diff options
Diffstat (limited to 'docs/configuration/vpn/sstp.rst')
-rw-r--r-- | docs/configuration/vpn/sstp.rst | 347 |
1 files changed, 347 insertions, 0 deletions
diff --git a/docs/configuration/vpn/sstp.rst b/docs/configuration/vpn/sstp.rst new file mode 100644 index 00000000..dbaa41c0 --- /dev/null +++ b/docs/configuration/vpn/sstp.rst @@ -0,0 +1,347 @@ +.. _sstp: + +#### +SSTP +#### + +:abbr:`SSTP (Secure Socket Tunneling Protocol)` is a form of :abbr:`VPN +(Virtual Private Network)` tunnel that provides a mechanism to transport PPP +traffic through an SSL/TLS channel. SSL/TLS provides transport-level security +with key negotiation, encryption and traffic integrity checking. The use of +SSL/TLS over TCP port 443 allows SSTP to pass through virtually all firewalls +and proxy servers except for authenticated web proxies. + +SSTP is available for Linux, BSD, and Windows. + +VyOS utilizes accel-ppp_ to provide SSTP server functionality. We support both +local and RADIUS authentication. + +As SSTP provides PPP via a SSL/TLS channel the use of either publically signed +certificates as well as a private PKI is required. + +.. note:: All certificates should be stored on VyOS under ``/config/auth``. If + certificates are not stored in the ``/config`` directory they will not be + migrated during a software update. + +Certificates +============ + +Self Signed CA +-------------- + +To generate the CA, the server private key and certificates the following +commands can be used. + +.. code-block:: none + + vyos@vyos:~$ mkdir -p /config/user-data/sstp + vyos@vyos:~$ openssl req -newkey rsa:4096 -new -nodes -x509 -days 3650 -keyout /config/user-data/sstp/server.key -out /config/user-data/sstp/server.crt + + Generating a 4096 bit RSA private key + .........................++ + ...............................................................++ + writing new private key to 'server.key' + [...] + Country Name (2 letter code) [AU]: + State or Province Name (full name) [Some-State]: + Locality Name (eg, city) []: + Organization Name (eg, company) [Internet Widgits Pty Ltd]: + Organizational Unit Name (eg, section) []: + Common Name (e.g. server FQDN or YOUR name) []: + Email Address []: + + vyos@vyos:~$ openssl req -new -x509 -key /config/user-data/sstp/server.key -out /config/user-data/sstp/ca.crt + [...] + Country Name (2 letter code) [AU]: + State or Province Name (full name) [Some-State]: + Locality Name (eg, city) []: + Organization Name (eg, company) [Internet Widgits Pty Ltd]: + Organizational Unit Name (eg, section) []: + Common Name (e.g. server FQDN or YOUR name) []: + Email Address []: + + +Configuration +============= + +.. cfgcmd:: set vpn sstp authentication local-users username <user> password <pass> + + Create `<user>` for local authentication on this system. The users password + will be set to `<pass>`. + +.. cfgcmd:: set vpn sstp authentication local-users username <user> disable + + Disable `<user>` account. + +.. cfgcmd:: set vpn sstp authentication local-users username <user> static-ip <address> + + Assign static IP address to `<user>` account. + +.. cfgcmd:: set vpn sstp authentication local-users username <user> rate-limit download <bandwidth> + + Download bandwidth limit in kbit/s for `<user>`. + +.. cfgcmd:: set vpn sstp authentication local-users username <user> rate-limit upload <bandwidth> + + Upload bandwidth limit in kbit/s for `<user>`. + +.. cfgcmd:: set vpn sstp authentication protocols <pap | chap | mschap | mschap-v2> + + Require the peer to authenticate itself using one of the following protocols: + pap, chap, mschap, mschap-v2. + +.. cfgcmd:: set vpn sstp authentication mode <local | radius> + + Set authentication backend. The configured authentication backend is used + for all queries. + + * **radius**: All authentication queries are handled by a configured RADIUS + server. + * **local**: All authentication queries are handled locally. + + +.. cfgcmd:: set vpn sstp gateway-address <gateway> + + Specifies single `<gateway>` IP address to be used as local address of PPP + interfaces. + + +.. cfgcmd:: set vpn sstp client-ip-pool subnet <subnet> + + Use `<subnet>` as the IP pool for all connecting clients. + + +.. cfgcmd:: set vpn sstp client-ipv6-pool prefix <address> mask <number-of-bits> + + Use this comand to set the IPv6 address pool from which an SSTP client + will get an IPv6 prefix of your defined length (mask) to terminate the + SSTP endpoint at their side. The mask length can be set from 48 to 128 + bit long, the default value is 64. + + +.. cfgcmd:: set vpn sstp client-ipv6-pool delegate <address> delegation-prefix <number-of-bits> + + Use this command to configure DHCPv6 Prefix Delegation (RFC3633) on + SSTP. You will have to set your IPv6 pool and the length of the + delegation prefix. From the defined IPv6 pool you will be handing out + networks of the defined length (delegation-prefix). The length of the + delegation prefix can be set from 32 to 64 bit long. + + +.. cfgcmd:: set vpn sstp name-server <address> + + Connected client should use `<address>` as their DNS server. This + command accepts both IPv4 and IPv6 addresses. Up to two nameservers + can be configured for IPv4, up to three for IPv6. + +Maximum number of IPv4 nameservers + +SSL Certificates +---------------- + +.. cfgcmd:: set vpn sstp ssl ca-cert-file <file> + + Path to `<file>` pointing to the certificate authority certificate. + +.. cfgcmd:: set vpn sstp ssl cert-file <file> + + Path to `<file>` pointing to the servers certificate (public portion). + +.. cfgcmd:: set vpn sstp ssl key-file <file> + + Path to `<file>` pointing to the servers certificate (private portion). + +PPP Settings +------------ + +.. cfgcmd:: set vpn sstp ppp-options lcp-echo-failure <number> + + Defines the maximum `<number>` of unanswered echo requests. Upon reaching the + value `<number>`, the session will be reset. + +.. cfgcmd:: set vpn sstp ppp-options lcp-echo-interval <interval> + + If this option is specified and is greater than 0, then the PPP module will + send LCP pings of the echo request every `<interval>` seconds. + +.. cfgcmd:: set vpn sstp ppp-options lcp-echo-timeout + + Specifies timeout in seconds to wait for any peer activity. If this option + specified it turns on adaptive lcp echo functionality and "lcp-echo-failure" + is not used. + +.. cfgcmd:: set vpn sstp ppp-options mppe <require | prefer | deny> + + Specifies :abbr:`MPPE (Microsoft Point-to-Point Encryption)` negotioation + preference. + + * **require** - ask client for mppe, if it rejects drop connection + * **prefer** - ask client for mppe, if it rejects don't fail + * **deny** - deny mppe + + Default behavior - don't ask client for mppe, but allow it if client wants. + Please note that RADIUS may override this option by MS-MPPE-Encryption-Policy + attribute. + + +RADIUS +------ + +Server +^^^^^^ + +.. cfgcmd:: set vpn sstp authentication radius server <server> port <port> + + Configure RADIUS `<server>` and its required port for authentication requests. + +.. cfgcmd:: set vpn sstp authentication radius server <server> key <secret> + + Configure RADIUS `<server>` and its required shared `<secret>` for + communicating with the RADIUS server. + +.. cfgcmd:: set vpn sstp authentication radius server <server> fail-time <time> + + Mark RADIUS server as offline for this given `<time>` in seconds. + +.. cfgcmd:: set vpn sstp authentication radius server <server> disable + + Temporary disable this RADIUS server. + +Options +^^^^^^^ + +.. cfgcmd:: set vpn sstp authentication radius acct-timeout <timeout> + + Timeout to wait reply for Interim-Update packets. (default 3 seconds) + +.. cfgcmd:: set vpn sstp authentication radius dynamic-author server <address> + + Specifies IP address for Dynamic Authorization Extension server (DM/CoA) + +.. cfgcmd:: set vpn sstp authentication radius dynamic-author port <port> + + Port for Dynamic Authorization Extension server (DM/CoA) + +.. cfgcmd:: set vpn sstp authentication radius dynamic-author key <secret> + + Secret for Dynamic Authorization Extension server (DM/CoA) + +.. cfgcmd:: set vpn sstp authentication radius max-try <number> + + Maximum number of tries to send Access-Request/Accounting-Request queries + +.. cfgcmd:: set vpn sstp authentication radius timeout <timeout> + + Timeout to wait response from server (seconds) + +.. cfgcmd:: set vpn sstp authentication radius nas-identifier <identifier> + + Value to send to RADIUS server in NAS-Identifier attribute and to be matched + in DM/CoA requests. + +.. cfgcmd:: set vpn sstp authentication radius nas-ip-address <address> + + Value to send to RADIUS server in NAS-IP-Address attribute and to be matched + in DM/CoA requests. Also DM/CoA server will bind to that address. + +.. cfgcmd:: set vpn sstp authentication radius source-address <address> + + Source IPv4 address used in all RADIUS server queires. + +.. cfgcmd:: set vpn sstp authentication radius rate-limit attribute <attribute> + + Specifies which RADIUS server attribute contains the rate limit information. + The default attribute is `Filter-Id`. + +.. cfgcmd:: set vpn sstp authentication radius rate-limit enable + + Enables bandwidth shaping via RADIUS. + +.. cfgcmd:: set vpn sstp authentication radius rate-limit vendor + + Specifies the vendor dictionary, dictionary needs to be in + /usr/share/accel-ppp/radius. + + +Example +======= + +* Use local user `foo` with password `bar` +* Client IP addresses will be provided from pool `192.0.2.0/25` + +.. code-block:: none + + set vpn sstp authentication local-users username vyos password vyos + set vpn sstp authentication mode local + set vpn sstp gateway-address 192.0.2.254 + set vpn sstp client-ip-pool subnet 192.0.2.0/25 + set vpn sstp name-server 10.0.0.1 + set vpn sstp name-server 10.0.0.2 + set vpn sstp ssl ca-cert-file /config/auth/ca.crt + set vpn sstp ssl cert-file /config/auth/server.crt + set vpn sstp ssl key-file /config/auth/server.key + +Testing SSTP +============ + +Once you have setup your SSTP server there comes the time to do some basic +testing. The Linux client used for testing is called sstpc_. sstpc_ requires a +PPP configuration/peer file. + +The following PPP configuration tests MSCHAP-v2: + +.. code-block:: none + + $ cat /etc/ppp/peers/vyos + usepeerdns + #require-mppe + #require-pap + require-mschap-v2 + noauth + lock + refuse-pap + refuse-eap + refuse-chap + refuse-mschap + #refuse-mschap-v2 + nobsdcomp + nodeflate + debug + + +You can now "dial" the peer with the follwoing command: ``sstpc --log-level 4 +--log-stderr --user vyos --password vyos vpn.example.com -- call vyos``. + +A connection attempt will be shown as: + +.. code-block:: none + + $ sstpc --log-level 4 --log-stderr --user vyos --password vyos vpn.example.com -- call vyos + + Mar 22 13:29:12 sstpc[12344]: Resolved vpn.example.com to 192.0.2.1 + Mar 22 13:29:12 sstpc[12344]: Connected to vpn.example.com + Mar 22 13:29:12 sstpc[12344]: Sending Connect-Request Message + Mar 22 13:29:12 sstpc[12344]: SEND SSTP CRTL PKT(14) + Mar 22 13:29:12 sstpc[12344]: TYPE(1): CONNECT REQUEST, ATTR(1): + Mar 22 13:29:12 sstpc[12344]: ENCAP PROTO(1): 6 + Mar 22 13:29:12 sstpc[12344]: RECV SSTP CRTL PKT(48) + Mar 22 13:29:12 sstpc[12344]: TYPE(2): CONNECT ACK, ATTR(1): + Mar 22 13:29:12 sstpc[12344]: CRYPTO BIND REQ(4): 40 + Mar 22 13:29:12 sstpc[12344]: Started PPP Link Negotiation + Mar 22 13:29:15 sstpc[12344]: Sending Connected Message + Mar 22 13:29:15 sstpc[12344]: SEND SSTP CRTL PKT(112) + Mar 22 13:29:15 sstpc[12344]: TYPE(4): CONNECTED, ATTR(1): + Mar 22 13:29:15 sstpc[12344]: CRYPTO BIND(3): 104 + Mar 22 13:29:15 sstpc[12344]: Connection Established + + $ ip addr show ppp0 + 164: ppp0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1452 qdisc fq_codel state UNKNOWN group default qlen 3 + link/ppp promiscuity 0 + inet 100.64.2.2 peer 100.64.1.1/32 scope global ppp0 + valid_lft forever preferred_lft forever + + + +.. _sstpc: https://github.com/reliablehosting/sstp-client + +.. include:: /_include/common-references.txt |