matrix: Add coturn support for calls

configuration/default.nix

@@ -1,4 +1,5 @@
 {
+  config,
   pkgs,
   lib,
   modulesPath,
@@ -50,7 +51,8 @@
     useDHCP = false;
     interfaces.eth0.useDHCP = true;
 
-    firewall.allowedTCPPorts = [
+    firewall = {
+      allowedTCPPorts = [
         # http
         80
         443
@@ -60,7 +62,23 @@
         8448
         # starbound
         21025
+
+        config.services.coturn.listening-port
+        config.services.coturn.tls-listening-port
       ];
+
+      allowedUDPPorts = [
+        config.services.coturn.listening-port
+        config.services.coturn.tls-listening-port
+      ];
+
+      allowedUDPPortRanges = [
+        {
+          from = config.services.coturn.min-port;
+          to = config.services.coturn.max-port;
+        }
+      ];
+    };
   };
 
   time.timeZone = "Europe/London";

configuration/services/conduit.nix

@@ -1,6 +1,7 @@
 {config, ...}: let
   cfg = config.services.matrix-conduit;
   domain = "matrix.${config.services.nginx.domain}";
+  turn-realm = "turn.${config.services.nginx.domain}";
 in {
   services.matrix-conduit = {
     enable = true;
@@ -8,9 +9,77 @@ in {
       address = "127.0.0.1";
       server_name = domain;
       database_backend = "rocksdb";
+
+      turn_uris = let
+        address = "${config.services.coturn.realm}:${toString config.services.coturn.listening-port}";
+        tls-address = "${config.services.coturn.realm}:${toString config.services.coturn.tls-listening-port}";
+      in [
+        "turn:${address}?transport=udp"
+        "turn:${address}?transport=tcp"
+        "turns:${tls-address}?transport=udp"
+        "turns:${tls-address}?transport=tcp"
+      ];
     };
   };
 
+  # Pass in the TURN secret via EnvironmentFile, not supported by
+  # upstream module currently.
+  #
+  # See also https://gitlab.com/famedly/conduit/-/issues/314
+  systemd.services.conduit.serviceConfig.EnvironmentFile = config.sops.secrets."turn/env".path;
+
+  services.coturn = {
+    enable = true;
+    use-auth-secret = true;
+    static-auth-secret-file = config.sops.secrets."turn/secret".path;
+    realm = turn-realm;
+    relay-ips = [
+      "178.79.137.55"
+    ];
+
+    # Based on suggestions from
+    # https://github.com/matrix-org/synapse/blob/develop/docs/turn-howto.md
+    # and
+    # https://www.foxypossibilities.com/2018/05/19/setting-up-a-turn-sever-for-matrix-on-nixos/
+    no-tcp-relay = true;
+    secure-stun = true;
+    extraConfig = ''
+      # Deny various local IP ranges, see
+      # https://www.rtcsec.com/article/cve-2020-26262-bypass-of-coturns-access-control-protection/
+      no-multicast-peers
+      denied-peer-ip=0.0.0.0-0.255.255.255
+      denied-peer-ip=10.0.0.0-10.255.255.255
+      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=172.16.0.0-172.31.255.255
+      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=192.168.0.0-192.168.255.255
+      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 denied-peer-ip=::1
+      denied-peer-ip=64:ff9b::-64:ff9b::ffff:ffff
+      denied-peer-ip=::ffff:0.0.0.0-::ffff:255.255.255.255
+      denied-peer-ip=100::-100::ffff:ffff:ffff:ffff
+      denied-peer-ip=2001::-2001:1ff:ffff:ffff:ffff:ffff:ffff:ffff
+      denied-peer-ip=2002::-2002:ffff:ffff:ffff:ffff:ffff:ffff:ffff
+      denied-peer-ip=fc00::-fdff:ffff:ffff:ffff:ffff:ffff:ffff:ffff
+      denied-peer-ip=fe80::-febf:ffff:ffff:ffff:ffff:ffff:ffff:ffff
+      allowed-peer-ip=178.79.137.55
+
+      # Limit number of rooms
+      user-quota=12
+      total-quota=36
+
+      # Various other security settings
+      no-tlsv1
+      no-tlsv1_1
+    '';
+  };
+
   services.nginx.virtualHosts."${domain}" = {
     enableACME = true;
 

configuration/sops.nix

@@ -6,5 +6,9 @@
       group = "nextcloud";
     };
     secrets."steam/tlater" = {};
+    secrets."turn/env" = {};
+    secrets."turn/secret" = {
+      owner = "turnserver";
+    };
   };
 }

keys/production.yaml

@@ -2,14 +2,17 @@ nextcloud:
     tlater: ENC[AES256_GCM,data:zNsPm4uFaIRe3LjcwmayRg==,iv:5wam6bP5zP708jC9UrLV0s8qspl3Pm4fPzbMFYBUyPQ=,tag:apnJUMeJwMn9q0NhO4ptmA==,type:str]
 steam:
     tlater: ENC[AES256_GCM,data:HNsve/Wid40ftclO9n09yXg=,iv:VQxAz4eR9lfxEvM0zl1FpJpbKrEFxjIYLyCqL9Aool0=,tag:LHcpHCXAHe8p2kOvOnKXyw==,type:str]
+turn:
+    env: ENC[AES256_GCM,data:kt5nhVo9pb/ZbPUEcqSYXxN9YMgQKnFb5VRfFFS/qoIaJ73uD2fuJKqcxAyVRrdLqnSAWSQBgTgunBzdP7xqLAK2qt8DYAQWHkIe9uxFbSXZpdmw,iv:9lq6SFwTFN4GGm6gPiJpUMasMdnHVF6XLGYrsyG3kjU=,tag:428Qf9DOiiHt/Wjb188b8g==,type:str]
+    secret: ENC[AES256_GCM,data:si7ee6Xfhdgdyzbp6aQpF7pz3TmTBb7iQ82lRPVXNDg9JfHI+lbmgAsSnRLX5qMCA6P9R045sSMosqidL8QwRg==,iv:SrhpZKK8D45yxCEfDb9P3TwtA14+qEI+wcRqcN/a6pw=,tag:PiwV+mOL9xHJgJft6sc61g==,type:str]
 sops:
     kms: []
     gcp_kms: []
     azure_kv: []
     hc_vault: []
     age: []
-    lastmodified: "2022-10-12T13:13:37Z"
+    lastmodified: "2022-10-28T22:53:26Z"
-    mac: ENC[AES256_GCM,data:+EuA0rblxZYk+0tZs3vUFtr1cVKhdrLi4Ww0QjeITZn2k+SL8Y2gRl3gNVQOe00WHUgSKN53QKhxDj4q6Rd0LfwASxRRjz78Mk8yHDRDIfdDS960EasgKON4HPW/eMd2Fp4+flv57KYywQQWp3AlD8JqxIf5wNhyywn5LlW3PCQ=,iv:YFIk0LrRjV8417QJ5cp5EuIm7bezyG8ZulKcu1xhIF4=,tag:vtq5hCuLEXOvRjE2D/5cCQ==,type:str]
+    mac: ENC[AES256_GCM,data:fNcL/hQUsjSDULz9hOrr8268wNfRzARvuD+QQoUjhj5oDN3/zq800FjHrMBygTr962ueYdpfF7rW3exJqsf0TRVxlrSfvIX0U6Hwgpx7Ts6vMAmJeYdr28EuvbITuq9k14jhJrWmcqHOplJFSE1SoBedxF9LLor5gsc8WZDuBm8=,iv:d3roSZ//iosFzLj6dDWQl35Ya0Vlu2M9bAsWVWorBjI=,tag:8sX4R0WRoifYMJXiamSm9w==,type:str]
     pgp:
         - created_at: "2022-10-12T00:46:51Z"
           enc: |
@@ -47,4 +50,4 @@ sops:
             -----END PGP MESSAGE-----
           fp: 8a3737d48f1035fe6c3a0a8fd6a1976ca74c7f3b
     unencrypted_suffix: _unencrypted
-    version: 3.7.2
+    version: 3.7.3

keys/staging.yaml

@@ -2,14 +2,17 @@ nextcloud:
     tlater: ENC[AES256_GCM,data:91kDcO4hpng=,iv:ayuILRmRru4ZxTCur9H2xHuLjkDzwPdS/4lEog/tesU=,tag:qYhJxnNDcCwUM7xe7Tlcjw==,type:str]
 steam:
     tlater: ENC[AES256_GCM,data:jcW4wacGzOQ=,iv:KstKGHflscSWDFXGbnAZUcsqGN4Ot+w7sRbsAUwZNHQ=,tag:n9sRWvaKSgagpIgV/NF/Og==,type:str]
+turn:
+    env: ENC[AES256_GCM,data:xjIz/AY109lyiL5N01p5T3HcYco/rM5CJSRTtg==,iv:16bW6OpyOK/QL0QPGQp/Baa9xyT8E3ZsYkwqmjuofk0=,tag:J5re3uKxIykw3YunvQWBgg==,type:str]
+    secret: ENC[AES256_GCM,data:eQ7dAocoZtg=,iv:fgzjTPv30WqTKlLy+yMn5MsKQgjhPnwlGFFwYEg3gWs=,tag:1ze33U1NBkgMX/9SiaBNQg==,type:str]
 sops:
     kms: []
     gcp_kms: []
     azure_kv: []
     hc_vault: []
     age: []
-    lastmodified: "2022-10-12T13:14:20Z"
+    lastmodified: "2022-10-28T22:54:01Z"
-    mac: ENC[AES256_GCM,data:IlU8Jr+HD/ZHHsd7eaaSGp3tRxGy8/yhbSejkWmHFeL1WsvdWsToHM7yah2WzX+uY7s/i7atHQdhbHITCi6gBIFociVVPwziK5YOmTXv1fHlcD60U4ClRbTtgMVMtvc5tXrxdLQGhaX+DJ5xXBhTlCSwwqgYP0I7vJmEUF9mz7g=,iv:IM1ebqQB1UO5EN92kipHL20iGtFTKJhUiN/XR6psWBM=,tag:WweauZ5pA7/YMuUuq8C/xQ==,type:str]
+    mac: ENC[AES256_GCM,data:1nsv+Dl7lzRZNNb9kSuqFrXrcncIklw/A2uwd/yQQ546Rm/4gzpBZqCi6cv5VBCdc1iNuBcAM74DnZHMDmeWAiW0WfACPJMQjCes21P6IUsP2gu+bV2f9qqqnP2a5voxzFHp1aclklzMiiZJBEB1Y3UNz0ZG7A43hsOAE0/fJ9o=,iv:kY10PF5ErkKHXx8m0OyX2eU6kcFQsrsP3V2scVBMsuA=,tag:Uth0XfP2c0LBJQ7+7Uc0BQ==,type:str]
     pgp:
         - created_at: "2022-10-12T16:48:23Z"
           enc: |
@@ -47,4 +50,4 @@ sops:
             -----END PGP MESSAGE-----
           fp: 7762ec55a5727cabada621d961e53f94caa314e4
     unencrypted_suffix: _unencrypted
-    version: 3.7.2
+    version: 3.7.3