forked-synapse/synapse/handlers/e2e_keys.py
2018-06-28 14:49:57 +01:00

379 lines
14 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2016 OpenMarket Ltd
# Copyright 2018 New Vector Ltd
#
# 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 canonicaljson import encode_canonical_json, json
from twisted.internet import defer
from six import iteritems
from synapse.api.errors import (
SynapseError, CodeMessageException, FederationDeniedError,
)
from synapse.types import get_domain_from_id, UserID
from synapse.util.logcontext import make_deferred_yieldable, run_in_background
from synapse.util.retryutils import NotRetryingDestination
logger = logging.getLogger(__name__)
class E2eKeysHandler(object):
def __init__(self, hs):
self.store = hs.get_datastore()
self.federation = hs.get_federation_client()
self.device_handler = hs.get_device_handler()
self.is_mine = hs.is_mine
self.clock = hs.get_clock()
# 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.
hs.get_federation_registry().register_query_handler(
"client_keys", self.on_federation_query_client_keys
)
@defer.inlineCallbacks
def query_devices(self, query_body, timeout):
""" Handle a device key query from a client
{
"device_keys": {
"<user_id>": ["<device_id>"]
}
}
->
{
"device_keys": {
"<user_id>": {
"<device_id>": {
...
}
}
}
}
"""
device_keys_query = 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
# First get local devices.
failures = {}
results = {}
if local_query:
local_result = yield self.query_local_devices(local_query)
for user_id, keys in local_result.items():
if user_id in local_query:
results[user_id] = keys
# Now attempt to get any remote devices from our local cache.
remote_queries_not_in_cache = {}
if remote_queries:
query_list = []
for user_id, device_ids in iteritems(remote_queries):
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 = (
yield self.store.get_user_devices_from_cache(
query_list
)
)
for user_id, devices in iteritems(remote_results):
user_devices = results.setdefault(user_id, {})
for device_id, device in iteritems(devices):
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
for user_id in user_ids_not_in_cache:
domain = get_domain_from_id(user_id)
r = remote_queries_not_in_cache.setdefault(domain, {})
r[user_id] = remote_queries[user_id]
# Now fetch any devices that we don't have in our cache
@defer.inlineCallbacks
def do_remote_query(destination):
destination_query = remote_queries_not_in_cache[destination]
try:
remote_result = yield 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
except Exception as e:
failures[destination] = _exception_to_failure(e)
yield make_deferred_yieldable(defer.gatherResults([
run_in_background(do_remote_query, destination)
for destination in remote_queries_not_in_cache
], consumeErrors=True))
defer.returnValue({
"device_keys": results, "failures": failures,
})
@defer.inlineCallbacks
def query_local_devices(self, query):
"""Get E2E device keys for local users
Args:
query (dict[string, list[string]|None): map from user_id to a list
of devices to query (None for all devices)
Returns:
defer.Deferred: (resolves to dict[string, dict[string, dict]]):
map from user_id -> device_id -> device details
"""
local_query = []
result_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)
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 = yield self.store.get_e2e_device_keys(local_query)
# Build the result structure, un-jsonify the results, and add the
# "unsigned" section
for user_id, device_keys in results.items():
for device_id, device_info in device_keys.items():
r = dict(device_info["keys"])
r["unsigned"] = {}
display_name = device_info["device_display_name"]
if display_name is not None:
r["unsigned"]["device_display_name"] = display_name
result_dict[user_id][device_id] = r
defer.returnValue(result_dict)
@defer.inlineCallbacks
def on_federation_query_client_keys(self, query_body):
""" Handle a device key query from a federated server
"""
device_keys_query = query_body.get("device_keys", {})
res = yield self.query_local_devices(device_keys_query)
defer.returnValue({"device_keys": res})
@defer.inlineCallbacks
def claim_one_time_keys(self, query, timeout):
local_query = []
remote_queries = {}
for user_id, device_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 device_keys.items():
local_query.append((user_id, device_id, algorithm))
else:
domain = get_domain_from_id(user_id)
remote_queries.setdefault(domain, {})[user_id] = device_keys
results = yield self.store.claim_e2e_one_time_keys(local_query)
json_result = {}
failures = {}
for user_id, device_keys in results.items():
for device_id, keys in device_keys.items():
for key_id, json_bytes in keys.items():
json_result.setdefault(user_id, {})[device_id] = {
key_id: json.loads(json_bytes)
}
@defer.inlineCallbacks
def claim_client_keys(destination):
device_keys = remote_queries[destination]
try:
remote_result = yield 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:
failures[destination] = _exception_to_failure(e)
yield 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 iteritems(json_result)
for device_id, device_keys in iteritems(user_keys)
for key_id, _ in iteritems(device_keys)
)),
)
defer.returnValue({
"one_time_keys": json_result,
"failures": failures
})
@defer.inlineCallbacks
def upload_keys_for_user(self, user_id, device_id, keys):
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
)
# TODO: Sign the JSON with the server key
changed = yield 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
yield self.device_handler.notify_device_update(user_id, [device_id])
one_time_keys = keys.get("one_time_keys", None)
if one_time_keys:
yield self._upload_one_time_keys_for_user(
user_id, device_id, time_now, one_time_keys,
)
# 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.
yield self.device_handler.check_device_registered(user_id, device_id)
result = yield self.store.count_e2e_one_time_keys(user_id, device_id)
defer.returnValue({"one_time_key_counts": result})
@defer.inlineCallbacks
def _upload_one_time_keys_for_user(self, user_id, device_id, time_now,
one_time_keys):
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 = yield 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)))
yield self.store.add_e2e_one_time_keys(
user_id, device_id, time_now, new_keys
)
def _exception_to_failure(e):
if isinstance(e, CodeMessageException):
return {
"status": e.code, "message": e.message,
}
if isinstance(e, NotRetryingDestination):
return {
"status": 503, "message": "Not ready for retry",
}
if isinstance(e, FederationDeniedError):
return {
"status": 403, "message": "Federation Denied",
}
# 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.message),
}
def _one_time_keys_match(old_key_json, new_key):
old_key = json.loads(old_key_json)
# if either is a string rather than an object, they must match exactly
if not isinstance(old_key, dict) or not isinstance(new_key, dict):
return old_key == new_key
# otherwise, we strip off the 'signatures' if any, because it's legitimate
# for different upload attempts to have different signatures.
old_key.pop("signatures", None)
new_key_copy = dict(new_key)
new_key_copy.pop("signatures", None)
return old_key == new_key_copy