specification</A></LI> -<UL> -<LI><A HREF="#in">In Linux FreeS/WAN</A></LI> -<LI><A HREF="#dropped">Deliberately omitted</A></LI> -<LI><A HREF="#not">Not (yet) in Linux FreeS/WAN</A></LI> -</UL> -<LI><A HREF="#pfkey">Our PF-Key implementation</A></LI> -<UL> -<LI><A HREF="#pfk.port">PF-Key portability</A></LI> -</UL> -<LI><A HREF="#otherk">Kernels other than the latest 2.2.x and 2.4.y</A></LI> -<UL> -<LI><A HREF="#kernel.2.0">2.0.x kernels</A></LI> -<LI><A HREF="#kernel.production">2.2 and 2.4 kernels</A></LI> -</UL> -<LI><A HREF="#otherdist">Intel Linux distributions other than Redhat</A></LI> -<UL> -<LI><A HREF="#rh7">Redhat 7.0</A></LI> -<LI><A HREF="#suse">SuSE Linux</A></LI> -<UL> -<LI><A HREF="#9_4_2_1">SuSE Linux 5.3</A></LI> -</UL> -<LI><A HREF="#slack">Slackware</A></LI> -<LI><A HREF="#deb">Debian</A></LI> -<LI><A HREF="#caldera">Caldera</A></LI> -</UL> -<LI><A HREF="#CPUs">CPUs other than Intel</A></LI> -<UL> -<LI><A HREF="# strongarm">Corel Netwinder (StrongARM CPU)</A></LI> -<LI><A HREF="#yellowdog">Yellow Dog Linux on Power PC</A></LI> -<LI><A HREF="#mklinux">Mklinux</A></LI> -<LI><A HREF="#alpha">Alpha 64-bit processors</A></LI> -<LI><A HREF="#SPARC">Sun SPARC processors</A></LI> -<LI><A HREF="#mips">MIPS processors</A></LI> -<LI><A HREF="#crusoe">Transmeta Crusoe</A></LI> -<LI><A HREF="#coldfire">Motorola Coldfire</A></LI> -</UL> -<LI><A HREF="#multiprocessor">Multiprocessor machines</A></LI> -<LI><A HREF="#hardware">Support for crypto hardware</A></LI> -<LI><A HREF="#ipv6">IP version 6 (IPng)</A></LI> -<UL> -<LI><A HREF="#v6.back">IPv6 background</A></LI> -</UL> -</UL> -<B><A HREF="#10">Interoperating with FreeS/WAN</A></B> -<UL> -<LI><A HREF="#10_1">Interop at a Glance</A></LI> -<UL> -<LI><A HREF="#10_1_1">Key</A></LI> -</UL> -<LI><A HREF="#10_2">Basic Interop Rules</A></LI> -<LI><A HREF="#10_3">Longer Stories</A></LI> -<UL> -<LI><A HREF="#10_3_1">For More Compatible Implementations</A></LI> -<UL> -<LI><A HREF="#freeswan">FreeS/WAN</A></LI> -<LI><A HREF="#isakmpd">isakmpd (OpenBSD)</A></LI> -<LI><A HREF="#kame">Kame</A></LI> -<LI><A HREF="#mcafee">PGPNet/McAfee</A></LI> -<LI><A HREF="#microsoft">Microsoft Windows 2000/XP</A></LI> -<LI><A HREF="#ssh">SSH Sentinel</A></LI> -<LI><A HREF="#safenet">Safenet SoftPK/SoftRemote</A></LI> -</UL> -<LI><A HREF="#10_3_2">For Other Implementations</A></LI> -<UL> -<LI><A HREF="#6wind">6Wind</A></LI> -<LI><A HREF="#alcatel">Alcatel Timestep</A></LI> -<LI><A HREF="#apple">Apple Macintosh System 10+</A></LI> -<LI><A HREF="#ashleylaurent">AshleyLaurent VPCom</A></LI> -<LI><A HREF="#borderware">Borderware</A></LI> -<LI><A HREF="#checkpoint">Check Point VPN-1 or FW-1</A></LI> -<LI><A HREF="#cisco">Cisco</A></LI> -<LI><A HREF="#equinux">Equinux VPN tracker (for Mac OS X)</A></LI> -<LI><A HREF="#fsecure">F-Secure</A></LI> -<LI><A HREF="#gauntlet">Gauntlet GVPN</A></LI> -<LI><A HREF="#aix">IBM AIX</A></LI> -<LI><A HREF="#as400">IBM AS/400</A></LI> -<LI><A HREF="#intel">Intel Shiva LANRover / Net Structure</A></LI> -<LI><A HREF="#lancom">LanCom (formerly ELSA)</A></LI> -<LI><A HREF="#linksys">Linksys</A></LI> -<LI><A HREF="#lucent">Lucent</A></LI> -<LI><A HREF="#netasq">Netasq</A></LI> -<LI><A HREF="#netcelo">Netcelo</A></LI> -<LI><A HREF="#netgear">Netgear fvs318</A></LI> -<LI><A HREF="#netscreen">Netscreen 100 or 5xp</A></LI> -<LI><A HREF="#nortel">Nortel Contivity</A></LI> -<LI><A HREF="#radguard">Radguard</A></LI> -<LI><A HREF="#raptor">Raptor (NT or Solaris)</A></LI> -<LI><A HREF="#redcreek">Redcreek Ravlin</A></LI> -<LI><A HREF="#sonicwall">SonicWall</A></LI> -<LI><A HREF="#sun">Sun Solaris</A></LI> -<LI><A HREF="#symantec">Symantec</A></LI> -<LI><A HREF="#watchguard">Watchguard Firebox</A></LI> -<LI><A HREF="#xedia">Xedia Access Point/QVPN</A></LI> -<LI><A HREF="#zyxel">Zyxel</A></LI> -</UL> -</UL> -</UL> -<B><A HREF="#performance">Performance of FreeS/WAN</A></B> -<UL> -<LI><A HREF="#pub.bench">Published material</A></LI> -<LI><A HREF="#perf.estimate">Estimating CPU overheads</A></LI> -<UL> -<LI><A HREF="#perf.more">Higher performance alternatives</A></LI> -<LI><A HREF="#11_2_2">Other considerations</A></LI> -</UL> -<LI><A HREF="#biggate">Many tunnels from a single gateway</A></LI> -<LI><A HREF="#low-end">Low-end systems</A></LI> -<LI><A HREF="#klips.bench">Measuring KLIPS</A></LI> -<LI><A HREF="#speed.compress">Speed with compression</A></LI> -<LI><A HREF="#methods">Methods of measuring</A></LI> -</UL> -<B><A HREF="#test.freeswan">Testing FreeS/WAN</A></B> -<UL> -<LI><A HREF="#test.oe">Testing opportunistic connections</A></LI> -<UL> -<LI><A HREF="#12_1_1">Basic OE Test</A></LI> -<LI><A HREF="#12_1_2">OE Gateway Test</A></LI> -<LI><A HREF="#12_1_3">Additional OE tests</A></LI> -</UL> -<LI><A HREF="#test.uml">Testing with User Mode Linux</A></LI> -<LI><A HREF="#testnet">Configuration for a testbed network</A></LI> -<UL> -<LI><A HREF="#testbed">Testbed network</A></LI> -<LI><A HREF="#tcpdump.test">Using packet sniffers in testing</A></LI> -</UL> -<LI><A HREF="#verify.crypt">Verifying encryption</A></LI> -<LI><A HREF="#mail.test">Mailing list pointers</A></LI> -</UL> -<B><A HREF="#kernelconfig">Kernel configuration for FreeS/WAN</A></B> -<UL> -<LI><A HREF="#notall">Not everyone needs to worry about kernel - configuration</A></LI> -<LI><A HREF="#assume">Assumptions and notation</A></LI> -<UL> -<LI><A HREF="#labels">Labels used</A></LI> -</UL> -<LI><A HREF="#kernelopt">Kernel options for FreeS/WAN</A></LI> -</UL> -<B><A HREF="#adv_config">Other configuration possibilities</A></B> -<UL> -<LI><A HREF="#thumb">Some rules of thumb about configuration</A></LI> -<UL> -<LI><A HREF="#cheap.tunnel">Tunnels are cheap</A></LI> -<LI><A HREF="#subnet.size">Subnet sizes</A></LI> -<LI><A HREF="#example.more">Other network layouts</A></LI> -<UL> -<LI><A HREF="#internet.subnet">The Internet as a big subnet</A></LI> -<LI><A HREF="#wireless.config">Wireless</A></LI> -</UL> -</UL> -<LI><A HREF="#choose">Choosing connection types</A></LI> -<UL> -<LI><A HREF="#man-auto">Manual vs. automatic keying</A></LI> -<LI><A HREF="#auto-auth">Authentication methods for auto-keying</A></LI> -<LI><A HREF="#adv-pk">Advantages of public key methods</A></LI> -</UL> -<LI><A HREF="#prodsecrets">Using shared secrets in production</A></LI> -<UL> -<LI><A HREF="#secrets">Putting secrets in ipsec.secrets(5)</A></LI> -<LI><A HREF="#securing.secrets">File security</A></LI> -<LI><A HREF="#notroadshared">Shared secrets for road warriors</A></LI> -</UL> -<LI><A HREF="#prodman">Using manual keying in production</A></LI> -<UL> -<LI><A HREF="#ranbits">Creating keys with ranbits</A></LI> -</UL> -<LI><A HREF="#boot">Setting up connections at boot time</A></LI> -<LI><A HREF="#multitunnel">Multiple tunnels between the same two - gateways</A></LI> -<UL> -<LI><A HREF="#advroute">One tunnel plus advanced routing</A></LI> -</UL> -<LI><A HREF="#opp.gate">An Opportunistic Gateway</A></LI> -<UL> -<LI><A HREF="#14_7_1">Start from full opportunism</A></LI> -<LI><A HREF="#14_7_2">Reverse DNS TXT records for each protected machine</A> -</LI> -<LI><A HREF="#14_7_3">Publish your records</A></LI> -<LI><A HREF="#14_7_4">...and test them</A></LI> -<LI><A HREF="#14_7_5">No Configuration Needed</A></LI> -</UL> -<LI><A HREF="#extruded.config">Extruded Subnets</A></LI> -<LI><A HREF="#roadvirt">Road Warrior with virtual IP address</A></LI> -<LI><A HREF="#dynamic">Dynamic Network Interfaces</A></LI> -<UL> -<LI><A HREF="#basicdyn">Basics</A></LI> -<LI><A HREF="#bootdyn">Boot Time</A></LI> -<LI><A HREF="#changedyn">Change Time</A></LI> -</UL> -<LI><A HREF="#unencrypted">Unencrypted tunnels</A></LI> -</UL> -<B><A HREF="#install">Installing FreeS/WAN</A></B> -<UL> -<LI><A HREF="#15_1">Requirements</A></LI> -<LI><A HREF="#15_2">Choose your install method</A></LI> -<LI><A HREF="#15_3">FreeS/WAN ships with some Linuxes</A></LI> -<UL> -<LI><A HREF="#15_3_1">FreeS/WAN may be altered...</A></LI> -<LI><A HREF="#15_3_2">You might need to create an authentication keypair</A> -</LI> -<LI><A HREF="#15_3_3">Start and test FreeS/WAN</A></LI> -</UL> -<LI><A HREF="#15_4">RPM install</A></LI> -<UL> -<LI><A HREF="#15_4_1">Download RPMs</A></LI> -<LI><A HREF="#15_4_2">For freeswan.org RPMs: check signatures</A></LI> -<LI><A HREF="#15_4_3">Install the RPMs</A></LI> -<LI><A HREF="#15_4_4">Start and Test FreeS/WAN</A></LI> -</UL> -<LI><A HREF="#15_5">Install from Source</A></LI> -<UL> -<LI><A HREF="#15_5_1">Decide what functionality you need</A></LI> -<LI><A HREF="#15_5_2">Download FreeS/WAN</A></LI> -<LI><A HREF="#15_5_3">For freeswan.org source: check its signature</A></LI> -<LI><A HREF="#15_5_4">Untar, unzip</A></LI> -<LI><A HREF="#15_5_5">Patch if desired</A></LI> -<LI><A HREF="#15_5_6">... and Make</A></LI> -<UL> -<LI><A HREF="#15_5_6_1">Userland-only Install for 2.6 kernels</A></LI> -<LI><A HREF="#15_5_6_2">KLIPS install for 2.2, 2.4, or 2.6 kernels</A></LI> -</UL> -</UL> -<LI><A HREF="#15_6">Start FreeS/WAN and test your install</A></LI> -<LI><A HREF="#15_7">Test your install</A></LI> -<LI><A HREF="#15_8">Making FreeS/WAN play well with others</A></LI> -<LI><A HREF="#15_9">Configure for your needs</A></LI> -</UL> -<B><A HREF="#config">How to configure FreeS/WAN</A></B> -<UL> -<LI><A HREF="#16_1">Requirements</A></LI> -<LI><A HREF="#config.netnet">Net-to-Net connection</A></LI> -<UL> -<LI><A HREF="#netnet.info.ex">Gather information</A></LI> -<UL> -<LI><A HREF="#16_2_1_1">Get your leftrsasigkey</A></LI> -<LI><A HREF="#16_2_1_2">...and your rightrsasigkey</A></LI> -</UL> -<LI><A HREF="#16_2_2">Edit /etc/ipsec.conf</A></LI> -<LI><A HREF="#16_2_3">Start your connection</A></LI> -<LI><A HREF="#16_2_4">Do not MASQ or NAT packets to be tunneled</A></LI> -<LI><A HREF="#16_2_5">Test your connection</A></LI> -<LI><A HREF="#16_2_6">Finishing touches</A></LI> -</UL> -<LI><A HREF="#config.rw">Road Warrior Configuration</A></LI> -<UL> -<LI><A HREF="#rw.info.ex">Gather information</A></LI> -<UL> -<LI><A HREF="#16_3_1_1">Get your leftrsasigkey...</A></LI> -<LI><A HREF="#16_3_1_2">...and your rightrsasigkey</A></LI> -</UL> -<LI><A HREF="#16_3_2">Customize /etc/ipsec.conf</A></LI> -<LI><A HREF="#16_3_3">Start your connection</A></LI> -<LI><A HREF="#16_3_4">Do not MASQ or NAT packets to be tunneled</A></LI> -<LI><A HREF="#16_3_5">Test your connection</A></LI> -<LI><A HREF="#16_3_6">Finishing touches</A></LI> -<LI><A HREF="#16_3_7">Multiple Road Warriors</A></LI> -</UL> -<LI><A HREF="#16_4">What next?</A></LI> -</UL> -<B><A HREF="#background">Linux FreeS/WAN background</A></B> -<UL> -<LI><A HREF="#dns.background">Some DNS background</A></LI> -<UL> -<LI><A HREF="#forward.reverse">Forward and reverse maps</A></LI> -<LI><A HREF="#17_1_2">Hierarchy and delegation</A></LI> -<LI><A HREF="#17_1_3">Syntax of DNS records</A></LI> -<LI><A HREF="#17_1_4">Cacheing, TTL and propagation delay</A></LI> -</UL> -<LI><A HREF="#MTU.trouble">Problems with packet fragmentation</A></LI> -<LI><A HREF="#nat.background">Network address translation (NAT)</A></LI> -<UL> -<LI><A HREF="#17_3_1">NAT to non-routable addresses</A></LI> -<LI><A HREF="#17_3_2">NAT to routable addresses</A></LI> -</UL> -</UL> -<B><A HREF="#user.examples">FreeS/WAN script examples</A></B> -<UL> -<LI><A HREF="#poltorak">Poltorak's Firewall script</A></LI> -</UL> -<B><A HREF="#makecheck">How to configure to use "make check"</A></B> -<UL> -<LI><A HREF="#19_1">What is "make check"</A></LI> -<LI><A HREF="#19_2">Running "make check"</A></LI> -</UL> -<B><A HREF="#20">How to write a "make check" test</A></B> -<UL> -<LI><A HREF="#20_1">Structure of a test</A></LI> -<LI><A HREF="#20_2">The TESTLIST</A></LI> -<LI><A HREF="#20_3">Test kinds</A></LI> -<LI><A HREF="#20_4">Common parameters</A></LI> -<LI><A HREF="#20_5">KLIPStest paramaters</A></LI> -<LI><A HREF="#20_6">mkinsttest paramaters</A></LI> -<LI><A HREF="#20_7">rpm_build_install_test paramaters</A></LI> -<LI><A HREF="#20_8">libtest paramaters</A></LI> -<LI><A HREF="#20_9">umlplutotest paramaters</A></LI> -<LI><A HREF="#20_10">umlXhost parameters</A></LI> -<LI><A HREF="#20_11">kernel_patch_test paramaters</A></LI> -<LI><A HREF="#20_12">module_compile paramaters</A></LI> -</UL> -<B><A HREF="#21">Current pitfalls</A></B> -<BR> -<BR><B><A HREF="#umltesting">User-Mode-Linux Testing guide</A></B> -<UL> -<LI><A HREF="#22_1">Preliminary Notes on BIND</A></LI> -<LI><A HREF="#22_2">Steps to Install UML for FreeS/WAN</A></LI> -</UL> -<B><A HREF="#23">Debugging the kernel with GDB</A></B> -<UL> -<LI><A HREF="#23_1">Other notes about debugging</A></LI> -</UL> -<B><A HREF="#24">User-Mode-Linux mysteries</A></B> -<BR> -<BR><B><A HREF="#25">Getting more info from uml_netjig</A></B> -<BR> -<BR><B><A HREF="#politics">History and politics of cryptography</A></B> -<UL> -<LI><A HREF="#intro.politics">Introduction</A></LI> -<UL> -<LI><A HREF="#26_1_1">History</A></LI> -<UL> -<LI><A HREF="#26_1_1_1">World War II</A></LI> -<LI><A HREF="#postwar">Postwar and Cold War</A></LI> -<LI><A HREF="#recent">Recent history -- the crypto wars</A></LI> -</UL> -<LI><A HREF="#intro.poli">Politics</A></LI> -<LI><A HREF="#26_1_3">Links</A></LI> -<LI><A HREF="#26_1_4">Outline of this section</A></LI> -</UL> -<LI><A HREF="#leader">From our project leader</A></LI> -<UL> -<LI><A HREF="#gilmore">Swan: Securing the Internet against Wiretapping</A> -</LI> -<UL> -<LI><A HREF="#26_2_1_1">Deployment of IPSEC</A></LI> -<LI><A HREF="#26_2_1_2">Current status</A></LI> -<LI><A HREF="#26_2_1_3">Why?</A></LI> -<LI><A HREF="#26_2_1_4">What You Can Do</A></LI> -<LI><A HREF="#26_2_1_5">Related projects</A></LI> -</UL> -<LI><A HREF="#policestate">Stopping wholesale monitoring</A></LI> -</UL> -<LI><A HREF="#weak">Government promotion of weak crypto</A></LI> -<UL> -<LI><A HREF="#escrow">Escrowed encryption</A></LI> -<LI><A HREF="#shortkeys">Limited key lengths</A></LI> -<UL> -<LI><A HREF="#26_3_2_1">Some real trade-offs</A></LI> -</UL> -</UL> -<LI><A HREF="#exlaw">Cryptography Export Laws</A></LI> -<UL> -<LI><A HREF="#USlaw">US Law</A></LI> -<UL> -<LI><A HREF="#UScontrib">US contributions to FreeS/WAN</A></LI> -</UL> -<LI><A HREF="#wrong">What's wrong with restrictions on cryptography</A></LI> -<LI><A HREF="#Wassenaar">The Wassenaar Arrangement</A></LI> -<LI><A HREF="#status">Export status of Linux FreeS/WAN</A></LI> -<LI><A HREF="#help">Help spread IPsec around</A></LI> -</UL> -<LI><A HREF="#desnotsecure">DES is Not Secure</A></LI> -<UL> -<LI><A HREF="#deshware">Dedicated hardware breaks DES in a few days</A></LI> -<LI><A HREF="#spooks">Spooks may break DES faster yet</A></LI> -<LI><A HREF="#desnet">Networks break DES in a few weeks</A></LI> -<LI><A HREF="#no_des">We disable DES</A></LI> -<LI><A HREF="#40joke">40-bits is laughably weak</A></LI> -<LI><A HREF="#altdes">Triple DES is almost certainly secure</A></LI> -<LI><A HREF="#aes.ipsec">AES in IPsec</A></LI> -</UL> -<LI><A HREF="#press">Press coverage of Linux FreeS/WAN:</A></LI> -<UL> -<LI><A HREF="#26_6_1">FreeS/WAN 1.0 press</A></LI> -<LI><A HREF="#release">Press release for version 1.0</A></LI> -</UL> -</UL> -<B><A HREF="#ipsec.detail">The IPsec protocols</A></B> -<UL> -<LI><A HREF="#27_1">Protocols and phases</A></LI> -<LI><A HREF="#others">Applying IPsec</A></LI> -<UL> -<LI><A HREF="#advantages">Advantages of IPsec</A></LI> -<LI><A HREF="#limitations">Limitations of IPsec</A></LI> -<LI><A HREF="#uses">IPsec is a general mechanism for securing IP</A></LI> -<LI><A HREF="#authonly">Using authentication without encryption</A></LI> -<LI><A HREF="#encnoauth">Encryption without authentication is dangerous</A> -</LI> -<LI><A HREF="#multilayer">Multiple layers of IPsec processing are - possible</A></LI> -<LI><A HREF="#traffic.resist">Resisting traffic analysis</A></LI> -<UL> -<LI><A HREF="#extra">Using "unnecessary" encryption</A></LI> -<LI><A HREF="#multi-encrypt">Using multiple encryption</A></LI> -<LI><A HREF="#fewer">Using fewer tunnels</A></LI> -</UL> -</UL> -<LI><A HREF="#primitives">Cryptographic components</A></LI> -<UL> -<LI><A HREF="#block.cipher">Block ciphers</A></LI> -<LI><A HREF="#hash.ipsec">Hash functions</A></LI> -<UL> -<LI><A HREF="#hmac.ipsec">The HMAC construct</A></LI> -<LI><A HREF="#27_3_2_2">Choice of hash algorithm</A></LI> -</UL> -<LI><A HREF="#DH.keying">Diffie-Hellman key agreement</A></LI> -<LI><A HREF="#RSA.auth">RSA authentication</A></LI> -</UL> -<LI><A HREF="#structure">Structure of IPsec</A></LI> -<UL> -<LI><A HREF="#IKE.ipsec">IKE (Internet Key Exchange)</A></LI> -<UL> -<LI><A HREF="#phases">Phases of IKE</A></LI> -<LI><A HREF="#sequence">Sequence of messages in IKE</A></LI> -<LI><A HREF="#struct.exchange">Structure of IKE messages</A></LI> -</UL> -<LI><A HREF="#services">IPsec Services, AH and ESP</A></LI> -<LI><A HREF="#AH.ipsec">The Authentication Header (AH)</A></LI> -<UL> -<LI><A HREF="#keyed">Keyed MD5 and Keyed SHA</A></LI> -<LI><A HREF="#sequence">Sequence numbers</A></LI> -</UL> -<LI><A HREF="#ESP.ipsec">Encapsulated Security Payload (ESP)</A></LI> -</UL> -<LI><A HREF="#modes">IPsec modes</A></LI> -<UL> -<LI><A HREF="#tunnel.ipsec">Tunnel mode</A></LI> -<LI><A HREF="#transport.ipsec">Transport mode</A></LI> -</UL> -<LI><A HREF="#parts">FreeS/WAN parts</A></LI> -<UL> -<LI><A HREF="#KLIPS.ipsec">KLIPS: Kernel IPsec Support</A></LI> -<LI><A HREF="#Pluto.ipsec">The Pluto daemon</A></LI> -<LI><A HREF="#command">The ipsec(8) command</A></LI> -<LI><A HREF="#ipsec.conf">Linux FreeS/WAN configuration file</A></LI> -</UL> -<LI><A HREF="#key">Key management</A></LI> -<UL> -<LI><A HREF="#current">Currently Implemented Methods</A></LI> -<UL> -<LI><A HREF="#manual">Manual keying</A></LI> -<LI><A HREF="#auto">Automatic keying</A></LI> -</UL> -<LI><A HREF="#notyet">Methods not yet implemented</A></LI> -<UL> -<LI><A HREF="#noauth">Unauthenticated key exchange</A></LI> -<LI><A HREF="#DNS">Key exchange using DNS</A></LI> -<LI><A HREF="#PKI">Key exchange using a PKI</A></LI> -<LI><A HREF="#photuris">Photuris</A></LI> -<LI><A HREF="#skip">SKIP</A></LI> -</UL> -</UL> -</UL> -<B><A HREF="#lists">Mailing lists and newsgroups</A></B> -<UL> -<LI><A HREF="#list.fs">Mailing lists about FreeS/WAN</A></LI> -<UL> -<LI><A HREF="#projlist">The project mailing lists</A></LI> -<UL> -<LI><A HREF="#which.list">Which list should I use?</A></LI> -<LI><A HREF="#policy.list">List policies</A></LI> -</UL> -<LI><A HREF="#archive">Archives of the lists</A></LI> -</UL> -<LI><A HREF="#indexes">Indexes of mailing lists</A></LI> -<LI><A HREF="#otherlists">Lists for related software and topics</A></LI> -<UL> -<LI><A HREF="#28_3_1">Products that include FreeS/WAN</A></LI> -<LI><A HREF="#linux.lists">Linux mailing lists</A></LI> -<LI><A HREF="#ietf">Lists for IETF working groups</A></LI> -<LI><A HREF="#other">Other mailing lists</A></LI> -</UL> -<LI><A HREF="#newsgroups">Usenet newsgroups</A></LI> -</UL> -<B><A HREF="#weblink">Web links</A></B> -<UL> -<LI><A HREF="#freeswan">The Linux FreeS/WAN Project</A></LI> -<UL> -<LI><A HREF="#patch">Add-ons and patches for FreeS/WAN</A></LI> -<UL> -<LI><A HREF="#29_1_1_1">Current patches</A></LI> -<LI><A HREF="#29_1_1_2">Older patches</A></LI> -<LI><A HREF="#VPN.masq">VPN masquerade patches</A></LI> -</UL> -<LI><A HREF="#dist">Distributions including FreeS/WAN</A></LI> -<LI><A HREF="#used">Things FreeS/WAN uses or could use</A></LI> -<LI><A HREF="#alternatives">Other approaches to VPNs for Linux</A></LI> -</UL> -<LI><A HREF="#ipsec.link">The IPsec Protocols</A></LI> -<UL> -<LI><A HREF="#general">General IPsec or VPN information</A></LI> -<LI><A HREF="#overview">IPsec overview documents or slide sets</A></LI> -<LI><A HREF="#otherlang">IPsec information in languages other than - English</A></LI> -<LI><A HREF="#RFCs1">RFCs and other reference documents</A></LI> -<LI><A HREF="#analysis">Analysis and critiques of IPsec protocols</A></LI> -<LI><A HREF="#IP.background">Background information on IP</A></LI> -</UL> -<LI><A HREF="#implement">IPsec Implementations</A></LI> -<UL> -<LI><A HREF="#linuxprod">Linux products</A></LI> -<LI><A HREF="#router">IPsec in router products</A></LI> -<LI><A HREF="#fw.web">IPsec in firewall products</A></LI> -<LI><A HREF="#ipsecos">Operating systems with IPsec support</A></LI> -<LI><A HREF="#29_3_5">IPsec on network cards</A></LI> -<LI><A HREF="#opensource">Open source IPsec implementations</A></LI> -<UL> -<LI><A HREF="#linuxipsec">Other Linux IPsec implementations</A></LI> -<LI><A HREF="#BSD">IPsec for BSD Unix</A></LI> -<LI><A HREF="#misc">IPsec for other systems</A></LI> -</UL> -<LI><A HREF="#interop.web">Interoperability</A></LI> -<UL> -<LI><A HREF="#result">Interoperability results</A></LI> -<LI><A HREF="#test1">Interoperability test sites</A></LI> -</UL> -</UL> -<LI><A HREF="#linux.link">Linux links</A></LI> -<UL> -<LI><A HREF="#linux.basic">Basic and tutorial Linux information</A></LI> -<LI><A HREF="#general">General Linux sites</A></LI> -<LI><A HREF="#docs.ldp">Documentation</A></LI> -<LI><A HREF="#advroute.web">Advanced routing</A></LI> -<LI><A HREF="#linsec">Security for Linux</A></LI> -<LI><A HREF="#firewall.linux">Linux firewalls</A></LI> -<LI><A HREF="#linux.misc">Miscellaneous Linux information</A></LI> -</UL> -<LI><A HREF="#crypto.link">Crypto and security links</A></LI> -<UL> -<LI><A HREF="#security">Crypto and security resources</A></LI> -<UL> -<LI><A HREF="#std.links">The standard link collections</A></LI> -<LI><A HREF="#FAQ">Frequently Asked Question (FAQ) documents</A></LI> -<LI><A HREF="#cryptover">Tutorials</A></LI> -<LI><A HREF="#standards">Crypto and security standards</A></LI> -<LI><A HREF="#quotes">Crypto quotes</A></LI> -</UL> -<LI><A HREF="#policy">Cryptography law and policy</A></LI> -<UL> -<LI><A HREF="#legal">Surveys of crypto law</A></LI> -<LI><A HREF="#oppose">Organisations opposing crypto restrictions</A></LI> -<LI><A HREF="#other.policy">Other information on crypto policy</A></LI> -</UL> -<LI><A HREF="#crypto.tech">Cryptography technical information</A></LI> -<UL> -<LI><A HREF="#cryptolinks">Collections of crypto links</A></LI> -<LI><A HREF="#papers">Lists of online cryptography papers</A></LI> -<LI><A HREF="#interesting">Particularly interesting papers</A></LI> -</UL> -<LI><A HREF="#compsec">Computer and network security</A></LI> -<UL> -<LI><A HREF="#seclink">Security links</A></LI> -<LI><A HREF="#firewall.web">Firewall links</A></LI> -<LI><A HREF="#vpn">VPN links</A></LI> -<LI><A HREF="#tools">Security tools</A></LI> -</UL> -<LI><A HREF="#people">Links to home pages</A></LI> -</UL> -</UL> -<B><A HREF="#ourgloss">Glossary for the Linux FreeS/WAN project</A></B> -<UL> -<LI><A HREF="#jump">Jump to a letter in the glossary</A></LI> -<LI><A HREF="#gloss">Other glossaries</A></LI> -<LI><A HREF="#definitions">Definitions</A></LI> -</UL> -<B><A HREF="#biblio">Bibliography for the Linux FreeS/WAN project</A></B> -<BR> -<BR><B><A HREF="#RFC">IPsec RFCs and related documents</A></B> -<UL> -<LI><A HREF="#RFCfile">The RFCs.tar.gz Distribution File</A></LI> -<LI><A HREF="#sources">Other sources for RFCs & Internet drafts</A></LI> -<UL> -<LI><A HREF="#RFCdown">RFCs</A></LI> -<LI><A HREF="#drafts">Internet Drafts</A></LI> -<LI><A HREF="#FIPS1">FIPS standards</A></LI> -</UL> -<LI><A HREF="#RFCs.tar.gz">What's in the RFCs.tar.gz bundle?</A></LI> -<UL> -<LI><A HREF="#rfc.ov">Overview RFCs</A></LI> -<LI><A HREF="#basic.prot">Basic protocols</A></LI> -<LI><A HREF="#key.ike">Key management</A></LI> -<LI><A HREF="#rfc.detail">Details of various things used</A></LI> -<LI><A HREF="#rfc.ref">Older RFCs which may be referenced</A></LI> -<LI><A HREF="#rfc.dns">RFCs for secure DNS service, which IPsec may use</A> -</LI> -<LI><A HREF="#rfc.exp">RFCs labelled "experimental"</A></LI> -<LI><A HREF="#rfc.rel">Related RFCs</A></LI> -</UL> -</UL> -<B><A HREF="#roadmap">Distribution Roadmap: What's Where in Linux - FreeS/WAN</A></B> -<UL> -<LI><A HREF="#top">Top directory</A></LI> -<LI><A HREF="#doc">Documentation</A></LI> -<LI><A HREF="#klips.roadmap">KLIPS: kernel IP security</A></LI> -<LI><A HREF="#pluto.roadmap">Pluto key and connection management daemon</A> -</LI> -<LI><A HREF="#utils">Utils</A></LI> -<LI><A HREF="#lib">Libraries</A></LI> -<UL> -<LI><A HREF="#fswanlib">FreeS/WAN Library</A></LI> -<LI><A HREF="#otherlib">Imported Libraries</A></LI> -<UL> -<LI><A HREF="#33_6_2_1">LibDES</A></LI> -<LI><A HREF="#33_6_2_2">GMP</A></LI> -</UL> -</UL> -</UL> -<B><A HREF="#umltesting">User-Mode-Linux Testing guide</A></B> -<UL> -<LI><A HREF="#34_1">Preliminary Notes on BIND</A></LI> -<LI><A HREF="#34_2">Steps to Install UML for FreeS/WAN</A></LI> -</UL> -<B><A HREF="#35">Debugging the kernel with GDB</A></B> -<UL> -<LI><A HREF="#35_1">Other notes about debugging</A></LI> -</UL> -<B><A HREF="#36">User-Mode-Linux mysteries</A></B> -<BR> -<BR><B><A HREF="#37">Getting more info from uml_netjig</A></B> -<BR> -<BR><B><A HREF="#makecheck">How to configure to use "make check"</A></B> -<UL> -<LI><A HREF="#38_1">What is "make check"</A></LI> -<LI><A HREF="#38_2">Running "make check"</A></LI> -</UL> -<B><A HREF="#39">How to write a "make check" test</A></B> -<UL> -<LI><A HREF="#39_1">Structure of a test</A></LI> -<LI><A HREF="#39_2">The TESTLIST</A></LI> -<LI><A HREF="#39_3">Test kinds</A></LI> -<LI><A HREF="#39_4">Common parameters</A></LI> -<LI><A HREF="#39_5">KLIPStest paramaters</A></LI> -<LI><A HREF="#39_6">mkinsttest paramaters</A></LI> -<LI><A HREF="#39_7">rpm_build_install_test paramaters</A></LI> -<LI><A HREF="#39_8">libtest paramaters</A></LI> -<LI><A HREF="#39_9">umlplutotest paramaters</A></LI> -<LI><A HREF="#39_10">umlXhost parameters</A></LI> -<LI><A HREF="#39_11">kernel_patch_test paramaters</A></LI> -<LI><A HREF="#39_12">module_compile paramaters</A></LI> -</UL> -<B><A HREF="#40">Current pitfalls</A></B> -<BR> -<BR><B><A HREF="#nightly">Nightly regression testing</A></B> -<BR> -<BR><B><A HREF="#nightlyhowto">How to setup the nightly build</A></B> -<UL> -<LI><A HREF="#42_1"> Files you need to know about</A></LI> -<LI><A HREF="#42_2">Configuring freeswan-regress-env.sh</A></LI> -</UL> -<HR> -<H1><A name="intro">Introduction</A></H1> -<P>This section gives an overview of:</P> -<UL> -<LI>what IP Security (IPsec) does</LI> -<LI>how IPsec works</LI> -<LI>why we are implementing it for Linux</LI> -<LI>how this implementation works</LI> -</UL> -<P>This section is intended to cover only the essentials,<EM> things you - should know before trying to use FreeS/WAN.</EM></P> -<P>For more detailed background information, see the<A href="#politics"> - history and politics</A> and<A href="#ipsec.detail"> IPsec protocols</A> - sections.</P> -<H2><A name="ipsec.intro">IPsec, Security for the Internet Protocol</A></H2> -<P>FreeS/WAN is a Linux implementation of the IPsec (IP security) - protocols. IPsec provides<A href="#encryption"> encryption</A> and<A href="#authentication"> - authentication</A> services at the IP (Internet Protocol) level of the - network protocol stack.</P> -<P>Working at this level, IPsec can protect any traffic carried over IP, - unlike other encryption which generally protects only a particular - higher-level protocol --<A href="#PGP"> PGP</A> for mail,<A href="#ssh"> - SSH</A> for remote login,<A href="#SSL"> SSL</A> for web work, and so - on. This approach has both considerable advantages and some - limitations. For discussion, see our<A href="#others"> IPsec section</A> -</P> -<P>IPsec can be used on any machine which does IP networking. Dedicated - IPsec gateway machines can be installed wherever required to protect - traffic. IPsec can also run on routers, on firewall machines, on - various application servers, and on end-user desktop or laptop - machines.</P> -<P>Three protocols are used</P> -<UL> -<LI><A href="#AH">AH</A> (Authentication Header) provides a packet-level - authentication service</LI> -<LI><A href="#ESP">ESP</A> (Encapsulating Security Payload) provides - encryption plus authentication</LI> -<LI><A href="#IKE">IKE</A> (Internet Key Exchange) negotiates connection - parameters, including keys, for the other two</LI> -</UL> -<P>Our implementation has three main parts:</P> -<UL> -<LI><A href="#KLIPS">KLIPS</A> (kernel IPsec) implements AH, ESP, and - packet handling within the kernel</LI> -<LI><A href="#Pluto">Pluto</A> (an IKE daemon) implements IKE, - negotiating connections with other systems</LI> -<LI>various scripts provide an adminstrator's interface to the machinery</LI> -</UL> -<P>IPsec is optional for the current (version 4) Internet Protocol. - FreeS/WAN adds IPsec to the Linux IPv4 network stack. Implementations - of<A href="#ipv6.gloss"> IP version 6</A> are required to include - IPsec. Work toward integrating FreeS/WAN into the Linux IPv6 stack has<A -href="#ipv6"> started</A>.</P> -<P>For more information on IPsec, see our<A href="#ipsec.detail"> IPsec - protocols</A> section, our collection of<A href="#ipsec.link"> IPsec - links</A> or the<A href="#RFC"> RFCs</A> which are the official - definitions of these protocols.</P> -<H3><A name="intro.interop">Interoperating with other IPsec - implementations</A></H3> -<P>IPsec is designed to let different implementations work together. We - provide:</P> -<UL> -<LI>a<A href="#implement"> list</A> of some other implementations</LI> -<LI>information on<A href="#interop"> using FreeS/WAN with other - implementations</A></LI> -</UL> -<P>The VPN Consortium fosters cooperation among implementers and - interoperability among implementations. Their<A href="http://www.vpnc.org/"> - web site</A> has much more information.</P> -<H3><A name="advantages">Advantages of IPsec</A></H3> -<P>IPsec has a number of security advantages. Here are some - independently written articles which discuss these:</P> -<P><A HREF="http://www.sans.org/rr/"> SANS institute papers</A>. See the - section on Encryption &VPNs. -<BR><A HREF="http://www.cisco.com/en/US/netsol/ns110/ns170/ns171/ns128/networking_solutions_white_papers_list.html"> - Cisco's white papers on "Networking Solutions"</A>. -<BR><A HREF="http://iscs.sourceforge.net/HowWhyBrief/HowWhyBrief.html"> - Advantages of ISCS (Linux Integrated Secure Communications System; - includes FreeS/WAN and other software)</A>.</P> -<H3><A name="applications">Applications of IPsec</A></H3> -<P>Because IPsec operates at the network layer, it is remarkably - flexible and can be used to secure nearly any type of Internet traffic. - Two applications, however, are extremely widespread:</P> -<UL> -<LI>a<A href="#VPN"> Virtual Private Network</A>, or VPN, allows - multiple sites to communicate securely over an insecure Internet by - encrypting all communication between the sites.</LI> -<LI>"Road Warriors" connect to the office from home, or perhaps from a - hotel somewhere</LI> -</UL> -<P>There is enough opportunity in these applications that vendors are - flocking to them. IPsec is being built into routers, into firewall - products, and into major operating systems, primarily to support these - applications. See our<A href="#implement"> list</A> of implementations - for details.</P> -<P>We support both of those applications, and various less common IPsec - applications as well, but we also add one of our own:</P> -<UL> -<LI>opportunistic encryption, the ability to set up FreeS/WAN gateways - so that any two of them can encrypt to each other, and will do so - whenever packets pass between them.</LI> -</UL> -<P>This is an extension we are adding to the protocols. FreeS/WAN is the - first prototype implementation, though we hope other IPsec - implementations will adopt the technique once we demonstrate it. See<A href="#goals"> - project goals</A> below for why we think this is important.</P> -<P>A somewhat more detailed description of each of these applications is - below. Our<A href="#quick_guide"> quickstart</A> section will show you - how to build each of them.</P> -<H4><A name="makeVPN">Using secure tunnels to create a VPN</A></H4> -<P>A VPN, or<STRONG> V</STRONG>irtual<STRONG> P</STRONG>rivate<STRONG> N</STRONG> -etwork lets two networks communicate securely when the only connection - between them is over a third network which they do not trust.</P> -<P>The method is to put a security gateway machine between each of the - communicating networks and the untrusted network. The gateway machines - encrypt packets entering the untrusted net and decrypt packets leaving - it, creating a secure tunnel through it.</P> -<P>If the cryptography is strong, the implementation is careful, and the - administration of the gateways is competent, then one can reasonably - trust the security of the tunnel. The two networks then behave like a - single large private network, some of whose links are encrypted tunnels - through untrusted nets.</P> -<P>Actual VPNs are often more complex. One organisation may have fifty - branch offices, plus some suppliers and clients, with whom it needs to - communicate securely. Another might have 5,000 stores, or 50,000 - point-of-sale devices. The untrusted network need not be the Internet. - All the same issues arise on a corporate or institutional network - whenever two departments want to communicate privately with each other.</P> -<P>Administratively, the nice thing about many VPN setups is that large - parts of them are static. You know the IP addresses of most of the - machines involved. More important, you know they will not change on - you. This simplifies some of the admin work. For cases where the - addresses do change, see the next section.</P> -<H4><A name="road.intro">Road Warriors</A></H4> -<P>The prototypical "Road Warrior" is a traveller connecting to home - base from a laptop machine. Administratively, most of the same problems - arise for a telecommuter connecting from home to the office, especially - if the telecommuter does not have a static IP address.</P> -<P>For purposes of this document:</P> -<UL> -<LI>anyone with a dynamic IP address is a "Road Warrior".</LI> -<LI>any machine doing IPsec processing is a "gateway". Think of the - single-user road warrior machine as a gateway with a degenerate subnet - (one machine, itself) behind it.</LI> -</UL> -<P>These require somewhat different setup than VPN gateways with static - addresses and with client systems behind them, but are basically not - problematic.</P> -<P>There are some difficulties which appear for some road warrior - connections:</P> -<UL> -<LI>Road Wariors who get their addresses via DHCP may have a problem. - FreeS/WAN can quite happily build and use a tunnel to such an address, - but when the DHCP lease expires, FreeS/WAN does not know that. The - tunnel fails, and the only recovery method is to tear it down and - re-build it.</LI> -<LI>If<A href="#NAT.gloss"> Network Address Translation</A> (NAT) is - applied between the two IPsec Gateways, this breaks IPsec. IPsec - authenticates packets on an end-to-end basis, to ensure they are not - altered en route. NAT rewrites packets as they go by. See our<A href="#NAT"> - firewalls</A> document for details.</LI> -</UL> -<P>In most situations, however, FreeS/WAN supports road warrior - connections just fine.</P> -<H4><A name="opp.intro">Opportunistic encryption</A></H4> -<P>One of the reasons we are working on FreeS/WAN is that it gives us - the opportunity to add what we call opportuntistic encryption. This - means that any two FreeS/WAN gateways will be able to encrypt their - traffic, even if the two gateway administrators have had no prior - contact and neither system has any preset information about the other.</P> -<P>Both systems pick up the authentication information they need from - the<A href="#DNS"> DNS</A> (domain name service), the service they - already use to look up IP addresses. Of course the administrators must - put that information in the DNS, and must set up their gateways with - opportunistic encryption enabled. Once that is done, everything is - automatic. The gateways look for opportunities to encrypt, and encrypt - whatever they can. Whether they also accept unencrypted communication - is a policy decision the administrator can make.</P> -<P>This technique can give two large payoffs:</P> -<UL> -<LI>It reduces the administrative overhead for IPsec enormously. You - configure your gateway and thereafter everything is automatic. The need - to configure the system on a per-tunnel basis disappears. Of course, - FreeS/WAN allows specifically configured tunnels to co-exist with - opportunistic encryption, but we hope to make them unnecessary in most - cases.</LI> -<LI>It moves us toward a more secure Internet, allowing users to create - an environment where message privacy is the default. All messages can - be encrypted, provided the other end is willing to co-operate. See our<A -href="#politics"> history and politics of cryptography</A> section for - discussion of why we think this is needed.</LI> -</UL> -<P>Opportunistic encryption is not (yet?) a standard part of the IPsec - protocols, but an extension we are proposing and demonstrating. For - details of our design, see<A href="#applied"> links</A> below.</P> -<P>Only one current product we know of implements a form of - opportunistic encryption.<A href="#ssmail"> Secure sendmail</A> will - automatically encrypt server-to-server mail transfers whenever - possible.</P> -<H3><A name="types">The need to authenticate gateways</A></H3> -<P>A complication, which applies to any type of connection -- VPN, Road - Warrior or opportunistic -- is that a secure connection cannot be - created magically.<EM> There must be some mechanism which enables the - gateways to reliably identify each other.</EM> Without this, they - cannot sensibly trust each other and cannot create a genuinely secure - link.</P> -<P>Any link they do create without some form of<A href="#authentication"> - authentication</A> will be vulnerable to a<A href="#middle"> - man-in-the-middle attack</A>. If<A href="#alicebob"> Alice and Bob</A> - are the people creating the connection, a villian who can re-route or - intercept the packets can pose as Alice while talking to Bob and pose - as Bob while talking to Alice. Alice and Bob then both talk to the man - in the middle, thinking they are talking to each other, and the villain - gets everything sent on the bogus "secure" connection.</P> -<P>There are two ways to build links securely, both of which exclude the - man-in-the middle:</P> -<UL> -<LI>with<STRONG> manual keying</STRONG>, Alice and Bob share a secret - key (which must be transmitted securely, perhaps in a note or via PGP - or SSH) to encrypt their messages. For FreeS/WAN, such keys are stored - in the<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5)</A> file. Of - course, if an enemy gets the key, all is lost.</LI> -<LI>with<STRONG> automatic keying</STRONG>, the two systems authenticate - each other and negotiate their own secret keys. The keys are - automatically changed periodically.</LI> -</UL> -<P>Automatic keying is much more secure, since if an enemy gets one key - only messages between the previous re-keying and the next are exposed. - It is therefore the usual mode of operation for most IPsec deployment, - and the mode we use in our setup examples. FreeS/WAN does support - manual keying for special circumstanes. See this<A href="#prodman"> - section</A>.</P> -<P>For automatic keying, the two systems must authenticate each other - during the negotiations. There is a choice of methods for this:</P> -<UL> -<LI>a<STRONG> shared secret</STRONG> provides authentication. If Alice - and Bob are the only ones who know a secret and Alice recives a message - which could not have been created without that secret, then Alice can - safely believe the message came from Bob.</LI> -<LI>a<A href="#public"> public key</A> can also provide authentication. - If Alice receives a message signed with Bob's private key (which of - course only he should know) and she has a trustworthy copy of his - public key (so that she can verify the signature), then she can safely - believe the message came from Bob.</LI> -</UL> -<P>Public key techniques are much preferable, for reasons discussed<A href="#choose"> - later</A>, and will be used in all our setup examples. FreeS/WAN does - also support auto-keying with shared secret authentication. See this<A href="#prodsecrets"> - section</A>.</P> -<H2><A name="project">The FreeS/WAN project</A></H2> -<P>For complete information on the project, see our web site,<A href="http://liberty.freeswan.org"> - freeswan.org</A>.</P> -<P>In summary, we are implementing the<A href="#IPSEC"> IPsec</A> - protocols for Linux and extending them to do<A href="#carpediem"> - opportunistic encryption</A>.</P> -<H3><A name="goals">Project goals</A></H3> -<P>Our overall goal in FreeS/WAN is to make the Internet more secure and - more private.</P> -<P>Our IPsec implementation supports VPNs and Road Warriors of course. - Those are important applications. Many users will want FreeS/WAN to - build corporate VPNs or to provide secure remote access.</P> -<P>However, our goals in building it go beyond that. We are trying to - help<STRONG> build security into the fabric of the Internet</STRONG> so - that anyone who choses to communicate securely can do so, as easily as - they can do anything else on the net.</P> -<P>More detailed objectives are:</P> -<UL> -<LI>extend IPsec to do<A href="#carpediem"> opportunistic encryption</A> - so that -<UL> -<LI>any two systems can secure their communications without a - pre-arranged connection</LI> -<LI><STRONG>secure connections can be the default</STRONG>, falling back - to unencrypted connections only if: -<UL> -<LI><EM>both</EM> the partner is not set up to co-operate on securing - the connection</LI> -<LI><EM>and</EM> your policy allows insecure connections</LI> -</UL> -</LI> -<LI>a significant fraction of all Internet traffic is encrypted</LI> -<LI>wholesale monitoring of the net (<A href="#intro.poli">examples</A>) - becomes difficult or impossible</LI> -</UL> -</LI> -<LI>help make IPsec widespread by providing an implementation with no - restrictions: -<UL> -<LI>freely available in source code under the<A href="#GPL"> GNU General - Public License</A></LI> -<LI>running on a range of readily available hardware</LI> -<LI>not subject to US or other nations'<A href="#exlaw"> export - restrictions</A>. -<BR> Note that in order to avoid<EM> even the appearance</EM> of being - subject to those laws, the project cannot accept software contributions - --<EM> not even one-line bug fixes</EM> -- from US residents or - citizens.</LI> -</UL> -</LI> -<LI>provide a high-quality IPsec implementation for Linux -<UL> -<LI>portable to all CPUs Linux supports:<A href="#CPUs"> (current list)</A> -</LI> -<LI>interoperable with other IPsec implementations:<A href="#interop"> - (current list)</A></LI> -</UL> -</LI> -</UL> -<P>If we can get opportunistic encryption implemented and widely - deployed, then it becomes impossible for even huge well-funded agencies - to monitor the net.</P> -<P>See also our section on<A href="#politics"> history and politics</A> - of cryptography, which includes our project leader's<A href="#gilmore"> - rationale</A> for starting the project.</P> -<H3><A name="staff">Project team</A></H3> -<P>Two of the team are from the US and can therefore contribute no code:</P> -<UL> -<LI>John Gilmore: founder and policy-maker (<A href="http://www.toad.com/gnu/"> -home page</A>)</LI> -<LI>Hugh Daniel: project manager, Most Demented Tester, and occasionally - Pointy-Haired Boss</LI> -</UL> -<P>The rest of the team are Canadians, working in Canada. (<A href="#status"> -Why Canada?</A>)</P> -<UL> -<LI>Hugh Redelmeier:<A href="#Pluto"> Pluto daemon</A> programmer</LI> -<LI>Richard Guy Briggs:<A href="#KLIPS"> KLIPS</A> programmer</LI> -<LI>Michael Richardson: hacker without portfolio</LI> -<LI>Claudia Schmeing: documentation</LI> -<LI>Sam Sgro: technical support via the<A href="#lists"> mailing lists</A> -</LI> -</UL> -<P>The project is funded by civil libertarians who consider our goals - worthwhile. Most of the team are paid for this work.</P> -<P>People outside this core team have made substantial contributions. - See</P> -<UL> -<LI>our<A href="../CREDITS"> CREDITS</A> file</LI> -<LI>the<A href="#patch"> patches and add-ons</A> section of our web - references file</LI> -<LI>lists below of user-written<A href="#howto"> HowTos</A> and<A href="#applied"> - other papers</A></LI> -</UL> -<P>Additional contributions are welcome. See the<A href="#contrib.faq"> - FAQ</A> for details.</P> -<H2><A name="products">Products containing FreeS/WAN</A></H2> -<P>Unfortunately the<A href="#exlaw"> export laws</A> of some countries - restrict the distribution of strong cryptography. FreeS/WAN is - therefore not in the standard Linux kernel and not in all CD or web - distributions.</P> -<P>FreeS/WAN is, however, quite widely used. Products we know of that - use it are listed below. We would appreciate hearing, via the<A href="#lists"> - mailing lists</A>, of any we don't know of.</P> -<H3><A name="distwith">Full Linux distributions</A></H3> -<P>FreeS/WAN is included in various general-purpose Linux distributions, - mostly from countries (shown in brackets) with more sensible laws:</P> -<UL> -<LI><A href="http://www.suse.com/">SuSE Linux</A> (Germany)</LI> -<LI><A href="http://www.conectiva.com">Conectiva</A> (Brazil)</LI> -<LI><A href="http://www.linux-mandrake.com/en/">Mandrake</A> (France)</LI> -<LI><A href="http://www.debian.org">Debian</A></LI> -<LI>the<A href="http://www.pld.org.pl/"> Polish(ed) Linux Distribution</A> - (Poland)</LI> -<LI><A>Best Linux</A> (Finland)</LI> -</UL> -<P>For distributions which do not include FreeS/WAN and are not Redhat - (which we develop and test on), there is additional information in our<A -href="#otherdist"> compatibility</A> section.</P> -<P>The server edition of<A href="http://www.corel.com"> Corel</A> Linux - (Canada) also had FreeS/WAN, but Corel have dropped that product line.</P> -<H3><A name="kernel_dist">Linux kernel distributions</A></H3> -<UL> -<LI><A href="http://sourceforge.net/projects/wolk/">Working Overloaded - Linux Kernel (WOLK)</A></LI> -</UL> -<H3><A name="office_dist">Office server distributions</A></H3> -<P>FreeS/WAN is also included in several distributions aimed at the - market for turnkey business servers:</P> -<UL> -<LI><A href="http://www.e-smith.com/">e-Smith</A> (Canada), which has - recently been acquired and become the Network Server Solutions group of<A -href="http://www.mitel.com/"> Mitel Networks</A> (Canada)</LI> -<LI><A href="http://www.clarkconnect.org/">ClarkConnect</A> from Point - Clark Networks (Canada)</LI> -<LI><A href="http://www.trustix.net/">Trustix Secure Linux</A> (Norway)</LI> -</UL> -<H3><A name="fw_dist">Firewall distributions</A></H3> -<P>Several distributions intended for firewall and router applications - include FreeS/WAN:</P> -<UL> -<LI>The<A href="http://www.linuxrouter.org/"> Linux Router Project</A> - produces a Linux distribution that will boot from a single floppy. The<A -href="http://leaf.sourceforge.net"> LEAF</A> firewall project provides - several different LRP-based firewall packages. At least one of them, - Charles Steinkuehler's Dachstein, includes FreeS/WAN with X.509 - patches.</LI> -<LI>there are several distributions bootable directly from CD-ROM, - usable on a machine without hard disk. -<UL> -<LI>Dachstein (see above) can be used this way</LI> -<LI><A href="http://www.gibraltar.at/">Gibraltar</A> is based on Debian - GNU/Linux.</LI> -<LI>at time of writing,<A href="www.xiloo.com"> Xiloo</A> is available - only in Chinese. An English version is expected.</LI> -</UL> -</LI> -<LI><A href="http://www.astaro.com/products/index.html">Astaro Security - Linux</A> includes FreeS/WAN. It has some web-based tools for managing - the firewall that include FreeS/WAN configuration management.</LI> -<LI><A href="http://www.linuxwall.de">Linuxwall</A></LI> -<LI><A href="http://www.smoothwall.org/">Smoothwall</A></LI> -<LI><A href="http://www.devil-linux.org/">Devil Linux</A></LI> -<LI>Coyote Linux has a<A href="http://embedded.coyotelinux.com/wolverine/index.php"> - Wolverine</A> firewall/VPN server</LI> -</UL> -<P>There are also several sets of scripts available for managing a - firewall which is also acting as a FreeS/WAN IPsec gateway. See this<A href="#rules.pub"> - list</A>.</P> -<H3><A name="turnkey">Firewall and VPN products</A></H3> -<P>Several vendors use FreeS/WAN as the IPsec component of a turnkey - firewall or VPN product.</P> -<P>Software-only products:</P> -<UL> -<LI><A href="http://www.linuxmagic.com/vpn/index.html">Linux Magic</A> - offer a VPN/Firewall product using FreeS/WAN</LI> -<LI>The Software Group's<A href="http://www.wanware.com/sentinet/"> - Sentinet</A> product uses FreeS/WAN</LI> -<LI><A href="http://www.merilus.com">Merilus</A> use FreeS/WAN in their - Gateway Guardian firewall product</LI> -</UL> -<P>Products that include the hardware:</P> -<UL> -<LI>The<A href="http://www.lasat.com"> LASAT SafePipe[tm]</A> series. is - an IPsec box based on an embedded MIPS running Linux with FreeS/WAN and - a web-config front end. This company also host our freeswan.org web - site.</LI> -<LI>Merilus<A href="http://www.merilus.com/products/fc/index.shtml"> - Firecard</A> is a Linux firewall on a PCI card.</LI> -<LI><A href="http://www.kyzo.com/">Kyzo</A> have a "pizza box" product - line with various types of server, all running from flash. One of them - is an IPsec/PPTP VPN server</LI> -<LI><A href="http://www.pfn.com">PFN</A> use FreeS/WAN in some of their - products</LI> -</UL> -<P><A href="www.rebel.com">Rebel.com</A>, makers of the Netwinder Linux - machines (ARM or Crusoe based), had a product that used FreeS/WAN. The - company is in receivership so the future of the Netwinder is at best - unclear.<A href="#patch"> PKIX patches</A> for FreeS/WAN developed at - Rebel are listed in our web links document.</P> -<H2><A name="docs">Information sources</A></H2> -<H3><A name="docformats">This HowTo, in multiple formats</A></H3> -<P>FreeS/WAN documentation up to version 1.5 was available only in HTML. - Now we ship two formats:</P> -<UL> -<LI>as HTML, one file for each doc section plus a global<A href="toc.html"> - Table of Contents</A></LI> -<LI><A href="HowTo.html">one big HTML file</A> for easy searching</LI> -</UL> -<P>and provide a Makefile to generate other formats if required:</P> -<UL> -<LI><A href="HowTo.pdf">PDF</A></LI> -<LI><A href="HowTo.ps">Postscript</A></LI> -<LI><A href="HowTo.txt">ASCII text</A></LI> -</UL> -<P>The Makefile assumes the htmldoc tool is available. You can download - it from<A href="http://www.easysw.com"> Easy Software</A>.</P> -<P>All formats should be available at the following websites:</P> -<UL> -<LI><A href="http://www.freeswan.org/doc.html">FreeS/WAN project</A></LI> -<LI><A href="http://www.linuxdoc.org">Linux Documentation Project</A></LI> -</UL> -<P>The distribution tarball has only the two HTML formats.</P> -<P><STRONG>Note:</STRONG> If you need the latest doc version, for - example to see if anyone has managed to set up interoperation between - FreeS/WAN and whatever, then you should download the current snapshot. - What is on the web is documentation as of the last release. Snapshots - have all changes I've checked in to date.</P> -<H3><A name="rtfm">RTFM (please Read The Fine Manuals)</A></H3> -<P>As with most things on any Unix-like system, most parts of Linux - FreeS/WAN are documented in online manual pages. We provide a list of<A href="/mnt/floppy/manpages.html"> - FreeS/WAN man pages</A>, with links to HTML versions of them.</P> -<P>The man pages describing configuration files are:</P> -<UL> -<LI><A href="/mnt/floppy/manpage.d/ipsec.conf.5.html">ipsec.conf(5)</A></LI> -<LI><A href="/mnt/floppy/manpage.d/ipsec.secrets.5.html"> -ipsec.secrets(5)</A></LI> -</UL> -<P>Man pages for common commands include:</P> -<UL> -<LI><A href="/mnt/floppy/manpage.d/ipsec.8.html">ipsec(8)</A></LI> -<LI><A href="/mnt/floppy/manpage.d/ipsec_pluto.8.html">ipsec_pluto(8)</A> -</LI> -<LI><A href="/mnt/floppy/manpage.d/ipsec_newhostkey.8.html"> -ipsec_newhostkey(8)</A></LI> -<LI><A href="/mnt/floppy/manpage.d/ipsec_auto.8.html">ipsec_auto(8)</A></LI> -</UL> -<P>You can read these either in HTML using the links above or with the<VAR> - man(1)</VAR> command.</P> -<P>In the event of disagreement between this HTML documentation and the - man pages, the man pages are more likely correct since they are written - by the implementers. Please report any such inconsistency on the<A href="#lists"> - mailing list</A>.</P> -<H3><A name="text">Other documents in the distribution</A></H3> -<P>Text files in the main distribution directory are README, INSTALL, - CREDITS, CHANGES, BUGS and COPYING.</P> -<P>The Libdes encryption library we use has its own documentation. You - can find it in the library directory..</P> -<H3><A name="assumptions">Background material</A></H3> -<P>Throughout this documentation, I write as if the reader had at least - a general familiarity with Linux, with Internet Protocol networking, - and with the basic ideas of system and network security. Of course that - will certainly not be true for all readers, and quite likely not even - for a majority.</P> -<P>However, I must limit amount of detail on these topics in the main - text. For one thing, I don't understand all the details of those topics - myself. Even if I did, trying to explain everything here would produce - extremely long and almost completely unreadable documentation.</P> -<P>If one or more of those areas is unknown territory for you, there are - plenty of other resources you could look at:</P> -<DL> -<DT>Linux</DT> -<DD>the<A href="http://www.linuxdoc.org"> Linux Documentation Project</A> - or a local<A href="http://www.linux.org/groups/"> Linux User Group</A> - and these<A href="#linux.link"> links</A></DD> -<DT>IP networks</DT> -<DD>Rusty Russell's<A href="http://netfilter.samba.org/unreliable-guides/networking-concepts-HOWTO/index.html"> - Networking Concepts HowTo</A> and these<A href="#IP.background"> links</A> -</DD> -<DT>Security</DT> -<DD>Schneier's book<A href="#secrets"> Secrets and Lies</A> and these<A href="#crypto.link"> - links</A></DD> -</DL> -<P>Also, I do make an effort to provide some background material in - these documents. All the basic ideas behind IPsec and FreeS/WAN are - explained here. Explanations that do not fit in the main text, or that - not everyone will need, are often in the<A href="#ourgloss"> glossary</A> -, which is the largest single file in this document set. There is also a<A -href="#background"> background</A> file containing various explanations - too long to fit in glossary definitions. All files are heavily - sprinkled with links to each other and to the glossary.<STRONG> If some - passage makes no sense to you, try the links</STRONG>.</P> -<P>For other reference material, see the<A href="#biblio"> bibliography</A> - and our collection of<A href="web.html#weblinks"> web links</A>.</P> -<P>Of course, no doubt I get this (and other things) wrong sometimes. - Feedback via the<A href="#lists"> mailing lists</A> is welcome.</P> -<H3><A name="archives">Archives of the project mailing list</A></H3> -<P>Until quite recently, there was only one FreeS/WAN mailing list, and - archives of it were:</P> -<UL> -<LI><A href="http://www.sandelman.ottawa.on.ca/linux-ipsec">Canada</A></LI> -<LI><A href="http://www.nexial.com">Holland</A></LI> -</UL> - The two archives use completely different search engines. You might - want to try both. -<P>More recently we have expanded to five lists, each with its own - archive.</P> -<P><A href="#lists">More information</A> on mailing lists.</P> -<H3><A name="howto">User-written HowTo information</A></H3> -<P>Various user-written HowTo documents are available. The ones covering - FreeS/WAN-to-FreeS/WAN connections are:</P> -<UL> -<LI>Jean-Francois Nadeau's<A href="http://jixen.tripod.com/"> practical - configurations</A> document</LI> -<LI>Jens Zerbst's HowTo on<A href="http://dynipsec.tripod.com/"> Using - FreeS/WAN with dynamic IP addresses</A>.</LI> -<LI>an entry in Kurt Seifried's<A href="http://www.securityportal.com/lskb/kben00000013.html"> - Linux Security Knowledge Base</A>.</LI> -<LI>a section of David Ranch's<A href="http://www.ecst.csuchico.edu/~dranch/LINUX/index-linux.html#trinityos"> - Trinity OS Guide</A></LI> -<LI>a section in David Bander's book<A href="#bander"> Linux Security - Toolkit</A></LI> -</UL> -<P>User-wriiten HowTo material may be<STRONG> especially helpful if you - need to interoperate with another IPsec implementation</STRONG>. We - have neither the equipment nor the manpower to test such - configurations. Users seem to be doing an admirable job of filling the - gaps.</P> -<UL> -<LI>list of user-written<A href="interop.html#otherpub"> interoperation - HowTos</A> in our interop document</LI> -</UL> -<P>Check what version of FreeS/WAN user-written documents cover. The - software is under active development and the current version may be - significantly different from what an older document describes.</P> -<H3><A name="applied">Papers on FreeS/WAN</A></H3> -<P>Two design documents show team thinking on new developments:</P> -<UL> -<LI><A href="opportunism.spec">Opportunistic Encryption</A> by technical - lead Henry Spencer and Pluto programmer Hugh Redelemeier</LI> -<LI>discussion of<A href="http://www.sandelman.ottawa.on.ca/SSW/freeswan/klips2req/"> - KLIPS redesign</A></LI> -</UL> -<P>Both documents are works in progress and are frequently revised. For - the latest version, see the<A href="#lists"> design mailing list</A>. - Comments should go to that list.</P> -<P>There is now an<A href="http://www.ietf.org/internet-drafts/draft-richardson-ipsec-opportunistic-06.txt"> - Internet Draft on Opportunistic Encryption</A> by Michael Richardson, - Hugh Redelmeier and Henry Spencer. This is a first step toward getting - the protocol standardised so there can be multiple implementations of - it. Discussion of it takes place on the<A href="http://www.ietf.org/html.charters/ipsec-charter.html"> - IETF IPsec Working Group</A> mailing list.</P> -<P>A number of papers giving further background on FreeS/WAN, or - exploring its future or its applications, are also available:</P> -<UL> -<LI>Both Henry and Richard gave talks on FreeS/WAN at the 2000<A href="http://www.linuxsymposium.org"> - Ottawa Linux Symposium</A>. -<UL> -<LI>Richard's<A href="http://www.conscoop.ottawa.on.ca/rgb/freeswan/ols2k/"> - slides</A></LI> -<LI>Henry's paper</LI> -<LI>MP3 audio of their talks is available from the<A href="http://www.linuxsymposium.org/"> - conference page</A></LI> -</UL> -</LI> -<LI><CITE>Moat: A Virtual Private Network Appliances and Services - Platform</CITE> is a paper about large-scale (a few 100 links) use of - FreeS/WAN in a production application at AT&T Research. It is available - in Postscript or PDF from co-author Steve Bellovin's<A href="http://www.research.att.com/~smb/papers/index.html"> - papers list page</A>.</LI> -<LI>One of the Moat co-authors, John Denker, has also written -<UL> -<LI>a<A href="http://www.av8n.com/vpn/ipsec+routing.htm"> proposal</A> - for how future versions of FreeS/WAN might interact with routing - protocols</LI> -<LI>a<A href="http://www.av8n.com/vpn/wishlist.htm"> wishlist</A> of - possible new features</LI> -</UL> -</LI> -<LI>Bart Trojanowski's web page has a draft design for<A href="http://www.jukie.net/~bart/linux-ipsec/"> - hardware acceleration</A> of FreeS/WAN</LI> -</UL> -<P>Several of these provoked interesting discussions on the mailing - lists, worth searching for in the<A href="#archive"> archives</A>.</P> -<P>There are also several papers in languages other than English, see - our<A href="#otherlang"> web links</A>.</P> -<H3><A name="licensing">License and copyright information</A></H3> -<P>All code and documentation written for this project is distributed - under either the GNU General Public License (<A href="#GPL">GPL</A>) or - the GNU Library General Public License. For details see the COPYING - file in the distribution.</P> -<P>Not all code in the distribution is ours, however. See the CREDITS - file for details. In particular, note that the<A href="#LIBDES"> Libdes</A> - library and the version of<A href="#MD5"> MD5</A> that we use each have - their own license.</P> -<H2><A name="sites">Distribution sites</A></H2> -<P>FreeS/WAN is available from a number of sites.</P> -<H3><A NAME="1_5_1">Primary site</A></H3> -<P>Our primary site, is at xs4all (Thanks, folks!) in Holland:</P> -<UL> -<LI><A href="http://www.xs4all.nl/~freeswan">HTTP</A></LI> -<LI><A href="ftp://ftp.xs4all.nl/pub/crypto/freeswan">FTP</A></LI> -</UL> -<H3><A name="mirrors">Mirrors</A></H3> -<P>There are also mirror sites all over the world:</P> -<UL> -<LI><A href="http://www.flora.org/freeswan">Eastern Canada</A> (limited - resouces)</LI> -<LI><A href="ftp://ludwig.doculink.com/pub/freeswan/">Eastern Canada</A> - (has older versions too)</LI> -<LI><A href="ftp://ntsc.notBSD.org/pub/crypto/freeswan/">Eastern Canada</A> - (has older versions too)</LI> -<LI><A href="ftp://ftp.kame.net/pub/freeswan/">Japan</A></LI> -<LI><A href="ftp://ftp.futuredynamics.com/freecrypto/FreeSWAN/">Hong - Kong</A></LI> -<LI><A href="ftp://ipsec.dk/pub/freeswan/">Denmark</A></LI> -<LI><A href="ftp://ftp.net.lut.ac.uk/freeswan">the UK</A></LI> -<LI><A href="http://storm.alert.sk/comp/mirrors/freeswan/">Slovak - Republic</A></LI> -<LI><A href="http://the.wiretapped.net/security/vpn-tunnelling/freeswan/"> -Australia</A></LI> -<LI><A href="http://freeswan.technolust.cx/">technolust</A></LI> -<LI><A href="http://freeswan.devguide.de/">Germany</A></LI> -<LI>Ivan Moore's<A href="http://snowcrash.tdyc.com/freeswan/"> site</A></LI> -<LI>the<A href="http://www.cryptoarchive.net/"> Crypto Archive</A> on - the<A href="http://www.securityportal.com/"> Security Portal</A> site</LI> -<LI><A href="http://www.wiretapped.net/">Wiretapped.net</A> in Australia</LI> -</UL> -<P>Thanks to those folks as well.</P> -<H3><A name="munitions">The "munitions" archive of Linux crypto software</A> -</H3> -<P>There is also an archive of Linux crypto software called "munitions", - with its own mirrors in a number of countries. It includes FreeS/WAN, - though not always the latest version. Some of its sites are:</P> -<UL> -<LI><A href="http://munitions.vipul.net/">Germany</A></LI> -<LI><A href="http://munitions.iglu.cjb.net/">Italy</A></LI> -<LI><A href="http://munitions2.xs4all.nl/">Netherlands</A></LI> -</UL> -<P>Any of those will have a list of other "munitions" mirrors. There is - also a CD available.</P> -<H2><A NAME="1_6">Links to other sections</A></H2> -<P>For more detailed background information, see:</P> -<UL> -<LI><A href="#politics">history and politics</A> of cryptography</LI> -<LI><A href="#ipsec.detail">IPsec protocols</A></LI> -</UL> -<P>To begin working with FreeS/WAN, go to our<A href="quickstart.html#quick.guide"> - quickstart</A> guide.</P> -<HR> -<A NAME="upgrading"></A> -<H1><A NAME="2">Upgrading to FreeS/WAN 2.x</A></H1> -<H2><A NAME="2_1">New! Built in Opportunistic connections</A></H2> -<P>Out of the box, FreeS/WAN 2.x will attempt to encrypt all your IP - traffic. It will try to establish IPsec connections for:</P> -<UL> -<LI> IP traffic from the Linux box on which you have installed - FreeS/WAN, and</LI> -<LI> outbound IP traffic routed through that Linux box (eg. from a - protected subnet).</LI> -</UL> -<P>FreeS/WAN 2.x uses<STRONG> hidden, automatically enabled<VAR> - ipsec.conf</VAR> connections</STRONG> to do this.</P> -<P>This behaviour is part of our campaign to get Opportunistic - Encryption (OE) widespread in the Linux world, so that any two Linux - boxes can encrypt to one another without prearrangement. There's one - catch, however: you must<A HREF="#quickstart"> set up a few DNS records</A> - to distribute RSA public keys and (if applicable) IPsec gateway - information.</P> -<P>If you start FreeS/WAN before you have set up these DNS records, your - connectivity will be slow, and messages relating to the built in - connections will clutter your logs. If you are unable to set up DNS for - OE, you will wish to<A HREF="#disable_policygroups"> disable the hidden - connections</A>.</P> -<A NAME="upgrading.flagday"></A> -<H3><A NAME="2_1_1">Upgrading Opportunistic Encryption to 2.01 (or - later)</A></H3> -<P>As of FreeS/WAN 2.01, Opportunistic Encryption (OE) uses DNS TXT - resource records (RRs) only (rather than TXT with KEY). This change - causes a "flag day". Users of FreeS/WAN 2.00 (or earlier) OE who are - upgrading may need to post additional resource records.</P> -<P>If you are running<A HREF="#initiate-only"> initiate-only OE</A>, you<EM> - must</EM> put up a TXT record in any forward domain as per our<A HREF="#opp.client"> - quickstart instructions</A>. This replaces your old forward KEY.</P> -<P> If you are running full OE, you require no updates. You already have - the needed TXT record in the reverse domain. However, to facilitate - future features, you may also wish to publish that TXT record in a - forward domain as instructed<A HREF="#opp.incoming"> here</A>.</P> -<P>If you are running OE on a gateway (and encrypting on behalf of - subnetted boxes) you require no updates. You already have the required - TXT record in your gateway's reverse map, and the TXT records for any - subnetted boxes require no updating. However, to facilitate future - features, you may wish to publish your gateway's TXT record in a - forward domain as shown<A HREF="#opp.incoming"> here</A>.</P> -<P> During the transition, you may wish to leave any old KEY records up - for some time. They will provide limited backward compatibility. -<!-- -For more -detail on that compatibility, see <A HREF="oe.known-issues">Known Issues with -OE</A>. ---> -</P> -<H2><A NAME="2_2">New! Policy Groups</A></H2> -<P>We want to make it easy for you to declare security policy as it - applies to IPsec connections.</P> -<P>Policy Groups make it simple to say:</P> -<UL> -<LI>These are the folks I want to talk to in the clear.</LI> -<LI>These spammers' domains -- I don't want to talk to them at all.</LI> -<LI>To talk to the finance department, I must use IPsec.</LI> -<LI>For any other communication, try to encrypt, but it's okay if we - can't.</LI> -</UL> -<P>FreeS/WAN then implements these policies, creating OE connections if - and when needed. You can use Policy Groups along with connections you - explicitly define in ipsec.conf.</P> -<P>For more information, see our<A HREF="policygroups.html"> Policy - Group HOWTO</A>.</P> -<H2><A NAME="2_3">New! Packetdefault Connection</A></H2> -<P>Free/SWAN 2.x ships with the<STRONG> automatically enabled, hidden - connection</STRONG><VAR> packetdefault</VAR>. This configures a - FreeS/WAN box as an OE gateway for any hosts located behind it. As - mentioned above, you must configure some<A HREF="quickstart.html"> DNS - records</A> for OE to work.</P> -<P>As the name implies, this connection functions as a default. If you - have more specific connections, such as policy groups which configure - your FreeS/WAN box as an OE gateway for a local subnet, these will - apply before<VAR> packetdefault</VAR>. You can view<VAR> packetdefault</VAR> -'s specifics in<A HREF="manpage.d/ipsec.conf.5.html"> man ipsec.conf</A> -.</P> -<H2><A NAME="2_4">FreeS/WAN now disables Reverse Path Filtering</A></H2> -<P>FreeS/WAN often doesn't work with reverse path filtering. At start - time, FreeS/WAN now turns rp_filter off, and logs a warning.</P> -<P>FreeS/WAN does not turn it back on again. You can do this yourself - with a command like:</P> -<PRE> echo 1 > /proc/sys/net/ipv4/conf/eth0/rp_filter</PRE> -<P>For eth0, substitute the interface which FreeS/WAN was affecting.</P> -<A NAME="ipsec.conf_v2"></A> -<H2><A NAME="2_5">Revised<VAR> ipsec.conf</VAR></A></H2> -<H3><A NAME="2_5_1">No promise of compatibility</A></H3> -<P>The FreeS/WAN team promised config-file compatibility throughout the - 1.x series. That means a 1.5 config file can be directly imported into - a fresh 1.99 install with no problems.</P> -<P>With FreeS/WAN 2.x, we've given ourselves permission to make the - config file easier to use. The cost: some FreeS/WAN 1.x configurations - will not work properly. Many of the new features are, however, backward - compatible.</P> -<H3><A NAME="2_5_2">Most<VAR> ipsec.conf</VAR> files will work fine</A></H3> -<P>... so long as you paste this line,<STRONG> with no preceding - whitespace</STRONG>, at the top of your config file:</P> -<PRE> version 2</PRE> -<H3><A NAME="2_5_3">Backward compatibility patch</A></H3> -<P>If the new defaults bite you, use<A HREF="ipsec.conf.2_to_1"> this<VAR> - ipsec.conf</VAR> fragment</A> to simulate the old default values.</P> -<H3><A NAME="2_5_4">Details</A></H3> -<P> We've obsoleted various directives which almost no one was using:</P> -<PRE> dump - plutobackgroundload - no_eroute_pass - lifetime - rekeystart - rekeytries</PRE> -<P>For most of these, there is some other way to elicit the desired - behaviour. See<A HREF="http://lists.freeswan.org/pipermail/design/2002-August/003243.html"> - this post</A>.</P> -<P> We've made some settings, which almost everyone was using, defaults. - For example:</P> -<PRE> interfaces=%defaultroute - plutoload=%search - plutostart=%search - uniqueids=yes</PRE> -<P>We've also changed some default values to help with OE and Policy - Groups:</P> -<PRE> authby=rsasig ## not secret!!! - leftrsasigkey=%dnsondemand ## looks up missing keys in DNS when needed. - rightrsasigkey=%dnsondemand</PRE> -<P> Of course, you can still override any defaults by explictly - declaring something else in your connection.</P> -<P><A HREF="http://lists.freeswan.org/pipermail/design/2002-August/003243.html"> - A post with a list of many ipsec.conf changes.</A> -<BR><A HREF="manpage.d/ipsec.conf.5.html"> Current ipsec.conf manual.</A> -</P> -<A NAME="upgrading.rpms"></A> -<H3><A NAME="2_5_5">Upgrading from 1.x RPMs to 2.x RPMs</A></H3> -<P>Note: When upgrading from 1-series to 2-series RPMs,<VAR> rpm -U</VAR> - will not work.</P> -<P>You must instead erase the 1.x RPMs, then install the 2.x set:</P> -<PRE> rpm -e freeswan</PRE> -<PRE> rpm -e freeswan-module</PRE> -<P>On erasing, your old<VAR> ipsec.conf</VAR> should be moved to<VAR> - ipsec.conf.rpmsave</VAR>. Keep this. You will probably want to copy - your existing connections to the end of your new 2.x file.</P> -<P>Install the RPMs suitable for your kernel version, such as:</P> -<PRE> rpm -ivh freeswan-module-2.04_2.4.20_20.9-0.i386.rpm</PRE> -<PRE> rpm -ivh freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm</PRE> -<P>Or, to splice the files:</P> -<PRE> cat /etc/ipsec.conf /etc/ipsec.conf.rpmsave > /etc/ipsec.conf.tmp - mv /etc/ipsec.conf.tmp /etc/ipsec.conf</PRE> -<P>Then, remove the redundant<VAR> conn %default</VAR> and<VAR> config - setup</VAR> sections. Unless you have done any special configuring - here, you'll likely want to remove the 1.x versions. Remove<VAR> conn - OEself</VAR>, if present.</P> -<HR> -<H1><A name="quickstart">Quickstart Guide to Opportunistic Encryption</A> -</H1> -<A name="quick_guide"></A> -<H2><A name="opp.setup">Purpose</A></H2> -<P>This page will get you started using Linux FreeS/WAN with - opportunistic encryption (OE). OE enables you to set up IPsec tunnels - without co-ordinating with another site administrator, and without hand - configuring each tunnel. If enough sites support OE, a "FAX effect" - occurs, and many of us can communicate without eavesdroppers.</P> -<H3><A NAME="3_1_1">OE "flag day"</A></H3> -<P>As of FreeS/WAN 2.01, OE uses DNS TXT resource records (RRs) only - (rather than TXT with KEY). This change causes a<A href="http://jargon.watson-net.com/jargon.asp?w=flag+day"> - "flag day"</A>. Users of FreeS/WAN 2.00 (or earlier) OE who are - upgrading may require additional resource records, as detailed in our<A href="#upgrading.flagday"> - upgrading document</A>. OE setup instructions here are for 2.02 or - later.</P> -<H2><A name="opp.dns">Requirements</A></H2> -<P>To set up opportunistic encryption, you will need:</P> -<UL> -<LI>a Linux box. For OE to the public Internet, this box must NOT be - behind<A HREF="#NAT.gloss"> Network Address Translation</A> (NAT).</LI> -<LI>to install Linux FreeS/WAN 2.02 or later</LI> -<LI>either control over your reverse DNS (for full opportunism) or the - ability to write to some forward domain (for initiator-only).<A HREF="http://www.fdns.net"> - This free DNS service</A> explicitly supports forward TXT records for - FreeS/WAN use.</LI> -<LI>(for full opportunism) a static IP</LI> -</UL> -<P>Note: Currently, only Linux FreeS/WAN supports opportunistic - encryption.</P> -<H2><A name="easy.install">RPM install</A></H2> -<P>Our instructions are for a recent Red Hat with a 2.4-series stock or - Red Hat updated kernel. For other ways to install, see our<A href="#install"> - install document</A>.</P> -<H3><A NAME="3_3_1">Download RPMs</A></H3> -<P>If we have prebuilt RPMs for your Red Hat system, this command will - get them:</P> -<PRE> ncftpget ftp://ftp.xs4all.nl/pub/crypto/freeswan/binaries/RedHat-RPMs/`uname -r | tr -d 'a-wy-z'`/\*</PRE> -<P>If that fails, you will need to try<A HREF="install.html"> another - install method</A>. Our kernel modules<B> will only work on the Red Hat - kernel they were built for</B>, since they are very sensitive to small - changes in the kernel.</P> -<P>If it succeeds, you will have userland tools, a kernel module, and an - RPM signing key:</P> -<PRE> freeswan-module-2.04_2.4.20_20.9-0.i386.rpm - freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm - freeswan-rpmsign.asc</PRE> -<H3><A NAME="3_3_2">Check signatures</A></H3> -<P>If you're running RedHat 8.x or later, import the RPM signing key - into the RPM database:</P> -<PRE> rpm --import freeswan-rpmsign.asc</PRE> -<P>For RedHat 7.x systems, you'll need to add it to your<A HREF="#PGP"> - PGP</A> keyring:</P> -<PRE> pgp -ka freeswan-rpmsign.asc</PRE> -<P>Check the digital signatures on both RPMs using:</P> -<PRE> rpm --checksig freeswan*.rpm </PRE> -<P>You should see that these signatures are good:</P> -<PRE> freeswan-module-2.04_2.4.20_20.9-0.i386.rpm: pgp md5 OK - freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm: pgp md5 OK</PRE> -<H3><A NAME="3_3_3">Install the RPMs</A></H3> -<P>Become root:</P> -<PRE> su</PRE> -<P>Install your RPMs with:</P> -<P></P> -<PRE> rpm -ivh freeswan*.rpm</PRE> -<P>If you're upgrading from FreeS/WAN 1.x RPMs, and have problems with - that command, see<A HREF="#upgrading.rpms"> this note</A>.</P> -<P>Then, start FreeS/WAN:</P> -<PRE> service ipsec start</PRE> -<H3><A name="testinstall">Test</A></H3> -<P>To check that you have a successful install, run:</P> -<PRE> ipsec verify</PRE> -<P>You should see as part of the<VAR> verify</VAR> output:</P> -<PRE> - Checking your system to see if IPsec got installed and started correctly - Version check and ipsec on-path [OK] - Checking for KLIPS support in kernel [OK] - Checking for RSA private key (/etc/ipsec.secrets) [OK] - Checking that pluto is running [OK] - ...</PRE> -<P>If any of these first four checks fails, see our<A href="#install.check"> - troubleshooting guide</A>.</P> -<H2><A name="opp.setups.list">Our Opportunistic Setups</A></H2> -<H3><A NAME="3_4_1">Full or partial opportunism?</A></H3> -<P>Determine the best form of opportunism your system can support.</P> -<UL> -<LI>For<A HREF="#opp.incoming"> full opportunism</A>, you'll need a - static IP and and either control over your reverse DNS or an ISP that - can add the required TXT record for you.</LI> -<LI>If you have a dynamic IP, and/or write access to forward DNS only, - you can do<A HREF="#opp.client"> initiate-only opportunism</A></LI> -<LI>To protect traffic bound for real IPs behind your gateway, use<A HREF="#opp.gate"> - this form of full opportunism</A>.</LI> -</UL> -<H2><A name="opp.client">Initiate-only setup</A></H2> -<H3><A NAME="3_5_1">Restrictions</A></H3> -<P>When you set up initiate-only Opportunistic Encryption (iOE):</P> -<UL> -<LI>there will be<STRONG> no incoming connection requests</STRONG>; you - can initiate all the IPsec connections you need.</LI> -<LI><STRONG>only one machine is visible</STRONG> on your end of the - connection.</LI> -<LI>iOE also protects traffic on behalf of<A HREF="#NAT.gloss"> NATted</A> - hosts behind the iOE box.</LI> -</UL> -<P>You cannot network a group of initiator-only machines if none of - these is capable of responding to OE. If one is capable of responding, - you may be able to create a hub topology using routing.</P> -<H3><A name="forward.dns">Create and publish a forward DNS record</A></H3> -<H4><A NAME="3_5_2_1">Find a domain you can use</A></H4> -<P>Find a DNS forward domain (e.g. example.com) where you can publish - your key. You'll need access to the DNS zone files for that domain. - This is common for a domain you own. Some free DNS providers, such as<A HREF="http://www.fdns.net"> - this one</A>, also provide this service.</P> -<P>Dynamic IP users take note: the domain where you place your key need - not be associated with the IP address for your system, or even with - your system's usual hostname.</P> -<H4><A NAME="3_5_2_2">Choose your ID</A></H4> -<P>Choose a name within that domain which you will use to identify your - machine. It's convenient if this can be the same as your hostname:</P> -<PRE> [root@xy root]# hostname --fqdn - xy.example.com</PRE> -<P>This name in FQDN (fully-qualified domain name) format will be your - ID, for DNS key lookup and IPsec negotiation.</P> -<H4><A NAME="3_5_2_3">Create a forward TXT record</A></H4> -<P>Generate a forward TXT record containing your system's public key - with a command like:</P> -<PRE> ipsec showhostkey --txt @xy.example.com</PRE> -<P>using your chosen ID in place of xy.example.com. This command takes - the contents of /etc/ipsec.secrets and reformats it into something - usable by ISC's BIND. The result should look like this (with the key - data trimmed down for clarity):</P> -<PRE> - ; RSA 2192 bits xy.example.com Thu Jan 2 12:41:44 2003 - IN TXT "X-IPsec-Server(10)=@xy.example.com" - "AQOF8tZ2... ...+buFuFn/" -</PRE> -<H4><A NAME="3_5_2_4">Publish the forward TXT record</A></H4> -<P>Insert the record into DNS, or have a system adminstrator do it for - you. It may take up to 48 hours for the record to propagate, but it's - usually much quicker.</P> -<H3><A NAME="3_5_3">Test that your key has been published</A></H3> -<P>Check your DNS work</P> -<PRE> ipsec verify --host xy.example.com</PRE> -<P>As part of the<VAR> verify</VAR> output, you ought to see something - like:</P> -<PRE> ... - Looking for TXT in forward map: xy.example.com [OK] - ...</PRE> -<P>For this type of opportunism, only the forward test is relevant; you - can ignore the tests designed to find reverse records.</P> -<H3><A NAME="3_5_4">Configure, if necessary</A></H3> -<P> If your ID is the same as your hostname, you're ready to go. - FreeS/WAN will use its<A HREF="policygroups.html"> built-in connections</A> - to create your iOE functionality.</P> -<P>If you have chosen a different ID, you must tell FreeS/WAN about it - via<A HREF="manpage.d/ipsec.conf.5.html"><VAR> ipsec.conf</VAR></A>:</P> -<PRE> config setup - myid=@myname.freedns.example.com</PRE> -<P>and restart FreeS/WAN:</P> -<PRE> service ipsec restart</PRE> -<P>The new ID will be applied to the built-in connections.</P> -<P>Note: you can create more complex iOE configurations as explained in - our<A HREF="#policygroups"> policy groups document</A>, or disable OE - using<A HREF="#disable_policygroups"> these instructions</A>.</P> -<H3><A NAME="3_5_5">Test</A></H3> -<P>That's it!<A HREF="#opp.test"> Test your connections</A>.</P> -<A name="opp.incoming"></A> -<H2><A NAME="3_6">Full Opportunism</A></H2> -<P>Full opportunism allows you to initiate and receive opportunistic - connections on your machine.</P> -<A name="incoming.opp.dns"></A> -<H3><A NAME="3_6_1">Put a TXT record in a Forward Domain</A></H3> -<P>To set up full opportunism, first<A HREF="#forward.dns"> set up a - forward TXT record</A> as for<A HREF="#opp.client"> initiator-only OE</A> -, using an ID (for example, your hostname) that resolves to your IP. Do - not configure<VAR> /etc/ipsec.conf</VAR>, but continue with the - instructions for full opportunism, below.</P> -<P>Note that this forward record is not currently necessary for full OE, - but will facilitate future features.</P> -<A name="incoming.opp.dns"></A> -<H3><A NAME="3_6_2">Put a TXT record in Reverse DNS</A></H3> -<P>You must be able to publish your DNS RR directly in the reverse - domain. FreeS/WAN will not follow a PTR which appears in the reverse, - since a second lookup at connection start time is too costly.</P> -<H4><A NAME="3_6_2_1">Create a Reverse DNS TXT record</A></H4> -<P>This record serves to publicize your FreeS/WAN public key. In - addition, it lets others know that this machine can receive - opportunistic connections, and asserts that the machine is authorized - to encrypt on its own behalf.</P> -<P>Use the command:</P> -<PRE> ipsec showhostkey --txt 192.0.2.11</PRE> -<P>where you replace 192.0.2.11 with your public IP.</P> -<P>The record (with key shortened) looks like:</P> -<PRE> ; RSA 2048 bits xy.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/"</PRE> -<H4><A NAME="3_6_2_2">Publish your TXT record</A></H4> -<P>Send these records to your ISP, to be published in your IP's reverse - map. It may take up to 48 hours for these to propagate, but usually - takes much less time.</P> -<H3><A NAME="3_6_3">Test your DNS record</A></H3> -<P>Check your DNS work with</P> -<PRE> ipsec verify --host xy.example.com</PRE> -<P>As part of the<VAR> verify</VAR> output, you ought to see something - like:</P> -<PRE> ... - Looking for TXT in reverse map: 11.2.0.192.in-addr.arpa [OK] - ...</PRE> -<P>which indicates that you've passed the reverse-map test.</P> -<H3><A NAME="3_6_4">No Configuration Needed</A></H3> -<P>FreeS/WAN 2.x ships with full OE enabled, so you don't need to - configure anything. To enable OE out of the box, FreeS/WAN 2.x uses the - policy group<VAR> private-or-clear</VAR>, which creates IPsec - connections if possible (using OE if needed), and allows traffic in the - clear otherwise. You can create more complex OE configurations as - described in our<A HREF="#policygroups"> policy groups document</A>, or - disable OE using<A HREF="#disable_policygroups"> these instructions</A> -.</P> -<P>If you've previously configured for initiator-only opportunism, - remove<VAR> myid=</VAR> from<VAR> config setup</VAR>, so that peer - FreeS/WANs will look up your key by IP. Restart FreeS/WAN so that your - change will take effect, with</P> -<PRE> service ipsec restart</PRE> -<H3><A NAME="3_6_5">Consider Firewalling</A></H3> -<P>If you are running a default install of RedHat 8.x, take note: you - will need to alter your iptables rule setup to allow IPSec traffic - through your firewall. See<A HREF="#simple.rules"> our firewall - document</A> for sample<VAR> iptables</VAR> rules.</P> -<H3><A NAME="3_6_6">Test</A></H3> -<P>That's it. Now,<A HREF="#opp.test"> test your connection</A>.</P> -<H3><A NAME="3_6_7">Test</A></H3> -<P>Instructions are in the next section.</P> -<H2><A NAME="opp.test">Testing opportunistic connections</A></H2> -<P>Be sure IPsec is running. You can see whether it is with:</P> -<PRE> ipsec setup status</PRE> -<P>If need be, you can restart it with:</P> -<PRE> service ipsec restart</PRE> -<P>Load a FreeS/WAN test website from the host on which you're running - FreeS/WAN. Note: the feds may be watching these sites. Type one of:</P> -<P></P> -<PRE> links oetest.freeswan.org</PRE> -<PRE> links oetest.freeswan.nl</PRE> - -<!--<PRE> links oetest.freeswan.ca</PRE>--> -<P>A positive result looks like this:</P> -<PRE> - You seem to be connecting from: 192.0.2.11 which DNS says is: - gateway.example.com - _________________________________________________________________ - - Status E-route - OE enabled 16 192.139.46.73/32 -> 192.0.2.11/32 => - tun0x2097@192.0.2.11 - OE enabled 176 192.139.46.77/32 -> 192.0.2.11/32 => - tun0x208a@192.0.2.11 -</PRE> -<P>If you see this, congratulations! Your OE host or gateway will now - encrypt its own traffic whenever it can. For more OE tests, please see - our<A HREF="#test.oe"> testing document</A>. If you have difficulty, - see our<A HREF="#oe.trouble"> OE troubleshooting tips</A>.</P> -<H2><A NAME="3_8">Now what?</A></H2> -<P>Please see our<A HREF="policygroups.html"> policy groups document</A> - for more ways to set up Opportunistic Encryption.</P> -<P>You may also wish to make some<A HREF="config.html"> pre-configured - connections</A>.</P> -<H2><A NAME="3_9">Notes</A></H2> -<UL> -<LI>We assume some facts about your system in order to make - Opportunistic Encryption easier to configure. For example, we assume - that you wish to have FreeS/WAN secure your default interface.</LI> -<LI>You may change this, and other settings, by altering the<VAR> config - setup</VAR> section in<VAR> /etc/ipsec.conf</VAR>.</LI> -<LI>Note that the built-in connections used to build policy groups do - not inherit from<VAR> conn default</VAR>.</LI> - -<!-- -<LI>If you do not define your local identity -(eg. <VAR>leftid</VAR>), this will be the IP address of your default -FreeS/WAN interface. ---> -<LI> If you fail to define your local identity and do not fill in your - reverse DNS entry, you will not be able to use OE.</LI> -</UL> -<A NAME="oe.trouble"></A> -<H2><A NAME="3_10">Troubleshooting OE</A></H2> -<P>See the OE troubleshooting hints in our<A HREF="#oe.trouble"> - troubleshooting guide</A>.</P> -<A NAME="oe.known-issues"></A> -<H2><A NAME="3_11">Known Issues</A></H2> -<P>Please see<A HREF="opportunism.known-issues"> this list</A> of known - issues with Opportunistic Encryption.</P> -<HR> -<H1><A NAME="4">How to Configure Linux FreeS/WAN with Policy Groups</A></H1> -<A NAME="policygroups"></A> -<H2><A NAME="4_1">What are Policy Groups?</A></H2> -<P><STRONG>Policy Groups</STRONG> are an elegant general mechanism to - configure FreeS/WAN. They are useful for many FreeS/WAN users.</P> -<P>In previous FreeS/WAN versions, you needed to configure each IPsec - connection explicitly, on both local and remote hosts. This could - become complex.</P> -<P>By contrast, Policy Groups allow you to set local IPsec policy for - lists of remote hosts and networks, simply by listing the hosts and - networks which you wish to have special treatment in one of several - Policy Group files. FreeS/WAN then internally creates the connections - needed to implement each policy.</P> -<P>In the next section we describe our five Base Policy Groups, which - you can use to configure IPsec in many useful ways. Later, we will show - you how to create an IPsec VPN using one line of configuration for each - remote host or network.</P> -<A NAME="builtin_policygroups"></A> -<H3><A NAME="4_1_1">Built-In Security Options</A></H3> -<P>FreeS/WAN offers these Base Policy Groups:</P> -<DL> -<DT>private</DT> -<DD> FreeS/WAN only communicates privately with the listed<A HREF="#CIDR"> - CIDR</A> blocks. If needed, FreeS/WAN attempts to create a connection - opportunistically. If this fails, FreeS/WAN blocks communication. - Inbound blocking is assumed to be done by the firewall. FreeS/WAN - offers firewall hooks but no modern firewall rules to help with inbound - blocking.</DD> -<DT>private-or-clear</DT> -<DD> FreeS/WAN prefers private communication with the listed CIDR - blocks. If needed, FreeS/WAN attempts to create a connection - opportunistically. If this fails, FreeS/WAN allows traffic in the - clear.</DD> -<DT>clear-or-private</DT> -<DD> FreeS/WAN communicates cleartext with the listed CIDR blocks, but - also accepts inbound OE connection requests from them. Also known as<A HREF="#passive.OE"> - passive OE (pOE)</A>, this policy may be used to create an<A HREF="#responder"> - opportunistic responder</A>.</DD> -<DT>clear</DT> -<DD> FreeS/WAN only communicates cleartext with the listed CIDR blocks.</DD> -<DT>block</DT> -<DD>FreeS/WAN blocks traffic to and from and the listed CIDR blocks. - Inbound blocking is assumed to be done by the firewall. FreeS/WAN - offers firewall hooks but no modern firewall rules to help with inbound - blocking. -<!-- also called "blockdrop".--> -</DD> -</DL> -<A NAME="policy.group.notes"></A> -<P>Notes:</P> -<UL> -<LI>Base Policy Groups apply to communication with this host only.</LI> -<LI>The most specific rule (whether policy or pre-configured connection) - applies. This has several practical applications: -<UL> -<LI>If CIDR blocks overlap, FreeS/WAN chooses the most specific - applicable block.</LI> -<LI>This decision also takes into account any pre-configured connections - you may have.</LI> -<LI>If the most specific connection is a pre-configured connection, the - following procedure applies. If that connection is up, it will be used. - If it is routed, it will be brought up. If it is added, no action will - be taken.</LI> -</UL> -</LI> -<LI>Base Policy Groups are created using built-in connections. Details - in<A HREF="manpage.d/ipsec.conf.5.html"> man ipsec.conf</A>.</LI> -<LI>All Policy Groups are bidirectional.<A HREF="src/policy-groups-table.html"> - This chart</A> shows some technical details. FreeS/WAN does not support - one-way encryption, since it can give users a false sense of security.</LI> -</UL> -<H2><A NAME="4_2">Using Policy Groups</A></H2> -<P>The Base Policy Groups which build IPsec connections rely on - Opportunistic Encryption. To use the following examples, you must first - become OE-capable, as described in our<A HREF="#quickstart"> quickstart - guide</A>.<A NAME="example1"></A></P> -<H3><A NAME="4_2_1">Example 1: Using a Base Policy Group</A></H3> -<P>Simply place CIDR blocks (<A HREF="#dnswarning">names</A>, IPs or IP - ranges) in /etc/ipsec.d/policies/<VAR>[groupname]</VAR>, and reread the - policy group files.</P> -<P>For example, the<VAR> private-or-clear</VAR> policy tells FreeS/WAN - to prefer encrypted communication to the listed CIDR blocks. Failing - that, it allows talk in the clear.</P> -<P>To make this your default policy, place<A HREF="#fullnet"> fullnet</A> - in the<VAR> private-or-clear</VAR> policy group file:</P> -<PRE> [root@xy root]# cat /etc/ipsec.d/policies/private-or-clear - # This file defines the set of CIDRs (network/mask-length) to which - # communication should be private, if possible, but in the clear otherwise. - .... - 0.0.0.0/0</PRE> -<P>and reload your policies with</P> -<PRE> ipsec auto --rereadgroups</PRE> -<P>Use<A HREF="#opp.test"> this test</A> to verify opportunistic - connections.</P> -<A NAME="example2"></A> -<H3><A NAME="4_2_2">Example 2: Defining IPsec Security Policy with - Groups</A></H3> -<P>Defining IPsec security policy with Base Policy Groups is like - creating a shopping list: just put CIDR blocks in the appropriate group - files. For example:</P> -<PRE> [root@xy root]# cd /etc/ipsec.d/policies - [root@xy policies]# cat private - 192.0.2.96/27 # The finance department - 192.0.2.192/29 # HR - 192.0.2.12 # HR gateway - irc.private.example.com # Private IRC server - - [root@xy policies]# cat private-or-clear - 0.0.0.0/0 # My default policy: try to encrypt. - - [root@xy policies]# cat clear - 192.0.2.18/32 # My POP3 server - 192.0.2.19/32 # My Web proxy - - [root@xy policies]# cat block - spamsource.example.com</PRE> -<P>To make these settings take effect, type:</P> -<PRE> ipsec auto --rereadgroups</PRE> -<P>Notes:</P> -<UL> -<LI>For opportunistic connection attempts to succeed, all participating - FreeS/WAN hosts and gateways must be configured for OE.</LI> -<LI>Examples 3 through 5 show how to implement a detailed<VAR> private</VAR> - policy.</LI> -<LI><A NAME="dnswarning"></A><FONT COLOR="RED"> Warning:</FONT> Using - DNS names in policy files and ipsec.conf can be tricky. If the name - does not resolve, the policy will not be implemented for that name. It - is therefore safer either to use IPs, or to put any critical names in - /etc/hosts. We plan to implement periodic DNS retry to help with this. -<BR> Names are resolved at FreeS/WAN startup, or when the policies are - reloaded. Unfortunately, name lookup can hold up the startup process. - If you have fast DNS servers, the problem may be less severe.</LI> -</UL> -<A HREF="example3"></A> -<H3><A NAME="4_2_3">Example 3: Creating a Simple IPsec VPN with the<VAR> - private</VAR> Group</A></H3> -<P>You can create an IPsec VPN between several hosts, with only one line - of configuration per host, using the<VAR> private</VAR> policy group.</P> -<P>First, use our<A HREF="quickstart.html"> quickstart guide</A> to set - up each participating host with a FreeS/WAN install and OE.</P> -<P>In one host's<VAR> /etc/ipsec.d/policies/private</VAR>, list the - peers to which you wish to protect traffic. For example:</P> -<PRE> [root@xy root]# cd /etc/ipsec.d/policies - [root@xy policies]# cat private - 192.0.2.9 # several hosts at example.com - 192.0.2.11 - 192.0.2.12 - irc.private.example.com -</PRE> -<P>Copy the<VAR> private</VAR> file to each host. Remove the local host, - and add the initial host.</P> -<PRE> scp2 /etc/ipsec.d/policies/private root@192.0.2.12:/etc/ipsec.d/policies/private</PRE> -<P>On each host, reread the policy groups with</P> -<PRE> ipsec auto --rereadgroups</PRE> -<P>That's it! You're configured.</P> -<P>Test by pinging between two hosts. After a second or two, traffic - should flow, and</P> -<PRE> ipsec eroute</PRE> -<P>should yield something like</P> -<PRE> 192.0.2.11/32 -> 192.0.2.8/32 => tun0x149f@192.0.2.8</PRE> -<P>where your host IPs are substituted for 192.0.2.11 and 192.0.2.8.</P> -<P>If traffic does not flow, there may be an error in your OE setup. - Revisit our<A HREF="quickstart.html"> quickstart guide</A>.</P> -<P>Our next two examples show you how to add subnets to this IPsec VPN.</P> -<A NAME="example4"></A> -<H3><A NAME="4_2_4">Example 4: New Policy Groups to Protect a Subnet</A></H3> -<P>To protect traffic to a subnet behind your FreeS/WAN gateway, you'll - need additional DNS records, and new policy groups. To set up the DNS, - see our<A HREF="#opp.gate"> quickstart guide</A>. To create five new - policy groups for your subnet, copy these connections to<VAR> - /etc/ipsec.conf</VAR>. Substitute your subnet's IPs for 192.0.2.128/29.</P> -<PRE> -conn private-net - also=private # inherits settings (eg. auto=start) from built in conn - leftsubnet=192.0.2.128/29 # your subnet's IPs here - -conn private-or-clear-net - also=private-or-clear - leftsubnet=192.0.2.128/29 - -conn clear-or-private-net - also=clear-or-private - leftsubnet=192.0.2.128/29 - -conn clear-net - also=clear - leftsubnet=192.0.2.128/29 - -conn block-net - also=block - leftsubnet=192.0.2.128/29 -</PRE> -<P>Copy the gateway's files to serve as the initial policy group files - for the new groups:</P> -<PRE> - cp -p /etc/ipsec.d/policies/private /etc/ipsec.d/policies/private-net - cp -p /etc/ipsec.d/policies/private-or-clear /etc/ipsec.d/policies/private-or-clear-net - cp -p /etc/ipsec.d/policies/clear-or-private /etc/ipsec.d/policies/clear-or-private-net - cp -p /etc/ipsec.d/policies/clear /etc/ipsec.d/policies/clear-net - cp -p /etc/ipsec.d/policies/block /etc/ipsec.d/policies/block -</PRE> -<P><STRONG>Tip: Since a missing policy group file is equivalent to a - file with no entries, you need only create files for the connections - you'll use.</STRONG></P> -<P>To test one of your new groups, place the fullnet 0.0.0.0/0 in<VAR> - private-or-clear-net</VAR>. Perform the subnet test in<A HREF="#opp.test"> - our quickstart guide</A>. You should see a connection, and</P> -<PRE> ipsec eroute</PRE> -<P>should include an entry which mentions the subnet node's IP and the - OE test site IP, like this:</P> -<PRE> 192.0.2.131/32 -> 192.139.46.77/32 => tun0x149f@192.0.2.11</PRE> -<A HREF="example5"></A> -<H3><A NAME="4_2_5">Example 5: Adding a Subnet to the VPN</A></H3> -<P>Suppose you wish to secure traffic to a subnet 192.0.2.192/29 behind - a FreeS/WAN box 192.0.2.12.</P> -<P>First, add DNS entries to configure 192.0.2.12 as an opportunistic - gateway for that subnet. Instructions are in our<A HREF="#opp.gate"> - quickstart guide</A>. Next, create a<VAR> private-net</VAR> group on - 192.0.2.12 as described in<A HREF="#example4"> Example 4</A>.</P> -<P>On each other host, add the subnet 192.0.2.192/29 to<VAR> private</VAR> -, yielding for example</P> -<PRE> [root@xy root]# cd /etc/ipsec.d/policies - [root@xy policies]# cat private - 192.0.2.9 # several hosts at example.com - 192.0.2.11 - 192.0.2.12 # HR department gateway - 192.0.2.192/29 # HR subnet - irc.private.example.com -</PRE> -<P>and reread policy groups with</P> -<PRE> ipsec auto --rereadgroups</PRE> -<P>That's all the configuration you need.</P> -<P>Test your VPN by pinging from a machine on 192.0.2.192/29 to any - other host:</P> -<PRE> [root@192.0.2.194]# ping 192.0.2.11</PRE> -<P>After a second or two, traffic should flow, and</P> -<PRE> ipsec eroute</PRE> -<P>should yield something like</P> -<PRE> 192.0.2.11/32 -> 192.0.2.194/32 => tun0x149f@192.0.2.12 -</PRE> -<P>Key:</P> -<TABLE> -<TR><TD>1.</TD><TD>192.0.2.11/32</TD><TD>Local start point of the - protected traffic.</TD></TR> -<TR><TD>2.</TD><TD>192.0.2.194/32</TD><TD>Remote end point of the - protected traffic.</TD></TR> -<TR><TD>3.</TD><TD>192.0.2.12</TD><TD>Remote FreeS/WAN node (gateway or - host). May be the same as (2).</TD></TR> -<TR><TD>4.</TD><TD>[not shown]</TD><TD>Local FreeS/WAN node (gateway or - host), where you've produced the output. May be the same as (1).</TD></TR> -</TABLE> -<P>For additional assurance, you can verify with a packet sniffer that - the traffic is being encrypted.</P> -<P>Note</P> -<UL> -<LI>Because strangers may also connect via OE, this type of VPN may - require a stricter firewalling policy than a conventional VPN.</LI> -</UL> -<H2><A NAME="4_3">Appendix</A></H2> -<A NAME="hiddenconn"></A> -<H3><A NAME="4_3_1">Our Hidden Connections</A></H3> -<P>Our Base Policy Groups are created using hidden connections. These - are spelled out in<A HREF="manpage.d/ipsec.conf.5.html"> man ipsec.conf</A> - and defined in<VAR> /usr/local/lib/ipsec/_confread</VAR>.</P> -<A NAME="custom_policygroups"></A> -<H3><A NAME="4_3_2">Custom Policy Groups</A></H3> -<P>A policy group is built using a special connection description in<VAR> - ipsec.conf</VAR>, which:</P> -<UL> -<LI>is<STRONG> generic</STRONG>. It uses<VAR> - right=[%group|%opportunisticgroup]</VAR> rather than specific IPs. The - connection is cloned for every name or IP range listed in its Policy - Group file.</LI> -<LI>often has a<STRONG> failure rule</STRONG>. This rule, written<VAR> - failureshunt=[passthrough|drop|reject|none]</VAR>, tells FreeS/WAN what - to do with packets for these CIDRs if it fails to establish the - connection. Default is<VAR> none</VAR>.</LI> -</UL> -<P>To create a new group:</P> -<OL> -<LI>Create its connection definition in<VAR> ipsec.conf</VAR>.</LI> -<LI>Create a Policy Group file in<VAR> /etc/ipsec.d/policies</VAR> with - the same name as your connection.</LI> -<LI>Put a CIDR block in that file.</LI> -<LI>Reread groups with<VAR> ipsec auto --rereadgroups</VAR>.</LI> -<LI>Test:<VAR> ping</VAR> to activate any OE connection, and view - results with<VAR> ipsec eroute</VAR>.</LI> -</OL> -<A NAME="disable_oe"></A><A NAME="disable_policygroups"></A> -<H3><A NAME="4_3_3">Disabling Opportunistic Encryption</A></H3> -<P>To disable OE (eg. policy groups and packetdefault), cut and paste - the following lines to<VAR> /etc/ipsec.conf</VAR>:</P> -<PRE>conn block - auto=ignore - -conn private - auto=ignore - -conn private-or-clear - auto=ignore - -conn clear-or-private - auto=ignore - -conn clear - auto=ignore - -conn packetdefault - auto=ignore</PRE> -<P>Restart FreeS/WAN so that the changes take effect:</P> -<PRE> ipsec setup restart</PRE> -<HR> -<H1><A NAME="5">FreeS/WAN FAQ</A></H1> -<P>This is a collection of questions and answers, mostly taken from the - FreeS/WAN<A href="mail.html"> mailing list</A>. See the project<A href="http://www.freeswan.org/"> - web site</A> for more information. All the FreeS/WAN documentation is - online there.</P> -<P>Contributions to the FAQ are welcome. Please send them to the project<A -href="mail.html"> mailing list</A>.</P> -<HR> -<H2><A name="questions">Index of FAQ questions</A></H2> -<UL> -<LI><A href="#whatzit">What is FreeS/WAN?</A></LI> -<LI><A href="#problems">How do I report a problem or seek help?</A></LI> -<LI><A href="#generic">Can I get ...</A> -<UL> -<LI><A href="#lemme_out">... an off-the-shelf system that includes - FreeS/WAN?</A></LI> -<LI><A href="#contractor">... contractors or staff who know FreeS/WAN?</A> -</LI> -<LI><A href="#commercial">... commercial support?</A></LI> -</UL> -</LI> -<LI><A href="#release">Release questions</A> -<UL> -<LI><A href="#rel.current">What is the current release?</A></LI> -<LI><A href="#relwhen">When is the next release?</A></LI> -<LI><A href="#rel.bugs">Are there known bugs in the current release?</A></LI> -</UL> -</LI> -<LI><A href="mod_cons">Modifications and contributions</A> -<UL> -<LI><A href="#modify.faq">Can I modify FreeS/WAN to ...?</A></LI> -<LI><A href="#contrib.faq">Can I contribute to the project?</A></LI> -<LI><A href="#ddoc.faq">Is there detailed design documentation?</A></LI> -</UL> -</LI> -<LI><A href="#interact">Will FreeS/WAN work in my environment?</A> -<UL> -<LI><A href="#interop.faq">Can FreeS/WAN talk to ... ?</A></LI> -<LI><A href="#old_to_new">Can different FreeS/WAN versions talk to each - other?</A></LI> -<LI><A href="#faq.bandwidth">Is there a limit on throughput?</A></LI> -<LI><A href="#faq.number">Is there a limit on number of connections?</A></LI> -<LI><A href="#faq.speed">Is a ... fast enough to handle FreeS/WAN with - my loads?</A></LI> -</UL> -</LI> -<LI><A href="#work_on">Will FreeS/WAN work on ...</A> -<UL> -<LI><A href="#versions">... my version of Linux?</A></LI> -<LI><A href="#nonIntel.faq">... non-Intel CPUs?</A></LI> -<LI><A href="#multi.faq">... multiprocessors?</A></LI> -<LI><A href="#k.old">... an older kernel?</A></LI> -<LI><A href="#k.versions">... the latest kernel version?</A></LI> -<LI><A href="#interface.faq">... unusual network hardware?</A></LI> -<LI><A href="#vlan">... a VLAN (802.1q) network?</A></LI> -</UL> -</LI> -<LI><A href="#features.faq">Does FreeS/WAN support ...</A> -<UL> -<LI><A href="#VPN.faq">... site-to-site VPN applications</A></LI> -<LI><A href="#warrior.faq">... remote users connecting to a LAN</A></LI> -<LI><A href="#road.shared.possible">... remote users using shared secret - authentication?</A></LI> -<LI><A href="#wireless.faq">... wireless networks</A></LI> -<LI><A href="#PKIcert">... X.509 or other PKI certificates?</A></LI> -<LI><A href="#Radius">... user authentication (Radius, SecureID, Smart - Card ...)?</A></LI> -<LI><A href="#NATtraversal">... NAT traversal</A></LI> -<LI><A href="#virtID">... assigning a "virtual identity" to a remote - system?</A></LI> -<LI><A href="#noDES.faq">... single DES encryption?</A></LI> -<LI><A href="#AES.faq">... AES encryption?</A></LI> -<LI><A href="#other.cipher">... other encryption algorithms?</A></LI> -</UL> -</LI> -<LI><A href="#canI">Can I ...</A> -<UL> -<LI><A href="#policy.preconfig">...use policy groups along with - explicitly configured connections?</A></LI> -<LI><A href="#policy.off">...turn off policy groups?</A></LI> - -<!-- - <li><a href="#policy.otherinterface">...use policy groups - on an interface other than <VAR>%defaultroute</VAR>?</a></li> ---> -<LI><A href="#reload">... reload connection info without restarting?</A></LI> -<LI><A href="#masq.faq">... use several masqueraded subnets?</A></LI> -<LI><A href="#dup_route">... use subnets masqueraded to the same - addresses?</A></LI> -<LI><A href="#road.masq">... assign a road warrior an address on my net - (a virtual identity)?</A></LI> -<LI><A href="#road.many">... support many road warriors with one - gateway?</A></LI> -<LI><A href="#road.PSK">... have many road warriors using shared secret - authentication?</A></LI> -<LI><A href="#QoS">... use Quality of Service routing with FreeS/WAN?</A> -</LI> -<LI><A href="#deadtunnel">... recognise dead tunnels and shut them down?</A> -</LI> -<LI><A href="#demanddial">... build IPsec tunnels over a demand-dialed - link?</A></LI> -<LI><A href="#GRE">... build GRE, L2TP or PPTP tunnels over IPsec?</A></LI> -<LI><A href="#NetBIOS">... use Network Neighborhood (Samba, NetBIOS) - over IPsec?</A></LI> -</UL> -</LI> -<LI><A href="#setup.faq">Life's little mysteries</A> -<UL> -<LI><A href="#cantping">I cannot ping ....</A></LI> -<LI><A href="#forever">It takes forever to ...</A></LI> -<LI><A href="#route">I send packets to the tunnel with route(8) but they - vanish</A></LI> -<LI><A href="#down_route">When a tunnel goes down, packets vanish</A></LI> -<LI><A href="#firewall_ate">The firewall ate my packets!</A></LI> -<LI><A href="#dropconn">Dropped connections</A></LI> -<LI><A href="#defaultroutegone">Disappearing %defaultroute</A></LI> -<LI><A href="#tcpdump.faq">TCPdump on the gateway shows strange things</A> -</LI> -<LI><A href="#no_trace">Traceroute does not show anything between the - gateways</A></LI> -</UL> -</LI> -<LI><A href="#man4debug">Testing in stages (or .... works but ... - doesn't)</A> -<UL> -<LI><A href="#nomanual">Manually keyed connections don't work</A></LI> -<LI><A href="#spi_error">One manual connection works, but second one - fails</A></LI> -<LI><A href="#man_no_auto">Manual connections work, but automatic keying - doesn't</A></LI> -<LI><A href="#nocomp">IPsec works, but connections using compression - fail</A></LI> -<LI><A href="#pmtu.broken">Small packets work, but large transfers fail</A> -</LI> -<LI><A href="#subsub">Subnet-to-subnet works, but tests from the - gateways don't</A></LI> -</UL> -</LI> -<LI><A href="#compile.faq">Compilation problems</A> -<UL> -<LI><A href="#gmp.h_missing">gmp.h: No such file or directory</A></LI> -<LI><A href="#noVM">... virtual memory exhausted</A></LI> -</UL> -</LI> -<LI><A href="#error">Interpreting error messages</A> -<UL> -<LI><A href="#route-client">route-client (or host) exited with status 7</A> -</LI> -<LI><A href="#unreachable">SIOCADDRT:Network is unreachable</A></LI> -<LI><A href="#modprobe">ipsec_setup: modprobe: Can't locate moduleipsec</A> -</LI> -<LI><A href="#noKLIPS">ipsec_setup: Fatal error, kernel appears to lack - KLIPS</A></LI> -<LI><A href="#noDNS">ipsec_setup: ... failure to fetch key for ... from - DNS</A></LI> -<LI><A href="#dup_address">ipsec_setup: ... interfaces ... and ... share - address ...</A></LI> -<LI><A href="#kflags">ipsec_setup: Cannot adjust kernel flags</A></LI> -<LI><A href="#message_num">Message numbers (MI3, QR1, et cetera) in - Pluto messages</A></LI> -<LI><A href="#conn_name">Connection names in Pluto error messages</A></LI> -<LI><A href="#cantorient">Pluto: ... can't orient connection</A></LI> -<LI><A href="#no.interface">... we have no ipsecN interface for either - end of this connection</A></LI> -<LI><A href="#noconn">Pluto: ... no connection is known</A></LI> -<LI><A href="#nosuit">Pluto: ... no suitable connection ...</A></LI> -<LI><A href="#noconn.auth">Pluto: ... no connection has been authorized</A> -</LI> -<LI><A href="#noDESsupport">Pluto: ... OAKLEY_DES_CBC is not supported.</A> -</LI> -<LI><A href="#notransform">Pluto: ... no acceptable transform</A></LI> -<LI><A href="#rsasigkey">rsasigkey dumps core</A></LI> -<LI><A href="#sig4">!Pluto failure!: ... exited with ... signal 4</A></LI> -<LI><A href="#econnrefused">ECONNREFUSED error message</A></LI> -<LI><A href="#no_eroute">klips_debug: ... no eroute!</A></LI> -<LI><A href="#SAused">... trouble writing to /dev/ipsec ... SA already - in use</A></LI> -<LI><A href="#ignore">... ignoring ... payload</A></LI> -<LI><A href="#unknown_rightcert">unknown parameter name "rightcert"</A></LI> -</UL> -</LI> -<LI><A href="#spam">Why don't you restrict the mailing lists to reduce - spam?</A></LI> -</UL> -<HR> -<H2><A name="whatzit">What is FreeS/WAN?</A></H2> -<P>FreeS/WAN is a Linux implementation of the<A href="#IPSEC"> IPsec</A> - protocols, providing security services at the IP (Internet Protocol) - level of the network.</P> -<P>For more detail, see our<A href="intro.html"> introduction</A> - document or the FreeS/WAN project<A href="http://www.freeswan.org/"> - web site</A>.</P> -<P>To start setting it up, go to our<A href="quickstart.html"> - quickstart guide</A>.</P> -<P>Our<A href="web.html"> web links</A> document has information on<A href="#implement"> - IPsec for other systems</A>.</P> -<H2><A name="problems">How do I report a problem or seek help?</A></H2> -<DL> -<DT>Read our<A href="trouble.html"> troubleshooting</A> document.</DT> -<DD> -<P>It may guide you to a solution. If not, see its<A href="#prob.report"> - problem reporting</A> section.</P> -<P>Basically, what it says is<STRONG> give us the output from<VAR> ipsec - barf</VAR> from both gateways</STRONG>. Without full information, we - cannot diagnose a problem. However,<VAR> ipsec barf</VAR> produces a - lot of output. If at all possible,<STRONG> please make barfs accessible - via the web or FTP</STRONG> rather than sending enormous mail messages.</P> -</DD> -<DT><STRONG>Use the<A href="mail.html"> users mailing list</A> for - problem reports</STRONG>, rather than mailing developers directly.</DT> -<DD> -<UL> -<LI>This gives you access to more expertise, including users who may - have encountered and solved the same problems.</LI> -<LI>It is more likely to get a quick response. Developers may get behind - on email, or even ignore it entirely for a while, but a list message - (given a reasonable Subject: line) is certain to be read by a fair - number of people within hours.</LI> -<LI>It may also be important because of<A href="#exlaw"> cryptography - export laws</A>. A US citizen who provides technical assistance to - foreign cryptographic work might be charged under the arms export - regulations. Such a charge would be easier to defend if the discussion - took place on a public mailing list than if it were done in private - mail.</LI> -</UL> -</DD> -<DT>Try irc.freenode.net#freeswan.</DT> -<DD> -<P>FreeS/WAN developers, volunteers and users can often be found there. - Be patient and be prepared to provide lots of information to support - your question.</P> -<P>If your question was really interesting, and you found an answer, - please share that with the class by posting to the<A href="mail.html"> - users mailing list</A>. That way others with the same problem can find - your answer in the archives.</P> -</DD> -<DT>Premium support is also available.</DT> -<DD> -<P>See the next several questions.</P> -</DD> -</DL> -<H2><A name="generic">Can I get ...</A></H2> -<H3><A name="lemme_out">Can I get an off-the-shelf system that includes - FreeS/WAN?</A></H3> -<P>There are a number of Linux distributions or firewall products which - include FreeS/WAN. See this<A href="#products"> list</A>. Using one of - these, chosen to match your requirements and budget, may save you - considerable time and effort.</P> -<P>If you don't know your requirements, start by reading Schneier's<A href="#secrets"> - Secrets and Lies</A>. That gives the best overview of security issues I - have seen. Then consider hiring a consultant (see next question) to - help define your requirements.</P> -<H3><A name="consultant">Can I hire consultants or staff who know - FreeS/WAN?</A></H3> -<P>If you want the help of a contractor, or to hire staff with FreeS/WAN - expertise, you could:</P> -<UL> -<LI>check availability in your area through your local Linux User Group - (<A href="http://lugww.counter.li.org/">LUG Index</A>)</LI> -<LI>try asking on our<A href="mail.html"> mailing list</A></LI> -</UL> -<P>For companies offerring support, see the next question.</P> -<H3><A name="commercial">Can I get commercial support?</A></H3> -<P>Many of the distributions or firewall products which include - FreeS/WAN (see this<A href="#products"> list</A>) come with commercial - support or have it available as an option.</P> -<P>Various companies specialize in commercial support of open source - software. Our project leader was a founder of the first such company, - Cygnus Support. It has since been bought by<A href="http://www.redhat.com"> - Redhat</A>. Another such firm is<A href="http://www.linuxcare.com"> - Linuxcare</A>.</P> -<H2><A name="release">Release questions</A></H2> -<H3><A name="rel.current">What is the current release?</A></H3> -<P>The current release is the highest-numbered tarball on our<A href="ftp://ftp.xs4all.nl/pub/crypto/freeswan"> - distribution site</A>. Almost always, any of<A href="#mirrors"> the - mirrors</A> will have the same file, though perhaps not for a day or so - after a release.</P> -<P>Unfortunately, the web site is not always updated as quickly as it - should be.</P> -<H3><A name="relwhen">When is the next release?</A></H3> -<P>We try to do a release approximately every six to eight weeks.</P> -<P>If pre-release tests fail and the fix appears complex, or more - generally if the code does not appear stable when a release is - scheduled, we will just skip that release.</P> -<P>For serious bugs, we may bring out an extra bug-fix release. These - get numbers in the normal release series. For example, there was a bug - found in FreeS/WAN 1.6, so we did another release less than two weeks - later. The bug-fix release was called 1.7.</P> -<H3><A name="rel.bugs">Are there known bugs in the current release?</A></H3> -<P>Any problems we are aware of at the time of a release are documented - in the<A href="../BUGS"> BUGS</A> file for that release. You should - also look at the<A href="../CHANGES"> CHANGES</A> file.</P> -<P>Bugs discovered after a release are discussed on the<A href="mail.html"> - mailing lists</A>. The easiest way to check for any problems in the - current code would be to peruse the<A href="http://lists.freeswan.org/pipermail/briefs"> - List In Brief</A>.</P> -<H2><A name="mod_cons">Modifications and contributions</A></H2> -<H3><A name="modify.faq">Can I modify FreeS/WAN to ...?</A></H3> -<P>You are free to modify FreeS/WAN in any way. See the discussion of<A href="#licensing"> - licensing</A> in our introduction document.</P> -<P>Before investing much energy in any such project, we suggest that you</P> -<UL> -<LI>check the list of<A href="#patch"> existing patches</A></LI> -<LI>post something about your project to the<A href="mail.html"> design - mailing list</A></LI> -</UL> -<P>This may prevent duplicated effort, or lead to interesting - collaborations.</P> -<H3><A name="contrib.faq">Can I contribute to the project?</A></H3> - In general, we welcome contributions from the community. Various - contributed patches, either to fix bugs or to add features, have been - incorporated into our distribution. Other patches, not yet included in - the distribution, are listed in our<A href="#patch"> web links</A> - section. -<P>Users have also contributed heavily to documentation, both by - creating their own<A href="#howto"> HowTos</A> and by posting things on - the<A href="mail.html"> mailing lists</A> which I have quoted in these - HTML docs.</P> -<P>There are, however, some caveats.</P> -<P>FreeS/WAN is being implemented in Canada, by Canadians, largely to - ensure that is it is entirely free of export restrictions. See this<A href="#status"> - discussion</A>. We<STRONG> cannot accept code contributions from US - residents or citizens</STRONG>, not even one-line bugs fixes. The - reasons for this were recently discussed extensively on the mailing - list, in a thread starting<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/01/msg00111.html"> - here</A>.</P> -<P>Not all contributions are of interest to us. The project has a set of - fairly ambitious and quite specific goals, described in our<A href="#goals"> - introduction</A>. Contributions that lead toward these goals are likely - to be welcomed enthusiastically. Other contributions may be seen as - lower priority, or even as a distraction.</P> -<P>Discussion of possible contributions takes place on the<A href="mail.html"> - design mailing list</A>.</P> -<H3><A name="ddoc.faq">Is there detailed design documentation?</A></H3> - There are: -<UL> -<LI><A href="rfc.html">RFCs</A> specifying the protocols we implement</LI> -<LI><A href="manpages.html">man pages</A> for our utilities, library - functions and file formats</LI> -<LI>comments in the source code</LI> -<LI><A href="index.html">HTML documentation</A> written primarily for - users</LI> -<LI>archived discussions from the<A href="mail.html"> mailing lists</A></LI> -<LI>other papers mentioned in our<A href="#applied"> introduction</A></LI> -</UL> -<P>The only formal design documents are a few papers in the last - category above. All the other categories, however, have things to say - about design as well.</P> -<H2><A name="interact">Will FreeS/WAN work in my environment?</A></H2> -<H3><A name="interop.faq">Can FreeS/WAN talk to ...?</A></H3> -<P>The IPsec protocols are designed to support interoperation. In - theory, any two IPsec implementations should be able to talk to each - other. In practice, it is considerably more complex. We have a whole<A href="interop.html"> - interoperation document</A> devoted to this problem.</P> -<P>An important part of that document is links to the many<A href="interop.html#otherpub"> - user-written HowTos</A> on interoperation between FreeS/WAN and various - other implementations. Often the users know more than the developers - about these issues (and almost always more than me :-), so these - documents may be your best resource.</P> -<H3><A name="old_to_new">Can different FreeS/WAN versions talk to each - other?</A></H3> -<P>Linux FreeS/WAN can interoperate with many IPsec implementations, - including earlier versions of Linux FreeS/WAN itself.</P> -<P>In a few cases, there are some complications. See our<A href="interop.html#oldswan"> - interoperation</A> document for details.</P> -<H3><A name="faq.bandwidth">Is there a limit on throughput?</A></H3> -<P>There is no hard limit, but see below.</P> -<H3><A name="faq.number">Is there a limit on number of tunnels?</A></H3> -<P>There is no hard limit, but see next question.</P> -<H3><A name="faq.speed">Is a ... fast enough to handle FreeS/WAN with my - loads?</A></H3> -<P>A quick summary:</P> -<DL> -<DT>Even a limited machine can be useful</DT> -<DD>A 486 can handle a T1, ADSL or cable link, though the machine may be - breathing hard.</DD> -<DT>A mid-range PC (say 800 MHz with good network cards) can do a lot of - IPsec</DT> -<DD>With up to roughly 50 tunnels and aggregate bandwidth of 20 Megabits - per second, it willl have cycles left over for other tasks.</DD> -<DT>There are limits</DT> -<DD>Even a high end CPU will not come close to handling a fully loaded - 100 Mbit/second Ethernet link. -<P>Beyond about 50 tunnels it needs careful management.</P> -</DD> -</DL> -<P>See our<A href="performance.html"> FreeS/WAN performance</A> document - for details.</P> -<H2><A name="work_on">Will FreeS/WAN work on ... ?</A></H2> -<H3><A name="versions">Will FreeS/WAN run on my version of Linux?</A></H3> -<P>We build and test on Redhat distributions, but FreeS/WAN runs just - fine on several other distributions, sometimes with minor fiddles to - adapt to the local environment. Details are in our<A href="#otherdist"> - compatibility</A> document. Also, some distributions or products come - with<A href="#products"> FreeS/WAN included</A>.</P> -<H3><A name="nonIntel.faq">Will FreeS/WAN run on non-Intel CPUs?</A></H3> -<P>FreeS/WAN is<STRONG> intended to run on all CPUs Linux supports</STRONG> -. We know of it being used in production on x86, ARM, Alpha and MIPS. It - has also had successful tests on PPC and SPARC, though we don't know of - actual use there. Details are in our<A href="#CPUs"> compatibility</A> - document.</P> -<H3><A name="multi.faq">Will FreeS/WAN run on multiprocessors?</A></H3> -<P>FreeS/WAN is designed to work on any SMP architecture Linux supports, - and has been tested successfully on at least dual processor Intel - architecture machines. Details are in our<A href="#multiprocessor"> - compatibility</A> document.</P> -<H3><A name="k.old">Will FreeS/WAN work on an older kernel?</A></H3> -<P>It might, but we strongly recommend using a recent 2.2 or 2.4 series - kernel. Sometimes the newer versions include security fixes which can - be quite important on a gateway.</P> -<P>Also, we use recent kernels for development and testing, so those are - better tested and, if you do encounter a problem, more easily - supported. If something breaks applying recent FreeS/WAN patches to an - older kernel, then "update your kernel" is almost certain to be the - first thing we suggest. It may be the only suggestion we have.</P> -<P>The precise kernel versions supported by a particular FreeS/WAN - release are given in the<A href="XX"> README</A> file of that release.</P> -<P>See the following question for more on kernels.</P> -<H3><A name="k.versions">Will FreeS/WAN run on the latest kernel - version?</A></H3> -<P>Sometimes yes, but quite often, no.</P> -<P>Kernel versions supported are given in the<A href="../README"> README</A> - file of each FreeS/WAN release. Typically, they are whatever production - kernels were current at the time of our release (or shortly before; we - might release for kernel<VAR> n</VAR> just as Linus releases<VAR> n+1</VAR> -). Often FreeS/WAN will work on slightly later kernels as well, but of - course this cannot be guaranteed.</P> -<P>For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, - the current kernels at the time. It also worked on 2.4.6, 2.4.7 and - 2.4.8, but 2.4.9 had changes that caused compilation errors if it was - patched with FreeS/WAN 1.91.</P> -<P>When such changes appear, we put a fix in the FreeS/WAN snapshots, - and distribute it with our next release. However, this is not a high - priority for us, and it may take anything from a few days to several - weeks for such a problem to find its way to the top of our kernel - programmer's To-Do list. In the meanwhile, you have two choices:</P> -<UL> -<LI>either stick with a slightly older kernel, even if it is not the - latest and greatest. This is recommended for production systems; new - versions may have new bugs.</LI> -<LI>or fix the problem yourself and send us a patch, via the<A href="mail.html"> - Users mailing list</A>.</LI> -</UL> -<P>We don't even try to keep up with kernel changes outside the main 2.2 - and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox - or the 2.5 series of development kernels. We'd rather work on - developing the FreeS/WAN code than on chasing these moving targets. We - are, however, happy to get patches for problems discovered there.</P> -<P>See also the<A href="install.html#choosek"> Choosing a kernel</A> - section of our installation document.</P> -<H3><A name="interface.faq">Will FreeS/WAN work on unusual network - hardware?</A></H3> -<P>IPsec is designed to work over any network that IP works over, and - FreeS/WAN is intended to work over any network interface hardware that - Linux supports.</P> -<P>If you have working IP on some unusual interface -- perhaps Arcnet, - Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".</P> -<P>That said, practice is sometimes less tractable than theory. Our - testing is done almost entirely on:</P> -<UL> -<LI>10 or 100 Mbit Ethernet</LI> -<LI>ADSL or cable connections, with and without PPPoE</LI> -<LI>IEEE 802.11 wireless LANs (see<A href="#wireless.faq"> below</A>)</LI> -</UL> -<P>If you have some other interface, especially an uncommon one, it is - entirely possible you will get bitten either by a FreeS/WAN bug which - our testing did not turn up, or by a bug in the driver that shows up - only with our loads.</P> -<P>If IP works on your interface and FreeS/WAN doesn't, seek help on the<A -href="mail.html"> mailing lists</A>.</P> -<P>Another FAQ section describes<A href="#pmtu.broken"> MTU problems</A> -. These are a possibility for some interfaces.</P> -<H3><A name="vlan">Will FreeS/WAN work on a VLAN (802.1q) network?</A></H3> -<P> Yes, FreeSwan works fine, though some network drivers have problems - with jumbo sized ethernet frames. If you used interfaces=%defaultroute - you do not need to change anything, but if you specified an interface - (eg eth0) then remember you must change that to reflect the VLAN - interface (eg eth0.2 for VLAN ID 2).</P> -<P> The "eepro100" module is known to be broken, use the e100 driver for - those cards instead (included in 2.4 as 'alternative driver' for the - Intel EtherExpressPro/100.</P> -<P> You do not need to change any MTU setting (those are workarounds - that are only needed for buggy drivers)</P> -<P><EM>This FAQ contributed by Paul Wouters.</EM></P> -<H2><A name="features.faq">Does FreeS/WAN support ...</A></H2> -<P>For a discussion of which parts of the IPsec specifications FreeS/WAN - does and does not implement, see our<A href="#spec"> compatibility</A> - document.</P> -<P>For information on some often-requested features, see below.</P> -<H3><A name="VPN.faq"></A>Does FreeS/WAN support site-to-site VPN (<A HREF="#VPN"> -Virtual Private Network</A>) applications?</H3> -<P>Absolutely. See this FreeS/WAN-FreeS/WAN<A HREF="config.html"> - configuration example</A>. If only one site is using FreeS/WAN, there - may be a relevant HOWTO on our<A HREF="interop.html"> interop page</A>.</P> -<H3><A name="warrior.faq">Does FreeS/WAN support remote users connecting - to a LAN?</A></H3> -<P>Yes. We call the remote users "Road Warriors". Check out our - FreeS/WAN-FreeS/WAN<A HREF="#config.rw"> Road Warrior Configuration - Example</A>.</P> -<P>If your Road Warrior is a Windows or Mac PC, you may need to install - an IPsec implementation on that machine. Our<A HREF="interop.html"> - interop</A> page lists many available brands, and features links to - several HOWTOs.</P> -<H3><A name="road.shared.possible">Does FreeS/WAN support remote users - using shared secret authentication?</A></H3> -<P><STRONG>Yes, but</STRONG> there are severe restrictions, so<STRONG> - we strongly recommend using</STRONG><A href="#RSA"><STRONG> RSA</STRONG> -</A><STRONG> keys for</STRONG><A href="#authentication"><STRONG> - authentication</STRONG></A><STRONG> instead</STRONG>.</P> -<P>See this<A href="#road.PSK"> FAQ question</A>.</P> -<H3><A name="wireless.faq">Does FreeS/WAN support wireless networks?</A></H3> -<P>Yes, it is a common practice to use IPsec over wireless networks - because their built-in encryption,<A href="#WEP"> WEP</A>, is insecure.</P> -<P>There is some<A href="#wireless.config"> discussion</A> in our - advanced configuration document. See also the<A HREF="http://www.wavesec.org"> - WaveSEC site</A>.</P> -<H3><A name="PKIcert">Does FreeS/WAN support X.509 or other PKI - certificates?</A></H3> -<P>Vanilla FreeS/WAN does not support X.509, but Andreas Steffen and - others have provided a popular, well-supported X.509 patch.</P> -<UL> -<LI><A HREF="http://www.strongsec.com/freeswan">patch</A></LI> -<LI><A HREF="http://www.freeswan.ca">Super FreeS/WAN</A> incorporates - this and other user-contributed patches.</LI> -<LI> Kai Martius'<A HREF="http://www.strongsec.com/freeswan/install.htm"> - X.509 Installation and Configuration Guide</A></LI> -</UL> -<P> Linux FreeS/WAN features<A HREF="quickstart.html"> Opportunistic - Encryption</A>, an alternative Public Key Infrastructure based on - Secure DNS.</P> -<H3><A name="Radius">Does FreeS/WAN support user authentication (Radius, - SecureID, Smart Card...)?</A></H3> -<P>Andreas Steffen's<A HREF="http://www.strongsec.com/freeswan"> X.509 - patch</A> (v. 1.42+) supports Smart Cards. The patch does not ship with - vanilla FreeS/WAN, but will be incorporated into<A HREF="http://www.freeswan.ca/"> - Super FreeS/WAN 2.01+</A>. The patch implements the PCKS#15 - Cryptographic Token Information Format Standard, using the OpenSC - smartcard library functions.</P> -<P>Older news:</P> -<P>A user-supported patch to FreeS/WAN 1.3, for smart card style - authentication, is available on<A HREF="http://alcatraz.webcriminals.com/~bastiaan/ipsec"> - Bastiaan's site</A>. It supports skeyid and ibutton. This patch is not - part of Super FreeS/WAN.</P> -<P>For a while progress on this front was impeded by a lack of standard. - The IETF<A href="http://www.ietf.org/html.charters/ipsra-charter.html"> - working group</A> has now nearly completed its recommended solution to - the problem; meanwhile several vendors have implemented various things.</P> - -<!-- -<p>The <a href="web.html#patch">patches</a> section of our web links document -has links to some user work on this.</p> ---> -<P>Of course, there are various ways to avoid any requirement for user - authentication in IPsec. Consider the situation where road warriors - build IPsec tunnels to your office net and you are considering - requiring user authentication during tunnel negotiation. Alternatives - include:</P> -<UL> -<LI>If you can trust the road warrior machines, then set them up so that - only authorised users can create tunnels. If your road warriors use - laptops, consider the possibility of theft.</LI> -<LI>If the tunnel only provides access to particular servers and you can - trust those servers, then set the servers up to require user - authentication.</LI> -</UL> -<P>If either of those is trustworthy, it is not clear that you need user - authentication in IPsec.</P> -<H3><A name="NATtraversal">Does FreeS/WAN support NAT traversal?</A></H3> -<P>Vanilla FreeS/WAN does not, but thanks to Mathieu Lafon and Arkoon - Network Security, there's a patch to support this.</P> -<UL> -<LI><A HREF="http://open-source.arkoon.net">patch and documentation</A></LI> -<LI><A HREF="http://www.freeswan.ca">Super FreeS/WAN</A> incorporates - this and other user-contributed patches.</LI> -</UL> -<P>The NAT traversal patch has some issues with PSKs, so you may wish to - authenticate with RSA keys, or X.509 (requires a patch which is also - included in Super FreeS/WAN). Doing the latter also has advantages when - dealing with large numbers of clients who may be behind NAT; instead of - having to make an individual Roadwarrior connection for each virtual - IP, you can use the "rightsubnetwithin" parameter to specify a range. - See<A HREF="http://www.strongsec.com/freeswan/install.htm#section_4.4"> - these<VAR> rightsubnetwithin</VAR> instructions</A>.</P> -<H3><A name="virtID">Does FreeS/WAN support assigning a "virtual - identity" to a remote system?</A></H3> -<P>Some IPsec implementations allow you to make the source address on - packets sent by a Road Warrior machine be something other than the - address of its interface to the Internet. This is sometimes described - as assigning a virtual identity to that machine.</P> -<P>FreeS/WAN does not directly support this, but it can be done. See - this<A href="#road.masq"> FAQ question</A>.</P> -<H3><A name="noDES.faq">Does FreeS/WAN support single DES encryption?</A> -</H3> -<P><STRONG>No</STRONG>, single DES is not used either at the<A href="#IKE"> - IKE</A> level for negotiating connections or at the<A href="#IPSEC"> - IPsec</A> level for actually building them.</P> -<P>Single DES is<A href="#desnotsecure"> insecure</A>. As we see it, it - is more important to deliver real security than to comply with a - standard which has been subverted into allowing use of inadequate - methods. See this<A href="#weak"> discussion</A>.</P> -<P>If you want to interoperate with an IPsec implementation which offers - only DES, see our<A href="interop.html#noDES"> interoperation</A> - document.</P> -<H3><A name="AES.faq">Does FreeS/WAN support AES encryption?</A></H3> -<P><A href="#AES">AES</A> is a new US government<A href="#block"> block - cipher</A> standard to replace the obsolete<A href="#DES"> DES</A>.</P> -<P>At time of writing (March 2002), the FreeS/WAN distribution does not - yet support AES but user-written<A href="#patch"> patches</A> are - available to add it. Our kernel programmer is working on integrating - those patches into the distribution, and there is active discussion of - this on the design mailimg list.</P> -<H3><A name="other.cipher">Does FreeS/WAN support other encryption - algorithms?</A></H3> -<P>Currently<A href="#3DES"> triple DES</A> is the only cipher - supported. AES will almost certainly be added (see previous question), - and it is likely that in the process we will also add the other two AES - finalists with open licensing, Twofish and Serpent.</P> -<P>We are extremely reluctant to add other ciphers. This would make both - use and maintenance of FreeS/WAN more complex without providing any - clear benefit. Complexity is emphatically not desirable in a security - product.</P> -<P>Various users have written patches to add other ciphers. We provide<A href="#patch"> - links</A> to these.</P> -<H2><A name="canI">Can I ...</A></H2> -<H3><A name="policy.preconfig">Can I use policy groups along with - explicitly configured connections?</A></H3> -<P>Yes, you can, so long as you pay attention to the selection rule, - which can be summarized "the most specific connection wins". We - describe the rule in our<A HREF="#policy.group.notes"> policy groups</A> - document, and provide a more technical explanation in<A HREF="manpage.d/ipsec.conf.5.html"> - man ipsec.conf</A>.</P> -<P>A good guideline: If you have a regular connection defined in<VAR> - ipsec.conf</VAR>, ensure that a subset of that connection is not listed - in a less restrictive policy group. Otherwise, FreeS/WAN will use the - subset, with its more specific source/destination pair.</P> -<P>Here's an example. Suppose you are the system administrator at - 192.0.2.2. You have this connection in ipsec.conf:<VAR> ipsec.conf</VAR> -:</P> -<PRE>conn net-to-net - left=192.0.2.2 # you are here - right=192.0.2.8 - rightsubnet=192.0.2.96/27 - .... -</PRE> -<P>If you then place a host or net within<VAR> rightsubnet</VAR>, (let's - say 192.0.2.98) in<VAR> private-or-clear</VAR>, you may find that - 192.0.2.2 at times communicates in the clear with 192.0.2.98. That's - consistent with the rule, but may be contrary to your expectations.</P> -<P>On the other hand, it's safe to put a larger subnet in a less - restrictive policy group file. If<VAR> private-or-clear</VAR> contains - 192.0.2.0/24, then the more specific<VAR> net-to-net</VAR> connection - is used for any communication to 192.0.2.96/27. The more general policy - applies only to communication with hosts or subnets in 192.0.2.0/24 - without a more specific policy or connection.</P> -<H3><A name="policy.off">Can I turn off policy groups?</A></H3> -<P>Yes. Use<A HREF="#disable_policygroups"> these instructions</A>.</P> - -<!-- -<h3><a name="policy.otherinterface">Can I use policy groups - on an interface other than <VAR>%defaultroute</VAR>?</a></h3> - -<p>??<p> ---> -<H3><A name="reload">Can I reload connection info without restarting?</A> -</H3> -<P>Yes, you can do this. Here are the details, in a mailing list message - from Pluto programmer Hugh Redelmeier:</P> -<PRE>| How can I reload config's without restarting all of pluto and klips? I am using -| FreeSWAN -> PGPNet in a medium sized production environment, and would like to be -| able to add new connections ( i am using include config/* ) without dropping current -| SA's. -| -| Can this be done? -| -| If not, are there plans to add this kind of feature? - - ipsec auto --add whatever -This will look in the usual place (/etc/ipsec.conf) for a conn named -whatever and add it. - -If you added new secrets, you need to do - ipsec auto --rereadsecrets -before Pluto needs to know those secrets. - -| I have looked (perhaps not thoroughly enough tho) to see how to do this: - -There may be more bits to look for, depending on what you are trying -to do.</PRE> -<P>Another useful command here is<VAR> ipsec auto --replace <conn_name></VAR> - which re-reads data for a named connection.</P> -<H3><A name="masq.faq">Can I use several masqueraded subnets?</A></H3> -<P>Yes. This is done all the time. See the discussion in our<A href="config.html#route_or_not"> - setup</A> document. The only restriction is that the subnets on the two - ends must not overlap. See the next question.</P> -<P>Here is a mailing list message on the topic. The user incorrectly - thinks you need a 2.4 kernel for this -- actually various people have - been doing it on 2.0 and 2.2 for quite some time -- but he has it right - for 2.4.</P> -<PRE>Subject: Double NAT and freeswan working :) - Date: Sun, 11 Mar 2001 - From: Paul Wouters <paul@xtdnet.nl> - -Just to share my pleasure, and make an entry for people who are searching -the net on how to do this. Here's the very simple solution to have a double -NAT'ed network working with freeswan. (Not sure if this is old news, but I'm -not on the list (too much spam) and I didn't read this in any HOWTO/FAQ/doc -on the freeswan site yet (Sandy, put it in! :) - -10.0.0.0/24 --- 10.0.0.1 a.b.c.d ---- a.b.c.e {internet} ----+ - | -10.0.1.0/24 --- 10.0.1.1 f.g.h.i ---- f.g.h.j {internet} ----+ - -the goal is to have the first network do a VPN to the second one, yet also -have NAT in place for connections not destinated for the other side of the -NAT. Here the two Linux security gateways have one real IP number (cable -modem, dialup, whatever. - -The problem with NAT is you don't want packets from 10.*.*.* to 10.*.*.* -to be NAT'ed. While with Linux 2.2, you can't, with Linux 2.4 you can. - -(This has been tested and works for 2.4.2 with Freeswan snapshot2001mar8b) - -relevant parts of /etc/ipsec.conf: - - left=f.g.h.i - leftsubnet=10.0.1.0/24 - leftnexthop=f.g.h.j - leftfirewall=yes - leftid=@firewall.netone.nl - leftrsasigkey=0x0........ - right=a.b.c.d - rightsubnet=10.0.0.0/24 - rightnexthop=a.b.c.e - rightfirewall=yes - rightid=@firewall.nettwo.nl - rightrsasigkey=0x0...... - # To authorize this connection, but not actually start it, at startup, - # uncomment this. - auto=add - -and now the real trick. Setup the NAT correctly on both sites: - -iptables -t nat -F -iptables -t nat -A POSTROUTING -o eth0 -d \! 10.0.0.0/8 -j MASQUERADE - -This tells the NAT code to only do NAT for packets with destination other then -10.* networks. note the backslash to mask the exclamation mark to protect it -against the shell. - -Happy painting :) - -Paul</PRE> -<H3><A name="dup_route">Can I use subnets masqueraded to the same - addresses?</A></H3> -<P><STRONG>No.</STRONG> The notion that IP addresses are unique is one - of the fundamental principles of the IP protocol. Messing with it is - exceedingly perilous.</P> -<P>Fairly often a situation comes up where a company has several - branches, all using the same<A href="#non-routable"> non-routable - addresses</A>, perhaps 192.168.0.0/24. This works fine as long as those - nets are kept distinct. The<A href="#masq"> IP masquerading</A> on - their firewalls ensures that packets reaching the Internet carry the - firewall address, not the private address.</P> -<P>This can break down when IPsec enters the picture. FreeS/WAN builds a - tunnel that pokes through both masquerades and delivers packets from<VAR> - leftsubnet</VAR> to<VAR> rightsubnet</VAR> and vice versa. For this to - work, the two subnets<EM> must</EM> be distinct.</P> -<P>There are several solutions to this problem.</P> -<P>Usually, you<STRONG> re-number the subnets</STRONG>. Perhaps the - Vancouver office becomes 192.168.101.0/24, Calgary 192.168.102.0/24 and - so on. FreeS/WAN can happily handle this. With, for example<VAR> - leftsubnet=192.168.101.0/24</VAR> and<VAR> rightsubnet=192.168.102.0/24</VAR> - in a connection description, any machine in Calgary can talk to any - machine in Vancouver. If you want to be more restrictive and use - something like<VAR> leftsubnet=192.168.101.128/25</VAR> and<VAR> - rightsubnet=192.168.102.240/28</VAR> so only certain machines on each - end have access to the tunnel, that's fine too.</P> -<P>You could also<STRONG> split the subnet</STRONG> into smaller ones, - for example using<VAR> 192.168.1.0/25</VAR> in Vancouver and<VAR> - rightsubnet=192.168.0.128/25</VAR> in Calgary.</P> -<P>Alternately, you can just<STRONG> give up routing</STRONG> directly - to machines on the subnets. Omit the<VAR> leftsubnet</VAR> and<VAR> - rightsubnet</VAR> parameters from your connection descriptions. Your - IPsec tunnels will then run between the public interfaces of the two - firewalls. Packets will be masqueraded both before they are put into - tunnels and after they emerge. Your Vancouver client machines will see - only one Calgary machine, the firewall.</P> -<H3><A name="road.masq">Can I assign a road warrior an address on my net - (a virtual identity)?</A></H3> -<P>Often it would be convenient to be able to give a Road Warrior an IP - address which appears to be on the local network. Some IPsec - implementations have support for this, sometimes calling the feature - "virtual identity".</P> -<P>Currently (Sept 2002) FreeS/WAN does not support this, and we have no - definite plans to add it. The difficulty is that is not yet a standard - mechanism for it. There is an Internet Draft for a method of doing it - using<A href="#DHCP"> DHCP</A> which looks promising. FreeS/WAN may - support that in a future release.</P> -<P>In the meanwhile, you can do it yourself using the Linux iproute2(8) - facilities. Details are in<A href="http://www.av8n.com/vpn/iproute2.htm"> - this paper</A>.</P> -<P>Another method has also been discussed on the mailing list.:</P> -<UL> -<LI>You can use a variant of the<A href="#extruded.config"> extruded - subnet</A> procedure.</LI> -<LI>You have to avoid having the road warrior's assigned address within - the range you actually use at home base. See previous question.</LI> -<LI>On the other hand, you want the roadwarrior's address to be within - the range that<EM> seems</EM> to be on your network.</LI> -</UL> -<P>For example, you might have:</P> -<DL> -<DT>leftsubnet=a.b.c.0/25</DT> -<DD>head office network</DD> -<DT>rightsubnet=a.b.c.129/32</DT> -<DD>extruded to a road warrior. Note that this is not in a.b.c.0/25</DD> -<DT>a.b.c.0/24</DT> -<DD>whole network, including both the above</DD> -</DL> -<P>You then set up routing so that the office machines use the IPsec - gateway as their route to a.b.c.128/25. The leftsubnet parameter tells - the road warriors to use tunnels to reach a.b.c.0/25, so you should - have two-way communication. Depending or your network and applications, - there may be some additional work to do on DNS or Windows configuration</P> -<H3><A name="road.many">Can I support many road warriors with one - gateway?</A></H3> -<P>Yes. This is easily done, using</P> -<DL> -<DT>either RSA authentication</DT> -<DD>standard in the FreeS/WAN distribution</DD> -<DT>or X.509 certificates</DT> -<DD>requires<A href="#PKIcert"> Super FreeS/WAN or a patch</A>.</DD> -</DL> -<P>In either case, each Road Warrior must have a different key or - certificate.</P> -<P>It is also possible using pre-shared key authentication, though we - don't recommend this; see the<A href="#road.PSK"> next question</A> for - details.</P> -<P>If you expect to have more than a few dozen Road Warriors connecting - simultaneously, you may need a fairly powerful gateway machine. See our - document on<A href="performance.html"> FreeS/WAN performance</A>.</P> -<H3><A name="road.PSK">Can I have many road warriors using shared secret - authentication?</A></H3> -<P><STRONG>Yes, but avoid it if possible</STRONG>.</P> -<P>You can have multiple Road Warriors using shared secret - authentication<STRONG> only if they all use the same secret</STRONG>. - You must also set:</P> -<P></P> -<PRE> uniqueids=no </PRE> -<P>in the connection definition.</P> -<P>Why it's less secure:</P> -<UL> -<LI>If you have many users, it becomes almost certain the secret will - leak</LI> -<LI>The secret becomes quite valuable to an attacker</LI> -<LI>All users authenticate the same way, so the gateway cannot tell them - apart for logging or access control purposes</LI> -<LI>Changing the secret is difficult. You have to securely notify all - users.</LI> -<LI>If you find out the secret has been compromised, you can change it, - but then what? None of your users can connect without the new secret. - How will you notify them all, quickly and securely, without using the - VPN?</LI> -</UL> -<P>This is a designed-in limitation of the<A href="#IKE"> IKE</A> key - negotiation protocol, not a problem with our implementation.</P> -<P><STRONG>We very strongly recommend that you avoid using shared secret - authentication for multiple Road Warriors.</STRONG> Use RSA - authentication instead.</P> -<P>The longer story: When using shared secrets, the protocol requires - that the responding gateway be able to determine which secret to use at - a time when all it knows about the initiator is an IP address. This - works fine if you know the initiator's address in advance and can use - it to look up the appropiriate secret. However, it fails for Road - Warriors since the gateway cannot know their IP addresses in advance.</P> -<P>With RSA signatures (or certificates) the protocol is slightly - different. The initiator provides an identifier early in the exchange - and the responder can use that identifier to look up the correct key or - certificate. See<A href="#road.many"> above</A>.</P> -<H3><A name="QoS">Can I use Quality of Service routing with FreeS/WAN?</A> -</H3> -<P>From project technical lead Henry Spencer:</P> -<PRE>> Do QoS add to FreeS/WAN? -> For example integrating DiffServ and FreeS/WAN? - -With a current version of FreeS/WAN, you will have to add hidetos=no to -the config-setup section of your configuration file. By default, the TOS -field of tunnel packets is zeroed; with hidetos=no, it is copied from the -packet inside. (This is a modest security hole, which is why it is no -longer the default.) - -DiffServ does not interact well with tunneling in general. Ways of -improving this are being studied.</PRE> -<P>Copying the<A href="#TOS"> TOS</A> (type of service) information from - the encapsulated packet to the outer header reveals the TOS information - to an eavesdropper. This does not tell him much, but it might be of use - in<A href="#traffic"> traffic analysis</A>. Since we do not have to - give it to him, our default is not to.</P> -<P>Even with the TOS hidden, you can still:</P> -<UL> -<LI>apply QOS rules to the tunneled (ESP) packets; for example, by - giving ESP packets a certain priority.</LI> -<LI>apply QOS rules to the packets as they enter or exit the tunnel via - an IPsec virtual interface (eg.<VAR> ipsec0</VAR>).</LI> -</UL> -<P>See<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5)</A> for more - on the<VAR> hidetos=</VAR> parameter.</P> -<H3><A name="deadtunnel">Can I recognise dead tunnels and shut them - down?</A></H3> -<P>There is no general mechanism to do this is in the IPsec protocols.</P> -<P>From time to time, there is discussion on the IETF Working Group<A href="#ietf"> - mailing list</A> of adding a "keep-alive" mechanism (which some say - should be called "make-dead"), but it is a fairly complex problem and - no consensus has been reached on whether or how it should be done.</P> -<P>The protocol does have optional<A href="#ignore"> delete-SA</A> - messages which one side can send when it closes a connection in hopes - this will cause the other side to do the same. FreeS/WAN does not - currently support these. In any case, they would not solve the problem - since:</P> -<UL> -<LI>a gateway that crashes or hangs would not send the messages</LI> -<LI>the sender is not required to send them</LI> -<LI>they are not authenticated, so any receiver that trusts them leaves - itself open to a<A href="#DOS"> denial of service</A> attack</LI> -<LI>the receiver is not required to do anything about them</LI> -<LI>the receiver cannot acknowledge them; the protocol provides no - mechanism for that</LI> -<LI>since they are not acknowledged, the sender cannot rely on them</LI> -</UL> -<P>However, connections do have limited lifetimes and you can control - how many attempts your gateway makes to rekey before giving up. For - example, you can set:</P> -<PRE>conn default - keyingtries=3 - keylife=30m</PRE> -<P>With these settings old connections will be cleaned up. Within 30 - minutes of the other end dying, rekeying will be attempted. If it - succeeds, the new connection replaces the old one. If it fails, no new - connection is created. Either way, the old connection is taken down - when its lifetime expires.</P> -<P>Here is a mailing list message on the topic from FreeS/WAN tech - support person Claudia Schmeing:</P> -<PRE>You ask how to determine whether a tunnel is redundant: - -> Can anybody explain the best way to determine this. Esp when a RW has -> disconnected? I thought 'ipsec auto --status' might be one way. - -If a tunnel goes down from one end, Linux FreeS/WAN on the -other end has no way of knowing this until it attempts to rekey. -Once it tries to rekey and fails, it will 'know' that the tunnel is -down. - -Because it doesn't have a way of knowing the state until this point, -it will also not be able to tell you the state via ipsec auto --status. - -> However, comparing output from a working tunnel with that of one that -> was closed -> did not show clearly show tunnel status. - -If your tunnel is down but not 'unrouted' (see man ipsec_auto), you -should not be able to ping the opposite side of the tunnel. You can -use this as an indicator of tunnel status. - -On a related note, you may be interested to know that as of 1.7, -redundant tunnels caused by RW disconnections are likely to be -less of a pain. From doc/CHANGES: - - There is a new configuration parameter, uniqueids, to control a new Pluto - option: when a new connection is negotiated with the same ID as an old - one, the old one is deleted immediately. This should help eliminate - dangling Road Warrior connections when the same Road Warrior reconnects. - It thus requires that IDs not be shared by hosts (a previously legal but - probably useless capability). NOTE WELL: the sample ipsec.conf now has - uniqueids=yes in its config-setup section. - - -Cheers, - -Claudia</PRE> -<H3><A name="demanddial">Can I build IPsec tunnels over a demand-dialed - link?</A></H3> -<P>This is possible, but not easy. FreeS/WAN technical lead Henry - Spencer wrote:</P> -<PRE>> 5. If the ISDN link goes down in between and is reestablished, the SAs -> are still up but the eroute are deleted and the IPsec interface shows -> garbage (with ifconfig) -> 6. Only restarting IPsec will bring the VPN back online. - -This one is awkward to solve. If the real interface that the IPsec -interface is mounted on goes down, it takes most of the IPsec machinery -down with it, and a restart is the only good way to recover. - -The only really clean fix, right now, is to split the machines in two: - -1. A minimal machine serves as the network router, and only it is aware -that the link goes up and down. - -2. The IPsec is done on a separate gateway machine, which thinks it has -a permanent network connection, via the router. - -This is clumsy but it does work. Trying to do both functions within a -single machine is tricky. There is a software package (diald) which will -give the illusion of a permanent connection for demand-dialed modem -connections; I don't know whether it's usable for ISDN, or whether it can -be made to cooperate properly with FreeS/WAN. - -Doing a restart each time the interface comes up *does* work, although it -is a bit painful. I did that with PPP when I was running on a modem link; -it wasn't hard to arrange the PPP scripts to bring IPsec up and down at -the right times. (I'd meant to investigate diald but never found time.) - -In principle you don't need to do a complete restart on reconnect, but you -do have to rebuild some things, and we have no nice clean way of doing -only the necessary parts.</PRE> -<P>In the same thread, one user commented:</P> -<PRE>Subject: Re: linux-ipsec: IPsec and Dial Up Connections - Date: Wed, 22 Nov 2000 - From: Andy Bradford <andyb@calderasystems.com> - -On Wed, 22 Nov 2000 19:47:11 +0100, Philip Reetz wrote: - -> Are there any ideas what might be the cause of the problem and any way -> to work around it. -> Any help is highly appreciated. - -On my laptop, when using ppp there is a ip-up script in /etc/ppp that -will be executed each time that the ppp interface is brought up. -Likewise there is an ip-down script that is called when it is taken -down. You might consider custimzing those to stop and start FreeS/WAN -with each connection. I believe that ISDN uses the same files, though -I could be wrong---there should be something similar though.</PRE> -<H3><A name="GRE">Can I build GRE, L2TP or PPTP tunnels over IPsec?</A></H3> -<P>Yes. Normally this is not necessary, but it is useful in a few - special cases. For example, if you must route non-IP packets such as - IPX, you will need to use a tunneling protocol that can route these - packets. IPsec can be layered around it for extra security. Another - example: you can provide failover protection for high availability (HA) - environments by combining IPsec with other tools. Ken Bantoft describes - one such setup in<A HREF="http://www.freeswan.ca/docs/HA"> Using - FreeS/WAN with Linux-HA, GRE, OSPF and BGP for enterprise grade VPN - solutions</A>.</P> -<P>GRE over IPsec is covered as part of<A HREF="http://www.freeswan.ca/docs/HA"> - that document</A>.<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/07/msg00209.html"> - Here are links</A> to other GRE resources. Jacco de Leuw has created<A HREF="http://www.jacco2.dds.nl/networking/"> - this page on L2TP over IPsec</A> with instructions for FreeS/WAN and - several other brands of IPsec software.</P> -<P>Please let us know of other useful links via the<A HREF="mail.html"> - mailing lists</A>.</P> -<H3><A name="NetBIOS">... use Network Neighborhood (Samba, NetBIOS) over - IPsec?</A></H3> -<P>Your local PC needs to know how to translate NetBIOS names to IP - addresses. It may do this either via a local LMHOSTS file, or using a - local or remote WINS server. The WINS server is preferable since it - provides a centralized source of the information to the entire network. - To use a WINS server over the<A HREF="#VPN"> VPN</A> (or any IP-based - network), you must enable "NetBIOS over TCP".</P> -<P><A HREF="http://www.samba.org">Samba</A> can emulate a WINS server on - Linux.</P> -<P> See also several discussions in our<A HREF="http://lists.freeswan.org/pipermail/users/2002-September/thread.html"> - September 2002 Users archives</A></P> -<H2><A name="setup.faq">Life's little mysteries</A></H2> -<P>FreeS/WAN is a fairly complex product. (Neither the networks it runs - on nor the protocols it uses are simple, so it could hardly be - otherwise.) It therefore sometimes exhibits behaviour which can be - somewhat confusing, or has problems which are not easy to diagnose. - This section tries to explain those problems.</P> -<P>Setup and configuration of FreeS/WAN are covered in other - documentation sections:</P> -<UL> -<LI><A href="quickstart.html">basic setup and configuration</A></LI> -<LI><A href="adv_config.html">advanced configuration</A></LI> -<LI><A href="trouble.html">Troubleshooting</A></LI> -</UL> -<P>However, we also list some of the commonest problems here.</P> -<H3><A name="cantping">I cannot ping ....</A></H3> -<P>This question is dealt with in the advanced configuration section - under the heading<A href="#multitunnel"> multiple tunnels</A>.</P> -<P>The standard subnet-to-subnet tunnel protects traffic<STRONG> only - between the subnets</STRONG>. To test it, you must use pings that go - from one subnet to the other.</P> -<P>For example, suppose you have:</P> -<PRE> subnet a.b.c.0/24 - | - eth1 = a.b.c.1 - gate1 - eth0 = 192.0.2.8 - | - - ~ internet ~ - - | - eth0 = 192.0.2.11 - gate2 - eth1 = x.y.z.1 - | - subnet x.y.z.0/24</PRE> -<P>and the connection description:</P> -<PRE>conn abc-xyz - left=192.0.2.8 - leftsubnet=a.b.c.0/24 - right=192.0.2.11 - rightsubnet=x.y.z.0/24</PRE> -<P>You can test this connection description only by sending a ping that - will actually go through the tunnel. Assuming you have machines at - addresses a.b.c.2 and x.y.z.2, pings you might consider trying are:</P> -<DL> -<DT>ping from x.y.z.2 to a.b.c.2 or vice versa</DT> -<DD>Succeeds if tunnel is working. This is the<STRONG> only valid test - of the tunnel</STRONG>.</DD> -<DT>ping from gate2 to a.b.c.2 or vice versa</DT> -<DD><STRONG>Does not use tunnel</STRONG>. gate2 is not on protected - subnet.</DD> -<DT>ping from gate1 to x.y.z.2 or vice versa</DT> -<DD><STRONG>Does not use tunnel</STRONG>. gate1 is not on protected - subnet.</DD> -<DT>ping from gate1 to gate2 or vice versa</DT> -<DD><STRONG>Does not use tunnel</STRONG>. Neither gate is on a protected - subnet.</DD> -</DL> -<P>Only the first of these is a useful test of this tunnel. The others - do not use the tunnel. Depending on other details of your setup and - routing, they:</P> -<UL> -<LI>either fail, telling you nothing about the tunnel</LI> -<LI>or succeed, telling you nothing about the tunnel since these packets - use some other route</LI> -</UL> -<P>In some cases, you may be able to get around this. For the example - network above, you could use:</P> -<PRE> ping -I a.b.c.1 x.y.z.1</PRE> -<P>Both the adresses given are within protected subnets, so this should - go through the tunnel.</P> -<P>If required, you can build additional tunnels so that all the - machines involved can talk to all the others. See<A href="#multitunnel"> - multiple tunnels</A> in the advanced configuration document for - details.</P> -<H3><A name="forever">It takes forever to ...</A></H3> -<P>Users fairly often report various problems involving long delays, - sometimes on tunnel setup and sometimes on operations done through the - tunnel, occasionally on simple things like ping or more often on more - complex operations like doing NFS or Samba through the tunnel.</P> -<P>Almost always, these turn out to involve failure of a DNS lookup. The - timeouts waiting for DNS are typically set long so that you won't time - out when a query involves multiple lookups or long paths. Genuine - failures therefore produce long delays before they are detected.</P> -<P>A mailing list message from project technical lead Henry Spencer:</P> -<PRE>> ... when i run /etc/rc.d/init.d/ipsec start, i get: -> ipsec_setup: Starting FreeS/WAN IPsec 1.5... -> and it just sits there, doesn't give back my bash prompt. - -Almost certainly, the problem is that you're using DNS names in your -ipsec.conf, but DNS lookups are not working for some reason. You will -get your prompt back... eventually. But the DNS timeouts are long. -Doing something about this is on our list, but it is not easy.</PRE> -<P>In the meanwhile, we recommend that connection descriptions in<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A> use numeric IP addresses rather than names which will - require a DNS lookup.</P> -<P>Names that do not require a lookup are fine. For example:</P> -<UL> -<LI>a road warrior might use the identity<VAR> - rightid=@lancelot.example.org</VAR></LI> -<LI>the gateway might use<VAR> leftid=@camelot.example.org</VAR></LI> -</UL> -<P>These are fine. The @ sign prevents any DNS lookup. However, do not - attempt to give the gateway address as<VAR> left=camelot.example.org</VAR> -. That requires a lookup.</P> -<P>A post from one user after solving a problem with long delays:</P> -<PRE>Subject: Final Answer to Delay!!! - Date: Mon, 19 Feb 2001 - From: "Felippe Solutions" <felippe@solutionstecnologia.com.br> - -Sorry people, but seems like the Delay problem had nothing to do with -freeswan. - -The problem was DNS as some people sad from the beginning, but not the way -they thought it was happening. Samba, ssh, telnet and other apps try to -reverse lookup addresses when you use IP numbers (Stupid that ahh). - -I could ping very fast because I always ping with "-n" option, but I don't -know the option on the other apps to stop reverse addressing so I don't use -it.</PRE> -<P>This post is fairly typical. These problems are often tricky and - frustrating to diagnose, and most turn out to be DNS-related.</P> -<P>One suggestion for diagnosis: test with both names and addresses if - possible. For example, try all of:</P> -<UL> -<LI>ping<VAR> address</VAR></LI> -<LI>ping -n<VAR> address</VAR></LI> -<LI>ping<VAR> name</VAR></LI> -</UL> -<P>If these behave differently, the problem must be DNS-related since - the three commands do exactly the same thing except for DNS lookups.</P> -<H3><A name="route">I send packets to the tunnel with route(8) but they - vanish</A></H3> -<P>IPsec connections are designed to carry only packets travelling - between pre-defined connection endpoints. As project technical lead - Henry Spencer put it:</P> -<BLOCKQUOTE> IPsec tunnels are not just virtual wires; they are virtual - wires with built-in access controls. Negotiation of an IPsec tunnel - includes negotiation of access rights for it, which don't include - packets to/from other IP addresses. (The protocols themselves are quite - inflexible about this, so there are limits to what we can do about it.)</BLOCKQUOTE> -<P>For fairly obvious security reasons, and to comply with the IPsec - RFCs,<A href="#KLIPS"> KLIPS</A> drops any packets it receives that are - not allowed on the tunnels currently defined. So if you send it packets - with<VAR> route(8)</VAR>, and suitable tunnels are not defined, the - packets vanish. Whether this is reported in the logs depends on the - setting of<VAR> klipsdebug</VAR> in your<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A> file.</P> -<P>To rescue vanishing packets, you must ensure that suitable tunnels - for them exist, by editing the connection descriptions in<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A>. For example, supposing you have a simple setup:</P> -<PRE> leftsubnet -- leftgateway === internet === roadwarrior</PRE> -<P>If you want to give the roadwarrior access to some resource that is - located behind the left gateway but is not in the currently defined - left subnet, then the usual procedure is to define an additional tunnel - for those packets by creating a new connection description.</P> -<P>In some cases, it may be easier to alter an existing connection - description, enlarging the definition of<VAR> leftsubnet</VAR>. For - example, instead of two connection descriptions with 192.168.8.0/24 and - 192.168.9.0/24 as their<VAR> leftsubnet</VAR> parameters, you can use a - single description with 192.168.8.0/23.</P> -<P>If you have multiple endpoints on each side, you need to ensure that - there is a route for each pair of endpoints. See this<A href="#multitunnel"> - example</A>.</P> -<H3><A name="down_route">When a tunnel goes down, packets vanish</A></H3> -<P>This is a special case of the vanishing packet problem described in - the previous question. Whenever KLIPS sees packets for which it does - not have a tunnel, it drops them.</P> -<P>When a tunnel goes away, either because negotiations with the other - gateway failed or because you gave an<VAR> ipsec auto --down</VAR> - command, the route to its other end is left pointing into KLIPS, and - KLIPS will drop packets it has no tunnel for.</P> -<P>This is a documented design decision, not a bug. FreeS/WAN must not - automatically adjust things to send packets via another route. The - other route might be insecure.</P> -<P>Of course, re-routing may be necessary in many cases. In those cases, - you have to do it manually or via scripts. We provide the<VAR> ipsec - auto --unroute</VAR> command for these cases.</P> -<P>From<A href="manpage.d/ipsec_auto.8.html"> ipsec_auto(8)</A>:</P> -<BLOCKQUOTE> Normally, pluto establishes a route to the destination - specified for a connection as part of the --up operation. However, the - route and only the route can be established with the --route operation. - Until and unless an actual connection is established, this discards any - packets sent there, which may be preferable to having them sent - elsewhere based on a more general route (e.g., a default route).</BLOCKQUOTE><BLOCKQUOTE> - Normally, pluto's route to a destination remains in place when a --down - operation is used to take the connection down (or if connection setup, - or later automatic rekeying, fails). This permits establishing a new - connection (perhaps using a different specification; the route is - altered as necessary) without having a ``window'' in which packets - might go elsewhere based on a more general route. Such a route can be - removed using the --unroute operation (and is implicitly removed by - --delete).</BLOCKQUOTE> -<P>See also this mailing list<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/11/msg00523.html"> - message</A>.</P> -<H3><A name="firewall_ate">The firewall ate my packets!</A></H3> -<P>If firewalls filter out:</P> -<UL> -<LI>either the UDP port 500 packets used in IKE negotiations</LI> -<LI>or the ESP and AH (protocols 50 and 51) packets used to implement - the IPsec tunnel</LI> -</UL> -<P>then IPsec cannot work. The first thing to check if packets seem to - be vanishing is the firewall rules on the two gateway machines and any - other machines along the path that you have access to.</P> -<P>For details, see our document on<A href="firewall.html"> firewalls</A> -.</P> -<P>Some advice from technical lead Henry Spencer on diagnosing such - problems:</P> -<PRE>> > Packets vanishing between the hardware interface and the ipsecN interface -> > is usually the result of firewalls not being configured to let them in... -> -> Thanks for the suggestion. If only it were that simple! My ipchains startup -> script does take care of that, but just in case I manually inserted rules -> accepting everything from london on dublin. No difference. - -The other thing to check is whether the "RX packets dropped" count on the -ipsecN interface (run "ifconfig ipsecN", for N=1 or whatever, to see the -counts) is rising. If so, then there's some sort of configuration mismatch -between the two ends, and IPsec itself is rejecting them. If none of the -ipsecN counts is rising, then the packets are never reaching the IPsec -machinery, and the problem is almost certainly in firewalls etc.</PRE> -<H3><A name="dropconn">Dropped connections</A></H3> -<P>Networks being what they are, IPsec connections can be broken for any - number of reasons, ranging from hardware failures to various software - problems such as the path MTU problems discussed<A href="#pmtu.broken"> - elsewhere in the FAQ</A>. Fortunately, various diagnostic tools exist - that help you sort out many of the possible problems.</P> -<P>There is one situation, however, where FreeS/WAN (using default - settings) may destroy a connection for no readily apparent reason. This - occurs when things are<STRONG> misconfigured</STRONG> so that<STRONG> - two tunnels</STRONG> from the same gateway expect<STRONG> the same - subnet on the far end</STRONG>.</P> -<P>In this situation, the first tunnel comes up fine and works until the - second is established. At that point, because of the way we track - connections internally, the first tunnel ceases to exist as far as this - gateway is concerned. Of course the far end does not know that, and a - storm of error messages appears on both systems as it tries to use the - tunnel.</P> -<P>If the far end gives up, goes back to square one and negotiates a new - tunnel, then that wipes out the second tunnel and ...</P> -<P>The solution is simple.<STRONG> Do not build multiple conn - descriptions with the same remote subnet</STRONG>.</P> -<P>This is actually intended to be a feature, rather than a bug. - Consider the situation where a single remote system goes down, then - comes back up and reconnects to the gateway. It is useful to have the - gateway tear down the old tunnel and recover resources when the - reconnection is made. It recognises that situation by checking the - remote subnet for each tunnel it builds and discarding duplicates. This - works fine as long as you don't configure multiple tunnels with the - same remote subnet.</P> -<P>If this behaviour is inconvenient for you, you can disable it by - setting<VAR> uniqueids=no</VAR> in<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A>.</P> -<H3><A name="defaultroutegone">Disappearing %defaultroute</A></H3> -<P>When an underlying connection (eg. ppp) goes down, FreeS/WAN will not - recover properly without a little help. Here are the symptoms that - FreeS/WAN user Michael Carmody noticed:</P> -<PRE> -> After about 24 hours the freeswan connection takes over the default route. -> -> i.e instead of deafult gateway pointing to the router via eth0, it becomes a -> pointer to the router via ipsec0. - -> All internet access is then lost as all replies (and not just the link I -> wanted) are routed out ipsec0 and the router doesn't respond to the ipsec -> traffic. -</PRE> -<P>If you're using a FreeS/WAN 2.x/KLIPS system, simply re-attach the - IPsec virtual interface with<EM> ipsec tnconfig</EM> command such as:</P> -<PRE> ipsec tnconfig --attach --virtual ipsec0 --physical ppp0</PRE> -<P>In your command, name the physical and virtual interfaces as they - appear paired on your system during regular uptime. For a system with - several physical/virtual interface pairs on flaky links, you'll need - more than one such command. If you're using FreeS/WAN 1.x, you must - restart FreeS/WAN, which is more time consuming.</P> -<P><A href="http://lists.freeswan.org/pipermail/design/2002-July/003070.html"> - Here</A> is a script which can help to automate the process of - FreeS/WAN restart at need. It could easily be adapted to use tnconfig - instead.</P> -<H3><A name="tcpdump.faq">TCPdump on the gateway shows strange things</A> -</H3> - As another user pointed out, keeping the connect -<P>Attempting to look at IPsec packets by running monitoring tools on - the IPsec gateway machine can produce silly results. That machine is - mangling the packets for IPsec, and possibly for firewall or NAT - purposes as well. If the internals of the machine's IP stack are not - what the monitoring tool expects, then the tool can misinterpret them - and produce nonsense output.</P> -<P>See our<A href="#tcpdump.test"> testing</A> document for more detail.</P> -<H3><A name="no_trace">Traceroute does not show anything between the - gateways</A></H3> -<P>As far as traceroute can see, the two gateways are one hop apart; the - data packet goes directly from one to the other through the tunnel. Of - course the outer packets that implement the tunnel pass through - whatever lies between the gateways, but those packets are built and - dismantled by the gateways. Traceroute does not see them and cannot - report anything about their path.</P> -<P>Here is a mailing list message with more detail.</P> -<PRE>Date: Mon, 14 May 2001 -To: linux-ipsec@freeswan.org -From: "John S. Denker" <jsd@research.att.com< -Subject: Re: traceroute: one virtual hop - -At 02:20 PM 5/14/01 -0400, Claudia Schmeing wrote: -> ->> > A bonus question: traceroute in subnet to subnet enviroment looks like: ->> > ->> > traceroute to andris.dmz (172.20.24.10), 30 hops max, 38 byte packets ->> > 1 drama (172.20.1.1) 0.716 ms 0.942 ms 0.434 ms ->> > 2 * * * ->> > 3 andris.dmz (172.20.24.10) 73.576 ms 78.858 ms 79.434 ms ->> > ->> > Why aren't there the other hosts which take part in the delivery during -> * * * ? -> ->If there is an ipsec tunnel between GateA and Gate B, this tunnel forms a ->'virtual wire'. When it is tunneled, the original packet becomes an inner ->packet, and new ESP and/or AH headers are added to create an outer packet ->around it. You can see an example of how this is done for AH at ->doc/ipsec.html#AH . For ESP it is similar. -> ->Think about the packet's path from the inner packet's perspective. ->It leaves the subnet, goes into the tunnel, and re-emerges in the second ->subnet. This perspective is also the only one available to the ->'traceroute' command when the IPSec tunnel is up. - -Claudia got this exactly right. Let me just expand on a couple of points: - -*) GateB is exactly one (virtual) hop away from GateA. This is how it -would be if there were a physically private wire from A to B. The -virtually private connection should work the same, and it does. - -*) While the information is in transit from GateA to GateB, the hop count -of the outer header (the "envelope") is being decremented. The hop count -of the inner header (the "contents" of the envelope) is not decremented and -should not be decremented. The hop count of the outer header is not -derived from and should not be derived from the hop count of the inner header. - -Indeed, even if the packets did time out in transit along the tunnel, there -would be no way for traceroute to find out what happened. Just as -information cannot leak _out_ of the tunnel to the outside, information -cannot leak _into_ the tunnel from outside, and this includes ICMP messages -from routers along the path. - -There are some cases where one might wish for information about what is -happening at the IP layer (below the tunnel layer) -- but the protocol -makes no provision for this. This raises all sorts of conceptual issues. -AFAIK nobody has ever cared enough to really figure out what _should_ -happen, let alone implement it and standardize it. - -*) I consider the "* * *" to be a slight bug. One might wish for it to be -replaced by "GateB GateB GateB". It has to do with treating host-to-subnet -traffic different from subnet-to-subnet traffic (and other gory details). -I fervently hope KLIPS2 will make this problem go away. - -*) If you want to ask questions about the link from GateA to GateB at the -IP level (below the tunnel level), you have to ssh to GateA and launch a -traceroute from there.</PRE> -<H2><A name="man4debug">Testing in stages</A></H2> -<P>It is often useful in debugging to test things one at a time:</P> -<UL> -<LI>disable IPsec entirely, for example by turning it off with - chkconfig(8), and make sure routing works</LI> -<LI>Once that works, try a manually keyed connection. This does not - require key negotiation between Pluto and the key daemon on the other - end.</LI> -<LI>Once that works, try automatically keyed connections</LI> -<LI>Once IPsec works, add packet compression</LI> -<LI>Once everything seems to work, try stress tests with large - transfers, many connections, frequent re-keying, ...</LI> -</UL> -<P>FreeS/WAN releases are tested for all of these, so you can be - reasonably certain they<EM> can</EM> do them all. Of course, that does - not mean they<EM> will</EM> on the first try, especially if you have - some unusual configuration.</P> -<P>The rest of this section gives information on diagnosing the problem - when each of the above steps fails.</P> -<H3><A name="nomanual">Manually keyed connections don't work</A></H3> -<P>Suspect one of:</P> -<UL> -<LI>mis-configuration of IPsec system in the /etc/ipsec.conf file -<BR> common errors are incorrect interface or next hop information</LI> -<LI>mis-configuration of manual connection in the /etc/ipsec.conf file</LI> -<LI>routing problems causing IPsec packets to be lost</LI> -<LI>bugs in KLIPS</LI> -<LI>mismatch between the transforms we support and those another IPsec - implementation offers.</LI> -</UL> -<H3><A name="spi_error">One manual connection works, but second one - fails</A></H3> -<P>This is a fairly common problem when attempting to configure multiple - manually keyed connections from a single gateway.</P> -<P>Each connection must be identified by a unique<A href="#SPI"> SPI</A> - value. For automatic connections, these values are assigned - automatically. For manual connections, you must set them with<VAR> spi=</VAR> - statements in<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5)</A>.</P> -<P>Each manual connection must have a unique SPI value in the range - 0x100 to 0x999. Two or more with the same value will fail. For details, - see our doc section<A href="#prodman"> Using manual keying in - production</A> and the man page<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A>.</P> -<H3><A name="man_no_auto">Manual connections work, but automatic keying - doesn't</A></H3> -<P>The most common reason for this behaviour is a firewall dropping the - UDP port 500 packets used in key negotiation.</P> -<P>Other possibilities:</P> -<UL> -<LI>mis-configuration of auto connection in the /etc/ipsec.conf file. -<P>One common configuration error is forgetting that you need<VAR> - auto=add</VAR> to load the connection description on the receiving end - so it recognises the connection when the other end asks for it.</P> -</LI> -<LI>error in shared secret in /etc/ipsec.secrets</LI> -<LI>one gateway lacks a route to the other so Pluto's UDP packets are - lost</LI> -<LI>bugs in Pluto</LI> -<LI>incompatibilities between Pluto's<A href="#IKE"> IKE</A> - implementation and the IKE at the other end of the tunnel. -<P>Some possibile problems are discussed in out<A href="interop.html#interop.problem"> - interoperation</A> document.</P> -</LI> -</UL> -<H3><A name="nocomp">IPsec works, but connections using compression fail</A> -</H3> -<P>When we first added compression, we saw some problems:</P> -<UL> -<LI>compatibility issues with other implementations. We followed the - RFCs and omitted some extra material that many compression libraries - add by default. Some other implementations left the extras in</LI> -<LI>bugs in assembler compression routines on non-Intel CPUs. The - workaround is to use C code instead of possibly problematic assembler.</LI> -</UL> -<P>We have not seen either problem in some time (at least six months as - I write in March 2002), but if you have some unusual configuration then - you may see them.</P> -<H3><A name="pmtu.broken">Small packets work, but large transfers fail</A> -</H3> -<P>If tests with ping(1) and a small packet size succeed, but tests or - transfers with larger packet sizes fail, suspect problems with packet - fragmentation and perhaps<A href="#pathMTU"> path MTU discovery</A>.</P> -<P>Our<A href="#bigpacket"> troubleshooting document</A> covers these - problems. Information on the underlying mechanism is in our<A href="#MTU.trouble"> - background</A> document.</P> -<H3><A name="subsub">Subnet-to-subnet works, but tests from the gateways - don't</A></H3> -<P>This is described under<A href="#cantping"> I cannot ping...</A> - above.</P> -<H2><A name="compile.faq">Compilation problems</A></H2> -<H3><A name="gmp.h_missing">gmp.h: No such file or directory</A></H3> -<P>Pluto needs the GMP (<STRONG>G</STRONG>NU</P> -<P><STRONG>M</STRONG>ulti-<STRONG>P</STRONG>recision) library for the - large integer calculations it uses in<A href="#public"> public key</A> - cryptography. This error message indicates a failure to find the - library. You must install it before Pluto will compile.</P> -<P>The GMP library is included in most Linux distributions. Typically, - there are two RPMs, libgmp and libgmp-devel, You need to<EM> install - both</EM>, either from your distribution CDs or from your vendor's web - site.</P> -<P>On Debian, a mailing list message reports that the command to give is<VAR> - apt-get install gmp2</VAR>.</P> -<P>For more information and the latest version, see the<A href="http://www.swox.com/gmp/"> - GMP home page</A>.</P> -<H3><A name="noVM">... virtual memory exhausted</A></H3> -<P>We have had several reports of this message appearing, all on SPARC - Linux. Here is a mailing message on a solution:</P> -<PRE>> ipsec_sha1.c: In function `SHA1Transform': -> ipsec_sha1.c:95: virtual memory exhausted - -I'm seeing exactly the same problem on an Ultra with 256MB ram and 500 -MB swap. Except I am compiling version 1.5 and its Red Hat 6.2. - -I can get around this by using -O instead of -O2 for the optimization -level. So it is probably a bug in the optimizer on the sparc complier. -I'll try and chase this down on the sparc lists.</PRE> -<H2><A name="error">Interpreting error messages</A></H2> -<H3><A name="route-client">route-client (or host) exited with status 7</A> -</H3> -<P>Here is a discussion of this error from FreeS/WAN "listress" (mailing - list tech support person) Claudia Schmeing. The "FAQ on the network - unreachable error" which she refers to is the next question below.</P> -<PRE>> I reached the point where the two boxes (both on dial-up connections, but -> treated as static IPs by getting the IP and editing ipsec.conf after the -> connection is established) to the point where they exchange some info, but I -> get an error like "route-client command exited with status 7 \n internal -> error". -> Where can I find a description of this error? - -In general, if the FAQ doesn't cover it, you can search the mailing list -archives - I like to use -http://www.sandelman.ottawa.on.ca/linux-ipsec/ -but you can see doc/mail.html for different archive formats. - - -Your error comes from the _updown script, which performs some -routing and firewall functions to help Linux FreeS/WAN. More info -is available at doc/firewall.html and man ipsec.conf. Its routing -is integral to the health of Linux FreeS/WAN; it also provides facility -to insert custom firewall rules to be executed when you create or destroy -a connection. - -Yours is, of course, a routing error. You can be fairly sure the routing -machinery is saying "network is unreachable". There's a FAQ on the -"network is unreachable" error, but more information is available now; read on. - -If your _updown script is recent (for example if it shipped with -Linux FreeS/WAN 1.91), you will see another debugging line in your logs -that looks something like this: - -> output: /usr/local/lib/ipsec/_updown: `route add -net 128.174.253.83 -> netmask 255.255.255.255 dev ipsec0 gw 66.92.93.161' failed - -This is, of course, the system route command that exited with status 7, -(ie. failed). Man route for details. Seeing the command typed out yields -more information. If your _updown script is older, you may wish to update -it to show the command explicitly. - -Three parameters fed to the route command: net, netmask and gw [gateway] -are derived from things you've put in ipsec.conf. - -Net and netmask are derived from the peer's IP and mask. In more detail: - -You may see a routing error when routing to a client (ie. subnet), or -to a host (IPSec gateway or freestanding host; a box that does IPSec for -itself). In _updown, the "route-client" section is responsible to set up -the route for IPSec'd (usually, read 'tunneled') packets headed to a -peer subnet. Similarly, route-host routes IPSec'd packets to a peer host -or IPSec gateway. - -When routing to a 'client', net and netmask are ipsec.conf's left- or -rightsubnet (whichever is not local). Similarly, when routing to a -'host' the net is left or right. Host netmask is always /32, indicating a -single machine. - -Gw is nexthop's value. Again, the value in question is left- or rightnexthop, -whichever is local. Where left/right or left-/rightnexthop has the special -value %defaultroute (described in man ipsec.conf), gw will automagically get -the value of the next hop on the default route. - -Q: "What's a nexthop and why do I need one?" - -A: 'nexthop' is a routing kluge; its value is the next hop away - from the machine that's doing IPSec, and toward your IPSec peer. - You need it to get the processed packets out of the local system and - onto the wire. While we often route other packets through the machine - that's now doing IPSec, and are done with it, this does not suffice here. - After packets are processed with IPSec, this machine needs to know where - they go next. Of course using the 'IPSec gateway' as their routing gateway - would cause an infinite loop! [To visualize this, see the packet flow - diagram at doc/firewall.html.] To avoid this, we route packets through - the next hop down their projected path. - -Now that you know the background, consider: -1. Did you test routing between the gateways in the absence of Linux - FreeS/WAN, as recommended? You need to ensure the two machines that - will be running Linux FreeS/WAN can route to one another before trying to - make a secure connection. -2. Is there anything obviously wrong with the sense of your route command? - -Normally, this problem is caused by an incorrect local nexthop parameter. -Check out the use of %defaultroute, described in man ipsec.conf. This is -a simple way to set nexthop for most people. To figure nexthop out by hand, -traceroute in-the-clear to your IPSec peer. Nexthop is the traceroute's -first hop after your IPSec gateway.</PRE> -<H3><A name="unreachable">SIOCADDRT:Network is unreachable</A></H3> -<P>This message is not from FreeS/WAN, but from the Linux IP stack - itself. That stack is seeing packets it has no route for, either - because your routing was broken before FreeS/WAN started or because - FreeS/WAN's changes broke it.</P> -<P>Here is a message from Claudia suggesting ways to diagnose and fix - such problems:</P> -<PRE>You write, -> I have correctly installed freeswan-1.8 on RH7.0 kernel 2.2.17, but when -> I setup a VPN connection with the other machine(RH5.2 Kernel 2.0.36 -> freeswan-1.0, it works well.) it told me that -> "SIOCADDRT:Network is unreachable"! But the network connection is no -> problem. - -Often this error is the result of a misconfiguration. - -Be sure that you can route successfully in the absence of Linux -FreeS/WAN. (You say this is no problem, so proceed to the next step.) - -Use a custom copy of the default updownscript. Do not change the route -commands, but add a diagnostic message revealing the exact text of the -route command. Is there a problem with the sense of the route command -that you can see? If so, then re-examine those ipsec.conf settings -that are being sent to the route command. - -You may wish to use the ipsec auto --route and --unroute commands to -troubleshoot the problem. See man ipsec_auto for details.</PRE> -<P>Since the above message was written, we have modified the updown - script to provide a better diagnostic for this problem. Check<VAR> - /var/log/messages</VAR>.</P> -<P>See also the FAQ question<A href="#route-client"> route-client (or - host) exited with status 7</A>.</P> -<H3><A name="modprobe">ipsec_setup: modprobe: Can't locate module ipsec</A> -</H3> -<H3><A name="noKLIPS">ipsec_setup: Fatal error, kernel appears to lack - KLIPS</A></H3> -<P>These messages indicate an installation failure. The kernel you are - running does not contain the<A href="#KLIPS"> KLIPS (kernel IPsec)</A> - code.</P> -<P>Note that the "modprobe: Can't locate module ipsec" message appears - even if you are not using modules. If there is no KLIPS in your kernel, - FreeS/WAN tries to load it as a module. If that fails, you get this - message.</P> -<P>Commands you can quickly try are:</P> -<DL> -<DT><VAR>uname -a</VAR></DT> -<DD>to get details, including compilation date and time, of the - currently running kernel</DD> -<DT><VAR>ls /</VAR></DT> -<DT><VAR>ls /boot</VAR></DT> -<DD>to ensure a new kernel is where it should be. If kernel compilation - puts it in<VAR> /</VAR> but<VAR> lilo</VAR> wants it in<VAR> /boot</VAR> -, then you should uncomment the<VAR> INSTALL_PATH=/boot</VAR> line in - the kernel<VAR> Makefile</VAR>.</DD> -<DT><VAR>more /etc/lilo.conf</VAR></DT> -<DD>to see that<VAR> lilo</VAR> has correct information</DD> -<DT><VAR>lilo</VAR></DT> -<DD>to ensure that information in<VAR> /etc/lilo.conf</VAR> has been - transferred to the boot sector</DD> -</DL> -<P>If those don't find the problem, you have to go back and check - through the<A href="install.html"> install</A> procedure to see what - was missed.</P> -<P>Here is one of Claudia's messages on the topic:</P> -<PRE>> I tried to install freeswan 1.8 on my mandrake 7.2 test box. ... - -> It does show version and some output for whack. - -Yes, because the Pluto (daemon) part of ipsec is installed correctly, but -as we see below the kernel portion is not. - -> However, I get the following from /var/log/messages: -> -> Mar 11 22:11:55 pavillion ipsec_setup: Starting FreeS/WAN IPsec 1.8... -> Mar 11 22:12:02 pavillion ipsec_setup: modprobe: Can't locate module ipsec -> Mar 11 22:12:02 pavillion ipsec_setup: Fatal error, kernel appears to lack -> KLIPS. - -This is your problem. You have not successfully installed a kernel with -IPSec machinery in it. - -Did you build Linux FreeS/WAN as a module? If so, you need to ensure that -your new module has been installed in the directory where your kernel -loader normally finds your modules. If not, you need to ensure -that the new IPSec-enabled kernel is being loaded correctly. - -See also doc/install.html, and INSTALL in the distro.</PRE> -<H3><A name="noDNS">ipsec_setup: ... failure to fetch key for ... from - DNS</A></H3> -<P>Quoting Henry:</P> -<PRE>Note that by default, FreeS/WAN is now set up to - (a) authenticate with RSA keys, and - (b) fetch the public key of the far end from DNS. -Explicit attention to ipsec.conf will be needed if you want -to do something different.</PRE> -<P>and Claudia, responding to the same user:</P> -<PRE>You write, - -> My current setup in ipsec.conf is leftrsasigkey=%dns I have -> commented this and authby=rsasig out. I am able to get ipsec running, -> but what I find is that the documentation only specifies for %dns are -> there any other values that can be placed in this variable other than -> %dns and the key? I am also assuming that this is where I would place -> my public key for the left and right side as well is this correct? - -Valid values for authby= are rsasig and secret, which entail authentication -by RSA signature or by shared secret, respectively. Because you have -commented authby=rsasig out, you are using the default value of authby=secret. - -When using RSA signatures, there are two ways to get the public key for the -IPSec peer: either copy it directly into *rsasigkey= in ipsec.conf, or -fetch it from dns. The magic value %dns for *rsasigkey parameters says to -try to fetch the peer's key from dns. - -For any parameters, you may find their significance and special values in -man ipsec.conf. If you are setting up keys or secrets, be sure also to -reference man ipsec.secrets.</PRE> -<H3><A name="dup_address">ipsec_setup: ... interfaces ... and ... share - address ...</A></H3> -<P>This is a fatal error. FreeS/WAN cannot cope with two or more - interfaces using the same IP address. You must re-configure to avoid - this.</P> -<P>A mailing list message on the topic from Pluto developer Hugh - Redelmeier:</P> -<PRE>| I'm trying to get freeswan working between two machine where one has a ppp -| interface. -| I've already suceeded with two machines with ethernet ports but the ppp -| interface is causing me problems. -| basically when I run ipsec start i get -| ipsec_setup: Starting FreeS/WAN IPsec 1.7... -| ipsec_setup: 003 IP interfaces ppp1 and ppp0 share address 192.168.0.10! -| ipsec_setup: 003 IP interfaces ppp1 and ppp2 share address 192.168.0.10! -| ipsec_setup: 003 IP interfaces ppp0 and ppp2 share address 192.168.0.10! -| ipsec_setup: 003 no public interfaces found -| -| followed by lots of cannot work out interface for connection messages -| -| now I can specify the interface in ipsec.conf to be ppp0 , but this does -| not affect the above behaviour. A quick look in server.c indicates that the -| interfaces value is not used but some sort of raw detect happens. -| -| I guess I could prevent the formation of the extra ppp interfaces or -| allocate them different ip but I'd rather not. if at all possible. Any -| suggestions please. - -Pluto won't touch an interface that shares an IP address with another. -This will eventually change, but it probably won't happen soon. - -For now, you will have to give the ppp1 and ppp2 different addresses.</PRE> -<H3><A name="kflags">ipsec_setup: Cannot adjust kernel flags</A></H3> -<P>A mailing list message form technical lead Henry Spencer:</P> -<PRE>> When FreeS/WAN IPsec 1.7 is starting on my 2.0.38 Linux kernel the following -> error message is generated: -> ipsec_setup: Cannot adjust kernel flags, no /proc/sys/net/ipsec directory! -> What is supposed to create this directory and how can I fix this problem? - -I think that directory is a 2.2ism, although I'm not certain (I don't have -a 2.0.xx system handy any more for testing). Without it, some of the -ipsec.conf config-setup flags won't work, but otherwise things should -function. </PRE> -<P>You also need to enable the<VAR> /proc</VAR> filesystem in your - kernel configuration for these operations to work.</P> -<H3><A name="message_num">Message numbers (MI3, QR1, et cetera) in Pluto - messages</A></H3> -<P>Pluto messages often indicate where Pluto is in the IKE protocols. - The letters indicate<STRONG> M</STRONG>ain mode or<STRONG> Q</STRONG> -uick mode and<STRONG> I</STRONG>nitiator or<STRONG> R</STRONG>esponder. - The numerals are message sequence numbers. For more detail, see our<A href="#sequence"> - IPsec section</A>.</P> -<H3><A name="conn_name">Connection names in Pluto error messages</A></H3> -<P>From Pluto programmer Hugh Redelmeier:</P> -<PRE>| Jan 17 16:21:10 remus Pluto[13631]: "jumble" #1: responding to Main Mode from Road Warrior 130.205.82.46 -| Jan 17 16:21:11 remus Pluto[13631]: "jumble" #1: no suitable connection for peer @banshee.wittsend.com -| -| The connection "jumble" has nothing to do with the incoming -| connection requests, which were meant for the connection "banshee". - -You are right. The message tells you which Connection Pluto is -currently using, which need not be the right one. It need not be the -right one now for the negotiation to eventually succeed! This is -described in ipsec_pluto(8) in the section "Road Warrior Support". - -There are two times when Pluto will consider switching Connections for -a state object. Both are in response to receiving ID payloads (one in -Phase 1 / Main Mode and one in Phase 2 / Quick Mode). The second is -not unique to Road Warriors. In fact, neither is the first any more -(two connections for the same pair of hosts could differ in Phase 1 ID -payload; probably nobody else has tried this).</PRE> -<H3><A name="cantorient">Pluto: ... can't orient connection</A></H3> -<P>Older versions of FreeS/WAN used this message. The same error now - gives the "we have no ipsecN ..." error described just below.</P> -<H3><A name="no.interface">... we have no ipsecN interface for either - end of this connection</A></H3> -<P>Your tunnel has no IP address which matches the IP address of any of - the available IPsec interfaces. Either you've misconfigured the - connection, or you need to define an appropriate IPsec interface - connection.<VAR> interfaces=%defaultroute</VAR> works in many cases.</P> -<P>A longer story: Pluto needs to know whether it is running on the - machine which the connection description calls<VAR> left</VAR> or on<VAR> - right</VAR>. It figures that out by:</P> -<UL> -<LI>looking at the interfaces given in<VAR> interfaces=</VAR> lines in - the<VAR> config setup</VAR> section</LI> -<LI>discovering the IP addresses for those interfaces</LI> -<LI>searching for a match between those addresses and the ones given in<VAR> - left=</VAR> or<VAR> right=</VAR> lines.</LI> -</UL> -<P>Normally a match is found. Then Pluto knows where it is and can set - up other things (for example, if it is<VAR> left</VAR>) using - parameters such as<VAR> leftsubnet</VAR> and<VAR> leftnexthop</VAR>, - and sending its outgoing packets to<VAR> right</VAR>.</P> -<P>If no match is found, it emits the above error message.</P> -<H3><A name="noconn">Pluto: ... no connection is known</A></H3> -<P>This error message occurs when a remote system attempts to negotiate - a connection and Pluto does not have a connection description that - matches what the remote system has requested. The most common cause is - a configuration error on one end or the other.</P> -<P>Parameters involved in this match are<VAR> left</VAR>,<VAR> right</VAR> -,<VAR> leftsubnet</VAR> and<VAR> rightsubnet</VAR>.</P> -<P><STRONG>The match must be exact</STRONG>. For example, if your left - subnet is a.b.c.0/24 then neither a single machine in that net nor a - smaller subnet such as a.b.c.64/26 will be considered a match.</P> -<P>The message can also occur when an appropriate description exists but - Pluto has not loaded it. Use an<VAR> auto=add</VAR> statement in the - connection description, or an<VAR> ipsec auto --add <conn_name></VAR> - command, to correct this.</P> -<P>An explanation from the Pluto developer:</P> -<PRE>| Jul 12 15:00:22 sohar58 Pluto[574]: "corp_road" #2: cannot respond to IPsec -| SA request because no connection is known for -| 216.112.83.112/32===216.112.83.112...216.67.25.118 - -This is the first message from the Pluto log showing a problem. It -means that PGPnet is trying to negotiate a set of SAs with this -topology: - -216.112.83.112/32===216.112.83.112...216.67.25.118 -^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^ ^^^^^^^^^^^^^ -client on our side our host PGPnet host, no client - -None of the conns you showed look like this. - -Use - ipsec auto --status -to see a snapshot of what connections are in pluto, what -negotiations are going on, and what SAs are established. - -The leftsubnet= (client) in your conn is 216.112.83.64/26. It must -exactly match what pluto is looking for, and it does not.</PRE> -<H3><A name="nosuit">Pluto: ... no suitable connection ...</A></H3> -<P>This is similar to the<A href="#noconn"> no connection known</A> - error, but occurs at a different point in Pluto processing.</P> -<P>Here is one of Claudia's messages explaining the problem:</P> -<PRE>You write, - -> What could be the reason of the following error? -> "no suitable connection for peer '@xforce'" - -When a connection is initiated by the peer, Pluto must choose which entry in -the conf file best matches the incoming connection. A preliminary choice is -made on the basis of source and destination IPs, since that information is -available at that time. - -A payload containing an ID arrives later in the negotiation. Based on this -id and the *id= parameters, Pluto refines its conn selection. ... - -The message "no suitable connection" indicates that in this refining step, -Pluto does not find a connection that matches that ID. - -Please see "Selecting a connection when responding" in man ipsec_pluto for -more details.</PRE> -<P>See also<A href="#conn_name"> Connection names in Pluto error - messages</A>.</P> -<H3><A name="noconn.auth">Pluto: ... no connection has been authorized</A> -</H3> -<P>Here is one of Claudia's messages discussing this problem:</P> -<PRE>You write, - -> May 22 10:46:31 debian Pluto[25834]: packet from x.y.z.p:10014: -> initial Main Mode message from x.y.z.p:10014 - but no connection has been authorized - -This error occurs early in the connection negotiation process, -at the first step of IKE negotiation (Main Mode), which is itself the -first of two negotiation phases involved in creating an IPSec connection. - -Here, Linux FreeS/WAN receives a packet from a potential peer, which -requests that they begin discussing a connection. - -The "no connection has been authorized" means that there is no connection -description in Linux FreeS/WAN's internal database that can be used to -link your ipsec interface with that peer. - -"But of course I configured that connection!" - -It may be that the appropriate connection description exists in ipsec.conf -but has not been added to the database with ipsec auto --add myconn or the -auto=add method. Or, the connection description may be misconfigured. - -The only parameters that are relevant in this decision are left= and right= . -Local and remote ports are also taken into account -- we see that the port -is printed in the message above -- but there is no way to control these -in ipsec.conf. - - -Failure at "no connection has been authorized" is similar to the -"no connection is known for..." error in the FAQ, and the "no suitable -connection" error described in the snapshot's FAQ. In all three cases, -Linux FreeS/WAN is trying to match parameters received in the -negotiation with the connection description in the local config file. - -As it receives more information, its matches take more parameters into -account, and become more precise: first the pair of potential peers, -then the peer IDs, then the endpoints (including any subnets). - -The "no suitable connection for peer *" occurs toward the end of IKE -(Main Mode) negotiation, when the IDs are matched. - -"no connection is known for a/b===c...d" is seen at the beginning of IPSec -(Quick Mode, phase 2) negotiation, when the connections are matched using -left, right, and any information about the subnets.</PRE> -<H3><A name="noDESsupport">Pluto: ... OAKLEY_DES_CBC is not supported.</A> -</H3> -<P>This message occurs when the other system attempts to negotiate a - connection using<A href="#DES"> single DES</A>, which we do not support - because it is<A href="#desnotsecure"> insecure</A>.</P> -<P>Our interoperation document has suggestions for<A href="interop.html#noDES"> - how to deal with</A> systems that attempt to use single DES.</P> -<H3><A name="notransform">Pluto: ... no acceptable transform</A></H3> -<P>This message means that the other gateway has made a proposal for - connection parameters, but nothing they proposed is acceptable to - Pluto. Possible causes include:</P> -<UL> -<LI>misconfiguration on either end</LI> -<LI>policy incompatibilities, for example we require encrypted - connections but they are trying to create one with just authentication</LI> -<LI>interoperation problems, for example they offer only single DES and - FreeS/WAN does not support that. See<A href="interop.html#interop.problem"> - discussion</A> in our interoperation document.</LI> -</UL> -<P>A more detailed explanation, from Pluto programmer Hugh Redelmeier:</P> -<PRE>Background: - -When one IKE system (for example, Pluto) is negotiating with another -to create an SA, the Initiator proposes a bunch of choices and the -Responder replies with one that it has selected. - -The structure of the choices is fairly complicated. An SA payload -contains a list of lists of "Proposals". The outer list is a set of -choices: the selection must be from one element of this list. - -Each of these elements is a list of Proposals. A selection must be -made from each of the elements of the inner list. In other words, -*all* of them apply (that is how, for example, both AH and ESP can -apply at once). - -Within each of these Proposals is a list of Transforms. For each -Proposal selected, one Transform must be selected (in other words, -each Proposal provides a choice of Transforms). - -Each Transform is made up of a list of Attributes describing, well, -attributes. Such as lifetime of the SA. Such as algorithm to be -used. All the Attributes apply to a Transform. - -You will have noticed a pattern here: layers alternate between being -disjunctions ("or") and conjunctions ("and"). - -For Phase 1 / Main Mode (negotiating an ISAKMP SA), this structure is -cut back. There must be exactly one Proposal. So this degenerates to -a list of Transforms, one of which must be chosen. - -In your case, no proposal was considered acceptable to Pluto (the -Responder). So negotiation ceased. Pluto logs the reason it rejects -each Transform. So look back in the log to see what is going wrong.</PRE> -<H3><A name="rsasigkey">rsasigkey dumps core</A></H3> - A comment on this error from Henry: -<PRE>On Fri, 29 Jun 2001, Rodrigo Gruppelli wrote: -> ...Well, it seem that there's -> another problem with it. When I try to generate a pair of RSA keys, -> rsasigkey cores dump... - -*That* is a neon sign flashing "GMP LIBRARY IS BROKEN". Rsasigkey calls -GMP a lot, and our own library a little bit, and that's very nearly all it -does. Barring bugs in its code or our library -- which have happened, but -not very often -- a problem in rsasigkey is a problem in GMP.</PRE> -<P>See the next question for how to deal with GMP errors.</P> -<H3><A name="sig4">!Pluto failure!: ... exited with ... signal 4</A></H3> -<P>Pluto has died. Signal 4 is SIGILL, illegal instruction.</P> -<P>The most likely cause is that your<A href="#GMP"> GMP</A> (GNU - multi-precision) library is compiled for a different processor than - what you are running on. Pluto uses that library for its public key - calculations.</P> -<P>Try getting the GMP sources and recompile for your processor type. - Most Linux distributions will include this source, or you can download - it from the<A href="http://www.swox.com/gmp/"> GMP home page</A>.</P> -<H3><A name="econnrefused">ECONNREFUSED error message</A></H3> -<P>From John Denker, on the mailing list:</P> -<PRE>1) The log message - some IKE message we sent has been rejected with - ECONNREFUSED (kernel supplied no details) -is much more suitable than the previous version. Thanks. - -2) Minor suggestion for further improvement: it might be worth mentioning -that the command - tcpdump -i eth1 icmp[0] != 8 and icmp[0] != 0 -is useful for tracking down the details in question. We shouldn't expect -all IPsec users to figure that out on their own. The log message might -even provide a hint as to where to look in the docs.</PRE> -<P>Reply From Pluto developer Hugh Redelmeier</P> -<PRE>Good idea. - -I've added a bit pluto(8)'s BUGS section along these lines. -I didn't have the heart to lengthen this message.</PRE> -<H3><A name="no_eroute">klips_debug: ... no eroute!</A></H3> -<P>This message means<A href="#KLIPS"> KLIPS</A> has received a packet - for which no IPsec tunnel has been defined.</P> -<P>Here is a more detailed duscussion from the team's tech support - person Claudia Schmeing, responding to a query on the mailing list:</P> -<PRE>> Why ipsec reports no eroute! ???? IP Masq... is disabled. - -In general, more information is required so that people on the list may -give you informed input. See doc/prob.report.</PRE> -<P>The document she refers to has since been replaced by a<A href="#prob.report"> - section</A> of the troubleshooting document.</P> -<PRE>However, I can make some general comments on this type of error. - -This error usually looks something like this (clipped from an archived -message): - -> ttl:64 proto:1 chk:45459 saddr:192.168.1.2 daddr:192.168.100.1 -> ... klips_debug:ipsec_findroute: 192.168.1.2->192.168.100.1 -> ... klips_debug:rj_match: * See if we match exactly as a host destination -> ... klips_debug:rj_match: ** try to match a leaf, t=0xc1a260b0 -> ... klips_debug:rj_match: *** start searching up the tree, t=0xc1a260b0 -> ... klips_debug:rj_match: **** t=0xc1a260c8 -> ... klips_debug:rj_match: **** t=0xc1fe5960 -> ... klips_debug:rj_match: ***** not found. -> ... klips_debug:ipsec_tunnel_start_xmit: Original head/tailroom: 2, 28 -> ... klips_debug:ipsec_tunnel_start_xmit: no eroute!: ts=47.3030, dropping. - - -What does this mean? -- -------------------- - -"eroute" stands for "extended route", and is a special type of route -internal to Linux FreeS/WAN. For more information about this type of route, -see the section of man ipsec_auto on ipsec auto --route. - -"no eroute!" here means, roughly, that Linux FreeS/WAN cannot find an -appropriate tunnel that should have delivered this packet. Linux -FreeS/WAN therefore drops the packet, with the message "no eroute! ... -dropping", on the assumption that this packet is not a legitimate -transmission through a properly constructed tunnel. - - -How does this situation come about? -- ----------------------------------- - -Linux FreeS/WAN has a number of connection descriptions defined in -ipsec.conf. These must be successfully brought "up" to form actual tunnels. -(see doc/setup.html's step 15, man ipsec.conf and man ipsec_auto -for details). - -Such connections are often specific to the endpoints' IPs. However, in -some cases they may be more general, for example in the case of -Road Warriors where left or right is the special value %any. - -When Linux FreeS/WAN receives a packet, it verifies that the packet has -come through a legitimate channel, by checking that there is an -appropriate tunnel through which this packet might legitimately have -arrived. This is the process we see above. - -First, it checks for an eroute that exactly matches the packet. In the -example above, we see it checking for a route that begins at 192.168.1.2 -and ends at 192.168.100.1. This search favours the most specific match that -would apply to the route between these IPs. So, if there is a connection -description exactly matching these IPs, the search will end there. If not, -the code will search for a more general description matching the IPs. -If there is no match, either specific or general, the packet will be -dropped, as we see, above. - -Unless you are working with Road Warriors, only the first, specific part -of the matching process is likely to be relevant to you. - - -"But I defined the tunnel, and it came up, why do I have this error?" -- --------------------------------------------------------------------- - -One of the most common causes of this error is failure to specify enough -connection descriptions to cover all needed tunnels between any two -gateways and their respective subnets. As you have noticed, troubleshooting -this error may be complicated by the use of IP Masq. However, this error is -not limited to cases where IP Masq is used. - -See doc/configuration.html#multitunnel for a detailed example of the -solution to this type of problem.</PRE> -<P>The documentation section she refers to is now<A href="#multitunnel"> - here</A>.</P> -<H3><A name="SAused">... trouble writing to /dev/ipsec ... SA already in - use</A></H3> -<P>This error message occurs when two manual connections are set up with - the same SPI value.</P> -<P>See the FAQ for<A href="#spi_error"> One manual connection works, but - second one fails</A>.</P> -<H3><A name="ignore">... ignoring ... payload</A></H3> -<P>This message is harmless. The IKE protocol provides for a number of - optional messages types:</P> -<UL> -<LI>delete SA</LI> -<LI>initial contact</LI> -<LI>vendor ID</LI> -<LI>...</LI> -</UL> -<P>An implementation is never required to send these, but they are - allowed to. The receiver is not required to do anything with them. - FreeS/WAN ignores them, but notifies you via the logs.</P> -<P>For the "ignoring delete SA Payload" message, see also our discussion - of cleaning up<A href="#deadtunnel"> dead tunnels</A>.</P> -<H3><A name="unknown_rightcert">unknown parameter name "rightcert"</A></H3> -<P>This message can appear when you've upgraded an X.509-enabled Linux - FreeS/WAN with a vanilla Linux FreeS/WAN. To use your X.509 configs you - will need to overwrite the new install with<A HREF="http://www.freeswan.ca"> - Super FreeS/WAN</A>, or add the<A HREF="http://www.strongsec.ca/freeswan"> - X.509 patch</A> by hand.</P> -<H2><A name="spam">Why don't you restrict the mailing lists to reduce - spam?</A></H2> -<P>As a matter of policy, some of our<A href="mail.html"> mailing lists</A> - need to be open to non-subscribers. Project management feel strongly - that maintaining this openness is more important than blocking spam.</P> -<UL> -<LI>Users should be able to get help or report bugs without subscribing.</LI> -<LI>Even a user who is subscribed may not have access to his or her - subscribed account when he or she needs help, miles from home base in - the middle of setting up a client's gateway.</LI> -<LI>There is arguably a legal requirement for this policy. A US resident - or citizen could be charged under munitions export laws for providing - technical assistance to a foreign cryptographic project. Such a charge - would be more easily defended if the discussion takes place in public, - on an open list.</LI> -</UL> -<P>This has been discussed several times at some length on the list. See - the<A href="#archive"> list archives</A>. Bringing the topic up again - is unlikely to be useful. Please don't. Or at the very least, please - don't without reading the archives and being certain that whatever you - are about to suggest has not yet been discussed.</P> -<P>Project technical lead Henry Spencer summarised one discussion:</P> -<BLOCKQUOTE> For the third and last time: this list *will* *not* do - address-based filtering. This is a policy decision, not an - implementation problem. The decision is final, and is not open to - discussion. This needs to be communicated better to people, and steps - are being taken to do that.</BLOCKQUOTE> -<P>Adding this FAQ section is one of the steps he refers to.</P> -<P>You have various options other than just putting up with the spam, - filtering it yourself, or unsubscribing:</P> -<UL> -<LI>subscribe only to one or both of our lists with restricted posting - rules: -<UL> -<LI><A href="mailto:briefs@lists.freeswan.org?body=subscribe">briefs</A> -, weekly list summaries</LI> -<LI><A href="mailto:announce@lists.freeswan.org?body=subscribe">announce</A> -, project-related announcements</LI> -</UL> -</LI> -<LI>read the other lists via the<A href="#archive"> archives</A></LI> -</UL> -<P>A number of tools are available to filter mail.</P> -<UL> -<LI>Many mail readers include some filtering capability.</LI> -<LI>Many Linux distributions include<A href="http://www.procmail.org/"> - procmail(8)</A> for server-side filtering.</LI> -<LI>The<A href="http://www.spambouncer.org/"> Spam Bouncer</A> is a set - of procmail(8) filters designed to combat spam.</LI> -<LI>Roaring Penguin have a<A href="http://www.roaringpenguin.com/mimedefang/"> - MIME defanger</A> that removes potentially dangerous attachments.</LI> -</UL> -<P>If you use your ISP's mail server rather than running your own, - consider suggesting to the ISP that they tag suspected spam as<A href="http://www.msen.com/1997/spam.html#SUSPECTED"> - this ISP</A> does. They could just refuse mail from dubious sources, - but that is tricky and runs some risk of losing valuable mail or - senselessly annoying senders and their admins. However, they can safely - tag and deliver dubious mail. The tags can greatly assist your - filtering.</P> -<P>For information on tracking down spammers, see these<A href="http://www.rahul.net/falk/#howtos"> - HowTos</A>, or the<A href="http://www.sputum.com/index2.html"> Sputum</A> - site. Sputum have a Linux anti-spam screensaver available for download.</P> -<P>Here is a more detailed message from Henry:</P> -<PRE>On Mon, 15 Jan 2001, Jay Vaughan wrote: -> I know I'm flogging a dead horse here, but I'm curious as to the reasons for -> an aversion for a subscriber-only mailing list? - -Once again: for legal reasons, it is important that discussions of these -things be held in a public place -- the list -- and we do not want to -force people to subscribe to the list just to ask one question, because -that may be more than merely inconvenient for them. There are also real -difficulties with people who are temporarily forced to use alternate -addresses; that is precisely the time when they may be most in need of -help, yet a subscribers-only policy shuts them out. - -These issues do not apply to most mailing lists, but for a list that is -(necessarily) the primary user support route for a crypto package, they -are very important. This is *not* an ordinary mailing list; it has to -function under awkward constraints that make various simplistic solutions -inapplicable or undesirable. - -> We're *ALL* sick of hearing about list management problems, not just you -> old-timers, so why don't you DO SOMETHING EFFECTIVE ABOUT IT... - -Because it's a lot harder than it looks, and many existing "solutions" -have problems when examined closely. - -> A suggestion for you, based on 10 years of experience with management of my -> own mailing lists would be to use mailman, which includes pretty much every -> feature under the sun that you guys need and want, plus some. The URL for -> mailman... - -I assure you, we're aware of mailman. Along with a whole bunch of others, -including some you almost certainly have never heard of (I hadn't!). - -> As for the argument that the list shouldn't be configured to enforce -> subscription - I contend that it *SHOULD* AT LEAST require manual address -> verification in order for posts to be redirected. - -You do realize, I hope, that interposing such a manual step might cause -your government to decide that this is not truly a public forum, and thus -you could go to jail if you don't get approval from them before mailing to -it? If you think this sounds irrational, your government is noted for -making irrational decisions in this area; we can't assume that they will -suddenly start being sensible. See above about awkward constraints. You -may be willing to take the risk, but we can't, in good conscience, insist -that all users with problems do so. - - Henry Spencer - henry@spsystems.net</PRE> -<P>and a message on the topic from project leader John Gilmore:</P> -<PRE>Subject: Re: The linux-ipsec list's topic - Date: Sat, 30 Dec 2000 - From: John Gilmore <gnu@toad.com> - -I'll post this single message, once only, in this discussion, and then -not burden the list with any further off-topic messages. I encourage -everyone on the list to restrain themself from posting ANY off-topic -messages to the linux-ipsec list. - -The topic of the linux-ipsec mailing list is the FreeS/WAN software. - -I frequently see "discussions about spam on a list" overwhelm the -volume of "actual spam" on a list. BOTH kinds of messages are -off-topic messages. Twenty anti-spam messages take just as long to -detect and discard as twenty spam messages. - -The Linux-ipsec list encourages on-topic messages from people who have -not joined the list itself. We will not censor messages to the list -based on where they originate, or what return address they contain. -In other words, non-subscribers ARE allowed to post, and this will not -change. My own valid contributions have been rejected out-of-hand by -too many other mailing lists for me to want to impose that censorship -on anybody else's contributions. And every day I see the damage that -anti-spam zeal is causing in many other ways; that zeal is far more -damaging to the culture of the Internet than the nuisance of spam. - -In general, it is the responsibility of recipients to filter, -prioritize, or otherwise manage the handling of email that comes to -them. It is not the responsibility of the rest of the Internet -community to refrain from sending messages to recipients that they -might not want to see. If your software infrastructure for managing -your incoming email is insufficient, then improve it. If you think -the signal-to-noise ratio on linux-ipsec is too poor, then please -unsubscribe. But don't further increase the noise by posting to the -linux-ipsec list about those topics. - - John Gilmore - founder & sponsor, FreeS/WAN project</PRE> -<HR> -<H1><A name="manpages">FreeS/WAN manual pages</A></H1> -<P>The various components of Linux FreeS/WAN are of course documented in - standard Unix manual pages, accessible via the man(1) command.</P> -<P>Links here take you to an HTML version of the man pages.</P> -<H2><A name="man.file">Files</A></H2> -<DL> -<DT><A href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</A></DT> -<DD>IPsec configuration and connections</DD> -<DT><A href="manpage.d/ipsec.secrets.5.html">ipsec.secrets(5)</A></DT> -<DD>secrets for IKE authentication, either pre-shared keys or RSA - private keys</DD> -</DL> -<P>These files are also discussed in the<A href="config.html"> - configuration</A> section.</P> -<H2><A name="man.command">Commands</A></H2> -<P>Many users will never give most of the FreeS/WAN commands directly. - Configure the files listed above correctly and everything should be - automatic.</P> -<P>The exceptions are commands for mainpulating the<A href="#RSA"> RSA</A> - keys used in Pluto authentication:</P> -<DL> -<DT><A href="manpage.d/ipsec_rsasigkey.8.html">ipsec_rsasigkey(8)</A></DT> -<DD>generate keys</DD> -<DT><A href="manpage.d/ipsec_newhostkey.8.html">ipsec_newhostkey(8)</A></DT> -<DD>generate keys in a convenient format</DD> -<DT><A href="manpage.d/ipsec_showhostkey.8.html">ipsec_showhostkey(8)</A> -</DT> -<DD>extract<A href="#RSA"> RSA</A> keys from<A href="manpage.d/ipsec.secrets.5.html"> - ipsec.secrets(5)</A> (or optionally, another file) and format them for - insertion in<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5)</A> or - in DNS records</DD> -</DL> -<P>Note that:</P> -<UL> -<LI>These keys are for<STRONG> authentication only</STRONG>. They are<STRONG> - not secure for encryption</STRONG>.</LI> -<LI>The utility uses random(4) as a source of<A href="#random"> random - numbers</A>. This may block for some time if there is not enough - activity on the machine to provide the required entropy. You may want - to give it some bogus activity such as random mouse movements or some - command such as<NOBR> <TT>du /usr > /dev/null &</TT>.</LI> -</UL> -<P>The following commands are fairly likely to be used, if only for - testing and status checks:</P> -<DL> -<DT><A href="manpage.d/ipsec.8.html">ipsec(8)</A></DT> -<DD>invoke IPsec utilities</DD> -<DT><A href="manpage.d/ipsec_setup.8.html">ipsec_setup(8)</A></DT> -<DD>control IPsec subsystem</DD> -<DT><A href="manpage.d/ipsec_auto.8.html">ipsec_auto(8)</A></DT> -<DD>control automatically-keyed IPsec connections</DD> -<DT><A href="manpage.d/ipsec_manual.8.html">ipsec_manual(8)</A></DT> -<DD>take manually-keyed IPsec connections up and down</DD> -<DT><A href="manpage.d/ipsec_ranbits.8.html">ipsec_ranbits(8)</A></DT> -<DD>generate random bits in ASCII form</DD> -<DT><A href="manpage.d/ipsec_look.8.html">ipsec_look(8)</A></DT> -<DD>show minimal debugging information</DD> -<DT><A href="manpage.d/ipsec_barf.8.html">ipsec_barf(8)</A></DT> -<DD>spew out collected IPsec debugging information</DD> -</DL> -<P>The lower-level utilities listed below are normally invoked via - scripts listed above, but they can also be used directly when required.</P> -<DL> -<DT><A href="manpage.d/ipsec_eroute.8.html">ipsec_eroute(8)</A></DT> -<DD>manipulate IPsec extended routing tables</DD> -<DT><A href="manpage.d/ipsec_klipsdebug.8.html">ipsec_klipsdebug(8)</A></DT> -<DD>set Klips (kernel IPsec support) debug features and level</DD> -<DT><A href="manpage.d/ipsec_pluto.8.html">ipsec_pluto(8)</A></DT> -<DD>IPsec IKE keying daemon</DD> -<DT><A href="manpage.d/ipsec_spi.8.html">ipsec_spi(8)</A></DT> -<DD>manage IPsec Security Associations</DD> -<DT><A href="manpage.d/ipsec_spigrp.8.html">ipsec_spigrp(8)</A></DT> -<DD>group/ungroup IPsec Security Associations</DD> -<DT><A href="manpage.d/ipsec_tncfg.8.html">ipsec_tncfg(8)</A></DT> -<DD>associate IPsec virtual interface with real interface</DD> -<DT><A href="manpage.d/ipsec_whack.8.html">ipsec_whack(8)</A></DT> -<DD>control interface for IPsec keying daemon</DD> -</DL> -<H2><A name="man.lib">Library routines</A></H2> -<DL> -<DT><A href="manpage.d/ipsec_atoaddr.3.html">ipsec_atoaddr(3)</A></DT> -<DT><A href="manpage.d/ipsec_addrtoa.3.html">ipsec_addrtoa(3)</A></DT> -<DD>convert Internet addresses to and from ASCII</DD> -<DT><A href="manpage.d/ipsec_atosubnet.3.html">ipsec_atosubnet(3)</A></DT> -<DT><A href="manpage.d/ipsec_subnettoa.3.html">ipsec_subnettoa(3)</A></DT> -<DD>convert subnet/mask ASCII form to and from addresses</DD> -<DT><A href="manpage.d/ipsec_atoasr.3.html">ipsec_atoasr(3)</A></DT> -<DD>convert ASCII to Internet address, subnet, or range</DD> -<DT><A href="manpage.d/ipsec_rangetoa.3.html">ipsec_rangetoa(3)</A></DT> -<DD>convert Internet address range to ASCII</DD> -<DT>ipsec_atodata(3)</DT> -<DT><A href="manpage.d/ipsec_datatoa.3.html">ipsec_datatoa(3)</A></DT> -<DD>convert binary data from and to ASCII formats</DD> -<DT><A href="manpage.d/ipsec_atosa.3.html">ipsec_atosa(3)</A></DT> -<DT><A href="manpage.d/ipsec_satoa.3.html">ipsec_satoa(3)</A></DT> -<DD>convert IPsec Security Association IDs to and from ASCII</DD> -<DT><A href="manpage.d/ipsec_atoul.3.html">ipsec_atoul(3)</A></DT> -<DT><A href="manpage.d/ipsec_ultoa.3.html">ipsec_ultoa(3)</A></DT> -<DD>convert unsigned-long numbers to and from ASCII</DD> -<DT><A href="manpage.d/ipsec_goodmask.3.html">ipsec_goodmask(3)</A></DT> -<DD>is this Internet subnet mask a valid one?</DD> -<DT><A href="manpage.d/ipsec_masktobits.3.html">ipsec_masktobits(3)</A></DT> -<DD>convert Internet subnet mask to bit count</DD> -<DT><A href="manpage.d/ipsec_bitstomask.3.html">ipsec_bitstomask(3)</A></DT> -<DD>convert bit count to Internet subnet mask</DD> -<DT><A href="manpage.d/ipsec_optionsfrom.3.html">ipsec_optionsfrom(3)</A> -</DT> -<DD>read additional ``command-line'' options from file</DD> -<DT><A href="manpage.d/ipsec_subnetof.3.html">ipsec_subnetof(3)</A></DT> -<DD>given Internet address and subnet mask, return subnet number</DD> -<DT><A href="manpage.d/ipsec_hostof.3.html">ipsec_hostof(3)</A></DT> -<DD>given Internet address and subnet mask, return host part</DD> -<DT><A href="manpage.d/ipsec_broadcastof.3.html">ipsec_broadcastof(3)</A> -</DT> -<DD>given Internet address and subnet mask, return broadcast address</DD> -</DL> -<HR> -<H1><A name="firewall">FreeS/WAN and firewalls</A></H1> -<P>FreeS/WAN, or other IPsec implementations, frequently run on gateway - machines, the same machines running firewall or packet filtering code. - This document discusses the relation between the two.</P> -<P>The firewall code in 2.4 and later kernels is called Netfilter. The - user-space utility to manage a firewall is iptables(8). See the<A href="http://netfilter.samba.org"> - netfilter/iptables web site</A> for details.</P> -<H2><A name="filters">Filtering rules for IPsec packets</A></H2> -<P>The basic constraint is that<STRONG> an IPsec gateway must have - packet filters that allow IPsec packets</STRONG>, at least when talking - to other IPsec gateways:</P> -<UL> -<LI>UDP port 500 for<A href="#IKE"> IKE</A> negotiations</LI> -<LI>protocol 50 if you use<A href="#ESP"> ESP</A> encryption and/or - authentication (the typical case)</LI> -<LI>protocol 51 if you use<A href="#AH"> AH</A> packet-level - authentication</LI> -</UL> -<P>Your gateway and the other IPsec gateways it communicates with must - be able to exchange these packets for IPsec to work. Firewall rules - must allow UDP 500 and at least one of<A href="#AH"> AH</A> or<A href="#ESP"> - ESP</A> on the interface that communicates with the other gateway.</P> -<P>For nearly all FreeS/WAN applications, you must allow UDP port 500 - and the ESP protocol.</P> -<P>There are two ways to set this up:</P> -<DL> -<DT>easier but less flexible</DT> -<DD>Just set up your firewall scripts at boot time to allow IPsec - packets to and from your gateway. Let FreeS/WAN reject any bogus - packets.</DD> -<DT>more work, giving you more precise control</DT> -<DD>Have the<A href="manpage.d/ipsec_pluto.8.html"> ipsec_pluto(8)</A> - daemon call scripts to adjust firewall rules dynamically as required. - This is done by naming the scripts in the<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A> variables<VAR> prepluto=</VAR>,<VAR> postpluto=</VAR> -,<VAR> leftupdown=</VAR> and<VAR> rightupdown=</VAR>.</DD> -</DL> -<P>Both methods are described in more detail below.</P> -<H2><A name="examplefw">Firewall configuration at boot</A></H2> -<P>It is possible to set up both firewalling and IPsec with appropriate - scripts at boot and then not use<VAR> leftupdown=</VAR> and<VAR> - rightupdown=</VAR>, or use them only for simple up and down operations.</P> -<P>Basically, the technique is</P> -<UL> -<LI>allow IPsec packets (typically, IKE on UDP port 500 plus ESP, - protocol 50) -<UL> -<LI>incoming, if the destination address is your gateway (and - optionally, only from known senders)</LI> -<LI>outgoing, with the from address of your gateway (and optionally, - only to known receivers)</LI> -</UL> -</LI> -<LI>let<A href="#Pluto"> Pluto</A> deal with IKE</LI> -<LI>let<A href="#KLIPS"> KLIPS</A> deal with ESP</LI> -</UL> -<P>Since Pluto authenticates its partners during the negotiation, and - KLIPS drops packets for which no tunnel has been negotiated, this may - be all you need.</P> -<H3><A name="simple.rules">A simple set of rules</A></H3> -<P>In simple cases, you need only a few rules, as in this example:</P> -<PRE># allow IPsec -# -# IKE negotiations -iptables -I INPUT -p udp --sport 500 --dport 500 -j ACCEPT -iptables -I OUTPUT -p udp --sport 500 --dport 500 -j ACCEPT -# ESP encryption and authentication -iptables -I INPUT -p 50 -j ACCEPT -iptables -I OUTPUT -p 50 -j ACCEPT -</PRE> -<P>This should be all you need to allow IPsec through<VAR> lokkit</VAR>, - which ships with Red Hat 9, on its medium security setting. Once you've - tweaked to your satisfaction, save your active rule set with:</P> -<PRE>service iptables save</PRE> -<H3><A name="complex.rules">Other rules</A></H3> - You can add additional rules, or modify existing ones, to work with - IPsec and with your network and policies. We give a some examples in - this section. -<P>However, while it is certainly possible to create an elaborate set of - rules yourself (please let us know via the<A href="mail.html"> mailing - list</A> if you do), it may be both easier and more secure to use a set - which has already been published and tested.</P> -<P>The published rule sets we know of are described in the<A href="#rules.pub"> - next section</A>.</P> -<H4><A NAME="7_2_2_1">Adding additional rules</A></H4> - If necessary, you can add additional rules to: -<DL> -<DT>reject IPsec packets that are not to or from known gateways</DT> -<DD>This possibility is discussed in more detail<A href="#unknowngate"> - later</A></DD> -<DT>allow systems behind your gateway to build IPsec tunnels that pass - through the gateway</DT> -<DD>This possibility is discussed in more detail<A href="#through"> - later</A></DD> -<DT>filter incoming packets emerging from KLIPS.</DT> -<DD>Firewall rules can recognise packets emerging from IPsec. They are - marked as arriving on an interface such as<VAR> ipsec0</VAR>, rather - than<VAR> eth0</VAR>,<VAR> ppp0</VAR> or whatever.</DD> -</DL> -<P>It is therefore reasonably straightforward to filter these packets in - whatever way suits your situation.</P> -<H4><A NAME="7_2_2_2">Modifying existing rules</A></H4> -<P>In some cases rules that work fine before you add IPsec may require - modification to work with IPsec.</P> -<P>This is especially likely for rules that deal with interfaces on the - Internet side of your system. IPsec adds a new interface; often the - rules must change to take account of that.</P> -<P>For example, consider the rules given in<A href="http://www.netfilter.org/documentation/HOWTO//packet-filtering-HOWTO-5.html"> - this section</A> of the Netfilter documentation:</P> -<PRE>Most people just have a single PPP connection to the Internet, and don't -want anyone coming back into their network, or the firewall: - - ## Insert connection-tracking modules (not needed if built into kernel). - # insmod ip_conntrack - # insmod ip_conntrack_ftp - - ## Create chain which blocks new connections, except if coming from inside. - # iptables -N block - # iptables -A block -m state --state ESTABLISHED,RELATED -j ACCEPT - # iptables -A block -m state --state NEW -i ! ppp0 -j ACCEPT - # iptables -A block -j DROP - - ## Jump to that chain from INPUT and FORWARD chains. - # iptables -A INPUT -j block - # iptables -A FORWARD -j block</PRE> -<P>On an IPsec gateway, those rules may need to be modified. The above - allows new connections from<EM> anywhere except ppp0</EM>. That means - new connections from ipsec0 are allowed.</P> -<P>Do you want to allow anyone who can establish an IPsec connection to - your gateway to initiate TCP connections to any service on your - network? Almost certainly not if you are using opportunistic - encryption. Quite possibly not even if you have only explicitly - configured connections.</P> -<P>To disallow incoming connections from ipsec0, change the middle - section above to:</P> -<PRE> ## Create chain which blocks new connections, except if coming from inside. - # iptables -N block - # iptables -A block -m state --state ESTABLISHED,RELATED -j ACCEPT - # iptables -A block -m state --state NEW -i ppp+ -j DROP - # iptables -A block -m state --state NEW -i ipsec+ -j DROP - # iptables -A block -m state --state NEW -i -j ACCEPT - # iptables -A block -j DROP</PRE> -<P>The original rules accepted NEW connections from anywhere except - ppp0. This version drops NEW connections from any PPP interface (ppp+) - and from any ipsec interface (ipsec+), then accepts the survivors.</P> -<P>Of course, these are only examples. You will need to adapt them to - your own situation.</P> -<H3><A name="rules.pub">Published rule sets</A></H3> -<P>Several sets of firewall rules that work with FreeS/WAN are - available.</P> -<H4><A name="Ranch.trinity">Scripts based on Ranch's work</A></H4> -<P>One user, Rob Hutton, posted his boot time scripts to the mailing - list, and we included them in previous versions of this documentation. - They are still available from our<A href="http://www.freeswan.org/freeswan_trees/freeswan-1.5/doc/firewall.html#examplefw"> - web site</A>. However, they were for an earlier FreeS/WAN version so we - no longer recommend them. Also, they had some bugs. See this<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/04/msg00316.html"> - message</A>.</P> -<P>Those scripts were based on David Ranch's scripts for his "Trinity - OS" for setting up a secure Linux. Check his<A href="http://www.ecst.csuchico.edu/~dranch/LINUX/index-linux.html"> - home page</A> for the latest version and for information on his<A href="#ranch"> - book</A> on securing Linux. If you are going to base your firewalling - on Ranch's scripts, we recommend using his latest version, and sending - him any IPsec modifications you make for incorporation into later - versions.</P> -<H4><A name="seawall">The Seattle firewall</A></H4> -<P>We have had several mailing lists reports of good results using - FreeS/WAN with Seawall (the Seattle Firewall). See that project's<A href="http://seawall.sourceforge.net/"> - home page</A> on Sourceforge.</P> -<H4><A name="rcf">The RCF scripts</A></H4> -<P>Another set of firewall scripts with IPsec support are the RCF or - rc.firewall scripts. See their<A href="http://jsmoriss.mvlan.net/linux/rcf.html"> - home page</A>.</P> -<H4><A name="asgard">Asgard scripts</A></H4> -<P><A href="http://heimdall.asgardsrealm.net/linux/firewall/">Asgard's - Realm</A> has set of firewall scripts with FreeS/WAN support, for 2.4 - kernels and iptables.</P> -<H4><A name="user.scripts">User scripts from the mailing list</A></H4> -<P>One user gave considerable detail on his scripts, including - supporting<A href="#IPX"> IPX</A> through the tunnel. His message was - too long to conveniently be quoted here, so I've put it in a<A href="user_examples.html"> - separate file</A>.</P> -<H2><A name="updown">Calling firewall scripts, named in ipsec.conf(5)</A> -</H2> -<P>The<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5)</A> - configuration file has three pairs of parameters used to specify an - interface between FreeS/WAN and firewalling code.</P> -<P>Note that using these is not required if you have a static firewall - setup. In that case, you just set your firewall up at boot time (in a - way that permits the IPsec connections you want) and do not change it - thereafter. Omit all the FreeS/WAN firewall parameters and FreeS/WAN - will not attempt to adjust firewall rules at all. See<A href="#examplefw"> - above</A> for some information on appropriate scripts.</P> -<P>However, if you want your firewall rules to change when IPsec - connections change, then you need to use these parameters.</P> -<H3><A name="pre_post">Scripts called at IPsec start and stop</A></H3> -<P>One pair of parmeters are set in the<VAR> config setup</VAR> section - of the<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5)</A> file and - affect all connections:</P> -<DL> -<DT>prepluto=</DT> -<DD>script to be called before<A href="manpage.d/ipsec_pluto.8.html"> - pluto(8)</A> IKE daemon is started.</DD> -<DT>postpluto=</DT> -<DD>script to be called after<A href="manpage.d/ipsec_pluto.8.html"> - pluto(8)</A> IKE daemon is stopped.</DD> -</DL> - These parameters allow you to change firewall parameters whenever IPsec - is started or stopped. -<P>They can also be used in other ways. For example, you might have<VAR> - prepluto</VAR> add a module to your kernel for the secure network - interface or make a dialup connection, and then have<VAR> postpluto</VAR> - remove the module or take the connection down.</P> -<H3><A name="up_down">Scripts called at connection up and down</A></H3> -<P>The other parameters are set in connection descriptions. They can be - set in individual connection descriptions, and could even call - different scripts for each connection for maximum flexibility. In most - applications, however, it makes sense to use only one script and to - call it from<VAR> conn %default</VAR> section so that it applies to all - connections.</P> -<P>You can:</P> -<DL> -<DT><STRONG>either</STRONG></DT> -<DD>set<VAR> leftfirewall=yes</VAR> or<VAR> rightfirewall=yes</VAR> to - use our supplied default script</DD> -<DT><STRONG>or</STRONG></DT> -<DD>assign a name in a<VAR> leftupdown=</VAR> or<VAR> rightupdown=</VAR> - line to use your own script</DD> -</DL> -<P>Note that<STRONG> only one of these should be used</STRONG>. You - cannot sensibly use both. Since<STRONG> our default script is obsolete</STRONG> - (designed for firewalls using<VAR> ipfwadm(8)</VAR> on 2.0 kernels), - most users who need this service will<STRONG> need to write a custom - script</STRONG>.</P> -<H4><A name="fw.default">The default script</A></H4> -<P>We supply a default script named<VAR> _updown</VAR>.</P> -<DL> -<DT>leftfirewall=</DT> -<DD></DD> -<DT>rightfirewall=</DT> -<DD>indicates that the gateway is doing firewalling and that<A href="manpage.d/ipsec_pluto.8.html"> - pluto(8)</A> should poke holes in the firewall as required.</DD> -</DL> -<P>Set these to<VAR> yes</VAR> and Pluto will call our default script<VAR> - _updown</VAR> with appropriate arguments whenever it:</P> -<UL> -<LI>starts or stops IPsec services</LI> -<LI>brings a connection up or down</LI> -</UL> -<P>The supplied default<VAR> _updown</VAR> script is appropriate for - simple cases using the<VAR> ipfwadm(8)</VAR> firewalling package.</P> -<H4><A name="userscript">User-written scripts</A></H4> -<P>You can also write your own script and have Pluto call it. Just put - the script's name in one of these<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A> lines:</P> -<DL> -<DT>leftupdown=</DT> -<DD></DD> -<DT>rightupdown=</DT> -<DD>specifies a script to call instead of our default script<VAR> - _updown</VAR>.</DD> -</DL> -<P>Your script should take the same arguments and use the same - environment variables as<VAR> _updown</VAR>. See the "updown command" - section of the<A href="manpage.d/ipsec_pluto.8.html"> ipsec_pluto(8)</A> - man page for details.</P> -<P>Note that<STRONG> you should not modify our _updown script in place</STRONG> -. If you did that, then upgraded FreeS/WAN, the upgrade would install a - new default script, overwriting your changes.</P> -<H3><A name="ipchains.script">Scripts for ipchains or iptables</A></H3> -<P>Our<VAR> _updown</VAR> is for firewalls using<VAR> ipfwadm(8)</VAR>, - the firewall code for the 2.0 series of Linux kernels. If you are using - the more recent packages<VAR> ipchains(8)</VAR> (for 2.2 kernels) or<VAR> - iptables(8)</VAR> (2.4 kernels), then you must do one of:</P> -<UL> -<LI>use static firewall rules which are set up at boot time as described<A -href="#examplefw"> above</A> and do not need to be changed by Pluto</LI> -<LI>limit yourself to ipchains(8)'s ipfwadm(8) emulation mode in order - to use our script</LI> -<LI>write your own script and call it with<VAR> leftupdown</VAR> and<VAR> - rightupdown</VAR>.</LI> -</UL> -<P>You can write a script to do whatever you need with firewalling. - Specify its name in a<VAR> [left|right]updown=</VAR> parameter in<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A> and Pluto will automatically call it for you.</P> -<P>The arguments Pluto passes such a script are the same ones it passes - to our default _updown script, so the best way to build yours is to - copy ours and modify the copy.</P> -<P>Note, however, that<STRONG> you should not modify our _updown script - in place</STRONG>. If you did that, then upgraded FreeS/WAN, the - upgrade would install a new default script, overwriting your changes.</P> -<H2><A name="NAT">A complication: IPsec vs. NAT</A></H2> -<P><A href="#NAT.gloss">Network Address Translation</A>, also known as - IP masquerading, is a method of allocating IP addresses dynamically, - typically in circumstances where the total number of machines which - need to access the Internet exceeds the supply of IP addresses.</P> -<P>Any attempt to perform NAT operations on IPsec packets<EM> between - the IPsec gateways</EM> creates a basic conflict:</P> -<UL> -<LI>IPsec wants to authenticate packets and ensure they are unaltered on - a gateway-to-gateway basis</LI> -<LI>NAT rewrites packet headers as they go by</LI> -<LI>IPsec authentication fails if packets are rewritten anywhere between - the IPsec gateways</LI> -</UL> -<P>For<A href="#AH"> AH</A>, which authenticates parts of the packet - header including source and destination IP addresses, this is fatal. If - NAT changes those fields, AH authentication fails.</P> -<P>For<A href="#IKE"> IKE</A> and<A href="#ESP"> ESP</A> it is not - necessarily fatal, but is certainly an unwelcome complication.</P> -<H3><A name="nat_ok">NAT on or behind the IPsec gateway works</A></H3> -<P>This problem can be avoided by having the masquerading take place<EM> - on or behind</EM> the IPsec gateway.</P> -<P>This can be done physically with two machines, one physically behind - the other. A picture, using SG to indicate IPsec<STRONG> S</STRONG> -ecurity<STRONG> G</STRONG>ateways, is:</P> -<PRE> clients --- NAT ----- SG ---------- SG - two machines</PRE> -<P>In this configuration, the actual client addresses need not be given - in the<VAR> leftsubnet=</VAR> parameter of the FreeS/WAN connection - description. The security gateway just delivers packets to the NAT box; - it needs only that machine's address. What that machine does with them - does not affect FreeS/WAN.</P> -<P>A more common setup has one machine performing both functions:</P> -<PRE> clients ----- NAT/SG ---------------SG - one machine</PRE> -<P>Here you have a choice of techniques depending on whether you want to - make your client subnet visible to clients on the other end:</P> -<UL> -<LI>If you want the single gateway to behave like the two shown above, - with your clients hidden behind the NAT, then omit the<VAR> leftsubnet=</VAR> - parameter. It then defaults to the gateway address. Clients on the - other end then talk via the tunnel only to your gateway. The gateway - takes packets emerging from the tunnel, applies normal masquerading, - and forwards them to clients.</LI> -<LI>If you want to make your client machines visible, then give the - client subnet addresses as the<VAR> leftsubnet=</VAR> parameter in the - connection description and -<DL> -<DT>either</DT> -<DD>set<VAR> leftfirewall=yes</VAR> to use the default<VAR> updown</VAR> - script</DD> -<DT>or</DT> -<DD>use your own script by giving its name in a<VAR> leftupdown=</VAR> - parameter</DD> -</DL> - These scripts are described in their own<A href="#updown"> section</A>. -<P>In this case, no masquerading is done. Packets to or from the client - subnet are encrypted or decrypted without any change to their client - subnet addresses, although of course the encapsulating packets use - gateway addresses in their headers. Clients behind the right security - gateway see a route via that gateway to the left subnet.</P> -</LI> -</UL> -<H3><A name="nat_bad">NAT between gateways is problematic</A></H3> -<P>We recommend not trying to build IPsec connections which pass through - a NAT machine. This setup poses problems:</P> -<PRE> clients --- SG --- NAT ---------- SG</PRE> -<P>If you must try it, some references are:</P> -<UL> -<LI>Jean_Francois Nadeau's document on doing<A href="http://jixen.tripod.com/#NATed gateways"> - IPsec behind NAT</A></LI> -<LI><A href="#VPN.masq">VPN masquerade patches</A> to make a Linux NAT - box handle IPsec packets correctly</LI> -</UL> -<H3><A name="NAT.ref">Other references on NAT and IPsec</A></H3> -<P>Other documents which may be relevant include:</P> -<UL> -<LI>an Internet Draft on<A href="http://search.ietf.org/internet-drafts/draft-aboba-nat-ipsec-04.txt"> - IPsec and NAT</A> which may eventually evolve into a standard solution - for this problem.</LI> -<LI>an informational<A href="http://www.cis.ohio-state.edu/rfc/rfc2709.txt"> - RFC</A>,<CITE> Security Model with Tunnel-mode IPsec for NAT Domains</CITE> -.</LI> -<LI>an<A href="http://www.cisco.com/warp/public/759/ipj_3-4/ipj_3-4_nat.html"> - article</A> in Cisco's<CITE> Internet Protocol Journal</CITE></LI> -</UL> -<H2><A name="complications">Other complications</A></H2> -<P>Of course simply allowing UDP 500 and ESP packets is not the whole - story. Various other issues arise in making IPsec and packet filters - co-exist and even co-operate. Some of them are summarised below.</P> -<H3><A name="through">IPsec<EM> through</EM></A> the gateway</H3> -<P>Basic IPsec packet filtering rules deal only with packets addressed - to or sent from your IPsec gateway.</P> -<P>It is a separate policy decision whether to permit such packets to - pass through the gateway so that client machines can build end-to-end - IPsec tunnels of their own. This may not be practical if you are using<A -href="#NAT"> NAT (IP masquerade)</A> on your gateway, and may conflict - with some corporate security policies.</P> -<P>Where possible, allowing this is almost certainly a good idea. Using - IPsec on an end-to-end basis is more secure than gateway-to-gateway.</P> -<P>Doing it is quite simple. You just need firewall rules that allow UDP - port 500 and protocols 50 and 51 to pass through your gateway. If you - wish, you can of course restrict this to certain hosts.</P> -<H3><A name="ipsec_only">Preventing non-IPsec traffic</A></H3> - You can also filter<EM> everything but</EM> UDP port 500 and ESP or AH - to restrict traffic to IPsec only, either for anyone communicating with - your host or just for specific partners. -<P>One application of this is for the telecommuter who might have:</P> -<PRE> Sunset==========West------------------East ================= firewall --- the Internet - home network untrusted net corporate network</PRE> -<P>The subnet on the right is 0.0.0.0/0, the whole Internet. The West - gateway is set up so that it allows only IPsec packets to East in or - out.</P> -<P>This configuration is used in AT&T Research's network. For details, - see the<A href="#applied"> papers</A> links in our introduction.</P> -<P>Another application would be to set up firewall rules so that an - internal machine, such as an employees-only web server, could not talk - to the outside world except via specific IPsec tunnels.</P> -<H3><A name="unknowngate">Filtering packets from unknown gateways</A></H3> -<P>It is possible to use firewall rules to restrict UDP 500, ESP and AH - packets so that these packets are accepted only from known gateways. - This is not strictly necessary since FreeS/WAN will discard packets - from unknown gateways. You might, however, want to do it for any of a - number of reasons. For example:</P> -<UL> -<LI>Arguably, "belt and suspenders" is the sensible approach to - security. If you can block a potential attack in two ways, use both. - The only question is whether to look for a third way after implementing - the first two.</LI> -<LI>Some admins may prefer to use the firewall code this way because - they prefer firewall logging to FreeS/WAN's logging.</LI> -<LI>You may need it to implement your security policy. Consider an - employee working at home, and a policy that says traffic from the home - system to the Internet at large must go first via IPsec to the - corporate LAN and then out to the Internet via the corporate firewall. - One way to do that is to make<VAR> ipsec0</VAR> the default route on - the home gateway and provide exceptions only for UDP 500 and ESP to the - corporate gateway. Everything else is then routed via the tunnel to the - corporate gateway.</LI> -</UL> -<P>It is not possible to use only static firewall rules for this - filtering if you do not know the other gateways' IP addresses in - advance, for example if you have "road warriors" who may connect from a - different address each time or if want to do<A href="#carpediem"> - opportunistic encryption</A> to arbitrary gateways. In these cases, you - can accept UDP 500 IKE packets from anywhere, then use the<A href="#updown"> - updown</A> script feature of<A href="manpage.d/ipsec_pluto.8.html"> - pluto(8)</A> to dynamically adjust firewalling for each negotiated - tunnel.</P> -<P>Firewall packet filtering does not much reduce the risk of a<A href="#DOS"> - denial of service attack</A> on FreeS/WAN. The firewall can drop - packets from unknown gateways, but KLIPS does that quite efficiently - anyway, so you gain little. The firewall cannot drop otherwise - legitmate packets that fail KLIPS authentication, so it cannot protect - against an attack designed to exhaust resources by making FreeS/WAN - perform many expensive authentication operations.</P> -<P>In summary, firewall filtering of IPsec packets from unknown gateways - is possible but not strictly necessary.</P> -<H2><A name="otherfilter">Other packet filters</A></H2> -<P>When the IPsec gateway is also acting as your firewall, other packet - filtering rules will be in play. In general, those are outside the - scope of this document. See our<A href="#firewall.linux"> Linux - firewall links</A> for information. There are a few types of packet, - however, which can affect the operation of FreeS/WAN or of diagnostic - tools commonly used with it. These are discussed below.</P> -<H3><A name="ICMP">ICMP filtering</A></H3> -<P><A href="#ICMP.gloss">ICMP</A> is the<STRONG> I</STRONG>nternet<STRONG> - C</STRONG>ontrol<STRONG> M</STRONG>essage<STRONG> P</STRONG>rotocol. It - is used for messages between IP implementations themselves, whereas IP - used is used between the clients of those implementations. ICMP is, - unsurprisingly, used for control messages. For example, it is used to - notify a sender that a desination is not reachable, or to tell a router - to reroute certain packets elsewhere.</P> -<P>ICMP handling is tricky for firewalls.</P> -<UL> -<LI>You definitely want some ICMP messages to get through; things won't - work without them. For example, your clients need to know if some - destination they ask for is unreachable.</LI> -<LI>On the other hand, you do equally definitely do not want untrusted - folk sending arbitrary control messages to your machines. Imagine what - someone moderately clever and moderately malicious could do to you, - given control of your network's routing.</LI> -</UL> -<P>ICMP does not use ports. Messages are distinguished by a "message - type" field and, for some types, by an additional "code" field. The - definitive list of types and codes is on the<A href="http://www.iana.org"> - IANA</A> site.</P> -<P>One expert uses this definition for ICMP message types to be dropped - at the firewall.</P> -<PRE># ICMP types which lack socially redeeming value. -# 5 Redirect -# 9 Router Advertisement -# 10 Router Selection -# 15 Information Request -# 16 Information Reply -# 17 Address Mask Request -# 18 Address Mask Reply - -badicmp='5 9 10 15 16 17 18'</PRE> -<P>A more conservative approach would be to make a list of allowed types - and drop everything else.</P> -<P>Whichever way you do it, your ICMP filtering rules on a FreeS/WAN - gateway should allow at least the following ICMP packet types:</P> -<DL> -<DT>echo (type 8)</DT> -<DD></DD> -<DT>echo reply (type 0)</DT> -<DD>These are used by ping(1). We recommend allowing both types through - the tunnel and to or from your gateway's external interface, since - ping(1) is an essential testing tool. -<P>It is fairly common for firewalls to drop ICMP echo packets addressed - to machines behind the firewall. If that is your policy, please create - an exception for such packets arriving via an IPsec tunnel, at least - during intial testing of those tunnels.</P> -</DD> -<DT>destination unreachable (type 3)</DT> -<DD>This is used, with code 4 (Fragmentation Needed and Don't Fragment - was Set) in the code field, to control<A href="#pathMTU"> path MTU - discovery</A>. Since IPsec processing adds headers, enlarges packets - and may cause fragmentation, an IPsec gateway should be able to send - and receive these ICMP messages<STRONG> on both inside and outside - interfaces</STRONG>.</DD> -</DL> -<H3><A name="traceroute">UDP packets for traceroute</A></H3> -<P>The traceroute(1) utility uses UDP port numbers from 33434 to - approximately 33633. Generally, these should be allowed through for - troubleshooting.</P> -<P>Some firewalls drop these packets to prevent outsiders exploring the - protected network with traceroute(1). If that is your policy, consider - creating an exception for such packets arriving via an IPsec tunnel, at - least during intial testing of those tunnels.</P> -<H3><A name="l2tp">UDP for L2TP</A></H3> -<P> Windows 2000 does, and products designed for compatibility with it - may, build<A href="#l2tp"> L2TP</A> tunnels over IPsec connections.</P> -<P>For this to work, you must allow UDP protocol 1701 packets coming out - of your tunnels to continue to their destination. You can, and probably - should, block such packets to or from your external interfaces, but - allow them from<VAR> ipsec0</VAR>.</P> -<P>See also our Windows 2000<A href="interop.html#win2k"> interoperation - discussion</A>.</P> -<H2><A name="packets">How it all works: IPsec packet details</A></H2> -<P>IPsec uses three main types of packet:</P> -<DL> -<DT><A href="#IKE">IKE</A> uses<STRONG> the UDP protocol and port 500</STRONG> -.</DT> -<DD>Unless you are using only (less secure, not recommended) manual - keying, you need IKE to negotiate connection parameters, acceptable - algorithms, key sizes and key setup. IKE handles everything required to - set up, rekey, repair or tear down IPsec connections.</DD> -<DT><A href="#ESP">ESP</A> is<STRONG> protocol number 50</STRONG></DT> -<DD>This is required for encrypted connections.</DD> -<DT><A href="#AH">AH</A> is<STRONG> protocol number 51</STRONG></DT> -<DD>This can be used where only authentication, not encryption, is - required.</DD> -</DL> -<P>All of those packets should have appropriate IPsec gateway addresses - in both the to and from IP header fields. Firewall rules can check this - if you wish, though it is not strictly necessary. This is discussed in - more detail<A href="#unknowngate"> later</A>.</P> -<P>IPsec processing of incoming packets authenticates them then removes - the ESP or AH header and decrypts if necessary. Successful processing - exposes an inner packet which is then delivered back to the firewall - machinery, marked as having arrived on an<VAR> ipsec[0-3]</VAR> - interface. Firewall rules can use that interface label to distinguish - these packets from unencrypted packets which are labelled with the - physical interface they arrived on (or perhaps with a non-IPsec virtual - interface such as<VAR> ppp0</VAR>).</P> -<P>One of our users sent a mailing list message with a<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/12/msg00006.html"> - diagram</A> of the packet flow.</P> -<H3><A name="noport">ESP and AH do not have ports</A></H3> -<P>Some protocols, such as TCP and UDP, have the notion of ports. Others - protocols, including ESP and AH, do not. Quite a few IPsec newcomers - have become confused on this point. There are no ports<EM> in</EM> the - ESP or AH protocols, and no ports used<EM> for</EM> them. For these - protocols,<EM> the idea of ports is completely irrelevant</EM>.</P> -<H3><A name="header">Header layout</A></H3> -<P>The protocol numbers for ESP or AH are used in the 'next header' - field of the IP header. On most non-IPsec packets, that field would - have one of:</P> -<UL> -<LI>1 for ICMP</LI> -<LI>4 for IP-in-IP encapsulation</LI> -<LI>6 for TCP</LI> -<LI>17 for UDP</LI> -<LI>... or one of about 100 other possibilities listed by<A href="http://www.iana.org"> - IANA</A></LI> -</UL> -<P>Each header in the sequence tells what the next header will be. IPsec - adds headers for ESP or AH near the beginning of the sequence. The - original headers are kept and the 'next header' fields adjusted so that - all headers can be correctly interpreted.</P> -<P>For example, using<STRONG> [</STRONG><STRONG> ]</STRONG> to indicate - data protected by ESP and unintelligible to an eavesdropper between the - gateways:</P> -<UL> -<LI>a simple packet might have only IP and TCP headers with: -<UL> -<LI>IP header says next header --> TCP</LI> -<LI>TCP header port number --> which process to send data to</LI> -<LI>data</LI> -</UL> -</LI> -<LI>with ESP<A href="#transport"> transport mode</A> encapsulation, that - packet would have: -<UL> -<LI>IP header says next header --> ESP</LI> -<LI>ESP header<STRONG> [</STRONG> says next --> TCP</LI> -<LI>TCP header port number --> which process to send data to</LI> -<LI>data<STRONG> ]</STRONG></LI> -</UL> - Note that the IP header is outside ESP protection, visible to an - attacker, and that the final destination must be the gateway.</LI> -<LI>with ESP in<A href="#tunnel"> tunnel mode</A>, we might have: -<UL> -<LI>IP header says next header --> ESP</LI> -<LI>ESP header<STRONG> [</STRONG> says next --> IP</LI> -<LI>IP header says next header --> TCP</LI> -<LI>TCP header port number --> which process to send data to</LI> -<LI>data<STRONG> ]</STRONG></LI> -</UL> - Here the inner IP header is protected by ESP, unreadable by an - attacker. Also, the inner header can have a different IP address than - the outer IP header, so the decrypted packet can be routed from the - IPsec gateway to a final destination which may be another machine.</LI> -</UL> -<P>Part of the ESP header itself is encrypted, which is why the<STRONG> - [</STRONG> indicating protected data appears in the middle of some - lines above. The next header field of the ESP header is protected. This - makes<A href="#traffic"> traffic analysis</A> more difficult. The next - header field would tell an eavesdropper whether your packet was UDP to - the gateway, TCP to the gateway, or encapsulated IP. It is better not - to give this information away. A clever attacker may deduce some of it - from the pattern of packet sizes and timings, but we need not make it - easy.</P> -<P>IPsec allows various combinations of these to match local policies, - including combinations that use both AH and ESP headers or that nest - multiple copies of these headers.</P> -<P>For example, suppose my employer has an IPsec VPN running between two - offices so all packets travelling between the gateways for those - offices are encrypted. If gateway policies allow it (The admins could - block UDP 500 and protocols 50 and 51 to disallow it), I can build an - IPsec tunnel from my desktop to a machine in some remote office. Those - packets will have one ESP header throughout their life, for my - end-to-end tunnel. For part of the route, however, they will also have - another ESP layer for the corporate VPN's encapsulation. The whole - header scheme for a packet on the Internet might be:</P> -<UL> -<LI>IP header (with gateway address) says next header --> ESP</LI> -<LI>ESP header<STRONG> [</STRONG> says next --> IP</LI> -<LI>IP header (with receiving machine address) says next header --> ESP</LI> -<LI>ESP header<STRONG> [</STRONG> says next --> TCP</LI> -<LI>TCP header port number --> which process to send data to</LI> -<LI>data<STRONG> ]]</STRONG></LI> -</UL> -<P>The first ESP (outermost) header is for the corporate VPN. The inner - ESP header is for the secure machine-to-machine link.</P> -<H3><A name="dhr">DHR on the updown script</A></H3> -<P>Here are some mailing list comments from<A href="manpage.d/ipsec_pluto.8.html"> - pluto(8)</A> developer Hugh Redelmeier on an earlier draft of this - document:</P> -<PRE>There are many important things left out - -- firewalling is important but must reflect (implement) policy. Since - policy isn't the same for all our customers, and we're not experts, - we should concentrate on FW and MASQ interactions with FreeS/WAN. - -- we need a diagram to show packet flow WITHIN ONE MACHINE, assuming - IKE, IPsec, FW, and MASQ are all done on that machine. The flow is - obvious if the components are run on different machines (trace the - cables). - - IKE input: - + packet appears on public IF, as UDP port 500 - + input firewalling rules are applied (may discard) - + Pluto sees the packet. - - IKE output: - + Pluto generates the packet & writes to public IF, UDP port 500 - + output firewalling rules are applied (may discard) - + packet sent out public IF - - IPsec input, with encapsulated packet, outer destination of this host: - + packet appears on public IF, protocol 50 or 51. If this - packet is the result of decapsulation, it will appear - instead on the paired ipsec IF. - + input firewalling rules are applied (but packet is opaque) - + KLIPS decapsulates it, writes result to paired ipsec IF - + input firewalling rules are applied to resulting packet - as input on ipsec IF - + if the destination of the packet is this machine, the - packet is passed on to the appropriate protocol handler. - If the original packet was encapsulated more than once - and the new outer destination is this machine, that - handler will be KLIPS. - + otherwise: - * routing is done for the resulting packet. This may well - direct it into KLIPS for encoding or encrypting. What - happens then is described elsewhere. - * forwarding firewalling rules are applied - * output firewalling rules are applied - * the packet is sent where routing specified - - IPsec input, with encapsulated packet, outer destination of another host: - + packet appears on some IF, protocol 50 or 51 - + input firewalling rules are applied (but packet is opaque) - + routing selects where to send the packet - + forwarding firewalling rules are applied (but packet is opaque) - + packet forwarded, still encapsulated - - IPsec output, from this host or from a client: - + if from a client, input firewalling rules are applied as the - packet arrives on the private IF - + routing directs the packet to an ipsec IF (this is how the - system decides KLIPS processing is required) - + if from a client, forwarding firewalling rules are applied - + KLIPS eroute mechanism matches the source and destination - to registered eroutes, yielding a SPI group. This dictates - processing, and where the resulting packet is to be sent - (the destinations SG and the nexthop). - + output firewalling is not applied to the resulting - encapsulated packet - -- Until quite recently, KLIPS would double encapsulate packets that - didn't strictly need to be. Firewalling should be prepared for - those packets showing up as ESP and AH protocol input packets on - an ipsec IF. - -- MASQ processing seems to be done as if it were part of the - forwarding firewall processing (this should be verified). - -- If a firewall is being used, it is likely the case that it needs to - be adjusted whenever IPsec SAs are added or removed. Pluto invokes - a script to do this (and to adjust routing) at suitable times. The - default script is only suitable for ipfwadm-managed firewalls. Under - LINUX 2.2.x kernels, ipchains can be managed by ipfwadm (emulation), - but ipchains more powerful if manipulated using the ipchains command. - In this case, a custom updown script must be used. - - We think that the flexibility of ipchains precludes us supplying an - updown script that would be widely appropriate.</PRE> -<HR> -<H1><A NAME="trouble"></A>Linux FreeS/WAN Troubleshooting Guide</H1> -<H2><A NAME="overview"></A>Overview</H2> -<P> This document covers several general places where you might have a - problem:</P> -<OL> -<LI><A HREF="#install">During install</A>.</LI> -<LI><A HREF="#negotiation">During the negotiation process</A>.</LI> -<LI><A HREF="#use">Using an established connection</A>.</LI> -</OL> -<P>This document also contains<A HREF="#notes"> notes</A> which expand - on points made in these sections, and tips for<A HREF="#prob.report"> - problem reporting</A>. If the other end of your connection is not - FreeS/WAN, you'll also want to read our<A HREF="interop.html#interop.problem"> - interoperation</A> document.</P> -<H2><A NAME="install"></A>1. During Install</H2> -<H3><A NAME="8_2_1">1.1 RPM install gotchas</A></H3> -<P>With the RPM method:</P> -<UL> -<LI>Be sure you have installed both the userland tools and the kernel - components. One will not work without the other. For example, when - using FreeS/WAN-produced RPMs for our 2.04 release, you need both: -<PRE> freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm - freeswan-module-2.04_2.4.20_20.9-0.i386.rpm -</PRE> -</LI> -</UL> -<H3><A NAME="8_2_2">1.2 Problems installing from source</A></H3> -<P>When installing from source, you may find these problems:</P> -<UL> -<LI>Missing library. See<A HREF="#gmp.h_missing"> this</A> FAQ.</LI> -<LI>Missing utilities required for compile. See this<A HREF="install.html#tool.lib"> - checklist</A>.</LI> -<LI>Kernel version incompatibility. See<A HREF="#k.versions"> this</A> - FAQ.</LI> -<LI>Another compile problem. Find information in the out.* files, ie. - out.kpatch, out.kbuild, created at compile time in the top-level Linux - FreeS/WAN directory. Error messages generated by KLIPS during the boot - sequence are accessible with the<VAR> dmesg</VAR> command. -<BR> Check the list archives and the List in Brief to see if this is a - known issue. If it is not, report it to the bugs list as described in - our<A HREF="#prob.report"> problem reporting</A> section. In some - cases, you may be asked to provide debugging information using gdb; - details<A HREF="#gdb"> below</A>.</LI> -<LI>If your kernel compiles but you fail to install your new - FreeS/WAN-enabled kernel, review the sections on<A HREF="install.html#newk"> - installing the patched kernel</A>, and<A HREF="#testinstall"> testing</A> - to see if install succeeded.</LI> -</UL> -<H3><A NAME="install.check"></A>1.3 Install checks</H3> -<P><VAR>ipsec verify</VAR> checks a number of FreeS/WAN essentials. Here - are some hints on what do to when your system doesn't check out:</P> -<P></P> -<TABLE border="1"> -<TR><TD><STRONG>Problem</STRONG></TD><TD><STRONG>Status</STRONG></TD><TD> -<STRONG>Action</STRONG></TD></TR> -<TR><TD><VAR>ipsec</VAR> not on-path</TD><TD> </TD><TD> -<P>Add<VAR> /usr/local/sbin</VAR> to your PATH.</P> -</TD></TR> -<TR><TD>Missing KLIPS support</TD><TD><FONT COLOR="#FF0000">critical</FONT> -</TD><TD>See<A HREF="#noKLIPS"> this FAQ.</A></TD></TR> -<TR><TD>No RSA private key</TD><TD> </TD><TD> -<P>Follow<A HREF="install.html#genrsakey"> these instructions</A> to - create an RSA key pair for your host. RSA keys are:</P> -<UL> -<LI>required for opportunistic encryption, and</LI> -<LI>our preferred method to authenticate pre-configured connections.</LI> -</UL> -</TD></TR> -<TR><TD><VAR>pluto</VAR> not running</TD><TD><FONT COLOR="#FF0000"> -critical</FONT></TD><TD> -<PRE>service ipsec start</PRE> -</TD></TR> -<TR><TD>No port 500 hole</TD><TD><FONT COLOR="#FF0000">critical</FONT></TD><TD> -Open port 500 for IKE negotiation.</TD></TR> -<TR><TD>Port 500 check N/A</TD><TD> </TD><TD>Check that port 500 is open - for IKE negotiation.</TD></TR> -<TR><TD>Failed DNS checks</TD><TD> </TD><TD>Opportunistic encryption - requires information from DNS. To set this up, see<A HREF="#opp.setup"> - our instructions</A>.</TD></TR> -<TR><TD>No public IP address</TD><TD> </TD><TD>Check that the interface - which you want to protect with IPSec is up and running.</TD></TR> -</TABLE> -<H3><A NAME="oe.trouble"></A>1.3 Troubleshooting OE</H3> -<P>OE should work with no local configuration, if you have posted DNS - TXT records according to the instructions in our<A HREF="quickstart.html"> - quickstart guide</A>. If you encounter trouble, try these hints. We - welcome additional hints via the<A HREF="mail.html"> users' mailing - list</A>.</P> -<TABLE border="1"> -<TR><TD><STRONG>Symptom</STRONG></TD><TD><STRONG>Problem</STRONG></TD><TD> -<STRONG>Action</STRONG></TD></TR> -<TR><TD> You're running FreeS/WAN 2.01 (or later), and initiating a - connection to FreeS/WAN 2.00 (or earlier). In your logs, you see a - message like: -<PRE>no RSA public key known for '192.0.2.13'; -DNS search for KEY failed (no KEY record -for 13.2.0.192.in-addr.arpa.)</PRE> - The older FreeS/WAN logs no error.</TD><TD><A NAME="oe.trouble.flagday"> -</A> A protocol level incompatibility between 2.01 (or later) and 2.00 - (or earlier) causes this error. It occurs when a FreeS/WAN 2.01 (or - later) box for which no KEY record is posted attempts to initiate an OE - connection to older FreeS/WAN versions (2.00 and earlier). Note that - older versions can initiate to newer versions without this error.</TD><TD> -If you control the peer host, upgrade its FreeS/WAN to 2.01 (or later), - and post new style TXT records for it. If not, but if you know its - sysadmin, perhaps a quick note is in order. If neither option is - possible, you can ease the transition by posting an old style KEY - record (created with a command like "ipsec showhostkey --key") to the - reverse map for the FreeS/WAN 2.01 (or later) box.</TD></TR> -<TR><TD>OE host is very slow to contact other hosts.</TD><TD>Slow DNS - service while running OE.</TD><TD>It's a good idea to run a caching DNS - server on your OE host, as outlined in<A HREF="http://lists.freeswan.org/pipermail/design/2003-January/004205.html"> - this mailing list message</A>. If your DNS servers are elsewhere, put - their IPs in the<VAR> clear</VAR> policy group, and re-read groups with -<PRE>ipsec auto --rereadgroups</PRE> -</TD></TR> -<TR><TD> -<PRE>Can't Opportunistically initiate for -192.0.2.2 to 192.0.2.3: no TXT record -for 13.2.0.192.in-addr.arpa.</PRE> -</TD><TD>Peer is not set up for OE.</TD><TD> -<P>None. Plenty of hosts on the Internet do not run OE. If, however, you - have set OE up on that peer, this may indicate that you need to wait up - to 48 hours for its DNS records to propagate.</P> -</TD></TR> -<TR><TD><VAR>ipsec verify</VAR> does not find DNS records: -<PRE>... -Looking for TXT in forward map: - xy.example.com...[FAILED] -Looking for TXT in reverse map...[FAILED] -...</PRE> - You also experience authentication failure: -<BR> -<PRE>Possible authentication failure: -no acceptable response to our -first encrypted message</PRE> -</TD><TD>DNS records are not posted or have not propagated.</TD><TD>Did - you post the DNS records necessary for OE? If not, do so using the - instructions in our<A HREF="#quickstart"> quickstart guide</A>. If so, - wait up to 48 hours for the DNS records to propagate.</TD></TR> -<TR><TD><VAR>ipsec verify</VAR> does not find DNS records, and you - experience authentication failure.</TD><TD>For iOE, your ID does not - match location of forward DNS record.</TD><TD>In<VAR> config setup</VAR> -, change<VAR> myid=</VAR> to match the forward DNS where you posted the - record. Restart FreeS/WAN. For reference, see our<A HREF="#opp.client"> - iOE instructions</A>.</TD></TR> -<TR><TD><VAR>ipsec verify</VAR> finds DNS records, yet there is still - authentication failure. ( ? )</TD><TD>DNS records are malformed.</TD><TD> -Re-create the records and send new copies to your DNS administrator.</TD> -</TR> -<TR><TD><VAR>ipsec verify</VAR> finds DNS records, yet there is still - authentication failure. ( ? )</TD><TD>DNS records show different keys - for a gateway vs. its subnet hosts.</TD><TD>All TXT records for boxes - protected by an OE gateway must contain the gateway's public key. - Re-create and re-post any incorrect records using<A HREF="#opp.incoming"> - these instructions</A>.</TD></TR> -<TR><TD>OE gateway loses connectivity to its subnet. The gateway's - routing table shows routes to the subnet through IPsec interfaces.</TD><TD> -The subnet is part of the<VAR> private</VAR> or<VAR> block</VAR> policy - group on the gateway.</TD><TD>Remove the subnet from the group, and - reread groups with -<PRE>ipsec auto --rereadgroups</PRE> -</TD></TR> -<TR><TD>OE does not work to hosts on the local LAN.</TD><TD>This is a - known issue.</TD><TD>See<A HREF="opportunism.known-issues"> this list</A> - of known issues with OE.</TD></TR> -<TR><TD>FreeS/WAN does not seem to be executing your default policy. In - your logs, you see a message like: -<PRE>/etc/ipsec.d/policies/iprivate-or-clear" -line 14: subnet "0.0.0.0/0", -source 192.0.2.13/32, -already "private-or-clear"</PRE> -</TD><TD><A HREF="#fullnet">Fullnet</A> in a policy group file defines - your default policy. Fullnet should normally be present in only one - policy group file. The fine print: you can have two default policies - defined so long as they protect different local endpoints (e.g. the - FreeS/WAN gateway and a subnet).</TD><TD> Find all policies which - contain fullnet with: -<BR> -<PRE>grep -F 0.0.0.0/0 /etc/ipsec.d/policies/*</PRE> - then remove the unwanted occurrence(s).</TD></TR> -</TABLE> -<H2><A NAME="negotiation"></A>2. During Negotiation</H2> -<P>When you fail to bring up a tunnel, you'll need to find out:</P> -<UL> -<LI><A HREF="#state">what your connection state is,</A> and often</LI> -<LI><A HREF="#find.pluto.error">an error message</A>.</LI> -</UL> -<P>before you can<A HREF="#interpret.pluto.error"> diagnose your problem</A> -.</P> -<H3><A NAME="state"></A>2.1 Determine Connection State</H3> -<H4><A NAME="8_3_1_1">Finding current state</A></H4> -<P>You can see connection states (STATE_MAIN_I1 and so on) when you - bring up a connection on the command line. If you have missed this, or - brought up your connection automatically, use:</P> -<PRE>ipsec auto --status</PRE> -<P>The most relevant state is the last one reached.</P> -<H4><A NAME="8_3_1_2"><VAR>What's this supposed to look like?</VAR></A></H4> -<P>Negotiations should proceed though various states, in the processes - of:</P> -<OL> -<LI>IKE negotiations (aka Phase 1, Main Mode, STATE_MAIN_*)</LI> -<LI>IPSEC negotiations (aka Phase 2, Quick Mode, STATE_QUICK_*)</LI> -</OL> -<P>These are done and a connection is established when you see messages - like:</P> -<PRE> 000 #21: "myconn" STATE_MAIN_I4 (ISAKMP SA established)... - 000 #2: "myconn" STATE_QUICK_I2 (sent QI2, IPsec SA established)...</PRE> -<P> Look for the key phrases are "ISAKMP SA established" and "IPSec SA - established", with the relevant connection name. Often, this happens at - STATE_MAIN_I4 and STATE_QUICK_I2, respectively.</P> -<P><VAR>ipsec auto --status</VAR> will tell you what states<STRONG> have - been achieved</STRONG>, rather than the current state. Since - determining the current state is rather more difficult to do, current - state information is not available from Linux FreeS/WAN. If you are - actively bringing a connection up, the status report's last states for - that connection likely reflect its current state. Beware, though, of - the case where a connection was correctly brought up but is now downed: - Linux FreeS/WAN will not notice this until it attempts to rekey. - Meanwhile, the last known state indicates that the connection has been - established.</P> -<P>If your connection is stuck at STATE_MAIN_I1, skip straight to<A HREF="#ikepath"> - here</A>.</P> -<H3><A NAME="find.pluto.error"></A>2.2 Finding error text</H3> -<P>Solving most errors will require you to find verbose error text, - either on the command line or in the logs.</P> -<H4><A NAME="8_3_2_1">Verbose start for more information</A></H4> -<P> Note that you can get more detail from<VAR> ipsec auto</VAR> using - the --verbose flag:</P> -<PRE STYLE="margin-bottom: 0.2in"> ipsec auto --verbose --up west-east</PRE> -<P> More complete information can be gleaned from the<A HREF="#logusage"> - log files</A>.</P> -<H4><A NAME="8_3_2_2">Debug levels count</A></H4> -<P>The amount of description you'll get here depends on ipsec.conf debug - settings,<VAR> klipsdebug</VAR>= and<VAR> plutodebug</VAR>=. When - troubleshooting, set at least one of these to<VAR> all</VAR>, and when - done, reset it to<VAR> none</VAR> so your logs don't fill up. Note that - you must have enabled the<VAR> klipsdebug</VAR><A HREF="install.html#allbut"> - compile-time option</A> for the<VAR> klipsdebug</VAR> configuration - switch to work.</P> -<P>For negotiation problems<VAR> plutodebug</VAR> is most relevant.<VAR> - klipsdebug</VAR> applies mainly to attempts to use an - already-established connection. See also<A HREF="#parts"> this</A> - description of the division of duties within Linux FreeS/WAN.</P> -<P>After raising your debug levels, restart Linux FreeS/WAN to ensure - that ipsec.conf is reread, then recreate the error to generate verbose - logs.</P> -<H4><A NAME="8_3_2_3"><VAR>ipsec barf</VAR> for lots of debugging - information</A></H4> -<P><A HREF="manpage.d/ipsec_barf.8.html"><VAR> ipsec barf (8)</VAR></A> - collects a bunch of useful debugging information, including these logs - Use the command</P> -<PRE> - ipsec barf > barf.west -</PRE> -<P>to generate one.</P> -<H4><A NAME="8_3_2_4">Find the error</A></H4> -<P>Search out the failure point in your logs. Are there a handful of - lines which succinctly describe how things are going wrong or contrary - to your expectation? Sometimes the failure point is not immediately - obvious: Linux FreeS/WAN's errors are usually not marked "Error". Have - a look in the<A HREF="faq.html"> FAQ</A> for what some common failures - look like.</P> -<P>Tip: problems snowball. Focus your efforts on the first problem, - which is likely to be the cause of later errors.</P> -<H4><A NAME="8_3_2_5">Play both sides</A></H4> -<P>Also find error text on the peer IPSec box. This gives you two - perspectives on the same failure.</P> -<P>At times you will require information which only one side has. The - peer can merely indicate the presence of an error, and its approximate - point in the negotiations. If one side keeps retrying, it may be - because there is a show stopper on the other side. Have a look at the - other side and figure out what it doesn't like.</P> -<P>If the other end is not Linux FreeS/WAN, the principle is the same: - replicate the error with its most verbose logging on, and capture the - output to a file.</P> -<H3><A NAME="interpret.pluto.error"></A>2.3 Interpreting a Negotiation - Error</H3> -<H4><A NAME="ikepath"></A>Connection stuck at STATE_MAIN_I1</H4> -<P>This error commonly happens because IKE (port 500) packets, needed to - negotiate an IPSec connection, cannot travel freely between your IPSec - gateways. See<A HREF="#packets"> our firewall document</A> for details.</P> -<H4><A NAME="8_3_3_2">Other errors</A></H4> -<P>Other errors require a bit more digging. Use the following resources:</P> -<UL> -<LI><A HREF="faq.html">the FAQ</A> . Since this document is constantly - updated, the snapshot's FAQ may have a new entry relevant to your - problem.</LI> -<LI>our<A HREF="background.html"> background document</A> . Special - considerations which, while not central to Linux FreeS/WAN, are often - tripped over. Includes problems with<A href="#MTU.trouble"> packet - fragmentation</A>, and considerations for testing opportunism.</LI> -<LI>the<A HREF="#lists"> list archives</A>. Each of the searchable - archives works differently, so it's worth checking each. Use a search - term which is generic, but identifies your error, for example "No - connection is known for". -<BR> Often, you will find that your question has been answered in the - past. Finding an archived answer is quicker than asking the list. You - may, however, find similar questions without answers. If you do, send - their URLs to the list with your trouble report. The additional - examples may help the list tech support person find your answer.</LI> -<LI>Look into the code where the error is being generated. The pluto - code is nicely documented with comments and meaningful variable names.</LI> -</UL> -<P>If you have failed to solve your problem with the help of these - resources, send a detailed problem report to the users list, following - these<A HREF="#prob.report"> guidelines</A>.</P> -<H2><A NAME="use"></A>3. Using a Connection</H2> -<H3><A NAME="8_4_1">3.1 Orienting yourself</A></H3> -<H4><A NAME="8_4_1_1"><VAR>How do I know if it works?</VAR></A></H4> -<P>Test your connection by sending packets through it. The simplest way - to do this is with ping, but the ping needs to<STRONG> test the correct - tunnel.</STRONG> See<A HREF="#testgates"> this example scenario</A> if - you don't understand this.</P> -<P></P> -<P>If your ping returns, test any other connections you've brought u all - check out, great. You may wish to<A HREF="#bigpacket"> test with large - packets</A> for MTU problems.</P> -<H4><A NAME="8_4_1_2"><VAR>ipsec barf</VAR> is useful again</A></H4> -<P>If your ping fails to return, generate an ipsec barf debugging report - on each IPSec gateway. On a non-Linux FreeS/WAN implementation, gather - equivalent information. Use this, and the tips in the next sections, to - troubleshoot. Are you sure that both endpoints are capable of hearing - and responding to ping?</P> -<H3><A NAME="8_4_2">3.2 Those pesky configuration errors</A></H3> -<P>IPSec may be dropping your ping packets since they do not belong in - the tunnels you have constructed:</P> -<UL> -<LI>Your ping may not test the tunnel you intend to test. For details, - see our<A HREF="#cantping"> "I can't ping"</A> FAQ.</LI> -<LI> Alternately, you may have a configuration error. For example, you - may have configured one of the four possible tunnels between two - gateways, but not the one required to secure the important traffic - you're now testing. In this case, add and start the tunnel, and try - again.</LI> -</UL> -<P>In either case, you will often see a message like:</P> -<PRE>klipsdebug... no eroute</PRE> -<P>which we discuss in<A HREF="#no_eroute"> this FAQ</A>.</P> -<P>Note:</P> -<UL> -<LI><A HREF="#NAT.gloss">Network Address Translation (NAT)</A> and<A HREF="#masq"> - IP masquerade</A> may have an effect on which tunnels you need to - configure.</LI> -<LI>When testing a tunnel that protects a multi-node subnet, try several - subnet nodes as ping targets, in case one node is routing incorrectly.</LI> -</UL> -<H3><A NAME="route.firewall"></A>3.3 Check Routing and Firewalling</H3> -<P>If you've confirmed your configuration assumptions, the problem is - almost certainly with routing or firewalling. Isolate the problem using - interface statistics, firewall statistics, or a packet sniffer.</P> -<H4><A NAME="8_4_3_1">Background:</A></H4> -<UL> -<LI>Linux FreeS/WAN supplies all the special routing it needs; you need - only route packets out through your IPSec gateway. Verify that on the<VAR> - subnetted</VAR> machines you are using for your ping-test, your routing - is as expected. I have seen a tunnel "fail" because the subnet machine - sending packets out an alternate gateway (not our IPSec gateway) on - their return path.</LI> -<LI>Linux FreeS/WAN requires particular<A HREF="firewall.html"> - firewalling considerations</A>. Check the firewall rules on your IPSec - gateways and ensure that they allow IPSec traffic through. Be sure that - no other machine - for example a router between the gateways - is - blocking your IPSec packets.</LI> -</UL> -<H4><A NAME="ifconfig"></A>View Interface and Firewall Statistics</H4> -<P>Interface reports and firewall statistics can help you track down - lost packets at a glance. Check any firewall statistics you may be - keeping on your IPSec gateways, for dropped packets.</P> -<P><STRONG>Tip</STRONG>: You can take a snapshot of the packets - processed by your firewall with:</P> -<PRE> iptables -L -n -v</PRE> -<P>You can get creative with "diff" to find out what happens to a - particular packet during transmission.</P> -<P>Both<VAR> cat /proc/net/dev</VAR> and<VAR> ifconfig</VAR> display - interface statistics, and both are included in<VAR> ipsec barf</VAR>. - Use either to check if any interface has dropped packets. If you find - that one has, test whether this is related to your ping. While you ping - continuously, print that interface's statistics several times. Does its - drop count increase in proportion to the ping? If so, check why the - packets are dropped there.</P> -<P>To do this, look at the firewall rules that apply to that interface. - If the interface is an IPSec interface, more information may be - available in the log. Grep for the word "drop" in a log which was - created with<VAR> klipsdebug=all</VAR> as the error happened.</P> -<P>See also this<A HREF="#ifconfig1"> discussion</A> on interpreting<VAR> - ifconfig</VAR> statistics.</P> -<H3><A NAME="sniff"></A>3.4 When in doubt, sniff it out</H3> -<P>If you have checked configuration assumptions, routing, and firewall - rules, and your interface statistics yield no clue, it remains for you - to investigate the mystery of the lost packet by the most thorough - method: with a packet sniffer (providing, of course, that this is legal - where you are working).</P> -<P>In order to detect packets on the ipsec virtual interfaces, you will - need an up-to-date sniffer (tcpdump, ethereal, ksnuffle) on your IPSec - gateway machines. You may also find it useful to sniff the ping - endpoints.</P> -<H4><A NAME="8_4_4_1">Anticipate your packets' path</A></H4> -<P>Ping, and examine each interface along the projected path, checking - for your ping's arrival. If it doesn't get to the the next stop, you - have narrowed down where to look for it. In this way, you can isolate a - problem area, and narrow your troubleshooting focus.</P> -<P>Within a machine running Linux FreeS/WAN, this<A HREF="#packets"> - packet flow diagram</A> will help you anticipate a packet's path.</P> -<P>Note that:</P> -<UL> -<LI> from the perspective of the tunneled packet, the entire tunnel is - one hop. That's explained in<A HREF="#no_trace"> this</A> FAQ.</LI> -<LI> an encapsulated IPSec packet will look different, when sniffed, - from the plaintext packet which generated it. You can see plaintext - packets entering an IPSec interface and the resulting cyphertext - packets as they emerge from the corresponding physical interface.</LI> -</UL> -<P>Once you isolate where the packet is lost, take a closer look at - firewall rules, routing and configuration assumptions as they affect - that specific area. If the packet is lost on an IPSec gateway, comb - through<VAR> klipsdebug</VAR> output for anomalies.</P> -<P>If the packet goes through both gateways successfully and reaches the - ping target, but does not return, suspect routing. Check that the ping - target routes packets back to the IPSec gateway.</P> -<H3><A NAME="find.use.error"></A>3.5 Check your logs</H3> -<P>Here, too, log information can be useful. Start with the<A HREF="#find.pluto.error"> - guidelines above</A>.</P> -<P>For connection use problems, set<VAR> klipsdebug=all</VAR>. Note that - you must have enabled the<VAR> klipsdebug</VAR><A HREF="install.html#allbut"> - compile-time option</A> to do this. Restart Linux FreeS/WAN so that it - rereads<VAR> ipsec.conf</VAR>, then recreate the error condition. When - searching through<VAR> klipsdebug</VAR> data, look especially for the - keywords "drop" (as in dropped packets) and "error".</P> -<P>Often the problem with connection use is not software error, but - rather that the software is behaving contrary to expectation.</P> -<H4><A NAME="interpret.use.error"></A>Interpreting log text</H4> -<P>To interpret the Linux FreeS/WAN log text you've found, use the same - resources as indicated for troubleshooting connection negotiation:<A HREF="faq.html"> - the FAQ</A> , our<A HREF="background.html"> background document</A>, - and the<A HREF="#lists"> list archives</A>. Looking in the KLIPS code - is only for the very brave.</P> -<P>If you are still stuck, send a<A HREF="#prob.report"> detailed - problem report</A> to the users' list.</P> -<H3><A NAME="bigpacket"></A>3.6 More testing for the truly thorough</H3> -<H4><A NAME="8_4_6_1">Large Packets</A></H4> -<P>If each of your connections passed the ping test, you may wish to - test by pinging with large packets (2000 bytes or larger). If it does - not return, suspect MTU issues, and see this<A HREF="#MTU.trouble"> - discussion</A>.</P> -<H4><A NAME="8_4_6_2">Stress Tests</A></H4> -<P>In most users' view, a simple ping test, and perhaps a large-packet - ping test suffice to indicate a working IPSec connection.</P> -<P>Some people might like to do additional stress tests prior to - production use. They may be interested in this<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/12/msg00224.html"> - testing protocol</A> we use at interoperation conferences, aka - "bakeoffs". We also have a<VAR> testing</VAR> directory that ships with - the release.</P> -<H2><A NAME="prob.report"></A>4. Problem Reporting</H2> -<H3><A NAME="8_5_1">4.1 How to ask for help</A></H3> -<P>Ask for troubleshooting help on the users' mailing list,<A HREF="mailto:users@lists.freeswan.org"> - users@lists.freeswan.org</A>. While sometimes an initial query with a - quick description of your intent and error will twig someone's memory - of a similar problem, it's often necessary to send a second mail with a - complete problem report.</P> -<P>When reporting problems to the mailing list(s), please include:</P> -<UL> -<LI>a brief description of the problem</LI> -<LI>if it's a compile problem, the actual output from make, showing the - problem. Try to edit it down to only the relevant part, but when in - doubt, be as complete as you can. If it's a kernel compile problem, any - relevant out.* files</LI> -<LI>if it's a run-time problem, pointers to where we can find the - complete output from "ipsec barf" from BOTH ENDS (not just one of - them). Remember that it's common outside the US and Canada to pay for - download volume, so if you can't post barfs on the web and send the URL - to the mailing list, at least compress them with tar or gzip. -<BR> If you can, try to simplify the case that is causing the problem. - In particular, if you clear your logs, start FreeS/WAN with no other - connections running, cause the problem to happen, and then do<VAR> - ipsec barf</VAR> on both ends immediately, that gives the smallest and - least cluttered output.</LI> -<LI>any other error messages, complaints, etc. that you saw. Please send - the complete text of the messages, not just a summary.</LI> -<LI>what your network setup is. Include subnets, gateway addresses, etc. - A schematic diagram is a good format for this information.</LI> -<LI>exactly what you were trying to do with Linux FreeS/WAN, and exactly - what went wrong</LI> -<LI>a fix, if you have one. But remember, you are sending mail to people - all over the world; US residents and US citizens in particular, please - read doc/exportlaws.html before sending code -- even small bug fixes -- - to the list or to us.</LI> -<LI>When in doubt about whether to include some seemingly-trivial item - of information, include it. It is rare for problem reports to have too - much information, and common for them to have too little.</LI> -</UL> -<P>Here are some good general guidelines on bug reporting:<A href="http://tuxedo.org/~esr/faqs/smart-questions.html"> - How To Ask Questions The Smart Way</A> and<A href="http://www.chiark.greenend.org.uk/~sgtatham/bugs.html"> - How to Report Bugs Effectively</A>.</P> -<H3><A NAME="8_5_2">4.2 Where to ask</A></H3> -<P>To report a problem, send mail about it to the users' list. If you - are certain that you have found a bug, report it to the bugs list. If - you encounter a problem while doing your own coding on the Linux - FreeS/WAN codebase and think it is of interest to the design team, - notify the design list. When in doubt, default to the users' list. More - information about the mailing lists is found<A HREF="#lists"> here</A>.</P> -<P>For a number of reasons -- including export-control regulations - affecting almost any<STRONG> private</STRONG> discussion of encryption - software -- we prefer that problem reports and discussions go to the - lists, not directly to the team. Beware that the list goes worldwide; - US citizens, read this important information about your<A HREF="#exlaw"> - export laws</A>. If you're using this software, you really should be on - the lists. To get onto them, visit<A HREF="http://lists.freeswan.org/"> - lists.freeswan.org</A>.</P> -<P>If you do send private mail to our coders or want a private reply - from them, please make sure that the return address on your mail (From - or Reply-To header) is a valid one. They have more important things to - do than to unravel addresses that have been mangled in an attempt to - confuse spammers.</P> -<H2><A NAME="notes"></A>5. Additional Notes on Troubleshooting</H2> -<P>The following sections supplement the Guide:<A HREF="#system.info"> - information available on your system</A>;<A HREF="#testgates"> testing - between security gateways</A>;<A HREF="#ifconfig1"> ifconfig reports - for KLIPS debugging</A>;<A HREF="#gdb"> using GDB on Pluto</A>.</P> -<H3><A NAME="system.info"></A>5.1 Information available on your system</H3> -<H4><A NAME="logusage"></A>Logs used</H4> -<P>Linux FreeS/WAN logs to:</P> -<UL> -<LI>/var/log/secure (or, on Debian, /var/log/auth.log)</LI> -<LI>/var/log/messages</LI> -</UL> -<P>Check both places to get full information. If you find nothing, check - your<VAR> syslogd.conf(5)</VAR> to see where your /etc/syslog.conf or - equivalent is directing<VAR> authpriv</VAR> messages.</P> -<H4><A NAME="pages"></A>man pages provided</H4> -<DL> -<DT><A HREF="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</A></DT> -<DD> Manual page for IPSEC configuration file.</DD> -<DT><A HREF="manpage.d/ipsec.8.html"> ipsec(8)</A></DT> -<DD STYLE="margin-bottom: 0.2in"> Primary man page for ipsec utilities.</DD> -</DL> -<P> Other man pages are on<A HREF="manpages.html"> this list</A> and in</P> -<UL> -<LI>/usr/local/man/man3</LI> -<LI>/usr/local/man/man5</LI> -<LI>/usr/local/man/man8/ipsec_*</LI> -</UL> -<H4><A NAME="statusinfo"></A>Status information</H4> -<DL> -<DT>ipsec auto --status</DT> -<DD> Command to get status report from running system. Displays Pluto's - state. Includes the list of connections which are currently "added" to - Pluto's internal database; lists state objects reflecting ISAKMP and - IPsec SAs being negotiated or installed.</DD> -<DT> ipsec look</DT> -<DD> Brief status info.</DD> -<DT> ipsec barf</DT> -<DD STYLE="margin-bottom: 0.2in"> Copious debugging info.</DD> -</DL> -<H3><A NAME="testgates"></A> 5.2 Testing between security gateways</H3> -<P>Sometimes you need to test a subnet-subnet tunnel. This is a tunnel - between two security gateways, which protects traffic on behalf of the - subnets behind these gateways. On this network:</P> -<PRE> Sunset==========West------------------East=========Sunrise - IPSec gateway IPSec gateway - local net untrusted net local net</PRE> -<P> you might name this tunnel sunset-sunrise. You can test this tunnel - by having a machine behind one gateway ping a machine behind the other - gateway, but this is not always convenient or even possible.</P> -<P>Simply pinging one gateway from the other is not useful. Such a ping - does not normally go through the tunnel.<STRONG> The tunnel handles - traffic between the two protected subnets, not between the gateways</STRONG> - . Depending on the routing in place, a ping might</P> -<UL> -<LI>either succeed by finding an unencrypted route</LI> -<LI>or fail by finding no route. Packets without an IPSEC eroute are - discarded.</LI> -</UL> -<P><STRONG>Neither event tells you anything about the tunnel</STRONG>. - You can explicitly create an eroute to force such packets through the - tunnel, or you can create additional tunnels as described in our<A HREF="#multitunnel"> - configuration document</A>, but those may be unnecessary complications - in your situation.</P> -<P>The trick is to explicitly test between<STRONG> both gateways' - private-side IP addresses</STRONG>. Since the private-side interfaces - are on the protected subnets, the resulting packets do go via the - tunnel. Use either ping -I or traceroute -i, both of which allow you to - specify a source interface. (Note: unsupported on older Linuxes). The - same principles apply for a road warrior (or other) case where only one - end of your tunnel is a subnet.</P> -<H3><A NAME="ifconfig1"></A>5.3 ifconfig reports for KLIPS debugging</H3> -<P>When diagnosing problems using ifconfig statistics, you may wonder - what type of activity increments a particular counter for an ipsecN - device. Here's an index, posted by KLIPS developer Richard Guy Briggs:</P> -<PRE>Here is a catalogue of the types of errors that can occur for which -statistics are kept when transmitting and receiving packets via klips. -I notice that they are not necessarily logged in the right counter. -. . . - -Sources of ifconfig statistics for ipsec devices - -rx-errors: -- packet handed to ipsec_rcv that is not an ipsec packet. -- ipsec packet with payload length not modulo 4. -- ipsec packet with bad authenticator length. -- incoming packet with no SA. -- replayed packet. -- incoming authentication failed. -- got esp packet with length not modulo 8. - -tx_dropped: -- cannot process ip_options. -- packet ttl expired. -- packet with no eroute. -- eroute with no SA. -- cannot allocate sk_buff. -- cannot allocate kernel memory. -- sk_buff internal error. - - -The standard counters are: - -struct enet_statistics -{ - int rx_packets; /* total packets received */ - int tx_packets; /* total packets transmitted */ - int rx_errors; /* bad packets received */ - int tx_errors; /* packet transmit problems */ - int rx_dropped; /* no space in linux buffers */ - int tx_dropped; /* no space available in linux */ - int multicast; /* multicast packets received */ - int collisions; - - /* detailed rx_errors: */ - int rx_length_errors; - int rx_over_errors; /* receiver ring buff overflow */ - int rx_crc_errors; /* recved pkt with crc error */ - int rx_frame_errors; /* recv'd frame alignment error */ - int rx_fifo_errors; /* recv'r fifo overrun */ - int rx_missed_errors; /* receiver missed packet */ - - /* detailed tx_errors */ - int tx_aborted_errors; - int tx_carrier_errors; - int tx_fifo_errors; - int tx_heartbeat_errors; - int tx_window_errors; -}; - -of which I think only the first 6 are useful.</PRE> -<H3><A NAME="gdb"></A> 5.4 Using GDB on Pluto</H3> -<P>You may need to use the GNU debugger, gdb(1), on Pluto. This should - be necessary only in unusual cases, for example if you encounter a - problem which the Pluto developer cannot readily reproduce or if you - are modifying Pluto.</P> -<P>Here are the Pluto developer's suggestions for doing this:</P> -<PRE>Can you get a core dump and use gdb to find out what Pluto was doing -when it died? - -To get a core dump, you will have to set dumpdir to point to a -suitable directory (see <A HREF="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</A>). - -To get gdb to tell you interesting stuff: - $ script - $ cd dump-directory-you-chose - $ gdb /usr/local/lib/ipsec/pluto core - (gdb) where - (gdb) quit - $ exit - -The resulting output will have been captured by the script command in -a file called "typescript". Send it to the list. - -Do not delete the core file. I may need to ask you to print out some -more relevant stuff.</PRE> -<P> Note that the<VAR> dumpdir</VAR> parameter takes effect only when - the IPsec subsystem is restarted -- reboot or ipsec setup restart.</P> -<P> -<BR> -<BR></P> -<HR> -<H1><A name="compat">Linux FreeS/WAN Compatibility Guide</A></H1> -<P>Much of this document is quoted directly from the Linux FreeS/WAN<A href="mail.html"> - mailing list</A>. Thanks very much to the community of testers, - patchers and commenters there, especially the ones quoted below but - also various contributors we haven't quoted.</P> -<H2><A name="spec">Implemented parts of the IPsec Specification</A></H2> -<P>In general, do not expect Linux FreeS/WAN to do everything yet. This - is a work-in-progress and some parts of the IPsec specification are not - yet implemented.</P> -<H3><A name="in">In Linux FreeS/WAN</A></H3> -<P>Things we do, as of version 1.96:</P> -<UL> -<LI>key management methods -<DL> -<DT>manually keyed</DT> -<DD>using keys stored in /etc/ipsec.conf</DD> -<DT>automatically keyed</DT> -<DD>Automatically negotiating session keys as required. All connections - are automatically re-keyed periodically. The<A href="#Pluto"> Pluto</A> - daemon implements this using the<A href="#IKE"> IKE</A> protocol.</DD> -</DL> -</LI> -<LI>Methods of authenticating gateways for IKE -<DL> -<DT>shared secrets</DT> -<DD>stored in<A href="manpage.d/ipsec.secrets.5.html"> ipsec.secrets(5)</A> -</DD> -<DT><A href="#RSA">RSA</A> signatures</DT> -<DD>For details, see<A href="manpage.d/ipsec_pluto.8.html"> pluto(8)</A> -.</DD> -<DT>looking up RSA authentication keys from<A href="#DNS"> DNS</A>.</DT> -<DD>Note that this technique cannot be fully secure until<A href="#SDNS"> - secure DNS</A> is widely deployed.</DD> -</DL> -</LI> -<LI>groups for<A href="#DH"> Diffie-Hellman</A> key negotiation -<DL> -<DT>group 2, modp 1024-bit</DT> -<DT>group 5, modp 1536-bit</DT> -<DD>We implement these two groups. -<P>In negotiating a keying connection (ISAKMP SA, Phase 1) we propose - both groups when we are the initiator, and accept either when a peer - proposes them. Once the keying connection is made, we propose only the - alternative agreed there for data connections (IPsec SA's, Phase 2) - negotiated over that keying connection.</P> -</DD> -</DL> -</LI> -<LI>encryption transforms -<DL> -<DT><A href="#DES">DES</A></DT> -<DD>DES is in the source code since it is needed to implement 3DES, but - single DES is not made available to users because<A href="#desnotsecure"> - DES is insecure</A>.</DD> -<DT><A href="#3DES">Triple DES</A></DT> -<DD>implemented, and used as the default encryption in Linux FreeS/WAN.</DD> -</DL> -</LI> -<LI>authentication transforms -<DL> -<DT><A href="#HMAC">HMAC</A> using<A href="#MD5"> MD5</A></DT> -<DD>implemented, may be used in IKE or by by AH or ESP transforms.</DD> -<DT><A href="#HMAC">HMAC</A> using<A href="#SHA"> SHA</A></DT> -<DD>implemented, may be used in IKE or by AH or ESP transforms.</DD> -</DL> -<P>In negotiations, we propose both of these and accept either.</P> -</LI> -<LI>compression transforms -<DL> -<DT>IPComp</DT> -<DD>IPComp as described in RFC 2393 was added for FreeS/WAN 1.6. Note - that Pluto becomes confused if you ask it to do IPComp when the kernel - cannot.</DD> -</DL> -</LI> -</UL> -<P>All combinations of implemented transforms are supported. Note that - some form of packet-level<STRONG> authentication is required whenever - encryption is used</STRONG>. Without it, the encryption will not be - secure.</P> -<H3><A name="dropped">Deliberately omitted</A></H3> - We do not implement everything in the RFCs because some of those things - are insecure. See our discussions of avoiding<A href="#weak"> bogus - security</A>. -<P>Things we deliberately omit which are required in the RFCs are:</P> -<UL> -<LI>null encryption (to use ESP as an authentication-only service)</LI> -<LI>single DES</LI> -<LI>DH group 1, a 768-bit modp group</LI> -</UL> -<P>Since these are the only encryption algorithms and DH group the RFCs - require, it is possible in theory to have a standards-conforming - implementation which will not interpoperate with FreeS/WAN. Such an - implementation would be inherently insecure, so we do not consider this - a problem.</P> -<P>Anyway, most implementations sensibly include more secure options as - well, so dropping null encryption, single DES and Group 1 does not - greatly hinder interoperation in practice.</P> -<P>We also do not implement some optional features allowed by the RFCs:</P> -<UL> -<LI>aggressive mode for negotiation of the keying channel or ISAKMP SA. - This mode is a little faster than main mode, but exposes more - information to an eavesdropper.</LI> -</UL> -<P>In theory, this should cause no interoperation problems since all - implementations are required to support the more secure main mode, - whether or not they also allow aggressive mode.</P> -<P>In practice, it does sometimes produce problems with implementations - such as Windows 2000 where aggressive mode is the default. Typically, - these are easily solved with a configuration change that overrides that - default.</P> -<H3><A name="not">Not (yet) in Linux FreeS/WAN</A></H3> -<P>Things we don't yet do, as of version 1.96:</P> -<UL> -<LI>key management methods -<UL> -<LI>authenticate key negotiations via local<A href="#PKI"> PKI</A> - server, but see links to user<A href="#patch"> patches</A></LI> -<LI>authenticate key negotiations via<A href="#SDNS"> secure DNS</A></LI> -<LI>unauthenticated key management, using<A href="#DH"> Diffie-Hellman</A> - key agreement protocol without authentication. Arguably, this would be - worth doing since it is secure against all passive attacks. On the - other hand, it is vulnerable to an active<A href="#middle"> - man-in-the-middle attack</A>.</LI> -</UL> -</LI> -<LI>encryption transforms -<P>Currently<A href="#3DES"> Triple DES</A> is the only encryption - method Pluto will negotiate.</P> -<P>No additional encryption transforms are implemented, though the RFCs - allow them and some other IPsec implementations support various of - them. We are not eager to add more. See this<A href="#other.cipher"> - FAQ question</A>.</P> -<P><A href="#AES">AES</A>, the successor to the DES standard, is an - excellent candidate for inclusion in FreeS/WAN, see links to user<A href="#patch"> - patches</A>.</P> -</LI> -<LI>authentication transforms -<P>No optional additional authentication transforms are currently - implemented. Likely<A href="#SHA-256"> SHA-256, SHA-384 and SHA-512</A> - will be added when AES is.</P> -</LI> -<LI>Policy checking on decrypted packets -<P>To fully comply with the RFCs, it is not enough just to accept only - packets which survive any firewall rules in place to limit what IPsec - packets get in, and then pass KLIPS authentication. That is what - FreeS/WAN currently does.</P> -<P>We should also apply additional tests, for example ensuring that all - packets emerging from a particular tunnel have source and destination - addresses that fall within the subnets defined for that tunnel, and - that packets with those addresses that did not emerge from the - appropriate tunnel are disallowed.</P> -<P>This will be done as part of a KLIPS rewrite. See these<A href="#applied"> - links</A> and the<A href="mail.html"> design mailing list</A> for - discussion.</P> -</LI> -</UL> -<H2><A name="pfkey">Our PF-Key implementation</A></H2> -<P>We use PF-key Version Two for communication between the KLIPS kernel - code and the Pluto Daemon. PF-Key v2 is defined by<A href="http://www.normos.org/ietf/rfc/rfc2367.txt"> - RFC 2367</A>.</P> -<P>The "PF" stands for Protocol Family. PF-Inet defines a - kernel/userspace interface for the TCP/IP Internet protocols (TCP/IP), - and other members of the PF series handle Netware, Appletalk, etc. - PF-Key is just a PF for key-related matters.</P> -<H3><A name="pfk.port">PF-Key portability</A></H3> -<P>PF-Key came out of Berkeley Unix work and is used in the various BSD - IPsec implementations, and in Solaris. This means there is some hope of - porting our Pluto(8) to one of the BSD distributions, or of running - their photurisd(8) on Linux if you prefer<A href="#photuris"> Photuris</A> - key management over IKE.</P> -<P>It is, however, more complex than that. The PK-Key RFC deliberately - deals only with keying, not policy management. The three PF-Key - implementations we have looked at -- ours, OpenBSD and KAME -- all have - extensions to deal with security policy, and the extensions are - different. There have been discussions aimed at sorting out the - differences, perhaps for a version three PF-Key spec. All players are - in favour of this, but everyone involved is busy and it is not clear - whether or when these discussions might bear fruit.</P> -<H2><A name="otherk">Kernels other than the latest 2.2.x and 2.4.y</A></H2> -<P>We develop and test on Redhat Linux using the most recent kernel in - the 2.2 and 2.4 series. In general, we recommend you use the latest - kernel in one of those series. Complications and caveats are discussed - below.</P> -<H3><A name="kernel.2.0">2.0.x kernels</A></H3> -<P>Consider upgrading to the 2.2 kernel series. If you want to stay with - the 2.0 series, then we strongly recommend 2.0.39. Some useful security - patches were added in 2.0.38.</P> -<P>Various versions of the code have run at various times on most 2.0.xx - kernels, but the current version is only lightly tested on 2.0.39, and - not at all on older kernels.</P> -<P>Some of our patches for older kernels are shipped in 2.0.37 and - later, so they are no longer provided in FreeS/WAN. This means recent - versions of FreeS/WAN will probably not compile on anything earlier - than 2.0.37.</P> -<H3><A name="kernel.production">2.2 and 2.4 kernels</A></H3> -<DL> -<DT>FreeS/WAN 1.0</DT> -<DD>ran only on 2.0 kernels</DD> -<DT>FreeS/WAN 1.1 to 1.8</DT> -<DD>ran on 2.0 or 2.2 kernels -<BR> ran on some development kernels, 2.3 or 2.4-test</DD> -<DT>FreeS/WAN 1.9 to 1.96</DT> -<DD>runs on 2.0, 2.2 or 2.4 kernels</DD> -</DL> -<P>In general,<STRONG> we suggest the latest 2.2 kernel or 2.4 for - production use</STRONG>.</P> -<P>Of course no release can be guaranteed to run on kernels more recent - than it is, so quite often there will be no stable FreeS/WAN for the - absolute latest kernel. See the<A href="#k.versions"> FAQ</A> for - discussion.</P> -<H2><A name="otherdist">Intel Linux distributions other than Redhat</A></H2> -<P>We develop and test on Redhat 6.1 for 2.2 kernels, and on Redhat 7.1 - or 7.2 for 2.4, so minor changes may be required for other - distributions.</P> -<H3><A name="rh7">Redhat 7.0</A></H3> -<P>There are some problems with FreeS/WAN on Redhat 7.0. They are - soluble, but we recommend you upgrade to a later Redhat instead..</P> -<P>Redhat 7 ships with two compilers.</P> -<UL> -<LI>Their<VAR> gcc</VAR> is version 2.96. Various people, including the - GNU compiler developers and Linus, have said fairly emphatically that - using this was a mistake. 2.96 is a development version, not intended - for production use. In particular, it will not compile a Linux kernel.</LI> -<LI>Redhat therefore also ship a separate compiler, which they call<VAR> - kgcc</VAR>, for compiling kernels.</LI> -</UL> -<P>Kernel Makefiles have<VAR> gcc</VAR> as a default, and must be - adjusted to use<VAR> kgcc</VAR> before a kernel will compile on 7.0. - This mailing list message gives details:</P> -<PRE>Subject: Re: AW: Installing IPsec on Redhat 7.0 - Date: Thu, 1 Feb 2001 14:32:52 -0200 (BRST) - From: Mads Rasmussen <mads@cit.com.br> - -> From www.redhat.com/support/docs/gotchas/7.0/gotchas-7-6.html#ss6.1 - -cd to /usr/src/linux and open the Makefile in your favorite editor. You -will need to look for a line similar to this: - -CC = $(CROSS_COMPILE)gcc -D__KERNEL__ -I$(HPATH) - -This line specifies which C compiler to use to build the kernel. It should -be changed to: - -CC = $(CROSS_COMPILE)kgcc -D__KERNEL__ -I$(HPATH) - -for Red Hat Linux 7. The kgcc compiler is egcs 2.91.66. From here you can -proceed with the typical compiling steps.</PRE> -<P>Check the<A href="mail.html"> mailing list</A> archive for more - recent news.</P> -<H3><A name="suse">SuSE Linux</A></H3> -<P>SuSE 6.3 and later versions, at least in Europe, ship with FreeS/WAN - included.</P> -<P>FreeS/WAN packages distributed for SuSE 7.0-7.2 were somehow - miscompiled. You can find fixed packages on<A HREF="http://www.suse.de/~garloff/linux/FreeSWAN"> - Kurt Garloff's page</A>.</P> -<P>Here are some notes for an earlier SuSE version.</P> -<H4><A NAME="9_4_2_1">SuSE Linux 5.3</A></H4> -<PRE>Date: Mon, 30 Nov 1998 -From: Peter Onion <ponion@srd.bt.co.uk> - -... I got Saturdays snapshot working between my two SUSE5.3 machines at home. - -The mods to the install process are quite simple. From memory and looking at -the files on the SUSE53 machine here at work.... - -And extra link in each of the /etc/init.d/rc?.d directories called K35ipsec -which SUSE use to shut a service down. - -A few mods in /etc/init.d/ipsec to cope with the different places that SUSE -put config info, and remove the inculsion of /etc/rc.d/init.d/functions and . -/etc/sysconfig/network as they don't exists and 1st one isn't needed anyway. - -insert ". /etc/rc.config" to pick up the SUSE config info and use - - if test -n "$NETCONFIG" -a "$NETCONFIG" != "YAST_ASK" ; then - -to replace - - [ ${NETWORKING} = "no" ] && exit 0 - -Create /etc/sysconfig as SUSE doesn't have one. - -I think that was all (but I prob forgot something)....</PRE> -<P>You may also need to fiddle initialisation scripts to ensure that<VAR> - /var/run/pluto.pid</VAR> is removed when rebooting. If this file is - present, Pluto does not come up correctly.</P> -<H3><A name="slack">Slackware</A></H3> -<PRE>Subject: Re: linux-IPsec: Slackware distribution - Date: Thu, 15 Apr 1999 12:07:01 -0700 - From: Evan Brewer <dmessiah@silcon.com> - -> Very shortly, I will be needing to install IPsec on at least gateways that -> are running Slackware. . . . - -The only trick to getting it up is that on the slackware dist there is no -init.d directory in /etc/rc.d .. so create one. Then, what I do is take the -IPsec startup script which normally gets put into the init.d directory, and -put it in /etc/rc.d and name ir rc.ipsec .. then I symlink it to the file -in init.d. The only file in the dist you need to really edit is the -utils/Makefile, setup4: - -Everything else should be just fine.</PRE> -<P>A year or so later:</P> -<PRE>Subject: Re: HTML Docs- Need some cleanup? - Date: Mon, 8 Jan 2001 - From: Jody McIntyre <jodym@oeone.com> - -I have successfully installed FreeS/WAN on several Slackware 7.1 machines. -FreeS/WAN installed its rc.ipsec file in /etc/rc.d. I had to manually call -this script from rc.inet2. This seems to be an easier method than Evan -Brewer's.</PRE> -<H3><A name="deb">Debian</A></H3> -<P>A recent (Nov 2001) mailing list points to a<A href="http://www.thing.dyndns.org/debian/vpn.htm"> - web page</A> on setting up several types of tunnel, including IPsec, on - Debian.</P> -<P>Some older information:</P> -<PRE>Subject: FreeS/WAN 1.0 on Debian 2.1 - Date: Tue, 20 Apr 1999 - From: Tim Miller <cerebus+counterpane@haybaler.sackheads.org> - - Compiled and installed without error on a Debian 2.1 system -with kernel-source-2.0.36 after pointing RCDIR in utils/Makefile to -/etc/init.d. - - /var/lock/subsys/ doesn't exist on Debian boxen, needs to be -created; not a fatal error. - - Finally, IPsec scripts appear to be dependant on GNU awk -(gawk); the default Debian awk (mawk-1.3.3-2) had fatal difficulties. -With gawk installed and /etc/alternatives/awk linked to /usr/bin/gawk -operation appears flawless.</PRE> -<P>The scripts in question have been modified since this was posted. Awk - versions should no longer be a problem.</P> -<H3><A name="caldera">Caldera</A></H3> -<PRE>Subject: Re: HTML Docs- Need some cleanup? - Date: Mon, 08 Jan 2001 - From: Andy Bradford <andyb@calderasystems.com> - -On Sun, 07 Jan 2001 22:59:05 EST, Sandy Harris wrote: - -> Intel Linux distributions other than Redhat 5.x and 6.x -> Redhat 7.0 -> SuSE Linux -> SuSE Linux 5.3 -> Slackware -> Debian - -Can you please include Caldera in this list? I have tested it since -FreeS/Wan 1.1 and it works great with our systems---provided one -follows the FreeS/Wan documentation. :-) - -Thank you, -Andy</PRE> -<H2><A name="CPUs">CPUs other than Intel</A></H2> -<P>FreeS/WAN has been run sucessfully on a number of different CPU - architectures. If you have tried it on one not listed here, please post - to the<A href="mail.html"> mailing list</A>.</P> -<H3><A name=" strongarm">Corel Netwinder (StrongARM CPU)</A></H3> -<PRE>Subject: linux-ipsec: Netwinder diffs -Date: Wed, 06 Jan 1999 -From: rhatfield@plaintree.com - -I had a mistake in my IPsec-auto, so I got things working this morning. - -Following are the diffs for my changes. Probably not the best and cleanest way -of doing it, but it works. . . . </PRE> -<P>These diffs are in the 0.92 and later distributions, so these should - work out-of-the-box on Netwinder.</P> -<H3><A name="yellowdog">Yellow Dog Linux on Power PC</A></H3> -<PRE>Subject: Compiling FreeS/WAN 1.1 on YellowDog Linux (PPC) - Date: 11 Dec 1999 - From: Darron Froese <darron@fudgehead.com> - -I'm summarizing here for the record - because it's taken me many hours to do -this (multiple times) and because I want to see IPsec on more linuxes than -just x86. - -Also, I can't remember if I actually did summarize it before... ;-) I'm -working too many late hours. - -That said - here goes. - -1. Get your linux kernel and unpack into /usr/src/linux/ - I used 2.2.13. -<http://www.kernel.org/pub/linux/kernel/v2.2/linux-2.2.13.tar.bz2> - -2. Get FreeS/WAN and unpack into /usr/src/freeswan-1.1 -<ftp://ftp.xs4all.nl/pub/crypto/freeswan/freeswan-1.1.tar.gz> - -3. Get the gmp src rpm from here: -<ftp://ftp.yellowdoglinux.com//pub/yellowdog/champion-1.1/SRPMS/SRPMS/gmp-2.0.2-9a.src.rpm> - -4. Su to root and do this: rpm --rebuild gmp-2.0.2-9a.src.rpm - -You will see a lot of text fly by and when you start to see the rpm -recompiling like this: - -Executing: %build -+ umask 022 -+ cd /usr/src/redhat/BUILD -+ cd gmp-2.0.2 -+ libtoolize --copy --force -Remember to add `AM_PROG_LIBTOOL' to `configure.in'. -You should add the contents of `/usr/share/aclocal/libtool.m4' to -`aclocal.m4'. -+ CFLAGS=-O2 -fsigned-char -+ ./configure --prefix=/usr - -Hit Control-C to stop the rebuild. NOTE: We're doing this because for some -reason the gmp source provided with FreeS/WAN 1.1 won't build properly on -ydl. - -cd /usr/src/redhat/BUILD/ -cp -ar gmp-2.0.2 /usr/src/freeswan-1.1/ -cd /usr/src/freeswan-1.1/ -rm -rf gmp -mv gmp-2.0.2 gmp - -5. Open the freeswan Makefile and change the line that says: -KERNEL=$(b)zimage (or something like that) to -KERNEL=vmlinux - -6. cd ../linux/ - -7. make menuconfig -Select an option or two and then exit - saving your changes. - -8. cd ../freeswan-1.1/ ; make menugo - -That will start the whole process going - once that's finished compiling, -you have to install your new kernel and reboot. - -That should build FreeS/WAN on ydl (I tried it on 1.1).</PRE> - And a later message on the same topic: -<PRE>Subject: Re: FreeS/WAN, PGPnet and E-mail - Date: Sat, 22 Jan 2000 - From: Darron Froese <darron@fudgehead.com> - -on 1/22/00 6:47 PM, Philip Trauring at philip@trauring.com wrote: - -> I have a PowerMac G3 ... - -The PowerMac G3 can run YDL 1.1 just fine. It should also be able to run -FreeS/WAN 1.2patch1 with a couple minor modifications: - -1. In the Makefile it specifies a bzimage for the kernel compile - you have -to change that to vmlinux for the PPC. - -2. The gmp source that comes with FreeS/WAN (for whatever reason) fails to -compile. I have gotten around this by getting the gmp src rpm from here: - -ftp://ftp.yellowdoglinux.com//pub/yellowdog/champion-1.1/SRPMS/SRPMS/gmp-2.0.2-9a.src.rpm - -If you rip the source out of there - and place it where the gmp source -resides it will compile just fine.</PRE> -<P>FreeS/WAN no longer includes GMP source.</P> -<H3><A name="mklinux">Mklinux</A></H3> -<P>One user reports success on the Mach-based<STRONG> m</STRONG>icro<STRONG> -k</STRONG>ernel Linux.</P> -<PRE>Subject: Smiles on sparc and ppc - Date: Fri, 10 Mar 2000 - From: Jake Hill <jah@alien.bt.co.uk> - -You may or may not be interested to know that I have successfully built -FreeS/WAN on a number of non intel alpha architectures; namely on ppc -and sparc and also on osfmach3/ppc (MkLinux). I can report that it just -works, mostly, with few changes.</PRE> -<H3><A name="alpha">Alpha 64-bit processors</A></H3> -<PRE>Subject: IT WORKS (again) between intel & alpha :-))))) - Date: Fri, 29 Jan 1999 - From: Peter Onion <ponion@srd.bt.co.uk> - -Well I'm happy to report that I've got an IPsec connection between by intel & alpha machines again :-)) - -If you look back on this list to 7th of December I wrote... - --On 07-Dec-98 Peter Onion wrote: --> --> I've about had enuf of wandering around inside the kernel trying to find out --> just what is corrupting outgoing packets... -- --Its 7:30 in the evening ..... -- --I FIXED IT :-)))))))))))))))))))))))))))))))) -- --It was my own fault :-(((((((((((((((((( -- --If you ask me very nicly I'll tell you where I was a little too over keen to --change unsigned long int __u32 :-) OPSE ... -- --So tomorrow it will full steam ahead to produce a set of diffs/patches against --0.91 -- --Peter Onion.</PRE> -<P>In general (there have been some glitches), FreeS/WAN has been - running on Alphas since then.</P> -<H3><A name="SPARC">Sun SPARC processors</A></H3> -<P>Several users have reported success with FreeS/WAN on SPARC Linux. - Here is one mailing list message:</P> -<PRE>Subject: Smiles on sparc and ppc - Date: Fri, 10 Mar 2000 - From: Jake Hill <jah@alien.bt.co.uk> - -You may or may not be interested to know that I have successfully built -FreeS/WAN on a number of non intel alpha architectures; namely on ppc -and sparc and also on osfmach3/ppc (MkLinux). I can report that it just -works, mostly, with few changes. - -I have a question, before I make up some patches. I need to hack -gmp/mpn/powerpc32/*.s to build them. Is this ok? The changes are -trivial, but could I also use a different version of gmp? Is it vanilla -here? - -I guess my only real headache is from ipchains, which appears to stop -running when IPsec has been started for a while. This is with 2.2.14 on -sparc.</PRE> -<P>This message, from a different mailing list, may be relevant for - anyone working with FreeS/WAN on Suns:</P> -<PRE>Subject: UltraSPARC DES assembler - Date: Thu, 13 Apr 2000 - From: svolaf@inet.uni2.dk (Svend Olaf Mikkelsen) - To: coderpunks@toad.com - -An UltraSPARC assembler version of the LibDES/SSLeay/OpenSSL des_enc.c -file is available at http://inet.uni2.dk/~svolaf/des.htm. - -This brings DES on UltraSPARC from slower than Pentium at the same -clock speed to significantly faster.</PRE> -<H3><A name="mips">MIPS processors</A></H3> -<P>We know FreeS/WAN runs on at least some MIPS processors because<A href="http://www.lasat.com"> - Lasat</A> manufacture an IPsec box based on an embedded MIPS running - Linux with FreeS/WAN. We have no details.</P> -<H3><A name="crusoe">Transmeta Crusoe</A></H3> -<P>The Merilus<A href="http://www.merilus.com/products/fc/index.shtml"> - Firecard</A>, a Linux firewall on a PCI card, is based on a Crusoe - processor and supports FreeS/WAN.</P> -<H3><A name="coldfire">Motorola Coldfire</A></H3> -<PRE>Subject: Re: Crypto hardware support - Date: Mon, 03 Jul 2000 - From: Dan DeVault <devault@tampabay.rr.com> - -.... I have been running -uClinux with FreeS/WAN 1.4 on a system built by Moreton Bay ( -http://www.moretonbay.com ) and it was using a Coldfire processor -and was able to do the Triple DES encryption at just about -1 mbit / sec rate....... they put a Hi/Fn 7901 hardware encryption -chip on their board and now their system does over 25 mbit of 3DES -encryption........ pretty significant increase if you ask me.</PRE> -<H2><A name="multiprocessor">Multiprocessor machines</A></H2> -<P>FreeS/WAN is designed to work on SMP (symmetric multi-processing) - Linux machines and is regularly tested on dual processor x86 machines.</P> -<P>We do not know of any testing on multi-processor machines with other - CPU architectures or with more than two CPUs. Anyone who does test - this, please report results to the<A href="mail.html"> mailing list</A> -.</P> -<P>The current design does not make particularly efficient use of - multiprocessor machines; some of the kernel work is single-threaded.</P> -<H2><A name="hardware">Support for crypto hardware</A></H2> -<P>Supporting hardware cryptography accelerators has not been a high - priority for the development team because it raises a number of fairly - complex issues:</P> -<UL> -<LI>Can you trust the hardware? If it is not Open Source, how do you - audit its security? Even if it is, how do you check that the design has - no concealed traps?</LI> -<LI>If an interface is added for such hardware, can that interface be - subverted or misused?</LI> -<LI>Is hardware acceleration actually a performance win? It clearly is - in many cases, but on a fast machine it might be better to use the CPU - for the encryption than to pay the overheads of moving data to and from - a crypto board.</LI> -<LI>the current KLIPS code does not provide a clean interface for - hardware accelerators</LI> -</UL> -<P>That said, we have a<A href="#coldfire"> report</A> of FreeS/WAN - working with one crypto accelerator and some work is going on to modify - KLIPS to create a clean generic interface to such products. See this<A href="http://www.jukie.net/~bart/linux-ipsec/"> - web page</A> for some of the design discussion.</P> -<P>More recently, a patch to support some hardware accelerators has been - posted:</P> -<PRE>Subject: [Design] [PATCH] H/W acceleration patch - Date: Tue, 18 Sep 2001 - From: "Martin Gadbois" <martin.gadbois@colubris.com> - -Finally!! -Here's a web site with H/W acceleration patch for FreeS/WAN 1.91, including -S/W and Hifn 7901 crypto support. - -http://sources.colubris.com/ - -Martin Gadbois</PRE> -<P>Hardware accelerators could take performance well beyond what - FreeS/WAN can do in software (discussed<A href="performance.html"> here</A> -). Here is some discussion off the IETF IPsec list, October 2001:</P> -<PRE> ... Currently shipping chips deliver, 600 mbps throughput on a single - stream of 3DES IPsec traffic. There are also chips that use multiple - cores to do 2.4 gbps. We (Cavium) and others have announced even faster - chips. ... Mid 2002 versions will handle at line rate (OC48 and OC192) - IPsec and SSL/TLS traffic not only 3DES CBC but also AES and arc4.</PRE> -<P>The patches to date support chips that have been in production for - some time, not the state-of-the-art latest-and-greatest devices - described in that post. However, they may still outperform software and - they almost certainly reduce CPU overhead.</P> -<H2><A name="ipv6">IP version 6 (IPng)</A></H2> -<P>The Internet currently runs on version four of the IP protocols. IPv4 - is what is in the standard Linux IP stack, and what FreeS/WAN was built - for. In IPv4, IPsec is an optional feature.</P> -<P>The next version of the IP protocol suite is version six, usually - abbreviated either as "IPv6" or as "IPng" for "IP: the next - generation". For IPv6, IPsec is a required feature. Any machine doing - IPv6 is required to support IPsec, much as any machine doing (any - version of) IP is required to support ICMP.</P> -<P>There is a Linux implementation of IPv6 in Linux kernels 2.2 and - above. For details, see the<A href="http://www.cs-ipv6.lancs.ac.uk/ipv6/systems/linux/faq/"> - FAQ</A>. It does not yet support IPsec. The<A href="http://www.linux-ipv6.org/"> - USAGI</A> project are also working on IPv6 for Linux.</P> -<P>FreeS/WAN was originally built for the current standard, IPv4, but we - are interested in seeing it work with IPv6. Some progress has been - made, and a patched version with IPv6 support is<A href="http://www.ipv6.iabg.de/downloadframe/index.html"> - available</A>. For more recent information, check the<A href="mail.html"> - mailing list</A>.</P> -<H3><A name="v6.back">IPv6 background</A></H3> -<P>IPv6 has been specified by an IETF<A href="http://www.ietf.org/html.charters/ipngwg-charter.html"> - working group</A>. The group's page lists over 30 RFCs to date, and - many Internet Drafts as well. The overview is<A href="http://www.ietf.org/rfc/rfc2460.txt"> - RFC 2460</A>. Major features include:</P> -<UL> -<LI>expansion of the address space from 32 to 128 bits,</LI> -<LI>changes to improve support for -<UL> -<LI>mobile IP</LI> -<LI>automatic network configuration</LI> -<LI>quality of service routing</LI> -<LI>...</LI> -</UL> -</LI> -<LI>improved security via IPsec</LI> -</UL> -<P>A number of projects are working on IPv6 implementation. A prominent - Open Source effort is<A href="http://www.kame.net/"> KAME</A>, a - collaboration among several large Japanese companies to implement IPv6 - for Berkeley Unix. Other major players are also working on IPv6. For - example, see pages at:</P> -<UL> -<LI><A href="http://playground.sun.com/pub/ipng/html/ipng-main.html">Sun</A> -</LI> -<LI><A href="http://www.cisco.com/warp/public/732/ipv6/index.html">Cisco</A> -</LI> -<LI><A href="http://www.microsoft.com/windows2000/techinfo/howitworks/communications/networkbasics/IPv6.asp"> -Microsoft</A></LI> -</UL> -<P>The<A href="http://www.6bone.net/"> 6bone</A> (IPv6 backbone) testbed - network has been up for some time. There is an active<A href="http://www.ipv6.org/"> - IPv6 user group</A>.</P> -<P>One of the design goals for IPv6 was that it must be possible to - convert from v4 to v6 via a gradual transition process. Imagine the - mess if there were a "flag day" after which the entire Internet used - v6, and all software designed for v4 stopped working. Almost every - computer on the planet would need major software changes! There would - be huge costs to replace older equipment. Implementers would be worked - to death before "the day", systems administrators and technical support - would be completely swamped after it. The bugs in every implementation - would all bite simultaneously. Large chunks of the net would almost - certainly be down for substantial time periods. ...</P> -<P>Fortunately, the design avoids any "flag day". It is therefore a - little tricky to tell how quickly IPv6 will take over. The transition - has certainly begun. For examples, see announcements from<A href="http://www.mailbase.ac.uk/lists/internet2/2000-03/0016.html"> - NTT</A> and<A href="http://www.vnunet.com/News/1102383"> Nokia</A>. - However, it is not yet clear how quickly the process will gain - momentum, or when it will be completed. Likely large parts of the - Internet will remain with IPv4 for years to come.</P> -<HR> -<A NAME="interop"></A> -<H1><A NAME="10">Interoperating with FreeS/WAN</A></H1> -<P>The FreeS/WAN project needs you! We rely on the user community to - keep up to date. Mail users@lists.freeswan.org with your interop - success stories.</P> -<P><STRONG>Please note</STRONG>: Most of our interop examples feature - Linux FreeS/WAN 1.x config files. You can convert them to 2.x files - fairly easily with the patch in our<A HREF="#ipsec.conf_v2"> Upgrading - Guide</A>.</P> -<H2><A NAME="10_1">Interop at a Glance</A></H2> -<TABLE BORDER="1"> -<TR><TD> </TD><TD colspan="5">FreeS/WAN VPN</TD><TD>Road Warrior</TD><TD> -OE</TD></TR> -<TR><TD> </TD><TD>PSK</TD><TD>RSA Secret</TD><TD>X.509 -<BR><SMALL><A HREF="#interoprules">(requires patch)</A></SMALL></TD><TD> -NAT-Traversal -<BR><SMALL><A HREF="#interoprules">(requires patch)</A></SMALL></TD><TD> -Manual -<BR>Keying</TD><TD> </TD><TD> </TD></TR> -<TR><TD colspan="8">More Compatible</TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#freeswan">FreeS/WAN</A><A NAME="freeswan.top"> </A></TD><TD> -<FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#00cc00">Yes</FONT> -</TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD><FONT color="#00cc00">Yes</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#isakmpd">isakmpd (OpenBSD)</A><A NAME="isakmpd.top"> </A> -</TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> -<FONT color="#cc0000">No </FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#kame">Kame (FreeBSD, -<BR> NetBSD, MacOSX) -<BR> <SMALL>aka racoon</SMALL></A><A NAME="kame.top"> </A></TD><TD><FONT -color="#00cc00">Yes</FONT></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> -<FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#mcafee">McAfee VPN -<BR><SMALL>was PGPNet</SMALL></A><A NAME="mcafee.top"> </A></TD><TD><FONT -color="#00cc00">Yes</FONT></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> -<FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#microsoft">Microsoft -<BR> Windows 2000/XP</A><A NAME="microsoft.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> - </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#cc0000"> -No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#ssh">SSH Sentinel</A><A NAME="ssh.top"> </A></TD><TD><FONT -color="#00cc00">Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT> -</TD><TD><FONT color="#cccc00">Maybe</FONT></TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#safenet">Safenet SoftPK -<BR>/SoftRemote</A><A NAME="safenet.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> - </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#cc0000"> -No</FONT></TD></TR> -<TR><TD colspan="8">Other</TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#6wind">6Wind</A><A NAME="6wind.top"> </A></TD><TD> </TD><TD> - </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> -<FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#alcatel">Alcatel Timestep</A><A NAME="alcatel.top"> </A> -</TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> - </TD><TD> </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#apple">Apple Macintosh -<BR>System 10+</A><A NAME="apple.top"> </A></TD><TD><FONT color="#cccc00"> -Maybe</FONT></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#cccc00"> -Maybe</FONT></TD><TD> </TD><TD><FONT color="#cccc00">Maybe</FONT></TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#ashleylaurent">AshleyLaurent -<BR> VPCom</A><A NAME="ashleylaurent.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT -color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#borderware">Borderware</A><A NAME="borderware.top"> </A> -</TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD><TD><FONT color="#cc0000"> -No</FONT></TD></TR> - -<!-- -http://www.cequrux.com/vpn-guides.php3 -"coming soon" guide to connect with FreeS/WAN. ---> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#checkpoint">Check Point FW-1/VPN-1</A><A NAME="checkpoint.top"> - </A></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> -<FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#cisco">Cisco with 3DES</A><A NAME="cisco.top"> </A></TD><TD> -<FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#cccc00">Maybe</FONT> -</TD><TD> </TD><TD><FONT color="#cccc00">Maybe</FONT></TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#equinux">Equinux VPN Tracker -<BR> (for Mac OS X)</A><A NAME="equinux.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD><FONT color="#cccc00">Maybe</FONT></TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#fsecure">F-Secure</A><A NAME="fsecure.top"> </A></TD><TD> -<FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD><FONT color="#cccc00"> -Maybe</FONT></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#gauntlet">Gauntlet GVPN</A><A NAME="gauntlet.top"> </A> -</TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT color="#cc0000"> -No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#aix">IBM AIX</A><A NAME="aix.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD><FONT color="#cccc00">Maybe</FONT></TD><TD> - </TD><TD> </TD><TD> </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#as400">IBM AS/400</A><A NAME="as400"> </A></TD><TD><FONT -color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#intel">Intel Shiva -<BR>LANRover/Net Structure</A><A NAME="intel.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT -color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#lancom">LanCom (formerly ELSA)</A><A NAME="lancom.top"> - </A></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> - </TD><TD> </TD><TD> </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#linksys">Linksys</A><A NAME="linksys.top"> </A></TD><TD> -<FONT color="#cccc00">Maybe</FONT></TD><TD> </TD><TD><FONT color="#cc0000"> -No</FONT></TD><TD> </TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> -<FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#lucent">Lucent</A><A NAME="lucent.top"> </A></TD><TD><FONT -color="#cccc00">Partial</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#netasq">Netasq</A><A NAME="netasq.top"> </A></TD><TD> - </TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#netcelo">netcelo</A><A NAME="netcelo.top"> </A></TD><TD> - </TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#netgear">Netgear fvs318</A><A NAME="netgear.top"> </A> -</TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> - </TD><TD> </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#netscreen">Netscreen 100 -<BR>or 5xp</A><A NAME="netscreen.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT color="#cccc00"> -Maybe</FONT></TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#nortel">Nortel Contivity</A><A NAME="nortel.top"> </A> -</TD><TD><FONT color="#cccc00">Partial</FONT></TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD><FONT color="#cccc00">Maybe</FONT></TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#radguard">RadGuard</A><A NAME="radguard.top"> </A></TD><TD> -<FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#raptor">Raptor</A><A NAME="raptor"> </A></TD><TD><FONT -color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#redcreek">Redcreek Ravlin</A><A NAME="redcreek.top"> </A> -</TD><TD><FONT color="#00cc00">Yes</FONT><FONT color="#cccc00">/Partial</FONT> -</TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT color="#cc0000"> -No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#sonicwall">SonicWall</A><A NAME="sonicwall.top"> </A></TD><TD> -<FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT -color="#cccc00">Maybe</FONT></TD><TD><FONT color="#cc0000">No</FONT></TD><TD> -<FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#sun">Sun Solaris</A><A NAME="sun.top"> </A></TD><TD><FONT -color="#00cc00">Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT> -</TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD><FONT -color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#symantec">Symantec</A><A NAME="symantec.top"> </A></TD><TD> -<FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#watchguard">Watchguard -<BR> Firebox</A><A NAME="watchguard.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#xedia">Xedia Access Point -<BR>/QVPN</A><A NAME="xedia.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT -color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#zyxel">Zyxel Zywall -<BR>/Prestige</A><A NAME="zyxel.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT -color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE - - -<TR> -<TD><A HREF="#sample">sample</A></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - ---> -<TR><TD> </TD><TD>PSK</TD><TD>RSA Secret</TD><TD>X.509 -<BR><SMALL><A HREF="#interoprules">(requires patch)</A></SMALL></TD><TD> -NAT-Traversal -<BR><SMALL><A HREF="#interoprules">(requires patch)</A></SMALL></TD><TD> -Manual -<BR>Keying</TD><TD> </TD><TD> </TD></TR> -<TR><TD> </TD><TD colspan="5">FreeS/WAN VPN</TD><TD>Road Warrior</TD><TD> -OE</TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -</TABLE> -<H3><A NAME="10_1_1">Key</A></H3> -<TABLE BORDER="1"> -<TR><TD><FONT color="#00cc00">Yes</FONT></TD><TD>People report that this - works for them.</TD></TR> -<TR><TD>[Blank]</TD><TD>We don't know.</TD></TR> -<TR><TD><FONT color="#cc0000">No</FONT></TD><TD>We have reason to - believe it was, at some point, not possible to get this to work.</TD></TR> -<TR><TD><FONT color="#cccc00">Partial</FONT></TD><TD>Partial success. - For example, a connection can be created from one end only.</TD></TR> -<TR><TD><FONT color="#00cc00">Yes</FONT><FONT color="#cccc00">/Partial</FONT> -</TD><TD>Mixed reports.</TD></TR> -<TR><TD><FONT color="#cccc00">Maybe</FONT></TD><TD>We think the answer - is "yes", but need confirmation.</TD></TR> -</TABLE> -<A NAME="interoprules"></A> -<H2><A NAME="10_2">Basic Interop Rules</A></H2> -<P>Vanilla FreeS/WAN implements<A HREF="#compat"> these parts</A> of the - IPSec specifications. You can add more with<A HREF="http://www.freeswan.ca"> - Super FreeS/WAN</A>, but what we offer may be enough for many users.</P> -<UL> -<LI> To use X.509 certificates with FreeS/WAN, you will need the<A HREF="http://www.strongsec.org/freeswan"> - X.509 patch</A> or<A HREF="http://www.freeswan.ca"> Super FreeS/WAN</A> -, which includes that patch.</LI> -<LI> To use<A HREF="#NAT.gloss"> Network Address Translation</A> (NAT) - traversal with FreeS/WAN, you will need Arkoon Network Security's<A HREF="http://open-source.arkoon.net"> - NAT traversal patch</A> or<A HREF="http://www.freeswan.ca"> Super - FreeS/WAN</A>, which includes it.</LI> -</UL> -<P>We offer a set of proposals which is not user-adjustable, but covers - all combinations that we can offer. FreeS/WAN always proposes triple - DES encryption and Perfect Forward Secrecy (PFS). In addition, we - propose Diffie Hellman groups 5 and 2 (in that order), and MD5 and - SHA-1 hashes. We accept the same proposals, in the same order of - preference.</P> -<P>Other interop notes:</P> -<UL> -<LI> A<A HREF="http://lists.freeswan.org/archives/users/2003-September/msg00462.html"> - SHA-1 bug in FreeS/WAN 2.00, 2.01 and 2.02</A> may affect some interop - scenarios. It does not affect 1.x versions, and is fixed in 2.03 and - later.</LI> -<LI> Some other implementations will close a connection with FreeS/WAN - after some time. This may be a problem with rekey lifetimes. Please see<A -HREF="http://lists.freeswan.org/archives/users/2003-October/msg00293.html"> - this tip</A> and<A HREF="http://lists.freeswan.org/pipermail/users/2001-December/005758.html"> - this workaround</A>.</LI> -</UL> -<H2><A NAME="10_3">Longer Stories</A></H2> -<H3><A NAME="10_3_1">For<EM> More Compatible</EM> Implementations</A></H3> -<H4><A NAME="freeswan">FreeS/WAN</A></H4> -<P> See our documentation at<A HREF="http://www.freeswan.org"> - freeswan.org</A> and the Super FreeS/WAN docs at<A HREF="http://www.freeswan.ca"> - freeswan.ca</A>. Some user-written HOWTOs for FreeS/WAN-FreeS/WAN - connections are listed in<A HREF="#howto"> our Introduction</A>.</P> -<P>See also:</P> -<UL> -<LI><A HREF="http://lugbe.ch/action/reports/ipsec_htbe.phtml"> A German - FreeS/WAN-FreeS/WAN page by Markus Wernig (X.509)</A></LI> -</UL> -<P><A HREF="#freeswan.top">Back to chart</A></P> -<H4><A NAME="isakmpd">isakmpd (OpenBSD)</A></H4> -<P><A HREF="http://www.openbsd.org/faq/faq13.html">OpenBSD FAQ: Using - IPsec</A> -<BR><A HREF="http://www.rommel.stw.uni-erlangen.de/~hshoexer/ipsec-howto/HOWTO.html"> - Hans-Joerg Hoexer's interop Linux-OpenBSD (PSK)</A> -<BR><A HREF="http://www.segfault.net/ipsec/"> Skyper's configuration - (PSK)</A> -<BR><A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> - French page with configs (X.509)</A></P> -<P><A HREF="#isakmpd.top">Back to chart</A></P> -<H4><A NAME="kame">Kame</A></H4> -<UL> -<LI>For FreeBSD and NetBSD. Ships with Mac OS X; see also our<A HREF="#apple"> - Mac</A> section.</LI> -<LI>Also known as<EM> racoon</EM>, its keying daemon.</LI> -</UL> -<P><A HREF="http://www.kame.net">Kame homepage, with FAQ</A> -<BR><A HREF="http://www.netbsd.org/Documentation/network/ipsec"> - NetBSD's IPSec FAQ</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/12/msg00560.html"> - Ghislaine's post explaining some interop peculiarities</A></P> -<P><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/09/msg00511.html"> - Itojun's Kame-FreeS/WAN interop tips (PSK)</A> -<BR><A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2000"> Ghislaine - Labouret's French page with links to matching FreeS/WAN and Kame - configs (RSA)</A> -<BR><A HREF="http://lugbe.ch/lostfound/contrib/freebsd_router/"> Markus - Wernig's HOWTO (X.509, BSD gateway)</A> -<BR><A HREF="http://web.morgul.net/~frodo/docs/kame+freeswan_interop.html"> - Frodo's Kame-FreeS/WAN interop (X.509)</A> -<BR><A HREF="http://www.wavesec.org/kame.phtml"> Kame as a WAVEsec - client.</A></P> -<P><A HREF="#kame.top">Back to chart</A></P> -<H4><A NAME="mcafee">PGPNet/McAfee</A></H4> -<P></P> -<UL> -<LI>Now called McAfee VPN Client.</LI> -<LI>PGPNet also came in a freeware version which did not support subnets</LI> -<LI>To support dhcp-over-ipsec, you need the X.509 patch, which is - included in<A HREF="http://www.freeswan.ca"> Super FreeS/WAN</A>.</LI> -</UL> -<P><A HREF="http://www.freeswan.ca/docs/WindowsInterop"> Tim Carr's - Windows Interop Guide (X.509)</A> -<BR><A HREF="http://www.rommel.stw.uni-erlangen.de/~hshoexer/ipsec-howto/HOWTO.html#Interop2"> - Hans-Joerg Hoexer's Guide for Linux-PGPNet (PSK)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/04/msg00339.html"> - Kai Martius' instructions using RSA Key-Extractor Tool (RSA)</A> -<BR> <A HREF="http://www.zengl.net/freeswan/english.html">Christian - Zeng's page (RSA)</A> based on Kai's work. English or German. -<BR><A HREF="http://tirnanog.ls.fi.upm.es/CriptoLab/Biblioteca/InfTech/InfTech_CriptoLab.htm"> - Oscar Delgado's PDF (X.509, no configs)</A> -<BR><A HREF="http://www-ec.njit.edu/~rxt1077/Howto.txt"> Ryan's HOWTO - for FreeS/WAN-PGPNet (X.509)</A>. Through a Linksys Router with IPsec - Passthru enabled. -<BR><A HREF="http://jixen.tripod.com/#RW-PGP-to-Fwan"> Jean-Francois - Nadeau's Practical Configuration (Road Warrior with PSK)</A> -<BR><A HREF="http://www.evolvedatacom.nl/freeswan.html#toc"> Wouter - Prins' HOWTO (Road Warrior with X.509)</A> -<BR></P> -<P><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/01/msg00271.html"> - Rekeying problem with FreeS/WAN and older PGPNets</A> -<BR></P> -<P><A HREF="http://www.strongsec.com/freeswan/dhcprelay/index.htm"> DHCP - over IPSEC HOWTO for FreeS/WAN (requires X.509 and dhcprelay patches)</A> -</P> -<P><A HREF="#mcafee.top">Back to chart</A></P> -<H4><A NAME="microsoft">Microsoft Windows 2000/XP</A></H4> -<UL> -<LI>IPsec comes with Win2k, and with XP Support Tools. May require<A HREF="http://www.microsoft.com/windows2000/downloads/recommended/encryption/default.asp"> - High Encryption Pack</A>. WinXP users have also reported better results - with Service Pack 1.</LI> -<LI>The Road Warrior setup works either way round. Windows (XP or 2K) - IPsec can connect as a Road Warrior to FreeS/WAN. However, FreeS/WAN - can also successfully connect as a Road Warrior to Windows IPsec (see - Nate Carlson's configs below).</LI> -<LI>FreeS/WAN version 1.92 or later is required to avoid an - interoperation problem with Windows native IPsec. Earlier FreeS/WAN - versions did not process the Commit Bit as Windows native IPsec - expected.</LI> -</UL> -<P><A HREF="http://www.freeswan.ca/docs/WindowsInterop"> Tim Carr's - Windows Interop Guide (X.509)</A> -<BR><A HREF="http://ipsec.math.ucla.edu/services/ipsec.html"> James - Carter's instructions (X.509, NAT-T)</A> -<BR><A HREF="http://jixen.tripod.com/#Win2000-Fwan"> Jean-Francois - Nadeau's Net-net Configuration (PSK)</A> -<BR><A HREF="http://security.nta.no/freeswan-w2k.html"> Telenor's - Node-node Config (Transport-mode PSK)</A> -<BR><A HREF="http://vpn.ebootis.de"> Marcus Mueller's HOWTO using his - VPN config tool (X.509).</A> Tool also works with PSK. -<BR><A HREF="http://www.natecarlson.com/include/showpage.php?cat=linux&page=ipsec-x509"> - Nate Carlson's HOWTO using same tool (Road Warrior with X.509)</A>. - Unusually, FreeS/WAN is the Road Warrior here. -<BR><A HREF="http://tirnanog.ls.fi.upm.es/CriptoLab/Biblioteca/InfTech/InfTech_CriptoLab.htm"> - Oscar Delgado's PDF (X.509, no configs)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2003-July/022425.html"> - Tim Scannell's Windows XP Additional Checklist (X.509)</A> -<BR></P> - -<!-- Note to self: Include L2TP references? --> -<P><A HREF="http://www.microsoft.com/windows2000/en/server/help/default.asp?url=/windows2000/en/server/help/sag_TCPIP_ovr_secfeatures.htm"> - Microsoft's page on Win2k TCP/IP security features</A> -<BR><A HREF="http://support.microsoft.com/support/kb/articles/Q257/2/25.ASP"> - Microsoft's Win2k IPsec debugging tips</A> -<BR> -<!-- Alt-URL http://support.microsoft.com/default.aspx?scid=kb;EN-US;q257225 -Perhaps newer? --> -<A HREF="http://www.wired.com/news/technology/0,1282,36336,00.html"> - MS VPN may fall back to 1DES</A></P> -<P><A HREF="#microsoft.top">Back to chart</A></P> -<H4><A NAME="ssh">SSH Sentinel</A></H4> -<UL> -<LI>Popular and well tested.</LI> -<LI>Also rebranded in<A HREF="http://www.zyxel.com"> Zyxel Zywall</A>. - Our Zyxel interop notes are<A HREF="#zyxel"> here</A>.</LI> -<LI> SSH supports IPsec-over-UDP NAT traversal.</LI> -<LI>There is this<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/12/msg00370.html"> - potential problem</A> if you're not using the Legacy Proposal option.</LI> -</UL> -<P><A HREF="http://www.ssh.com/support/sentinel/documents.cfm"> SSH's - Sentinel-FreeSWAN interop PDF (X.509)</A> -<BR><A HREF="http://www.nadmm.com/show.php?story=articles/vpn.inc"> - Nadeem Hassan's SUSE-to-Sentinel article (Road warrior with X.509)</A> -<BR><A HREF="http://www.zerozone.it/documents/Linux/HowTo/VPN-IPsec-Freeswan-HOWTO.html"> - O-Zone's Italian HOWTO (Road Warrior, X.509, DHCP)</A> -<BR></P> -<P><A HREF="#ssh.top">Back to chart</A></P> -<H4><A NAME="safenet">Safenet SoftPK/SoftRemote</A></H4> -<UL> -<LI>People recommend SafeNet as a low cost Windows client.</LI> -<LI>SoftRemote seems to be the newer name for SoftPK.</LI> -</UL> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005061.html"> - Whit Blauvelt's SoftRemote tips</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-October/015591.html"> - Tim Wilson's tips (X.509)</A><A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00607.html"> - Workaround for a "gotcha"</A></P> -<P><A HREF="http://jixen.tripod.com/#Rw-IRE-to-Fwan"> Jean-Francois - Nadeau's Practical Configuration (Road Warrior with PSK)</A> -<BR><A HREF="http://www.terradoncommunications.com/security/whitepapers/safe_net-to-free_swan.pdf"> - Terradon Communications' PDF (Road Warrior with PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-October/?????.html"> - Seaan.net's PDF (Road Warrior to Subnet, with PSK)</A> -<BR><A HREF="http://www.redbaronconsulting.com/freeswan/fswansafenet.pdf"> - Red Baron Consulting's PDF (Road Warrior with X.509)</A></P> -<P><A HREF="#safenet.top">Back to chart</A></P> -<H3><A NAME="10_3_2">For<EM> Other Implementations</EM></A></H3> -<H4><A NAME="6wind">6Wind</A></H4> -<P><A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> - French page with configs (X.509)</A></P> -<P><A HREF="#6wind.top">Back to chart</A></P> -<H4><A NAME="alcatel">Alcatel Timestep</A></H4> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-June/011878.html"> - Alain Sabban's settings (PSK or PSK road warrior; through static NAT)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/1999/06/msg00100.html"> - Derick Cassidy's configs (PSK)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/1999/08/msg00194.html"> - David Kerry's Timestep settings (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-August/013711.html"> - Kevin Gerbracht's ipsec.conf (X.509)</A></P> -<P><A HREF="#alcatel.top">Back to chart</A></P> -<H4><A NAME="apple">Apple Macintosh System 10+</A></H4> -<UL> -<LI>Since the system is based on FreeBSD, this should interoperate<A HREF="#kame"> - just like FreeBSD</A>.</LI> -<LI> To use Appletalk over IPsec tunnels,<A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005116.html"> - run it over TCP/IP</A>, or use Open Door Networks' Shareway IP tool,<A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005426.html"> - described here.</A></LI> -<LI>See also the<A HREF="#equinux"> Equinux VPN Tracker</A> for Mac OS - X.</LI> -</UL> -<P><A HREF="http://ipsec.math.ucla.edu/services/ipsec.html"> James - Carter's instructions (X.509, NAT-T)</A></P> -<P><A HREF="#apple.top">Back to chart</A></P> -<H4><A NAME="ashleylaurent">AshleyLaurent VPCom</A></H4> -<P><A HREF="http://www.ashleylaurent.com/newsletter/01-28-00.htm"> - Successful interop report, no details</A></P> -<P><A HREF="#ashleylaurent.top">Back to chart</A></P> -<H4><A NAME="borderware">Borderware</A></H4> -<UL> -<LI>I suspect the Borderware client is a rebranded Safenet. If that's - true, our<A HREF="#safenet"> Safenet section</A> will help.</LI> -</UL> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-March/008288.html"> - Philip Reetz' configs (PSK)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/09/msg00217.html"> - Borderware server does not support FreeS/WAN road warriors</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-February/007733.html"> - Older Borderware may not support Diffie Hellman groups 2, 5</A> -<BR></P> -<P><A HREF="#borderware.top">Back to chart</A></P> -<H4><A NAME="checkpoint">Check Point VPN-1 or FW-1</A></H4> -<UL> -<LI><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00099.html"> - Caveat about IP-range inclusion on Check Point.</A></LI> -<LI> Some versions of Check Point may require an aggressive mode patch - to interoperate with FreeS/WAN. -<BR><A HREF="http://www.freeswan.ca/code/super-freeswan"> Super - FreeS/WAN</A> now features this patch. -<!-- -<A HREF="http://www.freeswan.ca/patches/aggressivemode">Steve Harvey's -aggressive mode patch for FreeS/WAN 1.5</A> ---> -</LI> -<LI></LI> -<LI>A Linux FreeS/WAN-Checkpoint connection may close after some time. - Try<A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00293.html"> - this tip</A> toward a workaround.</LI> -</UL> -<P><A HREF="http://www.fw-1.de/aerasec/ng/vpn-freeswan/CPNG+Linux-FreeSWAN.html"> - AERAsec's Firewall-1 NG site (PSK, X.509, Road Warrior with X.509, - other algorithms)</A> -<BR> <A HREF="http://www.fw-1.de/aerasec/ng/vpn-freeswan/CPNG+Linux-FreeSWAN.html#support-matrix"> - AERAsec's detailed Check Point-FreeS/WAN support matrix</A> -<BR><A HREF="http://support.checkpoint.com/kb/docs/public/firewall1/4_1/pdf/fw-linuxvpn.pdf"> - Checkpoint.com PDF: Linux as a VPN Client to FW-1 (PSK)</A> -<BR><A HREF="http://www.phoneboy.com"> PhoneBoy's Check Point FAQ (on - Check Point only, not FreeS/WAN)</A> -<BR></P> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2001-August/002351.html"> - Chris Harwell's tips FreeS/WAN configs (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-April/009362.html"> - Daniel Tombeil's configs (PSK)</A></P> -<P><A HREF="#checkpoint.top">Back to chart</A></P> -<H4><A NAME="cisco">Cisco</A></H4> -<UL> -<LI> Cisco supports IPsec-over-UDP NAT traversal.</LI> -<LI>Cisco VPN Client appears to use nonstandard IPsec and does not work - with FreeS/WAN.<A HREF="https://mj2.freeswan.org/archives/2003-August/maillist.html"> - This message</A> concerns Cisco VPN Client 4.01. -<!-- fix link --> -</LI> -<LI>A Linux FreeS/WAN-Cisco connection may close after some time.<A HREF="http://lists.freeswan.org/pipermail/users/2001-December/005758.html"> - Here</A> is a workaround, and<A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00293.html"> - here</A> is another comment on the same subject.</LI> -<LI><A HREF="http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t2/3desips.htm"> -Older Ciscos</A> purchased outside the United States may not have 3DES, - which FreeS/WAN requires.</LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2001-June/000406.html"> -RSA keying may not be possible between Cisco and FreeS/WAN.</A></LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2001-October/004357.html"> -In ipsec.conf, VPN3000 DN (distinguished name) must be in binary (X.509 - only)</A></LI> -</UL> -<P><A HREF="http://rr.sans.org/encryption/cisco_router.php"> SANS - Institute HOWTO (PSK).</A> Detailed, with extensive references. -<BR><A HREF="http://www.worldbank.ro/IPSEC/cisco-linux.txt"> Short HOWTO - (PSK)</A> -<BR><A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> - French page with configs for Cisco IOS, PIX and VPN 3000 (X.509)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2001-August/002966.html"> - Dave McFerren's sample configs (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2001-September/003422.html"> - Wolfgang Tremmel's sample configs (PSK road warrior)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/11/msg00578.html"> - Old doc from Pete Davis, with William Watson's updated Tips (PSK)</A> -<BR></P> -<P><STRONG>Some PIX specific information:</STRONG> -<BR><A HREF="http://www.wlug.org.nz/FreeSwanToCiscoPix"> Waikato Linux - Users' Group HOWTO. Nice detail (PSK)</A> -<BR><A HREF="http://www.johnleach.co.uk/documents/freeswan-pix/freeswan-pix.html"> - John Leach's configs (PSK)</A> -<BR><A HREF="http://www.diverdown.cc/vpn/freeswanpix.html"> Greg - Robinson's settings (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-February/007901.html"> - Scott's ipsec.conf for PIX (PSK, FreeS/WAN side only)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2001-October/003949.html"> - Rick Trimble's PIX and FreeS/WAN settings (PSK)</A> -<BR></P> -<P><A href="http://www.cisco.com/public/support/tac"> Cisco VPN support - page</A> -<BR><A href="http://www.ieng.com/warp/public/707/index.shtml#ipsec"> - Cisco IPsec information page</A></P> -<P><A HREF="#cisco.top">Back to chart</A></P> -<H4><A NAME="equinux">Equinux VPN tracker (for Mac OS X)</A></H4> -<UL> -<LI>Graphical configurator for Mac OS X IPsec. May be an interface to - the<A HREF="#apple"> native Mac OS X IPsec</A>, which is essentially<A HREF="#kame"> - KAME</A>.</LI> -<LI>To use Appletalk over IPsec tunnels,<A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005116.html"> - run it over TCP/IP</A>, or use Open Door Networks' Shareway IP tool,<A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005426.html"> - described here.</A></LI> -</UL> -<P> Equinux provides<A HREF="http://www.equinux.com/download/HowTo_FreeSWAN.pdf"> - this excellent interop PDF</A> (PSK, RSA, X.509).</P> -<P><A HREF="#equinux.top">Back to chart</A></P> -<H4><A NAME="fsecure">F-Secure</A></H4> -<UL> -<LI> -<!-- <A HREF="http://lists.freeswan.org/pipermail/users/2002-February/007596.html"> --> - F-Secure supports IPsec-over-UDP NAT traversal.</LI> -</UL> -<P><A HREF="http://www.pingworks.de/tech/vpn/vpn.txt">pingworks.de's - "Connecting F-Secure's VPN+ to Linux FreeS/WAN" (PSK road warrior)</A> -<BR> <A HREF="http://www.pingworks.de/tech/vpn/vpn.pdf">Same thing - as PDF</A> -<BR><A HREF="http://www.exim.org/pipermail/linux-ipsec/Week-of-Mon-20010122/000061.html"> - Success report, no detail (PSK)</A> -<BR><A HREF="http://www.exim.org/pipermail/linux-ipsec/Week-of-Mon-20010122/000041.html"> - Success report, no detail (Manual)</A></P> - -<!-- Other NAT traversers: -http://lists.freeswan.org/pipermail/users/2002-April/009136.html -and ssh sentinel: -http://lists.freeswan.org/pipermail/users/2001-September/003108.html ---> -<P><A HREF="#fsecure.top">Back to chart</A></P> -<H4><A NAME="gauntlet">Gauntlet GVPN</A></H4> -<P><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/11/msg00535.html"> - Richard Reiner's ipsec.conf (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-June/011434.html"> - Might work without that pesky firewall... (PSK)</A> -<BR> -<!-- insert archive link --> - In late July, 2003 Alexandar Antik reported success interoperating - with Gauntlet 6.0 for Solaris (X.509). Unfortunately the message is not - properly archived at this time.</P> -<P><A HREF="#gauntlet.top">Back to chart</A></P> -<H4><A NAME="aix">IBM AIX</A></H4> -<P><A HREF="http://www-1.ibm.com/servers/esdd/articles/security.html"> - IBM's "Built-In Network Security with AIX" (PSK, X.509)</A> -<BR><A HREF="http://www-1.ibm.com/servers/aix/products/ibmsw/security/vpn/faqandtips/#ques20"> - IBM's tip: importing Linux FreeS/WAN settings into AIX's<VAR> ikedb</VAR> - (PSK)</A></P> -<P><A HREF="#aix.top">Back to chart</A></P> -<H4><A NAME="as400">IBM AS/400</A></H4> -<UL> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2002-April/009106.html"> - Road Warriors may act flaky</A>.</LI> -</UL> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-September/014264.html"> - Richard Welty's tips and tricks</A> -<BR></P> -<P><A HREF="#as400.top">Back to chart</A></P> -<H4><A NAME="intel">Intel Shiva LANRover / Net Structure</A></H4> -<UL> -<LI>Intel Shiva LANRover is now known as Intel Net Structure.</LI> -<LI><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/01/msg00298.html"> - Shiva seems to have two modes: IPsec or the proprietary "Shiva Tunnel".</A> - Of course, FreeS/WAN will only create IPsec tunnels.</LI> -<LI><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00293.html"> - AH may not work for Shiva-FreeS/WAN.</A> That's OK, since FreeS/WAN has - phased out the use of AH.</LI> -</UL> -<P><A HREF="http://snowcrash.tdyc.com/freeswan/"> Snowcrash's configs - (PSK)</A> -<BR><A HREF="http://www.opus1.com/vpn/index.html"> Old configs from an - interop (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2001-October/003831.html"> - The day Shiva tickled a Pluto bug (PSK)</A> -<BR> <A HREF="http://lists.freeswan.org/pipermail/users/2001-October/004270.html"> - Follow up: success!</A></P> -<P><A HREF="#intel.top">Back to chart</A></P> -<H4><A NAME="lancom">LanCom (formerly ELSA)</A></H4> -<UL> -<LI>This router is popular in Germany.</LI> -</UL> -<P> Jakob Curdes successfully created a PSK connection with the LanCom - 1612 in August 2003. -<!-- add ML link when it appears --> -</P> -<P><A HREF="#lancom.top">Back to chart</A></P> -<H4><A NAME="linksys">Linksys</A></H4> -<UL> -<LI>Linksys may be used as an IPsec tunnel endpoint,<STRONG> OR</STRONG> - as a router in "IPsec passthrough" mode, so that the IPsec tunnel - passes through the Linksys.</LI> -</UL> -<H5>As tunnel endpoint</H5> -<P><A HREF="http://www.freeswan.ca/docs/BEFVP41/"> Ken Bantoft's - instructions (Road Warrior with PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-February/007814.html"> - Nate Carlson's caveats</A></P> -<H5>In IPsec passthrough mode</H5> -<P><A HREF="http://www-ec.njit.edu/~rxt1077/Howto.txt"> Sample HOWTO - through a Linksys Router</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2002/02/msg00114.html"> - Nadeem Hasan's configs</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2002/02/msg00180.html"> - Brock Nanson's tips</A> -<BR></P> -<P><A HREF="#linksys.top">Back to chart</A></P> -<H4><A NAME="lucent">Lucent</A></H4> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-May/010976.html"> - Partial success report; see also the next message in thread</A></P> - -<!-- section done --> -<P><A HREF="#lucent.top">Back to chart</A></P> -<H4><A NAME="netasq">Netasq</A></H4> -<P><A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> - French page with configs (X.509)</A></P> - -<!-- section done --> -<P><A HREF="#netasq.top">Back to chart</A></P> -<H4><A NAME="netcelo">Netcelo</A></H4> -<P><A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> - French page with configs (X.509)</A> -<!-- section done --> -</P> -<P><A HREF="#netcelo.top">Back to chart</A></P> -<H4><A NAME="netgear">Netgear fvs318</A></H4> -<UL> -<LI>With a recent Linux FreeS/WAN, you will require the latest (12/2002) - Netgear firmware, which supports Diffie-Hellman (DH) group 2. For - security reasons, we phased out DH 1 after Linux FreeS/WAN 1.5.</LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2002-June/011833.html"> - This message</A> reports the incompatibility between Linux FreeS/WAN - 1.6+ and Netgear fvs318 without the firmware upgrade.</LI> -<LI>We believe Linux FreeS/WAN 1.5 and earlier will interoperate with - any NetGear firmware.</LI> -</UL> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2003-February/017891.html"> - John Morris' setup (PSK)</A></P> -<P><A HREF="#netgear.top">Back to chart</A></P> -<H4><A NAME="netscreen">Netscreen 100 or 5xp</A></H4> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-August/013409.html"> - Errol Neal's settings (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-October/015265.html"> - Corey Rogers' configs (PSK, no PFS)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-August/013051.html"> - Jordan Share's configs (PSK, 2 subnets, through static NAT)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/08/msg00404.html"> - Set src proxy_id to your protected subnet/mask</A> -<BR><A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> - French page with ipsec.conf, Netscreen screen shots (X.509, may need to - revert to PSK...)</A></P> -<P><A HREF="http://archives.neohapsis.com/archives/sf/linux/2001-q2/0123.html"> - A report of a company using Netscreen with FreeS/WAN on a large scale - (FreeS/WAN road warriors?)</A></P> -<P><A HREF="#netscreen.top">Back to chart</A></P> -<H4><A NAME="nortel">Nortel Contivity</A></H4> -<UL> -<LI> Nortel supports IPsec-over-UDP NAT traversal.</LI> -<LI><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00417.html"> - Some older versions of Contivity and FreeS/WAN will not communicate.</A> -</LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2002-May/010924.html"> - FreeS/WAN cannot be used as a "client" to a Nortel Contivity server, - but can be used as a branch-office tunnel.</A></LI> - -<!-- Probably obsoleted by Ken's post -<LI> -(Matthias siebler from old interop) -At one point you could not configure Nortel-FreeS/WAN tunnels as -"Client Tunnels" since FreeS/WAN does not support Aggressive Mode. -Current status of this problem: unknown. -<LI> -<A HREF="http://lists.freeswan.org/pipermail/users/2001-November/004612.html"> -How do we map group and user passwords onto the data that FreeS/WAN wants? -</A> -</LI> ---> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2002-October/015455.html"> - Contivity does not send Distinguished Names in the order FS wants them - (X.509).</A></LI> -<LI><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/03/msg00137.html"> - Connections may time out after 30-40 minutes idle.</A></LI> -</UL> -<P><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/03/msg00137.html"> - JJ Streicher-Bremer's mini HOWTO for old new software. (PSK with two - subnets)</A> -<BR><A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> - French page with configs (X.509)</A>. This succeeds using the above - X.509 tip.</P> - -<!-- I could do more searching but this is a solid start. --> -<P><A HREF="#nortel.top">Back to chart</A></P> -<H4><A NAME="radguard">Radguard</A></H4> -<P><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/05/msg00009.html"> - Marko Hausalo's configs (PSK).</A> Note: These do create a connection, - as you can see by "IPsec SA established". -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-October/???.html"> - Claudia Schmeing's comments</A></P> -<P><A HREF="#radguard.top">Back to chart</A></P> -<H4><A NAME="raptor">Raptor (NT or Solaris)</A></H4> -<P></P> -<UL> -<LI>Now known as Symantec Enterprise Firewall.</LI> -<LI>The Raptor does not normally come with X.509, but this may be - available as an add-on.</LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2002-May/010256.html"> - Raptor requires alphanumberic PSK values, whereas FreeS/WAN uses hex.</A> -</LI> -<LI>Raptor's tunnel endpoint may be a host, subnet or group of subnets - (see<A HREF="http://lists.freeswan.org/pipermail/design/2001-November/001295.html"> - this message</A> ). FreeS/WAN cannot handle the group of subnets; you - must create separate connections for each in order to interoperate.</LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2002-May/010113.html"> - Some versions of Raptor accept only single DES.</A> According to this - German message,<A HREF="http://radawana.cg.tuwien.ac.at/mail-archives/lll/200012/msg00065.html"> - the Raptor Mobile Client demo offers single DES only.</A></LI> -</UL> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-January/006935.html"> - Peter Mazinger's settings (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005522.html"> - Peter Gerland's configs (PSK)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/07/msg00597.html"> - Charles Griebel's configs (PSK).</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-July/012275.html"> - Lumir Srch's tips (PSK)</A></P> -<P><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/05/msg00214.html"> - John Hardy's configs (Manual)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/01/msg00236.html"> - Older Raptors want 3DES keys in 3 parts (Manual).</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/06/msg00480.html"> - Different keys for each direction? (Manual)</A> -<BR></P> -<P><A HREF="#raptor.top">Back to chart</A></P> -<H4><A NAME="redcreek">Redcreek Ravlin</A></H4> -<UL> -<LI>Known issue #1: The Ravlin expects a quick mode renegotiation right - after every Main Mode negotiation.</LI> -<LI> Known issue #2: The Ravlin tries to negotiate a zero connection - lifetime, which it takes to mean "infinite".<A HREF="http://www.bear-cave.org.uk/linux/ravlin/"> - Jim Hague's patch</A> addresses both issues.</LI> -<LI><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/03/msg00191.html"> - Interop works with Ravlin Firmware > 3.33. Includes tips (PSK).</A></LI> -</UL> -<P><A HREF="#redcreek.top">Back to chart</A></P> -<H4><A NAME="sonicwall">SonicWall</A></H4> -<UL> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2001-June/000998.html"> - Sonicwall cannot be used for Road Warrior setups</A></LI> -<LI> At one point,<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/05/msg00217.html"> - only Sonicwall PRO supported triple DES</A>.</LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2002-March/008600.html"> - Older Sonicwalls (before Nov 2001) feature Diffie Hellman group 1 only</A> -.</LI> -</UL> -<P><A HREF="http://www.xinit.cx/docs/freeswan.html"> Paul Wouters' - config (PSK)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00073.html"> - Dilan Arumainathan's configuration (PSK)</A> -<BR><A HREF="http://www.gravitas.co.uk/vpndebug"> Dariush's setup... - only opens one way (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2003-July/022302.html"> - Andreas Steffen's tips (X.509)</A> -<BR></P> -<P><A HREF="#sonicwall.top">Back to chart</A></P> -<H4><A NAME="sun">Sun Solaris</A></H4> -<UL> -<LI> Solaris 8+ has a native (in kernel) IPsec implementation.</LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2002-May/010503.html"> - Solaris does not seem to support tunnel mode, but you can make IP-in-IP - tunnels instead, like this.</A></LI> -</UL> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2003-June/022216.html"> - Reports of some successful interops</A> from a fellow @sun.com. See - also<A HREF="http://lists.freeswan.org/pipermail/users/2003-July/022247.html"> - these follow up posts</A>. -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/03/msg00332.html"> - Aleks Shenkman's configs (Manual in transport mode)</A> -<BR> -<!--sparc 64 stuff goes where?--> -</P> -<P><A HREF="#solaris.top">Back to chart</A></P> -<H4><A NAME="symantec">Symantec</A></H4> -<UL> -<LI>The Raptor, covered<A HREF="#raptor"> above</A>, is now known as - Symantec Enterprise Firewall.</LI> -<LI>Symantec's "distinguished name" is a KEY_ID. See Andreas Steffen's - post, below.</LI> -</UL> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-April/009037.html"> - Andreas Steffen's configs for Symantec 200R (PSK)</A></P> -<P><A HREF="#symantec.top">Back to chart</A></P> -<H4><A NAME="watchguard">Watchguard Firebox</A></H4> -<UL> -<LI>Automatic keying works with WatchGuard 5.0+ only.</LI> -<LI>Seen to interoperate with WatchGuard 1000, II, III; firmware v. 5, - 6..</LI> -<LI>For manual keying, Watchguard's Policy Manager expects SPI numbers - and encryption and authentication keys in decimal (not hex).</LI> -</UL> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-July/012595.html"> - WatchGuard's HOWTO (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-August/013342.html"> - Ronald C. Riviera's Settings (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00179.html"> - Walter Wickersham's Notes (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-October/015587.html"> - Max Enders' Configs (Manual)</A></P> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-April/009404.html"> - Old known issue with auto keying</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00124.html"> - Tips on key generation and format (Manual)</A> -<BR></P> -<P><A HREF="#watchguard.top">Back to chart</A></P> -<H4><A NAME="xedia">Xedia Access Point/QVPN</A></H4> -<P><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/12/msg00520.html"> - Hybrid IPsec/L2TP connection settings (X.509)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/ipsec/1999/08/msg00140.html"> - Xedia's LAN-LAN links don't use multiple tunnels</A> -<BR> <A HREF="http://www.sandelman.ottawa.on.ca/ipsec/1999/08/msg00140.html"> - That explanation, continued</A></P> -<P><A HREF="#xedia.top">Back to chart</A></P> -<H4><A NAME="zyxel">Zyxel</A></H4> -<UL> -<LI>The Zyxel Zywall is a rebranded SSH Sentinel box. See also our - section on<A HREF="#ssh"> SSH</A>.</LI> -<LI>There seems to be a problem with keeping this connection alive. This - is caused at the Zyxel end. See this brief<A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00141.html"> - discussion and solution.</A></LI> -</UL> -<P><A HREF="http://www.zyxel.com/support/supportnote/zywall/app/zw_freeswan.htm"> - Zyxel's Zywall to FreeS/WAN instructions (PSK)</A> -<BR><A HREF="http://www.zyxel.com/support/supportnote/p652/app/zw_freeswan.htm"> - Zyxel's Prestige to FreeS/WAN instructions (PSK)</A>. Note: not all - Prestige versions include VPN software. -<BR><A HREF="http://www.lancry.net/techdocs/freeswan-zyxel.txt"> Fabrice - Cahen's HOWTO (PSK)</A> -<BR> </P> -<P><A HREF="#zyxel.top">Back to chart</A></P> - -<!-- SAMPLE ENTRY - -<H4><A NAME="timestep">Timestep</A></H4> - -<P>Text goes here. -</P> - ---> -<HR> -<H1><A name="performance">Performance of FreeS/WAN</A></H1> - The performance of FreeS/WAN is adequate for most applications. -<P>In normal operation, the main concern is the overhead for encryption, - decryption and authentication of the actual IPsec (<A href="#ESP">ESP</A> - and/or<A href="#AH"> AH</A>) data packets. Tunnel setup and rekeying - occur so much less frequently than packet processing that, in general, - their overheads are not worth worrying about.</P> -<P>At startup, however, tunnel setup overheads may be significant. If - you reboot a gateway and it needs to establish many tunnels, expect - some delay. This and other issues for large gateways are discussed<A href="#biggate"> - below</A>.</P> -<H2><A name="pub.bench">Published material</A></H2> -<P>The University of Wales at Aberystwyth has done quite detailed speed - tests and put<A href="http://tsc.llwybr.org.uk/public/reports/SWANTIME/"> - their results</A> on the web.</P> -<P>Davide Cerri's<A href="http://www.linux.it/~davide/doc/"> thesis (in - Italian)</A> includes performance results for FreeS/WAN and for<A href="#TLS"> - TLS</A>. He posted an<A href="http://lists.freeswan.org/pipermail/users/2001-December/006303.html"> - English summary</A> on the mailing list.</P> -<P>Steve Bellovin used one of AT&T Research's FreeS/WAN gateways as his - data source for an analysis of the cache sizes required for key - swapping in IPsec. Available as<A href="http://www.research.att.com/~smb/talks/key-agility.email.txt"> - text</A> or<A href="http://www.research.att.com/~smb/talks/key-agility.pdf"> - PDF slides</A> for a talk on the topic.</P> -<P>See also the NAI work mentioned in the next section.</P> -<H2><A name="perf.estimate">Estimating CPU overheads</A></H2> -<P>We can come up with a formula that roughly relates CPU speed to the - rate of IPsec processing possible. It is far from exact, but should be - usable as a first approximation.</P> -<P>An analysis of authentication overheads for high-speed networks, - including some tests using FreeS/WAN, is on the<A href="http://www.pgp.com/research/nailabs/cryptographic/adaptive-cryptographic.asp"> - NAI Labs site</A>. In particular, see figure 3 in this<A href="http://download.nai.com/products/media/pgp/pdf/acsa_final_report.pdf"> - PDF document</A>. Their estimates of overheads, measured in Pentium II - cycles per byte processed are:</P> -<TABLE align="center" border="1"><TBODY></TBODY> -<TR><TH></TH><TH>IPsec</TH><TH>authentication</TH><TH>encryption</TH><TH> -cycles/byte</TH></TR> -<TR><TD>Linux IP stack alone</TD><TD>no</TD><TD>no</TD><TD>no</TD><TD align="right"> -5</TD></TR> -<TR><TD>IPsec without crypto</TD><TD>yes</TD><TD>no</TD><TD>no</TD><TD align="right"> -11</TD></TR> -<TR><TD>IPsec, authentication only</TD><TD>yes</TD><TD>SHA-1</TD><TD>no</TD><TD -align="right">24</TD></TR> -<TR><TD>IPsec with encryption</TD><TD>yes</TD><TD>yes</TD><TD>yes</TD><TD -align="right">not tested</TD></TR> -</TABLE> -<P>Overheads for IPsec with encryption were not tested in the NAI work, - but Antoon Bosselaers'<A href="http://www.esat.kuleuven.ac.be/~bosselae/fast.html"> - web page</A> gives cost for his optimised Triple DES implementation as - 928 Pentium cycles per block, or 116 per byte. Adding that to the 24 - above, we get 140 cycles per byte for IPsec with encryption.</P> -<P>At 140 cycles per byte, a 140 MHz machine can handle a megabyte -- 8 - megabits -- per second. Speeds for other machines will be proportional - to this. To saturate a link with capacity C megabits per second, you - need a machine running at<VAR> C * 140/8 = C * 17.5</VAR> MHz.</P> -<P>However, that estimate is not precise. It ignores the differences - between:</P> -<UL> -<LI>NAI's test packets and real traffic</LI> -<LI>NAI's Pentium II cycles, Bosselaers' Pentium cycles, and your - machine's cycles</LI> -<LI>different 3DES implementations</LI> -<LI>SHA-1 and MD5</LI> -</UL> -<P>and does not account for some overheads you will almost certainly - have:</P> -<UL> -<LI>communication on the client-side interface</LI> -<LI>switching between multiple tunnels -- re-keying, cache reloading and - so on</LI> -</UL> -<P>so we suggest using<VAR> C * 25</VAR> to get an estimate with a bit - of a built-in safety factor.</P> -<P>This covers only IP and IPsec processing. If you have other loads on - your gateway -- for example if it is also working as a firewall -- then - you will need to add your own safety factor atop that.</P> -<P>This estimate matches empirical data reasonably well. For example, - Metheringham's tests, described<A href="#klips.bench"> below</A>, show - a 733 topping out between 32 and 36 Mbit/second, pushing data as fast - as it can down a 100 Mbit link. Our formula suggests you need at least - an 800 to handle a fully loaded 32 Mbit link. The two results are - consistent.</P> -<P>Some examples using this estimation method:</P> -<TABLE align="center" border="1"><TBODY></TBODY> -<TR><TH colspan="2">Interface</TH><TH colspan="3">Machine speed in MHz</TH> -</TR> -<TR><TH>Type</TH><TH>Mbit per -<BR> second</TH><TH>Estimate -<BR> Mbit*25</TH><TH>Minimum IPSEC gateway</TH><TH>Minimum with other - load -<P>(e.g. firewall)</P> -</TH></TR> -<TR><TD>DSL</TD><TD align="right">1</TD><TD align="right">25 MHz</TD><TD rowspan="2"> -whatever you have</TD><TD rowspan="2">133, or better if you have it</TD></TR> -<TR><TD>cable modem</TD><TD align="right">3</TD><TD align="right">75 MHz</TD> -</TR> -<TR><TD><STRONG>any link, light load</STRONG></TD><TD align="right"><STRONG> -5</STRONG></TD><TD align="right">125 MHz</TD><TD>133</TD><TD>200+,<STRONG> - almost any surplus machine</STRONG></TD></TR> -<TR><TD>Ethernet</TD><TD align="right">10</TD><TD align="right">250 MHz</TD><TD> -surplus 266 or 300</TD><TD>500+</TD></TR> -<TR><TD><STRONG>fast link, moderate load</STRONG></TD><TD align="right"><STRONG> -20</STRONG></TD><TD align="right">500 MHz</TD><TD>500</TD><TD>800+,<STRONG> - any current off-the-shelf PC</STRONG></TD></TR> -<TR><TD>T3 or E3</TD><TD align="right">45</TD><TD align="right">1125 MHz</TD><TD> -1200</TD><TD>1500+</TD></TR> -<TR><TD>fast Ethernet</TD><TD align="right">100</TD><TD align="right"> -2500 MHz</TD><TD align="center" colspan="2" rowspan="2">// not feasible - with 3DES in software on current machines //</TD></TR> -<TR><TD>OC3</TD><TD align="right">155</TD><TD align="right">3875 MHz</TD> -</TR> -</TABLE> -<P>Such an estimate is far from exact, but should be usable as minimum - requirement for planning. The key observations are:</P> -<UL> -<LI>older<STRONG> surplus machines</STRONG> are fine for IPsec gateways - at loads up to<STRONG> 5 megabits per second</STRONG> or so</LI> -<LI>a<STRONG> mid-range new machine</STRONG> can handle IPsec at rates - up to<STRONG> 20 megabits per second</STRONG> or more</LI> -</UL> -<H3><A name="perf.more">Higher performance alternatives</A></H3> -<P><A href="#AES">AES</A> is a new US government block cipher standard, - designed to replace the obsolete<A href="#DES"> DES</A>. If FreeS/WAN - using<A href="#3DES"> 3DES</A> is not fast enough for your application, - the AES<A href="#patch"> patch</A> may help.</P> -<P>To date (March 2002) we have had only one<A href="http://lists.freeswan.org/pipermail/users/2002-February/007771.html"> - mailing list report</A> of measurements with the patch applied. It - indicates that, at least for the tested load on that user's network,<STRONG> - AES roughly doubles IPsec throughput</STRONG>. If further testing - confirms this, it may prove possible to saturate an OC3 link in - software on a high-end box.</P> -<P>Also, some work is being done toward support of<A href="#hardware"> - hardware IPsec acceleration</A> which might extend the range of - requirements FreeS/WAN could meet.</P> -<H3><A NAME="11_2_2">Other considerations</A></H3> -<P>CPU speed may be the main issue for IPsec performance, but of course - it isn't the only one.</P> -<P>You need good ethernet cards or other network interface hardware to - get the best performance. See this<A href="http://www.ethermanage.com/ethernet/ethernet.html"> - ethernet information</A> page and this<A href="http://www.scyld.com/diag"> - Linux network driver</A> page.</P> -<P>The current FreeS/WAN kernel code is largely single-threaded. It is - SMP safe, and will run just fine on a multiprocessor machine (<A href="#multiprocessor"> -discussion</A>), but the load within the kernel is not shared - effectively. This means that, for example to saturate a T3 -- which - needs about a 1200 MHz machine -- you cannot expect something like a - dual 800 to do the job.</P> -<P>On the other hand, SMP machines do tend to share loads well so -- - provided one CPU is fast enough for the IPsec work -- a multiprocessor - machine may be ideal for a gateway with a mixed load.</P> -<H2><A name="biggate">Many tunnels from a single gateway</A></H2> -<P>FreeS/WAN allows a single gateway machine to build tunnels to many - others. There may, however, be some problems for large numbers as - indicated in this message from the mailing list:</P> -<PRE>Subject: Re: Maximum number of ipsec tunnels? - Date: Tue, 18 Apr 2000 - From: "John S. Denker" <jsd@research.att.com> - -Christopher Ferris wrote: - ->> What are the maximum number ipsec tunnels FreeS/WAN can handle?? - -Henry Spencer wrote: - ->There is no particular limit. Some of the setup procedures currently ->scale poorly to large numbers of connections, but there are (clumsy) ->workarounds for that now, and proper fixes are coming. - -1) "Large" numbers means anything over 50 or so. I routinely run boxes -with about 200 tunnels. Once you get more than 50 or so, you need to worry -about several scalability issues: - -a) You need to put a "-" sign in syslogd.conf, and rotate the logs daily -not weekly. - -b) Processor load per tunnel is small unless the tunnel is not up, in which -case a new half-key gets generated every 90 seconds, which can add up if -you've got a lot of down tunnels. - -c) There's other bits of lore you need when running a large number of -tunnels. For instance, systematically keeping the .conf file free of -conflicts requires tools that aren't shipped with the standard freeswan -package. - -d) The pluto startup behavior is quadratic. With 200 tunnels, this eats up -several minutes at every restart. I'm told fixes are coming soon. - -2) Other than item (1b), the CPU load depends mainly on the size of the -pipe attached, not on the number of tunnels. -</PRE> -<P>It is worth noting that item (1b) applies only to repeated attempts - to re-key a data connection (IPsec SA, Phase 2) over an established - keying connection (ISAKMP SA, Phase 1). There are two ways to reduce - this overhead using settings in<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A>:</P> -<UL> -<LI>set<VAR> keyingtries</VAR> to some small value to limit repetitions</LI> -<LI>set<VAR> keylife</VAR> to a short time so that a failing data - connection will be cleaned up when the keying connection is reset.</LI> -</UL> -<P>The overheads for establishing keying connections (ISAKMP SAs, Phase - 1) are lower because for these Pluto does not perform expensive - operations before receiving a reply from the peer.</P> -<P>A gateway that does a lot of rekeying -- many tunnels and/or low - settings for tunnel lifetimes -- will also need a lot of<A href="#random"> - random numbers</A> from the random(4) driver.</P> -<H2><A name="low-end">Low-end systems</A></H2> -<P><EM>Even a 486 can handle a T1 line</EM>, according to this mailing - list message:</P> -<PRE>Subject: Re: linux-ipsec: IPSec Masquerade - Date: Fri, 15 Jan 1999 11:13:22 -0500 - From: Michael Richardson - -. . . A 486/66 has been clocked by Phil Karn to do -10Mb/s encryption.. that uses all the CPU, so half that to get some CPU, -and you have 5Mb/s. 1/3 that for 3DES and you get 1.6Mb/s....</PRE> -<P>and a piece of mail from project technical lead Henry Spencer:</P> -<PRE>Oh yes, and a new timing point for Sandy's docs... A P60 -- yes, a 60MHz -Pentium, talk about antiques -- running a host-to-host tunnel to another -machine shows an FTP throughput (that is, end-to-end results with a real -protocol) of slightly over 5Mbit/s either way. (The other machine is much -faster, the network is 100Mbps, and the ether cards are good ones... so -the P60 is pretty definitely the bottleneck.)</PRE> -<P>From the above, and from general user experience as reported on the - list, it seems clear that a cheap surplus machine -- a reasonable 486, - a minimal Pentium box, a Sparc 5, ... -- can easily handle a home - office or a small company connection using any of:</P> -<UL> -<LI>ADSL service</LI> -<LI>cable modem</LI> -<LI>T1</LI> -<LI>E1</LI> -</UL> -<P>If available, we suggest using a Pentium 133 or better. This should - ensure that, even under maximum load, IPsec will use less than half the - CPU cycles. You then have enough left for other things you may want on - your gateway -- firewalling, web caching, DNS and such.</P> -<H2><A name="klips.bench">Measuring KLIPS</A></H2> -<P>Here is some additional data from the mailing list.</P> -<PRE>Subject: FreeSWAN (specically KLIPS) performance measurements - Date: Thu, 01 Feb 2001 - From: Nigel Metheringham <Nigel.Metheringham@intechnology.co.uk> - -I've spent a happy morning attempting performance tests against KLIPS -(this is due to me not being able to work out the CPU usage of KLIPS so -resorting to the crude measurements of maximum throughput to give a -baseline to work out loading of a box). - -Measurements were done using a set of 4 boxes arranged in a line, each -connected to the next by 100Mbit duplex ethernet. The inner 2 had an -ipsec tunnel between them (shared secret, but I was doing measurements -when the tunnel was up and running - keying should not be an issue -here). The outer pair of boxes were traffic generators or traffic sink. - -The crypt boxes are Compaq DL380s - Uniprocessor PIII/733 with 256K -cache. They have 128M main memory. Nothing significant was running on -the boxes other than freeswan. The kernel was a 2.2.19pre7 patched -with freeswan and ext3. - -Without an ipsec tunnel in the chain (ie the 2 inner boxes just being -100BaseT routers), throughput (measured with ttcp) was between 10644 -and 11320 KB/sec - -With an ipsec tunnel in place, throughput was between 3268 and 3402 -KB/sec - -These measurements are for data pushed across a TCP link, so the -traffic on the wire between the 2 ipsec boxes would have been higher -than this.... - -vmstat (run during some other tests, so not affecting those figures) on -the encrypting box shows approx 50% system & 50% idle CPU - which I -don't believe at all. Interactive feel of the box was significantly -sluggish. - -I also tried running the kernel profiler (see man readprofile) during -test runs. - -A box doing primarily decrypt work showed basically nothing happening - -I assume interrupts were off. -A box doing encrypt work showed the following:- - Ticks Function Load - ~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~ - 956 total 0.0010 - 532 des_encrypt2 0.1330 - 110 MD5Transform 0.0443 - 97 kmalloc 0.1880 - 39 des_encrypt3 0.1336 - 23 speedo_interrupt 0.0298 - 14 skb_copy_expand 0.0250 - 13 ipsec_tunnel_start_xmit 0.0009 - 13 Decode 0.1625 - 11 handle_IRQ_event 0.1019 - 11 .des_ncbc_encrypt_end 0.0229 - 10 speedo_start_xmit 0.0188 - 9 satoa 0.0225 - 8 kfree 0.0118 - 8 ip_fragment 0.0121 - 7 ultoa 0.0365 - 5 speedo_rx 0.0071 - 5 .des_encrypt2_end 5.0000 - 4 _stext 0.0140 - 4 ip_fw_check 0.0035 - 2 rj_match 0.0034 - 2 ipfw_output_check 0.0200 - 2 inet_addr_type 0.0156 - 2 eth_copy_and_sum 0.0139 - 2 dev_get 0.0294 - 2 addrtoa 0.0143 - 1 speedo_tx_buffer_gc 0.0024 - 1 speedo_refill_rx_buf 0.0022 - 1 restore_all 0.0667 - 1 number 0.0020 - 1 net_bh 0.0021 - 1 neigh_connected_output 0.0076 - 1 MD5Final 0.0083 - 1 kmem_cache_free 0.0016 - 1 kmem_cache_alloc 0.0022 - 1 __kfree_skb 0.0060 - 1 ipsec_rcv 0.0001 - 1 ip_rcv 0.0014 - 1 ip_options_fragment 0.0071 - 1 ip_local_deliver 0.0023 - 1 ipfw_forward_check 0.0139 - 1 ip_forward 0.0011 - 1 eth_header 0.0040 - 1 .des_encrypt3_end 0.0833 - 1 des_decrypt3 0.0034 - 1 csum_partial_copy_generic 0.0045 - 1 call_out_firewall 0.0125 - -Hope this data is helpful to someone... however the lack of visibility -into the decrypt side makes things less clear</PRE> -<H2><A name="speed.compress">Speed with compression</A></H2> -<P>Another user reported some results for connections with and without - IP compression:</P> -<PRE>Subject: [Users] Speed with compression - Date: Fri, 29 Jun 2001 - From: John McMonagle <johnm@advocap.org> - -Did a couple tests with compression using the new 1.91 freeswan. - -Running between 2 sites with cable modems. Both using approximately -130 mhz pentium. - -Transferred files with ncftp. - -Compressed file was a 6mb compressed installation file. -Non compressed was 18mb /var/lib/rpm/packages.rpm - - Compressed vpn regular vpn -Compress file 42.59 kBs 42.08 kBs -regular file 110.84 kBs 41.66 kBs - -Load was about 0 either way. -Ping times were very similar a bit above 9 ms. - -Compression looks attractive to me.</PRE> - Later in the same thread, project technical lead Henry Spencer added: -<PRE>> is there a reason not to switch compression on? I have large gateway boxes -> connecting 3 connections, one of them with a measly DS1 link... - -Run some timing tests with and without, with data and loads representative -of what you expect in production. That's the definitive way to decide. -If compression is a net loss, then obviously, leave it turned off. If it -doesn't make much difference, leave it off for simplicity and hence -robustness. If there's a substantial gain, by all means turn it on. - -If both ends support compression and can successfully negotiate a -compressed connection (trivially true if both are FreeS/WAN 1.91), then -the crucial question is CPU cycles. - -Compression has some overhead, so one question is whether *your* data -compresses well enough to save you more CPU cycles (by reducing the volume -of data going through CPU-intensive encryption/decryption) than it costs -you. Last time I ran such tests on data that was reasonably compressible -but not deliberately contrived to be so, this generally was not true -- -compression cost extra CPU cycles -- so compression was worthwhile only if -the link, not the CPU, was the bottleneck. However, that was before the -slow-compression bug was fixed. I haven't had a chance to re-run those -tests yet, but it sounds like I'd probably see a different result. </PRE> - The bug he refers to was a problem with the compression libraries that - had us using C code, rather than assembler, for compression. It was - fixed before 1.91. -<H2><A name="methods">Methods of measuring</A></H2> -<P>If you want to measure the loads FreeS/WAN puts on a system, note - that tools such as top or measurements such as load average are - more-or-less useless for this. They are not designed to measure - something that does most of its work inside the kernel.</P> -<P>Here is a message from FreeS/WAN kernel programmer Richard Guy Briggs - on this:</P> -<PRE>> I have a batch of boxes doing Freeswan stuff. -> I want to measure the CPU loading of the Freeswan tunnels, but am -> having trouble seeing how I get some figures out... -> -> - Keying etc is in userspace so will show up on the per-process -> and load average etc (ie pluto's load) - -Correct. - -> - KLIPS is in the kernel space, and does not show up in load average -> I think also that the KLIPS per-packet processing stuff is running -> as part of an interrupt handler so it does not show up in the -> /proc/stat system_cpu or even idle_cpu figures - -It is not running in interrupt handler. It is in the bottom half. -This is somewhere between user context (careful, this is not -userspace!) and hardware interrupt context. - -> Is this correct, and is there any means of instrumenting how much the -> cpu is being loaded - I don't like the idea of a system running out of -> steam whilst still showing 100% idle CPU :-) - -vmstat seems to do a fairly good job, but use a running tally to get a -good idea. A one-off call to vmstat gives different numbers than a -running stat. To do this, put an interval on your vmstat command -line.</PRE> - and another suggestion from the same thread: -<PRE>Subject: Re: Measuring the CPU usage of Freeswan - Date: Mon, 29 Jan 2001 - From: Patrick Michael Kane <modus@pr.es.to> - -The only truly accurate way to accurately track FreeSWAN CPU usage is to use -a CPU soaker. You run it on an unloaded system as a benchmark, then start up -FreeSWAN and take the difference to determine how much FreeSWAN is eating. -I believe someone has done this in the past, so you may find something in -the FreeSWAN archives. If not, someone recently posted a URL to a CPU -soaker benchmark tool on linux-kernel.</PRE> -<HR> -<H1><A name="test.freeswan">Testing FreeS/WAN</A></H1> - This document discusses testing FreeS/WAN. -<P>Not all types of testing are described here. Other parts of the - documentation describe some tests:</P> -<DL> -<DT><A href="#testinstall">installation</A> document</DT> -<DD>testing for a successful install</DD> -<DT><A href="config.html#testsetup">configuration</A> document</DT> -<DD>basic tests for a working configuration</DD> -<DT><A href="#interop.web">web links</A> document</DT> -<DD>General information on tests for interoperability between various - IPsec implementations. This includes links to several test sites.</DD> -<DT><A href="interop.html">interoperation</A> document.</DT> -<DD>More specific information on FreeS/WAN interoperation with other - implementations.</DD> -<DT><A href="performance.html">performance</A> document</DT> -<DD>performance measurements</DD> -</DL> -<P>The test setups and procedures described here can also be used in - other testing, but this document focuses on testing the IPsec - functionality of FreeS/WAN.</P> -<H2><A NAME="test.oe">Testing opportunistic connections</A></H2> -<P>This section teaches you how to test your opportunistically encrypted - (OE) connections. To set up OE, please see the easy instructions in our<A -HREF="quickstart.html"> quickstart guide</A>.</P> -<H3><A NAME="12_1_1">Basic OE Test</A></H3> -<P>This test is for basic OE functionality. -<!-- You may use it on an -<A HREF="quickstart.html#oppo.client">initiate-only OE</A> box or a -<A HREF="quickstart.html#opp.incoming">full OE</A> box. --> - For additional tests, keep - reading.</P> -<P>Be sure IPsec is running. You can see whether it is with:</P> -<PRE> ipsec setup status</PRE> -<P>If need be, you can restart it with:</P> -<PRE> service ipsec restart</PRE> -<P>Load a FreeS/WAN test website from the host on which you're running - FreeS/WAN. Note: the feds may be watching these sites. Type one of:</P> -<P></P> -<PRE> links oetest.freeswan.org</PRE> -<PRE> links oetest.freeswan.nl</PRE> - -<!--<PRE> links oetest.freeswan.ca</PRE>--> -<P>A positive result looks like this:</P> -<PRE> - You seem to be connecting from: 192.0.2.11 which DNS says is: - gateway.example.com - _________________________________________________________________ - - Status E-route - OE enabled 16 192.139.46.73/32 -> 192.0.2.11/32 => - tun0x2097@192.0.2.11 - OE enabled 176 192.139.46.77/32 -> 192.0.2.11/32 => - tun0x208a@192.0.2.11 -</PRE> -<P>If you see this, congratulations! Your OE box will now encrypt its - own traffic whenever it can. If you have difficulty, see our<A HREF="#oe.trouble"> - OE troubleshooting tips</A>.</P> -<H3><A NAME="12_1_2">OE Gateway Test</A></H3> -<P>If you've set up FreeS/WAN to protect a subnet behind your gateway, - you'll need to run another simple test, which can be done from a - machine running any OS. That's right, your Windows box can be protected - by opportunistic encryption without any FreeS/WAN install or - configuration on that box. From<STRONG> each protected subnet node</STRONG> -, load the FreeS/WAN website with:</P> -<PRE> links oetest.freeswan.org</PRE> -<PRE> links oetest.freeswan.nl</PRE> -<P>A positive result looks like this:</P> -<PRE> - You seem to be connecting from: 192.0.2.98 which DNS says is: - box98.example.com - _________________________________________________________________ - - Status E-route - OE enabled 16 192.139.46.73/32 -> 192.0.2.98/32 => - tun0x134ed@192.0.2.11 - OE enabled 176 192.139.46.77/32 -> 192.0.2.11/32 => - tun0x134d2@192.0.2.11 -</PRE> -<P>If you see this, congratulations! Your OE gateway will now encrypt - traffic for this subnet node whenever it can. If you have difficulty, - see our<A HREF="#oe.trouble"> OE troubleshooting tips</A>.</P> -<H3><A NAME="12_1_3">Additional OE tests</A></H3> -<P>When testing OE, you will often find it useful to execute this - command on the FreeS/WAN host:</P> -<PRE> ipsec eroute</PRE> -<P>If you have established a connection (either for or for a subnet - node) you will see a result like:</P> -<PRE> 192.0.2.11/32 -> 192.139.46.73/32 => tun0x149f@192.139.46.38 -</PRE> -<P>Key:</P> -<TABLE> -<TR><TD>1.</TD><TD>192.0.2.11/32</TD><TD>Local start point of the - protected traffic.</TD></TR> -<TR><TD>2.</TD><TD>192.0.2.194/32</TD><TD>Remote end point of the - protected traffic.</TD></TR> -<TR><TD>3.</TD><TD>192.0.48.38</TD><TD>Remote FreeS/WAN node (gateway or - host). May be the same as (2).</TD></TR> -<TR><TD>4.</TD><TD>[not shown]</TD><TD>Local FreeS/WAN node (gateway or - host), where you've produced the output. May be the same as (1).</TD></TR> -</TABLE> -<P>For extra assurance, you may wish to use a packet sniffer such as<A HREF="http://www.tcpdump.org"> - tcpdump</A> to verify that packets are being encrypted. You should see - output that indicates<STRONG> ESP</STRONG> encrypted data, for example:</P> -<PRE> 02:17:47.353750 PPPoE [ses 0x1e12] IP 154: xy.example.com > oetest.freeswan.org: ESP(spi=0x87150d16,seq=0x55)</PRE> -<H2><A name="test.uml">Testing with User Mode Linux</A></H2> -<P><A href="http://user-mode-linux.sourceforge.net/">User Mode Linux</A> - allows you to run Linux as a user process on another Linux machine.</P> -<P>As of 1.92, the distribution has a new directory named testing. It - contains a collection of test scripts and sample configurations. Using - these, you can bring up several copies of Linux in user mode and have - them build tunnels to each other. This lets you do some testing of a - FreeS/WAN configuration on a single machine.</P> -<P>You need a moderately well-endowed machine for this to work well. - Each UML wants about 16 megs of memory by default, which is plenty for - FreeS/WAN usage. Typical regression testing only occasionally uses as - many as 4 UMLs. If one is doing nothing else with the machine (in - particular, not running X on it), then 128 megs and a 500MHz CPU are - fine.</P> - Documentation on these scripts is<A href="umltesting.html"> here</A>. - There is also documentation on automated testing<A href="makecheck.html"> - here</A>. -<H2><A name="testnet">Configuration for a testbed network</A></H2> -<P>A common test setup is to put a machine with dual Ethernet cards in - between two gateways under test. You need at least five machines; two - gateways, two clients and a testing machine in the middle.</P> -<P>The central machine both routes packets and provides a place to run - diagnostic software for checking IPsec packets. See next section for - discussion of<A href="#tcpdump.faq"> using tcpdump(8)</A> for this.</P> -<P>This makes things more complicated than if you just connected the two - gateway machines directly to each other, but it also makes your test - setup much more like the environment you actually use IPsec in. Those - environments nearly always involve routing, and quite a few apparent - IPsec failures turn out to be problems with routing or with firewalls - dropping packets. This approach lets you deal with those problems on - your test setup.</P> -<P>What you end up with looks like:</P> -<H3><A name="testbed">Testbed network</A></H3> -<PRE> subnet a.b.c.0/24 - | - eth1 = a.b.c.1 - gate1 - eth0 = 192.168.p.1 - | - | - eth0 = 192.168.p.2 - route/monitor box - eth1 = 192.168.q.2 - | - | - eth0 = 192.168.q.1 - gate2 - eth1 = x.y.z.1 - | - subnet x.y.z.0/24</PRE> -<PRE>Where p and q are any convenient values that do not interfere with other -routes you may have. The ipsec.conf(5) file then has, among other things:</PRE> -<PRE>conn abc-xyz - left=192.168.p.1 - leftnexthop=192.168.p.2 - right=192.168.q.1 - rightnexthop=192.168.q.2</PRE> -<P>Once that works, you can remove the "route/monitor box", and connect - the two gateways to the Internet. The only parameters in ipsec.conf(5) - that need to change are the four shown above. You replace them with - values appropriate for your Internet connection, and change the eth0 IP - addresses and the default routes on both gateways.</P> -<P>Note that nothing on either subnet needs to change. This lets you - test most of your IPsec setup before connecting to the insecure - Internet.</P> -<H3><A name="tcpdump.test">Using packet sniffers in testing</A></H3> -<P>A number of tools are available for looking at packets. We will - discuss using<A href="http://www.tcpdump.org/"> tcpdump(8)</A>, a - common Linux tool included in most distributions. Alternatives - offerring more-or-less the same functionality include:</P> -<DL> -<DT><A href="http://www.ethereal.com">Ethereal</A></DT> -<DD>Several people on our mailing list report a preference for this over - tcpdump.</DD> -<DT><A href="http://netgroup-serv.polito.it/windump/">windump</A></DT> -<DD>a Windows version of tcpdump(8), possibly handy if you have Windows - boxes in your network</DD> -<DT><A href="http://reptile.rug.ac.be/~coder/sniffit/sniffit.html"> -Sniffit</A></DT> -<DD>A linux sniffer that we don't know much about. If you use it, please - comment on our mailing list.</DD> -</DL> -<P>See also this<A href="http://www.tlsecurity.net/unix/ids/sniffer/"> - index</A> of packet sniffers.</P> -<P>tcpdump(8) may misbehave if run on the gateways themselves. It is - designed to look into a normal IP stack and may become confused if you - ask it to display data from a stack which has IPsec in play.</P> -<P>At one point, the problem was quite severe. Recent versions of - tcpdump, however, understand IPsec well enough to be usable on a - gateway. You can get the latest version from<A href="http://www.tcpdump.org/"> - tcpdump.org</A>.</P> -<P>Even with a recent tcpdump, some care is required. Here is part of a - post from Henry on the topic:</P> -<PRE>> a) data from sunset to sunrise or the other way is not being -> encrypted (I am using tcpdump (ver. 3.4) -x/ping -p to check -> packages) - -What *interface* is tcpdump being applied to? Use the -i option to -control this. It matters! If tcpdump is looking at the ipsecN -interfaces, e.g. ipsec0, then it is seeing the packets before they are -encrypted or after they are decrypted, so of course they don't look -encrypted. You want to have tcpdump looking at the actual hardware -interfaces, e.g. eth0. - -Actually, the only way to be *sure* what you are sending on the wire is to -have a separate machine eavesdropping on the traffic. Nothing you can do -on the machines actually running IPsec is 100% guaranteed reliable in this -area (although tcpdump is a lot better now than it used to be).</PRE> -<P>The most certain way to examine IPsec packets is to look at them on - the wire. For security, you need to be certain, so we recommend doing - that. To do so, you need a<STRONG> separate sniffer machine located - between the two gateways</STRONG>. This machine can be routing IPsec - packets, but it must not be an IPsec gateway. Network configuration for - such testing is discussed<A href="#testnet"> above</A>.</P> -<P>Here's another mailing list message with advice on using tcpdump(8):</P> -<PRE>Subject: RE: [Users] Encrypted??? - Date: Thu, 29 Nov 2001 - From: "Joe Patterson" <jpatterson@asgardgroup.com> - -tcpdump -nl -i $EXT-IF proto 50 - --nl tells it not to buffer output or resolve names (if you don't do that it -may confuse you by not outputing anything for a while), -i $EXT-IF (replace -with your external interface) tells it what interface to listen on, and -proto 50 is ESP. Use "proto 51" if for some odd reason you're using AH, and -"udp port 500" if you want to see the isakmp key exchange/tunnel setup -packets. - -You can also run `tcpdump -nl -i ipsec0` to see what traffic is on that -virtual interface. Anything you see there *should* be either encrypted or -dropped (unless you've turned on some strange options in your ipsec.conf -file) - -Another very handy thing is ethereal (http://www.ethereal.com/) which runs -on just about anything, has a nice gui interface (or a nice text-based -interface), and does a great job of protocol breakdown. For ESP and AH -it'll basically just tell you that there's a packet of that protocol, and -what the spi is, but for isakmp it'll actually show you a lot of the tunnel -setup information (until it gets to the point in the protocol where isakmp -is encrypted....)</PRE> -<H2><A name="verify.crypt">Verifying encryption</A></H2> -<P>The question of how to verify that messages are actually encrypted - has been extensively discussed on the mailing list. See this<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/07/msg00262.html"> - thread</A>.</P> -<P>If you just want to verify that packets are encrypted, look at them - with a packet sniffer (see<A href="#tcpdump.test"> previous section</A> -) located between the gateways. The packets should, except for some of - the header information, be utterly unintelligible.<STRONG> The output - of good encryption looks<EM> exactly</EM> like random noise</STRONG>.</P> -<P>A packet sniffer can only tell you that the data you looked at was - encrypted. If you have stronger requirements -- for example if your - security policy requires verification that plaintext is not leaked - during startup or under various anomolous conditions -- then you will - need to devise much more thorough tests. If you do that, please post - any results or methodological details which your security policy allows - you to make public.</P> -<P>You can put recognizable data into ping packets with something like:</P> -<PRE> ping -p feedfacedeadbeef 11.0.1.1</PRE> -<P>"feedfacedeadbeef" is a legal hexadecimal pattern that is easy to - pick out of hex dumps.</P> -<P>For other protocols, you may need to check if you have encrypted data - or ASCII text. Encrypted data has approximately equal frequencies for - all 256 possible characters. ASCII text has most characters in the - printable range 0x20-0x7f, a few control characters less than 0x20, and - none at all in the range 0x80-0xff. 0x20, space, is a good character to - look for. In normal English text space occurs about once in seven - characters, versus about once in 256 for random or encrypted data.</P> -<P>One thing to watch for: the output of good compression, like that of - good encryption, looks just like random noise. You cannot tell just by - looking at a data stream whether it has been compressed, encrypted, or - both. You need a little care not to mistake compressed data for - encrypted data in your testing.</P> -<P>Note also that weak encryption also produces random-looking output. - You cannot tell whether the encryption is strong by looking at the - output. To be sure of that, you would need to have both the algorithms - and the implementation examined by experts.</P> -<P>For IPsec, you can get partial assurance from interoperability tests. - See our<A href="interop.html"> interop</A> document. When twenty - products all claim to implement<A href="#3DES"> 3DES</A>, and they all - talk to each other, you can be fairly sure they have it right. Of - course, you might wonder whether all the implementers are consipring to - trick you or, more plausibly, whether some implementations might have - "back doors" so they can get also it wrong when required.. If you're - seriously worried about things like that, you need to get the code you - use audited (good luck if it is not Open Source), or perhaps to talk to - a psychiatrist about treatments for paranoia.</P> -<H2><A name="mail.test">Mailing list pointers</A></H2> -<P>Additional information on testing can be found in these<A href="mail.html"> - mailing list</A> messages:</P> -<UL> -<LI>a user's detailed<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/11/msg00571.html"> - setup diary</A> for his testbed network</LI> -<LI>a FreeS/WAN team member's<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/11/msg00425.html"> - notes</A> from testing at an IPsec interop "bakeoff"</LI> -</UL> -<HR> -<H1><A name="kernelconfig">Kernel configuration for FreeS/WAN</A></H1> -<P> This section lists many of the options available when configuring a - Linux kernel, and explains how they should be set on a FreeS/WAN IPsec - gateway.</P> -<H2><A name="notall">Not everyone needs to worry about kernel - configuration</A></H2> -<P>Note that in many cases you do not need to mess with these.</P> -<P> You may have a Linux distribution which comes with FreeS/WAN - installed (see this<A href="#products"> list</A>). In that case, you - need not do a FreeS/WAN installation or a kernel configuration. Of - course, you might still want to configure and rebuild your kernel to - improve performance or security. This can be done with standard tools - described in the<A href="http://www.linuxdoc.org/HOWTO/Kernel-HOWTO.html"> - Kernel HowTo</A>.</P> -<P>If you need to install FreeS/WAN, then you do need to configure a - kernel. However, you may choose to do that using the simplest - procedure:</P> -<UL> -<LI>Configure, build and test a kernel for your system before adding - FreeS/WAN. See the<A href="http://www.linuxdoc.org/HOWTO/Kernel-HOWTO.html"> - Kernel HowTo</A> for details.<STRONG> This step cannot be skipped</STRONG> -. FreeS/WAN needs the results of your configuration.</LI> -<LI>Then use FreeS/WAN's<VAR> make oldgo</VAR> command. This sets - everything FreeS/WAN needs and retains your values everywhere else.</LI> -</UL> -<P> This document is for those who choose to configure their FreeS/WAN - kernel themselves.</P> -<H2><A name="assume">Assumptions and notation</A></H2> -<P> Help text for most kernel options is included with the kernel files, - and is accessible from within the configuration utilities. We assume - you will refer to that, and to the<A href="http://www.linuxdoc.org/HOWTO/Kernel-HOWTO.html"> - Kernel HowTo</A>, as necessary. This document covers only the - FreeS/WAN-specific aspects of the problem.</P> -<P> To avoid duplication, this document section does not cover settings - for the additional IPsec-related kernel options which become available - after you have patched your kernel with FreeS/WAN patches. There is - help text for those available from within the configuration utility.</P> -<P> We assume a common configuration in which the FreeS/WAN IPsec - gateway is also doing ipchains(8) firewalling for a local network, and - possibly masquerading as well.</P> -<P> Some suggestions below are labelled as appropriate for "a true - paranoid". By this we mean they may cause inconvenience and it is not - entirely clear they are necessary, but they appear to be the safest - choice. Not using them might entail some risk. Of course one suggested - mantra for security administrators is: "I know I'm paranoid. I wonder - if I'm paranoid enough."</P> -<H3><A name="labels">Labels used</A></H3> -<P> Six labels are used to indicate how options should be set. We mark - the labels with [square brackets]. For two of these labels, you have no - choice:</P> -<DL> -<DT>[required]</DT> -<DD>essential for FreeS/WAN operation.</DD> -<DT>[incompatible]</DT> -<DD>incompatible with FreeS/WAN.</DD> -</DL> -<P>those must be set correctly or FreeS/WAN will not work</P> -<P>FreeS/WAN should work with any settings of the others, though of - course not all combinations have been tested. We do label these in - various ways, but<EM> these labels are only suggestions</EM>.</P> -<DL> -<DT>[recommended]</DT> -<DD>useful on most FreeS/WAN gateways</DD> -<DT>[disable]</DT> -<DD>an unwelcome complication on a FreeS/WAN gateway.</DD> -<DT>[optional]</DT> -<DD>Your choice. We outline issues you might consider.</DD> -<DT>[anything]</DT> -<DD>This option has no direct effect on FreeS/WAN and related tools, so - you should be able to set it as you please.</DD> -</DL> -<P> Of course complexity is an enemy in any effort to build secure - systems.<STRONG> For maximum security, any feature that can reasonably - be turned off should be</STRONG>. "If in doubt, leave it out."</P> -<H2><A name="kernelopt">Kernel options for FreeS/WAN</A></H2> -<P> Indentation is based on the nesting shown by 'make menuconfig' with - a 2.2.16 kernel for the i386 architecture.</P> -<DL> -<DT><A name="maturity">Code maturity and level options</A></DT> -<DD> -<DL> -<DT><A name="devel">Prompt for development ... code/drivers</A></DT> -<DD>[optional] If this is<VAR> no</VAR>, experimental drivers are not - shown in later menus. -<P>For most FreeS/WAN work,<VAR> no</VAR> is the preferred setting. - Using new or untested components is too risky for a security gateway.</P> -<P>However, for some hardware (such as the author's network cards) the - only drivers available are marked<VAR> new/experimental</VAR>. In such - cases, you must enable this option or your cards will not appear under - "network device support". A true paranoid would leave this option off - and replace the cards.</P> -</DD> -<DT>Processor type and features</DT> -<DD>[anything]</DD> -<DT>Loadable module support</DT> -<DD> -<DL> -<DT>Enable loadable module support</DT> -<DD>[optional] A true paranoid would disable this. An attacker who has - root access to your machine can fairly easily install a bogus module - that does awful things, provided modules are enabled. A common tool for - attackers is a "rootkit", a set of tools the attacker uses once he or - she has become root on your system. The kit introduces assorted - additional compromises so that the attacker will continue to "own" your - system despite most things you might do to recovery the situation. For - Linux, there is a tool called<A href="http://www.sans.org/newlook/resources/IDFAQ/knark.htm"> - knark</A> which is basically a rootkit packaged as a kernel module. -<P>With modules disabled, an attacker cannot install a bogus module. The - only way he can achieve the same effects is to install a new kernel and - reboot. This is considerably more likely to be noticed.</P> -<P>Many FreeS/WAN gateways run with modules enabled. This simplifies - some administrative tasks and some ipchains features are available only - as modules. Once an enemy has root on your machine your security is - nil, so arguably defenses which come into play only in that situation - are pointless.</P> -<P></P> -</DD> -<DT>Set version information ....</DT> -<DD>[optional] This provides a check to prevent loading modules compiled - for a different kernel.</DD> -<DT>Kernel module loader</DT> -<DD>[disable] It gives little benefit on a typical FreeS/WAN gate and - entails some risk.</DD> -</DL> -</DD> -<DT>General setup</DT> -<DD>We list here only the options that matter for FreeS/WAN. -<DL> -<DT>Networking support</DT> -<DD>[required]</DD> -<DT>Sysctl interface</DT> -<DD>[optional] If this option is turned on and the<VAR> /proc</VAR> - filesystem installed, then you can control various system behaviours by - writing to files under<VAR> /proc/sys</VAR>. For example: -<PRE> echo 1 > /proc/sys/net/ipv4/ipforward</PRE> - turns IP forwarding on. -<P>Disabling this option breaks many firewall scripts. A true paranoid - would disable it anyway since it might conceivably be of use to an - attacker.</P> -</DD> -</DL> -</DD> -<DT>Plug and Play support</DT> -<DD>[anything]</DD> -<DT>Block devices</DT> -<DD>[anything]</DD> -<DT>Networking options</DT> -<DD> -<DL> -<DT>Packet socket</DT> -<DD>[optional] This kernel feature supports tools such as tcpdump(8) - which communicate directly with network hardware, bypassing kernel - protocols. This is very much a two-edged sword: -<UL> -<LI>such tools can be very useful to the firewall admin, especially - during initial testing</LI> -<LI>should an evildoer breach your firewall, such tools could give him - or her a great deal of information about the rest of your network</LI> -</UL> - We recommend disabling this option on production gateways.</DD> -<DT><A name="netlink">Kernel/User netlink socket</A></DT> -<DD>[optional] Required if you want to use<A href="#adv"> advanced - router</A> features.</DD> -<DT>Routing messages</DT> -<DD>[optional]</DD> -<DT>Netlink device emulation</DT> -<DD>[optional]</DD> -<DT>Network firewalls</DT> -<DD>[recommended] You need this if the IPsec gateway also functions as a - firewall. -<P>Even if the IPsec gateway is not your primary firewall, we suggest - setting this so that you can protect the gateway with at least basic - local packet filters.</P> -</DD> -<DT>Socket filtering</DT> -<DD>[disable] This enables an older filtering interface. We suggest - using ipchains(8) instead. To do that, set the "Network firewalls" - option just above, and not this one.</DD> -<DT>Unix domain sockets</DT> -<DD>[required] These sockets are used for communication between the<A href="manpage.d/ipsec.8.html"> - ipsec(8)</A> commands and the<A href="manpage.d/ipsec_pluto.8.html"> - ipsec_pluto(8)</A> daemon.</DD> -<DT>TCP/IP networking</DT> -<DD>[required] -<DL> -<DT>IP: multicasting</DT> -<DD>[anything]</DD> -<DT><A name="adv">IP: advanced router</A></DT> -<DD>[optional] This gives you policy routing, which some people have - used to good advantage in their scripts for FreeS/WAN gateway - management. It is not used in our distributed scripts, so not required - unless you want it for custom scripts. It requires the<A href="#netlink"> - netlink</A> interface between kernel code and the iproute2(8) command.</DD> -<DT>IP: kernel level autoconfiguration</DT> -<DD>[disable] It gives little benefit on a typical FreeS/WAN gate and - entails some risk.</DD> -<DT>IP: firewall packet netlink device</DT> -<DD>[disable]</DD> -<DT>IP: transparent proxy support</DT> -<DD>[optional] This is required in some firewall configurations, but - should be disabled unless you have a definite need for it.</DD> -<DT>IP: masquerading</DT> -<DD>[optional] Required if you want to use<A href="#non-routable"> - non-routable</A> private IP addresses for your local network.</DD> -<DT>IP: Optimize as router not host</DT> -<DD>[recommended]</DD> -<DT>IP: tunneling</DT> -<DD>[required]</DD> -<DT>IP: GRE tunnels over IP</DT> -<DD>[anything]</DD> -<DT>IP: aliasing support</DT> -<DD>[anything]</DD> -<DT>IP: ARP daemon support (EXPERIMENTAL)</DT> -<DD>Not required on most systems, but might prove useful on - heavily-loaded gateways.</DD> -<DT>IP: TCP syncookie support</DT> -<DD>[recommended] It provides a defense against a<A href="#DOS"> denial - of service attack</A> which uses bogus TCP connection requests to waste - resources on the victim machine.</DD> -<DT>IP: Reverse ARP</DT> -<DD></DD> -<DT>IP: large window support</DT> -<DD>[recommended] unless you have less than 16 meg RAM</DD> -</DL> -</DD> -<DT>IPv6</DT> -<DD>[optional] FreeS/WAN does not currently support IPv6, though work on - integrating FreeS/WAN with the Linux IPv6 stack has begun.<A href="#ipv6"> - Details</A>. -<P> It should be possible to use IPv4 FreeS/WAN on a machine which also - does IPv6. This combination is not yet well tested. We would be quite - interested in hearing results from anyone expermenting with it, via the<A -href="mail.html"> mailing list</A>.</P> -<P> We do not recommend using IPv6 on production FreeS/WAN gateways - until more testing has been done.</P> -</DD> -<DT>Novell IPX</DT> -<DD>[disable]</DD> -<DT>Appletalk</DT> -<DD>[disable] Quite a few Linux installations use IP but also have some - other protocol, such as Appletalk or IPX, for communication with local - desktop machines. In theory it should be possible to configure IPsec - for the IP side of things without interfering with the second protocol. -<P>We do not recommend this. Keep the software on your gateway as simple - as possible. If you need a Linux-based Appletalk or IPX server, use a - separate machine.</P> -</DD> -</DL> -</DD> -<DT>Telephony support</DT> -<DD>[anything]</DD> -<DT>SCSI support</DT> -<DD>[anything]</DD> -<DT>I2O device support</DT> -<DD>[anything]</DD> -<DT>Network device support</DT> -<DD>[anything] should work, but there are some points to note. -<P>The development team test almost entirely on 10 or 100 megabit - Ethernet and modems. In principle, any device that can do IP should be - just fine for IPsec, but in the real world any device that has not been - well-tested is somewhat risky. By all means try it, but don't bet your - project on it until you have solid test results.</P> -<P>If you disabled experimental drivers in the<A href="#maturity"> Code - maturity</A> section above, then those drivers will not be shown here. - Check that option before going off to hunt for missing drivers.</P> -<P>If you want Linux to automatically find more than one ethernet - interface at boot time, you need to:</P> -<UL> -<LI>compile the appropriate driver(s) into your kernel. Modules will not - work for this</LI> -<LI>add a line such as -<PRE> - append="ether=0,0,eth0 ether=0,0,eth1" -</PRE> - to your /etc/lilo.conf file. In some cases you may need to specify - parameters such as IRQ or base address. The example uses "0,0" for - these, which tells the system to search. If the search does not succeed - on your hardware, then you should retry with explicit parameters. See - the lilo.conf(5) man page for details.</LI> -<LI>run lilo(8)</LI> -</UL> - Having Linux find the cards this way is not necessary, but is usually - more convenient than loading modules in your boot scripts.</DD> -<DT>Amateur radio support</DT> -<DD>[anything]</DD> -<DT>IrDA (infrared) support</DT> -<DD>[anything]</DD> -<DT>ISDN subsystem</DT> -<DD>[anything]</DD> -<DT>Old CDROM drivers</DT> -<DD>[anything]</DD> -<DT>Character devices</DT> -<DD>The only required character device is: -<DL> -<DT>random(4)</DT> -<DD>[required] This is a source of<A href="#random"> random</A> numbers - which are required for many cryptographic protocols, including several - used in IPsec. -<P>If you are comfortable with C source code, it is likely a good idea - to go in and adjust the<VAR> #define</VAR> lines in<VAR> - /usr/src/linux/drivers/char/random.c</VAR> to ensure that all sources - of randomness are enabled. Relying solely on keyboard and mouse - randomness is dubious procedure for a gateway machine. You could also - increase the randomness pool size from the default 512 bytes (128 - 32-bit words).</P> -</DD> -</DL> -</DD> -<DT>Filesystems</DT> -<DD>[anything] should work, but we suggest limiting a gateway machine to - the standard Linux ext2 filesystem in most cases.</DD> -<DT>Network filesystems</DT> -<DD>[disable] These systems are an unnecessary risk on an IPsec gateway.</DD> -<DT>Console drivers</DT> -<DD>[anything]</DD> -<DT>Sound</DT> -<DD>[anything] should work, but we suggest enabling sound only if you - plan to use audible alarms for firewall problems.</DD> -<DT>Kernel hacking</DT> -<DD>[disable] This might be enabled on test machines, but should not be - on production gateways.</DD> -</DL> -</DD> -</DL> -<HR> -<H1><A name="adv_config">Other configuration possibilities</A></H1> -<P>This document describes various options for FreeS/WAN configuration - which are less used or more complex (often both) than the standard - cases described in our<A href="#config"> config</A> and<A href="#quick_guide"> - quickstart</A> documents.</P> -<H2><A name="thumb">Some rules of thumb about configuration</A></H2> -<H3><A name="cheap.tunnel">Tunnels are cheap</A></H3> -<P>Nearly all of the overhead in IPsec processing is in the encryption - and authentication of packets. Our<A href="performance.html"> - performance</A> document discusses these overheads.</P> -<P>Beside those overheads, the cost of managing additional tunnels is - trivial. Whether your gateway supports one tunnel or ten just does not - matter. A hundred might be a problem; there is a<A href="#biggate"> - section</A> on this in the performance document.</P> -<P>So, in nearly all cases, if using multiple tunnels gives you a - reasonable way to describe what you need to do, you should describe it - that way in your configuration files.</P> -<P>For example, one user recently asked on a mailing list about this - network configuration:</P> -<PRE> netA---gwA---gwB---netB - |----netC - - netA and B are secured netC not. - netA and gwA can not access netC</PRE> -<P>The user had constructed only one tunnel, netA to netB, and wanted to - know how to use ip-route to get netC packets into it. This is entirely - unnecessary. One of the replies was:</P> -<PRE> The simplest way and indeed the right way to - solve this problem is to set up two connections: - - leftsubnet=NetA - left=gwA - right=gwB - rightsubnet=NetB - and - leftsubnet=NetA - left=gwA - right=gwB - rightsubnet=NetC</PRE> -<P>This would still be correct even if we added nets D, E, F, ... to the - above diagram and needed twenty tunnels.</P> -<P>Of course another possibility would be to just use one tunnel, with a - subnet mask that includes both netB and netC (or B, C, D, ...). See - next section.</P> -<P>In general, you can construct as many tunnels as you need. Networks - like netC in this example that do not connect directly to the gateway - are fine, as long as the gateway can route to them.</P> -<P>The number of tunnels can become an issue if it reaches 50 or so. - This is discussed in the<A href="#biggate"> performance</A> document. - Look there for information on supporting hundreds of Road Warriors from - one gateway.</P> -<P>If you find yourself with too many tunnels for some reason like - having eight subnets at one location and nine at another so you end up - with 9*8=72 tunnels, read the next section here.</P> -<H3><A name="subnet.size">Subnet sizes</A></H3> -<P>The subnets used in<VAR> leftsubnet</VAR> and<VAR> rightsubnet</VAR> - can be of any size that fits your needs, and they need not correspond - to physical networks.</P> -<P>You adjust the size by changing the<A href="#subnet"> subnet mask</A> -, the number after the slash in the subnet description. For example</P> -<UL> -<LI>in 192.168.100.0/24 the /24 mask says 24 bits are used to designate - the network. This leave 8 bits to label machines. This subnet has 256 - addresses. .0 and .255 are reserved, so it can have 254 machines.</LI> -<LI>A subnet with a /23 mask would be twice as large, 512 addresses.</LI> -<LI>A subnet with a /25 mask would be half the size, 128 addresses.</LI> -<LI>/0 is the whole Internet</LI> -<LI>/32 is a single machine</LI> -</UL> -<P>As an example of using these in connection descriptions, suppose your - company's head office has four physical networks using the address - ranges:</P> -<DL> -<DT>192.168.100.0/24</DT> -<DD>development</DD> -<DT>192.168.101.0/24</DT> -<DD>production</DD> -<DT>192.168.102.0/24</DT> -<DD>marketing</DD> -<DT>192.168.103.0/24</DT> -<DD>administration</DD> -</DL> -<P>You can use exactly those subnets in your connection descriptions, or - use larger subnets to grant broad access if required:</P> -<DL> -<DT>leftsubnet=192.168.100.0/24</DT> -<DD>remote hosts can access only development</DD> -<DT>leftsubnet=192.168.100.0/23</DT> -<DD>remote hosts can access development or production</DD> -<DT>leftsubnet=192.168.102.0/23</DT> -<DD>remote hosts can access marketing or administration</DD> -<DT>leftsubnet=192.168.100.0/22</DT> -<DD>remote hosts can access any of the four departments</DD> -</DL> -<P>or use smaller subnets to restrict access:</P> -<DL> -<DT>leftsubnet=192.168.103.0/24</DT> -<DD>remote hosts can access any machine in administration</DD> -<DT>leftsubnet=192.168.103.64/28</DT> -<DD>remote hosts can access only certain machines in administration.</DD> -<DT>leftsubnet=192.168.103.42/32</DT> -<DD>remote hosts can access only one particular machine in - administration</DD> -</DL> -<P>To be exact, 192.68.103.64/28 means all addresses whose top 28 bits - match 192.168.103.64. There are 16 of these because there are 16 - possibilities for the remainingg 4 bits. Their addresses are - 192.168.103.64 to 192.168.103.79.</P> -<P>Each connection description can use a different subnet if required.</P> -<P>It is possible to use all the examples above on the same FreeS/WAN - gateway, each in a different connection description, perhaps for - different classes of user or for different remote offices.</P> -<P>It is also possible to have multiple tunnels using different<VAR> - leftsubnet</VAR> descriptions with the same<VAR> right</VAR>. For - example, when the marketing manager is on the road he or she might have - access to:</P> -<DL> -<DT>leftsubnet=192.168.102.0/24</DT> -<DD>all machines in marketing</DD> -<DT>192.168.101.32/29</DT> -<DD>some machines in production</DD> -<DT>leftsubnet=192.168.103.42/32</DT> -<DD>one particular machine in administration</DD> -</DL> -<P>This takes three tunnels, but tunnels are cheap. If the laptop is set - up to build all three tunnels automatically, then he or she can access - all these machines concurrently, perhaps from different windows.</P> -<H3><A name="example.more">Other network layouts</A></H3> -<P>Here is the usual network picture for a site-to-site VPN::</P> -<PRE> Sunset==========West------------------East=========Sunrise - local net untrusted net local net</PRE> -<P>and for the Road Warrior::</P> -<PRE> telecommuter's PC or - traveller's laptop - Sunset==========West------------------East - corporate LAN untrusted net</PRE> -<P>Other configurations are also possible.</P> -<H4><A name="internet.subnet">The Internet as a big subnet</A></H4> -<P>A telecommuter might have:</P> -<PRE> Sunset==========West------------------East ================= firewall --- the Internet - home network untrusted net corporate network</PRE> -<P>This can be described as a special case of the general - subnet-to-subnet connection. The subnet on the right is 0.0.0.0/0, the - whole Internet.</P> -<P>West (the home gateway) can have its firewall rules set up so that - only IPsec packets to East are allowed out. It will then behave as if - its only connection to the world was a wire to East.</P> -<P>When machines on the home network need to reach the Internet, they do - so via the tunnel, East and the corporate firewall. From the viewpoint - of the Internet (perhaps of some EvilDoer trying to break in!), those - home office machines are behind the firewall and protected by it.</P> -<H4><A name="wireless.config">Wireless</A></H4> -<P>Another possible configuration comes up when you do not trust the - local network, either because you have very high security standards or - because your are using easily-intercepted wireless signals.</P> -<P>Some wireless networks have built-in encryption called<A href="#WEP"> - WEP</A>, but its security is dubious. It is a fairly common practice to - use IPsec instead.</P> -<P>In this case, part of your network may look like this:</P> -<PRE> West-----------------------------East == the rest of your network - workstation untrusted wireless net</PRE> -<P>Of course, there would likely be several wireless workstations, each - with its own IPsec tunnel to the East gateway.</P> -<P>The connection descriptions look much like Road Warrior descriptions:</P> -<UL> -<LI>each workstation should have its own unique -<UL> -<LI>identifier for IPsec</LI> -<LI>RSA key</LI> -<LI>connection description.</LI> -</UL> -</LI> -<LI>on the gateway, use<VAR> left=%any</VAR>, or the workstation IP - address</LI> -<LI>on workstations,<VAR> left=%defaultroute</VAR>, or the workstation - IP address</LI> -<LI><VAR>leftsubnet=</VAR> is not used.</LI> -</UL> -<P>The<VAR> rightsubnet=</VAR> parameter might be set in any of several - ways:</P> -<DL> -<DT>rightsubnet=0.0.0.0/0</DT> -<DD>allowing workstations to access the entire Internet (see<A href="#internet.subnet"> - above</A>)</DD> -<DT>rightsubnet=a.b.c.0/24</DT> -<DD>allowing access to your entire local network</DD> -<DT>rightsubnet=a.b.c.d/32</DT> -<DD>restricting the workstation to connecting to a particular server</DD> -</DL> -<P>Of course you can mix and match these as required. For example, a - university might allow faculty full Internet access while letting - student laptops connect only to a group of lab machines.</P> -<H2><A name="choose">Choosing connection types</A></H2> -<P>One choice you need to make before configuring additional connections - is what type or types of connections you will use. There are several - options, and you can use more than one concurrently.</P> -<H3><A name="man-auto">Manual vs. automatic keying</A></H3> -<P>IPsec allows two types of connections, with manual or automatic - keying. FreeS/WAN starts them with commands such as:</P> -<PRE> ipsec manual --up <VAR>name</VAR> - ipsec auto --up <VAR>name</VAR></PRE> -<P>The difference is in how they are keyed.</P> -<DL> -<DT><A href="#manual">Manually keyed</A> connections</DT> -<DD>use keys stored in<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf</A> -.</DD> -<DT><A href="#auto">Automatically keyed</A> connections</DT> -<DD>use keys automatically generated by the Pluto key negotiation - daemon. The key negotiation protocol,<A href="#IKE"> IKE</A>, must - authenticate the other system. (It is vulnerable to a<A href="#middle"> - man-in-the-middle attack</A> if used without authentication.) We - currently support two authentication methods: -<UL> -<LI>using shared secrets stored in<A href="manpage.d/ipsec.secrets.5.html"> - ipsec.secrets</A>.</LI> -<LI>RSA<A href="#public"> public key</A> authentication, with our - machine's private key in<A href="manpage.d/ipsec.secrets.5.html"> - ipsec.secrets</A>. Public keys for other machines may either be placed - in<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf</A> or provided via - DNS.</LI> -</UL> -<P>A third method, using RSA keys embedded in<A href="#X509"> X.509</A> - certtificates, is provided by user<A href="#patch"> patches</A>.</P> -</DD> -</DL> -<P><A href="#manual">Manually keyed</A> connections provide weaker - security than<A href="#auto"> automatically keyed</A> connections. An - opponent who reads ipsec.secrets(5) gets your encryption key and can - read all data encrypted by it. If he or she has an archive of old - messages, all of them back to your last key change are also readable.</P> -<P>With automatically-(re)-keyed connections, an opponent who reads - ipsec.secrets(5) gets the key used to authenticate your system in IKE - -- the shared secret or your private key, depending what authentication - mechanism is in use. However, he or she does not automatically gain - access to any encryption keys or any data.</P> -<P>An attacker who has your authentication key can mount a<A href="#middle"> - man-in-the-middle attack</A> and, if that succeeds, he or she will get - encryption keys and data. This is a serious danger, but it is better - than having the attacker read everyting as soon as he or she breaks - into ipsec.secrets(5).. Moreover, the keys change often so an opponent - who gets one key does not get a large amount of data. To read all your - data, he or she would have to do a man-in-the-middle attack at every - key change.</P> -<P>We discuss using<A href="#prodman"> manual keying in production</A> - below, but this is<STRONG> not recommended</STRONG> except in special - circumstances, such as needing to communicate with some implementation - that offers no auto-keyed mode compatible with FreeS/WAN.</P> -<P>Manual keying may also be useful for testing. There is some - discussion of this in our<A href="#man4debug"> FAQ</A>.</P> -<H3><A name="auto-auth">Authentication methods for auto-keying</A></H3> -<P>The IKE protocol which Pluto uses to negotiate connections between - gateways must use some form of authentication of peers. A gateway must - know who it is talking to before it can create a secure connection. We - support two basic methods for this authentication:</P> -<UL> -<LI>shared secrets, stored in<A href="manpage.d/ipsec.secrets.5.html"> - ipsec.secrets(5)</A></LI> -<LI>RSA authentication</LI> -</UL> -<P>There are, howver, several variations on the RSA theme, using - different methods of managing the RSA keys:</P> -<UL> -<LI>our RSA private key in<A href="manpage.d/ipsec.secrets.5.html"> - ipsec.secrets(5)</A> with other gateways' public keys -<DL> -<DT>either</DT> -<DD>stored in<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5)</A></DD> -<DT>or</DT> -<DD>looked up via<A href="#DNS"> DNS</A></DD> -</DL> -</LI> -<LI>authentication with<A href="#X509"> x.509</A> certificates.; See our<A -href="#patch"> links section</A> for information on user-contributed - patches for this.:</LI> -</UL> -<P>Public keys in<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5</A> -) give a reasonably straightforward method of specifying keys for - explicitly configured connections.</P> -<P>Putting public keys in DNS allows us to support<A href="#carpediem"> - opportunistic encryption</A>. Any two FreeS/WAN gateways can provide - secure communication, without either of them having any preset - information about the other.</P> -<P>X.509 certificates may be required to interface to various<A href="#PKI"> - PKI</A>s.</P> -<H3><A name="adv-pk">Advantages of public key methods</A></H3> -<P>Authentication with a<A href="#public"> public key</A> method such as<A -href="#RSA"> RSA</A> has some important advantages over using shared - secrets.</P> -<UL> -<LI>no problem of secure transmission of secrets -<UL> -<LI>A shared secret must be shared, so you have the problem of - transmitting it securely to the other party. If you get this wrong, you - have no security.</LI> -<LI>With a public key technique, you transmit only your public key. The - system is designed to ensure that it does not matter if an enemy - obtains public keys. The private key never leaves your machine.</LI> -</UL> -</LI> -<LI>easier management -<UL> -<LI>Suppose you have 20 branch offices all connecting to one gateway at - head office, and all using shared secrets. Then the head office admin - has 20 secrets to manage. Each of them must be kept secret not only - from outsiders, but also from 19 of the branch office admins. The - branch office admins have only one secret each to manage. -<P>If the branch offices need to talk to each other, this becomes - problematic. You need another 20*19/2 = 190 secrets for - branch-to-branch communication, each known to exactly two branches. Now - all the branch admins have the headache of handling 20 keys, each - shared with exactly one other branch or with head office.</P> -<P>For larger numbers of branches, the number of connections and secrets - increases quadratically and managing them becomes a nightmare. A - 1000-gateway fully connected network needs 499,500 secrets, each known - to exactly two players. There are ways to reduce this problem, for - example by introducing a central key server, but these involve - additional communication overheads, more administrative work, and new - threats that must be carefully guarded against.</P> -</LI> -<LI>With public key techniques, the<EM> only</EM> thing you have to keep - secret is your private key, and<EM> you keep that secret from everyone</EM> -. -<P>As network size increaes, the number of public keys used increases - linearly with the number of nodes. This still requires careful - administration in large applications, but is nothing like the disaster - of a quadratic increase. On a 1000-gateway network, you have 1000 - private keys, each of which must be kept secure on one machine, and - 1000 public keys which must be distributed. This is not a trivial - problem, but it is manageable.</P> -</LI> -</UL> -</LI> -<LI>does not require fixed IP addresses -<UL> -<LI>When shared secrets are used in IPsec, the responder must be able to - tell which secret to use by looking at the IP address on the incoming - packets. When the other parties do not have a fixed IP address to be - identified by (for example, on nearly all dialup ISP connections and - many cable or ADSL links), this does not work well -- all must share - the same secret!</LI> -<LI>When RSA authentication is in use, the initiator can identify itself - by name before the key must be determined. The responder then checks - that the message is signed with the public key corresponding to that - name.</LI> -</UL> -</LI> -</UL> -<P>There is also a disadvantage:</P> -<UL> -<LI>your private key is a single point of attack, extremely valuable to - an enemy -<UL> -<LI>with shared secrets, an attacker who steals your ipsec.secrets file - can impersonate you or try<A href="#middle"> man-in-the-middle</A> - attacks, but can only attack connections described in that file</LI> -<LI>an attacker who steals your private key gains the chance to attack - not only existing connections<EM> but also any future connections</EM> - created using that key</LI> -</UL> -</LI> -</UL> -<P>This is partly counterbalanced by the fact that the key is never - transmitted and remains under your control at all times. It is likely - necessary, however, to take account of this in setting security policy. - For example, you should change gateway keys when an administrator - leaves the company, and should change them periodically in any case.</P> -<P>Overall, public key methods are<STRONG> more secure, more easily - managed and more flexible</STRONG>. We recommend that they be used for - all connections, unless there is a compelling reason to do otherwise.</P> -<H2><A name="prodsecrets">Using shared secrets in production</A></H2> -<P>Generally, public key methods are preferred for reasons given above, - but shared secrets can be used with no loss of security, just more work - and perhaps more need to take precautions.</P> -<P>What I call "shared secrets" are sometimes also called "pre-shared - keys". They are used only for for authentication, never for encryption. - Calling them "pre-shared keys" has confused some users into thinking - they were encryption keys, so I prefer to avoid the term..</P> -<P>If you are interoperating with another IPsec implementation, you may - find its documentation calling them "passphrases".</P> -<H3><A name="secrets">Putting secrets in ipsec.secrets(5)</A></H3> -<P>If shared secrets are to be used to<A href="#authentication"> - authenticate</A> communication for the<A href="#DH"> Diffie-Hellman</A> - key exchange in the<A href="#IKE"> IKE</A> protocol, then those secrets - must be stored in<VAR> /etc/ipsec.secrets</VAR>. For details, see the<A href="manpage.d/ipsec.secrets.5.html"> - ipsec.secrets(5)</A> man page.</P> -<P>A few considerations are vital:</P> -<UL> -<LI>make the secrets long and unguessable. Since they need not be - remembered by humans, very long ugly strings may be used. We suggest - using our<A href="manpage.d/ipsec_ranbits.8.html"> ipsec_ranbits(8)</A> - utility to generate long (128 bits or more) random strings.</LI> -<LI>transmit secrets securely. You have to share them with other - systems, but you lose if they are intercepted and used against you. Use<A -href="#PGP"> PGP</A>,<A href="#ssh"> SSH</A>, hand delivery of a floppy - disk which is then destroyed, or some other trustworthy method to - deliver them.</LI> -<LI>store secrets securely, in root-owned files with permissions - rw------.</LI> -<LI>limit sharing of secrets. Alice, Bob, Carol and Dave may all talk to - each other, but only Alice and Bob should know the secret for an - Alice-Bob link.</LI> -<LI><STRONG>do not share private keys</STRONG>. The private key for RSA - authentication of your system is stored in<A href="manpage.d/ipsec.secrets.5.html"> - ipsec.secrets(5)</A>, but it is a different class of secret from the - pre-shared keys used for the "shared secret" authentication. No-one but - you should have the RSA private key.</LI> -</UL> -<P>Each line has the IP addresses of the two gateways plus the secret. - It should look something like this:</P> -<PRE> 10.0.0.1 11.0.0.1 : PSK "jxTR1lnmSjuj33n4W51uW3kTR55luUmSmnlRUuWnkjRj3UuTV4T3USSu23Uk55nWu5TkTUnjT"</PRE> -<P><VAR>PSK</VAR> indicates the use of a<STRONG> p</STRONG>re-<STRONG>s</STRONG> -hared<STRONG> k</STRONG>ey. The quotes and the whitespace shown are - required.</P> -<P>You can use any character string as your secret. For security, it - should be both long and extremely hard to guess. We provide a utility - to generate such strings,<A href="manpage.d/ipsec_ranbits.8.html"> - ipsec_ranbits(8)</A>.</P> -<P>You want the same secret on the two gateways used, so you create a - line with that secret and the two gateway IP addresses. The - installation process supplies an example secret, useful<EM> only</EM> - for testing. You must change it for production use.</P> -<H3><A name="securing.secrets">File security</A></H3> -<P>You must deliver this file, or the relevant part of it, to the other - gateway machine by some<STRONG> secure</STRONG> means.<EM> Don't just - FTP or mail the file!</EM> It is vital that the secrets in it remain - secret. An attacker who knew those could easily have<EM> all the data - on your "secure" connection</EM>.</P> -<P>This file must be owned by root and should have permissions<VAR> - rw-------</VAR>.</P> -<H3><A name="notroadshared">Shared secrets for road warriors</A></H3> -<P>You can use a shared secret to support a single road warrior - connecting to your gateway, and this is a reasonable thing to do in - some circumstances. Public key methods have advantages, discussed<A href="#choose"> - above</A>, but they are not critical in this case.</P> -<P>To do this, the line in ipsec.secrets(5) is something like:</P> -<PRE> 10.0.0.1 0.0.0.0 : PSK "jxTR1lnmSjuj33n4W51uW3kTR55luUmSmnlRUuWnkjRj3UuTV4T3USSu23Uk55nWu5TkTUnjT"</PRE> - where the<VAR> 0.0.0.0</VAR> means that any IP address is acceptable. -<P><STRONG>For more than one road warrior, shared secrets are<EM> not</EM> - recommended.</STRONG> If shared secrets are used, then when the - responder needs to look up the secret, all it knows about the sender is - an IP address. This is fine if the sender is at a fixed IP address - specified in the config file. It is also fine if only one road warrior - uses the wildcard<VAR> 0.0.0.0</VAR> address. However, if you have more - than one road warrior using shared secret authentication, then they - must all use that wildcard and therefore<STRONG> all road warriors - using PSK autentication must use the same secret</STRONG>. Obviously, - this is insecure.</P> -<P><STRONG>For multiple road warriors, use public key authentication.</STRONG> - Each roadwarrior can then have its own identity (our<VAR> leftid=</VAR> - or<VAR> rightid=</VAR> parameters), its own public/private key pair, - and its own secure connection.</P> -<H2><A name="prodman">Using manual keying in production</A></H2> -<P>Generally,<A href="#auto"> automatic keying</A> is preferred over<A href="#manual"> - manual keying</A> for production use because it is both easier to - manage and more secure. Automatic keying frees the admin from much of - the burden of managing keys securely, and can provide<A href="#PFS"> - perfect forward secrecy</A>. This is discussed in more detail<A href="#man-auto"> - above</A>.</P> -<P>However, it is possible to use manual keying in production if that is - what you want to do. This might be necessary, for example, in order to - interoperate with some device that either does not provide automatic - keying or provides it in some version we cannot talk to.</P> -<P>Note that with manual keying<STRONG> all security rests with the keys</STRONG> -. If an adversary acquires your keys, you've had it. He or she can read - everything ever sent with those keys, including old messages he or she - may have archived.</P> -<P>You need to<STRONG> be really paranoid about keys</STRONG> if you're - going to rely on manual keying for anything important.</P> -<UL> -<LI>keep keys in files with 600 permissions, owned by root</LI> -<LI>be extremely careful about security of your gateway systems. Anyone - who breaks into a gateway and gains root privileges can get all your - keys and read everything ever encrypted with those keys, both old - messages he has archived and any new ones you may send.</LI> -<LI>change keys regularly. This can be a considerable bother, (and - provides an excellent reason to consider automatic keying instead), but - it is<EM> absolutely essential</EM> for security. Consider a manually - keyed system in which you leave the same key in place for months: -<UL> -<LI>an attacker can have a very large sample of text sent with that key - to work with. This makes various cryptographic attacks much more likely - to succeed.</LI> -<LI>The chances of the key being compromised in some non-cryptographic - manner -- a spy finds it on a discarded notepad, someone breaks into - your server or your building and steals it, a staff member is bribed, - tricked, seduced or coerced into revealing it, etc. -- also increase - over time.</LI> -<LI>a successful attacker can read everything ever sent with that key. - This makes any successful attack extremely damaging.</LI> -</UL> - It is clear that you must change keys often to have any useful - security. The only question is how often.</LI> -<LI>use<A href="#PGP"> PGP</A> or<A href="#ssh"> SSH</A> for all key - transfers</LI> -<LI>don't edit files with keys in them when someone can look over your - shoulder</LI> -<LI>worry about network security; could someone get keys by snooping - packets on the LAN between your X desktop and the gateway?</LI> -<LI>lock up your backup tapes for the gateway system</LI> -<LI>... and so on</LI> -</UL> -<P>Linux FreeS/WAN provides some facilities to help with this. In - particular, it is good policy to<STRONG> keep keys in separate files</STRONG> - so you can edit configuration information in /etc/ipsec.conf without - exposing keys to "shoulder surfers" or network snoops. We support this - with the<VAR> also=</VAR> and<VAR> include</VAR> syntax in<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A>.</P> -<P>See the last example in our<A href="examples"> examples</A> file. In - the /etc/ipsec.conf<VAR> conn samplesep</VAR> section, it has the line:</P> -<PRE> also=samplesep-keys</PRE> -<P>which tells the "ipsec manual" script to insert the configuration - description labelled "samplesep-keys" if it can find it. The - /etc/ipsec.conf file must also have a line such as:</P> -<PRE>include ipsec.*.conf</PRE> -<P>which tells it to read other files. One of those other files then - might contain the additional data:</P> -<PRE>conn samplesep-keys - spi=0x200 - esp=3des-md5-96 - espenckey=0x01234567_89abcdef_02468ace_13579bdf_12345678_9abcdef0 - espauthkey=0x12345678_9abcdef0_2468ace0_13579bdf</PRE> -<P>The first line matches the label in the "also=" line, so the indented - lines are inserted. The net effect is exactly as if the inserted lines - had occurred in the original file in place of the "also=" line.</P> -<P>Variables set here are:</P> -<DL> -<DT>spi</DT> -<DD>A number needed by the manual keying code. Any 3-digit hex number - will do, but if you have more than one manual connection then<STRONG> - spi must be different</STRONG> for each connection.</DD> -<DT>esp</DT> -<DD>Options for<A href="#ESP"> ESP</A> (Encapsulated Security Payload), - the usual IPsec encryption mode. Settings here are for<A href="#encryption"> - encryption</A> using<A href="#3DES"> triple DES</A> and<A href="#authentication"> - authentication</A> using<A href="#MD5"> MD5</A>. Note that encryption - without authentication should not be used; it is insecure.</DD> -<DT>espenkey</DT> -<DD>Key for ESP encryption. Here, a 192-bit hex number for triple DES.</DD> -<DT>espauthkey</DT> -<DD>Key for ESP authentication. Here, a 128-bit hex number for MD5.</DD> -</DL> -<P><STRONG>Note</STRONG> that the<STRONG> example keys we supply</STRONG> - are intended<STRONG> only for testing</STRONG>. For real use, you - should go to automatic keying. If that is not possible, create your own - keys for manual mode and keep them secret</P> -<P>Of course, any files containing keys<STRONG> must</STRONG> have 600 - permissions and be owned by root.</P> -<P>If you connect in this way to multiple sites, we recommend that you - keep keys for each site in a separate file and adopt some naming - convention that lets you pick them all up with a single "include" line. - This minimizes the risk of losing several keys to one error or attack - and of accidentally giving another site admin keys which he or she has - no business knowing.</P> -<P>Also note that if you have multiple manually keyed connections on a - single machine, then the<VAR> spi</VAR> parameter must be different for - each one. Any 3-digit hex number is OK, provided they are different for - each connection. We reserve the range 0x100 to 0xfff for manual - connections. Pluto assigns SPIs from 0x1000 up for automatically keyed - connections.</P> -<P>If<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5)</A> contains - keys for manual mode connections, then it too must have permissions<VAR> - rw-------</VAR>. We recommend instead that, if you must manual keying - in production, you keep the keys in separate files.</P> -<P>Note also that<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf</A> - is installed with permissions<VAR> rw-r--r--</VAR>. If you plan to use - manually keyed connections for anything more than initial testing, you<B> - must</B>:</P> -<UL> -<LI>either change permissions to<VAR> rw-------</VAR></LI> -<LI>or store keys separately in secure files and access them via include - statements in<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf</A>.</LI> -</UL> -<P>We recommend the latter method for all but the simplest - configurations.</P> -<H3><A name="ranbits">Creating keys with ranbits</A></H3> -<P>You can create new<A href="#random"> random</A> keys with the<A href="manpage.d/ipsec_ranbits.8.html"> - ranbits(8)</A> utility. For example, the commands:</P> -<PRE> umask 177 - ipsec ranbits 192 > temp - ipsec ranbits 128 >> temp</PRE> -<P>create keys in the sizes needed for our default algorithms:</P> -<UL> -<LI>192-bit key for<A href="#3DES"> 3DES</A> encryption -<BR> (only 168 bits are used; parity bits are ignored)</LI> -<LI>128-bit key for keyed<A href="#MD5"> MD5</A> authentication</LI> -</UL> -<P>If you want to use<A href="#SHA"> SHA</A> instead of<A href="#MD5"> - MD5</A>, that requires a 160-bit key</P> -<P>Note that any<STRONG> temporary files</STRONG> used must be kept<STRONG> - secure</STRONG> since they contain keys. That is the reason for the - umask command above. The temporary file should be deleted as soon as - you are done with it. You may also want to change the umask back to its - default value after you are finished working on keys.</P> -<P>The ranbits utility may pause for a few seconds if not enough entropy - is available immediately. See ipsec_ranbits(8) and random(4) for - details. You may wish to provide some activity to feed entropy into the - system. For example, you might move the mouse around, type random - characters, or do<VAR> du /usr > /dev/null</VAR> in the background.</P> -<H2><A name="boot">Setting up connections at boot time</A></H2> -<P>You can tell the system to set up connections automatically at boot - time by putting suitable stuff in /etc/ipsec.conf on both systems. The - relevant section of the file is labelled by a line reading<VAR> config - setup</VAR>.</P> -<P>Details can be found in the<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A> man page. We also provide a file of<A href="examples"> - example configurations</A>.</P> -<P>The most likely options are something like:</P> -<DL> -<DT>interfaces="ipsec0=eth0 ipsec1=ppp0"</DT> -<DD>Tells KLIPS which interfaces to use. Up to four interfaces numbered - ipsec[0-3] are supported. Each interface can support an arbitrary - number of tunnels. -<P>Note that for PPP, you give the ppp[0-9] device name here, not the - underlying device such as modem (or eth1 if you are using PPPoE).</P> -</DD> -<DT>interfaces=%defaultroute</DT> -<DD>Alternative setting, useful in simple cases. KLIPS will pick up both - its interface and the next hop information from the settings of the - Linux default route.</DD> -<DT>forwardcontrol=no</DT> -<DD>Normally "no". Set to "yes" if the IP forwarding option is disabled - in your network configuration. (This can be set as a kernel - configuration option or later. e.g. on Redhat, it's in - /etc/sysconfig/network and on SuSE you can adjust it with Yast.) Linux - FreeS/WAN will then enable forwarding when starting up and turn it off - when going down. This is used to ensure that no packets will be - forwarded before IPsec comes up and takes control.</DD> -<DT>syslog=daemon.error</DT> -<DD>Used in messages to the system logging daemon (syslogd) to specify - what type of software is sending the messages. If the settings are - "daemon.error" as in our example, then syslogd treats the messages as - error messages from a daemon. -<P>Note that<A href="#Pluto"> Pluto</A> does not currently pay attention - to this variable. The variable controls setup messages only.</P> -</DD> -<DT>klipsdebug=</DT> -<DD>Debug settings for<A href="#KLIPS"> KLIPS</A>.</DD> -<DT>plutodebug=</DT> -<DD>Debug settings for<A href="#Pluto"> Pluto</A>.</DD> -<DT>... for both the above DEBUG settings</DT> -<DD>Normally, leave empty as shown above for no debugging output. -<BR> Use "all" for maximum information. -<BR> See ipsec_klipsdebug(8) and ipsec_pluto(8) man page for other - options. Beware that if you set /etc/ipsec.conf to enable debug output, - your system's log files may get large quickly.</DD> -<DT>dumpdir=/safe/directory</DT> -<DD>Normally, programs started by ipsec setup don't crash. If they do, - by default, no core dump will be produced because such dumps would - contain secrets. If you find you need to debug such crashes, you can - set dumpdir to the name of a directory in which to collect the core - file.</DD> -<DT>manualstart=</DT> -<DD>List of manually keyed connections to be automatically started at - boot time. Useful for testing, but not for long term use. Connections - which are automatically started should also be automatically re-keyed.</DD> -<DT>pluto=yes</DT> -<DD>Whether to start<A href="#Pluto"> Pluto</A> when ipsec startup is - done. -<BR> This parameter is optional and defaults to "yes" if not present. -<P>"yes" is strongly recommended for production use so that the keying - daemon (Pluto) will automatically re-key the connections regularly. The - ipsec-auto parameters ikelifetime, ipseclifetime and reykeywindow give - you control over frequency of rekeying.</P> -</DD> -<DT>plutoload="reno-van reno-adam reno-nyc"</DT> -<DD>List of tunnels (by name, e.g. fred-susan or reno-van in our - examples) to be loaded into Pluto's internal database at startup. In - this example, Pluto loads three tunnels into its database when it is - started. -<P>If plutoload is "%search", Pluto will load any connections whose - description includes "auto=add" or "auto=start".</P> -</DD> -<DT>plutostart="reno-van reno-adam reno-nyc"</DT> -<DD>List of tunnels to attempt to negotiate when Pluto is started. -<P>If plutostart is "%search", Pluto will start any connections whose - description includes "auto=start".</P> -<P>Note that, for a connection intended to be permanent,<STRONG> both - gateways should be set try to start</STRONG> the tunnel. This allows - quick recovery if either gateway is rebooted or has its IPsec - restarted. If only one gateway is set to start the tunnel and the other - gateway restarts, the tunnel may not be rebuilt.</P> -</DD> -<DT>plutowait=no</DT> -<DD>Controls whether Pluto waits for one tunnel to be established before - starting to negotiate the next. You might set this to "yes" -<UL> -<LI>if your gateway is a very limited machine and you need to conserve - resources.</LI> -<LI>for debugging; the logs are clearer if only one connection is - brought up at a time</LI> -</UL> - For a busy and resource-laden production gateway, you likely want "no" - so that connections are brought up in parallel and the whole process - takes less time.</DD> -</DL> -<P>The example assumes you are at the Reno office and will use IPsec to - Vancouver, New York City and Amsterdam.</P> -<H2><A name="multitunnel">Multiple tunnels between the same two gateways</A> -</H2> -<P>Consider a pair of subnets, each with a security gateway, connected - via the Internet:</P> -<PRE> 192.168.100.0/24 left subnet - | - 192.168.100.1 - North Gateway - 101.101.101.101 left - | - 101.101.101.1 left next hop - [Internet] - 202.202.202.1 right next hop - | - 202.202.202.202 right - South gateway - 192.168.200.1 - | - 192.168.200.0/24 right subnet</PRE> -<P>A tunnel specification such as:</P> -<PRE>conn northnet-southnet - left=101.101.101.101 - leftnexthop=101.101.101.1 - leftsubnet=192.168.100.0/24 - leftfirewall=yes - right=202.202.202.202 - rightnexthop=202.202.202.1 - rightsubnet=192.168.200.0/24 - rightfirewall=yes</PRE> - will allow machines on the two subnets to talk to each other. You might - test this by pinging from polarbear (192.168.100.7) to penguin - (192.168.200.5). -<P>However,<STRONG> this does not cover other traffic you might want to - secure</STRONG>. To handle all the possibilities, you might also want - these connection descriptions:</P> -<PRE>conn northgate-southnet - left=101.101.101.101 - leftnexthop=101.101.101.1 - right=202.202.202.202 - rightnexthop=202.202.202.1 - rightsubnet=192.168.200.0/24 - rightfirewall=yes - -conn northnet-southgate - left=101.101.101.101 - leftnexthop=101.101.101.1 - leftsubnet=192.168.100.0/24 - leftfirewall=yes - right=202.202.202.202 - rightnexthop=202.202.202.1</PRE> -<P>Without these, neither gateway can do IPsec to the remote subnet. - There is no IPsec tunnel or eroute set up for the traffic.</P> -<P>In our example, with the non-routable 192.168.* addresses used, - packets would simply be discarded. In a different configuration, with - routable addresses for the remote subnet,<STRONG> they would be sent - unencrypted</STRONG> since there would be no IPsec eroute and there - would be a normal IP route.</P> -<P>You might also want:</P> -<PRE>conn northgate-southgate - left=101.101.101.101 - leftnexthop=101.101.101.1 - right=202.202.202.202 - rightnexthop=202.202.202.1</PRE> -<P>This is required if you want the two gateways to speak IPsec to each - other.</P> -<P>This requires a lot of duplication of details. Judicious use of<VAR> - also=</VAR> and<VAR> include</VAR> can reduce this problem.</P> -<P>Note that, while FreeS/WAN supports all four tunnel types, not all - implementations do. In particular, some versions of Windows 2000 and - the freely downloadable version of PGP provide only "client" - functionality. You cannot use them as gateways with a subnet behind - them. To get that functionality, you must upgrade to Windows 2000 - server or the commercially available PGP products.</P> -<H3><A name="advroute">One tunnel plus advanced routing</A></H3> - It is also possible to use the new routing features in 2.2 and later - kernels to avoid most needs for multple tunnels. Here is one mailing - list message on the topic: -<PRE>Subject: Re: linux-ipsec: IPSec packets not entering tunnel? - Date: Mon, 20 Nov 2000 - From: Justin Guyett <jfg@sonicity.com> - -On Mon, 20 Nov 2000, Claudia Schmeing wrote: - -> Right Left -> "home" "office" -> 10.92.10.0/24 ---- 24.93.85.110 ========= 216.175.164.91 ---- 10.91.10.24/24 -> -> I've created all four tunnels, and can ping to test each of them, -> *except* homegate-officenet. - -I keep wondering why people create all four tunnels. Why not route -traffic generated from home to 10.91.10.24/24 out ipsec0 with iproute2? -And 99% of the time you don't need to access "office" directly, which -means you can eliminate all but the subnet<->subnet connection.</PRE> - and FreeS/WAN technical lead Henry Spencer's comment: -<PRE>> I keep wondering why people create all four tunnels. Why not route -> traffic generated from home to 10.91.10.24/24 out ipsec0 with iproute2? - -This is feasible, given some iproute2 attention to source addresses, but -it isn't something we've documented yet... (partly because we're still -making some attempt to support 2.0.xx kernels, which can't do this, but -mostly because we haven't caught up with it yet). - -> And 99% of the time you don't need to access "office" directly, which -> means you can eliminate all but the subnet<->subnet connection. - -Correct in principle, but people will keep trying to ping to or from the -gateways during testing, and sometimes they want to run services on the -gateway machines too.</PRE> - -<!-- Is this in the right spot in this document? --> -<H2><A name="opp.gate">An Opportunistic Gateway</A></H2> -<H3><A NAME="14_7_1">Start from full opportunism</A></H3> -<P>Full opportunism allows you to initiate and receive opportunistic - connections on your machine. The remaining instructions in this section - assume you have first set up full opportunism on your gateway using<A HREF="#opp.incoming"> - these instructions</A>. Both sets of instructions require mailing DNS - records to your ISP. Collect DNS records for both the gateway (above) - and the subnet nodes (below) before contacting your ISP.</P> -<H3><A NAME="14_7_2">Reverse DNS TXT records for each protected machine</A> -</H3> -<P>You need these so that your Opportunistic peers can:</P> -<UL> -<LI>discover the gateway's address, knowing only the IP address that - packets are bound for</LI> -<LI>verify that the gateway is authorised to encrypt for that endpoint</LI> -</UL> -<P>On the gateway, generate a TXT record with:</P> -<PRE> ipsec showhostkey --txt 192.0.2.11</PRE> -<P>Use your gateway address in place of 192.0.2.11.</P> -<P>You should see (keys are trimmed for clarity throughout our example):</P> -<PRE> ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/"</PRE> -<P><B>This MUST BE the same key as in your gateway's TXT record, or - nothing will work.</B></P> -<P>In a text file, make one copy of this TXT record for each subnet - node:</P> -<PRE> ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/" - - ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/" - - ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/"</PRE> -<P>Above each entry, insert a line like this:</P> -<PRE> 98.2.0.192.in-addr.arpa. IN PTR arthur.example.com.</PRE> -<P>It must include:</P> -<UL> -<LI>The subnet node's address in reverse map format. For example, - 192.0.2.120 becomes<VAR> 120.2.0.192.in-addr.arpa.</VAR>. Note the - final period.</LI> -<LI><VAR>IN PTR</VAR></LI> -<LI>The node's name, ie.<VAR> arthur.example.com.</VAR>. Note the final - period.</LI> -</UL> -<P>The result will be a file of TXT records, like this:</P> -<PRE> 98.2.0.192.in-addr.arpa. IN PTR arthur.example.com. - ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/" - - 99.2.0.192.in-addr.arpa. IN PTR ford.example.com. - ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/" - - 100.2.0.192.in-addr.arpa. IN PTR trillian.example.com. - ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/"</PRE> -<H3><A NAME="14_7_3">Publish your records</A></H3> -<P>Ask your ISP to publish all the reverse DNS records you have - collected. There may be a delay of up to 48 hours as the records - propagate.</P> -<H3><A NAME="14_7_4">...and test them</A></H3> -<P>Check a couple of records with commands like this one:</P> -<PRE> ipsec verify --host ford.example.com - ipsec verify --host trillian.example.com</PRE> -<P>The<VAR> verify</VAR> command checks for TXT records for both the - subnet host and its gateway. You should see output like:</P> -<PRE> ... - Looking for TXT in reverse map: 99.2.0.192.in-addr.arpa [OK] - ... - Looking for TXT in reverse map: 11.2.0.192.in-addr.arpa [OK] - ... - Looking for TXT in reverse map: 100.2.0.192.in-addr.arpa [OK] - ... - Looking for TXT in reverse map: 11.2.0.192.in-addr.arpa [OK] - ...</PRE> -<H3><A NAME="14_7_5">No Configuration Needed</A></H3> -<P>FreeS/WAN 2.x ships with a built-in, automatically enabled OE - connection<VAR> conn packetdefault</VAR> which applies OE, if possible, - to all outbound traffic routed through the FreeS/WAN box. The<A HREF="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5) manual</A> describes this connection in detail. While the - effect is much the same as<VAR> private-or-clear</VAR>, the - implementation is different: notably, it does not use policy groups.</P> -<P>You can create more complex OE configurations for traffic forwarded - through a FreeS/WAN box, as explained in our<A HREF="#policygroups"> - policy groups document</A>, or disable OE using<A HREF="#disable_policygroups"> - these instructions</A>.</P> -<H2><A name="extruded.config">Extruded Subnets</A></H2> -<P>What we call<A href="glossary.html#extruded"> extruded subnets</A> - are a special case of<A href="glossary.html#VPN.gloss"> VPNs</A>.</P> -<P>If your buddy has some unused IP addresses, in his subnet far off at - the other side of the Internet, he can loan them to you... provided - that the connection between you and him is fast enough to carry all the - traffic between your machines and the rest of the Internet. In effect, - he "extrudes" a part of his address space over the network to you, with - your Internet traffic appearing to originate from behind his Internet - gateway.</P> -<P>As far as the Internet is concerned, your new extruded net is behind - your buddy's gateway. You route all your packets for the Internet at - large out his gateway, and receive return packets the same way. You - route your local packets locally.</P> -<P>Suppose your friend has a.b.c.0/24 and wants to give you - a.b.c.240/28. The initial situation is:</P> -<PRE> subnet gateway Internet - a.b.c.0/24 a.b.c.1 p.q.r.s</PRE> - where anything from the Internet destined for any machine in a.b.c.0/24 - is routed via p.q.r.s and that gateway knows what to do from there. -<P>Of course it is quite normal for various smaller subnets to exist - behind your friend's gateway. For example, your friend's company might - have a.b.c.16/28=development, a.b.c.32/28=marketing and so on. The - Internet neither knows not cares about this; it just delivers packets - to the p.q.r.s and lets the gateway do whatever needs to be done from - there.</P> -<P>What we want to do is take a subnet, perhaps a.b.c.240/28, out of - your friend's physical location<EM> while still having your friend's - gateway route to it</EM>. As far as the Internet is concerned, you - remain behind that gateway.</P> -<PRE> subnet gateway Internet your gate extruded - - a.b.c.0/24 a.b.c.1 p.q.r.s d.e.f.g a.b.c.240/28 - - ========== tunnel ==========</PRE> -<P>The extruded addresses have to be a complete subnet.</P> -<P>In our example, the friend's security gateway is also his Internet - gateway, but this is not necessary. As long as all traffic from the - Internet to his addresses passes through the Internet gate, the - security gate could be a machine behind that. The IG would need to - route all traffic for the extruded subnet to the SG, and the SG could - handle the rest.</P> -<P>First, configure your subnet using the extruded addresses. Your - security gateway's interface to your subnet needs to have an extruded - address (possibly using a Linux<A href="#virtual"> virtual interface</A> -, if it also has to have a different address). Your gateway needs to - have a route to the extruded subnet, pointing to that interface. The - other machines at your site need to have addresses in that subnet, and - default routes pointing to your gateway.</P> -<P>If any of your friend's machines need to talk to the extruded subnet,<EM> - they</EM> need to have a route for the extruded subnet, pointing at his - gateway.</P> -<P>Then set up an IPsec subnet-to-subnet tunnel between your gateway and - his, with your subnet specified as the extruded subnet, and his subnet - specified as "0.0.0.0/0".</P> -<P>The tunnel description should be:</P> -<PRE>conn extruded - left=p.q.r.s - leftsubnet=0.0.0.0/0 - right=d.e.f.g - rightsubnet=a.b.c.0/28</PRE> -<P>If either side was doing firewalling for the extruded subnet before - the IPsec connection is set up, you'll need to poke holes in your<A HREF="#firewall"> - firewall</A> to allow packets through.</P> -<P>And it all just works. Your SG routes traffic for 0.0.0.0/0 -- that - is, the whole Internet -- through the tunnel to his SG, which then - sends it onward as if it came from his subnet. When traffic for the - extruded subnet arrives at his SG, it gets sent through the tunnel to - your SG, which passes it to the right machine.</P> -<P>Remember that when ipsec_manual or ipsec_auto takes a connection - down, it<EM> does not undo the route</EM> it made for that connection. - This lets you take a connection down and bring up a new one, or a - modified version of the old one, without having to rebuild the route it - uses and without any risk of packets which should use IPsec - accidentally going out in the clear. Because the route always points - into KLIPS, the packets will always go there. Because KLIPS temporarily - has no idea what to do with them (no eroute for them), they will be - discarded.</P> -<P>If you<EM> do</EM> want to take the route down, this is what the - "unroute" operation in manual and auto is for. Just do an unroute after - doing the down.</P> -<P>Note that the route for a connection may have replaced an existing - non-IPsec route. Nothing in Linux FreeS/WAN will put that pre-IPsec - route back. If you need it back, you have to create it with the route - command.</P> -<H2><A name="roadvirt">Road Warrior with virtual IP address</A></H2> -<P>Please note that<A HREF="http://www.freeswan.ca/download.php"> Super - FreeS/WAN</A> now features DHCP-over-IPsec, which is an alternate - procedure for Virtual IP address assignment.</P> -<P></P> -<P>Here is a mailing list message about another way to configure for - road warrior support:</P> -<PRE>Subject: Re: linux-ipsec: understanding the vpn - Date: Thu, 28 Oct 1999 10:43:22 -0400 - From: Irving Reid <irving@nevex.com> - -> local-------linux------internet------mobile -> LAN box user -> ... - -> now when the mobile user connects to the linux box -> it is given a virtual IP address, i have configured it to -> be in the 10.x.x.x range. mobile user and linux box -> have a tunnel between them with these IP addresses. - -> Uptil this all is fine. - -If it is possible to configure your mobile client software *not* to -use a virtual IP address, that will make your life easier. It is easier -to configure FreeS/WAN to use the actual address the mobile user gets -from its ISP. - -Unfortunately, some Windows clients don't let you choose. - -> what i would like to know is that how does the mobile -> user communicate with other computers on the local -> LAN , of course with the vpn ? - -> what IP address should the local LAN -> computers have ? I guess their default gateway -> should be the linux box ? and does the linux box need -> to be a 2 NIC card box or one is fine. - -As someone else stated, yes, the Linux box would usually be the default -IP gateway for the local lan. - -However... - -If you mobile user has software that *must* use a virtual IP address, -the whole picture changes. Nobody has put much effort into getting -FreeS/WAN to play well in this environment, but here's a sketch of one -approach: - -Local Lan 1.0.0.0/24 - | - +- Linux FreeS/WAN 1.0.0.2 - | - | 1.0.0.1 - Router - | 2.0.0.1 - | -Internet - | - | 3.0.0.1 -Mobile User - Virtual Address: 1.0.0.3 - -Note that the Local Lan network (1.0.0.x) can be registered, routable -addresses. - -Now, the Mobile User sets up an IPSec security association with the -Linux box (1.0.0.2); it should ESP encapsulate all traffic to the -network 1.0.0.x **EXCEPT** UDP port 500. 500/udp is required for the key -negotiation, which needs to work outside of the IPSec tunnel. - -On the Linux side, there's a bunch of stuff you need to do by hand (for -now). FreeS/WAN should correctly handle setting up the IPSec SA and -routes, but I haven't tested it so this may not work... - -The FreeS/WAN conn should look like: - -conn mobile - right=1.0.0.2 - rightsubnet=1.0.0.0/24 - rightnexthop=1.0.0.1 - left=0.0.0.0 # The infamous "road warrior" - leftsubnet=1.0.0.3/32 - -Note that the left subnet contains *only* the remote host's virtual -address. - -Hopefully the routing table on the FreeS/WAN box ends up looking like -this: - -% netstat -rn -Kernel IP routing table -Destination Gateway Genmask Flags MSS Window irtt Iface -1.0.0.0 0.0.0.0 255.255.255.0 U 1500 0 0 eth0 -127.0.0.0 0.0.0.0 255.0.0.0 U 3584 0 0 lo -0.0.0.0 1.0.0.1 0.0.0.0 UG 1500 0 0 eth0 -1.0.0.3 1.0.0.1 255.255.255.255 UG 1433 0 0 ipsec0 - -So, if anybody sends a packet for 1.0.0.3 to the Linux box, it should -get bundled up and sent through the tunnel. To get the packets for -1.0.0.3 to the Linux box in the first place, you need to use "proxy -ARP". - -How this works is: when a host or router on the local Ethernet segment -wants to send a packet to 1.0.0.3, it sends out an Ethernet level -broadcast "ARP request". If 1.0.0.3 was on the local LAN, it would -reply, saying "send IP packets for 1.0.0.3 to my Ethernet address". - -Instead, you need to set up the Linux box so that _it_ answers ARP -requests for 1.0.0.3, even though that isn't its IP address. That -convinces everyone else on the lan to send 1.0.0.3 packets to the Linux -box, where the usual FreeS/WAN processing and routing take over. - -% arp -i eth0 -s 1.0.0.3 -D eth0 pub - -This says, if you see an ARP request on interface eth0 asking for -1.0.0.3, respond with the Ethernet address of interface eth0. - -Now, as I said at the very beginning, if it is *at all* possible to -configure your client *not* to use the virtual IP address, you can avoid -this whole mess.</PRE> -<H2><A name="dynamic">Dynamic Network Interfaces</A></H2> -<P>Sometimes you have to cope with a situation where the network - interface(s) aren't all there at boot. The common example is notebooks - with PCMCIA.</P> -<H3><A name="basicdyn">Basics</A></H3> -<P>The key issue here is that the<VAR> config setup</VAR> section of the<VAR> - /etc/ipsec.conf</VAR> configuration file lists the connection between - ipsecN and hardware interfaces, in the<VAR> interfaces=</VAR> variable. - At any time when<VAR> ipsec setup start</VAR> or<VAR> ipsec setup - restart</VAR> is run this variable<STRONG> must</STRONG> correspond to - the current real situation. More precisely, it<STRONG> must not</STRONG> - mention any hardware interfaces which don't currently exist. The - difficulty is that an<VAR> ipsec setup start</VAR> command is normally - run at boot time so interfaces that are not up then are mis-handled.</P> -<H3><A name="bootdyn">Boot Time</A></H3> -<P>Normally, an<VAR> ipsec setup start</VAR> is run at boot time. - However, if the hardware situation at boot time is uncertain, one of - two things must be done.</P> -<UL> -<LI>One possibility is simply not to have IPsec brought up at boot time. - To do this: -<PRE> chkconfig --level 2345 ipsec off</PRE> - That's for modern Red Hats or other Linuxes with chkconfig. Systems - which lack this will require fiddling with symlinks in /etc/rc.d/rc?.d - or the equivalent.</LI> -<LI>Another possibility is to bring IPsec up with no interfaces, which - is less aesthetically satisfying but simpler. Just put -<PRE> interfaces=</PRE> - in the configuration file. KLIPS and Pluto will be started, but won't - do anything.</LI> -</UL> -<H3><A name="changedyn">Change Time</A></H3> -<P>When the hardware *is* in place, IPsec has to be made aware of it. - Someday there may be a nice way to do this.</P> -<P>Right now, the way to do it is to fix the<VAR> /etc/ipsec.conf</VAR> - file appropriately, so<VAR> interfaces</VAR> reflects the new - situation, and then restart the IPsec subsystem. This does break any - existing IPsec connections.</P> -<P>If IPsec wasn't brought up at boot time, do</P> -<PRE> ipsec setup start</PRE> - while if it was, do -<PRE> ipsec setup restart</PRE> - which won't be as quick. -<P>If some of the hardware is to be taken out, before doing that, amend - the configuration file so interfaces no longer includes it, and do</P> -<PRE> ipsec setup restart</PRE> -<P>Again, this breaks any existing connections.</P> -<H2><A name="unencrypted">Unencrypted tunnels</A></H2> -<P>Sometimes you might want to create a tunnel without encryption. Often - this is a bad idea, even if you have some data which need not be - private. See this<A href="#traffic.resist"> discussion</A>.</P> -<P>The IPsec protocols provide two ways to do build such tunnels:</P> -<DL> -<DT>using ESP with null encryption</DT> -<DD>not supported by FreeS/WAN</DD> -<DT>using<A href="#AH"> AH</A> without<A href="#ESP"> ESP</A></DT> -<DD>supported for manually keyed connections</DD> -<DD>possible with explicit commands via<A href="manpage.d/ipsec_whack.8.html"> - ipsec_whack(8)</A> (see this<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00190.html"> - list message</A>)</DD> -<DD>not supported in the<A href="manpage.d/ipsec_auto.8.html"> - ipsec_auto(8)</A> scripts.</DD> -</DL> - One situation in which this comes up is when otherwise some data would - be encrypted twice. Alice wants a secure tunnel from her machine to - Bob's. Since she's behind one security gateway and he's behind another, - part of the tunnel that they build passes through the tunnel that their - site admins have built between the gateways. All of Alice and Bob's - messages are encrypted twice. -<P>There are several ways to handle this.</P> -<UL> -<LI>Just accept the overhead of double encryption. The site admins might - choose this if any of the following apply: -<UL> -<LI>policy says encrypt everything (usually, it should)</LI> -<LI>they don't entirely trust Alice and Bob (usually, if they don't have - to, they shouldn't)</LI> -<LI>if they don't feel the saved cycles are worth the time they'd need - to build a non-encrypted tunnel for Alice and Bob's packets (often, - they aren't)</LI> -</UL> -</LI> -<LI>Use a plain IP-in-IP tunnel. These are not well documented. A good - starting point is in the Linux kernel source tree, in - /usr/src/linux/drivers/net/README.tunnel.</LI> -<LI>Use a manually-keyed AH-only tunnel.</LI> -</UL> -<P>Note that if Alice and Bob want end-to-end security, they must build - a tunnel end-to-end between their machines or use some other end-to-end - tool such as PGP or SSL that suits their data. The only question is - whether the admins build some special unencrypted tunnel for those - already-encrypted packets.</P> -<HR> -<H1><A name="install">Installing FreeS/WAN</A></H1> -<P>This document will teach you how to install Linux FreeS/WAN. If your - distribution comes with Linux FreeS/WAN, we offer tips to get you - started.</P> -<H2><A NAME="15_1">Requirements</A></H2> -<P>To install FreeS/WAN you must:</P> -<UL> -<LI>be running Linux with the 2.4 or 2.2 kernel series. See this<A HREF="http://www.freeswan.ca/download.php#contact"> - kernel compatibility table</A>. -<BR>We also have experimental support for 2.6 kernels. Here are two - basic approaches: -<UL> -<LI> install FreeS/WAN, including its<A HREF="#parts"> KLIPS</A> kernel - code. This will remove the native IPsec stack and replace it with - KLIPS.</LI> -<LI> install the FreeS/WAN<A HREF="#parts"> userland tools</A> (keying - daemon and supporting scripts) for use with<A HREF="http://lartc.org/howto/lartc.ipsec.html"> - 2.6 kernel native IPsec</A>,</LI> -</UL> - See also these<A HREF="2.6.known-issues"> known issues with 2.6</A>.</LI> -<LI>have root access to your Linux box</LI> -<LI>choose the version of FreeS/WAN you wish to install based on<A HREF="http://www.freeswan.org/mail.html"> - mailing list reports</A> -<!-- or -our updates page (coming soon)--> -</LI> -</UL> -<H2><A NAME="15_2">Choose your install method</A></H2> -<P>There are three basic ways to get FreeS/WAN onto your system:</P> -<UL> -<LI>activating and testing a FreeS/WAN that<A HREF="#distroinstall"> - shipped with your Linux distribution</A></LI> -<LI><A HREF="#rpminstall">RPM install</A></LI> -<LI><A HREF="#srcinstall">Install from source</A></LI> -</UL> -<A NAME="distroinstall"></A> -<H2><A NAME="15_3">FreeS/WAN ships with some Linuxes</A></H2> -<P>FreeS/WAN comes with<A HREF="#distwith"> these distributions</A>.</P> -<P>If you're running one of these, include FreeS/WAN in the choices you - make during installation, or add it later using the distribution's - tools.</P> -<H3><A NAME="15_3_1">FreeS/WAN may be altered...</A></H3> -<P>Your distribution may have integrated extra features, such as Andreas - Steffen's X.509 patch, into FreeS/WAN. It may also use custom startup - script locations or directory names.</P> -<H3><A NAME="15_3_2">You might need to create an authentication keypair</A> -</H3> -<P>If your FreeS/WAN came with your distribution, you may wish to - generate a fresh RSA key pair. FreeS/WAN will use these keys for - authentication.</P> -<P> To do this, become root, and type:</P> -<PRE> ipsec newhostkey --output /etc/ipsec.secrets --hostname xy.example.com - chmod 600 /etc/ipsec.secrets</PRE> -<P>where you replace xy.example.com with your machine's fully-qualified - domain name. Generate some randomness, for example by wiggling your - mouse, to speed the process.</P> -<P>The resulting ipsec.secrets looks like:</P> -<PRE>: RSA { - # RSA 2192 bits xy.example.com Sun Jun 8 13:42:19 2003 - # for signatures only, UNSAFE FOR ENCRYPTION - #pubkey=0sAQOFppfeE3cC7wqJi... - Modulus: 0x85a697de137702ef0... - # everything after this point is secret - PrivateExponent: 0x16466ea5033e807... - Prime1: 0xdfb5003c8947b7cc88759065... - Prime2: 0x98f199b9149fde11ec956c814... - Exponent1: 0x9523557db0da7a885af90aee... - Exponent2: 0x65f6667b63153eb69db8f300dbb... - Coefficient: 0x90ad00415d3ca17bebff123413fc518... - } -# do not change the indenting of that "}"</PRE> -<P>In the actual file, the strings are much longer.</P> -<H3><A NAME="15_3_3">Start and test FreeS/WAN</A></H3> -<P>You can now<A HREF="#starttest"> start FreeS/WAN and test whether - it's been successfully installed.</A>.</P> -<A NAME="rpminstall"></A> -<H2><A NAME="15_4">RPM install</A></H2> -<P>These instructions are for a recent Red Hat with a stock Red Hat - kernel. We know that Mandrake and SUSE also produce FreeS/WAN RPMs. If - you're running either, install using your distribution's tools.</P> -<H3><A NAME="15_4_1">Download RPMs</A></H3> -<P>Decide which functionality you need:</P> -<UL> -<LI>standard FreeS/WAN RPMs. Use these shortcuts: -<BR> -<UL> -<LI>(for 2.6 kernels: userland only) -<BR> ncftpget - ftp://ftp.xs4all.nl/pub/crypto/freeswan/binaries/RedHat-RPMs/\*userland* -</LI> -<LI>(for 2.4 kernels) -<BR> ncftpget - ftp://ftp.xs4all.nl/pub/crypto/freeswan/binaries/RedHat-RPMs/`uname -r - | tr -d 'a-wy-z'`/\*</LI> -<LI> or view all the offerings at our<A href="ftp://ftp.xs4all.nl/pub/crypto/freeswan/binaries/RedHat-RPMs"> - FTP site</A>.</LI> -</UL> -</LI> -<LI>unofficial<A href="http://www.freeswan.ca/download.php"> Super - FreeS/WAN</A> RPMs, which include Andreas Steffen's X.509 patch and - more. Super FreeS/WAN RPMs do not currently include<A HREF="#NAT.gloss"> - Network Address Translation</A> (NAT) traversal, but Super FreeS/WAN - source does.</LI> -</UL> -<A NAME="2.6.rpm"></A> -<P>For 2.6 kernels, get the latest FreeS/WAN userland RPM, for example:</P> -<PRE> freeswan-userland-2.04.9-0.i386.rpm</PRE> -<P>Note: FreeS/WAN's support for 2.6 kernel IPsec is preliminary. Please - see<A HREf="2.6.known-issues"> 2.6.known-issues</A>, and the latest<A HREF="http://www.freeswan.org/mail.html"> - mailing list reports</A>.</P> -<P>Change to your new FreeS/WAN directory, and make and install the</P> -<P>For 2.4 kernels, get both kernel and userland RPMs. Check your kernel - version with</P> -<PRE> uname -r</PRE> -<P>Get a kernel module which matches that version. For example:</P> -<PRE> freeswan-module-2.04_2.4.20_20.9-0.i386.rpm</PRE> -<P>Note: These modules<B> will only work on the Red Hat kernel they were - built for</B>, since they are very sensitive to small changes in the - kernel.</P> -<P>Get FreeS/WAN utilities to match. For example:</P> -<PRE> freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm</PRE> -<H3><A NAME="15_4_2">For freeswan.org RPMs: check signatures</A></H3> -<P>While you're at our ftp site, grab the RPM signing key</P> -<PRE> freeswan-rpmsign.asc</PRE> -<P>If you're running RedHat 8.x or later, import this key into the RPM - database:</P> -<PRE> rpm --import freeswan-rpmsign.asc</PRE> -<P>For RedHat 7.x systems, you'll need to add it to your<A HREF="#PGP"> - PGP</A> keyring:</P> -<PRE> pgp -ka freeswan-rpmsign.asc</PRE> -<P>Check the digital signatures on both RPMs using:</P> -<PRE> rpm --checksig freeswan*.rpm </PRE> -<P>You should see that these signatures are good:</P> -<PRE> freeswan-module-2.04_2.4.20_20.9-0.i386.rpm: pgp md5 OK - freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm: pgp md5 OK</PRE> -<H3><A NAME="15_4_3">Install the RPMs</A></H3> -<P>Become root:</P> -<PRE> su</PRE> -<P>For a first time install, use:</P> -<PRE> rpm -ivh freeswan*.rpm</PRE> -<P>To upgrade existing RPMs (and keep all .conf files in place), use:</P> -<PRE> rpm -Uvh freeswan*.rpm</PRE> -<P>If you're upgrading from FreeS/WAN 1.x to 2.x RPMs, and encounter - problems, see<A HREF="#upgrading.rpms"> this note</A>.</P> -<H3><A NAME="15_4_4">Start and Test FreeS/WAN</A></H3> -<P>Now,<A HREF="#starttest"> start FreeS/WAN and test your install</A>.</P> -<A NAME="srcinstall"></A> -<H2><A NAME="15_5">Install from Source</A></H2> - -<!-- Most of this section, along with "Start and Test", can replace -INSTALL. --> -<H3><A NAME="15_5_1">Decide what functionality you need</A></H3> -<P>Your choices are:</P> -<UL> -<LI><A HREF="ftp://ftp.xs4all.nl/pub/crypto/freeswan">standard FreeS/WAN</A> -,</LI> -<LI>standard FreeS/WAN plus any of these<A HREF="#patch"> user-supported - patches</A>, or</LI> -<LI><A HREF="http://www.freeswan.ca/download">Super FreeS/WAN</A>, an - unofficial FreeS/WAN pre-patched with many of the above. Provides - additional algorithms, X.509, SA deletion, dead peer detection, and<A HREF="#NAT.gloss"> - Network Address Translation</A> (NAT) traversal.</LI> -</UL> -<H3><A NAME="15_5_2">Download FreeS/WAN</A></H3> -<P>Download the source tarball you've chosen, along with any patches.</P> -<H3><A NAME="15_5_3">For freeswan.org source: check its signature</A></H3> -<P>While you're at our ftp site, get our source signing key</P> -<PRE> freeswan-sigkey.asc</PRE> -<P>Add it to your PGP keyring:</P> -<PRE> pgp -ka freeswan-sigkey.asc</PRE> -<P>Check the signature using:</P> -<PRE> pgp freeswan-2.04.tar.gz.sig freeswan-2.04.tar.gz</PRE> -<P>You should see something like:</P> -<PRE> Good signature from user "Linux FreeS/WAN Software Team (build@freeswan.org)". - Signature made 2002/06/26 21:04 GMT using 2047-bit key, key ID 46EAFCE1</PRE> - -<!-- Note to self: build@freeswan.org has angled brackets in the original. - Changed because it conflicts with HTML tags. --> -<H3><A NAME="15_5_4">Untar, unzip</A></H3> -<P>As root, unpack your FreeS/WAN source into<VAR> /usr/src</VAR>.</P> -<PRE> su - mv freeswan-2.04.tar.gz /usr/src - cd /usr/src - tar -xzf freeswan-2.04.tar.gz -</PRE> -<H3><A NAME="15_5_5">Patch if desired</A></H3> -<P>Now's the time to add any patches. The contributor may have special - instructions, or you may simply use the patch command.</P> -<H3><A NAME="15_5_6">... and Make</A></H3> -<P>Choose one of the methods below.</P> -<H4><A NAME="15_5_6_1">Userland-only Install for 2.6 kernels</A></H4> -<A NAME="2.6.src"></A> -<P>Note: FreeS/WAN's support for 2.6 kernel IPsec is preliminary. Please - see<A HREf="2.6.known-issues"> 2.6.known-issues</A>, and the latest<A HREF="http://www.freeswan.org/mail.html"> - mailing list reports</A>.</P> -<P>Change to your new FreeS/WAN directory, and make and install the - FreeS/WAN userland tools.</P> -<PRE> cd /usr/src/freeswan-2.04 - make programs - make install</PRE> -<P>Now,<A HREF="#starttest"> start FreeS/WAN and test your install</A>.</P> -<H4><A NAME="15_5_6_2">KLIPS install for 2.2, 2.4, or 2.6 kernels</A></H4> -<A NAME="modinstall"></A> -<P>To make a modular version of KLIPS, along with other FreeS/WAN - programs you'll need, use the command sequence below. This will change - to your new FreeS/WAN directory, make the FreeS/WAN module (and other - stuff), and install it all.</P> -<PRE> cd /usr/src/freeswan-2.04 - make oldmod - make minstall</PRE> -<P><A HREF="#starttest">Start FreeS/WAN and test your install</A>.</P> -<P>To link KLIPS statically into your kernel (using your old kernel - settings), and install other FreeS/WAN components, do:</P> -<PRE> cd /usr/src/freeswan-2.04 - make oldmod - make minstall</PRE> -<P>Reboot your system and<A HREF="#testonly"> test your install</A>.</P> -<P>For other ways to compile KLIPS, see our Makefile.</P> -<A name="starttest"></A> -<H2><A NAME="15_6">Start FreeS/WAN and test your install</A></H2> -<P>Bring FreeS/WAN up with:</P> -<PRE> service ipsec start</PRE> -<P>This is not necessary if you've rebooted.</P> -<A name="testonly"></A> -<H2><A NAME="15_7">Test your install</A></H2> -<P>To check that you have a successful install, run:</P> -<PRE> ipsec verify</PRE> -<P>You should see at least:</P> -<PRE> - Checking your system to see if IPsec got installed and started correctly - Version check and ipsec on-path [OK] - Checking for KLIPS support in kernel [OK] - Checking for RSA private key (/etc/ipsec.secrets) [OK] - Checking that pluto is running [OK] -</PRE> -<P>If any of these first four checks fails, see our<A href="#install.check"> - troubleshooting guide</A>.</P> -<H2><A NAME="15_8">Making FreeS/WAN play well with others</A></H2> -<P>There are at least a couple of things on your system that might - interfere with FreeS/WAN, and now's a good time to check these:</P> -<UL> -<LI>Firewalling. You need to allow UDP 500 through your firewall, plus - ESP (protocol 50) and AH (protocol 51). For more information, see our - updated firewalls document (coming soon).</LI> -<LI>Network address translation. Do not NAT the packets you will be - tunneling.</LI> -</UL> -<H2><A NAME="15_9">Configure for your needs</A></H2> -<P>You'll need to configure FreeS/WAN for your local site. Have a look - at our<A HREF="quickstart.html"> opportunism quickstart guide</A> to - see if that easy method is right for your needs. Or, see how to<A HREF="config.html"> - configure a network-to-network or Road Warrior style VPN</A>.</P> -<HR> -<H1><A NAME="config">How to configure FreeS/WAN</A></H1> -<P>This page will teach you how to configure a simple network-to-network - link or a Road Warrior connection between two Linux FreeS/WAN boxes.</P> -<P>See also these related documents:</P> -<UL> -<LI>our<A HREF="#quickstart"> quickstart</A> guide to<A HREF="#carpediem"> - opportunistic encryption</A></LI> -<LI>our guide to configuration with<A HREF="#policygroups"> policy - groups</A></LI> -<LI>our<A HREF="#adv_config"> advanced configuration</A> document</LI> -</UL> -<P> The network-to-network setup allows you to connect two office - networks into one Virtual Private Network, while the Road Warrior - connection secures a laptop's telecommute to work. Our examples also - show the basic procedure on the Linux FreeS/WAN side where another - IPsec peer is in play.</P> -<P> Shortcut to<A HREF="#config.netnet"> net-to-net</A>. -<BR> Shortcut to<A HREF="#config.rw"> Road Warrior</A>.</P> -<H2><A NAME="16_1">Requirements</A></H2> -<P>To configure the network-to-network connection you must have:</P> -<UL> -<LI>two Linux gateways with static IPs</LI> -<LI>a network behind each gate. Networks must have non-overlapping IP - ranges.</LI> -<LI>Linux FreeS/WAN<A HREF="#install"> installed</A> on both gateways</LI> -<LI><A HREF="http://www.tcpdump.org"><VAR>tcpdump</VAR></A> on the local - gate, to test the connection</LI> -</UL> -<P>For the Road Warrior you need:</P> -<UL> -<LI>one Linux box with a static IP</LI> -<LI>a Linux laptop with a dynamic IP</LI> -<LI>Linux FreeS/WAN installed on both</LI> -<LI>for testing,<VAR> tcpdump</VAR> on your gateway or laptop</LI> -</UL> -<P>If both IPs are dynamic, your situation is a bit trickier. Your best - bet is a variation on the<A HREF="#config.rw"> Road Warrior</A>, as - described in<A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00282.html"> - this mailing list message</A>.</P> -<H2><A name="config.netnet"></A>Net-to-Net connection</H2> -<H3><A name="netnet.info.ex">Gather information</A></H3> -<P>For each gateway, compile the following information:</P> -<UL> -<LI>gateway IP</LI> -<LI>IP range of the subnet you will be protecting. This doesn't have to - be your whole physical subnet.</LI> -<LI>a name by which that gateway can identify itself for IPsec - negotiations. Its form is a Fully Qualified Domain Name preceded by an - @ sign, ie. @xy.example.com. -<BR> It does not need to be within a domain that you own. It can be a - made-up name.</LI> -</UL> -<H4><A NAME="16_2_1_1">Get your leftrsasigkey</A></H4> -<P>On your local Linux FreeS/WAN gateway, print your IPsec public key:</P> -<PRE> ipsec showhostkey --left</PRE> -<P>The output should look like this (with the key shortened for easy - reading):</P> -<PRE> # RSA 2048 bits xy.example.com Fri Apr 26 15:01:41 2002 - leftrsasigkey=0sAQOnwiBPt...</PRE> -<P>Don't have a key? Use<A HREF="manpage.d/ipsec_newhostkey.8.html"><VAR> - ipsec newhostkey</VAR></A> to create one.</P> -<H4><A NAME="16_2_1_2">...and your rightrsasigkey</A></H4> -<P>Get a console on the remote side:</P> -<PRE> ssh2 ab.example.com</PRE> -<P>In that window, type:</P> -<PRE> ipsec showhostkey --right</PRE> -<P>You'll see something like:</P> -<PRE> # RSA 2192 bits ab.example.com Thu May 16 15:26:20 2002 - rightrsasigkey=0sAQOqH55O...</PRE> -<H3><A NAME="16_2_2">Edit<VAR> /etc/ipsec.conf</VAR></A></H3> -<P>Back on the local gate, copy our template to<VAR> /etc/ipsec.conf</VAR> -. (on Mandrake,<VAR> /etc/freeswan/ipsec.conf</VAR>). Substitute the - information you've gathered for our example data.</P> -<PRE>conn net-to-net - left=192.0.2.2 # Local vitals - leftsubnet=192.0.2.128/29 # - leftid=@xy.example.com # - leftrsasigkey=0s1LgR7/oUM... # - leftnexthop=%defaultroute # correct in many situations - right=192.0.2.9 # Remote vitals - rightsubnet=10.0.0.0/24 # - rightid=@ab.example.com # - rightrsasigkey=0sAQOqH55O... # - rightnexthop=%defaultroute # correct in many situations - auto=add # authorizes but doesn't start this - # connection at startup</PRE> -<P> "Left" and "right" should represent the machines that have FreeS/WAN - installed on them, and "leftsubnet" and "rightsubnet" machines that are - being protected. /32 is assumed for left/right and left/rightsubnet - parameters.</P> -<P>Copy<VAR> conn net-to-net</VAR> to the remote-side /etc/ipsec.conf. - If you've made no other modifications to either<VAR> ipsec.conf</VAR>, - simply:</P> -<PRE> scp2 ipsec.conf root@ab.example.com:/etc/ipsec.conf</PRE> -<H3><A NAME="16_2_3">Start your connection</A></H3> -<P>Locally, type:</P> -<PRE> ipsec auto --up net-to-net</PRE> -<P>You should see:</P> -<PRE> 104 "net-net" #223: STATE_MAIN_I1: initiate - 106 "net-net" #223: STATE_MAIN_I2: sent MI2, expecting MR2 - 108 "net-net" #223: STATE_MAIN_I3: sent MI3, expecting MR3 - 004 "net-net" #223: STATE_MAIN_I4: ISAKMP SA established - 112 "net-net" #224: STATE_QUICK_I1: initiate - 004 "net-net" #224: STATE_QUICK_I2: sent QI2, IPsec SA established</PRE> -<P>The important thing is<VAR> IPsec SA established</VAR>. If you're - unsuccessful, see our<A HREF="#trouble"> troubleshooting tips</A>.</P> -<H3><A NAME="16_2_4">Do not MASQ or NAT packets to be tunneled</A></H3> -<P>If you are using<A HREF="#masq"> IP masquerade</A> or<A HREF="#NAT.gloss"> - Network Address Translation (NAT)</A> on either gateway, you must now - exempt the packets you wish to tunnel from this treatment. For example, - if you have a rule like:</P> -<PRE>iptables -t nat -A POSTROUTING -o eth0 -s 10.0.0.0/24 -j MASQUERADE -</PRE> -<P>change it to something like:</P> -<PRE>iptables -t nat -A POSTROUTING -o eth0 -s 10.0.0.0/24 -d \! 192.0.2.128/29 -j MASQUERADE</PRE> -<P>This may be necessary on both gateways.</P> -<H3><A NAME="16_2_5">Test your connection</A></H3> -<P>Sit at one of your local subnet nodes (not the gateway), and ping a - subnet node on the other (again, not the gateway).</P> -<PRE> ping fileserver.toledo.example.com</PRE> -<P>While still pinging, go to the local gateway and snoop your outgoing - interface, for example:</P> -<PRE> tcpdump -i ppp0</PRE> -<P>You want to see ESP (Encapsulating Security Payload) packets moving<B> - back and forth</B> between the two gateways at the same frequency as - your pings:</P> -<PRE> 19:16:32.046220 192.0.2.2 > 192.0.2.9: ESP(spi=0x3be6c4dc,seq=0x3) - 19:16:32.085630 192.0.2.9 > 192.0.2.2: ESP(spi=0x5fdd1cf8,seq=0x6)</PRE> -<P>If you see this, congratulations are in order! You have a tunnel - which will protect any IP data from one subnet to the other, as it - passes between the two gates. If not, go and<A HREF="#trouble"> - troubleshoot</A>.</P> -<P>Note: your new tunnel protects only net-net traffic, not - gateway-gateway, or gateway-subnet. If you need this (for example, if - machines on one net need to securely contact a fileserver on the IPsec - gateway), you'll need to create<A HREF="#adv_config"> extra connections</A> -.</P> -<H3><A NAME="16_2_6">Finishing touches</A></H3> -<P>Now that your connection works, name it something sensible, like:</P> -<PRE>conn winstonnet-toledonet</PRE> -<P>To have the tunnel come up on-boot, replace</P> -<PRE> auto=add</PRE> -<P>with:</P> -<PRE> auto=start</PRE> -<P>Copy these changes to the other side, for example:</P> -<PRE> scp2 ipsec.conf root@ab.example.com:/etc/ipsec.conf</PRE> -<P>Enjoy!</P> -<H2><A name="config.rw"></A>Road Warrior Configuration</H2> -<H3><A name="rw.info.ex">Gather information</A></H3> -<P>You'll need to know:</P> -<UL> -<LI>the gateway's static IP</LI> -<LI>the IP range of the subnet behind that gateway</LI> -<LI>a name by which each side can identify itself for IPsec - negotiations. Its form is a Fully Qualified Domain Name preceded by an - @ sign, ie. @road.example.com. -<BR> It does not need to be within a domain that you own. It can be a - made-up name.</LI> -</UL> -<H4><A NAME="16_3_1_1">Get your leftrsasigkey...</A></H4> -<P>On your laptop, print your IPsec public key:</P> -<PRE> ipsec showhostkey --left</PRE> -<P>The output should look like this (with the key shortened for easy - reading):</P> -<PRE> # RSA 2192 bits road.example.com Sun Jun 9 02:45:02 2002 - leftrsasigkey=0sAQPIPN9uI...</PRE> -<P>Don't have a key? See<A HREF="old_config.html#genrsakey"> these - instructions</A>.</P> -<H4><A NAME="16_3_1_2">...and your rightrsasigkey</A></H4> -<P>Get a console on the gateway:</P> -<PRE> ssh2 xy.example.com</PRE> -<P>View the gateway's public key with:</P> -<PRE> ipsec showhostkey --right</PRE> -<P>This will yield something like</P> -<PRE> # RSA 2048 bits xy.example.com Fri Apr 26 15:01:41 2002 - rightrsasigkey=0sAQOnwiBPt...</PRE> -<H3><A NAME="16_3_2">Customize<VAR> /etc/ipsec.conf</VAR></A></H3> -<P>On your laptop, copy this template to<VAR> /etc/ipsec.conf</VAR>. (on - Mandrake,<VAR> /etc/freeswan/ipsec.conf</VAR>). Substitute the - information you've gathered for our example data.</P> -<PRE>conn road - left=%defaultroute # Picks up our dynamic IP - leftnexthop=%defaultroute # - leftid=@road.example.com # Local information - leftrsasigkey=0sAQPIPN9uI... # - right=192.0.2.10 # Remote information - rightsubnet=10.0.0.0/24 # - rightid=@xy.example.com # - rightrsasigkey=0sAQOnwiBPt... # - auto=add # authorizes but doesn't start this - # connection at startup</PRE> -<P>The template for the gateway is different. Notice how it reverses<VAR> - left</VAR> and<VAR> right</VAR>, in keeping with our convention that<STRONG> - L</STRONG>eft is<STRONG> L</STRONG>ocal,<STRONG> R</STRONG>ight<STRONG> - R</STRONG>emote. Be sure to switch your rsasigkeys in keeping with - this.</P> -<PRE> ssh2 xy.example.com - vi /etc/ipsec.conf</PRE> -<P>and add:</P> -<PRE>conn road - left=192.0.2.2 # Gateway's information - leftid=@xy.example.com # - leftsubnet=192.0.2.128/29 # - leftrsasigkey=0sAQOnwiBPt... # - rightnexthop=%defaultroute # correct in many situations - right=%any # Wildcard: we don't know the laptop's IP - rightid=@road.example.com # - rightrsasigkey=0sAQPIPN9uI... # - auto=add # authorizes but doesn't start this - # connection at startup</PRE> -<H3><A NAME="16_3_3">Start your connection</A></H3> -<P>You must start the connection from the Road Warrior side. On your - laptop, type:</P> -<PRE> ipsec auto --start net-to-net</PRE> -<P>You should see:</P> -<PRE>104 "net-net" #223: STATE_MAIN_I1: initiate -106 "road" #301: STATE_MAIN_I2: sent MI2, expecting MR2 -108 "road" #301: STATE_MAIN_I3: sent MI3, expecting MR3 -004 "road" #301: STATE_MAIN_I4: ISAKMP SA established -112 "road" #302: STATE_QUICK_I1: initiate -004 "road" #302: STATE_QUICK_I2: sent QI2, IPsec SA established</PRE> -<P>Look for<VAR> IPsec SA established</VAR>. If you're unsuccessful, see - our<A HREF="#trouble"> troubleshooting tips</A>.</P> -<H3><A NAME="16_3_4">Do not MASQ or NAT packets to be tunneled</A></H3> -<P>If you are using<A HREF="#masq"> IP masquerade</A> or<A HREF="#NAT.gloss"> - Network Address Translation (NAT)</A> on either gateway, you must now - exempt the packets you wish to tunnel from this treatment. For example, - if you have a rule like:</P> -<PRE>iptables -t nat -A POSTROUTING -o eth0 -s 10.0.0.0/24 -j MASQUERADE -</PRE> -<P>change it to something like:</P> -<PRE>iptables -t nat -A POSTROUTING -o eth0 -s 10.0.0.0/24 -d \! 192.0.2.128/29 -j MASQUERADE</PRE> -<H3><A NAME="16_3_5">Test your connection</A></H3> -<P>From your laptop, ping a subnet node behind the remote gateway. Do - not choose the gateway itself for this test.</P> -<PRE> ping ns.winston.example.com</PRE> -<P>Snoop the packets exiting the laptop, with a command like:</P> -<PRE> tcpdump -i wlan0</PRE> -<P>You have success if you see (Encapsulating Security Payload) packets - travelling<B> in both directions</B>:</P> -<PRE> 19:16:32.046220 192.0.2.2 > 192.0.2.9: ESP(spi=0x3be6c4dc,seq=0x3) - 19:16:32.085630 192.0.2.9 > 192.0.2.2: ESP(spi=0x5fdd1cf8,seq=0x6)</PRE> -<P>If you do, great! Traffic between your Road Warrior and the net - behind your gateway is protected. If not, see our<A HREF="#trouble"> - troubleshooting hints</A>.</P> -<P>Your new tunnel protects only traffic addressed to the net, not to - the IPsec gateway itself. If you need the latter, you'll want to make - an<A HREF="#adv_config"> extra tunnel.</A>.</P> -<H3><A NAME="16_3_6">Finishing touches</A></H3> -<P>On both ends, name your connection wisely, like:</P> -<PRE>conn mike-to-office</PRE> -<P><B>On the laptop only,</B> replace</P> -<PRE> auto=add</PRE> -<P>with:</P> -<PRE> auto=start</PRE> -<P>so that you'll be connected on-boot.</P> -<P>Happy telecommuting!</P> -<H3><A NAME="16_3_7">Multiple Road Warriors</A></H3> -<P>If you're using RSA keys, as we did in this example, you can add as - many Road Warriors as you like. The left/rightid parameter lets Linux - FreeS/WAN distinguish between multiple Road Warrior peers, each with - its own public key.</P> -<P>The situation is different for shared secrets (PSK). During a PSK - negotiation, ID information is not available at the time Pluto is - trying to determine which secret to use, so, effectively, you can only - define one Roadwarrior connection. All your PSK road warriors must - therefore share one secret.</P> -<H2><A NAME="16_4">What next?</A></H2> -<P>Using the principles illustrated here, you can try variations such - as:</P> -<UL> -<LI>a telecommuter with a static IP</LI> -<LI>a road warrior with a subnet behind it</LI> -</UL> -<P>Or, look at some of our<A HREF="#adv_config"> more complex - configuration examples.</A>.</P> -<HR> -<H1><A name="background">Linux FreeS/WAN background</A></H1> -<P>This section discusses a number of issues which have three things in - common:</P> -<UL> -<LI>They are not specifically FreeS/WAN problems</LI> -<LI>You may have to understand them to get FreeS/WAN working right</LI> -<LI>They are not simple questions</LI> -</UL> -<P>Grouping them here lets us provide the explanations some users will - need without unduly complicating the main text.</P> -<P>The explanations here are intended to be adequate for FreeS/WAN - purposes (please comment to the<A href="mail.html"> users mailing list</A> - if you don't find them so), but they are not trying to be complete or - definitive. If you need more information, see the references provided - in each section.</P> -<H2><A name="dns.background">Some DNS background</A></H2> -<P><A href="#carpediem">Opportunistic encryption</A> requires that the - gateway systems be able to fetch public keys, and other IPsec-related - information, from each other's DNS (Domain Name Service) records.</P> -<P><A href="#DNS">DNS</A> is a distributed database that maps names to - IP addresses and vice versa.</P> -<P>Much good reference material is available for DNS, including:</P> -<UL> -<LI>the<A href="http://www.linuxdoc.org/HOWTO/DNS-HOWTO.html"> DNS HowTo</A> -</LI> -<LI>the standard<A href="#DNS.book"> DNS reference</A> book</LI> -<LI><A href="http://www.linuxdoc.org/LDP/nag2/index.html">Linux Network - Administrator's Guide</A></LI> -<LI><A href="http://www.nominum.com/resources/whitepapers/bind-white-paper.html"> -BIND overview</A></LI> -<LI><A href="http://www.nominum.com/resources/documentation/Bv9ARM.pdf"> -BIND 9 Administrator's Reference</A></LI> -</UL> -<P>We give only a brief overview here, intended to help you use DNS for - FreeS/WAN purposes.</P> -<H3><A name="forward.reverse">Forward and reverse maps</A></H3> -<P>Although the implementation is distributed, it is often useful to - speak of DNS as if it were just two enormous tables:</P> -<UL> -<LI>the forward map: look up a name, get an IP address</LI> -<LI>the reverse map: look up an IP address, get a name</LI> -</UL> -<P>Both maps can optionally contain additional data. For opportunistic - encryption, we insert the data need for IPsec authentication.</P> -<P>A system named gateway.example.com with IP address 10.20.30.40 should - have at least two DNS records, one in each map:</P> -<DL> -<DT>gateway.example.com. IN A 10.20.30.40</DT> -<DD>used to look up the name and get an IP address</DD> -<DT>40.30.20.10.in-addr.arpa. IN PTR gateway.example.com.</DT> -<DD>used for reverse lookups, looking up an address to get the - associated name. Notice that the digits here are in reverse order; the - actual address is 10.20.30.40 but we use 40.30.20.10 here.</DD> -</DL> -<H3><A NAME="17_1_2">Hierarchy and delegation</A></H3> -<P>For both maps there is a hierarchy of DNS servers and a system of - delegating authority so that, for example:</P> -<UL> -<LI>the DNS administrator for example.com can create entries of the form<VAR> - name</VAR>.example.com</LI> -<LI>the example.com admin cannot create an entry for counterexample.com; - only someone with authority for .com can do that</LI> -<LI>an admin might have authority for 20.10.in-addr.arpa.</LI> -<LI>in either map, authority can be delegated -<UL> -<LI>the example.com admin could give you authority for - westcoast.example.com</LI> -<LI>the 20.10.in-addr.arpa admin could give you authority for - 30.20.10.in-addr.arpa</LI> -</UL> -</LI> -</UL> -<P>DNS zones are the units of delegation. There is a hierarchy of zones.</P> -<H3><A NAME="17_1_3">Syntax of DNS records</A></H3> -<P>Returning to the example records:</P> -<PRE> gateway.example.com. IN A 10.20.30.40 - 40.30.20.10.in-addr.arpa. IN PTR gateway.example.com.</PRE> -<P>some syntactic details are:</P> -<UL> -<LI>the IN indicates that these records are for<STRONG> In</STRONG> -ternet addresses</LI> -<LI>The final periods in '.com.' and '.arpa.' are required. They - indicate the root of the domain name system.</LI> -</UL> -<P>The capitalised strings after IN indicate the type of record. - Possible types include:</P> -<UL> -<LI><STRONG>A</STRONG>ddress, for forward lookups</LI> -<LI><STRONG>P</STRONG>oin<STRONG>T</STRONG>e<STRONG>R</STRONG>, for - reverse lookups</LI> -<LI><STRONG>C</STRONG>anonical<STRONG> NAME</STRONG>, records to support - aliasing, multiple names for one address</LI> -<LI><STRONG>M</STRONG>ail e<STRONG>X</STRONG>change, used in mail - routing</LI> -<LI><STRONG>SIG</STRONG>nature, used in<A href="#SDNS"> secure DNS</A></LI> -<LI><STRONG>KEY</STRONG>, used in<A href="#SDNS"> secure DNS</A></LI> -<LI><STRONG>T</STRONG>e<STRONG>XT</STRONG>, a multi-purpose record type</LI> -</UL> -<P>To set up for opportunistic encryption, you add some TXT records to - your DNS data. Details are in our<A href="quickstart.html"> quickstart</A> - document.</P> -<H3><A NAME="17_1_4">Cacheing, TTL and propagation delay</A></H3> -<P>DNS information is extensively cached. With no caching, a lookup by - your system of "www.freeswan.org" might involve:</P> -<UL> -<LI>your system asks your nameserver for "www.freeswan.org"</LI> -<LI>local nameserver asks root server about ".org", gets reply</LI> -<LI>local nameserver asks .org nameserver about "freeswan.org", gets - reply</LI> -<LI>local nameserver asks freeswan.org nameserver about - "www.freeswan.org", gets reply</LI> -</UL> -<P>However, this can be a bit inefficient. For example, if you are in - the Phillipines, the closest a root server is in Japan. That might send - you to a .org server in the US, and then to freeswan.org in Holland. If - everyone did all those lookups every time they clicked on a web link, - the net would grind to a halt.</P> -<P>Nameservers therefore cache information they look up. When you click - on another link at www.freeswan.org, your local nameserver has the IP - address for that server in its cache, and no further lookups are - required.</P> -<P>Intermediate results are also cached. If you next go to - lists.freeswan.org, your nameserver can just ask the freeswan.org - nameserver for that address; it does not need to query the root or .org - nameservers because it has a cached address for the freeswan.org zone - server.</P> -<P>Of course, like any cacheing mechanism, this can create problems of - consistency. What if the administrator for freeswan.org changes the IP - address, or the authentication key, for www.freeswan.org? If you use - old information from the cache, you may get it wrong. On the other - hand, you cannot afford to look up fresh information every time. Nor - can you expect the freeswan.org server to notify you; that isn't in the - protocols.</P> -<P>The solution that is in the protocols is fairly simple. Cacheable - records are marked with Time To Live (TTL) information. When the time - expires, the caching server discards the record. The next time someone - asks for it, the server fetches a fresh copy. Of course, a server may - also discard records before their TTL expires if it is running out of - cache space.</P> -<P>This implies that there will be some delay before the new version of - a changed record propagates around the net. Until the TTLs on all - copies of the old record expire, some users will see it because that is - what is in their cache. Other users may see the new record immediately - because they don't have an old one cached.</P> -<H2><A name="MTU.trouble">Problems with packet fragmentation</A></H2> -<P>It seems, from mailing list reports, to be moderately common for - problems to crop up in which small packets pass through the IPsec - tunnels just fine but larger packets fail.</P> -<P>These problems are caused by various devices along the way - mis-handling either packet fragments or<A href="#pathMTU"> path MTU - discovery</A>.</P> -<P>IPsec makes packets larger by adding an ESP or AH header. This can - tickle assorted bugs in fragment handling in routers and firewalls, or - in path MTU discovery mechanisms, and cause a variety of symptoms which - are both annoying and, often, quite hard to diagnose.</P> -<P>An explanation from project technical lead Henry Spencer:</P> -<PRE>The problem is IP fragmentation; more precisely, the problem is that the -second, third, etc. fragments of an IP packet are often difficult for -filtering mechanisms to classify. - -Routers cannot rely on reassembling the packet, or remembering what was in -earlier fragments, because the fragments may be out of order or may even -follow different routes. So any general, worst-case filtering decision -pretty much has to be made on each fragment independently. (If the router -knows that it is the only route to the destination, so all fragments -*must* pass through it, reassembly would be possible... but most routers -don't want to bother with the complications of that.) - -All fragments carry roughly the original IP header, but any higher-level -header is (for IP purposes) just the first part of the packet data... so -only the first fragment carries that. So, for example, on examining the -second fragment of a TCP packet, you could tell that it's TCP, but not -what port number it is destined for -- that information is in the TCP -header, which appears in the first fragment only. - -The result of this classification difficulty is that stupid routers and -over-paranoid firewalls may just throw fragments away. To get through -them, you must reduce your MTU enough that fragmentation will not occur. -(In some cases, they might be willing to attempt reassembly, but have very -limited resources to devote to it, meaning that packets must be small and -fragments few in number, leading to the same conclusion: smaller MTU.)</PRE> -<P>In addition to the problem Henry describes, you may also have trouble - with<A href="#pathMTU"> path MTU discovery</A>.</P> -<P>By default, FreeS/WAN uses a large<A href="#MTU"> MTU</A> for the - ipsec device. This avoids some problems, but may complicate others. - Here's an explanation from Claudia:</P> -<PRE>Here are a couple of pieces of background information. Apologies if you -have seen these already. An excerpt from one of my old posts: - - An MTU of 16260 on ipsec0 is usual. The IPSec device defaults to this - high MTU so that it does not fragment incoming packets before encryption - and encapsulation. If after IPSec processing packets are larger than 1500, - [ie. the mtu of eth0] then eth0 will fragment them. - - Adding IPSec headers adds a certain number of bytes to each packet. - The MTU of the IPSec interface refers to the maximum size of the packet - before the IPSec headers are added. In some cases, people find it helpful - to set ipsec0's MTU to 1500-(IPSec header size), which IIRC is about 1430. - - That way, the resulting encapsulated packets don't exceed 1500. On most - networks, packets less than 1500 will not need to be fragmented. - -and... (from Henry Spencer) - - The way it *ought* to work is that the MTU advertised by the ipsecN - interface should be that of the underlying hardware interface, less a - pinch for the extra headers needed. - - Unfortunately, in certain situations this breaks many applications. - There is a widespread implicit assumption that the smallest MTUs are - at the ends of paths, not in the middle, and another that MTUs are - never less than 1500. A lot of code is unprepared to handle paths - where there is an "interior minimum" in the MTU, especially when it's - less than 1500. So we advertise a big MTU and just let the resulting - big packets fragment. - -This usually works, but we do get bitten in cases where some intermediate -point can't handle all that fragmentation. We can't win on this one.</PRE> -<P>The MTU can be changed with an<VAR> overridemtu=</VAR> statement in - the<VAR> config setup</VAR> section of<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf.5</A>.</P> -<P>For a discussion of MTU issues and some possible solutions using - Linux advanced routing facilities, see the<A href="http://www.linuxguruz.org/iptables/howto/2.4routing-15.html#ss15.6"> - Linux 2.4 Advanced Routing HOWTO</A>. For a discussion of MTU and NAT - (Network Address Translation), see<A HREF="http://harlech.math.ucla.edu/services/ipsec.html"> - James Carter's MTU notes</A>.</P> -<H2><A name="nat.background">Network address translation (NAT)</A></H2> -<P><STRONG>N</STRONG>etwork<STRONG> A</STRONG>ddress<STRONG> T</STRONG> -ranslation is a service provided by some gateway machines. Calling it - NAPT (adding the word<STRONG> P</STRONG>ort) would be more precise, but - we will follow the widespread usage.</P> -<P>A gateway doing NAT rewrites the headers of packets it is forwarding, - changing one or more of:</P> -<UL> -<LI>source address</LI> -<LI>source port</LI> -<LI>destination address</LI> -<LI>destination port</LI> -</UL> -<P>On Linux 2.4, NAT services are provided by the<A href="http://netfilter.samba.org"> - netfilter(8)</A> firewall code. There are several<A href="http://netfilter.samba.org/documentation/index.html#HOWTO"> - Netfilter HowTos</A> including one on NAT.</P> -<P>For older versions of Linux, this was referred to as "IP masquerade" - and different tools were used. See this<A href="http://www.e-infomax.com/ipmasq/"> - resource page</A>.</P> -<P>Putting an IPsec gateway behind a NAT gateway is not recommended. See - our<A href="#NAT"> firewalls document</A>.</P> -<H3><A NAME="17_3_1">NAT to non-routable addresses</A></H3> -<P>The most common application of NAT uses private<A href="#non-routable"> - non-routable</A> addresses.</P> -<P>Often a home or small office network will have:</P> -<UL> -<LI>one connection to the Internet</LI> -<LI>one assigned publicly visible IP address</LI> -<LI>several machines that all need access to the net</LI> -</UL> -<P>Of course this poses a problem since several machines cannot use one - address. The best solution might be to obtain more addresses, but often - this is impractical or uneconomical.</P> -<P>A common solution is to have:</P> -<UL> -<LI><A href="#non-routable">non-routable</A> addresses on the local - network</LI> -<LI>the gateway machine doing NAT</LI> -<LI>all packets going outside the LAN rewritten to have the gateway as - their source address</LI> -</UL> -<P>The client machines are set up with reserved<A href="#non-routable"> - non-routable</A> IP addresses defined in RFC 1918. The masquerading - gateway, the machine with the actual link to the Internet, rewrites - packet headers so that all packets going onto the Internet appear to - come from one IP address, that of its Internet interface. It then gets - all the replies, does some table lookups and more header rewriting, and - delivers the replies to the appropriate client machines.</P> -<P>As far as anyone else on the Internet is concerned, the systems - behind the gateway are completely hidden. Only one machine with one IP - address is visible.</P> -<P>For IPsec on such a gateway, you can entirely ignore the NAT in:</P> -<UL> -<LI><A href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</A></LI> -<LI>firewall rules affecting your Internet-side interface</LI> -</UL> -<P>Those can be set up exactly as they would be if your gateway had no - other systems behind it.</P> -<P>You do, however, have to take account of the NAT in firewall rules - which affect packet forwarding.</P> -<H3><A NAME="17_3_2">NAT to routable addresses</A></H3> -<P>NAT to routable addresses is also possible, but is less common and - may make for rather tricky routing problems. We will not discuss it - here. See the<A href="http://netfilter.samba.org/documentation/index.html#HOWTO"> - Netfilter HowTos</A>.</P> -<HR> -<H1><A name="user.examples">FreeS/WAN script examples</A></H1> - This file is intended to hold a collection of user-written example - scripts or configuration files for use with FreeS/WAN. -<P> So far it has only one entry.</P> -<H2><A name="poltorak">Poltorak's Firewall script</A></H2> -<PRE> -From: Poltorak Serguei <poltorak@dataforce.net> -Subject: [Users] Using FreeS/WAN -Date: Tue, 16 Oct 2001 - -Hello. - -I'm using FreeS/WAN IPsec for half a year. I learned a lot of things about -it and I think it would be interesting for someone to see the result of my -experiments and usage of FreeS/WAN. If you find a mistake in this -file, please e-mail me. And excuse me for my english... I'm learning.. :) - -I'll talk about vary simple configuration: - -addresses prefix = 192.168 - - lan1 sgw1 .0.0/24 (Internet) sgw2 lan2 - .1.0/24---[ .1.1 ; .0.1 ]===================[ .0.10 ; . 2.10 ]---.2.0/24 - - -We need to let lan1 see lan2 across Internet like it is behind sgw1. The -same for lan2. And we need to do IPX bridge for Novel Clients and NDS -synchronization. - -my config: -------------------- ipsec.conf ------------------- -conn lan1-lan2 - type=tunnel - compress=yes - #------------------- - left=192.168.0.1 - leftsubnet=192.168.1.0/24 - #------------------- - right=192.168.0.10 - rightsubnet=192.168.2.0/24 - #------------------- - auth=esp - authby=secret ---------------- end of ipsec.conf ---------------- - -ping .2.x from .1.y (y != 1) -It works?? Fine. Let's continue... - -Why y != 1 ?? Because kernel of sgw1 have 2 IP addresses and it will choose -the first IP (which is used to go to Internet) .0.1 and the packet won't go -through IPsec tunnel :( But if do ping on .1.1 kernel will respond from -that address (.1.1) and the packet will be tunneled. The same problem occurred then -.2.x sends a packet to .1.2 which is down at the moment. What happens? .1.1 -sends ARP requesting .1.2... after 3 tries it send to .2.x an destunreach, -but from his "natural" IP or .0.1 . So the error message won't be delivered! -It's a big problem... - -Resolution... One can manipulate with ipsec0 or ipsec0:0 to solve the -problem (if ipsec0 has .1.1 kernel will send packets correctly), but there -are powerful and elegant iproute2 :) We simply need to change source address -of packet that goes to other secure lan. This is done with - -ip route replace 192.168.2.0/24 via 192.168.0.10 dev ipsec0 src 192.168.1.1 - -Cool!! Now it works!! - -The second step. We want install firewall on sgw1 and sgw2. Encryption of -traffic without security isn't a good idea. I don't use {left|right}firewall, -because I'm running firewall from init scripts. - -We want IPsec data between lan1-lan2, some ICMP errors (destination -unreachable, TTL exceeded, parameter problem and source quench), replying on -pings from both lans and Internet, ipxtunnel data for IPX and of course SSH -between sgw1 and sgw2 and from/to one specified host. - -I'm using ipchains. With iptables there are some changes. - ----------------- rc.firewall --------------------- -#!/bin/sh -# -# Firewall for IPsec lan1-lan2 -# - -IPC=/sbin/ipchains -ANY=0.0.0.0/0 - -# left -SGW1_EXT=192.168.0.1 -SGW1_INT=192.168.1.1 -LAN1=192.168.1.0/24 - -# right -SGW2_EXT=192.168.0.10 -SGW2_INT=192.168.2.10 -LAN2=192.168.2.0/24 - -# SSH from and to this host -SSH_PEER_HOST=_SOME_HOST_ - -# this is for left. exchange these values for right. -MY_EXT=$SGW1_EXT -MY_INT=$SGW1_INT -PEER_EXT=$SGW2_EXT -PEER_INT=$SGW2_INT -INT_IF=eth1 -EXT_IF=eth0 -IPSEC_IF=ipsec0 -MY_LAN=$LAN1 -PEER_LAN=$LAN2 - -$IPC -F -$IPC -P input DENY -$IPC -P forward DENY -$IPC -P output DENY - -# Loopback traffic -$IPC -A input -i lo -j ACCEPT -$IPC -A output -i lo -j ACCEPT - -# for IPsec SGW1-SGW2 -## IKE -$IPC -A input -p udp -s $PEER_EXT 500 -d $MY_EXT 500 -i $EXT_IF -j ACCEPT -$IPC -A output -p udp -s $MY_EXT 500 -d $PEER_EXT 500 -i $EXT_IF -j ACCEPT -## ESP -$IPC -A input -p 50 -s $PEER_EXT -d $MY_EXT -i $EXT_IF -j ACCEPT -### we don't need this line ### $IPC -A output -p 50 -s $MY_EXT -d $PEER_EXT -i $EXT_IF -j ACCEPT -## forward LAN1-LAN2 -$IPC -A forward -s $MY_LAN -d $PEER_LAN -i $IPSEC_IF -j ACCEPT -$IPC -A forward -s $PEER_LAN -d $MY_LAN -i $INT_IF -j ACCEPT -$IPC -A output -s $PEER_LAN -d $MY_LAN -i $INT_IF -j ACCEPT -$IPC -A input -s $PEER_LAN -d $MY_LAN -i $IPSEC_IF -j ACCEPT -$IPC -A input -s $MY_LAN -d $PEER_LAN -i $INT_IF -j ACCEPT -$IPC -A output -s $MY_LAN -d $PEER_LAN -i $IPSEC_IF -j ACCEPT - -# ICMP -# -## Dest unreachable -### from/to Internet -$IPC -A input -p icmp --icmp-type destination-unreachable -s $ANY -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type destination-unreachable -s $MY_EXT -d $ANY -i $EXT_IF -j ACCEPT -### from/to Lan -$IPC -A input -p icmp --icmp-type destination-unreachable -s $ANY -d $MY_INT -i $INT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type destination-unreachable -s $MY_INT -d $ANY -i $INT_IF -j ACCEPT -### from/to Peer Lan -$IPC -A input -p icmp --icmp-type destination-unreachable -s $ANY -d $MY_INT -i $IPSEC_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type destination-unreachable -s $MY_INT -d $ANY -i $IPSEC_IF -j ACCEPT -# -## Source quench -### from/to Internet -$IPC -A input -p icmp --icmp-type source-quench -s $ANY -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type source-quench -s $MY_EXT -d $ANY -i $EXT_IF -j ACCEPT -### from/to Lan -$IPC -A input -p icmp --icmp-type source-quench -s $ANY -d $MY_INT -i $INT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type source-quench -s $MY_INT -d $ANY -i $INT_IF -j ACCEPT -### from/to Peer Lan -$IPC -A input -p icmp --icmp-type source-quench -s $ANY -d $MY_INT -i $IPSEC_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type source-quench -s $MY_INT -d $ANY -i $IPSEC_IF -j ACCEPT -# -## Parameter problem -### from/to Internet -$IPC -A input -p icmp --icmp-type parameter-problem -s $ANY -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type parameter-problem -s $MY_EXT -d $ANY -i $EXT_IF -j ACCEPT -### from/to Lan -$IPC -A input -p icmp --icmp-type parameter-problem -s $ANY -d $MY_INT -i $INT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type parameter-problem -s $MY_INT -d $ANY -i $INT_IF -j ACCEPT -### from/to Peer Lan -$IPC -A input -p icmp --icmp-type parameter-problem -s $ANY -d $MY_INT -i $IPSEC_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type parameter-problem -s $MY_INT -d $ANY -i $IPSEC_IF -j ACCEPT -# -## Time To Live exceeded -### from/to Internet -$IPC -A input -p icmp --icmp-type time-exceeded -s $ANY -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type time-exceeded -s $MY_EXT -d $ANY -i $EXT_IF -j ACCEPT -### to Lan -$IPC -A input -p icmp --icmp-type time-exceeded -s $ANY -d $MY_INT -i $INT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type time-exceeded -s $MY_INT -d $ANY -i $INT_IF -j ACCEPT -### to Peer Lan -$IPC -A input -p icmp --icmp-type time-exceeded -s $ANY -d $MY_INT -i $IPSEC_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type time-exceeded -s $MY_INT -d $ANY -i $IPSEC_IF -j ACCEPT - -# ICMP PINGs -## from Internet -$IPC -A input -p icmp -s $ANY -d $MY_EXT --icmp-type echo-request -i $EXT_IF -j ACCEPT -$IPC -A output -p icmp -s $MY_EXT -d $ANY --icmp-type echo-reply -i $EXT_IF -j ACCEPT -## from LAN -$IPC -A input -p icmp -s $ANY -d $MY_INT --icmp-type echo-request -i $INT_IF -j ACCEPT -$IPC -A output -p icmp -s $MY_INT -d $ANY --icmp-type echo-reply -i $INT_IF -j ACCEPT -## from Peer LAN -$IPC -A input -p icmp -s $ANY -d $MY_INT --icmp-type echo-request -i $IPSEC_IF -j ACCEPT -$IPC -A output -p icmp -s $MY_INT -d $ANY --icmp-type echo-reply -i $IPSEC_IF -j ACCEPT - -# SSH -## from SSH_PEER_HOST -$IPC -A input -p tcp -s $SSH_PEER_HOST -d $MY_EXT 22 -i $EXT_IF -j ACCEPT -$IPC -A output -p tcp \! -y -s $MY_EXT 22 -d $SSH_PEER_HOST -i $EXT_IF -j ACCEPT -## to SSH_PEER_HOST -$IPC -A input -p tcp \! -y -s $SSH_PEER_HOST 22 -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p tcp -s $MY_EXT -d $SSH_PEER_HOST 22 -i $EXT_IF -j ACCEPT -## from PEER -$IPC -A input -p tcp -s $PEER_EXT -d $MY_EXT 22 -i $EXT_IF -j ACCEPT -$IPC -A output -p tcp \! -y -s $MY_EXT 22 -d $PEER_EXT -i $EXT_IF -j ACCEPT -## to PEER -$IPC -A input -p tcp \! -y -s $PEER_EXT 22 -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p tcp -s $MY_EXT -d $PEER_EXT 22 -i $EXT_IF -j ACCEPT - -# ipxtunnel -$IPC -A input -p udp -s $PEER_INT 2005 -d $MY_INT 2005 -i $IPSEC_IF -j ACCEPT -$IPC -A output -p udp -s $MY_INT 2005 -d $PEER_INT 2005 -i $IPSEC_IF -j ACCEPT - ----------------- end of rc.firewall ---------------------- - -To understand this we need to look on this scheme: - - ++-----------------------<----------------------------+ - || ipsec0 | - \/ | - eth0 +--------+ /---------/ yes /---------/ yes +-----------------------+ ------->| INPUT |-->/ ?local? /----->/ ?IPsec? /----->| decrypt decapsulate | - eth1 +--------+ /---------/ /---------/ +-----------------------+ - || no || no - \/ \/ - +----------+ +---------+ +-------+ - | routing | | local | | local | - | decision | | deliver | | send | - +----------+ +---------+ +-------+ - || || - \/ \/ - +---------+ +----------+ - | forward | | routing | - +---------+ | decision | - || +----------+ - || || - ++----------------<-----------------++ - || - \/ - +--------+ eth0 - | OUTPUT | eth1 - +--------+ ipsec0 - || - \/ - /---------/ yes +-----------------------+ - / ?IPsec? /----->| encrypt encapsulate | - /---------/ +-----------------------+ - || no || - || || - || \/ eth0, eth1 - ++-----------------------++--------------> - -This explain how a packet traverse TCP/IP stack in IPsec capable kernel. - -FIX ME, please, if there are any errors - -Test the new firewall now. - - -Now about IPX. I tried 3 programs for tunneling IPX: tipxd, SIB and ipxtunnel - -tipxd didn't send packets.. :( -SIB and ipxtunnel worked fine :) -With ipxtunnel there was a little problem. In sources there are an error. - ---------------------- in main.c ------------------------ -< bytes += p.len; ---- -> bytes += len; --------------------------------------------------------- - -After this FIX everything goes right... - -------------------- /etc/ipxtunnel.conf ---------------- -port 2005 -remote 192.168.101.97 2005 -interface eth1 ---------------- end of /etc/ipxtunnel.conf ------------- - -I use IPX tunnel between .1.1 and .2.10 so we don't need to encrypt nor -authenticate encapsulated IPX packets, it is done with IPsec. - -If you don't wont to use iproute2 to change source IP you need to use SIB -(it is able to bind local address) or establish tunnel between .0.1 and -.0.10 (external IPs, you need to do encryption in the program, but it isn't -strong). - -For now I'm using ipxtunnel. - -I think that's all for the moment. If there are any error, please e-mail me: -poltorak@df.ru . It would be cool if someone puts the scheme of TCP/IP in -kernel and firewall example on FreeS/WAN's manual pages. - -PoltoS -</PRE> -<HR> -<H1><A name="makecheck">How to configure to use "make check"</A></H1> -<H2><A NAME="19_1">What is "make check"</A></H2> -<P> "make check" is a target in the top level makefile. It takes care of - running a number of unit and system tests to confirm that FreeSWAN has - been compiled correctly, and that no new bugs have been introduced.</P> -<P> As FreeSWAN contains both kernel and userspace components, doing - testing of FreeSWAN requires that the kernel be simulated. This is - typically difficult to do as a kernel requires that it be run on bare - hardware. A technology has emerged that makes this simpler. This is<A HREF="http://user-mode-linux.sourceforge.net"> - User Mode Linux</A>.</P> -<P> User-Mode Linux is a way to build a Linux kernel such that it can - run as a process under another Linux (or in the future other) kernel. - Presently, this can only be done for 2.4 guest kernels. The host kernel - can be 2.2 or 2.4.</P> -<P> "make check" expects to be able to build User-Mode Linux kernels - with FreeSWAN included. To do this it needs to have some files - downloaded and extracted prior to running "make check". This is - described in the<A HREF="umltesting.html"> UML testing</A> document.</P> -<P> After having run the example in the UML testing document and - successfully brought up the four machine combination, you are ready to - use "make check"</P> -<H2><A NAME="19_2">Running "make check"</A></H2> -<P> "make check" works by walking the FreeSWAN source tree invoking the - "check" target at each node. At present there are tests defined only - for the <CODE>klips</CODE> directory. These tests will use the UML - infrastructure to test out pieces of the <CODE>klips</CODE> code.</P> -<P> The results of the tests can be recorded. If the environment - variable <CODE>$REGRESSRESULTS</CODE> is non-null, then the results of - each test will be recorded. This can be used as part of a nightly - regression testing system, see<A HREF="nightly.html"> Nightly testing</A> - for more details.</P> -<P> "make check" otherwise prints a minimal amount of output for each - test, and indicates pass/fail status of each test as they are run. - Failed tests do not cause failure of the target in the form of exit - codes.</P> -<H1><A NAME="20">How to write a "make check" test</A></H1> -<H2><A NAME="20_1">Structure of a test</A></H2> -<P> Each test consists of a set of directories under <CODE>testing/</CODE> -. There are directories for <CODE>klips</CODE>, <CODE>pluto</CODE>, <CODE> -packaging</CODE> and <CODE>libraries</CODE>. Each directory has a list - of tests to run is stored in a file called <CODE>TESTLIST</CODE> in - that directory. e.g. <CODE>testing/klips/TESTLIST</CODE>.</P> -<H2 NAME="TESTLIST"><A NAME="20_2">The TESTLIST</A></H2> -<P> This isn't actually a shell script. It just looks like one. Some - tools other than /bin/sh process it. Lines that start with # are - comments.</P> -<PRE> -# test-kind directory-containing-test expectation [PR#] -</PRE> -<P>The first word provides the test type, detailed below.</P> -<P> The second word is the name of the test to run. This the directory - in which the test case is to be found..</P> -<P>The third word may be one of:</P> -<DL> -<DT> blank/good</DT> -<DD>the test is believed to function, report failure</DD> -<DT> bad</DT> -<DD> the test is known to fail, report unexpected success</DD> -<DT> suspended</DT> -<DD> the test should not be run</DD> -</DL> -<P> The fourth word may be a number, which is a PR# if the test is - failing.</P> -<H2><A NAME="20_3">Test kinds</A></H2> - The test types are: -<DL> -<DT>skiptest</DT> -<DD>means run no test.</DD> -<DT>ctltest</DT> -<DD>means run a single system without input/output.</DD> -<DT>klipstest</DT> -<DD>means run a single system with input/output networks</DD> -<DT><A HREF="#umlplutotest">umlplutotest</A></DT> -<DD>means run a pair of systems</DD> -<DT><A HREF="#umlXhost">umlXhost</A></DT> -<DD>run an arbitrary number of systems</DD> -<DT>suntest (TBD)</DT> -<DD>means run a quad of east/west/sunrise/sunset</DD> -<DT>roadtest (TBD)</DT> -<DD>means run a trio of east-sunrise + warrior</DD> -<DT>extrudedtest (TBD)</DT> -<DD>means run a quad of east-sunrise + warriorsouth + park</DD> -<DT>mkinsttest</DT> -<DD>a test of the "make install" machinery.</DD> -<DT>kernel_test_patch</DT> -<DD>a test of the "make kernelpatch" machinery.</DD> -</DL> - Tests marked (TBD) have yet to be fully defined. -<P> Each test directory has a file in it called <CODE>testparams.sh</CODE> -. This file sets a number of environment variables to define the - parameters of the test.</P> -<H2><A NAME="20_4">Common parameters</A></H2> -<DL> -<DT>TESTNAME</DT> -<DD>the name of the test (repeated for checking purposes)</DD> -<DT>TEST_TYPE</DT> -<DD>the type of the test (repeat of type type above)</DD> -<DT>TESTHOST</DT> -<DD>the name of the UML machine to run for the test, typically "east" or - "west"</DD> -<DT>TEST_PURPOSE</DT> -<DD>The purpose of the test is one of: -<DL> -<DT>goal</DT> -<DD>The goal purpose is where a test is defined for code that is not yet - finished. The test indicates when the goals have in fact been reached.</DD> -<DT>regress</DT> -<DD>This is a test to determine that a previously existing bug has been - repaired. This test will initially be created to reproduce the bug in - isolation, and then the bug will be fixed.</DD> -<DT>exploit</DT> -<DD>This is a set of packets/programs that causes a vulnerability to be - exposed. It is a specific variation of the regress option.</DD> -</DL> -</DD> -<DT>TEST_GOAL_ITEM</DT> -<DT></DT> -<DD>in the case of a goal test, this is a reference to the requirements - document</DD> -<DT>TEST_PROB_REPORT</DT> -<DD>in the case of regression test, this the problem report number from - GNATS</DD> -<DT>TEST_EXPLOIT_URL</DT> -<DD>in the case of an exploit, this is a URL referencing the paper - explaining the origin of the test and the origin of exploit software</DD> -<DT>REF_CONSOLE_OUTPUT</DT> -<DD>a file in the test directory that contains the sanitized console - output against which to compare the output of the actual test.</DD> -<DT>REF_CONSOLE_FIXUPS</DT> -<DD>a list of scripts (found in <CODE>klips/test/fixups</CODE>) to apply - to sanitize the console output of the machine under test. These are - typically perl, awk or sed scripts that remove things in the kernel - output that change each time the test is run and/or compiled.</DD> -<DT>INIT_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode prior to starting the tests. This file will usually - set up any eroute's and SADB entries that are required for the test.</P> -<P>Lines beginning with # are skipped. Blank lines are skipped. - Otherwise, a shell prompted is waited for each time (consisting of <CODE> -\n#</CODE>) and then the command is sent. Note that the prompt is waited - for before the command and not after, so completion of the last command - in the script is not required. This is often used to invoke a program - to monitor the system, e.g. <CODE>ipsec pf_key</CODE>.</P> -</DD> -<DT>RUN_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode, before the packets are sent. On single machine tests, - this script doesn't provide any more power than INIT_SCRIPT, but is - implemented for consistency's sake.</P> -</DD> -<DT>FINAL_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode after the final packet is sent. Similar to - INIT_SCRIPT, above. If not specified, then the single command "halt" is - sent. If specified, then the script should end with a halt command to - nicely shutdown the UML.</P> -</DD> -<DT>CONSOLEDIFFDEBUG</DT> -<DD>If set to "true" then the series of console fixups (see - REF_CONSOLE_FIXUPS) will be output after it is constructed. (It should - be set to "false", or unset otherwise)</DD> -<DT>NETJIGDEBUG</DT> -<DD>If set to "true" then the series of console fixups (see - REF_CONSOLE_FIXUPS) will be output after it is constructed. (It should - be set to "false", or unset otherwise)</DD> -<DT>NETJIGTESTDEBUG</DT> -<DD> If set to "netjig", then the results of talking to the <CODE> -uml_netjig</CODE> will be printed to stderr during the test. In - addition, the jig will be invoked with --debug, which causes it to log - its process ID, and wait 60 seconds before continuing. This can be used - if you are trying to debug the <CODE>uml_netjig</CODE> program itself.</DD> -<DT>HOSTTESTDEBUG</DT> -<DD> If set to "hosttest", then the results of taling to the consoles of - the UMLs will be printed to stderr during the test.</DD> -<DT>NETJIGWAITUSER</DT> -<DD> If set to "waituser", then the scripts will wait forever for user - input before they shut the tests down. Use this is if you are debugging - through the kernel.</DD> -<DT>PACKETRATE</DT> -<DD> A number, in miliseconds (default is 500ms) at which packets will - be replayed by the netjig.</DD> -</DL> -<H2><A NAME="20_5">KLIPStest paramaters</A></H2> -<P> The klipstest function starts a program (<CODE> -testing/utils/uml_netjig/uml_netjig</CODE>) to setup a bunch of I/O - sockets (that simulate network interfaces). It then exports the - references to these sockets to the environment and invokes (using - system()) a given script. It waits for the script to finish.</P> - -<!-- <IMG SRC="single_netjig.png" ALT="block diagram of uml_netjig"> --> -<P> The script invoked (<CODE>testing/utils/host-test.tcl</CODE>) is a - TCL<A HREF="http://expect.nist.gov/"> expect</A> script that arranges - to start the UML and configure it appropriately for the test. The - configuration is done with the script given above for<VAR> INIT_SCRIPT</VAR> -. The TCL script then forks, leaves the UML in the background and exits. - uml_netjig continues. It then starts listening to the simulated network - answering ARPs and inserting packets as appropriate.</P> -<P> The klipstest function invokes <CODE>uml_netjig</CODE> with - arguments to capture output from network interface(s) and insert - packets as appropriate:</P> -<DL> -<DT>PUB_INPUT</DT> -<DD>a<A HREF="http://www.tcpdump.org/"> pcap</A> file to feed in on the - public (encrypted) interface. (typically, eth1)</DD> -<DT>PRIV_INPUT</DT> -<DD>a pcap file to feed in on the private (plain-text) interface - (typically, eth0).</DD> -<DT>REF_PUB_OUTPUT</DT> -<DD>a text file containing tcpdump output. Packets on the public (eth1) - interface are captured to a<A HREF="http://www.tcpdump.org/"> pcap</A> - file by <CODE>uml_netjig</CODE>. The klipstest function then uses - tcpdump on the file to produce text output, which is compared to the - file given.</DD> -<DT>REF_PUB_FILTER</DT> -<DD>a program that will filter the TCPDUMP output to do further - processing. Defaults to "cat".</DD> -<DT>REF_PRIV_OUTPUT</DT> -<DD>a text file containing tcpdump output. Packets on the private (eth0) - interface are captured and compared after conversion by tcpdump, as - with<VAR> REFPUBOUTPUT</VAR>.</DD> -<DT>REF_PRIV_FILTER</DT> -<DD>a program that will filter the TCPDUMP output to do further - processing. Defaults to "cat".</DD> -<DT>EXITONEMPTY</DT> -<DD>a flag for <CODE>uml_netjig</CODE>. It should contain - "--exitonempty" of uml_netjig should exit when all of the input (<VAR> -PUBINPUT</VAR>,<VAR>PRIVINPUT</VAR>) packets have been injected.</DD> -<DT>ARPREPLY</DT> -<DD>a flag for <CODE>uml_netjig</CODE>. It should contain "--arpreply" - if <CODE>uml_netjig</CODE> should reply to ARP requests. One will - typically set this to avoid having to fudge the ARP cache manually.</DD> -<DT>TCPDUMPFLAGS</DT> -<DD>a set of flags for the tcpdump used when converting captured output. - Typical values will include "-n" to turn off DNS, and often "-E" to set - the decryption key (tcpdump 3.7.1 and higher only) for ESP packets. The - "-t" flag (turn off timestamps) is provided automatically</DD> -<DT>NETJIG_EXTRA</DT> -<DD>additional comments to be sent to the netjig. This may arrange to - record or create additional networks, or may toggle options.</DD> -</DL> -<H2><A NAME="20_6">mkinsttest paramaters</A></H2> -<P> The basic concept of the <CODE>mkinsttest</CODE> test type is that - it performs a "make install" to a temporary $DESTDIR. The resulting - tree can then be examined to determine if it was done properly. The - files can be uninstalled to determine if the file list was correct, or - the contents of files can be examined more precisely.</P> -<DL> -<DT>INSTALL_FLAGS</DT> -<DD>If set, then an install will be done. This provides the set of flags - to provide for the install. The target to be used (usually "install") - must be among the flags.</DD> -<DT>POSTINSTALL_SCRIPT</DT> -<DD>If set, a script to run after initial "make install". Two arguments - are provided: an absolute path to the root of the FreeSWAN src tree, - and an absolute path to the temporary installation area.</DD> -<DT>INSTALL2_FLAGS</DT> -<DD>If set, a second install will be done using these flags. Similarly - to INSTALL_FLAGS, the target must be among the flags.</DD> -<DT>UNINSTALL_FLAGS</DT> -<DD>If set, an uninstall will be done using these flags. Similarly to - INSTALL_FLAGS, the target (usually "uninstall") must be among the - flags.</DD> -<DT>REF_FIND_f_l_OUTPUT</DT> -<DD>If set, a <CODE>find $ROOT ( -type f -or -type -l )</CODE> will be - done to get a list of a real files and symlinks. The resulting file - will be compared to the file listed by this option.</DD> -<DT>REF_FILE_CONTENTS</DT> -<DD>If set, it should point to a file containing records for the form: -<PRE> - -<!--VARIABLE--> -reffile</(null)> -<!--VARIABLE--> -samplefile</(null)> -</PRE> - one record per line. A diff between the provided reference file, and - the sample file (located in the temporary installation root) will be - done for each record.</DD> -</DL> -<H2><A NAME="20_7">rpm_build_install_test paramaters</A></H2> -<P> The <CODE>rpm_build_install_test</CODE> type is to verify that the - proper packing list is produced by "make rpm", and that the mechanisms - for building the kernel modules produce consistent results.</P> -<DL> -<DT>RPM_KERNEL_SOURCE</DT> -<DD>Point to an extracted copy of the RedHat kernel source code. - Variables from the environment may be used.</DD> -<DT>REF_RPM_CONTENTS</DT> -<DD>This is a file containing one record per line. Each record consists - of a RPM name (may contain wildcards) and a filename to compare the - contents to. The RPM will be located and a file list will be produced - with rpm2cpio.</DD> -</DL> -<H2><A NAME="20_8">libtest paramaters</A></H2> -<P> The libtest test is for testing library routines. The library file - is expected to provided an <CODE>#ifdef</CODE> by the name of<VAR> - library</VAR> -<!--CODE_MAIN</CODE--> -. The libtest type invokes the C compiler to compile this - file, links it against <CODE>libfreeswan.a</CODE> (to resolve any other - dependancies) and runs the test with the <CODE>-r</CODE> argument to - invoke a regression test.</(null)></P> -<P>The library test case is expected to do a self-test, exiting with - status code 0 if everything is okay, and with non-zero otherwise. A - core dump (exit code greater than 128) is noted specifically.</P> -<P> Unlike other tests, there are no subdirectories required, or other - parameters to set.</P> -<H2 NAME="umlplutotest"><A NAME="20_9">umlplutotest paramaters</A></H2> -<P> The umlplutotest function starts a pair of user mode line processes. - This is a 2-host version of umlXhost. The "EAST" and "WEST" slots are - defined.</P> -<H2 NAME="umlXhost"><A NAME="20_10">umlXhost parameters</A></H2> -<P> The umlXtest function starts an arbitrary number of user mode line - processes.</P> - -<!-- <IMG SRC="single_netjig.png" ALT="block diagram of uml_netjig"> --> -<P> The script invoked (<CODE>testing/utils/Xhost-test.tcl</CODE>) is a - TCL<A HREF="http://expect.nist.gov/"> expect</A> script that arranges - to start each UML and configure it appropriately for the test. It then - starts listening (using uml_netjig) to the simulated network answering - ARPs and inserting packets as appropriate.</P> -<P> umlXtest has a series of slots, each of which should be filled by a - host. The list of slots is controlled by the variable, XHOST_LIST. This - variable should be set to a space seperated list of slots. The former - umlplutotest is now implemented as a variation of the umlXhost test, - with XHOST_LIST="EAST WEST".</P> -<P> For each host slot that is defined, a series of variables should be - filled in, defining what configuration scripts to use for that host.</P> -<P> The following are used to control the console input and output to - the system. Where the string ${host} is present, the host slot should - be filled in. I.e. for the two host system with XHOST_LIST="EAST WEST", - then the variables: EAST_INIT_SCRIPT and WEST_INIT_SCRIPT will exist.</P> -<DL> -<DT>${host}HOST</DT> -<DD>The name of the UML host which will fill this slot</DD> -<DT>${host}_INIT_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode prior to starting the tests. This file will usually - set up any eroute's and SADB entries that are required for the test. - Similar to INIT_SCRIPT, above.</P> -</DD> -<DT>${host}_RUN_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode, before the packets are sent. This set of commands is - run after all of the virtual machines are initialized. I.e. after - EAST_INIT_SCRIPT<B> AND</B> WEST_INIT_SCRIPT. This script can therefore - do things that require that all machines are properly configured.</P> -</DD> -<DT>${host}_RUN2_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode, after the packets are sent. This set of commands is - run before any of the virtual machines have been shut down. (I.e. - before EAST_FINAL_SCRIPT<B> AND</B> WEST_FINAL_SCRIPT.) This script can - therefore catch post-activity status reports.</P> -</DD> -<DT>${host}_FINAL_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode after the final packet is sent. Similar to - INIT_SCRIPT, above. If not specified, then the single command "halt" is - sent. Note that when this script is run, the other virtual machines may - already have been killed. If specified, then the script should end with - a halt command to nicely shutdown the UML.</P> -</DD> -<DT>REF_${host}_CONSOLE_OUTPUT</DT> -<DD>Similar to REF_CONSOLE_OUTPUT, above.</DD> -</DL> -<P>Some additional flags apply to all hosts:</P> -<DL> -<DT>REF_CONSOLE_FIXUPS</DT> -<DD>a list of scripts (found in <CODE>klips/test/fixups</CODE>) to apply - to sanitize the console output of the machine under test. These are - typically perl, awk or sed scripts that remove things in the kernel - output that change each time the test is run and/or compiled.</DD> -</DL> -<P> In addition to input to the console, the networks may have input fed - to them:</P> -<DL> -<DT>EAST_INPUT/WEST_INPUT</DT> -<DD>a<A HREF="http://www.tcpdump.org/"> pcap</A> file to feed in on the - private network side of each network. The "EAST" and "WEST" here refer - to the networks, not the hosts.</DD> -<DT>REF_PUB_FILTER</DT> -<DD>a program that will filter the TCPDUMP output to do further - processing. Defaults to "cat".</DD> -<DT>REF_EAST_FILTER/REF_WEST_FILTER</DT> -<DD>a program that will filter the TCPDUMP output to do further - processing. Defaults to "cat".</DD> -< -<DT>TCPDUMPFLAGS</DT> -<DD>a set of flags for the tcpdump used when converting captured output. - Typical values will include "-n" to turn off DNS, and often "-E" to set - the decryption key (tcpdump 3.7.1 and higher only) for ESP packets. The - "-t" flag (turn off timestamps) is provided automatically</DD> -<DT>REF_EAST_OUTPUT/REF_WEST_OUTPUT</DT> -<DD>a text file containing tcpdump output. Packets on the private (eth0) - interface are captured and compared after conversion by tcpdump, as - with<VAR> REF_PUB_OUTPUT</VAR>.</DD> -<P> There are two additional environment variables that may be set on - the command line:</P> -<DL> -<DT> NETJIGVERBOSE=verbose export NETJIGVERBOSE</DT> -<DD> If set, then the test output will be "chatty", and let you know - what commands it is running, and as packets are sent. Without it set, - the output is limited to success/failure messages.</DD> -<DT> NETJIGTESTDEBUG=netjig export NETJIGTESTDEBUG</DT> -<DD> This will enable debugging of the communication with uml_netjig, - and turn on debugging in this utility. This does not imply - NETJIGVERBOSE.</DD> -</DL> -<DT> HOSTTESTDEBUG=hosttest export HOSTTESTDEBUG</DT> -<DD> This will show all interactions with the user-mode-linux consoles</DD> -</DL> -<H2 NAME="kernelpatch"><A NAME="20_11">kernel_patch_test paramaters</A></H2> -<P> The kernel_patch_test function takes some kernel source, copies it - with lndir, and then applies the patch as produced by "make - kernelpatch".</P> -<P> The following are used to control the input and output to the - system:</P> -<DL> -<DT>KERNEL_NAME</DT> -<DD>the kernel name, typically something like "linus" or "rh"</DD> -<DT>KERNEL_VERSION</DT> -<DD>the kernel version number, as in "2.2" or "2.4".</DD> -<DT>KERNEL_${KERNEL_NAME}${KERNEL_VERSION}_SRC</DT> -<DD>This variable should set in the environment, probably in - ~/freeswan-regress-env.sh. Examples of this variables would be - KERNEL_LINUS2_0_SRC or KERNEL_RH7_3_SRC. This variable should point to - an extracted copy of the kernel source in question.</DD> -<DT>REF_PATCH_OUTPUT</DT> -<DD>a copy of the patch output to compare against</DD> -<DT>KERNEL_PATCH_LEAVE_SOURCE</DT> -<DD>If set to a non-empty string, then the patched kernel source is not - removed at the end of the test. This will typically be set in the - environment while debugging.</DD> -</DL> -<H2 NAME="modtest"><A NAME="20_12">module_compile paramaters</A></H2> -<P> The module_compile test attempts to build the KLIPS module against a - given set of kernel source. This is also done by the RPM tests, but in - a very specific manner.</P> -<P> There are two variations of this test - one where the kernel either - doesn't need to be configured, or is already done, and tests were there - is a local configuration file.</P> -<P> Where the kernel doesn't need to be configured, the kernel source - that is found is simply used. It may be a RedHat-style kernel, where - one can cause it to configure itself via rhconfig.h-style definitions. - Or, it may just be a kernel tree that has been configured.</P> -<P> If the variable KERNEL_CONFIG_FILE is set, then a new directory is - created for the kernel source. It is populated with lndir(1). The - referenced file is then copied in as .config, and "make oldconfig" is - used to configure the kernel. This resulting kernel is then used as the - reference source.</P> -<P> In all cases, the kernel source is found the same was for the - kernelpatch test, i.e. via KERNEL_VERSION/KERNEL_NAME and - KERNEL_${KERNEL_NAME}${KERNEL_VERSION}_SRC.</P> -<P> Once there is kernel source, the module is compiled using the - top-level "make module" target.</P> -<P> The test is considered successful if an executable is found in - OUTPUT/module/ipsec.o at the end of the test.</P> -<DL> -<DT>KERNEL_NAME</DT> -<DD>the kernel name, typically something like "linus" or "rh"</DD> -<DT>KERNEL_VERSION</DT> -<DD>the kernel version number, as in "2.2" or "2.4".</DD> -<DT>KERNEL_${KERNEL_NAME}${KERNEL_VERSION}_SRC</DT> -<DD>This variable should set in the environment, probably in - ~/freeswan-regress-env.sh. Examples of this variables would be - KERNEL_LINUS2_0_SRC or KERNEL_RH7_3_SRC. This variable should point to - an extracted copy of the kernel source in question.</DD> -<DT>KERNEL_CONFIG_FILE</DT> -<DD>The configuration file for the kernel.</DD> -<DT>KERNEL_PATCH_LEAVE_SOURCE</DT> -<DD>If set to a non-empty string, then the configured kernel source is - not removed at the end of the test. This will typically be set in the - environment while debugging.</DD> -<DT>MODULE_DEF_INCLUDE</DT> -<DD>The include file that will be used to configure the KLIPS module, - and possibly the kernel source.</DD> -</DL> -<H1><A NAME="21">Current pitfalls</A></H1> -<DL> -<DT> "tcpdump dissector" not available.</DT> -<DD> This is a non-fatal warning. If uml_netjig is invoked with the -t - option, then it will attempt to use tcpdump's dissector to decode each - packet that it processes. The dissector is presently not available, so - this option it normally turned off at compile time. The dissector - library will be released with tcpdump version 4.0.</DD> -</DL> -<HR> -<H1><A name="umltesting">User-Mode-Linux Testing guide</A></H1> -<P> User mode linux is a way to compile a linux kernel such that it can - run as a process in another linux system (potentially as a *BSD or - Windows process later). See<A HREF="http://user-mode-linux.sourceforge.net/"> - http://user-mode-linux.sourceforge.net/</A></P> -<P> UML is a good platform for testing and experimenting with FreeS/WAN. - It allows several network nodes to be simulated on a single machine. - Creating, configuring, installing, monitoring, and controling these - nodes is generally easier and easier to script with UML than real - hardware.</P> -<P> You'll need about 500Mb of disk space for a full - sunrise-east-west-sunset setup. You can possibly get this down by 130Mb - if you remove the sunrise/sunset kernel build. If you just want to run, - then you can even remove the east/west kernel build.</P> -<P> Nothing need be done as super user. In a couple of steps, we note - where super user is required to install commands in system-wide - directories, but ~/bin could be used instead. UML seems to use a - system-wide /tmp/uml directory so different users may interfere with - one another. Later UMLs use ~/.uml instead, so multiple users running - UML tests should not be a problem, but note that a single user running - the UML tests will only be able run one set. Further, UMLs sometimes - get stuck and hang around. These "zombies" (most will actually be in - the "T" state in the process table) will interfere with subsequent - tests.</P> -<H2><A NAME="22_1">Preliminary Notes on BIND</A></H2> -<P> As of 2003/3/1, the Light-Weight Resolver is used by pluto. This - requires that BIND9 be running. It also requires that BIND9 development - libraries be present in the build environment. The DNSSEC code is only - truly functional in BIND9 snapshots. The library code could be 9.2.2, - we believe. We are using BIND9 20021115 snapshot code from<A HREF="ftp://ftp.isc.org/isc/bind9/snapshots"> - ftp://ftp.isc.org/isc/bind9/snapshots</A>.</P> -<P> FreeS/WAN may well require a newer BIND than is on your system. Many - distributions have moved to BIND9.2.2 recently due to a security - advisory. BIND is five components.</P> -<OL> -<LI> named</LI> -<LI> dnssec-*</LI> -<LI> client side resolver libraries</LI> -<LI> client side utility libraries I thought there were lib and named - parts to dnsssec...</LI> -<LI> dynamic DNS update utilities</LI> -</OL> -<P> The only piece that we need for *building* is #4. That's the only - part that has to be on the build host. What is the difference between - resolver and util libs? If you want to edit - testing/baseconfigs/all/etc/bind, you'll need a snapshot version. The - resolver library contains the resolver. FreeS/WAN has its own copy of - that in lib/liblwres.</P> -<H2><A NAME="22_2">Steps to Install UML for FreeS/WAN</A></H2> -<OL> -<LI> Get the following files: -<OL type="a"> -<LI> from<A HREF="http://www.sandelman.ottawa.on.ca/freeswan/uml/"> - http://www.sandelman.ottawa.on.ca/freeswan/uml/</A> - umlfreeroot-15.1.tar.gz (or highest numbered one). This is a debian - potato root file system. You can use this even on a Redhat host, as it - has the newer GLIBC2.2 libraries as well. -<!-- If you are using - Redhat 7.2 or newer as your development machine, you can create the - image from your installation media. See <A HREF="uml-rhroot.html">Building a RedHat root"></A>. - A future document will explain how to build this from .DEB files as well. ---> - -<!-- -<LI> umlfreesharemini.tar.gz (or umlfreeshareall.tar.gz). - If you are a Debian potato user, you don't need it you can use your - native /usr/share. -</UL> ---> -</LI> -<LI> From<A HREF="ftp://ftp.xs4all.nl/pub/crypto/freeswan/"> - ftp://ftp.xs4all.nl/pub/crypto/freeswan/</A> a snapshot or release - (1.92 or better)</LI> -<LI> From a<A HREF="http://www.kernel.org/mirrors/"> - http://www.kernel.org mirror</A>, the virgin 2.4.19 kernel. Please - realize that we have defaults in our tree for kernel configuration. We - try to track the latest UML kernels. If you use a newer kernel, you may - have faults in the kernel build process. You can see what the latest - that is being regularly tested by visiting<A HREF="http://bugs.freeswan.org:81/regress/HEAD/lastgood/freeswan-regress-env.sh"> - freeswan-regress-env.sh</A>.</LI> -<LI> -<!-- Note: this step is refered to as "step 1d" below. --> - Get<A HREF="http://ftp.nl.linux.org/uml/"> - http://ftp.nl.linux.org/uml/</A> uml-patch-2.4.19-47.bz2 or the one - associated with your kernel. As of 2003/03/05, uml-patch-2.4.19-47.bz2 - works for us.<STRONG> More recent versions of the patch have not been - tested by us.</STRONG></LI> -<LI> You'll probably want to visit<A HREF="http://user-mode-linux.sourceforge.net"> - http://user-mode-linux.sourceforge.net</A> and get the UML utilities. - These are not needed for the build or interactive use (but - recommended). They are necessary for the regression testing procedures - used by "make check". We currently use uml_utilities_20020212.tar.bz2.</LI> -<LI> You need tcpdump version 3.7.1 or better. This is newer than the - version included in most LINUX distributions. You can check the version - of an installed tcpdump with the --version flag. If you need a newer - tcpdump fetch both tcpdump and libpcap source tar files from<A HREF="http://www.tcpdump.org/"> - http://www.tcpdump.org/</A> or a mirror.</LI> -</OL> -</LI> -<LI> Pick a suitable place, and extract the following files: -<OL type="a"> -<LI> -<!-- Note: this step is refered to as "step 2a" later. --> - 2.4.19 kernel. For instance: -<PRE> - <CODE> cd /c2/kernel - tar xzvf ../download/pub/linux/kernel/v2.4/linux-2.4.19.tar.gz -</CODE> -</PRE> -</LI> -<LI> extract the umlfreeroot file -<!-- (unless you <A HREF="uml-rhroot.html">built your own from RPMs</A>) --> - -<PRE> - <CODE> mkdir -p /c2/user-mode-linux/basic-root - cd /c2/user-mode-linux/basic-root - tar xzvf ../download/umlfreeroot-15.1.tar.gz -</CODE> -</PRE> -</LI> -<LI> FreeSWAN itself (or checkout "all" from CVS) -<PRE> - <CODE> mkdir -p /c2/freeswan/sandbox - cd /c2/freeswan/sandbox - tar xzvf ../download/snapshot.tar.gz -</CODE> -</PRE> -</LI> -</OL> -</LI> -<LI> If you need to build a newer tcpdump: -<UL> -<LI> Make sure you have OpenSSL installed -- it is needed for - cryptographic routines.</LI> -<LI> Unpack libpcap and tcpdump source in parallel directories (the - tcpdump build procedures look for libpcap next door).</LI> -<LI> Change directory into the libpcap source directory and then build - the library: -<PRE> - <CODE> ./configure - make -</CODE> -</PRE> -</LI> -<LI> Change into the tcpdump source directory, build tcpdump, and - install it. -<PRE> - <CODE> ./configure - make - # Need to be superuser to install in system directories. - # Installing in ~/bin would be an alternative. - su -c "make install" -</CODE> -</PRE> -</LI> -</UL> -</LI> -<LI> If you need the uml utilities, unpack them somewhere then build and - install them: -<PRE> - <CODE> cd tools - make all - # Need to be superuser to install in system directories. - # Installing in ~/bin would be an alternative. - su -c "make install BIN_DIR=/usr/local/bin" -</CODE> -</PRE> -</LI> -<LI> set up the configuration file -<UL> -<LI> <CODE>cd /c2/freeswan/sandbox/freeswan-1.97/testing/utils</CODE></LI> -<LI> copy umlsetup-sample.sh to ../../umlsetup.sh: <CODE> cp - umlsetup-sample.sh ../../umlsetup.sh</CODE></LI> -<LI> open up ../../umlsetup.sh in your favorite editor.</LI> -<LI> change POOLSPACE= to point to the place with at least 500Mb of - disk. Best if it is on the same partition as the "umlfreeroot" - extraction, as it will attempt to use hard links if possible to save - disk space.</LI> -<LI> Set TESTINGROOT if you intend to run the script outside of the - sandbox/snapshot/release directory. Otherwise, it will configure - itself.</LI> -<LI> KERNPOOL should point to the directory with your 2.4.19 kernel - tree. This tree should be unconfigured! This is the directory you used - in step 2a.</LI> -<LI> UMLPATCH should point at the bz2 file you downloaded at 1d. If - using a kernel that already includes the patch, set this to /dev/null.</LI> -<LI> FREESWANDIR should point at the directory where you unpacked the - snapshot/release. Include the "freeswan-snap2001sep16b" or whatever in - it. If you are running from CVS, then you point at the directory where - top, klips, etc. are. The script will fix up the directory so that it - can be used.</LI> -<LI> BASICROOT should be set to the directory used in 2b, or to the - directory that you created with RPMs.</LI> -<LI> SHAREDIR should be set to the directory used in 2c, to /usr/share - for Debian potato users, or to $BASICROOT/usr/share.</LI> -</UL> -</LI> -<LI> -<PRE> <CODE>cd $TESTINGROOT/utils -sh make-uml.sh -</CODE></PRE> - It will grind for awhile. If there are errors it will bail. If so, run - it under "script" and send the output to bugs@lists.freeswan.org.</LI> -<LI> You will have a bunch of stuff under $POOLSPACE. Open four xterms: -<PRE> <CODE> for i in sunrise sunset east west - do - xterm -name $i -title $i -e $POOLSPACE/$i/start.sh done -</CODE></PRE> -</LI> -<LI> Login as root. Password is "root" (Note, these virtual machines are - networked together, but are not configured to talk to the rest of the - world.)</LI> -<LI> verify that pluto started on east/west, run "ipsec look"</LI> -<LI> login to sunrise. run "ping sunset"</LI> -<LI> login to west. run "tcpdump -p -i eth1 -n" (tcpdump must be version - 3.7.1 or newer)</LI> -<LI> Closing a console xterm will shut down that UML.</LI> -<LI> You can "make check", if you want to. It is run from - /c2/freeswan/sandbox/freeswan-1.97.</LI> -</OL> -<H1><A NAME="23">Debugging the kernel with GDB</A></H1> -<P> With User-Mode-Linux, you can debug the kernel using GDB. See -<!--HREF="http://user-mode-linux.sourceforge.net/debugging.html"--> - - http://user-mode-linux.sourceforge.net/debugging.html.</(null)></P> -<P> Typically, one will want to address a test case for a failing - situation. Running GDB from Emacs, or from other front ends is - possible. First start GDB.</P> -<P> Tell it to open the UMLPOOL/swan/linux program.</P> -<P> Note the PID of GDB:</P> -<PRE> -marajade-[projects/freeswan/mgmt/planning] mcr 1029 %ps ax | grep gdb - 1659 pts/9 SN 0:00 /usr/bin/gdb -fullname -cd /mara4/freeswan/kernpatch/UMLPOOL/swan/ linux -</PRE> -<P> Set the following in the environment:</P> -<PRE> -UML_east_OPT="debug gdb-pid=1659" -</PRE> -<P> Then start the user-mode-linux in the test scheme you wish:</P> -<PRE> -marajade-[kernpatch/testing/klips/east-icmp-02] mcr 1220 %../../utils/runme.sh -</PRE> - The user-mode-linux will stop on boot, giving you a chance to attach to - the process: -<PRE> -(gdb) file linux -Reading symbols from linux...done. -(gdb) attach 1 -Attaching to program: /mara4/freeswan/kernpatch/UMLPOOL/swan/linux, process 1 -0xa0118bc1 in kill () at hostfs_kern.c:770 -</PRE> -<P> At this point, break points should be created as appropriate.</P> -<H2><A NAME="23_1">Other notes about debugging</A></H2> -<P> If you are running a standard test, after all the packets are sent, - the UML will be shutdown. This can cause problems, because the UML may - get terminated while you are debugging.</P> -<P> The environment variable <CODE>NETJIGWAITUSER</CODE> can be set to - "waituser". If so, then the testing system will prompt before exiting - the test.</P> -<H1><A NAME="24">User-Mode-Linux mysteries</A></H1> -<UL> -<LI> running more than one UML of the same name (e.g. "west") can cause - problems.</LI> -<LI> running more than one UML from the same root file system is not a - good idea.</LI> -<LI> all this means that running "make check" twice on the same machine - is probably not a good idea.</LI> -<LI> occationally, UMLs will get stuck. This can happen like: -<!--BLOCK--> - 15134 ? T - 0:00 /spare/hugh/uml/uml2.4.18-sept5/umlbuild/east/linux (east) - [/bin/sh] 15138 ? T 0:00 - /spare/hugh/uml/uml2.4.18-sept5/umlbuild/east/linux (east) [halt]</(null)> - these will need to be killed. Note that they are in "T"racing mode.</LI> -<LI> UMLs can also hang, and will report "Tracing myself and I can't get - out". This is a bug in UML. There are ways to find out what is going on - and report this to the UML people, but we don't know the magic right - now.</LI> -</UL> -<H1><A NAME="25">Getting more info from uml_netjig</A></H1> -<P> uml_netjig can be compiled with a built-in tcpdump. This uses - not-yet-released code from<A HREF="http://www.tcpdump.org/"> - www.tcpdump.org</A>. Please see the instructions in <CODE> -testing/utils/uml_netjig/Makefile</CODE>.</P> -<HR> -<H1><A name="politics">History and politics of cryptography</A></H1> -<P>Cryptography has a long and interesting history, and has been the - subject of considerable political controversy.</P> -<H2><A name="intro.politics">Introduction</A></H2> -<H3><A NAME="26_1_1">History</A></H3> -<P>The classic book on the history of cryptography is David Kahn's<A href="#Kahn"> - The Codebreakers</A>. It traces codes and codebreaking from ancient - Egypt to the 20th century.</P> -<P>Diffie and Landau<A href="#diffie"> Privacy on the Line: The Politics - of Wiretapping and Encryption</A> covers the history from the First - World War to the 1990s, with an emphasis on the US.</P> -<H4><A NAME="26_1_1_1">World War II</A></H4> -<P>During the Second World War, the British "Ultra" project achieved one - of the greatest intelligence triumphs in the history of warfare, - breaking many Axis codes. One major target was the Enigma cipher - machine, a German device whose users were convinced it was unbreakable. - The American "Magic" project had some similar triumphs against Japanese - codes.</P> -<P>There are many books on this period. See our bibliography for - several. Two I particularly like are:</P> -<UL> -<LI>Andrew Hodges has done a superb<A href="http://www.turing.org.uk/book/"> - biography</A> of Alan Turing, a key player among the Ultra - codebreakers. Turing was also an important computer pioneer. The terms<A -href="http://www.abelard.org/turpap/turpap.htm"> Turing test</A> and<A href="http://plato.stanford.edu/entries/turing-machine/"> - Turing machine</A> are named for him, as is the<A href="http://www.acm.org"> - ACM</A>'s highest technical<A href="http://www.acm.org/awards/taward.html"> - award</A>.</LI> -<LI>Neal Stephenson's<A href="#neal"> Cryptonomicon</A> is a novel with - cryptography central to the plot. Parts of it take place during WW II, - other parts today.</LI> -</UL> -<P>Bletchley Park, where much of the Ultra work was done, now has a - museum and a<A href="http://www.bletchleypark.org.uk/"> web site</A>.</P> -<P>The Ultra work introduced three major innovations.</P> -<UL> -<LI>The first break of Enigma was achieved by Polish Intelligence in - 1931. Until then most code-breakers had been linguists, but a different - approach was needed to break machine ciphers. Polish Intelligence - recruited bright young mathematicians to crack the "unbreakable" - Enigma. When war came in 1939, the Poles told their allies about this, - putting Britain on the road to Ultra. The British also adopted a - mathematical approach.</LI> -<LI>Machines were extensively used in the attacks. First the Polish - "Bombe" for attacking Enigma, then British versions of it, then - machines such as Collosus for attacking other codes. By the end of the - war, some of these machines were beginning to closely resemble digital - computers. After the war, a team at Manchester University, several old - Ultra hands included, built one of the world's first actual - general-purpose digital computers.</LI> -<LI>Ultra made codebreaking a large-scale enterprise, producing - intelligence on an industrial scale. This was not a "black chamber", - not a hidden room in some obscure government building with a small crew - of code-breakers. The whole operation -- from wholesale interception of - enemy communications by stations around the world, through large-scale - code-breaking and analysis of the decrypted material (with an enormous - set of files for cross-referencing), to delivery of intelligence to - field commanders -- was huge, and very carefully managed.</LI> -</UL> -<P>So by the end of the war, Allied code-breakers were expert at - large-scale mechanised code-breaking. The payoffs were enormous.</P> -<H4><A name="postwar">Postwar and Cold War</A></H4> -<P>The wartime innovations were enthusiastically adopted by post-war and - Cold War signals intelligence agencies. Presumably many nations now - have some agency capable of sophisticated attacks on communications - security, and quite a few engage in such activity on a large scale.</P> -<P>America's<A href="#NSA"> NSA</A>, for example, is said to be both the - world's largest employer of mathematicians and the world's largest - purchaser of computer equipment. Such claims may be somewhat - exaggerated, but beyond doubt the NSA -- and similar agencies in other - countries -- have some excellent mathematicians, lots of powerful - computers, sophisticated software, and the organisation and funding to - apply them on a large scale. Details of the NSA budget are secret, but - there are some published<A href="http://www.fas.org/irp/nsa/nsabudget.html"> - estimates</A>.</P> -<P>Changes in the world's communications systems since WW II have - provided these agencies with new targets. Cracking the codes used on an - enemy's military or diplomatic communications has been common practice - for centuries. Extensive use of radio in war made large-scale attacks - such as Ultra possible. Modern communications make it possible to go - far beyond that. Consider listening in on cell phones, or intercepting - electronic mail, or tapping into the huge volumes of data on new media - such as fiber optics or satellite links. None of these targets existed - in 1950. All of them can be attacked today, and almost certainly are - being attacked.</P> -<P>The Ultra story was not made public until the 1970s. Much of the - recent history of codes and code-breaking has not been made public, and - some of it may never be. Two important books are:</P> -<UL> -<LI>Bamford's<A href="#puzzle"> The Puzzle Palace</A>, a history of the - NSA</LI> -<LI>Hager's<A href="http://www.fas.org/irp/eprint/sp/index.html"> Secret - Power</A>, about the<A href="http://sg.yahoo.com/government/intelligence/echelon_network/"> - Echelon</A> system -- the US, UK, Canada, Australia and New Zealand - co-operating to monitor much of the world's communications.</LI> -</UL> -<P>Note that these books cover only part of what is actually going on, - and then only the activities of nations open and democratic enough that - (some of) what they are doing can be discovered. A full picture, - including:</P> -<UL> -<LI>actions of the English-speaking democracies not covered in those - books</LI> -<LI>actions of other more-or-less sane governments</LI> -<LI>the activities of various more-or-less insane governments</LI> -<LI>possibilities for unauthorized action by government employees</LI> -<LI>possible actions by large non-government organisations: - corporations, criminals, or conspiracies</LI> -</UL> -<P>might be really frightening.</P> -<H4><A name="recent">Recent history -- the crypto wars</A></H4> -<P>Until quite recently, cryptography was primarily a concern of - governments, especially of the military, of spies, and of diplomats. - Much of it was extremely secret.</P> -<P>In recent years, that has changed a great deal. With computers and - networking becoming ubiquitous, cryptography is now important to almost - everyone. Among the developments since the 1970s:</P> -<UL> -<LI>The US gov't established the Data Encryption Standard,<A href="#DES"> - DES</A>, a<A href="#block"> block cipher</A> for cryptographic - protection of unclassfied documents.</LI> -<LI>DES also became widely used in industry, especially regulated - industries such as banking.</LI> -<LI>Other nations produced their own standards, such as<A href="glossary.html#GOST"> - GOST</A> in the Soviet Union.</LI> -<LI><A href="#public">Public key</A> cryptography was invented by Diffie - and Hellman.</LI> -<LI>Academic conferences such as<A href="http://www-cse.ucsd.edu/users/mihir/crypto2k.html"> - Crypto</A> and<A href="http://www.esat.kuleuven.ac.be/cosic/eurocrypt2000/"> - Eurocrypt</A> began.</LI> -<LI>Several companies began offerring cryptographic products:<A href="#RSAco"> - RSA</A>,<A href="#PGPI"> PGP</A>, the many vendors with<A href="#PKI"> - PKI</A> products, ...</LI> -<LI>Cryptography appeared in other products: operating systems, word - processors, ...</LI> -<LI>Network protocols based on crypto were developed:<A href="#ssh"> SSH</A> -,<A href="#SSL"> SSL</A>,<A href="#IPSEC"> IPsec</A>, ...</LI> -<LI>Crytography came into widespread use to secure bank cards, - terminals, ...</LI> -<LI>The US government replaced<A href="#DES"> DES</A> with the much - stronger Advanced Encryption Standard,<A href="#AES"> AES</A></LI> -</UL> -<P>This has led to a complex ongoing battle between various mainly - government groups wanting to control the spread of crypto and various - others, notably the computer industry and the<A href="http://online.offshore.com.ai/security/"> - cypherpunk</A> crypto advocates, wanting to encourage widespread use.</P> -<P>Steven Levy has written a fine history of much of this, called<A href="#crypto"> - Crypto: How the Code rebels Beat the Government -- Saving Privacy in - the Digital Age</A>.</P> -<P>The FreeS/WAN project is to a large extent an outgrowth of cypherpunk - ideas. Our reasons for doing the project can be seen in these quotes - from the<A href="http://www.eff.org/pub/Privacy/Crypto_misc/cypherpunk.manifesto"> - Cypherpunk Manifesto</A>:</P> -<BLOCKQUOTE> Privacy is necessary for an open society in the electronic - age. ... -<P>We cannot expect governments, corporations, or other large, faceless - organizations to grant us privacy out of their beneficence. It is to - their advantage to speak of us, and we should expect that they will - speak. ...</P> -<P>We must defend our own privacy if we expect to have any. ...</P> -<P>Cypherpunks write code. We know that someone has to write software to - defend privacy, and since we can't get privacy unless we all do, we're - going to write it. We publish our code so that our fellow Cypherpunks - may practice and play with it. Our code is free for all to use, - worldwide. We don't much care if you don't approve of the software we - write. We know that software can't be destroyed and that a widely - dispersed system can't be shut down.</P> -<P>Cypherpunks deplore regulations on cryptography, for encryption is - fundamentally a private act. ...</P> -<P>For privacy to be widespread it must be part of a social contract. - People must come and together deploy these systems for the common good. - ...</P> -</BLOCKQUOTE> -<P>To quote project leader John Gilmore:</P> -<BLOCKQUOTE> We are literally in a race between our ability to build and - deploy technology, and their ability to build and deploy laws and - treaties. Neither side is likely to back down or wise up until it has - definitively lost the race.</BLOCKQUOTE> -<P>If FreeS/WAN reaches its goal of making<A href="#opp.intro"> - opportunistic encryption</A> widespread so that secure communication - can become the default for a large part of the net, we will have struck - a major blow.</P> -<H3><A name="intro.poli">Politics</A></H3> -<P>The political problem is that nearly all governments want to monitor - their enemies' communications, and some want to monitor their citizens. - They may be very interested in protecting some of their own - communications, and often some types of business communication, but not - in having everyone able to communicate securely. They therefore attempt - to restrict availability of strong cryptography as much as possible.</P> -<P>Things various governments have tried or are trying include:</P> -<UL> -<LI>Echelon, a monitor-the-world project of the US, UK, NZ, Australian - and Canadian<A href="#SIGINT"> signals intelligence</A> agencies. See - this<A href="http://sg.yahoo.com/government/intelligence/echelon_network/"> - collection</A> of links and this<A href="http://www.zdnet.com/zdnn/stories/news/0,4586,2640682,00.html"> - story</A> on the French Parliament's reaction.</LI> -<LI>Others governments may well have their own Echelon-like projects. To - quote the Dutch Minister of Defense, as reported in a German<A href="http://www.heise.de/tp/english/inhalt/te/4729/1.html"> - magazine</A>:<BLOCKQUOTE> The government believes not only the - governments associated with Echelon are able to intercept communication - systems, but that it is an activity of the investigative authorities - and intelligence services of many countries with governments of - different political signature.</BLOCKQUOTE> Even if they have nothing - on the scale of Echelon, most intelligence agencies and police forces - certainly have some interception capability.</LI> -<LI><A href="#NSA">NSA</A> tapping of submarine communication cables, - described in<A href="http://www.zdnet.com/zdnn/stories/news/0,4586,2764372,00.html"> - this article</A></LI> -<LI>A proposal for international co-operation on<A href="http://www.heise.de/tp/english/special/enfo/4306/1.html"> - Internet surveillance</A>.</LI> -<LI>Alleged<A href="http://cryptome.org/nsa-sabotage.htm"> sabotage</A> - of security products by the<A href="#NSA"> NSA</A> (the US signals - intelligence agency).</LI> -<LI>The German armed forces and some government departments will stop - using American software for fear of NSA "back doors", according to this<A -href="http://www.theregister.co.uk/content/4/17679.html"> news story</A> -.</LI> -<LI>The British Regulation of Investigatory Powers bill. See this<A href="http://www.fipr.org/rip/index.html"> - web page.</A> and perhaps this<A href="http://ars.userfriendly.org/cartoons/?id=20000806&mode=classic"> - cartoon</A>.</LI> -<LI>A Russian<A href="http://www.eff.org/pub/Privacy/Foreign_and_local/Russia/russian_crypto_ban_english.edict"> - ban</A> on cryptography</LI> -<LI>Chinese<A href="http://www.eff.org/pub/Misc/Publications/Declan_McCullagh/www/global/china"> - controls</A> on net use.</LI> -<LI>The FBI's carnivore system for covert searches of email. See this<A href="http://www.zdnet.com/zdnn/stories/news/0,4586,2601502,00.html"> - news coverage</A> and this<A href="http://www.crypto.com/papers/carnivore-risks.html"> - risk assessment</A>. The government had an external review of some - aspects of this system done. See this<A href="http://www.crypto.com/papers/carnivore_report_comments.html"> - analysis</A> of that review. Possible defenses against Carnivore - include: -<UL> -<LI><A href="#PGP">PGP</A> for end-to-end mail encryption</LI> -<LI><A href="http://www.home.aone.net.au/qualcomm/">secure sendmail</A> - for server-to-server encryption</LI> -<LI>IPsec encryption on the underlying IP network</LI> -</UL> -</LI> -<LI>export laws restricting strong cryptography as a munition. See<A href="#exlaw"> - discussion</A> below.</LI> -<LI>various attempts to convince people that fundamentally flawed - cryptography, such as encryption with a<A href="#escrow"> back door</A> - for government access to data or with<A href="#shortkeys"> inadequate - key lengths</A>, was adequate for their needs.</LI> -</UL> -<P>Of course governments are by no means the only threat to privacy and - security on the net. Other threats include:</P> -<UL> -<LI>industrial espionage, as for example in this<A href="http://www.zdnet.com/zdnn/stories/news/0,4586,2626931,00.html"> - news story</A></LI> -<LI>attacks by organised criminals, as in this<A href="http://www.sans.org/newlook/alerts/NTE-bank.htm"> - large-scale attack</A></LI> -<LI>collection of personal data by various companies. -<UL> -<LI>for example, consider the various corporate winners of Privacy - International's<A href="http://www.privacyinternational.org/bigbrother/"> - Big Brother Awards</A>.</LI> -<LI><A href="http://www.zeroknowledge.com">Zero Knowledge</A> sell tools - to defend against this</LI> -</UL> -</LI> -<LI>individuals may also be a threat in a variety of ways and for a - variety of reasons</LI> -<LI>in particular, an individual with access to government or industry - data collections could do considerable damage using that data in - unauthorized ways.</LI> -</UL> -<P>One<A href="http://www.zdnet.com/zdnn/stories/news/0,4586,2640674,00.html"> - study</A> enumerates threats and possible responses for small and - medium businesses. VPNs are a key part of the suggested strategy.</P> -<P>We consider privacy a human right. See the UN's<A href="http://www.un.org/Overview/rights.html"> - Universal Declaration of Human Rights</A>, article twelve:</P> -<BLOCKQUOTE> No one shall be subjected to arbitrary interference with - his privacy, family, home or correspondence, nor to attacks upon his - honor and reputation. Everyone has the right to the protection of the - law against such interference or attacks.</BLOCKQUOTE> -<P>Our objective is to help make privacy possible on the Internet using - cryptography strong enough not even those well-funded government - agencies are likely to break it. If we can do that, the chances of - anyone else breaking it are negliible.</P> -<H3><A NAME="26_1_3">Links</A></H3> -<P>Many groups are working in different ways to defend privacy on the - net and elsewhere. Please consider contributing to one or more of these - groups:</P> -<UL> -<LI>the EFF's<A href="http://www.eff.org/crypto/"> Privacy Now!</A> - campaign</LI> -<LI>the<A href="http://www.gilc.org"> Global Internet Liberty Campaign</A> -</LI> -<LI><A href="http://www.cpsr.org/program/privacy/privacy.html">Computer - Professionals for Social Responsibility</A></LI> -</UL> -<P>For more on these issues see:</P> -<UL> -<LI>Steven Levy (Newsweek's chief technology writer and author of the - classic "Hackers") new book<A href="#crypto"> Crypto: How the Code - Rebels Beat the Government--Saving Privacy in the Digital Age</A></LI> -<LI>Simson Garfinkel (Boston Globe columnist and author of books on<A href="#PGP"> - PGP</A> and<A href="#practical"> Unix Security</A>) book<A href="#Garfinkel"> - Database Nation: the death of privacy in the 21st century</A></LI> -</UL> -<P>There are several collections of<A href="#quotes"> crypto quotes</A> - on the net.</P> -<P>See also the<A href="biblio.html"> bibliography</A> and our list of<A href="#policy"> - web references</A> on cryptography law and policy.</P> -<H3><A NAME="26_1_4">Outline of this section</A></H3> -<P>The remainder of this section includes two pieces of writing by our - project leader</P> -<UL> -<LI>his<A href="#gilmore"> rationale</A> for starting this</LI> -<LI>another<A href="#policestate"> discussion</A> of project goals</LI> -</UL> -<P>and discussions of:</P> -<UL> -<LI><A href="#desnotsecure">why we do not use DES</A></LI> -<LI><A href="#exlaw">cryptography export laws</A></LI> -<LI>why<A href="#escrow"> government access to keys</A> is not a good - idea</LI> -<LI>the myth that<A href="#shortkeys"> short keys</A> are adequate for - some security requirements</LI> -</UL> -<P>and a section on<A href="#press"> press coverage of FreeS/WAN</A>.</P> -<H2><A name="leader">From our project leader</A></H2> -<P>FreeS/WAN project founder John Gilmore wrote a web page about why we - are doing this. The version below is slightly edited, to fit this - format and to update some links. For a version without these edits, see - his<A href="http://www.toad.com/gnu/"> home page</A>.</P> -<CENTER> -<H3><A name="gilmore">Swan: Securing the Internet against Wiretapping</A> -</H3> -</CENTER> -<P>My project for 1996 was to<B> secure 5% of the Internet traffic - against passive wiretapping</B>. It didn't happen in 1996, so I'm still - working on it in 1997, 1998, and 1999! If we get 5% in 1999 or 2000, we - can secure 20% the next year, against both active and passive attacks; - and 80% the following year. Soon the whole Internet will be private and - secure. The project is called S/WAN or S/Wan or Swan for Secure Wide - Area Network; since it's free software, we call it FreeSwan to - distinguish it from various commercial implementations.<A href="http://www.rsa.com/rsa/SWAN/"> - RSA</A> came up with the term "S/WAN". Our main web site is at<A href="http://www.freeswan.org/"> - http://www.freeswan.org/</A>. Want to help?</P> -<P>The idea is to deploy PC-based boxes that will sit between your local - area network and the Internet (near your firewall or router) which - opportunistically encrypt your Internet packets. Whenever you talk to a - machine (like a Web site) that doesn't support encryption, your traffic - goes out "in the clear" as usual. Whenever you connect to a machine - that does support this kind of encryption, this box automatically - encrypts all your packets, and decrypts the ones that come in. In - effect, each packet gets put into an "envelope" on one side of the net, - and removed from the envelope when it reaches its destination. This - works for all kinds of Internet traffic, including Web access, Telnet, - FTP, email, IRC, Usenet, etc.</P> -<P>The encryption boxes are standard PC's that use freely available - Linux software that you can download over the Internet or install from - a cheap CDROM.</P> -<P>This wasn't just my idea; lots of people have been working on it for - years. The encryption protocols for these boxes are called<A href="#IPSEC"> - IPSEC (IP Security)</A>. They have been developed by the<A href="http://www.ietf.cnri.reston.va.us/html.charters/ipsec-charter.html"> - IP Security Working Group</A> of the<A href="http://www.ietf.org/"> - Internet Engineering Task Force</A>, and will be a standard part of the - next major version of the Internet protocols (<A href="http://playground.sun.com/pub/ipng/html/ipng-main.html"> -IPv6</A>). For today's (IP version 4) Internet, they are an option.</P> -<P>The<A href="http://www.iab.org/iab"> Internet Architecture Board</A> - and<A href="http://www.ietf.org/"> Internet Engineering Steering Group</A> - have taken a<A href="iab-iesg.stmt"> strong stand</A> that the Internet - should use powerful encryption to provide security and privacy. I think - these protocols are the best chance to do that, because they can be - deployed very easily, without changing your hardware or software or - retraining your users. They offer the best security we know how to - build, using the Triple-DES, RSA, and Diffie-Hellman algorithms.</P> -<P>This "opportunistic encryption box" offers the "fax effect". As each - person installs one for their own use, it becomes more valuable for - their neighbors to install one too, because there's one more person to - use it with. The software automatically notices each newly installed - box, and doesn't require a network administrator to reconfigure it. - Instead of "virtual private networks" we have a "REAL private network"; - we add privacy to the real network instead of layering a - manually-maintained virtual network on top of an insecure Internet.</P> -<H4><A NAME="26_2_1_1">Deployment of IPSEC</A></H4> -<P>The US government would like to control the deployment of IP Security - with its<A href="#exlaw"> crypto export laws</A>. This isn't a problem - for my effort, because the cryptographic work is happening outside the - United States. A foreign philanthropist, and others, have donated the - resources required to add these protocols to the Linux operating - system.<A href="http://www.linux.org/"> Linux</A> is a complete, freely - available operating system for IBM PC's and several kinds of - workstation, which is compatible with Unix. It was written by Linus - Torvalds, and is still maintained by a talented team of expert - programmers working all over the world and coordinating over the - Internet. Linux is distributed under the<A href="#GPL"> GNU Public - License</A>, which gives everyone the right to copy it, improve it, - give it to their friends, sell it commercially, or do just about - anything else with it, without paying anyone for the privilege.</P> -<P>Organizations that want to secure their network will be able to put - two Ethernet cards into an IBM PC, install Linux on it from a $30 CDROM - or by downloading it over the net, and plug it in between their - Ethernet and their Internet link or firewall. That's all they'll have - to do to encrypt their Internet traffic everywhere outside their own - local area network.</P> -<P>Travelers will be able to run Linux on their laptops, to secure their - connection back to their home network (and to everywhere else that they - connect to, such as customer sites). Anyone who runs Linux on a - standalone PC will also be able to secure their network connections, - without changing their application software or how they operate their - computer from day to day.</P> -<P>There will also be numerous commercially available firewalls that use - this technology.<A href="http://www.rsa.com/"> RSA Data Security</A> is - coordinating the<A href="http://www.rsa.com/rsa/SWAN"> S/Wan (Secure - Wide Area Network)</A> project among more than a dozen vendors who use - these protocols. There's a<A href="http://www.rsa.com/rsa/SWAN/swan_test.htm"> - compatability chart</A> that shows which vendors have tested their - boxes against which other vendors to guarantee interoperatility.</P> -<P>Eventually it will also move into the operating systems and - networking protocol stacks of major vendors. This will probably take - longer, because those vendors will have to figure out what they want to - do about the export controls.</P> -<H4><A NAME="26_2_1_2">Current status</A></H4> -<P>My initial goal of securing 5% of the net by Christmas '96 was not - met. It was an ambitious goal, and inspired me and others to work hard, - but was ultimately too ambitious. The protocols were in an early stage - of development, and needed a lot more protocol design before they could - be implemented. As of April 1999, we have released version 1.0 of the - software (<A href="ftp://ftp.xs4all.nl/freeswan/freeswan-1.0.tar.gz"> -freeswan-1.0.tar.gz</A>), which is suitable for setting up Virtual - Private Networks using shared secrets for authentication. It does not - yet do opportunistic encryption, or use DNSSEC for authentication; - those features are coming in a future release.</P> -<DL> -<DT>Protocols</DT> -<DD>The low-level encrypted packet formats are defined. The system for - publishing keys and providing secure domain name service is defined. - The IP Security working group has settled on an NSA-sponsored protocol - for key agreement (called ISAKMP/Oakley), but it is still being worked - on, as the protocol and its documentation is too complex and - incomplete. There are prototype implementations of ISAKMP. The protocol - is not yet defined to enable opportunistic encryption or the use of - DNSSEC keys.</DD> -<DT>Linux Implementation</DT> -<DD>The Linux implementation has reached its first major release and is - ready for production use in manually-configured networks, using Linux - kernel version 2.0.36.</DD> -<DT>Domain Name System Security</DT> -<DD>There is now a release of BIND 8.2 that includes most DNS Security - features. -<P>The first prototype implementation of Domain Name System Security was - funded by<A href="#DARPA"> DARPA</A> as part of their<A href="http://www.darpa.mil/ito/research/is/index.html"> - Information Survivability program</A>.<A href="http://www.tis.com"> - Trusted Information Systems</A> wrote a modified version of<A href="http://www.isc.org/bind.html"> - BIND</A>, the widely-used Berkeley implementation of the Domain Name - System.</P> -<P>TIS, ISC, and I merged the prototype into the standard version of - BIND. The first production version that supports KEY and SIG records is<B> - bind-4.9.5</B>. This or any later version of BIND will do for - publishing keys. It is available from the<A href="http://www.isc.org/bind.html"> - Internet Software Consortium</A>. This version of BIND is not - export-controlled since it does not contain any cryptography. Later - releases starting with BIND 8.2 include cryptography for authenticating - DNS records, which is also exportable. Better documentation is needed.</P> -</DD> -</DL> -<H4><A NAME="26_2_1_3">Why?</A></H4> -<P>Because I can. I have made enough money from several successful - startup companies, that for a while I don't have to work to support - myself. I spend my energies and money creating the kind of world that - I'd like to live in and that I'd like my (future) kids to live in. - Keeping and improving on the civil rights we have in the United States, - as we move more of our lives into cyberspace, is a particular goal of - mine.</P> -<H4><A NAME="26_2_1_4">What You Can Do</A></H4> -<DL> -<DT>Install the latest BIND at your site.</DT> -<DD>You won't be able to publish any keys for your domain, until you - have upgraded your copy of BIND. The thing you really need from it is - the new version of<I> named</I>, the Name Daemon, which knows about the - new KEY and SIG record types. So, download it from the<A href="http://www.isc.org/bind.html"> - Internet Software Consortium</A> and install it on your name server - machine (or get your system administrator, or Internet Service - Provider, to install it). Both your primary DNS site and all of your - secondary DNS sites will need the new release before you will be able - to publish your keys. You can tell which sites this is by running the - Unix command "dig MYDOMAIN ns" and seeing which sites are mentioned in - your NS (name server) records.</DD> -<DT>Set up a Linux system and run a 2.0.x kernel on it</DT> -<DD>Get a machine running Linux (say the 5.2 release from<A href="http://www.redhat.com"> - Red Hat</A>). Give the machine two Ethernet cards.</DD> -<DT>Install the Linux IPSEC (Freeswan) software</DT> -<DD>If you're an experienced sysadmin or Linux hacker, install the - freeswan-1.0 release, or any later release or snapshot. These releases - do NOT provide automated "opportunistic" operation; they must be - manually configured for each site you wish to encrypt with.</DD> -<DT>Get on the linux-ipsec mailing list</DT> -<DD>The discussion forum for people working on the project, and testing - the code and documentation, is: linux-ipsec@clinet.fi. To join this - mailing list, send email to<A href="mailto:linux-ipsec-REQUEST@clinet.fi"> - linux-ipsec-REQUEST@clinet.fi</A> containing a line of text that says - "subscribe linux-ipsec". (You can later get off the mailing list the - same way -- just send "unsubscribe linux-ipsec").</DD> -<P></P> -<DT>Check back at this web page every once in a while</DT> -<DD>I update this page periodically, and there may be new information in - it that you haven't seen. My intent is to send email to the mailing - list when I update the page in any significant way, so subscribing to - the list is an alternative.</DD> -</DL> -<P>Would you like to help? I can use people who are willing to write - documentation, install early releases for testing, write cryptographic - code outside the United States, sell pre-packaged software or systems - including this technology, and teach classes for network administrators - who want to install this technology. To offer to help, send me email at - gnu@toad.com. Tell me what country you live in and what your - citizenship is (it matters due to the export control laws; personally I - don't care). Include a copy of your resume and the URL of your home - page. Describe what you'd like to do for the project, and what you're - uniquely qualified for. Mention what other volunteer projects you've - been involved in (and how they worked out). Helping out will require - that you be able to commit to doing particular things, meet your - commitments, and be responsive by email. Volunteer projects just don't - work without those things.</P> -<H4><A NAME="26_2_1_5">Related projects</A></H4> -<DL> -<DT>IPSEC for NetBSD</DT> -<DD>This prototype implementation of the IP Security protocols is for - another free operating system.<A href="ftp://ftp.funet.fi/pub/unix/security/net/ip/BSDipsec.tar.gz"> - Download BSDipsec.tar.gz</A>.</DD> -<DT>IPSEC for<A href="http://www.openbsd.org"> OpenBSD</A></DT> -<DD>This prototype implementation of the IP Security protocols is for - yet another free operating system. It is directly integrated into the - OS release, since the OS is maintained in Canada, which has freedom of - speech in software.</DD> -</DL> -<H3><A name="policestate">Stopping wholesale monitoring</A></H3> -<P>From a message project leader John Gilmore posted to the mailing - list:</P> -<PRE>John Denker wrote: - -> Indeed there are several ways in which the documentation overstates the -> scope of what this project does -- starting with the name -> FreeS/WAN. There's a big difference between having an encrypted IP tunnel -> versus having a Secure Wide-Area Network. This software does a fine job of -> the former, which is necessary but not sufficient for the latter. - -The goal of the project is to make it very hard to tap your wide area -communications. The current system provides very good protection -against passive attacks (wiretapping and those big antenna farms). -Active attacks, which involve the intruder sending packets to your -system (like packets that break into sendmail and give them a root -shell :-) are much harder to guard against. Active attacks that -involve sending people (breaking into your house and replacing parts -of your computer with ones that transmit what you're doing) are also -much harder to guard against. Though we are putting effort into -protecting against active attacks, it's a much bigger job than merely -providing strong encryption. It involves general computer security, -and general physical security, which are two very expensive problems -for even a site to solve, let alone to build into a whole society. - -The societal benefit of building an infrastructure that protects -well against passive attacks is that it makes it much harder to do -undetected bulk monitoring of the population. It's a defense against -police-states, not against policemen. - -Policemen can put in the effort required to actively attack sites that -they have strong suspicions about. But police states won't be able to -build systems that automatically monitor everyone's communications. -Either they will be able to monitor only a small subset of the -populace (by targeting those who screwed up their passive security), -or their monitoring activities will be detectable by those monitored -(active attacks leave packet traces or footprints), which can then be -addressed through the press and through political means if they become -too widespread. - -FreeS/WAN does not protect very well against traffic analysis, which -is a kind of widespread police-state style monitoring that still -reveals significant information (who's talking to who) without -revealing the contents of what was said. Defenses against traffic -analysis are an open research problem. Zero Knowledge Systems is -actively deploying a system designed to thwart it, designed by Ian -Goldberg. The jury is out on whether it actually works; a lot more -experience with it will be needed.</PRE> -<P>Notes on things mentioned in that message:</P> -<UL> -<LI>Denker is a co-author of a<A href="#applied"> paper</A> on a large - FreeS/WAN application.</LI> -<LI>Information on Zero Knowledge is on their<A href="http://www.zks.net/"> - web site</A>. Their Freedom product, designed to provide untracable - pseudonyms for use on the net, is no longer marketed.</LI> -<LI>Another section of our documentation discusses ways to<A href="#traffic.resist"> - resist traffic analysis</A>.</LI> -</UL> -<H2><A name="weak">Government promotion of weak crypto</A></H2> -<P>Various groups, especially governments and especially the US - government, have a long history of advocating various forms of bogus - security.</P> -<P>We regard bogus security as extremely dangerous. If users are - deceived into relying on bogus security, then they may be exposed to - large risks. They would be better off having no security and knowing - it. At least then they would be careful about what they said.</P> -<P><STRONG>Avoiding bogus security is a key design criterion for - everything we do in FreeS/WAN</STRONG>. The most conspicuous example is - our refusal to support<A href="#desnotsecure"> single DES</A>. Other - IPsec "features" which we do not implement are discussed in our<A href="#dropped"> - compatibility</A> document.</P> -<H3><A name="escrow">Escrowed encryption</A></H3> -<P>Various governments have made persistent attempts to encourage or - mandate "escrowed encrytion", also called "key recovery", or GAK for - "government access to keys". The idea is that cryptographic keys be - held by some third party and turned over to law enforcement or security - agencies under some conditions.</P> -<PRE> Mary had a little key - she kept it in escrow, - and every thing that Mary said, - the feds were sure to know.</PRE> -<P>A<A href="#quotes"> crypto quotes</A> page attributes this to<A href="http://www.scramdisk.clara.net/"> - Sam Simpson</A>.</P> -<P>There is an excellent paper available on<A href="http://www.cdt.org/crypto/risks98/"> - Risks of Escrowed Encryption</A>, from a group of cryptographic - luminaries which included our project leader.</P> -<P>Like any unnecessary complication, GAK tends to weaken security of - any design it infects. For example:</P> -<UL> -<LI>Matt Blaze found a fatal flaw in the US government's Clipper chip - shortly after design information became public. See his paper "Protocol - Failure in the Escrowed Encryption Standard" on his<A href="http://www.crypto.com/papers/"> - papers</A> page.</LI> -<LI>a rather<A href="http://www.pgp.com/other/advisories/adk.asp"> nasty - bug</A> was found in the "additional decryption keys" "feature" of some - releases of<A href="#PGP"> PGP</A></LI> -</UL> -<P>FreeS/WAN does not support escrowed encryption, and never will.</P> -<H3><A name="shortkeys">Limited key lengths</A></H3> -<P>Various governments, and some vendors, have also made persistent - attempts to convince people that:</P> -<UL> -<LI>weak systems are sufficient for some data</LI> -<LI>strong cryptography should be reserved for cases where the extra - overheads are justified</LI> -</UL> -<P><STRONG>This is utter nonsense</STRONG>.</P> -<P>Weak systems touted include:</P> -<UL> -<LI>the ludicrously weak (deliberately crippled) 40-bit ciphers that - until recently were all various<A href="#exlaw"> export laws</A> - allowed</LI> -<LI>56-bit single DES, discussed<A href="#desnotsecure"> below</A></LI> -<LI>64-bit symmetric ciphers and 512-bit RSA, the maximums for - unrestricted export under various current laws</LI> -</UL> -<P>The notion that choice of ciphers or keysize should be determined by - a trade-off between security requirements and overheads is pure - bafflegab.</P> -<UL> -<LI>For most<A href="#symmetric"> symmetric ciphers</A>, it is simply a - lie. Any block cipher has some natural maximum keysize inherent in the - design -- 128 bits for<A href="#IDEA"> IDEA</A> or<A href="#CAST128"> - CAST-128</A>, 256 for Serpent or Twofish, 448 for<A href="#Blowfish"> - Blowfish</A> and 2048 for<A href="#RC4"> RC4</A>. Using a key size - smaller than that limit gives<EM> exactly zero</EM> savings in - overhead. The crippled 40-bit or 64-bit version of the cipher provides<EM> - no advantage whatsoever</EM>.</LI> -<LI><A href="#AES">AES</A> uses 10 rounds with 128-bit keys, 12 rounds - for 192-bit and 14 rounds for 256-bit, so there actually is a small - difference in overhead, but not enough to matter in most applications.</LI> -<LI>For<A href="#3DES"> triple DES</A> there is a grain of truth in the - argument. 3DES is indeed three times slower than single DES. However, - the solution is not to use the insecure single DES, but to pick a - faster secure cipher.<A href="#CAST128"> CAST-128</A>,<A href="#Blowfish"> - Blowfish</A> and the<A href="#AES"> AES candidate</A> ciphers are are - all considerably faster in software than DES (let alone 3DES!), and - apparently secure.</LI> -<LI>For<A href="#public"> public key</A> techniques, there are extra - overheads for larger keys, but they generally do not affect overall - performance significantly. Practical public key applications are - usually<A href="#hybrid"> hybrid</A> systems in which the bulk of the - work is done by a symmetric cipher. The effect of increasing the cost - of the public key operations is typically negligible because the public - key operations use only a tiny fraction of total resources. -<P>For example, suppose public key operations use use 1% of the time in - a hybrid system and you triple the cost of public key operations. The - cost of symmetric cipher operations is unchanged at 99% of the original - total cost, so the overall effect is a jump from 99 + 1 = 100 to 99 + 3 - = 102, a 2% rise in system cost.</P> -</LI> -</UL> -<P>In short,<STRONG> there has never been any technical reason to use - inadequate ciphers</STRONG>. The only reason there has ever been for - anyone to use such ciphers is that government agencies want weak - ciphers used so that they can crack them. The alleged savings are - simply propaganda.</P> -<PRE> Mary had a little key (It's all she could export), - and all the email that she sent was opened at the Fort.</PRE> -<P>A<A href="#quotes"> crypto quotes</A> page attributes this to<A href="http://theory.lcs.mit.edu:80/~rivest/"> - Ron Rivest</A>. NSA headquarters is at Fort Meade, Maryland.</P> -<P>Our policy in FreeS/WAN is to use only cryptographic components with - adequate keylength and no known weaknesses.</P> -<UL> -<LI>We do not implement single DES because it is clearly<A href="#desnotsecure"> - insecure</A>, so implemeting it would violate our policy of avoiding - bogus security. Our default cipher is<A href="#3DES"> 3DES</A></LI> -<LI>Similarly, we do not implement the 768-bit Group 1 for<A href="#DH"> - Diffie-Hellman</A> key negotiation. We provide only the 1024-bit Group - 2 and 1536-bit Group 5.</LI> -</UL> -<P>Detailed discussion of which IPsec features we implement or omit is - in out<A href="compat.html"> compatibility document</A>.</P> -<P>These decisions imply that we cannot fully conform to the IPsec RFCs, - since those have DES as the only required cipher and Group 1 as the - only required DH group. (In our view, the standards were subverted into - offerring bogus security.) Fortunately, we can still interoperate with - most other IPsec implementations since nearly all implementers provide - at least 3DES and Group 2 as well.</P> -<P>We hope that eventually the RFCs will catch up with our (and others') - current practice and reject dubious components. Some of our team and a - number of others are working on this in<A href="#ietf"> IETF</A> - working groups.</P> -<H4><A NAME="26_3_2_1">Some real trade-offs</A></H4> -<P>Of course, making systems secure does involve costs, and trade-offs - can be made between cost and security. However, the real trade-offs - have nothing to do with using weaker ciphers.</P> -<P>There can be substantial hardware and software costs. There are often - substantial training costs, both to train administrators and to - increase user awareness of security issues and procedures. There are - almost always substantial staff or contracting costs.</P> -<P>Security takes staff time for planning, implementation, testing and - auditing. Some of the issues are subtle; you need good (hence often - expensive) people for this. You also need people to monitor your - systems and respond to problems. The best safe ever built is insecure - if an attacker can work on it for days without anyone noticing. Any - computer is insecure if the administrator is "too busy" to check the - logs.</P> -<P>Moreover, someone in your organisation (or on contract to it) needs - to spend considerable time keeping up with new developments. EvilDoers<EM> - will</EM> know about new attacks shortly after they are found. You need - to know about them before your systems are attacked. If your vendor - provides a patch, you need to apply it. If the vendor does nothing, you - need to complain or start looking for another vendor.</P> -<P>For a fairly awful example, see this<A href="http://www.sans.org/newlook/alerts/NTE-bank.htm"> - report</A>. In that case over a million credit card numbers were taken - from e-commerce sites, using security flaws in Windows NT servers. - Microsoft had long since released patches for most or all of the flaws, - but the site administrators had not applied them.</P> -<P>At an absolute minimum, you must do something about such issues<EM> - before</EM> an exploitation tool is posted to the net for downloading - by dozens of "script kiddies". Such a tool might appear at any time - from the announcement of the security hole to several months later. - Once it appears, anyone with a browser and an attitude can break any - system whose administrators have done nothing about the flaw.</P> -<P>Compared to those costs, cipher overheads are an insignificant factor - in the cost of security.</P> -<P>The only thing using a weak cipher can do for you is to cause all - your other investment to be wasted.</P> -<H2><A name="exlaw">Cryptography Export Laws</A></H2> -<P>Many nations restrict the export of cryptography and some restrict - its use by their citizens or others within their borders.</P> -<H3><A name="USlaw">US Law</A></H3> -<P>US laws, as currently interpreted by the US government, forbid export - of most cryptographic software from the US in machine-readable form - without government permission. In general, the restrictions apply even - if the software is widely-disseminated or public-domain and even if it - came from outside the US originally. Cryptography is legally a munition - and export is tightly controlled under the<A href="#EAR"> EAR</A> - Export Administration Regulations.</P> -<P>If you are a US citizen, your brain is considered US territory no - matter where it is physically located at the moment. The US believes - that its laws apply to its citizens everywhere, not just within the US. - Providing technical assistance or advice to foreign "munitions" - projects is illegal. The US government has very little sense of humor - about this issue and does not consider good intentions to be sufficient - excuse. Beware.</P> -<P>The<A href="http://www.bxa.doc.gov/Encryption/"> official website</A> - for these regulations is run by the Commerce Department's Bureau of - Export Administration (BXA).</P> -<P>The<A href="http://www.eff.org/bernstein/"> Bernstein case</A> - challenges the export restrictions on Constitutional grounds. Code is - speech so restrictions on export of code violate the First Amendment's - free speech provisions. This argument has succeeded in two levels of - court so far. It is quite likely to go on to the Supreme Court.</P> -<P>The regulations were changed substantially in January 2000, - apparently as a government attempt to get off the hook in the Bernstein - case. It is now legal to export public domain source code for - encryption, provided you notify the<A href="#BXA"> BXA</A>.</P> -<P>There are, however, still restrictions in force. Moreover, the - regulations can still be changed again whenever the government chooses - to do so. Short of a Supreme Court ruling (in the Berstein case or - another) that overturns the regulations completely, the problem of - export regulation is not likely to go away in the forseeable future.</P> -<H4><A name="UScontrib">US contributions to FreeS/WAN</A></H4> -<P>The FreeS/WAN project<STRONG> cannot accept software contributions,<EM> - not even small bug fixes</EM>, from US citizens or residents</STRONG>. - We want it to be absolutely clear that our distribution is not subject - to US export law. Any contribution from an American might open that - question to a debate we'd prefer to avoid. It might also put the - contributor at serious legal risk.</P> -<P>Of course Americans can still make valuable contributions (many - already have) by reporting bugs, or otherwise contributing to - discussions, on the project<A href="mail.html"> mailing list</A>. Since - the list is public, this is clearly constitutionally protected free - speech.</P> -<P>Note, however, that the export laws restrict Americans from providing - technical assistance to foreign "munitions" projects. The government - might claim that private discussions or correspondence with FreeS/WAN - developers were covered by this. It is not clear what the courts would - do with such a claim, so we strongly encourage Americans to use the - list rather than risk the complications.</P> -<H3><A name="wrong">What's wrong with restrictions on cryptography</A></H3> -<P>Some quotes from prominent cryptography experts:</P> -<BLOCKQUOTE> The real aim of current policy is to ensure the continued - effectiveness of US information warfare assets against individuals, - businesses and governments in Europe and elsewhere. -<BR><A href="http://www.cl.cam.ac.uk/users/rja14"> Ross Anderson, - Cambridge University</A></BLOCKQUOTE><BLOCKQUOTE> If the government - were honest about its motives, then the debate about crypto export - policy would have ended years ago. -<BR><A href="http://www.counterpane.com"> Bruce Schneier, Counterpane - Systems</A></BLOCKQUOTE><BLOCKQUOTE> The NSA regularly lies to people - who ask it for advice on export control. They have no reason not to; - accomplishing their goal by any legal means is fine by them. Lying by - government employees is legal. -<BR> John Gilmore.</BLOCKQUOTE> -<P>The Internet Architecture Board (IAB) and the Internet Engineering - Steering Group (IESG) made a<A href="iab-iesg.stmt"> strong statement</A> - in favour of worldwide access to strong cryptography. Essentially the - same statement is in the appropriately numbered<A href="ftp://ftp.isi.edu/in-notes/rfc1984.txt"> - RFC 1984</A>. Two critical paragraphs are:</P> -<BLOCKQUOTE> ... various governments have actual or proposed policies on - access to cryptographic technology ... -<P>(a) ... export controls ... -<BR> (b) ... short cryptographic keys ... -<BR> (c) ... keys should be in the hands of the government or ... -<BR> (d) prohibit the use of cryptology ...</P> -<P>We believe that such policies are against the interests of consumers - and the business community, are largely irrelevant to issues of - military security, and provide only a marginal or illusory benefit to - law enforcement agencies, ...</P> -<P>The IAB and IESG would like to encourage policies that allow ready - access to uniform strong cryptographic technology for all Internet - users in all countries.</P> -</BLOCKQUOTE> -<P>Our goal in the FreeS/WAN project is to build just such "strong - cryptographic technology" and to distribute it "for all Internet users - in all countries".</P> -<P>More recently, the same two bodies (IESG and IAB) have issued<A href="ftp://ftp.isi.edu/in-notes/rfc2804.txt"> - RFC 2804</A> on why the IETF should not build wiretapping capabilities - into protocols for the convenience of security or law enforcement - agenicies. The abstract from that document is:</P> -<BLOCKQUOTE> The Internet Engineering Task Force (IETF) has been asked - to take a position on the inclusion into IETF standards-track documents - of functionality designed to facilitate wiretapping. -<P>This memo explains what the IETF thinks the question means, why its - answer is "no", and what that answer means.</P> -</BLOCKQUOTE> A quote from the debate leading up to that RFC:<BLOCKQUOTE> - We should not be building surveillance technology into standards. Law - enforcement was not supposed to be easy. Where it is easy, it's called - a police state. -<BR> Jeff Schiller of MIT, in a discussion of FBI demands for wiretap - capability on the net, as quoted by<A href="http://www.wired.com/news/politics/0,1283,31895,00.html"> - Wired</A>.</BLOCKQUOTE> -<P>The<A href="http://www.ietf.org/mailman/listinfo/raven"> Raven</A> - mailing list was set up for this IETF discussion.</P> -<P>Our goal is to go beyond that RFC and prevent Internet wiretapping - entirely.</P> -<H3><A name="Wassenaar">The Wassenaar Arrangement</A></H3> -<P>Restrictions on the export of cryptography are not just US policy, - though some consider the US at least partly to blame for the policies - of other nations in this area.</P> -<P>A number of countries:</P> -<P>Argentina, Australia, Austria, Belgium, Bulgaria, Canada, Czech - Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, - Italy, Japan, Luxembourg, Netherlands, New Zealand, Norway, Poland, - Portugal, Republic of Korea, Romania, Russian Federation, Slovak - Republic, Spain, Sweden, Switzerland, Turkey, Ukraine, United Kingdom - and United States</P> -<P>have signed the Wassenaar Arrangement which restricts export of - munitions and other tools of war. Cryptographic sofware is covered - there.</P> -<P>Wassenaar details are available from the<A href="http://www.wassenaar.org/"> - Wassenaar Secretariat</A>, and elsewhere in a more readable<A href="http://www.fitug.de/news/wa/index.html"> - HTML version</A>.</P> -<P>For a critique see the<A href="http://www.gilc.org/crypto/wassenaar"> - GILC site</A>:</P> -<BLOCKQUOTE> The Global Internet Liberty Campaign (GILC) has begun a - campaign calling for the removal of cryptography controls from the - Wassenaar Arrangement. -<P>The aim of the Wassenaar Arrangement is to prevent the build up of - military capabilities that threaten regional and international security - and stability . . .</P> -<P>There is no sound basis within the Wassenaar Arrangement for the - continuation of any export controls on cryptographic products.</P> -</BLOCKQUOTE> -<P>We agree entirely.</P> -<P>An interesting analysis of Wassenaar can be found on the<A href="http://www.cyber-rights.org/crypto/wassenaar.htm"> - cyber-rights.org</A> site.</P> -<H3><A name="status">Export status of Linux FreeS/WAN</A></H3> -<P>We believe our software is entirely exempt from these controls since - the Wassenaar<A href="http://www.wassenaar.org/list/GTN%20and%20GSN%20-%2099.pdf"> - General Software Note</A> says:</P> -<BLOCKQUOTE> The Lists do not control "software" which is either: -<OL> -<LI>Generally available to the public by . . . retail . . . or</LI> -<LI>"In the public domain".</LI> -</OL> -</BLOCKQUOTE> -<P>There is a note restricting some of this, but it is a sub-heading - under point 1, so it appears not to apply to public domain software.</P> -<P>Their glossary defines "In the public domain" as:</P> -<BLOCKQUOTE> . . . "technology" or "software" which has been made - available without restrictions upon its further dissemination. -<P>N.B. Copyright restrictions do not remove "technology" or "software" - from being "in the public domain".</P> -</BLOCKQUOTE> -<P>We therefore believe that software freely distributed under the<A href="#GPL"> - GNU Public License</A>, such as Linux FreeS/WAN, is exempt from - Wassenaar restrictions.</P> -<P>Most of the development work is being done in Canada. Our - understanding is that the Canadian government accepts this - interpretation.</P> -<UL> -<LI>A web statement of<A href="http://www.dfait-maeci.gc.ca/~eicb/notices/ser113-e.htm"> - Canadian policy</A> is available from the Department of Foreign Affairs - and International Trade.</LI> -<LI>Another document from that department states that<A href="http://www.dfait-maeci.gc.ca/~eicb/export/gr1_e.htm"> - public domain software</A> is exempt from the export controls.</LI> -<LI>A researcher's<A href="http://insight.mcmaster.ca/org/efc/pages/doc/crypto-export.html"> - analysis</A> of Canadian policy is also available.</LI> -</UL> -<P>Recent copies of the freely modifiable and distributable source code - exist in many countries. Citizens all over the world participate in its - use and evolution, and guard its ongoing distribution. Even if Canadian - policy were to change, the software would continue to evolve in - countries which do not restrict exports, and would continue to be - imported from there into unfree countries. "The Net culture treats - censorship as damage, and routes around it."</P> -<H3><A name="help">Help spread IPsec around</A></H3> -<P>You can help. If you don't know of a Linux FreeS/WAN archive in your - own country, please download it now to your personal machine, and - consider making it publicly accessible if that doesn't violate your own - laws. If you have the resources, consider going one step further and - setting up a mirror site for the whole<A href="#munitions"> munitions</A> - Linux crypto software archive.</P> -<P>If you make Linux CD-ROMs, please consider including this code, in a - way that violates no laws (in a free country, or in a domestic-only CD - product).</P> -<P>Please send a note about any new archive mirror sites or CD - distributions to linux-ipsec@clinet.fi so we can update the - documentation.</P> -<P>Lists of current<A href="#sites"> mirror sites</A> and of<A href="#distwith"> - distributions</A> which include FreeS/WAN are in our introduction - section.</P> -<H2><A name="desnotsecure">DES is Not Secure</A></H2> -<P>DES, the<STRONG> D</STRONG>ata<STRONG> E</STRONG>ncryption<STRONG> S</STRONG> -tandard, can no longer be considered secure. While no major flaws in its - innards are known, it is fundamentally inadequate because its<STRONG> - 56-bit key is too short</STRONG>. It is vulnerable to<A href="#brute"> - brute-force search</A> of the whole key space, either by large - collections of general-purpose machines or even more quickly by - specialized hardware. Of course this also applies to<STRONG> any other - cipher with only a 56-bit key</STRONG>. The only reason anyone could - have for using a 56 or 64-bit key is to comply with various<A href="exportlaw.html"> - export laws</A> intended to ensure the use of breakable ciphers.</P> -<P>Non-government cryptologists have been saying DES's 56-bit key was - too short for some time -- some of them were saying it in the 70's when - DES became a standard -- but the US government has consistently - ridiculed such suggestions.</P> -<P>A group of well-known cryptographers looked at key lengths in a<A href="http://www.counterpane.com/keylength.html"> - 1996 paper</A>. They suggested a<EM> minimum</EM> of 75 bits to - consider an existing cipher secure and a<EM> minimum of 90 bits for new - ciphers</EM>. More recent papers, covering both<A href="#symmetric"> - symmetric</A> and<A href="#public"> public key</A> systems are at<A href="http://www.cryptosavvy.com/"> - cryptosavvy.com</A> and<A href="http://www.rsasecurity.com/rsalabs/bulletins/bulletin13.html"> - rsa.com</A>. For all algorithms, the minimum keylengths recommended in - such papers are significantly longer than the maximums allowed by - various export laws.</P> -<P>In a<A href="http://www.privacy.nb.ca/cryptography/archives/cryptography/html/1998-09/0095.html"> - 1998 ruling</A>, a German court described DES as "out-of-date and not - safe enough" and held a bank liable for using it.</P> -<H3><A name="deshware">Dedicated hardware breaks DES in a few days</A></H3> -<P>The question of DES security has now been settled once and for all. - In early 1998, the<A href="http://www.eff.org/"> Electronic Frontier - Foundation</A> built a<A href="http://www.eff.org/descracker.html"> - DES-cracking machine</A>. It can find a DES key in an average of a few - days' search. The details of all this, including complete code listings - and complete plans for the machine, have been published in<A href="#EFF"> -<CITE> Cracking DES</CITE></A>, by the Electronic Frontier Foundation.</P> -<P>That machine cost just over $200,000 to design and build. "Moore's - Law" is that machines get faster (or cheaper, for the same speed) by - roughly a factor of two every 18 months. At that rate, their $200,000 - in 1998 becomes $50,000 in 2001.</P> -<P>However, Moore's Law is not exact and the $50,000 estimate does not - allow for the fact that a copy based on the published EFF design would - cost far less than the original. We cannot say exactly what such a - cracker would cost today, but it would likely be somewhere between - $10,000 and $100,000.</P> -<P>A large corporation could build one of these out of petty cash. The - cost is low enough for a senior manager to hide it in a departmental - budget and avoid having to announce or justify the project. Any - government agency, from a major municipal police force up, could afford - one. Or any other group with a respectable budget -- criminal - organisations, political groups, labour unions, religious groups, ... - Or any millionaire with an obsession or a grudge, or just strange taste - in toys.</P> -<P>One might wonder if a private security or detective agency would have - one for rent. They wouldn't need many clients to pay off that - investment.</P> -<H3><A name="spooks">Spooks may break DES faster yet</A></H3> -<P>As for the security and intelligence agencies of various nations, - they may have had DES crackers for years, and theirs may be much - faster. It is difficult to make most computer applications work well on - parallel machines, or to design specialised hardware to accelerate - them. Cipher-cracking is one of the very few exceptions. It is entirely - straightforward to speed up cracking by just adding hardware. Within - very broad limits, you can make it as fast as you like if you have the - budget. The EFF's $200,000 machine breaks DES in a few days. An<A href="http://www.planepage.com/"> - aviation website</A> gives the cost of a B1 bomber as $200,000,000. - Spending that much, an intelligence agency could break DES in an - average time of<EM> six and a half minutes</EM>.</P> -<P>That estimate assumes they use the EFF's 1998 technology and just - spend more money. They may have an attack that is superior to brute - force, they quite likely have better chip technology (Moore's law, a - bigger budget, and whatever secret advances they may have made) and of - course they may have spent the price of an aircraft carrier, not just - one aircraft.</P> -<P>In short, we have<EM> no idea</EM> how quickly these organisations - can break DES. Unless they're spectacularly incompetent or horribly - underfunded, they can certainly break it, but we cannot guess how - quickly. Pick any time unit between days and milliseconds; none is - entirely unbelievable. More to the point, none of them is of any - comfort if you don't want such organisations reading your - communications.</P> -<P>Note that this may be a concern even if nothing you do is a threat to - anyone's national security. An intelligence agency might well consider - it to be in their national interest for certain companies to do well. - If you're competing against such companies in a world market and that - agency can read your secrets, you have a serious problem.</P> -<P>One might wonder about technology the former Soviet Union and its - allies developed for cracking DES during the Cold War. They must have - tried; the cipher was an American standard and widely used. Certainly - those countries have some fine mathematicians, and those agencies had - budget. How well did they succeed? Is their technology now for sale or - rent?</P> -<H3><A name="desnet">Networks break DES in a few weeks</A></H3> -<P>Before the definitive EFF effort, DES had been cracked several times - by people using many machines. See this<A href="http://www.distributed.net/pressroom/DESII-1-PR.html"> - press release</A> for example.</P> -<P>A major corporation, university, or government department could break - DES by using spare cycles on their existing collection of computers, by - dedicating a group of otherwise surplus machines to the problem, or by - combining the two approaches. It might take them weeks or months, - rather than the days required for the EFF machine, but they could do - it.</P> -<P>What about someone working alone, without the resources of a large - organisation? For them, cracking DES will not be easy, but it may be - possible. A few thousand dollars buys a lot of surplus workstations. A - pile of such machines will certainly heat your garage nicely and might - break DES in a few months or years. Or enroll at a university and use - their machines. Or use an employer's machines. Or crack security - somewhere and steal the resources to crack a DES key. Or write a virus - that steals small amounts of resources on many machines. Or . . .</P> -<P>None of these approaches are easy or break DES really quickly, but an - attacker only needs to find one that is feasible and breaks DES quickly - enough to be dangerous. How much would you care to bet that this will - be impossible if the attacker is clever and determined? How valuable is - your data? Are you authorised to risk it on a dubious bet?</P> -<H3><A name="no_des">We disable DES</A></H3> -<P>In short, it is now absolutely clear that<STRONG> DES is not secure</STRONG> - against</P> -<UL> -<LI>any<STRONG> well-funded opponent</STRONG></LI> -<LI>any opponent (even a penniless one) with access (even stolen access) - to<STRONG> enough general purpose computers</STRONG></LI> -</UL> -<P>That is why<STRONG> Linux FreeS/WAN disables all transforms which use - plain DES</STRONG> for encryption.</P> -<P>DES is in the source code, because we need DES to implement our - default encryption transform,<A href="#3DES"> Triple DES</A>.<STRONG> - We urge you not to use single DES</STRONG>. We do not provide any easy - way to enable it in FreeS/WAN, and our policy is to provide no - assistance to anyone wanting to do so.</P> -<H3><A name="40joke">40-bits is laughably weak</A></H3> -<P>The same is true, in spades, of ciphers -- DES or others -- crippled - by 40-bit keys, as many ciphers were required to be until recently - under various<A href="#exlaw"> export laws</A>. A brute force search of - such a cipher's keyspace is 2<SUP>16</SUP> times faster than a similar - search against DES. The EFF's machine can do a brute-force search of a - 40-bit key space in<EM> seconds</EM>. One contest to crack a 40-bit - cipher was won by a student<A href="http://catless.ncl.ac.uk/Risks/18.80.html#subj1"> - using a few hundred idle machines at his university</A>. It took only - three and half hours.</P> -<P>We do not, and will not, implement any 40-bit cipher.</P> -<H3><A name="altdes">Triple DES is almost certainly secure</A></H3> -<P><A href="#3DES">Triple DES</A>, usually abbreviated 3DES, applies DES - three times, with three different keys. DES seems to be basically an - excellent cipher design; it has withstood several decades of intensive - analysis without any disastrous flaws being found. It's only major flaw - is that the small keyspace allows brute force attacks to succeeed. - Triple DES enlarges the key space to 168 bits, making brute-force - search a ridiculous impossibility.</P> -<P>3DES is currently the only block cipher implemented in FreeS/WAN. - 3DES is, unfortunately, about 1/3 the speed of DES, but modern CPUs - still do it at quite respectable speeds. Some<A href="#benchmarks"> - speed measurements</A> for our code are available.</P> -<H3><A name="aes.ipsec">AES in IPsec</A></H3> -<P>The<A href="#AES"> AES</A> project has chosen a replacement for DES, - a new standard cipher for use in non-classified US government work and - in regulated industries such as banking. This cipher will almost - certainly become widely used for many applications, including IPsec.</P> -<P>The winner, announced in October 2000 after several years of analysis - and discussion, was the<A href="http://www.esat.kuleuven.ac.be/~rijmen/rijndael/"> - Rijndael</A> cipher from two Belgian designers.</P> -<P>It is almost certain that FreeS/WAN will add AES support.<A href="#patch"> - AES patches</A> are already available.</P> -<H2><A name="press">Press coverage of Linux FreeS/WAN:</A></H2> -<H3><A NAME="26_6_1">FreeS/WAN 1.0 press</A></H3> -<UL> -<LI><A href="http://www.wired.com/news/news/technology/story/19136.html"> -Wired</A> "Linux-Based Crypto Stops Snoops", James Glave April 15 1999</LI> -<LI><A href="http://slashdot.org/articles/99/04/15/1851212.shtml"> -Slashdot</A></LI> -<LI><A href="http://dgl.com/itinfo/1999/it990415.html">DGL</A>, Damar - Group Limited; looking at FreeS/WAN from a perspective of business - computing</LI> -<LI><A href="http://linuxtoday.com/stories/5010.html">Linux Today</A></LI> -<LI><A href="http://www.tbtf.com/archive/1999-04-21.html#Tcep">TBTF</A>, - Tasty Bits from the Technology Front</LI> -<LI><A href="http://www.salonmagazine.com/tech/log/1999/04/16/encryption/index.html"> -Salon Magazine</A> "Free Encryption Takes a Big Step"</LI> -</UL> -<H3><A name="release">Press release for version 1.0</A></H3> -<PRE> Strong Internet Privacy Software Free for Linux Users Worldwide - -Toronto, ON, April 14, 1999 - - -The Linux FreeS/WAN project today released free software to protect -the privacy of Internet communications using strong encryption codes. -FreeS/WAN automatically encrypts data as it crosses the Internet, to -prevent unauthorized people from receiving or modifying it. One -ordinary PC per site runs this free software under Linux to become a -secure gateway in a Virtual Private Network, without having to modify -users' operating systems or application software. The project built -and released the software outside the United States, avoiding US -government regulations which prohibit good privacy protection. -FreeS/WAN version 1.0 is available immediately for downloading at -http://www.xs4all.nl/~freeswan/. - -"Today's FreeS/WAN release allows network administrators to build -excellent secure gateways out of old PCs at no cost, or using a cheap -new PC," said John Gilmore, the entrepreneur who instigated the -project in 1996. "They can build operational experience with strong -network encryption and protect their users' most important -communications worldwide." - -"The software was written outside the United States, and we do not -accept contributions from US citizens or residents, so that it can be -freely published for use in every country," said Henry Spencer, who -built the release in Toronto, Canada. "Similar products based in the -US require hard-to-get government export licenses before they can be -provided to non-US users, and can never be simply published on a Web -site. Our product is freely available worldwide for immediate -downloading, at no cost." - -FreeS/WAN provides privacy against both quiet eavesdropping (such as -"packet sniffing") and active attempts to compromise communications -(such as impersonating participating computers). Secure "tunnels" carry -information safely across the Internet between locations such as a -company's main office, distant sales offices, and roaming laptops. This -protects the privacy and integrity of all information sent among those -locations, including sensitive intra-company email, financial transactions -such as mergers and acquisitions, business negotiations, personal medical -records, privileged correspondence with lawyers, and information about -crimes or civil rights violations. The software will be particularly -useful to frequent wiretapping targets such as private companies competing -with government-owned companies, civil rights groups and lawyers, -opposition political parties, and dissidents. - -FreeS/WAN provides privacy for Internet packets using the proposed -standard Internet Protocol Security (IPSEC) protocols. FreeS/WAN -negotiates strong keys using Diffie-Hellman key agreement with 1024-bit -keys, and encrypts each packet with 168-bit Triple-DES (3DES). A modern -$500 PC can set up a tunnel in less than a second, and can encrypt -6 megabits of packets per second, easily handling the whole available -bandwidth at the vast majority of Internet sites. In preliminary testing, -FreeS/WAN interoperated with 3DES IPSEC products from OpenBSD, PGP, SSH, -Cisco, Raptor, and Xedia. Since FreeS/WAN is distributed as source code, -its innards are open to review by outside experts and sophisticated users, -reducing the chance of undetected bugs or hidden security compromises. - -The software has been in development for several years. It has been -funded by several philanthropists interested in increased privacy on -the Internet, including John Gilmore, co-founder of the Electronic -Frontier Foundation, a leading online civil rights group. - -Press contacts: -Hugh Daniel, +1 408 353 8124, hugh@toad.com -Henry Spencer, +1 416 690 6561, henry@spsystems.net - -* FreeS/WAN derives its name from S/WAN, which is a trademark of RSA Data - Security, Inc; used by permission.</PRE> -<HR> -<H1><A name="ipsec.detail">The IPsec protocols</A></H1> -<P>This section provides information on the IPsec protocols which - FreeS/WAN implements. For more detail, see the<A href="rfc.html"> RFCs</A> -.</P> -<P>The basic idea of IPsec is to provide security functions,<A href="#authentication"> - authentication</A> and<A href="#encryption"> encryption</A>, at the IP - (Internet Protocol) level. This requires a higher-level protocol (IKE) - to set things up for the IP-level services (ESP and AH).</P> -<H2><A NAME="27_1">Protocols and phases</A></H2> -<P>Three protocols are used in an IPsec implementation:</P> -<DL> -<DT>ESP, Encapsulating Security Payload</DT> -<DD>Encrypts and/or authenticates data</DD> -<DT>AH, Authentication Header</DT> -<DD>Provides a packet authentication service</DD> -<DT>IKE, Internet Key Exchange</DT> -<DD>Negotiates connection parameters, including keys, for the other two</DD> -</DL> -<P>The term "IPsec" (also written as IPSEC) is slightly ambiguous. In - some contexts, it includes all three of the above but in other contexts - it refers only to AH and ESP.</P> -<P>There is more detail below, but a quick summary of how the whole - thing works is:</P> -<DL> -<DT>Phase one IKE (main mode exchange)</DT> -<DD>sets up a keying channel (ISAKMP SA) between the two gateways</DD> -<DT>Phase two IKE (quick mode exchange)</DT> -<DD>sets up data channels (IPsec SAs)</DD> -<DT>IPsec proper</DT> -<DD>exchanges data using AH or ESP</DD> -</DL> -<P>Both phases of IKE are repeated periodically to automate re-keying.</P> -<H2><A name="others">Applying IPsec</A></H2> -<P>Authentication and encryption functions for network data can, of - course, be provided at other levels. Many security protocols work at - levels above IP.</P> -<UL> -<LI><A href="#PGP">PGP</A> encrypts and authenticates mail messages</LI> -<LI><A href="#ssh">SSH</A> authenticates remote logins and then encrypts - the session</LI> -<LI><A href="#SSL">SSL</A> or<A href="#TLS"> TLS</A> provides security - at the sockets layer, e.g. for secure web browsing</LI> -</UL> -<P>and so on. Other techniques work at levels below IP. For example, - data on a communications circuit or an entire network can be encrypted - by specialised hardware. This is common practice in high-security - applications.</P> -<H3><A name="advantages">Advantages of IPsec</A></H3> -<P>There are, however, advantages to doing it at the IP level instead - of, or as well as, at other levels.</P> -<P>IPsec is the<STRONG> most general way to provide these services for - the Internet</STRONG>.</P> -<UL> -<LI>Higher-level services protect a<EM> single protocol</EM>; for - example PGP protects mail.</LI> -<LI>Lower level services protect a<EM> single medium</EM>; for example a - pair of encryption boxes on the ends of a line make wiretaps on that - line useless unless the attacker is capable of breaking the encryption.</LI> -</UL> -<P>IPsec, however, can protect<EM> any protocol</EM> running above IP - and<EM> any medium</EM> which IP runs over. More to the point, it can - protect a mixture of application protocols running over a complex - combination of media. This is the normal situation for Internet - communication; IPsec is the only general solution.</P> -<P>IPsec can also provide some security services "in the background", - with<STRONG> no visible impact on users</STRONG>. To use<A href="#PGP"> - PGP</A> encryption and signatures on mail, for example, the user must - at least:</P> -<UL> -<LI>remember his or her passphrase,</LI> -<LI>keep it secure</LI> -<LI>follow procedures to validate correspondents' keys</LI> -</UL> -<P>These systems can be designed so that the burden on users is not - onerous, but any system will place some requirements on users. No such - system can hope to be secure if users are sloppy about meeting those - requirements. The author has seen username and password stuck on - terminals with post-it notes in an allegedly secure environment, for - example.</P> -<H3><A name="limitations">Limitations of IPsec</A></H3> -<P>IPsec is designed to secure IP links between machines. It does that - well, but it is important to remember that there are many things it - does not do. Some of the important limitations are:</P> -<DL> -<DT><A name="depends">IPsec cannot be secure if your system isn't</A></DT> -<DD>System security on IPsec gateway machines is an essential - requirement if IPsec is to function as designed. No system can be - trusted if the underlying machine has been subverted. See books on Unix - security such as<A href="#practical"> Garfinkel and Spafford</A> or our - web references for<A href="#linsec"> Linux security</A> or more general<A -href="#compsec"> computer security</A>. -<P>Of course, there is another side to this. IPsec can be a powerful - tool for improving system and network security. For example, requiring - packet authentication makes various spoofing attacks harder and IPsec - tunnels can be extremely useful for secure remote administration of - various things.</P> -</DD> -<DT><A name="not-end-to-end">IPsec is not end-to-end</A></DT> -<DD>IPsec cannot provide the same end-to-end security as systems working - at higher levels. IPsec encrypts an IP connection between two machines, - which is quite a different thing than encrypting messages between users - or between applications. -<P>For example, if you need mail encrypted from the sender's desktop to - the recipient's desktop and decryptable only by the recipient, use<A href="#PGP"> - PGP</A> or another such system. IPsec can encrypt any or all of the - links involved -- between the two mail servers, or between either - server and its clients. It could even be used to secure a direct IP - link from the sender's desktop machine to the recipient's, cutting out - any sort of network snoop. What it cannot ensure is end-to-end - user-to-user security. If only IPsec is used to secure mail, then - anyone with appropriate privileges on any machine where that mail is - stored (at either end or on any store-and-forward servers in the path) - can read it.</P> -<P>In another common setup, IPsec encrypts packets at a security gateway - machine as they leave the sender's site and decrypts them on arrival at - the gateway to the recipient's site. This does provide a useful - security service -- only encrypted data is passed over the Internet -- - but it does not even come close to providing an end-to-end service. In - particular, anyone with appropriate privileges on either site's LAN can - intercept the message in unencrypted form.</P> -</DD> -<DT><A name="notpanacea">IPsec cannot do everything</A></DT> -<DD>IPsec also cannot provide all the functions of systems working at - higher levels of the protocol stack. If you need a document - electronically signed by a particular person, then you need his or her<A -href="#signature"> digital signature</A> and a<A href="#public"> public - key cryptosystem</A> to verify it with. -<P>Note, however, that IPsec authentication of the underlying - communication can make various attacks on higher-level protocols more - difficult. In particular, authentication prevents<A href="#middle"> - man-in-the-middle attacks</A>.</P> -</DD> -<DT><A name="no_user">IPsec authenticates machines, not users</A></DT> -<DD>IPsec uses strong authentication mechanisms to control which - messages go to which machines, but it does not have the concept of user - ID, which is vital to many other security mechansims and policies. This - means some care must be taken in fitting the various security - mechansims on a network together. For example, if you need to control - which users access your database server, you need some non-IPsec - mechansim for that. IPsec can control which machines connect to the - server, and can ensure that data transfer to those machines is done - securely, but that is all. Either the machines themselves must control - user access or there must be some form of user authentication to the - database, independent of IPsec.</DD> -<DT><A name="DoS">IPsec does not stop denial of service attacks</A></DT> -<DD><A href="#DOS">Denial of service</A> attacks aim at causing a system - to crash, overload, or become confused so that legitimate users cannot - get whatever services the system is supposed to provide. These are - quite different from attacks in which the attacker seeks either to use - the service himself or to subvert the service into delivering incorrect - results. -<P>IPsec shifts the ground for DoS attacks; the attacks possible against - systems using IPsec are different than those that might be used against - other systems. It does not, however, eliminate the possibility of such - attacks.</P> -</DD> -<DT><A name="traffic">IPsec does not stop traffic analysis</A></DT> -<DD><A href="#traffic">Traffic analysis</A> is the attempt to derive - intelligence from messages without regard for their contents. In the - case of IPsec, it would mean analysis based on things visible in the - unencrypted headers of encrypted packets -- source and destination - gateway addresses, packet size, et cetera. Given the resources to - acquire such data and some skill in analysing it (both of which any - national intelligence agency should have), this can be a very powerful - technique. -<P>IPsec is not designed to defend against this. Partial defenses are - certainly possible, and some are<A href="#traffic.resist"> described - below</A>, but it is not clear that any complete defense can be - provided.</P> -</DD> -</DL> -<H3><A name="uses">IPsec is a general mechanism for securing IP</A></H3> -<P>While IPsec does not provide all functions of a mail encryption - package, it can encrypt your mail. In particular, it can ensure that - all mail passing between a pair or a group of sites is encrypted. An - attacker looking only at external traffic, without access to anything - on or behind the IPsec gateway, cannot read your mail. He or she is - stymied by IPsec just as he or she would be by<A href="#PGP"> PGP</A>.</P> -<P>The advantage is that IPsec can provide the same protection for<STRONG> - anything transmitted over IP</STRONG>. In a corporate network example, - PGP lets the branch offices exchange secure mail with head office. SSL - and SSH allow them to securely view web pages, connect as terminals to - machines, and so on. IPsec can support all those applications, plus - database queries, file sharing (NFS or Windows), other protocols - encapsulated in IP (Netware, Appletalk, ...), phone-over-IP, - video-over-IP, ... anything-over-IP. The only limitation is that IP - Multicast is not yet supported, though there are Internet Draft - documents for that.</P> -<P>IPsec creates<STRONG> secure tunnels through untrusted networks</STRONG> -. Sites connected by these tunnels form VPNs,<A href="#VPN"> Virtual - Private Networks</A>.</P> -<P>IPsec gateways can be installed wherever they are required.</P> -<UL> -<LI>One organisation might choose to install IPsec only on firewalls - between their LANs and the Internet. This would allow them to create a - VPN linking several offices. It would provide protection against anyone - outside their sites.</LI> -<LI>Another might install IPsec on departmental servers so everything on - the corporate backbone net was encrypted. This would protect messages - on that net from everyone except the sending and receiving department.</LI> -<LI>Another might be less concerned with information secrecy and more - with controlling access to certain resources. They might use IPsec - packet authentication as part of an access control mechanism, with or - without also using the IPsec encryption service.</LI> -<LI>It is even possible (assuming adequate processing power and an IPsec - implementation in each node) to make every machine its own IPsec - gateway so that everything on a LAN is encrypted. This protects - information from everyone outside the sending and receiving machine.</LI> -<LI>These techniques can be combined in various ways. One might, for - example, require authentication everywhere on a network while using - encryption only for a few links.</LI> -</UL> -<P>Which of these, or of the many other possible variants, to use is up - to you.<STRONG> IPsec provides mechanisms; you provide the policy</STRONG> -.</P> -<P><STRONG>No end user action is required</STRONG> for IPsec security to - be used; they don't even have to know about it. The site - administrators, of course, do have to know about it and to put some - effort into making it work. Poor administration can compromise IPsec as - badly as the post-it notes mentioned above. It seems reasonable, - though, for organisations to hope their system administrators are - generally both more security-conscious than end users and more able to - follow computer security procedures. If not, at least there are fewer - of them to educate or replace.</P> -<P>IPsec can be, and often should be, used with along with security - protocols at other levels. If two sites communicate with each other via - the Internet, then IPsec is the obvious way to protect that - communication. If two others have a direct link between them, either - link encryption or IPsec would make sense. Choose one or use both. - Whatever you use at and below the IP level, use other things as - required above that level. Whatever you use above the IP level, - consider what can be done with IPsec to make attacks on the higher - levels harder. For example,<A href="#middle"> man-in-the-middle attacks</A> - on various protocols become difficult if authentication at packet level - is in use on the potential victims' communication channel.</P> -<H3><A name="authonly">Using authentication without encryption</A></H3> -<P>Where appropriate, IPsec can provide authentication without - encryption. One might do this, for example:</P> -<UL> -<LI>where the data is public but one wants to be sure of getting the - right data, for example on some web sites</LI> -<LI>where encryption is judged unnecessary, for example on some company - or department LANs</LI> -<LI>where strong encryption is provided at link level, below IP</LI> -<LI>where strong encryption is provided in other protocols, above IP -<BR> Note that IPsec authentication may make some attacks on those - protocols harder.</LI> -</UL> -<P>Authentication has lower overheads than encryption.</P> -<P>The protocols provide four ways to build such connections, using - either an AH-only connection or ESP using null encryption, and in - either manually or automatically keyed mode. FreeS/WAN supports only - one of these, manually keyed AH-only connections, and<STRONG> we do not - recommend using that</STRONG>. Our reasons are discussed under<A href="#traffic.resist"> - Resisting traffic analysis</A> a few sections further along.</P> -<H3><A name="encnoauth">Encryption without authentication is dangerous</A> -</H3> -<P>Originally, the IPsec encryption protocol<A href="#ESP"> ESP</A> - didn't do integrity checking. It only did encryption. Steve Bellovin - found many ways to attack ESP used without authentication. See his - paper<A href="http://www.research.att.com/~smb/papers/badesp.ps"> - Problem areas for the IP Security Protocols</A>. To make a secure - connection, you had to add an<A href="#AH"> AH</A> Authentication - Header as well as ESP. Rather than incur the overhead of several layers - (and rather than provide an ESP layer that didn't actually protect the - traffic), the IPsec working group built integrity and replay checking - directly into ESP.</P> -<P>Today, typical usage is one of:</P> -<UL> -<LI>ESP for encryption and authentication</LI> -<LI>AH for authentication alone</LI> -</UL> -<P>Other variants are allowed by the standard, but not much used:</P> -<DL> -<DT>ESP encryption without authentication</DT> -<DD><STRONG>Bellovin has demonstrated fatal flaws in this. Do not use.</STRONG> -</DD> -<DT>ESP encryption with AH authentication</DT> -<DD>This has higher overheads than using the authentication in ESP, and - no obvious benefit in most cases. The exception might be a network - where AH authentication was widely or universally used. If you're going - to do AH to conform with network policy, why authenticate again in the - ESP layer?</DD> -<DT>Authenticate twice, with AH and with ESP</DT> -<DD>Why? Of course, some folk consider "belt and suspenders" the - sensible approach to security. If you're among them, you might use both - protocols here. You might also use both to satisfy different parts of a - security policy. For example, an organisation might require AH - authentication everywhere but two users within the organisation might - use ESP as well.</DD> -<DT>ESP authentication without encryption</DT> -<DD>The standard allows this, calling it "null encryption". FreeS/WAN - does not support it. We recommend that you use AH instead if - authentication is all you require. AH authenticates parts of the IP - header, which ESP-null does not do.</DD> -</DL> -<P>Some of these variants cannot be used with FreeS/WAN because we do - not support ESP-null and do not support automatic keying of AH-only - connections.</P> -<P>There are fairly frequent suggestions that AH be dropped entirely - from the IPsec specifications since ESP and null encryption can handle - that situation. It is not clear whether this will occur. My guess is - that it is unlikely.</P> -<H3><A name="multilayer">Multiple layers of IPsec processing are - possible</A></H3> -<P>The above describes combinations possible on a single IPsec - connection. In a complex network you may have several layers of IPsec - in play, with any of the above combinations at each layer.</P> -<P>For example, a connection from a desktop machine to a database server - might require AH authentication. Working with other host, network and - database security measures, AH might be just the thing for access - control. You might decide not to use ESP encryption on such packets, - since it uses resources and might complicate network debugging. Within - the site where the server is, then, only AH would be used on those - packets.</P> -<P>Users at another office, however, might have their whole connection - (AH headers and all) passing over an IPsec tunnel connecting their - office to the one with the database server. Such a tunnel should use - ESP encryption and authentication. You need authentication in this - layer because without authentication the encryption is vulnerable and - the gateway cannot verify the AH authentication. The AH is between - client and database server; the gateways aren't party to it.</P> -<P>In this situation, some packets would get multiple layers of IPsec - applied to them, AH on an end-to-end client-to-server basis and ESP - from one office's security gateway to the other.</P> -<H3><A name="traffic.resist">Resisting traffic analysis</A></H3> -<P><A href="#traffic">Traffic analysis</A> is the attempt to derive - useful intelligence from encrypted traffic without breaking the - encryption.</P> -<P>Is your CEO exchanging email with a venture capital firm? With - bankruptcy trustees? With an executive recruiting agency? With the - holder of some important patents? If an eavesdropper learns about any - of those, then he has interesting intelligence on your company, whether - or not he can read the messages themselves.</P> -<P>Even just knowing that there is network traffic between two sites may - tell an analyst something useful, especially when combined with - whatever other information he or she may have. For example, if you know - Company A is having cashflow problems and Company B is looking for - aquisitions, then knowing that packets are passing between the two is - interesting. It is more interesting if you can tell it is email, and - perhaps yet more if you know the sender and recipient.</P> -<P>Except in the simplest cases, traffic analysis is hard to do well. It - requires both considerable resources and considerable analytic skill. - However, intelligence agencies of various nations have been doing it - for centuries and many of them are likely quite good at it by now. - Various commercial organisations, especially those working on "targeted - marketing" may also be quite good at analysing certain types of - traffic.</P> -<P>In general, defending against traffic analysis is also difficult. - Inventing a really good defense could get you a PhD and some - interesting job offers.</P> -<P>IPsec is not designed to stop traffic analysis and we know of no - plausible method of extending it to do so. That said, there are ways to - make traffic analysis harder. This section describes them.</P> -<H4><A name="extra">Using "unnecessary" encryption</A></H4> -<P>One might choose to use encryption even where it appears unnecessary - in order to make analysis more difficult. Consider two offices which - pass a small volume of business data between them using IPsec and also - transfer large volumes of Usenet news. At first glance, it would seem - silly to encrypt the newsfeed, except possibly for any newsgroups that - are internal to the company. Why encrypt data that is all publicly - available from many sites?</P> -<P>However, if we encrypt a lot of news and send it down the same - connection as our business data, we make<A href="#traffic"> traffic - analysis</A> much harder. A snoop cannot now make inferences based on - patterns in the volume, direction, sizes, sender, destination, or - timing of our business messages. Those messages are hidden in a mass of - news messages encapsulated in the same way.</P> -<P>If we're going to do this we need to ensure that keys change often - enough to remain secure even with high volumes and with the adversary - able to get plaintext of much of the data. We also need to look at - other attacks this might open up. For example, can the adversary use a - chosen plaintext attack, deliberately posting news articles which, when - we receive and encrypt them, will help break our encryption? Or can he - block our business data transmission by flooding us with silly news - articles? Or ...</P> -<P>Also, note that this does not provide complete protection against - traffic analysis. A clever adversary might still deduce useful - intelligence from statistical analysis (perhaps comparing the input - newsfeed to encrypted output, or comparing the streams we send to - different branch offices), or by looking for small packets which might - indicate establishment of TCP connections, or ...</P> -<P>As a general rule, though, to improve resistance to traffic analysis, - you should<STRONG> encrypt as much traffic as possible, not just as - much as seems necessary.</STRONG></P> -<H4><A name="multi-encrypt">Using multiple encryption</A></H4> -<P>This also applies to using multiple layers of encryption. If you have - an IPsec tunnel between two branch offices, it might appear silly to - send<A href="#PGP"> PGP</A>-encrypted email through that tunnel. - However, if you suspect someone is snooping your traffic, then it does - make sense:</P> -<UL> -<LI>it protects the mail headers; they cannot even see who is mailing - who</LI> -<LI>it protects against user bungles or software malfunctions that - accidentally send messages in the clear</LI> -<LI>it makes any attack on the mail encryption much harder; they have to - break IPsec or break into your network before they can start on the - mail encryption</LI> -</UL> -<P>Similar arguments apply for<A href="#SSL"> SSL</A>-encrypted web - traffic or<A href="#ssh"> SSH</A>-encrypted remote login sessions, even - for end-to-end IPsec tunnels between systems in the two offices.</P> -<H4><A name="fewer">Using fewer tunnels</A></H4> -<P>It may also help to use fewer tunnels. For example, if all you - actually need encrypted is connections between:</P> -<UL> -<LI>mail servers at branch and head offices</LI> -<LI>a few branch office users and the head office database server</LI> -</UL> -<P>You might build one tunnel per mail server and one per remote - database user, restricting traffic to those applications. This gives - the traffic analyst some information, however. He or she can - distinguish the tunnels by looking at information in the ESP header - and, given that distinction and the patterns of tunnel usage, might be - able to figure out something useful. Perhaps not, but why take the - risk?</P> -<P>We suggest instead that you build one tunnel per branch office, - encrypting everything passing from head office to branches. This has a - number of advantages:</P> -<UL> -<LI>it is easier to build and administer</LI> -<LI>it resists traffic analysis somewhat better</LI> -<LI>it provides security for whatever you forgot. For example, if some - user at a remote office browses proprietary company data on some head - office web page (that the security people may not even know about!), - then that data is encrypted before it reaches the Internet.</LI> -</UL> -<P>Of course you might also want to add additional tunnels. For example, - if some of the database data is confidential and should not be exposed - even within the company, then you need protection from the user's - desktop to the database server. We suggest you do that in whatever way - seems appropriate -- IPsec, SSH or SSL might fit -- but, whatever you - choose, pass it between locations via a gateway-to-gateway IPsec tunnel - to provide some resistance to traffic analysis.</P> -<H2><A name="primitives">Cryptographic components</A></H2> -<P>IPsec combines a number of cryptographic techniques, all of them - well-known and well-analyzed. The overall design approach was - conservative; no new or poorly-understood components were included.</P> -<P>This section gives a brief overview of each technique. It is intended - only as an introduction. There is more information, and links to - related topics, in our<A href="glossary.html"> glossary</A>. See also - our<A href="biblio.html"> bibliography</A> and cryptography<A href="#crypto.link"> - web links</A>.</P> -<H3><A name="block.cipher">Block ciphers</A></H3> -<P>The<A href="#encryption"> encryption</A> in the<A href="#ESP"> ESP</A> - encapsulation protocol is done with a<A href="#block"> block cipher</A> -.</P> -<P>We do not implement<A href="#DES"> single DES</A>. It is<A href="#desnotsecure"> - insecure</A>. Our default, and currently only, block cipher is<A href="#3DES"> - triple DES</A>.</P> -<P>The<A href="#rijndael"> Rijndael</A> block cipher has won the<A href="#AES"> - AES</A> competition to choose a relacement for DES. It will almost - certainly be added to FreeS/WAN and to other IPsec implementations.<A href="#patch"> - Patches</A> are already available.</P> -<H3><A name="hash.ipsec">Hash functions</A></H3> -<H4><A name="hmac.ipsec">The HMAC construct</A></H4> -<P>IPsec packet authentication is done with the<A href="#HMAC"> HMAC</A> - construct. This is not just a hash of the packet data, but a more - complex operation which uses both a hashing algorithm and a key. It - therefore does more than a simple hash would. A simple hash would only - tell you that the packet data was not changed in transit, or that - whoever changed it also regenerated the hash. An HMAC also tells you - that the sender knew the HMAC key.</P> -<P>For IPsec HMAC, the output of the hash algorithm is truncated to 96 - bits. This saves some space in the packets. More important, it prevents - an attacker from seeing all the hash output bits and perhaps creating - some sort of attack based on that knowledge.</P> -<H4><A NAME="27_3_2_2">Choice of hash algorithm</A></H4> -<P>The IPsec RFCs require two hash algorithms --<A href="#MD5"> MD5</A> - and<A href="#SHA"> SHA-1</A> -- both of which FreeS/WAN implements.</P> -<P>Various other algorithms -- such as RIPEMD and Tiger -- are listed in - the RFCs as optional. None of these are in the FreeS/WAN distribution, - or are likely to be added, although user<A href="#patch"> patches</A> - exist for several of them.</P> -<P>Additional hash algorithms --<A href="#SHA-256"> SHA-256, SHA-384 and - SHA-512</A> -- may be required to give hash strength matching the - strength of<A href="#AES"> AES</A>. These are likely to be added to - FreeS/WAN along with AES.</P> -<H3><A name="DH.keying">Diffie-Hellman key agreement</A></H3> -<P>The<A href="#DH"> Diffie-Hellman</A> key agreement protocol allows - two parties (A and B or<A href="#alicebob"> Alice and Bob</A>) to agree - on a key in such a way that an eavesdropper who intercepts the entire - conversation cannot learn the key.</P> -<P>The protocol is based on the<A href="#dlog"> discrete logarithm</A> - problem and is therefore thought to be secure. Mathematicians have been - working on that problem for years and seem no closer to a solution, - though there is no proof that an efficient solution is impossible.</P> -<H3><A name="RSA.auth">RSA authentication</A></H3> -<P>The<A href="#RSA"> RSA</A> algorithm (named for its inventors -- - Rivest, Shamir and Adleman) is a very widely used<A href="glossary.html#"> - public key</A> cryptographic technique. It is used in IPsec as one - method of authenticating gateways for Diffie-Hellman key negotiation.</P> -<H2><A name="structure">Structure of IPsec</A></H2> -<P>There are three protocols used in an IPsec implementation:</P> -<DL> -<DT>ESP, Encapsulating Security Payload</DT> -<DD>Encrypts and/or authenticates data</DD> -<DT>AH, Authentication Header</DT> -<DD>Provides a packet authentication service</DD> -<DT>IKE, Internet Key Exchange</DT> -<DD>Negotiates connection parameters, including keys, for the other two</DD> -</DL> -<P>The term "IPsec" is slightly ambiguous. In some contexts, it includes - all three of the above but in other contexts it refers only to AH and - ESP.</P> -<H3><A name="IKE.ipsec">IKE (Internet Key Exchange)</A></H3> -<P>The IKE protocol sets up IPsec (ESP or AH) connections after - negotiating appropriate parameters (algorithms to be used, keys, - connection lifetimes) for them. This is done by exchanging packets on - UDP port 500 between the two gateways.</P> -<P>IKE (RFC 2409) was the outcome of a long, complex process in which - quite a number of protocols were proposed and debated. Oversimplifying - mildly, IKE combines:</P> -<DL> -<DT>ISAKMP (RFC 2408)</DT> -<DD>The<STRONG> I</STRONG>nternet<STRONG> S</STRONG>ecurity<STRONG> A</STRONG> -ssociation and<STRONG> K</STRONG>ey<STRONG> M</STRONG>anagement<STRONG> - P</STRONG>rotocol manages negotiation of connections and defines<A href="#SA"> - SA</A>s (Security Associations) as a means of describing connection - properties.</DD> -<DT>IPsec DOI for ISAKMP (RFC 2407)</DT> -<DD>A<STRONG> D</STRONG>omain<STRONG> O</STRONG>f<STRONG> I</STRONG> -nterpretation fills in the details necessary to turn the rather abstract - ISAKMP protocol into a more tightly specified protocol, so it becomes - applicable in a particular domain.</DD> -<DT>Oakley key determination protocol (RFC 2412)</DT> -<DD>Oakley creates keys using the<A href="#DH"> Diffie-Hellman</A> key - agreement protocol.</DD> -</DL> -<P>For all the details, you would need to read the four<A href="rfc.html"> - RFCs</A> just mentioned (over 200 pages) and a number of others. We - give a summary below, but it is far from complete.</P> -<H4><A name="phases">Phases of IKE</A></H4> -<P>IKE negotiations have two phases.</P> -<DL> -<DT>Phase one</DT> -<DD>The two gateways negotiate and set up a two-way ISAKMP SA which they - can then use to handle phase two negotiations. One such SA between a - pair of gateways can handle negotiations for multiple tunnels.</DD> -<DT>Phase two</DT> -<DD>Using the ISAKMP SA, the gateways negotiate IPsec (ESP and/or AH) - SAs as required. IPsec SAs are unidirectional (a different key is used - in each direction) and are always negotiated in pairs to handle two-way - traffic. There may be more than one pair defined between two gateways.</DD> -</DL> -<P>Both of these phases use the UDP protocol and port 500 for their - negotiations.</P> -<P>After both IKE phases are complete, you have IPsec SAs to carry your - encrypted data. These use the ESP or AH protocols. These protocols do - not have ports. Ports apply only to UDP or TCP.</P> -<P>The IKE protocol is designed to be extremely flexible. Among the - things that can be negotiated (separately for each SA) are:</P> -<UL> -<LI>SA lifetime before rekeying</LI> -<LI>encryption algorithm used. We currently support only<A href="#3DES"> - triple DES</A>. Single DES is<A href="#desnotsecure"> insecure</A>. The - RFCs say you MUST do DES, SHOULD do 3DES and MAY do various others. We - do not do any of the others.</LI> -<LI>authentication algorithms. We support<A href="#MD5"> MD5</A> and<A href="#SHA"> - SHA</A>. These are the two the RFCs require.</LI> -<LI>choice of group for<A href="#DH"> Diffie-Hellman</A> key agreement. - We currently support Groups 2 and 5 (which are defined modulo primes of - various lengths) and do not support Group 1 (defined modulo a shorter - prime, and therefore cryptographically weak) or groups 3 and 4 (defined - using elliptic curves). The RFCs require only Group 1.</LI> -</UL> -<P>The protocol also allows implementations to add their own encryption - algorithms, authentication algorithms or Diffie-Hellman groups. We do - not support any such extensions, but there are some<A href="#patch"> - patches</A> that do.</P> -<P>There are a number of complications:</P> -<UL> -<LI>The gateways must be able to authenticate each other's identities - before they can create a secure connection. This host authentication is - part of phase one negotiations, and is a required prerequisite for - packet authentication used later. Host authentication can be done in a - variety of ways. Those supported by FreeS/WAN are discussed in our<A href="#auto-auth"> - advanced configuration</A> document.</LI> -<LI>Phase one can be done in two ways. -<UL> -<LI>Main Mode is required by the RFCs and supported in FreeS/WAN. It - uses a 6-packet exzchange.</LI> -<LI>Aggressive Mode is somewhat faster (only 3 packets) but reveals more - to an eavesdropper. This is optional in the RFCs, not currently - supported by FreeS/WAN, and not likely to be.</LI> -</UL> -</LI> -<LI>A new group exchange may take place after phase one but before phase - two, defining an additional group for use in the<A href="#DH"> - Diffie-Hellman</A> key agreement part of phase two. FreeS/WAN does not - currently support this.</LI> -<LI>Phase two always uses Quick Mode, but there are two variants of - that: -<UL> -<LI>One variant provides<A href="#PFS"> Perfect Forward Secrecy (PFS)</A> -. An attacker that obtains your long-term host authentication key does - not immediately get any of your short-term packet encryption of packet - authentication keys. He must conduct another successful attack each - time you rekey to get the short-term keys. Having some short-term keys - does not help him learn others. In particular, breaking your system - today does not let him read messages he archived yestarday, assuming - you've changed short-term keys in the meanwhile. We enable PFS as the - default.</LI> -<LI>The other variant disables PFS and is therefore slightly faster. We - do not recommend this since it is less secure, but FreeS/WAN does - support it. You can enable it with a<VAR> pfs=no</VAR> statement in<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A>.</LI> -<LI>The protocol provides no way to negotiate which variant will be - used. If one gateway is set for PFS and the other is not, the - negotiation fails. This has proved a fairly common source of - interoperation problems.</LI> -</UL> -</LI> -<LI>Several types of notification message may be sent by either side - during either phase, or later. FreeS/WAN does not currently support - these, but they are a likely addition in future releases.</LI> -<LI>There is a commit flag which may optionally be set on some messages. - The<A href="http://www.lounge.org/ike_doi_errata.html"> errata</A> page - for the RFCs includes two changes related to this, one to clarify the - description of its use and one to block a<A href="#DOS"> denial of - service</A> attack which uses it. We currently do not implement this - feature.</LI> -</UL> -<P>These complications can of course lead to problems, particularly when - two different implementations attempt to interoperate. For example, we - have seen problems such as:</P> -<UL> -<LI>Some implementations (often products crippled by<A href="#exlaw"> - export laws</A>) have the insecure DES algorithm as their only - supported encryption method. Other parts of our documentation discuss - the<A href="#desnotsecure"> reasons we do not implement single DES</A>, - and<A href="interop.html#noDES"> how to cope with crippled products</A> -.</LI> -<LI>Windows 2000 IPsec tries to negotiate using Aggressive Mode, which - we don't support. Later on, it uses the commit bit, which we also don't - support.</LI> -<LI>Various implementations disable PFS by default, and therefore will - not talk to FreeS/WAN until you either turn on PFS on their end or turn - it off in FreeS/WAN with a<VAR> pfs=no</VAR> entry in the connection - description.</LI> -<LI>FreeS/WAN's interaction with PGPnet is complicated by their use of - notification messages we do not yet support.</LI> -</UL> -<P>Despite this, we do interoperate successfully with many - implementations, including both Windows 2000 and PGPnet. Details are in - our<A href="interop.html"> interoperability</A> document.</P> -<H4><A name="sequence">Sequence of messages in IKE</A></H4> -<P>Each phase (see<A href="#phases"> previous section</A>)of IKE - involves a series of messages. In Pluto error messages, these are - abbreviated using:</P> -<DL> -<DT>M</DT> -<DD><STRONG>M</STRONG>ain mode, settting up the keying channel (ISAKMP - SA)</DD> -<DT>Q</DT> -<DD><STRONG>Q</STRONG>uick mode, setting up the data channel (IPsec SA)</DD> -<DT>I</DT> -<DD><STRONG>I</STRONG>nitiator, the machine that starts the negotiation</DD> -<DT>R</DT> -<DD><STRONG>R</STRONG>esponder</DD> -</DL> -<P>For example, the six messages of a main mode negotiation, in - sequence, are labelled:</P> -<PRE> MI1 ----------> - <---------- MR1 - MI2 ----------> - <---------- MR2 - MI3 ----------> - <---------- MR3</PRE> -<H4><A name="struct.exchange">Structure of IKE messages</A></H4> -<P>Here is our Pluto developer explaining some of this on the mailing - list:</P> -<PRE>When one IKE system (for example, Pluto) is negotiating with another -to create an SA, the Initiator proposes a bunch of choices and the -Responder replies with one that it has selected. - -The structure of the choices is fairly complicated. An SA payload -contains a list of lists of "Proposals". The outer list is a set of -choices: the selection must be from one element of this list. - -Each of these elements is a list of Proposals. A selection must be -made from each of the elements of the inner list. In other words, -*all* of them apply (that is how, for example, both AH and ESP can -apply at once). - -Within each of these Proposals is a list of Transforms. For each -Proposal selected, one Transform must be selected (in other words, -each Proposal provides a choice of Transforms). - -Each Transform is made up of a list of Attributes describing, well, -attributes. Such as lifetime of the SA. Such as algorithm to be -used. All the Attributes apply to a Transform. - -You will have noticed a pattern here: layers alternate between being -disjunctions ("or") and conjunctions ("and"). - -For Phase 1 / Main Mode (negotiating an ISAKMP SA), this structure is -cut back. There must be exactly one Proposal. So this degenerates to -a list of Transforms, one of which must be chosen.</PRE> -<H3><A name="services">IPsec Services, AH and ESP</A></H3> -<P>IPsec offers two services,<A href="#authentication"> authentication</A> - and<A href="#encryption"> encryption</A>. These can be used separately - but are often used together.</P> -<DL> -<DT>Authentication</DT> -<DD>Packet-level authentication allows you to be confident that a packet - came from a particular machine and that its contents were not altered - en route to you. No attempt is made to conceal or protect the contents, - only to assure their integrity. Packet authentication can be provided - separately using an<A href="#AH"> Authentication Header</A>, described - just below, or it can be included as part of the<A href="#ESP"> ESP</A> - (Encapsulated Security Payload) service, described in the following - section. That service offers encryption as well as authentication. In - either case, the<A href="#HMAC"> HMAC</A> construct is used as the - authentication mechanism. -<P>There is a separate authentication operation at the IKE level, in - which each gateway authenticates the other. This can be done in a - variety of ways.</P> -</DD> -<DT>Encryption</DT> -<DD>Encryption allows you to conceal the contents of a message from - eavesdroppers. -<P>In IPsec this is done using a<A href="#block"> block cipher</A> - (normally<A href="#3DES"> Triple DES</A> for Linux). In the most used - setup, keys are automatically negotiated, and periodically - re-negotiated, using the<A href="#IKE"> IKE</A> (Internet Key Exchange) - protocol. In Linux FreeS/WAN this is handled by the Pluto Daemon.</P> -<P>The IPsec protocol offering encryption is<A href="#ESP"> ESP</A>, - Encapsulated Security Payload. It can also include a packet - authentication service.</P> -</DD> -</DL> -<P>Note that<STRONG> encryption should always be used with some packet - authentication service</STRONG>. Unauthenticated encryption is - vulnerable to<A href="#middle"> man-in-the-middle attacks</A>. Also - note that encryption does not prevent<A href="#traffic"> traffic - analysis</A>.</P> -<H3><A name="AH.ipsec">The Authentication Header (AH)</A></H3> -<P>Packet authentication can be provided separately from encryption by - adding an authentication header (AH) after the IP header but before the - other headers on the packet. This is the subject of this section. - Details are in RFC 2402.</P> -<P>Each of the several headers on a packet header contains a "next - protocol" field telling the system what header to look for next. IP - headers generally have either TCP or UDP in this field. When IPsec - authentication is used, the packet IP header has AH in this field, - saying that an Authentication Header comes next. The AH header then has - the next header type -- usually TCP, UDP or encapsulated IP.</P> -<P>IPsec packet authentication can be added in transport mode, as a - modification of standard IP transport. This is shown in this diagram - from the RFC:</P> -<PRE> BEFORE APPLYING AH - ---------------------------- - IPv4 |orig IP hdr | | | - |(any options)| TCP | Data | - ---------------------------- - - AFTER APPLYING AH - --------------------------------- - IPv4 |orig IP hdr | | | | - |(any options)| AH | TCP | Data | - --------------------------------- - || - except for mutable fields</PRE> -<P>Athentication can also be used in tunnel mode, encapsulating the - underlying IP packet beneath AH and an additional IP header.</P> -<PRE> || -IPv4 | new IP hdr* | | orig IP hdr* | | | - |(any options)| AH | (any options) |TCP | Data | - ------------------------------------------------ - || - | in the new IP hdr |</PRE> -<P>This would normally be used in a gateway-to-gateway tunnel. The - receiving gateway then strips the outer IP header and the AH header and - forwards the inner IP packet.</P> -<P>The mutable fields referred to are things like the time-to-live field - in the IP header. These cannot be included in authentication - calculations because they change as the packet travels.</P> -<H4><A name="keyed">Keyed MD5 and Keyed SHA</A></H4> -<P>The actual authentication data in the header is typically 96 bits and - depends both on a secret shared between sender and receiver and on - every byte of the data being authenticated. The technique used is<A href="#HMAC"> - HMAC</A>, defined in RFC 2104.</P> -<P>The algorithms involved are the<A href="#MD5"> MD5</A> Message Digest - Algorithm or<A href="#SHA"> SHA</A>, the Secure Hash Algorithm. For - details on their use in this application, see RFCs 2403 and 2404 - respectively.</P> -<P>For descriptions of the algorithms themselves, see RFC 1321 for MD5 - and<A href="#FIPS"> FIPS</A> (Federal Information Processing Standard) - number 186 from<A href="#NIST"> NIST</A>, the US National Institute of - Standards and Technology for SHA.<A href="#schneier"><CITE> Applied - Cryptography</CITE></A> covers both in some detail, MD5 starting on - page 436 and SHA on 442.</P> -<P>These algorithms are intended to make it nearly impossible for anyone - to alter the authenticated data in transit. The sender calculates a - digest or hash value from that data and includes the result in the - authentication header. The recipient does the same calculation and - compares results. For unchanged data, the results will be identical. - The hash algorithms are designed to make it extremely difficult to - change the data in any way and still get the correct hash.</P> -<P>Since the shared secret key is also used in both calculations, an - interceptor cannot simply alter the authenticated data and change the - hash value to match. Without the key, he or she (or even the dreaded - They) cannot produce a usable hash.</P> -<H4><A name="sequence">Sequence numbers</A></H4> -<P>The authentication header includes a sequence number field which the - sender is required to increment for each packet. The receiver can - ignore it or use it to check that packets are indeed arriving in the - expected sequence.</P> -<P>This provides partial protection against<A href="#replay"> replay - attacks</A> in which an attacker resends intercepted packets in an - effort to confuse or subvert the receiver. Complete protection is not - possible since it is necessary to handle legitmate packets which are - lost, duplicated, or delivered out of order, but use of sequence - numbers makes the attack much more difficult.</P> -<P>The RFCs require that sequence numbers never cycle, that a new key - always be negotiated before the sequence number reaches 2^32-1. This - protects both against replays attacks using packets from a previous - cyclce and against<A href="#birthday"> birthday attacks</A> on the the - packet authentication algorithm.</P> -<P>In Linux FreeS/WAN, the sequence number is ignored for manually keyed - connections and checked for automatically keyed ones. In manual mode, - there is no way to negotiate a new key, or to recover from a sequence - number problem, so we don't use sequence numbers.</P> -<H3><A name="ESP.ipsec">Encapsulated Security Payload (ESP)</A></H3> -<P>The ESP protocol is defined in RFC 2406. It provides one or both of - encryption and packet authentication. It may be used with or without AH - packet authentication.</P> -<P>Note that<STRONG> some form of packet authentication should<EM> - always</EM> be used whenever data is encrypted</STRONG>. Without - authentication, the encryption is vulnerable to active attacks which - may allow an enemy to break the encryption. ESP should<STRONG> always</STRONG> - either include its own authentication or be used with AH - authentication.</P> -<P>The RFCs require support for only two mandatory encryption algorithms - --<A href="#DES"> DES</A>, and null encryption -- and for two - authentication methods -- keyed MD5 and keyed SHA. Implementers may - choose to support additional algorithms in either category.</P> -<P>The authentication algorithms are the same ones used in the IPsec<A href="#AH"> - authentication header</A>.</P> -<P>We do not implement single DES since<A href="#desnotsecure"> DES is - insecure</A>. Instead we provide<A href="#3DES"> triple DES or 3DES</A> -. This is currently the only encryption algorithm supported.</P> -<P>We do not implement null encryption since it is obviously insecure.</P> -<H2><A name="modes">IPsec modes</A></H2> -<P>IPsec can connect in two modes. Transport mode is a host-to-host - connection involving only two machines. In tunnel mode, the IPsec - machines act as gateways and trafiic for any number of client machines - may be carried.</P> -<H3><A name="tunnel.ipsec">Tunnel mode</A></H3> -<P>Security gateways are required to support tunnel mode connections. In - this mode the gateways provide tunnels for use by client machines - behind the gateways. The client machines need not do any IPsec - processing; all they have to do is route things to gateways.</P> -<H3><A name="transport.ipsec">Transport mode</A></H3> -<P>Host machines (as opposed to security gateways) with IPsec - implementations must also support transport mode. In this mode, the - host does its own IPsec processing and routes some packets via IPsec.</P> -<H2><A name="parts">FreeS/WAN parts</A></H2> -<H3><A name="KLIPS.ipsec">KLIPS: Kernel IPsec Support</A></H3> -<P>KLIPS is<STRONG> K</STRONG>erne<STRONG>L</STRONG><STRONG> IP</STRONG> -SEC<STRONG> S</STRONG>upport, the modifications necessary to support - IPsec within the Linux kernel. KILPS does all the actual IPsec - packet-handling, including</P> -<UL> -<LI>encryption</LI> -<LI>packet authentication calculations</LI> -<LI>creation of ESP and AH headers for outgoing packets</LI> -<LI>interpretation of those headers on incoming packets</LI> -</UL> -<P>KLIPS also checks all non-IPsec packets to ensure they are not - bypassing IPsec security policies.</P> -<H3><A name="Pluto.ipsec">The Pluto daemon</A></H3> -<P><A href="manpage.d/ipsec_pluto.8.html">Pluto(8)</A> is a daemon which - implements the IKE protocol. It</P> -<UL> -<LI>handles all the Phase one ISAKMP SAs</LI> -<LI>performs host authentication and negotiates with other gateways</LI> -<LI>creates IPsec SAs and passes the data required to run them to KLIPS</LI> -<LI>adjust routing and firewall setup to meet IPsec requirements. See - our<A href="firewall.html"> IPsec and firewalling</A> document for - details.</LI> -</UL> -<P>Pluto is controlled mainly by the<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A> configuration file.</P> -<H3><A name="command">The ipsec(8) command</A></H3> -<P>The<A href="manpage.d/ipsec.8.html"> ipsec(8)</A> command is a front - end shellscript that allows control over IPsec activity.</P> -<H3><A name="ipsec.conf">Linux FreeS/WAN configuration file</A></H3> -<P>The configuration file for Linux FreeS/WAN is</P> -<PRE> /etc/ipsec.conf</PRE> -<P>For details see the<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A> manual page .</P> -<H2><A name="key">Key management</A></H2> -<P>There are several ways IPsec can manage keys. Not all are implemented - in Linux FreeS/WAN.</P> -<H3><A name="current">Currently Implemented Methods</A></H3> -<H4><A name="manual">Manual keying</A></H4> -<P>IPsec allows keys to be manually set. In Linux FreeS/WAN, such keys - are stored with the connection definitions in /etc/ipsec.conf.</P> -<P><A href="#manual">Manual keying</A> is useful for debugging since it - allows you to test the<A href="#KLIPS"> KLIPS</A> kernel IPsec code - without the<A href="#Pluto"> Pluto</A> daemon doing key negotiation.</P> -<P>In general, however, automatic keying is preferred because it is more - secure.</P> -<H4><A name="auto">Automatic keying</A></H4> -<P>In automatic keying, the<A href="#Pluto"> Pluto</A> daemon negotiates - keys using the<A href="#IKE"> IKE</A> Internet Key Exchange protocol. - Connections are automatically re-keyed periodically.</P> -<P>This is considerably more secure than manual keying. In either case - an attacker who acquires a key can read every message encrypted with - that key, but automatic keys can be changed every few hours or even - every few minutes without breaking the connection or requiring - intervention by the system administrators. Manual keys can only be - changed manually; you need to shut down the connection and have the two - admins make changes. Moreover, they have to communicate the new keys - securely, perhaps with<A href="#PGP"> PGP</A> or<A href="#ssh"> SSH</A> -. This may be possible in some cases, but as a general solution it is - expensive, bothersome and unreliable. Far better to let<A href="#Pluto"> - Pluto</A> handle these chores; no doubt the administrators have enough - to do.</P> -<P>Also, automatic keying is inherently more secure against an attacker - who manages to subvert your gateway system. If manual keying is in use - and an adversary acquires root privilege on your gateway, he reads your - keys from /etc/ipsec.conf and then reads all messages encrypted with - those keys.</P> -<P>If automatic keying is used, an adversary with the same privileges - can read /etc/ipsec.secrets, but this does not contain any keys, only - the secrets used to authenticate key exchanges. Having an adversary - able to authenticate your key exchanges need not worry you overmuch. - Just having the secrets does not give him any keys. You are still - secure against<A href="#passive"> passive</A> attacks. This property of - automatic keying is called<A href="#PFS"> perfect forward secrecy</A>, - abbreviated PFS.</P> -<P>Unfortunately, having the secrets does allow an<A href="#active"> - active attack</A>, specifically a<A href="#middle"> man-in-the-middle</A> - attack. Losing these secrets to an attacker may not be quite as - disastrous as losing the actual keys, but it is<EM> still a serious - security breach</EM>. These secrets should be guarded as carefully as - keys.</P> -<H3><A name="notyet">Methods not yet implemented</A></H3> -<H4><A name="noauth">Unauthenticated key exchange</A></H4> -<P>It would be possible to exchange keys without authenticating the - players. This would support<A href="#carpediem"> opportunistic - encryption</A> -- allowing any two systems to encrypt their - communications without requiring a shared PKI or a previously - negotiated secret -- and would be secure against<A href="#passive"> - passive attacks</A>. It would, however, be highly vulnerable to active<A -href="#middle"> man-in-the-middle</A> attacks. RFC 2408 therefore - specifies that all<A href="#ISAKMP"> ISAKMP</A> key management - interactions<EM> must</EM> be authenticated.</P> -<P>There is room for debate here. Should we provide immediate security - against<A href="#passive"> passive attacks</A> and encourage widespread - use of encryption, at the expense of risking the more difficult<A href="#active"> - active attacks</A>? Or should we wait until we can implement a solution - that can both be widespread and offer security against active attacks?</P> -<P>So far, we have chosen the second course, complying with the RFCs and - waiting for secure DNS (see<A href="#DNS"> below</A>) so that we can do<A -href="#carpediem"> opportunistic encryption</A> right.</P> -<H4><A name="DNS">Key exchange using DNS</A></H4> -<P>The IPsec RFCs allow key exchange based on authentication services - provided by<A href="#SDNS"> Secure DNS</A>. Once Secure DNS service - becomes widely available, we expect to make this the<EM> primary key - management method for Linux FreeS/WAN</EM>. It is the best way we know - of to support<A href="#carpediem"> opportunistic encryption</A>, - allowing two systems without a common PKI or previous negotiation to - secure their communication.</P> -<P>We currently have code to acquire RSA keys from DNS but do not yet - have code to validate Secure DNS signatures.</P> -<H4><A name="PKI">Key exchange using a PKI</A></H4> -<P>The IPsec RFCs allow key exchange based on authentication services - provided by a<A href="#PKI"> PKI</A> or Public Key Infrastructure. With - many vendors selling such products and many large organisations - building these infrastructures, this will clearly be an important - application of IPsec and one Linux FreeS/WAN will eventually support.</P> -<P>On the other hand, this is not as high a priority for Linux FreeS/WAN - as solutions based on<A href="#SDNS"> secure DNS</A>. We do not expect - any PKI to become as universal as DNS.</P> -<P>Some<A href="#patch"> patches</A> to handle authentication with X.509 - certificates, which most PKIs use, are available.</P> -<H4><A name="photuris">Photuris</A></H4> -<P><A href="#photuris">Photuris</A> is another key management protocol, - an alternative to IKE and ISAKMP, described in RFCs 2522 and 2523 which - are labelled "experimental". Adding Photuris support to Linux FreeS/WAN - might be a good project for a volunteer. The likely starting point - would be the OpenBSD photurisd code.</P> -<H4><A name="skip">SKIP</A></H4> -<P><A href="#SKIP">SKIP</A> is yet another key management protocol, - developed by Sun. At one point it was fairly widely used, but it now - seems moribund, displaced by IKE. Sun now (as of Solaris 8.0) ship an - IPsec implementation using IKE. We have no plans to implement SKIP. If - a user were to implement it, we would almost certainly not want to add - the code to our distribution.</P> -<HR> -<H1><A name="lists">Mailing lists and newsgroups</A></H1> -<H2><A name="list.fs">Mailing lists about FreeS/WAN</A></H2> -<H3><A name="projlist">The project mailing lists</A></H3> -<P>The Linux FreeS/WAN project has several email lists for user support, - bug reports and software development discussions.</P> -<P>We had a single list on clinet.fi for several years (Thanks, folks!), - then one list on freeswan.org, but now we've split into several lists:</P> -<DL> -<DT><A href="mailto:users-request@lists.freeswan.org?body=subscribe"> -users</A></DT> -<DD> -<UL> -<LI>The general list for discussing use of the software</LI> -<LI>The place for seeking<STRONG> help with problems</STRONG> (but - please check the<A href="faq.html"> FAQ</A> first).</LI> -<LI>Anyone can post.</LI> -</UL> -</DD> -<DT><A href="mailto:bugs-request@lists.freeswan.org?body=subscribe">bugs</A> -</DT> -<DD> -<UL> -<LI>For<STRONG> bug reports</STRONG>.</LI> -<LI>If you are not certain what is going on -- could be a bug, a - configuration error, a network problem, ... -- please post to the users - list instead.</LI> -<LI>Anyone can post.</LI> -</UL> -</DD> -<DT><A href="mailto:design-request@lists.freeswan.org?body=subscribe"> -design</A></DT> -<DD> -<UL> -<LI><STRONG>Design discussions</STRONG>, for people working on FreeS/WAN - development or others with an interest in design and security issues.</LI> -<LI>It would be a good idea to read the existing design papers (see this<A -href="#applied"> list</A>) before posting.</LI> -<LI>Anyone can post.</LI> -</UL> -</DD> -<DT><A href="mailto:announce-request@lists.freeswan.org?body=subscribe"> -announce</A></DT> -<DD> -<UL> -<LI>A<STRONG> low-traffic</STRONG> list.</LI> -<LI><STRONG>Announcements</STRONG> about FreeS/WAN and related software.</LI> -<LI>All posts here are also sent to the users list. You need not - subscribe to both.</LI> -<LI>Only the FreeS/WAN team can post.</LI> -<LI>If you have something you feel should go on this list, send it to<VAR> - announce-admin@lists.freeswan.org</VAR>. Unless it is obvious, please - include a short note explaining why we should post it.</LI> -</UL> -</DD> -<DT><A href="mailto:briefs-request@lists.freeswan.org?body=subscribe"> -briefs</A></DT> -<DD> -<UL> -<LI>A<STRONG> low-traffic</STRONG> list.</LI> -<LI><STRONG>Weekly summaries</STRONG> of activity on the users list.</LI> -<LI>All posts here are also sent to the users list. You need not - subscribe to both.</LI> -<LI>Only the FreeS/WAN team can post.</LI> -</UL> -</DD> -</DL> -<P>To subscribe to any of these, you can:</P> -<UL> -<LI>just follow the links above</LI> -<LI>use our<A href="http://www.freeswan.org/mail.html"> web interface</A> -</LI> -<LI>send mail to<VAR> listname</VAR>-request@lists.freeswan.org with a - one-line message body "subscribe"</LI> -</UL> -<P>Archives of these lists are available via the<A href="http://www.freeswan.org/mail.html"> - web interface</A>.</P> -<H4><A name="which.list">Which list should I use?</A></H4> -<P>For most questions, please check the<A href="faq.html"> FAQ</A> - first, and if that does not have an answer, ask on the users list. "My - configuration doesn't work." does not belong on the bugs list, and "Can - FreeS/WAN do such-and-such" or "How do I configure it to..." do not - belong in design discussions.</P> -<P>Cross-posting the same message to two or more of these lists is - discouraged. Quite a few people read more than one list and getting - multiple copies is annoying.</P> -<H4><A name="policy.list">List policies</A></H4> -<P><STRONG>US citizens or residents are asked not to post code to the - lists, not even one-line bug fixes</STRONG>. The project cannot accept - code which might entangle it in US<A href="#exlaw"> export restrictions</A> -.</P> -<P>Non-subscribers can post to some of these lists. This is necessary; - someone working on a gateway install who encounters a problem may not - have access to a subscribed account.</P> -<P>Some spam turns up on these lists from time to time. For discussion - of why we do not attempt to filter it, see the<A href="#spam"> FAQ</A>. - Please do not clutter the lists with complaints about this.</P> -<H3><A name="archive">Archives of the lists</A></H3> -<P>Searchable archives of the old single list have existed for some - time. At time of writing, it is not yet clear how they will change for - the new multi-list structure.</P> -<UL> -<LI><A href="http://www.sandelman.ottawa.on.ca/linux-ipsec">Canada</A></LI> -<LI><A href="http://www.nexial.com">Holland</A></LI> -</UL> -<P>Note that these use different search engines. Try both.</P> -<P>Archives of the new lists are available via the<A href="http://www.freeswan.org/mail.html"> - web interface</A>.</P> -<H2><A name="indexes">Indexes of mailing lists</A></H2> -<P><A href="http://paml.net/">PAML</A> is the standard reference for<STRONG> - P</STRONG>ublicly<STRONG> A</STRONG>ccessible<STRONG> M</STRONG>ailing<STRONG> - L</STRONG>ists. When we last checked, it had over 7500 lists on an - amazing variety of topics. It also has FAQ information and a search - engine.</P> -<P>There is an index of<A href="http://oslab.snu.ac.kr/~djshin/linux/mail-list/index.shtml"> - Linux mailing lists</A> available.</P> -<P>A list of<A href="http://xforce.iss.net/maillists/otherlists.php"> - computer security mailing lists</A>, with descriptions.</P> -<H2><A name="otherlists">Lists for related software and topics</A></H2> -<P>Most links in this section point to subscription addresses for the - various lists. Send the one-line message "subscribe<VAR> list_name</VAR> -" to subscribe to any of them.</P> -<H3><A NAME="28_3_1">Products that include FreeS/WAN</A></H3> -<P>Our introduction document gives a<A href="#products"> list of - products that include FreeS/WAN</A>. If you have, or are considering, - one of those, check the supplier's web site for information on mailing - lists for their users.</P> -<H3><A name="linux.lists">Linux mailing lists</A></H3> -<UL> -<LI><A href="mailto:majordomo@vger.kernel.org"> -linux-admin@vger.kernel.org</A>, for Linux system administrators</LI> -<LI><A href="mailto:netfilter-request@lists.samba.org"> -netfilter@lists.samba.org</A>, about Netfilter, which replaces IPchains - in kernels 2.3.15 and later</LI> -<LI><A href="mailto:security-audit-request@ferret.lmh.ox.ac.uk"> -security-audit@ferret.lmh.ox.ac.uk</A>, for people working on security - audits of various Linux programs</LI> -<LI><A href="mailto:securedistros-request@humbolt.geo.uu.nl"> -securedistros@humbolt.geo.uu.nl</A>, for discussion of issues common to - all the half dozen projects working on secure Linux distributions.</LI> -</UL> -<P>Each of the scure distribution projects also has its own web site and - mailing list. Some of the sites are:</P> -<UL> -<LI><A href="http://bastille-linux.org/">Bastille Linux</A> scripts to - harden Redhat, e.g. by changing permissions and modifying inialisation - scripts</LI> -<LI><A href="http://immunix.org/">Immunix</A> take a different approach, - using a modified compiler to build kernel and utilities with better - resistance to various types of overflow and exploit</LI> -<LI>the<A href="#NSA"> NSA</A> have contractors working on a<A href="#SElinux"> - Security Enhanced Linux</A>, primarily adding stronger access control - mechanisms. You can download the current version (which interestingly - is under GPL and not export resrtricted) or subscribe to the mailing - list from the<A href="http://www.nsa.gov/selinux"> project web page</A> -.</LI> -</UL> -<H3><A name="ietf">Lists for IETF working groups</A></H3> -<P>Each<A href="#ietf"> IETF</A> working group has an associated mailing - list where much of the work takes place.</P> -<UL> -<LI><A href="mailto:majordomo@lists.tislabs.com">ipsec@lists.tislabs.com</A> -, the IPsec<A href="http://www.ietf.org/html.charters/ipsec-charter.html"> - working group</A>. This is where the protocols are discussed, new - drafts announced, and so on. By now, the IPsec working group is winding - down since the work is essentially complete. A<A href="http://www.sandelman.ottawa.on.ca/ipsec/"> - list archive</A> is available.</LI> -<LI><A href="mailto:ipsec-policy-request@vpnc.org">IPsec policy</A> - list, and its<A href="http://www.vpnc.org/ipsec-policy/"> archive</A></LI> -<LI><A href="mailto:ietf-ipsra-request@vpnc.org">IP secure remote access</A> - list, and its<A href="http://www.vpnc.org/ietf-ipsra/mail-archive/"> - archive</A></LI> -</UL> -<H3><A name="other">Other mailing lists</A></H3> -<UL> -<LI><A href="mailto:ipc-announce-request@privacy.org"> -ipc-announce@privacy.org</A> a low-traffic list with announcements of - developments in privacy, encryption and online civil rights</LI> -<LI>a VPN mailing list's<A href="http://kubarb.phsx.ukans.edu/~tbird/vpn.html"> - home page</A></LI> -</UL> -<H2><A name="newsgroups">Usenet newsgroups</A></H2> -<UL> -<LI>sci.crypt</LI> -<LI>sci.crypt.research</LI> -<LI>comp.dcom.vpn</LI> -<LI>talk.politics.crypto</LI> -</UL> -<HR> -<H1><A name="weblink">Web links</A></H1> -<H2><A name="freeswan">The Linux FreeS/WAN Project</A></H2> -<P>The main project web site is<A href="http://www.freeswan.org/"> - www.freeswan.org</A>.</P> -<P>Links to other project-related<A href="#sites"> sites</A> are - provided in our introduction section.</P> -<H3><A name="patch">Add-ons and patches for FreeS/WAN</A></H3> -<P>Some user-contributed patches have been integrated into the FreeS/WAN - distribution. For a variety of reasons, those listed below have not.</P> -<P>Note that not all patches are a good idea.</P> -<UL> -<LI>There are a number of "features" of IPsec which we do not implement - because they reduce security. See this<A href="#dropped"> discussion</A> -. We do not recommend using patches that implement these. One example is - aggressive mode.</LI> -<LI>We do not recommend adding "features" of any sort unless they are - clearly necessary, or at least have clear benefits. For example, - FreeS/WAN would not become more secure if it offerred a choice of 14 - ciphers. If even one was flawed, it would certainly become less secure - for anyone using that cipher. Even with 14 wonderful ciphers, it would - be harder to maintain and administer, hence more vulnerable to various - human errors.</LI> -</UL> -<P>This is not to say that patches are necessarily bad, only that using - them requires some deliberation. For example, there might be perfectly - good reasons to add a specific cipher in your application: perhaps GOST - to comply with government standards in Eastern Europe, or AES for - performance benefits.</P> -<H4><A NAME="29_1_1_1">Current patches</A></H4> -<P>Patches believed current::</P> -<UL> -<LI>patches for<A href="http://www.strongsec.com/freeswan/"> X.509 - certificate support</A>, also available from a<A href="http://www.twi.ch/~sna/strongsec/freeswan/"> - mirror site</A></LI> -<LI>patches to add<A href="http://www.irrigacion.gov.ar/juanjo/ipsec"> - AES and other ciphers</A>. There is preliminary data indicating AES - gives a substantial<A href="#perf.more"> performance gain</A>.</LI> -</UL> -<P>There is also one add-on that takes the form of a modified FreeS/WAN - distribution, rather than just patches to the standard distribution:</P> -<UL> -<LI><A href="http://www.ipv6.iabg.de/downloadframe/index.html">IPv6 - support</A></LI> -</UL> -<P>Before using any of the above,, check the<A href="mail.html"> mailing - lists</A> for news of newer versions and to see whether they have been - incorporated into more recent versions of FreeS/WAN.</P> -<H4><A NAME="29_1_1_2">Older patches</A></H4> -<UL> -<LI><A href="http://sources.colubris.com/en/projects/FreeSWAN/">hardware - acceleration</A></LI> -<LI>a<A href="http://tzukanov.narod.ru/"> series</A> of patches that -<UL> -<LI>provide GOST, a Russian gov't. standard cipher, in MMX assembler</LI> -<LI>add GOST to OpenSSL</LI> -<LI>add GOST to the International kernel patch</LI> -<LI>let FreeS/WAN use International kernel patch ciphers</LI> -</UL> -</LI> -<LI>Neil Dunbar's patches for<A href="ftp://hplose.hpl.hp.com/pub/nd/pluto-openssl.tar.gz"> - certificate support</A>, using code from<A href="http://www.openssl.org"> - Open SSL</A>.</LI> -<LI>Luc Lanthier's<A href="ftp://ftp.netwinder.org/users/f/firesoul/"> - patches</A> for<A href="#PKIX"> PKIX</A> support.</LI> -<LI><A href="ftp://ftp.heise.de/pub/ct/listings/9916-180.tgz">patches</A> - to add<A href="#Blowfish"> Blowfish</A>,<A href="#IDEA"> IDEA</A> and<A href="#CAST128"> - CAST-128</A> to FreeS/WAN</LI> -<LI>patches for FreeS/WAN 1.3, Pluto support for<A href="http://alcatraz.webcriminals.com/~bastiaan/ipsec/"> - external authentication</A>, for example with a smartcard or SKEYID.</LI> -<LI><A href="http://www.zengl.net/freeswan/download/">patches and - utilities</A> for using FreeS/WAN with PGPnet</LI> -<LI><A href="http://www.freelith.com/lithworks/crypto/freeswan_patch.htm"> -Blowfish encryption and Tiger hash</A></LI> -<LI><A href="http://www.cendio.se/~bellman/aggressive-pluto.snap.tar.gz"> -patches</A> for aggressive mode support</LI> -</UL> -<P>These patches are for older versions of FreeS/WAN and will likely not - work with the current version. Older versions of FreeS/WAN may be - available on some of the<A href="#sites"> distribution sites</A>, but - we recommend using the current release.</P> -<H4><A name="VPN.masq">VPN masquerade patches</A></H4> -<P>Finally, there are some patches to other code that may be useful with - FreeS/WAN:</P> -<UL> -<LI>a<A href="ftp://ftp.rubyriver.com/pub/jhardin/masquerade/ip_masq_vpn.html"> - patch</A> to make IPsec, PPTP and SSH VPNs work through a Linux - firewall with<A href="#masq"> IP masquerade</A>.</LI> -<LI><A href="http://www.linuxdoc.org/HOWTO/VPN-Masquerade-HOWTO.html"> -Linux VPN Masquerade HOWTO</A></LI> -</UL> -<P>Note that this is not required if the same machine does IPsec and - masquerading, only if you want a to locate your IPsec gateway on a - masqueraded network. See our<A href="#NAT"> firewalls</A> document for - discussion of why this is problematic.</P> -<P>At last report, this patch could not co-exist with FreeS/WAN on the - same machine.</P> -<H3><A name="dist">Distributions including FreeS/WAN</A></H3> -<P>The introductory section of our document set lists several<A href="#distwith"> - Linux distributions</A> which include FreeS/WAN.</P> -<H3><A name="used">Things FreeS/WAN uses or could use</A></H3> -<UL> -<LI><A href="http://openpgp.net/random">/dev/random</A> support page, - discussion of and code for the Linux<A href="#random"> random number - driver</A>. Out-of-date when we last checked (January 2000), but still - useful.</LI> -<LI>other programs related to random numbers: -<UL> -<LI><A href="http://www.mindrot.org/audio-entropyd.html">audio entropy - daemon</A> to gather noise from a sound card and feed it into - /dev/random</LI> -<LI>an<A href="http://www.lothar.com/tech/crypto/"> entropy-gathering - daemon</A></LI> -<LI>a driver for the random number generator in recent<A href="http://sourceforge.net/projects/gkernel/"> - Intel chipsets</A>. This driver is included as standard in 2.4 kernels.</LI> -</UL> -</LI> -<LI>a Linux<A href="http://www.marko.net/l2tp/"> L2TP Daemon</A> which - might be useful for communicating with Windows 2000 which builds L2TP - tunnels over its IPsec connections</LI> -<LI>to use opportunistic encryption, you need a recent version of<A href="#BIND"> - BIND</A>. You can get one from the<A href="http://www.isc.org"> - Internet Software Consortium</A> who maintain BIND.</LI> -</UL> -<H3><A name="alternatives">Other approaches to VPNs for Linux</A></H3> -<UL> -<LI>other Linux<A href="#linuxipsec"> IPsec implementations</A></LI> -<LI><A href="http://www.tik.ee.ethz.ch/~skip/">ENskip</A>, a free - implementation of Sun's<A href="#SKIP"> SKIP</A> protocol</LI> -<LI><A href="http://sunsite.auc.dk/vpnd/">vpnd</A>, a non-IPsec VPN - daemon for Linux which creates tunnels using<A href="#Blowfish"> - Blowfish</A> encryption</LI> -<LI><A href="http://www.winton.org.uk/zebedee/">Zebedee</A>, a simple - GPLd tunnel-building program with Linux and Win32 versions. The name is - from<STRONG> Z</STRONG>lib compression,<STRONG> B</STRONG>lowfish - encryption and<STRONG> D</STRONG>iffie-Hellman key exchange.</LI> -<LI>There are at least two PPTP implementations for Linux -<UL> -<LI>Moreton Bay's<A href="http://www.moretonbay.com/vpn/pptp.html"> - PoPToP</A></LI> -<LI><A href="http://cag.lcs.mit.edu/~cananian/Projects/PPTP/">PPTP-Linux</A> -</LI> -</UL> -</LI> -<LI><A href="http://sites.inka.de/sites/bigred/devel/cipe.html">CIPE</A> - (crypto IP encapsulation) project, using their own lightweight protocol - to encrypt between routers</LI> -<LI><A href="http://tinc.nl.linux.org/">tinc</A>, a VPN Daemon</LI> -</UL> -<P>There is a list of<A href="http://www.securityportal.com/lskb/10000000/kben10000005.html"> - Linux VPN</A> software in the<A href="http://www.securityportal.com/lskb/kben00000001.html"> - Linux Security Knowledge Base</A>.</P> -<H2><A name="ipsec.link">The IPsec Protocols</A></H2> -<H3><A name="general">General IPsec or VPN information</A></H3> -<UL> -<LI>The<A href="http://www.vpnc.org"> VPN Consortium</A> is a group for - vendors of IPsec products. Among other things, they have a good - collection of<A href="http://www.vpnc.org/white-papers.html"> IPsec - white papers</A>.</LI> -<LI>A VPN mailing list with a<A href="http://kubarb.phsx.ukans.edu/~tbird/vpn.html"> - home page</A>, a FAQ, some product comparisons, and many links.</LI> -<LI><A href="http://www.opus1.com/vpn/index.html">VPN pointer page</A></LI> -<LI>a<A href="http://www.epm.ornl.gov/~dunigan/vpn.html"> collection</A> - of VPN links, and some explanation</LI> -</UL> -<H3><A name="overview">IPsec overview documents or slide sets</A></H3> -<UL> -<LI>the FreeS/WAN<A href="ipsec.html"> document section</A> on these - protocols</LI> -</UL> -<H3><A name="otherlang">IPsec information in languages other than - English</A></H3> -<UL> -<LI><A href="http://www.imib.med.tu-dresden.de/imib/Internet/Literatur/ipsec-docu.html"> -German</A></LI> -<LI><A href="http://www.kame.net/index-j.html">Japanese</A></LI> -<LI>Feczak Szabolcs' thesis in<A href="http://feczo.koli.kando.hu/vpn/"> - Hungarian</A></LI> -<LI>Davide Cerri's thesis and some presentation slides<A href="http://www.linux.it/~davide/doc/"> - Italian</A></LI> -</UL> -<H3><A name="RFCs1">RFCs and other reference documents</A></H3> -<UL> -<LI><A href="rfc.html">Our document</A> listing the RFCs relevant to - Linux FreeS/WAN and giving various ways of obtaining both RFCs and - Internet Drafts.</LI> -<LI><A href="http://www.vpnc.org/vpn-standards.html">VPN Standards</A> - page maintained by<A href="#VPNC"> VPNC</A>. This covers both RFCs and - Drafts, and classifies them in a fairly helpful way.</LI> -<LI><A href="http://www.rfc-editor.org">RFC archive</A></LI> -<LI><A href="http://www.ietf.org/ids.by.wg/ipsec.html">Internet Drafts</A> - related to IPsec</LI> -<LI>US government<A href="http://www.itl.nist.gov/div897/pubs"> site</A> - with their<A href="#FIPS"> FIPS</A> standards</LI> -<LI>Archives of the ipsec@tis.com mailing list where discussion of - drafts takes place. -<UL> -<LI><A href="http://www.sandelman.ottawa.on.ca/ipsec">Eastern Canada</A></LI> -<LI><A href="http://www.vpnc.org/ietf-ipsec">California</A>.</LI> -</UL> -</LI> -</UL> -<H3><A name="analysis">Analysis and critiques of IPsec protocols</A></H3> -<UL> -<LI>Counterpane's<A href="http://www.counterpane.com/ipsec.pdf"> - evaluation</A> of the protocols</LI> -<LI>Simpson's<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/1999/06/msg00319.html"> - IKE Considered Dangerous</A> paper. Note that this is a link to an - archive of our mailing list. There are several replies in addition to - the paper itself.</LI> -<LI>Fate Labs<A href="http://www.fatelabs.com/loki-vpn.pdf"> Virual - Private Problems: the Broken Dream</A></LI> -<LI>Catherine Meadows' paper<CITE> Analysis of the Internet Key Exchange - Protocol Using the NRL Protocol Analyzer</CITE>, in<A href="http://chacs.nrl.navy.mil/publications/CHACS/1999/1999meadows-IEEE99.pdf"> - PDF</A> or<A href="http://chacs.nrl.navy.mil/publications/CHACS/1999/1999meadows-IEEE99.ps"> - Postscript</A>.</LI> -<LI>Perlman and Kaufmnan -<UL> -<LI><A href="http://snoopy.seas.smu.edu/ee8392_summer01/week7/perlman2.pdf"> -Key Exchange in IPsec</A></LI> -<LI>a newer<A href="http://sec.femto.org/wetice-2001/papers/radia-paper.pdf"> - PDF paper</A>,<CITE> Analysis of the IPsec Key Exchange Standard</CITE> -.</LI> -</UL> -</LI> -<LI>Bellovin's<A href="http://www.research.att.com/~smb/papers/index.html"> - papers</A> page including his: -<UL> -<LI><CITE>Security Problems in the TCP/IP Protocol Suite</CITE> (1989)</LI> -<LI><CITE>Problem Areas for the IP Security Protocols</CITE> (1996)</LI> -<LI><CITE>Probable Plaintext Cryptanalysis of the IP Security Protocols</CITE> - (1997)</LI> -</UL> -</LI> -<LI>An<A href="http://www.lounge.org/ike_doi_errata.html"> errata list</A> - for the IPsec RFCs.</LI> -</UL> -<H3><A name="IP.background">Background information on IP</A></H3> -<UL> -<LI>An<A href="http://ipprimer.windsorcs.com/"> IP tutorial</A> that - seems to be written mainly for Netware or Microsoft LAN admins entering - a new world</LI> -<LI><A href="http://www.iana.org">IANA</A>, Internet Assigned Numbers - Authority</LI> -<LI><A href="http://public.pacbell.net/dedicated/cidr.html">CIDR</A>, - Classless Inter-Domain Routing</LI> -<LI>Also see our<A href="biblio.html"> bibliography</A></LI> -</UL> -<H2><A name="implement">IPsec Implementations</A></H2> -<H3><A name="linuxprod">Linux products</A></H3> -<P>Vendors using FreeS/WAN in turnkey firewall or VPN products are - listed in our<A href="#turnkey"> introduction</A>.</P> -<P>Other vendors have Linux IPsec products which, as far as we know, do - not use FreeS/WAN</P> -<UL> -<LI><A href="http://www.redcreek.com/products/shareware.html">Redcreek</A> - provide an open source Linux driver for their PCI hardware VPN card. - This card has a 100 Mbit Ethernet port, an Intel 960 CPU plus more - specialised crypto chips, and claimed encryption performance of 45 - Mbit/sec. The PC sees it as an Ethernet board.</LI> -<LI><A href="http://linuxtoday.com/stories/8428.html?nn">Paktronix</A> - offer a Linux-based VPN with hardware encryption</LI> -<LI><A href="http://www.watchguard.com/">Watchguard</A> use Linux in - their Firebox product.</LI> -<LI><A href="http://www.entrust.com">Entrust</A> offer a developers' - toolkit for using their<A href="#PKI"> PKI</A> for IPsec authentication</LI> -<LI>According to a report on our mailing list,<A href="http://www.axent.com"> - Axent</A> have a Linux version of their product.</LI> -</UL> -<H3><A name="router">IPsec in router products</A></H3> -<P>All the major router vendors support IPsec, at least in some models.</P> -<UL> -<LI><A href="http://www.cisco.com/warp/public/707/16.html">Cisco</A> - IPsec information</LI> -<LI>Ascend, now part of<A href="http://www.lucent.com/"> Lucent</A>, - have some IPsec-based products</LI> -<LI><A href="http://www.nortelnetworks.com/">Bay Networks</A>, now part - of Nortel, use IPsec in their Contivity switch product line</LI> -<LI><A href="http://www.3com.com/products/enterprise.html">3Com</A> have - a number of VPN products, some using IPsec</LI> -</UL> -<H3><A name="fw.web">IPsec in firewall products</A></H3> -<P>Many firewall vendors offer IPsec, either as a standard part of their - product, or an optional extra. A few we know about are:</P> -<UL> -<LI><A href="http://www.borderware.com/">Borderware</A></LI> -<LI><A href="http://www.ashleylaurent.com/vpn/ipsec_vpn.htm">Ashley - Laurent</A></LI> -<LI><A href="http://www.watchguard.com">Watchguard</A></LI> -<LI><A href="http://www.fx.dk/firewall/ipsec.html">Injoy</A> for OS/2</LI> -</UL> -<P>Vendors using FreeS/WAN in turnkey firewall products are listed in - our<A href="#turnkey"> introduction</A>.</P> -<H3><A name="ipsecos">Operating systems with IPsec support</A></H3> -<P>All the major open source operating systems support IPsec. See below - for details on<A href="#BSD"> BSD-derived</A> Unix variants.</P> -<P>Among commercial OS vendors, IPsec players include:</P> -<UL> -<LI><A href="http://msdn.microsoft.com/isapi/msdnlib.idc?theURL=/library/backgrnd/html/msdn_ip_security.htm"> -Microsoft</A> have put IPsec in their Windows 2000 and XP products</LI> -<LI><A href="http://www.s390.ibm.com/stories/1999/os390v2r8_pr.html">IBM</A> - announce a release of OS390 with IPsec support via a crypto - co-processor</LI> -<LI><A href="http://www.sun.com/solaris/ds/ds-security/ds-security.pdf"> -Sun</A> include IPsec in Solaris 8</LI> -<LI><A href="http://www.hp.com/security/products/extranet-security.html"> -Hewlett Packard</A> offer IPsec for their Unix machines</LI> -<LI>Certicom have IPsec available for the<A href="http://www.certicom.com/products/movian/movianvpn_tech.html"> - Palm</A>.</LI> -<LI>There were reports before the release that Apple's Mac OS X would - have IPsec support built in, but it did not seem to be there when we - last checked. If you find, it please let us know via the<A href="mail.html"> - mailing list</A>.</LI> -</UL> -<H3><A NAME="29_3_5">IPsec on network cards</A></H3> -<P>Network cards with built-in IPsec acceleration are available from at - least Intel, 3Com and Redcreek.</P> -<H3><A name="opensource">Open source IPsec implementations</A></H3> -<H4><A name="linuxipsec">Other Linux IPsec implementations</A></H4> -<P>We like to think of FreeS/WAN as<EM> the</EM> Linux IPsec - implementation, but it is not the only one. Others we know of are:</P> -<UL> -<LI><A href="http://www.enst.fr/~beyssac/pipsec/">pipsecd</A>, a - lightweight implementation of IPsec for Linux. Does not require kernel - recompilation.</LI> -<LI>Petr Novak's<A href="ftp://ftp.eunet.cz/icz/ipnsec/"> ipnsec</A>, - based on the OpenBSD IPsec code and using<A href="#photuris"> Photuris</A> - for key management</LI> -<LI>A now defunct project at<A href="http://www.cs.arizona.edu/security/hpcc-blue/linux.html"> - U of Arizona</A> (export controlled)</LI> -<LI><A href="http://snad.ncsl.nist.gov/cerberus">NIST Cerebus</A> - (export controlled)</LI> -</UL> -<H4><A name="BSD">IPsec for BSD Unix</A></H4> -<UL> -<LI><A href="http://www.kame.net/project-overview.html">KAME</A>, - several large Japanese companies co-operating on IPv6 and IPsec</LI> -<LI><A href="http://web.mit.edu/network/isakmp">US Naval Research Lab</A> - implementation of IPv6 and of IPsec for IPv4 (export controlled)</LI> -<LI><A href="http://www.openbsd.org">OpenBSD</A> includes IPsec as a - standard part of the distribution</LI> -<LI><A href="http://www.r4k.net/ipsec">IPsec for FreeBSD</A></LI> -<LI>a<A href="http://www.netbsd.org/Documentation/network/ipsec/"> FAQ</A> - on NetBSD's IPsec implementation</LI> -</UL> -<H4><A name="misc">IPsec for other systems</A></H4> -<UL> -<LI><A href="http://www.tcm.hut.fi/Tutkimus/IPSEC/">Helsinki U of - Technolgy</A> have implemented IPsec for Solaris, Java and Macintosh</LI> -</UL> -<H3><A name="interop.web">Interoperability</A></H3> -<P>The IPsec protocols are designed so that different implementations - should be able to work together. As they say "the devil is in the - details". IPsec has a lot of details, but considerable success has been - achieved.</P> -<H4><A name="result">Interoperability results</A></H4> -<P>Linux FreeS/WAN has been tested for interoperability with many other - IPsec implementations. Results to date are in our<A href="interop.html"> - interoperability</A> section.</P> -<P>Various other sites have information on interoperability between - various IPsec implementations:</P> -<UL> -<LI><A href="http://www.opus1.com/vpn/atl99display.html">interop results</A> - from a bakeoff in Atlanta, September 1999.</LI> -<LI>a French company, HSC's,<A href="http://www.hsc.fr/ressources/presentations/ipsec99/index.html.en"> - interoperability</A> test data covers FreeS/WAN, Open BSD, KAME, Linux - pipsecd, Checkpoint, Red Creek Ravlin, and Cisco IOS</LI> -<LI><A href="http://www.icsa.net/">ICSA</A> offer certification programs - for various security-related products. See their list of<A href="http://www.icsa.net/html/communities/ipsec/certification/certified_products/index.shtml"> - certified IPsec</A> products. Linux FreeS/WAN is not currently on that - list, but several products with which we interoperate are.</LI> -<LI>VPNC have a page on why they are not yet doing<A href="http://www.vpnc.org/interop.html"> - interoperability</A> testing and a page on the<A href="http://www.vpnc.org/conformance.html"> - spec conformance</A> testing that they are doing</LI> -<LI>a<A href="http://www.commweb.com/article/COM20000912S0009"> review</A> - comparing a dozen commercial IPsec implemetations. Unfortunately, the - reviewers did not look at Open Source implementations such as FreeS/WAN - or OpenBSD.</LI> -<LI><A href="http://www.tanu.org/~sakane/doc/public/report-ike-interop0007.html"> -results</A> from interoperability tests at a conference. FreeS/WAN was - not tested there.</LI> -<LI>test results from the<A href="http://www.hsc.fr/ressources/veille/ipsec/ipsec2000/"> - IPSEC 2000</A> conference</LI> -</UL> -<H4><A name="test1">Interoperability test sites</A></H4> -<UL> -<LI><A href="http://www.tahi.org/">TAHI</A>, a Japanese IPv6 testing - project with free IPsec validation software</LI> -<LI><A href="http://ipsec-wit.antd.nist.gov">National Institute of - Standards and Technology</A></LI> -<LI><A href="http://isakmp-test.ssh.fi/">SSH Communications Security</A></LI> -</UL> -<H2><A name="linux.link">Linux links</A></H2> -<H3><A name="linux.basic">Basic and tutorial Linux information</A></H3> -<UL> -<LI>Linux<A href="http://linuxcentral.com/linux/LDP/LDP/gs/gs.html"> - Getting Started</A> HOWTO document</LI> -<LI>A getting started guide from the<A href="http://darkwing.uoregon.edu/~cchome/linuxgettingstarted.html"> - U of Oregon</A></LI> -<LI>A large<A href="http://www.herring.org/techie.html"> link collection</A> - which includes a lot of introductory and tutorial material on Unix, - Linux, the net, . . .</LI> -</UL> -<H3><A name="general">General Linux sites</A></H3> -<UL> -<LI><A href="http://www.freshmeat.net">Freshmeat</A> Linux news</LI> -<LI><A href="http://slashdot.org">Slashdot</A> "News for Nerds"</LI> -<LI><A href="http://www.linux.org">Linux Online</A></LI> -<LI><A href="http://www.linuxhq.com">Linux HQ</A></LI> -<LI><A href="http://www.tux.org">tux.org</A></LI> -</UL> -<H3><A name="docs.ldp">Documentation</A></H3> -<P>Nearly any Linux documentation you are likely to want can be found at - the<A href="http://metalab.unc.edu/LDP"> Linux Documentation Project</A> - or LDP.</P> -<UL> -<LI><A href="http://metalab.unc.edu/LDP/HOWTO/META-FAQ.html">Meta-FAQ</A> - guide to Linux information sources</LI> -<LI>The LDP's HowTo documents are a standard Linux reference. See this<A href="http://www.linuxdoc.org/docs.html#howto"> - list</A>. Documents there most relevant to a FreeS/WAN gateway are: -<UL> -<LI><A href="http://metalab.unc.edu/LDP/HOWTO/Kernel-HOWTO.html">Kernel - HOWTO</A></LI> -<LI><A href="http://metalab.unc.edu/LDP/HOWTO/Networking-Overview-HOWTO.html"> -Networking Overview HOWTO</A></LI> -<LI><A href="http://metalab.unc.edu/LDP/HOWTO/Security-HOWTO.html"> -Security HOWTO</A></LI> -</UL> -</LI> -<LI>The LDP do a series of Guides, book-sized publications with more - detail (and often more "why do it this way?") than the HowTos. See this<A -href="http://www.linuxdoc.org/guides.html"> list</A>. Documents there - most relevant to a FreeS/WAN gateway are: -<UL> -<LI><A href="http://www.tml.hut.fi/~viu/linux/sag/">System - Administrator's Guide</A></LI> -<LI><A href="http://www.linuxdoc.org/LDP/nag2/index.html">Network - Adminstrator's Guide</A></LI> -<LI><A href="http://www.seifried.org/lasg/">Linux Administrator's - Security Guide</A></LI> -</UL> -</LI> -</UL> -<P>You may not need to go to the LDP to get this material. Most Linux - distributions include the HowTos on their CDs and several include the - Guides as well. Also, most of the Guides and some collections of HowTos - are available in book form from various publishers.</P> -<P>Much of the LDP material is also available in languages other than - English. See this<A href="http://www.linuxdoc.org/links/nenglish.html"> - LDP page</A>.</P> -<H3><A name="advroute.web">Advanced routing</A></H3> -<P>The Linux IP stack has some new features in 2.4 kernels. Some HowTos - have been written:</P> -<UL> -<LI>several HowTos for the<A href="http://netfilter.samba.org/unreliable-guides/"> - netfilter</A> firewall code in newer kernels</LI> -<LI><A href="http://www.ds9a.nl/2.4Networking/HOWTO//cvs/2.4routing/output/2.4networking.html"> -2.4 networking</A> HowTo</LI> -<LI><A href="http://www.ds9a.nl/2.4Networking/HOWTO//cvs/2.4routing/output/2.4routing.html"> -2.4 routing</A> HowTo</LI> -</UL> -<H3><A name="linsec">Security for Linux</A></H3> -<P>See also the<A href="#docs.ldp"> LDP material</A> above.</P> -<UL> -<LI><A href="http://www.ecst.csuchico.edu/~dranch/LINUX/index-linux.html#trinityos"> -Trinity OS guide to setting up Linux</A></LI> -<LI><A href="http://www.deter.com/unix">Unix security</A> page</LI> -<LI><A href="http://linux01.gwdg.de/~alatham/">PPDD</A> encrypting - filesystem</LI> -<LI><A href="http://EncryptionHOWTO.sourceforge.net/">Linux Encryption - HowTo</A> (outdated when last checked, had an Oct 2000 revision date in - March 2002)</LI> -</UL> -<H3><A name="firewall.linux">Linux firewalls</A></H3> -<P>Our<A href="firewall.html"> FreeS/WAN and firewalls</A> document - includes links to several sets of<A href="#examplefw"> scripts</A> - known to work with FreeS/WAN.</P> -<P>Other information sources:</P> -<UL> -<LI><A href="http://ipmasq.cjb.net/">IP Masquerade resource page</A></LI> -<LI><A href="http://netfilter.samba.org/unreliable-guides/">netfilter</A> - firewall code in 2.4 kernels</LI> -<LI>Our list of general<A href="#firewall.web"> firewall references</A> - on the web</LI> -<LI><A href="http://users.dhp.com/~whisper/mason/">Mason</A>, a tool for - automatically configuring Linux firewalls</LI> -<LI>the web cache software<A href="http://www.squid-cache.org/"> squid</A> - and<A href="http://www.squidguard.org/"> squidguard</A> which turns - Squid into a filtering web proxy</LI> -</UL> -<H3><A name="linux.misc">Miscellaneous Linux information</A></H3> -<UL> -<LI><A href="http://lwn.net/current/dists.php3">Linux distribution - vendors</A></LI> -<LI><A href="http://www.linux.org/groups/">Linux User Groups</A></LI> -</UL> -<H2><A name="crypto.link">Crypto and security links</A></H2> -<H3><A name="security">Crypto and security resources</A></H3> -<H4><A name="std.links">The standard link collections</A></H4> -<P>Two enormous collections of links, each the standard reference in its - area:</P> -<DL> -<DT>Gene Spafford's<A href="http://www.cerias.purdue.edu/coast/hotlist/"> - COAST hotlist</A></DT> -<DD>Computer and network security.</DD> -<DT>Peter Gutmann's<A href="http://www.cs.auckland.ac.nz/~pgut001/links.html"> - Encryption and Security-related Resources</A></DT> -<DD>Cryptography.</DD> -</DL> -<H4><A name="FAQ">Frequently Asked Question (FAQ) documents</A></H4> -<UL> -<LI><A href="http://www.faqs.org/faqs/cryptography-faq/">Cryptography - FAQ</A></LI> -<LI><A href="http://www.interhack.net/pubs/fwfaq">Firewall FAQ</A></LI> -<LI><A href="http://www.whitefang.com/sup/secure-faq.html">Secure Unix - Programming FAQ</A></LI> -<LI>FAQs for specific programs are listed in the<A href="#tools"> tools</A> - section below.</LI> -</UL> -<H4><A name="cryptover">Tutorials</A></H4> -<UL> -<LI>Gary Kessler's<A href="http://www.garykessler.net/library/crypto.html"> - Overview of Cryptography</A></LI> -<LI>Terry Ritter's<A href="http://www.ciphersbyritter.com/LEARNING.HTM"> - introduction</A></LI> -<LI>Peter Gutman's<A href="http://www.cs.auckland.ac.nz/~pgut001/tutorial/index.html"> - cryptography</A> tutorial (500 slides in PDF format)</LI> -<LI>Amir Herzberg of IBM's sildes for his course<A href="http://www.hrl.il.ibm.com/mpay/course.html"> - Introduction to Cryptography and Electronic Commerce</A></LI> -<LI>the<A href="http://www.gnupg.org/gph/en/manual/c173.html"> concepts - section</A> of the<A href="#GPG"> GNU Privacy Guard</A> documentation</LI> -<LI>Bruce Schneier's self-study<A href="http://www.counterpane.com/self-study.html"> - cryptanalysis</A> course</LI> -</UL> -<P>See also the<A href="#interesting"> interesting papers</A> section - below.</P> -<H4><A name="standards">Crypto and security standards</A></H4> -<UL> -<LI><A href="http://csrc.nist.gov/cc">Common Criteria</A>, new - international computer and network security standards to replace the - "Rainbow" series</LI> -<LI>AES<A href="http://csrc.nist.gov/encryption/aes/aes_home.htm"> - Advanced Encryption Standard</A> which will replace DES</LI> -<LI><A href="http://grouper.ieee.org/groups/1363">IEEE P-1363 public key - standard</A></LI> -<LI>our collection of links for the<A href="#ipsec.link"> IPsec</A> - standards</LI> -<LI>history of<A href="http://www.visi.com/crypto/evalhist/index.html"> - formal evaluation</A> of security policies and implementation</LI> -</UL> -<H4><A name="quotes">Crypto quotes</A></H4> -<P>There are several collections of cryptographic quotes on the net:</P> -<UL> -<LI><A href="http://www.eff.org/pub/EFF/quotes.eff">the EFF</A></LI> -<LI><A href="http://www.samsimpson.com/cquotes.php">Sam Simpson</A></LI> -<LI><A href="http://www.amk.ca/quotations/cryptography/page-1.html">AM - Kutchling</A></LI> -</UL> -<H3><A name="policy">Cryptography law and policy</A></H3> -<H4><A name="legal">Surveys of crypto law</A></H4> -<UL> -<LI>International survey of<A href="http://cwis.kub.nl/~FRW/PEOPLE/koops/lawsurvy.htm"> - crypto law</A>.</LI> -<LI>International survey of<A href="http://rechten.kub.nl/simone/ds-lawsu.htm"> - digital signature law</A></LI> -</UL> -<H4><A name="oppose">Organisations opposing crypto restrictions</A></H4> -<UL> -<LI>The<A href="#EFF"> EFF</A>'s archives on<A href="http://www.eff.org/pub/Privacy/"> - privacy</A> and<A href="http://www.eff.org/pub/Privacy/ITAR_export/"> - export control</A>.</LI> -<LI><A href="http://www.gilc.org">Global Internet Liberty Campaign</A></LI> -<LI><A href="http://www.cdt.org/crypto">Center for Democracy and - Technology</A></LI> -<LI><A href="http://www.privacyinternational.org/">Privacy International</A> -, who give out<A href="http://www.bigbrotherawards.org/"> Big Brother - Awards</A> to snoopy organisations</LI> -</UL> -<H4><A name="other.policy">Other information on crypto policy</A></H4> -<UL> -<LI><A href="ftp://ftp.isi.edu/in-notes/rfc1984.txt">RFC 1984</A>, the<A href="#IAB"> - IAB</A> and<A href="#IESG"> IESG</A> Statement on Cryptographic - Technology and the Internet.</LI> -<LI>John Young's collection of<A href="http://cryptome.org/"> documents</A> - of interest to the cryptography, open government and privacy movements, - organized chronologically</LI> -<LI>AT&T researcher Matt Blaze's Encryption, Privacy and Security<A href="http://www.crypto.com"> - Resource Page</A></LI> -<LI>A good<A href="http://cryptome.org/crypto97-ne.htm"> overview</A> of - the issues from Australia.</LI> -</UL> -<P>See also our documentation section on the<A href="politics.html"> - history and politics</A> of cryptography.</P> -<H3><A name="crypto.tech">Cryptography technical information</A></H3> -<H4><A name="cryptolinks">Collections of crypto links</A></H4> -<UL> -<LI><A href="http://www.counterpane.com/hotlist.html">Counterpane</A></LI> -<LI><A href="http://www.cs.auckland.ac.nz/~pgut001/links.html">Peter - Gutman's links</A></LI> -<LI><A href="http://www.pca.dfn.de/eng/team/ske/pem-dok.html">PKI links</A> -</LI> -<LI><A href="http://crypto.yashy.com/www/">Robert Guerra's links</A></LI> -</UL> -<H4><A name="papers">Lists of online cryptography papers</A></H4> -<UL> -<LI><A href="http://www.counterpane.com/biblio">Counterpane</A></LI> -<LI><A href="http://www.cryptography.com/resources/papers"> -cryptography.com</A></LI> -<LI><A href="http://www.cryptosoft.com/html/secpub.htm">Cryptosoft</A></LI> -</UL> -<H4><A name="interesting">Particularly interesting papers</A></H4> -<P>These papers emphasize important issues around the use of - cryptography, and the design and management of secure systems.</P> -<UL> -<LI><A href="http://www.counterpane.com/keylength.html">Key length - requirements for security</A></LI> -<LI><A href="http://www.cl.cam.ac.uk/users/rja14/wcf.html">Why - Cryptosystems Fail</A></LI> -<LI><A href="http://www.cdt.org/crypto/risks98/">Risks of escrowed - encryption</A></LI> -<LI><A href="http://www.counterpane.com/pitfalls.html">Security pitfalls - in cryptography</A></LI> -<LI><A href="http://www.acm.org/classics/sep95">Reflections on Trusting - Trust</A>, Ken Thompson on Trojan horse design</LI> -<LI><A href="http://www.apache-ssl.org/disclosure.pdf">Security against - Compelled Disclosure</A>, how to maintain privacy in the face of legal - or other coersion</LI> -</UL> -<H3><A name="compsec">Computer and network security</A></H3> -<H4><A name="seclink">Security links</A></H4> -<UL> -<LI><A href="http://www.cs.purdue.edu/coast/hotlist">COAST Hotlist</A></LI> -<LI>DMOZ open directory project<A href="http://dmoz.org/Computers/Security/"> - computer security</A> links</LI> -<LI><A href="http://www-cse.ucsd.edu/users/bsy/sec.html">Bennet Yee</A></LI> -<LI>Mike Fuhr's<A href="http://www.fuhr.org/~mfuhr/computers/security.html"> - link collection</A></LI> -<LI><A href="http://www.networkintrusion.co.uk/">links</A> with an - emphasis on intrusion detection</LI> -</UL> -<H4><A name="firewall.web">Firewall links</A></H4> -<UL> -<LI><A href="http://www.cs.purdue.edu/coast/firewalls">COAST firewalls</A> -</LI> -<LI><A href="http://www.zeuros.co.uk">Firewalls Resource page</A></LI> -</UL> -<H4><A name="vpn">VPN links</A></H4> -<UL> -<LI><A href="http://www.vpnc.org">VPN Consortium</A></LI> -<LI>First VPN's<A href="http://www.firstvpn.com/research/rhome.html"> - white paper</A> collection</LI> -</UL> -<H4><A name="tools">Security tools</A></H4> -<UL> -<LI>PGP -- mail encryption -<UL> -<LI><A href="http://www.pgp.com/">PGP Inc.</A> (part of NAI) for - commercial versions</LI> -<LI><A href="http://web.mit.edu/network/pgp.html">MIT</A> distributes - the NAI product for non-commercial use</LI> -<LI><A href="http://www.pgpi.org/">international</A> distribution site</LI> -<LI><A href="http://gnupg.org">GNU Privacy Guard (GPG)</A></LI> -<LI><A href="http://www.dk.pgp.net/pgpnet/pgp-faq/">PGP FAQ</A></LI> -</UL> - A message in our mailing list archive has considerable detail on<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/12/msg00029.html"> - available versions</A> of PGP and on IPsec support in them. -<P><STRONG>Note:</STRONG> A fairly nasty bug exists in all commercial - PGP versions from 5.5 through 6.5.3. If you have one of those,<STRONG> - upgrade now</STRONG>.</P> -</LI> -<LI>SSH -- secure remote login -<UL> -<LI><A href="http://www.ssh.fi">SSH Communications Security</A>, for the - original software. It is free for trial, academic and non-commercial - use.</LI> -<LI><A href="http://www.openssh.com/">Open SSH</A>, the Open BSD team's - free replacement</LI> -<LI><A href="http://www.freessh.org/">freessh.org</A>, links to free - implementations for many systems</LI> -<LI><A href="http://www.uni-karlsruhe.de/~ig25/ssh-faq">SSH FAQ</A></LI> -<LI><A href="http://www.chiark.greenend.org.uk/~sgtatham/putty/">Putty</A> -, an SSH client for Windows</LI> -</UL> -</LI> -<LI>Tripwire saves message digests of your system files. Re-calculate - the digests and compare to saved values to detect any file changes. - There are several versions available: -<UL> -<LI><A href="http://www.tripwiresecurity.com/">commercial version</A></LI> -<LI><A href="http://www.tripwire.org/">Open Source</A></LI> -</UL> -</LI> -<LI><A href="http://www.snort.org">Snort</A> and<A href="http://www.lids.org"> - LIDS</A> are intrusion detection system for Linux</LI> -<LI><A href="http://www.fish.com/~zen/satan/satan.html">SATAN</A> System - Administrators Tool for Analysing Networks</LI> -<LI><A href="http://www.insecure.org/nmap/">NMAP</A> Network Mapper</LI> -<LI><A href="ftp://ftp.porcupine.org/pub/security/index.html">Wietse - Venema's page</A> with various tools</LI> -<LI><A href="http://ita.ee.lbl.gov/index.html">Internet Traffic Archive</A> -, various tools to analyze network traffic, mostly scripts to organise - and format tcpdump(8) output for specific purposes</LI> -<LI><A name="ssmail">ssmail -- sendmail patched to do</A><A href="#carpediem"> - opportunistic encryption</A> -<UL> -<LI><A href="http://www.home.aone.net.au/qualcomm/">web page</A> with - links to code and to a Usenix paper describing it, in PDF</LI> -</UL> -</LI> -<LI><A href="http://www.openca.org/">Open CA</A> project to develop a - freely distributed<A href="#CA"> Certification Authority</A> for - building a open<A href="#PKI"> Public Key Infrastructure</A>.</LI> -</UL> -<H3><A name="people">Links to home pages</A></H3> -<P>David Wagner at Berkeley provides a set of links to<A href="http://www.cs.berkeley.edu/~daw/people/crypto.html"> - home pages</A> of cryptographers, cypherpunks and computer security - people.</P> -<HR> -<H1><A name="ourgloss">Glossary for the Linux FreeS/WAN project</A></H1> -<P>Entries are in alphabetical order. Some entries are only one line or - one paragraph long. Others run to several paragraphs. I have tried to - put the essential information in the first paragraph so you can skip - the other paragraphs if that seems appropriate.</P> -<HR> -<H2><A name="jump">Jump to a letter in the glossary</A></H2> -<CENTER> <BIG><B><A href="#0">numeric</A><A href="#A"> A</A><A href="#B"> - B</A><A href="#C"> C</A><A href="#D"> D</A><A href="#E"> E</A><A href="#F"> - F</A><A href="#G"> G</A><A href="#H"> H</A><A href="#I"> I</A><A href="#J"> - J</A><A href="#K"> K</A><A href="#L"> L</A><A href="#M"> M</A><A href="#N"> - N</A><A href="#O"> O</A><A href="#P"> P</A><A href="#Q"> Q</A><A href="#R"> - R</A><A href="#S"> S</A><A href="#T"> T</A><A href="#U"> U</A><A href="#V"> - V</A><A href="#W"> W</A><A href="#X"> X</A><A href="#Y"> Y</A><A href="#Z"> - Z</A></B></BIG></CENTER> -<HR> -<H2><A name="gloss">Other glossaries</A></H2> -<P>Other glossaries which overlap this one include:</P> -<UL> -<LI>The VPN Consortium's glossary of<A href="http://www.vpnc.org/terms.html"> - VPN terms</A>.</LI> -<LI>glossary portion of the<A href="http://www.rsa.com/rsalabs/faq/B.html"> - Cryptography FAQ</A></LI> -<LI>an extensive crytographic glossary on<A href="http://www.ciphersbyritter.com/GLOSSARY.HTM"> - Terry Ritter's</A> page.</LI> -<LI>The<A href="#NSA"> NSA</A>'s<A href="http://www.sans.org/newlook/resources/glossary.htm"> - glossary of computer security</A> on the<A href="http://www.sans.org"> - SANS Institute</A> site.</LI> -<LI>a small glossary for Internet Security at<A href="http://www5.zdnet.com/pcmag/pctech/content/special/glossaries/internetsecurity.html"> - PC magazine</A></LI> -<LI>The<A href="http://www.visi.com/crypto/inet-crypto/glossary.html"> - glossary</A> from Richard Smith's book<A href="#Smith"> Internet - Cryptography</A></LI> -</UL> -<P>Several Internet glossaries are available as RFCs:</P> -<UL> -<LI><A href="http://www.rfc-editor.org/rfc/rfc1208.txt">Glossary of - Networking Terms</A></LI> -<LI><A href="http://www.rfc-editor.org/rfc/rfc1983.txt">Internet User's - Glossary</A></LI> -<LI><A href="http://www.rfc-editor.org/rfc/rfc2828.txt">Internet - Security Glossary</A></LI> -</UL> -<P>More general glossary or dictionary information:</P> -<UL> -<LI>Free Online Dictionary of Computing (FOLDOC) -<UL> -<LI><A href="http://www.nightflight.com/foldoc">North America</A></LI> -<LI><A href="http://wombat.doc.ic.ac.uk/foldoc/index.html">Europe</A></LI> -<LI><A href="http://www.nue.org/foldoc/index.html">Japan</A></LI> -</UL> -<P>There are many more mirrors of this dictionary.</P> -</LI> -<LI>The Jargon File, the definitive resource for hacker slang and - folklore -<UL> -<LI><A href="http://www.netmeg.net/jargon">North America</A></LI> -<LI><A href="http://info.wins.uva.nl/~mes/jargon/">Holland</A></LI> -<LI><A href="http://www.tuxedo.org/~esr/jargon">home page</A></LI> -</UL> -<P>There are also many mirrors of this. See the home page for a list.</P> -</LI> -<LI>A general<A href="http://www.trinity.edu/~rjensen/245glosf.htm#Navigate"> - technology glossary</A></LI> -<LI>An<A href="http://www.yourdictionary.com/"> online dictionary - resource page</A> with pointers to many dictionaries for many languages</LI> -<LI>A<A href="http://www.onelook.com/"> search engine</A> that accesses - several hundred online dictionaries</LI> -<LI>O'Reilly<A href="http://www.ora.com/reference/dictionary/"> - Dictionary of PC Hardware and Data Communications Terms</A></LI> -<LI><A href="http://www.FreeSoft.org/CIE/index.htm">Connected</A> - Internet encyclopedia</LI> -<LI><A href="http://www.whatis.com/">whatis.com</A></LI> -</UL> -<HR> -<H2><A name="definitions">Definitions</A></H2> -<DL> -<DT><A name="0">0</A></DT> -<DT><A name="3DES">3DES (Triple DES)</A></DT> -<DD>Using three<A href="#DES"> DES</A> encryptions on a single data - block, with at least two different keys, to get higher security than is - available from a single DES pass. The three-key version of 3DES is the - default encryption algorithm for<A href="#FreeSWAN"> Linux FreeS/WAN</A> -. -<P><A href="#IPSEC">IPsec</A> always does 3DES with three different - keys, as required by RFC 2451. For an explanation of the two-key - variant, see<A href="#2key"> two key triple DES</A>. Both use an<A href="#EDE"> - EDE</A> encrypt-decrypt-encrpyt sequence of operations.</P> -<P>Single<A href="#DES"> DES</A> is<A href="#desnotsecure"> insecure</A> -.</P> -<P>Double DES is ineffective. Using two 56-bit keys, one might expect an - attacker to have to do 2<SUP>112</SUP> work to break it. In fact, only - 2<SUP>57</SUP> work is required with a<A href="#meet"> - meet-in-the-middle attack</A>, though a large amount of memory is also - required. Triple DES is vulnerable to a similar attack, but that just - reduces the work factor from the 2<SUP>168</SUP> one might expect to 2<SUP> -112</SUP>. That provides adequate protection against<A href="#brute"> - brute force</A> attacks, and no better attack is known.</P> -<P>3DES can be somewhat slow compared to other ciphers. It requires - three DES encryptions per block. DES was designed for hardware - implementation and includes some operations which are difficult in - software. However, the speed we get is quite acceptable for many uses. - See our<A href="performance.html"> performance</A> document for - details.</P> -</DD> -<DT><A name="A">A</A></DT> -<DT><A name="active">Active attack</A></DT> -<DD>An attack in which the attacker does not merely eavesdrop (see<A href="#passive"> - passive attack</A>) but takes action to change, delete, reroute, add, - forge or divert data. Perhaps the best-known active attack is<A href="#middle"> - man-in-the-middle</A>. In general,<A href="#authentication"> - authentication</A> is a useful defense against active attacks.</DD> -<DT><A name="AES">AES</A></DT> -<DD>The<B> A</B>dvanced<B> E</B>ncryption<B> S</B>tandard -- a new<A href="#block"> - block cipher</A> standard to replace<A href="#desnotsecure"> DES</A> -- - developed by<A href="#NIST"> NIST</A>, the US National Institute of - Standards and Technology. DES used 64-bit blocks and a 56-bit key. AES - ciphers use a 128-bit block and 128, 192 or 256-bit keys. The larger - block size helps resist<A href="#birthday"> birthday attacks</A> while - the large key size prevents<A href="#brute"> brute force attacks</A>. -<P>Fifteen proposals meeting NIST's basic criteria were submitted in - 1998 and subjected to intense discussion and analysis, "round one" - evaluation. In August 1999, NIST narrowed the field to five "round two" - candidates:</P> -<UL> -<LI><A href="http://www.research.ibm.com/security/mars.html">Mars</A> - from IBM</LI> -<LI><A href="http://www.rsa.com/rsalabs/aes/">RC6</A> from RSA</LI> -<LI><A href="http://www.esat.kuleuven.ac.be/~rijmen/rijndael/">Rijndael</A> - from two Belgian researchers</LI> -<LI><A href="http://www.cl.cam.ac.uk/~rja14/serpent.html">Serpent</A>, a - British-Norwegian-Israeli collaboration</LI> -<LI><A href="http://www.counterpane.com/twofish.html">Twofish</A> from - the consulting firm<A href="http://www.counterpane.com"> Counterpane</A> -</LI> -</UL> -<P>Three of the five finalists -- Rijndael, Serpent and Twofish -- have - completely open licenses.</P> -<P>In October 2000, NIST announced the winner -- Rijndael.</P> -<P>For more information, see:</P> -<UL> -<LI>NIST's<A href="http://csrc.nist.gov/encryption/aes/aes_home.htm"> - AES home page</A></LI> -<LI>the Block Cipher Lounge<A href="http://www.ii.uib.no/~larsr/aes.html"> - AES page</A></LI> -<LI>Brian Gladman's<A href="http://fp.gladman.plus.com/cryptography_technology/index.htm"> - code and benchmarks</A></LI> -<LI>Helger Lipmaa's<A href="http://www.tcs.hut.fi/~helger/aes/"> survey - of implementations</A></LI> -</UL> -<P>AES will be added to a future release of<A href="#FreeSWAN"> Linux - FreeS/WAN</A>. Likely we will add all three of the finalists with good - licenses. User-written<A href="#patch"> AES patches</A> are already - available.</P> -<P>Adding AES may also require adding stronger hashes,<A href="#SHA-256"> - SHA-256, SHA-384 and SHA-512</A>.</P> -</DD> -<DT><A name="AH">AH</A></DT> -<DD>The<A href="#IPSEC"> IPsec</A><B> A</B>uthentication<B> H</B>eader, - added after the IP header. For details, see our<A href="#AH.ipsec"> - IPsec</A> document and/or RFC 2402.</DD> -<DT><A name="alicebob">Alice and Bob</A></DT> -<DD>A and B, the standard example users in writing on cryptography and - coding theory. Carol and Dave join them for protocols which require - more players. -<P>Bruce Schneier extends these with many others such as Eve the - Eavesdropper and Victor the Verifier. His extensions seem to be in the - process of becoming standard as well. See page 23 of<A href="#schneier"> - Applied Cryptography</A></P> -<P>Alice and Bob have an amusing<A href="http://www.conceptlabs.co.uk/alicebob.html"> - biography</A> on the web.</P> -</DD> -<DT>ARPA</DT> -<DD>see<A href="#DARPA"> DARPA</A></DD> -<DT><A name="ASIO">ASIO</A></DT> -<DD>Australian Security Intelligence Organisation.</DD> -<DT>Asymmetric cryptography</DT> -<DD>See<A href="#public"> public key cryptography</A>.</DD> -<DT><A name="authentication">Authentication</A></DT> -<DD>Ensuring that a message originated from the expected sender and has - not been altered on route.<A href="#IPSEC"> IPsec</A> uses - authentication in two places: -<UL> -<LI>peer authentication, authenticating the players in<A href="#IKE"> - IKE</A>'s<A href="#DH"> Diffie-Hellman</A> key exchanges to prevent<A href="#middle"> - man-in-the-middle attacks</A>. This can be done in a number of ways. - The methods supported by FreeS/WAN are discussed in our<A href="#choose"> - advanced configuration</A> document.</LI> -<LI>packet authentication, authenticating packets on an established<A href="#SA"> - SA</A>, either with a separate<A href="#AH"> authentication header</A> - or with the optional authentication in the<A href="#ESP"> ESP</A> - protocol. In either case, packet authentication uses a<A href="#HMAC"> - hashed message athentication code</A> technique.</LI> -</UL> -<P>Outside IPsec, passwords are perhaps the most common authentication - mechanism. Their function is essentially to authenticate the person's - identity to the system. Passwords are generally only as secure as the - network they travel over. If you send a cleartext password over a - tapped phone line or over a network with a packet sniffer on it, the - security provided by that password becomes zero. Sending an encrypted - password is no better; the attacker merely records it and reuses it at - his convenience. This is called a<A href="#replay"> replay</A> attack.</P> -<P>A common solution to this problem is a<A href="#challenge"> - challenge-response</A> system. This defeats simple eavesdropping and - replay attacks. Of course an attacker might still try to break the - cryptographic algorithm used, or the<A href="#random"> random number</A> - generator.</P> -</DD> -<DT><A name="auto">Automatic keying</A></DT> -<DD>A mode in which keys are automatically generated at connection - establisment and new keys automaically created periodically thereafter. - Contrast with<A href="#manual"> manual keying</A> in which a single - stored key is used. -<P>IPsec uses the<A href="#DH"> Diffie-Hellman key exchange protocol</A> - to create keys. An<A href="#authentication"> authentication</A> - mechansim is required for this. FreeS/WAN normally uses<A href="#RSA"> - RSA</A> for this. Other methods supported are discussed in our<A href="#choose"> - advanced configuration</A> document.</P> -<P>Having an attacker break the authentication is emphatically not a - good idea. An attacker that breaks authentication, and manages to - subvert some other network entities (DNS, routers or gateways), can use - a<A href="#middle"> man-in-the middle attack</A> to break the security - of your IPsec connections.</P> -<P>However, having an attacker break the authentication in automatic - keying is not quite as bad as losing the key in manual keying.</P> -<UL> -<LI>An attacker who reads /etc/ipsec.conf and gets the keys for a - manually keyed connection can, without further effort, read all - messages encrypted with those keys, including any old messages he may - have archived.</LI> -<LI>Automatic keying has a property called<A href="#PFS"> perfect - forward secrecy</A>. An attacker who breaks the authentication gets - none of the automatically generated keys and cannot immediately read - any messages. He has to mount a successful<A href="#middle"> - man-in-the-middle attack</A> in real time before he can read anything. - He cannot read old archived messages at all and will not be able to - read any future messages not caught by man-in-the-middle tricks.</LI> -</UL> -<P>That said, the secrets used for authentication, stored in<A href="manpage.d/ipsec.secrets.5.html"> - ipsec.secrets(5)</A>, should still be protected as tightly as - cryptographic keys.</P> -</DD> -<DT><A name="B">B</A></DT> -<DT><A href="http://www.nortelnetworks.com">Bay Networks</A></DT> -<DD>A vendor of routers, hubs and related products, now a subsidiary of - Nortel. Interoperation between their IPsec products and Linux FreeS/WAN - was problematic at last report; see our<A href="interop.html#bay"> - interoperation</A> section.</DD> -<DT><A name="benchmarks">benchmarks</A></DT> -<DD>Our default block cipher,<A href="#3DES"> triple DES</A>, is slower - than many alternate ciphers that might be used. Speeds achieved, - however, seem adequate for many purposes. For example, the assembler - code from the<A href="#LIBDES"> LIBDES</A> library we use encrypts 1.6 - megabytes per second on a Pentium 200, according to the test program - supplied with the library. -<P>For more detail, see our document on<A href="performance.html"> - FreeS/WAN performance</A>.</P> -</DD> -<DT><A name="BIND">BIND</A></DT> -<DD><B>B</B>erkeley<B> I</B>nternet<B> N</B>ame<B> D</B>aemon, a widely - used implementation of<A href="#DNS"> DNS</A> (Domain Name Service). - See our bibliography for a<A href="#DNS"> useful reference</A>. See the<A -href="http://www.isc.org/bind.html"> BIND home page</A> for more - information and the latest version.</DD> -<DT><A name="birthday">Birthday attack</A></DT> -<DD>A cryptographic attack based on the mathematics exemplified by the<A href="#paradox"> - birthday paradox</A>. This math turns up whenever the question of two - cryptographic operations producing the same result becomes an issue: -<UL> -<LI><A href="#collision">collisions</A> in<A href="#digest"> message - digest</A> functions.</LI> -<LI>identical output blocks from a<A href="#block"> block cipher</A></LI> -<LI>repetition of a challenge in a<A href="#challenge"> - challenge-response</A> system</LI> -</UL> -<P>Resisting such attacks is part of the motivation for:</P> -<UL> -<LI>hash algorithms such as<A href="#SHA"> SHA</A> and<A href="#RIPEMD"> - RIPEMD-160</A> giving a 160-bit result rather than the 128 bits of<A href="#MD4"> - MD4</A>,<A href="#MD5"> MD5</A> and<A href="#RIPEMD"> RIPEMD-128</A>.</LI> -<LI><A href="#AES">AES</A> block ciphers using a 128-bit block instead - of the 64-bit block of most current ciphers</LI> -<LI><A href="#IPSEC">IPsec</A> using a 32-bit counter for packets sent - on an<A href="#auto"> automatically keyed</A><A href="#SA"> SA</A> and - requiring that the connection always be rekeyed before the counter - overflows.</LI> -</UL> -</DD> -<DT><A name="paradox">Birthday paradox</A></DT> -<DD>Not really a paradox, just a rather counter-intuitive mathematical - fact. In a group of 23 people, the chance of a least one pair having - the same birthday is over 50%. -<P>The second person has 1 chance in 365 (ignoring leap years) of - matching the first. If they don't match, the third person's chances of - matching one of them are 2/365. The 4th, 3/365, and so on. The total of - these chances grows more quickly than one might guess.</P> -</DD> -<DT><A name="block">Block cipher</A></DT> -<DD>A<A href="#symmetric"> symmetric cipher</A> which operates on - fixed-size blocks of plaintext, giving a block of ciphertext for each. - Contrast with<A href="#stream"> stream cipher</A>. Block ciphers can be - used in various<A href="#mode"> modes</A> when multiple block are to be - encrypted. -<P><A href="#DES">DES</A> is among the the best known and widely used - block ciphers, but is now obsolete. Its 56-bit key size makes it<A href="#desnotsecure"> - highly insecure</A> today.<A href="#3DES"> Triple DES</A> is the - default block cipher for<A href="#FreeSWAN"> Linux FreeS/WAN</A>.</P> -<P>The current generation of block ciphers -- such as<A href="#Blowfish"> - Blowfish</A>,<A href="#CAST128"> CAST-128</A> and<A href="#IDEA"> IDEA</A> - -- all use 64-bit blocks and 128-bit keys. The next generation,<A href="#AES"> - AES</A>, uses 128-bit blocks and supports key sizes up to 256 bits.</P> -<P>The<A href="http://www.ii.uib.no/~larsr/bc.html"> Block Cipher Lounge</A> - web site has more information.</P> -</DD> -<DT><A name="Blowfish">Blowfish</A></DT> -<DD>A<A href="#block"> block cipher</A> using 64-bit blocks and keys of - up to 448 bits, designed by<A href="#schneier"> Bruce Schneier</A> and - used in several products. -<P>This is not required by the<A href="#IPSEC"> IPsec</A> RFCs and not - currently used in<A href="#FreeSWAN"> Linux FreeS/WAN</A>.</P> -</DD> -<DT><A name="brute">Brute force attack (exhaustive search)</A></DT> -<DD>Breaking a cipher by trying all possible keys. This is always - possible in theory (except against a<A href="#OTP"> one-time pad</A>), - but it becomes practical only if the key size is inadequate. For an - important example, see our document on the<A href="#desnotsecure"> - insecurity of DES</A> with its 56-bit key. For an analysis of key sizes - required to resist plausible brute force attacks, see<A href="http://www.counterpane.com/keylength.html"> - this paper</A>. -<P>Longer keys protect against brute force attacks. Each extra bit in - the key doubles the number of possible keys and therefore doubles the - work a brute force attack must do. A large enough key defeats<STRONG> - any</STRONG> brute force attack.</P> -<P>For example, the EFF's<A href="#EFF"> DES Cracker</A> searches a - 56-bit key space in an average of a few days. Let us assume an attacker - that can find a 64-bit key (256 times harder) by brute force search in - a second (a few hundred thousand times faster). For a 96-bit key, that - attacker needs 2<SUP>32</SUP> seconds, about 135 years. Against a - 128-bit key, he needs 2<SUP>32</SUP> times that, over 500,000,000,000 - years. Your data is then obviously secure against brute force attacks. - Even if our estimate of the attacker's speed is off by a factor of a - million, it still takes him over 500,000 years to crack a message.</P> -<P>This is why</P> -<UL> -<LI>single<A href="#DES"> DES</A> is now considered<A href="#desnotsecure"> - dangerously insecure</A></LI> -<LI>all of the current generation of<A href="#block"> block ciphers</A> - use a 128-bit or longer key</LI> -<LI><A href="#AES">AES</A> ciphers support keysizes 128, 192 and 256 - bits</LI> -<LI>any cipher we add to Linux FreeS/WAN will have<EM> at least</EM> a - 128-bit key</LI> -</UL> -<P><STRONG>Cautions:</STRONG> -<BR><EM> Inadequate keylength always indicates a weak cipher</EM> but it - is important to note that<EM> adequate keylength does not necessarily - indicate a strong cipher</EM>. There are many attacks other than brute - force, and adequate keylength<EM> only</EM> guarantees resistance to - brute force. Any cipher, whatever its key size, will be weak if design - or implementation flaws allow other attacks.</P> -<P>Also,<EM> once you have adequate keylength</EM> (somewhere around 90 - or 100 bits),<EM> adding more key bits make no practical difference</EM> -, even against brute force. Consider our 128-bit example above that - takes 500,000,000,000 years to break by brute force. We really don't - care how many zeroes there are on the end of that, as long as the - number remains ridiculously large. That is, we don't care exactly how - large the key is as long as it is large enough.</P> -<P>There may be reasons of convenience in the design of the cipher to - support larger keys. For example<A href="#Blowfish"> Blowfish</A> - allows up to 448 bits and<A href="#RC4"> RC4</A> up to 2048, but beyond - 100-odd bits it makes no difference to practical security.</P> -</DD> -<DT>Bureau of Export Administration</DT> -<DD>see<A href="#BXA"> BXA</A></DD> -<DT><A name="BXA">BXA</A></DT> -<DD>The US Commerce Department's<B> B</B>ureau of E<B>x</B>port<B> A</B> -dministration which administers the<A href="#EAR"> EAR</A> Export - Administration Regulations controling the export of, among other - things, cryptography.</DD> -<DT><A name="C">C</A></DT> -<DT><A name="CA">CA</A></DT> -<DD><B>C</B>ertification<B> A</B>uthority, an entity in a<A href="#PKI"> - public key infrastructure</A> that can certify keys by signing them. - Usually CAs form a hierarchy. The top of this hierarchy is called the<A href="#rootCA"> - root CA</A>. -<P>See<A href="#web"> Web of Trust</A> for an alternate model.</P> -</DD> -<DT><A name="CAST128">CAST-128</A></DT> -<DD>A<A href="#block"> block cipher</A> using 64-bit blocks and 128-bit - keys, described in RFC 2144 and used in products such as<A href="#Entrust"> - Entrust</A> and recent versions of<A href="#PGP"> PGP</A>. -<P>This is not required by the<A href="#IPSEC"> IPsec</A> RFCs and not - currently used in<A href="#FreeSWAN"> Linux FreeS/WAN</A>.</P> -</DD> -<DT>CAST-256</DT> -<DD><A href="#Entrust">Entrust</A>'s candidate cipher for the<A href="#AES"> - AES standard</A>, largely based on the<A href="#CAST128"> CAST-128</A> - design.</DD> -<DT><A name="CBC">CBC mode</A></DT> -<DD><B>C</B>ipher<B> B</B>lock<B> C</B>haining<A href="#mode"> mode</A>, - a method of using a<A href="#block"> block cipher</A> in which for each - block except the first, the result of the previous encryption is XORed - into the new block before it is encrypted. CBC is the mode used in<A href="#IPSEC"> - IPsec</A>. -<P>An<A href="#IV"> initialisation vector</A> (IV) must be provided. It - is XORed into the first block before encryption. The IV need not be - secret but should be different for each message and unpredictable.</P> -</DD> -<DT><A name="CIDR">CIDR</A></DT> -<DD><B>C</B>lassless<B> I</B>nter-<B>D</B>omain<B> R</B>outing, an - addressing scheme used to describe networks not restricted to the old - Class A, B, and C sizes. A CIDR block is written<VAR> address</VAR>/<VAR> -mask</VAR>, where<VAR> address</VAR> is a 32-bit Internet address. The - first<VAR> mask</VAR> bits of<VAR> address</VAR> are part of the - gateway address, while the remaining bits designate other host - addresses. For example, the CIDR block 192.0.2.96/27 describes a - network with gateway 192.0.2.96, hosts 192.0.2.96 through 192.0.2.126 - and broadcast 192.0.2.127. -<P>FreeS/WAN policy group files accept CIDR blocks of the format<VAR> - address</VAR>/[<VAR>mask</VAR>], where<VAR> address</VAR> may take the - form<VAR> name.domain.tld</VAR>. An absent<VAR> mask</VAR> is assumed - to be /32.</P> -</DD> -<DT>Certification Authority</DT> -<DD>see<A href="#CA"> CA</A></DD> -<DT><A name="challenge">Challenge-response authentication</A></DT> -<DD>An<A href="#authentication"> authentication</A> system in which one - player generates a<A href="#random"> random number</A>, encrypts it and - sends the result as a challenge. The other player decrypts and sends - back the result. If the result is correct, that proves to the first - player that the second player knew the appropriate secret, required for - the decryption. Variations on this technique exist using<A href="#public"> - public key</A> or<A href="#symmetric"> symmetric</A> cryptography. Some - provide two-way authentication, assuring each player of the other's - identity. -<P>This is more secure than passwords against two simple attacks:</P> -<UL> -<LI>If cleartext passwords are sent across the wire (e.g. for telnet), - an eavesdropper can grab them. The attacker may even be able to break - into other systems if the user has chosen the same password for them.</LI> -<LI>If an encrypted password is sent, an attacker can record the - encrypted form and use it later. This is called a replay attack.</LI> -</UL> -<P>A challenge-response system never sends a password, either cleartext - or encrypted. An attacker cannot record the response to one challenge - and use it as a response to a later challenge. The random number is - different each time.</P> -<P>Of course an attacker might still try to break the cryptographic - algorithm used, or the<A href="#random"> random number</A> generator.</P> -</DD> -<DT><A name="mode">Cipher Modes</A></DT> -<DD>Different ways of using a block cipher when encrypting multiple - blocks. -<P>Four standard modes were defined for<A href="#DES"> DES</A> in<A href="#FIPS"> - FIPS</A> 81. They can actually be applied with any block cipher.</P> -<TABLE><TBODY></TBODY> -<TR><TD></TD><TD><A href="#ECB">ECB</A></TD><TD>Electronic CodeBook</TD><TD> -encrypt each block independently</TD></TR> -<TR><TD></TD><TD><A href="#CBC">CBC</A></TD><TD>Cipher Block Chaining -<BR></TD><TD>XOR previous block ciphertext into new block plaintext - before encrypting new block</TD></TR> -<TR><TD></TD><TD>CFB</TD><TD>Cipher FeedBack</TD><TD></TD></TR> -<TR><TD></TD><TD>OFB</TD><TD>Output FeedBack</TD><TD></TD></TR> -</TABLE> -<P><A href="#IPSEC">IPsec</A> uses<A href="#CBC"> CBC</A> mode since - this is only marginally slower than<A href="#ECB"> ECB</A> and is more - secure. In ECB mode the same plaintext always encrypts to the same - ciphertext, unless the key is changed. In CBC mode, this does not - occur.</P> -<P>Various other modes are also possible, but none of them are used in - IPsec.</P> -</DD> -<DT><A name="ciphertext">Ciphertext</A></DT> -<DD>The encrypted output of a cipher, as opposed to the unencrypted<A href="#plaintext"> - plaintext</A> input.</DD> -<DT><A href="http://www.cisco.com">Cisco</A></DT> -<DD>A vendor of routers, hubs and related products. Their IPsec products - interoperate with Linux FreeS/WAN; see our<A href="#cisco"> interop</A> - section.</DD> -<DT><A name="client">Client</A></DT> -<DD>This term has at least two distinct uses in discussing IPsec: -<UL> -<LI>The<STRONG> clients of an IPsec gateway</STRONG> are the machines it - protects, typically on one or more subnets behind the gateway. In this - usage, all the machines on an office network are clients of that - office's IPsec gateway. Laptop or home machines connecting to the - office, however, are<EM> not</EM> clients of that gateway. They are - remote gateways, running the other end of an IPsec connection. Each of - them is also its own client.</LI> -<LI><STRONG>IPsec client software</STRONG> is used to describe software - which runs on various standalone machines to let them connect to IPsec - networks. In this usage, a laptop or home machine connecting to the - office is a client, and the office gateway is the server.</LI> -</UL> -<P>We generally use the term in the first sense. Vendors of Windows - IPsec solutions often use it in the second. See this<A href="interop.html#client.server"> - discussion</A>.</P> -</DD> -<DT><A name="cc">Common Criteria</A></DT> -<DD>A set of international security classifications which are replacing - the old US<A href="#rainbow"> Rainbow Book</A> standards and similar - standards in other countries. -<P>Web references include this<A href="http://csrc.nist.gov/cc"> US - government site</A> and this<A href="http://www.commoncriteria.org"> - global home page</A>.</P> -</DD> -<DT>Conventional cryptography</DT> -<DD>See<A href="#symmetric"> symmetric cryptography</A></DD> -<DT><A name="collision">Collision resistance</A></DT> -<DD>The property of a<A href="#digest"> message digest</A> algorithm - which makes it hard for an attacker to find or construct two inputs - which hash to the same output.</DD> -<DT>Copyleft</DT> -<DD>see GNU<A href="#GPL"> General Public License</A></DD> -<DT><A name="CSE">CSE</A></DT> -<DD><A href="http://www.cse-cst.gc.ca/">Communications Security - Establishment</A>, the Canadian organisation for<A href="#SIGINT"> - signals intelligence</A>.</DD> -<DT><A name="D">D</A></DT> -<DT><A name="DARPA">DARPA (sometimes just ARPA)</A></DT> -<DD>The US government's<B> D</B>efense<B> A</B>dvanced<B> R</B>esearch<B> - P</B>rojects<B> A</B>gency. Projects they have funded over the years - have included the Arpanet which evolved into the Internet, the TCP/IP - protocol suite (as a replacement for the original Arpanet suite), the - Berkeley 4.x BSD Unix projects, and<A href="#SDNS"> Secure DNS</A>. -<P>For current information, see their<A href="http://www.darpa.mil/ito"> - web site</A>.</P> -</DD> -<DT><A name="DOS">Denial of service (DoS) attack</A></DT> -<DD>An attack that aims at denying some service to legitimate users of a - system, rather than providing a service to the attacker. -<UL> -<LI>One variant is a flooding attack, overwhelming the system with too - many packets, to much email, or whatever.</LI> -<LI>A closely related variant is a resource exhaustion attack. For - example, consider a "TCP SYN flood" attack. Setting up a TCP connection - involves a three-packet exchange: -<UL> -<LI>Initiator: Connection please (SYN)</LI> -<LI>Responder: OK (ACK)</LI> -<LI>Initiator: OK here too</LI> -</UL> -<P>If the attacker puts bogus source information in the first packet, - such that the second is never delivered, the responder may wait a long - time for the third to come back. If responder has already allocated - memory for the connection data structures, and if many of these bogus - packets arrive, the responder may run out of memory.</P> -</LI> -<LI>Another variant is to feed the system undigestible data, hoping to - make it sick. For example, IP packets are limited in size to 64K bytes - and a fragment carries information on where it starts within that 64K - and how long it is. The "ping of death" delivers fragments that say, - for example, that they start at 60K and are 20K long. Attempting to - re-assemble these without checking for overflow can be fatal.</LI> -</UL> -<P>The two example attacks discussed were both quite effective when - first discovered, capable of crashing or disabling many operating - systems. They were also well-publicised, and today far fewer systems - are vulnerable to them.</P> -</DD> -<DT><A name="DES">DES</A></DT> -<DD>The<B> D</B>ata<B> E</B>ncryption<B> S</B>tandard, a<A href="#block"> - block cipher</A> with 64-bit blocks and a 56-bit key. Probably the most - widely used<A href="#symmetric"> symmetric cipher</A> ever devised. DES - has been a US government standard for their own use (only for - unclassified data), and for some regulated industries such as banking, - since the late 70's. It is now being replaced by<A href="#AES"> AES</A> -. -<P><A href="#desnotsecure">DES is seriously insecure against current - attacks.</A></P> -<P><A href="#FreeSWAN">Linux FreeS/WAN</A> does not include DES, even - though the RFCs specify it.<B> We strongly recommend that single DES - not be used.</B></P> -<P>See also<A href="#3DES"> 3DES</A> and<A href="#DESX"> DESX</A>, - stronger ciphers based on DES.</P> -</DD> -<DT><A name="DESX">DESX</A></DT> -<DD>An improved<A href="#DES"> DES</A> suggested by Ron Rivest of RSA - Data Security. It XORs extra key material into the text before and - after applying the DES cipher. -<P>This is not required by the<A href="#IPSEC"> IPsec</A> RFCs and not - currently used in<A href="#FreeSWAN"> Linux FreeS/WAN</A>. DESX would - be the easiest additional transform to add; there would be very little - code to write. It would be much faster than 3DES and almost certainly - more secure than DES. However, since it is not in the RFCs other IPsec - implementations cannot be expected to have it.</P> -</DD> -<DT>DH</DT> -<DD>see<A href="#DH"> Diffie-Hellman</A></DD> -<DT><A name="DHCP">DHCP</A></DT> -<DD><STRONG>D</STRONG>ynamic<STRONG> H</STRONG>ost<STRONG> C</STRONG> -onfiguration<STRONG> P</STRONG>rotocol, a method of assigning<A href="#dynamic"> - dynamic IP addresses</A>, and providing additional information such as - addresses of DNS servers and of gateways. See this<A href="http://www.dhcp.org"> - DHCP resource page.</A></DD> -<DT><A name="DH">Diffie-Hellman (DH) key exchange protocol</A></DT> -<DD>A protocol that allows two parties without any initial shared secret - to create one in a manner immune to eavesdropping. Once they have done - this, they can communicate privately by using that shared secret as a - key for a block cipher or as the basis for key exchange. -<P>The protocol is secure against all<A href="#passive"> passive attacks</A> -, but it is not at all resistant to active<A href="#middle"> - man-in-the-middle attacks</A>. If a third party can impersonate Bob to - Alice and vice versa, then no useful secret can be created. - Authentication of the participants is a prerequisite for safe - Diffie-Hellman key exchange. IPsec can use any of several<A href="#authentication"> - authentication</A> mechanisims. Those supported by FreeS/WAN are - discussed in our<A href="#choose"> configuration</A> section.</P> -<P>The Diffie-Hellman key exchange is based on the<A href="#dlog"> - discrete logarithm</A> problem and is secure unless someone finds an - efficient solution to that problem.</P> -<P>Given a prime<VAR> p</VAR> and generator<VAR> g</VAR> (explained - under<A href="#dlog"> discrete log</A> below), Alice:</P> -<UL> -<LI>generates a random number<VAR> a</VAR></LI> -<LI>calculates<VAR> A = g^a modulo p</VAR></LI> -<LI>sends<VAR> A</VAR> to Bob</LI> -</UL> -<P>Meanwhile Bob:</P> -<UL> -<LI>generates a random number<VAR> b</VAR></LI> -<LI>calculates<VAR> B = g^b modulo p</VAR></LI> -<LI>sends<VAR> B</VAR> to Alice</LI> -</UL> -<P>Now Alice and Bob can both calculate the shared secret<VAR> s = - g^(ab)</VAR>. Alice knows<VAR> a</VAR> and<VAR> B</VAR>, so she - calculates<VAR> s = B^a</VAR>. Bob knows<VAR> A</VAR> and<VAR> b</VAR> - so he calculates<VAR> s = A^b</VAR>.</P> -<P>An eavesdropper will know<VAR> p</VAR> and<VAR> g</VAR> since these - are made public, and can intercept<VAR> A</VAR> and<VAR> B</VAR> but, - short of solving the<A href="#dlog"> discrete log</A> problem, these do - not let him or her discover the secret<VAR> s</VAR>.</P> -</DD> -<DT><A name="signature">Digital signature</A></DT> -<DD>Sender: -<UL> -<LI>calculates a<A href="#digest"> message digest</A> of a document</LI> -<LI>encrypts the digest with his or her private key, using some<A href="#public"> - public key cryptosystem</A>.</LI> -<LI>attaches the encrypted digest to the document as a signature</LI> -</UL> -<P>Receiver:</P> -<UL> -<LI>calculates a digest of the document (not including the signature)</LI> -<LI>decrypts the signature with the signer's public key</LI> -<LI>verifies that the two results are identical</LI> -</UL> -<P>If the public-key system is secure and the verification succeeds, - then the receiver knows</P> -<UL> -<LI>that the document was not altered between signing and verification</LI> -<LI>that the signer had access to the private key</LI> -</UL> -<P>Such an encrypted message digest can be treated as a signature since - it cannot be created without<EM> both</EM> the document<EM> and</EM> - the private key which only the sender should possess. The<A href="#legal"> - legal issues</A> are complex, but several countries are moving in the - direction of legal recognition for digital signatures.</P> -</DD> -<DT><A name="dlog">discrete logarithm problem</A></DT> -<DD>The problem of finding logarithms in a finite field. Given a field - defintion (such definitions always include some operation analogous to - multiplication) and two numbers, a base and a target, find the power - which the base must be raised to in order to yield the target. -<P>The discrete log problem is the basis of several cryptographic - systems, including the<A href="#DH"> Diffie-Hellman</A> key exchange - used in the<A href="#IKE"> IKE</A> protocol. The useful property is - that exponentiation is relatively easy but the inverse operation, - finding the logarithm, is hard. The cryptosystems are designed so that - the user does only easy operations (exponentiation in the field) but an - attacker must solve the hard problem (discrete log) to crack the - system.</P> -<P>There are several variants of the problem for different types of - field. The IKE/Oakley key determination protocol uses two variants, - either over a field modulo a prime or over a field defined by an - elliptic curve. We give an example modulo a prime below. For the - elliptic curve version, consult an advanced text such as<A href="#handbook"> - Handbook of Applied Cryptography</A>.</P> -<P>Given a prime<VAR> p</VAR>, a generator<VAR> g</VAR> for the field - modulo that prime, and a number<VAR> x</VAR> in the field, the problem - is to find<VAR> y</VAR> such that<VAR> g^y = x</VAR>.</P> -<P>For example, let p = 13. The field is then the integers from 0 to 12. - Any integer equals one of these modulo 13. That is, the remainder when - any integer is divided by 13 must be one of these.</P> -<P>2 is a generator for this field. That is, the powers of two modulo 13 - run through all the non-zero numbers in the field. Modulo 13 we have:</P> -<PRE> y x - 2^0 == 1 - 2^1 == 2 - 2^2 == 4 - 2^3 == 8 - 2^4 == 3 that is, the remainder from 16/13 is 3 - 2^5 == 6 the remainder from 32/13 is 6 - 2^6 == 12 and so on - 2^7 == 11 - 2^8 == 9 - 2^9 == 5 - 2^10 == 10 - 2^11 == 7 - 2^12 == 1</PRE> -<P>Exponentiation in such a field is not difficult. Given, say,<NOBR><VAR> - y = 11</VAR>,calculating<NOBR><VAR> x = 7</VAR>is straightforward. One - method is just to calculate<NOBR><VAR> 2^11 = 2048</VAR>,then<NOBR><VAR> - 2048 mod 13 == 7</VAR>.When the field is modulo a large prime (say a - few 100 digits) you need a silghtly cleverer method and even that is - moderately expensive in computer time, but the calculation is still not - problematic in any basic way.</P> -<P>The discrete log problem is the reverse. In our example, given<NOBR><VAR> - x = 7</VAR>,find the logarithm<NOBR><VAR> y = 11</VAR>.When the field - is modulo a large prime (or is based on a suitable elliptic curve), - this is indeed problematic. No solution method that is not - catastrophically expensive is known. Quite a few mathematicians have - tackled this problem. No efficient method has been found and - mathematicians do not expect that one will be. It seems likely no - efficient solution to either of the main variants the discrete log - problem exists.</P> -<P>Note, however, that no-one has proven such methods do not exist. If a - solution to either variant were found, the security of any crypto - system using that variant would be destroyed. This is one reason<A href="#IKE"> - IKE</A> supports two variants. If one is broken, we can switch to the - other.</P> -</DD> -<DT><A name="discretionary">discretionary access control</A></DT> -<DD>access control mechanisms controlled by the user, for example Unix - rwx file permissions. These contrast with<A href="#mandatory"> - mandatory access controls</A>.</DD> -<DT><A name="DNS">DNS</A></DT> -<DD><B>D</B>omain<B> N</B>ame<B> S</B>ervice, a distributed database - through which names are associated with numeric addresses and other - information in the Internet Protocol Suite. See also the<A href="#dns.background"> - DNS background</A> section of our documentation.</DD> -<DT>DOS attack</DT> -<DD>see<A href="#DOS"> Denial Of Service</A> attack</DD> -<DT><A name="dynamic">dynamic IP address</A></DT> -<DD>an IP address which is automatically assigned, either by<A href="#DHCP"> - DHCP</A> or by some protocol such as<A href="#PPP"> PPP</A> or<A href="#PPPoE"> - PPPoE</A> which the machine uses to connect to the Internet. This is - the opposite of a<A href="#static"> static IP address</A>, pre-set on - the machine itself.</DD> -<DT><A name="E">E</A></DT> -<DT><A name="EAR">EAR</A></DT> -<DD>The US government's<B> E</B>xport<B> A</B>dministration<B> R</B> -egulations, administered by the<A href="#BXA"> Bureau of Export - Administration</A>. These have replaced the earlier<A href="#ITAR"> - ITAR</A> regulations as the controls on export of cryptography.</DD> -<DT><A name="ECB">ECB mode</A></DT> -<DD><B>E</B>lectronic<B> C</B>ode<B>B</B>ook mode, the simplest way to - use a block cipher. See<A href="#mode"> Cipher Modes</A>.</DD> -<DT><A name="EDE">EDE</A></DT> -<DD>The sequence of operations normally used in either the three-key - variant of<A href="#3DES"> triple DES</A> used in<A href="#IPSEC"> - IPsec</A> or the<A href="#2key"> two-key</A> variant used in some other - systems. -<P>The sequence is:</P> -<UL> -<LI><B>E</B>ncrypt with key1</LI> -<LI><B>D</B>ecrypt with key2</LI> -<LI><B>E</B>ncrypt with key3</LI> -</UL> -<P>For the two-key version, key1=key3.</P> -<P>The "advantage" of this EDE order of operations is that it makes it - simple to interoperate with older devices offering only single DES. Set - key1=key2=key3 and you have the worst of both worlds, the overhead of - triple DES with the "security" of single DES. Since both the<A href="#desnotsecure"> - security of single DES</A> and the overheads of triple DES are - seriously inferior to many other ciphers, this is a spectacularly - dubious "advantage".</P> -</DD> -<DT><A name="Entrust">Entrust</A></DT> -<DD>A Canadian company offerring enterprise<A href="#PKI"> PKI</A> - products using<A href="#CAST128"> CAST-128</A> symmetric crypto,<A href="#RSA"> - RSA</A> public key and<A href="#X509"> X.509</A> directories.<A href="http://www.entrust.com"> - Web site</A></DD> -<DT><A name="EFF">EFF</A></DT> -<DD><A href="http://www.eff.org">Electronic Frontier Foundation</A>, an - advocacy group for civil rights in cyberspace.</DD> -<DT><A name="encryption">Encryption</A></DT> -<DD>Techniques for converting a readable message (<A href="#plaintext"> -plaintext</A>) into apparently random material (<A href="#ciphertext"> -ciphertext</A>) which cannot be read if intercepted. A key is required - to read the message. -<P>Major variants include<A href="#symmetric"> symmetric</A> encryption - in which sender and receiver use the same secret key and<A href="#public"> - public key</A> methods in which the sender uses one of a matched pair - of keys and the receiver uses the other. Many current systems, - including<A href="#IPSEC"> IPsec</A>, are<A href="#hybrid"> hybrids</A> - combining the two techniques.</P> -</DD> -<DT><A name="ESP">ESP</A></DT> -<DD><B>E</B>ncapsulated<B> S</B>ecurity<B> P</B>ayload, the<A href="#IPSEC"> - IPsec</A> protocol which provides<A href="#encryption"> encryption</A>. - It can also provide<A href="#authentication"> authentication</A> - service and may be used with null encryption (which we do not - recommend). For details see our<A href="#ESP.ipsec"> IPsec</A> document - and/or RFC 2406.</DD> -<DT><A name="#extruded">Extruded subnet</A></DT> -<DD>A situation in which something IP sees as one network is actually in - two or more places. -<P>For example, the Internet may route all traffic for a particular - company to that firm's corporate gateway. It then becomes the company's - problem to get packets to various machines on their<A href="#subnet"> - subnets</A> in various departments. They may decide to treat a branch - office like a subnet, giving it IP addresses "on" their corporate net. - This becomes an extruded subnet.</P> -<P>Packets bound for it are delivered to the corporate gateway, since as - far as the outside world is concerned, that subnet is part of the - corporate network. However, instead of going onto the corporate LAN (as - they would for, say, the accounting department) they are then - encapsulated and sent back onto the Internet for delivery to the branch - office.</P> -<P>For information on doing this with Linux FreeS/WAN, look in our<A href="#extruded.config"> - advanced configuration</A> section.</P> -</DD> -<DT>Exhaustive search</DT> -<DD>See<A href="#brute"> brute force attack</A>.</DD> -<DT><A name="F">F</A></DT> -<DT><A name="FIPS">FIPS</A></DT> -<DD><B>F</B>ederal<B> I</B>nformation<B> P</B>rocessing<B> S</B>tandard, - the US government's standards for products it buys. These are issued by<A -href="#NIST"> NIST</A>. Among other things,<A href="#DES"> DES</A> and<A href="#SHA"> - SHA</A> are defined in FIPS documents. NIST have a<A href="http://www.itl.nist.gov/div897/pubs"> - FIPS home page</A>.</DD> -<DT><A name="FSF">Free Software Foundation (FSF)</A></DT> -<DD>An organisation to promote free software, free in the sense of these - quotes from their web pages</DD> -<DD><BLOCKQUOTE> "Free software" is a matter of liberty, not price. To - understand the concept, you should think of "free speech", not "free - beer." -<P>"Free software" refers to the users' freedom to run, copy, - distribute, study, change and improve the software.</P> -</BLOCKQUOTE> -<P>See also<A href="#GNU"> GNU</A>,<A href="#GPL"> GNU General Public - License</A>, and<A href="http://www.fsf.org"> the FSF site</A>.</P> -</DD> -<DT>FreeS/WAN</DT> -<DD>see<A href="#FreeSWAN"> Linux FreeS/WAN</A></DD> -<DT><A name="fullnet">Fullnet</A></DT> -<DD>The CIDR block containing all IPs of its IP version. The<A HREF="#IPv4"> - IPv4</A> fullnet is written 0.0.0.0/0. Also known as "all" and - "default", fullnet may be used in a routing table to specify a default - route, and in a FreeS/WAN<A HREF="#policygroups"> policy group</A> file - to specify a default IPsec policy.</DD> -<DT>FSF</DT> -<DD>see<A href="#FSF"> Free software Foundation</A></DD> -<DT><A name="G">G</A></DT> -<DT><A name="GCHQ">GCHQ</A></DT> -<DD><A href="http://www.gchq.gov.uk">Government Communications - Headquarters</A>, the British organisation for<A href="#SIGINT"> - signals intelligence</A>.</DD> -<DT>generator of a prime field</DT> -<DD>see<A href="#dlog"> discrete logarithm problem</A></DD> -<DT><A name="GILC">GILC</A></DT> -<DD><A href="http://www.gilc.org">Global Internet Liberty Campaign</A>, - an international organisation advocating, among other things, free - availability of cryptography. They have a<A href="http://www.gilc.org/crypto/wassenaar"> - campaign</A> to remove cryptographic software from the<A href="#Wassenaar.gloss"> - Wassenaar Arrangement</A>.</DD> -<DT>Global Internet Liberty Campaign</DT> -<DD>see<A href="#GILC"> GILC</A>.</DD> -<DT><A name="GTR">Global Trust Register</A></DT> -<DD>An attempt to create something like a<A href="#rootCA"> root CA</A> - for<A href="#PGP"> PGP</A> by publishing both<A href="#GTR"> as a book</A> - and<A href="http://www.cl.cam.ac.uk/Research/Security/Trust-Register"> - on the web</A> the fingerprints of a set of verified keys for - well-known users and organisations.</DD> -<DT><A name="GMP">GMP</A></DT> -<DD>The<B> G</B>NU<B> M</B>ulti-<B>P</B>recision library code, used in<A href="#FreeSWAN"> - Linux FreeS/WAN</A> by<A href="#Pluto"> Pluto</A> for<A href="#public"> - public key</A> calculations. See the<A href="http://www.swox.com/gmp"> - GMP home page</A>.</DD> -<DT><A name="GNU">GNU</A></DT> -<DD><B>G</B>NU's<B> N</B>ot<B> U</B>nix, the<A href="#FSF"> Free - Software Foundation's</A> project aimed at creating a free system with - at least the capabilities of Unix.<A href="#Linux"> Linux</A> uses GNU - utilities extensively.</DD> -<DT><A name="#GOST">GOST</A></DT> -<DD>a Soviet government standard<A href="#block"> block cipher</A>.<A href="#schneier"> - Applied Cryptography</A> has details.</DD> -<DT>GPG</DT> -<DD>see<A href="#GPG"> GNU Privacy Guard</A></DD> -<DT><A name="GPL">GNU General Public License</A>(GPL, copyleft)</DT> -<DD>The license developed by the<A href="#FSF"> Free Software Foundation</A> - under which<A href="#Linux"> Linux</A>,<A href="#FreeSWAN"> Linux - FreeS/WAN</A> and many other pieces of software are distributed. The - license allows anyone to redistribute and modify the code, but forbids - anyone from distributing executables without providing access to source - code. For more details see the file<A href="../COPYING"> COPYING</A> - included with GPLed source distributions, including ours, or<A href="http://www.fsf.org/copyleft/gpl.html"> - the GNU site's GPL page</A>.</DD> -<DT><A name="GPG">GNU Privacy Guard</A></DT> -<DD>An open source implementation of Open<A href="#PGP"> PGP</A> as - defined in RFC 2440. See their<A href="http://www.gnupg.org"> web site</A> -</DD> -<DT>GPL</DT> -<DD>see<A href="#GPL"> GNU General Public License</A>.</DD> -<DT><A name="H">H</A></DT> -<DT><A name="hash">Hash</A></DT> -<DD>see<A href="#digest"> message digest</A></DD> -<DT><A name="HMAC">Hashed Message Authentication Code (HMAC)</A></DT> -<DD>using keyed<A href="#digest"> message digest</A> functions to - authenticate a message. This differs from other uses of these - functions: -<UL> -<LI>In normal usage, the hash function's internal variable are - initialised in some standard way. Anyone can reproduce the hash to - check that the message has not been altered.</LI> -<LI>For HMAC usage, you initialise the internal variables from the key. - Only someone with the key can reproduce the hash. A successful check of - the hash indicates not only that the message is unchanged but also that - the creator knew the key.</LI> -</UL> -<P>The exact techniques used in<A href="#IPSEC"> IPsec</A> are defined - in RFC 2104. They are referred to as HMAC-MD5-96 and HMAC-SHA-96 - because they output only 96 bits of the hash. This makes some attacks - on the hash functions harder.</P> -</DD> -<DT>HMAC</DT> -<DD>see<A href="#HMAC"> Hashed Message Authentication Code</A></DD> -<DT>HMAC-MD5-96</DT> -<DD>see<A href="#HMAC"> Hashed Message Authentication Code</A></DD> -<DT>HMAC-SHA-96</DT> -<DD>see<A href="#HMAC"> Hashed Message Authentication Code</A></DD> -<DT><A name="hybrid">Hybrid cryptosystem</A></DT> -<DD>A system using both<A href="#public"> public key</A> and<A href="#symmetric"> - symmetric cipher</A> techniques. This works well. Public key methods - provide key management and<A href="#signature"> digital signature</A> - facilities which are not readily available using symmetric ciphers. The - symmetric cipher, however, can do the bulk of the encryption work much - more efficiently than public key methods.</DD> -<DT><A name="I">I</A></DT> -<DT><A name="IAB">IAB</A></DT> -<DD><A href="http://www.iab.org/iab">Internet Architecture Board</A>.</DD> -<DT><A name="ICMP.gloss">ICMP</A></DT> -<DD><STRONG>I</STRONG>nternet<STRONG> C</STRONG>ontrol<STRONG> M</STRONG> -essage<STRONG> P</STRONG>rotocol. This is used for various IP-connected - devices to manage the network.</DD> -<DT><A name="IDEA">IDEA</A></DT> -<DD><B>I</B>nternational<B> D</B>ata<B> E</B>ncrypion<B> A</B>lgorithm, - developed in Europe as an alternative to exportable American ciphers - such as<A href="#DES"> DES</A> which were<A href="#desnotsecure"> too - weak for serious use</A>. IDEA is a<A href="#block"> block cipher</A> - using 64-bit blocks and 128-bit keys, and is used in products such as<A href="#PGP"> - PGP</A>. -<P>IDEA is not required by the<A href="#IPSEC"> IPsec</A> RFCs and not - currently used in<A href="#FreeSWAN"> Linux FreeS/WAN</A>.</P> -<P>IDEA is patented and, with strictly limited exceptions for personal - use, using it requires a license from<A href="http://www.ascom.com"> - Ascom</A>.</P> -</DD> -<DT><A name="IEEE">IEEE</A></DT> -<DD><A href="http://www.ieee.org">Institute of Electrical and Electronic - Engineers</A>, a professional association which, among other things, - sets some technical standards</DD> -<DT><A name="IESG">IESG</A></DT> -<DD><A href="http://www.iesg.org">Internet Engineering Steering Group</A> -.</DD> -<DT><A name="IETF">IETF</A></DT> -<DD><A href="http://www.ietf.org">Internet Engineering Task Force</A>, - the umbrella organisation whose various working groups make most of the - technical decisions for the Internet. The IETF<A href="http://www.ietf.org/html.charters/ipsec-charter.html"> - IPsec working group</A> wrote the<A href="#RFC"> RFCs</A> we are - implementing.</DD> -<DT><A name="IKE">IKE</A></DT> -<DD><B>I</B>nternet<B> K</B>ey<B> E</B>xchange, based on the<A href="#DH"> - Diffie-Hellman</A> key exchange protocol. For details, see RFC 2409 and - our<A href="ipsec.html"> IPsec</A> document. IKE is implemented in<A href="#FreeSWAN"> - Linux FreeS/WAN</A> by the<A href="#Pluto"> Pluto daemon</A>.</DD> -<DT>IKE v2</DT> -<DD>A proposed replacement for<A href="#IKE"> IKE</A>. There are other - candidates, such as<A href="#JFK"> JFK</A>, and at time of writing - (March 2002) the choice between them has not yet been made and does not - appear imminent.</DD> -<DT><A name="iOE">iOE</A></DT> -<DD>See<A HREF="#initiate-only"> Initiate-only opportunistic encryption</A> -.</DD> -<DT><A name="IP">IP</A></DT> -<DD><B>I</B>nternet<B> P</B>rotocol.</DD> -<DT><A name="masq">IP masquerade</A></DT> -<DD>A mostly obsolete term for a method of allowing multiple machines to - communicate over the Internet when only one IP address is available for - their use. The more current term is Network Address Translation or<A href="#NAT.gloss"> - NAT</A>.</DD> -<DT><A name="IPng">IPng</A></DT> -<DD>"IP the Next Generation", see<A href="#ipv6.gloss"> IPv6</A>.</DD> -<DT><A name="IPv4">IPv4</A></DT> -<DD>The current version of the<A href="#IP"> Internet protocol suite</A> -.</DD> -<DT><A name="ipv6.gloss">IPv6 (IPng)</A></DT> -<DD>Version six of the<A href="#IP"> Internet protocol suite</A>, - currently being developed. It will replace the current<A href="#IPv4"> - version four</A>. IPv6 has<A href="#IPSEC"> IPsec</A> as a mandatory - component. -<P>See this<A href="http://playground.sun.com/pub/ipng/html/ipng-main.html"> - web site</A> for more details, and our<A href="#ipv6"> compatibility</A> - document for information on FreeS/WAN and the Linux implementation of - IPv6.</P> -</DD> -<DT><A name="IPSEC">IPsec</A> or IPSEC</DT> -<DD><B>I</B>nternet<B> P</B>rotocol<B> SEC</B>urity, security functions - (<A href="#authentication">authentication</A> and<A href="#encryption"> - encryption</A>) implemented at the IP level of the protocol stack. It - is optional for<A href="#IPv4"> IPv4</A> and mandatory for<A href="#ipv6.gloss"> - IPv6</A>. -<P>This is the standard<A href="#FreeSWAN"> Linux FreeS/WAN</A> is - implementing. For more details, see our<A href="ipsec.html"> IPsec - Overview</A>. For the standards, see RFCs listed in our<A href="#RFC"> - RFCs document</A>.</P> -</DD> -<DT><A name="IPX">IPX</A></DT> -<DD>Novell's Netware protocol tunnelled over an IP link. Our<A href="#user.scripts"> - firewalls</A> document includes an example of using this through an - IPsec tunnel.</DD> -<DT><A name="ISAKMP">ISAKMP</A></DT> -<DD><B>I</B>nternet<B> S</B>ecurity<B> A</B>ssociation and<B> K</B>ey<B> - M</B>anagement<B> P</B>rotocol, defined in RFC 2408.</DD> -<DT><A name="ITAR">ITAR</A></DT> -<DD><B>I</B>nternational<B> T</B>raffic in<B> A</B>rms<B> R</B> -egulations, US regulations administered by the State Department which - until recently limited export of, among other things, cryptographic - technology and software. ITAR still exists, but the limits on - cryptography have now been transferred to the<A href="#EAR"> Export - Administration Regulations</A> under the Commerce Department's<A href="#BXA"> - Bureau of Export Administration</A>.</DD> -<DT>IV</DT> -<DD>see<A href="#IV"> Initialisation vector</A></DD> -<DT><A name="IV">Initialisation Vector (IV)</A></DT> -<DD>Some cipher<A href="#mode"> modes</A>, including the<A href="#CBC"> - CBC</A> mode which IPsec uses, require some extra data at the - beginning. This data is called the initialisation vector. It need not - be secret, but should be different for each message. Its function is to - prevent messages which begin with the same text from encrypting to the - same ciphertext. That might give an analyst an opening, so it is best - prevented.</DD> -<DT><A name="initiate-only">Initiate-only opportunistic encryption (iOE)</A> -</DT> -<DD>A form of<A HREF="#carpediem"> opportunistic encryption</A> (OE) in - which a host proposes opportunistic connections, but lacks the reverse - DNS records necessary to support incoming opportunistic connection - requests. Common among hosts on cable or pppoe connections where the - system administrator does not have write access to the DNS reverse map - for the host's external IP. -<P>Configuring for initiate-only opportunistic encryption is described - in our<A href="#opp.client"> quickstart</A> document.</P> -</DD> -<DT><A name="J">J</A></DT> -<DT><A name="JFK">JFK</A></DT> -<DD><STRONG>J</STRONG>ust<STRONG> F</STRONG>ast<STRONG> K</STRONG>eying, - a proposed simpler replacement for<A href="#IKE"> IKE.</A></DD> -<DT><A name="K">K</A></DT> -<DT><A name="kernel">Kernel</A></DT> -<DD>The basic part of an operating system (e.g. Linux) which controls - the hardware and provides services to all other programs. -<P>In the Linux release numbering system, an even second digit as in 2.<STRONG> -2</STRONG>.x indicates a stable or production kernel while an odd number - as in 2.<STRONG>3</STRONG>.x indicates an experimental or development - kernel. Most users should run a recent kernel version from the - production series. The development kernels are primarily for people - doing kernel development. Others should consider using development - kernels only if they have an urgent need for some feature not yet - available in production kernels.</P> -</DD> -<DT>Keyed message digest</DT> -<DD>See<A href="#HMAC"> HMAC</A>.</DD> -<DT>Key length</DT> -<DD>see<A href="#brute"> brute force attack</A></DD> -<DT><A name="KLIPS">KLIPS</A></DT> -<DD><B>K</B>erne<B>l</B><B> IP</B><B> S</B>ecurity, the<A href="#FreeSWAN"> - Linux FreeS/WAN</A> project's changes to the<A href="#Linux"> Linux</A> - kernel to support the<A href="#IPSEC"> IPsec</A> protocols.</DD> -<DT><A name="L">L</A></DT> -<DT><A name="LDAP">LDAP</A></DT> -<DD><B>L</B>ightweight<B> D</B>irectory<B> A</B>ccess<B> P</B>rotocol, - defined in RFCs 1777 and 1778, a method of accessing information stored - in directories. LDAP is used by several<A href="#PKI"> PKI</A> - implementations, often with X.501 directories and<A href="#X509"> X.509</A> - certificates. It may also be used by<A href="#IPSEC"> IPsec</A> to - obtain key certifications from those PKIs. This is not yet implemented - in<A href="#FreeSWAN"> Linux FreeS/WAN</A>.</DD> -<DT><A name="LIBDES">LIBDES</A></DT> -<DD>A publicly available library of<A href="#DES"> DES</A> code, written - by Eric Young, which<A href="#FreeSWAN"> Linux FreeS/WAN</A> uses in - both<A href="#KLIPS"> KLIPS</A> and<A href="#Pluto"> Pluto</A>.</DD> -<DT><A name="Linux">Linux</A></DT> -<DD>A freely available Unix-like operating system based on a kernel - originally written for the Intel 386 architecture by (then) student - Linus Torvalds. Once his 32-bit kernel was available, the<A href="#GNU"> - GNU</A> utilities made it a usable system and contributions from many - others led to explosive growth. -<P>Today Linux is a complete Unix replacement available for several CPU - architectures -- Intel, DEC/Compaq Alpha, Power PC, both 32-bit SPARC - and the 64-bit UltraSPARC, SrongARM, . . . -- with support for multiple - CPUs on some architectures.</P> -<P><A href="#FreeSWAN">Linux FreeS/WAN</A> is intended to run on all - CPUs supported by Linux and is known to work on several. See our<A href="#CPUs"> - compatibility</A> section for a list.</P> -</DD> -<DT><A name="FreeSWAN">Linux FreeS/WAN</A></DT> -<DD>Our implementation of the<A href="#IPSEC"> IPsec</A> protocols, - intended to be freely redistributable source code with<A href="#GPL"> a - GNU GPL license</A> and no constraints under US or other<A href="#exlaw"> - export laws</A>. Linux FreeS/WAN is intended to interoperate with other<A -href="#IPSEC"> IPsec</A> implementations. The name is partly taken, with - permission, from the<A href="#SWAN"> S/WAN</A> multi-vendor IPsec - compatability effort. Linux FreeS/WAN has two major components,<A href="#KLIPS"> - KLIPS</A> (KerneL IPsec Support) and the<A href="#Pluto"> Pluto</A> - daemon which manages the whole thing. -<P>See our<A href="ipsec.html"> IPsec section</A> for more detail. For - the code see our<A href="http://freeswan.org"> primary site</A> or one - of the mirror sites on<A href="#mirrors"> this list</A>.</P> -</DD> -<DT><A name="LSM">Linux Security Modules (LSM)</A></DT> -<DD>a project to create an interface in the Linux kernel that supports - plug-in modules for various security policies. -<P>This allows multiple security projects to take different approaches - to security enhancement without tying the kernel down to one particular - approach. As I understand the history, several projects were pressing - Linus to incorporate their changes, the various sets of changes were - incompatible, and his answer was more-or-less "a plague on all your - houses; I'll give you an interface, but I won't incorporate anything".</P> -<P>It seems to be working. There is a fairly active<A href="http://mail.wirex.com/mailman/listinfo/linux-security-module"> - LSM mailing list</A>, and several projects are already using the - interface.</P> -</DD> -<DT>LSM</DT> -<DD>see<A href="#LSM"> Linux Security Modules</A></DD> -<DT><A name="M">M</A></DT> -<DT><A name="list">Mailing list</A></DT> -<DD>The<A href="#FreeSWAN"> Linux FreeS/WAN</A> project has several - public email lists for bug reports and software development - discussions. See our document on<A href="mail.html"> mailing lists</A>.</DD> -<DT><A name="middle">Man-in-the-middle attack</A></DT> -<DD>An<A href="#active"> active attack</A> in which the attacker - impersonates each of the legitimate players in a protocol to the other. -<P>For example, if<A href="#alicebob"> Alice and Bob</A> are negotiating - a key via the<A href="#DH"> Diffie-Hellman</A> key agreement, and are - not using<A href="#authentication"> authentication</A> to be certain - they are talking to each other, then an attacker able to insert himself - in the communication path can deceive both players.</P> -<P>Call the attacker Mallory. For Bob, he pretends to be Alice. For - Alice, he pretends to be Bob. Two keys are then negotiated, - Alice-to-Mallory and Bob-to-Mallory. Alice and Bob each think the key - they have is Alice-to-Bob.</P> -<P>A message from Alice to Bob then goes to Mallory who decrypts it, - reads it and/or saves a copy, re-encrypts using the Bob-to-Mallory key - and sends it along to Bob. Bob decrypts successfully and sends a reply - which Mallory decrypts, reads, re-encrypts and forwards to Alice.</P> -<P>To make this attack effective, Mallory must</P> -<UL> -<LI>subvert some part of the network in some way that lets him carry out - the deception -<BR> possible targets: DNS, router, Alice or Bob's machine, mail server, - ...</LI> -<LI>beat any authentication mechanism Alice and Bob use -<BR> strong authentication defeats the attack entirely; this is why<A href="#IKE"> - IKE</A> requires authentication</LI> -<LI>work in real time, delivering messages without introducing a delay - large enough to alert the victims -<BR> not hard if Alice and Bob are using email; quite difficult in some - situations.</LI> -</UL> -<P>If he manages it, however, it is devastating. He not only gets to - read all the messages; he can alter messages, inject his own, forge - anything he likes, . . . In fact, he controls the communication - completely.</P> -</DD> -<DT><A name="mandatory">mandatory access control</A></DT> -<DD>access control mechanisims which are not settable by the user (see<A href="#discretionary"> - discretionary access control</A>), but are enforced by the system. -<P>For example, a document labelled "secret, zebra" might be readable - only by someone with secret clearance working on Project Zebra. - Ideally, the system will prevent any transfer outside those boundaries. - For example, even if you can read it, you should not be able to e-mail - it (unless the recipient is appropriately cleared) or print it (unless - certain printers are authorised for that classification).</P> -<P>Mandatory access control is a required feature for some levels of<A href="#rainbow"> - Rainbow Book</A> or<A href="#cc"> Common Criteria</A> classification, - but has not been widely used outside the military and government. There - is a good discussion of the issues in Anderson's<A href="#anderson"> - Security Engineering</A>.</P> -<P>The<A href="#SElinux"> Security Enhanced Linux</A> project is adding - mandatory access control to Linux.</P> -</DD> -<DT><A name="manual">Manual keying</A></DT> -<DD>An IPsec mode in which the keys are provided by the administrator. - In FreeS/WAN, they are stored in /etc/ipsec.conf. The alternative,<A href="#auto"> - automatic keying</A>, is preferred in most cases. See this<A href="#man-auto"> - discussion</A>.</DD> -<DT><A name="MD4">MD4</A></DT> -<DD><A href="#digest">Message Digest Algorithm</A> Four from Ron Rivest - of<A href="#RSAco"> RSA</A>. MD4 was widely used a few years ago, but - is now considered obsolete. It has been replaced by its descendants<A href="#MD5"> - MD5</A> and<A href="#SHA"> SHA</A>.</DD> -<DT><A name="MD5">MD5</A></DT> -<DD><A href="#digest">Message Digest Algorithm</A> Five from Ron Rivest - of<A href="#RSAco"> RSA</A>, an improved variant of his<A href="#MD4"> - MD4</A>. Like MD4, it produces a 128-bit hash. For details see RFC - 1321. -<P>MD5 is one of two message digest algorithms available in IPsec. The - other is<A href="#SHA"> SHA</A>. SHA produces a longer hash and is - therefore more resistant to<A href="#birthday"> birthday attacks</A>, - but this is not a concern for IPsec. The<A href="#HMAC"> HMAC</A> - method used in IPsec is secure even if the underlying hash is not - particularly strong against this attack.</P> -<P>Hans Dobbertin found a weakness in MD5, and people often ask whether - this means MD5 is unsafe for IPsec. It doesn't. The IPsec RFCs discuss - Dobbertin's attack and conclude that it does not affect MD5 as used for - HMAC in IPsec.</P> -</DD> -<DT><A name="meet">Meet-in-the-middle attack</A></DT> -<DD>A divide-and-conquer attack which breaks a cipher into two parts, - works against each separately, and compares results. Probably the best - known example is an attack on double DES. This applies in principle to - any pair of block ciphers, e.g. to an encryption system using, say, - CAST-128 and Blowfish, but we will describe it for double DES. -<P>Double DES encryption and decryption can be written:</P> -<PRE> C = E(k2,E(k1,P)) - P = D(k1,D(k2,C))</PRE> -<P>Where C is ciphertext, P is plaintext, E is encryption, D is - decryption, k1 is one key, and k2 is the other key. If we know a P, C - pair, we can try and find the keys with a brute force attack, trying - all possible k1, k2 pairs. Since each key is 56 bits, there are 2<SUP> -112</SUP> such pairs and this attack is painfully inefficient.</P> -<P>The meet-in-the middle attack re-writes the equations to calculate a - middle value M:</P> -<PRE> M = E(k1,P) - M = D(k2,C)</PRE> -<P>Now we can try some large number of D(k2,C) decryptions with various - values of k2 and store the results in a table. Then start doing E(k1,P) - encryptions, checking each result to see if it is in the table.</P> -<P>With enough table space, this breaks double DES with<NOBR> 2<SUP>56</SUP> - + 2<SUP>56</SUP> = 2<SUP>57</SUP>work. Against triple DES, you need<NOBR> - 2<SUP>56</SUP> + 2<SUP>112</SUP> ~= 2<SUP>112</SUP>.</P> -<P>The memory requirements for such attacks can be prohibitive, but - there is a whole body of research literature on methods of reducing - them.</P> -</DD> -<DT><A name="digest">Message Digest Algorithm</A></DT> -<DD>An algorithm which takes a message as input and produces a hash or - digest of it, a fixed-length set of bits which depend on the message - contents in some highly complex manner. Design criteria include making - it extremely difficult for anyone to counterfeit a digest or to change - a message without altering its digest. One essential property is<A href="#collision"> - collision resistance</A>. The main applications are in message<A href="#authentication"> - authentication</A> and<A href="#signature"> digital signature</A> - schemes. Widely used algorithms include<A href="#MD5"> MD5</A> and<A href="#SHA"> - SHA</A>. In IPsec, message digests are used for<A href="#HMAC"> HMAC</A> - authentication of packets.</DD> -<DT><A name="MTU">MTU</A></DT> -<DD><STRONG>M</STRONG>aximum<STRONG> T</STRONG>ransmission<STRONG> U</STRONG> -nit, the largest size of packet that can be sent over a link. This is - determined by the underlying network, but must be taken account of at - the IP level. -<P>IP packets, which can be up to 64K bytes each, must be packaged into - lower-level packets of the appropriate size for the underlying - network(s) and re-assembled on the other end. When a packet must pass - over multiple networks, each with its own MTU, and many of the MTUs are - unknown to the sender, this becomes a fairly complex problem. See<A href="#pathMTU"> - path MTU discovery</A> for details.</P> -<P>Often the MTU is a few hundred bytes on serial links and 1500 on - Ethernet. There are, however, serial link protocols which use a larger - MTU to avoid fragmentation at the ethernet/serial boundary, and newer - (especially gigabit) Ethernet networks sometimes support much larger - packets because these are more efficient in some applications.</P> -</DD> -<DT><A name="N">N</A></DT> -<DT><A name="NAI">NAI</A></DT> -<DD><A href="http://www.nai.com">Network Associates</A>, a conglomerate - formed from<A href="#PGPI"> PGP Inc.</A>, TIS (Trusted Information - Systems, a firewall vendor) and McAfee anti-virus products. Among other - things, they offer an IPsec-based VPN product.</DD> -<DT><A name="NAT.gloss">NAT</A></DT> -<DD><B>N</B>etwork<B> A</B>ddress<B> T</B>ranslation, a process by which - firewall machines may change the addresses on packets as they go - through. For discussion, see our<A href="#nat.background"> background</A> - section.</DD> -<DT><A name="NIST">NIST</A></DT> -<DD>The US<A href="http://www.nist.gov"> National Institute of Standards - and Technology</A>, responsible for<A href="#FIPS"> FIPS standards</A> - including<A href="#DES"> DES</A> and its replacement,<A href="#AES"> - AES</A>.</DD> -<DT><A name="nonce">Nonce</A></DT> -<DD>A<A href="#random"> random</A> value used in an<A href="#authentication"> - authentication</A> protocol.</DD> -<DT></DT> -<DT><A name="non-routable">Non-routable IP address</A></DT> -<DD>An IP address not normally allowed in the "to" or "from" IP address - field header of IP packets. -<P>Almost invariably, the phrase "non-routable address" means one of the - addresses reserved by RFC 1918 for private networks:</P> -<UL> -<LI>10.anything</LI> -<LI>172.x.anything with 16 <= x <= 31</LI> -<LI>192.168.anything</LI> -</UL> -<P>These addresses are commonly used on private networks, e.g. behind a - Linux machines doing<A href="#masq"> IP masquerade</A>. Machines within - the private network can address each other with these addresses. All - packets going outside that network, however, have these addresses - replaced before they reach the Internet.</P> -<P>If any packets using these addresses do leak out, they do not go far. - Most routers automatically discard all such packets.</P> -<P>Various other addresses -- the 127.0.0.0/8 block reserved for local - use, 0.0.0.0, various broadcast and network addresses -- cannot be - routed over the Internet, but are not normally included in the meaning - when the phrase "non-routable address" is used.</P> -</DD> -<DT><A name="NSA">NSA</A></DT> -<DD>The US<A href="http://www.nsa.gov"> National Security Agency</A>, - the American organisation for<A href="#SIGINT"> signals intelligence</A> -, the protection of US government messages and the interception and - analysis of other messages. For details, see Bamford's<A href="#puzzle"> - "The Puzzle Palace"</A>. -<P>Some<A href="http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB23/index.html"> - history of NSA</A> documents were declassified in response to a FOIA - (Freedom of Information Act) request.</P> -</DD> -<DT><A name="O">O</A></DT> -<DT><A name="oakley">Oakley</A></DT> -<DD>A key determination protocol, defined in RFC 2412.</DD> -<DT>Oakley groups</DT> -<DD>The groups used as the basis of<A href="#DH"> Diffie-Hellman</A> key - exchange in the Oakley protocol, and in<A href="#IKE"> IKE</A>. Four - were defined in the original RFC, and a fifth has been<A href="http://www.lounge.org/ike_doi_errata.html"> - added since</A>. -<P>Linux FreeS/WAN currently supports the three groups based on finite - fields modulo a prime (Groups 1, 2 and 5) and does not support the - elliptic curve groups (3 and 4). For a description of the difference of - the types, see<A href="#dlog"> discrete logarithms</A>.</P> -</DD> -<DT><A name="OTP">One time pad</A></DT> -<DD>A cipher in which the key is: -<UL> -<LI>as long as the total set of messages to be enciphered</LI> -<LI>absolutely<A href="#random"> random</A></LI> -<LI>never re-used</LI> -</UL> -<P>Given those three conditions, it can easily be proved that the cipher - is perfectly secure, in the sense that an attacker with intercepted - message in hand has no better chance of guessing the message than an - attacker who has not intercepted the message and only knows the message - length. No such proof exists for any other cipher.</P> -<P>There are, however, several problems with this "perfect" cipher.</P> -<P>First, it is<STRONG> wildly impractical</STRONG> for most - applications. Key management is at best difficult, often completely - impossible.</P> -<P>Second, it is<STRONG> extremely fragile</STRONG>. Small changes which - violate the conditions listed above do not just weaken the cipher - liitle. Quite often they destroy its security completely.</P> -<UL> -<LI>Re-using the pad weakens the cipher to the point where it can be - broken with pencil and paper. With a computer, the attack is trivially - easy.</LI> -<LI>Using<EM> anything</EM> less than truly<A href="#random"> random</A> - numbers<EM> completely</EM> invalidates the security proof.</LI> -<LI>In particular, using computer-generated pseudo-random numbers may - give an extremely weak cipher. It might also produce a good stream - cipher, if the pseudo-random generator is both well-designed and - properely seeded.</LI> -</UL> -<P>Marketing claims about the "unbreakable" security of various products - which somewhat resemble one-time pads are common. Such claims are one - of the surest signs of cryptographic<A href="#snake"> snake oil</A>; - most systems marketed with such claims are worthless.</P> -<P>Finally, even if the system is implemented and used correctly, it is<STRONG> - highly vulnerable to a substitution attack</STRONG>. If an attacker - knows some plaintext and has an intercepted message, he can discover - the pad.</P> -<UL> -<LI>This does not matter if the attacker is just a<A href="#passive"> - passive</A> eavesdropper. It gives him no plaintext he didn't already - know and we don't care that he learns a pad which we will never re-use.</LI> -<LI>However, an<A href="#active"> active</A> attacker who knows the - plaintext can recover the pad, then use it to encode with whatever he - chooses. If he can get his version delivered instead of yours, this may - be a disaster. If you send "attack at dawn", the delivered message can - be anything the same length -- perhaps "retreat to east" or "shoot - generals".</LI> -<LI>An active attacker with only a reasonable guess at the plaintext can - try the same attack. If the guess is correct, this works and the - attacker's bogus message is delivered. If the guess is wrong, a garbled - message is delivered.</LI> -</UL> -<P>In general then, despite its theoretical perfection, the one-time-pad - has very limited practical application.</P> -<P>See also the<A href="http://pubweb.nfr.net/~mjr/pubs/otpfaq/"> one - time pad FAQ</A>.</P> -</DD> -<DT><A name="carpediem">Opportunistic encryption (OE)</A></DT> -<DD>A situation in which any two IPsec-aware machines can secure their - communications, without a pre-shared secret and without a common<A href="#PKI"> - PKI</A> or previous exchange of public keys. This is one of the goals - of the Linux FreeS/WAN project, discussed in our<A href="#goals"> - introduction</A> section. -<P>Setting up for opportunistic encryption is described in our<A href="#quickstart"> - quickstart</A> document.</P> -</DD> -<DT><A name="responder">Opportunistic responder</A></DT> -<DD>A host which accepts, but does not initiate, requests for<A HREF="#carpediem"> - opportunistic encryption</A> (OE). An opportunistic responder has - enabled OE in its<A HREF="#passive.OE"> passive</A> form (pOE) only. A - web server or file server may be usefully set up as an opportunistic - responder. -<P>Configuring passive OE is described in our<A href="#policygroups"> - policy groups</A> document.</P> -</DD> -<DT><A name="orange">Orange book</A></DT> -<DD>the most basic and best known of the US government's<A href="#rainbow"> - Rainbow Book</A> series of computer security standards.</DD> -<DT><A name="P">P</A></DT> -<DT><A name="P1363">P1363 standard</A></DT> -<DD>An<A href="#IEEE"> IEEE</A> standard for public key cryptography.<A href="http://grouper.ieee.org/groups/1363"> - Web page</A>.</DD> -<DT><A name="pOE">pOE</A></DT> -<DD>See<A href="#passive.OE"> Passive opportunistic encryption</A>.</DD> -<DT><A name="passive">Passive attack</A></DT> -<DD>An attack in which the attacker only eavesdrops and attempts to - analyse intercepted messages, as opposed to an<A href="#active"> active - attack</A> in which he diverts messages or generates his own.</DD> -<DT><A name="passive.OE">Passive opportunistic encryption (pOE)</A></DT> -<DD>A form of<A HREF="#carpediem"> opportunistic encryption</A> (OE) in - which the host will accept opportunistic connection requests, but will - not initiate such requests. A host which runs OE in its passive form - only is known as an<A HREF="#responder"> opportunistic responder</A>. -<P>Configuring passive OE is described in our<A href="#policygroups"> - policy groups</A> document.</P> -</DD> -<DT><A name="pathMTU">Path MTU discovery</A></DT> -<DD>The process of discovering the largest packet size which all links - on a path can handle without fragmentation -- that is, without any - router having to break the packet up into smaller pieces to match the<A href="#MTU"> - MTU</A> of its outgoing link. -<P>This is done as follows:</P> -<UL> -<LI>originator sends the largest packets allowed by<A href="#MTU"> MTU</A> - of the first link, setting the DF (<STRONG>d</STRONG>on't<STRONG> f</STRONG> -ragment) bit in the packet header</LI> -<LI>any router which cannot send the packet on (outgoing MTU is too - small for it, and DF prevents fragmenting it to match) sends back an<A href="#ICMP.gloss"> - ICMP</A> packet reporting the problem</LI> -<LI>originator looks at ICMP message and tries a smaller size</LI> -<LI>eventually, you settle on a size that can pass all routers</LI> -<LI>thereafter, originator just sends that size and no-one has to - fragment</LI> -</UL> -<P>Since this requires co-operation of many systems, and since the next - packet may travel a different path, this is one of the trickier areas - of IP programming. Bugs that have shown up over the years have - included:</P> -<UL> -<LI>malformed ICMP messages</LI> -<LI>hosts that ignore or mishandle these ICMP messages</LI> -<LI>firewalls blocking the ICMP messages so host does not see them</LI> -</UL> -<P>Since IPsec adds a header, it increases packet size and may require - fragmentation even where incoming and outgoing MTU are equal.</P> -</DD> -<DT><A name="PFS">Perfect forward secrecy (PFS)</A></DT> -<DD>A property of systems such as<A href="#DH"> Diffie-Hellman</A> key - exchange which use a long-term key (such as the shared secret in IKE) - and generate short-term keys as required. If an attacker who acquires - the long-term key<EM> provably</EM> can -<UL> -<LI><EM>neither</EM> read previous messages which he may have archived</LI> -<LI><EM>nor</EM> read future messages without performing additional - successful attacks</LI> -</UL> -<P>then the system has PFS. The attacker needs the short-term keys in - order to read the trafiic and merely having the long-term key does not - allow him to infer those. Of course, it may allow him to conduct - another attack (such as<A href="#middle"> man-in-the-middle</A>) which - gives him some short-term keys, but he does not automatically get them - just by acquiring the long-term key.</P> -<P>See also<A href="http://sandelman.ottawa.on.ca/ipsec/1996/08/msg00123.html"> - Phil Karn's definition</A>.</P> -</DD> -<DT>PFS</DT> -<DD>see Perfect Forward Secrecy</DD> -<DT><A name="PGP">PGP</A></DT> -<DD><B>P</B>retty<B> G</B>ood<B> P</B>rivacy, a personal encryption - system for email based on public key technology, written by Phil - Zimmerman. -<P>The 2.xx versions of PGP used the<A href="#RSA"> RSA</A> public key - algorithm and used<A href="#IDEA"> IDEA</A> as the symmetric cipher. - These versions are described in RFC 1991 and in<A href="#PGP"> - Garfinkel's book</A>. Since version 5, the products from<A href="#PGPI"> - PGP Inc</A>. have used<A href="#DH"> Diffie-Hellman</A> public key - methods and<A href="#CAST128"> CAST-128</A> symmetric encryption. These - can verify signatures from the 2.xx versions, but cannot exchange - encryted messages with them.</P> -<P>An<A href="#IETF"> IETF</A> working group has issued RFC 2440 for an - "Open PGP" standard, similar to the 5.x versions. PGP Inc. staff were - among the authors. A free<A href="#GPG"> Gnu Privacy Guard</A> based on - that standard is now available.</P> -<P>For more information on PGP, including how to obtain it, see our - cryptography<A href="#tools"> links</A>.</P> -</DD> -<DT><A name="PGPI">PGP Inc.</A></DT> -<DD>A company founded by Zimmerman, the author of<A href="#PGP"> PGP</A> -, now a division of<A href="#NAI"> NAI</A>. See the<A href="http://www.pgp.com"> - corporate website</A>. Zimmerman left in 2001, and early in 2002 NAI - announced that they would no longer sell PGP.. -<P>Versions 6.5 and later of the PGP product include PGPnet, an IPsec - client for Macintosh or for Windows 95/98/NT. See our<A href="interop.html#pgpnet"> - interoperation documen</A>t.</P> -</DD> -<DT><A name="photuris">Photuris</A></DT> -<DD>Another key negotiation protocol, an alternative to<A href="#IKE"> - IKE</A>, described in RFCs 2522 and 2523.</DD> -<DT><A name="PPP">PPP</A></DT> -<DD><B>P</B>oint-to-<B>P</B>oint<B> P</B>rotocol, originally a method of - connecting over modems or serial lines, but see also PPPoE.</DD> -<DT><A name="PPPoE">PPPoE</A></DT> -<DD><B>PPP</B><B> o</B>ver<B> E</B>thernet, a somewhat odd protocol that - makes Ethernet look like a point-to-point serial link. It is widely - used for cable or ADSL Internet services, apparently mainly because it - lets the providers use access control and address assignmment - mechanisms developed for dialup networks.<A href="http://www.roaringpenguin.com"> - Roaring Penguin</A> provide a widely used Linux implementation.</DD> -<DT><A name="PPTP">PPTP</A></DT> -<DD><B>P</B>oint-to-<B>P</B>oint<B> T</B>unneling<B> P</B>rotocol, used - in some Microsoft VPN implementations. Papers discussing weaknesses in - it are on<A href="http://www.counterpane.com/publish.html"> - counterpane.com</A>. It is now largely obsolete, replaced by L2TP.</DD> -<DT><A name="PKI">PKI</A></DT> -<DD><B>P</B>ublic<B> K</B>ey<B> I</B>nfrastructure, the things an - organisation or community needs to set up in order to make<A href="#public"> - public key</A> cryptographic technology a standard part of their - operating procedures. -<P>There are several PKI products on the market. Typically they use a - hierarchy of<A href="#CA"> Certification Authorities (CAs)</A>. Often - they use<A href="#LDAP"> LDAP</A> access to<A href="#X509"> X.509</A> - directories to implement this.</P> -<P>See<A href="#web"> Web of Trust</A> for a different sort of - infrastructure.</P> -</DD> -<DT><A name="PKIX">PKIX</A></DT> -<DD><B>PKI</B> e<B>X</B>change, an<A href="#IETF"> IETF</A> standard - that allows<A href="#PKI"> PKI</A>s to talk to each other. -<P>This is required, for example, when users of a corporate PKI need to - communicate with people at client, supplier or government - organisations, any of which may have a different PKI in place. I should - be able to talk to you securely whenever:</P> -<UL> -<LI>your organisation and mine each have a PKI in place</LI> -<LI>you and I are each set up to use those PKIs</LI> -<LI>the two PKIs speak PKIX</LI> -<LI>the configuration allows the conversation</LI> -</UL> -<P>At time of writing (March 1999), this is not yet widely implemented - but is under quite active development by several groups.</P> -</DD> -<DT><A name="plaintext">Plaintext</A></DT> -<DD>The unencrypted input to a cipher, as opposed to the encrypted<A href="#ciphertext"> - ciphertext</A> output.</DD> -<DT><A name="Pluto">Pluto</A></DT> -<DD>The<A href="#FreeSWAN"> Linux FreeS/WAN</A> daemon which handles key - exchange via the<A href="#IKE"> IKE</A> protocol, connection - negotiation, and other higher-level tasks. Pluto calls the<A href="#KLIPS"> - KLIPS</A> kernel code as required. For details, see the manual page - ipsec_pluto(8).</DD> -<DT><A name="public">Public Key Cryptography</A></DT> -<DD>In public key cryptography, keys are created in matched pairs. - Encrypt with one half of a pair and only the matching other half can - decrypt it. This contrasts with<A href="#symmetric"> symmetric or - secret key cryptography</A> in which a single key known to both parties - is used for both encryption and decryption. -<P>One half of each pair, called the public key, is made public. The - other half, called the private key, is kept secret. Messages can then - be sent by anyone who knows the public key to the holder of the private - key. Encrypt with the public key and you know that only someone with - the matching private key can decrypt.</P> -<P>Public key techniques can be used to create<A href="#signature"> - digital signatures</A> and to deal with key management issues, perhaps - the hardest part of effective deployment of<A href="#symmetric"> - symmetric ciphers</A>. The resulting<A href="#hybrid"> hybrid - cryptosystems</A> use public key methods to manage keys for symmetric - ciphers.</P> -<P>Many organisations are currently creating<A href="#PKI"> PKIs, public - key infrastructures</A> to make these benefits widely available.</P> -</DD> -<DT>Public Key Infrastructure</DT> -<DD>see<A href="#PKI"> PKI</A></DD> -<DT><A name="Q">Q</A></DT> -<DT><A name="R">R</A></DT> -<DT><A name="rainbow">Rainbow books</A></DT> -<DD>A set of US government standards for evaluation of "trusted computer - systems", of which the best known was the<A href="#orange"> Orange Book</A> -. One fairly often hears references to "C2 security" or a product - "evaluated at B1". The Rainbow books define the standards referred to - in those comments. -<P>See this<A href="http://www.fas.org/irp/nsa/rainbow.htm"> reference - page</A>.</P> -<P>The Rainbow books are now mainly obsolete, replaced by the - international<A href="#cc"> Common Criteria</A> standards.</P> -</DD> -<DT><A name="random">Random</A></DT> -<DD>A remarkably tricky term, far too much so for me to attempt a - definition here. Quite a few cryptosystems have been broken via attacks - on weak random number generators, even when the rest of the system was - sound. -<P>See<A href="http://nis.nsf.net/internet/documents/rfc/rfc1750.txt"> - RFC 1750</A> for the theory.</P> -<P>See the manual pages for<A href="manpage.d/ipsec_ranbits.8.html"> - ipsec_ranbits(8)</A> and ipsec_prng(3) for more on FreeS/WAN's use of - randomness. Both depend on the random(4) device driver..</P> -<P>A couple of years ago, there was extensive mailing list discussion - (archived<A href="http://www.openpgp.net/random/index.html"> here</A> -)of Linux /dev/random and FreeS/WAN. Since then, the design of the - random(4) driver has changed considerably. Linux 2.4 kernels have the - new driver..</P> -</DD> -<DT>Raptor</DT> -<DD>A firewall product for Windows NT offerring IPsec-based VPN - services. Linux FreeS/WAN interoperates with Raptor; see our<A href="#raptor"> - interop</A> document for details. Raptor have recently merged with - Axent.</DD> -<DT><A name="RC4">RC4</A></DT> -<DD><B>R</B>ivest<B> C</B>ipher four, designed by Ron Rivest of<A href="#RSAco"> - RSA</A> and widely used. Believed highly secure with adequate key - length, but often implemented with inadequate key length to comply with - export restrictions.</DD> -<DT><A name="RC6">RC6</A></DT> -<DD><B>R</B>ivest<B> C</B>ipher six,<A href="#RSAco"> RSA</A>'s<A href="#AES"> - AES</A> candidate cipher.</DD> -<DT><A name="replay">Replay attack</A></DT> -<DD>An attack in which the attacker records data and later replays it in - an attempt to deceive the recipient.</DD> -<DT><A name="reverse">Reverse map</A></DT> -<DD>In<A href="#DNS"> DNS</A>, a table where IP addresses can be used as - the key for lookups which return a system name and/or other - information.</DD> -<DT>RFC</DT> -<DD><B>R</B>equest<B> F</B>or<B> C</B>omments, an Internet document. - Some RFCs are just informative. Others are standards. -<P>Our list of<A href="#IPSEC"> IPsec</A> and other security-related - RFCs is<A href="#RFC"> here</A>, along with information on methods of - obtaining them.</P> -</DD> -<DT><A name="rijndael">Rijndael</A></DT> -<DD>a<A href="#block"> block cipher</A> designed by two Belgian - cryptographers, winner of the US government's<A href="#AES"> AES</A> - contest to pick a replacement for<A href="#DES"> DES</A>. See the<A href="http://www.esat.kuleuven.ac.be/~rijmen/rijndael"> - Rijndael home page</A>.</DD> -<DT><A name="RIPEMD">RIPEMD</A></DT> -<DD>A<A href="#digest"> message digest</A> algorithm. The current - version is RIPEMD-160 which gives a 160-bit hash.</DD> -<DT><A name="rootCA">Root CA</A></DT> -<DD>The top level<A href="#CA"> Certification Authority</A> in a - hierachy of such authorities.</DD> -<DT><A name="routable">Routable IP address</A></DT> -<DD>Most IP addresses can be used as "to" and "from" addresses in packet - headers. These are the routable addresses; we expect routing to be - possible for them. If we send a packet to one of them, we expect (in - most cases; there are various complications) that it will be delivered - if the address is in use and will cause an<A href="#ICMP.gloss"> ICMP</A> - error packet to come back to us if not. -<P>There are also several classes of<A href="#non-routable"> - non-routable</A> IP addresses.</P> -</DD> -<DT><A name="RSA">RSA algorithm</A></DT> -<DD><B>R</B>ivest<B> S</B>hamir<B> A</B>dleman<A href="#public"> public - key</A> algorithm, named for its three inventors. It is widely used and - likely to become moreso since it became free of patent encumbrances in - September 2000. -<P>RSA can be used to provide either<A href="#encryption"> encryption</A> - or<A href="#signature"> digital signatures</A>. In IPsec, it is used - only for signatures. These provide gateway-to-gateway<A href="#authentication"> - authentication</A> for<A href="#IKE"> IKE</A> negotiations.</P> -<P>For a full explanation of the algorithm, consult one of the standard - references such as<A href="#schneier"> Applied Cryptography</A>. A - simple explanation is:</P> -<P>The great 17th century French mathematician<A href="http://www-groups.dcs.st-andrews.ac.uk/~history/Mathematicians/Fermat.html"> - Fermat</A> proved that,</P> -<P>for any prime p and number x, 0 <= x < p:</P> -<PRE> x^p == x modulo p - x^(p-1) == 1 modulo p, non-zero x - </PRE> -<P>From this it follows that if we have a pair of primes p, q and two - numbers e, d such that:</P> -<PRE> ed == 1 modulo lcm( p-1, q-1) - </PRE> - where lcm() is least common multiple, then -<BR> for all x, 0 <= x < pq: -<PRE> x^ed == x modulo pq - </PRE> -<P>So we construct such as set of numbers p, q, e, d and publish the - product N=pq and e as the public key. Using c for<A href="#ciphertext"> - ciphertext</A> and i for the input<A href="#plaintext"> plaintext</A>, - encryption is then:</P> -<PRE> c = i^e modulo N - </PRE> -<P>An attacker cannot deduce i from the cyphertext c, short of either - factoring N or solving the<A href="#dlog"> discrete logarithm</A> - problem for this field. If p, q are large primes (hundreds or thousands - of bits) no efficient solution to either problem is known.</P> -<P>The receiver, knowing the private key (N and d), can readily recover - the plaintext p since:</P> -<PRE> c^d == (i^e)^d modulo N - == i^ed modulo N - == i modulo N - </PRE> -<P>This gives an effective public key technique, with only a couple of - problems. It uses a good deal of computer time, since calculations with - large integers are not cheap, and there is no proof it is necessarily - secure since no-one has proven either factoring or discrete log cannot - be done efficiently. Quite a few good mathematicians have tried both - problems, and no-one has announced success, but there is no proof they - are insoluble.</P> -</DD> -<DT><A name="RSAco">RSA Data Security</A></DT> -<DD>A company founded by the inventors of the<A href="#RSA"> RSA</A> - public key algorithm.</DD> -<DT><A name="S">S</A></DT> -<DT><A name="SA">SA</A></DT> -<DD><B>S</B>ecurity<B> A</B>ssociation, the channel negotiated by the - higher levels of an<A href="#IPSEC"> IPsec</A> implementation (<A href="#IKE"> -IKE</A>) and used by the lower (<A href="#ESP">ESP</A> and<A href="#AH"> - AH</A>). SAs are unidirectional; you need a pair of them for two-way - communication. -<P>An SA is defined by three things -- the destination, the protocol (<A href="#AH"> -AH</A> or<A href="#ESP">ESP</A>) and the<A href="SPI"> SPI</A>, security - parameters index. It is used as an index to look up other things such - as session keys and intialisation vectors.</P> -<P>For more detail, see our section on<A href="ipsec.html"> IPsec</A> - and/or RFC 2401.</P> -</DD> -<DT><A name="SElinux">SE Linux</A></DT> -<DD><STRONG>S</STRONG>ecurity<STRONG> E</STRONG>nhanced Linux, an<A href="#NSA"> - NSA</A>-funded project to add<A href="#mandatory"> mandatory access - control</A> to Linux. See the<A href="http://www.nsa.gov/selinux"> - project home page</A>. -<P>According to their web pages, this work will include extending - mandatory access controls to IPsec tunnels.</P> -<P>Recent versions of SE Linux code use the<A href="#LSM"> Linux - Security Module</A> interface.</P> -</DD> -<DT><A name="SDNS">Secure DNS</A></DT> -<DD>A version of the<A href="#DNS"> DNS or Domain Name Service</A> - enhanced with authentication services. This is being designed by the<A href="#IETF"> - IETF</A> DNS security<A href="http://www.ietf.org/ids.by.wg/dnssec.html"> - working group</A>. Check the<A href="http://www.isc.org/bind.html"> - Internet Software Consortium</A> for information on implementation - progress and for the latest version of<A href="#BIND"> BIND</A>. - Another site has<A href="http://www.toad.com/~dnssec"> more information</A> -. -<P><A href="#IPSEC">IPsec</A> can use this plus<A href="#DH"> - Diffie-Hellman key exchange</A> to bootstrap itself. This allows<A href="#carpediem"> - opportunistic encryption</A>. Any pair of machines which can - authenticate each other via DNS can communicate securely, without - either a pre-existing shared secret or a shared<A href="#PKI"> PKI</A>.</P> -</DD> -<DT>Secret key cryptography</DT> -<DD>See<A href="#symmetric"> symmetric cryptography</A></DD> -<DT>Security Association</DT> -<DD>see<A href="#SA"> SA</A></DD> -<DT>Security Enhanced Linux</DT> -<DD>see<A href="#SElinux"> SE Linux</A></DD> -<DT><A name="sequence">Sequence number</A></DT> -<DD>A number added to a packet or message which indicates its position - in a sequence of packets or messages. This provides some security - against<A href="#replay"> replay attacks</A>. -<P>For<A href="#auto"> automatic keying</A> mode, the<A href="#IPSEC"> - IPsec</A> RFCs require that the sender generate sequence numbers for - each packet, but leave it optional whether the receiver does anything - with them.</P> -</DD> -<DT><A name="SHA">SHA</A></DT> -<DT>SHA-1</DT> -<DD><B>S</B>ecure<B> H</B>ash<B> A</B>lgorithm, a<A href="#digest"> - message digest algorithm</A> developed by the<A href="#NSA"> NSA</A> - for use in the Digital Signature standard,<A href="#FIPS"> FIPS</A> - number 186 from<A href="#NIST"> NIST</A>. SHA is an improved variant of<A -href="#MD4"> MD4</A> producing a 160-bit hash. -<P>SHA is one of two message digest algorithms available in IPsec. The - other is<A href="#MD5"> MD5</A>. Some people do not trust SHA because - it was developed by the<A href="#NSA"> NSA</A>. There is, as far as we - know, no cryptographic evidence that SHA is untrustworthy, but this - does not prevent that view from being strongly held.</P> -<P>The NSA made one small change after the release of the original SHA. - They did not give reasons. Iit may be a defense against some attack - they found and do not wish to disclose. Technically the modified - algorithm should be called SHA-1, but since it has replaced the - original algorithm in nearly all applications, it is generally just - referred to as SHA..</P> -</DD> -<DT><A name="SHA-256">SHA-256</A></DT> -<DT>SHA-384</DT> -<DT>SHA-512</DT> -<DD>Newer variants of SHA designed to match the strength of the 128, 192 - and 256-bit keys of<A href="#AES"> AES</A>. The work to break an - encryption algorithm's strength by<A href="#brute"> brute force</A> is - 2 -<!--math xmlns="http://www.w3.org/1998/Math/MathML"--> - -<!--msup--> - -<!--mi--> - keylength</(null)></(null)></(null)> operations but a<A href="birthday"> - birthday attack</A> on a hash needs only 2 -<!--math xmlns="http://www.w3.org/1998/Math/MathML"--> - -<!--msup--> - -<!--mrow--> - -<!--mi--> - hashlength</(null)> -<!--mo--> - /</(null)> -<!--mn--> - - 2</(null)></(null)></(null)></(null)> , so as a general rule you need a - hash twice the size of the key to get similar strength. SHA-256, - SHA-384 and SHA-512 are designed to match the 128, 192 and 256-bit key - sizes of AES, respectively.</DD> -<DT><A name="SIGINT">Signals intelligence (SIGINT)</A></DT> -<DD>Activities of government agencies from various nations aimed at - protecting their own communications and reading those of others. - Cryptography, cryptanalysis, wiretapping, interception and monitoring - of various sorts of signals. The players include the American<A href="#NSA"> - NSA</A>, British<A href="#GCHQ"> GCHQ</A> and Canadian<A href="#CSE"> - CSE</A>.</DD> -<DT><A name="SKIP">SKIP</A></DT> -<DD><B>S</B>imple<B> K</B>ey management for<B> I</B>nternet<B> P</B> -rotocols, an alternative to<A href="#IKE"> IKE</A> developed by Sun and - being marketed by their<A href="http://skip.incog.com"> Internet - Commerce Group</A>.</DD> -<DT><A name="snake">Snake oil</A></DT> -<DD>Bogus cryptography. See the<A href="http://www.interhack.net/people/cmcurtin/snake-oil-faq.html"> - Snake Oil FAQ</A> or<A href="http://www.counterpane.com/crypto-gram-9902.html#snakeoil"> - this paper</A> by Schneier.</DD> -<DT><A name="SPI">SPI</A></DT> -<DD><B>S</B>ecurity<B> P</B>arameter<B> I</B>ndex, an index used within<A -href="#IPSEC"> IPsec</A> to keep connections distinct. A<A href="#SA"> - Security Association (SA)</A> is defined by destination, protocol and - SPI. Without the SPI, two connections to the same gateway using the - same protocol could not be distinguished. -<P>For more detail, see our<A href="ipsec.html"> IPsec</A> section - and/or RFC 2401.</P> -</DD> -<DT><A name="SSH">SSH</A></DT> -<DD><B>S</B>ecure<B> SH</B>ell, an encrypting replacement for the - insecure Berkeley commands whose names begin with "r" for "remote": - rsh, rlogin, etc. -<P>For more information on SSH, including how to obtain it, see our - cryptography<A href="#tools"> links</A>.</P> -</DD> -<DT><A name="SSHco">SSH Communications Security</A></DT> -<DD>A company founded by the authors of<A href="#SSH"> SSH</A>. Offices - are in<A href="http://www.ssh.fi"> Finland</A> and<A href="http://www.ipsec.com"> - California</A>. They have a toolkit for developers of IPsec - applications.</DD> -<DT><A name="SSL">SSL</A></DT> -<DD><A href="http://home.netscape.com/eng/ssl3">Secure Sockets Layer</A> -, a set of encryption and authentication services for web browsers, - developed by Netscape. Widely used in Internet commerce. Also known as<A -href="#TLS"> TLS</A>.</DD> -<DT>SSLeay</DT> -<DD>A free implementation of<A href="#SSL"> SSL</A> by Eric Young (eay) - and others. Developed in Australia; not subject to US export controls.</DD> -<DT><A name="static">static IP address</A></DT> -<DD>an IP adddress which is pre-set on the machine itself, as opposed to - a<A href="#dynamic"> dynamic address</A> which is assigned by a<A href="#DHCP"> - DHCP</A> server or obtained as part of the process of establishing a<A href="#PPP"> - PPP</A> or<A href="#PPPoE"> PPPoE</A> connection</DD> -<DT><A name="stream">Stream cipher</A></DT> -<DD>A<A href="#symmetric"> symmetric cipher</A> which produces a stream - of output which can be combined (often using XOR or bytewise addition) - with the plaintext to produce ciphertext. Contrasts with<A href="#block"> - block cipher</A>. -<P><A href="#IPSEC">IPsec</A> does not use stream ciphers. Their main - application is link-level encryption, for example of voice, video or - data streams on a wire or a radio signal.</P> -</DD> -<DT><A name="subnet">subnet</A></DT> -<DD>A group of IP addresses which are logically one network, typically - (but not always) assigned to a group of physically connected machines. - The range of addresses in a subnet is described using a subnet mask. - See next entry.</DD> -<DT>subnet mask</DT> -<DD>A method of indicating the addresses included in a subnet. Here are - two equivalent examples: -<UL> -<LI>101.101.101.0/24</LI> -<LI>101.101.101.0 with mask 255.255.255.0</LI> -</UL> -<P>The '24' is shorthand for a mask with the top 24 bits one and the - rest zero. This is exactly the same as 255.255.255.0 which has three - all-ones bytes and one all-zeros byte.</P> -<P>These indicate that, for this range of addresses, the top 24 bits are - to be treated as naming a network (often referred to as "the - 101.101.101.0/24 subnet") while most combinations of the low 8 bits can - be used to designate machines on that network. Two addresses are - reserved; 101.101.101.0 refers to the subnet rather than a specific - machine while 101.101.101.255 is a broadcast address. 1 to 254 are - available for machines.</P> -<P>It is common to find subnets arranged in a hierarchy. For example, a - large company might have a /16 subnet and allocate /24 subnets within - that to departments. An ISP might have a large subnet and allocate /26 - subnets (64 addresses, 62 usable) to business customers and /29 subnets - (8 addresses, 6 usable) to residential clients.</P> -</DD> -<DT><A name="SWAN">S/WAN</A></DT> -<DD>Secure Wide Area Network, a project involving<A href="#RSAco"> RSA - Data Security</A> and a number of other companies. The goal was to - ensure that all their<A href="#IPSEC"> IPsec</A> implementations would - interoperate so that their customers can communicate with each other - securely.</DD> -<DT><A name="symmetric">Symmetric cryptography</A></DT> -<DD>Symmetric cryptography, also referred to as conventional or secret - key cryptography, relies on a<EM> shared secret key</EM>, identical for - sender and receiver. Sender encrypts with that key, receiver decrypts - with it. The idea is that an eavesdropper without the key be unable to - read the messages. There are two main types of symmetric cipher,<A href="#block"> - block ciphers</A> and<A href="#stream"> stream ciphers</A>. -<P>Symmetric cryptography contrasts with<A href="#public"> public key</A> - or asymmetric systems where the two players use different keys.</P> -<P>The great difficulty in symmetric cryptography is, of course, key - management. Sender and receiver<EM> must</EM> have identical keys and - those keys<EM> must</EM> be kept secret from everyone else. Not too - much of a problem if only two people are involved and they can - conveniently meet privately or employ a trusted courier. Quite a - problem, though, in other circumstances.</P> -<P>It gets much worse if there are many people. An application might be - written to use only one key for communication among 100 people, for - example, but there would be serious problems. Do you actually trust all - of them that much? Do they trust each other that much? Should they? - What is at risk if that key is compromised? How are you going to - distribute that key to everyone without risking its secrecy? What do - you do when one of them leaves the company? Will you even know?</P> -<P>On the other hand, if you need unique keys for every possible - connection between a group of 100, then each user must have 99 keys. - You need either 99*100/2 = 4950<EM> secure</EM> key exchanges between - users or a central authority that<EM> securely</EM> distributes 100 key - packets, each with a different set of 99 keys.</P> -<P>Either of these is possible, though tricky, for 100 users. Either - becomes an administrative nightmare for larger numbers. Moreover, keys<EM> - must</EM> be changed regularly, so the problem of key distribution - comes up again and again. If you use the same key for many messages - then an attacker has more text to work with in an attempt to crack that - key. Moreover, one successful crack will give him or her the text of - all those messages.</P> -<P>In short, the<EM> hardest part of conventional cryptography is key - management</EM>. Today the standard solution is to build a<A href="#hybrid"> - hybrid system</A> using<A href="#public"> public key</A> techniques to - manage keys.</P> -</DD> -<DT><A name="T">T</A></DT> -<DT><A name="TIS">TIS</A></DT> -<DD>Trusted Information Systems, a firewall vendor now part of<A href="#NAI"> - NAI</A>. Their Gauntlet product offers IPsec VPN services. TIS - implemented the first version of<A href="#SDNS"> Secure DNS</A> on a<A href="#DARPA"> - DARPA</A> contract.</DD> -<DT><A name="TLS">TLS</A></DT> -<DD><B>T</B>ransport<B> L</B>ayer<B> S</B>ecurity, a newer name for<A href="#SSL"> - SSL</A>.</DD> -<DT><A name="TOS">TOS field</A></DT> -<DD>The<STRONG> T</STRONG>ype<STRONG> O</STRONG>f<STRONG> S</STRONG> -ervice field in an IP header, used to control qualkity of service - routing.</DD> -<DT><A name="traffic">Traffic analysis</A></DT> -<DD>Deducing useful intelligence from patterns of message traffic, - without breaking codes or reading the messages. In one case during - World War II, the British guessed an attack was coming because all - German radio traffic stopped. The "radio silence" order, intended to - preserve security, actually gave the game away. -<P>In an industrial espionage situation, one might deduce something - interesting just by knowing that company A and company B were talking, - especially if one were able to tell which departments were involved, or - if one already knew that A was looking for acquisitions and B was - seeking funds for expansion.</P> -<P>In general, traffic analysis by itself is not very useful. However, - in the context of a larger intelligence effort where quite a bit is - already known, it can be very useful. When you are solving a complex - puzzle, every little bit helps.</P> -<P><A href="#IPSEC">IPsec</A> itself does not defend against traffic - analysis, but carefully thought out systems using IPsec can provide at - least partial protection. In particular, one might want to encrypt more - traffic than was strictly necessary, route things in odd ways, or even - encrypt dummy packets, to confuse the analyst. We discuss this<A href="#traffic.resist"> - here</A>.</P> -</DD> -<DT><A name="transport">Transport mode</A></DT> -<DD>An IPsec application in which the IPsec gateway is the destination - of the protected packets, a machine acts as its own gateway. Contrast - with<A href="#tunnel"> tunnel mode</A>.</DD> -<DT>Triple DES</DT> -<DD>see<A href="#3DES"> 3DES</A></DD> -<DT><A name="TTL">TTL</A></DT> -<DD><STRONG>T</STRONG>ime<STRONG> T</STRONG>o<STRONG> L</STRONG>ive, - used to control<A href="#DNS"> DNS</A> caching. Servers discard cached - records whose TTL expires</DD> -<DT><A name="tunnel">Tunnel mode</A></DT> -<DD>An IPsec application in which an IPsec gateway provides protection - for packets to and from other systems. Contrast with<A href="#transport"> - transport mode</A>.</DD> -<DT><A name="2key">Two-key Triple DES</A></DT> -<DD>A variant of<A href="#3DES"> triple DES or 3DES</A> in which only - two keys are used. As in the three-key version, the order of operations - is<A href="#EDE"> EDE</A> or encrypt-decrypt-encrypt, but in the - two-key variant the first and third keys are the same. -<P>3DES with three keys has 3*56 = 168 bits of key but has only 112-bit - strength against a<A href="#meet"> meet-in-the-middle</A> attack, so it - is possible that the two key version is just as strong. Last I looked, - this was an open question in the research literature.</P> -<P>RFC 2451 defines triple DES for<A href="#IPSEC"> IPsec</A> as the - three-key variant. The two-key variant should not be used and is not - implemented directly in<A href="#FreeSWAN"> Linux FreeS/WAN</A>. It - cannot be used in automatically keyed mode without major fiddles in the - source code. For manually keyed connections, you could make Linux - FreeS/WAN talk to a two-key implementation by setting two keys the same - in /etc/ipsec.conf.</P> -</DD> -<DT><A name="U">U</A></DT> -<DT><A name="V">V</A></DT> -<DT><A name="virtual">Virtual Interface</A></DT> -<DD>A<A href="#Linux"> Linux</A> feature which allows one physical - network interface to have two or more IP addresses. See the<CITE> Linux - Network Administrator's Guide</CITE> in<A href="#kirch"> book form</A> - or<A href="http://metalab.unc.edu/LDP/LDP/nag/node1.html"> on the web</A> - for details.</DD> -<DT>Virtual Private Network</DT> -<DD>see<A href="#VPN"> VPN</A></DD> -<DT><A name="VPN">VPN</A></DT> -<DD><B>V</B>irtual<B> P</B>rivate<B> N</B>etwork, a network which can - safely be used as if it were private, even though some of its - communication uses insecure connections. All traffic on those - connections is encrypted. -<P><A href="#IPSEC">IPsec</A> is not the only technique available for - building VPNs, but it is the only method defined by<A href="#RFC"> RFCs</A> - and supported by many vendors. VPNs are by no means the only thing you - can do with IPsec, but they may be the most important application for - many users.</P> -</DD> -<DT><A name="VPNC">VPNC</A></DT> -<DD><A href="http://www.vpnc.org">Virtual Private Network Consortium</A> -, an association of vendors of VPN products.</DD> -<DT><A name="W">W</A></DT> -<DT><A name="Wassenaar.gloss">Wassenaar Arrangement</A></DT> -<DD>An international agreement restricting export of munitions and other - tools of war. Unfortunately, cryptographic software is also restricted - under the current version of the agreement.<A href="#Wassenaar"> - Discussion</A>.</DD> -<DT><A name="web">Web of Trust</A></DT> -<DD><A href="#PGP">PGP</A>'s method of certifying keys. Any user can - sign a key; you decide which signatures or combinations of signatures - to accept as certification. This contrasts with the hierarchy of<A href="#CA"> - CAs (Certification Authorities)</A> used in many<A href="#PKI"> PKIs - (Public Key Infrastructures)</A>. -<P>See<A href="#GTR"> Global Trust Register</A> for an interesting - addition to the web of trust.</P> -</DD> -<DT><A name="WEP">WEP (Wired Equivalent Privacy)</A></DT> -<DD>The cryptographic part of the<A href="#IEEE"> IEEE</A> standard for - wireless LANs. As the name suggests, this is designed to be only as - secure as a normal wired ethernet. Anyone with a network conection can - tap it. Its advocates would claim this is good design, refusing to - build in complex features beyond the actual requirements. -<P>Critics refer to WEP as "Wire<EM>tap</EM> Equivalent Privacy", and - consider it a horribly flawed design based on bogus "requirements". You - do not control radio waves as you might control your wires, so the - metaphor in the rationale is utterly inapplicable. A security policy - that chooses not to invest resources in protecting against certain - attacks which can only be conducted by people physically plugged into - your LAN may or may not be reasonable. The same policy is completely - unreasonable when someone can "plug in" from a laptop half a block - away..</P> -<P>There has been considerable analysis indicating that WEP is seriously - flawed. A FAQ on attacks against WEP is available. Part of it reads:</P> -<BLOCKQUOTE> ... attacks are practical to mount using only inexpensive - off-the-shelf equipment. We recommend that anyone using an 802.11 - wireless network not rely on WEP for security, and employ other - security measures to protect their wireless network. Note that our - attacks apply to both 40-bit and the so-called 128-bit versions of WEP - equally well.</BLOCKQUOTE> -<P>WEP appears to be yet another instance of governments, and - unfortunately some vendors and standards bodies, deliberately promoting - hopelessly flawed "security" products, apparently mainly for the - benefit of eavesdropping agencies. See this<A href="#weak"> discussion</A> -.</P> -</DD> -<DT><A name="X">X</A></DT> -<DT><A name="X509">X.509</A></DT> -<DD>A standard from the<A href="http://www.itu.int"> ITU (International - Telecommunication Union)</A>, for hierarchical directories with - authentication services, used in many<A href="#PKI"> PKI</A> - implementations. -<P>Use of X.509 services, via the<A href="#LDAP"> LDAP protocol</A>, for - certification of keys is allowed but not required by the<A href="#IPSEC"> - IPsec</A> RFCs. It is not yet implemented in<A href="#FreeSWAN"> Linux - FreeS/WAN</A>.</P> -</DD> -<DT>Xedia</DT> -<DD>A vendor of router and Internet access products, now part of Lucent. - Their QVPN products interoperate with Linux FreeS/WAN; see our<A href="#xedia"> - interop document</A>.</DD> -<DT><A name="Y">Y</A></DT> -<DT><A name="Z">Z</A></DT> -</DL> -<HR> -<H1><A name="biblio">Bibliography for the Linux FreeS/WAN project</A></H1> -<P>For extensive bibliographic links, see the<A href="http://liinwww.ira.uka.de/bibliography/index.html"> - Collection of Computer Science Bibliographies</A></P> -<P>See our<A href="web.html"> web links</A> for material available - online.</P> -<HR><A name="adams"> Carlisle Adams and Steve Lloyd<CITE> Understanding - Public Key Infrastructure</CITE> -<BR></A> Macmillan 1999 ISBN 1-57870-166-x -<P>An overview, mainly concentrating on policy and strategic issues - rather than the technical details. Both authors work for<A href="#PKI"> - PKI</A> vendor<A href="http://www.entrust.com/"> Entrust</A>.</P> -<HR><A name="DNS.book"> Albitz, Liu & Loukides<CITE> DNS & BIND</CITE> - 3rd edition -<BR></A> O'Reilly 1998 ISBN 1-56592-512-2 -<P>The standard reference on the<A href="#DNS"> Domain Name Service</A> - and<A href="#BIND"> Berkeley Internet Name Daemon</A>.</P> -<HR><A name="anderson"> Ross Anderson</A>,<CITE> Security Engineering - - a Guide to Building Dependable Distributed Systems</CITE> -<BR> Wiley, 2001, ISBN 0471389226 -<P>Easily the best book for the security professional I have seen.<STRONG> - Highly recommended</STRONG>. See the<A href="http://www.cl.cam.ac.uk/~rja14/book.html"> - book web page</A>.</P> -<P>This is quite readable, but Schneier's<A href="#secrets"> Secrets and - Lies</A> might be an easier introduction.</P> -<HR><A name="puzzle"> Bamford<CITE> The Puzzle Palace, A report on NSA, - Americas's most Secret Agency</CITE> -<BR> Houghton Mifflin 1982 ISBN 0-395-31286-8</A> -<HR> Bamford<CITE> Body of Secrets</CITE> -<P>The sequel.</P> -<HR><A name="bander"> David Bander</A>,<CITE> Linux Security Toolkit</CITE> -<BR> IDG Books, 2000, ISBN: 0764546902 -<P>This book has a short section on FreeS/WAN and includes Caldera Linux - on CD.</P> -<HR><A name="CZR"> Chapman, Zwicky & Russell</A>,<CITE> Building - Internet Firewalls</CITE> -<BR> O'Reilly 1995 ISBN 1-56592-124-0 -<HR><A name="firewall.book"> Cheswick and Bellovin</A><CITE> Firewalls - and Internet Security: Repelling the Wily Hacker</CITE> -<BR> Addison-Wesley 1994 ISBN 0201633574 -<P>A fine book on firewalls in particular and security in general from - two of AT&T's system adminstrators.</P> -<P>Bellovin has also done a number of<A href="#papers"> papers</A> on - IPsec and co-authored a<A href="#applied"> paper</A> on a large - FreeS/WAN application.</P> -<HR><A name="comer"> Comer<CITE> Internetworking with TCP/IP</CITE> -<BR> Prentice Hall</A> -<UL> -<LI>Vol. I: Principles, Protocols, & Architecture, 3rd Ed. 1995 - ISBN:0-13-216987-8</LI> -<LI>Vol. II: Design, Implementation, & Internals, 2nd Ed. 1994 - ISBN:0-13-125527-4</LI> -<LI>Vol. III: Client/Server Programming & Applications -<UL> -<LI>AT&T TLI Version 1994 ISBN:0-13-474230-3</LI> -<LI>BSD Socket Version 1996 ISBN:0-13-260969-X</LI> -<LI>Windows Sockets Version 1997 ISBN:0-13-848714-6</LI> -</UL> -</LI> -</UL> -<P>If you need to deal with the details of the network protocols, read - either this series or the<A href="#stevens"> Stevens and Wright</A> - series before you start reading the RFCs.</P> -<HR><A name="diffie"> Diffie and Landau</A><CITE> Privacy on the Line: - The Politics of Wiretapping and Encryption</CITE> -<BR> MIT press 1998 ISBN 0-262-04167-7 (hardcover) or 0-262-54100-9 -<BR> -<HR><A name="d_and_hark"> Doraswamy and Harkins<CITE> IP Sec: The New - Security Standard for the Internet, Intranets and Virtual Private - Networks</CITE> -<BR> Prentice Hall 1999 ISBN: 0130118982</A> -<HR><A name="EFF"> Electronic Frontier Foundation<CITE> Cracking DES: - Secrets of Encryption Research, Wiretap Politics and Chip Design</CITE> -<BR></A> O'Reilly 1998 ISBN 1-56592-520-3 -<P>To conclusively demonstrate that DES is inadequate for continued use, - the<A href="#EFF"> EFF</A> built a machine for just over $200,000 that - breaks DES encryption in under five days on average, under nine in the - worst case.</P> -<P>The book provides details of their design and, perhaps even more - important, discusses why they felt the project was necessary. - Recommended for anyone interested in any of the three topics mentioned - in the subtitle.</P> -<P>See also the<A href="http://www.eff.org/descracker.html"> EFF page on - this project</A> and our discussion of<A href="#desnotsecure"> DES - insecurity</A>.</P> -<HR> Martin Freiss<CITE> Protecting Networks with SATAN</CITE> -<BR> O'Reilly 1998 ISBN 1-56592-425-8 -<BR> translated from a 1996 work in German -<P>SATAN is a Security Administrator's Tool for Analysing Networks. This - book is a tutorial in its use.</P> -<HR> Gaidosch and Kunzinger<CITE> A Guide to Virtual Private Networks</CITE> -<BR> Prentice Hall 1999 ISBN: 0130839647 -<HR><A name="Garfinkel"> Simson Garfinkel</A><CITE> Database Nation: the - death of privacy in the 21st century</CITE> -<BR> O'Reilly 2000 ISBN 1-56592-653-6 -<P>A thoughtful and rather scary book.</P> -<HR><A name="PGP"> Simson Garfinkel</A><CITE> PGP: Pretty Good Privacy</CITE> -<BR> O'Reilly 1995 ISBN 1-56592-098-8 -<P>An excellent introduction and user manual for the<A href="#PGP"> PGP</A> - email-encryption package. PGP is a good package with a complex and - poorly-designed user interface. This book or one like it is a must for - anyone who has to use it at length.</P> -<P>The book covers using PGP in Unix, PC and Macintosh environments, - plus considerable background material on both the technical and - political issues around cryptography.</P> -<P>The book is now seriously out of date. It does not cover recent - developments such as commercial versions since PGP 5, the Open PGP - standard or GNU PG..</P> -<HR><A name="practical"> Garfinkel and Spafford</A><CITE> Practical Unix - Security</CITE> -<BR> O'Reilly 1996 ISBN 1-56592-148-8 -<P>A standard reference.</P> -<P>Spafford's web page has an excellent collection of<A href="http://www.cs.purdue.edu/coast/hotlist"> - crypto and security links</A>.</P> -<HR><A name="Kahn"> David Kahn</A><CITE> The Codebreakers: the - Comprehensive History of Secret Communications from Ancient Times to - the Internet</CITE> -<BR> second edition Scribner 1996 ISBN 0684831309 -<P>A history of codes and code-breaking from ancient Egypt to the 20th - century. Well-written and exhaustively researched.<STRONG> Highly - recommended</STRONG>, even though it does not have much on computer - cryptography.</P> -<HR> David Kahn<CITE> Seizing the Enigma, The Race to Break the German - U-Boat codes, 1939-1943</CITE> -<BR> Houghton Mifflin 1991 ISBN 0-395-42739-8 -<HR><A name="kirch"> Olaf Kirch</A><CITE> Linux Network Administrator's - Guide</CITE> -<BR> O'Reilly 1995 ISBN 1-56592-087-2 -<P>Now becoming somewhat dated in places, but still a good introductory - book and general reference.</P> -<HR><A name="LinVPN"> Kolesnikov and Hatch</A>,<CITE> Building Linux - Virtual Private Networks (VPNs)</CITE> -<BR> New Riders 2002 -<P>This has had a number of favorable reviews, including<A href="http://www.slashdot.org/article.pl?sid=02/02/27/0115214&mode=thread&tid=172"> - this one</A> on Slashdot. The book has a<A href="http://www.buildinglinuxvpns.net/"> - web site</A>.</P> -<HR><A name="RFCs"> Pete Loshin<CITE> Big Book of IPsec RFCs</CITE> -<BR> Morgan Kaufmann 2000 ISBN: 0-12-455839-9</A> -<HR><A name="crypto"> Steven Levy<CITE> Crypto: How the Code Rebels Beat - the Government -- Saving Privacy in the Digital Age</CITE></A> -<BR> Penguin 2001, ISBN 0-670--85950-8 -<P><STRONG>Highly recommended</STRONG>. A fine history of recent (about - 1970-2000) developments in the field, and the related political - controversies. FreeS/WAN project founder and leader John Gilmore - appears several times.</P> -<P>The book does not cover IPsec or FreeS/WAN, but this project is very - much another battle in the same war. See our discussion of the<A href="politics.html"> - politics</A>.</P> -<HR><A name="GTR"> Matyas, Anderson et al.</A><CITE> The Global Trust - Register</CITE> -<BR> Northgate Consultants Ltd 1998 ISBN: 0953239705 -<BR> hard cover edition MIT Press 1999 ISBN 0262511053 -<P>From<A href="http://www.cl.cam.ac.uk/Research/Security/Trust-Register"> - their web page:</A></P> -<BLOCKQUOTE> This book is a register of the fingerprints of the world's - most important public keys; it implements a top-level certification - authority (CA) using paper and ink rather than in an electronic system.</BLOCKQUOTE> -<HR><A name="handbook"> Menezies, van Oorschot and Vanstone<CITE> - Handbook of Applied Cryptography</CITE></A> -<BR> CRC Press 1997 -<BR> ISBN 0-8493-8523-7 -<P>An excellent reference. Read<A href="#schneier"> Schneier</A> before - tackling this.</P> -<HR> Michael Padlipsky<CITE> Elements of Networking Style</CITE> -<BR> Prentice-Hall 1985 ISBN 0-13-268111-0 or 0-13-268129-3 -<P>Probably<STRONG> the funniest technical book ever written</STRONG>, - this is a vicious but well-reasoned attack on the OSI "seven layer - model" and all that went with it. Several chapters of it are also - available as RFCs 871 to 875.</P> -<HR><A name="matrix"> John S. Quarterman</A><CITE> The Matrix: Computer - Networks and Conferencing Systems Worldwide</CITE> -<BR> Digital Press 1990 ISBN 155558-033-5 -<BR> Prentice-Hall ISBN 0-13-565607-9 -<P>The best general treatment of computer-mediated communication we have - seen. It naturally has much to say about the Internet, but also covers - UUCP, Fidonet and so on.</P> -<HR><A name="ranch"> David Ranch</A><CITE> Securing Linux Step by Step</CITE> -<BR> SANS Institute, 1999 -<P><A href="http://www.sans.org/">SANS</A> is a respected organisation, - this guide is part of a well-known series, and Ranch has previously - written the useful<A href=" http://www.ecst.csuchico.edu/~dranch/LINUX/index-linux.html#trinityos"> - Trinity OS</A> guide to securing Linux, so my guess would be this is a - pretty good book. I haven't read it yet, so I'm not certain. It can be - ordered online from<A href="http://www.sans.org/"> SANS</A>.</P> -<P>Note (Mar 1, 2002): a new edition with different editors in the - works. Expect it this year.</P> -<HR><A name="schneier"> Bruce Schneier</A><CITE> Applied Cryptography, - Second Edition</CITE> -<BR> John Wiley & Sons, 1996 -<BR> ISBN 0-471-12845-7 hardcover -<BR> ISBN 0-471-11709-9 paperback -<P>A standard reference on computer cryptography. For more recent - essays, see the<A href="http://www.counterpane.com/"> author's - company's web site</A>.</P> -<HR><A name="secrets"> Bruce Schneier</A><CITE> Secrets and Lies</CITE> -<BR> Wiley 2000, ISBN 0-471-25311-1 -<P>An interesting discussion of security and privacy issues, written - with more of an "executive overview" approach rather than a narrow - focus on the technical issues.<STRONG> Highly recommended</STRONG>.</P> -<P>This is worth reading even if you already understand security issues, - or think you do. To go deeper, follow it with Anderson's<A href="#anderson"> - Security Engineering</A>.</P> -<HR><A name="VPNbook"> Scott, Wolfe and Irwin<CITE> Virtual Private - Networks</CITE></A> -<BR> 2nd edition, O'Reilly 1999 ISBN: 1-56592-529-7 -<P>This is the only O'Reilly book, out of a dozen I own, that I'm - disappointed with. It deals mainly with building VPNs with various - proprietary tools --<A href="#PPTP"> PPTP</A>,<A href="#ssh"> SSH</A>, - Cisco PIX, ... -- and touches only lightly on IPsec-based approaches.</P> -<P>That said, it appears to deal competently with what it does cover and - it has readable explanations of many basic VPN and security concepts. - It may be exactly what some readers require, even if I find the - emphasis unfortunate.</P> -<HR><A name="LASG"> Kurt Seifried<CITE> Linux Administrator's Security - Guide</CITE></A> -<P>Available online from<A href="http://www.securityportal.com/lasg/"> - Security Portal</A>. It has fairly extensive coverage of IPsec.</P> -<HR><A name="Smith"> Richard E Smith<CITE> Internet Cryptography</CITE> -<BR></A> ISBN 0-201-92480-3, Addison Wesley, 1997 -<P>See the book's<A href="http://www.visi.com/crypto/inet-crypto/index.html"> - home page</A></P> -<HR><A name="neal"> Neal Stephenson<CITE> Cryptonomicon</CITE></A> -<BR> Hardcover ISBN -380-97346-4, Avon, 1999. -<P>A novel in which cryptography and the net figure prominently.<STRONG> - Highly recommended</STRONG>: I liked it enough I immediately went out - and bought all the author's other books.</P> -<P>There is also a paperback edition. Sequels are expected.</P> -<HR><A name="stevens"> Stevens and Wright</A><CITE> TCP/IP Illustrated</CITE> -<BR> Addison-Wesley -<UL> -<LI>Vol. I: The Protocols 1994 ISBN:0-201-63346-9</LI> -<LI>Vol. II: The Implementation 1995 ISBN:0-201-63354-X</LI> -<LI>Vol. III: TCP for Transactions, HTTP, NNTP, and the UNIX Domain - Protocols 1996 ISBN: 0-201-63495-3</LI> -</UL> -<P>If you need to deal with the details of the network protocols, read - either this series or the<A href="#comer"> Comer</A> series before you - start reading the RFCs.</P> -<HR><A name="Rubini"> Rubini</A><CITE> Linux Device Drivers</CITE> -<BR> O'Reilly & Associates, Inc. 1998 ISBN 1-56592-292-1 -<HR><A name="Zeigler"> Robert Zeigler</A><CITE> Linux Firewalls</CITE> -<BR> Newriders Publishing, 2000 ISBN 0-7537-0900-9 -<P>A good book, with detailed coverage of ipchains(8) firewalls and of - many related issues.</P> -<HR> -<H1><A name="RFC">IPsec RFCs and related documents</A></H1> -<H2><A name="RFCfile">The RFCs.tar.gz Distribution File</A></H2> -<P>The Linux FreeS/WAN distribution is available from<A href="http://www.xs4all.nl/~freeswan"> - our primary distribution site</A> and various mirror sites. To give - people more control over their downloads, the RFCs that define IP - security are bundled separately in the file RFCs.tar.gz.</P> -<P>The file you are reading is included in the main distribution and is - available on the web site. It describes the RFCs included in the<A href="#RFCs.tar.gz"> - RFCs.tar.gz</A> bundle and gives some pointers to<A href="#sources"> - other ways to get them</A>.</P> -<H2><A name="sources">Other sources for RFCs & Internet drafts</A></H2> -<H3><A name="RFCdown">RFCs</A></H3> -<P>RFCs are downloadble at many places around the net such as:</P> -<UL> -<LI><A href="http://www.rfc-editor.org">http://www.rfc-editor.org</A></LI> -<LI><A href="http://nis.nsf.net/internet/documents/rfc">NSF.net</A></LI> -<LI><A href="http://sunsite.doc.ic.ac.uk/computing/internet/rfc">Sunsite - in the UK</A></LI> -</UL> -<P>browsable in HTML form at others such as:</P> -<UL> -<LI><A href="http://www.landfield.com/rfcs/index.html">landfield.com</A></LI> -<LI><A href="http://www.library.ucg.ie/Connected/RFC">Connected Internet - Encyclopedia</A></LI> -</UL> -<P>and some of them are available in translation:</P> -<UL> -<LI><A href="http://www.eisti.fr/eistiweb/docs/normes/">French</A></LI> -</UL> -<P>There is also a published<A href="#RFCs"> Big Book of IPSEC RFCs</A>.</P> -<H3><A name="drafts">Internet Drafts</A></H3> -<P>Internet Drafts, working documents which sometimes evolve into RFCs, - are also available.</P> -<UL> -<LI><A href="http://www.ietf.org/ID.html">Overall reference page</A></LI> -<LI><A href="http://www.ietf.org/ids.by.wg/ipsec.html">IPsec</A> working - group</LI> -<LI><A href="http://www.ietf.org/ids.by.wg/ipsra.html">IPSRA (IPsec - Remote Access)</A> working group</LI> -<LI><A href="http://www.ietf.org/ids.by.wg/ipsp.html">IPsec Policy</A> - working group</LI> -<LI><A href="http://www.ietf.org/ids.by.wg/kink.html">KINK (Kerberized - Internet Negotiation of Keys)</A> working group</LI> -</UL> -<P>Note: some of these may be obsolete, replaced by later drafts or by - RFCs.</P> -<H3><A name="FIPS1">FIPS standards</A></H3> -<P>Some things used by<A href="#IPSEC"> IPsec</A>, such as<A href="#DES"> - DES</A> and<A href="#SHA"> SHA</A>, are defined by US government - standards called<A href="#FIPS"> FIPS</A>. The issuing organisation,<A href="#NIST"> - NIST</A>, have a<A href="http://www.itl.nist.gov/div897/pubs"> FIPS - home page</A>.</P> -<H2><A name="RFCs.tar.gz">What's in the RFCs.tar.gz bundle?</A></H2> -<P>All filenames are of the form rfc*.txt, with the * replaced with the - RFC number.</P> -<PRE>RFC# Title</PRE> -<H3><A name="rfc.ov">Overview RFCs</A></H3> -<PRE>2401 Security Architecture for the Internet Protocol -2411 IP Security Document Roadmap</PRE> -<H3><A name="basic.prot">Basic protocols</A></H3> -<PRE>2402 IP Authentication Header -2406 IP Encapsulating Security Payload (ESP)</PRE> -<H3><A name="key.ike">Key management</A></H3> -<PRE>2367 PF_KEY Key Management API, Version 2 -2407 The Internet IP Security Domain of Interpretation for ISAKMP -2408 Internet Security Association and Key Management Protocol (ISAKMP) -2409 The Internet Key Exchange (IKE) -2412 The OAKLEY Key Determination Protocol -2528 Internet X.509 Public Key Infrastructure</PRE> -<H3><A name="rfc.detail">Details of various things used</A></H3> -<PRE>2085 HMAC-MD5 IP Authentication with Replay Prevention -2104 HMAC: Keyed-Hashing for Message Authentication -2202 Test Cases for HMAC-MD5 and HMAC-SHA-1 -2207 RSVP Extensions for IPSEC Data Flows -2403 The Use of HMAC-MD5-96 within ESP and AH -2404 The Use of HMAC-SHA-1-96 within ESP and AH -2405 The ESP DES-CBC Cipher Algorithm With Explicit IV -2410 The NULL Encryption Algorithm and Its Use With IPsec -2451 The ESP CBC-Mode Cipher Algorithms -2521 ICMP Security Failures Messages</PRE> -<H3><A name="rfc.ref">Older RFCs which may be referenced</A></H3> -<PRE>1321 The MD5 Message-Digest Algorithm -1828 IP Authentication using Keyed MD5 -1829 The ESP DES-CBC Transform -1851 The ESP Triple DES Transform -1852 IP Authentication using Keyed SHA</PRE> -<H3><A name="rfc.dns">RFCs for secure DNS service, which IPsec may use</A> -</H3> -<PRE>2137 Secure Domain Name System Dynamic Update -2230 Key Exchange Delegation Record for the DNS -2535 Domain Name System Security Extensions -2536 DSA KEYs and SIGs in the Domain Name System (DNS) -2537 RSA/MD5 KEYs and SIGs in the Domain Name System (DNS) -2538 Storing Certificates in the Domain Name System (DNS) -2539 Storage of Diffie-Hellman Keys in the Domain Name System (DNS)</PRE> -<H3><A name="rfc.exp">RFCs labelled "experimental"</A></H3> -<PRE>2521 ICMP Security Failures Messages -2522 Photuris: Session-Key Management Protocol -2523 Photuris: Extended Schemes and Attributes</PRE> -<H3><A name="rfc.rel">Related RFCs</A></H3> -<PRE>1750 Randomness Recommendations for Security -1918 Address Allocation for Private Internets -1984 IAB and IESG Statement on Cryptographic Technology and the Internet -2144 The CAST-128 Encryption Algorithm</PRE> -<HR> -<H1><A name="roadmap">Distribution Roadmap: What's Where in Linux - FreeS/WAN</A></H1> -<P> This file is a guide to the locations of files within the FreeS/WAN - distribution. Everything described here should be on your system once - you download, gunzip, and untar the distribution.</P> -<P>This distribution contains two major subsystems</P> -<DL> -<DT><A href="#klips.roadmap">KLIPS</A></DT> -<DD>the kernel code</DD> -<DT><A href="#pluto.roadmap">Pluto</A></DT> -<DD>the user-level key-management daemon</DD> -</DL> -<P>plus assorted odds and ends.</P> -<H2><A name="top">Top directory</A></H2> -<P>The top directory has essential information in text files:</P> -<DL> -<DT>README</DT> -<DD>introduction to the software</DD> -<DT>INSTALL</DT> -<DD>short experts-only installation procedures. More detalied procedures - are in<A href="install.html"> installation</A> and<A href="config.html"> - configuration</A> HTML documents.</DD> -<DT>BUGS</DT> -<DD>major known bugs in the current release.</DD> -<DT>CHANGES</DT> -<DD>changes from previous releases</DD> -<DT>CREDITS</DT> -<DD>acknowledgement of contributors</DD> -<DT>COPYING</DT> -<DD>licensing and distribution information</DD> -</DL> -<H2><A name="doc">Documentation</A></H2> -<P> The doc directory contains the bulk of the documentation, most of it - in HTML format. See the<A href="index.html"> index file</A> for - details.</P> -<H2><A name="klips.roadmap">KLIPS: kernel IP security</A></H2> -<P><A href="#KLIPS"> KLIPS</A> is<STRONG> K</STRONG>erne<STRONG>L</STRONG><STRONG> - IP</STRONG><STRONG> S</STRONG>ecurity. It lives in the klips directory, - of course.</P> -<DL> -<DT>klips/doc</DT> -<DD>documentation</DD> -<DT>klips/patches</DT> -<DD>patches for existing kernel files</DD> -<DT>klips/test</DT> -<DD>test stuff</DD> -<DT>klips/utils</DT> -<DD>low-level user utilities</DD> -<DT>klips/net/ipsec</DT> -<DD>actual klips kernel files</DD> -<DT>klips/src</DT> -<DD>symbolic link to klips/net/ipsec -<P>The "make insert" step of installation installs the patches and makes - a symbolic link from the kernel tree to klips/net/ipsec. The odd name - of klips/net/ipsec is dictated by some annoying limitations of the - scripts which build the Linux kernel. The symbolic-link business is a - bit messy, but all the alternatives are worse.</P> -<P></P> -</DD> -<DT>klips/utils</DT> -<DD>Utility programs: -<P></P> -<DL> -<DT>eroute</DT> -<DD>manipulate IPsec extended routing tables</DD> -<DT>klipsdebug</DT> -<DD>set Klips (kernel IPsec support) debug features and level</DD> -<DT>spi</DT> -<DD>manage IPsec Security Associations</DD> -<DT>spigrp</DT> -<DD>group/ungroup IPsec Security Associations</DD> -<DT>tncfg</DT> -<DD>associate IPsec virtual interface with real interface</DD> -</DL> -<P>These are all normally invoked by ipsec(8) with commands such as</P> -<PRE> ipsec tncfg <VAR>arguments</VAR></PRE> - There are section 8 man pages for all of these; the names have "ipsec_" - as a prefix, so your man command should be something like: -<PRE> man 8 ipsec_tncfg</PRE> -</DD> -</DL> -<H2><A name="pluto.roadmap">Pluto key and connection management daemon</A> -</H2> -<P><A href="#Pluto"> Pluto</A> is our key management and negotiation - daemon. It lives in the pluto directory, along with its low-level user - utility, whack.</P> -<P> There are no subdirectories. Documentation is a man page,<A href="manpage.d/ipsec_pluto.8.html"> - pluto.8</A>. This covers whack as well.</P> -<H2><A name="utils">Utils</A></H2> -<P> The utils directory contains a growing collection of higher-level - user utilities, the commands that administer and control the software. - Most of the things that you will actually have to run yourself are in - there.</P> -<DL> -<DT>ipsec</DT> -<DD>invoke IPsec utilities -<P>ipsec(8) is normally the only program installed in a standard - directory, /usr/local/sbin. It is used to invoke the others, both those - listed below and the ones in klips/utils mentioned above.</P> -<P></P> -</DD> -<DT>auto</DT> -<DD>control automatically-keyed IPsec connections</DD> -<DT>manual</DT> -<DD>take manually-keyed IPsec connections up and down</DD> -<DT>barf</DT> -<DD>generate copious debugging output</DD> -<DT>look</DT> -<DD>generate moderate amounts of debugging output</DD> -</DL> -<P> There are .8 manual pages for these. look is covered in barf.8. The - man pages have an "ipsec_" prefix so your man command should be - something like:</P> -<PRE> - man 8 ipsec_auto -</PRE> -<P> Examples are in various files with names utils/*.eg</P> -<H2><A name="lib">Libraries</A></H2> -<H3><A name="fswanlib">FreeS/WAN Library</A></H3> -<P> The lib directory is the FreeS/WAN library, also steadily growing, - used by both user-level and kernel code. -<BR /> It includes section 3<A href="manpages.html"> man pages</A> for - the library routines.</P> -<H3><A name="otherlib">Imported Libraries</A></H3> -<H4><A NAME="33_6_2_1">LibDES</A></H4> - The libdes library, originally from SSLeay, is used by both Klips and - Pluto for<A href="#3DES"> Triple DES</A> encryption. Single DES is not - used because<A href="#desnotsecure"> it is insecure</A>. -<P> Note that this library has its own license, different from the<A href="#GPL"> - GPL</A> used for other code in FreeS/WAN.</P> -<P> The library includes its own documentation.</P> -<H4><A NAME="33_6_2_2">GMP</A></H4> - The GMP (GNU multi-precision) library is used for multi-precision - arithmetic in Pluto's key-exchange code and public key code. -<P> Older versions (up to 1.7) of FreeS/WAN included a copy of this - library in the FreeS/WAN distribution.</P> -<P> Since 1.8, we have begun to rely on the system copy of GMP.</P> -<HR> -<H1><A name="umltesting">User-Mode-Linux Testing guide</A></H1> -<P> User mode linux is a way to compile a linux kernel such that it can - run as a process in another linux system (potentially as a *BSD or - Windows process later). See<A HREF="http://user-mode-linux.sourceforge.net/"> - http://user-mode-linux.sourceforge.net/</A></P> -<P> UML is a good platform for testing and experimenting with FreeS/WAN. - It allows several network nodes to be simulated on a single machine. - Creating, configuring, installing, monitoring, and controling these - nodes is generally easier and easier to script with UML than real - hardware.</P> -<P> You'll need about 500Mb of disk space for a full - sunrise-east-west-sunset setup. You can possibly get this down by 130Mb - if you remove the sunrise/sunset kernel build. If you just want to run, - then you can even remove the east/west kernel build.</P> -<P> Nothing need be done as super user. In a couple of steps, we note - where super user is required to install commands in system-wide - directories, but ~/bin could be used instead. UML seems to use a - system-wide /tmp/uml directory so different users may interfere with - one another. Later UMLs use ~/.uml instead, so multiple users running - UML tests should not be a problem, but note that a single user running - the UML tests will only be able run one set. Further, UMLs sometimes - get stuck and hang around. These "zombies" (most will actually be in - the "T" state in the process table) will interfere with subsequent - tests.</P> -<H2><A NAME="34_1">Preliminary Notes on BIND</A></H2> -<P> As of 2003/3/1, the Light-Weight Resolver is used by pluto. This - requires that BIND9 be running. It also requires that BIND9 development - libraries be present in the build environment. The DNSSEC code is only - truly functional in BIND9 snapshots. The library code could be 9.2.2, - we believe. We are using BIND9 20021115 snapshot code from<A HREF="ftp://ftp.isc.org/isc/bind9/snapshots"> - ftp://ftp.isc.org/isc/bind9/snapshots</A>.</P> -<P> FreeS/WAN may well require a newer BIND than is on your system. Many - distributions have moved to BIND9.2.2 recently due to a security - advisory. BIND is five components.</P> -<OL> -<LI> named</LI> -<LI> dnssec-*</LI> -<LI> client side resolver libraries</LI> -<LI> client side utility libraries I thought there were lib and named - parts to dnsssec...</LI> -<LI> dynamic DNS update utilities</LI> -</OL> -<P> The only piece that we need for *building* is #4. That's the only - part that has to be on the build host. What is the difference between - resolver and util libs? If you want to edit - testing/baseconfigs/all/etc/bind, you'll need a snapshot version. The - resolver library contains the resolver. FreeS/WAN has its own copy of - that in lib/liblwres.</P> -<H2><A NAME="34_2">Steps to Install UML for FreeS/WAN</A></H2> -<OL> -<LI> Get the following files: -<OL type="a"> -<LI> from<A HREF="http://www.sandelman.ottawa.on.ca/freeswan/uml/"> - http://www.sandelman.ottawa.on.ca/freeswan/uml/</A> - umlfreeroot-15.1.tar.gz (or highest numbered one). This is a debian - potato root file system. You can use this even on a Redhat host, as it - has the newer GLIBC2.2 libraries as well. -<!-- If you are using - Redhat 7.2 or newer as your development machine, you can create the - image from your installation media. See <A HREF="uml-rhroot.html">Building a RedHat root"></A>. - A future document will explain how to build this from .DEB files as well. ---> - -<!-- -<LI> umlfreesharemini.tar.gz (or umlfreeshareall.tar.gz). - If you are a Debian potato user, you don't need it you can use your - native /usr/share. -</UL> ---> -</LI> -<LI> From<A HREF="ftp://ftp.xs4all.nl/pub/crypto/freeswan/"> - ftp://ftp.xs4all.nl/pub/crypto/freeswan/</A> a snapshot or release - (1.92 or better)</LI> -<LI> From a<A HREF="http://www.kernel.org/mirrors/"> - http://www.kernel.org mirror</A>, the virgin 2.4.19 kernel. Please - realize that we have defaults in our tree for kernel configuration. We - try to track the latest UML kernels. If you use a newer kernel, you may - have faults in the kernel build process. You can see what the latest - that is being regularly tested by visiting<A HREF="http://bugs.freeswan.org:81/regress/HEAD/lastgood/freeswan-regress-env.sh"> - freeswan-regress-env.sh</A>.</LI> -<LI> -<!-- Note: this step is refered to as "step 1d" below. --> - Get<A HREF="http://ftp.nl.linux.org/uml/"> - http://ftp.nl.linux.org/uml/</A> uml-patch-2.4.19-47.bz2 or the one - associated with your kernel. As of 2003/03/05, uml-patch-2.4.19-47.bz2 - works for us.<STRONG> More recent versions of the patch have not been - tested by us.</STRONG></LI> -<LI> You'll probably want to visit<A HREF="http://user-mode-linux.sourceforge.net"> - http://user-mode-linux.sourceforge.net</A> and get the UML utilities. - These are not needed for the build or interactive use (but - recommended). They are necessary for the regression testing procedures - used by "make check". We currently use uml_utilities_20020212.tar.bz2.</LI> -<LI> You need tcpdump version 3.7.1 or better. This is newer than the - version included in most LINUX distributions. You can check the version - of an installed tcpdump with the --version flag. If you need a newer - tcpdump fetch both tcpdump and libpcap source tar files from<A HREF="http://www.tcpdump.org/"> - http://www.tcpdump.org/</A> or a mirror.</LI> -</OL> -</LI> -<LI> Pick a suitable place, and extract the following files: -<OL type="a"> -<LI> -<!-- Note: this step is refered to as "step 2a" later. --> - 2.4.19 kernel. For instance: -<PRE> - <CODE> cd /c2/kernel - tar xzvf ../download/pub/linux/kernel/v2.4/linux-2.4.19.tar.gz -</CODE> -</PRE> -</LI> -<LI> extract the umlfreeroot file -<!-- (unless you <A HREF="uml-rhroot.html">built your own from RPMs</A>) --> - -<PRE> - <CODE> mkdir -p /c2/user-mode-linux/basic-root - cd /c2/user-mode-linux/basic-root - tar xzvf ../download/umlfreeroot-15.1.tar.gz -</CODE> -</PRE> -</LI> -<LI> FreeSWAN itself (or checkout "all" from CVS) -<PRE> - <CODE> mkdir -p /c2/freeswan/sandbox - cd /c2/freeswan/sandbox - tar xzvf ../download/snapshot.tar.gz -</CODE> -</PRE> -</LI> -</OL> -</LI> -<LI> If you need to build a newer tcpdump: -<UL> -<LI> Make sure you have OpenSSL installed -- it is needed for - cryptographic routines.</LI> -<LI> Unpack libpcap and tcpdump source in parallel directories (the - tcpdump build procedures look for libpcap next door).</LI> -<LI> Change directory into the libpcap source directory and then build - the library: -<PRE> - <CODE> ./configure - make -</CODE> -</PRE> -</LI> -<LI> Change into the tcpdump source directory, build tcpdump, and - install it. -<PRE> - <CODE> ./configure - make - # Need to be superuser to install in system directories. - # Installing in ~/bin would be an alternative. - su -c "make install" -</CODE> -</PRE> -</LI> -</UL> -</LI> -<LI> If you need the uml utilities, unpack them somewhere then build and - install them: -<PRE> - <CODE> cd tools - make all - # Need to be superuser to install in system directories. - # Installing in ~/bin would be an alternative. - su -c "make install BIN_DIR=/usr/local/bin" -</CODE> -</PRE> -</LI> -<LI> set up the configuration file -<UL> -<LI> <CODE>cd /c2/freeswan/sandbox/freeswan-1.97/testing/utils</CODE></LI> -<LI> copy umlsetup-sample.sh to ../../umlsetup.sh: <CODE> cp - umlsetup-sample.sh ../../umlsetup.sh</CODE></LI> -<LI> open up ../../umlsetup.sh in your favorite editor.</LI> -<LI> change POOLSPACE= to point to the place with at least 500Mb of - disk. Best if it is on the same partition as the "umlfreeroot" - extraction, as it will attempt to use hard links if possible to save - disk space.</LI> -<LI> Set TESTINGROOT if you intend to run the script outside of the - sandbox/snapshot/release directory. Otherwise, it will configure - itself.</LI> -<LI> KERNPOOL should point to the directory with your 2.4.19 kernel - tree. This tree should be unconfigured! This is the directory you used - in step 2a.</LI> -<LI> UMLPATCH should point at the bz2 file you downloaded at 1d. If - using a kernel that already includes the patch, set this to /dev/null.</LI> -<LI> FREESWANDIR should point at the directory where you unpacked the - snapshot/release. Include the "freeswan-snap2001sep16b" or whatever in - it. If you are running from CVS, then you point at the directory where - top, klips, etc. are. The script will fix up the directory so that it - can be used.</LI> -<LI> BASICROOT should be set to the directory used in 2b, or to the - directory that you created with RPMs.</LI> -<LI> SHAREDIR should be set to the directory used in 2c, to /usr/share - for Debian potato users, or to $BASICROOT/usr/share.</LI> -</UL> -</LI> -<LI> -<PRE> <CODE>cd $TESTINGROOT/utils -sh make-uml.sh -</CODE></PRE> - It will grind for awhile. If there are errors it will bail. If so, run - it under "script" and send the output to bugs@lists.freeswan.org.</LI> -<LI> You will have a bunch of stuff under $POOLSPACE. Open four xterms: -<PRE> <CODE> for i in sunrise sunset east west - do - xterm -name $i -title $i -e $POOLSPACE/$i/start.sh done -</CODE></PRE> -</LI> -<LI> Login as root. Password is "root" (Note, these virtual machines are - networked together, but are not configured to talk to the rest of the - world.)</LI> -<LI> verify that pluto started on east/west, run "ipsec look"</LI> -<LI> login to sunrise. run "ping sunset"</LI> -<LI> login to west. run "tcpdump -p -i eth1 -n" (tcpdump must be version - 3.7.1 or newer)</LI> -<LI> Closing a console xterm will shut down that UML.</LI> -<LI> You can "make check", if you want to. It is run from - /c2/freeswan/sandbox/freeswan-1.97.</LI> -</OL> -<H1><A NAME="35">Debugging the kernel with GDB</A></H1> -<P> With User-Mode-Linux, you can debug the kernel using GDB. See -<!--HREF="http://user-mode-linux.sourceforge.net/debugging.html"--> - - http://user-mode-linux.sourceforge.net/debugging.html.</(null)></P> -<P> Typically, one will want to address a test case for a failing - situation. Running GDB from Emacs, or from other front ends is - possible. First start GDB.</P> -<P> Tell it to open the UMLPOOL/swan/linux program.</P> -<P> Note the PID of GDB:</P> -<PRE> -marajade-[projects/freeswan/mgmt/planning] mcr 1029 %ps ax | grep gdb - 1659 pts/9 SN 0:00 /usr/bin/gdb -fullname -cd /mara4/freeswan/kernpatch/UMLPOOL/swan/ linux -</PRE> -<P> Set the following in the environment:</P> -<PRE> -UML_east_OPT="debug gdb-pid=1659" -</PRE> -<P> Then start the user-mode-linux in the test scheme you wish:</P> -<PRE> -marajade-[kernpatch/testing/klips/east-icmp-02] mcr 1220 %../../utils/runme.sh -</PRE> - The user-mode-linux will stop on boot, giving you a chance to attach to - the process: -<PRE> -(gdb) file linux -Reading symbols from linux...done. -(gdb) attach 1 -Attaching to program: /mara4/freeswan/kernpatch/UMLPOOL/swan/linux, process 1 -0xa0118bc1 in kill () at hostfs_kern.c:770 -</PRE> -<P> At this point, break points should be created as appropriate.</P> -<H2><A NAME="35_1">Other notes about debugging</A></H2> -<P> If you are running a standard test, after all the packets are sent, - the UML will be shutdown. This can cause problems, because the UML may - get terminated while you are debugging.</P> -<P> The environment variable <CODE>NETJIGWAITUSER</CODE> can be set to - "waituser". If so, then the testing system will prompt before exiting - the test.</P> -<H1><A NAME="36">User-Mode-Linux mysteries</A></H1> -<UL> -<LI> running more than one UML of the same name (e.g. "west") can cause - problems.</LI> -<LI> running more than one UML from the same root file system is not a - good idea.</LI> -<LI> all this means that running "make check" twice on the same machine - is probably not a good idea.</LI> -<LI> occationally, UMLs will get stuck. This can happen like: -<!--BLOCK--> - 15134 ? T - 0:00 /spare/hugh/uml/uml2.4.18-sept5/umlbuild/east/linux (east) - [/bin/sh] 15138 ? T 0:00 - /spare/hugh/uml/uml2.4.18-sept5/umlbuild/east/linux (east) [halt]</(null)> - these will need to be killed. Note that they are in "T"racing mode.</LI> -<LI> UMLs can also hang, and will report "Tracing myself and I can't get - out". This is a bug in UML. There are ways to find out what is going on - and report this to the UML people, but we don't know the magic right - now.</LI> -</UL> -<H1><A NAME="37">Getting more info from uml_netjig</A></H1> -<P> uml_netjig can be compiled with a built-in tcpdump. This uses - not-yet-released code from<A HREF="http://www.tcpdump.org/"> - www.tcpdump.org</A>. Please see the instructions in <CODE> -testing/utils/uml_netjig/Makefile</CODE>.</P> -<HR> -<H1><A name="makecheck">How to configure to use "make check"</A></H1> -<H2><A NAME="38_1">What is "make check"</A></H2> -<P> "make check" is a target in the top level makefile. It takes care of - running a number of unit and system tests to confirm that FreeSWAN has - been compiled correctly, and that no new bugs have been introduced.</P> -<P> As FreeSWAN contains both kernel and userspace components, doing - testing of FreeSWAN requires that the kernel be simulated. This is - typically difficult to do as a kernel requires that it be run on bare - hardware. A technology has emerged that makes this simpler. This is<A HREF="http://user-mode-linux.sourceforge.net"> - User Mode Linux</A>.</P> -<P> User-Mode Linux is a way to build a Linux kernel such that it can - run as a process under another Linux (or in the future other) kernel. - Presently, this can only be done for 2.4 guest kernels. The host kernel - can be 2.2 or 2.4.</P> -<P> "make check" expects to be able to build User-Mode Linux kernels - with FreeSWAN included. To do this it needs to have some files - downloaded and extracted prior to running "make check". This is - described in the<A HREF="umltesting.html"> UML testing</A> document.</P> -<P> After having run the example in the UML testing document and - successfully brought up the four machine combination, you are ready to - use "make check"</P> -<H2><A NAME="38_2">Running "make check"</A></H2> -<P> "make check" works by walking the FreeSWAN source tree invoking the - "check" target at each node. At present there are tests defined only - for the <CODE>klips</CODE> directory. These tests will use the UML - infrastructure to test out pieces of the <CODE>klips</CODE> code.</P> -<P> The results of the tests can be recorded. If the environment - variable <CODE>$REGRESSRESULTS</CODE> is non-null, then the results of - each test will be recorded. This can be used as part of a nightly - regression testing system, see<A HREF="nightly.html"> Nightly testing</A> - for more details.</P> -<P> "make check" otherwise prints a minimal amount of output for each - test, and indicates pass/fail status of each test as they are run. - Failed tests do not cause failure of the target in the form of exit - codes.</P> -<H1><A NAME="39">How to write a "make check" test</A></H1> -<H2><A NAME="39_1">Structure of a test</A></H2> -<P> Each test consists of a set of directories under <CODE>testing/</CODE> -. There are directories for <CODE>klips</CODE>, <CODE>pluto</CODE>, <CODE> -packaging</CODE> and <CODE>libraries</CODE>. Each directory has a list - of tests to run is stored in a file called <CODE>TESTLIST</CODE> in - that directory. e.g. <CODE>testing/klips/TESTLIST</CODE>.</P> -<H2 NAME="TESTLIST"><A NAME="39_2">The TESTLIST</A></H2> -<P> This isn't actually a shell script. It just looks like one. Some - tools other than /bin/sh process it. Lines that start with # are - comments.</P> -<PRE> -# test-kind directory-containing-test expectation [PR#] -</PRE> -<P>The first word provides the test type, detailed below.</P> -<P> The second word is the name of the test to run. This the directory - in which the test case is to be found..</P> -<P>The third word may be one of:</P> -<DL> -<DT> blank/good</DT> -<DD>the test is believed to function, report failure</DD> -<DT> bad</DT> -<DD> the test is known to fail, report unexpected success</DD> -<DT> suspended</DT> -<DD> the test should not be run</DD> -</DL> -<P> The fourth word may be a number, which is a PR# if the test is - failing.</P> -<H2><A NAME="39_3">Test kinds</A></H2> - The test types are: -<DL> -<DT>skiptest</DT> -<DD>means run no test.</DD> -<DT>ctltest</DT> -<DD>means run a single system without input/output.</DD> -<DT>klipstest</DT> -<DD>means run a single system with input/output networks</DD> -<DT><A HREF="#umlplutotest">umlplutotest</A></DT> -<DD>means run a pair of systems</DD> -<DT><A HREF="#umlXhost">umlXhost</A></DT> -<DD>run an arbitrary number of systems</DD> -<DT>suntest (TBD)</DT> -<DD>means run a quad of east/west/sunrise/sunset</DD> -<DT>roadtest (TBD)</DT> -<DD>means run a trio of east-sunrise + warrior</DD> -<DT>extrudedtest (TBD)</DT> -<DD>means run a quad of east-sunrise + warriorsouth + park</DD> -<DT>mkinsttest</DT> -<DD>a test of the "make install" machinery.</DD> -<DT>kernel_test_patch</DT> -<DD>a test of the "make kernelpatch" machinery.</DD> -</DL> - Tests marked (TBD) have yet to be fully defined. -<P> Each test directory has a file in it called <CODE>testparams.sh</CODE> -. This file sets a number of environment variables to define the - parameters of the test.</P> -<H2><A NAME="39_4">Common parameters</A></H2> -<DL> -<DT>TESTNAME</DT> -<DD>the name of the test (repeated for checking purposes)</DD> -<DT>TEST_TYPE</DT> -<DD>the type of the test (repeat of type type above)</DD> -<DT>TESTHOST</DT> -<DD>the name of the UML machine to run for the test, typically "east" or - "west"</DD> -<DT>TEST_PURPOSE</DT> -<DD>The purpose of the test is one of: -<DL> -<DT>goal</DT> -<DD>The goal purpose is where a test is defined for code that is not yet - finished. The test indicates when the goals have in fact been reached.</DD> -<DT>regress</DT> -<DD>This is a test to determine that a previously existing bug has been - repaired. This test will initially be created to reproduce the bug in - isolation, and then the bug will be fixed.</DD> -<DT>exploit</DT> -<DD>This is a set of packets/programs that causes a vulnerability to be - exposed. It is a specific variation of the regress option.</DD> -</DL> -</DD> -<DT>TEST_GOAL_ITEM</DT> -<DT></DT> -<DD>in the case of a goal test, this is a reference to the requirements - document</DD> -<DT>TEST_PROB_REPORT</DT> -<DD>in the case of regression test, this the problem report number from - GNATS</DD> -<DT>TEST_EXPLOIT_URL</DT> -<DD>in the case of an exploit, this is a URL referencing the paper - explaining the origin of the test and the origin of exploit software</DD> -<DT>REF_CONSOLE_OUTPUT</DT> -<DD>a file in the test directory that contains the sanitized console - output against which to compare the output of the actual test.</DD> -<DT>REF_CONSOLE_FIXUPS</DT> -<DD>a list of scripts (found in <CODE>klips/test/fixups</CODE>) to apply - to sanitize the console output of the machine under test. These are - typically perl, awk or sed scripts that remove things in the kernel - output that change each time the test is run and/or compiled.</DD> -<DT>INIT_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode prior to starting the tests. This file will usually - set up any eroute's and SADB entries that are required for the test.</P> -<P>Lines beginning with # are skipped. Blank lines are skipped. - Otherwise, a shell prompted is waited for each time (consisting of <CODE> -\n#</CODE>) and then the command is sent. Note that the prompt is waited - for before the command and not after, so completion of the last command - in the script is not required. This is often used to invoke a program - to monitor the system, e.g. <CODE>ipsec pf_key</CODE>.</P> -</DD> -<DT>RUN_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode, before the packets are sent. On single machine tests, - this script doesn't provide any more power than INIT_SCRIPT, but is - implemented for consistency's sake.</P> -</DD> -<DT>FINAL_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode after the final packet is sent. Similar to - INIT_SCRIPT, above. If not specified, then the single command "halt" is - sent. If specified, then the script should end with a halt command to - nicely shutdown the UML.</P> -</DD> -<DT>CONSOLEDIFFDEBUG</DT> -<DD>If set to "true" then the series of console fixups (see - REF_CONSOLE_FIXUPS) will be output after it is constructed. (It should - be set to "false", or unset otherwise)</DD> -<DT>NETJIGDEBUG</DT> -<DD>If set to "true" then the series of console fixups (see - REF_CONSOLE_FIXUPS) will be output after it is constructed. (It should - be set to "false", or unset otherwise)</DD> -<DT>NETJIGTESTDEBUG</DT> -<DD> If set to "netjig", then the results of talking to the <CODE> -uml_netjig</CODE> will be printed to stderr during the test. In - addition, the jig will be invoked with --debug, which causes it to log - its process ID, and wait 60 seconds before continuing. This can be used - if you are trying to debug the <CODE>uml_netjig</CODE> program itself.</DD> -<DT>HOSTTESTDEBUG</DT> -<DD> If set to "hosttest", then the results of taling to the consoles of - the UMLs will be printed to stderr during the test.</DD> -<DT>NETJIGWAITUSER</DT> -<DD> If set to "waituser", then the scripts will wait forever for user - input before they shut the tests down. Use this is if you are debugging - through the kernel.</DD> -<DT>PACKETRATE</DT> -<DD> A number, in miliseconds (default is 500ms) at which packets will - be replayed by the netjig.</DD> -</DL> -<H2><A NAME="39_5">KLIPStest paramaters</A></H2> -<P> The klipstest function starts a program (<CODE> -testing/utils/uml_netjig/uml_netjig</CODE>) to setup a bunch of I/O - sockets (that simulate network interfaces). It then exports the - references to these sockets to the environment and invokes (using - system()) a given script. It waits for the script to finish.</P> - -<!-- <IMG SRC="single_netjig.png" ALT="block diagram of uml_netjig"> --> -<P> The script invoked (<CODE>testing/utils/host-test.tcl</CODE>) is a - TCL<A HREF="http://expect.nist.gov/"> expect</A> script that arranges - to start the UML and configure it appropriately for the test. The - configuration is done with the script given above for<VAR> INIT_SCRIPT</VAR> -. The TCL script then forks, leaves the UML in the background and exits. - uml_netjig continues. It then starts listening to the simulated network - answering ARPs and inserting packets as appropriate.</P> -<P> The klipstest function invokes <CODE>uml_netjig</CODE> with - arguments to capture output from network interface(s) and insert - packets as appropriate:</P> -<DL> -<DT>PUB_INPUT</DT> -<DD>a<A HREF="http://www.tcpdump.org/"> pcap</A> file to feed in on the - public (encrypted) interface. (typically, eth1)</DD> -<DT>PRIV_INPUT</DT> -<DD>a pcap file to feed in on the private (plain-text) interface - (typically, eth0).</DD> -<DT>REF_PUB_OUTPUT</DT> -<DD>a text file containing tcpdump output. Packets on the public (eth1) - interface are captured to a<A HREF="http://www.tcpdump.org/"> pcap</A> - file by <CODE>uml_netjig</CODE>. The klipstest function then uses - tcpdump on the file to produce text output, which is compared to the - file given.</DD> -<DT>REF_PUB_FILTER</DT> -<DD>a program that will filter the TCPDUMP output to do further - processing. Defaults to "cat".</DD> -<DT>REF_PRIV_OUTPUT</DT> -<DD>a text file containing tcpdump output. Packets on the private (eth0) - interface are captured and compared after conversion by tcpdump, as - with<VAR> REFPUBOUTPUT</VAR>.</DD> -<DT>REF_PRIV_FILTER</DT> -<DD>a program that will filter the TCPDUMP output to do further - processing. Defaults to "cat".</DD> -<DT>EXITONEMPTY</DT> -<DD>a flag for <CODE>uml_netjig</CODE>. It should contain - "--exitonempty" of uml_netjig should exit when all of the input (<VAR> -PUBINPUT</VAR>,<VAR>PRIVINPUT</VAR>) packets have been injected.</DD> -<DT>ARPREPLY</DT> -<DD>a flag for <CODE>uml_netjig</CODE>. It should contain "--arpreply" - if <CODE>uml_netjig</CODE> should reply to ARP requests. One will - typically set this to avoid having to fudge the ARP cache manually.</DD> -<DT>TCPDUMPFLAGS</DT> -<DD>a set of flags for the tcpdump used when converting captured output. - Typical values will include "-n" to turn off DNS, and often "-E" to set - the decryption key (tcpdump 3.7.1 and higher only) for ESP packets. The - "-t" flag (turn off timestamps) is provided automatically</DD> -<DT>NETJIG_EXTRA</DT> -<DD>additional comments to be sent to the netjig. This may arrange to - record or create additional networks, or may toggle options.</DD> -</DL> -<H2><A NAME="39_6">mkinsttest paramaters</A></H2> -<P> The basic concept of the <CODE>mkinsttest</CODE> test type is that - it performs a "make install" to a temporary $DESTDIR. The resulting - tree can then be examined to determine if it was done properly. The - files can be uninstalled to determine if the file list was correct, or - the contents of files can be examined more precisely.</P> -<DL> -<DT>INSTALL_FLAGS</DT> -<DD>If set, then an install will be done. This provides the set of flags - to provide for the install. The target to be used (usually "install") - must be among the flags.</DD> -<DT>POSTINSTALL_SCRIPT</DT> -<DD>If set, a script to run after initial "make install". Two arguments - are provided: an absolute path to the root of the FreeSWAN src tree, - and an absolute path to the temporary installation area.</DD> -<DT>INSTALL2_FLAGS</DT> -<DD>If set, a second install will be done using these flags. Similarly - to INSTALL_FLAGS, the target must be among the flags.</DD> -<DT>UNINSTALL_FLAGS</DT> -<DD>If set, an uninstall will be done using these flags. Similarly to - INSTALL_FLAGS, the target (usually "uninstall") must be among the - flags.</DD> -<DT>REF_FIND_f_l_OUTPUT</DT> -<DD>If set, a <CODE>find $ROOT ( -type f -or -type -l )</CODE> will be - done to get a list of a real files and symlinks. The resulting file - will be compared to the file listed by this option.</DD> -<DT>REF_FILE_CONTENTS</DT> -<DD>If set, it should point to a file containing records for the form: -<PRE> - -<!--VARIABLE--> -reffile</(null)> -<!--VARIABLE--> -samplefile</(null)> -</PRE> - one record per line. A diff between the provided reference file, and - the sample file (located in the temporary installation root) will be - done for each record.</DD> -</DL> -<H2><A NAME="39_7">rpm_build_install_test paramaters</A></H2> -<P> The <CODE>rpm_build_install_test</CODE> type is to verify that the - proper packing list is produced by "make rpm", and that the mechanisms - for building the kernel modules produce consistent results.</P> -<DL> -<DT>RPM_KERNEL_SOURCE</DT> -<DD>Point to an extracted copy of the RedHat kernel source code. - Variables from the environment may be used.</DD> -<DT>REF_RPM_CONTENTS</DT> -<DD>This is a file containing one record per line. Each record consists - of a RPM name (may contain wildcards) and a filename to compare the - contents to. The RPM will be located and a file list will be produced - with rpm2cpio.</DD> -</DL> -<H2><A NAME="39_8">libtest paramaters</A></H2> -<P> The libtest test is for testing library routines. The library file - is expected to provided an <CODE>#ifdef</CODE> by the name of<VAR> - library</VAR> -<!--CODE_MAIN</CODE--> -. The libtest type invokes the C compiler to compile this - file, links it against <CODE>libfreeswan.a</CODE> (to resolve any other - dependancies) and runs the test with the <CODE>-r</CODE> argument to - invoke a regression test.</(null)></P> -<P>The library test case is expected to do a self-test, exiting with - status code 0 if everything is okay, and with non-zero otherwise. A - core dump (exit code greater than 128) is noted specifically.</P> -<P> Unlike other tests, there are no subdirectories required, or other - parameters to set.</P> -<H2 NAME="umlplutotest"><A NAME="39_9">umlplutotest paramaters</A></H2> -<P> The umlplutotest function starts a pair of user mode line processes. - This is a 2-host version of umlXhost. The "EAST" and "WEST" slots are - defined.</P> -<H2 NAME="umlXhost"><A NAME="39_10">umlXhost parameters</A></H2> -<P> The umlXtest function starts an arbitrary number of user mode line - processes.</P> - -<!-- <IMG SRC="single_netjig.png" ALT="block diagram of uml_netjig"> --> -<P> The script invoked (<CODE>testing/utils/Xhost-test.tcl</CODE>) is a - TCL<A HREF="http://expect.nist.gov/"> expect</A> script that arranges - to start each UML and configure it appropriately for the test. It then - starts listening (using uml_netjig) to the simulated network answering - ARPs and inserting packets as appropriate.</P> -<P> umlXtest has a series of slots, each of which should be filled by a - host. The list of slots is controlled by the variable, XHOST_LIST. This - variable should be set to a space seperated list of slots. The former - umlplutotest is now implemented as a variation of the umlXhost test, - with XHOST_LIST="EAST WEST".</P> -<P> For each host slot that is defined, a series of variables should be - filled in, defining what configuration scripts to use for that host.</P> -<P> The following are used to control the console input and output to - the system. Where the string ${host} is present, the host slot should - be filled in. I.e. for the two host system with XHOST_LIST="EAST WEST", - then the variables: EAST_INIT_SCRIPT and WEST_INIT_SCRIPT will exist.</P> -<DL> -<DT>${host}HOST</DT> -<DD>The name of the UML host which will fill this slot</DD> -<DT>${host}_INIT_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode prior to starting the tests. This file will usually - set up any eroute's and SADB entries that are required for the test. - Similar to INIT_SCRIPT, above.</P> -</DD> -<DT>${host}_RUN_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode, before the packets are sent. This set of commands is - run after all of the virtual machines are initialized. I.e. after - EAST_INIT_SCRIPT<B> AND</B> WEST_INIT_SCRIPT. This script can therefore - do things that require that all machines are properly configured.</P> -</DD> -<DT>${host}_RUN2_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode, after the packets are sent. This set of commands is - run before any of the virtual machines have been shut down. (I.e. - before EAST_FINAL_SCRIPT<B> AND</B> WEST_FINAL_SCRIPT.) This script can - therefore catch post-activity status reports.</P> -</DD> -<DT>${host}_FINAL_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode after the final packet is sent. Similar to - INIT_SCRIPT, above. If not specified, then the single command "halt" is - sent. Note that when this script is run, the other virtual machines may - already have been killed. If specified, then the script should end with - a halt command to nicely shutdown the UML.</P> -</DD> -<DT>REF_${host}_CONSOLE_OUTPUT</DT> -<DD>Similar to REF_CONSOLE_OUTPUT, above.</DD> -</DL> -<P>Some additional flags apply to all hosts:</P> -<DL> -<DT>REF_CONSOLE_FIXUPS</DT> -<DD>a list of scripts (found in <CODE>klips/test/fixups</CODE>) to apply - to sanitize the console output of the machine under test. These are - typically perl, awk or sed scripts that remove things in the kernel - output that change each time the test is run and/or compiled.</DD> -</DL> -<P> In addition to input to the console, the networks may have input fed - to them:</P> -<DL> -<DT>EAST_INPUT/WEST_INPUT</DT> -<DD>a<A HREF="http://www.tcpdump.org/"> pcap</A> file to feed in on the - private network side of each network. The "EAST" and "WEST" here refer - to the networks, not the hosts.</DD> -<DT>REF_PUB_FILTER</DT> -<DD>a program that will filter the TCPDUMP output to do further - processing. Defaults to "cat".</DD> -<DT>REF_EAST_FILTER/REF_WEST_FILTER</DT> -<DD>a program that will filter the TCPDUMP output to do further - processing. Defaults to "cat".</DD> -< -<DT>TCPDUMPFLAGS</DT> -<DD>a set of flags for the tcpdump used when converting captured output. - Typical values will include "-n" to turn off DNS, and often "-E" to set - the decryption key (tcpdump 3.7.1 and higher only) for ESP packets. The - "-t" flag (turn off timestamps) is provided automatically</DD> -<DT>REF_EAST_OUTPUT/REF_WEST_OUTPUT</DT> -<DD>a text file containing tcpdump output. Packets on the private (eth0) - interface are captured and compared after conversion by tcpdump, as - with<VAR> REF_PUB_OUTPUT</VAR>.</DD> -<P> There are two additional environment variables that may be set on - the command line:</P> -<DL> -<DT> NETJIGVERBOSE=verbose export NETJIGVERBOSE</DT> -<DD> If set, then the test output will be "chatty", and let you know - what commands it is running, and as packets are sent. Without it set, - the output is limited to success/failure messages.</DD> -<DT> NETJIGTESTDEBUG=netjig export NETJIGTESTDEBUG</DT> -<DD> This will enable debugging of the communication with uml_netjig, - and turn on debugging in this utility. This does not imply - NETJIGVERBOSE.</DD> -</DL> -<DT> HOSTTESTDEBUG=hosttest export HOSTTESTDEBUG</DT> -<DD> This will show all interactions with the user-mode-linux consoles</DD> -</DL> -<H2 NAME="kernelpatch"><A NAME="39_11">kernel_patch_test paramaters</A></H2> -<P> The kernel_patch_test function takes some kernel source, copies it - with lndir, and then applies the patch as produced by "make - kernelpatch".</P> -<P> The following are used to control the input and output to the - system:</P> -<DL> -<DT>KERNEL_NAME</DT> -<DD>the kernel name, typically something like "linus" or "rh"</DD> -<DT>KERNEL_VERSION</DT> -<DD>the kernel version number, as in "2.2" or "2.4".</DD> -<DT>KERNEL_${KERNEL_NAME}${KERNEL_VERSION}_SRC</DT> -<DD>This variable should set in the environment, probably in - ~/freeswan-regress-env.sh. Examples of this variables would be - KERNEL_LINUS2_0_SRC or KERNEL_RH7_3_SRC. This variable should point to - an extracted copy of the kernel source in question.</DD> -<DT>REF_PATCH_OUTPUT</DT> -<DD>a copy of the patch output to compare against</DD> -<DT>KERNEL_PATCH_LEAVE_SOURCE</DT> -<DD>If set to a non-empty string, then the patched kernel source is not - removed at the end of the test. This will typically be set in the - environment while debugging.</DD> -</DL> -<H2 NAME="modtest"><A NAME="39_12">module_compile paramaters</A></H2> -<P> The module_compile test attempts to build the KLIPS module against a - given set of kernel source. This is also done by the RPM tests, but in - a very specific manner.</P> -<P> There are two variations of this test - one where the kernel either - doesn't need to be configured, or is already done, and tests were there - is a local configuration file.</P> -<P> Where the kernel doesn't need to be configured, the kernel source - that is found is simply used. It may be a RedHat-style kernel, where - one can cause it to configure itself via rhconfig.h-style definitions. - Or, it may just be a kernel tree that has been configured.</P> -<P> If the variable KERNEL_CONFIG_FILE is set, then a new directory is - created for the kernel source. It is populated with lndir(1). The - referenced file is then copied in as .config, and "make oldconfig" is - used to configure the kernel. This resulting kernel is then used as the - reference source.</P> -<P> In all cases, the kernel source is found the same was for the - kernelpatch test, i.e. via KERNEL_VERSION/KERNEL_NAME and - KERNEL_${KERNEL_NAME}${KERNEL_VERSION}_SRC.</P> -<P> Once there is kernel source, the module is compiled using the - top-level "make module" target.</P> -<P> The test is considered successful if an executable is found in - OUTPUT/module/ipsec.o at the end of the test.</P> -<DL> -<DT>KERNEL_NAME</DT> -<DD>the kernel name, typically something like "linus" or "rh"</DD> -<DT>KERNEL_VERSION</DT> -<DD>the kernel version number, as in "2.2" or "2.4".</DD> -<DT>KERNEL_${KERNEL_NAME}${KERNEL_VERSION}_SRC</DT> -<DD>This variable should set in the environment, probably in - ~/freeswan-regress-env.sh. Examples of this variables would be - KERNEL_LINUS2_0_SRC or KERNEL_RH7_3_SRC. This variable should point to - an extracted copy of the kernel source in question.</DD> -<DT>KERNEL_CONFIG_FILE</DT> -<DD>The configuration file for the kernel.</DD> -<DT>KERNEL_PATCH_LEAVE_SOURCE</DT> -<DD>If set to a non-empty string, then the configured kernel source is - not removed at the end of the test. This will typically be set in the - environment while debugging.</DD> -<DT>MODULE_DEF_INCLUDE</DT> -<DD>The include file that will be used to configure the KLIPS module, - and possibly the kernel source.</DD> -</DL> -<H1><A NAME="40">Current pitfalls</A></H1> -<DL> -<DT> "tcpdump dissector" not available.</DT> -<DD> This is a non-fatal warning. If uml_netjig is invoked with the -t - option, then it will attempt to use tcpdump's dissector to decode each - packet that it processes. The dissector is presently not available, so - this option it normally turned off at compile time. The dissector - library will be released with tcpdump version 4.0.</DD> -</DL> -<HR> -<H1><A name="nightly">Nightly regression testing</A></H1> -<P> The nightly regression testing system consists of several shell - scripts and some perl scripts. The goal is to check out a fresh tree, - run "make check" on it, record the results and summarize the results to - the team and to the web site.</P> -<P> Output can be found on<A HREF="http://bugs.freeswan.org:81/"> adams</A> -, although the tests are actually run on another project machine.</P> -<H1><A name="nightlyhowto">How to setup the nightly build</A></H1> -<P> The best way to do nightly testing is to setup a new account. We - call the account "build" - you could call it something else, but there - may still be some references to ~build in the scripts.</P> -<H2><A NAME="42_1"> Files you need to know about</A></H2> -<P> As few files as possible need to be extracted from the source tree - - files are run from the source tree whenever possible. However, there - are some bootstrap and configuration files that are necessary.</P> -<P> There are 7 files in testing/utils that are involved:</P> -<DL> -<DT> nightly-sample.sh</DT> -<DD> This is the root of the build process. This file should be copied - out of the CVS tree, to $HOME/bin/nightly.sh of the build account. This - file should be invoked from cron.</DD> -<DT> freeswan-regress-env-sample.sh</DT> -<DD> This file should be copied to $HOME/freeswan-regress-env.sh. It - should be edited to localize the values. See below.</DD> -<DT> regress-cleanup.pl</DT> -<DD> This file needs to be copied to $HOME/bin/regress-cleanup.pl. It is - invoked by the nightly file before doing anything else. It removes - previous nights builds in order to free up disk space for the build - about to be done.</DD> -<DT> teammail-sample.sh</DT> -<DD> A script used to send results email to the "team". This sample - script could be copied to $HOME/bin/teammail.sh. This version will PGP - encrypt all the output to the team members. If this script is used, - then PGP will have to be properly setup to have the right keys.</DD> -<DT> regress-nightly.sh</DT> -<DD> This is the first stage of the nightly build. This stage will call - other scripts as appropriate, and will extract the source code from - CVS. This script should be copied to $HOME/bin/regress-nightly.sh</DD> -<DT> regress-stage2.sh</DT> -<DD> This is the second stage of the nightly build. It is called in - place. It essentially sets up the UML setup in umlsetup.sh, and calls - "make check".</DD> -<DT> regress-summarize-results.pl</DT> -<DD> This script will summarize the results from the tests to a - permanent directory set by $REGRESSRESULTS. It is invoked from the - stage2 nightly script.</DD> -<DT> regress-chart.sh</DT> -<DD> This script is called at the end of the build process, and will - summarize each night's results (as saved into $REGRESSRESULTS by - regress-summarize-results.pl) as a chart using gnuplot. Note that this - requires at least gnuplot 3.7.2.</DD> -</DL> -<H2><A NAME="42_2">Configuring freeswan-regress-env.sh</A></H2> -<P>For more info on KERNPOOL, UMLPATCH, BASICROOT and SHAREDIR, see<A HREF="umltesting.html"> - User-Mode-Linux testing guide</A>.</P> -<DL> -<DT> KERNPOOL</DT> -<DD> Extract copy of some kernel source to be used for UML builds</DD> -<DT> UMLPATCH</DT> -<DD> matching User-Mode-Linux patch.</DD> -<DT> BASICROOT</DT> -<DD> the root file system image (see<A HREF="umltesting.html"> - User-Mode-Linux testing guide</A>).</DD> -<DT> SHAREDIR=${BASICROOT}/usr/share</DT> -<DD> The /usr/share to use.</DD> -<DT> REGRESSTREE</DT> -<DD> A directory in which to store the nightly regression results. - Directories will be created by date in this tree.</DD> -<DT> TCPDUMP=tcpdump-3.7.1</DT> -<DD> The path to the<A HREF="http://www.tcpdump.org/"> tcpdump</A> to - use. This must have crypto compiled in, and must be at least 3.7.1</DD> -<DT> KERNEL_RH7_2_SRC=/a3/kernel_sources/linux-2.4.9-13/</DT> -<DD> An extracted copy of the RedHat 7.2. kernel source. If set, then - the packaging/rpm-rh72-install-01 test will be run, and an RPM will be - built as a test.</DD> -<DT> KERNEL_RH7_3_SRC=/a3/kernel_sources/rh/linux-2.4.18-5</DT> -<DD> An extracted copy of the RedHat 7.3. kernel source. If set, then - the packaging/rpm-rh73-install-01 test will be run, and an RPM will be - built as a test.</DD> -<DT> NIGHTLY_WATCHERS="userid,userid,userid"</DT> -<DD> The list of people who should receive nightly output. This is used - by teammail.sh</DD> -<DT> FAILLINES=128</DT> -<DD> How many lines of failed test output to include in the nightly - output</DD> -<DT> PATH=$PATH:/sandel/bin export PATH</DT> -<DD> You can also override the path if necessary here.</DD> -<DT> CVSROOT=:pserver:anoncvs@ip212.xs4net.freeswan.org:/freeswan/MASTER</DT> -<DD> The CVSROOT to use. This example may work for anonymous CVS, but - will be 12 hours behind the primary, and is still experimental</DD> -<DT> SNAPSHOTSIGDIR=$HOME/snapshot-sig</DT> -<DD> For the release tools, where to put the generated per-snapshot - signature keys</DD> -<DT> LASTREL=1.97</DT> -<DD> the name of the last release branch (to find the right per-snapshot - signature</DD> -<DD></DD> -</DL> -</BODY> -</HTML> diff --git a/doc/Makefile b/doc/Makefile deleted file mode 100644 index f8209b3a8..000000000 --- a/doc/Makefile +++ /dev/null @@ -1,167 +0,0 @@ -# Makefile to generate various formats from HTML source -# -# Assumes the htmldoc utility is available. -# This can be downloaded from www.easysw.com -# -# Also needs lynx(1) for HTML-to-text conversion - -.SUFFIXES: .png .fig - -FREESWANSRCDIR=.. -include ${FREESWANSRCDIR}/Makefile.inc - -# Format arguments for htmldoc -F="--toclevels 4 --header 1cd" - -# source files in subdirectory -# basic stuff -a=src/intro.html src/upgrading.html src/quickstart.html \ - src/policygroups.html src/faq.html - -# related -b=src/manpages.html src/firewall.html src/trouble.html - -# more advanced -c=src/compat.html src/interop.html src/performance.html \ - src/testing.html src/kernel.html src/adv_config.html \ - src/install.html src/config.html \ - src/background.html src/user_examples.html \ - src/makecheck.html src/umltesting.html \ - -# background and reference material -d=src/politics.html src/ipsec.html \ - src/mail.html src/web.html src/glossary.html src/biblio.html \ - src/rfc.html src/roadmap.html - -# build and release related -e=src/umltesting.html src/makecheck.html src/nightly.html - -sections=$a $b $c $d $e - -# separate HTML files built in current directory -separate=intro.html install.html config.html manpages.html \ - firewall.html trouble.html kernel.html roadmap.html \ - compat.html interop.html politics.html ipsec.html \ - mail.html performance.html testing.html web.html \ - glossary.html biblio.html rfc.html faq.html \ - adv_config.html user_examples.html background.html \ - quickstart.html umltesting.html makecheck.html nightly.html \ - upgrading.html policygroups.html - -# various one-big-file formats -howto=HowTo.html HowTo.ps HowTo.pdf HowTo.txt - -alldocs=${seperate} ${howto} index.html toc.html - -srcdir=.. -# where are scripts -SCRIPTDIR=utils - -# where -TESTINGDIR=${srcdir}/testing - -# where do we put HTML manpages? -HMANDIR=manpage.d - -# default, build HTML only -# dependencies build most of it -# then we add index -index.html: toc.html HowTo.html manpages src/index.html - cp src/index.html index.html - -# separate files plus table of contents -# and then remove HTML formatting added by htmldoc -toc.html : $(sections) - @htmldoc -t html --path ".;${TESTINGDIR}/doc" -d . $(sections) - @$(SCRIPTDIR)/cleanhtml.sh $(SCRIPTDIR)/cleanhtml.sed $(separate) - -# one big HTML file -HowTo.html : $(sections) - @htmldoc -t html --toclevels 4 --header ' cf' -f $@ $(sections) - -# other HowTo formats -HowTo.txt: HowTo.html - lynx -dump $< > $@ - -HowTo.ps : $(sections) - htmldoc -f $@ $(sections) - -HowTo.pdf : $(sections) - @htmldoc -f $@ $(sections) - -manpages: manp - -manp: $(SCRIPTDIR)/mkhtmlman - @$(SCRIPTDIR)/mkhtmlman $(HMANDIR) `find ../programs ../lib ../linux -type f -name '*.[1-8]' -print | grep -v lwres | grep -v CVS` - -programs: - -all: #$(howto) $(manpages) index.html - -clean: - @rm -f $(howto) $(separate) toc.html index.html - @rm -rf $(HMANDIR) - -install: -#install: ${alldocs} manpages -# @mkdir -p ${DOCDIR} -# @$(foreach f, $(alldocs), \ -# $(INSTALL) $f ${DOCDIR} || exit 1;\ -# ) -# @find ${HMANDIR} -type f -name "*.html" -print | while read file; \ -# do \ -# $(INSTALL) $$file ${DOCDIR} || exit 1;\ -# done; - -install_file_list: - @$(foreach f, $(alldocs), \ - echo ${DOCDIR}/$f; \ - ) - @if [ -d ${HMANDIR} ]; then find ${HMANDIR} -type f -name "*.html" -print | while read file; \ - do \ - echo ${DOCDIR}/$$file; \ - done; fi; - -checkprograms: ; - -check: ; - -# not enabled by default, because xml2rfc must be installed first. -drafts: draft-richardson-ipsec-opportunistic.txt src/draft-richardson-ipsec-opportunistic.html \ - draft-richardson-ipsec-rr.txt src/draft-richardson-ipsec-rr.html - -draft-richardson-ipsec-opportunistic.txt: src/draft-richardson-ipsec-opportunistic.xml - XML_LIBRARY=$(XML_LIBRARY):./src xml2rfc xml2rfc $? $@ - -draft-richardson-ipsec-rr.txt: src/draft-richardson-ipsec-rr.xml - XML_LIBRARY=$(XML_LIBRARY):./src xml2rfc xml2rfc $? $@ - -draft-%.nr: src/draft-%.xml - XML_LIBRARY=$(XML_LIBRARY):./src xml2rfc xml2nroff $? $@ - -draft-%.html: draft-%.xml - XML_LIBRARY=$(XML_LIBRARY):./src xml2rfc xml2html $? $@ - - -.fig.eps: - fig2dev -L ps $< $@ - -.fig.png: - fig2dev -L png $< $@ - -single_netjig.png: testing/single_netjig.fig -multi_netjig.png: testing/multi_netjig.fig - -makecheck.html: single_netjig.png multi_netjig.png - -# -# DocBook based documentation -# -xmldocs: mast.html klips/mast.4 - -mast.html: klips/mast.xml - xmlto html klips/mast.xml - -klips/mast.4: klips/mast.xml - xmlto -o klips man klips/mast.xml - diff --git a/doc/adv_config.html b/doc/adv_config.html deleted file mode 100644 index 4b779c753..000000000 --- a/doc/adv_config.html +++ /dev/null @@ -1,1232 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="kernel.html">Previous</A> -<A HREF="install.html">Next</A> -<HR> -<H1><A name="adv_config">Other configuration possibilities</A></H1> -<P>This document describes various options for FreeS/WAN configuration - which are less used or more complex (often both) than the standard - cases described in our<A href="config.html#config"> config</A> and<A href="quickstart.html#quick_guide"> - quickstart</A> documents.</P> -<H2><A name="thumb">Some rules of thumb about configuration</A></H2> -<H3><A name="cheap.tunnel">Tunnels are cheap</A></H3> -<P>Nearly all of the overhead in IPsec processing is in the encryption - and authentication of packets. Our<A href="performance.html"> - performance</A> document discusses these overheads.</P> -<P>Beside those overheads, the cost of managing additional tunnels is - trivial. Whether your gateway supports one tunnel or ten just does not - matter. A hundred might be a problem; there is a<A href="performance.html#biggate"> - section</A> on this in the performance document.</P> -<P>So, in nearly all cases, if using multiple tunnels gives you a - reasonable way to describe what you need to do, you should describe it - that way in your configuration files.</P> -<P>For example, one user recently asked on a mailing list about this - network configuration:</P> -<PRE> netA---gwA---gwB---netB - |----netC - - netA and B are secured netC not. - netA and gwA can not access netC</PRE> -<P>The user had constructed only one tunnel, netA to netB, and wanted to - know how to use ip-route to get netC packets into it. This is entirely - unnecessary. One of the replies was:</P> -<PRE> The simplest way and indeed the right way to - solve this problem is to set up two connections: - - leftsubnet=NetA - left=gwA - right=gwB - rightsubnet=NetB - and - leftsubnet=NetA - left=gwA - right=gwB - rightsubnet=NetC</PRE> -<P>This would still be correct even if we added nets D, E, F, ... to the - above diagram and needed twenty tunnels.</P> -<P>Of course another possibility would be to just use one tunnel, with a - subnet mask that includes both netB and netC (or B, C, D, ...). See - next section.</P> -<P>In general, you can construct as many tunnels as you need. Networks - like netC in this example that do not connect directly to the gateway - are fine, as long as the gateway can route to them.</P> -<P>The number of tunnels can become an issue if it reaches 50 or so. - This is discussed in the<A href="performance.html#biggate"> performance</A> - document. Look there for information on supporting hundreds of Road - Warriors from one gateway.</P> -<P>If you find yourself with too many tunnels for some reason like - having eight subnets at one location and nine at another so you end up - with 9*8=72 tunnels, read the next section here.</P> -<H3><A name="subnet.size">Subnet sizes</A></H3> -<P>The subnets used in<VAR> leftsubnet</VAR> and<VAR> rightsubnet</VAR> - can be of any size that fits your needs, and they need not correspond - to physical networks.</P> -<P>You adjust the size by changing the<A href="glossary.html#subnet"> - subnet mask</A>, the number after the slash in the subnet description. - For example</P> -<UL> -<LI>in 192.168.100.0/24 the /24 mask says 24 bits are used to designate - the network. This leave 8 bits to label machines. This subnet has 256 - addresses. .0 and .255 are reserved, so it can have 254 machines.</LI> -<LI>A subnet with a /23 mask would be twice as large, 512 addresses.</LI> -<LI>A subnet with a /25 mask would be half the size, 128 addresses.</LI> -<LI>/0 is the whole Internet</LI> -<LI>/32 is a single machine</LI> -</UL> -<P>As an example of using these in connection descriptions, suppose your - company's head office has four physical networks using the address - ranges:</P> -<DL> -<DT>192.168.100.0/24</DT> -<DD>development</DD> -<DT>192.168.101.0/24</DT> -<DD>production</DD> -<DT>192.168.102.0/24</DT> -<DD>marketing</DD> -<DT>192.168.103.0/24</DT> -<DD>administration</DD> -</DL> -<P>You can use exactly those subnets in your connection descriptions, or - use larger subnets to grant broad access if required:</P> -<DL> -<DT>leftsubnet=192.168.100.0/24</DT> -<DD>remote hosts can access only development</DD> -<DT>leftsubnet=192.168.100.0/23</DT> -<DD>remote hosts can access development or production</DD> -<DT>leftsubnet=192.168.102.0/23</DT> -<DD>remote hosts can access marketing or administration</DD> -<DT>leftsubnet=192.168.100.0/22</DT> -<DD>remote hosts can access any of the four departments</DD> -</DL> -<P>or use smaller subnets to restrict access:</P> -<DL> -<DT>leftsubnet=192.168.103.0/24</DT> -<DD>remote hosts can access any machine in administration</DD> -<DT>leftsubnet=192.168.103.64/28</DT> -<DD>remote hosts can access only certain machines in administration.</DD> -<DT>leftsubnet=192.168.103.42/32</DT> -<DD>remote hosts can access only one particular machine in - administration</DD> -</DL> -<P>To be exact, 192.68.103.64/28 means all addresses whose top 28 bits - match 192.168.103.64. There are 16 of these because there are 16 - possibilities for the remainingg 4 bits. Their addresses are - 192.168.103.64 to 192.168.103.79.</P> -<P>Each connection description can use a different subnet if required.</P> -<P>It is possible to use all the examples above on the same FreeS/WAN - gateway, each in a different connection description, perhaps for - different classes of user or for different remote offices.</P> -<P>It is also possible to have multiple tunnels using different<VAR> - leftsubnet</VAR> descriptions with the same<VAR> right</VAR>. For - example, when the marketing manager is on the road he or she might have - access to:</P> -<DL> -<DT>leftsubnet=192.168.102.0/24</DT> -<DD>all machines in marketing</DD> -<DT>192.168.101.32/29</DT> -<DD>some machines in production</DD> -<DT>leftsubnet=192.168.103.42/32</DT> -<DD>one particular machine in administration</DD> -</DL> -<P>This takes three tunnels, but tunnels are cheap. If the laptop is set - up to build all three tunnels automatically, then he or she can access - all these machines concurrently, perhaps from different windows.</P> -<H3><A name="example.more">Other network layouts</A></H3> -<P>Here is the usual network picture for a site-to-site VPN::</P> -<PRE> Sunset==========West------------------East=========Sunrise - local net untrusted net local net</PRE> -<P>and for the Road Warrior::</P> -<PRE> telecommuter's PC or - traveller's laptop - Sunset==========West------------------East - corporate LAN untrusted net</PRE> -<P>Other configurations are also possible.</P> -<H4><A name="internet.subnet">The Internet as a big subnet</A></H4> -<P>A telecommuter might have:</P> -<PRE> Sunset==========West------------------East ================= firewall --- the Internet - home network untrusted net corporate network</PRE> -<P>This can be described as a special case of the general - subnet-to-subnet connection. The subnet on the right is 0.0.0.0/0, the - whole Internet.</P> -<P>West (the home gateway) can have its firewall rules set up so that - only IPsec packets to East are allowed out. It will then behave as if - its only connection to the world was a wire to East.</P> -<P>When machines on the home network need to reach the Internet, they do - so via the tunnel, East and the corporate firewall. From the viewpoint - of the Internet (perhaps of some EvilDoer trying to break in!), those - home office machines are behind the firewall and protected by it.</P> -<H4><A name="wireless.config">Wireless</A></H4> -<P>Another possible configuration comes up when you do not trust the - local network, either because you have very high security standards or - because your are using easily-intercepted wireless signals.</P> -<P>Some wireless networks have built-in encryption called<A href="glossary.html#WEP"> - WEP</A>, but its security is dubious. It is a fairly common practice to - use IPsec instead.</P> -<P>In this case, part of your network may look like this:</P> -<PRE> West-----------------------------East == the rest of your network - workstation untrusted wireless net</PRE> -<P>Of course, there would likely be several wireless workstations, each - with its own IPsec tunnel to the East gateway.</P> -<P>The connection descriptions look much like Road Warrior descriptions:</P> -<UL> -<LI>each workstation should have its own unique -<UL> -<LI>identifier for IPsec</LI> -<LI>RSA key</LI> -<LI>connection description.</LI> -</UL> -</LI> -<LI>on the gateway, use<VAR> left=%any</VAR>, or the workstation IP - address</LI> -<LI>on workstations,<VAR> left=%defaultroute</VAR>, or the workstation - IP address</LI> -<LI><VAR>leftsubnet=</VAR> is not used.</LI> -</UL> -<P>The<VAR> rightsubnet=</VAR> parameter might be set in any of several - ways:</P> -<DL> -<DT>rightsubnet=0.0.0.0/0</DT> -<DD>allowing workstations to access the entire Internet (see<A href="#internet.subnet"> - above</A>)</DD> -<DT>rightsubnet=a.b.c.0/24</DT> -<DD>allowing access to your entire local network</DD> -<DT>rightsubnet=a.b.c.d/32</DT> -<DD>restricting the workstation to connecting to a particular server</DD> -</DL> -<P>Of course you can mix and match these as required. For example, a - university might allow faculty full Internet access while letting - student laptops connect only to a group of lab machines.</P> -<H2><A name="choose">Choosing connection types</A></H2> -<P>One choice you need to make before configuring additional connections - is what type or types of connections you will use. There are several - options, and you can use more than one concurrently.</P> -<H3><A name="man-auto">Manual vs. automatic keying</A></H3> -<P>IPsec allows two types of connections, with manual or automatic - keying. FreeS/WAN starts them with commands such as:</P> -<PRE> ipsec manual --up <VAR>name</VAR> - ipsec auto --up <VAR>name</VAR></PRE> -<P>The difference is in how they are keyed.</P> -<DL> -<DT><A href="glossary.html#manual">Manually keyed</A> connections</DT> -<DD>use keys stored in<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf</A> -.</DD> -<DT><A href="glossary.html#auto">Automatically keyed</A> connections</DT> -<DD>use keys automatically generated by the Pluto key negotiation - daemon. The key negotiation protocol,<A href="glossary.html#IKE"> IKE</A> -, must authenticate the other system. (It is vulnerable to a<A href="glossary.html#middle"> - man-in-the-middle attack</A> if used without authentication.) We - currently support two authentication methods: -<UL> -<LI>using shared secrets stored in<A href="manpage.d/ipsec.secrets.5.html"> - ipsec.secrets</A>.</LI> -<LI>RSA<A href="glossary.html#public"> public key</A> authentication, - with our machine's private key in<A href="manpage.d/ipsec.secrets.5.html"> - ipsec.secrets</A>. Public keys for other machines may either be placed - in<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf</A> or provided via - DNS.</LI> -</UL> -<P>A third method, using RSA keys embedded in<A href="glossary.html#X509"> - X.509</A> certtificates, is provided by user<A href="web.html#patch"> - patches</A>.</P> -</DD> -</DL> -<P><A href="glossary.html#manual">Manually keyed</A> connections provide - weaker security than<A href="glossary.html#auto"> automatically keyed</A> - connections. An opponent who reads ipsec.secrets(5) gets your - encryption key and can read all data encrypted by it. If he or she has - an archive of old messages, all of them back to your last key change - are also readable.</P> -<P>With automatically-(re)-keyed connections, an opponent who reads - ipsec.secrets(5) gets the key used to authenticate your system in IKE - -- the shared secret or your private key, depending what authentication - mechanism is in use. However, he or she does not automatically gain - access to any encryption keys or any data.</P> -<P>An attacker who has your authentication key can mount a<A href="glossary.html#middle"> - man-in-the-middle attack</A> and, if that succeeds, he or she will get - encryption keys and data. This is a serious danger, but it is better - than having the attacker read everyting as soon as he or she breaks - into ipsec.secrets(5).. Moreover, the keys change often so an opponent - who gets one key does not get a large amount of data. To read all your - data, he or she would have to do a man-in-the-middle attack at every - key change.</P> -<P>We discuss using<A href="#prodman"> manual keying in production</A> - below, but this is<STRONG> not recommended</STRONG> except in special - circumstances, such as needing to communicate with some implementation - that offers no auto-keyed mode compatible with FreeS/WAN.</P> -<P>Manual keying may also be useful for testing. There is some - discussion of this in our<A href="faq.html#man4debug"> FAQ</A>.</P> -<H3><A name="auto-auth">Authentication methods for auto-keying</A></H3> -<P>The IKE protocol which Pluto uses to negotiate connections between - gateways must use some form of authentication of peers. A gateway must - know who it is talking to before it can create a secure connection. We - support two basic methods for this authentication:</P> -<UL> -<LI>shared secrets, stored in<A href="manpage.d/ipsec.secrets.5.html"> - ipsec.secrets(5)</A></LI> -<LI>RSA authentication</LI> -</UL> -<P>There are, howver, several variations on the RSA theme, using - different methods of managing the RSA keys:</P> -<UL> -<LI>our RSA private key in<A href="manpage.d/ipsec.secrets.5.html"> - ipsec.secrets(5)</A> with other gateways' public keys -<DL> -<DT>either</DT> -<DD>stored in<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5)</A></DD> -<DT>or</DT> -<DD>looked up via<A href="glossary.html#DNS"> DNS</A></DD> -</DL> -</LI> -<LI>authentication with<A href="glossary.html#x509"> x.509</A> - certificates.; See our<A href="web.html#patch"> links section</A> for - information on user-contributed patches for this.:</LI> -</UL> -<P>Public keys in<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5</A> -) give a reasonably straightforward method of specifying keys for - explicitly configured connections.</P> -<P>Putting public keys in DNS allows us to support<A href="glossary.html#carpediem"> - opportunistic encryption</A>. Any two FreeS/WAN gateways can provide - secure communication, without either of them having any preset - information about the other.</P> -<P>X.509 certificates may be required to interface to various<A href="glossary.html#PKI"> - PKI</A>s.</P> -<H3><A name="adv-pk">Advantages of public key methods</A></H3> -<P>Authentication with a<A href="glossary.html#public"> public key</A> - method such as<A href="glossary.html#RSA"> RSA</A> has some important - advantages over using shared secrets.</P> -<UL> -<LI>no problem of secure transmission of secrets -<UL> -<LI>A shared secret must be shared, so you have the problem of - transmitting it securely to the other party. If you get this wrong, you - have no security.</LI> -<LI>With a public key technique, you transmit only your public key. The - system is designed to ensure that it does not matter if an enemy - obtains public keys. The private key never leaves your machine.</LI> -</UL> -</LI> -<LI>easier management -<UL> -<LI>Suppose you have 20 branch offices all connecting to one gateway at - head office, and all using shared secrets. Then the head office admin - has 20 secrets to manage. Each of them must be kept secret not only - from outsiders, but also from 19 of the branch office admins. The - branch office admins have only one secret each to manage. -<P>If the branch offices need to talk to each other, this becomes - problematic. You need another 20*19/2 = 190 secrets for - branch-to-branch communication, each known to exactly two branches. Now - all the branch admins have the headache of handling 20 keys, each - shared with exactly one other branch or with head office.</P> -<P>For larger numbers of branches, the number of connections and secrets - increases quadratically and managing them becomes a nightmare. A - 1000-gateway fully connected network needs 499,500 secrets, each known - to exactly two players. There are ways to reduce this problem, for - example by introducing a central key server, but these involve - additional communication overheads, more administrative work, and new - threats that must be carefully guarded against.</P> -</LI> -<LI>With public key techniques, the<EM> only</EM> thing you have to keep - secret is your private key, and<EM> you keep that secret from everyone</EM> -. -<P>As network size increaes, the number of public keys used increases - linearly with the number of nodes. This still requires careful - administration in large applications, but is nothing like the disaster - of a quadratic increase. On a 1000-gateway network, you have 1000 - private keys, each of which must be kept secure on one machine, and - 1000 public keys which must be distributed. This is not a trivial - problem, but it is manageable.</P> -</LI> -</UL> -</LI> -<LI>does not require fixed IP addresses -<UL> -<LI>When shared secrets are used in IPsec, the responder must be able to - tell which secret to use by looking at the IP address on the incoming - packets. When the other parties do not have a fixed IP address to be - identified by (for example, on nearly all dialup ISP connections and - many cable or ADSL links), this does not work well -- all must share - the same secret!</LI> -<LI>When RSA authentication is in use, the initiator can identify itself - by name before the key must be determined. The responder then checks - that the message is signed with the public key corresponding to that - name.</LI> -</UL> -</LI> -</UL> -<P>There is also a disadvantage:</P> -<UL> -<LI>your private key is a single point of attack, extremely valuable to - an enemy -<UL> -<LI>with shared secrets, an attacker who steals your ipsec.secrets file - can impersonate you or try<A href="glossary.html#middle"> - man-in-the-middle</A> attacks, but can only attack connections - described in that file</LI> -<LI>an attacker who steals your private key gains the chance to attack - not only existing connections<EM> but also any future connections</EM> - created using that key</LI> -</UL> -</LI> -</UL> -<P>This is partly counterbalanced by the fact that the key is never - transmitted and remains under your control at all times. It is likely - necessary, however, to take account of this in setting security policy. - For example, you should change gateway keys when an administrator - leaves the company, and should change them periodically in any case.</P> -<P>Overall, public key methods are<STRONG> more secure, more easily - managed and more flexible</STRONG>. We recommend that they be used for - all connections, unless there is a compelling reason to do otherwise.</P> -<H2><A name="prodsecrets">Using shared secrets in production</A></H2> -<P>Generally, public key methods are preferred for reasons given above, - but shared secrets can be used with no loss of security, just more work - and perhaps more need to take precautions.</P> -<P>What I call "shared secrets" are sometimes also called "pre-shared - keys". They are used only for for authentication, never for encryption. - Calling them "pre-shared keys" has confused some users into thinking - they were encryption keys, so I prefer to avoid the term..</P> -<P>If you are interoperating with another IPsec implementation, you may - find its documentation calling them "passphrases".</P> -<H3><A name="secrets">Putting secrets in ipsec.secrets(5)</A></H3> -<P>If shared secrets are to be used to<A href="glossary.html#authentication"> - authenticate</A> communication for the<A href="glossary.html#DH"> - Diffie-Hellman</A> key exchange in the<A href="glossary.html#IKE"> IKE</A> - protocol, then those secrets must be stored in<VAR> /etc/ipsec.secrets</VAR> -. For details, see the<A href="manpage.d/ipsec.secrets.5.html"> - ipsec.secrets(5)</A> man page.</P> -<P>A few considerations are vital:</P> -<UL> -<LI>make the secrets long and unguessable. Since they need not be - remembered by humans, very long ugly strings may be used. We suggest - using our<A href="manpage.d/ipsec_ranbits.8.html"> ipsec_ranbits(8)</A> - utility to generate long (128 bits or more) random strings.</LI> -<LI>transmit secrets securely. You have to share them with other - systems, but you lose if they are intercepted and used against you. Use<A -href="glossary.html#PGP"> PGP</A>,<A href="glossary.html#SSH"> SSH</A>, - hand delivery of a floppy disk which is then destroyed, or some other - trustworthy method to deliver them.</LI> -<LI>store secrets securely, in root-owned files with permissions - rw------.</LI> -<LI>limit sharing of secrets. Alice, Bob, Carol and Dave may all talk to - each other, but only Alice and Bob should know the secret for an - Alice-Bob link.</LI> -<LI><STRONG>do not share private keys</STRONG>. The private key for RSA - authentication of your system is stored in<A href="manpage.d/ipsec.secrets.5.html"> - ipsec.secrets(5)</A>, but it is a different class of secret from the - pre-shared keys used for the "shared secret" authentication. No-one but - you should have the RSA private key.</LI> -</UL> -<P>Each line has the IP addresses of the two gateways plus the secret. - It should look something like this:</P> -<PRE> 10.0.0.1 11.0.0.1 : PSK "jxTR1lnmSjuj33n4W51uW3kTR55luUmSmnlRUuWnkjRj3UuTV4T3USSu23Uk55nWu5TkTUnjT"</PRE> -<P><VAR>PSK</VAR> indicates the use of a<STRONG> p</STRONG>re-<STRONG>s</STRONG> -hared<STRONG> k</STRONG>ey. The quotes and the whitespace shown are - required.</P> -<P>You can use any character string as your secret. For security, it - should be both long and extremely hard to guess. We provide a utility - to generate such strings,<A href="manpage.d/ipsec_ranbits.8.html"> - ipsec_ranbits(8)</A>.</P> -<P>You want the same secret on the two gateways used, so you create a - line with that secret and the two gateway IP addresses. The - installation process supplies an example secret, useful<EM> only</EM> - for testing. You must change it for production use.</P> -<H3><A name="securing.secrets">File security</A></H3> -<P>You must deliver this file, or the relevant part of it, to the other - gateway machine by some<STRONG> secure</STRONG> means.<EM> Don't just - FTP or mail the file!</EM> It is vital that the secrets in it remain - secret. An attacker who knew those could easily have<EM> all the data - on your "secure" connection</EM>.</P> -<P>This file must be owned by root and should have permissions<VAR> - rw-------</VAR>.</P> -<H3><A name="notroadshared">Shared secrets for road warriors</A></H3> -<P>You can use a shared secret to support a single road warrior - connecting to your gateway, and this is a reasonable thing to do in - some circumstances. Public key methods have advantages, discussed<A href="#choose"> - above</A>, but they are not critical in this case.</P> -<P>To do this, the line in ipsec.secrets(5) is something like:</P> -<PRE> 10.0.0.1 0.0.0.0 : PSK "jxTR1lnmSjuj33n4W51uW3kTR55luUmSmnlRUuWnkjRj3UuTV4T3USSu23Uk55nWu5TkTUnjT"</PRE> - where the<VAR> 0.0.0.0</VAR> means that any IP address is acceptable. -<P><STRONG>For more than one road warrior, shared secrets are<EM> not</EM> - recommended.</STRONG> If shared secrets are used, then when the - responder needs to look up the secret, all it knows about the sender is - an IP address. This is fine if the sender is at a fixed IP address - specified in the config file. It is also fine if only one road warrior - uses the wildcard<VAR> 0.0.0.0</VAR> address. However, if you have more - than one road warrior using shared secret authentication, then they - must all use that wildcard and therefore<STRONG> all road warriors - using PSK autentication must use the same secret</STRONG>. Obviously, - this is insecure.</P> -<P><STRONG>For multiple road warriors, use public key authentication.</STRONG> - Each roadwarrior can then have its own identity (our<VAR> leftid=</VAR> - or<VAR> rightid=</VAR> parameters), its own public/private key pair, - and its own secure connection.</P> -<H2><A name="prodman">Using manual keying in production</A></H2> -<P>Generally,<A href="glossary.html#auto"> automatic keying</A> is - preferred over<A href="glossary.html#manual"> manual keying</A> for - production use because it is both easier to manage and more secure. - Automatic keying frees the admin from much of the burden of managing - keys securely, and can provide<A href="glossary.html#PFS"> perfect - forward secrecy</A>. This is discussed in more detail<A href="#man-auto"> - above</A>.</P> -<P>However, it is possible to use manual keying in production if that is - what you want to do. This might be necessary, for example, in order to - interoperate with some device that either does not provide automatic - keying or provides it in some version we cannot talk to.</P> -<P>Note that with manual keying<STRONG> all security rests with the keys</STRONG> -. If an adversary acquires your keys, you've had it. He or she can read - everything ever sent with those keys, including old messages he or she - may have archived.</P> -<P>You need to<STRONG> be really paranoid about keys</STRONG> if you're - going to rely on manual keying for anything important.</P> -<UL> -<LI>keep keys in files with 600 permissions, owned by root</LI> -<LI>be extremely careful about security of your gateway systems. Anyone - who breaks into a gateway and gains root privileges can get all your - keys and read everything ever encrypted with those keys, both old - messages he has archived and any new ones you may send.</LI> -<LI>change keys regularly. This can be a considerable bother, (and - provides an excellent reason to consider automatic keying instead), but - it is<EM> absolutely essential</EM> for security. Consider a manually - keyed system in which you leave the same key in place for months: -<UL> -<LI>an attacker can have a very large sample of text sent with that key - to work with. This makes various cryptographic attacks much more likely - to succeed.</LI> -<LI>The chances of the key being compromised in some non-cryptographic - manner -- a spy finds it on a discarded notepad, someone breaks into - your server or your building and steals it, a staff member is bribed, - tricked, seduced or coerced into revealing it, etc. -- also increase - over time.</LI> -<LI>a successful attacker can read everything ever sent with that key. - This makes any successful attack extremely damaging.</LI> -</UL> - It is clear that you must change keys often to have any useful - security. The only question is how often.</LI> -<LI>use<A href="glossary.html#PGP"> PGP</A> or<A href="glossary.html#SSH"> - SSH</A> for all key transfers</LI> -<LI>don't edit files with keys in them when someone can look over your - shoulder</LI> -<LI>worry about network security; could someone get keys by snooping - packets on the LAN between your X desktop and the gateway?</LI> -<LI>lock up your backup tapes for the gateway system</LI> -<LI>... and so on</LI> -</UL> -<P>Linux FreeS/WAN provides some facilities to help with this. In - particular, it is good policy to<STRONG> keep keys in separate files</STRONG> - so you can edit configuration information in /etc/ipsec.conf without - exposing keys to "shoulder surfers" or network snoops. We support this - with the<VAR> also=</VAR> and<VAR> include</VAR> syntax in<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A>.</P> -<P>See the last example in our<A href="examples"> examples</A> file. In - the /etc/ipsec.conf<VAR> conn samplesep</VAR> section, it has the line:</P> -<PRE> also=samplesep-keys</PRE> -<P>which tells the "ipsec manual" script to insert the configuration - description labelled "samplesep-keys" if it can find it. The - /etc/ipsec.conf file must also have a line such as:</P> -<PRE>include ipsec.*.conf</PRE> -<P>which tells it to read other files. One of those other files then - might contain the additional data:</P> -<PRE>conn samplesep-keys - spi=0x200 - esp=3des-md5-96 - espenckey=0x01234567_89abcdef_02468ace_13579bdf_12345678_9abcdef0 - espauthkey=0x12345678_9abcdef0_2468ace0_13579bdf</PRE> -<P>The first line matches the label in the "also=" line, so the indented - lines are inserted. The net effect is exactly as if the inserted lines - had occurred in the original file in place of the "also=" line.</P> -<P>Variables set here are:</P> -<DL> -<DT>spi</DT> -<DD>A number needed by the manual keying code. Any 3-digit hex number - will do, but if you have more than one manual connection then<STRONG> - spi must be different</STRONG> for each connection.</DD> -<DT>esp</DT> -<DD>Options for<A href="glossary.html#ESP"> ESP</A> (Encapsulated - Security Payload), the usual IPsec encryption mode. Settings here are - for<A href="glossary.html#encryption"> encryption</A> using<A href="glossary.html#3DES"> - triple DES</A> and<A href="glossary.html#authentication"> - authentication</A> using<A href="glossary.html#MD5"> MD5</A>. Note that - encryption without authentication should not be used; it is insecure.</DD> -<DT>espenkey</DT> -<DD>Key for ESP encryption. Here, a 192-bit hex number for triple DES.</DD> -<DT>espauthkey</DT> -<DD>Key for ESP authentication. Here, a 128-bit hex number for MD5.</DD> -</DL> -<P><STRONG>Note</STRONG> that the<STRONG> example keys we supply</STRONG> - are intended<STRONG> only for testing</STRONG>. For real use, you - should go to automatic keying. If that is not possible, create your own - keys for manual mode and keep them secret</P> -<P>Of course, any files containing keys<STRONG> must</STRONG> have 600 - permissions and be owned by root.</P> -<P>If you connect in this way to multiple sites, we recommend that you - keep keys for each site in a separate file and adopt some naming - convention that lets you pick them all up with a single "include" line. - This minimizes the risk of losing several keys to one error or attack - and of accidentally giving another site admin keys which he or she has - no business knowing.</P> -<P>Also note that if you have multiple manually keyed connections on a - single machine, then the<VAR> spi</VAR> parameter must be different for - each one. Any 3-digit hex number is OK, provided they are different for - each connection. We reserve the range 0x100 to 0xfff for manual - connections. Pluto assigns SPIs from 0x1000 up for automatically keyed - connections.</P> -<P>If<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5)</A> contains - keys for manual mode connections, then it too must have permissions<VAR> - rw-------</VAR>. We recommend instead that, if you must manual keying - in production, you keep the keys in separate files.</P> -<P>Note also that<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf</A> - is installed with permissions<VAR> rw-r--r--</VAR>. If you plan to use - manually keyed connections for anything more than initial testing, you<B> - must</B>:</P> -<UL> -<LI>either change permissions to<VAR> rw-------</VAR></LI> -<LI>or store keys separately in secure files and access them via include - statements in<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf</A>.</LI> -</UL> -<P>We recommend the latter method for all but the simplest - configurations.</P> -<H3><A name="ranbits">Creating keys with ranbits</A></H3> -<P>You can create new<A href="glossary.html#random"> random</A> keys - with the<A href="manpage.d/ipsec_ranbits.8.html"> ranbits(8)</A> - utility. For example, the commands:</P> -<PRE> umask 177 - ipsec ranbits 192 > temp - ipsec ranbits 128 >> temp</PRE> -<P>create keys in the sizes needed for our default algorithms:</P> -<UL> -<LI>192-bit key for<A href="glossary.html#3DES"> 3DES</A> encryption -<BR> (only 168 bits are used; parity bits are ignored)</LI> -<LI>128-bit key for keyed<A href="glossary.html#MD5"> MD5</A> - authentication</LI> -</UL> -<P>If you want to use<A href="glossary.html#SHA"> SHA</A> instead of<A href="glossary.html#MD5"> - MD5</A>, that requires a 160-bit key</P> -<P>Note that any<STRONG> temporary files</STRONG> used must be kept<STRONG> - secure</STRONG> since they contain keys. That is the reason for the - umask command above. The temporary file should be deleted as soon as - you are done with it. You may also want to change the umask back to its - default value after you are finished working on keys.</P> -<P>The ranbits utility may pause for a few seconds if not enough entropy - is available immediately. See ipsec_ranbits(8) and random(4) for - details. You may wish to provide some activity to feed entropy into the - system. For example, you might move the mouse around, type random - characters, or do<VAR> du /usr > /dev/null</VAR> in the background.</P> -<H2><A name="boot">Setting up connections at boot time</A></H2> -<P>You can tell the system to set up connections automatically at boot - time by putting suitable stuff in /etc/ipsec.conf on both systems. The - relevant section of the file is labelled by a line reading<VAR> config - setup</VAR>.</P> -<P>Details can be found in the<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A> man page. We also provide a file of<A href="examples"> - example configurations</A>.</P> -<P>The most likely options are something like:</P> -<DL> -<DT>interfaces="ipsec0=eth0 ipsec1=ppp0"</DT> -<DD>Tells KLIPS which interfaces to use. Up to four interfaces numbered - ipsec[0-3] are supported. Each interface can support an arbitrary - number of tunnels. -<P>Note that for PPP, you give the ppp[0-9] device name here, not the - underlying device such as modem (or eth1 if you are using PPPoE).</P> -</DD> -<DT>interfaces=%defaultroute</DT> -<DD>Alternative setting, useful in simple cases. KLIPS will pick up both - its interface and the next hop information from the settings of the - Linux default route.</DD> -<DT>forwardcontrol=no</DT> -<DD>Normally "no". Set to "yes" if the IP forwarding option is disabled - in your network configuration. (This can be set as a kernel - configuration option or later. e.g. on Redhat, it's in - /etc/sysconfig/network and on SuSE you can adjust it with Yast.) Linux - FreeS/WAN will then enable forwarding when starting up and turn it off - when going down. This is used to ensure that no packets will be - forwarded before IPsec comes up and takes control.</DD> -<DT>syslog=daemon.error</DT> -<DD>Used in messages to the system logging daemon (syslogd) to specify - what type of software is sending the messages. If the settings are - "daemon.error" as in our example, then syslogd treats the messages as - error messages from a daemon. -<P>Note that<A href="glossary.html#Pluto"> Pluto</A> does not currently - pay attention to this variable. The variable controls setup messages - only.</P> -</DD> -<DT>klipsdebug=</DT> -<DD>Debug settings for<A href="glossary.html#KLIPS"> KLIPS</A>.</DD> -<DT>plutodebug=</DT> -<DD>Debug settings for<A href="glossary.html#Pluto"> Pluto</A>.</DD> -<DT>... for both the above DEBUG settings</DT> -<DD>Normally, leave empty as shown above for no debugging output. -<BR> Use "all" for maximum information. -<BR> See ipsec_klipsdebug(8) and ipsec_pluto(8) man page for other - options. Beware that if you set /etc/ipsec.conf to enable debug output, - your system's log files may get large quickly.</DD> -<DT>dumpdir=/safe/directory</DT> -<DD>Normally, programs started by ipsec setup don't crash. If they do, - by default, no core dump will be produced because such dumps would - contain secrets. If you find you need to debug such crashes, you can - set dumpdir to the name of a directory in which to collect the core - file.</DD> -<DT>manualstart=</DT> -<DD>List of manually keyed connections to be automatically started at - boot time. Useful for testing, but not for long term use. Connections - which are automatically started should also be automatically re-keyed.</DD> -<DT>pluto=yes</DT> -<DD>Whether to start<A href="glossary.html#Pluto"> Pluto</A> when ipsec - startup is done. -<BR> This parameter is optional and defaults to "yes" if not present. -<P>"yes" is strongly recommended for production use so that the keying - daemon (Pluto) will automatically re-key the connections regularly. The - ipsec-auto parameters ikelifetime, ipseclifetime and reykeywindow give - you control over frequency of rekeying.</P> -</DD> -<DT>plutoload="reno-van reno-adam reno-nyc"</DT> -<DD>List of tunnels (by name, e.g. fred-susan or reno-van in our - examples) to be loaded into Pluto's internal database at startup. In - this example, Pluto loads three tunnels into its database when it is - started. -<P>If plutoload is "%search", Pluto will load any connections whose - description includes "auto=add" or "auto=start".</P> -</DD> -<DT>plutostart="reno-van reno-adam reno-nyc"</DT> -<DD>List of tunnels to attempt to negotiate when Pluto is started. -<P>If plutostart is "%search", Pluto will start any connections whose - description includes "auto=start".</P> -<P>Note that, for a connection intended to be permanent,<STRONG> both - gateways should be set try to start</STRONG> the tunnel. This allows - quick recovery if either gateway is rebooted or has its IPsec - restarted. If only one gateway is set to start the tunnel and the other - gateway restarts, the tunnel may not be rebuilt.</P> -</DD> -<DT>plutowait=no</DT> -<DD>Controls whether Pluto waits for one tunnel to be established before - starting to negotiate the next. You might set this to "yes" -<UL> -<LI>if your gateway is a very limited machine and you need to conserve - resources.</LI> -<LI>for debugging; the logs are clearer if only one connection is - brought up at a time</LI> -</UL> - For a busy and resource-laden production gateway, you likely want "no" - so that connections are brought up in parallel and the whole process - takes less time.</DD> -</DL> -<P>The example assumes you are at the Reno office and will use IPsec to - Vancouver, New York City and Amsterdam.</P> -<H2><A name="multitunnel">Multiple tunnels between the same two gateways</A> -</H2> -<P>Consider a pair of subnets, each with a security gateway, connected - via the Internet:</P> -<PRE> 192.168.100.0/24 left subnet - | - 192.168.100.1 - North Gateway - 101.101.101.101 left - | - 101.101.101.1 left next hop - [Internet] - 202.202.202.1 right next hop - | - 202.202.202.202 right - South gateway - 192.168.200.1 - | - 192.168.200.0/24 right subnet</PRE> -<P>A tunnel specification such as:</P> -<PRE>conn northnet-southnet - left=101.101.101.101 - leftnexthop=101.101.101.1 - leftsubnet=192.168.100.0/24 - leftfirewall=yes - right=202.202.202.202 - rightnexthop=202.202.202.1 - rightsubnet=192.168.200.0/24 - rightfirewall=yes</PRE> - will allow machines on the two subnets to talk to each other. You might - test this by pinging from polarbear (192.168.100.7) to penguin - (192.168.200.5). -<P>However,<STRONG> this does not cover other traffic you might want to - secure</STRONG>. To handle all the possibilities, you might also want - these connection descriptions:</P> -<PRE>conn northgate-southnet - left=101.101.101.101 - leftnexthop=101.101.101.1 - right=202.202.202.202 - rightnexthop=202.202.202.1 - rightsubnet=192.168.200.0/24 - rightfirewall=yes - -conn northnet-southgate - left=101.101.101.101 - leftnexthop=101.101.101.1 - leftsubnet=192.168.100.0/24 - leftfirewall=yes - right=202.202.202.202 - rightnexthop=202.202.202.1</PRE> -<P>Without these, neither gateway can do IPsec to the remote subnet. - There is no IPsec tunnel or eroute set up for the traffic.</P> -<P>In our example, with the non-routable 192.168.* addresses used, - packets would simply be discarded. In a different configuration, with - routable addresses for the remote subnet,<STRONG> they would be sent - unencrypted</STRONG> since there would be no IPsec eroute and there - would be a normal IP route.</P> -<P>You might also want:</P> -<PRE>conn northgate-southgate - left=101.101.101.101 - leftnexthop=101.101.101.1 - right=202.202.202.202 - rightnexthop=202.202.202.1</PRE> -<P>This is required if you want the two gateways to speak IPsec to each - other.</P> -<P>This requires a lot of duplication of details. Judicious use of<VAR> - also=</VAR> and<VAR> include</VAR> can reduce this problem.</P> -<P>Note that, while FreeS/WAN supports all four tunnel types, not all - implementations do. In particular, some versions of Windows 2000 and - the freely downloadable version of PGP provide only "client" - functionality. You cannot use them as gateways with a subnet behind - them. To get that functionality, you must upgrade to Windows 2000 - server or the commercially available PGP products.</P> -<H3><A name="advroute">One tunnel plus advanced routing</A></H3> - It is also possible to use the new routing features in 2.2 and later - kernels to avoid most needs for multple tunnels. Here is one mailing - list message on the topic: -<PRE>Subject: Re: linux-ipsec: IPSec packets not entering tunnel? - Date: Mon, 20 Nov 2000 - From: Justin Guyett <jfg@sonicity.com> - -On Mon, 20 Nov 2000, Claudia Schmeing wrote: - -> Right Left -> "home" "office" -> 10.92.10.0/24 ---- 24.93.85.110 ========= 216.175.164.91 ---- 10.91.10.24/24 -> -> I've created all four tunnels, and can ping to test each of them, -> *except* homegate-officenet. - -I keep wondering why people create all four tunnels. Why not route -traffic generated from home to 10.91.10.24/24 out ipsec0 with iproute2? -And 99% of the time you don't need to access "office" directly, which -means you can eliminate all but the subnet<->subnet connection.</PRE> - and FreeS/WAN technical lead Henry Spencer's comment: -<PRE>> I keep wondering why people create all four tunnels. Why not route -> traffic generated from home to 10.91.10.24/24 out ipsec0 with iproute2? - -This is feasible, given some iproute2 attention to source addresses, but -it isn't something we've documented yet... (partly because we're still -making some attempt to support 2.0.xx kernels, which can't do this, but -mostly because we haven't caught up with it yet). - -> And 99% of the time you don't need to access "office" directly, which -> means you can eliminate all but the subnet<->subnet connection. - -Correct in principle, but people will keep trying to ping to or from the -gateways during testing, and sometimes they want to run services on the -gateway machines too.</PRE> - -<!-- Is this in the right spot in this document? --> -<H2><A name="opp.gate">An Opportunistic Gateway</A></H2> -<H3><A NAME="14_7_1">Start from full opportunism</A></H3> -<P>Full opportunism allows you to initiate and receive opportunistic - connections on your machine. The remaining instructions in this section - assume you have first set up full opportunism on your gateway using<A HREF="quickstart.html#opp.incoming"> - these instructions</A>. Both sets of instructions require mailing DNS - records to your ISP. Collect DNS records for both the gateway (above) - and the subnet nodes (below) before contacting your ISP.</P> -<H3><A NAME="14_7_2">Reverse DNS TXT records for each protected machine</A> -</H3> -<P>You need these so that your Opportunistic peers can:</P> -<UL> -<LI>discover the gateway's address, knowing only the IP address that - packets are bound for</LI> -<LI>verify that the gateway is authorised to encrypt for that endpoint</LI> -</UL> -<P>On the gateway, generate a TXT record with:</P> -<PRE> ipsec showhostkey --txt 192.0.2.11</PRE> -<P>Use your gateway address in place of 192.0.2.11.</P> -<P>You should see (keys are trimmed for clarity throughout our example):</P> -<PRE> ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/"</PRE> -<P><B>This MUST BE the same key as in your gateway's TXT record, or - nothing will work.</B></P> -<P>In a text file, make one copy of this TXT record for each subnet - node:</P> -<PRE> ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/" - - ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/" - - ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/"</PRE> -<P>Above each entry, insert a line like this:</P> -<PRE> 98.2.0.192.in-addr.arpa. IN PTR arthur.example.com.</PRE> -<P>It must include:</P> -<UL> -<LI>The subnet node's address in reverse map format. For example, - 192.0.2.120 becomes<VAR> 120.2.0.192.in-addr.arpa.</VAR>. Note the - final period.</LI> -<LI><VAR>IN PTR</VAR></LI> -<LI>The node's name, ie.<VAR> arthur.example.com.</VAR>. Note the final - period.</LI> -</UL> -<P>The result will be a file of TXT records, like this:</P> -<PRE> 98.2.0.192.in-addr.arpa. IN PTR arthur.example.com. - ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/" - - 99.2.0.192.in-addr.arpa. IN PTR ford.example.com. - ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/" - - 100.2.0.192.in-addr.arpa. IN PTR trillian.example.com. - ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/"</PRE> -<H3><A NAME="14_7_3">Publish your records</A></H3> -<P>Ask your ISP to publish all the reverse DNS records you have - collected. There may be a delay of up to 48 hours as the records - propagate.</P> -<H3><A NAME="14_7_4">...and test them</A></H3> -<P>Check a couple of records with commands like this one:</P> -<PRE> ipsec verify --host ford.example.com - ipsec verify --host trillian.example.com</PRE> -<P>The<VAR> verify</VAR> command checks for TXT records for both the - subnet host and its gateway. You should see output like:</P> -<PRE> ... - Looking for TXT in reverse map: 99.2.0.192.in-addr.arpa [OK] - ... - Looking for TXT in reverse map: 11.2.0.192.in-addr.arpa [OK] - ... - Looking for TXT in reverse map: 100.2.0.192.in-addr.arpa [OK] - ... - Looking for TXT in reverse map: 11.2.0.192.in-addr.arpa [OK] - ...</PRE> -<H3><A NAME="14_7_5">No Configuration Needed</A></H3> -<P>FreeS/WAN 2.x ships with a built-in, automatically enabled OE - connection<VAR> conn packetdefault</VAR> which applies OE, if possible, - to all outbound traffic routed through the FreeS/WAN box. The<A HREF="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5) manual</A> describes this connection in detail. While the - effect is much the same as<VAR> private-or-clear</VAR>, the - implementation is different: notably, it does not use policy groups.</P> -<P>You can create more complex OE configurations for traffic forwarded - through a FreeS/WAN box, as explained in our<A HREF="policygroups.html#policygroups"> - policy groups document</A>, or disable OE using<A HREF="policygroups.html#disable_policygroups"> - these instructions</A>.</P> -<H2><A name="extruded.config">Extruded Subnets</A></H2> -<P>What we call<A href="glossary.html#extruded"> extruded subnets</A> - are a special case of<A href="glossary.html#VPN.gloss"> VPNs</A>.</P> -<P>If your buddy has some unused IP addresses, in his subnet far off at - the other side of the Internet, he can loan them to you... provided - that the connection between you and him is fast enough to carry all the - traffic between your machines and the rest of the Internet. In effect, - he "extrudes" a part of his address space over the network to you, with - your Internet traffic appearing to originate from behind his Internet - gateway.</P> -<P>As far as the Internet is concerned, your new extruded net is behind - your buddy's gateway. You route all your packets for the Internet at - large out his gateway, and receive return packets the same way. You - route your local packets locally.</P> -<P>Suppose your friend has a.b.c.0/24 and wants to give you - a.b.c.240/28. The initial situation is:</P> -<PRE> subnet gateway Internet - a.b.c.0/24 a.b.c.1 p.q.r.s</PRE> - where anything from the Internet destined for any machine in a.b.c.0/24 - is routed via p.q.r.s and that gateway knows what to do from there. -<P>Of course it is quite normal for various smaller subnets to exist - behind your friend's gateway. For example, your friend's company might - have a.b.c.16/28=development, a.b.c.32/28=marketing and so on. The - Internet neither knows not cares about this; it just delivers packets - to the p.q.r.s and lets the gateway do whatever needs to be done from - there.</P> -<P>What we want to do is take a subnet, perhaps a.b.c.240/28, out of - your friend's physical location<EM> while still having your friend's - gateway route to it</EM>. As far as the Internet is concerned, you - remain behind that gateway.</P> -<PRE> subnet gateway Internet your gate extruded - - a.b.c.0/24 a.b.c.1 p.q.r.s d.e.f.g a.b.c.240/28 - - ========== tunnel ==========</PRE> -<P>The extruded addresses have to be a complete subnet.</P> -<P>In our example, the friend's security gateway is also his Internet - gateway, but this is not necessary. As long as all traffic from the - Internet to his addresses passes through the Internet gate, the - security gate could be a machine behind that. The IG would need to - route all traffic for the extruded subnet to the SG, and the SG could - handle the rest.</P> -<P>First, configure your subnet using the extruded addresses. Your - security gateway's interface to your subnet needs to have an extruded - address (possibly using a Linux<A href="glossary.html#virtual"> virtual - interface</A>, if it also has to have a different address). Your - gateway needs to have a route to the extruded subnet, pointing to that - interface. The other machines at your site need to have addresses in - that subnet, and default routes pointing to your gateway.</P> -<P>If any of your friend's machines need to talk to the extruded subnet,<EM> - they</EM> need to have a route for the extruded subnet, pointing at his - gateway.</P> -<P>Then set up an IPsec subnet-to-subnet tunnel between your gateway and - his, with your subnet specified as the extruded subnet, and his subnet - specified as "0.0.0.0/0".</P> -<P>The tunnel description should be:</P> -<PRE>conn extruded - left=p.q.r.s - leftsubnet=0.0.0.0/0 - right=d.e.f.g - rightsubnet=a.b.c.0/28</PRE> -<P>If either side was doing firewalling for the extruded subnet before - the IPsec connection is set up, you'll need to poke holes in your<A HREF="firewall.html#firewall"> - firewall</A> to allow packets through.</P> -<P>And it all just works. Your SG routes traffic for 0.0.0.0/0 -- that - is, the whole Internet -- through the tunnel to his SG, which then - sends it onward as if it came from his subnet. When traffic for the - extruded subnet arrives at his SG, it gets sent through the tunnel to - your SG, which passes it to the right machine.</P> -<P>Remember that when ipsec_manual or ipsec_auto takes a connection - down, it<EM> does not undo the route</EM> it made for that connection. - This lets you take a connection down and bring up a new one, or a - modified version of the old one, without having to rebuild the route it - uses and without any risk of packets which should use IPsec - accidentally going out in the clear. Because the route always points - into KLIPS, the packets will always go there. Because KLIPS temporarily - has no idea what to do with them (no eroute for them), they will be - discarded.</P> -<P>If you<EM> do</EM> want to take the route down, this is what the - "unroute" operation in manual and auto is for. Just do an unroute after - doing the down.</P> -<P>Note that the route for a connection may have replaced an existing - non-IPsec route. Nothing in Linux FreeS/WAN will put that pre-IPsec - route back. If you need it back, you have to create it with the route - command.</P> -<H2><A name="roadvirt">Road Warrior with virtual IP address</A></H2> -<P>Please note that<A HREF="http://www.freeswan.ca/download.php"> Super - FreeS/WAN</A> now features DHCP-over-IPsec, which is an alternate - procedure for Virtual IP address assignment.</P> -<P></P> -<P>Here is a mailing list message about another way to configure for - road warrior support:</P> -<PRE>Subject: Re: linux-ipsec: understanding the vpn - Date: Thu, 28 Oct 1999 10:43:22 -0400 - From: Irving Reid <irving@nevex.com> - -> local-------linux------internet------mobile -> LAN box user -> ... - -> now when the mobile user connects to the linux box -> it is given a virtual IP address, i have configured it to -> be in the 10.x.x.x range. mobile user and linux box -> have a tunnel between them with these IP addresses. - -> Uptil this all is fine. - -If it is possible to configure your mobile client software *not* to -use a virtual IP address, that will make your life easier. It is easier -to configure FreeS/WAN to use the actual address the mobile user gets -from its ISP. - -Unfortunately, some Windows clients don't let you choose. - -> what i would like to know is that how does the mobile -> user communicate with other computers on the local -> LAN , of course with the vpn ? - -> what IP address should the local LAN -> computers have ? I guess their default gateway -> should be the linux box ? and does the linux box need -> to be a 2 NIC card box or one is fine. - -As someone else stated, yes, the Linux box would usually be the default -IP gateway for the local lan. - -However... - -If you mobile user has software that *must* use a virtual IP address, -the whole picture changes. Nobody has put much effort into getting -FreeS/WAN to play well in this environment, but here's a sketch of one -approach: - -Local Lan 1.0.0.0/24 - | - +- Linux FreeS/WAN 1.0.0.2 - | - | 1.0.0.1 - Router - | 2.0.0.1 - | -Internet - | - | 3.0.0.1 -Mobile User - Virtual Address: 1.0.0.3 - -Note that the Local Lan network (1.0.0.x) can be registered, routable -addresses. - -Now, the Mobile User sets up an IPSec security association with the -Linux box (1.0.0.2); it should ESP encapsulate all traffic to the -network 1.0.0.x **EXCEPT** UDP port 500. 500/udp is required for the key -negotiation, which needs to work outside of the IPSec tunnel. - -On the Linux side, there's a bunch of stuff you need to do by hand (for -now). FreeS/WAN should correctly handle setting up the IPSec SA and -routes, but I haven't tested it so this may not work... - -The FreeS/WAN conn should look like: - -conn mobile - right=1.0.0.2 - rightsubnet=1.0.0.0/24 - rightnexthop=1.0.0.1 - left=0.0.0.0 # The infamous "road warrior" - leftsubnet=1.0.0.3/32 - -Note that the left subnet contains *only* the remote host's virtual -address. - -Hopefully the routing table on the FreeS/WAN box ends up looking like -this: - -% netstat -rn -Kernel IP routing table -Destination Gateway Genmask Flags MSS Window irtt Iface -1.0.0.0 0.0.0.0 255.255.255.0 U 1500 0 0 eth0 -127.0.0.0 0.0.0.0 255.0.0.0 U 3584 0 0 lo -0.0.0.0 1.0.0.1 0.0.0.0 UG 1500 0 0 eth0 -1.0.0.3 1.0.0.1 255.255.255.255 UG 1433 0 0 ipsec0 - -So, if anybody sends a packet for 1.0.0.3 to the Linux box, it should -get bundled up and sent through the tunnel. To get the packets for -1.0.0.3 to the Linux box in the first place, you need to use "proxy -ARP". - -How this works is: when a host or router on the local Ethernet segment -wants to send a packet to 1.0.0.3, it sends out an Ethernet level -broadcast "ARP request". If 1.0.0.3 was on the local LAN, it would -reply, saying "send IP packets for 1.0.0.3 to my Ethernet address". - -Instead, you need to set up the Linux box so that _it_ answers ARP -requests for 1.0.0.3, even though that isn't its IP address. That -convinces everyone else on the lan to send 1.0.0.3 packets to the Linux -box, where the usual FreeS/WAN processing and routing take over. - -% arp -i eth0 -s 1.0.0.3 -D eth0 pub - -This says, if you see an ARP request on interface eth0 asking for -1.0.0.3, respond with the Ethernet address of interface eth0. - -Now, as I said at the very beginning, if it is *at all* possible to -configure your client *not* to use the virtual IP address, you can avoid -this whole mess.</PRE> -<H2><A name="dynamic">Dynamic Network Interfaces</A></H2> -<P>Sometimes you have to cope with a situation where the network - interface(s) aren't all there at boot. The common example is notebooks - with PCMCIA.</P> -<H3><A name="basicdyn">Basics</A></H3> -<P>The key issue here is that the<VAR> config setup</VAR> section of the<VAR> - /etc/ipsec.conf</VAR> configuration file lists the connection between - ipsecN and hardware interfaces, in the<VAR> interfaces=</VAR> variable. - At any time when<VAR> ipsec setup start</VAR> or<VAR> ipsec setup - restart</VAR> is run this variable<STRONG> must</STRONG> correspond to - the current real situation. More precisely, it<STRONG> must not</STRONG> - mention any hardware interfaces which don't currently exist. The - difficulty is that an<VAR> ipsec setup start</VAR> command is normally - run at boot time so interfaces that are not up then are mis-handled.</P> -<H3><A name="bootdyn">Boot Time</A></H3> -<P>Normally, an<VAR> ipsec setup start</VAR> is run at boot time. - However, if the hardware situation at boot time is uncertain, one of - two things must be done.</P> -<UL> -<LI>One possibility is simply not to have IPsec brought up at boot time. - To do this: -<PRE> chkconfig --level 2345 ipsec off</PRE> - That's for modern Red Hats or other Linuxes with chkconfig. Systems - which lack this will require fiddling with symlinks in /etc/rc.d/rc?.d - or the equivalent.</LI> -<LI>Another possibility is to bring IPsec up with no interfaces, which - is less aesthetically satisfying but simpler. Just put -<PRE> interfaces=</PRE> - in the configuration file. KLIPS and Pluto will be started, but won't - do anything.</LI> -</UL> -<H3><A name="changedyn">Change Time</A></H3> -<P>When the hardware *is* in place, IPsec has to be made aware of it. - Someday there may be a nice way to do this.</P> -<P>Right now, the way to do it is to fix the<VAR> /etc/ipsec.conf</VAR> - file appropriately, so<VAR> interfaces</VAR> reflects the new - situation, and then restart the IPsec subsystem. This does break any - existing IPsec connections.</P> -<P>If IPsec wasn't brought up at boot time, do</P> -<PRE> ipsec setup start</PRE> - while if it was, do -<PRE> ipsec setup restart</PRE> - which won't be as quick. -<P>If some of the hardware is to be taken out, before doing that, amend - the configuration file so interfaces no longer includes it, and do</P> -<PRE> ipsec setup restart</PRE> -<P>Again, this breaks any existing connections.</P> -<H2><A name="unencrypted">Unencrypted tunnels</A></H2> -<P>Sometimes you might want to create a tunnel without encryption. Often - this is a bad idea, even if you have some data which need not be - private. See this<A href="ipsec.html#traffic.resist"> discussion</A>.</P> -<P>The IPsec protocols provide two ways to do build such tunnels:</P> -<DL> -<DT>using ESP with null encryption</DT> -<DD>not supported by FreeS/WAN</DD> -<DT>using<A href="glossary.html#AH"> AH</A> without<A href="glossary.html#ESP"> - ESP</A></DT> -<DD>supported for manually keyed connections</DD> -<DD>possible with explicit commands via<A href="manpage.d/ipsec_whack.8.html"> - ipsec_whack(8)</A> (see this<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00190.html"> - list message</A>)</DD> -<DD>not supported in the<A href="manpage.d/ipsec_auto.8.html"> - ipsec_auto(8)</A> scripts.</DD> -</DL> - One situation in which this comes up is when otherwise some data would - be encrypted twice. Alice wants a secure tunnel from her machine to - Bob's. Since she's behind one security gateway and he's behind another, - part of the tunnel that they build passes through the tunnel that their - site admins have built between the gateways. All of Alice and Bob's - messages are encrypted twice. -<P>There are several ways to handle this.</P> -<UL> -<LI>Just accept the overhead of double encryption. The site admins might - choose this if any of the following apply: -<UL> -<LI>policy says encrypt everything (usually, it should)</LI> -<LI>they don't entirely trust Alice and Bob (usually, if they don't have - to, they shouldn't)</LI> -<LI>if they don't feel the saved cycles are worth the time they'd need - to build a non-encrypted tunnel for Alice and Bob's packets (often, - they aren't)</LI> -</UL> -</LI> -<LI>Use a plain IP-in-IP tunnel. These are not well documented. A good - starting point is in the Linux kernel source tree, in - /usr/src/linux/drivers/net/README.tunnel.</LI> -<LI>Use a manually-keyed AH-only tunnel.</LI> -</UL> -<P>Note that if Alice and Bob want end-to-end security, they must build - a tunnel end-to-end between their machines or use some other end-to-end - tool such as PGP or SSL that suits their data. The only question is - whether the admins build some special unencrypted tunnel for those - already-encrypted packets.</P> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="kernel.html">Previous</A> -<A HREF="install.html">Next</A> -</BODY> -</HTML> diff --git a/doc/background.html b/doc/background.html deleted file mode 100644 index 8f24cad4a..000000000 --- a/doc/background.html +++ /dev/null @@ -1,323 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="config.html">Previous</A> -<A HREF="user_examples.html">Next</A> -<HR> -<H1><A name="background">Linux FreeS/WAN background</A></H1> -<P>This section discusses a number of issues which have three things in - common:</P> -<UL> -<LI>They are not specifically FreeS/WAN problems</LI> -<LI>You may have to understand them to get FreeS/WAN working right</LI> -<LI>They are not simple questions</LI> -</UL> -<P>Grouping them here lets us provide the explanations some users will - need without unduly complicating the main text.</P> -<P>The explanations here are intended to be adequate for FreeS/WAN - purposes (please comment to the<A href="mail.html"> users mailing list</A> - if you don't find them so), but they are not trying to be complete or - definitive. If you need more information, see the references provided - in each section.</P> -<H2><A name="dns.background">Some DNS background</A></H2> -<P><A href="glossary.html#carpediem">Opportunistic encryption</A> - requires that the gateway systems be able to fetch public keys, and - other IPsec-related information, from each other's DNS (Domain Name - Service) records.</P> -<P><A href="glossary.html#DNS">DNS</A> is a distributed database that - maps names to IP addresses and vice versa.</P> -<P>Much good reference material is available for DNS, including:</P> -<UL> -<LI>the<A href="http://www.linuxdoc.org/HOWTO/DNS-HOWTO.html"> DNS HowTo</A> -</LI> -<LI>the standard<A href="biblio.html#DNS.book"> DNS reference</A> book</LI> -<LI><A href="http://www.linuxdoc.org/LDP/nag2/index.html">Linux Network - Administrator's Guide</A></LI> -<LI><A href="http://www.nominum.com/resources/whitepapers/bind-white-paper.html"> -BIND overview</A></LI> -<LI><A href="http://www.nominum.com/resources/documentation/Bv9ARM.pdf"> -BIND 9 Administrator's Reference</A></LI> -</UL> -<P>We give only a brief overview here, intended to help you use DNS for - FreeS/WAN purposes.</P> -<H3><A name="forward.reverse">Forward and reverse maps</A></H3> -<P>Although the implementation is distributed, it is often useful to - speak of DNS as if it were just two enormous tables:</P> -<UL> -<LI>the forward map: look up a name, get an IP address</LI> -<LI>the reverse map: look up an IP address, get a name</LI> -</UL> -<P>Both maps can optionally contain additional data. For opportunistic - encryption, we insert the data need for IPsec authentication.</P> -<P>A system named gateway.example.com with IP address 10.20.30.40 should - have at least two DNS records, one in each map:</P> -<DL> -<DT>gateway.example.com. IN A 10.20.30.40</DT> -<DD>used to look up the name and get an IP address</DD> -<DT>40.30.20.10.in-addr.arpa. IN PTR gateway.example.com.</DT> -<DD>used for reverse lookups, looking up an address to get the - associated name. Notice that the digits here are in reverse order; the - actual address is 10.20.30.40 but we use 40.30.20.10 here.</DD> -</DL> -<H3><A NAME="17_1_2">Hierarchy and delegation</A></H3> -<P>For both maps there is a hierarchy of DNS servers and a system of - delegating authority so that, for example:</P> -<UL> -<LI>the DNS administrator for example.com can create entries of the form<VAR> - name</VAR>.example.com</LI> -<LI>the example.com admin cannot create an entry for counterexample.com; - only someone with authority for .com can do that</LI> -<LI>an admin might have authority for 20.10.in-addr.arpa.</LI> -<LI>in either map, authority can be delegated -<UL> -<LI>the example.com admin could give you authority for - westcoast.example.com</LI> -<LI>the 20.10.in-addr.arpa admin could give you authority for - 30.20.10.in-addr.arpa</LI> -</UL> -</LI> -</UL> -<P>DNS zones are the units of delegation. There is a hierarchy of zones.</P> -<H3><A NAME="17_1_3">Syntax of DNS records</A></H3> -<P>Returning to the example records:</P> -<PRE> gateway.example.com. IN A 10.20.30.40 - 40.30.20.10.in-addr.arpa. IN PTR gateway.example.com.</PRE> -<P>some syntactic details are:</P> -<UL> -<LI>the IN indicates that these records are for<STRONG> In</STRONG> -ternet addresses</LI> -<LI>The final periods in '.com.' and '.arpa.' are required. They - indicate the root of the domain name system.</LI> -</UL> -<P>The capitalised strings after IN indicate the type of record. - Possible types include:</P> -<UL> -<LI><STRONG>A</STRONG>ddress, for forward lookups</LI> -<LI><STRONG>P</STRONG>oin<STRONG>T</STRONG>e<STRONG>R</STRONG>, for - reverse lookups</LI> -<LI><STRONG>C</STRONG>anonical<STRONG> NAME</STRONG>, records to support - aliasing, multiple names for one address</LI> -<LI><STRONG>M</STRONG>ail e<STRONG>X</STRONG>change, used in mail - routing</LI> -<LI><STRONG>SIG</STRONG>nature, used in<A href="glossary.html#SDNS"> - secure DNS</A></LI> -<LI><STRONG>KEY</STRONG>, used in<A href="glossary.html#SDNS"> secure - DNS</A></LI> -<LI><STRONG>T</STRONG>e<STRONG>XT</STRONG>, a multi-purpose record type</LI> -</UL> -<P>To set up for opportunistic encryption, you add some TXT records to - your DNS data. Details are in our<A href="quickstart.html"> quickstart</A> - document.</P> -<H3><A NAME="17_1_4">Cacheing, TTL and propagation delay</A></H3> -<P>DNS information is extensively cached. With no caching, a lookup by - your system of "www.freeswan.org" might involve:</P> -<UL> -<LI>your system asks your nameserver for "www.freeswan.org"</LI> -<LI>local nameserver asks root server about ".org", gets reply</LI> -<LI>local nameserver asks .org nameserver about "freeswan.org", gets - reply</LI> -<LI>local nameserver asks freeswan.org nameserver about - "www.freeswan.org", gets reply</LI> -</UL> -<P>However, this can be a bit inefficient. For example, if you are in - the Phillipines, the closest a root server is in Japan. That might send - you to a .org server in the US, and then to freeswan.org in Holland. If - everyone did all those lookups every time they clicked on a web link, - the net would grind to a halt.</P> -<P>Nameservers therefore cache information they look up. When you click - on another link at www.freeswan.org, your local nameserver has the IP - address for that server in its cache, and no further lookups are - required.</P> -<P>Intermediate results are also cached. If you next go to - lists.freeswan.org, your nameserver can just ask the freeswan.org - nameserver for that address; it does not need to query the root or .org - nameservers because it has a cached address for the freeswan.org zone - server.</P> -<P>Of course, like any cacheing mechanism, this can create problems of - consistency. What if the administrator for freeswan.org changes the IP - address, or the authentication key, for www.freeswan.org? If you use - old information from the cache, you may get it wrong. On the other - hand, you cannot afford to look up fresh information every time. Nor - can you expect the freeswan.org server to notify you; that isn't in the - protocols.</P> -<P>The solution that is in the protocols is fairly simple. Cacheable - records are marked with Time To Live (TTL) information. When the time - expires, the caching server discards the record. The next time someone - asks for it, the server fetches a fresh copy. Of course, a server may - also discard records before their TTL expires if it is running out of - cache space.</P> -<P>This implies that there will be some delay before the new version of - a changed record propagates around the net. Until the TTLs on all - copies of the old record expire, some users will see it because that is - what is in their cache. Other users may see the new record immediately - because they don't have an old one cached.</P> -<H2><A name="MTU.trouble">Problems with packet fragmentation</A></H2> -<P>It seems, from mailing list reports, to be moderately common for - problems to crop up in which small packets pass through the IPsec - tunnels just fine but larger packets fail.</P> -<P>These problems are caused by various devices along the way - mis-handling either packet fragments or<A href="glossary.html#pathMTU"> - path MTU discovery</A>.</P> -<P>IPsec makes packets larger by adding an ESP or AH header. This can - tickle assorted bugs in fragment handling in routers and firewalls, or - in path MTU discovery mechanisms, and cause a variety of symptoms which - are both annoying and, often, quite hard to diagnose.</P> -<P>An explanation from project technical lead Henry Spencer:</P> -<PRE>The problem is IP fragmentation; more precisely, the problem is that the -second, third, etc. fragments of an IP packet are often difficult for -filtering mechanisms to classify. - -Routers cannot rely on reassembling the packet, or remembering what was in -earlier fragments, because the fragments may be out of order or may even -follow different routes. So any general, worst-case filtering decision -pretty much has to be made on each fragment independently. (If the router -knows that it is the only route to the destination, so all fragments -*must* pass through it, reassembly would be possible... but most routers -don't want to bother with the complications of that.) - -All fragments carry roughly the original IP header, but any higher-level -header is (for IP purposes) just the first part of the packet data... so -only the first fragment carries that. So, for example, on examining the -second fragment of a TCP packet, you could tell that it's TCP, but not -what port number it is destined for -- that information is in the TCP -header, which appears in the first fragment only. - -The result of this classification difficulty is that stupid routers and -over-paranoid firewalls may just throw fragments away. To get through -them, you must reduce your MTU enough that fragmentation will not occur. -(In some cases, they might be willing to attempt reassembly, but have very -limited resources to devote to it, meaning that packets must be small and -fragments few in number, leading to the same conclusion: smaller MTU.)</PRE> -<P>In addition to the problem Henry describes, you may also have trouble - with<A href="glossary.html#pathMTU"> path MTU discovery</A>.</P> -<P>By default, FreeS/WAN uses a large<A href="glossary.html#MTU"> MTU</A> - for the ipsec device. This avoids some problems, but may complicate - others. Here's an explanation from Claudia:</P> -<PRE>Here are a couple of pieces of background information. Apologies if you -have seen these already. An excerpt from one of my old posts: - - An MTU of 16260 on ipsec0 is usual. The IPSec device defaults to this - high MTU so that it does not fragment incoming packets before encryption - and encapsulation. If after IPSec processing packets are larger than 1500, - [ie. the mtu of eth0] then eth0 will fragment them. - - Adding IPSec headers adds a certain number of bytes to each packet. - The MTU of the IPSec interface refers to the maximum size of the packet - before the IPSec headers are added. In some cases, people find it helpful - to set ipsec0's MTU to 1500-(IPSec header size), which IIRC is about 1430. - - That way, the resulting encapsulated packets don't exceed 1500. On most - networks, packets less than 1500 will not need to be fragmented. - -and... (from Henry Spencer) - - The way it *ought* to work is that the MTU advertised by the ipsecN - interface should be that of the underlying hardware interface, less a - pinch for the extra headers needed. - - Unfortunately, in certain situations this breaks many applications. - There is a widespread implicit assumption that the smallest MTUs are - at the ends of paths, not in the middle, and another that MTUs are - never less than 1500. A lot of code is unprepared to handle paths - where there is an "interior minimum" in the MTU, especially when it's - less than 1500. So we advertise a big MTU and just let the resulting - big packets fragment. - -This usually works, but we do get bitten in cases where some intermediate -point can't handle all that fragmentation. We can't win on this one.</PRE> -<P>The MTU can be changed with an<VAR> overridemtu=</VAR> statement in - the<VAR> config setup</VAR> section of<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf.5</A>.</P> -<P>For a discussion of MTU issues and some possible solutions using - Linux advanced routing facilities, see the<A href="http://www.linuxguruz.org/iptables/howto/2.4routing-15.html#ss15.6"> - Linux 2.4 Advanced Routing HOWTO</A>. For a discussion of MTU and NAT - (Network Address Translation), see<A HREF="http://harlech.math.ucla.edu/services/ipsec.html"> - James Carter's MTU notes</A>.</P> -<H2><A name="nat.background">Network address translation (NAT)</A></H2> -<P><STRONG>N</STRONG>etwork<STRONG> A</STRONG>ddress<STRONG> T</STRONG> -ranslation is a service provided by some gateway machines. Calling it - NAPT (adding the word<STRONG> P</STRONG>ort) would be more precise, but - we will follow the widespread usage.</P> -<P>A gateway doing NAT rewrites the headers of packets it is forwarding, - changing one or more of:</P> -<UL> -<LI>source address</LI> -<LI>source port</LI> -<LI>destination address</LI> -<LI>destination port</LI> -</UL> -<P>On Linux 2.4, NAT services are provided by the<A href="http://netfilter.samba.org"> - netfilter(8)</A> firewall code. There are several<A href="http://netfilter.samba.org/documentation/index.html#HOWTO"> - Netfilter HowTos</A> including one on NAT.</P> -<P>For older versions of Linux, this was referred to as "IP masquerade" - and different tools were used. See this<A href="http://www.e-infomax.com/ipmasq/"> - resource page</A>.</P> -<P>Putting an IPsec gateway behind a NAT gateway is not recommended. See - our<A href="firewall.html#NAT"> firewalls document</A>.</P> -<H3><A NAME="17_3_1">NAT to non-routable addresses</A></H3> -<P>The most common application of NAT uses private<A href="glossary.html#non-routable"> - non-routable</A> addresses.</P> -<P>Often a home or small office network will have:</P> -<UL> -<LI>one connection to the Internet</LI> -<LI>one assigned publicly visible IP address</LI> -<LI>several machines that all need access to the net</LI> -</UL> -<P>Of course this poses a problem since several machines cannot use one - address. The best solution might be to obtain more addresses, but often - this is impractical or uneconomical.</P> -<P>A common solution is to have:</P> -<UL> -<LI><A href="glossary.html#non-routable">non-routable</A> addresses on - the local network</LI> -<LI>the gateway machine doing NAT</LI> -<LI>all packets going outside the LAN rewritten to have the gateway as - their source address</LI> -</UL> -<P>The client machines are set up with reserved<A href="glossary.html#non-routable"> - non-routable</A> IP addresses defined in RFC 1918. The masquerading - gateway, the machine with the actual link to the Internet, rewrites - packet headers so that all packets going onto the Internet appear to - come from one IP address, that of its Internet interface. It then gets - all the replies, does some table lookups and more header rewriting, and - delivers the replies to the appropriate client machines.</P> -<P>As far as anyone else on the Internet is concerned, the systems - behind the gateway are completely hidden. Only one machine with one IP - address is visible.</P> -<P>For IPsec on such a gateway, you can entirely ignore the NAT in:</P> -<UL> -<LI><A href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</A></LI> -<LI>firewall rules affecting your Internet-side interface</LI> -</UL> -<P>Those can be set up exactly as they would be if your gateway had no - other systems behind it.</P> -<P>You do, however, have to take account of the NAT in firewall rules - which affect packet forwarding.</P> -<H3><A NAME="17_3_2">NAT to routable addresses</A></H3> -<P>NAT to routable addresses is also possible, but is less common and - may make for rather tricky routing problems. We will not discuss it - here. See the<A href="http://netfilter.samba.org/documentation/index.html#HOWTO"> - Netfilter HowTos</A>.</P> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="config.html">Previous</A> -<A HREF="user_examples.html">Next</A> -</BODY> -</HTML> diff --git a/doc/biblio.html b/doc/biblio.html deleted file mode 100644 index d54af5cbf..000000000 --- a/doc/biblio.html +++ /dev/null @@ -1,274 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="glossary.html">Previous</A> -<A HREF="rfc.html">Next</A> -<HR> -<H1><A name="biblio">Bibliography for the Linux FreeS/WAN project</A></H1> -<P>For extensive bibliographic links, see the<A href="http://liinwww.ira.uka.de/bibliography/index.html"> - Collection of Computer Science Bibliographies</A></P> -<P>See our<A href="web.html"> web links</A> for material available - online.</P> -<HR><A name="adams"> Carlisle Adams and Steve Lloyd<CITE> Understanding - Public Key Infrastructure</CITE> -<BR></A> Macmillan 1999 ISBN 1-57870-166-x -<P>An overview, mainly concentrating on policy and strategic issues - rather than the technical details. Both authors work for<A href="glossary.html#PKI"> - PKI</A> vendor<A href="http://www.entrust.com/"> Entrust</A>.</P> -<HR><A name="DNS.book"> Albitz, Liu & Loukides<CITE> DNS & BIND</CITE> - 3rd edition -<BR></A> O'Reilly 1998 ISBN 1-56592-512-2 -<P>The standard reference on the<A href="glossary.html#DNS"> Domain Name - Service</A> and<A href="glossary.html#BIND"> Berkeley Internet Name - Daemon</A>.</P> -<HR><A name="anderson"> Ross Anderson</A>,<CITE> Security Engineering - - a Guide to Building Dependable Distributed Systems</CITE> -<BR> Wiley, 2001, ISBN 0471389226 -<P>Easily the best book for the security professional I have seen.<STRONG> - Highly recommended</STRONG>. See the<A href="http://www.cl.cam.ac.uk/~rja14/book.html"> - book web page</A>.</P> -<P>This is quite readable, but Schneier's<A href="#secrets"> Secrets and - Lies</A> might be an easier introduction.</P> -<HR><A name="puzzle"> Bamford<CITE> The Puzzle Palace, A report on NSA, - Americas's most Secret Agency</CITE> -<BR> Houghton Mifflin 1982 ISBN 0-395-31286-8</A> -<HR> Bamford<CITE> Body of Secrets</CITE> -<P>The sequel.</P> -<HR><A name="bander"> David Bander</A>,<CITE> Linux Security Toolkit</CITE> -<BR> IDG Books, 2000, ISBN: 0764546902 -<P>This book has a short section on FreeS/WAN and includes Caldera Linux - on CD.</P> -<HR><A name="CZR"> Chapman, Zwicky & Russell</A>,<CITE> Building - Internet Firewalls</CITE> -<BR> O'Reilly 1995 ISBN 1-56592-124-0 -<HR><A name="firewall.book"> Cheswick and Bellovin</A><CITE> Firewalls - and Internet Security: Repelling the Wily Hacker</CITE> -<BR> Addison-Wesley 1994 ISBN 0201633574 -<P>A fine book on firewalls in particular and security in general from - two of AT&T's system adminstrators.</P> -<P>Bellovin has also done a number of<A href="web.html#papers"> papers</A> - on IPsec and co-authored a<A href="intro.html#applied"> paper</A> on a - large FreeS/WAN application.</P> -<HR><A name="comer"> Comer<CITE> Internetworking with TCP/IP</CITE> -<BR> Prentice Hall</A> -<UL> -<LI>Vol. I: Principles, Protocols, & Architecture, 3rd Ed. 1995 - ISBN:0-13-216987-8</LI> -<LI>Vol. II: Design, Implementation, & Internals, 2nd Ed. 1994 - ISBN:0-13-125527-4</LI> -<LI>Vol. III: Client/Server Programming & Applications -<UL> -<LI>AT&T TLI Version 1994 ISBN:0-13-474230-3</LI> -<LI>BSD Socket Version 1996 ISBN:0-13-260969-X</LI> -<LI>Windows Sockets Version 1997 ISBN:0-13-848714-6</LI> -</UL> -</LI> -</UL> -<P>If you need to deal with the details of the network protocols, read - either this series or the<A href="#stevens"> Stevens and Wright</A> - series before you start reading the RFCs.</P> -<HR><A name="diffie"> Diffie and Landau</A><CITE> Privacy on the Line: - The Politics of Wiretapping and Encryption</CITE> -<BR> MIT press 1998 ISBN 0-262-04167-7 (hardcover) or 0-262-54100-9 -<BR> -<HR><A name="d_and_hark"> Doraswamy and Harkins<CITE> IP Sec: The New - Security Standard for the Internet, Intranets and Virtual Private - Networks</CITE> -<BR> Prentice Hall 1999 ISBN: 0130118982</A> -<HR><A name="EFF"> Electronic Frontier Foundation<CITE> Cracking DES: - Secrets of Encryption Research, Wiretap Politics and Chip Design</CITE> -<BR></A> O'Reilly 1998 ISBN 1-56592-520-3 -<P>To conclusively demonstrate that DES is inadequate for continued use, - the<A href="glossary.html#EFF"> EFF</A> built a machine for just over - $200,000 that breaks DES encryption in under five days on average, - under nine in the worst case.</P> -<P>The book provides details of their design and, perhaps even more - important, discusses why they felt the project was necessary. - Recommended for anyone interested in any of the three topics mentioned - in the subtitle.</P> -<P>See also the<A href="http://www.eff.org/descracker.html"> EFF page on - this project</A> and our discussion of<A href="politics.html#desnotsecure"> - DES insecurity</A>.</P> -<HR> Martin Freiss<CITE> Protecting Networks with SATAN</CITE> -<BR> O'Reilly 1998 ISBN 1-56592-425-8 -<BR> translated from a 1996 work in German -<P>SATAN is a Security Administrator's Tool for Analysing Networks. This - book is a tutorial in its use.</P> -<HR> Gaidosch and Kunzinger<CITE> A Guide to Virtual Private Networks</CITE> -<BR> Prentice Hall 1999 ISBN: 0130839647 -<HR><A name="Garfinkel"> Simson Garfinkel</A><CITE> Database Nation: the - death of privacy in the 21st century</CITE> -<BR> O'Reilly 2000 ISBN 1-56592-653-6 -<P>A thoughtful and rather scary book.</P> -<HR><A name="PGP"> Simson Garfinkel</A><CITE> PGP: Pretty Good Privacy</CITE> -<BR> O'Reilly 1995 ISBN 1-56592-098-8 -<P>An excellent introduction and user manual for the<A href="glossary.html#PGP"> - PGP</A> email-encryption package. PGP is a good package with a complex - and poorly-designed user interface. This book or one like it is a must - for anyone who has to use it at length.</P> -<P>The book covers using PGP in Unix, PC and Macintosh environments, - plus considerable background material on both the technical and - political issues around cryptography.</P> -<P>The book is now seriously out of date. It does not cover recent - developments such as commercial versions since PGP 5, the Open PGP - standard or GNU PG..</P> -<HR><A name="practical"> Garfinkel and Spafford</A><CITE> Practical Unix - Security</CITE> -<BR> O'Reilly 1996 ISBN 1-56592-148-8 -<P>A standard reference.</P> -<P>Spafford's web page has an excellent collection of<A href="http://www.cs.purdue.edu/coast/hotlist"> - crypto and security links</A>.</P> -<HR><A name="Kahn"> David Kahn</A><CITE> The Codebreakers: the - Comprehensive History of Secret Communications from Ancient Times to - the Internet</CITE> -<BR> second edition Scribner 1996 ISBN 0684831309 -<P>A history of codes and code-breaking from ancient Egypt to the 20th - century. Well-written and exhaustively researched.<STRONG> Highly - recommended</STRONG>, even though it does not have much on computer - cryptography.</P> -<HR> David Kahn<CITE> Seizing the Enigma, The Race to Break the German - U-Boat codes, 1939-1943</CITE> -<BR> Houghton Mifflin 1991 ISBN 0-395-42739-8 -<HR><A name="kirch"> Olaf Kirch</A><CITE> Linux Network Administrator's - Guide</CITE> -<BR> O'Reilly 1995 ISBN 1-56592-087-2 -<P>Now becoming somewhat dated in places, but still a good introductory - book and general reference.</P> -<HR><A name="LinVPN"> Kolesnikov and Hatch</A>,<CITE> Building Linux - Virtual Private Networks (VPNs)</CITE> -<BR> New Riders 2002 -<P>This has had a number of favorable reviews, including<A href="http://www.slashdot.org/article.pl?sid=02/02/27/0115214&mode=thread&tid=172"> - this one</A> on Slashdot. The book has a<A href="http://www.buildinglinuxvpns.net/"> - web site</A>.</P> -<HR><A name="RFCs"> Pete Loshin<CITE> Big Book of IPsec RFCs</CITE> -<BR> Morgan Kaufmann 2000 ISBN: 0-12-455839-9</A> -<HR><A name="crypto"> Steven Levy<CITE> Crypto: How the Code Rebels Beat - the Government -- Saving Privacy in the Digital Age</CITE></A> -<BR> Penguin 2001, ISBN 0-670--85950-8 -<P><STRONG>Highly recommended</STRONG>. A fine history of recent (about - 1970-2000) developments in the field, and the related political - controversies. FreeS/WAN project founder and leader John Gilmore - appears several times.</P> -<P>The book does not cover IPsec or FreeS/WAN, but this project is very - much another battle in the same war. See our discussion of the<A href="politics.html"> - politics</A>.</P> -<HR><A name="GTR"> Matyas, Anderson et al.</A><CITE> The Global Trust - Register</CITE> -<BR> Northgate Consultants Ltd 1998 ISBN: 0953239705 -<BR> hard cover edition MIT Press 1999 ISBN 0262511053 -<P>From<A href="http://www.cl.cam.ac.uk/Research/Security/Trust-Register"> - their web page:</A></P> -<BLOCKQUOTE> This book is a register of the fingerprints of the world's - most important public keys; it implements a top-level certification - authority (CA) using paper and ink rather than in an electronic system.</BLOCKQUOTE> -<HR><A name="handbook"> Menezies, van Oorschot and Vanstone<CITE> - Handbook of Applied Cryptography</CITE></A> -<BR> CRC Press 1997 -<BR> ISBN 0-8493-8523-7 -<P>An excellent reference. Read<A href="#schneier"> Schneier</A> before - tackling this.</P> -<HR> Michael Padlipsky<CITE> Elements of Networking Style</CITE> -<BR> Prentice-Hall 1985 ISBN 0-13-268111-0 or 0-13-268129-3 -<P>Probably<STRONG> the funniest technical book ever written</STRONG>, - this is a vicious but well-reasoned attack on the OSI "seven layer - model" and all that went with it. Several chapters of it are also - available as RFCs 871 to 875.</P> -<HR><A name="matrix"> John S. Quarterman</A><CITE> The Matrix: Computer - Networks and Conferencing Systems Worldwide</CITE> -<BR> Digital Press 1990 ISBN 155558-033-5 -<BR> Prentice-Hall ISBN 0-13-565607-9 -<P>The best general treatment of computer-mediated communication we have - seen. It naturally has much to say about the Internet, but also covers - UUCP, Fidonet and so on.</P> -<HR><A name="ranch"> David Ranch</A><CITE> Securing Linux Step by Step</CITE> -<BR> SANS Institute, 1999 -<P><A href="http://www.sans.org/">SANS</A> is a respected organisation, - this guide is part of a well-known series, and Ranch has previously - written the useful<A href=" http://www.ecst.csuchico.edu/~dranch/LINUX/index-linux.html#trinityos"> - Trinity OS</A> guide to securing Linux, so my guess would be this is a - pretty good book. I haven't read it yet, so I'm not certain. It can be - ordered online from<A href="http://www.sans.org/"> SANS</A>.</P> -<P>Note (Mar 1, 2002): a new edition with different editors in the - works. Expect it this year.</P> -<HR><A name="schneier"> Bruce Schneier</A><CITE> Applied Cryptography, - Second Edition</CITE> -<BR> John Wiley & Sons, 1996 -<BR> ISBN 0-471-12845-7 hardcover -<BR> ISBN 0-471-11709-9 paperback -<P>A standard reference on computer cryptography. For more recent - essays, see the<A href="http://www.counterpane.com/"> author's - company's web site</A>.</P> -<HR><A name="secrets"> Bruce Schneier</A><CITE> Secrets and Lies</CITE> -<BR> Wiley 2000, ISBN 0-471-25311-1 -<P>An interesting discussion of security and privacy issues, written - with more of an "executive overview" approach rather than a narrow - focus on the technical issues.<STRONG> Highly recommended</STRONG>.</P> -<P>This is worth reading even if you already understand security issues, - or think you do. To go deeper, follow it with Anderson's<A href="#anderson"> - Security Engineering</A>.</P> -<HR><A name="VPNbook"> Scott, Wolfe and Irwin<CITE> Virtual Private - Networks</CITE></A> -<BR> 2nd edition, O'Reilly 1999 ISBN: 1-56592-529-7 -<P>This is the only O'Reilly book, out of a dozen I own, that I'm - disappointed with. It deals mainly with building VPNs with various - proprietary tools --<A href="glossary.html#PPTP"> PPTP</A>,<A href="glossary.html#SSH"> - SSH</A>, Cisco PIX, ... -- and touches only lightly on IPsec-based - approaches.</P> -<P>That said, it appears to deal competently with what it does cover and - it has readable explanations of many basic VPN and security concepts. - It may be exactly what some readers require, even if I find the - emphasis unfortunate.</P> -<HR><A name="LASG"> Kurt Seifried<CITE> Linux Administrator's Security - Guide</CITE></A> -<P>Available online from<A href="http://www.securityportal.com/lasg/"> - Security Portal</A>. It has fairly extensive coverage of IPsec.</P> -<HR><A name="Smith"> Richard E Smith<CITE> Internet Cryptography</CITE> -<BR></A> ISBN 0-201-92480-3, Addison Wesley, 1997 -<P>See the book's<A href="http://www.visi.com/crypto/inet-crypto/index.html"> - home page</A></P> -<HR><A name="neal"> Neal Stephenson<CITE> Cryptonomicon</CITE></A> -<BR> Hardcover ISBN -380-97346-4, Avon, 1999. -<P>A novel in which cryptography and the net figure prominently.<STRONG> - Highly recommended</STRONG>: I liked it enough I immediately went out - and bought all the author's other books.</P> -<P>There is also a paperback edition. Sequels are expected.</P> -<HR><A name="stevens"> Stevens and Wright</A><CITE> TCP/IP Illustrated</CITE> -<BR> Addison-Wesley -<UL> -<LI>Vol. I: The Protocols 1994 ISBN:0-201-63346-9</LI> -<LI>Vol. II: The Implementation 1995 ISBN:0-201-63354-X</LI> -<LI>Vol. III: TCP for Transactions, HTTP, NNTP, and the UNIX Domain - Protocols 1996 ISBN: 0-201-63495-3</LI> -</UL> -<P>If you need to deal with the details of the network protocols, read - either this series or the<A href="#comer"> Comer</A> series before you - start reading the RFCs.</P> -<HR><A name="Rubini"> Rubini</A><CITE> Linux Device Drivers</CITE> -<BR> O'Reilly & Associates, Inc. 1998 ISBN 1-56592-292-1 -<HR><A name="Zeigler"> Robert Zeigler</A><CITE> Linux Firewalls</CITE> -<BR> Newriders Publishing, 2000 ISBN 0-7537-0900-9 -<P>A good book, with detailed coverage of ipchains(8) firewalls and of - many related issues.</P> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="glossary.html">Previous</A> -<A HREF="rfc.html">Next</A> -</BODY> -</HTML> diff --git a/doc/compat.html b/doc/compat.html deleted file mode 100644 index f01efa64c..000000000 --- a/doc/compat.html +++ /dev/null @@ -1,707 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="trouble.html">Previous</A> -<A HREF="interop.html">Next</A> -<HR> -<H1><A name="compat">Linux FreeS/WAN Compatibility Guide</A></H1> -<P>Much of this document is quoted directly from the Linux FreeS/WAN<A href="mail.html"> - mailing list</A>. Thanks very much to the community of testers, - patchers and commenters there, especially the ones quoted below but - also various contributors we haven't quoted.</P> -<H2><A name="spec">Implemented parts of the IPsec Specification</A></H2> -<P>In general, do not expect Linux FreeS/WAN to do everything yet. This - is a work-in-progress and some parts of the IPsec specification are not - yet implemented.</P> -<H3><A name="in">In Linux FreeS/WAN</A></H3> -<P>Things we do, as of version 1.96:</P> -<UL> -<LI>key management methods -<DL> -<DT>manually keyed</DT> -<DD>using keys stored in /etc/ipsec.conf</DD> -<DT>automatically keyed</DT> -<DD>Automatically negotiating session keys as required. All connections - are automatically re-keyed periodically. The<A href="glossary.html#Pluto"> - Pluto</A> daemon implements this using the<A href="glossary.html#IKE"> - IKE</A> protocol.</DD> -</DL> -</LI> -<LI>Methods of authenticating gateways for IKE -<DL> -<DT>shared secrets</DT> -<DD>stored in<A href="manpage.d/ipsec.secrets.5.html"> ipsec.secrets(5)</A> -</DD> -<DT><A href="glossary.html#RSA">RSA</A> signatures</DT> -<DD>For details, see<A href="manpage.d/ipsec_pluto.8.html"> pluto(8)</A> -.</DD> -<DT>looking up RSA authentication keys from<A href="glossary.html#DNS"> - DNS</A>.</DT> -<DD>Note that this technique cannot be fully secure until<A href="glossary.html#SDNS"> - secure DNS</A> is widely deployed.</DD> -</DL> -</LI> -<LI>groups for<A href="glossary.html#DH"> Diffie-Hellman</A> key - negotiation -<DL> -<DT>group 2, modp 1024-bit</DT> -<DT>group 5, modp 1536-bit</DT> -<DD>We implement these two groups. -<P>In negotiating a keying connection (ISAKMP SA, Phase 1) we propose - both groups when we are the initiator, and accept either when a peer - proposes them. Once the keying connection is made, we propose only the - alternative agreed there for data connections (IPsec SA's, Phase 2) - negotiated over that keying connection.</P> -</DD> -</DL> -</LI> -<LI>encryption transforms -<DL> -<DT><A href="glossary.html#DES">DES</A></DT> -<DD>DES is in the source code since it is needed to implement 3DES, but - single DES is not made available to users because<A href="politics.html#desnotsecure"> - DES is insecure</A>.</DD> -<DT><A href="glossary.html#3DES">Triple DES</A></DT> -<DD>implemented, and used as the default encryption in Linux FreeS/WAN.</DD> -</DL> -</LI> -<LI>authentication transforms -<DL> -<DT><A href="glossary.html#HMAC">HMAC</A> using<A href="glossary.html#MD5"> - MD5</A></DT> -<DD>implemented, may be used in IKE or by by AH or ESP transforms.</DD> -<DT><A href="glossary.html#HMAC">HMAC</A> using<A href="glossary.html#SHA"> - SHA</A></DT> -<DD>implemented, may be used in IKE or by AH or ESP transforms.</DD> -</DL> -<P>In negotiations, we propose both of these and accept either.</P> -</LI> -<LI>compression transforms -<DL> -<DT>IPComp</DT> -<DD>IPComp as described in RFC 2393 was added for FreeS/WAN 1.6. Note - that Pluto becomes confused if you ask it to do IPComp when the kernel - cannot.</DD> -</DL> -</LI> -</UL> -<P>All combinations of implemented transforms are supported. Note that - some form of packet-level<STRONG> authentication is required whenever - encryption is used</STRONG>. Without it, the encryption will not be - secure.</P> -<H3><A name="dropped">Deliberately omitted</A></H3> - We do not implement everything in the RFCs because some of those things - are insecure. See our discussions of avoiding<A href="politics.html#weak"> - bogus security</A>. -<P>Things we deliberately omit which are required in the RFCs are:</P> -<UL> -<LI>null encryption (to use ESP as an authentication-only service)</LI> -<LI>single DES</LI> -<LI>DH group 1, a 768-bit modp group</LI> -</UL> -<P>Since these are the only encryption algorithms and DH group the RFCs - require, it is possible in theory to have a standards-conforming - implementation which will not interpoperate with FreeS/WAN. Such an - implementation would be inherently insecure, so we do not consider this - a problem.</P> -<P>Anyway, most implementations sensibly include more secure options as - well, so dropping null encryption, single DES and Group 1 does not - greatly hinder interoperation in practice.</P> -<P>We also do not implement some optional features allowed by the RFCs:</P> -<UL> -<LI>aggressive mode for negotiation of the keying channel or ISAKMP SA. - This mode is a little faster than main mode, but exposes more - information to an eavesdropper.</LI> -</UL> -<P>In theory, this should cause no interoperation problems since all - implementations are required to support the more secure main mode, - whether or not they also allow aggressive mode.</P> -<P>In practice, it does sometimes produce problems with implementations - such as Windows 2000 where aggressive mode is the default. Typically, - these are easily solved with a configuration change that overrides that - default.</P> -<H3><A name="not">Not (yet) in Linux FreeS/WAN</A></H3> -<P>Things we don't yet do, as of version 1.96:</P> -<UL> -<LI>key management methods -<UL> -<LI>authenticate key negotiations via local<A href="glossary.html#PKI"> - PKI</A> server, but see links to user<A href="web.html#patch"> patches</A> -</LI> -<LI>authenticate key negotiations via<A href="glossary.html#SDNS"> - secure DNS</A></LI> -<LI>unauthenticated key management, using<A href="glossary.html#DH"> - Diffie-Hellman</A> key agreement protocol without authentication. - Arguably, this would be worth doing since it is secure against all - passive attacks. On the other hand, it is vulnerable to an active<A href="glossary.html#middle"> - man-in-the-middle attack</A>.</LI> -</UL> -</LI> -<LI>encryption transforms -<P>Currently<A href="glossary.html#3DES"> Triple DES</A> is the only - encryption method Pluto will negotiate.</P> -<P>No additional encryption transforms are implemented, though the RFCs - allow them and some other IPsec implementations support various of - them. We are not eager to add more. See this<A href="faq.html#other.cipher"> - FAQ question</A>.</P> -<P><A href="glossary.html#AES">AES</A>, the successor to the DES - standard, is an excellent candidate for inclusion in FreeS/WAN, see - links to user<A href="web.html#patch"> patches</A>.</P> -</LI> -<LI>authentication transforms -<P>No optional additional authentication transforms are currently - implemented. Likely<A href="glossary.html#SHA-256"> SHA-256, SHA-384 - and SHA-512</A> will be added when AES is.</P> -</LI> -<LI>Policy checking on decrypted packets -<P>To fully comply with the RFCs, it is not enough just to accept only - packets which survive any firewall rules in place to limit what IPsec - packets get in, and then pass KLIPS authentication. That is what - FreeS/WAN currently does.</P> -<P>We should also apply additional tests, for example ensuring that all - packets emerging from a particular tunnel have source and destination - addresses that fall within the subnets defined for that tunnel, and - that packets with those addresses that did not emerge from the - appropriate tunnel are disallowed.</P> -<P>This will be done as part of a KLIPS rewrite. See these<A href="intro.html#applied"> - links</A> and the<A href="mail.html"> design mailing list</A> for - discussion.</P> -</LI> -</UL> -<H2><A name="pfkey">Our PF-Key implementation</A></H2> -<P>We use PF-key Version Two for communication between the KLIPS kernel - code and the Pluto Daemon. PF-Key v2 is defined by<A href="http://www.normos.org/ietf/rfc/rfc2367.txt"> - RFC 2367</A>.</P> -<P>The "PF" stands for Protocol Family. PF-Inet defines a - kernel/userspace interface for the TCP/IP Internet protocols (TCP/IP), - and other members of the PF series handle Netware, Appletalk, etc. - PF-Key is just a PF for key-related matters.</P> -<H3><A name="pfk.port">PF-Key portability</A></H3> -<P>PF-Key came out of Berkeley Unix work and is used in the various BSD - IPsec implementations, and in Solaris. This means there is some hope of - porting our Pluto(8) to one of the BSD distributions, or of running - their photurisd(8) on Linux if you prefer<A href="glossary.html#photuris"> - Photuris</A> key management over IKE.</P> -<P>It is, however, more complex than that. The PK-Key RFC deliberately - deals only with keying, not policy management. The three PF-Key - implementations we have looked at -- ours, OpenBSD and KAME -- all have - extensions to deal with security policy, and the extensions are - different. There have been discussions aimed at sorting out the - differences, perhaps for a version three PF-Key spec. All players are - in favour of this, but everyone involved is busy and it is not clear - whether or when these discussions might bear fruit.</P> -<H2><A name="otherk">Kernels other than the latest 2.2.x and 2.4.y</A></H2> -<P>We develop and test on Redhat Linux using the most recent kernel in - the 2.2 and 2.4 series. In general, we recommend you use the latest - kernel in one of those series. Complications and caveats are discussed - below.</P> -<H3><A name="kernel.2.0">2.0.x kernels</A></H3> -<P>Consider upgrading to the 2.2 kernel series. If you want to stay with - the 2.0 series, then we strongly recommend 2.0.39. Some useful security - patches were added in 2.0.38.</P> -<P>Various versions of the code have run at various times on most 2.0.xx - kernels, but the current version is only lightly tested on 2.0.39, and - not at all on older kernels.</P> -<P>Some of our patches for older kernels are shipped in 2.0.37 and - later, so they are no longer provided in FreeS/WAN. This means recent - versions of FreeS/WAN will probably not compile on anything earlier - than 2.0.37.</P> -<H3><A name="kernel.production">2.2 and 2.4 kernels</A></H3> -<DL> -<DT>FreeS/WAN 1.0</DT> -<DD>ran only on 2.0 kernels</DD> -<DT>FreeS/WAN 1.1 to 1.8</DT> -<DD>ran on 2.0 or 2.2 kernels -<BR> ran on some development kernels, 2.3 or 2.4-test</DD> -<DT>FreeS/WAN 1.9 to 1.96</DT> -<DD>runs on 2.0, 2.2 or 2.4 kernels</DD> -</DL> -<P>In general,<STRONG> we suggest the latest 2.2 kernel or 2.4 for - production use</STRONG>.</P> -<P>Of course no release can be guaranteed to run on kernels more recent - than it is, so quite often there will be no stable FreeS/WAN for the - absolute latest kernel. See the<A href="faq.html#k.versions"> FAQ</A> - for discussion.</P> -<H2><A name="otherdist">Intel Linux distributions other than Redhat</A></H2> -<P>We develop and test on Redhat 6.1 for 2.2 kernels, and on Redhat 7.1 - or 7.2 for 2.4, so minor changes may be required for other - distributions.</P> -<H3><A name="rh7">Redhat 7.0</A></H3> -<P>There are some problems with FreeS/WAN on Redhat 7.0. They are - soluble, but we recommend you upgrade to a later Redhat instead..</P> -<P>Redhat 7 ships with two compilers.</P> -<UL> -<LI>Their<VAR> gcc</VAR> is version 2.96. Various people, including the - GNU compiler developers and Linus, have said fairly emphatically that - using this was a mistake. 2.96 is a development version, not intended - for production use. In particular, it will not compile a Linux kernel.</LI> -<LI>Redhat therefore also ship a separate compiler, which they call<VAR> - kgcc</VAR>, for compiling kernels.</LI> -</UL> -<P>Kernel Makefiles have<VAR> gcc</VAR> as a default, and must be - adjusted to use<VAR> kgcc</VAR> before a kernel will compile on 7.0. - This mailing list message gives details:</P> -<PRE>Subject: Re: AW: Installing IPsec on Redhat 7.0 - Date: Thu, 1 Feb 2001 14:32:52 -0200 (BRST) - From: Mads Rasmussen <mads@cit.com.br> - -> From www.redhat.com/support/docs/gotchas/7.0/gotchas-7-6.html#ss6.1 - -cd to /usr/src/linux and open the Makefile in your favorite editor. You -will need to look for a line similar to this: - -CC = $(CROSS_COMPILE)gcc -D__KERNEL__ -I$(HPATH) - -This line specifies which C compiler to use to build the kernel. It should -be changed to: - -CC = $(CROSS_COMPILE)kgcc -D__KERNEL__ -I$(HPATH) - -for Red Hat Linux 7. The kgcc compiler is egcs 2.91.66. From here you can -proceed with the typical compiling steps.</PRE> -<P>Check the<A href="mail.html"> mailing list</A> archive for more - recent news.</P> -<H3><A name="suse">SuSE Linux</A></H3> -<P>SuSE 6.3 and later versions, at least in Europe, ship with FreeS/WAN - included.</P> -<P>FreeS/WAN packages distributed for SuSE 7.0-7.2 were somehow - miscompiled. You can find fixed packages on<A HREF="http://www.suse.de/~garloff/linux/FreeSWAN"> - Kurt Garloff's page</A>.</P> -<P>Here are some notes for an earlier SuSE version.</P> -<H4>SuSE Linux 5.3</H4> -<PRE>Date: Mon, 30 Nov 1998 -From: Peter Onion <ponion@srd.bt.co.uk> - -... I got Saturdays snapshot working between my two SUSE5.3 machines at home. - -The mods to the install process are quite simple. From memory and looking at -the files on the SUSE53 machine here at work.... - -And extra link in each of the /etc/init.d/rc?.d directories called K35ipsec -which SUSE use to shut a service down. - -A few mods in /etc/init.d/ipsec to cope with the different places that SUSE -put config info, and remove the inculsion of /etc/rc.d/init.d/functions and . -/etc/sysconfig/network as they don't exists and 1st one isn't needed anyway. - -insert ". /etc/rc.config" to pick up the SUSE config info and use - - if test -n "$NETCONFIG" -a "$NETCONFIG" != "YAST_ASK" ; then - -to replace - - [ ${NETWORKING} = "no" ] && exit 0 - -Create /etc/sysconfig as SUSE doesn't have one. - -I think that was all (but I prob forgot something)....</PRE> -<P>You may also need to fiddle initialisation scripts to ensure that<VAR> - /var/run/pluto.pid</VAR> is removed when rebooting. If this file is - present, Pluto does not come up correctly.</P> -<H3><A name="slack">Slackware</A></H3> -<PRE>Subject: Re: linux-IPsec: Slackware distribution - Date: Thu, 15 Apr 1999 12:07:01 -0700 - From: Evan Brewer <dmessiah@silcon.com> - -> Very shortly, I will be needing to install IPsec on at least gateways that -> are running Slackware. . . . - -The only trick to getting it up is that on the slackware dist there is no -init.d directory in /etc/rc.d .. so create one. Then, what I do is take the -IPsec startup script which normally gets put into the init.d directory, and -put it in /etc/rc.d and name ir rc.ipsec .. then I symlink it to the file -in init.d. The only file in the dist you need to really edit is the -utils/Makefile, setup4: - -Everything else should be just fine.</PRE> -<P>A year or so later:</P> -<PRE>Subject: Re: HTML Docs- Need some cleanup? - Date: Mon, 8 Jan 2001 - From: Jody McIntyre <jodym@oeone.com> - -I have successfully installed FreeS/WAN on several Slackware 7.1 machines. -FreeS/WAN installed its rc.ipsec file in /etc/rc.d. I had to manually call -this script from rc.inet2. This seems to be an easier method than Evan -Brewer's.</PRE> -<H3><A name="deb">Debian</A></H3> -<P>A recent (Nov 2001) mailing list points to a<A href="http://www.thing.dyndns.org/debian/vpn.htm"> - web page</A> on setting up several types of tunnel, including IPsec, on - Debian.</P> -<P>Some older information:</P> -<PRE>Subject: FreeS/WAN 1.0 on Debian 2.1 - Date: Tue, 20 Apr 1999 - From: Tim Miller <cerebus+counterpane@haybaler.sackheads.org> - - Compiled and installed without error on a Debian 2.1 system -with kernel-source-2.0.36 after pointing RCDIR in utils/Makefile to -/etc/init.d. - - /var/lock/subsys/ doesn't exist on Debian boxen, needs to be -created; not a fatal error. - - Finally, IPsec scripts appear to be dependant on GNU awk -(gawk); the default Debian awk (mawk-1.3.3-2) had fatal difficulties. -With gawk installed and /etc/alternatives/awk linked to /usr/bin/gawk -operation appears flawless.</PRE> -<P>The scripts in question have been modified since this was posted. Awk - versions should no longer be a problem.</P> -<H3><A name="caldera">Caldera</A></H3> -<PRE>Subject: Re: HTML Docs- Need some cleanup? - Date: Mon, 08 Jan 2001 - From: Andy Bradford <andyb@calderasystems.com> - -On Sun, 07 Jan 2001 22:59:05 EST, Sandy Harris wrote: - -> Intel Linux distributions other than Redhat 5.x and 6.x -> Redhat 7.0 -> SuSE Linux -> SuSE Linux 5.3 -> Slackware -> Debian - -Can you please include Caldera in this list? I have tested it since -FreeS/Wan 1.1 and it works great with our systems---provided one -follows the FreeS/Wan documentation. :-) - -Thank you, -Andy</PRE> -<H2><A name="CPUs">CPUs other than Intel</A></H2> -<P>FreeS/WAN has been run sucessfully on a number of different CPU - architectures. If you have tried it on one not listed here, please post - to the<A href="mail.html"> mailing list</A>.</P> -<H3><A name=" strongarm">Corel Netwinder (StrongARM CPU)</A></H3> -<PRE>Subject: linux-ipsec: Netwinder diffs -Date: Wed, 06 Jan 1999 -From: rhatfield@plaintree.com - -I had a mistake in my IPsec-auto, so I got things working this morning. - -Following are the diffs for my changes. Probably not the best and cleanest way -of doing it, but it works. . . . </PRE> -<P>These diffs are in the 0.92 and later distributions, so these should - work out-of-the-box on Netwinder.</P> -<H3><A name="yellowdog">Yellow Dog Linux on Power PC</A></H3> -<PRE>Subject: Compiling FreeS/WAN 1.1 on YellowDog Linux (PPC) - Date: 11 Dec 1999 - From: Darron Froese <darron@fudgehead.com> - -I'm summarizing here for the record - because it's taken me many hours to do -this (multiple times) and because I want to see IPsec on more linuxes than -just x86. - -Also, I can't remember if I actually did summarize it before... ;-) I'm -working too many late hours. - -That said - here goes. - -1. Get your linux kernel and unpack into /usr/src/linux/ - I used 2.2.13. -<http://www.kernel.org/pub/linux/kernel/v2.2/linux-2.2.13.tar.bz2> - -2. Get FreeS/WAN and unpack into /usr/src/freeswan-1.1 -<ftp://ftp.xs4all.nl/pub/crypto/freeswan/freeswan-1.1.tar.gz> - -3. Get the gmp src rpm from here: -<ftp://ftp.yellowdoglinux.com//pub/yellowdog/champion-1.1/SRPMS/SRPMS/gmp-2.0.2-9a.src.rpm> - -4. Su to root and do this: rpm --rebuild gmp-2.0.2-9a.src.rpm - -You will see a lot of text fly by and when you start to see the rpm -recompiling like this: - -Executing: %build -+ umask 022 -+ cd /usr/src/redhat/BUILD -+ cd gmp-2.0.2 -+ libtoolize --copy --force -Remember to add `AM_PROG_LIBTOOL' to `configure.in'. -You should add the contents of `/usr/share/aclocal/libtool.m4' to -`aclocal.m4'. -+ CFLAGS=-O2 -fsigned-char -+ ./configure --prefix=/usr - -Hit Control-C to stop the rebuild. NOTE: We're doing this because for some -reason the gmp source provided with FreeS/WAN 1.1 won't build properly on -ydl. - -cd /usr/src/redhat/BUILD/ -cp -ar gmp-2.0.2 /usr/src/freeswan-1.1/ -cd /usr/src/freeswan-1.1/ -rm -rf gmp -mv gmp-2.0.2 gmp - -5. Open the freeswan Makefile and change the line that says: -KERNEL=$(b)zimage (or something like that) to -KERNEL=vmlinux - -6. cd ../linux/ - -7. make menuconfig -Select an option or two and then exit - saving your changes. - -8. cd ../freeswan-1.1/ ; make menugo - -That will start the whole process going - once that's finished compiling, -you have to install your new kernel and reboot. - -That should build FreeS/WAN on ydl (I tried it on 1.1).</PRE> - And a later message on the same topic: -<PRE>Subject: Re: FreeS/WAN, PGPnet and E-mail - Date: Sat, 22 Jan 2000 - From: Darron Froese <darron@fudgehead.com> - -on 1/22/00 6:47 PM, Philip Trauring at philip@trauring.com wrote: - -> I have a PowerMac G3 ... - -The PowerMac G3 can run YDL 1.1 just fine. It should also be able to run -FreeS/WAN 1.2patch1 with a couple minor modifications: - -1. In the Makefile it specifies a bzimage for the kernel compile - you have -to change that to vmlinux for the PPC. - -2. The gmp source that comes with FreeS/WAN (for whatever reason) fails to -compile. I have gotten around this by getting the gmp src rpm from here: - -ftp://ftp.yellowdoglinux.com//pub/yellowdog/champion-1.1/SRPMS/SRPMS/gmp-2.0.2-9a.src.rpm - -If you rip the source out of there - and place it where the gmp source -resides it will compile just fine.</PRE> -<P>FreeS/WAN no longer includes GMP source.</P> -<H3><A name="mklinux">Mklinux</A></H3> -<P>One user reports success on the Mach-based<STRONG> m</STRONG>icro<STRONG> -k</STRONG>ernel Linux.</P> -<PRE>Subject: Smiles on sparc and ppc - Date: Fri, 10 Mar 2000 - From: Jake Hill <jah@alien.bt.co.uk> - -You may or may not be interested to know that I have successfully built -FreeS/WAN on a number of non intel alpha architectures; namely on ppc -and sparc and also on osfmach3/ppc (MkLinux). I can report that it just -works, mostly, with few changes.</PRE> -<H3><A name="alpha">Alpha 64-bit processors</A></H3> -<PRE>Subject: IT WORKS (again) between intel & alpha :-))))) - Date: Fri, 29 Jan 1999 - From: Peter Onion <ponion@srd.bt.co.uk> - -Well I'm happy to report that I've got an IPsec connection between by intel & alpha machines again :-)) - -If you look back on this list to 7th of December I wrote... - --On 07-Dec-98 Peter Onion wrote: --> --> I've about had enuf of wandering around inside the kernel trying to find out --> just what is corrupting outgoing packets... -- --Its 7:30 in the evening ..... -- --I FIXED IT :-)))))))))))))))))))))))))))))))) -- --It was my own fault :-(((((((((((((((((( -- --If you ask me very nicly I'll tell you where I was a little too over keen to --change unsigned long int __u32 :-) OPSE ... -- --So tomorrow it will full steam ahead to produce a set of diffs/patches against --0.91 -- --Peter Onion.</PRE> -<P>In general (there have been some glitches), FreeS/WAN has been - running on Alphas since then.</P> -<H3><A name="SPARC">Sun SPARC processors</A></H3> -<P>Several users have reported success with FreeS/WAN on SPARC Linux. - Here is one mailing list message:</P> -<PRE>Subject: Smiles on sparc and ppc - Date: Fri, 10 Mar 2000 - From: Jake Hill <jah@alien.bt.co.uk> - -You may or may not be interested to know that I have successfully built -FreeS/WAN on a number of non intel alpha architectures; namely on ppc -and sparc and also on osfmach3/ppc (MkLinux). I can report that it just -works, mostly, with few changes. - -I have a question, before I make up some patches. I need to hack -gmp/mpn/powerpc32/*.s to build them. Is this ok? The changes are -trivial, but could I also use a different version of gmp? Is it vanilla -here? - -I guess my only real headache is from ipchains, which appears to stop -running when IPsec has been started for a while. This is with 2.2.14 on -sparc.</PRE> -<P>This message, from a different mailing list, may be relevant for - anyone working with FreeS/WAN on Suns:</P> -<PRE>Subject: UltraSPARC DES assembler - Date: Thu, 13 Apr 2000 - From: svolaf@inet.uni2.dk (Svend Olaf Mikkelsen) - To: coderpunks@toad.com - -An UltraSPARC assembler version of the LibDES/SSLeay/OpenSSL des_enc.c -file is available at http://inet.uni2.dk/~svolaf/des.htm. - -This brings DES on UltraSPARC from slower than Pentium at the same -clock speed to significantly faster.</PRE> -<H3><A name="mips">MIPS processors</A></H3> -<P>We know FreeS/WAN runs on at least some MIPS processors because<A href="http://www.lasat.com"> - Lasat</A> manufacture an IPsec box based on an embedded MIPS running - Linux with FreeS/WAN. We have no details.</P> -<H3><A name="crusoe">Transmeta Crusoe</A></H3> -<P>The Merilus<A href="http://www.merilus.com/products/fc/index.shtml"> - Firecard</A>, a Linux firewall on a PCI card, is based on a Crusoe - processor and supports FreeS/WAN.</P> -<H3><A name="coldfire">Motorola Coldfire</A></H3> -<PRE>Subject: Re: Crypto hardware support - Date: Mon, 03 Jul 2000 - From: Dan DeVault <devault@tampabay.rr.com> - -.... I have been running -uClinux with FreeS/WAN 1.4 on a system built by Moreton Bay ( -http://www.moretonbay.com ) and it was using a Coldfire processor -and was able to do the Triple DES encryption at just about -1 mbit / sec rate....... they put a Hi/Fn 7901 hardware encryption -chip on their board and now their system does over 25 mbit of 3DES -encryption........ pretty significant increase if you ask me.</PRE> -<H2><A name="multiprocessor">Multiprocessor machines</A></H2> -<P>FreeS/WAN is designed to work on SMP (symmetric multi-processing) - Linux machines and is regularly tested on dual processor x86 machines.</P> -<P>We do not know of any testing on multi-processor machines with other - CPU architectures or with more than two CPUs. Anyone who does test - this, please report results to the<A href="mail.html"> mailing list</A> -.</P> -<P>The current design does not make particularly efficient use of - multiprocessor machines; some of the kernel work is single-threaded.</P> -<H2><A name="hardware">Support for crypto hardware</A></H2> -<P>Supporting hardware cryptography accelerators has not been a high - priority for the development team because it raises a number of fairly - complex issues:</P> -<UL> -<LI>Can you trust the hardware? If it is not Open Source, how do you - audit its security? Even if it is, how do you check that the design has - no concealed traps?</LI> -<LI>If an interface is added for such hardware, can that interface be - subverted or misused?</LI> -<LI>Is hardware acceleration actually a performance win? It clearly is - in many cases, but on a fast machine it might be better to use the CPU - for the encryption than to pay the overheads of moving data to and from - a crypto board.</LI> -<LI>the current KLIPS code does not provide a clean interface for - hardware accelerators</LI> -</UL> -<P>That said, we have a<A href="#coldfire"> report</A> of FreeS/WAN - working with one crypto accelerator and some work is going on to modify - KLIPS to create a clean generic interface to such products. See this<A href="http://www.jukie.net/~bart/linux-ipsec/"> - web page</A> for some of the design discussion.</P> -<P>More recently, a patch to support some hardware accelerators has been - posted:</P> -<PRE>Subject: [Design] [PATCH] H/W acceleration patch - Date: Tue, 18 Sep 2001 - From: "Martin Gadbois" <martin.gadbois@colubris.com> - -Finally!! -Here's a web site with H/W acceleration patch for FreeS/WAN 1.91, including -S/W and Hifn 7901 crypto support. - -http://sources.colubris.com/ - -Martin Gadbois</PRE> -<P>Hardware accelerators could take performance well beyond what - FreeS/WAN can do in software (discussed<A href="performance.html"> here</A> -). Here is some discussion off the IETF IPsec list, October 2001:</P> -<PRE> ... Currently shipping chips deliver, 600 mbps throughput on a single - stream of 3DES IPsec traffic. There are also chips that use multiple - cores to do 2.4 gbps. We (Cavium) and others have announced even faster - chips. ... Mid 2002 versions will handle at line rate (OC48 and OC192) - IPsec and SSL/TLS traffic not only 3DES CBC but also AES and arc4.</PRE> -<P>The patches to date support chips that have been in production for - some time, not the state-of-the-art latest-and-greatest devices - described in that post. However, they may still outperform software and - they almost certainly reduce CPU overhead.</P> -<H2><A name="ipv6">IP version 6 (IPng)</A></H2> -<P>The Internet currently runs on version four of the IP protocols. IPv4 - is what is in the standard Linux IP stack, and what FreeS/WAN was built - for. In IPv4, IPsec is an optional feature.</P> -<P>The next version of the IP protocol suite is version six, usually - abbreviated either as "IPv6" or as "IPng" for "IP: the next - generation". For IPv6, IPsec is a required feature. Any machine doing - IPv6 is required to support IPsec, much as any machine doing (any - version of) IP is required to support ICMP.</P> -<P>There is a Linux implementation of IPv6 in Linux kernels 2.2 and - above. For details, see the<A href="http://www.cs-ipv6.lancs.ac.uk/ipv6/systems/linux/faq/"> - FAQ</A>. It does not yet support IPsec. The<A href="http://www.linux-ipv6.org/"> - USAGI</A> project are also working on IPv6 for Linux.</P> -<P>FreeS/WAN was originally built for the current standard, IPv4, but we - are interested in seeing it work with IPv6. Some progress has been - made, and a patched version with IPv6 support is<A href="http://www.ipv6.iabg.de/downloadframe/index.html"> - available</A>. For more recent information, check the<A href="mail.html"> - mailing list</A>.</P> -<H3><A name="v6.back">IPv6 background</A></H3> -<P>IPv6 has been specified by an IETF<A href="http://www.ietf.org/html.charters/ipngwg-charter.html"> - working group</A>. The group's page lists over 30 RFCs to date, and - many Internet Drafts as well. The overview is<A href="http://www.ietf.org/rfc/rfc2460.txt"> - RFC 2460</A>. Major features include:</P> -<UL> -<LI>expansion of the address space from 32 to 128 bits,</LI> -<LI>changes to improve support for -<UL> -<LI>mobile IP</LI> -<LI>automatic network configuration</LI> -<LI>quality of service routing</LI> -<LI>...</LI> -</UL> -</LI> -<LI>improved security via IPsec</LI> -</UL> -<P>A number of projects are working on IPv6 implementation. A prominent - Open Source effort is<A href="http://www.kame.net/"> KAME</A>, a - collaboration among several large Japanese companies to implement IPv6 - for Berkeley Unix. Other major players are also working on IPv6. For - example, see pages at:</P> -<UL> -<LI><A href="http://playground.sun.com/pub/ipng/html/ipng-main.html">Sun</A> -</LI> -<LI><A href="http://www.cisco.com/warp/public/732/ipv6/index.html">Cisco</A> -</LI> -<LI><A href="http://www.microsoft.com/windows2000/techinfo/howitworks/communications/networkbasics/IPv6.asp"> -Microsoft</A></LI> -</UL> -<P>The<A href="http://www.6bone.net/"> 6bone</A> (IPv6 backbone) testbed - network has been up for some time. There is an active<A href="http://www.ipv6.org/"> - IPv6 user group</A>.</P> -<P>One of the design goals for IPv6 was that it must be possible to - convert from v4 to v6 via a gradual transition process. Imagine the - mess if there were a "flag day" after which the entire Internet used - v6, and all software designed for v4 stopped working. Almost every - computer on the planet would need major software changes! There would - be huge costs to replace older equipment. Implementers would be worked - to death before "the day", systems administrators and technical support - would be completely swamped after it. The bugs in every implementation - would all bite simultaneously. Large chunks of the net would almost - certainly be down for substantial time periods. ...</P> -<P>Fortunately, the design avoids any "flag day". It is therefore a - little tricky to tell how quickly IPv6 will take over. The transition - has certainly begun. For examples, see announcements from<A href="http://www.mailbase.ac.uk/lists/internet2/2000-03/0016.html"> - NTT</A> and<A href="http://www.vnunet.com/News/1102383"> Nokia</A>. - However, it is not yet clear how quickly the process will gain - momentum, or when it will be completed. Likely large parts of the - Internet will remain with IPv4 for years to come.</P> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="trouble.html">Previous</A> -<A HREF="interop.html">Next</A> -</BODY> -</HTML> diff --git a/doc/config.html b/doc/config.html deleted file mode 100644 index 4e9f0a513..000000000 --- a/doc/config.html +++ /dev/null @@ -1,308 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="install.html">Previous</A> -<A HREF="background.html">Next</A> -<HR> -<H1><A NAME="config">How to configure FreeS/WAN</A></H1> -<P>This page will teach you how to configure a simple network-to-network - link or a Road Warrior connection between two Linux FreeS/WAN boxes.</P> -<P>See also these related documents:</P> -<UL> -<LI>our<A HREF="quickstart.html#quickstart"> quickstart</A> guide to<A HREF="glossary.html#carpediem"> - opportunistic encryption</A></LI> -<LI>our guide to configuration with<A HREF="policygroups.html#policygroups"> - policy groups</A></LI> -<LI>our<A HREF="adv_config.html#adv_config"> advanced configuration</A> - document</LI> -</UL> -<P> The network-to-network setup allows you to connect two office - networks into one Virtual Private Network, while the Road Warrior - connection secures a laptop's telecommute to work. Our examples also - show the basic procedure on the Linux FreeS/WAN side where another - IPsec peer is in play.</P> -<P> Shortcut to<A HREF="#config.netnet"> net-to-net</A>. -<BR> Shortcut to<A HREF="#config.rw"> Road Warrior</A>.</P> -<H2><A NAME="16_1">Requirements</A></H2> -<P>To configure the network-to-network connection you must have:</P> -<UL> -<LI>two Linux gateways with static IPs</LI> -<LI>a network behind each gate. Networks must have non-overlapping IP - ranges.</LI> -<LI>Linux FreeS/WAN<A HREF="install.html#install"> installed</A> on both - gateways</LI> -<LI><A HREF="http://www.tcpdump.org"><VAR>tcpdump</VAR></A> on the local - gate, to test the connection</LI> -</UL> -<P>For the Road Warrior you need:</P> -<UL> -<LI>one Linux box with a static IP</LI> -<LI>a Linux laptop with a dynamic IP</LI> -<LI>Linux FreeS/WAN installed on both</LI> -<LI>for testing,<VAR> tcpdump</VAR> on your gateway or laptop</LI> -</UL> -<P>If both IPs are dynamic, your situation is a bit trickier. Your best - bet is a variation on the<A HREF="#config.rw"> Road Warrior</A>, as - described in<A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00282.html"> - this mailing list message</A>.</P> -<H2><A name="config.netnet"></A>Net-to-Net connection</H2> -<H3><A name="netnet.info.ex">Gather information</A></H3> -<P>For each gateway, compile the following information:</P> -<UL> -<LI>gateway IP</LI> -<LI>IP range of the subnet you will be protecting. This doesn't have to - be your whole physical subnet.</LI> -<LI>a name by which that gateway can identify itself for IPsec - negotiations. Its form is a Fully Qualified Domain Name preceded by an - @ sign, ie. @xy.example.com. -<BR> It does not need to be within a domain that you own. It can be a - made-up name.</LI> -</UL> -<H4>Get your leftrsasigkey</H4> -<P>On your local Linux FreeS/WAN gateway, print your IPsec public key:</P> -<PRE> ipsec showhostkey --left</PRE> -<P>The output should look like this (with the key shortened for easy - reading):</P> -<PRE> # RSA 2048 bits xy.example.com Fri Apr 26 15:01:41 2002 - leftrsasigkey=0sAQOnwiBPt...</PRE> -<P>Don't have a key? Use<A HREF="manpage.d/ipsec_newhostkey.8.html"><VAR> - ipsec newhostkey</VAR></A> to create one.</P> -<H4>...and your rightrsasigkey</H4> -<P>Get a console on the remote side:</P> -<PRE> ssh2 ab.example.com</PRE> -<P>In that window, type:</P> -<PRE> ipsec showhostkey --right</PRE> -<P>You'll see something like:</P> -<PRE> # RSA 2192 bits ab.example.com Thu May 16 15:26:20 2002 - rightrsasigkey=0sAQOqH55O...</PRE> -<H3><A NAME="16_2_2">Edit<VAR> /etc/ipsec.conf</VAR></A></H3> -<P>Back on the local gate, copy our template to<VAR> /etc/ipsec.conf</VAR> -. (on Mandrake,<VAR> /etc/freeswan/ipsec.conf</VAR>). Substitute the - information you've gathered for our example data.</P> -<PRE>conn net-to-net - left=192.0.2.2 # Local vitals - leftsubnet=192.0.2.128/29 # - leftid=@xy.example.com # - leftrsasigkey=0s1LgR7/oUM... # - leftnexthop=%defaultroute # correct in many situations - right=192.0.2.9 # Remote vitals - rightsubnet=10.0.0.0/24 # - rightid=@ab.example.com # - rightrsasigkey=0sAQOqH55O... # - rightnexthop=%defaultroute # correct in many situations - auto=add # authorizes but doesn't start this - # connection at startup</PRE> -<P> "Left" and "right" should represent the machines that have FreeS/WAN - installed on them, and "leftsubnet" and "rightsubnet" machines that are - being protected. /32 is assumed for left/right and left/rightsubnet - parameters.</P> -<P>Copy<VAR> conn net-to-net</VAR> to the remote-side /etc/ipsec.conf. - If you've made no other modifications to either<VAR> ipsec.conf</VAR>, - simply:</P> -<PRE> scp2 ipsec.conf root@ab.example.com:/etc/ipsec.conf</PRE> -<H3><A NAME="16_2_3">Start your connection</A></H3> -<P>Locally, type:</P> -<PRE> ipsec auto --up net-to-net</PRE> -<P>You should see:</P> -<PRE> 104 "net-net" #223: STATE_MAIN_I1: initiate - 106 "net-net" #223: STATE_MAIN_I2: sent MI2, expecting MR2 - 108 "net-net" #223: STATE_MAIN_I3: sent MI3, expecting MR3 - 004 "net-net" #223: STATE_MAIN_I4: ISAKMP SA established - 112 "net-net" #224: STATE_QUICK_I1: initiate - 004 "net-net" #224: STATE_QUICK_I2: sent QI2, IPsec SA established</PRE> -<P>The important thing is<VAR> IPsec SA established</VAR>. If you're - unsuccessful, see our<A HREF="trouble.html#trouble"> troubleshooting - tips</A>.</P> -<H3><A NAME="16_2_4">Do not MASQ or NAT packets to be tunneled</A></H3> -<P>If you are using<A HREF="glossary.html#masq"> IP masquerade</A> or<A HREF="glossary.html#NAT.gloss"> - Network Address Translation (NAT)</A> on either gateway, you must now - exempt the packets you wish to tunnel from this treatment. For example, - if you have a rule like:</P> -<PRE>iptables -t nat -A POSTROUTING -o eth0 -s 10.0.0.0/24 -j MASQUERADE -</PRE> -<P>change it to something like:</P> -<PRE>iptables -t nat -A POSTROUTING -o eth0 -s 10.0.0.0/24 -d \! 192.0.2.128/29 -j MASQUERADE</PRE> -<P>This may be necessary on both gateways.</P> -<H3><A NAME="16_2_5">Test your connection</A></H3> -<P>Sit at one of your local subnet nodes (not the gateway), and ping a - subnet node on the other (again, not the gateway).</P> -<PRE> ping fileserver.toledo.example.com</PRE> -<P>While still pinging, go to the local gateway and snoop your outgoing - interface, for example:</P> -<PRE> tcpdump -i ppp0</PRE> -<P>You want to see ESP (Encapsulating Security Payload) packets moving<B> - back and forth</B> between the two gateways at the same frequency as - your pings:</P> -<PRE> 19:16:32.046220 192.0.2.2 > 192.0.2.9: ESP(spi=0x3be6c4dc,seq=0x3) - 19:16:32.085630 192.0.2.9 > 192.0.2.2: ESP(spi=0x5fdd1cf8,seq=0x6)</PRE> -<P>If you see this, congratulations are in order! You have a tunnel - which will protect any IP data from one subnet to the other, as it - passes between the two gates. If not, go and<A HREF="trouble.html#trouble"> - troubleshoot</A>.</P> -<P>Note: your new tunnel protects only net-net traffic, not - gateway-gateway, or gateway-subnet. If you need this (for example, if - machines on one net need to securely contact a fileserver on the IPsec - gateway), you'll need to create<A HREF="adv_config.html#adv_config"> - extra connections</A>.</P> -<H3><A NAME="16_2_6">Finishing touches</A></H3> -<P>Now that your connection works, name it something sensible, like:</P> -<PRE>conn winstonnet-toledonet</PRE> -<P>To have the tunnel come up on-boot, replace</P> -<PRE> auto=add</PRE> -<P>with:</P> -<PRE> auto=start</PRE> -<P>Copy these changes to the other side, for example:</P> -<PRE> scp2 ipsec.conf root@ab.example.com:/etc/ipsec.conf</PRE> -<P>Enjoy!</P> -<H2><A name="config.rw"></A>Road Warrior Configuration</H2> -<H3><A name="rw.info.ex">Gather information</A></H3> -<P>You'll need to know:</P> -<UL> -<LI>the gateway's static IP</LI> -<LI>the IP range of the subnet behind that gateway</LI> -<LI>a name by which each side can identify itself for IPsec - negotiations. Its form is a Fully Qualified Domain Name preceded by an - @ sign, ie. @road.example.com. -<BR> It does not need to be within a domain that you own. It can be a - made-up name.</LI> -</UL> -<H4>Get your leftrsasigkey...</H4> -<P>On your laptop, print your IPsec public key:</P> -<PRE> ipsec showhostkey --left</PRE> -<P>The output should look like this (with the key shortened for easy - reading):</P> -<PRE> # RSA 2192 bits road.example.com Sun Jun 9 02:45:02 2002 - leftrsasigkey=0sAQPIPN9uI...</PRE> -<P>Don't have a key? See<A HREF="old_config.html#genrsakey"> these - instructions</A>.</P> -<H4>...and your rightrsasigkey</H4> -<P>Get a console on the gateway:</P> -<PRE> ssh2 xy.example.com</PRE> -<P>View the gateway's public key with:</P> -<PRE> ipsec showhostkey --right</PRE> -<P>This will yield something like</P> -<PRE> # RSA 2048 bits xy.example.com Fri Apr 26 15:01:41 2002 - rightrsasigkey=0sAQOnwiBPt...</PRE> -<H3><A NAME="16_3_2">Customize<VAR> /etc/ipsec.conf</VAR></A></H3> -<P>On your laptop, copy this template to<VAR> /etc/ipsec.conf</VAR>. (on - Mandrake,<VAR> /etc/freeswan/ipsec.conf</VAR>). Substitute the - information you've gathered for our example data.</P> -<PRE>conn road - left=%defaultroute # Picks up our dynamic IP - leftnexthop=%defaultroute # - leftid=@road.example.com # Local information - leftrsasigkey=0sAQPIPN9uI... # - right=192.0.2.10 # Remote information - rightsubnet=10.0.0.0/24 # - rightid=@xy.example.com # - rightrsasigkey=0sAQOnwiBPt... # - auto=add # authorizes but doesn't start this - # connection at startup</PRE> -<P>The template for the gateway is different. Notice how it reverses<VAR> - left</VAR> and<VAR> right</VAR>, in keeping with our convention that<STRONG> - L</STRONG>eft is<STRONG> L</STRONG>ocal,<STRONG> R</STRONG>ight<STRONG> - R</STRONG>emote. Be sure to switch your rsasigkeys in keeping with - this.</P> -<PRE> ssh2 xy.example.com - vi /etc/ipsec.conf</PRE> -<P>and add:</P> -<PRE>conn road - left=192.0.2.2 # Gateway's information - leftid=@xy.example.com # - leftsubnet=192.0.2.128/29 # - leftrsasigkey=0sAQOnwiBPt... # - rightnexthop=%defaultroute # correct in many situations - right=%any # Wildcard: we don't know the laptop's IP - rightid=@road.example.com # - rightrsasigkey=0sAQPIPN9uI... # - auto=add # authorizes but doesn't start this - # connection at startup</PRE> -<H3><A NAME="16_3_3">Start your connection</A></H3> -<P>You must start the connection from the Road Warrior side. On your - laptop, type:</P> -<PRE> ipsec auto --start net-to-net</PRE> -<P>You should see:</P> -<PRE>104 "net-net" #223: STATE_MAIN_I1: initiate -106 "road" #301: STATE_MAIN_I2: sent MI2, expecting MR2 -108 "road" #301: STATE_MAIN_I3: sent MI3, expecting MR3 -004 "road" #301: STATE_MAIN_I4: ISAKMP SA established -112 "road" #302: STATE_QUICK_I1: initiate -004 "road" #302: STATE_QUICK_I2: sent QI2, IPsec SA established</PRE> -<P>Look for<VAR> IPsec SA established</VAR>. If you're unsuccessful, see - our<A HREF="trouble.html#trouble"> troubleshooting tips</A>.</P> -<H3><A NAME="16_3_4">Do not MASQ or NAT packets to be tunneled</A></H3> -<P>If you are using<A HREF="glossary.html#masq"> IP masquerade</A> or<A HREF="glossary.html#NAT.gloss"> - Network Address Translation (NAT)</A> on either gateway, you must now - exempt the packets you wish to tunnel from this treatment. For example, - if you have a rule like:</P> -<PRE>iptables -t nat -A POSTROUTING -o eth0 -s 10.0.0.0/24 -j MASQUERADE -</PRE> -<P>change it to something like:</P> -<PRE>iptables -t nat -A POSTROUTING -o eth0 -s 10.0.0.0/24 -d \! 192.0.2.128/29 -j MASQUERADE</PRE> -<H3><A NAME="16_3_5">Test your connection</A></H3> -<P>From your laptop, ping a subnet node behind the remote gateway. Do - not choose the gateway itself for this test.</P> -<PRE> ping ns.winston.example.com</PRE> -<P>Snoop the packets exiting the laptop, with a command like:</P> -<PRE> tcpdump -i wlan0</PRE> -<P>You have success if you see (Encapsulating Security Payload) packets - travelling<B> in both directions</B>:</P> -<PRE> 19:16:32.046220 192.0.2.2 > 192.0.2.9: ESP(spi=0x3be6c4dc,seq=0x3) - 19:16:32.085630 192.0.2.9 > 192.0.2.2: ESP(spi=0x5fdd1cf8,seq=0x6)</PRE> -<P>If you do, great! Traffic between your Road Warrior and the net - behind your gateway is protected. If not, see our<A HREF="trouble.html#trouble"> - troubleshooting hints</A>.</P> -<P>Your new tunnel protects only traffic addressed to the net, not to - the IPsec gateway itself. If you need the latter, you'll want to make - an<A HREF="adv_config.html#adv_config"> extra tunnel.</A>.</P> -<H3><A NAME="16_3_6">Finishing touches</A></H3> -<P>On both ends, name your connection wisely, like:</P> -<PRE>conn mike-to-office</PRE> -<P><B>On the laptop only,</B> replace</P> -<PRE> auto=add</PRE> -<P>with:</P> -<PRE> auto=start</PRE> -<P>so that you'll be connected on-boot.</P> -<P>Happy telecommuting!</P> -<H3><A NAME="16_3_7">Multiple Road Warriors</A></H3> -<P>If you're using RSA keys, as we did in this example, you can add as - many Road Warriors as you like. The left/rightid parameter lets Linux - FreeS/WAN distinguish between multiple Road Warrior peers, each with - its own public key.</P> -<P>The situation is different for shared secrets (PSK). During a PSK - negotiation, ID information is not available at the time Pluto is - trying to determine which secret to use, so, effectively, you can only - define one Roadwarrior connection. All your PSK road warriors must - therefore share one secret.</P> -<H2><A NAME="16_4">What next?</A></H2> -<P>Using the principles illustrated here, you can try variations such - as:</P> -<UL> -<LI>a telecommuter with a static IP</LI> -<LI>a road warrior with a subnet behind it</LI> -</UL> -<P>Or, look at some of our<A HREF="adv_config.html#adv_config"> more - complex configuration examples.</A>.</P> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="install.html">Previous</A> -<A HREF="background.html">Next</A> -</BODY> -</HTML> diff --git a/doc/faq.html b/doc/faq.html deleted file mode 100644 index b0fed502e..000000000 --- a/doc/faq.html +++ /dev/null @@ -1,2339 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="policygroups.html">Previous</A> -<A HREF="manpages.html">Next</A> -<HR> -<H1><A NAME="5">FreeS/WAN FAQ</A></H1> -<P>This is a collection of questions and answers, mostly taken from the - FreeS/WAN<A href="mail.html"> mailing list</A>. See the project<A href="http://www.freeswan.org/"> - web site</A> for more information. All the FreeS/WAN documentation is - online there.</P> -<P>Contributions to the FAQ are welcome. Please send them to the project<A -href="mail.html"> mailing list</A>.</P> -<HR> -<H2><A name="questions">Index of FAQ questions</A></H2> -<UL> -<LI><A href="#whatzit">What is FreeS/WAN?</A></LI> -<LI><A href="#problems">How do I report a problem or seek help?</A></LI> -<LI><A href="#generic">Can I get ...</A> -<UL> -<LI><A href="#lemme_out">... an off-the-shelf system that includes - FreeS/WAN?</A></LI> -<LI><A href="#contractor">... contractors or staff who know FreeS/WAN?</A> -</LI> -<LI><A href="#commercial">... commercial support?</A></LI> -</UL> -</LI> -<LI><A href="#release">Release questions</A> -<UL> -<LI><A href="#rel.current">What is the current release?</A></LI> -<LI><A href="#relwhen">When is the next release?</A></LI> -<LI><A href="#rel.bugs">Are there known bugs in the current release?</A></LI> -</UL> -</LI> -<LI><A href="mod_cons">Modifications and contributions</A> -<UL> -<LI><A href="#modify.faq">Can I modify FreeS/WAN to ...?</A></LI> -<LI><A href="#contrib.faq">Can I contribute to the project?</A></LI> -<LI><A href="#ddoc.faq">Is there detailed design documentation?</A></LI> -</UL> -</LI> -<LI><A href="#interact">Will FreeS/WAN work in my environment?</A> -<UL> -<LI><A href="#interop.faq">Can FreeS/WAN talk to ... ?</A></LI> -<LI><A href="#old_to_new">Can different FreeS/WAN versions talk to each - other?</A></LI> -<LI><A href="#faq.bandwidth">Is there a limit on throughput?</A></LI> -<LI><A href="#faq.number">Is there a limit on number of connections?</A></LI> -<LI><A href="#faq.speed">Is a ... fast enough to handle FreeS/WAN with - my loads?</A></LI> -</UL> -</LI> -<LI><A href="#work_on">Will FreeS/WAN work on ...</A> -<UL> -<LI><A href="#versions">... my version of Linux?</A></LI> -<LI><A href="#nonIntel.faq">... non-Intel CPUs?</A></LI> -<LI><A href="#multi.faq">... multiprocessors?</A></LI> -<LI><A href="#k.old">... an older kernel?</A></LI> -<LI><A href="#k.versions">... the latest kernel version?</A></LI> -<LI><A href="#interface.faq">... unusual network hardware?</A></LI> -<LI><A href="#vlan">... a VLAN (802.1q) network?</A></LI> -</UL> -</LI> -<LI><A href="#features.faq">Does FreeS/WAN support ...</A> -<UL> -<LI><A href="#VPN.faq">... site-to-site VPN applications</A></LI> -<LI><A href="#warrior.faq">... remote users connecting to a LAN</A></LI> -<LI><A href="#road.shared.possible">... remote users using shared secret - authentication?</A></LI> -<LI><A href="#wireless.faq">... wireless networks</A></LI> -<LI><A href="#PKIcert">... X.509 or other PKI certificates?</A></LI> -<LI><A href="#Radius">... user authentication (Radius, SecureID, Smart - Card ...)?</A></LI> -<LI><A href="#NATtraversal">... NAT traversal</A></LI> -<LI><A href="#virtID">... assigning a "virtual identity" to a remote - system?</A></LI> -<LI><A href="#noDES.faq">... single DES encryption?</A></LI> -<LI><A href="#AES.faq">... AES encryption?</A></LI> -<LI><A href="#other.cipher">... other encryption algorithms?</A></LI> -</UL> -</LI> -<LI><A href="#canI">Can I ...</A> -<UL> -<LI><A href="#policy.preconfig">...use policy groups along with - explicitly configured connections?</A></LI> -<LI><A href="#policy.off">...turn off policy groups?</A></LI> - -<!-- - <li><a href="#policy.otherinterface">...use policy groups - on an interface other than <VAR>%defaultroute</VAR>?</a></li> ---> -<LI><A href="#reload">... reload connection info without restarting?</A></LI> -<LI><A href="#masq.faq">... use several masqueraded subnets?</A></LI> -<LI><A href="#dup_route">... use subnets masqueraded to the same - addresses?</A></LI> -<LI><A href="#road.masq">... assign a road warrior an address on my net - (a virtual identity)?</A></LI> -<LI><A href="#road.many">... support many road warriors with one - gateway?</A></LI> -<LI><A href="#road.PSK">... have many road warriors using shared secret - authentication?</A></LI> -<LI><A href="#QoS">... use Quality of Service routing with FreeS/WAN?</A> -</LI> -<LI><A href="#deadtunnel">... recognise dead tunnels and shut them down?</A> -</LI> -<LI><A href="#demanddial">... build IPsec tunnels over a demand-dialed - link?</A></LI> -<LI><A href="#GRE">... build GRE, L2TP or PPTP tunnels over IPsec?</A></LI> -<LI><A href="#NetBIOS">... use Network Neighborhood (Samba, NetBIOS) - over IPsec?</A></LI> -</UL> -</LI> -<LI><A href="#setup.faq">Life's little mysteries</A> -<UL> -<LI><A href="#cantping">I cannot ping ....</A></LI> -<LI><A href="#forever">It takes forever to ...</A></LI> -<LI><A href="#route">I send packets to the tunnel with route(8) but they - vanish</A></LI> -<LI><A href="#down_route">When a tunnel goes down, packets vanish</A></LI> -<LI><A href="#firewall_ate">The firewall ate my packets!</A></LI> -<LI><A href="#dropconn">Dropped connections</A></LI> -<LI><A href="#defaultroutegone">Disappearing %defaultroute</A></LI> -<LI><A href="#tcpdump.faq">TCPdump on the gateway shows strange things</A> -</LI> -<LI><A href="#no_trace">Traceroute does not show anything between the - gateways</A></LI> -</UL> -</LI> -<LI><A href="#man4debug">Testing in stages (or .... works but ... - doesn't)</A> -<UL> -<LI><A href="#nomanual">Manually keyed connections don't work</A></LI> -<LI><A href="#spi_error">One manual connection works, but second one - fails</A></LI> -<LI><A href="#man_no_auto">Manual connections work, but automatic keying - doesn't</A></LI> -<LI><A href="#nocomp">IPsec works, but connections using compression - fail</A></LI> -<LI><A href="#pmtu.broken">Small packets work, but large transfers fail</A> -</LI> -<LI><A href="#subsub">Subnet-to-subnet works, but tests from the - gateways don't</A></LI> -</UL> -</LI> -<LI><A href="#compile.faq">Compilation problems</A> -<UL> -<LI><A href="#gmp.h_missing">gmp.h: No such file or directory</A></LI> -<LI><A href="#noVM">... virtual memory exhausted</A></LI> -</UL> -</LI> -<LI><A href="#error">Interpreting error messages</A> -<UL> -<LI><A href="#route-client">route-client (or host) exited with status 7</A> -</LI> -<LI><A href="#unreachable">SIOCADDRT:Network is unreachable</A></LI> -<LI><A href="#modprobe">ipsec_setup: modprobe: Can't locate moduleipsec</A> -</LI> -<LI><A href="#noKLIPS">ipsec_setup: Fatal error, kernel appears to lack - KLIPS</A></LI> -<LI><A href="#noDNS">ipsec_setup: ... failure to fetch key for ... from - DNS</A></LI> -<LI><A href="#dup_address">ipsec_setup: ... interfaces ... and ... share - address ...</A></LI> -<LI><A href="#kflags">ipsec_setup: Cannot adjust kernel flags</A></LI> -<LI><A href="#message_num">Message numbers (MI3, QR1, et cetera) in - Pluto messages</A></LI> -<LI><A href="#conn_name">Connection names in Pluto error messages</A></LI> -<LI><A href="#cantorient">Pluto: ... can't orient connection</A></LI> -<LI><A href="#no.interface">... we have no ipsecN interface for either - end of this connection</A></LI> -<LI><A href="#noconn">Pluto: ... no connection is known</A></LI> -<LI><A href="#nosuit">Pluto: ... no suitable connection ...</A></LI> -<LI><A href="#noconn.auth">Pluto: ... no connection has been authorized</A> -</LI> -<LI><A href="#noDESsupport">Pluto: ... OAKLEY_DES_CBC is not supported.</A> -</LI> -<LI><A href="#notransform">Pluto: ... no acceptable transform</A></LI> -<LI><A href="#rsasigkey">rsasigkey dumps core</A></LI> -<LI><A href="#sig4">!Pluto failure!: ... exited with ... signal 4</A></LI> -<LI><A href="#econnrefused">ECONNREFUSED error message</A></LI> -<LI><A href="#no_eroute">klips_debug: ... no eroute!</A></LI> -<LI><A href="#SAused">... trouble writing to /dev/ipsec ... SA already - in use</A></LI> -<LI><A href="#ignore">... ignoring ... payload</A></LI> -<LI><A href="#unknown_rightcert">unknown parameter name "rightcert"</A></LI> -</UL> -</LI> -<LI><A href="#spam">Why don't you restrict the mailing lists to reduce - spam?</A></LI> -</UL> -<HR> -<H2><A name="whatzit">What is FreeS/WAN?</A></H2> -<P>FreeS/WAN is a Linux implementation of the<A href="glossary.html#IPSEC"> - IPsec</A> protocols, providing security services at the IP (Internet - Protocol) level of the network.</P> -<P>For more detail, see our<A href="intro.html"> introduction</A> - document or the FreeS/WAN project<A href="http://www.freeswan.org/"> - web site</A>.</P> -<P>To start setting it up, go to our<A href="quickstart.html"> - quickstart guide</A>.</P> -<P>Our<A href="web.html"> web links</A> document has information on<A href="web.html#implement"> - IPsec for other systems</A>.</P> -<H2><A name="problems">How do I report a problem or seek help?</A></H2> -<DL> -<DT>Read our<A href="trouble.html"> troubleshooting</A> document.</DT> -<DD> -<P>It may guide you to a solution. If not, see its<A href="trouble.html#prob.report"> - problem reporting</A> section.</P> -<P>Basically, what it says is<STRONG> give us the output from<VAR> ipsec - barf</VAR> from both gateways</STRONG>. Without full information, we - cannot diagnose a problem. However,<VAR> ipsec barf</VAR> produces a - lot of output. If at all possible,<STRONG> please make barfs accessible - via the web or FTP</STRONG> rather than sending enormous mail messages.</P> -</DD> -<DT><STRONG>Use the<A href="mail.html"> users mailing list</A> for - problem reports</STRONG>, rather than mailing developers directly.</DT> -<DD> -<UL> -<LI>This gives you access to more expertise, including users who may - have encountered and solved the same problems.</LI> -<LI>It is more likely to get a quick response. Developers may get behind - on email, or even ignore it entirely for a while, but a list message - (given a reasonable Subject: line) is certain to be read by a fair - number of people within hours.</LI> -<LI>It may also be important because of<A href="politics.html#exlaw"> - cryptography export laws</A>. A US citizen who provides technical - assistance to foreign cryptographic work might be charged under the - arms export regulations. Such a charge would be easier to defend if the - discussion took place on a public mailing list than if it were done in - private mail.</LI> -</UL> -</DD> -<DT>Try irc.freenode.net#freeswan.</DT> -<DD> -<P>FreeS/WAN developers, volunteers and users can often be found there. - Be patient and be prepared to provide lots of information to support - your question.</P> -<P>If your question was really interesting, and you found an answer, - please share that with the class by posting to the<A href="mail.html"> - users mailing list</A>. That way others with the same problem can find - your answer in the archives.</P> -</DD> -<DT>Premium support is also available.</DT> -<DD> -<P>See the next several questions.</P> -</DD> -</DL> -<H2><A name="generic">Can I get ...</A></H2> -<H3><A name="lemme_out">Can I get an off-the-shelf system that includes - FreeS/WAN?</A></H3> -<P>There are a number of Linux distributions or firewall products which - include FreeS/WAN. See this<A href="intro.html#products"> list</A>. - Using one of these, chosen to match your requirements and budget, may - save you considerable time and effort.</P> -<P>If you don't know your requirements, start by reading Schneier's<A href="biblio.html#secrets"> - Secrets and Lies</A>. That gives the best overview of security issues I - have seen. Then consider hiring a consultant (see next question) to - help define your requirements.</P> -<H3><A name="consultant">Can I hire consultants or staff who know - FreeS/WAN?</A></H3> -<P>If you want the help of a contractor, or to hire staff with FreeS/WAN - expertise, you could:</P> -<UL> -<LI>check availability in your area through your local Linux User Group - (<A href="http://lugww.counter.li.org/">LUG Index</A>)</LI> -<LI>try asking on our<A href="mail.html"> mailing list</A></LI> -</UL> -<P>For companies offerring support, see the next question.</P> -<H3><A name="commercial">Can I get commercial support?</A></H3> -<P>Many of the distributions or firewall products which include - FreeS/WAN (see this<A href="intro.html#products"> list</A>) come with - commercial support or have it available as an option.</P> -<P>Various companies specialize in commercial support of open source - software. Our project leader was a founder of the first such company, - Cygnus Support. It has since been bought by<A href="http://www.redhat.com"> - Redhat</A>. Another such firm is<A href="http://www.linuxcare.com"> - Linuxcare</A>.</P> -<H2><A name="release">Release questions</A></H2> -<H3><A name="rel.current">What is the current release?</A></H3> -<P>The current release is the highest-numbered tarball on our<A href="ftp://ftp.xs4all.nl/pub/crypto/freeswan"> - distribution site</A>. Almost always, any of<A href="intro.html#mirrors"> - the mirrors</A> will have the same file, though perhaps not for a day - or so after a release.</P> -<P>Unfortunately, the web site is not always updated as quickly as it - should be.</P> -<H3><A name="relwhen">When is the next release?</A></H3> -<P>We try to do a release approximately every six to eight weeks.</P> -<P>If pre-release tests fail and the fix appears complex, or more - generally if the code does not appear stable when a release is - scheduled, we will just skip that release.</P> -<P>For serious bugs, we may bring out an extra bug-fix release. These - get numbers in the normal release series. For example, there was a bug - found in FreeS/WAN 1.6, so we did another release less than two weeks - later. The bug-fix release was called 1.7.</P> -<H3><A name="rel.bugs">Are there known bugs in the current release?</A></H3> -<P>Any problems we are aware of at the time of a release are documented - in the<A href="../BUGS"> BUGS</A> file for that release. You should - also look at the<A href="../CHANGES"> CHANGES</A> file.</P> -<P>Bugs discovered after a release are discussed on the<A href="mail.html"> - mailing lists</A>. The easiest way to check for any problems in the - current code would be to peruse the<A href="http://lists.freeswan.org/pipermail/briefs"> - List In Brief</A>.</P> -<H2><A name="mod_cons">Modifications and contributions</A></H2> -<H3><A name="modify.faq">Can I modify FreeS/WAN to ...?</A></H3> -<P>You are free to modify FreeS/WAN in any way. See the discussion of<A href="intro.html#licensing"> - licensing</A> in our introduction document.</P> -<P>Before investing much energy in any such project, we suggest that you</P> -<UL> -<LI>check the list of<A href="web.html#patch"> existing patches</A></LI> -<LI>post something about your project to the<A href="mail.html"> design - mailing list</A></LI> -</UL> -<P>This may prevent duplicated effort, or lead to interesting - collaborations.</P> -<H3><A name="contrib.faq">Can I contribute to the project?</A></H3> - In general, we welcome contributions from the community. Various - contributed patches, either to fix bugs or to add features, have been - incorporated into our distribution. Other patches, not yet included in - the distribution, are listed in our<A href="web.html#patch"> web links</A> - section. -<P>Users have also contributed heavily to documentation, both by - creating their own<A href="intro.html#howto"> HowTos</A> and by posting - things on the<A href="mail.html"> mailing lists</A> which I have quoted - in these HTML docs.</P> -<P>There are, however, some caveats.</P> -<P>FreeS/WAN is being implemented in Canada, by Canadians, largely to - ensure that is it is entirely free of export restrictions. See this<A href="politics.html#status"> - discussion</A>. We<STRONG> cannot accept code contributions from US - residents or citizens</STRONG>, not even one-line bugs fixes. The - reasons for this were recently discussed extensively on the mailing - list, in a thread starting<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/01/msg00111.html"> - here</A>.</P> -<P>Not all contributions are of interest to us. The project has a set of - fairly ambitious and quite specific goals, described in our<A href="intro.html#goals"> - introduction</A>. Contributions that lead toward these goals are likely - to be welcomed enthusiastically. Other contributions may be seen as - lower priority, or even as a distraction.</P> -<P>Discussion of possible contributions takes place on the<A href="mail.html"> - design mailing list</A>.</P> -<H3><A name="ddoc.faq">Is there detailed design documentation?</A></H3> - There are: -<UL> -<LI><A href="rfc.html">RFCs</A> specifying the protocols we implement</LI> -<LI><A href="manpages.html">man pages</A> for our utilities, library - functions and file formats</LI> -<LI>comments in the source code</LI> -<LI><A href="index.html">HTML documentation</A> written primarily for - users</LI> -<LI>archived discussions from the<A href="mail.html"> mailing lists</A></LI> -<LI>other papers mentioned in our<A href="intro.html#applied"> - introduction</A></LI> -</UL> -<P>The only formal design documents are a few papers in the last - category above. All the other categories, however, have things to say - about design as well.</P> -<H2><A name="interact">Will FreeS/WAN work in my environment?</A></H2> -<H3><A name="interop.faq">Can FreeS/WAN talk to ...?</A></H3> -<P>The IPsec protocols are designed to support interoperation. In - theory, any two IPsec implementations should be able to talk to each - other. In practice, it is considerably more complex. We have a whole<A href="interop.html"> - interoperation document</A> devoted to this problem.</P> -<P>An important part of that document is links to the many<A href="interop.html#otherpub"> - user-written HowTos</A> on interoperation between FreeS/WAN and various - other implementations. Often the users know more than the developers - about these issues (and almost always more than me :-), so these - documents may be your best resource.</P> -<H3><A name="old_to_new">Can different FreeS/WAN versions talk to each - other?</A></H3> -<P>Linux FreeS/WAN can interoperate with many IPsec implementations, - including earlier versions of Linux FreeS/WAN itself.</P> -<P>In a few cases, there are some complications. See our<A href="interop.html#oldswan"> - interoperation</A> document for details.</P> -<H3><A name="faq.bandwidth">Is there a limit on throughput?</A></H3> -<P>There is no hard limit, but see below.</P> -<H3><A name="faq.number">Is there a limit on number of tunnels?</A></H3> -<P>There is no hard limit, but see next question.</P> -<H3><A name="faq.speed">Is a ... fast enough to handle FreeS/WAN with my - loads?</A></H3> -<P>A quick summary:</P> -<DL> -<DT>Even a limited machine can be useful</DT> -<DD>A 486 can handle a T1, ADSL or cable link, though the machine may be - breathing hard.</DD> -<DT>A mid-range PC (say 800 MHz with good network cards) can do a lot of - IPsec</DT> -<DD>With up to roughly 50 tunnels and aggregate bandwidth of 20 Megabits - per second, it willl have cycles left over for other tasks.</DD> -<DT>There are limits</DT> -<DD>Even a high end CPU will not come close to handling a fully loaded - 100 Mbit/second Ethernet link. -<P>Beyond about 50 tunnels it needs careful management.</P> -</DD> -</DL> -<P>See our<A href="performance.html"> FreeS/WAN performance</A> document - for details.</P> -<H2><A name="work_on">Will FreeS/WAN work on ... ?</A></H2> -<H3><A name="versions">Will FreeS/WAN run on my version of Linux?</A></H3> -<P>We build and test on Redhat distributions, but FreeS/WAN runs just - fine on several other distributions, sometimes with minor fiddles to - adapt to the local environment. Details are in our<A href="compat.html#otherdist"> - compatibility</A> document. Also, some distributions or products come - with<A href="intro.html#products"> FreeS/WAN included</A>.</P> -<H3><A name="nonIntel.faq">Will FreeS/WAN run on non-Intel CPUs?</A></H3> -<P>FreeS/WAN is<STRONG> intended to run on all CPUs Linux supports</STRONG> -. We know of it being used in production on x86, ARM, Alpha and MIPS. It - has also had successful tests on PPC and SPARC, though we don't know of - actual use there. Details are in our<A href="compat.html#CPUs"> - compatibility</A> document.</P> -<H3><A name="multi.faq">Will FreeS/WAN run on multiprocessors?</A></H3> -<P>FreeS/WAN is designed to work on any SMP architecture Linux supports, - and has been tested successfully on at least dual processor Intel - architecture machines. Details are in our<A href="compat.html#multiprocessor"> - compatibility</A> document.</P> -<H3><A name="k.old">Will FreeS/WAN work on an older kernel?</A></H3> -<P>It might, but we strongly recommend using a recent 2.2 or 2.4 series - kernel. Sometimes the newer versions include security fixes which can - be quite important on a gateway.</P> -<P>Also, we use recent kernels for development and testing, so those are - better tested and, if you do encounter a problem, more easily - supported. If something breaks applying recent FreeS/WAN patches to an - older kernel, then "update your kernel" is almost certain to be the - first thing we suggest. It may be the only suggestion we have.</P> -<P>The precise kernel versions supported by a particular FreeS/WAN - release are given in the<A href="XX"> README</A> file of that release.</P> -<P>See the following question for more on kernels.</P> -<H3><A name="k.versions">Will FreeS/WAN run on the latest kernel - version?</A></H3> -<P>Sometimes yes, but quite often, no.</P> -<P>Kernel versions supported are given in the<A href="../README"> README</A> - file of each FreeS/WAN release. Typically, they are whatever production - kernels were current at the time of our release (or shortly before; we - might release for kernel<VAR> n</VAR> just as Linus releases<VAR> n+1</VAR> -). Often FreeS/WAN will work on slightly later kernels as well, but of - course this cannot be guaranteed.</P> -<P>For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, - the current kernels at the time. It also worked on 2.4.6, 2.4.7 and - 2.4.8, but 2.4.9 had changes that caused compilation errors if it was - patched with FreeS/WAN 1.91.</P> -<P>When such changes appear, we put a fix in the FreeS/WAN snapshots, - and distribute it with our next release. However, this is not a high - priority for us, and it may take anything from a few days to several - weeks for such a problem to find its way to the top of our kernel - programmer's To-Do list. In the meanwhile, you have two choices:</P> -<UL> -<LI>either stick with a slightly older kernel, even if it is not the - latest and greatest. This is recommended for production systems; new - versions may have new bugs.</LI> -<LI>or fix the problem yourself and send us a patch, via the<A href="mail.html"> - Users mailing list</A>.</LI> -</UL> -<P>We don't even try to keep up with kernel changes outside the main 2.2 - and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox - or the 2.5 series of development kernels. We'd rather work on - developing the FreeS/WAN code than on chasing these moving targets. We - are, however, happy to get patches for problems discovered there.</P> -<P>See also the<A href="install.html#choosek"> Choosing a kernel</A> - section of our installation document.</P> -<H3><A name="interface.faq">Will FreeS/WAN work on unusual network - hardware?</A></H3> -<P>IPsec is designed to work over any network that IP works over, and - FreeS/WAN is intended to work over any network interface hardware that - Linux supports.</P> -<P>If you have working IP on some unusual interface -- perhaps Arcnet, - Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".</P> -<P>That said, practice is sometimes less tractable than theory. Our - testing is done almost entirely on:</P> -<UL> -<LI>10 or 100 Mbit Ethernet</LI> -<LI>ADSL or cable connections, with and without PPPoE</LI> -<LI>IEEE 802.11 wireless LANs (see<A href="#wireless.faq"> below</A>)</LI> -</UL> -<P>If you have some other interface, especially an uncommon one, it is - entirely possible you will get bitten either by a FreeS/WAN bug which - our testing did not turn up, or by a bug in the driver that shows up - only with our loads.</P> -<P>If IP works on your interface and FreeS/WAN doesn't, seek help on the<A -href="mail.html"> mailing lists</A>.</P> -<P>Another FAQ section describes<A href="#pmtu.broken"> MTU problems</A> -. These are a possibility for some interfaces.</P> -<H3><A name="vlan">Will FreeS/WAN work on a VLAN (802.1q) network?</A></H3> -<P> Yes, FreeSwan works fine, though some network drivers have problems - with jumbo sized ethernet frames. If you used interfaces=%defaultroute - you do not need to change anything, but if you specified an interface - (eg eth0) then remember you must change that to reflect the VLAN - interface (eg eth0.2 for VLAN ID 2).</P> -<P> The "eepro100" module is known to be broken, use the e100 driver for - those cards instead (included in 2.4 as 'alternative driver' for the - Intel EtherExpressPro/100.</P> -<P> You do not need to change any MTU setting (those are workarounds - that are only needed for buggy drivers)</P> -<P><EM>This FAQ contributed by Paul Wouters.</EM></P> -<H2><A name="features.faq">Does FreeS/WAN support ...</A></H2> -<P>For a discussion of which parts of the IPsec specifications FreeS/WAN - does and does not implement, see our<A href="compat.html#spec"> - compatibility</A> document.</P> -<P>For information on some often-requested features, see below.</P> -<H3><A name="VPN.faq"></A>Does FreeS/WAN support site-to-site VPN (<A HREF="glossary.html#VPN"> -Virtual Private Network</A>) applications?</H3> -<P>Absolutely. See this FreeS/WAN-FreeS/WAN<A HREF="config.html"> - configuration example</A>. If only one site is using FreeS/WAN, there - may be a relevant HOWTO on our<A HREF="interop.html"> interop page</A>.</P> -<H3><A name="warrior.faq">Does FreeS/WAN support remote users connecting - to a LAN?</A></H3> -<P>Yes. We call the remote users "Road Warriors". Check out our - FreeS/WAN-FreeS/WAN<A HREF="config.html#config.rw"> Road Warrior - Configuration Example</A>.</P> -<P>If your Road Warrior is a Windows or Mac PC, you may need to install - an IPsec implementation on that machine. Our<A HREF="interop.html"> - interop</A> page lists many available brands, and features links to - several HOWTOs.</P> -<H3><A name="road.shared.possible">Does FreeS/WAN support remote users - using shared secret authentication?</A></H3> -<P><STRONG>Yes, but</STRONG> there are severe restrictions, so<STRONG> - we strongly recommend using</STRONG><A href="glossary.html#RSA"><STRONG> - RSA</STRONG></A><STRONG> keys for</STRONG><A href="glossary.html#authentication"> -<STRONG> authentication</STRONG></A><STRONG> instead</STRONG>.</P> -<P>See this<A href="#road.PSK"> FAQ question</A>.</P> -<H3><A name="wireless.faq">Does FreeS/WAN support wireless networks?</A></H3> -<P>Yes, it is a common practice to use IPsec over wireless networks - because their built-in encryption,<A href="glossary.html#WEP"> WEP</A>, - is insecure.</P> -<P>There is some<A href="adv_config.html#wireless.config"> discussion</A> - in our advanced configuration document. See also the<A HREF="http://www.wavesec.org"> - WaveSEC site</A>.</P> -<H3><A name="PKIcert">Does FreeS/WAN support X.509 or other PKI - certificates?</A></H3> -<P>Vanilla FreeS/WAN does not support X.509, but Andreas Steffen and - others have provided a popular, well-supported X.509 patch.</P> -<UL> -<LI><A HREF="http://www.strongsec.com/freeswan">patch</A></LI> -<LI><A HREF="http://www.freeswan.ca">Super FreeS/WAN</A> incorporates - this and other user-contributed patches.</LI> -<LI> Kai Martius'<A HREF="http://www.strongsec.com/freeswan/install.htm"> - X.509 Installation and Configuration Guide</A></LI> -</UL> -<P> Linux FreeS/WAN features<A HREF="quickstart.html"> Opportunistic - Encryption</A>, an alternative Public Key Infrastructure based on - Secure DNS.</P> -<H3><A name="Radius">Does FreeS/WAN support user authentication (Radius, - SecureID, Smart Card...)?</A></H3> -<P>Andreas Steffen's<A HREF="http://www.strongsec.com/freeswan"> X.509 - patch</A> (v. 1.42+) supports Smart Cards. The patch does not ship with - vanilla FreeS/WAN, but will be incorporated into<A HREF="http://www.freeswan.ca/"> - Super FreeS/WAN 2.01+</A>. The patch implements the PCKS#15 - Cryptographic Token Information Format Standard, using the OpenSC - smartcard library functions.</P> -<P>Older news:</P> -<P>A user-supported patch to FreeS/WAN 1.3, for smart card style - authentication, is available on<A HREF="http://alcatraz.webcriminals.com/~bastiaan/ipsec"> - Bastiaan's site</A>. It supports skeyid and ibutton. This patch is not - part of Super FreeS/WAN.</P> -<P>For a while progress on this front was impeded by a lack of standard. - The IETF<A href="http://www.ietf.org/html.charters/ipsra-charter.html"> - working group</A> has now nearly completed its recommended solution to - the problem; meanwhile several vendors have implemented various things.</P> - -<!-- -<p>The <a href="web.html#patch">patches</a> section of our web links document -has links to some user work on this.</p> ---> -<P>Of course, there are various ways to avoid any requirement for user - authentication in IPsec. Consider the situation where road warriors - build IPsec tunnels to your office net and you are considering - requiring user authentication during tunnel negotiation. Alternatives - include:</P> -<UL> -<LI>If you can trust the road warrior machines, then set them up so that - only authorised users can create tunnels. If your road warriors use - laptops, consider the possibility of theft.</LI> -<LI>If the tunnel only provides access to particular servers and you can - trust those servers, then set the servers up to require user - authentication.</LI> -</UL> -<P>If either of those is trustworthy, it is not clear that you need user - authentication in IPsec.</P> -<H3><A name="NATtraversal">Does FreeS/WAN support NAT traversal?</A></H3> -<P>Vanilla FreeS/WAN does not, but thanks to Mathieu Lafon and Arkoon - Network Security, there's a patch to support this.</P> -<UL> -<LI><A HREF="http://open-source.arkoon.net">patch and documentation</A></LI> -<LI><A HREF="http://www.freeswan.ca">Super FreeS/WAN</A> incorporates - this and other user-contributed patches.</LI> -</UL> -<P>The NAT traversal patch has some issues with PSKs, so you may wish to - authenticate with RSA keys, or X.509 (requires a patch which is also - included in Super FreeS/WAN). Doing the latter also has advantages when - dealing with large numbers of clients who may be behind NAT; instead of - having to make an individual Roadwarrior connection for each virtual - IP, you can use the "rightsubnetwithin" parameter to specify a range. - See<A HREF="http://www.strongsec.com/freeswan/install.htm#section_4.4"> - these<VAR> rightsubnetwithin</VAR> instructions</A>.</P> -<H3><A name="virtID">Does FreeS/WAN support assigning a "virtual - identity" to a remote system?</A></H3> -<P>Some IPsec implementations allow you to make the source address on - packets sent by a Road Warrior machine be something other than the - address of its interface to the Internet. This is sometimes described - as assigning a virtual identity to that machine.</P> -<P>FreeS/WAN does not directly support this, but it can be done. See - this<A href="#road.masq"> FAQ question</A>.</P> -<H3><A name="noDES.faq">Does FreeS/WAN support single DES encryption?</A> -</H3> -<P><STRONG>No</STRONG>, single DES is not used either at the<A href="glossary.html#IKE"> - IKE</A> level for negotiating connections or at the<A href="glossary.html#IPsec"> - IPsec</A> level for actually building them.</P> -<P>Single DES is<A href="politics.html#desnotsecure"> insecure</A>. As - we see it, it is more important to deliver real security than to comply - with a standard which has been subverted into allowing use of - inadequate methods. See this<A href="politics.html#weak"> discussion</A> -.</P> -<P>If you want to interoperate with an IPsec implementation which offers - only DES, see our<A href="interop.html#noDES"> interoperation</A> - document.</P> -<H3><A name="AES.faq">Does FreeS/WAN support AES encryption?</A></H3> -<P><A href="glossary.html#AES">AES</A> is a new US government<A href="glossary.html#block"> - block cipher</A> standard to replace the obsolete<A href="glossary.html#DES"> - DES</A>.</P> -<P>At time of writing (March 2002), the FreeS/WAN distribution does not - yet support AES but user-written<A href="web.html#patch"> patches</A> - are available to add it. Our kernel programmer is working on - integrating those patches into the distribution, and there is active - discussion of this on the design mailimg list.</P> -<H3><A name="other.cipher">Does FreeS/WAN support other encryption - algorithms?</A></H3> -<P>Currently<A href="glossary.html#3DES"> triple DES</A> is the only - cipher supported. AES will almost certainly be added (see previous - question), and it is likely that in the process we will also add the - other two AES finalists with open licensing, Twofish and Serpent.</P> -<P>We are extremely reluctant to add other ciphers. This would make both - use and maintenance of FreeS/WAN more complex without providing any - clear benefit. Complexity is emphatically not desirable in a security - product.</P> -<P>Various users have written patches to add other ciphers. We provide<A href="web.html#patch"> - links</A> to these.</P> -<H2><A name="canI">Can I ...</A></H2> -<H3><A name="policy.preconfig">Can I use policy groups along with - explicitly configured connections?</A></H3> -<P>Yes, you can, so long as you pay attention to the selection rule, - which can be summarized "the most specific connection wins". We - describe the rule in our<A HREF="policygroups.html#policy.group.notes"> - policy groups</A> document, and provide a more technical explanation in<A -HREF="manpage.d/ipsec.conf.5.html"> man ipsec.conf</A>.</P> -<P>A good guideline: If you have a regular connection defined in<VAR> - ipsec.conf</VAR>, ensure that a subset of that connection is not listed - in a less restrictive policy group. Otherwise, FreeS/WAN will use the - subset, with its more specific source/destination pair.</P> -<P>Here's an example. Suppose you are the system administrator at - 192.0.2.2. You have this connection in ipsec.conf:<VAR> ipsec.conf</VAR> -:</P> -<PRE>conn net-to-net - left=192.0.2.2 # you are here - right=192.0.2.8 - rightsubnet=192.0.2.96/27 - .... -</PRE> -<P>If you then place a host or net within<VAR> rightsubnet</VAR>, (let's - say 192.0.2.98) in<VAR> private-or-clear</VAR>, you may find that - 192.0.2.2 at times communicates in the clear with 192.0.2.98. That's - consistent with the rule, but may be contrary to your expectations.</P> -<P>On the other hand, it's safe to put a larger subnet in a less - restrictive policy group file. If<VAR> private-or-clear</VAR> contains - 192.0.2.0/24, then the more specific<VAR> net-to-net</VAR> connection - is used for any communication to 192.0.2.96/27. The more general policy - applies only to communication with hosts or subnets in 192.0.2.0/24 - without a more specific policy or connection.</P> -<H3><A name="policy.off">Can I turn off policy groups?</A></H3> -<P>Yes. Use<A HREF="policygroups.html#disable_policygroups"> these - instructions</A>.</P> - -<!-- -<h3><a name="policy.otherinterface">Can I use policy groups - on an interface other than <VAR>%defaultroute</VAR>?</a></h3> - -<p>??<p> ---> -<H3><A name="reload">Can I reload connection info without restarting?</A> -</H3> -<P>Yes, you can do this. Here are the details, in a mailing list message - from Pluto programmer Hugh Redelmeier:</P> -<PRE>| How can I reload config's without restarting all of pluto and klips? I am using -| FreeSWAN -> PGPNet in a medium sized production environment, and would like to be -| able to add new connections ( i am using include config/* ) without dropping current -| SA's. -| -| Can this be done? -| -| If not, are there plans to add this kind of feature? - - ipsec auto --add whatever -This will look in the usual place (/etc/ipsec.conf) for a conn named -whatever and add it. - -If you added new secrets, you need to do - ipsec auto --rereadsecrets -before Pluto needs to know those secrets. - -| I have looked (perhaps not thoroughly enough tho) to see how to do this: - -There may be more bits to look for, depending on what you are trying -to do.</PRE> -<P>Another useful command here is<VAR> ipsec auto --replace <conn_name></VAR> - which re-reads data for a named connection.</P> -<H3><A name="masq.faq">Can I use several masqueraded subnets?</A></H3> -<P>Yes. This is done all the time. See the discussion in our<A href="config.html#route_or_not"> - setup</A> document. The only restriction is that the subnets on the two - ends must not overlap. See the next question.</P> -<P>Here is a mailing list message on the topic. The user incorrectly - thinks you need a 2.4 kernel for this -- actually various people have - been doing it on 2.0 and 2.2 for quite some time -- but he has it right - for 2.4.</P> -<PRE>Subject: Double NAT and freeswan working :) - Date: Sun, 11 Mar 2001 - From: Paul Wouters <paul@xtdnet.nl> - -Just to share my pleasure, and make an entry for people who are searching -the net on how to do this. Here's the very simple solution to have a double -NAT'ed network working with freeswan. (Not sure if this is old news, but I'm -not on the list (too much spam) and I didn't read this in any HOWTO/FAQ/doc -on the freeswan site yet (Sandy, put it in! :) - -10.0.0.0/24 --- 10.0.0.1 a.b.c.d ---- a.b.c.e {internet} ----+ - | -10.0.1.0/24 --- 10.0.1.1 f.g.h.i ---- f.g.h.j {internet} ----+ - -the goal is to have the first network do a VPN to the second one, yet also -have NAT in place for connections not destinated for the other side of the -NAT. Here the two Linux security gateways have one real IP number (cable -modem, dialup, whatever. - -The problem with NAT is you don't want packets from 10.*.*.* to 10.*.*.* -to be NAT'ed. While with Linux 2.2, you can't, with Linux 2.4 you can. - -(This has been tested and works for 2.4.2 with Freeswan snapshot2001mar8b) - -relevant parts of /etc/ipsec.conf: - - left=f.g.h.i - leftsubnet=10.0.1.0/24 - leftnexthop=f.g.h.j - leftfirewall=yes - leftid=@firewall.netone.nl - leftrsasigkey=0x0........ - right=a.b.c.d - rightsubnet=10.0.0.0/24 - rightnexthop=a.b.c.e - rightfirewall=yes - rightid=@firewall.nettwo.nl - rightrsasigkey=0x0...... - # To authorize this connection, but not actually start it, at startup, - # uncomment this. - auto=add - -and now the real trick. Setup the NAT correctly on both sites: - -iptables -t nat -F -iptables -t nat -A POSTROUTING -o eth0 -d \! 10.0.0.0/8 -j MASQUERADE - -This tells the NAT code to only do NAT for packets with destination other then -10.* networks. note the backslash to mask the exclamation mark to protect it -against the shell. - -Happy painting :) - -Paul</PRE> -<H3><A name="dup_route">Can I use subnets masqueraded to the same - addresses?</A></H3> -<P><STRONG>No.</STRONG> The notion that IP addresses are unique is one - of the fundamental principles of the IP protocol. Messing with it is - exceedingly perilous.</P> -<P>Fairly often a situation comes up where a company has several - branches, all using the same<A href="glossary.html#non-routable"> - non-routable addresses</A>, perhaps 192.168.0.0/24. This works fine as - long as those nets are kept distinct. The<A href="glossary.html#masq"> - IP masquerading</A> on their firewalls ensures that packets reaching - the Internet carry the firewall address, not the private address.</P> -<P>This can break down when IPsec enters the picture. FreeS/WAN builds a - tunnel that pokes through both masquerades and delivers packets from<VAR> - leftsubnet</VAR> to<VAR> rightsubnet</VAR> and vice versa. For this to - work, the two subnets<EM> must</EM> be distinct.</P> -<P>There are several solutions to this problem.</P> -<P>Usually, you<STRONG> re-number the subnets</STRONG>. Perhaps the - Vancouver office becomes 192.168.101.0/24, Calgary 192.168.102.0/24 and - so on. FreeS/WAN can happily handle this. With, for example<VAR> - leftsubnet=192.168.101.0/24</VAR> and<VAR> rightsubnet=192.168.102.0/24</VAR> - in a connection description, any machine in Calgary can talk to any - machine in Vancouver. If you want to be more restrictive and use - something like<VAR> leftsubnet=192.168.101.128/25</VAR> and<VAR> - rightsubnet=192.168.102.240/28</VAR> so only certain machines on each - end have access to the tunnel, that's fine too.</P> -<P>You could also<STRONG> split the subnet</STRONG> into smaller ones, - for example using<VAR> 192.168.1.0/25</VAR> in Vancouver and<VAR> - rightsubnet=192.168.0.128/25</VAR> in Calgary.</P> -<P>Alternately, you can just<STRONG> give up routing</STRONG> directly - to machines on the subnets. Omit the<VAR> leftsubnet</VAR> and<VAR> - rightsubnet</VAR> parameters from your connection descriptions. Your - IPsec tunnels will then run between the public interfaces of the two - firewalls. Packets will be masqueraded both before they are put into - tunnels and after they emerge. Your Vancouver client machines will see - only one Calgary machine, the firewall.</P> -<H3><A name="road.masq">Can I assign a road warrior an address on my net - (a virtual identity)?</A></H3> -<P>Often it would be convenient to be able to give a Road Warrior an IP - address which appears to be on the local network. Some IPsec - implementations have support for this, sometimes calling the feature - "virtual identity".</P> -<P>Currently (Sept 2002) FreeS/WAN does not support this, and we have no - definite plans to add it. The difficulty is that is not yet a standard - mechanism for it. There is an Internet Draft for a method of doing it - using<A href="glossary.html#DHCP"> DHCP</A> which looks promising. - FreeS/WAN may support that in a future release.</P> -<P>In the meanwhile, you can do it yourself using the Linux iproute2(8) - facilities. Details are in<A href="http://www.av8n.com/vpn/iproute2.htm"> - this paper</A>.</P> -<P>Another method has also been discussed on the mailing list.:</P> -<UL> -<LI>You can use a variant of the<A href="adv_config.html#extruded.config"> - extruded subnet</A> procedure.</LI> -<LI>You have to avoid having the road warrior's assigned address within - the range you actually use at home base. See previous question.</LI> -<LI>On the other hand, you want the roadwarrior's address to be within - the range that<EM> seems</EM> to be on your network.</LI> -</UL> -<P>For example, you might have:</P> -<DL> -<DT>leftsubnet=a.b.c.0/25</DT> -<DD>head office network</DD> -<DT>rightsubnet=a.b.c.129/32</DT> -<DD>extruded to a road warrior. Note that this is not in a.b.c.0/25</DD> -<DT>a.b.c.0/24</DT> -<DD>whole network, including both the above</DD> -</DL> -<P>You then set up routing so that the office machines use the IPsec - gateway as their route to a.b.c.128/25. The leftsubnet parameter tells - the road warriors to use tunnels to reach a.b.c.0/25, so you should - have two-way communication. Depending or your network and applications, - there may be some additional work to do on DNS or Windows configuration</P> -<H3><A name="road.many">Can I support many road warriors with one - gateway?</A></H3> -<P>Yes. This is easily done, using</P> -<DL> -<DT>either RSA authentication</DT> -<DD>standard in the FreeS/WAN distribution</DD> -<DT>or X.509 certificates</DT> -<DD>requires<A href="#PKIcert"> Super FreeS/WAN or a patch</A>.</DD> -</DL> -<P>In either case, each Road Warrior must have a different key or - certificate.</P> -<P>It is also possible using pre-shared key authentication, though we - don't recommend this; see the<A href="#road.PSK"> next question</A> for - details.</P> -<P>If you expect to have more than a few dozen Road Warriors connecting - simultaneously, you may need a fairly powerful gateway machine. See our - document on<A href="performance.html"> FreeS/WAN performance</A>.</P> -<H3><A name="road.PSK">Can I have many road warriors using shared secret - authentication?</A></H3> -<P><STRONG>Yes, but avoid it if possible</STRONG>.</P> -<P>You can have multiple Road Warriors using shared secret - authentication<STRONG> only if they all use the same secret</STRONG>. - You must also set:</P> -<P></P> -<PRE> uniqueids=no </PRE> -<P>in the connection definition.</P> -<P>Why it's less secure:</P> -<UL> -<LI>If you have many users, it becomes almost certain the secret will - leak</LI> -<LI>The secret becomes quite valuable to an attacker</LI> -<LI>All users authenticate the same way, so the gateway cannot tell them - apart for logging or access control purposes</LI> -<LI>Changing the secret is difficult. You have to securely notify all - users.</LI> -<LI>If you find out the secret has been compromised, you can change it, - but then what? None of your users can connect without the new secret. - How will you notify them all, quickly and securely, without using the - VPN?</LI> -</UL> -<P>This is a designed-in limitation of the<A href="glossary.html#IKE"> - IKE</A> key negotiation protocol, not a problem with our - implementation.</P> -<P><STRONG>We very strongly recommend that you avoid using shared secret - authentication for multiple Road Warriors.</STRONG> Use RSA - authentication instead.</P> -<P>The longer story: When using shared secrets, the protocol requires - that the responding gateway be able to determine which secret to use at - a time when all it knows about the initiator is an IP address. This - works fine if you know the initiator's address in advance and can use - it to look up the appropiriate secret. However, it fails for Road - Warriors since the gateway cannot know their IP addresses in advance.</P> -<P>With RSA signatures (or certificates) the protocol is slightly - different. The initiator provides an identifier early in the exchange - and the responder can use that identifier to look up the correct key or - certificate. See<A href="#road.many"> above</A>.</P> -<H3><A name="QoS">Can I use Quality of Service routing with FreeS/WAN?</A> -</H3> -<P>From project technical lead Henry Spencer:</P> -<PRE>> Do QoS add to FreeS/WAN? -> For example integrating DiffServ and FreeS/WAN? - -With a current version of FreeS/WAN, you will have to add hidetos=no to -the config-setup section of your configuration file. By default, the TOS -field of tunnel packets is zeroed; with hidetos=no, it is copied from the -packet inside. (This is a modest security hole, which is why it is no -longer the default.) - -DiffServ does not interact well with tunneling in general. Ways of -improving this are being studied.</PRE> -<P>Copying the<A href="glossary.html#TOS"> TOS</A> (type of service) - information from the encapsulated packet to the outer header reveals - the TOS information to an eavesdropper. This does not tell him much, - but it might be of use in<A href="glossary.html#traffic"> traffic - analysis</A>. Since we do not have to give it to him, our default is - not to.</P> -<P>Even with the TOS hidden, you can still:</P> -<UL> -<LI>apply QOS rules to the tunneled (ESP) packets; for example, by - giving ESP packets a certain priority.</LI> -<LI>apply QOS rules to the packets as they enter or exit the tunnel via - an IPsec virtual interface (eg.<VAR> ipsec0</VAR>).</LI> -</UL> -<P>See<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5)</A> for more - on the<VAR> hidetos=</VAR> parameter.</P> -<H3><A name="deadtunnel">Can I recognise dead tunnels and shut them - down?</A></H3> -<P>There is no general mechanism to do this is in the IPsec protocols.</P> -<P>From time to time, there is discussion on the IETF Working Group<A href="mail.html#ietf"> - mailing list</A> of adding a "keep-alive" mechanism (which some say - should be called "make-dead"), but it is a fairly complex problem and - no consensus has been reached on whether or how it should be done.</P> -<P>The protocol does have optional<A href="#ignore"> delete-SA</A> - messages which one side can send when it closes a connection in hopes - this will cause the other side to do the same. FreeS/WAN does not - currently support these. In any case, they would not solve the problem - since:</P> -<UL> -<LI>a gateway that crashes or hangs would not send the messages</LI> -<LI>the sender is not required to send them</LI> -<LI>they are not authenticated, so any receiver that trusts them leaves - itself open to a<A href="glossary.html#DOS"> denial of service</A> - attack</LI> -<LI>the receiver is not required to do anything about them</LI> -<LI>the receiver cannot acknowledge them; the protocol provides no - mechanism for that</LI> -<LI>since they are not acknowledged, the sender cannot rely on them</LI> -</UL> -<P>However, connections do have limited lifetimes and you can control - how many attempts your gateway makes to rekey before giving up. For - example, you can set:</P> -<PRE>conn default - keyingtries=3 - keylife=30m</PRE> -<P>With these settings old connections will be cleaned up. Within 30 - minutes of the other end dying, rekeying will be attempted. If it - succeeds, the new connection replaces the old one. If it fails, no new - connection is created. Either way, the old connection is taken down - when its lifetime expires.</P> -<P>Here is a mailing list message on the topic from FreeS/WAN tech - support person Claudia Schmeing:</P> -<PRE>You ask how to determine whether a tunnel is redundant: - -> Can anybody explain the best way to determine this. Esp when a RW has -> disconnected? I thought 'ipsec auto --status' might be one way. - -If a tunnel goes down from one end, Linux FreeS/WAN on the -other end has no way of knowing this until it attempts to rekey. -Once it tries to rekey and fails, it will 'know' that the tunnel is -down. - -Because it doesn't have a way of knowing the state until this point, -it will also not be able to tell you the state via ipsec auto --status. - -> However, comparing output from a working tunnel with that of one that -> was closed -> did not show clearly show tunnel status. - -If your tunnel is down but not 'unrouted' (see man ipsec_auto), you -should not be able to ping the opposite side of the tunnel. You can -use this as an indicator of tunnel status. - -On a related note, you may be interested to know that as of 1.7, -redundant tunnels caused by RW disconnections are likely to be -less of a pain. From doc/CHANGES: - - There is a new configuration parameter, uniqueids, to control a new Pluto - option: when a new connection is negotiated with the same ID as an old - one, the old one is deleted immediately. This should help eliminate - dangling Road Warrior connections when the same Road Warrior reconnects. - It thus requires that IDs not be shared by hosts (a previously legal but - probably useless capability). NOTE WELL: the sample ipsec.conf now has - uniqueids=yes in its config-setup section. - - -Cheers, - -Claudia</PRE> -<H3><A name="demanddial">Can I build IPsec tunnels over a demand-dialed - link?</A></H3> -<P>This is possible, but not easy. FreeS/WAN technical lead Henry - Spencer wrote:</P> -<PRE>> 5. If the ISDN link goes down in between and is reestablished, the SAs -> are still up but the eroute are deleted and the IPsec interface shows -> garbage (with ifconfig) -> 6. Only restarting IPsec will bring the VPN back online. - -This one is awkward to solve. If the real interface that the IPsec -interface is mounted on goes down, it takes most of the IPsec machinery -down with it, and a restart is the only good way to recover. - -The only really clean fix, right now, is to split the machines in two: - -1. A minimal machine serves as the network router, and only it is aware -that the link goes up and down. - -2. The IPsec is done on a separate gateway machine, which thinks it has -a permanent network connection, via the router. - -This is clumsy but it does work. Trying to do both functions within a -single machine is tricky. There is a software package (diald) which will -give the illusion of a permanent connection for demand-dialed modem -connections; I don't know whether it's usable for ISDN, or whether it can -be made to cooperate properly with FreeS/WAN. - -Doing a restart each time the interface comes up *does* work, although it -is a bit painful. I did that with PPP when I was running on a modem link; -it wasn't hard to arrange the PPP scripts to bring IPsec up and down at -the right times. (I'd meant to investigate diald but never found time.) - -In principle you don't need to do a complete restart on reconnect, but you -do have to rebuild some things, and we have no nice clean way of doing -only the necessary parts.</PRE> -<P>In the same thread, one user commented:</P> -<PRE>Subject: Re: linux-ipsec: IPsec and Dial Up Connections - Date: Wed, 22 Nov 2000 - From: Andy Bradford <andyb@calderasystems.com> - -On Wed, 22 Nov 2000 19:47:11 +0100, Philip Reetz wrote: - -> Are there any ideas what might be the cause of the problem and any way -> to work around it. -> Any help is highly appreciated. - -On my laptop, when using ppp there is a ip-up script in /etc/ppp that -will be executed each time that the ppp interface is brought up. -Likewise there is an ip-down script that is called when it is taken -down. You might consider custimzing those to stop and start FreeS/WAN -with each connection. I believe that ISDN uses the same files, though -I could be wrong---there should be something similar though.</PRE> -<H3><A name="GRE">Can I build GRE, L2TP or PPTP tunnels over IPsec?</A></H3> -<P>Yes. Normally this is not necessary, but it is useful in a few - special cases. For example, if you must route non-IP packets such as - IPX, you will need to use a tunneling protocol that can route these - packets. IPsec can be layered around it for extra security. Another - example: you can provide failover protection for high availability (HA) - environments by combining IPsec with other tools. Ken Bantoft describes - one such setup in<A HREF="http://www.freeswan.ca/docs/HA"> Using - FreeS/WAN with Linux-HA, GRE, OSPF and BGP for enterprise grade VPN - solutions</A>.</P> -<P>GRE over IPsec is covered as part of<A HREF="http://www.freeswan.ca/docs/HA"> - that document</A>.<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/07/msg00209.html"> - Here are links</A> to other GRE resources. Jacco de Leuw has created<A HREF="http://www.jacco2.dds.nl/networking/"> - this page on L2TP over IPsec</A> with instructions for FreeS/WAN and - several other brands of IPsec software.</P> -<P>Please let us know of other useful links via the<A HREF="mail.html"> - mailing lists</A>.</P> -<H3><A name="NetBIOS">... use Network Neighborhood (Samba, NetBIOS) over - IPsec?</A></H3> -<P>Your local PC needs to know how to translate NetBIOS names to IP - addresses. It may do this either via a local LMHOSTS file, or using a - local or remote WINS server. The WINS server is preferable since it - provides a centralized source of the information to the entire network. - To use a WINS server over the<A HREF="glossary.html#VPN"> VPN</A> (or - any IP-based network), you must enable "NetBIOS over TCP".</P> -<P><A HREF="http://www.samba.org">Samba</A> can emulate a WINS server on - Linux.</P> -<P> See also several discussions in our<A HREF="http://lists.freeswan.org/pipermail/users/2002-September/thread.html"> - September 2002 Users archives</A></P> -<H2><A name="setup.faq">Life's little mysteries</A></H2> -<P>FreeS/WAN is a fairly complex product. (Neither the networks it runs - on nor the protocols it uses are simple, so it could hardly be - otherwise.) It therefore sometimes exhibits behaviour which can be - somewhat confusing, or has problems which are not easy to diagnose. - This section tries to explain those problems.</P> -<P>Setup and configuration of FreeS/WAN are covered in other - documentation sections:</P> -<UL> -<LI><A href="quickstart.html">basic setup and configuration</A></LI> -<LI><A href="adv_config.html">advanced configuration</A></LI> -<LI><A href="trouble.html">Troubleshooting</A></LI> -</UL> -<P>However, we also list some of the commonest problems here.</P> -<H3><A name="cantping">I cannot ping ....</A></H3> -<P>This question is dealt with in the advanced configuration section - under the heading<A href="adv_config.html#multitunnel"> multiple - tunnels</A>.</P> -<P>The standard subnet-to-subnet tunnel protects traffic<STRONG> only - between the subnets</STRONG>. To test it, you must use pings that go - from one subnet to the other.</P> -<P>For example, suppose you have:</P> -<PRE> subnet a.b.c.0/24 - | - eth1 = a.b.c.1 - gate1 - eth0 = 192.0.2.8 - | - - ~ internet ~ - - | - eth0 = 192.0.2.11 - gate2 - eth1 = x.y.z.1 - | - subnet x.y.z.0/24</PRE> -<P>and the connection description:</P> -<PRE>conn abc-xyz - left=192.0.2.8 - leftsubnet=a.b.c.0/24 - right=192.0.2.11 - rightsubnet=x.y.z.0/24</PRE> -<P>You can test this connection description only by sending a ping that - will actually go through the tunnel. Assuming you have machines at - addresses a.b.c.2 and x.y.z.2, pings you might consider trying are:</P> -<DL> -<DT>ping from x.y.z.2 to a.b.c.2 or vice versa</DT> -<DD>Succeeds if tunnel is working. This is the<STRONG> only valid test - of the tunnel</STRONG>.</DD> -<DT>ping from gate2 to a.b.c.2 or vice versa</DT> -<DD><STRONG>Does not use tunnel</STRONG>. gate2 is not on protected - subnet.</DD> -<DT>ping from gate1 to x.y.z.2 or vice versa</DT> -<DD><STRONG>Does not use tunnel</STRONG>. gate1 is not on protected - subnet.</DD> -<DT>ping from gate1 to gate2 or vice versa</DT> -<DD><STRONG>Does not use tunnel</STRONG>. Neither gate is on a protected - subnet.</DD> -</DL> -<P>Only the first of these is a useful test of this tunnel. The others - do not use the tunnel. Depending on other details of your setup and - routing, they:</P> -<UL> -<LI>either fail, telling you nothing about the tunnel</LI> -<LI>or succeed, telling you nothing about the tunnel since these packets - use some other route</LI> -</UL> -<P>In some cases, you may be able to get around this. For the example - network above, you could use:</P> -<PRE> ping -I a.b.c.1 x.y.z.1</PRE> -<P>Both the adresses given are within protected subnets, so this should - go through the tunnel.</P> -<P>If required, you can build additional tunnels so that all the - machines involved can talk to all the others. See<A href="adv_config.html#multitunnel"> - multiple tunnels</A> in the advanced configuration document for - details.</P> -<H3><A name="forever">It takes forever to ...</A></H3> -<P>Users fairly often report various problems involving long delays, - sometimes on tunnel setup and sometimes on operations done through the - tunnel, occasionally on simple things like ping or more often on more - complex operations like doing NFS or Samba through the tunnel.</P> -<P>Almost always, these turn out to involve failure of a DNS lookup. The - timeouts waiting for DNS are typically set long so that you won't time - out when a query involves multiple lookups or long paths. Genuine - failures therefore produce long delays before they are detected.</P> -<P>A mailing list message from project technical lead Henry Spencer:</P> -<PRE>> ... when i run /etc/rc.d/init.d/ipsec start, i get: -> ipsec_setup: Starting FreeS/WAN IPsec 1.5... -> and it just sits there, doesn't give back my bash prompt. - -Almost certainly, the problem is that you're using DNS names in your -ipsec.conf, but DNS lookups are not working for some reason. You will -get your prompt back... eventually. But the DNS timeouts are long. -Doing something about this is on our list, but it is not easy.</PRE> -<P>In the meanwhile, we recommend that connection descriptions in<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A> use numeric IP addresses rather than names which will - require a DNS lookup.</P> -<P>Names that do not require a lookup are fine. For example:</P> -<UL> -<LI>a road warrior might use the identity<VAR> - rightid=@lancelot.example.org</VAR></LI> -<LI>the gateway might use<VAR> leftid=@camelot.example.org</VAR></LI> -</UL> -<P>These are fine. The @ sign prevents any DNS lookup. However, do not - attempt to give the gateway address as<VAR> left=camelot.example.org</VAR> -. That requires a lookup.</P> -<P>A post from one user after solving a problem with long delays:</P> -<PRE>Subject: Final Answer to Delay!!! - Date: Mon, 19 Feb 2001 - From: "Felippe Solutions" <felippe@solutionstecnologia.com.br> - -Sorry people, but seems like the Delay problem had nothing to do with -freeswan. - -The problem was DNS as some people sad from the beginning, but not the way -they thought it was happening. Samba, ssh, telnet and other apps try to -reverse lookup addresses when you use IP numbers (Stupid that ahh). - -I could ping very fast because I always ping with "-n" option, but I don't -know the option on the other apps to stop reverse addressing so I don't use -it.</PRE> -<P>This post is fairly typical. These problems are often tricky and - frustrating to diagnose, and most turn out to be DNS-related.</P> -<P>One suggestion for diagnosis: test with both names and addresses if - possible. For example, try all of:</P> -<UL> -<LI>ping<VAR> address</VAR></LI> -<LI>ping -n<VAR> address</VAR></LI> -<LI>ping<VAR> name</VAR></LI> -</UL> -<P>If these behave differently, the problem must be DNS-related since - the three commands do exactly the same thing except for DNS lookups.</P> -<H3><A name="route">I send packets to the tunnel with route(8) but they - vanish</A></H3> -<P>IPsec connections are designed to carry only packets travelling - between pre-defined connection endpoints. As project technical lead - Henry Spencer put it:</P> -<BLOCKQUOTE> IPsec tunnels are not just virtual wires; they are virtual - wires with built-in access controls. Negotiation of an IPsec tunnel - includes negotiation of access rights for it, which don't include - packets to/from other IP addresses. (The protocols themselves are quite - inflexible about this, so there are limits to what we can do about it.)</BLOCKQUOTE> -<P>For fairly obvious security reasons, and to comply with the IPsec - RFCs,<A href="glossary.html#KLIPS"> KLIPS</A> drops any packets it - receives that are not allowed on the tunnels currently defined. So if - you send it packets with<VAR> route(8)</VAR>, and suitable tunnels are - not defined, the packets vanish. Whether this is reported in the logs - depends on the setting of<VAR> klipsdebug</VAR> in your<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A> file.</P> -<P>To rescue vanishing packets, you must ensure that suitable tunnels - for them exist, by editing the connection descriptions in<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A>. For example, supposing you have a simple setup:</P> -<PRE> leftsubnet -- leftgateway === internet === roadwarrior</PRE> -<P>If you want to give the roadwarrior access to some resource that is - located behind the left gateway but is not in the currently defined - left subnet, then the usual procedure is to define an additional tunnel - for those packets by creating a new connection description.</P> -<P>In some cases, it may be easier to alter an existing connection - description, enlarging the definition of<VAR> leftsubnet</VAR>. For - example, instead of two connection descriptions with 192.168.8.0/24 and - 192.168.9.0/24 as their<VAR> leftsubnet</VAR> parameters, you can use a - single description with 192.168.8.0/23.</P> -<P>If you have multiple endpoints on each side, you need to ensure that - there is a route for each pair of endpoints. See this<A href="adv_config.html#multitunnel"> - example</A>.</P> -<H3><A name="down_route">When a tunnel goes down, packets vanish</A></H3> -<P>This is a special case of the vanishing packet problem described in - the previous question. Whenever KLIPS sees packets for which it does - not have a tunnel, it drops them.</P> -<P>When a tunnel goes away, either because negotiations with the other - gateway failed or because you gave an<VAR> ipsec auto --down</VAR> - command, the route to its other end is left pointing into KLIPS, and - KLIPS will drop packets it has no tunnel for.</P> -<P>This is a documented design decision, not a bug. FreeS/WAN must not - automatically adjust things to send packets via another route. The - other route might be insecure.</P> -<P>Of course, re-routing may be necessary in many cases. In those cases, - you have to do it manually or via scripts. We provide the<VAR> ipsec - auto --unroute</VAR> command for these cases.</P> -<P>From<A href="manpage.d/ipsec_auto.8.html"> ipsec_auto(8)</A>:</P> -<BLOCKQUOTE> Normally, pluto establishes a route to the destination - specified for a connection as part of the --up operation. However, the - route and only the route can be established with the --route operation. - Until and unless an actual connection is established, this discards any - packets sent there, which may be preferable to having them sent - elsewhere based on a more general route (e.g., a default route).</BLOCKQUOTE><BLOCKQUOTE> - Normally, pluto's route to a destination remains in place when a --down - operation is used to take the connection down (or if connection setup, - or later automatic rekeying, fails). This permits establishing a new - connection (perhaps using a different specification; the route is - altered as necessary) without having a ``window'' in which packets - might go elsewhere based on a more general route. Such a route can be - removed using the --unroute operation (and is implicitly removed by - --delete).</BLOCKQUOTE> -<P>See also this mailing list<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/11/msg00523.html"> - message</A>.</P> -<H3><A name="firewall_ate">The firewall ate my packets!</A></H3> -<P>If firewalls filter out:</P> -<UL> -<LI>either the UDP port 500 packets used in IKE negotiations</LI> -<LI>or the ESP and AH (protocols 50 and 51) packets used to implement - the IPsec tunnel</LI> -</UL> -<P>then IPsec cannot work. The first thing to check if packets seem to - be vanishing is the firewall rules on the two gateway machines and any - other machines along the path that you have access to.</P> -<P>For details, see our document on<A href="firewall.html"> firewalls</A> -.</P> -<P>Some advice from technical lead Henry Spencer on diagnosing such - problems:</P> -<PRE>> > Packets vanishing between the hardware interface and the ipsecN interface -> > is usually the result of firewalls not being configured to let them in... -> -> Thanks for the suggestion. If only it were that simple! My ipchains startup -> script does take care of that, but just in case I manually inserted rules -> accepting everything from london on dublin. No difference. - -The other thing to check is whether the "RX packets dropped" count on the -ipsecN interface (run "ifconfig ipsecN", for N=1 or whatever, to see the -counts) is rising. If so, then there's some sort of configuration mismatch -between the two ends, and IPsec itself is rejecting them. If none of the -ipsecN counts is rising, then the packets are never reaching the IPsec -machinery, and the problem is almost certainly in firewalls etc.</PRE> -<H3><A name="dropconn">Dropped connections</A></H3> -<P>Networks being what they are, IPsec connections can be broken for any - number of reasons, ranging from hardware failures to various software - problems such as the path MTU problems discussed<A href="#pmtu.broken"> - elsewhere in the FAQ</A>. Fortunately, various diagnostic tools exist - that help you sort out many of the possible problems.</P> -<P>There is one situation, however, where FreeS/WAN (using default - settings) may destroy a connection for no readily apparent reason. This - occurs when things are<STRONG> misconfigured</STRONG> so that<STRONG> - two tunnels</STRONG> from the same gateway expect<STRONG> the same - subnet on the far end</STRONG>.</P> -<P>In this situation, the first tunnel comes up fine and works until the - second is established. At that point, because of the way we track - connections internally, the first tunnel ceases to exist as far as this - gateway is concerned. Of course the far end does not know that, and a - storm of error messages appears on both systems as it tries to use the - tunnel.</P> -<P>If the far end gives up, goes back to square one and negotiates a new - tunnel, then that wipes out the second tunnel and ...</P> -<P>The solution is simple.<STRONG> Do not build multiple conn - descriptions with the same remote subnet</STRONG>.</P> -<P>This is actually intended to be a feature, rather than a bug. - Consider the situation where a single remote system goes down, then - comes back up and reconnects to the gateway. It is useful to have the - gateway tear down the old tunnel and recover resources when the - reconnection is made. It recognises that situation by checking the - remote subnet for each tunnel it builds and discarding duplicates. This - works fine as long as you don't configure multiple tunnels with the - same remote subnet.</P> -<P>If this behaviour is inconvenient for you, you can disable it by - setting<VAR> uniqueids=no</VAR> in<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A>.</P> -<H3><A name="defaultroutegone">Disappearing %defaultroute</A></H3> -<P>When an underlying connection (eg. ppp) goes down, FreeS/WAN will not - recover properly without a little help. Here are the symptoms that - FreeS/WAN user Michael Carmody noticed:</P> -<PRE> -> After about 24 hours the freeswan connection takes over the default route. -> -> i.e instead of deafult gateway pointing to the router via eth0, it becomes a -> pointer to the router via ipsec0. - -> All internet access is then lost as all replies (and not just the link I -> wanted) are routed out ipsec0 and the router doesn't respond to the ipsec -> traffic. -</PRE> -<P>If you're using a FreeS/WAN 2.x/KLIPS system, simply re-attach the - IPsec virtual interface with<EM> ipsec tnconfig</EM> command such as:</P> -<PRE> ipsec tnconfig --attach --virtual ipsec0 --physical ppp0</PRE> -<P>In your command, name the physical and virtual interfaces as they - appear paired on your system during regular uptime. For a system with - several physical/virtual interface pairs on flaky links, you'll need - more than one such command. If you're using FreeS/WAN 1.x, you must - restart FreeS/WAN, which is more time consuming.</P> -<P><A href="http://lists.freeswan.org/pipermail/design/2002-July/003070.html"> - Here</A> is a script which can help to automate the process of - FreeS/WAN restart at need. It could easily be adapted to use tnconfig - instead.</P> -<H3><A name="tcpdump.faq">TCPdump on the gateway shows strange things</A> -</H3> - As another user pointed out, keeping the connect -<P>Attempting to look at IPsec packets by running monitoring tools on - the IPsec gateway machine can produce silly results. That machine is - mangling the packets for IPsec, and possibly for firewall or NAT - purposes as well. If the internals of the machine's IP stack are not - what the monitoring tool expects, then the tool can misinterpret them - and produce nonsense output.</P> -<P>See our<A href="testing.html#tcpdump.test"> testing</A> document for - more detail.</P> -<H3><A name="no_trace">Traceroute does not show anything between the - gateways</A></H3> -<P>As far as traceroute can see, the two gateways are one hop apart; the - data packet goes directly from one to the other through the tunnel. Of - course the outer packets that implement the tunnel pass through - whatever lies between the gateways, but those packets are built and - dismantled by the gateways. Traceroute does not see them and cannot - report anything about their path.</P> -<P>Here is a mailing list message with more detail.</P> -<PRE>Date: Mon, 14 May 2001 -To: linux-ipsec@freeswan.org -From: "John S. Denker" <jsd@research.att.com< -Subject: Re: traceroute: one virtual hop - -At 02:20 PM 5/14/01 -0400, Claudia Schmeing wrote: -> ->> > A bonus question: traceroute in subnet to subnet enviroment looks like: ->> > ->> > traceroute to andris.dmz (172.20.24.10), 30 hops max, 38 byte packets ->> > 1 drama (172.20.1.1) 0.716 ms 0.942 ms 0.434 ms ->> > 2 * * * ->> > 3 andris.dmz (172.20.24.10) 73.576 ms 78.858 ms 79.434 ms ->> > ->> > Why aren't there the other hosts which take part in the delivery during -> * * * ? -> ->If there is an ipsec tunnel between GateA and Gate B, this tunnel forms a ->'virtual wire'. When it is tunneled, the original packet becomes an inner ->packet, and new ESP and/or AH headers are added to create an outer packet ->around it. You can see an example of how this is done for AH at ->doc/ipsec.html#AH . For ESP it is similar. -> ->Think about the packet's path from the inner packet's perspective. ->It leaves the subnet, goes into the tunnel, and re-emerges in the second ->subnet. This perspective is also the only one available to the ->'traceroute' command when the IPSec tunnel is up. - -Claudia got this exactly right. Let me just expand on a couple of points: - -*) GateB is exactly one (virtual) hop away from GateA. This is how it -would be if there were a physically private wire from A to B. The -virtually private connection should work the same, and it does. - -*) While the information is in transit from GateA to GateB, the hop count -of the outer header (the "envelope") is being decremented. The hop count -of the inner header (the "contents" of the envelope) is not decremented and -should not be decremented. The hop count of the outer header is not -derived from and should not be derived from the hop count of the inner header. - -Indeed, even if the packets did time out in transit along the tunnel, there -would be no way for traceroute to find out what happened. Just as -information cannot leak _out_ of the tunnel to the outside, information -cannot leak _into_ the tunnel from outside, and this includes ICMP messages -from routers along the path. - -There are some cases where one might wish for information about what is -happening at the IP layer (below the tunnel layer) -- but the protocol -makes no provision for this. This raises all sorts of conceptual issues. -AFAIK nobody has ever cared enough to really figure out what _should_ -happen, let alone implement it and standardize it. - -*) I consider the "* * *" to be a slight bug. One might wish for it to be -replaced by "GateB GateB GateB". It has to do with treating host-to-subnet -traffic different from subnet-to-subnet traffic (and other gory details). -I fervently hope KLIPS2 will make this problem go away. - -*) If you want to ask questions about the link from GateA to GateB at the -IP level (below the tunnel level), you have to ssh to GateA and launch a -traceroute from there.</PRE> -<H2><A name="man4debug">Testing in stages</A></H2> -<P>It is often useful in debugging to test things one at a time:</P> -<UL> -<LI>disable IPsec entirely, for example by turning it off with - chkconfig(8), and make sure routing works</LI> -<LI>Once that works, try a manually keyed connection. This does not - require key negotiation between Pluto and the key daemon on the other - end.</LI> -<LI>Once that works, try automatically keyed connections</LI> -<LI>Once IPsec works, add packet compression</LI> -<LI>Once everything seems to work, try stress tests with large - transfers, many connections, frequent re-keying, ...</LI> -</UL> -<P>FreeS/WAN releases are tested for all of these, so you can be - reasonably certain they<EM> can</EM> do them all. Of course, that does - not mean they<EM> will</EM> on the first try, especially if you have - some unusual configuration.</P> -<P>The rest of this section gives information on diagnosing the problem - when each of the above steps fails.</P> -<H3><A name="nomanual">Manually keyed connections don't work</A></H3> -<P>Suspect one of:</P> -<UL> -<LI>mis-configuration of IPsec system in the /etc/ipsec.conf file -<BR> common errors are incorrect interface or next hop information</LI> -<LI>mis-configuration of manual connection in the /etc/ipsec.conf file</LI> -<LI>routing problems causing IPsec packets to be lost</LI> -<LI>bugs in KLIPS</LI> -<LI>mismatch between the transforms we support and those another IPsec - implementation offers.</LI> -</UL> -<H3><A name="spi_error">One manual connection works, but second one - fails</A></H3> -<P>This is a fairly common problem when attempting to configure multiple - manually keyed connections from a single gateway.</P> -<P>Each connection must be identified by a unique<A href="glossary.html#SPI"> - SPI</A> value. For automatic connections, these values are assigned - automatically. For manual connections, you must set them with<VAR> spi=</VAR> - statements in<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5)</A>.</P> -<P>Each manual connection must have a unique SPI value in the range - 0x100 to 0x999. Two or more with the same value will fail. For details, - see our doc section<A href="adv_config.html#prodman"> Using manual - keying in production</A> and the man page<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A>.</P> -<H3><A name="man_no_auto">Manual connections work, but automatic keying - doesn't</A></H3> -<P>The most common reason for this behaviour is a firewall dropping the - UDP port 500 packets used in key negotiation.</P> -<P>Other possibilities:</P> -<UL> -<LI>mis-configuration of auto connection in the /etc/ipsec.conf file. -<P>One common configuration error is forgetting that you need<VAR> - auto=add</VAR> to load the connection description on the receiving end - so it recognises the connection when the other end asks for it.</P> -</LI> -<LI>error in shared secret in /etc/ipsec.secrets</LI> -<LI>one gateway lacks a route to the other so Pluto's UDP packets are - lost</LI> -<LI>bugs in Pluto</LI> -<LI>incompatibilities between Pluto's<A href="glossary.html#IKE"> IKE</A> - implementation and the IKE at the other end of the tunnel. -<P>Some possibile problems are discussed in out<A href="interop.html#interop.problem"> - interoperation</A> document.</P> -</LI> -</UL> -<H3><A name="nocomp">IPsec works, but connections using compression fail</A> -</H3> -<P>When we first added compression, we saw some problems:</P> -<UL> -<LI>compatibility issues with other implementations. We followed the - RFCs and omitted some extra material that many compression libraries - add by default. Some other implementations left the extras in</LI> -<LI>bugs in assembler compression routines on non-Intel CPUs. The - workaround is to use C code instead of possibly problematic assembler.</LI> -</UL> -<P>We have not seen either problem in some time (at least six months as - I write in March 2002), but if you have some unusual configuration then - you may see them.</P> -<H3><A name="pmtu.broken">Small packets work, but large transfers fail</A> -</H3> -<P>If tests with ping(1) and a small packet size succeed, but tests or - transfers with larger packet sizes fail, suspect problems with packet - fragmentation and perhaps<A href="glossary.html#pathMTU"> path MTU - discovery</A>.</P> -<P>Our<A href="trouble.html#bigpacket"> troubleshooting document</A> - covers these problems. Information on the underlying mechanism is in - our<A href="background.html#MTU.trouble"> background</A> document.</P> -<H3><A name="subsub">Subnet-to-subnet works, but tests from the gateways - don't</A></H3> -<P>This is described under<A href="#cantping"> I cannot ping...</A> - above.</P> -<H2><A name="compile.faq">Compilation problems</A></H2> -<H3><A name="gmp.h_missing">gmp.h: No such file or directory</A></H3> -<P>Pluto needs the GMP (<STRONG>G</STRONG>NU</P> -<P><STRONG>M</STRONG>ulti-<STRONG>P</STRONG>recision) library for the - large integer calculations it uses in<A href="glossary.html#public"> - public key</A> cryptography. This error message indicates a failure to - find the library. You must install it before Pluto will compile.</P> -<P>The GMP library is included in most Linux distributions. Typically, - there are two RPMs, libgmp and libgmp-devel, You need to<EM> install - both</EM>, either from your distribution CDs or from your vendor's web - site.</P> -<P>On Debian, a mailing list message reports that the command to give is<VAR> - apt-get install gmp2</VAR>.</P> -<P>For more information and the latest version, see the<A href="http://www.swox.com/gmp/"> - GMP home page</A>.</P> -<H3><A name="noVM">... virtual memory exhausted</A></H3> -<P>We have had several reports of this message appearing, all on SPARC - Linux. Here is a mailing message on a solution:</P> -<PRE>> ipsec_sha1.c: In function `SHA1Transform': -> ipsec_sha1.c:95: virtual memory exhausted - -I'm seeing exactly the same problem on an Ultra with 256MB ram and 500 -MB swap. Except I am compiling version 1.5 and its Red Hat 6.2. - -I can get around this by using -O instead of -O2 for the optimization -level. So it is probably a bug in the optimizer on the sparc complier. -I'll try and chase this down on the sparc lists.</PRE> -<H2><A name="error">Interpreting error messages</A></H2> -<H3><A name="route-client">route-client (or host) exited with status 7</A> -</H3> -<P>Here is a discussion of this error from FreeS/WAN "listress" (mailing - list tech support person) Claudia Schmeing. The "FAQ on the network - unreachable error" which she refers to is the next question below.</P> -<PRE>> I reached the point where the two boxes (both on dial-up connections, but -> treated as static IPs by getting the IP and editing ipsec.conf after the -> connection is established) to the point where they exchange some info, but I -> get an error like "route-client command exited with status 7 \n internal -> error". -> Where can I find a description of this error? - -In general, if the FAQ doesn't cover it, you can search the mailing list -archives - I like to use -http://www.sandelman.ottawa.on.ca/linux-ipsec/ -but you can see doc/mail.html for different archive formats. - - -Your error comes from the _updown script, which performs some -routing and firewall functions to help Linux FreeS/WAN. More info -is available at doc/firewall.html and man ipsec.conf. Its routing -is integral to the health of Linux FreeS/WAN; it also provides facility -to insert custom firewall rules to be executed when you create or destroy -a connection. - -Yours is, of course, a routing error. You can be fairly sure the routing -machinery is saying "network is unreachable". There's a FAQ on the -"network is unreachable" error, but more information is available now; read on. - -If your _updown script is recent (for example if it shipped with -Linux FreeS/WAN 1.91), you will see another debugging line in your logs -that looks something like this: - -> output: /usr/local/lib/ipsec/_updown: `route add -net 128.174.253.83 -> netmask 255.255.255.255 dev ipsec0 gw 66.92.93.161' failed - -This is, of course, the system route command that exited with status 7, -(ie. failed). Man route for details. Seeing the command typed out yields -more information. If your _updown script is older, you may wish to update -it to show the command explicitly. - -Three parameters fed to the route command: net, netmask and gw [gateway] -are derived from things you've put in ipsec.conf. - -Net and netmask are derived from the peer's IP and mask. In more detail: - -You may see a routing error when routing to a client (ie. subnet), or -to a host (IPSec gateway or freestanding host; a box that does IPSec for -itself). In _updown, the "route-client" section is responsible to set up -the route for IPSec'd (usually, read 'tunneled') packets headed to a -peer subnet. Similarly, route-host routes IPSec'd packets to a peer host -or IPSec gateway. - -When routing to a 'client', net and netmask are ipsec.conf's left- or -rightsubnet (whichever is not local). Similarly, when routing to a -'host' the net is left or right. Host netmask is always /32, indicating a -single machine. - -Gw is nexthop's value. Again, the value in question is left- or rightnexthop, -whichever is local. Where left/right or left-/rightnexthop has the special -value %defaultroute (described in man ipsec.conf), gw will automagically get -the value of the next hop on the default route. - -Q: "What's a nexthop and why do I need one?" - -A: 'nexthop' is a routing kluge; its value is the next hop away - from the machine that's doing IPSec, and toward your IPSec peer. - You need it to get the processed packets out of the local system and - onto the wire. While we often route other packets through the machine - that's now doing IPSec, and are done with it, this does not suffice here. - After packets are processed with IPSec, this machine needs to know where - they go next. Of course using the 'IPSec gateway' as their routing gateway - would cause an infinite loop! [To visualize this, see the packet flow - diagram at doc/firewall.html.] To avoid this, we route packets through - the next hop down their projected path. - -Now that you know the background, consider: -1. Did you test routing between the gateways in the absence of Linux - FreeS/WAN, as recommended? You need to ensure the two machines that - will be running Linux FreeS/WAN can route to one another before trying to - make a secure connection. -2. Is there anything obviously wrong with the sense of your route command? - -Normally, this problem is caused by an incorrect local nexthop parameter. -Check out the use of %defaultroute, described in man ipsec.conf. This is -a simple way to set nexthop for most people. To figure nexthop out by hand, -traceroute in-the-clear to your IPSec peer. Nexthop is the traceroute's -first hop after your IPSec gateway.</PRE> -<H3><A name="unreachable">SIOCADDRT:Network is unreachable</A></H3> -<P>This message is not from FreeS/WAN, but from the Linux IP stack - itself. That stack is seeing packets it has no route for, either - because your routing was broken before FreeS/WAN started or because - FreeS/WAN's changes broke it.</P> -<P>Here is a message from Claudia suggesting ways to diagnose and fix - such problems:</P> -<PRE>You write, -> I have correctly installed freeswan-1.8 on RH7.0 kernel 2.2.17, but when -> I setup a VPN connection with the other machine(RH5.2 Kernel 2.0.36 -> freeswan-1.0, it works well.) it told me that -> "SIOCADDRT:Network is unreachable"! But the network connection is no -> problem. - -Often this error is the result of a misconfiguration. - -Be sure that you can route successfully in the absence of Linux -FreeS/WAN. (You say this is no problem, so proceed to the next step.) - -Use a custom copy of the default updownscript. Do not change the route -commands, but add a diagnostic message revealing the exact text of the -route command. Is there a problem with the sense of the route command -that you can see? If so, then re-examine those ipsec.conf settings -that are being sent to the route command. - -You may wish to use the ipsec auto --route and --unroute commands to -troubleshoot the problem. See man ipsec_auto for details.</PRE> -<P>Since the above message was written, we have modified the updown - script to provide a better diagnostic for this problem. Check<VAR> - /var/log/messages</VAR>.</P> -<P>See also the FAQ question<A href="#route-client"> route-client (or - host) exited with status 7</A>.</P> -<H3><A name="modprobe">ipsec_setup: modprobe: Can't locate module ipsec</A> -</H3> -<H3><A name="noKLIPS">ipsec_setup: Fatal error, kernel appears to lack - KLIPS</A></H3> -<P>These messages indicate an installation failure. The kernel you are - running does not contain the<A href="glossary.html#KLIPS"> KLIPS - (kernel IPsec)</A> code.</P> -<P>Note that the "modprobe: Can't locate module ipsec" message appears - even if you are not using modules. If there is no KLIPS in your kernel, - FreeS/WAN tries to load it as a module. If that fails, you get this - message.</P> -<P>Commands you can quickly try are:</P> -<DL> -<DT><VAR>uname -a</VAR></DT> -<DD>to get details, including compilation date and time, of the - currently running kernel</DD> -<DT><VAR>ls /</VAR></DT> -<DT><VAR>ls /boot</VAR></DT> -<DD>to ensure a new kernel is where it should be. If kernel compilation - puts it in<VAR> /</VAR> but<VAR> lilo</VAR> wants it in<VAR> /boot</VAR> -, then you should uncomment the<VAR> INSTALL_PATH=/boot</VAR> line in - the kernel<VAR> Makefile</VAR>.</DD> -<DT><VAR>more /etc/lilo.conf</VAR></DT> -<DD>to see that<VAR> lilo</VAR> has correct information</DD> -<DT><VAR>lilo</VAR></DT> -<DD>to ensure that information in<VAR> /etc/lilo.conf</VAR> has been - transferred to the boot sector</DD> -</DL> -<P>If those don't find the problem, you have to go back and check - through the<A href="install.html"> install</A> procedure to see what - was missed.</P> -<P>Here is one of Claudia's messages on the topic:</P> -<PRE>> I tried to install freeswan 1.8 on my mandrake 7.2 test box. ... - -> It does show version and some output for whack. - -Yes, because the Pluto (daemon) part of ipsec is installed correctly, but -as we see below the kernel portion is not. - -> However, I get the following from /var/log/messages: -> -> Mar 11 22:11:55 pavillion ipsec_setup: Starting FreeS/WAN IPsec 1.8... -> Mar 11 22:12:02 pavillion ipsec_setup: modprobe: Can't locate module ipsec -> Mar 11 22:12:02 pavillion ipsec_setup: Fatal error, kernel appears to lack -> KLIPS. - -This is your problem. You have not successfully installed a kernel with -IPSec machinery in it. - -Did you build Linux FreeS/WAN as a module? If so, you need to ensure that -your new module has been installed in the directory where your kernel -loader normally finds your modules. If not, you need to ensure -that the new IPSec-enabled kernel is being loaded correctly. - -See also doc/install.html, and INSTALL in the distro.</PRE> -<H3><A name="noDNS">ipsec_setup: ... failure to fetch key for ... from - DNS</A></H3> -<P>Quoting Henry:</P> -<PRE>Note that by default, FreeS/WAN is now set up to - (a) authenticate with RSA keys, and - (b) fetch the public key of the far end from DNS. -Explicit attention to ipsec.conf will be needed if you want -to do something different.</PRE> -<P>and Claudia, responding to the same user:</P> -<PRE>You write, - -> My current setup in ipsec.conf is leftrsasigkey=%dns I have -> commented this and authby=rsasig out. I am able to get ipsec running, -> but what I find is that the documentation only specifies for %dns are -> there any other values that can be placed in this variable other than -> %dns and the key? I am also assuming that this is where I would place -> my public key for the left and right side as well is this correct? - -Valid values for authby= are rsasig and secret, which entail authentication -by RSA signature or by shared secret, respectively. Because you have -commented authby=rsasig out, you are using the default value of authby=secret. - -When using RSA signatures, there are two ways to get the public key for the -IPSec peer: either copy it directly into *rsasigkey= in ipsec.conf, or -fetch it from dns. The magic value %dns for *rsasigkey parameters says to -try to fetch the peer's key from dns. - -For any parameters, you may find their significance and special values in -man ipsec.conf. If you are setting up keys or secrets, be sure also to -reference man ipsec.secrets.</PRE> -<H3><A name="dup_address">ipsec_setup: ... interfaces ... and ... share - address ...</A></H3> -<P>This is a fatal error. FreeS/WAN cannot cope with two or more - interfaces using the same IP address. You must re-configure to avoid - this.</P> -<P>A mailing list message on the topic from Pluto developer Hugh - Redelmeier:</P> -<PRE>| I'm trying to get freeswan working between two machine where one has a ppp -| interface. -| I've already suceeded with two machines with ethernet ports but the ppp -| interface is causing me problems. -| basically when I run ipsec start i get -| ipsec_setup: Starting FreeS/WAN IPsec 1.7... -| ipsec_setup: 003 IP interfaces ppp1 and ppp0 share address 192.168.0.10! -| ipsec_setup: 003 IP interfaces ppp1 and ppp2 share address 192.168.0.10! -| ipsec_setup: 003 IP interfaces ppp0 and ppp2 share address 192.168.0.10! -| ipsec_setup: 003 no public interfaces found -| -| followed by lots of cannot work out interface for connection messages -| -| now I can specify the interface in ipsec.conf to be ppp0 , but this does -| not affect the above behaviour. A quick look in server.c indicates that the -| interfaces value is not used but some sort of raw detect happens. -| -| I guess I could prevent the formation of the extra ppp interfaces or -| allocate them different ip but I'd rather not. if at all possible. Any -| suggestions please. - -Pluto won't touch an interface that shares an IP address with another. -This will eventually change, but it probably won't happen soon. - -For now, you will have to give the ppp1 and ppp2 different addresses.</PRE> -<H3><A name="kflags">ipsec_setup: Cannot adjust kernel flags</A></H3> -<P>A mailing list message form technical lead Henry Spencer:</P> -<PRE>> When FreeS/WAN IPsec 1.7 is starting on my 2.0.38 Linux kernel the following -> error message is generated: -> ipsec_setup: Cannot adjust kernel flags, no /proc/sys/net/ipsec directory! -> What is supposed to create this directory and how can I fix this problem? - -I think that directory is a 2.2ism, although I'm not certain (I don't have -a 2.0.xx system handy any more for testing). Without it, some of the -ipsec.conf config-setup flags won't work, but otherwise things should -function. </PRE> -<P>You also need to enable the<VAR> /proc</VAR> filesystem in your - kernel configuration for these operations to work.</P> -<H3><A name="message_num">Message numbers (MI3, QR1, et cetera) in Pluto - messages</A></H3> -<P>Pluto messages often indicate where Pluto is in the IKE protocols. - The letters indicate<STRONG> M</STRONG>ain mode or<STRONG> Q</STRONG> -uick mode and<STRONG> I</STRONG>nitiator or<STRONG> R</STRONG>esponder. - The numerals are message sequence numbers. For more detail, see our<A href="ipsec.html#sequence"> - IPsec section</A>.</P> -<H3><A name="conn_name">Connection names in Pluto error messages</A></H3> -<P>From Pluto programmer Hugh Redelmeier:</P> -<PRE>| Jan 17 16:21:10 remus Pluto[13631]: "jumble" #1: responding to Main Mode from Road Warrior 130.205.82.46 -| Jan 17 16:21:11 remus Pluto[13631]: "jumble" #1: no suitable connection for peer @banshee.wittsend.com -| -| The connection "jumble" has nothing to do with the incoming -| connection requests, which were meant for the connection "banshee". - -You are right. The message tells you which Connection Pluto is -currently using, which need not be the right one. It need not be the -right one now for the negotiation to eventually succeed! This is -described in ipsec_pluto(8) in the section "Road Warrior Support". - -There are two times when Pluto will consider switching Connections for -a state object. Both are in response to receiving ID payloads (one in -Phase 1 / Main Mode and one in Phase 2 / Quick Mode). The second is -not unique to Road Warriors. In fact, neither is the first any more -(two connections for the same pair of hosts could differ in Phase 1 ID -payload; probably nobody else has tried this).</PRE> -<H3><A name="cantorient">Pluto: ... can't orient connection</A></H3> -<P>Older versions of FreeS/WAN used this message. The same error now - gives the "we have no ipsecN ..." error described just below.</P> -<H3><A name="no.interface">... we have no ipsecN interface for either - end of this connection</A></H3> -<P>Your tunnel has no IP address which matches the IP address of any of - the available IPsec interfaces. Either you've misconfigured the - connection, or you need to define an appropriate IPsec interface - connection.<VAR> interfaces=%defaultroute</VAR> works in many cases.</P> -<P>A longer story: Pluto needs to know whether it is running on the - machine which the connection description calls<VAR> left</VAR> or on<VAR> - right</VAR>. It figures that out by:</P> -<UL> -<LI>looking at the interfaces given in<VAR> interfaces=</VAR> lines in - the<VAR> config setup</VAR> section</LI> -<LI>discovering the IP addresses for those interfaces</LI> -<LI>searching for a match between those addresses and the ones given in<VAR> - left=</VAR> or<VAR> right=</VAR> lines.</LI> -</UL> -<P>Normally a match is found. Then Pluto knows where it is and can set - up other things (for example, if it is<VAR> left</VAR>) using - parameters such as<VAR> leftsubnet</VAR> and<VAR> leftnexthop</VAR>, - and sending its outgoing packets to<VAR> right</VAR>.</P> -<P>If no match is found, it emits the above error message.</P> -<H3><A name="noconn">Pluto: ... no connection is known</A></H3> -<P>This error message occurs when a remote system attempts to negotiate - a connection and Pluto does not have a connection description that - matches what the remote system has requested. The most common cause is - a configuration error on one end or the other.</P> -<P>Parameters involved in this match are<VAR> left</VAR>,<VAR> right</VAR> -,<VAR> leftsubnet</VAR> and<VAR> rightsubnet</VAR>.</P> -<P><STRONG>The match must be exact</STRONG>. For example, if your left - subnet is a.b.c.0/24 then neither a single machine in that net nor a - smaller subnet such as a.b.c.64/26 will be considered a match.</P> -<P>The message can also occur when an appropriate description exists but - Pluto has not loaded it. Use an<VAR> auto=add</VAR> statement in the - connection description, or an<VAR> ipsec auto --add <conn_name></VAR> - command, to correct this.</P> -<P>An explanation from the Pluto developer:</P> -<PRE>| Jul 12 15:00:22 sohar58 Pluto[574]: "corp_road" #2: cannot respond to IPsec -| SA request because no connection is known for -| 216.112.83.112/32===216.112.83.112...216.67.25.118 - -This is the first message from the Pluto log showing a problem. It -means that PGPnet is trying to negotiate a set of SAs with this -topology: - -216.112.83.112/32===216.112.83.112...216.67.25.118 -^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^ ^^^^^^^^^^^^^ -client on our side our host PGPnet host, no client - -None of the conns you showed look like this. - -Use - ipsec auto --status -to see a snapshot of what connections are in pluto, what -negotiations are going on, and what SAs are established. - -The leftsubnet= (client) in your conn is 216.112.83.64/26. It must -exactly match what pluto is looking for, and it does not.</PRE> -<H3><A name="nosuit">Pluto: ... no suitable connection ...</A></H3> -<P>This is similar to the<A href="#noconn"> no connection known</A> - error, but occurs at a different point in Pluto processing.</P> -<P>Here is one of Claudia's messages explaining the problem:</P> -<PRE>You write, - -> What could be the reason of the following error? -> "no suitable connection for peer '@xforce'" - -When a connection is initiated by the peer, Pluto must choose which entry in -the conf file best matches the incoming connection. A preliminary choice is -made on the basis of source and destination IPs, since that information is -available at that time. - -A payload containing an ID arrives later in the negotiation. Based on this -id and the *id= parameters, Pluto refines its conn selection. ... - -The message "no suitable connection" indicates that in this refining step, -Pluto does not find a connection that matches that ID. - -Please see "Selecting a connection when responding" in man ipsec_pluto for -more details.</PRE> -<P>See also<A href="#conn_name"> Connection names in Pluto error - messages</A>.</P> -<H3><A name="noconn.auth">Pluto: ... no connection has been authorized</A> -</H3> -<P>Here is one of Claudia's messages discussing this problem:</P> -<PRE>You write, - -> May 22 10:46:31 debian Pluto[25834]: packet from x.y.z.p:10014: -> initial Main Mode message from x.y.z.p:10014 - but no connection has been authorized - -This error occurs early in the connection negotiation process, -at the first step of IKE negotiation (Main Mode), which is itself the -first of two negotiation phases involved in creating an IPSec connection. - -Here, Linux FreeS/WAN receives a packet from a potential peer, which -requests that they begin discussing a connection. - -The "no connection has been authorized" means that there is no connection -description in Linux FreeS/WAN's internal database that can be used to -link your ipsec interface with that peer. - -"But of course I configured that connection!" - -It may be that the appropriate connection description exists in ipsec.conf -but has not been added to the database with ipsec auto --add myconn or the -auto=add method. Or, the connection description may be misconfigured. - -The only parameters that are relevant in this decision are left= and right= . -Local and remote ports are also taken into account -- we see that the port -is printed in the message above -- but there is no way to control these -in ipsec.conf. - - -Failure at "no connection has been authorized" is similar to the -"no connection is known for..." error in the FAQ, and the "no suitable -connection" error described in the snapshot's FAQ. In all three cases, -Linux FreeS/WAN is trying to match parameters received in the -negotiation with the connection description in the local config file. - -As it receives more information, its matches take more parameters into -account, and become more precise: first the pair of potential peers, -then the peer IDs, then the endpoints (including any subnets). - -The "no suitable connection for peer *" occurs toward the end of IKE -(Main Mode) negotiation, when the IDs are matched. - -"no connection is known for a/b===c...d" is seen at the beginning of IPSec -(Quick Mode, phase 2) negotiation, when the connections are matched using -left, right, and any information about the subnets.</PRE> -<H3><A name="noDESsupport">Pluto: ... OAKLEY_DES_CBC is not supported.</A> -</H3> -<P>This message occurs when the other system attempts to negotiate a - connection using<A href="glossary.html#DES"> single DES</A>, which we - do not support because it is<A href="politics.html#desnotsecure"> - insecure</A>.</P> -<P>Our interoperation document has suggestions for<A href="interop.html#noDES"> - how to deal with</A> systems that attempt to use single DES.</P> -<H3><A name="notransform">Pluto: ... no acceptable transform</A></H3> -<P>This message means that the other gateway has made a proposal for - connection parameters, but nothing they proposed is acceptable to - Pluto. Possible causes include:</P> -<UL> -<LI>misconfiguration on either end</LI> -<LI>policy incompatibilities, for example we require encrypted - connections but they are trying to create one with just authentication</LI> -<LI>interoperation problems, for example they offer only single DES and - FreeS/WAN does not support that. See<A href="interop.html#interop.problem"> - discussion</A> in our interoperation document.</LI> -</UL> -<P>A more detailed explanation, from Pluto programmer Hugh Redelmeier:</P> -<PRE>Background: - -When one IKE system (for example, Pluto) is negotiating with another -to create an SA, the Initiator proposes a bunch of choices and the -Responder replies with one that it has selected. - -The structure of the choices is fairly complicated. An SA payload -contains a list of lists of "Proposals". The outer list is a set of -choices: the selection must be from one element of this list. - -Each of these elements is a list of Proposals. A selection must be -made from each of the elements of the inner list. In other words, -*all* of them apply (that is how, for example, both AH and ESP can -apply at once). - -Within each of these Proposals is a list of Transforms. For each -Proposal selected, one Transform must be selected (in other words, -each Proposal provides a choice of Transforms). - -Each Transform is made up of a list of Attributes describing, well, -attributes. Such as lifetime of the SA. Such as algorithm to be -used. All the Attributes apply to a Transform. - -You will have noticed a pattern here: layers alternate between being -disjunctions ("or") and conjunctions ("and"). - -For Phase 1 / Main Mode (negotiating an ISAKMP SA), this structure is -cut back. There must be exactly one Proposal. So this degenerates to -a list of Transforms, one of which must be chosen. - -In your case, no proposal was considered acceptable to Pluto (the -Responder). So negotiation ceased. Pluto logs the reason it rejects -each Transform. So look back in the log to see what is going wrong.</PRE> -<H3><A name="rsasigkey">rsasigkey dumps core</A></H3> - A comment on this error from Henry: -<PRE>On Fri, 29 Jun 2001, Rodrigo Gruppelli wrote: -> ...Well, it seem that there's -> another problem with it. When I try to generate a pair of RSA keys, -> rsasigkey cores dump... - -*That* is a neon sign flashing "GMP LIBRARY IS BROKEN". Rsasigkey calls -GMP a lot, and our own library a little bit, and that's very nearly all it -does. Barring bugs in its code or our library -- which have happened, but -not very often -- a problem in rsasigkey is a problem in GMP.</PRE> -<P>See the next question for how to deal with GMP errors.</P> -<H3><A name="sig4">!Pluto failure!: ... exited with ... signal 4</A></H3> -<P>Pluto has died. Signal 4 is SIGILL, illegal instruction.</P> -<P>The most likely cause is that your<A href="glossary.html#GMP"> GMP</A> - (GNU multi-precision) library is compiled for a different processor - than what you are running on. Pluto uses that library for its public - key calculations.</P> -<P>Try getting the GMP sources and recompile for your processor type. - Most Linux distributions will include this source, or you can download - it from the<A href="http://www.swox.com/gmp/"> GMP home page</A>.</P> -<H3><A name="econnrefused">ECONNREFUSED error message</A></H3> -<P>From John Denker, on the mailing list:</P> -<PRE>1) The log message - some IKE message we sent has been rejected with - ECONNREFUSED (kernel supplied no details) -is much more suitable than the previous version. Thanks. - -2) Minor suggestion for further improvement: it might be worth mentioning -that the command - tcpdump -i eth1 icmp[0] != 8 and icmp[0] != 0 -is useful for tracking down the details in question. We shouldn't expect -all IPsec users to figure that out on their own. The log message might -even provide a hint as to where to look in the docs.</PRE> -<P>Reply From Pluto developer Hugh Redelmeier</P> -<PRE>Good idea. - -I've added a bit pluto(8)'s BUGS section along these lines. -I didn't have the heart to lengthen this message.</PRE> -<H3><A name="no_eroute">klips_debug: ... no eroute!</A></H3> -<P>This message means<A href="glossary.html#KLIPS"> KLIPS</A> has - received a packet for which no IPsec tunnel has been defined.</P> -<P>Here is a more detailed duscussion from the team's tech support - person Claudia Schmeing, responding to a query on the mailing list:</P> -<PRE>> Why ipsec reports no eroute! ???? IP Masq... is disabled. - -In general, more information is required so that people on the list may -give you informed input. See doc/prob.report.</PRE> -<P>The document she refers to has since been replaced by a<A href="trouble.html#prob.report"> - section</A> of the troubleshooting document.</P> -<PRE>However, I can make some general comments on this type of error. - -This error usually looks something like this (clipped from an archived -message): - -> ttl:64 proto:1 chk:45459 saddr:192.168.1.2 daddr:192.168.100.1 -> ... klips_debug:ipsec_findroute: 192.168.1.2->192.168.100.1 -> ... klips_debug:rj_match: * See if we match exactly as a host destination -> ... klips_debug:rj_match: ** try to match a leaf, t=0xc1a260b0 -> ... klips_debug:rj_match: *** start searching up the tree, t=0xc1a260b0 -> ... klips_debug:rj_match: **** t=0xc1a260c8 -> ... klips_debug:rj_match: **** t=0xc1fe5960 -> ... klips_debug:rj_match: ***** not found. -> ... klips_debug:ipsec_tunnel_start_xmit: Original head/tailroom: 2, 28 -> ... klips_debug:ipsec_tunnel_start_xmit: no eroute!: ts=47.3030, dropping. - - -What does this mean? -- -------------------- - -"eroute" stands for "extended route", and is a special type of route -internal to Linux FreeS/WAN. For more information about this type of route, -see the section of man ipsec_auto on ipsec auto --route. - -"no eroute!" here means, roughly, that Linux FreeS/WAN cannot find an -appropriate tunnel that should have delivered this packet. Linux -FreeS/WAN therefore drops the packet, with the message "no eroute! ... -dropping", on the assumption that this packet is not a legitimate -transmission through a properly constructed tunnel. - - -How does this situation come about? -- ----------------------------------- - -Linux FreeS/WAN has a number of connection descriptions defined in -ipsec.conf. These must be successfully brought "up" to form actual tunnels. -(see doc/setup.html's step 15, man ipsec.conf and man ipsec_auto -for details). - -Such connections are often specific to the endpoints' IPs. However, in -some cases they may be more general, for example in the case of -Road Warriors where left or right is the special value %any. - -When Linux FreeS/WAN receives a packet, it verifies that the packet has -come through a legitimate channel, by checking that there is an -appropriate tunnel through which this packet might legitimately have -arrived. This is the process we see above. - -First, it checks for an eroute that exactly matches the packet. In the -example above, we see it checking for a route that begins at 192.168.1.2 -and ends at 192.168.100.1. This search favours the most specific match that -would apply to the route between these IPs. So, if there is a connection -description exactly matching these IPs, the search will end there. If not, -the code will search for a more general description matching the IPs. -If there is no match, either specific or general, the packet will be -dropped, as we see, above. - -Unless you are working with Road Warriors, only the first, specific part -of the matching process is likely to be relevant to you. - - -"But I defined the tunnel, and it came up, why do I have this error?" -- --------------------------------------------------------------------- - -One of the most common causes of this error is failure to specify enough -connection descriptions to cover all needed tunnels between any two -gateways and their respective subnets. As you have noticed, troubleshooting -this error may be complicated by the use of IP Masq. However, this error is -not limited to cases where IP Masq is used. - -See doc/configuration.html#multitunnel for a detailed example of the -solution to this type of problem.</PRE> -<P>The documentation section she refers to is now<A href="adv_config.html#multitunnel"> - here</A>.</P> -<H3><A name="SAused">... trouble writing to /dev/ipsec ... SA already in - use</A></H3> -<P>This error message occurs when two manual connections are set up with - the same SPI value.</P> -<P>See the FAQ for<A href="#spi_error"> One manual connection works, but - second one fails</A>.</P> -<H3><A name="ignore">... ignoring ... payload</A></H3> -<P>This message is harmless. The IKE protocol provides for a number of - optional messages types:</P> -<UL> -<LI>delete SA</LI> -<LI>initial contact</LI> -<LI>vendor ID</LI> -<LI>...</LI> -</UL> -<P>An implementation is never required to send these, but they are - allowed to. The receiver is not required to do anything with them. - FreeS/WAN ignores them, but notifies you via the logs.</P> -<P>For the "ignoring delete SA Payload" message, see also our discussion - of cleaning up<A href="#deadtunnel"> dead tunnels</A>.</P> -<H3><A name="unknown_rightcert">unknown parameter name "rightcert"</A></H3> -<P>This message can appear when you've upgraded an X.509-enabled Linux - FreeS/WAN with a vanilla Linux FreeS/WAN. To use your X.509 configs you - will need to overwrite the new install with<A HREF="http://www.freeswan.ca"> - Super FreeS/WAN</A>, or add the<A HREF="http://www.strongsec.ca/freeswan"> - X.509 patch</A> by hand.</P> -<H2><A name="spam">Why don't you restrict the mailing lists to reduce - spam?</A></H2> -<P>As a matter of policy, some of our<A href="mail.html"> mailing lists</A> - need to be open to non-subscribers. Project management feel strongly - that maintaining this openness is more important than blocking spam.</P> -<UL> -<LI>Users should be able to get help or report bugs without subscribing.</LI> -<LI>Even a user who is subscribed may not have access to his or her - subscribed account when he or she needs help, miles from home base in - the middle of setting up a client's gateway.</LI> -<LI>There is arguably a legal requirement for this policy. A US resident - or citizen could be charged under munitions export laws for providing - technical assistance to a foreign cryptographic project. Such a charge - would be more easily defended if the discussion takes place in public, - on an open list.</LI> -</UL> -<P>This has been discussed several times at some length on the list. See - the<A href="mail.html#archive"> list archives</A>. Bringing the topic - up again is unlikely to be useful. Please don't. Or at the very least, - please don't without reading the archives and being certain that - whatever you are about to suggest has not yet been discussed.</P> -<P>Project technical lead Henry Spencer summarised one discussion:</P> -<BLOCKQUOTE> For the third and last time: this list *will* *not* do - address-based filtering. This is a policy decision, not an - implementation problem. The decision is final, and is not open to - discussion. This needs to be communicated better to people, and steps - are being taken to do that.</BLOCKQUOTE> -<P>Adding this FAQ section is one of the steps he refers to.</P> -<P>You have various options other than just putting up with the spam, - filtering it yourself, or unsubscribing:</P> -<UL> -<LI>subscribe only to one or both of our lists with restricted posting - rules: -<UL> -<LI><A href="mailto:briefs@lists.freeswan.org?body=subscribe">briefs</A> -, weekly list summaries</LI> -<LI><A href="mailto:announce@lists.freeswan.org?body=subscribe">announce</A> -, project-related announcements</LI> -</UL> -</LI> -<LI>read the other lists via the<A href="mail.html#archive"> archives</A> -</LI> -</UL> -<P>A number of tools are available to filter mail.</P> -<UL> -<LI>Many mail readers include some filtering capability.</LI> -<LI>Many Linux distributions include<A href="http://www.procmail.org/"> - procmail(8)</A> for server-side filtering.</LI> -<LI>The<A href="http://www.spambouncer.org/"> Spam Bouncer</A> is a set - of procmail(8) filters designed to combat spam.</LI> -<LI>Roaring Penguin have a<A href="http://www.roaringpenguin.com/mimedefang/"> - MIME defanger</A> that removes potentially dangerous attachments.</LI> -</UL> -<P>If you use your ISP's mail server rather than running your own, - consider suggesting to the ISP that they tag suspected spam as<A href="http://www.msen.com/1997/spam.html#SUSPECTED"> - this ISP</A> does. They could just refuse mail from dubious sources, - but that is tricky and runs some risk of losing valuable mail or - senselessly annoying senders and their admins. However, they can safely - tag and deliver dubious mail. The tags can greatly assist your - filtering.</P> -<P>For information on tracking down spammers, see these<A href="http://www.rahul.net/falk/#howtos"> - HowTos</A>, or the<A href="http://www.sputum.com/index2.html"> Sputum</A> - site. Sputum have a Linux anti-spam screensaver available for download.</P> -<P>Here is a more detailed message from Henry:</P> -<PRE>On Mon, 15 Jan 2001, Jay Vaughan wrote: -> I know I'm flogging a dead horse here, but I'm curious as to the reasons for -> an aversion for a subscriber-only mailing list? - -Once again: for legal reasons, it is important that discussions of these -things be held in a public place -- the list -- and we do not want to -force people to subscribe to the list just to ask one question, because -that may be more than merely inconvenient for them. There are also real -difficulties with people who are temporarily forced to use alternate -addresses; that is precisely the time when they may be most in need of -help, yet a subscribers-only policy shuts them out. - -These issues do not apply to most mailing lists, but for a list that is -(necessarily) the primary user support route for a crypto package, they -are very important. This is *not* an ordinary mailing list; it has to -function under awkward constraints that make various simplistic solutions -inapplicable or undesirable. - -> We're *ALL* sick of hearing about list management problems, not just you -> old-timers, so why don't you DO SOMETHING EFFECTIVE ABOUT IT... - -Because it's a lot harder than it looks, and many existing "solutions" -have problems when examined closely. - -> A suggestion for you, based on 10 years of experience with management of my -> own mailing lists would be to use mailman, which includes pretty much every -> feature under the sun that you guys need and want, plus some. The URL for -> mailman... - -I assure you, we're aware of mailman. Along with a whole bunch of others, -including some you almost certainly have never heard of (I hadn't!). - -> As for the argument that the list shouldn't be configured to enforce -> subscription - I contend that it *SHOULD* AT LEAST require manual address -> verification in order for posts to be redirected. - -You do realize, I hope, that interposing such a manual step might cause -your government to decide that this is not truly a public forum, and thus -you could go to jail if you don't get approval from them before mailing to -it? If you think this sounds irrational, your government is noted for -making irrational decisions in this area; we can't assume that they will -suddenly start being sensible. See above about awkward constraints. You -may be willing to take the risk, but we can't, in good conscience, insist -that all users with problems do so. - - Henry Spencer - henry@spsystems.net</PRE> -<P>and a message on the topic from project leader John Gilmore:</P> -<PRE>Subject: Re: The linux-ipsec list's topic - Date: Sat, 30 Dec 2000 - From: John Gilmore <gnu@toad.com> - -I'll post this single message, once only, in this discussion, and then -not burden the list with any further off-topic messages. I encourage -everyone on the list to restrain themself from posting ANY off-topic -messages to the linux-ipsec list. - -The topic of the linux-ipsec mailing list is the FreeS/WAN software. - -I frequently see "discussions about spam on a list" overwhelm the -volume of "actual spam" on a list. BOTH kinds of messages are -off-topic messages. Twenty anti-spam messages take just as long to -detect and discard as twenty spam messages. - -The Linux-ipsec list encourages on-topic messages from people who have -not joined the list itself. We will not censor messages to the list -based on where they originate, or what return address they contain. -In other words, non-subscribers ARE allowed to post, and this will not -change. My own valid contributions have been rejected out-of-hand by -too many other mailing lists for me to want to impose that censorship -on anybody else's contributions. And every day I see the damage that -anti-spam zeal is causing in many other ways; that zeal is far more -damaging to the culture of the Internet than the nuisance of spam. - -In general, it is the responsibility of recipients to filter, -prioritize, or otherwise manage the handling of email that comes to -them. It is not the responsibility of the rest of the Internet -community to refrain from sending messages to recipients that they -might not want to see. If your software infrastructure for managing -your incoming email is insufficient, then improve it. If you think -the signal-to-noise ratio on linux-ipsec is too poor, then please -unsubscribe. But don't further increase the noise by posting to the -linux-ipsec list about those topics. - - John Gilmore - founder & sponsor, FreeS/WAN project</PRE> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="policygroups.html">Previous</A> -<A HREF="manpages.html">Next</A> -</BODY> -</HTML> diff --git a/doc/firewall.html b/doc/firewall.html deleted file mode 100644 index 0747ab83d..000000000 --- a/doc/firewall.html +++ /dev/null @@ -1,767 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="manpages.html">Previous</A> -<A HREF="trouble.html">Next</A> -<HR> -<H1><A name="firewall">FreeS/WAN and firewalls</A></H1> -<P>FreeS/WAN, or other IPsec implementations, frequently run on gateway - machines, the same machines running firewall or packet filtering code. - This document discusses the relation between the two.</P> -<P>The firewall code in 2.4 and later kernels is called Netfilter. The - user-space utility to manage a firewall is iptables(8). See the<A href="http://netfilter.samba.org"> - netfilter/iptables web site</A> for details.</P> -<H2><A name="filters">Filtering rules for IPsec packets</A></H2> -<P>The basic constraint is that<STRONG> an IPsec gateway must have - packet filters that allow IPsec packets</STRONG>, at least when talking - to other IPsec gateways:</P> -<UL> -<LI>UDP port 500 for<A href="glossary.html#IKE"> IKE</A> negotiations</LI> -<LI>protocol 50 if you use<A href="glossary.html#ESP"> ESP</A> - encryption and/or authentication (the typical case)</LI> -<LI>protocol 51 if you use<A href="glossary.html#AH"> AH</A> - packet-level authentication</LI> -</UL> -<P>Your gateway and the other IPsec gateways it communicates with must - be able to exchange these packets for IPsec to work. Firewall rules - must allow UDP 500 and at least one of<A href="glossary.html#AH"> AH</A> - or<A href="glossary.html#ESP"> ESP</A> on the interface that - communicates with the other gateway.</P> -<P>For nearly all FreeS/WAN applications, you must allow UDP port 500 - and the ESP protocol.</P> -<P>There are two ways to set this up:</P> -<DL> -<DT>easier but less flexible</DT> -<DD>Just set up your firewall scripts at boot time to allow IPsec - packets to and from your gateway. Let FreeS/WAN reject any bogus - packets.</DD> -<DT>more work, giving you more precise control</DT> -<DD>Have the<A href="manpage.d/ipsec_pluto.8.html"> ipsec_pluto(8)</A> - daemon call scripts to adjust firewall rules dynamically as required. - This is done by naming the scripts in the<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A> variables<VAR> prepluto=</VAR>,<VAR> postpluto=</VAR> -,<VAR> leftupdown=</VAR> and<VAR> rightupdown=</VAR>.</DD> -</DL> -<P>Both methods are described in more detail below.</P> -<H2><A name="examplefw">Firewall configuration at boot</A></H2> -<P>It is possible to set up both firewalling and IPsec with appropriate - scripts at boot and then not use<VAR> leftupdown=</VAR> and<VAR> - rightupdown=</VAR>, or use them only for simple up and down operations.</P> -<P>Basically, the technique is</P> -<UL> -<LI>allow IPsec packets (typically, IKE on UDP port 500 plus ESP, - protocol 50) -<UL> -<LI>incoming, if the destination address is your gateway (and - optionally, only from known senders)</LI> -<LI>outgoing, with the from address of your gateway (and optionally, - only to known receivers)</LI> -</UL> -</LI> -<LI>let<A href="glossary.html#Pluto"> Pluto</A> deal with IKE</LI> -<LI>let<A href="glossary.html#KLIPS"> KLIPS</A> deal with ESP</LI> -</UL> -<P>Since Pluto authenticates its partners during the negotiation, and - KLIPS drops packets for which no tunnel has been negotiated, this may - be all you need.</P> -<H3><A name="simple.rules">A simple set of rules</A></H3> -<P>In simple cases, you need only a few rules, as in this example:</P> -<PRE># allow IPsec -# -# IKE negotiations -iptables -I INPUT -p udp --sport 500 --dport 500 -j ACCEPT -iptables -I OUTPUT -p udp --sport 500 --dport 500 -j ACCEPT -# ESP encryption and authentication -iptables -I INPUT -p 50 -j ACCEPT -iptables -I OUTPUT -p 50 -j ACCEPT -</PRE> -<P>This should be all you need to allow IPsec through<VAR> lokkit</VAR>, - which ships with Red Hat 9, on its medium security setting. Once you've - tweaked to your satisfaction, save your active rule set with:</P> -<PRE>service iptables save</PRE> -<H3><A name="complex.rules">Other rules</A></H3> - You can add additional rules, or modify existing ones, to work with - IPsec and with your network and policies. We give a some examples in - this section. -<P>However, while it is certainly possible to create an elaborate set of - rules yourself (please let us know via the<A href="mail.html"> mailing - list</A> if you do), it may be both easier and more secure to use a set - which has already been published and tested.</P> -<P>The published rule sets we know of are described in the<A href="#rules.pub"> - next section</A>.</P> -<H4>Adding additional rules</H4> - If necessary, you can add additional rules to: -<DL> -<DT>reject IPsec packets that are not to or from known gateways</DT> -<DD>This possibility is discussed in more detail<A href="#unknowngate"> - later</A></DD> -<DT>allow systems behind your gateway to build IPsec tunnels that pass - through the gateway</DT> -<DD>This possibility is discussed in more detail<A href="#through"> - later</A></DD> -<DT>filter incoming packets emerging from KLIPS.</DT> -<DD>Firewall rules can recognise packets emerging from IPsec. They are - marked as arriving on an interface such as<VAR> ipsec0</VAR>, rather - than<VAR> eth0</VAR>,<VAR> ppp0</VAR> or whatever.</DD> -</DL> -<P>It is therefore reasonably straightforward to filter these packets in - whatever way suits your situation.</P> -<H4>Modifying existing rules</H4> -<P>In some cases rules that work fine before you add IPsec may require - modification to work with IPsec.</P> -<P>This is especially likely for rules that deal with interfaces on the - Internet side of your system. IPsec adds a new interface; often the - rules must change to take account of that.</P> -<P>For example, consider the rules given in<A href="http://www.netfilter.org/documentation/HOWTO//packet-filtering-HOWTO-5.html"> - this section</A> of the Netfilter documentation:</P> -<PRE>Most people just have a single PPP connection to the Internet, and don't -want anyone coming back into their network, or the firewall: - - ## Insert connection-tracking modules (not needed if built into kernel). - # insmod ip_conntrack - # insmod ip_conntrack_ftp - - ## Create chain which blocks new connections, except if coming from inside. - # iptables -N block - # iptables -A block -m state --state ESTABLISHED,RELATED -j ACCEPT - # iptables -A block -m state --state NEW -i ! ppp0 -j ACCEPT - # iptables -A block -j DROP - - ## Jump to that chain from INPUT and FORWARD chains. - # iptables -A INPUT -j block - # iptables -A FORWARD -j block</PRE> -<P>On an IPsec gateway, those rules may need to be modified. The above - allows new connections from<EM> anywhere except ppp0</EM>. That means - new connections from ipsec0 are allowed.</P> -<P>Do you want to allow anyone who can establish an IPsec connection to - your gateway to initiate TCP connections to any service on your - network? Almost certainly not if you are using opportunistic - encryption. Quite possibly not even if you have only explicitly - configured connections.</P> -<P>To disallow incoming connections from ipsec0, change the middle - section above to:</P> -<PRE> ## Create chain which blocks new connections, except if coming from inside. - # iptables -N block - # iptables -A block -m state --state ESTABLISHED,RELATED -j ACCEPT - # iptables -A block -m state --state NEW -i ppp+ -j DROP - # iptables -A block -m state --state NEW -i ipsec+ -j DROP - # iptables -A block -m state --state NEW -i -j ACCEPT - # iptables -A block -j DROP</PRE> -<P>The original rules accepted NEW connections from anywhere except - ppp0. This version drops NEW connections from any PPP interface (ppp+) - and from any ipsec interface (ipsec+), then accepts the survivors.</P> -<P>Of course, these are only examples. You will need to adapt them to - your own situation.</P> -<H3><A name="rules.pub">Published rule sets</A></H3> -<P>Several sets of firewall rules that work with FreeS/WAN are - available.</P> -<H4><A name="Ranch.trinity">Scripts based on Ranch's work</A></H4> -<P>One user, Rob Hutton, posted his boot time scripts to the mailing - list, and we included them in previous versions of this documentation. - They are still available from our<A href="http://www.freeswan.org/freeswan_trees/freeswan-1.5/doc/firewall.html#examplefw"> - web site</A>. However, they were for an earlier FreeS/WAN version so we - no longer recommend them. Also, they had some bugs. See this<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/04/msg00316.html"> - message</A>.</P> -<P>Those scripts were based on David Ranch's scripts for his "Trinity - OS" for setting up a secure Linux. Check his<A href="http://www.ecst.csuchico.edu/~dranch/LINUX/index-linux.html"> - home page</A> for the latest version and for information on his<A href="biblio.html#ranch"> - book</A> on securing Linux. If you are going to base your firewalling - on Ranch's scripts, we recommend using his latest version, and sending - him any IPsec modifications you make for incorporation into later - versions.</P> -<H4><A name="seawall">The Seattle firewall</A></H4> -<P>We have had several mailing lists reports of good results using - FreeS/WAN with Seawall (the Seattle Firewall). See that project's<A href="http://seawall.sourceforge.net/"> - home page</A> on Sourceforge.</P> -<H4><A name="rcf">The RCF scripts</A></H4> -<P>Another set of firewall scripts with IPsec support are the RCF or - rc.firewall scripts. See their<A href="http://jsmoriss.mvlan.net/linux/rcf.html"> - home page</A>.</P> -<H4><A name="asgard">Asgard scripts</A></H4> -<P><A href="http://heimdall.asgardsrealm.net/linux/firewall/">Asgard's - Realm</A> has set of firewall scripts with FreeS/WAN support, for 2.4 - kernels and iptables.</P> -<H4><A name="user.scripts">User scripts from the mailing list</A></H4> -<P>One user gave considerable detail on his scripts, including - supporting<A href="glossary.html#IPX"> IPX</A> through the tunnel. His - message was too long to conveniently be quoted here, so I've put it in - a<A href="user_examples.html"> separate file</A>.</P> -<H2><A name="updown">Calling firewall scripts, named in ipsec.conf(5)</A> -</H2> -<P>The<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5)</A> - configuration file has three pairs of parameters used to specify an - interface between FreeS/WAN and firewalling code.</P> -<P>Note that using these is not required if you have a static firewall - setup. In that case, you just set your firewall up at boot time (in a - way that permits the IPsec connections you want) and do not change it - thereafter. Omit all the FreeS/WAN firewall parameters and FreeS/WAN - will not attempt to adjust firewall rules at all. See<A href="#examplefw"> - above</A> for some information on appropriate scripts.</P> -<P>However, if you want your firewall rules to change when IPsec - connections change, then you need to use these parameters.</P> -<H3><A name="pre_post">Scripts called at IPsec start and stop</A></H3> -<P>One pair of parmeters are set in the<VAR> config setup</VAR> section - of the<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5)</A> file and - affect all connections:</P> -<DL> -<DT>prepluto=</DT> -<DD>script to be called before<A href="manpage.d/ipsec_pluto.8.html"> - pluto(8)</A> IKE daemon is started.</DD> -<DT>postpluto=</DT> -<DD>script to be called after<A href="manpage.d/ipsec_pluto.8.html"> - pluto(8)</A> IKE daemon is stopped.</DD> -</DL> - These parameters allow you to change firewall parameters whenever IPsec - is started or stopped. -<P>They can also be used in other ways. For example, you might have<VAR> - prepluto</VAR> add a module to your kernel for the secure network - interface or make a dialup connection, and then have<VAR> postpluto</VAR> - remove the module or take the connection down.</P> -<H3><A name="up_down">Scripts called at connection up and down</A></H3> -<P>The other parameters are set in connection descriptions. They can be - set in individual connection descriptions, and could even call - different scripts for each connection for maximum flexibility. In most - applications, however, it makes sense to use only one script and to - call it from<VAR> conn %default</VAR> section so that it applies to all - connections.</P> -<P>You can:</P> -<DL> -<DT><STRONG>either</STRONG></DT> -<DD>set<VAR> leftfirewall=yes</VAR> or<VAR> rightfirewall=yes</VAR> to - use our supplied default script</DD> -<DT><STRONG>or</STRONG></DT> -<DD>assign a name in a<VAR> leftupdown=</VAR> or<VAR> rightupdown=</VAR> - line to use your own script</DD> -</DL> -<P>Note that<STRONG> only one of these should be used</STRONG>. You - cannot sensibly use both. Since<STRONG> our default script is obsolete</STRONG> - (designed for firewalls using<VAR> ipfwadm(8)</VAR> on 2.0 kernels), - most users who need this service will<STRONG> need to write a custom - script</STRONG>.</P> -<H4><A name="fw.default">The default script</A></H4> -<P>We supply a default script named<VAR> _updown</VAR>.</P> -<DL> -<DT>leftfirewall=</DT> -<DD></DD> -<DT>rightfirewall=</DT> -<DD>indicates that the gateway is doing firewalling and that<A href="manpage.d/ipsec_pluto.8.html"> - pluto(8)</A> should poke holes in the firewall as required.</DD> -</DL> -<P>Set these to<VAR> yes</VAR> and Pluto will call our default script<VAR> - _updown</VAR> with appropriate arguments whenever it:</P> -<UL> -<LI>starts or stops IPsec services</LI> -<LI>brings a connection up or down</LI> -</UL> -<P>The supplied default<VAR> _updown</VAR> script is appropriate for - simple cases using the<VAR> ipfwadm(8)</VAR> firewalling package.</P> -<H4><A name="userscript">User-written scripts</A></H4> -<P>You can also write your own script and have Pluto call it. Just put - the script's name in one of these<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A> lines:</P> -<DL> -<DT>leftupdown=</DT> -<DD></DD> -<DT>rightupdown=</DT> -<DD>specifies a script to call instead of our default script<VAR> - _updown</VAR>.</DD> -</DL> -<P>Your script should take the same arguments and use the same - environment variables as<VAR> _updown</VAR>. See the "updown command" - section of the<A href="manpage.d/ipsec_pluto.8.html"> ipsec_pluto(8)</A> - man page for details.</P> -<P>Note that<STRONG> you should not modify our _updown script in place</STRONG> -. If you did that, then upgraded FreeS/WAN, the upgrade would install a - new default script, overwriting your changes.</P> -<H3><A name="ipchains.script">Scripts for ipchains or iptables</A></H3> -<P>Our<VAR> _updown</VAR> is for firewalls using<VAR> ipfwadm(8)</VAR>, - the firewall code for the 2.0 series of Linux kernels. If you are using - the more recent packages<VAR> ipchains(8)</VAR> (for 2.2 kernels) or<VAR> - iptables(8)</VAR> (2.4 kernels), then you must do one of:</P> -<UL> -<LI>use static firewall rules which are set up at boot time as described<A -href="#examplefw"> above</A> and do not need to be changed by Pluto</LI> -<LI>limit yourself to ipchains(8)'s ipfwadm(8) emulation mode in order - to use our script</LI> -<LI>write your own script and call it with<VAR> leftupdown</VAR> and<VAR> - rightupdown</VAR>.</LI> -</UL> -<P>You can write a script to do whatever you need with firewalling. - Specify its name in a<VAR> [left|right]updown=</VAR> parameter in<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A> and Pluto will automatically call it for you.</P> -<P>The arguments Pluto passes such a script are the same ones it passes - to our default _updown script, so the best way to build yours is to - copy ours and modify the copy.</P> -<P>Note, however, that<STRONG> you should not modify our _updown script - in place</STRONG>. If you did that, then upgraded FreeS/WAN, the - upgrade would install a new default script, overwriting your changes.</P> -<H2><A name="NAT">A complication: IPsec vs. NAT</A></H2> -<P><A href="glossary.html#NAT.gloss">Network Address Translation</A>, - also known as IP masquerading, is a method of allocating IP addresses - dynamically, typically in circumstances where the total number of - machines which need to access the Internet exceeds the supply of IP - addresses.</P> -<P>Any attempt to perform NAT operations on IPsec packets<EM> between - the IPsec gateways</EM> creates a basic conflict:</P> -<UL> -<LI>IPsec wants to authenticate packets and ensure they are unaltered on - a gateway-to-gateway basis</LI> -<LI>NAT rewrites packet headers as they go by</LI> -<LI>IPsec authentication fails if packets are rewritten anywhere between - the IPsec gateways</LI> -</UL> -<P>For<A href="glossary.html#AH"> AH</A>, which authenticates parts of - the packet header including source and destination IP addresses, this - is fatal. If NAT changes those fields, AH authentication fails.</P> -<P>For<A href="glossary.html#IKE"> IKE</A> and<A href="glossary.html#ESP"> - ESP</A> it is not necessarily fatal, but is certainly an unwelcome - complication.</P> -<H3><A name="nat_ok">NAT on or behind the IPsec gateway works</A></H3> -<P>This problem can be avoided by having the masquerading take place<EM> - on or behind</EM> the IPsec gateway.</P> -<P>This can be done physically with two machines, one physically behind - the other. A picture, using SG to indicate IPsec<STRONG> S</STRONG> -ecurity<STRONG> G</STRONG>ateways, is:</P> -<PRE> clients --- NAT ----- SG ---------- SG - two machines</PRE> -<P>In this configuration, the actual client addresses need not be given - in the<VAR> leftsubnet=</VAR> parameter of the FreeS/WAN connection - description. The security gateway just delivers packets to the NAT box; - it needs only that machine's address. What that machine does with them - does not affect FreeS/WAN.</P> -<P>A more common setup has one machine performing both functions:</P> -<PRE> clients ----- NAT/SG ---------------SG - one machine</PRE> -<P>Here you have a choice of techniques depending on whether you want to - make your client subnet visible to clients on the other end:</P> -<UL> -<LI>If you want the single gateway to behave like the two shown above, - with your clients hidden behind the NAT, then omit the<VAR> leftsubnet=</VAR> - parameter. It then defaults to the gateway address. Clients on the - other end then talk via the tunnel only to your gateway. The gateway - takes packets emerging from the tunnel, applies normal masquerading, - and forwards them to clients.</LI> -<LI>If you want to make your client machines visible, then give the - client subnet addresses as the<VAR> leftsubnet=</VAR> parameter in the - connection description and -<DL> -<DT>either</DT> -<DD>set<VAR> leftfirewall=yes</VAR> to use the default<VAR> updown</VAR> - script</DD> -<DT>or</DT> -<DD>use your own script by giving its name in a<VAR> leftupdown=</VAR> - parameter</DD> -</DL> - These scripts are described in their own<A href="#updown"> section</A>. -<P>In this case, no masquerading is done. Packets to or from the client - subnet are encrypted or decrypted without any change to their client - subnet addresses, although of course the encapsulating packets use - gateway addresses in their headers. Clients behind the right security - gateway see a route via that gateway to the left subnet.</P> -</LI> -</UL> -<H3><A name="nat_bad">NAT between gateways is problematic</A></H3> -<P>We recommend not trying to build IPsec connections which pass through - a NAT machine. This setup poses problems:</P> -<PRE> clients --- SG --- NAT ---------- SG</PRE> -<P>If you must try it, some references are:</P> -<UL> -<LI>Jean_Francois Nadeau's document on doing<A href="http://jixen.tripod.com/#NATed gateways"> - IPsec behind NAT</A></LI> -<LI><A href="web.html#VPN.masq">VPN masquerade patches</A> to make a - Linux NAT box handle IPsec packets correctly</LI> -</UL> -<H3><A name="NAT.ref">Other references on NAT and IPsec</A></H3> -<P>Other documents which may be relevant include:</P> -<UL> -<LI>an Internet Draft on<A href="http://search.ietf.org/internet-drafts/draft-aboba-nat-ipsec-04.txt"> - IPsec and NAT</A> which may eventually evolve into a standard solution - for this problem.</LI> -<LI>an informational<A href="http://www.cis.ohio-state.edu/rfc/rfc2709.txt"> - RFC</A>,<CITE> Security Model with Tunnel-mode IPsec for NAT Domains</CITE> -.</LI> -<LI>an<A href="http://www.cisco.com/warp/public/759/ipj_3-4/ipj_3-4_nat.html"> - article</A> in Cisco's<CITE> Internet Protocol Journal</CITE></LI> -</UL> -<H2><A name="complications">Other complications</A></H2> -<P>Of course simply allowing UDP 500 and ESP packets is not the whole - story. Various other issues arise in making IPsec and packet filters - co-exist and even co-operate. Some of them are summarised below.</P> -<H3><A name="through">IPsec<EM> through</EM></A> the gateway</H3> -<P>Basic IPsec packet filtering rules deal only with packets addressed - to or sent from your IPsec gateway.</P> -<P>It is a separate policy decision whether to permit such packets to - pass through the gateway so that client machines can build end-to-end - IPsec tunnels of their own. This may not be practical if you are using<A -href="#NAT"> NAT (IP masquerade)</A> on your gateway, and may conflict - with some corporate security policies.</P> -<P>Where possible, allowing this is almost certainly a good idea. Using - IPsec on an end-to-end basis is more secure than gateway-to-gateway.</P> -<P>Doing it is quite simple. You just need firewall rules that allow UDP - port 500 and protocols 50 and 51 to pass through your gateway. If you - wish, you can of course restrict this to certain hosts.</P> -<H3><A name="ipsec_only">Preventing non-IPsec traffic</A></H3> - You can also filter<EM> everything but</EM> UDP port 500 and ESP or AH - to restrict traffic to IPsec only, either for anyone communicating with - your host or just for specific partners. -<P>One application of this is for the telecommuter who might have:</P> -<PRE> Sunset==========West------------------East ================= firewall --- the Internet - home network untrusted net corporate network</PRE> -<P>The subnet on the right is 0.0.0.0/0, the whole Internet. The West - gateway is set up so that it allows only IPsec packets to East in or - out.</P> -<P>This configuration is used in AT&T Research's network. For details, - see the<A href="intro.html#applied"> papers</A> links in our - introduction.</P> -<P>Another application would be to set up firewall rules so that an - internal machine, such as an employees-only web server, could not talk - to the outside world except via specific IPsec tunnels.</P> -<H3><A name="unknowngate">Filtering packets from unknown gateways</A></H3> -<P>It is possible to use firewall rules to restrict UDP 500, ESP and AH - packets so that these packets are accepted only from known gateways. - This is not strictly necessary since FreeS/WAN will discard packets - from unknown gateways. You might, however, want to do it for any of a - number of reasons. For example:</P> -<UL> -<LI>Arguably, "belt and suspenders" is the sensible approach to - security. If you can block a potential attack in two ways, use both. - The only question is whether to look for a third way after implementing - the first two.</LI> -<LI>Some admins may prefer to use the firewall code this way because - they prefer firewall logging to FreeS/WAN's logging.</LI> -<LI>You may need it to implement your security policy. Consider an - employee working at home, and a policy that says traffic from the home - system to the Internet at large must go first via IPsec to the - corporate LAN and then out to the Internet via the corporate firewall. - One way to do that is to make<VAR> ipsec0</VAR> the default route on - the home gateway and provide exceptions only for UDP 500 and ESP to the - corporate gateway. Everything else is then routed via the tunnel to the - corporate gateway.</LI> -</UL> -<P>It is not possible to use only static firewall rules for this - filtering if you do not know the other gateways' IP addresses in - advance, for example if you have "road warriors" who may connect from a - different address each time or if want to do<A href="glossary.html#carpediem"> - opportunistic encryption</A> to arbitrary gateways. In these cases, you - can accept UDP 500 IKE packets from anywhere, then use the<A href="#updown"> - updown</A> script feature of<A href="manpage.d/ipsec_pluto.8.html"> - pluto(8)</A> to dynamically adjust firewalling for each negotiated - tunnel.</P> -<P>Firewall packet filtering does not much reduce the risk of a<A href="glossary.html#DOS"> - denial of service attack</A> on FreeS/WAN. The firewall can drop - packets from unknown gateways, but KLIPS does that quite efficiently - anyway, so you gain little. The firewall cannot drop otherwise - legitmate packets that fail KLIPS authentication, so it cannot protect - against an attack designed to exhaust resources by making FreeS/WAN - perform many expensive authentication operations.</P> -<P>In summary, firewall filtering of IPsec packets from unknown gateways - is possible but not strictly necessary.</P> -<H2><A name="otherfilter">Other packet filters</A></H2> -<P>When the IPsec gateway is also acting as your firewall, other packet - filtering rules will be in play. In general, those are outside the - scope of this document. See our<A href="web.html#firewall.linux"> Linux - firewall links</A> for information. There are a few types of packet, - however, which can affect the operation of FreeS/WAN or of diagnostic - tools commonly used with it. These are discussed below.</P> -<H3><A name="ICMP">ICMP filtering</A></H3> -<P><A href="glossary.html#ICMP.gloss">ICMP</A> is the<STRONG> I</STRONG> -nternet<STRONG> C</STRONG>ontrol<STRONG> M</STRONG>essage<STRONG> P</STRONG> -rotocol. It is used for messages between IP implementations themselves, - whereas IP used is used between the clients of those implementations. - ICMP is, unsurprisingly, used for control messages. For example, it is - used to notify a sender that a desination is not reachable, or to tell - a router to reroute certain packets elsewhere.</P> -<P>ICMP handling is tricky for firewalls.</P> -<UL> -<LI>You definitely want some ICMP messages to get through; things won't - work without them. For example, your clients need to know if some - destination they ask for is unreachable.</LI> -<LI>On the other hand, you do equally definitely do not want untrusted - folk sending arbitrary control messages to your machines. Imagine what - someone moderately clever and moderately malicious could do to you, - given control of your network's routing.</LI> -</UL> -<P>ICMP does not use ports. Messages are distinguished by a "message - type" field and, for some types, by an additional "code" field. The - definitive list of types and codes is on the<A href="http://www.iana.org"> - IANA</A> site.</P> -<P>One expert uses this definition for ICMP message types to be dropped - at the firewall.</P> -<PRE># ICMP types which lack socially redeeming value. -# 5 Redirect -# 9 Router Advertisement -# 10 Router Selection -# 15 Information Request -# 16 Information Reply -# 17 Address Mask Request -# 18 Address Mask Reply - -badicmp='5 9 10 15 16 17 18'</PRE> -<P>A more conservative approach would be to make a list of allowed types - and drop everything else.</P> -<P>Whichever way you do it, your ICMP filtering rules on a FreeS/WAN - gateway should allow at least the following ICMP packet types:</P> -<DL> -<DT>echo (type 8)</DT> -<DD></DD> -<DT>echo reply (type 0)</DT> -<DD>These are used by ping(1). We recommend allowing both types through - the tunnel and to or from your gateway's external interface, since - ping(1) is an essential testing tool. -<P>It is fairly common for firewalls to drop ICMP echo packets addressed - to machines behind the firewall. If that is your policy, please create - an exception for such packets arriving via an IPsec tunnel, at least - during intial testing of those tunnels.</P> -</DD> -<DT>destination unreachable (type 3)</DT> -<DD>This is used, with code 4 (Fragmentation Needed and Don't Fragment - was Set) in the code field, to control<A href="glossary.html#pathMTU"> - path MTU discovery</A>. Since IPsec processing adds headers, enlarges - packets and may cause fragmentation, an IPsec gateway should be able to - send and receive these ICMP messages<STRONG> on both inside and outside - interfaces</STRONG>.</DD> -</DL> -<H3><A name="traceroute">UDP packets for traceroute</A></H3> -<P>The traceroute(1) utility uses UDP port numbers from 33434 to - approximately 33633. Generally, these should be allowed through for - troubleshooting.</P> -<P>Some firewalls drop these packets to prevent outsiders exploring the - protected network with traceroute(1). If that is your policy, consider - creating an exception for such packets arriving via an IPsec tunnel, at - least during intial testing of those tunnels.</P> -<H3><A name="l2tp">UDP for L2TP</A></H3> -<P> Windows 2000 does, and products designed for compatibility with it - may, build<A href="glossary.html#L2TP"> L2TP</A> tunnels over IPsec - connections.</P> -<P>For this to work, you must allow UDP protocol 1701 packets coming out - of your tunnels to continue to their destination. You can, and probably - should, block such packets to or from your external interfaces, but - allow them from<VAR> ipsec0</VAR>.</P> -<P>See also our Windows 2000<A href="interop.html#win2k"> interoperation - discussion</A>.</P> -<H2><A name="packets">How it all works: IPsec packet details</A></H2> -<P>IPsec uses three main types of packet:</P> -<DL> -<DT><A href="glossary.html#IKE">IKE</A> uses<STRONG> the UDP protocol - and port 500</STRONG>.</DT> -<DD>Unless you are using only (less secure, not recommended) manual - keying, you need IKE to negotiate connection parameters, acceptable - algorithms, key sizes and key setup. IKE handles everything required to - set up, rekey, repair or tear down IPsec connections.</DD> -<DT><A href="glossary.html#ESP">ESP</A> is<STRONG> protocol number 50</STRONG> -</DT> -<DD>This is required for encrypted connections.</DD> -<DT><A href="glossary.html#AH">AH</A> is<STRONG> protocol number 51</STRONG> -</DT> -<DD>This can be used where only authentication, not encryption, is - required.</DD> -</DL> -<P>All of those packets should have appropriate IPsec gateway addresses - in both the to and from IP header fields. Firewall rules can check this - if you wish, though it is not strictly necessary. This is discussed in - more detail<A href="#unknowngate"> later</A>.</P> -<P>IPsec processing of incoming packets authenticates them then removes - the ESP or AH header and decrypts if necessary. Successful processing - exposes an inner packet which is then delivered back to the firewall - machinery, marked as having arrived on an<VAR> ipsec[0-3]</VAR> - interface. Firewall rules can use that interface label to distinguish - these packets from unencrypted packets which are labelled with the - physical interface they arrived on (or perhaps with a non-IPsec virtual - interface such as<VAR> ppp0</VAR>).</P> -<P>One of our users sent a mailing list message with a<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/12/msg00006.html"> - diagram</A> of the packet flow.</P> -<H3><A name="noport">ESP and AH do not have ports</A></H3> -<P>Some protocols, such as TCP and UDP, have the notion of ports. Others - protocols, including ESP and AH, do not. Quite a few IPsec newcomers - have become confused on this point. There are no ports<EM> in</EM> the - ESP or AH protocols, and no ports used<EM> for</EM> them. For these - protocols,<EM> the idea of ports is completely irrelevant</EM>.</P> -<H3><A name="header">Header layout</A></H3> -<P>The protocol numbers for ESP or AH are used in the 'next header' - field of the IP header. On most non-IPsec packets, that field would - have one of:</P> -<UL> -<LI>1 for ICMP</LI> -<LI>4 for IP-in-IP encapsulation</LI> -<LI>6 for TCP</LI> -<LI>17 for UDP</LI> -<LI>... or one of about 100 other possibilities listed by<A href="http://www.iana.org"> - IANA</A></LI> -</UL> -<P>Each header in the sequence tells what the next header will be. IPsec - adds headers for ESP or AH near the beginning of the sequence. The - original headers are kept and the 'next header' fields adjusted so that - all headers can be correctly interpreted.</P> -<P>For example, using<STRONG> [</STRONG><STRONG> ]</STRONG> to indicate - data protected by ESP and unintelligible to an eavesdropper between the - gateways:</P> -<UL> -<LI>a simple packet might have only IP and TCP headers with: -<UL> -<LI>IP header says next header --> TCP</LI> -<LI>TCP header port number --> which process to send data to</LI> -<LI>data</LI> -</UL> -</LI> -<LI>with ESP<A href="glossary.html#transport"> transport mode</A> - encapsulation, that packet would have: -<UL> -<LI>IP header says next header --> ESP</LI> -<LI>ESP header<STRONG> [</STRONG> says next --> TCP</LI> -<LI>TCP header port number --> which process to send data to</LI> -<LI>data<STRONG> ]</STRONG></LI> -</UL> - Note that the IP header is outside ESP protection, visible to an - attacker, and that the final destination must be the gateway.</LI> -<LI>with ESP in<A href="glossary.html#tunnel"> tunnel mode</A>, we might - have: -<UL> -<LI>IP header says next header --> ESP</LI> -<LI>ESP header<STRONG> [</STRONG> says next --> IP</LI> -<LI>IP header says next header --> TCP</LI> -<LI>TCP header port number --> which process to send data to</LI> -<LI>data<STRONG> ]</STRONG></LI> -</UL> - Here the inner IP header is protected by ESP, unreadable by an - attacker. Also, the inner header can have a different IP address than - the outer IP header, so the decrypted packet can be routed from the - IPsec gateway to a final destination which may be another machine.</LI> -</UL> -<P>Part of the ESP header itself is encrypted, which is why the<STRONG> - [</STRONG> indicating protected data appears in the middle of some - lines above. The next header field of the ESP header is protected. This - makes<A href="glossary.html#traffic"> traffic analysis</A> more - difficult. The next header field would tell an eavesdropper whether - your packet was UDP to the gateway, TCP to the gateway, or encapsulated - IP. It is better not to give this information away. A clever attacker - may deduce some of it from the pattern of packet sizes and timings, but - we need not make it easy.</P> -<P>IPsec allows various combinations of these to match local policies, - including combinations that use both AH and ESP headers or that nest - multiple copies of these headers.</P> -<P>For example, suppose my employer has an IPsec VPN running between two - offices so all packets travelling between the gateways for those - offices are encrypted. If gateway policies allow it (The admins could - block UDP 500 and protocols 50 and 51 to disallow it), I can build an - IPsec tunnel from my desktop to a machine in some remote office. Those - packets will have one ESP header throughout their life, for my - end-to-end tunnel. For part of the route, however, they will also have - another ESP layer for the corporate VPN's encapsulation. The whole - header scheme for a packet on the Internet might be:</P> -<UL> -<LI>IP header (with gateway address) says next header --> ESP</LI> -<LI>ESP header<STRONG> [</STRONG> says next --> IP</LI> -<LI>IP header (with receiving machine address) says next header --> ESP</LI> -<LI>ESP header<STRONG> [</STRONG> says next --> TCP</LI> -<LI>TCP header port number --> which process to send data to</LI> -<LI>data<STRONG> ]]</STRONG></LI> -</UL> -<P>The first ESP (outermost) header is for the corporate VPN. The inner - ESP header is for the secure machine-to-machine link.</P> -<H3><A name="dhr">DHR on the updown script</A></H3> -<P>Here are some mailing list comments from<A href="manpage.d/ipsec_pluto.8.html"> - pluto(8)</A> developer Hugh Redelmeier on an earlier draft of this - document:</P> -<PRE>There are many important things left out - -- firewalling is important but must reflect (implement) policy. Since - policy isn't the same for all our customers, and we're not experts, - we should concentrate on FW and MASQ interactions with FreeS/WAN. - -- we need a diagram to show packet flow WITHIN ONE MACHINE, assuming - IKE, IPsec, FW, and MASQ are all done on that machine. The flow is - obvious if the components are run on different machines (trace the - cables). - - IKE input: - + packet appears on public IF, as UDP port 500 - + input firewalling rules are applied (may discard) - + Pluto sees the packet. - - IKE output: - + Pluto generates the packet & writes to public IF, UDP port 500 - + output firewalling rules are applied (may discard) - + packet sent out public IF - - IPsec input, with encapsulated packet, outer destination of this host: - + packet appears on public IF, protocol 50 or 51. If this - packet is the result of decapsulation, it will appear - instead on the paired ipsec IF. - + input firewalling rules are applied (but packet is opaque) - + KLIPS decapsulates it, writes result to paired ipsec IF - + input firewalling rules are applied to resulting packet - as input on ipsec IF - + if the destination of the packet is this machine, the - packet is passed on to the appropriate protocol handler. - If the original packet was encapsulated more than once - and the new outer destination is this machine, that - handler will be KLIPS. - + otherwise: - * routing is done for the resulting packet. This may well - direct it into KLIPS for encoding or encrypting. What - happens then is described elsewhere. - * forwarding firewalling rules are applied - * output firewalling rules are applied - * the packet is sent where routing specified - - IPsec input, with encapsulated packet, outer destination of another host: - + packet appears on some IF, protocol 50 or 51 - + input firewalling rules are applied (but packet is opaque) - + routing selects where to send the packet - + forwarding firewalling rules are applied (but packet is opaque) - + packet forwarded, still encapsulated - - IPsec output, from this host or from a client: - + if from a client, input firewalling rules are applied as the - packet arrives on the private IF - + routing directs the packet to an ipsec IF (this is how the - system decides KLIPS processing is required) - + if from a client, forwarding firewalling rules are applied - + KLIPS eroute mechanism matches the source and destination - to registered eroutes, yielding a SPI group. This dictates - processing, and where the resulting packet is to be sent - (the destinations SG and the nexthop). - + output firewalling is not applied to the resulting - encapsulated packet - -- Until quite recently, KLIPS would double encapsulate packets that - didn't strictly need to be. Firewalling should be prepared for - those packets showing up as ESP and AH protocol input packets on - an ipsec IF. - -- MASQ processing seems to be done as if it were part of the - forwarding firewall processing (this should be verified). - -- If a firewall is being used, it is likely the case that it needs to - be adjusted whenever IPsec SAs are added or removed. Pluto invokes - a script to do this (and to adjust routing) at suitable times. The - default script is only suitable for ipfwadm-managed firewalls. Under - LINUX 2.2.x kernels, ipchains can be managed by ipfwadm (emulation), - but ipchains more powerful if manipulated using the ipchains command. - In this case, a custom updown script must be used. - - We think that the flexibility of ipchains precludes us supplying an - updown script that would be widely appropriate.</PRE> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="manpages.html">Previous</A> -<A HREF="trouble.html">Next</A> -</BODY> -</HTML> diff --git a/doc/glossary.html b/doc/glossary.html deleted file mode 100644 index 3ca33810f..000000000 --- a/doc/glossary.html +++ /dev/null @@ -1,2132 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="web.html">Previous</A> -<A HREF="biblio.html">Next</A> -<HR> -<H1><A name="ourgloss">Glossary for the Linux FreeS/WAN project</A></H1> -<P>Entries are in alphabetical order. Some entries are only one line or - one paragraph long. Others run to several paragraphs. I have tried to - put the essential information in the first paragraph so you can skip - the other paragraphs if that seems appropriate.</P> -<HR> -<H2><A name="jump">Jump to a letter in the glossary</A></H2> -<CENTER> <BIG><B><A href="#0">numeric</A><A href="#A"> A</A><A href="#B"> - B</A><A href="#C"> C</A><A href="#D"> D</A><A href="#E"> E</A><A href="#F"> - F</A><A href="#G"> G</A><A href="#H"> H</A><A href="#I"> I</A><A href="#J"> - J</A><A href="#K"> K</A><A href="#L"> L</A><A href="#M"> M</A><A href="#N"> - N</A><A href="#O"> O</A><A href="#P"> P</A><A href="#Q"> Q</A><A href="#R"> - R</A><A href="#S"> S</A><A href="#T"> T</A><A href="#U"> U</A><A href="#V"> - V</A><A href="#W"> W</A><A href="#X"> X</A><A href="#Y"> Y</A><A href="#Z"> - Z</A></B></BIG></CENTER> -<HR> -<H2><A name="gloss">Other glossaries</A></H2> -<P>Other glossaries which overlap this one include:</P> -<UL> -<LI>The VPN Consortium's glossary of<A href="http://www.vpnc.org/terms.html"> - VPN terms</A>.</LI> -<LI>glossary portion of the<A href="http://www.rsa.com/rsalabs/faq/B.html"> - Cryptography FAQ</A></LI> -<LI>an extensive crytographic glossary on<A href="http://www.ciphersbyritter.com/GLOSSARY.HTM"> - Terry Ritter's</A> page.</LI> -<LI>The<A href="#NSA"> NSA</A>'s<A href="http://www.sans.org/newlook/resources/glossary.htm"> - glossary of computer security</A> on the<A href="http://www.sans.org"> - SANS Institute</A> site.</LI> -<LI>a small glossary for Internet Security at<A href="http://www5.zdnet.com/pcmag/pctech/content/special/glossaries/internetsecurity.html"> - PC magazine</A></LI> -<LI>The<A href="http://www.visi.com/crypto/inet-crypto/glossary.html"> - glossary</A> from Richard Smith's book<A href="biblio.html#Smith"> - Internet Cryptography</A></LI> -</UL> -<P>Several Internet glossaries are available as RFCs:</P> -<UL> -<LI><A href="http://www.rfc-editor.org/rfc/rfc1208.txt">Glossary of - Networking Terms</A></LI> -<LI><A href="http://www.rfc-editor.org/rfc/rfc1983.txt">Internet User's - Glossary</A></LI> -<LI><A href="http://www.rfc-editor.org/rfc/rfc2828.txt">Internet - Security Glossary</A></LI> -</UL> -<P>More general glossary or dictionary information:</P> -<UL> -<LI>Free Online Dictionary of Computing (FOLDOC) -<UL> -<LI><A href="http://www.nightflight.com/foldoc">North America</A></LI> -<LI><A href="http://wombat.doc.ic.ac.uk/foldoc/index.html">Europe</A></LI> -<LI><A href="http://www.nue.org/foldoc/index.html">Japan</A></LI> -</UL> -<P>There are many more mirrors of this dictionary.</P> -</LI> -<LI>The Jargon File, the definitive resource for hacker slang and - folklore -<UL> -<LI><A href="http://www.netmeg.net/jargon">North America</A></LI> -<LI><A href="http://info.wins.uva.nl/~mes/jargon/">Holland</A></LI> -<LI><A href="http://www.tuxedo.org/~esr/jargon">home page</A></LI> -</UL> -<P>There are also many mirrors of this. See the home page for a list.</P> -</LI> -<LI>A general<A href="http://www.trinity.edu/~rjensen/245glosf.htm#Navigate"> - technology glossary</A></LI> -<LI>An<A href="http://www.yourdictionary.com/"> online dictionary - resource page</A> with pointers to many dictionaries for many languages</LI> -<LI>A<A href="http://www.onelook.com/"> search engine</A> that accesses - several hundred online dictionaries</LI> -<LI>O'Reilly<A href="http://www.ora.com/reference/dictionary/"> - Dictionary of PC Hardware and Data Communications Terms</A></LI> -<LI><A href="http://www.FreeSoft.org/CIE/index.htm">Connected</A> - Internet encyclopedia</LI> -<LI><A href="http://www.whatis.com/">whatis.com</A></LI> -</UL> -<HR> -<H2><A name="definitions">Definitions</A></H2> -<DL> -<DT><A name="0">0</A></DT> -<DT><A name="3DES">3DES (Triple DES)</A></DT> -<DD>Using three<A href="#DES"> DES</A> encryptions on a single data - block, with at least two different keys, to get higher security than is - available from a single DES pass. The three-key version of 3DES is the - default encryption algorithm for<A href="web.html#FreeSWAN"> Linux - FreeS/WAN</A>. -<P><A href="#IPSEC">IPsec</A> always does 3DES with three different - keys, as required by RFC 2451. For an explanation of the two-key - variant, see<A href="#2key"> two key triple DES</A>. Both use an<A href="#EDE"> - EDE</A> encrypt-decrypt-encrpyt sequence of operations.</P> -<P>Single<A href="#DES"> DES</A> is<A href="politics.html#desnotsecure"> - insecure</A>.</P> -<P>Double DES is ineffective. Using two 56-bit keys, one might expect an - attacker to have to do 2<SUP>112</SUP> work to break it. In fact, only - 2<SUP>57</SUP> work is required with a<A href="#meet"> - meet-in-the-middle attack</A>, though a large amount of memory is also - required. Triple DES is vulnerable to a similar attack, but that just - reduces the work factor from the 2<SUP>168</SUP> one might expect to 2<SUP> -112</SUP>. That provides adequate protection against<A href="#brute"> - brute force</A> attacks, and no better attack is known.</P> -<P>3DES can be somewhat slow compared to other ciphers. It requires - three DES encryptions per block. DES was designed for hardware - implementation and includes some operations which are difficult in - software. However, the speed we get is quite acceptable for many uses. - See our<A href="performance.html"> performance</A> document for - details.</P> -</DD> -<DT><A name="A">A</A></DT> -<DT><A name="active">Active attack</A></DT> -<DD>An attack in which the attacker does not merely eavesdrop (see<A href="#passive"> - passive attack</A>) but takes action to change, delete, reroute, add, - forge or divert data. Perhaps the best-known active attack is<A href="#middle"> - man-in-the-middle</A>. In general,<A href="#authentication"> - authentication</A> is a useful defense against active attacks.</DD> -<DT><A name="AES">AES</A></DT> -<DD>The<B> A</B>dvanced<B> E</B>ncryption<B> S</B>tandard -- a new<A href="#block"> - block cipher</A> standard to replace<A href="politics.html#desnotsecure"> - DES</A> -- developed by<A href="#NIST"> NIST</A>, the US National - Institute of Standards and Technology. DES used 64-bit blocks and a - 56-bit key. AES ciphers use a 128-bit block and 128, 192 or 256-bit - keys. The larger block size helps resist<A href="#birthday"> birthday - attacks</A> while the large key size prevents<A href="#brute"> brute - force attacks</A>. -<P>Fifteen proposals meeting NIST's basic criteria were submitted in - 1998 and subjected to intense discussion and analysis, "round one" - evaluation. In August 1999, NIST narrowed the field to five "round two" - candidates:</P> -<UL> -<LI><A href="http://www.research.ibm.com/security/mars.html">Mars</A> - from IBM</LI> -<LI><A href="http://www.rsa.com/rsalabs/aes/">RC6</A> from RSA</LI> -<LI><A href="http://www.esat.kuleuven.ac.be/~rijmen/rijndael/">Rijndael</A> - from two Belgian researchers</LI> -<LI><A href="http://www.cl.cam.ac.uk/~rja14/serpent.html">Serpent</A>, a - British-Norwegian-Israeli collaboration</LI> -<LI><A href="http://www.counterpane.com/twofish.html">Twofish</A> from - the consulting firm<A href="http://www.counterpane.com"> Counterpane</A> -</LI> -</UL> -<P>Three of the five finalists -- Rijndael, Serpent and Twofish -- have - completely open licenses.</P> -<P>In October 2000, NIST announced the winner -- Rijndael.</P> -<P>For more information, see:</P> -<UL> -<LI>NIST's<A href="http://csrc.nist.gov/encryption/aes/aes_home.htm"> - AES home page</A></LI> -<LI>the Block Cipher Lounge<A href="http://www.ii.uib.no/~larsr/aes.html"> - AES page</A></LI> -<LI>Brian Gladman's<A href="http://fp.gladman.plus.com/cryptography_technology/index.htm"> - code and benchmarks</A></LI> -<LI>Helger Lipmaa's<A href="http://www.tcs.hut.fi/~helger/aes/"> survey - of implementations</A></LI> -</UL> -<P>AES will be added to a future release of<A href="web.html#FreeSWAN"> - Linux FreeS/WAN</A>. Likely we will add all three of the finalists with - good licenses. User-written<A href="web.html#patch"> AES patches</A> - are already available.</P> -<P>Adding AES may also require adding stronger hashes,<A href="#SHA-256"> - SHA-256, SHA-384 and SHA-512</A>.</P> -</DD> -<DT><A name="AH">AH</A></DT> -<DD>The<A href="#IPSEC"> IPsec</A><B> A</B>uthentication<B> H</B>eader, - added after the IP header. For details, see our<A href="ipsec.html#AH.ipsec"> - IPsec</A> document and/or RFC 2402.</DD> -<DT><A name="alicebob">Alice and Bob</A></DT> -<DD>A and B, the standard example users in writing on cryptography and - coding theory. Carol and Dave join them for protocols which require - more players. -<P>Bruce Schneier extends these with many others such as Eve the - Eavesdropper and Victor the Verifier. His extensions seem to be in the - process of becoming standard as well. See page 23 of<A href="biblio.html#schneier"> - Applied Cryptography</A></P> -<P>Alice and Bob have an amusing<A href="http://www.conceptlabs.co.uk/alicebob.html"> - biography</A> on the web.</P> -</DD> -<DT>ARPA</DT> -<DD>see<A href="#DARPA"> DARPA</A></DD> -<DT><A name="ASIO">ASIO</A></DT> -<DD>Australian Security Intelligence Organisation.</DD> -<DT>Asymmetric cryptography</DT> -<DD>See<A href="#public"> public key cryptography</A>.</DD> -<DT><A name="authentication">Authentication</A></DT> -<DD>Ensuring that a message originated from the expected sender and has - not been altered on route.<A href="#IPSEC"> IPsec</A> uses - authentication in two places: -<UL> -<LI>peer authentication, authenticating the players in<A href="#IKE"> - IKE</A>'s<A href="#DH"> Diffie-Hellman</A> key exchanges to prevent<A href="#middle"> - man-in-the-middle attacks</A>. This can be done in a number of ways. - The methods supported by FreeS/WAN are discussed in our<A href="adv_config.html#choose"> - advanced configuration</A> document.</LI> -<LI>packet authentication, authenticating packets on an established<A href="#SA"> - SA</A>, either with a separate<A href="#AH"> authentication header</A> - or with the optional authentication in the<A href="#ESP"> ESP</A> - protocol. In either case, packet authentication uses a<A href="#HMAC"> - hashed message athentication code</A> technique.</LI> -</UL> -<P>Outside IPsec, passwords are perhaps the most common authentication - mechanism. Their function is essentially to authenticate the person's - identity to the system. Passwords are generally only as secure as the - network they travel over. If you send a cleartext password over a - tapped phone line or over a network with a packet sniffer on it, the - security provided by that password becomes zero. Sending an encrypted - password is no better; the attacker merely records it and reuses it at - his convenience. This is called a<A href="#replay"> replay</A> attack.</P> -<P>A common solution to this problem is a<A href="#challenge"> - challenge-response</A> system. This defeats simple eavesdropping and - replay attacks. Of course an attacker might still try to break the - cryptographic algorithm used, or the<A href="#random"> random number</A> - generator.</P> -</DD> -<DT><A name="auto">Automatic keying</A></DT> -<DD>A mode in which keys are automatically generated at connection - establisment and new keys automaically created periodically thereafter. - Contrast with<A href="ipsec.html#manual"> manual keying</A> in which a - single stored key is used. -<P>IPsec uses the<A href="#DH"> Diffie-Hellman key exchange protocol</A> - to create keys. An<A href="#authentication"> authentication</A> - mechansim is required for this. FreeS/WAN normally uses<A href="#RSA"> - RSA</A> for this. Other methods supported are discussed in our<A href="adv_config.html#choose"> - advanced configuration</A> document.</P> -<P>Having an attacker break the authentication is emphatically not a - good idea. An attacker that breaks authentication, and manages to - subvert some other network entities (DNS, routers or gateways), can use - a<A href="#middle"> man-in-the middle attack</A> to break the security - of your IPsec connections.</P> -<P>However, having an attacker break the authentication in automatic - keying is not quite as bad as losing the key in manual keying.</P> -<UL> -<LI>An attacker who reads /etc/ipsec.conf and gets the keys for a - manually keyed connection can, without further effort, read all - messages encrypted with those keys, including any old messages he may - have archived.</LI> -<LI>Automatic keying has a property called<A href="#PFS"> perfect - forward secrecy</A>. An attacker who breaks the authentication gets - none of the automatically generated keys and cannot immediately read - any messages. He has to mount a successful<A href="#middle"> - man-in-the-middle attack</A> in real time before he can read anything. - He cannot read old archived messages at all and will not be able to - read any future messages not caught by man-in-the-middle tricks.</LI> -</UL> -<P>That said, the secrets used for authentication, stored in<A href="manpage.d/ipsec.secrets.5.html"> - ipsec.secrets(5)</A>, should still be protected as tightly as - cryptographic keys.</P> -</DD> -<DT><A name="B">B</A></DT> -<DT><A href="http://www.nortelnetworks.com">Bay Networks</A></DT> -<DD>A vendor of routers, hubs and related products, now a subsidiary of - Nortel. Interoperation between their IPsec products and Linux FreeS/WAN - was problematic at last report; see our<A href="interop.html#bay"> - interoperation</A> section.</DD> -<DT><A name="benchmarks">benchmarks</A></DT> -<DD>Our default block cipher,<A href="#3DES"> triple DES</A>, is slower - than many alternate ciphers that might be used. Speeds achieved, - however, seem adequate for many purposes. For example, the assembler - code from the<A href="#LIBDES"> LIBDES</A> library we use encrypts 1.6 - megabytes per second on a Pentium 200, according to the test program - supplied with the library. -<P>For more detail, see our document on<A href="performance.html"> - FreeS/WAN performance</A>.</P> -</DD> -<DT><A name="BIND">BIND</A></DT> -<DD><B>B</B>erkeley<B> I</B>nternet<B> N</B>ame<B> D</B>aemon, a widely - used implementation of<A href="ipsec.html#DNS"> DNS</A> (Domain Name - Service). See our bibliography for a<A href="ipsec.html#DNS"> useful - reference</A>. See the<A href="http://www.isc.org/bind.html"> BIND home - page</A> for more information and the latest version.</DD> -<DT><A name="birthday">Birthday attack</A></DT> -<DD>A cryptographic attack based on the mathematics exemplified by the<A href="#paradox"> - birthday paradox</A>. This math turns up whenever the question of two - cryptographic operations producing the same result becomes an issue: -<UL> -<LI><A href="#collision">collisions</A> in<A href="#digest"> message - digest</A> functions.</LI> -<LI>identical output blocks from a<A href="#block"> block cipher</A></LI> -<LI>repetition of a challenge in a<A href="#challenge"> - challenge-response</A> system</LI> -</UL> -<P>Resisting such attacks is part of the motivation for:</P> -<UL> -<LI>hash algorithms such as<A href="#SHA"> SHA</A> and<A href="#RIPEMD"> - RIPEMD-160</A> giving a 160-bit result rather than the 128 bits of<A href="#MD4"> - MD4</A>,<A href="#MD5"> MD5</A> and<A href="#RIPEMD"> RIPEMD-128</A>.</LI> -<LI><A href="#AES">AES</A> block ciphers using a 128-bit block instead - of the 64-bit block of most current ciphers</LI> -<LI><A href="#IPSEC">IPsec</A> using a 32-bit counter for packets sent - on an<A href="ipsec.html#auto"> automatically keyed</A><A href="#SA"> - SA</A> and requiring that the connection always be rekeyed before the - counter overflows.</LI> -</UL> -</DD> -<DT><A name="paradox">Birthday paradox</A></DT> -<DD>Not really a paradox, just a rather counter-intuitive mathematical - fact. In a group of 23 people, the chance of a least one pair having - the same birthday is over 50%. -<P>The second person has 1 chance in 365 (ignoring leap years) of - matching the first. If they don't match, the third person's chances of - matching one of them are 2/365. The 4th, 3/365, and so on. The total of - these chances grows more quickly than one might guess.</P> -</DD> -<DT><A name="block">Block cipher</A></DT> -<DD>A<A href="#symmetric"> symmetric cipher</A> which operates on - fixed-size blocks of plaintext, giving a block of ciphertext for each. - Contrast with<A href="#stream"> stream cipher</A>. Block ciphers can be - used in various<A href="#mode"> modes</A> when multiple block are to be - encrypted. -<P><A href="#DES">DES</A> is among the the best known and widely used - block ciphers, but is now obsolete. Its 56-bit key size makes it<A href="politics.html#desnotsecure"> - highly insecure</A> today.<A href="#3DES"> Triple DES</A> is the - default block cipher for<A href="web.html#FreeSWAN"> Linux FreeS/WAN</A> -.</P> -<P>The current generation of block ciphers -- such as<A href="#Blowfish"> - Blowfish</A>,<A href="#CAST128"> CAST-128</A> and<A href="#IDEA"> IDEA</A> - -- all use 64-bit blocks and 128-bit keys. The next generation,<A href="#AES"> - AES</A>, uses 128-bit blocks and supports key sizes up to 256 bits.</P> -<P>The<A href="http://www.ii.uib.no/~larsr/bc.html"> Block Cipher Lounge</A> - web site has more information.</P> -</DD> -<DT><A name="Blowfish">Blowfish</A></DT> -<DD>A<A href="#block"> block cipher</A> using 64-bit blocks and keys of - up to 448 bits, designed by<A href="biblio.html#schneier"> Bruce - Schneier</A> and used in several products. -<P>This is not required by the<A href="#IPSEC"> IPsec</A> RFCs and not - currently used in<A href="web.html#FreeSWAN"> Linux FreeS/WAN</A>.</P> -</DD> -<DT><A name="brute">Brute force attack (exhaustive search)</A></DT> -<DD>Breaking a cipher by trying all possible keys. This is always - possible in theory (except against a<A href="#OTP"> one-time pad</A>), - but it becomes practical only if the key size is inadequate. For an - important example, see our document on the<A href="politics.html#desnotsecure"> - insecurity of DES</A> with its 56-bit key. For an analysis of key sizes - required to resist plausible brute force attacks, see<A href="http://www.counterpane.com/keylength.html"> - this paper</A>. -<P>Longer keys protect against brute force attacks. Each extra bit in - the key doubles the number of possible keys and therefore doubles the - work a brute force attack must do. A large enough key defeats<STRONG> - any</STRONG> brute force attack.</P> -<P>For example, the EFF's<A href="#EFF"> DES Cracker</A> searches a - 56-bit key space in an average of a few days. Let us assume an attacker - that can find a 64-bit key (256 times harder) by brute force search in - a second (a few hundred thousand times faster). For a 96-bit key, that - attacker needs 2<SUP>32</SUP> seconds, about 135 years. Against a - 128-bit key, he needs 2<SUP>32</SUP> times that, over 500,000,000,000 - years. Your data is then obviously secure against brute force attacks. - Even if our estimate of the attacker's speed is off by a factor of a - million, it still takes him over 500,000 years to crack a message.</P> -<P>This is why</P> -<UL> -<LI>single<A href="#DES"> DES</A> is now considered<A href="politics.html#desnotsecure"> - dangerously insecure</A></LI> -<LI>all of the current generation of<A href="#block"> block ciphers</A> - use a 128-bit or longer key</LI> -<LI><A href="#AES">AES</A> ciphers support keysizes 128, 192 and 256 - bits</LI> -<LI>any cipher we add to Linux FreeS/WAN will have<EM> at least</EM> a - 128-bit key</LI> -</UL> -<P><STRONG>Cautions:</STRONG> -<BR><EM> Inadequate keylength always indicates a weak cipher</EM> but it - is important to note that<EM> adequate keylength does not necessarily - indicate a strong cipher</EM>. There are many attacks other than brute - force, and adequate keylength<EM> only</EM> guarantees resistance to - brute force. Any cipher, whatever its key size, will be weak if design - or implementation flaws allow other attacks.</P> -<P>Also,<EM> once you have adequate keylength</EM> (somewhere around 90 - or 100 bits),<EM> adding more key bits make no practical difference</EM> -, even against brute force. Consider our 128-bit example above that - takes 500,000,000,000 years to break by brute force. We really don't - care how many zeroes there are on the end of that, as long as the - number remains ridiculously large. That is, we don't care exactly how - large the key is as long as it is large enough.</P> -<P>There may be reasons of convenience in the design of the cipher to - support larger keys. For example<A href="#Blowfish"> Blowfish</A> - allows up to 448 bits and<A href="#RC4"> RC4</A> up to 2048, but beyond - 100-odd bits it makes no difference to practical security.</P> -</DD> -<DT>Bureau of Export Administration</DT> -<DD>see<A href="#BXA"> BXA</A></DD> -<DT><A name="BXA">BXA</A></DT> -<DD>The US Commerce Department's<B> B</B>ureau of E<B>x</B>port<B> A</B> -dministration which administers the<A href="#EAR"> EAR</A> Export - Administration Regulations controling the export of, among other - things, cryptography.</DD> -<DT><A name="C">C</A></DT> -<DT><A name="CA">CA</A></DT> -<DD><B>C</B>ertification<B> A</B>uthority, an entity in a<A href="#PKI"> - public key infrastructure</A> that can certify keys by signing them. - Usually CAs form a hierarchy. The top of this hierarchy is called the<A href="#rootCA"> - root CA</A>. -<P>See<A href="#web"> Web of Trust</A> for an alternate model.</P> -</DD> -<DT><A name="CAST128">CAST-128</A></DT> -<DD>A<A href="#block"> block cipher</A> using 64-bit blocks and 128-bit - keys, described in RFC 2144 and used in products such as<A href="#Entrust"> - Entrust</A> and recent versions of<A href="#PGP"> PGP</A>. -<P>This is not required by the<A href="#IPSEC"> IPsec</A> RFCs and not - currently used in<A href="web.html#FreeSWAN"> Linux FreeS/WAN</A>.</P> -</DD> -<DT>CAST-256</DT> -<DD><A href="#Entrust">Entrust</A>'s candidate cipher for the<A href="#AES"> - AES standard</A>, largely based on the<A href="#CAST128"> CAST-128</A> - design.</DD> -<DT><A name="CBC">CBC mode</A></DT> -<DD><B>C</B>ipher<B> B</B>lock<B> C</B>haining<A href="#mode"> mode</A>, - a method of using a<A href="#block"> block cipher</A> in which for each - block except the first, the result of the previous encryption is XORed - into the new block before it is encrypted. CBC is the mode used in<A href="#IPSEC"> - IPsec</A>. -<P>An<A href="#IV"> initialisation vector</A> (IV) must be provided. It - is XORed into the first block before encryption. The IV need not be - secret but should be different for each message and unpredictable.</P> -</DD> -<DT><A name="CIDR">CIDR</A></DT> -<DD><B>C</B>lassless<B> I</B>nter-<B>D</B>omain<B> R</B>outing, an - addressing scheme used to describe networks not restricted to the old - Class A, B, and C sizes. A CIDR block is written<VAR> address</VAR>/<VAR> -mask</VAR>, where<VAR> address</VAR> is a 32-bit Internet address. The - first<VAR> mask</VAR> bits of<VAR> address</VAR> are part of the - gateway address, while the remaining bits designate other host - addresses. For example, the CIDR block 192.0.2.96/27 describes a - network with gateway 192.0.2.96, hosts 192.0.2.96 through 192.0.2.126 - and broadcast 192.0.2.127. -<P>FreeS/WAN policy group files accept CIDR blocks of the format<VAR> - address</VAR>/[<VAR>mask</VAR>], where<VAR> address</VAR> may take the - form<VAR> name.domain.tld</VAR>. An absent<VAR> mask</VAR> is assumed - to be /32.</P> -</DD> -<DT>Certification Authority</DT> -<DD>see<A href="#CA"> CA</A></DD> -<DT><A name="challenge">Challenge-response authentication</A></DT> -<DD>An<A href="#authentication"> authentication</A> system in which one - player generates a<A href="#random"> random number</A>, encrypts it and - sends the result as a challenge. The other player decrypts and sends - back the result. If the result is correct, that proves to the first - player that the second player knew the appropriate secret, required for - the decryption. Variations on this technique exist using<A href="#public"> - public key</A> or<A href="#symmetric"> symmetric</A> cryptography. Some - provide two-way authentication, assuring each player of the other's - identity. -<P>This is more secure than passwords against two simple attacks:</P> -<UL> -<LI>If cleartext passwords are sent across the wire (e.g. for telnet), - an eavesdropper can grab them. The attacker may even be able to break - into other systems if the user has chosen the same password for them.</LI> -<LI>If an encrypted password is sent, an attacker can record the - encrypted form and use it later. This is called a replay attack.</LI> -</UL> -<P>A challenge-response system never sends a password, either cleartext - or encrypted. An attacker cannot record the response to one challenge - and use it as a response to a later challenge. The random number is - different each time.</P> -<P>Of course an attacker might still try to break the cryptographic - algorithm used, or the<A href="#random"> random number</A> generator.</P> -</DD> -<DT><A name="mode">Cipher Modes</A></DT> -<DD>Different ways of using a block cipher when encrypting multiple - blocks. -<P>Four standard modes were defined for<A href="#DES"> DES</A> in<A href="#FIPS"> - FIPS</A> 81. They can actually be applied with any block cipher.</P> -<TABLE><TBODY></TBODY> -<TR><TD></TD><TD><A href="#ECB">ECB</A></TD><TD>Electronic CodeBook</TD><TD> -encrypt each block independently</TD></TR> -<TR><TD></TD><TD><A href="#CBC">CBC</A></TD><TD>Cipher Block Chaining -<BR></TD><TD>XOR previous block ciphertext into new block plaintext - before encrypting new block</TD></TR> -<TR><TD></TD><TD>CFB</TD><TD>Cipher FeedBack</TD><TD></TD></TR> -<TR><TD></TD><TD>OFB</TD><TD>Output FeedBack</TD><TD></TD></TR> -</TABLE> -<P><A href="#IPSEC">IPsec</A> uses<A href="#CBC"> CBC</A> mode since - this is only marginally slower than<A href="#ECB"> ECB</A> and is more - secure. In ECB mode the same plaintext always encrypts to the same - ciphertext, unless the key is changed. In CBC mode, this does not - occur.</P> -<P>Various other modes are also possible, but none of them are used in - IPsec.</P> -</DD> -<DT><A name="ciphertext">Ciphertext</A></DT> -<DD>The encrypted output of a cipher, as opposed to the unencrypted<A href="#plaintext"> - plaintext</A> input.</DD> -<DT><A href="http://www.cisco.com">Cisco</A></DT> -<DD>A vendor of routers, hubs and related products. Their IPsec products - interoperate with Linux FreeS/WAN; see our<A href="interop.html#Cisco"> - interop</A> section.</DD> -<DT><A name="client">Client</A></DT> -<DD>This term has at least two distinct uses in discussing IPsec: -<UL> -<LI>The<STRONG> clients of an IPsec gateway</STRONG> are the machines it - protects, typically on one or more subnets behind the gateway. In this - usage, all the machines on an office network are clients of that - office's IPsec gateway. Laptop or home machines connecting to the - office, however, are<EM> not</EM> clients of that gateway. They are - remote gateways, running the other end of an IPsec connection. Each of - them is also its own client.</LI> -<LI><STRONG>IPsec client software</STRONG> is used to describe software - which runs on various standalone machines to let them connect to IPsec - networks. In this usage, a laptop or home machine connecting to the - office is a client, and the office gateway is the server.</LI> -</UL> -<P>We generally use the term in the first sense. Vendors of Windows - IPsec solutions often use it in the second. See this<A href="interop.html#client.server"> - discussion</A>.</P> -</DD> -<DT><A name="cc">Common Criteria</A></DT> -<DD>A set of international security classifications which are replacing - the old US<A href="#rainbow"> Rainbow Book</A> standards and similar - standards in other countries. -<P>Web references include this<A href="http://csrc.nist.gov/cc"> US - government site</A> and this<A href="http://www.commoncriteria.org"> - global home page</A>.</P> -</DD> -<DT>Conventional cryptography</DT> -<DD>See<A href="#symmetric"> symmetric cryptography</A></DD> -<DT><A name="collision">Collision resistance</A></DT> -<DD>The property of a<A href="#digest"> message digest</A> algorithm - which makes it hard for an attacker to find or construct two inputs - which hash to the same output.</DD> -<DT>Copyleft</DT> -<DD>see GNU<A href="#GPL"> General Public License</A></DD> -<DT><A name="CSE">CSE</A></DT> -<DD><A href="http://www.cse-cst.gc.ca/">Communications Security - Establishment</A>, the Canadian organisation for<A href="#SIGINT"> - signals intelligence</A>.</DD> -<DT><A name="D">D</A></DT> -<DT><A name="DARPA">DARPA (sometimes just ARPA)</A></DT> -<DD>The US government's<B> D</B>efense<B> A</B>dvanced<B> R</B>esearch<B> - P</B>rojects<B> A</B>gency. Projects they have funded over the years - have included the Arpanet which evolved into the Internet, the TCP/IP - protocol suite (as a replacement for the original Arpanet suite), the - Berkeley 4.x BSD Unix projects, and<A href="#SDNS"> Secure DNS</A>. -<P>For current information, see their<A href="http://www.darpa.mil/ito"> - web site</A>.</P> -</DD> -<DT><A name="DOS">Denial of service (DoS) attack</A></DT> -<DD>An attack that aims at denying some service to legitimate users of a - system, rather than providing a service to the attacker. -<UL> -<LI>One variant is a flooding attack, overwhelming the system with too - many packets, to much email, or whatever.</LI> -<LI>A closely related variant is a resource exhaustion attack. For - example, consider a "TCP SYN flood" attack. Setting up a TCP connection - involves a three-packet exchange: -<UL> -<LI>Initiator: Connection please (SYN)</LI> -<LI>Responder: OK (ACK)</LI> -<LI>Initiator: OK here too</LI> -</UL> -<P>If the attacker puts bogus source information in the first packet, - such that the second is never delivered, the responder may wait a long - time for the third to come back. If responder has already allocated - memory for the connection data structures, and if many of these bogus - packets arrive, the responder may run out of memory.</P> -</LI> -<LI>Another variant is to feed the system undigestible data, hoping to - make it sick. For example, IP packets are limited in size to 64K bytes - and a fragment carries information on where it starts within that 64K - and how long it is. The "ping of death" delivers fragments that say, - for example, that they start at 60K and are 20K long. Attempting to - re-assemble these without checking for overflow can be fatal.</LI> -</UL> -<P>The two example attacks discussed were both quite effective when - first discovered, capable of crashing or disabling many operating - systems. They were also well-publicised, and today far fewer systems - are vulnerable to them.</P> -</DD> -<DT><A name="DES">DES</A></DT> -<DD>The<B> D</B>ata<B> E</B>ncryption<B> S</B>tandard, a<A href="#block"> - block cipher</A> with 64-bit blocks and a 56-bit key. Probably the most - widely used<A href="#symmetric"> symmetric cipher</A> ever devised. DES - has been a US government standard for their own use (only for - unclassified data), and for some regulated industries such as banking, - since the late 70's. It is now being replaced by<A href="#AES"> AES</A> -. -<P><A href="politics.html#desnotsecure">DES is seriously insecure - against current attacks.</A></P> -<P><A href="web.html#FreeSWAN">Linux FreeS/WAN</A> does not include DES, - even though the RFCs specify it.<B> We strongly recommend that single - DES not be used.</B></P> -<P>See also<A href="#3DES"> 3DES</A> and<A href="#DESX"> DESX</A>, - stronger ciphers based on DES.</P> -</DD> -<DT><A name="DESX">DESX</A></DT> -<DD>An improved<A href="#DES"> DES</A> suggested by Ron Rivest of RSA - Data Security. It XORs extra key material into the text before and - after applying the DES cipher. -<P>This is not required by the<A href="#IPSEC"> IPsec</A> RFCs and not - currently used in<A href="web.html#FreeSWAN"> Linux FreeS/WAN</A>. DESX - would be the easiest additional transform to add; there would be very - little code to write. It would be much faster than 3DES and almost - certainly more secure than DES. However, since it is not in the RFCs - other IPsec implementations cannot be expected to have it.</P> -</DD> -<DT>DH</DT> -<DD>see<A href="#DH"> Diffie-Hellman</A></DD> -<DT><A name="DHCP">DHCP</A></DT> -<DD><STRONG>D</STRONG>ynamic<STRONG> H</STRONG>ost<STRONG> C</STRONG> -onfiguration<STRONG> P</STRONG>rotocol, a method of assigning<A href="#dynamic"> - dynamic IP addresses</A>, and providing additional information such as - addresses of DNS servers and of gateways. See this<A href="http://www.dhcp.org"> - DHCP resource page.</A></DD> -<DT><A name="DH">Diffie-Hellman (DH) key exchange protocol</A></DT> -<DD>A protocol that allows two parties without any initial shared secret - to create one in a manner immune to eavesdropping. Once they have done - this, they can communicate privately by using that shared secret as a - key for a block cipher or as the basis for key exchange. -<P>The protocol is secure against all<A href="#passive"> passive attacks</A> -, but it is not at all resistant to active<A href="#middle"> - man-in-the-middle attacks</A>. If a third party can impersonate Bob to - Alice and vice versa, then no useful secret can be created. - Authentication of the participants is a prerequisite for safe - Diffie-Hellman key exchange. IPsec can use any of several<A href="#authentication"> - authentication</A> mechanisims. Those supported by FreeS/WAN are - discussed in our<A href="config.html#choose"> configuration</A> - section.</P> -<P>The Diffie-Hellman key exchange is based on the<A href="#dlog"> - discrete logarithm</A> problem and is secure unless someone finds an - efficient solution to that problem.</P> -<P>Given a prime<VAR> p</VAR> and generator<VAR> g</VAR> (explained - under<A href="#dlog"> discrete log</A> below), Alice:</P> -<UL> -<LI>generates a random number<VAR> a</VAR></LI> -<LI>calculates<VAR> A = g^a modulo p</VAR></LI> -<LI>sends<VAR> A</VAR> to Bob</LI> -</UL> -<P>Meanwhile Bob:</P> -<UL> -<LI>generates a random number<VAR> b</VAR></LI> -<LI>calculates<VAR> B = g^b modulo p</VAR></LI> -<LI>sends<VAR> B</VAR> to Alice</LI> -</UL> -<P>Now Alice and Bob can both calculate the shared secret<VAR> s = - g^(ab)</VAR>. Alice knows<VAR> a</VAR> and<VAR> B</VAR>, so she - calculates<VAR> s = B^a</VAR>. Bob knows<VAR> A</VAR> and<VAR> b</VAR> - so he calculates<VAR> s = A^b</VAR>.</P> -<P>An eavesdropper will know<VAR> p</VAR> and<VAR> g</VAR> since these - are made public, and can intercept<VAR> A</VAR> and<VAR> B</VAR> but, - short of solving the<A href="#dlog"> discrete log</A> problem, these do - not let him or her discover the secret<VAR> s</VAR>.</P> -</DD> -<DT><A name="signature">Digital signature</A></DT> -<DD>Sender: -<UL> -<LI>calculates a<A href="#digest"> message digest</A> of a document</LI> -<LI>encrypts the digest with his or her private key, using some<A href="#public"> - public key cryptosystem</A>.</LI> -<LI>attaches the encrypted digest to the document as a signature</LI> -</UL> -<P>Receiver:</P> -<UL> -<LI>calculates a digest of the document (not including the signature)</LI> -<LI>decrypts the signature with the signer's public key</LI> -<LI>verifies that the two results are identical</LI> -</UL> -<P>If the public-key system is secure and the verification succeeds, - then the receiver knows</P> -<UL> -<LI>that the document was not altered between signing and verification</LI> -<LI>that the signer had access to the private key</LI> -</UL> -<P>Such an encrypted message digest can be treated as a signature since - it cannot be created without<EM> both</EM> the document<EM> and</EM> - the private key which only the sender should possess. The<A href="web.html#legal"> - legal issues</A> are complex, but several countries are moving in the - direction of legal recognition for digital signatures.</P> -</DD> -<DT><A name="dlog">discrete logarithm problem</A></DT> -<DD>The problem of finding logarithms in a finite field. Given a field - defintion (such definitions always include some operation analogous to - multiplication) and two numbers, a base and a target, find the power - which the base must be raised to in order to yield the target. -<P>The discrete log problem is the basis of several cryptographic - systems, including the<A href="#DH"> Diffie-Hellman</A> key exchange - used in the<A href="#IKE"> IKE</A> protocol. The useful property is - that exponentiation is relatively easy but the inverse operation, - finding the logarithm, is hard. The cryptosystems are designed so that - the user does only easy operations (exponentiation in the field) but an - attacker must solve the hard problem (discrete log) to crack the - system.</P> -<P>There are several variants of the problem for different types of - field. The IKE/Oakley key determination protocol uses two variants, - either over a field modulo a prime or over a field defined by an - elliptic curve. We give an example modulo a prime below. For the - elliptic curve version, consult an advanced text such as<A href="biblio.html#handbook"> - Handbook of Applied Cryptography</A>.</P> -<P>Given a prime<VAR> p</VAR>, a generator<VAR> g</VAR> for the field - modulo that prime, and a number<VAR> x</VAR> in the field, the problem - is to find<VAR> y</VAR> such that<VAR> g^y = x</VAR>.</P> -<P>For example, let p = 13. The field is then the integers from 0 to 12. - Any integer equals one of these modulo 13. That is, the remainder when - any integer is divided by 13 must be one of these.</P> -<P>2 is a generator for this field. That is, the powers of two modulo 13 - run through all the non-zero numbers in the field. Modulo 13 we have:</P> -<PRE> y x - 2^0 == 1 - 2^1 == 2 - 2^2 == 4 - 2^3 == 8 - 2^4 == 3 that is, the remainder from 16/13 is 3 - 2^5 == 6 the remainder from 32/13 is 6 - 2^6 == 12 and so on - 2^7 == 11 - 2^8 == 9 - 2^9 == 5 - 2^10 == 10 - 2^11 == 7 - 2^12 == 1</PRE> -<P>Exponentiation in such a field is not difficult. Given, say,<NOBR><VAR> - y = 11</VAR>,calculating<NOBR><VAR> x = 7</VAR>is straightforward. One - method is just to calculate<NOBR><VAR> 2^11 = 2048</VAR>,then<NOBR><VAR> - 2048 mod 13 == 7</VAR>.When the field is modulo a large prime (say a - few 100 digits) you need a silghtly cleverer method and even that is - moderately expensive in computer time, but the calculation is still not - problematic in any basic way.</P> -<P>The discrete log problem is the reverse. In our example, given<NOBR><VAR> - x = 7</VAR>,find the logarithm<NOBR><VAR> y = 11</VAR>.When the field - is modulo a large prime (or is based on a suitable elliptic curve), - this is indeed problematic. No solution method that is not - catastrophically expensive is known. Quite a few mathematicians have - tackled this problem. No efficient method has been found and - mathematicians do not expect that one will be. It seems likely no - efficient solution to either of the main variants the discrete log - problem exists.</P> -<P>Note, however, that no-one has proven such methods do not exist. If a - solution to either variant were found, the security of any crypto - system using that variant would be destroyed. This is one reason<A href="#IKE"> - IKE</A> supports two variants. If one is broken, we can switch to the - other.</P> -</DD> -<DT><A name="discretionary">discretionary access control</A></DT> -<DD>access control mechanisms controlled by the user, for example Unix - rwx file permissions. These contrast with<A href="#mandatory"> - mandatory access controls</A>.</DD> -<DT><A name="DNS">DNS</A></DT> -<DD><B>D</B>omain<B> N</B>ame<B> S</B>ervice, a distributed database - through which names are associated with numeric addresses and other - information in the Internet Protocol Suite. See also the<A href="background.html#dns.background"> - DNS background</A> section of our documentation.</DD> -<DT>DOS attack</DT> -<DD>see<A href="#DOS"> Denial Of Service</A> attack</DD> -<DT><A name="dynamic">dynamic IP address</A></DT> -<DD>an IP address which is automatically assigned, either by<A href="#DHCP"> - DHCP</A> or by some protocol such as<A href="#PPP"> PPP</A> or<A href="#PPPoE"> - PPPoE</A> which the machine uses to connect to the Internet. This is - the opposite of a<A href="#static"> static IP address</A>, pre-set on - the machine itself.</DD> -<DT><A name="E">E</A></DT> -<DT><A name="EAR">EAR</A></DT> -<DD>The US government's<B> E</B>xport<B> A</B>dministration<B> R</B> -egulations, administered by the<A href="#BXA"> Bureau of Export - Administration</A>. These have replaced the earlier<A href="#ITAR"> - ITAR</A> regulations as the controls on export of cryptography.</DD> -<DT><A name="ECB">ECB mode</A></DT> -<DD><B>E</B>lectronic<B> C</B>ode<B>B</B>ook mode, the simplest way to - use a block cipher. See<A href="#mode"> Cipher Modes</A>.</DD> -<DT><A name="EDE">EDE</A></DT> -<DD>The sequence of operations normally used in either the three-key - variant of<A href="#3DES"> triple DES</A> used in<A href="#IPSEC"> - IPsec</A> or the<A href="#2key"> two-key</A> variant used in some other - systems. -<P>The sequence is:</P> -<UL> -<LI><B>E</B>ncrypt with key1</LI> -<LI><B>D</B>ecrypt with key2</LI> -<LI><B>E</B>ncrypt with key3</LI> -</UL> -<P>For the two-key version, key1=key3.</P> -<P>The "advantage" of this EDE order of operations is that it makes it - simple to interoperate with older devices offering only single DES. Set - key1=key2=key3 and you have the worst of both worlds, the overhead of - triple DES with the "security" of single DES. Since both the<A href="politics.html#desnotsecure"> - security of single DES</A> and the overheads of triple DES are - seriously inferior to many other ciphers, this is a spectacularly - dubious "advantage".</P> -</DD> -<DT><A name="Entrust">Entrust</A></DT> -<DD>A Canadian company offerring enterprise<A href="#PKI"> PKI</A> - products using<A href="#CAST128"> CAST-128</A> symmetric crypto,<A href="#RSA"> - RSA</A> public key and<A href="#X509"> X.509</A> directories.<A href="http://www.entrust.com"> - Web site</A></DD> -<DT><A name="EFF">EFF</A></DT> -<DD><A href="http://www.eff.org">Electronic Frontier Foundation</A>, an - advocacy group for civil rights in cyberspace.</DD> -<DT><A name="encryption">Encryption</A></DT> -<DD>Techniques for converting a readable message (<A href="#plaintext"> -plaintext</A>) into apparently random material (<A href="#ciphertext"> -ciphertext</A>) which cannot be read if intercepted. A key is required - to read the message. -<P>Major variants include<A href="#symmetric"> symmetric</A> encryption - in which sender and receiver use the same secret key and<A href="#public"> - public key</A> methods in which the sender uses one of a matched pair - of keys and the receiver uses the other. Many current systems, - including<A href="#IPSEC"> IPsec</A>, are<A href="#hybrid"> hybrids</A> - combining the two techniques.</P> -</DD> -<DT><A name="ESP">ESP</A></DT> -<DD><B>E</B>ncapsulated<B> S</B>ecurity<B> P</B>ayload, the<A href="#IPSEC"> - IPsec</A> protocol which provides<A href="#encryption"> encryption</A>. - It can also provide<A href="#authentication"> authentication</A> - service and may be used with null encryption (which we do not - recommend). For details see our<A href="ipsec.html#ESP.ipsec"> IPsec</A> - document and/or RFC 2406.</DD> -<DT><A name="#extruded">Extruded subnet</A></DT> -<DD>A situation in which something IP sees as one network is actually in - two or more places. -<P>For example, the Internet may route all traffic for a particular - company to that firm's corporate gateway. It then becomes the company's - problem to get packets to various machines on their<A href="#subnet"> - subnets</A> in various departments. They may decide to treat a branch - office like a subnet, giving it IP addresses "on" their corporate net. - This becomes an extruded subnet.</P> -<P>Packets bound for it are delivered to the corporate gateway, since as - far as the outside world is concerned, that subnet is part of the - corporate network. However, instead of going onto the corporate LAN (as - they would for, say, the accounting department) they are then - encapsulated and sent back onto the Internet for delivery to the branch - office.</P> -<P>For information on doing this with Linux FreeS/WAN, look in our<A href="adv_config.html#extruded.config"> - advanced configuration</A> section.</P> -</DD> -<DT>Exhaustive search</DT> -<DD>See<A href="#brute"> brute force attack</A>.</DD> -<DT><A name="F">F</A></DT> -<DT><A name="FIPS">FIPS</A></DT> -<DD><B>F</B>ederal<B> I</B>nformation<B> P</B>rocessing<B> S</B>tandard, - the US government's standards for products it buys. These are issued by<A -href="#NIST"> NIST</A>. Among other things,<A href="#DES"> DES</A> and<A href="#SHA"> - SHA</A> are defined in FIPS documents. NIST have a<A href="http://www.itl.nist.gov/div897/pubs"> - FIPS home page</A>.</DD> -<DT><A name="FSF">Free Software Foundation (FSF)</A></DT> -<DD>An organisation to promote free software, free in the sense of these - quotes from their web pages</DD> -<DD><BLOCKQUOTE> "Free software" is a matter of liberty, not price. To - understand the concept, you should think of "free speech", not "free - beer." -<P>"Free software" refers to the users' freedom to run, copy, - distribute, study, change and improve the software.</P> -</BLOCKQUOTE> -<P>See also<A href="#GNU"> GNU</A>,<A href="#GPL"> GNU General Public - License</A>, and<A href="http://www.fsf.org"> the FSF site</A>.</P> -</DD> -<DT>FreeS/WAN</DT> -<DD>see<A href="web.html#FreeSWAN"> Linux FreeS/WAN</A></DD> -<DT><A name="fullnet">Fullnet</A></DT> -<DD>The CIDR block containing all IPs of its IP version. The<A HREF="#IPv4"> - IPv4</A> fullnet is written 0.0.0.0/0. Also known as "all" and - "default", fullnet may be used in a routing table to specify a default - route, and in a FreeS/WAN<A HREF="policygroups.html#policygroups"> - policy group</A> file to specify a default IPsec policy.</DD> -<DT>FSF</DT> -<DD>see<A href="#FSF"> Free software Foundation</A></DD> -<DT><A name="G">G</A></DT> -<DT><A name="GCHQ">GCHQ</A></DT> -<DD><A href="http://www.gchq.gov.uk">Government Communications - Headquarters</A>, the British organisation for<A href="#SIGINT"> - signals intelligence</A>.</DD> -<DT>generator of a prime field</DT> -<DD>see<A href="#dlog"> discrete logarithm problem</A></DD> -<DT><A name="GILC">GILC</A></DT> -<DD><A href="http://www.gilc.org">Global Internet Liberty Campaign</A>, - an international organisation advocating, among other things, free - availability of cryptography. They have a<A href="http://www.gilc.org/crypto/wassenaar"> - campaign</A> to remove cryptographic software from the<A href="#Wassenaar.gloss"> - Wassenaar Arrangement</A>.</DD> -<DT>Global Internet Liberty Campaign</DT> -<DD>see<A href="#GILC"> GILC</A>.</DD> -<DT><A name="GTR">Global Trust Register</A></DT> -<DD>An attempt to create something like a<A href="#rootCA"> root CA</A> - for<A href="#PGP"> PGP</A> by publishing both<A href="biblio.html#GTR"> - as a book</A> and<A href="http://www.cl.cam.ac.uk/Research/Security/Trust-Register"> - on the web</A> the fingerprints of a set of verified keys for - well-known users and organisations.</DD> -<DT><A name="GMP">GMP</A></DT> -<DD>The<B> G</B>NU<B> M</B>ulti-<B>P</B>recision library code, used in<A href="web.html#FreeSWAN"> - Linux FreeS/WAN</A> by<A href="#Pluto"> Pluto</A> for<A href="#public"> - public key</A> calculations. See the<A href="http://www.swox.com/gmp"> - GMP home page</A>.</DD> -<DT><A name="GNU">GNU</A></DT> -<DD><B>G</B>NU's<B> N</B>ot<B> U</B>nix, the<A href="#FSF"> Free - Software Foundation's</A> project aimed at creating a free system with - at least the capabilities of Unix.<A href="#Linux"> Linux</A> uses GNU - utilities extensively.</DD> -<DT><A name="#GOST">GOST</A></DT> -<DD>a Soviet government standard<A href="#block"> block cipher</A>.<A href="biblio.html#schneier"> - Applied Cryptography</A> has details.</DD> -<DT>GPG</DT> -<DD>see<A href="#GPG"> GNU Privacy Guard</A></DD> -<DT><A name="GPL">GNU General Public License</A>(GPL, copyleft)</DT> -<DD>The license developed by the<A href="#FSF"> Free Software Foundation</A> - under which<A href="#Linux"> Linux</A>,<A href="web.html#FreeSWAN"> - Linux FreeS/WAN</A> and many other pieces of software are distributed. - The license allows anyone to redistribute and modify the code, but - forbids anyone from distributing executables without providing access - to source code. For more details see the file<A href="../COPYING"> - COPYING</A> included with GPLed source distributions, including ours, - or<A href="http://www.fsf.org/copyleft/gpl.html"> the GNU site's GPL - page</A>.</DD> -<DT><A name="GPG">GNU Privacy Guard</A></DT> -<DD>An open source implementation of Open<A href="#PGP"> PGP</A> as - defined in RFC 2440. See their<A href="http://www.gnupg.org"> web site</A> -</DD> -<DT>GPL</DT> -<DD>see<A href="#GPL"> GNU General Public License</A>.</DD> -<DT><A name="H">H</A></DT> -<DT><A name="hash">Hash</A></DT> -<DD>see<A href="#digest"> message digest</A></DD> -<DT><A name="HMAC">Hashed Message Authentication Code (HMAC)</A></DT> -<DD>using keyed<A href="#digest"> message digest</A> functions to - authenticate a message. This differs from other uses of these - functions: -<UL> -<LI>In normal usage, the hash function's internal variable are - initialised in some standard way. Anyone can reproduce the hash to - check that the message has not been altered.</LI> -<LI>For HMAC usage, you initialise the internal variables from the key. - Only someone with the key can reproduce the hash. A successful check of - the hash indicates not only that the message is unchanged but also that - the creator knew the key.</LI> -</UL> -<P>The exact techniques used in<A href="#IPSEC"> IPsec</A> are defined - in RFC 2104. They are referred to as HMAC-MD5-96 and HMAC-SHA-96 - because they output only 96 bits of the hash. This makes some attacks - on the hash functions harder.</P> -</DD> -<DT>HMAC</DT> -<DD>see<A href="#HMAC"> Hashed Message Authentication Code</A></DD> -<DT>HMAC-MD5-96</DT> -<DD>see<A href="#HMAC"> Hashed Message Authentication Code</A></DD> -<DT>HMAC-SHA-96</DT> -<DD>see<A href="#HMAC"> Hashed Message Authentication Code</A></DD> -<DT><A name="hybrid">Hybrid cryptosystem</A></DT> -<DD>A system using both<A href="#public"> public key</A> and<A href="#symmetric"> - symmetric cipher</A> techniques. This works well. Public key methods - provide key management and<A href="#signature"> digital signature</A> - facilities which are not readily available using symmetric ciphers. The - symmetric cipher, however, can do the bulk of the encryption work much - more efficiently than public key methods.</DD> -<DT><A name="I">I</A></DT> -<DT><A name="IAB">IAB</A></DT> -<DD><A href="http://www.iab.org/iab">Internet Architecture Board</A>.</DD> -<DT><A name="ICMP.gloss">ICMP</A></DT> -<DD><STRONG>I</STRONG>nternet<STRONG> C</STRONG>ontrol<STRONG> M</STRONG> -essage<STRONG> P</STRONG>rotocol. This is used for various IP-connected - devices to manage the network.</DD> -<DT><A name="IDEA">IDEA</A></DT> -<DD><B>I</B>nternational<B> D</B>ata<B> E</B>ncrypion<B> A</B>lgorithm, - developed in Europe as an alternative to exportable American ciphers - such as<A href="#DES"> DES</A> which were<A href="politics.html#desnotsecure"> - too weak for serious use</A>. IDEA is a<A href="#block"> block cipher</A> - using 64-bit blocks and 128-bit keys, and is used in products such as<A href="#PGP"> - PGP</A>. -<P>IDEA is not required by the<A href="#IPSEC"> IPsec</A> RFCs and not - currently used in<A href="web.html#FreeSWAN"> Linux FreeS/WAN</A>.</P> -<P>IDEA is patented and, with strictly limited exceptions for personal - use, using it requires a license from<A href="http://www.ascom.com"> - Ascom</A>.</P> -</DD> -<DT><A name="IEEE">IEEE</A></DT> -<DD><A href="http://www.ieee.org">Institute of Electrical and Electronic - Engineers</A>, a professional association which, among other things, - sets some technical standards</DD> -<DT><A name="IESG">IESG</A></DT> -<DD><A href="http://www.iesg.org">Internet Engineering Steering Group</A> -.</DD> -<DT><A name="IETF">IETF</A></DT> -<DD><A href="http://www.ietf.org">Internet Engineering Task Force</A>, - the umbrella organisation whose various working groups make most of the - technical decisions for the Internet. The IETF<A href="http://www.ietf.org/html.charters/ipsec-charter.html"> - IPsec working group</A> wrote the<A href="rfc.html#RFC"> RFCs</A> we - are implementing.</DD> -<DT><A name="IKE">IKE</A></DT> -<DD><B>I</B>nternet<B> K</B>ey<B> E</B>xchange, based on the<A href="#DH"> - Diffie-Hellman</A> key exchange protocol. For details, see RFC 2409 and - our<A href="ipsec.html"> IPsec</A> document. IKE is implemented in<A href="web.html#FreeSWAN"> - Linux FreeS/WAN</A> by the<A href="#Pluto"> Pluto daemon</A>.</DD> -<DT>IKE v2</DT> -<DD>A proposed replacement for<A href="#IKE"> IKE</A>. There are other - candidates, such as<A href="#JFK"> JFK</A>, and at time of writing - (March 2002) the choice between them has not yet been made and does not - appear imminent.</DD> -<DT><A name="iOE">iOE</A></DT> -<DD>See<A HREF="#initiate-only"> Initiate-only opportunistic encryption</A> -.</DD> -<DT><A name="IP">IP</A></DT> -<DD><B>I</B>nternet<B> P</B>rotocol.</DD> -<DT><A name="masq">IP masquerade</A></DT> -<DD>A mostly obsolete term for a method of allowing multiple machines to - communicate over the Internet when only one IP address is available for - their use. The more current term is Network Address Translation or<A href="#NAT.gloss"> - NAT</A>.</DD> -<DT><A name="IPng">IPng</A></DT> -<DD>"IP the Next Generation", see<A href="#ipv6.gloss"> IPv6</A>.</DD> -<DT><A name="IPv4">IPv4</A></DT> -<DD>The current version of the<A href="#IP"> Internet protocol suite</A> -.</DD> -<DT><A name="ipv6.gloss">IPv6 (IPng)</A></DT> -<DD>Version six of the<A href="#IP"> Internet protocol suite</A>, - currently being developed. It will replace the current<A href="#IPv4"> - version four</A>. IPv6 has<A href="#IPSEC"> IPsec</A> as a mandatory - component. -<P>See this<A href="http://playground.sun.com/pub/ipng/html/ipng-main.html"> - web site</A> for more details, and our<A href="compat.html#ipv6"> - compatibility</A> document for information on FreeS/WAN and the Linux - implementation of IPv6.</P> -</DD> -<DT><A name="IPSEC">IPsec</A> or IPSEC</DT> -<DD><B>I</B>nternet<B> P</B>rotocol<B> SEC</B>urity, security functions - (<A href="#authentication">authentication</A> and<A href="#encryption"> - encryption</A>) implemented at the IP level of the protocol stack. It - is optional for<A href="#IPv4"> IPv4</A> and mandatory for<A href="#ipv6.gloss"> - IPv6</A>. -<P>This is the standard<A href="web.html#FreeSWAN"> Linux FreeS/WAN</A> - is implementing. For more details, see our<A href="ipsec.html"> IPsec - Overview</A>. For the standards, see RFCs listed in our<A href="rfc.html#RFC"> - RFCs document</A>.</P> -</DD> -<DT><A name="IPX">IPX</A></DT> -<DD>Novell's Netware protocol tunnelled over an IP link. Our<A href="firewall.html#user.scripts"> - firewalls</A> document includes an example of using this through an - IPsec tunnel.</DD> -<DT><A name="ISAKMP">ISAKMP</A></DT> -<DD><B>I</B>nternet<B> S</B>ecurity<B> A</B>ssociation and<B> K</B>ey<B> - M</B>anagement<B> P</B>rotocol, defined in RFC 2408.</DD> -<DT><A name="ITAR">ITAR</A></DT> -<DD><B>I</B>nternational<B> T</B>raffic in<B> A</B>rms<B> R</B> -egulations, US regulations administered by the State Department which - until recently limited export of, among other things, cryptographic - technology and software. ITAR still exists, but the limits on - cryptography have now been transferred to the<A href="#EAR"> Export - Administration Regulations</A> under the Commerce Department's<A href="#BXA"> - Bureau of Export Administration</A>.</DD> -<DT>IV</DT> -<DD>see<A href="#IV"> Initialisation vector</A></DD> -<DT><A name="IV">Initialisation Vector (IV)</A></DT> -<DD>Some cipher<A href="#mode"> modes</A>, including the<A href="#CBC"> - CBC</A> mode which IPsec uses, require some extra data at the - beginning. This data is called the initialisation vector. It need not - be secret, but should be different for each message. Its function is to - prevent messages which begin with the same text from encrypting to the - same ciphertext. That might give an analyst an opening, so it is best - prevented.</DD> -<DT><A name="initiate-only">Initiate-only opportunistic encryption (iOE)</A> -</DT> -<DD>A form of<A HREF="#carpediem"> opportunistic encryption</A> (OE) in - which a host proposes opportunistic connections, but lacks the reverse - DNS records necessary to support incoming opportunistic connection - requests. Common among hosts on cable or pppoe connections where the - system administrator does not have write access to the DNS reverse map - for the host's external IP. -<P>Configuring for initiate-only opportunistic encryption is described - in our<A href="quickstart.html#opp.client"> quickstart</A> document.</P> -</DD> -<DT><A name="J">J</A></DT> -<DT><A name="JFK">JFK</A></DT> -<DD><STRONG>J</STRONG>ust<STRONG> F</STRONG>ast<STRONG> K</STRONG>eying, - a proposed simpler replacement for<A href="#IKE"> IKE.</A></DD> -<DT><A name="K">K</A></DT> -<DT><A name="kernel">Kernel</A></DT> -<DD>The basic part of an operating system (e.g. Linux) which controls - the hardware and provides services to all other programs. -<P>In the Linux release numbering system, an even second digit as in 2.<STRONG> -2</STRONG>.x indicates a stable or production kernel while an odd number - as in 2.<STRONG>3</STRONG>.x indicates an experimental or development - kernel. Most users should run a recent kernel version from the - production series. The development kernels are primarily for people - doing kernel development. Others should consider using development - kernels only if they have an urgent need for some feature not yet - available in production kernels.</P> -</DD> -<DT>Keyed message digest</DT> -<DD>See<A href="#HMAC"> HMAC</A>.</DD> -<DT>Key length</DT> -<DD>see<A href="#brute"> brute force attack</A></DD> -<DT><A name="KLIPS">KLIPS</A></DT> -<DD><B>K</B>erne<B>l</B><B> IP</B><B> S</B>ecurity, the<A href="web.html#FreeSWAN"> - Linux FreeS/WAN</A> project's changes to the<A href="#Linux"> Linux</A> - kernel to support the<A href="#IPSEC"> IPsec</A> protocols.</DD> -<DT><A name="L">L</A></DT> -<DT><A name="LDAP">LDAP</A></DT> -<DD><B>L</B>ightweight<B> D</B>irectory<B> A</B>ccess<B> P</B>rotocol, - defined in RFCs 1777 and 1778, a method of accessing information stored - in directories. LDAP is used by several<A href="#PKI"> PKI</A> - implementations, often with X.501 directories and<A href="#X509"> X.509</A> - certificates. It may also be used by<A href="#IPSEC"> IPsec</A> to - obtain key certifications from those PKIs. This is not yet implemented - in<A href="web.html#FreeSWAN"> Linux FreeS/WAN</A>.</DD> -<DT><A name="LIBDES">LIBDES</A></DT> -<DD>A publicly available library of<A href="#DES"> DES</A> code, written - by Eric Young, which<A href="web.html#FreeSWAN"> Linux FreeS/WAN</A> - uses in both<A href="#KLIPS"> KLIPS</A> and<A href="#Pluto"> Pluto</A>.</DD> -<DT><A name="Linux">Linux</A></DT> -<DD>A freely available Unix-like operating system based on a kernel - originally written for the Intel 386 architecture by (then) student - Linus Torvalds. Once his 32-bit kernel was available, the<A href="#GNU"> - GNU</A> utilities made it a usable system and contributions from many - others led to explosive growth. -<P>Today Linux is a complete Unix replacement available for several CPU - architectures -- Intel, DEC/Compaq Alpha, Power PC, both 32-bit SPARC - and the 64-bit UltraSPARC, SrongARM, . . . -- with support for multiple - CPUs on some architectures.</P> -<P><A href="web.html#FreeSWAN">Linux FreeS/WAN</A> is intended to run on - all CPUs supported by Linux and is known to work on several. See our<A href="compat.html#CPUs"> - compatibility</A> section for a list.</P> -</DD> -<DT><A name="FreeSWAN">Linux FreeS/WAN</A></DT> -<DD>Our implementation of the<A href="#IPSEC"> IPsec</A> protocols, - intended to be freely redistributable source code with<A href="#GPL"> a - GNU GPL license</A> and no constraints under US or other<A href="politics.html#exlaw"> - export laws</A>. Linux FreeS/WAN is intended to interoperate with other<A -href="#IPSEC"> IPsec</A> implementations. The name is partly taken, with - permission, from the<A href="#SWAN"> S/WAN</A> multi-vendor IPsec - compatability effort. Linux FreeS/WAN has two major components,<A href="#KLIPS"> - KLIPS</A> (KerneL IPsec Support) and the<A href="#Pluto"> Pluto</A> - daemon which manages the whole thing. -<P>See our<A href="ipsec.html"> IPsec section</A> for more detail. For - the code see our<A href="http://freeswan.org"> primary site</A> or one - of the mirror sites on<A href="intro.html#mirrors"> this list</A>.</P> -</DD> -<DT><A name="LSM">Linux Security Modules (LSM)</A></DT> -<DD>a project to create an interface in the Linux kernel that supports - plug-in modules for various security policies. -<P>This allows multiple security projects to take different approaches - to security enhancement without tying the kernel down to one particular - approach. As I understand the history, several projects were pressing - Linus to incorporate their changes, the various sets of changes were - incompatible, and his answer was more-or-less "a plague on all your - houses; I'll give you an interface, but I won't incorporate anything".</P> -<P>It seems to be working. There is a fairly active<A href="http://mail.wirex.com/mailman/listinfo/linux-security-module"> - LSM mailing list</A>, and several projects are already using the - interface.</P> -</DD> -<DT>LSM</DT> -<DD>see<A href="#LSM"> Linux Security Modules</A></DD> -<DT><A name="M">M</A></DT> -<DT><A name="list">Mailing list</A></DT> -<DD>The<A href="web.html#FreeSWAN"> Linux FreeS/WAN</A> project has - several public email lists for bug reports and software development - discussions. See our document on<A href="mail.html"> mailing lists</A>.</DD> -<DT><A name="middle">Man-in-the-middle attack</A></DT> -<DD>An<A href="#active"> active attack</A> in which the attacker - impersonates each of the legitimate players in a protocol to the other. -<P>For example, if<A href="#alicebob"> Alice and Bob</A> are negotiating - a key via the<A href="#DH"> Diffie-Hellman</A> key agreement, and are - not using<A href="#authentication"> authentication</A> to be certain - they are talking to each other, then an attacker able to insert himself - in the communication path can deceive both players.</P> -<P>Call the attacker Mallory. For Bob, he pretends to be Alice. For - Alice, he pretends to be Bob. Two keys are then negotiated, - Alice-to-Mallory and Bob-to-Mallory. Alice and Bob each think the key - they have is Alice-to-Bob.</P> -<P>A message from Alice to Bob then goes to Mallory who decrypts it, - reads it and/or saves a copy, re-encrypts using the Bob-to-Mallory key - and sends it along to Bob. Bob decrypts successfully and sends a reply - which Mallory decrypts, reads, re-encrypts and forwards to Alice.</P> -<P>To make this attack effective, Mallory must</P> -<UL> -<LI>subvert some part of the network in some way that lets him carry out - the deception -<BR> possible targets: DNS, router, Alice or Bob's machine, mail server, - ...</LI> -<LI>beat any authentication mechanism Alice and Bob use -<BR> strong authentication defeats the attack entirely; this is why<A href="#IKE"> - IKE</A> requires authentication</LI> -<LI>work in real time, delivering messages without introducing a delay - large enough to alert the victims -<BR> not hard if Alice and Bob are using email; quite difficult in some - situations.</LI> -</UL> -<P>If he manages it, however, it is devastating. He not only gets to - read all the messages; he can alter messages, inject his own, forge - anything he likes, . . . In fact, he controls the communication - completely.</P> -</DD> -<DT><A name="mandatory">mandatory access control</A></DT> -<DD>access control mechanisims which are not settable by the user (see<A href="#discretionary"> - discretionary access control</A>), but are enforced by the system. -<P>For example, a document labelled "secret, zebra" might be readable - only by someone with secret clearance working on Project Zebra. - Ideally, the system will prevent any transfer outside those boundaries. - For example, even if you can read it, you should not be able to e-mail - it (unless the recipient is appropriately cleared) or print it (unless - certain printers are authorised for that classification).</P> -<P>Mandatory access control is a required feature for some levels of<A href="#rainbow"> - Rainbow Book</A> or<A href="#cc"> Common Criteria</A> classification, - but has not been widely used outside the military and government. There - is a good discussion of the issues in Anderson's<A href="biblio.html#anderson"> - Security Engineering</A>.</P> -<P>The<A href="#SElinux"> Security Enhanced Linux</A> project is adding - mandatory access control to Linux.</P> -</DD> -<DT><A name="manual">Manual keying</A></DT> -<DD>An IPsec mode in which the keys are provided by the administrator. - In FreeS/WAN, they are stored in /etc/ipsec.conf. The alternative,<A href="ipsec.html#auto"> - automatic keying</A>, is preferred in most cases. See this<A href="adv_config.html#man-auto"> - discussion</A>.</DD> -<DT><A name="MD4">MD4</A></DT> -<DD><A href="#digest">Message Digest Algorithm</A> Four from Ron Rivest - of<A href="#RSAco"> RSA</A>. MD4 was widely used a few years ago, but - is now considered obsolete. It has been replaced by its descendants<A href="#MD5"> - MD5</A> and<A href="#SHA"> SHA</A>.</DD> -<DT><A name="MD5">MD5</A></DT> -<DD><A href="#digest">Message Digest Algorithm</A> Five from Ron Rivest - of<A href="#RSAco"> RSA</A>, an improved variant of his<A href="#MD4"> - MD4</A>. Like MD4, it produces a 128-bit hash. For details see RFC - 1321. -<P>MD5 is one of two message digest algorithms available in IPsec. The - other is<A href="#SHA"> SHA</A>. SHA produces a longer hash and is - therefore more resistant to<A href="#birthday"> birthday attacks</A>, - but this is not a concern for IPsec. The<A href="#HMAC"> HMAC</A> - method used in IPsec is secure even if the underlying hash is not - particularly strong against this attack.</P> -<P>Hans Dobbertin found a weakness in MD5, and people often ask whether - this means MD5 is unsafe for IPsec. It doesn't. The IPsec RFCs discuss - Dobbertin's attack and conclude that it does not affect MD5 as used for - HMAC in IPsec.</P> -</DD> -<DT><A name="meet">Meet-in-the-middle attack</A></DT> -<DD>A divide-and-conquer attack which breaks a cipher into two parts, - works against each separately, and compares results. Probably the best - known example is an attack on double DES. This applies in principle to - any pair of block ciphers, e.g. to an encryption system using, say, - CAST-128 and Blowfish, but we will describe it for double DES. -<P>Double DES encryption and decryption can be written:</P> -<PRE> C = E(k2,E(k1,P)) - P = D(k1,D(k2,C))</PRE> -<P>Where C is ciphertext, P is plaintext, E is encryption, D is - decryption, k1 is one key, and k2 is the other key. If we know a P, C - pair, we can try and find the keys with a brute force attack, trying - all possible k1, k2 pairs. Since each key is 56 bits, there are 2<SUP> -112</SUP> such pairs and this attack is painfully inefficient.</P> -<P>The meet-in-the middle attack re-writes the equations to calculate a - middle value M:</P> -<PRE> M = E(k1,P) - M = D(k2,C)</PRE> -<P>Now we can try some large number of D(k2,C) decryptions with various - values of k2 and store the results in a table. Then start doing E(k1,P) - encryptions, checking each result to see if it is in the table.</P> -<P>With enough table space, this breaks double DES with<NOBR> 2<SUP>56</SUP> - + 2<SUP>56</SUP> = 2<SUP>57</SUP>work. Against triple DES, you need<NOBR> - 2<SUP>56</SUP> + 2<SUP>112</SUP> ~= 2<SUP>112</SUP>.</P> -<P>The memory requirements for such attacks can be prohibitive, but - there is a whole body of research literature on methods of reducing - them.</P> -</DD> -<DT><A name="digest">Message Digest Algorithm</A></DT> -<DD>An algorithm which takes a message as input and produces a hash or - digest of it, a fixed-length set of bits which depend on the message - contents in some highly complex manner. Design criteria include making - it extremely difficult for anyone to counterfeit a digest or to change - a message without altering its digest. One essential property is<A href="#collision"> - collision resistance</A>. The main applications are in message<A href="#authentication"> - authentication</A> and<A href="#signature"> digital signature</A> - schemes. Widely used algorithms include<A href="#MD5"> MD5</A> and<A href="#SHA"> - SHA</A>. In IPsec, message digests are used for<A href="#HMAC"> HMAC</A> - authentication of packets.</DD> -<DT><A name="MTU">MTU</A></DT> -<DD><STRONG>M</STRONG>aximum<STRONG> T</STRONG>ransmission<STRONG> U</STRONG> -nit, the largest size of packet that can be sent over a link. This is - determined by the underlying network, but must be taken account of at - the IP level. -<P>IP packets, which can be up to 64K bytes each, must be packaged into - lower-level packets of the appropriate size for the underlying - network(s) and re-assembled on the other end. When a packet must pass - over multiple networks, each with its own MTU, and many of the MTUs are - unknown to the sender, this becomes a fairly complex problem. See<A href="#pathMTU"> - path MTU discovery</A> for details.</P> -<P>Often the MTU is a few hundred bytes on serial links and 1500 on - Ethernet. There are, however, serial link protocols which use a larger - MTU to avoid fragmentation at the ethernet/serial boundary, and newer - (especially gigabit) Ethernet networks sometimes support much larger - packets because these are more efficient in some applications.</P> -</DD> -<DT><A name="N">N</A></DT> -<DT><A name="NAI">NAI</A></DT> -<DD><A href="http://www.nai.com">Network Associates</A>, a conglomerate - formed from<A href="#PGPI"> PGP Inc.</A>, TIS (Trusted Information - Systems, a firewall vendor) and McAfee anti-virus products. Among other - things, they offer an IPsec-based VPN product.</DD> -<DT><A name="NAT.gloss">NAT</A></DT> -<DD><B>N</B>etwork<B> A</B>ddress<B> T</B>ranslation, a process by which - firewall machines may change the addresses on packets as they go - through. For discussion, see our<A href="background.html#nat.background"> - background</A> section.</DD> -<DT><A name="NIST">NIST</A></DT> -<DD>The US<A href="http://www.nist.gov"> National Institute of Standards - and Technology</A>, responsible for<A href="#FIPS"> FIPS standards</A> - including<A href="#DES"> DES</A> and its replacement,<A href="#AES"> - AES</A>.</DD> -<DT><A name="nonce">Nonce</A></DT> -<DD>A<A href="#random"> random</A> value used in an<A href="#authentication"> - authentication</A> protocol.</DD> -<DT></DT> -<DT><A name="non-routable">Non-routable IP address</A></DT> -<DD>An IP address not normally allowed in the "to" or "from" IP address - field header of IP packets. -<P>Almost invariably, the phrase "non-routable address" means one of the - addresses reserved by RFC 1918 for private networks:</P> -<UL> -<LI>10.anything</LI> -<LI>172.x.anything with 16 <= x <= 31</LI> -<LI>192.168.anything</LI> -</UL> -<P>These addresses are commonly used on private networks, e.g. behind a - Linux machines doing<A href="#masq"> IP masquerade</A>. Machines within - the private network can address each other with these addresses. All - packets going outside that network, however, have these addresses - replaced before they reach the Internet.</P> -<P>If any packets using these addresses do leak out, they do not go far. - Most routers automatically discard all such packets.</P> -<P>Various other addresses -- the 127.0.0.0/8 block reserved for local - use, 0.0.0.0, various broadcast and network addresses -- cannot be - routed over the Internet, but are not normally included in the meaning - when the phrase "non-routable address" is used.</P> -</DD> -<DT><A name="NSA">NSA</A></DT> -<DD>The US<A href="http://www.nsa.gov"> National Security Agency</A>, - the American organisation for<A href="#SIGINT"> signals intelligence</A> -, the protection of US government messages and the interception and - analysis of other messages. For details, see Bamford's<A href="biblio.html#puzzle"> - "The Puzzle Palace"</A>. -<P>Some<A href="http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB23/index.html"> - history of NSA</A> documents were declassified in response to a FOIA - (Freedom of Information Act) request.</P> -</DD> -<DT><A name="O">O</A></DT> -<DT><A name="oakley">Oakley</A></DT> -<DD>A key determination protocol, defined in RFC 2412.</DD> -<DT>Oakley groups</DT> -<DD>The groups used as the basis of<A href="#DH"> Diffie-Hellman</A> key - exchange in the Oakley protocol, and in<A href="#IKE"> IKE</A>. Four - were defined in the original RFC, and a fifth has been<A href="http://www.lounge.org/ike_doi_errata.html"> - added since</A>. -<P>Linux FreeS/WAN currently supports the three groups based on finite - fields modulo a prime (Groups 1, 2 and 5) and does not support the - elliptic curve groups (3 and 4). For a description of the difference of - the types, see<A href="#dlog"> discrete logarithms</A>.</P> -</DD> -<DT><A name="OTP">One time pad</A></DT> -<DD>A cipher in which the key is: -<UL> -<LI>as long as the total set of messages to be enciphered</LI> -<LI>absolutely<A href="#random"> random</A></LI> -<LI>never re-used</LI> -</UL> -<P>Given those three conditions, it can easily be proved that the cipher - is perfectly secure, in the sense that an attacker with intercepted - message in hand has no better chance of guessing the message than an - attacker who has not intercepted the message and only knows the message - length. No such proof exists for any other cipher.</P> -<P>There are, however, several problems with this "perfect" cipher.</P> -<P>First, it is<STRONG> wildly impractical</STRONG> for most - applications. Key management is at best difficult, often completely - impossible.</P> -<P>Second, it is<STRONG> extremely fragile</STRONG>. Small changes which - violate the conditions listed above do not just weaken the cipher - liitle. Quite often they destroy its security completely.</P> -<UL> -<LI>Re-using the pad weakens the cipher to the point where it can be - broken with pencil and paper. With a computer, the attack is trivially - easy.</LI> -<LI>Using<EM> anything</EM> less than truly<A href="#random"> random</A> - numbers<EM> completely</EM> invalidates the security proof.</LI> -<LI>In particular, using computer-generated pseudo-random numbers may - give an extremely weak cipher. It might also produce a good stream - cipher, if the pseudo-random generator is both well-designed and - properely seeded.</LI> -</UL> -<P>Marketing claims about the "unbreakable" security of various products - which somewhat resemble one-time pads are common. Such claims are one - of the surest signs of cryptographic<A href="#snake"> snake oil</A>; - most systems marketed with such claims are worthless.</P> -<P>Finally, even if the system is implemented and used correctly, it is<STRONG> - highly vulnerable to a substitution attack</STRONG>. If an attacker - knows some plaintext and has an intercepted message, he can discover - the pad.</P> -<UL> -<LI>This does not matter if the attacker is just a<A href="#passive"> - passive</A> eavesdropper. It gives him no plaintext he didn't already - know and we don't care that he learns a pad which we will never re-use.</LI> -<LI>However, an<A href="#active"> active</A> attacker who knows the - plaintext can recover the pad, then use it to encode with whatever he - chooses. If he can get his version delivered instead of yours, this may - be a disaster. If you send "attack at dawn", the delivered message can - be anything the same length -- perhaps "retreat to east" or "shoot - generals".</LI> -<LI>An active attacker with only a reasonable guess at the plaintext can - try the same attack. If the guess is correct, this works and the - attacker's bogus message is delivered. If the guess is wrong, a garbled - message is delivered.</LI> -</UL> -<P>In general then, despite its theoretical perfection, the one-time-pad - has very limited practical application.</P> -<P>See also the<A href="http://pubweb.nfr.net/~mjr/pubs/otpfaq/"> one - time pad FAQ</A>.</P> -</DD> -<DT><A name="carpediem">Opportunistic encryption (OE)</A></DT> -<DD>A situation in which any two IPsec-aware machines can secure their - communications, without a pre-shared secret and without a common<A href="#PKI"> - PKI</A> or previous exchange of public keys. This is one of the goals - of the Linux FreeS/WAN project, discussed in our<A href="intro.html#goals"> - introduction</A> section. -<P>Setting up for opportunistic encryption is described in our<A href="quickstart.html#quickstart"> - quickstart</A> document.</P> -</DD> -<DT><A name="responder">Opportunistic responder</A></DT> -<DD>A host which accepts, but does not initiate, requests for<A HREF="#carpediem"> - opportunistic encryption</A> (OE). An opportunistic responder has - enabled OE in its<A HREF="#passive.OE"> passive</A> form (pOE) only. A - web server or file server may be usefully set up as an opportunistic - responder. -<P>Configuring passive OE is described in our<A href="policygroups.html#policygroups"> - policy groups</A> document.</P> -</DD> -<DT><A name="orange">Orange book</A></DT> -<DD>the most basic and best known of the US government's<A href="#rainbow"> - Rainbow Book</A> series of computer security standards.</DD> -<DT><A name="P">P</A></DT> -<DT><A name="P1363">P1363 standard</A></DT> -<DD>An<A href="#IEEE"> IEEE</A> standard for public key cryptography.<A href="http://grouper.ieee.org/groups/1363"> - Web page</A>.</DD> -<DT><A name="pOE">pOE</A></DT> -<DD>See<A href="#passive.OE"> Passive opportunistic encryption</A>.</DD> -<DT><A name="passive">Passive attack</A></DT> -<DD>An attack in which the attacker only eavesdrops and attempts to - analyse intercepted messages, as opposed to an<A href="#active"> active - attack</A> in which he diverts messages or generates his own.</DD> -<DT><A name="passive.OE">Passive opportunistic encryption (pOE)</A></DT> -<DD>A form of<A HREF="#carpediem"> opportunistic encryption</A> (OE) in - which the host will accept opportunistic connection requests, but will - not initiate such requests. A host which runs OE in its passive form - only is known as an<A HREF="#responder"> opportunistic responder</A>. -<P>Configuring passive OE is described in our<A href="policygroups.html#policygroups"> - policy groups</A> document.</P> -</DD> -<DT><A name="pathMTU">Path MTU discovery</A></DT> -<DD>The process of discovering the largest packet size which all links - on a path can handle without fragmentation -- that is, without any - router having to break the packet up into smaller pieces to match the<A href="#MTU"> - MTU</A> of its outgoing link. -<P>This is done as follows:</P> -<UL> -<LI>originator sends the largest packets allowed by<A href="#MTU"> MTU</A> - of the first link, setting the DF (<STRONG>d</STRONG>on't<STRONG> f</STRONG> -ragment) bit in the packet header</LI> -<LI>any router which cannot send the packet on (outgoing MTU is too - small for it, and DF prevents fragmenting it to match) sends back an<A href="#ICMP.gloss"> - ICMP</A> packet reporting the problem</LI> -<LI>originator looks at ICMP message and tries a smaller size</LI> -<LI>eventually, you settle on a size that can pass all routers</LI> -<LI>thereafter, originator just sends that size and no-one has to - fragment</LI> -</UL> -<P>Since this requires co-operation of many systems, and since the next - packet may travel a different path, this is one of the trickier areas - of IP programming. Bugs that have shown up over the years have - included:</P> -<UL> -<LI>malformed ICMP messages</LI> -<LI>hosts that ignore or mishandle these ICMP messages</LI> -<LI>firewalls blocking the ICMP messages so host does not see them</LI> -</UL> -<P>Since IPsec adds a header, it increases packet size and may require - fragmentation even where incoming and outgoing MTU are equal.</P> -</DD> -<DT><A name="PFS">Perfect forward secrecy (PFS)</A></DT> -<DD>A property of systems such as<A href="#DH"> Diffie-Hellman</A> key - exchange which use a long-term key (such as the shared secret in IKE) - and generate short-term keys as required. If an attacker who acquires - the long-term key<EM> provably</EM> can -<UL> -<LI><EM>neither</EM> read previous messages which he may have archived</LI> -<LI><EM>nor</EM> read future messages without performing additional - successful attacks</LI> -</UL> -<P>then the system has PFS. The attacker needs the short-term keys in - order to read the trafiic and merely having the long-term key does not - allow him to infer those. Of course, it may allow him to conduct - another attack (such as<A href="#middle"> man-in-the-middle</A>) which - gives him some short-term keys, but he does not automatically get them - just by acquiring the long-term key.</P> -<P>See also<A href="http://sandelman.ottawa.on.ca/ipsec/1996/08/msg00123.html"> - Phil Karn's definition</A>.</P> -</DD> -<DT>PFS</DT> -<DD>see Perfect Forward Secrecy</DD> -<DT><A name="PGP">PGP</A></DT> -<DD><B>P</B>retty<B> G</B>ood<B> P</B>rivacy, a personal encryption - system for email based on public key technology, written by Phil - Zimmerman. -<P>The 2.xx versions of PGP used the<A href="#RSA"> RSA</A> public key - algorithm and used<A href="#IDEA"> IDEA</A> as the symmetric cipher. - These versions are described in RFC 1991 and in<A href="#PGP"> - Garfinkel's book</A>. Since version 5, the products from<A href="#PGPI"> - PGP Inc</A>. have used<A href="#DH"> Diffie-Hellman</A> public key - methods and<A href="#CAST128"> CAST-128</A> symmetric encryption. These - can verify signatures from the 2.xx versions, but cannot exchange - encryted messages with them.</P> -<P>An<A href="mail.html#IETF"> IETF</A> working group has issued RFC - 2440 for an "Open PGP" standard, similar to the 5.x versions. PGP Inc. - staff were among the authors. A free<A href="#GPG"> Gnu Privacy Guard</A> - based on that standard is now available.</P> -<P>For more information on PGP, including how to obtain it, see our - cryptography<A href="web.html#tools"> links</A>.</P> -</DD> -<DT><A name="PGPI">PGP Inc.</A></DT> -<DD>A company founded by Zimmerman, the author of<A href="#PGP"> PGP</A> -, now a division of<A href="#NAI"> NAI</A>. See the<A href="http://www.pgp.com"> - corporate website</A>. Zimmerman left in 2001, and early in 2002 NAI - announced that they would no longer sell PGP.. -<P>Versions 6.5 and later of the PGP product include PGPnet, an IPsec - client for Macintosh or for Windows 95/98/NT. See our<A href="interop.html#pgpnet"> - interoperation documen</A>t.</P> -</DD> -<DT><A name="photuris">Photuris</A></DT> -<DD>Another key negotiation protocol, an alternative to<A href="#IKE"> - IKE</A>, described in RFCs 2522 and 2523.</DD> -<DT><A name="PPP">PPP</A></DT> -<DD><B>P</B>oint-to-<B>P</B>oint<B> P</B>rotocol, originally a method of - connecting over modems or serial lines, but see also PPPoE.</DD> -<DT><A name="PPPoE">PPPoE</A></DT> -<DD><B>PPP</B><B> o</B>ver<B> E</B>thernet, a somewhat odd protocol that - makes Ethernet look like a point-to-point serial link. It is widely - used for cable or ADSL Internet services, apparently mainly because it - lets the providers use access control and address assignmment - mechanisms developed for dialup networks.<A href="http://www.roaringpenguin.com"> - Roaring Penguin</A> provide a widely used Linux implementation.</DD> -<DT><A name="PPTP">PPTP</A></DT> -<DD><B>P</B>oint-to-<B>P</B>oint<B> T</B>unneling<B> P</B>rotocol, used - in some Microsoft VPN implementations. Papers discussing weaknesses in - it are on<A href="http://www.counterpane.com/publish.html"> - counterpane.com</A>. It is now largely obsolete, replaced by L2TP.</DD> -<DT><A name="PKI">PKI</A></DT> -<DD><B>P</B>ublic<B> K</B>ey<B> I</B>nfrastructure, the things an - organisation or community needs to set up in order to make<A href="#public"> - public key</A> cryptographic technology a standard part of their - operating procedures. -<P>There are several PKI products on the market. Typically they use a - hierarchy of<A href="#CA"> Certification Authorities (CAs)</A>. Often - they use<A href="#LDAP"> LDAP</A> access to<A href="#X509"> X.509</A> - directories to implement this.</P> -<P>See<A href="#web"> Web of Trust</A> for a different sort of - infrastructure.</P> -</DD> -<DT><A name="PKIX">PKIX</A></DT> -<DD><B>PKI</B> e<B>X</B>change, an<A href="mail.html#IETF"> IETF</A> - standard that allows<A href="#PKI"> PKI</A>s to talk to each other. -<P>This is required, for example, when users of a corporate PKI need to - communicate with people at client, supplier or government - organisations, any of which may have a different PKI in place. I should - be able to talk to you securely whenever:</P> -<UL> -<LI>your organisation and mine each have a PKI in place</LI> -<LI>you and I are each set up to use those PKIs</LI> -<LI>the two PKIs speak PKIX</LI> -<LI>the configuration allows the conversation</LI> -</UL> -<P>At time of writing (March 1999), this is not yet widely implemented - but is under quite active development by several groups.</P> -</DD> -<DT><A name="plaintext">Plaintext</A></DT> -<DD>The unencrypted input to a cipher, as opposed to the encrypted<A href="#ciphertext"> - ciphertext</A> output.</DD> -<DT><A name="Pluto">Pluto</A></DT> -<DD>The<A href="web.html#FreeSWAN"> Linux FreeS/WAN</A> daemon which - handles key exchange via the<A href="#IKE"> IKE</A> protocol, - connection negotiation, and other higher-level tasks. Pluto calls the<A href="#KLIPS"> - KLIPS</A> kernel code as required. For details, see the manual page - ipsec_pluto(8).</DD> -<DT><A name="public">Public Key Cryptography</A></DT> -<DD>In public key cryptography, keys are created in matched pairs. - Encrypt with one half of a pair and only the matching other half can - decrypt it. This contrasts with<A href="#symmetric"> symmetric or - secret key cryptography</A> in which a single key known to both parties - is used for both encryption and decryption. -<P>One half of each pair, called the public key, is made public. The - other half, called the private key, is kept secret. Messages can then - be sent by anyone who knows the public key to the holder of the private - key. Encrypt with the public key and you know that only someone with - the matching private key can decrypt.</P> -<P>Public key techniques can be used to create<A href="#signature"> - digital signatures</A> and to deal with key management issues, perhaps - the hardest part of effective deployment of<A href="#symmetric"> - symmetric ciphers</A>. The resulting<A href="#hybrid"> hybrid - cryptosystems</A> use public key methods to manage keys for symmetric - ciphers.</P> -<P>Many organisations are currently creating<A href="#PKI"> PKIs, public - key infrastructures</A> to make these benefits widely available.</P> -</DD> -<DT>Public Key Infrastructure</DT> -<DD>see<A href="#PKI"> PKI</A></DD> -<DT><A name="Q">Q</A></DT> -<DT><A name="R">R</A></DT> -<DT><A name="rainbow">Rainbow books</A></DT> -<DD>A set of US government standards for evaluation of "trusted computer - systems", of which the best known was the<A href="#orange"> Orange Book</A> -. One fairly often hears references to "C2 security" or a product - "evaluated at B1". The Rainbow books define the standards referred to - in those comments. -<P>See this<A href="http://www.fas.org/irp/nsa/rainbow.htm"> reference - page</A>.</P> -<P>The Rainbow books are now mainly obsolete, replaced by the - international<A href="#cc"> Common Criteria</A> standards.</P> -</DD> -<DT><A name="random">Random</A></DT> -<DD>A remarkably tricky term, far too much so for me to attempt a - definition here. Quite a few cryptosystems have been broken via attacks - on weak random number generators, even when the rest of the system was - sound. -<P>See<A href="http://nis.nsf.net/internet/documents/rfc/rfc1750.txt"> - RFC 1750</A> for the theory.</P> -<P>See the manual pages for<A href="manpage.d/ipsec_ranbits.8.html"> - ipsec_ranbits(8)</A> and ipsec_prng(3) for more on FreeS/WAN's use of - randomness. Both depend on the random(4) device driver..</P> -<P>A couple of years ago, there was extensive mailing list discussion - (archived<A href="http://www.openpgp.net/random/index.html"> here</A> -)of Linux /dev/random and FreeS/WAN. Since then, the design of the - random(4) driver has changed considerably. Linux 2.4 kernels have the - new driver..</P> -</DD> -<DT>Raptor</DT> -<DD>A firewall product for Windows NT offerring IPsec-based VPN - services. Linux FreeS/WAN interoperates with Raptor; see our<A href="interop.html#Raptor"> - interop</A> document for details. Raptor have recently merged with - Axent.</DD> -<DT><A name="RC4">RC4</A></DT> -<DD><B>R</B>ivest<B> C</B>ipher four, designed by Ron Rivest of<A href="#RSAco"> - RSA</A> and widely used. Believed highly secure with adequate key - length, but often implemented with inadequate key length to comply with - export restrictions.</DD> -<DT><A name="RC6">RC6</A></DT> -<DD><B>R</B>ivest<B> C</B>ipher six,<A href="#RSAco"> RSA</A>'s<A href="#AES"> - AES</A> candidate cipher.</DD> -<DT><A name="replay">Replay attack</A></DT> -<DD>An attack in which the attacker records data and later replays it in - an attempt to deceive the recipient.</DD> -<DT><A name="reverse">Reverse map</A></DT> -<DD>In<A href="ipsec.html#DNS"> DNS</A>, a table where IP addresses can - be used as the key for lookups which return a system name and/or other - information.</DD> -<DT>RFC</DT> -<DD><B>R</B>equest<B> F</B>or<B> C</B>omments, an Internet document. - Some RFCs are just informative. Others are standards. -<P>Our list of<A href="#IPSEC"> IPsec</A> and other security-related - RFCs is<A href="rfc.html#RFC"> here</A>, along with information on - methods of obtaining them.</P> -</DD> -<DT><A name="rijndael">Rijndael</A></DT> -<DD>a<A href="#block"> block cipher</A> designed by two Belgian - cryptographers, winner of the US government's<A href="#AES"> AES</A> - contest to pick a replacement for<A href="#DES"> DES</A>. See the<A href="http://www.esat.kuleuven.ac.be/~rijmen/rijndael"> - Rijndael home page</A>.</DD> -<DT><A name="RIPEMD">RIPEMD</A></DT> -<DD>A<A href="#digest"> message digest</A> algorithm. The current - version is RIPEMD-160 which gives a 160-bit hash.</DD> -<DT><A name="rootCA">Root CA</A></DT> -<DD>The top level<A href="#CA"> Certification Authority</A> in a - hierachy of such authorities.</DD> -<DT><A name="routable">Routable IP address</A></DT> -<DD>Most IP addresses can be used as "to" and "from" addresses in packet - headers. These are the routable addresses; we expect routing to be - possible for them. If we send a packet to one of them, we expect (in - most cases; there are various complications) that it will be delivered - if the address is in use and will cause an<A href="#ICMP.gloss"> ICMP</A> - error packet to come back to us if not. -<P>There are also several classes of<A href="#non-routable"> - non-routable</A> IP addresses.</P> -</DD> -<DT><A name="RSA">RSA algorithm</A></DT> -<DD><B>R</B>ivest<B> S</B>hamir<B> A</B>dleman<A href="#public"> public - key</A> algorithm, named for its three inventors. It is widely used and - likely to become moreso since it became free of patent encumbrances in - September 2000. -<P>RSA can be used to provide either<A href="#encryption"> encryption</A> - or<A href="#signature"> digital signatures</A>. In IPsec, it is used - only for signatures. These provide gateway-to-gateway<A href="#authentication"> - authentication</A> for<A href="#IKE"> IKE</A> negotiations.</P> -<P>For a full explanation of the algorithm, consult one of the standard - references such as<A href="biblio.html#schneier"> Applied Cryptography</A> -. A simple explanation is:</P> -<P>The great 17th century French mathematician<A href="http://www-groups.dcs.st-andrews.ac.uk/~history/Mathematicians/Fermat.html"> - Fermat</A> proved that,</P> -<P>for any prime p and number x, 0 <= x < p:</P> -<PRE> x^p == x modulo p - x^(p-1) == 1 modulo p, non-zero x - </PRE> -<P>From this it follows that if we have a pair of primes p, q and two - numbers e, d such that:</P> -<PRE> ed == 1 modulo lcm( p-1, q-1) - </PRE> - where lcm() is least common multiple, then -<BR> for all x, 0 <= x < pq: -<PRE> x^ed == x modulo pq - </PRE> -<P>So we construct such as set of numbers p, q, e, d and publish the - product N=pq and e as the public key. Using c for<A href="#ciphertext"> - ciphertext</A> and i for the input<A href="#plaintext"> plaintext</A>, - encryption is then:</P> -<PRE> c = i^e modulo N - </PRE> -<P>An attacker cannot deduce i from the cyphertext c, short of either - factoring N or solving the<A href="#dlog"> discrete logarithm</A> - problem for this field. If p, q are large primes (hundreds or thousands - of bits) no efficient solution to either problem is known.</P> -<P>The receiver, knowing the private key (N and d), can readily recover - the plaintext p since:</P> -<PRE> c^d == (i^e)^d modulo N - == i^ed modulo N - == i modulo N - </PRE> -<P>This gives an effective public key technique, with only a couple of - problems. It uses a good deal of computer time, since calculations with - large integers are not cheap, and there is no proof it is necessarily - secure since no-one has proven either factoring or discrete log cannot - be done efficiently. Quite a few good mathematicians have tried both - problems, and no-one has announced success, but there is no proof they - are insoluble.</P> -</DD> -<DT><A name="RSAco">RSA Data Security</A></DT> -<DD>A company founded by the inventors of the<A href="#RSA"> RSA</A> - public key algorithm.</DD> -<DT><A name="S">S</A></DT> -<DT><A name="SA">SA</A></DT> -<DD><B>S</B>ecurity<B> A</B>ssociation, the channel negotiated by the - higher levels of an<A href="#IPSEC"> IPsec</A> implementation (<A href="#IKE"> -IKE</A>) and used by the lower (<A href="#ESP">ESP</A> and<A href="#AH"> - AH</A>). SAs are unidirectional; you need a pair of them for two-way - communication. -<P>An SA is defined by three things -- the destination, the protocol (<A href="#AH"> -AH</A> or<A href="#ESP">ESP</A>) and the<A href="SPI"> SPI</A>, security - parameters index. It is used as an index to look up other things such - as session keys and intialisation vectors.</P> -<P>For more detail, see our section on<A href="ipsec.html"> IPsec</A> - and/or RFC 2401.</P> -</DD> -<DT><A name="SElinux">SE Linux</A></DT> -<DD><STRONG>S</STRONG>ecurity<STRONG> E</STRONG>nhanced Linux, an<A href="#NSA"> - NSA</A>-funded project to add<A href="#mandatory"> mandatory access - control</A> to Linux. See the<A href="http://www.nsa.gov/selinux"> - project home page</A>. -<P>According to their web pages, this work will include extending - mandatory access controls to IPsec tunnels.</P> -<P>Recent versions of SE Linux code use the<A href="#LSM"> Linux - Security Module</A> interface.</P> -</DD> -<DT><A name="SDNS">Secure DNS</A></DT> -<DD>A version of the<A href="ipsec.html#DNS"> DNS or Domain Name Service</A> - enhanced with authentication services. This is being designed by the<A href="mail.html#IETF"> - IETF</A> DNS security<A href="http://www.ietf.org/ids.by.wg/dnssec.html"> - working group</A>. Check the<A href="http://www.isc.org/bind.html"> - Internet Software Consortium</A> for information on implementation - progress and for the latest version of<A href="#BIND"> BIND</A>. - Another site has<A href="http://www.toad.com/~dnssec"> more information</A> -. -<P><A href="#IPSEC">IPsec</A> can use this plus<A href="#DH"> - Diffie-Hellman key exchange</A> to bootstrap itself. This allows<A href="#carpediem"> - opportunistic encryption</A>. Any pair of machines which can - authenticate each other via DNS can communicate securely, without - either a pre-existing shared secret or a shared<A href="#PKI"> PKI</A>.</P> -</DD> -<DT>Secret key cryptography</DT> -<DD>See<A href="#symmetric"> symmetric cryptography</A></DD> -<DT>Security Association</DT> -<DD>see<A href="#SA"> SA</A></DD> -<DT>Security Enhanced Linux</DT> -<DD>see<A href="#SElinux"> SE Linux</A></DD> -<DT><A name="sequence">Sequence number</A></DT> -<DD>A number added to a packet or message which indicates its position - in a sequence of packets or messages. This provides some security - against<A href="#replay"> replay attacks</A>. -<P>For<A href="ipsec.html#auto"> automatic keying</A> mode, the<A href="#IPSEC"> - IPsec</A> RFCs require that the sender generate sequence numbers for - each packet, but leave it optional whether the receiver does anything - with them.</P> -</DD> -<DT><A name="SHA">SHA</A></DT> -<DT>SHA-1</DT> -<DD><B>S</B>ecure<B> H</B>ash<B> A</B>lgorithm, a<A href="#digest"> - message digest algorithm</A> developed by the<A href="#NSA"> NSA</A> - for use in the Digital Signature standard,<A href="#FIPS"> FIPS</A> - number 186 from<A href="#NIST"> NIST</A>. SHA is an improved variant of<A -href="#MD4"> MD4</A> producing a 160-bit hash. -<P>SHA is one of two message digest algorithms available in IPsec. The - other is<A href="#MD5"> MD5</A>. Some people do not trust SHA because - it was developed by the<A href="#NSA"> NSA</A>. There is, as far as we - know, no cryptographic evidence that SHA is untrustworthy, but this - does not prevent that view from being strongly held.</P> -<P>The NSA made one small change after the release of the original SHA. - They did not give reasons. Iit may be a defense against some attack - they found and do not wish to disclose. Technically the modified - algorithm should be called SHA-1, but since it has replaced the - original algorithm in nearly all applications, it is generally just - referred to as SHA..</P> -</DD> -<DT><A name="SHA-256">SHA-256</A></DT> -<DT>SHA-384</DT> -<DT>SHA-512</DT> -<DD>Newer variants of SHA designed to match the strength of the 128, 192 - and 256-bit keys of<A href="#AES"> AES</A>. The work to break an - encryption algorithm's strength by<A href="#brute"> brute force</A> is - 2 -<!--math xmlns="http://www.w3.org/1998/Math/MathML"--> - -<!--msup--> - -<!--mi--> - keylength</(null)></(null)></(null)> operations but a<A href="birthday"> - birthday attack</A> on a hash needs only 2 -<!--math xmlns="http://www.w3.org/1998/Math/MathML"--> - -<!--msup--> - -<!--mrow--> - -<!--mi--> - hashlength</(null)> -<!--mo--> - /</(null)> -<!--mn--> - - 2</(null)></(null)></(null)></(null)> , so as a general rule you need a - hash twice the size of the key to get similar strength. SHA-256, - SHA-384 and SHA-512 are designed to match the 128, 192 and 256-bit key - sizes of AES, respectively.</DD> -<DT><A name="SIGINT">Signals intelligence (SIGINT)</A></DT> -<DD>Activities of government agencies from various nations aimed at - protecting their own communications and reading those of others. - Cryptography, cryptanalysis, wiretapping, interception and monitoring - of various sorts of signals. The players include the American<A href="#NSA"> - NSA</A>, British<A href="#GCHQ"> GCHQ</A> and Canadian<A href="#CSE"> - CSE</A>.</DD> -<DT><A name="SKIP">SKIP</A></DT> -<DD><B>S</B>imple<B> K</B>ey management for<B> I</B>nternet<B> P</B> -rotocols, an alternative to<A href="#IKE"> IKE</A> developed by Sun and - being marketed by their<A href="http://skip.incog.com"> Internet - Commerce Group</A>.</DD> -<DT><A name="snake">Snake oil</A></DT> -<DD>Bogus cryptography. See the<A href="http://www.interhack.net/people/cmcurtin/snake-oil-faq.html"> - Snake Oil FAQ</A> or<A href="http://www.counterpane.com/crypto-gram-9902.html#snakeoil"> - this paper</A> by Schneier.</DD> -<DT><A name="SPI">SPI</A></DT> -<DD><B>S</B>ecurity<B> P</B>arameter<B> I</B>ndex, an index used within<A -href="#IPSEC"> IPsec</A> to keep connections distinct. A<A href="#SA"> - Security Association (SA)</A> is defined by destination, protocol and - SPI. Without the SPI, two connections to the same gateway using the - same protocol could not be distinguished. -<P>For more detail, see our<A href="ipsec.html"> IPsec</A> section - and/or RFC 2401.</P> -</DD> -<DT><A name="SSH">SSH</A></DT> -<DD><B>S</B>ecure<B> SH</B>ell, an encrypting replacement for the - insecure Berkeley commands whose names begin with "r" for "remote": - rsh, rlogin, etc. -<P>For more information on SSH, including how to obtain it, see our - cryptography<A href="web.html#tools"> links</A>.</P> -</DD> -<DT><A name="SSHco">SSH Communications Security</A></DT> -<DD>A company founded by the authors of<A href="#SSH"> SSH</A>. Offices - are in<A href="http://www.ssh.fi"> Finland</A> and<A href="http://www.ipsec.com"> - California</A>. They have a toolkit for developers of IPsec - applications.</DD> -<DT><A name="SSL">SSL</A></DT> -<DD><A href="http://home.netscape.com/eng/ssl3">Secure Sockets Layer</A> -, a set of encryption and authentication services for web browsers, - developed by Netscape. Widely used in Internet commerce. Also known as<A -href="#TLS"> TLS</A>.</DD> -<DT>SSLeay</DT> -<DD>A free implementation of<A href="#SSL"> SSL</A> by Eric Young (eay) - and others. Developed in Australia; not subject to US export controls.</DD> -<DT><A name="static">static IP address</A></DT> -<DD>an IP adddress which is pre-set on the machine itself, as opposed to - a<A href="#dynamic"> dynamic address</A> which is assigned by a<A href="#DHCP"> - DHCP</A> server or obtained as part of the process of establishing a<A href="#PPP"> - PPP</A> or<A href="#PPPoE"> PPPoE</A> connection</DD> -<DT><A name="stream">Stream cipher</A></DT> -<DD>A<A href="#symmetric"> symmetric cipher</A> which produces a stream - of output which can be combined (often using XOR or bytewise addition) - with the plaintext to produce ciphertext. Contrasts with<A href="#block"> - block cipher</A>. -<P><A href="#IPSEC">IPsec</A> does not use stream ciphers. Their main - application is link-level encryption, for example of voice, video or - data streams on a wire or a radio signal.</P> -</DD> -<DT><A name="subnet">subnet</A></DT> -<DD>A group of IP addresses which are logically one network, typically - (but not always) assigned to a group of physically connected machines. - The range of addresses in a subnet is described using a subnet mask. - See next entry.</DD> -<DT>subnet mask</DT> -<DD>A method of indicating the addresses included in a subnet. Here are - two equivalent examples: -<UL> -<LI>101.101.101.0/24</LI> -<LI>101.101.101.0 with mask 255.255.255.0</LI> -</UL> -<P>The '24' is shorthand for a mask with the top 24 bits one and the - rest zero. This is exactly the same as 255.255.255.0 which has three - all-ones bytes and one all-zeros byte.</P> -<P>These indicate that, for this range of addresses, the top 24 bits are - to be treated as naming a network (often referred to as "the - 101.101.101.0/24 subnet") while most combinations of the low 8 bits can - be used to designate machines on that network. Two addresses are - reserved; 101.101.101.0 refers to the subnet rather than a specific - machine while 101.101.101.255 is a broadcast address. 1 to 254 are - available for machines.</P> -<P>It is common to find subnets arranged in a hierarchy. For example, a - large company might have a /16 subnet and allocate /24 subnets within - that to departments. An ISP might have a large subnet and allocate /26 - subnets (64 addresses, 62 usable) to business customers and /29 subnets - (8 addresses, 6 usable) to residential clients.</P> -</DD> -<DT><A name="SWAN">S/WAN</A></DT> -<DD>Secure Wide Area Network, a project involving<A href="#RSAco"> RSA - Data Security</A> and a number of other companies. The goal was to - ensure that all their<A href="#IPSEC"> IPsec</A> implementations would - interoperate so that their customers can communicate with each other - securely.</DD> -<DT><A name="symmetric">Symmetric cryptography</A></DT> -<DD>Symmetric cryptography, also referred to as conventional or secret - key cryptography, relies on a<EM> shared secret key</EM>, identical for - sender and receiver. Sender encrypts with that key, receiver decrypts - with it. The idea is that an eavesdropper without the key be unable to - read the messages. There are two main types of symmetric cipher,<A href="#block"> - block ciphers</A> and<A href="#stream"> stream ciphers</A>. -<P>Symmetric cryptography contrasts with<A href="#public"> public key</A> - or asymmetric systems where the two players use different keys.</P> -<P>The great difficulty in symmetric cryptography is, of course, key - management. Sender and receiver<EM> must</EM> have identical keys and - those keys<EM> must</EM> be kept secret from everyone else. Not too - much of a problem if only two people are involved and they can - conveniently meet privately or employ a trusted courier. Quite a - problem, though, in other circumstances.</P> -<P>It gets much worse if there are many people. An application might be - written to use only one key for communication among 100 people, for - example, but there would be serious problems. Do you actually trust all - of them that much? Do they trust each other that much? Should they? - What is at risk if that key is compromised? How are you going to - distribute that key to everyone without risking its secrecy? What do - you do when one of them leaves the company? Will you even know?</P> -<P>On the other hand, if you need unique keys for every possible - connection between a group of 100, then each user must have 99 keys. - You need either 99*100/2 = 4950<EM> secure</EM> key exchanges between - users or a central authority that<EM> securely</EM> distributes 100 key - packets, each with a different set of 99 keys.</P> -<P>Either of these is possible, though tricky, for 100 users. Either - becomes an administrative nightmare for larger numbers. Moreover, keys<EM> - must</EM> be changed regularly, so the problem of key distribution - comes up again and again. If you use the same key for many messages - then an attacker has more text to work with in an attempt to crack that - key. Moreover, one successful crack will give him or her the text of - all those messages.</P> -<P>In short, the<EM> hardest part of conventional cryptography is key - management</EM>. Today the standard solution is to build a<A href="#hybrid"> - hybrid system</A> using<A href="#public"> public key</A> techniques to - manage keys.</P> -</DD> -<DT><A name="T">T</A></DT> -<DT><A name="TIS">TIS</A></DT> -<DD>Trusted Information Systems, a firewall vendor now part of<A href="#NAI"> - NAI</A>. Their Gauntlet product offers IPsec VPN services. TIS - implemented the first version of<A href="#SDNS"> Secure DNS</A> on a<A href="#DARPA"> - DARPA</A> contract.</DD> -<DT><A name="TLS">TLS</A></DT> -<DD><B>T</B>ransport<B> L</B>ayer<B> S</B>ecurity, a newer name for<A href="#SSL"> - SSL</A>.</DD> -<DT><A name="TOS">TOS field</A></DT> -<DD>The<STRONG> T</STRONG>ype<STRONG> O</STRONG>f<STRONG> S</STRONG> -ervice field in an IP header, used to control qualkity of service - routing.</DD> -<DT><A name="traffic">Traffic analysis</A></DT> -<DD>Deducing useful intelligence from patterns of message traffic, - without breaking codes or reading the messages. In one case during - World War II, the British guessed an attack was coming because all - German radio traffic stopped. The "radio silence" order, intended to - preserve security, actually gave the game away. -<P>In an industrial espionage situation, one might deduce something - interesting just by knowing that company A and company B were talking, - especially if one were able to tell which departments were involved, or - if one already knew that A was looking for acquisitions and B was - seeking funds for expansion.</P> -<P>In general, traffic analysis by itself is not very useful. However, - in the context of a larger intelligence effort where quite a bit is - already known, it can be very useful. When you are solving a complex - puzzle, every little bit helps.</P> -<P><A href="#IPSEC">IPsec</A> itself does not defend against traffic - analysis, but carefully thought out systems using IPsec can provide at - least partial protection. In particular, one might want to encrypt more - traffic than was strictly necessary, route things in odd ways, or even - encrypt dummy packets, to confuse the analyst. We discuss this<A href="ipsec.html#traffic.resist"> - here</A>.</P> -</DD> -<DT><A name="transport">Transport mode</A></DT> -<DD>An IPsec application in which the IPsec gateway is the destination - of the protected packets, a machine acts as its own gateway. Contrast - with<A href="#tunnel"> tunnel mode</A>.</DD> -<DT>Triple DES</DT> -<DD>see<A href="#3DES"> 3DES</A></DD> -<DT><A name="TTL">TTL</A></DT> -<DD><STRONG>T</STRONG>ime<STRONG> T</STRONG>o<STRONG> L</STRONG>ive, - used to control<A href="ipsec.html#DNS"> DNS</A> caching. Servers - discard cached records whose TTL expires</DD> -<DT><A name="tunnel">Tunnel mode</A></DT> -<DD>An IPsec application in which an IPsec gateway provides protection - for packets to and from other systems. Contrast with<A href="#transport"> - transport mode</A>.</DD> -<DT><A name="2key">Two-key Triple DES</A></DT> -<DD>A variant of<A href="#3DES"> triple DES or 3DES</A> in which only - two keys are used. As in the three-key version, the order of operations - is<A href="#EDE"> EDE</A> or encrypt-decrypt-encrypt, but in the - two-key variant the first and third keys are the same. -<P>3DES with three keys has 3*56 = 168 bits of key but has only 112-bit - strength against a<A href="#meet"> meet-in-the-middle</A> attack, so it - is possible that the two key version is just as strong. Last I looked, - this was an open question in the research literature.</P> -<P>RFC 2451 defines triple DES for<A href="#IPSEC"> IPsec</A> as the - three-key variant. The two-key variant should not be used and is not - implemented directly in<A href="web.html#FreeSWAN"> Linux FreeS/WAN</A> -. It cannot be used in automatically keyed mode without major fiddles in - the source code. For manually keyed connections, you could make Linux - FreeS/WAN talk to a two-key implementation by setting two keys the same - in /etc/ipsec.conf.</P> -</DD> -<DT><A name="U">U</A></DT> -<DT><A name="V">V</A></DT> -<DT><A name="virtual">Virtual Interface</A></DT> -<DD>A<A href="#Linux"> Linux</A> feature which allows one physical - network interface to have two or more IP addresses. See the<CITE> Linux - Network Administrator's Guide</CITE> in<A href="biblio.html#kirch"> - book form</A> or<A href="http://metalab.unc.edu/LDP/LDP/nag/node1.html"> - on the web</A> for details.</DD> -<DT>Virtual Private Network</DT> -<DD>see<A href="#VPN"> VPN</A></DD> -<DT><A name="VPN">VPN</A></DT> -<DD><B>V</B>irtual<B> P</B>rivate<B> N</B>etwork, a network which can - safely be used as if it were private, even though some of its - communication uses insecure connections. All traffic on those - connections is encrypted. -<P><A href="#IPSEC">IPsec</A> is not the only technique available for - building VPNs, but it is the only method defined by<A href="rfc.html#RFC"> - RFCs</A> and supported by many vendors. VPNs are by no means the only - thing you can do with IPsec, but they may be the most important - application for many users.</P> -</DD> -<DT><A name="VPNC">VPNC</A></DT> -<DD><A href="http://www.vpnc.org">Virtual Private Network Consortium</A> -, an association of vendors of VPN products.</DD> -<DT><A name="W">W</A></DT> -<DT><A name="Wassenaar.gloss">Wassenaar Arrangement</A></DT> -<DD>An international agreement restricting export of munitions and other - tools of war. Unfortunately, cryptographic software is also restricted - under the current version of the agreement.<A href="politics.html#Wassenaar"> - Discussion</A>.</DD> -<DT><A name="web">Web of Trust</A></DT> -<DD><A href="#PGP">PGP</A>'s method of certifying keys. Any user can - sign a key; you decide which signatures or combinations of signatures - to accept as certification. This contrasts with the hierarchy of<A href="#CA"> - CAs (Certification Authorities)</A> used in many<A href="#PKI"> PKIs - (Public Key Infrastructures)</A>. -<P>See<A href="#GTR"> Global Trust Register</A> for an interesting - addition to the web of trust.</P> -</DD> -<DT><A name="WEP">WEP (Wired Equivalent Privacy)</A></DT> -<DD>The cryptographic part of the<A href="#IEEE"> IEEE</A> standard for - wireless LANs. As the name suggests, this is designed to be only as - secure as a normal wired ethernet. Anyone with a network conection can - tap it. Its advocates would claim this is good design, refusing to - build in complex features beyond the actual requirements. -<P>Critics refer to WEP as "Wire<EM>tap</EM> Equivalent Privacy", and - consider it a horribly flawed design based on bogus "requirements". You - do not control radio waves as you might control your wires, so the - metaphor in the rationale is utterly inapplicable. A security policy - that chooses not to invest resources in protecting against certain - attacks which can only be conducted by people physically plugged into - your LAN may or may not be reasonable. The same policy is completely - unreasonable when someone can "plug in" from a laptop half a block - away..</P> -<P>There has been considerable analysis indicating that WEP is seriously - flawed. A FAQ on attacks against WEP is available. Part of it reads:</P> -<BLOCKQUOTE> ... attacks are practical to mount using only inexpensive - off-the-shelf equipment. We recommend that anyone using an 802.11 - wireless network not rely on WEP for security, and employ other - security measures to protect their wireless network. Note that our - attacks apply to both 40-bit and the so-called 128-bit versions of WEP - equally well.</BLOCKQUOTE> -<P>WEP appears to be yet another instance of governments, and - unfortunately some vendors and standards bodies, deliberately promoting - hopelessly flawed "security" products, apparently mainly for the - benefit of eavesdropping agencies. See this<A href="politics.html#weak"> - discussion</A>.</P> -</DD> -<DT><A name="X">X</A></DT> -<DT><A name="X509">X.509</A></DT> -<DD>A standard from the<A href="http://www.itu.int"> ITU (International - Telecommunication Union)</A>, for hierarchical directories with - authentication services, used in many<A href="#PKI"> PKI</A> - implementations. -<P>Use of X.509 services, via the<A href="#LDAP"> LDAP protocol</A>, for - certification of keys is allowed but not required by the<A href="#IPSEC"> - IPsec</A> RFCs. It is not yet implemented in<A href="web.html#FreeSWAN"> - Linux FreeS/WAN</A>.</P> -</DD> -<DT>Xedia</DT> -<DD>A vendor of router and Internet access products, now part of Lucent. - Their QVPN products interoperate with Linux FreeS/WAN; see our<A href="interop.html#Xedia"> - interop document</A>.</DD> -<DT><A name="Y">Y</A></DT> -<DT><A name="Z">Z</A></DT> -</DL> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="web.html">Previous</A> -<A HREF="biblio.html">Next</A> -</BODY> -</HTML> diff --git a/doc/index.html b/doc/index.html deleted file mode 100644 index 427ed7ea7..000000000 --- a/doc/index.html +++ /dev/null @@ -1,55 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>FreeS/WAN index</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, encryption, cryptography, FreeS/WAN, FreeSWAN"> - <!-- - - Written by Claudia Schmeing for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: index.html,v 1.1 2004/03/15 20:35:21 as Exp $ - Last changed: $Date: 2004/03/15 20:35:21 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1>FreeS/WAN documentation</h1> - -<ul> - <li><a href="intro.html">Introduction</a></li> - <li><a href="upgrading.html">Upgrading to 2.x</a></li> -</ul> - -<ul> - <li><a href="quickstart.html">Quickstart guide to Opportunistic Encryption</a></li> - <li><a href="install.html">Installing</a></li> - <li><a href="config.html">Configuring</a></li> - <li><a href="policygroups.html">Policy Groups</a> - </li> - <li><a href="interop.html">Interoperating</a> -<FONT COLOR="#FF0000">New and improved!</FONT></li> - <li><a href="faq.html">FAQ</a></li> - <li><a href="trouble.html">Troubleshooting and problem reporting</a></li> -</ul> - -<ul> - <li><a href="toc.html">Full table of contents, with much more</a></li> - <li><a href="HowTo.html">All our docs as one big file</a></li> -</ul> - -<p>For technical support and other questions, use our <a -href="mail.html">mailing lists</a>.</p> - -<pre> This index last changed: $Date: 2004/03/15 20:35:21 $</pre> - -</body> -</html> diff --git a/doc/install.html b/doc/install.html deleted file mode 100644 index 6cd55535e..000000000 --- a/doc/install.html +++ /dev/null @@ -1,286 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="adv_config.html">Previous</A> -<A HREF="config.html">Next</A> -<HR> -<H1><A name="install">Installing FreeS/WAN</A></H1> -<P>This document will teach you how to install Linux FreeS/WAN. If your - distribution comes with Linux FreeS/WAN, we offer tips to get you - started.</P> -<H2><A NAME="15_1">Requirements</A></H2> -<P>To install FreeS/WAN you must:</P> -<UL> -<LI>be running Linux with the 2.4 or 2.2 kernel series. See this<A HREF="http://www.freeswan.ca/download.php#contact"> - kernel compatibility table</A>. -<BR>We also have experimental support for 2.6 kernels. Here are two - basic approaches: -<UL> -<LI> install FreeS/WAN, including its<A HREF="ipsec.html#parts"> KLIPS</A> - kernel code. This will remove the native IPsec stack and replace it - with KLIPS.</LI> -<LI> install the FreeS/WAN<A HREF="ipsec.html#parts"> userland tools</A> - (keying daemon and supporting scripts) for use with<A HREF="http://lartc.org/howto/lartc.ipsec.html"> - 2.6 kernel native IPsec</A>,</LI> -</UL> - See also these<A HREF="2.6.known-issues"> known issues with 2.6</A>.</LI> -<LI>have root access to your Linux box</LI> -<LI>choose the version of FreeS/WAN you wish to install based on<A HREF="http://www.freeswan.org/mail.html"> - mailing list reports</A> -<!-- or -our updates page (coming soon)--> -</LI> -</UL> -<H2><A NAME="15_2">Choose your install method</A></H2> -<P>There are three basic ways to get FreeS/WAN onto your system:</P> -<UL> -<LI>activating and testing a FreeS/WAN that<A HREF="#distroinstall"> - shipped with your Linux distribution</A></LI> -<LI><A HREF="#rpminstall">RPM install</A></LI> -<LI><A HREF="#srcinstall">Install from source</A></LI> -</UL> -<A NAME="distroinstall"></A> -<H2><A NAME="15_3">FreeS/WAN ships with some Linuxes</A></H2> -<P>FreeS/WAN comes with<A HREF="intro.html#distwith"> these - distributions</A>.</P> -<P>If you're running one of these, include FreeS/WAN in the choices you - make during installation, or add it later using the distribution's - tools.</P> -<H3><A NAME="15_3_1">FreeS/WAN may be altered...</A></H3> -<P>Your distribution may have integrated extra features, such as Andreas - Steffen's X.509 patch, into FreeS/WAN. It may also use custom startup - script locations or directory names.</P> -<H3><A NAME="15_3_2">You might need to create an authentication keypair</A> -</H3> -<P>If your FreeS/WAN came with your distribution, you may wish to - generate a fresh RSA key pair. FreeS/WAN will use these keys for - authentication.</P> -<P> To do this, become root, and type:</P> -<PRE> ipsec newhostkey --output /etc/ipsec.secrets --hostname xy.example.com - chmod 600 /etc/ipsec.secrets</PRE> -<P>where you replace xy.example.com with your machine's fully-qualified - domain name. Generate some randomness, for example by wiggling your - mouse, to speed the process.</P> -<P>The resulting ipsec.secrets looks like:</P> -<PRE>: RSA { - # RSA 2192 bits xy.example.com Sun Jun 8 13:42:19 2003 - # for signatures only, UNSAFE FOR ENCRYPTION - #pubkey=0sAQOFppfeE3cC7wqJi... - Modulus: 0x85a697de137702ef0... - # everything after this point is secret - PrivateExponent: 0x16466ea5033e807... - Prime1: 0xdfb5003c8947b7cc88759065... - Prime2: 0x98f199b9149fde11ec956c814... - Exponent1: 0x9523557db0da7a885af90aee... - Exponent2: 0x65f6667b63153eb69db8f300dbb... - Coefficient: 0x90ad00415d3ca17bebff123413fc518... - } -# do not change the indenting of that "}"</PRE> -<P>In the actual file, the strings are much longer.</P> -<H3><A NAME="15_3_3">Start and test FreeS/WAN</A></H3> -<P>You can now<A HREF="install.html#starttest"> start FreeS/WAN and test - whether it's been successfully installed.</A>.</P> -<A NAME="rpminstall"></A> -<H2><A NAME="15_4">RPM install</A></H2> -<P>These instructions are for a recent Red Hat with a stock Red Hat - kernel. We know that Mandrake and SUSE also produce FreeS/WAN RPMs. If - you're running either, install using your distribution's tools.</P> -<H3><A NAME="15_4_1">Download RPMs</A></H3> -<P>Decide which functionality you need:</P> -<UL> -<LI>standard FreeS/WAN RPMs. Use these shortcuts: -<BR> -<UL> -<LI>(for 2.6 kernels: userland only) -<BR> ncftpget - ftp://ftp.xs4all.nl/pub/crypto/freeswan/binaries/RedHat-RPMs/\*userland* -</LI> -<LI>(for 2.4 kernels) -<BR> ncftpget - ftp://ftp.xs4all.nl/pub/crypto/freeswan/binaries/RedHat-RPMs/`uname -r - | tr -d 'a-wy-z'`/\*</LI> -<LI> or view all the offerings at our<A href="ftp://ftp.xs4all.nl/pub/crypto/freeswan/binaries/RedHat-RPMs"> - FTP site</A>.</LI> -</UL> -</LI> -<LI>unofficial<A href="http://www.freeswan.ca/download.php"> Super - FreeS/WAN</A> RPMs, which include Andreas Steffen's X.509 patch and - more. Super FreeS/WAN RPMs do not currently include<A HREF="glossary.html#NAT.gloss"> - Network Address Translation</A> (NAT) traversal, but Super FreeS/WAN - source does.</LI> -</UL> -<A NAME="2.6.rpm"></A> -<P>For 2.6 kernels, get the latest FreeS/WAN userland RPM, for example:</P> -<PRE> freeswan-userland-2.04.9-0.i386.rpm</PRE> -<P>Note: FreeS/WAN's support for 2.6 kernel IPsec is preliminary. Please - see<A HREf="2.6.known-issues"> 2.6.known-issues</A>, and the latest<A HREF="http://www.freeswan.org/mail.html"> - mailing list reports</A>.</P> -<P>Change to your new FreeS/WAN directory, and make and install the</P> -<P>For 2.4 kernels, get both kernel and userland RPMs. Check your kernel - version with</P> -<PRE> uname -r</PRE> -<P>Get a kernel module which matches that version. For example:</P> -<PRE> freeswan-module-2.04_2.4.20_20.9-0.i386.rpm</PRE> -<P>Note: These modules<B> will only work on the Red Hat kernel they were - built for</B>, since they are very sensitive to small changes in the - kernel.</P> -<P>Get FreeS/WAN utilities to match. For example:</P> -<PRE> freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm</PRE> -<H3><A NAME="15_4_2">For freeswan.org RPMs: check signatures</A></H3> -<P>While you're at our ftp site, grab the RPM signing key</P> -<PRE> freeswan-rpmsign.asc</PRE> -<P>If you're running RedHat 8.x or later, import this key into the RPM - database:</P> -<PRE> rpm --import freeswan-rpmsign.asc</PRE> -<P>For RedHat 7.x systems, you'll need to add it to your<A HREF="glossary.html#PGP"> - PGP</A> keyring:</P> -<PRE> pgp -ka freeswan-rpmsign.asc</PRE> -<P>Check the digital signatures on both RPMs using:</P> -<PRE> rpm --checksig freeswan*.rpm </PRE> -<P>You should see that these signatures are good:</P> -<PRE> freeswan-module-2.04_2.4.20_20.9-0.i386.rpm: pgp md5 OK - freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm: pgp md5 OK</PRE> -<H3><A NAME="15_4_3">Install the RPMs</A></H3> -<P>Become root:</P> -<PRE> su</PRE> -<P>For a first time install, use:</P> -<PRE> rpm -ivh freeswan*.rpm</PRE> -<P>To upgrade existing RPMs (and keep all .conf files in place), use:</P> -<PRE> rpm -Uvh freeswan*.rpm</PRE> -<P>If you're upgrading from FreeS/WAN 1.x to 2.x RPMs, and encounter - problems, see<A HREF="upgrading.html#upgrading.rpms"> this note</A>.</P> -<H3><A NAME="15_4_4">Start and Test FreeS/WAN</A></H3> -<P>Now,<A HREF="install.html#starttest"> start FreeS/WAN and test your - install</A>.</P> -<A NAME="srcinstall"></A> -<H2><A NAME="15_5">Install from Source</A></H2> - -<!-- Most of this section, along with "Start and Test", can replace -INSTALL. --> -<H3><A NAME="15_5_1">Decide what functionality you need</A></H3> -<P>Your choices are:</P> -<UL> -<LI><A HREF="ftp://ftp.xs4all.nl/pub/crypto/freeswan">standard FreeS/WAN</A> -,</LI> -<LI>standard FreeS/WAN plus any of these<A HREF="web.html#patch"> - user-supported patches</A>, or</LI> -<LI><A HREF="http://www.freeswan.ca/download">Super FreeS/WAN</A>, an - unofficial FreeS/WAN pre-patched with many of the above. Provides - additional algorithms, X.509, SA deletion, dead peer detection, and<A HREF="glossary.html#NAT.gloss"> - Network Address Translation</A> (NAT) traversal.</LI> -</UL> -<H3><A NAME="15_5_2">Download FreeS/WAN</A></H3> -<P>Download the source tarball you've chosen, along with any patches.</P> -<H3><A NAME="15_5_3">For freeswan.org source: check its signature</A></H3> -<P>While you're at our ftp site, get our source signing key</P> -<PRE> freeswan-sigkey.asc</PRE> -<P>Add it to your PGP keyring:</P> -<PRE> pgp -ka freeswan-sigkey.asc</PRE> -<P>Check the signature using:</P> -<PRE> pgp freeswan-2.04.tar.gz.sig freeswan-2.04.tar.gz</PRE> -<P>You should see something like:</P> -<PRE> Good signature from user "Linux FreeS/WAN Software Team (build@freeswan.org)". - Signature made 2002/06/26 21:04 GMT using 2047-bit key, key ID 46EAFCE1</PRE> - -<!-- Note to self: build@freeswan.org has angled brackets in the original. - Changed because it conflicts with HTML tags. --> -<H3><A NAME="15_5_4">Untar, unzip</A></H3> -<P>As root, unpack your FreeS/WAN source into<VAR> /usr/src</VAR>.</P> -<PRE> su - mv freeswan-2.04.tar.gz /usr/src - cd /usr/src - tar -xzf freeswan-2.04.tar.gz -</PRE> -<H3><A NAME="15_5_5">Patch if desired</A></H3> -<P>Now's the time to add any patches. The contributor may have special - instructions, or you may simply use the patch command.</P> -<H3><A NAME="15_5_6">... and Make</A></H3> -<P>Choose one of the methods below.</P> -<H4>Userland-only Install for 2.6 kernels</H4> -<A NAME="2.6.src"></A> -<P>Note: FreeS/WAN's support for 2.6 kernel IPsec is preliminary. Please - see<A HREf="2.6.known-issues"> 2.6.known-issues</A>, and the latest<A HREF="http://www.freeswan.org/mail.html"> - mailing list reports</A>.</P> -<P>Change to your new FreeS/WAN directory, and make and install the - FreeS/WAN userland tools.</P> -<PRE> cd /usr/src/freeswan-2.04 - make programs - make install</PRE> -<P>Now,<A HREF="install.html#starttest"> start FreeS/WAN and test your - install</A>.</P> -<H4>KLIPS install for 2.2, 2.4, or 2.6 kernels</H4> -<A NAME="modinstall"></A> -<P>To make a modular version of KLIPS, along with other FreeS/WAN - programs you'll need, use the command sequence below. This will change - to your new FreeS/WAN directory, make the FreeS/WAN module (and other - stuff), and install it all.</P> -<PRE> cd /usr/src/freeswan-2.04 - make oldmod - make minstall</PRE> -<P><A HREF="install.html#starttest">Start FreeS/WAN and test your - install</A>.</P> -<P>To link KLIPS statically into your kernel (using your old kernel - settings), and install other FreeS/WAN components, do:</P> -<PRE> cd /usr/src/freeswan-2.04 - make oldmod - make minstall</PRE> -<P>Reboot your system and<A HREF="install.html#testonly"> test your - install</A>.</P> -<P>For other ways to compile KLIPS, see our Makefile.</P> -<A name="starttest"></A> -<H2><A NAME="15_6">Start FreeS/WAN and test your install</A></H2> -<P>Bring FreeS/WAN up with:</P> -<PRE> service ipsec start</PRE> -<P>This is not necessary if you've rebooted.</P> -<A name="testonly"></A> -<H2><A NAME="15_7">Test your install</A></H2> -<P>To check that you have a successful install, run:</P> -<PRE> ipsec verify</PRE> -<P>You should see at least:</P> -<PRE> - Checking your system to see if IPsec got installed and started correctly - Version check and ipsec on-path [OK] - Checking for KLIPS support in kernel [OK] - Checking for RSA private key (/etc/ipsec.secrets) [OK] - Checking that pluto is running [OK] -</PRE> -<P>If any of these first four checks fails, see our<A href="trouble.html#install.check"> - troubleshooting guide</A>.</P> -<H2><A NAME="15_8">Making FreeS/WAN play well with others</A></H2> -<P>There are at least a couple of things on your system that might - interfere with FreeS/WAN, and now's a good time to check these:</P> -<UL> -<LI>Firewalling. You need to allow UDP 500 through your firewall, plus - ESP (protocol 50) and AH (protocol 51). For more information, see our - updated firewalls document (coming soon).</LI> -<LI>Network address translation. Do not NAT the packets you will be - tunneling.</LI> -</UL> -<H2><A NAME="15_9">Configure for your needs</A></H2> -<P>You'll need to configure FreeS/WAN for your local site. Have a look - at our<A HREF="quickstart.html"> opportunism quickstart guide</A> to - see if that easy method is right for your needs. Or, see how to<A HREF="config.html"> - configure a network-to-network or Road Warrior style VPN</A>.</P> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="adv_config.html">Previous</A> -<A HREF="config.html">Next</A> -</BODY> -</HTML> diff --git a/doc/interop.html b/doc/interop.html deleted file mode 100644 index 1cd7b9e78..000000000 --- a/doc/interop.html +++ /dev/null @@ -1,983 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="compat.html">Previous</A> -<A HREF="performance.html">Next</A> -<HR> -<A NAME="interop"></A> -<H1><A NAME="10">Interoperating with FreeS/WAN</A></H1> -<P>The FreeS/WAN project needs you! We rely on the user community to - keep up to date. Mail users@lists.freeswan.org with your interop - success stories.</P> -<P><STRONG>Please note</STRONG>: Most of our interop examples feature - Linux FreeS/WAN 1.x config files. You can convert them to 2.x files - fairly easily with the patch in our<A HREF="upgrading.html#ipsec.conf_v2"> - Upgrading Guide</A>.</P> -<H2><A NAME="10_1">Interop at a Glance</A></H2> -<TABLE BORDER="1"> -<TR><TD> </TD><TD colspan="5">FreeS/WAN VPN</TD><TD>Road Warrior</TD><TD> -OE</TD></TR> -<TR><TD> </TD><TD>PSK</TD><TD>RSA Secret</TD><TD>X.509 -<BR><SMALL><A HREF="#interoprules">(requires patch)</A></SMALL></TD><TD> -NAT-Traversal -<BR><SMALL><A HREF="#interoprules">(requires patch)</A></SMALL></TD><TD> -Manual -<BR>Keying</TD><TD> </TD><TD> </TD></TR> -<TR><TD colspan="8">More Compatible</TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="web.html#freeswan">FreeS/WAN</A><A NAME="freeswan.top"> - </A></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD><FONT color="#00cc00">Yes</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#isakmpd">isakmpd (OpenBSD)</A><A NAME="isakmpd.top"> </A> -</TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> -<FONT color="#cc0000">No </FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#kame">Kame (FreeBSD, -<BR> NetBSD, MacOSX) -<BR> <SMALL>aka racoon</SMALL></A><A NAME="kame.top"> </A></TD><TD><FONT -color="#00cc00">Yes</FONT></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> -<FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#mcafee">McAfee VPN -<BR><SMALL>was PGPNet</SMALL></A><A NAME="mcafee.top"> </A></TD><TD><FONT -color="#00cc00">Yes</FONT></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> -<FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#microsoft">Microsoft -<BR> Windows 2000/XP</A><A NAME="microsoft.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> - </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#cc0000"> -No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="glossary.html#ssh">SSH Sentinel</A><A NAME="ssh.top"> </A> -</TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD><FONT color="#cccc00">Maybe</FONT></TD><TD> </TD><TD><FONT -color="#00cc00">Yes</FONT></TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#safenet">Safenet SoftPK -<BR>/SoftRemote</A><A NAME="safenet.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> - </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#cc0000"> -No</FONT></TD></TR> -<TR><TD colspan="8">Other</TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#6wind">6Wind</A><A NAME="6wind.top"> </A></TD><TD> </TD><TD> - </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> -<FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#alcatel">Alcatel Timestep</A><A NAME="alcatel.top"> </A> -</TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> - </TD><TD> </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#apple">Apple Macintosh -<BR>System 10+</A><A NAME="apple.top"> </A></TD><TD><FONT color="#cccc00"> -Maybe</FONT></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#cccc00"> -Maybe</FONT></TD><TD> </TD><TD><FONT color="#cccc00">Maybe</FONT></TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#ashleylaurent">AshleyLaurent -<BR> VPCom</A><A NAME="ashleylaurent.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT -color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#borderware">Borderware</A><A NAME="borderware.top"> </A> -</TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD><TD><FONT color="#cc0000"> -No</FONT></TD></TR> - -<!-- -http://www.cequrux.com/vpn-guides.php3 -"coming soon" guide to connect with FreeS/WAN. ---> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#checkpoint">Check Point FW-1/VPN-1</A><A NAME="checkpoint.top"> - </A></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> -<FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#cisco">Cisco with 3DES</A><A NAME="cisco.top"> </A></TD><TD> -<FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#cccc00">Maybe</FONT> -</TD><TD> </TD><TD><FONT color="#cccc00">Maybe</FONT></TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#equinux">Equinux VPN Tracker -<BR> (for Mac OS X)</A><A NAME="equinux.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD><FONT color="#cccc00">Maybe</FONT></TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#fsecure">F-Secure</A><A NAME="fsecure.top"> </A></TD><TD> -<FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD><FONT color="#cccc00"> -Maybe</FONT></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#gauntlet">Gauntlet GVPN</A><A NAME="gauntlet.top"> </A> -</TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT color="#cc0000"> -No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#aix">IBM AIX</A><A NAME="aix.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD><FONT color="#cccc00">Maybe</FONT></TD><TD> - </TD><TD> </TD><TD> </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#as400">IBM AS/400</A><A NAME="as400"> </A></TD><TD><FONT -color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#intel">Intel Shiva -<BR>LANRover/Net Structure</A><A NAME="intel.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT -color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#lancom">LanCom (formerly ELSA)</A><A NAME="lancom.top"> - </A></TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> - </TD><TD> </TD><TD> </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#linksys">Linksys</A><A NAME="linksys.top"> </A></TD><TD> -<FONT color="#cccc00">Maybe</FONT></TD><TD> </TD><TD><FONT color="#cc0000"> -No</FONT></TD><TD> </TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> -<FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#lucent">Lucent</A><A NAME="lucent.top"> </A></TD><TD><FONT -color="#cccc00">Partial</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#netasq">Netasq</A><A NAME="netasq.top"> </A></TD><TD> - </TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#netcelo">netcelo</A><A NAME="netcelo.top"> </A></TD><TD> - </TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#netgear">Netgear fvs318</A><A NAME="netgear.top"> </A> -</TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> - </TD><TD> </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#netscreen">Netscreen 100 -<BR>or 5xp</A><A NAME="netscreen.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT color="#cccc00"> -Maybe</FONT></TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#nortel">Nortel Contivity</A><A NAME="nortel.top"> </A> -</TD><TD><FONT color="#cccc00">Partial</FONT></TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD><FONT color="#cccc00">Maybe</FONT></TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#radguard">RadGuard</A><A NAME="radguard.top"> </A></TD><TD> -<FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#raptor">Raptor</A><A NAME="raptor"> </A></TD><TD><FONT -color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#redcreek">Redcreek Ravlin</A><A NAME="redcreek.top"> </A> -</TD><TD><FONT color="#00cc00">Yes</FONT><FONT color="#cccc00">/Partial</FONT> -</TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT color="#cc0000"> -No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#sonicwall">SonicWall</A><A NAME="sonicwall.top"> </A></TD><TD> -<FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT -color="#cccc00">Maybe</FONT></TD><TD><FONT color="#cc0000">No</FONT></TD><TD> -<FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#sun">Sun Solaris</A><A NAME="sun.top"> </A></TD><TD><FONT -color="#00cc00">Yes</FONT></TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT> -</TD><TD> </TD><TD><FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD><FONT -color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#symantec">Symantec</A><A NAME="symantec.top"> </A></TD><TD> -<FONT color="#00cc00">Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> - </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#watchguard">Watchguard -<BR> Firebox</A><A NAME="watchguard.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD><FONT color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#xedia">Xedia Access Point -<BR>/QVPN</A><A NAME="xedia.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT -color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR><TD><A HREF="#zyxel">Zyxel Zywall -<BR>/Prestige</A><A NAME="zyxel.top"> </A></TD><TD><FONT color="#00cc00"> -Yes</FONT></TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD> </TD><TD><FONT -color="#cc0000">No</FONT></TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE - - -<TR> -<TD><A HREF="#sample">sample</A></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - ---> -<TR><TD> </TD><TD>PSK</TD><TD>RSA Secret</TD><TD>X.509 -<BR><SMALL><A HREF="#interoprules">(requires patch)</A></SMALL></TD><TD> -NAT-Traversal -<BR><SMALL><A HREF="#interoprules">(requires patch)</A></SMALL></TD><TD> -Manual -<BR>Keying</TD><TD> </TD><TD> </TD></TR> -<TR><TD> </TD><TD colspan="5">FreeS/WAN VPN</TD><TD>Road Warrior</TD><TD> -OE</TD></TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -</TABLE> -<H3><A NAME="10_1_1">Key</A></H3> -<TABLE BORDER="1"> -<TR><TD><FONT color="#00cc00">Yes</FONT></TD><TD>People report that this - works for them.</TD></TR> -<TR><TD>[Blank]</TD><TD>We don't know.</TD></TR> -<TR><TD><FONT color="#cc0000">No</FONT></TD><TD>We have reason to - believe it was, at some point, not possible to get this to work.</TD></TR> -<TR><TD><FONT color="#cccc00">Partial</FONT></TD><TD>Partial success. - For example, a connection can be created from one end only.</TD></TR> -<TR><TD><FONT color="#00cc00">Yes</FONT><FONT color="#cccc00">/Partial</FONT> -</TD><TD>Mixed reports.</TD></TR> -<TR><TD><FONT color="#cccc00">Maybe</FONT></TD><TD>We think the answer - is "yes", but need confirmation.</TD></TR> -</TABLE> -<A NAME="interoprules"></A> -<H2><A NAME="10_2">Basic Interop Rules</A></H2> -<P>Vanilla FreeS/WAN implements<A HREF="compat.html#compat"> these parts</A> - of the IPSec specifications. You can add more with<A HREF="http://www.freeswan.ca"> - Super FreeS/WAN</A>, but what we offer may be enough for many users.</P> -<UL> -<LI> To use X.509 certificates with FreeS/WAN, you will need the<A HREF="http://www.strongsec.org/freeswan"> - X.509 patch</A> or<A HREF="http://www.freeswan.ca"> Super FreeS/WAN</A> -, which includes that patch.</LI> -<LI> To use<A HREF="glossary.html#NAT.gloss"> Network Address - Translation</A> (NAT) traversal with FreeS/WAN, you will need Arkoon - Network Security's<A HREF="http://open-source.arkoon.net"> NAT - traversal patch</A> or<A HREF="http://www.freeswan.ca"> Super FreeS/WAN</A> -, which includes it.</LI> -</UL> -<P>We offer a set of proposals which is not user-adjustable, but covers - all combinations that we can offer. FreeS/WAN always proposes triple - DES encryption and Perfect Forward Secrecy (PFS). In addition, we - propose Diffie Hellman groups 5 and 2 (in that order), and MD5 and - SHA-1 hashes. We accept the same proposals, in the same order of - preference.</P> -<P>Other interop notes:</P> -<UL> -<LI> A<A HREF="http://lists.freeswan.org/archives/users/2003-September/msg00462.html"> - SHA-1 bug in FreeS/WAN 2.00, 2.01 and 2.02</A> may affect some interop - scenarios. It does not affect 1.x versions, and is fixed in 2.03 and - later.</LI> -<LI> Some other implementations will close a connection with FreeS/WAN - after some time. This may be a problem with rekey lifetimes. Please see<A -HREF="http://lists.freeswan.org/archives/users/2003-October/msg00293.html"> - this tip</A> and<A HREF="http://lists.freeswan.org/pipermail/users/2001-December/005758.html"> - this workaround</A>.</LI> -</UL> -<H2><A NAME="10_3">Longer Stories</A></H2> -<H3><A NAME="10_3_1">For<EM> More Compatible</EM> Implementations</A></H3> -<H4><A NAME="freeswan">FreeS/WAN</A></H4> -<P> See our documentation at<A HREF="http://www.freeswan.org"> - freeswan.org</A> and the Super FreeS/WAN docs at<A HREF="http://www.freeswan.ca"> - freeswan.ca</A>. Some user-written HOWTOs for FreeS/WAN-FreeS/WAN - connections are listed in<A HREF="intro.html#howto"> our Introduction</A> -.</P> -<P>See also:</P> -<UL> -<LI><A HREF="http://lugbe.ch/action/reports/ipsec_htbe.phtml"> A German - FreeS/WAN-FreeS/WAN page by Markus Wernig (X.509)</A></LI> -</UL> -<P><A HREF="#freeswan.top">Back to chart</A></P> -<H4><A NAME="isakmpd">isakmpd (OpenBSD)</A></H4> -<P><A HREF="http://www.openbsd.org/faq/faq13.html">OpenBSD FAQ: Using - IPsec</A> -<BR><A HREF="http://www.rommel.stw.uni-erlangen.de/~hshoexer/ipsec-howto/HOWTO.html"> - Hans-Joerg Hoexer's interop Linux-OpenBSD (PSK)</A> -<BR><A HREF="http://www.segfault.net/ipsec/"> Skyper's configuration - (PSK)</A> -<BR><A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> - French page with configs (X.509)</A></P> -<P><A HREF="#isakmpd.top">Back to chart</A></P> -<H4><A NAME="kame">Kame</A></H4> -<UL> -<LI>For FreeBSD and NetBSD. Ships with Mac OS X; see also our<A HREF="#apple"> - Mac</A> section.</LI> -<LI>Also known as<EM> racoon</EM>, its keying daemon.</LI> -</UL> -<P><A HREF="http://www.kame.net">Kame homepage, with FAQ</A> -<BR><A HREF="http://www.netbsd.org/Documentation/network/ipsec"> - NetBSD's IPSec FAQ</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/12/msg00560.html"> - Ghislaine's post explaining some interop peculiarities</A></P> -<P><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/09/msg00511.html"> - Itojun's Kame-FreeS/WAN interop tips (PSK)</A> -<BR><A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2000"> Ghislaine - Labouret's French page with links to matching FreeS/WAN and Kame - configs (RSA)</A> -<BR><A HREF="http://lugbe.ch/lostfound/contrib/freebsd_router/"> Markus - Wernig's HOWTO (X.509, BSD gateway)</A> -<BR><A HREF="http://web.morgul.net/~frodo/docs/kame+freeswan_interop.html"> - Frodo's Kame-FreeS/WAN interop (X.509)</A> -<BR><A HREF="http://www.wavesec.org/kame.phtml"> Kame as a WAVEsec - client.</A></P> -<P><A HREF="#kame.top">Back to chart</A></P> -<H4><A NAME="mcafee">PGPNet/McAfee</A></H4> -<P></P> -<UL> -<LI>Now called McAfee VPN Client.</LI> -<LI>PGPNet also came in a freeware version which did not support subnets</LI> -<LI>To support dhcp-over-ipsec, you need the X.509 patch, which is - included in<A HREF="http://www.freeswan.ca"> Super FreeS/WAN</A>.</LI> -</UL> -<P><A HREF="http://www.freeswan.ca/docs/WindowsInterop"> Tim Carr's - Windows Interop Guide (X.509)</A> -<BR><A HREF="http://www.rommel.stw.uni-erlangen.de/~hshoexer/ipsec-howto/HOWTO.html#Interop2"> - Hans-Joerg Hoexer's Guide for Linux-PGPNet (PSK)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/04/msg00339.html"> - Kai Martius' instructions using RSA Key-Extractor Tool (RSA)</A> -<BR> <A HREF="http://www.zengl.net/freeswan/english.html">Christian - Zeng's page (RSA)</A> based on Kai's work. English or German. -<BR><A HREF="http://tirnanog.ls.fi.upm.es/CriptoLab/Biblioteca/InfTech/InfTech_CriptoLab.htm"> - Oscar Delgado's PDF (X.509, no configs)</A> -<BR><A HREF="http://www-ec.njit.edu/~rxt1077/Howto.txt"> Ryan's HOWTO - for FreeS/WAN-PGPNet (X.509)</A>. Through a Linksys Router with IPsec - Passthru enabled. -<BR><A HREF="http://jixen.tripod.com/#RW-PGP-to-Fwan"> Jean-Francois - Nadeau's Practical Configuration (Road Warrior with PSK)</A> -<BR><A HREF="http://www.evolvedatacom.nl/freeswan.html#toc"> Wouter - Prins' HOWTO (Road Warrior with X.509)</A> -<BR></P> -<P><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/01/msg00271.html"> - Rekeying problem with FreeS/WAN and older PGPNets</A> -<BR></P> -<P><A HREF="http://www.strongsec.com/freeswan/dhcprelay/index.htm"> DHCP - over IPSEC HOWTO for FreeS/WAN (requires X.509 and dhcprelay patches)</A> -</P> -<P><A HREF="#mcafee.top">Back to chart</A></P> -<H4><A NAME="microsoft">Microsoft Windows 2000/XP</A></H4> -<UL> -<LI>IPsec comes with Win2k, and with XP Support Tools. May require<A HREF="http://www.microsoft.com/windows2000/downloads/recommended/encryption/default.asp"> - High Encryption Pack</A>. WinXP users have also reported better results - with Service Pack 1.</LI> -<LI>The Road Warrior setup works either way round. Windows (XP or 2K) - IPsec can connect as a Road Warrior to FreeS/WAN. However, FreeS/WAN - can also successfully connect as a Road Warrior to Windows IPsec (see - Nate Carlson's configs below).</LI> -<LI>FreeS/WAN version 1.92 or later is required to avoid an - interoperation problem with Windows native IPsec. Earlier FreeS/WAN - versions did not process the Commit Bit as Windows native IPsec - expected.</LI> -</UL> -<P><A HREF="http://www.freeswan.ca/docs/WindowsInterop"> Tim Carr's - Windows Interop Guide (X.509)</A> -<BR><A HREF="http://ipsec.math.ucla.edu/services/ipsec.html"> James - Carter's instructions (X.509, NAT-T)</A> -<BR><A HREF="http://jixen.tripod.com/#Win2000-Fwan"> Jean-Francois - Nadeau's Net-net Configuration (PSK)</A> -<BR><A HREF="http://security.nta.no/freeswan-w2k.html"> Telenor's - Node-node Config (Transport-mode PSK)</A> -<BR><A HREF="http://vpn.ebootis.de"> Marcus Mueller's HOWTO using his - VPN config tool (X.509).</A> Tool also works with PSK. -<BR><A HREF="http://www.natecarlson.com/include/showpage.php?cat=linux&page=ipsec-x509"> - Nate Carlson's HOWTO using same tool (Road Warrior with X.509)</A>. - Unusually, FreeS/WAN is the Road Warrior here. -<BR><A HREF="http://tirnanog.ls.fi.upm.es/CriptoLab/Biblioteca/InfTech/InfTech_CriptoLab.htm"> - Oscar Delgado's PDF (X.509, no configs)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2003-July/022425.html"> - Tim Scannell's Windows XP Additional Checklist (X.509)</A> -<BR></P> - -<!-- Note to self: Include L2TP references? --> -<P><A HREF="http://www.microsoft.com/windows2000/en/server/help/default.asp?url=/windows2000/en/server/help/sag_TCPIP_ovr_secfeatures.htm"> - Microsoft's page on Win2k TCP/IP security features</A> -<BR><A HREF="http://support.microsoft.com/support/kb/articles/Q257/2/25.ASP"> - Microsoft's Win2k IPsec debugging tips</A> -<BR> -<!-- Alt-URL http://support.microsoft.com/default.aspx?scid=kb;EN-US;q257225 -Perhaps newer? --> -<A HREF="http://www.wired.com/news/technology/0,1282,36336,00.html"> - MS VPN may fall back to 1DES</A></P> -<P><A HREF="#microsoft.top">Back to chart</A></P> -<H4><A NAME="ssh">SSH Sentinel</A></H4> -<UL> -<LI>Popular and well tested.</LI> -<LI>Also rebranded in<A HREF="http://www.zyxel.com"> Zyxel Zywall</A>. - Our Zyxel interop notes are<A HREF="#zyxel"> here</A>.</LI> -<LI> SSH supports IPsec-over-UDP NAT traversal.</LI> -<LI>There is this<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/12/msg00370.html"> - potential problem</A> if you're not using the Legacy Proposal option.</LI> -</UL> -<P><A HREF="http://www.ssh.com/support/sentinel/documents.cfm"> SSH's - Sentinel-FreeSWAN interop PDF (X.509)</A> -<BR><A HREF="http://www.nadmm.com/show.php?story=articles/vpn.inc"> - Nadeem Hassan's SUSE-to-Sentinel article (Road warrior with X.509)</A> -<BR><A HREF="http://www.zerozone.it/documents/Linux/HowTo/VPN-IPsec-Freeswan-HOWTO.html"> - O-Zone's Italian HOWTO (Road Warrior, X.509, DHCP)</A> -<BR></P> -<P><A HREF="#ssh.top">Back to chart</A></P> -<H4><A NAME="safenet">Safenet SoftPK/SoftRemote</A></H4> -<UL> -<LI>People recommend SafeNet as a low cost Windows client.</LI> -<LI>SoftRemote seems to be the newer name for SoftPK.</LI> -</UL> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005061.html"> - Whit Blauvelt's SoftRemote tips</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-October/015591.html"> - Tim Wilson's tips (X.509)</A><A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00607.html"> - Workaround for a "gotcha"</A></P> -<P><A HREF="http://jixen.tripod.com/#Rw-IRE-to-Fwan"> Jean-Francois - Nadeau's Practical Configuration (Road Warrior with PSK)</A> -<BR><A HREF="http://www.terradoncommunications.com/security/whitepapers/safe_net-to-free_swan.pdf"> - Terradon Communications' PDF (Road Warrior with PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-October/?????.html"> - Seaan.net's PDF (Road Warrior to Subnet, with PSK)</A> -<BR><A HREF="http://www.redbaronconsulting.com/freeswan/fswansafenet.pdf"> - Red Baron Consulting's PDF (Road Warrior with X.509)</A></P> -<P><A HREF="#safenet.top">Back to chart</A></P> -<H3><A NAME="10_3_2">For<EM> Other Implementations</EM></A></H3> -<H4><A NAME="6wind">6Wind</A></H4> -<P><A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> - French page with configs (X.509)</A></P> -<P><A HREF="#6wind.top">Back to chart</A></P> -<H4><A NAME="alcatel">Alcatel Timestep</A></H4> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-June/011878.html"> - Alain Sabban's settings (PSK or PSK road warrior; through static NAT)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/1999/06/msg00100.html"> - Derick Cassidy's configs (PSK)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/1999/08/msg00194.html"> - David Kerry's Timestep settings (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-August/013711.html"> - Kevin Gerbracht's ipsec.conf (X.509)</A></P> -<P><A HREF="#alcatel.top">Back to chart</A></P> -<H4><A NAME="apple">Apple Macintosh System 10+</A></H4> -<UL> -<LI>Since the system is based on FreeBSD, this should interoperate<A HREF="#kame"> - just like FreeBSD</A>.</LI> -<LI> To use Appletalk over IPsec tunnels,<A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005116.html"> - run it over TCP/IP</A>, or use Open Door Networks' Shareway IP tool,<A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005426.html"> - described here.</A></LI> -<LI>See also the<A HREF="#equinux"> Equinux VPN Tracker</A> for Mac OS - X.</LI> -</UL> -<P><A HREF="http://ipsec.math.ucla.edu/services/ipsec.html"> James - Carter's instructions (X.509, NAT-T)</A></P> -<P><A HREF="#apple.top">Back to chart</A></P> -<H4><A NAME="ashleylaurent">AshleyLaurent VPCom</A></H4> -<P><A HREF="http://www.ashleylaurent.com/newsletter/01-28-00.htm"> - Successful interop report, no details</A></P> -<P><A HREF="#ashleylaurent.top">Back to chart</A></P> -<H4><A NAME="borderware">Borderware</A></H4> -<UL> -<LI>I suspect the Borderware client is a rebranded Safenet. If that's - true, our<A HREF="#safenet"> Safenet section</A> will help.</LI> -</UL> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-March/008288.html"> - Philip Reetz' configs (PSK)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/09/msg00217.html"> - Borderware server does not support FreeS/WAN road warriors</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-February/007733.html"> - Older Borderware may not support Diffie Hellman groups 2, 5</A> -<BR></P> -<P><A HREF="#borderware.top">Back to chart</A></P> -<H4><A NAME="checkpoint">Check Point VPN-1 or FW-1</A></H4> -<UL> -<LI><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00099.html"> - Caveat about IP-range inclusion on Check Point.</A></LI> -<LI> Some versions of Check Point may require an aggressive mode patch - to interoperate with FreeS/WAN. -<BR><A HREF="http://www.freeswan.ca/code/super-freeswan"> Super - FreeS/WAN</A> now features this patch. -<!-- -<A HREF="http://www.freeswan.ca/patches/aggressivemode">Steve Harvey's -aggressive mode patch for FreeS/WAN 1.5</A> ---> -</LI> -<LI></LI> -<LI>A Linux FreeS/WAN-Checkpoint connection may close after some time. - Try<A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00293.html"> - this tip</A> toward a workaround.</LI> -</UL> -<P><A HREF="http://www.fw-1.de/aerasec/ng/vpn-freeswan/CPNG+Linux-FreeSWAN.html"> - AERAsec's Firewall-1 NG site (PSK, X.509, Road Warrior with X.509, - other algorithms)</A> -<BR> <A HREF="http://www.fw-1.de/aerasec/ng/vpn-freeswan/CPNG+Linux-FreeSWAN.html#support-matrix"> - AERAsec's detailed Check Point-FreeS/WAN support matrix</A> -<BR><A HREF="http://support.checkpoint.com/kb/docs/public/firewall1/4_1/pdf/fw-linuxvpn.pdf"> - Checkpoint.com PDF: Linux as a VPN Client to FW-1 (PSK)</A> -<BR><A HREF="http://www.phoneboy.com"> PhoneBoy's Check Point FAQ (on - Check Point only, not FreeS/WAN)</A> -<BR></P> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2001-August/002351.html"> - Chris Harwell's tips FreeS/WAN configs (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-April/009362.html"> - Daniel Tombeil's configs (PSK)</A></P> -<P><A HREF="#checkpoint.top">Back to chart</A></P> -<H4><A NAME="cisco">Cisco</A></H4> -<UL> -<LI> Cisco supports IPsec-over-UDP NAT traversal.</LI> -<LI>Cisco VPN Client appears to use nonstandard IPsec and does not work - with FreeS/WAN.<A HREF="https://mj2.freeswan.org/archives/2003-August/maillist.html"> - This message</A> concerns Cisco VPN Client 4.01. -<!-- fix link --> -</LI> -<LI>A Linux FreeS/WAN-Cisco connection may close after some time.<A HREF="http://lists.freeswan.org/pipermail/users/2001-December/005758.html"> - Here</A> is a workaround, and<A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00293.html"> - here</A> is another comment on the same subject.</LI> -<LI><A HREF="http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t2/3desips.htm"> -Older Ciscos</A> purchased outside the United States may not have 3DES, - which FreeS/WAN requires.</LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2001-June/000406.html"> -RSA keying may not be possible between Cisco and FreeS/WAN.</A></LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2001-October/004357.html"> -In ipsec.conf, VPN3000 DN (distinguished name) must be in binary (X.509 - only)</A></LI> -</UL> -<P><A HREF="http://rr.sans.org/encryption/cisco_router.php"> SANS - Institute HOWTO (PSK).</A> Detailed, with extensive references. -<BR><A HREF="http://www.worldbank.ro/IPSEC/cisco-linux.txt"> Short HOWTO - (PSK)</A> -<BR><A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> - French page with configs for Cisco IOS, PIX and VPN 3000 (X.509)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2001-August/002966.html"> - Dave McFerren's sample configs (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2001-September/003422.html"> - Wolfgang Tremmel's sample configs (PSK road warrior)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/11/msg00578.html"> - Old doc from Pete Davis, with William Watson's updated Tips (PSK)</A> -<BR></P> -<P><STRONG>Some PIX specific information:</STRONG> -<BR><A HREF="http://www.wlug.org.nz/FreeSwanToCiscoPix"> Waikato Linux - Users' Group HOWTO. Nice detail (PSK)</A> -<BR><A HREF="http://www.johnleach.co.uk/documents/freeswan-pix/freeswan-pix.html"> - John Leach's configs (PSK)</A> -<BR><A HREF="http://www.diverdown.cc/vpn/freeswanpix.html"> Greg - Robinson's settings (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-February/007901.html"> - Scott's ipsec.conf for PIX (PSK, FreeS/WAN side only)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2001-October/003949.html"> - Rick Trimble's PIX and FreeS/WAN settings (PSK)</A> -<BR></P> -<P><A href="http://www.cisco.com/public/support/tac"> Cisco VPN support - page</A> -<BR><A href="http://www.ieng.com/warp/public/707/index.shtml#ipsec"> - Cisco IPsec information page</A></P> -<P><A HREF="#cisco.top">Back to chart</A></P> -<H4><A NAME="equinux">Equinux VPN tracker (for Mac OS X)</A></H4> -<UL> -<LI>Graphical configurator for Mac OS X IPsec. May be an interface to - the<A HREF="#apple"> native Mac OS X IPsec</A>, which is essentially<A HREF="#kame"> - KAME</A>.</LI> -<LI>To use Appletalk over IPsec tunnels,<A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005116.html"> - run it over TCP/IP</A>, or use Open Door Networks' Shareway IP tool,<A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005426.html"> - described here.</A></LI> -</UL> -<P> Equinux provides<A HREF="http://www.equinux.com/download/HowTo_FreeSWAN.pdf"> - this excellent interop PDF</A> (PSK, RSA, X.509).</P> -<P><A HREF="#equinux.top">Back to chart</A></P> -<H4><A NAME="fsecure">F-Secure</A></H4> -<UL> -<LI> -<!-- <A HREF="http://lists.freeswan.org/pipermail/users/2002-February/007596.html"> --> - F-Secure supports IPsec-over-UDP NAT traversal.</LI> -</UL> -<P><A HREF="http://www.pingworks.de/tech/vpn/vpn.txt">pingworks.de's - "Connecting F-Secure's VPN+ to Linux FreeS/WAN" (PSK road warrior)</A> -<BR> <A HREF="http://www.pingworks.de/tech/vpn/vpn.pdf">Same thing - as PDF</A> -<BR><A HREF="http://www.exim.org/pipermail/linux-ipsec/Week-of-Mon-20010122/000061.html"> - Success report, no detail (PSK)</A> -<BR><A HREF="http://www.exim.org/pipermail/linux-ipsec/Week-of-Mon-20010122/000041.html"> - Success report, no detail (Manual)</A></P> - -<!-- Other NAT traversers: -http://lists.freeswan.org/pipermail/users/2002-April/009136.html -and ssh sentinel: -http://lists.freeswan.org/pipermail/users/2001-September/003108.html ---> -<P><A HREF="#fsecure.top">Back to chart</A></P> -<H4><A NAME="gauntlet">Gauntlet GVPN</A></H4> -<P><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/11/msg00535.html"> - Richard Reiner's ipsec.conf (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-June/011434.html"> - Might work without that pesky firewall... (PSK)</A> -<BR> -<!-- insert archive link --> - In late July, 2003 Alexandar Antik reported success interoperating - with Gauntlet 6.0 for Solaris (X.509). Unfortunately the message is not - properly archived at this time.</P> -<P><A HREF="#gauntlet.top">Back to chart</A></P> -<H4><A NAME="aix">IBM AIX</A></H4> -<P><A HREF="http://www-1.ibm.com/servers/esdd/articles/security.html"> - IBM's "Built-In Network Security with AIX" (PSK, X.509)</A> -<BR><A HREF="http://www-1.ibm.com/servers/aix/products/ibmsw/security/vpn/faqandtips/#ques20"> - IBM's tip: importing Linux FreeS/WAN settings into AIX's<VAR> ikedb</VAR> - (PSK)</A></P> -<P><A HREF="#aix.top">Back to chart</A></P> -<H4><A NAME="as400">IBM AS/400</A></H4> -<UL> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2002-April/009106.html"> - Road Warriors may act flaky</A>.</LI> -</UL> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-September/014264.html"> - Richard Welty's tips and tricks</A> -<BR></P> -<P><A HREF="#as400.top">Back to chart</A></P> -<H4><A NAME="intel">Intel Shiva LANRover / Net Structure</A></H4> -<UL> -<LI>Intel Shiva LANRover is now known as Intel Net Structure.</LI> -<LI><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/01/msg00298.html"> - Shiva seems to have two modes: IPsec or the proprietary "Shiva Tunnel".</A> - Of course, FreeS/WAN will only create IPsec tunnels.</LI> -<LI><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00293.html"> - AH may not work for Shiva-FreeS/WAN.</A> That's OK, since FreeS/WAN has - phased out the use of AH.</LI> -</UL> -<P><A HREF="http://snowcrash.tdyc.com/freeswan/"> Snowcrash's configs - (PSK)</A> -<BR><A HREF="http://www.opus1.com/vpn/index.html"> Old configs from an - interop (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2001-October/003831.html"> - The day Shiva tickled a Pluto bug (PSK)</A> -<BR> <A HREF="http://lists.freeswan.org/pipermail/users/2001-October/004270.html"> - Follow up: success!</A></P> -<P><A HREF="#intel.top">Back to chart</A></P> -<H4><A NAME="lancom">LanCom (formerly ELSA)</A></H4> -<UL> -<LI>This router is popular in Germany.</LI> -</UL> -<P> Jakob Curdes successfully created a PSK connection with the LanCom - 1612 in August 2003. -<!-- add ML link when it appears --> -</P> -<P><A HREF="#lancom.top">Back to chart</A></P> -<H4><A NAME="linksys">Linksys</A></H4> -<UL> -<LI>Linksys may be used as an IPsec tunnel endpoint,<STRONG> OR</STRONG> - as a router in "IPsec passthrough" mode, so that the IPsec tunnel - passes through the Linksys.</LI> -</UL> -<H5>As tunnel endpoint</H5> -<P><A HREF="http://www.freeswan.ca/docs/BEFVP41/"> Ken Bantoft's - instructions (Road Warrior with PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-February/007814.html"> - Nate Carlson's caveats</A></P> -<H5>In IPsec passthrough mode</H5> -<P><A HREF="http://www-ec.njit.edu/~rxt1077/Howto.txt"> Sample HOWTO - through a Linksys Router</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2002/02/msg00114.html"> - Nadeem Hasan's configs</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2002/02/msg00180.html"> - Brock Nanson's tips</A> -<BR></P> -<P><A HREF="#linksys.top">Back to chart</A></P> -<H4><A NAME="lucent">Lucent</A></H4> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-May/010976.html"> - Partial success report; see also the next message in thread</A></P> - -<!-- section done --> -<P><A HREF="#lucent.top">Back to chart</A></P> -<H4><A NAME="netasq">Netasq</A></H4> -<P><A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> - French page with configs (X.509)</A></P> - -<!-- section done --> -<P><A HREF="#netasq.top">Back to chart</A></P> -<H4><A NAME="netcelo">Netcelo</A></H4> -<P><A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> - French page with configs (X.509)</A> -<!-- section done --> -</P> -<P><A HREF="#netcelo.top">Back to chart</A></P> -<H4><A NAME="netgear">Netgear fvs318</A></H4> -<UL> -<LI>With a recent Linux FreeS/WAN, you will require the latest (12/2002) - Netgear firmware, which supports Diffie-Hellman (DH) group 2. For - security reasons, we phased out DH 1 after Linux FreeS/WAN 1.5.</LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2002-June/011833.html"> - This message</A> reports the incompatibility between Linux FreeS/WAN - 1.6+ and Netgear fvs318 without the firmware upgrade.</LI> -<LI>We believe Linux FreeS/WAN 1.5 and earlier will interoperate with - any NetGear firmware.</LI> -</UL> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2003-February/017891.html"> - John Morris' setup (PSK)</A></P> -<P><A HREF="#netgear.top">Back to chart</A></P> -<H4><A NAME="netscreen">Netscreen 100 or 5xp</A></H4> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-August/013409.html"> - Errol Neal's settings (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-October/015265.html"> - Corey Rogers' configs (PSK, no PFS)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-August/013051.html"> - Jordan Share's configs (PSK, 2 subnets, through static NAT)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/08/msg00404.html"> - Set src proxy_id to your protected subnet/mask</A> -<BR><A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> - French page with ipsec.conf, Netscreen screen shots (X.509, may need to - revert to PSK...)</A></P> -<P><A HREF="http://archives.neohapsis.com/archives/sf/linux/2001-q2/0123.html"> - A report of a company using Netscreen with FreeS/WAN on a large scale - (FreeS/WAN road warriors?)</A></P> -<P><A HREF="#netscreen.top">Back to chart</A></P> -<H4><A NAME="nortel">Nortel Contivity</A></H4> -<UL> -<LI> Nortel supports IPsec-over-UDP NAT traversal.</LI> -<LI><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00417.html"> - Some older versions of Contivity and FreeS/WAN will not communicate.</A> -</LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2002-May/010924.html"> - FreeS/WAN cannot be used as a "client" to a Nortel Contivity server, - but can be used as a branch-office tunnel.</A></LI> - -<!-- Probably obsoleted by Ken's post -<LI> -(Matthias siebler from old interop) -At one point you could not configure Nortel-FreeS/WAN tunnels as -"Client Tunnels" since FreeS/WAN does not support Aggressive Mode. -Current status of this problem: unknown. -<LI> -<A HREF="http://lists.freeswan.org/pipermail/users/2001-November/004612.html"> -How do we map group and user passwords onto the data that FreeS/WAN wants? -</A> -</LI> ---> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2002-October/015455.html"> - Contivity does not send Distinguished Names in the order FS wants them - (X.509).</A></LI> -<LI><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/03/msg00137.html"> - Connections may time out after 30-40 minutes idle.</A></LI> -</UL> -<P><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/03/msg00137.html"> - JJ Streicher-Bremer's mini HOWTO for old new software. (PSK with two - subnets)</A> -<BR><A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> - French page with configs (X.509)</A>. This succeeds using the above - X.509 tip.</P> - -<!-- I could do more searching but this is a solid start. --> -<P><A HREF="#nortel.top">Back to chart</A></P> -<H4><A NAME="radguard">Radguard</A></H4> -<P><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/05/msg00009.html"> - Marko Hausalo's configs (PSK).</A> Note: These do create a connection, - as you can see by "IPsec SA established". -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-October/???.html"> - Claudia Schmeing's comments</A></P> -<P><A HREF="#radguard.top">Back to chart</A></P> -<H4><A NAME="raptor">Raptor (NT or Solaris)</A></H4> -<P></P> -<UL> -<LI>Now known as Symantec Enterprise Firewall.</LI> -<LI>The Raptor does not normally come with X.509, but this may be - available as an add-on.</LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2002-May/010256.html"> - Raptor requires alphanumberic PSK values, whereas FreeS/WAN uses hex.</A> -</LI> -<LI>Raptor's tunnel endpoint may be a host, subnet or group of subnets - (see<A HREF="http://lists.freeswan.org/pipermail/design/2001-November/001295.html"> - this message</A> ). FreeS/WAN cannot handle the group of subnets; you - must create separate connections for each in order to interoperate.</LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2002-May/010113.html"> - Some versions of Raptor accept only single DES.</A> According to this - German message,<A HREF="http://radawana.cg.tuwien.ac.at/mail-archives/lll/200012/msg00065.html"> - the Raptor Mobile Client demo offers single DES only.</A></LI> -</UL> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-January/006935.html"> - Peter Mazinger's settings (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005522.html"> - Peter Gerland's configs (PSK)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/07/msg00597.html"> - Charles Griebel's configs (PSK).</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-July/012275.html"> - Lumir Srch's tips (PSK)</A></P> -<P><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/05/msg00214.html"> - John Hardy's configs (Manual)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/01/msg00236.html"> - Older Raptors want 3DES keys in 3 parts (Manual).</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/06/msg00480.html"> - Different keys for each direction? (Manual)</A> -<BR></P> -<P><A HREF="#raptor.top">Back to chart</A></P> -<H4><A NAME="redcreek">Redcreek Ravlin</A></H4> -<UL> -<LI>Known issue #1: The Ravlin expects a quick mode renegotiation right - after every Main Mode negotiation.</LI> -<LI> Known issue #2: The Ravlin tries to negotiate a zero connection - lifetime, which it takes to mean "infinite".<A HREF="http://www.bear-cave.org.uk/linux/ravlin/"> - Jim Hague's patch</A> addresses both issues.</LI> -<LI><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/03/msg00191.html"> - Interop works with Ravlin Firmware > 3.33. Includes tips (PSK).</A></LI> -</UL> -<P><A HREF="#redcreek.top">Back to chart</A></P> -<H4><A NAME="sonicwall">SonicWall</A></H4> -<UL> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2001-June/000998.html"> - Sonicwall cannot be used for Road Warrior setups</A></LI> -<LI> At one point,<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/05/msg00217.html"> - only Sonicwall PRO supported triple DES</A>.</LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2002-March/008600.html"> - Older Sonicwalls (before Nov 2001) feature Diffie Hellman group 1 only</A> -.</LI> -</UL> -<P><A HREF="http://www.xinit.cx/docs/freeswan.html"> Paul Wouters' - config (PSK)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00073.html"> - Dilan Arumainathan's configuration (PSK)</A> -<BR><A HREF="http://www.gravitas.co.uk/vpndebug"> Dariush's setup... - only opens one way (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2003-July/022302.html"> - Andreas Steffen's tips (X.509)</A> -<BR></P> -<P><A HREF="#sonicwall.top">Back to chart</A></P> -<H4><A NAME="sun">Sun Solaris</A></H4> -<UL> -<LI> Solaris 8+ has a native (in kernel) IPsec implementation.</LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2002-May/010503.html"> - Solaris does not seem to support tunnel mode, but you can make IP-in-IP - tunnels instead, like this.</A></LI> -</UL> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2003-June/022216.html"> - Reports of some successful interops</A> from a fellow @sun.com. See - also<A HREF="http://lists.freeswan.org/pipermail/users/2003-July/022247.html"> - these follow up posts</A>. -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/03/msg00332.html"> - Aleks Shenkman's configs (Manual in transport mode)</A> -<BR> -<!--sparc 64 stuff goes where?--> -</P> -<P><A HREF="#solaris.top">Back to chart</A></P> -<H4><A NAME="symantec">Symantec</A></H4> -<UL> -<LI>The Raptor, covered<A HREF="#raptor"> above</A>, is now known as - Symantec Enterprise Firewall.</LI> -<LI>Symantec's "distinguished name" is a KEY_ID. See Andreas Steffen's - post, below.</LI> -</UL> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-April/009037.html"> - Andreas Steffen's configs for Symantec 200R (PSK)</A></P> -<P><A HREF="#symantec.top">Back to chart</A></P> -<H4><A NAME="watchguard">Watchguard Firebox</A></H4> -<UL> -<LI>Automatic keying works with WatchGuard 5.0+ only.</LI> -<LI>Seen to interoperate with WatchGuard 1000, II, III; firmware v. 5, - 6..</LI> -<LI>For manual keying, Watchguard's Policy Manager expects SPI numbers - and encryption and authentication keys in decimal (not hex).</LI> -</UL> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-July/012595.html"> - WatchGuard's HOWTO (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-August/013342.html"> - Ronald C. Riviera's Settings (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00179.html"> - Walter Wickersham's Notes (PSK)</A> -<BR><A HREF="http://lists.freeswan.org/pipermail/users/2002-October/015587.html"> - Max Enders' Configs (Manual)</A></P> -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-April/009404.html"> - Old known issue with auto keying</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00124.html"> - Tips on key generation and format (Manual)</A> -<BR></P> -<P><A HREF="#watchguard.top">Back to chart</A></P> -<H4><A NAME="xedia">Xedia Access Point/QVPN</A></H4> -<P><A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/12/msg00520.html"> - Hybrid IPsec/L2TP connection settings (X.509)</A> -<BR><A HREF="http://www.sandelman.ottawa.on.ca/ipsec/1999/08/msg00140.html"> - Xedia's LAN-LAN links don't use multiple tunnels</A> -<BR> <A HREF="http://www.sandelman.ottawa.on.ca/ipsec/1999/08/msg00140.html"> - That explanation, continued</A></P> -<P><A HREF="#xedia.top">Back to chart</A></P> -<H4><A NAME="zyxel">Zyxel</A></H4> -<UL> -<LI>The Zyxel Zywall is a rebranded SSH Sentinel box. See also our - section on<A HREF="glossary.html#ssh"> SSH</A>.</LI> -<LI>There seems to be a problem with keeping this connection alive. This - is caused at the Zyxel end. See this brief<A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00141.html"> - discussion and solution.</A></LI> -</UL> -<P><A HREF="http://www.zyxel.com/support/supportnote/zywall/app/zw_freeswan.htm"> - Zyxel's Zywall to FreeS/WAN instructions (PSK)</A> -<BR><A HREF="http://www.zyxel.com/support/supportnote/p652/app/zw_freeswan.htm"> - Zyxel's Prestige to FreeS/WAN instructions (PSK)</A>. Note: not all - Prestige versions include VPN software. -<BR><A HREF="http://www.lancry.net/techdocs/freeswan-zyxel.txt"> Fabrice - Cahen's HOWTO (PSK)</A> -<BR> </P> -<P><A HREF="#zyxel.top">Back to chart</A></P> - -<!-- SAMPLE ENTRY - -<H4><A NAME="timestep">Timestep</A></H4> - -<P>Text goes here. -</P> - ---> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="compat.html">Previous</A> -<A HREF="performance.html">Next</A> -</BODY> -</HTML> diff --git a/doc/intro.html b/doc/intro.html deleted file mode 100644 index 3afc3e324..000000000 --- a/doc/intro.html +++ /dev/null @@ -1,733 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="upgrading.html">Next</A> -<HR> -<H1><A name="intro">Introduction</A></H1> -<P>This section gives an overview of:</P> -<UL> -<LI>what IP Security (IPsec) does</LI> -<LI>how IPsec works</LI> -<LI>why we are implementing it for Linux</LI> -<LI>how this implementation works</LI> -</UL> -<P>This section is intended to cover only the essentials,<EM> things you - should know before trying to use FreeS/WAN.</EM></P> -<P>For more detailed background information, see the<A href="politics.html#politics"> - history and politics</A> and<A href="ipsec.html#ipsec.detail"> IPsec - protocols</A> sections.</P> -<H2><A name="ipsec.intro">IPsec, Security for the Internet Protocol</A></H2> -<P>FreeS/WAN is a Linux implementation of the IPsec (IP security) - protocols. IPsec provides<A href="glossary.html#encryption"> encryption</A> - and<A href="glossary.html#authentication"> authentication</A> services - at the IP (Internet Protocol) level of the network protocol stack.</P> -<P>Working at this level, IPsec can protect any traffic carried over IP, - unlike other encryption which generally protects only a particular - higher-level protocol --<A href="glossary.html#PGP"> PGP</A> for mail,<A -href="glossary.html#SSH"> SSH</A> for remote login,<A href="glossary.html#SSL"> - SSL</A> for web work, and so on. This approach has both considerable - advantages and some limitations. For discussion, see our<A href="ipsec.html#others"> - IPsec section</A></P> -<P>IPsec can be used on any machine which does IP networking. Dedicated - IPsec gateway machines can be installed wherever required to protect - traffic. IPsec can also run on routers, on firewall machines, on - various application servers, and on end-user desktop or laptop - machines.</P> -<P>Three protocols are used</P> -<UL> -<LI><A href="glossary.html#AH">AH</A> (Authentication Header) provides a - packet-level authentication service</LI> -<LI><A href="glossary.html#ESP">ESP</A> (Encapsulating Security Payload) - provides encryption plus authentication</LI> -<LI><A href="glossary.html#IKE">IKE</A> (Internet Key Exchange) - negotiates connection parameters, including keys, for the other two</LI> -</UL> -<P>Our implementation has three main parts:</P> -<UL> -<LI><A href="glossary.html#KLIPS">KLIPS</A> (kernel IPsec) implements - AH, ESP, and packet handling within the kernel</LI> -<LI><A href="glossary.html#Pluto">Pluto</A> (an IKE daemon) implements - IKE, negotiating connections with other systems</LI> -<LI>various scripts provide an adminstrator's interface to the machinery</LI> -</UL> -<P>IPsec is optional for the current (version 4) Internet Protocol. - FreeS/WAN adds IPsec to the Linux IPv4 network stack. Implementations - of<A href="glossary.html#ipv6.gloss"> IP version 6</A> are required to - include IPsec. Work toward integrating FreeS/WAN into the Linux IPv6 - stack has<A href="compat.html#ipv6"> started</A>.</P> -<P>For more information on IPsec, see our<A href="ipsec.html#ipsec.detail"> - IPsec protocols</A> section, our collection of<A href="web.html#ipsec.link"> - IPsec links</A> or the<A href="rfc.html#RFC"> RFCs</A> which are the - official definitions of these protocols.</P> -<H3><A name="intro.interop">Interoperating with other IPsec - implementations</A></H3> -<P>IPsec is designed to let different implementations work together. We - provide:</P> -<UL> -<LI>a<A href="web.html#implement"> list</A> of some other - implementations</LI> -<LI>information on<A href="interop.html#interop"> using FreeS/WAN with - other implementations</A></LI> -</UL> -<P>The VPN Consortium fosters cooperation among implementers and - interoperability among implementations. Their<A href="http://www.vpnc.org/"> - web site</A> has much more information.</P> -<H3><A name="advantages">Advantages of IPsec</A></H3> -<P>IPsec has a number of security advantages. Here are some - independently written articles which discuss these:</P> -<P><A HREF="http://www.sans.org/rr/"> SANS institute papers</A>. See the - section on Encryption &VPNs. -<BR><A HREF="http://www.cisco.com/en/US/netsol/ns110/ns170/ns171/ns128/networking_solutions_white_papers_list.html"> - Cisco's white papers on "Networking Solutions"</A>. -<BR><A HREF="http://iscs.sourceforge.net/HowWhyBrief/HowWhyBrief.html"> - Advantages of ISCS (Linux Integrated Secure Communications System; - includes FreeS/WAN and other software)</A>.</P> -<H3><A name="applications">Applications of IPsec</A></H3> -<P>Because IPsec operates at the network layer, it is remarkably - flexible and can be used to secure nearly any type of Internet traffic. - Two applications, however, are extremely widespread:</P> -<UL> -<LI>a<A href="glossary.html#VPN"> Virtual Private Network</A>, or VPN, - allows multiple sites to communicate securely over an insecure Internet - by encrypting all communication between the sites.</LI> -<LI>"Road Warriors" connect to the office from home, or perhaps from a - hotel somewhere</LI> -</UL> -<P>There is enough opportunity in these applications that vendors are - flocking to them. IPsec is being built into routers, into firewall - products, and into major operating systems, primarily to support these - applications. See our<A href="web.html#implement"> list</A> of - implementations for details.</P> -<P>We support both of those applications, and various less common IPsec - applications as well, but we also add one of our own:</P> -<UL> -<LI>opportunistic encryption, the ability to set up FreeS/WAN gateways - so that any two of them can encrypt to each other, and will do so - whenever packets pass between them.</LI> -</UL> -<P>This is an extension we are adding to the protocols. FreeS/WAN is the - first prototype implementation, though we hope other IPsec - implementations will adopt the technique once we demonstrate it. See<A href="#goals"> - project goals</A> below for why we think this is important.</P> -<P>A somewhat more detailed description of each of these applications is - below. Our<A href="quickstart.html#quick_guide"> quickstart</A> section - will show you how to build each of them.</P> -<H4><A name="makeVPN">Using secure tunnels to create a VPN</A></H4> -<P>A VPN, or<STRONG> V</STRONG>irtual<STRONG> P</STRONG>rivate<STRONG> N</STRONG> -etwork lets two networks communicate securely when the only connection - between them is over a third network which they do not trust.</P> -<P>The method is to put a security gateway machine between each of the - communicating networks and the untrusted network. The gateway machines - encrypt packets entering the untrusted net and decrypt packets leaving - it, creating a secure tunnel through it.</P> -<P>If the cryptography is strong, the implementation is careful, and the - administration of the gateways is competent, then one can reasonably - trust the security of the tunnel. The two networks then behave like a - single large private network, some of whose links are encrypted tunnels - through untrusted nets.</P> -<P>Actual VPNs are often more complex. One organisation may have fifty - branch offices, plus some suppliers and clients, with whom it needs to - communicate securely. Another might have 5,000 stores, or 50,000 - point-of-sale devices. The untrusted network need not be the Internet. - All the same issues arise on a corporate or institutional network - whenever two departments want to communicate privately with each other.</P> -<P>Administratively, the nice thing about many VPN setups is that large - parts of them are static. You know the IP addresses of most of the - machines involved. More important, you know they will not change on - you. This simplifies some of the admin work. For cases where the - addresses do change, see the next section.</P> -<H4><A name="road.intro">Road Warriors</A></H4> -<P>The prototypical "Road Warrior" is a traveller connecting to home - base from a laptop machine. Administratively, most of the same problems - arise for a telecommuter connecting from home to the office, especially - if the telecommuter does not have a static IP address.</P> -<P>For purposes of this document:</P> -<UL> -<LI>anyone with a dynamic IP address is a "Road Warrior".</LI> -<LI>any machine doing IPsec processing is a "gateway". Think of the - single-user road warrior machine as a gateway with a degenerate subnet - (one machine, itself) behind it.</LI> -</UL> -<P>These require somewhat different setup than VPN gateways with static - addresses and with client systems behind them, but are basically not - problematic.</P> -<P>There are some difficulties which appear for some road warrior - connections:</P> -<UL> -<LI>Road Wariors who get their addresses via DHCP may have a problem. - FreeS/WAN can quite happily build and use a tunnel to such an address, - but when the DHCP lease expires, FreeS/WAN does not know that. The - tunnel fails, and the only recovery method is to tear it down and - re-build it.</LI> -<LI>If<A href="glossary.html#NAT.gloss"> Network Address Translation</A> - (NAT) is applied between the two IPsec Gateways, this breaks IPsec. - IPsec authenticates packets on an end-to-end basis, to ensure they are - not altered en route. NAT rewrites packets as they go by. See our<A href="firewall.html#NAT"> - firewalls</A> document for details.</LI> -</UL> -<P>In most situations, however, FreeS/WAN supports road warrior - connections just fine.</P> -<H4><A name="opp.intro">Opportunistic encryption</A></H4> -<P>One of the reasons we are working on FreeS/WAN is that it gives us - the opportunity to add what we call opportuntistic encryption. This - means that any two FreeS/WAN gateways will be able to encrypt their - traffic, even if the two gateway administrators have had no prior - contact and neither system has any preset information about the other.</P> -<P>Both systems pick up the authentication information they need from - the<A href="glossary.html#DNS"> DNS</A> (domain name service), the - service they already use to look up IP addresses. Of course the - administrators must put that information in the DNS, and must set up - their gateways with opportunistic encryption enabled. Once that is - done, everything is automatic. The gateways look for opportunities to - encrypt, and encrypt whatever they can. Whether they also accept - unencrypted communication is a policy decision the administrator can - make.</P> -<P>This technique can give two large payoffs:</P> -<UL> -<LI>It reduces the administrative overhead for IPsec enormously. You - configure your gateway and thereafter everything is automatic. The need - to configure the system on a per-tunnel basis disappears. Of course, - FreeS/WAN allows specifically configured tunnels to co-exist with - opportunistic encryption, but we hope to make them unnecessary in most - cases.</LI> -<LI>It moves us toward a more secure Internet, allowing users to create - an environment where message privacy is the default. All messages can - be encrypted, provided the other end is willing to co-operate. See our<A -href="politics.html#politics"> history and politics of cryptography</A> - section for discussion of why we think this is needed.</LI> -</UL> -<P>Opportunistic encryption is not (yet?) a standard part of the IPsec - protocols, but an extension we are proposing and demonstrating. For - details of our design, see<A href="#applied"> links</A> below.</P> -<P>Only one current product we know of implements a form of - opportunistic encryption.<A href="web.html#ssmail"> Secure sendmail</A> - will automatically encrypt server-to-server mail transfers whenever - possible.</P> -<H3><A name="types">The need to authenticate gateways</A></H3> -<P>A complication, which applies to any type of connection -- VPN, Road - Warrior or opportunistic -- is that a secure connection cannot be - created magically.<EM> There must be some mechanism which enables the - gateways to reliably identify each other.</EM> Without this, they - cannot sensibly trust each other and cannot create a genuinely secure - link.</P> -<P>Any link they do create without some form of<A href="glossary.html#authentication"> - authentication</A> will be vulnerable to a<A href="glossary.html#middle"> - man-in-the-middle attack</A>. If<A href="glossary.html#alicebob"> Alice - and Bob</A> are the people creating the connection, a villian who can - re-route or intercept the packets can pose as Alice while talking to - Bob and pose as Bob while talking to Alice. Alice and Bob then both - talk to the man in the middle, thinking they are talking to each other, - and the villain gets everything sent on the bogus "secure" connection.</P> -<P>There are two ways to build links securely, both of which exclude the - man-in-the middle:</P> -<UL> -<LI>with<STRONG> manual keying</STRONG>, Alice and Bob share a secret - key (which must be transmitted securely, perhaps in a note or via PGP - or SSH) to encrypt their messages. For FreeS/WAN, such keys are stored - in the<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5)</A> file. Of - course, if an enemy gets the key, all is lost.</LI> -<LI>with<STRONG> automatic keying</STRONG>, the two systems authenticate - each other and negotiate their own secret keys. The keys are - automatically changed periodically.</LI> -</UL> -<P>Automatic keying is much more secure, since if an enemy gets one key - only messages between the previous re-keying and the next are exposed. - It is therefore the usual mode of operation for most IPsec deployment, - and the mode we use in our setup examples. FreeS/WAN does support - manual keying for special circumstanes. See this<A href="adv_config.html#prodman"> - section</A>.</P> -<P>For automatic keying, the two systems must authenticate each other - during the negotiations. There is a choice of methods for this:</P> -<UL> -<LI>a<STRONG> shared secret</STRONG> provides authentication. If Alice - and Bob are the only ones who know a secret and Alice recives a message - which could not have been created without that secret, then Alice can - safely believe the message came from Bob.</LI> -<LI>a<A href="glossary.html#public"> public key</A> can also provide - authentication. If Alice receives a message signed with Bob's private - key (which of course only he should know) and she has a trustworthy - copy of his public key (so that she can verify the signature), then she - can safely believe the message came from Bob.</LI> -</UL> -<P>Public key techniques are much preferable, for reasons discussed<A href="config.html#choose"> - later</A>, and will be used in all our setup examples. FreeS/WAN does - also support auto-keying with shared secret authentication. See this<A href="adv_config.html#prodsecrets"> - section</A>.</P> -<H2><A name="project">The FreeS/WAN project</A></H2> -<P>For complete information on the project, see our web site,<A href="http://liberty.freeswan.org"> - freeswan.org</A>.</P> -<P>In summary, we are implementing the<A href="glossary.html#IPsec"> - IPsec</A> protocols for Linux and extending them to do<A href="glossary.html#carpediem"> - opportunistic encryption</A>.</P> -<H3><A name="goals">Project goals</A></H3> -<P>Our overall goal in FreeS/WAN is to make the Internet more secure and - more private.</P> -<P>Our IPsec implementation supports VPNs and Road Warriors of course. - Those are important applications. Many users will want FreeS/WAN to - build corporate VPNs or to provide secure remote access.</P> -<P>However, our goals in building it go beyond that. We are trying to - help<STRONG> build security into the fabric of the Internet</STRONG> so - that anyone who choses to communicate securely can do so, as easily as - they can do anything else on the net.</P> -<P>More detailed objectives are:</P> -<UL> -<LI>extend IPsec to do<A href="glossary.html#carpediem"> opportunistic - encryption</A> so that -<UL> -<LI>any two systems can secure their communications without a - pre-arranged connection</LI> -<LI><STRONG>secure connections can be the default</STRONG>, falling back - to unencrypted connections only if: -<UL> -<LI><EM>both</EM> the partner is not set up to co-operate on securing - the connection</LI> -<LI><EM>and</EM> your policy allows insecure connections</LI> -</UL> -</LI> -<LI>a significant fraction of all Internet traffic is encrypted</LI> -<LI>wholesale monitoring of the net (<A href="politics.html#intro.poli"> -examples</A>) becomes difficult or impossible</LI> -</UL> -</LI> -<LI>help make IPsec widespread by providing an implementation with no - restrictions: -<UL> -<LI>freely available in source code under the<A href="glossary.html#GPL"> - GNU General Public License</A></LI> -<LI>running on a range of readily available hardware</LI> -<LI>not subject to US or other nations'<A href="politics.html#exlaw"> - export restrictions</A>. -<BR> Note that in order to avoid<EM> even the appearance</EM> of being - subject to those laws, the project cannot accept software contributions - --<EM> not even one-line bug fixes</EM> -- from US residents or - citizens.</LI> -</UL> -</LI> -<LI>provide a high-quality IPsec implementation for Linux -<UL> -<LI>portable to all CPUs Linux supports:<A href="compat.html#CPUs"> - (current list)</A></LI> -<LI>interoperable with other IPsec implementations:<A href="interop.html#interop"> - (current list)</A></LI> -</UL> -</LI> -</UL> -<P>If we can get opportunistic encryption implemented and widely - deployed, then it becomes impossible for even huge well-funded agencies - to monitor the net.</P> -<P>See also our section on<A href="politics.html#politics"> history and - politics</A> of cryptography, which includes our project leader's<A href="politics.html#gilmore"> - rationale</A> for starting the project.</P> -<H3><A name="staff">Project team</A></H3> -<P>Two of the team are from the US and can therefore contribute no code:</P> -<UL> -<LI>John Gilmore: founder and policy-maker (<A href="http://www.toad.com/gnu/"> -home page</A>)</LI> -<LI>Hugh Daniel: project manager, Most Demented Tester, and occasionally - Pointy-Haired Boss</LI> -</UL> -<P>The rest of the team are Canadians, working in Canada. (<A href="politics.html#status"> -Why Canada?</A>)</P> -<UL> -<LI>Hugh Redelmeier:<A href="glossary.html#Pluto"> Pluto daemon</A> - programmer</LI> -<LI>Richard Guy Briggs:<A href="glossary.html#KLIPS"> KLIPS</A> - programmer</LI> -<LI>Michael Richardson: hacker without portfolio</LI> -<LI>Claudia Schmeing: documentation</LI> -<LI>Sam Sgro: technical support via the<A href="mail.html#lists"> - mailing lists</A></LI> -</UL> -<P>The project is funded by civil libertarians who consider our goals - worthwhile. Most of the team are paid for this work.</P> -<P>People outside this core team have made substantial contributions. - See</P> -<UL> -<LI>our<A href="../CREDITS"> CREDITS</A> file</LI> -<LI>the<A href="web.html#patch"> patches and add-ons</A> section of our - web references file</LI> -<LI>lists below of user-written<A href="#howto"> HowTos</A> and<A href="#applied"> - other papers</A></LI> -</UL> -<P>Additional contributions are welcome. See the<A href="faq.html#contrib.faq"> - FAQ</A> for details.</P> -<H2><A name="products">Products containing FreeS/WAN</A></H2> -<P>Unfortunately the<A href="politics.html#exlaw"> export laws</A> of - some countries restrict the distribution of strong cryptography. - FreeS/WAN is therefore not in the standard Linux kernel and not in all - CD or web distributions.</P> -<P>FreeS/WAN is, however, quite widely used. Products we know of that - use it are listed below. We would appreciate hearing, via the<A href="mail.html#lists"> - mailing lists</A>, of any we don't know of.</P> -<H3><A name="distwith">Full Linux distributions</A></H3> -<P>FreeS/WAN is included in various general-purpose Linux distributions, - mostly from countries (shown in brackets) with more sensible laws:</P> -<UL> -<LI><A href="http://www.suse.com/">SuSE Linux</A> (Germany)</LI> -<LI><A href="http://www.conectiva.com">Conectiva</A> (Brazil)</LI> -<LI><A href="http://www.linux-mandrake.com/en/">Mandrake</A> (France)</LI> -<LI><A href="http://www.debian.org">Debian</A></LI> -<LI>the<A href="http://www.pld.org.pl/"> Polish(ed) Linux Distribution</A> - (Poland)</LI> -<LI><A>Best Linux</A> (Finland)</LI> -</UL> -<P>For distributions which do not include FreeS/WAN and are not Redhat - (which we develop and test on), there is additional information in our<A -href="compat.html#otherdist"> compatibility</A> section.</P> -<P>The server edition of<A href="http://www.corel.com"> Corel</A> Linux - (Canada) also had FreeS/WAN, but Corel have dropped that product line.</P> -<H3><A name="kernel_dist">Linux kernel distributions</A></H3> -<UL> -<LI><A href="http://sourceforge.net/projects/wolk/">Working Overloaded - Linux Kernel (WOLK)</A></LI> -</UL> -<H3><A name="office_dist">Office server distributions</A></H3> -<P>FreeS/WAN is also included in several distributions aimed at the - market for turnkey business servers:</P> -<UL> -<LI><A href="http://www.e-smith.com/">e-Smith</A> (Canada), which has - recently been acquired and become the Network Server Solutions group of<A -href="http://www.mitel.com/"> Mitel Networks</A> (Canada)</LI> -<LI><A href="http://www.clarkconnect.org/">ClarkConnect</A> from Point - Clark Networks (Canada)</LI> -<LI><A href="http://www.trustix.net/">Trustix Secure Linux</A> (Norway)</LI> -</UL> -<H3><A name="fw_dist">Firewall distributions</A></H3> -<P>Several distributions intended for firewall and router applications - include FreeS/WAN:</P> -<UL> -<LI>The<A href="http://www.linuxrouter.org/"> Linux Router Project</A> - produces a Linux distribution that will boot from a single floppy. The<A -href="http://leaf.sourceforge.net"> LEAF</A> firewall project provides - several different LRP-based firewall packages. At least one of them, - Charles Steinkuehler's Dachstein, includes FreeS/WAN with X.509 - patches.</LI> -<LI>there are several distributions bootable directly from CD-ROM, - usable on a machine without hard disk. -<UL> -<LI>Dachstein (see above) can be used this way</LI> -<LI><A href="http://www.gibraltar.at/">Gibraltar</A> is based on Debian - GNU/Linux.</LI> -<LI>at time of writing,<A href="www.xiloo.com"> Xiloo</A> is available - only in Chinese. An English version is expected.</LI> -</UL> -</LI> -<LI><A href="http://www.astaro.com/products/index.html">Astaro Security - Linux</A> includes FreeS/WAN. It has some web-based tools for managing - the firewall that include FreeS/WAN configuration management.</LI> -<LI><A href="http://www.linuxwall.de">Linuxwall</A></LI> -<LI><A href="http://www.smoothwall.org/">Smoothwall</A></LI> -<LI><A href="http://www.devil-linux.org/">Devil Linux</A></LI> -<LI>Coyote Linux has a<A href="http://embedded.coyotelinux.com/wolverine/index.php"> - Wolverine</A> firewall/VPN server</LI> -</UL> -<P>There are also several sets of scripts available for managing a - firewall which is also acting as a FreeS/WAN IPsec gateway. See this<A href="firewall.html#rules.pub"> - list</A>.</P> -<H3><A name="turnkey">Firewall and VPN products</A></H3> -<P>Several vendors use FreeS/WAN as the IPsec component of a turnkey - firewall or VPN product.</P> -<P>Software-only products:</P> -<UL> -<LI><A href="http://www.linuxmagic.com/vpn/index.html">Linux Magic</A> - offer a VPN/Firewall product using FreeS/WAN</LI> -<LI>The Software Group's<A href="http://www.wanware.com/sentinet/"> - Sentinet</A> product uses FreeS/WAN</LI> -<LI><A href="http://www.merilus.com">Merilus</A> use FreeS/WAN in their - Gateway Guardian firewall product</LI> -</UL> -<P>Products that include the hardware:</P> -<UL> -<LI>The<A href="http://www.lasat.com"> LASAT SafePipe[tm]</A> series. is - an IPsec box based on an embedded MIPS running Linux with FreeS/WAN and - a web-config front end. This company also host our freeswan.org web - site.</LI> -<LI>Merilus<A href="http://www.merilus.com/products/fc/index.shtml"> - Firecard</A> is a Linux firewall on a PCI card.</LI> -<LI><A href="http://www.kyzo.com/">Kyzo</A> have a "pizza box" product - line with various types of server, all running from flash. One of them - is an IPsec/PPTP VPN server</LI> -<LI><A href="http://www.pfn.com">PFN</A> use FreeS/WAN in some of their - products</LI> -</UL> -<P><A href="www.rebel.com">Rebel.com</A>, makers of the Netwinder Linux - machines (ARM or Crusoe based), had a product that used FreeS/WAN. The - company is in receivership so the future of the Netwinder is at best - unclear.<A href="web.html#patch"> PKIX patches</A> for FreeS/WAN - developed at Rebel are listed in our web links document.</P> -<H2><A name="docs">Information sources</A></H2> -<H3><A name="docformats">This HowTo, in multiple formats</A></H3> -<P>FreeS/WAN documentation up to version 1.5 was available only in HTML. - Now we ship two formats:</P> -<UL> -<LI>as HTML, one file for each doc section plus a global<A href="toc.html"> - Table of Contents</A></LI> -<LI><A href="HowTo.html">one big HTML file</A> for easy searching</LI> -</UL> -<P>and provide a Makefile to generate other formats if required:</P> -<UL> -<LI><A href="HowTo.pdf">PDF</A></LI> -<LI><A href="HowTo.ps">Postscript</A></LI> -<LI><A href="HowTo.txt">ASCII text</A></LI> -</UL> -<P>The Makefile assumes the htmldoc tool is available. You can download - it from<A href="http://www.easysw.com"> Easy Software</A>.</P> -<P>All formats should be available at the following websites:</P> -<UL> -<LI><A href="http://www.freeswan.org/doc.html">FreeS/WAN project</A></LI> -<LI><A href="http://www.linuxdoc.org">Linux Documentation Project</A></LI> -</UL> -<P>The distribution tarball has only the two HTML formats.</P> -<P><STRONG>Note:</STRONG> If you need the latest doc version, for - example to see if anyone has managed to set up interoperation between - FreeS/WAN and whatever, then you should download the current snapshot. - What is on the web is documentation as of the last release. Snapshots - have all changes I've checked in to date.</P> -<H3><A name="rtfm">RTFM (please Read The Fine Manuals)</A></H3> -<P>As with most things on any Unix-like system, most parts of Linux - FreeS/WAN are documented in online manual pages. We provide a list of<A href="/mnt/floppy/manpages.html"> - FreeS/WAN man pages</A>, with links to HTML versions of them.</P> -<P>The man pages describing configuration files are:</P> -<UL> -<LI><A href="/mnt/floppy/manpage.d/ipsec.conf.5.html">ipsec.conf(5)</A></LI> -<LI><A href="/mnt/floppy/manpage.d/ipsec.secrets.5.html"> -ipsec.secrets(5)</A></LI> -</UL> -<P>Man pages for common commands include:</P> -<UL> -<LI><A href="/mnt/floppy/manpage.d/ipsec.8.html">ipsec(8)</A></LI> -<LI><A href="/mnt/floppy/manpage.d/ipsec_pluto.8.html">ipsec_pluto(8)</A> -</LI> -<LI><A href="/mnt/floppy/manpage.d/ipsec_newhostkey.8.html"> -ipsec_newhostkey(8)</A></LI> -<LI><A href="/mnt/floppy/manpage.d/ipsec_auto.8.html">ipsec_auto(8)</A></LI> -</UL> -<P>You can read these either in HTML using the links above or with the<VAR> - man(1)</VAR> command.</P> -<P>In the event of disagreement between this HTML documentation and the - man pages, the man pages are more likely correct since they are written - by the implementers. Please report any such inconsistency on the<A href="mail.html#lists"> - mailing list</A>.</P> -<H3><A name="text">Other documents in the distribution</A></H3> -<P>Text files in the main distribution directory are README, INSTALL, - CREDITS, CHANGES, BUGS and COPYING.</P> -<P>The Libdes encryption library we use has its own documentation. You - can find it in the library directory..</P> -<H3><A name="assumptions">Background material</A></H3> -<P>Throughout this documentation, I write as if the reader had at least - a general familiarity with Linux, with Internet Protocol networking, - and with the basic ideas of system and network security. Of course that - will certainly not be true for all readers, and quite likely not even - for a majority.</P> -<P>However, I must limit amount of detail on these topics in the main - text. For one thing, I don't understand all the details of those topics - myself. Even if I did, trying to explain everything here would produce - extremely long and almost completely unreadable documentation.</P> -<P>If one or more of those areas is unknown territory for you, there are - plenty of other resources you could look at:</P> -<DL> -<DT>Linux</DT> -<DD>the<A href="http://www.linuxdoc.org"> Linux Documentation Project</A> - or a local<A href="http://www.linux.org/groups/"> Linux User Group</A> - and these<A href="web.html#linux.link"> links</A></DD> -<DT>IP networks</DT> -<DD>Rusty Russell's<A href="http://netfilter.samba.org/unreliable-guides/networking-concepts-HOWTO/index.html"> - Networking Concepts HowTo</A> and these<A href="web.html#IP.background"> - links</A></DD> -<DT>Security</DT> -<DD>Schneier's book<A href="biblio.html#secrets"> Secrets and Lies</A> - and these<A href="web.html#crypto.link"> links</A></DD> -</DL> -<P>Also, I do make an effort to provide some background material in - these documents. All the basic ideas behind IPsec and FreeS/WAN are - explained here. Explanations that do not fit in the main text, or that - not everyone will need, are often in the<A href="glossary.html#ourgloss"> - glossary</A>, which is the largest single file in this document set. - There is also a<A href="background.html#background"> background</A> - file containing various explanations too long to fit in glossary - definitions. All files are heavily sprinkled with links to each other - and to the glossary.<STRONG> If some passage makes no sense to you, try - the links</STRONG>.</P> -<P>For other reference material, see the<A href="biblio.html#biblio"> - bibliography</A> and our collection of<A href="web.html#weblinks"> web - links</A>.</P> -<P>Of course, no doubt I get this (and other things) wrong sometimes. - Feedback via the<A href="mail.html#lists"> mailing lists</A> is - welcome.</P> -<H3><A name="archives">Archives of the project mailing list</A></H3> -<P>Until quite recently, there was only one FreeS/WAN mailing list, and - archives of it were:</P> -<UL> -<LI><A href="http://www.sandelman.ottawa.on.ca/linux-ipsec">Canada</A></LI> -<LI><A href="http://www.nexial.com">Holland</A></LI> -</UL> - The two archives use completely different search engines. You might - want to try both. -<P>More recently we have expanded to five lists, each with its own - archive.</P> -<P><A href="mail.html#lists">More information</A> on mailing lists.</P> -<H3><A name="howto">User-written HowTo information</A></H3> -<P>Various user-written HowTo documents are available. The ones covering - FreeS/WAN-to-FreeS/WAN connections are:</P> -<UL> -<LI>Jean-Francois Nadeau's<A href="http://jixen.tripod.com/"> practical - configurations</A> document</LI> -<LI>Jens Zerbst's HowTo on<A href="http://dynipsec.tripod.com/"> Using - FreeS/WAN with dynamic IP addresses</A>.</LI> -<LI>an entry in Kurt Seifried's<A href="http://www.securityportal.com/lskb/kben00000013.html"> - Linux Security Knowledge Base</A>.</LI> -<LI>a section of David Ranch's<A href="http://www.ecst.csuchico.edu/~dranch/LINUX/index-linux.html#trinityos"> - Trinity OS Guide</A></LI> -<LI>a section in David Bander's book<A href="biblio.html#bander"> Linux - Security Toolkit</A></LI> -</UL> -<P>User-wriiten HowTo material may be<STRONG> especially helpful if you - need to interoperate with another IPsec implementation</STRONG>. We - have neither the equipment nor the manpower to test such - configurations. Users seem to be doing an admirable job of filling the - gaps.</P> -<UL> -<LI>list of user-written<A href="interop.html#otherpub"> interoperation - HowTos</A> in our interop document</LI> -</UL> -<P>Check what version of FreeS/WAN user-written documents cover. The - software is under active development and the current version may be - significantly different from what an older document describes.</P> -<H3><A name="applied">Papers on FreeS/WAN</A></H3> -<P>Two design documents show team thinking on new developments:</P> -<UL> -<LI><A href="opportunism.spec">Opportunistic Encryption</A> by technical - lead Henry Spencer and Pluto programmer Hugh Redelemeier</LI> -<LI>discussion of<A href="http://www.sandelman.ottawa.on.ca/SSW/freeswan/klips2req/"> - KLIPS redesign</A></LI> -</UL> -<P>Both documents are works in progress and are frequently revised. For - the latest version, see the<A href="mail.html#lists"> design mailing - list</A>. Comments should go to that list.</P> -<P>There is now an<A href="http://www.ietf.org/internet-drafts/draft-richardson-ipsec-opportunistic-06.txt"> - Internet Draft on Opportunistic Encryption</A> by Michael Richardson, - Hugh Redelmeier and Henry Spencer. This is a first step toward getting - the protocol standardised so there can be multiple implementations of - it. Discussion of it takes place on the<A href="http://www.ietf.org/html.charters/ipsec-charter.html"> - IETF IPsec Working Group</A> mailing list.</P> -<P>A number of papers giving further background on FreeS/WAN, or - exploring its future or its applications, are also available:</P> -<UL> -<LI>Both Henry and Richard gave talks on FreeS/WAN at the 2000<A href="http://www.linuxsymposium.org"> - Ottawa Linux Symposium</A>. -<UL> -<LI>Richard's<A href="http://www.conscoop.ottawa.on.ca/rgb/freeswan/ols2k/"> - slides</A></LI> -<LI>Henry's paper</LI> -<LI>MP3 audio of their talks is available from the<A href="http://www.linuxsymposium.org/"> - conference page</A></LI> -</UL> -</LI> -<LI><CITE>Moat: A Virtual Private Network Appliances and Services - Platform</CITE> is a paper about large-scale (a few 100 links) use of - FreeS/WAN in a production application at AT&T Research. It is available - in Postscript or PDF from co-author Steve Bellovin's<A href="http://www.research.att.com/~smb/papers/index.html"> - papers list page</A>.</LI> -<LI>One of the Moat co-authors, John Denker, has also written -<UL> -<LI>a<A href="http://www.av8n.com/vpn/ipsec+routing.htm"> proposal</A> - for how future versions of FreeS/WAN might interact with routing - protocols</LI> -<LI>a<A href="http://www.av8n.com/vpn/wishlist.htm"> wishlist</A> of - possible new features</LI> -</UL> -</LI> -<LI>Bart Trojanowski's web page has a draft design for<A href="http://www.jukie.net/~bart/linux-ipsec/"> - hardware acceleration</A> of FreeS/WAN</LI> -</UL> -<P>Several of these provoked interesting discussions on the mailing - lists, worth searching for in the<A href="mail.html#archive"> archives</A> -.</P> -<P>There are also several papers in languages other than English, see - our<A href="web.html#otherlang"> web links</A>.</P> -<H3><A name="licensing">License and copyright information</A></H3> -<P>All code and documentation written for this project is distributed - under either the GNU General Public License (<A href="glossary.html#GPL"> -GPL</A>) or the GNU Library General Public License. For details see the - COPYING file in the distribution.</P> -<P>Not all code in the distribution is ours, however. See the CREDITS - file for details. In particular, note that the<A href="glossary.html#LIBDES"> - Libdes</A> library and the version of<A href="glossary.html#MD5"> MD5</A> - that we use each have their own license.</P> -<H2><A name="sites">Distribution sites</A></H2> -<P>FreeS/WAN is available from a number of sites.</P> -<H3><A NAME="1_5_1">Primary site</A></H3> -<P>Our primary site, is at xs4all (Thanks, folks!) in Holland:</P> -<UL> -<LI><A href="http://www.xs4all.nl/~freeswan">HTTP</A></LI> -<LI><A href="ftp://ftp.xs4all.nl/pub/crypto/freeswan">FTP</A></LI> -</UL> -<H3><A name="mirrors">Mirrors</A></H3> -<P>There are also mirror sites all over the world:</P> -<UL> -<LI><A href="http://www.flora.org/freeswan">Eastern Canada</A> (limited - resouces)</LI> -<LI><A href="ftp://ludwig.doculink.com/pub/freeswan/">Eastern Canada</A> - (has older versions too)</LI> -<LI><A href="ftp://ntsc.notBSD.org/pub/crypto/freeswan/">Eastern Canada</A> - (has older versions too)</LI> -<LI><A href="ftp://ftp.kame.net/pub/freeswan/">Japan</A></LI> -<LI><A href="ftp://ftp.futuredynamics.com/freecrypto/FreeSWAN/">Hong - Kong</A></LI> -<LI><A href="ftp://ipsec.dk/pub/freeswan/">Denmark</A></LI> -<LI><A href="ftp://ftp.net.lut.ac.uk/freeswan">the UK</A></LI> -<LI><A href="http://storm.alert.sk/comp/mirrors/freeswan/">Slovak - Republic</A></LI> -<LI><A href="http://the.wiretapped.net/security/vpn-tunnelling/freeswan/"> -Australia</A></LI> -<LI><A href="http://freeswan.technolust.cx/">technolust</A></LI> -<LI><A href="http://freeswan.devguide.de/">Germany</A></LI> -<LI>Ivan Moore's<A href="http://snowcrash.tdyc.com/freeswan/"> site</A></LI> -<LI>the<A href="http://www.cryptoarchive.net/"> Crypto Archive</A> on - the<A href="http://www.securityportal.com/"> Security Portal</A> site</LI> -<LI><A href="http://www.wiretapped.net/">Wiretapped.net</A> in Australia</LI> -</UL> -<P>Thanks to those folks as well.</P> -<H3><A name="munitions">The "munitions" archive of Linux crypto software</A> -</H3> -<P>There is also an archive of Linux crypto software called "munitions", - with its own mirrors in a number of countries. It includes FreeS/WAN, - though not always the latest version. Some of its sites are:</P> -<UL> -<LI><A href="http://munitions.vipul.net/">Germany</A></LI> -<LI><A href="http://munitions.iglu.cjb.net/">Italy</A></LI> -<LI><A href="http://munitions2.xs4all.nl/">Netherlands</A></LI> -</UL> -<P>Any of those will have a list of other "munitions" mirrors. There is - also a CD available.</P> -<H2><A NAME="1_6">Links to other sections</A></H2> -<P>For more detailed background information, see:</P> -<UL> -<LI><A href="politics.html#politics">history and politics</A> of - cryptography</LI> -<LI><A href="ipsec.html#ipsec.detail">IPsec protocols</A></LI> -</UL> -<P>To begin working with FreeS/WAN, go to our<A href="quickstart.html#quick.guide"> - quickstart</A> guide.</P> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="upgrading.html">Next</A> -</BODY> -</HTML> diff --git a/doc/ipsec.html b/doc/ipsec.html deleted file mode 100644 index 4fb27b92b..000000000 --- a/doc/ipsec.html +++ /dev/null @@ -1,1040 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="politics.html">Previous</A> -<A HREF="mail.html">Next</A> -<HR> -<H1><A name="ipsec.detail">The IPsec protocols</A></H1> -<P>This section provides information on the IPsec protocols which - FreeS/WAN implements. For more detail, see the<A href="rfc.html"> RFCs</A> -.</P> -<P>The basic idea of IPsec is to provide security functions,<A href="glossary.html#authentication"> - authentication</A> and<A href="glossary.html#encryption"> encryption</A> -, at the IP (Internet Protocol) level. This requires a higher-level - protocol (IKE) to set things up for the IP-level services (ESP and AH).</P> -<H2><A NAME="27_1">Protocols and phases</A></H2> -<P>Three protocols are used in an IPsec implementation:</P> -<DL> -<DT>ESP, Encapsulating Security Payload</DT> -<DD>Encrypts and/or authenticates data</DD> -<DT>AH, Authentication Header</DT> -<DD>Provides a packet authentication service</DD> -<DT>IKE, Internet Key Exchange</DT> -<DD>Negotiates connection parameters, including keys, for the other two</DD> -</DL> -<P>The term "IPsec" (also written as IPSEC) is slightly ambiguous. In - some contexts, it includes all three of the above but in other contexts - it refers only to AH and ESP.</P> -<P>There is more detail below, but a quick summary of how the whole - thing works is:</P> -<DL> -<DT>Phase one IKE (main mode exchange)</DT> -<DD>sets up a keying channel (ISAKMP SA) between the two gateways</DD> -<DT>Phase two IKE (quick mode exchange)</DT> -<DD>sets up data channels (IPsec SAs)</DD> -<DT>IPsec proper</DT> -<DD>exchanges data using AH or ESP</DD> -</DL> -<P>Both phases of IKE are repeated periodically to automate re-keying.</P> -<H2><A name="others">Applying IPsec</A></H2> -<P>Authentication and encryption functions for network data can, of - course, be provided at other levels. Many security protocols work at - levels above IP.</P> -<UL> -<LI><A href="glossary.html#PGP">PGP</A> encrypts and authenticates mail - messages</LI> -<LI><A href="glossary.html#SSH">SSH</A> authenticates remote logins and - then encrypts the session</LI> -<LI><A href="glossary.html#SSL">SSL</A> or<A href="glossary.html#TLS"> - TLS</A> provides security at the sockets layer, e.g. for secure web - browsing</LI> -</UL> -<P>and so on. Other techniques work at levels below IP. For example, - data on a communications circuit or an entire network can be encrypted - by specialised hardware. This is common practice in high-security - applications.</P> -<H3><A name="advantages">Advantages of IPsec</A></H3> -<P>There are, however, advantages to doing it at the IP level instead - of, or as well as, at other levels.</P> -<P>IPsec is the<STRONG> most general way to provide these services for - the Internet</STRONG>.</P> -<UL> -<LI>Higher-level services protect a<EM> single protocol</EM>; for - example PGP protects mail.</LI> -<LI>Lower level services protect a<EM> single medium</EM>; for example a - pair of encryption boxes on the ends of a line make wiretaps on that - line useless unless the attacker is capable of breaking the encryption.</LI> -</UL> -<P>IPsec, however, can protect<EM> any protocol</EM> running above IP - and<EM> any medium</EM> which IP runs over. More to the point, it can - protect a mixture of application protocols running over a complex - combination of media. This is the normal situation for Internet - communication; IPsec is the only general solution.</P> -<P>IPsec can also provide some security services "in the background", - with<STRONG> no visible impact on users</STRONG>. To use<A href="glossary.html#PGP"> - PGP</A> encryption and signatures on mail, for example, the user must - at least:</P> -<UL> -<LI>remember his or her passphrase,</LI> -<LI>keep it secure</LI> -<LI>follow procedures to validate correspondents' keys</LI> -</UL> -<P>These systems can be designed so that the burden on users is not - onerous, but any system will place some requirements on users. No such - system can hope to be secure if users are sloppy about meeting those - requirements. The author has seen username and password stuck on - terminals with post-it notes in an allegedly secure environment, for - example.</P> -<H3><A name="limitations">Limitations of IPsec</A></H3> -<P>IPsec is designed to secure IP links between machines. It does that - well, but it is important to remember that there are many things it - does not do. Some of the important limitations are:</P> -<DL> -<DT><A name="depends">IPsec cannot be secure if your system isn't</A></DT> -<DD>System security on IPsec gateway machines is an essential - requirement if IPsec is to function as designed. No system can be - trusted if the underlying machine has been subverted. See books on Unix - security such as<A href="biblio.html#practical"> Garfinkel and Spafford</A> - or our web references for<A href="web.html#linsec"> Linux security</A> - or more general<A href="web.html#compsec"> computer security</A>. -<P>Of course, there is another side to this. IPsec can be a powerful - tool for improving system and network security. For example, requiring - packet authentication makes various spoofing attacks harder and IPsec - tunnels can be extremely useful for secure remote administration of - various things.</P> -</DD> -<DT><A name="not-end-to-end">IPsec is not end-to-end</A></DT> -<DD>IPsec cannot provide the same end-to-end security as systems working - at higher levels. IPsec encrypts an IP connection between two machines, - which is quite a different thing than encrypting messages between users - or between applications. -<P>For example, if you need mail encrypted from the sender's desktop to - the recipient's desktop and decryptable only by the recipient, use<A href="glossary.html#PGP"> - PGP</A> or another such system. IPsec can encrypt any or all of the - links involved -- between the two mail servers, or between either - server and its clients. It could even be used to secure a direct IP - link from the sender's desktop machine to the recipient's, cutting out - any sort of network snoop. What it cannot ensure is end-to-end - user-to-user security. If only IPsec is used to secure mail, then - anyone with appropriate privileges on any machine where that mail is - stored (at either end or on any store-and-forward servers in the path) - can read it.</P> -<P>In another common setup, IPsec encrypts packets at a security gateway - machine as they leave the sender's site and decrypts them on arrival at - the gateway to the recipient's site. This does provide a useful - security service -- only encrypted data is passed over the Internet -- - but it does not even come close to providing an end-to-end service. In - particular, anyone with appropriate privileges on either site's LAN can - intercept the message in unencrypted form.</P> -</DD> -<DT><A name="notpanacea">IPsec cannot do everything</A></DT> -<DD>IPsec also cannot provide all the functions of systems working at - higher levels of the protocol stack. If you need a document - electronically signed by a particular person, then you need his or her<A -href="glossary.html#signature"> digital signature</A> and a<A href="glossary.html#public"> - public key cryptosystem</A> to verify it with. -<P>Note, however, that IPsec authentication of the underlying - communication can make various attacks on higher-level protocols more - difficult. In particular, authentication prevents<A href="glossary.html#middle"> - man-in-the-middle attacks</A>.</P> -</DD> -<DT><A name="no_user">IPsec authenticates machines, not users</A></DT> -<DD>IPsec uses strong authentication mechanisms to control which - messages go to which machines, but it does not have the concept of user - ID, which is vital to many other security mechansims and policies. This - means some care must be taken in fitting the various security - mechansims on a network together. For example, if you need to control - which users access your database server, you need some non-IPsec - mechansim for that. IPsec can control which machines connect to the - server, and can ensure that data transfer to those machines is done - securely, but that is all. Either the machines themselves must control - user access or there must be some form of user authentication to the - database, independent of IPsec.</DD> -<DT><A name="DoS">IPsec does not stop denial of service attacks</A></DT> -<DD><A href="glossary.html#DOS">Denial of service</A> attacks aim at - causing a system to crash, overload, or become confused so that - legitimate users cannot get whatever services the system is supposed to - provide. These are quite different from attacks in which the attacker - seeks either to use the service himself or to subvert the service into - delivering incorrect results. -<P>IPsec shifts the ground for DoS attacks; the attacks possible against - systems using IPsec are different than those that might be used against - other systems. It does not, however, eliminate the possibility of such - attacks.</P> -</DD> -<DT><A name="traffic">IPsec does not stop traffic analysis</A></DT> -<DD><A href="glossary.html#traffic">Traffic analysis</A> is the attempt - to derive intelligence from messages without regard for their contents. - In the case of IPsec, it would mean analysis based on things visible in - the unencrypted headers of encrypted packets -- source and destination - gateway addresses, packet size, et cetera. Given the resources to - acquire such data and some skill in analysing it (both of which any - national intelligence agency should have), this can be a very powerful - technique. -<P>IPsec is not designed to defend against this. Partial defenses are - certainly possible, and some are<A href="#traffic.resist"> described - below</A>, but it is not clear that any complete defense can be - provided.</P> -</DD> -</DL> -<H3><A name="uses">IPsec is a general mechanism for securing IP</A></H3> -<P>While IPsec does not provide all functions of a mail encryption - package, it can encrypt your mail. In particular, it can ensure that - all mail passing between a pair or a group of sites is encrypted. An - attacker looking only at external traffic, without access to anything - on or behind the IPsec gateway, cannot read your mail. He or she is - stymied by IPsec just as he or she would be by<A href="glossary.html#PGP"> - PGP</A>.</P> -<P>The advantage is that IPsec can provide the same protection for<STRONG> - anything transmitted over IP</STRONG>. In a corporate network example, - PGP lets the branch offices exchange secure mail with head office. SSL - and SSH allow them to securely view web pages, connect as terminals to - machines, and so on. IPsec can support all those applications, plus - database queries, file sharing (NFS or Windows), other protocols - encapsulated in IP (Netware, Appletalk, ...), phone-over-IP, - video-over-IP, ... anything-over-IP. The only limitation is that IP - Multicast is not yet supported, though there are Internet Draft - documents for that.</P> -<P>IPsec creates<STRONG> secure tunnels through untrusted networks</STRONG> -. Sites connected by these tunnels form VPNs,<A href="glossary.html#VPN"> - Virtual Private Networks</A>.</P> -<P>IPsec gateways can be installed wherever they are required.</P> -<UL> -<LI>One organisation might choose to install IPsec only on firewalls - between their LANs and the Internet. This would allow them to create a - VPN linking several offices. It would provide protection against anyone - outside their sites.</LI> -<LI>Another might install IPsec on departmental servers so everything on - the corporate backbone net was encrypted. This would protect messages - on that net from everyone except the sending and receiving department.</LI> -<LI>Another might be less concerned with information secrecy and more - with controlling access to certain resources. They might use IPsec - packet authentication as part of an access control mechanism, with or - without also using the IPsec encryption service.</LI> -<LI>It is even possible (assuming adequate processing power and an IPsec - implementation in each node) to make every machine its own IPsec - gateway so that everything on a LAN is encrypted. This protects - information from everyone outside the sending and receiving machine.</LI> -<LI>These techniques can be combined in various ways. One might, for - example, require authentication everywhere on a network while using - encryption only for a few links.</LI> -</UL> -<P>Which of these, or of the many other possible variants, to use is up - to you.<STRONG> IPsec provides mechanisms; you provide the policy</STRONG> -.</P> -<P><STRONG>No end user action is required</STRONG> for IPsec security to - be used; they don't even have to know about it. The site - administrators, of course, do have to know about it and to put some - effort into making it work. Poor administration can compromise IPsec as - badly as the post-it notes mentioned above. It seems reasonable, - though, for organisations to hope their system administrators are - generally both more security-conscious than end users and more able to - follow computer security procedures. If not, at least there are fewer - of them to educate or replace.</P> -<P>IPsec can be, and often should be, used with along with security - protocols at other levels. If two sites communicate with each other via - the Internet, then IPsec is the obvious way to protect that - communication. If two others have a direct link between them, either - link encryption or IPsec would make sense. Choose one or use both. - Whatever you use at and below the IP level, use other things as - required above that level. Whatever you use above the IP level, - consider what can be done with IPsec to make attacks on the higher - levels harder. For example,<A href="glossary.html#middle"> - man-in-the-middle attacks</A> on various protocols become difficult if - authentication at packet level is in use on the potential victims' - communication channel.</P> -<H3><A name="authonly">Using authentication without encryption</A></H3> -<P>Where appropriate, IPsec can provide authentication without - encryption. One might do this, for example:</P> -<UL> -<LI>where the data is public but one wants to be sure of getting the - right data, for example on some web sites</LI> -<LI>where encryption is judged unnecessary, for example on some company - or department LANs</LI> -<LI>where strong encryption is provided at link level, below IP</LI> -<LI>where strong encryption is provided in other protocols, above IP -<BR> Note that IPsec authentication may make some attacks on those - protocols harder.</LI> -</UL> -<P>Authentication has lower overheads than encryption.</P> -<P>The protocols provide four ways to build such connections, using - either an AH-only connection or ESP using null encryption, and in - either manually or automatically keyed mode. FreeS/WAN supports only - one of these, manually keyed AH-only connections, and<STRONG> we do not - recommend using that</STRONG>. Our reasons are discussed under<A href="#traffic.resist"> - Resisting traffic analysis</A> a few sections further along.</P> -<H3><A name="encnoauth">Encryption without authentication is dangerous</A> -</H3> -<P>Originally, the IPsec encryption protocol<A href="glossary.html#ESP"> - ESP</A> didn't do integrity checking. It only did encryption. Steve - Bellovin found many ways to attack ESP used without authentication. See - his paper<A href="http://www.research.att.com/~smb/papers/badesp.ps"> - Problem areas for the IP Security Protocols</A>. To make a secure - connection, you had to add an<A href="glossary.html#AH"> AH</A> - Authentication Header as well as ESP. Rather than incur the overhead of - several layers (and rather than provide an ESP layer that didn't - actually protect the traffic), the IPsec working group built integrity - and replay checking directly into ESP.</P> -<P>Today, typical usage is one of:</P> -<UL> -<LI>ESP for encryption and authentication</LI> -<LI>AH for authentication alone</LI> -</UL> -<P>Other variants are allowed by the standard, but not much used:</P> -<DL> -<DT>ESP encryption without authentication</DT> -<DD><STRONG>Bellovin has demonstrated fatal flaws in this. Do not use.</STRONG> -</DD> -<DT>ESP encryption with AH authentication</DT> -<DD>This has higher overheads than using the authentication in ESP, and - no obvious benefit in most cases. The exception might be a network - where AH authentication was widely or universally used. If you're going - to do AH to conform with network policy, why authenticate again in the - ESP layer?</DD> -<DT>Authenticate twice, with AH and with ESP</DT> -<DD>Why? Of course, some folk consider "belt and suspenders" the - sensible approach to security. If you're among them, you might use both - protocols here. You might also use both to satisfy different parts of a - security policy. For example, an organisation might require AH - authentication everywhere but two users within the organisation might - use ESP as well.</DD> -<DT>ESP authentication without encryption</DT> -<DD>The standard allows this, calling it "null encryption". FreeS/WAN - does not support it. We recommend that you use AH instead if - authentication is all you require. AH authenticates parts of the IP - header, which ESP-null does not do.</DD> -</DL> -<P>Some of these variants cannot be used with FreeS/WAN because we do - not support ESP-null and do not support automatic keying of AH-only - connections.</P> -<P>There are fairly frequent suggestions that AH be dropped entirely - from the IPsec specifications since ESP and null encryption can handle - that situation. It is not clear whether this will occur. My guess is - that it is unlikely.</P> -<H3><A name="multilayer">Multiple layers of IPsec processing are - possible</A></H3> -<P>The above describes combinations possible on a single IPsec - connection. In a complex network you may have several layers of IPsec - in play, with any of the above combinations at each layer.</P> -<P>For example, a connection from a desktop machine to a database server - might require AH authentication. Working with other host, network and - database security measures, AH might be just the thing for access - control. You might decide not to use ESP encryption on such packets, - since it uses resources and might complicate network debugging. Within - the site where the server is, then, only AH would be used on those - packets.</P> -<P>Users at another office, however, might have their whole connection - (AH headers and all) passing over an IPsec tunnel connecting their - office to the one with the database server. Such a tunnel should use - ESP encryption and authentication. You need authentication in this - layer because without authentication the encryption is vulnerable and - the gateway cannot verify the AH authentication. The AH is between - client and database server; the gateways aren't party to it.</P> -<P>In this situation, some packets would get multiple layers of IPsec - applied to them, AH on an end-to-end client-to-server basis and ESP - from one office's security gateway to the other.</P> -<H3><A name="traffic.resist">Resisting traffic analysis</A></H3> -<P><A href="glossary.html#traffic">Traffic analysis</A> is the attempt - to derive useful intelligence from encrypted traffic without breaking - the encryption.</P> -<P>Is your CEO exchanging email with a venture capital firm? With - bankruptcy trustees? With an executive recruiting agency? With the - holder of some important patents? If an eavesdropper learns about any - of those, then he has interesting intelligence on your company, whether - or not he can read the messages themselves.</P> -<P>Even just knowing that there is network traffic between two sites may - tell an analyst something useful, especially when combined with - whatever other information he or she may have. For example, if you know - Company A is having cashflow problems and Company B is looking for - aquisitions, then knowing that packets are passing between the two is - interesting. It is more interesting if you can tell it is email, and - perhaps yet more if you know the sender and recipient.</P> -<P>Except in the simplest cases, traffic analysis is hard to do well. It - requires both considerable resources and considerable analytic skill. - However, intelligence agencies of various nations have been doing it - for centuries and many of them are likely quite good at it by now. - Various commercial organisations, especially those working on "targeted - marketing" may also be quite good at analysing certain types of - traffic.</P> -<P>In general, defending against traffic analysis is also difficult. - Inventing a really good defense could get you a PhD and some - interesting job offers.</P> -<P>IPsec is not designed to stop traffic analysis and we know of no - plausible method of extending it to do so. That said, there are ways to - make traffic analysis harder. This section describes them.</P> -<H4><A name="extra">Using "unnecessary" encryption</A></H4> -<P>One might choose to use encryption even where it appears unnecessary - in order to make analysis more difficult. Consider two offices which - pass a small volume of business data between them using IPsec and also - transfer large volumes of Usenet news. At first glance, it would seem - silly to encrypt the newsfeed, except possibly for any newsgroups that - are internal to the company. Why encrypt data that is all publicly - available from many sites?</P> -<P>However, if we encrypt a lot of news and send it down the same - connection as our business data, we make<A href="glossary.html#traffic"> - traffic analysis</A> much harder. A snoop cannot now make inferences - based on patterns in the volume, direction, sizes, sender, destination, - or timing of our business messages. Those messages are hidden in a mass - of news messages encapsulated in the same way.</P> -<P>If we're going to do this we need to ensure that keys change often - enough to remain secure even with high volumes and with the adversary - able to get plaintext of much of the data. We also need to look at - other attacks this might open up. For example, can the adversary use a - chosen plaintext attack, deliberately posting news articles which, when - we receive and encrypt them, will help break our encryption? Or can he - block our business data transmission by flooding us with silly news - articles? Or ...</P> -<P>Also, note that this does not provide complete protection against - traffic analysis. A clever adversary might still deduce useful - intelligence from statistical analysis (perhaps comparing the input - newsfeed to encrypted output, or comparing the streams we send to - different branch offices), or by looking for small packets which might - indicate establishment of TCP connections, or ...</P> -<P>As a general rule, though, to improve resistance to traffic analysis, - you should<STRONG> encrypt as much traffic as possible, not just as - much as seems necessary.</STRONG></P> -<H4><A name="multi-encrypt">Using multiple encryption</A></H4> -<P>This also applies to using multiple layers of encryption. If you have - an IPsec tunnel between two branch offices, it might appear silly to - send<A href="glossary.html#PGP"> PGP</A>-encrypted email through that - tunnel. However, if you suspect someone is snooping your traffic, then - it does make sense:</P> -<UL> -<LI>it protects the mail headers; they cannot even see who is mailing - who</LI> -<LI>it protects against user bungles or software malfunctions that - accidentally send messages in the clear</LI> -<LI>it makes any attack on the mail encryption much harder; they have to - break IPsec or break into your network before they can start on the - mail encryption</LI> -</UL> -<P>Similar arguments apply for<A href="glossary.html#SSL"> SSL</A> --encrypted web traffic or<A href="glossary.html#SSH"> SSH</A>-encrypted - remote login sessions, even for end-to-end IPsec tunnels between - systems in the two offices.</P> -<H4><A name="fewer">Using fewer tunnels</A></H4> -<P>It may also help to use fewer tunnels. For example, if all you - actually need encrypted is connections between:</P> -<UL> -<LI>mail servers at branch and head offices</LI> -<LI>a few branch office users and the head office database server</LI> -</UL> -<P>You might build one tunnel per mail server and one per remote - database user, restricting traffic to those applications. This gives - the traffic analyst some information, however. He or she can - distinguish the tunnels by looking at information in the ESP header - and, given that distinction and the patterns of tunnel usage, might be - able to figure out something useful. Perhaps not, but why take the - risk?</P> -<P>We suggest instead that you build one tunnel per branch office, - encrypting everything passing from head office to branches. This has a - number of advantages:</P> -<UL> -<LI>it is easier to build and administer</LI> -<LI>it resists traffic analysis somewhat better</LI> -<LI>it provides security for whatever you forgot. For example, if some - user at a remote office browses proprietary company data on some head - office web page (that the security people may not even know about!), - then that data is encrypted before it reaches the Internet.</LI> -</UL> -<P>Of course you might also want to add additional tunnels. For example, - if some of the database data is confidential and should not be exposed - even within the company, then you need protection from the user's - desktop to the database server. We suggest you do that in whatever way - seems appropriate -- IPsec, SSH or SSL might fit -- but, whatever you - choose, pass it between locations via a gateway-to-gateway IPsec tunnel - to provide some resistance to traffic analysis.</P> -<H2><A name="primitives">Cryptographic components</A></H2> -<P>IPsec combines a number of cryptographic techniques, all of them - well-known and well-analyzed. The overall design approach was - conservative; no new or poorly-understood components were included.</P> -<P>This section gives a brief overview of each technique. It is intended - only as an introduction. There is more information, and links to - related topics, in our<A href="glossary.html"> glossary</A>. See also - our<A href="biblio.html"> bibliography</A> and cryptography<A href="web.html#crypto.link"> - web links</A>.</P> -<H3><A name="block.cipher">Block ciphers</A></H3> -<P>The<A href="glossary.html#encryption"> encryption</A> in the<A href="glossary.html#ESP"> - ESP</A> encapsulation protocol is done with a<A href="glossary.html#block"> - block cipher</A>.</P> -<P>We do not implement<A href="glossary.html#DES"> single DES</A>. It is<A -href="politics.html#desnotsecure"> insecure</A>. Our default, and - currently only, block cipher is<A href="glossary.html#3DES"> triple DES</A> -.</P> -<P>The<A href="glossary.html#rijndael"> Rijndael</A> block cipher has - won the<A href="glossary.html#AES"> AES</A> competition to choose a - relacement for DES. It will almost certainly be added to FreeS/WAN and - to other IPsec implementations.<A href="web.html#patch"> Patches</A> - are already available.</P> -<H3><A name="hash.ipsec">Hash functions</A></H3> -<H4><A name="hmac.ipsec">The HMAC construct</A></H4> -<P>IPsec packet authentication is done with the<A href="glossary.html#HMAC"> - HMAC</A> construct. This is not just a hash of the packet data, but a - more complex operation which uses both a hashing algorithm and a key. - It therefore does more than a simple hash would. A simple hash would - only tell you that the packet data was not changed in transit, or that - whoever changed it also regenerated the hash. An HMAC also tells you - that the sender knew the HMAC key.</P> -<P>For IPsec HMAC, the output of the hash algorithm is truncated to 96 - bits. This saves some space in the packets. More important, it prevents - an attacker from seeing all the hash output bits and perhaps creating - some sort of attack based on that knowledge.</P> -<H4>Choice of hash algorithm</H4> -<P>The IPsec RFCs require two hash algorithms --<A href="glossary.html#MD5"> - MD5</A> and<A href="glossary.html#SHA"> SHA-1</A> -- both of which - FreeS/WAN implements.</P> -<P>Various other algorithms -- such as RIPEMD and Tiger -- are listed in - the RFCs as optional. None of these are in the FreeS/WAN distribution, - or are likely to be added, although user<A href="web.html#patch"> - patches</A> exist for several of them.</P> -<P>Additional hash algorithms --<A href="glossary.html#SHA-256"> - SHA-256, SHA-384 and SHA-512</A> -- may be required to give hash - strength matching the strength of<A href="glossary.html#AES"> AES</A>. - These are likely to be added to FreeS/WAN along with AES.</P> -<H3><A name="DH.keying">Diffie-Hellman key agreement</A></H3> -<P>The<A href="glossary.html#DH"> Diffie-Hellman</A> key agreement - protocol allows two parties (A and B or<A href="glossary.html#alicebob"> - Alice and Bob</A>) to agree on a key in such a way that an eavesdropper - who intercepts the entire conversation cannot learn the key.</P> -<P>The protocol is based on the<A href="glossary.html#dlog"> discrete - logarithm</A> problem and is therefore thought to be secure. - Mathematicians have been working on that problem for years and seem no - closer to a solution, though there is no proof that an efficient - solution is impossible.</P> -<H3><A name="RSA.auth">RSA authentication</A></H3> -<P>The<A href="glossary.html#RSA"> RSA</A> algorithm (named for its - inventors -- Rivest, Shamir and Adleman) is a very widely used<A href="glossary.html#"> - public key</A> cryptographic technique. It is used in IPsec as one - method of authenticating gateways for Diffie-Hellman key negotiation.</P> -<H2><A name="structure">Structure of IPsec</A></H2> -<P>There are three protocols used in an IPsec implementation:</P> -<DL> -<DT>ESP, Encapsulating Security Payload</DT> -<DD>Encrypts and/or authenticates data</DD> -<DT>AH, Authentication Header</DT> -<DD>Provides a packet authentication service</DD> -<DT>IKE, Internet Key Exchange</DT> -<DD>Negotiates connection parameters, including keys, for the other two</DD> -</DL> -<P>The term "IPsec" is slightly ambiguous. In some contexts, it includes - all three of the above but in other contexts it refers only to AH and - ESP.</P> -<H3><A name="IKE.ipsec">IKE (Internet Key Exchange)</A></H3> -<P>The IKE protocol sets up IPsec (ESP or AH) connections after - negotiating appropriate parameters (algorithms to be used, keys, - connection lifetimes) for them. This is done by exchanging packets on - UDP port 500 between the two gateways.</P> -<P>IKE (RFC 2409) was the outcome of a long, complex process in which - quite a number of protocols were proposed and debated. Oversimplifying - mildly, IKE combines:</P> -<DL> -<DT>ISAKMP (RFC 2408)</DT> -<DD>The<STRONG> I</STRONG>nternet<STRONG> S</STRONG>ecurity<STRONG> A</STRONG> -ssociation and<STRONG> K</STRONG>ey<STRONG> M</STRONG>anagement<STRONG> - P</STRONG>rotocol manages negotiation of connections and defines<A href="glossary.html#SA"> - SA</A>s (Security Associations) as a means of describing connection - properties.</DD> -<DT>IPsec DOI for ISAKMP (RFC 2407)</DT> -<DD>A<STRONG> D</STRONG>omain<STRONG> O</STRONG>f<STRONG> I</STRONG> -nterpretation fills in the details necessary to turn the rather abstract - ISAKMP protocol into a more tightly specified protocol, so it becomes - applicable in a particular domain.</DD> -<DT>Oakley key determination protocol (RFC 2412)</DT> -<DD>Oakley creates keys using the<A href="glossary.html#DH"> - Diffie-Hellman</A> key agreement protocol.</DD> -</DL> -<P>For all the details, you would need to read the four<A href="rfc.html"> - RFCs</A> just mentioned (over 200 pages) and a number of others. We - give a summary below, but it is far from complete.</P> -<H4><A name="phases">Phases of IKE</A></H4> -<P>IKE negotiations have two phases.</P> -<DL> -<DT>Phase one</DT> -<DD>The two gateways negotiate and set up a two-way ISAKMP SA which they - can then use to handle phase two negotiations. One such SA between a - pair of gateways can handle negotiations for multiple tunnels.</DD> -<DT>Phase two</DT> -<DD>Using the ISAKMP SA, the gateways negotiate IPsec (ESP and/or AH) - SAs as required. IPsec SAs are unidirectional (a different key is used - in each direction) and are always negotiated in pairs to handle two-way - traffic. There may be more than one pair defined between two gateways.</DD> -</DL> -<P>Both of these phases use the UDP protocol and port 500 for their - negotiations.</P> -<P>After both IKE phases are complete, you have IPsec SAs to carry your - encrypted data. These use the ESP or AH protocols. These protocols do - not have ports. Ports apply only to UDP or TCP.</P> -<P>The IKE protocol is designed to be extremely flexible. Among the - things that can be negotiated (separately for each SA) are:</P> -<UL> -<LI>SA lifetime before rekeying</LI> -<LI>encryption algorithm used. We currently support only<A href="glossary.html#3DES"> - triple DES</A>. Single DES is<A href="politics.html#desnotsecure"> - insecure</A>. The RFCs say you MUST do DES, SHOULD do 3DES and MAY do - various others. We do not do any of the others.</LI> -<LI>authentication algorithms. We support<A href="glossary.html#MD5"> - MD5</A> and<A href="glossary.html#SHA"> SHA</A>. These are the two the - RFCs require.</LI> -<LI>choice of group for<A href="glossary.html#DH"> Diffie-Hellman</A> - key agreement. We currently support Groups 2 and 5 (which are defined - modulo primes of various lengths) and do not support Group 1 (defined - modulo a shorter prime, and therefore cryptographically weak) or groups - 3 and 4 (defined using elliptic curves). The RFCs require only Group 1.</LI> -</UL> -<P>The protocol also allows implementations to add their own encryption - algorithms, authentication algorithms or Diffie-Hellman groups. We do - not support any such extensions, but there are some<A href="web.html#patch"> - patches</A> that do.</P> -<P>There are a number of complications:</P> -<UL> -<LI>The gateways must be able to authenticate each other's identities - before they can create a secure connection. This host authentication is - part of phase one negotiations, and is a required prerequisite for - packet authentication used later. Host authentication can be done in a - variety of ways. Those supported by FreeS/WAN are discussed in our<A href="adv_config.html#auto-auth"> - advanced configuration</A> document.</LI> -<LI>Phase one can be done in two ways. -<UL> -<LI>Main Mode is required by the RFCs and supported in FreeS/WAN. It - uses a 6-packet exzchange.</LI> -<LI>Aggressive Mode is somewhat faster (only 3 packets) but reveals more - to an eavesdropper. This is optional in the RFCs, not currently - supported by FreeS/WAN, and not likely to be.</LI> -</UL> -</LI> -<LI>A new group exchange may take place after phase one but before phase - two, defining an additional group for use in the<A href="glossary.html#DH"> - Diffie-Hellman</A> key agreement part of phase two. FreeS/WAN does not - currently support this.</LI> -<LI>Phase two always uses Quick Mode, but there are two variants of - that: -<UL> -<LI>One variant provides<A href="glossary.html#PFS"> Perfect Forward - Secrecy (PFS)</A>. An attacker that obtains your long-term host - authentication key does not immediately get any of your short-term - packet encryption of packet authentication keys. He must conduct - another successful attack each time you rekey to get the short-term - keys. Having some short-term keys does not help him learn others. In - particular, breaking your system today does not let him read messages - he archived yestarday, assuming you've changed short-term keys in the - meanwhile. We enable PFS as the default.</LI> -<LI>The other variant disables PFS and is therefore slightly faster. We - do not recommend this since it is less secure, but FreeS/WAN does - support it. You can enable it with a<VAR> pfs=no</VAR> statement in<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A>.</LI> -<LI>The protocol provides no way to negotiate which variant will be - used. If one gateway is set for PFS and the other is not, the - negotiation fails. This has proved a fairly common source of - interoperation problems.</LI> -</UL> -</LI> -<LI>Several types of notification message may be sent by either side - during either phase, or later. FreeS/WAN does not currently support - these, but they are a likely addition in future releases.</LI> -<LI>There is a commit flag which may optionally be set on some messages. - The<A href="http://www.lounge.org/ike_doi_errata.html"> errata</A> page - for the RFCs includes two changes related to this, one to clarify the - description of its use and one to block a<A href="glossary.html#DOS"> - denial of service</A> attack which uses it. We currently do not - implement this feature.</LI> -</UL> -<P>These complications can of course lead to problems, particularly when - two different implementations attempt to interoperate. For example, we - have seen problems such as:</P> -<UL> -<LI>Some implementations (often products crippled by<A href="politics.html#exlaw"> - export laws</A>) have the insecure DES algorithm as their only - supported encryption method. Other parts of our documentation discuss - the<A href="politics.html#desnotsecure"> reasons we do not implement - single DES</A>, and<A href="interop.html#noDES"> how to cope with - crippled products</A>.</LI> -<LI>Windows 2000 IPsec tries to negotiate using Aggressive Mode, which - we don't support. Later on, it uses the commit bit, which we also don't - support.</LI> -<LI>Various implementations disable PFS by default, and therefore will - not talk to FreeS/WAN until you either turn on PFS on their end or turn - it off in FreeS/WAN with a<VAR> pfs=no</VAR> entry in the connection - description.</LI> -<LI>FreeS/WAN's interaction with PGPnet is complicated by their use of - notification messages we do not yet support.</LI> -</UL> -<P>Despite this, we do interoperate successfully with many - implementations, including both Windows 2000 and PGPnet. Details are in - our<A href="interop.html"> interoperability</A> document.</P> -<H4><A name="sequence">Sequence of messages in IKE</A></H4> -<P>Each phase (see<A href="#phases"> previous section</A>)of IKE - involves a series of messages. In Pluto error messages, these are - abbreviated using:</P> -<DL> -<DT>M</DT> -<DD><STRONG>M</STRONG>ain mode, settting up the keying channel (ISAKMP - SA)</DD> -<DT>Q</DT> -<DD><STRONG>Q</STRONG>uick mode, setting up the data channel (IPsec SA)</DD> -<DT>I</DT> -<DD><STRONG>I</STRONG>nitiator, the machine that starts the negotiation</DD> -<DT>R</DT> -<DD><STRONG>R</STRONG>esponder</DD> -</DL> -<P>For example, the six messages of a main mode negotiation, in - sequence, are labelled:</P> -<PRE> MI1 ----------> - <---------- MR1 - MI2 ----------> - <---------- MR2 - MI3 ----------> - <---------- MR3</PRE> -<H4><A name="struct.exchange">Structure of IKE messages</A></H4> -<P>Here is our Pluto developer explaining some of this on the mailing - list:</P> -<PRE>When one IKE system (for example, Pluto) is negotiating with another -to create an SA, the Initiator proposes a bunch of choices and the -Responder replies with one that it has selected. - -The structure of the choices is fairly complicated. An SA payload -contains a list of lists of "Proposals". The outer list is a set of -choices: the selection must be from one element of this list. - -Each of these elements is a list of Proposals. A selection must be -made from each of the elements of the inner list. In other words, -*all* of them apply (that is how, for example, both AH and ESP can -apply at once). - -Within each of these Proposals is a list of Transforms. For each -Proposal selected, one Transform must be selected (in other words, -each Proposal provides a choice of Transforms). - -Each Transform is made up of a list of Attributes describing, well, -attributes. Such as lifetime of the SA. Such as algorithm to be -used. All the Attributes apply to a Transform. - -You will have noticed a pattern here: layers alternate between being -disjunctions ("or") and conjunctions ("and"). - -For Phase 1 / Main Mode (negotiating an ISAKMP SA), this structure is -cut back. There must be exactly one Proposal. So this degenerates to -a list of Transforms, one of which must be chosen.</PRE> -<H3><A name="services">IPsec Services, AH and ESP</A></H3> -<P>IPsec offers two services,<A href="glossary.html#authentication"> - authentication</A> and<A href="glossary.html#encryption"> encryption</A> -. These can be used separately but are often used together.</P> -<DL> -<DT>Authentication</DT> -<DD>Packet-level authentication allows you to be confident that a packet - came from a particular machine and that its contents were not altered - en route to you. No attempt is made to conceal or protect the contents, - only to assure their integrity. Packet authentication can be provided - separately using an<A href="glossary.html#AH"> Authentication Header</A> -, described just below, or it can be included as part of the<A href="glossary.html#ESP"> - ESP</A> (Encapsulated Security Payload) service, described in the - following section. That service offers encryption as well as - authentication. In either case, the<A href="glossary.html#HMAC"> HMAC</A> - construct is used as the authentication mechanism. -<P>There is a separate authentication operation at the IKE level, in - which each gateway authenticates the other. This can be done in a - variety of ways.</P> -</DD> -<DT>Encryption</DT> -<DD>Encryption allows you to conceal the contents of a message from - eavesdroppers. -<P>In IPsec this is done using a<A href="glossary.html#block"> block - cipher</A> (normally<A href="glossary.html#3DES"> Triple DES</A> for - Linux). In the most used setup, keys are automatically negotiated, and - periodically re-negotiated, using the<A href="glossary.html#IKE"> IKE</A> - (Internet Key Exchange) protocol. In Linux FreeS/WAN this is handled by - the Pluto Daemon.</P> -<P>The IPsec protocol offering encryption is<A href="glossary.html#ESP"> - ESP</A>, Encapsulated Security Payload. It can also include a packet - authentication service.</P> -</DD> -</DL> -<P>Note that<STRONG> encryption should always be used with some packet - authentication service</STRONG>. Unauthenticated encryption is - vulnerable to<A href="glossary.html#middle"> man-in-the-middle attacks</A> -. Also note that encryption does not prevent<A href="glossary.html#traffic"> - traffic analysis</A>.</P> -<H3><A name="AH.ipsec">The Authentication Header (AH)</A></H3> -<P>Packet authentication can be provided separately from encryption by - adding an authentication header (AH) after the IP header but before the - other headers on the packet. This is the subject of this section. - Details are in RFC 2402.</P> -<P>Each of the several headers on a packet header contains a "next - protocol" field telling the system what header to look for next. IP - headers generally have either TCP or UDP in this field. When IPsec - authentication is used, the packet IP header has AH in this field, - saying that an Authentication Header comes next. The AH header then has - the next header type -- usually TCP, UDP or encapsulated IP.</P> -<P>IPsec packet authentication can be added in transport mode, as a - modification of standard IP transport. This is shown in this diagram - from the RFC:</P> -<PRE> BEFORE APPLYING AH - ---------------------------- - IPv4 |orig IP hdr | | | - |(any options)| TCP | Data | - ---------------------------- - - AFTER APPLYING AH - --------------------------------- - IPv4 |orig IP hdr | | | | - |(any options)| AH | TCP | Data | - --------------------------------- - || - except for mutable fields</PRE> -<P>Athentication can also be used in tunnel mode, encapsulating the - underlying IP packet beneath AH and an additional IP header.</P> -<PRE> || -IPv4 | new IP hdr* | | orig IP hdr* | | | - |(any options)| AH | (any options) |TCP | Data | - ------------------------------------------------ - || - | in the new IP hdr |</PRE> -<P>This would normally be used in a gateway-to-gateway tunnel. The - receiving gateway then strips the outer IP header and the AH header and - forwards the inner IP packet.</P> -<P>The mutable fields referred to are things like the time-to-live field - in the IP header. These cannot be included in authentication - calculations because they change as the packet travels.</P> -<H4><A name="keyed">Keyed MD5 and Keyed SHA</A></H4> -<P>The actual authentication data in the header is typically 96 bits and - depends both on a secret shared between sender and receiver and on - every byte of the data being authenticated. The technique used is<A href="glossary.html#HMAC"> - HMAC</A>, defined in RFC 2104.</P> -<P>The algorithms involved are the<A href="glossary.html#MD5"> MD5</A> - Message Digest Algorithm or<A href="glossary.html#SHA"> SHA</A>, the - Secure Hash Algorithm. For details on their use in this application, - see RFCs 2403 and 2404 respectively.</P> -<P>For descriptions of the algorithms themselves, see RFC 1321 for MD5 - and<A href="glossary.html#FIPS"> FIPS</A> (Federal Information - Processing Standard) number 186 from<A href="glossary.html#NIST"> NIST</A> -, the US National Institute of Standards and Technology for SHA.<A href="biblio.html#schneier"> -<CITE> Applied Cryptography</CITE></A> covers both in some detail, MD5 - starting on page 436 and SHA on 442.</P> -<P>These algorithms are intended to make it nearly impossible for anyone - to alter the authenticated data in transit. The sender calculates a - digest or hash value from that data and includes the result in the - authentication header. The recipient does the same calculation and - compares results. For unchanged data, the results will be identical. - The hash algorithms are designed to make it extremely difficult to - change the data in any way and still get the correct hash.</P> -<P>Since the shared secret key is also used in both calculations, an - interceptor cannot simply alter the authenticated data and change the - hash value to match. Without the key, he or she (or even the dreaded - They) cannot produce a usable hash.</P> -<H4><A name="sequence">Sequence numbers</A></H4> -<P>The authentication header includes a sequence number field which the - sender is required to increment for each packet. The receiver can - ignore it or use it to check that packets are indeed arriving in the - expected sequence.</P> -<P>This provides partial protection against<A href="glossary.html#replay"> - replay attacks</A> in which an attacker resends intercepted packets in - an effort to confuse or subvert the receiver. Complete protection is - not possible since it is necessary to handle legitmate packets which - are lost, duplicated, or delivered out of order, but use of sequence - numbers makes the attack much more difficult.</P> -<P>The RFCs require that sequence numbers never cycle, that a new key - always be negotiated before the sequence number reaches 2^32-1. This - protects both against replays attacks using packets from a previous - cyclce and against<A href="glossary.html#birthday"> birthday attacks</A> - on the the packet authentication algorithm.</P> -<P>In Linux FreeS/WAN, the sequence number is ignored for manually keyed - connections and checked for automatically keyed ones. In manual mode, - there is no way to negotiate a new key, or to recover from a sequence - number problem, so we don't use sequence numbers.</P> -<H3><A name="ESP.ipsec">Encapsulated Security Payload (ESP)</A></H3> -<P>The ESP protocol is defined in RFC 2406. It provides one or both of - encryption and packet authentication. It may be used with or without AH - packet authentication.</P> -<P>Note that<STRONG> some form of packet authentication should<EM> - always</EM> be used whenever data is encrypted</STRONG>. Without - authentication, the encryption is vulnerable to active attacks which - may allow an enemy to break the encryption. ESP should<STRONG> always</STRONG> - either include its own authentication or be used with AH - authentication.</P> -<P>The RFCs require support for only two mandatory encryption algorithms - --<A href="glossary.html#DES"> DES</A>, and null encryption -- and for - two authentication methods -- keyed MD5 and keyed SHA. Implementers may - choose to support additional algorithms in either category.</P> -<P>The authentication algorithms are the same ones used in the IPsec<A href="glossary.html#AH"> - authentication header</A>.</P> -<P>We do not implement single DES since<A href="politics.html#desnotsecure"> - DES is insecure</A>. Instead we provide<A href="glossary.html#3DES"> - triple DES or 3DES</A>. This is currently the only encryption algorithm - supported.</P> -<P>We do not implement null encryption since it is obviously insecure.</P> -<H2><A name="modes">IPsec modes</A></H2> -<P>IPsec can connect in two modes. Transport mode is a host-to-host - connection involving only two machines. In tunnel mode, the IPsec - machines act as gateways and trafiic for any number of client machines - may be carried.</P> -<H3><A name="tunnel.ipsec">Tunnel mode</A></H3> -<P>Security gateways are required to support tunnel mode connections. In - this mode the gateways provide tunnels for use by client machines - behind the gateways. The client machines need not do any IPsec - processing; all they have to do is route things to gateways.</P> -<H3><A name="transport.ipsec">Transport mode</A></H3> -<P>Host machines (as opposed to security gateways) with IPsec - implementations must also support transport mode. In this mode, the - host does its own IPsec processing and routes some packets via IPsec.</P> -<H2><A name="parts">FreeS/WAN parts</A></H2> -<H3><A name="KLIPS.ipsec">KLIPS: Kernel IPsec Support</A></H3> -<P>KLIPS is<STRONG> K</STRONG>erne<STRONG>L</STRONG><STRONG> IP</STRONG> -SEC<STRONG> S</STRONG>upport, the modifications necessary to support - IPsec within the Linux kernel. KILPS does all the actual IPsec - packet-handling, including</P> -<UL> -<LI>encryption</LI> -<LI>packet authentication calculations</LI> -<LI>creation of ESP and AH headers for outgoing packets</LI> -<LI>interpretation of those headers on incoming packets</LI> -</UL> -<P>KLIPS also checks all non-IPsec packets to ensure they are not - bypassing IPsec security policies.</P> -<H3><A name="Pluto.ipsec">The Pluto daemon</A></H3> -<P><A href="manpage.d/ipsec_pluto.8.html">Pluto(8)</A> is a daemon which - implements the IKE protocol. It</P> -<UL> -<LI>handles all the Phase one ISAKMP SAs</LI> -<LI>performs host authentication and negotiates with other gateways</LI> -<LI>creates IPsec SAs and passes the data required to run them to KLIPS</LI> -<LI>adjust routing and firewall setup to meet IPsec requirements. See - our<A href="firewall.html"> IPsec and firewalling</A> document for - details.</LI> -</UL> -<P>Pluto is controlled mainly by the<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A> configuration file.</P> -<H3><A name="command">The ipsec(8) command</A></H3> -<P>The<A href="manpage.d/ipsec.8.html"> ipsec(8)</A> command is a front - end shellscript that allows control over IPsec activity.</P> -<H3><A name="ipsec.conf">Linux FreeS/WAN configuration file</A></H3> -<P>The configuration file for Linux FreeS/WAN is</P> -<PRE> /etc/ipsec.conf</PRE> -<P>For details see the<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A> manual page .</P> -<H2><A name="key">Key management</A></H2> -<P>There are several ways IPsec can manage keys. Not all are implemented - in Linux FreeS/WAN.</P> -<H3><A name="current">Currently Implemented Methods</A></H3> -<H4><A name="manual">Manual keying</A></H4> -<P>IPsec allows keys to be manually set. In Linux FreeS/WAN, such keys - are stored with the connection definitions in /etc/ipsec.conf.</P> -<P><A href="glossary.html#manual">Manual keying</A> is useful for - debugging since it allows you to test the<A href="glossary.html#KLIPS"> - KLIPS</A> kernel IPsec code without the<A href="glossary.html#Pluto"> - Pluto</A> daemon doing key negotiation.</P> -<P>In general, however, automatic keying is preferred because it is more - secure.</P> -<H4><A name="auto">Automatic keying</A></H4> -<P>In automatic keying, the<A href="glossary.html#Pluto"> Pluto</A> - daemon negotiates keys using the<A href="glossary.html#IKE"> IKE</A> - Internet Key Exchange protocol. Connections are automatically re-keyed - periodically.</P> -<P>This is considerably more secure than manual keying. In either case - an attacker who acquires a key can read every message encrypted with - that key, but automatic keys can be changed every few hours or even - every few minutes without breaking the connection or requiring - intervention by the system administrators. Manual keys can only be - changed manually; you need to shut down the connection and have the two - admins make changes. Moreover, they have to communicate the new keys - securely, perhaps with<A href="glossary.html#PGP"> PGP</A> or<A href="glossary.html#SSH"> - SSH</A>. This may be possible in some cases, but as a general solution - it is expensive, bothersome and unreliable. Far better to let<A href="glossary.html#Pluto"> - Pluto</A> handle these chores; no doubt the administrators have enough - to do.</P> -<P>Also, automatic keying is inherently more secure against an attacker - who manages to subvert your gateway system. If manual keying is in use - and an adversary acquires root privilege on your gateway, he reads your - keys from /etc/ipsec.conf and then reads all messages encrypted with - those keys.</P> -<P>If automatic keying is used, an adversary with the same privileges - can read /etc/ipsec.secrets, but this does not contain any keys, only - the secrets used to authenticate key exchanges. Having an adversary - able to authenticate your key exchanges need not worry you overmuch. - Just having the secrets does not give him any keys. You are still - secure against<A href="glossary.html#passive"> passive</A> attacks. - This property of automatic keying is called<A href="glossary.html#PFS"> - perfect forward secrecy</A>, abbreviated PFS.</P> -<P>Unfortunately, having the secrets does allow an<A href="glossary.html#active"> - active attack</A>, specifically a<A href="glossary.html#middle"> - man-in-the-middle</A> attack. Losing these secrets to an attacker may - not be quite as disastrous as losing the actual keys, but it is<EM> - still a serious security breach</EM>. These secrets should be guarded - as carefully as keys.</P> -<H3><A name="notyet">Methods not yet implemented</A></H3> -<H4><A name="noauth">Unauthenticated key exchange</A></H4> -<P>It would be possible to exchange keys without authenticating the - players. This would support<A href="glossary.html#carpediem"> - opportunistic encryption</A> -- allowing any two systems to encrypt - their communications without requiring a shared PKI or a previously - negotiated secret -- and would be secure against<A href="glossary.html#passive"> - passive attacks</A>. It would, however, be highly vulnerable to active<A -href="glossary.html#middle"> man-in-the-middle</A> attacks. RFC 2408 - therefore specifies that all<A href="glossary.html#ISAKMP"> ISAKMP</A> - key management interactions<EM> must</EM> be authenticated.</P> -<P>There is room for debate here. Should we provide immediate security - against<A href="glossary.html#passive"> passive attacks</A> and - encourage widespread use of encryption, at the expense of risking the - more difficult<A href="glossary.html#active"> active attacks</A>? Or - should we wait until we can implement a solution that can both be - widespread and offer security against active attacks?</P> -<P>So far, we have chosen the second course, complying with the RFCs and - waiting for secure DNS (see<A href="glossary.html#DNS"> below</A>) so - that we can do<A href="glossary.html#carpediem"> opportunistic - encryption</A> right.</P> -<H4><A name="DNS">Key exchange using DNS</A></H4> -<P>The IPsec RFCs allow key exchange based on authentication services - provided by<A href="glossary.html#SDNS"> Secure DNS</A>. Once Secure - DNS service becomes widely available, we expect to make this the<EM> - primary key management method for Linux FreeS/WAN</EM>. It is the best - way we know of to support<A href="glossary.html#carpediem"> - opportunistic encryption</A>, allowing two systems without a common PKI - or previous negotiation to secure their communication.</P> -<P>We currently have code to acquire RSA keys from DNS but do not yet - have code to validate Secure DNS signatures.</P> -<H4><A name="PKI">Key exchange using a PKI</A></H4> -<P>The IPsec RFCs allow key exchange based on authentication services - provided by a<A href="glossary.html#PKI"> PKI</A> or Public Key - Infrastructure. With many vendors selling such products and many large - organisations building these infrastructures, this will clearly be an - important application of IPsec and one Linux FreeS/WAN will eventually - support.</P> -<P>On the other hand, this is not as high a priority for Linux FreeS/WAN - as solutions based on<A href="glossary.html#SDNS"> secure DNS</A>. We - do not expect any PKI to become as universal as DNS.</P> -<P>Some<A href="web.html#patch"> patches</A> to handle authentication - with X.509 certificates, which most PKIs use, are available.</P> -<H4><A name="photuris">Photuris</A></H4> -<P><A href="glossary.html#photuris">Photuris</A> is another key - management protocol, an alternative to IKE and ISAKMP, described in - RFCs 2522 and 2523 which are labelled "experimental". Adding Photuris - support to Linux FreeS/WAN might be a good project for a volunteer. The - likely starting point would be the OpenBSD photurisd code.</P> -<H4><A name="skip">SKIP</A></H4> -<P><A href="glossary.html#SKIP">SKIP</A> is yet another key management - protocol, developed by Sun. At one point it was fairly widely used, but - it now seems moribund, displaced by IKE. Sun now (as of Solaris 8.0) - ship an IPsec implementation using IKE. We have no plans to implement - SKIP. If a user were to implement it, we would almost certainly not - want to add the code to our distribution.</P> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="politics.html">Previous</A> -<A HREF="mail.html">Next</A> -</BODY> -</HTML> diff --git a/doc/kernel.html b/doc/kernel.html deleted file mode 100644 index de305683a..000000000 --- a/doc/kernel.html +++ /dev/null @@ -1,353 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="testing.html">Previous</A> -<A HREF="adv_config.html">Next</A> -<HR> -<H1><A name="kernelconfig">Kernel configuration for FreeS/WAN</A></H1> -<P> This section lists many of the options available when configuring a - Linux kernel, and explains how they should be set on a FreeS/WAN IPsec - gateway.</P> -<H2><A name="notall">Not everyone needs to worry about kernel - configuration</A></H2> -<P>Note that in many cases you do not need to mess with these.</P> -<P> You may have a Linux distribution which comes with FreeS/WAN - installed (see this<A href="intro.html#products"> list</A>). In that - case, you need not do a FreeS/WAN installation or a kernel - configuration. Of course, you might still want to configure and rebuild - your kernel to improve performance or security. This can be done with - standard tools described in the<A href="http://www.linuxdoc.org/HOWTO/Kernel-HOWTO.html"> - Kernel HowTo</A>.</P> -<P>If you need to install FreeS/WAN, then you do need to configure a - kernel. However, you may choose to do that using the simplest - procedure:</P> -<UL> -<LI>Configure, build and test a kernel for your system before adding - FreeS/WAN. See the<A href="http://www.linuxdoc.org/HOWTO/Kernel-HOWTO.html"> - Kernel HowTo</A> for details.<STRONG> This step cannot be skipped</STRONG> -. FreeS/WAN needs the results of your configuration.</LI> -<LI>Then use FreeS/WAN's<VAR> make oldgo</VAR> command. This sets - everything FreeS/WAN needs and retains your values everywhere else.</LI> -</UL> -<P> This document is for those who choose to configure their FreeS/WAN - kernel themselves.</P> -<H2><A name="assume">Assumptions and notation</A></H2> -<P> Help text for most kernel options is included with the kernel files, - and is accessible from within the configuration utilities. We assume - you will refer to that, and to the<A href="http://www.linuxdoc.org/HOWTO/Kernel-HOWTO.html"> - Kernel HowTo</A>, as necessary. This document covers only the - FreeS/WAN-specific aspects of the problem.</P> -<P> To avoid duplication, this document section does not cover settings - for the additional IPsec-related kernel options which become available - after you have patched your kernel with FreeS/WAN patches. There is - help text for those available from within the configuration utility.</P> -<P> We assume a common configuration in which the FreeS/WAN IPsec - gateway is also doing ipchains(8) firewalling for a local network, and - possibly masquerading as well.</P> -<P> Some suggestions below are labelled as appropriate for "a true - paranoid". By this we mean they may cause inconvenience and it is not - entirely clear they are necessary, but they appear to be the safest - choice. Not using them might entail some risk. Of course one suggested - mantra for security administrators is: "I know I'm paranoid. I wonder - if I'm paranoid enough."</P> -<H3><A name="labels">Labels used</A></H3> -<P> Six labels are used to indicate how options should be set. We mark - the labels with [square brackets]. For two of these labels, you have no - choice:</P> -<DL> -<DT>[required]</DT> -<DD>essential for FreeS/WAN operation.</DD> -<DT>[incompatible]</DT> -<DD>incompatible with FreeS/WAN.</DD> -</DL> -<P>those must be set correctly or FreeS/WAN will not work</P> -<P>FreeS/WAN should work with any settings of the others, though of - course not all combinations have been tested. We do label these in - various ways, but<EM> these labels are only suggestions</EM>.</P> -<DL> -<DT>[recommended]</DT> -<DD>useful on most FreeS/WAN gateways</DD> -<DT>[disable]</DT> -<DD>an unwelcome complication on a FreeS/WAN gateway.</DD> -<DT>[optional]</DT> -<DD>Your choice. We outline issues you might consider.</DD> -<DT>[anything]</DT> -<DD>This option has no direct effect on FreeS/WAN and related tools, so - you should be able to set it as you please.</DD> -</DL> -<P> Of course complexity is an enemy in any effort to build secure - systems.<STRONG> For maximum security, any feature that can reasonably - be turned off should be</STRONG>. "If in doubt, leave it out."</P> -<H2><A name="kernelopt">Kernel options for FreeS/WAN</A></H2> -<P> Indentation is based on the nesting shown by 'make menuconfig' with - a 2.2.16 kernel for the i386 architecture.</P> -<DL> -<DT><A name="maturity">Code maturity and level options</A></DT> -<DD> -<DL> -<DT><A name="devel">Prompt for development ... code/drivers</A></DT> -<DD>[optional] If this is<VAR> no</VAR>, experimental drivers are not - shown in later menus. -<P>For most FreeS/WAN work,<VAR> no</VAR> is the preferred setting. - Using new or untested components is too risky for a security gateway.</P> -<P>However, for some hardware (such as the author's network cards) the - only drivers available are marked<VAR> new/experimental</VAR>. In such - cases, you must enable this option or your cards will not appear under - "network device support". A true paranoid would leave this option off - and replace the cards.</P> -</DD> -<DT>Processor type and features</DT> -<DD>[anything]</DD> -<DT>Loadable module support</DT> -<DD> -<DL> -<DT>Enable loadable module support</DT> -<DD>[optional] A true paranoid would disable this. An attacker who has - root access to your machine can fairly easily install a bogus module - that does awful things, provided modules are enabled. A common tool for - attackers is a "rootkit", a set of tools the attacker uses once he or - she has become root on your system. The kit introduces assorted - additional compromises so that the attacker will continue to "own" your - system despite most things you might do to recovery the situation. For - Linux, there is a tool called<A href="http://www.sans.org/newlook/resources/IDFAQ/knark.htm"> - knark</A> which is basically a rootkit packaged as a kernel module. -<P>With modules disabled, an attacker cannot install a bogus module. The - only way he can achieve the same effects is to install a new kernel and - reboot. This is considerably more likely to be noticed.</P> -<P>Many FreeS/WAN gateways run with modules enabled. This simplifies - some administrative tasks and some ipchains features are available only - as modules. Once an enemy has root on your machine your security is - nil, so arguably defenses which come into play only in that situation - are pointless.</P> -<P></P> -</DD> -<DT>Set version information ....</DT> -<DD>[optional] This provides a check to prevent loading modules compiled - for a different kernel.</DD> -<DT>Kernel module loader</DT> -<DD>[disable] It gives little benefit on a typical FreeS/WAN gate and - entails some risk.</DD> -</DL> -</DD> -<DT>General setup</DT> -<DD>We list here only the options that matter for FreeS/WAN. -<DL> -<DT>Networking support</DT> -<DD>[required]</DD> -<DT>Sysctl interface</DT> -<DD>[optional] If this option is turned on and the<VAR> /proc</VAR> - filesystem installed, then you can control various system behaviours by - writing to files under<VAR> /proc/sys</VAR>. For example: -<PRE> echo 1 > /proc/sys/net/ipv4/ipforward</PRE> - turns IP forwarding on. -<P>Disabling this option breaks many firewall scripts. A true paranoid - would disable it anyway since it might conceivably be of use to an - attacker.</P> -</DD> -</DL> -</DD> -<DT>Plug and Play support</DT> -<DD>[anything]</DD> -<DT>Block devices</DT> -<DD>[anything]</DD> -<DT>Networking options</DT> -<DD> -<DL> -<DT>Packet socket</DT> -<DD>[optional] This kernel feature supports tools such as tcpdump(8) - which communicate directly with network hardware, bypassing kernel - protocols. This is very much a two-edged sword: -<UL> -<LI>such tools can be very useful to the firewall admin, especially - during initial testing</LI> -<LI>should an evildoer breach your firewall, such tools could give him - or her a great deal of information about the rest of your network</LI> -</UL> - We recommend disabling this option on production gateways.</DD> -<DT><A name="netlink">Kernel/User netlink socket</A></DT> -<DD>[optional] Required if you want to use<A href="#adv"> advanced - router</A> features.</DD> -<DT>Routing messages</DT> -<DD>[optional]</DD> -<DT>Netlink device emulation</DT> -<DD>[optional]</DD> -<DT>Network firewalls</DT> -<DD>[recommended] You need this if the IPsec gateway also functions as a - firewall. -<P>Even if the IPsec gateway is not your primary firewall, we suggest - setting this so that you can protect the gateway with at least basic - local packet filters.</P> -</DD> -<DT>Socket filtering</DT> -<DD>[disable] This enables an older filtering interface. We suggest - using ipchains(8) instead. To do that, set the "Network firewalls" - option just above, and not this one.</DD> -<DT>Unix domain sockets</DT> -<DD>[required] These sockets are used for communication between the<A href="manpage.d/ipsec.8.html"> - ipsec(8)</A> commands and the<A href="manpage.d/ipsec_pluto.8.html"> - ipsec_pluto(8)</A> daemon.</DD> -<DT>TCP/IP networking</DT> -<DD>[required] -<DL> -<DT>IP: multicasting</DT> -<DD>[anything]</DD> -<DT><A name="adv">IP: advanced router</A></DT> -<DD>[optional] This gives you policy routing, which some people have - used to good advantage in their scripts for FreeS/WAN gateway - management. It is not used in our distributed scripts, so not required - unless you want it for custom scripts. It requires the<A href="#netlink"> - netlink</A> interface between kernel code and the iproute2(8) command.</DD> -<DT>IP: kernel level autoconfiguration</DT> -<DD>[disable] It gives little benefit on a typical FreeS/WAN gate and - entails some risk.</DD> -<DT>IP: firewall packet netlink device</DT> -<DD>[disable]</DD> -<DT>IP: transparent proxy support</DT> -<DD>[optional] This is required in some firewall configurations, but - should be disabled unless you have a definite need for it.</DD> -<DT>IP: masquerading</DT> -<DD>[optional] Required if you want to use<A href="glossary.html#non-routable"> - non-routable</A> private IP addresses for your local network.</DD> -<DT>IP: Optimize as router not host</DT> -<DD>[recommended]</DD> -<DT>IP: tunneling</DT> -<DD>[required]</DD> -<DT>IP: GRE tunnels over IP</DT> -<DD>[anything]</DD> -<DT>IP: aliasing support</DT> -<DD>[anything]</DD> -<DT>IP: ARP daemon support (EXPERIMENTAL)</DT> -<DD>Not required on most systems, but might prove useful on - heavily-loaded gateways.</DD> -<DT>IP: TCP syncookie support</DT> -<DD>[recommended] It provides a defense against a<A href="glossary.html#DOS"> - denial of service attack</A> which uses bogus TCP connection requests - to waste resources on the victim machine.</DD> -<DT>IP: Reverse ARP</DT> -<DD></DD> -<DT>IP: large window support</DT> -<DD>[recommended] unless you have less than 16 meg RAM</DD> -</DL> -</DD> -<DT>IPv6</DT> -<DD>[optional] FreeS/WAN does not currently support IPv6, though work on - integrating FreeS/WAN with the Linux IPv6 stack has begun.<A href="compat.html#ipv6"> - Details</A>. -<P> It should be possible to use IPv4 FreeS/WAN on a machine which also - does IPv6. This combination is not yet well tested. We would be quite - interested in hearing results from anyone expermenting with it, via the<A -href="mail.html"> mailing list</A>.</P> -<P> We do not recommend using IPv6 on production FreeS/WAN gateways - until more testing has been done.</P> -</DD> -<DT>Novell IPX</DT> -<DD>[disable]</DD> -<DT>Appletalk</DT> -<DD>[disable] Quite a few Linux installations use IP but also have some - other protocol, such as Appletalk or IPX, for communication with local - desktop machines. In theory it should be possible to configure IPsec - for the IP side of things without interfering with the second protocol. -<P>We do not recommend this. Keep the software on your gateway as simple - as possible. If you need a Linux-based Appletalk or IPX server, use a - separate machine.</P> -</DD> -</DL> -</DD> -<DT>Telephony support</DT> -<DD>[anything]</DD> -<DT>SCSI support</DT> -<DD>[anything]</DD> -<DT>I2O device support</DT> -<DD>[anything]</DD> -<DT>Network device support</DT> -<DD>[anything] should work, but there are some points to note. -<P>The development team test almost entirely on 10 or 100 megabit - Ethernet and modems. In principle, any device that can do IP should be - just fine for IPsec, but in the real world any device that has not been - well-tested is somewhat risky. By all means try it, but don't bet your - project on it until you have solid test results.</P> -<P>If you disabled experimental drivers in the<A href="#maturity"> Code - maturity</A> section above, then those drivers will not be shown here. - Check that option before going off to hunt for missing drivers.</P> -<P>If you want Linux to automatically find more than one ethernet - interface at boot time, you need to:</P> -<UL> -<LI>compile the appropriate driver(s) into your kernel. Modules will not - work for this</LI> -<LI>add a line such as -<PRE> - append="ether=0,0,eth0 ether=0,0,eth1" -</PRE> - to your /etc/lilo.conf file. In some cases you may need to specify - parameters such as IRQ or base address. The example uses "0,0" for - these, which tells the system to search. If the search does not succeed - on your hardware, then you should retry with explicit parameters. See - the lilo.conf(5) man page for details.</LI> -<LI>run lilo(8)</LI> -</UL> - Having Linux find the cards this way is not necessary, but is usually - more convenient than loading modules in your boot scripts.</DD> -<DT>Amateur radio support</DT> -<DD>[anything]</DD> -<DT>IrDA (infrared) support</DT> -<DD>[anything]</DD> -<DT>ISDN subsystem</DT> -<DD>[anything]</DD> -<DT>Old CDROM drivers</DT> -<DD>[anything]</DD> -<DT>Character devices</DT> -<DD>The only required character device is: -<DL> -<DT>random(4)</DT> -<DD>[required] This is a source of<A href="glossary.html#random"> random</A> - numbers which are required for many cryptographic protocols, including - several used in IPsec. -<P>If you are comfortable with C source code, it is likely a good idea - to go in and adjust the<VAR> #define</VAR> lines in<VAR> - /usr/src/linux/drivers/char/random.c</VAR> to ensure that all sources - of randomness are enabled. Relying solely on keyboard and mouse - randomness is dubious procedure for a gateway machine. You could also - increase the randomness pool size from the default 512 bytes (128 - 32-bit words).</P> -</DD> -</DL> -</DD> -<DT>Filesystems</DT> -<DD>[anything] should work, but we suggest limiting a gateway machine to - the standard Linux ext2 filesystem in most cases.</DD> -<DT>Network filesystems</DT> -<DD>[disable] These systems are an unnecessary risk on an IPsec gateway.</DD> -<DT>Console drivers</DT> -<DD>[anything]</DD> -<DT>Sound</DT> -<DD>[anything] should work, but we suggest enabling sound only if you - plan to use audible alarms for firewall problems.</DD> -<DT>Kernel hacking</DT> -<DD>[disable] This might be enabled on test machines, but should not be - on production gateways.</DD> -</DL> -</DD> -</DL> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="testing.html">Previous</A> -<A HREF="adv_config.html">Next</A> -</BODY> -</HTML> diff --git a/doc/mail.html b/doc/mail.html deleted file mode 100644 index 68b5d8cd8..000000000 --- a/doc/mail.html +++ /dev/null @@ -1,216 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="ipsec.html">Previous</A> -<A HREF="web.html">Next</A> -<HR> -<H1><A name="lists">Mailing lists and newsgroups</A></H1> -<H2><A name="list.fs">Mailing lists about FreeS/WAN</A></H2> -<H3><A name="projlist">The project mailing lists</A></H3> -<P>The Linux FreeS/WAN project has several email lists for user support, - bug reports and software development discussions.</P> -<P>We had a single list on clinet.fi for several years (Thanks, folks!), - then one list on freeswan.org, but now we've split into several lists:</P> -<DL> -<DT><A href="mailto:users-request@lists.freeswan.org?body=subscribe"> -users</A></DT> -<DD> -<UL> -<LI>The general list for discussing use of the software</LI> -<LI>The place for seeking<STRONG> help with problems</STRONG> (but - please check the<A href="faq.html"> FAQ</A> first).</LI> -<LI>Anyone can post.</LI> -</UL> -</DD> -<DT><A href="mailto:bugs-request@lists.freeswan.org?body=subscribe">bugs</A> -</DT> -<DD> -<UL> -<LI>For<STRONG> bug reports</STRONG>.</LI> -<LI>If you are not certain what is going on -- could be a bug, a - configuration error, a network problem, ... -- please post to the users - list instead.</LI> -<LI>Anyone can post.</LI> -</UL> -</DD> -<DT><A href="mailto:design-request@lists.freeswan.org?body=subscribe"> -design</A></DT> -<DD> -<UL> -<LI><STRONG>Design discussions</STRONG>, for people working on FreeS/WAN - development or others with an interest in design and security issues.</LI> -<LI>It would be a good idea to read the existing design papers (see this<A -href="intro.html#applied"> list</A>) before posting.</LI> -<LI>Anyone can post.</LI> -</UL> -</DD> -<DT><A href="mailto:announce-request@lists.freeswan.org?body=subscribe"> -announce</A></DT> -<DD> -<UL> -<LI>A<STRONG> low-traffic</STRONG> list.</LI> -<LI><STRONG>Announcements</STRONG> about FreeS/WAN and related software.</LI> -<LI>All posts here are also sent to the users list. You need not - subscribe to both.</LI> -<LI>Only the FreeS/WAN team can post.</LI> -<LI>If you have something you feel should go on this list, send it to<VAR> - announce-admin@lists.freeswan.org</VAR>. Unless it is obvious, please - include a short note explaining why we should post it.</LI> -</UL> -</DD> -<DT><A href="mailto:briefs-request@lists.freeswan.org?body=subscribe"> -briefs</A></DT> -<DD> -<UL> -<LI>A<STRONG> low-traffic</STRONG> list.</LI> -<LI><STRONG>Weekly summaries</STRONG> of activity on the users list.</LI> -<LI>All posts here are also sent to the users list. You need not - subscribe to both.</LI> -<LI>Only the FreeS/WAN team can post.</LI> -</UL> -</DD> -</DL> -<P>To subscribe to any of these, you can:</P> -<UL> -<LI>just follow the links above</LI> -<LI>use our<A href="http://www.freeswan.org/mail.html"> web interface</A> -</LI> -<LI>send mail to<VAR> listname</VAR>-request@lists.freeswan.org with a - one-line message body "subscribe"</LI> -</UL> -<P>Archives of these lists are available via the<A href="http://www.freeswan.org/mail.html"> - web interface</A>.</P> -<H4><A name="which.list">Which list should I use?</A></H4> -<P>For most questions, please check the<A href="faq.html"> FAQ</A> - first, and if that does not have an answer, ask on the users list. "My - configuration doesn't work." does not belong on the bugs list, and "Can - FreeS/WAN do such-and-such" or "How do I configure it to..." do not - belong in design discussions.</P> -<P>Cross-posting the same message to two or more of these lists is - discouraged. Quite a few people read more than one list and getting - multiple copies is annoying.</P> -<H4><A name="policy.list">List policies</A></H4> -<P><STRONG>US citizens or residents are asked not to post code to the - lists, not even one-line bug fixes</STRONG>. The project cannot accept - code which might entangle it in US<A href="politics.html#exlaw"> export - restrictions</A>.</P> -<P>Non-subscribers can post to some of these lists. This is necessary; - someone working on a gateway install who encounters a problem may not - have access to a subscribed account.</P> -<P>Some spam turns up on these lists from time to time. For discussion - of why we do not attempt to filter it, see the<A href="faq.html#spam"> - FAQ</A>. Please do not clutter the lists with complaints about this.</P> -<H3><A name="archive">Archives of the lists</A></H3> -<P>Searchable archives of the old single list have existed for some - time. At time of writing, it is not yet clear how they will change for - the new multi-list structure.</P> -<UL> -<LI><A href="http://www.sandelman.ottawa.on.ca/linux-ipsec">Canada</A></LI> -<LI><A href="http://www.nexial.com">Holland</A></LI> -</UL> -<P>Note that these use different search engines. Try both.</P> -<P>Archives of the new lists are available via the<A href="http://www.freeswan.org/mail.html"> - web interface</A>.</P> -<H2><A name="indexes">Indexes of mailing lists</A></H2> -<P><A href="http://paml.net/">PAML</A> is the standard reference for<STRONG> - P</STRONG>ublicly<STRONG> A</STRONG>ccessible<STRONG> M</STRONG>ailing<STRONG> - L</STRONG>ists. When we last checked, it had over 7500 lists on an - amazing variety of topics. It also has FAQ information and a search - engine.</P> -<P>There is an index of<A href="http://oslab.snu.ac.kr/~djshin/linux/mail-list/index.shtml"> - Linux mailing lists</A> available.</P> -<P>A list of<A href="http://xforce.iss.net/maillists/otherlists.php"> - computer security mailing lists</A>, with descriptions.</P> -<H2><A name="otherlists">Lists for related software and topics</A></H2> -<P>Most links in this section point to subscription addresses for the - various lists. Send the one-line message "subscribe<VAR> list_name</VAR> -" to subscribe to any of them.</P> -<H3><A NAME="28_3_1">Products that include FreeS/WAN</A></H3> -<P>Our introduction document gives a<A href="intro.html#products"> list - of products that include FreeS/WAN</A>. If you have, or are - considering, one of those, check the supplier's web site for - information on mailing lists for their users.</P> -<H3><A name="linux.lists">Linux mailing lists</A></H3> -<UL> -<LI><A href="mailto:majordomo@vger.kernel.org"> -linux-admin@vger.kernel.org</A>, for Linux system administrators</LI> -<LI><A href="mailto:netfilter-request@lists.samba.org"> -netfilter@lists.samba.org</A>, about Netfilter, which replaces IPchains - in kernels 2.3.15 and later</LI> -<LI><A href="mailto:security-audit-request@ferret.lmh.ox.ac.uk"> -security-audit@ferret.lmh.ox.ac.uk</A>, for people working on security - audits of various Linux programs</LI> -<LI><A href="mailto:securedistros-request@humbolt.geo.uu.nl"> -securedistros@humbolt.geo.uu.nl</A>, for discussion of issues common to - all the half dozen projects working on secure Linux distributions.</LI> -</UL> -<P>Each of the scure distribution projects also has its own web site and - mailing list. Some of the sites are:</P> -<UL> -<LI><A href="http://bastille-linux.org/">Bastille Linux</A> scripts to - harden Redhat, e.g. by changing permissions and modifying inialisation - scripts</LI> -<LI><A href="http://immunix.org/">Immunix</A> take a different approach, - using a modified compiler to build kernel and utilities with better - resistance to various types of overflow and exploit</LI> -<LI>the<A href="glossary.html#NSA"> NSA</A> have contractors working on - a<A href="glossary.html#SElinux"> Security Enhanced Linux</A>, - primarily adding stronger access control mechanisms. You can download - the current version (which interestingly is under GPL and not export - resrtricted) or subscribe to the mailing list from the<A href="http://www.nsa.gov/selinux"> - project web page</A>.</LI> -</UL> -<H3><A name="ietf">Lists for IETF working groups</A></H3> -<P>Each<A href="glossary.html#IETF"> IETF</A> working group has an - associated mailing list where much of the work takes place.</P> -<UL> -<LI><A href="mailto:majordomo@lists.tislabs.com">ipsec@lists.tislabs.com</A> -, the IPsec<A href="http://www.ietf.org/html.charters/ipsec-charter.html"> - working group</A>. This is where the protocols are discussed, new - drafts announced, and so on. By now, the IPsec working group is winding - down since the work is essentially complete. A<A href="http://www.sandelman.ottawa.on.ca/ipsec/"> - list archive</A> is available.</LI> -<LI><A href="mailto:ipsec-policy-request@vpnc.org">IPsec policy</A> - list, and its<A href="http://www.vpnc.org/ipsec-policy/"> archive</A></LI> -<LI><A href="mailto:ietf-ipsra-request@vpnc.org">IP secure remote access</A> - list, and its<A href="http://www.vpnc.org/ietf-ipsra/mail-archive/"> - archive</A></LI> -</UL> -<H3><A name="other">Other mailing lists</A></H3> -<UL> -<LI><A href="mailto:ipc-announce-request@privacy.org"> -ipc-announce@privacy.org</A> a low-traffic list with announcements of - developments in privacy, encryption and online civil rights</LI> -<LI>a VPN mailing list's<A href="http://kubarb.phsx.ukans.edu/~tbird/vpn.html"> - home page</A></LI> -</UL> -<H2><A name="newsgroups">Usenet newsgroups</A></H2> -<UL> -<LI>sci.crypt</LI> -<LI>sci.crypt.research</LI> -<LI>comp.dcom.vpn</LI> -<LI>talk.politics.crypto</LI> -</UL> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="ipsec.html">Previous</A> -<A HREF="web.html">Next</A> -</BODY> -</HTML> diff --git a/doc/makecheck.html b/doc/makecheck.html deleted file mode 100644 index e77631782..000000000 --- a/doc/makecheck.html +++ /dev/null @@ -1,523 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="umltesting.html">Previous</A> -<A HREF="nightly.html">Next</A> -<HR> -<H1><A name="makecheck">How to configure to use "make check"</A></H1> -<H2><A NAME="38_1">What is "make check"</A></H2> -<P> "make check" is a target in the top level makefile. It takes care of - running a number of unit and system tests to confirm that FreeSWAN has - been compiled correctly, and that no new bugs have been introduced.</P> -<P> As FreeSWAN contains both kernel and userspace components, doing - testing of FreeSWAN requires that the kernel be simulated. This is - typically difficult to do as a kernel requires that it be run on bare - hardware. A technology has emerged that makes this simpler. This is<A HREF="http://user-mode-linux.sourceforge.net"> - User Mode Linux</A>.</P> -<P> User-Mode Linux is a way to build a Linux kernel such that it can - run as a process under another Linux (or in the future other) kernel. - Presently, this can only be done for 2.4 guest kernels. The host kernel - can be 2.2 or 2.4.</P> -<P> "make check" expects to be able to build User-Mode Linux kernels - with FreeSWAN included. To do this it needs to have some files - downloaded and extracted prior to running "make check". This is - described in the<A HREF="umltesting.html"> UML testing</A> document.</P> -<P> After having run the example in the UML testing document and - successfully brought up the four machine combination, you are ready to - use "make check"</P> -<H2><A NAME="38_2">Running "make check"</A></H2> -<P> "make check" works by walking the FreeSWAN source tree invoking the - "check" target at each node. At present there are tests defined only - for the <CODE>klips</CODE> directory. These tests will use the UML - infrastructure to test out pieces of the <CODE>klips</CODE> code.</P> -<P> The results of the tests can be recorded. If the environment - variable <CODE>$REGRESSRESULTS</CODE> is non-null, then the results of - each test will be recorded. This can be used as part of a nightly - regression testing system, see<A HREF="nightly.html"> Nightly testing</A> - for more details.</P> -<P> "make check" otherwise prints a minimal amount of output for each - test, and indicates pass/fail status of each test as they are run. - Failed tests do not cause failure of the target in the form of exit - codes.</P> -<H1><A NAME="39">How to write a "make check" test</A></H1> -<H2><A NAME="39_1">Structure of a test</A></H2> -<P> Each test consists of a set of directories under <CODE>testing/</CODE> -. There are directories for <CODE>klips</CODE>, <CODE>pluto</CODE>, <CODE> -packaging</CODE> and <CODE>libraries</CODE>. Each directory has a list - of tests to run is stored in a file called <CODE>TESTLIST</CODE> in - that directory. e.g. <CODE>testing/klips/TESTLIST</CODE>.</P> -<H2 NAME="TESTLIST"><A NAME="39_2">The TESTLIST</A></H2> -<P> This isn't actually a shell script. It just looks like one. Some - tools other than /bin/sh process it. Lines that start with # are - comments.</P> -<PRE> -# test-kind directory-containing-test expectation [PR#] -</PRE> -<P>The first word provides the test type, detailed below.</P> -<P> The second word is the name of the test to run. This the directory - in which the test case is to be found..</P> -<P>The third word may be one of:</P> -<DL> -<DT> blank/good</DT> -<DD>the test is believed to function, report failure</DD> -<DT> bad</DT> -<DD> the test is known to fail, report unexpected success</DD> -<DT> suspended</DT> -<DD> the test should not be run</DD> -</DL> -<P> The fourth word may be a number, which is a PR# if the test is - failing.</P> -<H2><A NAME="39_3">Test kinds</A></H2> - The test types are: -<DL> -<DT>skiptest</DT> -<DD>means run no test.</DD> -<DT>ctltest</DT> -<DD>means run a single system without input/output.</DD> -<DT>klipstest</DT> -<DD>means run a single system with input/output networks</DD> -<DT><A HREF="#umlplutotest">umlplutotest</A></DT> -<DD>means run a pair of systems</DD> -<DT><A HREF="#umlXhost">umlXhost</A></DT> -<DD>run an arbitrary number of systems</DD> -<DT>suntest (TBD)</DT> -<DD>means run a quad of east/west/sunrise/sunset</DD> -<DT>roadtest (TBD)</DT> -<DD>means run a trio of east-sunrise + warrior</DD> -<DT>extrudedtest (TBD)</DT> -<DD>means run a quad of east-sunrise + warriorsouth + park</DD> -<DT>mkinsttest</DT> -<DD>a test of the "make install" machinery.</DD> -<DT>kernel_test_patch</DT> -<DD>a test of the "make kernelpatch" machinery.</DD> -</DL> - Tests marked (TBD) have yet to be fully defined. -<P> Each test directory has a file in it called <CODE>testparams.sh</CODE> -. This file sets a number of environment variables to define the - parameters of the test.</P> -<H2><A NAME="39_4">Common parameters</A></H2> -<DL> -<DT>TESTNAME</DT> -<DD>the name of the test (repeated for checking purposes)</DD> -<DT>TEST_TYPE</DT> -<DD>the type of the test (repeat of type type above)</DD> -<DT>TESTHOST</DT> -<DD>the name of the UML machine to run for the test, typically "east" or - "west"</DD> -<DT>TEST_PURPOSE</DT> -<DD>The purpose of the test is one of: -<DL> -<DT>goal</DT> -<DD>The goal purpose is where a test is defined for code that is not yet - finished. The test indicates when the goals have in fact been reached.</DD> -<DT>regress</DT> -<DD>This is a test to determine that a previously existing bug has been - repaired. This test will initially be created to reproduce the bug in - isolation, and then the bug will be fixed.</DD> -<DT>exploit</DT> -<DD>This is a set of packets/programs that causes a vulnerability to be - exposed. It is a specific variation of the regress option.</DD> -</DL> -</DD> -<DT>TEST_GOAL_ITEM</DT> -<DT></DT> -<DD>in the case of a goal test, this is a reference to the requirements - document</DD> -<DT>TEST_PROB_REPORT</DT> -<DD>in the case of regression test, this the problem report number from - GNATS</DD> -<DT>TEST_EXPLOIT_URL</DT> -<DD>in the case of an exploit, this is a URL referencing the paper - explaining the origin of the test and the origin of exploit software</DD> -<DT>REF_CONSOLE_OUTPUT</DT> -<DD>a file in the test directory that contains the sanitized console - output against which to compare the output of the actual test.</DD> -<DT>REF_CONSOLE_FIXUPS</DT> -<DD>a list of scripts (found in <CODE>klips/test/fixups</CODE>) to apply - to sanitize the console output of the machine under test. These are - typically perl, awk or sed scripts that remove things in the kernel - output that change each time the test is run and/or compiled.</DD> -<DT>INIT_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode prior to starting the tests. This file will usually - set up any eroute's and SADB entries that are required for the test.</P> -<P>Lines beginning with # are skipped. Blank lines are skipped. - Otherwise, a shell prompted is waited for each time (consisting of <CODE> -\n#</CODE>) and then the command is sent. Note that the prompt is waited - for before the command and not after, so completion of the last command - in the script is not required. This is often used to invoke a program - to monitor the system, e.g. <CODE>ipsec pf_key</CODE>.</P> -</DD> -<DT>RUN_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode, before the packets are sent. On single machine tests, - this script doesn't provide any more power than INIT_SCRIPT, but is - implemented for consistency's sake.</P> -</DD> -<DT>FINAL_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode after the final packet is sent. Similar to - INIT_SCRIPT, above. If not specified, then the single command "halt" is - sent. If specified, then the script should end with a halt command to - nicely shutdown the UML.</P> -</DD> -<DT>CONSOLEDIFFDEBUG</DT> -<DD>If set to "true" then the series of console fixups (see - REF_CONSOLE_FIXUPS) will be output after it is constructed. (It should - be set to "false", or unset otherwise)</DD> -<DT>NETJIGDEBUG</DT> -<DD>If set to "true" then the series of console fixups (see - REF_CONSOLE_FIXUPS) will be output after it is constructed. (It should - be set to "false", or unset otherwise)</DD> -<DT>NETJIGTESTDEBUG</DT> -<DD> If set to "netjig", then the results of talking to the <CODE> -uml_netjig</CODE> will be printed to stderr during the test. In - addition, the jig will be invoked with --debug, which causes it to log - its process ID, and wait 60 seconds before continuing. This can be used - if you are trying to debug the <CODE>uml_netjig</CODE> program itself.</DD> -<DT>HOSTTESTDEBUG</DT> -<DD> If set to "hosttest", then the results of taling to the consoles of - the UMLs will be printed to stderr during the test.</DD> -<DT>NETJIGWAITUSER</DT> -<DD> If set to "waituser", then the scripts will wait forever for user - input before they shut the tests down. Use this is if you are debugging - through the kernel.</DD> -<DT>PACKETRATE</DT> -<DD> A number, in miliseconds (default is 500ms) at which packets will - be replayed by the netjig.</DD> -</DL> -<H2><A NAME="39_5">KLIPStest paramaters</A></H2> -<P> The klipstest function starts a program (<CODE> -testing/utils/uml_netjig/uml_netjig</CODE>) to setup a bunch of I/O - sockets (that simulate network interfaces). It then exports the - references to these sockets to the environment and invokes (using - system()) a given script. It waits for the script to finish.</P> - -<!-- <IMG SRC="single_netjig.png" ALT="block diagram of uml_netjig"> --> -<P> The script invoked (<CODE>testing/utils/host-test.tcl</CODE>) is a - TCL<A HREF="http://expect.nist.gov/"> expect</A> script that arranges - to start the UML and configure it appropriately for the test. The - configuration is done with the script given above for<VAR> INIT_SCRIPT</VAR> -. The TCL script then forks, leaves the UML in the background and exits. - uml_netjig continues. It then starts listening to the simulated network - answering ARPs and inserting packets as appropriate.</P> -<P> The klipstest function invokes <CODE>uml_netjig</CODE> with - arguments to capture output from network interface(s) and insert - packets as appropriate:</P> -<DL> -<DT>PUB_INPUT</DT> -<DD>a<A HREF="http://www.tcpdump.org/"> pcap</A> file to feed in on the - public (encrypted) interface. (typically, eth1)</DD> -<DT>PRIV_INPUT</DT> -<DD>a pcap file to feed in on the private (plain-text) interface - (typically, eth0).</DD> -<DT>REF_PUB_OUTPUT</DT> -<DD>a text file containing tcpdump output. Packets on the public (eth1) - interface are captured to a<A HREF="http://www.tcpdump.org/"> pcap</A> - file by <CODE>uml_netjig</CODE>. The klipstest function then uses - tcpdump on the file to produce text output, which is compared to the - file given.</DD> -<DT>REF_PUB_FILTER</DT> -<DD>a program that will filter the TCPDUMP output to do further - processing. Defaults to "cat".</DD> -<DT>REF_PRIV_OUTPUT</DT> -<DD>a text file containing tcpdump output. Packets on the private (eth0) - interface are captured and compared after conversion by tcpdump, as - with<VAR> REFPUBOUTPUT</VAR>.</DD> -<DT>REF_PRIV_FILTER</DT> -<DD>a program that will filter the TCPDUMP output to do further - processing. Defaults to "cat".</DD> -<DT>EXITONEMPTY</DT> -<DD>a flag for <CODE>uml_netjig</CODE>. It should contain - "--exitonempty" of uml_netjig should exit when all of the input (<VAR> -PUBINPUT</VAR>,<VAR>PRIVINPUT</VAR>) packets have been injected.</DD> -<DT>ARPREPLY</DT> -<DD>a flag for <CODE>uml_netjig</CODE>. It should contain "--arpreply" - if <CODE>uml_netjig</CODE> should reply to ARP requests. One will - typically set this to avoid having to fudge the ARP cache manually.</DD> -<DT>TCPDUMPFLAGS</DT> -<DD>a set of flags for the tcpdump used when converting captured output. - Typical values will include "-n" to turn off DNS, and often "-E" to set - the decryption key (tcpdump 3.7.1 and higher only) for ESP packets. The - "-t" flag (turn off timestamps) is provided automatically</DD> -<DT>NETJIG_EXTRA</DT> -<DD>additional comments to be sent to the netjig. This may arrange to - record or create additional networks, or may toggle options.</DD> -</DL> -<H2><A NAME="39_6">mkinsttest paramaters</A></H2> -<P> The basic concept of the <CODE>mkinsttest</CODE> test type is that - it performs a "make install" to a temporary $DESTDIR. The resulting - tree can then be examined to determine if it was done properly. The - files can be uninstalled to determine if the file list was correct, or - the contents of files can be examined more precisely.</P> -<DL> -<DT>INSTALL_FLAGS</DT> -<DD>If set, then an install will be done. This provides the set of flags - to provide for the install. The target to be used (usually "install") - must be among the flags.</DD> -<DT>POSTINSTALL_SCRIPT</DT> -<DD>If set, a script to run after initial "make install". Two arguments - are provided: an absolute path to the root of the FreeSWAN src tree, - and an absolute path to the temporary installation area.</DD> -<DT>INSTALL2_FLAGS</DT> -<DD>If set, a second install will be done using these flags. Similarly - to INSTALL_FLAGS, the target must be among the flags.</DD> -<DT>UNINSTALL_FLAGS</DT> -<DD>If set, an uninstall will be done using these flags. Similarly to - INSTALL_FLAGS, the target (usually "uninstall") must be among the - flags.</DD> -<DT>REF_FIND_f_l_OUTPUT</DT> -<DD>If set, a <CODE>find $ROOT ( -type f -or -type -l )</CODE> will be - done to get a list of a real files and symlinks. The resulting file - will be compared to the file listed by this option.</DD> -<DT>REF_FILE_CONTENTS</DT> -<DD>If set, it should point to a file containing records for the form: -<PRE> - -<!--VARIABLE--> -reffile</(null)> -<!--VARIABLE--> -samplefile</(null)> -</PRE> - one record per line. A diff between the provided reference file, and - the sample file (located in the temporary installation root) will be - done for each record.</DD> -</DL> -<H2><A NAME="39_7">rpm_build_install_test paramaters</A></H2> -<P> The <CODE>rpm_build_install_test</CODE> type is to verify that the - proper packing list is produced by "make rpm", and that the mechanisms - for building the kernel modules produce consistent results.</P> -<DL> -<DT>RPM_KERNEL_SOURCE</DT> -<DD>Point to an extracted copy of the RedHat kernel source code. - Variables from the environment may be used.</DD> -<DT>REF_RPM_CONTENTS</DT> -<DD>This is a file containing one record per line. Each record consists - of a RPM name (may contain wildcards) and a filename to compare the - contents to. The RPM will be located and a file list will be produced - with rpm2cpio.</DD> -</DL> -<H2><A NAME="39_8">libtest paramaters</A></H2> -<P> The libtest test is for testing library routines. The library file - is expected to provided an <CODE>#ifdef</CODE> by the name of<VAR> - library</VAR> -<!--CODE_MAIN</CODE--> -. The libtest type invokes the C compiler to compile this - file, links it against <CODE>libfreeswan.a</CODE> (to resolve any other - dependancies) and runs the test with the <CODE>-r</CODE> argument to - invoke a regression test.</(null)></P> -<P>The library test case is expected to do a self-test, exiting with - status code 0 if everything is okay, and with non-zero otherwise. A - core dump (exit code greater than 128) is noted specifically.</P> -<P> Unlike other tests, there are no subdirectories required, or other - parameters to set.</P> -<H2 NAME="umlplutotest"><A NAME="39_9">umlplutotest paramaters</A></H2> -<P> The umlplutotest function starts a pair of user mode line processes. - This is a 2-host version of umlXhost. The "EAST" and "WEST" slots are - defined.</P> -<H2 NAME="umlXhost"><A NAME="39_10">umlXhost parameters</A></H2> -<P> The umlXtest function starts an arbitrary number of user mode line - processes.</P> - -<!-- <IMG SRC="single_netjig.png" ALT="block diagram of uml_netjig"> --> -<P> The script invoked (<CODE>testing/utils/Xhost-test.tcl</CODE>) is a - TCL<A HREF="http://expect.nist.gov/"> expect</A> script that arranges - to start each UML and configure it appropriately for the test. It then - starts listening (using uml_netjig) to the simulated network answering - ARPs and inserting packets as appropriate.</P> -<P> umlXtest has a series of slots, each of which should be filled by a - host. The list of slots is controlled by the variable, XHOST_LIST. This - variable should be set to a space seperated list of slots. The former - umlplutotest is now implemented as a variation of the umlXhost test, - with XHOST_LIST="EAST WEST".</P> -<P> For each host slot that is defined, a series of variables should be - filled in, defining what configuration scripts to use for that host.</P> -<P> The following are used to control the console input and output to - the system. Where the string ${host} is present, the host slot should - be filled in. I.e. for the two host system with XHOST_LIST="EAST WEST", - then the variables: EAST_INIT_SCRIPT and WEST_INIT_SCRIPT will exist.</P> -<DL> -<DT>${host}HOST</DT> -<DD>The name of the UML host which will fill this slot</DD> -<DT>${host}_INIT_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode prior to starting the tests. This file will usually - set up any eroute's and SADB entries that are required for the test. - Similar to INIT_SCRIPT, above.</P> -</DD> -<DT>${host}_RUN_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode, before the packets are sent. This set of commands is - run after all of the virtual machines are initialized. I.e. after - EAST_INIT_SCRIPT<B> AND</B> WEST_INIT_SCRIPT. This script can therefore - do things that require that all machines are properly configured.</P> -</DD> -<DT>${host}_RUN2_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode, after the packets are sent. This set of commands is - run before any of the virtual machines have been shut down. (I.e. - before EAST_FINAL_SCRIPT<B> AND</B> WEST_FINAL_SCRIPT.) This script can - therefore catch post-activity status reports.</P> -</DD> -<DT>${host}_FINAL_SCRIPT</DT> -<DD> -<P>a file of commands that is fed into the virtual machine's console in - single user mode after the final packet is sent. Similar to - INIT_SCRIPT, above. If not specified, then the single command "halt" is - sent. Note that when this script is run, the other virtual machines may - already have been killed. If specified, then the script should end with - a halt command to nicely shutdown the UML.</P> -</DD> -<DT>REF_${host}_CONSOLE_OUTPUT</DT> -<DD>Similar to REF_CONSOLE_OUTPUT, above.</DD> -</DL> -<P>Some additional flags apply to all hosts:</P> -<DL> -<DT>REF_CONSOLE_FIXUPS</DT> -<DD>a list of scripts (found in <CODE>klips/test/fixups</CODE>) to apply - to sanitize the console output of the machine under test. These are - typically perl, awk or sed scripts that remove things in the kernel - output that change each time the test is run and/or compiled.</DD> -</DL> -<P> In addition to input to the console, the networks may have input fed - to them:</P> -<DL> -<DT>EAST_INPUT/WEST_INPUT</DT> -<DD>a<A HREF="http://www.tcpdump.org/"> pcap</A> file to feed in on the - private network side of each network. The "EAST" and "WEST" here refer - to the networks, not the hosts.</DD> -<DT>REF_PUB_FILTER</DT> -<DD>a program that will filter the TCPDUMP output to do further - processing. Defaults to "cat".</DD> -<DT>REF_EAST_FILTER/REF_WEST_FILTER</DT> -<DD>a program that will filter the TCPDUMP output to do further - processing. Defaults to "cat".</DD> -< -<DT>TCPDUMPFLAGS</DT> -<DD>a set of flags for the tcpdump used when converting captured output. - Typical values will include "-n" to turn off DNS, and often "-E" to set - the decryption key (tcpdump 3.7.1 and higher only) for ESP packets. The - "-t" flag (turn off timestamps) is provided automatically</DD> -<DT>REF_EAST_OUTPUT/REF_WEST_OUTPUT</DT> -<DD>a text file containing tcpdump output. Packets on the private (eth0) - interface are captured and compared after conversion by tcpdump, as - with<VAR> REF_PUB_OUTPUT</VAR>.</DD> -<P> There are two additional environment variables that may be set on - the command line:</P> -<DL> -<DT> NETJIGVERBOSE=verbose export NETJIGVERBOSE</DT> -<DD> If set, then the test output will be "chatty", and let you know - what commands it is running, and as packets are sent. Without it set, - the output is limited to success/failure messages.</DD> -<DT> NETJIGTESTDEBUG=netjig export NETJIGTESTDEBUG</DT> -<DD> This will enable debugging of the communication with uml_netjig, - and turn on debugging in this utility. This does not imply - NETJIGVERBOSE.</DD> -</DL> -<DT> HOSTTESTDEBUG=hosttest export HOSTTESTDEBUG</DT> -<DD> This will show all interactions with the user-mode-linux consoles</DD> -</DL> -<H2 NAME="kernelpatch"><A NAME="39_11">kernel_patch_test paramaters</A></H2> -<P> The kernel_patch_test function takes some kernel source, copies it - with lndir, and then applies the patch as produced by "make - kernelpatch".</P> -<P> The following are used to control the input and output to the - system:</P> -<DL> -<DT>KERNEL_NAME</DT> -<DD>the kernel name, typically something like "linus" or "rh"</DD> -<DT>KERNEL_VERSION</DT> -<DD>the kernel version number, as in "2.2" or "2.4".</DD> -<DT>KERNEL_${KERNEL_NAME}${KERNEL_VERSION}_SRC</DT> -<DD>This variable should set in the environment, probably in - ~/freeswan-regress-env.sh. Examples of this variables would be - KERNEL_LINUS2_0_SRC or KERNEL_RH7_3_SRC. This variable should point to - an extracted copy of the kernel source in question.</DD> -<DT>REF_PATCH_OUTPUT</DT> -<DD>a copy of the patch output to compare against</DD> -<DT>KERNEL_PATCH_LEAVE_SOURCE</DT> -<DD>If set to a non-empty string, then the patched kernel source is not - removed at the end of the test. This will typically be set in the - environment while debugging.</DD> -</DL> -<H2 NAME="modtest"><A NAME="39_12">module_compile paramaters</A></H2> -<P> The module_compile test attempts to build the KLIPS module against a - given set of kernel source. This is also done by the RPM tests, but in - a very specific manner.</P> -<P> There are two variations of this test - one where the kernel either - doesn't need to be configured, or is already done, and tests were there - is a local configuration file.</P> -<P> Where the kernel doesn't need to be configured, the kernel source - that is found is simply used. It may be a RedHat-style kernel, where - one can cause it to configure itself via rhconfig.h-style definitions. - Or, it may just be a kernel tree that has been configured.</P> -<P> If the variable KERNEL_CONFIG_FILE is set, then a new directory is - created for the kernel source. It is populated with lndir(1). The - referenced file is then copied in as .config, and "make oldconfig" is - used to configure the kernel. This resulting kernel is then used as the - reference source.</P> -<P> In all cases, the kernel source is found the same was for the - kernelpatch test, i.e. via KERNEL_VERSION/KERNEL_NAME and - KERNEL_${KERNEL_NAME}${KERNEL_VERSION}_SRC.</P> -<P> Once there is kernel source, the module is compiled using the - top-level "make module" target.</P> -<P> The test is considered successful if an executable is found in - OUTPUT/module/ipsec.o at the end of the test.</P> -<DL> -<DT>KERNEL_NAME</DT> -<DD>the kernel name, typically something like "linus" or "rh"</DD> -<DT>KERNEL_VERSION</DT> -<DD>the kernel version number, as in "2.2" or "2.4".</DD> -<DT>KERNEL_${KERNEL_NAME}${KERNEL_VERSION}_SRC</DT> -<DD>This variable should set in the environment, probably in - ~/freeswan-regress-env.sh. Examples of this variables would be - KERNEL_LINUS2_0_SRC or KERNEL_RH7_3_SRC. This variable should point to - an extracted copy of the kernel source in question.</DD> -<DT>KERNEL_CONFIG_FILE</DT> -<DD>The configuration file for the kernel.</DD> -<DT>KERNEL_PATCH_LEAVE_SOURCE</DT> -<DD>If set to a non-empty string, then the configured kernel source is - not removed at the end of the test. This will typically be set in the - environment while debugging.</DD> -<DT>MODULE_DEF_INCLUDE</DT> -<DD>The include file that will be used to configure the KLIPS module, - and possibly the kernel source.</DD> -</DL> -<H1><A NAME="40">Current pitfalls</A></H1> -<DL> -<DT> "tcpdump dissector" not available.</DT> -<DD> This is a non-fatal warning. If uml_netjig is invoked with the -t - option, then it will attempt to use tcpdump's dissector to decode each - packet that it processes. The dissector is presently not available, so - this option it normally turned off at compile time. The dissector - library will be released with tcpdump version 4.0.</DD> -</DL> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="umltesting.html">Previous</A> -<A HREF="nightly.html">Next</A> -</BODY> -</HTML> diff --git a/doc/manpages.html b/doc/manpages.html deleted file mode 100644 index 81ca11ae0..000000000 --- a/doc/manpages.html +++ /dev/null @@ -1,145 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="faq.html">Previous</A> -<A HREF="firewall.html">Next</A> -<HR> -<H1><A name="manpages">FreeS/WAN manual pages</A></H1> -<P>The various components of Linux FreeS/WAN are of course documented in - standard Unix manual pages, accessible via the man(1) command.</P> -<P>Links here take you to an HTML version of the man pages.</P> -<H2><A name="man.file">Files</A></H2> -<DL> -<DT><A href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</A></DT> -<DD>IPsec configuration and connections</DD> -<DT><A href="manpage.d/ipsec.secrets.5.html">ipsec.secrets(5)</A></DT> -<DD>secrets for IKE authentication, either pre-shared keys or RSA - private keys</DD> -</DL> -<P>These files are also discussed in the<A href="config.html"> - configuration</A> section.</P> -<H2><A name="man.command">Commands</A></H2> -<P>Many users will never give most of the FreeS/WAN commands directly. - Configure the files listed above correctly and everything should be - automatic.</P> -<P>The exceptions are commands for mainpulating the<A href="glossary.html#RSA"> - RSA</A> keys used in Pluto authentication:</P> -<DL> -<DT><A href="manpage.d/ipsec_rsasigkey.8.html">ipsec_rsasigkey(8)</A></DT> -<DD>generate keys</DD> -<DT><A href="manpage.d/ipsec_newhostkey.8.html">ipsec_newhostkey(8)</A></DT> -<DD>generate keys in a convenient format</DD> -<DT><A href="manpage.d/ipsec_showhostkey.8.html">ipsec_showhostkey(8)</A> -</DT> -<DD>extract<A href="glossary.html#RSA"> RSA</A> keys from<A href="manpage.d/ipsec.secrets.5.html"> - ipsec.secrets(5)</A> (or optionally, another file) and format them for - insertion in<A href="manpage.d/ipsec.conf.5.html"> ipsec.conf(5)</A> or - in DNS records</DD> -</DL> -<P>Note that:</P> -<UL> -<LI>These keys are for<STRONG> authentication only</STRONG>. They are<STRONG> - not secure for encryption</STRONG>.</LI> -<LI>The utility uses random(4) as a source of<A href="glossary.html#random"> - random numbers</A>. This may block for some time if there is not enough - activity on the machine to provide the required entropy. You may want - to give it some bogus activity such as random mouse movements or some - command such as<NOBR> <TT>du /usr > /dev/null &</TT>.</LI> -</UL> -<P>The following commands are fairly likely to be used, if only for - testing and status checks:</P> -<DL> -<DT><A href="manpage.d/ipsec.8.html">ipsec(8)</A></DT> -<DD>invoke IPsec utilities</DD> -<DT><A href="manpage.d/ipsec_setup.8.html">ipsec_setup(8)</A></DT> -<DD>control IPsec subsystem</DD> -<DT><A href="manpage.d/ipsec_auto.8.html">ipsec_auto(8)</A></DT> -<DD>control automatically-keyed IPsec connections</DD> -<DT><A href="manpage.d/ipsec_manual.8.html">ipsec_manual(8)</A></DT> -<DD>take manually-keyed IPsec connections up and down</DD> -<DT><A href="manpage.d/ipsec_ranbits.8.html">ipsec_ranbits(8)</A></DT> -<DD>generate random bits in ASCII form</DD> -<DT><A href="manpage.d/ipsec_look.8.html">ipsec_look(8)</A></DT> -<DD>show minimal debugging information</DD> -<DT><A href="manpage.d/ipsec_barf.8.html">ipsec_barf(8)</A></DT> -<DD>spew out collected IPsec debugging information</DD> -</DL> -<P>The lower-level utilities listed below are normally invoked via - scripts listed above, but they can also be used directly when required.</P> -<DL> -<DT><A href="manpage.d/ipsec_eroute.8.html">ipsec_eroute(8)</A></DT> -<DD>manipulate IPsec extended routing tables</DD> -<DT><A href="manpage.d/ipsec_klipsdebug.8.html">ipsec_klipsdebug(8)</A></DT> -<DD>set Klips (kernel IPsec support) debug features and level</DD> -<DT><A href="manpage.d/ipsec_pluto.8.html">ipsec_pluto(8)</A></DT> -<DD>IPsec IKE keying daemon</DD> -<DT><A href="manpage.d/ipsec_spi.8.html">ipsec_spi(8)</A></DT> -<DD>manage IPsec Security Associations</DD> -<DT><A href="manpage.d/ipsec_spigrp.8.html">ipsec_spigrp(8)</A></DT> -<DD>group/ungroup IPsec Security Associations</DD> -<DT><A href="manpage.d/ipsec_tncfg.8.html">ipsec_tncfg(8)</A></DT> -<DD>associate IPsec virtual interface with real interface</DD> -<DT><A href="manpage.d/ipsec_whack.8.html">ipsec_whack(8)</A></DT> -<DD>control interface for IPsec keying daemon</DD> -</DL> -<H2><A name="man.lib">Library routines</A></H2> -<DL> -<DT><A href="manpage.d/ipsec_atoaddr.3.html">ipsec_atoaddr(3)</A></DT> -<DT><A href="manpage.d/ipsec_addrtoa.3.html">ipsec_addrtoa(3)</A></DT> -<DD>convert Internet addresses to and from ASCII</DD> -<DT><A href="manpage.d/ipsec_atosubnet.3.html">ipsec_atosubnet(3)</A></DT> -<DT><A href="manpage.d/ipsec_subnettoa.3.html">ipsec_subnettoa(3)</A></DT> -<DD>convert subnet/mask ASCII form to and from addresses</DD> -<DT><A href="manpage.d/ipsec_atoasr.3.html">ipsec_atoasr(3)</A></DT> -<DD>convert ASCII to Internet address, subnet, or range</DD> -<DT><A href="manpage.d/ipsec_rangetoa.3.html">ipsec_rangetoa(3)</A></DT> -<DD>convert Internet address range to ASCII</DD> -<DT>ipsec_atodata(3)</DT> -<DT><A href="manpage.d/ipsec_datatoa.3.html">ipsec_datatoa(3)</A></DT> -<DD>convert binary data from and to ASCII formats</DD> -<DT><A href="manpage.d/ipsec_atosa.3.html">ipsec_atosa(3)</A></DT> -<DT><A href="manpage.d/ipsec_satoa.3.html">ipsec_satoa(3)</A></DT> -<DD>convert IPsec Security Association IDs to and from ASCII</DD> -<DT><A href="manpage.d/ipsec_atoul.3.html">ipsec_atoul(3)</A></DT> -<DT><A href="manpage.d/ipsec_ultoa.3.html">ipsec_ultoa(3)</A></DT> -<DD>convert unsigned-long numbers to and from ASCII</DD> -<DT><A href="manpage.d/ipsec_goodmask.3.html">ipsec_goodmask(3)</A></DT> -<DD>is this Internet subnet mask a valid one?</DD> -<DT><A href="manpage.d/ipsec_masktobits.3.html">ipsec_masktobits(3)</A></DT> -<DD>convert Internet subnet mask to bit count</DD> -<DT><A href="manpage.d/ipsec_bitstomask.3.html">ipsec_bitstomask(3)</A></DT> -<DD>convert bit count to Internet subnet mask</DD> -<DT><A href="manpage.d/ipsec_optionsfrom.3.html">ipsec_optionsfrom(3)</A> -</DT> -<DD>read additional ``command-line'' options from file</DD> -<DT><A href="manpage.d/ipsec_subnetof.3.html">ipsec_subnetof(3)</A></DT> -<DD>given Internet address and subnet mask, return subnet number</DD> -<DT><A href="manpage.d/ipsec_hostof.3.html">ipsec_hostof(3)</A></DT> -<DD>given Internet address and subnet mask, return host part</DD> -<DT><A href="manpage.d/ipsec_broadcastof.3.html">ipsec_broadcastof(3)</A> -</DT> -<DD>given Internet address and subnet mask, return broadcast address</DD> -</DL> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="faq.html">Previous</A> -<A HREF="firewall.html">Next</A> -</BODY> -</HTML> diff --git a/doc/nightly.html b/doc/nightly.html deleted file mode 100644 index 580fc0fc5..000000000 --- a/doc/nightly.html +++ /dev/null @@ -1,125 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="makecheck.html">Previous</A> -<HR> -<H1><A name="nightly">Nightly regression testing</A></H1> -<P> The nightly regression testing system consists of several shell - scripts and some perl scripts. The goal is to check out a fresh tree, - run "make check" on it, record the results and summarize the results to - the team and to the web site.</P> -<P> Output can be found on<A HREF="http://bugs.freeswan.org:81/"> adams</A> -, although the tests are actually run on another project machine.</P> -<H1><A name="nightlyhowto">How to setup the nightly build</A></H1> -<P> The best way to do nightly testing is to setup a new account. We - call the account "build" - you could call it something else, but there - may still be some references to ~build in the scripts.</P> -<H2><A NAME="42_1"> Files you need to know about</A></H2> -<P> As few files as possible need to be extracted from the source tree - - files are run from the source tree whenever possible. However, there - are some bootstrap and configuration files that are necessary.</P> -<P> There are 7 files in testing/utils that are involved:</P> -<DL> -<DT> nightly-sample.sh</DT> -<DD> This is the root of the build process. This file should be copied - out of the CVS tree, to $HOME/bin/nightly.sh of the build account. This - file should be invoked from cron.</DD> -<DT> freeswan-regress-env-sample.sh</DT> -<DD> This file should be copied to $HOME/freeswan-regress-env.sh. It - should be edited to localize the values. See below.</DD> -<DT> regress-cleanup.pl</DT> -<DD> This file needs to be copied to $HOME/bin/regress-cleanup.pl. It is - invoked by the nightly file before doing anything else. It removes - previous nights builds in order to free up disk space for the build - about to be done.</DD> -<DT> teammail-sample.sh</DT> -<DD> A script used to send results email to the "team". This sample - script could be copied to $HOME/bin/teammail.sh. This version will PGP - encrypt all the output to the team members. If this script is used, - then PGP will have to be properly setup to have the right keys.</DD> -<DT> regress-nightly.sh</DT> -<DD> This is the first stage of the nightly build. This stage will call - other scripts as appropriate, and will extract the source code from - CVS. This script should be copied to $HOME/bin/regress-nightly.sh</DD> -<DT> regress-stage2.sh</DT> -<DD> This is the second stage of the nightly build. It is called in - place. It essentially sets up the UML setup in umlsetup.sh, and calls - "make check".</DD> -<DT> regress-summarize-results.pl</DT> -<DD> This script will summarize the results from the tests to a - permanent directory set by $REGRESSRESULTS. It is invoked from the - stage2 nightly script.</DD> -<DT> regress-chart.sh</DT> -<DD> This script is called at the end of the build process, and will - summarize each night's results (as saved into $REGRESSRESULTS by - regress-summarize-results.pl) as a chart using gnuplot. Note that this - requires at least gnuplot 3.7.2.</DD> -</DL> -<H2><A NAME="42_2">Configuring freeswan-regress-env.sh</A></H2> -<P>For more info on KERNPOOL, UMLPATCH, BASICROOT and SHAREDIR, see<A HREF="umltesting.html"> - User-Mode-Linux testing guide</A>.</P> -<DL> -<DT> KERNPOOL</DT> -<DD> Extract copy of some kernel source to be used for UML builds</DD> -<DT> UMLPATCH</DT> -<DD> matching User-Mode-Linux patch.</DD> -<DT> BASICROOT</DT> -<DD> the root file system image (see<A HREF="umltesting.html"> - User-Mode-Linux testing guide</A>).</DD> -<DT> SHAREDIR=${BASICROOT}/usr/share</DT> -<DD> The /usr/share to use.</DD> -<DT> REGRESSTREE</DT> -<DD> A directory in which to store the nightly regression results. - Directories will be created by date in this tree.</DD> -<DT> TCPDUMP=tcpdump-3.7.1</DT> -<DD> The path to the<A HREF="http://www.tcpdump.org/"> tcpdump</A> to - use. This must have crypto compiled in, and must be at least 3.7.1</DD> -<DT> KERNEL_RH7_2_SRC=/a3/kernel_sources/linux-2.4.9-13/</DT> -<DD> An extracted copy of the RedHat 7.2. kernel source. If set, then - the packaging/rpm-rh72-install-01 test will be run, and an RPM will be - built as a test.</DD> -<DT> KERNEL_RH7_3_SRC=/a3/kernel_sources/rh/linux-2.4.18-5</DT> -<DD> An extracted copy of the RedHat 7.3. kernel source. If set, then - the packaging/rpm-rh73-install-01 test will be run, and an RPM will be - built as a test.</DD> -<DT> NIGHTLY_WATCHERS="userid,userid,userid"</DT> -<DD> The list of people who should receive nightly output. This is used - by teammail.sh</DD> -<DT> FAILLINES=128</DT> -<DD> How many lines of failed test output to include in the nightly - output</DD> -<DT> PATH=$PATH:/sandel/bin export PATH</DT> -<DD> You can also override the path if necessary here.</DD> -<DT> CVSROOT=:pserver:anoncvs@ip212.xs4net.freeswan.org:/freeswan/MASTER</DT> -<DD> The CVSROOT to use. This example may work for anonymous CVS, but - will be 12 hours behind the primary, and is still experimental</DD> -<DT> SNAPSHOTSIGDIR=$HOME/snapshot-sig</DT> -<DD> For the release tools, where to put the generated per-snapshot - signature keys</DD> -<DT> LASTREL=1.97</DT> -<DD> the name of the last release branch (to find the right per-snapshot - signature</DD> -<DD></DD> -</DL> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="makecheck.html">Previous</A> -</BODY> -</HTML> diff --git a/doc/oppimpl.txt b/doc/oppimpl.txt deleted file mode 100644 index fe4527d4e..000000000 --- a/doc/oppimpl.txt +++ /dev/null @@ -1,514 +0,0 @@ -Implementing Opportunistic Encryption - -Henry Spencer & D. Hugh Redelmeier - -Version 4+, 15 Dec 2000 - - - -Updates - -Major changes since last version: "Negotiation Issues" section discussing -some interoperability matters, plus some wording cleanup. Some issues -arising from discussions at OLS are not yet resolved, so there will almost -certainly be another version soon. - -xxx incoming could be opportunistic or RW. xxx any way of saving unaware -implementations??? xxx compression needs mention. - - - -Introduction - -A major long-term goal of the FreeS/WAN project is opportunistic -encryption: a security gateway intercepts an outgoing packet aimed at a -new remote host, and quickly attempts to negotiate an IPsec tunnel to that -host's security gateway, so that traffic can be encrypted and -authenticated without changes to the host software. (This generalizes -trivially to the end-to-end case where host and security gateway are one -and the same.) If the attempt fails, the packet (or a retry thereof) -passes through in clear or is dropped, depending on local policy. -Prearranged tunnels bypass all this, so static VPNs can coexist with -opportunistic encryption. - -xxx here Although significant intelligence about all this is necessary at the -initiator end, it's highly desirable for little or no special machinery -to be needed at the responder end. In particular, if none were needed, -then a security gateway which knows nothing about opportunistic encryption -could nevertheless participate in some opportunistic connections. - -IPSEC gives us the low-level mechanisms, and the key-exchange machinery, -but there are some vague spots (to put it mildly) at higher levels. - -One constraint which deserves comment is that the process of tunnel setup -should be quick. Moreover, the decision that no tunnel can be created -should also be quick, since that will be a common case, at least in the -beginning. People will be reluctant to use opportunistic encryption if it -causes gross startup delays on every connection, even connections which see -no benefit from it. Win or lose, the process must be rapid. - -There's nothing much we can do to speed up the key exchange itself. (The -one thing which conceivably might be done is to use Aggressive Mode, which -involves fewer round trips, but it has limitations and possible security -problems, and we're reluctant to touch it.) What we can do, is to make the -other parts of the setup process as quick as possible. This desire will -come back to haunt us below. :-) - -A further note is that we must consider the processing at the responder -end as well as the initiator end. - -Several pieces of new machinery are needed to make this work. Here's a -brief list, with details considered below. - -+ Outgoing Packet Interception. KLIPS needs to intercept packets which -likely would benefit from tunnel setup, and bring them to Pluto's -attention. There needs to be enough memory in the process that the same -tunnel doesn't get proposed too often (win or lose). - -+ Smart Connection Management. Not only do we need to establish tunnels -on request, once a tunnel is set up, it needs to be torn down eventually -if it's not in use. It's also highly desirable to detect the fact that it -has stopped working, and do something useful. Status changes should be -coordinated between the two security gateways unless one has crashed, -and even then, they should get back into sync eventually. - -+ Security Gateway Discovery. Given a packet destination, we must decide -who to attempt to negotiate a tunnel with. This must be done quickly, win -or lose, and reliably even in the presence of diverse network setups. - -+ Authentication Without Prearrangement. We need to be sure we're really -talking to the intended security gateway, without being able to prearrange -any shared information. He needs the same assurance about us. - -+ More Flexible Policy. In particular, the responding Pluto needs a way -to figure out whether the connection it is being asked to make is okay. -This isn't as simple as just searching our existing conn database -- we -probably have to specify *classes* of legitimate connections. - -Conveniently, we have a three-letter acronym for each of these. :-) - -Note on philosophy: we have deliberately avoided providing six different -ways to do each step, in favor of specifying one good one. Choices are -provided only when they appear to be necessary. (Or when we are not yet -quite sure yet how best to do something...) - - - -OPI, SCM - -Smart Connection Management would be quite useful even by itself, -requiring manual triggering. (Right now, we do the manual triggering, but -not the other parts of SCM.) Outgoing Packet Interception fits together -with SCM quite well, and improves its usefulness further. Going through a -connection's life cycle from the start... - -OPI itself is relatively straightforward, aside from the nagging question -of whether the intercepted packet is put on hold and then released, or -dropped. Putting it on hold is preferable; the alternative is to rely on -the application or the transport layer re-trying. The downside of packet -hold is extra resources; the downside of packet dropping is that IPSEC -knows *when* the packet can finally go out, and the higher layers don't. -Either way, life gets a little tricky because a quickly-retrying -application may try more than once before we know for sure whether a -tunnel can be set up, and something has to detect and filter out the -duplications. Some ARP implementations use the approach of keeping one -packet for an as-yet-unresolved address, and throwing away any more that -appear; that seems a reasonable choice. - -(Is it worth intercepting *incoming* packets, from the outside world, and -attempting tunnel setup based on them? Perhaps... if, and only if, we -organize AWP so that non-opportunistic SGs can do it somehow. Otherwise, -if the other end has not initiated tunnel setup itself, it will not be -prepared to do so at our request.) - -Once a tunnel is up, packets going into it naturally are not intercepted -by OPI. However, we need to do something about the flip side of this too: -after deciding that we *cannot* set up a tunnel, either because we don't -have enough information or because the other security gateway is -uncooperative, we have to remember that for a while, so we don't keep -knocking on the same locked door. One plausible way of doing that is to -set up a bypass "tunnel" -- the equivalent of our current %passthrough -connection -- and have it managed like a real SCM tunnel (finite lifespan -etc.). This sounds a bit heavyweight, but in practice, the alternatives -all end up doing something very similar when examined closely. Note that -we need an extra variant of this, a block rather than a bypass, to cover -the case where local policy dictates that packets *not* be passed through; -we still have to remember the fact that we can't set up a real tunnel. - -When to tear tunnels down is a bit problematic, but if we're setting up a -potentially unbounded number of them, we have to tear them down *somehow* -*sometime*. It seems fairly obvious that we set a tentative lifespan, -probably fairly short (say 1min), and when it expires, we look to see if -the tunnel is still in use (say, has had traffic in the last half of the -lifespan). If so, we assign it a somewhat longer lifespan (say 10min), -after which we look again. If not, we close it down. (This lifespan is -independent of key lifetime; it is just the time when the tunnel's future -is next considered. This should happen reasonably frequently, unlike -rekeying, which is costly and shouldn't be too frequent.) Multi-step -backoff algorithms probably are not worth the trouble; looking every -10min doesn't seem onerous. - -For the tunnel-expiry decision, we need to know how long it has been since -the last traffic went through. A more detailed history of the traffic -does not seem very useful; a simple idle timer (or last-traffic timestamp) -is both necessary and sufficient. And KLIPS already has this. - -As noted, default initial lifespan should be short. However, Pluto should -keep a history of recently-closed tunnels, to detect cases where a tunnel -is being repeatedly re-established and should be given a longer lifespan. -(Not only is tunnel setup costly, but it adds user-visible delay, so -keeping a tunnel alive is preferable if we have reason to suspect more -traffic soon.) Any tunnel re-established within 10min of dying should have -10min added to its initial lifespan. (Just leaving all tunnels open longer -is unappealing -- adaptive lifetimes which are sensitive to the behavior -of a particular tunnel are wanted. Tunnels are relatively cheap entities -for us, but that is not necessarily true of all implementations, and there -may also be administrative problems in sorting through large accumulations -of idle tunnels.) - -It might be desirable to have detailed information about the initial -packet when determining lifespans. HTTP connections in particular are -notoriously bursty and repetitive. - -Arguably it would be nice to monitor TCP connection status. A still-open -TCP connection is almost a guarantee that more traffic is coming, while -the closing of the only TCP connection through a tunnel is a good hint -that none is. But the monitoring is complex, and it doesn't seem worth -the trouble. - -IKE connections likewise should be torn down when it appears the need has -passed. They should linger longer than the last tunnel they administer, -just in case they are needed again; the cost of retaining them is low. An -SG with only a modest number of them open might want to simply retain each -until rekeying time, with more aggressive management cutting in only when -the number gets large. (They should be torn down eventually, if only to -minimize the length of a status report, but rekeying is the only expensive -event for them.) - -It's worth remembering that tunnels sometimes go down because the other -end crashes, or disconnects, or has a network link break, and we don't get -any notice of this in the general case. (Even in the event of a crash and -successful reboot, we won't hear about it unless the other end has -specific reason to talk IKE to us immediately.) Of course, we have to -guard against being too quick to respond to temporary network outages, -but it's not quite the same issue for us as for TCP, because we can tear -down and then re-establish a tunnel without any user-visible effect except -a pause in traffic. And if the other end does go down and come back up, -we and it can't communicate *at all* (except via IKE) until we tear down -our tunnel. - -So... we need some kind of heartbeat mechanism. Currently there is none -in IKE, but there is discussion of changing that, and this seems like the -best approach. Doing a heartbeat at the IP level will not tell us about a -crash/reboot event, and sending heartbeat packets through tunnels has -various complications (they should stop at the far mouth of the tunnel -instead of going on to a subnet; they should not count against idle -timers; etc.). Heartbeat exchanges obviously should be done only when -there are tunnels established *and* there has been no recent incoming -traffic through them. It seems reasonable to do them at lifespan ends, -subject to appropriate rate limiting when more than one tunnel goes to the -same other SG. When all traffic between the two ends is supposed to go -via the tunnel, it might be reasonable to do a heartbeat -- subject to a -rate limiter to avoid DOS attacks -- if the kernel sees a non-tunnel -non-IKE packet from the other end. - -If a heartbeat gets no response, try a few (say 3) pings to check IP -connectivity; if one comes back, try another heartbeat; if it gets no -response, the other end has rebooted, or otherwise been re-initialized, -and its tunnels should be torn down. If there's no response to the pings, -note the fact and try the sequence again at the next lifespan end; if -there's nothing then either, declare the tunnels dead. - -Finally... except in cases where we've decided that the other end is dead -or has rebooted, tunnel teardown should always be coordinated with the -other end. This means interpreting and sending Delete notifications, and -also Initial-Contacts. Receiving a Delete for the other party's tunnel -SAs should lead us to tear down our end too -- SAs (SA bundles, really) -need to be considered as paired bidirectional entities, even though the -low-level protocols don't think of them that way. - - - -SGD, AWP - -Given a packet destination, how do we decide who to (attempt to) negotiate -a tunnel with? And as a related issue, how do the negotiating parties -authenticate each other? DNSSEC obviously provides the tools for the -latter, but how exactly do we use them? - -Having intercepted a packet, what we know is basically the IP addresses of -source and destination (plus, in principle, some information about the -desired communication, like protocol and port). We might be able to map -the source address to more information about the source, depending on how -well we control our local networks, but we know nothing further about the -destination. - -The obvious first thing to do is a DNS reverse lookup on the destination -address; that's about all we can do with available data. Ideally, we'd -like to get all necessary information with this one DNS lookup, because -DNS lookups are time-consuming -- all the more so if they involve a DNSSEC -signature-checking treewalk by the name server -- and we've got to hurry. -While it is unusual for a reverse lookup to yield records other than PTR -records (or possibly CNAME records, for RFC 2317 classless delegation), -there's no reason why it can't. - -(For purposes like logging, a reverse lookup is usually followed by a -forward lookup, to verify that the reverse lookup wasn't lying about the -host name. For our purposes, this is not vital, since we use stronger -authentication methods anyway.) - -While we want to get as much data as possible (ideally all of it) from one -lookup, it is useful to first consider how the necessary information would -be obtained if DNS lookups were instantaneous. Two pieces of information -are absolutely vital at this point: the IP address of the other end's -security gateway, and the SG's public key*. - -(* Actually, knowledge of the key can be postponed slightly -- it's not -needed until the second exchange of the negotiations, while we can't even -start negotiations without knowing the IP address. The SG is not -necessarily on the plain-IP route to the destination, especially when -multiple SGs are present.) - -Given instantaneous DNS lookups, we would: - -+ Start with a reverse lookup to turn the address into a name. - -+ Look for something like RFC-2782 SRV records using the name, to find out -who provides this particular service. If none comes back, we can abandon -the whole process. - -+ Select one SRV record, which gives us the name of a target host (plus -possibly one or more addresses, if the name server has supplied address -records as Additional Data for the SRV records -- this is recommended -behavior but is not required). - -+ Use the target name to look up a suitable KEY record, and also address -record(s) if they are still needed. - -This gives us the desired address(es) and key. However, it requires three -lookups, and we don't even find out whether there's any point in trying -until after the second. - -With real DNS lookups, which are far from instantaneous, some optimization -is needed. At the very least, typical cases should need fewer lookups. - -So when we do the reverse lookup on the IP address, instead of asking for -PTR, we ask for TXT. If we get none, we abandon opportunistic -negotiation, and set up a bypass/block with a relatively long life (say -6hr) because it's not worth trying again soon. (Note, there needs to be a -way to manually force an early retry -- say, by just clearing out all -memory of a particular address -- to cover cases where a configuration -error is discovered and fixed.) - -xxx need to discuss multi-string TXTs - -In the results, we look for at least one TXT record with content -"X-IPsec-Server(nnn)=a.b.c.d kkk", following RFC 1464 attribute/value -notation. (The "X-" indicates that this is tentative and experimental; -this design will probably need modification after initial experiments.) -Again, if there is no such record, we abandon opportunistic negotiation. - -"nnn" and the parentheses surrounding it are optional. If present, it -specifies a priority (low number high priority), as for MX records, to -control the order in which multiple servers are tried. If there are no -priorities, or there are ties, pick one randomly. - -"a.b.c.d" is the dotted-decimal IP address of the SG. (Suitable extensions -for IPv6, when the time comes, are straightforward.) - -"kkk" is either an RSA-MD5 public key in base-64 notation, as in the text -form of an RFC 2535 KEY record, or "@hhh". In the latter case, hhh is a -DNS name, under which one Host/Authentication/IPSEC/RSA-MD5 KEY record is -present, giving the server's authentication key. (The delay of the extra -lookup is undesirable, but practical issues of key management may make it -advisable not to duplicate the key itself in DNS entries for many -clients.) - -It unfortunately does appear that the authentication key has to be -associated with the server, not the client behind it. At the time when -the responder has to authenticate our SG, it does not know which of its -clients we are interested in (i.e., which key to use), and there is no -good way to tell it. (There are some bad ways; this decision may merit -re-examination after experimental use.) - -The responder authenticates our SG by doing a reverse lookup on its IP -address to get a Host/Authentication/IPSEC/RSA-MD5 KEY record. He can -attempt this in parallel with the early parts of the negotiation (since he -knows our SG IP address from the first negotiation packet), at the risk of -having to abandon the attempt and do a different lookup if we use -something different as our ID (see below). Unfortunately, he doesn't yet -know what client we will claim to represent, so he'll need to do another -lookup as part of phase 2 negotiation (unless the client *is* our SG), to -confirm that the client has a TXT X-IPsec-Server record pointing to our -SG. (Checking that the record specifies the same key is not important, -since the responder already has a trustworthy key for our SG.) - -Also unfortunately, opportunistic tunnels can only have degenerate subnets -(/32 subnets, containing one host) at their ends. It's superficially -attractive to negotiate broader connections... but without prearrangement, -you don't know whether you can trust the other end's claim to have a -specific subnet behind it. Fixing this would require a way to do a -reverse lookup on the *subnet* (you cannot trust information in DNS -records for a name or a single address, which may be controlled by people -who do not control the whole subnet) with both the address and the mask -included in the name. Except in the special case of a subnet masked on a -byte boundary (in which case RFC 1035's convention of an incomplete -in-addr.arpa name could be used), this would need extensions to the -reverse-map name space, which is awkward, especially in the presence of -RFC 2317 delegation. (IPv6 delegation is more flexible and it might be -easier there.) - -There is a question of what ID should be used in later steps of -negotiation. However, the desire not to put more DNS lookups in the -critical path suggests avoiding the extra complication of varied IDs, -except in the Road Warrior case (where an extra lookup is inevitable). -Also, figuring out what such IDs *mean* gets messy. To keep things simple, -except in the RW case, all IDs should be IP addresses identical to those -used in the packet headers. - -For Road Warrior, the RW must be the initiator, since the home-base SG has -no idea what address the RW will appear at. Moreover, in general the RW -does not control the DNS entries for his address. This inherently denies -the home base any authentication of the RW's IP address; the most it can -do is to verify an identity he provides, and perhaps decide whether it -wishes to talk to someone with that identity, but this does not verify his -right to use that IP address -- nothing can, really. - -(That may sound like it would permit some man-in-the-middle attacks, but -the RW can still do full authentication of the home base, so a man in the -middle cannot successfully impersonate home base. Furthermore, a man in -the middle must impersonate both sides for the DH exchange to work. So -either way, the IKE negotiation falls apart.) - -A Road Warrior provides an FQDN ID, used for a forward lookup to obtain a -Host/Authentication/IPSEC/RSA-MD5 KEY record. (Note, an FQDN need not -actually correspond to a host -- e.g., the DNS data for it need not -include an A record.) This suffices, since the RW is the initiator and -the responder knows his address from his first packet. - -Certain situations where a host has a more-or-less permanent IP address, -but does not control its DNS entries, must be treated essentially like -Road Warrior. It is unfortunate that DNS's old inverse-query feature -cannot be used (nonrecursively) to ask the initiator's local DNS server -whether it has a name for the address, because the address will almost -always have been obtained from a DNS name lookup, and it might be a lookup -of a name whose DNS entries the host *does* control. (Real examples of -this exist: the host has a preferred name whose host-controlled entry -includes an A record, but a reverse lookup on the address sends you to an -ISP-controlled name whose entry has an A record but not much else.) Alas, -inverse query is long obsolete and is not widely implemented now. - -There are some questions in failure cases. If we cannot acquire the info -needed to set up a tunnel, this is the no-tunnel-possible case. If we -reach an SG but negotiation fails, this too is the no-tunnel-possible -case, with a relatively long bypass/block lifespan (say 1hr) since -fruitless negotiations are expensive. (In the multiple-SG case, it seems -unlikely to be worthwhile to try other SGs just in case one of them might -have a configuration permitting successful negotiation.) - -Finally, there is a sticky problem with timeouts. If the other SG is down -or otherwise inaccessible, in the worst case we won't hear about this -except by not getting responses. Some other, more pathological or even -evil, failure cases can have the same result. The problem is that in the -case where a bypass is permitted, we want to decide whether a tunnel is -possible quickly. It gets even worse if there are multiple SGs, in which -case conceivably we might want to try them all (since some SGs being up -when others are down is much more likely than SGs differing in policy). - -The patience setting needs to be configurable policy, with a reasonable -default (to be determined by experiment). If it expires, we simply have -to declare the attempt a failure, and set up a bypass/block. (Setting up -a tentative bypass/block, and replacing it with a real tunnel if remaining -attempts do produce one, looks attractive at first glance... but exposing -the first few seconds of a connection is often almost as bad as exposing -the whole thing!) Such a bypass/block should have a short lifespan, say -10min, because the SG(s) might be only temporarily unavailable. - -The flip side of IKE waiting for a timeout is that all other forms of -feedback, e.g. "host not reachable", should be *ignored*, because you -cannot trust them! This may need kernel changes. - -Can AWP be done by non-opportunistic SGs? Probably not; existing SG -implementations generally aren't prepared to do anything suitable, except -perhaps via the messy business of certificates. There is one borderline -exception: some implementations rely on LDAP for at least some of their -information fetching, and it might be possible to substitute a custom LDAP -server which does the right things for them. Feasibility of this depends -on details, which we don't know well enough. - -[This could do with a full example, a complete packet by packet walkthrough -including all DNS and IKE traffic.] - - - -MFP - -Our current conn database simply isn't flexible enough to cover all this -properly. In particular, the responding Pluto needs a way to figure out -whether the connection it is being asked to make is legitimate. - -This is more subtle than it sounds, given the problem noted earlier, that -there's no clear way to authenticate claims to represent a non-degenerate -subnet. Our database has to be able to say "a connection to any host in -this subnet is okay" or "a connection to any subnet within this subnet is -okay", rather than "a connection to exactly this subnet is okay". (There -is some analogy to the Road Warrior case here, which may be relevant.) -This will require at least a re-interpretation of ipsec.conf. - -Interim stages of implementation of this will require a bit of thought. -Notably, we need some way of dealing with the lack of fully signed DNSSEC -records. Without user interaction, probably the best we can do is to -remember the results of old fetches, compare them to the results of new -fetches, and complain and disbelieve all of it if there's a mismatch. -This does mean that somebody who gets fake data into our very first fetch -will fool us, at least for a while, but that seems an acceptable tradeoff. - - - -Negotiation Issues - -There are various options which are nominally open to negotiation as part -of setup, but which have to be nailed down at least well enough that -opportunistic SGs can reliably interoperate. Somewhat arbitrarily and -tentatively, opportunistic SGs must support Main Mode, Oakley group 5 for -D-H, 3DES encryption and MD5 authentication for both ISAKMP and IPsec SAs, -RSA digital-signature authentication with keys between 2048 and 8192 bits, -and ESP doing both encryption and authentication. They must do key PFS -in Quick Mode, but not identity PFS. - - - -What we need from DNS - -Fortunately, we don't need any new record types or suchlike to make this -all work. We do, however, need attention to a couple of areas in DNS -implementation. - -First, size limits. Although the information we directly need from a -lookup is not enormous -- the only potentially-big item is the KEY record, -and there should be only one of those -- there is still a problem with -DNSSEC authentication signatures. With a 2048-bit key and assorted -supporting information, we will fill most of a 512-byte DNS UDP packet... -and if the data is to have DNSSEC authentication, at least one quite large -SIG record will come too. Plus maybe a TSIG signature on the whole -response, to authenticate it to our resolver. So: DNSSEC-capable name -servers must fix the 512-byte UDP limit. We're told there are provisions -for this; implementation of them is mandatory. - -Second, interface. It is unclear how the resolver interface will let us -ask for DNSSEC authentication. We would prefer to ask for "authentication -where possible", and get back the data with each item flagged by whether -authentication was available (and successful!) or not available. Having -to ask separately for authenticated and non-authenticated data would -probably be acceptable, *provided* both will be cached on the first -request, so the two requests incur only one set of (non-local) network -traffic. Either way, we want to see the name server and resolver do this -for us; that makes sense in any case, since it's important that -verification be done somewhere where it can be cached, the more centrally -the better. - -Finally, a wistful note: the ability to do a limited form of inverse -queries (an almost forgotten feature), to ask the local name server which -hostname it recently mapped to a particular address, would be quite -helpful. Note, this is *NOT* the same as a reverse lookup, and crude -fakes like putting a dotted-decimal address in brackets do not suffice. diff --git a/doc/opportunism-spec.txt b/doc/opportunism-spec.txt deleted file mode 100644 index fbe319a57..000000000 --- a/doc/opportunism-spec.txt +++ /dev/null @@ -1,1254 +0,0 @@ - - - - - - - - - - Opportunistic Encryption - - Henry Spencer - D. Hugh Redelmeier - henry@spsystems.net - hugh@mimosa.com - Linux FreeS/WAN Project - - - - Opportunistic encryption permits secure - (encrypted, authenticated) communication via IPsec - without connection-by-connection prearrangement, - either explicitly between hosts (when the hosts - are capable of it) or transparently via packet- - intercepting security gateways. It uses DNS - records (authenticated with DNSSEC) to provide the - necessary information for gateway discovery and - gateway authentication, and constrains negotiation - enough to guarantee success. - - Substantive changes since draft 3: write off - inverse queries as a lost cause; use Invalid-SPI - rather than Delete as notification of unknown SA; - minor wording improvements and clarifications. - This document takes over from the older ``Imple- - menting Opportunistic Encryption'' document. - - -1. Introduction - -A major goal of the FreeS/WAN project is opportunistic -encryption: a (security) gateway intercepts an outgoing -packet aimed at a remote host, and quickly attempts to nego- -tiate an IPsec tunnel to that host's security gateway. If -the attempt succeeds, traffic can then be secure, transpar- -ently (without changes to the host software). If the -attempt fails, the packet (or a retry thereof) passes -through in clear or is dropped, depending on local policy. -Prearranged tunnels bypass the packet interception etc., so -static VPNs can coexist with opportunistic encryption. - -This generalizes trivially to the end-to-end case: host and -security gateway simply are one and the same. Some opti- -mizations are possible in that case, but the basic scheme -need not change. - -The objectives for security systems need to be explicitly -stated. Opportunistic encryption is meant to achieve secure -communication, without prearrangement of the individual con- -nection (although some prearrangement on a per-host basis is - - - -Draft 4 3 May 2001 1 - - - - - - Opportunistic Encryption - - -required), between any two hosts which implement the proto- -col (and, if they act as security gateways, between hosts -behind them). Here ``secure'' means strong encryption and -authentication of packets, with authentication of partici- -pants--to prevent man-in-the-middle and impersonation -attacks--dependent on several factors. The biggest factor -is the authentication of DNS records, via DNSSEC or equiva- -lent means. A lesser factor is which exact variant of the -setup procedure (see section 2.2) is used, because there is -a tradeoff between strong authentication of the other end -and ability to negotiate opportunistic encryption with hosts -which have limited or no control of their reverse-map DNS -records: without reverse-map information, we can verify that -the host has the right to use a particular FQDN (Fully Qual- -ified Domain Name), but not whether that FQDN is authorized -to use that IP address. Local policy must decide whether -authentication or connectivity has higher priority. - -Apart from careful attention to detail in various areas, -there are three crucial design problems for opportunistic -encryption. It needs a way to quickly identify the remote -host's security gateway. It needs a way to quickly obtain -an authentication key for the security gateway. And the -numerous options which can be specified with IKE must be -constrained sufficiently that two independent implementa- -tions are guaranteed to reach agreement, without any -explicit prearrangement or preliminary negotiation. The -first two problems are solved using DNS, with DNSSEC ensur- -ing that the data obtained is reliable; the third is solved -by specifying a minimum standard which must be supported. - -A note on philosophy: we have deliberately avoided providing -six different ways to do each job, in favor of specifying -one good one. Choices are provided only when they appear to -be necessary, or at least important. - -A note on terminology: to avoid constant circumlocutions, an -ISAKMP/IKE SA, possibly recreated occasionally by rekeying, -will be referred to as a ``keying channel'', and a set of -IPsec SAs providing bidirectional communication between two -IPsec hosts, possibly recreated occasionally by rekeying, -will be referred to as a ``tunnel'' (it could conceivably -use transport mode in the host-to-host case, but we advocate -using tunnel mode even there). The word ``connection'' is -here used in a more generic sense. The word ``lifetime'' -will be avoided in favor of ``rekeying interval'', since -many of the connections will have useful lives far shorter -than any reasonable rekeying interval, and hence the two -concepts must be separated. - -A note on document structure: Discussions of why things were -done a particular way, or not done a particular way, are -broken out in paragraphs headed ``Rationale:'' (to preserve -the flow of the text, many such paragraphs are deferred to - - - -Draft 4 3 May 2001 2 - - - - - - Opportunistic Encryption - - -the ends of sections). Paragraphs headed ``Ahem:'' are dis- -cussions of where the problem is being made significantly -harder by problems elsewhere, and how that might be cor- -rected. Some meta-comments are enclosed in []. - -Rationale: The motive is to get the Internet encrypted. -That requires encryption without connection-by-connection -prearrangement: a system must be able to reliably negotiate -an encrypted, authenticated connection with a total -stranger. While end-to-end encryption is preferable, doing -opportunistic encryption in security gateways gives enormous -leverage for quick deployment of this technology, in a world -where end-host software is often primitive, rigid, and out- -dated. - -Rationale: Speed is of the essence in tunnel setup: a con- -nection-establishment delay longer than about 10 seconds -begins to cause problems for users and applications. Thus -the emphasis on rapidity in gateway discovery and key fetch- -ing. - -Ahem: Host-to-host opportunistic encryption would be utterly -trivial if a fast public-key encryption/signature algorithm -was available. You would do a reverse lookup on the desti- -nation address to obtain a public key for that address, and -simply encrypt all packets going to it with that key, sign- -ing them with your own private key. Alas, this is impracti- -cal with current CPU speeds and current algorithms (although -as noted later, it might be of some use for limited pur- -poses). Nevertheless, it is a useful model. - -2. Connection Setup - -For purposes of discussion, the network is taken to look -like this: - - Source----Initiator----...----Responder----Destination - -The intercepted packet comes from the Source, bound for the -Destination, and is intercepted at the Initiator. The Ini- -tiator communicates over the insecure Internet to the -Responder. The Source and the Initiator might be the same -host, or the Source might be an end-user host and the Ini- -tiator a security gateway (SG). Likewise for the Responder -and the Destination. - -Given an intercepted packet, whose useful information (for -our purposes) is essentially only the Destination's IP -address, the Initiator must quickly determine the Responder -(the Destination's SG) and fetch everything needed to -authenticate it. The Responder must do likewise for the -Initiator. Both must eventually also confirm that the other -is authorized to act on behalf of the client host behind it -(if any). - - - -Draft 4 3 May 2001 3 - - - - - - Opportunistic Encryption - - -An important subtlety here is that if the alternative to an -IPsec tunnel is plaintext transmission, negative results -must be obtained quickly. That is, the decision that no -tunnel can be established must also be made rapidly. - -2.1. Packet Interception - -Interception of outgoing packets is relatively straightfor- -ward in principle. It is preferable to put the intercepted -packet on hold rather than dropping it, since higher-level -retries are not necessarily well-timed. There is a problem -of hosts and applications retrying during negotiations. ARP -implementations, which face the same problem, use the -approach of keeping the most recent packet for an as-yet- -unresolved address, and throwing away older ones. (Incre- -menting of request numbers etc. means that replies to older -ones may no longer be accepted.) - -Is it worth intercepting incoming packets, from the outside -world, and attempting tunnel setup based on them? No, -unless and until a way can be devised to initiate oppor- -tunistic encryption to a non-opportunistic responder, -because if the other end has not initiated tunnel setup -itself, it will not be prepared to do so at our request. - -Rationale: Note, however, that most incoming packets will -promptly be followed by an outgoing packet in response! -Conceivably it might be useful to start early stages of -negotiation, at least as far as looking up information, in -response to an incoming packet. - -Rationale: If a plaintext incoming packet indicates that the -other end is not prepared to do opportunistic encryption, it -might seem that this fact should be noted, to avoid consum- -ing resources and delaying traffic in an attempt at oppor- -tunistic setup which is doomed to fail. However, this would -be a major security hole, since the plaintext packet is not -authenticated; see section 2.5. - -2.2. Algorithm - -For clarity, the following defers most discussion of error -handling to the end. - -Step 1. Initiator does a DNS reverse lookup on the Destina- - tion address, asking not for the usual PTR records, - but for TXT records. Meanwhile, Initiator also - sends a ping to the Destination, to cause any other - dynamic setup actions to start happening. (Ping - replies are disregarded; the host might not be - reachable with plaintext pings.) - -Step 2A. If at least one suitable TXT record (see section - 2.3) comes back, each contains a potential - - - -Draft 4 3 May 2001 4 - - - - - - Opportunistic Encryption - - - Responder's IP address and that Responder's public - key (or where to find it). Initiator picks one TXT - record, based on priority (see 2.3), thus picking a - Responder. If there was no public key in the TXT - record, the Initiator also starts a DNS lookup (as - specified by the TXT record) to get KEY records. - -Step 2B. If no suitable TXT record is available, and policy - permits, Initiator designates the Destination - itself as the Responder (see section 2.4). If pol- - icy does not permit, or the Destination is unre- - sponsive to the negotiation, then opportunistic - encryption is not possible, and Initiator gives up - (see section 2.5). - -Step 3. If there already is a keying channel to the Respon- - der's IP address, the Initiator uses the existing - keying channel; skip to step 10. Otherwise, the - Initiator starts an IKE Phase 1 negotiation (see - section 2.7 for details) with the Responder. The - address family of the Responder's IP address dic- - tates whether the keying channel and the outside of - the tunnel should be IPv4 or IPv6. - -Step 4. Responder gets the first IKE message, and responds. - It also starts a DNS reverse lookup on the Initia- - tor's IP address, for KEY records, on speculation. - -Step 5. Initiator gets Responder's reply, and sends first - message of IKE's D-H exchange (see 2.4). - -Step 6. Responder gets Initiator's D-H message, and - responds with a matching one. - -Step 7. Initiator gets Responder's D-H message; encryption - is now established, authentication remains to be - done. Initiator sends IKE authentication message, - with an FQDN identity if a reverse lookup on its - address will not yield a suitable KEY record. - (Note, an FQDN need not actually correspond to a - host--e.g., the DNS data for it need not include an - A record.) - -Step 8. Responder gets Initiator's authentication message. - If there is no identity included, Responder waits - for step 4's speculative DNS lookup to finish; it - should yield a suitable KEY record (see 2.3). If - there is an FQDN identity, responder discards any - data obtained from step 4's DNS lookup; does a for- - ward lookup on the FQDN, for a KEY record; waits - for that lookup to return; it should yield a suit- - able KEY record. Either way, Responder uses the - KEY data to verify the message's hash. Responder - replies with an authentication message, with an - - - -Draft 4 3 May 2001 5 - - - - - - Opportunistic Encryption - - - FQDN identity if a reverse lookup on its address - will not yield a suitable KEY record. - -Step 9A. (If step 2A was used.) The Initiator gets the - Responder's authentication message. Step 2A has - provided a key (from the TXT record or via DNS - lookup). Verify message's hash. Encrypted and - authenticated keying channel established, man-in- - middle attack precluded. - -Step 9B. (If step 2B was used.) The Initiator gets the - Responder's authentication message, which must con- - tain an FQDN identity (if the Responder can't put a - TXT in his reverse map he presumably can't do a KEY - either). Do forward lookup on the FQDN, get suit- - able KEY record, verify hash. Encrypted keying - channel established, man-in-middle attack pre- - cluded, but authentication weak (see 2.4). - -Step 10. Initiator initiates IKE Phase 2 negotiation (see - 2.7) to establish tunnel, specifying Source and - Destination identities as IP addresses (see 2.6). - The address family of those addresses also deter- - mines whether the inside of the tunnel should be - IPv4 or IPv6. - -Step 11. Responder gets first Phase 2 message. Now the - Responder finally knows what's going on! Unless - the specified Source is identical to the Initiator, - Responder initiates DNS reverse lookup on Source IP - address, for TXT records; waits for result; gets - suitable TXT record(s) (see 2.3), which should con- - tain either the Initiator's IP address or an FQDN - identity identical to that supplied by the Initia- - tor in step 7. This verifies that the Initiator is - authorized to act as SG for the Source. Responder - replies with second Phase 2 message, selecting - acceptable details (see 2.7), and establishes tun- - nel. - -Step 12. Initiator gets second Phase 2 message, establishes - tunnel (if he didn't already), and releases the - intercepted packet into it, finally. - -Step 13. Communication proceeds. See section 3 for what - happens later. - -As additional information becomes available, notably in -steps 1, 2, 4, 8, 9, 11, and 12, there is always a possibil- -ity that local policy (e.g., access limitations) might pre- -vent further progress. Whenever possible, at least attempt -to inform the other end of this. - - - - - -Draft 4 3 May 2001 6 - - - - - - Opportunistic Encryption - - -At any time, there is a possibility of the negotiation fail- -ing due to unexpected responses, e.g. the Responder not -responding at all or rejecting all Initiator's proposals. -If multiple SGs were found as possible Responders, the Ini- -tiator should try at least one more before giving up. The -number tried should be influenced by what the alternative -is: if the traffic will otherwise be discarded, trying the -full list is probably appropriate, while if the alternative -is plaintext transmission, it might be based on how long the -tries are taking. The Initiator should try as many as it -reasonably can, ideally all of them. - -There is a sticky problem with timeouts. If the Responder -is down or otherwise inaccessible, in the worst case we -won't hear about this except by not getting responses. Some -other, more pathological or even evil, failure cases can -have the same result. The problem is that in the case where -plaintext is permitted, we want to decide whether a tunnel -is possible quickly. There is no good solution to this, -alas; we just have to take the time and do it right. (Pass- -ing plaintext meanwhile looks attractive at first glance... -but exposing the first few seconds of a connection is often -almost as bad as exposing the whole thing. Worse, if the -user checks the status of the connection, after that brief -window it looks secure!) - -The flip side of waiting for a timeout is that all other -forms of feedback, e.g. ``host not reachable'', arguably -should be ignored, because in the absence of authenticated -ICMP, you cannot trust them! - -Rationale: An alternative, sometimes suggested, to the use -of explicit DNS records for SG discovery is to directly -attempt IKE negotiation with the destination host, and -assume that any relevant SG will be on the packet path, will -intercept the IKE packets, and will impersonate the destina- -tion host for the IKE negotiation. This is superficially -attractive but is a very bad idea. It assumes that routing -is stable throughout negotiation, that the SG is on the -plaintext-packets path, and that the destination host is -routable (yes, it is possible to have (private) DNS data for -an unroutable host). Playing extra games in the plaintext- -packet path hurts performance and can be expected to be -unpopular. Various difficulties ensue when there are multi- -ple SGs along the path (there is already bad experience with -this, in RSVP), and the presence of even one can make it -impossible to do IKE direct to the host when that is what's -wanted. Worst of all, such impersonation breaks the IP net- -work model badly, making problems difficult to diagnose and -impossible to work around (and there is already bad experi- -ence with this, in areas like web caching). - -Rationale: (Step 1.) Dynamic setup actions might include -establishment of demand-dialed links. These might be - - - -Draft 4 3 May 2001 7 - - - - - - Opportunistic Encryption - - -present anywhere along the path, so one cannot rely on out- -of-band communication at the Initiator to trigger them. -Hence the ping. - -Rationale: (Step 2.) In many cases, the IP address on the -intercepted packet will be the result of a name lookup just -done. Inverse queries, an obscure DNS feature from the dis- -tant past, in theory can be used to ask a DNS server to -reverse that lookup, giving the name that produced the -address. This is not the same as a reverse lookup, and the -difference can matter a great deal in cases where a host -does not control its reverse map (e.g., when the host's IP -address is dynamically assigned). Unfortunately, inverse -queries were never widely implemented and are now considered -obsolete. Phooey. - -Ahem: Support for a small subset of this admittedly-obscure -feature would be useful. Unfortunately, it seems unlikely. - -Rationale: (Step 3.) Using only IP addresses to decide -whether there is already a relevant keying channel avoids -some difficult problems. In particular, it might seem that -this should be based on identities, but those are not known -until very late in IKE Phase 1 negotiations. - -Rationale: (Step 4.) The DNS lookup is done on speculation -because the data will probably be useful and the lookup can -be done in parallel with IKE activity, potentially speeding -things up. - -Rationale: (Steps 7 and 8.) If an SG does not control its -reverse map, there is no way it can prove its right to use -an IP address, but it can nevertheless supply both an iden- -tity (as an FQDN) and proof of its right to use that iden- -tity. This is somewhat better than nothing, and may be -quite useful if the SG is representing a client host which -can prove its right to its IP address. (For example, a -fixed-address subnet might live behind an SG with a dynami- -cally-assigned address; such an SG has to be the Initiator, -not the Responder, so the subnet's TXT records can contain -FQDN identities, but with that restriction, this works.) It -might sound like this would permit some man-in-the-middle -attacks in important cases like Road Warrior, but the RW can -still do full authentication of the home base, so a man in -the middle cannot successfully impersonate home base, and -the D-H exchange doesn't work unless the man in the middle -impersonates both ends. - -Rationale: (Steps 7 and 8.) Another situation where proof -of the right to use an identity can be very useful is when -access is deliberately limited. While opportunistic encryp- -tion is intended as a general-purpose connection mechanism -between strangers, it may well be convenient for prearranged -connections to use the same mechanism. - - - -Draft 4 3 May 2001 8 - - - - - - Opportunistic Encryption - - -Rationale: (Steps 7 and 8.) FQDNs as identities are avoided -where possible, since they can involve synchronous DNS -lookups. - -Rationale: (Step 11.) Note that only here, in Phase 2, does -the Responder actually learn who the Source and Destination -hosts are. This unfortunately demands a synchronous DNS -lookup to verify that the Initiator is authorized to repre- -sent the Source, unless they are one and the same. This and -the initial TXT lookup are the only synchronous DNS lookups -absolutely required by the algorithm, and they appear to be -unavoidable. - -Rationale: While it might seem unlikely that a refusal to -cooperate from one SG could be remedied by trying another-- -presumably they all use the same policies--it's conceivable -that one might be misconfigured. Preferably they should all -be tried, but it may be necessary to set some limits on this -if alternatives exist. - -2.3. DNS Records - -Gateway discovery and key lookup are based on TXT and KEY -DNS records. The TXT record specifies IP address or other -identity of a host's SG, and possibly supplies its public -key as well, while the KEY record supplies public keys not -found in TXT records. - -2.3.1. TXT - -Opportunistic-encryption SG discovery uses TXT records with -the content: - - X-IPsec-Gateway(nnn)=iii kkk - -following RFC 1464 attribute/value notation. Records which -do not contain an ``='', or which do not have exactly the -specified form to the left of it, are ignored. (Near misses -perhaps should be reported.) - -The nnn is an unsigned integer which will fit in 16 bits, -specifying an MX-style preference (lower number = stronger -preference) to control the order in which multiple SGs are -tried. If there are ties, pick one, randomly enough that -the choice will probably be different each time. The pref- -erence field is not optional; use ``0'' if there is no mean- -ingful preference ordering. - -The iii part identifies the SG. Normally this is a dotted- -decimal IPv4 address or a colon-hex IPv6 address. The sole -exception is if the SG has no fixed address (see 2.4) but -the host(s) behind it do, in which case iii is of the form -``@fqdn'', where fqdn is the FQDN that the SG will use to -identify itself (in step 7 of section 2.2); such a record - - - -Draft 4 3 May 2001 9 - - - - - - Opportunistic Encryption - - -cannot be used for SG discovery by an Initiator, but can be -used for SG verification (step 11 of 2.2) by a Responder. - -The kkk part is optional. If it is present, it is an RSA- -MD5 public key in base-64 notation, as in the text form of -an RFC 2535 KEY record. If it is not present, this speci- -fies that the public key can be found in a KEY record -located based on the SG's identification: if iii is an IP -address, do a reverse lookup on that address, else do a for- -ward lookup on the FQDN. - -Rationale: While it is unusual for a reverse lookup to go -for records other than PTR records (or possibly CNAME -records, for RFC 2317 classless delegation), there's no rea- -son why it can't. The TXT record is a temporary stand-in -for (we hope, someday) a new DNS record for SG identifica- -tion and keying. Keeping the setup process fast requires -minimizing the number of DNS lookups, hence the desire to -put all the information in one place. - -Rationale: The use of RFC 1464 notation avoids collisions -with other uses of TXT records. The ``X-'' in the attribute -name indicates that this format is tentative and experimen- -tal; this design will probably need modification after ini- -tial experiments. The format is chosen with an eye on even- -tual binary encoding. Note, in particular, that the TXT -record normally contains the address of the SG, not (repeat, -not) its name. Name-to-address conversion is the job of -whatever generates the TXT record, which is expected to be a -program, not a human--this is conceptually a binary record, -temporarily using a text encoding. The ``@fqdn'' form of -the SG identity is for specialized uses and is never mapped -to an address. - -Ahem: A DNS TXT record contains one or more character -strings, but RFC 1035 does not describe exactly how a multi- -string TXT record is interpreted. This is relevant because -a string can be at most 255 characters, and public keys can -exceed this. Empirically, the standard pattern is that each -string which is both less than 255 characters and not the -final string of the record should have a blank appended to -it, and the strings of the record should then be concate- -nated. (This observation is based on how BIND 8 transforms -a TXT record from text to DNS binary.) - -2.3.2. KEY - -An opportunistic-encryption KEY record is an Authentication- -permitted, Entity (host), non-Signatory, IPsec, RSA/MD5 -record (that is, its first four bytes are 0x42000401), as -per RFCs 2535 and 2537. KEY records with other flags, pro- -tocol, or algorithm values are ignored. - - - - - -Draft 4 3 May 2001 10 - - - - - - Opportunistic Encryption - - -Rationale: Unfortunately, the public key has to be associ- -ated with the SG, not the client host behind it. The -Responder does not know which client it is supposed to be -representing, or which client the Initiator is representing, -until far too late. - -Ahem: Per-client keys would reduce vulnerability to key com- -promise, and simplify key changes, but they would require -changes to IKE Phase 1, to separately identify the SG and -its initial client(s). (At present, the client identities -are not known to the Responder until IKE Phase 2.) While -the current IKE standard does not actually specify (!) who -is being identified by identity payloads, the overwhelming -consensus is that they identify the SG, and as seen earlier, -this has important uses. - -2.3.3. Summary - -For reference, the minimum set of DNS records needed to make -this all work is either: - -1. TXT in Destination reverse map, identifying Responder - and providing public key. - -2. KEY in Initiator reverse map, providing public key. - -3. TXT in Source reverse map, verifying relationship to - Initiator. - -or: - -1. TXT in Destination reverse map, identifying Responder. - -2. KEY in Responder reverse map, providing public key. - -3. KEY in Initiator reverse map, providing public key. - -4. TXT in Source reverse map, verifying relationship to - Initiator. - -Slight complications ensue for dynamic addresses, lack of -control over reverse maps, etc. - -2.3.4. Implementation - -In the long run, we need either a tree of trust or a web of -trust, so we can trust our DNS data. The obvious approach -for DNS is a tree of trust, but there are various practical -problems with running all of this through the root servers, -and a web of trust is arguably more robust anyway. This is -logically independent of opportunistic encryption, and a -separate design proposal will be prepared. - - - - - -Draft 4 3 May 2001 11 - - - - - - Opportunistic Encryption - - -Interim stages of implementation of this will require a bit -of thought. Notably, we need some way of dealing with the -lack of fully signed DNSSEC records right away. Without -user interaction, probably the best we can do is to remember -the results of old fetches, compare them to the results of -new fetches, and complain and disbelieve all of it if -there's a mismatch. This does mean that somebody who gets -fake data into our very first fetch will fool us, at least -for a while, but that seems an acceptable tradeoff. (Obvi- -ously there needs to be a way to manually flush the remem- -bered results for a specific host, to permit deliberate -changes.) - -2.4. Responders Without Credentials - -In cases where the Destination simply does not control its -DNS reverse-map entries, there is no verifiable way to -determine a suitable SG. This does not make communication -utterly impossible, though. - -Simply attempting negotiation directly with the host is a -last resort. (An aggressive implementation might wish to -attempt it in parallel, rather than waiting until other -options are known to be unavailable.) In particular, in -many cases involving dynamic addresses, it will work. It -has the disadvantage of delaying the discovery that oppor- -tunistic encryption is entirely impossible, but the case -seems common enough to justify the overhead. - -However, there are policy issues here either way, because it -is possible to impersonate such a host. The host can supply -an FQDN identity and verify its right to use that identity, -but except by prearrangement, there is no way to verify that -the FQDN is the right one for that IP address. (The data -from forward lookups may be controlled by people who do not -own the address, so it cannot be trusted.) The encryption -is still solid, though, so in many cases this may be useful. - -2.5. Failure of Opportunism - -When there is no way to do opportunistic encryption, a pol- -icy issue arises: whether to put in a bypass (which allows -plaintext traffic through) or a block (which discards it, -perhaps with notification back to the sender). The choice -is very much a matter of local policy, and may depend on -details such as the higher-level protocol being used. For -example, an SG might well permit plaintext HTTP but forbid -plaintext Telnet, in which case both a block and a bypass -would be set up if opportunistic encryption failed. - -A bypass/block must, in practice, be treated much like an -IPsec tunnel. It should persist for a while, so that high- -overhead processing doesn't have to be done for every -packet, but should go away eventually to return resources. - - - -Draft 4 3 May 2001 12 - - - - - - Opportunistic Encryption - - -It may be simplest to treat it as a degenerate tunnel. It -should have a relatively long lifetime (say 6h) to keep the -frequency of negotiation attempts down, except in the case -where the other SG simply did not respond to IKE packets, -where the lifetime should be short (say 10min) because the -other SG is presumably down and might come back up again. -(Cases where the other SG responded to IKE with unauthenti- -cated error reports like ``port unreachable'' are border- -line, and might deserve to be treated as an intermediate -case: while such reports cannot be trusted unreservedly, in -the absence of any other response, they do give some reason -to suspect that the other SG is unable or unwilling to par- -ticipate in opportunistic encryption.) - -As noted in section 2.1, one might think that arrival of a -plaintext incoming packet should cause a bypass/block to be -set up for its source host: such a packet is almost always -followed by an outgoing reply packet; the incoming packet is -clear evidence that opportunistic encryption is not avail- -able at the other end; attempting it will waste resources -and delay traffic to no good purpose. Unfortunately, this -means that anyone out on the Internet who can forge a source -address can prevent encrypted communication! Since their -source addresses are not authenticated, plaintext packets -cannot be taken as evidence of anything, except perhaps that -communication from that host is likely to occur soon. - -There needs to be a way for local administrators to remove a -bypass/block ahead of its normal expiry time, to force a -retry after a problem at the other end is known to have been -fixed. - -2.6. Subnet Opportunism - -In principle, when the Source or Destination host belongs to -a subnet and the corresponding SG is willing to provide tun- -nels to the whole subnet, this should be done. There is no -extra overhead, and considerable potential for avoiding -later overhead if similar communication occurs with other -members of the subnet. Unfortunately, at the moment, oppor- -tunistic tunnels can only have degenerate subnets (single -hosts) at their ends. (This does, at least, set up the key- -ing channel, so that negotiations for tunnels to other hosts -in the same subnets will be considerably faster.) - -The crucial problem is step 11 of section 2.2: the Responder -must verify that the Initiator is authorized to represent -the Source, and this is impossible for a subnet because -there is no way to do a reverse lookup on it. Information -in DNS records for a name or a single address cannot be -trusted, because they may be controlled by people who do not -control the whole subnet. - - - - - -Draft 4 3 May 2001 13 - - - - - - Opportunistic Encryption - - -Ahem: Except in the special case of a subnet masked on a -byte boundary (in which case RFC 1035's convention of an -incomplete in-addr.arpa name could be used), subnet lookup -would need extensions to the reverse-map name space, perhaps -along the lines of that commonly done for RFC 2317 delega- -tion. IPv6 already has suitable name syntax, as in RFC -2874, but has no specific provisions for subnet entries in -its reverse maps. Fixing all this is is not conceptually -difficult, but is logically independent of opportunistic -encryption, and will be proposed separately. - -A less-troublesome problem is that the Initiator, in step 10 -of 2.2, must know exactly what subnet is present on the -Responder's end so he can propose a tunnel to it. This -information could be included in the TXT record of the Des- -tination (it would have to be verified with a subnet lookup, -but that could be done in parallel with other operations). -The Initiator presumably can be configured to know what sub- -net(s) are present on its end. - -2.7. Option Settings - -IPsec and IKE have far too many useless options, and a few -useful ones. IKE negotiation is quite simplistic, and can- -not handle even simple discrepancies between the two SGs. -So it is necessary to be quite specific about what should be -done and what should be proposed, to guarantee interoper- -ability without prearrangement or other negotiation proto- -cols. - -Rationale: The prohibition of other negotiations is simply -because there is no time. The setup algorithm (section 2.2) -is lengthy already. - -[Open question: should opportunistic IKE use a different -port than normal IKE?] - -Somewhat arbitrarily and tentatively, opportunistic SGs must -support Main Mode, Oakley group 5 for D-H, 3DES encryption -and MD5 authentication for both ISAKMP and IPsec SAs, -RSA/MD5 digital-signature authentication with keys between -2048 and 8192 bits, and ESP doing both encryption and -authentication. They must do key PFS in Quick Mode, but not -identity PFS. They may support IPComp, preferably using -Deflate, but must not insist on it. They may support AES as -an alternative to 3DES, but must not insist on it. - -Rationale: Identity PFS essentially requires establishing a -complete new keying channel for each new tunnel, but key PFS -just does a new Diffie-Hellman exchange for each rekeying, -which is relatively cheap. - -Keying channels must remain in existence at least as long as -any tunnel created with them remains (they are not costly, - - - -Draft 4 3 May 2001 14 - - - - - - Opportunistic Encryption - - -and keeping the management path up and available simplifies -various issues). See section 3.1 for related issues. Given -the use of key PFS, frequent rekeying does not seem critical -here. In the absence of strong reason to do otherwise, the -Initiator should propose rekeying at 8hr-or-1MB. The -Responder must accept any proposal which specifies a rekey- -ing time between 1hr and 24hr inclusive and a rekeying vol- -ume between 100KB and 10MB inclusive. - -Given the short expected useful life of most tunnels (see -section 3.1), very few of them will survive long enough to -be rekeyed. In the absence of strong reason to do other- -wise, the Initiator should propose rekeying at 1hr-or-100MB. -The Responder must accept any proposal which specifies a -rekeying time between 10min and 8hr inclusive and a rekeying -volume between 1MB and 1000MB inclusive. - -It is highly desirable to add some random jitter to the -times of actual rekeying attempts, to break up ``convoys'' -of rekeying events; this and certain other aspects of robust -rekeying practice will be the subject of a separate design -proposal. - -Rationale: The numbers used here for rekeying intervals are -chosen quite arbitrarily and should be re-assessed after -some implementation experience is gathered. - -3. Renewal and Teardown - -3.1. Aging - -When to tear tunnels down is a bit problematic, but if we're -setting up a potentially unbounded number of them, we have -to tear them down somehow sometime. - -Set a short initial tentative lifespan, say 1min, since most -net flows in fact last only a few seconds. When that -expires, look to see if the tunnel is still in use (defini- -tion: has had traffic, in either direction, in the last half -of the tentative lifespan). If so, assign it a somewhat -longer tentative lifespan, say 20min, after which, look -again. If not, close it down. (This tentative lifespan is -independent of rekeying; it is just the time when the tun- -nel's future is next considered. This should happen reason- -ably frequently, unlike rekeying, which is costly and -shouldn't be too frequent.) Multi-step backoff algorithms -are not worth the trouble; looking every 20min doesn't seem -onerous. - -If the security gateway and the client host are one and the -same, tunnel teardown decisions might wish to pay attention -to TCP connection status, as reported by the local TCP -layer. A still-open TCP connection is almost a guarantee -that more traffic is coming, while the demise of the only - - - -Draft 4 3 May 2001 15 - - - - - - Opportunistic Encryption - - -TCP connection through a tunnel is a strong hint that none -is. If the SG and the client host are separate machines, -though, tracking TCP connection status requires packet -snooping, which is complicated and probably not worthwhile. - -IKE keying channels likewise are torn down when it appears -the need has passed. They always linger longer than the -last tunnel they administer, in case they are needed again; -the cost of retaining them is low. Other than that, unless -the number of keying channels on the SG gets large, the SG -should simply retain all of them until rekeying time, since -rekeying is the only costly event. When about to rekey a -keying channel which has no current tunnels, note when the -last actual keying-channel traffic occurred, and close the -keying channel down if it wasn't in the last, say, 30min. -When rekeying a keying channel (or perhaps shortly before -rekeying is expected), Initiator and Responder should re- -fetch the public keys used for SG authentication, against -the possibility that they have changed or disappeared. - -See section 2.7 for discussion of rekeying intervals. - -Given the low user impact of tearing down and rebuilding a -connection (a tunnel or a keying channel), rekeying attempts -should not be too persistent: one can always just rebuild -when needed, so heroic efforts to preserve an existing con- -nection are unnecessary. Say, try every 10s for a minute -and every minute for 5min, and then give up and declare the -connection (and all other connections to that IKE peer) -dead. - -Rationale: In future, more sophisticated, versions of this -protocol, examining the initial packet might permit a more -intelligent guess at the tunnel's useful life. HTTP connec- -tions in particular are notoriously bursty and repetitive. - -Rationale: Note that rekeying a keying connection basically -consists of building a new keying connection from scratch, -using IKE Phase 1, and abandoning the old one. - -3.2. Teardown and Cleanup - -Teardown should always be coordinated with the other end. -This means interpreting and sending Delete notifications. - -On receiving a Delete for the outbound SAs of a tunnel (or -some subset of them), tear down the inbound ones too, and -notify the other end with a Delete. Tunnels need to be con- -sidered as bidirectional entities, even though the low-level -protocols don't think of them that way. - -When the deletion is initiated locally, rather than as a -response to a received Delete, send a Delete for (all) the -inbound SAs of a tunnel. If no responding Delete is - - - -Draft 4 3 May 2001 16 - - - - - - Opportunistic Encryption - - -received for the outbound SAs, try re-sending the original -Delete. Three tries spaced 10s apart seems a reasonable -level of effort. (Indefinite persistence is not necessary; -whether the other end isn't cooperating because it doesn't -feel like it, or because it is down/disconnected/etc., the -problem will eventually be cleared up by other means.) - -After rekeying, transmission should switch to using the new -SAs (ISAKMP or IPsec) immediately, and the old leftover SAs -should be cleared out promptly (and Deletes sent) rather -than waiting for them to expire. This reduces clutter and -minimizes confusion. - -Since there is only one keying channel per remote IP -address, the question of whether a Delete notification has -appeared on a ``suitable'' keying channel does not arise. - -Rationale: The pairing of Delete notifications effectively -constitutes an acknowledged Delete, which is highly desir- -able. - -3.3. Outages and Reboots - -Tunnels sometimes go down because the other end crashes, or -disconnects, or has a network link break, and there is no -notice of this in the general case. (Even in the event of a -crash and successful reboot, other SGs don't hear about it -unless the rebooted SG has specific reason to talk to them -immediately.) Over-quick response to temporary network out- -ages is undesirable... but note that a tunnel can be torn -down and then re-established without any user-visible effect -except a pause in traffic, whereas if one end does reboot, -the other end can't get packets to it at all (except via -IKE) until the situation is noticed. So a bias toward quick -response is appropriate, even at the cost of occasional -false alarms. - -Heartbeat mechanisms are somewhat unsatisfactory for this. -Unless they are very frequent, which causes other problems, -they do not detect the problem promptly. - -Ahem: What is really wanted is authenticated ICMP. This -might be a case where public-key encryption/authentication -of network packets is the right thing to do, despite the -expense. - -In the absence of that, a two-part approach seems warranted. - -First, when an SG receives an IPsec packet that is addressed -to it, and otherwise appears healthy, but specifies an -unknown SA and is from a host that the receiver currently -has no keying channel to, the receiver must attempt to -inform the sender via an IKE Initial-Contact notification -(necessarily sent in plaintext, since there is no suitable - - - -Draft 4 3 May 2001 17 - - - - - - Opportunistic Encryption - - -keying channel). This must be severely rate-limited on both -ends; one notification per SG pair per minute seems ample. - -Second, there is an obvious difficulty with this: the Ini- -tial-Contact notification is unauthenticated and cannot be -trusted. So it must be taken as a hint only: there must be -a way to confirm it. - -What is needed here is something that's desirable for debug- -ging and testing anyway: an IKE-level ping mechanism. Ping- -ing direct at the IP level instead will not tell us about a -crash/reboot event. Sending pings through tunnels has vari- -ous complications (they should stop at the far mouth of the -tunnel instead of going on to a subnet; they should not -count against idle timers; etc.). What is needed is a con- -tinuity check on a keying channel. (This could also be used -as a heartbeat, should that seem useful.) - -IKE Ping delivery need not be reliable, since the whole -point of a ping is simply to provoke an acknowledgement. -They should preferably be authenticated, but it is not clear -that this is absolutely necessary, although if they are not -they need encryption plus a timestamp or a nonce, to foil -replay mischief. How they are implemented is a secondary -issue, and a separate design proposal will be prepared. - -Ahem: Some existing implementations are already using (pri- -vate) notify value 30000 (``LIKE_HELLO'') as ping and (pri- -vate) notify value 30002 (``SHUT_UP'') as ping reply. - -If an IKE Ping gets no response, try some (say 8) IP pings, -spaced a few seconds apart, to check IP connectivity; if one -comes back, try another IKE Ping; if that gets no response, -the other end probably has rebooted, or otherwise been re- -initialized, and its tunnels and keying channel(s) should be -torn down. - -In a similar vein, giving limited rekeying persistence, a -short network outage could take some tunnels down without -disrupting others. On receiving a packet for an unknown SA -from a host that a keying channel is currently open to, send -that host a Invalid-SPI notification for that SA. The other -host can then tear down the half-torn-down tunnel, and nego- -tiate a new tunnel for the traffic it presumably still wants -to send. - -Finally, it would be helpful if SGs made some attempt to -deal intelligently with crashes and reboots. A deliberate -shutdown should include an attempt to notify all other SGs -currently connected by keying channels, using Deletes, that -communication is about to fail. (Again, these will be taken -as teardowns; attempts by the other SGs to negotiate new -tunnels as replacements should be ignored at this point.) -And when possible, SGs should attempt to preserve - - - -Draft 4 3 May 2001 18 - - - - - - Opportunistic Encryption - - -information about currently-connected SGs in non-volatile -storage, so that after a crash, an Initial-Contact can be -sent to previous partners to indicate loss of all previ- -ously-established connections. - -4. Conclusions - -This design appears to achieve the objective of setting up -encryption with strangers. The authentication aspects also -seem adequately addressed if the destination controls its -reverse-map DNS entries and the DNS data itself can be reli- -ably authenticated as having originated from the legitimate -administrators of that subnet/FQDN. The authentication sit- -uation is less satisfactory when DNS is less helpful, but it -is difficult to see what else could be done about it. - -5. References - -[TBW] - -6. Appendix: Separate Design Proposals TBW - -o How can we build a web of trust with DNSSEC? (See sec- - tion 2.3.4.) - -o How can we extend DNS reverse lookups to permit reverse - lookup on a subnet? (Both address and mask must appear - in the name to be looked up.) (See section 2.6.) - -o How can rekeying be done as robustly as possible? (At - least partly, this is just documenting current FreeS/WAN - practice.) (See section 2.7.) - -o How should IKE Pings be implemented? (See section 3.3.) - - - - - - - - - - - - - - - - - - - - - - - -Draft 4 3 May 2001 19 - - diff --git a/doc/opportunism.howto b/doc/opportunism.howto deleted file mode 100644 index 14b5ed5a2..000000000 --- a/doc/opportunism.howto +++ /dev/null @@ -1,415 +0,0 @@ -FreeS/WAN Opportunism HowTo -=========================== - -RCSID $Id: opportunism.howto,v 1.1 2004/03/15 20:35:21 as Exp $ - -D. Hugh Redelmeier - - -FreeS/WAN, the LINUX IPSEC implementation, is intended to allow -systems to connect through secure tunnels with or without prearrangement. -We use the term "Opportunism" to describe tunnels set up without -prearrangement. This HowTo will show you how to set your system up -for Opportunism. - -You are expected to already have built and used FreeS/WAN. Much more -information about FreeS/WAN is provided at http://www.freeswan.org. -This document is only intended to describe the support for -opportunism. The features described here are available in FreeS/WAN -version 1.91 or later (there were important bugs up until 1.95). - -For a more complete description of the design of Opportunism, see our -paper "Opportunistic Encryption" (available as opportunism.spec in -the same directory as this document). - - -Steps -===== - -- Understand what you are attempting. Security requires care. - Problems are hard to untangle. Be sure to read the last section - "Important Limitations". - -- Install FreeS/WAN (version 1.91 or later). - -- Add appropriate DNS records to your reverse-map domains. - -- Add suitable conns to /etc/ipsec.conf. - -- Try it out: start it, monitor it, fix it. - -- Now you understand the system better, reread "Important Limitations" - -These steps are also an outline of this document. - - -Theory -====== - -FreeS/WAN runs on a machine that we will call a "Security Gateway". -Usually this machine is a gateway to the internet. It may be that the -only machine for which it provides gateway services is itself, but -that is just a special case -- we will still call it a Security -Gateway. - -A FreeS/WAN Security Gateway implements secure tunnels to other -Security Gateways. One problem is to arrange for these tunnels to be -created and used. If opportunism is enabled, a Security Gateway -running FreeS/WAN will intercept the first outbound packet to a -particular destination (IP address), and try to negotiate a security -tunnel suitable for traffic to that destination. - -To make this work going the other way, the Security Gateway must be -willing to negotiate with peers trying to protect traffic initiated -from their side. - -The first novel problem is that our Security Gateway needs to discover -the IP address of the other Security Gateway for the packet that -prompted the negotiation. Oh, and quickly discover if there is none --- that negotiation will be impossible. - -The second novel problem is that our Security Gateway needs to -authenticate the other Security Gateway. This authentication needs to -ensure that the other Security Gateway is who it claims to be AND that -it is authorized to represent the client for which it claims to be the -gateway. - -The roles in a particular negotiation are: - Source----Initiator----...----Responder----Destination - -The Source and Destination are endpoints of the traffic that is to be -protected. The Source is the one that happened to send the first -packet of traffic. Neither needs to be aware of IPSEC or FreeS/WAN. -That is the job of their respective Security Gateways, Initiator and -Responder. The names "Initiator" and "Responder" match those used in -the IPSEC standards for IKE negotiation. Remember that Source and -Initiator could be the same machine; similarly, Destination and -Responder could be the same. All traffic from Source or Destination -must flow through their Security Gateways if it is to be considered -for protection. These roles are fluid -- they can be different for -each negotiation. - -We use the DNS (the Domain Name System) as a distributed database to -publish the required information. - - -DNS Records Required -==================== - -See section 2.3 of "Opportunistic Encryption" for a fuller -explanation. - -Generally, we need to add records to the reverse-map DNS entries for -the client machine and its Security Gateway machine. There are -special cases that are exceptions. - -A Security Gateway that is going to initiate an Opportunistic -negotiation needs to provide a way for the Responding SG to find a -public key for the Initiator to allow authentication. This is -accomplished by putting the public key in a KEY record in the -reverse-map of the Initiator. Conveniently, the KEY record can -be generated by the ipsec_showhostkey(8) command. - - ipsec showhostkey - -Here is an example of the output, with many characters of the key -itself left out: - - ; RSA 2048 bits xy.example.com Sat Apr 15 13:53:22 2000 - xy.example.com. IN KEY 0x4200 4 1 AQOF8tZ2...+buFuFn/ - -=> Copy the output of the command into the zone information for the - reverse-map of the Security Gateway's public interface. - -Each client that is to be protected by Opportunistic Encryption must -include a special TXT record in its reverse-map. The -ipsec_showhostkey(8) command can create this too. Remember: this -command must be run on the Security Gateway where the ipsec.secrets -file resides. You must tell the command what IP address to put in the -TXT record. The IP address is that of the Security Gateway. - - ipsec showhostkey --txt 10.11.12.13 - -This command might produce the output: - - ; RSA 2048 bits xy.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=10.11.12.13 AQOF8tZ2...+buFuFn/" - -- The quotes matter: this is a single string, as far as DNS is - concerned. - -- The X-IPsec-Server is a prefix that signifies that the TXT record - contains Opportunism configuration information. - -- The (10) specifies a precedence for this record. This is similar - to MX record preferences. Lower numbers have stronger preference. - -- 10.11.12.13 specifies the IP address of the Security Gateway for - this machine. - -- AQOF8tZ2...+buFuFn/ is the (shortened) encoding of the RSA Public - key of the Security Gateway. - -=> Added this output to the zone information for the reverse-map for - each client machine. This gets a bit dull and repetitive. - -Unfortunately, not every administrator has control over the contents -of the reverse-map. The only case where we can work around this is -where the Initiator has no suitable reverse map. In this case, the -Source's TXT record gives @FQDN ("Fully Qualified Domain Name") in -place of its Security Gateway's IP address. This FQDN must match the -ID-payload used by the Initiator. Furthermore, a forward lookup for a -KEY record on the FQDN must yield the Initiator's public key. - -If the Source's IP address is the same as the Initiator's IP address, -the Responder will assume that the Initiator is authorized to talk for -the Source (itself!). In this case, the Responder won't try to fetch -the Source's TXT record from the reverse map for the Source's IP -address. - -These two features can be combined. If the Source and the Initiator -are the same (i.e. the Security Gateway is protecting itself), and the -Initiator uses a @FQDN ID (leftid=@example.com), then the -administrator of that machine need only have installed a KEY record in -the FQDN domain -- he need not control any reverse map. - -Obscure fact: the forward lookup is only done by a Responder, and then -only when the Initiator's ID payload specifies the FQDN. There is no -provision for a Responder with no control over its reverse-map. - -Beware: DNS changes sometimes take a long time to propagate. - - -Configuring FreeS/WAN -===================== - -To enable opportunism, you must include a suitable conn in -/etc/ipsec.conf and you must enable it. - -A suitable conn looks roughly like an ordinary conn. It more closely -resembles a Road Warrior conn (a Road Warrior conn is one that has a -wildcard %any specified as the other Security Gateway). But in the -Opportunistic case, both the other Security Gateway AND its client are -unknown ahead of time. - -conn client-to-anyone # for our client subnet - leftsubnet=10.3.2.1.0/24 # any single client in our subnet - also=sg-to-anyone # rest is same as for SG - -conn sg-to-anyone # for our Security Gateway - left=%defaultroute # our SG (defaults leftnexthop too) - right=%opportunistic - authby=rsasig # almost always the right choice - keyingtries=2 # don't be persistent -- peer might disappear - auto=route # enable at ipsec startup - -(%defaultroute only works if you have specified -interfaces=%defaultroute. Since this isn't the topic of the howto, -you will have to look at the other documentation to find out how to -handle other cases.) - -You can have any number of opportunistic conns, but generally it only -makes sense to have one for each client subnet and one for the -Security Gateway itself. - -Currently only one interface may be used for opportunism: Pluto knows -nothing about routing, so would be unable to choose amongst several. -Almost certainly our side's nexthop must be predetermined -(%defaultroute will do that). - -Note: the routing done for outbound Opportunism will catch any packets -not covered by a more specific route. This is what you want for -packets that are also covered by an eroute. But packets caught by the -route and not an eroute will be subject to the no-eroute policy of -KLIPS, which defaults to %drop. Remember that routing ignores the -packet's source address, but erouting pays attention to it. So if -Opportunism is enabled, it is best to provide for it covering all IP -addresses behind or on the Security Gateway. - -To enable these conns for inbound opportunistic negotiation, they must be ---added. auto=add would accomplish this at ipsec startup, but if you cannot -wait: - ipsec auto --add sg-to-anyone - ipsec auto --add client-to-anyone - -To enable these conns for outbound opportunistic negotiation, they must -be both --added and --routed. Outbound packets will then be trapped -and will trigger negotiation. auto=route would cause this to happen -at startup, but if you wish to do this at another time: - ipsec auto --add sg-to-anyone - ipsec auto --add client-to-anyone - ipsec auto --route sg-to-anyone - ipsec auto --route client-to-anyone - - -Getting DNS Through -=================== - -There is a serious chicken-and-egg problem. Outbound Opportunism blocks -communication with an IP address until Pluto discovers whether that IP -address can have an IPSEC connection negotiated. This discovery takes -DNS queries. These DNS queries might involve communicating with -arbitrary IP addresses. Thus we require DNS queries to succeed before -any communication succeeds, including those same DNS queries! The way -out of this conundrum is to exempt at least some DNS query IP traffic -from Opportunism. - -There are several possible solutions, all of which have advantages and -disadvantages. - -1. If you use a single machine, outside your Security Gateway, as DNS -server, you can build a clear path (or even an IPSEC tunnel, but not -opportunistically) directly to that machine. - -- you could use a type=passthrough conn to provide a clear path - between your machine and the DNS machine. - -- better still, you could explicitly create an IPSEC connection to - your DNS server. Just be sure that Pluto does not need to access - DNS to find the IP addresses or RSA public keys for that connection! - -- you could install an explicit route to the DNS machine through - your public interface (not ipsecN). This will bypass KLIPS - processing. You might have to adjust your firewall. For example: - - route add host -net ns.example.com gw gw.example.com dev eth1 - -2. Generally, it is better to run DNS on your Security Gateway. This -leads to a need for non-opportunistic paths to an arbitrary number of -DNS servers in the internet. One way to accomplish this is to NOT -have outbound opportunism cover the SG itself, but only the subnet -behind it. In other words, leave out the - ipsec auto --route sg-to-anyone -You must also add a type=passthrough eroute specifically for -sg-to-anyone (without this, the traffic will be handled by the KLIPS -no-eroute policy). - -3. It is actually possible to use a single machine inside your client -subnet as a DNS server. The techniques listed in 1 could be used to -let it communicate with other DNS servers without interference. This -might have advantages over 1 if the DNS machine *only* did DNS. -Another technique (not often possible or reasonable) is to give this -machine another route to the internet, one that avoids the SG. - -4. DNS queries will eventually time out and then Pluto will give up -and establish %pass eroutes. So communications should start flowing. - -We would like to have better solutions. Perhaps we will in the -future. Suggestions are welcome. - - -Figuring out what is going on -============================= - -Since Opportunism lets your SG operate with less supervision, you may -be puzzled by what it is up to. The usual tools exist, but their use -is more important. To look at what Pluto is doing, use: - ipsec auto --status -To look at what KLIPS is doing, use - ipsec look - -To just see the kernel's eroute table, look at the "file" -/proc/net/ipsec_eroute. It contains a description of all the eroutes -in the kernel. Here is an example: - -10 10.2.1.0/24 -> 0.0.0.0/0 => %trap -259 10.2.1.115/32 -> 10.19.75.161/32 => tun0x1002@10.19.75.145 -71 10.44.73.97/32 -> 0.0.0.0/0 => %trap -4119 10.44.73.97/32 -> 10.114.121.41/32 => %pass - -You read each line as: a packet from within the first subnet, destined -for the second subnet, will be processed by the Security Association -Identity (SAID) specified last. The first column is the number of -(outbound) packets processed by this eroute. - -For shunt eroutes, the SAID is printed as just the type of shunt: -%pass pass the packet through with no processing -%drop discard the packet -%reject discard the packet and notify sender -%hold keep the last packet; discard others -%trap cause any trapped packet to generate a PF_KEY ACQUIRE - to request negotiation; install a corresponding %hold - shunt and attach this packet to the %hold - -For other eroutes, the SAID is printed as a triple: protocol (three -letters), SPI (32-bit number in hex), and destination IP address. -Protocols include: - -tun IP in IP encapsulation (used for most tunnels) -esp ESP encapsulation -- part of an IPSEC SA group -ah AH packet authentication -- part of an IPSEC SA group - -So, looking at our sample eroutes: - -10 10.2.1.0/24 -> 0.0.0.0/0 => %trap - - This is a TRAP (int0x104) shunt eroute. It was installed by - Pluto so that it can catch all traffic from its client subnet - to the world at large. Ten outbound packets have been trapped. - -259 10.2.1.115/32 -> 10.19.75.161/32 => tun0x1002@10.19.75.145 - - This is a tunnel eroute: packets from 10.2.1.115 (within - our client subnet) going to 10.19.75.161 will be encrypted - and sent to the peer SG 10.19.75.145. This was the product - of an Opportunistic negotiation (a hint is that each client - subnet has only one member). 259 packets have been sent - through this tunnel. - -71 10.44.73.97/32 -> 0.0.0.0/0 => %trap - - This is another TRAP shunt eroute. It is to catch traffic - from the Security Gateway to the world. It has caught - 71 outbound packets. - -4119 10.44.73.97/32 -> 10.114.121.41/32 => %pass - - This is a %pass (0x100) shunt eroute. It was installed when an - attempted Opportunistic negotiation failed because the reverse - domain of 10.114.121.41 had no suitable TXT record. 4119 - outbound packets have been passed. - - -Important Limitations -===================== - -Pluto's DNS lookup is synchronous (single-threaded). Not only does -this slow things down, but it turns out that in extreme cases where -there are a lot of ACQUIRE messages from KLIPS at once, some of those -messages can be lost and communications will be blocked by the %hold -eroute that Pluto doesn't know about. Pluto now looks every 2 minutes -for any %holds that it missed. - -DNS lookup is not verified -- we don't use Secure DNS. A spoofed DNS -could compromise Opportunism. - -There are several new opportunities for Denial of Service attacks. -For example, a Bad Guy could spray our system with pings with forged -source addresses. For each unique source address, our system would do -a (synchronous!) DNS lookup. - -Once a %pass eroute is added for a failed negotiation, it will stay -until it has been inactive for about 15 minutes. The only activity -that counts is outbound -- not surprising since a %pass only affects -outbound traffic. - -If a destination's DNS entry specifies the information we need for -negotiation, Pluto will not let communications proceed without -negotiating a Security Tunnel. - -There is currently no way to tear down a tunnel that is no longer in -use. To add insult to injury, when the lifetime is about to be -exceeded, the initiating Pluto will rekey! Restarting will clear -these out. rekey=no doesn't solve this since SA expiry would be -uncoordinated and hence cause packets to be lost. - -If one side of a Security Tunnel restarts, but doesn't initiate -negotiation with its peer, the peer will not be able to communicate -with it until the peer thinks the tunnel needs rekeying due to -lifetime, or the restarted Security Gateway decides to negotiate for -its own reasons. - -It isn't clear what firewall policies make sense with Opportunism. - -If VPN and Opportunism connections coexist, security policies -implemented via a firewall can only distinguish traffic by IP address. diff --git a/doc/opportunism.known-issues b/doc/opportunism.known-issues deleted file mode 100644 index 90752dee3..000000000 --- a/doc/opportunism.known-issues +++ /dev/null @@ -1,287 +0,0 @@ -Known issues with Opportunistic Encryption Claudia Schmeing ------------------------------------------- - - -This is an overview of known issues with OE. - - -This document supplements: - - -FreeS/WAN Quickstart Guide doc/quickstart.html - -Opportunism HOWTO doc/opportunism.howto - -Opportunism spec doc/opportunism.spec - -Internet Draft doc/draft-richardson-ipsec-opportunistic.txt - - - -* Use the most recent Linux FreeS/WAN 2.x release from ftp.xs4all.nl - to try OE. - - -DESIGN LIMITATIONS - - -* Because Opportunistic Encryption relies on DNS: - - to authenticate one FreeS/WAN to another, and - - to prove that we have the right to protect traffic for a given IP, - this authentication/authorization is only as strong as your DNS is - secure. - - Without secure DNS, OE protects against passive snooping only. - Because the public key and gateway information that FreeS/WAN gets from - DNS is not authenticated, a man-in-the-middle attack is still possible. - We hope that as DNSsec is widely adopted, OE with strong authentication - will become more widespread. - - However, our software does not yet distinguish between strongly and weakly - authenticated OE. This information might be useful for defining local - security policy. - - -* Denial of service attacks are possible against OE. If you rely on OE rather - than VPN to connect several offices, a determined attacker could prevent you - from communicating securely. - - -* OE challenges the notion that all IPsec peers are "friends". With OE, - strangers can potentially tunnel IPsec packets _through_ your defenses - against cleartext packets. This may call for a re-visit to firewall policy. - - -* FreeS/WAN only creates OE connections when it traps an outgoing packet. - Since most traffic is two-way, for most traffic, FreeS/WAN 2.x may soon - trap an outgoing packet and create an IPsec connection to - protect both incoming and outgoing traffic. However, if a local - FreeS/WAN box accepts inbound traffic from a remote peer but - generates no outbound traffic in response, the local FreeS/WAN will not - attempt to initiate OE. Of course, the peer may also initiate OE upon - trapping its own outbound traffic. - - -* OE is only as reliable as your DNS is. - - If your DNS service is flaky, you will not be able to reliably establish - OE connections to known OE-capable peers. - - If you ping a peer, but your FreeS/WAN does not find a TXT record signifying - the peer's ability to respond to OE negotiation), FreeS/WAN will not try to - opportunistically initiate, and communication will fallback to clear. - - For more secure and reliable DNS, we recommend that you run DNS - within your security perimeter, either on your security gateway, or - on a machine to which you have a VPN connection. It is also possible - to have your DNS server located elsewhere on your LAN, though this may - cause lag on startup. - - This mailing list message explains how to run a local caching name server: - http://lists.freeswan.org/pipermail/design/2003-January/004205.html - - See also "Getting DNS through" in opportunism.howto - http://lists.freeswan.org/pipermail/design/2002-April/002285.html . - - - -CURRENT ISSUES - -* There are several special issues re: using OE when running FreeS/WAN with - kernel native IPsec, introduced in the 2.6 kernel. Please see - doc/2.6.known-issues. - -* If A and B have an OE connection, but A is rebooted, normally A will try to - re-connect to B and (if it has no DNS-related failures) it will succeed. - But, if A is set up for responder-only OE, you will have a one-way - connection until B notices that its original tunnel has expired. For details - see: - - http://lists.freeswan.org/pipermail/design/2002-May/002582.html - http://lists.freeswan.org/pipermail/design/2002-June/002610.html - - TIP: If an OE connection isn't behaving, you can recreate it with - - ipsec whack --oppohere sourceIPaddress --oppothere targetIPaddress - - -* There is no good clean facility to delete OE connections. - Available are: - - ipsec auto --status to list connections - ipsec whack --deletestate to delete by state#. - - -* You may experience seeming gaps at rekey time. Once you generate traffic, - you will find that the OE connection returns. - - By default, OE connections are not rekeyed; if they were we'd have a - mountain of useless connections. As a consequence, if your OE connection is - idle at rekey time, it will go down until you generate further traffic. - To ensure prompt rekeying, you can run a ping thorough the OE tunnel. - - -* At the moment, you can only run active OE on one physical interface. - - Active means --routed, to trap outbound packets. It is this route - that is a problem. - - Untested theory: you can have multiple active OE conns, for different - source addresses, but they all have to point their traffic out the single - interface. - - When responding: you can only define one OE connection (per host or subnet) - in ipsec.conf, and that conn will apply to one interface. Normally this - will be the public interface which your default route uses; it is, however, - configurable. - - Theoretically, it might make sense to select between multiple OE conns - based on some criterion, such as address ranges. This might be useful for - local OE, or in a complex routing scenario. - - Currently, Pluto expects only one OE connection. If you add another, - Pluto may choose randomly between them, producing unpredictable results. - - -* Building OE conns between nodes on a LAN is not possible. - - This is a side effect of conflicts about ARP entries - in the rt_cache and our "stupid routing tricks". - There is no known workaround at this time. - - "Stupid routing tricks" are an ongoing issue, and should - go away in a future software revision. - - See these explanations: - http://lists.freeswan.org/pipermail/design/2002-April/002285.html - http://lists.freeswan.org/pipermail/design/2002-August/003249.html - - -* FreeS/WAN may not correctly follow a CNAME (Canonical Name) trail resulting - from reverse DNS delegation. - - Solution: Use a recent Bind 9 (we tested with Bind snap-pre9.3) for the - DNS services which the FreeS/WAN box relies on. - - Reason: This Bind correctly implements "implied helper support" for - traditional DNS records, and so can follow a properly constructed CNAME - record trail which ends in a TXT record. Thus, in cases where a reverse - domain has been delegated, FreeS/WAN + Bind 9 can find a TXT record and - create an OE connection. - - For more on the problem, see "OLD ISSUES", below. - - -* To make OE operation smoother, we may need a script that runs and warns - if we have the reverse DNS records, but not the software running. - The reverse records advertise that we can do OE, but when the software is - not running this is false advertising. - - - -OLD ISSUES - -* Coterminal OE doesn't work in practise. This includes OE-in-WAVEsec. - Solved in 2.02. - - Old diagnosis: - - If you have coterminal OE connections (two OE connections which share - one endpoint), you should have use of one of the encrypted links, but it - is not clear which one KLIPS will prefer. In particular, the behaviour - may not be symmetrical. - - Worse yet, it just seems to trip over itself and be generally - unworkable. - - Weird but predictable: - - If you have both a gateway and a host who advertise (via DNS) an - ability to do OE you need to be serious about doing host-based - OE, or you will be stuck in initiator-only mode. If your host - advertises but does not run OE, then when a peer tries to connect to - your host, it will fail to clear. The peer will then not try to encrypt - traffic bound for that host as it travels to the gateway. To remedy - the situation, restart ipsec on the peer (or otherwise flush out - the %pass eroute), and ping the peer from your host to initiate - OE. - - -* One-way connection was created on rekey. Solved in 2.0. - - If one side (A) has a shorter _keylife_ than the other, - and that side also has _rekey=no_, then when the keylife has - expired, it will expect that its peer (B) will make a new conn to replace - the existing one. Unfortunately, B has no idea. - - B continues to send out encrypted packets on the original connection, - while A passes the return packets along in the clear. - - There is a proposed patch for (A) here: - http://lists.freeswan.org/pipermail/design/2002-July/003114.html - - -* Failure to look up own host name is a show stopper. - Solved in 1.98 and 1.98b. - - Solution: new setting %dnsondemand. Usage: - - leftrsasigkey=%dnsondemand # now in sample ipsec.conf - rightrsasigkey=%dnsondemand. - - From man ipsec.conf: - - The value %dnsondemand means the key is to fetched from DNS - at the time it is needed. - - If Linux FreeS/WAN can't get the key for your public interface from - DNS, it will not keep trying, and you will not be able to do OE. - - The error message is: - - May 14 09:40:24 road Pluto[21210]: failure to fetch key for 193.110.157.18 - from DNS: failure querying DNS for KEY of 18.157.110.193.in-addr.arpa.: - Host name lookup failure - - Workaround: 1 or 2 - 1. Supply a key in the conn. leftrsasigkey=0s... - 2. Fix the KEY lookup failure and try again. - - -* Assertion failure at OE rekey time. Fixed in 2.0pre0. Patch for 1.98b posted - at http://lists.freeswan.org/pipermail/design/2002-August/003347.html - - -* 1.91 to 1.94 have serious problems with %trap and %hold bugs. These bugs, - introduced while coding the support structure for OE, affect both OE and VPN - connections. - - -* OE may not work with reverse delegation (CNAMEs). This problem was once - capable of being a show stopper. - - When relying on Bind versions before 9 for local DNS services, FreeS/WAN - could not follow a well constructed CNAME trail that ended in a TXT or KEY - record. Although OE required both record types, in practise we noticed the - problem with the more common TXT lookups, rather than the rarer KEY lookups. - Bind 9 largely solves the problem, by correctly seeking TXT records in - delegated reverse domains. In addition, OE between two FreeS/WAN 2.02 or - later boxes no longer relies on KEY records. - - Old symptoms: - - When a DNS server queried by Linux FreeS/WAN follows a CNAME, - it seems to forget what record type it is looking for, and it - returns a PTR, despite the fact that another record type was requested. - - Workaround: - - Send your provider KEY and TXT records for direct insertion into the - reverse ZONE files, rather than asking your provider to delegate authority - using CNAME. - - People who own IP blocks, rather than leasing them, may not - experience this problem. If you were assigned IPs more than - five years ago, you may own your IPs. - - diff --git a/doc/opportunism.nr b/doc/opportunism.nr deleted file mode 100644 index c5cae757a..000000000 --- a/doc/opportunism.nr +++ /dev/null @@ -1,1115 +0,0 @@ -.DA "3 May 2001" -.ds LH " -.ds CH "Opportunistic Encryption -.ds RH " -.ds LF "Draft 4+ -.ds CF "\\*(DY -.ds RF % -.de P -.LP -.. -.de R -.LP -\fBRationale:\fR -.. -.de A -.LP -\fBAhem:\fR -.. -.TL -Opportunistic Encryption -.AU -Henry Spencer -D. Hugh Redelmeier -.AI -henry@spsystems.net -hugh@mimosa.com -Linux FreeS/WAN Project -.AB no -xxx cases where reverses not controlled, all possibilities. -xxx DHR suggests okay if gateway doesn't control reverse but destination does. -xxx level of patience where Responder just doesn't answer the phone. -xxx IKE finger to get basic keying info, to be confirmed via DNSSEC? -xxx packets from some OE connections might get special status, -if the other end is definitely someone we trust. -Opportunistic encryption permits secure (encrypted, authenticated) -communication via IPsec without connection-by-connection prearrangement, -either explicitly between hosts (when the hosts are capable of it) or -transparently via packet-intercepting security gateways. -It uses DNS records (authenticated with DNSSEC) to provide -the necessary information for gateway discovery and gateway authentication, -and constrains negotiation enough to guarantee success. -.sp -Substantive changes since draft 3: -write off inverse queries as a lost cause; -use Invalid-SPI rather than Delete as notification of unknown SA; -minor wording improvements and clarifications. -This document takes over from the older ``Implementing Opportunistic -Encryption'' document. -.AE -.NH 1 -Introduction -.P -A major goal of the FreeS/WAN project is opportunistic encryption: -a (security) gateway intercepts an outgoing packet aimed at a -remote host, and quickly attempts to negotiate an IPsec tunnel to that -host's security gateway. -If the attempt succeeds, traffic can then be secure, -transparently (without changes to the host software). -If the attempt fails, -the packet (or a retry thereof) passes through in clear or is dropped, -depending on local policy. -Prearranged tunnels bypass the packet interception etc., so static VPNs -can coexist with opportunistic encryption. -.P -This generalizes trivially to the end-to-end case: -host and security gateway simply are one and the same. -Some optimizations are possible in that case, -but the basic scheme need not change. -.P -The objectives for security systems need to be explicitly stated. -Opportunistic encryption is meant to achieve secure communication, -without prearrangement of the individual connection -(although some prearrangement on a per-host basis is required), -between any two hosts which implement the protocol -(and, if they act as security gateways, -between hosts behind them). -Here ``secure'' means strong encryption and authentication of packets, -with authentication of participants\(emto prevent man-in-the-middle -and impersonation attacks\(emdependent on several factors. -The biggest factor is the authentication of DNS records, -via DNSSEC or equivalent means. -A lesser factor is which exact variant -of the setup procedure (see section 2.2) is used, -because there is a tradeoff between strong authentication of the other end -and ability -to negotiate opportunistic encryption with hosts which have limited -or no control of their reverse-map DNS records: -without reverse-map information, -we can verify that the host has the right to use a particular FQDN -(Fully Qualified Domain Name), -but not whether that FQDN is authorized to use that IP address. -Local policy must decide whether authentication -or connectivity has higher priority. -.P -Apart from careful attention to detail in various areas, -there are three crucial design problems for opportunistic encryption. -It needs a way to quickly identify the remote host's security gateway. -It needs a way to quickly obtain an authentication key for the -security gateway. -And the numerous options which can be specified with IKE -must be constrained sufficiently that two independent implementations are -guaranteed to reach agreement, -without any explicit prearrangement or preliminary negotiation. -The first two problems are solved using DNS, -with DNSSEC ensuring that the data obtained is reliable; -the third is solved by specifying a minimum standard which must be supported. -.P -A note on philosophy: -we have deliberately avoided providing six different -ways to do each job, in favor of specifying one good one. -Choices are -provided only when they appear to be necessary, -or at least important. -.P -A note on terminology: -to avoid constant circumlocutions, -an ISAKMP/IKE SA, possibly recreated occasionally by rekeying, -will be referred to as a ``keying channel'', -and a set of IPsec SAs providing bidirectional communication between -two IPsec hosts, -possibly recreated occasionally by rekeying, -will be referred to as a ``tunnel'' -(it could conceivably use transport mode in the host-to-host case, -but we advocate using tunnel mode even there). -The word ``connection'' is here used in a more generic sense. -The word ``lifetime'' will be avoided in favor of ``rekeying interval'', -since many of the connections will have useful lives far shorter -than any reasonable rekeying interval, -and hence the two concepts must be separated. -.P -A note on document structure: -Discussions of \fIwhy\fR things were done a particular way, -or not done a particular way, -are broken out in paragraphs headed ``Rationale:'' -(to preserve the flow of the text, many such paragraphs are deferred -to the ends of sections). -Paragraphs headed ``Ahem:'' are discussions of where the problem is being -made significantly harder by problems elsewhere, -and how that might be corrected. -Some meta-comments are enclosed in []. -.R -The motive is to get the Internet encrypted. -That requires encryption without connection-by-connection prearrangement: -a system must be able to -reliably negotiate an encrypted, authenticated -connection with a total stranger. -While end-to-end encryption is preferable, -doing opportunistic encryption in security gateways -gives enormous leverage for quick deployment of this technology, -in a world where end-host software is often primitive, rigid, and outdated. -.R -Speed is of the essence in tunnel setup: -a connection-establishment delay longer than about 10 seconds -begins to cause problems for users and applications. -Thus the emphasis on rapidity in gateway discovery and key fetching. -.A -Host-to-host opportunistic encryption -would be utterly trivial if a fast public-key -encryption/signature -algorithm was available. -You would do a reverse lookup on the destination address to obtain a -public key for that address, -and simply encrypt all packets going to it with that key, -signing them with your own private key. -Alas, this is impractical with current CPU speeds and current algorithms -(although as noted later, it might be of some use for limited purposes). -Nevertheless, it is a useful model. -.NH 1 -Connection Setup -.P -For purposes of discussion, the network is taken to look like this: -.DS -Source----Initiator----...----Responder----Destination -.DE -The intercepted packet comes from the Source, -bound for the Destination, -and is intercepted at the Initiator. -The Initiator communicates over the insecure Internet to the Responder. -The Source and the Initiator might be the same host, -or the Source might be an end-user host and the Initiator a -security gateway (SG). -Likewise for the Responder and the Destination. -.P -Given an intercepted packet, -whose useful information (for our purposes) -is essentially only the Destination's IP address, -the Initiator -must quickly determine the Responder (the Destination's SG) and -fetch everything needed to authenticate it. -The Responder must do likewise for the Initiator. -Both must eventually also confirm that the other is authorized to act -on behalf of the client host behind it (if any). -.P -An important subtlety here is that if the alternative to an IPsec tunnel -is plaintext transmission, negative results must be obtained quickly. -That is, -the decision that \fIno\fR tunnel can be established must also be made rapidly. -.NH 2 -Packet Interception -.P -Interception of outgoing packets is relatively straightforward -in principle. -It is preferable to put the intercepted packet on hold rather than -dropping it, since higher-level retries are not necessarily well-timed. -There is a problem of hosts and applications retrying during negotiations. -ARP implementations, which face the same problem, -use the approach of keeping the \fImost recent\fR -packet for an as-yet-unresolved address, -and throwing away older ones. -(Incrementing of request numbers etc. means that replies to older ones may no -longer be accepted.) -.P -Is it worth intercepting \fIincoming\fR packets, from the outside world, and -attempting tunnel setup based on them? -No, unless and until a way can be devised to initiate opportunistic encryption -to a non-opportunistic responder, -because -if the other end has not initiated tunnel setup itself, it will not be -prepared to do so at our request. -.R -Note, however, that most incoming packets will promptly be followed by -an outgoing packet in response! -Conceivably it might be useful to start early stages of negotiation, -at least as far as looking up information, -in response to an incoming packet. -.R -If a plaintext incoming packet indicates that the other -end is not prepared to do opportunistic encryption, -it might seem that this fact should be noted, to -avoid consuming resources and delaying -traffic in an attempt at opportunistic setup which is doomed to fail. -However, this would be a major security hole, -since the plaintext packet is not authenticated; -see section 2.5. -.NH 2 -Algorithm -.P -For clarity, -the following defers most discussion of error handling to the end. -.nr x \w'Step 3A.'u+1n -.de S -.IP "Step \\$1." \nxu -.. -.S 1 -Initiator does a DNS reverse lookup on the Destination address, -asking not for the usual PTR records, -but for TXT records. -Meanwhile, Initiator also sends a ping to the Destination, -to cause any other dynamic setup actions to start happening. -(Ping replies are disregarded; -the host might not be reachable with plaintext pings.) -.S 2A -If at least one suitable TXT record (see section 2.3) comes back, -each contains a potential Responder's IP address -and that Responder's public key (or where to find it). -Initiator picks one TXT record, based on priority (see 2.3), -thus picking a Responder. -If there was no public key in the TXT record, -the Initiator also starts a DNS lookup (as specified by the TXT record) -to get KEY records. -.S 2B -If no suitable TXT record is available, -and policy permits, -Initiator designates the Destination itself as the Responder -(see section 2.4). -If policy does not permit, -or the Destination is unresponsive to the negotiation, -then opportunistic encryption is not possible, -and Initiator gives up (see section 2.5). -.S 3 -If there already is a keying channel to the Responder's IP address, -the Initiator uses the existing keying channel; -skip to step 10. -Otherwise, the Initiator starts an IKE Phase 1 negotiation -(see section 2.7 for details) -with the Responder. -The address family of the Responder's IP address dictates whether -the keying channel and the outside of the tunnel should be IPv4 or IPv6. -.S 4 -Responder gets the first IKE message, -and responds. -It also starts a DNS reverse lookup on the Initiator's IP address, -for KEY records, on speculation. -.S 5 -Initiator gets Responder's reply, -and sends first message of IKE's D-H exchange (see 2.4). -.S 6 -Responder gets Initiator's D-H message, -and responds with a matching one. -.S 7 -Initiator gets Responder's D-H message; -encryption is now established, authentication remains to be done. -Initiator sends IKE authentication message, -with an FQDN identity if a reverse lookup on its address will not yield a -suitable KEY record. -(Note, an FQDN need not -actually correspond to a host\(eme.g., the DNS data for it need not -include an A record.) -.S 8 -Responder gets Initiator's authentication message. -If there is no identity included, -Responder waits for step 4's speculative DNS lookup to finish; -it should yield a suitable KEY record (see 2.3). -If there is an FQDN identity, -responder discards any data obtained from step 4's DNS lookup; -does a forward lookup on the FQDN, for a KEY record; -waits for that lookup to return; -it should yield a suitable KEY record. -Either way, Responder uses the KEY data to verify the message's hash. -Responder replies with an authentication message, -with an FQDN identity if a reverse lookup on its address will not yield a -suitable KEY record. -.S 9A -(If step 2A was used.) -The Initiator gets the Responder's authentication message. -Step 2A has provided a key (from the TXT record or via DNS lookup). -Verify message's hash. -Encrypted and authenticated keying channel established, -man-in-middle attack precluded. -.S 9B -(If step 2B was used.) -The Initiator gets the Responder's authentication message, -which must contain an FQDN identity (if the Responder can't put a TXT in his -reverse map he presumably can't do a KEY either). -Do forward lookup on the FQDN, -get suitable KEY record, verify hash. -Encrypted keying channel established, -man-in-middle attack precluded, -but authentication weak (see 2.4). -.S 10 -Initiator initiates IKE Phase 2 negotiation (see 2.7) to establish tunnel, -specifying Source and Destination identities as IP addresses (see 2.6). -The address family of those addresses also determines whether the inside -of the tunnel should be IPv4 or IPv6. -.S 11 -Responder gets first Phase 2 message. -Now the Responder finally knows what's going on! -Unless the specified Source is identical to the Initiator, -Responder initiates DNS reverse lookup on Source IP address, -for TXT records; -waits for result; -gets suitable TXT record(s) (see 2.3), -which should contain either the Initiator's IP address -or an FQDN identity identical to that supplied by the Initiator in step 7. -This verifies that the Initiator is authorized -to act as SG for the Source. -Responder replies with second Phase 2 message, -selecting acceptable details (see 2.7), -and establishes tunnel. -.S 12 -Initiator gets second Phase 2 message, -establishes tunnel (if he didn't already), -and releases the intercepted packet into it, finally. -.S 13 -Communication proceeds. -See section 3 for what happens later. -.P -As additional information becomes available, -notably in steps 1, 2, 4, 8, 9, 11, and 12, -there is always a possibility that local policy -(e.g., access limitations) might prevent further progress. -Whenever possible, -at least attempt to inform the other end of this. -.P -At any time, there is a possibility of the negotiation failing due to -unexpected responses, e.g. the Responder not responding at all -or rejecting all Initiator's proposals. -If multiple SGs were found as possible Responders, -the Initiator should try at least one more before giving up. -The number tried should be influenced by what the alternative is: -if the traffic will otherwise be discarded, trying the full list is -probably appropriate, -while if the alternative is plaintext transmission, -it might be based on how long the tries are taking. -The Initiator should try as many as it reasonably can, -ideally all of them. -.P -There is a sticky problem with timeouts. -If the Responder is down -or otherwise inaccessible, in the worst case we won't hear about this -except by not getting responses. -Some other, more pathological or even -evil, failure cases can have the same result. -The problem is that in the -case where plaintext is permitted, we want to decide whether a tunnel is -possible quickly. -There is no good solution to this, alas; -we just have to take the time and do it right. -(Passing plaintext meanwhile -looks attractive at first glance... but exposing -the first few seconds of a connection is often almost as bad as exposing -the whole thing. -Worse, if the user checks the status of the connection, -after that brief window it looks secure!) -.P -The flip side of waiting for a timeout is that all other forms of -feedback, e.g. ``host not reachable'', -arguably should be \fIignored\fR, -because in the absence of authenticated ICMP, -you cannot trust them! -.R -An alternative, sometimes suggested, to the use of explicit DNS records -for SG discovery is to directly attempt IKE negotiation with the -destination host, -and assume that any relevant SG will be on the packet path, -will intercept the IKE packets, -and will impersonate the destination host for the IKE negotiation. -This is superficially attractive but is a very bad idea. -It assumes that routing is stable throughout negotiation, -that the SG is on the plaintext-packets path, -and that the destination host is routable -(yes, it is possible to have (private) DNS data for an unroutable host). -Playing extra games in the plaintext-packet path hurts performance and -can be expected to be unpopular. -Various difficulties ensue when there are multiple SGs along the path -(there is already bad experience with this, in RSVP), -and the presence of even one can make it impossible -to do IKE direct to the host when that is what's wanted. -Worst of all, such impersonation breaks the IP network model badly, -making problems difficult to diagnose and impossible to work around -(and there is already bad experience with this, in areas like web caching). -.R -(Step 1.) -Dynamic setup actions might include establishment of demand-dialed links. -These might be present anywhere along the path, -so one cannot rely on out-of-band communication at the Initiator to -trigger them. -Hence the ping. -.R -(Step 2.) -In many cases, the IP address on the intercepted packet will be the -result of a name lookup just done. -Inverse queries, an obscure DNS feature from the distant past, -in theory can be used to ask a DNS server to reverse that lookup, -giving the name that produced the address. -This is not the same as a reverse lookup, -and the difference can matter a great deal in cases where a host -does not control its reverse map -(e.g., when the host's IP address is dynamically assigned). -Unfortunately, inverse queries were never widely implemented and -are now considered obsolete. -Phooey. -.A -Support for a small subset of this admittedly-obscure feature -would be useful. -Unfortunately, it seems unlikely. -.R -(Step 3.) -Using only IP addresses to decide whether there is already a relevant -keying channel avoids some -difficult problems. -In particular, it might seem that this should be based on identities, -but those are not known until very late in IKE Phase 1 negotiations. -.R -(Step 4.) -The DNS lookup is done on speculation -because the data will probably be useful and the lookup can be done -in parallel with IKE activity, -potentially speeding things up. -.R -(Steps 7 and 8.) -If an SG does not control its reverse map, -there is no way it can prove its right to use an IP address, -but it can nevertheless supply both an identity (as an FQDN) and -proof of its right to use that identity. -This is somewhat better than nothing, -and may be quite useful if the SG is representing a client host -which \fIcan\fR prove its right to \fIits\fR IP address. -(For example, a fixed-address subnet might live behind an SG with -a dynamically-assigned address; -such an SG has to be the Initiator, not the Responder, -so the subnet's TXT records can contain FQDN identities, -but with that restriction, this works.) -It might sound like this would permit some man-in-the-middle attacks -in important cases like Road Warrior, -but the RW can still do full authentication of the home base, -so a man in the middle cannot successfully impersonate home base, -and the D-H exchange doesn't work unless the man in the middle -impersonates \fIboth\fR ends. -.R -(Steps 7 and 8.) -Another situation where proof of the right to use an identity can be -very useful is when access is deliberately limited. -While opportunistic encryption is intended as a general-purpose -connection mechanism between strangers, -it may well be convenient for prearranged connections to use -the same mechanism. -.R -(Steps 7 and 8.) -FQDNs as identities are avoided where possible, -since they can involve synchronous DNS lookups. -.R -(Step 11.) -Note that only here, in Phase 2, -does the Responder actually learn who the -Source and Destination hosts are. -This unfortunately demands a synchronous DNS lookup to verify that the -Initiator is authorized to represent the Source, -unless they are one and the same. -This and the initial TXT lookup are the only synchronous DNS lookups -absolutely required by the algorithm, -and they appear to be unavoidable. -.R -While it might seem unlikely that a refusal to cooperate from one SG -could be remedied by trying another\(empresumably they all use the -same policies\(emit's conceivable that one might be misconfigured. -Preferably they should all be tried, -but it may be necessary to set some limits on this -if alternatives exist. -.NH 2 -DNS Records -.P -Gateway discovery and key lookup are based on TXT and KEY DNS records. -The TXT record specifies IP address or other identity of a host's SG, -and possibly supplies its public key as well, -while the KEY record supplies public keys not found in TXT records. -.NH 3 -TXT -.P -Opportunistic-encryption SG discovery uses TXT records with the content: -.DS -X-IPsec-Gateway(\fInnn\fR)=\fIiii\fR\ \fIkkk\fR -.DE -following RFC 1464 attribute/value -notation. -Records which -do not contain an ``='', -or which do not have exactly the specified form to the left of it, -are ignored. -(Near misses perhaps should be reported.) -.P -The \fInnn\fR is an unsigned integer which will fit in 16 bits, -specifying an MX-style preference -(lower number = stronger preference) to -control the order in which multiple SGs are tried. -If there are ties, pick one, -randomly enough that the choice will probably be different each time. -xxx rollover. -The preference field is not optional; -use ``0'' if there is no meaningful preference ordering. -.P -The \fIiii\fR part identifies the SG. -Normally this is a dotted-decimal IPv4 address or -a colon-hex IPv6 address. -The sole exception is if the SG has no fixed address (see 2.4) but -the host(s) behind it do, -in which case \fIiii\fR is of the form ``@fqdn'', -where \fIfqdn\fR is the FQDN that the SG will use to -identify itself (in step 7 of section 2.2); -such a record cannot be used for SG discovery by an Initiator, -but can be used for -SG verification (step 11 of 2.2) by a Responder. -.P -The \fIkkk\fR part is optional. -If it is present, -it is an RSA-MD5 public key in base-64 notation, as in the text -form of an RFC 2535 KEY record. -If it is not present, -this specifies that the public key can be found in a KEY -record located based on the SG's identification: -if \fIiii\fR is an IP address, -do a reverse lookup on that address, -else do a forward lookup on the FQDN. -.R -While it is unusual for a reverse lookup to go for records other than PTR -records (or possibly CNAME records, for RFC 2317 classless delegation), -there's no reason why it can't. -The TXT record is a temporary stand-in -for (we hope, someday) a new DNS record for SG identification and keying. -Keeping the setup process fast requires minimizing the number of DNS -lookups, hence the desire to put all the information in one place. -.R -The use of RFC 1464 notation avoids collisions with other uses of TXT -records. -The ``X-'' in the attribute name -indicates that this format is tentative and experimental; -this design will probably need modification after initial experiments. -The format is chosen with an eye on eventual binary encoding. -Note, in particular, -that the TXT record normally contains the \fIaddress\fR of the SG, -not (repeat, not) its name. -Name-to-address conversion is the job of -whatever generates the TXT record, -which is expected to be a program, not a human\(emthis is conceptually -a \fIbinary\fR record, temporarily using a text encoding. -The ``@fqdn'' form of the SG identity is -for specialized uses and is never mapped to an address. -.A -A DNS TXT record contains one or more character strings, -but RFC 1035 does not describe exactly how -a multi-string TXT record is interpreted. -This is relevant because a string can be at most 255 characters, -and public keys can exceed this. -Empirically, the standard pattern is that -each string which is -both less than 255 characters \fIand\fR not the final string of the -record should have a blank appended to it, -and the strings of the record -should then be concatenated. -(This observation is based on how BIND 8 transforms a TXT record -from text to DNS binary.) -.NH 3 -KEY -.P -An opportunistic-encryption KEY record -is an Authentication-permitted, -Entity (host), -non-Signatory, -IPsec, -RSA/MD5 record -(that is, its first four bytes are 0x42000401), -as per RFCs 2535 and 2537. -KEY records with other \fIflags\fR, \fIprotocol\fR, or \fIalgorithm\fR -values are ignored. -.R -Unfortunately, the public key has to be -associated with the SG, not the client host behind it. -The Responder does not know which client it is supposed to be representing, -or which client the Initiator is representing, -until far too late. -.A -Per-client keys would reduce vulnerability to key compromise, -and simplify key changes, -but they would require changes to IKE Phase 1, to separately identify -the SG and its initial client(s). -(At present, the client identities are not known to the Responder -until IKE Phase 2.) -While the current IKE standard does not actually specify (!) who is -being identified by identity payloads, -the overwhelming consensus is that they identify the SG, -and as seen earlier, -this has important uses. -.NH 3 -Summary -.P -For reference, the minimum set of DNS records needed to make this -all work is either: -.IP 1. \w'1.'u+2n -TXT in Destination reverse map, identifying Responder and providing public key. -.IP 2. -KEY in Initiator reverse map, providing public key. -.IP 3. -TXT in Source reverse map, verifying relationship to Initiator. -.P -or: -.IP 1. \w'1.'u+2n -TXT in Destination reverse map, identifying Responder. -.IP 2. -KEY in Responder reverse map, providing public key. -.IP 3. -KEY in Initiator reverse map, providing public key. -.IP 4. -TXT in Source reverse map, verifying relationship to Initiator. -.P -Slight complications ensue for dynamic addresses, -lack of control over reverse maps, etc. -.NH 3 -Implementation -.P -In the long run, we need either a tree of trust or a web of trust, -so we can trust our DNS data. -The obvious approach for DNS is a tree of trust, -but there are various practical problems with running all of this -through the root servers, -and a web of trust is arguably more robust anyway. -This is logically independent of opportunistic encryption, -and a separate design proposal will be prepared. -.P -Interim stages of implementation of this will require a bit of thought. -Notably, we need some way of dealing with the lack of fully signed DNSSEC -records right away. -Without user interaction, probably the best we can do is to -remember the results of old fetches, compare them to the results of new -fetches, and complain and disbelieve all of it if there's a mismatch. -This does mean that somebody who gets fake data into our very first fetch -will fool us, at least for a while, but that seems an acceptable tradeoff. -(Obviously there needs to be a way to manually flush the remembered results -for a specific host, to permit deliberate changes.) -.NH 2 -Responders Without Credentials -.P -In cases where the Destination simply does not control its -DNS reverse-map entries, -there is no verifiable way to determine a suitable SG. -This does not make communication utterly impossible, though. -.P -Simply attempting negotiation directly with the host is a last resort. -(An aggressive implementation might wish to attempt it in parallel, -rather than waiting until other options are known to be unavailable.) -In particular, in many cases involving dynamic addresses, it will work. -It has the disadvantage of delaying the discovery that opportunistic -encryption is entirely impossible, -but the case seems common enough to justify the overhead. -.P -However, there are policy issues here either way, because -it is possible to impersonate such a host. -The host can supply an FQDN identity and verify its right to use that -identity, -but except by prearrangement, -there is no way to verify that the FQDN is the right one for that -IP address. -(The data from forward lookups may be controlled by people -who do not own the address, so it cannot be trusted.) -The encryption is still solid, though, -so in many cases this may be useful. -.NH 2 -Failure of Opportunism -.P -When there is no way to do opportunistic encryption, a policy issue arises: -whether to put in a bypass (which allows plaintext traffic through) -or a block (which discards it, perhaps with notification back to the sender). -The choice is very much a matter of local policy, -and may depend on details such as the higher-level protocol being used. -For example, -an SG might well permit plaintext HTTP but forbid plaintext Telnet, -in which case \fIboth\fR a block and a bypass would be set up if -opportunistic encryption failed. -.P -A bypass/block must, in practice, -be treated much like an IPsec tunnel. -It should persist for a while, -so that high-overhead processing doesn't have to be done for every packet, -but should go away eventually to return resources. -It may be simplest to treat it as a degenerate tunnel. -It should have a relatively long lifetime (say 6h) to keep the frequency -of negotiation attempts down, -except in the case where the other SG simply did not respond to IKE packets, -where the lifetime should be short (say 10min) because -the other SG is presumably down and might come back up again. -(Cases where the other SG responded to IKE with unauthenticated error -reports like ``port unreachable'' are borderline, -and might deserve to be treated as an intermediate case: -while such reports cannot be trusted unreservedly, -in the absence of any other response, -they do give some reason to suspect that the other SG is unable or -unwilling to participate in opportunistic encryption.) -.P -As noted in section 2.1, one might think that -arrival of a plaintext incoming packet should cause a -bypass/block to be set up for its source host: -such a packet is almost always followed by an outgoing reply packet; -the incoming packet is clear evidence that opportunistic encryption is -not available at the other end; -attempting it will waste resources and delay traffic to no good purpose. -Unfortunately, this means that anyone out on the Internet -who can forge a source address can prevent encrypted communication! -Since their source addresses are not authenticated, -plaintext packets cannot be taken as evidence of anything, -except perhaps that communication from that host is likely to occur soon. -.P -There needs to be a way for local administrators to remove a bypass/block -ahead of its normal expiry time, -to force a retry after a problem at the other end is known to have been fixed. -.NH 2 -Subnet Opportunism -.P -In principle, when the Source or Destination host belongs to a subnet -and the corresponding SG is willing to provide tunnels to the whole subnet, -this should be done. -There is no extra overhead, -and considerable potential for avoiding later overhead if -similar communication occurs with other members of the subnet. -Unfortunately, -at the moment, -opportunistic tunnels can only have degenerate subnets (single hosts) -at their ends. -(This does, at least, set up the keying channel, -so that negotiations for tunnels to other hosts in the same subnets -will be considerably faster.) -.P -The crucial problem is step 11 of section 2.2: -the Responder must verify that the Initiator is authorized to represent -the Source, -and this is impossible for a subnet because -there is no way to do a reverse lookup on it. -Information in DNS -records for a name or a single address cannot be trusted, -because they may be controlled by people who do not control the whole subnet. -.A -Except in the special case of a subnet masked on a -byte boundary (in which case RFC 1035's convention of an incomplete -in-addr.arpa name could be used), subnet lookup would need extensions to the -reverse-map name space, perhaps along the lines of that commonly done for -RFC 2317 delegation. -IPv6 already has suitable name syntax, as in RFC 2874, -but has no specific provisions for subnet entries in its reverse maps. -Fixing all this is is not conceptually difficult, -but is logically independent of opportunistic encryption, -and will be proposed separately. -.P -A less-troublesome problem is that the Initiator, -in step 10 of 2.2, -must know exactly what subnet is present on the Responder's end -so he can propose a tunnel to it. -This information could be included in the TXT record -of the Destination -(it would have to be verified with a subnet lookup, -but that could be done in parallel with other operations). -The Initiator presumably -can be configured to know what subnet(s) are present on its end. -.NH 2 -Option Settings -.P -IPsec and IKE have far too many useless options, and a few useful ones. -IKE negotiation is quite simplistic, and cannot handle even simple -discrepancies between the two SGs. -So it is necessary to be quite specific about what should be done and -what should be proposed, -to guarantee interoperability without prearrangement or -other negotiation protocols. -.R -The prohibition of other negotiations is simply because there is no time. -The setup algorithm (section 2.2) is lengthy already. -.P -[Open question: -should opportunistic IKE use a different port than normal IKE?] -.P -Somewhat arbitrarily and -tentatively, opportunistic SGs must support Main Mode, Oakley group 5 for -D-H, 3DES encryption and MD5 authentication for both ISAKMP and IPsec SAs, -RSA/MD5 digital-signature authentication with keys between 2048 and 8192 bits, -and ESP doing both encryption and authentication. -They must do key PFS -in Quick Mode, but not identity PFS. -They may support IPComp, preferably using Deflate, -but must not insist on it. -They may support AES as an alternative to 3DES, -but must not insist on it. -.R -Identity PFS essentially requires establishing -a complete new keying channel for each new tunnel, -but key PFS just does a new Diffie-Hellman exchange for each rekeying, -which is relatively cheap. -.P -Keying channels must remain in existence at least as long as any -tunnel created with them remains (they are not costly, and keeping -the management path up and available simplifies various issues). -See section 3.1 for related issues. -Given the use of key PFS, -frequent rekeying does not seem critical here. -In the absence of strong reason to do otherwise, -the Initiator should propose rekeying at 8hr-or-1MB. -The Responder must accept any proposal which specifies -a rekeying time between 1hr and 24hr inclusive -and a rekeying volume between 100KB and 10MB inclusive. -.P -Given the short expected useful life of most tunnels (see section 3.1), -very few of them will survive long enough to be rekeyed. -In the absence of strong reason to do otherwise, -the Initiator should propose rekeying at 1hr-or-100MB. -The Responder must accept any proposal which specifies -a rekeying time between 10min and 8hr inclusive -and a rekeying volume between 1MB and 1000MB inclusive. -.P -It is highly desirable to add some random jitter -to the times of actual rekeying attempts, -to break up ``convoys'' of rekeying events; -this and certain other aspects of robust rekeying practice will be the subject -of a separate design proposal. -.R -The numbers used here for rekeying intervals are chosen quite arbitrarily -and should be re-assessed after some implementation experience is gathered. -.NH 1 -Renewal and Teardown -.NH 2 -Aging -.P -When to tear tunnels down is a bit problematic, but if we're setting up a -potentially unbounded number of them, -we have to tear them down \fIsomehow sometime\fR. -.P -Set a short initial tentative lifespan, say 1min, -since most net flows in fact last only a few seconds. -When that expires, look to see if -the tunnel is still in use (definition: -has had traffic, in either direction, -in the last half of the tentative lifespan). -If so, assign it a somewhat longer tentative lifespan, say 20min, -after which, look again. -If not, close it down. -(This tentative lifespan is -independent of rekeying; it is just the time when the tunnel's future -is next considered. -This should happen reasonably frequently, unlike -rekeying, which is costly and shouldn't be too frequent.) -Multi-step backoff algorithms are not worth the trouble; looking every -20min doesn't seem onerous. -.P -If the security gateway and the client host are one and the same, -tunnel teardown decisions might wish to pay attention to TCP connection status, -as reported by the local TCP layer. -A still-open -TCP connection is almost a guarantee that more traffic is coming, while -the demise of the only TCP connection through a tunnel is a strong hint -that none is. -If the SG and the client host are separate machines, -though, tracking TCP connection status requires packet snooping, -which is complicated and probably not worthwhile. -.P -IKE keying channels likewise are torn down when it appears the need has -passed. -They always linger longer than the last tunnel they administer, -in case they are needed again; the cost of retaining them is low. -Other than that, -unless the number of keying channels on the SG gets large, -the SG should simply retain all of them until rekeying time, -since rekeying is the only costly event. -When about to rekey a keying channel which has no current tunnels, -note when the last actual keying-channel traffic occurred, -and close the keying channel down if it wasn't in the last, say, 30min. -When rekeying a keying channel (or perhaps shortly before rekeying is expected), -Initiator and Responder should re-fetch the public keys used for -SG authentication, -against the possibility that they have changed or disappeared. -.P -See section 2.7 for discussion of rekeying intervals. -.P -Given the low user impact of tearing down and rebuilding a connection -(a tunnel or a keying channel), -rekeying attempts should not be too persistent: -one can always just rebuild when needed, -so heroic efforts to preserve an existing connection are unnecessary. -Say, try every 10s for a minute and every minute for 5min, -and then give up and declare the connection -(and all other connections to that IKE peer) dead. -.R -In future, more sophisticated, versions of this protocol, -examining the initial packet might permit a more intelligent guess at -the tunnel's useful life. -HTTP connections in particular are -notoriously bursty and repetitive. -.R -Note that rekeying a keying connection basically consists of building a -new keying connection from scratch, -using IKE Phase 1, -and abandoning the old one. -.NH 2 -Teardown and Cleanup -.P -Teardown should always be coordinated with the other end. -This means interpreting and sending Delete notifications. -.P -On receiving a Delete for the outbound SAs of a tunnel -(or some subset of them), -tear down the inbound ones too, and notify the other end -with a Delete. -Tunnels need to be considered as bidirectional entities, -even though the low-level protocols don't think of them that way. -.P -When the deletion is initiated locally, -rather than as a response to a received Delete, -send a Delete for (all) the inbound SAs of a tunnel. -If no responding Delete is received for the outbound SAs, -try re-sending the original Delete. -Three tries spaced 10s apart seems a reasonable level of effort. -(Indefinite persistence is not necessary; -whether the other end isn't cooperating because it doesn't feel like -it, or because it is down/disconnected/etc., -the problem will eventually be cleared up by other means.) -.P -After rekeying, -transmission should switch to using the new SAs (ISAKMP or IPsec) -immediately, -and the old leftover SAs should be cleared out promptly -(and Deletes sent) rather than waiting for them to expire. -This reduces clutter and minimizes confusion. -.P -Since there is only one keying channel per remote IP address, -the question of whether a Delete notification has appeared on a -``suitable'' keying channel does not arise. -.R -The pairing of Delete notifications effectively constitutes an -acknowledged Delete, which is highly desirable. -.NH 2 -Outages and Reboots -.P -Tunnels sometimes go down because the other -end crashes, or disconnects, or has a network link break, -and there is no notice of this in the general case. -(Even in the event of a crash and -successful reboot, other SGs don't hear about it unless the -rebooted SG has specific reason to talk to them immediately.) -Over-quick response to temporary network outages is undesirable... -but note that a tunnel can be torn -down and then re-established without any user-visible effect except -a pause in traffic, -whereas if one end does reboot, -the other end can't get packets to it \fIat all\fR (except via IKE) -until the situation is noticed. -So a bias toward quick response is appropriate, -even at the cost of occasional false alarms. -.P -Heartbeat mechanisms are somewhat unsatisfactory for this. -Unless they are very frequent, which causes other problems, -they do not detect the problem promptly. -.A -What is really wanted is authenticated ICMP. -This might be a case where public-key encryption/authentication -of network packets is the right thing to do, -despite the expense. -.P -In the absence of that, a two-part approach seems warranted. -.P -First, -when an SG receives an IPsec packet that is addressed to it, -and otherwise appears healthy, -but specifies an unknown SA and is from a host that the receiver currently -has no keying channel to, -the receiver must attempt to inform the sender -via an IKE Initial-Contact notification -(necessarily sent in plaintext, -since there is no suitable keying channel). -This must be severely rate-limited on \fIboth\fR ends; -one notification per SG pair per minute seems ample. -.P -Second, there is an obvious difficulty with this: -the Initial-Contact notification is unauthenticated -and cannot be trusted. -So it must be taken as a hint only: -there must be a way to confirm it. -.P -What is needed here is something that's desirable for -debugging and testing anyway: -an IKE-level ping mechanism. -Pinging direct at the IP level instead will not tell us about a -crash/reboot event. -Sending pings through tunnels has -various complications (they should stop at the far mouth of the tunnel -instead of going on to a subnet; they should not count against idle -timers; etc.). -What is needed is a continuity check on a keying channel. -(This could also be used as a heartbeat, -should that seem useful.) -.P -IKE Ping delivery need not be reliable, since the whole point of a ping is -simply to provoke an acknowledgement. -They should preferably be authenticated, -but it is not clear that this is absolutely necessary, -although if they are not they need -encryption plus a timestamp or a nonce, -to foil replay mischief. -How they are implemented is a secondary issue, -and a separate design proposal will be prepared. -.A -Some existing implementations are already using -(private) notify value 30000 (``LIKE_HELLO'') as ping -and (private) notify value 30002 (``SHUT_UP'') as ping reply. -.P -If an IKE Ping gets no response, try some (say 8) IP pings, -spaced a few seconds apart, to check IP connectivity; -if one comes back, try another IKE Ping; -if that gets no response, -the other end probably has rebooted, or otherwise been re-initialized, -and its tunnels and keying channel(s) should be torn down. -.P -In a similar vein, -giving limited rekeying persistence, -a short network outage could take some tunnels down without -disrupting others. -On receiving a packet for an unknown SA from a host that a keying -channel is currently open to, -send that host a Invalid-SPI notification for that SA. -xxx that's not what Invalid-SPI is for. -The other host can then tear down the half-torn-down tunnel, -and negotiate a new tunnel for the traffic -it presumably still wants to send. -.P -Finally, -it would be helpful if SGs made some attempt to deal intelligently -with crashes and reboots. -A deliberate shutdown should include an attempt to notify all other SGs -currently connected by keying channels, -using Deletes, -that communication is about to fail. -(Again, these will be taken as teardowns; -attempts by the other SGs to negotiate new tunnels as replacements -should be ignored at this point.) -And when possible, SGs should attempt to preserve information -about currently-connected SGs in non-volatile storage, -so that after a crash, -an Initial-Contact can be sent to previous partners to -indicate loss of all previously-established connections. -.NH 1 -Conclusions -.P -This design appears to achieve the objective of setting up encryption -with strangers. -The authentication aspects also seem adequately addressed if the -destination controls its reverse-map DNS entries -and the DNS data itself can be reliably authenticated -as having originated from the legitimate administrators of that -subnet/FQDN. -The authentication situation is less satisfactory when DNS is less helpful, -but it is difficult to see what else could be done about it. -.NH 1 -References -.P -[TBW] -.NH 1 -Appendix: Separate Design Proposals TBW -.IP \(bu \w'\(bu'u+2n -How can we build a web of trust with DNSSEC? -(See section 2.3.4.) -.IP \(bu -How can we extend DNS reverse lookups to permit reverse lookup -on a subnet? -(Both address and mask must appear in the name to be looked up.) -(See section 2.6.) -.IP \(bu -How can rekeying be done as robustly as possible? -(At least partly, this is just documenting current FreeS/WAN practice.) -(See section 2.7.) -.IP \(bu -How should IKE Pings be implemented? -(See section 3.3.) diff --git a/doc/performance.html b/doc/performance.html deleted file mode 100644 index 2258eeeda..000000000 --- a/doc/performance.html +++ /dev/null @@ -1,458 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="interop.html">Previous</A> -<A HREF="testing.html">Next</A> -<HR> -<H1><A name="performance">Performance of FreeS/WAN</A></H1> - The performance of FreeS/WAN is adequate for most applications. -<P>In normal operation, the main concern is the overhead for encryption, - decryption and authentication of the actual IPsec (<A href="glossary.html#ESP"> -ESP</A> and/or<A href="glossary.html#AH"> AH</A>) data packets. Tunnel - setup and rekeying occur so much less frequently than packet processing - that, in general, their overheads are not worth worrying about.</P> -<P>At startup, however, tunnel setup overheads may be significant. If - you reboot a gateway and it needs to establish many tunnels, expect - some delay. This and other issues for large gateways are discussed<A href="#biggate"> - below</A>.</P> -<H2><A name="pub.bench">Published material</A></H2> -<P>The University of Wales at Aberystwyth has done quite detailed speed - tests and put<A href="http://tsc.llwybr.org.uk/public/reports/SWANTIME/"> - their results</A> on the web.</P> -<P>Davide Cerri's<A href="http://www.linux.it/~davide/doc/"> thesis (in - Italian)</A> includes performance results for FreeS/WAN and for<A href="glossary.html#TLS"> - TLS</A>. He posted an<A href="http://lists.freeswan.org/pipermail/users/2001-December/006303.html"> - English summary</A> on the mailing list.</P> -<P>Steve Bellovin used one of AT&T Research's FreeS/WAN gateways as his - data source for an analysis of the cache sizes required for key - swapping in IPsec. Available as<A href="http://www.research.att.com/~smb/talks/key-agility.email.txt"> - text</A> or<A href="http://www.research.att.com/~smb/talks/key-agility.pdf"> - PDF slides</A> for a talk on the topic.</P> -<P>See also the NAI work mentioned in the next section.</P> -<H2><A name="perf.estimate">Estimating CPU overheads</A></H2> -<P>We can come up with a formula that roughly relates CPU speed to the - rate of IPsec processing possible. It is far from exact, but should be - usable as a first approximation.</P> -<P>An analysis of authentication overheads for high-speed networks, - including some tests using FreeS/WAN, is on the<A href="http://www.pgp.com/research/nailabs/cryptographic/adaptive-cryptographic.asp"> - NAI Labs site</A>. In particular, see figure 3 in this<A href="http://download.nai.com/products/media/pgp/pdf/acsa_final_report.pdf"> - PDF document</A>. Their estimates of overheads, measured in Pentium II - cycles per byte processed are:</P> -<TABLE align="center" border="1"><TBODY></TBODY> -<TR><TH></TH><TH>IPsec</TH><TH>authentication</TH><TH>encryption</TH><TH> -cycles/byte</TH></TR> -<TR><TD>Linux IP stack alone</TD><TD>no</TD><TD>no</TD><TD>no</TD><TD align="right"> -5</TD></TR> -<TR><TD>IPsec without crypto</TD><TD>yes</TD><TD>no</TD><TD>no</TD><TD align="right"> -11</TD></TR> -<TR><TD>IPsec, authentication only</TD><TD>yes</TD><TD>SHA-1</TD><TD>no</TD><TD -align="right">24</TD></TR> -<TR><TD>IPsec with encryption</TD><TD>yes</TD><TD>yes</TD><TD>yes</TD><TD -align="right">not tested</TD></TR> -</TABLE> -<P>Overheads for IPsec with encryption were not tested in the NAI work, - but Antoon Bosselaers'<A href="http://www.esat.kuleuven.ac.be/~bosselae/fast.html"> - web page</A> gives cost for his optimised Triple DES implementation as - 928 Pentium cycles per block, or 116 per byte. Adding that to the 24 - above, we get 140 cycles per byte for IPsec with encryption.</P> -<P>At 140 cycles per byte, a 140 MHz machine can handle a megabyte -- 8 - megabits -- per second. Speeds for other machines will be proportional - to this. To saturate a link with capacity C megabits per second, you - need a machine running at<VAR> C * 140/8 = C * 17.5</VAR> MHz.</P> -<P>However, that estimate is not precise. It ignores the differences - between:</P> -<UL> -<LI>NAI's test packets and real traffic</LI> -<LI>NAI's Pentium II cycles, Bosselaers' Pentium cycles, and your - machine's cycles</LI> -<LI>different 3DES implementations</LI> -<LI>SHA-1 and MD5</LI> -</UL> -<P>and does not account for some overheads you will almost certainly - have:</P> -<UL> -<LI>communication on the client-side interface</LI> -<LI>switching between multiple tunnels -- re-keying, cache reloading and - so on</LI> -</UL> -<P>so we suggest using<VAR> C * 25</VAR> to get an estimate with a bit - of a built-in safety factor.</P> -<P>This covers only IP and IPsec processing. If you have other loads on - your gateway -- for example if it is also working as a firewall -- then - you will need to add your own safety factor atop that.</P> -<P>This estimate matches empirical data reasonably well. For example, - Metheringham's tests, described<A href="#klips.bench"> below</A>, show - a 733 topping out between 32 and 36 Mbit/second, pushing data as fast - as it can down a 100 Mbit link. Our formula suggests you need at least - an 800 to handle a fully loaded 32 Mbit link. The two results are - consistent.</P> -<P>Some examples using this estimation method:</P> -<TABLE align="center" border="1"><TBODY></TBODY> -<TR><TH colspan="2">Interface</TH><TH colspan="3">Machine speed in MHz</TH> -</TR> -<TR><TH>Type</TH><TH>Mbit per -<BR> second</TH><TH>Estimate -<BR> Mbit*25</TH><TH>Minimum IPSEC gateway</TH><TH>Minimum with other - load -<P>(e.g. firewall)</P> -</TH></TR> -<TR><TD>DSL</TD><TD align="right">1</TD><TD align="right">25 MHz</TD><TD rowspan="2"> -whatever you have</TD><TD rowspan="2">133, or better if you have it</TD></TR> -<TR><TD>cable modem</TD><TD align="right">3</TD><TD align="right">75 MHz</TD> -</TR> -<TR><TD><STRONG>any link, light load</STRONG></TD><TD align="right"><STRONG> -5</STRONG></TD><TD align="right">125 MHz</TD><TD>133</TD><TD>200+,<STRONG> - almost any surplus machine</STRONG></TD></TR> -<TR><TD>Ethernet</TD><TD align="right">10</TD><TD align="right">250 MHz</TD><TD> -surplus 266 or 300</TD><TD>500+</TD></TR> -<TR><TD><STRONG>fast link, moderate load</STRONG></TD><TD align="right"><STRONG> -20</STRONG></TD><TD align="right">500 MHz</TD><TD>500</TD><TD>800+,<STRONG> - any current off-the-shelf PC</STRONG></TD></TR> -<TR><TD>T3 or E3</TD><TD align="right">45</TD><TD align="right">1125 MHz</TD><TD> -1200</TD><TD>1500+</TD></TR> -<TR><TD>fast Ethernet</TD><TD align="right">100</TD><TD align="right"> -2500 MHz</TD><TD align="center" colspan="2" rowspan="2">// not feasible - with 3DES in software on current machines //</TD></TR> -<TR><TD>OC3</TD><TD align="right">155</TD><TD align="right">3875 MHz</TD> -</TR> -</TABLE> -<P>Such an estimate is far from exact, but should be usable as minimum - requirement for planning. The key observations are:</P> -<UL> -<LI>older<STRONG> surplus machines</STRONG> are fine for IPsec gateways - at loads up to<STRONG> 5 megabits per second</STRONG> or so</LI> -<LI>a<STRONG> mid-range new machine</STRONG> can handle IPsec at rates - up to<STRONG> 20 megabits per second</STRONG> or more</LI> -</UL> -<H3><A name="perf.more">Higher performance alternatives</A></H3> -<P><A href="glossary.html#AES">AES</A> is a new US government block - cipher standard, designed to replace the obsolete<A href="glossary.html#DES"> - DES</A>. If FreeS/WAN using<A href="glossary.html#3DES"> 3DES</A> is - not fast enough for your application, the AES<A href="web.html#patch"> - patch</A> may help.</P> -<P>To date (March 2002) we have had only one<A href="http://lists.freeswan.org/pipermail/users/2002-February/007771.html"> - mailing list report</A> of measurements with the patch applied. It - indicates that, at least for the tested load on that user's network,<STRONG> - AES roughly doubles IPsec throughput</STRONG>. If further testing - confirms this, it may prove possible to saturate an OC3 link in - software on a high-end box.</P> -<P>Also, some work is being done toward support of<A href="compat.html#hardware"> - hardware IPsec acceleration</A> which might extend the range of - requirements FreeS/WAN could meet.</P> -<H3><A NAME="11_2_2">Other considerations</A></H3> -<P>CPU speed may be the main issue for IPsec performance, but of course - it isn't the only one.</P> -<P>You need good ethernet cards or other network interface hardware to - get the best performance. See this<A href="http://www.ethermanage.com/ethernet/ethernet.html"> - ethernet information</A> page and this<A href="http://www.scyld.com/diag"> - Linux network driver</A> page.</P> -<P>The current FreeS/WAN kernel code is largely single-threaded. It is - SMP safe, and will run just fine on a multiprocessor machine (<A href="compat.html#multiprocessor"> -discussion</A>), but the load within the kernel is not shared - effectively. This means that, for example to saturate a T3 -- which - needs about a 1200 MHz machine -- you cannot expect something like a - dual 800 to do the job.</P> -<P>On the other hand, SMP machines do tend to share loads well so -- - provided one CPU is fast enough for the IPsec work -- a multiprocessor - machine may be ideal for a gateway with a mixed load.</P> -<H2><A name="biggate">Many tunnels from a single gateway</A></H2> -<P>FreeS/WAN allows a single gateway machine to build tunnels to many - others. There may, however, be some problems for large numbers as - indicated in this message from the mailing list:</P> -<PRE>Subject: Re: Maximum number of ipsec tunnels? - Date: Tue, 18 Apr 2000 - From: "John S. Denker" <jsd@research.att.com> - -Christopher Ferris wrote: - ->> What are the maximum number ipsec tunnels FreeS/WAN can handle?? - -Henry Spencer wrote: - ->There is no particular limit. Some of the setup procedures currently ->scale poorly to large numbers of connections, but there are (clumsy) ->workarounds for that now, and proper fixes are coming. - -1) "Large" numbers means anything over 50 or so. I routinely run boxes -with about 200 tunnels. Once you get more than 50 or so, you need to worry -about several scalability issues: - -a) You need to put a "-" sign in syslogd.conf, and rotate the logs daily -not weekly. - -b) Processor load per tunnel is small unless the tunnel is not up, in which -case a new half-key gets generated every 90 seconds, which can add up if -you've got a lot of down tunnels. - -c) There's other bits of lore you need when running a large number of -tunnels. For instance, systematically keeping the .conf file free of -conflicts requires tools that aren't shipped with the standard freeswan -package. - -d) The pluto startup behavior is quadratic. With 200 tunnels, this eats up -several minutes at every restart. I'm told fixes are coming soon. - -2) Other than item (1b), the CPU load depends mainly on the size of the -pipe attached, not on the number of tunnels. -</PRE> -<P>It is worth noting that item (1b) applies only to repeated attempts - to re-key a data connection (IPsec SA, Phase 2) over an established - keying connection (ISAKMP SA, Phase 1). There are two ways to reduce - this overhead using settings in<A href="manpage.d/ipsec.conf.5.html"> - ipsec.conf(5)</A>:</P> -<UL> -<LI>set<VAR> keyingtries</VAR> to some small value to limit repetitions</LI> -<LI>set<VAR> keylife</VAR> to a short time so that a failing data - connection will be cleaned up when the keying connection is reset.</LI> -</UL> -<P>The overheads for establishing keying connections (ISAKMP SAs, Phase - 1) are lower because for these Pluto does not perform expensive - operations before receiving a reply from the peer.</P> -<P>A gateway that does a lot of rekeying -- many tunnels and/or low - settings for tunnel lifetimes -- will also need a lot of<A href="glossary.html#random"> - random numbers</A> from the random(4) driver.</P> -<H2><A name="low-end">Low-end systems</A></H2> -<P><EM>Even a 486 can handle a T1 line</EM>, according to this mailing - list message:</P> -<PRE>Subject: Re: linux-ipsec: IPSec Masquerade - Date: Fri, 15 Jan 1999 11:13:22 -0500 - From: Michael Richardson - -. . . A 486/66 has been clocked by Phil Karn to do -10Mb/s encryption.. that uses all the CPU, so half that to get some CPU, -and you have 5Mb/s. 1/3 that for 3DES and you get 1.6Mb/s....</PRE> -<P>and a piece of mail from project technical lead Henry Spencer:</P> -<PRE>Oh yes, and a new timing point for Sandy's docs... A P60 -- yes, a 60MHz -Pentium, talk about antiques -- running a host-to-host tunnel to another -machine shows an FTP throughput (that is, end-to-end results with a real -protocol) of slightly over 5Mbit/s either way. (The other machine is much -faster, the network is 100Mbps, and the ether cards are good ones... so -the P60 is pretty definitely the bottleneck.)</PRE> -<P>From the above, and from general user experience as reported on the - list, it seems clear that a cheap surplus machine -- a reasonable 486, - a minimal Pentium box, a Sparc 5, ... -- can easily handle a home - office or a small company connection using any of:</P> -<UL> -<LI>ADSL service</LI> -<LI>cable modem</LI> -<LI>T1</LI> -<LI>E1</LI> -</UL> -<P>If available, we suggest using a Pentium 133 or better. This should - ensure that, even under maximum load, IPsec will use less than half the - CPU cycles. You then have enough left for other things you may want on - your gateway -- firewalling, web caching, DNS and such.</P> -<H2><A name="klips.bench">Measuring KLIPS</A></H2> -<P>Here is some additional data from the mailing list.</P> -<PRE>Subject: FreeSWAN (specically KLIPS) performance measurements - Date: Thu, 01 Feb 2001 - From: Nigel Metheringham <Nigel.Metheringham@intechnology.co.uk> - -I've spent a happy morning attempting performance tests against KLIPS -(this is due to me not being able to work out the CPU usage of KLIPS so -resorting to the crude measurements of maximum throughput to give a -baseline to work out loading of a box). - -Measurements were done using a set of 4 boxes arranged in a line, each -connected to the next by 100Mbit duplex ethernet. The inner 2 had an -ipsec tunnel between them (shared secret, but I was doing measurements -when the tunnel was up and running - keying should not be an issue -here). The outer pair of boxes were traffic generators or traffic sink. - -The crypt boxes are Compaq DL380s - Uniprocessor PIII/733 with 256K -cache. They have 128M main memory. Nothing significant was running on -the boxes other than freeswan. The kernel was a 2.2.19pre7 patched -with freeswan and ext3. - -Without an ipsec tunnel in the chain (ie the 2 inner boxes just being -100BaseT routers), throughput (measured with ttcp) was between 10644 -and 11320 KB/sec - -With an ipsec tunnel in place, throughput was between 3268 and 3402 -KB/sec - -These measurements are for data pushed across a TCP link, so the -traffic on the wire between the 2 ipsec boxes would have been higher -than this.... - -vmstat (run during some other tests, so not affecting those figures) on -the encrypting box shows approx 50% system & 50% idle CPU - which I -don't believe at all. Interactive feel of the box was significantly -sluggish. - -I also tried running the kernel profiler (see man readprofile) during -test runs. - -A box doing primarily decrypt work showed basically nothing happening - -I assume interrupts were off. -A box doing encrypt work showed the following:- - Ticks Function Load - ~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~ - 956 total 0.0010 - 532 des_encrypt2 0.1330 - 110 MD5Transform 0.0443 - 97 kmalloc 0.1880 - 39 des_encrypt3 0.1336 - 23 speedo_interrupt 0.0298 - 14 skb_copy_expand 0.0250 - 13 ipsec_tunnel_start_xmit 0.0009 - 13 Decode 0.1625 - 11 handle_IRQ_event 0.1019 - 11 .des_ncbc_encrypt_end 0.0229 - 10 speedo_start_xmit 0.0188 - 9 satoa 0.0225 - 8 kfree 0.0118 - 8 ip_fragment 0.0121 - 7 ultoa 0.0365 - 5 speedo_rx 0.0071 - 5 .des_encrypt2_end 5.0000 - 4 _stext 0.0140 - 4 ip_fw_check 0.0035 - 2 rj_match 0.0034 - 2 ipfw_output_check 0.0200 - 2 inet_addr_type 0.0156 - 2 eth_copy_and_sum 0.0139 - 2 dev_get 0.0294 - 2 addrtoa 0.0143 - 1 speedo_tx_buffer_gc 0.0024 - 1 speedo_refill_rx_buf 0.0022 - 1 restore_all 0.0667 - 1 number 0.0020 - 1 net_bh 0.0021 - 1 neigh_connected_output 0.0076 - 1 MD5Final 0.0083 - 1 kmem_cache_free 0.0016 - 1 kmem_cache_alloc 0.0022 - 1 __kfree_skb 0.0060 - 1 ipsec_rcv 0.0001 - 1 ip_rcv 0.0014 - 1 ip_options_fragment 0.0071 - 1 ip_local_deliver 0.0023 - 1 ipfw_forward_check 0.0139 - 1 ip_forward 0.0011 - 1 eth_header 0.0040 - 1 .des_encrypt3_end 0.0833 - 1 des_decrypt3 0.0034 - 1 csum_partial_copy_generic 0.0045 - 1 call_out_firewall 0.0125 - -Hope this data is helpful to someone... however the lack of visibility -into the decrypt side makes things less clear</PRE> -<H2><A name="speed.compress">Speed with compression</A></H2> -<P>Another user reported some results for connections with and without - IP compression:</P> -<PRE>Subject: [Users] Speed with compression - Date: Fri, 29 Jun 2001 - From: John McMonagle <johnm@advocap.org> - -Did a couple tests with compression using the new 1.91 freeswan. - -Running between 2 sites with cable modems. Both using approximately -130 mhz pentium. - -Transferred files with ncftp. - -Compressed file was a 6mb compressed installation file. -Non compressed was 18mb /var/lib/rpm/packages.rpm - - Compressed vpn regular vpn -Compress file 42.59 kBs 42.08 kBs -regular file 110.84 kBs 41.66 kBs - -Load was about 0 either way. -Ping times were very similar a bit above 9 ms. - -Compression looks attractive to me.</PRE> - Later in the same thread, project technical lead Henry Spencer added: -<PRE>> is there a reason not to switch compression on? I have large gateway boxes -> connecting 3 connections, one of them with a measly DS1 link... - -Run some timing tests with and without, with data and loads representative -of what you expect in production. That's the definitive way to decide. -If compression is a net loss, then obviously, leave it turned off. If it -doesn't make much difference, leave it off for simplicity and hence -robustness. If there's a substantial gain, by all means turn it on. - -If both ends support compression and can successfully negotiate a -compressed connection (trivially true if both are FreeS/WAN 1.91), then -the crucial question is CPU cycles. - -Compression has some overhead, so one question is whether *your* data -compresses well enough to save you more CPU cycles (by reducing the volume -of data going through CPU-intensive encryption/decryption) than it costs -you. Last time I ran such tests on data that was reasonably compressible -but not deliberately contrived to be so, this generally was not true -- -compression cost extra CPU cycles -- so compression was worthwhile only if -the link, not the CPU, was the bottleneck. However, that was before the -slow-compression bug was fixed. I haven't had a chance to re-run those -tests yet, but it sounds like I'd probably see a different result. </PRE> - The bug he refers to was a problem with the compression libraries that - had us using C code, rather than assembler, for compression. It was - fixed before 1.91. -<H2><A name="methods">Methods of measuring</A></H2> -<P>If you want to measure the loads FreeS/WAN puts on a system, note - that tools such as top or measurements such as load average are - more-or-less useless for this. They are not designed to measure - something that does most of its work inside the kernel.</P> -<P>Here is a message from FreeS/WAN kernel programmer Richard Guy Briggs - on this:</P> -<PRE>> I have a batch of boxes doing Freeswan stuff. -> I want to measure the CPU loading of the Freeswan tunnels, but am -> having trouble seeing how I get some figures out... -> -> - Keying etc is in userspace so will show up on the per-process -> and load average etc (ie pluto's load) - -Correct. - -> - KLIPS is in the kernel space, and does not show up in load average -> I think also that the KLIPS per-packet processing stuff is running -> as part of an interrupt handler so it does not show up in the -> /proc/stat system_cpu or even idle_cpu figures - -It is not running in interrupt handler. It is in the bottom half. -This is somewhere between user context (careful, this is not -userspace!) and hardware interrupt context. - -> Is this correct, and is there any means of instrumenting how much the -> cpu is being loaded - I don't like the idea of a system running out of -> steam whilst still showing 100% idle CPU :-) - -vmstat seems to do a fairly good job, but use a running tally to get a -good idea. A one-off call to vmstat gives different numbers than a -running stat. To do this, put an interval on your vmstat command -line.</PRE> - and another suggestion from the same thread: -<PRE>Subject: Re: Measuring the CPU usage of Freeswan - Date: Mon, 29 Jan 2001 - From: Patrick Michael Kane <modus@pr.es.to> - -The only truly accurate way to accurately track FreeSWAN CPU usage is to use -a CPU soaker. You run it on an unloaded system as a benchmark, then start up -FreeSWAN and take the difference to determine how much FreeSWAN is eating. -I believe someone has done this in the past, so you may find something in -the FreeSWAN archives. If not, someone recently posted a URL to a CPU -soaker benchmark tool on linux-kernel.</PRE> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="interop.html">Previous</A> -<A HREF="testing.html">Next</A> -</BODY> -</HTML> diff --git a/doc/policygroups.html b/doc/policygroups.html deleted file mode 100644 index 6a507b1f6..000000000 --- a/doc/policygroups.html +++ /dev/null @@ -1,341 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="quickstart.html">Previous</A> -<A HREF="faq.html">Next</A> -<HR> -<H1><A NAME="4">How to Configure Linux FreeS/WAN with Policy Groups</A></H1> -<A NAME="policygroups"></A> -<H2><A NAME="4_1">What are Policy Groups?</A></H2> -<P><STRONG>Policy Groups</STRONG> are an elegant general mechanism to - configure FreeS/WAN. They are useful for many FreeS/WAN users.</P> -<P>In previous FreeS/WAN versions, you needed to configure each IPsec - connection explicitly, on both local and remote hosts. This could - become complex.</P> -<P>By contrast, Policy Groups allow you to set local IPsec policy for - lists of remote hosts and networks, simply by listing the hosts and - networks which you wish to have special treatment in one of several - Policy Group files. FreeS/WAN then internally creates the connections - needed to implement each policy.</P> -<P>In the next section we describe our five Base Policy Groups, which - you can use to configure IPsec in many useful ways. Later, we will show - you how to create an IPsec VPN using one line of configuration for each - remote host or network.</P> -<A NAME="builtin_policygroups"></A> -<H3><A NAME="4_1_1">Built-In Security Options</A></H3> -<P>FreeS/WAN offers these Base Policy Groups:</P> -<DL> -<DT>private</DT> -<DD> FreeS/WAN only communicates privately with the listed<A HREF="glossary.html#CIDR"> - CIDR</A> blocks. If needed, FreeS/WAN attempts to create a connection - opportunistically. If this fails, FreeS/WAN blocks communication. - Inbound blocking is assumed to be done by the firewall. FreeS/WAN - offers firewall hooks but no modern firewall rules to help with inbound - blocking.</DD> -<DT>private-or-clear</DT> -<DD> FreeS/WAN prefers private communication with the listed CIDR - blocks. If needed, FreeS/WAN attempts to create a connection - opportunistically. If this fails, FreeS/WAN allows traffic in the - clear.</DD> -<DT>clear-or-private</DT> -<DD> FreeS/WAN communicates cleartext with the listed CIDR blocks, but - also accepts inbound OE connection requests from them. Also known as<A HREF="glossary.html#passive.OE"> - passive OE (pOE)</A>, this policy may be used to create an<A HREF="glossary.html#responder"> - opportunistic responder</A>.</DD> -<DT>clear</DT> -<DD> FreeS/WAN only communicates cleartext with the listed CIDR blocks.</DD> -<DT>block</DT> -<DD>FreeS/WAN blocks traffic to and from and the listed CIDR blocks. - Inbound blocking is assumed to be done by the firewall. FreeS/WAN - offers firewall hooks but no modern firewall rules to help with inbound - blocking. -<!-- also called "blockdrop".--> -</DD> -</DL> -<A NAME="policy.group.notes"></A> -<P>Notes:</P> -<UL> -<LI>Base Policy Groups apply to communication with this host only.</LI> -<LI>The most specific rule (whether policy or pre-configured connection) - applies. This has several practical applications: -<UL> -<LI>If CIDR blocks overlap, FreeS/WAN chooses the most specific - applicable block.</LI> -<LI>This decision also takes into account any pre-configured connections - you may have.</LI> -<LI>If the most specific connection is a pre-configured connection, the - following procedure applies. If that connection is up, it will be used. - If it is routed, it will be brought up. If it is added, no action will - be taken.</LI> -</UL> -</LI> -<LI>Base Policy Groups are created using built-in connections. Details - in<A HREF="manpage.d/ipsec.conf.5.html"> man ipsec.conf</A>.</LI> -<LI>All Policy Groups are bidirectional.<A HREF="src/policy-groups-table.html"> - This chart</A> shows some technical details. FreeS/WAN does not support - one-way encryption, since it can give users a false sense of security.</LI> -</UL> -<H2><A NAME="4_2">Using Policy Groups</A></H2> -<P>The Base Policy Groups which build IPsec connections rely on - Opportunistic Encryption. To use the following examples, you must first - become OE-capable, as described in our<A HREF="quickstart.html#quickstart"> - quickstart guide</A>.<A NAME="example1"></A></P> -<H3><A NAME="4_2_1">Example 1: Using a Base Policy Group</A></H3> -<P>Simply place CIDR blocks (<A HREF="#dnswarning">names</A>, IPs or IP - ranges) in /etc/ipsec.d/policies/<VAR>[groupname]</VAR>, and reread the - policy group files.</P> -<P>For example, the<VAR> private-or-clear</VAR> policy tells FreeS/WAN - to prefer encrypted communication to the listed CIDR blocks. Failing - that, it allows talk in the clear.</P> -<P>To make this your default policy, place<A HREF="glossary.html#fullnet"> - fullnet</A> in the<VAR> private-or-clear</VAR> policy group file:</P> -<PRE> [root@xy root]# cat /etc/ipsec.d/policies/private-or-clear - # This file defines the set of CIDRs (network/mask-length) to which - # communication should be private, if possible, but in the clear otherwise. - .... - 0.0.0.0/0</PRE> -<P>and reload your policies with</P> -<PRE> ipsec auto --rereadgroups</PRE> -<P>Use<A HREF="quickstart.html#opp.test"> this test</A> to verify - opportunistic connections.</P> -<A NAME="example2"></A> -<H3><A NAME="4_2_2">Example 2: Defining IPsec Security Policy with - Groups</A></H3> -<P>Defining IPsec security policy with Base Policy Groups is like - creating a shopping list: just put CIDR blocks in the appropriate group - files. For example:</P> -<PRE> [root@xy root]# cd /etc/ipsec.d/policies - [root@xy policies]# cat private - 192.0.2.96/27 # The finance department - 192.0.2.192/29 # HR - 192.0.2.12 # HR gateway - irc.private.example.com # Private IRC server - - [root@xy policies]# cat private-or-clear - 0.0.0.0/0 # My default policy: try to encrypt. - - [root@xy policies]# cat clear - 192.0.2.18/32 # My POP3 server - 192.0.2.19/32 # My Web proxy - - [root@xy policies]# cat block - spamsource.example.com</PRE> -<P>To make these settings take effect, type:</P> -<PRE> ipsec auto --rereadgroups</PRE> -<P>Notes:</P> -<UL> -<LI>For opportunistic connection attempts to succeed, all participating - FreeS/WAN hosts and gateways must be configured for OE.</LI> -<LI>Examples 3 through 5 show how to implement a detailed<VAR> private</VAR> - policy.</LI> -<LI><A NAME="dnswarning"></A><FONT COLOR="RED"> Warning:</FONT> Using - DNS names in policy files and ipsec.conf can be tricky. If the name - does not resolve, the policy will not be implemented for that name. It - is therefore safer either to use IPs, or to put any critical names in - /etc/hosts. We plan to implement periodic DNS retry to help with this. -<BR> Names are resolved at FreeS/WAN startup, or when the policies are - reloaded. Unfortunately, name lookup can hold up the startup process. - If you have fast DNS servers, the problem may be less severe.</LI> -</UL> -<A HREF="example3"></A> -<H3><A NAME="4_2_3">Example 3: Creating a Simple IPsec VPN with the<VAR> - private</VAR> Group</A></H3> -<P>You can create an IPsec VPN between several hosts, with only one line - of configuration per host, using the<VAR> private</VAR> policy group.</P> -<P>First, use our<A HREF="quickstart.html"> quickstart guide</A> to set - up each participating host with a FreeS/WAN install and OE.</P> -<P>In one host's<VAR> /etc/ipsec.d/policies/private</VAR>, list the - peers to which you wish to protect traffic. For example:</P> -<PRE> [root@xy root]# cd /etc/ipsec.d/policies - [root@xy policies]# cat private - 192.0.2.9 # several hosts at example.com - 192.0.2.11 - 192.0.2.12 - irc.private.example.com -</PRE> -<P>Copy the<VAR> private</VAR> file to each host. Remove the local host, - and add the initial host.</P> -<PRE> scp2 /etc/ipsec.d/policies/private root@192.0.2.12:/etc/ipsec.d/policies/private</PRE> -<P>On each host, reread the policy groups with</P> -<PRE> ipsec auto --rereadgroups</PRE> -<P>That's it! You're configured.</P> -<P>Test by pinging between two hosts. After a second or two, traffic - should flow, and</P> -<PRE> ipsec eroute</PRE> -<P>should yield something like</P> -<PRE> 192.0.2.11/32 -> 192.0.2.8/32 => tun0x149f@192.0.2.8</PRE> -<P>where your host IPs are substituted for 192.0.2.11 and 192.0.2.8.</P> -<P>If traffic does not flow, there may be an error in your OE setup. - Revisit our<A HREF="quickstart.html"> quickstart guide</A>.</P> -<P>Our next two examples show you how to add subnets to this IPsec VPN.</P> -<A NAME="example4"></A> -<H3><A NAME="4_2_4">Example 4: New Policy Groups to Protect a Subnet</A></H3> -<P>To protect traffic to a subnet behind your FreeS/WAN gateway, you'll - need additional DNS records, and new policy groups. To set up the DNS, - see our<A HREF="quickstart.html#opp.gate"> quickstart guide</A>. To - create five new policy groups for your subnet, copy these connections - to<VAR> /etc/ipsec.conf</VAR>. Substitute your subnet's IPs for - 192.0.2.128/29.</P> -<PRE> -conn private-net - also=private # inherits settings (eg. auto=start) from built in conn - leftsubnet=192.0.2.128/29 # your subnet's IPs here - -conn private-or-clear-net - also=private-or-clear - leftsubnet=192.0.2.128/29 - -conn clear-or-private-net - also=clear-or-private - leftsubnet=192.0.2.128/29 - -conn clear-net - also=clear - leftsubnet=192.0.2.128/29 - -conn block-net - also=block - leftsubnet=192.0.2.128/29 -</PRE> -<P>Copy the gateway's files to serve as the initial policy group files - for the new groups:</P> -<PRE> - cp -p /etc/ipsec.d/policies/private /etc/ipsec.d/policies/private-net - cp -p /etc/ipsec.d/policies/private-or-clear /etc/ipsec.d/policies/private-or-clear-net - cp -p /etc/ipsec.d/policies/clear-or-private /etc/ipsec.d/policies/clear-or-private-net - cp -p /etc/ipsec.d/policies/clear /etc/ipsec.d/policies/clear-net - cp -p /etc/ipsec.d/policies/block /etc/ipsec.d/policies/block -</PRE> -<P><STRONG>Tip: Since a missing policy group file is equivalent to a - file with no entries, you need only create files for the connections - you'll use.</STRONG></P> -<P>To test one of your new groups, place the fullnet 0.0.0.0/0 in<VAR> - private-or-clear-net</VAR>. Perform the subnet test in<A HREF="quickstart.html#opp.test"> - our quickstart guide</A>. You should see a connection, and</P> -<PRE> ipsec eroute</PRE> -<P>should include an entry which mentions the subnet node's IP and the - OE test site IP, like this:</P> -<PRE> 192.0.2.131/32 -> 192.139.46.77/32 => tun0x149f@192.0.2.11</PRE> -<A HREF="example5"></A> -<H3><A NAME="4_2_5">Example 5: Adding a Subnet to the VPN</A></H3> -<P>Suppose you wish to secure traffic to a subnet 192.0.2.192/29 behind - a FreeS/WAN box 192.0.2.12.</P> -<P>First, add DNS entries to configure 192.0.2.12 as an opportunistic - gateway for that subnet. Instructions are in our<A HREF="quickstart.html#opp.gate"> - quickstart guide</A>. Next, create a<VAR> private-net</VAR> group on - 192.0.2.12 as described in<A HREF="#example4"> Example 4</A>.</P> -<P>On each other host, add the subnet 192.0.2.192/29 to<VAR> private</VAR> -, yielding for example</P> -<PRE> [root@xy root]# cd /etc/ipsec.d/policies - [root@xy policies]# cat private - 192.0.2.9 # several hosts at example.com - 192.0.2.11 - 192.0.2.12 # HR department gateway - 192.0.2.192/29 # HR subnet - irc.private.example.com -</PRE> -<P>and reread policy groups with</P> -<PRE> ipsec auto --rereadgroups</PRE> -<P>That's all the configuration you need.</P> -<P>Test your VPN by pinging from a machine on 192.0.2.192/29 to any - other host:</P> -<PRE> [root@192.0.2.194]# ping 192.0.2.11</PRE> -<P>After a second or two, traffic should flow, and</P> -<PRE> ipsec eroute</PRE> -<P>should yield something like</P> -<PRE> 192.0.2.11/32 -> 192.0.2.194/32 => tun0x149f@192.0.2.12 -</PRE> -<P>Key:</P> -<TABLE> -<TR><TD>1.</TD><TD>192.0.2.11/32</TD><TD>Local start point of the - protected traffic.</TD></TR> -<TR><TD>2.</TD><TD>192.0.2.194/32</TD><TD>Remote end point of the - protected traffic.</TD></TR> -<TR><TD>3.</TD><TD>192.0.2.12</TD><TD>Remote FreeS/WAN node (gateway or - host). May be the same as (2).</TD></TR> -<TR><TD>4.</TD><TD>[not shown]</TD><TD>Local FreeS/WAN node (gateway or - host), where you've produced the output. May be the same as (1).</TD></TR> -</TABLE> -<P>For additional assurance, you can verify with a packet sniffer that - the traffic is being encrypted.</P> -<P>Note</P> -<UL> -<LI>Because strangers may also connect via OE, this type of VPN may - require a stricter firewalling policy than a conventional VPN.</LI> -</UL> -<H2><A NAME="4_3">Appendix</A></H2> -<A NAME="hiddenconn"></A> -<H3><A NAME="4_3_1">Our Hidden Connections</A></H3> -<P>Our Base Policy Groups are created using hidden connections. These - are spelled out in<A HREF="manpage.d/ipsec.conf.5.html"> man ipsec.conf</A> - and defined in<VAR> /usr/local/lib/ipsec/_confread</VAR>.</P> -<A NAME="custom_policygroups"></A> -<H3><A NAME="4_3_2">Custom Policy Groups</A></H3> -<P>A policy group is built using a special connection description in<VAR> - ipsec.conf</VAR>, which:</P> -<UL> -<LI>is<STRONG> generic</STRONG>. It uses<VAR> - right=[%group|%opportunisticgroup]</VAR> rather than specific IPs. The - connection is cloned for every name or IP range listed in its Policy - Group file.</LI> -<LI>often has a<STRONG> failure rule</STRONG>. This rule, written<VAR> - failureshunt=[passthrough|drop|reject|none]</VAR>, tells FreeS/WAN what - to do with packets for these CIDRs if it fails to establish the - connection. Default is<VAR> none</VAR>.</LI> -</UL> -<P>To create a new group:</P> -<OL> -<LI>Create its connection definition in<VAR> ipsec.conf</VAR>.</LI> -<LI>Create a Policy Group file in<VAR> /etc/ipsec.d/policies</VAR> with - the same name as your connection.</LI> -<LI>Put a CIDR block in that file.</LI> -<LI>Reread groups with<VAR> ipsec auto --rereadgroups</VAR>.</LI> -<LI>Test:<VAR> ping</VAR> to activate any OE connection, and view - results with<VAR> ipsec eroute</VAR>.</LI> -</OL> -<A NAME="disable_oe"></A><A NAME="disable_policygroups"></A> -<H3><A NAME="4_3_3">Disabling Opportunistic Encryption</A></H3> -<P>To disable OE (eg. policy groups and packetdefault), cut and paste - the following lines to<VAR> /etc/ipsec.conf</VAR>:</P> -<PRE>conn block - auto=ignore - -conn private - auto=ignore - -conn private-or-clear - auto=ignore - -conn clear-or-private - auto=ignore - -conn clear - auto=ignore - -conn packetdefault - auto=ignore</PRE> -<P>Restart FreeS/WAN so that the changes take effect:</P> -<PRE> ipsec setup restart</PRE> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="quickstart.html">Previous</A> -<A HREF="faq.html">Next</A> -</BODY> -</HTML> diff --git a/doc/politics.html b/doc/politics.html deleted file mode 100644 index 5dd1e9f96..000000000 --- a/doc/politics.html +++ /dev/null @@ -1,1231 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="umltesting.html">Previous</A> -<A HREF="ipsec.html">Next</A> -<HR> -<H1><A name="politics">History and politics of cryptography</A></H1> -<P>Cryptography has a long and interesting history, and has been the - subject of considerable political controversy.</P> -<H2><A name="intro.politics">Introduction</A></H2> -<H3><A NAME="26_1_1">History</A></H3> -<P>The classic book on the history of cryptography is David Kahn's<A href="biblio.html#Kahn"> - The Codebreakers</A>. It traces codes and codebreaking from ancient - Egypt to the 20th century.</P> -<P>Diffie and Landau<A href="biblio.html#diffie"> Privacy on the Line: - The Politics of Wiretapping and Encryption</A> covers the history from - the First World War to the 1990s, with an emphasis on the US.</P> -<H4>World War II</H4> -<P>During the Second World War, the British "Ultra" project achieved one - of the greatest intelligence triumphs in the history of warfare, - breaking many Axis codes. One major target was the Enigma cipher - machine, a German device whose users were convinced it was unbreakable. - The American "Magic" project had some similar triumphs against Japanese - codes.</P> -<P>There are many books on this period. See our bibliography for - several. Two I particularly like are:</P> -<UL> -<LI>Andrew Hodges has done a superb<A href="http://www.turing.org.uk/book/"> - biography</A> of Alan Turing, a key player among the Ultra - codebreakers. Turing was also an important computer pioneer. The terms<A -href="http://www.abelard.org/turpap/turpap.htm"> Turing test</A> and<A href="http://plato.stanford.edu/entries/turing-machine/"> - Turing machine</A> are named for him, as is the<A href="http://www.acm.org"> - ACM</A>'s highest technical<A href="http://www.acm.org/awards/taward.html"> - award</A>.</LI> -<LI>Neal Stephenson's<A href="biblio.html#neal"> Cryptonomicon</A> is a - novel with cryptography central to the plot. Parts of it take place - during WW II, other parts today.</LI> -</UL> -<P>Bletchley Park, where much of the Ultra work was done, now has a - museum and a<A href="http://www.bletchleypark.org.uk/"> web site</A>.</P> -<P>The Ultra work introduced three major innovations.</P> -<UL> -<LI>The first break of Enigma was achieved by Polish Intelligence in - 1931. Until then most code-breakers had been linguists, but a different - approach was needed to break machine ciphers. Polish Intelligence - recruited bright young mathematicians to crack the "unbreakable" - Enigma. When war came in 1939, the Poles told their allies about this, - putting Britain on the road to Ultra. The British also adopted a - mathematical approach.</LI> -<LI>Machines were extensively used in the attacks. First the Polish - "Bombe" for attacking Enigma, then British versions of it, then - machines such as Collosus for attacking other codes. By the end of the - war, some of these machines were beginning to closely resemble digital - computers. After the war, a team at Manchester University, several old - Ultra hands included, built one of the world's first actual - general-purpose digital computers.</LI> -<LI>Ultra made codebreaking a large-scale enterprise, producing - intelligence on an industrial scale. This was not a "black chamber", - not a hidden room in some obscure government building with a small crew - of code-breakers. The whole operation -- from wholesale interception of - enemy communications by stations around the world, through large-scale - code-breaking and analysis of the decrypted material (with an enormous - set of files for cross-referencing), to delivery of intelligence to - field commanders -- was huge, and very carefully managed.</LI> -</UL> -<P>So by the end of the war, Allied code-breakers were expert at - large-scale mechanised code-breaking. The payoffs were enormous.</P> -<H4><A name="postwar">Postwar and Cold War</A></H4> -<P>The wartime innovations were enthusiastically adopted by post-war and - Cold War signals intelligence agencies. Presumably many nations now - have some agency capable of sophisticated attacks on communications - security, and quite a few engage in such activity on a large scale.</P> -<P>America's<A href="glossary.html#NSA"> NSA</A>, for example, is said - to be both the world's largest employer of mathematicians and the - world's largest purchaser of computer equipment. Such claims may be - somewhat exaggerated, but beyond doubt the NSA -- and similar agencies - in other countries -- have some excellent mathematicians, lots of - powerful computers, sophisticated software, and the organisation and - funding to apply them on a large scale. Details of the NSA budget are - secret, but there are some published<A href="http://www.fas.org/irp/nsa/nsabudget.html"> - estimates</A>.</P> -<P>Changes in the world's communications systems since WW II have - provided these agencies with new targets. Cracking the codes used on an - enemy's military or diplomatic communications has been common practice - for centuries. Extensive use of radio in war made large-scale attacks - such as Ultra possible. Modern communications make it possible to go - far beyond that. Consider listening in on cell phones, or intercepting - electronic mail, or tapping into the huge volumes of data on new media - such as fiber optics or satellite links. None of these targets existed - in 1950. All of them can be attacked today, and almost certainly are - being attacked.</P> -<P>The Ultra story was not made public until the 1970s. Much of the - recent history of codes and code-breaking has not been made public, and - some of it may never be. Two important books are:</P> -<UL> -<LI>Bamford's<A href="biblio.html#puzzle"> The Puzzle Palace</A>, a - history of the NSA</LI> -<LI>Hager's<A href="http://www.fas.org/irp/eprint/sp/index.html"> Secret - Power</A>, about the<A href="http://sg.yahoo.com/government/intelligence/echelon_network/"> - Echelon</A> system -- the US, UK, Canada, Australia and New Zealand - co-operating to monitor much of the world's communications.</LI> -</UL> -<P>Note that these books cover only part of what is actually going on, - and then only the activities of nations open and democratic enough that - (some of) what they are doing can be discovered. A full picture, - including:</P> -<UL> -<LI>actions of the English-speaking democracies not covered in those - books</LI> -<LI>actions of other more-or-less sane governments</LI> -<LI>the activities of various more-or-less insane governments</LI> -<LI>possibilities for unauthorized action by government employees</LI> -<LI>possible actions by large non-government organisations: - corporations, criminals, or conspiracies</LI> -</UL> -<P>might be really frightening.</P> -<H4><A name="recent">Recent history -- the crypto wars</A></H4> -<P>Until quite recently, cryptography was primarily a concern of - governments, especially of the military, of spies, and of diplomats. - Much of it was extremely secret.</P> -<P>In recent years, that has changed a great deal. With computers and - networking becoming ubiquitous, cryptography is now important to almost - everyone. Among the developments since the 1970s:</P> -<UL> -<LI>The US gov't established the Data Encryption Standard,<A href="glossary.html#DES"> - DES</A>, a<A href="glossary.html#block"> block cipher</A> for - cryptographic protection of unclassfied documents.</LI> -<LI>DES also became widely used in industry, especially regulated - industries such as banking.</LI> -<LI>Other nations produced their own standards, such as<A href="glossary.html#GOST"> - GOST</A> in the Soviet Union.</LI> -<LI><A href="glossary.html#public">Public key</A> cryptography was - invented by Diffie and Hellman.</LI> -<LI>Academic conferences such as<A href="http://www-cse.ucsd.edu/users/mihir/crypto2k.html"> - Crypto</A> and<A href="http://www.esat.kuleuven.ac.be/cosic/eurocrypt2000/"> - Eurocrypt</A> began.</LI> -<LI>Several companies began offerring cryptographic products:<A href="glossary.html#RSAco"> - RSA</A>,<A href="glossary.html#PGPI"> PGP</A>, the many vendors with<A href="glossary.html#PKI"> - PKI</A> products, ...</LI> -<LI>Cryptography appeared in other products: operating systems, word - processors, ...</LI> -<LI>Network protocols based on crypto were developed:<A href="glossary.html#SSH"> - SSH</A>,<A href="glossary.html#SSL"> SSL</A>,<A href="glossary.html#IPsec"> - IPsec</A>, ...</LI> -<LI>Crytography came into widespread use to secure bank cards, - terminals, ...</LI> -<LI>The US government replaced<A href="glossary.html#DES"> DES</A> with - the much stronger Advanced Encryption Standard,<A href="glossary.html#AES"> - AES</A></LI> -</UL> -<P>This has led to a complex ongoing battle between various mainly - government groups wanting to control the spread of crypto and various - others, notably the computer industry and the<A href="http://online.offshore.com.ai/security/"> - cypherpunk</A> crypto advocates, wanting to encourage widespread use.</P> -<P>Steven Levy has written a fine history of much of this, called<A href="biblio.html#crypto"> - Crypto: How the Code rebels Beat the Government -- Saving Privacy in - the Digital Age</A>.</P> -<P>The FreeS/WAN project is to a large extent an outgrowth of cypherpunk - ideas. Our reasons for doing the project can be seen in these quotes - from the<A href="http://www.eff.org/pub/Privacy/Crypto_misc/cypherpunk.manifesto"> - Cypherpunk Manifesto</A>:</P> -<BLOCKQUOTE> Privacy is necessary for an open society in the electronic - age. ... -<P>We cannot expect governments, corporations, or other large, faceless - organizations to grant us privacy out of their beneficence. It is to - their advantage to speak of us, and we should expect that they will - speak. ...</P> -<P>We must defend our own privacy if we expect to have any. ...</P> -<P>Cypherpunks write code. We know that someone has to write software to - defend privacy, and since we can't get privacy unless we all do, we're - going to write it. We publish our code so that our fellow Cypherpunks - may practice and play with it. Our code is free for all to use, - worldwide. We don't much care if you don't approve of the software we - write. We know that software can't be destroyed and that a widely - dispersed system can't be shut down.</P> -<P>Cypherpunks deplore regulations on cryptography, for encryption is - fundamentally a private act. ...</P> -<P>For privacy to be widespread it must be part of a social contract. - People must come and together deploy these systems for the common good. - ...</P> -</BLOCKQUOTE> -<P>To quote project leader John Gilmore:</P> -<BLOCKQUOTE> We are literally in a race between our ability to build and - deploy technology, and their ability to build and deploy laws and - treaties. Neither side is likely to back down or wise up until it has - definitively lost the race.</BLOCKQUOTE> -<P>If FreeS/WAN reaches its goal of making<A href="intro.html#opp.intro"> - opportunistic encryption</A> widespread so that secure communication - can become the default for a large part of the net, we will have struck - a major blow.</P> -<H3><A name="intro.poli">Politics</A></H3> -<P>The political problem is that nearly all governments want to monitor - their enemies' communications, and some want to monitor their citizens. - They may be very interested in protecting some of their own - communications, and often some types of business communication, but not - in having everyone able to communicate securely. They therefore attempt - to restrict availability of strong cryptography as much as possible.</P> -<P>Things various governments have tried or are trying include:</P> -<UL> -<LI>Echelon, a monitor-the-world project of the US, UK, NZ, Australian - and Canadian<A href="glossary.html#SIGINT"> signals intelligence</A> - agencies. See this<A href="http://sg.yahoo.com/government/intelligence/echelon_network/"> - collection</A> of links and this<A href="http://www.zdnet.com/zdnn/stories/news/0,4586,2640682,00.html"> - story</A> on the French Parliament's reaction.</LI> -<LI>Others governments may well have their own Echelon-like projects. To - quote the Dutch Minister of Defense, as reported in a German<A href="http://www.heise.de/tp/english/inhalt/te/4729/1.html"> - magazine</A>:<BLOCKQUOTE> The government believes not only the - governments associated with Echelon are able to intercept communication - systems, but that it is an activity of the investigative authorities - and intelligence services of many countries with governments of - different political signature.</BLOCKQUOTE> Even if they have nothing - on the scale of Echelon, most intelligence agencies and police forces - certainly have some interception capability.</LI> -<LI><A href="glossary.html#NSA">NSA</A> tapping of submarine - communication cables, described in<A href="http://www.zdnet.com/zdnn/stories/news/0,4586,2764372,00.html"> - this article</A></LI> -<LI>A proposal for international co-operation on<A href="http://www.heise.de/tp/english/special/enfo/4306/1.html"> - Internet surveillance</A>.</LI> -<LI>Alleged<A href="http://cryptome.org/nsa-sabotage.htm"> sabotage</A> - of security products by the<A href="glossary.html#NSA"> NSA</A> (the US - signals intelligence agency).</LI> -<LI>The German armed forces and some government departments will stop - using American software for fear of NSA "back doors", according to this<A -href="http://www.theregister.co.uk/content/4/17679.html"> news story</A> -.</LI> -<LI>The British Regulation of Investigatory Powers bill. See this<A href="http://www.fipr.org/rip/index.html"> - web page.</A> and perhaps this<A href="http://ars.userfriendly.org/cartoons/?id=20000806&mode=classic"> - cartoon</A>.</LI> -<LI>A Russian<A href="http://www.eff.org/pub/Privacy/Foreign_and_local/Russia/russian_crypto_ban_english.edict"> - ban</A> on cryptography</LI> -<LI>Chinese<A href="http://www.eff.org/pub/Misc/Publications/Declan_McCullagh/www/global/china"> - controls</A> on net use.</LI> -<LI>The FBI's carnivore system for covert searches of email. See this<A href="http://www.zdnet.com/zdnn/stories/news/0,4586,2601502,00.html"> - news coverage</A> and this<A href="http://www.crypto.com/papers/carnivore-risks.html"> - risk assessment</A>. The government had an external review of some - aspects of this system done. See this<A href="http://www.crypto.com/papers/carnivore_report_comments.html"> - analysis</A> of that review. Possible defenses against Carnivore - include: -<UL> -<LI><A href="glossary.html#PGP">PGP</A> for end-to-end mail encryption</LI> -<LI><A href="http://www.home.aone.net.au/qualcomm/">secure sendmail</A> - for server-to-server encryption</LI> -<LI>IPsec encryption on the underlying IP network</LI> -</UL> -</LI> -<LI>export laws restricting strong cryptography as a munition. See<A href="#exlaw"> - discussion</A> below.</LI> -<LI>various attempts to convince people that fundamentally flawed - cryptography, such as encryption with a<A href="#escrow"> back door</A> - for government access to data or with<A href="#shortkeys"> inadequate - key lengths</A>, was adequate for their needs.</LI> -</UL> -<P>Of course governments are by no means the only threat to privacy and - security on the net. Other threats include:</P> -<UL> -<LI>industrial espionage, as for example in this<A href="http://www.zdnet.com/zdnn/stories/news/0,4586,2626931,00.html"> - news story</A></LI> -<LI>attacks by organised criminals, as in this<A href="http://www.sans.org/newlook/alerts/NTE-bank.htm"> - large-scale attack</A></LI> -<LI>collection of personal data by various companies. -<UL> -<LI>for example, consider the various corporate winners of Privacy - International's<A href="http://www.privacyinternational.org/bigbrother/"> - Big Brother Awards</A>.</LI> -<LI><A href="http://www.zeroknowledge.com">Zero Knowledge</A> sell tools - to defend against this</LI> -</UL> -</LI> -<LI>individuals may also be a threat in a variety of ways and for a - variety of reasons</LI> -<LI>in particular, an individual with access to government or industry - data collections could do considerable damage using that data in - unauthorized ways.</LI> -</UL> -<P>One<A href="http://www.zdnet.com/zdnn/stories/news/0,4586,2640674,00.html"> - study</A> enumerates threats and possible responses for small and - medium businesses. VPNs are a key part of the suggested strategy.</P> -<P>We consider privacy a human right. See the UN's<A href="http://www.un.org/Overview/rights.html"> - Universal Declaration of Human Rights</A>, article twelve:</P> -<BLOCKQUOTE> No one shall be subjected to arbitrary interference with - his privacy, family, home or correspondence, nor to attacks upon his - honor and reputation. Everyone has the right to the protection of the - law against such interference or attacks.</BLOCKQUOTE> -<P>Our objective is to help make privacy possible on the Internet using - cryptography strong enough not even those well-funded government - agencies are likely to break it. If we can do that, the chances of - anyone else breaking it are negliible.</P> -<H3><A NAME="26_1_3">Links</A></H3> -<P>Many groups are working in different ways to defend privacy on the - net and elsewhere. Please consider contributing to one or more of these - groups:</P> -<UL> -<LI>the EFF's<A href="http://www.eff.org/crypto/"> Privacy Now!</A> - campaign</LI> -<LI>the<A href="http://www.gilc.org"> Global Internet Liberty Campaign</A> -</LI> -<LI><A href="http://www.cpsr.org/program/privacy/privacy.html">Computer - Professionals for Social Responsibility</A></LI> -</UL> -<P>For more on these issues see:</P> -<UL> -<LI>Steven Levy (Newsweek's chief technology writer and author of the - classic "Hackers") new book<A href="biblio.html#crypto"> Crypto: How - the Code Rebels Beat the Government--Saving Privacy in the Digital Age</A> -</LI> -<LI>Simson Garfinkel (Boston Globe columnist and author of books on<A href="biblio.html#PGP"> - PGP</A> and<A href="biblio.html#practical"> Unix Security</A>) book<A href="biblio.html#Garfinkel"> - Database Nation: the death of privacy in the 21st century</A></LI> -</UL> -<P>There are several collections of<A href="web.html#quotes"> crypto - quotes</A> on the net.</P> -<P>See also the<A href="biblio.html"> bibliography</A> and our list of<A href="web.html#policy"> - web references</A> on cryptography law and policy.</P> -<H3><A NAME="26_1_4">Outline of this section</A></H3> -<P>The remainder of this section includes two pieces of writing by our - project leader</P> -<UL> -<LI>his<A href="#gilmore"> rationale</A> for starting this</LI> -<LI>another<A href="#policestate"> discussion</A> of project goals</LI> -</UL> -<P>and discussions of:</P> -<UL> -<LI><A href="#desnotsecure">why we do not use DES</A></LI> -<LI><A href="#exlaw">cryptography export laws</A></LI> -<LI>why<A href="#escrow"> government access to keys</A> is not a good - idea</LI> -<LI>the myth that<A href="#shortkeys"> short keys</A> are adequate for - some security requirements</LI> -</UL> -<P>and a section on<A href="#press"> press coverage of FreeS/WAN</A>.</P> -<H2><A name="leader">From our project leader</A></H2> -<P>FreeS/WAN project founder John Gilmore wrote a web page about why we - are doing this. The version below is slightly edited, to fit this - format and to update some links. For a version without these edits, see - his<A href="http://www.toad.com/gnu/"> home page</A>.</P> -<CENTER> -<H3><A name="gilmore">Swan: Securing the Internet against Wiretapping</A> -</H3> -</CENTER> -<P>My project for 1996 was to<B> secure 5% of the Internet traffic - against passive wiretapping</B>. It didn't happen in 1996, so I'm still - working on it in 1997, 1998, and 1999! If we get 5% in 1999 or 2000, we - can secure 20% the next year, against both active and passive attacks; - and 80% the following year. Soon the whole Internet will be private and - secure. The project is called S/WAN or S/Wan or Swan for Secure Wide - Area Network; since it's free software, we call it FreeSwan to - distinguish it from various commercial implementations.<A href="http://www.rsa.com/rsa/SWAN/"> - RSA</A> came up with the term "S/WAN". Our main web site is at<A href="http://www.freeswan.org/"> - http://www.freeswan.org/</A>. Want to help?</P> -<P>The idea is to deploy PC-based boxes that will sit between your local - area network and the Internet (near your firewall or router) which - opportunistically encrypt your Internet packets. Whenever you talk to a - machine (like a Web site) that doesn't support encryption, your traffic - goes out "in the clear" as usual. Whenever you connect to a machine - that does support this kind of encryption, this box automatically - encrypts all your packets, and decrypts the ones that come in. In - effect, each packet gets put into an "envelope" on one side of the net, - and removed from the envelope when it reaches its destination. This - works for all kinds of Internet traffic, including Web access, Telnet, - FTP, email, IRC, Usenet, etc.</P> -<P>The encryption boxes are standard PC's that use freely available - Linux software that you can download over the Internet or install from - a cheap CDROM.</P> -<P>This wasn't just my idea; lots of people have been working on it for - years. The encryption protocols for these boxes are called<A href="glossary.html#IPsec"> - IPSEC (IP Security)</A>. They have been developed by the<A href="http://www.ietf.cnri.reston.va.us/html.charters/ipsec-charter.html"> - IP Security Working Group</A> of the<A href="http://www.ietf.org/"> - Internet Engineering Task Force</A>, and will be a standard part of the - next major version of the Internet protocols (<A href="http://playground.sun.com/pub/ipng/html/ipng-main.html"> -IPv6</A>). For today's (IP version 4) Internet, they are an option.</P> -<P>The<A href="http://www.iab.org/iab"> Internet Architecture Board</A> - and<A href="http://www.ietf.org/"> Internet Engineering Steering Group</A> - have taken a<A href="iab-iesg.stmt"> strong stand</A> that the Internet - should use powerful encryption to provide security and privacy. I think - these protocols are the best chance to do that, because they can be - deployed very easily, without changing your hardware or software or - retraining your users. They offer the best security we know how to - build, using the Triple-DES, RSA, and Diffie-Hellman algorithms.</P> -<P>This "opportunistic encryption box" offers the "fax effect". As each - person installs one for their own use, it becomes more valuable for - their neighbors to install one too, because there's one more person to - use it with. The software automatically notices each newly installed - box, and doesn't require a network administrator to reconfigure it. - Instead of "virtual private networks" we have a "REAL private network"; - we add privacy to the real network instead of layering a - manually-maintained virtual network on top of an insecure Internet.</P> -<H4>Deployment of IPSEC</H4> -<P>The US government would like to control the deployment of IP Security - with its<A href="#exlaw"> crypto export laws</A>. This isn't a problem - for my effort, because the cryptographic work is happening outside the - United States. A foreign philanthropist, and others, have donated the - resources required to add these protocols to the Linux operating - system.<A href="http://www.linux.org/"> Linux</A> is a complete, freely - available operating system for IBM PC's and several kinds of - workstation, which is compatible with Unix. It was written by Linus - Torvalds, and is still maintained by a talented team of expert - programmers working all over the world and coordinating over the - Internet. Linux is distributed under the<A href="glossary.html#GPL"> - GNU Public License</A>, which gives everyone the right to copy it, - improve it, give it to their friends, sell it commercially, or do just - about anything else with it, without paying anyone for the privilege.</P> -<P>Organizations that want to secure their network will be able to put - two Ethernet cards into an IBM PC, install Linux on it from a $30 CDROM - or by downloading it over the net, and plug it in between their - Ethernet and their Internet link or firewall. That's all they'll have - to do to encrypt their Internet traffic everywhere outside their own - local area network.</P> -<P>Travelers will be able to run Linux on their laptops, to secure their - connection back to their home network (and to everywhere else that they - connect to, such as customer sites). Anyone who runs Linux on a - standalone PC will also be able to secure their network connections, - without changing their application software or how they operate their - computer from day to day.</P> -<P>There will also be numerous commercially available firewalls that use - this technology.<A href="http://www.rsa.com/"> RSA Data Security</A> is - coordinating the<A href="http://www.rsa.com/rsa/SWAN"> S/Wan (Secure - Wide Area Network)</A> project among more than a dozen vendors who use - these protocols. There's a<A href="http://www.rsa.com/rsa/SWAN/swan_test.htm"> - compatability chart</A> that shows which vendors have tested their - boxes against which other vendors to guarantee interoperatility.</P> -<P>Eventually it will also move into the operating systems and - networking protocol stacks of major vendors. This will probably take - longer, because those vendors will have to figure out what they want to - do about the export controls.</P> -<H4>Current status</H4> -<P>My initial goal of securing 5% of the net by Christmas '96 was not - met. It was an ambitious goal, and inspired me and others to work hard, - but was ultimately too ambitious. The protocols were in an early stage - of development, and needed a lot more protocol design before they could - be implemented. As of April 1999, we have released version 1.0 of the - software (<A href="ftp://ftp.xs4all.nl/freeswan/freeswan-1.0.tar.gz"> -freeswan-1.0.tar.gz</A>), which is suitable for setting up Virtual - Private Networks using shared secrets for authentication. It does not - yet do opportunistic encryption, or use DNSSEC for authentication; - those features are coming in a future release.</P> -<DL> -<DT>Protocols</DT> -<DD>The low-level encrypted packet formats are defined. The system for - publishing keys and providing secure domain name service is defined. - The IP Security working group has settled on an NSA-sponsored protocol - for key agreement (called ISAKMP/Oakley), but it is still being worked - on, as the protocol and its documentation is too complex and - incomplete. There are prototype implementations of ISAKMP. The protocol - is not yet defined to enable opportunistic encryption or the use of - DNSSEC keys.</DD> -<DT>Linux Implementation</DT> -<DD>The Linux implementation has reached its first major release and is - ready for production use in manually-configured networks, using Linux - kernel version 2.0.36.</DD> -<DT>Domain Name System Security</DT> -<DD>There is now a release of BIND 8.2 that includes most DNS Security - features. -<P>The first prototype implementation of Domain Name System Security was - funded by<A href="glossary.html#DARPA"> DARPA</A> as part of their<A href="http://www.darpa.mil/ito/research/is/index.html"> - Information Survivability program</A>.<A href="http://www.tis.com"> - Trusted Information Systems</A> wrote a modified version of<A href="http://www.isc.org/bind.html"> - BIND</A>, the widely-used Berkeley implementation of the Domain Name - System.</P> -<P>TIS, ISC, and I merged the prototype into the standard version of - BIND. The first production version that supports KEY and SIG records is<B> - bind-4.9.5</B>. This or any later version of BIND will do for - publishing keys. It is available from the<A href="http://www.isc.org/bind.html"> - Internet Software Consortium</A>. This version of BIND is not - export-controlled since it does not contain any cryptography. Later - releases starting with BIND 8.2 include cryptography for authenticating - DNS records, which is also exportable. Better documentation is needed.</P> -</DD> -</DL> -<H4>Why?</H4> -<P>Because I can. I have made enough money from several successful - startup companies, that for a while I don't have to work to support - myself. I spend my energies and money creating the kind of world that - I'd like to live in and that I'd like my (future) kids to live in. - Keeping and improving on the civil rights we have in the United States, - as we move more of our lives into cyberspace, is a particular goal of - mine.</P> -<H4>What You Can Do</H4> -<DL> -<DT>Install the latest BIND at your site.</DT> -<DD>You won't be able to publish any keys for your domain, until you - have upgraded your copy of BIND. The thing you really need from it is - the new version of<I> named</I>, the Name Daemon, which knows about the - new KEY and SIG record types. So, download it from the<A href="http://www.isc.org/bind.html"> - Internet Software Consortium</A> and install it on your name server - machine (or get your system administrator, or Internet Service - Provider, to install it). Both your primary DNS site and all of your - secondary DNS sites will need the new release before you will be able - to publish your keys. You can tell which sites this is by running the - Unix command "dig MYDOMAIN ns" and seeing which sites are mentioned in - your NS (name server) records.</DD> -<DT>Set up a Linux system and run a 2.0.x kernel on it</DT> -<DD>Get a machine running Linux (say the 5.2 release from<A href="http://www.redhat.com"> - Red Hat</A>). Give the machine two Ethernet cards.</DD> -<DT>Install the Linux IPSEC (Freeswan) software</DT> -<DD>If you're an experienced sysadmin or Linux hacker, install the - freeswan-1.0 release, or any later release or snapshot. These releases - do NOT provide automated "opportunistic" operation; they must be - manually configured for each site you wish to encrypt with.</DD> -<DT>Get on the linux-ipsec mailing list</DT> -<DD>The discussion forum for people working on the project, and testing - the code and documentation, is: linux-ipsec@clinet.fi. To join this - mailing list, send email to<A href="mailto:linux-ipsec-REQUEST@clinet.fi"> - linux-ipsec-REQUEST@clinet.fi</A> containing a line of text that says - "subscribe linux-ipsec". (You can later get off the mailing list the - same way -- just send "unsubscribe linux-ipsec").</DD> -<P></P> -<DT>Check back at this web page every once in a while</DT> -<DD>I update this page periodically, and there may be new information in - it that you haven't seen. My intent is to send email to the mailing - list when I update the page in any significant way, so subscribing to - the list is an alternative.</DD> -</DL> -<P>Would you like to help? I can use people who are willing to write - documentation, install early releases for testing, write cryptographic - code outside the United States, sell pre-packaged software or systems - including this technology, and teach classes for network administrators - who want to install this technology. To offer to help, send me email at - gnu@toad.com. Tell me what country you live in and what your - citizenship is (it matters due to the export control laws; personally I - don't care). Include a copy of your resume and the URL of your home - page. Describe what you'd like to do for the project, and what you're - uniquely qualified for. Mention what other volunteer projects you've - been involved in (and how they worked out). Helping out will require - that you be able to commit to doing particular things, meet your - commitments, and be responsive by email. Volunteer projects just don't - work without those things.</P> -<H4>Related projects</H4> -<DL> -<DT>IPSEC for NetBSD</DT> -<DD>This prototype implementation of the IP Security protocols is for - another free operating system.<A href="ftp://ftp.funet.fi/pub/unix/security/net/ip/BSDipsec.tar.gz"> - Download BSDipsec.tar.gz</A>.</DD> -<DT>IPSEC for<A href="http://www.openbsd.org"> OpenBSD</A></DT> -<DD>This prototype implementation of the IP Security protocols is for - yet another free operating system. It is directly integrated into the - OS release, since the OS is maintained in Canada, which has freedom of - speech in software.</DD> -</DL> -<H3><A name="policestate">Stopping wholesale monitoring</A></H3> -<P>From a message project leader John Gilmore posted to the mailing - list:</P> -<PRE>John Denker wrote: - -> Indeed there are several ways in which the documentation overstates the -> scope of what this project does -- starting with the name -> FreeS/WAN. There's a big difference between having an encrypted IP tunnel -> versus having a Secure Wide-Area Network. This software does a fine job of -> the former, which is necessary but not sufficient for the latter. - -The goal of the project is to make it very hard to tap your wide area -communications. The current system provides very good protection -against passive attacks (wiretapping and those big antenna farms). -Active attacks, which involve the intruder sending packets to your -system (like packets that break into sendmail and give them a root -shell :-) are much harder to guard against. Active attacks that -involve sending people (breaking into your house and replacing parts -of your computer with ones that transmit what you're doing) are also -much harder to guard against. Though we are putting effort into -protecting against active attacks, it's a much bigger job than merely -providing strong encryption. It involves general computer security, -and general physical security, which are two very expensive problems -for even a site to solve, let alone to build into a whole society. - -The societal benefit of building an infrastructure that protects -well against passive attacks is that it makes it much harder to do -undetected bulk monitoring of the population. It's a defense against -police-states, not against policemen. - -Policemen can put in the effort required to actively attack sites that -they have strong suspicions about. But police states won't be able to -build systems that automatically monitor everyone's communications. -Either they will be able to monitor only a small subset of the -populace (by targeting those who screwed up their passive security), -or their monitoring activities will be detectable by those monitored -(active attacks leave packet traces or footprints), which can then be -addressed through the press and through political means if they become -too widespread. - -FreeS/WAN does not protect very well against traffic analysis, which -is a kind of widespread police-state style monitoring that still -reveals significant information (who's talking to who) without -revealing the contents of what was said. Defenses against traffic -analysis are an open research problem. Zero Knowledge Systems is -actively deploying a system designed to thwart it, designed by Ian -Goldberg. The jury is out on whether it actually works; a lot more -experience with it will be needed.</PRE> -<P>Notes on things mentioned in that message:</P> -<UL> -<LI>Denker is a co-author of a<A href="intro.html#applied"> paper</A> on - a large FreeS/WAN application.</LI> -<LI>Information on Zero Knowledge is on their<A href="http://www.zks.net/"> - web site</A>. Their Freedom product, designed to provide untracable - pseudonyms for use on the net, is no longer marketed.</LI> -<LI>Another section of our documentation discusses ways to<A href="ipsec.html#traffic.resist"> - resist traffic analysis</A>.</LI> -</UL> -<H2><A name="weak">Government promotion of weak crypto</A></H2> -<P>Various groups, especially governments and especially the US - government, have a long history of advocating various forms of bogus - security.</P> -<P>We regard bogus security as extremely dangerous. If users are - deceived into relying on bogus security, then they may be exposed to - large risks. They would be better off having no security and knowing - it. At least then they would be careful about what they said.</P> -<P><STRONG>Avoiding bogus security is a key design criterion for - everything we do in FreeS/WAN</STRONG>. The most conspicuous example is - our refusal to support<A href="#desnotsecure"> single DES</A>. Other - IPsec "features" which we do not implement are discussed in our<A href="compat.html#dropped"> - compatibility</A> document.</P> -<H3><A name="escrow">Escrowed encryption</A></H3> -<P>Various governments have made persistent attempts to encourage or - mandate "escrowed encrytion", also called "key recovery", or GAK for - "government access to keys". The idea is that cryptographic keys be - held by some third party and turned over to law enforcement or security - agencies under some conditions.</P> -<PRE> Mary had a little key - she kept it in escrow, - and every thing that Mary said, - the feds were sure to know.</PRE> -<P>A<A href="web.html#quotes"> crypto quotes</A> page attributes this to<A -href="http://www.scramdisk.clara.net/"> Sam Simpson</A>.</P> -<P>There is an excellent paper available on<A href="http://www.cdt.org/crypto/risks98/"> - Risks of Escrowed Encryption</A>, from a group of cryptographic - luminaries which included our project leader.</P> -<P>Like any unnecessary complication, GAK tends to weaken security of - any design it infects. For example:</P> -<UL> -<LI>Matt Blaze found a fatal flaw in the US government's Clipper chip - shortly after design information became public. See his paper "Protocol - Failure in the Escrowed Encryption Standard" on his<A href="http://www.crypto.com/papers/"> - papers</A> page.</LI> -<LI>a rather<A href="http://www.pgp.com/other/advisories/adk.asp"> nasty - bug</A> was found in the "additional decryption keys" "feature" of some - releases of<A href="glossary.html#PGP"> PGP</A></LI> -</UL> -<P>FreeS/WAN does not support escrowed encryption, and never will.</P> -<H3><A name="shortkeys">Limited key lengths</A></H3> -<P>Various governments, and some vendors, have also made persistent - attempts to convince people that:</P> -<UL> -<LI>weak systems are sufficient for some data</LI> -<LI>strong cryptography should be reserved for cases where the extra - overheads are justified</LI> -</UL> -<P><STRONG>This is utter nonsense</STRONG>.</P> -<P>Weak systems touted include:</P> -<UL> -<LI>the ludicrously weak (deliberately crippled) 40-bit ciphers that - until recently were all various<A href="#exlaw"> export laws</A> - allowed</LI> -<LI>56-bit single DES, discussed<A href="#desnotsecure"> below</A></LI> -<LI>64-bit symmetric ciphers and 512-bit RSA, the maximums for - unrestricted export under various current laws</LI> -</UL> -<P>The notion that choice of ciphers or keysize should be determined by - a trade-off between security requirements and overheads is pure - bafflegab.</P> -<UL> -<LI>For most<A href="glossary.html#symmetric"> symmetric ciphers</A>, it - is simply a lie. Any block cipher has some natural maximum keysize - inherent in the design -- 128 bits for<A href="glossary.html#IDEA"> - IDEA</A> or<A href="glossary.html#CAST128"> CAST-128</A>, 256 for - Serpent or Twofish, 448 for<A href="glossary.html#Blowfish"> Blowfish</A> - and 2048 for<A href="glossary.html#RC4"> RC4</A>. Using a key size - smaller than that limit gives<EM> exactly zero</EM> savings in - overhead. The crippled 40-bit or 64-bit version of the cipher provides<EM> - no advantage whatsoever</EM>.</LI> -<LI><A href="glossary.html#AES">AES</A> uses 10 rounds with 128-bit - keys, 12 rounds for 192-bit and 14 rounds for 256-bit, so there - actually is a small difference in overhead, but not enough to matter in - most applications.</LI> -<LI>For<A href="glossary.html#3DES"> triple DES</A> there is a grain of - truth in the argument. 3DES is indeed three times slower than single - DES. However, the solution is not to use the insecure single DES, but - to pick a faster secure cipher.<A href="glossary.html#CAST128"> - CAST-128</A>,<A href="glossary.html#Blowfish"> Blowfish</A> and the<A href="glossary.html#AES"> - AES candidate</A> ciphers are are all considerably faster in software - than DES (let alone 3DES!), and apparently secure.</LI> -<LI>For<A href="glossary.html#public"> public key</A> techniques, there - are extra overheads for larger keys, but they generally do not affect - overall performance significantly. Practical public key applications - are usually<A href="glossary.html#hybrid"> hybrid</A> systems in which - the bulk of the work is done by a symmetric cipher. The effect of - increasing the cost of the public key operations is typically - negligible because the public key operations use only a tiny fraction - of total resources. -<P>For example, suppose public key operations use use 1% of the time in - a hybrid system and you triple the cost of public key operations. The - cost of symmetric cipher operations is unchanged at 99% of the original - total cost, so the overall effect is a jump from 99 + 1 = 100 to 99 + 3 - = 102, a 2% rise in system cost.</P> -</LI> -</UL> -<P>In short,<STRONG> there has never been any technical reason to use - inadequate ciphers</STRONG>. The only reason there has ever been for - anyone to use such ciphers is that government agencies want weak - ciphers used so that they can crack them. The alleged savings are - simply propaganda.</P> -<PRE> Mary had a little key (It's all she could export), - and all the email that she sent was opened at the Fort.</PRE> -<P>A<A href="web.html#quotes"> crypto quotes</A> page attributes this to<A -href="http://theory.lcs.mit.edu:80/~rivest/"> Ron Rivest</A>. NSA - headquarters is at Fort Meade, Maryland.</P> -<P>Our policy in FreeS/WAN is to use only cryptographic components with - adequate keylength and no known weaknesses.</P> -<UL> -<LI>We do not implement single DES because it is clearly<A href="#desnotsecure"> - insecure</A>, so implemeting it would violate our policy of avoiding - bogus security. Our default cipher is<A href="glossary.html#3DES"> 3DES</A> -</LI> -<LI>Similarly, we do not implement the 768-bit Group 1 for<A href="glossary.html#DH"> - Diffie-Hellman</A> key negotiation. We provide only the 1024-bit Group - 2 and 1536-bit Group 5.</LI> -</UL> -<P>Detailed discussion of which IPsec features we implement or omit is - in out<A href="compat.html"> compatibility document</A>.</P> -<P>These decisions imply that we cannot fully conform to the IPsec RFCs, - since those have DES as the only required cipher and Group 1 as the - only required DH group. (In our view, the standards were subverted into - offerring bogus security.) Fortunately, we can still interoperate with - most other IPsec implementations since nearly all implementers provide - at least 3DES and Group 2 as well.</P> -<P>We hope that eventually the RFCs will catch up with our (and others') - current practice and reject dubious components. Some of our team and a - number of others are working on this in<A href="glossary.html#IETF"> - IETF</A> working groups.</P> -<H4>Some real trade-offs</H4> -<P>Of course, making systems secure does involve costs, and trade-offs - can be made between cost and security. However, the real trade-offs - have nothing to do with using weaker ciphers.</P> -<P>There can be substantial hardware and software costs. There are often - substantial training costs, both to train administrators and to - increase user awareness of security issues and procedures. There are - almost always substantial staff or contracting costs.</P> -<P>Security takes staff time for planning, implementation, testing and - auditing. Some of the issues are subtle; you need good (hence often - expensive) people for this. You also need people to monitor your - systems and respond to problems. The best safe ever built is insecure - if an attacker can work on it for days without anyone noticing. Any - computer is insecure if the administrator is "too busy" to check the - logs.</P> -<P>Moreover, someone in your organisation (or on contract to it) needs - to spend considerable time keeping up with new developments. EvilDoers<EM> - will</EM> know about new attacks shortly after they are found. You need - to know about them before your systems are attacked. If your vendor - provides a patch, you need to apply it. If the vendor does nothing, you - need to complain or start looking for another vendor.</P> -<P>For a fairly awful example, see this<A href="http://www.sans.org/newlook/alerts/NTE-bank.htm"> - report</A>. In that case over a million credit card numbers were taken - from e-commerce sites, using security flaws in Windows NT servers. - Microsoft had long since released patches for most or all of the flaws, - but the site administrators had not applied them.</P> -<P>At an absolute minimum, you must do something about such issues<EM> - before</EM> an exploitation tool is posted to the net for downloading - by dozens of "script kiddies". Such a tool might appear at any time - from the announcement of the security hole to several months later. - Once it appears, anyone with a browser and an attitude can break any - system whose administrators have done nothing about the flaw.</P> -<P>Compared to those costs, cipher overheads are an insignificant factor - in the cost of security.</P> -<P>The only thing using a weak cipher can do for you is to cause all - your other investment to be wasted.</P> -<H2><A name="exlaw">Cryptography Export Laws</A></H2> -<P>Many nations restrict the export of cryptography and some restrict - its use by their citizens or others within their borders.</P> -<H3><A name="USlaw">US Law</A></H3> -<P>US laws, as currently interpreted by the US government, forbid export - of most cryptographic software from the US in machine-readable form - without government permission. In general, the restrictions apply even - if the software is widely-disseminated or public-domain and even if it - came from outside the US originally. Cryptography is legally a munition - and export is tightly controlled under the<A href="glossary.html#EAR"> - EAR</A> Export Administration Regulations.</P> -<P>If you are a US citizen, your brain is considered US territory no - matter where it is physically located at the moment. The US believes - that its laws apply to its citizens everywhere, not just within the US. - Providing technical assistance or advice to foreign "munitions" - projects is illegal. The US government has very little sense of humor - about this issue and does not consider good intentions to be sufficient - excuse. Beware.</P> -<P>The<A href="http://www.bxa.doc.gov/Encryption/"> official website</A> - for these regulations is run by the Commerce Department's Bureau of - Export Administration (BXA).</P> -<P>The<A href="http://www.eff.org/bernstein/"> Bernstein case</A> - challenges the export restrictions on Constitutional grounds. Code is - speech so restrictions on export of code violate the First Amendment's - free speech provisions. This argument has succeeded in two levels of - court so far. It is quite likely to go on to the Supreme Court.</P> -<P>The regulations were changed substantially in January 2000, - apparently as a government attempt to get off the hook in the Bernstein - case. It is now legal to export public domain source code for - encryption, provided you notify the<A href="glossary.html#BXA"> BXA</A> -.</P> -<P>There are, however, still restrictions in force. Moreover, the - regulations can still be changed again whenever the government chooses - to do so. Short of a Supreme Court ruling (in the Berstein case or - another) that overturns the regulations completely, the problem of - export regulation is not likely to go away in the forseeable future.</P> -<H4><A name="UScontrib">US contributions to FreeS/WAN</A></H4> -<P>The FreeS/WAN project<STRONG> cannot accept software contributions,<EM> - not even small bug fixes</EM>, from US citizens or residents</STRONG>. - We want it to be absolutely clear that our distribution is not subject - to US export law. Any contribution from an American might open that - question to a debate we'd prefer to avoid. It might also put the - contributor at serious legal risk.</P> -<P>Of course Americans can still make valuable contributions (many - already have) by reporting bugs, or otherwise contributing to - discussions, on the project<A href="mail.html"> mailing list</A>. Since - the list is public, this is clearly constitutionally protected free - speech.</P> -<P>Note, however, that the export laws restrict Americans from providing - technical assistance to foreign "munitions" projects. The government - might claim that private discussions or correspondence with FreeS/WAN - developers were covered by this. It is not clear what the courts would - do with such a claim, so we strongly encourage Americans to use the - list rather than risk the complications.</P> -<H3><A name="wrong">What's wrong with restrictions on cryptography</A></H3> -<P>Some quotes from prominent cryptography experts:</P> -<BLOCKQUOTE> The real aim of current policy is to ensure the continued - effectiveness of US information warfare assets against individuals, - businesses and governments in Europe and elsewhere. -<BR><A href="http://www.cl.cam.ac.uk/users/rja14"> Ross Anderson, - Cambridge University</A></BLOCKQUOTE><BLOCKQUOTE> If the government - were honest about its motives, then the debate about crypto export - policy would have ended years ago. -<BR><A href="http://www.counterpane.com"> Bruce Schneier, Counterpane - Systems</A></BLOCKQUOTE><BLOCKQUOTE> The NSA regularly lies to people - who ask it for advice on export control. They have no reason not to; - accomplishing their goal by any legal means is fine by them. Lying by - government employees is legal. -<BR> John Gilmore.</BLOCKQUOTE> -<P>The Internet Architecture Board (IAB) and the Internet Engineering - Steering Group (IESG) made a<A href="iab-iesg.stmt"> strong statement</A> - in favour of worldwide access to strong cryptography. Essentially the - same statement is in the appropriately numbered<A href="ftp://ftp.isi.edu/in-notes/rfc1984.txt"> - RFC 1984</A>. Two critical paragraphs are:</P> -<BLOCKQUOTE> ... various governments have actual or proposed policies on - access to cryptographic technology ... -<P>(a) ... export controls ... -<BR> (b) ... short cryptographic keys ... -<BR> (c) ... keys should be in the hands of the government or ... -<BR> (d) prohibit the use of cryptology ...</P> -<P>We believe that such policies are against the interests of consumers - and the business community, are largely irrelevant to issues of - military security, and provide only a marginal or illusory benefit to - law enforcement agencies, ...</P> -<P>The IAB and IESG would like to encourage policies that allow ready - access to uniform strong cryptographic technology for all Internet - users in all countries.</P> -</BLOCKQUOTE> -<P>Our goal in the FreeS/WAN project is to build just such "strong - cryptographic technology" and to distribute it "for all Internet users - in all countries".</P> -<P>More recently, the same two bodies (IESG and IAB) have issued<A href="ftp://ftp.isi.edu/in-notes/rfc2804.txt"> - RFC 2804</A> on why the IETF should not build wiretapping capabilities - into protocols for the convenience of security or law enforcement - agenicies. The abstract from that document is:</P> -<BLOCKQUOTE> The Internet Engineering Task Force (IETF) has been asked - to take a position on the inclusion into IETF standards-track documents - of functionality designed to facilitate wiretapping. -<P>This memo explains what the IETF thinks the question means, why its - answer is "no", and what that answer means.</P> -</BLOCKQUOTE> A quote from the debate leading up to that RFC:<BLOCKQUOTE> - We should not be building surveillance technology into standards. Law - enforcement was not supposed to be easy. Where it is easy, it's called - a police state. -<BR> Jeff Schiller of MIT, in a discussion of FBI demands for wiretap - capability on the net, as quoted by<A href="http://www.wired.com/news/politics/0,1283,31895,00.html"> - Wired</A>.</BLOCKQUOTE> -<P>The<A href="http://www.ietf.org/mailman/listinfo/raven"> Raven</A> - mailing list was set up for this IETF discussion.</P> -<P>Our goal is to go beyond that RFC and prevent Internet wiretapping - entirely.</P> -<H3><A name="Wassenaar">The Wassenaar Arrangement</A></H3> -<P>Restrictions on the export of cryptography are not just US policy, - though some consider the US at least partly to blame for the policies - of other nations in this area.</P> -<P>A number of countries:</P> -<P>Argentina, Australia, Austria, Belgium, Bulgaria, Canada, Czech - Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, - Italy, Japan, Luxembourg, Netherlands, New Zealand, Norway, Poland, - Portugal, Republic of Korea, Romania, Russian Federation, Slovak - Republic, Spain, Sweden, Switzerland, Turkey, Ukraine, United Kingdom - and United States</P> -<P>have signed the Wassenaar Arrangement which restricts export of - munitions and other tools of war. Cryptographic sofware is covered - there.</P> -<P>Wassenaar details are available from the<A href="http://www.wassenaar.org/"> - Wassenaar Secretariat</A>, and elsewhere in a more readable<A href="http://www.fitug.de/news/wa/index.html"> - HTML version</A>.</P> -<P>For a critique see the<A href="http://www.gilc.org/crypto/wassenaar"> - GILC site</A>:</P> -<BLOCKQUOTE> The Global Internet Liberty Campaign (GILC) has begun a - campaign calling for the removal of cryptography controls from the - Wassenaar Arrangement. -<P>The aim of the Wassenaar Arrangement is to prevent the build up of - military capabilities that threaten regional and international security - and stability . . .</P> -<P>There is no sound basis within the Wassenaar Arrangement for the - continuation of any export controls on cryptographic products.</P> -</BLOCKQUOTE> -<P>We agree entirely.</P> -<P>An interesting analysis of Wassenaar can be found on the<A href="http://www.cyber-rights.org/crypto/wassenaar.htm"> - cyber-rights.org</A> site.</P> -<H3><A name="status">Export status of Linux FreeS/WAN</A></H3> -<P>We believe our software is entirely exempt from these controls since - the Wassenaar<A href="http://www.wassenaar.org/list/GTN%20and%20GSN%20-%2099.pdf"> - General Software Note</A> says:</P> -<BLOCKQUOTE> The Lists do not control "software" which is either: -<OL> -<LI>Generally available to the public by . . . retail . . . or</LI> -<LI>"In the public domain".</LI> -</OL> -</BLOCKQUOTE> -<P>There is a note restricting some of this, but it is a sub-heading - under point 1, so it appears not to apply to public domain software.</P> -<P>Their glossary defines "In the public domain" as:</P> -<BLOCKQUOTE> . . . "technology" or "software" which has been made - available without restrictions upon its further dissemination. -<P>N.B. Copyright restrictions do not remove "technology" or "software" - from being "in the public domain".</P> -</BLOCKQUOTE> -<P>We therefore believe that software freely distributed under the<A href="glossary.html#GPL"> - GNU Public License</A>, such as Linux FreeS/WAN, is exempt from - Wassenaar restrictions.</P> -<P>Most of the development work is being done in Canada. Our - understanding is that the Canadian government accepts this - interpretation.</P> -<UL> -<LI>A web statement of<A href="http://www.dfait-maeci.gc.ca/~eicb/notices/ser113-e.htm"> - Canadian policy</A> is available from the Department of Foreign Affairs - and International Trade.</LI> -<LI>Another document from that department states that<A href="http://www.dfait-maeci.gc.ca/~eicb/export/gr1_e.htm"> - public domain software</A> is exempt from the export controls.</LI> -<LI>A researcher's<A href="http://insight.mcmaster.ca/org/efc/pages/doc/crypto-export.html"> - analysis</A> of Canadian policy is also available.</LI> -</UL> -<P>Recent copies of the freely modifiable and distributable source code - exist in many countries. Citizens all over the world participate in its - use and evolution, and guard its ongoing distribution. Even if Canadian - policy were to change, the software would continue to evolve in - countries which do not restrict exports, and would continue to be - imported from there into unfree countries. "The Net culture treats - censorship as damage, and routes around it."</P> -<H3><A name="help">Help spread IPsec around</A></H3> -<P>You can help. If you don't know of a Linux FreeS/WAN archive in your - own country, please download it now to your personal machine, and - consider making it publicly accessible if that doesn't violate your own - laws. If you have the resources, consider going one step further and - setting up a mirror site for the whole<A href="intro.html#munitions"> - munitions</A> Linux crypto software archive.</P> -<P>If you make Linux CD-ROMs, please consider including this code, in a - way that violates no laws (in a free country, or in a domestic-only CD - product).</P> -<P>Please send a note about any new archive mirror sites or CD - distributions to linux-ipsec@clinet.fi so we can update the - documentation.</P> -<P>Lists of current<A href="intro.html#sites"> mirror sites</A> and of<A href="intro.html#distwith"> - distributions</A> which include FreeS/WAN are in our introduction - section.</P> -<H2><A name="desnotsecure">DES is Not Secure</A></H2> -<P>DES, the<STRONG> D</STRONG>ata<STRONG> E</STRONG>ncryption<STRONG> S</STRONG> -tandard, can no longer be considered secure. While no major flaws in its - innards are known, it is fundamentally inadequate because its<STRONG> - 56-bit key is too short</STRONG>. It is vulnerable to<A href="glossary.html#brute"> - brute-force search</A> of the whole key space, either by large - collections of general-purpose machines or even more quickly by - specialized hardware. Of course this also applies to<STRONG> any other - cipher with only a 56-bit key</STRONG>. The only reason anyone could - have for using a 56 or 64-bit key is to comply with various<A href="exportlaw.html"> - export laws</A> intended to ensure the use of breakable ciphers.</P> -<P>Non-government cryptologists have been saying DES's 56-bit key was - too short for some time -- some of them were saying it in the 70's when - DES became a standard -- but the US government has consistently - ridiculed such suggestions.</P> -<P>A group of well-known cryptographers looked at key lengths in a<A href="http://www.counterpane.com/keylength.html"> - 1996 paper</A>. They suggested a<EM> minimum</EM> of 75 bits to - consider an existing cipher secure and a<EM> minimum of 90 bits for new - ciphers</EM>. More recent papers, covering both<A href="glossary.html#symmetric"> - symmetric</A> and<A href="glossary.html#public"> public key</A> systems - are at<A href="http://www.cryptosavvy.com/"> cryptosavvy.com</A> and<A href="http://www.rsasecurity.com/rsalabs/bulletins/bulletin13.html"> - rsa.com</A>. For all algorithms, the minimum keylengths recommended in - such papers are significantly longer than the maximums allowed by - various export laws.</P> -<P>In a<A href="http://www.privacy.nb.ca/cryptography/archives/cryptography/html/1998-09/0095.html"> - 1998 ruling</A>, a German court described DES as "out-of-date and not - safe enough" and held a bank liable for using it.</P> -<H3><A name="deshware">Dedicated hardware breaks DES in a few days</A></H3> -<P>The question of DES security has now been settled once and for all. - In early 1998, the<A href="http://www.eff.org/"> Electronic Frontier - Foundation</A> built a<A href="http://www.eff.org/descracker.html"> - DES-cracking machine</A>. It can find a DES key in an average of a few - days' search. The details of all this, including complete code listings - and complete plans for the machine, have been published in<A href="biblio.html#EFF"> -<CITE> Cracking DES</CITE></A>, by the Electronic Frontier Foundation.</P> -<P>That machine cost just over $200,000 to design and build. "Moore's - Law" is that machines get faster (or cheaper, for the same speed) by - roughly a factor of two every 18 months. At that rate, their $200,000 - in 1998 becomes $50,000 in 2001.</P> -<P>However, Moore's Law is not exact and the $50,000 estimate does not - allow for the fact that a copy based on the published EFF design would - cost far less than the original. We cannot say exactly what such a - cracker would cost today, but it would likely be somewhere between - $10,000 and $100,000.</P> -<P>A large corporation could build one of these out of petty cash. The - cost is low enough for a senior manager to hide it in a departmental - budget and avoid having to announce or justify the project. Any - government agency, from a major municipal police force up, could afford - one. Or any other group with a respectable budget -- criminal - organisations, political groups, labour unions, religious groups, ... - Or any millionaire with an obsession or a grudge, or just strange taste - in toys.</P> -<P>One might wonder if a private security or detective agency would have - one for rent. They wouldn't need many clients to pay off that - investment.</P> -<H3><A name="spooks">Spooks may break DES faster yet</A></H3> -<P>As for the security and intelligence agencies of various nations, - they may have had DES crackers for years, and theirs may be much - faster. It is difficult to make most computer applications work well on - parallel machines, or to design specialised hardware to accelerate - them. Cipher-cracking is one of the very few exceptions. It is entirely - straightforward to speed up cracking by just adding hardware. Within - very broad limits, you can make it as fast as you like if you have the - budget. The EFF's $200,000 machine breaks DES in a few days. An<A href="http://www.planepage.com/"> - aviation website</A> gives the cost of a B1 bomber as $200,000,000. - Spending that much, an intelligence agency could break DES in an - average time of<EM> six and a half minutes</EM>.</P> -<P>That estimate assumes they use the EFF's 1998 technology and just - spend more money. They may have an attack that is superior to brute - force, they quite likely have better chip technology (Moore's law, a - bigger budget, and whatever secret advances they may have made) and of - course they may have spent the price of an aircraft carrier, not just - one aircraft.</P> -<P>In short, we have<EM> no idea</EM> how quickly these organisations - can break DES. Unless they're spectacularly incompetent or horribly - underfunded, they can certainly break it, but we cannot guess how - quickly. Pick any time unit between days and milliseconds; none is - entirely unbelievable. More to the point, none of them is of any - comfort if you don't want such organisations reading your - communications.</P> -<P>Note that this may be a concern even if nothing you do is a threat to - anyone's national security. An intelligence agency might well consider - it to be in their national interest for certain companies to do well. - If you're competing against such companies in a world market and that - agency can read your secrets, you have a serious problem.</P> -<P>One might wonder about technology the former Soviet Union and its - allies developed for cracking DES during the Cold War. They must have - tried; the cipher was an American standard and widely used. Certainly - those countries have some fine mathematicians, and those agencies had - budget. How well did they succeed? Is their technology now for sale or - rent?</P> -<H3><A name="desnet">Networks break DES in a few weeks</A></H3> -<P>Before the definitive EFF effort, DES had been cracked several times - by people using many machines. See this<A href="http://www.distributed.net/pressroom/DESII-1-PR.html"> - press release</A> for example.</P> -<P>A major corporation, university, or government department could break - DES by using spare cycles on their existing collection of computers, by - dedicating a group of otherwise surplus machines to the problem, or by - combining the two approaches. It might take them weeks or months, - rather than the days required for the EFF machine, but they could do - it.</P> -<P>What about someone working alone, without the resources of a large - organisation? For them, cracking DES will not be easy, but it may be - possible. A few thousand dollars buys a lot of surplus workstations. A - pile of such machines will certainly heat your garage nicely and might - break DES in a few months or years. Or enroll at a university and use - their machines. Or use an employer's machines. Or crack security - somewhere and steal the resources to crack a DES key. Or write a virus - that steals small amounts of resources on many machines. Or . . .</P> -<P>None of these approaches are easy or break DES really quickly, but an - attacker only needs to find one that is feasible and breaks DES quickly - enough to be dangerous. How much would you care to bet that this will - be impossible if the attacker is clever and determined? How valuable is - your data? Are you authorised to risk it on a dubious bet?</P> -<H3><A name="no_des">We disable DES</A></H3> -<P>In short, it is now absolutely clear that<STRONG> DES is not secure</STRONG> - against</P> -<UL> -<LI>any<STRONG> well-funded opponent</STRONG></LI> -<LI>any opponent (even a penniless one) with access (even stolen access) - to<STRONG> enough general purpose computers</STRONG></LI> -</UL> -<P>That is why<STRONG> Linux FreeS/WAN disables all transforms which use - plain DES</STRONG> for encryption.</P> -<P>DES is in the source code, because we need DES to implement our - default encryption transform,<A href="glossary.html#3DES"> Triple DES</A> -.<STRONG> We urge you not to use single DES</STRONG>. We do not provide - any easy way to enable it in FreeS/WAN, and our policy is to provide no - assistance to anyone wanting to do so.</P> -<H3><A name="40joke">40-bits is laughably weak</A></H3> -<P>The same is true, in spades, of ciphers -- DES or others -- crippled - by 40-bit keys, as many ciphers were required to be until recently - under various<A href="#exlaw"> export laws</A>. A brute force search of - such a cipher's keyspace is 2<SUP>16</SUP> times faster than a similar - search against DES. The EFF's machine can do a brute-force search of a - 40-bit key space in<EM> seconds</EM>. One contest to crack a 40-bit - cipher was won by a student<A href="http://catless.ncl.ac.uk/Risks/18.80.html#subj1"> - using a few hundred idle machines at his university</A>. It took only - three and half hours.</P> -<P>We do not, and will not, implement any 40-bit cipher.</P> -<H3><A name="altdes">Triple DES is almost certainly secure</A></H3> -<P><A href="glossary.html#3DES">Triple DES</A>, usually abbreviated - 3DES, applies DES three times, with three different keys. DES seems to - be basically an excellent cipher design; it has withstood several - decades of intensive analysis without any disastrous flaws being found. - It's only major flaw is that the small keyspace allows brute force - attacks to succeeed. Triple DES enlarges the key space to 168 bits, - making brute-force search a ridiculous impossibility.</P> -<P>3DES is currently the only block cipher implemented in FreeS/WAN. - 3DES is, unfortunately, about 1/3 the speed of DES, but modern CPUs - still do it at quite respectable speeds. Some<A href="glossary.html#benchmarks"> - speed measurements</A> for our code are available.</P> -<H3><A name="aes.ipsec">AES in IPsec</A></H3> -<P>The<A href="glossary.html#AES"> AES</A> project has chosen a - replacement for DES, a new standard cipher for use in non-classified US - government work and in regulated industries such as banking. This - cipher will almost certainly become widely used for many applications, - including IPsec.</P> -<P>The winner, announced in October 2000 after several years of analysis - and discussion, was the<A href="http://www.esat.kuleuven.ac.be/~rijmen/rijndael/"> - Rijndael</A> cipher from two Belgian designers.</P> -<P>It is almost certain that FreeS/WAN will add AES support.<A href="web.html#patch"> - AES patches</A> are already available.</P> -<H2><A name="press">Press coverage of Linux FreeS/WAN:</A></H2> -<H3><A NAME="26_6_1">FreeS/WAN 1.0 press</A></H3> -<UL> -<LI><A href="http://www.wired.com/news/news/technology/story/19136.html"> -Wired</A> "Linux-Based Crypto Stops Snoops", James Glave April 15 1999</LI> -<LI><A href="http://slashdot.org/articles/99/04/15/1851212.shtml"> -Slashdot</A></LI> -<LI><A href="http://dgl.com/itinfo/1999/it990415.html">DGL</A>, Damar - Group Limited; looking at FreeS/WAN from a perspective of business - computing</LI> -<LI><A href="http://linuxtoday.com/stories/5010.html">Linux Today</A></LI> -<LI><A href="http://www.tbtf.com/archive/1999-04-21.html#Tcep">TBTF</A>, - Tasty Bits from the Technology Front</LI> -<LI><A href="http://www.salonmagazine.com/tech/log/1999/04/16/encryption/index.html"> -Salon Magazine</A> "Free Encryption Takes a Big Step"</LI> -</UL> -<H3><A name="release">Press release for version 1.0</A></H3> -<PRE> Strong Internet Privacy Software Free for Linux Users Worldwide - -Toronto, ON, April 14, 1999 - - -The Linux FreeS/WAN project today released free software to protect -the privacy of Internet communications using strong encryption codes. -FreeS/WAN automatically encrypts data as it crosses the Internet, to -prevent unauthorized people from receiving or modifying it. One -ordinary PC per site runs this free software under Linux to become a -secure gateway in a Virtual Private Network, without having to modify -users' operating systems or application software. The project built -and released the software outside the United States, avoiding US -government regulations which prohibit good privacy protection. -FreeS/WAN version 1.0 is available immediately for downloading at -http://www.xs4all.nl/~freeswan/. - -"Today's FreeS/WAN release allows network administrators to build -excellent secure gateways out of old PCs at no cost, or using a cheap -new PC," said John Gilmore, the entrepreneur who instigated the -project in 1996. "They can build operational experience with strong -network encryption and protect their users' most important -communications worldwide." - -"The software was written outside the United States, and we do not -accept contributions from US citizens or residents, so that it can be -freely published for use in every country," said Henry Spencer, who -built the release in Toronto, Canada. "Similar products based in the -US require hard-to-get government export licenses before they can be -provided to non-US users, and can never be simply published on a Web -site. Our product is freely available worldwide for immediate -downloading, at no cost." - -FreeS/WAN provides privacy against both quiet eavesdropping (such as -"packet sniffing") and active attempts to compromise communications -(such as impersonating participating computers). Secure "tunnels" carry -information safely across the Internet between locations such as a -company's main office, distant sales offices, and roaming laptops. This -protects the privacy and integrity of all information sent among those -locations, including sensitive intra-company email, financial transactions -such as mergers and acquisitions, business negotiations, personal medical -records, privileged correspondence with lawyers, and information about -crimes or civil rights violations. The software will be particularly -useful to frequent wiretapping targets such as private companies competing -with government-owned companies, civil rights groups and lawyers, -opposition political parties, and dissidents. - -FreeS/WAN provides privacy for Internet packets using the proposed -standard Internet Protocol Security (IPSEC) protocols. FreeS/WAN -negotiates strong keys using Diffie-Hellman key agreement with 1024-bit -keys, and encrypts each packet with 168-bit Triple-DES (3DES). A modern -$500 PC can set up a tunnel in less than a second, and can encrypt -6 megabits of packets per second, easily handling the whole available -bandwidth at the vast majority of Internet sites. In preliminary testing, -FreeS/WAN interoperated with 3DES IPSEC products from OpenBSD, PGP, SSH, -Cisco, Raptor, and Xedia. Since FreeS/WAN is distributed as source code, -its innards are open to review by outside experts and sophisticated users, -reducing the chance of undetected bugs or hidden security compromises. - -The software has been in development for several years. It has been -funded by several philanthropists interested in increased privacy on -the Internet, including John Gilmore, co-founder of the Electronic -Frontier Foundation, a leading online civil rights group. - -Press contacts: -Hugh Daniel, +1 408 353 8124, hugh@toad.com -Henry Spencer, +1 416 690 6561, henry@spsystems.net - -* FreeS/WAN derives its name from S/WAN, which is a trademark of RSA Data - Security, Inc; used by permission.</PRE> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="umltesting.html">Previous</A> -<A HREF="ipsec.html">Next</A> -</BODY> -</HTML> diff --git a/doc/quickstart.html b/doc/quickstart.html deleted file mode 100644 index 44d73abc5..000000000 --- a/doc/quickstart.html +++ /dev/null @@ -1,323 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="upgrading.html">Previous</A> -<A HREF="policygroups.html">Next</A> -<HR> -<H1><A name="quickstart">Quickstart Guide to Opportunistic Encryption</A> -</H1> -<A name="quick_guide"></A> -<H2><A name="opp.setup">Purpose</A></H2> -<P>This page will get you started using Linux FreeS/WAN with - opportunistic encryption (OE). OE enables you to set up IPsec tunnels - without co-ordinating with another site administrator, and without hand - configuring each tunnel. If enough sites support OE, a "FAX effect" - occurs, and many of us can communicate without eavesdroppers.</P> -<H3><A NAME="3_1_1">OE "flag day"</A></H3> -<P>As of FreeS/WAN 2.01, OE uses DNS TXT resource records (RRs) only - (rather than TXT with KEY). This change causes a<A href="http://jargon.watson-net.com/jargon.asp?w=flag+day"> - "flag day"</A>. Users of FreeS/WAN 2.00 (or earlier) OE who are - upgrading may require additional resource records, as detailed in our<A href="upgrading.html#upgrading.flagday"> - upgrading document</A>. OE setup instructions here are for 2.02 or - later.</P> -<H2><A name="opp.dns">Requirements</A></H2> -<P>To set up opportunistic encryption, you will need:</P> -<UL> -<LI>a Linux box. For OE to the public Internet, this box must NOT be - behind<A HREF="glossary.html#NAT.gloss"> Network Address Translation</A> - (NAT).</LI> -<LI>to install Linux FreeS/WAN 2.02 or later</LI> -<LI>either control over your reverse DNS (for full opportunism) or the - ability to write to some forward domain (for initiator-only).<A HREF="http://www.fdns.net"> - This free DNS service</A> explicitly supports forward TXT records for - FreeS/WAN use.</LI> -<LI>(for full opportunism) a static IP</LI> -</UL> -<P>Note: Currently, only Linux FreeS/WAN supports opportunistic - encryption.</P> -<H2><A name="easy.install">RPM install</A></H2> -<P>Our instructions are for a recent Red Hat with a 2.4-series stock or - Red Hat updated kernel. For other ways to install, see our<A href="install.html#install"> - install document</A>.</P> -<H3><A NAME="3_3_1">Download RPMs</A></H3> -<P>If we have prebuilt RPMs for your Red Hat system, this command will - get them:</P> -<PRE> ncftpget ftp://ftp.xs4all.nl/pub/crypto/freeswan/binaries/RedHat-RPMs/`uname -r | tr -d 'a-wy-z'`/\*</PRE> -<P>If that fails, you will need to try<A HREF="install.html"> another - install method</A>. Our kernel modules<B> will only work on the Red Hat - kernel they were built for</B>, since they are very sensitive to small - changes in the kernel.</P> -<P>If it succeeds, you will have userland tools, a kernel module, and an - RPM signing key:</P> -<PRE> freeswan-module-2.04_2.4.20_20.9-0.i386.rpm - freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm - freeswan-rpmsign.asc</PRE> -<H3><A NAME="3_3_2">Check signatures</A></H3> -<P>If you're running RedHat 8.x or later, import the RPM signing key - into the RPM database:</P> -<PRE> rpm --import freeswan-rpmsign.asc</PRE> -<P>For RedHat 7.x systems, you'll need to add it to your<A HREF="glossary.html#PGP"> - PGP</A> keyring:</P> -<PRE> pgp -ka freeswan-rpmsign.asc</PRE> -<P>Check the digital signatures on both RPMs using:</P> -<PRE> rpm --checksig freeswan*.rpm </PRE> -<P>You should see that these signatures are good:</P> -<PRE> freeswan-module-2.04_2.4.20_20.9-0.i386.rpm: pgp md5 OK - freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm: pgp md5 OK</PRE> -<H3><A NAME="3_3_3">Install the RPMs</A></H3> -<P>Become root:</P> -<PRE> su</PRE> -<P>Install your RPMs with:</P> -<P></P> -<PRE> rpm -ivh freeswan*.rpm</PRE> -<P>If you're upgrading from FreeS/WAN 1.x RPMs, and have problems with - that command, see<A HREF="upgrading.html#upgrading.rpms"> this note</A> -.</P> -<P>Then, start FreeS/WAN:</P> -<PRE> service ipsec start</PRE> -<H3><A name="testinstall">Test</A></H3> -<P>To check that you have a successful install, run:</P> -<PRE> ipsec verify</PRE> -<P>You should see as part of the<VAR> verify</VAR> output:</P> -<PRE> - Checking your system to see if IPsec got installed and started correctly - Version check and ipsec on-path [OK] - Checking for KLIPS support in kernel [OK] - Checking for RSA private key (/etc/ipsec.secrets) [OK] - Checking that pluto is running [OK] - ...</PRE> -<P>If any of these first four checks fails, see our<A href="trouble.html#install.check"> - troubleshooting guide</A>.</P> -<H2><A name="opp.setups.list">Our Opportunistic Setups</A></H2> -<H3><A NAME="3_4_1">Full or partial opportunism?</A></H3> -<P>Determine the best form of opportunism your system can support.</P> -<UL> -<LI>For<A HREF="#opp.incoming"> full opportunism</A>, you'll need a - static IP and and either control over your reverse DNS or an ISP that - can add the required TXT record for you.</LI> -<LI>If you have a dynamic IP, and/or write access to forward DNS only, - you can do<A HREF="#opp.client"> initiate-only opportunism</A></LI> -<LI>To protect traffic bound for real IPs behind your gateway, use<A HREF="adv_config.html#opp.gate"> - this form of full opportunism</A>.</LI> -</UL> -<H2><A name="opp.client">Initiate-only setup</A></H2> -<H3><A NAME="3_5_1">Restrictions</A></H3> -<P>When you set up initiate-only Opportunistic Encryption (iOE):</P> -<UL> -<LI>there will be<STRONG> no incoming connection requests</STRONG>; you - can initiate all the IPsec connections you need.</LI> -<LI><STRONG>only one machine is visible</STRONG> on your end of the - connection.</LI> -<LI>iOE also protects traffic on behalf of<A HREF="glossary.html#NAT.gloss"> - NATted</A> hosts behind the iOE box.</LI> -</UL> -<P>You cannot network a group of initiator-only machines if none of - these is capable of responding to OE. If one is capable of responding, - you may be able to create a hub topology using routing.</P> -<H3><A name="forward.dns">Create and publish a forward DNS record</A></H3> -<H4>Find a domain you can use</H4> -<P>Find a DNS forward domain (e.g. example.com) where you can publish - your key. You'll need access to the DNS zone files for that domain. - This is common for a domain you own. Some free DNS providers, such as<A HREF="http://www.fdns.net"> - this one</A>, also provide this service.</P> -<P>Dynamic IP users take note: the domain where you place your key need - not be associated with the IP address for your system, or even with - your system's usual hostname.</P> -<H4>Choose your ID</H4> -<P>Choose a name within that domain which you will use to identify your - machine. It's convenient if this can be the same as your hostname:</P> -<PRE> [root@xy root]# hostname --fqdn - xy.example.com</PRE> -<P>This name in FQDN (fully-qualified domain name) format will be your - ID, for DNS key lookup and IPsec negotiation.</P> -<H4>Create a forward TXT record</H4> -<P>Generate a forward TXT record containing your system's public key - with a command like:</P> -<PRE> ipsec showhostkey --txt @xy.example.com</PRE> -<P>using your chosen ID in place of xy.example.com. This command takes - the contents of /etc/ipsec.secrets and reformats it into something - usable by ISC's BIND. The result should look like this (with the key - data trimmed down for clarity):</P> -<PRE> - ; RSA 2192 bits xy.example.com Thu Jan 2 12:41:44 2003 - IN TXT "X-IPsec-Server(10)=@xy.example.com" - "AQOF8tZ2... ...+buFuFn/" -</PRE> -<H4>Publish the forward TXT record</H4> -<P>Insert the record into DNS, or have a system adminstrator do it for - you. It may take up to 48 hours for the record to propagate, but it's - usually much quicker.</P> -<H3><A NAME="3_5_3">Test that your key has been published</A></H3> -<P>Check your DNS work</P> -<PRE> ipsec verify --host xy.example.com</PRE> -<P>As part of the<VAR> verify</VAR> output, you ought to see something - like:</P> -<PRE> ... - Looking for TXT in forward map: xy.example.com [OK] - ...</PRE> -<P>For this type of opportunism, only the forward test is relevant; you - can ignore the tests designed to find reverse records.</P> -<H3><A NAME="3_5_4">Configure, if necessary</A></H3> -<P> If your ID is the same as your hostname, you're ready to go. - FreeS/WAN will use its<A HREF="policygroups.html"> built-in connections</A> - to create your iOE functionality.</P> -<P>If you have chosen a different ID, you must tell FreeS/WAN about it - via<A HREF="manpage.d/ipsec.conf.5.html"><VAR> ipsec.conf</VAR></A>:</P> -<PRE> config setup - myid=@myname.freedns.example.com</PRE> -<P>and restart FreeS/WAN:</P> -<PRE> service ipsec restart</PRE> -<P>The new ID will be applied to the built-in connections.</P> -<P>Note: you can create more complex iOE configurations as explained in - our<A HREF="policygroups.html#policygroups"> policy groups document</A> -, or disable OE using<A HREF="policygroups.html#disable_policygroups"> - these instructions</A>.</P> -<H3><A NAME="3_5_5">Test</A></H3> -<P>That's it!<A HREF="#opp.test"> Test your connections</A>.</P> -<A name="opp.incoming"></A> -<H2><A NAME="3_6">Full Opportunism</A></H2> -<P>Full opportunism allows you to initiate and receive opportunistic - connections on your machine.</P> -<A name="incoming.opp.dns"></A> -<H3><A NAME="3_6_1">Put a TXT record in a Forward Domain</A></H3> -<P>To set up full opportunism, first<A HREF="#forward.dns"> set up a - forward TXT record</A> as for<A HREF="#opp.client"> initiator-only OE</A> -, using an ID (for example, your hostname) that resolves to your IP. Do - not configure<VAR> /etc/ipsec.conf</VAR>, but continue with the - instructions for full opportunism, below.</P> -<P>Note that this forward record is not currently necessary for full OE, - but will facilitate future features.</P> -<A name="incoming.opp.dns"></A> -<H3><A NAME="3_6_2">Put a TXT record in Reverse DNS</A></H3> -<P>You must be able to publish your DNS RR directly in the reverse - domain. FreeS/WAN will not follow a PTR which appears in the reverse, - since a second lookup at connection start time is too costly.</P> -<H4>Create a Reverse DNS TXT record</H4> -<P>This record serves to publicize your FreeS/WAN public key. In - addition, it lets others know that this machine can receive - opportunistic connections, and asserts that the machine is authorized - to encrypt on its own behalf.</P> -<P>Use the command:</P> -<PRE> ipsec showhostkey --txt 192.0.2.11</PRE> -<P>where you replace 192.0.2.11 with your public IP.</P> -<P>The record (with key shortened) looks like:</P> -<PRE> ; RSA 2048 bits xy.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/"</PRE> -<H4>Publish your TXT record</H4> -<P>Send these records to your ISP, to be published in your IP's reverse - map. It may take up to 48 hours for these to propagate, but usually - takes much less time.</P> -<H3><A NAME="3_6_3">Test your DNS record</A></H3> -<P>Check your DNS work with</P> -<PRE> ipsec verify --host xy.example.com</PRE> -<P>As part of the<VAR> verify</VAR> output, you ought to see something - like:</P> -<PRE> ... - Looking for TXT in reverse map: 11.2.0.192.in-addr.arpa [OK] - ...</PRE> -<P>which indicates that you've passed the reverse-map test.</P> -<H3><A NAME="3_6_4">No Configuration Needed</A></H3> -<P>FreeS/WAN 2.x ships with full OE enabled, so you don't need to - configure anything. To enable OE out of the box, FreeS/WAN 2.x uses the - policy group<VAR> private-or-clear</VAR>, which creates IPsec - connections if possible (using OE if needed), and allows traffic in the - clear otherwise. You can create more complex OE configurations as - described in our<A HREF="policygroups.html#policygroups"> policy groups - document</A>, or disable OE using<A HREF="policygroups.html#disable_policygroups"> - these instructions</A>.</P> -<P>If you've previously configured for initiator-only opportunism, - remove<VAR> myid=</VAR> from<VAR> config setup</VAR>, so that peer - FreeS/WANs will look up your key by IP. Restart FreeS/WAN so that your - change will take effect, with</P> -<PRE> service ipsec restart</PRE> -<H3><A NAME="3_6_5">Consider Firewalling</A></H3> -<P>If you are running a default install of RedHat 8.x, take note: you - will need to alter your iptables rule setup to allow IPSec traffic - through your firewall. See<A HREF="firewall.html#simple.rules"> our - firewall document</A> for sample<VAR> iptables</VAR> rules.</P> -<H3><A NAME="3_6_6">Test</A></H3> -<P>That's it. Now,<A HREF="#opp.test"> test your connection</A>.</P> -<H3><A NAME="3_6_7">Test</A></H3> -<P>Instructions are in the next section.</P> -<H2><A NAME="opp.test">Testing opportunistic connections</A></H2> -<P>Be sure IPsec is running. You can see whether it is with:</P> -<PRE> ipsec setup status</PRE> -<P>If need be, you can restart it with:</P> -<PRE> service ipsec restart</PRE> -<P>Load a FreeS/WAN test website from the host on which you're running - FreeS/WAN. Note: the feds may be watching these sites. Type one of:</P> -<P></P> -<PRE> links oetest.freeswan.org</PRE> -<PRE> links oetest.freeswan.nl</PRE> - -<!--<PRE> links oetest.freeswan.ca</PRE>--> -<P>A positive result looks like this:</P> -<PRE> - You seem to be connecting from: 192.0.2.11 which DNS says is: - gateway.example.com - _________________________________________________________________ - - Status E-route - OE enabled 16 192.139.46.73/32 -> 192.0.2.11/32 => - tun0x2097@192.0.2.11 - OE enabled 176 192.139.46.77/32 -> 192.0.2.11/32 => - tun0x208a@192.0.2.11 -</PRE> -<P>If you see this, congratulations! Your OE host or gateway will now - encrypt its own traffic whenever it can. For more OE tests, please see - our<A HREF="testing.html#test.oe"> testing document</A>. If you have - difficulty, see our<A HREF="#oe.trouble"> OE troubleshooting tips</A>.</P> -<H2><A NAME="3_8">Now what?</A></H2> -<P>Please see our<A HREF="policygroups.html"> policy groups document</A> - for more ways to set up Opportunistic Encryption.</P> -<P>You may also wish to make some<A HREF="config.html"> pre-configured - connections</A>.</P> -<H2><A NAME="3_9">Notes</A></H2> -<UL> -<LI>We assume some facts about your system in order to make - Opportunistic Encryption easier to configure. For example, we assume - that you wish to have FreeS/WAN secure your default interface.</LI> -<LI>You may change this, and other settings, by altering the<VAR> config - setup</VAR> section in<VAR> /etc/ipsec.conf</VAR>.</LI> -<LI>Note that the built-in connections used to build policy groups do - not inherit from<VAR> conn default</VAR>.</LI> - -<!-- -<LI>If you do not define your local identity -(eg. <VAR>leftid</VAR>), this will be the IP address of your default -FreeS/WAN interface. ---> -<LI> If you fail to define your local identity and do not fill in your - reverse DNS entry, you will not be able to use OE.</LI> -</UL> -<A NAME="oe.trouble"></A> -<H2><A NAME="3_10">Troubleshooting OE</A></H2> -<P>See the OE troubleshooting hints in our<A HREF="trouble.html#oe.trouble"> - troubleshooting guide</A>.</P> -<A NAME="oe.known-issues"></A> -<H2><A NAME="3_11">Known Issues</A></H2> -<P>Please see<A HREF="opportunism.known-issues"> this list</A> of known - issues with Opportunistic Encryption.</P> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="upgrading.html">Previous</A> -<A HREF="policygroups.html">Next</A> -</BODY> -</HTML> diff --git a/doc/rfc.html b/doc/rfc.html deleted file mode 100644 index 29785d8de..000000000 --- a/doc/rfc.html +++ /dev/null @@ -1,135 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="biblio.html">Previous</A> -<A HREF="roadmap.html">Next</A> -<HR> -<H1><A name="RFC">IPsec RFCs and related documents</A></H1> -<H2><A name="RFCfile">The RFCs.tar.gz Distribution File</A></H2> -<P>The Linux FreeS/WAN distribution is available from<A href="http://www.xs4all.nl/~freeswan"> - our primary distribution site</A> and various mirror sites. To give - people more control over their downloads, the RFCs that define IP - security are bundled separately in the file RFCs.tar.gz.</P> -<P>The file you are reading is included in the main distribution and is - available on the web site. It describes the RFCs included in the<A href="#RFCs.tar.gz"> - RFCs.tar.gz</A> bundle and gives some pointers to<A href="#sources"> - other ways to get them</A>.</P> -<H2><A name="sources">Other sources for RFCs & Internet drafts</A></H2> -<H3><A name="RFCdown">RFCs</A></H3> -<P>RFCs are downloadble at many places around the net such as:</P> -<UL> -<LI><A href="http://www.rfc-editor.org">http://www.rfc-editor.org</A></LI> -<LI><A href="http://nis.nsf.net/internet/documents/rfc">NSF.net</A></LI> -<LI><A href="http://sunsite.doc.ic.ac.uk/computing/internet/rfc">Sunsite - in the UK</A></LI> -</UL> -<P>browsable in HTML form at others such as:</P> -<UL> -<LI><A href="http://www.landfield.com/rfcs/index.html">landfield.com</A></LI> -<LI><A href="http://www.library.ucg.ie/Connected/RFC">Connected Internet - Encyclopedia</A></LI> -</UL> -<P>and some of them are available in translation:</P> -<UL> -<LI><A href="http://www.eisti.fr/eistiweb/docs/normes/">French</A></LI> -</UL> -<P>There is also a published<A href="biblio.html#RFCs"> Big Book of - IPSEC RFCs</A>.</P> -<H3><A name="drafts">Internet Drafts</A></H3> -<P>Internet Drafts, working documents which sometimes evolve into RFCs, - are also available.</P> -<UL> -<LI><A href="http://www.ietf.org/ID.html">Overall reference page</A></LI> -<LI><A href="http://www.ietf.org/ids.by.wg/ipsec.html">IPsec</A> working - group</LI> -<LI><A href="http://www.ietf.org/ids.by.wg/ipsra.html">IPSRA (IPsec - Remote Access)</A> working group</LI> -<LI><A href="http://www.ietf.org/ids.by.wg/ipsp.html">IPsec Policy</A> - working group</LI> -<LI><A href="http://www.ietf.org/ids.by.wg/kink.html">KINK (Kerberized - Internet Negotiation of Keys)</A> working group</LI> -</UL> -<P>Note: some of these may be obsolete, replaced by later drafts or by - RFCs.</P> -<H3><A name="FIPS1">FIPS standards</A></H3> -<P>Some things used by<A href="glossary.html#IPSEC"> IPsec</A>, such as<A -href="glossary.html#DES"> DES</A> and<A href="glossary.html#SHA"> SHA</A> -, are defined by US government standards called<A href="glossary.html#FIPS"> - FIPS</A>. The issuing organisation,<A href="glossary.html#NIST"> NIST</A> -, have a<A href="http://www.itl.nist.gov/div897/pubs"> FIPS home page</A> -.</P> -<H2><A name="RFCs.tar.gz">What's in the RFCs.tar.gz bundle?</A></H2> -<P>All filenames are of the form rfc*.txt, with the * replaced with the - RFC number.</P> -<PRE>RFC# Title</PRE> -<H3><A name="rfc.ov">Overview RFCs</A></H3> -<PRE>2401 Security Architecture for the Internet Protocol -2411 IP Security Document Roadmap</PRE> -<H3><A name="basic.prot">Basic protocols</A></H3> -<PRE>2402 IP Authentication Header -2406 IP Encapsulating Security Payload (ESP)</PRE> -<H3><A name="key.ike">Key management</A></H3> -<PRE>2367 PF_KEY Key Management API, Version 2 -2407 The Internet IP Security Domain of Interpretation for ISAKMP -2408 Internet Security Association and Key Management Protocol (ISAKMP) -2409 The Internet Key Exchange (IKE) -2412 The OAKLEY Key Determination Protocol -2528 Internet X.509 Public Key Infrastructure</PRE> -<H3><A name="rfc.detail">Details of various things used</A></H3> -<PRE>2085 HMAC-MD5 IP Authentication with Replay Prevention -2104 HMAC: Keyed-Hashing for Message Authentication -2202 Test Cases for HMAC-MD5 and HMAC-SHA-1 -2207 RSVP Extensions for IPSEC Data Flows -2403 The Use of HMAC-MD5-96 within ESP and AH -2404 The Use of HMAC-SHA-1-96 within ESP and AH -2405 The ESP DES-CBC Cipher Algorithm With Explicit IV -2410 The NULL Encryption Algorithm and Its Use With IPsec -2451 The ESP CBC-Mode Cipher Algorithms -2521 ICMP Security Failures Messages</PRE> -<H3><A name="rfc.ref">Older RFCs which may be referenced</A></H3> -<PRE>1321 The MD5 Message-Digest Algorithm -1828 IP Authentication using Keyed MD5 -1829 The ESP DES-CBC Transform -1851 The ESP Triple DES Transform -1852 IP Authentication using Keyed SHA</PRE> -<H3><A name="rfc.dns">RFCs for secure DNS service, which IPsec may use</A> -</H3> -<PRE>2137 Secure Domain Name System Dynamic Update -2230 Key Exchange Delegation Record for the DNS -2535 Domain Name System Security Extensions -2536 DSA KEYs and SIGs in the Domain Name System (DNS) -2537 RSA/MD5 KEYs and SIGs in the Domain Name System (DNS) -2538 Storing Certificates in the Domain Name System (DNS) -2539 Storage of Diffie-Hellman Keys in the Domain Name System (DNS)</PRE> -<H3><A name="rfc.exp">RFCs labelled "experimental"</A></H3> -<PRE>2521 ICMP Security Failures Messages -2522 Photuris: Session-Key Management Protocol -2523 Photuris: Extended Schemes and Attributes</PRE> -<H3><A name="rfc.rel">Related RFCs</A></H3> -<PRE>1750 Randomness Recommendations for Security -1918 Address Allocation for Private Internets -1984 IAB and IESG Statement on Cryptographic Technology and the Internet -2144 The CAST-128 Encryption Algorithm</PRE> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="biblio.html">Previous</A> -<A HREF="roadmap.html">Next</A> -</BODY> -</HTML> diff --git a/doc/roadmap.html b/doc/roadmap.html deleted file mode 100644 index ce547582c..000000000 --- a/doc/roadmap.html +++ /dev/null @@ -1,167 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="rfc.html">Previous</A> -<A HREF="umltesting.html">Next</A> -<HR> -<H1><A name="roadmap">Distribution Roadmap: What's Where in Linux - FreeS/WAN</A></H1> -<P> This file is a guide to the locations of files within the FreeS/WAN - distribution. Everything described here should be on your system once - you download, gunzip, and untar the distribution.</P> -<P>This distribution contains two major subsystems</P> -<DL> -<DT><A href="#klips.roadmap">KLIPS</A></DT> -<DD>the kernel code</DD> -<DT><A href="#pluto.roadmap">Pluto</A></DT> -<DD>the user-level key-management daemon</DD> -</DL> -<P>plus assorted odds and ends.</P> -<H2><A name="top">Top directory</A></H2> -<P>The top directory has essential information in text files:</P> -<DL> -<DT>README</DT> -<DD>introduction to the software</DD> -<DT>INSTALL</DT> -<DD>short experts-only installation procedures. More detalied procedures - are in<A href="install.html"> installation</A> and<A href="config.html"> - configuration</A> HTML documents.</DD> -<DT>BUGS</DT> -<DD>major known bugs in the current release.</DD> -<DT>CHANGES</DT> -<DD>changes from previous releases</DD> -<DT>CREDITS</DT> -<DD>acknowledgement of contributors</DD> -<DT>COPYING</DT> -<DD>licensing and distribution information</DD> -</DL> -<H2><A name="doc">Documentation</A></H2> -<P> The doc directory contains the bulk of the documentation, most of it - in HTML format. See the<A href="index.html"> index file</A> for - details.</P> -<H2><A name="klips.roadmap">KLIPS: kernel IP security</A></H2> -<P><A href="glossary.html#KLIPS"> KLIPS</A> is<STRONG> K</STRONG>erne<STRONG> -L</STRONG><STRONG> IP</STRONG><STRONG> S</STRONG>ecurity. It lives in - the klips directory, of course.</P> -<DL> -<DT>klips/doc</DT> -<DD>documentation</DD> -<DT>klips/patches</DT> -<DD>patches for existing kernel files</DD> -<DT>klips/test</DT> -<DD>test stuff</DD> -<DT>klips/utils</DT> -<DD>low-level user utilities</DD> -<DT>klips/net/ipsec</DT> -<DD>actual klips kernel files</DD> -<DT>klips/src</DT> -<DD>symbolic link to klips/net/ipsec -<P>The "make insert" step of installation installs the patches and makes - a symbolic link from the kernel tree to klips/net/ipsec. The odd name - of klips/net/ipsec is dictated by some annoying limitations of the - scripts which build the Linux kernel. The symbolic-link business is a - bit messy, but all the alternatives are worse.</P> -<P></P> -</DD> -<DT>klips/utils</DT> -<DD>Utility programs: -<P></P> -<DL> -<DT>eroute</DT> -<DD>manipulate IPsec extended routing tables</DD> -<DT>klipsdebug</DT> -<DD>set Klips (kernel IPsec support) debug features and level</DD> -<DT>spi</DT> -<DD>manage IPsec Security Associations</DD> -<DT>spigrp</DT> -<DD>group/ungroup IPsec Security Associations</DD> -<DT>tncfg</DT> -<DD>associate IPsec virtual interface with real interface</DD> -</DL> -<P>These are all normally invoked by ipsec(8) with commands such as</P> -<PRE> ipsec tncfg <VAR>arguments</VAR></PRE> - There are section 8 man pages for all of these; the names have "ipsec_" - as a prefix, so your man command should be something like: -<PRE> man 8 ipsec_tncfg</PRE> -</DD> -</DL> -<H2><A name="pluto.roadmap">Pluto key and connection management daemon</A> -</H2> -<P><A href="glossary.html#Pluto"> Pluto</A> is our key management and - negotiation daemon. It lives in the pluto directory, along with its - low-level user utility, whack.</P> -<P> There are no subdirectories. Documentation is a man page,<A href="manpage.d/ipsec_pluto.8.html"> - pluto.8</A>. This covers whack as well.</P> -<H2><A name="utils">Utils</A></H2> -<P> The utils directory contains a growing collection of higher-level - user utilities, the commands that administer and control the software. - Most of the things that you will actually have to run yourself are in - there.</P> -<DL> -<DT>ipsec</DT> -<DD>invoke IPsec utilities -<P>ipsec(8) is normally the only program installed in a standard - directory, /usr/local/sbin. It is used to invoke the others, both those - listed below and the ones in klips/utils mentioned above.</P> -<P></P> -</DD> -<DT>auto</DT> -<DD>control automatically-keyed IPsec connections</DD> -<DT>manual</DT> -<DD>take manually-keyed IPsec connections up and down</DD> -<DT>barf</DT> -<DD>generate copious debugging output</DD> -<DT>look</DT> -<DD>generate moderate amounts of debugging output</DD> -</DL> -<P> There are .8 manual pages for these. look is covered in barf.8. The - man pages have an "ipsec_" prefix so your man command should be - something like:</P> -<PRE> - man 8 ipsec_auto -</PRE> -<P> Examples are in various files with names utils/*.eg</P> -<H2><A name="lib">Libraries</A></H2> -<H3><A name="fswanlib">FreeS/WAN Library</A></H3> -<P> The lib directory is the FreeS/WAN library, also steadily growing, - used by both user-level and kernel code. -<BR /> It includes section 3<A href="manpages.html"> man pages</A> for - the library routines.</P> -<H3><A name="otherlib">Imported Libraries</A></H3> -<H4>LibDES</H4> - The libdes library, originally from SSLeay, is used by both Klips and - Pluto for<A href="glossary.html#3DES"> Triple DES</A> encryption. - Single DES is not used because<A href="politics.html#desnotsecure"> it - is insecure</A>. -<P> Note that this library has its own license, different from the<A href="glossary.html#GPL"> - GPL</A> used for other code in FreeS/WAN.</P> -<P> The library includes its own documentation.</P> -<H4>GMP</H4> - The GMP (GNU multi-precision) library is used for multi-precision - arithmetic in Pluto's key-exchange code and public key code. -<P> Older versions (up to 1.7) of FreeS/WAN included a copy of this - library in the FreeS/WAN distribution.</P> -<P> Since 1.8, we have begun to rely on the system copy of GMP.</P> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="rfc.html">Previous</A> -<A HREF="umltesting.html">Next</A> -</BODY> -</HTML> diff --git a/doc/src/.cvsignore b/doc/src/.cvsignore deleted file mode 100644 index 3ed29bc59..000000000 --- a/doc/src/.cvsignore +++ /dev/null @@ -1,3 +0,0 @@ -foo.xml -foobar.html -makecheck-2.html diff --git a/doc/src/adv_config.html b/doc/src/adv_config.html deleted file mode 100644 index ab6901b5e..000000000 --- a/doc/src/adv_config.html +++ /dev/null @@ -1,1412 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>Advanced FreeS/WAN configuration</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, configuration"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Maintained by Claudia Schmeing for same. - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: adv_config.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1><a name="adv_config">Other configuration possibilities</a></h1> - -<p>This document describes various options for FreeS/WAN configuration which -are less used or more complex (often both) than the standard cases described -in our <a href="config.html#config">config</a> and -<a href="quickstart.html#quick_guide">quickstart</a> documents.</p> - -<h2><a name="thumb">Some rules of thumb about configuration</a></h2> - -<h3><a name="cheap.tunnel">Tunnels are cheap</a></h3> - -<p>Nearly all of the overhead in IPsec processing is in the encryption and -authentication of packets. Our <a href="performance.html">performance</a> -document discusses these overheads.</p> - -<p>Beside those overheads, the cost of managing additional tunnels is -trivial. Whether your gateway supports one tunnel or ten just does not -matter. A hundred might be a problem; there is a <a -href="performance.html#biggate">section</a> on this in the performance -document.</p> - -<p>So, in nearly all cases, if using multiple tunnels gives you a reasonable -way to describe what you need to do, you should describe it that way in your -configuration files.</p> - -<p>For example, one user recently asked on a mailing list about this network -configuration:</p> -<pre> netA---gwA---gwB---netB - |----netC - - netA and B are secured netC not. - netA and gwA can not access netC</pre> - -<p>The user had constructed only one tunnel, netA to netB, and wanted to know -how to use ip-route to get netC packets into it. This is entirely -unnecessary. One of the replies was:</p> -<pre> The simplest way and indeed the right way to - solve this problem is to set up two connections: - - leftsubnet=NetA - left=gwA - right=gwB - rightsubnet=NetB - and - leftsubnet=NetA - left=gwA - right=gwB - rightsubnet=NetC</pre> - -<p>This would still be correct even if we added nets D, E, F, -... to the above diagram and needed twenty tunnels.</p> - -<p>Of course another possibility would be to just use one tunnel, with a -subnet mask that includes both netB and netC (or B, C, D, ...). See next -section.</p> - -<p>In general, you can construct as many tunnels as you need. Networks like -netC in this example that do not connect directly to the gateway are fine, as -long as the gateway can route to them.</p> - -<p>The number of tunnels can become an issue if it reaches 50 or so. This is -discussed in the <a href="performance.html#biggate">performance</a> document. -Look there for information on supporting hundreds of Road Warriors from one -gateway.</p> - -<p>If you find yourself with too many tunnels for some reason like having -eight subnets at one location and nine at another so you end up with -9*8=72 tunnels, read the next section here.</p> - -<h3><a name="subnet.size">Subnet sizes</a></h3> - -<p>The subnets used in <var>leftsubnet</var> and <var>rightsubnet</var> can -be of any size that fits your needs, and they need not correspond to physical -networks.</p> - -<p>You adjust the size by changing the <a href="glossary.html#subnet">subnet -mask</a>, the number after the slash in the subnet description. For -example</p> -<ul> - <li>in 192.168.100.0/24 the /24 mask says 24 bits are used to designate the - network. This leave 8 bits to label machines. This subnet has 256 - addresses. .0 and .255 are reserved, so it can have 254 machines.</li> - <li>A subnet with a /23 mask would be twice as large, 512 addresses.</li> - <li>A subnet with a /25 mask would be half the size, 128 addresses.</li> - <li>/0 is the whole Internet</li> - <li>/32 is a single machine</li> -</ul> - -<p>As an example of using these in connection descriptions, suppose your -company's head office has four physical networks using the address ranges:</p> -<dl> - <dt>192.168.100.0/24</dt> - <dd>development</dd> - <dt>192.168.101.0/24</dt> - <dd>production</dd> - <dt>192.168.102.0/24</dt> - <dd>marketing</dd> - <dt>192.168.103.0/24</dt> - <dd>administration</dd> -</dl> - -<p>You can use exactly those subnets in your connection descriptions, or use -larger subnets to grant broad access if required:</p> -<dl> - <dt>leftsubnet=192.168.100.0/24</dt> - <dd>remote hosts can access only development</dd> - <dt>leftsubnet=192.168.100.0/23</dt> - <dd>remote hosts can access development or production</dd> - <dt>leftsubnet=192.168.102.0/23</dt> - <dd>remote hosts can access marketing or administration</dd> - <dt>leftsubnet=192.168.100.0/22</dt> - <dd>remote hosts can access any of the four departments</dd> -</dl> - -<p>or use smaller subnets to restrict access:</p> -<dl> - <dt>leftsubnet=192.168.103.0/24</dt> - <dd>remote hosts can access any machine in administration</dd> - <dt>leftsubnet=192.168.103.64/28</dt> - <dd>remote hosts can access only certain machines in administration.</dd> - <dt>leftsubnet=192.168.103.42/32</dt> - <dd>remote hosts can access only one particular machine in - administration</dd> -</dl> - -<p>To be exact, 192.68.103.64/28 means all addresses whose top 28 bits match -192.168.103.64. There are 16 of these because there are 16 possibilities for -the remainingg 4 bits. Their addresses are 192.168.103.64 to -192.168.103.79.</p> - -<p>Each connection description can use a different subnet if required.</p> - -<p>It is possible to use all the examples above on the same FreeS/WAN -gateway, each in a different connection description, perhaps for different -classes of user or for different remote offices.</p> - -<p>It is also possible to have multiple tunnels using different -<var>leftsubnet</var> descriptions with the same <var>right</var>. For -example, when the marketing manager is on the road he or she might have -access to:</p> -<dl> - <dt>leftsubnet=192.168.102.0/24</dt> - <dd>all machines in marketing</dd> - <dt>192.168.101.32/29</dt> - <dd>some machines in production</dd> - <dt>leftsubnet=192.168.103.42/32</dt> - <dd>one particular machine in administration</dd> -</dl> - -<p>This takes three tunnels, but tunnels are cheap. If the laptop is set up -to build all three tunnels automatically, then he or she can access all these -machines concurrently, perhaps from different windows.</p> - -<h3><a name="example.more">Other network layouts</a></h3> - -<p>Here is the usual network picture for a site-to-site VPN::</p> -<pre> Sunset==========West------------------East=========Sunrise - local net untrusted net local net</pre> - -<p>and for the Road Warrior::</p> -<pre> telecommuter's PC or - traveller's laptop - Sunset==========West------------------East - corporate LAN untrusted net</pre> - -<p>Other configurations are also possible.</p> - -<h4><a name="internet.subnet">The Internet as a big subnet</a></h4> - -<p>A telecommuter might have:</p> -<pre> Sunset==========West------------------East ================= firewall --- the Internet - home network untrusted net corporate network</pre> - -<p>This can be described as a special case of the general subnet-to-subnet -connection. The subnet on the right is 0.0.0.0/0, the whole Internet.</p> - -<p>West (the home gateway) can have its firewall rules set up so that only -IPsec packets to East are allowed out. It will then behave as if its only -connection to the world was a wire to East.</p> - -<p>When machines on the home network need to reach the Internet, they do so -via the tunnel, East and the corporate firewall. From the viewpoint of the -Internet (perhaps of some EvilDoer trying to break in!), those home office -machines are behind the firewall and protected by it.</p> - -<h4><a name="wireless.config">Wireless</a></h4> - -<p>Another possible configuration comes up when you do not trust the local -network, either because you have very high security standards or because your -are using easily-intercepted wireless signals.</p> - -<p>Some wireless networks have built-in encryption called <a -href="glossary.html#WEP">WEP</a>, but its security is dubious. It is a fairly -common practice to use IPsec instead.</p> - -<p>In this case, part of your network may look like this:</p> -<pre> West-----------------------------East == the rest of your network - workstation untrusted wireless net</pre> - -<p>Of course, there would likely be several wireless workstations, each with -its own IPsec tunnel to the East gateway.</p> - -<p>The connection descriptions look much like Road Warrior descriptions:</p> -<ul> - <li>each workstation should have its own unique - <ul> - <li>identifier for IPsec</li> - <li>RSA key</li> - <li>connection description.</li> - </ul> - </li> - <li>on the gateway, use <var>left=%any</var>, or the workstation IP - address</li> - <li>on workstations, <var>left=%defaultroute</var>, or the workstation IP - address</li> - <li><var>leftsubnet=</var> is not used.</li> -</ul> - -<p>The <var>rightsubnet=</var> parameter might be set in any of several -ways:</p> -<dl> - <dt>rightsubnet=0.0.0.0/0</dt> - <dd>allowing workstations to access the entire Internet (see <a - href="#internet.subnet">above</a>)</dd> - <dt>rightsubnet=a.b.c.0/24</dt> - <dd>allowing access to your entire local network</dd> - <dt>rightsubnet=a.b.c.d/32</dt> - <dd>restricting the workstation to connecting to a particular server</dd> -</dl> - -<p>Of course you can mix and match these as required. For example, a -university might allow faculty full Internet access while letting student -laptops connect only to a group of lab machines.</p> - -<h2><a name="choose">Choosing connection types</a></h2> - -<p>One choice you need to make before configuring additional connections is -what type or types of connections you will use. There are several options, -and you can use more than one concurrently.</p> - -<h3><a name="man-auto">Manual vs. automatic keying</a></h3> - -<p>IPsec allows two types of connections, with manual or automatic keying. -FreeS/WAN starts them with commands such as:</p> -<pre> ipsec manual --up <var>name</var> - ipsec auto --up <var>name</var></pre> - -<p>The difference is in how they are keyed.</p> -<dl> - <dt><a href="glossary.html#manual">Manually keyed</a> connections</dt> - <dd>use keys stored in <a - href="manpage.d/ipsec.conf.5.html">ipsec.conf</a>.</dd> - <dt><a href="glossary.html#auto">Automatically keyed</a> connections</dt> - <dd>use keys automatically generated by the Pluto key negotiation daemon. - The key negotiation protocol, <a href="glossary.html#IKE">IKE</a>, must - authenticate the other system. (It is vulnerable to a <a - href="glossary.html#middle">man-in-the-middle attack</a> if used - without authentication.) We currently support two authentication - methods: - <ul> - <li>using shared secrets stored in <a - href="manpage.d/ipsec.secrets.5.html">ipsec.secrets</a>.</li> - <li>RSA <a href="glossary.html#public">public key</a> authentication, - with our machine's private key in <a - href="manpage.d/ipsec.secrets.5.html">ipsec.secrets</a>. Public - keys for other machines may either be placed in <a - href="manpage.d/ipsec.conf.5.html">ipsec.conf</a> or provided via - DNS.</li> - </ul> - <p>A third method, using RSA keys embedded in <a - href="glossary.html#X509">X.509</a> certtificates, is provided by - user <a href="web.html#patch">patches</a>.</p> - </dd> -</dl> - -<p><a href="glossary.html#manual">Manually keyed</a> connections provide -weaker security than <a href="glossary.html#auto">automatically keyed</a> -connections. An opponent who reads ipsec.secrets(5) gets your encryption key -and can read all data encrypted by it. If he or she has an archive of old -messages, all of them back to your last key change are also readable.</p> - -<p>With automatically-(re)-keyed connections, an opponent who reads -ipsec.secrets(5) gets the key used to authenticate your system in IKE -- the -shared secret or your private key, depending what authentication mechanism is -in use. However, he or she does not automatically gain access to any -encryption keys or any data.</p> - -<p>An attacker who has your authentication key can mount a <a -href="glossary.html#middle">man-in-the-middle attack</a> and, if that -succeeds, he or she will get encryption keys and data. This is a serious -danger, but it is better than having the attacker read everyting as soon as -he or she breaks into ipsec.secrets(5).. Moreover, the keys change often so -an opponent who gets one key does not get a large amount of data. To read all -your data, he or she would have to do a man-in-the-middle attack at every key -change.</p> - -<p>We discuss using <a href="#prodman">manual keying in production</a> below, -but this is <strong>not recommended</strong> except in special circumstances, -such as needing to communicate with some implementation that offers no -auto-keyed mode compatible with FreeS/WAN.</p> - -<p>Manual keying may also be useful for testing. There is some discussion of -this in our <a href="faq.html#man4debug">FAQ</a>.</p> - -<h3><a name="auto-auth">Authentication methods for auto-keying</a></h3> - -<p>The IKE protocol which Pluto uses to negotiate connections between -gateways must use some form of authentication of peers. A gateway must know -who it is talking to before it can create a secure connection. We support two -basic methods for this authentication:</p> -<ul> - <li>shared secrets, stored in <a - href="manpage.d/ipsec.secrets.5.html">ipsec.secrets(5)</a></li> - <li>RSA authentication</li> -</ul> - -<p>There are, howver, several variations on the RSA theme, using different -methods of managing the RSA keys:</p> -<ul> - <li>our RSA private key in <a - href="manpage.d/ipsec.secrets.5.html">ipsec.secrets(5)</a> with other - gateways' public keys - <dl> - <dt>either</dt> - <dd>stored in <a - href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a></dd> - <dt>or</dt> - <dd>looked up via <a href="glossary.html#DNS">DNS</a></dd> - </dl> - </li> - <li>authentication with <a href="glossary.html#x509">x.509</a> - certificates.; See our <a href="web.html#patch">links section</a> for - information on user-contributed patches for this.:</li> -</ul> - -<p>Public keys in <a href="manpage.d/ipsec.conf.5.html">ipsec.conf(5</a>) -give a reasonably straightforward method of specifying keys for explicitly -configured connections.</p> - -<p>Putting public keys in DNS allows us to support <a -href="glossary.html#carpediem">opportunistic encryption</a>. Any two -FreeS/WAN gateways can provide secure communication, without either of them -having any preset information about the other.</p> - -<p>X.509 certificates may be required to interface to various <a -href="glossary.html#PKI">PKI</a>s.</p> - -<h3><a name="adv-pk">Advantages of public key methods</a></h3> - -<p>Authentication with a <a href="glossary.html#public">public key</a> method -such as <a href="glossary.html#RSA">RSA</a> has some important advantages -over using shared secrets.</p> -<ul> - <li>no problem of secure transmission of secrets - <ul> - <li>A shared secret must be shared, so you have the problem of - transmitting it securely to the other party. If you get this wrong, - you have no security.</li> - <li>With a public key technique, you transmit only your public key. The - system is designed to ensure that it does not matter if an enemy - obtains public keys. The private key never leaves your machine.</li> - </ul> - </li> - <li>easier management - <ul> - <li>Suppose you have 20 branch offices all connecting to one gateway at - head office, and all using shared secrets. Then the head office admin - has 20 secrets to manage. Each of them must be kept secret not only - from outsiders, but also from 19 of the branch office admins. The - branch office admins have only one secret each to manage. - <p>If the branch offices need to talk to each other, this becomes - problematic. You need another 20*19/2 = 190 secrets for - branch-to-branch communication, each known to exactly two branches. - Now all the branch admins have the headache of handling 20 keys, each - shared with exactly one other branch or with head office.</p> - <p>For larger numbers of branches, the number of connections and - secrets increases quadratically and managing them becomes a - nightmare. A 1000-gateway fully connected network needs 499,500 - secrets, each known to exactly two players. There are ways to reduce - this problem, for example by introducing a central key server, but - these involve additional communication overheads, more administrative - work, and new threats that must be carefully guarded against.</p> - </li> - <li>With public key techniques, the <em>only</em> thing you have to - keep secret is your private key, and <em>you keep that secret from - everyone</em>. - <p>As network size increaes, the number of public keys used increases - linearly with the number of nodes. This still requires careful - administration in large applications, but is nothing like the - disaster of a quadratic increase. On a 1000-gateway network, you have - 1000 private keys, each of which must be kept secure on one machine, - and 1000 public keys which must be distributed. This is not a trivial - problem, but it is manageable.</p> - </li> - </ul> - </li> - <li>does not require fixed IP addresses - <ul> - <li>When shared secrets are used in IPsec, the responder must be able - to tell which secret to use by looking at the IP address on the - incoming packets. When the other parties do not have a fixed IP - address to be identified by (for example, on nearly all dialup ISP - connections and many cable or ADSL links), this does not work well -- - all must share the same secret!</li> - <li>When RSA authentication is in use, the initiator can identify - itself by name before the key must be determined. The responder then - checks that the message is signed with the public key corresponding - to that name.</li> - </ul> - </li> -</ul> - -<p>There is also a disadvantage:</p> -<ul> - <li>your private key is a single point of attack, extremely valuable to an - enemy - <ul> - <li>with shared secrets, an attacker who steals your ipsec.secrets file - can impersonate you or try <a - href="glossary.html#middle">man-in-the-middle</a> attacks, but can - only attack connections described in that file</li> - <li>an attacker who steals your private key gains the chance to attack - not only existing connections <em>but also any future - connections</em> created using that key</li> - </ul> - </li> -</ul> - -<p>This is partly counterbalanced by the fact that the key is never -transmitted and remains under your control at all times. It is likely -necessary, however, to take account of this in setting security policy. For -example, you should change gateway keys when an administrator leaves the -company, and should change them periodically in any case.</p> - -<p>Overall, public key methods are <strong>more secure, more easily managed -and more flexible</strong>. We recommend that they be used for all -connections, unless there is a compelling reason to do otherwise.</p> - -<h2><a name="prodsecrets">Using shared secrets in production</a></h2> - -<p>Generally, public key methods are preferred for reasons given above, but -shared secrets can be used with no loss of security, just more work and -perhaps more need to take precautions.</p> - -<p>What I call "shared secrets" are sometimes also called "pre-shared keys". -They are used only for for authentication, never for encryption. Calling them -"pre-shared keys" has confused some users into thinking they were encryption -keys, so I prefer to avoid the term..</p> - -<p>If you are interoperating with another IPsec implementation, you may find -its documentation calling them "passphrases".</p> - -<h3><a name="secrets">Putting secrets in ipsec.secrets(5)</a></h3> - -<p>If shared secrets are to be used to <a -href="glossary.html#authentication">authenticate</a> communication for the <a -href="glossary.html#DH">Diffie-Hellman</a> key exchange in the <a -href="glossary.html#IKE">IKE</a> protocol, then those secrets must be stored -in <var>/etc/ipsec.secrets</var>. For details, see the <a -href="manpage.d/ipsec.secrets.5.html">ipsec.secrets(5)</a> man page.</p> - -<p>A few considerations are vital:</p> -<ul> - <li>make the secrets long and unguessable. Since they need not be - remembered by humans, very long ugly strings may be used. We suggest - using our <a href="manpage.d/ipsec_ranbits.8.html">ipsec_ranbits(8)</a> - utility to generate long (128 bits or more) random strings.</li> - <li>transmit secrets securely. You have to share them with other systems, - but you lose if they are intercepted and used against you. Use <a - href="glossary.html#PGP">PGP</a>, <a href="glossary.html#SSH">SSH</a>, - hand delivery of a floppy disk which is then destroyed, or some other - trustworthy method to deliver them.</li> - <li>store secrets securely, in root-owned files with permissions - rw------.</li> - <li>limit sharing of secrets. Alice, Bob, Carol and Dave may all talk to - each other, but only Alice and Bob should know the secret for an - Alice-Bob link.</li> - <li><strong>do not share private keys</strong>. The private key for RSA - authentication of your system is stored in <a - href="manpage.d/ipsec.secrets.5.html">ipsec.secrets(5)</a>, but it is a - different class of secret from the pre-shared keys used for the "shared - secret" authentication. No-one but you should have the RSA private - key.</li> -</ul> - -<p>Each line has the IP addresses of the two gateways plus the secret. It -should look something like this:</p> -<pre> 10.0.0.1 11.0.0.1 : PSK "jxTR1lnmSjuj33n4W51uW3kTR55luUmSmnlRUuWnkjRj3UuTV4T3USSu23Uk55nWu5TkTUnjT"</pre> - -<p><var>PSK</var> indicates the use of a -<strong>p</strong>re-<strong>s</strong>hared <strong>k</strong>ey. The quotes -and the whitespace shown are required.</p> - -<p>You can use any character string as your secret. For security, it should -be both long and extremely hard to guess. We provide a utility to generate -such strings, <a -href="manpage.d/ipsec_ranbits.8.html">ipsec_ranbits(8)</a>.</p> - -<p>You want the same secret on the two gateways used, so you create a line -with that secret and the two gateway IP addresses. The installation process -supplies an example secret, useful <em>only</em> for testing. You must change -it for production use.</p> - -<h3><a name="securing.secrets">File security</a></h3> - -<p>You must deliver this file, or the relevant part of it, to the other -gateway machine by some <strong>secure</strong> means. <em>Don't just FTP or -mail the file!</em> It is vital that the secrets in it remain secret. An -attacker who knew those could easily have <em>all the data on your "secure" -connection</em>.</p> - -<p>This file must be owned by root and should have permissions -<var>rw-------</var>.</p> - -<h3><a name="notroadshared">Shared secrets for road warriors</a></h3> - -<p>You can use a shared secret to support a single road warrior connecting to -your gateway, and this is a reasonable thing to do in some circumstances. -Public key methods have advantages, discussed <a href="#choose">above</a>, -but they are not critical in this case.</p> - -<p>To do this, the line in ipsec.secrets(5) is something like:</p> -<pre> 10.0.0.1 0.0.0.0 : PSK "jxTR1lnmSjuj33n4W51uW3kTR55luUmSmnlRUuWnkjRj3UuTV4T3USSu23Uk55nWu5TkTUnjT"</pre> -where the <var>0.0.0.0</var> means that any IP address is acceptable. - -<p><strong>For more than one road warrior, shared secrets are <em>not</em> -recommended.</strong> If shared secrets are used, then when the responder -needs to look up the secret, all it knows about the sender is an IP address. -This is fine if the sender is at a fixed IP address specified in the config -file. It is also fine if only one road warrior uses the wildcard -<var>0.0.0.0</var> address. However, if you have more than one road warrior -using shared secret authentication, then they must all use that wildcard and -therefore <strong>all road warriors using PSK autentication must use the same -secret</strong>. Obviously, this is insecure.</p> - -<p><strong>For multiple road warriors, use public key -authentication.</strong> Each roadwarrior can then have its own identity (our -<var>leftid=</var> or <var>rightid=</var> parameters), its own public/private -key pair, and its own secure connection.</p> - -<h2><a name="prodman">Using manual keying in production</a></h2> - -<p>Generally, <a href="glossary.html#auto">automatic keying</a> is preferred -over <a href="glossary.html#manual">manual keying</a> for production use -because it is both easier to manage and more secure. Automatic keying frees -the admin from much of the burden of managing keys securely, and can provide -<a href="glossary.html#PFS">perfect forward secrecy</a>. This is discussed in -more detail <a href="#man-auto">above</a>.</p> - -<p>However, it is possible to use manual keying in production if that is what -you want to do. This might be necessary, for example, in order to -interoperate with some device that either does not provide automatic keying -or provides it in some version we cannot talk to.</p> - -<p>Note that with manual keying <strong>all security rests with the -keys</strong>. If an adversary acquires your keys, you've had it. He or she -can read everything ever sent with those keys, including old messages he or -she may have archived.</p> - -<p>You need to <strong>be really paranoid about keys</strong> if you're going -to rely on manual keying for anything important.</p> -<ul> - <li>keep keys in files with 600 permissions, owned by root</li> - <li>be extremely careful about security of your gateway systems. Anyone who - breaks into a gateway and gains root privileges can get all your keys and - read everything ever encrypted with those keys, both old messages he has - archived and any new ones you may send.</li> - <li>change keys regularly. This can be a considerable bother, (and provides - an excellent reason to consider automatic keying instead), but it is - <em>absolutely essential</em> for security. Consider a manually keyed - system in which you leave the same key in place for months: - <ul> - <li>an attacker can have a very large sample of text sent with that key - to work with. This makes various cryptographic attacks much more - likely to succeed.</li> - <li>The chances of the key being compromised in some non-cryptographic - manner -- a spy finds it on a discarded notepad, someone breaks into - your server or your building and steals it, a staff member is bribed, - tricked, seduced or coerced into revealing it, etc. -- also increase - over time.</li> - <li>a successful attacker can read everything ever sent with that key. - This makes any successful attack extremely damaging.</li> - </ul> - It is clear that you must change keys often to have any useful security. - The only question is how often.</li> - <li>use <a href="glossary.html#PGP">PGP</a> or <a - href="glossary.html#SSH">SSH</a> for all key transfers</li> - <li>don't edit files with keys in them when someone can look over your - shoulder</li> - <li>worry about network security; could someone get keys by snooping - packets on the LAN between your X desktop and the gateway?</li> - <li>lock up your backup tapes for the gateway system</li> - <li>... and so on</li> -</ul> - -<p>Linux FreeS/WAN provides some facilities to help with this. In particular, -it is good policy to <strong>keep keys in separate files</strong> so you can -edit configuration information in /etc/ipsec.conf without exposing keys to -"shoulder surfers" or network snoops. We support this with the -<var>also=</var> and <var>include</var> syntax in <a -href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a>.</p> - -<p>See the last example in our <a href="examples">examples</a> file. In the -/etc/ipsec.conf <var>conn samplesep</var> section, it has the line:</p> -<pre> also=samplesep-keys</pre> - -<p>which tells the "ipsec manual" script to insert the configuration -description labelled "samplesep-keys" if it can find it. The /etc/ipsec.conf -file must also have a line such as:</p> -<pre>include ipsec.*.conf</pre> - -<p>which tells it to read other files. One of those other files then might -contain the additional data:</p> -<pre>conn samplesep-keys - spi=0x200 - esp=3des-md5-96 - espenckey=0x01234567_89abcdef_02468ace_13579bdf_12345678_9abcdef0 - espauthkey=0x12345678_9abcdef0_2468ace0_13579bdf</pre> - -<p>The first line matches the label in the "also=" line, so the indented -lines are inserted. The net effect is exactly as if the inserted lines had -occurred in the original file in place of the "also=" line.</p> - -<p>Variables set here are:</p> -<dl> - <dt>spi</dt> - <dd>A number needed by the manual keying code. Any 3-digit hex number - will do, but if you have more than one manual connection then - <strong>spi must be different</strong> for each connection.</dd> - <dt>esp</dt> - <dd>Options for <a href="glossary.html#ESP">ESP</a> (Encapsulated - Security Payload), the usual IPsec encryption mode. Settings here are - for <a href="glossary.html#encryption">encryption</a> using <a - href="glossary.html#3DES">triple DES</a> and <a - href="glossary.html#authentication">authentication</a> using <a - href="glossary.html#MD5">MD5</a>. Note that encryption without - authentication should not be used; it is insecure.</dd> - <dt>espenkey</dt> - <dd>Key for ESP encryption. Here, a 192-bit hex number for triple - DES.</dd> - <dt>espauthkey</dt> - <dd>Key for ESP authentication. Here, a 128-bit hex number for MD5.</dd> -</dl> - -<p><strong>Note</strong> that the <strong>example keys we supply</strong> are -intended <strong>only for testing</strong>. For real use, you should go to -automatic keying. If that is not possible, create your own keys for manual -mode and keep them secret</p> - -<p>Of course, any files containing keys <strong>must</strong> have 600 -permissions and be owned by root.</p> - -<p>If you connect in this way to multiple sites, we recommend that you keep -keys for each site in a separate file and adopt some naming convention that -lets you pick them all up with a single "include" line. This minimizes the -risk of losing several keys to one error or attack and of accidentally giving -another site admin keys which he or she has no business knowing.</p> - -<p>Also note that if you have multiple manually keyed connections on a single -machine, then the <var>spi</var> parameter must be different for each one. -Any 3-digit hex number is OK, provided they are different for each -connection. We reserve the range 0x100 to 0xfff for manual connections. Pluto -assigns SPIs from 0x1000 up for automatically keyed connections.</p> - -<p>If <a href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a> contains keys -for manual mode connections, then it too must have permissions -<var>rw-------</var>. We recommend instead that, if you must manual keying in -production, you keep the keys in separate files.</p> - -<p>Note also that <a href="manpage.d/ipsec.conf.5.html">ipsec.conf</a> is -installed with permissions <var>rw-r--r--</var>. If you plan to use manually -keyed connections for anything more than initial testing, you <b>must</b>:</p> -<ul> - <li>either change permissions to <var>rw-------</var></li> - <li>or store keys separately in secure files and access them via include - statements in <a href="manpage.d/ipsec.conf.5.html">ipsec.conf</a>.</li> -</ul> - -<p>We recommend the latter method for all but the simplest configurations.</p> - -<h3><a name="ranbits">Creating keys with ranbits</a></h3> - -<p>You can create new <a href="glossary.html#random">random</a> keys with the -<a href="manpage.d/ipsec_ranbits.8.html">ranbits(8)</a> utility. For example, -the commands:</p> -<pre> umask 177 - ipsec ranbits 192 > temp - ipsec ranbits 128 >> temp</pre> - -<p>create keys in the sizes needed for our default algorithms:</p> -<ul> - <li>192-bit key for <a href="glossary.html#3DES">3DES</a> encryption <br> - (only 168 bits are used; parity bits are ignored)</li> - <li>128-bit key for keyed <a href="glossary.html#MD5">MD5</a> - authentication</li> -</ul> - -<p>If you want to use <a href="glossary.html#SHA">SHA</a> instead of <a -href="glossary.html#MD5">MD5</a>, that requires a 160-bit key</p> - -<p>Note that any <strong>temporary files</strong> used must be kept -<strong>secure</strong> since they contain keys. That is the reason for the -umask command above. The temporary file should be deleted as soon as you are -done with it. You may also want to change the umask back to its default value -after you are finished working on keys.</p> - -<p>The ranbits utility may pause for a few seconds if not enough entropy is -available immediately. See ipsec_ranbits(8) and random(4) for details. You -may wish to provide some activity to feed entropy into the system. For -example, you might move the mouse around, type random characters, or do -<var>du /usr > /dev/null</var> in the background.</p> - -<h2><a name="boot">Setting up connections at boot time</a></h2> - -<p>You can tell the system to set up connections automatically at boot time -by putting suitable stuff in /etc/ipsec.conf on both systems. The relevant -section of the file is labelled by a line reading <var>config setup</var>.</p> - -<p>Details can be found in the <a -href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a> man page. We also -provide a file of <a href="examples">example configurations</a>.</p> - -<p>The most likely options are something like:</p> -<dl> - <dt>interfaces="ipsec0=eth0 ipsec1=ppp0"</dt> - <dd>Tells KLIPS which interfaces to use. Up to four interfaces numbered - ipsec[0-3] are supported. Each interface can support an arbitrary - number of tunnels. - <p>Note that for PPP, you give the ppp[0-9] device name here, not the - underlying device such as modem (or eth1 if you are using PPPoE).</p> - </dd> - <dt>interfaces=%defaultroute</dt> - <dd>Alternative setting, useful in simple cases. KLIPS will pick up both - its interface and the next hop information from the settings of the - Linux default route.</dd> - <dt>forwardcontrol=no</dt> - <dd>Normally "no". Set to "yes" if the IP forwarding option is disabled - in your network configuration. (This can be set as a kernel - configuration option or later. e.g. on Redhat, it's in - /etc/sysconfig/network and on SuSE you can adjust it with Yast.) Linux - FreeS/WAN will then enable forwarding when starting up and turn it off - when going down. This is used to ensure that no packets will be - forwarded before IPsec comes up and takes control.</dd> - <dt>syslog=daemon.error</dt> - <dd>Used in messages to the system logging daemon (syslogd) to specify - what type of software is sending the messages. If the settings are - "daemon.error" as in our example, then syslogd treats the messages as - error messages from a daemon. - <p>Note that <a href="glossary.html#Pluto">Pluto</a> does not currently - pay attention to this variable. The variable controls setup messages - only.</p> - </dd> - <dt>klipsdebug=</dt> - <dd>Debug settings for <a href="glossary.html#KLIPS">KLIPS</a>.</dd> - <dt>plutodebug=</dt> - <dd>Debug settings for <a href="glossary.html#Pluto">Pluto</a>.</dd> - <dt>... for both the above DEBUG settings</dt> - <dd>Normally, leave empty as shown above for no debugging output.<br> - Use "all" for maximum information.<br> - See ipsec_klipsdebug(8) and ipsec_pluto(8) man page for other options. - Beware that if you set /etc/ipsec.conf to enable debug output, your - system's log files may get large quickly.</dd> - <dt>dumpdir=/safe/directory</dt> - <dd>Normally, programs started by ipsec setup don't crash. If they do, by - default, no core dump will be produced because such dumps would contain - secrets. If you find you need to debug such crashes, you can set - dumpdir to the name of a directory in which to collect the core - file.</dd> - <dt>manualstart=</dt> - <dd>List of manually keyed connections to be automatically started at - boot time. Useful for testing, but not for long term use. Connections - which are automatically started should also be automatically - re-keyed.</dd> - <dt>pluto=yes</dt> - <dd>Whether to start <a href="glossary.html#Pluto">Pluto</a> when ipsec - startup is done.<br> - This parameter is optional and defaults to "yes" if not present. - <p>"yes" is strongly recommended for production use so that the keying - daemon (Pluto) will automatically re-key the connections regularly. The - ipsec-auto parameters ikelifetime, ipseclifetime and reykeywindow give - you control over frequency of rekeying.</p> - </dd> - <dt>plutoload="reno-van reno-adam reno-nyc"</dt> - <dd>List of tunnels (by name, e.g. fred-susan or reno-van in our - examples) to be loaded into Pluto's internal database at startup. In - this example, Pluto loads three tunnels into its database when it is - started. - <p>If plutoload is "%search", Pluto will load any connections whose - description includes "auto=add" or "auto=start".</p> - </dd> - <dt>plutostart="reno-van reno-adam reno-nyc"</dt> - <dd>List of tunnels to attempt to negotiate when Pluto is started. - <p>If plutostart is "%search", Pluto will start any connections whose - description includes "auto=start".</p> - <p>Note that, for a connection intended to be permanent, <strong>both - gateways should be set try to start</strong> the tunnel. This allows - quick recovery if either gateway is rebooted or has its IPsec - restarted. If only one gateway is set to start the tunnel and the other - gateway restarts, the tunnel may not be rebuilt.</p> - </dd> - <dt>plutowait=no</dt> - <dd>Controls whether Pluto waits for one tunnel to be established before - starting to negotiate the next. You might set this to "yes" - <ul> - <li>if your gateway is a very limited machine and you need to - conserve resources.</li> - <li>for debugging; the logs are clearer if only one connection is - brought up at a time</li> - </ul> - For a busy and resource-laden production gateway, you likely want "no" - so that connections are brought up in parallel and the whole process - takes less time.</dd> -</dl> - -<p>The example assumes you are at the Reno office and will use IPsec to -Vancouver, New York City and Amsterdam.</p> - -<h2><a name="multitunnel">Multiple tunnels between the same two -gateways</a></h2> - -<p>Consider a pair of subnets, each with a security gateway, connected via -the Internet:</p> -<pre> 192.168.100.0/24 left subnet - | - 192.168.100.1 - North Gateway - 101.101.101.101 left - | - 101.101.101.1 left next hop - [Internet] - 202.202.202.1 right next hop - | - 202.202.202.202 right - South gateway - 192.168.200.1 - | - 192.168.200.0/24 right subnet</pre> - -<p>A tunnel specification such as:</p> -<pre>conn northnet-southnet - left=101.101.101.101 - leftnexthop=101.101.101.1 - leftsubnet=192.168.100.0/24 - leftfirewall=yes - right=202.202.202.202 - rightnexthop=202.202.202.1 - rightsubnet=192.168.200.0/24 - rightfirewall=yes</pre> -will allow machines on the two subnets to talk to each other. You might test -this by pinging from polarbear (192.168.100.7) to penguin (192.168.200.5). - -<p>However, <strong>this does not cover other traffic you might want to -secure</strong>. To handle all the possibilities, you might also want these -connection descriptions:</p> -<pre>conn northgate-southnet - left=101.101.101.101 - leftnexthop=101.101.101.1 - right=202.202.202.202 - rightnexthop=202.202.202.1 - rightsubnet=192.168.200.0/24 - rightfirewall=yes - -conn northnet-southgate - left=101.101.101.101 - leftnexthop=101.101.101.1 - leftsubnet=192.168.100.0/24 - leftfirewall=yes - right=202.202.202.202 - rightnexthop=202.202.202.1</pre> - -<p>Without these, neither gateway can do IPsec to the remote subnet. There is -no IPsec tunnel or eroute set up for the traffic.</p> - -<p>In our example, with the non-routable 192.168.* addresses used, packets -would simply be discarded. In a different configuration, with routable -addresses for the remote subnet, <strong>they would be sent -unencrypted</strong> since there would be no IPsec eroute and there would be -a normal IP route.</p> - -<p>You might also want:</p> -<pre>conn northgate-southgate - left=101.101.101.101 - leftnexthop=101.101.101.1 - right=202.202.202.202 - rightnexthop=202.202.202.1</pre> - -<p>This is required if you want the two gateways to speak IPsec to each -other.</p> - -<p>This requires a lot of duplication of details. Judicious use of -<var>also=</var> and <var>include</var> can reduce this problem.</p> - -<p>Note that, while FreeS/WAN supports all four tunnel types, not all -implementations do. In particular, some versions of Windows 2000 and the -freely downloadable version of PGP provide only "client" functionality. You -cannot use them as gateways with a subnet behind them. To get that -functionality, you must upgrade to Windows 2000 server or the commercially -available PGP products.</p> - -<h3><a name="advroute">One tunnel plus advanced routing</a></h3> -It is also possible to use the new routing features in 2.2 and later kernels -to avoid most needs for multple tunnels. Here is one mailing list message on -the topic: -<pre>Subject: Re: linux-ipsec: IPSec packets not entering tunnel? - Date: Mon, 20 Nov 2000 - From: Justin Guyett <jfg@sonicity.com> - -On Mon, 20 Nov 2000, Claudia Schmeing wrote: - -> Right Left -> "home" "office" -> 10.92.10.0/24 ---- 24.93.85.110 ========= 216.175.164.91 ---- 10.91.10.24/24 -> -> I've created all four tunnels, and can ping to test each of them, -> *except* homegate-officenet. - -I keep wondering why people create all four tunnels. Why not route -traffic generated from home to 10.91.10.24/24 out ipsec0 with iproute2? -And 99% of the time you don't need to access "office" directly, which -means you can eliminate all but the subnet<->subnet connection.</pre> -and FreeS/WAN technical lead Henry Spencer's comment: -<pre>> I keep wondering why people create all four tunnels. Why not route -> traffic generated from home to 10.91.10.24/24 out ipsec0 with iproute2? - -This is feasible, given some iproute2 attention to source addresses, but -it isn't something we've documented yet... (partly because we're still -making some attempt to support 2.0.xx kernels, which can't do this, but -mostly because we haven't caught up with it yet). - -> And 99% of the time you don't need to access "office" directly, which -> means you can eliminate all but the subnet<->subnet connection. - -Correct in principle, but people will keep trying to ping to or from the -gateways during testing, and sometimes they want to run services on the -gateway machines too.</pre> - - -<!-- Is this in the right spot in this document? --> -<H2><A name="opp.gate">An Opportunistic Gateway</A></H2> - -<H3>Start from full opportunism</H3> - -<P>Full opportunism -allows you to initiate and receive opportunistic connections on your -machine. The remaining instructions in this section assume -you have first set up full opportunism on your gateway using -<A HREF="quickstart.html#opp.incoming">these instructions</A>. -Both sets of instructions require mailing DNS records to your ISP. Collect -DNS records for both the gateway (above) and the -subnet nodes (below) before contacting your ISP.</P> - - -<H3>Reverse DNS TXT records for each protected machine</H3> - -<P>You need these so that your Opportunistic peers can: -<UL> -<LI>discover the gateway's address, knowing only the IP address - that packets are bound for</LI> -<LI>verify that the gateway is authorised to encrypt for that endpoint</LI> -</UL> - -<P>On the gateway, generate a TXT record with: -<PRE> ipsec showhostkey --txt 192.0.2.11</PRE> -<P>Use your gateway address in place of 192.0.2.11.</P> - -<P>You should see (keys are trimmed for clarity throughout our example):</P> -<PRE> ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/"</PRE> - -<P><B>This MUST BE the same key as in your gateway's TXT record, or nothing -will work.</B></P> - -<P>In a text file, make one copy of this TXT record for each subnet - node:</P> -<PRE> ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/" - - ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/" - - ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/"</PRE> - -<P>Above each entry, insert a line like this:</P> -<PRE> 98.2.0.192.in-addr.arpa. IN PTR arthur.example.com.</PRE> - -<P>It must include:</P> -<UL> -<LI>The subnet node's address in reverse map format. For example, 192.0.2.120 -becomes <VAR>120.2.0.192.in-addr.arpa.</VAR>. Note the final period.</LI> -<LI><VAR>IN PTR</VAR></LI> -<LI>The node's name, ie. <VAR>arthur.example.com.</VAR>. Note -the final period.</LI> -</UL> - -<P>The result will be a file of TXT records, like this:</P> -<PRE> 98.2.0.192.in-addr.arpa. IN PTR arthur.example.com. - ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/" - - 99.2.0.192.in-addr.arpa. IN PTR ford.example.com. - ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/" - - 100.2.0.192.in-addr.arpa. IN PTR trillian.example.com. - ; RSA 2048 bits gateway.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/"</PRE> - - -<H3>Publish your records</H3> - -<P>Ask your ISP to publish all the reverse DNS records you have collected. -There may be a delay of up to 48 hours as the records propagate.</P> - - -<H3>...and test them</H3> - -<P>Check a couple of records with commands like this one:</P> - -<PRE> ipsec verify --host ford.example.com - ipsec verify --host trillian.example.com</PRE> - -<P>The <var>verify</var> command checks for TXT records for both the -subnet host and its gateway. You should see output like:</P> -<PRE> ... - Looking for TXT in reverse map: 99.2.0.192.in-addr.arpa [OK] - ... - Looking for TXT in reverse map: 11.2.0.192.in-addr.arpa [OK] - ... - Looking for TXT in reverse map: 100.2.0.192.in-addr.arpa [OK] - ... - Looking for TXT in reverse map: 11.2.0.192.in-addr.arpa [OK] - ...</PRE> -<H3>No Configuration Needed</H3> - -<P>FreeS/WAN 2.x ships with a built-in, automatically -enabled OE connection <VAR>conn packetdefault</VAR> -which applies OE, if possible, to all outbound traffic routed -through the FreeS/WAN box. - -The -<A HREF="manpage.d/ipsec.conf.5.html">ipsec.conf(5) manual</A> -describes this connection in detail. -While the effect is much the same as <VAR>private-or-clear</VAR>, -the implementation is different: notably, it does not use policy -groups.</P> - -<P>You can create more complex OE configurations -for traffic forwarded through a FreeS/WAN box, as explained in our -<A HREF="policygroups.html#policygroups">policy groups document</A>, -or disable OE using -<A HREF="policygroups.html#disable_policygroups">these instructions</A>.</P> - - - -<h2><a name="extruded.config">Extruded Subnets</a></h2> - -<p>What we call <a href="glossary.html#extruded">extruded subnets</a> are a -special case of <a href="glossary.html#VPN.gloss">VPNs</a>.</p> - -<p>If your buddy has some unused IP addresses, in his subnet far off at the -other side of the Internet, he can loan them to you... provided that the -connection between you and him is fast enough to carry all the traffic -between your machines and the rest of the Internet. In effect, he "extrudes" -a part of his address space over the network to you, with your Internet -traffic appearing to originate from behind his Internet gateway.</p> - -<p>As far as the Internet is concerned, your new extruded net is behind your -buddy's gateway. You route all your packets for the Internet at large -out his gateway, and receive return packets the same way. You route your -local packets locally.</p> - -<p>Suppose your friend has a.b.c.0/24 and wants to give you a.b.c.240/28. The -initial situation is:</p> -<pre> subnet gateway Internet - a.b.c.0/24 a.b.c.1 p.q.r.s</pre> -where anything from the Internet destined for any machine in a.b.c.0/24 is -routed via p.q.r.s and that gateway knows what to do from there. - -<p>Of course it is quite normal for various smaller subnets to exist behind -your friend's gateway. For example, your friend's company might have -a.b.c.16/28=development, a.b.c.32/28=marketing and so on. The Internet -neither knows not cares about this; it just delivers packets to the p.q.r.s -and lets the gateway do whatever needs to be done from there.</p> - -<p>What we want to do is take a subnet, perhaps a.b.c.240/28, out of your -friend's physical location <em>while still having your friend's gateway route -to it</em>. As far as the Internet is concerned, you remain behind that -gateway.</p> -<pre> subnet gateway Internet your gate extruded - - a.b.c.0/24 a.b.c.1 p.q.r.s d.e.f.g a.b.c.240/28 - - ========== tunnel ==========</pre> - -<p>The extruded addresses have to be a complete subnet.</p> - -<p>In our example, the friend's security gateway is also his Internet -gateway, but this is not necessary. As long as all traffic from the Internet -to his addresses passes through the Internet gate, the security gate could be -a machine behind that. The IG would need to route all traffic for the -extruded subnet to the SG, and the SG could handle the rest.</p> - -<p>First, configure your subnet using the extruded addresses. Your security -gateway's interface to your subnet needs to have an extruded address -(possibly using a Linux <a href="glossary.html#virtual">virtual -interface</a>, if it also has to have a different address). Your gateway -needs to have a route to the extruded subnet, pointing to that interface. The -other machines at your site need to have addresses in that subnet, and -default routes pointing to your gateway.</p> - -<p>If any of your friend's machines need to talk to the extruded subnet, -<em>they</em> need to have a route for the extruded subnet, pointing at his -gateway.</p> - -<p>Then set up an IPsec subnet-to-subnet tunnel between your gateway and his, -with your subnet specified as the extruded subnet, and his subnet specified -as "0.0.0.0/0".</p> - -<p>The tunnel description should be:</p> -<pre>conn extruded - left=p.q.r.s - leftsubnet=0.0.0.0/0 - right=d.e.f.g - rightsubnet=a.b.c.0/28</pre> - -<p>If either side was doing firewalling for the extruded subnet before the -IPsec connection is set up, you'll need to poke holes in your -<A HREF="firewall.html#firewall">firewall</A> to allow packets through. -</p> - -<p>And it all just works. Your SG routes traffic for 0.0.0.0/0 -- that is, -the whole Internet -- through the tunnel to his SG, which then sends it -onward as if it came from his subnet. When traffic for the extruded subnet -arrives at his SG, it gets sent through the tunnel to your SG, which passes -it to the right machine.</p> - -<p>Remember that when ipsec_manual or ipsec_auto takes a connection down, it -<em>does not undo the route</em> it made for that connection. This lets you -take a connection down and bring up a new one, or a modified version of the -old one, without having to rebuild the route it uses and without any risk of -packets which should use IPsec accidentally going out in the clear. Because -the route always points into KLIPS, the packets will always go there. Because -KLIPS temporarily has no idea what to do with them (no eroute for them), they -will be discarded.</p> - -<p>If you <em>do</em> want to take the route down, this is what the "unroute" -operation in manual and auto is for. Just do an unroute after doing the -down.</p> - -<p>Note that the route for a connection may have replaced an existing -non-IPsec route. Nothing in Linux FreeS/WAN will put that pre-IPsec route -back. If you need it back, you have to create it with the route command.</p> - -<h2><a name="roadvirt">Road Warrior with virtual IP address</a></h2> - -<p>Please note that <A HREF="http://www.freeswan.ca/download.php">Super -FreeS/WAN</A> now features DHCP-over-IPsec, which is an alternate procedure -for Virtual IP address assignment. -<p> - -<p>Here is a mailing list message about another way to configure for road -warrior support:</p> -<pre>Subject: Re: linux-ipsec: understanding the vpn - Date: Thu, 28 Oct 1999 10:43:22 -0400 - From: Irving Reid <irving@nevex.com> - -> local-------linux------internet------mobile -> LAN box user -> ... - -> now when the mobile user connects to the linux box -> it is given a virtual IP address, i have configured it to -> be in the 10.x.x.x range. mobile user and linux box -> have a tunnel between them with these IP addresses. - -> Uptil this all is fine. - -If it is possible to configure your mobile client software *not* to -use a virtual IP address, that will make your life easier. It is easier -to configure FreeS/WAN to use the actual address the mobile user gets -from its ISP. - -Unfortunately, some Windows clients don't let you choose. - -> what i would like to know is that how does the mobile -> user communicate with other computers on the local -> LAN , of course with the vpn ? - -> what IP address should the local LAN -> computers have ? I guess their default gateway -> should be the linux box ? and does the linux box need -> to be a 2 NIC card box or one is fine. - -As someone else stated, yes, the Linux box would usually be the default -IP gateway for the local lan. - -However... - -If you mobile user has software that *must* use a virtual IP address, -the whole picture changes. Nobody has put much effort into getting -FreeS/WAN to play well in this environment, but here's a sketch of one -approach: - -Local Lan 1.0.0.0/24 - | - +- Linux FreeS/WAN 1.0.0.2 - | - | 1.0.0.1 - Router - | 2.0.0.1 - | -Internet - | - | 3.0.0.1 -Mobile User - Virtual Address: 1.0.0.3 - -Note that the Local Lan network (1.0.0.x) can be registered, routable -addresses. - -Now, the Mobile User sets up an IPSec security association with the -Linux box (1.0.0.2); it should ESP encapsulate all traffic to the -network 1.0.0.x **EXCEPT** UDP port 500. 500/udp is required for the key -negotiation, which needs to work outside of the IPSec tunnel. - -On the Linux side, there's a bunch of stuff you need to do by hand (for -now). FreeS/WAN should correctly handle setting up the IPSec SA and -routes, but I haven't tested it so this may not work... - -The FreeS/WAN conn should look like: - -conn mobile - right=1.0.0.2 - rightsubnet=1.0.0.0/24 - rightnexthop=1.0.0.1 - left=0.0.0.0 # The infamous "road warrior" - leftsubnet=1.0.0.3/32 - -Note that the left subnet contains *only* the remote host's virtual -address. - -Hopefully the routing table on the FreeS/WAN box ends up looking like -this: - -% netstat -rn -Kernel IP routing table -Destination Gateway Genmask Flags MSS Window irtt Iface -1.0.0.0 0.0.0.0 255.255.255.0 U 1500 0 0 eth0 -127.0.0.0 0.0.0.0 255.0.0.0 U 3584 0 0 lo -0.0.0.0 1.0.0.1 0.0.0.0 UG 1500 0 0 eth0 -1.0.0.3 1.0.0.1 255.255.255.255 UG 1433 0 0 ipsec0 - -So, if anybody sends a packet for 1.0.0.3 to the Linux box, it should -get bundled up and sent through the tunnel. To get the packets for -1.0.0.3 to the Linux box in the first place, you need to use "proxy -ARP". - -How this works is: when a host or router on the local Ethernet segment -wants to send a packet to 1.0.0.3, it sends out an Ethernet level -broadcast "ARP request". If 1.0.0.3 was on the local LAN, it would -reply, saying "send IP packets for 1.0.0.3 to my Ethernet address". - -Instead, you need to set up the Linux box so that _it_ answers ARP -requests for 1.0.0.3, even though that isn't its IP address. That -convinces everyone else on the lan to send 1.0.0.3 packets to the Linux -box, where the usual FreeS/WAN processing and routing take over. - -% arp -i eth0 -s 1.0.0.3 -D eth0 pub - -This says, if you see an ARP request on interface eth0 asking for -1.0.0.3, respond with the Ethernet address of interface eth0. - -Now, as I said at the very beginning, if it is *at all* possible to -configure your client *not* to use the virtual IP address, you can avoid -this whole mess.</pre> - -<h2><a name="dynamic">Dynamic Network Interfaces</a></h2> - -<p>Sometimes you have to cope with a situation where the network interface(s) -aren't all there at boot. The common example is notebooks with PCMCIA.</p> - -<h3><a name="basicdyn">Basics</a></h3> - -<p>The key issue here is that the <var>config setup</var> section of the -<var>/etc/ipsec.conf</var> configuration file lists the connection between -ipsecN and hardware interfaces, in the <var>interfaces=</var> variable. At -any time when <var>ipsec setup start</var> or <var>ipsec setup restart</var> -is run this variable <strong>must</strong> correspond to the current real -situation. More precisely, it <strong>must not</strong> mention any hardware -interfaces which don't currently exist. The difficulty is that an <var>ipsec -setup start</var> command is normally run at boot time so interfaces that are -not up then are mis-handled.</p> - -<h3><a name="bootdyn">Boot Time</a></h3> - -<p>Normally, an <var>ipsec setup start</var> is run at boot time. However, if -the hardware situation at boot time is uncertain, one of two things must be -done.</p> -<ul> - <li>One possibility is simply not to have IPsec brought up at boot time. To - do this: - <pre> chkconfig --level 2345 ipsec off</pre> - That's for modern Red Hats or other Linuxes with chkconfig. Systems which - lack this will require fiddling with symlinks in /etc/rc.d/rc?.d or the - equivalent.</li> - <li>Another possibility is to bring IPsec up with no interfaces, which is - less aesthetically satisfying but simpler. Just put - <pre> interfaces=</pre> - in the configuration file. KLIPS and Pluto will be started, but won't do - anything.</li> -</ul> - -<h3><a name="changedyn">Change Time</a></h3> - -<p>When the hardware *is* in place, IPsec has to be made aware of it. Someday -there may be a nice way to do this.</p> - -<p>Right now, the way to do it is to fix the <var>/etc/ipsec.conf</var> file -appropriately, so <var>interfaces</var> reflects the new situation, and then -restart the IPsec subsystem. This does break any existing IPsec -connections.</p> - -<p>If IPsec wasn't brought up at boot time, do</p> -<pre> ipsec setup start</pre> -while if it was, do -<pre> ipsec setup restart</pre> -which won't be as quick. - -<p>If some of the hardware is to be taken out, before doing that, amend the -configuration file so interfaces no longer includes it, and do</p> -<pre> ipsec setup restart</pre> - -<p>Again, this breaks any existing connections.</p> - -<h2><a name="unencrypted">Unencrypted tunnels</a></h2> - -<p>Sometimes you might want to create a tunnel without encryption. Often this -is a bad idea, even if you have some data which need not be private. See this -<a href="ipsec.html#traffic.resist">discussion</a>.</p> - -<p>The IPsec protocols provide two ways to do build such tunnels:</p> -<dl> - <dt>using ESP with null encryption</dt> - <dd>not supported by FreeS/WAN</dd> - <dt>using <a href="glossary.html#AH">AH</a> without <a - href="glossary.html#ESP">ESP</a></dt> - <dd>supported for manually keyed connections</dd> - <dd>possible with explicit commands via <a - href="manpage.d/ipsec_whack.8.html">ipsec_whack(8)</a> (see this <a - href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00190.html">list - message</a>)</dd> - <dd>not supported in the <a - href="manpage.d/ipsec_auto.8.html">ipsec_auto(8)</a> scripts.</dd> -</dl> -One situation in which this comes up is when otherwise some data would be -encrypted twice. Alice wants a secure tunnel from her machine to Bob's. Since -she's behind one security gateway and he's behind another, part of the tunnel -that they build passes through the tunnel that their site admins have built -between the gateways. All of Alice and Bob's messages are encrypted twice. - -<p>There are several ways to handle this.</p> -<ul> - <li>Just accept the overhead of double encryption. The site admins might - choose this if any of the following apply: - <ul> - <li>policy says encrypt everything (usually, it should)</li> - <li>they don't entirely trust Alice and Bob (usually, if they don't - have to, they shouldn't)</li> - <li>if they don't feel the saved cycles are worth the time they'd need - to build a non-encrypted tunnel for Alice and Bob's packets (often, - they aren't)</li> - </ul> - </li> - <li>Use a plain IP-in-IP tunnel. These are not well documented. A good - starting point is in the Linux kernel source tree, in - /usr/src/linux/drivers/net/README.tunnel.</li> - <li>Use a manually-keyed AH-only tunnel.</li> -</ul> - -<p>Note that if Alice and Bob want end-to-end security, they must build a -tunnel end-to-end between their machines or use some other end-to-end tool -such as PGP or SSL that suits their data. The only question is whether the -admins build some special unencrypted tunnel for those already-encrypted -packets.</p> -</body> -</html> diff --git a/doc/src/background.html b/doc/src/background.html deleted file mode 100644 index e25b9da03..000000000 --- a/doc/src/background.html +++ /dev/null @@ -1,376 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>FreeS/WAN background</title> - <meta name="keywords" content="Linux, IPSEC, VPN, security, FreeSWAN"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: background.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1><a name="background">Linux FreeS/WAN background</a></h1> - -<p>This section discusses a number of issues which have three things in -common:</p> -<ul> - <li>They are not specifically FreeS/WAN problems</li> - <li>You may have to understand them to get FreeS/WAN working right</li> - <li>They are not simple questions</li> -</ul> - -<p>Grouping them here lets us provide the explanations some users will need -without unduly complicating the main text.</p> - -<p>The explanations here are intended to be adequate for FreeS/WAN purposes -(please comment to the <a href="mail.html">users mailing list</a> if you -don't find them so), but they are not trying to be complete or definitive. If -you need more information, see the references provided in each section.</p> - -<h2><a name="dns.background">Some DNS background</a></h2> - -<p><a href="glossary.html#carpediem">Opportunistic encryption</a> requires -that the gateway systems be able to fetch public keys, and other -IPsec-related information, from each other's DNS (Domain Name Service) -records.</p> - -<p><a href="glossary.html#DNS">DNS</a> is a distributed database that maps -names to IP addresses and vice versa.</p> - -<p>Much good reference material is available for DNS, including:</p> -<ul> - <li>the <a href="http://www.linuxdoc.org/HOWTO/DNS-HOWTO.html">DNS - HowTo</a></li> - <li>the standard <a href="biblio.html#DNS.book">DNS reference</a> book</li> - <li><a href="http://www.linuxdoc.org/LDP/nag2/index.html">Linux Network - Administrator's Guide</a></li> - <li><a - href="http://www.nominum.com/resources/whitepapers/bind-white-paper.html">BIND - overview</a></li> - <li><a - href="http://www.nominum.com/resources/documentation/Bv9ARM.pdf">BIND 9 - Administrator's Reference</a></li> -</ul> - -<p>We give only a brief overview here, intended to help you use DNS for -FreeS/WAN purposes.</p> - -<h3><a name="forward.reverse">Forward and reverse maps</a></h3> - -<p>Although the implementation is distributed, it is often useful to speak of -DNS as if it were just two enormous tables:</p> -<ul> - <li>the forward map: look up a name, get an IP address</li> - <li>the reverse map: look up an IP address, get a name</li> -</ul> - -<p>Both maps can optionally contain additional data. For opportunistic -encryption, we insert the data need for IPsec authentication.</p> - -<p>A system named gateway.example.com with IP address 10.20.30.40 should have -at least two DNS records, one in each map:</p> -<dl> - <dt>gateway.example.com. IN A 10.20.30.40</dt> - <dd>used to look up the name and get an IP address</dd> - <dt>40.30.20.10.in-addr.arpa. IN PTR gateway.example.com.</dt> - <dd>used for reverse lookups, looking up an address to get the associated - name. Notice that the digits here are in reverse order; the actual - address is 10.20.30.40 but we use 40.30.20.10 here.</dd> -</dl> - -<h3>Hierarchy and delegation</h3> - -<p>For both maps there is a hierarchy of DNS servers and a system of -delegating authority so that, for example:</p> -<ul> - <li>the DNS administrator for example.com can create entries of the form - <var>name</var>.example.com</li> - <li>the example.com admin cannot create an entry for counterexample.com; - only someone with authority for .com can do that</li> - <li>an admin might have authority for 20.10.in-addr.arpa.</li> - <li>in either map, authority can be delegated - <ul> - <li>the example.com admin could give you authority for - westcoast.example.com</li> - <li>the 20.10.in-addr.arpa admin could give you authority for - 30.20.10.in-addr.arpa</li> - </ul> - </li> -</ul> - -<p>DNS zones are the units of delegation. There is a hierarchy of zones.</p> - -<h3>Syntax of DNS records</h3> - -<p>Returning to the example records:</p> -<pre> gateway.example.com. IN A 10.20.30.40 - 40.30.20.10.in-addr.arpa. IN PTR gateway.example.com.</pre> - -<p>some syntactic details are:</p> -<ul> - <li>the IN indicates that these records are for <strong>In</strong>ternet - addresses</li> - <li>The final periods in '.com.' and '.arpa.' are required. They indicate - the root of the domain name system.</li> -</ul> - -<p>The capitalised strings after IN indicate the type of record. Possible -types include:</p> -<ul> - <li><strong>A</strong>ddress, for forward lookups</li> - <li><strong>P</strong>oin<strong>T</strong>e<strong>R</strong>, for reverse - lookups</li> - <li><strong>C</strong>anonical <strong>NAME</strong>, records to support - aliasing, multiple names for one address</li> - <li><strong>M</strong>ail e<strong>X</strong>change, used in mail - routing</li> - <li><strong>SIG</strong>nature, used in <a href="glossary.html#SDNS">secure - DNS</a></li> - <li><strong>KEY</strong>, used in <a href="glossary.html#SDNS">secure - DNS</a></li> - <li><strong>T</strong>e<strong>XT</strong>, a multi-purpose record type</li> -</ul> - -<p>To set up for opportunistic encryption, you add some TXT records -to your DNS data. Details are in our <a href="quickstart.html">quickstart</a> -document.</p> - -<h3>Cacheing, TTL and propagation delay</h3> - -<p>DNS information is extensively cached. With no caching, a lookup by your -system of "www.freeswan.org" might involve:</p> -<ul> - <li>your system asks your nameserver for "www.freeswan.org"</li> - <li>local nameserver asks root server about ".org", gets reply</li> - <li>local nameserver asks .org nameserver about "freeswan.org", gets - reply</li> - <li>local nameserver asks freeswan.org nameserver about "www.freeswan.org", - gets reply</li> -</ul> - -<p>However, this can be a bit inefficient. For example, if you are in the -Phillipines, the closest a root server is in Japan. That might send you to a -.org server in the US, and then to freeswan.org in Holland. If everyone did -all those lookups every time they clicked on a web link, the net would grind -to a halt.</p> - -<p>Nameservers therefore cache information they look up. When you click on -another link at www.freeswan.org, your local nameserver has the IP address -for that server in its cache, and no further lookups are required. </p> - -<p>Intermediate results are also cached. If you next go to -lists.freeswan.org, your nameserver can just ask the freeswan.org nameserver -for that address; it does not need to query the root or .org nameservers -because it has a cached address for the freeswan.org zone server.</p> - -<p>Of course, like any cacheing mechanism, this can create problems of -consistency. What if the administrator for freeswan.org changes the IP -address, or the authentication key, for www.freeswan.org? If you use old -information from the cache, you may get it wrong. On the other hand, you -cannot afford to look up fresh information every time. Nor can you expect the -freeswan.org server to notify you; that isn't in the protocols.</p> - -<p>The solution that is in the protocols is fairly simple. Cacheable records -are marked with Time To Live (TTL) information. When the time expires, the -caching server discards the record. The next time someone asks for it, the -server fetches a fresh copy. Of course, a server may also discard records -before their TTL expires if it is running out of cache space.</p> - -<p>This implies that there will be some delay before the new version of a -changed record propagates around the net. Until the TTLs on all copies of the -old record expire, some users will see it because that is what is in their -cache. Other users may see the new record immediately because they don't have -an old one cached.</p> - -<h2><a name="MTU.trouble">Problems with packet fragmentation</a></h2> - -<p>It seems, from mailing list reports, to be moderately common for problems -to crop up in which small packets pass through the IPsec tunnels just fine -but larger packets fail.</p> - -<p>These problems are caused by various devices along the way mis-handling -either packet fragments or <a href="glossary.html#pathMTU">path MTU -discovery</a>.</p> - -<p>IPsec makes packets larger by adding an ESP or AH header. This can tickle -assorted bugs in fragment handling in routers and firewalls, or in path MTU -discovery mechanisms, and cause a variety of symptoms which are both annoying -and, often, quite hard to diagnose.</p> - -<p>An explanation from project technical lead Henry Spencer:</p> -<pre>The problem is IP fragmentation; more precisely, the problem is that the -second, third, etc. fragments of an IP packet are often difficult for -filtering mechanisms to classify. - -Routers cannot rely on reassembling the packet, or remembering what was in -earlier fragments, because the fragments may be out of order or may even -follow different routes. So any general, worst-case filtering decision -pretty much has to be made on each fragment independently. (If the router -knows that it is the only route to the destination, so all fragments -*must* pass through it, reassembly would be possible... but most routers -don't want to bother with the complications of that.) - -All fragments carry roughly the original IP header, but any higher-level -header is (for IP purposes) just the first part of the packet data... so -only the first fragment carries that. So, for example, on examining the -second fragment of a TCP packet, you could tell that it's TCP, but not -what port number it is destined for -- that information is in the TCP -header, which appears in the first fragment only. - -The result of this classification difficulty is that stupid routers and -over-paranoid firewalls may just throw fragments away. To get through -them, you must reduce your MTU enough that fragmentation will not occur. -(In some cases, they might be willing to attempt reassembly, but have very -limited resources to devote to it, meaning that packets must be small and -fragments few in number, leading to the same conclusion: smaller MTU.)</pre> - -<p>In addition to the problem Henry describes, you may also have trouble with -<a href="glossary.html#pathMTU">path MTU discovery</a>.</p> - -<p>By default, FreeS/WAN uses a large <a href="glossary.html#MTU">MTU</a> for -the ipsec device. This avoids some problems, but may complicate others. -Here's an explanation from Claudia:</p> -<pre>Here are a couple of pieces of background information. Apologies if you -have seen these already. An excerpt from one of my old posts: - - An MTU of 16260 on ipsec0 is usual. The IPSec device defaults to this - high MTU so that it does not fragment incoming packets before encryption - and encapsulation. If after IPSec processing packets are larger than 1500, - [ie. the mtu of eth0] then eth0 will fragment them. - - Adding IPSec headers adds a certain number of bytes to each packet. - The MTU of the IPSec interface refers to the maximum size of the packet - before the IPSec headers are added. In some cases, people find it helpful - to set ipsec0's MTU to 1500-(IPSec header size), which IIRC is about 1430. - - That way, the resulting encapsulated packets don't exceed 1500. On most - networks, packets less than 1500 will not need to be fragmented. - -and... (from Henry Spencer) - - The way it *ought* to work is that the MTU advertised by the ipsecN - interface should be that of the underlying hardware interface, less a - pinch for the extra headers needed. - - Unfortunately, in certain situations this breaks many applications. - There is a widespread implicit assumption that the smallest MTUs are - at the ends of paths, not in the middle, and another that MTUs are - never less than 1500. A lot of code is unprepared to handle paths - where there is an "interior minimum" in the MTU, especially when it's - less than 1500. So we advertise a big MTU and just let the resulting - big packets fragment. - -This usually works, but we do get bitten in cases where some intermediate -point can't handle all that fragmentation. We can't win on this one.</pre> - -<p>The MTU can be changed with an <var>overridemtu=</var> statement in the -<var>config setup</var> section of <a -href="manpage.d/ipsec.conf.5.html">ipsec.conf.5</a>.</p> - -<p>For a discussion of MTU issues and some possible solutions using Linux -advanced routing facilities, see the <a -href="http://www.linuxguruz.org/iptables/howto/2.4routing-15.html#ss15.6">Linux -2.4 Advanced Routing HOWTO</a>. - -For a discussion of MTU and NAT (Network Address Translation), see -<A HREF="http://harlech.math.ucla.edu/services/ipsec.html">James Carter's MTU -notes</A>.</p> - -<h2><a name="nat.background">Network address translation (NAT)</a></h2> - -<p><strong>N</strong>etwork <strong>A</strong>ddress -<strong>T</strong>ranslation is a service provided by some gateway machines. -Calling it NAPT (adding the word <strong>P</strong>ort) would be more -precise, but we will follow the widespread usage.</p> - -<p>A gateway doing NAT rewrites the headers of packets it is forwarding, -changing one or more of:</p> -<ul> - <li>source address</li> - <li>source port</li> - <li>destination address</li> - <li>destination port</li> -</ul> - -<p>On Linux 2.4, NAT services are provided by the <a -href="http://netfilter.samba.org">netfilter(8)</a> firewall code. There are -several <a -href="http://netfilter.samba.org/documentation/index.html#HOWTO">Netfilter -HowTos</a> including one on NAT.</p> - -<p>For older versions of Linux, this was referred to as "IP masquerade" and -different tools were used. See this <a -href="http://www.e-infomax.com/ipmasq/">resource page</a>.</p> - -<p>Putting an IPsec gateway behind a NAT gateway is not recommended. See our -<a href="firewall.html#NAT">firewalls document</a>.</p> - -<h3>NAT to non-routable addresses</h3> - -<p>The most common application of NAT uses private <a -href="glossary.html#non-routable">non-routable</a> addresses.</p> - -<p>Often a home or small office network will have:</p> -<ul> - <li>one connection to the Internet</li> - <li>one assigned publicly visible IP address</li> - <li>several machines that all need access to the net</li> -</ul> - -<p>Of course this poses a problem since several machines cannot use one -address. The best solution might be to obtain more addresses, but often this -is impractical or uneconomical.</p> - -<p>A common solution is to have:</p> -<ul> - <li><a href="glossary.html#non-routable">non-routable</a> addresses on the - local network</li> - <li>the gateway machine doing NAT</li> - <li>all packets going outside the LAN rewritten to have the gateway as - their source address</li> -</ul> - -<p>The client machines are set up with reserved <a -href="#non-routable">non-routable</a> IP addresses defined in RFC 1918. The -masquerading gateway, the machine with the actual link to the Internet, -rewrites packet headers so that all packets going onto the Internet appear to -come from one IP address, that of its Internet interface. It then gets all -the replies, does some table lookups and more header rewriting, and delivers -the replies to the appropriate client machines.</p> - -<p>As far as anyone else on the Internet is concerned, the systems behind the -gateway are completely hidden. Only one machine with one IP address is -visible.</p> - -<p>For IPsec on such a gateway, you can entirely ignore the NAT in:</p> -<ul> - <li><a href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a></li> - <li>firewall rules affecting your Internet-side interface</li> -</ul> - -<p>Those can be set up exactly as they would be if your gateway had no other -systems behind it.</p> - -<p>You do, however, have to take account of the NAT in firewall rules which -affect packet forwarding.</p> - -<h3>NAT to routable addresses</h3> - -<p>NAT to routable addresses is also possible, but is less common and may -make for rather tricky routing problems. We will not discuss it here. See the -<a href="http://netfilter.samba.org/documentation/index.html#HOWTO">Netfilter -HowTos</a>.</p> -</body> -</html> diff --git a/doc/src/biblio.html b/doc/src/biblio.html deleted file mode 100644 index d84e4c2cb..000000000 --- a/doc/src/biblio.html +++ /dev/null @@ -1,354 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>FreeS/WAN bibliography</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, bibliography"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: biblio.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1><a name="biblio">Bibliography for the Linux FreeS/WAN project</a></h1> - -<p>For extensive bibliographic links, see the <a -href="http://liinwww.ira.uka.de/bibliography/index.html">Collection of -Computer Science Bibliographies</a></p> - -<p>See our <a href="web.html">web links</a> for material available online.</p> -<hr> -<a name="adams">Carlisle Adams and Steve Lloyd <cite>Understanding Public Key -Infrastructure</cite><br> -</a>Macmillan 1999 ISBN 1-57870-166-x - -<p>An overview, mainly concentrating on policy and strategic issues rather -than the technical details. Both authors work for <a -href="glossary.html#PKI">PKI</a> vendor <a -href="http://www.entrust.com/">Entrust</a>.</p> -<hr> -<a name="DNS.book">Albitz, Liu & Loukides <cite>DNS & BIND</cite> 3rd -edition<br> -</a> O'Reilly 1998 ISBN 1-56592-512-2 - -<p>The standard reference on the <a href="glossary.html#DNS">Domain Name -Service</a> and <a href="glossary.html#BIND">Berkeley Internet Name -Daemon</a>.</p> -<hr> -<a name="anderson">Ross Anderson</a>, <cite>Security Engineering - a Guide to -Building Dependable Distributed Systems</cite><br> -Wiley, 2001, ISBN 0471389226 - -<p>Easily the best book for the security professional I have seen. -<strong>Highly recommended</strong>. See the <a -href="http://www.cl.cam.ac.uk/~rja14/book.html">book web page</a>.</p> - -<p>This is quite readable, but Schneier's <a href="#secrets">Secrets and -Lies</a> might be an easier introduction.</p> -<hr> -<a name="puzzle">Bamford <cite>The Puzzle Palace, A report on NSA, Americas's -most Secret Agency</cite><br> -Houghton Mifflin 1982 ISBN 0-395-31286-8</a> -<hr> -Bamford <cite>Body of Secrets</cite> - -<p>The sequel.</p> -<hr> -<a name="bander">David Bander</a>, <cite>Linux Security Toolkit</cite><br> -IDG Books, 2000, ISBN: 0764546902 - -<p>This book has a short section on FreeS/WAN and includes Caldera Linux on -CD.</p> -<hr> -<a name="CZR">Chapman, Zwicky & Russell</a>, <cite>Building Internet -Firewalls</cite><br> -O'Reilly 1995 ISBN 1-56592-124-0 -<hr> -<a name="firewall.book">Cheswick and Bellovin</a> <cite>Firewalls and -Internet Security: Repelling the Wily Hacker</cite><br> -Addison-Wesley 1994 ISBN 0201633574 - -<p>A fine book on firewalls in particular and security in general from two of -AT&T's system adminstrators.</p> - -<p>Bellovin has also done a number of <a href="web.html#papers">papers</a> on -IPsec and co-authored a <a href="intro.html#applied">paper</a> on a large -FreeS/WAN application.</p> -<hr> -<a name="comer">Comer <cite>Internetworking with TCP/IP</cite><br> -Prentice Hall</a> -<ul> - <li>Vol. I: Principles, Protocols, & Architecture, 3rd Ed. 1995 - ISBN:0-13-216987-8</li> - <li>Vol. II: Design, Implementation, & Internals, 2nd Ed. 1994 - ISBN:0-13-125527-4</li> - <li>Vol. III: Client/Server Programming & Applications - <ul> - <li>AT&T TLI Version 1994 ISBN:0-13-474230-3</li> - <li>BSD Socket Version 1996 ISBN:0-13-260969-X</li> - <li>Windows Sockets Version 1997 ISBN:0-13-848714-6</li> - </ul> - </li> -</ul> - -<p>If you need to deal with the details of the network protocols, read either -this series or the <a href="#stevens">Stevens and Wright</a> series before -you start reading the RFCs.</p> -<hr> -<a name="diffie">Diffie and Landau</a> <cite>Privacy on the Line: The -Politics of Wiretapping and Encryption</cite><br> -MIT press 1998 ISBN 0-262-04167-7 (hardcover) or 0-262-54100-9<br> - -<hr> -<a name="d_and_hark">Doraswamy and Harkins <cite>IP Sec: The New Security -Standard for the Internet, Intranets and Virtual Private Networks</cite><br> -Prentice Hall 1999 ISBN: 0130118982</a> -<hr> -<a name="EFF"> Electronic Frontier Foundation <cite>Cracking DES: Secrets of -Encryption Research, Wiretap Politics and Chip Design</cite><br> -</a> O'Reilly 1998 ISBN 1-56592-520-3 - -<p>To conclusively demonstrate that DES is inadequate for continued use, the -<a href="glossary.html#EFF">EFF</a> built a machine for just over $200,000 -that breaks DES encryption in under five days on average, under nine in the -worst case.</p> - -<p>The book provides details of their design and, perhaps even more -important, discusses why they felt the project was necessary. Recommended for -anyone interested in any of the three topics mentioned in the subtitle.</p> - -<p>See also the <a href="http://www.eff.org/descracker.html"> EFF page on -this project </a> and our discussion of <a -href="politics.html#desnotsecure">DES insecurity</a>.</p> -<hr> -Martin Freiss <cite>Protecting Networks with SATAN</cite><br> -O'Reilly 1998 ISBN 1-56592-425-8<br> -translated from a 1996 work in German - -<p>SATAN is a Security Administrator's Tool for Analysing Networks. This book -is a tutorial in its use.</p> -<hr> -Gaidosch and Kunzinger<cite> A Guide to Virtual Private Networks</cite><br> -Prentice Hall 1999 ISBN: 0130839647 -<hr> -<a name="Garfinkel">Simson Garfinkel</a> <cite>Database Nation: the death of -privacy in the 21st century</cite><br> -O'Reilly 2000 ISBN 1-56592-653-6 - -<p>A thoughtful and rather scary book.</p> -<hr> -<a name="PGP">Simson Garfinkel</a> <cite>PGP: Pretty Good Privacy</cite><br> -O'Reilly 1995 ISBN 1-56592-098-8 - -<p>An excellent introduction and user manual for the <a -href="glossary.html#PGP">PGP</a> email-encryption package. PGP is a good -package with a complex and poorly-designed user interface. This book or one -like it is a must for anyone who has to use it at length.</p> - -<p>The book covers using PGP in Unix, PC and Macintosh environments, plus -considerable background material on both the technical and political issues -around cryptography.</p> - -<p>The book is now seriously out of date. It does not cover recent -developments such as commercial versions since PGP 5, the Open PGP standard -or GNU PG..</p> -<hr> -<a name="practical">Garfinkel and Spafford</a> <cite>Practical Unix -Security</cite><br> -O'Reilly 1996 ISBN 1-56592-148-8 - -<p>A standard reference.</p> - -<p>Spafford's web page has an excellent collection of<a -href="http://www.cs.purdue.edu/coast/hotlist"> crypto and security -links</a>.</p> -<hr> -<a name="Kahn">David Kahn</a> <cite>The Codebreakers: the Comprehensive -History of Secret Communications from Ancient Times to the Internet</cite><br> -second edition Scribner 1996 ISBN 0684831309 - -<p>A history of codes and code-breaking from ancient Egypt to the 20th -century. Well-written and exhaustively researched. <strong>Highly -recommended</strong>, even though it does not have much on computer -cryptography.</p> -<hr> -David Kahn <cite>Seizing the Enigma, The Race to Break the German U-Boat -codes, 1939-1943</cite><br> -Houghton Mifflin 1991 ISBN 0-395-42739-8 -<hr> -<a name="kirch">Olaf Kirch</a> <cite>Linux Network Administrator's -Guide</cite><br> -O'Reilly 1995 ISBN 1-56592-087-2 - -<p>Now becoming somewhat dated in places, but still a good introductory book -and general reference.</p> -<hr> -<a name="LinVPN">Kolesnikov and Hatch</a>, <cite>Building Linux Virtual -Private Networks (VPNs)</cite><br> -New Riders 2002 - -<p>This has had a number of favorable reviews, including <a -href="http://www.slashdot.org/article.pl?sid=02/02/27/0115214&mode=thread&tid=172">this -one</a> on Slashdot. The book has a <a -href="http://www.buildinglinuxvpns.net/">web site</a>.</p> -<hr> -<a name="RFCs">Pete Loshin <cite>Big Book of IPsec RFCs</cite><br> -Morgan Kaufmann 2000 ISBN: 0-12-455839-9</a> -<hr> -<a name="crypto">Steven Levy <cite>Crypto: How the Code Rebels Beat the -Government -- Saving Privacy in the Digital Age</cite></a><br> -Penguin 2001, ISBN 0-670--85950-8 - -<p><strong>Highly recommended</strong>. A fine history of recent (about -1970-2000) developments in the field, and the related political -controversies. FreeS/WAN project founder and leader John Gilmore appears -several times.</p> - -<p>The book does not cover IPsec or FreeS/WAN, but this project is very much -another battle in the same war. See our discussion of the <a -href="politics.html">politics</a>.</p> -<hr> -<a name="GTR">Matyas, Anderson et al.</a> <cite>The Global Trust -Register</cite><br> -Northgate Consultants Ltd 1998 ISBN: 0953239705<br> -hard cover edition MIT Press 1999 ISBN 0262511053 - -<p>From<a href="http://www.cl.cam.ac.uk/Research/Security/Trust-Register"> -their web page:</a></p> - -<blockquote> - This book is a register of the fingerprints of the world's most important - public keys; it implements a top-level certification authority (CA) using - paper and ink rather than in an electronic system.</blockquote> -<hr> -<a name="handbook">Menezies, van Oorschot and Vanstone <cite>Handbook of -Applied Cryptography</cite></a><br> -CRC Press 1997<br> -ISBN 0-8493-8523-7 - -<p>An excellent reference. Read <a href="#schneier">Schneier</a> before -tackling this.</p> -<hr> -Michael Padlipsky <cite>Elements of Networking Style</cite><br> -Prentice-Hall 1985 ISBN 0-13-268111-0 or 0-13-268129-3 - -<p>Probably <strong>the funniest technical book ever written</strong>, this -is a vicious but well-reasoned attack on the OSI "seven layer model" and all -that went with it. Several chapters of it are also available as RFCs 871 to -875.</p> -<hr> -<a name="matrix">John S. Quarterman</a> <cite>The Matrix: Computer Networks -and Conferencing Systems Worldwide</cite><br> -Digital Press 1990 ISBN 155558-033-5<br> -Prentice-Hall ISBN 0-13-565607-9 - -<p>The best general treatment of computer-mediated communication we have -seen. It naturally has much to say about the Internet, but also covers UUCP, -Fidonet and so on.</p> -<hr> -<a name="ranch">David Ranch</a> <cite>Securing Linux Step by Step</cite><br> -SANS Institute, 1999 - -<p><a href="http://www.sans.org/">SANS</a> is a respected organisation, this -guide is part of a well-known series, and Ranch has previously written the -useful <a -href=" http://www.ecst.csuchico.edu/~dranch/LINUX/index-linux.html#trinityos">Trinity -OS</a> guide to securing Linux, so my guess would be this is a pretty good -book. I haven't read it yet, so I'm not certain. It can be ordered online -from <a href="http://www.sans.org/">SANS</a>.</p> - -<p>Note (Mar 1, 2002): a new edition with different editors in the works. -Expect it this year.</p> -<hr> -<a name="schneier">Bruce Schneier</a> <cite>Applied Cryptography, Second -Edition</cite><br> -John Wiley & Sons, 1996<br> -ISBN 0-471-12845-7 hardcover<br> -ISBN 0-471-11709-9 paperback - -<p>A standard reference on computer cryptography. For more recent essays, see -the <a href="http://www.counterpane.com/">author's company's web site</a>.</p> -<hr> -<a name="secrets">Bruce Schneier</a><cite> Secrets and Lies</cite><br> -Wiley 2000, ISBN 0-471-25311-1 - -<p>An interesting discussion of security and privacy issues, written with -more of an "executive overview" approach rather than a narrow focus on the -technical issues. <strong>Highly recommended</strong>.</p> - -<p>This is worth reading even if you already understand security issues, or -think you do. To go deeper, follow it with Anderson's <a -href="#anderson">Security Engineering</a>.</p> -<hr> -<a name="VPNbook">Scott, Wolfe and Irwin <cite>Virtual Private -Networks</cite></a><br> -2nd edition, O'Reilly 1999 ISBN: 1-56592-529-7 - -<p>This is the only O'Reilly book, out of a dozen I own, that I'm -disappointed with. It deals mainly with building VPNs with various -proprietary tools -- <a href="glossary.html#PPTP">PPTP</a>, <a -href="glossary.html#SSH">SSH</a>, Cisco PIX, ... -- and touches only lightly -on IPsec-based approaches.</p> - -<p>That said, it appears to deal competently with what it does cover and it -has readable explanations of many basic VPN and security concepts. It may be -exactly what some readers require, even if I find the emphasis -unfortunate.</p> -<hr> -<a name="LASG">Kurt Seifried <cite>Linux Administrator's Security -Guide</cite></a> - -<p>Available online from <a -href="http://www.securityportal.com/lasg/">Security Portal</a>. It has fairly -extensive coverage of IPsec.</p> -<hr> -<a name="Smith">Richard E Smith <cite>Internet Cryptography</cite><br> -</a>ISBN 0-201-92480-3, Addison Wesley, 1997 - -<p>See the book's <a -href="http://www.visi.com/crypto/inet-crypto/index.html">home page</a></p> -<hr> -<a name="neal">Neal Stephenson <cite>Cryptonomicon</cite></a><br> -Hardcover ISBN -380-97346-4, Avon, 1999. - -<p>A novel in which cryptography and the net figure prominently. -<strong>Highly recommended</strong>: I liked it enough I immediately went out -and bought all the author's other books.</p> - -<p>There is also a paperback edition. Sequels are expected.</p> -<hr> -<a name="stevens">Stevens and Wright</a> <cite>TCP/IP Illustrated</cite><br> -Addison-Wesley -<ul> - <li>Vol. I: The Protocols 1994 ISBN:0-201-63346-9</li> - <li>Vol. II: The Implementation 1995 ISBN:0-201-63354-X</li> - <li>Vol. III: TCP for Transactions, HTTP, NNTP, and the UNIX Domain - Protocols 1996 ISBN: 0-201-63495-3</li> -</ul> - -<p>If you need to deal with the details of the network protocols, read either -this series or the <a href="#comer">Comer</a> series before you start reading -the RFCs.</p> -<hr> -<a name="Rubini">Rubini</a> <cite>Linux Device Drivers</cite><br> -O'Reilly & Associates, Inc. 1998 ISBN 1-56592-292-1 -<hr> -<a name="Zeigler">Robert Zeigler</a> <cite>Linux Firewalls</cite><br> -Newriders Publishing, 2000 ISBN 0-7537-0900-9 - -<p>A good book, with detailed coverage of ipchains(8) firewalls and of many -related issues.</p> -</body> -</html> diff --git a/doc/src/buildtools.html b/doc/src/buildtools.html deleted file mode 100644 index c8cfa1fc8..000000000 --- a/doc/src/buildtools.html +++ /dev/null @@ -1,27 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> -<HTML> - <HEAD> - <TITLE>Tools used to build FreeSWAN releases (08-Mar-2002)</TITLE> - <!-- Created by: Michael Richardson, 08-Mar-2002 --> - - - </HEAD> - <BODY> - <H1>Tools used to build FreeSWAN releases</H1> - -<H2>man2html</H2> - -<P> -If you are not running RedHat, you will need man2html. This is part of the -"man" RPM on RedHat, whose sources can be found at <A HREF="ftp://ftp.win.tue.nl/pub/linux-local/utils/man/">ftp://ftp.win.tue.nl/pub/linux-local/utils/man/</A>. -</P> - -<P> -Note that the Debian package <A HREF="http://packages.debian.org/man2html">man2html</A> -and the one listed on Freshmeat at -<A HREF="http://freshmeat.net/projects/man2html/">man2html</A> will -not work. -</P> - - </BODY> -</HTML>
\ No newline at end of file diff --git a/doc/src/compat.html b/doc/src/compat.html deleted file mode 100644 index a8e1455bf..000000000 --- a/doc/src/compat.html +++ /dev/null @@ -1,795 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>FreeS/WAN compatibility guide</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, compatibility"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: compat.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1><a name="compat">Linux FreeS/WAN Compatibility Guide</a></h1> - -<p>Much of this document is quoted directly from the Linux FreeS/WAN <a -href="mail.html">mailing list</a>. Thanks very much to the community of -testers, patchers and commenters there, especially the ones quoted below but -also various contributors we haven't quoted.</p> - -<h2><a name="spec">Implemented parts of the IPsec Specification</a></h2> - -<p>In general, do not expect Linux FreeS/WAN to do everything yet. This is a -work-in-progress and some parts of the IPsec specification are not yet -implemented.</p> - -<h3><a name="in">In Linux FreeS/WAN</a></h3> - -<p>Things we do, as of version 1.96:</p> -<ul> - <li>key management methods - <dl> - <dt>manually keyed</dt> - <dd>using keys stored in /etc/ipsec.conf</dd> - <dt>automatically keyed</dt> - <dd>Automatically negotiating session keys as required. All - connections are automatically re-keyed periodically. The <a - href="glossary.html#Pluto">Pluto</a> daemon implements this using - the <a href="glossary.html#IKE">IKE</a> protocol.</dd> - </dl> - </li> - <li>Methods of authenticating gateways for IKE - <dl> - <dt>shared secrets</dt> - <dd>stored in <a - href="manpage.d/ipsec.secrets.5.html">ipsec.secrets(5)</a></dd> - <dt><a href="glossary.html#RSA">RSA</a> signatures</dt> - <dd>For details, see <a - href="manpage.d/ipsec_pluto.8.html">pluto(8)</a>.</dd> - <dt>looking up RSA authentication keys from <a - href="glossary.html#DNS">DNS</a>.</dt> - <dd>Note that this technique cannot be fully secure until <a - href="glossary.html#SDNS">secure DNS</a> is widely deployed.</dd> - </dl> - </li> - <li>groups for <a href="glossary.html#DH">Diffie-Hellman</a> key negotiation - <dl> - <dt>group 2, modp 1024-bit</dt> - <dt>group 5, modp 1536-bit</dt> - <dd>We implement these two groups. - <p>In negotiating a keying connection (ISAKMP SA, Phase 1) we - propose both groups when we are the initiator, and accept either - when a peer proposes them. Once the keying connection is made, we - propose only the alternative agreed there for data connections - (IPsec SA's, Phase 2) negotiated over that keying connection.</p> - </dd> - </dl> - </li> - <li>encryption transforms - <dl> - <dt><a href="glossary.html#DES">DES</a></dt> - <dd>DES is in the source code since it is needed to implement 3DES, - but single DES is not made available to users because <a - href="politics.html#desnotsecure">DES is insecure</a>.</dd> - <dt><a href="glossary.html#3DES">Triple DES</a></dt> - <dd>implemented, and used as the default encryption in Linux - FreeS/WAN.</dd> - </dl> - </li> - <li>authentication transforms - <dl> - <dt><a href="glossary.html#HMAC">HMAC</a> using <a - href="glossary.html#MD5">MD5</a></dt> - <dd>implemented, may be used in IKE or by by AH or ESP - transforms.</dd> - <dt><a href="glossary.html#HMAC">HMAC</a> using <a - href="glossary.html#SHA">SHA</a></dt> - <dd>implemented, may be used in IKE or by AH or ESP transforms.</dd> - </dl> - <p>In negotiations, we propose both of these and accept either.</p> - </li> - <li>compression transforms - <dl> - <dt>IPComp</dt> - <dd>IPComp as described in RFC 2393 was added for FreeS/WAN 1.6. Note - that Pluto becomes confused if you ask it to do IPComp when the - kernel cannot.</dd> - </dl> - </li> -</ul> - -<p>All combinations of implemented transforms are supported. Note that some -form of packet-level <strong>authentication is required whenever encryption -is used</strong>. Without it, the encryption will not be secure.</p> - -<h3><a name="dropped">Deliberately omitted</a></h3> -We do not implement everything in the RFCs because some of those things are -insecure. See our discussions of avoiding <a href="politics.html#weak">bogus -security</a>. - -<p>Things we deliberately omit which are required in the RFCs are:</p> -<ul> - <li>null encryption (to use ESP as an authentication-only service)</li> - <li>single DES</li> - <li>DH group 1, a 768-bit modp group</li> -</ul> - -<p>Since these are the only encryption algorithms and DH group the RFCs -require, it is possible in theory to have a standards-conforming -implementation which will not interpoperate with FreeS/WAN. Such an -implementation would be inherently insecure, so we do not consider this a -problem.</p> - -<p>Anyway, most implementations sensibly include more secure options as well, -so dropping null encryption, single DES and Group 1 does not greatly hinder -interoperation in practice.</p> - -<p>We also do not implement some optional features allowed by the RFCs:</p> -<ul> - <li>aggressive mode for negotiation of the keying channel or ISAKMP SA. - This mode is a little faster than main mode, but exposes more information - to an eavesdropper.</li> -</ul> - -<p>In theory, this should cause no interoperation problems since all -implementations are required to support the more secure main mode, whether or -not they also allow aggressive mode.</p> - -<p>In practice, it does sometimes produce problems with implementations such -as Windows 2000 where aggressive mode is the default. Typically, these are -easily solved with a configuration change that overrides that default.</p> - -<h3><a name="not">Not (yet) in Linux FreeS/WAN</a></h3> - -<p>Things we don't yet do, as of version 1.96:</p> -<ul> - <li>key management methods - <ul> - <li>authenticate key negotiations via local <a - href="glossary.html#PKI">PKI</a> server, but see links to user <a - href="web.html#patch">patches</a></li> - <li>authenticate key negotiations via <a - href="glossary.html#SDNS">secure DNS</a></li> - <li>unauthenticated key management, using <a - href="glossary.html#DH">Diffie-Hellman</a> key agreement protocol - without authentication. Arguably, this would be worth doing since it - is secure against all passive attacks. On the other hand, it is - vulnerable to an active <a - href="glossary.html#middle">man-in-the-middle attack</a>.</li> - </ul> - </li> - <li>encryption transforms - <p>Currently <a href="glossary.html#3DES">Triple DES</a> is the only - encryption method Pluto will negotiate.</p> - <p>No additional encryption transforms are implemented, though the RFCs - allow them and some other IPsec implementations support various of them. - We are not eager to add more. See this <a - href="faq.html#other.cipher">FAQ question</a>.</p> - <p><a href="glossary.html#AES">AES</a>, the successor to the DES - standard, is an excellent candidate for inclusion in FreeS/WAN, see links - to user <a href="web.html#patch">patches</a>.</p> - </li> - <li>authentication transforms - <p>No optional additional authentication transforms are currently - implemented. Likely <a href="glossary.html#SHA-256">SHA-256, SHA-384 and - SHA-512</a> will be added when AES is.</p> - </li> - <li>Policy checking on decrypted packets - <p>To fully comply with the RFCs, it is not enough just to accept only - packets which survive any firewall rules in place to limit what IPsec - packets get in, and then pass KLIPS authentication. That is what - FreeS/WAN currently does.</p> - <p>We should also apply additional tests, for example ensuring that all - packets emerging from a particular tunnel have source and destination - addresses that fall within the subnets defined for that tunnel, and that - packets with those addresses that did not emerge from the appropriate - tunnel are disallowed.</p> - <p>This will be done as part of a KLIPS rewrite. See these <a - href="intro.html#applied">links</a> and the <a href="mail.html">design - mailing list</a> for discussion.</p> - </li> -</ul> - -<h2><a name="pfkey">Our PF-Key implementation</a></h2> - -<p>We use PF-key Version Two for communication between the KLIPS kernel code -and the Pluto Daemon. PF-Key v2 is defined by <a -href="http://www.normos.org/ietf/rfc/rfc2367.txt">RFC 2367</a>.</p> - -<p>The "PF" stands for Protocol Family. PF-Inet defines a kernel/userspace -interface for the TCP/IP Internet protocols (TCP/IP), and other members of -the PF series handle Netware, Appletalk, etc. PF-Key is just a PF for -key-related matters.</p> - -<h3><a name="pfk.port">PF-Key portability</a></h3> - -<p>PF-Key came out of Berkeley Unix work and is used in the various BSD IPsec -implementations, and in Solaris. This means there is some hope of porting our -Pluto(8) to one of the BSD distributions, or of running their photurisd(8) on -Linux if you prefer <a href="glossary.html#photuris">Photuris</a> key -management over IKE.</p> - -<p>It is, however, more complex than that. The PK-Key RFC deliberately deals -only with keying, not policy management. The three PF-Key implementations we -have looked at -- ours, OpenBSD and KAME -- all have extensions to deal with -security policy, and the extensions are different. There have been -discussions aimed at sorting out the differences, perhaps for a version three -PF-Key spec. All players are in favour of this, but everyone involved is busy -and it is not clear whether or when these discussions might bear fruit.</p> - -<h2><a name="otherk">Kernels other than the latest 2.2.x and 2.4.y</a></h2> - -<p>We develop and test on Redhat Linux using the most recent kernel in the -2.2 and 2.4 series. In general, we recommend you use the latest kernel in one -of those series. Complications and caveats are discussed below.</p> - -<h3><a name="kernel.2.0">2.0.x kernels</a></h3> - -<p>Consider upgrading to the 2.2 kernel series. If you want to stay with the -2.0 series, then we strongly recommend 2.0.39. Some useful security patches -were added in 2.0.38.</p> - -<p>Various versions of the code have run at various times on most 2.0.xx -kernels, but the current version is only lightly tested on 2.0.39, and not at -all on older kernels.</p> - -<p>Some of our patches for older kernels are shipped in 2.0.37 and later, so -they are no longer provided in FreeS/WAN. This means recent versions of -FreeS/WAN will probably not compile on anything earlier than 2.0.37.</p> - -<h3><a name="kernel.production">2.2 and 2.4 kernels</a></h3> -<dl> - <dt>FreeS/WAN 1.0</dt> - <dd>ran only on 2.0 kernels</dd> - <dt>FreeS/WAN 1.1 to 1.8</dt> - <dd>ran on 2.0 or 2.2 kernels<br> - ran on some development kernels, 2.3 or 2.4-test</dd> - <dt>FreeS/WAN 1.9 to 1.96</dt> - <dd>runs on 2.0, 2.2 or 2.4 kernels</dd> -</dl> - -<p>In general, <strong>we suggest the latest 2.2 kernel or 2.4 for production -use</strong>.</p> - -<p>Of course no release can be guaranteed to run on kernels more recent than -it is, so quite often there will be no stable FreeS/WAN for the absolute -latest kernel. See the <a href="faq.html#k.versions">FAQ</a> for -discussion.</p> - -<h2><a name="otherdist">Intel Linux distributions other than Redhat</a></h2> - -<p>We develop and test on Redhat 6.1 for 2.2 kernels, and on Redhat 7.1 or -7.2 for 2.4, so minor changes may be required for other distributions.</p> - -<h3><a name="rh7">Redhat 7.0</a></h3> - -<p>There are some problems with FreeS/WAN on Redhat 7.0. They are soluble, -but we recommend you upgrade to a later Redhat instead..</p> - -<p>Redhat 7 ships with two compilers.</p> -<ul> - <li>Their <var>gcc</var> is version 2.96. Various people, including the GNU - compiler developers and Linus, have said fairly emphatically that using - this was a mistake. 2.96 is a development version, not intended for - production use. In particular, it will not compile a Linux kernel.</li> - <li>Redhat therefore also ship a separate compiler, which they call - <var>kgcc</var>, for compiling kernels.</li> -</ul> - -<p>Kernel Makefiles have <var>gcc</var> as a default, and must be adjusted to -use <var>kgcc</var> before a kernel will compile on 7.0. This mailing list -message gives details:</p> -<pre>Subject: Re: AW: Installing IPsec on Redhat 7.0 - Date: Thu, 1 Feb 2001 14:32:52 -0200 (BRST) - From: Mads Rasmussen <mads@cit.com.br> - -> From www.redhat.com/support/docs/gotchas/7.0/gotchas-7-6.html#ss6.1 - -cd to /usr/src/linux and open the Makefile in your favorite editor. You -will need to look for a line similar to this: - -CC = $(CROSS_COMPILE)gcc -D__KERNEL__ -I$(HPATH) - -This line specifies which C compiler to use to build the kernel. It should -be changed to: - -CC = $(CROSS_COMPILE)kgcc -D__KERNEL__ -I$(HPATH) - -for Red Hat Linux 7. The kgcc compiler is egcs 2.91.66. From here you can -proceed with the typical compiling steps.</pre> - -<p>Check the <a href="mail.html">mailing list</a> archive for more recent -news.</p> - -<h3><a name="suse">SuSE Linux</a></h3> - -<p>SuSE 6.3 and later versions, at least in Europe, ship with FreeS/WAN -included.</p> - -<P>FreeS/WAN packages distributed for SuSE 7.0-7.2 were somehow -miscompiled. You can find fixed packages on -<A HREF="http://www.suse.de/~garloff/linux/FreeSWAN"> -Kurt Garloff's page</A>.</P> - -<p>Here are some notes for an earlier SuSE version.</p> - -<h4>SuSE Linux 5.3</h4> -<pre>Date: Mon, 30 Nov 1998 -From: Peter Onion <ponion@srd.bt.co.uk> - -... I got Saturdays snapshot working between my two SUSE5.3 machines at home. - -The mods to the install process are quite simple. From memory and looking at -the files on the SUSE53 machine here at work.... - -And extra link in each of the /etc/init.d/rc?.d directories called K35ipsec -which SUSE use to shut a service down. - -A few mods in /etc/init.d/ipsec to cope with the different places that SUSE -put config info, and remove the inculsion of /etc/rc.d/init.d/functions and . -/etc/sysconfig/network as they don't exists and 1st one isn't needed anyway. - -insert ". /etc/rc.config" to pick up the SUSE config info and use - - if test -n "$NETCONFIG" -a "$NETCONFIG" != "YAST_ASK" ; then - -to replace - - [ ${NETWORKING} = "no" ] && exit 0 - -Create /etc/sysconfig as SUSE doesn't have one. - -I think that was all (but I prob forgot something)....</pre> - -<p>You may also need to fiddle initialisation scripts to ensure that -<var>/var/run/pluto.pid</var> is removed when rebooting. If this file is -present, Pluto does not come up correctly.</p> - -<h3><a name="slack">Slackware</a></h3> -<pre>Subject: Re: linux-IPsec: Slackware distribution - Date: Thu, 15 Apr 1999 12:07:01 -0700 - From: Evan Brewer <dmessiah@silcon.com> - -> Very shortly, I will be needing to install IPsec on at least gateways that -> are running Slackware. . . . - -The only trick to getting it up is that on the slackware dist there is no -init.d directory in /etc/rc.d .. so create one. Then, what I do is take the -IPsec startup script which normally gets put into the init.d directory, and -put it in /etc/rc.d and name ir rc.ipsec .. then I symlink it to the file -in init.d. The only file in the dist you need to really edit is the -utils/Makefile, setup4: - -Everything else should be just fine.</pre> - -<p>A year or so later:</p> -<pre>Subject: Re: HTML Docs- Need some cleanup? - Date: Mon, 8 Jan 2001 - From: Jody McIntyre <jodym@oeone.com> - -I have successfully installed FreeS/WAN on several Slackware 7.1 machines. -FreeS/WAN installed its rc.ipsec file in /etc/rc.d. I had to manually call -this script from rc.inet2. This seems to be an easier method than Evan -Brewer's.</pre> - -<h3><a name="deb">Debian</a></h3> - -<p>A recent (Nov 2001) mailing list points to a <a -href="http://www.thing.dyndns.org/debian/vpn.htm">web page</a> on setting up -several types of tunnel, including IPsec, on Debian.</p> - -<p>Some older information:</p> -<pre>Subject: FreeS/WAN 1.0 on Debian 2.1 - Date: Tue, 20 Apr 1999 - From: Tim Miller <cerebus+counterpane@haybaler.sackheads.org> - - Compiled and installed without error on a Debian 2.1 system -with kernel-source-2.0.36 after pointing RCDIR in utils/Makefile to -/etc/init.d. - - /var/lock/subsys/ doesn't exist on Debian boxen, needs to be -created; not a fatal error. - - Finally, IPsec scripts appear to be dependant on GNU awk -(gawk); the default Debian awk (mawk-1.3.3-2) had fatal difficulties. -With gawk installed and /etc/alternatives/awk linked to /usr/bin/gawk -operation appears flawless.</pre> - -<p>The scripts in question have been modified since this was posted. Awk -versions should no longer be a problem.</p> - -<h3><a name="caldera">Caldera</a></h3> -<pre>Subject: Re: HTML Docs- Need some cleanup? - Date: Mon, 08 Jan 2001 - From: Andy Bradford <andyb@calderasystems.com> - -On Sun, 07 Jan 2001 22:59:05 EST, Sandy Harris wrote: - -> Intel Linux distributions other than Redhat 5.x and 6.x -> Redhat 7.0 -> SuSE Linux -> SuSE Linux 5.3 -> Slackware -> Debian - -Can you please include Caldera in this list? I have tested it since -FreeS/Wan 1.1 and it works great with our systems---provided one -follows the FreeS/Wan documentation. :-) - -Thank you, -Andy</pre> - -<h2><a name="CPUs">CPUs other than Intel</a></h2> - -<p>FreeS/WAN has been run sucessfully on a number of different CPU -architectures. If you have tried it on one not listed here, please post to -the <a href="mail.html">mailing list</a>.</p> - -<h3><a name=" strongarm">Corel Netwinder (StrongARM CPU)</a></h3> -<pre>Subject: linux-ipsec: Netwinder diffs -Date: Wed, 06 Jan 1999 -From: rhatfield@plaintree.com - -I had a mistake in my IPsec-auto, so I got things working this morning. - -Following are the diffs for my changes. Probably not the best and cleanest way -of doing it, but it works. . . . </pre> - -<p>These diffs are in the 0.92 and later distributions, so these should work -out-of-the-box on Netwinder.</p> - -<h3><a name="yellowdog">Yellow Dog Linux on Power PC</a></h3> -<pre>Subject: Compiling FreeS/WAN 1.1 on YellowDog Linux (PPC) - Date: 11 Dec 1999 - From: Darron Froese <darron@fudgehead.com> - -I'm summarizing here for the record - because it's taken me many hours to do -this (multiple times) and because I want to see IPsec on more linuxes than -just x86. - -Also, I can't remember if I actually did summarize it before... ;-) I'm -working too many late hours. - -That said - here goes. - -1. Get your linux kernel and unpack into /usr/src/linux/ - I used 2.2.13. -<http://www.kernel.org/pub/linux/kernel/v2.2/linux-2.2.13.tar.bz2> - -2. Get FreeS/WAN and unpack into /usr/src/freeswan-1.1 -<ftp://ftp.xs4all.nl/pub/crypto/freeswan/freeswan-1.1.tar.gz> - -3. Get the gmp src rpm from here: -<ftp://ftp.yellowdoglinux.com//pub/yellowdog/champion-1.1/SRPMS/SRPMS/gmp-2.0.2-9a.src.rpm> - -4. Su to root and do this: rpm --rebuild gmp-2.0.2-9a.src.rpm - -You will see a lot of text fly by and when you start to see the rpm -recompiling like this: - -Executing: %build -+ umask 022 -+ cd /usr/src/redhat/BUILD -+ cd gmp-2.0.2 -+ libtoolize --copy --force -Remember to add `AM_PROG_LIBTOOL' to `configure.in'. -You should add the contents of `/usr/share/aclocal/libtool.m4' to -`aclocal.m4'. -+ CFLAGS=-O2 -fsigned-char -+ ./configure --prefix=/usr - -Hit Control-C to stop the rebuild. NOTE: We're doing this because for some -reason the gmp source provided with FreeS/WAN 1.1 won't build properly on -ydl. - -cd /usr/src/redhat/BUILD/ -cp -ar gmp-2.0.2 /usr/src/freeswan-1.1/ -cd /usr/src/freeswan-1.1/ -rm -rf gmp -mv gmp-2.0.2 gmp - -5. Open the freeswan Makefile and change the line that says: -KERNEL=$(b)zimage (or something like that) to -KERNEL=vmlinux - -6. cd ../linux/ - -7. make menuconfig -Select an option or two and then exit - saving your changes. - -8. cd ../freeswan-1.1/ ; make menugo - -That will start the whole process going - once that's finished compiling, -you have to install your new kernel and reboot. - -That should build FreeS/WAN on ydl (I tried it on 1.1).</pre> -And a later message on the same topic: -<pre>Subject: Re: FreeS/WAN, PGPnet and E-mail - Date: Sat, 22 Jan 2000 - From: Darron Froese <darron@fudgehead.com> - -on 1/22/00 6:47 PM, Philip Trauring at philip@trauring.com wrote: - -> I have a PowerMac G3 ... - -The PowerMac G3 can run YDL 1.1 just fine. It should also be able to run -FreeS/WAN 1.2patch1 with a couple minor modifications: - -1. In the Makefile it specifies a bzimage for the kernel compile - you have -to change that to vmlinux for the PPC. - -2. The gmp source that comes with FreeS/WAN (for whatever reason) fails to -compile. I have gotten around this by getting the gmp src rpm from here: - -ftp://ftp.yellowdoglinux.com//pub/yellowdog/champion-1.1/SRPMS/SRPMS/gmp-2.0.2-9a.src.rpm - -If you rip the source out of there - and place it where the gmp source -resides it will compile just fine.</pre> - -<p>FreeS/WAN no longer includes GMP source.</p> - -<h3><a name="mklinux">Mklinux</a></h3> - -<p>One user reports success on the Mach-based -<strong>m</strong>icro<strong>k</strong>ernel Linux.</p> -<pre>Subject: Smiles on sparc and ppc - Date: Fri, 10 Mar 2000 - From: Jake Hill <jah@alien.bt.co.uk> - -You may or may not be interested to know that I have successfully built -FreeS/WAN on a number of non intel alpha architectures; namely on ppc -and sparc and also on osfmach3/ppc (MkLinux). I can report that it just -works, mostly, with few changes.</pre> - -<h3><a name="alpha">Alpha 64-bit processors</a></h3> -<pre>Subject: IT WORKS (again) between intel & alpha :-))))) - Date: Fri, 29 Jan 1999 - From: Peter Onion <ponion@srd.bt.co.uk> - -Well I'm happy to report that I've got an IPsec connection between by intel & alpha machines again :-)) - -If you look back on this list to 7th of December I wrote... - --On 07-Dec-98 Peter Onion wrote: --> --> I've about had enuf of wandering around inside the kernel trying to find out --> just what is corrupting outgoing packets... -- --Its 7:30 in the evening ..... -- --I FIXED IT :-)))))))))))))))))))))))))))))))) -- --It was my own fault :-(((((((((((((((((( -- --If you ask me very nicly I'll tell you where I was a little too over keen to --change unsigned long int __u32 :-) OPSE ... -- --So tomorrow it will full steam ahead to produce a set of diffs/patches against --0.91 -- --Peter Onion.</pre> - -<p>In general (there have been some glitches), FreeS/WAN has been running on -Alphas since then.</p> - -<h3><a name="SPARC">Sun SPARC processors</a></h3> - -<p>Several users have reported success with FreeS/WAN on SPARC Linux. Here is -one mailing list message:</p> -<pre>Subject: Smiles on sparc and ppc - Date: Fri, 10 Mar 2000 - From: Jake Hill <jah@alien.bt.co.uk> - -You may or may not be interested to know that I have successfully built -FreeS/WAN on a number of non intel alpha architectures; namely on ppc -and sparc and also on osfmach3/ppc (MkLinux). I can report that it just -works, mostly, with few changes. - -I have a question, before I make up some patches. I need to hack -gmp/mpn/powerpc32/*.s to build them. Is this ok? The changes are -trivial, but could I also use a different version of gmp? Is it vanilla -here? - -I guess my only real headache is from ipchains, which appears to stop -running when IPsec has been started for a while. This is with 2.2.14 on -sparc.</pre> - -<p>This message, from a different mailing list, may be relevant for anyone -working with FreeS/WAN on Suns:</p> -<pre>Subject: UltraSPARC DES assembler - Date: Thu, 13 Apr 2000 - From: svolaf@inet.uni2.dk (Svend Olaf Mikkelsen) - To: coderpunks@toad.com - -An UltraSPARC assembler version of the LibDES/SSLeay/OpenSSL des_enc.c -file is available at http://inet.uni2.dk/~svolaf/des.htm. - -This brings DES on UltraSPARC from slower than Pentium at the same -clock speed to significantly faster.</pre> - -<h3><a name="mips">MIPS processors</a></h3> - -<p>We know FreeS/WAN runs on at least some MIPS processors because <a -href="http://www.lasat.com">Lasat</a> manufacture an IPsec box based on an -embedded MIPS running Linux with FreeS/WAN. We have no details.</p> - -<h3><a name="crusoe">Transmeta Crusoe</a></h3> - -<p>The Merilus <a -href="http://www.merilus.com/products/fc/index.shtml">Firecard</a>, a Linux -firewall on a PCI card, is based on a Crusoe processor and supports -FreeS/WAN.</p> - -<h3><a name="coldfire">Motorola Coldfire</a></h3> -<pre>Subject: Re: Crypto hardware support - Date: Mon, 03 Jul 2000 - From: Dan DeVault <devault@tampabay.rr.com> - -.... I have been running -uClinux with FreeS/WAN 1.4 on a system built by Moreton Bay ( -http://www.moretonbay.com ) and it was using a Coldfire processor -and was able to do the Triple DES encryption at just about -1 mbit / sec rate....... they put a Hi/Fn 7901 hardware encryption -chip on their board and now their system does over 25 mbit of 3DES -encryption........ pretty significant increase if you ask me.</pre> - -<h2><a name="multiprocessor">Multiprocessor machines</a></h2> - -<p>FreeS/WAN is designed to work on SMP (symmetric multi-processing) Linux -machines and is regularly tested on dual processor x86 machines.</p> - -<p>We do not know of any testing on multi-processor machines with other CPU -architectures or with more than two CPUs. Anyone who does test this, please -report results to the <a href="mail.html">mailing list</a>.</p> - -<p>The current design does not make particularly efficient use of -multiprocessor machines; some of the kernel work is single-threaded.</p> - -<h2><a name="hardware">Support for crypto hardware</a></h2> - -<p>Supporting hardware cryptography accelerators has not been a high priority -for the development team because it raises a number of fairly complex -issues:</p> -<ul> - <li>Can you trust the hardware? If it is not Open Source, how do you audit - its security? Even if it is, how do you check that the design has no - concealed traps?</li> - <li>If an interface is added for such hardware, can that interface be - subverted or misused?</li> - <li>Is hardware acceleration actually a performance win? It clearly is in - many cases, but on a fast machine it might be better to use the CPU for - the encryption than to pay the overheads of moving data to and from a - crypto board.</li> - <li>the current KLIPS code does not provide a clean interface for hardware - accelerators</li> -</ul> - -<p>That said, we have a <a href="#coldfire">report</a> of FreeS/WAN working -with one crypto accelerator and some work is going on to modify KLIPS to -create a clean generic interface to such products. See this <a -href="http://www.jukie.net/~bart/linux-ipsec/">web page</a> for some of the -design discussion.</p> - -<p>More recently, a patch to support some hardware accelerators has been -posted:</p> -<pre>Subject: [Design] [PATCH] H/W acceleration patch - Date: Tue, 18 Sep 2001 - From: "Martin Gadbois" <martin.gadbois@colubris.com> - -Finally!! -Here's a web site with H/W acceleration patch for FreeS/WAN 1.91, including -S/W and Hifn 7901 crypto support. - -http://sources.colubris.com/ - -Martin Gadbois</pre> - -<p>Hardware accelerators could take performance well beyond what FreeS/WAN -can do in software (discussed <a href="performance.html">here</a>). Here is -some discussion off the IETF IPsec list, October 2001:</p> -<pre> ... Currently shipping chips deliver, 600 mbps throughput on a single - stream of 3DES IPsec traffic. There are also chips that use multiple - cores to do 2.4 gbps. We (Cavium) and others have announced even faster - chips. ... Mid 2002 versions will handle at line rate (OC48 and OC192) - IPsec and SSL/TLS traffic not only 3DES CBC but also AES and arc4.</pre> - -<p>The patches to date support chips that have been in production for some -time, not the state-of-the-art latest-and-greatest devices described in that -post. However, they may still outperform software and they almost certainly -reduce CPU overhead.</p> - -<h2><a name="ipv6">IP version 6 (IPng)</a></h2> - -<p>The Internet currently runs on version four of the IP protocols. IPv4 is -what is in the standard Linux IP stack, and what FreeS/WAN was built for. In -IPv4, IPsec is an optional feature.</p> - -<p>The next version of the IP protocol suite is version six, usually -abbreviated either as "IPv6" or as "IPng" for "IP: the next generation". For -IPv6, IPsec is a required feature. Any machine doing IPv6 is required to -support IPsec, much as any machine doing (any version of) IP is required to -support ICMP.</p> - -<p>There is a Linux implementation of IPv6 in Linux kernels 2.2 and above. -For details, see the <a -href="http://www.cs-ipv6.lancs.ac.uk/ipv6/systems/linux/faq/">FAQ</a>. It -does not yet support IPsec. The <a -href="http://www.linux-ipv6.org/">USAGI</a> project are also working on IPv6 -for Linux.</p> - -<p>FreeS/WAN was originally built for the current standard, IPv4, but we are -interested in seeing it work with IPv6. Some progress has been made, and a -patched version with IPv6 support is <a -href="http://www.ipv6.iabg.de/downloadframe/index.html">available</a>. For -more recent information, check the <a href="mail.html">mailing list</a>.</p> - -<h3><a name="v6.back">IPv6 background</a></h3> - -<p>IPv6 has been specified by an IETF <a -href="http://www.ietf.org/html.charters/ipngwg-charter.html">working -group</a>. The group's page lists over 30 RFCs to date, and many Internet -Drafts as well. The overview is <a -href="http://www.ietf.org/rfc/rfc2460.txt">RFC 2460</a>. Major features -include:</p> -<ul> - <li>expansion of the address space from 32 to 128 bits,</li> - <li>changes to improve support for - <ul> - <li>mobile IP</li> - <li>automatic network configuration</li> - <li>quality of service routing</li> - <li>...</li> - </ul> - </li> - <li>improved security via IPsec</li> -</ul> - -<p>A number of projects are working on IPv6 implementation. A prominent Open -Source effort is <a href="http://www.kame.net/">KAME</a>, a collaboration -among several large Japanese companies to implement IPv6 for Berkeley Unix. -Other major players are also working on IPv6. For example, see pages at:</p> -<ul> - <li><a - href="http://playground.sun.com/pub/ipng/html/ipng-main.html">Sun</a></li> - <li><a - href="http://www.cisco.com/warp/public/732/ipv6/index.html">Cisco</a></li> - <li><a - href="http://www.microsoft.com/windows2000/techinfo/howitworks/communications/networkbasics/IPv6.asp">Microsoft</a></li> -</ul> - -<p>The <a href="http://www.6bone.net/">6bone</a> (IPv6 backbone) testbed -network has been up for some time. There is an active <a -href="http://www.ipv6.org/">IPv6 user group</a>.</p> - -<p>One of the design goals for IPv6 was that it must be possible to convert -from v4 to v6 via a gradual transition process. Imagine the mess if there -were a "flag day" after which the entire Internet used v6, and all software -designed for v4 stopped working. Almost every computer on the planet would -need major software changes! There would be huge costs to replace older -equipment. Implementers would be worked to death before "the day", systems -administrators and technical support would be completely swamped after it. -The bugs in every implementation would all bite simultaneously. Large chunks -of the net would almost certainly be down for substantial time periods. -...</p> - -<p>Fortunately, the design avoids any "flag day". It is therefore a little -tricky to tell how quickly IPv6 will take over. The transition has certainly -begun. For examples, see announcements from <a -href="http://www.mailbase.ac.uk/lists/internet2/2000-03/0016.html">NTT</a> -and <a href="http://www.vnunet.com/News/1102383">Nokia</a>. However, it is -not yet clear how quickly the process will gain momentum, or when it will be -completed. Likely large parts of the Internet will remain with IPv4 for years -to come.</p> -</body> -</html> diff --git a/doc/src/config.html b/doc/src/config.html deleted file mode 100644 index b98e452db..000000000 --- a/doc/src/config.html +++ /dev/null @@ -1,394 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>FreeS/WAN configuration</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, installation, quickstart"> - <!-- - - Written by Claudia Schmeing for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: config.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> -<BODY> -<H1><A NAME="config">How to configure FreeS/WAN</A></H1> - -<P>This page will teach you how to configure a simple network-to-network -link or a Road Warrior connection between two Linux FreeS/WAN boxes. -</P> - -<P>See also these related documents:</P> -<UL> -<LI>our <A HREF="quickstart.html#quickstart">quickstart</A> guide -to <A HREF="glossary.html#carpediem">opportunistic encryption</A></LI> -<LI>our guide to configuration with -<A HREF="policygroups.html#policygroups">policy groups</A></LI> -<LI>our -<A HREF="adv_config.html#adv_config">advanced configuration</A> -document</LI> -</UL> -<P> -The network-to-network setup allows you to connect two office -networks into one Virtual Private Network, while the Road Warrior -connection secures a laptop's telecommute to work. -Our examples also show the basic procedure on the Linux FreeS/WAN side where -another IPsec peer is in play.</P> - -<P> -Shortcut to <A HREF="#config.netnet">net-to-net</A>.<BR> -Shortcut to <A HREF="#config.rw">Road Warrior</A>. -</P> - -<H2>Requirements</H2> - -<P>To configure the network-to-network connection you must have:</P> -<UL> -<LI>two Linux gateways with static IPs</LI> -<LI>a network behind each gate. Networks must have non-overlapping IP ranges.</LI> -<LI>Linux FreeS/WAN <A HREF="install.html#install">installed</A> - on both gateways</LI> -<LI><A HREF="http://www.tcpdump.org"><VAR>tcpdump</VAR></A> on the local gate, - to test the connection</LI> -</UL> -<P>For the Road Warrior you need:</P> -<UL> -<LI>one Linux box with a static IP</LI> -<LI>a Linux laptop with a dynamic IP</LI> -<LI>Linux FreeS/WAN installed on both</LI> -<LI>for testing, <VAR>tcpdump</VAR> on your gateway or laptop</LI> -</UL> - -<P>If both IPs are dynamic, your situation is a bit trickier. Your best bet -is a variation on the <A HREF="#config.rw">Road Warrior</A>, as described -in <A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00282.html">this mailing list message</A>. - -<H2><A name="config.netnet"></A>Net-to-Net connection</H2> - - -<H3><A name="netnet.info.ex">Gather information</A></H3> - -<P>For each gateway, compile the following information:</P> -<UL> -<LI>gateway IP</LI> -<LI>IP range of the subnet you will be protecting. This doesn't have to - be your whole physical subnet.</LI> -<LI>a name by which that gateway can identify itself for IPsec -negotiations. Its form is a Fully Qualified Domain Name preceded by -an @ sign, ie. @xy.example.com. -<BR>It does not need to be within a domain that you own. It can be a made-up -name.</LI> -</UL> - - -<H4>Get your leftrsasigkey</H4> -<P>On your local Linux FreeS/WAN gateway, print your IPsec public key:</P> -<PRE> ipsec showhostkey --left</PRE> -<P>The output should look like this (with the key shortened for easy - reading):</P> -<PRE> # RSA 2048 bits xy.example.com Fri Apr 26 15:01:41 2002 - leftrsasigkey=0sAQOnwiBPt...</PRE> - -<P>Don't have a key? Use -<A HREF="manpage.d/ipsec_newhostkey.8.html"><VAR>ipsec newhostkey</VAR></A> -to create one. - -<H4>...and your rightrsasigkey</H4> -<P>Get a console on the remote side:</P> -<PRE> ssh2 ab.example.com</PRE> -<P>In that window, type:</P> -<PRE> ipsec showhostkey --right</PRE> -<P>You'll see something like:</P> -<PRE> # RSA 2192 bits ab.example.com Thu May 16 15:26:20 2002 - rightrsasigkey=0sAQOqH55O...</PRE> - -<H3>Edit <VAR>/etc/ipsec.conf</VAR></H3> - -<P>Back on the local gate, copy our template to <VAR>/etc/ipsec.conf</VAR>. -(on Mandrake, <VAR>/etc/freeswan/ipsec.conf</VAR>). -Substitute the information you've gathered for our example data.</P> -<PRE>conn net-to-net - left=192.0.2.2 # Local vitals - leftsubnet=192.0.2.128/29 # - leftid=@xy.example.com # - leftrsasigkey=0s1LgR7/oUM... # - leftnexthop=%defaultroute # correct in many situations - right=192.0.2.9 # Remote vitals - rightsubnet=10.0.0.0/24 # - rightid=@ab.example.com # - rightrsasigkey=0sAQOqH55O... # - rightnexthop=%defaultroute # correct in many situations - auto=add # authorizes but doesn't start this - # connection at startup</PRE> - -<P> -"Left" and "right" should represent the machines that have FreeS/WAN installed -on them, and "leftsubnet" and "rightsubnet" machines that are being protected. -/32 is assumed for left/right and left/rightsubnet parameters. -</P> - -<P>Copy <VAR>conn net-to-net</VAR> to the remote-side /etc/ipsec.conf. -If you've made no other modifications to either <VAR>ipsec.conf</VAR>, -simply:</P> -<PRE> scp2 ipsec.conf root@ab.example.com:/etc/ipsec.conf</PRE> - -<H3>Start your connection</H3> - -<P>Locally, type:</P> -<PRE> ipsec auto --up net-to-net</PRE> - -<P>You should see:</P> -<PRE> 104 "net-net" #223: STATE_MAIN_I1: initiate - 106 "net-net" #223: STATE_MAIN_I2: sent MI2, expecting MR2 - 108 "net-net" #223: STATE_MAIN_I3: sent MI3, expecting MR3 - 004 "net-net" #223: STATE_MAIN_I4: ISAKMP SA established - 112 "net-net" #224: STATE_QUICK_I1: initiate - 004 "net-net" #224: STATE_QUICK_I2: sent QI2, IPsec SA established</PRE> - -<P>The important thing is <VAR>IPsec SA established</VAR>. If you're -unsuccessful, see our -<A HREF="trouble.html#trouble">troubleshooting tips</A>.</P> - - -<H3>Do not MASQ or NAT packets to be tunneled</H3> - -<P>If you are using <A HREF="glossary.html#masq">IP masquerade</A> or -<A HREF="glossary.html#NAT.gloss">Network Address Translation (NAT)</A> -on either gateway, -you must now exempt the packets you wish to tunnel from this treatment. -For example, if you have a rule like:</P> - -<PRE>iptables -t nat -A POSTROUTING -o eth0 -s 10.0.0.0/24 -j MASQUERADE -</PRE> - -<P>change it to something like:</P> -<PRE>iptables -t nat -A POSTROUTING -o eth0 -s 10.0.0.0/24 -d \! 192.0.2.128/29 -j MASQUERADE</PRE> - -<P>This may be necessary on both gateways.</P> - - -<H3>Test your connection</H3> - -<P>Sit at one of your local subnet nodes (not the gateway), and ping a subnet -node on the other (again, not the gateway).</P> - -<PRE> ping fileserver.toledo.example.com</PRE> - -<P>While still pinging, go to the local gateway and snoop your outgoing -interface, for example:</P> -<PRE> tcpdump -i ppp0</PRE> -<P>You want to see ESP (Encapsulating Security Payload) packets moving -<B>back and forth</B> between the two gateways at the same frequency as -your pings:</P> -<PRE> 19:16:32.046220 192.0.2.2 > 192.0.2.9: ESP(spi=0x3be6c4dc,seq=0x3) - 19:16:32.085630 192.0.2.9 > 192.0.2.2: ESP(spi=0x5fdd1cf8,seq=0x6)</PRE> - -<P>If you see this, congratulations are in order! You have a tunnel which -will protect any IP data from one subnet -to the other, as it passes between the two gates. -If not, go and <A HREF="trouble.html#trouble">troubleshoot</A>.</P> - -<P>Note: your new tunnel protects only net-net traffic, not -gateway-gateway, or gateway-subnet. If you need this (for example, if -machines on one net need to securely contact a fileserver on the -IPsec gateway), you'll need to create -<A HREF="adv_config.html#adv_config">extra connections</A>.</P> - - -<H3>Finishing touches</H3> - -<P>Now that your connection works, name it something sensible, like:</P> -<PRE>conn winstonnet-toledonet</PRE> -<P>To have the tunnel come up on-boot, replace</P> -<PRE> auto=add</PRE> -<P>with:</P> -<PRE> auto=start</PRE> -<P>Copy these changes to the other side, for example:</P> -<PRE> scp2 ipsec.conf root@ab.example.com:/etc/ipsec.conf</PRE> -<P>Enjoy!</P> - - - -<H2><A name="config.rw"></A>Road Warrior Configuration</H2> - -<H3><A name="rw.info.ex">Gather information</A></H3> - -<P>You'll need to know:</P> -<UL> -<LI>the gateway's static IP</LI> -<LI>the IP range of the subnet behind that gateway</LI> -<LI>a name by which each side can identify itself for IPsec -negotiations. Its form is a Fully Qualified Domain Name preceded by -an @ sign, ie. @road.example.com. -<BR>It does not need to be within a domain that you own. It can be a made-up -name.</LI> -</UL> - -<H4>Get your leftrsasigkey...</H4> -<P>On your laptop, print your IPsec public key:</P> -<PRE> ipsec showhostkey --left</PRE> -<P>The output should look like this (with the key shortened for easy - reading):</P> -<PRE> # RSA 2192 bits road.example.com Sun Jun 9 02:45:02 2002 - leftrsasigkey=0sAQPIPN9uI...</PRE> - -<P>Don't have a key? See -<A HREF="old_config.html#genrsakey">these instructions</A>. - - -<H4>...and your rightrsasigkey</H4> -<P>Get a console on the gateway:</P> -<PRE> ssh2 xy.example.com</PRE> -<P>View the gateway's public key with:</P> -<PRE> ipsec showhostkey --right</PRE> -<P>This will yield something like</P> -<PRE> # RSA 2048 bits xy.example.com Fri Apr 26 15:01:41 2002 - rightrsasigkey=0sAQOnwiBPt...</PRE> - - -<H3>Customize <VAR>/etc/ipsec.conf</VAR></H3> - -<P>On your laptop, copy this template to <VAR>/etc/ipsec.conf</VAR>. -(on Mandrake, <VAR>/etc/freeswan/ipsec.conf</VAR>). -Substitute the information you've gathered for our example data.</P> -<PRE>conn road - left=%defaultroute # Picks up our dynamic IP - leftnexthop=%defaultroute # - leftid=@road.example.com # Local information - leftrsasigkey=0sAQPIPN9uI... # - right=192.0.2.10 # Remote information - rightsubnet=10.0.0.0/24 # - rightid=@xy.example.com # - rightrsasigkey=0sAQOnwiBPt... # - auto=add # authorizes but doesn't start this - # connection at startup</PRE> - -<P>The template for the gateway is different. Notice how it -reverses <VAR>left</VAR> and <VAR>right</VAR>, in keeping with our -convention that <STRONG>L</STRONG>eft is <STRONG>L</STRONG>ocal, -<STRONG>R</STRONG>ight <STRONG>R</STRONG>emote. Be sure to switch your -rsasigkeys in keeping with this.</P> - -<PRE> ssh2 xy.example.com - vi /etc/ipsec.conf</PRE> - -<P>and add:</P> - -<PRE>conn road - left=192.0.2.2 # Gateway's information - leftid=@xy.example.com # - leftsubnet=192.0.2.128/29 # - leftrsasigkey=0sAQOnwiBPt... # - rightnexthop=%defaultroute # correct in many situations - right=%any # Wildcard: we don't know the laptop's IP - rightid=@road.example.com # - rightrsasigkey=0sAQPIPN9uI... # - auto=add # authorizes but doesn't start this - # connection at startup</PRE> - - - -<H3>Start your connection</H3> - -<P>You must start the connection from the Road Warrior side. On your laptop, -type:</P> -<PRE> ipsec auto --start net-to-net</PRE> - -<P>You should see:</P> -<PRE>104 "net-net" #223: STATE_MAIN_I1: initiate -106 "road" #301: STATE_MAIN_I2: sent MI2, expecting MR2 -108 "road" #301: STATE_MAIN_I3: sent MI3, expecting MR3 -004 "road" #301: STATE_MAIN_I4: ISAKMP SA established -112 "road" #302: STATE_QUICK_I1: initiate -004 "road" #302: STATE_QUICK_I2: sent QI2, IPsec SA established</PRE> - -<P>Look for <VAR>IPsec SA established</VAR>. If you're -unsuccessful, see our -<A HREF="trouble.html#trouble">troubleshooting tips</A>.</P> - - - -<H3>Do not MASQ or NAT packets to be tunneled</H3> - -<P>If you are using <A HREF="glossary.html#masq">IP masquerade</A> or -<A HREF="glossary.html#NAT.gloss">Network Address Translation (NAT)</A> -on either gateway, -you must now exempt the packets you wish to tunnel from this treatment. -For example, if you have a rule like:</P> - -<PRE>iptables -t nat -A POSTROUTING -o eth0 -s 10.0.0.0/24 -j MASQUERADE -</PRE> - -<P>change it to something like:</P> -<PRE>iptables -t nat -A POSTROUTING -o eth0 -s 10.0.0.0/24 -d \! 192.0.2.128/29 -j MASQUERADE</PRE> - - -<H3>Test your connection</H3> - -<P>From your laptop, ping a subnet node behind the remote gateway. Do not -choose the gateway itself for this test.</P> - -<PRE> ping ns.winston.example.com</PRE> - -<P>Snoop the packets exiting the laptop, with a command like:</P> -<PRE> tcpdump -i wlan0</PRE> -<P>You have success if you see (Encapsulating Security Payload) packets -travelling <B>in both directions</B>:</P> - -<PRE> 19:16:32.046220 192.0.2.2 > 192.0.2.9: ESP(spi=0x3be6c4dc,seq=0x3) - 19:16:32.085630 192.0.2.9 > 192.0.2.2: ESP(spi=0x5fdd1cf8,seq=0x6)</PRE> - - -<P>If you do, great! Traffic between your Road Warrior and the net -behind your gateway is protected. -If not, see our -<A HREF="trouble.html#trouble">troubleshooting hints</A>.</P> - -<P>Your new tunnel protects only traffic addressed to the net, not to -the IPsec gateway itself. If you need the latter, you'll want to make an -<A HREF="adv_config.html#adv_config">extra tunnel.</A>.</P> - -<H3>Finishing touches</H3> - -<P>On both ends, name your connection wisely, like:</P> -<PRE>conn mike-to-office</PRE> -<P><B>On the laptop only,</B> replace</P> -<PRE> auto=add</PRE> -<P>with:</P> -<PRE> auto=start</PRE> -<P>so that you'll be connected on-boot.</P> -<P>Happy telecommuting!</P> - -<H3>Multiple Road Warriors</H3> - -<P>If you're using RSA keys, as we did in this example, you can add -as many Road Warriors as you like. The left/rightid -parameter lets Linux FreeS/WAN distinguish between multiple Road Warrior -peers, each with its own public key.</P> - -<P>The situation is different for shared secrets (PSK). During a -PSK negotiation, ID information is not available at the time Pluto -is trying to determine which secret to use, so, effectively, you can -only define one Roadwarrior connection. All your PSK road warriors -must therefore share one secret.</P> - - -<H2>What next?</H2> - -<P>Using the principles illustrated here, you can try variations such as: -<UL> -<LI>a telecommuter with a static IP</LI> -<LI>a road warrior with a subnet behind it</LI> -</UL> -<P>Or, look at some of our <A HREF="adv_config.html#adv_config">more complex configuration examples.</A>.</P> -</BODY> -</HTML> diff --git a/doc/src/crosscompile.html b/doc/src/crosscompile.html deleted file mode 100644 index c488957c8..000000000 --- a/doc/src/crosscompile.html +++ /dev/null @@ -1,105 +0,0 @@ -<HTML>
-<HEAD>
- <TITLE>Cross Compiling FreeS/WAN</TITLE>
- <meta name="keywords" content="Linux, IPSEC, VPN, Security, FreeSWAN, cross, compile">
-<!--
- Written by Ken Bantoft <ken@freeswan.ca> for the Linux FreeS/WAN project
- Freely distributable under the GNU General Public License
-
- More information at www.freeswan.org
- Feedback to users@lists.freeswan.org
-
-CVS information:
-RCS ID: $Id: crosscompile.html,v 1.1 2004/03/15 20:35:24 as Exp $
-Last changed: $Date: 2004/03/15 20:35:24 $
-Revision number: $Revision: 1.1 $
-
-CVS revision numbers do not correspond to FreeS/WAN release numbers.
--->
-
-</HEAD>
-<BODY>
-
-<H1><A NAME="guide"></A>Linux FreeS/WAN Cross Compiling Guide</H1>
-
-<H2><A NAME="overview"></A>Overview</H2>
-
-<P>
-This document provides general instructions on how to cross compile
-FreeS/WAN,
-that is - compile it for another architecture (eg: StrongARM)</P>
-<OL>
- <LI><A HREF="#setup">Setting up your environment</A>.</LI>
- <LI><A HREF="#building">Building</A>.</LI>
- <LI><A HREF="#common">Common Problems</A>.</LI>
-</OL>
-<H2><A NAME="setup"></A>Setting up your Environment</H2>
-<H3>Enviroment Variables</H3>
-<P>There are a number of environment variables you can set to help facilitate
-cross compiling FreeS/WAN. All examples will are using the bash shell.
-</P>
-<P>The following is an example of the how to set the environment variables if
-you were cross compiling using the Embedix ARM toolchain, to build for an embedded
-device like the Sharp Zaurus. Set these while you are in the FreeS/WAN directory.
-It is often simpler to put the entire list into a script (eg: cross-setup.sh), and
-then "source cross-setup.sh" or similar.
-<pre>
-export ARCH=arm
-export CC=/opt/Embedix/tools/bin/arm-linux-gcc
-export LD=/opt/Embedix/tools/bin/arm-linux-ld
-export RANLIB=/opt/Embedix/tools/bin/arm-linux-ranlib
-export AR=/opt/Embedix/tools/bin/arm-linux-ar
-export AS=/opt/Embedix/tools/bin/arm-linux-as
-export STRIP=/opt/Embedix/tools/bin/arm-linux-strip
-export KERNELSRC=/zaurus/kernel-2.4.6
-export LD_LIBRARY_PATH=/opt/Embedix/tools/lib/gcc-lib/arm-linux/2.95.2/
-export PATH=$PATH:/opt/Embedix/tools/bin
-export DESTDIR=/zaurus/binaries
-</pre>
-In the example above, we setup all of the usual gcc + bin-utils programs,
-as well as setting the LD_LIBRARY_PATH to our cross-compiled system libraries,
-and DESTDIR to our output directory.
-</P>
-
-<H3>Kernel Source</H3>
-<P>Place a copy of the kernel source, setup for your target device somewhere on
-your filesystem and set KERNELSRC= to this directory. You will need to prepare
-your kernel source treefirst, by running "make menuconfig && make dep && make
-modules". Once this is done, you can move on to building FreeS/WAN</P>
-
-<H2><A NAME="building"></A>Building</H2>
-<H3>The Make Process</H3>
-<P>There are two parts to building FreeS/WAN - the userland programs and utilities,
-and the ipsec.o kernel module. Each can be built seperatly, making debugging the
-build process simpler.
-</P>
-<P>Step 1 is to run "make programs". This will build the required libs
-(libfreeswan.a) as well as all of the userland tools (pluto, whack, etc...).
-Provided your environment variables are set correctly, you should see the output
-using your specified gcc (arm-linux-gcc for our example), ld, as, ar and
-ranlib.</P>
-<P>If this completes successfully, you can run "make install" to install a copy of
-all of the binaries, man pages and other documentation to DESTDIR.</P>
-<P>Step 2 is to build the ipsec.o module. This is done with "make oldmod", which
-should change into the KERNELSRC directory and then compile and link the required
-files to generate an ipsec.o file. If this is successful, you will end up with an
-ipsec.o file in your FreeS/WAN directory, under linux/net/ipsec/.</P>
-<P>Remember to install this to /lib/modules/$kernelversion/kernel/net/ipsec/ on
-your target machine.</P>
-
-
-
-<H2><A NAME="common"></A>Common Problems Building</H2>
-<P>Here is a list of common problems/errors you may run into when cross compiling
-FreeS/WAN.</P>
-<UL>
-<LI>gmp.h, libgmp not found, error with -lgmp. All of these refer to the GNU Math
-Precision Library. You will need to have already built this for your target
-system. Place libgmp.so in LD_LIBRARY_PATH, and ensure the headers are in your
-include path as well.
-</UL>
-
-<P><BR><BR>
-</P>
-</BODY>
-</HTML>
diff --git a/doc/src/faq.html b/doc/src/faq.html deleted file mode 100644 index f62fc1c88..000000000 --- a/doc/src/faq.html +++ /dev/null @@ -1,2770 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>FreeS/WAN FAQ</title> - <meta name="keywords" content="Linux, IPsec, VPN, security, FreeSWAN, FAQ"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: faq.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1>FreeS/WAN FAQ</h1> - -<p>This is a collection of questions and answers, mostly taken from the -FreeS/WAN <a href="mail.html">mailing list</a>. See the project <a -href="http://www.freeswan.org/">web site</a> for more information. All the -FreeS/WAN documentation is online there.</p> - -<p>Contributions to the FAQ are welcome. Please send them to the project <a -href="mail.html">mailing list</a>.</p> -<hr> - -<h2><a name="questions">Index of FAQ questions</a></h2> -<ul> - <li><a href="#whatzit">What is FreeS/WAN?</a></li> - <li><a href="#problems">How do I report a problem or seek help?</a></li> - <li><a href="#generic">Can I get ...</a> - <ul> - <li><a href="#lemme_out">... an off-the-shelf system that includes - FreeS/WAN?</a></li> - <li><a href="#contractor">... contractors or staff who know - FreeS/WAN?</a></li> - <li><a href="#commercial">... commercial support?</a></li> - </ul> - </li> - <li><a href="#release">Release questions</a> - <ul> - <li><a href="#rel.current">What is the current release?</a></li> - <li><a href="#relwhen">When is the next release?</a></li> - <li><a href="#rel.bugs">Are there known bugs in the current - release?</a></li> - </ul> - </li> - <li><a href="mod_cons">Modifications and contributions</a> - <ul> - <li><a href="#modify.faq">Can I modify FreeS/WAN to ...?</a></li> - <li><a href="#contrib.faq">Can I contribute to the project?</a></li> - <li><a href="#ddoc.faq">Is there detailed design documentation?</a></li> - </ul> - </li> - <li><a href="#interact">Will FreeS/WAN work in my environment?</a> - <ul> - <li><a href="#interop.faq">Can FreeS/WAN talk to ... ?</a></li> - <li><a href="#old_to_new">Can different FreeS/WAN versions talk to each - other?</a></li> - <li><a href="#faq.bandwidth">Is there a limit on throughput?</a></li> - <li><a href="#faq.number">Is there a limit on number of - connections?</a></li> - <li><a href="#faq.speed">Is a ... fast enough to handle FreeS/WAN with - my loads?</a></li> - </ul> - </li> - <li><a href="#work_on">Will FreeS/WAN work on ...</a> - <ul> - <li><a href="#versions">... my version of Linux?</a></li> - <li><a href="#nonIntel.faq">... non-Intel CPUs?</a></li> - <li><a href="#multi.faq">... multiprocessors?</a></li> - <li><a href="#k.old">... an older kernel?</a></li> - <li><a href="#k.versions">... the latest kernel version?</a></li> - <li><a href="#interface.faq">... unusual network hardware?</a></li> - <li><a href="#vlan">... a VLAN (802.1q) network?</a></li> - </ul> - </li> - <li><a href="#features.faq">Does FreeS/WAN support ...</a> - <ul> - <li><a href="#VPN.faq">... site-to-site VPN applications</a></li> - <li><a href="#warrior.faq">... remote users connecting to a LAN</a></li> - <li><a href="#road.shared.possible">... remote users using shared - secret authentication?</a></li> - <li><a href="#wireless.faq">... wireless networks</a></li> - <li><a href="#PKIcert">... X.509 or other PKI certificates?</a></li> - <li><a href="#Radius">... user authentication (Radius, SecureID, - Smart Card ...)?</a></li> - <li><a href="#NATtraversal">... NAT traversal</a></li> - <li><a href="#virtID">... assigning a "virtual identity" to a remote - system?</a></li> - <li><a href="#noDES.faq">... single DES encryption?</a></li> - <li><a href="#AES.faq">... AES encryption?</a></li> - <li><a href="#other.cipher">... other encryption algorithms?</a></li> - </ul> - </li> - <li><a href="#canI">Can I ...</a> - <ul> - <li><a href="#policy.preconfig">...use policy groups along with - explicitly configured connections?</a></li> - <li><a href="#policy.off">...turn off policy groups?</a></li> -<!-- - <li><a href="#policy.otherinterface">...use policy groups - on an interface other than <VAR>%defaultroute</VAR>?</a></li> ---> - <li><a href="#reload">... reload connection info without - restarting?</a></li> - <li><a href="#masq.faq">... use several masqueraded subnets?</a></li> - <li><a href="#dup_route">... use subnets masqueraded to the same - addresses?</a></li> - <li><a href="#road.masq">... assign a road warrior an address on my net - (a virtual identity)?</a></li> - <li><a href="#road.many">... support many road warriors with one - gateway?</a></li> - <li><a href="#road.PSK">... have many road warriors using shared secret - authentication?</a></li> - <li><a href="#QoS">... use Quality of Service routing with - FreeS/WAN?</a></li> - <li><a href="#deadtunnel">... recognise dead tunnels and shut them - down?</a></li> - <li><a href="#demanddial">... build IPsec tunnels over a demand-dialed - link?</a></li> - <li><a href="#GRE">... build GRE, L2TP or PPTP tunnels over IPsec?</a></li> - <li><a href="#NetBIOS">... use Network Neighborhood (Samba, NetBIOS) over IPsec?</a></li> - </ul> - </li> - <li><a href="#setup.faq">Life's little mysteries</a> - <ul> - <li><a href="#cantping">I cannot ping ....</a></li> - <li><a href="#forever">It takes forever to ...</a></li> - <li><a href="#route">I send packets to the tunnel with route(8) but - they vanish</a></li> - <li><a href="#down_route">When a tunnel goes down, packets - vanish</a></li> - <li><a href="#firewall_ate">The firewall ate my packets!</a></li> - <li><a href="#dropconn">Dropped connections</a></li> - <li><a href="#defaultroutegone">Disappearing %defaultroute</a></li> - <li><a href="#tcpdump.faq">TCPdump on the gateway shows strange - things</a></li> - <li><a href="#no_trace">Traceroute does not show anything between the - gateways</a></li> - </ul> - </li> - <li><a href="#man4debug">Testing in stages (or .... works but ... - doesn't)</a> - <ul> - <li><a href="#nomanual">Manually keyed connections don't work</a></li> - <li><a href="#spi_error">One manual connection works, but second one - fails</a></li> - <li><a href="#man_no_auto">Manual connections work, but automatic - keying doesn't</a></li> - <li><a href="#nocomp">IPsec works, but connections using compression - fail</a></li> - <li><a href="#pmtu.broken">Small packets work, but large transfers - fail</a></li> - <li><a href="#subsub">Subnet-to-subnet works, but tests from the - gateways don't</a></li> - </ul> - </li> - <li><a href="#compile.faq">Compilation problems</a> - <ul> - <li><a href="#gmp.h_missing">gmp.h: No such file or directory</a></li> - <li><a href="#noVM">... virtual memory exhausted</a></li> - </ul> - </li> - <li><a href="#error">Interpreting error messages</a> - <ul> - <li><a href="#route-client">route-client (or host) exited with status - 7</a></li> - <li><a href="#unreachable">SIOCADDRT:Network is unreachable</a></li> - <li><a href="#modprobe">ipsec_setup: modprobe: Can't locate - moduleipsec</a></li> - <li><a href="#noKLIPS">ipsec_setup: Fatal error, kernel appears to lack - KLIPS</a></li> - <li><a href="#noDNS">ipsec_setup: ... failure to fetch key for ... from - DNS</a></li> - <li><a href="#dup_address">ipsec_setup: ... interfaces ... and ... - share address ...</a></li> - <li><a href="#kflags">ipsec_setup: Cannot adjust kernel flags</a></li> - <li><a href="#message_num">Message numbers (MI3, QR1, et cetera) in - Pluto messages</a></li> - <li><a href="#conn_name">Connection names in Pluto error - messages</a></li> - <li><a href="#cantorient">Pluto: ... can't orient connection</a></li> - <li><a href="#no.interface">... we have no ipsecN interface for either - end of this connection</a></li> - <li><a href="#noconn">Pluto: ... no connection is known</a></li> - <li><a href="#nosuit">Pluto: ... no suitable connection ...</a></li> - <li><a href="#noconn.auth">Pluto: ... no connection has been - authorized</a></li> - <li><a href="#noDESsupport">Pluto: ... OAKLEY_DES_CBC is not - supported.</a></li> - <li><a href="#notransform">Pluto: ... no acceptable transform</a></li> - <li><a href="#rsasigkey">rsasigkey dumps core</a></li> - <li><a href="#sig4">!Pluto failure!: ... exited with ... signal - 4</a></li> - <li><a href="#econnrefused">ECONNREFUSED error message</a></li> - <li><a href="#no_eroute">klips_debug: ... no eroute!</a></li> - <li><a href="#SAused">... trouble writing to /dev/ipsec ... SA already - in use</a></li> - <li><a href="#ignore">... ignoring ... payload</a></li> - <li><a href="#unknown_rightcert">unknown parameter name "rightcert"</a></li> - </ul> - <li><a href="#spam">Why don't you restrict the mailing lists to reduce - spam?</a></li> -</ul> -<hr> - -<h2><a name="whatzit">What is FreeS/WAN?</a></h2> - -<p>FreeS/WAN is a Linux implementation of the <a -href="glossary.html#IPSEC">IPsec</a> protocols, providing security services -at the IP (Internet Protocol) level of the network.</p> - -<p>For more detail, see our <a href="intro.html">introduction</a> document or -the FreeS/WAN project <a href="http://www.freeswan.org/">web site</a>.</p> - -<p>To start setting it up, go to our <a href="quickstart.html">quickstart -guide</a>.</p> - -<p>Our <a href="web.html">web links</a> document has information on <a -href="web.html#implement">IPsec for other systems</a>.</p> - -<h2><a name="problems">How do I report a problem or seek help?</a></h2> - -<DL> -<DT>Read our <a href="trouble.html">troubleshooting</a> document.</DT> -<DD><p>It may guide you to a solution. If not, see its -<a href="trouble.html#prob.report">problem reporting</a> section.</p> - -<p>Basically, what it says is <strong>give us the output from <var>ipsec -barf</var> from both gateways</strong>. Without full information, we cannot -diagnose a problem. However, <var>ipsec barf</var> produces a lot of output. -If at all possible, <strong>please make barfs accessible via the web or -FTP</strong> rather than sending enormous mail messages.</p> -</DD> - -<DT><strong>Use the <a href="mail.html">users mailing list</a> for problem -reports</strong>, rather than mailing developers directly. -</DT> - -<DD> -<ul> - <li>This gives you access to more expertise, including users who may have - encountered and solved the same problems.</li> - <li>It is more likely to get a quick response. Developers may get behind on - email, or even ignore it entirely for a while, but a list message (given - a reasonable Subject: line) is certain to be read by a fair number of - people within hours.</li> - <li>It may also be important because of <a - href="politics.html#exlaw">cryptography export laws</a>. A US citizen who - provides technical assistance to foreign cryptographic work might be - charged under the arms export regulations. Such a charge would be easier - to defend if the discussion took place on a public mailing list than if - it were done in private mail.</li> -</ul> -</DD> - -<DT>Try irc.freenode.net#freeswan.</DT> - -<DD> -<p>FreeS/WAN developers, volunteers and users can often be found there. -Be patient and be -prepared to provide lots of information to support your question.</p> - -<p>If your question was really interesting, and you found an answer, -please share that with the class by posting to the -<a href="mail.html">users mailing list</a>. That way others with the -same problem can find your answer in the archives.</p> -</DD> - -<DT>Premium support is also available.</DT> -<DD> -<p>See the next several questions.</p> -</DD> -</DL> - -<h2><a name="generic">Can I get ...</a></h2> - -<h3><a name="lemme_out">Can I get an off-the-shelf system that includes -FreeS/WAN?</a></h3> - -<p>There are a number of Linux distributions or firewall products which -include FreeS/WAN. See this <a href="intro.html#products">list</a>. Using one -of these, chosen to match your requirements and budget, may save you -considerable time and effort.</p> - -<p>If you don't know your requirements, start by reading Schneier's <a -href="biblio.html#secrets">Secrets and Lies</a>. That gives the best overview -of security issues I have seen. Then consider hiring a consultant (see next -question) to help define your requirements.</p> - -<h3><a name="consultant">Can I hire consultants or staff who know -FreeS/WAN?</a></h3> - -<p>If you want the help of a contractor, or to hire staff with FreeS/WAN -expertise, you could:</p> -<ul> - <li>check availability in your area through your local Linux User Group (<a - href="http://lugww.counter.li.org/">LUG Index</a>)</li> - <li>try asking on our <a href="mail.html">mailing list</a></li> -</ul> - -<p>For companies offerring support, see the next question.</p> - -<h3><a name="commercial">Can I get commercial support?</a></h3> - -<p>Many of the distributions or firewall products which include FreeS/WAN -(see this <a href="intro.html#products">list</a>) come with commercial -support or have it available as an option.</p> - -<p>Various companies specialize in commercial support of open source -software. Our project leader was a founder of the first such company, Cygnus -Support. It has since been bought by <a -href="http://www.redhat.com">Redhat</a>. Another such firm is <a -href="http://www.linuxcare.com">Linuxcare</a>.</p> - -<h2><a name="release">Release questions</a></h2> - -<h3><a name="rel.current">What is the current release?</a></h3> - -<p>The current release is the highest-numbered tarball on our <a -href="ftp://ftp.xs4all.nl/pub/crypto/freeswan">distribution site</a>. Almost -always, any of <a href="intro.html#mirrors">the mirrors</a> will have the -same file, though perhaps not for a day or so after a release.</p> - -<p>Unfortunately, the web site is not always updated as quickly as it should -be.</p> - -<h3><a name="relwhen">When is the next release?</a></h3> - -<p>We try to do a release approximately every six to eight weeks. -</p> - -<p>If pre-release tests fail and the fix appears complex, or more generally -if the code does not appear stable when a release is scheduled, we will just -skip that release.</p> - -<p>For serious bugs, we may bring out an extra bug-fix release. These get -numbers in the normal release series. For example, there was a bug found in -FreeS/WAN 1.6, so we did another release less than two weeks later. The -bug-fix release was called 1.7.</p> - -<h3><a name="rel.bugs">Are there known bugs in the current release?</a></h3> - -<p>Any problems we are aware of at the time of a release are documented in -the <a href="../BUGS">BUGS</a> file for that release. You should also look at -the <a href="../CHANGES">CHANGES</a> file.</p> - -<p>Bugs discovered after a release are discussed on the <a -href="mail.html">mailing lists</a>. The easiest way to check for any problems -in the current code would be to peruse the -<a href="http://lists.freeswan.org/pipermail/briefs">List In Brief</a>.</p> - -<h2><a name="mod_cons">Modifications and contributions</a></h2> - -<h3><a name="modify.faq">Can I modify FreeS/WAN to ...?</a></h3> - -<p>You are free to modify FreeS/WAN in any way. See the discussion of <a -href="intro.html#licensing">licensing</a> in our introduction document.</p> - -<p>Before investing much energy in any such project, we suggest that you</p> -<ul> - <li>check the list of <a href="web.html#patch">existing patches</a></li> - <li>post something about your project to the <a href="mail.html">design - mailing list</a></li> -</ul> - -<p>This may prevent duplicated effort, or lead to interesting -collaborations.</p> - -<h3><a name="contrib.faq">Can I contribute to the project?</a></h3> -In general, we welcome contributions from the community. Various contributed -patches, either to fix bugs or to add features, have been incorporated into -our distribution. Other patches, not yet included in the distribution, are -listed in our <a href="web.html#patch">web links</a> section. - -<p>Users have also contributed heavily to documentation, both by creating -their own <a href="intro.html#howto">HowTos</a> and by posting things on the -<a href="mail.html">mailing lists</a> which I have quoted in these HTML -docs.</p> - -<p>There are, however, some caveats.</p> - -<p>FreeS/WAN is being implemented in Canada, by Canadians, largely to ensure -that is it is entirely free of export restrictions. See this <a -href="politics.html#status">discussion</a>. We <strong>cannot accept code -contributions from US residents or citizens</strong>, not even one-line bugs -fixes. The reasons for this were recently discussed extensively on the -mailing list, in a thread starting <a -href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/01/msg00111.html">here</a>.</p> - -<p>Not all contributions are of interest to us. The project has a set of -fairly ambitious and quite specific goals, described in our <a -href="intro.html#goals">introduction</a>. Contributions that lead toward -these goals are likely to be welcomed enthusiastically. Other contributions -may be seen as lower priority, or even as a distraction.</p> - -<p>Discussion of possible contributions takes place on the <a -href="mail.html">design mailing list</a>.</p> - -<h3><a name="ddoc.faq">Is there detailed design documentation?</a></h3> -There are: -<ul> - <li><a href="rfc.html">RFCs</a> specifying the protocols we implement</li> - <li><a href="manpages.html">man pages</a> for our utilities, library - functions and file formats</li> - <li>comments in the source code</li> - <li><a href="index.html">HTML documentation</a> written primarily for - users</li> - <li>archived discussions from the <a href="mail.html">mailing lists</a></li> - <li>other papers mentioned in our <a - href="intro.html#applied">introduction</a></li> -</ul> - -<p>The only formal design documents are a few papers in the last category -above. All the other categories, however, have things to say about design as -well.</p> - -<h2><a name="interact">Will FreeS/WAN work in my environment?</a></h2> - -<h3><a name="interop.faq">Can FreeS/WAN talk to ...?</a></h3> - -<p>The IPsec protocols are designed to support interoperation. In theory, any -two IPsec implementations should be able to talk to each other. In practice, -it is considerably more complex. We have a whole <a -href="interop.html">interoperation document</a> devoted to this problem.</p> - -<p>An important part of that document is links to the many <a -href="interop.html#otherpub">user-written HowTos</a> on interoperation -between FreeS/WAN and various other implementations. Often the users know -more than the developers about these issues (and almost always more than me -:-), so these documents may be your best resource.</p> - -<h3><a name="old_to_new">Can different FreeS/WAN versions talk to each -other?</a></h3> - -<p>Linux FreeS/WAN can interoperate with many IPsec implementations, -including earlier versions of Linux FreeS/WAN itself.</p> - -<p>In a few cases, there are some complications. See our <a -href="interop.html#oldswan">interoperation</a> document for details.</p> - -<h3><a name="faq.bandwidth">Is there a limit on throughput?</a></h3> - -<p>There is no hard limit, but see below.</p> - -<h3><a name="faq.number">Is there a limit on number of tunnels?</a></h3> - -<p>There is no hard limit, but see next question.</p> - -<h3><a name="faq.speed">Is a ... fast enough to handle FreeS/WAN with my -loads?</a></h3> - -<p>A quick summary:</p> -<dl> - <dt>Even a limited machine can be useful</dt> - <dd>A 486 can handle a T1, ADSL or cable link, though the machine may be - breathing hard.</dd> - <dt>A mid-range PC (say 800 MHz with good network cards) can do a lot of - IPsec</dt> - <dd>With up to roughly 50 tunnels and aggregate bandwidth of 20 Megabits - per second, it willl have cycles left over for other tasks.</dd> - <dt>There are limits</dt> - <dd>Even a high end CPU will not come close to handling a fully loaded - 100 Mbit/second Ethernet link. - <p>Beyond about 50 tunnels it needs careful management.</p> - </dd> -</dl> - -<p>See our <a href="performance.html">FreeS/WAN performance</a> document for -details.</p> - -<h2><a name="work_on">Will FreeS/WAN work on ... ?</a></h2> - -<h3><a name="versions">Will FreeS/WAN run on my version of Linux?</a></h3> - -<p>We build and test on Redhat distributions, but FreeS/WAN runs just fine on -several other distributions, sometimes with minor fiddles to adapt to the -local environment. Details are in our <a -href="compat.html#otherdist">compatibility</a> document. Also, some -distributions or products come with <a href="intro.html#products">FreeS/WAN -included</a>.</p> - -<h3><a name="nonIntel.faq">Will FreeS/WAN run on non-Intel CPUs?</a></h3> - -<p>FreeS/WAN is <strong>intended to run on all CPUs Linux supports</strong>. -We know of it being used in production on x86, ARM, Alpha and MIPS. It has -also had successful tests on PPC and SPARC, though we don't know of actual -use there. Details are in our <a href="compat.html#CPUs">compatibility</a> -document.</p> - -<h3><a name="multi.faq">Will FreeS/WAN run on multiprocessors?</a></h3> - -<p>FreeS/WAN is designed to work on any SMP architecture Linux supports, and -has been tested successfully on at least dual processor Intel architecture -machines. Details are in our <a -href="compat.html#multiprocessor">compatibility</a> document.</p> - -<h3><a name="k.old">Will FreeS/WAN work on an older kernel?</a></h3> - -<p>It might, but we strongly recommend using a recent 2.2 or 2.4 series -kernel. Sometimes the newer versions include security fixes which can be -quite important on a gateway.</p> - -<p>Also, we use recent kernels for development and testing, so those are -better tested and, if you do encounter a problem, more easily supported. If -something breaks applying recent FreeS/WAN patches to an older kernel, then -"update your kernel" is almost certain to be the first thing we suggest. It -may be the only suggestion we have.</p> - -<p>The precise kernel versions supported by a particular FreeS/WAN release -are given in the <a href="XX">README</a> file of that release.</p> - -<p>See the following question for more on kernels.</p> - -<h3><a name="k.versions">Will FreeS/WAN run on the latest kernel -version?</a></h3> - -<p>Sometimes yes, but quite often, no.</p> - -<p>Kernel versions supported are given in the <a href="../README">README</a> -file of each FreeS/WAN release. Typically, they are whatever production -kernels were current at the time of our release (or shortly before; we might -release for kernel <var>n</var> just as Linus releases <var>n+1</var>). Often -FreeS/WAN will work on slightly later kernels as well, but of course this -cannot be guaranteed.</p> - -<p>For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the -current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but -2.4.9 had changes that caused compilation errors if it was patched with -FreeS/WAN 1.91.</p> - -<p>When such changes appear, we put a fix in the FreeS/WAN snapshots, and -distribute it with our next release. However, this is not a high priority for -us, and it may take anything from a few days to several weeks for such a -problem to find its way to the top of our kernel programmer's To-Do list. In -the meanwhile, you have two choices:</p> -<ul> - <li>either stick with a slightly older kernel, even if it is not the latest - and greatest. This is recommended for production systems; new versions - may have new bugs.</li> - <li>or fix the problem yourself and send us a patch, via the <a - href="mail.html">Users mailing list</a>.</li> -</ul> - -<p>We don't even try to keep up with kernel changes outside the main 2.2 and -2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 -series of development kernels. We'd rather work on developing the FreeS/WAN -code than on chasing these moving targets. We are, however, happy to get -patches for problems discovered there.</p> - -<p>See also the <a href="install.html#choosek">Choosing a kernel</a> section -of our installation document.</p> - -<h3><a name="interface.faq">Will FreeS/WAN work on unusual network -hardware?</a></h3> - -<p>IPsec is designed to work over any network that IP works over, and -FreeS/WAN is intended to work over any network interface hardware that Linux -supports.</p> - -<p>If you have working IP on some unusual interface -- perhaps Arcnet, Token -Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".</p> - -<p>That said, practice is sometimes less tractable than theory. Our testing -is done almost entirely on:</p> -<ul> - <li>10 or 100 Mbit Ethernet</li> - <li>ADSL or cable connections, with and without PPPoE</li> - <li>IEEE 802.11 wireless LANs (see <a href="#wireless.faq">below</a>)</li> -</ul> - -<p>If you have some other interface, especially an uncommon one, it is -entirely possible you will get bitten either by a FreeS/WAN bug which our -testing did not turn up, or by a bug in the driver that shows up only with -our loads.</p> - -<p>If IP works on your interface and FreeS/WAN doesn't, seek help on the <a -href="mail.html">mailing lists</a>.</p> - -<p>Another FAQ section describes <a href="#pmtu.broken">MTU problems</a>. -These are a possibility for some interfaces.</p> - -<h3><a name="vlan">Will FreeS/WAN work on a VLAN (802.1q) network?</a></h3> - -<p> - Yes, FreeSwan works fine, though some network drivers have problems - with jumbo sized ethernet frames. If you used interfaces=%defaultroute - you do not need to change anything, but if you specified an interface - (eg eth0) then remember you must change that to reflect the VLAN - interface (eg eth0.2 for VLAN ID 2). -</p> -<p> - The "eepro100" module is known to be broken, use the e100 driver - for those cards instead (included in 2.4 as 'alternative driver' for - the Intel EtherExpressPro/100. -</p> -<p> - You do not need to change any MTU setting (those are workarounds - that are only needed for buggy drivers) -</p> - -<p><em>This FAQ contributed by Paul Wouters.</em></p> - -<h2><a name="features.faq">Does FreeS/WAN support ...</a></h2> - -<p>For a discussion of which parts of the IPsec specifications FreeS/WAN does -and does not implement, see our <a href="compat.html#spec">compatibility</a> -document.</p> - -<p>For information on some often-requested features, see below.</p> - -<h3><a name="VPN.faq"></a>Does FreeS/WAN support site-to-site VPN -(<A HREF="glossary.html#VPN">Virtual Private Network</A>) -applications?</h3> - -<p>Absolutely. See this FreeS/WAN-FreeS/WAN -<A HREF="config.html">configuration example</A>. -If only one site is using FreeS/WAN, there may be a relevant HOWTO on our -<A HREF="interop.html">interop page</A>. -</p> - -<h3><a name="warrior.faq">Does FreeS/WAN support remote users connecting to a -LAN?</a></h3> - -<p>Yes. We call the remote users "Road Warriors". Check out our -FreeS/WAN-FreeS/WAN -<A HREF="config.html#config.rw">Road Warrior Configuration Example</A>.</P> - -<p>If your Road Warrior is a Windows or Mac PC, you may need to -install an IPsec implementation on that machine. -Our <A HREF="interop.html">interop</A> page lists many available brands, -and features links to several HOWTOs. - - -<h3><a name="road.shared.possible">Does FreeS/WAN support remote users using -shared secret authentication?</a></h3> - -<p><strong>Yes, but</strong> there are severe restrictions, so <strong>we -strongly recommend using </strong><a -href="glossary.html#RSA"><strong>RSA</strong></a><strong> keys for -</strong> <a -href="glossary.html#authentication"><strong>authentication</strong></a> -<strong> -instead</strong>.</p> - -<p>See this <a href="#road.PSK">FAQ question</a>.</p> - -<h3><a name="wireless.faq">Does FreeS/WAN support wireless networks?</a></h3> - -<p>Yes, it is a common practice to use IPsec over wireless networks because -their built-in encryption, <a href="glossary.html#WEP">WEP</a>, is -insecure.</p> - -<p>There is some <a href="adv_config.html#wireless.config">discussion</a> in -our advanced configuration document. See also the -<A HREF="http://www.wavesec.org">WaveSEC site</A>.</p> - -<h3><a name="PKIcert">Does FreeS/WAN support X.509 or other PKI -certificates?</a></h3> - -<P>Vanilla FreeS/WAN does not support X.509, but Andreas Steffen -and others have provided a popular, well-supported X.509 patch.</P> - -<UL> -<LI><A HREF="http://www.strongsec.com/freeswan">patch</A> -</LI> -<LI><A HREF="http://www.freeswan.ca">Super FreeS/WAN</A> incorporates -this and other user-contributed patches. -</LI> -<LI> -Kai Martius' <A HREF="http://www.strongsec.com/freeswan/install.htm">X.509 -Installation and Configuration Guide</A> -</LI> -</UL> - -<P> -Linux FreeS/WAN features -<A HREF="quickstart.html">Opportunistic Encryption</A>, an alternative -Public Key Infrastructure based on Secure DNS. -</P> - -<h3><a name="Radius">Does FreeS/WAN support user authentication (Radius, -SecureID, Smart Card...)?</a></h3> - -<P>Andreas Steffen's <A HREF="http://www.strongsec.com/freeswan">X.509 patch</A> (v. 1.42+) supports Smart Cards. The patch -does not ship with vanilla FreeS/WAN, but will be incorporated into -<A HREF="http://www.freeswan.ca/">Super FreeS/WAN -2.01+</A>. The patch implements the PCKS#15 -Cryptographic Token Information Format Standard, using the OpenSC smartcard -library functions.</P> - -<P>Older news:</P> - -<P>A user-supported patch to FreeS/WAN 1.3, for smart card style -authentication, is available on -<A HREF="http://alcatraz.webcriminals.com/~bastiaan/ipsec">Bastiaan's site</A>. -It supports skeyid and ibutton. -This patch is not part of Super FreeS/WAN.</p> - -<p>For a while progress on this front was impeded by a lack of standard. -The IETF <a -href="http://www.ietf.org/html.charters/ipsra-charter.html">working group</a> -has now nearly completed its recommended solution to the problem; meanwhile -several vendors have implemented various things.</p> - -<!-- -<p>The <a href="web.html#patch">patches</a> section of our web links document -has links to some user work on this.</p> ---> - -<p>Of course, there are various ways to avoid any requirement for user -authentication in IPsec. Consider the situation where road warriors build -IPsec tunnels to your office net and you are considering requiring user -authentication during tunnel negotiation. Alternatives include:</p> -<ul> - <li>If you can trust the road warrior machines, then set them up so that - only authorised users can create tunnels. If your road warriors use - laptops, consider the possibility of theft.</li> - <li>If the tunnel only provides access to particular servers and you can - trust those servers, then set the servers up to require user - authentication.</li> -</ul> - -<p>If either of those is trustworthy, it is not clear that you need user -authentication in IPsec.</p> - - -<h3><a name="NATtraversal">Does FreeS/WAN support NAT traversal?</a></h3> - -<p>Vanilla FreeS/WAN does not, but thanks to Mathieu Lafon and -Arkoon Network Security, there's a patch to support this.</P> - -<UL> -<LI><A HREF="http://open-source.arkoon.net">patch and documentation</A> -</LI> -<LI><A HREF="http://www.freeswan.ca">Super FreeS/WAN</A> incorporates -this and other user-contributed patches. -</LI> -</UL> - -<P>The NAT traversal patch has some issues with PSKs, so you may wish to -authenticate with RSA keys, or X.509 (requires a patch which is also -included in Super FreeS/WAN). Doing the latter also has -advantages when dealing with large numbers of clients who may be behind NAT; -instead of having to make an individual Roadwarrior connection for each -virtual IP, you can use the "rightsubnetwithin" parameter to specify a range. -See -<A HREF="http://www.strongsec.com/freeswan/install.htm#section_4.4">these -<VAR>rightsubnetwithin</VAR> instructions</A>. -</P> - - -<h3><a name="virtID">Does FreeS/WAN support assigning a "virtual identity" to -a remote system?</a></h3> - -<p>Some IPsec implementations allow you to make the source address on packets -sent by a Road Warrior machine be something other than the address of its -interface to the Internet. This is sometimes described as assigning a virtual -identity to that machine.</p> - -<p>FreeS/WAN does not directly support this, but it can be done. See this <a -href="#road.masq">FAQ question</a>.</p> - -<h3><a name="noDES.faq">Does FreeS/WAN support single DES encryption?</a></h3> - -<p><strong>No</strong>, single DES is not used either at the <a -href="glossary.html#IKE">IKE</a> level for negotiating connections or at the -<a href="glossary.html#IPsec">IPsec</a> level for actually building them.</p> - -<p>Single DES is <a href="politics.html#desnotsecure">insecure</a>. As we see -it, it is more important to deliver real security than to comply with a -standard which has been subverted into allowing use of inadequate methods. -See this <a href="politics.html#weak">discussion</a>.</p> - -<p>If you want to interoperate with an IPsec implementation which offers only -DES, see our <a href="interop.html#noDES">interoperation</a> document.</p> - -<h3><a name="AES.faq">Does FreeS/WAN support AES encryption?</a></h3> - -<p><a href="glossary.html#AES">AES</a> is a new US government <a -href="glossary.html#block">block cipher</a> standard to replace the obsolete -<a href="glossary.html#DES">DES</a>.</p> - -<p>At time of writing (March 2002), the FreeS/WAN distribution does not yet -support AES but user-written <a href="web.html#patch">patches</a> are -available to add it. Our kernel programmer is working on integrating those -patches into the distribution, and there is active discussion of this on the -design mailimg list.</p> - -<h3><a name="other.cipher">Does FreeS/WAN support other encryption -algorithms?</a></h3> - -<p>Currently <a href="glossary.html#3DES">triple DES</a> is the only cipher -supported. AES will almost certainly be added (see previous question), and it -is likely that in the process we will also add the other two AES finalists -with open licensing, Twofish and Serpent.</p> - -<p>We are extremely reluctant to add other ciphers. This would make both use -and maintenance of FreeS/WAN more complex without providing any clear -benefit. Complexity is emphatically not desirable in a security product.</p> - -<p>Various users have written patches to add other ciphers. We provide <a -href="web.html#patch">links</a> to these.</p> - -<h2><a name="canI">Can I ...</a></h2> - - -<h3><a name="policy.preconfig">Can I use policy groups along with -explicitly configured connections?</a></h3> - -<p>Yes, you can, so long as you pay attention to the selection rule, -which can be summarized "the most specific -connection wins". We describe the rule in our -<A HREF="policygroups.html#policy.group.notes">policy groups</A> document, -and provide a more technical explanation in -<A HREF="manpage.d/ipsec.conf.5.html">man ipsec.conf</A>. -</p> - -<p>A good guideline: If you have a regular connection defined in -<VAR>ipsec.conf</VAR>, ensure that a subset of that connection -is not listed in a less restrictive policy group. Otherwise, -FreeS/WAN will use the subset, with its more specific source/destination -pair.</p> - -<p>Here's an example. Suppose you are the system administrator at 192.0.2.2. -You have this connection in ipsec.conf: -<VAR>ipsec.conf</VAR>: - -<PRE>conn net-to-net - left=192.0.2.2 # you are here - right=192.0.2.8 - rightsubnet=192.0.2.96/27 - .... -</PRE> - -<p>If you then place a host or net within <VAR>rightsubnet</VAR>, -(let's say 192.0.2.98) in <VAR>private-or-clear</VAR>, you may find -that 192.0.2.2 at times communicates in the -clear with 192.0.2.98. That's consistent with the rule, but may be -contrary to your expectations.</p> - -<p>On the other hand, it's safe to put a larger subnet in a less -restrictive policy group file. If <VAR>private-or-clear</VAR> -contains 192.0.2.0/24, then the more specific <VAR>net-to-net</VAR> -connection is used for any communication to 192.0.2.96/27. The -more general policy applies only to communication with hosts or subnets in -192.0.2.0/24 without a more specific policy or connection.</p> - - -<h3><a name="policy.off">Can I turn off policy groups?</a></h3> - -<p>Yes. Use <A HREF="policygroups.html#disable_policygroups">these -instructions</A>.</p> - -<!-- -<h3><a name="policy.otherinterface">Can I use policy groups - on an interface other than <VAR>%defaultroute</VAR>?</a></h3> - -<p>??<p> ---> - -<h3><a name="reload">Can I reload connection info without restarting?</a></h3> - -<p>Yes, you can do this. Here are the details, in a mailing list message from -Pluto programmer Hugh Redelmeier:</p> -<pre>| How can I reload config's without restarting all of pluto and klips? I am using -| FreeSWAN -> PGPNet in a medium sized production environment, and would like to be -| able to add new connections ( i am using include config/* ) without dropping current -| SA's. -| -| Can this be done? -| -| If not, are there plans to add this kind of feature? - - ipsec auto --add whatever -This will look in the usual place (/etc/ipsec.conf) for a conn named -whatever and add it. - -If you added new secrets, you need to do - ipsec auto --rereadsecrets -before Pluto needs to know those secrets. - -| I have looked (perhaps not thoroughly enough tho) to see how to do this: - -There may be more bits to look for, depending on what you are trying -to do.</pre> - -<p>Another useful command here is <var>ipsec auto --replace -<conn_name></var> which re-reads data for a named connection.</p> - -<h3><a name="masq.faq">Can I use several masqueraded subnets?</a></h3> - -<p>Yes. This is done all the time. See the discussion in our <a -href="config.html#route_or_not">setup</a> document. The only restriction is -that the subnets on the two ends must not overlap. See the next question.</p> - -<p>Here is a mailing list message on the topic. The user incorrectly thinks -you need a 2.4 kernel for this -- actually various people have been doing it -on 2.0 and 2.2 for quite some time -- but he has it right for 2.4.</p> -<pre>Subject: Double NAT and freeswan working :) - Date: Sun, 11 Mar 2001 - From: Paul Wouters <paul@xtdnet.nl> - -Just to share my pleasure, and make an entry for people who are searching -the net on how to do this. Here's the very simple solution to have a double -NAT'ed network working with freeswan. (Not sure if this is old news, but I'm -not on the list (too much spam) and I didn't read this in any HOWTO/FAQ/doc -on the freeswan site yet (Sandy, put it in! :) - -10.0.0.0/24 --- 10.0.0.1 a.b.c.d ---- a.b.c.e {internet} ----+ - | -10.0.1.0/24 --- 10.0.1.1 f.g.h.i ---- f.g.h.j {internet} ----+ - -the goal is to have the first network do a VPN to the second one, yet also -have NAT in place for connections not destinated for the other side of the -NAT. Here the two Linux security gateways have one real IP number (cable -modem, dialup, whatever. - -The problem with NAT is you don't want packets from 10.*.*.* to 10.*.*.* -to be NAT'ed. While with Linux 2.2, you can't, with Linux 2.4 you can. - -(This has been tested and works for 2.4.2 with Freeswan snapshot2001mar8b) - -relevant parts of /etc/ipsec.conf: - - left=f.g.h.i - leftsubnet=10.0.1.0/24 - leftnexthop=f.g.h.j - leftfirewall=yes - leftid=@firewall.netone.nl - leftrsasigkey=0x0........ - right=a.b.c.d - rightsubnet=10.0.0.0/24 - rightnexthop=a.b.c.e - rightfirewall=yes - rightid=@firewall.nettwo.nl - rightrsasigkey=0x0...... - # To authorize this connection, but not actually start it, at startup, - # uncomment this. - auto=add - -and now the real trick. Setup the NAT correctly on both sites: - -iptables -t nat -F -iptables -t nat -A POSTROUTING -o eth0 -d \! 10.0.0.0/8 -j MASQUERADE - -This tells the NAT code to only do NAT for packets with destination other then -10.* networks. note the backslash to mask the exclamation mark to protect it -against the shell. - -Happy painting :) - -Paul</pre> - -<h3><a name="dup_route">Can I use subnets masqueraded to the same -addresses?</a></h3> - -<p><strong>No.</strong> The notion that IP addresses are unique is one of the -fundamental principles of the IP protocol. Messing with it is exceedingly -perilous.</p> - -<p>Fairly often a situation comes up where a company has several branches, -all using the same <a href="glossary.html#non-routable">non-routable -addresses</a>, perhaps 192.168.0.0/24. This works fine as long as those nets -are kept distinct. The <a href="glossary.html#masq">IP masquerading</a> on -their firewalls ensures that packets reaching the Internet carry the firewall -address, not the private address.</p> - -<p>This can break down when IPsec enters the picture. FreeS/WAN builds a -tunnel that pokes through both masquerades and delivers packets from -<var>leftsubnet</var> to <var>rightsubnet</var> and vice versa. For this to -work, the two subnets <em>must</em> be distinct.</p> - -<p>There are several solutions to this problem.</p> - -<p>Usually, you <strong>re-number the subnets</strong>. Perhaps the Vancouver -office becomes 192.168.101.0/24, Calgary 192.168.102.0/24 and so on. -FreeS/WAN can happily handle this. With, for example -<var>leftsubnet=192.168.101.0/24</var> and -<var>rightsubnet=192.168.102.0/24</var> in a connection description, any -machine in Calgary can talk to any machine in Vancouver. If you want to be -more restrictive and use something like -<var>leftsubnet=192.168.101.128/25</var> and -<var>rightsubnet=192.168.102.240/28</var> so only certain machines on each -end have access to the tunnel, that's fine too.</p> - -<p>You could also <strong>split the subnet</strong> into smaller ones, for -example using <var>192.168.1.0/25</var> in Vancouver and -<var>rightsubnet=192.168.0.128/25</var> in Calgary.</p> - -<p>Alternately, you can just <strong>give up routing</strong> directly to -machines on the subnets. Omit the <var>leftsubnet</var> and -<var>rightsubnet</var> parameters from your connection descriptions. Your -IPsec tunnels will then run between the public interfaces of the two -firewalls. Packets will be masqueraded both before they are put into tunnels -and after they emerge. Your Vancouver client machines will see only one -Calgary machine, the firewall.</p> - -<h3><a name="road.masq">Can I assign a road warrior an address on my net (a -virtual identity)?</a></h3> - -<p>Often it would be convenient to be able to give a Road Warrior an IP -address which appears to be on the local network. Some IPsec implementations -have support for this, sometimes calling the feature "virtual identity".</p> - -<p>Currently (Sept 2002) FreeS/WAN does not support this, and we have -no definite plans to add it. The difficulty is that is not yet a standard -mechanism for it. There is an Internet Draft for a method of doing it using -<a href="#DHCP">DHCP</a> which looks promising. FreeS/WAN may support that in -a future release.</p> - -<p>In the meanwhile, you can do it yourself using the Linux iproute2(8) -facilities. Details are in <a -href="http://www.av8n.com/vpn/iproute2.htm">this -paper</a>.</p> - -<p>Another method has also been discussed on the mailing list.:</p> -<ul> - <li>You can use a variant of the <a - href="adv_config.html#extruded.config">extruded subnet</a> procedure.</li> - <li>You have to avoid having the road warrior's assigned address within the - range you actually use at home base. See previous question.</li> - <li>On the other hand, you want the roadwarrior's address to be within the - range that <em>seems</em> to be on your network.</li> -</ul> - -<p>For example, you might have:</p> -<dl> - <dt>leftsubnet=a.b.c.0/25</dt> - <dd>head office network</dd> - <dt>rightsubnet=a.b.c.129/32</dt> - <dd>extruded to a road warrior. Note that this is not in a.b.c.0/25</dd> - <dt>a.b.c.0/24</dt> - <dd>whole network, including both the above</dd> -</dl> - -<p>You then set up routing so that the office machines use the IPsec gateway -as their route to a.b.c.128/25. The leftsubnet parameter tells the road -warriors to use tunnels to reach a.b.c.0/25, so you should have two-way -communication. Depending or your network and applications, there may be some -additional work to do on DNS or Windows configuration</p> - -<h3><a name="road.many">Can I support many road warriors with one -gateway?</a></h3> - -<p>Yes. This is easily done, using</p> -<dl> - <dt>either RSA authentication</dt> - <dd>standard in the FreeS/WAN distribution</dd> - <dt>or X.509 certificates</dt> - <dd>requires <a href="#PKIcert">Super FreeS/WAN or a patch</a>.</dd> -</dl> - -<p>In either case, each Road Warrior must have a different key or -certificate.</p> - -<p>It is also possible using pre-shared key authentication, -though we don't recommend this; see the -<a href="#road.PSK">next question</a> for details.</p> - -<p>If you expect to have more than a few dozen Road Warriors connecting -simultaneously, you may need a fairly powerful gateway machine. See our -document on <a href="performance.html">FreeS/WAN performance</a>.</p> - -<h3><a name="road.PSK">Can I have many road warriors using shared secret -authentication?</a></h3> - -<p><STRONG>Yes, but avoid it if possible</STRONG>.</p> - -<p>You can have multiple Road Warriors using shared secret authentication -<strong>only if they all use the same secret</strong>. You must also -set:<p> - -<PRE> uniqueids=no </PRE> - -<p>in the connection definition.</p> - - -<p>Why it's less secure:</p> -<ul> - <li>If you have many users, it becomes almost certain the secret will - leak</li> - <li>The secret becomes quite valuable to an attacker</li> - <li>All users authenticate the same way, so the gateway cannot tell them - apart for logging or access control purposes</li> - <li>Changing the secret is difficult. You have to securely notify all - users.</li> - <li>If you find out the secret has been compromised, you can change it, but - then what? None of your users can connect without the new secret. How - will you notify them all, quickly and securely, without using the - VPN?</li> -</ul> - -<p>This is a designed-in limitation of the <a -href="glossary.html#IKE">IKE</a> key negotiation protocol, not a problem with -our implementation.</p> - -<p><strong>We very strongly recommend that you avoid using shared secret -authentication for multiple Road Warriors.</strong> Use RSA authentication -instead.</p> - -<p>The longer story: When using shared secrets, the protocol requires -that the responding -gateway be able to determine which secret to use at a time when all it knows -about the initiator is an IP address. This works fine if you know the -initiator's address in advance and can use it to look up the appropiriate -secret. However, it fails for Road Warriors since the gateway cannot know -their IP addresses in advance.</p> - -<p>With RSA signatures (or certificates) the protocol is slightly different. -The initiator provides an identifier early in the exchange and the responder -can use that identifier to look up the correct key or certificate. See <a -href="#road.many">above</a>.</p> - -<h3><a name="QoS">Can I use Quality of Service routing with -FreeS/WAN?</a></h3> - -<p>From project technical lead Henry Spencer:</p> -<pre>> Do QoS add to FreeS/WAN? -> For example integrating DiffServ and FreeS/WAN? - -With a current version of FreeS/WAN, you will have to add hidetos=no to -the config-setup section of your configuration file. By default, the TOS -field of tunnel packets is zeroed; with hidetos=no, it is copied from the -packet inside. (This is a modest security hole, which is why it is no -longer the default.) - -DiffServ does not interact well with tunneling in general. Ways of -improving this are being studied.</pre> - -<p>Copying the <a href="glossary.html#TOS">TOS</a> (type of service) -information from the encapsulated packet to the outer header reveals the TOS -information to an eavesdropper. This does not tell him much, but it might be -of use in <a href="glossary.html#traffic">traffic analysis</a>. Since we do -not have to give it to him, our default is not to.</p> - -<P>Even with the TOS hidden, you can still:</P> -<UL> -<LI>apply QOS rules to the tunneled (ESP) packets; for example, by -giving ESP packets a certain priority.</LI> -<LI>apply QOS rules to the packets as they enter or exit the tunnel -via an IPsec virtual interface (eg. <VAR>ipsec0</VAR>).</LI> -</UL> - -<p>See <a href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a> for more on -the <var>hidetos=</var> parameter.</p> - - -<h3><a name="deadtunnel">Can I recognise dead tunnels and shut them -down?</a></h3> - -<p>There is no general mechanism to do this is in the IPsec protocols.</p> - -<p>From time to time, there is discussion on the IETF Working Group <a -href="mail.html#ietf">mailing list</a> of adding a "keep-alive" mechanism -(which some say should be called "make-dead"), but it is a fairly complex -problem and no consensus has been reached on whether or how it should be -done.</p> - -<p>The protocol does have optional <a href="#ignore">delete-SA</a> messages -which one side can send when it closes a connection in hopes this will cause -the other side to do the same. FreeS/WAN does not currently support these. In -any case, they would not solve the problem since:</p> -<ul> - <li>a gateway that crashes or hangs would not send the messages</li> - <li>the sender is not required to send them</li> - <li>they are not authenticated, so any receiver that trusts them leaves - itself open to a <a href="glossary.html#DOS">denial of service</a> - attack</li> - <li>the receiver is not required to do anything about them</li> - <li>the receiver cannot acknowledge them; the protocol provides no - mechanism for that</li> - <li>since they are not acknowledged, the sender cannot rely on them</li> -</ul> - -<p>However, connections do have limited lifetimes and you can control how -many attempts your gateway makes to rekey before giving up. For example, you -can set:</p> -<pre>conn default - keyingtries=3 - keylife=30m</pre> - -<p>With these settings old connections will be cleaned up. Within 30 minutes -of the other end dying, rekeying will be attempted. If it succeeds, the new -connection replaces the old one. If it fails, no new connection is created. -Either way, the old connection is taken down when its lifetime expires.</p> - -<p>Here is a mailing list message on the topic from FreeS/WAN tech support -person Claudia Schmeing:</p> -<pre>You ask how to determine whether a tunnel is redundant: - -> Can anybody explain the best way to determine this. Esp when a RW has -> disconnected? I thought 'ipsec auto --status' might be one way. - -If a tunnel goes down from one end, Linux FreeS/WAN on the -other end has no way of knowing this until it attempts to rekey. -Once it tries to rekey and fails, it will 'know' that the tunnel is -down. - -Because it doesn't have a way of knowing the state until this point, -it will also not be able to tell you the state via ipsec auto --status. - -> However, comparing output from a working tunnel with that of one that -> was closed -> did not show clearly show tunnel status. - -If your tunnel is down but not 'unrouted' (see man ipsec_auto), you -should not be able to ping the opposite side of the tunnel. You can -use this as an indicator of tunnel status. - -On a related note, you may be interested to know that as of 1.7, -redundant tunnels caused by RW disconnections are likely to be -less of a pain. From doc/CHANGES: - - There is a new configuration parameter, uniqueids, to control a new Pluto - option: when a new connection is negotiated with the same ID as an old - one, the old one is deleted immediately. This should help eliminate - dangling Road Warrior connections when the same Road Warrior reconnects. - It thus requires that IDs not be shared by hosts (a previously legal but - probably useless capability). NOTE WELL: the sample ipsec.conf now has - uniqueids=yes in its config-setup section. - - -Cheers, - -Claudia</pre> - -<h3><a name="demanddial">Can I build IPsec tunnels over a demand-dialed -link?</a></h3> - -<p>This is possible, but not easy. FreeS/WAN technical lead Henry Spencer -wrote:</p> -<pre>> 5. If the ISDN link goes down in between and is reestablished, the SAs -> are still up but the eroute are deleted and the IPsec interface shows -> garbage (with ifconfig) -> 6. Only restarting IPsec will bring the VPN back online. - -This one is awkward to solve. If the real interface that the IPsec -interface is mounted on goes down, it takes most of the IPsec machinery -down with it, and a restart is the only good way to recover. - -The only really clean fix, right now, is to split the machines in two: - -1. A minimal machine serves as the network router, and only it is aware -that the link goes up and down. - -2. The IPsec is done on a separate gateway machine, which thinks it has -a permanent network connection, via the router. - -This is clumsy but it does work. Trying to do both functions within a -single machine is tricky. There is a software package (diald) which will -give the illusion of a permanent connection for demand-dialed modem -connections; I don't know whether it's usable for ISDN, or whether it can -be made to cooperate properly with FreeS/WAN. - -Doing a restart each time the interface comes up *does* work, although it -is a bit painful. I did that with PPP when I was running on a modem link; -it wasn't hard to arrange the PPP scripts to bring IPsec up and down at -the right times. (I'd meant to investigate diald but never found time.) - -In principle you don't need to do a complete restart on reconnect, but you -do have to rebuild some things, and we have no nice clean way of doing -only the necessary parts.</pre> - -<p>In the same thread, one user commented:</p> -<pre>Subject: Re: linux-ipsec: IPsec and Dial Up Connections - Date: Wed, 22 Nov 2000 - From: Andy Bradford <andyb@calderasystems.com> - -On Wed, 22 Nov 2000 19:47:11 +0100, Philip Reetz wrote: - -> Are there any ideas what might be the cause of the problem and any way -> to work around it. -> Any help is highly appreciated. - -On my laptop, when using ppp there is a ip-up script in /etc/ppp that -will be executed each time that the ppp interface is brought up. -Likewise there is an ip-down script that is called when it is taken -down. You might consider custimzing those to stop and start FreeS/WAN -with each connection. I believe that ISDN uses the same files, though -I could be wrong---there should be something similar though.</pre> - -<h3><a name="GRE">Can I build GRE, L2TP or PPTP tunnels over IPsec?</a></h3> - -<p>Yes. Normally this is not necessary, but it is useful in a few special -cases. For example, if you must route non-IP packets such as IPX, you -will need to use a tunneling protocol that can route these packets. IPsec -can be layered around it for extra security. Another example: you -can provide failover protection for high availability (HA) environments by -combining IPsec with other tools. Ken Bantoft describes one such setup in -<A HREF="http://www.freeswan.ca/docs/HA">Using FreeS/WAN with Linux-HA, GRE, -OSPF and BGP for enterprise grade VPN solutions</A>.</P> - -<p>GRE over IPsec is covered as part of -<A HREF="http://www.freeswan.ca/docs/HA">that document</A>. -<a href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/07/msg00209.html"> -Here are links</a> to other GRE resources. - -Jacco de Leuw has created -<A HREF="http://www.jacco2.dds.nl/networking/">this page on L2TP over IPsec</A> -with instructions for FreeS/WAN and several other brands of IPsec software. -</P> - -<P>Please let us know of other useful links via the -<A HREF="mail.html">mailing lists</A>. - - -<h3><a name="NetBIOS">... use Network Neighborhood (Samba, NetBIOS) over IPsec?</a></h3> - -<p>Your local PC needs to know how to translate NetBIOS names to IP addresses. -It may do this either via a local LMHOSTS file, or using a local or remote -WINS server. The WINS server is preferable since it provides a centralized -source of the information to the entire network. To use a WINS server over -the <A HREF="glossary.html#VPN">VPN</A> -(or any IP-based network), you must enable "NetBIOS over TCP".</p> - -<p><A HREF="http://www.samba.org">Samba</A> can emulate a WINS server -on Linux.</p> - -<p> -See also several discussions in our -<A HREF="http://lists.freeswan.org/pipermail/users/2002-September/thread.html">September -2002 Users archives</A></p> - - -<h2><a name="setup.faq">Life's little mysteries</a></h2> - -<p>FreeS/WAN is a fairly complex product. (Neither the networks it runs on -nor the protocols it uses are simple, so it could hardly be otherwise.) It -therefore sometimes exhibits behaviour which can be somewhat confusing, or -has problems which are not easy to diagnose. This section tries to explain -those problems.</p> - -<p>Setup and configuration of FreeS/WAN are covered in other documentation -sections:</p> -<ul> - <li><a href="quickstart.html">basic setup and configuration</a></li> - <li><a href="adv_config.html">advanced configuration</a></li> - <li><a href="trouble.html">Troubleshooting</a></li> -</ul> - -<p>However, we also list some of the commonest problems here.</p> - -<h3><a name="cantping">I cannot ping ....</a></h3> - -<p>This question is dealt with in the advanced configuration section under -the heading <a href="adv_config.html#multitunnel">multiple tunnels</a>.</p> - -<p>The standard subnet-to-subnet tunnel protects traffic <strong>only between -the subnets</strong>. To test it, you must use pings that go from one subnet -to the other.</p> - -<p>For example, suppose you have:</p> -<pre> subnet a.b.c.0/24 - | - eth1 = a.b.c.1 - gate1 - eth0 = 192.0.2.8 - | - - ~ internet ~ - - | - eth0 = 192.0.2.11 - gate2 - eth1 = x.y.z.1 - | - subnet x.y.z.0/24</pre> - -<p>and the connection description:</p> -<pre>conn abc-xyz - left=192.0.2.8 - leftsubnet=a.b.c.0/24 - right=192.0.2.11 - rightsubnet=x.y.z.0/24</pre> - -<p>You can test this connection description only by sending a ping that will -actually go through the tunnel. Assuming you have machines at addresses -a.b.c.2 and x.y.z.2, pings you might consider trying are:</p> -<dl> - <dt>ping from x.y.z.2 to a.b.c.2 or vice versa</dt> - <dd>Succeeds if tunnel is working. This is the <strong>only valid test of - the tunnel</strong>.</dd> - <dt>ping from gate2 to a.b.c.2 or vice versa</dt> - <dd><strong>Does not use tunnel</strong>. gate2 is not on protected - subnet.</dd> - <dt>ping from gate1 to x.y.z.2 or vice versa</dt> - <dd><strong>Does not use tunnel</strong>. gate1 is not on protected - subnet.</dd> - <dt>ping from gate1 to gate2 or vice versa</dt> - <dd><strong>Does not use tunnel</strong>. Neither gate is on a protected - subnet.</dd> -</dl> - -<p>Only the first of these is a useful test of this tunnel. The others do not -use the tunnel. Depending on other details of your setup and routing, -they:</p> -<ul> - <li>either fail, telling you nothing about the tunnel</li> - <li>or succeed, telling you nothing about the tunnel since these packets - use some other route</li> -</ul> - -<p>In some cases, you may be able to get around this. For the example network -above, you could use:</p> -<pre> ping -I a.b.c.1 x.y.z.1</pre> - -<p>Both the adresses given are within protected subnets, so this should go -through the tunnel.</p> - -<p>If required, you can build additional tunnels so that all the machines -involved can talk to all the others. See <a -href="adv_config.html#multitunnel">multiple tunnels</a> in the advanced -configuration document for details.</p> - -<h3><a name="forever">It takes forever to ...</a></h3> - -<p>Users fairly often report various problems involving long delays, -sometimes on tunnel setup and sometimes on operations done through the -tunnel, occasionally on simple things like ping or more often on more complex -operations like doing NFS or Samba through the tunnel.</p> - -<p>Almost always, these turn out to involve failure of a DNS lookup. The -timeouts waiting for DNS are typically set long so that you won't time out -when a query involves multiple lookups or long paths. Genuine failures -therefore produce long delays before they are detected.</p> - -<p>A mailing list message from project technical lead Henry Spencer:</p> -<pre>> ... when i run /etc/rc.d/init.d/ipsec start, i get: -> ipsec_setup: Starting FreeS/WAN IPsec 1.5... -> and it just sits there, doesn't give back my bash prompt. - -Almost certainly, the problem is that you're using DNS names in your -ipsec.conf, but DNS lookups are not working for some reason. You will -get your prompt back... eventually. But the DNS timeouts are long. -Doing something about this is on our list, but it is not easy.</pre> - -<p>In the meanwhile, we recommend that connection descriptions in <a -href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a> use numeric IP addresses -rather than names which will require a DNS lookup.</p> - -<p>Names that do not require a lookup are fine. For example:</p> -<ul> - <li>a road warrior might use the identity - <var>rightid=@lancelot.example.org</var></li> - <li>the gateway might use <var>leftid=@camelot.example.org</var></li> -</ul> - -<p>These are fine. The @ sign prevents any DNS lookup. However, do not -attempt to give the gateway address as <var>left=camelot.example.org</var>. -That requires a lookup.</p> - -<p>A post from one user after solving a problem with long delays:</p> -<pre>Subject: Final Answer to Delay!!! - Date: Mon, 19 Feb 2001 - From: "Felippe Solutions" <felippe@solutionstecnologia.com.br> - -Sorry people, but seems like the Delay problem had nothing to do with -freeswan. - -The problem was DNS as some people sad from the beginning, but not the way -they thought it was happening. Samba, ssh, telnet and other apps try to -reverse lookup addresses when you use IP numbers (Stupid that ahh). - -I could ping very fast because I always ping with "-n" option, but I don't -know the option on the other apps to stop reverse addressing so I don't use -it.</pre> - -<p>This post is fairly typical. These problems are often tricky and -frustrating to diagnose, and most turn out to be DNS-related.</p> - -<p>One suggestion for diagnosis: test with both names and addresses if -possible. For example, try all of:</p> -<ul> - <li>ping <var>address</var></li> - <li>ping -n <var>address</var></li> - <li>ping <var>name</var></li> -</ul> - -<p>If these behave differently, the problem must be DNS-related since the -three commands do exactly the same thing except for DNS lookups.</p> - -<h3><a name="route">I send packets to the tunnel with route(8) but they -vanish</a></h3> - -<p>IPsec connections are designed to carry only packets travelling between -pre-defined connection endpoints. As project technical lead Henry Spencer put -it:</p> - -<blockquote> - IPsec tunnels are not just virtual wires; they are virtual wires with - built-in access controls. Negotiation of an IPsec tunnel includes - negotiation of access rights for it, which don't include packets to/from - other IP addresses. (The protocols themselves are quite inflexible about - this, so there are limits to what we can do about it.)</blockquote> - -<p>For fairly obvious security reasons, and to comply with the IPsec RFCs, <a -href="glossary.html#KLIPS">KLIPS</a> drops any packets it receives that are -not allowed on the tunnels currently defined. So if you send it packets with -<var>route(8)</var>, and suitable tunnels are not defined, the packets -vanish. Whether this is reported in the logs depends on the setting of -<var>klipsdebug</var> in your <a -href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a> file.</p> - -<p>To rescue vanishing packets, you must ensure that suitable tunnels for -them exist, by editing the connection descriptions in <a -href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a>. For example, supposing -you have a simple setup:</p> -<pre> leftsubnet -- leftgateway === internet === roadwarrior</pre> - -<p>If you want to give the roadwarrior access to some resource that is -located behind the left gateway but is not in the currently defined left -subnet, then the usual procedure is to define an additional tunnel for those -packets by creating a new connection description.</p> - -<p>In some cases, it may be easier to alter an existing connection -description, enlarging the definition of <var>leftsubnet</var>. For example, -instead of two connection descriptions with 192.168.8.0/24 and 192.168.9.0/24 -as their <var>leftsubnet</var> parameters, you can use a single description -with 192.168.8.0/23.</p> - -<p>If you have multiple endpoints on each side, you need to ensure that there -is a route for each pair of endpoints. See this <a -href="adv_config.html#multitunnel">example</a>.</p> - -<h3><a name="down_route">When a tunnel goes down, packets vanish</a></h3> - -<p>This is a special case of the vanishing packet problem described in the -previous question. Whenever KLIPS sees packets for which it does not have a -tunnel, it drops them.</p> - -<p>When a tunnel goes away, either because negotiations with the other -gateway failed or because you gave an <var>ipsec auto --down</var> command, -the route to its other end is left pointing into KLIPS, and KLIPS will drop -packets it has no tunnel for.</p> - -<p>This is a documented design decision, not a bug. FreeS/WAN must not -automatically adjust things to send packets via another route. The other -route might be insecure.</p> - -<p>Of course, re-routing may be necessary in many cases. In those cases, you -have to do it manually or via scripts. We provide the <var>ipsec auto ---unroute</var> command for these cases.</p> - -<p>From <a href="manpage.d/ipsec_auto.8.html">ipsec_auto(8)</a>:</p> - -<blockquote> - Normally, pluto establishes a route to the destination specified for a - connection as part of the --up operation. However, the route and only - the route can be established with the --route operation. Until and unless - an actual connection is established, this discards any packets sent - there, which may be preferable to having them sent elsewhere based on a - more general route (e.g., a default route).</blockquote> - -<blockquote> - Normally, pluto's route to a destination remains in place when a --down - operation is used to take the connection down (or if connection setup, or - later automatic rekeying, fails). This permits establishing a new - connection (perhaps using a different specification; the route is altered - as necessary) without having a ``window'' in which packets might go - elsewhere based on a more general route. Such a route can be removed - using the --unroute operation (and is implicitly removed by ---delete).</blockquote> - -<p>See also this mailing list <a -href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/11/msg00523.html">message</a>.</p> - -<h3><a name="firewall_ate">The firewall ate my packets!</a></h3> - -<p>If firewalls filter out:</p> -<ul> - <li>either the UDP port 500 packets used in IKE negotiations</li> - <li>or the ESP and AH (protocols 50 and 51) packets used to implement the - IPsec tunnel</li> -</ul> - -<p>then IPsec cannot work. The first thing to check if packets seem to be -vanishing is the firewall rules on the two gateway machines and any other -machines along the path that you have access to.</p> - -<p>For details, see our document on <a href="firewall.html">firewalls</a>.</p> - -<p>Some advice from technical lead Henry Spencer on diagnosing such -problems:</p> -<pre>> > Packets vanishing between the hardware interface and the ipsecN interface -> > is usually the result of firewalls not being configured to let them in... -> -> Thanks for the suggestion. If only it were that simple! My ipchains startup -> script does take care of that, but just in case I manually inserted rules -> accepting everything from london on dublin. No difference. - -The other thing to check is whether the "RX packets dropped" count on the -ipsecN interface (run "ifconfig ipsecN", for N=1 or whatever, to see the -counts) is rising. If so, then there's some sort of configuration mismatch -between the two ends, and IPsec itself is rejecting them. If none of the -ipsecN counts is rising, then the packets are never reaching the IPsec -machinery, and the problem is almost certainly in firewalls etc.</pre> - -<h3><a name="dropconn">Dropped connections</a></h3> - -<p>Networks being what they are, IPsec connections can be broken for any -number of reasons, ranging from hardware failures to various software -problems such as the path MTU problems discussed <a -href="#pmtu.broken">elsewhere in the FAQ</a>. Fortunately, various diagnostic -tools exist that help you sort out many of the possible problems.</p> - -<p>There is one situation, however, where FreeS/WAN (using default settings) -may destroy a connection for no readily apparent reason. This occurs when -things are <strong>misconfigured</strong> so that <strong>two -tunnels</strong> from the same gateway expect <strong>the same subnet on the -far end</strong>.</p> - -<p>In this situation, the first tunnel comes up fine and works until the -second is established. At that point, because of the way we track connections -internally, the first tunnel ceases to exist as far as this gateway is -concerned. Of course the far end does not know that, and a storm of error -messages appears on both systems as it tries to use the tunnel.</p> - -<p>If the far end gives up, goes back to square one and negotiates a new -tunnel, then that wipes out the second tunnel and ...</p> - -<p>The solution is simple. <strong>Do not build multiple conn descriptions -with the same remote subnet</strong>.</p> - -<p>This is actually intended to be a feature, rather than a bug. Consider the -situation where a single remote system goes down, then comes back up and -reconnects to the gateway. It is useful to have the gateway tear down the old -tunnel and recover resources when the reconnection is made. It recognises -that situation by checking the remote subnet for each tunnel it builds and -discarding duplicates. This works fine as long as you don't configure -multiple tunnels with the same remote subnet.</p> - -<p>If this behaviour is inconvenient for you, you can disable it by setting -<var>uniqueids=no</var> in <a -href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a>.</p> - - -<h3><a name="defaultroutegone">Disappearing %defaultroute</a></h3> - -<p>When an underlying connection (eg. ppp) goes down, FreeS/WAN will not -recover properly without a little help. Here are the symptoms that FreeS/WAN -user Michael Carmody noticed: -<pre> -> After about 24 hours the freeswan connection takes over the default route. -> -> i.e instead of deafult gateway pointing to the router via eth0, it becomes a -> pointer to the router via ipsec0. - -> All internet access is then lost as all replies (and not just the link I -> wanted) are routed out ipsec0 and the router doesn't respond to the ipsec -> traffic. -</pre> - -<p>If you're using a -FreeS/WAN 2.x/KLIPS system, simply re-attach the IPsec virtual -interface with <em>ipsec tnconfig</em> command such as:</p> -<pre> ipsec tnconfig --attach --virtual ipsec0 --physical ppp0</pre> -<p>In your command, name the physical and virtual interfaces as they -appear paired on your system during regular uptime. For a system with several -physical/virtual interface pairs on flaky links, you'll need more than -one such command. -If you're using FreeS/WAN 1.x, you must restart FreeS/WAN, which is more time -consuming.</p> - -<p> -<A href="http://lists.freeswan.org/pipermail/design/2002-July/003070.html">Here</A> -is a script which can help to automate the process of FreeS/WAN restart at -need. -It could easily be adapted to use tnconfig instead.</p> - -<h3><a name="tcpdump.faq">TCPdump on the gateway shows strange things</a></h3> - -As another user pointed out, keeping the connect -<p>Attempting to look at IPsec packets by running monitoring tools on the -IPsec gateway machine can produce silly results. That machine is mangling the -packets for IPsec, and possibly for firewall or NAT purposes as well. If the -internals of the machine's IP stack are not what the monitoring tool expects, -then the tool can misinterpret them and produce nonsense output.</p> - -<p>See our <a href="testing.html#tcpdump.test">testing</a> document for more -detail.</p> - -<h3><a name="no_trace">Traceroute does not show anything between the -gateways</a></h3> - -<p>As far as traceroute can see, the two gateways are one hop apart; the data -packet goes directly from one to the other through the tunnel. Of course the -outer packets that implement the tunnel pass through whatever lies between -the gateways, but those packets are built and dismantled by the gateways. -Traceroute does not see them and cannot report anything about their path.</p> - -<p>Here is a mailing list message with more detail.</p> -<pre>Date: Mon, 14 May 2001 -To: linux-ipsec@freeswan.org -From: "John S. Denker" <jsd@research.att.com< -Subject: Re: traceroute: one virtual hop - -At 02:20 PM 5/14/01 -0400, Claudia Schmeing wrote: -> ->> > A bonus question: traceroute in subnet to subnet enviroment looks like: ->> > ->> > traceroute to andris.dmz (172.20.24.10), 30 hops max, 38 byte packets ->> > 1 drama (172.20.1.1) 0.716 ms 0.942 ms 0.434 ms ->> > 2 * * * ->> > 3 andris.dmz (172.20.24.10) 73.576 ms 78.858 ms 79.434 ms ->> > ->> > Why aren't there the other hosts which take part in the delivery during -> * * * ? -> ->If there is an ipsec tunnel between GateA and Gate B, this tunnel forms a ->'virtual wire'. When it is tunneled, the original packet becomes an inner ->packet, and new ESP and/or AH headers are added to create an outer packet ->around it. You can see an example of how this is done for AH at ->doc/ipsec.html#AH . For ESP it is similar. -> ->Think about the packet's path from the inner packet's perspective. ->It leaves the subnet, goes into the tunnel, and re-emerges in the second ->subnet. This perspective is also the only one available to the ->'traceroute' command when the IPSec tunnel is up. - -Claudia got this exactly right. Let me just expand on a couple of points: - -*) GateB is exactly one (virtual) hop away from GateA. This is how it -would be if there were a physically private wire from A to B. The -virtually private connection should work the same, and it does. - -*) While the information is in transit from GateA to GateB, the hop count -of the outer header (the "envelope") is being decremented. The hop count -of the inner header (the "contents" of the envelope) is not decremented and -should not be decremented. The hop count of the outer header is not -derived from and should not be derived from the hop count of the inner header. - -Indeed, even if the packets did time out in transit along the tunnel, there -would be no way for traceroute to find out what happened. Just as -information cannot leak _out_ of the tunnel to the outside, information -cannot leak _into_ the tunnel from outside, and this includes ICMP messages -from routers along the path. - -There are some cases where one might wish for information about what is -happening at the IP layer (below the tunnel layer) -- but the protocol -makes no provision for this. This raises all sorts of conceptual issues. -AFAIK nobody has ever cared enough to really figure out what _should_ -happen, let alone implement it and standardize it. - -*) I consider the "* * *" to be a slight bug. One might wish for it to be -replaced by "GateB GateB GateB". It has to do with treating host-to-subnet -traffic different from subnet-to-subnet traffic (and other gory details). -I fervently hope KLIPS2 will make this problem go away. - -*) If you want to ask questions about the link from GateA to GateB at the -IP level (below the tunnel level), you have to ssh to GateA and launch a -traceroute from there.</pre> - -<h2><a name="man4debug">Testing in stages</a></h2> - -<p>It is often useful in debugging to test things one at a time:</p> -<ul> - <li>disable IPsec entirely, for example by turning it off with - chkconfig(8), and make sure routing works</li> - <li>Once that works, try a manually keyed connection. This does not require - key negotiation between Pluto and the key daemon on the other end.</li> - <li>Once that works, try automatically keyed connections</li> - <li>Once IPsec works, add packet compression</li> - <li>Once everything seems to work, try stress tests with large transfers, - many connections, frequent re-keying, ...</li> -</ul> - -<p>FreeS/WAN releases are tested for all of these, so you can be reasonably -certain they <em>can</em> do them all. Of course, that does not mean they -<em>will</em> on the first try, especially if you have some unusual -configuration.</p> - -<p>The rest of this section gives information on diagnosing the problem when -each of the above steps fails.</p> - -<h3><a name="nomanual">Manually keyed connections don't work</a></h3> - -<p>Suspect one of:</p> -<ul> - <li>mis-configuration of IPsec system in the /etc/ipsec.conf file<br> - common errors are incorrect interface or next hop information</li> - <li>mis-configuration of manual connection in the /etc/ipsec.conf file</li> - <li>routing problems causing IPsec packets to be lost</li> - <li>bugs in KLIPS</li> - <li>mismatch between the transforms we support and those another IPsec - implementation offers.</li> -</ul> - -<h3><a name="spi_error">One manual connection works, but second one -fails</a></h3> - -<p>This is a fairly common problem when attempting to configure multiple -manually keyed connections from a single gateway.</p> - -<p>Each connection must be identified by a unique <a -href="glossary.html#SPI">SPI</a> value. For automatic connections, these -values are assigned automatically. For manual connections, you must set them -with <var>spi=</var> statements in <a -href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a>.</p> - -<p>Each manual connection must have a unique SPI value in the range 0x100 to -0x999. Two or more with the same value will fail. For details, see our doc -section <a href="adv_config.html#prodman">Using manual keying in -production</a> and the man page <a -href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a>.</p> - -<h3><a name="man_no_auto">Manual connections work, but automatic keying -doesn't</a></h3> - -<p>The most common reason for this behaviour is a firewall dropping the UDP -port 500 packets used in key negotiation.</p> - -<p>Other possibilities:</p> -<ul> - <li>mis-configuration of auto connection in the /etc/ipsec.conf file. - <p>One common configuration error is forgetting that you need - <var>auto=add</var> to load the connection description on the receiving - end so it recognises the connection when the other end asks for it.</p> - </li> - <li>error in shared secret in /etc/ipsec.secrets</li> - <li>one gateway lacks a route to the other so Pluto's UDP packets are - lost</li> - <li>bugs in Pluto</li> - <li>incompatibilities between Pluto's <a href="glossary.html#IKE">IKE</a> - implementation and the IKE at the other end of the tunnel. - <p>Some possibile problems are discussed in out <a - href="interop.html#interop.problem">interoperation</a> document.</p> - </li> -</ul> - -<h3><a name="nocomp">IPsec works, but connections using compression -fail</a></h3> - -<p>When we first added compression, we saw some problems:</p> -<ul> - <li>compatibility issues with other implementations. We followed the RFCs - and omitted some extra material that many compression libraries add by - default. Some other implementations left the extras in</li> - <li>bugs in assembler compression routines on non-Intel CPUs. The - workaround is to use C code instead of possibly problematic - assembler.</li> -</ul> - -<p>We have not seen either problem in some time (at least six months as I -write in March 2002), but if you have some unusual configuration then you may -see them.</p> - -<h3><a name="pmtu.broken">Small packets work, but large transfers -fail</a></h3> - -<p>If tests with ping(1) and a small packet size succeed, but tests or -transfers with larger packet sizes fail, suspect problems with packet -fragmentation and perhaps <a href="glossary.html#pathMTU">path MTU -discovery</a>.</p> - -<p>Our <a href="trouble.html#bigpacket">troubleshooting document</a> covers -these problems. Information on the underlying mechanism is in our <a -href="background.html#MTU.trouble">background</a> document.</p> - -<h3><a name="subsub">Subnet-to-subnet works, but tests from the gateways -don't</a></h3> - -<p>This is described under <a href="#cantping">I cannot ping...</a> above.</p> - -<h2><a name="compile.faq">Compilation problems</a></h2> - -<h3><a name="gmp.h_missing">gmp.h: No such file or directory</a></h3> - -<p>Pluto needs the GMP (<strong>G</strong>NU</p> - -<p><strong>M</strong>ulti-<strong>P</strong>recision) library for the large -integer calculations it uses in <a href="glossary.html#public">public key</a> -cryptography. This error message indicates a failure to find the library. You -must install it before Pluto will compile.</p> - -<p>The GMP library is included in most Linux distributions. Typically, there -are two RPMs, libgmp and libgmp-devel, You need to <em>install both</em>, -either from your distribution CDs or from your vendor's web site.</p> - -<p>On Debian, a mailing list message reports that the command to give is -<var>apt-get install gmp2</var>.</p> - -<p>For more information and the latest version, see the <a -href="http://www.swox.com/gmp/">GMP home page</a>.</p> - -<h3><a name="noVM">... virtual memory exhausted</a></h3> - -<p>We have had several reports of this message appearing, all on SPARC Linux. -Here is a mailing message on a solution:</p> -<pre>> ipsec_sha1.c: In function `SHA1Transform': -> ipsec_sha1.c:95: virtual memory exhausted - -I'm seeing exactly the same problem on an Ultra with 256MB ram and 500 -MB swap. Except I am compiling version 1.5 and its Red Hat 6.2. - -I can get around this by using -O instead of -O2 for the optimization -level. So it is probably a bug in the optimizer on the sparc complier. -I'll try and chase this down on the sparc lists.</pre> - -<h2><a name="error">Interpreting error messages</a></h2> - -<h3><a name="route-client">route-client (or host) exited with status -7</a></h3> - -<p>Here is a discussion of this error from FreeS/WAN "listress" (mailing list -tech support person) Claudia Schmeing. The "FAQ on the network unreachable -error" which she refers to is the next question below.</p> -<pre>> I reached the point where the two boxes (both on dial-up connections, but -> treated as static IPs by getting the IP and editing ipsec.conf after the -> connection is established) to the point where they exchange some info, but I -> get an error like "route-client command exited with status 7 \n internal -> error". -> Where can I find a description of this error? - -In general, if the FAQ doesn't cover it, you can search the mailing list -archives - I like to use -http://www.sandelman.ottawa.on.ca/linux-ipsec/ -but you can see doc/mail.html for different archive formats. - - -Your error comes from the _updown script, which performs some -routing and firewall functions to help Linux FreeS/WAN. More info -is available at doc/firewall.html and man ipsec.conf. Its routing -is integral to the health of Linux FreeS/WAN; it also provides facility -to insert custom firewall rules to be executed when you create or destroy -a connection. - -Yours is, of course, a routing error. You can be fairly sure the routing -machinery is saying "network is unreachable". There's a FAQ on the -"network is unreachable" error, but more information is available now; read on. - -If your _updown script is recent (for example if it shipped with -Linux FreeS/WAN 1.91), you will see another debugging line in your logs -that looks something like this: - -> output: /usr/local/lib/ipsec/_updown: `route add -net 128.174.253.83 -> netmask 255.255.255.255 dev ipsec0 gw 66.92.93.161' failed - -This is, of course, the system route command that exited with status 7, -(ie. failed). Man route for details. Seeing the command typed out yields -more information. If your _updown script is older, you may wish to update -it to show the command explicitly. - -Three parameters fed to the route command: net, netmask and gw [gateway] -are derived from things you've put in ipsec.conf. - -Net and netmask are derived from the peer's IP and mask. In more detail: - -You may see a routing error when routing to a client (ie. subnet), or -to a host (IPSec gateway or freestanding host; a box that does IPSec for -itself). In _updown, the "route-client" section is responsible to set up -the route for IPSec'd (usually, read 'tunneled') packets headed to a -peer subnet. Similarly, route-host routes IPSec'd packets to a peer host -or IPSec gateway. - -When routing to a 'client', net and netmask are ipsec.conf's left- or -rightsubnet (whichever is not local). Similarly, when routing to a -'host' the net is left or right. Host netmask is always /32, indicating a -single machine. - -Gw is nexthop's value. Again, the value in question is left- or rightnexthop, -whichever is local. Where left/right or left-/rightnexthop has the special -value %defaultroute (described in man ipsec.conf), gw will automagically get -the value of the next hop on the default route. - -Q: "What's a nexthop and why do I need one?" - -A: 'nexthop' is a routing kluge; its value is the next hop away - from the machine that's doing IPSec, and toward your IPSec peer. - You need it to get the processed packets out of the local system and - onto the wire. While we often route other packets through the machine - that's now doing IPSec, and are done with it, this does not suffice here. - After packets are processed with IPSec, this machine needs to know where - they go next. Of course using the 'IPSec gateway' as their routing gateway - would cause an infinite loop! [To visualize this, see the packet flow - diagram at doc/firewall.html.] To avoid this, we route packets through - the next hop down their projected path. - -Now that you know the background, consider: -1. Did you test routing between the gateways in the absence of Linux - FreeS/WAN, as recommended? You need to ensure the two machines that - will be running Linux FreeS/WAN can route to one another before trying to - make a secure connection. -2. Is there anything obviously wrong with the sense of your route command? - -Normally, this problem is caused by an incorrect local nexthop parameter. -Check out the use of %defaultroute, described in man ipsec.conf. This is -a simple way to set nexthop for most people. To figure nexthop out by hand, -traceroute in-the-clear to your IPSec peer. Nexthop is the traceroute's -first hop after your IPSec gateway.</pre> - -<h3><a name="unreachable">SIOCADDRT:Network is unreachable</a></h3> - -<p>This message is not from FreeS/WAN, but from the Linux IP stack itself. -That stack is seeing packets it has no route for, either because your routing -was broken before FreeS/WAN started or because FreeS/WAN's changes broke -it.</p> - -<p>Here is a message from Claudia suggesting ways to diagnose and fix such -problems:</p> -<pre>You write, -> I have correctly installed freeswan-1.8 on RH7.0 kernel 2.2.17, but when -> I setup a VPN connection with the other machine(RH5.2 Kernel 2.0.36 -> freeswan-1.0, it works well.) it told me that -> "SIOCADDRT:Network is unreachable"! But the network connection is no -> problem. - -Often this error is the result of a misconfiguration. - -Be sure that you can route successfully in the absence of Linux -FreeS/WAN. (You say this is no problem, so proceed to the next step.) - -Use a custom copy of the default updownscript. Do not change the route -commands, but add a diagnostic message revealing the exact text of the -route command. Is there a problem with the sense of the route command -that you can see? If so, then re-examine those ipsec.conf settings -that are being sent to the route command. - -You may wish to use the ipsec auto --route and --unroute commands to -troubleshoot the problem. See man ipsec_auto for details.</pre> - -<p>Since the above message was written, we have modified the updown script to -provide a better diagnostic for this problem. Check -<var>/var/log/messages</var>.</p> - -<p>See also the FAQ question <a href="#route-client">route-client (or host) -exited with status 7</a>.</p> - -<h3><a name="modprobe">ipsec_setup: modprobe: Can't locate module -ipsec</a></h3> - -<h3><a name="noKLIPS">ipsec_setup: Fatal error, kernel appears to lack -KLIPS</a></h3> - -<p>These messages indicate an installation failure. The kernel you are -running does not contain the <a href="glossary.html#KLIPS">KLIPS (kernel -IPsec)</a> code.</p> - -<p>Note that the "modprobe: Can't locate module ipsec" message appears even -if you are not using modules. If there is no KLIPS in your kernel, FreeS/WAN -tries to load it as a module. If that fails, you get this message.</p> - -<p>Commands you can quickly try are:</p> -<dl> - <dt><var>uname -a</var></dt> - <dd>to get details, including compilation date and time, of the currently - running kernel</dd> - <dt><var>ls /</var></dt> - <dt><var>ls /boot</var></dt> - <dd>to ensure a new kernel is where it should be. If kernel compilation - puts it in <var>/</var> but <var>lilo</var> wants it in - <var>/boot</var>, then you should uncomment the - <var>INSTALL_PATH=/boot</var> line in the kernel - <var>Makefile</var>.</dd> - <dt><var>more /etc/lilo.conf</var></dt> - <dd>to see that <var>lilo</var> has correct information</dd> - <dt><var>lilo</var></dt> - <dd>to ensure that information in <var>/etc/lilo.conf</var> has been - transferred to the boot sector</dd> -</dl> - -<p>If those don't find the problem, you have to go back and check through the -<a href="install.html">install</a> procedure to see what was missed.</p> - -<p>Here is one of Claudia's messages on the topic:</p> -<pre>> I tried to install freeswan 1.8 on my mandrake 7.2 test box. ... - -> It does show version and some output for whack. - -Yes, because the Pluto (daemon) part of ipsec is installed correctly, but -as we see below the kernel portion is not. - -> However, I get the following from /var/log/messages: -> -> Mar 11 22:11:55 pavillion ipsec_setup: Starting FreeS/WAN IPsec 1.8... -> Mar 11 22:12:02 pavillion ipsec_setup: modprobe: Can't locate module ipsec -> Mar 11 22:12:02 pavillion ipsec_setup: Fatal error, kernel appears to lack -> KLIPS. - -This is your problem. You have not successfully installed a kernel with -IPSec machinery in it. - -Did you build Linux FreeS/WAN as a module? If so, you need to ensure that -your new module has been installed in the directory where your kernel -loader normally finds your modules. If not, you need to ensure -that the new IPSec-enabled kernel is being loaded correctly. - -See also doc/install.html, and INSTALL in the distro.</pre> - -<h3><a name="noDNS">ipsec_setup: ... failure to fetch key for ... from -DNS</a></h3> - -<p>Quoting Henry:</p> -<pre>Note that by default, FreeS/WAN is now set up to - (a) authenticate with RSA keys, and - (b) fetch the public key of the far end from DNS. -Explicit attention to ipsec.conf will be needed if you want -to do something different.</pre> - -<p>and Claudia, responding to the same user:</p> -<pre>You write, - -> My current setup in ipsec.conf is leftrsasigkey=%dns I have -> commented this and authby=rsasig out. I am able to get ipsec running, -> but what I find is that the documentation only specifies for %dns are -> there any other values that can be placed in this variable other than -> %dns and the key? I am also assuming that this is where I would place -> my public key for the left and right side as well is this correct? - -Valid values for authby= are rsasig and secret, which entail authentication -by RSA signature or by shared secret, respectively. Because you have -commented authby=rsasig out, you are using the default value of authby=secret. - -When using RSA signatures, there are two ways to get the public key for the -IPSec peer: either copy it directly into *rsasigkey= in ipsec.conf, or -fetch it from dns. The magic value %dns for *rsasigkey parameters says to -try to fetch the peer's key from dns. - -For any parameters, you may find their significance and special values in -man ipsec.conf. If you are setting up keys or secrets, be sure also to -reference man ipsec.secrets.</pre> - -<h3><a name="dup_address">ipsec_setup: ... interfaces ... and ... share -address ...</a></h3> - -<p>This is a fatal error. FreeS/WAN cannot cope with two or more interfaces -using the same IP address. You must re-configure to avoid this.</p> - -<p>A mailing list message on the topic from Pluto developer Hugh -Redelmeier:</p> -<pre>| I'm trying to get freeswan working between two machine where one has a ppp -| interface. -| I've already suceeded with two machines with ethernet ports but the ppp -| interface is causing me problems. -| basically when I run ipsec start i get -| ipsec_setup: Starting FreeS/WAN IPsec 1.7... -| ipsec_setup: 003 IP interfaces ppp1 and ppp0 share address 192.168.0.10! -| ipsec_setup: 003 IP interfaces ppp1 and ppp2 share address 192.168.0.10! -| ipsec_setup: 003 IP interfaces ppp0 and ppp2 share address 192.168.0.10! -| ipsec_setup: 003 no public interfaces found -| -| followed by lots of cannot work out interface for connection messages -| -| now I can specify the interface in ipsec.conf to be ppp0 , but this does -| not affect the above behaviour. A quick look in server.c indicates that the -| interfaces value is not used but some sort of raw detect happens. -| -| I guess I could prevent the formation of the extra ppp interfaces or -| allocate them different ip but I'd rather not. if at all possible. Any -| suggestions please. - -Pluto won't touch an interface that shares an IP address with another. -This will eventually change, but it probably won't happen soon. - -For now, you will have to give the ppp1 and ppp2 different addresses.</pre> - -<h3><a name="kflags">ipsec_setup: Cannot adjust kernel flags</a></h3> - -<p>A mailing list message form technical lead Henry Spencer:</p> -<pre>> When FreeS/WAN IPsec 1.7 is starting on my 2.0.38 Linux kernel the following -> error message is generated: -> ipsec_setup: Cannot adjust kernel flags, no /proc/sys/net/ipsec directory! -> What is supposed to create this directory and how can I fix this problem? - -I think that directory is a 2.2ism, although I'm not certain (I don't have -a 2.0.xx system handy any more for testing). Without it, some of the -ipsec.conf config-setup flags won't work, but otherwise things should -function. </pre> - -<p>You also need to enable the <var>/proc</var> filesystem in your kernel -configuration for these operations to work.</p> - -<h3><a name="message_num">Message numbers (MI3, QR1, et cetera) in Pluto -messages</a></h3> - -<p>Pluto messages often indicate where Pluto is in the IKE protocols. The -letters indicate <strong>M</strong>ain mode or <strong>Q</strong>uick mode -and <strong>I</strong>nitiator or <strong>R</strong>esponder. The numerals -are message sequence numbers. For more detail, see our <a -href="ipsec.html#sequence">IPsec section</a>.</p> - -<h3><a name="conn_name">Connection names in Pluto error messages</a></h3> - -<p>From Pluto programmer Hugh Redelmeier:</p> -<pre>| Jan 17 16:21:10 remus Pluto[13631]: "jumble" #1: responding to Main Mode from Road Warrior 130.205.82.46 -| Jan 17 16:21:11 remus Pluto[13631]: "jumble" #1: no suitable connection for peer @banshee.wittsend.com -| -| The connection "jumble" has nothing to do with the incoming -| connection requests, which were meant for the connection "banshee". - -You are right. The message tells you which Connection Pluto is -currently using, which need not be the right one. It need not be the -right one now for the negotiation to eventually succeed! This is -described in ipsec_pluto(8) in the section "Road Warrior Support". - -There are two times when Pluto will consider switching Connections for -a state object. Both are in response to receiving ID payloads (one in -Phase 1 / Main Mode and one in Phase 2 / Quick Mode). The second is -not unique to Road Warriors. In fact, neither is the first any more -(two connections for the same pair of hosts could differ in Phase 1 ID -payload; probably nobody else has tried this).</pre> - -<h3><a name="cantorient">Pluto: ... can't orient connection</a></h3> - -<p>Older versions of FreeS/WAN used this message. The same error now gives -the "we have no ipsecN ..." error described just below.</p> - -<h3><a name="no.interface">... we have no ipsecN interface for either end of -this connection</a></h3> - -<p>Your tunnel has no IP address which matches the IP -address of any of the available IPsec interfaces. Either you've -misconfigured the connection, or you need to define an appropriate -IPsec interface connection. <VAR>interfaces=%defaultroute</VAR> works -in many cases.</p> - -<p>A longer story: Pluto needs to know whether it is running on -the machine which the -connection description calls <var>left</var> or on <var>right</var>. It -figures that out by:</p> -<ul> - <li>looking at the interfaces given in <var>interfaces=</var> lines in the - <var>config setup</var> section</li> - <li>discovering the IP addresses for those interfaces</li> - <li>searching for a match between those addresses and the ones given in - <var>left=</var> or <var>right=</var> lines.</li> -</ul> - -<p>Normally a match is found. Then Pluto knows where it is and can set up -other things (for example, if it is <var>left</var>) using parameters such as -<var>leftsubnet</var> and <var>leftnexthop</var>, and sending its outgoing -packets to <var>right</var>.</p> - -<p>If no match is found, it emits the above error message.</p> - -<h3><a name="noconn">Pluto: ... no connection is known</a></h3> - -<p>This error message occurs when a remote system attempts to negotiate a -connection and Pluto does not have a connection description that matches what -the remote system has requested. The most common cause is a configuration -error on one end or the other.</p> - -<p>Parameters involved in this match are <var>left</var>, <var>right</var>, -<var>leftsubnet</var> and <var>rightsubnet</var>.</p> - -<p><strong>The match must be exact</strong>. For example, if your left subnet -is a.b.c.0/24 then neither a single machine in that net nor a smaller subnet -such as a.b.c.64/26 will be considered a match.</p> - -<p>The message can also occur when an appropriate description exists but -Pluto has not loaded it. Use an <var>auto=add</var> statement in the -connection description, or an <var>ipsec auto --add <conn_name></var> -command, to correct this.</p> - -<p>An explanation from the Pluto developer:</p> -<pre>| Jul 12 15:00:22 sohar58 Pluto[574]: "corp_road" #2: cannot respond to IPsec -| SA request because no connection is known for -| 216.112.83.112/32===216.112.83.112...216.67.25.118 - -This is the first message from the Pluto log showing a problem. It -means that PGPnet is trying to negotiate a set of SAs with this -topology: - -216.112.83.112/32===216.112.83.112...216.67.25.118 -^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^ ^^^^^^^^^^^^^ -client on our side our host PGPnet host, no client - -None of the conns you showed look like this. - -Use - ipsec auto --status -to see a snapshot of what connections are in pluto, what -negotiations are going on, and what SAs are established. - -The leftsubnet= (client) in your conn is 216.112.83.64/26. It must -exactly match what pluto is looking for, and it does not.</pre> - -<h3><a name="nosuit">Pluto: ... no suitable connection ...</a></h3> - -<p>This is similar to the <a href="#noconn">no connection known</a> error, -but occurs at a different point in Pluto processing.</p> - -<p>Here is one of Claudia's messages explaining the problem:</p> -<pre>You write, - -> What could be the reason of the following error? -> "no suitable connection for peer '@xforce'" - -When a connection is initiated by the peer, Pluto must choose which entry in -the conf file best matches the incoming connection. A preliminary choice is -made on the basis of source and destination IPs, since that information is -available at that time. - -A payload containing an ID arrives later in the negotiation. Based on this -id and the *id= parameters, Pluto refines its conn selection. ... - -The message "no suitable connection" indicates that in this refining step, -Pluto does not find a connection that matches that ID. - -Please see "Selecting a connection when responding" in man ipsec_pluto for -more details.</pre> - -<p>See also <a href="#conn_name">Connection names in Pluto error -messages</a>.</p> - -<h3><a name="noconn.auth">Pluto: ... no connection has been -authorized</a></h3> - -<p>Here is one of Claudia's messages discussing this problem:</p> -<pre>You write, - -> May 22 10:46:31 debian Pluto[25834]: packet from x.y.z.p:10014: -> initial Main Mode message from x.y.z.p:10014 - but no connection has been authorized - -This error occurs early in the connection negotiation process, -at the first step of IKE negotiation (Main Mode), which is itself the -first of two negotiation phases involved in creating an IPSec connection. - -Here, Linux FreeS/WAN receives a packet from a potential peer, which -requests that they begin discussing a connection. - -The "no connection has been authorized" means that there is no connection -description in Linux FreeS/WAN's internal database that can be used to -link your ipsec interface with that peer. - -"But of course I configured that connection!" - -It may be that the appropriate connection description exists in ipsec.conf -but has not been added to the database with ipsec auto --add myconn or the -auto=add method. Or, the connection description may be misconfigured. - -The only parameters that are relevant in this decision are left= and right= . -Local and remote ports are also taken into account -- we see that the port -is printed in the message above -- but there is no way to control these -in ipsec.conf. - - -Failure at "no connection has been authorized" is similar to the -"no connection is known for..." error in the FAQ, and the "no suitable -connection" error described in the snapshot's FAQ. In all three cases, -Linux FreeS/WAN is trying to match parameters received in the -negotiation with the connection description in the local config file. - -As it receives more information, its matches take more parameters into -account, and become more precise: first the pair of potential peers, -then the peer IDs, then the endpoints (including any subnets). - -The "no suitable connection for peer *" occurs toward the end of IKE -(Main Mode) negotiation, when the IDs are matched. - -"no connection is known for a/b===c...d" is seen at the beginning of IPSec -(Quick Mode, phase 2) negotiation, when the connections are matched using -left, right, and any information about the subnets.</pre> - -<h3><a name="noDESsupport">Pluto: ... OAKLEY_DES_CBC is not -supported.</a></h3> - -<p>This message occurs when the other system attempts to negotiate a -connection using <a href="glossary.html#DES">single DES</a>, which we do not -support because it is <a href="politics.html#desnotsecure">insecure</a>.</p> - -<p>Our interoperation document has suggestions for <a -href="interop.html#noDES">how to deal with</a> systems that attempt to use -single DES.</p> - -<h3><a name="notransform">Pluto: ... no acceptable transform</a></h3> - -<p>This message means that the other gateway has made a proposal for -connection parameters, but nothing they proposed is acceptable to Pluto. -Possible causes include:</p> -<ul> - <li>misconfiguration on either end</li> - <li>policy incompatibilities, for example we require encrypted connections - but they are trying to create one with just authentication</li> - <li>interoperation problems, for example they offer only single DES and - FreeS/WAN does not support that. See <a - href="interop.html#interop.problem">discussion</a> in our interoperation - document.</li> -</ul> - -<p>A more detailed explanation, from Pluto programmer Hugh Redelmeier:</p> -<pre>Background: - -When one IKE system (for example, Pluto) is negotiating with another -to create an SA, the Initiator proposes a bunch of choices and the -Responder replies with one that it has selected. - -The structure of the choices is fairly complicated. An SA payload -contains a list of lists of "Proposals". The outer list is a set of -choices: the selection must be from one element of this list. - -Each of these elements is a list of Proposals. A selection must be -made from each of the elements of the inner list. In other words, -*all* of them apply (that is how, for example, both AH and ESP can -apply at once). - -Within each of these Proposals is a list of Transforms. For each -Proposal selected, one Transform must be selected (in other words, -each Proposal provides a choice of Transforms). - -Each Transform is made up of a list of Attributes describing, well, -attributes. Such as lifetime of the SA. Such as algorithm to be -used. All the Attributes apply to a Transform. - -You will have noticed a pattern here: layers alternate between being -disjunctions ("or") and conjunctions ("and"). - -For Phase 1 / Main Mode (negotiating an ISAKMP SA), this structure is -cut back. There must be exactly one Proposal. So this degenerates to -a list of Transforms, one of which must be chosen. - -In your case, no proposal was considered acceptable to Pluto (the -Responder). So negotiation ceased. Pluto logs the reason it rejects -each Transform. So look back in the log to see what is going wrong.</pre> - -<h3><a name="rsasigkey">rsasigkey dumps core</a></h3> -A comment on this error from Henry: -<pre>On Fri, 29 Jun 2001, Rodrigo Gruppelli wrote: -> ...Well, it seem that there's -> another problem with it. When I try to generate a pair of RSA keys, -> rsasigkey cores dump... - -*That* is a neon sign flashing "GMP LIBRARY IS BROKEN". Rsasigkey calls -GMP a lot, and our own library a little bit, and that's very nearly all it -does. Barring bugs in its code or our library -- which have happened, but -not very often -- a problem in rsasigkey is a problem in GMP.</pre> - -<p>See the next question for how to deal with GMP errors.</p> - -<h3><a name="sig4">!Pluto failure!: ... exited with ... signal 4</a></h3> - -<p>Pluto has died. Signal 4 is SIGILL, illegal instruction.</p> - -<p>The most likely cause is that your <a href="glossary.html#GMP">GMP</a> -(GNU multi-precision) library is compiled for a different processor than what -you are running on. Pluto uses that library for its public key -calculations.</p> - -<p>Try getting the GMP sources and recompile for your processor type. Most -Linux distributions will include this source, or you can download it from the -<a href="http://www.swox.com/gmp/">GMP home page</a>.</p> - -<h3><a name="econnrefused">ECONNREFUSED error message</a></h3> - -<p>From John Denker, on the mailing list:</p> -<pre>1) The log message - some IKE message we sent has been rejected with - ECONNREFUSED (kernel supplied no details) -is much more suitable than the previous version. Thanks. - -2) Minor suggestion for further improvement: it might be worth mentioning -that the command - tcpdump -i eth1 icmp[0] != 8 and icmp[0] != 0 -is useful for tracking down the details in question. We shouldn't expect -all IPsec users to figure that out on their own. The log message might -even provide a hint as to where to look in the docs.</pre> - -<p>Reply From Pluto developer Hugh Redelmeier</p> -<pre>Good idea. - -I've added a bit pluto(8)'s BUGS section along these lines. -I didn't have the heart to lengthen this message.</pre> - -<h3><a name="no_eroute">klips_debug: ... no eroute!</a></h3> - -<p>This message means <a href="glossary.html#KLIPS">KLIPS</a> has received a -packet for which no IPsec tunnel has been defined.</p> - -<p>Here is a more detailed duscussion from the team's tech support person -Claudia Schmeing, responding to a query on the mailing list:</p> -<pre>> Why ipsec reports no eroute! ???? IP Masq... is disabled. - -In general, more information is required so that people on the list may -give you informed input. See doc/prob.report.</pre> - -<p>The document she refers to has since been replaced by a <a -href="trouble.html#prob.report">section</a> of the troubleshooting -document.</p> -<pre>However, I can make some general comments on this type of error. - -This error usually looks something like this (clipped from an archived -message): - -> ttl:64 proto:1 chk:45459 saddr:192.168.1.2 daddr:192.168.100.1 -> ... klips_debug:ipsec_findroute: 192.168.1.2->192.168.100.1 -> ... klips_debug:rj_match: * See if we match exactly as a host destination -> ... klips_debug:rj_match: ** try to match a leaf, t=0xc1a260b0 -> ... klips_debug:rj_match: *** start searching up the tree, t=0xc1a260b0 -> ... klips_debug:rj_match: **** t=0xc1a260c8 -> ... klips_debug:rj_match: **** t=0xc1fe5960 -> ... klips_debug:rj_match: ***** not found. -> ... klips_debug:ipsec_tunnel_start_xmit: Original head/tailroom: 2, 28 -> ... klips_debug:ipsec_tunnel_start_xmit: no eroute!: ts=47.3030, dropping. - - -What does this mean? -- -------------------- - -"eroute" stands for "extended route", and is a special type of route -internal to Linux FreeS/WAN. For more information about this type of route, -see the section of man ipsec_auto on ipsec auto --route. - -"no eroute!" here means, roughly, that Linux FreeS/WAN cannot find an -appropriate tunnel that should have delivered this packet. Linux -FreeS/WAN therefore drops the packet, with the message "no eroute! ... -dropping", on the assumption that this packet is not a legitimate -transmission through a properly constructed tunnel. - - -How does this situation come about? -- ----------------------------------- - -Linux FreeS/WAN has a number of connection descriptions defined in -ipsec.conf. These must be successfully brought "up" to form actual tunnels. -(see doc/setup.html's step 15, man ipsec.conf and man ipsec_auto -for details). - -Such connections are often specific to the endpoints' IPs. However, in -some cases they may be more general, for example in the case of -Road Warriors where left or right is the special value %any. - -When Linux FreeS/WAN receives a packet, it verifies that the packet has -come through a legitimate channel, by checking that there is an -appropriate tunnel through which this packet might legitimately have -arrived. This is the process we see above. - -First, it checks for an eroute that exactly matches the packet. In the -example above, we see it checking for a route that begins at 192.168.1.2 -and ends at 192.168.100.1. This search favours the most specific match that -would apply to the route between these IPs. So, if there is a connection -description exactly matching these IPs, the search will end there. If not, -the code will search for a more general description matching the IPs. -If there is no match, either specific or general, the packet will be -dropped, as we see, above. - -Unless you are working with Road Warriors, only the first, specific part -of the matching process is likely to be relevant to you. - - -"But I defined the tunnel, and it came up, why do I have this error?" -- --------------------------------------------------------------------- - -One of the most common causes of this error is failure to specify enough -connection descriptions to cover all needed tunnels between any two -gateways and their respective subnets. As you have noticed, troubleshooting -this error may be complicated by the use of IP Masq. However, this error is -not limited to cases where IP Masq is used. - -See doc/configuration.html#multitunnel for a detailed example of the -solution to this type of problem.</pre> - -<p>The documentation section she refers to is now <a -href="adv_config.html#multitunnel">here</a>.</p> - -<h3><a name="SAused">... trouble writing to /dev/ipsec ... SA already in -use</a></h3> - -<p>This error message occurs when two manual connections are set up with the -same SPI value. </p> - -<p>See the FAQ for <a href="#spi_error">One manual connection works, but -second one fails</a>.</p> - -<h3><a name="ignore">... ignoring ... payload</a></h3> - -<p>This message is harmless. The IKE protocol provides for a number of -optional messages types:</p> -<ul> - <li>delete SA</li> - <li>initial contact</li> - <li>vendor ID</li> - <li>...</li> -</ul> - -<p>An implementation is never required to send these, but they are allowed -to. The receiver is not required to do anything with them. FreeS/WAN ignores -them, but notifies you via the logs.</p> - -<p>For the "ignoring delete SA Payload" message, see also our discussion of -cleaning up <a href="#deadtunnel">dead tunnels</a>.</p> - -<h3><a name="unknown_rightcert">unknown parameter name "rightcert"</a></h3> - -<P>This message can appear when you've upgraded an X.509-enabled -Linux FreeS/WAN with a vanilla Linux FreeS/WAN. To use your X.509 configs -you will need to overwrite the new install with -<A HREF="http://www.freeswan.ca">Super FreeS/WAN</A>, or add the -<A HREF="http://www.strongsec.ca/freeswan">X.509 patch</A> by hand. -</P> - -<h2><a name="spam">Why don't you restrict the mailing lists to reduce -spam?</a></h2> - -<p>As a matter of policy, some of our <a href="mail.html">mailing lists</a> -need to be open to non-subscribers. Project management feel strongly that -maintaining this openness is more important than blocking spam.</p> -<ul> - <li>Users should be able to get help or report bugs without - subscribing.</li> - <li>Even a user who is subscribed may not have access to his or her - subscribed account when he or she needs help, miles from home base in the - middle of setting up a client's gateway.</li> - <li>There is arguably a legal requirement for this policy. A US resident or - citizen could be charged under munitions export laws for providing - technical assistance to a foreign cryptographic project. Such a charge - would be more easily defended if the discussion takes place in public, on - an open list.</li> -</ul> - -<p>This has been discussed several times at some length on the list. See the -<a href="mail.html#archive">list archives</a>. Bringing the topic up again is -unlikely to be useful. Please don't. Or at the very least, please don't -without reading the archives and being certain that whatever you are about to -suggest has not yet been discussed.</p> - -<p>Project technical lead Henry Spencer summarised one discussion:</p> - -<blockquote> - For the third and last time: this list *will* *not* do address-based - filtering. This is a policy decision, not an implementation problem. The - decision is final, and is not open to discussion. This needs to be - communicated better to people, and steps are being taken to do -that.</blockquote> - -<p>Adding this FAQ section is one of the steps he refers to.</p> - -<p>You have various options other than just putting up with the spam, -filtering it yourself, or unsubscribing:</p> -<ul> - <li>subscribe only to one or both of our lists with restricted posting - rules: - <ul> - <li><a - href="mailto:briefs@lists.freeswan.org?body=subscribe">briefs</a>, - weekly list summaries</li> - <li><a - href="mailto:announce@lists.freeswan.org?body=subscribe">announce</a>, - project-related announcements</li> - </ul> - </li> - <li>read the other lists via the <a - href="mail.html#archive">archives</a></li> -</ul> - -<p>A number of tools are available to filter mail.</p> -<ul> - <li>Many mail readers include some filtering capability.</li> - <li>Many Linux distributions include <a - href="http://www.procmail.org/">procmail(8)</a> for server-side - filtering.</li> - <li>The <a href="http://www.spambouncer.org/">Spam Bouncer</a> is a set of - procmail(8) filters designed to combat spam.</li> - <li>Roaring Penguin have a <a - href="http://www.roaringpenguin.com/mimedefang/">MIME defanger</a> that - removes potentially dangerous attachments.</li> -</ul> - -<p>If you use your ISP's mail server rather than running your own, consider -suggesting to the ISP that they tag suspected spam as <a -href="http://www.msen.com/1997/spam.html#SUSPECTED">this ISP</a> does. They -could just refuse mail from dubious sources, but that is tricky and runs some -risk of losing valuable mail or senselessly annoying senders and their -admins. However, they can safely tag and deliver dubious mail. The tags can -greatly assist your filtering.</p> - -<p>For information on tracking down spammers, see these <a -href="http://www.rahul.net/falk/#howtos">HowTos</a>, or the <a -href="http://www.sputum.com/index2.html">Sputum</a> site. Sputum have a Linux -anti-spam screensaver available for download.</p> - -<p>Here is a more detailed message from Henry:</p> -<pre>On Mon, 15 Jan 2001, Jay Vaughan wrote: -> I know I'm flogging a dead horse here, but I'm curious as to the reasons for -> an aversion for a subscriber-only mailing list? - -Once again: for legal reasons, it is important that discussions of these -things be held in a public place -- the list -- and we do not want to -force people to subscribe to the list just to ask one question, because -that may be more than merely inconvenient for them. There are also real -difficulties with people who are temporarily forced to use alternate -addresses; that is precisely the time when they may be most in need of -help, yet a subscribers-only policy shuts them out. - -These issues do not apply to most mailing lists, but for a list that is -(necessarily) the primary user support route for a crypto package, they -are very important. This is *not* an ordinary mailing list; it has to -function under awkward constraints that make various simplistic solutions -inapplicable or undesirable. - -> We're *ALL* sick of hearing about list management problems, not just you -> old-timers, so why don't you DO SOMETHING EFFECTIVE ABOUT IT... - -Because it's a lot harder than it looks, and many existing "solutions" -have problems when examined closely. - -> A suggestion for you, based on 10 years of experience with management of my -> own mailing lists would be to use mailman, which includes pretty much every -> feature under the sun that you guys need and want, plus some. The URL for -> mailman... - -I assure you, we're aware of mailman. Along with a whole bunch of others, -including some you almost certainly have never heard of (I hadn't!). - -> As for the argument that the list shouldn't be configured to enforce -> subscription - I contend that it *SHOULD* AT LEAST require manual address -> verification in order for posts to be redirected. - -You do realize, I hope, that interposing such a manual step might cause -your government to decide that this is not truly a public forum, and thus -you could go to jail if you don't get approval from them before mailing to -it? If you think this sounds irrational, your government is noted for -making irrational decisions in this area; we can't assume that they will -suddenly start being sensible. See above about awkward constraints. You -may be willing to take the risk, but we can't, in good conscience, insist -that all users with problems do so. - - Henry Spencer - henry@spsystems.net</pre> - -<p>and a message on the topic from project leader John Gilmore:</p> -<pre>Subject: Re: The linux-ipsec list's topic - Date: Sat, 30 Dec 2000 - From: John Gilmore <gnu@toad.com> - -I'll post this single message, once only, in this discussion, and then -not burden the list with any further off-topic messages. I encourage -everyone on the list to restrain themself from posting ANY off-topic -messages to the linux-ipsec list. - -The topic of the linux-ipsec mailing list is the FreeS/WAN software. - -I frequently see "discussions about spam on a list" overwhelm the -volume of "actual spam" on a list. BOTH kinds of messages are -off-topic messages. Twenty anti-spam messages take just as long to -detect and discard as twenty spam messages. - -The Linux-ipsec list encourages on-topic messages from people who have -not joined the list itself. We will not censor messages to the list -based on where they originate, or what return address they contain. -In other words, non-subscribers ARE allowed to post, and this will not -change. My own valid contributions have been rejected out-of-hand by -too many other mailing lists for me to want to impose that censorship -on anybody else's contributions. And every day I see the damage that -anti-spam zeal is causing in many other ways; that zeal is far more -damaging to the culture of the Internet than the nuisance of spam. - -In general, it is the responsibility of recipients to filter, -prioritize, or otherwise manage the handling of email that comes to -them. It is not the responsibility of the rest of the Internet -community to refrain from sending messages to recipients that they -might not want to see. If your software infrastructure for managing -your incoming email is insufficient, then improve it. If you think -the signal-to-noise ratio on linux-ipsec is too poor, then please -unsubscribe. But don't further increase the noise by posting to the -linux-ipsec list about those topics. - - John Gilmore - founder & sponsor, FreeS/WAN project</pre> -</body> -</html> diff --git a/doc/src/firewall.html b/doc/src/firewall.html deleted file mode 100644 index 5051b458d..000000000 --- a/doc/src/firewall.html +++ /dev/null @@ -1,895 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>FreeS/WAN and firewalls</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, firewall, ipchains, iptables"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: firewall.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1><a name="firewall">FreeS/WAN and firewalls</a></h1> - -<p>FreeS/WAN, or other IPsec implementations, frequently run on gateway -machines, the same machines running firewall or packet filtering code. This -document discusses the relation between the two.</p> - -<p>The firewall code in 2.4 and later kernels is called Netfilter. The -user-space utility to manage a firewall is iptables(8). See the <a -href="http://netfilter.samba.org">netfilter/iptables web site</a> for -details.</p> - -<h2><a name="filters">Filtering rules for IPsec packets</a></h2> - -<p>The basic constraint is that <strong>an IPsec gateway must have packet -filters that allow IPsec packets</strong>, at least when talking to other -IPsec gateways:</p> -<ul> - <li>UDP port 500 for <a href="glossary.html#IKE">IKE</a> negotiations</li> - <li>protocol 50 if you use <a href="glossary.html#ESP">ESP</a> encryption - and/or authentication (the typical case)</li> - <li>protocol 51 if you use <a href="glossary.html#AH">AH</a> packet-level - authentication</li> -</ul> - -<p>Your gateway and the other IPsec gateways it communicates with must be -able to exchange these packets for IPsec to work. Firewall rules must allow -UDP 500 and at least one of <a href="glossary.html#AH">AH</a> or -<a href="glossary.html#ESP">ESP</a> on -the interface that communicates with the other gateway.</p> - -<p>For nearly all FreeS/WAN applications, you must allow UDP port 500 and the -ESP protocol.</p> - -<p>There are two ways to set this up:</p> -<dl> - <dt>easier but less flexible</dt> - <dd>Just set up your firewall scripts at boot time to allow IPsec packets - to and from your gateway. Let FreeS/WAN reject any bogus packets.</dd> - <dt>more work, giving you more precise control</dt> - <dd>Have the <a href="manpage.d/ipsec_pluto.8.html">ipsec_pluto(8)</a> - daemon call scripts to adjust firewall rules dynamically as required. - This is done by naming the scripts in the <a - href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a> variables - <var>prepluto=</var>, <var>postpluto=</var>, <var>leftupdown=</var> and - <var>rightupdown=</var>.</dd> -</dl> - -<p>Both methods are described in more detail below.</p> - -<h2><a name="examplefw">Firewall configuration at boot</a></h2> - -<p>It is possible to set up both firewalling and IPsec with appropriate -scripts at boot and then not use <var>leftupdown=</var> and -<var>rightupdown=</var>, or use them only for simple up and down -operations.</p> - -<p>Basically, the technique is</p> -<ul> - <li>allow IPsec packets (typically, IKE on UDP port 500 plus ESP, protocol - 50) - <ul> - <li>incoming, if the destination address is your gateway (and - optionally, only from known senders)</li> - <li>outgoing, with the from address of your gateway (and optionally, - only to known receivers)</li> - </ul> - </li> - <li>let <a href="glossary.html#Pluto">Pluto</a> deal with IKE</li> - <li>let <a href="glossary.html#KLIPS">KLIPS</a> deal with ESP</li> -</ul> - -<p>Since Pluto authenticates its partners during the negotiation, and KLIPS -drops packets for which no tunnel has been negotiated, this may be all you -need.</p> - -<h3><a name="simple.rules">A simple set of rules</a></h3> - -<p>In simple cases, you need only a few rules, as in this example:</p> -<pre># allow IPsec -# -# IKE negotiations -iptables -I INPUT -p udp --sport 500 --dport 500 -j ACCEPT -iptables -I OUTPUT -p udp --sport 500 --dport 500 -j ACCEPT -# ESP encryption and authentication -iptables -I INPUT -p 50 -j ACCEPT -iptables -I OUTPUT -p 50 -j ACCEPT -</pre> - -<P>This should be all you need to allow IPsec through <var>lokkit</var>, -which ships with Red Hat 9, on its medium security setting. -Once you've tweaked to your satisfaction, save your active rule set with:</P> -<PRE>service iptables save</PRE> - -<h3><a name="complex.rules">Other rules</a></h3> -You can add additional rules, or modify existing ones, to work with IPsec and -with your network and policies. We give a some examples in this section. - -<p>However, while it is certainly possible to create an elaborate set of -rules yourself (please let us know via the <a href="mail.html">mailing -list</a> if you do), it may be both easier and more secure to use a set which -has already been published and tested.</p> - -<p>The published rule sets we know of are described in the <a -href="#rules.pub">next section</a>.</p> - -<h4>Adding additional rules</h4> -If necessary, you can add additional rules to: -<dl> - <dt>reject IPsec packets that are not to or from known gateways</dt> - <dd>This possibility is discussed in more detail <a - href="#unknowngate">later</a></dd> - <dt>allow systems behind your gateway to build IPsec tunnels that pass - through the gateway</dt> - <dd>This possibility is discussed in more detail <a - href="#through">later</a></dd> - <dt>filter incoming packets emerging from KLIPS.</dt> - <dd>Firewall rules can recognise packets emerging from IPsec. They are - marked as arriving on an interface such as <var>ipsec0</var>, rather - than <var>eth0</var>, <var>ppp0</var> or whatever.</dd> -</dl> - -<p>It is therefore reasonably straightforward to filter these packets in -whatever way suits your situation.</p> - -<h4>Modifying existing rules</h4> - -<p>In some cases rules that work fine before you add IPsec may require -modification to work with IPsec.</p> - -<p>This is especially likely for rules that deal with interfaces on the -Internet side of your system. IPsec adds a new interface; often the rules -must change to take account of that.</p> - -<p>For example, consider the rules given in <a -href="http://www.netfilter.org/documentation/HOWTO//packet-filtering-HOWTO-5.html">this -section</a> of the Netfilter documentation:</p> -<pre>Most people just have a single PPP connection to the Internet, and don't -want anyone coming back into their network, or the firewall: - - ## Insert connection-tracking modules (not needed if built into kernel). - # insmod ip_conntrack - # insmod ip_conntrack_ftp - - ## Create chain which blocks new connections, except if coming from inside. - # iptables -N block - # iptables -A block -m state --state ESTABLISHED,RELATED -j ACCEPT - # iptables -A block -m state --state NEW -i ! ppp0 -j ACCEPT - # iptables -A block -j DROP - - ## Jump to that chain from INPUT and FORWARD chains. - # iptables -A INPUT -j block - # iptables -A FORWARD -j block</pre> - -<p>On an IPsec gateway, those rules may need to be modified. The above allows -new connections from <em>anywhere except ppp0</em>. That means new -connections from ipsec0 are allowed.</p> - -<p>Do you want to allow anyone who can establish an IPsec connection to your -gateway to initiate TCP connections to any service on your network? Almost -certainly not if you are using opportunistic encryption. Quite possibly not -even if you have only explicitly configured connections.</p> - -<p>To disallow incoming connections from ipsec0, change the middle section -above to:</p> -<pre> ## Create chain which blocks new connections, except if coming from inside. - # iptables -N block - # iptables -A block -m state --state ESTABLISHED,RELATED -j ACCEPT - # iptables -A block -m state --state NEW -i ppp+ -j DROP - # iptables -A block -m state --state NEW -i ipsec+ -j DROP - # iptables -A block -m state --state NEW -i -j ACCEPT - # iptables -A block -j DROP</pre> - -<p>The original rules accepted NEW connections from anywhere except ppp0. -This version drops NEW connections from any PPP interface (ppp+) and from any -ipsec interface (ipsec+), then accepts the survivors.</p> - -<p>Of course, these are only examples. You will need to adapt them to your -own situation.</p> - -<h3><a name="rules.pub">Published rule sets</a></h3> - -<p>Several sets of firewall rules that work with FreeS/WAN are available.</p> - -<h4><a name="Ranch.trinity">Scripts based on Ranch's work</a></h4> - -<p>One user, Rob Hutton, posted his boot time scripts to the mailing list, -and we included them in previous versions of this documentation. They are -still available from our <a -href="http://www.freeswan.org/freeswan_trees/freeswan-1.5/doc/firewall.html#examplefw">web -site</a>. However, they were for an earlier FreeS/WAN version so we no longer -recommend them. Also, they had some bugs. See this <a -href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/04/msg00316.html">message</a>.</p> - -<p>Those scripts were based on David Ranch's scripts for his "Trinity OS" for -setting up a secure Linux. Check his <a -href="http://www.ecst.csuchico.edu/~dranch/LINUX/index-linux.html">home -page</a> for the latest version and for information on his <a -href="biblio.html#ranch">book</a> on securing Linux. If you are going to base -your firewalling on Ranch's scripts, we recommend using his latest version, -and sending him any IPsec modifications you make for incorporation into later -versions.</p> - -<h4><a name="seawall">The Seattle firewall</a></h4> - -<p>We have had several mailing lists reports of good results using FreeS/WAN -with Seawall (the Seattle Firewall). See that project's <a -href="http://seawall.sourceforge.net/">home page</a> on Sourceforge.</p> - -<h4><a name="rcf">The RCF scripts</a></h4> - -<p>Another set of firewall scripts with IPsec support are the RCF or -rc.firewall scripts. See their <a -href="http://jsmoriss.mvlan.net/linux/rcf.html">home page</a>.</p> - -<h4><a name="asgard">Asgard scripts</a></h4> - -<p><a href="http://heimdall.asgardsrealm.net/linux/firewall/">Asgard's -Realm</a> has set of firewall scripts with FreeS/WAN support, for 2.4 kernels -and iptables.</p> - -<h4><a name="user.scripts">User scripts from the mailing list</a></h4> - -<p>One user gave considerable detail on his scripts, including supporting <a -href="glossary.html#IPX">IPX</a> through the tunnel. His message was too long -to conveniently be quoted here, so I've put it in a <a -href="user_examples.html">separate file</a>.</p> - -<h2><a name="updown">Calling firewall scripts, named in ipsec.conf(5)</a></h2> - -<p>The <a href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a> configuration -file has three pairs of parameters used to specify an interface between -FreeS/WAN and firewalling code.</p> - -<p>Note that using these is not required if you have a static firewall setup. -In that case, you just set your firewall up at boot time (in a way that -permits the IPsec connections you want) and do not change it thereafter. Omit -all the FreeS/WAN firewall parameters and FreeS/WAN will not attempt to -adjust firewall rules at all. See <a href="#examplefw">above</a> for some -information on appropriate scripts.</p> - -<p>However, if you want your firewall rules to change when IPsec connections -change, then you need to use these parameters.</p> - -<h3><a name="pre_post">Scripts called at IPsec start and stop</a></h3> - -<p>One pair of parmeters are set in the <var>config setup</var> section of -the <a href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a> file and affect -all connections:</p> -<dl> - <dt>prepluto=</dt> - <dd>script to be called before <a - href="manpage.d/ipsec_pluto.8.html">pluto(8)</a> IKE daemon is - started.</dd> - <dt>postpluto=</dt> - <dd>script to be called after <a - href="manpage.d/ipsec_pluto.8.html">pluto(8)</a> IKE daemon is - stopped.</dd> -</dl> -These parameters allow you to change firewall parameters whenever IPsec is -started or stopped. - -<p>They can also be used in other ways. For example, you might have -<var>prepluto</var> add a module to your kernel for the secure network -interface or make a dialup connection, and then have <var>postpluto</var> -remove the module or take the connection down.</p> - -<h3><a name="up_down">Scripts called at connection up and down</a></h3> - -<p>The other parameters are set in connection descriptions. They can be set -in individual connection descriptions, and could even call different scripts -for each connection for maximum flexibility. In most applications, however, -it makes sense to use only one script and to call it from <var>conn -%default</var> section so that it applies to all connections.</p> - -<p>You can:</p> -<dl> - <dt><strong>either</strong></dt> - <dd>set <var>leftfirewall=yes</var> or <var>rightfirewall=yes</var> to - use our supplied default script</dd> - <dt><strong>or</strong></dt> - <dd>assign a name in a <var>leftupdown=</var> or <var>rightupdown=</var> - line to use your own script</dd> -</dl> - -<p>Note that <strong>only one of these should be used</strong>. You cannot -sensibly use both. Since <strong>our default script is obsolete</strong> -(designed for firewalls using <var>ipfwadm(8)</var> on 2.0 kernels), most -users who need this service will <strong>need to write a custom -script</strong>.</p> - -<h4><a name="fw.default">The default script</a></h4> - -<p>We supply a default script named <var>_updown</var>.</p> -<dl> - <dt>leftfirewall=</dt> - <dd></dd> - <dt>rightfirewall=</dt> - <dd>indicates that the gateway is doing firewalling and that <a - href="manpage.d/ipsec_pluto.8.html">pluto(8)</a> should poke holes in - the firewall as required.</dd> -</dl> - -<p>Set these to <var>yes</var> and Pluto will call our default script -<var>_updown</var> with appropriate arguments whenever it:</p> -<ul> - <li>starts or stops IPsec services</li> - <li>brings a connection up or down</li> -</ul> - -<p>The supplied default <var>_updown</var> script is appropriate for simple -cases using the <var>ipfwadm(8)</var> firewalling package.</p> - -<h4><a name="userscript">User-written scripts</a></h4> - -<p>You can also write your own script and have Pluto call it. Just put the -script's name in one of these <a -href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a> lines:</p> -<dl> - <dt>leftupdown=</dt> - <dd></dd> - <dt>rightupdown=</dt> - <dd>specifies a script to call instead of our default script - <var>_updown</var>.</dd> -</dl> - -<p>Your script should take the same arguments and use the same environment -variables as <var>_updown</var>. See the "updown command" section of the <a -href="manpage.d/ipsec_pluto.8.html">ipsec_pluto(8)</a> man page for -details.</p> - -<p>Note that <strong>you should not modify our _updown script in -place</strong>. If you did that, then upgraded FreeS/WAN, the upgrade would -install a new default script, overwriting your changes.</p> - -<h3><a name="ipchains.script">Scripts for ipchains or iptables</a></h3> - -<p>Our <var>_updown</var> is for firewalls using <var>ipfwadm(8)</var>, the -firewall code for the 2.0 series of Linux kernels. If you are using the more -recent packages <var>ipchains(8)</var> (for 2.2 kernels) or -<var>iptables(8)</var> (2.4 kernels), then you must do one of:</p> -<ul> - <li>use static firewall rules which are set up at boot time as described <a - href="#examplefw">above</a> and do not need to be changed by Pluto</li> - <li>limit yourself to ipchains(8)'s ipfwadm(8) emulation mode in order to - use our script</li> - <li>write your own script and call it with <var>leftupdown</var> and - <var>rightupdown</var>.</li> -</ul> - -<p>You can write a script to do whatever you need with firewalling. Specify -its name in a <var>[left|right]updown=</var> parameter in <a -href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a> and Pluto will -automatically call it for you.</p> - -<p>The arguments Pluto passes such a script are the same ones it passes to -our default _updown script, so the best way to build yours is to copy ours -and modify the copy.</p> - -<p>Note, however, that <strong>you should not modify our _updown script in -place</strong>. If you did that, then upgraded FreeS/WAN, the upgrade would -install a new default script, overwriting your changes.</p> - -<h2><a name="NAT">A complication: IPsec vs. NAT</a></h2> - -<p><a href="glossary.html#NAT.gloss">Network Address Translation</a>, also -known as IP masquerading, is a method of allocating IP addresses dynamically, -typically in circumstances where the total number of machines which need to -access the Internet exceeds the supply of IP addresses.</p> - -<p>Any attempt to perform NAT operations on IPsec packets <em>between the -IPsec gateways</em> creates a basic conflict:</p> -<ul> - <li>IPsec wants to authenticate packets and ensure they are unaltered on a - gateway-to-gateway basis</li> - <li>NAT rewrites packet headers as they go by</li> - <li>IPsec authentication fails if packets are rewritten anywhere between - the IPsec gateways</li> -</ul> - -<p>For <a href="glossary.html#AH">AH</a>, which authenticates parts of the -packet header including source and destination IP addresses, this is fatal. -If NAT changes those fields, AH authentication fails.</p> - -<p>For <a href="glossary.html#IKE">IKE</a> and <a -href="glossary.html#ESP">ESP</a> it is not necessarily fatal, but is -certainly an unwelcome complication.</p> - -<h3><a name="nat_ok">NAT on or behind the IPsec gateway works</a></h3> - -<p>This problem can be avoided by having the masquerading take place <em>on -or behind</em> the IPsec gateway.</p> - -<p>This can be done physically with two machines, one physically behind the -other. A picture, using SG to indicate IPsec <strong>S</strong>ecurity -<strong>G</strong>ateways, is:</p> -<pre> clients --- NAT ----- SG ---------- SG - two machines</pre> - -<p>In this configuration, the actual client addresses need not be given in -the <var>leftsubnet=</var> parameter of the FreeS/WAN connection description. -The security gateway just delivers packets to the NAT box; it needs only that -machine's address. What that machine does with them does not affect -FreeS/WAN.</p> - -<p>A more common setup has one machine performing both functions:</p> -<pre> clients ----- NAT/SG ---------------SG - one machine</pre> - -<p>Here you have a choice of techniques depending on whether you want to make -your client subnet visible to clients on the other end:</p> -<ul> - <li>If you want the single gateway to behave like the two shown above, with - your clients hidden behind the NAT, then omit the <var>leftsubnet=</var> - parameter. It then defaults to the gateway address. Clients on the other - end then talk via the tunnel only to your gateway. The gateway takes - packets emerging from the tunnel, applies normal masquerading, and - forwards them to clients.</li> - <li>If you want to make your client machines visible, then give the client - subnet addresses as the <var>leftsubnet=</var> parameter in the - connection description and - <dl> - <dt>either</dt> - <dd>set <var>leftfirewall=yes</var> to use the default - <var>updown</var> script</dd> - <dt>or</dt> - <dd>use your own script by giving its name in a - <var>leftupdown=</var> parameter</dd> - </dl> - These scripts are described in their own <a href="#updown">section</a>. - <p>In this case, no masquerading is done. Packets to or from the client - subnet are encrypted or decrypted without any change to their client - subnet addresses, although of course the encapsulating packets use - gateway addresses in their headers. Clients behind the right security - gateway see a route via that gateway to the left subnet.</p> - </li> -</ul> - -<h3><a name="nat_bad">NAT between gateways is problematic</a></h3> - -<p>We recommend not trying to build IPsec connections which pass through a -NAT machine. This setup poses problems:</p> -<pre> clients --- SG --- NAT ---------- SG</pre> - -<p>If you must try it, some references are:</p> -<ul> - <li>Jean_Francois Nadeau's document on doing <a - href="http://jixen.tripod.com/#NATed gateways">IPsec behind NAT</a></li> - <li><a href="web.html#VPN.masq">VPN masquerade patches</a> to make a Linux - NAT box handle IPsec packets correctly</li> -</ul> - -<h3><a name="NAT.ref">Other references on NAT and IPsec</a></h3> - -<p>Other documents which may be relevant include:</p> -<ul> - <li>an Internet Draft on <a - href="http://search.ietf.org/internet-drafts/draft-aboba-nat-ipsec-04.txt">IPsec - and NAT</a> which may eventually evolve into a standard solution for this - problem.</li> - <li>an informational <a - href="http://www.cis.ohio-state.edu/rfc/rfc2709.txt">RFC</a>, - <cite>Security Model with Tunnel-mode IPsec for NAT Domains</cite>.</li> - <li>an <a - href="http://www.cisco.com/warp/public/759/ipj_3-4/ipj_3-4_nat.html">article</a> - in Cisco's <cite>Internet Protocol Journal</cite></li> -</ul> - -<h2><a name="complications">Other complications</a></h2> - -<p>Of course simply allowing UDP 500 and ESP packets is not the whole story. -Various other issues arise in making IPsec and packet filters co-exist and -even co-operate. Some of them are summarised below.</p> - -<h3><a name="through">IPsec <em>through</em></a> the gateway</h3> - -<p>Basic IPsec packet filtering rules deal only with packets addressed to or -sent from your IPsec gateway.</p> - -<p>It is a separate policy decision whether to permit such packets to pass -through the gateway so that client machines can build end-to-end IPsec -tunnels of their own. This may not be practical if you are using <a -href="#NAT">NAT (IP masquerade)</a> on your gateway, and may conflict with -some corporate security policies.</p> - -<p>Where possible, allowing this is almost certainly a good idea. Using IPsec -on an end-to-end basis is more secure than gateway-to-gateway.</p> - -<p>Doing it is quite simple. You just need firewall rules that allow UDP port -500 and protocols 50 and 51 to pass through your gateway. If you wish, you -can of course restrict this to certain hosts.</p> - -<h3><a name="ipsec_only">Preventing non-IPsec traffic</a></h3> -You can also filter <em>everything but</em> UDP port 500 and ESP or AH to -restrict traffic to IPsec only, either for anyone communicating with your -host or just for specific partners. - -<p>One application of this is for the telecommuter who might have:</p> -<pre> Sunset==========West------------------East ================= firewall --- the Internet - home network untrusted net corporate network</pre> - -<p>The subnet on the right is 0.0.0.0/0, the whole Internet. The West gateway -is set up so that it allows only IPsec packets to East in or out.</p> - -<p>This configuration is used in AT&T Research's network. For details, -see the <a href="intro.html#applied">papers</a> links in our introduction.</p> - -<p>Another application would be to set up firewall rules so that an internal -machine, such as an employees-only web server, could not talk to the outside -world except via specific IPsec tunnels.</p> - -<h3><a name="unknowngate">Filtering packets from unknown gateways</a></h3> - -<p>It is possible to use firewall rules to restrict UDP 500, ESP and AH -packets so that these packets are accepted only from known gateways. This is -not strictly necessary since FreeS/WAN will discard packets from unknown -gateways. You might, however, want to do it for any of a number of reasons. -For example:</p> -<ul> - <li>Arguably, "belt and suspenders" is the sensible approach to security. - If you can block a potential attack in two ways, use both. The only - question is whether to look for a third way after implementing the first - two.</li> - <li>Some admins may prefer to use the firewall code this way because they - prefer firewall logging to FreeS/WAN's logging.</li> - <li>You may need it to implement your security policy. Consider an employee - working at home, and a policy that says traffic from the home system to - the Internet at large must go first via IPsec to the corporate LAN and - then out to the Internet via the corporate firewall. One way to do that - is to make <var>ipsec0</var> the default route on the home gateway and - provide exceptions only for UDP 500 and ESP to the corporate gateway. - Everything else is then routed via the tunnel to the corporate - gateway.</li> -</ul> - -<p>It is not possible to use only static firewall rules for this filtering if -you do not know the other gateways' IP addresses in advance, for example if -you have "road warriors" who may connect from a different address each time -or if want to do <a href="glossary.html#carpediem">opportunistic -encryption</a> to arbitrary gateways. In these cases, you can accept UDP 500 -IKE packets from anywhere, then use the <a href="#updown">updown</a> script -feature of <a href="manpage.d/ipsec_pluto.8.html">pluto(8)</a> to dynamically -adjust firewalling for each negotiated tunnel.</p> - -<p>Firewall packet filtering does not much reduce the risk of a <a -href="glossary.html#DOS">denial of service attack</a> on FreeS/WAN. The -firewall can drop packets from unknown gateways, but KLIPS does that quite -efficiently anyway, so you gain little. The firewall cannot drop otherwise -legitmate packets that fail KLIPS authentication, so it cannot protect -against an attack designed to exhaust resources by making FreeS/WAN perform -many expensive authentication operations.</p> - -<p>In summary, firewall filtering of IPsec packets from unknown gateways is -possible but not strictly necessary.</p> - -<h2><a name="otherfilter">Other packet filters</a></h2> - -<p>When the IPsec gateway is also acting as your firewall, other packet -filtering rules will be in play. In general, those are outside the scope of -this document. See our <a href="web.html#firewall.linux">Linux firewall -links</a> for information. There are a few types of packet, however, which -can affect the operation of FreeS/WAN or of diagnostic tools commonly used -with it. These are discussed below.</p> - -<h3><a name="ICMP">ICMP filtering</a></h3> - -<p><a href="glossary.html#ICMP.gloss">ICMP</a> is the -<strong>I</strong>nternet <strong>C</strong>ontrol <strong>M</strong>essage -<strong>P</strong>rotocol. It is used for messages between IP implementations -themselves, whereas IP used is used between the clients of those -implementations. ICMP is, unsurprisingly, used for control messages. For -example, it is used to notify a sender that a desination is not reachable, or -to tell a router to reroute certain packets elsewhere.</p> - -<p>ICMP handling is tricky for firewalls.</p> -<ul> - <li>You definitely want some ICMP messages to get through; things won't - work without them. For example, your clients need to know if some - destination they ask for is unreachable.</li> - <li>On the other hand, you do equally definitely do not want untrusted folk - sending arbitrary control messages to your machines. Imagine what someone - moderately clever and moderately malicious could do to you, given control - of your network's routing.</li> -</ul> - -<p>ICMP does not use ports. Messages are distinguished by a "message type" -field and, for some types, by an additional "code" field. The definitive list -of types and codes is on the <a href="http://www.iana.org">IANA</a> site.</p> - -<p>One expert uses this definition for ICMP message types to be dropped at -the firewall.</p> -<pre># ICMP types which lack socially redeeming value. -# 5 Redirect -# 9 Router Advertisement -# 10 Router Selection -# 15 Information Request -# 16 Information Reply -# 17 Address Mask Request -# 18 Address Mask Reply - -badicmp='5 9 10 15 16 17 18'</pre> - -<p>A more conservative approach would be to make a list of allowed types and -drop everything else.</p> - -<p>Whichever way you do it, your ICMP filtering rules on a FreeS/WAN gateway -should allow at least the following ICMP packet types:</p> -<dl> - <dt>echo (type 8)</dt> - <dd></dd> - <dt>echo reply (type 0)</dt> - <dd>These are used by ping(1). We recommend allowing both types through - the tunnel and to or from your gateway's external interface, since - ping(1) is an essential testing tool. - <p>It is fairly common for firewalls to drop ICMP echo packets - addressed to machines behind the firewall. If that is your policy, - please create an exception for such packets arriving via an IPsec - tunnel, at least during intial testing of those tunnels.</p> - </dd> - <dt>destination unreachable (type 3)</dt> - <dd>This is used, with code 4 (Fragmentation Needed and Don't Fragment - was Set) in the code field, to control <a - href="glossary.html#pathMTU">path MTU discovery</a>. Since IPsec - processing adds headers, enlarges packets and may cause fragmentation, - an IPsec gateway should be able to send and receive these ICMP messages - <strong>on both inside and outside interfaces</strong>.</dd> -</dl> - -<h3><a name="traceroute">UDP packets for traceroute</a></h3> - -<p>The traceroute(1) utility uses UDP port numbers from 33434 to -approximately 33633. Generally, these should be allowed through for -troubleshooting.</p> - -<p>Some firewalls drop these packets to prevent outsiders exploring the -protected network with traceroute(1). If that is your policy, consider -creating an exception for such packets arriving via an IPsec tunnel, at least -during intial testing of those tunnels.</p> - -<h3><a name="l2tp">UDP for L2TP</a></h3> -<p> -Windows 2000 does, and products designed for compatibility with it may, build -<a href="glossary.html#L2TP">L2TP</a> tunnels over IPsec connections. - -<p>For this to work, you must allow UDP protocol 1701 packets coming out of -your tunnels to continue to their destination. You can, and probably should, -block such packets to or from your external interfaces, but allow them from -<var>ipsec0</var>.</p> - -<p>See also our Windows 2000 <a href="interop.html#win2k">interoperation -discussion</a>.</p> - -<h2><a name="packets">How it all works: IPsec packet details</a></h2> - -<p>IPsec uses three main types of packet:</p> -<dl> - <dt><a href="glossary.html#IKE">IKE</a> uses <strong>the UDP protocol and - port 500</strong>.</dt> - <dd>Unless you are using only (less secure, not recommended) manual - keying, you need IKE to negotiate connection parameters, acceptable - algorithms, key sizes and key setup. IKE handles everything required to - set up, rekey, repair or tear down IPsec connections.</dd> - <dt><a href="glossary.html#ESP">ESP</a> is <strong>protocol number - 50</strong></dt> - <dd>This is required for encrypted connections.</dd> - <dt><a href="glossary.html#AH">AH</a> is <strong>protocol number - 51</strong></dt> - <dd>This can be used where only authentication, not encryption, is - required.</dd> -</dl> - -<p>All of those packets should have appropriate IPsec gateway addresses in -both the to and from IP header fields. Firewall rules can check this if you -wish, though it is not strictly necessary. This is discussed in more detail -<a href="#unknowngate">later</a>.</p> - -<p>IPsec processing of incoming packets authenticates them then removes the -ESP or AH header and decrypts if necessary. Successful processing exposes an -inner packet which is then delivered back to the firewall machinery, marked -as having arrived on an <var>ipsec[0-3]</var> interface. Firewall rules can -use that interface label to distinguish these packets from unencrypted -packets which are labelled with the physical interface they arrived on (or -perhaps with a non-IPsec virtual interface such as <var>ppp0</var>).</p> - -<p>One of our users sent a mailing list message with a <a -href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/12/msg00006.html">diagram</a> -of the packet flow.</p> - -<h3><a name="noport">ESP and AH do not have ports</a></h3> - -<p>Some protocols, such as TCP and UDP, have the notion of ports. Others -protocols, including ESP and AH, do not. Quite a few IPsec newcomers have -become confused on this point. There are no ports <em>in</em> the ESP or AH -protocols, and no ports used <em>for</em> them. For these protocols, <em>the -idea of ports is completely irrelevant</em>.</p> - -<h3><a name="header">Header layout</a></h3> - -<p>The protocol numbers for ESP or AH are used in the 'next header' field of -the IP header. On most non-IPsec packets, that field would have one of:</p> -<ul> - <li>1 for ICMP</li> - <li>4 for IP-in-IP encapsulation</li> - <li>6 for TCP</li> - <li>17 for UDP</li> - <li>... or one of about 100 other possibilities listed by <a - href="http://www.iana.org">IANA</a></li> -</ul> - -<p>Each header in the sequence tells what the next header will be. IPsec adds -headers for ESP or AH near the beginning of the sequence. The original -headers are kept and the 'next header' fields adjusted so that all headers -can be correctly interpreted.</p> - -<p>For example, using <strong>[</strong> <strong>]</strong> to indicate data -protected by ESP and unintelligible to an eavesdropper between the -gateways:</p> -<ul> - <li>a simple packet might have only IP and TCP headers with: - <ul> - <li>IP header says next header --> TCP</li> - <li>TCP header port number --> which process to send data to</li> - <li>data</li> - </ul> - </li> - <li>with ESP <a href="glossary.html#transport">transport mode</a> - encapsulation, that packet would have: - <ul> - <li>IP header says next header --> ESP</li> - <li>ESP header <strong>[</strong> says next --> TCP</li> - <li>TCP header port number --> which process to send data to</li> - <li>data <strong>]</strong></li> - </ul> - Note that the IP header is outside ESP protection, visible to an - attacker, and that the final destination must be the gateway.</li> - <li>with ESP in <a href="glossary.html#tunnel">tunnel mode</a>, we might - have: - <ul> - <li>IP header says next header --> ESP</li> - <li>ESP header <strong>[</strong> says next --> IP</li> - <li>IP header says next header --> TCP</li> - <li>TCP header port number --> which process to send data to</li> - <li>data <strong>]</strong></li> - </ul> - Here the inner IP header is protected by ESP, unreadable by an attacker. - Also, the inner header can have a different IP address than the outer IP - header, so the decrypted packet can be routed from the IPsec gateway to a - final destination which may be another machine.</li> -</ul> - -<p>Part of the ESP header itself is encrypted, which is why the -<strong>[</strong> indicating protected data appears in the middle of some -lines above. The next header field of the ESP header is protected. This makes -<a href="glossary.html#traffic">traffic analysis</a> more difficult. The next -header field would tell an eavesdropper whether your packet was UDP to the -gateway, TCP to the gateway, or encapsulated IP. It is better not to give -this information away. A clever attacker may deduce some of it from the -pattern of packet sizes and timings, but we need not make it easy.</p> - -<p>IPsec allows various combinations of these to match local policies, -including combinations that use both AH and ESP headers or that nest multiple -copies of these headers.</p> - -<p>For example, suppose my employer has an IPsec VPN running between two -offices so all packets travelling between the gateways for those offices are -encrypted. If gateway policies allow it (The admins could block UDP 500 and -protocols 50 and 51 to disallow it), I can build an IPsec tunnel from my -desktop to a machine in some remote office. Those packets will have one ESP -header throughout their life, for my end-to-end tunnel. For part of the -route, however, they will also have another ESP layer for the corporate VPN's -encapsulation. The whole header scheme for a packet on the Internet might -be:</p> -<ul> - <li>IP header (with gateway address) says next header --> ESP</li> - <li>ESP header <strong>[</strong> says next --> IP</li> - <li>IP header (with receiving machine address) says next header --> - ESP</li> - <li>ESP header <strong>[</strong> says next --> TCP</li> - <li>TCP header port number --> which process to send data to</li> - <li>data <strong>]]</strong></li> -</ul> - -<p>The first ESP (outermost) header is for the corporate VPN. The inner ESP -header is for the secure machine-to-machine link.</p> - -<h3><a name="dhr">DHR on the updown script</a></h3> - -<p>Here are some mailing list comments from <a -href="manpage.d/ipsec_pluto.8.html">pluto(8)</a> developer Hugh Redelmeier on -an earlier draft of this document:</p> -<pre>There are many important things left out - -- firewalling is important but must reflect (implement) policy. Since - policy isn't the same for all our customers, and we're not experts, - we should concentrate on FW and MASQ interactions with FreeS/WAN. - -- we need a diagram to show packet flow WITHIN ONE MACHINE, assuming - IKE, IPsec, FW, and MASQ are all done on that machine. The flow is - obvious if the components are run on different machines (trace the - cables). - - IKE input: - + packet appears on public IF, as UDP port 500 - + input firewalling rules are applied (may discard) - + Pluto sees the packet. - - IKE output: - + Pluto generates the packet & writes to public IF, UDP port 500 - + output firewalling rules are applied (may discard) - + packet sent out public IF - - IPsec input, with encapsulated packet, outer destination of this host: - + packet appears on public IF, protocol 50 or 51. If this - packet is the result of decapsulation, it will appear - instead on the paired ipsec IF. - + input firewalling rules are applied (but packet is opaque) - + KLIPS decapsulates it, writes result to paired ipsec IF - + input firewalling rules are applied to resulting packet - as input on ipsec IF - + if the destination of the packet is this machine, the - packet is passed on to the appropriate protocol handler. - If the original packet was encapsulated more than once - and the new outer destination is this machine, that - handler will be KLIPS. - + otherwise: - * routing is done for the resulting packet. This may well - direct it into KLIPS for encoding or encrypting. What - happens then is described elsewhere. - * forwarding firewalling rules are applied - * output firewalling rules are applied - * the packet is sent where routing specified - - IPsec input, with encapsulated packet, outer destination of another host: - + packet appears on some IF, protocol 50 or 51 - + input firewalling rules are applied (but packet is opaque) - + routing selects where to send the packet - + forwarding firewalling rules are applied (but packet is opaque) - + packet forwarded, still encapsulated - - IPsec output, from this host or from a client: - + if from a client, input firewalling rules are applied as the - packet arrives on the private IF - + routing directs the packet to an ipsec IF (this is how the - system decides KLIPS processing is required) - + if from a client, forwarding firewalling rules are applied - + KLIPS eroute mechanism matches the source and destination - to registered eroutes, yielding a SPI group. This dictates - processing, and where the resulting packet is to be sent - (the destinations SG and the nexthop). - + output firewalling is not applied to the resulting - encapsulated packet - -- Until quite recently, KLIPS would double encapsulate packets that - didn't strictly need to be. Firewalling should be prepared for - those packets showing up as ESP and AH protocol input packets on - an ipsec IF. - -- MASQ processing seems to be done as if it were part of the - forwarding firewall processing (this should be verified). - -- If a firewall is being used, it is likely the case that it needs to - be adjusted whenever IPsec SAs are added or removed. Pluto invokes - a script to do this (and to adjust routing) at suitable times. The - default script is only suitable for ipfwadm-managed firewalls. Under - LINUX 2.2.x kernels, ipchains can be managed by ipfwadm (emulation), - but ipchains more powerful if manipulated using the ipchains command. - In this case, a custom updown script must be used. - - We think that the flexibility of ipchains precludes us supplying an - updown script that would be widely appropriate.</pre> -</body> -</html> diff --git a/doc/src/forwardingstate.txt b/doc/src/forwardingstate.txt deleted file mode 100644 index 8853ac84e..000000000 --- a/doc/src/forwardingstate.txt +++ /dev/null @@ -1,35 +0,0 @@ - - - .--------------. - | non-existant | - | policy | - `--------------' - | - | PF_ACQUIRE - | - |<---------. - V | new packet - .--------------. | (maybe resend PF_ACQUIRE) - | hold policy |--' - | |--. - `--------------' \ pass - | | \ msg .---------. - | | \ V | forward - | | .-------------. | packet - create | | | pass policy |--' - IPsec | | `-------------' - SA | | - | \ - | \ - V \ deny - .---------. \ msg - | encrypt | \ - | policy | \ ,---------. - `---------' \ | | discard - \ V | packet - .-------------. | - | deny policy |--' - '-------------' - - -$Id: forwardingstate.txt,v 1.1 2004/03/15 20:35:24 as Exp $ diff --git a/doc/src/glossary.html b/doc/src/glossary.html deleted file mode 100644 index 38d0db7bb..000000000 --- a/doc/src/glossary.html +++ /dev/null @@ -1,2257 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>FreeS/WAN glossary</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, glossary, cryptography"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: glossary.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1><a name="ourgloss">Glossary for the Linux FreeS/WAN project</a></h1> - -<p>Entries are in alphabetical order. Some entries are only one line or one -paragraph long. Others run to several paragraphs. I have tried to put the -essential information in the first paragraph so you can skip the other -paragraphs if that seems appropriate.</p> -<hr> - -<h2><a name="jump">Jump to a letter in the glossary</a></h2> - -<center> -<big><b><a href="#0">numeric</a> <a href="#A">A</a> <a href="#B">B</a> <a -href="#C">C</a> <a href="#D">D</a> <a href="#E">E</a> <a href="#F">F</a> <a -href="#G">G</a> <a href="#H">H</a> <a href="#I">I</a> <a href="#J">J</a> <a -href="#K">K</a> <a href="#L">L</a> <a href="#M">M</a> <a href="#N">N</a> <a -href="#O">O</a> <a href="#P">P</a> <a href="#Q">Q</a> <a href="#R">R</a> <a -href="#S">S</a> <a href="#T">T</a> <a href="#U">U</a> <a href="#V">V</a> <a -href="#W">W</a> <a href="#X">X</a> <a href="#Y">Y</a> <a -href="#Z">Z</a></b></big></center> -<hr> - -<h2><a name="gloss">Other glossaries</a></h2> - -<p>Other glossaries which overlap this one include:</p> -<ul> - <li>The VPN Consortium's glossary of <a - href="http://www.vpnc.org/terms.html">VPN terms</a>.</li> - <li>glossary portion of the <a - href="http://www.rsa.com/rsalabs/faq/B.html">Cryptography FAQ</a></li> - <li>an extensive crytographic glossary on <a - href="http://www.ciphersbyritter.com/GLOSSARY.HTM">Terry Ritter's</a> - page.</li> - <li>The <a href="#NSA">NSA</a>'s <a - href="http://www.sans.org/newlook/resources/glossary.htm">glossary of - computer security</a> on the <a href="http://www.sans.org">SANS - Institute</a> site.</li> - <li>a small glossary for Internet Security at <a - href="http://www5.zdnet.com/pcmag/pctech/content/special/glossaries/internetsecurity.html"> - PC magazine</a></li> - <li>The <a - href="http://www.visi.com/crypto/inet-crypto/glossary.html">glossary</a> - from Richard Smith's book <a href="#Smith">Internet Cryptography</a></li> -</ul> - -<p>Several Internet glossaries are available as RFCs:</p> -<ul> - <li><a href="http://www.rfc-editor.org/rfc/rfc1208.txt">Glossary of - Networking Terms</a></li> - <li><a href="http://www.rfc-editor.org/rfc/rfc1983.txt">Internet User's - Glossary</a></li> - <li><a href="http://www.rfc-editor.org/rfc/rfc2828.txt">Internet Security - Glossary</a></li> -</ul> - -<p>More general glossary or dictionary information:</p> -<ul> - <li>Free Online Dictionary of Computing (FOLDOC) - <ul> - <li><a href="http://www.nightflight.com/foldoc">North America</a></li> - <li><a - href="http://wombat.doc.ic.ac.uk/foldoc/index.html">Europe</a></li> - <li><a href="http://www.nue.org/foldoc/index.html">Japan</a></li> - </ul> - <p>There are many more mirrors of this dictionary.</p> - </li> - <li>The Jargon File, the definitive resource for hacker slang and folklore - <ul> - <li><a href="http://www.netmeg.net/jargon">North America</a></li> - <li><a href="http://info.wins.uva.nl/~mes/jargon/">Holland</a></li> - <li><a href="http://www.tuxedo.org/~esr/jargon">home page</a></li> - </ul> - <p>There are also many mirrors of this. See the home page for a list.</p> - </li> - <li>A general <a - href="http://www.trinity.edu/~rjensen/245glosf.htm#Navigate"> technology - glossary</a></li> - <li>An <a href="http://www.yourdictionary.com/">online dictionary resource - page</a> with pointers to many dictionaries for many languages</li> - <li>A <a href="http://www.onelook.com/">search engine</a> that accesses - several hundred online dictionaries</li> - <li>O'Reilly <a href="http://www.ora.com/reference/dictionary/">Dictionary - of PC Hardware and Data Communications Terms</a></li> - <li><a href="http://www.FreeSoft.org/CIE/index.htm">Connected</a> Internet - encyclopedia</li> - <li><a href="http://www.whatis.com/">whatis.com</a></li> -</ul> -<hr> - -<h2><a name="definitions">Definitions</a></h2> -<dl> - <dt><a name="0">0</a></dt> - <dt><a name="3DES">3DES (Triple DES)</a></dt> - <dd>Using three <a href="#DES">DES</a> encryptions on a single data - block, with at least two different keys, to get higher security than is - available from a single DES pass. The three-key version of 3DES is the - default encryption algorithm for <a href="#FreeSWAN">Linux - FreeS/WAN</a>. - <p><a href="#IPSEC">IPsec</a> always does 3DES with three different - keys, as required by RFC 2451. For an explanation of the two-key - variant, see <a href="#2key">two key triple DES</a>. Both use an <a - href="#EDE">EDE</a> encrypt-decrypt-encrpyt sequence of operations.</p> - <p>Single <a href="#DES">DES</a> is <a - href="politics.html#desnotsecure">insecure</a>.</p> - <p>Double DES is ineffective. Using two 56-bit keys, one might expect - an attacker to have to do 2<sup>112</sup> work to break it. In fact, - only 2<sup>57</sup> work is required with a <a - href="#meet">meet-in-the-middle attack</a>, though a large amount of - memory is also required. Triple DES is vulnerable to a similar attack, - but that just reduces the work factor from the 2<sup>168</sup> one - might expect to 2<sup>112</sup>. That provides adequate protection - against <a href="#brute">brute force</a> attacks, and no better attack - is known.</p> - <p>3DES can be somewhat slow compared to other ciphers. It requires - three DES encryptions per block. DES was designed for hardware - implementation and includes some operations which are difficult in - software. However, the speed we get is quite acceptable for many uses. - See our <a href="performance.html">performance</a> document for - details.</p> - </dd> - <dt><a name="A">A</a></dt> - <dt><a name="active">Active attack</a></dt> - <dd>An attack in which the attacker does not merely eavesdrop (see <a - href="#passive">passive attack</a>) but takes action to change, delete, - reroute, add, forge or divert data. Perhaps the best-known active - attack is <a href="#middle">man-in-the-middle</a>. In general, <a - href="#authentication">authentication</a> is a useful defense against - active attacks.</dd> - <dt><a name="AES">AES</a></dt> - <dd>The <b>A</b>dvanced <b>E</b>ncryption <b>S</b>tandard -- a new <a - href="#block">block cipher</a> standard to replace <a - href="politics.html#desnotsecure">DES</a> -- developed by <a - href="#NIST">NIST</a>, the US National Institute of Standards and - Technology. DES used 64-bit blocks and a 56-bit key. AES ciphers use a - 128-bit block and 128, 192 or 256-bit keys. The larger block size helps - resist <a href="#birthday">birthday attacks</a> while the large key - size prevents <a href="#brute">brute force attacks</a>. - <p>Fifteen proposals meeting NIST's basic criteria were submitted in - 1998 and subjected to intense discussion and analysis, "round one" - evaluation. In August 1999, NIST narrowed the field to five "round two" - candidates:</p> - <ul> - <li><a href="http://www.research.ibm.com/security/mars.html">Mars</a> - from IBM</li> - <li><a href="http://www.rsa.com/rsalabs/aes/">RC6</a> from RSA</li> - <li><a - href="http://www.esat.kuleuven.ac.be/~rijmen/rijndael/">Rijndael</a> - from two Belgian researchers</li> - <li><a - href="http://www.cl.cam.ac.uk/~rja14/serpent.html">Serpent</a>, a - British-Norwegian-Israeli collaboration</li> - <li><a href="http://www.counterpane.com/twofish.html">Twofish</a> - from the consulting firm <a - href="http://www.counterpane.com">Counterpane</a></li> - </ul> - <p>Three of the five finalists -- Rijndael, Serpent and Twofish -- have - completely open licenses.</p> - <p>In October 2000, NIST announced the winner -- Rijndael.</p> - <p>For more information, see:</p> - <ul> - <li>NIST's <a - href="http://csrc.nist.gov/encryption/aes/aes_home.htm">AES home - page</a></li> - <li>the Block Cipher Lounge <a - href="http://www.ii.uib.no/~larsr/aes.html">AES page</a></li> - <li>Brian Gladman's <a - href="http://fp.gladman.plus.com/cryptography_technology/index.htm">code - and benchmarks</a></li> - <li>Helger Lipmaa's <a - href="http://www.tcs.hut.fi/~helger/aes/">survey of - implementations</a></li> - </ul> - <p>AES will be added to a future release of <a href="#FreeSWAN">Linux - FreeS/WAN</a>. Likely we will add all three of the finalists with good - licenses. User-written <a href="web.html#patch">AES patches</a> are - already available.</p> - <p>Adding AES may also require adding stronger hashes, <a - href="#SHA-256">SHA-256, SHA-384 and SHA-512</a>.</p> - </dd> - <dt><a name="AH">AH</a></dt> - <dd>The <a href="#IPSEC">IPsec</a> <b>A</b>uthentication <b>H</b>eader, - added after the IP header. For details, see our <a - href="ipsec.html#AH.ipsec">IPsec</a> document and/or RFC 2402.</dd> - <dt><a name="alicebob">Alice and Bob</a></dt> - <dd>A and B, the standard example users in writing on cryptography and - coding theory. Carol and Dave join them for protocols which require - more players. - <p>Bruce Schneier extends these with many others such as Eve the - Eavesdropper and Victor the Verifier. His extensions seem to be in the - process of becoming standard as well. See page 23 of <a - href="biblio.html#schneier">Applied Cryptography</a></p> - <p>Alice and Bob have an amusing <a - href="http://www.conceptlabs.co.uk/alicebob.html"> biography</a> on the - web.</p> - </dd> - <dt>ARPA</dt> - <dd>see <a href="#DARPA">DARPA</a></dd> - <dt><a name="ASIO">ASIO</a></dt> - <dd>Australian Security Intelligence Organisation.</dd> - <dt>Asymmetric cryptography</dt> - <dd>See <a href="#public">public key cryptography</a>.</dd> - <dt><a name="authentication">Authentication</a></dt> - <dd>Ensuring that a message originated from the expected sender and has - not been altered on route. <a href="#IPSEC">IPsec</a> uses - authentication in two places: - <ul> - <li>peer authentication, authenticating the players in <a - href="#IKE">IKE</a>'s <a href="#DH">Diffie-Hellman</a> key - exchanges to prevent <a href="#middle">man-in-the-middle - attacks</a>. This can be done in a number of ways. The methods - supported by FreeS/WAN are discussed in our <a - href="adv_config.html#choose">advanced configuration</a> - document.</li> - <li>packet authentication, authenticating packets on an established - <a href="#SA">SA</a>, either with a separate <a - href="#AH">authentication header</a> or with the optional - authentication in the <a href="#ESP">ESP</a> protocol. In either - case, packet authentication uses a <a href="#HMAC">hashed message - athentication code</a> technique.</li> - </ul> - <p>Outside IPsec, passwords are perhaps the most common authentication - mechanism. Their function is essentially to authenticate the person's - identity to the system. Passwords are generally only as secure as the - network they travel over. If you send a cleartext password over a - tapped phone line or over a network with a packet sniffer on it, the - security provided by that password becomes zero. Sending an encrypted - password is no better; the attacker merely records it and reuses it at - his convenience. This is called a <a href="#replay">replay</a> - attack.</p> - <p>A common solution to this problem is a <a - href="#challenge">challenge-response</a> system. This defeats simple - eavesdropping and replay attacks. Of course an attacker might still try - to break the cryptographic algorithm used, or the <a - href="#random">random number</a> generator.</p> - </dd> - <dt><a name="auto">Automatic keying</a></dt> - <dd>A mode in which keys are automatically generated at connection - establisment and new keys automaically created periodically thereafter. - Contrast with <a href="#manual">manual keying</a> in which a single - stored key is used. - <p>IPsec uses the <a href="#DH">Diffie-Hellman key exchange - protocol</a> to create keys. An <a - href="#authentication">authentication</a> mechansim is required for - this. FreeS/WAN normally uses <a href="#RSA">RSA</a> for this. Other - methods supported are discussed in our <a - href="adv_config.html#choose">advanced configuration</a> document.</p> - <p>Having an attacker break the authentication is emphatically not a - good idea. An attacker that breaks authentication, and manages to - subvert some other network entities (DNS, routers or gateways), can use - a <a href="#middle">man-in-the middle attack</a> to break the security - of your IPsec connections.</p> - <p>However, having an attacker break the authentication in automatic - keying is not quite as bad as losing the key in manual keying.</p> - <ul> - <li>An attacker who reads /etc/ipsec.conf and gets the keys for a - manually keyed connection can, without further effort, read all - messages encrypted with those keys, including any old messages he - may have archived.</li> - <li>Automatic keying has a property called <a href="#PFS">perfect - forward secrecy</a>. An attacker who breaks the authentication gets - none of the automatically generated keys and cannot immediately - read any messages. He has to mount a successful <a - href="#middle">man-in-the-middle attack</a> in real time before he - can read anything. He cannot read old archived messages at all and - will not be able to read any future messages not caught by - man-in-the-middle tricks.</li> - </ul> - <p>That said, the secrets used for authentication, stored in <a - href="manpage.d/ipsec.secrets.5.html">ipsec.secrets(5)</a>, should - still be protected as tightly as cryptographic keys.</p> - </dd> - <dt><a name="B">B</a></dt> - <dt><a href="http://www.nortelnetworks.com">Bay Networks</a></dt> - <dd>A vendor of routers, hubs and related products, now a subsidiary of - Nortel. Interoperation between their IPsec products and Linux FreeS/WAN - was problematic at last report; see our <a - href="interop.html#bay">interoperation</a> section.</dd> - <dt><a name="benchmarks">benchmarks</a></dt> - <dd>Our default block cipher, <a href="#3DES">triple DES</a>, is slower - than many alternate ciphers that might be used. Speeds achieved, - however, seem adequate for many purposes. For example, the assembler - code from the <a href="#LIBDES">LIBDES</a> library we use encrypts 1.6 - megabytes per second on a Pentium 200, according to the test program - supplied with the library. - <p>For more detail, see our document on <a - href="performance.html">FreeS/WAN performance</a>.</p> - </dd> - <dt><a name="BIND">BIND</a></dt> - <dd><b>B</b>erkeley <b>I</b>nternet <b>N</b>ame <b>D</b>aemon, a widely - used implementation of <a href="#DNS">DNS</a> (Domain Name Service). - See our bibliography for a <a href="#DNS">useful reference</a>. See the - <a href="http://www.isc.org/bind.html">BIND home page</a> for more - information and the latest version.</dd> - <dt><a name="birthday">Birthday attack</a></dt> - <dd>A cryptographic attack based on the mathematics exemplified by the <a - href="#paradox">birthday paradox</a>. This math turns up whenever the - question of two cryptographic operations producing the same result - becomes an issue: - <ul> - <li><a href="#collision">collisions</a> in <a href="#digest">message - digest</a> functions.</li> - <li>identical output blocks from a <a href="#block">block - cipher</a></li> - <li>repetition of a challenge in a <a - href="#challenge">challenge-response</a> system</li> - </ul> - <p>Resisting such attacks is part of the motivation for:</p> - <ul> - <li>hash algorithms such as <a href="#SHA">SHA</a> and <a - href="#RIPEMD">RIPEMD-160</a> giving a 160-bit result rather than - the 128 bits of <a href="#MD4">MD4</a>, <a href="#MD5">MD5</a> and - <a href="#RIPEMD">RIPEMD-128</a>.</li> - <li><a href="#AES">AES</a> block ciphers using a 128-bit block - instead of the 64-bit block of most current ciphers</li> - <li><a href="#IPSEC">IPsec</a> using a 32-bit counter for packets - sent on an <a href="#auto">automatically keyed</a> <a - href="#SA">SA</a> and requiring that the connection always be - rekeyed before the counter overflows.</li> - </ul> - </dd> - <dt><a name="paradox">Birthday paradox</a></dt> - <dd>Not really a paradox, just a rather counter-intuitive mathematical - fact. In a group of 23 people, the chance of a least one pair having - the same birthday is over 50%. - <p>The second person has 1 chance in 365 (ignoring leap years) of - matching the first. If they don't match, the third person's chances of - matching one of them are 2/365. The 4th, 3/365, and so on. The total of - these chances grows more quickly than one might guess.</p> - </dd> - <dt><a name="block">Block cipher</a></dt> - <dd>A <a href="#symmetric">symmetric cipher</a> which operates on - fixed-size blocks of plaintext, giving a block of ciphertext for each. - Contrast with <a href="#stream"> stream cipher</a>. Block ciphers can - be used in various <a href="#mode">modes</a> when multiple block are to - be encrypted. - <p><a href="#DES">DES</a> is among the the best known and widely used - block ciphers, but is now obsolete. Its 56-bit key size makes it <a - href="#desnotsecure">highly insecure</a> today. <a href="#3DES">Triple - DES</a> is the default block cipher for <a href="#FreeSWAN">Linux - FreeS/WAN</a>.</p> - <p>The current generation of block ciphers -- such as <a - href="#Blowfish">Blowfish</a>, <a href="#CAST128">CAST-128</a> and <a - href="#IDEA">IDEA</a> -- all use 64-bit blocks and 128-bit keys. The - next generation, <a href="#AES">AES</a>, uses 128-bit blocks and - supports key sizes up to 256 bits.</p> - <p>The <a href="http://www.ii.uib.no/~larsr/bc.html"> Block Cipher - Lounge</a> web site has more information.</p> - </dd> - <dt><a name="Blowfish">Blowfish</a></dt> - <dd>A <a href="#block">block cipher</a> using 64-bit blocks and keys of - up to 448 bits, designed by <a href="#schneier">Bruce Schneier</a> and - used in several products. - <p>This is not required by the <a href="#IPSEC">IPsec</a> RFCs and not - currently used in <a href="#FreeSWAN">Linux FreeS/WAN</a>.</p> - </dd> - <dt><a name="brute">Brute force attack (exhaustive search)</a></dt> - <dd>Breaking a cipher by trying all possible keys. This is always - possible in theory (except against a <a href="#OTP">one-time pad</a>), - but it becomes practical only if the key size is inadequate. For an - important example, see our document on the <a - href="#desnotsecure">insecurity of DES</a> with its 56-bit key. For an - analysis of key sizes required to resist plausible brute force attacks, - see <a href="http://www.counterpane.com/keylength.html">this paper</a>. - <p>Longer keys protect against brute force attacks. Each extra bit in - the key doubles the number of possible keys and therefore doubles the - work a brute force attack must do. A large enough key defeats - <strong>any</strong> brute force attack.</p> - <p>For example, the EFF's <a href="#EFF">DES Cracker</a> searches a - 56-bit key space in an average of a few days. Let us assume an attacker - that can find a 64-bit key (256 times harder) by brute force search in - a second (a few hundred thousand times faster). For a 96-bit key, that - attacker needs 2<sup>32</sup> seconds, about 135 years. Against a - 128-bit key, he needs 2<sup>32</sup> times that, over 500,000,000,000 - years. Your data is then obviously secure against brute force attacks. - Even if our estimate of the attacker's speed is off by a factor of a - million, it still takes him over 500,000 years to crack a message.</p> - <p>This is why</p> - <ul> - <li>single <a href="#DES">DES</a> is now considered <a - href="#desnotsecure">dangerously insecure</a></li> - <li>all of the current generation of <a href="#block">block - ciphers</a> use a 128-bit or longer key</li> - <li><a href="#AES">AES</a> ciphers support keysizes 128, 192 and 256 - bits</li> - <li>any cipher we add to Linux FreeS/WAN will have <em>at least</em> - a 128-bit key</li> - </ul> - <p><strong>Cautions:</strong><br> - <em>Inadequate keylength always indicates a weak cipher</em> but it is - important to note that <em>adequate keylength does not necessarily - indicate a strong cipher</em>. There are many attacks other than brute - force, and adequate keylength <em>only</em> guarantees resistance to - brute force. Any cipher, whatever its key size, will be weak if design - or implementation flaws allow other attacks.</p> - <p>Also, <em>once you have adequate keylength</em> (somewhere around 90 - or 100 bits), <em>adding more key bits make no practical - difference</em>, even against brute force. Consider our 128-bit example - above that takes 500,000,000,000 years to break by brute force. We - really don't care how many zeroes there are on the end of that, as long - as the number remains ridiculously large. That is, we don't care - exactly how large the key is as long as it is large enough.</p> - <p>There may be reasons of convenience in the design of the cipher to - support larger keys. For example <a href="#Blowfish">Blowfish</a> - allows up to 448 bits and <a href="#RC4">RC4</a> up to 2048, but beyond - 100-odd bits it makes no difference to practical security.</p> - </dd> - <dt>Bureau of Export Administration</dt> - <dd>see <a href="#BXA">BXA</a></dd> - <dt><a name="BXA">BXA</a></dt> - <dd>The US Commerce Department's <b>B</b>ureau of E<b>x</b>port - <b>A</b>dministration which administers the <a href="#EAR">EAR</a> - Export Administration Regulations controling the export of, among other - things, cryptography.</dd> - <dt><a name="C">C</a></dt> - <dt><a name="CA">CA</a></dt> - <dd><b>C</b>ertification <b>A</b>uthority, an entity in a <a - href="#PKI">public key infrastructure</a> that can certify keys by - signing them. Usually CAs form a hierarchy. The top of this hierarchy - is called the <a href="#rootCA">root CA</a>. - <p>See <a href="#web">Web of Trust</a> for an alternate model.</p> - </dd> - <dt><a name="CAST128">CAST-128</a></dt> - <dd>A <a href="#block">block cipher</a> using 64-bit blocks and 128-bit - keys, described in RFC 2144 and used in products such as <a - href="#Entrust">Entrust</a> and recent versions of <a - href="#PGP">PGP</a>. - <p>This is not required by the <a href="#IPSEC">IPsec</a> RFCs and not - currently used in <a href="#FreeSWAN">Linux FreeS/WAN</a>.</p> - </dd> - <dt>CAST-256</dt> - <dd><a href="#Entrust">Entrust</a>'s candidate cipher for the <a - href="#AES">AES standard</a>, largely based on the <a - href="#CAST128">CAST-128</a> design.</dd> - <dt><a name="CBC">CBC mode</a></dt> - <dd><b>C</b>ipher <b>B</b>lock <b>C</b>haining <a href="#mode">mode</a>, - a method of using a <a href="#block">block cipher</a> in which for each - block except the first, the result of the previous encryption is XORed - into the new block before it is encrypted. CBC is the mode used in <a - href="#IPSEC">IPsec</a>. - <p>An <a href="#IV">initialisation vector</a> (IV) must be provided. It - is XORed into the first block before encryption. The IV need not be - secret but should be different for each message and unpredictable.</p> - </dd> - <dt><a name="CIDR">CIDR</a></dt> - <dd><b>C</b>lassless <b>I</b>nter-<b>D</b>omain <b>R</b>outing, - an addressing scheme used to describe networks not - restricted to the old Class A, B, and C sizes. - A CIDR block is written - <VAR>address</VAR>/<VAR>mask</VAR>, where <VAR>address</VAR> is - a 32-bit Internet address. - The first <VAR>mask</VAR> bits of <VAR>address</VAR> - are part of the gateway address, while the remaining bits designate - other host addresses. - For example, the CIDR block 192.0.2.96/27 describes a network with - gateway - 192.0.2.96, hosts 192.0.2.96 through 192.0.2.126 and broadcast - 192.0.2.127. - <p>FreeS/WAN policy group files accept CIDR blocks of the format - <VAR>address</VAR>/[<VAR>mask</VAR>], where <VAR>address</VAR> may - take the form <VAR>name.domain.tld</VAR>. An absent <VAR>mask</VAR> - is assumed to be /32. - </p> - </dd> - - <dt>Certification Authority</dt> - <dd>see <a href="#CA">CA</a></dd> - <dt><a name="challenge">Challenge-response authentication</a></dt> - <dd>An <a href="#authentication">authentication</a> system in which one - player generates a <a href="#random">random number</a>, encrypts it and - sends the result as a challenge. The other player decrypts and sends - back the result. If the result is correct, that proves to the first - player that the second player knew the appropriate secret, required for - the decryption. Variations on this technique exist using <a - href="#public">public key</a> or <a href="#symmetric">symmetric</a> - cryptography. Some provide two-way authentication, assuring each player - of the other's identity. - <p>This is more secure than passwords against two simple attacks:</p> - <ul> - <li>If cleartext passwords are sent across the wire (e.g. for - telnet), an eavesdropper can grab them. The attacker may even be - able to break into other systems if the user has chosen the same - password for them.</li> - <li>If an encrypted password is sent, an attacker can record the - encrypted form and use it later. This is called a replay - attack.</li> - </ul> - <p>A challenge-response system never sends a password, either cleartext - or encrypted. An attacker cannot record the response to one challenge - and use it as a response to a later challenge. The random number is - different each time.</p> - <p>Of course an attacker might still try to break the cryptographic - algorithm used, or the <a href="#random">random number</a> - generator.</p> - </dd> - <dt><a name="mode">Cipher Modes</a></dt> - <dd>Different ways of using a block cipher when encrypting multiple - blocks. - <p>Four standard modes were defined for <a href="#DES">DES</a> in <a - href="#FIPS">FIPS</a> 81. They can actually be applied with any block - cipher.</p> - - <table> - <tbody> - <tr> - <td></td> - <td><a href="#ECB">ECB</a></td> - <td>Electronic CodeBook</td> - <td>encrypt each block independently</td> - </tr> - <tr> - <td></td> - <td><a href="#CBC">CBC</a></td> - <td>Cipher Block Chaining<br> - </td> - <td>XOR previous block ciphertext into new block plaintext before - encrypting new block</td> - </tr> - <tr> - <td></td> - <td>CFB</td> - <td>Cipher FeedBack</td> - <td></td> - </tr> - <tr> - <td></td> - <td>OFB</td> - <td>Output FeedBack</td> - <td></td> - </tr> - </tbody> - </table> - <p><a href="#IPSEC">IPsec</a> uses <a href="#CBC">CBC</a> mode since - this is only marginally slower than <a href="#ECB">ECB</a> and is more - secure. In ECB mode the same plaintext always encrypts to the same - ciphertext, unless the key is changed. In CBC mode, this does not - occur.</p> - <p>Various other modes are also possible, but none of them are used in - IPsec.</p> - </dd> - <dt><a name="ciphertext">Ciphertext</a></dt> - <dd>The encrypted output of a cipher, as opposed to the unencrypted <a - href="#plaintext">plaintext</a> input.</dd> - <dt><a href="http://www.cisco.com">Cisco</a></dt> - <dd>A vendor of routers, hubs and related products. Their IPsec products - interoperate with Linux FreeS/WAN; see our <a - href="interop.html#Cisco">interop</a> section.</dd> - <dt><a name="client">Client</a></dt> - <dd>This term has at least two distinct uses in discussing IPsec: - <ul> - <li>The <strong>clients of an IPsec gateway</strong> are the machines - it protects, typically on one or more subnets behind the gateway. - In this usage, all the machines on an office network are clients of - that office's IPsec gateway. Laptop or home machines connecting to - the office, however, are <em>not</em> clients of that gateway. They - are remote gateways, running the other end of an IPsec connection. - Each of them is also its own client.</li> - <li><strong>IPsec client software</strong> is used to describe - software which runs on various standalone machines to let them - connect to IPsec networks. In this usage, a laptop or home machine - connecting to the office is a client, and the office gateway is the - server.</li> - </ul> - <p>We generally use the term in the first sense. Vendors of Windows - IPsec solutions often use it in the second. See this <a - href="interop.html#client.server">discussion</a>.</p> - </dd> - <dt><a name="cc">Common Criteria</a></dt> - <dd>A set of international security classifications which are replacing - the old US <a href="#rainbow">Rainbow Book</a> standards and similar - standards in other countries. - <p>Web references include this <a href="http://csrc.nist.gov/cc">US - government site</a> and this <a - href="http://www.commoncriteria.org">global home page</a>.</p> - </dd> - <dt>Conventional cryptography</dt> - <dd>See <a href="#symmetric">symmetric cryptography</a></dd> - <dt><a name="collision">Collision resistance</a></dt> - <dd>The property of a <a href="#digest">message digest</a> algorithm - which makes it hard for an attacker to find or construct two inputs - which hash to the same output.</dd> - <dt>Copyleft</dt> - <dd>see GNU <a href="#GPL">General Public License</a></dd> - <dt><a name="CSE">CSE</a></dt> - <dd><a href="http://www.cse-cst.gc.ca/">Communications Security - Establishment</a>, the Canadian organisation for <a - href="#SIGINT">signals intelligence</a>.</dd> - <dt><a name="D">D</a></dt> - <dt><a name="DARPA">DARPA (sometimes just ARPA)</a></dt> - <dd>The US government's <b>D</b>efense <b>A</b>dvanced <b>R</b>esearch - <b>P</b>rojects <b>A</b>gency. Projects they have funded over the years - have included the Arpanet which evolved into the Internet, the TCP/IP - protocol suite (as a replacement for the original Arpanet suite), the - Berkeley 4.x BSD Unix projects, and <a href="#SDNS">Secure DNS</a>. - <p>For current information, see their <a - href="http://www.darpa.mil/ito">web site</a>.</p> - </dd> - <dt><a name="DOS">Denial of service (DoS) attack</a></dt> - <dd>An attack that aims at denying some service to legitimate users of a - system, rather than providing a service to the attacker. - <ul> - <li>One variant is a flooding attack, overwhelming the system with - too many packets, to much email, or whatever.</li> - <li>A closely related variant is a resource exhaustion attack. For - example, consider a "TCP SYN flood" attack. Setting up a TCP - connection involves a three-packet exchange: - <ul> - <li>Initiator: Connection please (SYN)</li> - <li>Responder: OK (ACK)</li> - <li>Initiator: OK here too</li> - </ul> - <p>If the attacker puts bogus source information in the first - packet, such that the second is never delivered, the responder may - wait a long time for the third to come back. If responder has - already allocated memory for the connection data structures, and if - many of these bogus packets arrive, the responder may run out of - memory.</p> - </li> - <li>Another variant is to feed the system undigestible data, hoping - to make it sick. For example, IP packets are limited in size to 64K - bytes and a fragment carries information on where it starts within - that 64K and how long it is. The "ping of death" delivers fragments - that say, for example, that they start at 60K and are 20K long. - Attempting to re-assemble these without checking for overflow can - be fatal.</li> - </ul> - <p>The two example attacks discussed were both quite effective when - first discovered, capable of crashing or disabling many operating - systems. They were also well-publicised, and today far fewer systems - are vulnerable to them.</p> - </dd> - <dt><a name="DES">DES</a></dt> - <dd>The <b>D</b>ata <b>E</b>ncryption <b>S</b>tandard, a <a - href="#block">block cipher</a> with 64-bit blocks and a 56-bit key. - Probably the most widely used <a href="#symmetric">symmetric cipher</a> - ever devised. DES has been a US government standard for their own use - (only for unclassified data), and for some regulated industries such as - banking, since the late 70's. It is now being replaced by <a - href="#AES">AES</a>. - <p><a href="politics.html#desnotsecure">DES is seriously insecure - against current attacks.</a></p> - <p><a href="#FreeSWAN">Linux FreeS/WAN</a> does not include DES, even - though the RFCs specify it. <b>We strongly recommend that single DES - not be used.</b></p> - <p>See also <a href="#3DES">3DES</a> and <a href="#DESX">DESX</a>, - stronger ciphers based on DES.</p> - </dd> - <dt><a name="DESX">DESX</a></dt> - <dd>An improved <a href="#DES">DES</a> suggested by Ron Rivest of RSA - Data Security. It XORs extra key material into the text before and - after applying the DES cipher. - <p>This is not required by the <a href="#IPSEC">IPsec</a> RFCs and not - currently used in <a href="#FreeSWAN">Linux FreeS/WAN</a>. DESX would - be the easiest additional transform to add; there would be very little - code to write. It would be much faster than 3DES and almost certainly - more secure than DES. However, since it is not in the RFCs other IPsec - implementations cannot be expected to have it.</p> - </dd> - <dt>DH</dt> - <dd>see <a href="#DH">Diffie-Hellman</a></dd> - <dt><a name="DHCP">DHCP</a></dt> - <dd><strong>D</strong>ynamic <strong>H</strong>ost - <strong>C</strong>onfiguration <strong>P</strong>rotocol, a method of - assigning <a href="#dynamic">dynamic IP addresses</a>, and providing - additional information such as addresses of DNS servers and of - gateways. See this <a href="http://www.dhcp.org">DHCP resource - page.</a></dd> - <dt><a name="DH">Diffie-Hellman (DH) key exchange protocol</a></dt> - <dd>A protocol that allows two parties without any initial shared secret - to create one in a manner immune to eavesdropping. Once they have done - this, they can communicate privately by using that shared secret as a - key for a block cipher or as the basis for key exchange. - <p>The protocol is secure against all <a href="#passive">passive - attacks</a>, but it is not at all resistant to active <a - href="#middle">man-in-the-middle attacks</a>. If a third party can - impersonate Bob to Alice and vice versa, then no useful secret can be - created. Authentication of the participants is a prerequisite for safe - Diffie-Hellman key exchange. IPsec can use any of several <a - href="#authentication">authentication</a> mechanisims. Those supported - by FreeS/WAN are discussed in our <a - href="config.html#choose">configuration</a> section.</p> - <p>The Diffie-Hellman key exchange is based on the <a - href="#dlog">discrete logarithm</a> problem and is secure unless - someone finds an efficient solution to that problem.</p> - <p>Given a prime <var>p</var> and generator <var>g</var> (explained - under <a href="#dlog">discrete log</a> below), Alice:</p> - <ul> - <li>generates a random number <var>a</var></li> - <li>calculates <var>A = g^a modulo p</var></li> - <li>sends <var>A</var> to Bob</li> - </ul> - <p>Meanwhile Bob:</p> - <ul> - <li>generates a random number <var>b</var></li> - <li>calculates <var>B = g^b modulo p</var></li> - <li>sends <var>B</var> to Alice</li> - </ul> - <p>Now Alice and Bob can both calculate the shared secret <var>s = - g^(ab)</var>. Alice knows <var>a</var> and <var>B</var>, so she - calculates <var>s = B^a</var>. Bob knows <var>A</var> and <var>b</var> - so he calculates <var>s = A^b</var>.</p> - <p>An eavesdropper will know <var>p</var> and <var>g</var> since these - are made public, and can intercept <var>A</var> and <var>B</var> but, - short of solving the <a href="#dlog">discrete log</a> problem, these do - not let him or her discover the secret <var>s</var>.</p> - </dd> - <dt><a name="signature">Digital signature</a></dt> - <dd>Sender: - <ul> - <li>calculates a <a href="#digest">message digest</a> of a - document</li> - <li>encrypts the digest with his or her private key, using some <a - href="#public">public key cryptosystem</a>.</li> - <li>attaches the encrypted digest to the document as a signature</li> - </ul> - <p>Receiver:</p> - <ul> - <li>calculates a digest of the document (not including the - signature)</li> - <li>decrypts the signature with the signer's public key</li> - <li>verifies that the two results are identical</li> - </ul> - <p>If the public-key system is secure and the verification succeeds, - then the receiver knows</p> - <ul> - <li>that the document was not altered between signing and - verification</li> - <li>that the signer had access to the private key</li> - </ul> - <p>Such an encrypted message digest can be treated as a signature since - it cannot be created without <em>both</em> the document <em>and</em> - the private key which only the sender should possess. The <a - href="web.html#legal">legal issues</a> are complex, but several - countries are moving in the direction of legal recognition for digital - signatures.</p> - </dd> - <dt><a name="dlog">discrete logarithm problem</a></dt> - <dd>The problem of finding logarithms in a finite field. Given a field - defintion (such definitions always include some operation analogous to - multiplication) and two numbers, a base and a target, find the power - which the base must be raised to in order to yield the target. - <p>The discrete log problem is the basis of several cryptographic - systems, including the <a href="#DH">Diffie-Hellman</a> key exchange - used in the <a href="#IKE">IKE</a> protocol. The useful property is - that exponentiation is relatively easy but the inverse operation, - finding the logarithm, is hard. The cryptosystems are designed so that - the user does only easy operations (exponentiation in the field) but an - attacker must solve the hard problem (discrete log) to crack the - system.</p> - <p>There are several variants of the problem for different types of - field. The IKE/Oakley key determination protocol uses two variants, - either over a field modulo a prime or over a field defined by an - elliptic curve. We give an example modulo a prime below. For the - elliptic curve version, consult an advanced text such as <a - href="biblio.html#handbook">Handbook of Applied Cryptography</a>.</p> - <p>Given a prime <var>p</var>, a generator <var>g</var> for the field - modulo that prime, and a number <var>x</var> in the field, the problem - is to find <var>y</var> such that <var>g^y = x</var>.</p> - <p>For example, let p = 13. The field is then the integers from 0 to - 12. Any integer equals one of these modulo 13. That is, the remainder - when any integer is divided by 13 must be one of these.</p> - <p>2 is a generator for this field. That is, the powers of two modulo - 13 run through all the non-zero numbers in the field. Modulo 13 we - have:</p> - <pre> y x - 2^0 == 1 - 2^1 == 2 - 2^2 == 4 - 2^3 == 8 - 2^4 == 3 that is, the remainder from 16/13 is 3 - 2^5 == 6 the remainder from 32/13 is 6 - 2^6 == 12 and so on - 2^7 == 11 - 2^8 == 9 - 2^9 == 5 - 2^10 == 10 - 2^11 == 7 - 2^12 == 1</pre> - <p>Exponentiation in such a field is not difficult. Given, say, - <nobr><var>y = 11</var>,</nobr>calculating <nobr><var>x = - 7</var></nobr>is straightforward. One method is just to calculate - <nobr><var>2^11 = 2048</var>,</nobr>then <nobr><var>2048 mod 13 == - 7</var>.</nobr>When the field is modulo a large prime (say a few 100 - digits) you need a silghtly cleverer method and even that is moderately - expensive in computer time, but the calculation is still not - problematic in any basic way.</p> - <p>The discrete log problem is the reverse. In our example, given - <nobr><var>x = 7</var>,</nobr>find the logarithm <nobr><var>y = - 11</var>.</nobr>When the field is modulo a large prime (or is based on - a suitable elliptic curve), this is indeed problematic. No solution - method that is not catastrophically expensive is known. Quite a few - mathematicians have tackled this problem. No efficient method has been - found and mathematicians do not expect that one will be. It seems - likely no efficient solution to either of the main variants the - discrete log problem exists.</p> - <p>Note, however, that no-one has proven such methods do not exist. If - a solution to either variant were found, the security of any crypto - system using that variant would be destroyed. This is one reason <a - href="#IKE">IKE</a> supports two variants. If one is broken, we can - switch to the other.</p> - </dd> - <dt><a name="discretionary">discretionary access control</a></dt> - <dd>access control mechanisms controlled by the user, for example Unix - rwx file permissions. These contrast with <a - href="#mandatory">mandatory access controls</a>.</dd> - <dt><a name="DNS">DNS</a></dt> - <dd><b>D</b>omain <b>N</b>ame <b>S</b>ervice, a distributed database - through which names are associated with numeric addresses and other - information in the Internet Protocol Suite. See also the <a - href="background.html#dns.background">DNS background</a> section of our - documentation.</dd> - <dt>DOS attack</dt> - <dd>see <a href="#DOS">Denial Of Service</a> attack</dd> - <dt><a name="dynamic">dynamic IP address</a></dt> - <dd>an IP address which is automatically assigned, either by <a - href="#DHCP">DHCP</a> or by some protocol such as <a - href="#PPP">PPP</a> or <a href="#PPPoE">PPPoE</a> which the machine - uses to connect to the Internet. This is the opposite of a <a - href="#static">static IP address</a>, pre-set on the machine - itself.</dd> - <dt><a name="E">E</a></dt> - <dt><a name="EAR">EAR</a></dt> - <dd>The US government's <b>E</b>xport <b>A</b>dministration - <b>R</b>egulations, administered by the <a href="#BXA">Bureau of Export - Administration</a>. These have replaced the earlier <a - href="#ITAR">ITAR</a> regulations as the controls on export of - cryptography.</dd> - <dt><a name="ECB">ECB mode</a></dt> - <dd><b>E</b>lectronic <b>C</b>ode<b>B</b>ook mode, the simplest way to - use a block cipher. See <a href="#mode">Cipher Modes</a>.</dd> - <dt><a name="EDE">EDE</a></dt> - <dd>The sequence of operations normally used in either the three-key - variant of <a href="#3DES">triple DES</a> used in <a - href="#IPSEC">IPsec</a> or the <a href="#2key">two-key</a> variant used - in some other systems. - <p>The sequence is:</p> - <ul> - <li><b>E</b>ncrypt with key1</li> - <li><b>D</b>ecrypt with key2</li> - <li><b>E</b>ncrypt with key3</li> - </ul> - <p>For the two-key version, key1=key3.</p> - <p>The "advantage" of this EDE order of operations is that it makes it - simple to interoperate with older devices offering only single DES. Set - key1=key2=key3 and you have the worst of both worlds, the overhead of - triple DES with the "security" of single DES. Since both the <a - href="politics.html#desnotsecure">security of single DES</a> and the - overheads of triple DES are seriously inferior to many other ciphers, - this is a spectacularly dubious "advantage".</p> - </dd> - <dt><a name="Entrust">Entrust</a></dt> - <dd>A Canadian company offerring enterprise <a href="#PKI">PKI</a> - products using <a href="#CAST128">CAST-128</a> symmetric crypto, <a - href="#RSA">RSA</a> public key and <a href="#X509">X.509</a> - directories. <a href="http://www.entrust.com">Web site</a></dd> - <dt><a name="EFF">EFF</a></dt> - <dd><a href="http://www.eff.org">Electronic Frontier Foundation</a>, an - advocacy group for civil rights in cyberspace.</dd> - <dt><a name="encryption">Encryption</a></dt> - <dd>Techniques for converting a readable message (<a - href="#plaintext">plaintext</a>) into apparently random material (<a - href="#ciphertext">ciphertext</a>) which cannot be read if intercepted. - A key is required to read the message. - <p>Major variants include <a href="#symmetric">symmetric</a> encryption - in which sender and receiver use the same secret key and <a - href="#public">public key</a> methods in which the sender uses one of a - matched pair of keys and the receiver uses the other. Many current - systems, including <a href="#IPSEC">IPsec</a>, are <a - href="#hybrid">hybrids</a> combining the two techniques.</p> - </dd> - <dt><a name="ESP">ESP</a></dt> - <dd><b>E</b>ncapsulated <b>S</b>ecurity <b>P</b>ayload, the <a - href="#IPSEC">IPsec</a> protocol which provides <a - href="#encryption">encryption</a>. It can also provide <a - href="#authentication">authentication</a> service and may be used with - null encryption (which we do not recommend). For details see our <a - href="ipsec.html#ESP.ipsec">IPsec</a> document and/or RFC 2406.</dd> - <dt><a name="#extruded">Extruded subnet</a></dt> - <dd>A situation in which something IP sees as one network is actually in - two or more places. - <p>For example, the Internet may route all traffic for a particular - company to that firm's corporate gateway. It then becomes the company's - problem to get packets to various machines on their <a - href="#subnet">subnets</a> in various departments. They may decide to - treat a branch office like a subnet, giving it IP addresses "on" their - corporate net. This becomes an extruded subnet.</p> - <p>Packets bound for it are delivered to the corporate gateway, since - as far as the outside world is concerned, that subnet is part of the - corporate network. However, instead of going onto the corporate LAN (as - they would for, say, the accounting department) they are then - encapsulated and sent back onto the Internet for delivery to the branch - office.</p> - <p>For information on doing this with Linux FreeS/WAN, look in our <a - href="adv_config.html#extruded.config">advanced configuration</a> - section.</p> - </dd> - <dt>Exhaustive search</dt> - <dd>See <a href="#brute">brute force attack</a>.</dd> - <dt><a name="F">F</a></dt> - <dt><a name="FIPS">FIPS</a></dt> - <dd><b>F</b>ederal <b>I</b>nformation <b>P</b>rocessing <b>S</b>tandard, - the US government's standards for products it buys. These are issued by - <a href="#NIST">NIST</a>. Among other things, <a href="#DES">DES</a> - and <a href="#SHA">SHA</a> are defined in FIPS documents. NIST have a - <a href="http://www.itl.nist.gov/div897/pubs">FIPS home page</a>.</dd> - <dt><a name="FSF">Free Software Foundation (FSF)</a></dt> - <dd>An organisation to promote free software, free in the sense of these - quotes from their web pages</dd> - <dd> - <blockquote> - "Free software" is a matter of liberty, not price. To understand the - concept, you should think of "free speech", not "free beer." - <p>"Free software" refers to the users' freedom to run, copy, - distribute, study, change and improve the software.</p> - </blockquote> - <p>See also <a href="#GNU">GNU</a>, <a href="#GPL">GNU General Public - License</a>, and <a href="http://www.fsf.org">the FSF site</a>.</p> - </dd> - <dt>FreeS/WAN</dt> - <dd>see <a href="#FreeSWAN">Linux FreeS/WAN</a></dd> - <dt><a name="fullnet">Fullnet</A></dt> - <dd>The CIDR block containing all IPs of its IP version. - The <A HREF="#IPv4">IPv4</A> fullnet is written 0.0.0.0/0. - Also known as "all" and "default", - fullnet may be used in a routing table - to specify a default route, - and in a FreeS/WAN - <A HREF="policygroups.html#policygroups">policy group</A> file to - specify a default IPsec policy.</dd> - <dt>FSF</dt> - <dd>see <a href="#FSF">Free software Foundation</a></dd> - <dt><a name="G">G</a></dt> - <dt><a name="GCHQ">GCHQ</a></dt> - <dd><a href="http://www.gchq.gov.uk">Government Communications - Headquarters</a>, the British organisation for <a - href="#SIGINT">signals intelligence</a>.</dd> - <dt>generator of a prime field</dt> - <dd>see <a href="#dlog">discrete logarithm problem</a></dd> - <dt><a name="GILC">GILC</a></dt> - <dd><a href="http://www.gilc.org">Global Internet Liberty Campaign</a>, - an international organisation advocating, among other things, free - availability of cryptography. They have a <a - href="http://www.gilc.org/crypto/wassenaar">campaign</a> to remove - cryptographic software from the <a href="#Wassenaar.gloss">Wassenaar - Arrangement</a>.</dd> - <dt>Global Internet Liberty Campaign</dt> - <dd>see <a href="#GILC">GILC</a>.</dd> - <dt><a name="GTR">Global Trust Register</a></dt> - <dd>An attempt to create something like a <a href="#rootCA">root CA</a> - for <a href="#PGP">PGP</a> by publishing both <a - href="biblio.html#GTR">as a book</a> and <a - href="http://www.cl.cam.ac.uk/Research/Security/Trust-Register"> on the - web</a> the fingerprints of a set of verified keys for well-known users - and organisations.</dd> - <dt><a name="GMP">GMP</a></dt> - <dd>The <b>G</b>NU <b>M</b>ulti-<b>P</b>recision library code, used in <a - href="#FreeSWAN">Linux FreeS/WAN</a> by <a href="#Pluto">Pluto</a> for - <a href="#public">public key</a> calculations. See the <a - href="http://www.swox.com/gmp">GMP home page</a>.</dd> - <dt><a name="GNU">GNU</a></dt> - <dd><b>G</b>NU's <b>N</b>ot <b>U</b>nix, the <a href="#FSF">Free Software - Foundation's</a> project aimed at creating a free system with at least - the capabilities of Unix. <a href="#Linux">Linux</a> uses GNU utilities - extensively.</dd> - <dt><a name="#GOST">GOST</a></dt> - <dd>a Soviet government standard <a href="#block">block cipher</a>. <a - href="biblio.html#schneier">Applied Cryptography</a> has details.</dd> - <dt>GPG</dt> - <dd>see <a href="#GPG">GNU Privacy Guard</a></dd> - <dt><a name="GPL">GNU General Public License</a>(GPL, copyleft)</dt> - <dd>The license developed by the <a href="#FSF">Free Software - Foundation</a> under which <a href="#Linux">Linux</a>, <a - href="#FreeSWAN">Linux FreeS/WAN</a> and many other pieces of software - are distributed. The license allows anyone to redistribute and modify - the code, but forbids anyone from distributing executables without - providing access to source code. For more details see the file <a - href="../COPYING">COPYING</a> included with GPLed source distributions, - including ours, or <a href="http://www.fsf.org/copyleft/gpl.html"> the - GNU site's GPL page</a>.</dd> - <dt><a name="GPG">GNU Privacy Guard</a></dt> - <dd>An open source implementation of Open <a href="#PGP">PGP</a> as - defined in RFC 2440. See their <a href="http://www.gnupg.org">web - site</a></dd> - <dt>GPL</dt> - <dd>see <a href="#GPL">GNU General Public License</a>.</dd> - <dt><a name="H">H</a></dt> - <dt><a name="hash">Hash</a></dt> - <dd>see <a href="#digest">message digest</a></dd> - <dt><a name="HMAC">Hashed Message Authentication Code (HMAC)</a></dt> - <dd>using keyed <a href="#digest">message digest</a> functions to - authenticate a message. This differs from other uses of these functions: - <ul> - <li>In normal usage, the hash function's internal variable are - initialised in some standard way. Anyone can reproduce the hash to - check that the message has not been altered.</li> - <li>For HMAC usage, you initialise the internal variables from the - key. Only someone with the key can reproduce the hash. A successful - check of the hash indicates not only that the message is unchanged - but also that the creator knew the key.</li> - </ul> - <p>The exact techniques used in <a href="#IPSEC">IPsec</a> are defined - in RFC 2104. They are referred to as HMAC-MD5-96 and HMAC-SHA-96 - because they output only 96 bits of the hash. This makes some attacks - on the hash functions harder.</p> - </dd> - <dt>HMAC</dt> - <dd>see <a href="#HMAC">Hashed Message Authentication Code</a></dd> - <dt>HMAC-MD5-96</dt> - <dd>see <a href="#HMAC">Hashed Message Authentication Code</a></dd> - <dt>HMAC-SHA-96</dt> - <dd>see <a href="#HMAC">Hashed Message Authentication Code</a></dd> - <dt><a name="hybrid">Hybrid cryptosystem</a></dt> - <dd>A system using both <a href="#public">public key</a> and <a - href="#symmetric">symmetric cipher</a> techniques. This works well. - Public key methods provide key management and <a - href="#signature">digital signature</a> facilities which are not - readily available using symmetric ciphers. The symmetric cipher, - however, can do the bulk of the encryption work much more efficiently - than public key methods.</dd> - <dt><a name="I">I</a></dt> - <dt><a name="IAB">IAB</a></dt> - <dd><a href="http://www.iab.org/iab">Internet Architecture Board</a>.</dd> - <dt><a name="ICMP.gloss">ICMP</a></dt> - <dd><strong>I</strong>nternet <strong>C</strong>ontrol - <strong>M</strong>essage <strong>P</strong>rotocol. This is used for - various IP-connected devices to manage the network.</dd> - <dt><a name="IDEA">IDEA</a></dt> - <dd><b>I</b>nternational <b>D</b>ata <b>E</b>ncrypion <b>A</b>lgorithm, - developed in Europe as an alternative to exportable American ciphers - such as <a href="#DES">DES</a> which were <a href="#desnotsecure">too - weak for serious use</a>. IDEA is a <a href="#block">block cipher</a> - using 64-bit blocks and 128-bit keys, and is used in products such as - <a href="#PGP">PGP</a>. - <p>IDEA is not required by the <a href="#IPSEC">IPsec</a> RFCs and not - currently used in <a href="#FreeSWAN">Linux FreeS/WAN</a>.</p> - <p>IDEA is patented and, with strictly limited exceptions for personal - use, using it requires a license from <a - href="http://www.ascom.com">Ascom</a>.</p> - </dd> - <dt><a name="IEEE">IEEE</a></dt> - <dd><a href="http://www.ieee.org">Institute of Electrical and Electronic - Engineers</a>, a professional association which, among other things, - sets some technical standards</dd> - <dt><a name="IESG">IESG</a></dt> - <dd><a href="http://www.iesg.org">Internet Engineering Steering - Group</a>.</dd> - <dt><a name="IETF">IETF</a></dt> - <dd><a href="http://www.ietf.org">Internet Engineering Task Force</a>, - the umbrella organisation whose various working groups make most of the - technical decisions for the Internet. The IETF <a - href="http://www.ietf.org/html.charters/ipsec-charter.html"> IPsec - working group</a> wrote the <a href="#RFC">RFCs</a> we are - implementing.</dd> - <dt><a name="IKE">IKE</a></dt> - <dd><b>I</b>nternet <b>K</b>ey <b>E</b>xchange, based on the <a - href="#DH">Diffie-Hellman</a> key exchange protocol. For details, see - RFC 2409 and our <a href="ipsec.html">IPsec</a> document. IKE is - implemented in <a href="#FreeSWAN">Linux FreeS/WAN</a> by the <a - href="#Pluto">Pluto daemon</a>.</dd> - <dt>IKE v2</dt> - <dd>A proposed replacement for <a href="#IKE">IKE</a>. There are other - candidates, such as <a href="#JFK">JFK</a>, and at time of writing - (March 2002) the choice between them has not yet been made and does not - appear imminent.</dd> - <dt><a name="iOE">iOE</a></dt> - <dd>See <A HREF="#initiate-only">Initiate-only opportunistic - encryption</A>.</dd> - <dt><a name="IP">IP</a></dt> - <dd><b>I</b>nternet <b>P</b>rotocol.</dd> - <dt><a name="masq">IP masquerade</a></dt> - <dd>A mostly obsolete term for a method of allowing multiple machines to - communicate over the Internet when only one IP address is available for - their use. The more current term is Network Address Translation or <a - href="#NAT.gloss">NAT</a>.</dd> - <dt><a name="IPng">IPng</a></dt> - <dd>"IP the Next Generation", see <a href="#ipv6.gloss">IPv6</a>.</dd> - <dt><a name="IPv4">IPv4</a></dt> - <dd>The current version of the <a href="#IP">Internet protocol - suite</a>.</dd> - <dt><a name="ipv6.gloss">IPv6 (IPng)</a></dt> - <dd>Version six of the <a href="#IP">Internet protocol suite</a>, - currently being developed. It will replace the current <a - href="#IPv4">version four</a>. IPv6 has <a href="#IPSEC">IPsec</a> as a - mandatory component. - <p>See this <a - href="http://playground.sun.com/pub/ipng/html/ipng-main.html">web - site</a> for more details, and our <a - href="compat.html#ipv6">compatibility</a> document for information on - FreeS/WAN and the Linux implementation of IPv6.</p> - </dd> - <dt><a name="IPSEC">IPsec</a> or IPSEC</dt> - <dd><b>I</b>nternet <b>P</b>rotocol <b>SEC</b>urity, security functions - (<a href="#authentication">authentication</a> and <a - href="#encryption">encryption</a>) implemented at the IP level of the - protocol stack. It is optional for <a href="#IPv4">IPv4</a> and - mandatory for <a href="#ipv6.gloss">IPv6</a>. - <p>This is the standard <a href="#FreeSWAN">Linux FreeS/WAN</a> is - implementing. For more details, see our <a href="ipsec.html">IPsec - Overview</a>. For the standards, see RFCs listed in our <a - href="rfc.html#RFC">RFCs document</a>.</p> - </dd> - <dt><a name="IPX">IPX</a></dt> - <dd>Novell's Netware protocol tunnelled over an IP link. Our <a - href="firewall.html#user.scripts">firewalls</a> document includes an - example of using this through an IPsec tunnel.</dd> - <dt><a name="ISAKMP">ISAKMP</a></dt> - <dd><b>I</b>nternet <b>S</b>ecurity <b>A</b>ssociation and <b>K</b>ey - <b>M</b>anagement <b>P</b>rotocol, defined in RFC 2408.</dd> - <dt><a name="ITAR">ITAR</a></dt> - <dd><b>I</b>nternational <b>T</b>raffic in <b>A</b>rms - <b>R</b>egulations, US regulations administered by the State Department - which until recently limited export of, among other things, - cryptographic technology and software. ITAR still exists, but the - limits on cryptography have now been transferred to the <a - href="#EAR">Export Administration Regulations</a> under the Commerce - Department's <a href="#BXA">Bureau of Export Administration</a>.</dd> - <dt>IV</dt> - <dd>see <a href="#IV">Initialisation vector</a></dd> - <dt><a name="IV">Initialisation Vector (IV)</a></dt> - <dd>Some cipher <a href="#mode">modes</a>, including the <a - href="#CBC">CBC</a> mode which IPsec uses, require some extra data at - the beginning. This data is called the initialisation vector. It need - not be secret, but should be different for each message. Its function - is to prevent messages which begin with the same text from encrypting - to the same ciphertext. That might give an analyst an opening, so it is - best prevented.</dd> - <dt><a name="initiate-only">Initiate-only opportunistic - encryption (iOE)</a></dt> - <dd>A form of - <A HREF="#carpediem">opportunistic encryption</A> (OE) in which - a host proposes opportunistic connections, but lacks the reverse DNS - records necessary to support incoming opportunistic connection requests. - Common among hosts on cable or pppoe connections where the system - administrator does not have write access to the DNS reverse map - for the host's external IP. - <p>Configuring for initiate-only opportunistic encryption - is described in our - <a href="quickstart.html#opp.client">quickstart</a> document.</p> - </dd> - <dt><a name="J">J</a></dt> - <dt><a name="JFK">JFK</a></dt> - <dd><strong>J</strong>ust <strong>F</strong>ast <strong>K</strong>eying, - a proposed simpler replacement for <a href="#IKE">IKE.</a></dd> - <dt><a name="K">K</a></dt> - <dt><a name="kernel">Kernel</a></dt> - <dd>The basic part of an operating system (e.g. Linux) which controls the - hardware and provides services to all other programs. - <p>In the Linux release numbering system, an even second digit as in - 2.<strong>2</strong>.x indicates a stable or production kernel while an - odd number as in 2.<strong>3</strong>.x indicates an experimental or - development kernel. Most users should run a recent kernel version from - the production series. The development kernels are primarily for people - doing kernel development. Others should consider using development - kernels only if they have an urgent need for some feature not yet - available in production kernels.</p> - </dd> - <dt>Keyed message digest</dt> - <dd>See <a href="#HMAC">HMAC</a>.</dd> - <dt>Key length</dt> - <dd>see <a href="#brute">brute force attack</a></dd> - <dt><a name="KLIPS">KLIPS</a></dt> - <dd><b>K</b>erne<b>l</b> <b>IP</b> <b>S</b>ecurity, the <a - href="#FreeSWAN">Linux FreeS/WAN</a> project's changes to the <a - href="#Linux">Linux</a> kernel to support the <a - href="#IPSEC">IPsec</a> protocols.</dd> - <dt><a name="L">L</a></dt> - <dt><a name="LDAP">LDAP</a></dt> - <dd><b>L</b>ightweight <b>D</b>irectory <b>A</b>ccess <b>P</b>rotocol, - defined in RFCs 1777 and 1778, a method of accessing information - stored in directories. LDAP is used by several <a href="#PKI">PKI</a> - implementations, often with X.501 directories and <a - href="#X509">X.509</a> certificates. It may also be used by <a - href="#IPSEC">IPsec</a> to obtain key certifications from those PKIs. - This is not yet implemented in <a href="#FreeSWAN">Linux - FreeS/WAN</a>.</dd> - <dt><a name="LIBDES">LIBDES</a></dt> - <dd>A publicly available library of <a href="#DES">DES</a> code, written - by Eric Young, which <a href="#FreeSWAN">Linux FreeS/WAN</a> uses in - both <a href="#KLIPS">KLIPS</a> and <a href="#Pluto">Pluto</a>.</dd> - <dt><a name="Linux">Linux</a></dt> - <dd>A freely available Unix-like operating system based on a kernel - originally written for the Intel 386 architecture by (then) student - Linus Torvalds. Once his 32-bit kernel was available, the <a - href="#GNU">GNU</a> utilities made it a usable system and contributions - from many others led to explosive growth. - <p>Today Linux is a complete Unix replacement available for several CPU - architectures -- Intel, DEC/Compaq Alpha, Power PC, both 32-bit SPARC - and the 64-bit UltraSPARC, SrongARM, . . . -- with support for multiple - CPUs on some architectures.</p> - <p><a href="#FreeSWAN">Linux FreeS/WAN</a> is intended to run on all - CPUs supported by Linux and is known to work on several. See our <a - href="compat.html#CPUs">compatibility</a> section for a list.</p> - </dd> - <dt><a name="FreeSWAN">Linux FreeS/WAN</a></dt> - <dd>Our implementation of the <a href="#IPSEC">IPsec</a> protocols, - intended to be freely redistributable source code with <a href="#GPL">a - GNU GPL license</a> and no constraints under US or other <a - href="politics.html#exlaw">export laws</a>. Linux FreeS/WAN is intended - to interoperate with other <a href="#IPSEC">IPsec</a> implementations. - The name is partly taken, with permission, from the <a - href="#SWAN">S/WAN</a> multi-vendor IPsec compatability effort. Linux - FreeS/WAN has two major components, <a href="#KLIPS">KLIPS</a> (KerneL - IPsec Support) and the <a href="#Pluto">Pluto</a> daemon which manages - the whole thing. - <p>See our <a href="ipsec.html">IPsec section</a> for more detail. For - the code see our <a href="http://freeswan.org"> primary site</a> or one - of the mirror sites on <a href="intro.html#mirrors">this list</a>.</p> - </dd> - <dt><a name="LSM">Linux Security Modules (LSM)</a></dt> - <dd>a project to create an interface in the Linux kernel that supports - plug-in modules for various security policies. - <p>This allows multiple security projects to take different approaches - to security enhancement without tying the kernel down to one particular - approach. As I understand the history, several projects were pressing - Linus to incorporate their changes, the various sets of changes were - incompatible, and his answer was more-or-less "a plague on all your - houses; I'll give you an interface, but I won't incorporate - anything".</p> - <p>It seems to be working. There is a fairly active <a - href="http://mail.wirex.com/mailman/listinfo/linux-security-module">LSM - mailing list</a>, and several projects are already using the - interface.</p> - </dd> - <dt>LSM</dt> - <dd>see <a href="#LSM">Linux Security Modules</a></dd> - <dt><a name="M">M</a></dt> - <dt><a name="list">Mailing list</a></dt> - <dd>The <a href="#FreeSWAN">Linux FreeS/WAN</a> project has several - public email lists for bug reports and software development - discussions. See our document on <a href="mail.html">mailing - lists</a>.</dd> - <dt><a name="middle">Man-in-the-middle attack</a></dt> - <dd>An <a href="#active">active attack</a> in which the attacker - impersonates each of the legitimate players in a protocol to the other. - <p>For example, if <a href="#alicebob">Alice and Bob</a> are - negotiating a key via the <a href="#DH">Diffie-Hellman</a> key - agreement, and are not using <a - href="#authentication">authentication</a> to be certain they are - talking to each other, then an attacker able to insert himself in the - communication path can deceive both players.</p> - <p>Call the attacker Mallory. For Bob, he pretends to be Alice. For - Alice, he pretends to be Bob. Two keys are then negotiated, - Alice-to-Mallory and Bob-to-Mallory. Alice and Bob each think the key - they have is Alice-to-Bob.</p> - <p>A message from Alice to Bob then goes to Mallory who decrypts it, - reads it and/or saves a copy, re-encrypts using the Bob-to-Mallory key - and sends it along to Bob. Bob decrypts successfully and sends a reply - which Mallory decrypts, reads, re-encrypts and forwards to Alice.</p> - <p>To make this attack effective, Mallory must</p> - <ul> - <li>subvert some part of the network in some way that lets him carry - out the deception<br> - possible targets: DNS, router, Alice or Bob's machine, mail server, - ...</li> - <li>beat any authentication mechanism Alice and Bob use<br> - strong authentication defeats the attack entirely; this is why <a - href="#IKE">IKE</a> requires authentication</li> - <li>work in real time, delivering messages without introducing a - delay large enough to alert the victims<br> - not hard if Alice and Bob are using email; quite difficult in some - situations.</li> - </ul> - <p>If he manages it, however, it is devastating. He not only gets to - read all the messages; he can alter messages, inject his own, forge - anything he likes, . . . In fact, he controls the communication - completely.</p> - </dd> - <dt><a name="mandatory">mandatory access control</a></dt> - <dd>access control mechanisims which are not settable by the user (see <a - href="#discretionary">discretionary access control</a>), but are - enforced by the system. - <p>For example, a document labelled "secret, zebra" might be readable - only by someone with secret clearance working on Project Zebra. - Ideally, the system will prevent any transfer outside those boundaries. - For example, even if you can read it, you should not be able to e-mail - it (unless the recipient is appropriately cleared) or print it (unless - certain printers are authorised for that classification).</p> - <p>Mandatory access control is a required feature for some levels of <a - href="#rainbow">Rainbow Book</a> or <a href="#cc">Common Criteria</a> - classification, but has not been widely used outside the military and - government. There is a good discussion of the issues in Anderson's <a - href="biblio.html#anderson">Security Engineering</a>.</p> - <p>The <a href="#SElinux">Security Enhanced Linux</a> project is adding - mandatory access control to Linux.</p> - </dd> - <dt><a name="manual">Manual keying</a></dt> - <dd>An IPsec mode in which the keys are provided by the administrator. In - FreeS/WAN, they are stored in /etc/ipsec.conf. The alternative, <a - href="#auto">automatic keying</a>, is preferred in most cases. See this - <a href="adv_config.html#man-auto">discussion</a>.</dd> - <dt><a name="MD4">MD4</a></dt> - <dd><a href="#digest">Message Digest Algorithm</a> Four from Ron Rivest - of <a href="#RSAco">RSA</a>. MD4 was widely used a few years ago, but - is now considered obsolete. It has been replaced by its descendants <a - href="#MD5">MD5</a> and <a href="#SHA">SHA</a>.</dd> - <dt><a name="MD5">MD5</a></dt> - <dd><a href="#digest">Message Digest Algorithm</a> Five from Ron Rivest - of <a href="#RSAco">RSA</a>, an improved variant of his <a - href="#MD4">MD4</a>. Like MD4, it produces a 128-bit hash. For details - see RFC 1321. - <p>MD5 is one of two message digest algorithms available in IPsec. The - other is <a href="#SHA">SHA</a>. SHA produces a longer hash and is - therefore more resistant to <a href="#birthday">birthday attacks</a>, - but this is not a concern for IPsec. The <a href="#HMAC">HMAC</a> - method used in IPsec is secure even if the underlying hash is not - particularly strong against this attack.</p> - <p>Hans Dobbertin found a weakness in MD5, and people often ask whether - this means MD5 is unsafe for IPsec. It doesn't. The IPsec RFCs discuss - Dobbertin's attack and conclude that it does not affect MD5 as used for - HMAC in IPsec.</p> - </dd> - <dt><a name="meet">Meet-in-the-middle attack</a></dt> - <dd>A divide-and-conquer attack which breaks a cipher into two parts, - works against each separately, and compares results. Probably the best - known example is an attack on double DES. This applies in principle to - any pair of block ciphers, e.g. to an encryption system using, say, - CAST-128 and Blowfish, but we will describe it for double DES. - <p>Double DES encryption and decryption can be written:</p> - <pre> C = E(k2,E(k1,P)) - P = D(k1,D(k2,C))</pre> - <p>Where C is ciphertext, P is plaintext, E is encryption, D is - decryption, k1 is one key, and k2 is the other key. If we know a P, C - pair, we can try and find the keys with a brute force attack, trying - all possible k1, k2 pairs. Since each key is 56 bits, there are - 2<sup>112</sup> such pairs and this attack is painfully inefficient.</p> - <p>The meet-in-the middle attack re-writes the equations to calculate a - middle value M:</p> - <pre> M = E(k1,P) - M = D(k2,C)</pre> - <p>Now we can try some large number of D(k2,C) decryptions with various - values of k2 and store the results in a table. Then start doing E(k1,P) - encryptions, checking each result to see if it is in the table.</p> - <p>With enough table space, this breaks double DES with - <nobr>2<sup>56</sup> + 2<sup>56</sup> = 2<sup>57</sup></nobr>work. - Against triple DES, you need <nobr>2<sup>56</sup> + 2<sup>112</sup> ~= - 2<sup>112</sup></nobr>.</p> - <p>The memory requirements for such attacks can be prohibitive, but - there is a whole body of research literature on methods of reducing - them.</p> - </dd> - <dt><a name="digest">Message Digest Algorithm</a></dt> - <dd>An algorithm which takes a message as input and produces a hash or - digest of it, a fixed-length set of bits which depend on the message - contents in some highly complex manner. Design criteria include making - it extremely difficult for anyone to counterfeit a digest or to change - a message without altering its digest. One essential property is <a - href="#collision">collision resistance</a>. The main applications are - in message <a href="#authentication">authentication</a> and <a - href="#signature">digital signature</a> schemes. Widely used algorithms - include <a href="#MD5">MD5</a> and <a href="#SHA">SHA</a>. In IPsec, - message digests are used for <a href="#HMAC">HMAC</a> authentication of - packets.</dd> - <dt><a name="MTU">MTU</a></dt> - <dd><strong>M</strong>aximum <strong>T</strong>ransmission - <strong>U</strong>nit, the largest size of packet that can be sent over - a link. This is determined by the underlying network, but must be taken - account of at the IP level. - <p>IP packets, which can be up to 64K bytes each, must be packaged into - lower-level packets of the appropriate size for the underlying - network(s) and re-assembled on the other end. When a packet must pass - over multiple networks, each with its own MTU, and many of the MTUs are - unknown to the sender, this becomes a fairly complex problem. See <a - href="#pathMTU">path MTU discovery</a> for details.</p> - <p>Often the MTU is a few hundred bytes on serial links and 1500 on - Ethernet. There are, however, serial link protocols which use a larger - MTU to avoid fragmentation at the ethernet/serial boundary, and newer - (especially gigabit) Ethernet networks sometimes support much larger - packets because these are more efficient in some applications.</p> - </dd> - <dt><a name="N">N</a></dt> - <dt><a name="NAI">NAI</a></dt> - <dd><a href="http://www.nai.com">Network Associates</a>, a conglomerate - formed from <a href="#PGPI">PGP Inc.</a>, TIS (Trusted Information - Systems, a firewall vendor) and McAfee anti-virus products. Among other - things, they offer an IPsec-based VPN product.</dd> - <dt><a name="NAT.gloss">NAT</a></dt> - <dd><b>N</b>etwork <b>A</b>ddress <b>T</b>ranslation, a process by which - firewall machines may change the addresses on packets as they go - through. For discussion, see our <a - href="background.html#nat.background">background</a> section.</dd> - <dt><a name="NIST">NIST</a></dt> - <dd>The US <a href="http://www.nist.gov"> National Institute of Standards - and Technology</a>, responsible for <a href="#FIPS">FIPS standards</a> - including <a href="#DES">DES</a> and its replacement, <a - href="#AES">AES</a>.</dd> - <dt><a name="nonce">Nonce</a></dt> - <dd>A <a href="#random">random</a> value used in an <a - href="#authentication">authentication</a> protocol.</dd> - <dt></dt> - <dt><a name="non-routable">Non-routable IP address</a></dt> - <dd>An IP address not normally allowed in the "to" or "from" IP address - field header of IP packets. - <p>Almost invariably, the phrase "non-routable address" means one of - the addresses reserved by RFC 1918 for private networks:</p> - <ul> - <li>10.anything</li> - <li>172.x.anything with 16 <= x <= 31</li> - <li>192.168.anything</li> - </ul> - <p>These addresses are commonly used on private networks, e.g. behind a - Linux machines doing <a href="#masq">IP masquerade</a>. Machines within - the private network can address each other with these addresses. All - packets going outside that network, however, have these addresses - replaced before they reach the Internet.</p> - <p>If any packets using these addresses do leak out, they do not go - far. Most routers automatically discard all such packets.</p> - <p>Various other addresses -- the 127.0.0.0/8 block reserved for local - use, 0.0.0.0, various broadcast and network addresses -- cannot be - routed over the Internet, but are not normally included in the meaning - when the phrase "non-routable address" is used.</p> - </dd> - <dt><a name="NSA">NSA</a></dt> - <dd>The US <a href="http://www.nsa.gov"> National Security Agency</a>, - the American organisation for <a href="#SIGINT">signals - intelligence</a>, the protection of US government messages and the - interception and analysis of other messages. For details, see Bamford's - <a href="biblio.html#puzzle">"The Puzzle Palace"</a>. - <p>Some <a - href="http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB23/index.html">history - of NSA</a> documents were declassified in response to a FOIA (Freedom - of Information Act) request.</p> - </dd> - <dt><a name="O">O</a></dt> - <dt><a name="oakley">Oakley</a></dt> - <dd>A key determination protocol, defined in RFC 2412.</dd> - <dt>Oakley groups</dt> - <dd>The groups used as the basis of <a href="#DH">Diffie-Hellman</a> key - exchange in the Oakley protocol, and in <a href="#IKE">IKE</a>. Four - were defined in the original RFC, and a fifth has been <a - href="http://www.lounge.org/ike_doi_errata.html">added since</a>. - <p>Linux FreeS/WAN currently supports the three groups based on finite - fields modulo a prime (Groups 1, 2 and 5) and does not support the - elliptic curve groups (3 and 4). For a description of the difference of - the types, see <a href="#dlog">discrete logarithms</a>.</p> - </dd> - <dt><a name="OTP">One time pad</a></dt> - <dd>A cipher in which the key is: - <ul> - <li>as long as the total set of messages to be enciphered</li> - <li>absolutely <a href="#random">random</a></li> - <li>never re-used</li> - </ul> - <p>Given those three conditions, it can easily be proved that the - cipher is perfectly secure, in the sense that an attacker with - intercepted message in hand has no better chance of guessing the - message than an attacker who has not intercepted the message and only - knows the message length. No such proof exists for any other cipher.</p> - <p>There are, however, several problems with this "perfect" cipher.</p> - <p>First, it is <strong>wildly impractical</strong> for most - applications. Key management is at best difficult, often completely - impossible.</p> - <p>Second, it is <strong>extremely fragile</strong>. Small changes - which violate the conditions listed above do not just weaken the cipher - liitle. Quite often they destroy its security completely.</p> - <ul> - <li>Re-using the pad weakens the cipher to the point where it can be - broken with pencil and paper. With a computer, the attack is - trivially easy.</li> - <li>Using <em>anything</em> less than truly <a - href="#random">random</a> numbers <em>completely</em> invalidates - the security proof.</li> - <li>In particular, using computer-generated pseudo-random numbers may - give an extremely weak cipher. It might also produce a good stream - cipher, if the pseudo-random generator is both well-designed and - properely seeded.</li> - </ul> - <p>Marketing claims about the "unbreakable" security of various - products which somewhat resemble one-time pads are common. Such claims - are one of the surest signs of cryptographic <a href="#snake">snake - oil</a>; most systems marketed with such claims are worthless.</p> - <p>Finally, even if the system is implemented and used correctly, it is - <strong>highly vulnerable to a substitution attack</strong>. If an - attacker knows some plaintext and has an intercepted message, he can - discover the pad.</p> - <ul> - <li>This does not matter if the attacker is just a <a - href="#passive">passive</a> eavesdropper. It gives him no plaintext - he didn't already know and we don't care that he learns a pad which - we will never re-use.</li> - <li>However, an <a href="#active">active</a> attacker who knows the - plaintext can recover the pad, then use it to encode with whatever - he chooses. If he can get his version delivered instead of yours, - this may be a disaster. If you send "attack at dawn", the delivered - message can be anything the same length -- perhaps "retreat to - east" or "shoot generals".</li> - <li>An active attacker with only a reasonable guess at the plaintext - can try the same attack. If the guess is correct, this works and - the attacker's bogus message is delivered. If the guess is wrong, a - garbled message is delivered.</li> - </ul> - <p>In general then, despite its theoretical perfection, the - one-time-pad has very limited practical application.</p> - <p>See also the <a href="http://pubweb.nfr.net/~mjr/pubs/otpfaq/">one - time pad FAQ</a>.</p> - </dd> - <dt><a name="carpediem">Opportunistic encryption (OE)</a></dt> - <dd>A situation in which any two IPsec-aware machines can secure their - communications, without a pre-shared secret and without a common <a - href="#PKI">PKI</a> or previous exchange of public keys. This is one of - the goals of the Linux FreeS/WAN project, discussed in our <a - href="intro.html#goals">introduction</a> section. - <p>Setting up for opportunistic encryption is described in our <a - href="quickstart.html#quickstart">quickstart</a> document.</p> - </dd> - <dt><a name="responder">Opportunistic responder</a></dt> - <dd>A host which accepts, but does not initiate, requests for - <A HREF="#carpediem">opportunistic encryption</A> (OE). - An opportunistic responder has enabled OE in its - <A HREF="#passive.OE">passive</A> form (pOE) only. - A web server or file server may be usefully set up as an opportunistic - responder. - <p>Configuring passive OE is described in our - <a href="policygroups.html#policygroups">policy groups</a> document.</p> - </dd> - <dt><a name="orange">Orange book</a></dt> - <dd>the most basic and best known of the US government's <a - href="#rainbow">Rainbow Book</a> series of computer security - standards.</dd> - <dt><a name="P">P</a></dt> - <dt><a name="P1363">P1363 standard</a></dt> - <dd>An <a href="#IEEE">IEEE</a> standard for public key cryptography. <a - href="http://grouper.ieee.org/groups/1363">Web page</a>.</dd> - <dt><a name="pOE">pOE</a></dt> - <dd>See <a href="#passive.OE">Passive opportunistic encryption</a>.</dd> - <dt><a name="passive">Passive attack</a></dt> - <dd>An attack in which the attacker only eavesdrops and attempts to - analyse intercepted messages, as opposed to an <a href="#active">active - attack</a> in which he diverts messages or generates his own.</dd> - <dt><a name="passive.OE">Passive opportunistic encryption (pOE)</a></dt> - <dd>A form of - <A HREF="#carpediem">opportunistic encryption</A> (OE) in which the - host will accept opportunistic connection requests, but will not - initiate such requests. A host which runs OE in its passive form only - is known as an <A HREF="#responder">opportunistic responder</A>. - <p>Configuring passive OE is described in our - <a href="policygroups.html#policygroups">policy groups</a> document.</p> - </dd> - <dt><a name="pathMTU">Path MTU discovery</a></dt> - <dd>The process of discovering the largest packet size which all links on - a path can handle without fragmentation -- that is, without any router - having to break the packet up into smaller pieces to match the <a - href="#MTU">MTU</a> of its outgoing link. - <p>This is done as follows:</p> - <ul> - <li>originator sends the largest packets allowed by <a - href="#MTU">MTU</a> of the first link, setting the DF - (<strong>d</strong>on't <strong>f</strong>ragment) bit in the - packet header</li> - <li>any router which cannot send the packet on (outgoing MTU is too - small for it, and DF prevents fragmenting it to match) sends back - an <a href="#ICMP.gloss">ICMP</a> packet reporting the problem</li> - <li>originator looks at ICMP message and tries a smaller size</li> - <li>eventually, you settle on a size that can pass all routers</li> - <li>thereafter, originator just sends that size and no-one has to - fragment</li> - </ul> - <p>Since this requires co-operation of many systems, and since the next - packet may travel a different path, this is one of the trickier areas - of IP programming. Bugs that have shown up over the years have - included:</p> - <ul> - <li>malformed ICMP messages</li> - <li>hosts that ignore or mishandle these ICMP messages</li> - <li>firewalls blocking the ICMP messages so host does not see - them</li> - </ul> - <p>Since IPsec adds a header, it increases packet size and may require - fragmentation even where incoming and outgoing MTU are equal.</p> - </dd> - <dt><a name="PFS">Perfect forward secrecy (PFS)</a></dt> - <dd>A property of systems such as <a href="#DH">Diffie-Hellman</a> key - exchange which use a long-term key (such as the shared secret in IKE) - and generate short-term keys as required. If an attacker who acquires - the long-term key <em>provably</em> can - <ul> - <li><em>neither</em> read previous messages which he may have - archived</li> - <li><em>nor</em> read future messages without performing additional - successful attacks</li> - </ul> - <p>then the system has PFS. The attacker needs the short-term keys in - order to read the trafiic and merely having the long-term key does not - allow him to infer those. Of course, it may allow him to conduct - another attack (such as <a href="#middle">man-in-the-middle</a>) which - gives him some short-term keys, but he does not automatically get them - just by acquiring the long-term key.</p> - <p>See also -<a href="http://sandelman.ottawa.on.ca/ipsec/1996/08/msg00123.html">Phil -Karn's definition</a>. - </dd> - <dt>PFS</dt> - <dd>see Perfect Forward Secrecy</dd> - <dt><a name="PGP">PGP</a></dt> - <dd><b>P</b>retty <b>G</b>ood <b>P</b>rivacy, a personal encryption - system for email based on public key technology, written by Phil - Zimmerman. - <p>The 2.xx versions of PGP used the <a href="#RSA">RSA</a> public key - algorithm and used <a href="#IDEA">IDEA</a> as the symmetric cipher. - These versions are described in RFC 1991 and in <a - href="#PGP">Garfinkel's book</a>. Since version 5, the products from <a - href="#PGPI">PGP Inc</a>. have used <a href="#DH">Diffie-Hellman</a> - public key methods and <a href="#CAST128">CAST-128</a> symmetric - encryption. These can verify signatures from the 2.xx versions, but - cannot exchange encryted messages with them.</p> - <p>An <a href="#IETF">IETF</a> working group has issued RFC 2440 for an - "Open PGP" standard, similar to the 5.x versions. PGP Inc. staff were - among the authors. A free <a href="#GPG">Gnu Privacy Guard</a> based on - that standard is now available.</p> - <p>For more information on PGP, including how to obtain it, see our - cryptography <a href="web.html#tools">links</a>.</p> - </dd> - <dt><a name="PGPI">PGP Inc.</a></dt> - <dd>A company founded by Zimmerman, the author of <a href="#PGP">PGP</a>, - now a division of <a href="#NAI">NAI</a>. See the <a - href="http://www.pgp.com">corporate website</a>. Zimmerman left in - 2001, and early in 2002 NAI announced that they would no longer sell - PGP.. - <p>Versions 6.5 and later of the PGP product include PGPnet, an IPsec - client for Macintosh or for Windows 95/98/NT. See our <a - href="interop.html#pgpnet">interoperation documen</a>t.</p> - </dd> - <dt><a name="photuris">Photuris</a></dt> - <dd>Another key negotiation protocol, an alternative to <a - href="#IKE">IKE</a>, described in RFCs 2522 and 2523.</dd> - <dt><a name="PPP">PPP</a></dt> - <dd><b>P</b>oint-to-<b>P</b>oint <b>P</b>rotocol, originally a method of - connecting over modems or serial lines, but see also PPPoE.</dd> - <dt><a name="PPPoE">PPPoE</a></dt> - <dd><b>PPP</b> <b>o</b>ver <b>E</b>thernet, a somewhat odd protocol that - makes Ethernet look like a point-to-point serial link. It is widely - used for cable or ADSL Internet services, apparently mainly because it - lets the providers use access control and address assignmment - mechanisms developed for dialup networks. <a - href="http://www.roaringpenguin.com">Roaring Penguin</a> provide a - widely used Linux implementation.</dd> - <dt><a name="PPTP">PPTP</a></dt> - <dd><b>P</b>oint-to-<b>P</b>oint <b>T</b>unneling <b>P</b>rotocol, used - in some Microsoft VPN implementations. Papers discussing weaknesses in - it are on <a - href="http://www.counterpane.com/publish.html">counterpane.com</a>. It - is now largely obsolete, replaced by L2TP.</dd> - <dt><a name="PKI">PKI</a></dt> - <dd><b>P</b>ublic <b>K</b>ey <b>I</b>nfrastructure, the things an - organisation or community needs to set up in order to make <a - href="#public">public key</a> cryptographic technology a standard part - of their operating procedures. - <p>There are several PKI products on the market. Typically they use a - hierarchy of <a href="#CA">Certification Authorities (CAs)</a>. Often - they use <a href="#LDAP">LDAP</a> access to <a href="#X509">X.509</a> - directories to implement this.</p> - <p>See <a href="#web">Web of Trust</a> for a different sort of - infrastructure.</p> - </dd> - <dt><a name="PKIX">PKIX</a></dt> - <dd><b>PKI</b> e<b>X</b>change, an <a href="#IETF">IETF</a> standard that - allows <a href="#PKI">PKI</a>s to talk to each other. - <p>This is required, for example, when users of a corporate PKI need to - communicate with people at client, supplier or government - organisations, any of which may have a different PKI in place. I should - be able to talk to you securely whenever:</p> - <ul> - <li>your organisation and mine each have a PKI in place</li> - <li>you and I are each set up to use those PKIs</li> - <li>the two PKIs speak PKIX</li> - <li>the configuration allows the conversation</li> - </ul> - <p>At time of writing (March 1999), this is not yet widely implemented - but is under quite active development by several groups.</p> - </dd> - <dt><a name="plaintext">Plaintext</a></dt> - <dd>The unencrypted input to a cipher, as opposed to the encrypted <a - href="#ciphertext">ciphertext</a> output.</dd> - <dt><a name="Pluto">Pluto</a></dt> - <dd>The <a href="#FreeSWAN">Linux FreeS/WAN</a> daemon which handles key - exchange via the <a href="#IKE">IKE</a> protocol, connection - negotiation, and other higher-level tasks. Pluto calls the <a - href="#KLIPS">KLIPS</a> kernel code as required. For details, see the - manual page ipsec_pluto(8).</dd> - <dt><a name="public">Public Key Cryptography</a></dt> - <dd>In public key cryptography, keys are created in matched pairs. - Encrypt with one half of a pair and only the matching other half can - decrypt it. This contrasts with <a href="#symmetric">symmetric or - secret key cryptography</a> in which a single key known to both parties - is used for both encryption and decryption. - <p>One half of each pair, called the public key, is made public. The - other half, called the private key, is kept secret. Messages can then - be sent by anyone who knows the public key to the holder of the private - key. Encrypt with the public key and you know that only someone with - the matching private key can decrypt.</p> - <p>Public key techniques can be used to create <a - href="#signature">digital signatures</a> and to deal with key - management issues, perhaps the hardest part of effective deployment of - <a href="#symmetric"> symmetric ciphers</a>. The resulting <a - href="#hybrid">hybrid cryptosystems</a> use public key methods to - manage keys for symmetric ciphers.</p> - <p>Many organisations are currently creating <a href="#PKI">PKIs, - public key infrastructures</a> to make these benefits widely - available.</p> - </dd> - <dt>Public Key Infrastructure</dt> - <dd>see <a href="#PKI">PKI</a></dd> - <dt><a name="Q">Q</a></dt> - <dt><a name="R">R</a></dt> - <dt><a name="rainbow">Rainbow books</a></dt> - <dd>A set of US government standards for evaluation of "trusted computer - systems", of which the best known was the <a href="#orange">Orange - Book</a>. One fairly often hears references to "C2 security" or a - product "evaluated at B1". The Rainbow books define the standards - referred to in those comments. - <p>See this <a href="http://www.fas.org/irp/nsa/rainbow.htm">reference - page</a>.</p> - <p>The Rainbow books are now mainly obsolete, replaced by the - international <a href="#cc">Common Criteria</a> standards.</p> - </dd> - <dt><a name="random">Random</a></dt> - <dd>A remarkably tricky term, far too much so for me to attempt a - definition here. Quite a few cryptosystems have been broken via attacks - on weak random number generators, even when the rest of the system was - sound. - <p>See <a - href="http://nis.nsf.net/internet/documents/rfc/rfc1750.txt">RFC - 1750</a> for the theory.</p> - <p>See the manual pages for <a - href="manpage.d/ipsec_ranbits.8.html">ipsec_ranbits(8)</a> and - ipsec_prng(3) for more on FreeS/WAN's use of randomness. Both depend on - the random(4) device driver..</p> - <p>A couple of years ago, there was extensive mailing list discussion - (archived <a - href="http://www.openpgp.net/random/index.html">here</a>)of Linux - /dev/random and FreeS/WAN. Since then, the design of the random(4) - driver has changed considerably. Linux 2.4 kernels have the new - driver..</p> - </dd> - <dt>Raptor</dt> - <dd>A firewall product for Windows NT offerring IPsec-based VPN services. - Linux FreeS/WAN interoperates with Raptor; see our <a - href="interop.html#Raptor">interop</a> document for details. Raptor - have recently merged with Axent.</dd> - <dt><a name="RC4">RC4</a></dt> - <dd><b>R</b>ivest <b>C</b>ipher four, designed by Ron Rivest of <a - href="#RSAco">RSA</a> and widely used. Believed highly secure with - adequate key length, but often implemented with inadequate key length - to comply with export restrictions.</dd> - <dt><a name="RC6">RC6</a></dt> - <dd><b>R</b>ivest <b>C</b>ipher six, <a href="#RSAco">RSA</a>'s <a - href="#AES">AES</a> candidate cipher.</dd> - <dt><a name="replay">Replay attack</a></dt> - <dd>An attack in which the attacker records data and later replays it in - an attempt to deceive the recipient.</dd> - <dt><a name="reverse">Reverse map</a></dt> - <dd>In <a href="#DNS">DNS</a>, a table where IP addresses can be used as - the key for lookups which return a system name and/or other - information.</dd> - <dt>RFC</dt> - <dd><b>R</b>equest <b>F</b>or <b>C</b>omments, an Internet document. Some - RFCs are just informative. Others are standards. - <p>Our list of <a href="#IPSEC">IPsec</a> and other security-related - RFCs is <a href="rfc.html#RFC">here</a>, along with information on - methods of obtaining them.</p> - </dd> - <dt><a name="rijndael">Rijndael</a></dt> - <dd>a <a href="#block">block cipher</a> designed by two Belgian - cryptographers, winner of the US government's <a href="#AES">AES</a> - contest to pick a replacement for <a href="#DES">DES</a>. See the <a - href="http://www.esat.kuleuven.ac.be/~rijmen/rijndael">Rijndael home - page</a>.</dd> - <dt><a name="RIPEMD">RIPEMD</a></dt> - <dd>A <a href="#digest">message digest</a> algorithm. The current version - is RIPEMD-160 which gives a 160-bit hash.</dd> - <dt><a name="rootCA">Root CA</a></dt> - <dd>The top level <a href="#CA">Certification Authority</a> in a hierachy - of such authorities.</dd> - <dt><a name="routable">Routable IP address</a></dt> - <dd>Most IP addresses can be used as "to" and "from" addresses in packet - headers. These are the routable addresses; we expect routing to be - possible for them. If we send a packet to one of them, we expect (in - most cases; there are various complications) that it will be delivered - if the address is in use and will cause an <a - href="#ICMP.gloss">ICMP</a> error packet to come back to us if not. - <p>There are also several classes of <a - href="#non-routable">non-routable</a> IP addresses.</p> - </dd> - <dt><a name="RSA">RSA algorithm</a></dt> - <dd><b>R</b>ivest <b>S</b>hamir <b>A</b>dleman <a href="#public">public - key</a> algorithm, named for its three inventors. It is widely used and - likely to become moreso since it became free of patent encumbrances in - September 2000. - <p>RSA can be used to provide either <a - href="#encryption">encryption</a> or <a href="#signature">digital - signatures</a>. In IPsec, it is used only for signatures. These provide - gateway-to-gateway <a href="#authentication">authentication</a> for <a - href="#IKE">IKE </a>negotiations.</p> - <p>For a full explanation of the algorithm, consult one of the standard - references such as <a href="biblio.html#schneier">Applied - Cryptography</a>. A simple explanation is:</p> - <p>The great 17th century French mathematician <a - href="http://www-groups.dcs.st-andrews.ac.uk/~history/Mathematicians/Fermat.html">Fermat</a> - proved that,</p> - <p>for any prime p and number x, 0 <= x < p:</p> - <pre> x^p == x modulo p - x^(p-1) == 1 modulo p, non-zero x - </pre> - <p>From this it follows that if we have a pair of primes p, q and two - numbers e, d such that:</p> - <pre> ed == 1 modulo lcm( p-1, q-1) - </pre> - where lcm() is least common multiple, then<br> - for all x, 0 <= x < pq: - <pre> x^ed == x modulo pq - </pre> - <p>So we construct such as set of numbers p, q, e, d and publish the - product N=pq and e as the public key. Using c for <a - href="#ciphertext">ciphertext</a> and i for the input <a - href="#plaintext">plaintext</a>, encryption is then:</p> - <pre> c = i^e modulo N - </pre> - <p>An attacker cannot deduce i from the cyphertext c, short of either - factoring N or solving the <a href="#dlog">discrete logarithm</a> - problem for this field. If p, q are large primes (hundreds or thousands - of bits) no efficient solution to either problem is known.</p> - <p>The receiver, knowing the private key (N and d), can readily recover - the plaintext p since:</p> - <pre> c^d == (i^e)^d modulo N - == i^ed modulo N - == i modulo N - </pre> - <p>This gives an effective public key technique, with only a couple of - problems. It uses a good deal of computer time, since calculations with - large integers are not cheap, and there is no proof it is necessarily - secure since no-one has proven either factoring or discrete log cannot - be done efficiently. Quite a few good mathematicians have tried both - problems, and no-one has announced success, but there is no proof they - are insoluble.</p> - </dd> - <dt><a name="RSAco">RSA Data Security</a></dt> - <dd>A company founded by the inventors of the <a href="#RSA">RSA</a> - public key algorithm.</dd> - <dt><a name="S">S</a></dt> - <dt><a name="SA">SA</a></dt> - <dd><b>S</b>ecurity <b>A</b>ssociation, the channel negotiated by the - higher levels of an <a href="#IPSEC">IPsec</a> implementation (<a - href="#IKE">IKE</a>) and used by the lower (<a href="#ESP">ESP</a> and - <a href="#AH">AH</a>). SAs are unidirectional; you need a pair of them - for two-way communication. - <p>An SA is defined by three things -- the destination, the protocol - (<a href="#AH">AH</a> or<a href="#ESP">ESP</a>) and the <a - href="SPI">SPI</a>, security parameters index. It is used as an index - to look up other things such as session keys and intialisation - vectors.</p> - <p>For more detail, see our section on <a href="ipsec.html">IPsec</a> - and/or RFC 2401.</p> - </dd> - <dt><a name="SElinux">SE Linux</a></dt> - <dd><strong>S</strong>ecurity <strong>E</strong>nhanced Linux, an <a - href="#NSA">NSA</a>-funded project to add <a - href="#mandatory">mandatory access control</a> to Linux. See the <a - href="http://www.nsa.gov/selinux">project home page</a>. - <p>According to their web pages, this work will include extending - mandatory access controls to IPsec tunnels.</p> - <p>Recent versions of SE Linux code use the <a href="#LSM">Linux - Security Module</a> interface.</p> - </dd> - <dt><a name="SDNS">Secure DNS</a></dt> - <dd>A version of the <a href="#DNS">DNS or Domain Name Service</a> - enhanced with authentication services. This is being designed by the <a - href="#IETF">IETF</a> DNS security <a - href="http://www.ietf.org/ids.by.wg/dnssec.html">working group</a>. - Check the <a href="http://www.isc.org/bind.html">Internet Software - Consortium</a> for information on implementation progress and for the - latest version of <a href="#BIND">BIND</a>. Another site has <a - href="http://www.toad.com/~dnssec">more information</a>. - <p><a href="#IPSEC">IPsec</a> can use this plus <a - href="#DH">Diffie-Hellman key exchange</a> to bootstrap itself. This - allows <a href="#carpediem">opportunistic encryption</a>. Any pair of - machines which can authenticate each other via DNS can communicate - securely, without either a pre-existing shared secret or a shared <a - href="#PKI">PKI</a>.</p> - </dd> - <dt>Secret key cryptography</dt> - <dd>See <a href="#symmetric">symmetric cryptography</a></dd> - <dt>Security Association</dt> - <dd>see <a href="#SA">SA</a></dd> - <dt>Security Enhanced Linux</dt> - <dd>see <a href="#SElinux">SE Linux</a></dd> - <dt><a name="sequence">Sequence number</a></dt> - <dd>A number added to a packet or message which indicates its position in - a sequence of packets or messages. This provides some security against - <a href="#replay">replay attacks</a>. - <p>For <a href="#auto">automatic keying</a> mode, the <a - href="#IPSEC">IPsec</a> RFCs require that the sender generate sequence - numbers for each packet, but leave it optional whether the receiver - does anything with them.</p> - </dd> - <dt><a name="SHA">SHA</a></dt> - <dt>SHA-1</dt> - <dd><b>S</b>ecure <b>H</b>ash <b>A</b>lgorithm, a <a - href="#digest">message digest algorithm</a> developed by the <a - href="#NSA">NSA</a> for use in the Digital Signature standard, <a - href="#FIPS">FIPS</a> number 186 from <a href="#NIST">NIST</a>. SHA is - an improved variant of <a href="#MD4">MD4</a> producing a 160-bit hash. - <p>SHA is one of two message digest algorithms available in IPsec. The - other is <a href="#MD5">MD5</a>. Some people do not trust SHA because - it was developed by the <a href="#NSA">NSA</a>. There is, as far as we - know, no cryptographic evidence that SHA is untrustworthy, but this - does not prevent that view from being strongly held.</p> - <p>The NSA made one small change after the release of the original SHA. - They did not give reasons. Iit may be a defense against some attack - they found and do not wish to disclose. Technically the modified - algorithm should be called SHA-1, but since it has replaced the - original algorithm in nearly all applications, it is generally just - referred to as SHA..</p> - </dd> - <dt><a name="SHA-256">SHA-256</a></dt> - <dt>SHA-384</dt> - <dt>SHA-512</dt> - <dd>Newer variants of SHA designed to match the strength of the 128, 192 - and 256-bit keys of <a href="#AES">AES</a>. The work to break an - encryption algorithm's strength by <a href="#brute">brute force</a> is - 2 - <math xmlns="http://www.w3.org/1998/Math/MathML"> - <msup> - <mi>keylength</mi> - </msup> - </math> - operations but a <a href="birthday">birthday attack </a>on a hash - needs only 2 - <math xmlns="http://www.w3.org/1998/Math/MathML"> - <msup> - <mrow> - <mi>hashlength</mi> - <mo>/</mo> - <mn>2</mn> - </mrow> - </msup> - </math> - , so as a general rule you need a hash twice the size of the key to - get similar strength. SHA-256, SHA-384 and SHA-512 are designed to - match the 128, 192 and 256-bit key sizes of AES, respectively.</dd> - <dt><a name="SIGINT">Signals intelligence (SIGINT)</a></dt> - <dd>Activities of government agencies from various nations aimed at - protecting their own communications and reading those of others. - Cryptography, cryptanalysis, wiretapping, interception and monitoring - of various sorts of signals. The players include the American <a - href="#NSA">NSA</a>, British <a href="#GCHQ">GCHQ</a> and Canadian <a - href="#CSE">CSE</a>.</dd> - <dt><a name="SKIP">SKIP</a></dt> - <dd><b>S</b>imple <b>K</b>ey management for <b>I</b>nternet - <b>P</b>rotocols, an alternative to <a href="#IKE">IKE</a> developed by - Sun and being marketed by their <a - href="http://skip.incog.com">Internet Commerce Group</a>.</dd> - <dt><a name="snake">Snake oil</a></dt> - <dd>Bogus cryptography. See the <a - href="http://www.interhack.net/people/cmcurtin/snake-oil-faq.html"> - Snake Oil FAQ</a> or <a - href="http://www.counterpane.com/crypto-gram-9902.html#snakeoil">this - paper</a> by Schneier.</dd> - <dt><a name="SPI">SPI</a></dt> - <dd><b>S</b>ecurity <b>P</b>arameter <b>I</b>ndex, an index used within - <a href="#IPSEC">IPsec</a> to keep connections distinct. A <a - href="#SA">Security Association (SA)</a> is defined by destination, - protocol and SPI. Without the SPI, two connections to the same gateway - using the same protocol could not be distinguished. - <p>For more detail, see our <a href="ipsec.html">IPsec</a> section - and/or RFC 2401.</p> - </dd> - <dt><a name="SSH">SSH</a></dt> - <dd><b>S</b>ecure <b>SH</b>ell, an encrypting replacement for the - insecure Berkeley commands whose names begin with "r" for "remote": - rsh, rlogin, etc. - <p>For more information on SSH, including how to obtain it, see our - cryptography <a href="web.html#tools">links</a>.</p> - </dd> - <dt><a name="SSHco">SSH Communications Security</a></dt> - <dd>A company founded by the authors of <a href="#SSH">SSH</a>. Offices - are in <a href="http://www.ssh.fi">Finland</a> and <a - href="http://www.ipsec.com">California</a>. They have a toolkit for - developers of IPsec applications.</dd> - <dt><a name="SSL">SSL</a></dt> - <dd><a href="http://home.netscape.com/eng/ssl3">Secure Sockets Layer</a>, - a set of encryption and authentication services for web browsers, - developed by Netscape. Widely used in Internet commerce. Also known as - <a href="#TLS">TLS</a>.</dd> - <dt>SSLeay</dt> - <dd>A free implementation of <a href="#SSL">SSL</a> by Eric Young (eay) - and others. Developed in Australia; not subject to US export - controls.</dd> - <dt><a name="static">static IP address</a></dt> - <dd>an IP adddress which is pre-set on the machine itself, as opposed to - a <a href="#dynamic">dynamic address</a> which is assigned by a <a - href="#DHCP">DHCP</a> server or obtained as part of the process of - establishing a <a href="#PPP">PPP</a> or <a href="#PPPoE">PPPoE</a> - connection</dd> - <dt><a name="stream">Stream cipher</a></dt> - <dd>A <a href="#symmetric">symmetric cipher</a> which produces a stream - of output which can be combined (often using XOR or bytewise addition) - with the plaintext to produce ciphertext. Contrasts with <a - href="#block">block cipher</a>. - <p><a href="#IPSEC">IPsec</a> does not use stream ciphers. Their main - application is link-level encryption, for example of voice, video or - data streams on a wire or a radio signal.</p> - </dd> - <dt><a name="subnet">subnet</a></dt> - <dd>A group of IP addresses which are logically one network, typically - (but not always) assigned to a group of physically connected machines. - The range of addresses in a subnet is described using a subnet mask. - See next entry.</dd> - <dt>subnet mask</dt> - <dd>A method of indicating the addresses included in a subnet. Here are - two equivalent examples: - <ul> - <li>101.101.101.0/24</li> - <li>101.101.101.0 with mask 255.255.255.0</li> - </ul> - <p>The '24' is shorthand for a mask with the top 24 bits one and the - rest zero. This is exactly the same as 255.255.255.0 which has three - all-ones bytes and one all-zeros byte.</p> - <p>These indicate that, for this range of addresses, the top 24 bits - are to be treated as naming a network (often referred to as "the - 101.101.101.0/24 subnet") while most combinations of the low 8 bits can - be used to designate machines on that network. Two addresses are - reserved; 101.101.101.0 refers to the subnet rather than a specific - machine while 101.101.101.255 is a broadcast address. 1 to 254 are - available for machines.</p> - <p>It is common to find subnets arranged in a hierarchy. For example, a - large company might have a /16 subnet and allocate /24 subnets within - that to departments. An ISP might have a large subnet and allocate /26 - subnets (64 addresses, 62 usable) to business customers and /29 subnets - (8 addresses, 6 usable) to residential clients.</p> - </dd> - <dt><a name="SWAN">S/WAN</a></dt> - <dd>Secure Wide Area Network, a project involving <a href="#RSAco">RSA - Data Security</a> and a number of other companies. The goal was to - ensure that all their <a href="#IPSEC">IPsec</a> implementations would - interoperate so that their customers can communicate with each other - securely.</dd> - <dt><a name="symmetric">Symmetric cryptography</a></dt> - <dd>Symmetric cryptography, also referred to as conventional or secret - key cryptography, relies on a <em>shared secret key</em>, identical for - sender and receiver. Sender encrypts with that key, receiver decrypts - with it. The idea is that an eavesdropper without the key be unable to - read the messages. There are two main types of symmetric cipher, <a - href="#block">block ciphers</a> and <a href="#stream">stream - ciphers</a>. - <p>Symmetric cryptography contrasts with <a href="#public">public - key</a> or asymmetric systems where the two players use different - keys.</p> - <p>The great difficulty in symmetric cryptography is, of course, key - management. Sender and receiver <em>must</em> have identical keys and - those keys <em>must</em> be kept secret from everyone else. Not too - much of a problem if only two people are involved and they can - conveniently meet privately or employ a trusted courier. Quite a - problem, though, in other circumstances.</p> - <p>It gets much worse if there are many people. An application might be - written to use only one key for communication among 100 people, for - example, but there would be serious problems. Do you actually trust all - of them that much? Do they trust each other that much? Should they? - What is at risk if that key is compromised? How are you going to - distribute that key to everyone without risking its secrecy? What do - you do when one of them leaves the company? Will you even know?</p> - <p>On the other hand, if you need unique keys for every possible - connection between a group of 100, then each user must have 99 keys. - You need either 99*100/2 = 4950 <em>secure</em> key exchanges between - users or a central authority that <em>securely</em> distributes 100 key - packets, each with a different set of 99 keys.</p> - <p>Either of these is possible, though tricky, for 100 users. Either - becomes an administrative nightmare for larger numbers. Moreover, keys - <em>must</em> be changed regularly, so the problem of key distribution - comes up again and again. If you use the same key for many messages - then an attacker has more text to work with in an attempt to crack that - key. Moreover, one successful crack will give him or her the text of - all those messages.</p> - <p>In short, the <em>hardest part of conventional cryptography is key - management</em>. Today the standard solution is to build a <a - href="#hybrid">hybrid system</a> using <a href="#public">public key</a> - techniques to manage keys.</p> - </dd> - <dt><a name="T">T</a></dt> - <dt><a name="TIS">TIS</a></dt> - <dd>Trusted Information Systems, a firewall vendor now part of <a - href="#NAI">NAI</a>. Their Gauntlet product offers IPsec VPN services. - TIS implemented the first version of <a href="#SDNS">Secure DNS</a> on - a <a href="#DARPA">DARPA</a> contract.</dd> - <dt><a name="TLS">TLS</a></dt> - <dd><b>T</b>ransport <b>L</b>ayer <b>S</b>ecurity, a newer name for <a - href="#SSL">SSL</a>.</dd> - <dt><a name="TOS">TOS field</a></dt> - <dd>The <strong>T</strong>ype <strong>O</strong>f - <strong>S</strong>ervice field in an IP header, used to control - qualkity of service routing.</dd> - <dt><a name="traffic">Traffic analysis</a></dt> - <dd>Deducing useful intelligence from patterns of message traffic, - without breaking codes or reading the messages. In one case during - World War II, the British guessed an attack was coming because all - German radio traffic stopped. The "radio silence" order, intended to - preserve security, actually gave the game away. - <p>In an industrial espionage situation, one might deduce something - interesting just by knowing that company A and company B were talking, - especially if one were able to tell which departments were involved, or - if one already knew that A was looking for acquisitions and B was - seeking funds for expansion.</p> - <p>In general, traffic analysis by itself is not very useful. However, - in the context of a larger intelligence effort where quite a bit is - already known, it can be very useful. When you are solving a complex - puzzle, every little bit helps.</p> - <p><a href="#IPSEC">IPsec</a> itself does not defend against traffic - analysis, but carefully thought out systems using IPsec can provide at - least partial protection. In particular, one might want to encrypt more - traffic than was strictly necessary, route things in odd ways, or even - encrypt dummy packets, to confuse the analyst. We discuss this <a - href="ipsec.html#traffic.resist">here</a>.</p> - </dd> - <dt><a name="transport">Transport mode</a></dt> - <dd>An IPsec application in which the IPsec gateway is the destination of - the protected packets, a machine acts as its own gateway. Contrast with - <a href="#tunnel">tunnel mode</a>.</dd> - <dt>Triple DES</dt> - <dd>see <a href="#3DES">3DES</a></dd> - <dt><a name="TTL">TTL</a></dt> - <dd><strong>T</strong>ime <strong>T</strong>o <strong>L</strong>ive, used - to control <a href="#DNS">DNS</a> caching. Servers discard cached - records whose TTL expires</dd> - <dt><a name="tunnel">Tunnel mode</a></dt> - <dd>An IPsec application in which an IPsec gateway provides protection - for packets to and from other systems. Contrast with <a - href="#transport">transport mode</a>.</dd> - <dt><a name="2key">Two-key Triple DES</a></dt> - <dd>A variant of <a href="#3DES">triple DES or 3DES</a> in which only two - keys are used. As in the three-key version, the order of operations is - <a href="#EDE">EDE</a> or encrypt-decrypt-encrypt, but in the two-key - variant the first and third keys are the same. - <p>3DES with three keys has 3*56 = 168 bits of key but has only 112-bit - strength against a <a href="#meet">meet-in-the-middle</a> attack, so it - is possible that the two key version is just as strong. Last I looked, - this was an open question in the research literature.</p> - <p>RFC 2451 defines triple DES for <a href="#IPSEC">IPsec</a> as the - three-key variant. The two-key variant should not be used and is not - implemented directly in <a href="#FreeSWAN">Linux FreeS/WAN</a>. It - cannot be used in automatically keyed mode without major fiddles in the - source code. For manually keyed connections, you could make Linux - FreeS/WAN talk to a two-key implementation by setting two keys the same - in /etc/ipsec.conf.</p> - </dd> - <dt><a name="U">U</a></dt> - <dt><a name="V">V</a></dt> - <dt><a name="virtual">Virtual Interface</a></dt> - <dd>A <a href="#Linux">Linux</a> feature which allows one physical - network interface to have two or more IP addresses. See the <cite>Linux - Network Administrator's Guide</cite> in <a - href="biblio.html#kirch">book form</a> or <a - href="http://metalab.unc.edu/LDP/LDP/nag/node1.html">on the web</a> for - details.</dd> - <dt>Virtual Private Network</dt> - <dd>see <a href="#VPN">VPN</a></dd> - <dt><a name="VPN">VPN</a></dt> - <dd><b>V</b>irtual <b>P</b>rivate <b>N</b>etwork, a network which can - safely be used as if it were private, even though some of its - communication uses insecure connections. All traffic on those - connections is encrypted. - <p><a href="#IPSEC">IPsec</a> is not the only technique available for - building VPNs, but it is the only method defined by <a - href="#RFC">RFCs</a> and supported by many vendors. VPNs are by no - means the only thing you can do with IPsec, but they may be the most - important application for many users.</p> - </dd> - <dt><a name="VPNC">VPNC</a></dt> - <dd><a href="http://www.vpnc.org">Virtual Private Network Consortium</a>, - an association of vendors of VPN products.</dd> - <dt><a name="W">W</a></dt> - <dt><a name="Wassenaar.gloss">Wassenaar Arrangement</a></dt> - <dd>An international agreement restricting export of munitions and other - tools of war. Unfortunately, cryptographic software is also restricted - under the current version of the agreement. <a - href="politics.html#Wassenaar">Discussion</a>.</dd> - <dt><a name="web">Web of Trust</a></dt> - <dd><a href="#PGP">PGP</a>'s method of certifying keys. Any user can sign - a key; you decide which signatures or combinations of signatures to - accept as certification. This contrasts with the hierarchy of <a - href="#CA">CAs (Certification Authorities)</a> used in many <a - href="#PKI">PKIs (Public Key Infrastructures)</a>. - <p>See <a href="#GTR">Global Trust Register</a> for an interesting - addition to the web of trust.</p> - </dd> - <dt><a name="WEP">WEP (Wired Equivalent Privacy)</a></dt> - <dd>The cryptographic part of the <a href="#IEEE">IEEE</a> standard for - wireless LANs. As the name suggests, this is designed to be only as - secure as a normal wired ethernet. Anyone with a network conection can - tap it. Its advocates would claim this is good design, refusing to - build in complex features beyond the actual requirements. - <p>Critics refer to WEP as "Wire<em>tap</em> Equivalent Privacy", and - consider it a horribly flawed design based on bogus "requirements". You - do not control radio waves as you might control your wires, so the - metaphor in the rationale is utterly inapplicable. A security policy - that chooses not to invest resources in protecting against certain - attacks which can only be conducted by people physically plugged into - your LAN may or may not be reasonable. The same policy is completely - unreasonable when someone can "plug in" from a laptop half a block - away..</p> - <p>There has been considerable analysis indicating that WEP is - seriously flawed. A FAQ on attacks against WEP is available. Part of it - reads:</p> - - <blockquote> - ... attacks are practical to mount using only inexpensive - off-the-shelf equipment. We recommend that anyone using an 802.11 - wireless network not rely on WEP for security, and employ other - security measures to protect their wireless network. Note that our - attacks apply to both 40-bit and the so-called 128-bit versions of - WEP equally well.</blockquote> - <p>WEP appears to be yet another instance of governments, and - unfortunately some vendors and standards bodies, deliberately promoting - hopelessly flawed "security" products, apparently mainly for the - benefit of eavesdropping agencies. See this <a - href="politics.html#weak">discussion</a>.</p> - </dd> - <dt><a name="X">X</a></dt> - <dt><a name="X509">X.509</a></dt> - <dd>A standard from the <a href="http://www.itu.int">ITU (International - Telecommunication Union)</a>, for hierarchical directories with - authentication services, used in many <a href="#PKI">PKI</a> - implementations. - <p>Use of X.509 services, via the <a href="#LDAP">LDAP protocol</a>, - for certification of keys is allowed but not required by the <a - href="#IPSEC">IPsec</a> RFCs. It is not yet implemented in <a - href="#FreeSWAN">Linux FreeS/WAN</a>.</p> - </dd> - <dt>Xedia</dt> - <dd>A vendor of router and Internet access products, now part of Lucent. - Their QVPN products interoperate with Linux FreeS/WAN; see our <a - href="interop.html#Xedia">interop document</a>.</dd> - <dt><a name="Y">Y</a></dt> - <dt><a name="Z">Z</a></dt> -</dl> -</body> -</html> diff --git a/doc/src/index.html b/doc/src/index.html deleted file mode 100644 index e2530d711..000000000 --- a/doc/src/index.html +++ /dev/null @@ -1,55 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>FreeS/WAN index</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, encryption, cryptography, FreeS/WAN, FreeSWAN"> - <!-- - - Written by Claudia Schmeing for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: index.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1>FreeS/WAN documentation</h1> - -<ul> - <li><a href="intro.html">Introduction</a></li> - <li><a href="upgrading.html">Upgrading to 2.x</a></li> -</ul> - -<ul> - <li><a href="quickstart.html">Quickstart guide to Opportunistic Encryption</a></li> - <li><a href="install.html">Installing</a></li> - <li><a href="config.html">Configuring</a></li> - <li><a href="policygroups.html">Policy Groups</a> - </li> - <li><a href="interop.html">Interoperating</a> -<FONT COLOR="#FF0000">New and improved!</FONT></li> - <li><a href="faq.html">FAQ</a></li> - <li><a href="trouble.html">Troubleshooting and problem reporting</a></li> -</ul> - -<ul> - <li><a href="toc.html">Full table of contents, with much more</a></li> - <li><a href="HowTo.html">All our docs as one big file</a></li> -</ul> - -<p>For technical support and other questions, use our <a -href="mail.html">mailing lists</a>.</p> - -<pre> This index last changed: $Date: 2004/03/15 20:35:24 $</pre> - -</body> -</html> diff --git a/doc/src/initiatorstate.txt b/doc/src/initiatorstate.txt deleted file mode 100644 index 315f6da4c..000000000 --- a/doc/src/initiatorstate.txt +++ /dev/null @@ -1,66 +0,0 @@ - - | - | PF_ACQUIRE - | - V - .---------------. - | non-existant | - | connection | - `---------------' - | | | - send , | \ -expired pass / | \ send -conn. msg / | \ deny - ^ / | \ msg - | V | do \ -.---------------. | DNS \ .---------------. -| clear-text | | lookup `->| deny |---> expired -| connection | | for | connection | connection -`---------------' | destination `---------------' - ^ ^ | ^ - | | no record | | - | | OE-permissive V | no record - | | .---------------. | OE-paranoid - | `------------| potential OE |---------' - | | connection | ^ - | `---------------' | - | | | - | | got TXT record | DNSSEC failure - | | reply | - | V | wrong - | .---------------. | failure - | | authenticate |---------' - | | & parse TXT RR| ^ - | repeated `---------------' | - | ICMP | | - | failures | initiate IKE to | - | (short-timeout) | responder | - | V | - | phase-2 .---------------. | failure - | failure | pending |---------' - | (normal | OE | ^ - | timeout) | |invalid | phase-2 failure (short-timeout) - | | |<--.SPI | ICMP failures (normal timeout) - | | | | | - | | +=======+ |---' | - | | | IKE | | ^ | - `--------------| | states|---------------' - | +=======+ | | - `---------------' | - | | invalid SPI - | | - V | rekey time - .--------------. | - | keyed |<---|-------------------------------. - | connection |----' | - `--------------' | - | | - | | - V | - .--------------. connection still active | - clear-text----->| expired |------------------------------------' - deny----->| connection | - `--------------' - - -$Id: initiatorstate.txt,v 1.1 2004/03/15 20:35:24 as Exp $ diff --git a/doc/src/install.html b/doc/src/install.html deleted file mode 100644 index 09d7c5a67..000000000 --- a/doc/src/install.html +++ /dev/null @@ -1,378 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>Installing FreeS/WAN</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, installation, quickstart"> - <!-- - - Written by Claudia Schmeing for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: install.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> -<BODY> -<H1><A name="install">Installing FreeS/WAN</A></H1> - -<P>This document will teach you how to install Linux FreeS/WAN. -If your distribution comes with Linux FreeS/WAN, we offer - tips to get you started.</P> - -<H2>Requirements</H2> - -<P>To install FreeS/WAN you must:</P> -<UL> -<LI>be running Linux with the 2.4 or 2.2 kernel series. See -this <A HREF="http://www.freeswan.ca/download.php#contact">kernel -compatibility table</A>.<BR>We also have experimental support for -2.6 kernels. Here are two basic approaches: -<UL><LI> -install FreeS/WAN, including its <A HREF="ipsec.html#parts">KLIPS</A> -kernel code. This will remove the native IPsec stack and replace it -with KLIPS.</LI> -<LI> -install the FreeS/WAN <A HREF="ipsec.html#parts">userland tools</A> -(keying daemon and supporting -scripts) for use with -<A HREF="http://lartc.org/howto/lartc.ipsec.html">2.6 kernel native IPsec</A>, -</LI> -</UL> -See also these <A HREF="2.6.known-issues">known issues with 2.6</A>. -<LI>have root access to your Linux box</LI> -<LI>choose the version of FreeS/WAN you wish to install based on -<A HREF="http://www.freeswan.org/mail.html">mailing list reports</A> <!-- or -our updates page (coming soon)--></LI> -</UL> - -<H2>Choose your install method</H2> - -<P>There are three basic ways to get FreeS/WAN onto your system:</P> -<UL> -<LI>activating and testing a FreeS/WAN that <A HREF="#distroinstall">shipped -with your Linux distribution</A></LI> -<LI><A HREF="#rpminstall">RPM install</A></LI> -<LI><A HREF="#srcinstall">Install from source</A></LI> -</UL> - -<A NAME="distroinstall"></A><H2>FreeS/WAN ships with some Linuxes</H2> - -<P>FreeS/WAN comes with <A HREF="intro.html#distwith">these distributions</A>. - -<P>If you're running one of these, include FreeS/WAN in the choices you -make during installation, or add it later using the distribution's tools. -</P> - -<H3>FreeS/WAN may be altered...</H3> -<P>Your distribution may have integrated extra features, such as Andreas -Steffen's X.509 patch, into FreeS/WAN. It may also use custom -startup script locations or directory names.</P> - -<H3>You might need to create an authentication keypair</H3> - -<P>If your FreeS/WAN came with your distribution, you may wish to - generate a fresh RSA key pair. FreeS/WAN will use these keys - for authentication. - -<P> -To do this, become root, and type: -</P> - -<PRE> ipsec newhostkey --output /etc/ipsec.secrets --hostname xy.example.com - chmod 600 /etc/ipsec.secrets</PRE> - -<P>where you replace xy.example.com with your machine's fully-qualified -domain name. Generate some randomness, for example by wiggling your mouse, -to speed the process. -</P> - -<P>The resulting ipsec.secrets looks like:</P> -<PRE>: RSA { - # RSA 2192 bits xy.example.com Sun Jun 8 13:42:19 2003 - # for signatures only, UNSAFE FOR ENCRYPTION - #pubkey=0sAQOFppfeE3cC7wqJi... - Modulus: 0x85a697de137702ef0... - # everything after this point is secret - PrivateExponent: 0x16466ea5033e807... - Prime1: 0xdfb5003c8947b7cc88759065... - Prime2: 0x98f199b9149fde11ec956c814... - Exponent1: 0x9523557db0da7a885af90aee... - Exponent2: 0x65f6667b63153eb69db8f300dbb... - Coefficient: 0x90ad00415d3ca17bebff123413fc518... - } -# do not change the indenting of that "}"</PRE> - -<P>In the actual file, the strings are much longer.</P> - - -<H3>Start and test FreeS/WAN</H3> - -<P>You can now <A HREF="install.html#starttest">start FreeS/WAN and -test whether it's been successfully installed.</A>.</P> - - -<A NAME="rpminstall"></A><H2>RPM install</H2> - -<P>These instructions are for a recent Red Hat with a stock Red Hat kernel. -We know that Mandrake and SUSE also produce FreeS/WAN RPMs. If you're -running either, install using your distribution's tools.</P> - -<H3>Download RPMs</H3> - -<P>Decide which functionality you need:</P> -<UL> -<LI>standard FreeS/WAN RPMs. Use these shortcuts:<BR> -<UL> -<LI>(for 2.6 kernels: userland only)<BR> -ncftpget ftp://ftp.xs4all.nl/pub/crypto/freeswan/binaries/RedHat-RPMs/\*userland*</LI> - -<LI>(for 2.4 kernels)<BR> -ncftpget ftp://ftp.xs4all.nl/pub/crypto/freeswan/binaries/RedHat-RPMs/`uname -r | tr -d 'a-wy-z'`/\*</LI> -<LI> -or view all the offerings at our -<A href="ftp://ftp.xs4all.nl/pub/crypto/freeswan/binaries/RedHat-RPMs">FTP site</A>. -</LI></UL> -</LI> -<LI>unofficial -<A href="http://www.freeswan.ca/download.php">Super FreeS/WAN</A> -RPMs, which include Andreas Steffen's X.509 patch and more. -Super FreeS/WAN RPMs do not currently include -<A HREF="glossary.html#NAT.gloss">Network Address Translation</A> -(NAT) traversal, but Super FreeS/WAN source does.</LI> -</UL> - -<A NAME="2.6.rpm"></A> -<P>For 2.6 kernels, get the latest FreeS/WAN userland RPM, for example:</P> -<PRE> freeswan-userland-2.04.9-0.i386.rpm</PRE> - -<P>Note: FreeS/WAN's support for 2.6 kernel IPsec is preliminary. Please see -<A HREf="2.6.known-issues">2.6.known-issues</A>, and the latest -<A HREF="http://www.freeswan.org/mail.html">mailing list reports</A>.</P> -<P>Change to your new FreeS/WAN directory, and make and install the - -<P>For 2.4 kernels, get both kernel and userland RPMs. -Check your kernel version with</P> -<PRE> uname -r</PRE> - -<P>Get a kernel module which matches that version. For example:</P> -<PRE> freeswan-module-2.04_2.4.20_20.9-0.i386.rpm</PRE> -<P>Note: These modules -<B>will only work on the Red Hat kernel they were built for</B>, -since they are very sensitive to small changes in the kernel.</P> - - -<P>Get FreeS/WAN utilities to match. For example:</P> -<PRE> freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm</PRE> - - -<H3>For freeswan.org RPMs: check signatures</H3> - -<P>While you're at our ftp site, grab the RPM signing key</P> -<PRE> freeswan-rpmsign.asc</PRE> - -<P>If you're running RedHat 8.x or later, import this key into the RPM -database:</P> -<PRE> rpm --import freeswan-rpmsign.asc</PRE> - -<P>For RedHat 7.x systems, you'll need to add it to your -<A HREF="glossary.html#PGP">PGP</A> keyring:</P> -<PRE> pgp -ka freeswan-rpmsign.asc</PRE> - - -<P>Check the digital signatures on both RPMs using:</P> -<PRE> rpm --checksig freeswan*.rpm </PRE> - -<P>You should see that these signatures are good:</P> -<PRE> freeswan-module-2.04_2.4.20_20.9-0.i386.rpm: pgp md5 OK - freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm: pgp md5 OK</PRE> - - -<H3>Install the RPMs</H3> - -<P>Become root:</P> -<PRE> su</PRE> - -<P>For a first time install, use:</P> -<PRE> rpm -ivh freeswan*.rpm</PRE> - -<P>To upgrade existing RPMs (and keep all .conf files in place), use:</P> -<PRE> rpm -Uvh freeswan*.rpm</PRE> - -<P>If you're upgrading from FreeS/WAN 1.x to 2.x RPMs, and encounter problems, -see <A HREF="upgrading.html#upgrading.rpms">this note</A>.</P> - - -<H3>Start and Test FreeS/WAN</H3> - -<P>Now, <A HREF="install.html#starttest">start FreeS/WAN and test your -install</A>.</P> - - -<A NAME="srcinstall"></A><H2>Install from Source</H2> -<!-- Most of this section, along with "Start and Test", can replace -INSTALL. --> - -<H3>Decide what functionality you need</H3> - -<P>Your choices are:</P> -<UL> -<LI><A HREF="ftp://ftp.xs4all.nl/pub/crypto/freeswan">standard -FreeS/WAN</A>,</LI> -<LI>standard FreeS/WAN plus any of these - <A HREF="web.html#patch">user-supported patches</A>, or</LI> -<LI><A HREF="http://www.freeswan.ca/download">Super FreeS/WAN</A>, -an unofficial FreeS/WAN pre-patched with many of the above. Provides -additional algorithms, X.509, SA deletion, dead peer detection, and -<A HREF="glossary.html#NAT.gloss">Network Address Translation</A> -(NAT) traversal.</LI> -</UL> - -<H3>Download FreeS/WAN</H3> - -<P>Download the source tarball you've chosen, along with any patches.</P> - -<H3>For freeswan.org source: check its signature</H3> - -<P>While you're at our ftp site, get our source signing key</P> -<PRE> freeswan-sigkey.asc</PRE> - -<P>Add it to your PGP keyring:</P> -<PRE> pgp -ka freeswan-sigkey.asc</PRE> - - -<P>Check the signature using:</P> -<PRE> pgp freeswan-2.04.tar.gz.sig freeswan-2.04.tar.gz</PRE> -<P>You should see something like:</P> -<PRE> Good signature from user "Linux FreeS/WAN Software Team (build@freeswan.org)". - Signature made 2002/06/26 21:04 GMT using 2047-bit key, key ID 46EAFCE1</PRE> -<!-- Note to self: build@freeswan.org has angled brackets in the original. - Changed because it conflicts with HTML tags. --> - -<H3>Untar, unzip</H3> - -<P>As root, unpack your FreeS/WAN source into <VAR>/usr/src</VAR>.</P> -<PRE> su - mv freeswan-2.04.tar.gz /usr/src - cd /usr/src - tar -xzf freeswan-2.04.tar.gz -</PRE> - -<H3>Patch if desired</H3> - -<P>Now's the time to add any patches. The contributor may have special -instructions, or you may simply use the patch command.</P> - -<H3>... and Make</H3> - -<P>Choose one of the methods below.</P> - -<H4>Userland-only Install for 2.6 kernels</H4> -<A NAME="2.6.src"></A> - -<P>Note: FreeS/WAN's support for 2.6 kernel IPsec is preliminary. Please see -<A HREf="2.6.known-issues">2.6.known-issues</A>, and the latest -<A HREF="http://www.freeswan.org/mail.html">mailing list reports</A>.</P> -<P>Change to your new FreeS/WAN directory, and make and install the -FreeS/WAN userland tools.</P> -<PRE> cd /usr/src/freeswan-2.04 - make programs - make install</PRE> - -<P>Now, <A HREF="install.html#starttest">start FreeS/WAN and -test your install</A>.</P> - - - -<H4>KLIPS install for 2.2, 2.4, or 2.6 kernels</H4> - -<A NAME="modinstall"></A> - -<P>To make a modular version of KLIPS, along with other FreeS/WAN programs -you'll need, use the command sequence below. This will -change to your new FreeS/WAN directory, make the FreeS/WAN module (and other -stuff), and install it all.</P> -<PRE> cd /usr/src/freeswan-2.04 - make oldmod - make minstall</PRE> - -<P><A HREF="install.html#starttest">Start FreeS/WAN and -test your install</A>.</P> - - - -<P>To link KLIPS statically into your kernel (using your old kernel settings), -and install other FreeS/WAN components, do: -</P> -<PRE> cd /usr/src/freeswan-2.04 - make oldmod - make minstall</PRE> - - -<P>Reboot your system and <A HREF="install.html#testonly">test your -install</A>.</P> - -<P>For other ways to compile KLIPS, see our Makefile.</P> - - - -<A name="starttest"></A><H2>Start FreeS/WAN and test your install</H2> - -<P>Bring FreeS/WAN up with:</P> -<PRE> service ipsec start</PRE> - -<P>This is not necessary if you've rebooted.</P> - -<A name="testonly"></A><H2>Test your install</H2> - -<P>To check that you have a successful install, run:</P> -<PRE> ipsec verify</PRE> - -<P>You should see at least:</P> -<PRE> - Checking your system to see if IPsec got installed and started correctly - Version check and ipsec on-path [OK] - Checking for KLIPS support in kernel [OK] - Checking for RSA private key (/etc/ipsec.secrets) [OK] - Checking that pluto is running [OK] -</PRE> - -<P>If any of these first four checks fails, see our -<A href="trouble.html#install.check">troubleshooting guide</A>. -</P> - - -<H2>Making FreeS/WAN play well with others</H2> - -<P>There are at least a couple of things on your system that might -interfere with FreeS/WAN, and now's a good time to check these:</P> -<UL> - <LI>Firewalling. You need to allow UDP 500 through your firewall, plus - ESP (protocol 50) and AH (protocol 51). For more information, see our - updated firewalls document (coming soon). - </LI> - <LI>Network address translation. -Do not NAT the packets you will be tunneling.</LI> -</UL> - - -<H2>Configure for your needs</H2> - -<P>You'll need to configure FreeS/WAN for your local site. Have a look at our -<A HREF="quickstart.html">opportunism quickstart guide</A> to see if that -easy method is right for your needs. Or, see how to <A HREF="config.html"> -configure a network-to-network or Road Warrior style VPN</A>. -</P> - - - - -</BODY> -</HTML> diff --git a/doc/src/interop.html b/doc/src/interop.html deleted file mode 100644 index dd4f8c577..000000000 --- a/doc/src/interop.html +++ /dev/null @@ -1,1802 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>FreeS/WAN interoperation Grid</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, interoperation"> - <!-- - - Written by Claudia Schmeing for the Linux FreeS/WAN project - With notes from Sandy Harris. - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: interop.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<A NAME="interop"></A><H1>Interoperating with FreeS/WAN</H1> - - -<P>The FreeS/WAN project needs you! We rely on the user community to keep -up to date. Mail users@lists.freeswan.org with your -interop success stories.</P> - -<P><STRONG>Please note</STRONG>: Most of our interop examples feature -Linux FreeS/WAN 1.x config files. You can convert them to 2.x files fairly -easily with the patch in our -<A HREF="upgrading.html#ipsec.conf_v2">Upgrading Guide</A>. -</P> - -<H2>Interop at a Glance</H2> - - - -<TABLE BORDER="1"> - -<TR> -<TD> </TD> -<TD colspan="5">FreeS/WAN VPN</TD> -<TD>Road Warrior</TD> -<TD>OE</TD> -</TR> - -<TR> -<TD> </TD> -<TD>PSK</TD> -<TD>RSA Secret</TD> -<TD>X.509<BR><SMALL><A HREF="#interoprules">(requires patch)</A></SMALL></TD> -<TD>NAT-Traversal<BR><SMALL><A HREF="#interoprules">(requires patch)</A></SMALL></TD> -<TD>Manual<BR>Keying</TD> -<TD> </TD> -<TD> </TD> -</TR> - - -<TR><TD colspan="8">More Compatible</TD></TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#freeswan">FreeS/WAN</A> -<A NAME="freeswan.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#isakmpd">isakmpd (OpenBSD)</A> -<A NAME="isakmpd.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD><FONT color="#cc0000">No </FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#kame">Kame (FreeBSD, -<BR>NetBSD, MacOSX) -<BR> <SMALL>aka racoon</SMALL></A> -<A NAME="kame.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#mcafee">McAfee VPN<BR><SMALL>was PGPNet</SMALL></A> -<A NAME="mcafee.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#microsoft">Microsoft <BR>Windows 2000/XP</A> -<A NAME="microsoft.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> -<TR> -<TD><A HREF="#ssh">SSH Sentinel</A> -<A NAME="ssh.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#cccc00">Maybe</FONT></TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#safenet">Safenet SoftPK<BR>/SoftRemote</A> -<A NAME="safenet.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - - -<TR><TD colspan="8">Other</TD></TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#6wind">6Wind</A> -<A NAME="6wind.top"> </A></TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#alcatel">Alcatel Timestep</A> -<A NAME="alcatel.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#apple">Apple Macintosh<br>System 10+</A> -<A NAME="apple.top"> </A></TD> -<TD><FONT color="#cccc00">Maybe</FONT></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#cccc00">Maybe</FONT></TD> -<TD> </TD> -<TD><FONT color="#cccc00">Maybe</FONT></TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#ashleylaurent">AshleyLaurent <BR>VPCom</A> -<A NAME="ashleylaurent.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#borderware">Borderware</A> -<A NAME="borderware.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - -<!-- -http://www.cequrux.com/vpn-guides.php3 -"coming soon" guide to connect with FreeS/WAN. ---> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#checkpoint">Check Point FW-1/VPN-1</A> -<A NAME="checkpoint.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#cisco">Cisco with 3DES</A> -<A NAME="cisco.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#cccc00">Maybe</FONT></TD> -<TD> </TD> -<TD><FONT color="#cccc00">Maybe</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#equinux">Equinux VPN Tracker <BR> -(for Mac OS X) -</A> -<A NAME="equinux.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD><FONT color="#cccc00">Maybe</FONT></TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#fsecure">F-Secure</A> -<A NAME="fsecure.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cccc00">Maybe</FONT></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#gauntlet">Gauntlet GVPN</A> -<A NAME="gauntlet.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#aix">IBM AIX</A> -<A NAME="aix.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD><FONT color="#cccc00">Maybe</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#as400">IBM AS/400</A> -<A NAME="as400"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#intel">Intel Shiva<BR>LANRover/Net Structure</A> -<A NAME="intel.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#lancom">LanCom (formerly ELSA)</A> -<A NAME="lancom.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#linksys">Linksys</A> -<A NAME="linksys.top"> </A></TD> -<TD><FONT color="#cccc00">Maybe</FONT></TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#lucent">Lucent</A> -<A NAME="lucent.top"> </A></TD> -<TD><FONT color="#cccc00">Partial</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#netasq">Netasq</A> -<A NAME="netasq.top"> </A></TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#netcelo">netcelo</A> -<A NAME="netcelo.top"> </A></TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#netgear">Netgear fvs318</A> -<A NAME="netgear.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#netscreen">Netscreen 100<BR>or 5xp</A> -<A NAME="netscreen.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cccc00">Maybe</FONT></TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#nortel">Nortel Contivity</A> -<A NAME="nortel.top"> </A></TD> -<TD><FONT color="#cccc00">Partial</FONT></TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD><FONT color="#cccc00">Maybe</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#radguard">RadGuard</A> -<A NAME="radguard.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#raptor">Raptor</A> -<A NAME="raptor"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#redcreek">Redcreek Ravlin</A> -<A NAME="redcreek.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT><FONT color="#cccc00">/Partial</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#sonicwall">SonicWall</A> -<A NAME="sonicwall.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cccc00">Maybe</FONT></TD> -<TD><FONT color="#cc0000">No</FONT></TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#sun">Sun Solaris</A> -<A NAME="sun.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#symantec">Symantec</A> -<A NAME="symantec.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#watchguard">Watchguard <BR>Firebox</A> -<A NAME="watchguard.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#xedia">Xedia Access Point<BR>/QVPN</A> -<A NAME="xedia.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -<TR> -<TD><A HREF="#zyxel">Zyxel Zywall<BR>/Prestige</A> -<A NAME="zyxel.top"> </A></TD> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - - - - -<!-- PSK RSA X.509 NAT-T Manual RW OE - - -<TR> -<TD><A HREF="#sample">sample</A></TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD> </TD> -<TD><FONT color="#cc0000">No</FONT></TD> -</TR> - ---> - -<TR> -<TD> </TD> -<TD>PSK</TD> -<TD>RSA Secret</TD> -<TD>X.509<BR><SMALL><A HREF="#interoprules">(requires patch)</A></SMALL></TD> -<TD>NAT-Traversal<BR><SMALL><A HREF="#interoprules">(requires patch)</A></SMALL></TD> -<TD>Manual<BR>Keying</TD> -<TD> </TD> -<TD> </TD> -</TR> - -<TR> -<TD> </TD> -<TD colspan="5">FreeS/WAN VPN</TD> -<TD>Road Warrior</TD> -<TD>OE</TD> -</TR> - - - -<!-- PSK RSA X.509 NAT-T Manual RW OE --> - -</TABLE> - - - - -<H3>Key</H3> -<TABLE BORDER="1"> - -<TR> -<TD><FONT color="#00cc00">Yes</FONT></TD> -<TD>People report that this works for them.</TD> -</TR> - -<TR> -<TD>[Blank]</TD> -<TD>We don't know.</TD> -</TR> - -<TR> -<TD><FONT color="#cc0000">No</FONT></TD> -<TD>We have reason to believe -it was, at some point, not possible to get this to work.</TD> -</TR> - -<TR> -<TD><FONT color="#cccc00">Partial</FONT></TD> -<TD>Partial success. For example, a connection can be -created from one end only.</TD> -</TR> - -<TR> -<TD><FONT color="#00cc00">Yes</FONT><FONT color="#cccc00">/Partial</FONT></TD> -<TD>Mixed reports.</TD> -</TR> - - -<TR> -<TD><FONT color="#cccc00">Maybe</FONT></TD> -<TD>We think the answer is "yes", but need confirmation.</TD> -</TR> - - -</TABLE> - -<A NAME="interoprules"></A><h2>Basic Interop Rules</h2> - -<P>Vanilla -FreeS/WAN implements <A HREF="compat.html#compat">these parts</A> of the -IPSec specifications. You can add more with -<A HREF="http://www.freeswan.ca">Super FreeS/WAN</A>, -but what we offer may be enough for many users.</P> -<UL> -<LI> -To use X.509 certificates with FreeS/WAN, you will need -the <A HREF="http://www.strongsec.org/freeswan">X.509 patch</a> -or <A HREF="http://www.freeswan.ca">Super FreeS/WAN</A>, -which includes that patch.</LI> -<LI> -To use -<A HREF="glossary.html#NAT.gloss">Network Address Translation</A> -(NAT) traversal -with FreeS/WAN, you will need Arkoon Network Security's -<A HREF="http://open-source.arkoon.net">NAT traversal patch</A> -or <A HREF="http://www.freeswan.ca">Super FreeS/WAN</A>, which includes it. -</LI> -</UL> - - -<P>We offer a set of proposals which is not user-adjustable, but covers -all combinations that we can offer. -FreeS/WAN always proposes triple DES encryption and -Perfect Forward Secrecy (PFS). -In addition, we propose Diffie Hellman groups 5 and 2 -(in that order), and MD5 and SHA-1 hashes. -We accept the same proposals, in the same order of preference. -</P> - -<P>Other interop notes:</P> -<UL> -<LI> -A <A HREF="http://lists.freeswan.org/archives/users/2003-September/msg00462.html">SHA-1 -bug in FreeS/WAN 2.00, 2.01 and 2.02</A> may affect some -interop scenarios. It does not affect 1.x versions, and is fixed in 2.03 and -later. -</LI> -<LI> -Some other implementations will close a connection with FreeS/WAN -after some time. This may be a problem with rekey lifetimes. Please see -<A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00293.html"> -this tip</A> and -<A HREF="http://lists.freeswan.org/pipermail/users/2001-December/005758.html"> -this workaround</A>. -</LI> -</UL> - -<H2>Longer Stories</H2> - - -<H3>For <EM>More Compatible</EM> Implementations</H3> - - -<H4><A NAME="freeswan">FreeS/WAN</A></H4> - -<P> -See our documentation at <A HREF="http://www.freeswan.org">freeswan.org</A> -and the Super FreeS/WAN docs at -<A HREF="http://www.freeswan.ca">freeswan.ca</A>. -Some user-written HOWTOs for FreeS/WAN-FreeS/WAN connections -are listed in <A HREF="intro.html#howto">our Introduction</A>. -</P> - -<P>See also:</P> - -<UL> -<LI> -<A HREF="http://lugbe.ch/action/reports/ipsec_htbe.phtml">A German FreeS/WAN-FreeS/WAN page by Markus Wernig (X.509)</A> -</LI> -</UL> - - -<P><A HREF="#freeswan.top">Back to chart</A></P> - - -<H4><A NAME="isakmpd">isakmpd (OpenBSD)</A></H4> - -<P><A HREF="http://www.openbsd.org/faq/faq13.html">OpenBSD FAQ: Using IPsec</A><BR> -<A HREF="http://www.rommel.stw.uni-erlangen.de/~hshoexer/ipsec-howto/HOWTO.html">Hans-Joerg Hoexer's interop Linux-OpenBSD (PSK)</A><BR> -<A HREF="http://www.segfault.net/ipsec/">Skyper's configuration (PSK)</A> -<BR> -<A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> -French page with configs (X.509)</A> - - -</P> - -<P><A HREF="#isakmpd.top">Back to chart</A></P> - - -<H4><A NAME="kame">Kame</A></H4> - -<UL> -<LI>For FreeBSD and NetBSD. Ships with Mac OS X; see also our -<A HREF="#apple">Mac</A> section.</LI> -<LI>Also known as <EM>racoon</EM>, its keying daemon.</LI> -</UL> - -<P><A HREF="http://www.kame.net">Kame homepage, with FAQ</A><BR> -<A HREF="http://www.netbsd.org/Documentation/network/ipsec">NetBSD's IPSec FAQ</A><BR> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/12/msg00560.html">Ghislaine's post explaining some interop peculiarities</A> -</P> -<P> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/09/msg00511.html">Itojun's Kame-FreeS/WAN interop tips (PSK)</A><BR> -<A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2000">Ghislaine Labouret's French page with links to matching FreeS/WAN and Kame configs (RSA)</A><BR> -<A HREF="http://lugbe.ch/lostfound/contrib/freebsd_router/">Markus Wernig's -HOWTO (X.509, BSD gateway)</A><BR> -<A HREF="http://web.morgul.net/~frodo/docs/kame+freeswan_interop.html">Frodo's Kame-FreeS/WAN interop (X.509)</A><BR> -<A HREF="http://www.wavesec.org/kame.phtml">Kame as a WAVEsec client.</A> -</P> - -<P><A HREF="#kame.top">Back to chart</A></P> - - -<H4><A NAME="mcafee">PGPNet/McAfee</A></H4> - -<P> -<UL> -<LI>Now called McAfee VPN Client.</LI> -<LI>PGPNet also came in a freeware version which did not support subnets</LI> -<LI>To support dhcp-over-ipsec, you need the X.509 patch, which is included in -<A HREF="http://www.freeswan.ca">Super FreeS/WAN</A>. -</LI> -</UL> -<P> -<A HREF="http://www.freeswan.ca/docs/WindowsInterop">Tim Carr's Windows Interop Guide (X.509)</A><BR> -<A HREF="http://www.rommel.stw.uni-erlangen.de/~hshoexer/ipsec-howto/HOWTO.html#Interop2" ->Hans-Joerg Hoexer's Guide for Linux-PGPNet (PSK)</A><BR> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/04/msg00339.html">Kai Martius' instructions using RSA Key-Extractor Tool (RSA)</A><BR> - <A HREF="http://www.zengl.net/freeswan/english.html">Christian Zeng's page (RSA)</A> based on Kai's work. English or German.<BR> -<A HREF="http://tirnanog.ls.fi.upm.es/CriptoLab/Biblioteca/InfTech/InfTech_CriptoLab.htm"> -Oscar Delgado's PDF (X.509, no configs)</A><BR> -<A HREF="http://www-ec.njit.edu/~rxt1077/Howto.txt">Ryan's HOWTO for FreeS/WAN-PGPNet (X.509)</A>. Through a Linksys Router with IPsec Passthru enabled.<BR> -<A HREF="http://jixen.tripod.com/#RW-PGP-to-Fwan">Jean-Francois Nadeau's Practical Configuration (Road Warrior with PSK)</A><BR> -<A HREF="http://www.evolvedatacom.nl/freeswan.html#toc">Wouter Prins' HOWTO (Road Warrior with X.509)</A><BR> -</P> -<P> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/01/msg00271.html">Rekeying problem with FreeS/WAN and older PGPNets</A><BR> -</P> - -<P><A HREF="http://www.strongsec.com/freeswan/dhcprelay/index.htm"> -DHCP over IPSEC HOWTO for FreeS/WAN (requires X.509 and dhcprelay patches) -</A> -</P> - -<P><A HREF="#mcafee.top">Back to chart</A></P> - - -<H4><A NAME="microsoft">Microsoft Windows 2000/XP</A></H4> - -<UL> -<LI>IPsec comes with Win2k, and with XP Support Tools. May require -<A HREF="http://www.microsoft.com/windows2000/downloads/recommended/encryption/default.asp"> High Encryption Pack</A>. WinXP users have also reported better -results with Service Pack 1.</LI> -<LI>The Road Warrior setup works either way round. Windows (XP or 2K) IPsec -can connect as a Road Warrior to FreeS/WAN. -However, FreeS/WAN can also successfully connect as a Road -Warrior to Windows IPsec (see Nate Carlson's configs below).</LI> -<LI>FreeS/WAN version 1.92 or later is required to avoid an interoperation -problem with Windows native IPsec. Earlier FreeS/WAN versions -did not process the Commit Bit as Windows native IPsec expected.</LI> -</UL> - -<P> -<A HREF="http://www.freeswan.ca/docs/WindowsInterop">Tim Carr's Windows Interop Guide (X.509)</A><BR> - -<A HREF="http://ipsec.math.ucla.edu/services/ipsec.html">James Carter's -instructions (X.509, NAT-T)</A><BR> - -<A HREF="http://jixen.tripod.com/#Win2000-Fwan"> -Jean-Francois Nadeau's Net-net Configuration (PSK)</A><BR> - -<A HREF="http://security.nta.no/freeswan-w2k.html"> -Telenor's Node-node Config (Transport-mode PSK)</A><BR> - -<A HREF="http://vpn.ebootis.de">Marcus Mueller's HOWTO using his VPN config tool (X.509).</A> Tool also works with PSK.<BR> - -<A HREF="http://www.natecarlson.com/include/showpage.php?cat=linux&page=ipsec-x509"> -Nate Carlson's HOWTO using same tool (Road Warrior with X.509)</A>. Unusually, -FreeS/WAN is the Road Warrior here.<BR> - -<A HREF="http://tirnanog.ls.fi.upm.es/CriptoLab/Biblioteca/InfTech/InfTech_CriptoLab.htm"> -Oscar Delgado's PDF (X.509, no configs)</A><BR> - -<A HREF="http://lists.freeswan.org/pipermail/users/2003-July/022425.html">Tim Scannell's Windows XP Additional Checklist (X.509)</A><BR> -</P> - -<!-- Note to self: Include L2TP references? --> - -<P> -<A HREF="http://www.microsoft.com/windows2000/en/server/help/default.asp?url=/windows2000/en/server/help/sag_TCPIP_ovr_secfeatures.htm"> -Microsoft's page on Win2k TCP/IP security features</A><BR> - -<A HREF="http://support.microsoft.com/support/kb/articles/Q257/2/25.ASP"> -Microsoft's Win2k IPsec debugging tips</A><BR> - -<!-- Alt-URL http://support.microsoft.com/default.aspx?scid=kb;EN-US;q257225 -Perhaps newer? --> - -<A HREF="http://www.wired.com/news/technology/0,1282,36336,00.html">MS VPN may fall back to 1DES</A> -</P> - -<P><A HREF="#microsoft.top">Back to chart</A></P> - - -<H4><A NAME="ssh">SSH Sentinel</A></H4> - -<UL> -<LI>Popular and well tested.</LI> -<LI>Also rebranded in <A HREF="http://www.zyxel.com">Zyxel Zywall</A>. -Our Zyxel interop notes are <A HREF="#zyxel">here</A>.</LI> -<LI> -SSH supports IPsec-over-UDP NAT traversal. -</LI> -<LI>There is this -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/12/msg00370.html"> -potential problem</A> if you're not using the Legacy Proposal option. -</UL> - -<P> -<A HREF="http://www.ssh.com/support/sentinel/documents.cfm">SSH's Sentinel-FreeSWAN interop PDF (X.509)</A><BR> -<A HREF="http://www.nadmm.com/show.php?story=articles/vpn.inc">Nadeem Hassan's -SUSE-to-Sentinel article (Road warrior with X.509)</A><BR> -<A HREF="http://www.zerozone.it/documents/Linux/HowTo/VPN-IPsec-Freeswan-HOWTO.html">O-Zone's Italian HOWTO (Road Warrior, X.509, DHCP)</A><BR> -</P> - - -<P><A HREF="#ssh.top">Back to chart</A></P> - - - -<H4><A NAME="safenet">Safenet SoftPK/SoftRemote</A></H4> - -<UL> -<LI>People recommend SafeNet as a low cost Windows client.</LI> -<LI>SoftRemote seems to be the newer name for SoftPK.</LI> -</UL> - -<P> -<A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005061.html"> -Whit Blauvelt's SoftRemote tips</A><BR> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-October/015591.html"> -Tim Wilson's tips (X.509)</A> -<A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00607.html">Workaround for a "gotcha"</A> -</P> - -<P> -<A HREF="http://jixen.tripod.com/#Rw-IRE-to-Fwan">Jean-Francois Nadeau's -Practical Configuration (Road Warrior with PSK)</A><BR> -<A HREF="http://www.terradoncommunications.com/security/whitepapers/safe_net-to-free_swan.pdf"> -Terradon Communications' PDF (Road Warrior with PSK)</A><BR> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-October/?????.html"> -Seaan.net's PDF (Road Warrior to Subnet, with PSK) -</A><BR> -<A HREF="http://www.redbaronconsulting.com/freeswan/fswansafenet.pdf"> -Red Baron Consulting's PDF (Road Warrior with X.509)</A> -</P> - -<P><A HREF="#safenet.top">Back to chart</A></P> - - - - - - - - -<H3>For <EM>Other Implementations</EM></H3> - - - -<H4><A NAME="6wind">6Wind</A></H4> - -<P> - -<A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> -French page with configs (X.509)</A> - -</P> - -<P><A HREF="#6wind.top">Back to chart</A></P> - - - -<H4><A NAME="alcatel">Alcatel Timestep</A></H4> - -<P> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-June/011878.html"> -Alain Sabban's settings (PSK or PSK road warrior; through static NAT)</A><BR> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/1999/06/msg00100.html"> -Derick Cassidy's configs (PSK)</A><BR> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/1999/08/msg00194.html"> -David Kerry's Timestep settings (PSK)</A> -<BR> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-August/013711.html"> -Kevin Gerbracht's ipsec.conf (X.509)</A> -</P> - -<P><A HREF="#alcatel.top">Back to chart</A></P> - - - -<H4><A NAME="apple">Apple Macintosh System 10+</A></H4> - -<UL> -<LI>Since the system is based on FreeBSD, this should -interoperate <A HREF="#kame">just like FreeBSD</A>. -</LI> - -<LI> -To use Appletalk over IPsec tunnels, -<A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005116.html">run -it over TCP/IP</A>, or use -Open Door Networks' Shareway IP tool, -<A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005426.html">described -here.</A> -</LI> - -<LI>See also the <A HREF="#equinux">Equinux VPN Tracker</A> -for Mac OS X.</LI> -</UL> - - -<P> -<A HREF="http://ipsec.math.ucla.edu/services/ipsec.html">James Carter's -instructions (X.509, NAT-T)</A> -</P> - - -<P><A HREF="#apple.top">Back to chart</A></P> - - - - - - -<H4><A NAME="ashleylaurent">AshleyLaurent VPCom</A></H4> - -<P> -<A HREF="http://www.ashleylaurent.com/newsletter/01-28-00.htm"> -Successful interop report, no details</A> -</P> - -<P><A HREF="#ashleylaurent.top">Back to chart</A></P> - - -<H4><A NAME="borderware">Borderware</A></H4> - -<UL> -<LI>I suspect the Borderware client is a rebranded Safenet. -If that's true, our <A HREF="#safenet">Safenet section</A> will help.</LI> -</UL> - -<P> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-March/008288.html"> -Philip Reetz' configs (PSK)</A><BR> - -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/09/msg00217.html"> -Borderware server does not support FreeS/WAN road warriors</A><BR> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-February/007733.html"> -Older Borderware may not support Diffie Hellman groups 2, 5</A><BR> -</P> - - -<P><A HREF="#borderware.top">Back to chart</A></P> - - - -<H4><A NAME="checkpoint">Check Point VPN-1 or FW-1</A></H4> - -<UL> -<LI> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00099.html"> -Caveat about IP-range inclusion on Check Point.</A> -</LI> -<LI> -Some versions of Check Point may require an aggressive mode patch to -interoperate with FreeS/WAN.<BR> -<A HREF="http://www.freeswan.ca/code/super-freeswan">Super FreeS/WAN</A> -now features this patch. -<!-- -<A HREF="http://www.freeswan.ca/patches/aggressivemode">Steve Harvey's -aggressive mode patch for FreeS/WAN 1.5</A> ---> -</LI> -<LI> -<LI>A Linux FreeS/WAN-Checkpoint connection may close after some time. Try -<A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00293.html">this tip</A> toward a workaround. -</LI> -</UL> - -<P> -<A HREF="http://www.fw-1.de/aerasec/ng/vpn-freeswan/CPNG+Linux-FreeSWAN.html"> -AERAsec's Firewall-1 NG site (PSK, X.509, Road Warrior with X.509, -other algorithms)</A><BR> - -<A HREF="http://www.fw-1.de/aerasec/ng/vpn-freeswan/CPNG+Linux-FreeSWAN.html#support-matrix"> -AERAsec's detailed Check Point-FreeS/WAN support matrix</A><BR> -<A HREF="http://support.checkpoint.com/kb/docs/public/firewall1/4_1/pdf/fw-linuxvpn.pdf">Checkpoint.com PDF: Linux as a VPN Client to FW-1 (PSK)</A><BR> - -<A HREF="http://www.phoneboy.com">PhoneBoy's Check Point FAQ (on Check Point -only, not FreeS/WAN)</A><BR> - -</P> - -<P> -<A HREF="http://lists.freeswan.org/pipermail/users/2001-August/002351.html">Chris -Harwell's tips & FreeS/WAN configs (PSK)</A><BR> - -<A HREF="http://lists.freeswan.org/pipermail/users/2002-April/009362.html">Daniel -Tombeil's configs (PSK)</A> - -</P> - -<P><A HREF="#checkpoint.top">Back to chart</A></P> - - -<H4><A NAME="cisco">Cisco</A></H4> - -<UL> -<LI> -Cisco supports IPsec-over-UDP NAT traversal. -</LI> -<LI>Cisco VPN Client appears to use nonstandard IPsec and -does not work with FreeS/WAN. <A HREF="https://mj2.freeswan.org/archives/2003-August/maillist.html">This message</A> concerns Cisco VPN Client 4.01. -<!-- fix link --> -</LI> -<LI>A Linux FreeS/WAN-Cisco connection may close after some time. -<A HREF="http://lists.freeswan.org/pipermail/users/2001-December/005758.html"> -Here</A> -is a workaround, and -<A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00293.html">here</A> - is another comment on the same subject.</LI> -<LI><A HREF="http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t2/3desips.htm">Older Ciscos</A> -purchased outside the United States may not have 3DES, which FreeS/WAN requires.</LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2001-June/000406.html">RSA keying may not be possible between Cisco and FreeS/WAN.</A> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2001-October/004357.html">In -ipsec.conf, VPN3000 DN (distinguished name) must be in binary (X.509 only)</A></LI> - - -</UL> - - -<P> -<A HREF="http://rr.sans.org/encryption/cisco_router.php">SANS Institute HOWTO (PSK).</A> Detailed, with extensive references.<BR> -<A HREF="http://www.worldbank.ro/IPSEC/cisco-linux.txt">Short HOWTO (PSK)</A><BR> -<A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> -French page with configs for Cisco IOS, PIX and VPN 3000 (X.509)</A> -<BR> - -<A HREF="http://lists.freeswan.org/pipermail/users/2001-August/002966.html">Dave -McFerren's sample configs (PSK)</A><BR> -<A HREF="http://lists.freeswan.org/pipermail/users/2001-September/003422.html">Wolfgang -Tremmel's sample configs (PSK road warrior)</A><BR> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/11/msg00578.html"> -Old doc from Pete Davis, with William Watson's updated Tips (PSK)</A><BR> -</P> - -<P><STRONG>Some PIX specific information:</STRONG><BR> - -<A HREF="http://www.wlug.org.nz/FreeSwanToCiscoPix"> -Waikato Linux Users' Group HOWTO. Nice detail (PSK) -</A><BR> -<A HREF="http://www.johnleach.co.uk/documents/freeswan-pix/freeswan-pix.html"> -John Leach's configs (PSK) -</A><BR> -<A HREF="http://www.diverdown.cc/vpn/freeswanpix.html"> -Greg Robinson's settings (PSK) -</A><BR> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-February/007901.html"> -Scott's ipsec.conf for PIX (PSK, FreeS/WAN side only)</A><BR> -<A HREF="http://lists.freeswan.org/pipermail/users/2001-October/003949.html">Rick -Trimble's PIX and FreeS/WAN settings (PSK)</A><BR> -</P> - - - -<P><A href="http://www.cisco.com/public/support/tac"> -Cisco VPN support page</A><BR> -<A href="http://www.ieng.com/warp/public/707/index.shtml#ipsec"> -Cisco IPsec information page</A> -</P> - -<P><A HREF="#cisco.top">Back to chart</A></P> - - - - -<H4><A NAME="equinux">Equinux VPN tracker (for Mac OS X)</A></H4> - -<UL> -<LI>Graphical configurator for Mac OS X IPsec. May be an interface -to the <A HREF="#apple">native Mac OS X IPsec</A>, which is essentially -<A HREF="#kame">KAME</A>.</LI> -<LI>To use Appletalk over IPsec tunnels, -<A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005116.html">run -it over TCP/IP</A>, or use -Open Door Networks' Shareway IP tool, -<A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005426.html">described -here.</A> </LI> -</UL> - - -<P> -Equinux provides <A HREF="http://www.equinux.com/download/HowTo_FreeSWAN.pdf">this -excellent interop PDF</A> (PSK, RSA, X.509). -</P> - -<P><A HREF="#equinux.top">Back to chart</A></P> - - -<H4><A NAME="fsecure">F-Secure</A></H4> - -<UL> -<LI> -<!-- <A HREF="http://lists.freeswan.org/pipermail/users/2002-February/007596.html"> --> -F-Secure supports IPsec-over-UDP NAT traversal. -</LI> -</UL> - -<P><A HREF="http://www.pingworks.de/tech/vpn/vpn.txt">pingworks.de's - "Connecting F-Secure's VPN+ to Linux FreeS/WAN" (PSK road warrior)</A><BR> - <A HREF="http://www.pingworks.de/tech/vpn/vpn.pdf">Same thing as PDF</A><BR> -<A HREF="http://www.exim.org/pipermail/linux-ipsec/Week-of-Mon-20010122/000061.html">Success report, no detail (PSK)</A><BR> -<A HREF="http://www.exim.org/pipermail/linux-ipsec/Week-of-Mon-20010122/000041.html">Success report, no detail (Manual)</A> -</P> - -<!-- Other NAT traversers: -http://lists.freeswan.org/pipermail/users/2002-April/009136.html -and ssh sentinel: -http://lists.freeswan.org/pipermail/users/2001-September/003108.html ---> - -<P><A HREF="#fsecure.top">Back to chart</A></P> - - - -<H4><A NAME="gauntlet">Gauntlet GVPN</A></H4> - -<P> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/11/msg00535.html">Richard Reiner's ipsec.conf (PSK)</A> -<BR> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-June/011434.html"> -Might work without that pesky firewall... (PSK)</A><BR> -<!-- insert archive link --> -In late July, 2003 Alexandar Antik reported success interoperating -with Gauntlet 6.0 for Solaris (X.509). Unfortunately the message is not -properly archived at this time. -</P> - -<P><A HREF="#gauntlet.top">Back to chart</A></P> - - - -<H4><A NAME="aix">IBM AIX</A></H4> - -<P><A HREF="http://www-1.ibm.com/servers/esdd/articles/security.html"> -IBM's "Built-In Network Security with AIX" (PSK, X.509)</A><BR> -<A HREF="http://www-1.ibm.com/servers/aix/products/ibmsw/security/vpn/faqandtips/#ques20"> -IBM's tip: importing Linux FreeS/WAN settings into AIX's <VAR>ikedb</VAR> -(PSK)</A> -</P> - -<P><A HREF="#aix.top">Back to chart</A></P> - - - -<H4><A NAME="as400">IBM AS/400</A></H4> - -<UL> -<LI> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-April/009106.html">Road - Warriors may act flaky</A>. -</LI> -</UL> - -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-September/014264.html"> -Richard Welty's tips and tricks</A><BR> -</P> - -<P><A HREF="#as400.top">Back to chart</A></P> - - - -<H4><A NAME="intel">Intel Shiva LANRover / Net Structure</A></H4> - -<UL> -<LI>Intel Shiva LANRover is now known as Intel Net Structure.</LI> -<LI> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/01/msg00298.html"> -Shiva seems to have two modes: IPsec or the proprietary -"Shiva Tunnel".</A> -Of course, FreeS/WAN will only create IPsec tunnels. -</LI> - -<LI> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00293.html"> -AH may not work for Shiva-FreeS/WAN.</A> -That's OK, since FreeS/WAN has phased out the use of AH. -</LI> -</UL> - -<P> -<A HREF="http://snowcrash.tdyc.com/freeswan/"> -Snowcrash's configs (PSK)</A><BR> - -<A HREF="http://www.opus1.com/vpn/index.html"> -Old configs from an interop (PSK)</A><BR> - -<A HREF="http://lists.freeswan.org/pipermail/users/2001-October/003831.html"> -The day Shiva tickled a Pluto bug (PSK)</A><BR> - - -<A HREF="http://lists.freeswan.org/pipermail/users/2001-October/004270.html"> -Follow up: success!</A> -</P> - -<P><A HREF="#intel.top">Back to chart</A></P> - - - -<H4><A NAME="lancom">LanCom (formerly ELSA)</A></H4> - -<UL> -<LI>This router is popular in Germany. -</UL> - -<P> -Jakob Curdes successfully created a PSK connection with the LanCom 1612 in -August 2003. -<!-- add ML link when it appears --> -</P> - -<P><A HREF="#lancom.top">Back to chart</A></P> - - - -<H4><A NAME="linksys">Linksys</A></H4> - -<UL> -<LI>Linksys may be used as an IPsec tunnel endpoint, <STRONG>OR</STRONG> -as a router in "IPsec passthrough" mode, so that the IPsec tunnel -passes through the Linksys. -</LI> -</UL> - -<H5>As tunnel endpoint</H5> -<P> -<A HREF="http://www.freeswan.ca/docs/BEFVP41/"> -Ken Bantoft's instructions (Road Warrior with PSK)</A><BR> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-February/007814.html"> -Nate Carlson's caveats</A> -</P> - -<H5>In IPsec passthrough mode</H5> -<P> -<A HREF="http://www-ec.njit.edu/~rxt1077/Howto.txt"> -Sample HOWTO through a Linksys Router</A><BR> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2002/02/msg00114.html"> -Nadeem Hasan's configs</A><BR> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2002/02/msg00180.html"> -Brock Nanson's tips</A><BR> -</P> - -<P><A HREF="#linksys.top">Back to chart</A></P> - - -<H4><A NAME="lucent">Lucent</A></H4> - -<P> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-May/010976.html"> -Partial success report; see also the next message in thread</A> -</P> -<!-- section done --> - -<P><A HREF="#lucent.top">Back to chart</A></P> - - -<H4><A NAME="netasq">Netasq</A></H4> - -<P> -<A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> -French page with configs (X.509)</A> - -</P> -<!-- section done --> - -<P><A HREF="#netasq.top">Back to chart</A></P> - - - -<H4><A NAME="netcelo">Netcelo</A></H4> - -<P> -<A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> -French page with configs (X.509)</A> - -<!-- section done --> - -</P> - -<P><A HREF="#netcelo.top">Back to chart</A></P> - - - -<H4><A NAME="netgear">Netgear fvs318</A></H4> - -<UL> -<LI>With a recent Linux FreeS/WAN, you will require the latest -(12/2002) Netgear firmware, which supports Diffie-Hellman (DH) group 2. -For security reasons, we phased out DH 1 after Linux FreeS/WAN 1.5. -</LI> -<LI> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-June/011833.html"> -This message</A> reports the incompatibility between Linux FreeS/WAN 1.6+ -and Netgear fvs318 without the firmware upgrade. -</LI> -<LI>We believe Linux FreeS/WAN 1.5 and earlier will interoperate with -any NetGear firmware. -</LI> -</UL> - -<P> -<A HREF="http://lists.freeswan.org/pipermail/users/2003-February/017891.html"> -John Morris' setup (PSK)</A> -</P> - -<P><A HREF="#netgear.top">Back to chart</A></P> - - - -<H4><A NAME="netscreen">Netscreen 100 or 5xp</A></H4> - -<P> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-August/013409.html"> -Errol Neal's settings (PSK)</A><BR> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-October/015265.html"> -Corey Rogers' configs (PSK, no PFS)</A><BR> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-August/013051.html"> -Jordan Share's configs (PSK, 2 subnets, through static NAT)</A><BR> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/08/msg00404.html"> -Set src proxy_id to your protected subnet/mask</A><BR> - -<A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> -French page with ipsec.conf, Netscreen screen shots (X.509, may -need to revert to PSK...)</A> - -</P> -<P> -<A HREF="http://archives.neohapsis.com/archives/sf/linux/2001-q2/0123.html"> -A report of a company using Netscreen with FreeS/WAN on a large scale -(FreeS/WAN road warriors?)</A> -</P> - -<P><A HREF="#netscreen.top">Back to chart</A></P> - - - -<H4><A NAME="nortel">Nortel Contivity</A></H4> - -<UL> -<LI> -Nortel supports IPsec-over-UDP NAT traversal. -</LI> - -<LI> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00417.html"> -Some older versions of Contivity and FreeS/WAN will not communicate.</A> -</LI> - -<LI> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-May/010924.html"> -FreeS/WAN cannot be used as a "client" to a Nortel Contivity server, -but can be used as a branch-office tunnel.</A> -</LI> - -<!-- Probably obsoleted by Ken's post -<LI> -(Matthias siebler from old interop) -At one point you could not configure Nortel-FreeS/WAN tunnels as -"Client Tunnels" since FreeS/WAN does not support Aggressive Mode. -Current status of this problem: unknown. -<LI> -<A HREF="http://lists.freeswan.org/pipermail/users/2001-November/004612.html"> -How do we map group and user passwords onto the data that FreeS/WAN wants? -</A> -</LI> ---> - -<LI> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-October/015455.html"> -Contivity does not send Distinguished Names in the order FS wants them (X.509). -</A> -</LI> - -<LI> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/03/msg00137.html"> -Connections may time out after 30-40 minutes idle.</A> -</LI> - -</UL> - -<P> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/03/msg00137.html"> -JJ Streicher-Bremer's mini HOWTO for old & new software. (PSK with two subnets) -</A><BR> -<A HREF="http://www.hsc.fr/ressources/ipsec/ipsec2001/#config"> -French page with configs (X.509)</A>. This succeeds using the above X.509 tip. -</P> - -<!-- I could do more searching but this is a solid start. --> - -<P><A HREF="#nortel.top">Back to chart</A></P> - - -<H4><A NAME="radguard">Radguard</A></H4> - -<P> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/05/msg00009.html"> -Marko Hausalo's configs (PSK).</A> Note: These do create a connection, -as you can see by "IPsec SA established".<BR> - -<A HREF="http://lists.freeswan.org/pipermail/users/2002-October/???.html"> -Claudia Schmeing's comments</A> -</P> - -<P><A HREF="#radguard.top">Back to chart</A></P> - - -<H4><A NAME="raptor">Raptor (NT or Solaris)</A></H4> - -<P> - -<UL> -<LI>Now known as Symantec Enterprise Firewall.</LI> -<LI>The Raptor does not normally come with X.509, but this may be available as -an add-on.</LI> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2002-May/010256.html"> -Raptor requires alphanumberic PSK values, whereas FreeS/WAN uses hex.</A> -</LI> -<LI>Raptor's tunnel endpoint may be a host, subnet or group of subnets -(see -<A HREF="http://lists.freeswan.org/pipermail/design/2001-November/001295.html"> -this message</A> -). FreeS/WAN cannot handle the group of subnets; you -must create separate connections for each in order to interoperate.</LI> -<LI> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-May/010113.html"> -Some versions of Raptor accept only single DES. -</A> -According to this German message, -<A HREF="http://radawana.cg.tuwien.ac.at/mail-archives/lll/200012/msg00065.html"> -the Raptor Mobile Client demo offers single DES only.</A> -</LI> -</UL> - -<P> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-January/006935.html"> -Peter Mazinger's settings (PSK)</A><BR> - -<A HREF="http://lists.freeswan.org/pipermail/users/2001-November/005522.html"> -Peter Gerland's configs (PSK)</A><BR> - -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/07/msg00597.html"> -Charles Griebel's configs (PSK).</A><BR> - -<A HREF="http://lists.freeswan.org/pipermail/users/2002-July/012275.html"> -Lumir Srch's tips (PSK) -</A> -</P> - -<P> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/05/msg00214.html"> -John Hardy's configs (Manual)</A><BR> - -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/01/msg00236.html"> -Older Raptors want 3DES keys in 3 parts (Manual).</A><BR> - -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/06/msg00480.html"> -Different keys for each direction? (Manual)</A><BR> - -</P> - -<P><A HREF="#raptor.top">Back to chart</A></P> - - - -<H4><A NAME="redcreek">Redcreek Ravlin</A></H4> - -<UL> -<LI>Known issue #1: The Ravlin expects a quick mode renegotiation right -after every Main Mode negotiation. -</LI> -<LI> -Known issue #2: The Ravlin tries to negotiate a zero -connection lifetime, which it takes to mean "infinite". -<A HREF="http://www.bear-cave.org.uk/linux/ravlin/">Jim Hague's patch</A> -addresses both issues. -</LI> -<LI> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/03/msg00191.html"> -Interop works with Ravlin Firmware > 3.33. Includes tips (PSK).</A> -</LI> -</UL> - -<P><A HREF="#redcreek.top">Back to chart</A></P> - - - -<H4><A NAME="sonicwall">SonicWall</A></H4> - -<UL> -<LI><A HREF="http://lists.freeswan.org/pipermail/users/2001-June/000998.html"> -Sonicwall cannot be used for Road Warrior setups</A></LI> -<LI> -At one point, <A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/05/msg00217.html"> -only Sonicwall PRO supported triple DES</A>.</LI> -<LI> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-March/008600.html"> -Older Sonicwalls (before Nov 2001) feature Diffie Hellman group 1 -only</A>.</LI> -</UL> - -<P> -<A HREF="http://www.xinit.cx/docs/freeswan.html">Paul Wouters' config (PSK)</A><BR> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00073.html"> -Dilan Arumainathan's configuration (PSK)</A><BR> -<A HREF="http://www.gravitas.co.uk/vpndebug">Dariush's setup... only opens -one way (PSK)</A><BR> -<A HREF="http://lists.freeswan.org/pipermail/users/2003-July/022302.html"> -Andreas Steffen's tips (X.509)</A><BR> - -</P> - -<P><A HREF="#sonicwall.top">Back to chart</A></P> - - - -<H4><A NAME="sun">Sun Solaris</A></H4> - -<UL> -<LI> -Solaris 8+ has a native (in kernel) IPsec implementation. -</LI> -<LI> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-May/010503.html"> -Solaris does not seem to support tunnel mode, but you can make -IP-in-IP tunnels instead, like this.</A> -</LI> -</UL> -<P> - -<A HREF="http://lists.freeswan.org/pipermail/users/2003-June/022216.html">Reports of some successful interops</A> from a fellow @sun.com. -See also <A HREF="http://lists.freeswan.org/pipermail/users/2003-July/022247.html">these follow up posts</A>.<BR> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/03/msg00332.html"> -Aleks Shenkman's configs (Manual in transport mode) -</A><BR> -<!--sparc 64 stuff goes where?--> -</P> - -<P><A HREF="#solaris.top">Back to chart</A></P> - - - -<H4><A NAME="symantec">Symantec</A></H4> - -<UL> -<LI>The Raptor, covered <A HREF="#raptor">above</A>, is now known as -Symantec Enterprise Firewall.</LI> -<LI>Symantec's "distinguished name" is a KEY_ID. See Andreas Steffen's post, -below.</LI> -</UL> - -<P><A HREF="http://lists.freeswan.org/pipermail/users/2002-April/009037.html"> -Andreas Steffen's configs for Symantec 200R (PSK)</A> -</P> - -<P><A HREF="#symantec.top">Back to chart</A></P> - - - - -<H4><A NAME="watchguard">Watchguard Firebox</A></H4> - -<UL> -<LI>Automatic keying works with WatchGuard 5.0+ only.</LI> -<LI>Seen to interoperate with WatchGuard 1000, II, III; firmware v. 5, 6..</LI> -<LI>For manual keying, Watchguard's Policy Manager expects SPI numbers and -encryption and authentication keys in decimal (not hex).</LI> -</UL> - -<P> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-July/012595.html"> -WatchGuard's HOWTO (PSK)</A><BR> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-August/013342.html"> -Ronald C. Riviera's Settings (PSK)</A><BR> -<A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00179.html"> -Walter Wickersham's Notes (PSK)</A><BR> - -<A HREF="http://lists.freeswan.org/pipermail/users/2002-October/015587.html"> -Max Enders' Configs (Manual)</A> -</P> - -<P> -<A HREF="http://lists.freeswan.org/pipermail/users/2002-April/009404.html"> -Old known issue with auto keying</A><BR> - -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/02/msg00124.html"> -Tips on key generation and format (Manual)</A><BR> -</P> - -<P><A HREF="#watchguard.top">Back to chart</A></P> - - - -<H4><A NAME="xedia">Xedia Access Point/QVPN</A></H4> - -<P> -<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2001/12/msg00520.html"> -Hybrid IPsec/L2TP connection settings (X.509) -</A><BR> -<A HREF="http://www.sandelman.ottawa.on.ca/ipsec/1999/08/msg00140.html"> - Xedia's LAN-LAN links don't use multiple tunnels -</A><BR> - -<A HREF="http://www.sandelman.ottawa.on.ca/ipsec/1999/08/msg00140.html"> - That explanation, continued -</A> -</P> - -<P><A HREF="#xedia.top">Back to chart</A></P> - - - -<H4><A NAME="zyxel">Zyxel</A></H4> - -<UL> -<LI>The Zyxel Zywall is a rebranded SSH Sentinel box. See also our section -on <A HREF="#ssh">SSH</A>.</LI> -<LI>There seems to be a problem with keeping this connection alive. This is -caused at the Zyxel end. See this brief -<A HREF="http://lists.freeswan.org/archives/users/2003-October/msg00141.html"> -discussion and solution. -</A> -</LI> -</UL> -<P> -<A HREF="http://www.zyxel.com/support/supportnote/zywall/app/zw_freeswan.htm"> -Zyxel's Zywall to FreeS/WAN instructions (PSK)</A><BR> -<A HREF="http://www.zyxel.com/support/supportnote/p652/app/zw_freeswan.htm"> -Zyxel's Prestige to FreeS/WAN instructions (PSK)</A>. Note: not all Prestige -versions include VPN software.<BR> - -<A HREF="http://www.lancry.net/techdocs/freeswan-zyxel.txt">Fabrice Cahen's - HOWTO (PSK)</A><BR> - -</P> - -<P><A HREF="#zyxel.top">Back to chart</A></P> - - - -<!-- SAMPLE ENTRY - -<H4><A NAME="timestep">Timestep</A></H4> - -<P>Text goes here. -</P> - ---> -</BODY></HTML> - diff --git a/doc/src/intro.html b/doc/src/intro.html deleted file mode 100644 index 09c352c00..000000000 --- a/doc/src/intro.html +++ /dev/null @@ -1,887 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>Introduction to FreeS/WAN</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, introduction"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: intro.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1><a name="intro">Introduction</a></h1> - -<p>This section gives an overview of:</p> -<ul> - <li>what IP Security (IPsec) does</li> - <li>how IPsec works</li> - <li>why we are implementing it for Linux</li> - <li>how this implementation works</li> -</ul> - -<p>This section is intended to cover only the essentials, <em>things you -should know before trying to use FreeS/WAN.</em></p> - -<p>For more detailed background information, see the <a -href="politics.html#politics">history and politics</a> and -<a href="ipsec.html#ipsec.detail">IPsec protocols</a> sections.</p> - -<h2><a name="ipsec.intro">IPsec, Security for the Internet Protocol</a></h2> - -<p>FreeS/WAN is a Linux implementation of the IPsec (IP security) protocols. -IPsec provides <a href="glossary.html#encryption">encryption</a> and <a -href="glossary.html#authentication">authentication</a> services at the IP -(Internet Protocol) level of the network protocol stack.</p> - -<p>Working at this level, IPsec can protect any traffic carried over IP, -unlike other encryption which generally protects only a particular -higher-level protocol -- <a href="glossary.html#PGP">PGP</a> for mail, <a -href="glossary.html#SSH">SSH</a> for remote login, <a -href="glossary.html#SSL">SSL</a> for web work, and so on. This approach has -both considerable advantages and some limitations. For discussion, see our <a -href="ipsec.html#others">IPsec section</a></p> - -<p>IPsec can be used on any machine which does IP networking. Dedicated IPsec -gateway machines can be installed wherever required to protect traffic. IPsec -can also run on routers, on firewall machines, on various application -servers, and on end-user desktop or laptop machines.</p> - -<p>Three protocols are used</p> -<ul> - <li><a href="glossary.html#AH">AH</a> (Authentication Header) provides a - packet-level authentication service</li> - <li><a href="glossary.html#ESP">ESP</a> (Encapsulating Security Payload) - provides encryption plus authentication</li> - <li><a href="glossary.html#IKE">IKE</a> (Internet Key Exchange) negotiates - connection parameters, including keys, for the other two</li> -</ul> - -<p>Our implementation has three main parts:</p> -<ul> - <li><a href="glossary.html#KLIPS">KLIPS</a> (kernel IPsec) implements AH, - ESP, and packet handling within the kernel</li> - <li><a href="glossary.html#Pluto">Pluto</a> (an IKE daemon) implements IKE, - negotiating connections with other systems</li> - <li>various scripts provide an adminstrator's interface to the - machinery</li> -</ul> - -<p>IPsec is optional for the current (version 4) Internet Protocol. FreeS/WAN -adds IPsec to the Linux IPv4 network stack. Implementations of <a -href="glossary.html#ipv6.gloss">IP version 6</a> are required to include -IPsec. Work toward integrating FreeS/WAN into the Linux IPv6 stack has <a -href="compat.html#ipv6">started</a>.</p> - -<p>For more information on IPsec, see our -<a href="ipsec.html#ipsec.detail">IPsec protocols</a> section, -our collection of <a href="web.html#ipsec.link">IPsec -links</a> or the <a href="rfc.html#RFC">RFCs</a> which are the official -definitions of these protocols.</p> - -<h3><a name="intro.interop">Interoperating with other IPsec -implementations</a></h3> - -<p>IPsec is designed to let different implementations work together. We -provide:</p> -<ul> - <li>a <a href="web.html#implement">list</a> of some other - implementations</li> - <li>information on <a href="interop.html#interop">using FreeS/WAN - with other implementations</a></li> -</ul> - -<p>The VPN Consortium fosters cooperation among implementers and -interoperability among implementations. Their <a -href="http://www.vpnc.org/">web site</a> has much more information.</p> - -<h3><a name="advantages">Advantages of IPsec</a></h3> - -<p>IPsec has a number of security advantages. Here are some independently -written articles which discuss these:</p> - -<P> -<A HREF="http://www.sans.org/rr/">SANS institute papers</A>. See the section -on Encryption &VPNs. -<BR> -<A HREF="http://www.cisco.com/en/US/netsol/ns110/ns170/ns171/ns128/networking_solutions_white_papers_list.html">Cisco's -white papers on "Networking Solutions"</A>. -<BR> -<A HREF="http://iscs.sourceforge.net/HowWhyBrief/HowWhyBrief.html"> -Advantages of ISCS (Linux Integrated Secure Communications System; -includes FreeS/WAN and other software)</A>. - -</P> - - -<h3><a name="applications">Applications of IPsec</a></h3> - -<p>Because IPsec operates at the network layer, it is remarkably flexible and -can be used to secure nearly any type of Internet traffic. Two applications, -however, are extremely widespread:</p> -<ul> - <li>a <a href="glossary.html#VPN">Virtual Private Network</a>, or VPN, - allows multiple sites to communicate securely over an insecure Internet - by encrypting all communication between the sites.</li> - <li>"Road Warriors" connect to the office from home, or perhaps from a - hotel somewhere</li> -</ul> - -<p>There is enough opportunity in these applications that vendors are -flocking to them. IPsec is being built into routers, into firewall products, -and into major operating systems, primarily to support these applications. -See our <a href="web.html#implement">list</a> of implementations for -details.</p> - -<p>We support both of those applications, and various less common IPsec -applications as well, but we also add one of our own:</p> -<ul> - <li>opportunistic encryption, the ability to set up FreeS/WAN gateways so - that any two of them can encrypt to each other, and will do so whenever - packets pass between them.</li> -</ul> - -<p>This is an extension we are adding to the protocols. FreeS/WAN is the -first prototype implementation, though we hope other IPsec implementations -will adopt the technique once we demonstrate it. See <a href="#goals">project -goals</a> below for why we think this is important.</p> - -<p>A somewhat more detailed description of each of these applications is -below. Our <a href="quickstart.html#quick_guide">quickstart</a> section will -show you how to build each of them.</p> - -<h4><a name="makeVPN">Using secure tunnels to create a VPN</a></h4> - -<p>A VPN, or <strong>V</strong>irtual <strong>P</strong>rivate -<strong>N</strong>etwork lets two networks communicate securely when the only -connection between them is over a third network which they do not trust.</p> - -<p>The method is to put a security gateway machine between each of the -communicating networks and the untrusted network. The gateway machines -encrypt packets entering the untrusted net and decrypt packets leaving it, -creating a secure tunnel through it.</p> - -<p>If the cryptography is strong, the implementation is careful, and the -administration of the gateways is competent, then one can reasonably trust -the security of the tunnel. The two networks then behave like a single large -private network, some of whose links are encrypted tunnels through untrusted -nets.</p> - -<p>Actual VPNs are often more complex. One organisation may have fifty branch -offices, plus some suppliers and clients, with whom it needs to communicate -securely. Another might have 5,000 stores, or 50,000 point-of-sale devices. -The untrusted network need not be the Internet. All the same issues arise on -a corporate or institutional network whenever two departments want to -communicate privately with each other.</p> - -<p>Administratively, the nice thing about many VPN setups is that large parts -of them are static. You know the IP addresses of most of the machines -involved. More important, you know they will not change on you. This -simplifies some of the admin work. For cases where the addresses do change, -see the next section.</p> - -<h4><a name="road.intro">Road Warriors</a></h4> - -<p>The prototypical "Road Warrior" is a traveller connecting to home base -from a laptop machine. Administratively, most of the same problems arise for -a telecommuter connecting from home to the office, especially if the -telecommuter does not have a static IP address.</p> - -<p>For purposes of this document:</p> -<ul> - <li>anyone with a dynamic IP address is a "Road Warrior".</li> - <li>any machine doing IPsec processing is a "gateway". Think of the - single-user road warrior machine as a gateway with a degenerate subnet - (one machine, itself) behind it.</li> -</ul> - -<p>These require somewhat different setup than VPN gateways with static -addresses and with client systems behind them, but are basically not -problematic.</p> - -<p>There are some difficulties which appear for some road warrior -connections:</p> -<ul> - <li>Road Wariors who get their addresses via DHCP may have a problem. - FreeS/WAN can quite happily build and use a tunnel to such an address, - but when the DHCP lease expires, FreeS/WAN does not know that. The tunnel - fails, and the only recovery method is to tear it down and re-build - it.</li> - <li>If <a href="glossary.html#NAT.gloss">Network Address Translation</a> - (NAT) is applied between the two IPsec Gateways, this breaks IPsec. IPsec - authenticates packets on an end-to-end basis, to ensure they are not - altered en route. NAT rewrites packets as they go by. See our <a - href="firewall.html#NAT">firewalls</a> document for details.</li> -</ul> - -<p>In most situations, however, FreeS/WAN supports road warrior connections -just fine.</p> - -<h4><a name="opp.intro">Opportunistic encryption</a></h4> - -<p>One of the reasons we are working on FreeS/WAN is that it gives us the -opportunity to add what we call opportuntistic encryption. This means that -any two FreeS/WAN gateways will be able to encrypt their traffic, even if the -two gateway administrators have had no prior contact and neither system has -any preset information about the other.</p> - -<p>Both systems pick up the authentication information they need from the <a -href="glossary.html#DNS">DNS</a> (domain name service), the service they -already use to look up IP addresses. Of course the administrators must put -that information in the DNS, and must set up their gateways with -opportunistic encryption enabled. Once that is done, everything is automatic. -The gateways look for opportunities to encrypt, and encrypt whatever they -can. Whether they also accept unencrypted communication is a policy decision -the administrator can make.</p> - -<p>This technique can give two large payoffs:</p> -<ul> - <li>It reduces the administrative overhead for IPsec enormously. You - configure your gateway and thereafter everything is automatic. The need - to configure the system on a per-tunnel basis disappears. Of course, - FreeS/WAN allows specifically configured tunnels to co-exist with - opportunistic encryption, but we hope to make them unnecessary in most - cases.</li> - <li>It moves us toward a more secure Internet, allowing users to create an - environment where message privacy is the default. All messages can be - encrypted, provided the other end is willing to co-operate. See our <a - href="politics.html#politics">history and politics of cryptography</a> - section for discussion of why we think this is needed.</li> -</ul> - -<p>Opportunistic encryption is not (yet?) a standard part of the IPsec -protocols, but an extension we are proposing and demonstrating. For details -of our design, see <a href="#applied">links</a> below.</p> - -<p>Only one current product we know of implements a form of opportunistic -encryption. <a href="web.html#ssmail">Secure sendmail</a> will automatically -encrypt server-to-server mail transfers whenever possible.</p> - -<h3><a name="types">The need to authenticate gateways</a></h3> - -<p>A complication, which applies to any type of connection -- VPN, Road -Warrior or opportunistic -- is that a secure connection cannot be created -magically. <em>There must be some mechanism which enables the gateways to -reliably identify each other.</em> Without this, they cannot sensibly trust -each other and cannot create a genuinely secure link.</p> - -<p>Any link they do create without some form of <a -href="glossary.html#authentication">authentication</a> will be vulnerable to -a <a href="glossary.html#middle">man-in-the-middle attack</a>. If <a -href="glossary.html#alicebob">Alice and Bob</a> are the people creating the -connection, a villian who can re-route or intercept the packets can pose as -Alice while talking to Bob and pose as Bob while talking to Alice. Alice and -Bob then both talk to the man in the middle, thinking they are talking to -each other, and the villain gets everything sent on the bogus "secure" -connection.</p> - -<p>There are two ways to build links securely, both of which exclude the -man-in-the middle:</p> -<ul> - <li>with <strong>manual keying</strong>, Alice and Bob share a secret key - (which must be transmitted securely, perhaps in a note or via PGP or SSH) - to encrypt their messages. For FreeS/WAN, such keys are stored in the <a - href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a> file. Of course, if - an enemy gets the key, all is lost.</li> - <li>with <strong>automatic keying</strong>, the two systems authenticate - each other and negotiate their own secret keys. The keys are - automatically changed periodically.</li> -</ul> - -<p>Automatic keying is much more secure, since if an enemy gets one key only -messages between the previous re-keying and the next are exposed. It is -therefore the usual mode of operation for most IPsec deployment, and the mode -we use in our setup examples. FreeS/WAN does support manual keying for -special circumstanes. See this <a -href="adv_config.html#prodman">section</a>.</p> - -<p>For automatic keying, the two systems must authenticate each other during -the negotiations. There is a choice of methods for this:</p> -<ul> - <li>a <strong>shared secret</strong> provides authentication. If Alice and - Bob are the only ones who know a secret and Alice recives a message which - could not have been created without that secret, then Alice can safely - believe the message came from Bob.</li> - <li>a <a href="glossary.html#public">public key</a> can also provide - authentication. If Alice receives a message signed with Bob's private key - (which of course only he should know) and she has a trustworthy copy of - his public key (so that she can verify the signature), then she can - safely believe the message came from Bob.</li> -</ul> - -<p>Public key techniques are much preferable, for reasons discussed <a -href="config.html#choose">later</a>, and will be used in all our setup -examples. FreeS/WAN does also support auto-keying with shared secret -authentication. See this <a -href="adv_config.html#prodsecrets">section</a>.</p> - -<h2><a name="project">The FreeS/WAN project</a></h2> - -<p>For complete information on the project, see our web site, <a -href="http://liberty.freeswan.org">freeswan.org</a>.</p> - -<p>In summary, we are implementing the <a -href="glossary.html#IPsec">IPsec</a> protocols for Linux and extending them -to do <a href="glossary.html#carpediem">opportunistic encryption</a>.</p> - -<h3><a name="goals">Project goals</a></h3> - -<p>Our overall goal in FreeS/WAN is to make the Internet more secure and more -private.</p> - -<p>Our IPsec implementation supports VPNs and Road Warriors of course. Those -are important applications. Many users will want FreeS/WAN to build corporate -VPNs or to provide secure remote access.</p> - -<p>However, our goals in building it go beyond that. We are trying to help -<strong>build security into the fabric of the Internet</strong> so that -anyone who choses to communicate securely can do so, as easily as they can do -anything else on the net.</p> - -<p>More detailed objectives are:</p> -<ul> - <li>extend IPsec to do <a href="glossary.html#carpediem">opportunistic - encryption</a> so that - <ul> - <li>any two systems can secure their communications without a - pre-arranged connection</li> - <li><strong>secure connections can be the default</strong>, falling - back to unencrypted connections only if: - <ul> - <li><em>both</em> the partner is not set up to co-operate on - securing the connection</li> - <li><em>and</em> your policy allows insecure connections</li> - </ul> - </li> - <li>a significant fraction of all Internet traffic is encrypted</li> - <li>wholesale monitoring of the net (<a - href="politics.html#intro.poli">examples</a>) becomes difficult or - impossible</li> - </ul> - </li> - <li>help make IPsec widespread by providing an implementation with no - restrictions: - <ul> - <li>freely available in source code under the <a - href="glossary.html#GPL">GNU General Public License</a></li> - <li>running on a range of readily available hardware</li> - <li>not subject to US or other nations' <a - href="politics.html#exlaw">export restrictions</a>.<br> - Note that in order to avoid <em>even the appearance</em> of being - subject to those laws, the project cannot accept software - contributions -- <em>not even one-line bug fixes</em> -- from US - residents or citizens.</li> - </ul> - </li> - <li>provide a high-quality IPsec implementation for Linux - <ul> - <li>portable to all CPUs Linux supports: <a - href="compat.html#CPUs">(current list)</a></li> - <li>interoperable with other IPsec implementations: <a - href="interop.html#interop">(current list)</a></li> - </ul> - </li> -</ul> - -<p>If we can get opportunistic encryption implemented and widely deployed, -then it becomes impossible for even huge well-funded agencies to monitor the -net.</p> - -<p>See also our section on <a href="politics.html#politics">history and -politics</a> of cryptography, which includes our project leader's <a -href="politics.html#gilmore">rationale</a> for starting the project.</p> - -<h3><a name="staff">Project team</a></h3> - -<p>Two of the team are from the US and can therefore contribute no code:</p> -<ul> - <li>John Gilmore: founder and policy-maker (<a - href="http://www.toad.com/gnu/">home page</a>)</li> - <li>Hugh Daniel: project manager, Most Demented Tester, and occasionally - Pointy-Haired Boss</li> -</ul> - -<p>The rest of the team are Canadians, working in Canada. (<a -href="politics.html#status">Why Canada?</a>)</p> -<ul> - <li>Hugh Redelmeier: <a href="glossary.html#Pluto">Pluto daemon</a> - programmer</li> - <li>Richard Guy Briggs: <a href="glossary.html#KLIPS">KLIPS</a> - programmer</li> - <li>Michael Richardson: hacker without portfolio</li> - <li>Claudia Schmeing: documentation</li> - <li>Sam Sgro: technical support via the <a href="mail.html#lists">mailing - lists</a></li> -</ul> - -<p>The project is funded by civil libertarians who consider our goals -worthwhile. Most of the team are paid for this work.</p> - -<p>People outside this core team have made substantial contributions. See</p> -<ul> - <li>our <a href="../CREDITS">CREDITS</a> file</li> - <li>the <a href="web.html#patch">patches and add-ons</a> section of our web - references file</li> - <li>lists below of user-written <a href="#howto">HowTos</a> and <a - href="#applied">other papers</a></li> -</ul> - -<p>Additional contributions are welcome. See the <a -href="faq.html#contrib.faq">FAQ</a> for details.</p> - -<h2><a name="products">Products containing FreeS/WAN</a></h2> - -<p>Unfortunately the <a href="politics.html#exlaw">export laws</a> of some -countries restrict the distribution of strong cryptography. FreeS/WAN is -therefore not in the standard Linux kernel and not in all CD or web -distributions.</p> - -<p>FreeS/WAN is, however, quite widely used. Products we know of that use it -are listed below. We would appreciate hearing, via the <a -href="mail.html#lists">mailing lists</a>, of any we don't know of.</p> - -<h3><a name="distwith">Full Linux distributions</a></h3> - -<p>FreeS/WAN is included in various general-purpose Linux distributions, -mostly from countries (shown in brackets) with more sensible laws:</p> -<ul> - <li><a href="http://www.suse.com/">SuSE Linux</a> (Germany)</li> - <li><a href="http://www.conectiva.com">Conectiva</a> (Brazil)</li> - <li><a href="http://www.linux-mandrake.com/en/">Mandrake</a> (France)</li> - <li><a href="http://www.debian.org">Debian</a></li> - <li>the <a href="http://www.pld.org.pl/">Polish(ed) Linux Distribution</a> - (Poland)</li> - <li><a>Best Linux</a> (Finland)</li> -</ul> - -<p>For distributions which do not include FreeS/WAN and are not Redhat (which -we develop and test on), there is additional information in our <a -href="compat.html#otherdist">compatibility</a> section.</p> - -<p>The server edition of <a href="http://www.corel.com">Corel</a> Linux -(Canada) also had FreeS/WAN, but Corel have dropped that product line.</p> - -<h3><a name="kernel_dist">Linux kernel distributions</a></h3> - -<ul> -<li><a href="http://sourceforge.net/projects/wolk/">Working Overloaded Linux Kernel (WOLK)</a></li> -</ul> - - -<h3><a name="office_dist">Office server distributions</a></h3> - -<p>FreeS/WAN is also included in several distributions aimed at the market -for turnkey business servers:</p> -<ul> - <li><a href="http://www.e-smith.com/">e-Smith</a> (Canada), which has - recently been acquired and become the Network Server Solutions group of - <a href="http://www.mitel.com/">Mitel Networks</a> (Canada)</li> - <li><a href="http://www.clarkconnect.org/">ClarkConnect</a> from Point Clark Networks (Canada)</li> - <li><a href="http://www.trustix.net/">Trustix Secure Linux</a> (Norway)</li> - -</ul> - -<h3><a name="fw_dist">Firewall distributions</a></h3> - -<p>Several distributions intended for firewall and router applications -include FreeS/WAN:</p> -<ul> - <li>The <a href="http://www.linuxrouter.org/">Linux Router Project</a> - produces a Linux distribution that will boot from a single floppy. The <a - href="http://leaf.sourceforge.net">LEAF</a> firewall project provides - several different LRP-based firewall packages. At least one of them, - Charles Steinkuehler's Dachstein, includes FreeS/WAN with X.509 - patches.</li> - <li>there are several distributions bootable directly from CD-ROM, usable - on a machine without hard disk. - <ul> - <li>Dachstein (see above) can be used this way</li> - <li><a href="http://www.gibraltar.at/">Gibraltar</a> is based on Debian - GNU/Linux.</li> - <li>at time of writing, <a href="www.xiloo.com">Xiloo</a> is available - only in Chinese. An English version is expected.</li> - </ul> - </li> - <li><a href="http://www.astaro.com/products/index.html">Astaro Security - Linux</a> includes FreeS/WAN. It has some web-based tools for managing - the firewall that include FreeS/WAN configuration management.</li> - <li><a href="http://www.linuxwall.de">Linuxwall</a></li> - <li><a href="http://www.smoothwall.org/">Smoothwall</a></li> - <li><a href="http://www.devil-linux.org/">Devil Linux</a></li> - <li>Coyote Linux has a <a - href="http://embedded.coyotelinux.com/wolverine/index.php">Wolverine</a> - firewall/VPN server</li> -</ul> - -<p>There are also several sets of scripts available for managing a firewall -which is also acting as a FreeS/WAN IPsec gateway. See this <a -href="firewall.html#rules.pub">list</a>.</p> - -<h3><a name="turnkey">Firewall and VPN products</a></h3> - -<p>Several vendors use FreeS/WAN as the IPsec component of a turnkey firewall -or VPN product.</p> - -<p>Software-only products:</p> -<ul> - <li><a href="http://www.linuxmagic.com/vpn/index.html">Linux Magic</a> - offer a VPN/Firewall product using FreeS/WAN</li> - <li>The Software Group's <a - href="http://www.wanware.com/sentinet/">Sentinet</a> product uses - FreeS/WAN</li> - <li><a href="http://www.merilus.com">Merilus</a> use FreeS/WAN in their - Gateway Guardian firewall product</li> -</ul> - -<p>Products that include the hardware:</p> -<ul> - <li>The <a href="http://www.lasat.com">LASAT SafePipe[tm]</a> series. is an - IPsec box based on an embedded MIPS running Linux with FreeS/WAN and a - web-config front end. This company also host our freeswan.org web - site.</li> - <li>Merilus <a - href="http://www.merilus.com/products/fc/index.shtml">Firecard</a> is a - Linux firewall on a PCI card.</li> - <li><a href="http://www.kyzo.com/">Kyzo</a> have a "pizza box" product line - with various types of server, all running from flash. One of them is an - IPsec/PPTP VPN server</li> - <li><a href="http://www.pfn.com">PFN</a> use FreeS/WAN in some of their - products</li> -</ul> - -<p><a href="www.rebel.com">Rebel.com</a>, makers of the Netwinder Linux -machines (ARM or Crusoe based), had a product that used FreeS/WAN. The -company is in receivership so the future of the Netwinder is at best unclear. -<a href="web.html#patch">PKIX patches</a> for FreeS/WAN developed at Rebel -are listed in our web links document.</p> - - -<h2><a name="docs">Information sources</a></h2> - -<h3><a name="docformats">This HowTo, in multiple formats</a></h3> - -<p>FreeS/WAN documentation up to version 1.5 was available only in HTML. Now -we ship two formats:</p> -<ul> - <li>as HTML, one file for each doc section plus a global <a - href="toc.html">Table of Contents</a></li> - <li><a href="HowTo.html">one big HTML file</a> for easy searching</li> -</ul> - -<p>and provide a Makefile to generate other formats if required:</p> -<ul> - <li><a href="HowTo.pdf">PDF</a></li> - <li><a href="HowTo.ps">Postscript</a></li> - <li><a href="HowTo.txt">ASCII text</a></li> -</ul> - -<p>The Makefile assumes the htmldoc tool is available. You can download it -from <a href="http://www.easysw.com">Easy Software</a>.</p> - -<p>All formats should be available at the following websites:</p> -<ul> - <li><a href="http://www.freeswan.org/doc.html">FreeS/WAN project</a></li> - <li><a href="http://www.linuxdoc.org">Linux Documentation Project</a></li> -</ul> - -<p>The distribution tarball has only the two HTML formats.</p> - -<p><strong>Note:</strong> If you need the latest doc version, for example to -see if anyone has managed to set up interoperation between FreeS/WAN and -whatever, then you should download the current snapshot. What is on the web -is documentation as of the last release. Snapshots have all changes I've -checked in to date.</p> - -<h3><a name="rtfm">RTFM (please Read The Fine Manuals)</a></h3> - -<p>As with most things on any Unix-like system, most parts of Linux FreeS/WAN -are documented in online manual pages. We provide a list of <a -href="/mnt/floppy/manpages.html">FreeS/WAN man pages</a>, with links to HTML -versions of them.</p> - -<p>The man pages describing configuration files are:</p> -<ul> - <li><a href="/mnt/floppy/manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a></li> - <li><a - href="/mnt/floppy/manpage.d/ipsec.secrets.5.html">ipsec.secrets(5)</a></li> -</ul> - -<p>Man pages for common commands include:</p> -<ul> - <li><a href="/mnt/floppy/manpage.d/ipsec.8.html">ipsec(8)</a></li> - <li><a - href="/mnt/floppy/manpage.d/ipsec_pluto.8.html">ipsec_pluto(8)</a></li> - <li><a - href="/mnt/floppy/manpage.d/ipsec_newhostkey.8.html">ipsec_newhostkey(8)</a></li> - <li><a href="/mnt/floppy/manpage.d/ipsec_auto.8.html">ipsec_auto(8)</a></li> -</ul> - -<p>You can read these either in HTML using the links above or with the -<var>man(1)</var> command.</p> - -<p>In the event of disagreement between this HTML documentation and the man -pages, the man pages are more likely correct since they are written by the -implementers. Please report any such inconsistency on the <a -href="mail.html#lists">mailing list</a>.</p> - -<h3><a name="text">Other documents in the distribution</a></h3> - -<p>Text files in the main distribution directory are README, INSTALL, -CREDITS, CHANGES, BUGS and COPYING.</p> - -<p>The Libdes encryption library we use has its own documentation. You can -find it in the library directory..</p> - -<h3><a name="assumptions">Background material</a></h3> - -<p>Throughout this documentation, I write as if the reader had at least a -general familiarity with Linux, with Internet Protocol networking, and with -the basic ideas of system and network security. Of course that will certainly -not be true for all readers, and quite likely not even for a majority.</p> - -<p>However, I must limit amount of detail on these topics in the main text. -For one thing, I don't understand all the details of those topics myself. -Even if I did, trying to explain everything here would produce extremely long -and almost completely unreadable documentation.</p> - -<p>If one or more of those areas is unknown territory for you, there are -plenty of other resources you could look at:</p> -<dl> - <dt>Linux</dt> - <dd>the <a href="http://www.linuxdoc.org">Linux Documentation Project</a> - or a local <a href="http://www.linux.org/groups/">Linux User Group</a> - and these <a href="web.html#linux.link">links</a></dd> - <dt>IP networks</dt> - <dd>Rusty Russell's <a - href="http://netfilter.samba.org/unreliable-guides/networking-concepts-HOWTO/index.html">Networking - Concepts HowTo</a> and these <a - href="web.html#IP.background">links</a></dd> - <dt>Security</dt> - <dd>Schneier's book <a href="biblio.html#secrets">Secrets and Lies</a> - and these <a href="web.html#crypto.link">links</a></dd> -</dl> - -<p>Also, I do make an effort to provide some background material in these -documents. All the basic ideas behind IPsec and FreeS/WAN are explained here. -Explanations that do not fit in the main text, or that not everyone will -need, are often in the <a href="glossary.html#ourgloss">glossary</a>, which is -the largest single file in this document set. There is also a <a -href="background.html#background">background</a> file containing various -explanations too long to fit in glossary definitions. All files are heavily -sprinkled with links to each other and to the glossary. <strong>If some passage -makes no sense to you, try the links</strong>.</p> - -<p>For other reference material, see the <a -href="biblio.html#biblio">bibliography</a> and our collection of <a -href="web.html#weblinks">web links</a>.</p> - -<p>Of course, no doubt I get this (and other things) wrong sometimes. -Feedback via the <a href="mail.html#lists">mailing lists</a> is welcome.</p> - -<h3><a name="archives">Archives of the project mailing list</a></h3> - -<p>Until quite recently, there was only one FreeS/WAN mailing list, and -archives of it were:</p> -<ul> - <li><a href="http://www.sandelman.ottawa.on.ca/linux-ipsec">Canada</a></li> - <li><a href="http://www.nexial.com">Holland</a></li> -</ul> -The two archives use completely different search engines. You might want to -try both. - -<p>More recently we have expanded to five lists, each with its own -archive.</p> - -<p><a href="mail.html#lists">More information</a> on mailing lists.</p> - -<h3><a name="howto">User-written HowTo information</a></h3> - -<p>Various user-written HowTo documents are available. The ones covering -FreeS/WAN-to-FreeS/WAN connections are:</p> -<ul> - <li>Jean-Francois Nadeau's <a href="http://jixen.tripod.com/">practical - configurations</a> document</li> - <li>Jens Zerbst's HowTo on <a href="http://dynipsec.tripod.com/">Using - FreeS/WAN with dynamic IP addresses</a>.</li> - <li>an entry in Kurt Seifried's <a - href="http://www.securityportal.com/lskb/kben00000013.html">Linux - Security Knowledge Base</a>.</li> - <li>a section of David Ranch's <a - href="http://www.ecst.csuchico.edu/~dranch/LINUX/index-linux.html#trinityos">Trinity - OS Guide</a></li> - <li>a section in David Bander's book <a href="biblio.html#bander">Linux - Security Toolkit</a></li> -</ul> - -<p>User-wriiten HowTo material may be <strong>especially helpful if you need -to interoperate with another IPsec implementation</strong>. We have neither -the equipment nor the manpower to test such configurations. Users seem to be -doing an admirable job of filling the gaps.</p> -<ul> - <li>list of user-written <a href="interop.html#otherpub">interoperation - HowTos</a> in our interop document</li> -</ul> - -<p>Check what version of FreeS/WAN user-written documents cover. The software -is under active development and the current version may be significantly -different from what an older document describes.</p> - -<h3><a name="applied">Papers on FreeS/WAN</a></h3> - -<p>Two design documents show team thinking on new developments:</p> -<ul> - <li><a href="opportunism.spec">Opportunistic Encryption</a> by technical - lead Henry Spencer and Pluto programmer Hugh Redelemeier</li> - <li>discussion of <a - href="http://www.sandelman.ottawa.on.ca/SSW/freeswan/klips2req/">KLIPS - redesign</a></li> -</ul> - -<p>Both documents are works in progress and are frequently revised. For the -latest version, see the <a href="mail.html#lists">design mailing list</a>. Comments -should go to that list.</p> - -<p>There is now an <a -href="http://www.ietf.org/internet-drafts/draft-richardson-ipsec-opportunistic-06.txt">Internet -Draft on Opportunistic Encryption</a> by Michael Richardson, Hugh Redelmeier -and Henry Spencer. This is a first step toward getting the protocol -standardised so there can be multiple implementations of it. Discussion of it -takes place on the <a -href="http://www.ietf.org/html.charters/ipsec-charter.html">IETF IPsec -Working Group</a> mailing list.</p> - -<p>A number of papers giving further background on FreeS/WAN, or exploring -its future or its applications, are also available:</p> -<ul> - <li>Both Henry and Richard gave talks on FreeS/WAN at the 2000 <a - href="http://www.linuxsymposium.org">Ottawa Linux Symposium</a>. - <ul> - <li>Richard's <a - href="http://www.conscoop.ottawa.on.ca/rgb/freeswan/ols2k/">slides</a></li> - <li>Henry's paper</li> - <li>MP3 audio of their talks is available from the <a - href="http://www.linuxsymposium.org/">conference page</a></li> - </ul> - </li> - <li><cite>Moat: A Virtual Private Network Appliances and Services - Platform</cite> is a paper about large-scale (a few 100 links) use of - FreeS/WAN in a production application at AT&T Research. It is - available in Postscript or PDF from co-author Steve Bellovin's <a - href="http://www.research.att.com/~smb/papers/index.html">papers list - page</a>.</li> - <li>One of the Moat co-authors, John Denker, has also written - <ul> - <li>a <a - href="http://www.av8n.com/vpn/ipsec+routing.htm">proposal</a> - for how future versions of FreeS/WAN might interact with routing - protocols</li> - <li>a <a - href="http://www.av8n.com/vpn/wishlist.htm">wishlist</a> - of possible new features</li> - </ul> - </li> - <li>Bart Trojanowski's web page has a draft design for <a - href="http://www.jukie.net/~bart/linux-ipsec/">hardware acceleration</a> - of FreeS/WAN</li> -</ul> - -<p>Several of these provoked interesting discussions on the mailing lists, -worth searching for in the <a href="mail.html#archive">archives</a>.</p> - -<p>There are also several papers in languages other than English, see our <a -href="web.html#otherlang">web links</a>.</p> - -<h3><a name="licensing">License and copyright information</a></h3> - -<p>All code and documentation written for this project is distributed under -either the GNU General Public License (<a href="glossary.html#GPL">GPL</a>) -or the GNU Library General Public License. For details see the COPYING file -in the distribution.</p> - -<p>Not all code in the distribution is ours, however. See the CREDITS file -for details. In particular, note that the <a -href="glossary.html#LIBDES">Libdes</a> library and the version of <a -href="glossary.html#MD5">MD5</a> that we use each have their own license.</p> - -<h2><a name="sites">Distribution sites</a></h2> - -<p>FreeS/WAN is available from a number of sites.</p> - -<h3>Primary site</h3> - -<p>Our primary site, is at xs4all (Thanks, folks!) in Holland:</p> -<ul> - <li><a href="http://www.xs4all.nl/~freeswan">HTTP</a></li> - <li><a href="ftp://ftp.xs4all.nl/pub/crypto/freeswan">FTP</a></li> -</ul> - -<h3><a name="mirrors">Mirrors</a></h3> - -<p>There are also mirror sites all over the world:</p> -<ul> - <li><a href="http://www.flora.org/freeswan">Eastern Canada</a> (limited - resouces)</li> - <li><a href="ftp://ludwig.doculink.com/pub/freeswan/">Eastern Canada</a> - (has older versions too)</li> - <li><a href="ftp://ntsc.notBSD.org/pub/crypto/freeswan/">Eastern Canada</a> - (has older versions too)</li> - <li><a href="ftp://ftp.kame.net/pub/freeswan/">Japan</a></li> - <li><a href="ftp://ftp.futuredynamics.com/freecrypto/FreeSWAN/">Hong - Kong</a></li> - <li><a href="ftp://ipsec.dk/pub/freeswan/">Denmark</a></li> - <li><a href="ftp://ftp.net.lut.ac.uk/freeswan">the UK</a></li> - <li><a href="http://storm.alert.sk/comp/mirrors/freeswan/">Slovak - Republic</a></li> - <li><a - href="http://the.wiretapped.net/security/vpn-tunnelling/freeswan/">Australia</a></li> - <li><a href="http://freeswan.technolust.cx/">technolust</a></li> - <li><a href="http://freeswan.devguide.de/">Germany</a></li> - <li>Ivan Moore's <a href="http://snowcrash.tdyc.com/freeswan/">site</a></li> - <li>the <a href="http://www.cryptoarchive.net/">Crypto Archive</a> on the - <a href="http://www.securityportal.com/">Security Portal</a> site</li> - <li><a href="http://www.wiretapped.net/">Wiretapped.net</a> in - Australia</li> -</ul> - -<p>Thanks to those folks as well.</p> - -<h3><a name="munitions">The "munitions" archive of Linux crypto -software</a></h3> - -<p>There is also an archive of Linux crypto software called "munitions", with -its own mirrors in a number of countries. It includes FreeS/WAN, though not -always the latest version. Some of its sites are:</p> -<ul> - <li><a href="http://munitions.vipul.net/">Germany</a></li> - <li><a href="http://munitions.iglu.cjb.net/">Italy</a></li> - <li><a href="http://munitions2.xs4all.nl/">Netherlands</a></li> -</ul> - -<p>Any of those will have a list of other "munitions" mirrors. There is also -a CD available.</p> - -<h2>Links to other sections</h2> - -<p>For more detailed background information, see:</p> -<ul> - <li><a href="politics.html#politics">history and politics</a> of - cryptography</li> - <li><a href="ipsec.html#ipsec.detail">IPsec protocols</a></li> -</ul> - -<p>To begin working with FreeS/WAN, go to our <a -href="quickstart.html#quick.guide">quickstart</a> guide.</p> -</body> -</html> diff --git a/doc/src/ipsec.html b/doc/src/ipsec.html deleted file mode 100644 index 4647eaf66..000000000 --- a/doc/src/ipsec.html +++ /dev/null @@ -1,1206 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>IPsec protocols</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, protocol, ESP, AH, IKE"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: ipsec.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1><a name="ipsec.detail">The IPsec protocols</a></h1> - -<p>This section provides information on the IPsec protocols which FreeS/WAN -implements. For more detail, see the <a href="rfc.html">RFCs</a>.</p> - -<p>The basic idea of IPsec is to provide security functions, <a -href="glossary.html#authentication">authentication</a> and <a -href="glossary.html#encryption">encryption</a>, at the IP (Internet Protocol) -level. This requires a higher-level protocol (IKE) to set things up for the -IP-level services (ESP and AH).</p> - -<h2>Protocols and phases</h2> - -<p>Three protocols are used in an IPsec implementation:</p> -<dl> - <dt>ESP, Encapsulating Security Payload</dt> - <dd>Encrypts and/or authenticates data</dd> - <dt>AH, Authentication Header</dt> - <dd>Provides a packet authentication service</dd> - <dt>IKE, Internet Key Exchange</dt> - <dd>Negotiates connection parameters, including keys, for the other - two</dd> -</dl> - -<p>The term "IPsec" (also written as IPSEC) is slightly ambiguous. In some -contexts, it includes all three of the above but in other contexts it refers -only to AH and ESP.</p> - -<p>There is more detail below, but a quick summary of how the whole thing -works is:</p> -<dl> - <dt>Phase one IKE (main mode exchange)</dt> - <dd>sets up a keying channel (ISAKMP SA) between the two gateways</dd> - <dt>Phase two IKE (quick mode exchange)</dt> - <dd>sets up data channels (IPsec SAs)</dd> - <dt>IPsec proper</dt> - <dd>exchanges data using AH or ESP</dd> -</dl> - -<p>Both phases of IKE are repeated periodically to automate re-keying.</p> - -<h2><a name="others">Applying IPsec</a></h2> - -<p>Authentication and encryption functions for network data can, of course, -be provided at other levels. Many security protocols work at levels above -IP.</p> -<ul> - <li><a href="glossary.html#PGP">PGP</a> encrypts and authenticates mail - messages</li> - <li><a href="glossary.html#SSH">SSH</a> authenticates remote logins and - then encrypts the session</li> - <li><a href="glossary.html#SSL">SSL</a> or <a - href="glossary.html#TLS">TLS</a> provides security at the sockets layer, - e.g. for secure web browsing</li> -</ul> - -<p>and so on. Other techniques work at levels below IP. For example, data on -a communications circuit or an entire network can be encrypted by specialised -hardware. This is common practice in high-security applications.</p> - -<h3><a name="advantages">Advantages of IPsec</a></h3> - -<p>There are, however, advantages to doing it at the IP level instead of, or -as well as, at other levels.</p> - -<p>IPsec is the <strong>most general way to provide these services for the -Internet</strong>.</p> -<ul> - <li>Higher-level services protect a <em>single protocol</em>; for example - PGP protects mail.</li> - <li>Lower level services protect a <em>single medium</em>; for example a - pair of encryption boxes on the ends of a line make wiretaps on that line - useless unless the attacker is capable of breaking the encryption.</li> -</ul> - -<p>IPsec, however, can protect <em>any protocol</em> running above IP and -<em>any medium</em> which IP runs over. More to the point, it can protect a -mixture of application protocols running over a complex combination of media. -This is the normal situation for Internet communication; IPsec is the only -general solution.</p> - -<p>IPsec can also provide some security services "in the background", with -<strong>no visible impact on users</strong>. To use <a -href="glossary.html#PGP">PGP</a> encryption and signatures on mail, for -example, the user must at least:</p> -<ul> - <li>remember his or her passphrase,</li> - <li>keep it secure</li> - <li>follow procedures to validate correspondents' keys</li> -</ul> - -<p>These systems can be designed so that the burden on users is not onerous, -but any system will place some requirements on users. No such system can hope -to be secure if users are sloppy about meeting those requirements. The author -has seen username and password stuck on terminals with post-it notes in an -allegedly secure environment, for example.</p> - -<h3><a name="limitations">Limitations of IPsec</a></h3> - -<p>IPsec is designed to secure IP links between machines. It does that well, -but it is important to remember that there are many things it does not do. -Some of the important limitations are:</p> -<dl> - <dt><a name="depends">IPsec cannot be secure if your system isn't</a></dt> - <dd>System security on IPsec gateway machines is an essential requirement - if IPsec is to function as designed. No system can be trusted if the - underlying machine has been subverted. See books on Unix security such - as <a href="biblio.html#practical">Garfinkel and Spafford</a> or our - web references for <a href="web.html#linsec">Linux security</a> or more - general <a href="web.html#compsec">computer security</a>. - <p>Of course, there is another side to this. IPsec can be a powerful - tool for improving system and network security. For example, requiring - packet authentication makes various spoofing attacks harder and IPsec - tunnels can be extremely useful for secure remote administration of - various things.</p> - </dd> - <dt><a name="not-end-to-end">IPsec is not end-to-end</a></dt> - <dd>IPsec cannot provide the same end-to-end security as systems working - at higher levels. IPsec encrypts an IP connection between two machines, - which is quite a different thing than encrypting messages between users - or between applications. - <p>For example, if you need mail encrypted from the sender's desktop to - the recipient's desktop and decryptable only by the recipient, use <a - href="glossary.html#PGP">PGP</a> or another such system. IPsec can - encrypt any or all of the links involved -- between the two mail - servers, or between either server and its clients. It could even be - used to secure a direct IP link from the sender's desktop machine to - the recipient's, cutting out any sort of network snoop. What it cannot - ensure is end-to-end user-to-user security. If only IPsec is used to - secure mail, then anyone with appropriate privileges on any machine - where that mail is stored (at either end or on any store-and-forward - servers in the path) can read it.</p> - <p>In another common setup, IPsec encrypts packets at a security - gateway machine as they leave the sender's site and decrypts them on - arrival at the gateway to the recipient's site. This does provide a - useful security service -- only encrypted data is passed over the - Internet -- but it does not even come close to providing an end-to-end - service. In particular, anyone with appropriate privileges on either - site's LAN can intercept the message in unencrypted form.</p> - </dd> - <dt><a name="notpanacea">IPsec cannot do everything</a></dt> - <dd>IPsec also cannot provide all the functions of systems working at - higher levels of the protocol stack. If you need a document - electronically signed by a particular person, then you need his or her - <a href="glossary.html#signature">digital signature</a> and a <a - href="glossary.html#public">public key cryptosystem</a> to verify it - with. - <p>Note, however, that IPsec authentication of the underlying - communication can make various attacks on higher-level protocols more - difficult. In particular, authentication prevents <a - href="glossary.html#middle">man-in-the-middle attacks</a>.</p> - </dd> - <dt><a name="no_user">IPsec authenticates machines, not users</a></dt> - <dd>IPsec uses strong authentication mechanisms to control which messages - go to which machines, but it does not have the concept of user ID, - which is vital to many other security mechansims and policies. This - means some care must be taken in fitting the various security - mechansims on a network together. For example, if you need to control - which users access your database server, you need some non-IPsec - mechansim for that. IPsec can control which machines connect to the - server, and can ensure that data transfer to those machines is done - securely, but that is all. Either the machines themselves must control - user access or there must be some form of user authentication to the - database, independent of IPsec.</dd> - <dt><a name="DoS">IPsec does not stop denial of service attacks</a></dt> - <dd><a href="glossary.html#DOS">Denial of service</a> attacks aim at - causing a system to crash, overload, or become confused so that - legitimate users cannot get whatever services the system is supposed to - provide. These are quite different from attacks in which the attacker - seeks either to use the service himself or to subvert the service into - delivering incorrect results. - <p>IPsec shifts the ground for DoS attacks; the attacks possible - against systems using IPsec are different than those that might be used - against other systems. It does not, however, eliminate the possibility - of such attacks.</p> - </dd> - <dt><a name="traffic">IPsec does not stop traffic analysis</a></dt> - <dd><a href="glossary.html#traffic">Traffic analysis</a> is the attempt - to derive intelligence from messages without regard for their contents. - In the case of IPsec, it would mean analysis based on things visible in - the unencrypted headers of encrypted packets -- source and destination - gateway addresses, packet size, et cetera. Given the resources to - acquire such data and some skill in analysing it (both of which any - national intelligence agency should have), this can be a very powerful - technique. - <p>IPsec is not designed to defend against this. Partial defenses are - certainly possible, and some are <a href="#traffic.resist">described - below</a>, but it is not clear that any complete defense can be - provided.</p> - </dd> -</dl> - -<h3><a name="uses">IPsec is a general mechanism for securing IP</a></h3> - -<p>While IPsec does not provide all functions of a mail encryption package, -it can encrypt your mail. In particular, it can ensure that all mail passing -between a pair or a group of sites is encrypted. An attacker looking only at -external traffic, without access to anything on or behind the IPsec gateway, -cannot read your mail. He or she is stymied by IPsec just as he or she would -be by <a href="glossary.html#PGP">PGP</a>.</p> - -<p>The advantage is that IPsec can provide the same protection for <strong> -anything transmitted over IP</strong>. In a corporate network example, PGP -lets the branch offices exchange secure mail with head office. SSL and SSH -allow them to securely view web pages, connect as terminals to machines, and -so on. IPsec can support all those applications, plus database queries, file -sharing (NFS or Windows), other protocols encapsulated in IP (Netware, -Appletalk, ...), phone-over-IP, video-over-IP, ... anything-over-IP. The only -limitation is that IP Multicast is not yet supported, though there are -Internet Draft documents for that.</p> - -<p>IPsec creates <strong>secure tunnels through untrusted networks</strong>. -Sites connected by these tunnels form VPNs, <a -href="glossary.html#VPN">Virtual Private Networks</a>.</p> - -<p>IPsec gateways can be installed wherever they are required.</p> -<ul> - <li>One organisation might choose to install IPsec only on firewalls - between their LANs and the Internet. This would allow them to create a - VPN linking several offices. It would provide protection against anyone - outside their sites.</li> - <li>Another might install IPsec on departmental servers so everything on - the corporate backbone net was encrypted. This would protect messages on - that net from everyone except the sending and receiving department.</li> - <li>Another might be less concerned with information secrecy and more with - controlling access to certain resources. They might use IPsec packet - authentication as part of an access control mechanism, with or without - also using the IPsec encryption service.</li> - <li>It is even possible (assuming adequate processing power and an IPsec - implementation in each node) to make every machine its own IPsec gateway - so that everything on a LAN is encrypted. This protects information from - everyone outside the sending and receiving machine.</li> - <li>These techniques can be combined in various ways. One might, for - example, require authentication everywhere on a network while using - encryption only for a few links.</li> -</ul> - -<p>Which of these, or of the many other possible variants, to use is up to -you. <strong>IPsec provides mechanisms; you provide the policy</strong>.</p> - -<p><strong>No end user action is required</strong> for IPsec security to be -used; they don't even have to know about it. The site administrators, of -course, do have to know about it and to put some effort into making it work. -Poor administration can compromise IPsec as badly as the post-it notes -mentioned above. It seems reasonable, though, for organisations to hope their -system administrators are generally both more security-conscious than end -users and more able to follow computer security procedures. If not, at least -there are fewer of them to educate or replace.</p> - -<p>IPsec can be, and often should be, used with along with security protocols -at other levels. If two sites communicate with each other via the Internet, -then IPsec is the obvious way to protect that communication. If two others -have a direct link between them, either link encryption or IPsec would make -sense. Choose one or use both. Whatever you use at and below the IP level, -use other things as required above that level. Whatever you use above the IP -level, consider what can be done with IPsec to make attacks on the higher -levels harder. For example, <a href="glossary.html#middle">man-in-the-middle -attacks</a> on various protocols become difficult if authentication at packet -level is in use on the potential victims' communication channel.</p> - -<h3><a name="authonly">Using authentication without encryption</a></h3> - -<p>Where appropriate, IPsec can provide authentication without encryption. -One might do this, for example:</p> -<ul> - <li>where the data is public but one wants to be sure of getting the right - data, for example on some web sites</li> - <li>where encryption is judged unnecessary, for example on some company or - department LANs</li> - <li>where strong encryption is provided at link level, below IP</li> - <li>where strong encryption is provided in other protocols, above IP<br> - Note that IPsec authentication may make some attacks on those protocols - harder.</li> -</ul> - -<p>Authentication has lower overheads than encryption.</p> - -<p>The protocols provide four ways to build such connections, using either an -AH-only connection or ESP using null encryption, and in either manually or -automatically keyed mode. FreeS/WAN supports only one of these, manually -keyed AH-only connections, and <strong>we do not recommend using -that</strong>. Our reasons are discussed under <a -href="#traffic.resist">Resisting traffic analysis</a> a few sections further -along.</p> - -<h3><a name="encnoauth">Encryption without authentication is -dangerous</a></h3> - -<p>Originally, the IPsec encryption protocol <a -href="glossary.html#ESP">ESP</a> didn't do integrity checking. It only did -encryption. Steve Bellovin found many ways to attack ESP used without -authentication. See his paper <a -href="http://www.research.att.com/~smb/papers/badesp.ps">Problem areas for -the IP Security Protocols</a>. To make a secure connection, you had to add an -<a href="glossary.html#AH">AH</a> Authentication Header as well as ESP. -Rather than incur the overhead of several layers (and rather than provide an -ESP layer that didn't actually protect the traffic), the IPsec working group -built integrity and replay checking directly into ESP.</p> - -<p>Today, typical usage is one of:</p> -<ul> - <li>ESP for encryption and authentication</li> - <li>AH for authentication alone</li> -</ul> - -<p>Other variants are allowed by the standard, but not much used:</p> -<dl> - <dt>ESP encryption without authentication</dt> - <dd><strong>Bellovin has demonstrated fatal flaws in this. Do not - use.</strong></dd> - <dt>ESP encryption with AH authentication</dt> - <dd>This has higher overheads than using the authentication in ESP, and - no obvious benefit in most cases. The exception might be a network - where AH authentication was widely or universally used. If you're going - to do AH to conform with network policy, why authenticate again in the - ESP layer?</dd> - <dt>Authenticate twice, with AH and with ESP</dt> - <dd>Why? Of course, some folk consider "belt and suspenders" the sensible - approach to security. If you're among them, you might use both - protocols here. You might also use both to satisfy different parts of a - security policy. For example, an organisation might require AH - authentication everywhere but two users within the organisation might - use ESP as well.</dd> - <dt>ESP authentication without encryption</dt> - <dd>The standard allows this, calling it "null encryption". FreeS/WAN - does not support it. We recommend that you use AH instead if - authentication is all you require. AH authenticates parts of the IP - header, which ESP-null does not do.</dd> -</dl> - -<p>Some of these variants cannot be used with FreeS/WAN because we do not -support ESP-null and do not support automatic keying of AH-only -connections.</p> - -<p>There are fairly frequent suggestions that AH be dropped entirely from the -IPsec specifications since ESP and null encryption can handle that situation. -It is not clear whether this will occur. My guess is that it is unlikely.</p> - -<h3><a name="multilayer">Multiple layers of IPsec processing are -possible</a></h3> - -<p>The above describes combinations possible on a single IPsec connection. In -a complex network you may have several layers of IPsec in play, with any of -the above combinations at each layer.</p> - -<p>For example, a connection from a desktop machine to a database server -might require AH authentication. Working with other host, network and -database security measures, AH might be just the thing for access control. -You might decide not to use ESP encryption on such packets, since it uses -resources and might complicate network debugging. Within the site where the -server is, then, only AH would be used on those packets.</p> - -<p>Users at another office, however, might have their whole connection (AH -headers and all) passing over an IPsec tunnel connecting their office to the -one with the database server. Such a tunnel should use ESP encryption and -authentication. You need authentication in this layer because without -authentication the encryption is vulnerable and the gateway cannot verify the -AH authentication. The AH is between client and database server; the gateways -aren't party to it.</p> - -<p>In this situation, some packets would get multiple layers of IPsec applied -to them, AH on an end-to-end client-to-server basis and ESP from one office's -security gateway to the other.</p> - -<h3><a name="traffic.resist">Resisting traffic analysis</a></h3> - -<p><a href="glossary.html#traffic">Traffic analysis</a> is the attempt to -derive useful intelligence from encrypted traffic without breaking the -encryption.</p> - -<p>Is your CEO exchanging email with a venture capital firm? With bankruptcy -trustees? With an executive recruiting agency? With the holder of some -important patents? If an eavesdropper learns about any of those, then he has -interesting intelligence on your company, whether or not he can read the -messages themselves.</p> - -<p>Even just knowing that there is network traffic between two sites may tell -an analyst something useful, especially when combined with whatever other -information he or she may have. For example, if you know Company A is having -cashflow problems and Company B is looking for aquisitions, then knowing that -packets are passing between the two is interesting. It is more interesting if -you can tell it is email, and perhaps yet more if you know the sender and -recipient.</p> - -<p>Except in the simplest cases, traffic analysis is hard to do well. It -requires both considerable resources and considerable analytic skill. -However, intelligence agencies of various nations have been doing it for -centuries and many of them are likely quite good at it by now. Various -commercial organisations, especially those working on "targeted marketing" -may also be quite good at analysing certain types of traffic.</p> - -<p>In general, defending against traffic analysis is also difficult. -Inventing a really good defense could get you a PhD and some interesting job -offers.</p> - -<p>IPsec is not designed to stop traffic analysis and we know of no plausible -method of extending it to do so. That said, there are ways to make traffic -analysis harder. This section describes them.</p> - -<h4><a name="extra">Using "unnecessary" encryption</a></h4> - -<p>One might choose to use encryption even where it appears unnecessary in -order to make analysis more difficult. Consider two offices which pass a -small volume of business data between them using IPsec and also transfer -large volumes of Usenet news. At first glance, it would seem silly to encrypt -the newsfeed, except possibly for any newsgroups that are internal to the -company. Why encrypt data that is all publicly available from many sites?</p> - -<p>However, if we encrypt a lot of news and send it down the same connection -as our business data, we make <a href="glossary.html#traffic">traffic -analysis</a> much harder. A snoop cannot now make inferences based on -patterns in the volume, direction, sizes, sender, destination, or timing of -our business messages. Those messages are hidden in a mass of news messages -encapsulated in the same way.</p> - -<p>If we're going to do this we need to ensure that keys change often enough -to remain secure even with high volumes and with the adversary able to get -plaintext of much of the data. We also need to look at other attacks this -might open up. For example, can the adversary use a chosen plaintext attack, -deliberately posting news articles which, when we receive and encrypt them, -will help break our encryption? Or can he block our business data -transmission by flooding us with silly news articles? Or ...</p> - -<p>Also, note that this does not provide complete protection against traffic -analysis. A clever adversary might still deduce useful intelligence from -statistical analysis (perhaps comparing the input newsfeed to encrypted -output, or comparing the streams we send to different branch offices), or by -looking for small packets which might indicate establishment of TCP -connections, or ...</p> - -<p>As a general rule, though, to improve resistance to traffic analysis, you -should <strong>encrypt as much traffic as possible, not just as much as seems -necessary.</strong></p> - -<h4><a name="multi-encrypt">Using multiple encryption</a></h4> - -<p>This also applies to using multiple layers of encryption. If you have an -IPsec tunnel between two branch offices, it might appear silly to send <a -href="glossary.html#PGP">PGP</a>-encrypted email through that tunnel. -However, if you suspect someone is snooping your traffic, then it does make -sense:</p> -<ul> - <li>it protects the mail headers; they cannot even see who is mailing - who</li> - <li>it protects against user bungles or software malfunctions that - accidentally send messages in the clear</li> - <li>it makes any attack on the mail encryption much harder; they have to - break IPsec or break into your network before they can start on the mail - encryption</li> -</ul> - -<p>Similar arguments apply for <a href="glossary.html#SSL">SSL</a>-encrypted -web traffic or <a href="glossary.html#SSH">SSH</a>-encrypted remote login -sessions, even for end-to-end IPsec tunnels between systems in the two -offices.</p> - -<h4><a name="fewer">Using fewer tunnels</a></h4> - -<p>It may also help to use fewer tunnels. For example, if all you actually -need encrypted is connections between:</p> -<ul> - <li>mail servers at branch and head offices</li> - <li>a few branch office users and the head office database server</li> -</ul> - -<p>You might build one tunnel per mail server and one per remote database -user, restricting traffic to those applications. This gives the traffic -analyst some information, however. He or she can distinguish the tunnels by -looking at information in the ESP header and, given that distinction and the -patterns of tunnel usage, might be able to figure out something useful. -Perhaps not, but why take the risk?</p> - -<p>We suggest instead that you build one tunnel per branch office, encrypting -everything passing from head office to branches. This has a number of -advantages:</p> -<ul> - <li>it is easier to build and administer</li> - <li>it resists traffic analysis somewhat better</li> - <li>it provides security for whatever you forgot. For example, if some user - at a remote office browses proprietary company data on some head office - web page (that the security people may not even know about!), then that - data is encrypted before it reaches the Internet.</li> -</ul> - -<p>Of course you might also want to add additional tunnels. For example, if -some of the database data is confidential and should not be exposed even -within the company, then you need protection from the user's desktop to the -database server. We suggest you do that in whatever way seems appropriate -- -IPsec, SSH or SSL might fit -- but, whatever you choose, pass it between -locations via a gateway-to-gateway IPsec tunnel to provide some resistance to -traffic analysis.</p> - -<h2><a name="primitives">Cryptographic components</a></h2> - -<p>IPsec combines a number of cryptographic techniques, all of them -well-known and well-analyzed. The overall design approach was conservative; -no new or poorly-understood components were included.</p> - -<p>This section gives a brief overview of each technique. It is intended only -as an introduction. There is more information, and links to related topics, -in our <a href="glossary.html">glossary</a>. See also our <a -href="biblio.html">bibliography</a> and cryptography <a -href="web.html#crypto.link">web links</a>.</p> - -<h3><a name="block.cipher">Block ciphers</a></h3> - -<p>The <a href="glossary.html#encryption">encryption</a> in the <a -href="glossary.html#ESP">ESP</a> encapsulation protocol is done with a <a -href="glossary.html#block">block cipher</a>.</p> - -<p>We do not implement <a href="glossary.html#DES">single DES</a>. It is <a -href="politics.html#desnotsecure">insecure</a>. Our default, and currently -only, block cipher is <a href="glossary.html#3DES">triple DES</a>.</p> - -<p>The <a href="glossary.html#rijndael">Rijndael</a> block cipher has won the -<a href="glossary.html#AES">AES</a> competition to choose a relacement for -DES. It will almost certainly be added to FreeS/WAN and to other IPsec -implementations. <a href="web.html#patch">Patches</a> are already -available.</p> - -<h3><a name="hash.ipsec">Hash functions</a></h3> - -<h4><a name="hmac.ipsec">The HMAC construct</a></h4> - -<p>IPsec packet authentication is done with the <a -href="glossary.html#HMAC">HMAC</a> construct. This is not just a hash of the -packet data, but a more complex operation which uses both a hashing algorithm -and a key. It therefore does more than a simple hash would. A simple hash -would only tell you that the packet data was not changed in transit, or that -whoever changed it also regenerated the hash. An HMAC also tells you that the -sender knew the HMAC key.</p> - -<p>For IPsec HMAC, the output of the hash algorithm is truncated to 96 bits. -This saves some space in the packets. More important, it prevents an attacker -from seeing all the hash output bits and perhaps creating some sort of attack -based on that knowledge.</p> - -<h4>Choice of hash algorithm</h4> - -<p>The IPsec RFCs require two hash algorithms -- <a -href="glossary.html#MD5">MD5</a> and <a href="glossary.html#SHA">SHA-1</a> -- -both of which FreeS/WAN implements.</p> - -<p>Various other algorithms -- such as RIPEMD and Tiger -- are listed in the -RFCs as optional. None of these are in the FreeS/WAN distribution, or are -likely to be added, although user <a href="web.html#patch">patches</a> exist -for several of them.</p> - -<p>Additional hash algorithms -- <a href="glossary.html#SHA-256">SHA-256, -SHA-384 and SHA-512</a> -- may be required to give hash strength matching the -strength of <a href="glossary.html#AES">AES</a>. These are likely to be added -to FreeS/WAN along with AES.</p> - -<h3><a name="DH.keying">Diffie-Hellman key agreement</a></h3> - -<p>The <a href="glossary.html#DH">Diffie-Hellman</a> key agreement protocol -allows two parties (A and B or <a href="glossary.html#alicebob">Alice and -Bob</a>) to agree on a key in such a way that an eavesdropper who intercepts -the entire conversation cannot learn the key.</p> - -<p>The protocol is based on the <a href="glossary.html#dlog">discrete -logarithm</a> problem and is therefore thought to be secure. Mathematicians -have been working on that problem for years and seem no closer to a solution, -though there is no proof that an efficient solution is impossible.</p> - -<h3><a name="RSA.auth">RSA authentication</a></h3> - -<p>The <a href="glossary.html#RSA">RSA</a> algorithm (named for its inventors --- Rivest, Shamir and Adleman) is a very widely used <a -href="glossary.html#">public key</a> cryptographic technique. It is used in -IPsec as one method of authenticating gateways for Diffie-Hellman key -negotiation.</p> - -<h2><a name="structure">Structure of IPsec</a></h2> - -<p>There are three protocols used in an IPsec implementation:</p> -<dl> - <dt>ESP, Encapsulating Security Payload</dt> - <dd>Encrypts and/or authenticates data</dd> - <dt>AH, Authentication Header</dt> - <dd>Provides a packet authentication service</dd> - <dt>IKE, Internet Key Exchange</dt> - <dd>Negotiates connection parameters, including keys, for the other - two</dd> -</dl> - -<p>The term "IPsec" is slightly ambiguous. In some contexts, it includes all -three of the above but in other contexts it refers only to AH and ESP.</p> - -<h3><a name="IKE.ipsec">IKE (Internet Key Exchange)</a></h3> - -<p>The IKE protocol sets up IPsec (ESP or AH) connections after negotiating -appropriate parameters (algorithms to be used, keys, connection lifetimes) -for them. This is done by exchanging packets on UDP port 500 between the two -gateways.</p> - -<p>IKE (RFC 2409) was the outcome of a long, complex process in which quite a -number of protocols were proposed and debated. Oversimplifying mildly, IKE -combines:</p> -<dl> - <dt>ISAKMP (RFC 2408)</dt> - <dd>The <strong>I</strong>nternet <strong>S</strong>ecurity - <strong>A</strong>ssociation and <strong>K</strong>ey - <strong>M</strong>anagement <strong>P</strong>rotocol manages - negotiation of connections and defines <a - href="glossary.html#SA">SA</a>s (Security Associations) as a means of - describing connection properties.</dd> - <dt>IPsec DOI for ISAKMP (RFC 2407)</dt> - <dd>A <strong>D</strong>omain <strong>O</strong>f - <strong>I</strong>nterpretation fills in the details necessary to turn - the rather abstract ISAKMP protocol into a more tightly specified - protocol, so it becomes applicable in a particular domain.</dd> - <dt>Oakley key determination protocol (RFC 2412)</dt> - <dd>Oakley creates keys using the <a - href="glossary.html#DH">Diffie-Hellman</a> key agreement protocol.</dd> -</dl> - -<p>For all the details, you would need to read the four <a -href="rfc.html">RFCs</a> just mentioned (over 200 pages) and a number of -others. We give a summary below, but it is far from complete.</p> - -<h4><a name="phases">Phases of IKE</a></h4> - -<p>IKE negotiations have two phases.</p> -<dl> - <dt>Phase one</dt> - <dd>The two gateways negotiate and set up a two-way ISAKMP SA which they - can then use to handle phase two negotiations. One such SA between a - pair of gateways can handle negotiations for multiple tunnels.</dd> - <dt>Phase two</dt> - <dd>Using the ISAKMP SA, the gateways negotiate IPsec (ESP and/or AH) SAs - as required. IPsec SAs are unidirectional (a different key is used in - each direction) and are always negotiated in pairs to handle two-way - traffic. There may be more than one pair defined between two - gateways.</dd> -</dl> - -<p>Both of these phases use the UDP protocol and port 500 for their -negotiations.</p> - -<p>After both IKE phases are complete, you have IPsec SAs to carry your -encrypted data. These use the ESP or AH protocols. These protocols do not -have ports. Ports apply only to UDP or TCP.</p> - -<p>The IKE protocol is designed to be extremely flexible. Among the things -that can be negotiated (separately for each SA) are:</p> -<ul> - <li>SA lifetime before rekeying</li> - <li>encryption algorithm used. We currently support only <a - href="glossary.html#3DES">triple DES</a>. Single DES is <a - href="politics.html#desnotsecure">insecure</a>. The RFCs say you MUST do - DES, SHOULD do 3DES and MAY do various others. We do not do any of the - others.</li> - <li>authentication algorithms. We support <a - href="glossary.html#MD5">MD5</a> and <a href="glossary.html#SHA">SHA</a>. - These are the two the RFCs require.</li> - <li>choice of group for <a href="glossary.html#DH">Diffie-Hellman</a> key - agreement. We currently support Groups 2 and 5 (which are defined modulo - primes of various lengths) and do not support Group 1 (defined modulo a - shorter prime, and therefore cryptographically weak) or groups 3 and 4 - (defined using elliptic curves). The RFCs require only Group 1.</li> -</ul> - -<p>The protocol also allows implementations to add their own encryption -algorithms, authentication algorithms or Diffie-Hellman groups. We do not -support any such extensions, but there are some <a -href="web.html#patch">patches</a> that do.</p> - -<p>There are a number of complications:</p> -<ul> - <li>The gateways must be able to authenticate each other's identities - before they can create a secure connection. This host authentication is - part of phase one negotiations, and is a required prerequisite for packet - authentication used later. Host authentication can be done in a variety - of ways. Those supported by FreeS/WAN are discussed in our <a - href="adv_config.html#auto-auth">advanced configuration</a> document.</li> - <li>Phase one can be done in two ways. - <ul> - <li>Main Mode is required by the RFCs and supported in FreeS/WAN. It - uses a 6-packet exzchange.</li> - <li>Aggressive Mode is somewhat faster (only 3 packets) but reveals - more to an eavesdropper. This is optional in the RFCs, not currently - supported by FreeS/WAN, and not likely to be.</li> - </ul> - </li> - <li>A new group exchange may take place after phase one but before phase - two, defining an additional group for use in the <a - href="glossary.html#DH">Diffie-Hellman</a> key agreement part of phase - two. FreeS/WAN does not currently support this.</li> - <li>Phase two always uses Quick Mode, but there are two variants of that: - <ul> - <li>One variant provides <a href="glossary.html#PFS">Perfect Forward - Secrecy (PFS)</a>. An attacker that obtains your long-term host - authentication key does not immediately get any of your short-term - packet encryption of packet authentication keys. He must conduct - another successful attack each time you rekey to get the short-term - keys. Having some short-term keys does not help him learn others. In - particular, breaking your system today does not let him read messages - he archived yestarday, assuming you've changed short-term keys in the - meanwhile. We enable PFS as the default.</li> - <li>The other variant disables PFS and is therefore slightly faster. We - do not recommend this since it is less secure, but FreeS/WAN does - support it. You can enable it with a <var>pfs=no</var> statement in - <a href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a>.</li> - <li>The protocol provides no way to negotiate which variant will be - used. If one gateway is set for PFS and the other is not, the - negotiation fails. This has proved a fairly common source of - interoperation problems.</li> - </ul> - </li> - <li>Several types of notification message may be sent by either side during - either phase, or later. FreeS/WAN does not currently support these, but - they are a likely addition in future releases.</li> - <li>There is a commit flag which may optionally be set on some messages. - The <a href="http://www.lounge.org/ike_doi_errata.html">errata</a> page - for the RFCs includes two changes related to this, one to clarify the - description of its use and one to block a <a - href="glossary.html#DOS">denial of service</a> attack which uses it. We - currently do not implement this feature.</li> -</ul> - -<p>These complications can of course lead to problems, particularly when two -different implementations attempt to interoperate. For example, we have seen -problems such as:</p> -<ul> - <li>Some implementations (often products crippled by <a - href="politics.html#exlaw">export laws</a>) have the insecure DES - algorithm as their only supported encryption method. Other parts of our - documentation discuss the <a - href="politics.html#desnotsecure">reasons we do not implement single - DES</a>, and <a href="interop.html#noDES">how to cope with crippled - products</a>.</li> - <li>Windows 2000 IPsec tries to negotiate using Aggressive Mode, which we - don't support. Later on, it uses the commit bit, which we also don't - support.</li> - <li>Various implementations disable PFS by default, and therefore will not - talk to FreeS/WAN until you either turn on PFS on their end or turn it - off in FreeS/WAN with a <var>pfs=no</var> entry in the connection - description.</li> - <li>FreeS/WAN's interaction with PGPnet is complicated by their use of - notification messages we do not yet support.</li> -</ul> - -<p>Despite this, we do interoperate successfully with many implementations, -including both Windows 2000 and PGPnet. Details are in our <a -href="interop.html">interoperability</a> document.</p> - -<h4><a name="sequence">Sequence of messages in IKE</a></h4> - -<p>Each phase (see <a href="#phases">previous section</a>)of IKE involves a -series of messages. In Pluto error messages, these are abbreviated using:</p> -<dl> - <dt>M</dt> - <dd><strong>M</strong>ain mode, settting up the keying channel (ISAKMP - SA)</dd> - <dt>Q</dt> - <dd><strong>Q</strong>uick mode, setting up the data channel (IPsec - SA)</dd> - <dt>I</dt> - <dd><strong>I</strong>nitiator, the machine that starts the - negotiation</dd> - <dt>R</dt> - <dd><strong>R</strong>esponder</dd> -</dl> - -<p>For example, the six messages of a main mode negotiation, in sequence, are -labelled:</p> -<pre> MI1 ----------> - <---------- MR1 - MI2 ----------> - <---------- MR2 - MI3 ----------> - <---------- MR3</pre> - -<h4><a name="struct.exchange">Structure of IKE messages</a></h4> - -<p>Here is our Pluto developer explaining some of this on the mailing -list:</p> -<pre>When one IKE system (for example, Pluto) is negotiating with another -to create an SA, the Initiator proposes a bunch of choices and the -Responder replies with one that it has selected. - -The structure of the choices is fairly complicated. An SA payload -contains a list of lists of "Proposals". The outer list is a set of -choices: the selection must be from one element of this list. - -Each of these elements is a list of Proposals. A selection must be -made from each of the elements of the inner list. In other words, -*all* of them apply (that is how, for example, both AH and ESP can -apply at once). - -Within each of these Proposals is a list of Transforms. For each -Proposal selected, one Transform must be selected (in other words, -each Proposal provides a choice of Transforms). - -Each Transform is made up of a list of Attributes describing, well, -attributes. Such as lifetime of the SA. Such as algorithm to be -used. All the Attributes apply to a Transform. - -You will have noticed a pattern here: layers alternate between being -disjunctions ("or") and conjunctions ("and"). - -For Phase 1 / Main Mode (negotiating an ISAKMP SA), this structure is -cut back. There must be exactly one Proposal. So this degenerates to -a list of Transforms, one of which must be chosen.</pre> - -<h3><a name="services">IPsec Services, AH and ESP</a></h3> - -<p>IPsec offers two services, <a -href="glossary.html#authentication">authentication</a> and <a -href="glossary.html#encryption">encryption</a>. These can be used separately -but are often used together.</p> -<dl> - <dt>Authentication</dt> - <dd>Packet-level authentication allows you to be confident that a packet - came from a particular machine and that its contents were not altered - en route to you. No attempt is made to conceal or protect the contents, - only to assure their integrity. Packet authentication can be provided - separately using an <a href="glossary.html#AH">Authentication - Header</a>, described just below, or it can be included as part of the - <a href="glossary.html#ESP">ESP</a> (Encapsulated Security Payload) - service, described in the following section. That service offers - encryption as well as authentication. In either case, the <a - href="glossary.html#HMAC">HMAC</a> construct is used as the - authentication mechanism. - <p>There is a separate authentication operation at the IKE level, in - which each gateway authenticates the other. This can be done in a - variety of ways.</p> - </dd> - <dt>Encryption</dt> - <dd>Encryption allows you to conceal the contents of a message from - eavesdroppers. - <p>In IPsec this is done using a <a href="glossary.html#block">block - cipher</a> (normally <a href="glossary.html#3DES">Triple DES</a> for - Linux). In the most used setup, keys are automatically negotiated, and - periodically re-negotiated, using the <a - href="glossary.html#IKE">IKE</a> (Internet Key Exchange) protocol. In - Linux FreeS/WAN this is handled by the Pluto Daemon.</p> - <p>The IPsec protocol offering encryption is <a - href="glossary.html#ESP">ESP</a>, Encapsulated Security Payload. It can - also include a packet authentication service.</p> - </dd> -</dl> - -<p>Note that <strong>encryption should always be used with some packet -authentication service</strong>. Unauthenticated encryption is vulnerable to -<a href="glossary.html#middle">man-in-the-middle attacks</a>. Also note that -encryption does not prevent <a href="glossary.html#traffic">traffic -analysis</a>.</p> - -<h3><a name="AH.ipsec">The Authentication Header (AH)</a></h3> - -<p>Packet authentication can be provided separately from encryption by adding -an authentication header (AH) after the IP header but before the other -headers on the packet. This is the subject of this section. Details are in -RFC 2402.</p> - -<p>Each of the several headers on a packet header contains a "next protocol" -field telling the system what header to look for next. IP headers generally -have either TCP or UDP in this field. When IPsec authentication is used, the -packet IP header has AH in this field, saying that an Authentication Header -comes next. The AH header then has the next header type -- usually TCP, UDP -or encapsulated IP.</p> - -<p>IPsec packet authentication can be added in transport mode, as a -modification of standard IP transport. This is shown in this diagram from the -RFC:</p> -<pre> BEFORE APPLYING AH - ---------------------------- - IPv4 |orig IP hdr | | | - |(any options)| TCP | Data | - ---------------------------- - - AFTER APPLYING AH - --------------------------------- - IPv4 |orig IP hdr | | | | - |(any options)| AH | TCP | Data | - --------------------------------- - || - except for mutable fields</pre> - -<p>Athentication can also be used in tunnel mode, encapsulating the -underlying IP packet beneath AH and an additional IP header.</p> -<pre> || -IPv4 | new IP hdr* | | orig IP hdr* | | | - |(any options)| AH | (any options) |TCP | Data | - ------------------------------------------------ - || - | in the new IP hdr |</pre> - -<p>This would normally be used in a gateway-to-gateway tunnel. The receiving -gateway then strips the outer IP header and the AH header and forwards the -inner IP packet.</p> - -<p>The mutable fields referred to are things like the time-to-live field in -the IP header. These cannot be included in authentication calculations -because they change as the packet travels.</p> - -<h4><a name="keyed">Keyed MD5 and Keyed SHA</a></h4> - -<p>The actual authentication data in the header is typically 96 bits and -depends both on a secret shared between sender and receiver and on every byte -of the data being authenticated. The technique used is <a -href="glossary.html#HMAC">HMAC</a>, defined in RFC 2104.</p> - -<p>The algorithms involved are the <a href="glossary.html#MD5">MD5</a> -Message Digest Algorithm or <a href="glossary.html#SHA">SHA</a>, the Secure -Hash Algorithm. For details on their use in this application, see RFCs 2403 -and 2404 respectively.</p> - -<p>For descriptions of the algorithms themselves, see RFC 1321 for MD5 and <a -href="glossary.html#FIPS">FIPS</a> (Federal Information Processing Standard) -number 186 from <a href="glossary.html#NIST">NIST</a>, the US National -Institute of Standards and Technology for SHA. <a -href="biblio.html#schneier"><cite>Applied Cryptography</cite></a> covers both -in some detail, MD5 starting on page 436 and SHA on 442.</p> - -<p>These algorithms are intended to make it nearly impossible for anyone to -alter the authenticated data in transit. The sender calculates a digest or -hash value from that data and includes the result in the authentication -header. The recipient does the same calculation and compares results. For -unchanged data, the results will be identical. The hash algorithms are -designed to make it extremely difficult to change the data in any way and -still get the correct hash.</p> - -<p>Since the shared secret key is also used in both calculations, an -interceptor cannot simply alter the authenticated data and change the hash -value to match. Without the key, he or she (or even the dreaded They) cannot -produce a usable hash.</p> - -<h4><a name="sequence">Sequence numbers</a></h4> - -<p>The authentication header includes a sequence number field which the -sender is required to increment for each packet. The receiver can ignore it -or use it to check that packets are indeed arriving in the expected -sequence.</p> - -<p>This provides partial protection against <a -href="glossary.html#replay">replay attacks</a> in which an attacker resends -intercepted packets in an effort to confuse or subvert the receiver. Complete -protection is not possible since it is necessary to handle legitmate packets -which are lost, duplicated, or delivered out of order, but use of sequence -numbers makes the attack much more difficult.</p> - -<p>The RFCs require that sequence numbers never cycle, that a new key always -be negotiated before the sequence number reaches 2^32-1. This protects both -against replays attacks using packets from a previous cyclce and against <a -href="glossary.html#birthday">birthday attacks</a> on the the packet -authentication algorithm.</p> - -<p>In Linux FreeS/WAN, the sequence number is ignored for manually keyed -connections and checked for automatically keyed ones. In manual mode, there -is no way to negotiate a new key, or to recover from a sequence number -problem, so we don't use sequence numbers.</p> - -<h3><a name="ESP.ipsec">Encapsulated Security Payload (ESP)</a></h3> - -<p>The ESP protocol is defined in RFC 2406. It provides one or both of -encryption and packet authentication. It may be used with or without AH -packet authentication.</p> - -<p>Note that <strong>some form of packet authentication should -<em>always</em> be used whenever data is encrypted</strong>. Without -authentication, the encryption is vulnerable to active attacks which may -allow an enemy to break the encryption. ESP should <strong>always</strong> -either include its own authentication or be used with AH authentication.</p> - -<p>The RFCs require support for only two mandatory encryption algorithms -- -<a href="glossary.html#DES">DES</a>, and null encryption -- and for two -authentication methods -- keyed MD5 and keyed SHA. Implementers may choose to -support additional algorithms in either category.</p> - -<p>The authentication algorithms are the same ones used in the IPsec <a -href="#AH">authentication header</a>.</p> - -<p>We do not implement single DES since <a -href="politics.html#desnotsecure">DES is insecure</a>. Instead we provide <a -href="glossary.html#3DES">triple DES or 3DES</a>. This is currently the only -encryption algorithm supported.</p> - -<p>We do not implement null encryption since it is obviously insecure.</p> - -<h2><a name="modes">IPsec modes</a></h2> - -<p>IPsec can connect in two modes. Transport mode is a host-to-host -connection involving only two machines. In tunnel mode, the IPsec machines -act as gateways and trafiic for any number of client machines may be -carried.</p> - -<h3><a name="tunnel.ipsec">Tunnel mode</a></h3> - -<p>Security gateways are required to support tunnel mode connections. In this -mode the gateways provide tunnels for use by client machines behind the -gateways. The client machines need not do any IPsec processing; all they have -to do is route things to gateways.</p> - -<h3><a name="transport.ipsec">Transport mode</a></h3> - -<p>Host machines (as opposed to security gateways) with IPsec implementations -must also support transport mode. In this mode, the host does its own IPsec -processing and routes some packets via IPsec.</p> - -<h2><a name="parts">FreeS/WAN parts</a></h2> - -<h3><a name="KLIPS.ipsec">KLIPS: Kernel IPsec Support</a></h3> - -<p>KLIPS is <strong>K</strong>erne<strong>L</strong> <strong>IP</strong>SEC -<strong>S</strong>upport, the modifications necessary to support IPsec within -the Linux kernel. KILPS does all the actual IPsec packet-handling, -including</p> -<ul> - <li>encryption</li> - <li>packet authentication calculations</li> - <li>creation of ESP and AH headers for outgoing packets</li> - <li>interpretation of those headers on incoming packets</li> -</ul> - -<p>KLIPS also checks all non-IPsec packets to ensure they are not bypassing -IPsec security policies.</p> - -<h3><a name="Pluto.ipsec">The Pluto daemon</a></h3> - -<p><a href="manpage.d/ipsec_pluto.8.html">Pluto(8)</a> is a daemon which -implements the IKE protocol. It</p> -<ul> - <li>handles all the Phase one ISAKMP SAs</li> - <li>performs host authentication and negotiates with other gateways</li> - <li>creates IPsec SAs and passes the data required to run them to KLIPS</li> - <li>adjust routing and firewall setup to meet IPsec requirements. See our - <a href="firewall.html">IPsec and firewalling</a> document for - details.</li> -</ul> - -<p>Pluto is controlled mainly by the <a -href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a> configuration file.</p> - -<h3><a name="command">The ipsec(8) command</a></h3> - -<p>The <a href="manpage.d/ipsec.8.html">ipsec(8)</a> command is a front end -shellscript that allows control over IPsec activity.</p> - -<h3><a name="ipsec.conf">Linux FreeS/WAN configuration file</a></h3> - -<p>The configuration file for Linux FreeS/WAN is</p> -<pre> /etc/ipsec.conf</pre> - -<p>For details see the <a -href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a> manual page .</p> - -<h2><a name="key">Key management</a></h2> - -<p>There are several ways IPsec can manage keys. Not all are implemented in -Linux FreeS/WAN.</p> - -<h3><a name="current">Currently Implemented Methods</a></h3> - -<h4><a name="manual">Manual keying</a></h4> - -<p>IPsec allows keys to be manually set. In Linux FreeS/WAN, such keys are -stored with the connection definitions in /etc/ipsec.conf.</p> - -<p><a href="glossary.html#manual">Manual keying</a> is useful for debugging -since it allows you to test the <a href="glossary.html#KLIPS">KLIPS</a> -kernel IPsec code without the <a href="glossary.html#Pluto">Pluto</a> daemon -doing key negotiation.</p> - -<p>In general, however, automatic keying is preferred because it is more -secure.</p> - -<h4><a name="auto">Automatic keying</a></h4> - -<p>In automatic keying, the <a href="glossary.html#Pluto">Pluto</a> daemon -negotiates keys using the <a href="glossary.html#IKE">IKE</a> Internet Key -Exchange protocol. Connections are automatically re-keyed periodically.</p> - -<p>This is considerably more secure than manual keying. In either case an -attacker who acquires a key can read every message encrypted with that key, -but automatic keys can be changed every few hours or even every few minutes -without breaking the connection or requiring intervention by the system -administrators. Manual keys can only be changed manually; you need to shut -down the connection and have the two admins make changes. Moreover, they have -to communicate the new keys securely, perhaps with <a -href="glossary.html#PGP">PGP</a> or <a href="glossary.html#SSH">SSH</a>. This -may be possible in some cases, but as a general solution it is expensive, -bothersome and unreliable. Far better to let <a -href="glossary.html#Pluto">Pluto</a> handle these chores; no doubt the -administrators have enough to do.</p> - -<p>Also, automatic keying is inherently more secure against an attacker who -manages to subvert your gateway system. If manual keying is in use and an -adversary acquires root privilege on your gateway, he reads your keys from -/etc/ipsec.conf and then reads all messages encrypted with those keys.</p> - -<p>If automatic keying is used, an adversary with the same privileges can -read /etc/ipsec.secrets, but this does not contain any keys, only the secrets -used to authenticate key exchanges. Having an adversary able to authenticate -your key exchanges need not worry you overmuch. Just having the secrets does -not give him any keys. You are still secure against <a -href="glossary.html#passive">passive</a> attacks. This property of automatic -keying is called <a href="glossary.html#PFS">perfect forward secrecy</a>, -abbreviated PFS.</p> - -<p>Unfortunately, having the secrets does allow an <a -href="glossary.html#active">active attack</a>, specifically a <a -href="glossary.html#middle">man-in-the-middle</a> attack. Losing these -secrets to an attacker may not be quite as disastrous as losing the actual -keys, but it is <em>still a serious security breach</em>. These secrets -should be guarded as carefully as keys.</p> - -<h3><a name="notyet">Methods not yet implemented</a></h3> - -<h4><a name="noauth">Unauthenticated key exchange</a></h4> - -<p>It would be possible to exchange keys without authenticating the players. -This would support <a href="glossary.html#carpediem">opportunistic -encryption</a> -- allowing any two systems to encrypt their communications -without requiring a shared PKI or a previously negotiated secret -- and would -be secure against <a href="glossary.html#passive">passive attacks</a>. It -would, however, be highly vulnerable to active <a -href="glossary.html#middle">man-in-the-middle</a> attacks. RFC 2408 therefore -specifies that all <a href="glossary.html#ISAKMP">ISAKMP</a> key management -interactions <em>must</em> be authenticated.</p> - -<p>There is room for debate here. Should we provide immediate security -against <a href="glossary.html#passive">passive attacks</a> and encourage -widespread use of encryption, at the expense of risking the more difficult <a -href="glossary.html#active">active attacks</a>? Or should we wait until we -can implement a solution that can both be widespread and offer security -against active attacks?</p> - -<p>So far, we have chosen the second course, complying with the RFCs and -waiting for secure DNS (see <a href="glossary.html#DNS">below</a>) so that we -can do <a href="glossary.html#carpediem">opportunistic encryption</a> -right.</p> - -<h4><a name="DNS">Key exchange using DNS</a></h4> - -<p>The IPsec RFCs allow key exchange based on authentication services -provided by <a href="glossary.html#SDNS">Secure DNS</a>. Once Secure DNS -service becomes widely available, we expect to make this the <em>primary key -management method for Linux FreeS/WAN</em>. It is the best way we know of to -support <a href="glossary.html#carpediem">opportunistic encryption</a>, -allowing two systems without a common PKI or previous negotiation to secure -their communication.</p> - -<p>We currently have code to acquire RSA keys from DNS but do not yet have -code to validate Secure DNS signatures.</p> - -<h4><a name="PKI">Key exchange using a PKI</a></h4> - -<p>The IPsec RFCs allow key exchange based on authentication services -provided by a <a href="glossary.html#PKI">PKI</a> or Public Key -Infrastructure. With many vendors selling such products and many large -organisations building these infrastructures, this will clearly be an -important application of IPsec and one Linux FreeS/WAN will eventually -support.</p> - -<p>On the other hand, this is not as high a priority for Linux FreeS/WAN as -solutions based on <a href="glossary.html#SDNS">secure DNS</a>. We do not -expect any PKI to become as universal as DNS.</p> - -<p>Some <a href="web.html#patch">patches</a> to handle authentication with -X.509 certificates, which most PKIs use, are available.</p> - -<h4><a name="photuris">Photuris</a></h4> - -<p><a href="glossary.html#photuris">Photuris</a> is another key management -protocol, an alternative to IKE and ISAKMP, described in RFCs 2522 and 2523 -which are labelled "experimental". Adding Photuris support to Linux FreeS/WAN -might be a good project for a volunteer. The likely starting point would be -the OpenBSD photurisd code.</p> - -<h4><a name="skip">SKIP</a></h4> - -<p><a href="glossary.html#SKIP">SKIP</a> is yet another key management -protocol, developed by Sun. At one point it was fairly widely used, but it -now seems moribund, displaced by IKE. Sun now (as of Solaris 8.0) ship an -IPsec implementation using IKE. We have no plans to implement SKIP. If a user -were to implement it, we would almost certainly not want to add the code to -our distribution.</p> -</body> -</html> diff --git a/doc/src/kernel.html b/doc/src/kernel.html deleted file mode 100644 index a4beab417..000000000 --- a/doc/src/kernel.html +++ /dev/null @@ -1,392 +0,0 @@ -<html> -<head> -<title>Kernel configuration for FreeS/WAN</title> -<meta name="keywords" content="Linux, IPsec, VPN, security, FreeSWAN, kernel"> - -<!-- - -Written by Sandy Harris for the Linux FreeS/WAN project -Freely distributable under the GNU General Public License - -More information at www.freeswan.org -Feedback to users@lists.freeswan.org - -CVS information: -RCS ID: $Id: kernel.html,v 1.1 2004/03/15 20:35:24 as Exp $ -Last changed: $Date: 2004/03/15 20:35:24 $ -Revision number: $Revision: 1.1 $ - -CVS revision numbers do not correspond to FreeS/WAN release numbers. ---> -</head> - -<body> - -<h1><a name="kernelconfig">Kernel configuration for FreeS/WAN</a></h1> - -<p> -This section lists many of the options available when configuring a Linux - kernel, and explains how they should be set on a FreeS/WAN IPsec - gateway.</p> - - <h2><a name="notall">Not everyone needs to worry about kernel configuration</a></h2> - - <p>Note that in many cases you do not need to mess with these.</p> - -<p> -You may have a Linux distribution which comes with FreeS/WAN installed -(see this <a href="intro.html#products">list</a>). - In that case, you need not do a FreeS/WAN installation or a kernel - configuration. Of course, you might still want to configure and rebuild your - kernel to improve performance or security. This can be done with standard - tools described in the <a href="http://www.linuxdoc.org/HOWTO/Kernel-HOWTO.html">Kernel HowTo</a>.</p> - - <p>If you need to install FreeS/WAN, then you do need to configure a kernel. - However, you may choose to do that using the simplest procedure:</p> - <ul> - <li>Configure, build and test a kernel for your system before adding FreeS/WAN. See the <a - href="http://www.linuxdoc.org/HOWTO/Kernel-HOWTO.html">Kernel HowTo</a> for details. <strong>This step cannot be - skipped</strong>. FreeS/WAN needs the results of your configuration.</li> - <li>Then use FreeS/WAN's <var>make oldgo</var> command. This sets - everything FreeS/WAN needs and retains your values everywhere else.</li> - </ul> - -<p> -This document is for those who choose to configure their FreeS/WAN kernel -themselves.</p> - -<h2><a name="assume">Assumptions and notation</a></h2> - -<p> -Help text for most kernel options is included with the kernel files, and -is accessible from within the configuration utilities. We assume -you will refer to that, and to the <a href="http://www.linuxdoc.org/HOWTO/Kernel-HOWTO.html">Kernel HowTo</a>, as -necessary. This document covers only the FreeS/WAN-specific aspects of the -problem.</p> - -<p> -To avoid duplication, this document section does not cover settings for -the additional IPsec-related kernel options which become available after you -have patched your kernel with FreeS/WAN patches. There is help text for -those available from within the configuration utility.</p> - - <p> -We assume a common configuration in which the FreeS/WAN IPsec gateway is -also doing ipchains(8) firewalling for a local network, and possibly -masquerading as well.</p> - -<p> -Some suggestions below are labelled as appropriate for "a true paranoid". -By this we mean they may cause inconvenience and it is not entirely clear - they are necessary, but they appear to be the safest choice. Not using them - might entail some risk. Of course one suggested mantra for security - administrators is: "I know I'm paranoid. I wonder if I'm paranoid - enough."</p> - - <h3><a name="labels">Labels used</a></h3> - -<p> -Six labels are used to indicate how options should be set. We mark the -labels with [square brackets]. For two of these labels, you have no -choice:</p> - <dl> - <dt>[required]</dt> - <dd>essential for FreeS/WAN operation.</dd> - <dt>[incompatible]</dt> - <dd>incompatible with FreeS/WAN.</dd> - </dl> - - <p>those must be set correctly or FreeS/WAN will not work</p> - - <p>FreeS/WAN should work with any settings of the others, though of course - not all combinations have been tested. We do label these in various ways, - but <em>these labels are only suggestions</em>.</p> - <dl> - <dt>[recommended]</dt> - <dd>useful on most FreeS/WAN gateways</dd> - <dt>[disable]</dt> - <dd>an unwelcome complication on a FreeS/WAN gateway.</dd> - <dt>[optional]</dt> - <dd>Your choice. We outline issues you might consider.</dd> - <dt>[anything]</dt> - <dd>This option has no direct effect on FreeS/WAN and related tools, so - you should be able to set it as you please.</dd> - </dl> - -<p> -Of course complexity is an enemy in any effort to build secure systems. -<strong>For maximum security, any feature that can reasonably be turned off -should be</strong>. "If in doubt, leave it out."</p> - - <h2><a name="kernelopt">Kernel options for FreeS/WAN</a></h2> - -<p> -Indentation is based on the nesting shown by 'make menuconfig' with a -2.2.16 kernel for the i386 architecture.</p> -<dl> - <dt><a name="maturity">Code maturity and level options</a></dt> - <dd> - <dl> - <dt><a name="devel">Prompt for development ... - code/drivers</a></dt> - <dd>[optional] If this is <var>no</var>, experimental drivers are - not shown in later menus. - <p>For most FreeS/WAN work, <var>no</var> is the preferred - setting. Using new or untested components is too risky for a - security gateway.</p> - <p>However, for some hardware (such as the author's network - cards) the only drivers available are marked - <var>new/experimental</var>. In such cases, you must enable this - option or your cards will not appear under "network device - support". A true paranoid would leave this option off and - replace the cards.</p> - </dd> - <dt>Processor type and features</dt> - <dd>[anything]</dd> - <dt>Loadable module support</dt> - <dd> - <dl> - <dt>Enable loadable module support</dt> - <dd>[optional] A true paranoid would disable this. An attacker who - has root access to your machine can fairly easily install a - bogus module that does awful things, provided modules are - enabled. A common tool for attackers is a "rootkit", a set - of tools the attacker uses once he or she has become root on your system. - The kit introduces assorted additional compromises so that the attacker - will continue to "own" your system despite most things you might - do to recovery the situation. For Linux, there is a tool called - <a href="http://www.sans.org/newlook/resources/IDFAQ/knark.htm">knark</a> - which is basically a rootkit packaged as a kernel module. - <p>With modules disabled, an attacker cannot install a bogus module. - The only way - he can achieve the same effects is to install a new kernel and - reboot. This is considerably more likely to be noticed. - <p>Many FreeS/WAN gateways run with modules enabled. This - simplifies some administrative tasks and some ipchains features - are available only as modules. Once an enemy has root on your - machine your security is nil, so arguably defenses which come - into play only in that situation are pointless.</p> - <p> - - </dd> - <dt>Set version information ....</dt> - <dd>[optional] This provides a check to prevent loading modules - compiled for a different kernel.</dd> - <dt>Kernel module loader</dt> - <dd>[disable] It gives little benefit on a typical FreeS/WAN gate - and entails some risk.</dd> - </dl> - </dd> - <dt>General setup</dt> - <dd>We list here only the options that matter for FreeS/WAN. - <dl> - <dt>Networking support</dt> - <dd>[required]</dd> - <dt>Sysctl interface</dt> - <dd>[optional] If this option is turned on and the - <var>/proc</var> filesystem installed, then you can control - various system behaviours by writing to files under - <var>/proc/sys</var>. For example: - <pre> echo 1 > /proc/sys/net/ipv4/ipforward</pre> - turns IP forwarding on. - <p>Disabling this option breaks many firewall scripts. A true - paranoid would disable it anyway since it might conceivably be - of use to an attacker.</p> - </dd> - </dl> - </dd> - <dt>Plug and Play support</dt> - <dd>[anything]</dd> - <dt>Block devices</dt> - <dd>[anything]</dd> - <dt>Networking options</dt> - <dd> - <dl> - <dt>Packet socket</dt> - <dd>[optional] This kernel feature supports tools such as - tcpdump(8) which communicate directly with network hardware, - bypassing kernel protocols. This is very much a two-edged sword: - <ul> - <li>such tools can be very useful to the firewall admin, - especially during initial testing</li> - <li>should an evildoer breach your firewall, such tools could - give him or her a great deal of information about the rest - of your network</li> - </ul> - We recommend disabling this option on production gateways.</dd> - <dt><a name="netlink">Kernel/User netlink socket</a></dt> - <dd>[optional] Required if you want to use <a href="#adv">advanced - router</a> features.</dd> - <dt>Routing messages</dt> - <dd>[optional]</dd> - <dt>Netlink device emulation</dt> - <dd>[optional]</dd> - <dt>Network firewalls</dt> - <dd>[recommended] You need this if the IPsec gateway also - functions as a firewall. - <p>Even if the IPsec gateway is not your primary firewall, we - suggest setting this so that you can protect the gateway with at - least basic local packet filters.</p> - </dd> - <dt>Socket filtering</dt> - <dd>[disable] This enables an older filtering interface. We suggest - using ipchains(8) instead. To do that, set the "Network - firewalls" option just above, and not this one.</dd> - <dt>Unix domain sockets</dt> - <dd>[required] These sockets are used for communication between the - <a href="manpage.d/ipsec.8.html">ipsec(8)</a> - commands and the <a href="manpage.d/ipsec_pluto.8.html">ipsec_pluto(8)</a> - daemon.</dd> - <dt>TCP/IP networking</dt> - <dd>[required] - <dl> - <dt>IP: multicasting</dt> - <dd>[anything]</dd> - <dt><a name="adv">IP: advanced router</a></dt> - <dd>[optional] This gives you policy routing, which some - people have used to good advantage in their scripts for - FreeS/WAN gateway management. It is not used in our - distributed scripts, so not required unless you want it - for custom scripts. It requires the <a - href="#netlink">netlink</a> interface between kernel code - and the iproute2(8) command.</dd> - <dt>IP: kernel level autoconfiguration</dt> - <dd>[disable] It gives little benefit on a typical FreeS/WAN - gate and entails some risk.</dd> - <dt>IP: firewall packet netlink device</dt> - <dd>[disable]</dd> - <dt>IP: transparent proxy support</dt> - <dd>[optional] This is required in some firewall configurations, - but should be disabled unless you have a definite need for it. - </dd> - <dt>IP: masquerading</dt> - <dd>[optional] Required if you want to use - <a href="glossary.html#non-routable">non-routable</a> private - IP addresses for your local network.</dd> - <dt>IP: Optimize as router not host</dt> - <dd>[recommended]</dd> - <dt>IP: tunneling</dt> - <dd>[required]</dd> - <dt>IP: GRE tunnels over IP</dt> - <dd>[anything]</dd> - <dt>IP: aliasing support</dt> - <dd>[anything]</dd> - <dt>IP: ARP daemon support (EXPERIMENTAL)</dt> - <dd>Not required on most systems, but might prove useful on - heavily-loaded gateways.</dd> - <dt>IP: TCP syncookie support</dt> - <dd>[recommended] It provides a defense against a <a - href="glossary.html#DOS">denial of - service attack</a> which uses bogus TCP connection - requests to waste resources on the victim machine.</dd> - <dt>IP: Reverse ARP</dt> - <dd></dd> - <dt>IP: large window support</dt> - <dd>[recommended] unless you have less than 16 meg RAM</dd> - </dl> - </dd> - <dt>IPv6</dt> - <dd>[optional] FreeS/WAN does not currently support IPv6, though work on - integrating FreeS/WAN with the Linux IPv6 stack has begun. - <a href="compat.html#ipv6">Details</a>. - <p> - It should be possible to use IPv4 FreeS/WAN on a machine which also - does IPv6. This combination is not yet well tested. We would be quite - interested in hearing results from anyone expermenting with it, via the - <a href="mail.html">mailing list</a>. - <p> - We do not recommend using IPv6 on production FreeS/WAN gateways until - more testing has been done. - </dd> - <dt>Novell IPX</dt> - <dd>[disable]</dd> - <dt>Appletalk</dt> - <dd>[disable] Quite a few Linux installations use IP but also have - some other protocol, such as Appletalk or IPX, for communication - with local desktop machines. In theory it should be possible to - configure IPsec for the IP side of things without interfering - with the second protocol. - <p>We do not recommend this. Keep the software on your gateway - as simple as possible. If you need a Linux-based Appletalk or - IPX server, use a separate machine.</p> - </dd> - </dl> - </dd> - <dt>Telephony support</dt> - <dd>[anything]</dd> - <dt>SCSI support</dt> - <dd>[anything]</dd> - <dt>I2O device support</dt> - <dd>[anything]</dd> - <dt>Network device support</dt> - <dd>[anything] should work, but there are some points to note. - <p>The development team test almost entirely on 10 or 100 megabit - Ethernet and modems. In principle, any device that can do IP should be - just fine for IPsec, but in the real world any device that has not - been well-tested is somewhat risky. By all means try it, but don't bet - your project on it until you have solid test results.</p> - <p>If you disabled experimental drivers in the <a - href="#maturity">Code maturity</a> section above, then those drivers - will not be shown here. Check that option before going off to hunt for - missing drivers.</p> - <p>If you want Linux to automatically find more than one ethernet - interface at boot time, you need to:</p> - <ul> - <li>compile the appropriate driver(s) into your kernel. Modules will - not work for this</li> - <li>add a line such as -<pre> - append="ether=0,0,eth0 ether=0,0,eth1" -</pre> - to your /etc/lilo.conf file. In some cases you may need to specify - parameters such as IRQ or base address. The example uses "0,0" - for these, which tells the system to search. If the search does not - succeed on your hardware, then you should retry with explicit parameters. - See the lilo.conf(5) man page for details.</li> - <li>run lilo(8)</li> - </ul> - Having Linux find the cards this way is not necessary, but is usually more - convenient than loading modules in your boot scripts.</dd> - <dt>Amateur radio support</dt> - <dd>[anything]</dd> - <dt>IrDA (infrared) support</dt> - <dd>[anything]</dd> - <dt>ISDN subsystem</dt> - <dd>[anything]</dd> - <dt>Old CDROM drivers</dt> - <dd>[anything]</dd> - <dt>Character devices</dt> - <dd>The only required character device is: - <dl> - <dt>random(4)</dt> - <dd>[required] This is a source of <a href="glossary.html#random">random</a> - numbers which are required for many cryptographic protocols, - including several used in IPsec. - <p>If you are comfortable with C source code, it is likely a - good idea to go in and adjust the <var>#define</var> lines in - <var>/usr/src/linux/drivers/char/random.c</var> to ensure that - all sources of randomness are enabled. Relying solely on - keyboard and mouse randomness is dubious procedure for a gateway - machine. You could also increase the randomness pool size from - the default 512 bytes (128 32-bit words).</p> - </dd> - </dl> - <dt>Filesystems</dt> - <dd>[anything] should work, but we suggest limiting a gateway - machine to the standard Linux ext2 filesystem in most - cases.</dd> - <dt>Network filesystems</dt> - <dd>[disable] These systems are an unnecessary risk on an IPsec - gateway.</dd> - <dt>Console drivers</dt> - <dd>[anything]</dd> - <dt>Sound</dt> - <dd>[anything] should work, but we suggest enabling sound only if - you plan to use audible alarms for firewall problems.</dd> - <dt>Kernel hacking</dt> - <dd>[disable] This might be enabled on test machines, but should - not be on production gateways.</dd> - </dl> - </dl> -</body> -</html> diff --git a/doc/src/mail.html b/doc/src/mail.html deleted file mode 100644 index e26f025a0..000000000 --- a/doc/src/mail.html +++ /dev/null @@ -1,250 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>FreeS/WAN mailing lists</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, mailing, list"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: mail.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1><a name="lists">Mailing lists and newsgroups</a></h1> - -<h2><a name="list.fs">Mailing lists about FreeS/WAN</a></h2> - -<h3><a name="projlist">The project mailing lists</a></h3> - -<p>The Linux FreeS/WAN project has several email lists for user support, bug -reports and software development discussions.</p> - -<p>We had a single list on clinet.fi for several years (Thanks, folks!), then -one list on freeswan.org, but now we've split into several lists:</p> -<dl> - <dt><a - href="mailto:users-request@lists.freeswan.org?body=subscribe">users</a></dt> - <dd><ul> - <li>The general list for discussing use of the software</li> - <li>The place for seeking <strong>help with problems</strong> (but - please check the <a href="faq.html">FAQ</a> first).</li> - <li>Anyone can post.</li> - </ul> - </dd> - <dt><a - href="mailto:bugs-request@lists.freeswan.org?body=subscribe">bugs</a></dt> - <dd><ul> - <li>For <strong>bug reports</strong>.</li> - <li>If you are not certain what is going on -- could be a bug, a - configuration error, a network problem, ... -- please post to the - users list instead.</li> - <li>Anyone can post.</li> - </ul> - </dd> - <dt><a - href="mailto:design-request@lists.freeswan.org?body=subscribe">design</a></dt> - <dd><ul> - <li><strong>Design discussions</strong>, for people working on - FreeS/WAN development or others with an interest in design and - security issues.</li> - <li>It would be a good idea to read the existing design papers (see - this <a href="intro.html#applied">list</a>) before posting.</li> - <li>Anyone can post.</li> - </ul> - </dd> - <dt><a - href="mailto:announce-request@lists.freeswan.org?body=subscribe">announce</a></dt> - <dd><ul> - <li>A <strong>low-traffic</strong> list.</li> - <li><strong>Announcements</strong> about FreeS/WAN and related - software.</li> - <li>All posts here are also sent to the users list. You need not - subscribe to both.</li> - <li>Only the FreeS/WAN team can post.</li> - <li>If you have something you feel should go on this list, send it to - <var>announce-admin@lists.freeswan.org</var>. Unless it is obvious, - please include a short note explaining why we should post it.</li> - </ul> - </dd> - <dt><a - href="mailto:briefs-request@lists.freeswan.org?body=subscribe">briefs</a></dt> - <dd><ul> - <li>A <strong>low-traffic</strong> list.</li> - <li><strong>Weekly summaries</strong> of activity on the users - list.</li> - <li>All posts here are also sent to the users list. You need not - subscribe to both.</li> - <li>Only the FreeS/WAN team can post.</li> - </ul> - </dd> -</dl> - -<p>To subscribe to any of these, you can:</p> -<ul> - <li>just follow the links above</li> - <li>use our <a href="http://www.freeswan.org/mail.html">web - interface</a></li> - <li>send mail to <var>listname</var>-request@lists.freeswan.org with a - one-line message body "subscribe"</li> -</ul> - -<p>Archives of these lists are available via the <a -href="http://www.freeswan.org/mail.html">web interface</a>.</p> - -<h4><a name="which.list">Which list should I use?</a></h4> - -<p>For most questions, please check the <a href="faq.html">FAQ</a> first, and -if that does not have an answer, ask on the users list. "My configuration -doesn't work." does not belong on the bugs list, and "Can FreeS/WAN do -such-and-such" or "How do I configure it to..." do not belong in design -discussions.</p> - -<p>Cross-posting the same message to two or more of these lists is -discouraged. Quite a few people read more than one list and getting multiple -copies is annoying.</p> - -<h4><a name="policy.list">List policies</a></h4> - -<p><strong>US citizens or residents are asked not to post code to the lists, -not even one-line bug fixes</strong>. The project cannot accept code which -might entangle it in US <a href="politics.html#exlaw">export -restrictions</a>.</p> - -<p>Non-subscribers can post to some of these lists. This is necessary; -someone working on a gateway install who encounters a problem may not have -access to a subscribed account.</p> - -<p>Some spam turns up on these lists from time to time. For discussion of why -we do not attempt to filter it, see the <a href="faq.html#spam">FAQ</a>. -Please do not clutter the lists with complaints about this.</p> - -<h3><a name="archive">Archives of the lists</a></h3> - -<p>Searchable archives of the old single list have existed for some time. At -time of writing, it is not yet clear how they will change for the new -multi-list structure.</p> -<ul> - <li><a href="http://www.sandelman.ottawa.on.ca/linux-ipsec">Canada</a></li> - <li><a href="http://www.nexial.com">Holland</a></li> -</ul> - -<p>Note that these use different search engines. Try both.</p> - -<p>Archives of the new lists are available via the <a -href="http://www.freeswan.org/mail.html">web interface</a>.</p> - -<h2><a name="indexes">Indexes of mailing lists</a></h2> - -<p><a href="http://paml.net/">PAML</a> is the standard reference for -<strong>P</strong>ublicly <strong>A</strong>ccessible -<strong>M</strong>ailing <strong>L</strong>ists. When we last checked, it had -over 7500 lists on an amazing variety of topics. It also has FAQ information -and a search engine.</p> - -<p>There is an index of <a -href="http://oslab.snu.ac.kr/~djshin/linux/mail-list/index.shtml">Linux -mailing lists</a> available.</p> - -<p>A list of <a -href="http://xforce.iss.net/maillists/otherlists.php">computer security -mailing lists</a>, with descriptions.</p> - -<h2><a name="otherlists">Lists for related software and topics</a></h2> - -<p>Most links in this section point to subscription addresses for the various -lists. Send the one-line message "subscribe <var>list_name</var>" to -subscribe to any of them.</p> - -<h3>Products that include FreeS/WAN</h3> - -<p>Our introduction document gives a <a href="intro.html#products">list of -products that include FreeS/WAN</a>. If you have, or are considering, one of -those, check the supplier's web site for information on mailing lists for -their users.</p> - -<h3><a name="linux.lists">Linux mailing lists</a></h3> -<ul> - <li><a - href="mailto:majordomo@vger.kernel.org">linux-admin@vger.kernel.org</a>, - for Linux system administrators</li> - <li><a - href="mailto:netfilter-request@lists.samba.org">netfilter@lists.samba.org</a>, - about Netfilter, which replaces IPchains in kernels 2.3.15 and later</li> - <li><a - href="mailto:security-audit-request@ferret.lmh.ox.ac.uk">security-audit@ferret.lmh.ox.ac.uk</a>, - for people working on security audits of various Linux programs</li> - <li><a - href="mailto:securedistros-request@humbolt.geo.uu.nl">securedistros@humbolt.geo.uu.nl</a>, - for discussion of issues common to all the half dozen projects working on - secure Linux distributions.</li> -</ul> - -<p>Each of the scure distribution projects also has its own web site and -mailing list. Some of the sites are:</p> -<ul> - <li><a href="http://bastille-linux.org/">Bastille Linux</a> scripts to - harden Redhat, e.g. by changing permissions and modifying inialisation - scripts</li> - <li><a href="http://immunix.org/">Immunix</a> take a different approach, - using a modified compiler to build kernel and utilities with better - resistance to various types of overflow and exploit</li> - <li>the <a href="glossary.html#NSA">NSA</a> have contractors working on a - <a href="glossary.html#SElinux">Security Enhanced Linux</a>, primarily - adding stronger access control mechanisms. You can download the current - version (which interestingly is under GPL and not export resrtricted) or - subscribe to the mailing list from the <a - href="http://www.nsa.gov/selinux">project web page</a>.</li> -</ul> - -<h3><a name="ietf">Lists for IETF working groups</a></h3> - -<p>Each <a href="glossary.html#IETF">IETF</a> working group has an associated -mailing list where much of the work takes place.</p> -<ul> - <li><a - href="mailto:majordomo@lists.tislabs.com">ipsec@lists.tislabs.com</a>, - the IPsec <a - href="http://www.ietf.org/html.charters/ipsec-charter.html">working - group</a>. This is where the protocols are discussed, new drafts - announced, and so on. By now, the IPsec working group is winding down - since the work is essentially complete. A <a - href="http://www.sandelman.ottawa.on.ca/ipsec/">list archive</a> is - available.</li> - <li><a href="mailto:ipsec-policy-request@vpnc.org">IPsec policy</a> list, - and its <a href="http://www.vpnc.org/ipsec-policy/">archive</a></li> - <li><a href="mailto:ietf-ipsra-request@vpnc.org">IP secure remote - access</a> list, and its <a - href="http://www.vpnc.org/ietf-ipsra/mail-archive/">archive</a></li> -</ul> - -<h3><a name="other">Other mailing lists</a></h3> -<ul> - <li><a - href="mailto:ipc-announce-request@privacy.org">ipc-announce@privacy.org</a> - a low-traffic list with announcements of developments in privacy, - encryption and online civil rights</li> - <li>a VPN mailing list's <a - href="http://kubarb.phsx.ukans.edu/~tbird/vpn.html">home page</a></li> -</ul> - -<h2><a name="newsgroups">Usenet newsgroups</a></h2> -<ul> - <li>sci.crypt</li> - <li>sci.crypt.research</li> - <li>comp.dcom.vpn</li> - <li>talk.politics.crypto</li> -</ul> -</body> -</html> diff --git a/doc/src/makecheck.html b/doc/src/makecheck.html deleted file mode 100644 index 7fa3a3bcb..000000000 --- a/doc/src/makecheck.html +++ /dev/null @@ -1,684 +0,0 @@ -<html> -<head> -<title>FreeS/WAN "make check" guide</title> -<!-- Changed by: Michael Richardson, 02-Apr-2003 --> -<meta name="keywords" content="Linux, IPsec, VPN, security, FreeSWAN, testing, User-Mode-Linux, UML"> - -<!-- - -Written by Michael Richardson for the Linux FreeS/WAN project -Freely distributable under the GNU General Public License - -More information at www.freeswan.org -Feedback to users@lists.freeswan.org - -$Id: makecheck.html,v 1.1 2004/03/15 20:35:24 as Exp $ - -$Log: makecheck.html,v $ -Revision 1.1 2004/03/15 20:35:24 as -added files from freeswan-2.04-x509-1.5.3 - -Revision 1.25 2003/04/02 20:28:33 mcr - document for NETJIGVERBOSE environment variable. - -Revision 1.24 2003/04/02 02:17:52 mcr - added documentation on "PACKETRATE" - -Revision 1.23 2003/02/27 09:28:24 mcr - added documentation for *_RUN2_SCRIPT. - -Revision 1.22 2003/02/20 20:00:44 mcr - added documentation for ${host}HOST. - -Revision 1.21 2003/02/20 19:56:11 mcr - documented new umlXhost test case. - -Revision 1.20 2002/12/06 02:11:42 mcr - added new test type, module_compile. - -Revision 1.19 2002/12/04 03:47:06 mcr - added documentation of various *TESTDEBUG options in - the testing environment. - -Revision 1.18 2002/10/31 19:01:31 mcr - documentation for RUN_*_SCRIPT. - -Revision 1.17 2002/09/11 19:43:36 mcr - added documentation on format of TESTLIST. - -Revision 1.16 2002/09/11 19:26:48 mcr - renamed umlpluto -> umlplutotest. - -Revision 1.15 2002/07/29 22:27:12 mcr - added kernel_patch_test test type. - -Revision 1.14 2002/06/19 18:24:44 mcr - renamed SCRIPT to INIT_SCRIPT. - -Revision 1.13 2002/06/19 10:06:07 mcr - added nightly.html to the documentation tree. - -Revision 1.12 2002/06/19 09:19:26 mcr - wrote documentation for umlpluto parts of makecheck, - and adjusted scripts for consistency. - -Revision 1.11 2002/06/19 07:26:31 mcr - added FINAL_SCRIPT to be run after sending packets through. - renamed "SCRIPT" to "INIT_SCRIPT" (left compat variable) - -Revision 1.10 2002/06/17 05:40:57 mcr - Added test cases for the "make rpm" machinery. - -Revision 1.9 2002/06/08 17:12:49 mcr - added new libtest test type for use in testing libfreeswan - -Revision 1.8 2002/05/27 00:19:38 mcr - removed reference to single_netjig.png because mkhtml does not - grok it. - -Revision 1.7 2002/05/07 01:31:52 mcr - documented the new "mkinsttest" target type. - -Revision 1.6 2002/05/05 23:10:50 mcr - added documentation of $TEST_TYPE variable. - -Revision 1.5 2002/04/19 22:48:41 mcr - added documentation on NETJIGDEBUG and CONSOLEDIFFDEBUG. - -Revision 1.4 2002/04/01 23:59:46 mcr - added documentation on REF_{PUB,PRIV}_FILTER. - -Revision 1.3 2002/04/01 23:38:46 mcr - redo of updates to makecheck - -Revision 1.2 2002/03/12 21:12:07 mcr - initial stab at documentation on klips testing infrastructure. - - ---> -</head> - -<body> - -<h1><a name="makecheck">How to configure to use "make check"</a></h1> - -<H2>What is "make check"</H2> -<p> -"make check" is a target in the top level makefile. It takes care of -running a number of unit and system tests to confirm that FreeSWAN has -been compiled correctly, and that no new bugs have been introduced. -</p> -<p> -As FreeSWAN contains both kernel and userspace components, doing testing -of FreeSWAN requires that the kernel be simulated. This is typically difficult -to do as a kernel requires that it be run on bare hardware. A technology -has emerged that makes this simpler. This is -<A HREF="http://user-mode-linux.sourceforge.net">User Mode Linux</A>. -</p> - -<p> -User-Mode Linux is a way to build a Linux kernel such that it can run as a process -under another Linux (or in the future other) kernel. Presently, this can only be -done for 2.4 guest kernels. The host kernel can be 2.2 or 2.4. -</p> - -<p> -"make check" expects to be able to build User-Mode Linux kernels with FreeSWAN included. -To do this it needs to have some files downloaded and extracted prior -to running "make check". This is described in the -<A HREF="umltesting.html">UML testing</A> document. -</p> - -<p> -After having run the example in the UML testing document and -successfully brought up the four machine combination, you are ready to -use "make check" -</p> - -<h2>Running "make check"</h2> -<p> -"make check" works by walking the FreeSWAN source tree invoking the -"check" target at each node. At present there are tests defined only -for the <CODE>klips</CODE> directory. These tests will use the UML -infrastructure to test out pieces of the <CODE>klips</CODE> code. -</p> -<p> -The results of the tests can be recorded. If the environment variable -<CODE>$REGRESSRESULTS</CODE> is non-null, then the results of each -test will be recorded. This can be used as part of a nightly -regression testing system, see -<A HREF="nightly.html">Nightly testing</A> for more details. -</p> -<p> -"make check" otherwise prints a minimal amount of output for each -test, and indicates pass/fail status of each test as they are run. -Failed tests do not cause failure of the target in the form of exit -codes. -</p> - -<H1>How to write a "make check" test</H1> - -<h2>Structure of a test</h2> - -<p> -Each test consists of a set of directories under <CODE>testing/</CODE>. -There are directories for <CODE>klips</CODE>, <CODE>pluto</CODE>, <CODE>packaging</CODE> -and <CODE>libraries</CODE>. -Each directory has a list of tests to run is stored in a file called <CODE>TESTLIST</CODE> in that directory. e.g. <CODE>testing/klips/TESTLIST</CODE>. -</P> - -<H2 NAME="TESTLIST">The TESTLIST</H2> -<P> -This isn't actually a shell script. It just looks like one. Some tools other than -/bin/sh process it. Lines that start with # are comments. </P> - -<PRE> -# test-kind directory-containing-test expectation [PR#] -</PRE> - -<P>The first word provides the test type, detailed below. </P> -<P> The second word is the name of the test to run. This the directory -in which the test case is to be found..</P> -<P>The third word may be one of: -<DL> -<DT> blank/good</DT> -<DD>the test is believed to function, report failure</DD> -<DT> bad</DT> -<DD> the test is known to fail, report unexpected success</DD> -<DT> suspended</DT> -<DD> the test should not be run</DD> -</DL> - -<P> -The fourth word may be a number, which is a PR# if the test is -failing. -</P> - -<H2>Test kinds</H2> -The test types are: - -<DL> -<DT>skiptest</DT> -<DD>means run no test.</DD> -<DT>ctltest</DT> -<DD>means run a single system without input/output.</DD> -<DT>klipstest</DT> -<DD>means run a single system with input/output networks</DD> -<DT><A HREF="#umlplutotest">umlplutotest</A></DT> -<DD>means run a pair of systems</DD> -<DT><A HREF="#umlXhost">umlXhost</A></DT> -<DD>run an arbitrary number of systems</DT> -<DT>suntest (TBD)</DT> -<DD>means run a quad of east/west/sunrise/sunset</DD> -<DT>roadtest (TBD)</DT> -<DD>means run a trio of east-sunrise + warrior</DD> -<DT>extrudedtest (TBD)</DT> -<DD>means run a quad of east-sunrise + warriorsouth + park</DD> -<DT>mkinsttest</TD> -<DD>a test of the "make install" machinery.</DD> -<DT>kernel_test_patch</TD> -<DD>a test of the "make kernelpatch" machinery.</DD> -</DL> - -Tests marked (TBD) have yet to be fully defined. -</p> - -<p> -Each test directory has a file in it called <CODE>testparams.sh</CODE>. -This file sets a number of environment variables to define the -parameters of the test. -</p> - -<H2>Common parameters</H2> -<DL> -<DT>TESTNAME</DT> -<DD>the name of the test (repeated for checking purposes)</DD> - -<DT>TEST_TYPE</DT> -<DD>the type of the test (repeat of type type above)</DD> - -<DT>TESTHOST</DT> -<DD>the name of the UML machine to run for the test, typically "east" - or "west"</DD> - -<DT>TEST_PURPOSE</DT> -<DD>The purpose of the test is one of: - -<DL> -<DT>goal</DT> -<DD>The goal purpose is where a test is defined for code that is not yet -finished. The test indicates when the goals have in fact been reached.</DD> -<DT>regress</DT> -<DD>This is a test to determine that a previously existing bug has been repaired. This -test will initially be created to reproduce the bug in isolation, and then the bug will -be fixed.</DD> -<DT>exploit</DT> -<DD>This is a set of packets/programs that causes a vulnerability to be -exposed. It is a specific variation of the regress option.</DD> -</DL> -</DD> - -<DT>TEST_GOAL_ITEM<DT> -<DD>in the case of a goal test, this is a reference to the requirements document</DD> - -<DT>TEST_PROB_REPORT</DT> -<DD>in the case of regression test, this the problem report number from GNATS</DD> - -<DT>TEST_EXPLOIT_URL</DT> -<DD>in the case of an exploit, this is a URL referencing the paper explaining -the origin of the test and the origin of exploit software</DD> - -<DT>REF_CONSOLE_OUTPUT</DT> -<DD>a file in the test directory that contains the sanitized console - output against which to compare the output of the actual test.</DD> -<DT>REF_CONSOLE_FIXUPS</DT> -<DD>a list of scripts (found in <CODE>klips/test/fixups</CODE>) to - apply to sanitize the console output of the machine under test. - These are typically perl, awk or sed scripts that remove things in - the kernel output that change each time the test is run and/or - compiled. -</DD> -<DT>INIT_SCRIPT</DT> -<DD><p>a file of commands that is fed into the virtual machine's console - in single user mode prior to starting the tests. This file will - usually set up any eroute's and SADB entries that are required for - the test. </p> -<p>Lines beginning with # are skipped. Blank lines are - skipped. Otherwise, a shell prompted is waited for each time - (consisting of <CODE>\n#</CODE>) and then the command is sent. - Note that the prompt is waited for before the command and not after, - so completion of the last command in the script is not - required. This is often used to invoke a program to monitor the - system, e.g. <CODE>ipsec pf_key</CODE>. -</P> -<DT>RUN_SCRIPT</DT> -<DD><P>a file of commands that is fed into the virtual machine's console - in single user mode, before the packets are sent. On single machine - tests, this script doesn't provide any more power than INIT_SCRIPT, - but is implemented for consistency's sake.</P> -<DT>FINAL_SCRIPT</DT> -<DD><p>a file of commands that is fed into the virtual machine's console - in single user mode after the final packet is sent. Similar to INIT_SCRIPT, - above. If not specified, then the single command "halt" is sent. - If specified, then the script should end with a halt command to - nicely shutdown the UML. -</P> -<DT>CONSOLEDIFFDEBUG</DT> -<DD>If set to "true" then the series of console fixups (see REF_CONSOLE_FIXUPS) will be output after it is constructed. (It should be set to "false", or unset otherwise)</DD> -<DT>NETJIGDEBUG</DT> -<DD>If set to "true" then the series of console fixups (see REF_CONSOLE_FIXUPS) will be output after it is constructed. (It should be set to "false", or unset otherwise)</DD> -<DT>NETJIGTESTDEBUG</DT> -<DD> If set to "netjig", then the results of talking to the <CODE>uml_netjig</CODE> -will be printed to stderr during the test. In addition, the jig will -be invoked with --debug, which causes it to log its process ID, and -wait 60 seconds before continuing. This can be used if you are trying -to debug the <CODE>uml_netjig</CODE> program itself.</DT> -<DT>HOSTTESTDEBUG</DT> -<DD> If set to "hosttest", then the results of taling to the consoles of the UMLs will -be printed to stderr during the test.</DT> -<DT>NETJIGWAITUSER</DT> -<DD> If set to "waituser", then the scripts will wait forever for user - input before they shut the tests down. Use this is if you are - debugging through the kernel.</DD> - -<DT>PACKETRATE</DT> -<DD> A number, in miliseconds (default is 500ms) at which packets will - be replayed by the netjig.</DD> -</DL> - - -<H2>KLIPStest paramaters</H2> -<P> -The klipstest function starts a program -(<CODE>testing/utils/uml_netjig/uml_netjig</CODE>) to -setup a bunch of I/O sockets (that simulate network interfaces). It -then exports the references to these sockets to the environment and -invokes (using system()) a given script. It waits for the script to -finish. -</P> - -<!-- <IMG SRC="single_netjig.png" ALT="block diagram of uml_netjig"> --> - -<P> -The script invoked (<CODE>testing/utils/host-test.tcl</CODE>) is a TCL -<A HREF="http://expect.nist.gov/">expect</A> script that arranges to start the UML -and configure it appropriately for the test. The configuration is done -with the script given above for <VAR>INIT_SCRIPT</VAR>. The TCL script then forks, -leaves the UML in the background and exits. uml_netjig continues. It then -starts listening to the simulated network answering ARPs and inserting -packets as appropriate. -</P> - -<P> -The klipstest function invokes <CODE>uml_netjig</CODE> with arguments -to capture output from network interface(s) and insert packets as -appropriate: -<DL> -<DT>PUB_INPUT</DT> -<DD>a <A HREF="http://www.tcpdump.org/">pcap</A> file to feed in on - the public (encrypted) interface. (typically, eth1)</DD> -<DT>PRIV_INPUT</DT> -<DD>a pcap file to feed in on the private (plain-text) interface - (typically, eth0).</DD> -<DT>REF_PUB_OUTPUT</DT> -<DD>a text file containing tcpdump output. Packets on the public - (eth1) interface are captured to a - <A HREF="http://www.tcpdump.org/">pcap</A> file by - <CODE>uml_netjig</CODE>. The klipstest function then uses tcpdump on - the file to produce text output, which is compared to the file given.</DD> -<DT>REF_PUB_FILTER</DT> -<DD>a program that will filter the TCPDUMP output to do further processing. Defaults to "cat".</DD> -<DT>REF_PRIV_OUTPUT</DT> -<DD>a text file containing tcpdump output. Packets on the private - (eth0) interface are captured and compared after conversion by - tcpdump, as with <VAR>REFPUBOUTPUT</VAR>.</DD> -<DT>REF_PRIV_FILTER</DT> -<DD>a program that will filter the TCPDUMP output to do further processing. Defaults to "cat".</DD> -<DT>EXITONEMPTY</DT> -<DD>a flag for <CODE>uml_netjig</CODE>. It should contain - "--exitonempty" of uml_netjig should exit when all of the input - (<VAR>PUBINPUT</VAR>,<VAR>PRIVINPUT</VAR>) packets have been injected.</DD> -<DT>ARPREPLY</DT> -<DD>a flag for <CODE>uml_netjig</CODE>. It should contain "--arpreply" - if <CODE>uml_netjig</CODE> should reply to ARP requests. One will - typically set this to avoid having to fudge the ARP cache manually.</DD> -<DT>TCPDUMPFLAGS</DT> -<DD>a set of flags for the tcpdump used when converting captured - output. Typical values will include "-n" to turn off DNS, and often - "-E" to set the decryption key (tcpdump 3.7.1 and higher only) for - ESP packets. The "-t" flag (turn off timestamps) is provided automatically</DD> - -<DT>NETJIG_EXTRA</DT> -<DD>additional comments to be sent to the netjig. This may arrange to - record or create additional networks, or may toggle options. -</DL> - -<H2>mkinsttest paramaters</H2> -<P> -The basic concept of the <CODE>mkinsttest</CODE> test type is that it -performs a "make install" to a temporary $DESTDIR. The resulting tree can then -be examined to determine if it was done properly. The files can be uninstalled -to determine if the file list was correct, or the contents of files can be -examined more precisely. -</P> - -<DL> -<DT>INSTALL_FLAGS</DT> -<DD>If set, then an install will be done. This provides the set of flags to -provide for the install. The target to be used (usually "install") must be -among the flags. </DD> -<DT>POSTINSTALL_SCRIPT</DT> -<DD>If set, a script to run after initial "make install". Two arguments are provided: an absolute path to the root of the FreeSWAN src tree, and an absolute path to the temporary installation area.</DD> -<DT>INSTALL2_FLAGS</DT> -<DD>If set, a second install will be done using these flags. Similarly to -INSTALL_FLAGS, the target must be among the flags. </DD> -<DT>UNINSTALL_FLAGS</DT> -<DD>If set, an uninstall will be done using these flags. Similarly to -INSTALL_FLAGS, the target (usually "uninstall") must be among the flags.</DD> -<DT>REF_FIND_f_l_OUTPUT</DT> -<DD>If set, a <CODE>find $ROOT ( -type f -or -type -l )</CODE> will be done to get a list of a real files and symlinks. The resulting file will be compared -to the file listed by this option.</DD> -<DT>REF_FILE_CONTENTS</DT> -<DD>If set, it should point to a file containing records for the form: -<PRE> - <VARIABLE>reffile</VARIABLE> <VARIABLE>samplefile</VARIABLE> -</PRE> -one record per line. A diff between the provided reference file, and the -sample file (located in the temporary installation root) will be done for -each record. -</DD> -</DL> - -<H2>rpm_build_install_test paramaters</H2> -<P> -The <CODE>rpm_build_install_test</CODE> type is to verify that the proper -packing list is produced by "make rpm", and that the mechanisms for -building the kernel modules produce consistent results. -</P> - -<DL> -<DT>RPM_KERNEL_SOURCE</DT> -<DD>Point to an extracted copy of the RedHat kernel source code. Variables -from the environment may be used.</DD> -<DT>REF_RPM_CONTENTS</DT> -<DD>This is a file containing one record per line. Each record consists -of a RPM name (may contain wildcards) and a filename to compare the -contents to. The RPM will be located and a file list will be produced with -rpm2cpio.</DD> -</DL> - -<H2>libtest paramaters</H2> -<P> -The libtest test is for testing library routines. The library file is -expected to provided an <CODE>#ifdef</CODE> by the name of -<VAR>library</VAR><CODE_MAIN</CODE>. -The libtest type invokes the C compiler to compile this file, links it against -<CODE>libfreeswan.a</CODE> (to resolve any other dependancies) and runs the -test with the <CODE>-r</CODE> argument to invoke a regression test.</P> -<P>The library test case is expected to do a self-test, exiting with status code 0 if everything is okay, and with non-zero otherwise. A core dump (exit code greater than 128) is noted specifically. -</P> -<P> -Unlike other tests, there are no subdirectories required, or other -parameters to set. -</P> - -<H2 NAME="umlplutotest">umlplutotest paramaters</H2> -<P> -The umlplutotest function starts a pair of user mode line processes. -This is a 2-host version of umlXhost. The "EAST" and "WEST" slots are defined. -</P> - -<H2 NAME="umlXhost">umlXhost parameters</H2> -<P> -The umlXtest function starts an arbitrary number of user mode line processes. -</P> - -<!-- <IMG SRC="single_netjig.png" ALT="block diagram of uml_netjig"> --> - -<P> -The script invoked (<CODE>testing/utils/Xhost-test.tcl</CODE>) is a TCL -<A HREF="http://expect.nist.gov/">expect</A> script that arranges to start each -UML -and configure it appropriately for the test. It then starts listening -(using uml_netjig) to the simulated network answering ARPs and -inserting packets as appropriate. -</P> - -<P> -umlXtest has a series of slots, each of which should be filled by a host. -The list of slots is controlled by the variable, XHOST_LIST. This variable -should be set to a space seperated list of slots. The former umlplutotest -is now implemented as a variation of the umlXhost test, -with XHOST_LIST="EAST WEST". -</P> - -<P> -For each host slot that is defined, a series of variables should be -filled in, defining what configuration scripts to use for that host. -</P> - -<P> -The following are used to control the console input and output to the system. -Where the string ${host} is present, the host slot should be filled in. -I.e. for the two host system with XHOST_LIST="EAST WEST", then the -variables: EAST_INIT_SCRIPT and WEST_INIT_SCRIPT will exist. -<DL> -<DT>${host}HOST</DT> -<DD>The name of the UML host which will fill this slot</DD> -<DT>${host}_INIT_SCRIPT</DT> -<DD><p>a file of commands that is fed into the virtual machine's console - in single user mode prior to starting the tests. This file will - usually set up any eroute's and SADB entries that are required for - the test. Similar to INIT_SCRIPT, above.</p> -<DT>${host}_RUN_SCRIPT</DT> -<DD><P>a file of commands that is fed into the virtual machine's console - in single user mode, before the packets are sent. This set of - commands is run after all of the virtual machines are initialized. - I.e. after EAST_INIT_SCRIPT <B>AND</B> WEST_INIT_SCRIPT. This script - can therefore do things that require that all machines are properly - configured.</P> -<DT>${host}_RUN2_SCRIPT</DT> -<DD><P>a file of commands that is fed into the virtual machine's console - in single user mode, after the packets are sent. This set of - commands is run before any of the virtual machines have been shut - down. (I.e. before EAST_FINAL_SCRIPT <B>AND</B> WEST_FINAL_SCRIPT.) - This script can therefore catch post-activity status reports.</P> -<DT>${host}_FINAL_SCRIPT</DT> -<DD><p>a file of commands that is fed into the virtual machine's console - in single user mode after the final packet is sent. Similar to INIT_SCRIPT, - above. If not specified, then the single command "halt" is sent. Note that - when this script is run, the other virtual machines may already have been killed. - If specified, then the script should end with a halt command to nicely - shutdown the UML. -</P> -<DT>REF_${host}_CONSOLE_OUTPUT</DT> -<DD>Similar to REF_CONSOLE_OUTPUT, above.</DT> -</DL> -</P> - -<P>Some additional flags apply to all hosts: -<DL> -<DT>REF_CONSOLE_FIXUPS</DT> -<DD>a list of scripts (found in <CODE>klips/test/fixups</CODE>) to - apply to sanitize the console output of the machine under test. - These are typically perl, awk or sed scripts that remove things in - the kernel output that change each time the test is run and/or - compiled. -</DD> -</DL> -</P> - -<P> In addition to input to the console, the networks may have input -fed to them: -<DL> -<DT>EAST_INPUT/WEST_INPUT</DT> -<DD>a <A HREF="http://www.tcpdump.org/">pcap</A> file to feed in on - the private network side of each network. The "EAST" and "WEST" here -refer to the networks, not the hosts.</DD> -<DT>REF_PUB_FILTER</DT> -<DD>a program that will filter the TCPDUMP output to do further processing. Defaults to "cat".</DD> -<DT>REF_EAST_FILTER/REF_WEST_FILTER</DT> -<DD>a program that will filter the TCPDUMP output to do further processing. Defaults to "cat".</DD>< -<DT>TCPDUMPFLAGS</DT> -<DD>a set of flags for the tcpdump used when converting captured - output. Typical values will include "-n" to turn off DNS, and often - "-E" to set the decryption key (tcpdump 3.7.1 and higher only) for - ESP packets. The "-t" flag (turn off timestamps) is provided automatically</DD> -<DT>REF_EAST_OUTPUT/REF_WEST_OUTPUT</DT> -<DD>a text file containing tcpdump output. Packets on the private - (eth0) interface are captured and compared after conversion by - tcpdump, as with <VAR>REF_PUB_OUTPUT</VAR>.</DD> -</P> - -<P> -There are two additional environment variables that may be set on the -command line: -<DL> -<DT> NETJIGVERBOSE=verbose export NETJIGVERBOSE</DT> -<DD> If set, then the test output will be "chatty", and let you know what - commands it is running, and as packets are sent. Without it set, the - output is limited to success/failure messages.</DD> -<DT> NETJIGTESTDEBUG=netjig export NETJIGTESTDEBUG</DT> -<DD> This will enable debugging of the communication with uml_netjig, - and turn on debugging in this utility. - This does not imply NETJIGVERBOSE.</DL> -<DT> HOSTTESTDEBUG=hosttest export HOSTTESTDEBUG</DT> -<DD> This will show all interactions with the user-mode-linux - consoles</DD> -</DL> -</P> - -<H2 NAME="kernelpatch">kernel_patch_test paramaters</H2> -<P> -The kernel_patch_test function takes some kernel source, copies it with -lndir, and then applies the patch as produced by "make kernelpatch". -</P> -<P> -The following are used to control the input and output to the system: -<DL> -<DT>KERNEL_NAME</DT> -<DD>the kernel name, typically something like "linus" or "rh"</DD> -<DT>KERNEL_VERSION</DT> -<DD>the kernel version number, as in "2.2" or "2.4".</DD> -<DT>KERNEL_${KERNEL_NAME}${KERNEL_VERSION}_SRC</DT> -<DD>This variable should set in the environment, probably in - ~/freeswan-regress-env.sh. Examples of this variables would be - KERNEL_LINUS2_0_SRC or KERNEL_RH7_3_SRC. This variable should point - to an extracted copy of the kernel source in question.</DD> -<DT>REF_PATCH_OUTPUT</DT> -<DD>a copy of the patch output to compare against</DD> -<DT>KERNEL_PATCH_LEAVE_SOURCE</DT> -<DD>If set to a non-empty string, then the patched kernel source is not - removed at the end of the test. This will typically be set in the - environment while debugging.</DD> -</DL> -</P> - -<H2 NAME="modtest">module_compile paramaters</H2> -<P> -The module_compile test attempts to build the KLIPS module against a -given set of kernel source. This is also done by the RPM tests, but -in a very specific manner. -</P> -<P> -There are two variations of this test - one where the kernel either -doesn't need to be configured, or is already done, and tests were there -is a local configuration file. -</P> -<P> -Where the kernel doesn't need to be configured, the kernel source that -is found is simply used. It may be a RedHat-style kernel, where one -can cause it to configure itself via rhconfig.h-style definitions. Or, -it may just be a kernel tree that has been configured. -</P> -<P> -If the variable KERNEL_CONFIG_FILE is set, then a new directory is -created for the kernel source. It is populated with lndir(1). The referenced -file is then copied in as .config, and "make oldconfig" is used to configure -the kernel. This resulting kernel is then used as the reference source. -</P> -<p> -In all cases, the kernel source is found the same was for the kernelpatch -test, i.e. via KERNEL_VERSION/KERNEL_NAME and KERNEL_${KERNEL_NAME}${KERNEL_VERSION}_SRC.</P> -<P> -Once there is kernel source, the module is compiled using the top-level -"make module" target. -</P> -<P> -The test is considered successful if an executable is found in OUTPUT/module/ipsec.o at the end of the test. -</P> -<DL> -<DT>KERNEL_NAME</DT> -<DD>the kernel name, typically something like "linus" or "rh"</DD> -<DT>KERNEL_VERSION</DT> -<DD>the kernel version number, as in "2.2" or "2.4".</DD> -<DT>KERNEL_${KERNEL_NAME}${KERNEL_VERSION}_SRC</DT> -<DD>This variable should set in the environment, probably in - ~/freeswan-regress-env.sh. Examples of this variables would be - KERNEL_LINUS2_0_SRC or KERNEL_RH7_3_SRC. This variable should point - to an extracted copy of the kernel source in question.</DD> -<DT>KERNEL_CONFIG_FILE</DT> -<DD>The configuration file for the kernel.</DD> -<DT>KERNEL_PATCH_LEAVE_SOURCE</DT> -<DD>If set to a non-empty string, then the configured kernel source is not - removed at the end of the test. This will typically be set in the - environment while debugging.</DD> -<DT>MODULE_DEF_INCLUDE</DT> -<DD>The include file that will be used to configure the KLIPS module, and - possibly the kernel source. </DD> -</DL> - -<H1>Current pitfalls</H1> - -<DL> -<DT> "tcpdump dissector" not available. </DT> -<DD> This is a non-fatal warning. If uml_netjig is invoked with the -t - option, then it will attempt to use tcpdump's dissector to decode - each packet that it processes. The dissector is presently not - available, so this option it normally turned off at compile time. - The dissector library will be released with tcpdump version - 4.0.</DD> -</DL> - -</body> -</html>
\ No newline at end of file diff --git a/doc/src/manpages.html b/doc/src/manpages.html deleted file mode 100644 index 27a9aa7b3..000000000 --- a/doc/src/manpages.html +++ /dev/null @@ -1,155 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>FreeS/WAN man pages</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, manpage, manual, page"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: manpages.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1><a name="manpages">FreeS/WAN manual pages</a></h1> - -<p>The various components of Linux FreeS/WAN are of course documented in -standard Unix manual pages, accessible via the man(1) command.</p> - -<p>Links here take you to an HTML version of the man pages.</p> - -<h2><a name="man.file">Files</a></h2> -<dl> - <dt><a href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a></dt> - <dd>IPsec configuration and connections</dd> - <dt><a href="manpage.d/ipsec.secrets.5.html">ipsec.secrets(5)</a></dt> - <dd>secrets for IKE authentication, either pre-shared keys or RSA private - keys</dd> -</dl> - -<p>These files are also discussed in the <a -href="config.html">configuration</a> section.</p> - -<h2><a name="man.command">Commands</a></h2> - -<p>Many users will never give most of the FreeS/WAN commands directly. -Configure the files listed above correctly and everything should be -automatic.</p> - -<p>The exceptions are commands for mainpulating the <a -href="glossary.html#RSA">RSA</a> keys used in Pluto authentication:</p> -<dl> - <dt><a href="manpage.d/ipsec_rsasigkey.8.html">ipsec_rsasigkey(8)</a></dt> - <dd>generate keys</dd> - <dt><a href="manpage.d/ipsec_newhostkey.8.html">ipsec_newhostkey(8)</a></dt> - <dd>generate keys in a convenient format</dd> - <dt><a - href="manpage.d/ipsec_showhostkey.8.html">ipsec_showhostkey(8)</a></dt> - <dd>extract <a href="glossary.html#RSA">RSA</a> keys from <a - href="manpage.d/ipsec.secrets.5.html">ipsec.secrets(5)</a> (or - optionally, another file) and format them for insertion in <a - href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a> or in DNS - records</dd> -</dl> - -<p>Note that:</p> -<ul> - <li>These keys are for <strong>authentication only</strong>. They are - <strong>not secure for encryption</strong>.</li> - <li>The utility uses random(4) as a source of <a - href="glossary.html#random">random numbers</a>. This may block for some - time if there is not enough activity on the machine to provide the - required entropy. You may want to give it some bogus activity such as - random mouse movements or some command such as <nobr><tt>du /usr > /dev/null - &</tt></nobr>.</li> -</ul> - -<p>The following commands are fairly likely to be used, if only for testing -and status checks:</p> -<dl> - <dt><a href="manpage.d/ipsec.8.html">ipsec(8)</a></dt> - <dd>invoke IPsec utilities</dd> - <dt><a href="manpage.d/ipsec_setup.8.html">ipsec_setup(8)</a></dt> - <dd>control IPsec subsystem</dd> - <dt><a href="manpage.d/ipsec_auto.8.html">ipsec_auto(8)</a></dt> - <dd>control automatically-keyed IPsec connections</dd> - <dt><a href="manpage.d/ipsec_manual.8.html">ipsec_manual(8)</a></dt> - <dd>take manually-keyed IPsec connections up and down</dd> - <dt><a href="manpage.d/ipsec_ranbits.8.html">ipsec_ranbits(8)</a></dt> - <dd>generate random bits in ASCII form</dd> - <dt><a href="manpage.d/ipsec_look.8.html">ipsec_look(8)</a></dt> - <dd>show minimal debugging information</dd> - <dt><a href="manpage.d/ipsec_barf.8.html">ipsec_barf(8)</a></dt> - <dd>spew out collected IPsec debugging information</dd> -</dl> - -<p>The lower-level utilities listed below are normally invoked via scripts -listed above, but they can also be used directly when required.</p> -<dl> - <dt><a href="manpage.d/ipsec_eroute.8.html">ipsec_eroute(8)</a></dt> - <dd>manipulate IPsec extended routing tables</dd> - <dt><a href="manpage.d/ipsec_klipsdebug.8.html">ipsec_klipsdebug(8)</a></dt> - <dd>set Klips (kernel IPsec support) debug features and level</dd> - <dt><a href="manpage.d/ipsec_pluto.8.html">ipsec_pluto(8)</a></dt> - <dd>IPsec IKE keying daemon</dd> - <dt><a href="manpage.d/ipsec_spi.8.html">ipsec_spi(8)</a></dt> - <dd>manage IPsec Security Associations</dd> - <dt><a href="manpage.d/ipsec_spigrp.8.html">ipsec_spigrp(8)</a></dt> - <dd>group/ungroup IPsec Security Associations</dd> - <dt><a href="manpage.d/ipsec_tncfg.8.html">ipsec_tncfg(8)</a></dt> - <dd>associate IPsec virtual interface with real interface</dd> - <dt><a href="manpage.d/ipsec_whack.8.html">ipsec_whack(8)</a></dt> - <dd>control interface for IPsec keying daemon</dd> -</dl> - -<h2><a name="man.lib">Library routines</a></h2> -<dl> - <dt><a href="manpage.d/ipsec_atoaddr.3.html">ipsec_atoaddr(3)</a></dt> - <dt><a href="manpage.d/ipsec_addrtoa.3.html">ipsec_addrtoa(3)</a></dt> - <dd>convert Internet addresses to and from ASCII</dd> - <dt><a href="manpage.d/ipsec_atosubnet.3.html">ipsec_atosubnet(3)</a></dt> - <dt><a href="manpage.d/ipsec_subnettoa.3.html">ipsec_subnettoa(3)</a></dt> - <dd>convert subnet/mask ASCII form to and from addresses</dd> - <dt><a href="manpage.d/ipsec_atoasr.3.html">ipsec_atoasr(3)</a></dt> - <dd>convert ASCII to Internet address, subnet, or range</dd> - <dt><a href="manpage.d/ipsec_rangetoa.3.html">ipsec_rangetoa(3)</a></dt> - <dd>convert Internet address range to ASCII</dd> - <dt>ipsec_atodata(3)</dt> - <dt><a href="manpage.d/ipsec_datatoa.3.html">ipsec_datatoa(3)</a></dt> - <dd>convert binary data from and to ASCII formats</dd> - <dt><a href="manpage.d/ipsec_atosa.3.html">ipsec_atosa(3)</a></dt> - <dt><a href="manpage.d/ipsec_satoa.3.html">ipsec_satoa(3)</a></dt> - <dd>convert IPsec Security Association IDs to and from ASCII</dd> - <dt><a href="manpage.d/ipsec_atoul.3.html">ipsec_atoul(3)</a></dt> - <dt><a href="manpage.d/ipsec_ultoa.3.html">ipsec_ultoa(3)</a></dt> - <dd>convert unsigned-long numbers to and from ASCII</dd> - <dt><a href="manpage.d/ipsec_goodmask.3.html">ipsec_goodmask(3)</a></dt> - <dd>is this Internet subnet mask a valid one?</dd> - <dt><a href="manpage.d/ipsec_masktobits.3.html">ipsec_masktobits(3)</a></dt> - <dd>convert Internet subnet mask to bit count</dd> - <dt><a href="manpage.d/ipsec_bitstomask.3.html">ipsec_bitstomask(3)</a></dt> - <dd>convert bit count to Internet subnet mask</dd> - <dt><a - href="manpage.d/ipsec_optionsfrom.3.html">ipsec_optionsfrom(3)</a></dt> - <dd>read additional ``command-line'' options from file</dd> - <dt><a href="manpage.d/ipsec_subnetof.3.html">ipsec_subnetof(3)</a></dt> - <dd>given Internet address and subnet mask, return subnet number</dd> - <dt><a href="manpage.d/ipsec_hostof.3.html">ipsec_hostof(3)</a></dt> - <dd>given Internet address and subnet mask, return host part</dd> - <dt><a - href="manpage.d/ipsec_broadcastof.3.html">ipsec_broadcastof(3)</a></dt> - <dd>given Internet address and subnet mask, return broadcast address</dd> -</dl> -</body> -</html> diff --git a/doc/src/nightly.html b/doc/src/nightly.html deleted file mode 100644 index d86037884..000000000 --- a/doc/src/nightly.html +++ /dev/null @@ -1,164 +0,0 @@ -<html> -<head> -<title>FreeS/WAN nightly testing guide</title> -<!-- Changed by: Michael Richardson, 23-Jul-2002 --> -<meta name="keywords" content="Linux, IPsec, VPN, security, FreeSWAN, testing, User-Mode-Linux, UML"> - -<!-- - -Written by Michael Richardson for the Linux FreeS/WAN project -Freely distributable under the GNU General Public License - -More information at www.freeswan.org -Feedback to users@lists.freeswan.org - -$Id: nightly.html,v 1.1 2004/03/15 20:35:24 as Exp $ - -$Log: nightly.html,v $ -Revision 1.1 2004/03/15 20:35:24 as -added files from freeswan-2.04-x509-1.5.3 - -Revision 1.3 2002/07/23 18:42:16 mcr - added instructions on setup of nightly build. - -Revision 1.2 2002/06/19 10:06:07 mcr - added nightly.html to the documentation tree. - -Revision 1.1 2002/05/24 03:33:30 mcr - start at document on nightly regression testing. - - ---> -</head> - -<body> - -<h1><a name="nightly">Nightly regression testing</a></h1> - -<p> -The nightly regression testing system consists of several shell scripts -and some perl scripts. The goal is to check out a fresh tree, run "make check" on it, -record the results and summarize the results to the team and to the web site. -</p> - -<P> -Output can be found on <A HREF="http://bugs.freeswan.org:81/">adams</A>, -although the tests are actually run on another project machine.</P> - -<H1><A name="nightlyhowto">How to setup the nightly build</A></h1> - -<P> -The best way to do nightly testing is to setup a new account. We call the -account "build" - you could call it something else, but there may -still be some references to ~build in the scripts. -</P> - -<H2> Files you need to know about </H2> -<P> -As few files as possible need to be extracted from the source tree - -files are run from the source tree whenever possible. However, there -are some bootstrap and configuration files that are necessary. -</P> - -<P> -There are 7 files in testing/utils that are involved: -<DL> -<DT> nightly-sample.sh </DT> -<DD> This is the root of the build process. This file should be copied out -of the CVS tree, to $HOME/bin/nightly.sh of the build account. This -file should be invoked from cron. </DD> -<DT> freeswan-regress-env-sample.sh </DT> -<DD> This file should be copied to $HOME/freeswan-regress-env.sh. It - should be edited to localize the values. See below.</DD> -<DT> regress-cleanup.pl </DT> -<DD> This file needs to be copied to $HOME/bin/regress-cleanup.pl. It - is invoked by the nightly file before doing anything else. It - removes previous nights builds in order to free up disk space for - the build about to be done.</DD> -<DT> teammail-sample.sh </DT> -<DD> A script used to send results email to the "team". This sample - script could be copied to $HOME/bin/teammail.sh. This version will - PGP encrypt all the output to the team members. If this script is used, - then PGP will have to be properly setup to have the right keys.</DD> -<DT> regress-nightly.sh </DT> -<DD> This is the first stage of the nightly build. This stage will - call other scripts as appropriate, and will extract the source code - from CVS. This script should be copied to $HOME/bin/regress-nightly.sh</DD> -<DT> regress-stage2.sh </DT> -<DD> This is the second stage of the nightly build. It is called in - place. It essentially sets up the UML setup in umlsetup.sh, and - calls "make check".</DD> -<DT> regress-summarize-results.pl -<DD> This script will summarize the results from the tests to a - permanent directory set by $REGRESSRESULTS. It is invoked from the - stage2 nightly script. -<DT> regress-chart.sh </DT> -<DD> This script is called at the end of the build process, and will - summarize each night's results (as saved into $REGRESSRESULTS by - regress-summarize-results.pl) as a chart using gnuplot. Note that - this requires at least gnuplot 3.7.2.</DD> -</DL> - -<H2>Configuring freeswan-regress-env.sh</H2> - -<P>For more info on KERNPOOL, UMLPATCH, BASICROOT and SHAREDIR, see - <A HREF="umltesting.html">User-Mode-Linux testing guide</A>. -</P> - -<DL> -<DT> KERNPOOL </DT> -<DD> Extract copy of some kernel source to be used for UML builds</DD> -<DT> UMLPATCH </DT> -<DD> matching User-Mode-Linux patch.</DD> -<DT> BASICROOT</DT> -<DD> the root file system image (see - <A HREF="umltesting.html">User-Mode-Linux testing guide</A>).</DD> -<DT> SHAREDIR=${BASICROOT}/usr/share</DT> -<DD> The /usr/share to use.</DD> -<DT> REGRESSTREE</DT> -<DD> A directory in which to store the nightly regression - results. Directories will be created by date in this tree.</DD> - -<DT> TCPDUMP=tcpdump-3.7.1</DT> -<DD> The path to the <A HREF="http://www.tcpdump.org/">tcpdump</A> - to use. This must have crypto compiled in, and must be at least 3.7.1</DT> - -<DT> KERNEL_RH7_2_SRC=/a3/kernel_sources/linux-2.4.9-13/</DT> -<DD> An extracted copy of the RedHat 7.2. kernel source. If set, then - the packaging/rpm-rh72-install-01 test will be run, and an RPM will - be built as a test.</DD> - -<DT> KERNEL_RH7_3_SRC=/a3/kernel_sources/rh/linux-2.4.18-5</DT> -<DD> An extracted copy of the RedHat 7.3. kernel source. If set, then - the packaging/rpm-rh73-install-01 test will be run, and an RPM will - be built as a test.</DD> - -<DT> NIGHTLY_WATCHERS="userid,userid,userid"</DT> -<DD> The list of people who should receive nightly output. This is - used by teammail.sh</DD> - -<DT> FAILLINES=128</DT> -<DD> How many lines of failed test output to include in the nightly - output</DD> - -<DT> PATH=$PATH:/sandel/bin export PATH</DT> -<DD> You can also override the path if necessary here.</DD> - -<DT> CVSROOT=:pserver:anoncvs@ip212.xs4net.freeswan.org:/freeswan/MASTER</DT> -<DD> The CVSROOT to use. This example may work for anonymous CVS, but - will be 12 hours behind the primary, and is still experimental</DD> - -<DT> SNAPSHOTSIGDIR=$HOME/snapshot-sig</DT> -<DD> For the release tools, where to put the generated per-snapshot - signature keys</DD> - -<DT> LASTREL=1.97</DT> -<DD> the name of the last release branch (to find the right - per-snapshot signature</DT> - -<DD> - -</DL> - -</body> -</html>
\ No newline at end of file diff --git a/doc/src/performance.html b/doc/src/performance.html deleted file mode 100755 index 9d90acc62..000000000 --- a/doc/src/performance.html +++ /dev/null @@ -1,576 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>FreeS/WAN performance</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, performance, benchmark"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: performance.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1><a name="performance">Performance of FreeS/WAN</a></h1> -The performance of FreeS/WAN is adequate for most applications. - -<p>In normal operation, the main concern is the overhead for encryption, -decryption and authentication of the actual IPsec (<a -href="glossary.html#ESP">ESP</a> and/or <a href="glossary.html#AH">AH</a>) -data packets. Tunnel setup and rekeying occur so much less frequently than -packet processing that, in general, their overheads are not worth worrying -about.</p> - -<p>At startup, however, tunnel setup overheads may be significant. If you -reboot a gateway and it needs to establish many tunnels, expect some delay. -This and other issues for large gateways are discussed <a -href="#biggate">below</a>.</p> - -<h2><a name="pub.bench">Published material</a></h2> - -<p>The University of Wales at Aberystwyth has done quite detailed speed tests -and put <a href="http://tsc.llwybr.org.uk/public/reports/SWANTIME/">their -results</a> on the web.</p> - -<p>Davide Cerri's <a href="http://www.linux.it/~davide/doc/">thesis (in -Italian)</a> includes performance results for FreeS/WAN and for <a -href="glossary.html#TLS">TLS</a>. He posted an <a -href="http://lists.freeswan.org/pipermail/users/2001-December/006303.html">English -summary</a> on the mailing list.</p> - -<p>Steve Bellovin used one of AT&T Research's FreeS/WAN gateways as his -data source for an analysis of the cache sizes required for key swapping in -IPsec. Available as <a -href="http://www.research.att.com/~smb/talks/key-agility.email.txt">text</a> -or <a href="http://www.research.att.com/~smb/talks/key-agility.pdf">PDF -slides</a> for a talk on the topic.</p> - -<p>See also the NAI work mentioned in the next section.</p> - -<h2><a name="perf.estimate">Estimating CPU overheads</a></h2> - -<p>We can come up with a formula that roughly relates CPU speed to the rate -of IPsec processing possible. It is far from exact, but should be usable as a -first approximation.</p> - -<p>An analysis of authentication overheads for high-speed networks, including -some tests using FreeS/WAN, is on the <a -href="http://www.pgp.com/research/nailabs/cryptographic/adaptive-cryptographic.asp">NAI -Labs site</a>. In particular, see figure 3 in this <a -href="http://download.nai.com/products/media/pgp/pdf/acsa_final_report.pdf">PDF -document</a>. Their estimates of overheads, measured in Pentium II cycles per -byte processed are:</p> - -<table border="1" align="center"> - <tbody> - <tr> - <th></th> - <th>IPsec</th> - <th>authentication</th> - <th>encryption</th> - <th>cycles/byte</th> - </tr> - <tr> - <td>Linux IP stack alone</td> - <td>no</td> - <td>no</td> - <td>no</td> - <td align="right">5</td> - </tr> - <tr> - <td>IPsec without crypto</td> - <td>yes</td> - <td>no</td> - <td>no</td> - <td align="right">11</td> - </tr> - <tr> - <td>IPsec, authentication only</td> - <td>yes</td> - <td>SHA-1</td> - <td>no</td> - <td align="right">24</td> - </tr> - <tr> - <td>IPsec with encryption</td> - <td>yes</td> - <td>yes</td> - <td>yes</td> - <td align="right">not tested</td> - </tr> - </tbody> -</table> - -<p>Overheads for IPsec with encryption were not tested in the NAI work, but -Antoon Bosselaers' <a -href="http://www.esat.kuleuven.ac.be/~bosselae/fast.html">web page</a> gives -cost for his optimised Triple DES implementation as 928 Pentium cycles per -block, or 116 per byte. Adding that to the 24 above, we get 140 cycles per -byte for IPsec with encryption.</p> - -<p>At 140 cycles per byte, a 140 MHz machine can handle a megabyte -- 8 -megabits -- per second. Speeds for other machines will be proportional to -this. To saturate a link with capacity C megabits per second, you need a -machine running at <var>C * 140/8 = C * 17.5</var> MHz.</p> - -<p>However, that estimate is not precise. It ignores the differences -between:</p> -<ul> - <li>NAI's test packets and real traffic</li> - <li>NAI's Pentium II cycles, Bosselaers' Pentium cycles, and your machine's - cycles</li> - <li>different 3DES implementations</li> - <li>SHA-1 and MD5</li> -</ul> - -<p>and does not account for some overheads you will almost certainly have:</p> -<ul> - <li>communication on the client-side interface</li> - <li>switching between multiple tunnels -- re-keying, cache reloading and so - on</li> -</ul> - -<p>so we suggest using <var>C * 25</var> to get an estimate with a bit of a -built-in safety factor.</p> - -<p>This covers only IP and IPsec processing. If you have other loads on your -gateway -- for example if it is also working as a firewall -- then you will -need to add your own safety factor atop that.</p> - -<p>This estimate matches empirical data reasonably well. For example, -Metheringham's tests, described <a href="#klips.bench">below</a>, show a 733 -topping out between 32 and 36 Mbit/second, pushing data as fast as it can -down a 100 Mbit link. Our formula suggests you need at least an 800 to handle -a fully loaded 32 Mbit link. The two results are consistent.</p> - -<p>Some examples using this estimation method:</p> - -<table border="1" align="center"> - <tbody> - <tr> - <th colspan="2">Interface</th> - <th colspan="3">Machine speed in MHz</th> - </tr> - <tr> - <th>Type</th> - <th>Mbit per<br> - second</th> - <th>Estimate<br> - Mbit*25</th> - <th>Minimum IPSEC gateway</th> - <th>Minimum with other load - - <p>(e.g. firewall)</p> - </th> - </tr> - <tr> - <td>DSL</td> - <td align="right">1</td> - <td align="right">25 MHz</td> - <td rowspan="2">whatever you have</td> - <td rowspan="2">133, or better if you have it</td> - </tr> - <tr> - <td>cable modem</td> - <td align="right">3</td> - <td align="right">75 MHz</td> - </tr> - <tr> - <td><strong>any link, light load</strong></td> - <td align="right"><strong>5</strong></td> - <td align="right">125 MHz</td> - <td>133</td> - <td>200+, <strong>almost any surplus machine</strong></td> - </tr> - <tr> - <td>Ethernet</td> - <td align="right">10</td> - <td align="right">250 MHz</td> - <td>surplus 266 or 300</td> - <td>500+</td> - </tr> - <tr> - <td><strong>fast link, moderate load</strong></td> - <td align="right"><strong>20</strong></td> - <td align="right">500 MHz</td> - <td>500</td> - <td>800+, <strong>any current off-the-shelf PC</strong></td> - </tr> - <tr> - <td>T3 or E3</td> - <td align="right">45</td> - <td align="right">1125 MHz</td> - <td>1200</td> - <td>1500+</td> - </tr> - <tr> - <td>fast Ethernet</td> - <td align="right">100</td> - <td align="right">2500 MHz</td> - <td rowspan="2" colspan="2" align="center">// not feasible with 3DES in - software on current machines //</td> - </tr> - <tr> - <td>OC3</td> - <td align="right">155</td> - <td align="right">3875 MHz</td> - </tr> - </tbody> -</table> - -<p>Such an estimate is far from exact, but should be usable as minimum -requirement for planning. The key observations are:</p> -<ul> - <li>older <strong>surplus machines</strong> are fine for IPsec gateways at - loads up to <strong>5 megabits per second</strong> or so</li> - <li>a <strong>mid-range new machine</strong> can handle IPsec at rates up - to <strong>20 megabits per second</strong> or more</li> -</ul> - <h3><a name="perf.more">Higher performance alternatives</a></h3> - - <p><a href="glossary.html#AES">AES</a> is a new US government block cipher - standard, designed to replace the obsolete <a - href="glossary.html#DES">DES</a>. If FreeS/WAN using <a - href="glossary.html#3DES">3DES</a> is not fast enough for your application, - the AES <a href="web.html#patch">patch</a> may help.</p> - - <p>To date (March 2002) we have had only one <a - href="http://lists.freeswan.org/pipermail/users/2002-February/007771.html">mailing - list report</a> of measurements with the patch applied. It indicates that, - at least for the tested load on that user's network, <strong>AES roughly - doubles IPsec throughput</strong>. If further testing confirms this, it may - prove possible to saturate an OC3 link in software on a high-end box.</p> - - <p>Also, some work is being done toward support of <a - href="compat.html#hardware">hardware IPsec acceleration</a> which might - extend the range of requirements FreeS/WAN could meet.</p> - - <h3>Other considerations</h3> - - <p>CPU speed may be the main issue for IPsec performance, but of course it - isn't the only one.</p> - - <p>You need good ethernet cards or other network interface hardware to get - the best performance. See this <a - href="http://www.ethermanage.com/ethernet/ethernet.html">ethernet - information</a> page and this <a href="http://www.scyld.com/diag">Linux - network driver</a> page.</p> - - <p>The current FreeS/WAN kernel code is largely single-threaded. It is SMP - safe, and will run just fine on a multiprocessor machine (<a - href="compat.html#multiprocessor">discussion</a>), but the load within the - kernel is not shared effectively. This means that, for example to saturate - a T3 -- which needs about a 1200 MHz machine -- you cannot expect something - like a dual 800 to do the job. </p> - - <p>On the other hand, SMP machines do tend to share loads well so -- - provided one CPU is fast enough for the IPsec work -- a multiprocessor - machine may be ideal for a gateway with a mixed load.</p> - - <h2><a name="biggate">Many tunnels from a single gateway</a></h2> - - <p>FreeS/WAN allows a single gateway machine to build tunnels to many - others. There may, however, be some problems for large numbers as indicated - in this message from the mailing list:</p> - -<pre>Subject: Re: Maximum number of ipsec tunnels? - Date: Tue, 18 Apr 2000 - From: "John S. Denker" <jsd@research.att.com> - -Christopher Ferris wrote: - ->> What are the maximum number ipsec tunnels FreeS/WAN can handle?? - -Henry Spencer wrote: - ->There is no particular limit. Some of the setup procedures currently ->scale poorly to large numbers of connections, but there are (clumsy) ->workarounds for that now, and proper fixes are coming. - -1) "Large" numbers means anything over 50 or so. I routinely run boxes -with about 200 tunnels. Once you get more than 50 or so, you need to worry -about several scalability issues: - -a) You need to put a "-" sign in syslogd.conf, and rotate the logs daily -not weekly. - -b) Processor load per tunnel is small unless the tunnel is not up, in which -case a new half-key gets generated every 90 seconds, which can add up if -you've got a lot of down tunnels. - -c) There's other bits of lore you need when running a large number of -tunnels. For instance, systematically keeping the .conf file free of -conflicts requires tools that aren't shipped with the standard freeswan -package. - -d) The pluto startup behavior is quadratic. With 200 tunnels, this eats up -several minutes at every restart. I'm told fixes are coming soon. - -2) Other than item (1b), the CPU load depends mainly on the size of the -pipe attached, not on the number of tunnels. -</pre> - -<p>It is worth noting that item (1b) applies only to repeated attempts to -re-key a data connection (IPsec SA, Phase 2) over an established keying -connection (ISAKMP SA, Phase 1). There are two ways to reduce this overhead -using settings in <a href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</a>:</p> -<ul> - <li>set <var>keyingtries</var> to some small value to limit repetitions</li> - <li>set <var>keylife</var> to a short time so that a failing data - connection will be cleaned up when the keying connection is reset.</li> -</ul> - -<p>The overheads for establishing keying connections (ISAKMP SAs, Phase 1) -are lower because for these Pluto does not perform expensive operations -before receiving a reply from the peer.</p> - -<p>A gateway that does a lot of rekeying -- many tunnels and/or low settings -for tunnel lifetimes -- will also need a lot of <a -href="glossary.html#random">random numbers</a> from the random(4) driver.</p> - -<h2><a name="low-end">Low-end systems</a></h2> - -<p><em>Even a 486 can handle a T1 line</em>, according to this mailing list -message:</p> -<pre>Subject: Re: linux-ipsec: IPSec Masquerade - Date: Fri, 15 Jan 1999 11:13:22 -0500 - From: Michael Richardson - -. . . A 486/66 has been clocked by Phil Karn to do -10Mb/s encryption.. that uses all the CPU, so half that to get some CPU, -and you have 5Mb/s. 1/3 that for 3DES and you get 1.6Mb/s....</pre> - -<p>and a piece of mail from project technical lead Henry Spencer:</p> -<pre>Oh yes, and a new timing point for Sandy's docs... A P60 -- yes, a 60MHz -Pentium, talk about antiques -- running a host-to-host tunnel to another -machine shows an FTP throughput (that is, end-to-end results with a real -protocol) of slightly over 5Mbit/s either way. (The other machine is much -faster, the network is 100Mbps, and the ether cards are good ones... so -the P60 is pretty definitely the bottleneck.)</pre> - -<p>From the above, and from general user experience as reported on the list, -it seems clear that a cheap surplus machine -- a reasonable 486, a minimal -Pentium box, a Sparc 5, ... -- can easily handle a home office or a small -company connection using any of:</p> -<ul> - <li>ADSL service</li> - <li>cable modem</li> - <li>T1</li> - <li>E1</li> -</ul> - -<p>If available, we suggest using a Pentium 133 or better. This should ensure -that, even under maximum load, IPsec will use less than half the CPU cycles. -You then have enough left for other things you may want on your gateway -- -firewalling, web caching, DNS and such.</p> - -<h2><a name="klips.bench">Measuring KLIPS</a></h2> - -<p>Here is some additional data from the mailing list.</p> -<pre>Subject: FreeSWAN (specically KLIPS) performance measurements - Date: Thu, 01 Feb 2001 - From: Nigel Metheringham <Nigel.Metheringham@intechnology.co.uk> - -I've spent a happy morning attempting performance tests against KLIPS -(this is due to me not being able to work out the CPU usage of KLIPS so -resorting to the crude measurements of maximum throughput to give a -baseline to work out loading of a box). - -Measurements were done using a set of 4 boxes arranged in a line, each -connected to the next by 100Mbit duplex ethernet. The inner 2 had an -ipsec tunnel between them (shared secret, but I was doing measurements -when the tunnel was up and running - keying should not be an issue -here). The outer pair of boxes were traffic generators or traffic sink. - -The crypt boxes are Compaq DL380s - Uniprocessor PIII/733 with 256K -cache. They have 128M main memory. Nothing significant was running on -the boxes other than freeswan. The kernel was a 2.2.19pre7 patched -with freeswan and ext3. - -Without an ipsec tunnel in the chain (ie the 2 inner boxes just being -100BaseT routers), throughput (measured with ttcp) was between 10644 -and 11320 KB/sec - -With an ipsec tunnel in place, throughput was between 3268 and 3402 -KB/sec - -These measurements are for data pushed across a TCP link, so the -traffic on the wire between the 2 ipsec boxes would have been higher -than this.... - -vmstat (run during some other tests, so not affecting those figures) on -the encrypting box shows approx 50% system & 50% idle CPU - which I -don't believe at all. Interactive feel of the box was significantly -sluggish. - -I also tried running the kernel profiler (see man readprofile) during -test runs. - -A box doing primarily decrypt work showed basically nothing happening - -I assume interrupts were off. -A box doing encrypt work showed the following:- - Ticks Function Load - ~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~ - 956 total 0.0010 - 532 des_encrypt2 0.1330 - 110 MD5Transform 0.0443 - 97 kmalloc 0.1880 - 39 des_encrypt3 0.1336 - 23 speedo_interrupt 0.0298 - 14 skb_copy_expand 0.0250 - 13 ipsec_tunnel_start_xmit 0.0009 - 13 Decode 0.1625 - 11 handle_IRQ_event 0.1019 - 11 .des_ncbc_encrypt_end 0.0229 - 10 speedo_start_xmit 0.0188 - 9 satoa 0.0225 - 8 kfree 0.0118 - 8 ip_fragment 0.0121 - 7 ultoa 0.0365 - 5 speedo_rx 0.0071 - 5 .des_encrypt2_end 5.0000 - 4 _stext 0.0140 - 4 ip_fw_check 0.0035 - 2 rj_match 0.0034 - 2 ipfw_output_check 0.0200 - 2 inet_addr_type 0.0156 - 2 eth_copy_and_sum 0.0139 - 2 dev_get 0.0294 - 2 addrtoa 0.0143 - 1 speedo_tx_buffer_gc 0.0024 - 1 speedo_refill_rx_buf 0.0022 - 1 restore_all 0.0667 - 1 number 0.0020 - 1 net_bh 0.0021 - 1 neigh_connected_output 0.0076 - 1 MD5Final 0.0083 - 1 kmem_cache_free 0.0016 - 1 kmem_cache_alloc 0.0022 - 1 __kfree_skb 0.0060 - 1 ipsec_rcv 0.0001 - 1 ip_rcv 0.0014 - 1 ip_options_fragment 0.0071 - 1 ip_local_deliver 0.0023 - 1 ipfw_forward_check 0.0139 - 1 ip_forward 0.0011 - 1 eth_header 0.0040 - 1 .des_encrypt3_end 0.0833 - 1 des_decrypt3 0.0034 - 1 csum_partial_copy_generic 0.0045 - 1 call_out_firewall 0.0125 - -Hope this data is helpful to someone... however the lack of visibility -into the decrypt side makes things less clear</pre> - -<h2><a name="speed.compress">Speed with compression</a></h2> - -<p>Another user reported some results for connections with and without IP -compression:</p> -<pre>Subject: [Users] Speed with compression - Date: Fri, 29 Jun 2001 - From: John McMonagle <johnm@advocap.org> - -Did a couple tests with compression using the new 1.91 freeswan. - -Running between 2 sites with cable modems. Both using approximately -130 mhz pentium. - -Transferred files with ncftp. - -Compressed file was a 6mb compressed installation file. -Non compressed was 18mb /var/lib/rpm/packages.rpm - - Compressed vpn regular vpn -Compress file 42.59 kBs 42.08 kBs -regular file 110.84 kBs 41.66 kBs - -Load was about 0 either way. -Ping times were very similar a bit above 9 ms. - -Compression looks attractive to me.</pre> -Later in the same thread, project technical lead Henry Spencer added: -<pre>> is there a reason not to switch compression on? I have large gateway boxes -> connecting 3 connections, one of them with a measly DS1 link... - -Run some timing tests with and without, with data and loads representative -of what you expect in production. That's the definitive way to decide. -If compression is a net loss, then obviously, leave it turned off. If it -doesn't make much difference, leave it off for simplicity and hence -robustness. If there's a substantial gain, by all means turn it on. - -If both ends support compression and can successfully negotiate a -compressed connection (trivially true if both are FreeS/WAN 1.91), then -the crucial question is CPU cycles. - -Compression has some overhead, so one question is whether *your* data -compresses well enough to save you more CPU cycles (by reducing the volume -of data going through CPU-intensive encryption/decryption) than it costs -you. Last time I ran such tests on data that was reasonably compressible -but not deliberately contrived to be so, this generally was not true -- -compression cost extra CPU cycles -- so compression was worthwhile only if -the link, not the CPU, was the bottleneck. However, that was before the -slow-compression bug was fixed. I haven't had a chance to re-run those -tests yet, but it sounds like I'd probably see a different result. </pre> -The bug he refers to was a problem with the compression libraries that had us -using C code, rather than assembler, for compression. It was fixed before -1.91. - -<h2><a name="methods">Methods of measuring</a></h2> - -<p>If you want to measure the loads FreeS/WAN puts on a system, note that -tools such as top or measurements such as load average are more-or-less -useless for this. They are not designed to measure something that does most -of its work inside the kernel.</p> - -<p>Here is a message from FreeS/WAN kernel programmer Richard Guy Briggs on -this:</p> -<pre>> I have a batch of boxes doing Freeswan stuff. -> I want to measure the CPU loading of the Freeswan tunnels, but am -> having trouble seeing how I get some figures out... -> -> - Keying etc is in userspace so will show up on the per-process -> and load average etc (ie pluto's load) - -Correct. - -> - KLIPS is in the kernel space, and does not show up in load average -> I think also that the KLIPS per-packet processing stuff is running -> as part of an interrupt handler so it does not show up in the -> /proc/stat system_cpu or even idle_cpu figures - -It is not running in interrupt handler. It is in the bottom half. -This is somewhere between user context (careful, this is not -userspace!) and hardware interrupt context. - -> Is this correct, and is there any means of instrumenting how much the -> cpu is being loaded - I don't like the idea of a system running out of -> steam whilst still showing 100% idle CPU :-) - -vmstat seems to do a fairly good job, but use a running tally to get a -good idea. A one-off call to vmstat gives different numbers than a -running stat. To do this, put an interval on your vmstat command -line.</pre> -and another suggestion from the same thread: -<pre>Subject: Re: Measuring the CPU usage of Freeswan - Date: Mon, 29 Jan 2001 - From: Patrick Michael Kane <modus@pr.es.to> - -The only truly accurate way to accurately track FreeSWAN CPU usage is to use -a CPU soaker. You run it on an unloaded system as a benchmark, then start up -FreeSWAN and take the difference to determine how much FreeSWAN is eating. -I believe someone has done this in the past, so you may find something in -the FreeSWAN archives. If not, someone recently posted a URL to a CPU -soaker benchmark tool on linux-kernel.</pre> -</body> -</html> diff --git a/doc/src/policy-groups-table.html b/doc/src/policy-groups-table.html deleted file mode 100644 index 8e84809cf..000000000 --- a/doc/src/policy-groups-table.html +++ /dev/null @@ -1,297 +0,0 @@ -<!DOCTYPE html PUBLIC "-//w3c//dtd html 4.0 transitional//en"> -<html> -<head> - - <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> - - <meta name="Author" content="Richard Guy Briggs"> - - <meta name="GENERATOR" content="Mozilla/4.78 [en] (X11; U; Linux 2.4.18 i686) [Netscape]"> - <title></title> -</head> - <body> -Policy Groups Table<br> -<br> -This table lists all the policy group combinations and expected packet flows.<br> -<br> -<br> - -<table border="1" cols="14" width="100%" nosave=""> - <tbody> - <tr> - <th bgcolor="#cccccc">policy</th> - <th bgcolor="#cccccc"><br> - </th> - <th bgcolor="#cccccc" colspan="2">none</th> - <th bgcolor="#cccccc" colspan="2">clear</th> - <th bgcolor="#cccccc" colspan="2">clear-or-private</th> - <th bgcolor="#cccccc" colspan="2">private-or-clear</th> - <th bgcolor="#cccccc" colspan="2">private</th> - <th bgcolor="#cccccc" colspan="2">block</th> - </tr> - <tr> - <th bgcolor="#cccccc"><br> - </th> - <th bgcolor="#cccccc">key?</th> - <th bgcolor="#cccccc">no</th> - <th bgcolor="#cccccc">yes</th> - <th bgcolor="#cccccc">no</th> - <th bgcolor="#cccccc">yes</th> - <th bgcolor="#cccccc">no</th> - <th bgcolor="#cccccc">yes</th> - <th bgcolor="#cccccc">no</th> - <th bgcolor="#cccccc">yes</th> - <th bgcolor="#cccccc">no</th> - <th bgcolor="#cccccc">yes</th> - <th bgcolor="#cccccc">no</th> - <th bgcolor="#cccccc">yes</th> - </tr> - <tr> - <th bgcolor="#cccccc" rowspan="2">none</th> - <th bgcolor="#cccccc">no</th> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c,f</td> - <td>c,f</td> - <td>c,f</td> - <td>c,f</td> - </tr> - <tr> - <th bgcolor="#cccccc">yes</th> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c,f?</td> - <td>c,f?</td> - <td>c,f</td> - <td>c,f</td> - <td>c,f</td> - <td>c,f</td> - </tr> - <tr> - <th bgcolor="#cccccc" rowspan="2">clear</th> - <th bgcolor="#cccccc">no</th> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c,c(f?)</td> - <td>c,f</td> - <td>c,f</td> - <td>c,f</td> - <td>c,f</td> - </tr> - <tr> - <th bgcolor="#cccccc">yes</th> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c,f?</td> - <td>c,f?</td> - <td>c,f</td> - <td>c,f</td> - <td>c,f</td> - <td>c,f</td> - </tr> - <tr> - <th bgcolor="#cccccc" rowspan="2">clear-or-private</th> - <th bgcolor="#cccccc">no</th> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c,f?</td> - <td>c,c(f?)</td> - <td>c,f</td> - <td>c,f</td> - <td>c,f</td> - <td>c,f</td> - </tr> - <tr> - <th bgcolor="#cccccc">yes</th> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c</td> - <td>c,f?</td> - <td>c,e</td> - <td>c,f</td> - <td>c,e</td> - <td>c,f</td> - <td>c,f</td> - </tr> - <tr> - <th bgcolor="#cccccc" rowspan="2">private-or-clear</th> - <th bgcolor="#cccccc">no</th> - <td>t,c</td> - <td>t,f?</td> - <td>t,c</td> - <td>t,f?</td> - <td>t,c</td> - <td>t,f?</td> - <td>t,f?</td> - <td>t,f?</td> - <td>t,f</td> - <td>t,f</td> - <td>t,f</td> - <td>t,f</td> - </tr> - <tr> - <th bgcolor="#cccccc">yes</th> - <td>t,c</td> - <td>t,f?</td> - <td>t,c</td> - <td>t,f?</td> - <td>t,c</td> - <td>t,e</td> - <td>t,c(f?)</td> - <td>t,e</td> - <td>t,f</td> - <td>t,e</td> - <td>t,f</td> - <td>t,f</td> - </tr> - <tr> - <th bgcolor="#cccccc" rowspan="2">private</th> - <th bgcolor="#cccccc">no</th> - <td>t,f</td> - <td>t,f</td> - <td>t,f</td> - <td>t,f</td> - <td>t,f</td> - <td>t,f</td> - <td>t,f</td> - <td>t,f</td> - <td>t,f</td> - <td>t,f</td> - <td>t,f</td> - <td>t,f</td> - </tr> - <tr> - <th bgcolor="#cccccc">yes</th> - <td>t,f</td> - <td>t,f</td> - <td>t,f</td> - <td>t,f</td> - <td>t,f</td> - <td>t,e</td> - <td>t,f</td> - <td>t,e</td> - <td>t,f</td> - <td>t,e</td> - <td>t,f</td> - <td>t,f</td> - </tr> - <tr> - <th bgcolor="#cccccc" rowspan="2">block</th> - <th bgcolor="#cccccc">no</th> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - </tr> - <tr> - <th bgcolor="#cccccc">yes</th> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - <td>f</td> - </tr> - - </tbody> -</table> - <br> - -<table border="1" cols="2" nosave=""> - <tbody> - <tr nosave=""> - <th nosave="">legend</th> - <th>packet fate</th> - </tr> - <tr> - <td>c</td> - <td>clear</td> - </tr> - <tr> - <td>f</td> - <td>fail</td> - </tr> - <tr> - <td>e</td> - <td>encrypt</td> - </tr> - <tr> - <td>t</td> - <td>trap</td> - </tr> - <tr> - <td valign="Top">c,f<br> - </td> - <td valign="Top">first packet clear, then fail<br> - </td> - </tr> - <tr> - <td valign="Top">c,e<br> - </td> - <td valign="Top">first packet clear, then encrypt<br> - </td> - </tr> - <tr> - <td valign="Top">t,f<br> - </td> - <td valign="Top">trap, then fail<br> - </td> - </tr> - <tr> - <td valign="Top">t,c<br> - </td> - <td valign="Top">trap, then clear<br> - </td> - </tr> - <tr> - <td valign="Top">t,e<br> - </td> - <td valign="Top">trap, then encrypt<br> - </td> - </tr> - - </tbody> -</table> - -</body> -</html> diff --git a/doc/src/policygroups.html b/doc/src/policygroups.html deleted file mode 100644 index 0425ade39..000000000 --- a/doc/src/policygroups.html +++ /dev/null @@ -1,489 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>Configuring FreeS/WAN with policy groups</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, encryption, cryptography, FreeS/WAN, FreeSWAN"> - <!-- - - Written by Claudia Schmeing for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: policygroups.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1>How to Configure Linux FreeS/WAN with Policy Groups</h1> - - -<A NAME="policygroups"></A> - -<H2>What are Policy Groups?</H2> - - -<P><STRONG>Policy Groups</STRONG> are an elegant general mechanism -to configure FreeS/WAN. They are useful for -many FreeS/WAN users.</P> - -<P>In previous FreeS/WAN versions, you needed to configure each IPsec -connection explicitly, on both local and remote hosts. - This could become complex.</P> - -<P>By contrast, Policy Groups allow you to set local IPsec policy -for lists of remote hosts and networks, -simply by listing the hosts and networks which you wish to -have special treatment in one of several Policy Group files. -FreeS/WAN then internally creates the connections -needed to implement each policy.</P> - -<P>In the next section we describe our five Base Policy Groups, which -you can use to configure IPsec in many useful ways. Later, we will -show you how to create an IPsec VPN using one line of configuration for -each remote host or network.</P> - - -<A NAME="builtin_policygroups"></A><H3>Built-In Security Options</H3> - -<P>FreeS/WAN offers these Base Policy Groups:</P> - -<DL> - -<DT>private</DT> - -<DD> -FreeS/WAN only communicates privately with the listed -<A HREF="glossary.html#CIDR">CIDR</A> blocks. -If needed, FreeS/WAN attempts to create a connection opportunistically. -If this fails, FreeS/WAN blocks communication. -Inbound blocking is assumed to be done by the firewall. FreeS/WAN offers -firewall hooks but no modern firewall rules to help with inbound blocking. - -</DD> - -<DT>private-or-clear</DT> -<DD> - -FreeS/WAN prefers private communication with the listed CIDR blocks. -If needed, FreeS/WAN attempts to create a connection opportunistically. -If this fails, FreeS/WAN allows traffic in the clear. - -</DD> - -<DT>clear-or-private</DT> - -<DD> -FreeS/WAN communicates cleartext with the listed CIDR blocks, but -also accepts inbound OE connection requests from them. -Also known as <A HREF="glossary.html#passive.OE">passive OE (pOE)</A>, -this policy may be used to create an -<A HREF="glossary.html#responder">opportunistic responder</A>. -</DD> - -<DT>clear</DT> -<DD> -FreeS/WAN only communicates cleartext with the listed CIDR blocks. -</DD> - -<DT>block</DT> -<DD>FreeS/WAN blocks traffic to and from and the listed CIDR blocks. -Inbound blocking is assumed to be done by the firewall. FreeS/WAN offers -firewall hooks but no modern firewall rules to help with inbound blocking. -<!-- also called "blockdrop".--> - -</DD> - -</DL> - -<A NAME="policy.group.notes"></A><P>Notes:</P> - -<UL> -<LI>Base Policy Groups apply to communication with this host only.</LI> -<LI>The most specific rule (whether policy or pre-configured connection) -applies. -This has several practical applications: -<UL> -<LI>If CIDR blocks overlap, FreeS/WAN chooses -the most specific applicable block.</LI> -<LI>This decision also takes into account any pre-configured connections -you may have.</LI> -<LI>If the most specific connection is a pre-configured connection, -the following procedure applies. If that connection is up, it will be -used. If it is routed, it will be brought up. If it is added, -no action will be taken.</LI> -</UL> -<LI>Base Policy Groups are created using built-in connections. -Details in -<A HREF="manpage.d/ipsec.conf.5.html">man ipsec.conf</A>.</LI> -<LI>All Policy Groups are bidirectional. -<A HREF="src/policy-groups-table.html">This chart</A> shows some technical -details. -FreeS/WAN does not support one-way encryption, since it can give users -a false sense of security.</LI> -</UL> - - -<H2>Using Policy Groups</H2> - -<P>The Base Policy Groups which build IPsec connections rely on Opportunistic -Encryption. To use the following examples, you -must first become OE-capable, as described -in our <A HREF="quickstart.html#quickstart">quickstart guide</A>. - -<A NAME="example1"></A><H3>Example 1: Using a Base Policy Group</H3> - -<P>Simply place CIDR blocks (<A HREF="#dnswarning">names</A>, -IPs or IP ranges) in /etc/ipsec.d/policies/<VAR>[groupname]</VAR>, -and reread the policy group files.</P> - -<P>For example, the <VAR>private-or-clear</VAR> policy tells -FreeS/WAN to prefer encrypted communication to the listed CIDR blocks. -Failing that, it allows talk in the clear.</P> - -<P>To make this your default policy, place -<A HREF="glossary.html#fullnet">fullnet</A> -in the <VAR>private-or-clear</VAR> policy group file:</P> - -<PRE> [root@xy root]# cat /etc/ipsec.d/policies/private-or-clear - # This file defines the set of CIDRs (network/mask-length) to which - # communication should be private, if possible, but in the clear otherwise. - .... - 0.0.0.0/0</PRE> - -<P>and reload your policies with</P> - -<PRE> ipsec auto --rereadgroups</PRE> - -<P>Use <A HREF="quickstart.html#opp.test">this test</A> to verify -opportunistic connections.</P> - - - -<A NAME="example2"></A><H3>Example 2: Defining IPsec Security Policy -with Groups</H3> - -<P>Defining IPsec security policy with Base Policy Groups is like creating -a shopping list: just put CIDR blocks in the appropriate group files. -For example:</P> - - -<PRE> [root@xy root]# cd /etc/ipsec.d/policies - [root@xy policies]# cat private - 192.0.2.96/27 # The finance department - 192.0.2.192/29 # HR - 192.0.2.12 # HR gateway - irc.private.example.com # Private IRC server - - [root@xy policies]# cat private-or-clear - 0.0.0.0/0 # My default policy: try to encrypt. - - [root@xy policies]# cat clear - 192.0.2.18/32 # My POP3 server - 192.0.2.19/32 # My Web proxy - - [root@xy policies]# cat block - spamsource.example.com</PRE> - -<P>To make these settings take effect, type:</P> -<PRE> ipsec auto --rereadgroups</PRE> - - -<P>Notes:</P> -<UL> -<LI>For opportunistic connection attempts to succeed, all participating -FreeS/WAN hosts and gateways must be configured for OE.</LI> -<LI>Examples 3 through 5 show how to implement a detailed <VAR>private</VAR> -policy.</LI> -<LI> -<A NAME="dnswarning"></A> -<FONT COLOR=RED>Warning:</FONT> Using DNS names in policy files and ipsec.conf -can be tricky. If the name does not resolve, the policy will not be -implemented for that name. -It is therefore safer either to use IPs, or to put any critical names -in /etc/hosts. -We plan to implement periodic DNS retry to help with this. -<BR> -Names are resolved at FreeS/WAN startup, or when the policies are reloaded. -Unfortunately, name lookup can hold up the startup process. -If you have fast DNS servers, the problem may be less severe. -</LI> -</UL> - - -<A HREF="example3"></A><H3>Example 3: Creating a Simple IPsec VPN with the -<VAR>private</VAR> Group</H3> - - -<P>You can create an IPsec VPN between several hosts, with -only one line of configuration per host, using the <VAR>private</VAR> -policy group.</P> - -<P>First, use our <A HREF="quickstart.html">quickstart -guide</A> to set up each participating host -with a FreeS/WAN install and OE.</P> - -<P>In one host's <VAR>/etc/ipsec.d/policies/private</VAR>, -list the peers to which you wish to protect traffic. -For example:</P> - -<PRE> [root@xy root]# cd /etc/ipsec.d/policies - [root@xy policies]# cat private - 192.0.2.9 # several hosts at example.com - 192.0.2.11 - 192.0.2.12 - irc.private.example.com -</PRE> - -<P>Copy the <VAR>private</VAR> file to each host. Remove the local host, and -add the initial host.</P> - -<PRE> scp2 /etc/ipsec.d/policies/private root@192.0.2.12:/etc/ipsec.d/policies/private</PRE> - -<P>On each host, reread the policy groups with</P> - -<PRE> ipsec auto --rereadgroups</PRE> - - -<P>That's it! You're configured.</P> - -<P>Test by pinging between two hosts. After a second or two, -traffic should flow, and</P> - -<PRE> ipsec eroute</PRE> - -<P>should yield something like</P> - -<PRE> 192.0.2.11/32 -> 192.0.2.8/32 => tun0x149f@192.0.2.8</PRE> - -<P>where your host IPs are substituted for 192.0.2.11 and 192.0.2.8.</P> - -<P>If traffic does not flow, there may be an error in your OE setup. -Revisit our <A HREF="quickstart.html">quickstart guide</A>.</P> - - -<P>Our next two examples show you how to add subnets to this IPsec VPN.</P> - - -<A NAME="example4"></A><H3>Example 4: New Policy Groups to Protect a -Subnet</H3> - -<P>To protect traffic to a subnet behind your FreeS/WAN gateway, -you'll need additional DNS records, and new policy groups. -To set up the DNS, see our <A HREF="quickstart.html#opp.gate">quickstart -guide</A>. To create five new policy groups for your subnet, -copy these connections to <VAR>/etc/ipsec.conf</VAR>. -Substitute your subnet's IPs for 192.0.2.128/29.</P> - -<PRE> -conn private-net - also=private # inherits settings (eg. auto=start) from built in conn - leftsubnet=192.0.2.128/29 # your subnet's IPs here - -conn private-or-clear-net - also=private-or-clear - leftsubnet=192.0.2.128/29 - -conn clear-or-private-net - also=clear-or-private - leftsubnet=192.0.2.128/29 - -conn clear-net - also=clear - leftsubnet=192.0.2.128/29 - -conn block-net - also=block - leftsubnet=192.0.2.128/29 -</PRE> - -<P>Copy the gateway's files to serve as the initial policy group files for the -new groups:</P> - -<PRE> - cp -p /etc/ipsec.d/policies/private /etc/ipsec.d/policies/private-net - cp -p /etc/ipsec.d/policies/private-or-clear /etc/ipsec.d/policies/private-or-clear-net - cp -p /etc/ipsec.d/policies/clear-or-private /etc/ipsec.d/policies/clear-or-private-net - cp -p /etc/ipsec.d/policies/clear /etc/ipsec.d/policies/clear-net - cp -p /etc/ipsec.d/policies/block /etc/ipsec.d/policies/block -</PRE> - -<P><STRONG>Tip: Since a missing policy group file is equivalent to a file with -no entries, you need only create files for the connections -you'll use.</STRONG></P> - -<P>To test one of your new groups, place the fullnet 0.0.0.0/0 in -<VAR>private-or-clear-net</VAR>. -Perform the subnet test in -<A HREF="quickstart.html#opp.test">our quickstart guide</A>. You should -see a connection, and</P> - -<PRE> ipsec eroute</PRE> - -<P>should include an entry which mentions the subnet node's IP and the -OE test site IP, like this:</P> - -<PRE> 192.0.2.131/32 -> 192.139.46.77/32 => tun0x149f@192.0.2.11</PRE> - - -<A HREF="example5"></A><H3>Example 5: Adding a Subnet to the VPN</H3> - -<P>Suppose you wish to secure traffic to a subnet 192.0.2.192/29 -behind a FreeS/WAN box 192.0.2.12.</P> - -<P>First, add DNS entries to configure 192.0.2.12 as an opportunistic -gateway for that subnet. Instructions are in - our <A HREF="quickstart.html#opp.gate">quickstart guide</A>. -Next, create a <VAR>private-net</VAR> group on 192.0.2.12 as described in -<A HREF="#example4">Example 4</A>. -</P> - -<P>On each other host, add the subnet 192.0.2.192/29 to <VAR>private</VAR>, -yielding for example</P> - -<PRE> [root@xy root]# cd /etc/ipsec.d/policies - [root@xy policies]# cat private - 192.0.2.9 # several hosts at example.com - 192.0.2.11 - 192.0.2.12 # HR department gateway - 192.0.2.192/29 # HR subnet - irc.private.example.com -</PRE> - - -<P>and reread policy groups with </P> - -<PRE> ipsec auto --rereadgroups</PRE> - -<P>That's all the configuration you need.</P> - -<P>Test your VPN by pinging from a machine on 192.0.2.192/29 to any other host: -</P> - -<PRE> [root@192.0.2.194]# ping 192.0.2.11</PRE> - - -<P>After a second or two, traffic should flow, and</P> - -<PRE> ipsec eroute</PRE> - -<P>should yield something like</P> - -<PRE> 192.0.2.11/32 -> 192.0.2.194/32 => tun0x149f@192.0.2.12 -</PRE> - -<P>Key:</P> -<TABLE> -<TR><TD>1.</TD> - <TD>192.0.2.11/32</TD> - <TD>Local start point of the protected traffic. - </TD></TR> -<TR><TD>2.</TD> - <TD>192.0.2.194/32</TD> - <TD>Remote end point of the protected traffic. - </TD></TR> -<TR><TD>3.</TD> - <TD>192.0.2.12</TD> - <TD>Remote FreeS/WAN node (gateway or host). - May be the same as (2). - </TD></TR> -<TR><TD>4.</TD> - <TD>[not shown]</TD> - <TD>Local FreeS/WAN node (gateway or host), - where you've produced the output. - May be the same as (1). - </TD></TR> -</TABLE> - -<P>For additional assurance, you can verify with a packet sniffer -that the traffic is being encrypted.</P> - - -<P>Note</P> -<UL> -<LI>Because strangers may also connect via OE, -this type of VPN may require a stricter firewalling policy than a -conventional VPN.</LI></UL> - - - -<H2>Appendix</H2> - -<A NAME="hiddenconn"></A><H3>Our Hidden Connections</H3> - - -<P>Our Base Policy Groups are created using hidden connections. -These are spelled out in -<A HREF="manpage.d/ipsec.conf.5.html">man ipsec.conf</A> - and defined in <VAR>/usr/local/lib/ipsec/_confread</VAR>. -</P> - - -<A NAME="custom_policygroups"></A><H3>Custom Policy Groups</H3> - -<P>A policy group is built using a special connection description -in <VAR>ipsec.conf</VAR>, which:</P> - -<UL> -<LI>is <STRONG>generic</STRONG>. It uses -<VAR>right=[%group|%opportunisticgroup]</VAR> rather than specific IPs. -The connection is cloned for every name or IP range listed in its Policy Group -file.</LI> -<LI>often has a <STRONG>failure rule</STRONG>. This rule, written -<VAR>failureshunt=[passthrough|drop|reject|none]</VAR>, tells FreeS/WAN -what to do with packets for these CIDRs if it fails to establish the connection. -Default is <VAR>none</VAR>. -</LI> -</UL> - -<P>To create a new group:</P> -<OL> -<LI>Create its connection definition in <VAR>ipsec.conf</VAR>.</LI> -<LI>Create a Policy Group file in <VAR>/etc/ipsec.d/policies</VAR> -with the same name as your connection. -</LI> -<LI>Put a CIDR block in that file.</LI> -<LI>Reread groups with <VAR>ipsec auto --rereadgroups</VAR>.</LI> -<LI>Test: <VAR>ping</VAR> to activate any OE connection, and view -results with <VAR>ipsec eroute</VAR>.</LI> -</OL> - -<A NAME="disable_oe"></A> -<A NAME="disable_policygroups"></A><H3>Disabling Opportunistic Encryption</H3> - -<P>To disable OE (eg. policy groups and packetdefault), cut and paste the following lines -to <VAR>/etc/ipsec.conf</VAR>:</P> - -<PRE>conn block - auto=ignore - -conn private - auto=ignore - -conn private-or-clear - auto=ignore - -conn clear-or-private - auto=ignore - -conn clear - auto=ignore - -conn packetdefault - auto=ignore</PRE> - -<P>Restart FreeS/WAN so that the changes take effect:</P> - -<PRE> ipsec setup restart</PRE> - -</body> -</html> - - diff --git a/doc/src/politics.html b/doc/src/politics.html deleted file mode 100644 index 9e87d4f05..000000000 --- a/doc/src/politics.html +++ /dev/null @@ -1,1466 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>History and politics of cryptography</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, cryptography, history, politics"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: politics.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1><a name="politics">History and politics of cryptography</a></h1> - -<p>Cryptography has a long and interesting history, and has been the subject -of considerable political controversy.</p> - -<h2><a name="intro.politics">Introduction</a></h2> - -<h3>History</h3> - -<p>The classic book on the history of cryptography is David Kahn's <a -href="biblio.html#Kahn">The Codebreakers</a>. It traces codes and -codebreaking from ancient Egypt to the 20th century.</p> - -<p>Diffie and Landau <a href="biblio.html#diffie">Privacy on the Line: The -Politics of Wiretapping and Encryption</a> covers the history from the First -World War to the 1990s, with an emphasis on the US.</p> - -<h4>World War II</h4> - -<p>During the Second World War, the British "Ultra" project achieved one of -the greatest intelligence triumphs in the history of warfare, breaking many -Axis codes. One major target was the Enigma cipher machine, a German device -whose users were convinced it was unbreakable. The American "Magic" project -had some similar triumphs against Japanese codes.</p> - -<p>There are many books on this period. See our bibliography for several. Two -I particularly like are:</p> -<ul> - <li>Andrew Hodges has done a superb <a - href="http://www.turing.org.uk/book/">biography</a> of Alan Turing, a key - player among the Ultra codebreakers. Turing was also an important - computer pioneer. The terms <a - href="http://www.abelard.org/turpap/turpap.htm">Turing test</a> and <a - href="http://plato.stanford.edu/entries/turing-machine/">Turing - machine</a> are named for him, as is the <a - href="http://www.acm.org">ACM</a>'s highest technical <a - href="http://www.acm.org/awards/taward.html">award</a>.</li> - <li>Neal Stephenson's <a href="biblio.html#neal">Cryptonomicon</a> is a - novel with cryptography central to the plot. Parts of it take place - during WW II, other parts today.</li> -</ul> - -<p>Bletchley Park, where much of the Ultra work was done, now has a museum -and a <a href="http://www.bletchleypark.org.uk/">web site</a>.</p> - -<p>The Ultra work introduced three major innovations.</p> -<ul> - <li>The first break of Enigma was achieved by Polish Intelligence in 1931. - Until then most code-breakers had been linguists, but a different - approach was needed to break machine ciphers. Polish Intelligence - recruited bright young mathematicians to crack the "unbreakable" Enigma. - When war came in 1939, the Poles told their allies about this, putting - Britain on the road to Ultra. The British also adopted a mathematical - approach.</li> - <li>Machines were extensively used in the attacks. First the Polish "Bombe" - for attacking Enigma, then British versions of it, then machines such as - Collosus for attacking other codes. By the end of the war, some of these - machines were beginning to closely resemble digital computers. After the - war, a team at Manchester University, several old Ultra hands included, - built one of the world's first actual general-purpose digital - computers.</li> - <li>Ultra made codebreaking a large-scale enterprise, producing - intelligence on an industrial scale. This was not a "black chamber", not - a hidden room in some obscure government building with a small crew of - code-breakers. The whole operation -- from wholesale interception of - enemy communications by stations around the world, through large-scale - code-breaking and analysis of the decrypted material (with an enormous - set of files for cross-referencing), to delivery of intelligence to field - commanders -- was huge, and very carefully managed.</li> -</ul> - -<p>So by the end of the war, Allied code-breakers were expert at large-scale -mechanised code-breaking. The payoffs were enormous.</p> - -<h4><a name="postwar">Postwar and Cold War</a></h4> - -<p>The wartime innovations were enthusiastically adopted by post-war and Cold -War signals intelligence agencies. Presumably many nations now have some -agency capable of sophisticated attacks on communications security, and quite -a few engage in such activity on a large scale.</p> - -<p>America's <a href="glossary.html#NSA">NSA</a>, for example, is said to be -both the world's largest employer of mathematicians and the world's largest -purchaser of computer equipment. Such claims may be somewhat exaggerated, but -beyond doubt the NSA -- and similar agencies in other countries -- have some -excellent mathematicians, lots of powerful computers, sophisticated software, -and the organisation and funding to apply them on a large scale. Details of -the NSA budget are secret, but there are some published <a -href="http://www.fas.org/irp/nsa/nsabudget.html">estimates</a>.</p> - -<p>Changes in the world's communications systems since WW II have provided -these agencies with new targets. Cracking the codes used on an enemy's -military or diplomatic communications has been common practice for centuries. -Extensive use of radio in war made large-scale attacks such as Ultra -possible. Modern communications make it possible to go far beyond that. -Consider listening in on cell phones, or intercepting electronic mail, or -tapping into the huge volumes of data on new media such as fiber optics or -satellite links. None of these targets existed in 1950. All of them can be -attacked today, and almost certainly are being attacked.</p> - -<p>The Ultra story was not made public until the 1970s. Much of the recent -history of codes and code-breaking has not been made public, and some of it -may never be. Two important books are:</p> -<ul> - <li>Bamford's <a href="biblio.html#puzzle">The Puzzle Palace</a>, a history - of the NSA</li> - <li>Hager's <a href="http://www.fas.org/irp/eprint/sp/index.html">Secret - Power</a>, about the <a - href="http://sg.yahoo.com/government/intelligence/echelon_network/">Echelon</a> - system -- the US, UK, Canada, Australia and New Zealand co-operating to - monitor much of the world's communications.</li> -</ul> - -<p>Note that these books cover only part of what is actually going on, and -then only the activities of nations open and democratic enough that (some of) -what they are doing can be discovered. A full picture, including:</p> -<ul> - <li>actions of the English-speaking democracies not covered in those - books</li> - <li>actions of other more-or-less sane governments</li> - <li>the activities of various more-or-less insane governments</li> - <li>possibilities for unauthorized action by government employees</li> - <li>possible actions by large non-government organisations: corporations, - criminals, or conspiracies</li> -</ul> - -<p>might be really frightening.</p> - -<h4><a name="recent">Recent history -- the crypto wars</a></h4> - -<p>Until quite recently, cryptography was primarily a concern of governments, -especially of the military, of spies, and of diplomats. Much of it was -extremely secret.</p> - -<p>In recent years, that has changed a great deal. With computers and -networking becoming ubiquitous, cryptography is now important to almost -everyone. Among the developments since the 1970s:</p> -<ul> - <li>The US gov't established the Data Encryption Standard, <a - href="glossary.html#DES">DES</a>, a <a href="glossary.html#block">block - cipher</a> for cryptographic protection of unclassfied documents.</li> - <li>DES also became widely used in industry, especially regulated - industries such as banking.</li> - <li>Other nations produced their own standards, such as <a - href="glossary.html#GOST">GOST</a> in the Soviet Union.</li> - <li><a href="glossary.html#public">Public key</a> cryptography was invented - by Diffie and Hellman.</li> - <li>Academic conferences such as <a - href="http://www-cse.ucsd.edu/users/mihir/crypto2k.html">Crypto</a> and - <a - href="http://www.esat.kuleuven.ac.be/cosic/eurocrypt2000/">Eurocrypt</a> - began.</li> - <li>Several companies began offerring cryptographic products: <a - href="glossary.html#RSAco">RSA</a>, <a href="glossary.html#PGPI">PGP</a>, - the many vendors with <a href="glossary.html#PKI">PKI</a> products, - ...</li> - <li>Cryptography appeared in other products: operating systems, word - processors, ...</li> - <li>Network protocols based on crypto were developed: <a - href="glossary.html#SSH">SSH</a>, <a href="glossary.html#SSL">SSL</a>, <a - href="glossary.html#IPsec">IPsec</a>, ...</li> - <li>Crytography came into widespread use to secure bank cards, terminals, - ...</li> - <li>The US government replaced <a href="glossary.html#DES">DES</a> with the - much stronger Advanced Encryption Standard, <a - href="glossary.html#AES">AES</a></li> -</ul> - -<p>This has led to a complex ongoing battle between various mainly government -groups wanting to control the spread of crypto and various others, notably -the computer industry and the <a -href="http://online.offshore.com.ai/security/">cypherpunk</a> crypto -advocates, wanting to encourage widespread use.</p> - -<p>Steven Levy has written a fine history of much of this, called <a -href="biblio.html#crypto">Crypto: How the Code rebels Beat the Government -- -Saving Privacy in the Digital Age</a>.</p> - -<p>The FreeS/WAN project is to a large extent an outgrowth of cypherpunk -ideas. Our reasons for doing the project can be seen in these quotes from the -<a -href="http://www.eff.org/pub/Privacy/Crypto_misc/cypherpunk.manifesto">Cypherpunk -Manifesto</a>:</p> - -<blockquote> - Privacy is necessary for an open society in the electronic age. ... - - <p>We cannot expect governments, corporations, or other large, faceless - organizations to grant us privacy out of their beneficence. It is to their - advantage to speak of us, and we should expect that they will speak. - ...</p> - - <p>We must defend our own privacy if we expect to have any. ...</p> - - <p>Cypherpunks write code. We know that someone has to write software to - defend privacy, and since we can't get privacy unless we all do, we're - going to write it. We publish our code so that our fellow Cypherpunks may - practice and play with it. Our code is free for all to use, worldwide. We - don't much care if you don't approve of the software we write. We know - that software can't be destroyed and that a widely dispersed system can't - be shut down.</p> - - <p>Cypherpunks deplore regulations on cryptography, for encryption is - fundamentally a private act. ...</p> - - <p>For privacy to be widespread it must be part of a social contract. - People must come and together deploy these systems for the common good. - ...</p> -</blockquote> - -<p>To quote project leader John Gilmore:</p> - -<blockquote> - We are literally in a race between our ability to build and deploy - technology, and their ability to build and deploy laws and treaties. - Neither side is likely to back down or wise up until it has definitively - lost the race.</blockquote> - -<p>If FreeS/WAN reaches its goal of making <a -href="intro.html#opp.intro">opportunistic encryption</a> widespread so that -secure communication can become the default for a large part of the net, we -will have struck a major blow.</p> - -<h3><a name="intro.poli">Politics</a></h3> - -<p>The political problem is that nearly all governments want to monitor their -enemies' communications, and some want to monitor their citizens. They may be -very interested in protecting some of their own communications, and often -some types of business communication, but not in having everyone able to -communicate securely. They therefore attempt to restrict availability of -strong cryptography as much as possible.</p> - -<p>Things various governments have tried or are trying include:</p> -<ul> - <li>Echelon, a monitor-the-world project of the US, UK, NZ, Australian and - Canadian <a href="glossary.html#SIGINT">signals intelligence</a> - agencies. See this <a - href="http://sg.yahoo.com/government/intelligence/echelon_network/">collection</a> - of links and this <a - href="http://www.zdnet.com/zdnn/stories/news/0,4586,2640682,00.html">story</a> - on the French Parliament's reaction.</li> - <li>Others governments may well have their own Echelon-like projects. To - quote the Dutch Minister of Defense, as reported in a German <a - href="http://www.heise.de/tp/english/inhalt/te/4729/1.html">magazine</a>: - - <blockquote> - The government believes not only the governments associated with - Echelon are able to intercept communication systems, but that it is an - activity of the investigative authorities and intelligence services of - many countries with governments of different political - signature.</blockquote> - Even if they have nothing on the scale of Echelon, most intelligence - agencies and police forces certainly have some interception - capability.</li> - <li><a href="glossary.html#NSA">NSA</a> tapping of submarine communication - cables, described in <a - href="http://www.zdnet.com/zdnn/stories/news/0,4586,2764372,00.html">this - article</a></li> - <li>A proposal for international co-operation on <a - href="http://www.heise.de/tp/english/special/enfo/4306/1.html">Internet - surveillance</a>.</li> - <li>Alleged <a href="http://cryptome.org/nsa-sabotage.htm">sabotage</a> of - security products by the <a href="glossary.html#NSA">NSA</a> (the US - signals intelligence agency).</li> - <li>The German armed forces and some government departments will stop using - American software for fear of NSA "back doors", according to this <a - href="http://www.theregister.co.uk/content/4/17679.html">news - story</a>.</li> - <li>The British Regulation of Investigatory Powers bill. See this <a - href="http://www.fipr.org/rip/index.html">web page.</a> and perhaps this - <a - href="http://ars.userfriendly.org/cartoons/?id=20000806&mode=classic">cartoon</a>.</li> - <li>A Russian <a - href="http://www.eff.org/pub/Privacy/Foreign_and_local/Russia/russian_crypto_ban_english.edict">ban</a> - on cryptography</li> - <li>Chinese <a - href="http://www.eff.org/pub/Misc/Publications/Declan_McCullagh/www/global/china">controls</a> - on net use.</li> - <li>The FBI's carnivore system for covert searches of email. See this <a - href="http://www.zdnet.com/zdnn/stories/news/0,4586,2601502,00.html">news - coverage</a> and this <a - href="http://www.crypto.com/papers/carnivore-risks.html">risk - assessment</a>. The government had an external review of some aspects of - this system done. See this <a - href="http://www.crypto.com/papers/carnivore_report_comments.html">analysis</a> - of that review. Possible defenses against Carnivore include: - <ul> - <li><a href="glossary.html#PGP">PGP</a> for end-to-end mail - encryption</li> - <li><a href="http://www.home.aone.net.au/qualcomm/">secure sendmail</a> - for server-to-server encryption</li> - <li>IPsec encryption on the underlying IP network</li> - </ul> - </li> - <li>export laws restricting strong cryptography as a munition. See <a - href="#exlaw">discussion</a> below.</li> - <li>various attempts to convince people that fundamentally flawed - cryptography, such as encryption with a <a href="#escrow">back door</a> - for government access to data or with <a href="#shortkeys">inadequate key - lengths</a>, was adequate for their needs.</li> -</ul> - -<p>Of course governments are by no means the only threat to privacy and -security on the net. Other threats include:</p> -<ul> - <li>industrial espionage, as for example in this <a - href="http://www.zdnet.com/zdnn/stories/news/0,4586,2626931,00.html">news - story</a></li> - <li>attacks by organised criminals, as in this <a - href="http://www.sans.org/newlook/alerts/NTE-bank.htm">large-scale - attack</a></li> - <li>collection of personal data by various companies. - <ul> - <li>for example, consider the various corporate winners of Privacy - International's <a - href="http://www.privacyinternational.org/bigbrother/">Big Brother - Awards</a>.</li> - <li><a href="http://www.zeroknowledge.com">Zero Knowledge</a> sell - tools to defend against this</li> - </ul> - </li> - <li>individuals may also be a threat in a variety of ways and for a variety - of reasons</li> - <li>in particular, an individual with access to government or industry data - collections could do considerable damage using that data in unauthorized - ways.</li> -</ul> - -<p>One <a -href="http://www.zdnet.com/zdnn/stories/news/0,4586,2640674,00.html">study</a> -enumerates threats and possible responses for small and medium businesses. -VPNs are a key part of the suggested strategy.</p> - -<p>We consider privacy a human right. See the UN's <a href="http://www.un.org/Overview/rights.html">Universal -Declaration of Human Rights</a>, article twelve:</p> - -<blockquote> - No one shall be subjected to arbitrary interference with his privacy, - family, home or correspondence, nor to attacks upon his honor and - reputation. Everyone has the right to the protection of the law against - such interference or attacks.</blockquote> - -<p>Our objective is to help make privacy possible on the Internet using -cryptography strong enough not even those well-funded government agencies are -likely to break it. If we can do that, the chances of anyone else breaking it -are negliible.</p> - -<h3>Links</h3> - -<p>Many groups are working in different ways to defend privacy on the net and -elsewhere. Please consider contributing to one or more of these groups:</p> -<ul> - <li>the EFF's <a href="http://www.eff.org/crypto/">Privacy Now!</a> - campaign</li> - <li>the <a href="http://www.gilc.org">Global Internet Liberty - Campaign</a></li> - <li><a href="http://www.cpsr.org/program/privacy/privacy.html">Computer - Professionals for Social Responsibility</a></li> -</ul> - -<p>For more on these issues see:</p> -<ul> - <li>Steven Levy (Newsweek's chief technology writer and author of the - classic "Hackers") new book <a href="biblio.html#crypto">Crypto: How the - Code Rebels Beat the Government--Saving Privacy in the Digital - Age</a></li> - <li>Simson Garfinkel (Boston Globe columnist and author of books on <a - href="biblio.html#PGP">PGP</a> and <a href="biblio.html#practical">Unix - Security</a>) book <a href="biblio.html#Garfinkel">Database Nation: the - death of privacy in the 21st century</a></li> -</ul> - -<p>There are several collections of <a href="web.html#quotes">crypto -quotes</a> on the net.</p> - -<p>See also the <a href="biblio.html">bibliography</a> and our list of <a -href="web.html#policy">web references</a> on cryptography law and policy.</p> - -<h3>Outline of this section</h3> - -<p>The remainder of this section includes two pieces of writing by our -project leader</p> -<ul> - <li>his <a href="#gilmore">rationale</a> for starting this</li> - <li>another <a href="#policestate">discussion</a> of project goals</li> -</ul> - -<p>and discussions of:</p> -<ul> - <li><a href="#desnotsecure">why we do not use DES</a></li> - <li><a href="#exlaw">cryptography export laws</a></li> - <li>why <a href="#escrow">government access to keys</a> is not a good - idea</li> - <li>the myth that <a href="#shortkeys">short keys</a> are adequate for some - security requirements</li> -</ul> - -<p>and a section on <a href="#press">press coverage of FreeS/WAN</a>.</p> - -<h2><a name="leader">From our project leader</a></h2> - -<p>FreeS/WAN project founder John Gilmore wrote a web page about why we are -doing this. The version below is slightly edited, to fit this format and to -update some links. For a version without these edits, see his <a -href="http://www.toad.com/gnu/">home page</a>.</p> - -<center> -<h3><a name="gilmore">Swan: Securing the Internet against Wiretapping</a></h3> -</center> - -<p>My project for 1996 was to <b>secure 5% of the Internet traffic against -passive wiretapping</b>. It didn't happen in 1996, so I'm still working on it -in 1997, 1998, and 1999! If we get 5% in 1999 or 2000, we can secure 20% the -next year, against both active and passive attacks; and 80% the following -year. Soon the whole Internet will be private and secure. The project is -called S/WAN or S/Wan or Swan for Secure Wide Area Network; since it's free -software, we call it FreeSwan to distinguish it from various commercial -implementations. <a href="http://www.rsa.com/rsa/SWAN/">RSA</a> came up with -the term "S/WAN". Our main web site is at <a -href="http://www.freeswan.org/">http://www.freeswan.org/</a>. Want to -help?</p> - -<p>The idea is to deploy PC-based boxes that will sit between your local area -network and the Internet (near your firewall or router) which -opportunistically encrypt your Internet packets. Whenever you talk to a -machine (like a Web site) that doesn't support encryption, your traffic goes -out "in the clear" as usual. Whenever you connect to a machine that does -support this kind of encryption, this box automatically encrypts all your -packets, and decrypts the ones that come in. In effect, each packet gets put -into an "envelope" on one side of the net, and removed from the envelope when -it reaches its destination. This works for all kinds of Internet traffic, -including Web access, Telnet, FTP, email, IRC, Usenet, etc.</p> - -<p>The encryption boxes are standard PC's that use freely available Linux -software that you can download over the Internet or install from a cheap -CDROM.</p> - -<p>This wasn't just my idea; lots of people have been working on it for -years. The encryption protocols for these boxes are called <a -href="glossary.html#IPsec">IPSEC (IP Security)</a>. They have been developed -by the <a -href="http://www.ietf.cnri.reston.va.us/html.charters/ipsec-charter.html">IP -Security Working Group</a> of the <a href="http://www.ietf.org/">Internet -Engineering Task Force</a>, and will be a standard part of the next major -version of the Internet protocols (<a -href="http://playground.sun.com/pub/ipng/html/ipng-main.html">IPv6</a>). For -today's (IP version 4) Internet, they are an option.</p> - -<p>The <a href="http://www.iab.org/iab">Internet Architecture Board</a> and -<a href="http://www.ietf.org/">Internet Engineering Steering Group</a> have -taken a <a href="iab-iesg.stmt">strong stand</a> that the Internet should use -powerful encryption to provide security and privacy. I think these protocols -are the best chance to do that, because they can be deployed very easily, -without changing your hardware or software or retraining your users. They -offer the best security we know how to build, using the Triple-DES, RSA, and -Diffie-Hellman algorithms.</p> - -<p>This "opportunistic encryption box" offers the "fax effect". As each -person installs one for their own use, it becomes more valuable for their -neighbors to install one too, because there's one more person to use it with. -The software automatically notices each newly installed box, and doesn't -require a network administrator to reconfigure it. Instead of "virtual -private networks" we have a "REAL private network"; we add privacy to the -real network instead of layering a manually-maintained virtual network on top -of an insecure Internet.</p> - -<h4>Deployment of IPSEC</h4> - -<p>The US government would like to control the deployment of IP Security with -its <a href="#exlaw">crypto export laws</a>. This isn't a problem for my -effort, because the cryptographic work is happening outside the United -States. A foreign philanthropist, and others, have donated the resources -required to add these protocols to the Linux operating system. <a -href="http://www.linux.org/">Linux</a> is a complete, freely available -operating system for IBM PC's and several kinds of workstation, which is -compatible with Unix. It was written by Linus Torvalds, and is still -maintained by a talented team of expert programmers working all over the -world and coordinating over the Internet. Linux is distributed under the <a -href="glossary.html#GPL">GNU Public License</a>, which gives everyone the -right to copy it, improve it, give it to their friends, sell it commercially, -or do just about anything else with it, without paying anyone for the -privilege.</p> - -<p>Organizations that want to secure their network will be able to put two -Ethernet cards into an IBM PC, install Linux on it from a $30 CDROM or by -downloading it over the net, and plug it in between their Ethernet and their -Internet link or firewall. That's all they'll have to do to encrypt their -Internet traffic everywhere outside their own local area network.</p> - -<p>Travelers will be able to run Linux on their laptops, to secure their -connection back to their home network (and to everywhere else that they -connect to, such as customer sites). Anyone who runs Linux on a standalone PC -will also be able to secure their network connections, without changing their -application software or how they operate their computer from day to day.</p> - -<p>There will also be numerous commercially available firewalls that use this -technology. <a href="http://www.rsa.com/">RSA Data Security</a> is -coordinating the <a href="http://www.rsa.com/rsa/SWAN">S/Wan (Secure Wide -Area Network)</a> project among more than a dozen vendors who use these -protocols. There's a <a -href="http://www.rsa.com/rsa/SWAN/swan_test.htm">compatability chart</a> that -shows which vendors have tested their boxes against which other vendors to -guarantee interoperatility.</p> - -<p>Eventually it will also move into the operating systems and networking -protocol stacks of major vendors. This will probably take longer, because -those vendors will have to figure out what they want to do about the export -controls.</p> - -<h4>Current status</h4> - -<p>My initial goal of securing 5% of the net by Christmas '96 was not met. It -was an ambitious goal, and inspired me and others to work hard, but was -ultimately too ambitious. The protocols were in an early stage of -development, and needed a lot more protocol design before they could be -implemented. As of April 1999, we have released version 1.0 of the software -(<a -href="ftp://ftp.xs4all.nl/freeswan/freeswan-1.0.tar.gz">freeswan-1.0.tar.gz</a>), -which is suitable for setting up Virtual Private Networks using shared -secrets for authentication. It does not yet do opportunistic encryption, or -use DNSSEC for authentication; those features are coming in a future -release.</p> -<dl> - <dt>Protocols</dt> - <dd>The low-level encrypted packet formats are defined. The system for - publishing keys and providing secure domain name service is defined. - The IP Security working group has settled on an NSA-sponsored protocol - for key agreement (called ISAKMP/Oakley), but it is still being worked - on, as the protocol and its documentation is too complex and - incomplete. There are prototype implementations of ISAKMP. The - protocol is not yet defined to enable opportunistic encryption or the - use of DNSSEC keys.</dd> - <dt>Linux Implementation</dt> - <dd>The Linux implementation has reached its first major release and is - ready for production use in manually-configured networks, using Linux - kernel version 2.0.36.</dd> - <dt>Domain Name System Security</dt> - <dd>There is now a release of BIND 8.2 that includes most DNS Security - features. - <p>The first prototype implementation of Domain Name System Security - was funded by <a href="glossary.html#DARPA">DARPA</a> as part of their - <a href="http://www.darpa.mil/ito/research/is/index.html">Information - Survivability program</a>. <a href="http://www.tis.com">Trusted - Information Systems</a> wrote a modified version of <a - href="http://www.isc.org/bind.html">BIND</a>, the widely-used Berkeley - implementation of the Domain Name System.</p> - <p>TIS, ISC, and I merged the prototype into the standard version of - BIND. The first production version that supports KEY and SIG records is - <b>bind-4.9.5</b>. This or any later version of BIND will do for - publishing keys. It is available from the <a - href="http://www.isc.org/bind.html">Internet Software Consortium</a>. - This version of BIND is not export-controlled since it does not contain - any cryptography. Later releases starting with BIND 8.2 include - cryptography for authenticating DNS records, which is also exportable. - Better documentation is needed.</p> - </dd> -</dl> - -<h4>Why?</h4> - -<p>Because I can. I have made enough money from several successful startup -companies, that for a while I don't have to work to support myself. I spend -my energies and money creating the kind of world that I'd like to live in and -that I'd like my (future) kids to live in. Keeping and improving on the civil -rights we have in the United States, as we move more of our lives into -cyberspace, is a particular goal of mine.</p> - -<h4>What You Can Do</h4> -<dl> - <dt>Install the latest BIND at your site.</dt> - <dd>You won't be able to publish any keys for your domain, until you have - upgraded your copy of BIND. The thing you really need from it is the - new version of <i>named</i>, the Name Daemon, which knows about the new - KEY and SIG record types. So, download it from the <a - href="http://www.isc.org/bind.html">Internet Software Consortium </a> - and install it on your name server machine (or get your system - administrator, or Internet Service Provider, to install it). Both your - primary DNS site and all of your secondary DNS sites will need the new - release before you will be able to publish your keys. You can tell - which sites this is by running the Unix command "dig MYDOMAIN ns" and - seeing which sites are mentioned in your NS (name server) records.</dd> - <dt>Set up a Linux system and run a 2.0.x kernel on it</dt> - <dd>Get a machine running Linux (say the 5.2 release from <a - href="http://www.redhat.com">Red Hat</a>). Give the machine two - Ethernet cards.</dd> - <dt>Install the Linux IPSEC (Freeswan) software</dt> - <dd>If you're an experienced sysadmin or Linux hacker, install the - freeswan-1.0 release, or any later release or snapshot. These releases - do NOT provide automated "opportunistic" operation; they must be - manually configured for each site you wish to encrypt with.</dd> - <dt>Get on the linux-ipsec mailing list</dt> - <dd>The discussion forum for people working on the project, and testing - the code and documentation, is: linux-ipsec@clinet.fi. To join this - mailing list, send email to <a - href="mailto:linux-ipsec-REQUEST@clinet.fi">linux-ipsec-REQUEST@clinet.fi</a> - containing a line of text that says "subscribe linux-ipsec". (You can - later get off the mailing list the same way -- just send "unsubscribe - linux-ipsec").</dd> - - <p></p> - <dt>Check back at this web page every once in a while</dt> - <dd>I update this page periodically, and there may be new information in - it that you haven't seen. My intent is to send email to the mailing - list when I update the page in any significant way, so subscribing to - the list is an alternative.</dd> -</dl> - -<p>Would you like to help? I can use people who are willing to write -documentation, install early releases for testing, write cryptographic code -outside the United States, sell pre-packaged software or systems including -this technology, and teach classes for network administrators who want to -install this technology. To offer to help, send me email at gnu@toad.com. -Tell me what country you live in and what your citizenship is (it matters due -to the export control laws; personally I don't care). Include a copy of your -resume and the URL of your home page. Describe what you'd like to do for the -project, and what you're uniquely qualified for. Mention what other -volunteer projects you've been involved in (and how they worked out). Helping -out will require that you be able to commit to doing particular things, meet -your commitments, and be responsive by email. Volunteer projects just don't -work without those things.</p> - -<h4>Related projects</h4> -<dl> - <dt>IPSEC for NetBSD</dt> - <dd>This prototype implementation of the IP Security protocols is for - another free operating system. <a - href="ftp://ftp.funet.fi/pub/unix/security/net/ip/BSDipsec.tar.gz">Download - BSDipsec.tar.gz</a>.</dd> - <dt>IPSEC for <a href="http://www.openbsd.org">OpenBSD</a></dt> - <dd>This prototype implementation of the IP Security protocols is for yet - another free operating system. It is directly integrated into the OS - release, since the OS is maintained in Canada, which has freedom of - speech in software.</dd> -</dl> - -<h3><a name="policestate">Stopping wholesale monitoring</a></h3> - -<p>From a message project leader John Gilmore posted to the mailing list:</p> -<pre>John Denker wrote: - -> Indeed there are several ways in which the documentation overstates the -> scope of what this project does -- starting with the name -> FreeS/WAN. There's a big difference between having an encrypted IP tunnel -> versus having a Secure Wide-Area Network. This software does a fine job of -> the former, which is necessary but not sufficient for the latter. - -The goal of the project is to make it very hard to tap your wide area -communications. The current system provides very good protection -against passive attacks (wiretapping and those big antenna farms). -Active attacks, which involve the intruder sending packets to your -system (like packets that break into sendmail and give them a root -shell :-) are much harder to guard against. Active attacks that -involve sending people (breaking into your house and replacing parts -of your computer with ones that transmit what you're doing) are also -much harder to guard against. Though we are putting effort into -protecting against active attacks, it's a much bigger job than merely -providing strong encryption. It involves general computer security, -and general physical security, which are two very expensive problems -for even a site to solve, let alone to build into a whole society. - -The societal benefit of building an infrastructure that protects -well against passive attacks is that it makes it much harder to do -undetected bulk monitoring of the population. It's a defense against -police-states, not against policemen. - -Policemen can put in the effort required to actively attack sites that -they have strong suspicions about. But police states won't be able to -build systems that automatically monitor everyone's communications. -Either they will be able to monitor only a small subset of the -populace (by targeting those who screwed up their passive security), -or their monitoring activities will be detectable by those monitored -(active attacks leave packet traces or footprints), which can then be -addressed through the press and through political means if they become -too widespread. - -FreeS/WAN does not protect very well against traffic analysis, which -is a kind of widespread police-state style monitoring that still -reveals significant information (who's talking to who) without -revealing the contents of what was said. Defenses against traffic -analysis are an open research problem. Zero Knowledge Systems is -actively deploying a system designed to thwart it, designed by Ian -Goldberg. The jury is out on whether it actually works; a lot more -experience with it will be needed.</pre> - -<p>Notes on things mentioned in that message:</p> -<ul> - <li>Denker is a co-author of a <a href="intro.html#applied">paper</a> on a - large FreeS/WAN application.</li> - <li>Information on Zero Knowledge is on their <a - href="http://www.zks.net/">web site</a>. Their Freedom product, designed - to provide untracable pseudonyms for use on the net, is no longer - marketed.</li> - <li>Another section of our documentation discusses ways to <a - href="ipsec.html#traffic.resist">resist traffic analysis</a>.</li> -</ul> - -<h2><a name="weak">Government promotion of weak crypto</a></h2> - -<p>Various groups, especially governments and especially the US government, -have a long history of advocating various forms of bogus security.</p> - -<p>We regard bogus security as extremely dangerous. If users are deceived -into relying on bogus security, then they may be exposed to large risks. They -would be better off having no security and knowing it. At least then they -would be careful about what they said.</p> - -<p><strong>Avoiding bogus security is a key design criterion for everything -we do in FreeS/WAN</strong>. The most conspicuous example is our refusal to -support <a href="#desnotsecure">single DES</a>. Other IPsec "features" which -we do not implement are discussed in our <a -href="compat.html#dropped">compatibility</a> document.</p> - -<h3><a name="escrow">Escrowed encryption</a></h3> - -<p>Various governments have made persistent attempts to encourage or mandate -"escrowed encrytion", also called "key recovery", or GAK for "government -access to keys". The idea is that cryptographic keys be held by some third -party and turned over to law enforcement or security agencies under some -conditions.</p> -<pre> Mary had a little key - she kept it in escrow, - and every thing that Mary said, - the feds were sure to know.</pre> - -<p>A <a href="web.html#quotes">crypto quotes</a> page attributes this to <a -href="http://www.scramdisk.clara.net/">Sam Simpson</a>.</p> - -<p>There is an excellent paper available on <a -href="http://www.cdt.org/crypto/risks98/">Risks of Escrowed Encryption</a>, -from a group of cryptographic luminaries which included our project -leader.</p> - -<p>Like any unnecessary complication, GAK tends to weaken security of any -design it infects. For example:</p> -<ul> - <li>Matt Blaze found a fatal flaw in the US government's Clipper chip - shortly after design information became public. See his paper "Protocol - Failure in the Escrowed Encryption Standard" on his <a - href="http://www.crypto.com/papers/">papers</a> page.</li> - <li>a rather <a href="http://www.pgp.com/other/advisories/adk.asp">nasty - bug</a> was found in the "additional decryption keys" "feature" of some - releases of <a href="glossary.html#PGP">PGP</a></li> -</ul> - -<p>FreeS/WAN does not support escrowed encryption, and never will.</p> - -<h3><a name="shortkeys">Limited key lengths</a></h3> - -<p>Various governments, and some vendors, have also made persistent attempts -to convince people that:</p> -<ul> - <li>weak systems are sufficient for some data</li> - <li>strong cryptography should be reserved for cases where the extra - overheads are justified</li> -</ul> - -<p><strong>This is utter nonsense</strong>.</p> - -<p>Weak systems touted include:</p> -<ul> - <li>the ludicrously weak (deliberately crippled) 40-bit ciphers that until - recently were all various <a href="#exlaw">export laws</a> allowed</li> - <li>56-bit single DES, discussed <a href="#desnotsecure">below</a></li> - <li>64-bit symmetric ciphers and 512-bit RSA, the maximums for unrestricted - export under various current laws</li> -</ul> - -<p>The notion that choice of ciphers or keysize should be determined by a -trade-off between security requirements and overheads is pure bafflegab.</p> -<ul> - <li>For most <a href="glossary.html#symmetric">symmetric ciphers</a>, it is - simply a lie. Any block cipher has some natural maximum keysize inherent - in the design -- 128 bits for <a href="glossary.html#IDEA">IDEA</a> or <a - href="glossary.html#CAST128">CAST-128</a>, 256 for Serpent or Twofish, - 448 for <a href="glossary.html#Blowfish">Blowfish</a> and 2048 for <a - href="glossary.html#RC4">RC4</a>. Using a key size smaller than that - limit gives <em>exactly zero </em>savings in overhead. The crippled - 40-bit or 64-bit version of the cipher provides <em>no advantage - whatsoever</em>.</li> - <li><a href="glossary.html#AES">AES</a> uses 10 rounds with 128-bit keys, - 12 rounds for 192-bit and 14 rounds for 256-bit, so there actually is a - small difference in overhead, but not enough to matter in most - applications.</li> - <li>For <a href="glossary.html#3DES">triple DES</a> there is a grain of - truth in the argument. 3DES is indeed three times slower than single DES. - However, the solution is not to use the insecure single DES, but to pick - a faster secure cipher. <a href="glossary.html#CAST128">CAST-128</a>, <a - href="glossary.html#Blowfish">Blowfish</a> and the <a - href="glossary.html#AES">AES candidate</a> ciphers are are all - considerably faster in software than DES (let alone 3DES!), and - apparently secure.</li> - <li>For <a href="glossary.html#public">public key</a> techniques, there are - extra overheads for larger keys, but they generally do not affect overall - performance significantly. Practical public key applications are usually - <a href="glossary.html#hybrid">hybrid</a> systems in which the bulk of - the work is done by a symmetric cipher. The effect of increasing the cost - of the public key operations is typically negligible because the public - key operations use only a tiny fraction of total resources. - <p>For example, suppose public key operations use use 1% of the time in a - hybrid system and you triple the cost of public key operations. The cost - of symmetric cipher operations is unchanged at 99% of the original total - cost, so the overall effect is a jump from 99 + 1 = 100 to 99 + 3 = 102, - a 2% rise in system cost.</p> - </li> -</ul> - -<p>In short, <strong>there has never been any technical reason to use -inadequate ciphers</strong>. The only reason there has ever been for anyone -to use such ciphers is that government agencies want weak ciphers used so -that they can crack them. The alleged savings are simply propaganda.</p> -<pre> Mary had a little key (It's all she could export), - and all the email that she sent was opened at the Fort.</pre> - -<p>A <a href="web.html#quotes">crypto quotes</a> page attributes this to <a -href="http://theory.lcs.mit.edu:80/~rivest/">Ron Rivest</a>. NSA headquarters -is at Fort Meade, Maryland.</p> - -<p>Our policy in FreeS/WAN is to use only cryptographic components with -adequate keylength and no known weaknesses.</p> -<ul> - <li>We do not implement single DES because it is clearly <a - href="#desnotsecure">insecure</a>, so implemeting it would violate our - policy of avoiding bogus security. Our default cipher is <a - href="glossary.html#3DES">3DES</a></li> - <li>Similarly, we do not implement the 768-bit Group 1 for <a - href="glossary.html#DH">Diffie-Hellman</a> key negotiation. We provide - only the 1024-bit Group 2 and 1536-bit Group 5.</li> -</ul> - -<p>Detailed discussion of which IPsec features we implement or omit is in out -<a href="compat.html">compatibility document</a>.</p> - -<p>These decisions imply that we cannot fully conform to the IPsec RFCs, -since those have DES as the only required cipher and Group 1 as the only -required DH group. (In our view, the standards were subverted into offerring -bogus security.) Fortunately, we can still interoperate with most other IPsec -implementations since nearly all implementers provide at least 3DES and Group -2 as well.</p> - -<p>We hope that eventually the RFCs will catch up with our (and others') -current practice and reject dubious components. Some of our team and a number -of others are working on this in <a href="glossary.html#IETF">IETF</a> -working groups.</p> - -<h4>Some real trade-offs</h4> - -<p>Of course, making systems secure does involve costs, and trade-offs can be -made between cost and security. However, the real trade-offs have nothing to -do with using weaker ciphers.</p> - -<p>There can be substantial hardware and software costs. There are often -substantial training costs, both to train administrators and to increase user -awareness of security issues and procedures. There are almost always -substantial staff or contracting costs.</p> - -<p>Security takes staff time for planning, implementation, testing and -auditing. Some of the issues are subtle; you need good (hence often -expensive) people for this. You also need people to monitor your systems and -respond to problems. The best safe ever built is insecure if an attacker can -work on it for days without anyone noticing. Any computer is insecure if the -administrator is "too busy" to check the logs.</p> - -<p>Moreover, someone in your organisation (or on contract to it) needs to -spend considerable time keeping up with new developments. EvilDoers -<em>will</em> know about new attacks shortly after they are found. You need -to know about them before your systems are attacked. If your vendor provides -a patch, you need to apply it. If the vendor does nothing, you need to -complain or start looking for another vendor.</p> - -<p>For a fairly awful example, see this <a -href="http://www.sans.org/newlook/alerts/NTE-bank.htm">report</a>. In that -case over a million credit card numbers were taken from e-commerce sites, -using security flaws in Windows NT servers. Microsoft had long since released -patches for most or all of the flaws, but the site administrators had not -applied them.</p> - -<p>At an absolute minimum, you must do something about such issues -<em>before</em> an exploitation tool is posted to the net for downloading by -dozens of "script kiddies". Such a tool might appear at any time from the -announcement of the security hole to several months later. Once it appears, -anyone with a browser and an attitude can break any system whose -administrators have done nothing about the flaw.</p> - -<p>Compared to those costs, cipher overheads are an insignificant factor in -the cost of security.</p> - -<p>The only thing using a weak cipher can do for you is to cause all your -other investment to be wasted.</p> - -<h2><a name="exlaw">Cryptography Export Laws</a></h2> - -<p>Many nations restrict the export of cryptography and some restrict its use -by their citizens or others within their borders.</p> - -<h3><a name="USlaw">US Law</a></h3> - -<p>US laws, as currently interpreted by the US government, forbid export of -most cryptographic software from the US in machine-readable form without -government permission. In general, the restrictions apply even if the -software is widely-disseminated or public-domain and even if it came from -outside the US originally. Cryptography is legally a munition and export is -tightly controlled under the <a href="glossary.html#EAR">EAR</a> Export -Administration Regulations.</p> - -<p>If you are a US citizen, your brain is considered US territory no matter -where it is physically located at the moment. The US believes that its laws -apply to its citizens everywhere, not just within the US. Providing technical -assistance or advice to foreign "munitions" projects is illegal. The US -government has very little sense of humor about this issue and does not -consider good intentions to be sufficient excuse. Beware.</p> - -<p>The <a href="http://www.bxa.doc.gov/Encryption/">official website</a> for -these regulations is run by the Commerce Department's Bureau of Export -Administration (BXA).</p> - -<p>The <a href="http://www.eff.org/bernstein/">Bernstein case</a> challenges -the export restrictions on Constitutional grounds. Code is speech so -restrictions on export of code violate the First Amendment's free speech -provisions. This argument has succeeded in two levels of court so far. It is -quite likely to go on to the Supreme Court.</p> - -<p>The regulations were changed substantially in January 2000, apparently as -a government attempt to get off the hook in the Bernstein case. It is now -legal to export public domain source code for encryption, provided you notify -the <a href="glossary.html#BXA">BXA</a>.</p> - -<p>There are, however, still restrictions in force. - Moreover, the regulations can still be changed again whenever the government -chooses to do so. Short of a Supreme Court ruling (in the Berstein case or -another) that overturns the regulations completely, the problem of export -regulation is not likely to go away in the forseeable future.</p> - -<h4><a name="UScontrib">US contributions to FreeS/WAN</a></h4> - -<p>The FreeS/WAN project <strong>cannot accept software contributions, <em> -not even small bug fixes</em>, from US citizens or residents</strong>. We -want it to be absolutely clear that our distribution is not subject to US -export law. Any contribution from an American might open that question to a -debate we'd prefer to avoid. It might also put the contributor at serious -legal risk.</p> - -<p>Of course Americans can still make valuable contributions (many already -have) by reporting bugs, or otherwise contributing to discussions, on the -project <a href="mail.html">mailing list</a>. Since the list is public, this -is clearly constitutionally protected free speech.</p> - -<p>Note, however, that the export laws restrict Americans from providing -technical assistance to foreign "munitions" projects. The government might -claim that private discussions or correspondence with FreeS/WAN developers -were covered by this. It is not clear what the courts would do with such a -claim, so we strongly encourage Americans to use the list rather than risk -the complications.</p> - -<h3><a name="wrong">What's wrong with restrictions on cryptography</a></h3> - -<p>Some quotes from prominent cryptography experts:</p> - -<blockquote> - The real aim of current policy is to ensure the continued effectiveness of - US information warfare assets against individuals, businesses and - governments in Europe and elsewhere.<br> - <a href="http://www.cl.cam.ac.uk/users/rja14"> Ross Anderson, Cambridge - University</a></blockquote> - -<blockquote> - If the government were honest about its motives, then the debate about - crypto export policy would have ended years ago.<br> - <a href="http://www.counterpane.com"> Bruce Schneier, Counterpane - Systems</a></blockquote> - -<blockquote> - The NSA regularly lies to people who ask it for advice on export control. - They have no reason not to; accomplishing their goal by any legal means is - fine by them. Lying by government employees is legal.<br> - John Gilmore.</blockquote> - -<p>The Internet Architecture Board (IAB) and the Internet Engineering -Steering Group (IESG) made a <a href="iab-iesg.stmt">strong statement</a> in -favour of worldwide access to strong cryptography. Essentially the same -statement is in the appropriately numbered <a -href="ftp://ftp.isi.edu/in-notes/rfc1984.txt">RFC 1984</a>. Two critical -paragraphs are:</p> - -<blockquote> - ... various governments have actual or proposed policies on access to - cryptographic technology ... - - <p>(a) ... export controls ...<br> - (b) ... short cryptographic keys ...<br> - (c) ... keys should be in the hands of the government or ...<br> - (d) prohibit the use of cryptology ...</p> - - <p>We believe that such policies are against the interests of consumers and - the business community, are largely irrelevant to issues of military - security, and provide only a marginal or illusory benefit to law - enforcement agencies, ...</p> - - <p>The IAB and IESG would like to encourage policies that allow ready - access to uniform strong cryptographic technology for all Internet users in - all countries.</p> -</blockquote> - -<p>Our goal in the FreeS/WAN project is to build just such "strong -cryptographic technology" and to distribute it "for all Internet users in all -countries".</p> - -<p>More recently, the same two bodies (IESG and IAB) have issued <a -href="ftp://ftp.isi.edu/in-notes/rfc2804.txt">RFC 2804</a> on why the IETF -should not build wiretapping capabilities into protocols for the convenience -of security or law enforcement agenicies. The abstract from that document -is:</p> - -<blockquote> - The Internet Engineering Task Force (IETF) has been asked to take a - position on the inclusion into IETF standards-track documents of - functionality designed to facilitate wiretapping. - - <p>This memo explains what the IETF thinks the question means, why its - answer is "no", and what that answer means.</p> -</blockquote> -A quote from the debate leading up to that RFC: - -<blockquote> - We should not be building surveillance technology into standards. Law - enforcement was not supposed to be easy. Where it is easy, it's called a - police state.<br> - Jeff Schiller of MIT, in a discussion of FBI demands for wiretap capability - on the net, as quoted by <a - href="http://www.wired.com/news/politics/0,1283,31895,00.html">Wired</a>.</blockquote> - -<p>The <a href="http://www.ietf.org/mailman/listinfo/raven">Raven</a> mailing -list was set up for this IETF discussion.</p> - -<p>Our goal is to go beyond that RFC and prevent Internet wiretapping -entirely.</p> - -<h3><a name="Wassenaar">The Wassenaar Arrangement</a></h3> - -<p>Restrictions on the export of cryptography are not just US policy, though -some consider the US at least partly to blame for the policies of other -nations in this area.</p> - -<p>A number of countries:</p> - -<p>Argentina, Australia, Austria, Belgium, Bulgaria, Canada, Czech Republic, -Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, -Luxembourg, Netherlands, New Zealand, Norway, Poland, Portugal, Republic of -Korea, Romania, Russian Federation, Slovak Republic, Spain, Sweden, -Switzerland, Turkey, Ukraine, United Kingdom and United States</p> - -<p>have signed the Wassenaar Arrangement which restricts export of munitions -and other tools of war. Cryptographic sofware is covered there.</p> - -<p>Wassenaar details are available from the <a -href="http://www.wassenaar.org/"> Wassenaar Secretariat</a>, and elsewhere in -a more readable <a href="http://www.fitug.de/news/wa/index.html"> HTML -version</a>.</p> - -<p>For a critique see the <a href="http://www.gilc.org/crypto/wassenaar"> -GILC site</a>:</p> - -<blockquote> - The Global Internet Liberty Campaign (GILC) has begun a campaign calling - for the removal of cryptography controls from the Wassenaar Arrangement. - - <p>The aim of the Wassenaar Arrangement is to prevent the build up of - military capabilities that threaten regional and international security and - stability . . .</p> - - <p>There is no sound basis within the Wassenaar Arrangement for the - continuation of any export controls on cryptographic products.</p> -</blockquote> - -<p>We agree entirely.</p> - -<p>An interesting analysis of Wassenaar can be found on the <a -href="http://www.cyber-rights.org/crypto/wassenaar.htm">cyber-rights.org</a> -site.</p> - -<h3><a name="status">Export status of Linux FreeS/WAN</a></h3> - -<p>We believe our software is entirely exempt from these controls since the -Wassenaar <a -href="http://www.wassenaar.org/list/GTN%20and%20GSN%20-%2099.pdf">General -Software Note</a> says:</p> - -<blockquote> - The Lists do not control "software" which is either: - <ol> - <li>Generally available to the public by . . . retail . . . or</li> - <li>"In the public domain".</li> - </ol> -</blockquote> - -<p>There is a note restricting some of this, but it is a sub-heading under -point 1, so it appears not to apply to public domain software.</p> - -<p>Their glossary defines "In the public domain" as:</p> - -<blockquote> - . . . "technology" or "software" which has been made available without - restrictions upon its further dissemination. - - <p>N.B. Copyright restrictions do not remove "technology" or "software" - from being "in the public domain".</p> -</blockquote> - -<p>We therefore believe that software freely distributed under the <a -href="glossary.html#GPL">GNU Public License</a>, such as Linux FreeS/WAN, is -exempt from Wassenaar restrictions.</p> - -<p>Most of the development work is being done in Canada. Our understanding is -that the Canadian government accepts this interpretation.</p> -<ul> - <li>A web statement of <a - href="http://www.dfait-maeci.gc.ca/~eicb/notices/ser113-e.htm"> Canadian - policy</a> is available from the Department of Foreign Affairs and - International Trade.</li> - <li>Another document from that department states that <a - href="http://www.dfait-maeci.gc.ca/~eicb/export/gr1_e.htm">public domain - software</a> is exempt from the export controls.</li> - <li>A researcher's <a - href="http://insight.mcmaster.ca/org/efc/pages/doc/crypto-export.html">analysis</a> - of Canadian policy is also available.</li> -</ul> - -<p>Recent copies of the freely modifiable and distributable source code exist -in many countries. Citizens all over the world participate in its use and -evolution, and guard its ongoing distribution. Even if Canadian policy were -to change, the software would continue to evolve in countries which do not -restrict exports, and would continue to be imported from there into unfree -countries. "The Net culture treats censorship as damage, and routes around -it."</p> - -<h3><a name="help">Help spread IPsec around</a></h3> - -<p>You can help. If you don't know of a Linux FreeS/WAN archive in your own -country, please download it now to your personal machine, and consider making -it publicly accessible if that doesn't violate your own laws. If you have the -resources, consider going one step further and setting up a mirror site for -the whole <a href="intro.html#munitions">munitions</a> Linux crypto software -archive.</p> - -<p>If you make Linux CD-ROMs, please consider including this code, in a way -that violates no laws (in a free country, or in a domestic-only CD -product).</p> - -<p>Please send a note about any new archive mirror sites or CD distributions -to linux-ipsec@clinet.fi so we can update the documentation.</p> - -<p>Lists of current <a href="intro.html#sites">mirror sites</a> and of <a -href="intro.html#distwith">distributions</a> which include FreeS/WAN are in -our introduction section.</p> - -<h2><a name="desnotsecure">DES is Not Secure</a></h2> - -<p>DES, the <strong>D</strong>ata <strong>E</strong>ncryption -<strong>S</strong>tandard, can no longer be considered secure. While no major -flaws in its innards are known, it is fundamentally inadequate because its -<strong>56-bit key is too short</strong>. It is vulnerable to <a -href="glossary.html#brute">brute-force search</a> of the whole key space, -either by large collections of general-purpose machines or even more quickly -by specialized hardware. Of course this also applies to <strong>any other -cipher with only a 56-bit key</strong>. The only reason anyone could have for -using a 56 or 64-bit key is to comply with various <a -href="exportlaw.html">export laws</a> intended to ensure the use of breakable -ciphers.</p> - -<p>Non-government cryptologists have been saying DES's 56-bit key was too -short for some time -- some of them were saying it in the 70's when DES -became a standard -- but the US government has consistently ridiculed such -suggestions.</p> - -<p>A group of well-known cryptographers looked at key lengths in a <a -href="http://www.counterpane.com/keylength.html"> 1996 paper</a>. They -suggested a <em>minimum</em> of 75 bits to consider an existing cipher secure -and a <em>minimum of 90 bits for new ciphers</em>. More recent papers, -covering both <a href="glossary.html#symmetric">symmetric</a> and <a -href="glossary.html#public">public key</a> systems are at <a -href="http://www.cryptosavvy.com/">cryptosavvy.com</a> and <a -href="http://www.rsasecurity.com/rsalabs/bulletins/bulletin13.html">rsa.com</a>. -For all algorithms, the minimum keylengths recommended in such papers are -significantly longer than the maximums allowed by various export laws.</p> - -<p>In a <a -href="http://www.privacy.nb.ca/cryptography/archives/cryptography/html/1998-09/0095.html">1998 -ruling</a>, a German court described DES as "out-of-date and not safe enough" -and held a bank liable for using it.</p> - -<h3><a name="deshware">Dedicated hardware breaks DES in a few days</a></h3> - -<p>The question of DES security has now been settled once and for all. In -early 1998, the <a href="http://www.eff.org/">Electronic Frontier -Foundation</a> built a <a -href="http://www.eff.org/descracker.html">DES-cracking machine</a>. It can -find a DES key in an average of a few days' search. The details of all this, -including complete code listings and complete plans for the machine, have -been published in <a href="biblio.html#EFF"><cite>Cracking DES</cite></a>, by -the Electronic Frontier Foundation.</p> - -<p>That machine cost just over $200,000 to design and build. "Moore's Law" is -that machines get faster (or cheaper, for the same speed) by roughly a factor -of two every 18 months. At that rate, their $200,000 in 1998 becomes $50,000 -in 2001.</p> - -<p>However, Moore's Law is not exact and the $50,000 estimate does not allow -for the fact that a copy based on the published EFF design would cost far -less than the original. We cannot say exactly what such a cracker would cost -today, but it would likely be somewhere between $10,000 and $100,000.</p> - -<p>A large corporation could build one of these out of petty cash. The cost -is low enough for a senior manager to hide it in a departmental budget and -avoid having to announce or justify the project. Any government agency, from -a major municipal police force up, could afford one. Or any other group with -a respectable budget -- criminal organisations, political groups, labour -unions, religious groups, ... Or any millionaire with an obsession or a -grudge, or just strange taste in toys.</p> - -<p>One might wonder if a private security or detective agency would have one -for rent. They wouldn't need many clients to pay off that investment.</p> - -<h3><a name="spooks">Spooks may break DES faster yet</a></h3> - -<p>As for the security and intelligence agencies of various nations, they may -have had DES crackers for years, and theirs may be much faster. It is -difficult to make most computer applications work well on parallel machines, -or to design specialised hardware to accelerate them. Cipher-cracking is one -of the very few exceptions. It is entirely straightforward to speed up -cracking by just adding hardware. Within very broad limits, you can make it -as fast as you like if you have the budget. The EFF's $200,000 machine breaks -DES in a few days. An <a href="http://www.planepage.com/">aviation -website</a> gives the cost of a B1 bomber as $200,000,000. Spending that -much, an intelligence agency could break DES in an average time of <em>six -and a half minutes</em>.</p> - -<p>That estimate assumes they use the EFF's 1998 technology and just spend -more money. They may have an attack that is superior to brute force, they -quite likely have better chip technology (Moore's law, a bigger budget, and -whatever secret advances they may have made) and of course they may have -spent the price of an aircraft carrier, not just one aircraft.</p> - -<p>In short, we have <em>no idea</em> how quickly these organisations can -break DES. Unless they're spectacularly incompetent or horribly underfunded, -they can certainly break it, but we cannot guess how quickly. Pick any time -unit between days and milliseconds; none is entirely unbelievable. More to -the point, none of them is of any comfort if you don't want such -organisations reading your communications.</p> - -<p>Note that this may be a concern even if nothing you do is a threat to -anyone's national security. An intelligence agency might well consider it to -be in their national interest for certain companies to do well. If you're -competing against such companies in a world market and that agency can read -your secrets, you have a serious problem.</p> - -<p>One might wonder about technology the former Soviet Union and its allies -developed for cracking DES during the Cold War. They must have tried; the -cipher was an American standard and widely used. Certainly those countries -have some fine mathematicians, and those agencies had budget. How well did -they succeed? Is their technology now for sale or rent?</p> - -<h3><a name="desnet">Networks break DES in a few weeks</a></h3> - -<p>Before the definitive EFF effort, DES had been cracked several times by -people using many machines. See this <a -href="http://www.distributed.net/pressroom/DESII-1-PR.html"> press -release</a> for example.</p> - -<p>A major corporation, university, or government department could break DES -by using spare cycles on their existing collection of computers, by -dedicating a group of otherwise surplus machines to the problem, or by -combining the two approaches. It might take them weeks or months, rather than -the days required for the EFF machine, but they could do it.</p> - -<p>What about someone working alone, without the resources of a large -organisation? For them, cracking DES will not be easy, but it may be -possible. A few thousand dollars buys a lot of surplus workstations. A pile -of such machines will certainly heat your garage nicely and might break DES -in a few months or years. Or enroll at a university and use their machines. -Or use an employer's machines. Or crack security somewhere and steal the -resources to crack a DES key. Or write a virus that steals small amounts of -resources on many machines. Or . . .</p> - -<p>None of these approaches are easy or break DES really quickly, but an -attacker only needs to find one that is feasible and breaks DES quickly -enough to be dangerous. How much would you care to bet that this will be -impossible if the attacker is clever and determined? How valuable is your -data? Are you authorised to risk it on a dubious bet?</p> - -<h3><a name="no_des">We disable DES</a></h3> - -<p>In short, it is now absolutely clear that <strong>DES is not -secure</strong> against</p> -<ul> - <li>any <strong>well-funded opponent</strong></li> - <li>any opponent (even a penniless one) with access (even stolen access) to - <strong>enough general purpose computers</strong></li> -</ul> - -<p>That is why <strong>Linux FreeS/WAN disables all transforms which use -plain DES</strong> for encryption.</p> - -<p>DES is in the source code, because we need DES to implement our default -encryption transform, <a href="glossary.html#3DES">Triple DES</a>. <strong>We -urge you not to use single DES</strong>. We do not provide any easy way to -enable it in FreeS/WAN, and our policy is to provide no assistance to anyone -wanting to do so.</p> - -<h3><a name="40joke">40-bits is laughably weak</a></h3> - -<p>The same is true, in spades, of ciphers -- DES or others -- crippled by -40-bit keys, as many ciphers were required to be until recently under various -<a href="#exlaw">export laws</a>. A brute force search of such a cipher's -keyspace is 2<sup>16</sup> times faster than a similar search against DES. -The EFF's machine can do a brute-force search of a 40-bit key space in -<em>seconds</em>. One contest to crack a 40-bit cipher was won by a student -<a href="http://catless.ncl.ac.uk/Risks/18.80.html#subj1"> using a few -hundred idle machines at his university</a>. It took only three and half -hours.</p> - -<p>We do not, and will not, implement any 40-bit cipher.</p> - -<h3><a name="altdes">Triple DES is almost certainly secure</a></h3> - -<p><a href="glossary.html#3DES">Triple DES</a>, usually abbreviated 3DES, -applies DES three times, with three different keys. DES seems to be basically -an excellent cipher design; it has withstood several decades of intensive -analysis without any disastrous flaws being found. It's only major flaw is -that the small keyspace allows brute force attacks to succeeed. Triple DES -enlarges the key space to 168 bits, making brute-force search a ridiculous -impossibility.</p> - -<p>3DES is currently the only block cipher implemented in FreeS/WAN. 3DES is, -unfortunately, about 1/3 the speed of DES, but modern CPUs still do it at -quite respectable speeds. Some <a href="glossary.html#benchmarks">speed -measurements</a> for our code are available.</p> - -<h3><a name="aes.ipsec">AES in IPsec</a></h3> - -<p>The <a href="glossary.html#AES">AES</a> project has chosen a replacement -for DES, a new standard cipher for use in non-classified US government work -and in regulated industries such as banking. This cipher will almost -certainly become widely used for many applications, including IPsec.</p> - -<p>The winner, announced in October 2000 after several years of analysis and -discussion, was the <a -href="http://www.esat.kuleuven.ac.be/~rijmen/rijndael/">Rijndael</a> cipher -from two Belgian designers.</p> - -<p>It is almost certain that FreeS/WAN will add AES support. <a -href="web.html#patch">AES patches</a> are already available.</p> - -<h2><a name="press">Press coverage of Linux FreeS/WAN:</a></h2> - -<h3>FreeS/WAN 1.0 press</h3> -<ul> - <li><a - href="http://www.wired.com/news/news/technology/story/19136.html">Wired</a> - "Linux-Based Crypto Stops Snoops", James Glave April 15 1999</li> - <li><a - href="http://slashdot.org/articles/99/04/15/1851212.shtml">Slashdot</a></li> - <li><a href="http://dgl.com/itinfo/1999/it990415.html">DGL</a>, Damar Group - Limited; looking at FreeS/WAN from a perspective of business - computing</li> - <li><a href="http://linuxtoday.com/stories/5010.html">Linux Today</a></li> - <li><a href="http://www.tbtf.com/archive/1999-04-21.html#Tcep">TBTF</a>, - Tasty Bits from the Technology Front</li> - <li><a - href="http://www.salonmagazine.com/tech/log/1999/04/16/encryption/index.html">Salon - Magazine</a> "Free Encryption Takes a Big Step"</li> -</ul> - -<h3><a name="release">Press release for version 1.0</a></h3> -<pre> Strong Internet Privacy Software Free for Linux Users Worldwide - -Toronto, ON, April 14, 1999 - - -The Linux FreeS/WAN project today released free software to protect -the privacy of Internet communications using strong encryption codes. -FreeS/WAN automatically encrypts data as it crosses the Internet, to -prevent unauthorized people from receiving or modifying it. One -ordinary PC per site runs this free software under Linux to become a -secure gateway in a Virtual Private Network, without having to modify -users' operating systems or application software. The project built -and released the software outside the United States, avoiding US -government regulations which prohibit good privacy protection. -FreeS/WAN version 1.0 is available immediately for downloading at -http://www.xs4all.nl/~freeswan/. - -"Today's FreeS/WAN release allows network administrators to build -excellent secure gateways out of old PCs at no cost, or using a cheap -new PC," said John Gilmore, the entrepreneur who instigated the -project in 1996. "They can build operational experience with strong -network encryption and protect their users' most important -communications worldwide." - -"The software was written outside the United States, and we do not -accept contributions from US citizens or residents, so that it can be -freely published for use in every country," said Henry Spencer, who -built the release in Toronto, Canada. "Similar products based in the -US require hard-to-get government export licenses before they can be -provided to non-US users, and can never be simply published on a Web -site. Our product is freely available worldwide for immediate -downloading, at no cost." - -FreeS/WAN provides privacy against both quiet eavesdropping (such as -"packet sniffing") and active attempts to compromise communications -(such as impersonating participating computers). Secure "tunnels" carry -information safely across the Internet between locations such as a -company's main office, distant sales offices, and roaming laptops. This -protects the privacy and integrity of all information sent among those -locations, including sensitive intra-company email, financial transactions -such as mergers and acquisitions, business negotiations, personal medical -records, privileged correspondence with lawyers, and information about -crimes or civil rights violations. The software will be particularly -useful to frequent wiretapping targets such as private companies competing -with government-owned companies, civil rights groups and lawyers, -opposition political parties, and dissidents. - -FreeS/WAN provides privacy for Internet packets using the proposed -standard Internet Protocol Security (IPSEC) protocols. FreeS/WAN -negotiates strong keys using Diffie-Hellman key agreement with 1024-bit -keys, and encrypts each packet with 168-bit Triple-DES (3DES). A modern -$500 PC can set up a tunnel in less than a second, and can encrypt -6 megabits of packets per second, easily handling the whole available -bandwidth at the vast majority of Internet sites. In preliminary testing, -FreeS/WAN interoperated with 3DES IPSEC products from OpenBSD, PGP, SSH, -Cisco, Raptor, and Xedia. Since FreeS/WAN is distributed as source code, -its innards are open to review by outside experts and sophisticated users, -reducing the chance of undetected bugs or hidden security compromises. - -The software has been in development for several years. It has been -funded by several philanthropists interested in increased privacy on -the Internet, including John Gilmore, co-founder of the Electronic -Frontier Foundation, a leading online civil rights group. - -Press contacts: -Hugh Daniel, +1 408 353 8124, hugh@toad.com -Henry Spencer, +1 416 690 6561, henry@spsystems.net - -* FreeS/WAN derives its name from S/WAN, which is a trademark of RSA Data - Security, Inc; used by permission.</pre> -</body> -</html> diff --git a/doc/src/quickstart-configs.html b/doc/src/quickstart-configs.html deleted file mode 100644 index b2ad21bcc..000000000 --- a/doc/src/quickstart-configs.html +++ /dev/null @@ -1,144 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>Quick FreeS/WAN installation and configuration</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, installation, quickstart"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Revised by Claudia Schmeing for same - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - This is a new file derived from: - RCS ID: $Id: quickstart-configs.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> -<BODY> -<H1><A name="quick_configs">FreeS/WAN quick start examples</A></H1> -<P>These are sample -<A href="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</A> -configuration files for opportunistic encryption, with comments. Much of -this configuration will be unnecessary with the new defaults proposed -for FreeS/WAN 2.x.</P> -<P>Full instructions are in our -<A href="quickstart.html#quickstart">quickstart guide</A>. - -<H2><A name="qc.opp.client">Configuration for Initiate-only Opportunistic Encryption</A></H2> -<P>The ipsec.conf file for an initiate-only opportunistic setup is:</P> -<PRE># general IPsec setup -config setup - # Use the default interface - interfaces=%defaultroute - # Use auto= parameters in conn descriptions to control startup actions. - plutoload=%search - plutostart=%search - uniqueids=yes - -# defaults for subsequent connection descriptions -conn %default - # How to authenticate gateways - authby=rsasig - # default is - # load connection description into Pluto's database - # so it can respond if another gatway initiates - # individual connection descriptions may override this - auto=add - -# description for opportunistic connections -conn me-to-anyone - left=%defaultroute # all connections should use default route - right=%opportunistic # anyone we can authenticate - leftrsasigkey=%dnsondemand # NEW: look up keys in DNS as-needed - rightrsasigkey=%dnsondemand # (not at connection load time) - rekey=no # let unused connections die - keylife=1h # short - auto=route # set up for opportunistic - leftid=@xy.example.com # our identity for IPSec negotiations - # must match DNS and ipsec.secrets</PRE> - -<P>Normally, you need to do only two things:</P> -<UL> - <LI>edit <VAR>leftid=</VAR></LI> - <LI>set <VAR>auto=route</VAR></LI> -</UL> -<P> - However, some people may need to customize the <VAR>interfaces=</VAR> line - in the "config setup" section. All other sections are identical for any - standalone machine doing opportunistic encryption.</P> -<P>The @ sign in the <VAR>leftid=</VAR> makes the ID go "over the wire" - as a Fully Qualified Domain Name (FQDN). Without it, an IP address would - be used and this won't work.</P> -<P>The conn is not used to supply either public key. Your private key - is in <A href="manpage.d/ipsec.secrets.5.html">ipsec.secrets(5)</A> - and, for opportunistic encryption, the public keys for remote gateways - are all looked up in DNS.</P> -<P>FreeS/WAN authenticates opportunistic encryption by <A href="#gen_rsa">RSA - signature</A> only, so "public key" and "private key" refer to these keys.</P> -<P>While the <VAR>left</VAR> and <VAR>right</VAR> designations - here are arbitrary, we follow a convention of using <VAR>left</VAR> for - local and <VAR>right</VAR> for remote.</P> - -<P><A href="quickstart.html#config.opp.client">Continue configuring -initiate-only opportunism.</A> - -<H2><A name="qc.incoming.opp.conf">ipsec.conf for Incoming Opportunistic Encryption</A></H2> -Use the ipsec.conf above, except that the section describing opportunistic -connections is now:</P> -<PRE> -# description for opportunistic connections -conn me-to-anyone - left=%defaultroute # all connections should use default route - right=%opportunistic # anyone we can authenticate - leftrsasigkey=%dnsondemand # NEW: look up keys in DNS as-needed - rightrsasigkey=%dnsondemand # (not at connection load time) - rekey=no # let unused connections die - keylife=1h # short - auto=route # set up for opportunistic</PRE> - -<P>Note that <VAR>leftid=</VAR> has been removed. With no explicit setting, -<VAR>leftid=</VAR> defaults to the IP of your public interface.</P> - -<P><A href="quickstart.html#incoming.opp.conf">Continue configuring -full opportunism.</A> - - -<H2><A name="qc.gate.opp.conf">ipsec.conf for Opportunistic Gateway</A></H2> -Use the ipsec.conf above, plus these connections: - -<PRE>conn subnet-to-anyone # must be above me-to-anyone - also=me-to-anyone - leftsubnet=42.42.42.0/24 - -conn me-to-anyone # just like for full opportunism - left=%defaultroute - right=%opportunistic - leftrsasigkey=%dnsondemand - rightrsasigkey=%dnsondemand - keylife=1h - rekey=no - auto=route # be sure this is enabled - # Note there is NO leftid= </PRE> - - -<P>Note that a subnet described in ipsec.conf(5) need not correspond to a - physical network segment. This is discussed in more detail in our -<A href="adv_config.html">advanced configuration</A> document.</P> - -<P>If required, a gateway can easily provide this service for more than one - subnet. You just add a connection description for each.</P> - -<P><A href="quickstart.html#config.opp.gate">Continue configuring an -opportunistic gateway.</A> - - -</BODY> -</HTML> - diff --git a/doc/src/quickstart-firewall.html b/doc/src/quickstart-firewall.html deleted file mode 100644 index 53c27b5af..000000000 --- a/doc/src/quickstart-firewall.html +++ /dev/null @@ -1,187 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>Quick FreeS/WAN installation and configuration</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, installation, quickstart"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Revised by Claudia Schmeing for same - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - RCS ID: $Id: quickstart-firewall.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> -<BODY> -<H1><A name="quick_firewall">FreeS/WAN quick start on firewalling</A></H1> -<P>This firewalling information supplements our -<A HREF="quickstart.html#quick_guide">quickstart guide.</A></P> -<P>It includes tips for firewalling:</P> -<UL> -<LI><A HREF="#firewall.standalone">a standalone system with initiator-only -opportunism</A></LI> -<LI><A HREF="#incoming.opp.firewall">incoming opportunistic connections</A></LI> -<LI><A HREF="#opp.gate.firewall">an opportunistic gateway</A></LI> -</UL> -<P>and a list of helpful <A HREF="#resources">resources</A>.</P> -<H2><A name="firewall.standalone">Firewalling a standalone system</A></H2> -<P>Firewall rules on a standalone system doing IPsec can be very simple.</P> -<P>The first step is to allow IPsec packets (IKE on UDP port 500 plus - ESP, protocol 50) in and out of your gateway. A script to set up - iptables(8) rules for this is:</P> -<PRE># edit this line to match the interface you use as default route -# ppp0 is correct for many modem, DSL or cable connections -# but perhaps not for you -world=ppp0 -# -# allow IPsec -# -# IKE negotiations -iptables -A INPUT -p udp -i $world --sport 500 --dport 500 -j ACCEPT -iptables -A OUTPUT -p udp -o $world --sport 500 --dport 500 -j ACCEPT -# ESP encryption and authentication -iptables -A INPUT -p 50 -i $world -j ACCEPT -iptables -A OUTPUT -p 50 -o $world -j ACCEPT</PRE> -<P>Optionally, you could restrict this, allowing these packets only to - and from a list of known gateways.</P> -<P>A second firewalling step -- access controls built into the IPsec - protocols -- is automatically applied:</P> -<DL> -<DT><A href="glossary.html#Pluto">Pluto</A> -- the FreeS/WAN keying - daemon -- deals with the IKE packets.</DT> -<DD>Pluto authenticates its partners during the IKE negotiation, and - drops negotiation if authentication fails.</DD> -<DT><A href="glossary.html#KLIPS">KLIPS</A> -- the FreeS/WAN kernel - component -- handles the ESP packets.</DT> -<DD> -<DL> -<DT>KLIPS drops outgoing packets</DT> -<DD>if they are routed to IPsec, but no tunnel has been negotiated for - them</DD> -<DT>KLIPS drops incoming unencrypted packets</DT> -<DD>if source and destination addresses match a tunnel; the packets - should have been encrypted</DD> -<DT>KLIPS drops incoming encrypted packets</DT> -<DD>if source and destination address do not match the negotiated - parameters of the tunnel that delivers them</DD> -<DD>if packet-level authentication fails</DD> -</DL> -</DD> -</DL> -<P>These errors are logged. See our <A href="trouble.html"> - troubleshooting</A> document for details.</P> -<P>As an optional third step, you may wish to filter packets emerging from - your opportunistic tunnels. - These packets arrive on an interface such as <VAR>ipsec0</VAR>, rather than - <VAR>eth0</VAR>, <VAR>ppp0</VAR> or whatever. For example, in an iptables(8) - rule set, you would use:</P> -<DL> -<DT><VAR>-i ipsec+</VAR></DT> -<DD>to specify packets arriving on any ipsec device</DD> -<DT><VAR>-o ipsec+</VAR></DT> -<DD>to specify packets leaving via any ipsec device</DD> -</DL> -<P>In this way, you can apply whatever additional filtering you like to these -packets.</P> -<P>The packets emerging on <VAR>ipsec0</VAR> are likely - to be things that a client application on your machine requested: web - pages, e-mail, file transfers and so on. However, any time you initiate - an opportunistic connection, you open a two-way connection to - another machine (or network). It is conceivable that a Bad Guy there - could take advantage of your link.</P> -<P>For more information, read the next section.</P> -</P> -<H2><A name="incoming.opp.firewall">Firewalling incoming opportunistic - connections</A></H2> -<P>The basic firewalling for IPsec does not change when you support - incoming connections as well as connections you initiate. You must - still allow IKE (UDP port 500) and ESP (protocol 50) packets to and - from your machine, as in the rules given <A href="#firewall.standalone"> - above</A>.</P> -<P>However, there is an additional security concern when you allow - incoming opportunistic connections. Incoming opportunistic packets - enter your machine via an IPSec tunnel. That is, they all appear as - ESP (protocol 50) packets, concealing whatever port and protocol - characteristics the packet within the tunnel has. Contained - in the tunnel as they pass through <VAR>ppp0</VAR> or <VAR>eth0</VAR>, - these packets can bypass your usual firewall rules on these interfaces. -<P>Consequently, you will want to firewall your <VAR>ipsec</VAR> interfaces - the way you would any publicly accessible interface.</P> -<P>A simple way to do this is to create one iptables(8) table with - all your filtering rules for incoming packets, and apply the entire table to - all public interfaces, including <VAR>ipsec</VAR> interfaces.</P> - -<H2><A name="opp.gate.firewall">Firewalling for opportunistic gateways</A></H2> -<P>On a gateway, the IPsec-related firewall rules applied for input and - output on the Internet side are exactly as shown -<A HREF="#firewall.standalone">above</A>. A gateway - exchanges exactly the same things -- UDP 500 packets and IPsec packets - -- with other gateways that a standalone system does, so it can use - exactly the same firewall rules as a standalone system would.</P> -<P>However, on a gateway there are additional things to do:</P> -<UL> -<LI>you have other interfaces and need rules for them</LI> -<LI>packets emerging from ipsec processing must be correctly forwarded</LI> -</UL> -<P>You need additional rules to handle these things. For example, adding - some rules to the set shown above we get:</P> -<PRE># edit this line to match the interface you use as default route -# ppp0 is correct for many modem, DSL or cable connections -# but perhaps not for you -world=ppp0 -# -# edit these lines to describe your internal subnet and interface -localnet=42.42.42.0/24 -internal=eth1 -# -# allow IPsec -# -# IKE negotiations -iptables -A INPUT -p udp -i $world --sport 500 --dport 500 -j ACCEPT -iptables -A OUTPUT -p udp -o $world --sport 500 --dport 500 -j ACCEPT -# ESP encryption and authentication -iptables -A INPUT -p 50 -i $world -j ACCEPT -iptables -A OUTPUT -p 50 -o $world -j ACCEPT -# -# packet forwarding for an IPsec gateway -# simplest possible rules -$ forward everything, with no attempt to filter -# -# handle packets emerging from IPsec -# ipsec+ means any of ipsec0, ipsec1, ... -iptables -A FORWARD -d $localnet -i ipsec+ -j ACCEPT -# simple rule for outbound packets -# let local net send anything -# IPsec will encrypt some of it -iptables -A FORWARD -s $localnet -i $internal -j ACCEPT </PRE> -<P>On a production gateway, you would no doubt need tighter rules than - the above.</P> -<H2><A NAME="resources">Firewall resources</A></H2> -<P>For more information, see these handy resources:</P> -<UL> -<LI><A href="http://www.netfilter.org/documentation/">netfilter - documentation</A></LI> -<LI>books such as: -<UL> -<LI>Cheswick and Bellovin, <A href="biblio.html#firewall.book">Firewalls - and Internet Security</A></LI> -<LI>Zeigler, <A href="biblio.html#Zeigler">Linux Firewalls</A>,</LI> -</UL> -</LI> -<LI><A href="firewall.html#firewall">our firewalls document</A></LI> -<LI><A href="web.html#firewall.web">our firewall links</A></LI> -</UL> -<A HREF="quickstart.html#quick.firewall">Back to our quickstart guide.</A> -</BODY> -</HTML> - - - diff --git a/doc/src/quickstart.html b/doc/src/quickstart.html deleted file mode 100644 index a74c11774..000000000 --- a/doc/src/quickstart.html +++ /dev/null @@ -1,458 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>Quick FreeS/WAN installation and configuration</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, installation, quickstart"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Revised by Claudia Schmeing for same - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: quickstart.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> -<BODY> -<H1><A name="quickstart">Quickstart Guide to Opportunistic Encryption</A></H1> -<A name="quick_guide"></A> - -<H2><A name="opp.setup">Purpose</A></H2> - -<P>This page will get you started using Linux FreeS/WAN with opportunistic - encryption (OE). OE enables you to set up IPsec tunnels - without co-ordinating with another - site administrator, and without hand configuring each tunnel. - If enough sites support OE, a "FAX effect" occurs, and - many of us can communicate without eavesdroppers.</P> - -<H3>OE "flag day"</H3> - -<P>As of FreeS/WAN 2.01, OE uses DNS TXT resource records (RRs) -only (rather than TXT with KEY). -This change causes a -<a href="http://jargon.watson-net.com/jargon.asp?w=flag+day">"flag day"</a>. -Users of FreeS/WAN 2.00 (or earlier) OE who are upgrading may require -additional resource records, as detailed in our -<a href="upgrading.html#upgrading.flagday">upgrading document</a>. -OE setup instructions here are for 2.02 or later.</P> - - -<H2><A name="opp.dns">Requirements</A></H2> - -<P>To set up opportunistic encryption, you will need:</P> -<UL> -<LI>a Linux box. For OE to the public Internet, this box must NOT -be behind <A HREF="glossary.html#NAT.gloss">Network Address Translation</A> -(NAT).</LI> -<LI>to install Linux FreeS/WAN 2.02 or later</LI> -<LI>either control over your reverse DNS (for full opportunism) or -the ability to write to some forward domain (for initiator-only). -<A HREF="http://www.fdns.net">This free DNS service</A> explicitly -supports forward TXT records for FreeS/WAN use.</LI> -<LI>(for full opportunism) a static IP</LI> -</UL> - -<P>Note: Currently, only Linux FreeS/WAN supports opportunistic -encryption.</P> - -<H2><A name="easy.install">RPM install</A></H2> - -<P>Our instructions are for a recent Red Hat with a 2.4-series stock or -Red Hat updated kernel. For other ways to install, see our -<A href="install.html#install">install document</A>.</P> - - -<H3>Download RPMs</H3> - -<P>If we have prebuilt RPMs for your Red Hat system, -this command will get them: -</P> - -<PRE> ncftpget ftp://ftp.xs4all.nl/pub/crypto/freeswan/binaries/RedHat-RPMs/`uname -r | tr -d 'a-wy-z'`/\*</PRE> - -<P>If that fails, you will need to try <A HREF="install.html">another install -method</A>. -Our kernel modules -<B>will only work on the Red Hat kernel they were built for</B>, -since they are very sensitive to small changes in the kernel.</P> - -<P>If it succeeds, you will have userland tools, a kernel module, and an -RPM signing key:</P> - -<PRE> freeswan-module-2.04_2.4.20_20.9-0.i386.rpm - freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm - freeswan-rpmsign.asc</PRE> - - -<H3>Check signatures</H3> - -<P>If you're running RedHat 8.x or later, import the RPM signing key into the -RPM database:</P> -<PRE> rpm --import freeswan-rpmsign.asc</PRE> - -<P>For RedHat 7.x systems, you'll need to add it to your -<A HREF="glossary.html#PGP">PGP</A> keyring:</P> -<PRE> pgp -ka freeswan-rpmsign.asc</PRE> - -<P>Check the digital signatures on both RPMs using:</P> -<PRE> rpm --checksig freeswan*.rpm </PRE> - -<P>You should see that these signatures are good:</P> -<PRE> freeswan-module-2.04_2.4.20_20.9-0.i386.rpm: pgp md5 OK - freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm: pgp md5 OK</PRE> - - -<H3>Install the RPMs</H3> - -<P>Become root:</P> -<PRE> su</PRE> - -<P>Install your RPMs with:<P> -<PRE> rpm -ivh freeswan*.rpm</PRE> - -<P>If you're upgrading from FreeS/WAN 1.x RPMs, and have problems with that -command, see -<A HREF="upgrading.html#upgrading.rpms">this note</A>.</P> - -<P>Then, start FreeS/WAN:</P> -<PRE> service ipsec start</PRE> - - -<H3><A name="testinstall">Test</A></H3> -<P>To check that you have a successful install, run:</P> -<PRE> ipsec verify</PRE> - -<P>You should see as part of the <var>verify</var> output:</P> -<PRE> - Checking your system to see if IPsec got installed and started correctly - Version check and ipsec on-path [OK] - Checking for KLIPS support in kernel [OK] - Checking for RSA private key (/etc/ipsec.secrets) [OK] - Checking that pluto is running [OK] - ...</PRE> - -<P>If any of these first four checks fails, see our -<A href="trouble.html#install.check">troubleshooting guide</A>. -</P> - -<H2><A name="opp.setups.list">Our Opportunistic Setups</A></H2> -<H3>Full or partial opportunism?</H3> -<P>Determine the best form of opportunism your system can support.</P> -<UL> -<LI>For <A HREF="#opp.incoming">full opportunism</A>, you'll need a static -IP and and either control over your reverse DNS or an ISP -that can add the required TXT record for you.</LI> -<LI>If you have a dynamic IP, and/or write access to forward DNS only, -you can do <A HREF="#opp.client">initiate-only opportunism</A></LI> -<LI>To protect traffic bound for real IPs behind your gateway, use -<A HREF="adv_config.html#opp.gate">this form of full opportunism</A>.</LI> -</UL> - -<H2><A name="opp.client">Initiate-only setup</A></H2> - -<H3>Restrictions</H3> -<P>When you set up initiate-only Opportunistic Encryption (iOE):</P> -<UL> -<LI>there will be <STRONG> no incoming connection requests</STRONG>; you - can initiate all the IPsec connections you need.</LI> -<LI><STRONG>only one machine is visible</STRONG> on your end of the - connection.</LI> -<LI>iOE also protects traffic on behalf of -<A HREF="glossary.html#NAT.gloss">NATted</A> hosts behind the iOE box.</LI> -</UL> -<P>You cannot network a group of initiator-only machines if none -of these is capable of responding to OE. If one is capable of responding, -you may be able to create a hub topology using routing.</P> - - -<H3><A name="forward.dns">Create and publish a forward DNS record</A></H3> - -<H4>Find a domain you can use</H4> - -<P>Find a DNS forward domain (e.g. example.com) where you can publish your key. -You'll need access to the DNS zone files for that domain. -This is common for a domain you own. Some free DNS providers, -such as <A HREF="http://www.fdns.net">this one</A>, also provide -this service.</P> - -<P>Dynamic IP users take note: the domain where you place your key - need not be associated with the IP address for your system, - or even with your system's usual hostname.</P> - -<H4>Choose your ID</H4> - -<P>Choose a name within that domain which you will use to identify your - machine. It's convenient if this can be the same as your hostname:</P> -<PRE> [root@xy root]# hostname --fqdn - xy.example.com</PRE> -<P>This name in FQDN (fully-qualified domain name) -format will be your ID, for DNS key lookup and IPsec -negotiation.</P> - - -<H4>Create a forward TXT record</H4> - -<P>Generate a forward TXT record containing your system's public key - with a command like:</P> -<PRE> ipsec showhostkey --txt @xy.example.com</PRE> -<P>using your chosen ID in place of -xy.example.com. -This command takes the contents of -/etc/ipsec.secrets and reformats it into something usable by ISC's BIND. - The result should look like this (with the key data trimmed down for - clarity):</P> -<PRE> - ; RSA 2192 bits xy.example.com Thu Jan 2 12:41:44 2003 - IN TXT "X-IPsec-Server(10)=@xy.example.com" - "AQOF8tZ2... ...+buFuFn/" -</PRE> - - -<H4>Publish the forward TXT record</H4> - -<P>Insert the record into DNS, or have a system adminstrator do it -for you. It may take up to 48 hours for the record to propagate, but -it's usually much quicker.</P> - -<H3>Test that your key has been published</H3> - -<P>Check your DNS work</P> - -<PRE> ipsec verify --host xy.example.com</PRE> - -<P>As part of the <var>verify</var> output, you ought to see something -like:</P> - -<PRE> ... - Looking for TXT in forward map: xy.example.com [OK] - ...</PRE> - -<P>For this type of opportunism, only the forward test is relevant; -you can ignore the tests designed to find reverse records.</P> - - -<H3>Configure, if necessary</H3> - -<P> -If your ID is the same as your hostname, -you're ready to go. -FreeS/WAN will use its -<A HREF="policygroups.html">built-in connections</A> to create -your iOE functionality. -</P> - -<P>If you have chosen a different ID, you must tell FreeS/WAN about it via -<A HREF="manpage.d/ipsec.conf.5.html"><VAR>ipsec.conf</VAR></A>: - -<PRE> config setup - myid=@myname.freedns.example.com</PRE> - -<P>and restart FreeS/WAN: -</P> -<PRE> service ipsec restart</PRE> -<P>The new ID will be applied to the built-in connections.</P> - -<P>Note: you can create more complex iOE configurations as explained in our -<A HREF="policygroups.html#policygroups">policy groups document</A>, or -disable OE using -<A HREF="policygroups.html#disable_policygroups">these instructions</A>.</P> - - -<H3>Test</H3> -<P>That's it! <A HREF="#opp.test">Test your connections</A>.</P> - -<A name="opp.incoming"></A><H2>Full Opportunism</H2> - -<P>Full opportunism -allows you to initiate and receive opportunistic connections on your -machine.</P> - -<A name="incoming.opp.dns"></A><H3>Put a TXT record in a Forward Domain</H3> - -<P>To set up full opportunism, first -<A HREF="#forward.dns">set up a forward TXT record</A> as for -<A HREF="#opp.client">initiator-only OE</A>, using -an ID (for example, your hostname) that resolves to your IP. Do not -configure <VAR>/etc/ipsec.conf</VAR>, but continue with the -instructions for full opportunism, below. -</P> - -<P>Note that this forward record is not currently necessary for full OE, -but will facilitate future features.</P> - - -<A name="incoming.opp.dns"></A><H3>Put a TXT record in Reverse DNS</H3> - -<P>You must be able to publish your DNS RR directly in the reverse domain. -FreeS/WAN will not follow a PTR which appears in the reverse, since -a second lookup at connection start time is too costly.</P> - - -<H4>Create a Reverse DNS TXT record</H4> - -<P>This record serves to publicize your FreeS/WAN public key. In - addition, it lets others know that this machine can receive opportunistic -connections, and asserts that the machine is authorized to encrypt on -its own behalf.</P> - -<P>Use the command:</P> -<PRE> ipsec showhostkey --txt 192.0.2.11</PRE> -<P>where you replace 192.0.2.11 with your public IP.</P> - -<P>The record (with key shortened) looks like:</P> -<PRE> ; RSA 2048 bits xy.example.com Sat Apr 15 13:53:22 2000 - IN TXT "X-IPsec-Server(10)=192.0.2.11" " AQOF8tZ2...+buFuFn/"</PRE> - - -<H4>Publish your TXT record</H4> - -<P>Send these records to your ISP, to be published in your IP's reverse map. -It may take up to 48 hours for these to propagate, but usually takes -much less time.</P> - - -<H3>Test your DNS record</H3> - -<P>Check your DNS work with</P> - -<PRE> ipsec verify --host xy.example.com</PRE> - -<P>As part of the <var>verify</var> output, you ought to see something like:</P> - -<PRE> ... - Looking for TXT in reverse map: 11.2.0.192.in-addr.arpa [OK] - ...</PRE> - -<P>which indicates that you've passed the reverse-map test.</P> - -<H3>No Configuration Needed</H3> - -<P>FreeS/WAN 2.x ships with full OE enabled, so you don't need to configure -anything. -To enable OE out of the box, FreeS/WAN 2.x uses the policy group -<VAR>private-or-clear</VAR>, -which creates IPsec connections if possible (using OE if needed), -and allows traffic in the clear otherwise. You can create more complex -OE configurations as described in our -<A HREF="policygroups.html#policygroups">policy groups document</A>, or -disable OE using -<A HREF="policygroups.html#disable_policygroups">these instructions</A>.</P> - -<P>If you've previously configured for initiator-only opportunism, remove - <VAR>myid=</VAR> from <VAR>config setup</VAR>, so that peer FreeS/WANs -will look up your key by IP. Restart FreeS/WAN so that your change will -take effect, with</P> - -<PRE> service ipsec restart</PRE> - - -<H3>Consider Firewalling</H3> - -<P>If you are running a default install of RedHat 8.x, take note: you will -need to alter your iptables rule setup to allow IPSec traffic through your -firewall. See <A HREF="firewall.html#simple.rules">our firewall document</A> -for sample <VAR>iptables</VAR> rules.</P> - - -<H3>Test</H3> - -<P>That's it. Now, <A HREF="#opp.test">test your connection</A>. - - - - -<H3>Test</H3> - -<P>Instructions are in the next section.</P> - - -<H2><A NAME="opp.test">Testing opportunistic connections</A></H2> - -<P>Be sure IPsec is running. You can see whether it is with:</P> -<PRE> ipsec setup status</PRE> -<P>If need be, you can restart it with:</P> -<PRE> service ipsec restart</PRE> - -<P>Load a FreeS/WAN test website from the host on which you're running -FreeS/WAN. Note: the feds may be watching these sites. Type one of:<P> -<PRE> links oetest.freeswan.org</PRE> -<PRE> links oetest.freeswan.nl</PRE> -<!--<PRE> links oetest.freeswan.ca</PRE>--> - -<P>A positive result looks like this:</P> - -<PRE> - You seem to be connecting from: 192.0.2.11 which DNS says is: - gateway.example.com - _________________________________________________________________ - - Status E-route - OE enabled 16 192.139.46.73/32 -> 192.0.2.11/32 => - tun0x2097@192.0.2.11 - OE enabled 176 192.139.46.77/32 -> 192.0.2.11/32 => - tun0x208a@192.0.2.11 -</PRE> - -<P>If you see this, congratulations! Your OE host or gateway will now encrypt -its own traffic whenever it can. For more OE tests, please see our -<A HREF="testing.html#test.oe">testing document</A>. If you have difficulty, -see our <A HREF="#oe.trouble">OE troubleshooting tips</A>. -</P> - - - -<H2>Now what?</H2> - -<P>Please see our <A HREF="policygroups.html">policy groups document</A> -for more ways to set up Opportunistic Encryption.</P> - -<P>You may also wish to make some <A HREF="config.html"> -pre-configured connections</A>. -</P> - -<H2>Notes</H2> - -<UL> -<LI>We assume some facts about your system in order to make Opportunistic -Encryption easier to configure. For example, we assume that you wish -to have FreeS/WAN secure your default interface.</LI> -<LI>You may change this, and other settings, by altering the -<VAR>config setup</VAR> section in -<VAR>/etc/ipsec.conf</VAR>. -</LI> -<LI>Note that the built-in connections used to build policy groups do -not inherit from <VAR>conn default</VAR>.</LI> -<!-- -<LI>If you do not define your local identity -(eg. <VAR>leftid</VAR>), this will be the IP address of your default -FreeS/WAN interface. ---> -<LI> -If you fail to define your local identity and -do not fill in your reverse DNS entry, you will not be able to use OE.</LI> -</UL> - -<A NAME="oe.trouble"></A><H2>Troubleshooting OE</H2> - -<P>See the OE troubleshooting hints in our -<A HREF="trouble.html#oe.trouble">troubleshooting guide</A>. -</P> - -<A NAME="oe.known-issues"></A><H2>Known Issues</H2> - -<P>Please see -<A HREF="opportunism.known-issues">this list</A> of known issues -with Opportunistic Encryption.</P> - - -</BODY> -</HTML> diff --git a/doc/src/reference.ESPUDP.xml b/doc/src/reference.ESPUDP.xml deleted file mode 100644 index c9b96cef3..000000000 --- a/doc/src/reference.ESPUDP.xml +++ /dev/null @@ -1,34 +0,0 @@ -<?xml version='1.0'?> -<!DOCTYPE reference SYSTEM 'rfc2629.dtd'> - -<reference anchor='ESPUDP'> - -<front> -<title abbrev='UDPESP'>UDP Encapsulation of IPsec Packets</title> -<author initials='A.' surname='Huttunen' fullname='Ari Huttunen'> -<organization>F-Secure Corporation</organization> -<address> -<postal> -<street>Tammasaarenkatu 7</street> -<street>FIN-00181 HELSINKI</street> -<country>Finland</country></postal> -<email>Ari.Huttunen@F-Secure.com</email></address></author> - -<author initials='W.' surname='Dixon' fullname='William Dixon'> -<organization>Microsoft</organization> -<address> -<postal> -<street>One Microsoft Way</street> -<street>Redmond</street> -<street>WA 98052</street> -<country>USA</country></postal> -<email>wdixon@microsoft.com</email></address></author> - -<date month='June' year='2001'></date> -<area>Security</area> -<keyword>IP security protocol</keyword> -<keyword>IPSEC</keyword> -<keyword>security</keyword></front> - -<seriesInfo name='ID' value='internet-draft (draft-ietf-ipsec-udp-encaps-00) (informative)' /> -</reference> diff --git a/doc/src/reference.KEYRESTRICT.xml b/doc/src/reference.KEYRESTRICT.xml deleted file mode 100644 index 62aa1ef96..000000000 --- a/doc/src/reference.KEYRESTRICT.xml +++ /dev/null @@ -1,31 +0,0 @@ -<?xml version='1.0'?> -<!DOCTYPE reference SYSTEM 'rfc2629.dtd'> - -<reference anchor='KEYRESTRICT'> - -<front> -<title abbrev='KEYRESTRICT'>Limiting the Scope of the KEY Resource Record</title> -<author initials='D.' surname='Massey' fullname='Dan Massey'> -<organization>USC/ISI</organization> -<address> -<postal> -<street>USC Informational Sciences Institute</street> -<street>3811 North Fairfax Drive, Suite 200</street> -<street>Arlington, VA 22203</street> -<country>USA</country></postal> -<email>masseyd@isi.edu</email></address></author> - -<author initials='S.' surname='Rose' fullname='Scott Rose'> -<organization>National Institute for Standards and Technology</organization> -<address> -<postal> -<street>Gaithersburg, MD</street> -<country>USA</country></postal> -<email>scott.rose@nist.gov</email></address></author> - -<date month='March' year='2002'></date> -<area>Internet</area> -</front> - -<seriesInfo name='ID' value='internet-draft (draft-ietf-dnsext-restrict-key-for-dnssec-02) (normative)' /> -</reference> diff --git a/doc/src/reference.MODPGROUPS.xml b/doc/src/reference.MODPGROUPS.xml deleted file mode 100644 index 5eaf83f89..000000000 --- a/doc/src/reference.MODPGROUPS.xml +++ /dev/null @@ -1,32 +0,0 @@ -<?xml version='1.0'?> -<!DOCTYPE reference SYSTEM 'rfc2629.dtd'> - -<reference anchor='MODPGROUPS'> - -<front> -<title abbrev='MODPGROUPS'>More MODP Diffie-Hellman groups for IKE</title> -<author initials='T.' surname='Kivinen' fullname='Tero Kivinen'> -<organization>SSH Communications Security</organization> -<address> -<postal> -<street>Fredrikinkatu 42</street> -<street>FIN-00100 HELSINKI</street> -<country>Finland</country></postal> -<email>kivinen@ssh.fi</email></address></author> - -<author initials='M.' surname='Kojo' fullname='Mika Kojo'> -<organization>University of Helsinki</organization> -<address> -<postal> -<street>HELSINKI</street> -<country>Finland</country></postal> -<email>mrskojo@cc.helsinki.fi</email></address></author> - -<date month='November' year='2001'></date> -<area>Security</area> -<keyword>IP security protocol</keyword> -<keyword>IPSEC</keyword> -<keyword>security</keyword></front> - -<seriesInfo name='ID' value='internet-draft (draft-ietf-ipsec-ike-modp-groups-03) (normative)' /> -</reference> diff --git a/doc/src/reference.OEspec.xml b/doc/src/reference.OEspec.xml deleted file mode 100644 index 29c6d6efd..000000000 --- a/doc/src/reference.OEspec.xml +++ /dev/null @@ -1,45 +0,0 @@ -<?xml version='1.0'?> -<!DOCTYPE reference SYSTEM 'rfc2629.dtd'> - -<reference anchor='OEspec'> - -<front> -<title abbrev='OEspec'>Opportunistic Encryption</title> - - <author initials="D.H." surname="Redelmeier" - fullname="D. Hugh Redelmeier"> - <organization abbrev="Mimosa">Mimosa</organization> - <address> - <postal> - <street>Somewhere</street> - <city>Toronto</city> - <region>ON</region> - <country>CA</country> - </postal> - <email>hugh@mimosa.com</email> - </address> - </author> - - <author initials="H." surname="Spencer" - fullname="Henry Spencer"> - <organization abbrev="SP Systems">SP Systems</organization> - <address> - <postal> - <street>Box 280 Station A</street> - <city>Toronto</city> - <region>ON</region> - <code>M5W 1B2</code> - <country>Canada</country> - </postal> - <email>henry@spsystems.net</email> - </address> - </author> - -<date month='May' year='2001'></date> -<keyword>IP security protocol</keyword> -<keyword>IPSEC</keyword> -<keyword>security</keyword></front> - -<seriesInfo name='paper' value='http://www.freeswan.org/freeswan_trees/freeswan-1.91/doc/opportunism.spec' /> -</reference> - diff --git a/doc/src/reference.RFC.3526.xml b/doc/src/reference.RFC.3526.xml deleted file mode 100644 index 54fed705a..000000000 --- a/doc/src/reference.RFC.3526.xml +++ /dev/null @@ -1,32 +0,0 @@ -<?xml version='1.0'?> -<!DOCTYPE reference SYSTEM 'rfc2629.dtd'> - -<reference anchor='RFC3526'> - -<front> -<title abbrev='MODPGROUPS'>More MODP Diffie-Hellman groups for IKE</title> -<author initials='T.' surname='Kivinen' fullname='Tero Kivinen'> -<organization>SSH Communications Security</organization> -<address> -<postal> -<street>Fredrikinkatu 42</street> -<street>FIN-00100 HELSINKI</street> -<country>Finland</country></postal> -<email>kivinen@ssh.fi</email></address></author> - -<author initials='M.' surname='Kojo' fullname='Mika Kojo'> -<organization>University of Helsinki</organization> -<address> -<postal> -<street>HELSINKI</street> -<country>Finland</country></postal> -<email>mrskojo@cc.helsinki.fi</email></address></author> - -<date month='March' year='2003'></date> -<area>Security</area> -<keyword>IP security protocol</keyword> -<keyword>IPSEC</keyword> -<keyword>security</keyword></front> - -<seriesInfo name='RFC' value='3526' /> -</reference> diff --git a/doc/src/responderstate.txt b/doc/src/responderstate.txt deleted file mode 100644 index f64b82983..000000000 --- a/doc/src/responderstate.txt +++ /dev/null @@ -1,43 +0,0 @@ - | - | IKE main mode - | phase 1 - V - .-----------------. - | unauthenticated | - | OE peer | - `-----------------' - | - | lookup KEY RR in in-addr.arpa - | (if ID_IPV4_ADDR) - | lookup KEY RR in forward - | (if ID_FQDN) - V - .-----------------. RR not found - | received DNS |---------------> log failure - | reply | - `----+--------+---' - phase 2 | \ misformatted - proposal | `------------------> log failure - V - .----------------. - | authenticated | identical initiator - | OE peer |--------------------> initiator - `----------------' connection found state machine - | - | look for TXT record for initiator - | - V - .---------------. - | authorized |---------------------> log failure - | OE peer | - `---------------' - | - | - V - potential OE - connection in - initiator state - machine - - -$Id: responderstate.txt,v 1.1 2004/03/15 20:35:24 as Exp $ diff --git a/doc/src/rfc.html b/doc/src/rfc.html deleted file mode 100644 index 762c66c6e..000000000 --- a/doc/src/rfc.html +++ /dev/null @@ -1,158 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>IPsec RFCs</title> - <meta name="keywords" - content="IPsec, VPN, security, FreeSWAN, RFC, standard"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: rfc.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1><a name="RFC">IPsec RFCs and related documents</a></h1> - -<h2><a name="RFCfile">The RFCs.tar.gz Distribution File</a></h2> - -<p>The Linux FreeS/WAN distribution is available from <a -href="http://www.xs4all.nl/~freeswan"> our primary distribution site</a> and -various mirror sites. To give people more control over their downloads, the -RFCs that define IP security are bundled separately in the file -RFCs.tar.gz.</p> - -<p>The file you are reading is included in the main distribution and is -available on the web site. It describes the RFCs included in the <a -href="#RFCs.tar.gz">RFCs.tar.gz</a> bundle and gives some pointers to <a -href="#sources">other ways to get them</a>.</p> - -<h2><a name="sources">Other sources for RFCs & Internet drafts</a></h2> - -<h3><a name="RFCdown">RFCs</a></h3> - -<p>RFCs are downloadble at many places around the net such as:</p> -<ul> - <li><a href="http://www.rfc-editor.org">http://www.rfc-editor.org</a></li> - <li><a href="http://nis.nsf.net/internet/documents/rfc">NSF.net</a></li> - <li><a href="http://sunsite.doc.ic.ac.uk/computing/internet/rfc">Sunsite in - the UK</a></li> -</ul> - -<p>browsable in HTML form at others such as:</p> -<ul> - <li><a - href="http://www.landfield.com/rfcs/index.html">landfield.com</a></li> - <li><a href="http://www.library.ucg.ie/Connected/RFC">Connected Internet - Encyclopedia</a></li> -</ul> - -<p>and some of them are available in translation:</p> -<ul> - <li><a href="http://www.eisti.fr/eistiweb/docs/normes/">French</a></li> -</ul> - -<p>There is also a published <a href="biblio.html#RFCs">Big Book of IPSEC -RFCs</a>.</p> - -<h3><a name="drafts">Internet Drafts</a></h3> - -<p>Internet Drafts, working documents which sometimes evolve into RFCs, are -also available.</p> -<ul> - <li><a href="http://www.ietf.org/ID.html">Overall reference page</a></li> - <li><a href="http://www.ietf.org/ids.by.wg/ipsec.html">IPsec</a> working - group</li> - <li><a href="http://www.ietf.org/ids.by.wg/ipsra.html">IPSRA (IPsec Remote - Access)</a> working group</li> - <li><a href="http://www.ietf.org/ids.by.wg/ipsp.html">IPsec Policy</a> - working group</li> - <li><a href="http://www.ietf.org/ids.by.wg/kink.html">KINK (Kerberized - Internet Negotiation of Keys)</a> working group</li> -</ul> - -<p>Note: some of these may be obsolete, replaced by later drafts or by -RFCs.</p> - -<h3><a name="FIPS1">FIPS standards</a></h3> - -<p>Some things used by <a href="glossary.html#IPSEC">IPsec</a>, such as <a -href="glossary.html#DES">DES</a> and <a href="glossary.html#SHA">SHA</a>, are -defined by US government standards called <a -href="glossary.html#FIPS">FIPS</a>. The issuing organisation, <a -href="glossary.html#NIST">NIST</a>, have a <a -href="http://www.itl.nist.gov/div897/pubs">FIPS home page</a>.</p> - -<h2><a name="RFCs.tar.gz">What's in the RFCs.tar.gz bundle?</a></h2> - -<p>All filenames are of the form rfc*.txt, with the * replaced with the RFC -number.</p> -<pre>RFC# Title</pre> - -<h3><a name="rfc.ov">Overview RFCs</a></h3> -<pre>2401 Security Architecture for the Internet Protocol -2411 IP Security Document Roadmap</pre> - -<h3><a name="basic.prot">Basic protocols</a></h3> -<pre>2402 IP Authentication Header -2406 IP Encapsulating Security Payload (ESP)</pre> - -<h3><a name="key.ike">Key management</a></h3> -<pre>2367 PF_KEY Key Management API, Version 2 -2407 The Internet IP Security Domain of Interpretation for ISAKMP -2408 Internet Security Association and Key Management Protocol (ISAKMP) -2409 The Internet Key Exchange (IKE) -2412 The OAKLEY Key Determination Protocol -2528 Internet X.509 Public Key Infrastructure</pre> - -<h3><a name="rfc.detail">Details of various things used</a></h3> -<pre>2085 HMAC-MD5 IP Authentication with Replay Prevention -2104 HMAC: Keyed-Hashing for Message Authentication -2202 Test Cases for HMAC-MD5 and HMAC-SHA-1 -2207 RSVP Extensions for IPSEC Data Flows -2403 The Use of HMAC-MD5-96 within ESP and AH -2404 The Use of HMAC-SHA-1-96 within ESP and AH -2405 The ESP DES-CBC Cipher Algorithm With Explicit IV -2410 The NULL Encryption Algorithm and Its Use With IPsec -2451 The ESP CBC-Mode Cipher Algorithms -2521 ICMP Security Failures Messages</pre> - -<h3><a name="rfc.ref">Older RFCs which may be referenced</a></h3> -<pre>1321 The MD5 Message-Digest Algorithm -1828 IP Authentication using Keyed MD5 -1829 The ESP DES-CBC Transform -1851 The ESP Triple DES Transform -1852 IP Authentication using Keyed SHA</pre> - -<h3><a name="rfc.dns">RFCs for secure DNS service, which IPsec may -use</a></h3> -<pre>2137 Secure Domain Name System Dynamic Update -2230 Key Exchange Delegation Record for the DNS -2535 Domain Name System Security Extensions -2536 DSA KEYs and SIGs in the Domain Name System (DNS) -2537 RSA/MD5 KEYs and SIGs in the Domain Name System (DNS) -2538 Storing Certificates in the Domain Name System (DNS) -2539 Storage of Diffie-Hellman Keys in the Domain Name System (DNS)</pre> - -<h3><a name="rfc.exp">RFCs labelled "experimental"</a></h3> -<pre>2521 ICMP Security Failures Messages -2522 Photuris: Session-Key Management Protocol -2523 Photuris: Extended Schemes and Attributes</pre> - -<h3><a name="rfc.rel">Related RFCs</a></h3> -<pre>1750 Randomness Recommendations for Security -1918 Address Allocation for Private Internets -1984 IAB and IESG Statement on Cryptographic Technology and the Internet -2144 The CAST-128 Encryption Algorithm</pre> -</body> -</html> diff --git a/doc/src/roadmap.html b/doc/src/roadmap.html deleted file mode 100644 index c9d85047c..000000000 --- a/doc/src/roadmap.html +++ /dev/null @@ -1,203 +0,0 @@ -<html> -<head> -<title>FreeS/WAN roadmap</title> -<meta name="keywords" content="Linux, IPsec, VPN, security, FreeSWAN"> - -<!-- - -Written by Sandy Harris for the Linux FreeS/WAN project -Freely distributable under the GNU General Public License - -More information at www.freeswan.org -Feedback to users@lists.freeswan.org - -CVS information: -RCS ID: $Id: roadmap.html,v 1.1 2004/03/15 20:35:24 as Exp $ -Last changed: $Date: 2004/03/15 20:35:24 $ -Revision number: $Revision: 1.1 $ - -CVS revision numbers do not correspond to FreeS/WAN release numbers. ---> -</head> - -<body> -<h1><a name="roadmap">Distribution Roadmap: What's Where in Linux FreeS/WAN</a></h1> - -<p> -This file is a guide to the locations of files within the FreeS/WAN -distribution. Everything described here should be on your system once you -download, gunzip, and untar the distribution.</p> - -<p>This distribution contains two major subsystems -</p> -<dl> - <dt><a href="#klips.roadmap">KLIPS</a></dt> - <dd>the kernel code</dd> - <dt><a href="#pluto.roadmap">Pluto</a></dt> - <dd>the user-level key-management daemon</dd> -</dl> - -<p>plus assorted odds and ends. -</p> -<h2><a name="top">Top directory</a></h2> - -<p>The top directory has essential information in text files:</p> - -<dl> - <dt>README</dt> - <dd>introduction to the software</dd> - <dt>INSTALL</dt> - <dd>short experts-only installation procedures. More detalied procedures are in - <a href="install.html">installation</a> and - <a href="config.html">configuration</a> HTML documents.</dd> - <dt>BUGS</dt> - <dd>major known bugs in the current release.</dd> - <dt>CHANGES</dt> - <dd>changes from previous releases</dd> - <dt>CREDITS</dt> - <dd>acknowledgement of contributors</dd> - <dt>COPYING</dt> - <dd>licensing and distribution information</dd> -</dl> - -<h2><a name="doc">Documentation</a></h2> - -<p> -The doc directory contains the bulk of the documentation, most of it in -HTML format. See the <a href="index.html">index file</a> for details. -</p> - -<h2><a name="klips.roadmap">KLIPS: kernel IP security</a></h2> -</a> -<p> -<a href="glossary.html#KLIPS">KLIPS</a> is <strong>K</strong>erne<strong>L</strong> -<strong>IP</strong> <strong>S</strong>ecurity. It lives in the klips -directory, of course. -</p> -<dl> - <dt>klips/doc</dt> - <dd>documentation</dd> - <dt>klips/patches</dt> - <dd>patches for existing kernel files</dd> - <dt>klips/test</dt> - <dd>test stuff</dd> - <dt>klips/utils</dt> - <dd>low-level user utilities</dd> - <dt>klips/net/ipsec</dt> - <dd>actual klips kernel files</dd> - <dt>klips/src</dt> - <dd>symbolic link to klips/net/ipsec - <p>The "make insert" step of installation installs the patches and makes - a symbolic link from the kernel tree to klips/net/ipsec. The odd name of - klips/net/ipsec is dictated by some annoying limitations of the scripts - which build the Linux kernel. The symbolic-link business is a bit - messy, but all the alternatives are worse.</p> - <p></p> - </dd> - <dt>klips/utils</dt> - <dd>Utility programs: - <p></p> - <dl> - <dt>eroute</dt> - <dd>manipulate IPsec extended routing tables</dd> - <dt>klipsdebug</dt> - <dd>set Klips (kernel IPsec support) debug features and level</dd> - <dt>spi</dt> - <dd>manage IPsec Security Associations</dd> - <dt>spigrp</dt> - <dd>group/ungroup IPsec Security Associations</dd> - <dt>tncfg</dt> - <dd>associate IPsec virtual interface with real interface</dd> - </dl> - <p>These are all normally invoked by ipsec(8) with commands such as</p> - <pre> ipsec tncfg <var>arguments</var></pre> - There are section 8 man pages for all of these; the names have "ipsec_" - as a prefix, so your man command should be something like: - <pre> man 8 ipsec_tncfg</pre> - </dd> -</dl> - -<h2><a name="pluto.roadmap">Pluto key and connection management daemon</a></h2> - -<p> -<a href="glossary.html#Pluto">Pluto</a> is our key management and negotiation daemon. It -lives in the pluto directory, along with its low-level user utility, -whack. -</p> -<p> -There are no subdirectories. Documentation is a man page, -<a href="manpage.d/ipsec_pluto.8.html">pluto.8</a>. This covers whack as well. -</p> - -<h2><a name="utils">Utils</a></h2> - -<p> -The utils directory contains a growing collection of higher-level user -utilities, the commands that administer and control the software. Most of the -things that you will actually have to run yourself are in there. -</p> -<dl> - <dt>ipsec</dt> - <dd>invoke IPsec utilities - <p>ipsec(8) is normally the only program installed in a standard - directory, /usr/local/sbin. It is used to invoke the others, both those - listed below and the ones in klips/utils mentioned above.</p> - <p></p> - </dd> - <dt>auto</dt> - <dd>control automatically-keyed IPsec connections</dd> - <dt>manual</dt> - <dd>take manually-keyed IPsec connections up and down</dd> - <dt>barf</dt> - <dd>generate copious debugging output</dd> - <dt>look</dt> - <dd>generate moderate amounts of debugging output</dd> -</dl> -<p> -There are .8 manual pages for these. look is covered in barf.8. The man pages -have an "ipsec_" prefix so your man command should be something like: -<pre> - man 8 ipsec_auto -</pre> -<p> -Examples are in various files with names utils/*.eg</p> - -<h2><a name="lib">Libraries</a></h2> - -<h3><a name="fswanlib">FreeS/WAN Library</a></h3> - -<p> -The lib directory is the FreeS/WAN library, also steadily growing, used by -both user-level and kernel code.<br /> -It includes section 3 <a href="manpages.html">man pages</a> for the library routines. -</p> -<h3><a name="otherlib">Imported Libraries</a></h3> - -<h4>LibDES</h4> - -The libdes library, originally from SSLeay, is used by both Klips and Pluto -for <a href="glossary.html#3DES">Triple DES</a> encryption. Single DES is not -used because <a href="politics.html#desnotsecure">it is -insecure</a>. -<p> -Note that this library has its own license, different from the -<a href="glossary.html#GPL">GPL</a> used for other code in FreeS/WAN. - </p> -<p> -The library includes its own documentation. - - -<h4>GMP</h4> - -The GMP (GNU multi-precision) library is used for multi-precision arithmetic -in Pluto's key-exchange code and public key code. -<p> -Older versions (up to 1.7) of FreeS/WAN included a copy of this library in -the FreeS/WAN distribution. -<p> -Since 1.8, we have begun to rely on the system copy of GMP. -</p> - -</body> -</html> - diff --git a/doc/src/testing.html b/doc/src/testing.html deleted file mode 100644 index 8ffcca604..000000000 --- a/doc/src/testing.html +++ /dev/null @@ -1,395 +0,0 @@ -<html> -<head> -<title>Testing FreeS/WAN</title> - -<meta name="keywords" content="Linux, IPsec, VPN, security, FreeSWAN, testing"> - -<!-- - -Written by Sandy Harris for the Linux FreeS/WAN project -Freely distributable under the GNU General Public License - -More information at www.freeswan.org -Feedback to users@lists.freeswan.org - -CVS information: -RCS ID: $Id: testing.html,v 1.1 2004/03/15 20:35:24 as Exp $ -Last changed: $Date: 2004/03/15 20:35:24 $ -Revision number: $Revision: 1.1 $ - -CVS revision numbers do not correspond to FreeS/WAN release numbers. ---> -</head> - -<body> -<h1><a name="test.freeswan">Testing FreeS/WAN</a></h1> -This document discusses testing FreeS/WAN. - -<p>Not all types of testing are described here. Other parts of the -documentation describe some tests:</p> -<dl> - <dt><a href="install.html#testinstall">installation</a> document</dt> - <dd>testing for a successful install</dd> - <dt><a href="config.html#testsetup">configuration</a> document</dt> - <dd>basic tests for a working configuration</dd> - <dt><a href="web.html#interop.web">web links</a> document</dt> - <dd>General information on tests for interoperability between various - IPsec implementations. This includes links to several test sites.</dd> - <dt><a href="interop.html">interoperation</a> document.</dt> - <dd>More specific information on FreeS/WAN interoperation with other - implementations.</dd> - <dt><a href="performance.html">performance</a> document</dt> - <dd>performance measurements</dd> -</dl> - -<p>The test setups and procedures described here can also be used in other -testing, but this document focuses on testing the IPsec functionality of -FreeS/WAN.</p> - -<H2><A NAME="test.oe">Testing opportunistic connections</A></H2> - -<P>This section teaches you how to test your opportunistically encrypted (OE) -connections. To set up OE, please see the easy instructions in our -<A HREF="quickstart.html">quickstart guide</A>.</P> - -<H3>Basic OE Test</H3> - - -<P>This test is for basic OE functionality. -<!-- You may use it on an -<A HREF="quickstart.html#oppo.client">initiate-only OE</A> box or a -<A HREF="quickstart.html#opp.incoming">full OE</A> box. --> -For additional tests, keep reading.</P> - -<P>Be sure IPsec is running. You can see whether it is with:</P> -<PRE> ipsec setup status</PRE> -<P>If need be, you can restart it with:</P> -<PRE> service ipsec restart</PRE> - -<P>Load a FreeS/WAN test website from the host on which you're running -FreeS/WAN. Note: the feds may be watching these sites. Type one of:<P> -<PRE> links oetest.freeswan.org</PRE> -<PRE> links oetest.freeswan.nl</PRE> -<!--<PRE> links oetest.freeswan.ca</PRE>--> - -<P>A positive result looks like this:</P> - -<PRE> - You seem to be connecting from: 192.0.2.11 which DNS says is: - gateway.example.com - _________________________________________________________________ - - Status E-route - OE enabled 16 192.139.46.73/32 -> 192.0.2.11/32 => - tun0x2097@192.0.2.11 - OE enabled 176 192.139.46.77/32 -> 192.0.2.11/32 => - tun0x208a@192.0.2.11 -</PRE> - -<P>If you see this, congratulations! Your OE box will now encrypt -its own traffic whenever it can. If you have difficulty, -see our <A HREF="#oe.trouble">OE troubleshooting tips</A>. -</P> - -<H3>OE Gateway Test</H3> -<P>If you've set up FreeS/WAN to protect a subnet behind your gateway, -you'll need to run another simple test, which can be done from a machine -running any OS. That's right, your Windows box can be protected by -opportunistic encryption without any FreeS/WAN install or configuration -on that box. From <STRONG>each protected subnet node</STRONG>, -load the FreeS/WAN website with:</P> - -<PRE> links oetest.freeswan.org</PRE> -<PRE> links oetest.freeswan.nl</PRE> - -<P>A positive result looks like this:</P> -<PRE> - You seem to be connecting from: 192.0.2.98 which DNS says is: - box98.example.com - _________________________________________________________________ - - Status E-route - OE enabled 16 192.139.46.73/32 -> 192.0.2.98/32 => - tun0x134ed@192.0.2.11 - OE enabled 176 192.139.46.77/32 -> 192.0.2.11/32 => - tun0x134d2@192.0.2.11 -</PRE> - -<P>If you see this, congratulations! Your OE gateway will now encrypt -traffic for this subnet node whenever it can. If you have difficulty, see our -<A HREF="#oe.trouble">OE troubleshooting tips</A>. -</P> - - -<H3>Additional OE tests</H3> - -<P>When testing OE, you will often find it useful to execute this command -on the FreeS/WAN host:</P> -<PRE> ipsec eroute</PRE> - -<P>If you have established a connection (either for or for a subnet node) -you will see a result like:</P> - -<PRE> 192.0.2.11/32 -> 192.139.46.73/32 => tun0x149f@192.139.46.38 -</PRE> - -<P>Key:</P> -<TABLE> -<TR><TD>1.</TD> - <TD>192.0.2.11/32</TD> - <TD>Local start point of the protected traffic. - </TD></TR> -<TR><TD>2.</TD> - <TD>192.0.2.194/32</TD> - <TD>Remote end point of the protected traffic. - </TD></TR> -<TR><TD>3.</TD> - <TD>192.0.48.38</TD> - <TD>Remote FreeS/WAN node (gateway or host). - May be the same as (2). - </TD></TR> -<TR><TD>4.</TD> - <TD>[not shown]</TD> - <TD>Local FreeS/WAN node (gateway or host), where you've produced the output. - May be the same as (1). - </TD></TR> -</TABLE> - - -<P>For extra assurance, you may wish to use a packet sniffer such as -<A HREF="http://www.tcpdump.org">tcpdump</A> to verify that packets -are being encrypted. You should see output that indicates -<STRONG>ESP</STRONG> encrypted data, - for example:</P> - -<PRE> 02:17:47.353750 PPPoE [ses 0x1e12] IP 154: xy.example.com > oetest.freeswan.org: ESP(spi=0x87150d16,seq=0x55)</PRE> - - - -<h2><a name="test.uml">Testing with User Mode Linux</a></h2> - -<p><a href="http://user-mode-linux.sourceforge.net/">User Mode Linux</a> -allows you to run Linux as a user process on another Linux machine.</p> - -<p>As of 1.92, the distribution has a new directory named testing. It -contains a collection of test scripts and sample configurations. Using these, -you can bring up several copies of Linux in user mode and have them build -tunnels to each other. This lets you do some testing of a FreeS/WAN -configuration on a single machine.</p> - -<p>You need a moderately well-endowed machine for this to work well. Each UML -wants about 16 megs of memory by default, which is plenty for FreeS/WAN -usage. Typical regression testing only occasionally uses as many as 4 UMLs. -If one is doing nothing else with the machine (in particular, not running X -on it), then 128 megs and a 500MHz CPU are fine.</p> - -Documentation on these -scripts is <a href="umltesting.html">here</a>. There is also documentation -on automated testing <A href="makecheck.html">here</a>. - -<h2><a name="testnet">Configuration for a testbed network</a></h2> - -<p>A common test setup is to put a machine with dual Ethernet cards in -between two gateways under test. You need at least five machines; two -gateways, two clients and a testing machine in the middle.</p> - -<p>The central machine both routes packets and provides a place to run -diagnostic software for checking IPsec packets. See next section for -discussion of <a href="#tcpdump.faq">using tcpdump(8)</a> for this.</p> - -<p>This makes things more complicated than if you just connected the two -gateway machines directly to each other, but it also makes your test setup -much more like the environment you actually use IPsec in. Those environments -nearly always involve routing, and quite a few apparent IPsec failures turn -out to be problems with routing or with firewalls dropping packets. This -approach lets you deal with those problems on your test setup.</p> - -<p>What you end up with looks like:</p> - -<h3><a name="testbed">Testbed network</a></h3> -<pre> subnet a.b.c.0/24 - | - eth1 = a.b.c.1 - gate1 - eth0 = 192.168.p.1 - | - | - eth0 = 192.168.p.2 - route/monitor box - eth1 = 192.168.q.2 - | - | - eth0 = 192.168.q.1 - gate2 - eth1 = x.y.z.1 - | - subnet x.y.z.0/24</pre> -<pre>Where p and q are any convenient values that do not interfere with other -routes you may have. The ipsec.conf(5) file then has, among other things:</pre> -<pre>conn abc-xyz - left=192.168.p.1 - leftnexthop=192.168.p.2 - right=192.168.q.1 - rightnexthop=192.168.q.2</pre> - -<p>Once that works, you can remove the "route/monitor box", and connect the -two gateways to the Internet. The only parameters in ipsec.conf(5) that need -to change are the four shown above. You replace them with values appropriate -for your Internet connection, and change the eth0 IP addresses and the -default routes on both gateways.</p> - -<p>Note that nothing on either subnet needs to change. This lets you test -most of your IPsec setup before connecting to the insecure Internet.</p> - -<h3><a name="tcpdump.test">Using packet sniffers in testing</a></h3> - -<p>A number of tools are available for looking at packets. We will discuss -using <a href="http://www.tcpdump.org/">tcpdump(8)</a>, a common Linux tool -included in most distributions. Alternatives offerring more-or-less the same -functionality include:</p> -<dl> - <dt><a href="http://www.ethereal.com">Ethereal</a></dt> - <dd>Several people on our mailing list report a preference for this over - tcpdump.</dd> - <dt><a href="http://netgroup-serv.polito.it/windump/">windump</a></dt> - <dd>a Windows version of tcpdump(8), possibly handy if you have Windows - boxes in your network</dd> - <dt><a - href="http://reptile.rug.ac.be/~coder/sniffit/sniffit.html">Sniffit</a></dt> - <dd>A linux sniffer that we don't know much about. If you use it, please - comment on our mailing list.</dd> -</dl> - -<p>See also this <a -href="http://www.tlsecurity.net/unix/ids/sniffer/">index</a> of packet -sniffers.</p> - -<p>tcpdump(8) may misbehave if run on the gateways themselves. It is designed -to look into a normal IP stack and may become confused if you ask it to -display data from a stack which has IPsec in play.</p> - -<p>At one point, the problem was quite severe. Recent versions of tcpdump, -however, understand IPsec well enough to be usable on a gateway. You can get -the latest version from <a href="http://www.tcpdump.org/">tcpdump.org</a>.</p> - -<p>Even with a recent tcpdump, some care is required. Here is part of a post -from Henry on the topic:</p> -<pre>> a) data from sunset to sunrise or the other way is not being -> encrypted (I am using tcpdump (ver. 3.4) -x/ping -p to check -> packages) - -What *interface* is tcpdump being applied to? Use the -i option to -control this. It matters! If tcpdump is looking at the ipsecN -interfaces, e.g. ipsec0, then it is seeing the packets before they are -encrypted or after they are decrypted, so of course they don't look -encrypted. You want to have tcpdump looking at the actual hardware -interfaces, e.g. eth0. - -Actually, the only way to be *sure* what you are sending on the wire is to -have a separate machine eavesdropping on the traffic. Nothing you can do -on the machines actually running IPsec is 100% guaranteed reliable in this -area (although tcpdump is a lot better now than it used to be).</pre> - -<p>The most certain way to examine IPsec packets is to look at them on the -wire. For security, you need to be certain, so we recommend doing that. To do -so, you need a <strong>separate sniffer machine located between the two -gateways</strong>. This machine can be routing IPsec packets, but it must not -be an IPsec gateway. Network configuration for such testing is discussed <a -href="#testnet">above</a>.</p> - -<p>Here's another mailing list message with advice on using tcpdump(8):</p> -<pre>Subject: RE: [Users] Encrypted??? - Date: Thu, 29 Nov 2001 - From: "Joe Patterson" <jpatterson@asgardgroup.com> - -tcpdump -nl -i $EXT-IF proto 50 - --nl tells it not to buffer output or resolve names (if you don't do that it -may confuse you by not outputing anything for a while), -i $EXT-IF (replace -with your external interface) tells it what interface to listen on, and -proto 50 is ESP. Use "proto 51" if for some odd reason you're using AH, and -"udp port 500" if you want to see the isakmp key exchange/tunnel setup -packets. - -You can also run `tcpdump -nl -i ipsec0` to see what traffic is on that -virtual interface. Anything you see there *should* be either encrypted or -dropped (unless you've turned on some strange options in your ipsec.conf -file) - -Another very handy thing is ethereal (http://www.ethereal.com/) which runs -on just about anything, has a nice gui interface (or a nice text-based -interface), and does a great job of protocol breakdown. For ESP and AH -it'll basically just tell you that there's a packet of that protocol, and -what the spi is, but for isakmp it'll actually show you a lot of the tunnel -setup information (until it gets to the point in the protocol where isakmp -is encrypted....)</pre> - -<h2><a name="verify.crypt">Verifying encryption</a></h2> - -<p>The question of how to verify that messages are actually encrypted has -been extensively discussed on the mailing list. See this <a -href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/07/msg00262.html">thread</a>.</p> - -<p>If you just want to verify that packets are encrypted, look at them with a -packet sniffer (see <a href="#tcpdump.test">previous section</a>) located -between the gateways. The packets should, except for some of the header -information, be utterly unintelligible. <strong>The output of good encryption -looks <em>exactly</em> like random noise</strong>. </p> - -<p>A packet sniffer can only tell you that the data you looked at was -encrypted. If you have stronger requirements -- for example if your security -policy requires verification that plaintext is not leaked during startup or -under various anomolous conditions -- then you will need to devise much more -thorough tests. If you do that, please post any results or methodological -details which your security policy allows you to make public.</p> - -<p>You can put recognizable data into ping packets with something like:</p> -<pre> ping -p feedfacedeadbeef 11.0.1.1</pre> - -<p>"feedfacedeadbeef" is a legal hexadecimal pattern that is easy to pick out -of hex dumps.</p> - -<p>For other protocols, you may need to check if you have encrypted data or -ASCII text. Encrypted data has approximately equal frequencies for all 256 -possible characters. ASCII text has most characters in the printable range -0x20-0x7f, a few control characters less than 0x20, and none at all in the -range 0x80-0xff. 0x20, space, is a good character to look for. In normal -English text space occurs about once in seven characters, versus about once -in 256 for random or encrypted data.</p> - -<p>One thing to watch for: the output of good compression, like that of good -encryption, looks just like random noise. You cannot tell just by looking at -a data stream whether it has been compressed, encrypted, or both. You need a -little care not to mistake compressed data for encrypted data in your -testing.</p> - -<p>Note also that weak encryption also produces random-looking output. You -cannot tell whether the encryption is strong by looking at the output. To be -sure of that, you would need to have both the algorithms and the -implementation examined by experts. </p> - -<p>For IPsec, you can get partial assurance from interoperability tests. See -our <a href="interop.html">interop</a> document. When twenty products all -claim to implement <a href="glossary.html#3DES">3DES</a>, and they all talk -to each other, you can be fairly sure they have it right. Of course, you -might wonder whether all the implementers are consipring to trick you or, -more plausibly, whether some implementations might have "back doors" so they -can get also it wrong when required.. If you're seriously worried about -things like that, you need to get the code you use audited (good luck if it -is not Open Source), or perhaps to talk to a psychiatrist about treatments -for paranoia. </p> - -<h2><a name="mail.test">Mailing list pointers</a></h2> - -<p>Additional information on testing can be found in these <a -href="mail.html">mailing list</a> messages:</p> -<ul> - <li>a user's detailed <a - href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/11/msg00571.html">setup - diary</a> for his testbed network</li> - <li>a FreeS/WAN team member's <a - href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/11/msg00425.html">notes</a> - from testing at an IPsec interop "bakeoff"</li> -</ul> -</body> -</html> diff --git a/doc/src/testingtools.html b/doc/src/testingtools.html deleted file mode 100644 index 491b1956c..000000000 --- a/doc/src/testingtools.html +++ /dev/null @@ -1,188 +0,0 @@ -<html> -<head> -<title>FreeS/WAN survey of testing tools</title> -<!-- Changed by: Michael Richardson, 02-Jan-2002 --> -<meta name="keywords" content="Linux, IPsec, VPN, security, FreeSWAN, testing, nettools"> - -<!-- - -Written by Michael Richardson for the Linux FreeS/WAN project -Freely distributable under the GNU General Public License - -More information at www.freeswan.org -Feedback to users@lists.freeswan.org - -$Id: testingtools.html,v 1.1 2004/03/15 20:35:24 as Exp $ - -$Log: testingtools.html,v $ -Revision 1.1 2004/03/15 20:35:24 as -added files from freeswan-2.04-x509-1.5.3 - -Revision 1.1 2002/03/12 20:57:25 mcr - review of tools used for testing FreeSWAN systems. - - ---> -</head> - -<body> - -<h1>Survey of testing tools</h1> - -<h2><A HREF="http://freshmeat.net/projects/apsend">http://freshmeat.net/projects/apsend</A></h2> - -<P> -About: <A HREF="">APSEND</A> is a TCP/IP packet sender to test firewalls and other -network applications. It also includes a syn flood option, the land -DoS attack, a DoS attack against tcpdump running on a UNIX-based -system, a UDP-flood attack, and a ping flood option. It currently -supports the following protocols: IP, TCP, UDP, ICMP, Ethernet frames -and you can also build any other type of protocol using the generic -option. The scripting language of apsend is already written, but not -yet public. -</P> - -<P> -STATUS: The public web site seems to have died -</P> - -<h2><A HREF="http://freshmeat.net/projects/hping2">http://freshmeat.net/projects/hping2</A></h2> - -<P> -About: <A HREF="http://www.hping.org/">hping2</A> is a network tool -able to send custom ICMP/UDP/TCP packets and to display target replies -like ping does with ICMP replies. It handles fragmentation and -arbitrary packet body and size, and can be used to transfer files -under supported protocols. Using hping2, you can: test firewall rules, -perform [spoofed] port scanning, test net performance using different -protocols, packet size, TOS (type of service), and fragmentation, do -path MTU discovery, tranfer files (even between really Fascist -firewall rules), perform traceroute-like actions under different -protocols, fingerprint remote OSs, audit a TCP/IP stack, etc. hping2 -is a good tool for learning TCP/IP. -</P> - -<P> -This utility has rather complicated usage and no man page at present. -The documentation is supposed to be in HPING2-HOWTO, but that file -seems to be absent. -</P> - -<h2><A HREF="http://freshmeat.net/projects/icmpush">http://freshmeat.net/projects/icmpush</A></h2> - -<P> -About: ICMPush is a tool that send ICMP packets fully customized from command -line. This release supports the ICMP error types Unreach, Parameter -Problem, Redirect and Source Quench and the ICMP information types -Timestamp, Address Mask Request, Information Request, Router -Solicitation, Router Advertisement and Echo Request. Also supports -ip-spoofing, broadcasting and other useful features. It's really a -powerful program for testing and debugging TCP/IP stacks and networks. -</P> - -<P> -</P> - -<h2><A HREF="http://freshmeat.net/projects/isic">http://freshmeat.net/projects/isic</A></h2> - -<P> -ISIC sends randomly generated packets to a target computer. Its -primary uses are to stress-test an IP stack, to find leaks in a -firewall, and to test the implementation of IDSes and firewalls. The -user can specify how often the packets will be frags, have IP options, -TCP options, an urgent pointer, etc. Programs for TCP, UDP, ICMP, -IP w/ random protocols, and random ethernet frames are included. -</P> - -<h2><A HREF="http://freshmeat.net/projects/sendpacket">http://freshmeat.net/projects/sendpacket</A></h2> - -<P> -Send Packet is a small but powerful program to test how your network -responds to specific packet content. Via a config file and/or command -line parameters, you can forge (modify the headers of) your own -TCP/UDP/ICMP/IP packets and send them through your network. Also, -following the Easy Sniffer modular philosophy, you can specify wich -modules you'd like to build. -</P> - -<h2><A HREF="http://freshmeat.net/projects/aicmpsend/">http://freshmeat.net/projects/aicmpsend/</A></h2> - -<P> -AICMPSEND is an ICMP sender with many features including ICMP -flooding and spoofing. All ICMP flags and codes are implemented. You -can use this program for various DoS attacks, for ICMP flooding and -to test firewalls. -</P> - -<h2><A HREF="http://freshmeat.net/projects/sendip/">http://freshmeat.net/projects/sendip/</A></h2> - -<P> -SendIP is a command-line tool to send arbitrary IP packets. It has a -large number of options to specify the content of every header of a -RIP, TCP, UDP, ICMP, or raw IPv4/IPv6 packet. It also allows any data -to be added to the packet. Checksums can be calculated automatically, -but if you wish to send out wrong checksums, that is supported too. -</P> - -<h2><A HREF="http://laurent.riesterer.free.fr/gasp/index.html">http://laurent.riesterer.free.fr/gasp/index.html</A></h2> - -<P> -GASP stands for 'Generator and Analyzer System for Protocols'. It -allows you to decode and encode any protocols you specify. -</P> - -<P> -The main use is probably to test networks applications : you can -construct packets by hand and test the behavior of your program when -facing some strange packets. But you can image a lot of other -application : e.g. manipulating graphical file or executable -headers. Just describe the specification of the structured data. -</P> - -<P> -GASP is divided in two parts : a compiler which take the specification -of the protocols and generate the code to handle it, this code is a -new Tcl command as GASP in build upon Tcl/Tk and extends the scripting -facilities provided by Tcl. -</P> - -<h2><A HREF="http://pdump.lucidx.com/">http://pdump.lucidx.com/</A></h2> -<h2><A HREF="http://freshmeat.net/projects/aps/">http://freshmeat.net/projects/aps/</A></h2> -<h2><A HREF="http://freshmeat.net/projects/netsed/">http://freshmeat.net/projects/netsed/</A></h2> -<h2><A HREF="http://www.via.ecp.fr/~bbp/netsh/">http://www.via.ecp.fr/~bbp/netsh/</A></h2> -<h2><A HREF="http://www.elxsi.de/">http://www.elxsi.de/</A></h2> -<h2><A HREF="http://www.laurentconstantin.com/us/lcrzo/">http://www.laurentconstantin.com/us/lcrzo/</A></h2> -<h2><A HREF="http://www.joedog.org/libping/index.html">http://www.joedog.org/libping/index.html</A></h2> -<h2><A HREF="http://feynman.mme.wilkes.edu/projects/xNetTools/">http://feynman.mme.wilkes.edu/projects/xNetTools/</A></h2> -<h2><A HREF="http://freshmeat.net/projects/pktsrc/">http://freshmeat.net/projects/pktsrc/</A></h2> -<h2><A HREF="http://freshmeat.net/projects/lcrzoex/">http://freshmeat.net/projects/lcrzoex/</A></h2> -<h2><A HREF="http://freshmeat.net/projects/rain/">http://freshmeat.net/projects/rain/</A></h2> -<P> -rain is a powerful packet builder for testing the stability of -hardware and software. Its features include support for all IP -protocols and the ability to fully customize the packets it sends. -</P> - -<P>(Note, this is not the same as /usr/games/rain)</P> - -<h2><A HREF="http://freshmeat.net/projects/libnet">http://freshmeat.net/projects/libnet</A></h2> -<h2><A HREF="http://freshmeat.net/projects/pftp">http://freshmeat.net/projects/pftp</A></h2> -<h2><A HREF="http://freshmeat.net/projects/pung">http://freshmeat.net/projects/pung</A></h2> - -<P> -pung is a simple server tester. It tries to connect via TCP/IP to a -server but does not transfer any data. It is meant to be used in -scripts that check a list of servers, helping to detect certain common -problems. -</P> - -<h2><A HREF="http://freshmeat.net/projects/thesunpacketshell">http://freshmeat.net/projects/thesunpacketshell</A></h2> -<h2><A HREF="http://freshmeat.net/projects/webperformancetrainer">http://freshmeat.net/projects/webperformancetrainer</A></h2> -<h2><A HREF="http://sourceforge.net/projects/va-ctcs">http://sourceforge.net/projects/va-ctcs</A></h2> -<h2><A HREF="http://synscan.nss.nu/programs.php">http://synscan.nss.nu/programs.php</A></h2> -<h2><A HREF="http://sourceforge.net/projects/va-ctcs">http://sourceforge.net/projects/va-ctcs</A></h2> -<h2><A HREF="http://freshmeat.net/projects/ettercap/">http://freshmeat.net/projects/ettercap/</A></h2> -<h2><A HREF="http://www.dtek.chalmers.se/~d3august/xt/index.html">http://www.dtek.chalmers.se/~d3august/xt/index.html</A></h2> -<h2><A HREF="http://www.opersys.com/LTT/">http://www.opersys.com/LTT/</A></h2> -<h2><A HREF="http://packetstorm.securify.com/DoS/indexdate.shtml">http://packetstorm.securify.com/DoS/indexdate.shtml</A></h2> -<H2> <A HREF="http://comnet.technion.ac.il/~cn1w02/">TCP/IP noise simulator</A></H2> diff --git a/doc/src/trouble.html b/doc/src/trouble.html deleted file mode 100644 index 604264c01..000000000 --- a/doc/src/trouble.html +++ /dev/null @@ -1,840 +0,0 @@ -<HTML> -<HEAD> - <TITLE>FreeS/WAN troubleshooting</TITLE> - <meta name="keywords" content="Linux, IPSEC, VPN, security, FreeSWAN, troubleshooting, debugging"> -<!-- - Written by Claudia Schmeing for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - -CVS information: -RCS ID: $Id: trouble.html,v 1.1 2004/03/15 20:35:24 as Exp $ -Last changed: $Date: 2004/03/15 20:35:24 $ -Revision number: $Revision: 1.1 $ - -CVS revision numbers do not correspond to FreeS/WAN release numbers. ---> - -</HEAD> -<BODY> - -<H1><A NAME="trouble"></A>Linux FreeS/WAN Troubleshooting Guide</H1> - -<H2><A NAME="overview"></A>Overview</H2> - -<P> -This document covers several general places where you might have a problem:</P> -<OL> - <LI><A HREF="#install">During install</A>.</LI> - <LI><A HREF="#negotiation">During the negotiation process</A>.</LI> - <LI><A HREF="#use">Using an established connection</A>.</LI> -</OL> -<P>This document also contains <A HREF="#notes">notes</A> which -expand on points made in these sections, and tips for -<A HREF="#prob.report">problem -reporting</A>. If the other end of your connection is not FreeS/WAN, -you'll also want to read our -<A HREF="interop.html#interop.problem">interoperation</A> document.</P> -<H2><A NAME="install"></A>1. During Install</H2> -<H3>1.1 RPM install gotchas</H3> -<P>With the RPM method:</P> -<UL> -<LI>Be sure you have installed both the userland tools and the kernel - components. One will not work without the other. For example, when using - FreeS/WAN-produced RPMs for our 2.04 release, you need both: -<PRE> freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm - freeswan-module-2.04_2.4.20_20.9-0.i386.rpm -</PRE> -</LI> -</UL> -<H3>1.2 Problems installing from source</H3> -<P>When installing from source, you may find these problems:</P> -<UL> - <LI>Missing library. See <A HREF="faq.html#gmp.h_missing">this</A> - FAQ.</LI> - <LI>Missing utilities required for compile. See this - <A HREF="install.html#tool.lib">checklist</A>.</LI> - <LI>Kernel version incompatibility. See <A HREF="faq.html#k.versions">this</A> - FAQ.</LI> - <LI>Another compile problem. Find information in the out.* files, - ie. out.kpatch, out.kbuild, created at compile time in the top-level - Linux FreeS/WAN directory. Error messages generated by KLIPS during - the boot sequence are accessible with the <VAR>dmesg</VAR> command. - <BR> - Check the list archives and the List in Brief to see if this is a - known issue. If it is not, report it to the bugs list as described - in our <A HREF="#prob.report">problem reporting</A> section. In some - cases, you may be asked to provide debugging information using gdb; - details <A HREF="#gdb">below</A>.</LI> - <LI>If your kernel compiles but you fail to install your new - FreeS/WAN-enabled kernel, review the sections on <A HREF="install.html#newk">installing - the patched kernel</A>, and <A HREF="install.html#testinstall">testing</A> - to see if install succeeded.</LI> -</UL> -<H3><A NAME="install.check"></A>1.3 Install checks</H3> -<P><VAR>ipsec verify</VAR> checks a number -of FreeS/WAN essentials. Here are some hints on what do to when your -system doesn't check out:</P> -<P> -<TABLE border=1> -<TR> -<TD><STRONG>Problem</STRONG></TD> -<TD><STRONG>Status</STRONG></TD> -<TD><STRONG>Action</STRONG></TD> -</TR> -<TR> -<TD><VAR>ipsec</VAR> not on-path</TD> -<TD> </TD> -<TD><P>Add <VAR>/usr/local/sbin</VAR> to your PATH.</P></TD> -</TR> -<TR> -<TD>Missing KLIPS support</TD> -<TD><FONT COLOR="#FF0000">critical</FONT></TD> -<TD>See <A HREF="faq.html#noKLIPS">this FAQ.</A></TD> -</TR> -<TR> -<TD>No RSA private key</TD> -<TD> </TD> -<TD> -<P>Follow <A HREF="install.html#genrsakey">these -instructions</A> to create an RSA key pair for your host. RSA keys are:</P> -<UL> -<LI>required for opportunistic encryption, and</LI> -<LI>our preferred method to authenticate pre-configured connections.</LI> -</UL> -</TD> -</TR> -<TR> -<TD><VAR>pluto</VAR> not running</TD> -<TD><FONT COLOR="#FF0000">critical</FONT></TD> -<TD><PRE>service ipsec start</PRE></TD> -</TR> -<TR> -<TD>No port 500 hole</TD> -<TD><FONT COLOR="#FF0000">critical</FONT></TD> -<TD>Open port 500 for IKE negotiation.</TD> -</TR> -<TR> -<TD>Port 500 check N/A</TD> -<TD> </TD> -<TD>Check that port 500 is open for IKE negotiation.</TD> -</TR> -<TR> -<TD>Failed DNS checks</TD> -<TD> </TD> -<TD>Opportunistic encryption requires information from DNS. -To set this up, see <A HREF="quickstart.html#opp.setup">our instructions</A>. -</TD> -</TR> -<TR> -<TD>No public IP address</TD> -<TD> </TD> -<TD>Check that the interface which you want to protect with IPSec is up and -running.</TD> -</TR> -</TABLE> - - -<H3><A NAME="oe.trouble"></A>1.3 Troubleshooting OE</H3> -<P>OE should work with no local configuration, if you have posted -DNS TXT records according to the instructions in our -<A HREF="quickstart.html">quickstart guide</A>. -If you encounter trouble, try these hints. -We welcome additional hints via the -<A HREF="mail.html">users' mailing list</A>.</P> - -<TABLE border=1> -<TR> -<TD><STRONG>Symptom</STRONG></TD> -<TD><STRONG>Problem</STRONG></TD> -<TD><STRONG>Action</STRONG></TD> -</TR> -<TR> -<TD> -You're running FreeS/WAN 2.01 (or later), -and initiating a connection to FreeS/WAN -2.00 (or earlier). -In your logs, you see a message like: -<pre>no RSA public key known for '192.0.2.13'; -DNS search for KEY failed (no KEY record -for 13.2.0.192.in-addr.arpa.)</pre> -The older FreeS/WAN logs no error. -</TD> -<TD> -<A NAME="oe.trouble.flagday"></A> -A protocol level incompatibility between 2.01 (or later) and -2.00 (or earlier) causes this error. It occurs when a FreeS/WAN 2.01 -(or later) box for which no KEY record is posted attempts to initiate an OE -connection to older FreeS/WAN versions (2.00 and earlier). -Note that older versions can initiate to newer versions without this error. -</TD> -<TD>If you control the peer host, upgrade its FreeS/WAN to 2.01 (or later), and -post new style TXT records for it. If not, but if you know its sysadmin, -perhaps a quick note is in order. If neither option is possible, you can -ease the transition by posting an old style KEY record (created with a -command like "ipsec showhostkey --key") to the reverse map for -the FreeS/WAN 2.01 (or later) box.</TD> -</TR> -<TR> -<TD>OE host is very slow to contact other hosts.</TD> -<TD>Slow DNS service while running OE.</TD> -<TD>It's a good idea to run a caching DNS server on your OE host, -as outlined in <A HREF="http://lists.freeswan.org/pipermail/design/2003-January/004205.html">this -mailing list message</A>. If your DNS servers are elsewhere, -put their IPs -in the <VAR>clear</VAR> policy group, and -re-read groups with <PRE>ipsec auto --rereadgroups</PRE> -</TD> -</TR> -<TR> -<TD> -<PRE>Can't Opportunistically initiate for -192.0.2.2 to 192.0.2.3: no TXT record -for 13.2.0.192.in-addr.arpa.</PRE> -</TD> -<TD>Peer is not set up for OE.</TD> -<TD><P>None. Plenty of hosts on the Internet -do not run OE. If, however, you have set OE up on that peer, this may -indicate that you need to wait up to 48 hours -for its DNS records to propagate.</P></TD> -</TR> -<TR> -<TD><VAR>ipsec verify</VAR> does not find DNS records: -<PRE>... -Looking for TXT in forward map: - xy.example.com...[FAILED] -Looking for TXT in reverse map...[FAILED] -...</PRE> - -You also experience authentication failure:<BR> -<PRE>Possible authentication failure: -no acceptable response to our -first encrypted message</PRE> -</TD> - -<TD>DNS records are not posted or have not propagated.</TD> -<TD>Did you post the DNS records necessary for OE? If not, -do so using the instructions in our -<A HREF="quickstart.html#quickstart">quickstart guide</A>. -If so, wait up to 48 hours for the DNS records to propagate.</TD> -</TR> -<TR> -<TD><VAR>ipsec verify</VAR> does not find DNS records, and you experience -authentication failure.</TD> -<TD>For iOE, your ID -does not match location of -forward DNS record.</TD> -<TD>In <VAR>config setup</VAR>, change -<VAR>myid=</VAR> to match the forward DNS where you posted the record. -Restart FreeS/WAN. - For reference, see our -<A HREF="quickstart.html#opp.client">iOE instructions</A>.</TD> -</TR> -<TR> -<TD><VAR>ipsec verify</VAR> finds DNS records, yet there is -still authentication failure. ( ? )</TD> -<TD>DNS records are malformed.</TD> -<TD>Re-create the records and send new copies to your DNS administrator.</TD> -</TR> -<TR> -<TD><VAR>ipsec verify</VAR> finds DNS records, yet there is -still authentication failure. ( ? )</TD> -<TD>DNS records show different keys for a gateway vs. its subnet hosts.</TD> -<TD>All TXT records for boxes protected by an OE gateway must contain the -gateway's public key. Re-create and re-post any incorrect records using -<A HREF="quickstart.html#opp.incoming">these instructions</A>.</TD> -</TR> -<TR> -<TD>OE gateway loses connectivity to its subnet. The gateway's -routing table shows routes to the subnet through IPsec interfaces.</TD> -<TD>The subnet is part of the <VAR>private</VAR> or <VAR>block</VAR> -policy group on the gateway.</TD> -<TD>Remove the subnet from the group, and reread -groups with <PRE>ipsec auto --rereadgroups</PRE></TD> -</TR> -<TR> -<TD>OE does not work to hosts on the local LAN.</TD> -<TD>This is a known issue.</TD> -<TD>See <A HREF="opportunism.known-issues">this list</A> of known issues -with OE. -</TD> -</TR> - -<TR> -<TD>FreeS/WAN does not seem to be executing your default policy. In your -logs, you see a message like: -<PRE>/etc/ipsec.d/policies/iprivate-or-clear" -line 14: subnet "0.0.0.0/0", -source 192.0.2.13/32, -already "private-or-clear"</PRE> -</TD> -<TD><A HREF="glossary.html#fullnet">Fullnet</A> in a policy group file defines -your default policy. Fullnet should normally be present in only one policy -group file. The fine print: you can have two default policies defined so long -as they protect different local endpoints (e.g. the FreeS/WAN gateway and a -subnet).</TD> -<TD> -Find all policies which contain fullnet with:<br> -<PRE>grep -F 0.0.0.0/0 /etc/ipsec.d/policies/*</PRE> -then remove the unwanted occurrence(s). -</TD> -</TR> - -</TABLE> - - -<H2><A NAME="negotiation"></A>2. During Negotiation</H2> -<P>When you fail to bring up a tunnel, you'll need to find out:</P> -<UL> -<LI><A HREF="#state">what your connection state is,</A> and often</LI> -<LI><A HREF="#find.pluto.error">an error message</A>.</LI> -</UL> -<P>before you can -<A HREF="#interpret.pluto.error">diagnose your problem</A>.</P> -<H3><A NAME="state"></A>2.1 Determine Connection State</H3> -<H4>Finding current state</H4> -<P>You can see connection states (STATE_MAIN_I1 and so on) when you -bring up a connection on the command line. If you have missed this, -or brought up your connection automatically, use: -</P> -<PRE>ipsec auto --status</PRE> -<P>The most relevant state is the last one reached.</P> -<H4><VAR>What's this supposed to look like?</VAR></H4> -<P>Negotiations should proceed though various states, in the processes of:</P> -<OL> -<LI>IKE negotiations (aka Phase 1, Main Mode, STATE_MAIN_*)</LI> -<LI>IPSEC negotiations (aka Phase 2, Quick Mode, STATE_QUICK_*)</LI> -</OL> -<P>These are done and a connection is established when you see messages like:</P> -<PRE> 000 #21: "myconn" STATE_MAIN_I4 (ISAKMP SA established)... - 000 #2: "myconn" STATE_QUICK_I2 (sent QI2, IPsec SA established)...</PRE><P> -Look for the key phrases are "ISAKMP SA established" and "IPSec -SA established", with the relevant connection name. Often, this happens -at STATE_MAIN_I4 and STATE_QUICK_I2, respectively.</P> -<P><VAR>ipsec auto --status</VAR> will tell you what states <STRONG>have -been achieved</STRONG>, rather than the current state. Since -determining the current state is rather more difficult to do, current -state information is not available from Linux FreeS/WAN. If you are -actively bringing a connection up, the status report's last states -for that connection likely reflect its current state. Beware, though, -of the case where a connection was correctly brought up but is now -downed: Linux FreeS/WAN will not notice this until it attempts to -rekey. Meanwhile, the last known state indicates that the connection -has been established.</P> -<P>If your connection is stuck at STATE_MAIN_I1, skip straight to -<A HREF="#ikepath">here</A>. - -<H3><A NAME="find.pluto.error"></A>2.2 Finding error text</H3> -<P>Solving most errors will require you to find verbose error text, -either on the command line or in the logs.</P> -<H4>Verbose start for more information</H4> -<P> -Note that you can get more detail from <VAR>ipsec auto</VAR> using -the --verbose flag:</P> -<PRE STYLE="margin-bottom: 0.2in"> ipsec auto --verbose --up west-east</PRE><P> -More complete information can be gleaned from the <A HREF="#logusage">log -files</A>.</P> - -<H4>Debug levels count</H4> -<P>The amount of description you'll get here depends on ipsec.conf debug -settings, <VAR>klipsdebug</VAR>= and <VAR>plutodebug</VAR>=. -When troubleshooting, set at least one of these to <VAR>all</VAR>, and -when done, reset it to <VAR>none</VAR> so your logs don't fill up. -Note that you must have enabled the <VAR>klipsdebug</VAR> -<A HREF="install.html#allbut">compile-time option</A> for the -<VAR>klipsdebug</VAR> configuration switch to work.</P> -<P>For negotiation problems <VAR>plutodebug</VAR> is most relevant. -<VAR>klipsdebug</VAR> applies mainly to attempts to use an -already-established connection. See also <A HREF="ipsec.html#parts">this</A> -description of the division of duties within Linux FreeS/WAN.</P> -<P>After raising your debug levels, restart Linux FreeS/WAN to ensure -that ipsec.conf is reread, then recreate the error to generate -verbose logs. -</P> -<H4><VAR>ipsec barf</VAR> for lots of debugging information</H4> -<P> -<A HREF="manpage.d/ipsec_barf.8.html"><VAR>ipsec barf (8)</VAR></A> -collects a bunch of useful debugging information, including these logs -Use the command</P> -<PRE> - ipsec barf > barf.west -</PRE> -<P>to generate one.</P> -<H4>Find the error</H4> -<P>Search out the failure point in your logs. - Are there a handful of lines which succinctly describe how -things are going wrong or contrary to your expectation? Sometimes the -failure point is not immediately obvious: Linux FreeS/WAN's errors -are usually not marked "Error". Have a look in the -<A HREF="faq.html">FAQ</A> -for what some common failures look like.</P> -<P>Tip: problems snowball. -Focus your efforts on the first problem, which is likely to be the -cause of later errors.</P> -<H4>Play both sides</H4> -<P>Also find error text on the peer IPSec box. -This gives you two perspectives on the same failure.</P> -<P>At times you will require information which only one side has. -The peer can merely indicate the presence of an error, and its -approximate point in the negotiations. If one side keeps retrying, -it may be because there is a show stopper on the other side. -Have a look at the other side and figure out what it doesn't like.</P> -<P>If the other end is not Linux FreeS/WAN, the principle is the -same: replicate the error with its most verbose logging on, and -capture the output to a file.</P> -<H3><A NAME="interpret.pluto.error"></A>2.3 Interpreting a Negotiation Error</H3> -<H4><A NAME="ikepath"></A>Connection stuck at STATE_MAIN_I1</H4> -<P>This error commonly happens because IKE (port 500) packets, needed -to negotiate an IPSec connection, cannot travel freely between your IPSec -gateways. See <A HREF="firewall.html#packets">our firewall document</A> -for details.</P> -<H4>Other errors</H4> -<P>Other errors require a bit more digging. Use the following resources:</P> -<UL> - <LI><A HREF="faq.html">the FAQ</A> . Since this document is - constantly updated, the snapshot's FAQ may have a new entry relevant - to your problem.</LI> - <LI>our <A HREF="background.html">background document</A> . - Special considerations which, while not central to Linux FreeS/WAN, - are often tripped over. Includes problems with - <a href="background.html#MTU.trouble">packet fragmentation</a>, - and considerations for - testing opportunism.</LI> - <LI>the <A HREF="mail.html#lists">list archives</A>. Each of the - searchable archives works differently, so it's worth checking each. - Use a search term which is generic, but identifies your error, for - example "No connection is known for". - <BR> - Often, you will find that your question has been answered in the - past. Finding an archived answer is quicker than asking the list. - You may, however, find similar questions without answers. If you do, - send their URLs to the list with your trouble report. The additional - examples may help the list tech support person find your answer.</LI> - <LI>Look into the code where the error is being generated. The - pluto code is nicely documented with comments and meaningful - variable names.</LI> -</UL> -<P>If you have failed to solve your problem with the help of these -resources, send a detailed problem report to the users list, -following these <A HREF="#prob.report">guidelines</A>.</P> -<H2><A NAME="use"></A>3. Using a Connection</H2> -<H3>3.1 Orienting yourself</H3> -<H4><VAR>How do I know if it works?</VAR></H4> -<P>Test your connection by sending packets through it. The simplest way -to do this is with ping, but the ping needs to <STRONG>test the correct -tunnel.</STRONG> See <A HREF="#testgates">this example scenario</A> if -you don't understand this.<P> -<P>If your ping returns, test any other connections you've brought -u all check out, great. You may wish to <A HREF="#bigpacket">test -with large packets</A> for MTU problems.</P> -<H4><VAR>ipsec barf</VAR> is useful again</H4> -<P>If your ping fails to return, generate an ipsec barf debugging -report on each IPSec gateway. On a non-Linux FreeS/WAN -implementation, gather equivalent information. Use this, and the tips -in the next sections, to troubleshoot. Are you sure that both -endpoints are capable of hearing and responding to ping?</P> -<H3>3.2 Those pesky configuration errors</H3> -<P>IPSec may be dropping your ping packets since they do not belong in the -tunnels you have constructed:</P> -<UL> -<LI>Your ping may not test the tunnel you intend to test. For details, see our -<A HREF="faq.html#cantping">"I can't ping"</A> FAQ. -</LI> -<LI> -Alternately, you may have a configuration error. -For example, you may have configured one of the four possible tunnels between -two gateways, but not the one required to secure the important -traffic you're now testing. In this case, add and start the tunnel, -and try again. -</LI> -</UL> -<P>In either case, you will often see a message like:</P> -<PRE>klipsdebug... no eroute</PRE> -<P>which we discuss in <A HREF="faq.html#no_eroute">this -FAQ</A>.</P> -<P>Note:</P> -<UL> -<LI><A HREF="glossary.html#NAT.gloss">Network Address Translation (NAT)</A> -and <A HREF="glossary.html#masq">IP masquerade</A> may have an effect on -which tunnels you need to configure.</LI> -<LI>When testing a tunnel that protects a multi-node subnet, try several -subnet nodes as ping targets, in case one node is routing incorrectly.</LI> -</UL> -<H3><A NAME="route.firewall"></A>3.3 Check Routing and Firewalling</H3> -<P>If you've confirmed your configuration assumptions, the problem is -almost certainly with routing or firewalling. Isolate the problem -using interface statistics, firewall statistics, or a packet sniffer.</P> -<H4>Background:</H4> -<UL> - <LI>Linux FreeS/WAN supplies all the special routing it needs; - you need only route packets out through your IPSec gateway. Verify - that on the <VAR>subnetted</VAR> machines you are using for your - ping-test, your routing is as expected. I have seen a tunnel - "fail" because the subnet machine sending packets - out an alternate gateway (not our IPSec gateway) on their return path. - <LI>Linux FreeS/WAN requires particular <A HREF="firewall.html"> - firewalling considerations</A>. - Check the firewall rules on your IPSec gateways and ensure that they - allow IPSec traffic through. Be sure that no other machine - for - example a router between the gateways - is blocking your IPSec - packets. -</UL> -<H4><A NAME="ifconfig"></A>View Interface and Firewall -Statistics</H4> -<P>Interface reports and firewall statistics can help you track down -lost packets at a glance. Check any firewall statistics you may be keeping -on your IPSec gateways, for dropped packets.</P> - -<P><STRONG>Tip</STRONG>: You can take a snapshot of the packets processed -by your firewall with:</P> - -<PRE> iptables -L -n -v</PRE> - -<P>You can get creative with "diff" to find out what happens to a -particular packet during transmission.</P> - -<P>Both <VAR>cat /proc/net/dev</VAR> and <VAR>ifconfig</VAR> display -interface statistics, and both are included in <VAR>ipsec barf</VAR>. Use -either to check if any interface has dropped packets. If you find -that one has, test whether this is related to your ping. While you -ping continuously, print that interface's statistics several times. -Does its drop count increase in proportion to the ping? If so, check -why the packets are dropped there.</P> - -<P>To do this, look at the firewall rules that apply to that interface. If the -interface is an IPSec interface, more information may be available in -the log. Grep for the word "drop" in a log which was -created with <VAR>klipsdebug=all</VAR> as the error happened.</P> -<P>See also this <A HREF="#ifconfig1">discussion</A> on interpreting -<VAR>ifconfig</VAR> statistics.</P> -<H3><A NAME="sniff"></A>3.4 When in doubt, sniff it out</H3> -<P>If you have checked configuration assumptions, routing, and -firewall rules, and your interface statistics yield no clue, it -remains for you to investigate the mystery of the lost packet by the -most thorough method: with a packet sniffer (providing, of course, -that this is legal where you are working). -<P>In order to detect packets on the ipsec virtual interfaces, -you will need an up-to-date sniffer (tcpdump, ethereal, ksnuffle) on -your IPSec gateway machines. You may also find it useful to sniff the ping -endpoints.</P> -<H4>Anticipate your packets' path</H4> -<P>Ping, and examine each interface along the projected path, checking for your -ping's arrival. If it doesn't get to the the next stop, you have narrowed -down where to look for it. In this way, you can isolate a problem area, -and narrow your troubleshooting focus.</P> -<P>Within a machine running Linux FreeS/WAN, this -<A HREF="firewall.html#packets">packet flow diagram</A> will help you -anticipate a packet's path. -<P>Note that:</P> -<UL> -<LI> -from the perspective of the tunneled packet, the entire tunnel is one hop. -That's explained in <A HREF="faq.html#no_trace">this</A> FAQ. -</LI> -<LI> - an encapsulated IPSec packet will look different, when -sniffed, from the plaintext packet which generated it. You -can see plaintext packets entering an IPSec interface and the -resulting cyphertext packets as they emerge from the corresponding -physical interface. -</LI> -</UL> -<P>Once you isolate where the packet is lost, take a closer look at -firewall rules, routing and configuration assumptions as they affect -that specific area. If the packet is lost on an IPSec gateway, comb -through <VAR>klipsdebug</VAR> output for anomalies. -</P> -<P>If the packet goes through both gateways successfully and reaches -the ping target, but does not return, suspect routing. Check that the -ping target routes packets back to the IPSec gateway.</P> -<H3><A NAME="find.use.error"></A>3.5 Check your logs</H3> -<P>Here, too, log information can be useful. Start with the -<A HREF="#find.pluto.error">guidelines above</A>.</P> -<P>For connection use problems, set <VAR>klipsdebug=all</VAR>. Note -that you must have enabled the <VAR>klipsdebug</VAR> -<A HREF="install.html#allbut">compile-time option</A> to do this. -Restart Linux FreeS/WAN so that it rereads <VAR>ipsec.conf</VAR>, -then recreate the error condition. When searching through -<VAR>klipsdebug</VAR> data, look especially for the keywords -"drop" (as in dropped packets) and "error".</P> -<P>Often the problem with connection use is not software error, but -rather that the software is behaving contrary to expectation. -</P> -<H4><A NAME="interpret.use.error"></A>Interpreting log text</H4> -<P>To interpret the Linux FreeS/WAN log text you've found, use the -same resources as indicated for troubleshooting -connection negotiation: -<A HREF="faq.html">the FAQ</A> , our -<A HREF="background.html">background document</A>, and the -<A HREF="mail.html#lists">list archives</A>. -Looking in the KLIPS code is only for the very brave.</P> -<P>If you are still stuck, send a <A HREF="#prob.report">detailed -problem report</A> to the users' list.</P> -<H3><A NAME="bigpacket"></A>3.6 More testing for the truly thorough</H3> -<H4>Large Packets</H4> -<P>If each of your connections passed the ping test, you may wish to -test by pinging with large packets (2000 bytes or larger). If it does -not return, suspect MTU issues, and see this <A HREF="background.html#MTU.trouble">discussion</A>.</P> -<H4>Stress Tests</H4> -<P>In most users' view, a simple ping test, and perhaps a -large-packet ping test suffice to indicate a working IPSec -connection.</P> -<P>Some people might like to do additional stress tests prior to -production use. They may be interested in this <A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/12/msg00224.html">testing -protocol</A> we use at interoperation conferences, aka "bakeoffs". -We also have a <VAR>testing</VAR> directory that ships with the -release.</P> -<H2><A NAME="prob.report"></A>4. Problem Reporting</H2> -<H3>4.1 How to ask for help</H3> -<P>Ask for troubleshooting help on the users' mailing list, -<A HREF="mailto:users@lists.freeswan.org">users@lists.freeswan.org</A>. -While sometimes an initial query with a quick description of your -intent and error will twig someone's memory of a similar problem, -it's often necessary to send a second mail with a complete problem -report. -</P> - - -<P>When reporting problems to the mailing list(s), please include: -</P> -<UL> - <LI>a brief description of the problem</LI> - <LI>if it's a compile problem, the actual output from make, - showing the problem. Try to edit it down to only the relevant part, - but when in doubt, be as complete as you can. If it's a kernel - compile problem, any relevant out.* files</LI> - <LI>if it's a run-time problem, pointers to where we can find the - complete output from "ipsec barf" from BOTH ENDS (not just - one of them). Remember that it's common outside the US and Canada to - pay for download volume, so if you can't post barfs on the web and - send the URL to the mailing list, at least compress them with tar or - gzip.<BR> - If you can, try to simplify the case that is causing the problem. - In particular, if you clear your logs, start FreeS/WAN with no other - connections running, cause the problem to happen, and then do <VAR>ipsec - barf</VAR> on both ends immediately, that gives the smallest and - least cluttered output.</LI> - <LI>any other error messages, complaints, etc. that you saw. - Please send the complete text of the messages, not just a summary.</LI> - <LI>what your network setup is. Include subnets, gateway - addresses, etc. A schematic diagram is a - good format for this information.</LI> - <LI>exactly what you were trying to do with Linux FreeS/WAN, and - exactly what went wrong</LI> - <LI>a fix, if you have one. But remember, you are sending mail to - people all over the world; US residents and US citizens in - particular, please read doc/exportlaws.html before sending code -- - even small bug fixes -- to the list or to us.</LI> - <LI>When in doubt about whether to include some seemingly-trivial - item of information, include it. It is rare for problem reports to - have too much information, and common for them to have too little.</LI> -</UL> - -<P>Here are some good general guidelines on bug reporting: -<a href="http://tuxedo.org/~esr/faqs/smart-questions.html">How To Ask Questions -The Smart Way</a> and <a -href="http://www.chiark.greenend.org.uk/~sgtatham/bugs.html">How to Report -Bugs Effectively</a>.</p> - - -<H3>4.2 Where to ask</H3> -<P>To report a problem, send mail about it to the users' list. If you -are certain that you have found a bug, report it to the bugs list. If -you encounter a problem while doing your own coding on the Linux -FreeS/WAN codebase and think it is of interest to the design team, -notify the design list. When in doubt, default to the users' list. -More information about the mailing lists is found <A HREF="mail.html#lists">here</A>.</P> -<P>For a number of reasons -- including export-control regulations -affecting almost any <STRONG>private</STRONG> discussion of -encryption software -- we prefer that problem reports and discussions -go to the lists, not directly to the team. Beware that the list goes -worldwide; US citizens, read this important information about your -<A HREF="politics.html#exlaw">export laws</A>. If you're using this -software, you really should be on the lists. To get onto them, visit -<A HREF="http://lists.freeswan.org/">lists.freeswan.org</A>.</P> -<P>If you do send private mail to our coders or want a private reply -from them, please make sure that the return address on your mail -(From or Reply-To header) is a valid one. They have more important -things to do than to unravel addresses that have been mangled in an -attempt to confuse spammers. -</P> -<H2><A NAME="notes"></A>5. Additional Notes on Troubleshooting</H2> -<P>The following sections supplement the Guide: <A HREF="#system.info">information -available on your system</A>; <A HREF="#testgates">testing between -security gateways</A>; <A HREF="#ifconfig1">ifconfig reports for -KLIPS debugging</A>; <A HREF="#gdb">using GDB on Pluto</A>.</P> -<H3><A NAME="system.info"></A>5.1 Information available on your -system</H3> -<H4><A NAME="logusage"></A>Logs used</H4> -<P>Linux FreeS/WAN logs to:</P> -<UL> - <LI>/var/log/secure (or, on Debian, /var/log/auth.log)</LI> - <LI>/var/log/messages</LI> -</UL> -<P>Check both places to get full information. If you find nothing, -check your <VAR>syslogd.conf(5)</VAR> to see where your -/etc/syslog.conf or equivalent is directing <VAR>authpriv</VAR> -messages.</P> -<H4><A NAME="pages"></A>man pages provided</H4> -<DL> - <DT><A HREF="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</A> - </DT><DD> - Manual page for IPSEC configuration file. - </DD><DT> - <A HREF="manpage.d/ipsec.8.html">ipsec(8)</A> - </DT><DD STYLE="margin-bottom: 0.2in"> - Primary man page for ipsec utilities. - </DD></DL> -<P> -Other man pages are on <A HREF="manpages.html">this list</A> and in</P> -<UL> - <LI>/usr/local/man/man3</LI> - <LI>/usr/local/man/man5</LI> - <LI>/usr/local/man/man8/ipsec_*</LI> -</UL> -<H4><A NAME="statusinfo"></A>Status information</H4> -<DL> - <DT>ipsec auto --status - </DT><DD> - Command to get status report from running system. Displays Pluto's - state. Includes the list of connections which are currently "added" - to Pluto's internal database; lists state objects reflecting ISAKMP - and IPsec SAs being negotiated or installed. - </DD><DT> - ipsec look - </DT><DD> - Brief status info. - </DD><DT> - ipsec barf - </DT><DD STYLE="margin-bottom: 0.2in"> - Copious debugging info. - </DD></DL> -<H3> -<A NAME="testgates"></A>5.2 Testing between security gateways</H3> -<P>Sometimes you need to test a subnet-subnet tunnel. This is a -tunnel between two security gateways, which protects traffic on -behalf of the subnets behind these gateways. On this network:</P> -<PRE> Sunset==========West------------------East=========Sunrise - IPSec gateway IPSec gateway - local net untrusted net local net</PRE><P> -you might name this tunnel sunset-sunrise. You can test this tunnel -by having a machine behind one gateway ping a machine behind the -other gateway, but this is not always convenient or even possible.</P> -<P>Simply pinging one gateway from the other is not useful. Such a -ping does not normally go through the tunnel. <STRONG>The tunnel -handles traffic between the two protected subnets, not between the -gateways</STRONG> . Depending on the routing in place, a ping might</P> -<UL> - <LI>either succeed by finding an - unencrypted route</LI> - <LI>or fail by finding no route. Packets without an IPSEC eroute - are discarded.</LI> -</UL> -<P><STRONG>Neither event tells you anything about the tunnel</STRONG>. -You can explicitly create an eroute to force such packets through the -tunnel, or you can create additional tunnels as described in our -<A HREF="config.html#multitunnel">configuration document</A>, but -those may be unnecessary complications in your situation.</P> -<P>The trick is to explicitly test between <STRONG>both gateways' -private-side IP addresses</STRONG>. Since the private-side interfaces -are on the protected subnets, the resulting packets do go via the -tunnel. Use either ping -I or traceroute -i, both of which allow you -to specify a source interface. (Note: unsupported on older Linuxes). -The same principles apply for a road warrior (or other) case where -only one end of your tunnel is a subnet.</P> -<H3><A NAME="ifconfig1"></A>5.3 ifconfig reports for KLIPS debugging</H3> -<P>When diagnosing problems using ifconfig statistics, you may wonder -what type of activity increments a particular counter for an ipsecN -device. Here's an index, posted by KLIPS developer Richard Guy -Briggs:</P> -<PRE>Here is a catalogue of the types of errors that can occur for which -statistics are kept when transmitting and receiving packets via klips. -I notice that they are not necessarily logged in the right counter. -. . . - -Sources of ifconfig statistics for ipsec devices - -rx-errors: -- packet handed to ipsec_rcv that is not an ipsec packet. -- ipsec packet with payload length not modulo 4. -- ipsec packet with bad authenticator length. -- incoming packet with no SA. -- replayed packet. -- incoming authentication failed. -- got esp packet with length not modulo 8. - -tx_dropped: -- cannot process ip_options. -- packet ttl expired. -- packet with no eroute. -- eroute with no SA. -- cannot allocate sk_buff. -- cannot allocate kernel memory. -- sk_buff internal error. - - -The standard counters are: - -struct enet_statistics -{ - int rx_packets; /* total packets received */ - int tx_packets; /* total packets transmitted */ - int rx_errors; /* bad packets received */ - int tx_errors; /* packet transmit problems */ - int rx_dropped; /* no space in linux buffers */ - int tx_dropped; /* no space available in linux */ - int multicast; /* multicast packets received */ - int collisions; - - /* detailed rx_errors: */ - int rx_length_errors; - int rx_over_errors; /* receiver ring buff overflow */ - int rx_crc_errors; /* recved pkt with crc error */ - int rx_frame_errors; /* recv'd frame alignment error */ - int rx_fifo_errors; /* recv'r fifo overrun */ - int rx_missed_errors; /* receiver missed packet */ - - /* detailed tx_errors */ - int tx_aborted_errors; - int tx_carrier_errors; - int tx_fifo_errors; - int tx_heartbeat_errors; - int tx_window_errors; -}; - -of which I think only the first 6 are useful.</PRE><H3> -<A NAME="gdb"></A>5.4 Using GDB on Pluto</H3> -<P>You may need to use the GNU debugger, gdb(1), on Pluto. This -should be necessary only in unusual cases, for example if you -encounter a problem which the Pluto developer cannot readily -reproduce or if you are modifying Pluto. -</P> -<P>Here are the Pluto developer's suggestions for doing this: -</P> -<PRE>Can you get a core dump and use gdb to find out what Pluto was doing -when it died? - -To get a core dump, you will have to set dumpdir to point to a -suitable directory (see <A HREF="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</A>). - -To get gdb to tell you interesting stuff: - $ script - $ cd dump-directory-you-chose - $ gdb /usr/local/lib/ipsec/pluto core - (gdb) where - (gdb) quit - $ exit - -The resulting output will have been captured by the script command in -a file called "typescript". Send it to the list. - -Do not delete the core file. I may need to ask you to print out some -more relevant stuff.</PRE><P> -Note that the <VAR>dumpdir</VAR> parameter takes effect only when the -IPsec subsystem is restarted -- reboot or ipsec setup restart.</P> -<P><BR><BR> -</P> -</BODY> -</HTML> diff --git a/doc/src/uml-rhroot-list.txt b/doc/src/uml-rhroot-list.txt deleted file mode 100644 index 198997032..000000000 --- a/doc/src/uml-rhroot-list.txt +++ /dev/null @@ -1,91 +0,0 @@ -filesystem-2.1.6-2 -glibc-common-2.2.4-13 -slang-1.4.4-4 -newt-0.50.33-1 -mktemp-1.5-11 -syslinux-1.52-2 -which-2.12-3 -zlib-devel-1.1.3-24 -ntsysv-1.2.24-1 -db1-devel-1.85-7 -e2fsprogs-1.23-2 -iputils-20001110-6 -mingetty-0.9.4-18 -pwdb-0.61.1-3 -bash-2.05-8 -bzip2-1.0.1-4 -libstdc++-2.96-98 -logrotate-3.5.9-1 -rootfiles-7.2-1 -bash-doc-2.05-8 -iproute-2.2.4-14 -ncurses-5.2-12 -diffutils-2.7.2-2 -findutils-4.1.7-1 -gzip-1.3-15 -readline-4.2-2 -tmpwatch-2.8-2 -cpio-2.4.2-23 -gawk-3.1.0-3 -less-358-21 -procps-X11-2.0.7-11 -sed-3.02-10 -vim-minimal-5.8-7 -fileutils-4.1-4 -sysklogd-1.4.1-4 -mount-2.11g-5 -rpm-4.0.3-1.03 -glib-devel-1.2.10-5 -bzip2-libs-1.0.1-4 -tar-1.13.19-6 -cracklib-dicts-2.7-12 -passwd-0.64.1-7 -pam-devel-0.75-14 -SysVinit-2.78-19 -krb5-libs-1.2.2-13 -pam_krb5-1.46-1 -krbafs-utils-1.0.9-2 -setup-2.5.7-1 -basesystem-7.0-2 -glibc-2.2.4-13 -popt-1.6.3-1.03 -setuptool-1.8-2 -shadow-utils-20000902-4 -zlib-1.1.3-24 -chkconfig-1.2.24-1 -db1-1.85-7 -db3-3.2.9-4 -file-3.35-2 -losetup-2.11g-5 -net-tools-1.60-3 -netconfig-0.8.11-7 -libtermcap-2.0.8-28 -libtermcap-devel-2.0.8-28 -bzip2-devel-1.0.1-4 -libstdc++-devel-2.96-98 -modutils-2.4.6-4 -crontabs-1.10-1 -MAKEDEV-3.2-5 -grep-2.4.2-7 -psmisc-20.1-2 -readline-devel-4.2-2 -e2fsprogs-devel-1.23-2 -ed-0.2-21 -vim-common-5.8-7 -procps-2.0.7-11 -redhat-release-7.2-1 -time-1.7-14 -cracklib-2.7-12 -console-tools-19990829-36 -textutils-2.0.14-2 -dev-3.2-5 -glib-1.2.10-5 -termcap-11.0.1-10 -info-4.0b-3 -words-2-17 -pam-0.75-14 -util-linux-2.11f-9 -sh-utils-2.0.11-5 -initscripts-6.40-1 -krbafs-1.0.9-2 -krbafs-devel-1.0.9-2 diff --git a/doc/src/uml-rhroot.html b/doc/src/uml-rhroot.html deleted file mode 100644 index ca05a2073..000000000 --- a/doc/src/uml-rhroot.html +++ /dev/null @@ -1,116 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> -<HTML> - <HEAD> - <TITLE>Building a RedHat root image</TITLE> - <!-- Created by: Michael Richardson, 22-Nov-2001 --> - <!-- Changed by: Michael Richardson, 22-Nov-2001 --> - - - </HEAD> - <BODY> - <H1>Building a RedHat root image</H1> - -<P> -The image required to use User-Mode-Linux is just a normal set of executables. -These can be extracted from a RedHat distribution using the following proceedure. -</P> - -<P> -There is a script in testing/utils called <CODE>uml-rhroot.sh</CODE>. It takes -two arguments: -<UL> -<LI> a directory in which to put resulting directory tree. -<LI> a directory tree containing the RedHat distribution RPMs. This may be - in one of three forms: -<UL> -<LI> a directory containing the directories "disc1" and "disc2". These - could be ISO images that are mounted loopback via, for instance: -<PRE> -<CODE> -mkdir -p /distros/redhat/7.2/disc1 /distros/redhat/7.2/disc1 -mount -t iso9660 -o loop,ro /distros/redhat/7.2/enigma-i386-disc1.iso /distros/redhat/7.2/disc1 -mount -t iso9660 -o loop,ro /distros/redhat/7.2/enigma-i386-disc2.iso /distros/redhat/7.2/disc2 -</CODE> -</PRE> -or even two real CDroms mounted somewhere. In the example above, use "/distros/redhat/7.2" as the distribution directory. -</LI> -<LI> a directory containing a "merged" disc1 and disc2 as suggested by RedHat in <A HREF="http://www.redhat.com/docs/manuals/linux/RHL-7.2-Manual/install-guide/s1-install-network.html#S2-INSTALL-SETUPSERVER">http://www.redhat.com/docs/manuals/linux/RHL-7.2-Manual/install-guide/s1-install-network.html under "Setting up the Server"</A>. -<LI> a directory containing all the required RPMs. (See <A HREF="uml-rhroot-list7.2.txt">list of RPMs</A>)</LI> -</UL> -</UL> -</P> - -<P>The unpacked distribution will take approximately 133Mb. You will - want to locate this on the same partition as your intended root - trees for your User-Mode-Linux's as this will permit hard links to - be used, saving disk space. -</P> - -<P> - Because the RPM command used uses the chroot(2) system call and - needs to change ownership of the files that it creates, it must be - run as root. Afterward, you should chown the entire directory to the - userid that you will be using for testing (i.e. probably - yours). It should eventually suffices to make sure that you can read - every file. -</P> - -<P> -You should be able to chroot to this directory and run programs. If -you can not at least run ls, then there is a problem. -</P> -<P> -Expect a couple of errors about install-info. -</P> - -<P> -An example: -<PRE> -<CODE> -Script started on Thu Nov 22 15:51:15 2001 -cassidy:/c2/user-mode-linux# df -Filesystem 1k-blocks Used Available Use% Mounted on -/dev/hda1 3844408 1673528 1975584 46% / -/dev/hda3 12495048 1823404 10036884 16% /home -/dev/hdc1 10325748 805056 8996172 9% /c1 -/dev/hdc2 10325780 4815160 4986100 50% /c2 -/dev/hdc3 10325780 2972480 6828780 31% /c3 -/dev/hdc4 7495084 3059640 4054704 44% /c4 -/distros/redhat/7.2/enigma-i386-disc1.iso - 662072 662072 0 100% /distros/redhat/7.2/disc1 -/distros/redhat/7.2/enigma-i386-disc2.iso - 653740 653740 0 100% /distros/redhat/7.2/disc2 -cassidy:/c2/user-mode-linux# /c2/freeswan/sandbox-main/testing/utils/uml-rhroot.sh -Usage: /c2/freeswan/sandbox-main/testing/utils/uml-rhroot.sh rootdir cdimagedir -cassidy:/c2/user-mode-linux# /c2/freeswan/sandbox-main/testing/utils/uml-rhroot.sh /c2/user-mode-linux/rpm-root/root /distros/redhat/7.2 -Assuming RH disc1 at /distros/redhat/7.2/disc1/RedHat/RPMS - and disc2 at /distros/redhat/7.2/disc2/RedHat/RPMS -/var/tmp/rpm-tmp.99149: /sbin/install-info: No such file or directory -error: execution of %post scriptlet from textutils-2.0.14-2 failed, exit status 127 -cat: /proc/mounts: No such file or directory -warning: /var/lib/rpm/Basenames created as /var/lib/rpm/Basenames.rpmnew -warning: /var/lib/rpm/Conflictname created as /var/lib/rpm/Conflictname.rpmnew -warning: /var/lib/rpm/Group created as /var/lib/rpm/Group.rpmnew -warning: /var/lib/rpm/Name created as /var/lib/rpm/Name.rpmnew -warning: /var/lib/rpm/Packages created as /var/lib/rpm/Packages.rpmnew -warning: /var/lib/rpm/Providename created as /var/lib/rpm/Providename.rpmnew -warning: /var/lib/rpm/Requirename created as /var/lib/rpm/Requirename.rpmnew -warning: /var/lib/rpm/Triggername created as /var/lib/rpm/Triggername.rpmnew -You should now chown it to yourself. -cassidy:/c2/user-mode-linux# chown -R mcr rpm-root/root -cassidy:/c2/user-mode-linux# ls rpm-root/root -bin dev home lib opt root tmp var -boot etc initrd mnt proc sbin usr -cassidy:/c2/user-mode-linux# chroot rpm-root/root -cassidy:/# ls -bin dev home lib opt root tmp var -boot etc initrd mnt proc sbin usr -cassidy:/# exit -cassidy:/c2/user-mode-linux# exit -Script done on Thu Nov 22 15:54:33 2001 -</CODE> -</PRE> - - - </BODY> -</HTML>
\ No newline at end of file diff --git a/doc/src/uml-stack-trace.html b/doc/src/uml-stack-trace.html deleted file mode 100644 index 1b08ed7d1..000000000 --- a/doc/src/uml-stack-trace.html +++ /dev/null @@ -1,129 +0,0 @@ -<PRE> -To: Michael Richardson <mcr@sandelman.ottawa.on.ca> -Cc: user-mode-linux-devel@lists.sourceforge.net -From: Jeff Dike <jdike@karaya.com> -Subject: [uml-devel] Re: stack trace -Date: Mon, 16 Sep 2002 22:36:06 -0500 - -mcr@sandelman.ottawa.on.ca said: -> Can you post (on list or web site) a "script" output of you trying to -> get the right stack out of a stuck uml (tracing myself)...? - -Yup. Here we go... - -Here, I attach to the tracing thread and get the stack of the current thread, -which happens to be the idle thread. - -um 1013: gdb linux 14936 -GNU gdb 5.0rh-5 Red Hat Linux 7.1 -Copyright 2001 Free Software Foundation, Inc. -GDB is free software, covered by the GNU General Public License, and you are -welcome to change it and/or distribute copies of it under certain conditions. -Type "show copying" to see the conditions. -There is absolutely no warranty for GDB. Type "show warranty" for details. -This GDB was configured as "i386-redhat-linux"... -/home/jdike/linux/2.4/um/14936: No such file or directory. -Attaching to program: /home/jdike/linux/2.4/um/linux, process 14936 -0xa014efe9 in __wait4 () - -# This is how you get the current task in the tracing thread - get_current() -# only works in a kernel thread. -(gdb) p (struct task_struct *)cpu_tasks[0].task -$2 = (struct task_struct *) 0xa01c0000 - -# Get the host pid of that task. -(gdb) p $2.thread.extern_pid -$3 = 14939 - -# Get the current ip and sp. -(gdb) shell cat /proc/14939/stat -14939 (linux) T 14936 14936 883 34816 14936 64 5 3 806 7 62 12 0 0 9 0 0 2 -588043 142770176 5008 4294967295 2684358656 2686348640 3221223520 2686205764 - sp ^^^^^^^^^^ - 2685727185 73728 201392128 167776768 268444672 3222308129 0 0 17 0 -ip ^^^^^^^^^^ - -# the sp and ip are items 4 and 5 after the 4294967295 (on 2.2 hosts, that's -2^31 - 1 rather than 2^32 - 1). - -(gdb) p/x 2686205764 -$4 = 0xa01c3f44 -(gdb) p/x 2685727185 -$5 = 0xa014f1d1 - -# Where's the ip? -(gdb) i sym 0xa014f1d1 -nanosleep + 17 in section .text - -# look at the stack around the sp -(gdb) x/32x 0xa01c3f30 -0xa01c3f30 : 0x00000000 0x00000000 0xa01c3f60 0xa00020a8 -0xa01c3f40 : 0x00000004 0xa012e891 0xa01c3f58 0xa01c3f58 -0xa01c3f50 : 0xa01c3f70 0xa0023667 0x00000009 0x3b023380 -0xa01c3f60 : 0xa01c3fa0 0xa012a21d 0x0000000a 0xa01c0000 -0xa01c3f70 : 0xa01c3fa0 0xa012a213 0x00000003 0x00000024 -0xa01c3f80 : 0xa01c3fa0 0xa0011bc4 0xa012b25c 0x00000000 -0xa01c3f90 : 0xa01c3fb0 0x00000000 0xa01c3ffc 0x0000000d -0xa01c3fa0 : 0xa01c3fb0 0xa000c50e 0xa01812e0 0xa01c3ffc - -# The trick here is to locate a frame near the current sp. You're looking -# for a consecutive pair of longwords (fp, ip) having the properties that: -# fp is on the current kernel stack and points further up it -# ip is a text address (if you can't recognize a UML text address by -# sight, print out &_stext and &_etext) -# -# Starting at 0xa01c3f44, the first pair of works satisfying these requirements -# is at 0xa01c3f50. -# So, print that pair out as hex. -(gdb) p/x *((int (*)[2])0xa01c3f50) -$9 = {0xa01c3f70, 0xa0023667} - -# Now, we start climbing the stack. -(gdb) p/x *((int (*)[2])$[0]) -$10 = {0xa01c3fa0, 0xa012a213} -(gdb) -$11 = {0xa01c3fb0, 0xa000c50e} -(gdb) -$12 = {0xa01c3fc0, 0xa000356d} -(gdb) -$13 = {0xa01c3fd0, 0xa013082f} -(gdb) -$14 = {0xa01c3ff0, 0xa012fbdd} -# Stop when you see a NULL frame pointer or gdb bitches at you. -(gdb) -$15 = {0x0, 0xa01513aa} - -# Now we get the symbolic version of the stack with 'i sym' of the second item -# in each pair. -(gdb) i sym 0xa0023667 -check_pgt_cache + 23 in section .text -(gdb) i sym 0xa012a213 -cpu_idle + 123 in section .text -(gdb) i sym 0xa000c50e -rest_init + 46 in section .text -(gdb) i sym 0xa000356d -start_kernel + 361 in section .text.init -(gdb) i sym 0xa013082f -start_kernel_proc + 63 in section .text -(gdb) i sym 0xa012fbdd -signal_tramp + 209 in section .text -(gdb) i sym 0xa01513aa -thread_start + 4 in section .text - -# You can also get line number information with 'i line'. -(gdb) i line *0xa012a213 -Line 488 of "process_kern.c" starts at address 0xa012a213 <cpu_idle+123> - and ends at 0xa012a21d <cpu_idle+133>. -(gdb) - - -------------------------------------------------------- -Sponsored by: AMD - Your access to the experts on Hammer Technology! -Open Source & Linux Developers, register now for the AMD Developer -Symposium. Code: EX8664 http://www.developwithamd.com/developerlab -_______________________________________________ -User-mode-linux-devel mailing list -User-mode-linux-devel@lists.sourceforge.net -https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel - -</PRE>
\ No newline at end of file diff --git a/doc/src/umltesting.html b/doc/src/umltesting.html deleted file mode 100644 index df62a9ae2..000000000 --- a/doc/src/umltesting.html +++ /dev/null @@ -1,478 +0,0 @@ -<html> -<head> -<title>FreeS/WAN User-Mode-Linux testing guide</title> -<!-- Changed by: Michael Richardson, 05-Mar-2003 --> -<meta name="keywords" content="Linux, IPsec, VPN, security, FreeSWAN, testing, User-Mode-Linux, UML"> - -<!-- - -Written by Michael Richardson for the Linux FreeS/WAN project -Freely distributable under the GNU General Public License - -More information at www.freeswan.org -Feedback to users@lists.freeswan.org - -$Id: umltesting.html,v 1.1 2004/03/15 20:35:24 as Exp $ - -$Log: umltesting.html,v $ -Revision 1.1 2004/03/15 20:35:24 as -added files from freeswan-2.04-x509-1.5.3 - -Revision 1.23 2003/09/18 15:12:11 dhr - -fix link to kernel.org mirrors page - -Revision 1.22 2003/03/07 03:49:25 dhr - -fix recommended version of uml-patch - -Revision 1.21 2003/03/06 08:37:03 dhr - -capture more of MCR's knowledge about BIND - -Revision 1.20 2003/03/06 02:15:44 mcr - added note about need for bind9. - -Revision 1.19 2003/03/05 23:20:39 mcr - updates from -47 to -53. - -Revision 1.18 2003/02/27 08:25:48 dhr - -update to reflect newer umlfreeroot - -Revision 1.17 2003/02/27 08:16:45 dhr - -make clear what is the latest version of the UML patch that we've used - -Revision 1.16 2003/02/21 01:35:31 mcr - updated latest umlfreeroot to 15.1. - -Revision 1.15 2003/01/21 03:26:34 mcr - updated documentation on UML state. - -Revision 1.14 2002/11/11 16:43:35 mcr - adjusted formatting of uml_netjig notes. - -Revision 1.13 2002/11/08 10:13:05 mcr - updated documentation for 2.4.19 - -Revision 1.12 2002/11/03 23:44:23 mcr - fixed some formatting in umltesting.html - added some notes about NETJIGWAITUSER re: having tests - prompt before they exit. Helps with debugging. - -Revision 1.11 2002/10/31 19:01:31 mcr - documentation for RUN_*_SCRIPT. - -Revision 1.10 2002/09/15 23:57:59 dhr - -update suggested umlfreeroot - -Revision 1.9 2002/09/15 19:28:05 mcr - added some comments about problems with UMLs. - -Revision 1.8 2002/09/11 20:00:25 mcr - updated umlroot rev to 8.0. - -Revision 1.7 2002/09/09 21:37:43 mcr - updated document to reference currently working kernel+UML. - -Revision 1.6 2002/08/02 22:43:35 mcr - added section on debugging with UMLs. - -Revision 1.5 2002/05/30 18:47:57 dhr - -Update from experience: -- fixed HTML bugs -- restructure slightly -- added another intro paragraph -- mentioned lack of Super User requirements -- added tcpdump build and install procedure -- added uml utils build procedure -- added invitation to try "make check" -- fixed minor typos and mistakes - -Revision 1.4 2002/03/12 21:10:37 mcr - removed instruction on downloading umlminishare, as this is - now simply included in umlrootXXX. reformated some other text. - -Revision 1.3 2002/01/29 02:21:21 mcr - updated instructions for 2.4.17, and for newest UMLroot. - -Revision 1.2 2001/11/27 05:24:09 mcr - added reference to uml-rhroot, but commented out. - This proceedure is not yet ready for prime time. - -Revision 1.1 2001/11/05 04:35:57 mcr - adapted text from design list posting into HTML for Sandy. - - ---> -</head> - -<body> - -<h1><a name="umltesting">User-Mode-Linux Testing guide</a></h1> - -<p> -User mode linux is a way to compile a linux kernel such that it can run as a -process in another linux system (potentially as a *BSD or Windows process -later). See <A HREF="http://user-mode-linux.sourceforge.net/">http://user-mode-linux.sourceforge.net/</A> -</P> - -<p> -UML is a good platform for testing and experimenting with FreeS/WAN. -It allows several network nodes to be simulated on a single machine. -Creating, configuring, installing, monitoring, and controling these -nodes is generally easier and easier to script with UML than real -hardware. -</p> - -<p> -You'll need about 500Mb of disk space for a full sunrise-east-west-sunset -setup. You can possibly get this down by 130Mb if you remove the -sunrise/sunset kernel build. If you just want to run, then you can even -remove the east/west kernel build. -</p> -<p> -Nothing need be done as super user. In a couple of steps, we note -where super user is required to install commands in system-wide -directories, but ~/bin could be used instead. UML seems to use a -system-wide /tmp/uml directory so different users may interfere with -one another. Later UMLs use ~/.uml instead, so multiple users running UML -tests should not be a problem, but note that a single user running -the UML tests will only be able run one set. Further, UMLs sometimes -get stuck and hang around. These "zombies" (most will actually be in -the "T" state in the process table) will interfere with subsequent tests. -</P> -<H2>Preliminary Notes on BIND</H2> - -<P> -As of 2003/3/1, the Light-Weight Resolver is used by pluto. This requires -that BIND9 be running. It also requires that BIND9 development libraries -be present in the build environment. The DNSSEC code is only truly functional -in BIND9 snapshots. The library code could be 9.2.2, we believe. We are -using BIND9 20021115 snapshot code from -<A HREF="ftp://ftp.isc.org/isc/bind9/snapshots">ftp://ftp.isc.org/isc/bind9/snapshots</A>. -</P> -<P> -FreeS/WAN may well require a newer BIND than is on your system. -Many distributions have moved to BIND9.2.2 recently due to a security advisory. -BIND is five components. -</P> -<OL> -<LI> -named -</LI> -<LI> -dnssec-* -</LI> -<LI> -client side resolver libraries -</LI> -<LI> -client side utility libraries -I thought there were lib and named parts to dnsssec... -</LI> -<LI> -dynamic DNS update utilities -</LI> -</OL> -<P> -The only piece that we need for *building* is #4. That's the only part that has to be on the build host. -What is the difference between resolver and util libs? -If you want to edit testing/baseconfigs/all/etc/bind, you'll need a snapshot version. -The resolver library contains the resolver. -FreeS/WAN has its own copy of that in lib/liblwres. -</P> -<H2>Steps to Install UML for FreeS/WAN</H2> -<OL> -<LI> Get the following files: -<OL type="a"> -<LI> from <A HREF="http://www.sandelman.ottawa.on.ca/freeswan/uml/">http://www.sandelman.ottawa.on.ca/freeswan/uml/</A> -umlfreeroot-15.1.tar.gz (or highest numbered one). This is a - debian potato root file system. You can use this even on a Redhat - host, as it has the newer GLIBC2.2 libraries as well. - - -<!-- If you are using - Redhat 7.2 or newer as your development machine, you can create the - image from your installation media. See <A HREF="uml-rhroot.html">Building a RedHat root"></A>. - A future document will explain how to build this from .DEB files as well. ---> - -<!-- -<LI> umlfreesharemini.tar.gz (or umlfreeshareall.tar.gz). - If you are a Debian potato user, you don't need it you can use your - native /usr/share. -</UL> ---> - -<LI> From <A HREF="ftp://ftp.xs4all.nl/pub/crypto/freeswan/">ftp://ftp.xs4all.nl/pub/crypto/freeswan/</A> -a snapshot or release (1.92 or better) - -<LI> From a - <A HREF="http://www.kernel.org/mirrors/">http://www.kernel.org mirror</A>, - the virgin 2.4.19 kernel. Please realize that we have defaults in our - tree for kernel configuration. We try to track the latest UML - kernels. If you use a newer kernel, you may have faults in the - kernel build process. You can see what the latest that is being regularly tested by visiting <A HREF="http://bugs.freeswan.org:81/regress/HEAD/lastgood/freeswan-regress-env.sh">freeswan-regress-env.sh</A>. - -<LI> -<!-- Note: this step is refered to as "step 1d" below. --> -Get - <A HREF="http://ftp.nl.linux.org/uml/">http://ftp.nl.linux.org/uml/</A> - uml-patch-2.4.19-47.bz2 or the one associated with your kernel. - As of 2003/03/05, uml-patch-2.4.19-47.bz2 works for us. -<STRONG>More recent versions of the patch have not been tested by us.</STRONG> -<LI> You'll probably want to visit -<A - HREF="http://user-mode-linux.sourceforge.net">http://user-mode-linux.sourceforge.net</A> -and get the UML utilities. These are not needed for the build or interactive use (but recommended). They are necessary for the regression testing procedures used by "make check". -We currently use uml_utilities_20020212.tar.bz2. -<LI> -You need tcpdump version 3.7.1 or better. -This is newer than the version included in most LINUX distributions. -You can check the version of an installed tcpdump with the --version flag. -If you need a newer tcpdump -fetch both tcpdump and libpcap source tar files from -<A HREF="http://www.tcpdump.org/">http://www.tcpdump.org/</A> or a mirror. -</OL> - -<LI> Pick a suitable place, and extract the following files: -<OL type="a"> -<LI> -<!-- Note: this step is refered to as "step 2a" later. --> -2.4.19 kernel. For instance: -<PRE> -<CODE> - cd /c2/kernel - tar xzvf ../download/pub/linux/kernel/v2.4/linux-2.4.19.tar.gz -</CODE> -</PRE> - -<LI> extract the umlfreeroot file -<!-- (unless you <A HREF="uml-rhroot.html">built your own from RPMs</A>) --> -<PRE> -<CODE> - mkdir -p /c2/user-mode-linux/basic-root - cd /c2/user-mode-linux/basic-root - tar xzvf ../download/umlfreeroot-15.1.tar.gz -</CODE> -</PRE> - -<LI> FreeSWAN itself (or checkout "all" from CVS) -<PRE> -<CODE> - mkdir -p /c2/freeswan/sandbox - cd /c2/freeswan/sandbox - tar xzvf ../download/snapshot.tar.gz -</CODE> -</PRE> -</OL> - -<LI> If you need to build a newer tcpdump: -<UL> -<LI> -Make sure you have OpenSSL installed -- it is needed for cryptographic routines. -<LI> -Unpack libpcap and tcpdump source in parallel directories (the tcpdump -build procedures look for libpcap next door). -<LI> -Change directory into the libpcap source directory and then build the library: -<PRE> -<CODE> - ./configure - make -</CODE> -</PRE> -<LI> -Change into the tcpdump source directory, build tcpdump, and install it. -<PRE> -<CODE> - ./configure - make - # Need to be superuser to install in system directories. - # Installing in ~/bin would be an alternative. - su -c "make install" -</CODE> -</PRE> -</UL> -<LI> If you need the uml utilities, unpack them somewhere then build and install -them: -<PRE> -<CODE> - cd tools - make all - # Need to be superuser to install in system directories. - # Installing in ~/bin would be an alternative. - su -c "make install BIN_DIR=/usr/local/bin" -</CODE> -</PRE> -<LI> set up the configuration file -<UL> -<LI> -<CODE> -cd /c2/freeswan/sandbox/freeswan-1.97/testing/utils -</CODE> -<LI> copy umlsetup-sample.sh to ../../umlsetup.sh: -<CODE> - cp umlsetup-sample.sh ../../umlsetup.sh -</CODE> - -<LI> open up ../../umlsetup.sh in your favorite editor. -<LI> change POOLSPACE= to point to the place with at least 500Mb of -disk. Best if it is on the same partition as the "umlfreeroot" extraction, -as it will attempt to use hard links if possible to save disk space. - -<LI> Set TESTINGROOT if you intend to run the script outside of the - sandbox/snapshot/release directory. Otherwise, it will configure itself. - -<LI> KERNPOOL should point to the directory with your 2.4.19 kernel - tree. This tree should be unconfigured! This is the directory - you used in step 2a. - -<LI> UMLPATCH should point at the bz2 file you downloaded at 1d. - If using a kernel that already includes the patch, set this to /dev/null. - -<LI> FREESWANDIR should point at the directory where you unpacked - the snapshot/release. Include the "freeswan-snap2001sep16b" - or whatever in it. If you are running from CVS, then - you point at the directory where top, klips, etc. are. - The script will fix up the directory so that it can be - used. - -<LI> BASICROOT should be set to the directory used in 2b, or to the directory - that you created with RPMs. - -<LI> SHAREDIR should be set to the directory used in 2c, to /usr/share - for Debian potato users, or to $BASICROOT/usr/share. -</UL> - -<LI> <PRE><CODE> -cd $TESTINGROOT/utils -sh make-uml.sh -</CODE></PRE> - It will grind for awhile. If there are errors it will bail. - If so, run it under "script" and send the output to bugs@lists.freeswan.org. - -<LI> You will have a bunch of stuff under $POOLSPACE. - Open four xterms: - -<PRE><CODE> - for i in sunrise sunset east west - do - xterm -name $i -title $i -e $POOLSPACE/$i/start.sh & - done -</CODE></PRE> - -<LI> Login as root. Password is "root" - (Note, these virtual machines are networked together, but are not - configured to talk to the rest of the world.) - -<LI> verify that pluto started on east/west, run "ipsec look" - -<LI> login to sunrise. run "ping sunset" - -<LI> login to west. run "tcpdump -p -i eth1 -n" - (tcpdump must be version 3.7.1 or newer) - -<LI> Closing a console xterm will shut down that UML. - -<LI> You can "make check", if you want to. -It is run from /c2/freeswan/sandbox/freeswan-1.97.</LI> - -</OL> - -<H1>Debugging the kernel with GDB</H1> - -<P> -With User-Mode-Linux, you can debug the kernel using GDB. -See <HREF="http://user-mode-linux.sourceforge.net/debugging.html">http://user-mode-linux.sourceforge.net/debugging.html</A>. -</P> - -<P> -Typically, one will want to address a test case for a failing situation. -Running GDB from Emacs, or from other front ends is possible. First start GDB. -</P> -<P> -Tell it to open the UMLPOOL/swan/linux program. -</P> -<P> -Note the PID of GDB: -<PRE> -marajade-[projects/freeswan/mgmt/planning] mcr 1029 %ps ax | grep gdb - 1659 pts/9 SN 0:00 /usr/bin/gdb -fullname -cd /mara4/freeswan/kernpatch/UMLPOOL/swan/ linux -</PRE> -</P> - -<P> -Set the following in the environment: -<PRE> -UML_east_OPT="debug gdb-pid=1659" -</PRE> -</P> - -<P> -Then start the user-mode-linux in the test scheme you wish: -<PRE> -marajade-[kernpatch/testing/klips/east-icmp-02] mcr 1220 %../../utils/runme.sh -</PRE> - -The user-mode-linux will stop on boot, giving you a chance to attach to the process: - -<PRE> -(gdb) file linux -Reading symbols from linux...done. -(gdb) attach 1 -Attaching to program: /mara4/freeswan/kernpatch/UMLPOOL/swan/linux, process 1 -0xa0118bc1 in kill () at hostfs_kern.c:770 -</PRE> - -<P> -At this point, break points should be created as appropriate. -</P> - -<H2>Other notes about debugging</H2> - -<P> -If you are running a standard test, after all the packets are sent, the UML will -be shutdown. This can cause problems, because the UML may get terminated while you -are debugging. -</P> -<P> -The environment variable <CODE>NETJIGWAITUSER</CODE> can be set to "waituser". -If so, then the testing system will prompt before exiting the test. -</P> - -<H1>User-Mode-Linux mysteries</H1> - -<UL> -<LI> running more than one UML of the same name (e.g. "west") can cause - problems. -<LI> running more than one UML from the same root file system is not - a good idea. -<LI> all this means that running "make check" twice on the same machine - is probably not a good idea. -<LI> occationally, UMLs will get stuck. This can happen like: -<BLOCK> -15134 ? T 0:00 /spare/hugh/uml/uml2.4.18-sept5/umlbuild/east/linux (east) [/bin/sh] -15138 ? T 0:00 /spare/hugh/uml/uml2.4.18-sept5/umlbuild/east/linux (east) [halt] - </BLOCK> - -these will need to be killed. Note that they are in "T"racing mode. -<LI> UMLs can also hang, and will report "Tracing myself and I can't get out". -This is a bug in UML. There are ways to find out what is going on and -report this to the UML people, but we don't know the magic right now. -</UL> - -<H1>Getting more info from uml_netjig</H1> - -<P> -uml_netjig can be compiled with a built-in tcpdump. This uses not-yet-released -code from <A HREF="http://www.tcpdump.org/">www.tcpdump.org</A>. -Please see the instructions in <CODE>testing/utils/uml_netjig/Makefile</CODE>. -</P> - -</body> -</html> diff --git a/doc/src/upgrading.html b/doc/src/upgrading.html deleted file mode 100644 index 0d6401b96..000000000 --- a/doc/src/upgrading.html +++ /dev/null @@ -1,260 +0,0 @@ -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>Introduction to FreeS/WAN</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, encryption, cryptography, FreeS/WAN, FreeSWAN"> - <!-- - - Written by Claudia Schmeing for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: upgrading.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<A NAME="upgrading"></A><h1>Upgrading to FreeS/WAN 2.x</h1> - - -<H2>New! Built in Opportunistic connections</H2> - -<P>Out of the box, FreeS/WAN 2.x will attempt to encrypt all your IP traffic. -It will try to establish IPsec connections for:</P> -<UL><LI> -IP traffic from the Linux box on which you have installed FreeS/WAN, and</LI> -<LI> -outbound IP traffic routed through that Linux box (eg. from a protected subnet).</LI> -</UL> -<P>FreeS/WAN 2.x uses <STRONG>hidden, automatically enabled - <VAR>ipsec.conf</VAR> connections</STRONG> to do this.</P> - -<P>This behaviour is part of our campaign to get Opportunistic -Encryption (OE) widespread in the Linux world, so that any two Linux boxes can -encrypt to one another without prearrangement. -There's one catch, however: you must <A HREF="quickstart.html#quickstart">set -up a few DNS records</A> -to distribute RSA public keys and (if applicable) IPsec gateway -information.</P> - -<P>If you start FreeS/WAN before you have set up these DNS -records, your connectivity will be slow, and -messages relating to the built in connections will clutter your logs. -If you are unable to set up DNS for OE, you will wish to -<A HREF="policygroups.html#disable_policygroups">disable the -hidden connections</A>.</P> - -<A NAME="upgrading.flagday"></A> - -<H3>Upgrading Opportunistic Encryption -to 2.01 (or later)</H3> - -<P>As of FreeS/WAN 2.01, Opportunistic Encryption (OE) -uses DNS TXT resource records (RRs) only (rather than TXT with KEY). -This change causes a "flag day". -Users of FreeS/WAN 2.00 (or earlier) OE who are upgrading may -need to post additional resource records. -</P> - -<P>If you are running -<A HREF="glossary.html#initiate-only">initiate-only OE</A>, -you <em>must</em> put up a TXT record in any forward domain as per our -<A HREF="quickstart.html#opp.client">quickstart instructions</A>. This -replaces your old forward KEY. -</P> - -<P> -If you are running full OE, you require no updates. You already have -the needed TXT record in the reverse domain. -However, to facilitate future features, you -may also wish to publish that TXT record in a forward domain as -instructed <A HREF="quickstart.html#opp.incoming">here</A>. -</P> - -<P>If you are running OE on a gateway (and encrypting on behalf of subnetted -boxes) you require no updates. -You already have the required TXT record in your gateway's reverse map, -and the TXT records for any subnetted boxes require no updating. -However, to facilitate future features, you may wish to publish your gateway's - TXT record in a forward domain as shown -<A HREF="quickstart.html#opp.incoming">here</A>. - - -<P> -During the transition, you may wish to leave any old KEY records up for -some time. They will provide limited backward compatibility. -<!-- -For more -detail on that compatibility, see <A HREF="oe.known-issues">Known Issues with -OE</A>. ---> -</P> - -<H2>New! Policy Groups</H2> - -<P>We want to make it easy for you to declare security policy as it -applies to IPsec connections.</P> - -<P>Policy Groups make it simple to say: -</P> - -<UL> -<LI>These are the folks I want to talk to in the clear.</LI> -<LI>These spammers' domains -- I don't want to talk to them at all.</LI> -<LI>To talk to the finance department, I must use IPsec.</LI> -<LI>For any other communication, try to encrypt, but it's okay if we can't.</LI></UL> - -<P>FreeS/WAN then implements these policies, creating OE connections -if and when needed. -You can use Policy Groups along with connections you explicitly -define in ipsec.conf.</P> - -<P>For more information, see our -<A HREF="policygroups.html">Policy Group HOWTO</A>.</P> - - -<H2>New! Packetdefault Connection</H2> - -<P>Free/SWAN 2.x ships with the <STRONG>automatically enabled, hidden -connection</STRONG> <VAR>packetdefault</VAR>. This configures -a FreeS/WAN box as an OE gateway for any hosts located -behind it. As mentioned above, you must configure some -<A HREF="quickstart.html">DNS records</A> for -OE to work.</P> -<P>As the name implies, this connection functions as a default. If you -have more specific connections, such as policy groups which configure -your FreeS/WAN box as an OE gateway for a local subnet, these -will apply before <VAR>packetdefault</VAR>. You can view -<VAR>packetdefault</VAR>'s specifics in -<A HREF="manpage.d/ipsec.conf.5.html">man ipsec.conf</A>. -</P> - - -<H2>FreeS/WAN now disables Reverse Path Filtering</H2> - -<P>FreeS/WAN often doesn't work with reverse path filtering. At -start time, FreeS/WAN now turns rp_filter off, and logs a warning.</P> - -<P>FreeS/WAN does not turn it back on again. -You can do this yourself with a command like:</P> - -<PRE> echo 1 > /proc/sys/net/ipv4/conf/eth0/rp_filter</PRE> - -<P>For eth0, substitute the interface which FreeS/WAN was affecting.</P> - - -<A NAME="ipsec.conf_v2"></A><H2>Revised <VAR>ipsec.conf</VAR></H2> - -<H3>No promise of compatibility</H3> - -<P>The FreeS/WAN team promised config-file compatibility throughout -the 1.x series. That means a 1.5 config file can be directly imported into -a fresh 1.99 install with no problems.</P> - -<P>With FreeS/WAN 2.x, we've given ourselves permission to make the config -file easier to use. The cost: some FreeS/WAN 1.x configurations will not -work properly. Many of the new features are, however, backward compatible.</P> - - -<H3>Most <VAR>ipsec.conf</VAR> files will work fine</H3> - -<P>... so long as you paste this line, <STRONG>with no preceding -whitespace</STRONG>, - at the top of your config file: -</P> - -<PRE> version 2</PRE> - -<H3>Backward compatibility patch</H3> - -<P>If the new defaults bite you, use -<A HREF="ipsec.conf.2_to_1"> -this <VAR>ipsec.conf</VAR> fragment</A> to simulate the old default values.</P> - - -<H3>Details</H3> - -<P> -We've obsoleted various directives which almost no one was using: -</P> -<PRE> dump - plutobackgroundload - no_eroute_pass - lifetime - rekeystart - rekeytries</PRE> - -<P>For most of these, there is some other way to elicit the desired behaviour. -See <A HREF="http://lists.freeswan.org/pipermail/design/2002-August/003243.html"> -this post</A>. - -<P> -We've made some settings, which almost everyone was using, defaults. -For example: -</P> - -<PRE> interfaces=%defaultroute - plutoload=%search - plutostart=%search - uniqueids=yes</PRE> - -<P>We've also changed some default values to help with OE and Policy Groups:</P> - -<PRE> authby=rsasig ## not secret!!! - leftrsasigkey=%dnsondemand ## looks up missing keys in DNS when needed. - rightrsasigkey=%dnsondemand</PRE> - -<P> -Of course, you can still override any defaults by explictly declaring something -else in your connection. -</P> - -<P> -<A HREF="http://lists.freeswan.org/pipermail/design/2002-August/003243.html">A post with a list of many ipsec.conf changes.</A><BR> -<A HREF="manpage.d/ipsec.conf.5.html">Current ipsec.conf manual.</A> -</P> - - -<A NAME="upgrading.rpms"></A><H3>Upgrading from 1.x RPMs to 2.x RPMs</H3> - -<P>Note: When upgrading from 1-series to 2-series RPMs, -<VAR>rpm -U</VAR> will not work.</P> - -<P>You must instead erase the 1.x RPMs, then install the 2.x set:</P> -<PRE> rpm -e freeswan</PRE> -<PRE> rpm -e freeswan-module</PRE> - -<P>On erasing, your old <VAR>ipsec.conf</VAR> should be moved to -<VAR>ipsec.conf.rpmsave</VAR>. -Keep this. You will probably want to copy your existing connections to the -end of your new 2.x file.</P> - -<P>Install the RPMs suitable for your kernel version, such as:</P> -<PRE> rpm -ivh freeswan-module-2.04_2.4.20_20.9-0.i386.rpm</PRE> -<PRE> rpm -ivh freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm</PRE> - - - -<P>Or, to splice the files:</P> - -<PRE> cat /etc/ipsec.conf /etc/ipsec.conf.rpmsave > /etc/ipsec.conf.tmp - mv /etc/ipsec.conf.tmp /etc/ipsec.conf</PRE> - -<P>Then, remove the redundant <VAR>conn %default</VAR> and -<VAR>config setup</VAR> -sections. Unless you have done any special configuring here, you'll likely -want to remove the 1.x versions. Remove <VAR>conn OEself</VAR>, if -present.</P> - - - -</body> -</html> diff --git a/doc/src/user_examples.html b/doc/src/user_examples.html deleted file mode 100755 index 5e3784858..000000000 --- a/doc/src/user_examples.html +++ /dev/null @@ -1,322 +0,0 @@ -<html> -<head> -<title>FreeS/WAN examples</title> -<meta name="keywords" content="Linux, IPsec, VPN, security, FreeSWAN, examples"> - -<!-- - -Written by Sandy Harris for the Linux FreeS/WAN project -Freely distributable under the GNU General Public License - -More information at www.freeswan.org -Feedback to users@lists.freeswan.org - -CVS information: -RCS ID: $Id: user_examples.html,v 1.1 2004/03/15 20:35:24 as Exp $ -Last changed: $Date: 2004/03/15 20:35:24 $ -Revision number: $Revision: 1.1 $ - -CVS revision numbers do not correspond to FreeS/WAN release numbers. ---> -</head> - -<body> - -<h1><a name="user.examples">FreeS/WAN script examples</a></h1> - -This file is intended to hold a collection of user-written example -scripts or configuration files for use with FreeS/WAN. -<p> -So far it has only one entry. - -<h2><a name="poltorak">Poltorak's Firewall script</a></h2> - -<pre> -From: Poltorak Serguei <poltorak@dataforce.net> -Subject: [Users] Using FreeS/WAN -Date: Tue, 16 Oct 2001 - -Hello. - -I'm using FreeS/WAN IPsec for half a year. I learned a lot of things about -it and I think it would be interesting for someone to see the result of my -experiments and usage of FreeS/WAN. If you find a mistake in this -file, please e-mail me. And excuse me for my english... I'm learning.. :) - -I'll talk about vary simple configuration: - -addresses prefix = 192.168 - - lan1 sgw1 .0.0/24 (Internet) sgw2 lan2 - .1.0/24---[ .1.1 ; .0.1 ]===================[ .0.10 ; . 2.10 ]---.2.0/24 - - -We need to let lan1 see lan2 across Internet like it is behind sgw1. The -same for lan2. And we need to do IPX bridge for Novel Clients and NDS -synchronization. - -my config: -------------------- ipsec.conf ------------------- -conn lan1-lan2 - type=tunnel - compress=yes - #------------------- - left=192.168.0.1 - leftsubnet=192.168.1.0/24 - #------------------- - right=192.168.0.10 - rightsubnet=192.168.2.0/24 - #------------------- - auth=esp - authby=secret ---------------- end of ipsec.conf ---------------- - -ping .2.x from .1.y (y != 1) -It works?? Fine. Let's continue... - -Why y != 1 ?? Because kernel of sgw1 have 2 IP addresses and it will choose -the first IP (which is used to go to Internet) .0.1 and the packet won't go -through IPsec tunnel :( But if do ping on .1.1 kernel will respond from -that address (.1.1) and the packet will be tunneled. The same problem occurred then -.2.x sends a packet to .1.2 which is down at the moment. What happens? .1.1 -sends ARP requesting .1.2... after 3 tries it send to .2.x an destunreach, -but from his "natural" IP or .0.1 . So the error message won't be delivered! -It's a big problem... - -Resolution... One can manipulate with ipsec0 or ipsec0:0 to solve the -problem (if ipsec0 has .1.1 kernel will send packets correctly), but there -are powerful and elegant iproute2 :) We simply need to change source address -of packet that goes to other secure lan. This is done with - -ip route replace 192.168.2.0/24 via 192.168.0.10 dev ipsec0 src 192.168.1.1 - -Cool!! Now it works!! - -The second step. We want install firewall on sgw1 and sgw2. Encryption of -traffic without security isn't a good idea. I don't use {left|right}firewall, -because I'm running firewall from init scripts. - -We want IPsec data between lan1-lan2, some ICMP errors (destination -unreachable, TTL exceeded, parameter problem and source quench), replying on -pings from both lans and Internet, ipxtunnel data for IPX and of course SSH -between sgw1 and sgw2 and from/to one specified host. - -I'm using ipchains. With iptables there are some changes. - ----------------- rc.firewall --------------------- -#!/bin/sh -# -# Firewall for IPsec lan1-lan2 -# - -IPC=/sbin/ipchains -ANY=0.0.0.0/0 - -# left -SGW1_EXT=192.168.0.1 -SGW1_INT=192.168.1.1 -LAN1=192.168.1.0/24 - -# right -SGW2_EXT=192.168.0.10 -SGW2_INT=192.168.2.10 -LAN2=192.168.2.0/24 - -# SSH from and to this host -SSH_PEER_HOST=_SOME_HOST_ - -# this is for left. exchange these values for right. -MY_EXT=$SGW1_EXT -MY_INT=$SGW1_INT -PEER_EXT=$SGW2_EXT -PEER_INT=$SGW2_INT -INT_IF=eth1 -EXT_IF=eth0 -IPSEC_IF=ipsec0 -MY_LAN=$LAN1 -PEER_LAN=$LAN2 - -$IPC -F -$IPC -P input DENY -$IPC -P forward DENY -$IPC -P output DENY - -# Loopback traffic -$IPC -A input -i lo -j ACCEPT -$IPC -A output -i lo -j ACCEPT - -# for IPsec SGW1-SGW2 -## IKE -$IPC -A input -p udp -s $PEER_EXT 500 -d $MY_EXT 500 -i $EXT_IF -j ACCEPT -$IPC -A output -p udp -s $MY_EXT 500 -d $PEER_EXT 500 -i $EXT_IF -j ACCEPT -## ESP -$IPC -A input -p 50 -s $PEER_EXT -d $MY_EXT -i $EXT_IF -j ACCEPT -### we don't need this line ### $IPC -A output -p 50 -s $MY_EXT -d $PEER_EXT -i $EXT_IF -j ACCEPT -## forward LAN1-LAN2 -$IPC -A forward -s $MY_LAN -d $PEER_LAN -i $IPSEC_IF -j ACCEPT -$IPC -A forward -s $PEER_LAN -d $MY_LAN -i $INT_IF -j ACCEPT -$IPC -A output -s $PEER_LAN -d $MY_LAN -i $INT_IF -j ACCEPT -$IPC -A input -s $PEER_LAN -d $MY_LAN -i $IPSEC_IF -j ACCEPT -$IPC -A input -s $MY_LAN -d $PEER_LAN -i $INT_IF -j ACCEPT -$IPC -A output -s $MY_LAN -d $PEER_LAN -i $IPSEC_IF -j ACCEPT - -# ICMP -# -## Dest unreachable -### from/to Internet -$IPC -A input -p icmp --icmp-type destination-unreachable -s $ANY -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type destination-unreachable -s $MY_EXT -d $ANY -i $EXT_IF -j ACCEPT -### from/to Lan -$IPC -A input -p icmp --icmp-type destination-unreachable -s $ANY -d $MY_INT -i $INT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type destination-unreachable -s $MY_INT -d $ANY -i $INT_IF -j ACCEPT -### from/to Peer Lan -$IPC -A input -p icmp --icmp-type destination-unreachable -s $ANY -d $MY_INT -i $IPSEC_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type destination-unreachable -s $MY_INT -d $ANY -i $IPSEC_IF -j ACCEPT -# -## Source quench -### from/to Internet -$IPC -A input -p icmp --icmp-type source-quench -s $ANY -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type source-quench -s $MY_EXT -d $ANY -i $EXT_IF -j ACCEPT -### from/to Lan -$IPC -A input -p icmp --icmp-type source-quench -s $ANY -d $MY_INT -i $INT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type source-quench -s $MY_INT -d $ANY -i $INT_IF -j ACCEPT -### from/to Peer Lan -$IPC -A input -p icmp --icmp-type source-quench -s $ANY -d $MY_INT -i $IPSEC_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type source-quench -s $MY_INT -d $ANY -i $IPSEC_IF -j ACCEPT -# -## Parameter problem -### from/to Internet -$IPC -A input -p icmp --icmp-type parameter-problem -s $ANY -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type parameter-problem -s $MY_EXT -d $ANY -i $EXT_IF -j ACCEPT -### from/to Lan -$IPC -A input -p icmp --icmp-type parameter-problem -s $ANY -d $MY_INT -i $INT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type parameter-problem -s $MY_INT -d $ANY -i $INT_IF -j ACCEPT -### from/to Peer Lan -$IPC -A input -p icmp --icmp-type parameter-problem -s $ANY -d $MY_INT -i $IPSEC_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type parameter-problem -s $MY_INT -d $ANY -i $IPSEC_IF -j ACCEPT -# -## Time To Live exceeded -### from/to Internet -$IPC -A input -p icmp --icmp-type time-exceeded -s $ANY -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type time-exceeded -s $MY_EXT -d $ANY -i $EXT_IF -j ACCEPT -### to Lan -$IPC -A input -p icmp --icmp-type time-exceeded -s $ANY -d $MY_INT -i $INT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type time-exceeded -s $MY_INT -d $ANY -i $INT_IF -j ACCEPT -### to Peer Lan -$IPC -A input -p icmp --icmp-type time-exceeded -s $ANY -d $MY_INT -i $IPSEC_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type time-exceeded -s $MY_INT -d $ANY -i $IPSEC_IF -j ACCEPT - -# ICMP PINGs -## from Internet -$IPC -A input -p icmp -s $ANY -d $MY_EXT --icmp-type echo-request -i $EXT_IF -j ACCEPT -$IPC -A output -p icmp -s $MY_EXT -d $ANY --icmp-type echo-reply -i $EXT_IF -j ACCEPT -## from LAN -$IPC -A input -p icmp -s $ANY -d $MY_INT --icmp-type echo-request -i $INT_IF -j ACCEPT -$IPC -A output -p icmp -s $MY_INT -d $ANY --icmp-type echo-reply -i $INT_IF -j ACCEPT -## from Peer LAN -$IPC -A input -p icmp -s $ANY -d $MY_INT --icmp-type echo-request -i $IPSEC_IF -j ACCEPT -$IPC -A output -p icmp -s $MY_INT -d $ANY --icmp-type echo-reply -i $IPSEC_IF -j ACCEPT - -# SSH -## from SSH_PEER_HOST -$IPC -A input -p tcp -s $SSH_PEER_HOST -d $MY_EXT 22 -i $EXT_IF -j ACCEPT -$IPC -A output -p tcp \! -y -s $MY_EXT 22 -d $SSH_PEER_HOST -i $EXT_IF -j ACCEPT -## to SSH_PEER_HOST -$IPC -A input -p tcp \! -y -s $SSH_PEER_HOST 22 -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p tcp -s $MY_EXT -d $SSH_PEER_HOST 22 -i $EXT_IF -j ACCEPT -## from PEER -$IPC -A input -p tcp -s $PEER_EXT -d $MY_EXT 22 -i $EXT_IF -j ACCEPT -$IPC -A output -p tcp \! -y -s $MY_EXT 22 -d $PEER_EXT -i $EXT_IF -j ACCEPT -## to PEER -$IPC -A input -p tcp \! -y -s $PEER_EXT 22 -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p tcp -s $MY_EXT -d $PEER_EXT 22 -i $EXT_IF -j ACCEPT - -# ipxtunnel -$IPC -A input -p udp -s $PEER_INT 2005 -d $MY_INT 2005 -i $IPSEC_IF -j ACCEPT -$IPC -A output -p udp -s $MY_INT 2005 -d $PEER_INT 2005 -i $IPSEC_IF -j ACCEPT - ----------------- end of rc.firewall ---------------------- - -To understand this we need to look on this scheme: - - ++-----------------------<----------------------------+ - || ipsec0 | - \/ | - eth0 +--------+ /---------/ yes /---------/ yes +-----------------------+ ------->| INPUT |-->/ ?local? /----->/ ?IPsec? /----->| decrypt & decapsulate | - eth1 +--------+ /---------/ /---------/ +-----------------------+ - || no || no - \/ \/ - +----------+ +---------+ +-------+ - | routing | | local | | local | - | decision | | deliver | | send | - +----------+ +---------+ +-------+ - || || - \/ \/ - +---------+ +----------+ - | forward | | routing | - +---------+ | decision | - || +----------+ - || || - ++----------------<-----------------++ - || - \/ - +--------+ eth0 - | OUTPUT | eth1 - +--------+ ipsec0 - || - \/ - /---------/ yes +-----------------------+ - / ?IPsec? /----->| encrypt & encapsulate | - /---------/ +-----------------------+ - || no || - || || - || \/ eth0, eth1 - ++-----------------------++--------------> - -This explain how a packet traverse TCP/IP stack in IPsec capable kernel. - -FIX ME, please, if there are any errors - -Test the new firewall now. - - -Now about IPX. I tried 3 programs for tunneling IPX: tipxd, SIB and ipxtunnel - -tipxd didn't send packets.. :( -SIB and ipxtunnel worked fine :) -With ipxtunnel there was a little problem. In sources there are an error. - ---------------------- in main.c ------------------------ -< bytes += p.len; ---- -> bytes += len; --------------------------------------------------------- - -After this FIX everything goes right... - -------------------- /etc/ipxtunnel.conf ---------------- -port 2005 -remote 192.168.101.97 2005 -interface eth1 ---------------- end of /etc/ipxtunnel.conf ------------- - -I use IPX tunnel between .1.1 and .2.10 so we don't need to encrypt nor -authenticate encapsulated IPX packets, it is done with IPsec. - -If you don't wont to use iproute2 to change source IP you need to use SIB -(it is able to bind local address) or establish tunnel between .0.1 and -.0.10 (external IPs, you need to do encryption in the program, but it isn't -strong). - -For now I'm using ipxtunnel. - -I think that's all for the moment. If there are any error, please e-mail me: -poltorak@df.ru . It would be cool if someone puts the scheme of TCP/IP in -kernel and firewall example on FreeS/WAN's manual pages. - -PoltoS -</pre> - -</body> -</html>
\ No newline at end of file diff --git a/doc/src/web.html b/doc/src/web.html deleted file mode 100644 index 19df6ffa6..000000000 --- a/doc/src/web.html +++ /dev/null @@ -1,905 +0,0 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" - "http://www.w3.org/TR/html4/loose.dtd"> -<html> -<head> - <meta http-equiv="Content-Type" content="text/html"> - <title>FreeS/WAN web links</title> - <meta name="keywords" - content="Linux, IPsec, VPN, security, FreeSWAN, links, web"> - <!-- - - Written by Sandy Harris for the Linux FreeS/WAN project - Freely distributable under the GNU General Public License - - More information at www.freeswan.org - Feedback to users@lists.freeswan.org - - CVS information: - RCS ID: $Id: web.html,v 1.1 2004/03/15 20:35:24 as Exp $ - Last changed: $Date: 2004/03/15 20:35:24 $ - Revision number: $Revision: 1.1 $ - - CVS revision numbers do not correspond to FreeS/WAN release numbers. - --> -</head> - -<body> -<h1><a name="weblink">Web links</a></h1> - -<h2><a name="freeswan">The Linux FreeS/WAN Project</a></h2> - -<p>The main project web site is <a -href="http://www.freeswan.org/">www.freeswan.org</a>.</p> - -<p>Links to other project-related <a href="intro.html#sites">sites</a> are -provided in our introduction section.</p> - -<h3><a name="patch">Add-ons and patches for FreeS/WAN</a></h3> - -<p>Some user-contributed patches have been integrated into the FreeS/WAN -distribution. For a variety of reasons, those listed below have not.</p> - -<p>Note that not all patches are a good idea.</p> -<ul> - <li>There are a number of "features" of IPsec which we do not implement - because they reduce security. See this <a - href="compat.html#dropped">discussion</a>. We do not recommend using - patches that implement these. One example is aggressive mode.</li> - <li>We do not recommend adding "features" of any sort unless they are - clearly necessary, or at least have clear benefits. For example, - FreeS/WAN would not become more secure if it offerred a choice of 14 - ciphers. If even one was flawed, it would certainly become less secure - for anyone using that cipher. Even with 14 wonderful ciphers, it would be - harder to maintain and administer, hence more vulnerable to various human - errors.</li> -</ul> - -<p>This is not to say that patches are necessarily bad, only that using them -requires some deliberation. For example, there might be perfectly good -reasons to add a specific cipher in your application: perhaps GOST to comply -with government standards in Eastern Europe, or AES for performance -benefits.</p> - -<h4>Current patches</h4> - -<p>Patches believed current::</p> -<ul> - <li>patches for <a href="http://www.strongsec.com/freeswan/">X.509 - certificate support</a>, also available from a <a - href="http://www.twi.ch/~sna/strongsec/freeswan/">mirror site</a></li> - <li>patches to add <a href="http://www.irrigacion.gov.ar/juanjo/ipsec">AES - and other ciphers</a>. There is preliminary data indicating AES gives a - substantial <a href="performance.html#perf.more">performance - gain</a>.</li> -</ul> - -<p>There is also one add-on that takes the form of a modified FreeS/WAN -distribution, rather than just patches to the standard distribution:</p> -<ul> - <li><a href="http://www.ipv6.iabg.de/downloadframe/index.html">IPv6 - support</a></li> -</ul> - -<p>Before using any of the above,, check the <a href="mail.html">mailing -lists</a> for news of newer versions and to see whether they have been -incorporated into more recent versions of FreeS/WAN.</p> - -<h4>Older patches</h4> -<ul> - <li><a href="http://sources.colubris.com/en/projects/FreeSWAN/">hardware - acceleration</a></li> - <li>a <a href="http://tzukanov.narod.ru/">series</a> of patches that - <ul> - <li>provide GOST, a Russian gov't. standard cipher, in MMX - assembler</li> - <li>add GOST to OpenSSL</li> - <li>add GOST to the International kernel patch</li> - <li>let FreeS/WAN use International kernel patch ciphers</li> - </ul> - </li> - <li>Neil Dunbar's patches for <a - href="ftp://hplose.hpl.hp.com/pub/nd/pluto-openssl.tar.gz">certificate - support</a>, using code from <a href="http://www.openssl.org">Open - SSL</a>.</li> - <li>Luc Lanthier's <a - href="ftp://ftp.netwinder.org/users/f/firesoul/">patches</a> for <a - href="glossary.html#PKIX">PKIX</a> support.</li> - <li><a href="ftp://ftp.heise.de/pub/ct/listings/9916-180.tgz">patches</a> - to add <a href="glossary.html#blowfish">Blowfish</a>, <a - href="glossary.html#IDEA">IDEA</a> and <a - href="glossary.html#CAST128">CAST-128</a> to FreeS/WAN</li> - <li>patches for FreeS/WAN 1.3, Pluto support for <a - href="http://alcatraz.webcriminals.com/~bastiaan/ipsec/">external - authentication</a>, for example with a smartcard or SKEYID.</li> - <li><a href="http://www.zengl.net/freeswan/download/">patches and - utilities</a> for using FreeS/WAN with PGPnet</li> - <li><a - href="http://www.freelith.com/lithworks/crypto/freeswan_patch.htm">Blowfish - encryption and Tiger hash</a></li> - <li><a - href="http://www.cendio.se/~bellman/aggressive-pluto.snap.tar.gz">patches</a> - for aggressive mode support</li> -</ul> - -<p>These patches are for older versions of FreeS/WAN and will likely not work -with the current version. Older versions of FreeS/WAN may be available on -some of the <a href="intro.html#sites">distribution sites</a>, but we -recommend using the current release.</p> - -<h4><a name="VPN.masq">VPN masquerade patches</a></h4> - -<p>Finally, there are some patches to other code that may be useful with -FreeS/WAN:</p> -<ul> - <li>a <a - href="ftp://ftp.rubyriver.com/pub/jhardin/masquerade/ip_masq_vpn.html">patch</a> - to make IPsec, PPTP and SSH VPNs work through a Linux firewall with <a - href="glossary.html#masq">IP masquerade</a>.</li> - <li><a href="http://www.linuxdoc.org/HOWTO/VPN-Masquerade-HOWTO.html">Linux - VPN Masquerade HOWTO</a></li> -</ul> - -<p>Note that this is not required if the same machine does IPsec and -masquerading, only if you want a to locate your IPsec gateway on a -masqueraded network. See our <a href="firewall.html#NAT">firewalls</a> -document for discussion of why this is problematic.</p> - -<p>At last report, this patch could not co-exist with FreeS/WAN on the same -machine.</p> - -<h3><a name="dist">Distributions including FreeS/WAN</a></h3> - -<p>The introductory section of our document set lists several <a -href="intro.html#distwith">Linux distributions</a> which include -FreeS/WAN.</p> - -<h3><a name="used">Things FreeS/WAN uses or could use</a></h3> -<ul> - <li><a href="http://openpgp.net/random">/dev/random</a> support page, - discussion of and code for the Linux <a - href="glossary.html#random">random number driver</a>. Out-of-date when we - last checked (January 2000), but still useful.</li> - <li>other programs related to random numbers: - <ul> - <li><a href="http://www.mindrot.org/audio-entropyd.html">audio entropy - daemon</a> to gather noise from a sound card and feed it into - /dev/random</li> - <li>an <a href="http://www.lothar.com/tech/crypto/">entropy-gathering - daemon</a></li> - <li>a driver for the random number generator in recent <a - href="http://sourceforge.net/projects/gkernel/">Intel chipsets</a>. - This driver is included as standard in 2.4 kernels.</li> - </ul> - </li> - <li>a Linux <a href="http://www.marko.net/l2tp/">L2TP Daemon</a> which - might be useful for communicating with Windows 2000 which builds L2TP - tunnels over its IPsec connections</li> - <li>to use opportunistic encryption, you need a recent version of <a - href="glossary.html#BIND">BIND</a>. You can get one from the <a - href="http://www.isc.org">Internet Software Consortium</a> who maintain - BIND.</li> -</ul> - -<h3><a name="alternatives">Other approaches to VPNs for Linux</a></h3> -<ul> - <li>other Linux <a href="#linuxipsec">IPsec implementations</a></li> - <li><a href="http://www.tik.ee.ethz.ch/~skip/">ENskip</a>, a free - implementation of Sun's <a href="glossary.html#SKIP">SKIP</a> - protocol</li> - <li><a href="http://sunsite.auc.dk/vpnd/">vpnd</a>, a non-IPsec VPN daemon - for Linux which creates tunnels using <a - href="glossary.html#Blowfish">Blowfish</a> encryption</li> - <li><a href="http://www.winton.org.uk/zebedee/">Zebedee</a>, a simple GPLd - tunnel-building program with Linux and Win32 versions. The name is from - <strong>Z</strong>lib compression, <strong>B</strong>lowfish encryption - and <strong>D</strong>iffie-Hellman key exchange.</li> - <li>There are at least two PPTP implementations for Linux - <ul> - <li>Moreton Bay's <a - href="http://www.moretonbay.com/vpn/pptp.html">PoPToP</a></li> - <li><a - href="http://cag.lcs.mit.edu/~cananian/Projects/PPTP/">PPTP-Linux</a></li> - </ul> - </li> - <li><a href="http://sites.inka.de/sites/bigred/devel/cipe.html">CIPE</a> - (crypto IP encapsulation) project, using their own lightweight protocol - to encrypt between routers</li> - <li><a href="http://tinc.nl.linux.org/">tinc</a>, a VPN Daemon</li> -</ul> - -<p>There is a list of <a -href="http://www.securityportal.com/lskb/10000000/kben10000005.html">Linux -VPN</a> software in the <a -href="http://www.securityportal.com/lskb/kben00000001.html">Linux Security -Knowledge Base</a>.</p> - -<h2><a name="ipsec.link">The IPsec Protocols</a></h2> - -<h3><a name="general">General IPsec or VPN information</a></h3> -<ul> - <li>The <a href="http://www.vpnc.org">VPN Consortium</a> is a group for - vendors of IPsec products. Among other things, they have a good - collection of <a href="http://www.vpnc.org/white-papers.html">IPsec white - papers</a>.</li> - <li>A VPN mailing list with a <a - href="http://kubarb.phsx.ukans.edu/~tbird/vpn.html">home page</a>, a FAQ, - some product comparisons, and many links.</li> - <li><a href="http://www.opus1.com/vpn/index.html">VPN pointer page</a></li> - <li>a <a href="http://www.epm.ornl.gov/~dunigan/vpn.html">collection</a> of - VPN links, and some explanation</li> -</ul> - -<h3><a name="overview">IPsec overview documents or slide sets</a></h3> -<ul> - <li>the FreeS/WAN <a href="ipsec.html">document section</a> on these - protocols</li> -</ul> - -<h3><a name="otherlang">IPsec information in languages other than -English</a></h3> -<ul> - <li><a - href="http://www.imib.med.tu-dresden.de/imib/Internet/Literatur/ipsec-docu.html">German</a></li> - <li><a href="http://www.kame.net/index-j.html">Japanese</a></li> - <li>Feczak Szabolcs' thesis in <a - href="http://feczo.koli.kando.hu/vpn/">Hungarian</a></li> - <li>Davide Cerri's thesis and some presentation slides <a - href="http://www.linux.it/~davide/doc/">Italian</a></li> -</ul> - -<h3><a name="RFCs1">RFCs and other reference documents</a></h3> -<ul> - <li><a href="rfc.html">Our document</a> listing the RFCs relevant to Linux - FreeS/WAN and giving various ways of obtaining both RFCs and Internet - Drafts.</li> - <li><a href="http://www.vpnc.org/vpn-standards.html">VPN Standards</a> page - maintained by <a href="glossary.html#VPNC">VPNC</a>. This covers both - RFCs and Drafts, and classifies them in a fairly helpful way.</li> - <li><a href="http://www.rfc-editor.org">RFC archive</a></li> - <li><a href="http://www.ietf.org/ids.by.wg/ipsec.html">Internet Drafts</a> - related to IPsec</li> - <li>US government <a href="http://www.itl.nist.gov/div897/pubs"> site</a> - with their <a href="glossary.html#FIPS">FIPS</a> standards</li> - <li>Archives of the ipsec@tis.com mailing list where discussion of drafts - takes place. - <ul> - <li><a href="http://www.sandelman.ottawa.on.ca/ipsec">Eastern - Canada</a></li> - <li><a href="http://www.vpnc.org/ietf-ipsec">California</a>.</li> - </ul> - </li> -</ul> - -<h3><a name="analysis">Analysis and critiques of IPsec protocols</a></h3> -<ul> - <li>Counterpane's <a - href="http://www.counterpane.com/ipsec.pdf">evaluation</a> of the - protocols</li> - <li>Simpson's <a - href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/1999/06/msg00319.html">IKE - Considered Dangerous</a> paper. Note that this is a link to an archive of - our mailing list. There are several replies in addition to the paper - itself.</li> - <li>Fate Labs <a href="http://www.fatelabs.com/loki-vpn.pdf">Virual Private - Problems: the Broken Dream</a></li> - <li>Catherine Meadows' paper <cite>Analysis of the Internet Key Exchange - Protocol Using the NRL Protocol Analyzer</cite>, in <a - href="http://chacs.nrl.navy.mil/publications/CHACS/1999/1999meadows-IEEE99.pdf">PDF</a> - or <a - href="http://chacs.nrl.navy.mil/publications/CHACS/1999/1999meadows-IEEE99.ps">Postscript</a>.</li> - <li>Perlman and Kaufmnan - <ul> - <li><a - href="http://snoopy.seas.smu.edu/ee8392_summer01/week7/perlman2.pdf">Key - Exchange in IPsec</a></li> - <li>a newer <a - href="http://sec.femto.org/wetice-2001/papers/radia-paper.pdf">PDF - paper</a>, <cite>Analysis of the IPsec Key Exchange - Standard</cite>.</li> - </ul> - </li> - <li>Bellovin's <a - href="http://www.research.att.com/~smb/papers/index.html">papers</a> page - including his: - <ul> - <li><cite>Security Problems in the TCP/IP Protocol Suite</cite> - (1989)</li> - <li><cite>Problem Areas for the IP Security Protocols</cite> (1996)</li> - <li><cite>Probable Plaintext Cryptanalysis of the IP Security - Protocols</cite> (1997)</li> - </ul> - </li> - <li>An <a href="http://www.lounge.org/ike_doi_errata.html">errata list</a> - for the IPsec RFCs.</li> -</ul> - -<h3><a name="IP.background">Background information on IP</a></h3> -<ul> - <li>An <a href="http://ipprimer.windsorcs.com/">IP tutorial</a> that seems - to be written mainly for Netware or Microsoft LAN admins entering a new - world</li> - <li><a href="http://www.iana.org">IANA</a>, Internet Assigned Numbers - Authority</li> - <li><a href="http://public.pacbell.net/dedicated/cidr.html">CIDR</a>, - Classless Inter-Domain Routing</li> - <li>Also see our <a href="biblio.html">bibliography</a></li> -</ul> - -<h2><a name="implement">IPsec Implementations</a></h2> - -<h3><a name="linuxprod">Linux products</a></h3> - -<p>Vendors using FreeS/WAN in turnkey firewall or VPN products are listed in -our <a href="intro.html#turnkey">introduction</a>.</p> - -<p>Other vendors have Linux IPsec products which, as far as we know, do not -use FreeS/WAN</p> -<ul> - <li><a href="http://www.redcreek.com/products/shareware.html">Redcreek</a> - provide an open source Linux driver for their PCI hardware VPN card. This - card has a 100 Mbit Ethernet port, an Intel 960 CPU plus more specialised - crypto chips, and claimed encryption performance of 45 Mbit/sec. The PC - sees it as an Ethernet board.</li> - <li><a href="http://linuxtoday.com/stories/8428.html?nn">Paktronix</a> - offer a Linux-based VPN with hardware encryption</li> - <li><a href="http://www.watchguard.com/">Watchguard</a> use Linux in their - Firebox product.</li> - <li><a href="http://www.entrust.com">Entrust</a> offer a developers' - toolkit for using their <a href="glossary.html#PKI">PKI</a> for IPsec - authentication</li> - <li>According to a report on our mailing list, <a - href="http://www.axent.com">Axent</a> have a Linux version of their - product.</li> -</ul> - -<h3><a name="router">IPsec in router products</a></h3> - -<p>All the major router vendors support IPsec, at least in some models.</p> -<ul> - <li><a href="http://www.cisco.com/warp/public/707/16.html">Cisco</a> IPsec - information</li> - <li>Ascend, now part of <a href="http://www.lucent.com/">Lucent</a>, have - some IPsec-based products</li> - <li><a href="http://www.nortelnetworks.com/">Bay Networks</a>, now part of - Nortel, use IPsec in their Contivity switch product line</li> - <li><a href="http://www.3com.com/products/enterprise.html">3Com</a> have a - number of VPN products, some using IPsec</li> -</ul> - -<h3><a name="fw.web">IPsec in firewall products</a></h3> - -<p>Many firewall vendors offer IPsec, either as a standard part of their -product, or an optional extra. A few we know about are:</p> -<ul> - <li><a href="http://www.borderware.com/">Borderware</a></li> - <li><a href="http://www.ashleylaurent.com/vpn/ipsec_vpn.htm">Ashley - Laurent</a></li> - <li><a href="http://www.watchguard.com">Watchguard</a></li> - <li><a href="http://www.fx.dk/firewall/ipsec.html">Injoy</a> for OS/2</li> -</ul> - -<p>Vendors using FreeS/WAN in turnkey firewall products are listed in our <a -href="intro.html#turnkey">introduction</a>.</p> - -<h3><a name="ipsecos">Operating systems with IPsec support</a></h3> - -<p>All the major open source operating systems support IPsec. See below for -details on <a href="#BSD">BSD-derived</a> Unix variants.</p> - -<p>Among commercial OS vendors, IPsec players include:</p> -<ul> - <li><a - href="http://msdn.microsoft.com/isapi/msdnlib.idc?theURL=/library/backgrnd/html/msdn_ip_security.htm">Microsoft</a> - have put IPsec in their Windows 2000 and XP products</li> - <li><a - href="http://www.s390.ibm.com/stories/1999/os390v2r8_pr.html">IBM</a> - announce a release of OS390 with IPsec support via a crypto - co-processor</li> - <li><a - href="http://www.sun.com/solaris/ds/ds-security/ds-security.pdf">Sun</a> - include IPsec in Solaris 8</li> - <li><a - href="http://www.hp.com/security/products/extranet-security.html">Hewlett - Packard</a> offer IPsec for their Unix machines</li> - <li>Certicom have IPsec available for the <a - href="http://www.certicom.com/products/movian/movianvpn_tech.html">Palm</a>.</li> - <li>There were reports before the release that Apple's Mac OS X would have - IPsec support built in, but it did not seem to be there when we last - checked. If you find, it please let us know via the <a - href="mail.html">mailing list</a>.</li> -</ul> - -<h3>IPsec on network cards</h3> - -<p>Network cards with built-in IPsec acceleration are available from at least -Intel, 3Com and Redcreek.</p> - -<h3><a name="opensource">Open source IPsec implementations</a></h3> - -<h4><a name="linuxipsec">Other Linux IPsec implementations</a></h4> - -<p>We like to think of FreeS/WAN as <em>the</em> Linux IPsec implementation, -but it is not the only one. Others we know of are:</p> -<ul> - <li><a href="http://www.enst.fr/~beyssac/pipsec/">pipsecd</a>, a - lightweight implementation of IPsec for Linux. Does not require kernel - recompilation.</li> - <li>Petr Novak's <a href="ftp://ftp.eunet.cz/icz/ipnsec/">ipnsec</a>, based - on the OpenBSD IPsec code and using <a - href="glossary.html#photuris">Photuris</a> for key management</li> - <li>A now defunct project at <a - href="http://www.cs.arizona.edu/security/hpcc-blue/linux.html">U of - Arizona</a> (export controlled)</li> - <li><a href="http://snad.ncsl.nist.gov/cerberus">NIST Cerebus</a> (export - controlled)</li> -</ul> - -<h4><a name="BSD">IPsec for BSD Unix</a></h4> -<ul> - <li><a href="http://www.kame.net/project-overview.html">KAME</a>, several - large Japanese companies co-operating on IPv6 and IPsec</li> - <li><a href="http://web.mit.edu/network/isakmp">US Naval Research Lab</a> - implementation of IPv6 and of IPsec for IPv4 (export controlled)</li> - <li><a href="http://www.openbsd.org">OpenBSD</a> includes IPsec as a - standard part of the distribution</li> - <li><a href="http://www.r4k.net/ipsec">IPsec for FreeBSD</a></li> - <li>a <a href="http://www.netbsd.org/Documentation/network/ipsec/">FAQ</a> - on NetBSD's IPsec implementation</li> -</ul> - -<h4><a name="misc">IPsec for other systems</a></h4> -<ul> - <li><a href="http://www.tcm.hut.fi/Tutkimus/IPSEC/">Helsinki U of - Technolgy</a> have implemented IPsec for Solaris, Java and Macintosh</li> -</ul> - -<h3><a name="interop.web">Interoperability</a></h3> - -<p>The IPsec protocols are designed so that different implementations should -be able to work together. As they say "the devil is in the details". IPsec -has a lot of details, but considerable success has been achieved.</p> - -<h4><a name="result">Interoperability results</a></h4> - -<p>Linux FreeS/WAN has been tested for interoperability with many other IPsec -implementations. Results to date are in our <a -href="interop.html">interoperability</a> section.</p> - -<p>Various other sites have information on interoperability between various -IPsec implementations:</p> -<ul> - <li><a href="http://www.opus1.com/vpn/atl99display.html">interop - results</a> from a bakeoff in Atlanta, September 1999.</li> - <li>a French company, HSC's, <a - href="http://www.hsc.fr/ressources/presentations/ipsec99/index.html.en">interoperability</a> - test data covers FreeS/WAN, Open BSD, KAME, Linux pipsecd, Checkpoint, - Red Creek Ravlin, and Cisco IOS</li> - <li><a href="http://www.icsa.net/">ICSA</a> offer certification programs - for various security-related products. See their list of <a - href="http://www.icsa.net/html/communities/ipsec/certification/certified_products/index.shtml"> - certified IPsec</a> products. Linux FreeS/WAN is not currently on that - list, but several products with which we interoperate are.</li> - <li>VPNC have a page on why they are not yet doing <a - href="http://www.vpnc.org/interop.html">interoperability</a> testing and - a page on the <a href="http://www.vpnc.org/conformance.html">spec - conformance</a> testing that they are doing</li> - <li>a <a href="http://www.commweb.com/article/COM20000912S0009">review</a> - comparing a dozen commercial IPsec implemetations. Unfortunately, the - reviewers did not look at Open Source implementations such as FreeS/WAN - or OpenBSD.</li> - <li><a - href="http://www.tanu.org/~sakane/doc/public/report-ike-interop0007.html">results</a> - from interoperability tests at a conference. FreeS/WAN was not tested - there.</li> - <li>test results from the <a - href="http://www.hsc.fr/ressources/veille/ipsec/ipsec2000/">IPSEC - 2000</a> conference</li> -</ul> - -<h4><a name="test1">Interoperability test sites</a></h4> -<ul> - <li><a href="http://www.tahi.org/">TAHI</a>, a Japanese IPv6 testing - project with free IPsec validation software</li> - <li><a href="http://ipsec-wit.antd.nist.gov">National Institute of - Standards and Technology</a></li> - <li><a href="http://isakmp-test.ssh.fi/">SSH Communications - Security</a></li> -</ul> - -<h2><a name="linux.link">Linux links</a></h2> - -<h3><a name="linux.basic">Basic and tutorial Linux information</a></h3> -<ul> - <li>Linux <a - href="http://linuxcentral.com/linux/LDP/LDP/gs/gs.html">Getting - Started</a> HOWTO document</li> - <li>A getting started guide from the <a - href="http://darkwing.uoregon.edu/~cchome/linuxgettingstarted.html">U of - Oregon</a></li> - <li>A large <a href="http://www.herring.org/techie.html">link - collection</a> which includes a lot of introductory and tutorial material - on Unix, Linux, the net, . . .</li> -</ul> - -<h3><a name="general">General Linux sites</a></h3> -<ul> - <li><a href="http://www.freshmeat.net">Freshmeat</a> Linux news</li> - <li><a href="http://slashdot.org">Slashdot</a> "News for Nerds"</li> - <li><a href="http://www.linux.org">Linux Online</a></li> - <li><a href="http://www.linuxhq.com">Linux HQ</a></li> - <li><a href="http://www.tux.org">tux.org</a></li> -</ul> - -<h3><a name="docs.ldp">Documentation</a></h3> - -<p>Nearly any Linux documentation you are likely to want can be found at the -<a href="http://metalab.unc.edu/LDP">Linux Documentation Project</a> or -LDP.</p> -<ul> - <li><a href="http://metalab.unc.edu/LDP/HOWTO/META-FAQ.html">Meta-FAQ</a> - guide to Linux information sources</li> - <li>The LDP's HowTo documents are a standard Linux reference. See this <a - href="http://www.linuxdoc.org/docs.html#howto">list</a>. Documents there - most relevant to a FreeS/WAN gateway are: - <ul> - <li><a href="http://metalab.unc.edu/LDP/HOWTO/Kernel-HOWTO.html">Kernel - HOWTO</a></li> - <li><a - href="http://metalab.unc.edu/LDP/HOWTO/Networking-Overview-HOWTO.html">Networking - Overview HOWTO</a></li> - <li><a - href="http://metalab.unc.edu/LDP/HOWTO/Security-HOWTO.html">Security - HOWTO</a></li> - </ul> - </li> - <li>The LDP do a series of Guides, book-sized publications with more detail - (and often more "why do it this way?") than the HowTos. See this <a - href="http://www.linuxdoc.org/guides.html">list</a>. Documents there most - relevant to a FreeS/WAN gateway are: - <ul> - <li><a href="http://www.tml.hut.fi/~viu/linux/sag/">System - Administrator's Guide</a></li> - <li><a href="http://www.linuxdoc.org/LDP/nag2/index.html">Network - Adminstrator's Guide</a></li> - <li><a href="http://www.seifried.org/lasg/">Linux Administrator's - Security Guide</a></li> - </ul> - </li> -</ul> - -<p>You may not need to go to the LDP to get this material. Most Linux -distributions include the HowTos on their CDs and several include the Guides -as well. Also, most of the Guides and some collections of HowTos are -available in book form from various publishers.</p> - -<p>Much of the LDP material is also available in languages other than -English. See this <a href="http://www.linuxdoc.org/links/nenglish.html">LDP -page</a>.</p> - -<h3><a name="advroute.web">Advanced routing</a></h3> - -<p>The Linux IP stack has some new features in 2.4 kernels. Some HowTos have -been written:</p> -<ul> - <li>several HowTos for the <a - href="http://netfilter.samba.org/unreliable-guides/">netfilter</a> - firewall code in newer kernels</li> - <li><a - href="http://www.ds9a.nl/2.4Networking/HOWTO//cvs/2.4routing/output/2.4networking.html">2.4 - networking</a> HowTo</li> - <li><a - href="http://www.ds9a.nl/2.4Networking/HOWTO//cvs/2.4routing/output/2.4routing.html">2.4 - routing</a> HowTo</li> -</ul> - -<h3><a name="linsec">Security for Linux</a></h3> - -<p>See also the <a href="#docs.ldp">LDP material</a> above.</p> -<ul> - <li><a - href="http://www.ecst.csuchico.edu/~dranch/LINUX/index-linux.html#trinityos">Trinity - OS guide to setting up Linux</a></li> - <li><a href="http://www.deter.com/unix">Unix security</a> page</li> - <li><a href="http://linux01.gwdg.de/~alatham/">PPDD</a> encrypting - filesystem</li> - <li><a href="http://EncryptionHOWTO.sourceforge.net/">Linux Encryption - HowTo</a> (outdated when last checked, had an Oct 2000 revision date in - March 2002)</li> -</ul> - -<h3><a name="firewall.linux">Linux firewalls</a></h3> - -<p>Our <a href="firewall.html">FreeS/WAN and firewalls</a> document includes -links to several sets of <a href="firewall.html#examplefw">scripts</a> known -to work with FreeS/WAN.</p> - -<p>Other information sources:</p> -<ul> - <li><a href="http://ipmasq.cjb.net/">IP Masquerade resource page</a></li> - <li><a href="http://netfilter.samba.org/unreliable-guides/">netfilter</a> - firewall code in 2.4 kernels</li> - <li>Our list of general <a href="#firewall.web">firewall references</a> on - the web</li> - <li><a href="http://users.dhp.com/~whisper/mason/">Mason</a>, a tool for - automatically configuring Linux firewalls</li> - <li>the web cache software <a href="http://www.squid-cache.org/">squid</a> - and <a href="http://www.squidguard.org/">squidguard</a> which turns Squid - into a filtering web proxy</li> -</ul> - -<h3><a name="linux.misc">Miscellaneous Linux information</a></h3> -<ul> - <li><a href="http://lwn.net/current/dists.php3">Linux distribution - vendors</a></li> - <li><a href="http://www.linux.org/groups/">Linux User Groups</a></li> -</ul> - -<h2><a name="crypto.link">Crypto and security links</a></h2> - -<h3><a name="security">Crypto and security resources</a></h3> - -<h4><a name="std.links">The standard link collections</a></h4> - -<p>Two enormous collections of links, each the standard reference in its -area:</p> -<dl> - <dt>Gene Spafford's <a - href="http://www.cerias.purdue.edu/coast/hotlist/">COAST hotlist</a></dt> - <dd>Computer and network security.</dd> - <dt>Peter Gutmann's <a - href="http://www.cs.auckland.ac.nz/~pgut001/links.html">Encryption and - Security-related Resources</a></dt> - <dd>Cryptography.</dd> -</dl> - -<h4><a name="FAQ">Frequently Asked Question (FAQ) documents</a></h4> -<ul> - <li><a href="http://www.faqs.org/faqs/cryptography-faq/">Cryptography - FAQ</a></li> - <li><a href="http://www.interhack.net/pubs/fwfaq">Firewall FAQ</a></li> - <li><a href="http://www.whitefang.com/sup/secure-faq.html">Secure Unix - Programming FAQ</a></li> - <li>FAQs for specific programs are listed in the <a href="#tools">tools</a> - section below.</li> -</ul> - -<h4><a name="cryptover">Tutorials</a></h4> -<ul> - <li>Gary Kessler's <a - href="http://www.garykessler.net/library/crypto.html">Overview of - Cryptography</a></li> - <li>Terry Ritter's <a - href="http://www.ciphersbyritter.com/LEARNING.HTM">introduction</a></li> - <li>Peter Gutman's <a - href="http://www.cs.auckland.ac.nz/~pgut001/tutorial/index.html">cryptography</a> - tutorial (500 slides in PDF format)</li> - <li>Amir Herzberg of IBM's sildes for his course <a - href="http://www.hrl.il.ibm.com/mpay/course.html">Introduction to - Cryptography and Electronic Commerce</a></li> - <li>the <a href="http://www.gnupg.org/gph/en/manual/c173.html">concepts - section</a> of the <a href="glossary.html#GPG">GNU Privacy Guard</a> - documentation</li> - <li>Bruce Schneier's self-study <a - href="http://www.counterpane.com/self-study.html">cryptanalysis</a> - course</li> -</ul> - -<p>See also the <a href="#interesting">interesting papers</a> section -below.</p> - -<h4><a name="standards">Crypto and security standards</a></h4> -<ul> - <li><a href="http://csrc.nist.gov/cc">Common Criteria</a>, new - international computer and network security standards to replace the - "Rainbow" series</li> - <li>AES <a href="http://csrc.nist.gov/encryption/aes/aes_home.htm"> - Advanced Encryption Standard </a> which will replace DES</li> - <li><a href="http://grouper.ieee.org/groups/1363">IEEE P-1363 public key - standard</a></li> - <li>our collection of links for the <a href="#ipsec.link">IPsec</a> - standards</li> - <li>history of <a - href="http://www.visi.com/crypto/evalhist/index.html">formal - evaluation</a> of security policies and implementation</li> -</ul> - -<h4><a name="quotes">Crypto quotes</a></h4> - -<p>There are several collections of cryptographic quotes on the net:</p> -<ul> - <li><a href="http://www.eff.org/pub/EFF/quotes.eff">the EFF</a></li> - <li><a href="http://www.samsimpson.com/cquotes.php">Sam Simpson</a></li> - <li><a href="http://www.amk.ca/quotations/cryptography/page-1.html">AM - Kutchling</a></li> -</ul> - -<h3><a name="policy">Cryptography law and policy</a></h3> - -<h4><a name="legal">Surveys of crypto law</a></h4> -<ul> - <li>International survey of <a - href="http://cwis.kub.nl/~FRW/PEOPLE/koops/lawsurvy.htm"> crypto - law</a>.</li> - <li>International survey of <a - href="http://rechten.kub.nl/simone/ds-lawsu.htm"> digital signature - law</a></li> -</ul> - -<h4><a name="oppose">Organisations opposing crypto restrictions</a></h4> -<ul> - <li>The <a href="glossary.html#EFF">EFF</a>'s archives on <a - href="http://www.eff.org/pub/Privacy/">privacy</a> and <a - href="http://www.eff.org/pub/Privacy/ITAR_export/">export - control</a>.</li> - <li><a href="http://www.gilc.org">Global Internet Liberty Campaign</a></li> - <li><a href="http://www.cdt.org/crypto">Center for Democracy and - Technology</a></li> - <li><a href="http://www.privacyinternational.org/">Privacy - International</a>, who give out <a - href="http://www.bigbrotherawards.org/">Big Brother Awards</a> to snoopy - organisations</li> -</ul> - -<h4><a name="other.policy">Other information on crypto policy</a></h4> -<ul> - <li><a href="ftp://ftp.isi.edu/in-notes/rfc1984.txt">RFC 1984</a>, the <a - href="glossary.html#IAB">IAB</a> and <a - href="glossary.html#IESG">IESG</a> Statement on Cryptographic Technology - and the Internet.</li> - <li>John Young's collection of <a href="http://cryptome.org/">documents</a> - of interest to the cryptography, open government and privacy movements, - organized chronologically</li> - <li>AT&T researcher Matt Blaze's Encryption, Privacy and Security <a - href="http://www.crypto.com">Resource Page</a></li> - <li>A good <a href="http://cryptome.org/crypto97-ne.htm">overview</a> of - the issues from Australia.</li> -</ul> - -<p>See also our documentation section on the <a href="politics.html">history -and politics</a> of cryptography.</p> - -<h3><a name="crypto.tech">Cryptography technical information</a></h3> - -<h4><a name="cryptolinks">Collections of crypto links</a></h4> -<ul> - <li><a href="http://www.counterpane.com/hotlist.html">Counterpane</a></li> - <li><a href="http://www.cs.auckland.ac.nz/~pgut001/links.html">Peter - Gutman's links</a></li> - <li><a href="http://www.pca.dfn.de/eng/team/ske/pem-dok.html">PKI - links</a></li> - <li><a href="http://crypto.yashy.com/www/">Robert Guerra's links</a></li> -</ul> - -<h4><a name="papers">Lists of online cryptography papers</a></h4> -<ul> - <li><a href="http://www.counterpane.com/biblio">Counterpane</a></li> - <li><a - href="http://www.cryptography.com/resources/papers">cryptography.com</a></li> - <li><a href="http://www.cryptosoft.com/html/secpub.htm">Cryptosoft</a></li> -</ul> - -<h4><a name="interesting">Particularly interesting papers</a></h4> - -<p>These papers emphasize important issues around the use of cryptography, -and the design and management of secure systems.</p> -<ul> - <li><a href="http://www.counterpane.com/keylength.html">Key length - requirements for security</a></li> - <li><a href="http://www.cl.cam.ac.uk/users/rja14/wcf.html">Why - Cryptosystems Fail</a></li> - <li><a href="http://www.cdt.org/crypto/risks98/">Risks of escrowed - encryption</a></li> - <li><a href="http://www.counterpane.com/pitfalls.html">Security pitfalls in - cryptography</a></li> - <li><a href="http://www.acm.org/classics/sep95">Reflections on Trusting - Trust</a>, Ken Thompson on Trojan horse design</li> - <li><a href="http://www.apache-ssl.org/disclosure.pdf">Security against - Compelled Disclosure</a>, how to maintain privacy in the face of legal or - other coersion</li> -</ul> - -<h3><a name="compsec">Computer and network security</a></h3> - -<h4><a name="seclink">Security links</a></h4> -<ul> - <li><a href="http://www.cs.purdue.edu/coast/hotlist">COAST Hotlist</a></li> - <li>DMOZ open directory project <a - href="http://dmoz.org/Computers/Security/">computer security</a> - links</li> - <li><a href="http://www-cse.ucsd.edu/users/bsy/sec.html">Bennet Yee</a></li> - <li>Mike Fuhr's <a - href="http://www.fuhr.org/~mfuhr/computers/security.html">link - collection</a></li> - <li><a href="http://www.networkintrusion.co.uk/">links</a> with an emphasis - on intrusion detection</li> -</ul> - -<h4><a name="firewall.web">Firewall links</a></h4> -<ul> - <li><a href="http://www.cs.purdue.edu/coast/firewalls">COAST - firewalls</a></li> - <li><a href="http://www.zeuros.co.uk">Firewalls Resource page</a></li> -</ul> - -<h4><a name="vpn">VPN links</a></h4> -<ul> - <li><a href="http://www.vpnc.org">VPN Consortium</a></li> - <li>First VPN's <a href="http://www.firstvpn.com/research/rhome.html">white - paper</a> collection</li> -</ul> - -<h4><a name="tools">Security tools</a></h4> -<ul> - <li>PGP -- mail encryption - <ul> - <li><a href="http://www.pgp.com/">PGP Inc.</a> (part of NAI) for - commercial versions</li> - <li><a href="http://web.mit.edu/network/pgp.html">MIT</a> distributes - the NAI product for non-commercial use</li> - <li><a href="http://www.pgpi.org/">international</a> distribution - site</li> - <li><a href="http://gnupg.org">GNU Privacy Guard (GPG)</a></li> - <li><a href="http://www.dk.pgp.net/pgpnet/pgp-faq/">PGP FAQ</a></li> - </ul> - A message in our mailing list archive has considerable detail on <a - href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/12/msg00029.html">available - versions</a> of PGP and on IPsec support in them. - <p><strong>Note:</strong> A fairly nasty bug exists in all commercial PGP - versions from 5.5 through 6.5.3. If you have one of those, - <strong>upgrade now</strong>.</p> - </li> - <li>SSH -- secure remote login - <ul> - <li><a href="http://www.ssh.fi">SSH Communications Security</a>, for - the original software. It is free for trial, academic and - non-commercial use.</li> - <li><a href="http://www.openssh.com/">Open SSH</a>, the Open BSD team's - free replacement</li> - <li><a href="http://www.freessh.org/">freessh.org</a>, links to free - implementations for many systems</li> - <li><a href="http://www.uni-karlsruhe.de/~ig25/ssh-faq">SSH FAQ</a></li> - <li><a - href="http://www.chiark.greenend.org.uk/~sgtatham/putty/">Putty</a>, - an SSH client for Windows</li> - </ul> - </li> - <li>Tripwire saves message digests of your system files. Re-calculate the - digests and compare to saved values to detect any file changes. There are - several versions available: - <ul> - <li><a href="http://www.tripwiresecurity.com/">commercial - version</a></li> - <li><a href="http://www.tripwire.org/">Open Source</a></li> - </ul> - </li> - <li><a href="http://www.snort.org">Snort</a> and <a - href="http://www.lids.org">LIDS</a> are intrusion detection system for - Linux</li> - <li><a href="http://www.fish.com/~zen/satan/satan.html">SATAN</a> System - Administrators Tool for Analysing Networks</li> - <li><a href="http://www.insecure.org/nmap/">NMAP</a> Network Mapper</li> - <li><a href="ftp://ftp.porcupine.org/pub/security/index.html">Wietse - Venema's page</a> with various tools</li> - <li><a href="http://ita.ee.lbl.gov/index.html">Internet Traffic - Archive</a>, various tools to analyze network traffic, mostly scripts to - organise and format tcpdump(8) output for specific purposes</li> - <li><a name="ssmail">ssmail -- sendmail patched to do</a> <a - href="glossary.html#carpediem">opportunistic encryption</a> - <ul> - <li><a href="http://www.home.aone.net.au/qualcomm/">web page</a> with - links to code and to a Usenix paper describing it, in PDF</li> - </ul> - </li> - <li><a href="http://www.openca.org/">Open CA</a> project to develop a - freely distributed <a href="glossary.html#CA">Certification Authority</a> - for building a open <a href="glossary.html#PKI">Public Key - Infrastructure</a>.</li> -</ul> - -<h3><a name="people">Links to home pages</a></h3> - -<p>David Wagner at Berkeley provides a set of links to <a -href="http://www.cs.berkeley.edu/~daw/people/crypto.html">home pages</a> of -cryptographers, cypherpunks and computer security people.</p> -</body> -</html> diff --git a/doc/testing.html b/doc/testing.html deleted file mode 100644 index 77626ba5d..000000000 --- a/doc/testing.html +++ /dev/null @@ -1,332 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="performance.html">Previous</A> -<A HREF="kernel.html">Next</A> -<HR> -<H1><A name="test.freeswan">Testing FreeS/WAN</A></H1> - This document discusses testing FreeS/WAN. -<P>Not all types of testing are described here. Other parts of the - documentation describe some tests:</P> -<DL> -<DT><A href="install.html#testinstall">installation</A> document</DT> -<DD>testing for a successful install</DD> -<DT><A href="config.html#testsetup">configuration</A> document</DT> -<DD>basic tests for a working configuration</DD> -<DT><A href="web.html#interop.web">web links</A> document</DT> -<DD>General information on tests for interoperability between various - IPsec implementations. This includes links to several test sites.</DD> -<DT><A href="interop.html">interoperation</A> document.</DT> -<DD>More specific information on FreeS/WAN interoperation with other - implementations.</DD> -<DT><A href="performance.html">performance</A> document</DT> -<DD>performance measurements</DD> -</DL> -<P>The test setups and procedures described here can also be used in - other testing, but this document focuses on testing the IPsec - functionality of FreeS/WAN.</P> -<H2><A NAME="test.oe">Testing opportunistic connections</A></H2> -<P>This section teaches you how to test your opportunistically encrypted - (OE) connections. To set up OE, please see the easy instructions in our<A -HREF="quickstart.html"> quickstart guide</A>.</P> -<H3><A NAME="12_1_1">Basic OE Test</A></H3> -<P>This test is for basic OE functionality. -<!-- You may use it on an -<A HREF="quickstart.html#oppo.client">initiate-only OE</A> box or a -<A HREF="quickstart.html#opp.incoming">full OE</A> box. --> - For additional tests, keep - reading.</P> -<P>Be sure IPsec is running. You can see whether it is with:</P> -<PRE> ipsec setup status</PRE> -<P>If need be, you can restart it with:</P> -<PRE> service ipsec restart</PRE> -<P>Load a FreeS/WAN test website from the host on which you're running - FreeS/WAN. Note: the feds may be watching these sites. Type one of:</P> -<P></P> -<PRE> links oetest.freeswan.org</PRE> -<PRE> links oetest.freeswan.nl</PRE> - -<!--<PRE> links oetest.freeswan.ca</PRE>--> -<P>A positive result looks like this:</P> -<PRE> - You seem to be connecting from: 192.0.2.11 which DNS says is: - gateway.example.com - _________________________________________________________________ - - Status E-route - OE enabled 16 192.139.46.73/32 -> 192.0.2.11/32 => - tun0x2097@192.0.2.11 - OE enabled 176 192.139.46.77/32 -> 192.0.2.11/32 => - tun0x208a@192.0.2.11 -</PRE> -<P>If you see this, congratulations! Your OE box will now encrypt its - own traffic whenever it can. If you have difficulty, see our<A HREF="quickstart.html#oe.trouble"> - OE troubleshooting tips</A>.</P> -<H3><A NAME="12_1_2">OE Gateway Test</A></H3> -<P>If you've set up FreeS/WAN to protect a subnet behind your gateway, - you'll need to run another simple test, which can be done from a - machine running any OS. That's right, your Windows box can be protected - by opportunistic encryption without any FreeS/WAN install or - configuration on that box. From<STRONG> each protected subnet node</STRONG> -, load the FreeS/WAN website with:</P> -<PRE> links oetest.freeswan.org</PRE> -<PRE> links oetest.freeswan.nl</PRE> -<P>A positive result looks like this:</P> -<PRE> - You seem to be connecting from: 192.0.2.98 which DNS says is: - box98.example.com - _________________________________________________________________ - - Status E-route - OE enabled 16 192.139.46.73/32 -> 192.0.2.98/32 => - tun0x134ed@192.0.2.11 - OE enabled 176 192.139.46.77/32 -> 192.0.2.11/32 => - tun0x134d2@192.0.2.11 -</PRE> -<P>If you see this, congratulations! Your OE gateway will now encrypt - traffic for this subnet node whenever it can. If you have difficulty, - see our<A HREF="quickstart.html#oe.trouble"> OE troubleshooting tips</A> -.</P> -<H3><A NAME="12_1_3">Additional OE tests</A></H3> -<P>When testing OE, you will often find it useful to execute this - command on the FreeS/WAN host:</P> -<PRE> ipsec eroute</PRE> -<P>If you have established a connection (either for or for a subnet - node) you will see a result like:</P> -<PRE> 192.0.2.11/32 -> 192.139.46.73/32 => tun0x149f@192.139.46.38 -</PRE> -<P>Key:</P> -<TABLE> -<TR><TD>1.</TD><TD>192.0.2.11/32</TD><TD>Local start point of the - protected traffic.</TD></TR> -<TR><TD>2.</TD><TD>192.0.2.194/32</TD><TD>Remote end point of the - protected traffic.</TD></TR> -<TR><TD>3.</TD><TD>192.0.48.38</TD><TD>Remote FreeS/WAN node (gateway or - host). May be the same as (2).</TD></TR> -<TR><TD>4.</TD><TD>[not shown]</TD><TD>Local FreeS/WAN node (gateway or - host), where you've produced the output. May be the same as (1).</TD></TR> -</TABLE> -<P>For extra assurance, you may wish to use a packet sniffer such as<A HREF="http://www.tcpdump.org"> - tcpdump</A> to verify that packets are being encrypted. You should see - output that indicates<STRONG> ESP</STRONG> encrypted data, for example:</P> -<PRE> 02:17:47.353750 PPPoE [ses 0x1e12] IP 154: xy.example.com > oetest.freeswan.org: ESP(spi=0x87150d16,seq=0x55)</PRE> -<H2><A name="test.uml">Testing with User Mode Linux</A></H2> -<P><A href="http://user-mode-linux.sourceforge.net/">User Mode Linux</A> - allows you to run Linux as a user process on another Linux machine.</P> -<P>As of 1.92, the distribution has a new directory named testing. It - contains a collection of test scripts and sample configurations. Using - these, you can bring up several copies of Linux in user mode and have - them build tunnels to each other. This lets you do some testing of a - FreeS/WAN configuration on a single machine.</P> -<P>You need a moderately well-endowed machine for this to work well. - Each UML wants about 16 megs of memory by default, which is plenty for - FreeS/WAN usage. Typical regression testing only occasionally uses as - many as 4 UMLs. If one is doing nothing else with the machine (in - particular, not running X on it), then 128 megs and a 500MHz CPU are - fine.</P> - Documentation on these scripts is<A href="umltesting.html"> here</A>. - There is also documentation on automated testing<A href="makecheck.html"> - here</A>. -<H2><A name="testnet">Configuration for a testbed network</A></H2> -<P>A common test setup is to put a machine with dual Ethernet cards in - between two gateways under test. You need at least five machines; two - gateways, two clients and a testing machine in the middle.</P> -<P>The central machine both routes packets and provides a place to run - diagnostic software for checking IPsec packets. See next section for - discussion of<A href="faq.html#tcpdump.faq"> using tcpdump(8)</A> for - this.</P> -<P>This makes things more complicated than if you just connected the two - gateway machines directly to each other, but it also makes your test - setup much more like the environment you actually use IPsec in. Those - environments nearly always involve routing, and quite a few apparent - IPsec failures turn out to be problems with routing or with firewalls - dropping packets. This approach lets you deal with those problems on - your test setup.</P> -<P>What you end up with looks like:</P> -<H3><A name="testbed">Testbed network</A></H3> -<PRE> subnet a.b.c.0/24 - | - eth1 = a.b.c.1 - gate1 - eth0 = 192.168.p.1 - | - | - eth0 = 192.168.p.2 - route/monitor box - eth1 = 192.168.q.2 - | - | - eth0 = 192.168.q.1 - gate2 - eth1 = x.y.z.1 - | - subnet x.y.z.0/24</PRE> -<PRE>Where p and q are any convenient values that do not interfere with other -routes you may have. The ipsec.conf(5) file then has, among other things:</PRE> -<PRE>conn abc-xyz - left=192.168.p.1 - leftnexthop=192.168.p.2 - right=192.168.q.1 - rightnexthop=192.168.q.2</PRE> -<P>Once that works, you can remove the "route/monitor box", and connect - the two gateways to the Internet. The only parameters in ipsec.conf(5) - that need to change are the four shown above. You replace them with - values appropriate for your Internet connection, and change the eth0 IP - addresses and the default routes on both gateways.</P> -<P>Note that nothing on either subnet needs to change. This lets you - test most of your IPsec setup before connecting to the insecure - Internet.</P> -<H3><A name="tcpdump.test">Using packet sniffers in testing</A></H3> -<P>A number of tools are available for looking at packets. We will - discuss using<A href="http://www.tcpdump.org/"> tcpdump(8)</A>, a - common Linux tool included in most distributions. Alternatives - offerring more-or-less the same functionality include:</P> -<DL> -<DT><A href="http://www.ethereal.com">Ethereal</A></DT> -<DD>Several people on our mailing list report a preference for this over - tcpdump.</DD> -<DT><A href="http://netgroup-serv.polito.it/windump/">windump</A></DT> -<DD>a Windows version of tcpdump(8), possibly handy if you have Windows - boxes in your network</DD> -<DT><A href="http://reptile.rug.ac.be/~coder/sniffit/sniffit.html"> -Sniffit</A></DT> -<DD>A linux sniffer that we don't know much about. If you use it, please - comment on our mailing list.</DD> -</DL> -<P>See also this<A href="http://www.tlsecurity.net/unix/ids/sniffer/"> - index</A> of packet sniffers.</P> -<P>tcpdump(8) may misbehave if run on the gateways themselves. It is - designed to look into a normal IP stack and may become confused if you - ask it to display data from a stack which has IPsec in play.</P> -<P>At one point, the problem was quite severe. Recent versions of - tcpdump, however, understand IPsec well enough to be usable on a - gateway. You can get the latest version from<A href="http://www.tcpdump.org/"> - tcpdump.org</A>.</P> -<P>Even with a recent tcpdump, some care is required. Here is part of a - post from Henry on the topic:</P> -<PRE>> a) data from sunset to sunrise or the other way is not being -> encrypted (I am using tcpdump (ver. 3.4) -x/ping -p to check -> packages) - -What *interface* is tcpdump being applied to? Use the -i option to -control this. It matters! If tcpdump is looking at the ipsecN -interfaces, e.g. ipsec0, then it is seeing the packets before they are -encrypted or after they are decrypted, so of course they don't look -encrypted. You want to have tcpdump looking at the actual hardware -interfaces, e.g. eth0. - -Actually, the only way to be *sure* what you are sending on the wire is to -have a separate machine eavesdropping on the traffic. Nothing you can do -on the machines actually running IPsec is 100% guaranteed reliable in this -area (although tcpdump is a lot better now than it used to be).</PRE> -<P>The most certain way to examine IPsec packets is to look at them on - the wire. For security, you need to be certain, so we recommend doing - that. To do so, you need a<STRONG> separate sniffer machine located - between the two gateways</STRONG>. This machine can be routing IPsec - packets, but it must not be an IPsec gateway. Network configuration for - such testing is discussed<A href="#testnet"> above</A>.</P> -<P>Here's another mailing list message with advice on using tcpdump(8):</P> -<PRE>Subject: RE: [Users] Encrypted??? - Date: Thu, 29 Nov 2001 - From: "Joe Patterson" <jpatterson@asgardgroup.com> - -tcpdump -nl -i $EXT-IF proto 50 - --nl tells it not to buffer output or resolve names (if you don't do that it -may confuse you by not outputing anything for a while), -i $EXT-IF (replace -with your external interface) tells it what interface to listen on, and -proto 50 is ESP. Use "proto 51" if for some odd reason you're using AH, and -"udp port 500" if you want to see the isakmp key exchange/tunnel setup -packets. - -You can also run `tcpdump -nl -i ipsec0` to see what traffic is on that -virtual interface. Anything you see there *should* be either encrypted or -dropped (unless you've turned on some strange options in your ipsec.conf -file) - -Another very handy thing is ethereal (http://www.ethereal.com/) which runs -on just about anything, has a nice gui interface (or a nice text-based -interface), and does a great job of protocol breakdown. For ESP and AH -it'll basically just tell you that there's a packet of that protocol, and -what the spi is, but for isakmp it'll actually show you a lot of the tunnel -setup information (until it gets to the point in the protocol where isakmp -is encrypted....)</PRE> -<H2><A name="verify.crypt">Verifying encryption</A></H2> -<P>The question of how to verify that messages are actually encrypted - has been extensively discussed on the mailing list. See this<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/07/msg00262.html"> - thread</A>.</P> -<P>If you just want to verify that packets are encrypted, look at them - with a packet sniffer (see<A href="#tcpdump.test"> previous section</A> -) located between the gateways. The packets should, except for some of - the header information, be utterly unintelligible.<STRONG> The output - of good encryption looks<EM> exactly</EM> like random noise</STRONG>.</P> -<P>A packet sniffer can only tell you that the data you looked at was - encrypted. If you have stronger requirements -- for example if your - security policy requires verification that plaintext is not leaked - during startup or under various anomolous conditions -- then you will - need to devise much more thorough tests. If you do that, please post - any results or methodological details which your security policy allows - you to make public.</P> -<P>You can put recognizable data into ping packets with something like:</P> -<PRE> ping -p feedfacedeadbeef 11.0.1.1</PRE> -<P>"feedfacedeadbeef" is a legal hexadecimal pattern that is easy to - pick out of hex dumps.</P> -<P>For other protocols, you may need to check if you have encrypted data - or ASCII text. Encrypted data has approximately equal frequencies for - all 256 possible characters. ASCII text has most characters in the - printable range 0x20-0x7f, a few control characters less than 0x20, and - none at all in the range 0x80-0xff. 0x20, space, is a good character to - look for. In normal English text space occurs about once in seven - characters, versus about once in 256 for random or encrypted data.</P> -<P>One thing to watch for: the output of good compression, like that of - good encryption, looks just like random noise. You cannot tell just by - looking at a data stream whether it has been compressed, encrypted, or - both. You need a little care not to mistake compressed data for - encrypted data in your testing.</P> -<P>Note also that weak encryption also produces random-looking output. - You cannot tell whether the encryption is strong by looking at the - output. To be sure of that, you would need to have both the algorithms - and the implementation examined by experts.</P> -<P>For IPsec, you can get partial assurance from interoperability tests. - See our<A href="interop.html"> interop</A> document. When twenty - products all claim to implement<A href="glossary.html#3DES"> 3DES</A>, - and they all talk to each other, you can be fairly sure they have it - right. Of course, you might wonder whether all the implementers are - consipring to trick you or, more plausibly, whether some - implementations might have "back doors" so they can get also it wrong - when required.. If you're seriously worried about things like that, you - need to get the code you use audited (good luck if it is not Open - Source), or perhaps to talk to a psychiatrist about treatments for - paranoia.</P> -<H2><A name="mail.test">Mailing list pointers</A></H2> -<P>Additional information on testing can be found in these<A href="mail.html"> - mailing list</A> messages:</P> -<UL> -<LI>a user's detailed<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/11/msg00571.html"> - setup diary</A> for his testbed network</LI> -<LI>a FreeS/WAN team member's<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/11/msg00425.html"> - notes</A> from testing at an IPsec interop "bakeoff"</LI> -</UL> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="performance.html">Previous</A> -<A HREF="kernel.html">Next</A> -</BODY> -</HTML> diff --git a/doc/toc.html b/doc/toc.html deleted file mode 100644 index 047833020..000000000 --- a/doc/toc.html +++ /dev/null @@ -1,1019 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<H1 ALIGN="CENTER"><A NAME="CONTENTS">Table of Contents</A></H1> -<BR> -<BR><B><A HREF="intro.html#intro">Introduction</A></B> -<UL> -<LI><A HREF="intro.html#ipsec.intro">IPsec, Security for the Internet - Protocol</A></LI> -<UL> -<LI><A HREF="intro.html#intro.interop">Interoperating with other IPsec - implementations</A></LI> -<LI><A HREF="ipsec.html#advantages">Advantages of IPsec</A></LI> -<LI><A HREF="intro.html#applications">Applications of IPsec</A></LI> -<LI><A HREF="intro.html#types">The need to authenticate gateways</A></LI> -</UL> -<LI><A HREF="intro.html#project">The FreeS/WAN project</A></LI> -<UL> -<LI><A HREF="intro.html#goals">Project goals</A></LI> -<LI><A HREF="intro.html#staff">Project team</A></LI> -</UL> -<LI><A HREF="intro.html#products">Products containing FreeS/WAN</A></LI> -<UL> -<LI><A HREF="intro.html#distwith">Full Linux distributions</A></LI> -<LI><A HREF="intro.html#kernel_dist">Linux kernel distributions</A></LI> -<LI><A HREF="intro.html#office_dist">Office server distributions</A></LI> -<LI><A HREF="intro.html#fw_dist">Firewall distributions</A></LI> -<LI><A HREF="intro.html#turnkey">Firewall and VPN products</A></LI> -</UL> -<LI><A HREF="intro.html#docs">Information sources</A></LI> -<UL> -<LI><A HREF="intro.html#docformats">This HowTo, in multiple formats</A></LI> -<LI><A HREF="intro.html#rtfm">RTFM (please Read The Fine Manuals)</A></LI> -<LI><A HREF="intro.html#text">Other documents in the distribution</A></LI> -<LI><A HREF="intro.html#assumptions">Background material</A></LI> -<LI><A HREF="intro.html#archives">Archives of the project mailing list</A> -</LI> -<LI><A HREF="intro.html#howto">User-written HowTo information</A></LI> -<LI><A HREF="intro.html#applied">Papers on FreeS/WAN</A></LI> -<LI><A HREF="intro.html#licensing">License and copyright information</A></LI> -</UL> -<LI><A HREF="intro.html#sites">Distribution sites</A></LI> -<UL> -<LI><A HREF="intro.html#1_5_1">Primary site</A></LI> -<LI><A HREF="intro.html#mirrors">Mirrors</A></LI> -<LI><A HREF="intro.html#munitions">The "munitions" archive of Linux - crypto software</A></LI> -</UL> -<LI><A HREF="intro.html#1_6">Links to other sections</A></LI> -</UL> -<B><A HREF="upgrading.html#2">Upgrading to FreeS/WAN 2.x</A></B> -<UL> -<LI><A HREF="upgrading.html#2_1">New! Built in Opportunistic connections</A> -</LI> -<UL> -<LI><A HREF="upgrading.html#2_1_1">Upgrading Opportunistic Encryption to - 2.01 (or later)</A></LI> -</UL> -<LI><A HREF="upgrading.html#2_2">New! Policy Groups</A></LI> -<LI><A HREF="upgrading.html#2_3">New! Packetdefault Connection</A></LI> -<LI><A HREF="upgrading.html#2_4">FreeS/WAN now disables Reverse Path - Filtering</A></LI> -<LI><A HREF="upgrading.html#2_5">Revised ipsec.conf</A></LI> -<UL> -<LI><A HREF="upgrading.html#2_5_1">No promise of compatibility</A></LI> -<LI><A HREF="upgrading.html#2_5_2">Most ipsec.conf files will work fine</A> -</LI> -<LI><A HREF="upgrading.html#2_5_3">Backward compatibility patch</A></LI> -<LI><A HREF="upgrading.html#2_5_4">Details</A></LI> -<LI><A HREF="upgrading.html#2_5_5">Upgrading from 1.x RPMs to 2.x RPMs</A> -</LI> -</UL> -</UL> -<B><A HREF="quickstart.html#quickstart">Quickstart Guide to - Opportunistic Encryption</A></B> -<UL> -<LI><A HREF="quickstart.html#opp.setup">Purpose</A></LI> -<UL> -<LI><A HREF="quickstart.html#3_1_1">OE "flag day"</A></LI> -</UL> -<LI><A HREF="quickstart.html#opp.dns">Requirements</A></LI> -<LI><A HREF="quickstart.html#easy.install">RPM install</A></LI> -<UL> -<LI><A HREF="quickstart.html#3_3_1">Download RPMs</A></LI> -<LI><A HREF="quickstart.html#3_3_2">Check signatures</A></LI> -<LI><A HREF="quickstart.html#3_3_3">Install the RPMs</A></LI> -<LI><A HREF="quickstart.html#testinstall">Test</A></LI> -</UL> -<LI><A HREF="quickstart.html#opp.setups.list">Our Opportunistic Setups</A> -</LI> -<UL> -<LI><A HREF="quickstart.html#3_4_1">Full or partial opportunism?</A></LI> -</UL> -<LI><A HREF="quickstart.html#opp.client">Initiate-only setup</A></LI> -<UL> -<LI><A HREF="quickstart.html#3_5_1">Restrictions</A></LI> -<LI><A HREF="quickstart.html#forward.dns">Create and publish a forward - DNS record</A></LI> -<LI><A HREF="quickstart.html#3_5_3">Test that your key has been - published</A></LI> -<LI><A HREF="quickstart.html#3_5_4">Configure, if necessary</A></LI> -<LI><A HREF="quickstart.html#3_5_5">Test</A></LI> -</UL> -<LI><A HREF="quickstart.html#3_6">Full Opportunism</A></LI> -<UL> -<LI><A HREF="quickstart.html#3_6_1">Put a TXT record in a Forward Domain</A> -</LI> -<LI><A HREF="quickstart.html#3_6_2">Put a TXT record in Reverse DNS</A></LI> -<LI><A HREF="quickstart.html#3_6_3">Test your DNS record</A></LI> -<LI><A HREF="quickstart.html#3_6_4">No Configuration Needed</A></LI> -<LI><A HREF="quickstart.html#3_6_5">Consider Firewalling</A></LI> -<LI><A HREF="quickstart.html#3_6_6">Test</A></LI> -<LI><A HREF="quickstart.html#3_6_7">Test</A></LI> -</UL> -<LI><A HREF="quickstart.html#opp.test">Testing opportunistic connections</A> -</LI> -<LI><A HREF="quickstart.html#3_8">Now what?</A></LI> -<LI><A HREF="quickstart.html#3_9">Notes</A></LI> -<LI><A HREF="quickstart.html#3_10">Troubleshooting OE</A></LI> -<LI><A HREF="quickstart.html#3_11">Known Issues</A></LI> -</UL> -<B><A HREF="policygroups.html#4">How to Configure Linux FreeS/WAN with - Policy Groups</A></B> -<UL> -<LI><A HREF="policygroups.html#4_1">What are Policy Groups?</A></LI> -<UL> -<LI><A HREF="policygroups.html#4_1_1">Built-In Security Options</A></LI> -</UL> -<LI><A HREF="policygroups.html#4_2">Using Policy Groups</A></LI> -<UL> -<LI><A HREF="policygroups.html#4_2_1">Example 1: Using a Base Policy - Group</A></LI> -<LI><A HREF="policygroups.html#4_2_2">Example 2: Defining IPsec Security - Policy with Groups</A></LI> -<LI><A HREF="policygroups.html#4_2_3">Example 3: Creating a Simple IPsec - VPN with the private Group</A></LI> -<LI><A HREF="policygroups.html#4_2_4">Example 4: New Policy Groups to - Protect a Subnet</A></LI> -<LI><A HREF="policygroups.html#4_2_5">Example 5: Adding a Subnet to the - VPN</A></LI> -</UL> -<LI><A HREF="policygroups.html#4_3">Appendix</A></LI> -<UL> -<LI><A HREF="policygroups.html#4_3_1">Our Hidden Connections</A></LI> -<LI><A HREF="policygroups.html#4_3_2">Custom Policy Groups</A></LI> -<LI><A HREF="policygroups.html#4_3_3">Disabling Opportunistic Encryption</A> -</LI> -</UL> -</UL> -<B><A HREF="faq.html#5">FreeS/WAN FAQ</A></B> -<UL> -<LI><A HREF="faq.html#questions">Index of FAQ questions</A></LI> -<LI><A HREF="faq.html#whatzit">What is FreeS/WAN?</A></LI> -<LI><A HREF="faq.html#problems">How do I report a problem or seek help?</A> -</LI> -<LI><A HREF="faq.html#generic">Can I get ...</A></LI> -<UL> -<LI><A HREF="faq.html#lemme_out">Can I get an off-the-shelf system that - includes FreeS/WAN?</A></LI> -<LI><A HREF="faq.html#consultant">Can I hire consultants or staff who - know FreeS/WAN?</A></LI> -<LI><A HREF="faq.html#commercial">Can I get commercial support?</A></LI> -</UL> -<LI><A HREF="faq.html#release">Release questions</A></LI> -<UL> -<LI><A HREF="faq.html#rel.current">What is the current release?</A></LI> -<LI><A HREF="faq.html#relwhen">When is the next release?</A></LI> -<LI><A HREF="faq.html#rel.bugs">Are there known bugs in the current - release?</A></LI> -</UL> -<LI><A HREF="faq.html#mod_cons">Modifications and contributions</A></LI> -<UL> -<LI><A HREF="faq.html#modify.faq">Can I modify FreeS/WAN to ...?</A></LI> -<LI><A HREF="faq.html#contrib.faq">Can I contribute to the project?</A></LI> -<LI><A HREF="faq.html#ddoc.faq">Is there detailed design documentation?</A> -</LI> -</UL> -<LI><A HREF="faq.html#interact">Will FreeS/WAN work in my environment?</A> -</LI> -<UL> -<LI><A HREF="faq.html#interop.faq">Can FreeS/WAN talk to ...?</A></LI> -<LI><A HREF="faq.html#old_to_new">Can different FreeS/WAN versions talk - to each other?</A></LI> -<LI><A HREF="faq.html#faq.bandwidth">Is there a limit on throughput?</A></LI> -<LI><A HREF="faq.html#faq.number">Is there a limit on number of tunnels?</A> -</LI> -<LI><A HREF="faq.html#faq.speed">Is a ... fast enough to handle - FreeS/WAN with my loads?</A></LI> -</UL> -<LI><A HREF="faq.html#work_on">Will FreeS/WAN work on ... ?</A></LI> -<UL> -<LI><A HREF="faq.html#versions">Will FreeS/WAN run on my version of - Linux?</A></LI> -<LI><A HREF="faq.html#nonIntel.faq">Will FreeS/WAN run on non-Intel - CPUs?</A></LI> -<LI><A HREF="faq.html#multi.faq">Will FreeS/WAN run on multiprocessors?</A> -</LI> -<LI><A HREF="faq.html#k.old">Will FreeS/WAN work on an older kernel?</A></LI> -<LI><A HREF="faq.html#k.versions">Will FreeS/WAN run on the latest - kernel version?</A></LI> -<LI><A HREF="faq.html#interface.faq">Will FreeS/WAN work on unusual - network hardware?</A></LI> -<LI><A HREF="faq.html#vlan">Will FreeS/WAN work on a VLAN (802.1q) - network?</A></LI> -</UL> -<LI><A HREF="faq.html#features.faq">Does FreeS/WAN support ...</A></LI> -<UL> -<LI><A HREF="faq.html#VPN.faq">Does FreeS/WAN support site-to-site VPN ( -Virtual Private Network) applications?</A></LI> -<LI><A HREF="faq.html#warrior.faq">Does FreeS/WAN support remote users - connecting to a LAN?</A></LI> -<LI><A HREF="faq.html#road.shared.possible">Does FreeS/WAN support - remote users using shared secret authentication?</A></LI> -<LI><A HREF="faq.html#wireless.faq">Does FreeS/WAN support wireless - networks?</A></LI> -<LI><A HREF="faq.html#PKIcert">Does FreeS/WAN support X.509 or other PKI - certificates?</A></LI> -<LI><A HREF="faq.html#Radius">Does FreeS/WAN support user authentication - (Radius, SecureID, Smart Card...)?</A></LI> -<LI><A HREF="faq.html#NATtraversal">Does FreeS/WAN support NAT - traversal?</A></LI> -<LI><A HREF="faq.html#virtID">Does FreeS/WAN support assigning a - "virtual identity" to a remote system?</A></LI> -<LI><A HREF="faq.html#noDES.faq">Does FreeS/WAN support single DES - encryption?</A></LI> -<LI><A HREF="faq.html#AES.faq">Does FreeS/WAN support AES encryption?</A> -</LI> -<LI><A HREF="faq.html#other.cipher">Does FreeS/WAN support other - encryption algorithms?</A></LI> -</UL> -<LI><A HREF="faq.html#canI">Can I ...</A></LI> -<UL> -<LI><A HREF="faq.html#policy.preconfig">Can I use policy groups along - with explicitly configured connections?</A></LI> -<LI><A HREF="faq.html#policy.off">Can I turn off policy groups?</A></LI> -<LI><A HREF="faq.html#reload">Can I reload connection info without - restarting?</A></LI> -<LI><A HREF="faq.html#masq.faq">Can I use several masqueraded subnets?</A> -</LI> -<LI><A HREF="faq.html#dup_route">Can I use subnets masqueraded to the - same addresses?</A></LI> -<LI><A HREF="faq.html#road.masq">Can I assign a road warrior an address - on my net (a virtual identity)?</A></LI> -<LI><A HREF="faq.html#road.many">Can I support many road warriors with - one gateway?</A></LI> -<LI><A HREF="faq.html#road.PSK">Can I have many road warriors using - shared secret authentication?</A></LI> -<LI><A HREF="faq.html#QoS">Can I use Quality of Service routing with - FreeS/WAN?</A></LI> -<LI><A HREF="faq.html#deadtunnel">Can I recognise dead tunnels and shut - them down?</A></LI> -<LI><A HREF="faq.html#demanddial">Can I build IPsec tunnels over a - demand-dialed link?</A></LI> -<LI><A HREF="faq.html#GRE">Can I build GRE, L2TP or PPTP tunnels over - IPsec?</A></LI> -<LI><A HREF="faq.html#NetBIOS">... use Network Neighborhood (Samba, - NetBIOS) over IPsec?</A></LI> -</UL> -<LI><A HREF="faq.html#setup.faq">Life's little mysteries</A></LI> -<UL> -<LI><A HREF="faq.html#cantping">I cannot ping ....</A></LI> -<LI><A HREF="faq.html#forever">It takes forever to ...</A></LI> -<LI><A HREF="faq.html#route">I send packets to the tunnel with route(8) - but they vanish</A></LI> -<LI><A HREF="faq.html#down_route">When a tunnel goes down, packets - vanish</A></LI> -<LI><A HREF="faq.html#firewall_ate">The firewall ate my packets!</A></LI> -<LI><A HREF="faq.html#dropconn">Dropped connections</A></LI> -<LI><A HREF="faq.html#defaultroutegone">Disappearing %defaultroute</A></LI> -<LI><A HREF="faq.html#tcpdump.faq">TCPdump on the gateway shows strange - things</A></LI> -<LI><A HREF="faq.html#no_trace">Traceroute does not show anything - between the gateways</A></LI> -</UL> -<LI><A HREF="faq.html#man4debug">Testing in stages</A></LI> -<UL> -<LI><A HREF="faq.html#nomanual">Manually keyed connections don't work</A> -</LI> -<LI><A HREF="faq.html#spi_error">One manual connection works, but second - one fails</A></LI> -<LI><A HREF="faq.html#man_no_auto">Manual connections work, but - automatic keying doesn't</A></LI> -<LI><A HREF="faq.html#nocomp">IPsec works, but connections using - compression fail</A></LI> -<LI><A HREF="faq.html#pmtu.broken">Small packets work, but large - transfers fail</A></LI> -<LI><A HREF="faq.html#subsub">Subnet-to-subnet works, but tests from the - gateways don't</A></LI> -</UL> -<LI><A HREF="faq.html#compile.faq">Compilation problems</A></LI> -<UL> -<LI><A HREF="faq.html#gmp.h_missing">gmp.h: No such file or directory</A> -</LI> -<LI><A HREF="faq.html#noVM">... virtual memory exhausted</A></LI> -</UL> -<LI><A HREF="faq.html#error">Interpreting error messages</A></LI> -<UL> -<LI><A HREF="faq.html#route-client">route-client (or host) exited with - status 7</A></LI> -<LI><A HREF="faq.html#unreachable">SIOCADDRT:Network is unreachable</A></LI> -<LI><A HREF="faq.html#modprobe">ipsec_setup: modprobe: Can't locate - module ipsec</A></LI> -<LI><A HREF="faq.html#noKLIPS">ipsec_setup: Fatal error, kernel appears - to lack KLIPS</A></LI> -<LI><A HREF="faq.html#noDNS">ipsec_setup: ... failure to fetch key for - ... from DNS</A></LI> -<LI><A HREF="faq.html#dup_address">ipsec_setup: ... interfaces ... and - ... share address ...</A></LI> -<LI><A HREF="faq.html#kflags">ipsec_setup: Cannot adjust kernel flags</A> -</LI> -<LI><A HREF="faq.html#message_num">Message numbers (MI3, QR1, et cetera) - in Pluto messages</A></LI> -<LI><A HREF="faq.html#conn_name">Connection names in Pluto error - messages</A></LI> -<LI><A HREF="faq.html#cantorient">Pluto: ... can't orient connection</A></LI> -<LI><A HREF="faq.html#no.interface">... we have no ipsecN interface for - either end of this connection</A></LI> -<LI><A HREF="faq.html#noconn">Pluto: ... no connection is known</A></LI> -<LI><A HREF="faq.html#nosuit">Pluto: ... no suitable connection ...</A></LI> -<LI><A HREF="faq.html#noconn.auth">Pluto: ... no connection has been - authorized</A></LI> -<LI><A HREF="faq.html#noDESsupport">Pluto: ... OAKLEY_DES_CBC is not - supported.</A></LI> -<LI><A HREF="faq.html#notransform">Pluto: ... no acceptable transform</A> -</LI> -<LI><A HREF="faq.html#rsasigkey">rsasigkey dumps core</A></LI> -<LI><A HREF="faq.html#sig4">!Pluto failure!: ... exited with ... signal - 4</A></LI> -<LI><A HREF="faq.html#econnrefused">ECONNREFUSED error message</A></LI> -<LI><A HREF="faq.html#no_eroute">klips_debug: ... no eroute!</A></LI> -<LI><A HREF="faq.html#SAused">... trouble writing to /dev/ipsec ... SA - already in use</A></LI> -<LI><A HREF="faq.html#ignore">... ignoring ... payload</A></LI> -<LI><A HREF="faq.html#unknown_rightcert">unknown parameter name - "rightcert"</A></LI> -</UL> -<LI><A HREF="faq.html#spam">Why don't you restrict the mailing lists to - reduce spam?</A></LI> -</UL> -<B><A HREF="manpages.html#manpages">FreeS/WAN manual pages</A></B> -<UL> -<LI><A HREF="manpages.html#man.file">Files</A></LI> -<LI><A HREF="manpages.html#man.command">Commands</A></LI> -<LI><A HREF="manpages.html#man.lib">Library routines</A></LI> -</UL> -<B><A HREF="firewall.html#firewall">FreeS/WAN and firewalls</A></B> -<UL> -<LI><A HREF="firewall.html#filters">Filtering rules for IPsec packets</A> -</LI> -<LI><A HREF="firewall.html#examplefw">Firewall configuration at boot</A></LI> -<UL> -<LI><A HREF="firewall.html#simple.rules">A simple set of rules</A></LI> -<LI><A HREF="firewall.html#complex.rules">Other rules</A></LI> -<LI><A HREF="firewall.html#rules.pub">Published rule sets</A></LI> -</UL> -<LI><A HREF="firewall.html#updown">Calling firewall scripts, named in - ipsec.conf(5)</A></LI> -<UL> -<LI><A HREF="firewall.html#pre_post">Scripts called at IPsec start and - stop</A></LI> -<LI><A HREF="firewall.html#up_down">Scripts called at connection up and - down</A></LI> -<LI><A HREF="firewall.html#ipchains.script">Scripts for ipchains or - iptables</A></LI> -</UL> -<LI><A HREF="firewall.html#NAT">A complication: IPsec vs. NAT</A></LI> -<UL> -<LI><A HREF="firewall.html#nat_ok">NAT on or behind the IPsec gateway - works</A></LI> -<LI><A HREF="firewall.html#nat_bad">NAT between gateways is problematic</A> -</LI> -<LI><A HREF="firewall.html#NAT.ref">Other references on NAT and IPsec</A> -</LI> -</UL> -<LI><A HREF="firewall.html#complications">Other complications</A></LI> -<UL> -<LI><A HREF="firewall.html#through">IPsec through the gateway</A></LI> -<LI><A HREF="firewall.html#ipsec_only">Preventing non-IPsec traffic</A></LI> -<LI><A HREF="firewall.html#unknowngate">Filtering packets from unknown - gateways</A></LI> -</UL> -<LI><A HREF="firewall.html#otherfilter">Other packet filters</A></LI> -<UL> -<LI><A HREF="firewall.html#ICMP">ICMP filtering</A></LI> -<LI><A HREF="firewall.html#traceroute">UDP packets for traceroute</A></LI> -<LI><A HREF="firewall.html#l2tp">UDP for L2TP</A></LI> -</UL> -<LI><A HREF="firewall.html#packets">How it all works: IPsec packet - details</A></LI> -<UL> -<LI><A HREF="firewall.html#noport">ESP and AH do not have ports</A></LI> -<LI><A HREF="firewall.html#header">Header layout</A></LI> -<LI><A HREF="firewall.html#dhr">DHR on the updown script</A></LI> -</UL> -</UL> -<B><A HREF="trouble.html#trouble">Linux FreeS/WAN Troubleshooting Guide</A> -</B> -<UL> -<LI><A HREF="trouble.html#overview">Overview</A></LI> -<LI><A HREF="trouble.html#install">1. During Install</A></LI> -<UL> -<LI><A HREF="trouble.html#8_2_1">1.1 RPM install gotchas</A></LI> -<LI><A HREF="trouble.html#8_2_2">1.2 Problems installing from source</A></LI> -<LI><A HREF="trouble.html#install.check">1.3 Install checks</A></LI> -<LI><A HREF="quickstart.html#oe.trouble">1.3 Troubleshooting OE</A></LI> -</UL> -<LI><A HREF="trouble.html#negotiation">2. During Negotiation</A></LI> -<UL> -<LI><A HREF="trouble.html#state">2.1 Determine Connection State</A></LI> -<LI><A HREF="trouble.html#find.pluto.error">2.2 Finding error text</A></LI> -<LI><A HREF="trouble.html#interpret.pluto.error">2.3 Interpreting a - Negotiation Error</A></LI> -</UL> -<LI><A HREF="trouble.html#use">3. Using a Connection</A></LI> -<UL> -<LI><A HREF="trouble.html#8_4_1">3.1 Orienting yourself</A></LI> -<LI><A HREF="trouble.html#8_4_2">3.2 Those pesky configuration errors</A> -</LI> -<LI><A HREF="trouble.html#route.firewall">3.3 Check Routing and - Firewalling</A></LI> -<LI><A HREF="trouble.html#sniff">3.4 When in doubt, sniff it out</A></LI> -<LI><A HREF="trouble.html#find.use.error">3.5 Check your logs</A></LI> -<LI><A HREF="trouble.html#bigpacket">3.6 More testing for the truly - thorough</A></LI> -</UL> -<LI><A HREF="trouble.html#prob.report">4. Problem Reporting</A></LI> -<UL> -<LI><A HREF="trouble.html#8_5_1">4.1 How to ask for help</A></LI> -<LI><A HREF="trouble.html#8_5_2">4.2 Where to ask</A></LI> -</UL> -<LI><A HREF="trouble.html#notes">5. Additional Notes on Troubleshooting</A> -</LI> -<UL> -<LI><A HREF="trouble.html#system.info">5.1 Information available on your - system</A></LI> -<LI><A HREF="trouble.html#testgates"> 5.2 Testing between security - gateways</A></LI> -<LI><A HREF="trouble.html#ifconfig1">5.3 ifconfig reports for KLIPS - debugging</A></LI> -<LI><A HREF="trouble.html#gdb"> 5.4 Using GDB on Pluto</A></LI> -</UL> -</UL> -<B><A HREF="compat.html#compat">Linux FreeS/WAN Compatibility Guide</A></B> -<UL> -<LI><A HREF="compat.html#spec">Implemented parts of the IPsec - Specification</A></LI> -<UL> -<LI><A HREF="compat.html#in">In Linux FreeS/WAN</A></LI> -<LI><A HREF="compat.html#dropped">Deliberately omitted</A></LI> -<LI><A HREF="compat.html#not">Not (yet) in Linux FreeS/WAN</A></LI> -</UL> -<LI><A HREF="compat.html#pfkey">Our PF-Key implementation</A></LI> -<UL> -<LI><A HREF="compat.html#pfk.port">PF-Key portability</A></LI> -</UL> -<LI><A HREF="compat.html#otherk">Kernels other than the latest 2.2.x and - 2.4.y</A></LI> -<UL> -<LI><A HREF="compat.html#kernel.2.0">2.0.x kernels</A></LI> -<LI><A HREF="compat.html#kernel.production">2.2 and 2.4 kernels</A></LI> -</UL> -<LI><A HREF="compat.html#otherdist">Intel Linux distributions other than - Redhat</A></LI> -<UL> -<LI><A HREF="compat.html#rh7">Redhat 7.0</A></LI> -<LI><A HREF="compat.html#suse">SuSE Linux</A></LI> -<LI><A HREF="compat.html#slack">Slackware</A></LI> -<LI><A HREF="compat.html#deb">Debian</A></LI> -<LI><A HREF="compat.html#caldera">Caldera</A></LI> -</UL> -<LI><A HREF="compat.html#CPUs">CPUs other than Intel</A></LI> -<UL> -<LI><A HREF="compat.html# strongarm">Corel Netwinder (StrongARM CPU)</A></LI> -<LI><A HREF="compat.html#yellowdog">Yellow Dog Linux on Power PC</A></LI> -<LI><A HREF="compat.html#mklinux">Mklinux</A></LI> -<LI><A HREF="compat.html#alpha">Alpha 64-bit processors</A></LI> -<LI><A HREF="compat.html#SPARC">Sun SPARC processors</A></LI> -<LI><A HREF="compat.html#mips">MIPS processors</A></LI> -<LI><A HREF="compat.html#crusoe">Transmeta Crusoe</A></LI> -<LI><A HREF="compat.html#coldfire">Motorola Coldfire</A></LI> -</UL> -<LI><A HREF="compat.html#multiprocessor">Multiprocessor machines</A></LI> -<LI><A HREF="compat.html#hardware">Support for crypto hardware</A></LI> -<LI><A HREF="compat.html#ipv6">IP version 6 (IPng)</A></LI> -<UL> -<LI><A HREF="compat.html#v6.back">IPv6 background</A></LI> -</UL> -</UL> -<B><A HREF="interop.html#10">Interoperating with FreeS/WAN</A></B> -<UL> -<LI><A HREF="interop.html#10_1">Interop at a Glance</A></LI> -<UL> -<LI><A HREF="interop.html#10_1_1">Key</A></LI> -</UL> -<LI><A HREF="interop.html#10_2">Basic Interop Rules</A></LI> -<LI><A HREF="interop.html#10_3">Longer Stories</A></LI> -<UL> -<LI><A HREF="interop.html#10_3_1">For More Compatible Implementations</A> -</LI> -<LI><A HREF="interop.html#10_3_2">For Other Implementations</A></LI> -</UL> -</UL> -<B><A HREF="performance.html#performance">Performance of FreeS/WAN</A></B> -<UL> -<LI><A HREF="performance.html#pub.bench">Published material</A></LI> -<LI><A HREF="performance.html#perf.estimate">Estimating CPU overheads</A> -</LI> -<UL> -<LI><A HREF="performance.html#perf.more">Higher performance alternatives</A> -</LI> -<LI><A HREF="performance.html#11_2_2">Other considerations</A></LI> -</UL> -<LI><A HREF="performance.html#biggate">Many tunnels from a single - gateway</A></LI> -<LI><A HREF="performance.html#low-end">Low-end systems</A></LI> -<LI><A HREF="performance.html#klips.bench">Measuring KLIPS</A></LI> -<LI><A HREF="performance.html#speed.compress">Speed with compression</A></LI> -<LI><A HREF="performance.html#methods">Methods of measuring</A></LI> -</UL> -<B><A HREF="testing.html#test.freeswan">Testing FreeS/WAN</A></B> -<UL> -<LI><A HREF="testing.html#test.oe">Testing opportunistic connections</A></LI> -<UL> -<LI><A HREF="testing.html#12_1_1">Basic OE Test</A></LI> -<LI><A HREF="testing.html#12_1_2">OE Gateway Test</A></LI> -<LI><A HREF="testing.html#12_1_3">Additional OE tests</A></LI> -</UL> -<LI><A HREF="testing.html#test.uml">Testing with User Mode Linux</A></LI> -<LI><A HREF="testing.html#testnet">Configuration for a testbed network</A> -</LI> -<UL> -<LI><A HREF="testing.html#testbed">Testbed network</A></LI> -<LI><A HREF="testing.html#tcpdump.test">Using packet sniffers in testing</A> -</LI> -</UL> -<LI><A HREF="testing.html#verify.crypt">Verifying encryption</A></LI> -<LI><A HREF="testing.html#mail.test">Mailing list pointers</A></LI> -</UL> -<B><A HREF="kernel.html#kernelconfig">Kernel configuration for FreeS/WAN</A> -</B> -<UL> -<LI><A HREF="kernel.html#notall">Not everyone needs to worry about - kernel configuration</A></LI> -<LI><A HREF="kernel.html#assume">Assumptions and notation</A></LI> -<UL> -<LI><A HREF="kernel.html#labels">Labels used</A></LI> -</UL> -<LI><A HREF="kernel.html#kernelopt">Kernel options for FreeS/WAN</A></LI> -</UL> -<B><A HREF="adv_config.html#adv_config">Other configuration - possibilities</A></B> -<UL> -<LI><A HREF="adv_config.html#thumb">Some rules of thumb about - configuration</A></LI> -<UL> -<LI><A HREF="adv_config.html#cheap.tunnel">Tunnels are cheap</A></LI> -<LI><A HREF="adv_config.html#subnet.size">Subnet sizes</A></LI> -<LI><A HREF="adv_config.html#example.more">Other network layouts</A></LI> -</UL> -<LI><A HREF="adv_config.html#choose">Choosing connection types</A></LI> -<UL> -<LI><A HREF="adv_config.html#man-auto">Manual vs. automatic keying</A></LI> -<LI><A HREF="adv_config.html#auto-auth">Authentication methods for - auto-keying</A></LI> -<LI><A HREF="adv_config.html#adv-pk">Advantages of public key methods</A> -</LI> -</UL> -<LI><A HREF="adv_config.html#prodsecrets">Using shared secrets in - production</A></LI> -<UL> -<LI><A HREF="biblio.html#secrets">Putting secrets in ipsec.secrets(5)</A> -</LI> -<LI><A HREF="adv_config.html#securing.secrets">File security</A></LI> -<LI><A HREF="adv_config.html#notroadshared">Shared secrets for road - warriors</A></LI> -</UL> -<LI><A HREF="adv_config.html#prodman">Using manual keying in production</A> -</LI> -<UL> -<LI><A HREF="adv_config.html#ranbits">Creating keys with ranbits</A></LI> -</UL> -<LI><A HREF="adv_config.html#boot">Setting up connections at boot time</A> -</LI> -<LI><A HREF="adv_config.html#multitunnel">Multiple tunnels between the - same two gateways</A></LI> -<UL> -<LI><A HREF="adv_config.html#advroute">One tunnel plus advanced routing</A> -</LI> -</UL> -<LI><A HREF="adv_config.html#opp.gate">An Opportunistic Gateway</A></LI> -<UL> -<LI><A HREF="adv_config.html#14_7_1">Start from full opportunism</A></LI> -<LI><A HREF="adv_config.html#14_7_2">Reverse DNS TXT records for each - protected machine</A></LI> -<LI><A HREF="adv_config.html#14_7_3">Publish your records</A></LI> -<LI><A HREF="adv_config.html#14_7_4">...and test them</A></LI> -<LI><A HREF="adv_config.html#14_7_5">No Configuration Needed</A></LI> -</UL> -<LI><A HREF="adv_config.html#extruded.config">Extruded Subnets</A></LI> -<LI><A HREF="adv_config.html#roadvirt">Road Warrior with virtual IP - address</A></LI> -<LI><A HREF="glossary.html#dynamic">Dynamic Network Interfaces</A></LI> -<UL> -<LI><A HREF="adv_config.html#basicdyn">Basics</A></LI> -<LI><A HREF="adv_config.html#bootdyn">Boot Time</A></LI> -<LI><A HREF="adv_config.html#changedyn">Change Time</A></LI> -</UL> -<LI><A HREF="adv_config.html#unencrypted">Unencrypted tunnels</A></LI> -</UL> -<B><A HREF="trouble.html#install">Installing FreeS/WAN</A></B> -<UL> -<LI><A HREF="install.html#15_1">Requirements</A></LI> -<LI><A HREF="install.html#15_2">Choose your install method</A></LI> -<LI><A HREF="install.html#15_3">FreeS/WAN ships with some Linuxes</A></LI> -<UL> -<LI><A HREF="install.html#15_3_1">FreeS/WAN may be altered...</A></LI> -<LI><A HREF="install.html#15_3_2">You might need to create an - authentication keypair</A></LI> -<LI><A HREF="install.html#15_3_3">Start and test FreeS/WAN</A></LI> -</UL> -<LI><A HREF="install.html#15_4">RPM install</A></LI> -<UL> -<LI><A HREF="install.html#15_4_1">Download RPMs</A></LI> -<LI><A HREF="install.html#15_4_2">For freeswan.org RPMs: check - signatures</A></LI> -<LI><A HREF="install.html#15_4_3">Install the RPMs</A></LI> -<LI><A HREF="install.html#15_4_4">Start and Test FreeS/WAN</A></LI> -</UL> -<LI><A HREF="install.html#15_5">Install from Source</A></LI> -<UL> -<LI><A HREF="install.html#15_5_1">Decide what functionality you need</A></LI> -<LI><A HREF="install.html#15_5_2">Download FreeS/WAN</A></LI> -<LI><A HREF="install.html#15_5_3">For freeswan.org source: check its - signature</A></LI> -<LI><A HREF="install.html#15_5_4">Untar, unzip</A></LI> -<LI><A HREF="install.html#15_5_5">Patch if desired</A></LI> -<LI><A HREF="install.html#15_5_6">... and Make</A></LI> -</UL> -<LI><A HREF="install.html#15_6">Start FreeS/WAN and test your install</A> -</LI> -<LI><A HREF="install.html#15_7">Test your install</A></LI> -<LI><A HREF="install.html#15_8">Making FreeS/WAN play well with others</A> -</LI> -<LI><A HREF="install.html#15_9">Configure for your needs</A></LI> -</UL> -<B><A HREF="config.html#config">How to configure FreeS/WAN</A></B> -<UL> -<LI><A HREF="config.html#16_1">Requirements</A></LI> -<LI><A HREF="config.html#config.netnet">Net-to-Net connection</A></LI> -<UL> -<LI><A HREF="config.html#netnet.info.ex">Gather information</A></LI> -<LI><A HREF="config.html#16_2_2">Edit /etc/ipsec.conf</A></LI> -<LI><A HREF="config.html#16_2_3">Start your connection</A></LI> -<LI><A HREF="config.html#16_2_4">Do not MASQ or NAT packets to be - tunneled</A></LI> -<LI><A HREF="config.html#16_2_5">Test your connection</A></LI> -<LI><A HREF="config.html#16_2_6">Finishing touches</A></LI> -</UL> -<LI><A HREF="config.html#config.rw">Road Warrior Configuration</A></LI> -<UL> -<LI><A HREF="config.html#rw.info.ex">Gather information</A></LI> -<LI><A HREF="config.html#16_3_2">Customize /etc/ipsec.conf</A></LI> -<LI><A HREF="config.html#16_3_3">Start your connection</A></LI> -<LI><A HREF="config.html#16_3_4">Do not MASQ or NAT packets to be - tunneled</A></LI> -<LI><A HREF="config.html#16_3_5">Test your connection</A></LI> -<LI><A HREF="config.html#16_3_6">Finishing touches</A></LI> -<LI><A HREF="config.html#16_3_7">Multiple Road Warriors</A></LI> -</UL> -<LI><A HREF="config.html#16_4">What next?</A></LI> -</UL> -<B><A HREF="background.html#background">Linux FreeS/WAN background</A></B> -<UL> -<LI><A HREF="background.html#dns.background">Some DNS background</A></LI> -<UL> -<LI><A HREF="background.html#forward.reverse">Forward and reverse maps</A> -</LI> -<LI><A HREF="background.html#17_1_2">Hierarchy and delegation</A></LI> -<LI><A HREF="background.html#17_1_3">Syntax of DNS records</A></LI> -<LI><A HREF="background.html#17_1_4">Cacheing, TTL and propagation delay</A> -</LI> -</UL> -<LI><A HREF="background.html#MTU.trouble">Problems with packet - fragmentation</A></LI> -<LI><A HREF="background.html#nat.background">Network address translation - (NAT)</A></LI> -<UL> -<LI><A HREF="background.html#17_3_1">NAT to non-routable addresses</A></LI> -<LI><A HREF="background.html#17_3_2">NAT to routable addresses</A></LI> -</UL> -</UL> -<B><A HREF="user_examples.html#user.examples">FreeS/WAN script examples</A> -</B> -<UL> -<LI><A HREF="user_examples.html#poltorak">Poltorak's Firewall script</A></LI> -</UL> -<B><A HREF="makecheck.html#makecheck">How to configure to use "make - check"</A></B> -<UL> -<LI><A HREF="makecheck.html#19_1">What is "make check"</A></LI> -<LI><A HREF="makecheck.html#19_2">Running "make check"</A></LI> -</UL> -<B><A HREF="makecheck.html#20">How to write a "make check" test</A></B> -<UL> -<LI><A HREF="makecheck.html#20_1">Structure of a test</A></LI> -<LI><A HREF="makecheck.html#20_2">The TESTLIST</A></LI> -<LI><A HREF="makecheck.html#20_3">Test kinds</A></LI> -<LI><A HREF="makecheck.html#20_4">Common parameters</A></LI> -<LI><A HREF="makecheck.html#20_5">KLIPStest paramaters</A></LI> -<LI><A HREF="makecheck.html#20_6">mkinsttest paramaters</A></LI> -<LI><A HREF="makecheck.html#20_7">rpm_build_install_test paramaters</A></LI> -<LI><A HREF="makecheck.html#20_8">libtest paramaters</A></LI> -<LI><A HREF="makecheck.html#20_9">umlplutotest paramaters</A></LI> -<LI><A HREF="makecheck.html#20_10">umlXhost parameters</A></LI> -<LI><A HREF="makecheck.html#20_11">kernel_patch_test paramaters</A></LI> -<LI><A HREF="makecheck.html#20_12">module_compile paramaters</A></LI> -</UL> -<B><A HREF="makecheck.html#21">Current pitfalls</A></B> -<BR> -<BR><B><A HREF="umltesting.html#umltesting">User-Mode-Linux Testing - guide</A></B> -<UL> -<LI><A HREF="umltesting.html#22_1">Preliminary Notes on BIND</A></LI> -<LI><A HREF="umltesting.html#22_2">Steps to Install UML for FreeS/WAN</A> -</LI> -</UL> -<B><A HREF="umltesting.html#23">Debugging the kernel with GDB</A></B> -<UL> -<LI><A HREF="umltesting.html#23_1">Other notes about debugging</A></LI> -</UL> -<B><A HREF="umltesting.html#24">User-Mode-Linux mysteries</A></B> -<BR> -<BR><B><A HREF="umltesting.html#25">Getting more info from uml_netjig</A> -</B> -<BR> -<BR><B><A HREF="politics.html#politics">History and politics of - cryptography</A></B> -<UL> -<LI><A HREF="politics.html#intro.politics">Introduction</A></LI> -<UL> -<LI><A HREF="politics.html#26_1_1">History</A></LI> -<LI><A HREF="politics.html#intro.poli">Politics</A></LI> -<LI><A HREF="politics.html#26_1_3">Links</A></LI> -<LI><A HREF="politics.html#26_1_4">Outline of this section</A></LI> -</UL> -<LI><A HREF="politics.html#leader">From our project leader</A></LI> -<UL> -<LI><A HREF="politics.html#gilmore">Swan: Securing the Internet against - Wiretapping</A></LI> -<LI><A HREF="politics.html#policestate">Stopping wholesale monitoring</A> -</LI> -</UL> -<LI><A HREF="politics.html#weak">Government promotion of weak crypto</A></LI> -<UL> -<LI><A HREF="politics.html#escrow">Escrowed encryption</A></LI> -<LI><A HREF="politics.html#shortkeys">Limited key lengths</A></LI> -</UL> -<LI><A HREF="politics.html#exlaw">Cryptography Export Laws</A></LI> -<UL> -<LI><A HREF="politics.html#USlaw">US Law</A></LI> -<LI><A HREF="politics.html#wrong">What's wrong with restrictions on - cryptography</A></LI> -<LI><A HREF="politics.html#Wassenaar">The Wassenaar Arrangement</A></LI> -<LI><A HREF="politics.html#status">Export status of Linux FreeS/WAN</A></LI> -<LI><A HREF="politics.html#help">Help spread IPsec around</A></LI> -</UL> -<LI><A HREF="politics.html#desnotsecure">DES is Not Secure</A></LI> -<UL> -<LI><A HREF="politics.html#deshware">Dedicated hardware breaks DES in a - few days</A></LI> -<LI><A HREF="politics.html#spooks">Spooks may break DES faster yet</A></LI> -<LI><A HREF="politics.html#desnet">Networks break DES in a few weeks</A></LI> -<LI><A HREF="politics.html#no_des">We disable DES</A></LI> -<LI><A HREF="politics.html#40joke">40-bits is laughably weak</A></LI> -<LI><A HREF="politics.html#altdes">Triple DES is almost certainly secure</A> -</LI> -<LI><A HREF="politics.html#aes.ipsec">AES in IPsec</A></LI> -</UL> -<LI><A HREF="politics.html#press">Press coverage of Linux FreeS/WAN:</A></LI> -<UL> -<LI><A HREF="politics.html#26_6_1">FreeS/WAN 1.0 press</A></LI> -<LI><A HREF="faq.html#release">Press release for version 1.0</A></LI> -</UL> -</UL> -<B><A HREF="ipsec.html#ipsec.detail">The IPsec protocols</A></B> -<UL> -<LI><A HREF="ipsec.html#27_1">Protocols and phases</A></LI> -<LI><A HREF="ipsec.html#others">Applying IPsec</A></LI> -<UL> -<LI><A HREF="ipsec.html#advantages">Advantages of IPsec</A></LI> -<LI><A HREF="ipsec.html#limitations">Limitations of IPsec</A></LI> -<LI><A HREF="ipsec.html#uses">IPsec is a general mechanism for securing - IP</A></LI> -<LI><A HREF="ipsec.html#authonly">Using authentication without - encryption</A></LI> -<LI><A HREF="ipsec.html#encnoauth">Encryption without authentication is - dangerous</A></LI> -<LI><A HREF="ipsec.html#multilayer">Multiple layers of IPsec processing - are possible</A></LI> -<LI><A HREF="ipsec.html#traffic.resist">Resisting traffic analysis</A></LI> -</UL> -<LI><A HREF="ipsec.html#primitives">Cryptographic components</A></LI> -<UL> -<LI><A HREF="ipsec.html#block.cipher">Block ciphers</A></LI> -<LI><A HREF="ipsec.html#hash.ipsec">Hash functions</A></LI> -<LI><A HREF="ipsec.html#DH.keying">Diffie-Hellman key agreement</A></LI> -<LI><A HREF="ipsec.html#RSA.auth">RSA authentication</A></LI> -</UL> -<LI><A HREF="ipsec.html#structure">Structure of IPsec</A></LI> -<UL> -<LI><A HREF="ipsec.html#IKE.ipsec">IKE (Internet Key Exchange)</A></LI> -<LI><A HREF="ipsec.html#services">IPsec Services, AH and ESP</A></LI> -<LI><A HREF="ipsec.html#AH.ipsec">The Authentication Header (AH)</A></LI> -<LI><A HREF="ipsec.html#ESP.ipsec">Encapsulated Security Payload (ESP)</A> -</LI> -</UL> -<LI><A HREF="ipsec.html#modes">IPsec modes</A></LI> -<UL> -<LI><A HREF="ipsec.html#tunnel.ipsec">Tunnel mode</A></LI> -<LI><A HREF="ipsec.html#transport.ipsec">Transport mode</A></LI> -</UL> -<LI><A HREF="ipsec.html#parts">FreeS/WAN parts</A></LI> -<UL> -<LI><A HREF="ipsec.html#KLIPS.ipsec">KLIPS: Kernel IPsec Support</A></LI> -<LI><A HREF="ipsec.html#Pluto.ipsec">The Pluto daemon</A></LI> -<LI><A HREF="ipsec.html#command">The ipsec(8) command</A></LI> -<LI><A HREF="ipsec.html#ipsec.conf">Linux FreeS/WAN configuration file</A> -</LI> -</UL> -<LI><A HREF="ipsec.html#key">Key management</A></LI> -<UL> -<LI><A HREF="ipsec.html#current">Currently Implemented Methods</A></LI> -<LI><A HREF="ipsec.html#notyet">Methods not yet implemented</A></LI> -</UL> -</UL> -<B><A HREF="mail.html#lists">Mailing lists and newsgroups</A></B> -<UL> -<LI><A HREF="mail.html#list.fs">Mailing lists about FreeS/WAN</A></LI> -<UL> -<LI><A HREF="mail.html#projlist">The project mailing lists</A></LI> -<LI><A HREF="mail.html#archive">Archives of the lists</A></LI> -</UL> -<LI><A HREF="mail.html#indexes">Indexes of mailing lists</A></LI> -<LI><A HREF="mail.html#otherlists">Lists for related software and topics</A> -</LI> -<UL> -<LI><A HREF="mail.html#28_3_1">Products that include FreeS/WAN</A></LI> -<LI><A HREF="mail.html#linux.lists">Linux mailing lists</A></LI> -<LI><A HREF="mail.html#ietf">Lists for IETF working groups</A></LI> -<LI><A HREF="mail.html#other">Other mailing lists</A></LI> -</UL> -<LI><A HREF="mail.html#newsgroups">Usenet newsgroups</A></LI> -</UL> -<B><A HREF="web.html#weblink">Web links</A></B> -<UL> -<LI><A HREF="web.html#freeswan">The Linux FreeS/WAN Project</A></LI> -<UL> -<LI><A HREF="web.html#patch">Add-ons and patches for FreeS/WAN</A></LI> -<LI><A HREF="web.html#dist">Distributions including FreeS/WAN</A></LI> -<LI><A HREF="web.html#used">Things FreeS/WAN uses or could use</A></LI> -<LI><A HREF="web.html#alternatives">Other approaches to VPNs for Linux</A> -</LI> -</UL> -<LI><A HREF="web.html#ipsec.link">The IPsec Protocols</A></LI> -<UL> -<LI><A HREF="web.html#general">General IPsec or VPN information</A></LI> -<LI><A HREF="trouble.html#overview">IPsec overview documents or slide - sets</A></LI> -<LI><A HREF="web.html#otherlang">IPsec information in languages other - than English</A></LI> -<LI><A HREF="web.html#RFCs1">RFCs and other reference documents</A></LI> -<LI><A HREF="web.html#analysis">Analysis and critiques of IPsec - protocols</A></LI> -<LI><A HREF="web.html#IP.background">Background information on IP</A></LI> -</UL> -<LI><A HREF="web.html#implement">IPsec Implementations</A></LI> -<UL> -<LI><A HREF="web.html#linuxprod">Linux products</A></LI> -<LI><A HREF="web.html#router">IPsec in router products</A></LI> -<LI><A HREF="web.html#fw.web">IPsec in firewall products</A></LI> -<LI><A HREF="web.html#ipsecos">Operating systems with IPsec support</A></LI> -<LI><A HREF="web.html#29_3_5">IPsec on network cards</A></LI> -<LI><A HREF="web.html#opensource">Open source IPsec implementations</A></LI> -<LI><A HREF="web.html#interop.web">Interoperability</A></LI> -</UL> -<LI><A HREF="web.html#linux.link">Linux links</A></LI> -<UL> -<LI><A HREF="web.html#linux.basic">Basic and tutorial Linux information</A> -</LI> -<LI><A HREF="web.html#general">General Linux sites</A></LI> -<LI><A HREF="web.html#docs.ldp">Documentation</A></LI> -<LI><A HREF="web.html#advroute.web">Advanced routing</A></LI> -<LI><A HREF="web.html#linsec">Security for Linux</A></LI> -<LI><A HREF="web.html#firewall.linux">Linux firewalls</A></LI> -<LI><A HREF="web.html#linux.misc">Miscellaneous Linux information</A></LI> -</UL> -<LI><A HREF="web.html#crypto.link">Crypto and security links</A></LI> -<UL> -<LI><A HREF="web.html#security">Crypto and security resources</A></LI> -<LI><A HREF="web.html#policy">Cryptography law and policy</A></LI> -<LI><A HREF="web.html#crypto.tech">Cryptography technical information</A> -</LI> -<LI><A HREF="web.html#compsec">Computer and network security</A></LI> -<LI><A HREF="web.html#people">Links to home pages</A></LI> -</UL> -</UL> -<B><A HREF="glossary.html#ourgloss">Glossary for the Linux FreeS/WAN - project</A></B> -<UL> -<LI><A HREF="glossary.html#jump">Jump to a letter in the glossary</A></LI> -<LI><A HREF="glossary.html#gloss">Other glossaries</A></LI> -<LI><A HREF="glossary.html#definitions">Definitions</A></LI> -</UL> -<B><A HREF="biblio.html#biblio">Bibliography for the Linux FreeS/WAN - project</A></B> -<BR> -<BR><B><A HREF="rfc.html#RFC">IPsec RFCs and related documents</A></B> -<UL> -<LI><A HREF="rfc.html#RFCfile">The RFCs.tar.gz Distribution File</A></LI> -<LI><A HREF="rfc.html#sources">Other sources for RFCs & Internet drafts</A> -</LI> -<UL> -<LI><A HREF="rfc.html#RFCdown">RFCs</A></LI> -<LI><A HREF="rfc.html#drafts">Internet Drafts</A></LI> -<LI><A HREF="rfc.html#FIPS1">FIPS standards</A></LI> -</UL> -<LI><A HREF="rfc.html#RFCs.tar.gz">What's in the RFCs.tar.gz bundle?</A></LI> -<UL> -<LI><A HREF="rfc.html#rfc.ov">Overview RFCs</A></LI> -<LI><A HREF="rfc.html#basic.prot">Basic protocols</A></LI> -<LI><A HREF="rfc.html#key.ike">Key management</A></LI> -<LI><A HREF="rfc.html#rfc.detail">Details of various things used</A></LI> -<LI><A HREF="rfc.html#rfc.ref">Older RFCs which may be referenced</A></LI> -<LI><A HREF="rfc.html#rfc.dns">RFCs for secure DNS service, which IPsec - may use</A></LI> -<LI><A HREF="rfc.html#rfc.exp">RFCs labelled "experimental"</A></LI> -<LI><A HREF="rfc.html#rfc.rel">Related RFCs</A></LI> -</UL> -</UL> -<B><A HREF="roadmap.html#roadmap">Distribution Roadmap: What's Where in - Linux FreeS/WAN</A></B> -<UL> -<LI><A HREF="roadmap.html#top">Top directory</A></LI> -<LI><A HREF="roadmap.html#doc">Documentation</A></LI> -<LI><A HREF="roadmap.html#klips.roadmap">KLIPS: kernel IP security</A></LI> -<LI><A HREF="roadmap.html#pluto.roadmap">Pluto key and connection - management daemon</A></LI> -<LI><A HREF="roadmap.html#utils">Utils</A></LI> -<LI><A HREF="roadmap.html#lib">Libraries</A></LI> -<UL> -<LI><A HREF="roadmap.html#fswanlib">FreeS/WAN Library</A></LI> -<LI><A HREF="roadmap.html#otherlib">Imported Libraries</A></LI> -</UL> -</UL> -<B><A HREF="umltesting.html#umltesting">User-Mode-Linux Testing guide</A> -</B> -<UL> -<LI><A HREF="umltesting.html#34_1">Preliminary Notes on BIND</A></LI> -<LI><A HREF="umltesting.html#34_2">Steps to Install UML for FreeS/WAN</A> -</LI> -</UL> -<B><A HREF="umltesting.html#35">Debugging the kernel with GDB</A></B> -<UL> -<LI><A HREF="umltesting.html#35_1">Other notes about debugging</A></LI> -</UL> -<B><A HREF="umltesting.html#36">User-Mode-Linux mysteries</A></B> -<BR> -<BR><B><A HREF="umltesting.html#37">Getting more info from uml_netjig</A> -</B> -<BR> -<BR><B><A HREF="makecheck.html#makecheck">How to configure to use "make - check"</A></B> -<UL> -<LI><A HREF="makecheck.html#38_1">What is "make check"</A></LI> -<LI><A HREF="makecheck.html#38_2">Running "make check"</A></LI> -</UL> -<B><A HREF="makecheck.html#39">How to write a "make check" test</A></B> -<UL> -<LI><A HREF="makecheck.html#39_1">Structure of a test</A></LI> -<LI><A HREF="makecheck.html#39_2">The TESTLIST</A></LI> -<LI><A HREF="makecheck.html#39_3">Test kinds</A></LI> -<LI><A HREF="makecheck.html#39_4">Common parameters</A></LI> -<LI><A HREF="makecheck.html#39_5">KLIPStest paramaters</A></LI> -<LI><A HREF="makecheck.html#39_6">mkinsttest paramaters</A></LI> -<LI><A HREF="makecheck.html#39_7">rpm_build_install_test paramaters</A></LI> -<LI><A HREF="makecheck.html#39_8">libtest paramaters</A></LI> -<LI><A HREF="makecheck.html#39_9">umlplutotest paramaters</A></LI> -<LI><A HREF="makecheck.html#39_10">umlXhost parameters</A></LI> -<LI><A HREF="makecheck.html#39_11">kernel_patch_test paramaters</A></LI> -<LI><A HREF="makecheck.html#39_12">module_compile paramaters</A></LI> -</UL> -<B><A HREF="makecheck.html#40">Current pitfalls</A></B> -<BR> -<BR><B><A HREF="nightly.html#nightly">Nightly regression testing</A></B> -<BR> -<BR><B><A HREF="nightly.html#nightlyhowto">How to setup the nightly - build</A></B> -<UL> -<LI><A HREF="nightly.html#42_1"> Files you need to know about</A></LI> -<LI><A HREF="nightly.html#42_2">Configuring freeswan-regress-env.sh</A></LI> -</UL> -</BODY> -</HTML> diff --git a/doc/trouble.html b/doc/trouble.html deleted file mode 100644 index 2123f3805..000000000 --- a/doc/trouble.html +++ /dev/null @@ -1,706 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="firewall.html">Previous</A> -<A HREF="compat.html">Next</A> -<HR> -<H1><A NAME="trouble"></A>Linux FreeS/WAN Troubleshooting Guide</H1> -<H2><A NAME="overview"></A>Overview</H2> -<P> This document covers several general places where you might have a - problem:</P> -<OL> -<LI><A HREF="#install">During install</A>.</LI> -<LI><A HREF="#negotiation">During the negotiation process</A>.</LI> -<LI><A HREF="#use">Using an established connection</A>.</LI> -</OL> -<P>This document also contains<A HREF="#notes"> notes</A> which expand - on points made in these sections, and tips for<A HREF="#prob.report"> - problem reporting</A>. If the other end of your connection is not - FreeS/WAN, you'll also want to read our<A HREF="interop.html#interop.problem"> - interoperation</A> document.</P> -<H2><A NAME="install"></A>1. During Install</H2> -<H3><A NAME="8_2_1">1.1 RPM install gotchas</A></H3> -<P>With the RPM method:</P> -<UL> -<LI>Be sure you have installed both the userland tools and the kernel - components. One will not work without the other. For example, when - using FreeS/WAN-produced RPMs for our 2.04 release, you need both: -<PRE> freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm - freeswan-module-2.04_2.4.20_20.9-0.i386.rpm -</PRE> -</LI> -</UL> -<H3><A NAME="8_2_2">1.2 Problems installing from source</A></H3> -<P>When installing from source, you may find these problems:</P> -<UL> -<LI>Missing library. See<A HREF="faq.html#gmp.h_missing"> this</A> FAQ.</LI> -<LI>Missing utilities required for compile. See this<A HREF="install.html#tool.lib"> - checklist</A>.</LI> -<LI>Kernel version incompatibility. See<A HREF="faq.html#k.versions"> - this</A> FAQ.</LI> -<LI>Another compile problem. Find information in the out.* files, ie. - out.kpatch, out.kbuild, created at compile time in the top-level Linux - FreeS/WAN directory. Error messages generated by KLIPS during the boot - sequence are accessible with the<VAR> dmesg</VAR> command. -<BR> Check the list archives and the List in Brief to see if this is a - known issue. If it is not, report it to the bugs list as described in - our<A HREF="#prob.report"> problem reporting</A> section. In some - cases, you may be asked to provide debugging information using gdb; - details<A HREF="#gdb"> below</A>.</LI> -<LI>If your kernel compiles but you fail to install your new - FreeS/WAN-enabled kernel, review the sections on<A HREF="install.html#newk"> - installing the patched kernel</A>, and<A HREF="install.html#testinstall"> - testing</A> to see if install succeeded.</LI> -</UL> -<H3><A NAME="install.check"></A>1.3 Install checks</H3> -<P><VAR>ipsec verify</VAR> checks a number of FreeS/WAN essentials. Here - are some hints on what do to when your system doesn't check out:</P> -<P></P> -<TABLE border="1"> -<TR><TD><STRONG>Problem</STRONG></TD><TD><STRONG>Status</STRONG></TD><TD> -<STRONG>Action</STRONG></TD></TR> -<TR><TD><VAR>ipsec</VAR> not on-path</TD><TD> </TD><TD> -<P>Add<VAR> /usr/local/sbin</VAR> to your PATH.</P> -</TD></TR> -<TR><TD>Missing KLIPS support</TD><TD><FONT COLOR="#FF0000">critical</FONT> -</TD><TD>See<A HREF="faq.html#noKLIPS"> this FAQ.</A></TD></TR> -<TR><TD>No RSA private key</TD><TD> </TD><TD> -<P>Follow<A HREF="install.html#genrsakey"> these instructions</A> to - create an RSA key pair for your host. RSA keys are:</P> -<UL> -<LI>required for opportunistic encryption, and</LI> -<LI>our preferred method to authenticate pre-configured connections.</LI> -</UL> -</TD></TR> -<TR><TD><VAR>pluto</VAR> not running</TD><TD><FONT COLOR="#FF0000"> -critical</FONT></TD><TD> -<PRE>service ipsec start</PRE> -</TD></TR> -<TR><TD>No port 500 hole</TD><TD><FONT COLOR="#FF0000">critical</FONT></TD><TD> -Open port 500 for IKE negotiation.</TD></TR> -<TR><TD>Port 500 check N/A</TD><TD> </TD><TD>Check that port 500 is open - for IKE negotiation.</TD></TR> -<TR><TD>Failed DNS checks</TD><TD> </TD><TD>Opportunistic encryption - requires information from DNS. To set this up, see<A HREF="quickstart.html#opp.setup"> - our instructions</A>.</TD></TR> -<TR><TD>No public IP address</TD><TD> </TD><TD>Check that the interface - which you want to protect with IPSec is up and running.</TD></TR> -</TABLE> -<H3><A NAME="oe.trouble"></A>1.3 Troubleshooting OE</H3> -<P>OE should work with no local configuration, if you have posted DNS - TXT records according to the instructions in our<A HREF="quickstart.html"> - quickstart guide</A>. If you encounter trouble, try these hints. We - welcome additional hints via the<A HREF="mail.html"> users' mailing - list</A>.</P> -<TABLE border="1"> -<TR><TD><STRONG>Symptom</STRONG></TD><TD><STRONG>Problem</STRONG></TD><TD> -<STRONG>Action</STRONG></TD></TR> -<TR><TD> You're running FreeS/WAN 2.01 (or later), and initiating a - connection to FreeS/WAN 2.00 (or earlier). In your logs, you see a - message like: -<PRE>no RSA public key known for '192.0.2.13'; -DNS search for KEY failed (no KEY record -for 13.2.0.192.in-addr.arpa.)</PRE> - The older FreeS/WAN logs no error.</TD><TD><A NAME="oe.trouble.flagday"> -</A> A protocol level incompatibility between 2.01 (or later) and 2.00 - (or earlier) causes this error. It occurs when a FreeS/WAN 2.01 (or - later) box for which no KEY record is posted attempts to initiate an OE - connection to older FreeS/WAN versions (2.00 and earlier). Note that - older versions can initiate to newer versions without this error.</TD><TD> -If you control the peer host, upgrade its FreeS/WAN to 2.01 (or later), - and post new style TXT records for it. If not, but if you know its - sysadmin, perhaps a quick note is in order. If neither option is - possible, you can ease the transition by posting an old style KEY - record (created with a command like "ipsec showhostkey --key") to the - reverse map for the FreeS/WAN 2.01 (or later) box.</TD></TR> -<TR><TD>OE host is very slow to contact other hosts.</TD><TD>Slow DNS - service while running OE.</TD><TD>It's a good idea to run a caching DNS - server on your OE host, as outlined in<A HREF="http://lists.freeswan.org/pipermail/design/2003-January/004205.html"> - this mailing list message</A>. If your DNS servers are elsewhere, put - their IPs in the<VAR> clear</VAR> policy group, and re-read groups with -<PRE>ipsec auto --rereadgroups</PRE> -</TD></TR> -<TR><TD> -<PRE>Can't Opportunistically initiate for -192.0.2.2 to 192.0.2.3: no TXT record -for 13.2.0.192.in-addr.arpa.</PRE> -</TD><TD>Peer is not set up for OE.</TD><TD> -<P>None. Plenty of hosts on the Internet do not run OE. If, however, you - have set OE up on that peer, this may indicate that you need to wait up - to 48 hours for its DNS records to propagate.</P> -</TD></TR> -<TR><TD><VAR>ipsec verify</VAR> does not find DNS records: -<PRE>... -Looking for TXT in forward map: - xy.example.com...[FAILED] -Looking for TXT in reverse map...[FAILED] -...</PRE> - You also experience authentication failure: -<BR> -<PRE>Possible authentication failure: -no acceptable response to our -first encrypted message</PRE> -</TD><TD>DNS records are not posted or have not propagated.</TD><TD>Did - you post the DNS records necessary for OE? If not, do so using the - instructions in our<A HREF="quickstart.html#quickstart"> quickstart - guide</A>. If so, wait up to 48 hours for the DNS records to propagate.</TD> -</TR> -<TR><TD><VAR>ipsec verify</VAR> does not find DNS records, and you - experience authentication failure.</TD><TD>For iOE, your ID does not - match location of forward DNS record.</TD><TD>In<VAR> config setup</VAR> -, change<VAR> myid=</VAR> to match the forward DNS where you posted the - record. Restart FreeS/WAN. For reference, see our<A HREF="quickstart.html#opp.client"> - iOE instructions</A>.</TD></TR> -<TR><TD><VAR>ipsec verify</VAR> finds DNS records, yet there is still - authentication failure. ( ? )</TD><TD>DNS records are malformed.</TD><TD> -Re-create the records and send new copies to your DNS administrator.</TD> -</TR> -<TR><TD><VAR>ipsec verify</VAR> finds DNS records, yet there is still - authentication failure. ( ? )</TD><TD>DNS records show different keys - for a gateway vs. its subnet hosts.</TD><TD>All TXT records for boxes - protected by an OE gateway must contain the gateway's public key. - Re-create and re-post any incorrect records using<A HREF="quickstart.html#opp.incoming"> - these instructions</A>.</TD></TR> -<TR><TD>OE gateway loses connectivity to its subnet. The gateway's - routing table shows routes to the subnet through IPsec interfaces.</TD><TD> -The subnet is part of the<VAR> private</VAR> or<VAR> block</VAR> policy - group on the gateway.</TD><TD>Remove the subnet from the group, and - reread groups with -<PRE>ipsec auto --rereadgroups</PRE> -</TD></TR> -<TR><TD>OE does not work to hosts on the local LAN.</TD><TD>This is a - known issue.</TD><TD>See<A HREF="opportunism.known-issues"> this list</A> - of known issues with OE.</TD></TR> -<TR><TD>FreeS/WAN does not seem to be executing your default policy. In - your logs, you see a message like: -<PRE>/etc/ipsec.d/policies/iprivate-or-clear" -line 14: subnet "0.0.0.0/0", -source 192.0.2.13/32, -already "private-or-clear"</PRE> -</TD><TD><A HREF="glossary.html#fullnet">Fullnet</A> in a policy group - file defines your default policy. Fullnet should normally be present in - only one policy group file. The fine print: you can have two default - policies defined so long as they protect different local endpoints - (e.g. the FreeS/WAN gateway and a subnet).</TD><TD> Find all policies - which contain fullnet with: -<BR> -<PRE>grep -F 0.0.0.0/0 /etc/ipsec.d/policies/*</PRE> - then remove the unwanted occurrence(s).</TD></TR> -</TABLE> -<H2><A NAME="negotiation"></A>2. During Negotiation</H2> -<P>When you fail to bring up a tunnel, you'll need to find out:</P> -<UL> -<LI><A HREF="#state">what your connection state is,</A> and often</LI> -<LI><A HREF="#find.pluto.error">an error message</A>.</LI> -</UL> -<P>before you can<A HREF="#interpret.pluto.error"> diagnose your problem</A> -.</P> -<H3><A NAME="state"></A>2.1 Determine Connection State</H3> -<H4>Finding current state</H4> -<P>You can see connection states (STATE_MAIN_I1 and so on) when you - bring up a connection on the command line. If you have missed this, or - brought up your connection automatically, use:</P> -<PRE>ipsec auto --status</PRE> -<P>The most relevant state is the last one reached.</P> -<H4><VAR>What's this supposed to look like?</VAR></H4> -<P>Negotiations should proceed though various states, in the processes - of:</P> -<OL> -<LI>IKE negotiations (aka Phase 1, Main Mode, STATE_MAIN_*)</LI> -<LI>IPSEC negotiations (aka Phase 2, Quick Mode, STATE_QUICK_*)</LI> -</OL> -<P>These are done and a connection is established when you see messages - like:</P> -<PRE> 000 #21: "myconn" STATE_MAIN_I4 (ISAKMP SA established)... - 000 #2: "myconn" STATE_QUICK_I2 (sent QI2, IPsec SA established)...</PRE> -<P> Look for the key phrases are "ISAKMP SA established" and "IPSec SA - established", with the relevant connection name. Often, this happens at - STATE_MAIN_I4 and STATE_QUICK_I2, respectively.</P> -<P><VAR>ipsec auto --status</VAR> will tell you what states<STRONG> have - been achieved</STRONG>, rather than the current state. Since - determining the current state is rather more difficult to do, current - state information is not available from Linux FreeS/WAN. If you are - actively bringing a connection up, the status report's last states for - that connection likely reflect its current state. Beware, though, of - the case where a connection was correctly brought up but is now downed: - Linux FreeS/WAN will not notice this until it attempts to rekey. - Meanwhile, the last known state indicates that the connection has been - established.</P> -<P>If your connection is stuck at STATE_MAIN_I1, skip straight to<A HREF="#ikepath"> - here</A>.</P> -<H3><A NAME="find.pluto.error"></A>2.2 Finding error text</H3> -<P>Solving most errors will require you to find verbose error text, - either on the command line or in the logs.</P> -<H4>Verbose start for more information</H4> -<P> Note that you can get more detail from<VAR> ipsec auto</VAR> using - the --verbose flag:</P> -<PRE STYLE="margin-bottom: 0.2in"> ipsec auto --verbose --up west-east</PRE> -<P> More complete information can be gleaned from the<A HREF="#logusage"> - log files</A>.</P> -<H4>Debug levels count</H4> -<P>The amount of description you'll get here depends on ipsec.conf debug - settings,<VAR> klipsdebug</VAR>= and<VAR> plutodebug</VAR>=. When - troubleshooting, set at least one of these to<VAR> all</VAR>, and when - done, reset it to<VAR> none</VAR> so your logs don't fill up. Note that - you must have enabled the<VAR> klipsdebug</VAR><A HREF="install.html#allbut"> - compile-time option</A> for the<VAR> klipsdebug</VAR> configuration - switch to work.</P> -<P>For negotiation problems<VAR> plutodebug</VAR> is most relevant.<VAR> - klipsdebug</VAR> applies mainly to attempts to use an - already-established connection. See also<A HREF="ipsec.html#parts"> - this</A> description of the division of duties within Linux FreeS/WAN.</P> -<P>After raising your debug levels, restart Linux FreeS/WAN to ensure - that ipsec.conf is reread, then recreate the error to generate verbose - logs.</P> -<H4><VAR>ipsec barf</VAR> for lots of debugging information</H4> -<P><A HREF="manpage.d/ipsec_barf.8.html"><VAR> ipsec barf (8)</VAR></A> - collects a bunch of useful debugging information, including these logs - Use the command</P> -<PRE> - ipsec barf > barf.west -</PRE> -<P>to generate one.</P> -<H4>Find the error</H4> -<P>Search out the failure point in your logs. Are there a handful of - lines which succinctly describe how things are going wrong or contrary - to your expectation? Sometimes the failure point is not immediately - obvious: Linux FreeS/WAN's errors are usually not marked "Error". Have - a look in the<A HREF="faq.html"> FAQ</A> for what some common failures - look like.</P> -<P>Tip: problems snowball. Focus your efforts on the first problem, - which is likely to be the cause of later errors.</P> -<H4>Play both sides</H4> -<P>Also find error text on the peer IPSec box. This gives you two - perspectives on the same failure.</P> -<P>At times you will require information which only one side has. The - peer can merely indicate the presence of an error, and its approximate - point in the negotiations. If one side keeps retrying, it may be - because there is a show stopper on the other side. Have a look at the - other side and figure out what it doesn't like.</P> -<P>If the other end is not Linux FreeS/WAN, the principle is the same: - replicate the error with its most verbose logging on, and capture the - output to a file.</P> -<H3><A NAME="interpret.pluto.error"></A>2.3 Interpreting a Negotiation - Error</H3> -<H4><A NAME="ikepath"></A>Connection stuck at STATE_MAIN_I1</H4> -<P>This error commonly happens because IKE (port 500) packets, needed to - negotiate an IPSec connection, cannot travel freely between your IPSec - gateways. See<A HREF="firewall.html#packets"> our firewall document</A> - for details.</P> -<H4>Other errors</H4> -<P>Other errors require a bit more digging. Use the following resources:</P> -<UL> -<LI><A HREF="faq.html">the FAQ</A> . Since this document is constantly - updated, the snapshot's FAQ may have a new entry relevant to your - problem.</LI> -<LI>our<A HREF="background.html"> background document</A> . Special - considerations which, while not central to Linux FreeS/WAN, are often - tripped over. Includes problems with<A href="background.html#MTU.trouble"> - packet fragmentation</A>, and considerations for testing opportunism.</LI> -<LI>the<A HREF="mail.html#lists"> list archives</A>. Each of the - searchable archives works differently, so it's worth checking each. Use - a search term which is generic, but identifies your error, for example - "No connection is known for". -<BR> Often, you will find that your question has been answered in the - past. Finding an archived answer is quicker than asking the list. You - may, however, find similar questions without answers. If you do, send - their URLs to the list with your trouble report. The additional - examples may help the list tech support person find your answer.</LI> -<LI>Look into the code where the error is being generated. The pluto - code is nicely documented with comments and meaningful variable names.</LI> -</UL> -<P>If you have failed to solve your problem with the help of these - resources, send a detailed problem report to the users list, following - these<A HREF="#prob.report"> guidelines</A>.</P> -<H2><A NAME="use"></A>3. Using a Connection</H2> -<H3><A NAME="8_4_1">3.1 Orienting yourself</A></H3> -<H4><VAR>How do I know if it works?</VAR></H4> -<P>Test your connection by sending packets through it. The simplest way - to do this is with ping, but the ping needs to<STRONG> test the correct - tunnel.</STRONG> See<A HREF="#testgates"> this example scenario</A> if - you don't understand this.</P> -<P></P> -<P>If your ping returns, test any other connections you've brought u all - check out, great. You may wish to<A HREF="#bigpacket"> test with large - packets</A> for MTU problems.</P> -<H4><VAR>ipsec barf</VAR> is useful again</H4> -<P>If your ping fails to return, generate an ipsec barf debugging report - on each IPSec gateway. On a non-Linux FreeS/WAN implementation, gather - equivalent information. Use this, and the tips in the next sections, to - troubleshoot. Are you sure that both endpoints are capable of hearing - and responding to ping?</P> -<H3><A NAME="8_4_2">3.2 Those pesky configuration errors</A></H3> -<P>IPSec may be dropping your ping packets since they do not belong in - the tunnels you have constructed:</P> -<UL> -<LI>Your ping may not test the tunnel you intend to test. For details, - see our<A HREF="faq.html#cantping"> "I can't ping"</A> FAQ.</LI> -<LI> Alternately, you may have a configuration error. For example, you - may have configured one of the four possible tunnels between two - gateways, but not the one required to secure the important traffic - you're now testing. In this case, add and start the tunnel, and try - again.</LI> -</UL> -<P>In either case, you will often see a message like:</P> -<PRE>klipsdebug... no eroute</PRE> -<P>which we discuss in<A HREF="faq.html#no_eroute"> this FAQ</A>.</P> -<P>Note:</P> -<UL> -<LI><A HREF="glossary.html#NAT.gloss">Network Address Translation (NAT)</A> - and<A HREF="glossary.html#masq"> IP masquerade</A> may have an effect - on which tunnels you need to configure.</LI> -<LI>When testing a tunnel that protects a multi-node subnet, try several - subnet nodes as ping targets, in case one node is routing incorrectly.</LI> -</UL> -<H3><A NAME="route.firewall"></A>3.3 Check Routing and Firewalling</H3> -<P>If you've confirmed your configuration assumptions, the problem is - almost certainly with routing or firewalling. Isolate the problem using - interface statistics, firewall statistics, or a packet sniffer.</P> -<H4>Background:</H4> -<UL> -<LI>Linux FreeS/WAN supplies all the special routing it needs; you need - only route packets out through your IPSec gateway. Verify that on the<VAR> - subnetted</VAR> machines you are using for your ping-test, your routing - is as expected. I have seen a tunnel "fail" because the subnet machine - sending packets out an alternate gateway (not our IPSec gateway) on - their return path.</LI> -<LI>Linux FreeS/WAN requires particular<A HREF="firewall.html"> - firewalling considerations</A>. Check the firewall rules on your IPSec - gateways and ensure that they allow IPSec traffic through. Be sure that - no other machine - for example a router between the gateways - is - blocking your IPSec packets.</LI> -</UL> -<H4><A NAME="ifconfig"></A>View Interface and Firewall Statistics</H4> -<P>Interface reports and firewall statistics can help you track down - lost packets at a glance. Check any firewall statistics you may be - keeping on your IPSec gateways, for dropped packets.</P> -<P><STRONG>Tip</STRONG>: You can take a snapshot of the packets - processed by your firewall with:</P> -<PRE> iptables -L -n -v</PRE> -<P>You can get creative with "diff" to find out what happens to a - particular packet during transmission.</P> -<P>Both<VAR> cat /proc/net/dev</VAR> and<VAR> ifconfig</VAR> display - interface statistics, and both are included in<VAR> ipsec barf</VAR>. - Use either to check if any interface has dropped packets. If you find - that one has, test whether this is related to your ping. While you ping - continuously, print that interface's statistics several times. Does its - drop count increase in proportion to the ping? If so, check why the - packets are dropped there.</P> -<P>To do this, look at the firewall rules that apply to that interface. - If the interface is an IPSec interface, more information may be - available in the log. Grep for the word "drop" in a log which was - created with<VAR> klipsdebug=all</VAR> as the error happened.</P> -<P>See also this<A HREF="#ifconfig1"> discussion</A> on interpreting<VAR> - ifconfig</VAR> statistics.</P> -<H3><A NAME="sniff"></A>3.4 When in doubt, sniff it out</H3> -<P>If you have checked configuration assumptions, routing, and firewall - rules, and your interface statistics yield no clue, it remains for you - to investigate the mystery of the lost packet by the most thorough - method: with a packet sniffer (providing, of course, that this is legal - where you are working).</P> -<P>In order to detect packets on the ipsec virtual interfaces, you will - need an up-to-date sniffer (tcpdump, ethereal, ksnuffle) on your IPSec - gateway machines. You may also find it useful to sniff the ping - endpoints.</P> -<H4>Anticipate your packets' path</H4> -<P>Ping, and examine each interface along the projected path, checking - for your ping's arrival. If it doesn't get to the the next stop, you - have narrowed down where to look for it. In this way, you can isolate a - problem area, and narrow your troubleshooting focus.</P> -<P>Within a machine running Linux FreeS/WAN, this<A HREF="firewall.html#packets"> - packet flow diagram</A> will help you anticipate a packet's path.</P> -<P>Note that:</P> -<UL> -<LI> from the perspective of the tunneled packet, the entire tunnel is - one hop. That's explained in<A HREF="faq.html#no_trace"> this</A> FAQ.</LI> -<LI> an encapsulated IPSec packet will look different, when sniffed, - from the plaintext packet which generated it. You can see plaintext - packets entering an IPSec interface and the resulting cyphertext - packets as they emerge from the corresponding physical interface.</LI> -</UL> -<P>Once you isolate where the packet is lost, take a closer look at - firewall rules, routing and configuration assumptions as they affect - that specific area. If the packet is lost on an IPSec gateway, comb - through<VAR> klipsdebug</VAR> output for anomalies.</P> -<P>If the packet goes through both gateways successfully and reaches the - ping target, but does not return, suspect routing. Check that the ping - target routes packets back to the IPSec gateway.</P> -<H3><A NAME="find.use.error"></A>3.5 Check your logs</H3> -<P>Here, too, log information can be useful. Start with the<A HREF="#find.pluto.error"> - guidelines above</A>.</P> -<P>For connection use problems, set<VAR> klipsdebug=all</VAR>. Note that - you must have enabled the<VAR> klipsdebug</VAR><A HREF="install.html#allbut"> - compile-time option</A> to do this. Restart Linux FreeS/WAN so that it - rereads<VAR> ipsec.conf</VAR>, then recreate the error condition. When - searching through<VAR> klipsdebug</VAR> data, look especially for the - keywords "drop" (as in dropped packets) and "error".</P> -<P>Often the problem with connection use is not software error, but - rather that the software is behaving contrary to expectation.</P> -<H4><A NAME="interpret.use.error"></A>Interpreting log text</H4> -<P>To interpret the Linux FreeS/WAN log text you've found, use the same - resources as indicated for troubleshooting connection negotiation:<A HREF="faq.html"> - the FAQ</A> , our<A HREF="background.html"> background document</A>, - and the<A HREF="mail.html#lists"> list archives</A>. Looking in the - KLIPS code is only for the very brave.</P> -<P>If you are still stuck, send a<A HREF="#prob.report"> detailed - problem report</A> to the users' list.</P> -<H3><A NAME="bigpacket"></A>3.6 More testing for the truly thorough</H3> -<H4>Large Packets</H4> -<P>If each of your connections passed the ping test, you may wish to - test by pinging with large packets (2000 bytes or larger). If it does - not return, suspect MTU issues, and see this<A HREF="background.html#MTU.trouble"> - discussion</A>.</P> -<H4>Stress Tests</H4> -<P>In most users' view, a simple ping test, and perhaps a large-packet - ping test suffice to indicate a working IPSec connection.</P> -<P>Some people might like to do additional stress tests prior to - production use. They may be interested in this<A HREF="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/12/msg00224.html"> - testing protocol</A> we use at interoperation conferences, aka - "bakeoffs". We also have a<VAR> testing</VAR> directory that ships with - the release.</P> -<H2><A NAME="prob.report"></A>4. Problem Reporting</H2> -<H3><A NAME="8_5_1">4.1 How to ask for help</A></H3> -<P>Ask for troubleshooting help on the users' mailing list,<A HREF="mailto:users@lists.freeswan.org"> - users@lists.freeswan.org</A>. While sometimes an initial query with a - quick description of your intent and error will twig someone's memory - of a similar problem, it's often necessary to send a second mail with a - complete problem report.</P> -<P>When reporting problems to the mailing list(s), please include:</P> -<UL> -<LI>a brief description of the problem</LI> -<LI>if it's a compile problem, the actual output from make, showing the - problem. Try to edit it down to only the relevant part, but when in - doubt, be as complete as you can. If it's a kernel compile problem, any - relevant out.* files</LI> -<LI>if it's a run-time problem, pointers to where we can find the - complete output from "ipsec barf" from BOTH ENDS (not just one of - them). Remember that it's common outside the US and Canada to pay for - download volume, so if you can't post barfs on the web and send the URL - to the mailing list, at least compress them with tar or gzip. -<BR> If you can, try to simplify the case that is causing the problem. - In particular, if you clear your logs, start FreeS/WAN with no other - connections running, cause the problem to happen, and then do<VAR> - ipsec barf</VAR> on both ends immediately, that gives the smallest and - least cluttered output.</LI> -<LI>any other error messages, complaints, etc. that you saw. Please send - the complete text of the messages, not just a summary.</LI> -<LI>what your network setup is. Include subnets, gateway addresses, etc. - A schematic diagram is a good format for this information.</LI> -<LI>exactly what you were trying to do with Linux FreeS/WAN, and exactly - what went wrong</LI> -<LI>a fix, if you have one. But remember, you are sending mail to people - all over the world; US residents and US citizens in particular, please - read doc/exportlaws.html before sending code -- even small bug fixes -- - to the list or to us.</LI> -<LI>When in doubt about whether to include some seemingly-trivial item - of information, include it. It is rare for problem reports to have too - much information, and common for them to have too little.</LI> -</UL> -<P>Here are some good general guidelines on bug reporting:<A href="http://tuxedo.org/~esr/faqs/smart-questions.html"> - How To Ask Questions The Smart Way</A> and<A href="http://www.chiark.greenend.org.uk/~sgtatham/bugs.html"> - How to Report Bugs Effectively</A>.</P> -<H3><A NAME="8_5_2">4.2 Where to ask</A></H3> -<P>To report a problem, send mail about it to the users' list. If you - are certain that you have found a bug, report it to the bugs list. If - you encounter a problem while doing your own coding on the Linux - FreeS/WAN codebase and think it is of interest to the design team, - notify the design list. When in doubt, default to the users' list. More - information about the mailing lists is found<A HREF="mail.html#lists"> - here</A>.</P> -<P>For a number of reasons -- including export-control regulations - affecting almost any<STRONG> private</STRONG> discussion of encryption - software -- we prefer that problem reports and discussions go to the - lists, not directly to the team. Beware that the list goes worldwide; - US citizens, read this important information about your<A HREF="politics.html#exlaw"> - export laws</A>. If you're using this software, you really should be on - the lists. To get onto them, visit<A HREF="http://lists.freeswan.org/"> - lists.freeswan.org</A>.</P> -<P>If you do send private mail to our coders or want a private reply - from them, please make sure that the return address on your mail (From - or Reply-To header) is a valid one. They have more important things to - do than to unravel addresses that have been mangled in an attempt to - confuse spammers.</P> -<H2><A NAME="notes"></A>5. Additional Notes on Troubleshooting</H2> -<P>The following sections supplement the Guide:<A HREF="#system.info"> - information available on your system</A>;<A HREF="#testgates"> testing - between security gateways</A>;<A HREF="#ifconfig1"> ifconfig reports - for KLIPS debugging</A>;<A HREF="#gdb"> using GDB on Pluto</A>.</P> -<H3><A NAME="system.info"></A>5.1 Information available on your system</H3> -<H4><A NAME="logusage"></A>Logs used</H4> -<P>Linux FreeS/WAN logs to:</P> -<UL> -<LI>/var/log/secure (or, on Debian, /var/log/auth.log)</LI> -<LI>/var/log/messages</LI> -</UL> -<P>Check both places to get full information. If you find nothing, check - your<VAR> syslogd.conf(5)</VAR> to see where your /etc/syslog.conf or - equivalent is directing<VAR> authpriv</VAR> messages.</P> -<H4><A NAME="pages"></A>man pages provided</H4> -<DL> -<DT><A HREF="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</A></DT> -<DD> Manual page for IPSEC configuration file.</DD> -<DT><A HREF="manpage.d/ipsec.8.html"> ipsec(8)</A></DT> -<DD STYLE="margin-bottom: 0.2in"> Primary man page for ipsec utilities.</DD> -</DL> -<P> Other man pages are on<A HREF="manpages.html"> this list</A> and in</P> -<UL> -<LI>/usr/local/man/man3</LI> -<LI>/usr/local/man/man5</LI> -<LI>/usr/local/man/man8/ipsec_*</LI> -</UL> -<H4><A NAME="statusinfo"></A>Status information</H4> -<DL> -<DT>ipsec auto --status</DT> -<DD> Command to get status report from running system. Displays Pluto's - state. Includes the list of connections which are currently "added" to - Pluto's internal database; lists state objects reflecting ISAKMP and - IPsec SAs being negotiated or installed.</DD> -<DT> ipsec look</DT> -<DD> Brief status info.</DD> -<DT> ipsec barf</DT> -<DD STYLE="margin-bottom: 0.2in"> Copious debugging info.</DD> -</DL> -<H3><A NAME="testgates"></A> 5.2 Testing between security gateways</H3> -<P>Sometimes you need to test a subnet-subnet tunnel. This is a tunnel - between two security gateways, which protects traffic on behalf of the - subnets behind these gateways. On this network:</P> -<PRE> Sunset==========West------------------East=========Sunrise - IPSec gateway IPSec gateway - local net untrusted net local net</PRE> -<P> you might name this tunnel sunset-sunrise. You can test this tunnel - by having a machine behind one gateway ping a machine behind the other - gateway, but this is not always convenient or even possible.</P> -<P>Simply pinging one gateway from the other is not useful. Such a ping - does not normally go through the tunnel.<STRONG> The tunnel handles - traffic between the two protected subnets, not between the gateways</STRONG> - . Depending on the routing in place, a ping might</P> -<UL> -<LI>either succeed by finding an unencrypted route</LI> -<LI>or fail by finding no route. Packets without an IPSEC eroute are - discarded.</LI> -</UL> -<P><STRONG>Neither event tells you anything about the tunnel</STRONG>. - You can explicitly create an eroute to force such packets through the - tunnel, or you can create additional tunnels as described in our<A HREF="config.html#multitunnel"> - configuration document</A>, but those may be unnecessary complications - in your situation.</P> -<P>The trick is to explicitly test between<STRONG> both gateways' - private-side IP addresses</STRONG>. Since the private-side interfaces - are on the protected subnets, the resulting packets do go via the - tunnel. Use either ping -I or traceroute -i, both of which allow you to - specify a source interface. (Note: unsupported on older Linuxes). The - same principles apply for a road warrior (or other) case where only one - end of your tunnel is a subnet.</P> -<H3><A NAME="ifconfig1"></A>5.3 ifconfig reports for KLIPS debugging</H3> -<P>When diagnosing problems using ifconfig statistics, you may wonder - what type of activity increments a particular counter for an ipsecN - device. Here's an index, posted by KLIPS developer Richard Guy Briggs:</P> -<PRE>Here is a catalogue of the types of errors that can occur for which -statistics are kept when transmitting and receiving packets via klips. -I notice that they are not necessarily logged in the right counter. -. . . - -Sources of ifconfig statistics for ipsec devices - -rx-errors: -- packet handed to ipsec_rcv that is not an ipsec packet. -- ipsec packet with payload length not modulo 4. -- ipsec packet with bad authenticator length. -- incoming packet with no SA. -- replayed packet. -- incoming authentication failed. -- got esp packet with length not modulo 8. - -tx_dropped: -- cannot process ip_options. -- packet ttl expired. -- packet with no eroute. -- eroute with no SA. -- cannot allocate sk_buff. -- cannot allocate kernel memory. -- sk_buff internal error. - - -The standard counters are: - -struct enet_statistics -{ - int rx_packets; /* total packets received */ - int tx_packets; /* total packets transmitted */ - int rx_errors; /* bad packets received */ - int tx_errors; /* packet transmit problems */ - int rx_dropped; /* no space in linux buffers */ - int tx_dropped; /* no space available in linux */ - int multicast; /* multicast packets received */ - int collisions; - - /* detailed rx_errors: */ - int rx_length_errors; - int rx_over_errors; /* receiver ring buff overflow */ - int rx_crc_errors; /* recved pkt with crc error */ - int rx_frame_errors; /* recv'd frame alignment error */ - int rx_fifo_errors; /* recv'r fifo overrun */ - int rx_missed_errors; /* receiver missed packet */ - - /* detailed tx_errors */ - int tx_aborted_errors; - int tx_carrier_errors; - int tx_fifo_errors; - int tx_heartbeat_errors; - int tx_window_errors; -}; - -of which I think only the first 6 are useful.</PRE> -<H3><A NAME="gdb"></A> 5.4 Using GDB on Pluto</H3> -<P>You may need to use the GNU debugger, gdb(1), on Pluto. This should - be necessary only in unusual cases, for example if you encounter a - problem which the Pluto developer cannot readily reproduce or if you - are modifying Pluto.</P> -<P>Here are the Pluto developer's suggestions for doing this:</P> -<PRE>Can you get a core dump and use gdb to find out what Pluto was doing -when it died? - -To get a core dump, you will have to set dumpdir to point to a -suitable directory (see <A HREF="manpage.d/ipsec.conf.5.html">ipsec.conf(5)</A>). - -To get gdb to tell you interesting stuff: - $ script - $ cd dump-directory-you-chose - $ gdb /usr/local/lib/ipsec/pluto core - (gdb) where - (gdb) quit - $ exit - -The resulting output will have been captured by the script command in -a file called "typescript". Send it to the list. - -Do not delete the core file. I may need to ask you to print out some -more relevant stuff.</PRE> -<P> Note that the<VAR> dumpdir</VAR> parameter takes effect only when - the IPsec subsystem is restarted -- reboot or ipsec setup restart.</P> -<P> -<BR> -<BR></P> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="firewall.html">Previous</A> -<A HREF="compat.html">Next</A> -</BODY> -</HTML> diff --git a/doc/umltesting.html b/doc/umltesting.html deleted file mode 100644 index 35bcef96d..000000000 --- a/doc/umltesting.html +++ /dev/null @@ -1,313 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="roadmap.html">Previous</A> -<A HREF="makecheck.html">Next</A> -<HR> -<H1><A name="umltesting">User-Mode-Linux Testing guide</A></H1> -<P> User mode linux is a way to compile a linux kernel such that it can - run as a process in another linux system (potentially as a *BSD or - Windows process later). See<A HREF="http://user-mode-linux.sourceforge.net/"> - http://user-mode-linux.sourceforge.net/</A></P> -<P> UML is a good platform for testing and experimenting with FreeS/WAN. - It allows several network nodes to be simulated on a single machine. - Creating, configuring, installing, monitoring, and controling these - nodes is generally easier and easier to script with UML than real - hardware.</P> -<P> You'll need about 500Mb of disk space for a full - sunrise-east-west-sunset setup. You can possibly get this down by 130Mb - if you remove the sunrise/sunset kernel build. If you just want to run, - then you can even remove the east/west kernel build.</P> -<P> Nothing need be done as super user. In a couple of steps, we note - where super user is required to install commands in system-wide - directories, but ~/bin could be used instead. UML seems to use a - system-wide /tmp/uml directory so different users may interfere with - one another. Later UMLs use ~/.uml instead, so multiple users running - UML tests should not be a problem, but note that a single user running - the UML tests will only be able run one set. Further, UMLs sometimes - get stuck and hang around. These "zombies" (most will actually be in - the "T" state in the process table) will interfere with subsequent - tests.</P> -<H2><A NAME="34_1">Preliminary Notes on BIND</A></H2> -<P> As of 2003/3/1, the Light-Weight Resolver is used by pluto. This - requires that BIND9 be running. It also requires that BIND9 development - libraries be present in the build environment. The DNSSEC code is only - truly functional in BIND9 snapshots. The library code could be 9.2.2, - we believe. We are using BIND9 20021115 snapshot code from<A HREF="ftp://ftp.isc.org/isc/bind9/snapshots"> - ftp://ftp.isc.org/isc/bind9/snapshots</A>.</P> -<P> FreeS/WAN may well require a newer BIND than is on your system. Many - distributions have moved to BIND9.2.2 recently due to a security - advisory. BIND is five components.</P> -<OL> -<LI> named</LI> -<LI> dnssec-*</LI> -<LI> client side resolver libraries</LI> -<LI> client side utility libraries I thought there were lib and named - parts to dnsssec...</LI> -<LI> dynamic DNS update utilities</LI> -</OL> -<P> The only piece that we need for *building* is #4. That's the only - part that has to be on the build host. What is the difference between - resolver and util libs? If you want to edit - testing/baseconfigs/all/etc/bind, you'll need a snapshot version. The - resolver library contains the resolver. FreeS/WAN has its own copy of - that in lib/liblwres.</P> -<H2><A NAME="34_2">Steps to Install UML for FreeS/WAN</A></H2> -<OL> -<LI> Get the following files: -<OL type="a"> -<LI> from<A HREF="http://www.sandelman.ottawa.on.ca/freeswan/uml/"> - http://www.sandelman.ottawa.on.ca/freeswan/uml/</A> - umlfreeroot-15.1.tar.gz (or highest numbered one). This is a debian - potato root file system. You can use this even on a Redhat host, as it - has the newer GLIBC2.2 libraries as well. -<!-- If you are using - Redhat 7.2 or newer as your development machine, you can create the - image from your installation media. See <A HREF="uml-rhroot.html">Building a RedHat root"></A>. - A future document will explain how to build this from .DEB files as well. ---> - -<!-- -<LI> umlfreesharemini.tar.gz (or umlfreeshareall.tar.gz). - If you are a Debian potato user, you don't need it you can use your - native /usr/share. -</UL> ---> -</LI> -<LI> From<A HREF="ftp://ftp.xs4all.nl/pub/crypto/freeswan/"> - ftp://ftp.xs4all.nl/pub/crypto/freeswan/</A> a snapshot or release - (1.92 or better)</LI> -<LI> From a<A HREF="http://www.kernel.org/mirrors/"> - http://www.kernel.org mirror</A>, the virgin 2.4.19 kernel. Please - realize that we have defaults in our tree for kernel configuration. We - try to track the latest UML kernels. If you use a newer kernel, you may - have faults in the kernel build process. You can see what the latest - that is being regularly tested by visiting<A HREF="http://bugs.freeswan.org:81/regress/HEAD/lastgood/freeswan-regress-env.sh"> - freeswan-regress-env.sh</A>.</LI> -<LI> -<!-- Note: this step is refered to as "step 1d" below. --> - Get<A HREF="http://ftp.nl.linux.org/uml/"> - http://ftp.nl.linux.org/uml/</A> uml-patch-2.4.19-47.bz2 or the one - associated with your kernel. As of 2003/03/05, uml-patch-2.4.19-47.bz2 - works for us.<STRONG> More recent versions of the patch have not been - tested by us.</STRONG></LI> -<LI> You'll probably want to visit<A HREF="http://user-mode-linux.sourceforge.net"> - http://user-mode-linux.sourceforge.net</A> and get the UML utilities. - These are not needed for the build or interactive use (but - recommended). They are necessary for the regression testing procedures - used by "make check". We currently use uml_utilities_20020212.tar.bz2.</LI> -<LI> You need tcpdump version 3.7.1 or better. This is newer than the - version included in most LINUX distributions. You can check the version - of an installed tcpdump with the --version flag. If you need a newer - tcpdump fetch both tcpdump and libpcap source tar files from<A HREF="http://www.tcpdump.org/"> - http://www.tcpdump.org/</A> or a mirror.</LI> -</OL> -</LI> -<LI> Pick a suitable place, and extract the following files: -<OL type="a"> -<LI> -<!-- Note: this step is refered to as "step 2a" later. --> - 2.4.19 kernel. For instance: -<PRE> - <CODE> cd /c2/kernel - tar xzvf ../download/pub/linux/kernel/v2.4/linux-2.4.19.tar.gz -</CODE> -</PRE> -</LI> -<LI> extract the umlfreeroot file -<!-- (unless you <A HREF="uml-rhroot.html">built your own from RPMs</A>) --> - -<PRE> - <CODE> mkdir -p /c2/user-mode-linux/basic-root - cd /c2/user-mode-linux/basic-root - tar xzvf ../download/umlfreeroot-15.1.tar.gz -</CODE> -</PRE> -</LI> -<LI> FreeSWAN itself (or checkout "all" from CVS) -<PRE> - <CODE> mkdir -p /c2/freeswan/sandbox - cd /c2/freeswan/sandbox - tar xzvf ../download/snapshot.tar.gz -</CODE> -</PRE> -</LI> -</OL> -</LI> -<LI> If you need to build a newer tcpdump: -<UL> -<LI> Make sure you have OpenSSL installed -- it is needed for - cryptographic routines.</LI> -<LI> Unpack libpcap and tcpdump source in parallel directories (the - tcpdump build procedures look for libpcap next door).</LI> -<LI> Change directory into the libpcap source directory and then build - the library: -<PRE> - <CODE> ./configure - make -</CODE> -</PRE> -</LI> -<LI> Change into the tcpdump source directory, build tcpdump, and - install it. -<PRE> - <CODE> ./configure - make - # Need to be superuser to install in system directories. - # Installing in ~/bin would be an alternative. - su -c "make install" -</CODE> -</PRE> -</LI> -</UL> -</LI> -<LI> If you need the uml utilities, unpack them somewhere then build and - install them: -<PRE> - <CODE> cd tools - make all - # Need to be superuser to install in system directories. - # Installing in ~/bin would be an alternative. - su -c "make install BIN_DIR=/usr/local/bin" -</CODE> -</PRE> -</LI> -<LI> set up the configuration file -<UL> -<LI> <CODE>cd /c2/freeswan/sandbox/freeswan-1.97/testing/utils</CODE></LI> -<LI> copy umlsetup-sample.sh to ../../umlsetup.sh: <CODE> cp - umlsetup-sample.sh ../../umlsetup.sh</CODE></LI> -<LI> open up ../../umlsetup.sh in your favorite editor.</LI> -<LI> change POOLSPACE= to point to the place with at least 500Mb of - disk. Best if it is on the same partition as the "umlfreeroot" - extraction, as it will attempt to use hard links if possible to save - disk space.</LI> -<LI> Set TESTINGROOT if you intend to run the script outside of the - sandbox/snapshot/release directory. Otherwise, it will configure - itself.</LI> -<LI> KERNPOOL should point to the directory with your 2.4.19 kernel - tree. This tree should be unconfigured! This is the directory you used - in step 2a.</LI> -<LI> UMLPATCH should point at the bz2 file you downloaded at 1d. If - using a kernel that already includes the patch, set this to /dev/null.</LI> -<LI> FREESWANDIR should point at the directory where you unpacked the - snapshot/release. Include the "freeswan-snap2001sep16b" or whatever in - it. If you are running from CVS, then you point at the directory where - top, klips, etc. are. The script will fix up the directory so that it - can be used.</LI> -<LI> BASICROOT should be set to the directory used in 2b, or to the - directory that you created with RPMs.</LI> -<LI> SHAREDIR should be set to the directory used in 2c, to /usr/share - for Debian potato users, or to $BASICROOT/usr/share.</LI> -</UL> -</LI> -<LI> -<PRE> <CODE>cd $TESTINGROOT/utils -sh make-uml.sh -</CODE></PRE> - It will grind for awhile. If there are errors it will bail. If so, run - it under "script" and send the output to bugs@lists.freeswan.org.</LI> -<LI> You will have a bunch of stuff under $POOLSPACE. Open four xterms: -<PRE> <CODE> for i in sunrise sunset east west - do - xterm -name $i -title $i -e $POOLSPACE/$i/start.sh done -</CODE></PRE> -</LI> -<LI> Login as root. Password is "root" (Note, these virtual machines are - networked together, but are not configured to talk to the rest of the - world.)</LI> -<LI> verify that pluto started on east/west, run "ipsec look"</LI> -<LI> login to sunrise. run "ping sunset"</LI> -<LI> login to west. run "tcpdump -p -i eth1 -n" (tcpdump must be version - 3.7.1 or newer)</LI> -<LI> Closing a console xterm will shut down that UML.</LI> -<LI> You can "make check", if you want to. It is run from - /c2/freeswan/sandbox/freeswan-1.97.</LI> -</OL> -<H1><A NAME="35">Debugging the kernel with GDB</A></H1> -<P> With User-Mode-Linux, you can debug the kernel using GDB. See -<!--HREF="http://user-mode-linux.sourceforge.net/debugging.html"--> - - http://user-mode-linux.sourceforge.net/debugging.html.</(null)></P> -<P> Typically, one will want to address a test case for a failing - situation. Running GDB from Emacs, or from other front ends is - possible. First start GDB.</P> -<P> Tell it to open the UMLPOOL/swan/linux program.</P> -<P> Note the PID of GDB:</P> -<PRE> -marajade-[projects/freeswan/mgmt/planning] mcr 1029 %ps ax | grep gdb - 1659 pts/9 SN 0:00 /usr/bin/gdb -fullname -cd /mara4/freeswan/kernpatch/UMLPOOL/swan/ linux -</PRE> -<P> Set the following in the environment:</P> -<PRE> -UML_east_OPT="debug gdb-pid=1659" -</PRE> -<P> Then start the user-mode-linux in the test scheme you wish:</P> -<PRE> -marajade-[kernpatch/testing/klips/east-icmp-02] mcr 1220 %../../utils/runme.sh -</PRE> - The user-mode-linux will stop on boot, giving you a chance to attach to - the process: -<PRE> -(gdb) file linux -Reading symbols from linux...done. -(gdb) attach 1 -Attaching to program: /mara4/freeswan/kernpatch/UMLPOOL/swan/linux, process 1 -0xa0118bc1 in kill () at hostfs_kern.c:770 -</PRE> -<P> At this point, break points should be created as appropriate.</P> -<H2><A NAME="35_1">Other notes about debugging</A></H2> -<P> If you are running a standard test, after all the packets are sent, - the UML will be shutdown. This can cause problems, because the UML may - get terminated while you are debugging.</P> -<P> The environment variable <CODE>NETJIGWAITUSER</CODE> can be set to - "waituser". If so, then the testing system will prompt before exiting - the test.</P> -<H1><A NAME="36">User-Mode-Linux mysteries</A></H1> -<UL> -<LI> running more than one UML of the same name (e.g. "west") can cause - problems.</LI> -<LI> running more than one UML from the same root file system is not a - good idea.</LI> -<LI> all this means that running "make check" twice on the same machine - is probably not a good idea.</LI> -<LI> occationally, UMLs will get stuck. This can happen like: -<!--BLOCK--> - 15134 ? T - 0:00 /spare/hugh/uml/uml2.4.18-sept5/umlbuild/east/linux (east) - [/bin/sh] 15138 ? T 0:00 - /spare/hugh/uml/uml2.4.18-sept5/umlbuild/east/linux (east) [halt]</(null)> - these will need to be killed. Note that they are in "T"racing mode.</LI> -<LI> UMLs can also hang, and will report "Tracing myself and I can't get - out". This is a bug in UML. There are ways to find out what is going on - and report this to the UML people, but we don't know the magic right - now.</LI> -</UL> -<H1><A NAME="37">Getting more info from uml_netjig</A></H1> -<P> uml_netjig can be compiled with a built-in tcpdump. This uses - not-yet-released code from<A HREF="http://www.tcpdump.org/"> - www.tcpdump.org</A>. Please see the instructions in <CODE> -testing/utils/uml_netjig/Makefile</CODE>.</P> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="roadmap.html">Previous</A> -<A HREF="makecheck.html">Next</A> -</BODY> -</HTML> diff --git a/doc/upgrading.html b/doc/upgrading.html deleted file mode 100644 index ce9fba3d2..000000000 --- a/doc/upgrading.html +++ /dev/null @@ -1,184 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="intro.html">Previous</A> -<A HREF="quickstart.html">Next</A> -<HR> -<A NAME="upgrading"></A> -<H1><A NAME="2">Upgrading to FreeS/WAN 2.x</A></H1> -<H2><A NAME="2_1">New! Built in Opportunistic connections</A></H2> -<P>Out of the box, FreeS/WAN 2.x will attempt to encrypt all your IP - traffic. It will try to establish IPsec connections for:</P> -<UL> -<LI> IP traffic from the Linux box on which you have installed - FreeS/WAN, and</LI> -<LI> outbound IP traffic routed through that Linux box (eg. from a - protected subnet).</LI> -</UL> -<P>FreeS/WAN 2.x uses<STRONG> hidden, automatically enabled<VAR> - ipsec.conf</VAR> connections</STRONG> to do this.</P> -<P>This behaviour is part of our campaign to get Opportunistic - Encryption (OE) widespread in the Linux world, so that any two Linux - boxes can encrypt to one another without prearrangement. There's one - catch, however: you must<A HREF="quickstart.html#quickstart"> set up a - few DNS records</A> to distribute RSA public keys and (if applicable) - IPsec gateway information.</P> -<P>If you start FreeS/WAN before you have set up these DNS records, your - connectivity will be slow, and messages relating to the built in - connections will clutter your logs. If you are unable to set up DNS for - OE, you will wish to<A HREF="policygroups.html#disable_policygroups"> - disable the hidden connections</A>.</P> -<A NAME="upgrading.flagday"></A> -<H3><A NAME="2_1_1">Upgrading Opportunistic Encryption to 2.01 (or - later)</A></H3> -<P>As of FreeS/WAN 2.01, Opportunistic Encryption (OE) uses DNS TXT - resource records (RRs) only (rather than TXT with KEY). This change - causes a "flag day". Users of FreeS/WAN 2.00 (or earlier) OE who are - upgrading may need to post additional resource records.</P> -<P>If you are running<A HREF="glossary.html#initiate-only"> - initiate-only OE</A>, you<EM> must</EM> put up a TXT record in any - forward domain as per our<A HREF="quickstart.html#opp.client"> - quickstart instructions</A>. This replaces your old forward KEY.</P> -<P> If you are running full OE, you require no updates. You already have - the needed TXT record in the reverse domain. However, to facilitate - future features, you may also wish to publish that TXT record in a - forward domain as instructed<A HREF="quickstart.html#opp.incoming"> - here</A>.</P> -<P>If you are running OE on a gateway (and encrypting on behalf of - subnetted boxes) you require no updates. You already have the required - TXT record in your gateway's reverse map, and the TXT records for any - subnetted boxes require no updating. However, to facilitate future - features, you may wish to publish your gateway's TXT record in a - forward domain as shown<A HREF="quickstart.html#opp.incoming"> here</A> -.</P> -<P> During the transition, you may wish to leave any old KEY records up - for some time. They will provide limited backward compatibility. -<!-- -For more -detail on that compatibility, see <A HREF="oe.known-issues">Known Issues with -OE</A>. ---> -</P> -<H2><A NAME="2_2">New! Policy Groups</A></H2> -<P>We want to make it easy for you to declare security policy as it - applies to IPsec connections.</P> -<P>Policy Groups make it simple to say:</P> -<UL> -<LI>These are the folks I want to talk to in the clear.</LI> -<LI>These spammers' domains -- I don't want to talk to them at all.</LI> -<LI>To talk to the finance department, I must use IPsec.</LI> -<LI>For any other communication, try to encrypt, but it's okay if we - can't.</LI> -</UL> -<P>FreeS/WAN then implements these policies, creating OE connections if - and when needed. You can use Policy Groups along with connections you - explicitly define in ipsec.conf.</P> -<P>For more information, see our<A HREF="policygroups.html"> Policy - Group HOWTO</A>.</P> -<H2><A NAME="2_3">New! Packetdefault Connection</A></H2> -<P>Free/SWAN 2.x ships with the<STRONG> automatically enabled, hidden - connection</STRONG><VAR> packetdefault</VAR>. This configures a - FreeS/WAN box as an OE gateway for any hosts located behind it. As - mentioned above, you must configure some<A HREF="quickstart.html"> DNS - records</A> for OE to work.</P> -<P>As the name implies, this connection functions as a default. If you - have more specific connections, such as policy groups which configure - your FreeS/WAN box as an OE gateway for a local subnet, these will - apply before<VAR> packetdefault</VAR>. You can view<VAR> packetdefault</VAR> -'s specifics in<A HREF="manpage.d/ipsec.conf.5.html"> man ipsec.conf</A> -.</P> -<H2><A NAME="2_4">FreeS/WAN now disables Reverse Path Filtering</A></H2> -<P>FreeS/WAN often doesn't work with reverse path filtering. At start - time, FreeS/WAN now turns rp_filter off, and logs a warning.</P> -<P>FreeS/WAN does not turn it back on again. You can do this yourself - with a command like:</P> -<PRE> echo 1 > /proc/sys/net/ipv4/conf/eth0/rp_filter</PRE> -<P>For eth0, substitute the interface which FreeS/WAN was affecting.</P> -<A NAME="ipsec.conf_v2"></A> -<H2><A NAME="2_5">Revised<VAR> ipsec.conf</VAR></A></H2> -<H3><A NAME="2_5_1">No promise of compatibility</A></H3> -<P>The FreeS/WAN team promised config-file compatibility throughout the - 1.x series. That means a 1.5 config file can be directly imported into - a fresh 1.99 install with no problems.</P> -<P>With FreeS/WAN 2.x, we've given ourselves permission to make the - config file easier to use. The cost: some FreeS/WAN 1.x configurations - will not work properly. Many of the new features are, however, backward - compatible.</P> -<H3><A NAME="2_5_2">Most<VAR> ipsec.conf</VAR> files will work fine</A></H3> -<P>... so long as you paste this line,<STRONG> with no preceding - whitespace</STRONG>, at the top of your config file:</P> -<PRE> version 2</PRE> -<H3><A NAME="2_5_3">Backward compatibility patch</A></H3> -<P>If the new defaults bite you, use<A HREF="ipsec.conf.2_to_1"> this<VAR> - ipsec.conf</VAR> fragment</A> to simulate the old default values.</P> -<H3><A NAME="2_5_4">Details</A></H3> -<P> We've obsoleted various directives which almost no one was using:</P> -<PRE> dump - plutobackgroundload - no_eroute_pass - lifetime - rekeystart - rekeytries</PRE> -<P>For most of these, there is some other way to elicit the desired - behaviour. See<A HREF="http://lists.freeswan.org/pipermail/design/2002-August/003243.html"> - this post</A>.</P> -<P> We've made some settings, which almost everyone was using, defaults. - For example:</P> -<PRE> interfaces=%defaultroute - plutoload=%search - plutostart=%search - uniqueids=yes</PRE> -<P>We've also changed some default values to help with OE and Policy - Groups:</P> -<PRE> authby=rsasig ## not secret!!! - leftrsasigkey=%dnsondemand ## looks up missing keys in DNS when needed. - rightrsasigkey=%dnsondemand</PRE> -<P> Of course, you can still override any defaults by explictly - declaring something else in your connection.</P> -<P><A HREF="http://lists.freeswan.org/pipermail/design/2002-August/003243.html"> - A post with a list of many ipsec.conf changes.</A> -<BR><A HREF="manpage.d/ipsec.conf.5.html"> Current ipsec.conf manual.</A> -</P> -<A NAME="upgrading.rpms"></A> -<H3><A NAME="2_5_5">Upgrading from 1.x RPMs to 2.x RPMs</A></H3> -<P>Note: When upgrading from 1-series to 2-series RPMs,<VAR> rpm -U</VAR> - will not work.</P> -<P>You must instead erase the 1.x RPMs, then install the 2.x set:</P> -<PRE> rpm -e freeswan</PRE> -<PRE> rpm -e freeswan-module</PRE> -<P>On erasing, your old<VAR> ipsec.conf</VAR> should be moved to<VAR> - ipsec.conf.rpmsave</VAR>. Keep this. You will probably want to copy - your existing connections to the end of your new 2.x file.</P> -<P>Install the RPMs suitable for your kernel version, such as:</P> -<PRE> rpm -ivh freeswan-module-2.04_2.4.20_20.9-0.i386.rpm</PRE> -<PRE> rpm -ivh freeswan-userland-2.04_2.4.20_20.9-0.i386.rpm</PRE> -<P>Or, to splice the files:</P> -<PRE> cat /etc/ipsec.conf /etc/ipsec.conf.rpmsave > /etc/ipsec.conf.tmp - mv /etc/ipsec.conf.tmp /etc/ipsec.conf</PRE> -<P>Then, remove the redundant<VAR> conn %default</VAR> and<VAR> config - setup</VAR> sections. Unless you have done any special configuring - here, you'll likely want to remove the 1.x versions. Remove<VAR> conn - OEself</VAR>, if present.</P> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="intro.html">Previous</A> -<A HREF="quickstart.html">Next</A> -</BODY> -</HTML> diff --git a/doc/user_examples.html b/doc/user_examples.html deleted file mode 100644 index d683c92e1..000000000 --- a/doc/user_examples.html +++ /dev/null @@ -1,320 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="background.html">Previous</A> -<A HREF="makecheck.html">Next</A> -<HR> -<H1><A name="user.examples">FreeS/WAN script examples</A></H1> - This file is intended to hold a collection of user-written example - scripts or configuration files for use with FreeS/WAN. -<P> So far it has only one entry.</P> -<H2><A name="poltorak">Poltorak's Firewall script</A></H2> -<PRE> -From: Poltorak Serguei <poltorak@dataforce.net> -Subject: [Users] Using FreeS/WAN -Date: Tue, 16 Oct 2001 - -Hello. - -I'm using FreeS/WAN IPsec for half a year. I learned a lot of things about -it and I think it would be interesting for someone to see the result of my -experiments and usage of FreeS/WAN. If you find a mistake in this -file, please e-mail me. And excuse me for my english... I'm learning.. :) - -I'll talk about vary simple configuration: - -addresses prefix = 192.168 - - lan1 sgw1 .0.0/24 (Internet) sgw2 lan2 - .1.0/24---[ .1.1 ; .0.1 ]===================[ .0.10 ; . 2.10 ]---.2.0/24 - - -We need to let lan1 see lan2 across Internet like it is behind sgw1. The -same for lan2. And we need to do IPX bridge for Novel Clients and NDS -synchronization. - -my config: -------------------- ipsec.conf ------------------- -conn lan1-lan2 - type=tunnel - compress=yes - #------------------- - left=192.168.0.1 - leftsubnet=192.168.1.0/24 - #------------------- - right=192.168.0.10 - rightsubnet=192.168.2.0/24 - #------------------- - auth=esp - authby=secret ---------------- end of ipsec.conf ---------------- - -ping .2.x from .1.y (y != 1) -It works?? Fine. Let's continue... - -Why y != 1 ?? Because kernel of sgw1 have 2 IP addresses and it will choose -the first IP (which is used to go to Internet) .0.1 and the packet won't go -through IPsec tunnel :( But if do ping on .1.1 kernel will respond from -that address (.1.1) and the packet will be tunneled. The same problem occurred then -.2.x sends a packet to .1.2 which is down at the moment. What happens? .1.1 -sends ARP requesting .1.2... after 3 tries it send to .2.x an destunreach, -but from his "natural" IP or .0.1 . So the error message won't be delivered! -It's a big problem... - -Resolution... One can manipulate with ipsec0 or ipsec0:0 to solve the -problem (if ipsec0 has .1.1 kernel will send packets correctly), but there -are powerful and elegant iproute2 :) We simply need to change source address -of packet that goes to other secure lan. This is done with - -ip route replace 192.168.2.0/24 via 192.168.0.10 dev ipsec0 src 192.168.1.1 - -Cool!! Now it works!! - -The second step. We want install firewall on sgw1 and sgw2. Encryption of -traffic without security isn't a good idea. I don't use {left|right}firewall, -because I'm running firewall from init scripts. - -We want IPsec data between lan1-lan2, some ICMP errors (destination -unreachable, TTL exceeded, parameter problem and source quench), replying on -pings from both lans and Internet, ipxtunnel data for IPX and of course SSH -between sgw1 and sgw2 and from/to one specified host. - -I'm using ipchains. With iptables there are some changes. - ----------------- rc.firewall --------------------- -#!/bin/sh -# -# Firewall for IPsec lan1-lan2 -# - -IPC=/sbin/ipchains -ANY=0.0.0.0/0 - -# left -SGW1_EXT=192.168.0.1 -SGW1_INT=192.168.1.1 -LAN1=192.168.1.0/24 - -# right -SGW2_EXT=192.168.0.10 -SGW2_INT=192.168.2.10 -LAN2=192.168.2.0/24 - -# SSH from and to this host -SSH_PEER_HOST=_SOME_HOST_ - -# this is for left. exchange these values for right. -MY_EXT=$SGW1_EXT -MY_INT=$SGW1_INT -PEER_EXT=$SGW2_EXT -PEER_INT=$SGW2_INT -INT_IF=eth1 -EXT_IF=eth0 -IPSEC_IF=ipsec0 -MY_LAN=$LAN1 -PEER_LAN=$LAN2 - -$IPC -F -$IPC -P input DENY -$IPC -P forward DENY -$IPC -P output DENY - -# Loopback traffic -$IPC -A input -i lo -j ACCEPT -$IPC -A output -i lo -j ACCEPT - -# for IPsec SGW1-SGW2 -## IKE -$IPC -A input -p udp -s $PEER_EXT 500 -d $MY_EXT 500 -i $EXT_IF -j ACCEPT -$IPC -A output -p udp -s $MY_EXT 500 -d $PEER_EXT 500 -i $EXT_IF -j ACCEPT -## ESP -$IPC -A input -p 50 -s $PEER_EXT -d $MY_EXT -i $EXT_IF -j ACCEPT -### we don't need this line ### $IPC -A output -p 50 -s $MY_EXT -d $PEER_EXT -i $EXT_IF -j ACCEPT -## forward LAN1-LAN2 -$IPC -A forward -s $MY_LAN -d $PEER_LAN -i $IPSEC_IF -j ACCEPT -$IPC -A forward -s $PEER_LAN -d $MY_LAN -i $INT_IF -j ACCEPT -$IPC -A output -s $PEER_LAN -d $MY_LAN -i $INT_IF -j ACCEPT -$IPC -A input -s $PEER_LAN -d $MY_LAN -i $IPSEC_IF -j ACCEPT -$IPC -A input -s $MY_LAN -d $PEER_LAN -i $INT_IF -j ACCEPT -$IPC -A output -s $MY_LAN -d $PEER_LAN -i $IPSEC_IF -j ACCEPT - -# ICMP -# -## Dest unreachable -### from/to Internet -$IPC -A input -p icmp --icmp-type destination-unreachable -s $ANY -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type destination-unreachable -s $MY_EXT -d $ANY -i $EXT_IF -j ACCEPT -### from/to Lan -$IPC -A input -p icmp --icmp-type destination-unreachable -s $ANY -d $MY_INT -i $INT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type destination-unreachable -s $MY_INT -d $ANY -i $INT_IF -j ACCEPT -### from/to Peer Lan -$IPC -A input -p icmp --icmp-type destination-unreachable -s $ANY -d $MY_INT -i $IPSEC_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type destination-unreachable -s $MY_INT -d $ANY -i $IPSEC_IF -j ACCEPT -# -## Source quench -### from/to Internet -$IPC -A input -p icmp --icmp-type source-quench -s $ANY -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type source-quench -s $MY_EXT -d $ANY -i $EXT_IF -j ACCEPT -### from/to Lan -$IPC -A input -p icmp --icmp-type source-quench -s $ANY -d $MY_INT -i $INT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type source-quench -s $MY_INT -d $ANY -i $INT_IF -j ACCEPT -### from/to Peer Lan -$IPC -A input -p icmp --icmp-type source-quench -s $ANY -d $MY_INT -i $IPSEC_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type source-quench -s $MY_INT -d $ANY -i $IPSEC_IF -j ACCEPT -# -## Parameter problem -### from/to Internet -$IPC -A input -p icmp --icmp-type parameter-problem -s $ANY -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type parameter-problem -s $MY_EXT -d $ANY -i $EXT_IF -j ACCEPT -### from/to Lan -$IPC -A input -p icmp --icmp-type parameter-problem -s $ANY -d $MY_INT -i $INT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type parameter-problem -s $MY_INT -d $ANY -i $INT_IF -j ACCEPT -### from/to Peer Lan -$IPC -A input -p icmp --icmp-type parameter-problem -s $ANY -d $MY_INT -i $IPSEC_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type parameter-problem -s $MY_INT -d $ANY -i $IPSEC_IF -j ACCEPT -# -## Time To Live exceeded -### from/to Internet -$IPC -A input -p icmp --icmp-type time-exceeded -s $ANY -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type time-exceeded -s $MY_EXT -d $ANY -i $EXT_IF -j ACCEPT -### to Lan -$IPC -A input -p icmp --icmp-type time-exceeded -s $ANY -d $MY_INT -i $INT_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type time-exceeded -s $MY_INT -d $ANY -i $INT_IF -j ACCEPT -### to Peer Lan -$IPC -A input -p icmp --icmp-type time-exceeded -s $ANY -d $MY_INT -i $IPSEC_IF -j ACCEPT -$IPC -A output -p icmp --icmp-type time-exceeded -s $MY_INT -d $ANY -i $IPSEC_IF -j ACCEPT - -# ICMP PINGs -## from Internet -$IPC -A input -p icmp -s $ANY -d $MY_EXT --icmp-type echo-request -i $EXT_IF -j ACCEPT -$IPC -A output -p icmp -s $MY_EXT -d $ANY --icmp-type echo-reply -i $EXT_IF -j ACCEPT -## from LAN -$IPC -A input -p icmp -s $ANY -d $MY_INT --icmp-type echo-request -i $INT_IF -j ACCEPT -$IPC -A output -p icmp -s $MY_INT -d $ANY --icmp-type echo-reply -i $INT_IF -j ACCEPT -## from Peer LAN -$IPC -A input -p icmp -s $ANY -d $MY_INT --icmp-type echo-request -i $IPSEC_IF -j ACCEPT -$IPC -A output -p icmp -s $MY_INT -d $ANY --icmp-type echo-reply -i $IPSEC_IF -j ACCEPT - -# SSH -## from SSH_PEER_HOST -$IPC -A input -p tcp -s $SSH_PEER_HOST -d $MY_EXT 22 -i $EXT_IF -j ACCEPT -$IPC -A output -p tcp \! -y -s $MY_EXT 22 -d $SSH_PEER_HOST -i $EXT_IF -j ACCEPT -## to SSH_PEER_HOST -$IPC -A input -p tcp \! -y -s $SSH_PEER_HOST 22 -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p tcp -s $MY_EXT -d $SSH_PEER_HOST 22 -i $EXT_IF -j ACCEPT -## from PEER -$IPC -A input -p tcp -s $PEER_EXT -d $MY_EXT 22 -i $EXT_IF -j ACCEPT -$IPC -A output -p tcp \! -y -s $MY_EXT 22 -d $PEER_EXT -i $EXT_IF -j ACCEPT -## to PEER -$IPC -A input -p tcp \! -y -s $PEER_EXT 22 -d $MY_EXT -i $EXT_IF -j ACCEPT -$IPC -A output -p tcp -s $MY_EXT -d $PEER_EXT 22 -i $EXT_IF -j ACCEPT - -# ipxtunnel -$IPC -A input -p udp -s $PEER_INT 2005 -d $MY_INT 2005 -i $IPSEC_IF -j ACCEPT -$IPC -A output -p udp -s $MY_INT 2005 -d $PEER_INT 2005 -i $IPSEC_IF -j ACCEPT - ----------------- end of rc.firewall ---------------------- - -To understand this we need to look on this scheme: - - ++-----------------------<----------------------------+ - || ipsec0 | - \/ | - eth0 +--------+ /---------/ yes /---------/ yes +-----------------------+ ------->| INPUT |-->/ ?local? /----->/ ?IPsec? /----->| decrypt decapsulate | - eth1 +--------+ /---------/ /---------/ +-----------------------+ - || no || no - \/ \/ - +----------+ +---------+ +-------+ - | routing | | local | | local | - | decision | | deliver | | send | - +----------+ +---------+ +-------+ - || || - \/ \/ - +---------+ +----------+ - | forward | | routing | - +---------+ | decision | - || +----------+ - || || - ++----------------<-----------------++ - || - \/ - +--------+ eth0 - | OUTPUT | eth1 - +--------+ ipsec0 - || - \/ - /---------/ yes +-----------------------+ - / ?IPsec? /----->| encrypt encapsulate | - /---------/ +-----------------------+ - || no || - || || - || \/ eth0, eth1 - ++-----------------------++--------------> - -This explain how a packet traverse TCP/IP stack in IPsec capable kernel. - -FIX ME, please, if there are any errors - -Test the new firewall now. - - -Now about IPX. I tried 3 programs for tunneling IPX: tipxd, SIB and ipxtunnel - -tipxd didn't send packets.. :( -SIB and ipxtunnel worked fine :) -With ipxtunnel there was a little problem. In sources there are an error. - ---------------------- in main.c ------------------------ -< bytes += p.len; ---- -> bytes += len; --------------------------------------------------------- - -After this FIX everything goes right... - -------------------- /etc/ipxtunnel.conf ---------------- -port 2005 -remote 192.168.101.97 2005 -interface eth1 ---------------- end of /etc/ipxtunnel.conf ------------- - -I use IPX tunnel between .1.1 and .2.10 so we don't need to encrypt nor -authenticate encapsulated IPX packets, it is done with IPsec. - -If you don't wont to use iproute2 to change source IP you need to use SIB -(it is able to bind local address) or establish tunnel between .0.1 and -.0.10 (external IPs, you need to do encryption in the program, but it isn't -strong). - -For now I'm using ipxtunnel. - -I think that's all for the moment. If there are any error, please e-mail me: -poltorak@df.ru . It would be cool if someone puts the scheme of TCP/IP in -kernel and firewall example on FreeS/WAN's manual pages. - -PoltoS -</PRE> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="background.html">Previous</A> -<A HREF="makecheck.html">Next</A> -</BODY> -</HTML> diff --git a/doc/web.html b/doc/web.html deleted file mode 100644 index 0c084d289..000000000 --- a/doc/web.html +++ /dev/null @@ -1,749 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> -<HTML> -<HEAD> -<TITLE>Introduction to FreeS/WAN</TITLE> -<META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=iso-8859-1"> -<STYLE TYPE="text/css"><!-- -BODY { font-family: serif } -H1 { font-family: sans-serif } -H2 { font-family: sans-serif } -H3 { font-family: sans-serif } -H4 { font-family: sans-serif } -H5 { font-family: sans-serif } -H6 { font-family: sans-serif } -SUB { font-size: smaller } -SUP { font-size: smaller } -PRE { font-family: monospace } ---></STYLE> -</HEAD> -<BODY> -<A HREF="toc.html">Contents</A> -<A HREF="mail.html">Previous</A> -<A HREF="glossary.html">Next</A> -<HR> -<H1><A name="weblink">Web links</A></H1> -<H2><A name="freeswan">The Linux FreeS/WAN Project</A></H2> -<P>The main project web site is<A href="http://www.freeswan.org/"> - www.freeswan.org</A>.</P> -<P>Links to other project-related<A href="intro.html#sites"> sites</A> - are provided in our introduction section.</P> -<H3><A name="patch">Add-ons and patches for FreeS/WAN</A></H3> -<P>Some user-contributed patches have been integrated into the FreeS/WAN - distribution. For a variety of reasons, those listed below have not.</P> -<P>Note that not all patches are a good idea.</P> -<UL> -<LI>There are a number of "features" of IPsec which we do not implement - because they reduce security. See this<A href="compat.html#dropped"> - discussion</A>. We do not recommend using patches that implement these. - One example is aggressive mode.</LI> -<LI>We do not recommend adding "features" of any sort unless they are - clearly necessary, or at least have clear benefits. For example, - FreeS/WAN would not become more secure if it offerred a choice of 14 - ciphers. If even one was flawed, it would certainly become less secure - for anyone using that cipher. Even with 14 wonderful ciphers, it would - be harder to maintain and administer, hence more vulnerable to various - human errors.</LI> -</UL> -<P>This is not to say that patches are necessarily bad, only that using - them requires some deliberation. For example, there might be perfectly - good reasons to add a specific cipher in your application: perhaps GOST - to comply with government standards in Eastern Europe, or AES for - performance benefits.</P> -<H4>Current patches</H4> -<P>Patches believed current::</P> -<UL> -<LI>patches for<A href="http://www.strongsec.com/freeswan/"> X.509 - certificate support</A>, also available from a<A href="http://www.twi.ch/~sna/strongsec/freeswan/"> - mirror site</A></LI> -<LI>patches to add<A href="http://www.irrigacion.gov.ar/juanjo/ipsec"> - AES and other ciphers</A>. There is preliminary data indicating AES - gives a substantial<A href="performance.html#perf.more"> performance - gain</A>.</LI> -</UL> -<P>There is also one add-on that takes the form of a modified FreeS/WAN - distribution, rather than just patches to the standard distribution:</P> -<UL> -<LI><A href="http://www.ipv6.iabg.de/downloadframe/index.html">IPv6 - support</A></LI> -</UL> -<P>Before using any of the above,, check the<A href="mail.html"> mailing - lists</A> for news of newer versions and to see whether they have been - incorporated into more recent versions of FreeS/WAN.</P> -<H4>Older patches</H4> -<UL> -<LI><A href="http://sources.colubris.com/en/projects/FreeSWAN/">hardware - acceleration</A></LI> -<LI>a<A href="http://tzukanov.narod.ru/"> series</A> of patches that -<UL> -<LI>provide GOST, a Russian gov't. standard cipher, in MMX assembler</LI> -<LI>add GOST to OpenSSL</LI> -<LI>add GOST to the International kernel patch</LI> -<LI>let FreeS/WAN use International kernel patch ciphers</LI> -</UL> -</LI> -<LI>Neil Dunbar's patches for<A href="ftp://hplose.hpl.hp.com/pub/nd/pluto-openssl.tar.gz"> - certificate support</A>, using code from<A href="http://www.openssl.org"> - Open SSL</A>.</LI> -<LI>Luc Lanthier's<A href="ftp://ftp.netwinder.org/users/f/firesoul/"> - patches</A> for<A href="glossary.html#PKIX"> PKIX</A> support.</LI> -<LI><A href="ftp://ftp.heise.de/pub/ct/listings/9916-180.tgz">patches</A> - to add<A href="glossary.html#blowfish"> Blowfish</A>,<A href="glossary.html#IDEA"> - IDEA</A> and<A href="glossary.html#CAST128"> CAST-128</A> to FreeS/WAN</LI> -<LI>patches for FreeS/WAN 1.3, Pluto support for<A href="http://alcatraz.webcriminals.com/~bastiaan/ipsec/"> - external authentication</A>, for example with a smartcard or SKEYID.</LI> -<LI><A href="http://www.zengl.net/freeswan/download/">patches and - utilities</A> for using FreeS/WAN with PGPnet</LI> -<LI><A href="http://www.freelith.com/lithworks/crypto/freeswan_patch.htm"> -Blowfish encryption and Tiger hash</A></LI> -<LI><A href="http://www.cendio.se/~bellman/aggressive-pluto.snap.tar.gz"> -patches</A> for aggressive mode support</LI> -</UL> -<P>These patches are for older versions of FreeS/WAN and will likely not - work with the current version. Older versions of FreeS/WAN may be - available on some of the<A href="intro.html#sites"> distribution sites</A> -, but we recommend using the current release.</P> -<H4><A name="VPN.masq">VPN masquerade patches</A></H4> -<P>Finally, there are some patches to other code that may be useful with - FreeS/WAN:</P> -<UL> -<LI>a<A href="ftp://ftp.rubyriver.com/pub/jhardin/masquerade/ip_masq_vpn.html"> - patch</A> to make IPsec, PPTP and SSH VPNs work through a Linux - firewall with<A href="glossary.html#masq"> IP masquerade</A>.</LI> -<LI><A href="http://www.linuxdoc.org/HOWTO/VPN-Masquerade-HOWTO.html"> -Linux VPN Masquerade HOWTO</A></LI> -</UL> -<P>Note that this is not required if the same machine does IPsec and - masquerading, only if you want a to locate your IPsec gateway on a - masqueraded network. See our<A href="firewall.html#NAT"> firewalls</A> - document for discussion of why this is problematic.</P> -<P>At last report, this patch could not co-exist with FreeS/WAN on the - same machine.</P> -<H3><A name="dist">Distributions including FreeS/WAN</A></H3> -<P>The introductory section of our document set lists several<A href="intro.html#distwith"> - Linux distributions</A> which include FreeS/WAN.</P> -<H3><A name="used">Things FreeS/WAN uses or could use</A></H3> -<UL> -<LI><A href="http://openpgp.net/random">/dev/random</A> support page, - discussion of and code for the Linux<A href="glossary.html#random"> - random number driver</A>. Out-of-date when we last checked (January - 2000), but still useful.</LI> -<LI>other programs related to random numbers: -<UL> -<LI><A href="http://www.mindrot.org/audio-entropyd.html">audio entropy - daemon</A> to gather noise from a sound card and feed it into - /dev/random</LI> -<LI>an<A href="http://www.lothar.com/tech/crypto/"> entropy-gathering - daemon</A></LI> -<LI>a driver for the random number generator in recent<A href="http://sourceforge.net/projects/gkernel/"> - Intel chipsets</A>. This driver is included as standard in 2.4 kernels.</LI> -</UL> -</LI> -<LI>a Linux<A href="http://www.marko.net/l2tp/"> L2TP Daemon</A> which - might be useful for communicating with Windows 2000 which builds L2TP - tunnels over its IPsec connections</LI> -<LI>to use opportunistic encryption, you need a recent version of<A href="glossary.html#BIND"> - BIND</A>. You can get one from the<A href="http://www.isc.org"> - Internet Software Consortium</A> who maintain BIND.</LI> -</UL> -<H3><A name="alternatives">Other approaches to VPNs for Linux</A></H3> -<UL> -<LI>other Linux<A href="#linuxipsec"> IPsec implementations</A></LI> -<LI><A href="http://www.tik.ee.ethz.ch/~skip/">ENskip</A>, a free - implementation of Sun's<A href="glossary.html#SKIP"> SKIP</A> protocol</LI> -<LI><A href="http://sunsite.auc.dk/vpnd/">vpnd</A>, a non-IPsec VPN - daemon for Linux which creates tunnels using<A href="glossary.html#Blowfish"> - Blowfish</A> encryption</LI> -<LI><A href="http://www.winton.org.uk/zebedee/">Zebedee</A>, a simple - GPLd tunnel-building program with Linux and Win32 versions. The name is - from<STRONG> Z</STRONG>lib compression,<STRONG> B</STRONG>lowfish - encryption and<STRONG> D</STRONG>iffie-Hellman key exchange.</LI> -<LI>There are at least two PPTP implementations for Linux -<UL> -<LI>Moreton Bay's<A href="http://www.moretonbay.com/vpn/pptp.html"> - PoPToP</A></LI> -<LI><A href="http://cag.lcs.mit.edu/~cananian/Projects/PPTP/">PPTP-Linux</A> -</LI> -</UL> -</LI> -<LI><A href="http://sites.inka.de/sites/bigred/devel/cipe.html">CIPE</A> - (crypto IP encapsulation) project, using their own lightweight protocol - to encrypt between routers</LI> -<LI><A href="http://tinc.nl.linux.org/">tinc</A>, a VPN Daemon</LI> -</UL> -<P>There is a list of<A href="http://www.securityportal.com/lskb/10000000/kben10000005.html"> - Linux VPN</A> software in the<A href="http://www.securityportal.com/lskb/kben00000001.html"> - Linux Security Knowledge Base</A>.</P> -<H2><A name="ipsec.link">The IPsec Protocols</A></H2> -<H3><A name="general">General IPsec or VPN information</A></H3> -<UL> -<LI>The<A href="http://www.vpnc.org"> VPN Consortium</A> is a group for - vendors of IPsec products. Among other things, they have a good - collection of<A href="http://www.vpnc.org/white-papers.html"> IPsec - white papers</A>.</LI> -<LI>A VPN mailing list with a<A href="http://kubarb.phsx.ukans.edu/~tbird/vpn.html"> - home page</A>, a FAQ, some product comparisons, and many links.</LI> -<LI><A href="http://www.opus1.com/vpn/index.html">VPN pointer page</A></LI> -<LI>a<A href="http://www.epm.ornl.gov/~dunigan/vpn.html"> collection</A> - of VPN links, and some explanation</LI> -</UL> -<H3><A name="overview">IPsec overview documents or slide sets</A></H3> -<UL> -<LI>the FreeS/WAN<A href="ipsec.html"> document section</A> on these - protocols</LI> -</UL> -<H3><A name="otherlang">IPsec information in languages other than - English</A></H3> -<UL> -<LI><A href="http://www.imib.med.tu-dresden.de/imib/Internet/Literatur/ipsec-docu.html"> -German</A></LI> -<LI><A href="http://www.kame.net/index-j.html">Japanese</A></LI> -<LI>Feczak Szabolcs' thesis in<A href="http://feczo.koli.kando.hu/vpn/"> - Hungarian</A></LI> -<LI>Davide Cerri's thesis and some presentation slides<A href="http://www.linux.it/~davide/doc/"> - Italian</A></LI> -</UL> -<H3><A name="RFCs1">RFCs and other reference documents</A></H3> -<UL> -<LI><A href="rfc.html">Our document</A> listing the RFCs relevant to - Linux FreeS/WAN and giving various ways of obtaining both RFCs and - Internet Drafts.</LI> -<LI><A href="http://www.vpnc.org/vpn-standards.html">VPN Standards</A> - page maintained by<A href="glossary.html#VPNC"> VPNC</A>. This covers - both RFCs and Drafts, and classifies them in a fairly helpful way.</LI> -<LI><A href="http://www.rfc-editor.org">RFC archive</A></LI> -<LI><A href="http://www.ietf.org/ids.by.wg/ipsec.html">Internet Drafts</A> - related to IPsec</LI> -<LI>US government<A href="http://www.itl.nist.gov/div897/pubs"> site</A> - with their<A href="glossary.html#FIPS"> FIPS</A> standards</LI> -<LI>Archives of the ipsec@tis.com mailing list where discussion of - drafts takes place. -<UL> -<LI><A href="http://www.sandelman.ottawa.on.ca/ipsec">Eastern Canada</A></LI> -<LI><A href="http://www.vpnc.org/ietf-ipsec">California</A>.</LI> -</UL> -</LI> -</UL> -<H3><A name="analysis">Analysis and critiques of IPsec protocols</A></H3> -<UL> -<LI>Counterpane's<A href="http://www.counterpane.com/ipsec.pdf"> - evaluation</A> of the protocols</LI> -<LI>Simpson's<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/1999/06/msg00319.html"> - IKE Considered Dangerous</A> paper. Note that this is a link to an - archive of our mailing list. There are several replies in addition to - the paper itself.</LI> -<LI>Fate Labs<A href="http://www.fatelabs.com/loki-vpn.pdf"> Virual - Private Problems: the Broken Dream</A></LI> -<LI>Catherine Meadows' paper<CITE> Analysis of the Internet Key Exchange - Protocol Using the NRL Protocol Analyzer</CITE>, in<A href="http://chacs.nrl.navy.mil/publications/CHACS/1999/1999meadows-IEEE99.pdf"> - PDF</A> or<A href="http://chacs.nrl.navy.mil/publications/CHACS/1999/1999meadows-IEEE99.ps"> - Postscript</A>.</LI> -<LI>Perlman and Kaufmnan -<UL> -<LI><A href="http://snoopy.seas.smu.edu/ee8392_summer01/week7/perlman2.pdf"> -Key Exchange in IPsec</A></LI> -<LI>a newer<A href="http://sec.femto.org/wetice-2001/papers/radia-paper.pdf"> - PDF paper</A>,<CITE> Analysis of the IPsec Key Exchange Standard</CITE> -.</LI> -</UL> -</LI> -<LI>Bellovin's<A href="http://www.research.att.com/~smb/papers/index.html"> - papers</A> page including his: -<UL> -<LI><CITE>Security Problems in the TCP/IP Protocol Suite</CITE> (1989)</LI> -<LI><CITE>Problem Areas for the IP Security Protocols</CITE> (1996)</LI> -<LI><CITE>Probable Plaintext Cryptanalysis of the IP Security Protocols</CITE> - (1997)</LI> -</UL> -</LI> -<LI>An<A href="http://www.lounge.org/ike_doi_errata.html"> errata list</A> - for the IPsec RFCs.</LI> -</UL> -<H3><A name="IP.background">Background information on IP</A></H3> -<UL> -<LI>An<A href="http://ipprimer.windsorcs.com/"> IP tutorial</A> that - seems to be written mainly for Netware or Microsoft LAN admins entering - a new world</LI> -<LI><A href="http://www.iana.org">IANA</A>, Internet Assigned Numbers - Authority</LI> -<LI><A href="http://public.pacbell.net/dedicated/cidr.html">CIDR</A>, - Classless Inter-Domain Routing</LI> -<LI>Also see our<A href="biblio.html"> bibliography</A></LI> -</UL> -<H2><A name="implement">IPsec Implementations</A></H2> -<H3><A name="linuxprod">Linux products</A></H3> -<P>Vendors using FreeS/WAN in turnkey firewall or VPN products are - listed in our<A href="intro.html#turnkey"> introduction</A>.</P> -<P>Other vendors have Linux IPsec products which, as far as we know, do - not use FreeS/WAN</P> -<UL> -<LI><A href="http://www.redcreek.com/products/shareware.html">Redcreek</A> - provide an open source Linux driver for their PCI hardware VPN card. - This card has a 100 Mbit Ethernet port, an Intel 960 CPU plus more - specialised crypto chips, and claimed encryption performance of 45 - Mbit/sec. The PC sees it as an Ethernet board.</LI> -<LI><A href="http://linuxtoday.com/stories/8428.html?nn">Paktronix</A> - offer a Linux-based VPN with hardware encryption</LI> -<LI><A href="http://www.watchguard.com/">Watchguard</A> use Linux in - their Firebox product.</LI> -<LI><A href="http://www.entrust.com">Entrust</A> offer a developers' - toolkit for using their<A href="glossary.html#PKI"> PKI</A> for IPsec - authentication</LI> -<LI>According to a report on our mailing list,<A href="http://www.axent.com"> - Axent</A> have a Linux version of their product.</LI> -</UL> -<H3><A name="router">IPsec in router products</A></H3> -<P>All the major router vendors support IPsec, at least in some models.</P> -<UL> -<LI><A href="http://www.cisco.com/warp/public/707/16.html">Cisco</A> - IPsec information</LI> -<LI>Ascend, now part of<A href="http://www.lucent.com/"> Lucent</A>, - have some IPsec-based products</LI> -<LI><A href="http://www.nortelnetworks.com/">Bay Networks</A>, now part - of Nortel, use IPsec in their Contivity switch product line</LI> -<LI><A href="http://www.3com.com/products/enterprise.html">3Com</A> have - a number of VPN products, some using IPsec</LI> -</UL> -<H3><A name="fw.web">IPsec in firewall products</A></H3> -<P>Many firewall vendors offer IPsec, either as a standard part of their - product, or an optional extra. A few we know about are:</P> -<UL> -<LI><A href="http://www.borderware.com/">Borderware</A></LI> -<LI><A href="http://www.ashleylaurent.com/vpn/ipsec_vpn.htm">Ashley - Laurent</A></LI> -<LI><A href="http://www.watchguard.com">Watchguard</A></LI> -<LI><A href="http://www.fx.dk/firewall/ipsec.html">Injoy</A> for OS/2</LI> -</UL> -<P>Vendors using FreeS/WAN in turnkey firewall products are listed in - our<A href="intro.html#turnkey"> introduction</A>.</P> -<H3><A name="ipsecos">Operating systems with IPsec support</A></H3> -<P>All the major open source operating systems support IPsec. See below - for details on<A href="#BSD"> BSD-derived</A> Unix variants.</P> -<P>Among commercial OS vendors, IPsec players include:</P> -<UL> -<LI><A href="http://msdn.microsoft.com/isapi/msdnlib.idc?theURL=/library/backgrnd/html/msdn_ip_security.htm"> -Microsoft</A> have put IPsec in their Windows 2000 and XP products</LI> -<LI><A href="http://www.s390.ibm.com/stories/1999/os390v2r8_pr.html">IBM</A> - announce a release of OS390 with IPsec support via a crypto - co-processor</LI> -<LI><A href="http://www.sun.com/solaris/ds/ds-security/ds-security.pdf"> -Sun</A> include IPsec in Solaris 8</LI> -<LI><A href="http://www.hp.com/security/products/extranet-security.html"> -Hewlett Packard</A> offer IPsec for their Unix machines</LI> -<LI>Certicom have IPsec available for the<A href="http://www.certicom.com/products/movian/movianvpn_tech.html"> - Palm</A>.</LI> -<LI>There were reports before the release that Apple's Mac OS X would - have IPsec support built in, but it did not seem to be there when we - last checked. If you find, it please let us know via the<A href="mail.html"> - mailing list</A>.</LI> -</UL> -<H3><A NAME="29_3_5">IPsec on network cards</A></H3> -<P>Network cards with built-in IPsec acceleration are available from at - least Intel, 3Com and Redcreek.</P> -<H3><A name="opensource">Open source IPsec implementations</A></H3> -<H4><A name="linuxipsec">Other Linux IPsec implementations</A></H4> -<P>We like to think of FreeS/WAN as<EM> the</EM> Linux IPsec - implementation, but it is not the only one. Others we know of are:</P> -<UL> -<LI><A href="http://www.enst.fr/~beyssac/pipsec/">pipsecd</A>, a - lightweight implementation of IPsec for Linux. Does not require kernel - recompilation.</LI> -<LI>Petr Novak's<A href="ftp://ftp.eunet.cz/icz/ipnsec/"> ipnsec</A>, - based on the OpenBSD IPsec code and using<A href="glossary.html#photuris"> - Photuris</A> for key management</LI> -<LI>A now defunct project at<A href="http://www.cs.arizona.edu/security/hpcc-blue/linux.html"> - U of Arizona</A> (export controlled)</LI> -<LI><A href="http://snad.ncsl.nist.gov/cerberus">NIST Cerebus</A> - (export controlled)</LI> -</UL> -<H4><A name="BSD">IPsec for BSD Unix</A></H4> -<UL> -<LI><A href="http://www.kame.net/project-overview.html">KAME</A>, - several large Japanese companies co-operating on IPv6 and IPsec</LI> -<LI><A href="http://web.mit.edu/network/isakmp">US Naval Research Lab</A> - implementation of IPv6 and of IPsec for IPv4 (export controlled)</LI> -<LI><A href="http://www.openbsd.org">OpenBSD</A> includes IPsec as a - standard part of the distribution</LI> -<LI><A href="http://www.r4k.net/ipsec">IPsec for FreeBSD</A></LI> -<LI>a<A href="http://www.netbsd.org/Documentation/network/ipsec/"> FAQ</A> - on NetBSD's IPsec implementation</LI> -</UL> -<H4><A name="misc">IPsec for other systems</A></H4> -<UL> -<LI><A href="http://www.tcm.hut.fi/Tutkimus/IPSEC/">Helsinki U of - Technolgy</A> have implemented IPsec for Solaris, Java and Macintosh</LI> -</UL> -<H3><A name="interop.web">Interoperability</A></H3> -<P>The IPsec protocols are designed so that different implementations - should be able to work together. As they say "the devil is in the - details". IPsec has a lot of details, but considerable success has been - achieved.</P> -<H4><A name="result">Interoperability results</A></H4> -<P>Linux FreeS/WAN has been tested for interoperability with many other - IPsec implementations. Results to date are in our<A href="interop.html"> - interoperability</A> section.</P> -<P>Various other sites have information on interoperability between - various IPsec implementations:</P> -<UL> -<LI><A href="http://www.opus1.com/vpn/atl99display.html">interop results</A> - from a bakeoff in Atlanta, September 1999.</LI> -<LI>a French company, HSC's,<A href="http://www.hsc.fr/ressources/presentations/ipsec99/index.html.en"> - interoperability</A> test data covers FreeS/WAN, Open BSD, KAME, Linux - pipsecd, Checkpoint, Red Creek Ravlin, and Cisco IOS</LI> -<LI><A href="http://www.icsa.net/">ICSA</A> offer certification programs - for various security-related products. See their list of<A href="http://www.icsa.net/html/communities/ipsec/certification/certified_products/index.shtml"> - certified IPsec</A> products. Linux FreeS/WAN is not currently on that - list, but several products with which we interoperate are.</LI> -<LI>VPNC have a page on why they are not yet doing<A href="http://www.vpnc.org/interop.html"> - interoperability</A> testing and a page on the<A href="http://www.vpnc.org/conformance.html"> - spec conformance</A> testing that they are doing</LI> -<LI>a<A href="http://www.commweb.com/article/COM20000912S0009"> review</A> - comparing a dozen commercial IPsec implemetations. Unfortunately, the - reviewers did not look at Open Source implementations such as FreeS/WAN - or OpenBSD.</LI> -<LI><A href="http://www.tanu.org/~sakane/doc/public/report-ike-interop0007.html"> -results</A> from interoperability tests at a conference. FreeS/WAN was - not tested there.</LI> -<LI>test results from the<A href="http://www.hsc.fr/ressources/veille/ipsec/ipsec2000/"> - IPSEC 2000</A> conference</LI> -</UL> -<H4><A name="test1">Interoperability test sites</A></H4> -<UL> -<LI><A href="http://www.tahi.org/">TAHI</A>, a Japanese IPv6 testing - project with free IPsec validation software</LI> -<LI><A href="http://ipsec-wit.antd.nist.gov">National Institute of - Standards and Technology</A></LI> -<LI><A href="http://isakmp-test.ssh.fi/">SSH Communications Security</A></LI> -</UL> -<H2><A name="linux.link">Linux links</A></H2> -<H3><A name="linux.basic">Basic and tutorial Linux information</A></H3> -<UL> -<LI>Linux<A href="http://linuxcentral.com/linux/LDP/LDP/gs/gs.html"> - Getting Started</A> HOWTO document</LI> -<LI>A getting started guide from the<A href="http://darkwing.uoregon.edu/~cchome/linuxgettingstarted.html"> - U of Oregon</A></LI> -<LI>A large<A href="http://www.herring.org/techie.html"> link collection</A> - which includes a lot of introductory and tutorial material on Unix, - Linux, the net, . . .</LI> -</UL> -<H3><A name="general">General Linux sites</A></H3> -<UL> -<LI><A href="http://www.freshmeat.net">Freshmeat</A> Linux news</LI> -<LI><A href="http://slashdot.org">Slashdot</A> "News for Nerds"</LI> -<LI><A href="http://www.linux.org">Linux Online</A></LI> -<LI><A href="http://www.linuxhq.com">Linux HQ</A></LI> -<LI><A href="http://www.tux.org">tux.org</A></LI> -</UL> -<H3><A name="docs.ldp">Documentation</A></H3> -<P>Nearly any Linux documentation you are likely to want can be found at - the<A href="http://metalab.unc.edu/LDP"> Linux Documentation Project</A> - or LDP.</P> -<UL> -<LI><A href="http://metalab.unc.edu/LDP/HOWTO/META-FAQ.html">Meta-FAQ</A> - guide to Linux information sources</LI> -<LI>The LDP's HowTo documents are a standard Linux reference. See this<A href="http://www.linuxdoc.org/docs.html#howto"> - list</A>. Documents there most relevant to a FreeS/WAN gateway are: -<UL> -<LI><A href="http://metalab.unc.edu/LDP/HOWTO/Kernel-HOWTO.html">Kernel - HOWTO</A></LI> -<LI><A href="http://metalab.unc.edu/LDP/HOWTO/Networking-Overview-HOWTO.html"> -Networking Overview HOWTO</A></LI> -<LI><A href="http://metalab.unc.edu/LDP/HOWTO/Security-HOWTO.html"> -Security HOWTO</A></LI> -</UL> -</LI> -<LI>The LDP do a series of Guides, book-sized publications with more - detail (and often more "why do it this way?") than the HowTos. See this<A -href="http://www.linuxdoc.org/guides.html"> list</A>. Documents there - most relevant to a FreeS/WAN gateway are: -<UL> -<LI><A href="http://www.tml.hut.fi/~viu/linux/sag/">System - Administrator's Guide</A></LI> -<LI><A href="http://www.linuxdoc.org/LDP/nag2/index.html">Network - Adminstrator's Guide</A></LI> -<LI><A href="http://www.seifried.org/lasg/">Linux Administrator's - Security Guide</A></LI> -</UL> -</LI> -</UL> -<P>You may not need to go to the LDP to get this material. Most Linux - distributions include the HowTos on their CDs and several include the - Guides as well. Also, most of the Guides and some collections of HowTos - are available in book form from various publishers.</P> -<P>Much of the LDP material is also available in languages other than - English. See this<A href="http://www.linuxdoc.org/links/nenglish.html"> - LDP page</A>.</P> -<H3><A name="advroute.web">Advanced routing</A></H3> -<P>The Linux IP stack has some new features in 2.4 kernels. Some HowTos - have been written:</P> -<UL> -<LI>several HowTos for the<A href="http://netfilter.samba.org/unreliable-guides/"> - netfilter</A> firewall code in newer kernels</LI> -<LI><A href="http://www.ds9a.nl/2.4Networking/HOWTO//cvs/2.4routing/output/2.4networking.html"> -2.4 networking</A> HowTo</LI> -<LI><A href="http://www.ds9a.nl/2.4Networking/HOWTO//cvs/2.4routing/output/2.4routing.html"> -2.4 routing</A> HowTo</LI> -</UL> -<H3><A name="linsec">Security for Linux</A></H3> -<P>See also the<A href="#docs.ldp"> LDP material</A> above.</P> -<UL> -<LI><A href="http://www.ecst.csuchico.edu/~dranch/LINUX/index-linux.html#trinityos"> -Trinity OS guide to setting up Linux</A></LI> -<LI><A href="http://www.deter.com/unix">Unix security</A> page</LI> -<LI><A href="http://linux01.gwdg.de/~alatham/">PPDD</A> encrypting - filesystem</LI> -<LI><A href="http://EncryptionHOWTO.sourceforge.net/">Linux Encryption - HowTo</A> (outdated when last checked, had an Oct 2000 revision date in - March 2002)</LI> -</UL> -<H3><A name="firewall.linux">Linux firewalls</A></H3> -<P>Our<A href="firewall.html"> FreeS/WAN and firewalls</A> document - includes links to several sets of<A href="firewall.html#examplefw"> - scripts</A> known to work with FreeS/WAN.</P> -<P>Other information sources:</P> -<UL> -<LI><A href="http://ipmasq.cjb.net/">IP Masquerade resource page</A></LI> -<LI><A href="http://netfilter.samba.org/unreliable-guides/">netfilter</A> - firewall code in 2.4 kernels</LI> -<LI>Our list of general<A href="#firewall.web"> firewall references</A> - on the web</LI> -<LI><A href="http://users.dhp.com/~whisper/mason/">Mason</A>, a tool for - automatically configuring Linux firewalls</LI> -<LI>the web cache software<A href="http://www.squid-cache.org/"> squid</A> - and<A href="http://www.squidguard.org/"> squidguard</A> which turns - Squid into a filtering web proxy</LI> -</UL> -<H3><A name="linux.misc">Miscellaneous Linux information</A></H3> -<UL> -<LI><A href="http://lwn.net/current/dists.php3">Linux distribution - vendors</A></LI> -<LI><A href="http://www.linux.org/groups/">Linux User Groups</A></LI> -</UL> -<H2><A name="crypto.link">Crypto and security links</A></H2> -<H3><A name="security">Crypto and security resources</A></H3> -<H4><A name="std.links">The standard link collections</A></H4> -<P>Two enormous collections of links, each the standard reference in its - area:</P> -<DL> -<DT>Gene Spafford's<A href="http://www.cerias.purdue.edu/coast/hotlist/"> - COAST hotlist</A></DT> -<DD>Computer and network security.</DD> -<DT>Peter Gutmann's<A href="http://www.cs.auckland.ac.nz/~pgut001/links.html"> - Encryption and Security-related Resources</A></DT> -<DD>Cryptography.</DD> -</DL> -<H4><A name="FAQ">Frequently Asked Question (FAQ) documents</A></H4> -<UL> -<LI><A href="http://www.faqs.org/faqs/cryptography-faq/">Cryptography - FAQ</A></LI> -<LI><A href="http://www.interhack.net/pubs/fwfaq">Firewall FAQ</A></LI> -<LI><A href="http://www.whitefang.com/sup/secure-faq.html">Secure Unix - Programming FAQ</A></LI> -<LI>FAQs for specific programs are listed in the<A href="#tools"> tools</A> - section below.</LI> -</UL> -<H4><A name="cryptover">Tutorials</A></H4> -<UL> -<LI>Gary Kessler's<A href="http://www.garykessler.net/library/crypto.html"> - Overview of Cryptography</A></LI> -<LI>Terry Ritter's<A href="http://www.ciphersbyritter.com/LEARNING.HTM"> - introduction</A></LI> -<LI>Peter Gutman's<A href="http://www.cs.auckland.ac.nz/~pgut001/tutorial/index.html"> - cryptography</A> tutorial (500 slides in PDF format)</LI> -<LI>Amir Herzberg of IBM's sildes for his course<A href="http://www.hrl.il.ibm.com/mpay/course.html"> - Introduction to Cryptography and Electronic Commerce</A></LI> -<LI>the<A href="http://www.gnupg.org/gph/en/manual/c173.html"> concepts - section</A> of the<A href="glossary.html#GPG"> GNU Privacy Guard</A> - documentation</LI> -<LI>Bruce Schneier's self-study<A href="http://www.counterpane.com/self-study.html"> - cryptanalysis</A> course</LI> -</UL> -<P>See also the<A href="#interesting"> interesting papers</A> section - below.</P> -<H4><A name="standards">Crypto and security standards</A></H4> -<UL> -<LI><A href="http://csrc.nist.gov/cc">Common Criteria</A>, new - international computer and network security standards to replace the - "Rainbow" series</LI> -<LI>AES<A href="http://csrc.nist.gov/encryption/aes/aes_home.htm"> - Advanced Encryption Standard</A> which will replace DES</LI> -<LI><A href="http://grouper.ieee.org/groups/1363">IEEE P-1363 public key - standard</A></LI> -<LI>our collection of links for the<A href="#ipsec.link"> IPsec</A> - standards</LI> -<LI>history of<A href="http://www.visi.com/crypto/evalhist/index.html"> - formal evaluation</A> of security policies and implementation</LI> -</UL> -<H4><A name="quotes">Crypto quotes</A></H4> -<P>There are several collections of cryptographic quotes on the net:</P> -<UL> -<LI><A href="http://www.eff.org/pub/EFF/quotes.eff">the EFF</A></LI> -<LI><A href="http://www.samsimpson.com/cquotes.php">Sam Simpson</A></LI> -<LI><A href="http://www.amk.ca/quotations/cryptography/page-1.html">AM - Kutchling</A></LI> -</UL> -<H3><A name="policy">Cryptography law and policy</A></H3> -<H4><A name="legal">Surveys of crypto law</A></H4> -<UL> -<LI>International survey of<A href="http://cwis.kub.nl/~FRW/PEOPLE/koops/lawsurvy.htm"> - crypto law</A>.</LI> -<LI>International survey of<A href="http://rechten.kub.nl/simone/ds-lawsu.htm"> - digital signature law</A></LI> -</UL> -<H4><A name="oppose">Organisations opposing crypto restrictions</A></H4> -<UL> -<LI>The<A href="glossary.html#EFF"> EFF</A>'s archives on<A href="http://www.eff.org/pub/Privacy/"> - privacy</A> and<A href="http://www.eff.org/pub/Privacy/ITAR_export/"> - export control</A>.</LI> -<LI><A href="http://www.gilc.org">Global Internet Liberty Campaign</A></LI> -<LI><A href="http://www.cdt.org/crypto">Center for Democracy and - Technology</A></LI> -<LI><A href="http://www.privacyinternational.org/">Privacy International</A> -, who give out<A href="http://www.bigbrotherawards.org/"> Big Brother - Awards</A> to snoopy organisations</LI> -</UL> -<H4><A name="other.policy">Other information on crypto policy</A></H4> -<UL> -<LI><A href="ftp://ftp.isi.edu/in-notes/rfc1984.txt">RFC 1984</A>, the<A href="glossary.html#IAB"> - IAB</A> and<A href="glossary.html#IESG"> IESG</A> Statement on - Cryptographic Technology and the Internet.</LI> -<LI>John Young's collection of<A href="http://cryptome.org/"> documents</A> - of interest to the cryptography, open government and privacy movements, - organized chronologically</LI> -<LI>AT&T researcher Matt Blaze's Encryption, Privacy and Security<A href="http://www.crypto.com"> - Resource Page</A></LI> -<LI>A good<A href="http://cryptome.org/crypto97-ne.htm"> overview</A> of - the issues from Australia.</LI> -</UL> -<P>See also our documentation section on the<A href="politics.html"> - history and politics</A> of cryptography.</P> -<H3><A name="crypto.tech">Cryptography technical information</A></H3> -<H4><A name="cryptolinks">Collections of crypto links</A></H4> -<UL> -<LI><A href="http://www.counterpane.com/hotlist.html">Counterpane</A></LI> -<LI><A href="http://www.cs.auckland.ac.nz/~pgut001/links.html">Peter - Gutman's links</A></LI> -<LI><A href="http://www.pca.dfn.de/eng/team/ske/pem-dok.html">PKI links</A> -</LI> -<LI><A href="http://crypto.yashy.com/www/">Robert Guerra's links</A></LI> -</UL> -<H4><A name="papers">Lists of online cryptography papers</A></H4> -<UL> -<LI><A href="http://www.counterpane.com/biblio">Counterpane</A></LI> -<LI><A href="http://www.cryptography.com/resources/papers"> -cryptography.com</A></LI> -<LI><A href="http://www.cryptosoft.com/html/secpub.htm">Cryptosoft</A></LI> -</UL> -<H4><A name="interesting">Particularly interesting papers</A></H4> -<P>These papers emphasize important issues around the use of - cryptography, and the design and management of secure systems.</P> -<UL> -<LI><A href="http://www.counterpane.com/keylength.html">Key length - requirements for security</A></LI> -<LI><A href="http://www.cl.cam.ac.uk/users/rja14/wcf.html">Why - Cryptosystems Fail</A></LI> -<LI><A href="http://www.cdt.org/crypto/risks98/">Risks of escrowed - encryption</A></LI> -<LI><A href="http://www.counterpane.com/pitfalls.html">Security pitfalls - in cryptography</A></LI> -<LI><A href="http://www.acm.org/classics/sep95">Reflections on Trusting - Trust</A>, Ken Thompson on Trojan horse design</LI> -<LI><A href="http://www.apache-ssl.org/disclosure.pdf">Security against - Compelled Disclosure</A>, how to maintain privacy in the face of legal - or other coersion</LI> -</UL> -<H3><A name="compsec">Computer and network security</A></H3> -<H4><A name="seclink">Security links</A></H4> -<UL> -<LI><A href="http://www.cs.purdue.edu/coast/hotlist">COAST Hotlist</A></LI> -<LI>DMOZ open directory project<A href="http://dmoz.org/Computers/Security/"> - computer security</A> links</LI> -<LI><A href="http://www-cse.ucsd.edu/users/bsy/sec.html">Bennet Yee</A></LI> -<LI>Mike Fuhr's<A href="http://www.fuhr.org/~mfuhr/computers/security.html"> - link collection</A></LI> -<LI><A href="http://www.networkintrusion.co.uk/">links</A> with an - emphasis on intrusion detection</LI> -</UL> -<H4><A name="firewall.web">Firewall links</A></H4> -<UL> -<LI><A href="http://www.cs.purdue.edu/coast/firewalls">COAST firewalls</A> -</LI> -<LI><A href="http://www.zeuros.co.uk">Firewalls Resource page</A></LI> -</UL> -<H4><A name="vpn">VPN links</A></H4> -<UL> -<LI><A href="http://www.vpnc.org">VPN Consortium</A></LI> -<LI>First VPN's<A href="http://www.firstvpn.com/research/rhome.html"> - white paper</A> collection</LI> -</UL> -<H4><A name="tools">Security tools</A></H4> -<UL> -<LI>PGP -- mail encryption -<UL> -<LI><A href="http://www.pgp.com/">PGP Inc.</A> (part of NAI) for - commercial versions</LI> -<LI><A href="http://web.mit.edu/network/pgp.html">MIT</A> distributes - the NAI product for non-commercial use</LI> -<LI><A href="http://www.pgpi.org/">international</A> distribution site</LI> -<LI><A href="http://gnupg.org">GNU Privacy Guard (GPG)</A></LI> -<LI><A href="http://www.dk.pgp.net/pgpnet/pgp-faq/">PGP FAQ</A></LI> -</UL> - A message in our mailing list archive has considerable detail on<A href="http://www.sandelman.ottawa.on.ca/linux-ipsec/html/2000/12/msg00029.html"> - available versions</A> of PGP and on IPsec support in them. -<P><STRONG>Note:</STRONG> A fairly nasty bug exists in all commercial - PGP versions from 5.5 through 6.5.3. If you have one of those,<STRONG> - upgrade now</STRONG>.</P> -</LI> -<LI>SSH -- secure remote login -<UL> -<LI><A href="http://www.ssh.fi">SSH Communications Security</A>, for the - original software. It is free for trial, academic and non-commercial - use.</LI> -<LI><A href="http://www.openssh.com/">Open SSH</A>, the Open BSD team's - free replacement</LI> -<LI><A href="http://www.freessh.org/">freessh.org</A>, links to free - implementations for many systems</LI> -<LI><A href="http://www.uni-karlsruhe.de/~ig25/ssh-faq">SSH FAQ</A></LI> -<LI><A href="http://www.chiark.greenend.org.uk/~sgtatham/putty/">Putty</A> -, an SSH client for Windows</LI> -</UL> -</LI> -<LI>Tripwire saves message digests of your system files. Re-calculate - the digests and compare to saved values to detect any file changes. - There are several versions available: -<UL> -<LI><A href="http://www.tripwiresecurity.com/">commercial version</A></LI> -<LI><A href="http://www.tripwire.org/">Open Source</A></LI> -</UL> -</LI> -<LI><A href="http://www.snort.org">Snort</A> and<A href="http://www.lids.org"> - LIDS</A> are intrusion detection system for Linux</LI> -<LI><A href="http://www.fish.com/~zen/satan/satan.html">SATAN</A> System - Administrators Tool for Analysing Networks</LI> -<LI><A href="http://www.insecure.org/nmap/">NMAP</A> Network Mapper</LI> -<LI><A href="ftp://ftp.porcupine.org/pub/security/index.html">Wietse - Venema's page</A> with various tools</LI> -<LI><A href="http://ita.ee.lbl.gov/index.html">Internet Traffic Archive</A> -, various tools to analyze network traffic, mostly scripts to organise - and format tcpdump(8) output for specific purposes</LI> -<LI><A name="ssmail">ssmail -- sendmail patched to do</A><A href="glossary.html#carpediem"> - opportunistic encryption</A> -<UL> -<LI><A href="http://www.home.aone.net.au/qualcomm/">web page</A> with - links to code and to a Usenix paper describing it, in PDF</LI> -</UL> -</LI> -<LI><A href="http://www.openca.org/">Open CA</A> project to develop a - freely distributed<A href="glossary.html#CA"> Certification Authority</A> - for building a open<A href="glossary.html#PKI"> Public Key - Infrastructure</A>.</LI> -</UL> -<H3><A name="people">Links to home pages</A></H3> -<P>David Wagner at Berkeley provides a set of links to<A href="http://www.cs.berkeley.edu/~daw/people/crypto.html"> - home pages</A> of cryptographers, cypherpunks and computer security - people.</P> -<HR> -<A HREF="toc.html">Contents</A> -<A HREF="mail.html">Previous</A> -<A HREF="glossary.html">Next</A> -</BODY> -</HTML> |