1 files changed, 73 insertions, 0 deletions
diff --git a/synapse/rest/client/voip.py b/synapse/rest/client/voip.py
new file mode 100644
index 0000000000..f53020520d
--- /dev/null
+++ b/synapse/rest/client/voip.py
@@ -0,0 +1,73 @@
+# Copyright 2014-2016 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import base64
+import hashlib
+import hmac
+
+from synapse.http.servlet import RestServlet
+from synapse.rest.client._base import client_patterns
+
+
+class VoipRestServlet(RestServlet):
+    PATTERNS = client_patterns("/voip/turnServer$", v1=True)
+
+    def __init__(self, hs):
+        super().__init__()
+        self.hs = hs
+        self.auth = hs.get_auth()
+
+    async def on_GET(self, request):
+        requester = await self.auth.get_user_by_req(
+            request, self.hs.config.turn_allow_guests
+        )
+
+        turnUris = self.hs.config.turn_uris
+        turnSecret = self.hs.config.turn_shared_secret
+        turnUsername = self.hs.config.turn_username
+        turnPassword = self.hs.config.turn_password
+        userLifetime = self.hs.config.turn_user_lifetime
+
+        if turnUris and turnSecret and userLifetime:
+            expiry = (self.hs.get_clock().time_msec() + userLifetime) / 1000
+            username = "%d:%s" % (expiry, requester.user.to_string())
+
+            mac = hmac.new(
+                turnSecret.encode(), msg=username.encode(), digestmod=hashlib.sha1
+            )
+            # We need to use standard padded base64 encoding here
+            # encode_base64 because we need to add the standard padding to get the
+            # same result as the TURN server.
+            password = base64.b64encode(mac.digest()).decode("ascii")
+
+        elif turnUris and turnUsername and turnPassword and userLifetime:
+            username = turnUsername
+            password = turnPassword
+
+        else:
+            return 200, {}
+
+        return (
+            200,
+            {
+                "username": username,
+                "password": password,
+                "ttl": userLifetime / 1000,
+                "uris": turnUris,
+            },
+        )
+
+
+def register_servlets(hs, http_server):
+    VoipRestServlet(hs).register(http_server)