diff options
| -rw-r--r-- | changelog.d/15695.bugfix | 1 | ||||
| -rw-r--r-- | synapse/handlers/room.py | 76 | ||||
| -rw-r--r-- | tests/rest/client/test_rooms.py | 37 |
3 files changed, 100 insertions, 14 deletions
diff --git a/changelog.d/15695.bugfix b/changelog.d/15695.bugfix new file mode 100644 index 0000000000..99bf1fe05e --- /dev/null +++ b/changelog.d/15695.bugfix @@ -0,0 +1 @@ +Check permissions for enabling encryption earlier during room creation to avoid creating broken rooms. diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py index cb957f2033..bf907b7881 100644 --- a/synapse/handlers/room.py +++ b/synapse/handlers/room.py @@ -872,6 +872,8 @@ class RoomCreationHandler: visibility = config.get("visibility", "private") is_public = visibility == "public" + self._validate_room_config(config, visibility) + room_id = await self._generate_and_create_room_id( creator_id=user_id, is_public=is_public, @@ -1111,20 +1113,7 @@ class RoomCreationHandler: return new_event, new_unpersisted_context - visibility = room_config.get("visibility", "private") - preset_config = room_config.get( - "preset", - RoomCreationPreset.PRIVATE_CHAT - if visibility == "private" - else RoomCreationPreset.PUBLIC_CHAT, - ) - - try: - config = self._presets_dict[preset_config] - except KeyError: - raise SynapseError( - 400, f"'{preset_config}' is not a valid preset", errcode=Codes.BAD_JSON - ) + preset_config, config = self._room_preset_config(room_config) # MSC2175 removes the creator field from the create event. if not room_version.msc2175_implicit_room_creator: @@ -1306,6 +1295,65 @@ class RoomCreationHandler: assert last_event.internal_metadata.stream_ordering is not None return last_event.internal_metadata.stream_ordering, last_event.event_id, depth + def _validate_room_config( + self, + config: JsonDict, + visibility: str, + ) -> None: + """Checks configuration parameters for a /createRoom request. + + If validation detects invalid parameters an exception may be raised to + cause room creation to be aborted and an error response to be returned + to the client. + + Args: + config: A dict of configuration options. Originally from the body of + the /createRoom request + visibility: One of "public" or "private" + """ + + # Validate the requested preset, raise a 400 error if not valid + preset_name, preset_config = self._room_preset_config(config) + + # If the user is trying to create an encrypted room and this is forbidden + # by the configured default_power_level_content_override, then reject the + # request before the room is created. + raw_initial_state = config.get("initial_state", []) + room_encryption_event = any( + s.get("type", "") == EventTypes.RoomEncryption for s in raw_initial_state + ) + + if preset_config["encrypted"] or room_encryption_event: + if self._default_power_level_content_override: + override = self._default_power_level_content_override.get(preset_name) + if override is not None: + event_levels = override.get("events", {}) + room_admin_level = event_levels.get(EventTypes.PowerLevels, 100) + encryption_level = event_levels.get(EventTypes.RoomEncryption, 100) + if encryption_level > room_admin_level: + raise SynapseError( + 403, + f"You cannot create an encrypted room. user_level ({room_admin_level}) < send_level ({encryption_level})", + ) + + def _room_preset_config(self, room_config: JsonDict) -> Tuple[str, dict]: + # The spec says rooms should default to private visibility if + # `visibility` is not specified. + visibility = room_config.get("visibility", "private") + preset_name = room_config.get( + "preset", + RoomCreationPreset.PRIVATE_CHAT + if visibility == "private" + else RoomCreationPreset.PUBLIC_CHAT, + ) + try: + preset_config = self._presets_dict[preset_name] + except KeyError: + raise SynapseError( + 400, f"'{preset_name}' is not a valid preset", errcode=Codes.BAD_JSON + ) + return preset_name, preset_config + def _generate_room_id(self) -> str: """Generates a random room ID. diff --git a/tests/rest/client/test_rooms.py b/tests/rest/client/test_rooms.py index 4d39c89f6f..f1b4e1ad2f 100644 --- a/tests/rest/client/test_rooms.py +++ b/tests/rest/client/test_rooms.py @@ -1941,6 +1941,43 @@ class RoomPowerLevelOverridesInPracticeTestCase(RoomBase): channel.json_body["error"], ) + @unittest.override_config( + { + "default_power_level_content_override": { + "private_chat": { + "events": { + "m.room.avatar": 50, + "m.room.canonical_alias": 50, + "m.room.encryption": 999, + "m.room.history_visibility": 100, + "m.room.name": 50, + "m.room.power_levels": 100, + "m.room.server_acl": 100, + "m.room.tombstone": 100, + }, + "events_default": 0, + }, + } + }, + ) + def test_config_override_blocks_encrypted_room(self) -> None: + # Given the server has config for private_chats, + + # When I attempt to create an encrypted private_chat room + channel = self.make_request( + "POST", + "/createRoom", + '{"creation_content": {"m.federate": false},"name": "Secret Private Room","preset": "private_chat","initial_state": [{"type": "m.room.encryption","state_key": "","content": {"algorithm": "m.megolm.v1.aes-sha2"}}]}', + ) + + # Then I am not allowed because the required power level is unattainable + self.assertEqual(HTTPStatus.FORBIDDEN, channel.code, msg=channel.result["body"]) + self.assertEqual( + "You cannot create an encrypted room. " + + "user_level (100) < send_level (999)", + channel.json_body["error"], + ) + class RoomInitialSyncTestCase(RoomBase): """Tests /rooms/$room_id/initialSync.""" |