Add auth events as per spec. (#6556)

Previously we tried to be clever and filter out some unnecessary event
IDs to keep the auth chain small, but that had some annoying
interactions with state res v2 so we stop doing that for now.
This commit is contained in:
Erik Johnston 2019-12-16 16:59:32 +00:00
parent 6316530366
commit 5ca2cfadc3
2 changed files with 36 additions and 68 deletions

1
changelog.d/6556.bugfix Normal file
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@ -0,0 +1 @@
Fix a cause of state resets in room versions 2 onwards.

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@ -14,6 +14,7 @@
# limitations under the License. # limitations under the License.
import logging import logging
from typing import Dict, Tuple
from six import itervalues from six import itervalues
@ -25,13 +26,7 @@ from twisted.internet import defer
import synapse.logging.opentracing as opentracing import synapse.logging.opentracing as opentracing
import synapse.types import synapse.types
from synapse import event_auth from synapse import event_auth
from synapse.api.constants import ( from synapse.api.constants import EventTypes, LimitBlockingTypes, Membership, UserTypes
EventTypes,
JoinRules,
LimitBlockingTypes,
Membership,
UserTypes,
)
from synapse.api.errors import ( from synapse.api.errors import (
AuthError, AuthError,
Codes, Codes,
@ -513,71 +508,43 @@ class Auth(object):
""" """
return self.store.is_server_admin(user) return self.store.is_server_admin(user)
@defer.inlineCallbacks def compute_auth_events(
def compute_auth_events(self, event, current_state_ids, for_verification=False): self,
event,
current_state_ids: Dict[Tuple[str, str], str],
for_verification: bool = False,
):
"""Given an event and current state return the list of event IDs used
to auth an event.
If `for_verification` is False then only return auth events that
should be added to the event's `auth_events`.
Returns:
defer.Deferred(list[str]): List of event IDs.
"""
if event.type == EventTypes.Create: if event.type == EventTypes.Create:
return [] return defer.succeed([])
# Currently we ignore the `for_verification` flag even though there are
# some situations where we can drop particular auth events when adding
# to the event's `auth_events` (e.g. joins pointing to previous joins
# when room is publically joinable). Dropping event IDs has the
# advantage that the auth chain for the room grows slower, but we use
# the auth chain in state resolution v2 to order events, which means
# care must be taken if dropping events to ensure that it doesn't
# introduce undesirable "state reset" behaviour.
#
# All of which sounds a bit tricky so we don't bother for now.
auth_ids = [] auth_ids = []
for etype, state_key in event_auth.auth_types_for_event(event):
auth_ev_id = current_state_ids.get((etype, state_key))
if auth_ev_id:
auth_ids.append(auth_ev_id)
key = (EventTypes.PowerLevels, "") return defer.succeed(auth_ids)
power_level_event_id = current_state_ids.get(key)
if power_level_event_id:
auth_ids.append(power_level_event_id)
key = (EventTypes.JoinRules, "")
join_rule_event_id = current_state_ids.get(key)
key = (EventTypes.Member, event.sender)
member_event_id = current_state_ids.get(key)
key = (EventTypes.Create, "")
create_event_id = current_state_ids.get(key)
if create_event_id:
auth_ids.append(create_event_id)
if join_rule_event_id:
join_rule_event = yield self.store.get_event(join_rule_event_id)
join_rule = join_rule_event.content.get("join_rule")
is_public = join_rule == JoinRules.PUBLIC if join_rule else False
else:
is_public = False
if event.type == EventTypes.Member:
e_type = event.content["membership"]
if e_type in [Membership.JOIN, Membership.INVITE]:
if join_rule_event_id:
auth_ids.append(join_rule_event_id)
if e_type == Membership.JOIN:
if member_event_id and not is_public:
auth_ids.append(member_event_id)
else:
if member_event_id:
auth_ids.append(member_event_id)
if for_verification:
key = (EventTypes.Member, event.state_key)
existing_event_id = current_state_ids.get(key)
if existing_event_id:
auth_ids.append(existing_event_id)
if e_type == Membership.INVITE:
if "third_party_invite" in event.content:
key = (
EventTypes.ThirdPartyInvite,
event.content["third_party_invite"]["signed"]["token"],
)
third_party_invite_id = current_state_ids.get(key)
if third_party_invite_id:
auth_ids.append(third_party_invite_id)
elif member_event_id:
member_event = yield self.store.get_event(member_event_id)
if member_event.content["membership"] == Membership.JOIN:
auth_ids.append(member_event.event_id)
return auth_ids
@defer.inlineCallbacks @defer.inlineCallbacks
def check_can_change_room_list(self, room_id, user): def check_can_change_room_list(self, room_id, user):