From aaa0331ecf95ced1e913ac9be50168cf0e7cbb82 Mon Sep 17 00:00:00 2001 From: Rene Mayrhofer Date: Tue, 30 Jan 2007 12:21:07 +0000 Subject: [svn-upgrade] Integrating new upstream version, strongswan (2.8.2) --- doc/src/testing.html | 395 --------------------------------------------------- 1 file changed, 395 deletions(-) delete mode 100644 doc/src/testing.html (limited to 'doc/src/testing.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 @@ - - -Testing FreeS/WAN - - - - - - - -

Testing FreeS/WAN

-This document discusses testing FreeS/WAN. - -

Not all types of testing are described here. Other parts of the -documentation describe some tests:

-
-
installation document
-
testing for a successful install
-
configuration document
-
basic tests for a working configuration
-
web links document
-
General information on tests for interoperability between various - IPsec implementations. This includes links to several test sites.
-
interoperation document.
-
More specific information on FreeS/WAN interoperation with other - implementations.
-
performance document
-
performance measurements
-
- -

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.

- -

Testing opportunistic connections

- -

This section teaches you how to test your opportunistically encrypted (OE) -connections. To set up OE, please see the easy instructions in our -quickstart guide.

- -

Basic OE Test

- - -

This test is for basic OE functionality. - -For additional tests, keep reading.

- -

Be sure IPsec is running. You can see whether it is with:

-
    ipsec setup status
-

If need be, you can restart it with:

-
    service ipsec restart
- -

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:

-

   links oetest.freeswan.org
-
   links oetest.freeswan.nl
- - -

A positive result looks like this:

- -
-   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
-
- -

If you see this, congratulations! Your OE box will now encrypt -its own traffic whenever it can. If you have difficulty, -see our OE troubleshooting tips. -

- -

OE Gateway Test

-

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 each protected subnet node, -load the FreeS/WAN website with:

- -
   links oetest.freeswan.org
-
   links oetest.freeswan.nl
- -

A positive result looks like this:

-
-   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
-
- -

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 -OE troubleshooting tips. -

- - -

Additional OE tests

- -

When testing OE, you will often find it useful to execute this command -on the FreeS/WAN host:

-
   ipsec eroute
- -

If you have established a connection (either for or for a subnet node) -you will see a result like:

- -
    192.0.2.11/32   -> 192.139.46.73/32  => tun0x149f@192.139.46.38
-
- -

Key:

- - - - - - - - - - - - - -
1.192.0.2.11/32Local start point of the protected traffic. -
2.192.0.2.194/32Remote end point of the protected traffic. -
3.192.0.48.38Remote FreeS/WAN node (gateway or host). - May be the same as (2). -
4.[not shown]Local FreeS/WAN node (gateway or host), where you've produced the output. - May be the same as (1). -
- - -

For extra assurance, you may wish to use a packet sniffer such as -tcpdump to verify that packets -are being encrypted. You should see output that indicates -ESP encrypted data, - for example:

- -
    02:17:47.353750 PPPoE  [ses 0x1e12] IP 154: xy.example.com > oetest.freeswan.org: ESP(spi=0x87150d16,seq=0x55)
- - - -

Testing with User Mode Linux

- -

User Mode Linux -allows you to run Linux as a user process on another Linux machine.

- -

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.

- -

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.

- -Documentation on these -scripts is here. There is also documentation -on automated testing here. - -

Configuration for a testbed network

- -

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.

- -

The central machine both routes packets and provides a place to run -diagnostic software for checking IPsec packets. See next section for -discussion of using tcpdump(8) for this.

- -

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.

- -

What you end up with looks like:

- -

Testbed network

-
      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
-
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:
-
conn abc-xyz
-      left=192.168.p.1
-      leftnexthop=192.168.p.2
-      right=192.168.q.1
-      rightnexthop=192.168.q.2
- -

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.

- -

Note that nothing on either subnet needs to change. This lets you test -most of your IPsec setup before connecting to the insecure Internet.

- -

Using packet sniffers in testing

- -

A number of tools are available for looking at packets. We will discuss -using tcpdump(8), a common Linux tool -included in most distributions. Alternatives offerring more-or-less the same -functionality include:

-
-
Ethereal
-
Several people on our mailing list report a preference for this over - tcpdump.
-
windump
-
a Windows version of tcpdump(8), possibly handy if you have Windows - boxes in your network
-
Sniffit
-
A linux sniffer that we don't know much about. If you use it, please - comment on our mailing list.
-
- -

See also this index of packet -sniffers.

- -

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.

- -

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 tcpdump.org.

- -

Even with a recent tcpdump, some care is required. Here is part of a post -from Henry on the topic:

-
> 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).
- -

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 separate sniffer machine located between the two -gateways. This machine can be routing IPsec packets, but it must not -be an IPsec gateway. Network configuration for such testing is discussed above.

- -

Here's another mailing list message with advice on using tcpdump(8):

-
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....)
- -

Verifying encryption

- -

The question of how to verify that messages are actually encrypted has -been extensively discussed on the mailing list. See this thread.

- -

If you just want to verify that packets are encrypted, look at them with a -packet sniffer (see previous section) located -between the gateways. The packets should, except for some of the header -information, be utterly unintelligible. The output of good encryption -looks exactly like random noise.

- -

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.

- -

You can put recognizable data into ping packets with something like:

-
        ping -p feedfacedeadbeef 11.0.1.1
- -

"feedfacedeadbeef" is a legal hexadecimal pattern that is easy to pick out -of hex dumps.

- -

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.

- -

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.

- -

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.

- -

For IPsec, you can get partial assurance from interoperability tests. See -our interop document. When twenty products all -claim to implement 3DES, 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.

- -

Mailing list pointers

- -

Additional information on testing can be found in these mailing list messages:

- - - -- cgit v1.2.3