forked-synapse/synapse/handlers/device.py
David Robertson 88a78c6577
Cache empty responses from /user/devices (#11587)
If we've never made a request to a remote homeserver, we should cache the response---even if the response is "this user has no devices".
2022-01-05 13:33:28 +00:00

1040 lines
39 KiB
Python

# 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
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_datastore()
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)
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}
)
pass
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.")
pass
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
users_who_share_room = await self.store.get_users_who_share_room_with_user(
user_id
)
hosts: Set[str] = set()
if self.hs.is_mine_id(user_id):
hosts.update(get_domain_from_id(u) for u in users_who_share_room)
hosts.discard(self.server_name)
set_tag("target_hosts", hosts)
position = await self.store.add_device_change_to_streams(
user_id, device_ids, list(hosts)
)
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
)
room_ids = await self.store.get_rooms_for_user(user_id)
# 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
)
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)
log_kv({"message": "sent device update to host", "host": host})
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}
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_datastore()
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."
with (await 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