Merge pull request #1136 from matrix-org/erikj/fix_signed_3pid

Allow invites via 3pid to bypass sender sig check

1 files changed, 9 insertions, 6 deletions

diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index f7cb3c1bb2..2d801bad47 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -1922,15 +1922,18 @@ class FederationHandler(BaseHandler):
             original_invite = yield self.store.get_event(
                 original_invite_id, allow_none=True
             )
-        if not original_invite:
+        if original_invite:
+            display_name = original_invite.content["display_name"]
+            event_dict["content"]["third_party_invite"]["display_name"] = display_name
+        else:
             logger.info(
-                "Could not find invite event for third_party_invite - "
-                "discarding: %s" % (event_dict,)
+                "Could not find invite event for third_party_invite: %r",
+                event_dict
             )
-            return
+            # We don't discard here as this is not the appropriate place to do
+            # auth checks. If we need the invite and don't have it then the
+            # auth check code will explode appropriately.
 
-        display_name = original_invite.content["display_name"]
-        event_dict["content"]["third_party_invite"]["display_name"] = display_name
         builder = self.event_builder_factory.new(event_dict)
         EventValidator().validate_new(builder)
         message_handler = self.hs.get_handlers().message_handler