diff options
Diffstat (limited to 'synapse')
| -rw-r--r-- | synapse/storage/events_worker.py | 64 |
1 files changed, 37 insertions, 27 deletions
diff --git a/synapse/storage/events_worker.py b/synapse/storage/events_worker.py index e2fc7bc047..1d969d70be 100644 --- a/synapse/storage/events_worker.py +++ b/synapse/storage/events_worker.py @@ -236,38 +236,48 @@ class EventsWorkerStore(SQLBaseStore): "allow_rejected=False" ) - # Starting in room version v3, some redactions need to be rechecked if we - # didn't have the redacted event at the time, so we recheck on read - # instead. + # We may not have had the original event when we received a redaction, so + # we have to recheck auth now. + if not allow_rejected and entry.event.type == EventTypes.Redaction: - if entry.event.internal_metadata.need_to_check_redaction(): - # XXX: we should probably use _get_events_from_cache_or_db here, - # so that we can benefit from caching. - orig_sender = yield self._simple_select_one_onecol( - table="events", - keyvalues={"event_id": entry.event.redacts}, - retcol="sender", - allow_none=True, + redacted_event_id = entry.event.redacts + event_map = yield self._get_events_from_cache_or_db([redacted_event_id]) + original_event_entry = event_map.get(redacted_event_id) + if not original_event_entry: + # we don't have the redacted event (or it was rejected). + # + # We assume that the redaction isn't authorized for now; if the + # redacted event later turns up, the redaction will be re-checked, + # and if it is found valid, the original will get redacted before it + # is served to the client. + logger.debug( + "Withholding redaction event %s since we don't (yet) have the " + "original %s", + event_id, + redacted_event_id, ) + continue - expected_domain = get_domain_from_id(entry.event.sender) - if ( - orig_sender - and get_domain_from_id(orig_sender) == expected_domain - ): - # This redaction event is allowed. Mark as not needing a - # recheck. - entry.event.internal_metadata.recheck_redaction = False - else: - # We either don't have the event that is being redacted (so we - # assume that the event isn't authorised for now), or the - # senders don't match (so it will never be authorised). Either - # way, we shouldn't return it. - # - # (If we later receive the event, then we will redact it anyway, - # since we have this redaction) + original_event = original_event_entry.event + + if entry.event.internal_metadata.need_to_check_redaction(): + original_domain = get_domain_from_id(original_event.sender) + redaction_domain = get_domain_from_id(entry.event.sender) + if original_domain != redaction_domain: + # the senders don't match, so this is forbidden + logger.info( + "Withholding redaction %s whose sender domain %s doesn't " + "match that of redacted event %s %s", + event_id, + redaction_domain, + redacted_event_id, + original_domain, + ) continue + # Update the cache to save doing the checks again. + entry.event.internal_metadata.recheck_redaction = False + if check_redacted and entry.redacted_event: event = entry.redacted_event else: |