implement federation parts of cross-signing

This commit is contained in:
Hubert Chathi 2019-05-22 16:42:00 -04:00
parent 2761731634
commit 8d3542a64e
4 changed files with 179 additions and 10 deletions

View file

@ -366,10 +366,10 @@ class PerDestinationQueue(object):
Edu(
origin=self._server_name,
destination=self._destination,
edu_type="m.device_list_update",
edu_type=edu_type,
content=content,
)
for content in results
for (edu_type, content) in results
]
assert len(edus) <= limit, "get_devices_by_remote returned too many EDUs"

View file

@ -458,7 +458,18 @@ class DeviceHandler(DeviceWorkerHandler):
@defer.inlineCallbacks
def on_federation_query_user_devices(self, user_id):
stream_id, devices = yield self.store.get_devices_with_keys_by_user(user_id)
return {"user_id": user_id, "stream_id": stream_id, "devices": devices}
master_key = yield self.store.get_e2e_cross_signing_key(user_id, "master")
self_signing_key = yield self.store.get_e2e_cross_signing_key(
user_id, "self_signing"
)
return {
"user_id": user_id,
"stream_id": stream_id,
"devices": devices,
"master_key": master_key,
"self_signing_key": self_signing_key
}
@defer.inlineCallbacks
def user_left_room(self, user, room_id):

View file

@ -36,6 +36,8 @@ from synapse.types import (
get_verify_key_from_cross_signing_key,
)
from synapse.util import unwrapFirstError
from synapse.util.async_helpers import Linearizer
from synapse.util.caches.expiringcache import ExpiringCache
from synapse.util.retryutils import NotRetryingDestination
logger = logging.getLogger(__name__)
@ -49,10 +51,17 @@ class E2eKeysHandler(object):
self.is_mine = hs.is_mine
self.clock = hs.get_clock()
self._edu_updater = SigningKeyEduUpdater(hs, self)
federation_registry = hs.get_federation_registry()
federation_registry.register_edu_handler(
"m.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.
hs.get_federation_registry().register_query_handler(
federation_registry.register_query_handler(
"client_keys", self.on_federation_query_client_keys
)
@ -343,7 +352,15 @@ class E2eKeysHandler(object):
"""
device_keys_query = query_body.get("device_keys", {})
res = yield self.query_local_devices(device_keys_query)
return {"device_keys": res}
ret = {"device_keys": res}
# add in the cross-signing keys
cross_signing_keys = yield self.query_cross_signing_keys(device_keys_query)
for key, value in iteritems(cross_signing_keys):
ret[key + "_keys"] = value
return ret
@trace
@defer.inlineCallbacks
@ -1047,3 +1064,98 @@ class SignatureListItem:
target_user_id = attr.ib()
target_device_id = attr.ib()
signature = attr.ib()
class SigningKeyEduUpdater(object):
"Handles incoming signing key updates from federation and updates the DB"
def __init__(self, hs, e2e_keys_handler):
self.store = hs.get_datastore()
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 = {}
# Recently seen stream ids. We don't bother keeping these in the DB,
# but they're useful to have them about to reduce the number of spurious
# resyncs.
self._seen_updates = ExpiringCache(
cache_name="signing_key_update_edu",
clock=self.clock,
max_len=10000,
expiry_ms=30 * 60 * 1000,
iterable=True,
)
@defer.inlineCallbacks
def incoming_signing_key_update(self, origin, edu_content):
"""Called on incoming signing key update from federation. Responsible for
parsing the EDU and adding to pending updates list.
Args:
origin (string): the server that sent the EDU
edu_content (dict): 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:
# TODO: Raise?
logger.warning("Got signing key update edu for %r from %r", user_id, origin)
return
room_ids = yield 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, edu_content)
)
yield self._handle_signing_key_updates(user_id)
@defer.inlineCallbacks
def _handle_signing_key_updates(self, user_id):
"""Actually handle pending updates.
Args:
user_id (string): the user whose updates we are processing
"""
device_handler = self.e2e_keys_handler.device_handler
with (yield 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 = []
logger.info("pending updates: %r", pending_updates)
for master_key, self_signing_key, edu_content in pending_updates:
if master_key:
yield self.store.set_e2e_cross_signing_key(
user_id, "master", master_key
)
device_id = \
get_verify_key_from_cross_signing_key(master_key)[1].version
device_ids.append(device_id)
if self_signing_key:
yield self.store.set_e2e_cross_signing_key(
user_id, "self_signing", self_signing_key
)
device_id = \
get_verify_key_from_cross_signing_key(self_signing_key)[1].version
device_ids.append(device_id)
yield device_handler.notify_device_update(user_id, device_ids)

View file

@ -94,9 +94,10 @@ class DeviceWorkerStore(SQLBaseStore):
"""Get stream of updates to send to remote servers
Returns:
Deferred[tuple[int, list[dict]]]:
Deferred[tuple[int, list[tuple[string,dict]]]]:
current stream id (ie, the stream id of the last update included in the
response), and the list of updates
response), and the list of updates, where each update is a pair of EDU
type and EDU contents
"""
now_stream_id = self._device_list_id_gen.get_current_token()
@ -129,6 +130,25 @@ class DeviceWorkerStore(SQLBaseStore):
if not updates:
return now_stream_id, []
# get the cross-signing keys of the users the list
users = set(r[0] for r in updates)
master_key_by_user = {}
self_signing_key_by_user = {}
for user in users:
cross_signing_key = yield self.get_e2e_cross_signing_key(user, "master")
key_id, verify_key = get_verify_key_from_cross_signing_key(cross_signing_key)
master_key_by_user[user] = {
"key_info": cross_signing_key,
"pubkey": verify_key.version
}
cross_signing_key = yield self.get_e2e_cross_signing_key(user, "self_signing")
key_id, verify_key = get_verify_key_from_cross_signing_key(cross_signing_key)
self_signing_key_by_user[user] = {
"key_info": cross_signing_key,
"pubkey": verify_key.version
}
# if we have exceeded the limit, we need to exclude any results with the
# same stream_id as the last row.
if len(updates) > limit:
@ -158,6 +178,10 @@ class DeviceWorkerStore(SQLBaseStore):
# Stop processing updates
break
if update[1] == master_key_by_user[update[0]]["pubkey"] or \
update[1] == self_signing_key_by_user[update[0]]["pubkey"]:
continue
key = (update[0], update[1])
update_context = update[3]
@ -172,16 +196,37 @@ class DeviceWorkerStore(SQLBaseStore):
# means that there are more than limit updates all of which have the same
# steam_id.
# figure out which cross-signing keys were changed by intersecting the
# update list with the master/self-signing key by user maps
cross_signing_keys_by_user = {}
for user_id, device_id, stream in updates:
if device_id == master_key_by_user[user_id]["pubkey"]:
result = cross_signing_keys_by_user.setdefault(user_id, {})
result["master_key"] = \
master_key_by_user[user_id]["key_info"]
elif device_id == self_signing_key_by_user[user_id]["pubkey"]:
result = cross_signing_keys_by_user.setdefault(user_id, {})
result["self_signing_key"] = \
self_signing_key_by_user[user_id]["key_info"]
cross_signing_results = []
# add the updated cross-signing keys to the results list
for user_id, result in iteritems(cross_signing_keys_by_user):
result["user_id"] = user_id
cross_signing_results.append(("m.signing_key_update", result))
# That should only happen if a client is spamming the server with new
# devices, in which case E2E isn't going to work well anyway. We'll just
# skip that stream_id and return an empty list, and continue with the next
# stream_id next time.
if not query_map:
if not query_map and not cross_signing_results:
return stream_id_cutoff, []
results = yield self._get_device_update_edus_by_remote(
destination, from_stream_id, query_map
)
results.extend(cross_signing_results)
return now_stream_id, results
@ -200,6 +245,7 @@ class DeviceWorkerStore(SQLBaseStore):
Returns:
List: List of device updates
"""
# get the list of device updates that need to be sent
sql = """
SELECT user_id, device_id, stream_id, opentracing_context FROM device_lists_outbound_pokes
WHERE destination = ? AND ? < stream_id AND stream_id <= ? AND sent = ?
@ -231,7 +277,7 @@ class DeviceWorkerStore(SQLBaseStore):
query_map.keys(),
include_all_devices=True,
include_deleted_devices=True,
)
) if query_map else {}
results = []
for user_id, user_devices in iteritems(devices):
@ -262,7 +308,7 @@ class DeviceWorkerStore(SQLBaseStore):
else:
result["deleted"] = True
results.append(result)
results.append(("m.device_list_update", result))
return results