Merge pull request #1083 from matrix-org/erikj/check_origin

Check the user_id for presence/typing matches origin

synapse/handlers/presence.py

@@ -651,6 +651,13 @@ class PresenceHandler(object):
                 )
                 continue
 
+            if get_domain_from_id(user_id) != origin:
+                logger.info(
+                    "Got presence update from %r with bad 'user_id': %r",
+                    origin, user_id,
+                )
+                continue
+
             presence_state = push.get("presence", None)
             if not presence_state:
                 logger.info(

synapse/handlers/typing.py

@@ -199,7 +199,14 @@ class TypingHandler(object):
         user_id = content["user_id"]
 
         # Check that the string is a valid user id
-        UserID.from_string(user_id)
+        user = UserID.from_string(user_id)
+
+        if user.domain != origin:
+            logger.info(
+                "Got typing update from %r with bad 'user_id': %r",
+                origin, user_id,
+            )
+            return
 
         users = yield self.state.get_current_user_in_room(room_id)
         domains = set(get_domain_from_id(u) for u in users)