1406 lines
		
	
	
		
			55 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			1406 lines
		
	
	
		
			55 KiB
		
	
	
	
		
			Python
		
	
	
| # Copyright 2016 OpenMarket Ltd
 | |
| # Copyright 2018-2019 New Vector Ltd
 | |
| # Copyright 2019 The Matrix.org Foundation C.I.C.
 | |
| #
 | |
| # Licensed under the Apache License, Version 2.0 (the "License");
 | |
| # you may not use this file except in compliance with the License.
 | |
| # You may obtain a copy of the License at
 | |
| #
 | |
| #     http://www.apache.org/licenses/LICENSE-2.0
 | |
| #
 | |
| # Unless required by applicable law or agreed to in writing, software
 | |
| # distributed under the License is distributed on an "AS IS" BASIS,
 | |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 | |
| # See the License for the specific language governing permissions and
 | |
| # limitations under the License.
 | |
| 
 | |
| import logging
 | |
| from typing import TYPE_CHECKING, Any, Dict, Iterable, List, Mapping, Optional, Tuple
 | |
| 
 | |
| import attr
 | |
| from canonicaljson import encode_canonical_json
 | |
| from signedjson.key import VerifyKey, decode_verify_key_bytes
 | |
| from signedjson.sign import SignatureVerifyException, verify_signed_json
 | |
| from unpaddedbase64 import decode_base64
 | |
| 
 | |
| from twisted.internet import defer
 | |
| 
 | |
| from synapse.api.constants import EduTypes
 | |
| from synapse.api.errors import CodeMessageException, Codes, NotFoundError, SynapseError
 | |
| from synapse.logging.context import make_deferred_yieldable, run_in_background
 | |
| from synapse.logging.opentracing import log_kv, set_tag, tag_args, trace
 | |
| from synapse.replication.http.devices import ReplicationUserDevicesResyncRestServlet
 | |
| from synapse.types import (
 | |
|     JsonDict,
 | |
|     UserID,
 | |
|     get_domain_from_id,
 | |
|     get_verify_key_from_cross_signing_key,
 | |
| )
 | |
| from synapse.util import json_decoder, unwrapFirstError
 | |
| from synapse.util.async_helpers import Linearizer
 | |
| from synapse.util.retryutils import NotRetryingDestination
 | |
| 
 | |
| if TYPE_CHECKING:
 | |
|     from synapse.server import HomeServer
 | |
| 
 | |
| logger = logging.getLogger(__name__)
 | |
| 
 | |
| 
 | |
| class E2eKeysHandler:
 | |
|     def __init__(self, hs: "HomeServer"):
 | |
|         self.store = hs.get_datastores().main
 | |
|         self.federation = hs.get_federation_client()
 | |
|         self.device_handler = hs.get_device_handler()
 | |
|         self.is_mine = hs.is_mine
 | |
|         self.clock = hs.get_clock()
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| 
 | |
|         self._edu_updater = SigningKeyEduUpdater(hs, self)
 | |
| 
 | |
|         federation_registry = hs.get_federation_registry()
 | |
| 
 | |
|         self._is_master = hs.config.worker.worker_app is None
 | |
|         if not self._is_master:
 | |
|             self._user_device_resync_client = (
 | |
|                 ReplicationUserDevicesResyncRestServlet.make_client(hs)
 | |
|             )
 | |
|         else:
 | |
|             # Only register this edu handler on master as it requires writing
 | |
|             # device updates to the db
 | |
|             federation_registry.register_edu_handler(
 | |
|                 EduTypes.SIGNING_KEY_UPDATE,
 | |
|                 self._edu_updater.incoming_signing_key_update,
 | |
|             )
 | |
|             # also handle the unstable version
 | |
|             # FIXME: remove this when enough servers have upgraded
 | |
|             federation_registry.register_edu_handler(
 | |
|                 EduTypes.UNSTABLE_SIGNING_KEY_UPDATE,
 | |
|                 self._edu_updater.incoming_signing_key_update,
 | |
|             )
 | |
| 
 | |
|         # doesn't really work as part of the generic query API, because the
 | |
|         # query request requires an object POST, but we abuse the
 | |
|         # "query handler" interface.
 | |
|         federation_registry.register_query_handler(
 | |
|             "client_keys", self.on_federation_query_client_keys
 | |
|         )
 | |
| 
 | |
|         # Limit the number of in-flight requests from a single device.
 | |
|         self._query_devices_linearizer = Linearizer(
 | |
|             name="query_devices",
 | |
|             max_count=10,
 | |
|         )
 | |
| 
 | |
|     @trace
 | |
|     async def query_devices(
 | |
|         self,
 | |
|         query_body: JsonDict,
 | |
|         timeout: int,
 | |
|         from_user_id: str,
 | |
|         from_device_id: Optional[str],
 | |
|     ) -> JsonDict:
 | |
|         """Handle a device key query from a client
 | |
| 
 | |
|         {
 | |
|             "device_keys": {
 | |
|                 "<user_id>": ["<device_id>"]
 | |
|             }
 | |
|         }
 | |
|         ->
 | |
|         {
 | |
|             "device_keys": {
 | |
|                 "<user_id>": {
 | |
|                     "<device_id>": {
 | |
|                         ...
 | |
|                     }
 | |
|                 }
 | |
|             }
 | |
|         }
 | |
| 
 | |
|         Args:
 | |
|             from_user_id: the user making the query.  This is used when
 | |
|                 adding cross-signing signatures to limit what signatures users
 | |
|                 can see.
 | |
|             from_device_id: the device making the query. This is used to limit
 | |
|                 the number of in-flight queries at a time.
 | |
|         """
 | |
|         async with self._query_devices_linearizer.queue((from_user_id, from_device_id)):
 | |
|             device_keys_query: Dict[str, List[str]] = query_body.get("device_keys", {})
 | |
| 
 | |
|             # separate users by domain.
 | |
|             # make a map from domain to user_id to device_ids
 | |
|             local_query = {}
 | |
|             remote_queries = {}
 | |
| 
 | |
|             for user_id, device_ids in device_keys_query.items():
 | |
|                 # we use UserID.from_string to catch invalid user ids
 | |
|                 if self.is_mine(UserID.from_string(user_id)):
 | |
|                     local_query[user_id] = device_ids
 | |
|                 else:
 | |
|                     remote_queries[user_id] = device_ids
 | |
| 
 | |
|             set_tag("local_key_query", str(local_query))
 | |
|             set_tag("remote_key_query", str(remote_queries))
 | |
| 
 | |
|             # First get local devices.
 | |
|             # A map of destination -> failure response.
 | |
|             failures: Dict[str, JsonDict] = {}
 | |
|             results = {}
 | |
|             if local_query:
 | |
|                 local_result = await self.query_local_devices(local_query)
 | |
|                 for user_id, keys in local_result.items():
 | |
|                     if user_id in local_query:
 | |
|                         results[user_id] = keys
 | |
| 
 | |
|             # Get cached cross-signing keys
 | |
|             cross_signing_keys = await self.get_cross_signing_keys_from_cache(
 | |
|                 device_keys_query, from_user_id
 | |
|             )
 | |
| 
 | |
|             # Now attempt to get any remote devices from our local cache.
 | |
|             # A map of destination -> user ID -> device IDs.
 | |
|             remote_queries_not_in_cache: Dict[str, Dict[str, Iterable[str]]] = {}
 | |
|             if remote_queries:
 | |
|                 query_list: List[Tuple[str, Optional[str]]] = []
 | |
|                 for user_id, device_ids in remote_queries.items():
 | |
|                     if device_ids:
 | |
|                         query_list.extend(
 | |
|                             (user_id, device_id) for device_id in device_ids
 | |
|                         )
 | |
|                     else:
 | |
|                         query_list.append((user_id, None))
 | |
| 
 | |
|                 (
 | |
|                     user_ids_not_in_cache,
 | |
|                     remote_results,
 | |
|                 ) = await self.store.get_user_devices_from_cache(query_list)
 | |
|                 for user_id, devices in remote_results.items():
 | |
|                     user_devices = results.setdefault(user_id, {})
 | |
|                     for device_id, device in devices.items():
 | |
|                         keys = device.get("keys", None)
 | |
|                         device_display_name = device.get("device_display_name", None)
 | |
|                         if keys:
 | |
|                             result = dict(keys)
 | |
|                             unsigned = result.setdefault("unsigned", {})
 | |
|                             if device_display_name:
 | |
|                                 unsigned["device_display_name"] = device_display_name
 | |
|                             user_devices[device_id] = result
 | |
| 
 | |
|                 # check for missing cross-signing keys.
 | |
|                 for user_id in remote_queries.keys():
 | |
|                     cached_cross_master = user_id in cross_signing_keys["master_keys"]
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|                     cached_cross_selfsigning = (
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|                         user_id in cross_signing_keys["self_signing_keys"]
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|                     )
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| 
 | |
|                     # check if we are missing only one of cross-signing master or
 | |
|                     # self-signing key, but the other one is cached.
 | |
|                     # as we need both, this will issue a federation request.
 | |
|                     # if we don't have any of the keys, either the user doesn't have
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|                     # cross-signing set up, or the cached device list
 | |
|                     # is not (yet) updated.
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|                     if cached_cross_master ^ cached_cross_selfsigning:
 | |
|                         user_ids_not_in_cache.add(user_id)
 | |
| 
 | |
|                 # add those users to the list to fetch over federation.
 | |
|                 for user_id in user_ids_not_in_cache:
 | |
|                     domain = get_domain_from_id(user_id)
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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
 | |
|             await make_deferred_yieldable(
 | |
|                 defer.gatherResults(
 | |
|                     [
 | |
|                         run_in_background(
 | |
|                             self._query_devices_for_destination,
 | |
|                             results,
 | |
|                             cross_signing_keys,
 | |
|                             failures,
 | |
|                             destination,
 | |
|                             queries,
 | |
|                             timeout,
 | |
|                         )
 | |
|                         for destination, queries in remote_queries_not_in_cache.items()
 | |
|                     ],
 | |
|                     consumeErrors=True,
 | |
|                 ).addErrback(unwrapFirstError)
 | |
|             )
 | |
| 
 | |
|             ret = {"device_keys": results, "failures": failures}
 | |
| 
 | |
|             ret.update(cross_signing_keys)
 | |
| 
 | |
|             return ret
 | |
| 
 | |
|     @trace
 | |
|     async def _query_devices_for_destination(
 | |
|         self,
 | |
|         results: JsonDict,
 | |
|         cross_signing_keys: JsonDict,
 | |
|         failures: Dict[str, JsonDict],
 | |
|         destination: str,
 | |
|         destination_query: Dict[str, Iterable[str]],
 | |
|         timeout: int,
 | |
|     ) -> None:
 | |
|         """This is called when we are querying the device list of a user on
 | |
|         a remote homeserver and their device list is not in the device list
 | |
|         cache. If we share a room with this user and we're not querying for
 | |
|         specific user we will update the cache with their device list.
 | |
| 
 | |
|         Args:
 | |
|             results: A map from user ID to their device keys, which gets
 | |
|                 updated with the newly fetched keys.
 | |
|             cross_signing_keys: Map from user ID to their cross signing keys,
 | |
|                 which gets updated with the newly fetched keys.
 | |
|             failures: Map of destinations to failures that have occurred while
 | |
|                 attempting to fetch keys.
 | |
|             destination: The remote server to query
 | |
|             destination_query: The query dict of devices to query the remote
 | |
|                 server for.
 | |
|             timeout: The timeout for remote HTTP requests.
 | |
|         """
 | |
| 
 | |
|         # We first consider whether we wish to update the device list cache with
 | |
|         # the users device list. We want to track a user's devices when the
 | |
|         # authenticated user shares a room with the queried user and the query
 | |
|         # has not specified a particular device.
 | |
|         # If we update the cache for the queried user we remove them from further
 | |
|         # queries. We use the more efficient batched query_client_keys for all
 | |
|         # remaining users
 | |
|         user_ids_updated = []
 | |
|         for (user_id, device_list) in destination_query.items():
 | |
|             if user_id in user_ids_updated:
 | |
|                 continue
 | |
| 
 | |
|             if device_list:
 | |
|                 continue
 | |
| 
 | |
|             room_ids = await self.store.get_rooms_for_user(user_id)
 | |
|             if not room_ids:
 | |
|                 continue
 | |
| 
 | |
|             # We've decided we're sharing a room with this user and should
 | |
|             # probably be tracking their device lists. However, we haven't
 | |
|             # done an initial sync on the device list so we do it now.
 | |
|             try:
 | |
|                 if self._is_master:
 | |
|                     resync_results = await self.device_handler.device_list_updater.user_device_resync(
 | |
|                         user_id
 | |
|                     )
 | |
|                 else:
 | |
|                     resync_results = await self._user_device_resync_client(
 | |
|                         user_id=user_id
 | |
|                     )
 | |
| 
 | |
|                 # Add the device keys to the results.
 | |
|                 user_devices = resync_results["devices"]
 | |
|                 user_results = results.setdefault(user_id, {})
 | |
|                 for device in user_devices:
 | |
|                     user_results[device["device_id"]] = device["keys"]
 | |
|                 user_ids_updated.append(user_id)
 | |
| 
 | |
|                 # Add any cross signing keys to the results.
 | |
|                 master_key = resync_results.get("master_key")
 | |
|                 self_signing_key = resync_results.get("self_signing_key")
 | |
| 
 | |
|                 if master_key:
 | |
|                     cross_signing_keys["master_keys"][user_id] = master_key
 | |
| 
 | |
|                 if self_signing_key:
 | |
|                     cross_signing_keys["self_signing_keys"][user_id] = self_signing_key
 | |
|             except Exception as e:
 | |
|                 failures[destination] = _exception_to_failure(e)
 | |
| 
 | |
|         if len(destination_query) == len(user_ids_updated):
 | |
|             # We've updated all the users in the query and we do not need to
 | |
|             # make any further remote calls.
 | |
|             return
 | |
| 
 | |
|         # Remove all the users from the query which we have updated
 | |
|         for user_id in user_ids_updated:
 | |
|             destination_query.pop(user_id)
 | |
| 
 | |
|         try:
 | |
|             remote_result = await self.federation.query_client_keys(
 | |
|                 destination, {"device_keys": destination_query}, timeout=timeout
 | |
|             )
 | |
| 
 | |
|             for user_id, keys in remote_result["device_keys"].items():
 | |
|                 if user_id in destination_query:
 | |
|                     results[user_id] = keys
 | |
| 
 | |
|             if "master_keys" in remote_result:
 | |
|                 for user_id, key in remote_result["master_keys"].items():
 | |
|                     if user_id in destination_query:
 | |
|                         cross_signing_keys["master_keys"][user_id] = key
 | |
| 
 | |
|             if "self_signing_keys" in remote_result:
 | |
|                 for user_id, key in remote_result["self_signing_keys"].items():
 | |
|                     if user_id in destination_query:
 | |
|                         cross_signing_keys["self_signing_keys"][user_id] = key
 | |
| 
 | |
|         except Exception as e:
 | |
|             failure = _exception_to_failure(e)
 | |
|             failures[destination] = failure
 | |
|             set_tag("error", True)
 | |
|             set_tag("reason", str(failure))
 | |
| 
 | |
|         return
 | |
| 
 | |
|     async def get_cross_signing_keys_from_cache(
 | |
|         self, query: Iterable[str], from_user_id: Optional[str]
 | |
|     ) -> Dict[str, Dict[str, dict]]:
 | |
|         """Get cross-signing keys for users from the database
 | |
| 
 | |
|         Args:
 | |
|             query: an iterable of user IDs.  A dict whose keys
 | |
|                 are user IDs satisfies this, so the query format used for
 | |
|                 query_devices can be used here.
 | |
|             from_user_id: the user making the query.  This is used when
 | |
|                 adding cross-signing signatures to limit what signatures users
 | |
|                 can see.
 | |
| 
 | |
|         Returns:
 | |
|             A map from (master_keys|self_signing_keys|user_signing_keys) -> user_id -> key
 | |
|         """
 | |
|         master_keys = {}
 | |
|         self_signing_keys = {}
 | |
|         user_signing_keys = {}
 | |
| 
 | |
|         user_ids = list(query)
 | |
| 
 | |
|         keys = await self.store.get_e2e_cross_signing_keys_bulk(user_ids, from_user_id)
 | |
| 
 | |
|         for user_id, user_info in keys.items():
 | |
|             if user_info is None:
 | |
|                 continue
 | |
|             if "master" in user_info:
 | |
|                 master_keys[user_id] = user_info["master"]
 | |
|             if "self_signing" in user_info:
 | |
|                 self_signing_keys[user_id] = user_info["self_signing"]
 | |
| 
 | |
|         # users can see other users' master and self-signing keys, but can
 | |
|         # only see their own user-signing keys
 | |
|         if from_user_id:
 | |
|             from_user_key = keys.get(from_user_id)
 | |
|             if from_user_key and "user_signing" in from_user_key:
 | |
|                 user_signing_keys[from_user_id] = from_user_key["user_signing"]
 | |
| 
 | |
|         return {
 | |
|             "master_keys": master_keys,
 | |
|             "self_signing_keys": self_signing_keys,
 | |
|             "user_signing_keys": user_signing_keys,
 | |
|         }
 | |
| 
 | |
|     @trace
 | |
|     async def query_local_devices(
 | |
|         self, query: Mapping[str, Optional[List[str]]]
 | |
|     ) -> Dict[str, Dict[str, dict]]:
 | |
|         """Get E2E device keys for local users
 | |
| 
 | |
|         Args:
 | |
|             query: map from user_id to a list
 | |
|                  of devices to query (None for all devices)
 | |
| 
 | |
|         Returns:
 | |
|             A map from user_id -> device_id -> device details
 | |
|         """
 | |
|         set_tag("local_query", str(query))
 | |
|         local_query: List[Tuple[str, Optional[str]]] = []
 | |
| 
 | |
|         result_dict: Dict[str, Dict[str, dict]] = {}
 | |
|         for user_id, device_ids in query.items():
 | |
|             # we use UserID.from_string to catch invalid user ids
 | |
|             if not self.is_mine(UserID.from_string(user_id)):
 | |
|                 logger.warning("Request for keys for non-local user %s", user_id)
 | |
|                 log_kv(
 | |
|                     {
 | |
|                         "message": "Requested a local key for a user which"
 | |
|                         " was not local to the homeserver",
 | |
|                         "user_id": user_id,
 | |
|                     }
 | |
|                 )
 | |
|                 set_tag("error", True)
 | |
|                 raise SynapseError(400, "Not a user here")
 | |
| 
 | |
|             if not device_ids:
 | |
|                 local_query.append((user_id, None))
 | |
|             else:
 | |
|                 for device_id in device_ids:
 | |
|                     local_query.append((user_id, device_id))
 | |
| 
 | |
|             # make sure that each queried user appears in the result dict
 | |
|             result_dict[user_id] = {}
 | |
| 
 | |
|         results = await self.store.get_e2e_device_keys_for_cs_api(local_query)
 | |
| 
 | |
|         # Build the result structure
 | |
|         for user_id, device_keys in results.items():
 | |
|             for device_id, device_info in device_keys.items():
 | |
|                 result_dict[user_id][device_id] = device_info
 | |
| 
 | |
|         log_kv(results)
 | |
|         return result_dict
 | |
| 
 | |
|     async def on_federation_query_client_keys(
 | |
|         self, query_body: Dict[str, Dict[str, Optional[List[str]]]]
 | |
|     ) -> JsonDict:
 | |
|         """Handle a device key query from a federated server"""
 | |
|         device_keys_query: Dict[str, Optional[List[str]]] = query_body.get(
 | |
|             "device_keys", {}
 | |
|         )
 | |
|         res = await self.query_local_devices(device_keys_query)
 | |
|         ret = {"device_keys": res}
 | |
| 
 | |
|         # add in the cross-signing keys
 | |
|         cross_signing_keys = await self.get_cross_signing_keys_from_cache(
 | |
|             device_keys_query, None
 | |
|         )
 | |
| 
 | |
|         ret.update(cross_signing_keys)
 | |
| 
 | |
|         return ret
 | |
| 
 | |
|     @trace
 | |
|     async def claim_one_time_keys(
 | |
|         self, query: Dict[str, Dict[str, Dict[str, str]]], timeout: Optional[int]
 | |
|     ) -> JsonDict:
 | |
|         local_query: List[Tuple[str, str, str]] = []
 | |
|         remote_queries: Dict[str, Dict[str, Dict[str, str]]] = {}
 | |
| 
 | |
|         for user_id, one_time_keys in query.get("one_time_keys", {}).items():
 | |
|             # we use UserID.from_string to catch invalid user ids
 | |
|             if self.is_mine(UserID.from_string(user_id)):
 | |
|                 for device_id, algorithm in one_time_keys.items():
 | |
|                     local_query.append((user_id, device_id, algorithm))
 | |
|             else:
 | |
|                 domain = get_domain_from_id(user_id)
 | |
|                 remote_queries.setdefault(domain, {})[user_id] = one_time_keys
 | |
| 
 | |
|         set_tag("local_key_query", str(local_query))
 | |
|         set_tag("remote_key_query", str(remote_queries))
 | |
| 
 | |
|         results = await self.store.claim_e2e_one_time_keys(local_query)
 | |
| 
 | |
|         # A map of user ID -> device ID -> key ID -> key.
 | |
|         json_result: Dict[str, Dict[str, Dict[str, JsonDict]]] = {}
 | |
|         failures: Dict[str, JsonDict] = {}
 | |
|         for user_id, device_keys in results.items():
 | |
|             for device_id, keys in device_keys.items():
 | |
|                 for key_id, json_str in keys.items():
 | |
|                     json_result.setdefault(user_id, {})[device_id] = {
 | |
|                         key_id: json_decoder.decode(json_str)
 | |
|                     }
 | |
| 
 | |
|         @trace
 | |
|         async def claim_client_keys(destination: str) -> None:
 | |
|             set_tag("destination", destination)
 | |
|             device_keys = remote_queries[destination]
 | |
|             try:
 | |
|                 remote_result = await self.federation.claim_client_keys(
 | |
|                     destination, {"one_time_keys": device_keys}, timeout=timeout
 | |
|                 )
 | |
|                 for user_id, keys in remote_result["one_time_keys"].items():
 | |
|                     if user_id in device_keys:
 | |
|                         json_result[user_id] = keys
 | |
| 
 | |
|             except Exception as e:
 | |
|                 failure = _exception_to_failure(e)
 | |
|                 failures[destination] = failure
 | |
|                 set_tag("error", True)
 | |
|                 set_tag("reason", str(failure))
 | |
| 
 | |
|         await make_deferred_yieldable(
 | |
|             defer.gatherResults(
 | |
|                 [
 | |
|                     run_in_background(claim_client_keys, destination)
 | |
|                     for destination in remote_queries
 | |
|                 ],
 | |
|                 consumeErrors=True,
 | |
|             )
 | |
|         )
 | |
| 
 | |
|         logger.info(
 | |
|             "Claimed one-time-keys: %s",
 | |
|             ",".join(
 | |
|                 (
 | |
|                     "%s for %s:%s" % (key_id, user_id, device_id)
 | |
|                     for user_id, user_keys in json_result.items()
 | |
|                     for device_id, device_keys in user_keys.items()
 | |
|                     for key_id, _ in device_keys.items()
 | |
|                 )
 | |
|             ),
 | |
|         )
 | |
| 
 | |
|         log_kv({"one_time_keys": json_result, "failures": failures})
 | |
|         return {"one_time_keys": json_result, "failures": failures}
 | |
| 
 | |
|     @tag_args
 | |
|     async def upload_keys_for_user(
 | |
|         self, user_id: str, device_id: str, keys: JsonDict
 | |
|     ) -> JsonDict:
 | |
| 
 | |
|         time_now = self.clock.time_msec()
 | |
| 
 | |
|         # TODO: Validate the JSON to make sure it has the right keys.
 | |
|         device_keys = keys.get("device_keys", None)
 | |
|         if device_keys:
 | |
|             logger.info(
 | |
|                 "Updating device_keys for device %r for user %s at %d",
 | |
|                 device_id,
 | |
|                 user_id,
 | |
|                 time_now,
 | |
|             )
 | |
|             log_kv(
 | |
|                 {
 | |
|                     "message": "Updating device_keys for user.",
 | |
|                     "user_id": user_id,
 | |
|                     "device_id": device_id,
 | |
|                 }
 | |
|             )
 | |
|             # TODO: Sign the JSON with the server key
 | |
|             changed = await self.store.set_e2e_device_keys(
 | |
|                 user_id, device_id, time_now, device_keys
 | |
|             )
 | |
|             if changed:
 | |
|                 # Only notify about device updates *if* the keys actually changed
 | |
|                 await self.device_handler.notify_device_update(user_id, [device_id])
 | |
|         else:
 | |
|             log_kv({"message": "Not updating device_keys for user", "user_id": user_id})
 | |
|         one_time_keys = keys.get("one_time_keys", None)
 | |
|         if one_time_keys:
 | |
|             log_kv(
 | |
|                 {
 | |
|                     "message": "Updating one_time_keys for device.",
 | |
|                     "user_id": user_id,
 | |
|                     "device_id": device_id,
 | |
|                 }
 | |
|             )
 | |
|             await self._upload_one_time_keys_for_user(
 | |
|                 user_id, device_id, time_now, one_time_keys
 | |
|             )
 | |
|         else:
 | |
|             log_kv(
 | |
|                 {"message": "Did not update one_time_keys", "reason": "no keys given"}
 | |
|             )
 | |
|         fallback_keys = keys.get("fallback_keys") or keys.get(
 | |
|             "org.matrix.msc2732.fallback_keys"
 | |
|         )
 | |
|         if fallback_keys and isinstance(fallback_keys, dict):
 | |
|             log_kv(
 | |
|                 {
 | |
|                     "message": "Updating fallback_keys for device.",
 | |
|                     "user_id": user_id,
 | |
|                     "device_id": device_id,
 | |
|                 }
 | |
|             )
 | |
|             await self.store.set_e2e_fallback_keys(user_id, device_id, fallback_keys)
 | |
|         elif fallback_keys:
 | |
|             log_kv({"message": "Did not update fallback_keys", "reason": "not a dict"})
 | |
|         else:
 | |
|             log_kv(
 | |
|                 {"message": "Did not update fallback_keys", "reason": "no keys given"}
 | |
|             )
 | |
| 
 | |
|         # the device should have been registered already, but it may have been
 | |
|         # deleted due to a race with a DELETE request. Or we may be using an
 | |
|         # old access_token without an associated device_id. Either way, we
 | |
|         # need to double-check the device is registered to avoid ending up with
 | |
|         # keys without a corresponding device.
 | |
|         await self.device_handler.check_device_registered(user_id, device_id)
 | |
| 
 | |
|         result = await self.store.count_e2e_one_time_keys(user_id, device_id)
 | |
| 
 | |
|         set_tag("one_time_key_counts", str(result))
 | |
|         return {"one_time_key_counts": result}
 | |
| 
 | |
|     async def _upload_one_time_keys_for_user(
 | |
|         self, user_id: str, device_id: str, time_now: int, one_time_keys: JsonDict
 | |
|     ) -> None:
 | |
|         logger.info(
 | |
|             "Adding one_time_keys %r for device %r for user %r at %d",
 | |
|             one_time_keys.keys(),
 | |
|             device_id,
 | |
|             user_id,
 | |
|             time_now,
 | |
|         )
 | |
| 
 | |
|         # make a list of (alg, id, key) tuples
 | |
|         key_list = []
 | |
|         for key_id, key_obj in one_time_keys.items():
 | |
|             algorithm, key_id = key_id.split(":")
 | |
|             key_list.append((algorithm, key_id, key_obj))
 | |
| 
 | |
|         # First we check if we have already persisted any of the keys.
 | |
|         existing_key_map = await self.store.get_e2e_one_time_keys(
 | |
|             user_id, device_id, [k_id for _, k_id, _ in key_list]
 | |
|         )
 | |
| 
 | |
|         new_keys = []  # Keys that we need to insert. (alg, id, json) tuples.
 | |
|         for algorithm, key_id, key in key_list:
 | |
|             ex_json = existing_key_map.get((algorithm, key_id), None)
 | |
|             if ex_json:
 | |
|                 if not _one_time_keys_match(ex_json, key):
 | |
|                     raise SynapseError(
 | |
|                         400,
 | |
|                         (
 | |
|                             "One time key %s:%s already exists. "
 | |
|                             "Old key: %s; new key: %r"
 | |
|                         )
 | |
|                         % (algorithm, key_id, ex_json, key),
 | |
|                     )
 | |
|             else:
 | |
|                 new_keys.append(
 | |
|                     (algorithm, key_id, encode_canonical_json(key).decode("ascii"))
 | |
|                 )
 | |
| 
 | |
|         log_kv({"message": "Inserting new one_time_keys.", "keys": new_keys})
 | |
|         await self.store.add_e2e_one_time_keys(user_id, device_id, time_now, new_keys)
 | |
| 
 | |
|     async def upload_signing_keys_for_user(
 | |
|         self, user_id: str, keys: JsonDict
 | |
|     ) -> JsonDict:
 | |
|         """Upload signing keys for cross-signing
 | |
| 
 | |
|         Args:
 | |
|             user_id: the user uploading the keys
 | |
|             keys: the signing keys
 | |
|         """
 | |
| 
 | |
|         # if a master key is uploaded, then check it.  Otherwise, load the
 | |
|         # stored master key, to check signatures on other keys
 | |
|         if "master_key" in keys:
 | |
|             master_key = keys["master_key"]
 | |
| 
 | |
|             _check_cross_signing_key(master_key, user_id, "master")
 | |
|         else:
 | |
|             master_key = await self.store.get_e2e_cross_signing_key(user_id, "master")
 | |
| 
 | |
|         # if there is no master key, then we can't do anything, because all the
 | |
|         # other cross-signing keys need to be signed by the master key
 | |
|         if not master_key:
 | |
|             raise SynapseError(400, "No master key available", Codes.MISSING_PARAM)
 | |
| 
 | |
|         try:
 | |
|             master_key_id, master_verify_key = get_verify_key_from_cross_signing_key(
 | |
|                 master_key
 | |
|             )
 | |
|         except ValueError:
 | |
|             if "master_key" in keys:
 | |
|                 # the invalid key came from the request
 | |
|                 raise SynapseError(400, "Invalid master key", Codes.INVALID_PARAM)
 | |
|             else:
 | |
|                 # the invalid key came from the database
 | |
|                 logger.error("Invalid master key found for user %s", user_id)
 | |
|                 raise SynapseError(500, "Invalid master key")
 | |
| 
 | |
|         # for the other cross-signing keys, make sure that they have valid
 | |
|         # signatures from the master key
 | |
|         if "self_signing_key" in keys:
 | |
|             self_signing_key = keys["self_signing_key"]
 | |
| 
 | |
|             _check_cross_signing_key(
 | |
|                 self_signing_key, user_id, "self_signing", master_verify_key
 | |
|             )
 | |
| 
 | |
|         if "user_signing_key" in keys:
 | |
|             user_signing_key = keys["user_signing_key"]
 | |
| 
 | |
|             _check_cross_signing_key(
 | |
|                 user_signing_key, user_id, "user_signing", master_verify_key
 | |
|             )
 | |
| 
 | |
|         # if everything checks out, then store the keys and send notifications
 | |
|         deviceids = []
 | |
|         if "master_key" in keys:
 | |
|             await self.store.set_e2e_cross_signing_key(user_id, "master", master_key)
 | |
|             deviceids.append(master_verify_key.version)
 | |
|         if "self_signing_key" in keys:
 | |
|             await self.store.set_e2e_cross_signing_key(
 | |
|                 user_id, "self_signing", self_signing_key
 | |
|             )
 | |
|             try:
 | |
|                 deviceids.append(
 | |
|                     get_verify_key_from_cross_signing_key(self_signing_key)[1].version
 | |
|                 )
 | |
|             except ValueError:
 | |
|                 raise SynapseError(400, "Invalid self-signing key", Codes.INVALID_PARAM)
 | |
|         if "user_signing_key" in keys:
 | |
|             await self.store.set_e2e_cross_signing_key(
 | |
|                 user_id, "user_signing", user_signing_key
 | |
|             )
 | |
|             # the signature stream matches the semantics that we want for
 | |
|             # user-signing key updates: only the user themselves is notified of
 | |
|             # their own user-signing key updates
 | |
|             await self.device_handler.notify_user_signature_update(user_id, [user_id])
 | |
| 
 | |
|         # master key and self-signing key updates match the semantics of device
 | |
|         # list updates: all users who share an encrypted room are notified
 | |
|         if len(deviceids):
 | |
|             await self.device_handler.notify_device_update(user_id, deviceids)
 | |
| 
 | |
|         return {}
 | |
| 
 | |
|     async def upload_signatures_for_device_keys(
 | |
|         self, user_id: str, signatures: JsonDict
 | |
|     ) -> JsonDict:
 | |
|         """Upload device signatures for cross-signing
 | |
| 
 | |
|         Args:
 | |
|             user_id: the user uploading the signatures
 | |
|             signatures: map of users to devices to signed keys. This is the submission
 | |
|             from the user; an exception will be raised if it is malformed.
 | |
|         Returns:
 | |
|             The response to be sent back to the client.  The response will have
 | |
|                 a "failures" key, which will be a dict mapping users to devices
 | |
|                 to errors for the signatures that failed.
 | |
|         Raises:
 | |
|             SynapseError: if the signatures dict is not valid.
 | |
|         """
 | |
|         failures = {}
 | |
| 
 | |
|         # signatures to be stored.  Each item will be a SignatureListItem
 | |
|         signature_list = []
 | |
| 
 | |
|         # split between checking signatures for own user and signatures for
 | |
|         # other users, since we verify them with different keys
 | |
|         self_signatures = signatures.get(user_id, {})
 | |
|         other_signatures = {k: v for k, v in signatures.items() if k != user_id}
 | |
| 
 | |
|         self_signature_list, self_failures = await self._process_self_signatures(
 | |
|             user_id, self_signatures
 | |
|         )
 | |
|         signature_list.extend(self_signature_list)
 | |
|         failures.update(self_failures)
 | |
| 
 | |
|         other_signature_list, other_failures = await self._process_other_signatures(
 | |
|             user_id, other_signatures
 | |
|         )
 | |
|         signature_list.extend(other_signature_list)
 | |
|         failures.update(other_failures)
 | |
| 
 | |
|         # store the signature, and send the appropriate notifications for sync
 | |
|         logger.debug("upload signature failures: %r", failures)
 | |
|         await self.store.store_e2e_cross_signing_signatures(user_id, signature_list)
 | |
| 
 | |
|         self_device_ids = [item.target_device_id for item in self_signature_list]
 | |
|         if self_device_ids:
 | |
|             await self.device_handler.notify_device_update(user_id, self_device_ids)
 | |
|         signed_users = [item.target_user_id for item in other_signature_list]
 | |
|         if signed_users:
 | |
|             await self.device_handler.notify_user_signature_update(
 | |
|                 user_id, signed_users
 | |
|             )
 | |
| 
 | |
|         return {"failures": failures}
 | |
| 
 | |
|     async def _process_self_signatures(
 | |
|         self, user_id: str, signatures: JsonDict
 | |
|     ) -> Tuple[List["SignatureListItem"], Dict[str, Dict[str, dict]]]:
 | |
|         """Process uploaded signatures of the user's own keys.
 | |
| 
 | |
|         Signatures of the user's own keys from this API come in two forms:
 | |
|         - signatures of the user's devices by the user's self-signing key,
 | |
|         - signatures of the user's master key by the user's devices.
 | |
| 
 | |
|         Args:
 | |
|             user_id (string): the user uploading the keys
 | |
|             signatures (dict[string, dict]): map of devices to signed keys
 | |
| 
 | |
|         Returns:
 | |
|             A tuple of a list of signatures to store, and a map of users to
 | |
|             devices to failure reasons
 | |
| 
 | |
|         Raises:
 | |
|             SynapseError: if the input is malformed
 | |
|         """
 | |
|         signature_list: List["SignatureListItem"] = []
 | |
|         failures: Dict[str, Dict[str, JsonDict]] = {}
 | |
|         if not signatures:
 | |
|             return signature_list, failures
 | |
| 
 | |
|         if not isinstance(signatures, dict):
 | |
|             raise SynapseError(400, "Invalid parameter", Codes.INVALID_PARAM)
 | |
| 
 | |
|         try:
 | |
|             # get our self-signing key to verify the signatures
 | |
|             (
 | |
|                 _,
 | |
|                 self_signing_key_id,
 | |
|                 self_signing_verify_key,
 | |
|             ) = await self._get_e2e_cross_signing_verify_key(user_id, "self_signing")
 | |
| 
 | |
|             # get our master key, since we may have received a signature of it.
 | |
|             # We need to fetch it here so that we know what its key ID is, so
 | |
|             # that we can check if a signature that was sent is a signature of
 | |
|             # the master key or of a device
 | |
|             (
 | |
|                 master_key,
 | |
|                 _,
 | |
|                 master_verify_key,
 | |
|             ) = await self._get_e2e_cross_signing_verify_key(user_id, "master")
 | |
| 
 | |
|             # fetch our stored devices.  This is used to 1. verify
 | |
|             # signatures on the master key, and 2. to compare with what
 | |
|             # was sent if the device was signed
 | |
|             devices = await self.store.get_e2e_device_keys_for_cs_api([(user_id, None)])
 | |
| 
 | |
|             if user_id not in devices:
 | |
|                 raise NotFoundError("No device keys found")
 | |
| 
 | |
|             devices = devices[user_id]
 | |
|         except SynapseError as e:
 | |
|             failure = _exception_to_failure(e)
 | |
|             failures[user_id] = {device: failure for device in signatures.keys()}
 | |
|             return signature_list, failures
 | |
| 
 | |
|         for device_id, device in signatures.items():
 | |
|             # make sure submitted data is in the right form
 | |
|             if not isinstance(device, dict):
 | |
|                 raise SynapseError(400, "Invalid parameter", Codes.INVALID_PARAM)
 | |
| 
 | |
|             try:
 | |
|                 if "signatures" not in device or user_id not in device["signatures"]:
 | |
|                     # no signature was sent
 | |
|                     raise SynapseError(
 | |
|                         400, "Invalid signature", Codes.INVALID_SIGNATURE
 | |
|                     )
 | |
| 
 | |
|                 if device_id == master_verify_key.version:
 | |
|                     # The signature is of the master key. This needs to be
 | |
|                     # handled differently from signatures of normal devices.
 | |
|                     master_key_signature_list = self._check_master_key_signature(
 | |
|                         user_id, device_id, device, master_key, devices
 | |
|                     )
 | |
|                     signature_list.extend(master_key_signature_list)
 | |
|                     continue
 | |
| 
 | |
|                 # at this point, we have a device that should be signed
 | |
|                 # by the self-signing key
 | |
|                 if self_signing_key_id not in device["signatures"][user_id]:
 | |
|                     # no signature was sent
 | |
|                     raise SynapseError(
 | |
|                         400, "Invalid signature", Codes.INVALID_SIGNATURE
 | |
|                     )
 | |
| 
 | |
|                 try:
 | |
|                     stored_device = devices[device_id]
 | |
|                 except KeyError:
 | |
|                     raise NotFoundError("Unknown device")
 | |
|                 if self_signing_key_id in stored_device.get("signatures", {}).get(
 | |
|                     user_id, {}
 | |
|                 ):
 | |
|                     # we already have a signature on this device, so we
 | |
|                     # can skip it, since it should be exactly the same
 | |
|                     continue
 | |
| 
 | |
|                 _check_device_signature(
 | |
|                     user_id, self_signing_verify_key, device, stored_device
 | |
|                 )
 | |
| 
 | |
|                 signature = device["signatures"][user_id][self_signing_key_id]
 | |
|                 signature_list.append(
 | |
|                     SignatureListItem(
 | |
|                         self_signing_key_id, user_id, device_id, signature
 | |
|                     )
 | |
|                 )
 | |
|             except SynapseError as e:
 | |
|                 failures.setdefault(user_id, {})[device_id] = _exception_to_failure(e)
 | |
| 
 | |
|         return signature_list, failures
 | |
| 
 | |
|     def _check_master_key_signature(
 | |
|         self,
 | |
|         user_id: str,
 | |
|         master_key_id: str,
 | |
|         signed_master_key: JsonDict,
 | |
|         stored_master_key: JsonDict,
 | |
|         devices: Dict[str, Dict[str, JsonDict]],
 | |
|     ) -> List["SignatureListItem"]:
 | |
|         """Check signatures of a user's master key made by their devices.
 | |
| 
 | |
|         Args:
 | |
|             user_id: the user whose master key is being checked
 | |
|             master_key_id: the ID of the user's master key
 | |
|             signed_master_key: the user's signed master key that was uploaded
 | |
|             stored_master_key: our previously-stored copy of the user's master key
 | |
|             devices: the user's devices
 | |
| 
 | |
|         Returns:
 | |
|             A list of signatures to store
 | |
| 
 | |
|         Raises:
 | |
|             SynapseError: if a signature is invalid
 | |
|         """
 | |
|         # for each device that signed the master key, check the signature.
 | |
|         master_key_signature_list = []
 | |
|         sigs = signed_master_key["signatures"]
 | |
|         for signing_key_id, signature in sigs[user_id].items():
 | |
|             _, signing_device_id = signing_key_id.split(":", 1)
 | |
|             if (
 | |
|                 signing_device_id not in devices
 | |
|                 or signing_key_id not in devices[signing_device_id]["keys"]
 | |
|             ):
 | |
|                 # signed by an unknown device, or the
 | |
|                 # device does not have the key
 | |
|                 raise SynapseError(400, "Invalid signature", Codes.INVALID_SIGNATURE)
 | |
| 
 | |
|             # get the key and check the signature
 | |
|             pubkey = devices[signing_device_id]["keys"][signing_key_id]
 | |
|             verify_key = decode_verify_key_bytes(signing_key_id, decode_base64(pubkey))
 | |
|             _check_device_signature(
 | |
|                 user_id, verify_key, signed_master_key, stored_master_key
 | |
|             )
 | |
| 
 | |
|             master_key_signature_list.append(
 | |
|                 SignatureListItem(signing_key_id, user_id, master_key_id, signature)
 | |
|             )
 | |
| 
 | |
|         return master_key_signature_list
 | |
| 
 | |
|     async def _process_other_signatures(
 | |
|         self, user_id: str, signatures: Dict[str, dict]
 | |
|     ) -> Tuple[List["SignatureListItem"], Dict[str, Dict[str, dict]]]:
 | |
|         """Process uploaded signatures of other users' keys.  These will be the
 | |
|         target user's master keys, signed by the uploading user's user-signing
 | |
|         key.
 | |
| 
 | |
|         Args:
 | |
|             user_id: the user uploading the keys
 | |
|             signatures: map of users to devices to signed keys
 | |
| 
 | |
|         Returns:
 | |
|             A list of signatures to store, and a map of users to devices to failure
 | |
|             reasons
 | |
| 
 | |
|         Raises:
 | |
|             SynapseError: if the input is malformed
 | |
|         """
 | |
|         signature_list: List["SignatureListItem"] = []
 | |
|         failures: Dict[str, Dict[str, JsonDict]] = {}
 | |
|         if not signatures:
 | |
|             return signature_list, failures
 | |
| 
 | |
|         try:
 | |
|             # get our user-signing key to verify the signatures
 | |
|             (
 | |
|                 user_signing_key,
 | |
|                 user_signing_key_id,
 | |
|                 user_signing_verify_key,
 | |
|             ) = await self._get_e2e_cross_signing_verify_key(user_id, "user_signing")
 | |
|         except SynapseError as e:
 | |
|             failure = _exception_to_failure(e)
 | |
|             for user, devicemap in signatures.items():
 | |
|                 failures[user] = {device_id: failure for device_id in devicemap.keys()}
 | |
|             return signature_list, failures
 | |
| 
 | |
|         for target_user, devicemap in signatures.items():
 | |
|             # make sure submitted data is in the right form
 | |
|             if not isinstance(devicemap, dict):
 | |
|                 raise SynapseError(400, "Invalid parameter", Codes.INVALID_PARAM)
 | |
|             for device in devicemap.values():
 | |
|                 if not isinstance(device, dict):
 | |
|                     raise SynapseError(400, "Invalid parameter", Codes.INVALID_PARAM)
 | |
| 
 | |
|             device_id = None
 | |
|             try:
 | |
|                 # get the target user's master key, to make sure it matches
 | |
|                 # what was sent
 | |
|                 (
 | |
|                     master_key,
 | |
|                     master_key_id,
 | |
|                     _,
 | |
|                 ) = await self._get_e2e_cross_signing_verify_key(
 | |
|                     target_user, "master", user_id
 | |
|                 )
 | |
| 
 | |
|                 # make sure that the target user's master key is the one that
 | |
|                 # was signed (and no others)
 | |
|                 device_id = master_key_id.split(":", 1)[1]
 | |
|                 if device_id not in devicemap:
 | |
|                     logger.debug(
 | |
|                         "upload signature: could not find signature for device %s",
 | |
|                         device_id,
 | |
|                     )
 | |
|                     # set device to None so that the failure gets
 | |
|                     # marked on all the signatures
 | |
|                     device_id = None
 | |
|                     raise NotFoundError("Unknown device")
 | |
|                 key = devicemap[device_id]
 | |
|                 other_devices = [k for k in devicemap.keys() if k != device_id]
 | |
|                 if other_devices:
 | |
|                     # other devices were signed -- mark those as failures
 | |
|                     logger.debug("upload signature: too many devices specified")
 | |
|                     failure = _exception_to_failure(NotFoundError("Unknown device"))
 | |
|                     failures[target_user] = {
 | |
|                         device: failure for device in other_devices
 | |
|                     }
 | |
| 
 | |
|                 if user_signing_key_id in master_key.get("signatures", {}).get(
 | |
|                     user_id, {}
 | |
|                 ):
 | |
|                     # we already have the signature, so we can skip it
 | |
|                     continue
 | |
| 
 | |
|                 _check_device_signature(
 | |
|                     user_id, user_signing_verify_key, key, master_key
 | |
|                 )
 | |
| 
 | |
|                 signature = key["signatures"][user_id][user_signing_key_id]
 | |
|                 signature_list.append(
 | |
|                     SignatureListItem(
 | |
|                         user_signing_key_id, target_user, device_id, signature
 | |
|                     )
 | |
|                 )
 | |
|             except SynapseError as e:
 | |
|                 failure = _exception_to_failure(e)
 | |
|                 if device_id is None:
 | |
|                     failures[target_user] = {
 | |
|                         device_id: failure for device_id in devicemap.keys()
 | |
|                     }
 | |
|                 else:
 | |
|                     failures.setdefault(target_user, {})[device_id] = failure
 | |
| 
 | |
|         return signature_list, failures
 | |
| 
 | |
|     async def _get_e2e_cross_signing_verify_key(
 | |
|         self, user_id: str, key_type: str, from_user_id: Optional[str] = None
 | |
|     ) -> Tuple[JsonDict, str, VerifyKey]:
 | |
|         """Fetch locally or remotely query for a cross-signing public key.
 | |
| 
 | |
|         First, attempt to fetch the cross-signing public key from storage.
 | |
|         If that fails, query the keys from the homeserver they belong to
 | |
|         and update our local copy.
 | |
| 
 | |
|         Args:
 | |
|             user_id: the user whose key should be fetched
 | |
|             key_type: the type of key to fetch
 | |
|             from_user_id: the user that we are fetching the keys for.
 | |
|                 This affects what signatures are fetched.
 | |
| 
 | |
|         Returns:
 | |
|             The raw key data, the key ID, and the signedjson verify key
 | |
| 
 | |
|         Raises:
 | |
|             NotFoundError: if the key is not found
 | |
|             SynapseError: if `user_id` is invalid
 | |
|         """
 | |
|         user = UserID.from_string(user_id)
 | |
|         key = await self.store.get_e2e_cross_signing_key(
 | |
|             user_id, key_type, from_user_id
 | |
|         )
 | |
| 
 | |
|         if key:
 | |
|             # We found a copy of this key in our database. Decode and return it
 | |
|             key_id, verify_key = get_verify_key_from_cross_signing_key(key)
 | |
|             return key, key_id, verify_key
 | |
| 
 | |
|         # If we couldn't find the key locally, and we're looking for keys of
 | |
|         # another user then attempt to fetch the missing key from the remote
 | |
|         # user's server.
 | |
|         #
 | |
|         # We may run into this in possible edge cases where a user tries to
 | |
|         # cross-sign a remote user, but does not share any rooms with them yet.
 | |
|         # Thus, we would not have their key list yet. We instead fetch the key,
 | |
|         # store it and notify clients of new, associated device IDs.
 | |
|         if self.is_mine(user) or key_type not in ["master", "self_signing"]:
 | |
|             # Note that master and self_signing keys are the only cross-signing keys we
 | |
|             # can request over federation
 | |
|             raise NotFoundError("No %s key found for %s" % (key_type, user_id))
 | |
| 
 | |
|         cross_signing_keys = await self._retrieve_cross_signing_keys_for_remote_user(
 | |
|             user, key_type
 | |
|         )
 | |
|         if cross_signing_keys is None:
 | |
|             raise NotFoundError("No %s key found for %s" % (key_type, user_id))
 | |
| 
 | |
|         return cross_signing_keys
 | |
| 
 | |
|     async def _retrieve_cross_signing_keys_for_remote_user(
 | |
|         self,
 | |
|         user: UserID,
 | |
|         desired_key_type: str,
 | |
|     ) -> Optional[Tuple[Dict[str, Any], str, VerifyKey]]:
 | |
|         """Queries cross-signing keys for a remote user and saves them to the database
 | |
| 
 | |
|         Only the key specified by `key_type` will be returned, while all retrieved keys
 | |
|         will be saved regardless
 | |
| 
 | |
|         Args:
 | |
|             user: The user to query remote keys for
 | |
|             desired_key_type: The type of key to receive. One of "master", "self_signing"
 | |
| 
 | |
|         Returns:
 | |
|             A tuple of the retrieved key content, the key's ID and the matching VerifyKey.
 | |
|             If the key cannot be retrieved, all values in the tuple will instead be None.
 | |
|         """
 | |
|         try:
 | |
|             remote_result = await self.federation.query_user_devices(
 | |
|                 user.domain, user.to_string()
 | |
|             )
 | |
|         except Exception as e:
 | |
|             logger.warning(
 | |
|                 "Unable to query %s for cross-signing keys of user %s: %s %s",
 | |
|                 user.domain,
 | |
|                 user.to_string(),
 | |
|                 type(e),
 | |
|                 e,
 | |
|             )
 | |
|             return None
 | |
| 
 | |
|         # Process each of the retrieved cross-signing keys
 | |
|         desired_key_data = None
 | |
|         retrieved_device_ids = []
 | |
|         for key_type in ["master", "self_signing"]:
 | |
|             key_content = remote_result.get(key_type + "_key")
 | |
|             if not key_content:
 | |
|                 continue
 | |
| 
 | |
|             # Ensure these keys belong to the correct user
 | |
|             if "user_id" not in key_content:
 | |
|                 logger.warning(
 | |
|                     "Invalid %s key retrieved, missing user_id field: %s",
 | |
|                     key_type,
 | |
|                     key_content,
 | |
|                 )
 | |
|                 continue
 | |
|             if user.to_string() != key_content["user_id"]:
 | |
|                 logger.warning(
 | |
|                     "Found %s key of user %s when querying for keys of user %s",
 | |
|                     key_type,
 | |
|                     key_content["user_id"],
 | |
|                     user.to_string(),
 | |
|                 )
 | |
|                 continue
 | |
| 
 | |
|             # Validate the key contents
 | |
|             try:
 | |
|                 # verify_key is a VerifyKey from signedjson, which uses
 | |
|                 # .version to denote the portion of the key ID after the
 | |
|                 # algorithm and colon, which is the device ID
 | |
|                 key_id, verify_key = get_verify_key_from_cross_signing_key(key_content)
 | |
|             except ValueError as e:
 | |
|                 logger.warning(
 | |
|                     "Invalid %s key retrieved: %s - %s %s",
 | |
|                     key_type,
 | |
|                     key_content,
 | |
|                     type(e),
 | |
|                     e,
 | |
|                 )
 | |
|                 continue
 | |
| 
 | |
|             # Note down the device ID attached to this key
 | |
|             retrieved_device_ids.append(verify_key.version)
 | |
| 
 | |
|             # If this is the desired key type, save it and its ID/VerifyKey
 | |
|             if key_type == desired_key_type:
 | |
|                 desired_key_data = key_content, key_id, verify_key
 | |
| 
 | |
|             # At the same time, store this key in the db for subsequent queries
 | |
|             await self.store.set_e2e_cross_signing_key(
 | |
|                 user.to_string(), key_type, key_content
 | |
|             )
 | |
| 
 | |
|         # Notify clients that new devices for this user have been discovered
 | |
|         if retrieved_device_ids:
 | |
|             # XXX is this necessary?
 | |
|             await self.device_handler.notify_device_update(
 | |
|                 user.to_string(), retrieved_device_ids
 | |
|             )
 | |
| 
 | |
|         return desired_key_data
 | |
| 
 | |
| 
 | |
| def _check_cross_signing_key(
 | |
|     key: JsonDict, user_id: str, key_type: str, signing_key: Optional[VerifyKey] = None
 | |
| ) -> None:
 | |
|     """Check a cross-signing key uploaded by a user.  Performs some basic sanity
 | |
|     checking, and ensures that it is signed, if a signature is required.
 | |
| 
 | |
|     Args:
 | |
|         key: the key data to verify
 | |
|         user_id: the user whose key is being checked
 | |
|         key_type: the type of key that the key should be
 | |
|         signing_key: the signing key that the key should be signed with.  If
 | |
|             omitted, signatures will not be checked.
 | |
|     """
 | |
|     if (
 | |
|         key.get("user_id") != user_id
 | |
|         or key_type not in key.get("usage", [])
 | |
|         or len(key.get("keys", {})) != 1
 | |
|     ):
 | |
|         raise SynapseError(400, ("Invalid %s key" % (key_type,)), Codes.INVALID_PARAM)
 | |
| 
 | |
|     if signing_key:
 | |
|         try:
 | |
|             verify_signed_json(key, user_id, signing_key)
 | |
|         except SignatureVerifyException:
 | |
|             raise SynapseError(
 | |
|                 400, ("Invalid signature on %s key" % key_type), Codes.INVALID_SIGNATURE
 | |
|             )
 | |
| 
 | |
| 
 | |
| def _check_device_signature(
 | |
|     user_id: str,
 | |
|     verify_key: VerifyKey,
 | |
|     signed_device: JsonDict,
 | |
|     stored_device: JsonDict,
 | |
| ) -> None:
 | |
|     """Check that a signature on a device or cross-signing key is correct and
 | |
|     matches the copy of the device/key that we have stored.  Throws an
 | |
|     exception if an error is detected.
 | |
| 
 | |
|     Args:
 | |
|         user_id: the user ID whose signature is being checked
 | |
|         verify_key: the key to verify the device with
 | |
|         signed_device: the uploaded signed device data
 | |
|         stored_device: our previously stored copy of the device
 | |
| 
 | |
|     Raises:
 | |
|         SynapseError: if the signature was invalid or the sent device is not the
 | |
|             same as the stored device
 | |
| 
 | |
|     """
 | |
| 
 | |
|     # make sure that the device submitted matches what we have stored
 | |
|     stripped_signed_device = {
 | |
|         k: v for k, v in signed_device.items() if k not in ["signatures", "unsigned"]
 | |
|     }
 | |
|     stripped_stored_device = {
 | |
|         k: v for k, v in stored_device.items() if k not in ["signatures", "unsigned"]
 | |
|     }
 | |
|     if stripped_signed_device != stripped_stored_device:
 | |
|         logger.debug(
 | |
|             "upload signatures: key does not match %s vs %s",
 | |
|             signed_device,
 | |
|             stored_device,
 | |
|         )
 | |
|         raise SynapseError(400, "Key does not match")
 | |
| 
 | |
|     try:
 | |
|         verify_signed_json(signed_device, user_id, verify_key)
 | |
|     except SignatureVerifyException:
 | |
|         logger.debug("invalid signature on key")
 | |
|         raise SynapseError(400, "Invalid signature", Codes.INVALID_SIGNATURE)
 | |
| 
 | |
| 
 | |
| def _exception_to_failure(e: Exception) -> JsonDict:
 | |
|     if isinstance(e, SynapseError):
 | |
|         return {"status": e.code, "errcode": e.errcode, "message": str(e)}
 | |
| 
 | |
|     if isinstance(e, CodeMessageException):
 | |
|         return {"status": e.code, "message": str(e)}
 | |
| 
 | |
|     if isinstance(e, NotRetryingDestination):
 | |
|         return {"status": 503, "message": "Not ready for retry"}
 | |
| 
 | |
|     # include ConnectionRefused and other errors
 | |
|     #
 | |
|     # Note that some Exceptions (notably twisted's ResponseFailed etc) don't
 | |
|     # give a string for e.message, which json then fails to serialize.
 | |
|     return {"status": 503, "message": str(e)}
 | |
| 
 | |
| 
 | |
| def _one_time_keys_match(old_key_json: str, new_key: JsonDict) -> bool:
 | |
|     old_key = json_decoder.decode(old_key_json)
 | |
| 
 | |
|     # if either is a string rather than an object, they must match exactly
 | |
|     if not isinstance(old_key, dict) or not isinstance(new_key, dict):
 | |
|         return old_key == new_key
 | |
| 
 | |
|     # otherwise, we strip off the 'signatures' if any, because it's legitimate
 | |
|     # for different upload attempts to have different signatures.
 | |
|     old_key.pop("signatures", None)
 | |
|     new_key_copy = dict(new_key)
 | |
|     new_key_copy.pop("signatures", None)
 | |
| 
 | |
|     return old_key == new_key_copy
 | |
| 
 | |
| 
 | |
| @attr.s(slots=True, auto_attribs=True)
 | |
| class SignatureListItem:
 | |
|     """An item in the signature list as used by upload_signatures_for_device_keys."""
 | |
| 
 | |
|     signing_key_id: str
 | |
|     target_user_id: str
 | |
|     target_device_id: str
 | |
|     signature: JsonDict
 | |
| 
 | |
| 
 | |
| class SigningKeyEduUpdater:
 | |
|     """Handles incoming signing key updates from federation and updates the DB"""
 | |
| 
 | |
|     def __init__(self, hs: "HomeServer", e2e_keys_handler: E2eKeysHandler):
 | |
|         self.store = hs.get_datastores().main
 | |
|         self.federation = hs.get_federation_client()
 | |
|         self.clock = hs.get_clock()
 | |
|         self.e2e_keys_handler = e2e_keys_handler
 | |
| 
 | |
|         self._remote_edu_linearizer = Linearizer(name="remote_signing_key")
 | |
| 
 | |
|         # user_id -> list of updates waiting to be handled.
 | |
|         self._pending_updates: Dict[str, List[Tuple[JsonDict, JsonDict]]] = {}
 | |
| 
 | |
|     async def incoming_signing_key_update(
 | |
|         self, origin: str, edu_content: JsonDict
 | |
|     ) -> None:
 | |
|         """Called on incoming signing key update from federation. Responsible for
 | |
|         parsing the EDU and adding to pending updates list.
 | |
| 
 | |
|         Args:
 | |
|             origin: the server that sent the EDU
 | |
|             edu_content: the contents of the EDU
 | |
|         """
 | |
| 
 | |
|         user_id = edu_content.pop("user_id")
 | |
|         master_key = edu_content.pop("master_key", None)
 | |
|         self_signing_key = edu_content.pop("self_signing_key", None)
 | |
| 
 | |
|         if get_domain_from_id(user_id) != origin:
 | |
|             logger.warning("Got signing key update edu for %r from %r", user_id, origin)
 | |
|             return
 | |
| 
 | |
|         room_ids = await self.store.get_rooms_for_user(user_id)
 | |
|         if not room_ids:
 | |
|             # We don't share any rooms with this user. Ignore update, as we
 | |
|             # probably won't get any further updates.
 | |
|             return
 | |
| 
 | |
|         self._pending_updates.setdefault(user_id, []).append(
 | |
|             (master_key, self_signing_key)
 | |
|         )
 | |
| 
 | |
|         await self._handle_signing_key_updates(user_id)
 | |
| 
 | |
|     async def _handle_signing_key_updates(self, user_id: str) -> None:
 | |
|         """Actually handle pending updates.
 | |
| 
 | |
|         Args:
 | |
|             user_id: the user whose updates we are processing
 | |
|         """
 | |
| 
 | |
|         device_handler = self.e2e_keys_handler.device_handler
 | |
|         device_list_updater = device_handler.device_list_updater
 | |
| 
 | |
|         async with self._remote_edu_linearizer.queue(user_id):
 | |
|             pending_updates = self._pending_updates.pop(user_id, [])
 | |
|             if not pending_updates:
 | |
|                 # This can happen since we batch updates
 | |
|                 return
 | |
| 
 | |
|             device_ids: List[str] = []
 | |
| 
 | |
|             logger.info("pending updates: %r", pending_updates)
 | |
| 
 | |
|             for master_key, self_signing_key in pending_updates:
 | |
|                 new_device_ids = (
 | |
|                     await device_list_updater.process_cross_signing_key_update(
 | |
|                         user_id,
 | |
|                         master_key,
 | |
|                         self_signing_key,
 | |
|                     )
 | |
|                 )
 | |
|                 device_ids = device_ids + new_device_ids
 | |
| 
 | |
|             await device_handler.notify_device_update(user_id, device_ids)
 |