1050 lines
41 KiB
Python
1050 lines
41 KiB
Python
# -*- coding: utf-8 -*-
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# Copyright 2016 OpenMarket Ltd
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# Copyright 2018-2019 New Vector Ltd
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# Copyright 2019 The Matrix.org Foundation C.I.C.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import logging
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from six import iteritems
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import attr
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from canonicaljson import encode_canonical_json, json
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from signedjson.key import decode_verify_key_bytes
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from signedjson.sign import SignatureVerifyException, verify_signed_json
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from unpaddedbase64 import decode_base64
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from twisted.internet import defer
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from synapse.api.errors import CodeMessageException, Codes, NotFoundError, SynapseError
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from synapse.logging.context import make_deferred_yieldable, run_in_background
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from synapse.logging.opentracing import log_kv, set_tag, tag_args, trace
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from synapse.types import (
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UserID,
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get_domain_from_id,
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get_verify_key_from_cross_signing_key,
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)
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from synapse.util import unwrapFirstError
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from synapse.util.retryutils import NotRetryingDestination
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logger = logging.getLogger(__name__)
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class E2eKeysHandler(object):
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def __init__(self, hs):
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self.store = hs.get_datastore()
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self.federation = hs.get_federation_client()
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self.device_handler = hs.get_device_handler()
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self.is_mine = hs.is_mine
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self.clock = hs.get_clock()
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# doesn't really work as part of the generic query API, because the
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# query request requires an object POST, but we abuse the
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# "query handler" interface.
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hs.get_federation_registry().register_query_handler(
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"client_keys", self.on_federation_query_client_keys
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)
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@trace
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@defer.inlineCallbacks
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def query_devices(self, query_body, timeout, from_user_id):
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""" Handle a device key query from a client
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{
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"device_keys": {
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"<user_id>": ["<device_id>"]
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}
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}
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->
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{
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"device_keys": {
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"<user_id>": {
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"<device_id>": {
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...
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}
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}
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}
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}
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Args:
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from_user_id (str): the user making the query. This is used when
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adding cross-signing signatures to limit what signatures users
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can see.
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"""
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device_keys_query = query_body.get("device_keys", {})
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# separate users by domain.
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# make a map from domain to user_id to device_ids
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local_query = {}
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remote_queries = {}
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for user_id, device_ids in device_keys_query.items():
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# we use UserID.from_string to catch invalid user ids
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if self.is_mine(UserID.from_string(user_id)):
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local_query[user_id] = device_ids
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else:
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remote_queries[user_id] = device_ids
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set_tag("local_key_query", local_query)
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set_tag("remote_key_query", remote_queries)
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# First get local devices.
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failures = {}
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results = {}
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if local_query:
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local_result = yield self.query_local_devices(local_query)
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for user_id, keys in local_result.items():
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if user_id in local_query:
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results[user_id] = keys
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# Now attempt to get any remote devices from our local cache.
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remote_queries_not_in_cache = {}
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if remote_queries:
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query_list = []
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for user_id, device_ids in iteritems(remote_queries):
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if device_ids:
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query_list.extend((user_id, device_id) for device_id in device_ids)
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else:
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query_list.append((user_id, None))
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user_ids_not_in_cache, remote_results = (
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yield self.store.get_user_devices_from_cache(query_list)
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)
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for user_id, devices in iteritems(remote_results):
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user_devices = results.setdefault(user_id, {})
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for device_id, device in iteritems(devices):
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keys = device.get("keys", None)
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device_display_name = device.get("device_display_name", None)
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if keys:
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result = dict(keys)
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unsigned = result.setdefault("unsigned", {})
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if device_display_name:
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unsigned["device_display_name"] = device_display_name
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user_devices[device_id] = result
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for user_id in user_ids_not_in_cache:
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domain = get_domain_from_id(user_id)
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r = remote_queries_not_in_cache.setdefault(domain, {})
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r[user_id] = remote_queries[user_id]
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# Get cached cross-signing keys
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cross_signing_keys = yield self.get_cross_signing_keys_from_cache(
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device_keys_query, from_user_id
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)
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# Now fetch any devices that we don't have in our cache
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@trace
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@defer.inlineCallbacks
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def do_remote_query(destination):
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"""This is called when we are querying the device list of a user on
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a remote homeserver and their device list is not in the device list
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cache. If we share a room with this user and we're not querying for
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specific user we will update the cache
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with their device list."""
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destination_query = remote_queries_not_in_cache[destination]
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# We first consider whether we wish to update the device list cache with
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# the users device list. We want to track a user's devices when the
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# authenticated user shares a room with the queried user and the query
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# has not specified a particular device.
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# If we update the cache for the queried user we remove them from further
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# queries. We use the more efficient batched query_client_keys for all
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# remaining users
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user_ids_updated = []
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for (user_id, device_list) in destination_query.items():
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if user_id in user_ids_updated:
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continue
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if device_list:
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continue
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room_ids = yield self.store.get_rooms_for_user(user_id)
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if not room_ids:
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continue
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# We've decided we're sharing a room with this user and should
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# probably be tracking their device lists. However, we haven't
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# done an initial sync on the device list so we do it now.
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try:
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user_devices = yield self.device_handler.device_list_updater.user_device_resync(
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user_id
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)
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user_devices = user_devices["devices"]
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for device in user_devices:
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results[user_id] = {device["device_id"]: device["keys"]}
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user_ids_updated.append(user_id)
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except Exception as e:
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failures[destination] = _exception_to_failure(e)
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if len(destination_query) == len(user_ids_updated):
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# We've updated all the users in the query and we do not need to
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# make any further remote calls.
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return
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# Remove all the users from the query which we have updated
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for user_id in user_ids_updated:
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destination_query.pop(user_id)
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try:
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remote_result = yield self.federation.query_client_keys(
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destination, {"device_keys": destination_query}, timeout=timeout
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)
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for user_id, keys in remote_result["device_keys"].items():
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if user_id in destination_query:
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results[user_id] = keys
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for user_id, key in remote_result["master_keys"].items():
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if user_id in destination_query:
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cross_signing_keys["master_keys"][user_id] = key
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for user_id, key in remote_result["self_signing_keys"].items():
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if user_id in destination_query:
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cross_signing_keys["self_signing_keys"][user_id] = key
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except Exception as e:
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failure = _exception_to_failure(e)
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failures[destination] = failure
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set_tag("error", True)
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set_tag("reason", failure)
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yield make_deferred_yieldable(
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defer.gatherResults(
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[
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run_in_background(do_remote_query, destination)
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for destination in remote_queries_not_in_cache
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],
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consumeErrors=True,
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).addErrback(unwrapFirstError)
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)
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ret = {"device_keys": results, "failures": failures}
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ret.update(cross_signing_keys)
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return ret
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@defer.inlineCallbacks
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def get_cross_signing_keys_from_cache(self, query, from_user_id):
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"""Get cross-signing keys for users from the database
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Args:
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query (Iterable[string]) an iterable of user IDs. A dict whose keys
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are user IDs satisfies this, so the query format used for
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query_devices can be used here.
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from_user_id (str): the user making the query. This is used when
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adding cross-signing signatures to limit what signatures users
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can see.
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Returns:
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defer.Deferred[dict[str, dict[str, dict]]]: map from
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(master|self_signing|user_signing) -> user_id -> key
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"""
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master_keys = {}
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self_signing_keys = {}
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user_signing_keys = {}
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for user_id in query:
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# XXX: consider changing the store functions to allow querying
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# multiple users simultaneously.
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key = yield self.store.get_e2e_cross_signing_key(
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user_id, "master", from_user_id
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)
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if key:
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master_keys[user_id] = key
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key = yield self.store.get_e2e_cross_signing_key(
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user_id, "self_signing", from_user_id
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)
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if key:
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self_signing_keys[user_id] = key
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# users can see other users' master and self-signing keys, but can
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# only see their own user-signing keys
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if from_user_id == user_id:
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key = yield self.store.get_e2e_cross_signing_key(
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user_id, "user_signing", from_user_id
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)
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if key:
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user_signing_keys[user_id] = key
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return {
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"master_keys": master_keys,
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"self_signing_keys": self_signing_keys,
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"user_signing_keys": user_signing_keys,
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}
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@trace
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@defer.inlineCallbacks
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def query_local_devices(self, query):
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"""Get E2E device keys for local users
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Args:
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query (dict[string, list[string]|None): map from user_id to a list
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of devices to query (None for all devices)
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Returns:
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defer.Deferred: (resolves to dict[string, dict[string, dict]]):
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map from user_id -> device_id -> device details
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"""
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set_tag("local_query", query)
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local_query = []
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result_dict = {}
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for user_id, device_ids in query.items():
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# we use UserID.from_string to catch invalid user ids
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if not self.is_mine(UserID.from_string(user_id)):
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logger.warning("Request for keys for non-local user %s", user_id)
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log_kv(
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{
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"message": "Requested a local key for a user which"
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" was not local to the homeserver",
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"user_id": user_id,
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}
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)
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set_tag("error", True)
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raise SynapseError(400, "Not a user here")
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if not device_ids:
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local_query.append((user_id, None))
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else:
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for device_id in device_ids:
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local_query.append((user_id, device_id))
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# make sure that each queried user appears in the result dict
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result_dict[user_id] = {}
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results = yield self.store.get_e2e_device_keys(local_query)
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# Build the result structure
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for user_id, device_keys in results.items():
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for device_id, device_info in device_keys.items():
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result_dict[user_id][device_id] = device_info
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log_kv(results)
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return result_dict
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@defer.inlineCallbacks
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def on_federation_query_client_keys(self, query_body):
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""" Handle a device key query from a federated server
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"""
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device_keys_query = query_body.get("device_keys", {})
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res = yield self.query_local_devices(device_keys_query)
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return {"device_keys": res}
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@trace
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@defer.inlineCallbacks
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def claim_one_time_keys(self, query, timeout):
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local_query = []
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remote_queries = {}
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for user_id, device_keys in query.get("one_time_keys", {}).items():
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# we use UserID.from_string to catch invalid user ids
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if self.is_mine(UserID.from_string(user_id)):
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for device_id, algorithm in device_keys.items():
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local_query.append((user_id, device_id, algorithm))
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else:
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domain = get_domain_from_id(user_id)
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remote_queries.setdefault(domain, {})[user_id] = device_keys
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set_tag("local_key_query", local_query)
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set_tag("remote_key_query", remote_queries)
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results = yield self.store.claim_e2e_one_time_keys(local_query)
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json_result = {}
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failures = {}
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for user_id, device_keys in results.items():
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for device_id, keys in device_keys.items():
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for key_id, json_bytes in keys.items():
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json_result.setdefault(user_id, {})[device_id] = {
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key_id: json.loads(json_bytes)
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}
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@trace
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@defer.inlineCallbacks
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def claim_client_keys(destination):
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set_tag("destination", destination)
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device_keys = remote_queries[destination]
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try:
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remote_result = yield self.federation.claim_client_keys(
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destination, {"one_time_keys": device_keys}, timeout=timeout
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)
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for user_id, keys in remote_result["one_time_keys"].items():
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if user_id in device_keys:
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json_result[user_id] = keys
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except Exception as e:
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failure = _exception_to_failure(e)
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failures[destination] = failure
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set_tag("error", True)
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set_tag("reason", failure)
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yield make_deferred_yieldable(
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defer.gatherResults(
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[
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run_in_background(claim_client_keys, destination)
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for destination in remote_queries
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],
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consumeErrors=True,
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)
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)
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logger.info(
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"Claimed one-time-keys: %s",
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",".join(
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(
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"%s for %s:%s" % (key_id, user_id, device_id)
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for user_id, user_keys in iteritems(json_result)
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for device_id, device_keys in iteritems(user_keys)
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for key_id, _ in iteritems(device_keys)
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)
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),
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)
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log_kv({"one_time_keys": json_result, "failures": failures})
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return {"one_time_keys": json_result, "failures": failures}
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@defer.inlineCallbacks
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@tag_args
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def upload_keys_for_user(self, user_id, device_id, keys):
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time_now = self.clock.time_msec()
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# TODO: Validate the JSON to make sure it has the right keys.
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device_keys = keys.get("device_keys", None)
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if device_keys:
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logger.info(
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"Updating device_keys for device %r for user %s at %d",
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device_id,
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user_id,
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time_now,
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)
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log_kv(
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{
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"message": "Updating device_keys for user.",
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"user_id": user_id,
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"device_id": device_id,
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}
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)
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# TODO: Sign the JSON with the server key
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changed = yield self.store.set_e2e_device_keys(
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user_id, device_id, time_now, device_keys
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)
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if changed:
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# Only notify about device updates *if* the keys actually changed
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yield self.device_handler.notify_device_update(user_id, [device_id])
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else:
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log_kv({"message": "Not updating device_keys for user", "user_id": user_id})
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one_time_keys = keys.get("one_time_keys", None)
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if one_time_keys:
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log_kv(
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{
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"message": "Updating one_time_keys for device.",
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"user_id": user_id,
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"device_id": device_id,
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}
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)
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yield self._upload_one_time_keys_for_user(
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user_id, device_id, time_now, one_time_keys
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)
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else:
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log_kv(
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{"message": "Did not update one_time_keys", "reason": "no keys given"}
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)
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# the device should have been registered already, but it may have been
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# deleted due to a race with a DELETE request. Or we may be using an
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# old access_token without an associated device_id. Either way, we
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# need to double-check the device is registered to avoid ending up with
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# keys without a corresponding device.
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yield self.device_handler.check_device_registered(user_id, device_id)
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result = yield self.store.count_e2e_one_time_keys(user_id, device_id)
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set_tag("one_time_key_counts", result)
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return {"one_time_key_counts": result}
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|
|
@defer.inlineCallbacks
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|
def _upload_one_time_keys_for_user(
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self, user_id, device_id, time_now, one_time_keys
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):
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logger.info(
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"Adding one_time_keys %r for device %r for user %r at %d",
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one_time_keys.keys(),
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device_id,
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user_id,
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time_now,
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)
|
|
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# make a list of (alg, id, key) tuples
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key_list = []
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for key_id, key_obj in one_time_keys.items():
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algorithm, key_id = key_id.split(":")
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key_list.append((algorithm, key_id, key_obj))
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# First we check if we have already persisted any of the keys.
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existing_key_map = yield self.store.get_e2e_one_time_keys(
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user_id, device_id, [k_id for _, k_id, _ in key_list]
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)
|
|
|
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new_keys = [] # Keys that we need to insert. (alg, id, json) tuples.
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|
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})
|
|
yield self.store.add_e2e_one_time_keys(user_id, device_id, time_now, new_keys)
|
|
|
|
@defer.inlineCallbacks
|
|
def upload_signing_keys_for_user(self, user_id, keys):
|
|
"""Upload signing keys for cross-signing
|
|
|
|
Args:
|
|
user_id (string): the user uploading the keys
|
|
keys (dict[string, dict]): the signing keys
|
|
"""
|
|
|
|
# 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 = yield 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:
|
|
yield self.store.set_e2e_cross_signing_key(user_id, "master", master_key)
|
|
deviceids.append(master_verify_key.version)
|
|
if "self_signing_key" in keys:
|
|
yield 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:
|
|
yield 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
|
|
yield 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):
|
|
yield self.device_handler.notify_device_update(user_id, deviceids)
|
|
|
|
return {}
|
|
|
|
@defer.inlineCallbacks
|
|
def upload_signatures_for_device_keys(self, user_id, signatures):
|
|
"""Upload device signatures for cross-signing
|
|
|
|
Args:
|
|
user_id (string): the user uploading the signatures
|
|
signatures (dict[string, dict[string, dict]]): 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:
|
|
dict: 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.
|
|
"""
|
|
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 = yield self._process_self_signatures(
|
|
user_id, self_signatures
|
|
)
|
|
signature_list.extend(self_signature_list)
|
|
failures.update(self_failures)
|
|
|
|
other_signature_list, other_failures = yield 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)
|
|
yield 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:
|
|
yield 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:
|
|
yield self.device_handler.notify_user_signature_update(
|
|
user_id, signed_users
|
|
)
|
|
|
|
return {"failures": failures}
|
|
|
|
@defer.inlineCallbacks
|
|
def _process_self_signatures(self, user_id, signatures):
|
|
"""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 (string): the user uploading the keys
|
|
signatures (dict[string, dict]): map of devices to signed keys
|
|
|
|
Returns:
|
|
(list[SignatureListItem], dict[string, dict[string, dict]]):
|
|
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 = []
|
|
failures = {}
|
|
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 = yield 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 = yield 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 = yield self.store.get_e2e_device_keys([(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, master_key_id, signed_master_key, stored_master_key, devices
|
|
):
|
|
"""Check signatures of a user's master key made by their devices.
|
|
|
|
Args:
|
|
user_id (string): the user whose master key is being checked
|
|
master_key_id (string): the ID of the user's master key
|
|
signed_master_key (dict): the user's signed master key that was uploaded
|
|
stored_master_key (dict): our previously-stored copy of the user's master key
|
|
devices (iterable(dict)): the user's devices
|
|
|
|
Returns:
|
|
list[SignatureListItem]: 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
|
|
|
|
@defer.inlineCallbacks
|
|
def _process_other_signatures(self, user_id, signatures):
|
|
"""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 (string): the user uploading the keys
|
|
signatures (dict[string, dict]): map of users to devices to signed keys
|
|
|
|
Returns:
|
|
(list[SignatureListItem], dict[string, dict[string, dict]]):
|
|
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 = []
|
|
failures = {}
|
|
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 = yield 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, _ = yield 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
|
|
|
|
@defer.inlineCallbacks
|
|
def _get_e2e_cross_signing_verify_key(self, user_id, key_type, from_user_id=None):
|
|
"""Fetch the cross-signing public key from storage and interpret it.
|
|
|
|
Args:
|
|
user_id (str): the user whose key should be fetched
|
|
key_type (str): the type of key to fetch
|
|
from_user_id (str): the user that we are fetching the keys for.
|
|
This affects what signatures are fetched.
|
|
|
|
Returns:
|
|
dict, str, VerifyKey: the raw key data, the key ID, and the
|
|
signedjson verify key
|
|
|
|
Raises:
|
|
NotFoundError: if the key is not found
|
|
"""
|
|
key = yield self.store.get_e2e_cross_signing_key(
|
|
user_id, key_type, from_user_id
|
|
)
|
|
if key is None:
|
|
logger.debug("no %s key found for %s", key_type, user_id)
|
|
raise NotFoundError("No %s key found for %s" % (key_type, user_id))
|
|
key_id, verify_key = get_verify_key_from_cross_signing_key(key)
|
|
return key, key_id, verify_key
|
|
|
|
|
|
def _check_cross_signing_key(key, user_id, key_type, signing_key=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 (dict): the key data to verify
|
|
user_id (str): the user whose key is being checked
|
|
key_type (str): the type of key that the key should be
|
|
signing_key (VerifyKey): (optional) 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, verify_key, signed_device, stored_device):
|
|
"""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 (str): the user ID whose signature is being checked
|
|
verify_key (VerifyKey): the key to verify the device with
|
|
signed_device (dict): the uploaded signed device data
|
|
stored_device (dict): 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):
|
|
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, new_key):
|
|
old_key = json.loads(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
|
|
class SignatureListItem:
|
|
"""An item in the signature list as used by upload_signatures_for_device_keys.
|
|
"""
|
|
|
|
signing_key_id = attr.ib()
|
|
target_user_id = attr.ib()
|
|
target_device_id = attr.ib()
|
|
signature = attr.ib()
|