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| -rw-r--r-- | docs/configuration/interfaces/openvpn.rst | 173 |
1 files changed, 111 insertions, 62 deletions
diff --git a/docs/configuration/interfaces/openvpn.rst b/docs/configuration/interfaces/openvpn.rst index c0019577..2160e781 100644 --- a/docs/configuration/interfaces/openvpn.rst +++ b/docs/configuration/interfaces/openvpn.rst @@ -40,30 +40,27 @@ Site-to-Site .. figure:: /_static/images/openvpn_site2site_diagram.jpg -While many are aware of OpenVPN as a Client VPN solution, it is often -overlooked as a site-to-site VPN solution due to lack of support for this mode -in many router platforms. +OpenVPN is popular for client-server setups, but its site-to-site mode +remains a relatively obscure feature, and many router appliances +still don't support it. However, it's very useful for quickly setting up +tunnels between routers. -Site-to-site mode supports x.509 but doesn't require it and can also work with -static keys, which is simpler in many cases. In this example, we'll configure -a simple site-to-site OpenVPN tunnel using a 2048-bit pre-shared key. +As of VyOS 1.4, OpenVPN site-to-site mode can use either pre-shared keys or x.509 certificates. -First, one of the systems generate the key using the :ref:`generate pki openvpn shared-secret<configuration/pki/index:pki>` -command. Once generated, you will need to install this key on the local system, -then copy and install this key to the remote router. +The pre-shared key mode is deprecated and will be removed from future OpenVPN versions, +so VyOS will have to remove support for that option as well. The reason is that using pre-shared keys +is significantly less secure than using TLS. -In our example, we used the key name ``openvpn-1`` which we will reference -in our configuration. +We'll configure OpenVPN using self-signed certificates, and then discuss the legacy +pre-shared key mode. + +In both cases, we will use the following settings: * The public IP address of the local side of the VPN will be 198.51.100.10. * The public IP address of the remote side of the VPN will be 203.0.113.11. * The tunnel will use 10.255.1.1 for the local IP and 10.255.1.2 for the remote. * The local site will have a subnet of 10.0.0.0/16. * The remote site will have a subnet of 10.1.0.0/16. -* Static Routing or other dynamic routing protocols can be used over the vtun interface -* OpenVPN allows for either TCP or UDP. UDP will provide the lowest latency, - while TCP will work better for lossy connections; generally UDP is preferred - when possible. * The official port for OpenVPN is 1194, which we reserve for client VPN; we will use 1195 for site-to-site VPN. * The ``persistent-tunnel`` directive will allow us to configure tunnel-related @@ -73,85 +70,137 @@ in our configuration. ``remote-host`` directive; if unknown, it can be omitted. We will assume a dynamic IP for our remote router. +Setting up certificates +----------------------- -Local Configuration: +Setting up a full-blown PKI with a CA certificate would arguably defeat the purpose +of site-to-site OpenVPN, since its main goal is supposed to be configuration simplicity, +compared to server setups that need to support multiple clients. -.. code-block:: none +However, since VyOS 1.4, it is possible to verify self-signed certificates using +certificate fingerprints. - run generate pki openvpn shared-secret install openvpn-1 - Configure mode commands to install OpenVPN key: - set pki openvpn shared-secret openvpn-1 key 'generated_key_string' - set pki openvpn shared-secret openvpn-1 version '1' +On both sides, you need to generate a self-signed certificate, preferrably using the "ec" (elliptic curve) type. +You can generate them by executing command ``run generate pki certificate self-signed install <name>`` in the configuration mode. +Once the command is complete, it will add the certificate to the configuration session, to the ``pki`` subtree. +You can then review the proposed changes and commit them. - set interfaces openvpn vtun1 mode site-to-site - set interfaces openvpn vtun1 protocol udp - set interfaces openvpn vtun1 persistent-tunnel - set interfaces openvpn vtun1 remote-host '203.0.113.11' - set interfaces openvpn vtun1 local-port '1195' - set interfaces openvpn vtun1 remote-port '1195' - set interfaces openvpn vtun1 shared-secret-key openvpn-1 - set interfaces openvpn vtun1 local-address '10.255.1.1' - set interfaces openvpn vtun1 remote-address '10.255.1.2' +.. code-block:: none -Local Configuration - Annotated: + vyos@vyos# run generate pki certificate self-signed install openvpn-local + Enter private key type: [rsa, dsa, ec] (Default: rsa) ec + Enter private key bits: (Default: 256) + Enter country code: (Default: GB) + Enter state: (Default: Some-State) + Enter locality: (Default: Some-City) + Enter organization name: (Default: VyOS) + Enter common name: (Default: vyos.io) + Do you want to configure Subject Alternative Names? [y/N] + Enter how many days certificate will be valid: (Default: 365) + Enter certificate type: (client, server) (Default: server) + Note: If you plan to use the generated key on this router, do not encrypt the private key. + Do you want to encrypt the private key with a passphrase? [y/N] + 2 value(s) installed. Use "compare" to see the pending changes, and "commit" to apply. + [edit] + + vyos@vyos# compare + [pki] + + certificate openvpn-local { + + certificate "MIICJTCCAcugAwIBAgIUMXLfRNJ5iOjk/ 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" + + private { + + key "MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQgtOeEb0dMb5P/2Exi09WWvk6Cvz0oOBoDuP68ZimS2LShRANCAASp7D0vE3SKSAWAzr/lw9Eq9Q89r247AJR6ec/GT26AIcVA1bsongV1YaWvRwzTPC/yi5pkzV/PcT/WU7JQIyMW" + + } + + } + + [edit] + + vyos@vyos# commit + +You do **not** need to copy the certificate to the other router. Instead, you need to retrieve its SHA-256 fingerprint. +OpenVPN only supports SHA-256 fingerprints at the moment, so you need to use the following command: .. code-block:: none - run generate pki openvpn shared-secret install openvpn-1 # Locally genearated OpenVPN shared secret. - The generated secret is the output to - the console. - Configure mode commands to install OpenVPN key: - set pki openvpn shared-secret openvpn-1 key 'generated_key_string' # Generated secret displayed in the output to - the console. - set pki openvpn shared-secret openvpn-1 version '1' # Generated secret displayed in the output to - the console. + vyos@vyos# run show pki certificate openvpn-local fingerprint sha256 + 5C:B8:09:64:8B:59:51:DC:F4:DF:2C:12:5C:B7:03:D1:68:94:D7:5B:62:C2:E1:83:79:F1:F0:68:B2:81:26:79 - set interfaces openvpn vtun1 mode site-to-site - set interfaces openvpn vtun1 protocol udp - set interfaces openvpn vtun1 persistent-tunnel - set interfaces openvpn vtun1 remote-host '203.0.113.11' # Pub IP of other site - set interfaces openvpn vtun1 local-port '1195' - set interfaces openvpn vtun1 remote-port '1195' - set interfaces openvpn vtun1 shared-secret-key openvpn-1 # Locally generated secret name - set interfaces openvpn vtun1 local-address '10.255.1.1' # Local IP of vtun interface - set interfaces openvpn vtun1 remote-address '10.255.1.2' # Remote IP of vtun interface +Note: certificate names don't matter, we use 'openvpn-local' and 'openvpn-remote' but they can be arbitrary. +Repeat the procedure on the other router. -Remote Configuration: +Setting up OpenVPN +------------------ + +Local Configuration: .. code-block:: none - set pki openvpn shared-secret openvpn-1 key 'generated_key_string' - set pki openvpn shared-secret openvpn-1 version '1' + Configure the tunnel: set interfaces openvpn vtun1 mode site-to-site set interfaces openvpn vtun1 protocol udp set interfaces openvpn vtun1 persistent-tunnel - set interfaces openvpn vtun1 remote-host '198.51.100.10' + set interfaces openvpn vtun1 remote-host '203.0.113.11' # Public IP of the other side set interfaces openvpn vtun1 local-port '1195' set interfaces openvpn vtun1 remote-port '1195' - set interfaces openvpn vtun1 shared-secret-key openvpn-1 - set interfaces openvpn vtun1 local-address '10.255.1.2' - set interfaces openvpn vtun1 remote-address '10.255.1.1' - -Remote Configuration - Annotated: + set interfaces openvpn vtun1 local-address '10.255.1.1' # Local IP of vtun interface + set interfaces openvpn vtun1 remote-address '10.255.1.2' # Remote IP of vtun interface + set interfaces openvpn vtun1 tls certificate 'openvpn-local' # The self-signed certificate + set interfaces openvpn vtun1 tls peer-fingerprint <remote cert fingerprint> # The output of 'run show pki certificate <name> fingerprint sha256 + on the remote rout +Remote Configuration: .. code-block:: none - set pki openvpn shared-secret openvpn-1 key 'generated_key_string' # Locally genearated OpenVPN shared secret - (from the Local Configuration Block). - set pki openvpn shared-secret openvpn-1 version '1' - set interfaces openvpn vtun1 mode site-to-site set interfaces openvpn vtun1 protocol udp set interfaces openvpn vtun1 persistent-tunnel set interfaces openvpn vtun1 remote-host '198.51.100.10' # Pub IP of other site set interfaces openvpn vtun1 local-port '1195' set interfaces openvpn vtun1 remote-port '1195' - set interfaces openvpn vtun1 shared-secret-key openvpn-1 # Locally generated secret name set interfaces openvpn vtun1 local-address '10.255.1.2' # Local IP of vtun interface set interfaces openvpn vtun1 remote-address '10.255.1.1' # Remote IP of vtun interface + set interfaces openvpn vtun1 tls certificate 'openvpn-remote' # The self-signed certificate + set interfaces openvpn vtun1 tls peer-fingerprint <local cert fingerprint> # The output of 'run show pki certificate <name> fingerprint sha256 + on the local router +Pre-shared keys +--------------- + +Until VyOS 1.4, the only option for site-to-site OpenVPN without PKI was to use pre-shared keys. +That option is still available but it is deprecated and will be removed in the future. +However, if you need to set up a tunnel to an older VyOS version or a system with older OpenVPN, +you need to still need to know how to use it. + +First, you need to generate a key by running ``run generate pki openvpn shared-secret install <name>`` from configuration mode. +You can use any name, we will use ``s2s``. + +.. code-block:: none + vyos@local# run generate pki openvpn shared-secret install s2s + 2 value(s) installed. Use "compare" to see the pending changes, and "commit" to apply. + [edit] + vyos@local# compare + [pki openvpn shared-secret] + + s2s { + + key "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" + + version "1" + + } + + [edit] + + vyos@local# commit + [edit] + +Then you need to install the key on the remote router: + +.. code-block:: none + + vyos@remote# set pki openvpn shared-secret s2s key <generated key string> + +Then you need to set the key in your OpenVPN interface settings: + +.. code-block:: none + set interfaces openvpn vtun1 shared-secret-key s2s Firewall Exceptions =================== |