Exchange 3pid invites for m.room.member invites

synapse/api/auth.py

@@ -24,7 +24,6 @@
 from synapse.api.errors import AuthError, Codes, SynapseError, EventSizeError
 from synapse.types import RoomID, UserID, EventID
 from synapse.util.logutils import log_function
-from synapse.util import third_party_invites
 from unpaddedbase64 import decode_base64
 
 import logging
@@ -318,6 +317,11 @@ def is_membership_change_allowed(self, event, auth_events):
             }
         )
 
+        if Membership.INVITE == membership and "third_party_invite" in event.content:
+            if not self._verify_third_party_invite(event, auth_events):
+                raise AuthError(403, "You are not invited to this room.")
+            return True
+
         if Membership.JOIN != membership:
             if (caller_invited
                     and Membership.LEAVE == membership
@@ -361,8 +365,7 @@ def is_membership_change_allowed(self, event, auth_events):
                 pass
             elif join_rule == JoinRules.INVITE:
                 if not caller_in_room and not caller_invited:
-                    if not self._verify_third_party_invite(event, auth_events):
-                        raise AuthError(403, "You are not invited to this room.")
+                    raise AuthError(403, "You are not invited to this room.")
             else:
                 # TODO (erikj): may_join list
                 # TODO (erikj): private rooms
@@ -390,10 +393,10 @@ def is_membership_change_allowed(self, event, auth_events):
 
     def _verify_third_party_invite(self, event, auth_events):
         """
-        Validates that the join event is authorized by a previous third-party invite.
+        Validates that the invite event is authorized by a previous third-party invite.
 
-        Checks that the public key, and keyserver, match those in the invite,
-        and that the join event has a signature issued using that public key.
+        Checks that the public key, and keyserver, match those in the third party invite,
+        and that the invite event has a signature issued using that public key.
 
         Args:
             event: The m.room.member join event being validated.
@@ -404,35 +407,28 @@ def _verify_third_party_invite(self, event, auth_events):
             True if the event fulfills the expectations of a previous third party
             invite event.
         """
-        if not third_party_invites.join_has_third_party_invite(event.content):
+        if "third_party_invite" not in event.content:
+            return False
+        if "signed" not in event.content["third_party_invite"]:
             return False
-        join_third_party_invite = event.content["third_party_invite"]
-        token = join_third_party_invite["token"]
+        signed = event.content["third_party_invite"]["signed"]
+        for key in {"mxid", "token"}:
+            if key not in signed:
+                return False
+
+        token = signed["token"]
+
         invite_event = auth_events.get(
             (EventTypes.ThirdPartyInvite, token,)
         )
         if not invite_event:
-            logger.info("Failing 3pid invite because no invite found for token %s", token)
+            return False
+
+        if event.user_id != invite_event.user_id:
             return False
         try:
-            public_key = join_third_party_invite["public_key"]
-            key_validity_url = join_third_party_invite["key_validity_url"]
-            if invite_event.content["public_key"] != public_key:
-                logger.info(
-                    "Failing 3pid invite because public key invite: %s != join: %s",
-                    invite_event.content["public_key"],
-                    public_key
-                )
-                return False
-            if invite_event.content["key_validity_url"] != key_validity_url:
-                logger.info(
-                    "Failing 3pid invite because key_validity_url invite: %s != join: %s",
-                    invite_event.content["key_validity_url"],
-                    key_validity_url
-                )
-                return False
-            signed = join_third_party_invite["signed"]
-            if signed["mxid"] != event.user_id:
+            public_key = invite_event.content["public_key"]
+            if signed["mxid"] != event.state_key:
                 return False
             if signed["token"] != token:
                 return False
@@ -445,6 +441,11 @@ def _verify_third_party_invite(self, event, auth_events):
                         decode_base64(public_key)
                     )
                     verify_signed_json(signed, server, verify_key)
+
+                    # We got the public key from the invite, so we know that the
+                    # correct server signed the signed bundle.
+                    # The caller is responsible for checking that the signing
+                    # server has not revoked that public key.
                     return True
             return False
         except (KeyError, SignatureVerifyException,):
@@ -751,17 +752,19 @@ def compute_auth_events(self, event, current_state):
             if e_type == Membership.JOIN:
                 if member_event and not is_public:
                     auth_ids.append(member_event.event_id)
-                if third_party_invites.join_has_third_party_invite(event.content):
+            else:
+                if member_event:
+                    auth_ids.append(member_event.event_id)
+
+            if e_type == Membership.INVITE:
+                if "third_party_invite" in event.content:
                     key = (
                         EventTypes.ThirdPartyInvite,
                         event.content["third_party_invite"]["token"]
                     )
-                    invite = current_state.get(key)
-                    if invite:
-                        auth_ids.append(invite.event_id)
-            else:
-                if member_event:
-                    auth_ids.append(member_event.event_id)
+                    third_party_invite = current_state.get(key)
+                    if third_party_invite:
+                        auth_ids.append(third_party_invite.event_id)
         elif member_event:
             if member_event.content["membership"] == Membership.JOIN:
                 auth_ids.append(member_event.event_id)

synapse/federation/federation_client.py

@@ -26,7 +26,6 @@
 from synapse.util import unwrapFirstError
 from synapse.util.caches.expiringcache import ExpiringCache
 from synapse.util.logutils import log_function
-from synapse.util import third_party_invites
 from synapse.events import FrozenEvent
 import synapse.metrics
 
@@ -358,7 +357,7 @@ def get_event_auth(self, destination, room_id, event_id):
         defer.returnValue(signed_auth)
 
     @defer.inlineCallbacks
-    def make_membership_event(self, destinations, room_id, user_id, membership, content):
+    def make_membership_event(self, destinations, room_id, user_id, membership):
         """
         Creates an m.room.member event, with context, without participating in the room.
 
@@ -390,14 +389,9 @@ def make_membership_event(self, destinations, room_id, user_id, membership, cont
             if destination == self.server_name:
                 continue
 
-            args = {}
-            if third_party_invites.join_has_third_party_invite(content):
-                args = third_party_invites.extract_join_keys(
-                    content["third_party_invite"]
-                )
             try:
                 ret = yield self.transport_layer.make_membership_event(
-                    destination, room_id, user_id, membership, args
+                    destination, room_id, user_id, membership
                 )
 
                 pdu_dict = ret["event"]
@@ -704,3 +698,26 @@ def event_from_pdu_json(self, pdu_json, outlier=False):
         event.internal_metadata.outlier = outlier
 
         return event
+
+    @defer.inlineCallbacks
+    def forward_third_party_invite(self, destinations, room_id, event_dict):
+        for destination in destinations:
+            if destination == self.server_name:
+                continue
+
+            try:
+                yield self.transport_layer.exchange_third_party_invite(
+                    destination=destination,
+                    room_id=room_id,
+                    event_dict=event_dict,
+                )
+                defer.returnValue(None)
+            except CodeMessageException:
+                raise
+            except Exception as e:
+                logger.exception(
+                    "Failed to send_third_party_invite via %s: %s",
+                    destination, e.message
+                )
+
+        raise RuntimeError("Failed to send to any server.")

synapse/federation/federation_server.py

@@ -23,12 +23,10 @@
 from synapse.events import FrozenEvent
 import synapse.metrics
 
-from synapse.api.errors import FederationError, SynapseError, Codes
+from synapse.api.errors import FederationError, SynapseError
 
 from synapse.crypto.event_signing import compute_event_signature
 
-from synapse.util import third_party_invites
-
 import simplejson as json
 import logging
 
@@ -230,19 +228,8 @@ def on_query_request(self, query_type, args):
             )
 
     @defer.inlineCallbacks
-    def on_make_join_request(self, room_id, user_id, query):
-        threepid_details = {}
-        if third_party_invites.has_join_keys(query):
-            for k in third_party_invites.JOIN_KEYS:
-                if not isinstance(query[k], list) or len(query[k]) != 1:
-                    raise FederationError(
-                        "FATAL",
-                        Codes.MISSING_PARAM,
-                        "key %s value %s" % (k, query[k],),
-                        None
-                    )
-                threepid_details[k] = query[k][0]
-        pdu = yield self.handler.on_make_join_request(room_id, user_id, threepid_details)
+    def on_make_join_request(self, room_id, user_id):
+        pdu = yield self.handler.on_make_join_request(room_id, user_id)
         time_now = self._clock.time_msec()
         defer.returnValue({"event": pdu.get_pdu_json(time_now)})
 
@@ -556,3 +543,15 @@ def event_from_pdu_json(self, pdu_json, outlier=False):
         event.internal_metadata.outlier = outlier
 
         return event
+
+    @defer.inlineCallbacks
+    def exchange_third_party_invite(self, invite):
+        ret = yield self.handler.exchange_third_party_invite(invite)
+        defer.returnValue(ret)
+
+    @defer.inlineCallbacks
+    def on_exchange_third_party_invite_request(self, origin, room_id, event_dict):
+        ret = yield self.handler.on_exchange_third_party_invite_request(
+            origin, room_id, event_dict
+        )
+        defer.returnValue(ret)

synapse/federation/transport/client.py

@@ -161,7 +161,7 @@ def make_query(self, destination, query_type, args, retry_on_dns_fail):
 
     @defer.inlineCallbacks
     @log_function
-    def make_membership_event(self, destination, room_id, user_id, membership, args={}):
+    def make_membership_event(self, destination, room_id, user_id, membership):
         valid_memberships = {Membership.JOIN, Membership.LEAVE}
         if membership not in valid_memberships:
             raise RuntimeError(
@@ -173,7 +173,6 @@ def make_membership_event(self, destination, room_id, user_id, membership, args=
         content = yield self.client.get_json(
             destination=destination,
             path=path,
-            args=args,
             retry_on_dns_fail=True,
         )
 
@@ -218,6 +217,19 @@ def send_invite(self, destination, room_id, event_id, content):
 
         defer.returnValue(response)
 
+    @defer.inlineCallbacks
+    @log_function
+    def exchange_third_party_invite(self, destination, room_id, event_dict):
+        path = PREFIX + "/exchange_third_party_invite/%s" % (room_id,)
+
+        response = yield self.client.put_json(
+            destination=destination,
+            path=path,
+            data=event_dict,
+        )
+
+        defer.returnValue(response)
+
     @defer.inlineCallbacks
     @log_function
     def get_event_auth(self, destination, room_id, event_id):

synapse/federation/transport/server.py

@@ -292,7 +292,7 @@ class FederationMakeJoinServlet(BaseFederationServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, origin, content, query, context, user_id):
-        content = yield self.handler.on_make_join_request(context, user_id, query)
+        content = yield self.handler.on_make_join_request(context, user_id)
         defer.returnValue((200, content))
 
 
@@ -343,6 +343,17 @@ def on_PUT(self, origin, content, query, context, event_id):
         defer.returnValue((200, content))
 
 
+class FederationThirdPartyInviteExchangeServlet(BaseFederationServlet):
+    PATH = "/exchange_third_party_invite/([^/]*)"
+
+    @defer.inlineCallbacks
+    def on_PUT(self, origin, content, query, room_id):
+        content = yield self.handler.on_exchange_third_party_invite_request(
+            origin, room_id, content
+        )
+        defer.returnValue((200, content))
+
+
 class FederationClientKeysQueryServlet(BaseFederationServlet):
     PATH = "/user/keys/query"
 
@@ -396,6 +407,30 @@ def on_POST(self, origin, content, query, room_id):
         defer.returnValue((200, content))
 
 
+class On3pidBindServlet(BaseFederationServlet):
+    PATH = "/3pid/onbind"
+
+    @defer.inlineCallbacks
+    def on_POST(self, request):
+        content_bytes = request.content.read()
+        content = json.loads(content_bytes)
+        if "invites" in content:
+            last_exception = None
+            for invite in content["invites"]:
+                try:
+                    yield self.handler.exchange_third_party_invite(invite)
+                except Exception as e:
+                    last_exception = e
+            if last_exception:
+                raise last_exception
+        defer.returnValue((200, {}))
+
+    # Avoid doing remote HS authorization checks which are done by default by
+    # BaseFederationServlet.
+    def _wrap(self, code):
+        return code
+
+
 SERVLET_CLASSES = (
     FederationPullServlet,
     FederationEventServlet,
@@ -413,4 +448,6 @@ def on_POST(self, origin, content, query, room_id):
     FederationEventAuthServlet,
     FederationClientKeysQueryServlet,
     FederationClientKeysClaimServlet,
+    FederationThirdPartyInviteExchangeServlet,
+    On3pidBindServlet,
 )

synapse/handlers/_base.py

@@ -21,7 +21,6 @@
 from synapse.types import UserID, RoomAlias
 
 from synapse.util.logcontext import PreserveLoggingContext
-from synapse.util import third_party_invites
 
 import logging
 
@@ -192,16 +191,6 @@ def handle_new_client_event(self, event, context, extra_destinations=[],
                         )
                     )
 
-        if (
-            event.type == EventTypes.Member and
-            event.content["membership"] == Membership.JOIN and
-            third_party_invites.join_has_third_party_invite(event.content)
-        ):
-            yield third_party_invites.check_key_valid(
-                self.hs.get_simple_http_client(),
-                event
-            )
-
         federation_handler = self.hs.get_handlers().federation_handler
 
         if event.type == EventTypes.Member: