diff options
| -rw-r--r-- | changelog.d/14293.doc | 1 | ||||
| -rw-r--r-- | docs/SUMMARY.md | 2 | ||||
| -rw-r--r-- | docs/setup/turn/coturn.md | 188 | ||||
| -rw-r--r-- | docs/setup/turn/eturnal.md | 170 | ||||
| -rw-r--r-- | docs/turn-howto.md | 240 |
5 files changed, 390 insertions, 211 deletions
diff --git a/changelog.d/14293.doc b/changelog.d/14293.doc new file mode 100644 index 0000000000..d6410421e7 --- /dev/null +++ b/changelog.d/14293.doc @@ -0,0 +1 @@ +Add addtional TURN server configuration example based on [eturnal](https://github.com/processone/eturnal) and adjust general TURN server doc structure. diff --git a/docs/SUMMARY.md b/docs/SUMMARY.md index 16720bceb5..8d68719958 100644 --- a/docs/SUMMARY.md +++ b/docs/SUMMARY.md @@ -9,6 +9,8 @@ - [Configuring a Reverse Proxy](reverse_proxy.md) - [Configuring a Forward/Outbound Proxy](setup/forward_proxy.md) - [Configuring a Turn Server](turn-howto.md) + - [coturn TURN server](setup/turn/coturn.md) + - [eturnal TURN server](setup/turn/eturnal.md) - [Delegation](delegate.md) # Upgrading diff --git a/docs/setup/turn/coturn.md b/docs/setup/turn/coturn.md new file mode 100644 index 0000000000..a1bb1e934c --- /dev/null +++ b/docs/setup/turn/coturn.md @@ -0,0 +1,188 @@ +# coturn TURN server + +The following sections describe how to install [coturn](<https://github.com/coturn/coturn>) (which implements the TURN REST API). + +## `coturn` setup + +### Initial installation + +The TURN daemon `coturn` is available from a variety of sources such as native package managers, or installation from source. + +#### Debian and Ubuntu based distributions + +Just install the debian package: + +```sh +sudo apt install coturn +``` + +This will install and start a systemd service called `coturn`. + +#### Source installation + +1. Download the [latest release](https://github.com/coturn/coturn/releases/latest) from github. Unpack it and `cd` into the directory. + +1. Configure it: + + ```sh + ./configure + ``` + + You may need to install `libevent2`: if so, you should do so in + the way recommended by your operating system. You can ignore + warnings about lack of database support: a database is unnecessary + for this purpose. + +1. Build and install it: + + ```sh + make + sudo make install + ``` + +### Configuration + +1. Create or edit the config file in `/etc/turnserver.conf`. The relevant + lines, with example values, are: + + ``` + use-auth-secret + static-auth-secret=[your secret key here] + realm=turn.myserver.org + ``` + + See `turnserver.conf` for explanations of the options. One way to generate + the `static-auth-secret` is with `pwgen`: + + ```sh + pwgen -s 64 1 + ``` + + A `realm` must be specified, but its value is somewhat arbitrary. (It is + sent to clients as part of the authentication flow.) It is conventional to + set it to be your server name. + +1. You will most likely want to configure `coturn` to write logs somewhere. The + easiest way is normally to send them to the syslog: + + ```sh + syslog + ``` + + (in which case, the logs will be available via `journalctl -u coturn` on a + systemd system). Alternatively, `coturn` can be configured to write to a + logfile - check the example config file supplied with `coturn`. + +1. Consider your security settings. TURN lets users request a relay which will + connect to arbitrary IP addresses and ports. The following configuration is + suggested as a minimum starting point: + + ``` + # VoIP traffic is all UDP. There is no reason to let users connect to arbitrary TCP endpoints via the relay. + no-tcp-relay + + # don't let the relay ever try to connect to private IP address ranges within your network (if any) + # given the turn server is likely behind your firewall, remember to include any privileged public IPs too. + denied-peer-ip=10.0.0.0-10.255.255.255 + denied-peer-ip=192.168.0.0-192.168.255.255 + denied-peer-ip=172.16.0.0-172.31.255.255 + + # recommended additional local peers to block, to mitigate external access to internal services. + # https://www.rtcsec.com/article/slack-webrtc-turn-compromise-and-bug-bounty/#how-to-fix-an-open-turn-relay-to-address-this-vulnerability + no-multicast-peers + denied-peer-ip=0.0.0.0-0.255.255.255 + denied-peer-ip=100.64.0.0-100.127.255.255 + denied-peer-ip=127.0.0.0-127.255.255.255 + denied-peer-ip=169.254.0.0-169.254.255.255 + denied-peer-ip=192.0.0.0-192.0.0.255 + denied-peer-ip=192.0.2.0-192.0.2.255 + denied-peer-ip=192.88.99.0-192.88.99.255 + denied-peer-ip=198.18.0.0-198.19.255.255 + denied-peer-ip=198.51.100.0-198.51.100.255 + denied-peer-ip=203.0.113.0-203.0.113.255 + denied-peer-ip=240.0.0.0-255.255.255.255 + + # special case the turn server itself so that client->TURN->TURN->client flows work + # this should be one of the turn server's listening IPs + allowed-peer-ip=10.0.0.1 + + # consider whether you want to limit the quota of relayed streams per user (or total) to avoid risk of DoS. + user-quota=12 # 4 streams per video call, so 12 streams = 3 simultaneous relayed calls per user. + total-quota=1200 + ``` + +1. Also consider supporting TLS/DTLS. To do this, add the following settings + to `turnserver.conf`: + + ``` + # TLS certificates, including intermediate certs. + # For Let's Encrypt certificates, use `fullchain.pem` here. + cert=/path/to/fullchain.pem + + # TLS private key file + pkey=/path/to/privkey.pem + + # Ensure the configuration lines that disable TLS/DTLS are commented-out or removed + #no-tls + #no-dtls + ``` + + In this case, replace the `turn:` schemes in the `turn_uris` settings below + with `turns:`. + + We recommend that you only try to set up TLS/DTLS once you have set up a + basic installation and got it working. + + NB: If your TLS certificate was provided by Let's Encrypt, TLS/DTLS will + not work with any Matrix client that uses Chromium's WebRTC library. This + currently includes Element Android & iOS; for more details, see their + [respective](https://github.com/vector-im/element-android/issues/1533) + [issues](https://github.com/vector-im/element-ios/issues/2712) as well as the underlying + [WebRTC issue](https://bugs.chromium.org/p/webrtc/issues/detail?id=11710). + Consider using a ZeroSSL certificate for your TURN server as a working alternative. + +1. Ensure your firewall allows traffic into the TURN server on the ports + you've configured it to listen on (By default: 3478 and 5349 for TURN + traffic (remember to allow both TCP and UDP traffic), and ports 49152-65535 + for the UDP relay.) + +1. If your TURN server is behind NAT, the NAT gateway must have an external, + publicly-reachable IP address. You must configure `coturn` to advertise that + address to connecting clients: + + ``` + external-ip=EXTERNAL_NAT_IPv4_ADDRESS + ``` + + You may optionally limit the TURN server to listen only on the local + address that is mapped by NAT to the external address: + + ``` + listening-ip=INTERNAL_TURNSERVER_IPv4_ADDRESS + ``` + + If your NAT gateway is reachable over both IPv4 and IPv6, you may + configure `coturn` to advertise each available address: + + ``` + external-ip=EXTERNAL_NAT_IPv4_ADDRESS + external-ip=EXTERNAL_NAT_IPv6_ADDRESS + ``` + + When advertising an external IPv6 address, ensure that the firewall and + network settings of the system running your TURN server are configured to + accept IPv6 traffic, and that the TURN server is listening on the local + IPv6 address that is mapped by NAT to the external IPv6 address. + +1. (Re)start the turn server: + + * If you used the Debian package (or have set up a systemd unit yourself): + ```sh + sudo systemctl restart coturn + ``` + + * If you built from source: + + ```sh + /usr/local/bin/turnserver -o + ``` diff --git a/docs/setup/turn/eturnal.md b/docs/setup/turn/eturnal.md new file mode 100644 index 0000000000..2e5a45673e --- /dev/null +++ b/docs/setup/turn/eturnal.md @@ -0,0 +1,170 @@ +# eturnal TURN server + +The following sections describe how to install [eturnal](<https://github.com/processone/eturnal>) +(which implements the TURN REST API). + +## `eturnal` setup + +### Initial installation + +The `eturnal` TURN server implementation is available from a variety of sources +such as native package managers, binary packages, installation from source or +[container image](https://eturnal.net/documentation/code/docker.html). They are +all described [here](https://github.com/processone/eturnal#installation). + +Quick-Test instructions in a [Linux Shell](https://github.com/processone/eturnal/blob/master/QUICK-TEST.md) +or with [Docker](https://github.com/processone/eturnal/blob/master/docker-k8s/QUICK-TEST.md) +are available as well. + +### Configuration + +After installation, `eturnal` usually ships a [default configuration file](https://github.com/processone/eturnal/blob/master/config/eturnal.yml) +here: `/etc/eturnal.yml` (and, if not found there, there is a backup file here: +`/opt/eturnal/etc/eturnal.yml`). It uses the (indentation-sensitive!) [YAML](https://en.wikipedia.org/wiki/YAML) +format. The file contains further explanations. + +Here are some hints how to configure eturnal on your [host machine](https://github.com/processone/eturnal#configuration) +or when using e.g. [Docker](https://eturnal.net/documentation/code/docker.html). +You may also further deep dive into the [reference documentation](https://eturnal.net/documentation/). + +`eturnal` runs out of the box with the default configuration. To enable TURN and +to integrate it with your homeserver, some aspects in `eturnal`'s default configuration file +must be edited: + +1. Homeserver's [`turn_shared_secret`](../../usage/configuration/config_documentation.md#turn_shared_secret) + and eturnal's shared `secret` for authentication + + Both need to have the same value. Uncomment and adjust this line in `eturnal`'s + configuration file: + + ```yaml + secret: "long-and-cryptic" # Shared secret, CHANGE THIS. + ``` + + One way to generate a `secret` is with `pwgen`: + + ```sh + pwgen -s 64 1 + ``` + +1. Public IP address + + If your TURN server is behind NAT, the NAT gateway must have an external, + publicly-reachable IP address. `eturnal` tries to autodetect the public IP address, + however, it may also be configured by uncommenting and adjusting this line, so + `eturnal` advertises that address to connecting clients: + + ```yaml + relay_ipv4_addr: "203.0.113.4" # The server's public IPv4 address. + ``` + + If your NAT gateway is reachable over both IPv4 and IPv6, you may + configure `eturnal` to advertise each available address: + + ```yaml + relay_ipv4_addr: "203.0.113.4" # The server's public IPv4 address. + relay_ipv6_addr: "2001:db8::4" # The server's public IPv6 address (optional). + ``` + + When advertising an external IPv6 address, ensure that the firewall and + network settings of the system running your TURN server are configured to + accept IPv6 traffic, and that the TURN server is listening on the local + IPv6 address that is mapped by NAT to the external IPv6 address. + +1. Logging + + If `eturnal` was started by systemd, log files are written into the + `/var/log/eturnal` directory by default. In order to log to the [journal](https://www.freedesktop.org/software/systemd/man/systemd-journald.service.html) + instead, the `log_dir` option can be set to `stdout` in the configuration file. + +1. Security considerations + + Consider your security settings. TURN lets users request a relay which will + connect to arbitrary IP addresses and ports. The following configuration is + suggested as a minimum starting point, [see also the official documentation](https://eturnal.net/documentation/#blacklist): + + ```yaml + ## Reject TURN relaying from/to the following addresses/networks: + blacklist: # This is the default blacklist. + - "127.0.0.0/8" # IPv4 loopback. + - "::1" # IPv6 loopback. + - recommended # Expands to a number of networks recommended to be + # blocked, but includes private networks. Those + # would have to be 'whitelist'ed if eturnal serves + # local clients/peers within such networks. + ``` + + To whitelist IP addresses or specific (private) networks, you need to **add** a + whitelist part into the configuration file, e.g.: + + ```yaml + whitelist: + - "192.168.0.0/16" + - "203.0.113.113" + - "2001:db8::/64" + ``` + + The more specific, the better. + +1. TURNS (TURN via TLS/DTLS) + + Also consider supporting TLS/DTLS. To do this, adjust the following settings + in the `eturnal.yml` configuration file (TLS parts should not be commented anymore): + + ```yaml + listen: + - ip: "::" + port: 3478 + transport: udp + - ip: "::" + port: 3478 + transport: tcp + - ip: "::" + port: 5349 + transport: tls + + ## TLS certificate/key files (must be readable by 'eturnal' user!): + tls_crt_file: /etc/eturnal/tls/crt.pem + tls_key_file: /etc/eturnal/tls/key.pem + ``` + + In this case, replace the `turn:` schemes in homeserver's `turn_uris` settings + with `turns:`. More is described [here](../../usage/configuration/config_documentation.md#turn_uris). + + We recommend that you only try to set up TLS/DTLS once you have set up a + basic installation and got it working. + + NB: If your TLS certificate was provided by Let's Encrypt, TLS/DTLS will + not work with any Matrix client that uses Chromium's WebRTC library. This + currently includes Element Android & iOS; for more details, see their + [respective](https://github.com/vector-im/element-android/issues/1533) + [issues](https://github.com/vector-im/element-ios/issues/2712) as well as the underlying + [WebRTC issue](https://bugs.chromium.org/p/webrtc/issues/detail?id=11710). + Consider using a ZeroSSL certificate for your TURN server as a working alternative. + +1. Firewall + + Ensure your firewall allows traffic into the TURN server on the ports + you've configured it to listen on (By default: 3478 and 5349 for TURN + traffic (remember to allow both TCP and UDP traffic), and ports 49152-65535 + for the UDP relay.) + +1. Reload/ restarting `eturnal` + + Changes in the configuration file require `eturnal` to reload/ restart, this + can be achieved by: + + ```sh + eturnalctl reload + ``` + + `eturnal` performs a configuration check before actually reloading/ restarting + and provides hints, if something is not correctly configured. + +### eturnalctl opterations script + +`eturnal` offers a handy [operations script](https://eturnal.net/documentation/#Operation) +which can be called e.g. to check, whether the service is up, to restart the service, +to query how many active sessions exist, to change logging behaviour and so on. + +Hint: If `eturnalctl` is not part of your `$PATH`, consider either sym-linking it (e.g. ´ln -s /opt/eturnal/bin/eturnalctl /usr/local/bin/eturnalctl´) or call it from the default `eturnal` directory directly: e.g. `/opt/eturnal/bin/eturnalctl info` diff --git a/docs/turn-howto.md b/docs/turn-howto.md index 37a311ad9c..b466cab40c 100644 --- a/docs/turn-howto.md +++ b/docs/turn-howto.md @@ -9,222 +9,28 @@ allows the homeserver to generate credentials that are valid for use on the TURN server through the use of a secret shared between the homeserver and the TURN server. -The following sections describe how to install [coturn](<https://github.com/coturn/coturn>) (which implements the TURN REST API) and integrate it with synapse. +This documentation provides two TURN server configuration examples: + +* [coturn](setup/turn/coturn.md) +* [eturnal](setup/turn/eturnal.md) ## Requirements -For TURN relaying with `coturn` to work, it must be hosted on a server/endpoint with a public IP. +For TURN relaying to work, the TURN service must be hosted on a server/endpoint with a public IP. Hosting TURN behind NAT requires port forwaring and for the NAT gateway to have a public IP. However, even with appropriate configuration, NAT is known to cause issues and to often not work. -## `coturn` setup - -### Initial installation - -The TURN daemon `coturn` is available from a variety of sources such as native package managers, or installation from source. - -#### Debian installation - -Just install the debian package: - -```sh -apt install coturn -``` - -This will install and start a systemd service called `coturn`. - -#### Source installation - -1. Download the [latest release](https://github.com/coturn/coturn/releases/latest) from github. Unpack it and `cd` into the directory. - -1. Configure it: - - ```sh - ./configure - ``` - - You may need to install `libevent2`: if so, you should do so in - the way recommended by your operating system. You can ignore - warnings about lack of database support: a database is unnecessary - for this purpose. - -1. Build and install it: - - ```sh - make - make install - ``` - -### Configuration - -1. Create or edit the config file in `/etc/turnserver.conf`. The relevant - lines, with example values, are: - - ``` - use-auth-secret - static-auth-secret=[your secret key here] - realm=turn.myserver.org - ``` - - See `turnserver.conf` for explanations of the options. One way to generate - the `static-auth-secret` is with `pwgen`: - - ```sh - pwgen -s 64 1 - ``` - - A `realm` must be specified, but its value is somewhat arbitrary. (It is - sent to clients as part of the authentication flow.) It is conventional to - set it to be your server name. - -1. You will most likely want to configure coturn to write logs somewhere. The - easiest way is normally to send them to the syslog: - - ```sh - syslog - ``` - - (in which case, the logs will be available via `journalctl -u coturn` on a - systemd system). Alternatively, coturn can be configured to write to a - logfile - check the example config file supplied with coturn. - -1. Consider your security settings. TURN lets users request a relay which will - connect to arbitrary IP addresses and ports. The following configuration is - suggested as a minimum starting point: - - ``` - # VoIP traffic is all UDP. There is no reason to let users connect to arbitrary TCP endpoints via the relay. - no-tcp-relay - - # don't let the relay ever try to connect to private IP address ranges within your network (if any) - # given the turn server is likely behind your firewall, remember to include any privileged public IPs too. - denied-peer-ip=10.0.0.0-10.255.255.255 - denied-peer-ip=192.168.0.0-192.168.255.255 - denied-peer-ip=172.16.0.0-172.31.255.255 - - # recommended additional local peers to block, to mitigate external access to internal services. - # https://www.rtcsec.com/article/slack-webrtc-turn-compromise-and-bug-bounty/#how-to-fix-an-open-turn-relay-to-address-this-vulnerability - no-multicast-peers - denied-peer-ip=0.0.0.0-0.255.255.255 - denied-peer-ip=100.64.0.0-100.127.255.255 - denied-peer-ip=127.0.0.0-127.255.255.255 - denied-peer-ip=169.254.0.0-169.254.255.255 - denied-peer-ip=192.0.0.0-192.0.0.255 - denied-peer-ip=192.0.2.0-192.0.2.255 - denied-peer-ip=192.88.99.0-192.88.99.255 - denied-peer-ip=198.18.0.0-198.19.255.255 - denied-peer-ip=198.51.100.0-198.51.100.255 - denied-peer-ip=203.0.113.0-203.0.113.255 - denied-peer-ip=240.0.0.0-255.255.255.255 - - # special case the turn server itself so that client->TURN->TURN->client flows work - # this should be one of the turn server's listening IPs - allowed-peer-ip=10.0.0.1 - - # consider whether you want to limit the quota of relayed streams per user (or total) to avoid risk of DoS. - user-quota=12 # 4 streams per video call, so 12 streams = 3 simultaneous relayed calls per user. - total-quota=1200 - ``` - -1. Also consider supporting TLS/DTLS. To do this, add the following settings - to `turnserver.conf`: - - ``` - # TLS certificates, including intermediate certs. - # For Let's Encrypt certificates, use `fullchain.pem` here. - cert=/path/to/fullchain.pem - - # TLS private key file - pkey=/path/to/privkey.pem - - # Ensure the configuration lines that disable TLS/DTLS are commented-out or removed - #no-tls - #no-dtls - ``` - - In this case, replace the `turn:` schemes in the `turn_uris` settings below - with `turns:`. - - We recommend that you only try to set up TLS/DTLS once you have set up a - basic installation and got it working. - - NB: If your TLS certificate was provided by Let's Encrypt, TLS/DTLS will - not work with any Matrix client that uses Chromium's WebRTC library. This - currently includes Element Android & iOS; for more details, see their - [respective](https://github.com/vector-im/element-android/issues/1533) - [issues](https://github.com/vector-im/element-ios/issues/2712) as well as the underlying - [WebRTC issue](https://bugs.chromium.org/p/webrtc/issues/detail?id=11710). - Consider using a ZeroSSL certificate for your TURN server as a working alternative. - -1. Ensure your firewall allows traffic into the TURN server on the ports - you've configured it to listen on (By default: 3478 and 5349 for TURN - traffic (remember to allow both TCP and UDP traffic), and ports 49152-65535 - for the UDP relay.) - -1. If your TURN server is behind NAT, the NAT gateway must have an external, - publicly-reachable IP address. You must configure coturn to advertise that - address to connecting clients: - - ``` - external-ip=EXTERNAL_NAT_IPv4_ADDRESS - ``` - - You may optionally limit the TURN server to listen only on the local - address that is mapped by NAT to the external address: - - ``` - listening-ip=INTERNAL_TURNSERVER_IPv4_ADDRESS - ``` - - If your NAT gateway is reachable over both IPv4 and IPv6, you may - configure coturn to advertise each available address: - - ``` - external-ip=EXTERNAL_NAT_IPv4_ADDRESS - external-ip=EXTERNAL_NAT_IPv6_ADDRESS - ``` - - When advertising an external IPv6 address, ensure that the firewall and - network settings of the system running your TURN server are configured to - accept IPv6 traffic, and that the TURN server is listening on the local - IPv6 address that is mapped by NAT to the external IPv6 address. - -1. (Re)start the turn server: - - * If you used the Debian package (or have set up a systemd unit yourself): - ```sh - systemctl restart coturn - ``` - - * If you installed from source: - - ```sh - bin/turnserver -o - ``` +Afterwards, the homeserver needs some further configuration. ## Synapse setup Your homeserver configuration file needs the following extra keys: -1. "`turn_uris`": This needs to be a yaml list of public-facing URIs - for your TURN server to be given out to your clients. Add separate - entries for each transport your TURN server supports. -2. "`turn_shared_secret`": This is the secret shared between your - homeserver and your TURN server, so you should set it to the same - string you used in turnserver.conf. -3. "`turn_user_lifetime`": This is the amount of time credentials - generated by your homeserver are valid for (in milliseconds). - Shorter times offer less potential for abuse at the expense of - increased traffic between web clients and your homeserver to - refresh credentials. The TURN REST API specification recommends - one day (86400000). -4. "`turn_allow_guests`": Whether to allow guest users to use the - TURN server. This is enabled by default, as otherwise VoIP will - not work reliably for guests. However, it does introduce a - security risk as it lets guests connect to arbitrary endpoints - without having gone through a CAPTCHA or similar to register a - real account. +1. [`turn_uris`](usage/configuration/config_documentation.md#turn_uris) +2. [`turn_shared_secret`](usage/configuration/config_documentation.md#turn_shared_secret) +3. [`turn_user_lifetime`](usage/configuration/config_documentation.md#turn_user_lifetime) +4. [`turn_allow_guests`](usage/configuration/config_documentation.md#turn_allow_guests) As an example, here is the relevant section of the config file for `matrix.org`. The `turn_uris` are appropriate for TURN servers listening on the default ports, with no TLS. @@ -263,7 +69,7 @@ Here are a few things to try: * Check that you have opened your firewall to allow UDP traffic to the UDP relay ports (49152-65535 by default). - * Try disabling `coturn`'s TLS/DTLS listeners and enable only its (unencrypted) + * Try disabling TLS/DTLS listeners and enable only its (unencrypted) TCP/UDP listeners. (This will only leave signaling traffic unencrypted; voice & video WebRTC traffic is always encrypted.) @@ -288,12 +94,19 @@ Here are a few things to try: * ensure that your TURN server uses the NAT gateway as its default route. - * Enable more verbose logging in coturn via the `verbose` setting: + * Enable more verbose logging, in `coturn` via the `verbose` setting: ``` verbose ``` + or with `eturnal` with the shell command `eturnalctl loglevel debug` or in the configuration file (the service needs to [reload](https://eturnal.net/documentation/#Operation) for it to become effective): + + ```yaml + ## Logging configuration: + log_level: debug + ``` + ... and then see if there are any clues in its logs. * If you are using a browser-based client under Chrome, check @@ -317,7 +130,7 @@ Here are a few things to try: matrix client to your homeserver in your browser's network inspector. In the response you should see `username` and `password`. Or: - * Use the following shell commands: + * Use the following shell commands for `coturn`: ```sh secret=staticAuthSecretHere @@ -327,11 +140,16 @@ Here are a few things to try: echo -e "username: $u\npassword: $p" ``` - Or: + or for `eturnal` + + ```sh + eturnalctl credentials + ``` + - * Temporarily configure coturn to accept a static username/password. To do - this, comment out `use-auth-secret` and `static-auth-secret` and add the - following: + * Or (**coturn only**): Temporarily configure `coturn` to accept a static + username/password. To do this, comment out `use-auth-secret` and + `static-auth-secret` and add the following: ``` lt-cred-mech |