1633 lines
65 KiB
Python
1633 lines
65 KiB
Python
# Copyright 2016 OpenMarket Ltd
|
|
# Copyright 2018-2019 New Vector Ltd
|
|
# Copyright 2019 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, Dict, Iterable, List, Mapping, Optional, Tuple
|
|
|
|
import attr
|
|
from canonicaljson import encode_canonical_json
|
|
from signedjson.key import VerifyKey, decode_verify_key_bytes
|
|
from signedjson.sign import SignatureVerifyException, verify_signed_json
|
|
from unpaddedbase64 import decode_base64
|
|
|
|
from twisted.internet import defer
|
|
|
|
from synapse.api.constants import EduTypes
|
|
from synapse.api.errors import CodeMessageException, Codes, NotFoundError, SynapseError
|
|
from synapse.handlers.device import DeviceHandler
|
|
from synapse.logging.context import make_deferred_yieldable, run_in_background
|
|
from synapse.logging.opentracing import log_kv, set_tag, tag_args, trace
|
|
from synapse.types import (
|
|
JsonDict,
|
|
UserID,
|
|
get_domain_from_id,
|
|
get_verify_key_from_cross_signing_key,
|
|
)
|
|
from synapse.util import json_decoder
|
|
from synapse.util.async_helpers import Linearizer, concurrently_execute
|
|
from synapse.util.cancellation import cancellable
|
|
from synapse.util.retryutils import NotRetryingDestination
|
|
|
|
if TYPE_CHECKING:
|
|
from synapse.server import HomeServer
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
class E2eKeysHandler:
|
|
def __init__(self, hs: "HomeServer"):
|
|
self.config = hs.config
|
|
self.store = hs.get_datastores().main
|
|
self.federation = hs.get_federation_client()
|
|
self.device_handler = hs.get_device_handler()
|
|
self._appservice_handler = hs.get_application_service_handler()
|
|
self.is_mine = hs.is_mine
|
|
self.clock = hs.get_clock()
|
|
|
|
federation_registry = hs.get_federation_registry()
|
|
|
|
is_master = hs.config.worker.worker_app is None
|
|
if is_master:
|
|
edu_updater = SigningKeyEduUpdater(hs)
|
|
|
|
# Only register this edu handler on master as it requires writing
|
|
# device updates to the db
|
|
federation_registry.register_edu_handler(
|
|
EduTypes.SIGNING_KEY_UPDATE,
|
|
edu_updater.incoming_signing_key_update,
|
|
)
|
|
# also handle the unstable version
|
|
# FIXME: remove this when enough servers have upgraded
|
|
federation_registry.register_edu_handler(
|
|
EduTypes.UNSTABLE_SIGNING_KEY_UPDATE,
|
|
edu_updater.incoming_signing_key_update,
|
|
)
|
|
|
|
# doesn't really work as part of the generic query API, because the
|
|
# query request requires an object POST, but we abuse the
|
|
# "query handler" interface.
|
|
federation_registry.register_query_handler(
|
|
"client_keys", self.on_federation_query_client_keys
|
|
)
|
|
|
|
# Limit the number of in-flight requests from a single device.
|
|
self._query_devices_linearizer = Linearizer(
|
|
name="query_devices",
|
|
max_count=10,
|
|
)
|
|
|
|
self._query_appservices_for_otks = (
|
|
hs.config.experimental.msc3983_appservice_otk_claims
|
|
)
|
|
self._query_appservices_for_keys = (
|
|
hs.config.experimental.msc3984_appservice_key_query
|
|
)
|
|
|
|
@trace
|
|
@cancellable
|
|
async def query_devices(
|
|
self,
|
|
query_body: JsonDict,
|
|
timeout: int,
|
|
from_user_id: str,
|
|
from_device_id: Optional[str],
|
|
) -> JsonDict:
|
|
"""Handle a device key query from a client
|
|
|
|
{
|
|
"device_keys": {
|
|
"<user_id>": ["<device_id>"]
|
|
}
|
|
}
|
|
->
|
|
{
|
|
"device_keys": {
|
|
"<user_id>": {
|
|
"<device_id>": {
|
|
...
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
Args:
|
|
from_user_id: the user making the query. This is used when
|
|
adding cross-signing signatures to limit what signatures users
|
|
can see.
|
|
from_device_id: the device making the query. This is used to limit
|
|
the number of in-flight queries at a time.
|
|
"""
|
|
async with self._query_devices_linearizer.queue((from_user_id, from_device_id)):
|
|
device_keys_query: Dict[str, List[str]] = query_body.get("device_keys", {})
|
|
|
|
# separate users by domain.
|
|
# make a map from domain to user_id to device_ids
|
|
local_query = {}
|
|
remote_queries = {}
|
|
|
|
for user_id, device_ids in device_keys_query.items():
|
|
# we use UserID.from_string to catch invalid user ids
|
|
if self.is_mine(UserID.from_string(user_id)):
|
|
local_query[user_id] = device_ids
|
|
else:
|
|
remote_queries[user_id] = device_ids
|
|
|
|
set_tag("local_key_query", str(local_query))
|
|
set_tag("remote_key_query", str(remote_queries))
|
|
|
|
# First get local devices.
|
|
# A map of destination -> failure response.
|
|
failures: Dict[str, JsonDict] = {}
|
|
results = {}
|
|
if local_query:
|
|
local_result = await self.query_local_devices(local_query)
|
|
for user_id, keys in local_result.items():
|
|
if user_id in local_query:
|
|
results[user_id] = keys
|
|
|
|
# Get cached cross-signing keys
|
|
cross_signing_keys = await self.get_cross_signing_keys_from_cache(
|
|
device_keys_query, from_user_id
|
|
)
|
|
|
|
# Now attempt to get any remote devices from our local cache.
|
|
# A map of destination -> user ID -> device IDs.
|
|
remote_queries_not_in_cache: Dict[str, Dict[str, Iterable[str]]] = {}
|
|
if remote_queries:
|
|
user_ids = set()
|
|
user_and_device_ids: List[Tuple[str, str]] = []
|
|
for user_id, device_ids in remote_queries.items():
|
|
if device_ids:
|
|
user_and_device_ids.extend(
|
|
(user_id, device_id) for device_id in device_ids
|
|
)
|
|
else:
|
|
user_ids.add(user_id)
|
|
|
|
(
|
|
user_ids_not_in_cache,
|
|
remote_results,
|
|
) = await self.store.get_user_devices_from_cache(
|
|
user_ids, user_and_device_ids
|
|
)
|
|
|
|
# Check that the homeserver still shares a room with all cached users.
|
|
# Note that this check may be slightly racy when a remote user leaves a
|
|
# room after we have fetched their cached device list. In the worst case
|
|
# we will do extra federation queries for devices that we had cached.
|
|
cached_users = set(remote_results.keys())
|
|
valid_cached_users = (
|
|
await self.store.get_users_server_still_shares_room_with(
|
|
remote_results.keys()
|
|
)
|
|
)
|
|
invalid_cached_users = cached_users - valid_cached_users
|
|
if invalid_cached_users:
|
|
# Fix up results. If we get here, it means there was either a bug in
|
|
# device list tracking, or we hit the race mentioned above.
|
|
# TODO: In practice, this path is hit fairly often in existing
|
|
# deployments when clients query the keys of departed remote
|
|
# users. A background update to mark the appropriate device
|
|
# lists as unsubscribed is needed.
|
|
# https://github.com/matrix-org/synapse/issues/13651
|
|
# Note that this currently introduces a failure mode when clients
|
|
# are trying to decrypt old messages from a remote user whose
|
|
# homeserver is no longer available. We may want to consider falling
|
|
# back to the cached data when we fail to retrieve a device list
|
|
# over federation for such remote users.
|
|
user_ids_not_in_cache.update(invalid_cached_users)
|
|
for invalid_user_id in invalid_cached_users:
|
|
remote_results.pop(invalid_user_id)
|
|
|
|
for user_id, devices in remote_results.items():
|
|
user_devices = results.setdefault(user_id, {})
|
|
for device_id, device in devices.items():
|
|
keys = device.get("keys", None)
|
|
device_display_name = device.get("device_display_name", None)
|
|
if keys:
|
|
result = dict(keys)
|
|
unsigned = result.setdefault("unsigned", {})
|
|
if device_display_name:
|
|
unsigned["device_display_name"] = device_display_name
|
|
user_devices[device_id] = result
|
|
|
|
# check for missing cross-signing keys.
|
|
for user_id in remote_queries.keys():
|
|
cached_cross_master = user_id in cross_signing_keys["master_keys"]
|
|
cached_cross_selfsigning = (
|
|
user_id in cross_signing_keys["self_signing_keys"]
|
|
)
|
|
|
|
# check if we are missing only one of cross-signing master or
|
|
# self-signing key, but the other one is cached.
|
|
# as we need both, this will issue a federation request.
|
|
# if we don't have any of the keys, either the user doesn't have
|
|
# cross-signing set up, or the cached device list
|
|
# is not (yet) updated.
|
|
if cached_cross_master ^ cached_cross_selfsigning:
|
|
user_ids_not_in_cache.add(user_id)
|
|
|
|
# add those users to the list to fetch over federation.
|
|
for user_id in user_ids_not_in_cache:
|
|
domain = get_domain_from_id(user_id)
|
|
r = remote_queries_not_in_cache.setdefault(domain, {})
|
|
r[user_id] = remote_queries[user_id]
|
|
|
|
# Now fetch any devices that we don't have in our cache
|
|
# TODO It might make sense to propagate cancellations into the
|
|
# deferreds which are querying remote homeservers.
|
|
logger.debug(
|
|
"%d destinations to query devices for", len(remote_queries_not_in_cache)
|
|
)
|
|
|
|
async def _query(
|
|
destination_queries: Tuple[str, Dict[str, Iterable[str]]]
|
|
) -> None:
|
|
destination, queries = destination_queries
|
|
return await self._query_devices_for_destination(
|
|
results,
|
|
cross_signing_keys,
|
|
failures,
|
|
destination,
|
|
queries,
|
|
timeout,
|
|
)
|
|
|
|
await concurrently_execute(
|
|
_query,
|
|
remote_queries_not_in_cache.items(),
|
|
10,
|
|
delay_cancellation=True,
|
|
)
|
|
|
|
ret = {"device_keys": results, "failures": failures}
|
|
|
|
ret.update(cross_signing_keys)
|
|
|
|
return ret
|
|
|
|
@trace
|
|
async def _query_devices_for_destination(
|
|
self,
|
|
results: JsonDict,
|
|
cross_signing_keys: JsonDict,
|
|
failures: Dict[str, JsonDict],
|
|
destination: str,
|
|
destination_query: Dict[str, Iterable[str]],
|
|
timeout: int,
|
|
) -> None:
|
|
"""This is called when we are querying the device list of a user on
|
|
a remote homeserver and their device list is not in the device list
|
|
cache. If we share a room with this user and we're not querying for
|
|
specific user we will update the cache with their device list.
|
|
|
|
Args:
|
|
results: A map from user ID to their device keys, which gets
|
|
updated with the newly fetched keys.
|
|
cross_signing_keys: Map from user ID to their cross signing keys,
|
|
which gets updated with the newly fetched keys.
|
|
failures: Map of destinations to failures that have occurred while
|
|
attempting to fetch keys.
|
|
destination: The remote server to query
|
|
destination_query: The query dict of devices to query the remote
|
|
server for.
|
|
timeout: The timeout for remote HTTP requests.
|
|
"""
|
|
|
|
# We first consider whether we wish to update the device list cache with
|
|
# the users device list. We want to track a user's devices when the
|
|
# authenticated user shares a room with the queried user and the query
|
|
# has not specified a particular device.
|
|
# If we update the cache for the queried user we remove them from further
|
|
# queries. We use the more efficient batched query_client_keys for all
|
|
# remaining users
|
|
user_ids_updated = []
|
|
|
|
# Perform a user device resync for each user only once and only as long as:
|
|
# - they have an empty device_list
|
|
# - they are in some rooms that this server can see
|
|
users_to_resync_devices = {
|
|
user_id
|
|
for (user_id, device_list) in destination_query.items()
|
|
if (not device_list) and (await self.store.get_rooms_for_user(user_id))
|
|
}
|
|
|
|
logger.debug(
|
|
"%d users to resync devices for from destination %s",
|
|
len(users_to_resync_devices),
|
|
destination,
|
|
)
|
|
|
|
try:
|
|
user_resync_results = (
|
|
await self.device_handler.device_list_updater.multi_user_device_resync(
|
|
list(users_to_resync_devices)
|
|
)
|
|
)
|
|
for user_id in users_to_resync_devices:
|
|
resync_results = user_resync_results[user_id]
|
|
|
|
if resync_results is None:
|
|
# TODO: It's weird that we'll store a failure against a
|
|
# destination, yet continue processing users from that
|
|
# destination.
|
|
# We might want to consider changing this, but for now
|
|
# I'm leaving it as I found it.
|
|
failures[destination] = _exception_to_failure(
|
|
ValueError(f"Device resync failed for {user_id!r}")
|
|
)
|
|
continue
|
|
|
|
# Add the device keys to the results.
|
|
user_devices = resync_results["devices"]
|
|
user_results = results.setdefault(user_id, {})
|
|
for device in user_devices:
|
|
user_results[device["device_id"]] = device["keys"]
|
|
user_ids_updated.append(user_id)
|
|
|
|
# Add any cross signing keys to the results.
|
|
master_key = resync_results.get("master_key")
|
|
self_signing_key = resync_results.get("self_signing_key")
|
|
|
|
if master_key:
|
|
cross_signing_keys["master_keys"][user_id] = master_key
|
|
|
|
if self_signing_key:
|
|
cross_signing_keys["self_signing_keys"][user_id] = self_signing_key
|
|
except Exception as e:
|
|
failures[destination] = _exception_to_failure(e)
|
|
|
|
if len(destination_query) == len(user_ids_updated):
|
|
# We've updated all the users in the query and we do not need to
|
|
# make any further remote calls.
|
|
return
|
|
|
|
# Remove all the users from the query which we have updated
|
|
for user_id in user_ids_updated:
|
|
destination_query.pop(user_id)
|
|
|
|
try:
|
|
remote_result = await self.federation.query_client_keys(
|
|
destination, {"device_keys": destination_query}, timeout=timeout
|
|
)
|
|
|
|
for user_id, keys in remote_result["device_keys"].items():
|
|
if user_id in destination_query:
|
|
results[user_id] = keys
|
|
|
|
if "master_keys" in remote_result:
|
|
for user_id, key in remote_result["master_keys"].items():
|
|
if user_id in destination_query:
|
|
cross_signing_keys["master_keys"][user_id] = key
|
|
|
|
if "self_signing_keys" in remote_result:
|
|
for user_id, key in remote_result["self_signing_keys"].items():
|
|
if user_id in destination_query:
|
|
cross_signing_keys["self_signing_keys"][user_id] = key
|
|
|
|
except Exception as e:
|
|
failure = _exception_to_failure(e)
|
|
failures[destination] = failure
|
|
set_tag("error", True)
|
|
set_tag("reason", str(failure))
|
|
|
|
return
|
|
|
|
@cancellable
|
|
async def get_cross_signing_keys_from_cache(
|
|
self, query: Iterable[str], from_user_id: Optional[str]
|
|
) -> Dict[str, Dict[str, dict]]:
|
|
"""Get cross-signing keys for users from the database
|
|
|
|
Args:
|
|
query: an iterable of user IDs. A dict whose keys
|
|
are user IDs satisfies this, so the query format used for
|
|
query_devices can be used here.
|
|
from_user_id: the user making the query. This is used when
|
|
adding cross-signing signatures to limit what signatures users
|
|
can see.
|
|
|
|
Returns:
|
|
A map from (master_keys|self_signing_keys|user_signing_keys) -> user_id -> key
|
|
"""
|
|
master_keys = {}
|
|
self_signing_keys = {}
|
|
user_signing_keys = {}
|
|
|
|
user_ids = list(query)
|
|
|
|
keys = await self.store.get_e2e_cross_signing_keys_bulk(user_ids, from_user_id)
|
|
|
|
for user_id, user_info in keys.items():
|
|
if user_info is None:
|
|
continue
|
|
if "master" in user_info:
|
|
master_keys[user_id] = user_info["master"]
|
|
if "self_signing" in user_info:
|
|
self_signing_keys[user_id] = user_info["self_signing"]
|
|
|
|
# users can see other users' master and self-signing keys, but can
|
|
# only see their own user-signing keys
|
|
if from_user_id:
|
|
from_user_key = keys.get(from_user_id)
|
|
if from_user_key and "user_signing" in from_user_key:
|
|
user_signing_keys[from_user_id] = from_user_key["user_signing"]
|
|
|
|
return {
|
|
"master_keys": master_keys,
|
|
"self_signing_keys": self_signing_keys,
|
|
"user_signing_keys": user_signing_keys,
|
|
}
|
|
|
|
@trace
|
|
@cancellable
|
|
async def query_local_devices(
|
|
self,
|
|
query: Mapping[str, Optional[List[str]]],
|
|
include_displaynames: bool = True,
|
|
) -> Dict[str, Dict[str, dict]]:
|
|
"""Get E2E device keys for local users
|
|
|
|
Args:
|
|
query: map from user_id to a list
|
|
of devices to query (None for all devices)
|
|
include_displaynames: Whether to include device displaynames in the returned
|
|
device details.
|
|
|
|
Returns:
|
|
A map from user_id -> device_id -> device details
|
|
"""
|
|
set_tag("local_query", str(query))
|
|
local_query: List[Tuple[str, Optional[str]]] = []
|
|
|
|
result_dict: Dict[str, Dict[str, dict]] = {}
|
|
for user_id, device_ids in query.items():
|
|
# we use UserID.from_string to catch invalid user ids
|
|
if not self.is_mine(UserID.from_string(user_id)):
|
|
logger.warning("Request for keys for non-local user %s", user_id)
|
|
log_kv(
|
|
{
|
|
"message": "Requested a local key for a user which"
|
|
" was not local to the homeserver",
|
|
"user_id": user_id,
|
|
}
|
|
)
|
|
set_tag("error", True)
|
|
raise SynapseError(400, "Not a user here")
|
|
|
|
if not device_ids:
|
|
local_query.append((user_id, None))
|
|
else:
|
|
for device_id in device_ids:
|
|
local_query.append((user_id, device_id))
|
|
|
|
# make sure that each queried user appears in the result dict
|
|
result_dict[user_id] = {}
|
|
|
|
results = await self.store.get_e2e_device_keys_for_cs_api(
|
|
local_query, include_displaynames
|
|
)
|
|
|
|
# Check if the application services have any additional results.
|
|
if self._query_appservices_for_keys:
|
|
# Query the appservices for any keys.
|
|
appservice_results = await self._appservice_handler.query_keys(query)
|
|
|
|
# Merge results, overriding with what the appservice returned.
|
|
for user_id, devices in appservice_results.get("device_keys", {}).items():
|
|
# Copy the appservice device info over the homeserver device info, but
|
|
# don't completely overwrite it.
|
|
results.setdefault(user_id, {}).update(devices)
|
|
|
|
# TODO Handle cross-signing keys.
|
|
|
|
# Build the result structure
|
|
for user_id, device_keys in results.items():
|
|
for device_id, device_info in device_keys.items():
|
|
result_dict[user_id][device_id] = device_info
|
|
|
|
log_kv(results)
|
|
return result_dict
|
|
|
|
async def on_federation_query_client_keys(
|
|
self, query_body: Dict[str, Dict[str, Optional[List[str]]]]
|
|
) -> JsonDict:
|
|
"""Handle a device key query from a federated server:
|
|
|
|
Handles the path: GET /_matrix/federation/v1/users/keys/query
|
|
|
|
Args:
|
|
query_body: The body of the query request. Should contain a key
|
|
"device_keys" that map to a dictionary of user ID's -> list of
|
|
device IDs. If the list of device IDs is empty, all devices of
|
|
that user will be queried.
|
|
|
|
Returns:
|
|
A json dictionary containing the following:
|
|
- device_keys: A dictionary containing the requested device information.
|
|
- master_keys: An optional dictionary of user ID -> master cross-signing
|
|
key info.
|
|
- self_signing_key: An optional dictionary of user ID -> self-signing
|
|
key info.
|
|
"""
|
|
device_keys_query: Dict[str, Optional[List[str]]] = query_body.get(
|
|
"device_keys", {}
|
|
)
|
|
res = await self.query_local_devices(
|
|
device_keys_query,
|
|
include_displaynames=(
|
|
self.config.federation.allow_device_name_lookup_over_federation
|
|
),
|
|
)
|
|
ret = {"device_keys": res}
|
|
|
|
# add in the cross-signing keys
|
|
cross_signing_keys = await self.get_cross_signing_keys_from_cache(
|
|
device_keys_query, None
|
|
)
|
|
|
|
ret.update(cross_signing_keys)
|
|
|
|
return ret
|
|
|
|
async def claim_local_one_time_keys(
|
|
self,
|
|
local_query: List[Tuple[str, str, str, int]],
|
|
always_include_fallback_keys: bool,
|
|
) -> Iterable[Dict[str, Dict[str, Dict[str, JsonDict]]]]:
|
|
"""Claim one time keys for local users.
|
|
|
|
1. Attempt to claim OTKs from the database.
|
|
2. Ask application services if they provide OTKs.
|
|
3. Attempt to fetch fallback keys from the database.
|
|
|
|
Args:
|
|
local_query: An iterable of tuples of (user ID, device ID, algorithm).
|
|
always_include_fallback_keys: True to always include fallback keys.
|
|
|
|
Returns:
|
|
An iterable of maps of user ID -> a map device ID -> a map of key ID -> JSON bytes.
|
|
"""
|
|
|
|
# Cap the number of OTKs that can be claimed at once to avoid abuse.
|
|
local_query = [
|
|
(user_id, device_id, algorithm, min(count, 5))
|
|
for user_id, device_id, algorithm, count in local_query
|
|
]
|
|
|
|
otk_results, not_found = await self.store.claim_e2e_one_time_keys(local_query)
|
|
|
|
# If the application services have not provided any keys via the C-S
|
|
# API, query it directly for one-time keys.
|
|
if self._query_appservices_for_otks:
|
|
# TODO Should this query for fallback keys of uploaded OTKs if
|
|
# always_include_fallback_keys is True? The MSC is ambiguous.
|
|
(
|
|
appservice_results,
|
|
not_found,
|
|
) = await self._appservice_handler.claim_e2e_one_time_keys(not_found)
|
|
else:
|
|
appservice_results = {}
|
|
|
|
# Calculate which user ID / device ID / algorithm tuples to get fallback
|
|
# keys for. This can be either only missing results *or* all results
|
|
# (which don't already have a fallback key).
|
|
if always_include_fallback_keys:
|
|
# Build the fallback query as any part of the original query where
|
|
# the appservice didn't respond with a fallback key.
|
|
fallback_query = []
|
|
|
|
# Iterate each item in the original query and search the results
|
|
# from the appservice for that user ID / device ID. If it is found,
|
|
# check if any of the keys match the requested algorithm & are a
|
|
# fallback key.
|
|
for user_id, device_id, algorithm, _count in local_query:
|
|
# Check if the appservice responded for this query.
|
|
as_result = appservice_results.get(user_id, {}).get(device_id, {})
|
|
found_otk = False
|
|
for key_id, key_json in as_result.items():
|
|
if key_id.startswith(f"{algorithm}:"):
|
|
# A OTK or fallback key was found for this query.
|
|
found_otk = True
|
|
# A fallback key was found for this query, no need to
|
|
# query further.
|
|
if key_json.get("fallback", False):
|
|
break
|
|
|
|
else:
|
|
# No fallback key was found from appservices, query for it.
|
|
# Only mark the fallback key as used if no OTK was found
|
|
# (from either the database or appservices).
|
|
mark_as_used = not found_otk and not any(
|
|
key_id.startswith(f"{algorithm}:")
|
|
for key_id in otk_results.get(user_id, {})
|
|
.get(device_id, {})
|
|
.keys()
|
|
)
|
|
# Note that it doesn't make sense to request more than 1 fallback key
|
|
# per (user_id, device_id, algorithm).
|
|
fallback_query.append((user_id, device_id, algorithm, mark_as_used))
|
|
|
|
else:
|
|
# All fallback keys get marked as used.
|
|
fallback_query = [
|
|
# Note that it doesn't make sense to request more than 1 fallback key
|
|
# per (user_id, device_id, algorithm).
|
|
(user_id, device_id, algorithm, True)
|
|
for user_id, device_id, algorithm, count in not_found
|
|
]
|
|
|
|
# For each user that does not have a one-time keys available, see if
|
|
# there is a fallback key.
|
|
fallback_results = await self.store.claim_e2e_fallback_keys(fallback_query)
|
|
|
|
# Return the results in order, each item from the input query should
|
|
# only appear once in the combined list.
|
|
return (otk_results, appservice_results, fallback_results)
|
|
|
|
@trace
|
|
async def claim_one_time_keys(
|
|
self,
|
|
query: Dict[str, Dict[str, Dict[str, int]]],
|
|
timeout: Optional[int],
|
|
always_include_fallback_keys: bool,
|
|
) -> JsonDict:
|
|
local_query: List[Tuple[str, str, str, int]] = []
|
|
remote_queries: Dict[str, Dict[str, Dict[str, Dict[str, int]]]] = {}
|
|
|
|
for user_id, one_time_keys in query.items():
|
|
# we use UserID.from_string to catch invalid user ids
|
|
if self.is_mine(UserID.from_string(user_id)):
|
|
for device_id, algorithms in one_time_keys.items():
|
|
for algorithm, count in algorithms.items():
|
|
local_query.append((user_id, device_id, algorithm, count))
|
|
else:
|
|
domain = get_domain_from_id(user_id)
|
|
remote_queries.setdefault(domain, {})[user_id] = one_time_keys
|
|
|
|
set_tag("local_key_query", str(local_query))
|
|
set_tag("remote_key_query", str(remote_queries))
|
|
|
|
results = await self.claim_local_one_time_keys(
|
|
local_query, always_include_fallback_keys
|
|
)
|
|
|
|
# A map of user ID -> device ID -> key ID -> key.
|
|
json_result: Dict[str, Dict[str, Dict[str, JsonDict]]] = {}
|
|
for result in results:
|
|
for user_id, device_keys in result.items():
|
|
for device_id, keys in device_keys.items():
|
|
for key_id, key in keys.items():
|
|
json_result.setdefault(user_id, {}).setdefault(
|
|
device_id, {}
|
|
).update({key_id: key})
|
|
|
|
# Remote failures.
|
|
failures: Dict[str, JsonDict] = {}
|
|
|
|
@trace
|
|
async def claim_client_keys(destination: str) -> None:
|
|
set_tag("destination", destination)
|
|
device_keys = remote_queries[destination]
|
|
try:
|
|
remote_result = await self.federation.claim_client_keys(
|
|
destination, device_keys, timeout=timeout
|
|
)
|
|
for user_id, keys in remote_result["one_time_keys"].items():
|
|
if user_id in device_keys:
|
|
json_result[user_id] = keys
|
|
|
|
except Exception as e:
|
|
failure = _exception_to_failure(e)
|
|
failures[destination] = failure
|
|
set_tag("error", True)
|
|
set_tag("reason", str(failure))
|
|
|
|
await make_deferred_yieldable(
|
|
defer.gatherResults(
|
|
[
|
|
run_in_background(claim_client_keys, destination)
|
|
for destination in remote_queries
|
|
],
|
|
consumeErrors=True,
|
|
)
|
|
)
|
|
|
|
logger.info(
|
|
"Claimed one-time-keys: %s",
|
|
",".join(
|
|
(
|
|
"%s for %s:%s" % (key_id, user_id, device_id)
|
|
for user_id, user_keys in json_result.items()
|
|
for device_id, device_keys in user_keys.items()
|
|
for key_id, _ in device_keys.items()
|
|
)
|
|
),
|
|
)
|
|
|
|
log_kv({"one_time_keys": json_result, "failures": failures})
|
|
return {"one_time_keys": json_result, "failures": failures}
|
|
|
|
@tag_args
|
|
async def upload_keys_for_user(
|
|
self, user_id: str, device_id: str, keys: JsonDict
|
|
) -> JsonDict:
|
|
# This can only be called from the main process.
|
|
assert isinstance(self.device_handler, DeviceHandler)
|
|
|
|
time_now = self.clock.time_msec()
|
|
|
|
# TODO: Validate the JSON to make sure it has the right keys.
|
|
device_keys = keys.get("device_keys", None)
|
|
if device_keys:
|
|
logger.info(
|
|
"Updating device_keys for device %r for user %s at %d",
|
|
device_id,
|
|
user_id,
|
|
time_now,
|
|
)
|
|
log_kv(
|
|
{
|
|
"message": "Updating device_keys for user.",
|
|
"user_id": user_id,
|
|
"device_id": device_id,
|
|
}
|
|
)
|
|
# TODO: Sign the JSON with the server key
|
|
changed = await self.store.set_e2e_device_keys(
|
|
user_id, device_id, time_now, device_keys
|
|
)
|
|
if changed:
|
|
# Only notify about device updates *if* the keys actually changed
|
|
await self.device_handler.notify_device_update(user_id, [device_id])
|
|
else:
|
|
log_kv({"message": "Not updating device_keys for user", "user_id": user_id})
|
|
one_time_keys = keys.get("one_time_keys", None)
|
|
if one_time_keys:
|
|
log_kv(
|
|
{
|
|
"message": "Updating one_time_keys for device.",
|
|
"user_id": user_id,
|
|
"device_id": device_id,
|
|
}
|
|
)
|
|
await self._upload_one_time_keys_for_user(
|
|
user_id, device_id, time_now, one_time_keys
|
|
)
|
|
else:
|
|
log_kv(
|
|
{"message": "Did not update one_time_keys", "reason": "no keys given"}
|
|
)
|
|
fallback_keys = keys.get("fallback_keys") or keys.get(
|
|
"org.matrix.msc2732.fallback_keys"
|
|
)
|
|
if fallback_keys and isinstance(fallback_keys, dict):
|
|
log_kv(
|
|
{
|
|
"message": "Updating fallback_keys for device.",
|
|
"user_id": user_id,
|
|
"device_id": device_id,
|
|
}
|
|
)
|
|
await self.store.set_e2e_fallback_keys(user_id, device_id, fallback_keys)
|
|
elif fallback_keys:
|
|
log_kv({"message": "Did not update fallback_keys", "reason": "not a dict"})
|
|
else:
|
|
log_kv(
|
|
{"message": "Did not update fallback_keys", "reason": "no keys given"}
|
|
)
|
|
|
|
# the device should have been registered already, but it may have been
|
|
# deleted due to a race with a DELETE request. Or we may be using an
|
|
# old access_token without an associated device_id. Either way, we
|
|
# need to double-check the device is registered to avoid ending up with
|
|
# keys without a corresponding device.
|
|
await self.device_handler.check_device_registered(user_id, device_id)
|
|
|
|
result = await self.store.count_e2e_one_time_keys(user_id, device_id)
|
|
|
|
set_tag("one_time_key_counts", str(result))
|
|
return {"one_time_key_counts": result}
|
|
|
|
async def _upload_one_time_keys_for_user(
|
|
self, user_id: str, device_id: str, time_now: int, one_time_keys: JsonDict
|
|
) -> None:
|
|
logger.info(
|
|
"Adding one_time_keys %r for device %r for user %r at %d",
|
|
one_time_keys.keys(),
|
|
device_id,
|
|
user_id,
|
|
time_now,
|
|
)
|
|
|
|
# make a list of (alg, id, key) tuples
|
|
key_list = []
|
|
for key_id, key_obj in one_time_keys.items():
|
|
algorithm, key_id = key_id.split(":")
|
|
key_list.append((algorithm, key_id, key_obj))
|
|
|
|
# First we check if we have already persisted any of the keys.
|
|
existing_key_map = await self.store.get_e2e_one_time_keys(
|
|
user_id, device_id, [k_id for _, k_id, _ in key_list]
|
|
)
|
|
|
|
new_keys = [] # Keys that we need to insert. (alg, id, json) tuples.
|
|
for algorithm, key_id, key in key_list:
|
|
ex_json = existing_key_map.get((algorithm, key_id), None)
|
|
if ex_json:
|
|
if not _one_time_keys_match(ex_json, key):
|
|
raise SynapseError(
|
|
400,
|
|
(
|
|
"One time key %s:%s already exists. "
|
|
"Old key: %s; new key: %r"
|
|
)
|
|
% (algorithm, key_id, ex_json, key),
|
|
)
|
|
else:
|
|
new_keys.append(
|
|
(algorithm, key_id, encode_canonical_json(key).decode("ascii"))
|
|
)
|
|
|
|
log_kv({"message": "Inserting new one_time_keys.", "keys": new_keys})
|
|
await self.store.add_e2e_one_time_keys(user_id, device_id, time_now, new_keys)
|
|
|
|
async def upload_signing_keys_for_user(
|
|
self, user_id: str, keys: JsonDict
|
|
) -> JsonDict:
|
|
"""Upload signing keys for cross-signing
|
|
|
|
Args:
|
|
user_id: the user uploading the keys
|
|
keys: the signing keys
|
|
"""
|
|
# This can only be called from the main process.
|
|
assert isinstance(self.device_handler, DeviceHandler)
|
|
|
|
# if a master key is uploaded, then check it. Otherwise, load the
|
|
# stored master key, to check signatures on other keys
|
|
if "master_key" in keys:
|
|
master_key = keys["master_key"]
|
|
|
|
_check_cross_signing_key(master_key, user_id, "master")
|
|
else:
|
|
master_key = await self.store.get_e2e_cross_signing_key(user_id, "master")
|
|
|
|
# if there is no master key, then we can't do anything, because all the
|
|
# other cross-signing keys need to be signed by the master key
|
|
if not master_key:
|
|
raise SynapseError(400, "No master key available", Codes.MISSING_PARAM)
|
|
|
|
try:
|
|
master_key_id, master_verify_key = get_verify_key_from_cross_signing_key(
|
|
master_key
|
|
)
|
|
except ValueError:
|
|
if "master_key" in keys:
|
|
# the invalid key came from the request
|
|
raise SynapseError(400, "Invalid master key", Codes.INVALID_PARAM)
|
|
else:
|
|
# the invalid key came from the database
|
|
logger.error("Invalid master key found for user %s", user_id)
|
|
raise SynapseError(500, "Invalid master key")
|
|
|
|
# for the other cross-signing keys, make sure that they have valid
|
|
# signatures from the master key
|
|
if "self_signing_key" in keys:
|
|
self_signing_key = keys["self_signing_key"]
|
|
|
|
_check_cross_signing_key(
|
|
self_signing_key, user_id, "self_signing", master_verify_key
|
|
)
|
|
|
|
if "user_signing_key" in keys:
|
|
user_signing_key = keys["user_signing_key"]
|
|
|
|
_check_cross_signing_key(
|
|
user_signing_key, user_id, "user_signing", master_verify_key
|
|
)
|
|
|
|
# if everything checks out, then store the keys and send notifications
|
|
deviceids = []
|
|
if "master_key" in keys:
|
|
await self.store.set_e2e_cross_signing_key(user_id, "master", master_key)
|
|
deviceids.append(master_verify_key.version)
|
|
if "self_signing_key" in keys:
|
|
await self.store.set_e2e_cross_signing_key(
|
|
user_id, "self_signing", self_signing_key
|
|
)
|
|
try:
|
|
deviceids.append(
|
|
get_verify_key_from_cross_signing_key(self_signing_key)[1].version
|
|
)
|
|
except ValueError:
|
|
raise SynapseError(400, "Invalid self-signing key", Codes.INVALID_PARAM)
|
|
if "user_signing_key" in keys:
|
|
await self.store.set_e2e_cross_signing_key(
|
|
user_id, "user_signing", user_signing_key
|
|
)
|
|
# the signature stream matches the semantics that we want for
|
|
# user-signing key updates: only the user themselves is notified of
|
|
# their own user-signing key updates
|
|
await self.device_handler.notify_user_signature_update(user_id, [user_id])
|
|
|
|
# master key and self-signing key updates match the semantics of device
|
|
# list updates: all users who share an encrypted room are notified
|
|
if len(deviceids):
|
|
await self.device_handler.notify_device_update(user_id, deviceids)
|
|
|
|
return {}
|
|
|
|
async def upload_signatures_for_device_keys(
|
|
self, user_id: str, signatures: JsonDict
|
|
) -> JsonDict:
|
|
"""Upload device signatures for cross-signing
|
|
|
|
Args:
|
|
user_id: the user uploading the signatures
|
|
signatures: map of users to devices to signed keys. This is the submission
|
|
from the user; an exception will be raised if it is malformed.
|
|
Returns:
|
|
The response to be sent back to the client. The response will have
|
|
a "failures" key, which will be a dict mapping users to devices
|
|
to errors for the signatures that failed.
|
|
Raises:
|
|
SynapseError: if the signatures dict is not valid.
|
|
"""
|
|
# This can only be called from the main process.
|
|
assert isinstance(self.device_handler, DeviceHandler)
|
|
|
|
failures = {}
|
|
|
|
# signatures to be stored. Each item will be a SignatureListItem
|
|
signature_list = []
|
|
|
|
# split between checking signatures for own user and signatures for
|
|
# other users, since we verify them with different keys
|
|
self_signatures = signatures.get(user_id, {})
|
|
other_signatures = {k: v for k, v in signatures.items() if k != user_id}
|
|
|
|
self_signature_list, self_failures = await self._process_self_signatures(
|
|
user_id, self_signatures
|
|
)
|
|
signature_list.extend(self_signature_list)
|
|
failures.update(self_failures)
|
|
|
|
other_signature_list, other_failures = await self._process_other_signatures(
|
|
user_id, other_signatures
|
|
)
|
|
signature_list.extend(other_signature_list)
|
|
failures.update(other_failures)
|
|
|
|
# store the signature, and send the appropriate notifications for sync
|
|
logger.debug("upload signature failures: %r", failures)
|
|
await self.store.store_e2e_cross_signing_signatures(user_id, signature_list)
|
|
|
|
self_device_ids = [item.target_device_id for item in self_signature_list]
|
|
if self_device_ids:
|
|
await self.device_handler.notify_device_update(user_id, self_device_ids)
|
|
signed_users = [item.target_user_id for item in other_signature_list]
|
|
if signed_users:
|
|
await self.device_handler.notify_user_signature_update(
|
|
user_id, signed_users
|
|
)
|
|
|
|
return {"failures": failures}
|
|
|
|
async def _process_self_signatures(
|
|
self, user_id: str, signatures: JsonDict
|
|
) -> Tuple[List["SignatureListItem"], Dict[str, Dict[str, dict]]]:
|
|
"""Process uploaded signatures of the user's own keys.
|
|
|
|
Signatures of the user's own keys from this API come in two forms:
|
|
- signatures of the user's devices by the user's self-signing key,
|
|
- signatures of the user's master key by the user's devices.
|
|
|
|
Args:
|
|
user_id: the user uploading the keys
|
|
signatures (dict[string, dict]): map of devices to signed keys
|
|
|
|
Returns:
|
|
A tuple of a list of signatures to store, and a map of users to
|
|
devices to failure reasons
|
|
|
|
Raises:
|
|
SynapseError: if the input is malformed
|
|
"""
|
|
signature_list: List["SignatureListItem"] = []
|
|
failures: Dict[str, Dict[str, JsonDict]] = {}
|
|
if not signatures:
|
|
return signature_list, failures
|
|
|
|
if not isinstance(signatures, dict):
|
|
raise SynapseError(400, "Invalid parameter", Codes.INVALID_PARAM)
|
|
|
|
try:
|
|
# get our self-signing key to verify the signatures
|
|
(
|
|
_,
|
|
self_signing_key_id,
|
|
self_signing_verify_key,
|
|
) = await self._get_e2e_cross_signing_verify_key(user_id, "self_signing")
|
|
|
|
# get our master key, since we may have received a signature of it.
|
|
# We need to fetch it here so that we know what its key ID is, so
|
|
# that we can check if a signature that was sent is a signature of
|
|
# the master key or of a device
|
|
(
|
|
master_key,
|
|
_,
|
|
master_verify_key,
|
|
) = await self._get_e2e_cross_signing_verify_key(user_id, "master")
|
|
|
|
# fetch our stored devices. This is used to 1. verify
|
|
# signatures on the master key, and 2. to compare with what
|
|
# was sent if the device was signed
|
|
devices = await self.store.get_e2e_device_keys_for_cs_api([(user_id, None)])
|
|
|
|
if user_id not in devices:
|
|
raise NotFoundError("No device keys found")
|
|
|
|
devices = devices[user_id]
|
|
except SynapseError as e:
|
|
failure = _exception_to_failure(e)
|
|
failures[user_id] = {device: failure for device in signatures.keys()}
|
|
return signature_list, failures
|
|
|
|
for device_id, device in signatures.items():
|
|
# make sure submitted data is in the right form
|
|
if not isinstance(device, dict):
|
|
raise SynapseError(400, "Invalid parameter", Codes.INVALID_PARAM)
|
|
|
|
try:
|
|
if "signatures" not in device or user_id not in device["signatures"]:
|
|
# no signature was sent
|
|
raise SynapseError(
|
|
400, "Invalid signature", Codes.INVALID_SIGNATURE
|
|
)
|
|
|
|
if device_id == master_verify_key.version:
|
|
# The signature is of the master key. This needs to be
|
|
# handled differently from signatures of normal devices.
|
|
master_key_signature_list = self._check_master_key_signature(
|
|
user_id, device_id, device, master_key, devices
|
|
)
|
|
signature_list.extend(master_key_signature_list)
|
|
continue
|
|
|
|
# at this point, we have a device that should be signed
|
|
# by the self-signing key
|
|
if self_signing_key_id not in device["signatures"][user_id]:
|
|
# no signature was sent
|
|
raise SynapseError(
|
|
400, "Invalid signature", Codes.INVALID_SIGNATURE
|
|
)
|
|
|
|
try:
|
|
stored_device = devices[device_id]
|
|
except KeyError:
|
|
raise NotFoundError("Unknown device")
|
|
if self_signing_key_id in stored_device.get("signatures", {}).get(
|
|
user_id, {}
|
|
):
|
|
# we already have a signature on this device, so we
|
|
# can skip it, since it should be exactly the same
|
|
continue
|
|
|
|
_check_device_signature(
|
|
user_id, self_signing_verify_key, device, stored_device
|
|
)
|
|
|
|
signature = device["signatures"][user_id][self_signing_key_id]
|
|
signature_list.append(
|
|
SignatureListItem(
|
|
self_signing_key_id, user_id, device_id, signature
|
|
)
|
|
)
|
|
except SynapseError as e:
|
|
failures.setdefault(user_id, {})[device_id] = _exception_to_failure(e)
|
|
|
|
return signature_list, failures
|
|
|
|
def _check_master_key_signature(
|
|
self,
|
|
user_id: str,
|
|
master_key_id: str,
|
|
signed_master_key: JsonDict,
|
|
stored_master_key: JsonDict,
|
|
devices: Dict[str, Dict[str, JsonDict]],
|
|
) -> List["SignatureListItem"]:
|
|
"""Check signatures of a user's master key made by their devices.
|
|
|
|
Args:
|
|
user_id: the user whose master key is being checked
|
|
master_key_id: the ID of the user's master key
|
|
signed_master_key: the user's signed master key that was uploaded
|
|
stored_master_key: our previously-stored copy of the user's master key
|
|
devices: the user's devices
|
|
|
|
Returns:
|
|
A list of signatures to store
|
|
|
|
Raises:
|
|
SynapseError: if a signature is invalid
|
|
"""
|
|
# for each device that signed the master key, check the signature.
|
|
master_key_signature_list = []
|
|
sigs = signed_master_key["signatures"]
|
|
for signing_key_id, signature in sigs[user_id].items():
|
|
_, signing_device_id = signing_key_id.split(":", 1)
|
|
if (
|
|
signing_device_id not in devices
|
|
or signing_key_id not in devices[signing_device_id]["keys"]
|
|
):
|
|
# signed by an unknown device, or the
|
|
# device does not have the key
|
|
raise SynapseError(400, "Invalid signature", Codes.INVALID_SIGNATURE)
|
|
|
|
# get the key and check the signature
|
|
pubkey = devices[signing_device_id]["keys"][signing_key_id]
|
|
verify_key = decode_verify_key_bytes(signing_key_id, decode_base64(pubkey))
|
|
_check_device_signature(
|
|
user_id, verify_key, signed_master_key, stored_master_key
|
|
)
|
|
|
|
master_key_signature_list.append(
|
|
SignatureListItem(signing_key_id, user_id, master_key_id, signature)
|
|
)
|
|
|
|
return master_key_signature_list
|
|
|
|
async def _process_other_signatures(
|
|
self, user_id: str, signatures: Dict[str, dict]
|
|
) -> Tuple[List["SignatureListItem"], Dict[str, Dict[str, dict]]]:
|
|
"""Process uploaded signatures of other users' keys. These will be the
|
|
target user's master keys, signed by the uploading user's user-signing
|
|
key.
|
|
|
|
Args:
|
|
user_id: the user uploading the keys
|
|
signatures: map of users to devices to signed keys
|
|
|
|
Returns:
|
|
A list of signatures to store, and a map of users to devices to failure
|
|
reasons
|
|
|
|
Raises:
|
|
SynapseError: if the input is malformed
|
|
"""
|
|
signature_list: List["SignatureListItem"] = []
|
|
failures: Dict[str, Dict[str, JsonDict]] = {}
|
|
if not signatures:
|
|
return signature_list, failures
|
|
|
|
try:
|
|
# get our user-signing key to verify the signatures
|
|
(
|
|
user_signing_key,
|
|
user_signing_key_id,
|
|
user_signing_verify_key,
|
|
) = await self._get_e2e_cross_signing_verify_key(user_id, "user_signing")
|
|
except SynapseError as e:
|
|
failure = _exception_to_failure(e)
|
|
for user, devicemap in signatures.items():
|
|
failures[user] = {device_id: failure for device_id in devicemap.keys()}
|
|
return signature_list, failures
|
|
|
|
for target_user, devicemap in signatures.items():
|
|
# make sure submitted data is in the right form
|
|
if not isinstance(devicemap, dict):
|
|
raise SynapseError(400, "Invalid parameter", Codes.INVALID_PARAM)
|
|
for device in devicemap.values():
|
|
if not isinstance(device, dict):
|
|
raise SynapseError(400, "Invalid parameter", Codes.INVALID_PARAM)
|
|
|
|
device_id = None
|
|
try:
|
|
# get the target user's master key, to make sure it matches
|
|
# what was sent
|
|
(
|
|
master_key,
|
|
master_key_id,
|
|
_,
|
|
) = await self._get_e2e_cross_signing_verify_key(
|
|
target_user, "master", user_id
|
|
)
|
|
|
|
# make sure that the target user's master key is the one that
|
|
# was signed (and no others)
|
|
device_id = master_key_id.split(":", 1)[1]
|
|
if device_id not in devicemap:
|
|
logger.debug(
|
|
"upload signature: could not find signature for device %s",
|
|
device_id,
|
|
)
|
|
# set device to None so that the failure gets
|
|
# marked on all the signatures
|
|
device_id = None
|
|
raise NotFoundError("Unknown device")
|
|
key = devicemap[device_id]
|
|
other_devices = [k for k in devicemap.keys() if k != device_id]
|
|
if other_devices:
|
|
# other devices were signed -- mark those as failures
|
|
logger.debug("upload signature: too many devices specified")
|
|
failure = _exception_to_failure(NotFoundError("Unknown device"))
|
|
failures[target_user] = {
|
|
device: failure for device in other_devices
|
|
}
|
|
|
|
if user_signing_key_id in master_key.get("signatures", {}).get(
|
|
user_id, {}
|
|
):
|
|
# we already have the signature, so we can skip it
|
|
continue
|
|
|
|
_check_device_signature(
|
|
user_id, user_signing_verify_key, key, master_key
|
|
)
|
|
|
|
signature = key["signatures"][user_id][user_signing_key_id]
|
|
signature_list.append(
|
|
SignatureListItem(
|
|
user_signing_key_id, target_user, device_id, signature
|
|
)
|
|
)
|
|
except SynapseError as e:
|
|
failure = _exception_to_failure(e)
|
|
if device_id is None:
|
|
failures[target_user] = {
|
|
device_id: failure for device_id in devicemap.keys()
|
|
}
|
|
else:
|
|
failures.setdefault(target_user, {})[device_id] = failure
|
|
|
|
return signature_list, failures
|
|
|
|
async def _get_e2e_cross_signing_verify_key(
|
|
self, user_id: str, key_type: str, from_user_id: Optional[str] = None
|
|
) -> Tuple[JsonDict, str, VerifyKey]:
|
|
"""Fetch locally or remotely query for a cross-signing public key.
|
|
|
|
First, attempt to fetch the cross-signing public key from storage.
|
|
If that fails, query the keys from the homeserver they belong to
|
|
and update our local copy.
|
|
|
|
Args:
|
|
user_id: the user whose key should be fetched
|
|
key_type: the type of key to fetch
|
|
from_user_id: the user that we are fetching the keys for.
|
|
This affects what signatures are fetched.
|
|
|
|
Returns:
|
|
The raw key data, the key ID, and the signedjson verify key
|
|
|
|
Raises:
|
|
NotFoundError: if the key is not found
|
|
SynapseError: if `user_id` is invalid
|
|
"""
|
|
user = UserID.from_string(user_id)
|
|
key = await self.store.get_e2e_cross_signing_key(
|
|
user_id, key_type, from_user_id
|
|
)
|
|
|
|
if key:
|
|
# We found a copy of this key in our database. Decode and return it
|
|
key_id, verify_key = get_verify_key_from_cross_signing_key(key)
|
|
return key, key_id, verify_key
|
|
|
|
# If we couldn't find the key locally, and we're looking for keys of
|
|
# another user then attempt to fetch the missing key from the remote
|
|
# user's server.
|
|
#
|
|
# We may run into this in possible edge cases where a user tries to
|
|
# cross-sign a remote user, but does not share any rooms with them yet.
|
|
# Thus, we would not have their key list yet. We instead fetch the key,
|
|
# store it and notify clients of new, associated device IDs.
|
|
if self.is_mine(user) or key_type not in ["master", "self_signing"]:
|
|
# Note that master and self_signing keys are the only cross-signing keys we
|
|
# can request over federation
|
|
raise NotFoundError("No %s key found for %s" % (key_type, user_id))
|
|
|
|
cross_signing_keys = await self._retrieve_cross_signing_keys_for_remote_user(
|
|
user, key_type
|
|
)
|
|
if cross_signing_keys is None:
|
|
raise NotFoundError("No %s key found for %s" % (key_type, user_id))
|
|
|
|
return cross_signing_keys
|
|
|
|
async def _retrieve_cross_signing_keys_for_remote_user(
|
|
self,
|
|
user: UserID,
|
|
desired_key_type: str,
|
|
) -> Optional[Tuple[Dict[str, Any], str, VerifyKey]]:
|
|
"""Queries cross-signing keys for a remote user and saves them to the database
|
|
|
|
Only the key specified by `key_type` will be returned, while all retrieved keys
|
|
will be saved regardless
|
|
|
|
Args:
|
|
user: The user to query remote keys for
|
|
desired_key_type: The type of key to receive. One of "master", "self_signing"
|
|
|
|
Returns:
|
|
A tuple of the retrieved key content, the key's ID and the matching VerifyKey.
|
|
If the key cannot be retrieved, all values in the tuple will instead be None.
|
|
"""
|
|
# This can only be called from the main process.
|
|
assert isinstance(self.device_handler, DeviceHandler)
|
|
|
|
try:
|
|
remote_result = await self.federation.query_user_devices(
|
|
user.domain, user.to_string()
|
|
)
|
|
except Exception as e:
|
|
logger.warning(
|
|
"Unable to query %s for cross-signing keys of user %s: %s %s",
|
|
user.domain,
|
|
user.to_string(),
|
|
type(e),
|
|
e,
|
|
)
|
|
return None
|
|
|
|
# Process each of the retrieved cross-signing keys
|
|
desired_key_data = None
|
|
retrieved_device_ids = []
|
|
for key_type in ["master", "self_signing"]:
|
|
key_content = remote_result.get(key_type + "_key")
|
|
if not key_content:
|
|
continue
|
|
|
|
# Ensure these keys belong to the correct user
|
|
if "user_id" not in key_content:
|
|
logger.warning(
|
|
"Invalid %s key retrieved, missing user_id field: %s",
|
|
key_type,
|
|
key_content,
|
|
)
|
|
continue
|
|
if user.to_string() != key_content["user_id"]:
|
|
logger.warning(
|
|
"Found %s key of user %s when querying for keys of user %s",
|
|
key_type,
|
|
key_content["user_id"],
|
|
user.to_string(),
|
|
)
|
|
continue
|
|
|
|
# Validate the key contents
|
|
try:
|
|
# 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
|
|
key_id, verify_key = get_verify_key_from_cross_signing_key(key_content)
|
|
except ValueError as e:
|
|
logger.warning(
|
|
"Invalid %s key retrieved: %s - %s %s",
|
|
key_type,
|
|
key_content,
|
|
type(e),
|
|
e,
|
|
)
|
|
continue
|
|
|
|
# Note down the device ID attached to this key
|
|
retrieved_device_ids.append(verify_key.version)
|
|
|
|
# If this is the desired key type, save it and its ID/VerifyKey
|
|
if key_type == desired_key_type:
|
|
desired_key_data = key_content, key_id, verify_key
|
|
|
|
# At the same time, store this key in the db for subsequent queries
|
|
await self.store.set_e2e_cross_signing_key(
|
|
user.to_string(), key_type, key_content
|
|
)
|
|
|
|
# Notify clients that new devices for this user have been discovered
|
|
if retrieved_device_ids:
|
|
# XXX is this necessary?
|
|
await self.device_handler.notify_device_update(
|
|
user.to_string(), retrieved_device_ids
|
|
)
|
|
|
|
return desired_key_data
|
|
|
|
async def is_cross_signing_set_up_for_user(self, user_id: str) -> bool:
|
|
"""Checks if the user has cross-signing set up
|
|
|
|
Args:
|
|
user_id: The user to check
|
|
|
|
Returns:
|
|
True if the user has cross-signing set up, False otherwise
|
|
"""
|
|
existing_master_key = await self.store.get_e2e_cross_signing_key(
|
|
user_id, "master"
|
|
)
|
|
return existing_master_key is not None
|
|
|
|
|
|
def _check_cross_signing_key(
|
|
key: JsonDict, user_id: str, key_type: str, signing_key: Optional[VerifyKey] = None
|
|
) -> None:
|
|
"""Check a cross-signing key uploaded by a user. Performs some basic sanity
|
|
checking, and ensures that it is signed, if a signature is required.
|
|
|
|
Args:
|
|
key: the key data to verify
|
|
user_id: the user whose key is being checked
|
|
key_type: the type of key that the key should be
|
|
signing_key: the signing key that the key should be signed with. If
|
|
omitted, signatures will not be checked.
|
|
"""
|
|
if (
|
|
key.get("user_id") != user_id
|
|
or key_type not in key.get("usage", [])
|
|
or len(key.get("keys", {})) != 1
|
|
):
|
|
raise SynapseError(400, ("Invalid %s key" % (key_type,)), Codes.INVALID_PARAM)
|
|
|
|
if signing_key:
|
|
try:
|
|
verify_signed_json(key, user_id, signing_key)
|
|
except SignatureVerifyException:
|
|
raise SynapseError(
|
|
400, ("Invalid signature on %s key" % key_type), Codes.INVALID_SIGNATURE
|
|
)
|
|
|
|
|
|
def _check_device_signature(
|
|
user_id: str,
|
|
verify_key: VerifyKey,
|
|
signed_device: JsonDict,
|
|
stored_device: JsonDict,
|
|
) -> None:
|
|
"""Check that a signature on a device or cross-signing key is correct and
|
|
matches the copy of the device/key that we have stored. Throws an
|
|
exception if an error is detected.
|
|
|
|
Args:
|
|
user_id: the user ID whose signature is being checked
|
|
verify_key: the key to verify the device with
|
|
signed_device: the uploaded signed device data
|
|
stored_device: our previously stored copy of the device
|
|
|
|
Raises:
|
|
SynapseError: if the signature was invalid or the sent device is not the
|
|
same as the stored device
|
|
|
|
"""
|
|
|
|
# make sure that the device submitted matches what we have stored
|
|
stripped_signed_device = {
|
|
k: v for k, v in signed_device.items() if k not in ["signatures", "unsigned"]
|
|
}
|
|
stripped_stored_device = {
|
|
k: v for k, v in stored_device.items() if k not in ["signatures", "unsigned"]
|
|
}
|
|
if stripped_signed_device != stripped_stored_device:
|
|
logger.debug(
|
|
"upload signatures: key does not match %s vs %s",
|
|
signed_device,
|
|
stored_device,
|
|
)
|
|
raise SynapseError(400, "Key does not match")
|
|
|
|
try:
|
|
verify_signed_json(signed_device, user_id, verify_key)
|
|
except SignatureVerifyException:
|
|
logger.debug("invalid signature on key")
|
|
raise SynapseError(400, "Invalid signature", Codes.INVALID_SIGNATURE)
|
|
|
|
|
|
def _exception_to_failure(e: Exception) -> JsonDict:
|
|
if isinstance(e, SynapseError):
|
|
return {"status": e.code, "errcode": e.errcode, "message": str(e)}
|
|
|
|
if isinstance(e, CodeMessageException):
|
|
return {"status": e.code, "message": str(e)}
|
|
|
|
if isinstance(e, NotRetryingDestination):
|
|
return {"status": 503, "message": "Not ready for retry"}
|
|
|
|
# include ConnectionRefused and other errors
|
|
#
|
|
# Note that some Exceptions (notably twisted's ResponseFailed etc) don't
|
|
# give a string for e.message, which json then fails to serialize.
|
|
return {"status": 503, "message": str(e)}
|
|
|
|
|
|
def _one_time_keys_match(old_key_json: str, new_key: JsonDict) -> bool:
|
|
old_key = json_decoder.decode(old_key_json)
|
|
|
|
# if either is a string rather than an object, they must match exactly
|
|
if not isinstance(old_key, dict) or not isinstance(new_key, dict):
|
|
return old_key == new_key
|
|
|
|
# otherwise, we strip off the 'signatures' if any, because it's legitimate
|
|
# for different upload attempts to have different signatures.
|
|
old_key.pop("signatures", None)
|
|
new_key_copy = dict(new_key)
|
|
new_key_copy.pop("signatures", None)
|
|
|
|
return old_key == new_key_copy
|
|
|
|
|
|
@attr.s(slots=True, auto_attribs=True)
|
|
class SignatureListItem:
|
|
"""An item in the signature list as used by upload_signatures_for_device_keys."""
|
|
|
|
signing_key_id: str
|
|
target_user_id: str
|
|
target_device_id: str
|
|
signature: JsonDict
|
|
|
|
|
|
class SigningKeyEduUpdater:
|
|
"""Handles incoming signing key updates from federation and updates the DB"""
|
|
|
|
def __init__(self, hs: "HomeServer"):
|
|
self.store = hs.get_datastores().main
|
|
self.federation = hs.get_federation_client()
|
|
self.clock = hs.get_clock()
|
|
|
|
device_handler = hs.get_device_handler()
|
|
assert isinstance(device_handler, DeviceHandler)
|
|
self._device_handler = device_handler
|
|
|
|
self._remote_edu_linearizer = Linearizer(name="remote_signing_key")
|
|
|
|
# user_id -> list of updates waiting to be handled.
|
|
self._pending_updates: Dict[str, List[Tuple[JsonDict, JsonDict]]] = {}
|
|
|
|
async def incoming_signing_key_update(
|
|
self, origin: str, edu_content: JsonDict
|
|
) -> None:
|
|
"""Called on incoming signing key update from federation. Responsible for
|
|
parsing the EDU and adding to pending updates list.
|
|
|
|
Args:
|
|
origin: the server that sent the EDU
|
|
edu_content: the contents of the EDU
|
|
"""
|
|
|
|
user_id = edu_content.pop("user_id")
|
|
master_key = edu_content.pop("master_key", None)
|
|
self_signing_key = edu_content.pop("self_signing_key", None)
|
|
|
|
if get_domain_from_id(user_id) != origin:
|
|
logger.warning("Got signing key update edu for %r from %r", user_id, origin)
|
|
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.
|
|
return
|
|
|
|
self._pending_updates.setdefault(user_id, []).append(
|
|
(master_key, self_signing_key)
|
|
)
|
|
|
|
await self._handle_signing_key_updates(user_id)
|
|
|
|
async def _handle_signing_key_updates(self, user_id: str) -> None:
|
|
"""Actually handle pending updates.
|
|
|
|
Args:
|
|
user_id: the user whose updates we are processing
|
|
"""
|
|
|
|
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
|
|
|
|
device_ids: List[str] = []
|
|
|
|
logger.info("pending updates: %r", pending_updates)
|
|
|
|
for master_key, self_signing_key in pending_updates:
|
|
new_device_ids = await self._device_handler.device_list_updater.process_cross_signing_key_update(
|
|
user_id,
|
|
master_key,
|
|
self_signing_key,
|
|
)
|
|
device_ids = device_ids + new_device_ids
|
|
|
|
await self._device_handler.notify_device_update(user_id, device_ids)
|