429 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			429 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			Python
		
	
	
# -*- coding: utf-8 -*-
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# Copyright 2016 OpenMarket Ltd
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# Copyright 2018 New Vector Ltd
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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#     http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import logging
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from six import iteritems
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from canonicaljson import encode_canonical_json, json
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from twisted.internet import defer
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from synapse.api.errors import CodeMessageException, SynapseError
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from synapse.logging.context import make_deferred_yieldable, run_in_background
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from synapse.types import UserID, get_domain_from_id
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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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    @defer.inlineCallbacks
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    def query_devices(self, query_body, timeout):
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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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        """
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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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        # 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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        # Now fetch any devices that we don't have in our cache
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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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            except Exception as e:
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                failure = _exception_to_failure(e)
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                failures[destination] = 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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        return {"device_keys": results, "failures": failures}
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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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        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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                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, un-jsonify the results, and add the
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        # "unsigned" section
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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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                r = dict(device_info["keys"])
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                r["unsigned"] = {}
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                display_name = device_info["device_display_name"]
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                if display_name is not None:
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                    r["unsigned"]["device_display_name"] = display_name
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                result_dict[user_id][device_id] = r
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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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    @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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        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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        @defer.inlineCallbacks
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        def claim_client_keys(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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        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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        return {"one_time_keys": json_result, "failures": failures}
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    @defer.inlineCallbacks
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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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            # 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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        one_time_keys = keys.get("one_time_keys", None)
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        if one_time_keys:
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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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        # 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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        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:
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            ex_json = existing_key_map.get((algorithm, key_id), None)
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            if ex_json:
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                if not _one_time_keys_match(ex_json, key):
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                    raise SynapseError(
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                        400,
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                        (
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                            "One time key %s:%s already exists. "
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                            "Old key: %s; new key: %r"
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                        )
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                        % (algorithm, key_id, ex_json, key),
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                    )
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            else:
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                new_keys.append(
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                    (algorithm, key_id, encode_canonical_json(key).decode("ascii"))
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                )
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        yield self.store.add_e2e_one_time_keys(user_id, device_id, time_now, new_keys)
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def _exception_to_failure(e):
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    if isinstance(e, CodeMessageException):
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        return {"status": e.code, "message": str(e)}
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    if isinstance(e, NotRetryingDestination):
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        return {"status": 503, "message": "Not ready for retry"}
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    # include ConnectionRefused and other errors
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    #
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    # Note that some Exceptions (notably twisted's ResponseFailed etc) don't
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    # give a string for e.message, which json then fails to serialize.
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    return {"status": 503, "message": str(e)}
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def _one_time_keys_match(old_key_json, new_key):
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    old_key = json.loads(old_key_json)
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    # if either is a string rather than an object, they must match exactly
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    if not isinstance(old_key, dict) or not isinstance(new_key, dict):
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        return old_key == new_key
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    # otherwise, we strip off the 'signatures' if any, because it's legitimate
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    # for different upload attempts to have different signatures.
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    old_key.pop("signatures", None)
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    new_key_copy = dict(new_key)
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    new_key_copy.pop("signatures", None)
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 | 
						|
    return old_key == new_key_copy
 |