Process cross-signing keys when resyncing device lists (#7594)

It looks like `user_device_resync` was ignoring cross-signing keys from the results received from the remote server. This patch fixes this, by processing these keys using the same process `_handle_signing_key_updates` does (and effectively factor that part out of that function).
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Brendan Abolivier 2020-06-01 17:47:30 +02:00 committed by GitHub
parent 901b1fa561
commit 33c39ab93c
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4 changed files with 119 additions and 18 deletions

1
changelog.d/7594.bugfix Normal file
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@ -0,0 +1 @@
Fix a bug causing the cross-signing keys to be ignored when resyncing a device list.

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@ -15,6 +15,7 @@
# See the License for the specific language governing permissions and
# limitations under the License.
import logging
from typing import Any, Dict, Optional
from six import iteritems, itervalues
@ -30,7 +31,11 @@ from synapse.api.errors import (
)
from synapse.logging.opentracing import log_kv, set_tag, trace
from synapse.metrics.background_process_metrics import run_as_background_process
from synapse.types import RoomStreamToken, get_domain_from_id
from synapse.types import (
RoomStreamToken,
get_domain_from_id,
get_verify_key_from_cross_signing_key,
)
from synapse.util import stringutils
from synapse.util.async_helpers import Linearizer
from synapse.util.caches.expiringcache import ExpiringCache
@ -795,6 +800,13 @@ class DeviceListUpdater(object):
stream_id = result["stream_id"]
devices = result["devices"]
# Get the master key and the self-signing key for this user if provided in the
# response (None if not in the response).
# The response will not contain the user signing key, as this key is only used by
# its owner, thus it doesn't make sense to send it over federation.
master_key = result.get("master_key")
self_signing_key = result.get("self_signing_key")
# If the remote server has more than ~1000 devices for this user
# we assume that something is going horribly wrong (e.g. a bot
# that logs in and creates a new device every time it tries to
@ -824,6 +836,13 @@ class DeviceListUpdater(object):
yield self.store.update_remote_device_list_cache(user_id, devices, stream_id)
device_ids = [device["device_id"] for device in devices]
# Handle cross-signing keys.
cross_signing_device_ids = yield self.process_cross_signing_key_update(
user_id, master_key, self_signing_key,
)
device_ids = device_ids + cross_signing_device_ids
yield self.device_handler.notify_device_update(user_id, device_ids)
# We clobber the seen updates since we've re-synced from a given
@ -831,3 +850,40 @@ class DeviceListUpdater(object):
self._seen_updates[user_id] = {stream_id}
defer.returnValue(result)
@defer.inlineCallbacks
def process_cross_signing_key_update(
self,
user_id: str,
master_key: Optional[Dict[str, Any]],
self_signing_key: Optional[Dict[str, Any]],
) -> list:
"""Process the given new master and self-signing key for the given remote user.
Args:
user_id: The ID of the user these keys are for.
master_key: The dict of the cross-signing master key as returned by the
remote server.
self_signing_key: The dict of the cross-signing self-signing key as returned
by the remote server.
Return:
The device IDs for the given keys.
"""
device_ids = []
if master_key:
yield self.store.set_e2e_cross_signing_key(user_id, "master", master_key)
_, verify_key = get_verify_key_from_cross_signing_key(master_key)
# 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
device_ids.append(verify_key.version)
if self_signing_key:
yield self.store.set_e2e_cross_signing_key(
user_id, "self_signing", self_signing_key
)
_, verify_key = get_verify_key_from_cross_signing_key(self_signing_key)
device_ids.append(verify_key.version)
return device_ids

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@ -1291,6 +1291,7 @@ class SigningKeyEduUpdater(object):
"""
device_handler = self.e2e_keys_handler.device_handler
device_list_updater = device_handler.device_list_updater
with (yield self._remote_edu_linearizer.queue(user_id)):
pending_updates = self._pending_updates.pop(user_id, [])
@ -1303,22 +1304,9 @@ class SigningKeyEduUpdater(object):
logger.info("pending updates: %r", pending_updates)
for master_key, self_signing_key in pending_updates:
if master_key:
yield self.store.set_e2e_cross_signing_key(
user_id, "master", master_key
)
_, verify_key = get_verify_key_from_cross_signing_key(master_key)
# 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
device_ids.append(verify_key.version)
if self_signing_key:
yield self.store.set_e2e_cross_signing_key(
user_id, "self_signing", self_signing_key
)
_, verify_key = get_verify_key_from_cross_signing_key(
self_signing_key
)
device_ids.append(verify_key.version)
new_device_ids = yield device_list_updater.process_cross_signing_key_update(
user_id, master_key, self_signing_key,
)
device_ids = device_ids + new_device_ids
yield device_handler.notify_device_update(user_id, device_ids)

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@ -206,3 +206,59 @@ class MessageAcceptTests(unittest.HomeserverTestCase):
# list.
self.reactor.advance(30)
self.assertEqual(self.resync_attempts, 2)
def test_cross_signing_keys_retry(self):
"""Tests that resyncing a device list correctly processes cross-signing keys from
the remote server.
"""
remote_user_id = "@john:test_remote"
remote_master_key = "85T7JXPFBAySB/jwby4S3lBPTqY3+Zg53nYuGmu1ggY"
remote_self_signing_key = "QeIiFEjluPBtI7WQdG365QKZcFs9kqmHir6RBD0//nQ"
# Register mock device list retrieval on the federation client.
federation_client = self.homeserver.get_federation_client()
federation_client.query_user_devices = Mock(
return_value={
"user_id": remote_user_id,
"stream_id": 1,
"devices": [],
"master_key": {
"user_id": remote_user_id,
"usage": ["master"],
"keys": {"ed25519:" + remote_master_key: remote_master_key},
},
"self_signing_key": {
"user_id": remote_user_id,
"usage": ["self_signing"],
"keys": {
"ed25519:" + remote_self_signing_key: remote_self_signing_key
},
},
}
)
# Resync the device list.
device_handler = self.homeserver.get_device_handler()
self.get_success(
device_handler.device_list_updater.user_device_resync(remote_user_id),
)
# Retrieve the cross-signing keys for this user.
keys = self.get_success(
self.store.get_e2e_cross_signing_keys_bulk(user_ids=[remote_user_id]),
)
self.assertTrue(remote_user_id in keys)
# Check that the master key is the one returned by the mock.
master_key = keys[remote_user_id]["master"]
self.assertEqual(len(master_key["keys"]), 1)
self.assertTrue("ed25519:" + remote_master_key in master_key["keys"].keys())
self.assertTrue(remote_master_key in master_key["keys"].values())
# Check that the self-signing key is the one returned by the mock.
self_signing_key = keys[remote_user_id]["self_signing"]
self.assertEqual(len(self_signing_key["keys"]), 1)
self.assertTrue(
"ed25519:" + remote_self_signing_key in self_signing_key["keys"].keys(),
)
self.assertTrue(remote_self_signing_key in self_signing_key["keys"].values())