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| -rw-r--r-- | README.rst | 164 | ||||
| -rw-r--r-- | changelog.d/4547.misc | 1 |
2 files changed, 82 insertions, 83 deletions
diff --git a/README.rst b/README.rst index e6354ccba0..02828966c9 100644 --- a/README.rst +++ b/README.rst @@ -216,16 +216,77 @@ different. See `the spec`__ for more information on key management.) The default configuration exposes two HTTP ports: 8008 and 8448. Port 8008 is configured without TLS; it should be behind a reverse proxy for TLS/SSL termination on port 443 which in turn should be used for clients. Port 8448 -is configured to use TLS with a self-signed certificate. If you would like -to do initial test with a client without having to setup a reverse proxy, -you can temporarly use another certificate. (Note that a self-signed -certificate is fine for `Federation`_). You can do so by changing -``tls_certificate_path`` and ``tls_private_key_path`` -in ``homeserver.yaml``; alternatively, you can use a reverse-proxy, but be sure -to read `Using a reverse proxy with Synapse`_ when doing so. +is configured to use TLS for `Federation`_ with a self-signed or verified +certificate, but please be aware that a valid certificate will be required in +Synapse v1.0. -Apart from port 8448 using TLS, both ports are the same in the default -configuration. + +ACME setup +---------- + +Synapse v1.0 requires valid TLS certificates for communication between servers +(port ``8448`` by default) in addition to those that are client-facing (port +``443``). In the case that your `server_name` config variable is the same as +the hostname that the client connects to, then the same certificate can be +used between client and federation ports without issue. Synapse v0.99.0+ +**will provision server-to-server certificates automatically for you for +free** through `Let's Encrypt +<https://letsencrypt.org/>`_ if you tell it to. + +In order for Synapse to complete the ACME challenge to provision a +certificate, it needs access to port 80. Typically listening on port 80 is +only granted to applications running as root. There are thus two solutions to +this problem. + +**Using a reverse proxy** + +A reverse proxy such as Apache or Nginx allows a single process (the web +server) to listen on port 80 and proxy traffic to the appropriate program +running on your server. It is the recommended method for setting up ACME as +it allows you to use your existing webserver while also allowing Synapse to +provision certificates as needed. + +For Nginx users, add the following line to your existing ``server`` block:: + + location /.well-known/acme-challenge { + proxy_pass http://localhost:8009/; + } + +For Apache, add the following to your existing webserver config:: + + ProxyPass /.well-known/acme-challenge http://localhost:8009/.well-known/acme-challenge + +Make sure to restart/reload your webserver after making changes. + + +**Authbind** + +``authbind`` allows a program which does not or should not run as root to +bind to low-numbered ports in a controlled way. The setup is simpler, but +requires a webserver not to already be running on port 80. **This includes +every time Synapse renews a certificate**, which may be cumbersome if you +usually run a web server on port 80. Nevertheless, if you're sure port 80 is +not being used for any other purpose then all that is necessary is the +following: + +Install ``authbind``. For example, on Debian/Ubuntu:: + + sudo apt-get install authbind + +Allow ``authbind`` to bind port 80:: + + sudo touch /etc/authbind/byport/80 + sudo chmod 777 /etc/authbind/byport/80 + +When Synapse is started, use the following syntax:: + + authbind --deep <synapse start command> + +If you would like to use your own certificates, you can do so by +changing ``tls_certificate_path`` and ``tls_private_key_path`` in +``homeserver.yaml``; alternatively, you can use a reverse-proxy, but be sure +to read `Using a reverse proxy with Synapse`_ when doing so. Apart from port +8448 using TLS, both ports are the same in the default configuration. Registering a user ------------------ @@ -281,10 +342,11 @@ following the recommended setup, or ``https://localhost:8448`` - remember to spe port (``:8448``) if not ``:443`` unless you changed the configuration. (Leave the identity server as the default - see `Identity servers`_.) -If using port 8448 you will run into errors until you accept the self-signed -certificate. You can easily do this by going to ``https://localhost:8448`` +If using port 8448 you will run into errors if you are using a self-signed +certificate. To overcome this, simply go to ``https://localhost:8448`` directly with your browser and accept the presented certificate. You can then -go back in your web client and proceed further. +go back in your web client and proceed further. Valid federation certificates +should not have this problem. If all goes well you should at least be able to log in, create a room, and start sending messages. @@ -553,9 +615,7 @@ you to run your server on a machine that might not have the same name as your domain name. For example, you might want to run your server at ``synapse.example.com``, but have your Matrix user-ids look like ``@user:example.com``. (A SRV record also allows you to change the port from -the default 8448. However, if you are thinking of using a reverse-proxy on the -federation port, which is not recommended, be sure to read -`Reverse-proxying the federation port`_ first.) +the default 8448). To use a SRV record, first create your SRV record and publish it in DNS. This should have the format ``_matrix._tcp.<yourdomain.com> <ttl> IN SRV 10 0 <port> @@ -593,6 +653,8 @@ Troubleshooting You can use the federation tester to check if your homeserver is all set: ``https://matrix.org/federationtester/api/report?server_name=<your_server_name>`` If any of the attributes under "checks" is false, federation won't work. +There is also a nicer interface available from a community member at +`<https://neo.lain.haus/fed-tester>`_. The typical failure mode with federation is that when you try to join a room, it is rejected with "401: Unauthorized". Generally this means that other @@ -601,8 +663,6 @@ complicated dance which requires connections in both directions). So, things to check are: -* If you are trying to use a reverse-proxy, read `Reverse-proxying the - federation port`_. * If you are not using a SRV record, check that your ``server_name`` (the part of your user-id after the ``:``) matches your hostname, and that port 8448 on that hostname is reachable from outside your network. @@ -657,14 +717,10 @@ port. Indeed, clients will use port 443 by default, whereas servers default to port 8448. Where these are different, we refer to the 'client port' and the 'federation port'. -The next most important thing to know is that using a reverse-proxy on the -federation port has a number of pitfalls. It is possible, but be sure to read -`Reverse-proxying the federation port`_. - -The recommended setup is therefore to configure your reverse-proxy on port 443 -to port 8008 of synapse for client connections, but to also directly expose port -8448 for server-server connections. All the Matrix endpoints begin ``/_matrix``, -so an example nginx configuration might look like:: +The recommended setup is therefore to configure your reverse-proxy on port +443 to port 8008 of synapse for client connections, and port 8448 for +server-server connections. All Matrix endpoints begin with ``/_matrix``, so an +example nginx configuration might look like:: server { listen 443 ssl; @@ -705,64 +761,6 @@ Having done so, you can then use ``https://matrix.example.com`` (instead of ``https://matrix.example.com:8448``) as the "Custom server" when `Connecting to Synapse from a client`_. -Reverse-proxying the federation port ------------------------------------- - -There are two issues to consider before using a reverse-proxy on the federation -port: - -* Due to the way SSL certificates are managed in the Matrix federation protocol - (see `spec`__), Synapse needs to be configured with the path to the SSL - certificate, *even if you do not terminate SSL at Synapse*. - - .. __: `key_management`_ - -* Until v0.33.3, Synapse did not support SNI on the federation port - (`bug #1491 <https://github.com/matrix-org/synapse/issues/1491>`_). This bug - is now fixed, but means that federating with older servers can be unreliable - when using name-based virtual hosting. - -Furthermore, a number of the normal reasons for using a reverse-proxy do not -apply: - -* Other servers will connect on port 8448 by default, so there is no need to - listen on port 443 (for federation, at least), which avoids the need for root - privileges and virtual hosting. - -* A self-signed SSL certificate is fine for federation, so there is no need to - automate renewals. (The certificate generated by ``--generate-config`` is - valid for 10 years.) - -If you want to set up a reverse-proxy on the federation port despite these -caveats, you will need to do the following: - -* In ``homeserver.yaml``, set ``tls_certificate_path`` to the path to the SSL - certificate file used by your reverse-proxy, and set ``no_tls`` to ``True``. - (``tls_private_key_path`` will be ignored if ``no_tls`` is ``True``.) - -* In your reverse-proxy configuration: - - * If there are other virtual hosts on the same port, make sure that the - *default* one uses the certificate configured above. - - * Forward ``/_matrix`` to Synapse. - -* If your reverse-proxy is not listening on port 8448, publish a SRV record to - tell other servers how to find you. See `Setting up Federation`_. - -When updating the SSL certificate, just update the file pointed to by -``tls_certificate_path`` and then restart Synapse. (You may like to use a symbolic link -to help make this process atomic.) - -The most common mistake when setting up federation is not to tell Synapse about -your SSL certificate. To check it, you can visit -``https://matrix.org/federationtester/api/report?server_name=<your_server_name>``. -Unfortunately, there is no UI for this yet, but, you should see -``"MatchingTLSFingerprint": true``. If not, check that -``Certificates[0].SHA256Fingerprint`` (the fingerprint of the certificate -presented by your reverse-proxy) matches ``Keys.tls_fingerprints[0].sha256`` -(the fingerprint of the certificate Synapse is using). - Identity Servers ================ diff --git a/changelog.d/4547.misc b/changelog.d/4547.misc new file mode 100644 index 0000000000..b6e421d095 --- /dev/null +++ b/changelog.d/4547.misc @@ -0,0 +1 @@ +Add docs for ACME setup to README. \ No newline at end of file |