diff --git a/synapse/event_auth.py b/synapse/event_auth.py
index 440b1ae418..0fc2c4b27e 100644
--- a/synapse/event_auth.py
+++ b/synapse/event_auth.py
@@ -150,7 +150,7 @@ async def check_state_independent_auth_rules(
# 1.5 Otherwise, allow
return
- # Check the auth events.
+ # 2. Reject if event has auth_events that: ...
auth_events = await store.get_events(
event.auth_event_ids(),
redact_behaviour=EventRedactBehaviour.as_is,
@@ -158,6 +158,7 @@ async def check_state_independent_auth_rules(
)
room_id = event.room_id
auth_dict: MutableStateMap[str] = {}
+ expected_auth_types = auth_types_for_event(event.room_version, event)
for auth_event_id in event.auth_event_ids():
auth_event = auth_events.get(auth_event_id)
@@ -179,6 +180,24 @@ async def check_state_independent_auth_rules(
% (event.event_id, room_id, auth_event_id, auth_event.room_id),
)
+ k = (auth_event.type, auth_event.state_key)
+
+ # 2.1 ... have duplicate entries for a given type and state_key pair
+ if k in auth_dict:
+ raise AuthError(
+ 403,
+ f"Event {event.event_id} has duplicate auth_events for {k}: {auth_dict[k]} and {auth_event_id}",
+ )
+
+ # 2.2 ... have entries whose type and state_key don’t match those specified by
+ # the auth events selection algorithm described in the server
+ # specification.
+ if k not in expected_auth_types:
+ raise AuthError(
+ 403,
+ f"Event {event.event_id} has unexpected auth_event for {k}: {auth_event_id}",
+ )
+
# We also need to check that the auth event itself is not rejected.
if auth_event.rejected_reason:
raise AuthError(
@@ -187,7 +206,7 @@ async def check_state_independent_auth_rules(
% (event.event_id, auth_event.event_id),
)
- auth_dict[(auth_event.type, auth_event.state_key)] = auth_event_id
+ auth_dict[k] = auth_event_id
# 3. If event does not have a m.room.create in its auth_events, reject.
creation_event = auth_dict.get((EventTypes.Create, ""), None)
|
