diff options
| -rw-r--r-- | changelog.d/7817.bugfix | 1 | ||||
| -rw-r--r-- | synapse/event_auth.py | 10 | ||||
| -rw-r--r-- | synapse/handlers/federation.py | 49 |
3 files changed, 44 insertions, 16 deletions
diff --git a/changelog.d/7817.bugfix b/changelog.d/7817.bugfix new file mode 100644 index 0000000000..1c001070d5 --- /dev/null +++ b/changelog.d/7817.bugfix @@ -0,0 +1 @@ +Fix bug where Synapse fails to process an incoming event over federation if the server is missing too much of the event's auth chain. diff --git a/synapse/event_auth.py b/synapse/event_auth.py index c582355146..c0981eee62 100644 --- a/synapse/event_auth.py +++ b/synapse/event_auth.py @@ -65,14 +65,16 @@ def check( room_id = event.room_id - # I'm not really expecting to get auth events in the wrong room, but let's - # sanity-check it + # We need to ensure that the auth events are actually for the same room, to + # stop people from using powers they've been granted in other rooms for + # example. for auth_event in auth_events.values(): if auth_event.room_id != room_id: - raise Exception( + raise AuthError( + 403, "During auth for event %s in room %s, found event %s in the state " "which is in room %s" - % (event.event_id, room_id, auth_event.event_id, auth_event.room_id) + % (event.event_id, room_id, auth_event.event_id, auth_event.room_id), ) if do_sig_check: diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py index ca7da42a3f..930ae088c6 100644 --- a/synapse/handlers/federation.py +++ b/synapse/handlers/federation.py @@ -618,6 +618,11 @@ class FederationHandler(BaseHandler): will be omitted from the result. Likewise, any events which turn out not to be in the given room. + This function *does not* automatically get missing auth events of the + newly fetched events. Callers must include the full auth chain of + of the missing events in the `event_ids` argument, to ensure that any + missing auth events are correctly fetched. + Returns: map from event_id to event """ @@ -1131,12 +1136,16 @@ class FederationHandler(BaseHandler): ): """Fetch the given events from a server, and persist them as outliers. + This function *does not* recursively get missing auth events of the + newly fetched events. Callers must include in the `events` argument + any missing events from the auth chain. + Logs a warning if we can't find the given event. """ room_version = await self.store.get_room_version(room_id) - event_infos = [] + event_map = {} # type: Dict[str, EventBase] async def get_event(event_id: str): with nested_logging_context(event_id): @@ -1150,17 +1159,7 @@ class FederationHandler(BaseHandler): ) return - # recursively fetch the auth events for this event - auth_events = await self._get_events_from_store_or_dest( - destination, room_id, event.auth_event_ids() - ) - auth = {} - for auth_event_id in event.auth_event_ids(): - ae = auth_events.get(auth_event_id) - if ae: - auth[(ae.type, ae.state_key)] = ae - - event_infos.append(_NewEventInfo(event, None, auth)) + event_map[event.event_id] = event except Exception as e: logger.warning( @@ -1172,6 +1171,32 @@ class FederationHandler(BaseHandler): await concurrently_execute(get_event, events, 5) + # Make a map of auth events for each event. We do this after fetching + # all the events as some of the events' auth events will be in the list + # of requested events. + + auth_events = [ + aid + for event in event_map.values() + for aid in event.auth_event_ids() + if aid not in event_map + ] + persisted_events = await self.store.get_events( + auth_events, allow_rejected=True, + ) + + event_infos = [] + for event in event_map.values(): + auth = {} + for auth_event_id in event.auth_event_ids(): + ae = persisted_events.get(auth_event_id) or event_map.get(auth_event_id) + if ae: + auth[(ae.type, ae.state_key)] = ae + else: + logger.info("Missing auth event %s", auth_event_id) + + event_infos.append(_NewEventInfo(event, None, auth)) + await self._handle_new_events( destination, event_infos, ) |