diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index a0103addd3..0c84c6cec4 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -888,19 +888,60 @@ class EventCreationHandler(object):
yield self.base_handler.maybe_kick_guest_users(event, context)
if event.type == EventTypes.CanonicalAlias:
- # Check the alias is acually valid (at this time at least)
+ # Validate a newly added alias or newly added alt_aliases.
+
+ original_alias = None
+ original_alt_aliases = set()
+
+ original_event_id = event.unsigned.get("replaces_state")
+ if original_event_id:
+ original_event = yield self.store.get_event(original_event_id)
+
+ if original_event:
+ original_alias = original_event.content.get("alias", None)
+ original_alt_aliases = original_event.content.get("alt_aliases", [])
+
+ # Check the alias is currently valid (if it has changed).
room_alias_str = event.content.get("alias", None)
- if room_alias_str:
+ directory_handler = self.hs.get_handlers().directory_handler
+ if room_alias_str and room_alias_str != original_alias:
room_alias = RoomAlias.from_string(room_alias_str)
- directory_handler = self.hs.get_handlers().directory_handler
mapping = yield directory_handler.get_association(room_alias)
if mapping["room_id"] != event.room_id:
raise SynapseError(
400,
"Room alias %s does not point to the room" % (room_alias_str,),
+ Codes.BAD_ALIAS,
)
+ # Check that alt_aliases is the proper form.
+ alt_aliases = event.content.get("alt_aliases", [])
+ if not isinstance(alt_aliases, (list, tuple)):
+ raise SynapseError(
+ 400, "The alt_aliases property must be a list.", Codes.INVALID_PARAM
+ )
+
+ # If the old version of alt_aliases is of an unknown form,
+ # completely replace it.
+ if not isinstance(original_alt_aliases, (list, tuple)):
+ original_alt_aliases = []
+
+ # Check that each alias is currently valid.
+ new_alt_aliases = set(alt_aliases) - set(original_alt_aliases)
+ if new_alt_aliases:
+ for alias_str in new_alt_aliases:
+ room_alias = RoomAlias.from_string(alias_str)
+ mapping = yield directory_handler.get_association(room_alias)
+
+ if mapping["room_id"] != event.room_id:
+ raise SynapseError(
+ 400,
+ "Room alias %s does not point to the room"
+ % (room_alias_str,),
+ Codes.BAD_ALIAS,
+ )
+
federation_handler = self.hs.get_handlers().federation_handler
if event.type == EventTypes.Member:
|
