511 lines
		
	
	
		
			19 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			511 lines
		
	
	
		
			19 KiB
		
	
	
	
		
			Python
		
	
	
| # Copyright 2014-2016 OpenMarket Ltd
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| #
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| # Licensed under the Apache License, Version 2.0 (the "License");
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| # you may not use this file except in compliance with the License.
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| # You may obtain a copy of the License at
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| #
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| #     http://www.apache.org/licenses/LICENSE-2.0
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| #
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| # Unless required by applicable law or agreed to in writing, software
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| # distributed under the License is distributed on an "AS IS" BASIS,
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| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| # See the License for the specific language governing permissions and
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| # limitations under the License.
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| 
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| import logging
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| import string
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| from typing import TYPE_CHECKING, Iterable, List, Optional
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| 
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| from synapse.api.constants import MAX_ALIAS_LENGTH, EventTypes
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| from synapse.api.errors import (
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|     AuthError,
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|     CodeMessageException,
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|     Codes,
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|     NotFoundError,
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|     ShadowBanError,
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|     StoreError,
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|     SynapseError,
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| )
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| from synapse.appservice import ApplicationService
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| from synapse.storage.databases.main.directory import RoomAliasMapping
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| from synapse.types import JsonDict, Requester, RoomAlias, UserID, get_domain_from_id
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| 
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| from ._base import BaseHandler
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| 
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| if TYPE_CHECKING:
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|     from synapse.server import HomeServer
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| 
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| logger = logging.getLogger(__name__)
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| 
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| 
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| class DirectoryHandler(BaseHandler):
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|     def __init__(self, hs: "HomeServer"):
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|         super().__init__(hs)
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| 
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|         self.state = hs.get_state_handler()
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|         self.appservice_handler = hs.get_application_service_handler()
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|         self.event_creation_handler = hs.get_event_creation_handler()
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|         self.store = hs.get_datastore()
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|         self.config = hs.config
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|         self.enable_room_list_search = hs.config.enable_room_list_search
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|         self.require_membership = hs.config.require_membership_for_aliases
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|         self.third_party_event_rules = hs.get_third_party_event_rules()
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| 
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|         self.federation = hs.get_federation_client()
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|         hs.get_federation_registry().register_query_handler(
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|             "directory", self.on_directory_query
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|         )
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| 
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|         self.spam_checker = hs.get_spam_checker()
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| 
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|     async def _create_association(
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|         self,
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|         room_alias: RoomAlias,
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|         room_id: str,
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|         servers: Optional[Iterable[str]] = None,
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|         creator: Optional[str] = None,
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|     ) -> None:
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|         # general association creation for both human users and app services
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| 
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|         for wchar in string.whitespace:
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|             if wchar in room_alias.localpart:
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|                 raise SynapseError(400, "Invalid characters in room alias")
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| 
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|         if not self.hs.is_mine(room_alias):
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|             raise SynapseError(400, "Room alias must be local")
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|             # TODO(erikj): Change this.
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| 
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|         # TODO(erikj): Add transactions.
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|         # TODO(erikj): Check if there is a current association.
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|         if not servers:
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|             users = await self.store.get_users_in_room(room_id)
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|             servers = {get_domain_from_id(u) for u in users}
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| 
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|         if not servers:
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|             raise SynapseError(400, "Failed to get server list")
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| 
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|         await self.store.create_room_alias_association(
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|             room_alias, room_id, servers, creator=creator
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|         )
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| 
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|     async def create_association(
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|         self,
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|         requester: Requester,
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|         room_alias: RoomAlias,
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|         room_id: str,
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|         servers: Optional[List[str]] = None,
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|         check_membership: bool = True,
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|     ) -> None:
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|         """Attempt to create a new alias
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| 
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|         Args:
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|             requester
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|             room_alias
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|             room_id
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|             servers: Iterable of servers that others servers should try and join via
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|             check_membership: Whether to check if the user is in the room
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|                 before the alias can be set (if the server's config requires it).
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|         """
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| 
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|         user_id = requester.user.to_string()
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|         room_alias_str = room_alias.to_string()
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| 
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|         if len(room_alias_str) > MAX_ALIAS_LENGTH:
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|             raise SynapseError(
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|                 400,
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|                 "Can't create aliases longer than %s characters" % MAX_ALIAS_LENGTH,
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|                 Codes.INVALID_PARAM,
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|             )
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| 
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|         service = requester.app_service
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|         if service:
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|             if not service.is_interested_in_alias(room_alias_str):
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|                 raise SynapseError(
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|                     400,
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|                     "This application service has not reserved this kind of alias.",
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|                     errcode=Codes.EXCLUSIVE,
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|                 )
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|         else:
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|             # Server admins are not subject to the same constraints as normal
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|             # users when creating an alias (e.g. being in the room).
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|             is_admin = await self.auth.is_server_admin(requester.user)
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| 
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|             if (self.require_membership and check_membership) and not is_admin:
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|                 rooms_for_user = await self.store.get_rooms_for_user(user_id)
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|                 if room_id not in rooms_for_user:
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|                     raise AuthError(
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|                         403, "You must be in the room to create an alias for it"
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|                     )
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| 
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|             if not await self.spam_checker.user_may_create_room_alias(
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|                 user_id, room_alias
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|             ):
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|                 raise AuthError(403, "This user is not permitted to create this alias")
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| 
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|             if not self.config.is_alias_creation_allowed(
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|                 user_id, room_id, room_alias_str
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|             ):
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|                 # Lets just return a generic message, as there may be all sorts of
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|                 # reasons why we said no. TODO: Allow configurable error messages
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|                 # per alias creation rule?
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|                 raise SynapseError(403, "Not allowed to create alias")
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| 
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|             can_create = self.can_modify_alias(room_alias, user_id=user_id)
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|             if not can_create:
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|                 raise AuthError(
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|                     400,
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|                     "This alias is reserved by an application service.",
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|                     errcode=Codes.EXCLUSIVE,
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|                 )
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| 
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|         await self._create_association(room_alias, room_id, servers, creator=user_id)
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| 
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|     async def delete_association(
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|         self, requester: Requester, room_alias: RoomAlias
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|     ) -> str:
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|         """Remove an alias from the directory
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| 
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|         (this is only meant for human users; AS users should call
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|         delete_appservice_association)
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| 
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|         Args:
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|             requester
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|             room_alias
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| 
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|         Returns:
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|             room id that the alias used to point to
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| 
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|         Raises:
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|             NotFoundError: if the alias doesn't exist
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| 
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|             AuthError: if the user doesn't have perms to delete the alias (ie, the user
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|                 is neither the creator of the alias, nor a server admin.
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| 
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|             SynapseError: if the alias belongs to an AS
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|         """
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|         user_id = requester.user.to_string()
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| 
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|         try:
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|             can_delete = await self._user_can_delete_alias(room_alias, user_id)
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|         except StoreError as e:
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|             if e.code == 404:
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|                 raise NotFoundError("Unknown room alias")
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|             raise
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| 
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|         if not can_delete:
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|             raise AuthError(403, "You don't have permission to delete the alias.")
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| 
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|         can_delete = self.can_modify_alias(room_alias, user_id=user_id)
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|         if not can_delete:
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|             raise SynapseError(
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|                 400,
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|                 "This alias is reserved by an application service.",
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|                 errcode=Codes.EXCLUSIVE,
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|             )
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| 
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|         room_id = await self._delete_association(room_alias)
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| 
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|         try:
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|             await self._update_canonical_alias(requester, user_id, room_id, room_alias)
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|         except ShadowBanError as e:
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|             logger.info("Failed to update alias events due to shadow-ban: %s", e)
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|         except AuthError as e:
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|             logger.info("Failed to update alias events: %s", e)
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| 
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|         return room_id
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| 
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|     async def delete_appservice_association(
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|         self, service: ApplicationService, room_alias: RoomAlias
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|     ) -> None:
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|         if not service.is_interested_in_alias(room_alias.to_string()):
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|             raise SynapseError(
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|                 400,
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|                 "This application service has not reserved this kind of alias",
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|                 errcode=Codes.EXCLUSIVE,
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|             )
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|         await self._delete_association(room_alias)
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| 
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|     async def _delete_association(self, room_alias: RoomAlias) -> str:
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|         if not self.hs.is_mine(room_alias):
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|             raise SynapseError(400, "Room alias must be local")
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| 
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|         room_id = await self.store.delete_room_alias(room_alias)
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| 
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|         return room_id
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| 
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|     async def get_association(self, room_alias: RoomAlias) -> JsonDict:
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|         room_id = None
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|         if self.hs.is_mine(room_alias):
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|             result = await self.get_association_from_room_alias(
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|                 room_alias
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|             )  # type: Optional[RoomAliasMapping]
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| 
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|             if result:
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|                 room_id = result.room_id
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|                 servers = result.servers
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|         else:
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|             try:
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|                 fed_result = await self.federation.make_query(
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|                     destination=room_alias.domain,
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|                     query_type="directory",
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|                     args={"room_alias": room_alias.to_string()},
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|                     retry_on_dns_fail=False,
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|                     ignore_backoff=True,
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|                 )
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|             except CodeMessageException as e:
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|                 logging.warning("Error retrieving alias")
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|                 if e.code == 404:
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|                     fed_result = None
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|                 else:
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|                     raise
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| 
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|             if fed_result and "room_id" in fed_result and "servers" in fed_result:
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|                 room_id = fed_result["room_id"]
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|                 servers = fed_result["servers"]
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| 
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|         if not room_id:
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|             raise SynapseError(
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|                 404,
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|                 "Room alias %s not found" % (room_alias.to_string(),),
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|                 Codes.NOT_FOUND,
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|             )
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| 
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|         users = await self.store.get_users_in_room(room_id)
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|         extra_servers = {get_domain_from_id(u) for u in users}
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|         servers = set(extra_servers) | set(servers)
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| 
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|         # If this server is in the list of servers, return it first.
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|         if self.server_name in servers:
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|             servers = [self.server_name] + [s for s in servers if s != self.server_name]
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|         else:
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|             servers = list(servers)
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| 
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|         return {"room_id": room_id, "servers": servers}
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| 
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|     async def on_directory_query(self, args: JsonDict) -> JsonDict:
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|         room_alias = RoomAlias.from_string(args["room_alias"])
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|         if not self.hs.is_mine(room_alias):
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|             raise SynapseError(400, "Room Alias is not hosted on this homeserver")
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| 
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|         result = await self.get_association_from_room_alias(room_alias)
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| 
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|         if result is not None:
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|             return {"room_id": result.room_id, "servers": result.servers}
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|         else:
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|             raise SynapseError(
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|                 404,
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|                 "Room alias %r not found" % (room_alias.to_string(),),
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|                 Codes.NOT_FOUND,
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|             )
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| 
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|     async def _update_canonical_alias(
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|         self, requester: Requester, user_id: str, room_id: str, room_alias: RoomAlias
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|     ) -> None:
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|         """
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|         Send an updated canonical alias event if the removed alias was set as
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|         the canonical alias or listed in the alt_aliases field.
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| 
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|         Raises:
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|             ShadowBanError if the requester has been shadow-banned.
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|         """
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|         alias_event = await self.state.get_current_state(
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|             room_id, EventTypes.CanonicalAlias, ""
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|         )
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| 
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|         # There is no canonical alias, nothing to do.
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|         if not alias_event:
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|             return
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| 
 | |
|         # Obtain a mutable version of the event content.
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|         content = dict(alias_event.content)
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|         send_update = False
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| 
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|         # Remove the alias property if it matches the removed alias.
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|         alias_str = room_alias.to_string()
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|         if alias_event.content.get("alias", "") == alias_str:
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|             send_update = True
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|             content.pop("alias", "")
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| 
 | |
|         # Filter the alt_aliases property for the removed alias. Note that the
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|         # value is not modified if alt_aliases is of an unexpected form.
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|         alt_aliases = content.get("alt_aliases")
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|         if isinstance(alt_aliases, (list, tuple)) and alias_str in alt_aliases:
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|             send_update = True
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|             alt_aliases = [alias for alias in alt_aliases if alias != alias_str]
 | |
| 
 | |
|             if alt_aliases:
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|                 content["alt_aliases"] = alt_aliases
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|             else:
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|                 del content["alt_aliases"]
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| 
 | |
|         if send_update:
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|             await self.event_creation_handler.create_and_send_nonmember_event(
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|                 requester,
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|                 {
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|                     "type": EventTypes.CanonicalAlias,
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|                     "state_key": "",
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|                     "room_id": room_id,
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|                     "sender": user_id,
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|                     "content": content,
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|                 },
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|                 ratelimit=False,
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|             )
 | |
| 
 | |
|     async def get_association_from_room_alias(
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|         self, room_alias: RoomAlias
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|     ) -> Optional[RoomAliasMapping]:
 | |
|         result = await self.store.get_association_from_room_alias(room_alias)
 | |
|         if not result:
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|             # Query AS to see if it exists
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|             as_handler = self.appservice_handler
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|             result = await as_handler.query_room_alias_exists(room_alias)
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|         return result
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| 
 | |
|     def can_modify_alias(self, alias: RoomAlias, user_id: Optional[str] = None) -> bool:
 | |
|         # Any application service "interested" in an alias they are regexing on
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|         # can modify the alias.
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|         # Users can only modify the alias if ALL the interested services have
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|         # non-exclusive locks on the alias (or there are no interested services)
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|         services = self.store.get_app_services()
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|         interested_services = [
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|             s for s in services if s.is_interested_in_alias(alias.to_string())
 | |
|         ]
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| 
 | |
|         for service in interested_services:
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|             if user_id == service.sender:
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|                 # this user IS the app service so they can do whatever they like
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|                 return True
 | |
|             elif service.is_exclusive_alias(alias.to_string()):
 | |
|                 # another service has an exclusive lock on this alias.
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|                 return False
 | |
|         # either no interested services, or no service with an exclusive lock
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|         return True
 | |
| 
 | |
|     async def _user_can_delete_alias(self, alias: RoomAlias, user_id: str) -> bool:
 | |
|         """Determine whether a user can delete an alias.
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| 
 | |
|         One of the following must be true:
 | |
| 
 | |
|         1. The user created the alias.
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|         2. The user is a server administrator.
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|         3. The user has a power-level sufficient to send a canonical alias event
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|            for the current room.
 | |
| 
 | |
|         """
 | |
|         creator = await self.store.get_room_alias_creator(alias.to_string())
 | |
| 
 | |
|         if creator == user_id:
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|             return True
 | |
| 
 | |
|         # Resolve the alias to the corresponding room.
 | |
|         room_mapping = await self.get_association(alias)
 | |
|         room_id = room_mapping["room_id"]
 | |
|         if not room_id:
 | |
|             return False
 | |
| 
 | |
|         return await self.auth.check_can_change_room_list(
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|             room_id, UserID.from_string(user_id)
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|         )
 | |
| 
 | |
|     async def edit_published_room_list(
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|         self, requester: Requester, room_id: str, visibility: str
 | |
|     ) -> None:
 | |
|         """Edit the entry of the room in the published room list.
 | |
| 
 | |
|         requester
 | |
|         room_id
 | |
|         visibility: "public" or "private"
 | |
|         """
 | |
|         user_id = requester.user.to_string()
 | |
| 
 | |
|         if not await self.spam_checker.user_may_publish_room(user_id, room_id):
 | |
|             raise AuthError(
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|                 403, "This user is not permitted to publish rooms to the room list"
 | |
|             )
 | |
| 
 | |
|         if requester.is_guest:
 | |
|             raise AuthError(403, "Guests cannot edit the published room list")
 | |
| 
 | |
|         if visibility not in ["public", "private"]:
 | |
|             raise SynapseError(400, "Invalid visibility setting")
 | |
| 
 | |
|         if visibility == "public" and not self.enable_room_list_search:
 | |
|             # The room list has been disabled.
 | |
|             raise AuthError(
 | |
|                 403, "This user is not permitted to publish rooms to the room list"
 | |
|             )
 | |
| 
 | |
|         room = await self.store.get_room(room_id)
 | |
|         if room is None:
 | |
|             raise SynapseError(400, "Unknown room")
 | |
| 
 | |
|         can_change_room_list = await self.auth.check_can_change_room_list(
 | |
|             room_id, requester.user
 | |
|         )
 | |
|         if not can_change_room_list:
 | |
|             raise AuthError(
 | |
|                 403,
 | |
|                 "This server requires you to be a moderator in the room to"
 | |
|                 " edit its room list entry",
 | |
|             )
 | |
| 
 | |
|         making_public = visibility == "public"
 | |
|         if making_public:
 | |
|             room_aliases = await self.store.get_aliases_for_room(room_id)
 | |
|             canonical_alias = await self.store.get_canonical_alias_for_room(room_id)
 | |
|             if canonical_alias:
 | |
|                 room_aliases.append(canonical_alias)
 | |
| 
 | |
|             if not self.config.is_publishing_room_allowed(
 | |
|                 user_id, room_id, room_aliases
 | |
|             ):
 | |
|                 # Lets just return a generic message, as there may be all sorts of
 | |
|                 # reasons why we said no. TODO: Allow configurable error messages
 | |
|                 # per alias creation rule?
 | |
|                 raise SynapseError(403, "Not allowed to publish room")
 | |
| 
 | |
|             # Check if publishing is blocked by a third party module
 | |
|             allowed_by_third_party_rules = await (
 | |
|                 self.third_party_event_rules.check_visibility_can_be_modified(
 | |
|                     room_id, visibility
 | |
|                 )
 | |
|             )
 | |
|             if not allowed_by_third_party_rules:
 | |
|                 raise SynapseError(403, "Not allowed to publish room")
 | |
| 
 | |
|         await self.store.set_room_is_public(room_id, making_public)
 | |
| 
 | |
|     async def edit_published_appservice_room_list(
 | |
|         self, appservice_id: str, network_id: str, room_id: str, visibility: str
 | |
|     ) -> None:
 | |
|         """Add or remove a room from the appservice/network specific public
 | |
|         room list.
 | |
| 
 | |
|         Args:
 | |
|             appservice_id: ID of the appservice that owns the list
 | |
|             network_id: The ID of the network the list is associated with
 | |
|             room_id
 | |
|             visibility: either "public" or "private"
 | |
|         """
 | |
|         if visibility not in ["public", "private"]:
 | |
|             raise SynapseError(400, "Invalid visibility setting")
 | |
| 
 | |
|         await self.store.set_room_is_public_appservice(
 | |
|             room_id, appservice_id, network_id, visibility == "public"
 | |
|         )
 | |
| 
 | |
|     async def get_aliases_for_room(
 | |
|         self, requester: Requester, room_id: str
 | |
|     ) -> List[str]:
 | |
|         """
 | |
|         Get a list of the aliases that currently point to this room on this server
 | |
|         """
 | |
|         # allow access to server admins and current members of the room
 | |
|         is_admin = await self.auth.is_server_admin(requester.user)
 | |
|         if not is_admin:
 | |
|             await self.auth.check_user_in_room_or_world_readable(
 | |
|                 room_id, requester.user.to_string()
 | |
|             )
 | |
| 
 | |
|         return await self.store.get_aliases_for_room(room_id)
 |