From cf89266b980b62a6d8547f8e1ae9394359a05fc8 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Wed, 31 Jul 2019 16:03:14 +0100
Subject: [PATCH] Deny redaction of events in a different room.
We already correctly filter out such redactions, but we should also deny
them over the CS API.
---
synapse/handlers/message.py | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index e951c39fa7..a5e23c4caf 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -795,7 +795,6 @@ class EventCreationHandler(object):
get_prev_content=False,
allow_rejected=False,
allow_none=True,
- check_room_id=event.room_id,
)
# we can make some additional checks now if we have the original event.
@@ -803,6 +802,9 @@ class EventCreationHandler(object):
if original_event.type == EventTypes.Create:
raise AuthError(403, "Redacting create events is not permitted")
+ if original_event.room_id != event.room_id:
+ raise SynapseError(400, "Cannot redact event from a different room")
+
prev_state_ids = yield context.get_prev_state_ids(self.store)
auth_events_ids = yield self.auth.compute_auth_events(
event, prev_state_ids, for_verification=True
--
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