Merge branch 'develop' of github.com:matrix-org/synapse into erikj/redactions_eiah

1 files changed, 11 insertions, 5 deletions

diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index 6681614232..aeadc9c564 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -25,7 +25,7 @@ from twisted.internet import defer
 from twisted.internet.abstract import isIPAddress
 from twisted.python import failure
 
-from synapse.api.constants import EventTypes
+from synapse.api.constants import EventTypes, Membership
 from synapse.api.errors import (
     AuthError,
     FederationError,
@@ -620,16 +620,19 @@ class FederationServer(FederationBase):
         """
         # check that it's actually being sent from a valid destination to
         # workaround bug #1753 in 0.18.5 and 0.18.6
-        if origin != get_domain_from_id(pdu.event_id):
+        if origin != get_domain_from_id(pdu.sender):
             # We continue to accept join events from any server; this is
             # necessary for the federation join dance to work correctly.
             # (When we join over federation, the "helper" server is
             # responsible for sending out the join event, rather than the
-            # origin. See bug #1893).
+            # origin. See bug #1893. This is also true for some third party
+            # invites).
             if not (
                 pdu.type == 'm.room.member' and
                 pdu.content and
-                pdu.content.get("membership", None) == 'join'
+                pdu.content.get("membership", None) in (
+                    Membership.JOIN, Membership.INVITE,
+                )
             ):
                 logger.info(
                     "Discarding PDU %s from invalid origin %s",
@@ -642,9 +645,12 @@ class FederationServer(FederationBase):
                     pdu.event_id, origin
                 )
 
+        # We've already checked that we know the room version by this point
+        room_version = yield self.store.get_room_version(pdu.room_id)
+
         # Check signature.
         try:
-            pdu = yield self._check_sigs_and_hash(pdu)
+            pdu = yield self._check_sigs_and_hash(room_version, pdu)
         except SynapseError as e:
             raise FederationError(
                 "ERROR",