# Copyright 2016 OpenMarket Ltd # Copyright 2019 New Vector Ltd # Copyright 2019,2020 The Matrix.org Foundation C.I.C. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. import logging from typing import ( TYPE_CHECKING, Any, Collection, Dict, Iterable, List, Mapping, Optional, Set, Tuple, ) from synapse.api import errors from synapse.api.constants import EventTypes from synapse.api.errors import ( Codes, FederationDeniedError, HttpResponseException, RequestSendFailed, SynapseError, ) from synapse.logging.opentracing import log_kv, set_tag, trace from synapse.metrics.background_process_metrics import ( run_as_background_process, wrap_as_background_process, ) from synapse.types import ( JsonDict, StreamToken, UserID, get_domain_from_id, get_verify_key_from_cross_signing_key, ) from synapse.util import stringutils from synapse.util.async_helpers import Linearizer from synapse.util.caches.expiringcache import ExpiringCache from synapse.util.metrics import measure_func from synapse.util.retryutils import NotRetryingDestination if TYPE_CHECKING: from synapse.server import HomeServer logger = logging.getLogger(__name__) MAX_DEVICE_DISPLAY_NAME_LEN = 100 class DeviceWorkerHandler: def __init__(self, hs: "HomeServer"): self.clock = hs.get_clock() self.hs = hs self.store = hs.get_datastores().main self.notifier = hs.get_notifier() self.state = hs.get_state_handler() self.state_store = hs.get_storage().state self._auth_handler = hs.get_auth_handler() self.server_name = hs.hostname @trace async def get_devices_by_user(self, user_id: str) -> List[JsonDict]: """ Retrieve the given user's devices Args: user_id: The user ID to query for devices. Returns: info on each device """ set_tag("user_id", user_id) device_map = await self.store.get_devices_by_user(user_id) ips = await self.store.get_last_client_ip_by_device(user_id, device_id=None) devices = list(device_map.values()) for device in devices: _update_device_from_client_ips(device, ips) log_kv(device_map) return devices @trace async def get_device(self, user_id: str, device_id: str) -> JsonDict: """Retrieve the given device Args: user_id: The user to get the device from device_id: The device to fetch. Returns: info on the device Raises: errors.NotFoundError: if the device was not found """ device = await self.store.get_device(user_id, device_id) if device is None: raise errors.NotFoundError() ips = await self.store.get_last_client_ip_by_device(user_id, device_id) _update_device_from_client_ips(device, ips) set_tag("device", device) set_tag("ips", ips) return device @trace @measure_func("device.get_user_ids_changed") async def get_user_ids_changed( self, user_id: str, from_token: StreamToken ) -> JsonDict: """Get list of users that have had the devices updated, or have newly joined a room, that `user_id` may be interested in. """ set_tag("user_id", user_id) set_tag("from_token", from_token) now_room_key = self.store.get_room_max_token() room_ids = await self.store.get_rooms_for_user(user_id) # First we check if any devices have changed for users that we share # rooms with. users_who_share_room = await self.store.get_users_who_share_room_with_user( user_id ) tracked_users = set(users_who_share_room) # Always tell the user about their own devices tracked_users.add(user_id) changed = await self.store.get_users_whose_devices_changed( from_token.device_list_key, tracked_users ) # Then work out if any users have since joined rooms_changed = self.store.get_rooms_that_changed(room_ids, from_token.room_key) member_events = await self.store.get_membership_changes_for_user( user_id, from_token.room_key, now_room_key ) rooms_changed.update(event.room_id for event in member_events) stream_ordering = from_token.room_key.stream possibly_changed = set(changed) possibly_left = set() for room_id in rooms_changed: current_state_ids = await self.store.get_current_state_ids(room_id) # The user may have left the room # TODO: Check if they actually did or if we were just invited. if room_id not in room_ids: for etype, state_key in current_state_ids.keys(): if etype != EventTypes.Member: continue possibly_left.add(state_key) continue # Fetch the current state at the time. try: event_ids = await self.store.get_forward_extremities_for_room_at_stream_ordering( room_id, stream_ordering=stream_ordering ) except errors.StoreError: # we have purged the stream_ordering index since the stream # ordering: treat it the same as a new room event_ids = [] # special-case for an empty prev state: include all members # in the changed list if not event_ids: log_kv( {"event": "encountered empty previous state", "room_id": room_id} ) for etype, state_key in current_state_ids.keys(): if etype != EventTypes.Member: continue possibly_changed.add(state_key) continue current_member_id = current_state_ids.get((EventTypes.Member, user_id)) if not current_member_id: continue # mapping from event_id -> state_dict prev_state_ids = await self.state_store.get_state_ids_for_events(event_ids) # Check if we've joined the room? If so we just blindly add all the users to # the "possibly changed" users. for state_dict in prev_state_ids.values(): member_event = state_dict.get((EventTypes.Member, user_id), None) if not member_event or member_event != current_member_id: for etype, state_key in current_state_ids.keys(): if etype != EventTypes.Member: continue possibly_changed.add(state_key) break # If there has been any change in membership, include them in the # possibly changed list. We'll check if they are joined below, # and we're not toooo worried about spuriously adding users. for key, event_id in current_state_ids.items(): etype, state_key = key if etype != EventTypes.Member: continue # check if this member has changed since any of the extremities # at the stream_ordering, and add them to the list if so. for state_dict in prev_state_ids.values(): prev_event_id = state_dict.get(key, None) if not prev_event_id or prev_event_id != event_id: if state_key != user_id: possibly_changed.add(state_key) break if possibly_changed or possibly_left: # Take the intersection of the users whose devices may have changed # and those that actually still share a room with the user possibly_joined = possibly_changed & users_who_share_room possibly_left = (possibly_changed | possibly_left) - users_who_share_room else: possibly_joined = set() possibly_left = set() result = {"changed": list(possibly_joined), "left": list(possibly_left)} log_kv(result) return result async def on_federation_query_user_devices(self, user_id: str) -> JsonDict: stream_id, devices = await self.store.get_e2e_device_keys_for_federation_query( user_id ) master_key = await self.store.get_e2e_cross_signing_key(user_id, "master") self_signing_key = await self.store.get_e2e_cross_signing_key( user_id, "self_signing" ) return { "user_id": user_id, "stream_id": stream_id, "devices": devices, "master_key": master_key, "self_signing_key": self_signing_key, } class DeviceHandler(DeviceWorkerHandler): def __init__(self, hs: "HomeServer"): super().__init__(hs) self.federation_sender = hs.get_federation_sender() self.device_list_updater = DeviceListUpdater(hs, self) federation_registry = hs.get_federation_registry() federation_registry.register_edu_handler( "m.device_list_update", self.device_list_updater.incoming_device_list_update ) hs.get_distributor().observe("user_left_room", self.user_left_room) # Whether `_handle_new_device_update_async` is currently processing. self._handle_new_device_update_is_processing = False # If a new device update may have happened while the loop was # processing. self._handle_new_device_update_new_data = False # On start up check if there are any updates pending. hs.get_reactor().callWhenRunning(self._handle_new_device_update_async) def _check_device_name_length(self, name: Optional[str]) -> None: """ Checks whether a device name is longer than the maximum allowed length. Args: name: The name of the device. Raises: SynapseError: if the device name is too long. """ if name and len(name) > MAX_DEVICE_DISPLAY_NAME_LEN: raise SynapseError( 400, "Device display name is too long (max %i)" % (MAX_DEVICE_DISPLAY_NAME_LEN,), errcode=Codes.TOO_LARGE, ) async def check_device_registered( self, user_id: str, device_id: Optional[str], initial_device_display_name: Optional[str] = None, auth_provider_id: Optional[str] = None, auth_provider_session_id: Optional[str] = None, ) -> str: """ If the given device has not been registered, register it with the supplied display name. If no device_id is supplied, we make one up. Args: user_id: @user:id device_id: device id supplied by client initial_device_display_name: device display name from client auth_provider_id: The SSO IdP the user used, if any. auth_provider_session_id: The session ID (sid) got from the SSO IdP. Returns: device id (generated if none was supplied) """ self._check_device_name_length(initial_device_display_name) if device_id is not None: new_device = await self.store.store_device( user_id=user_id, device_id=device_id, initial_device_display_name=initial_device_display_name, auth_provider_id=auth_provider_id, auth_provider_session_id=auth_provider_session_id, ) if new_device: await self.notify_device_update(user_id, [device_id]) return device_id # if the device id is not specified, we'll autogen one, but loop a few # times in case of a clash. attempts = 0 while attempts < 5: new_device_id = stringutils.random_string(10).upper() new_device = await self.store.store_device( user_id=user_id, device_id=new_device_id, initial_device_display_name=initial_device_display_name, auth_provider_id=auth_provider_id, auth_provider_session_id=auth_provider_session_id, ) if new_device: await self.notify_device_update(user_id, [new_device_id]) return new_device_id attempts += 1 raise errors.StoreError(500, "Couldn't generate a device ID.") @trace async def delete_device(self, user_id: str, device_id: str) -> None: """Delete the given device Args: user_id: The user to delete the device from. device_id: The device to delete. """ try: await self.store.delete_device(user_id, device_id) except errors.StoreError as e: if e.code == 404: # no match set_tag("error", True) log_kv( {"reason": "User doesn't have device id.", "device_id": device_id} ) else: raise await self._auth_handler.delete_access_tokens_for_user( user_id, device_id=device_id ) await self.store.delete_e2e_keys_by_device(user_id=user_id, device_id=device_id) await self.notify_device_update(user_id, [device_id]) @trace async def delete_all_devices_for_user( self, user_id: str, except_device_id: Optional[str] = None ) -> None: """Delete all of the user's devices Args: user_id: The user to remove all devices from except_device_id: optional device id which should not be deleted """ device_map = await self.store.get_devices_by_user(user_id) device_ids = list(device_map) if except_device_id is not None: device_ids = [d for d in device_ids if d != except_device_id] await self.delete_devices(user_id, device_ids) async def delete_devices(self, user_id: str, device_ids: List[str]) -> None: """Delete several devices Args: user_id: The user to delete devices from. device_ids: The list of device IDs to delete """ try: await self.store.delete_devices(user_id, device_ids) except errors.StoreError as e: if e.code == 404: # no match set_tag("error", True) set_tag("reason", "User doesn't have that device id.") else: raise # Delete access tokens and e2e keys for each device. Not optimised as it is not # considered as part of a critical path. for device_id in device_ids: await self._auth_handler.delete_access_tokens_for_user( user_id, device_id=device_id ) await self.store.delete_e2e_keys_by_device( user_id=user_id, device_id=device_id ) await self.notify_device_update(user_id, device_ids) async def update_device(self, user_id: str, device_id: str, content: dict) -> None: """Update the given device Args: user_id: The user to update devices of. device_id: The device to update. content: body of update request """ # Reject a new displayname which is too long. new_display_name = content.get("display_name") self._check_device_name_length(new_display_name) try: await self.store.update_device( user_id, device_id, new_display_name=new_display_name ) await self.notify_device_update(user_id, [device_id]) except errors.StoreError as e: if e.code == 404: raise errors.NotFoundError() else: raise @trace @measure_func("notify_device_update") async def notify_device_update( self, user_id: str, device_ids: Collection[str] ) -> None: """Notify that a user's device(s) has changed. Pokes the notifier, and remote servers if the user is local. Args: user_id: The Matrix ID of the user who's device list has been updated. device_ids: The device IDs that have changed. """ if not device_ids: # No changes to notify about, so this is a no-op. return room_ids = await self.store.get_rooms_for_user(user_id) position = await self.store.add_device_change_to_streams( user_id, device_ids, room_ids=room_ids, ) if not position: # This should only happen if there are no updates, so we bail. return for device_id in device_ids: logger.debug( "Notifying about update %r/%r, ID: %r", user_id, device_id, position ) # specify the user ID too since the user should always get their own device list # updates, even if they aren't in any rooms. self.notifier.on_new_event( "device_list_key", position, users={user_id}, rooms=room_ids ) # We may need to do some processing asynchronously. self._handle_new_device_update_async() async def notify_user_signature_update( self, from_user_id: str, user_ids: List[str] ) -> None: """Notify a user that they have made new signatures of other users. Args: from_user_id: the user who made the signature user_ids: the users IDs that have new signatures """ position = await self.store.add_user_signature_change_to_streams( from_user_id, user_ids ) self.notifier.on_new_event("device_list_key", position, users=[from_user_id]) async def user_left_room(self, user: UserID, room_id: str) -> None: user_id = user.to_string() room_ids = await self.store.get_rooms_for_user(user_id) if not room_ids: # We no longer share rooms with this user, so we'll no longer # receive device updates. Mark this in DB. await self.store.mark_remote_user_device_list_as_unsubscribed(user_id) async def store_dehydrated_device( self, user_id: str, device_data: JsonDict, initial_device_display_name: Optional[str] = None, ) -> str: """Store a dehydrated device for a user. If the user had a previous dehydrated device, it is removed. Args: user_id: the user that we are storing the device for device_data: the dehydrated device information initial_device_display_name: The display name to use for the device Returns: device id of the dehydrated device """ device_id = await self.check_device_registered( user_id, None, initial_device_display_name, ) old_device_id = await self.store.store_dehydrated_device( user_id, device_id, device_data ) if old_device_id is not None: await self.delete_device(user_id, old_device_id) return device_id async def get_dehydrated_device( self, user_id: str ) -> Optional[Tuple[str, JsonDict]]: """Retrieve the information for a dehydrated device. Args: user_id: the user whose dehydrated device we are looking for Returns: a tuple whose first item is the device ID, and the second item is the dehydrated device information """ return await self.store.get_dehydrated_device(user_id) async def rehydrate_device( self, user_id: str, access_token: str, device_id: str ) -> dict: """Process a rehydration request from the user. Args: user_id: the user who is rehydrating the device access_token: the access token used for the request device_id: the ID of the device that will be rehydrated Returns: a dict containing {"success": True} """ success = await self.store.remove_dehydrated_device(user_id, device_id) if not success: raise errors.NotFoundError() # If the dehydrated device was successfully deleted (the device ID # matched the stored dehydrated device), then modify the access # token to use the dehydrated device's ID and copy the old device # display name to the dehydrated device, and destroy the old device # ID old_device_id = await self.store.set_device_for_access_token( access_token, device_id ) old_device = await self.store.get_device(user_id, old_device_id) if old_device is None: raise errors.NotFoundError() await self.store.update_device(user_id, device_id, old_device["display_name"]) # can't call self.delete_device because that will clobber the # access token so call the storage layer directly await self.store.delete_device(user_id, old_device_id) await self.store.delete_e2e_keys_by_device( user_id=user_id, device_id=old_device_id ) # tell everyone that the old device is gone and that the dehydrated # device has a new display name await self.notify_device_update(user_id, [old_device_id, device_id]) return {"success": True} @wrap_as_background_process("_handle_new_device_update_async") async def _handle_new_device_update_async(self) -> None: """Called when we have a new local device list update that we need to send out over federation. This happens in the background so as not to block the original request that generated the device update. """ if self._handle_new_device_update_is_processing: self._handle_new_device_update_new_data = True return self._handle_new_device_update_is_processing = True # The stream ID we processed previous iteration (if any), and the set of # hosts we've already poked about for this update. This is so that we # don't poke the same remote server about the same update repeatedly. current_stream_id = None hosts_already_sent_to: Set[str] = set() try: while True: self._handle_new_device_update_new_data = False rows = await self.store.get_uncoverted_outbound_room_pokes() if not rows: # If the DB returned nothing then there is nothing left to # do, *unless* a new device list update happened during the # DB query. if self._handle_new_device_update_new_data: continue else: return for user_id, device_id, room_id, stream_id, opentracing_context in rows: joined_user_ids = await self.store.get_users_in_room(room_id) hosts = {get_domain_from_id(u) for u in joined_user_ids} hosts.discard(self.server_name) # Check if we've already sent this update to some hosts if current_stream_id == stream_id: hosts -= hosts_already_sent_to await self.store.add_device_list_outbound_pokes( user_id=user_id, device_id=device_id, room_id=room_id, stream_id=stream_id, hosts=hosts, context=opentracing_context, ) # Notify replication that we've updated the device list stream. self.notifier.notify_replication() if hosts: logger.info( "Sending device list update notif for %r to: %r", user_id, hosts, ) for host in hosts: self.federation_sender.send_device_messages( host, immediate=False ) log_kv( {"message": "sent device update to host", "host": host} ) if current_stream_id != stream_id: # Clear the set of hosts we've already sent to as we're # processing a new update. hosts_already_sent_to.clear() hosts_already_sent_to.update(hosts) current_stream_id = stream_id finally: self._handle_new_device_update_is_processing = False def _update_device_from_client_ips( device: JsonDict, client_ips: Mapping[Tuple[str, str], Mapping[str, Any]] ) -> None: ip = client_ips.get((device["user_id"], device["device_id"]), {}) device.update({"last_seen_ts": ip.get("last_seen"), "last_seen_ip": ip.get("ip")}) class DeviceListUpdater: "Handles incoming device list updates from federation and updates the DB" def __init__(self, hs: "HomeServer", device_handler: DeviceHandler): self.store = hs.get_datastores().main self.federation = hs.get_federation_client() self.clock = hs.get_clock() self.device_handler = device_handler self._remote_edu_linearizer = Linearizer(name="remote_device_list") # user_id -> list of updates waiting to be handled. self._pending_updates: Dict[ str, List[Tuple[str, str, Iterable[str], JsonDict]] ] = {} # Recently seen stream ids. We don't bother keeping these in the DB, # but they're useful to have them about to reduce the number of spurious # resyncs. self._seen_updates: ExpiringCache[str, Set[str]] = ExpiringCache( cache_name="device_update_edu", clock=self.clock, max_len=10000, expiry_ms=30 * 60 * 1000, iterable=True, ) # Attempt to resync out of sync device lists every 30s. self._resync_retry_in_progress = False self.clock.looping_call( run_as_background_process, 30 * 1000, func=self._maybe_retry_device_resync, desc="_maybe_retry_device_resync", ) @trace async def incoming_device_list_update( self, origin: str, edu_content: JsonDict ) -> None: """Called on incoming device list update from federation. Responsible for parsing the EDU and adding to pending updates list. """ set_tag("origin", origin) set_tag("edu_content", edu_content) user_id = edu_content.pop("user_id") device_id = edu_content.pop("device_id") stream_id = str(edu_content.pop("stream_id")) # They may come as ints prev_ids = edu_content.pop("prev_id", []) prev_ids = [str(p) for p in prev_ids] # They may come as ints if get_domain_from_id(user_id) != origin: # TODO: Raise? logger.warning( "Got device list update edu for %r/%r from %r", user_id, device_id, origin, ) set_tag("error", True) log_kv( { "message": "Got a device list update edu from a user and " "device which does not match the origin of the request.", "user_id": user_id, "device_id": device_id, } ) return room_ids = await self.store.get_rooms_for_user(user_id) if not room_ids: # We don't share any rooms with this user. Ignore update, as we # probably won't get any further updates. set_tag("error", True) log_kv( { "message": "Got an update from a user for which " "we don't share any rooms", "other user_id": user_id, } ) logger.warning( "Got device list update edu for %r/%r, but don't share a room", user_id, device_id, ) return logger.debug("Received device list update for %r/%r", user_id, device_id) self._pending_updates.setdefault(user_id, []).append( (device_id, stream_id, prev_ids, edu_content) ) await self._handle_device_updates(user_id) @measure_func("_incoming_device_list_update") async def _handle_device_updates(self, user_id: str) -> None: "Actually handle pending updates." async with self._remote_edu_linearizer.queue(user_id): pending_updates = self._pending_updates.pop(user_id, []) if not pending_updates: # This can happen since we batch updates return for device_id, stream_id, prev_ids, _ in pending_updates: logger.debug( "Handling update %r/%r, ID: %r, prev: %r ", user_id, device_id, stream_id, prev_ids, ) # Given a list of updates we check if we need to resync. This # happens if we've missed updates. resync = await self._need_to_do_resync(user_id, pending_updates) if logger.isEnabledFor(logging.INFO): logger.info( "Received device list update for %s, requiring resync: %s. Devices: %s", user_id, resync, ", ".join(u[0] for u in pending_updates), ) if resync: await self.user_device_resync(user_id) else: # Simply update the single device, since we know that is the only # change (because of the single prev_id matching the current cache) for device_id, stream_id, _, content in pending_updates: await self.store.update_remote_device_list_cache_entry( user_id, device_id, content, stream_id ) await self.device_handler.notify_device_update( user_id, [device_id for device_id, _, _, _ in pending_updates] ) self._seen_updates.setdefault(user_id, set()).update( stream_id for _, stream_id, _, _ in pending_updates ) async def _need_to_do_resync( self, user_id: str, updates: Iterable[Tuple[str, str, Iterable[str], JsonDict]] ) -> bool: """Given a list of updates for a user figure out if we need to do a full resync, or whether we have enough data that we can just apply the delta. """ seen_updates: Set[str] = self._seen_updates.get(user_id, set()) extremity = await self.store.get_device_list_last_stream_id_for_remote(user_id) logger.debug("Current extremity for %r: %r", user_id, extremity) stream_id_in_updates = set() # stream_ids in updates list for _, stream_id, prev_ids, _ in updates: if not prev_ids: # We always do a resync if there are no previous IDs return True for prev_id in prev_ids: if prev_id == extremity: continue elif prev_id in seen_updates: continue elif prev_id in stream_id_in_updates: continue else: return True stream_id_in_updates.add(stream_id) return False @trace async def _maybe_retry_device_resync(self) -> None: """Retry to resync device lists that are out of sync, except if another retry is in progress. """ if self._resync_retry_in_progress: return try: # Prevent another call of this function to retry resyncing device lists so # we don't send too many requests. self._resync_retry_in_progress = True # Get all of the users that need resyncing. need_resync = await self.store.get_user_ids_requiring_device_list_resync() # Iterate over the set of user IDs. for user_id in need_resync: try: # Try to resync the current user's devices list. result = await self.user_device_resync( user_id=user_id, mark_failed_as_stale=False, ) # user_device_resync only returns a result if it managed to # successfully resync and update the database. Updating the table # of users requiring resync isn't necessary here as # user_device_resync already does it (through # self.store.update_remote_device_list_cache). if result: logger.debug( "Successfully resynced the device list for %s", user_id, ) except Exception as e: # If there was an issue resyncing this user, e.g. if the remote # server sent a malformed result, just log the error instead of # aborting all the subsequent resyncs. logger.debug( "Could not resync the device list for %s: %s", user_id, e, ) finally: # Allow future calls to retry resyncinc out of sync device lists. self._resync_retry_in_progress = False async def user_device_resync( self, user_id: str, mark_failed_as_stale: bool = True ) -> Optional[JsonDict]: """Fetches all devices for a user and updates the device cache with them. Args: user_id: The user's id whose device_list will be updated. mark_failed_as_stale: Whether to mark the user's device list as stale if the attempt to resync failed. Returns: A dict with device info as under the "devices" in the result of this request: https://matrix.org/docs/spec/server_server/r0.1.2#get-matrix-federation-v1-user-devices-userid """ logger.debug("Attempting to resync the device list for %s", user_id) log_kv({"message": "Doing resync to update device list."}) # Fetch all devices for the user. origin = get_domain_from_id(user_id) try: result = await self.federation.query_user_devices(origin, user_id) except NotRetryingDestination: if mark_failed_as_stale: # Mark the remote user's device list as stale so we know we need to retry # it later. await self.store.mark_remote_user_device_cache_as_stale(user_id) return None except (RequestSendFailed, HttpResponseException) as e: logger.warning( "Failed to handle device list update for %s: %s", user_id, e, ) if mark_failed_as_stale: # Mark the remote user's device list as stale so we know we need to retry # it later. await self.store.mark_remote_user_device_cache_as_stale(user_id) # We abort on exceptions rather than accepting the update # as otherwise synapse will 'forget' that its device list # is out of date. If we bail then we will retry the resync # next time we get a device list update for this user_id. # This makes it more likely that the device lists will # eventually become consistent. return None except FederationDeniedError as e: set_tag("error", True) log_kv({"reason": "FederationDeniedError"}) logger.info(e) return None except Exception as e: set_tag("error", True) log_kv( {"message": "Exception raised by federation request", "exception": e} ) logger.exception("Failed to handle device list update for %s", user_id) if mark_failed_as_stale: # Mark the remote user's device list as stale so we know we need to retry # it later. await self.store.mark_remote_user_device_cache_as_stale(user_id) return None log_kv({"result": result}) stream_id = result["stream_id"] devices = result["devices"] # Get the master key and the self-signing key for this user if provided in the # response (None if not in the response). # The response will not contain the user signing key, as this key is only used by # its owner, thus it doesn't make sense to send it over federation. master_key = result.get("master_key") self_signing_key = result.get("self_signing_key") ignore_devices = False # If the remote server has more than ~1000 devices for this user # we assume that something is going horribly wrong (e.g. a bot # that logs in and creates a new device every time it tries to # send a message). Maintaining lots of devices per user in the # cache can cause serious performance issues as if this request # takes more than 60s to complete, internal replication from the # inbound federation worker to the synapse master may time out # causing the inbound federation to fail and causing the remote # server to retry, causing a DoS. So in this scenario we give # up on storing the total list of devices and only handle the # delta instead. if len(devices) > 1000: logger.warning( "Ignoring device list snapshot for %s as it has >1K devs (%d)", user_id, len(devices), ) devices = [] ignore_devices = True else: prev_stream_id = await self.store.get_device_list_last_stream_id_for_remote( user_id ) cached_devices = await self.store.get_cached_devices_for_user(user_id) # To ensure that a user with no devices is cached, we skip the resync only # if we have a stream_id from previously writing a cache entry. if prev_stream_id is not None and cached_devices == { d["device_id"]: d for d in devices }: logging.info( "Skipping device list resync for %s, as our cache matches already", user_id, ) devices = [] ignore_devices = True for device in devices: logger.debug( "Handling resync update %r/%r, ID: %r", user_id, device["device_id"], stream_id, ) if not ignore_devices: await self.store.update_remote_device_list_cache( user_id, devices, stream_id ) # mark the cache as valid, whether or not we actually processed any device # list updates. await self.store.mark_remote_user_device_cache_as_valid(user_id) device_ids = [device["device_id"] for device in devices] # Handle cross-signing keys. cross_signing_device_ids = await self.process_cross_signing_key_update( user_id, master_key, self_signing_key, ) device_ids = device_ids + cross_signing_device_ids if device_ids: await self.device_handler.notify_device_update(user_id, device_ids) # We clobber the seen updates since we've re-synced from a given # point. self._seen_updates[user_id] = {stream_id} return result async def process_cross_signing_key_update( self, user_id: str, master_key: Optional[JsonDict], self_signing_key: Optional[JsonDict], ) -> List[str]: """Process the given new master and self-signing key for the given remote user. Args: user_id: The ID of the user these keys are for. master_key: The dict of the cross-signing master key as returned by the remote server. self_signing_key: The dict of the cross-signing self-signing key as returned by the remote server. Return: The device IDs for the given keys. """ device_ids = [] current_keys_map = await self.store.get_e2e_cross_signing_keys_bulk([user_id]) current_keys = current_keys_map.get(user_id) or {} if master_key and master_key != current_keys.get("master"): await self.store.set_e2e_cross_signing_key(user_id, "master", master_key) _, verify_key = get_verify_key_from_cross_signing_key(master_key) # verify_key is a VerifyKey from signedjson, which uses # .version to denote the portion of the key ID after the # algorithm and colon, which is the device ID device_ids.append(verify_key.version) if self_signing_key and self_signing_key != current_keys.get("self_signing"): await self.store.set_e2e_cross_signing_key( user_id, "self_signing", self_signing_key ) _, verify_key = get_verify_key_from_cross_signing_key(self_signing_key) device_ids.append(verify_key.version) return device_ids