Refactor checking restricted join rules (#10007)

To be more consistent with similar code. The check now automatically
raises an AuthError instead of passing back a boolean. It also absorbs
some shared logic between callers.
This commit is contained in:
Patrick Cloke 2021-05-18 12:17:04 -04:00 committed by GitHub
parent 4d6e5a5e99
commit ac6bfcd52f
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
4 changed files with 49 additions and 50 deletions

View file

@ -0,0 +1 @@
Experimental support to allow a user who could join a restricted room to view it in the spaces summary.

View file

@ -11,10 +11,12 @@
# 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.
from typing import TYPE_CHECKING
from typing import TYPE_CHECKING, Optional
from synapse.api.constants import EventTypes, JoinRules
from synapse.api.constants import EventTypes, JoinRules, Membership
from synapse.api.errors import AuthError
from synapse.api.room_versions import RoomVersion
from synapse.events import EventBase
from synapse.types import StateMap
if TYPE_CHECKING:
@ -29,44 +31,58 @@ class EventAuthHandler:
def __init__(self, hs: "HomeServer"):
self._store = hs.get_datastore()
async def can_join_without_invite(
self, state_ids: StateMap[str], room_version: RoomVersion, user_id: str
) -> bool:
async def check_restricted_join_rules(
self,
state_ids: StateMap[str],
room_version: RoomVersion,
user_id: str,
prev_member_event: Optional[EventBase],
) -> None:
"""
Check whether a user can join a room without an invite.
Check whether a user can join a room without an invite due to restricted join rules.
When joining a room with restricted joined rules (as defined in MSC3083),
the membership of spaces must be checked during join.
the membership of spaces must be checked during a room join.
Args:
state_ids: The state of the room as it currently is.
room_version: The room version of the room being joined.
user_id: The user joining the room.
prev_member_event: The current membership event for this user.
Returns:
True if the user can join the room, false otherwise.
Raises:
AuthError if the user cannot join the room.
"""
# If the member is invited or currently joined, then nothing to do.
if prev_member_event and (
prev_member_event.membership in (Membership.JOIN, Membership.INVITE)
):
return
# This only applies to room versions which support the new join rule.
if not room_version.msc3083_join_rules:
return True
return
# If there's no join rule, then it defaults to invite (so this doesn't apply).
join_rules_event_id = state_ids.get((EventTypes.JoinRules, ""), None)
if not join_rules_event_id:
return True
return
# If the join rule is not restricted, this doesn't apply.
join_rules_event = await self._store.get_event(join_rules_event_id)
if join_rules_event.content.get("join_rule") != JoinRules.MSC3083_RESTRICTED:
return True
return
# If allowed is of the wrong form, then only allow invited users.
allowed_spaces = join_rules_event.content.get("allow", [])
if not isinstance(allowed_spaces, list):
return False
allowed_spaces = ()
# Get the list of joined rooms and see if there's an overlap.
joined_rooms = await self._store.get_rooms_for_user(user_id)
if allowed_spaces:
joined_rooms = await self._store.get_rooms_for_user(user_id)
else:
joined_rooms = ()
# Pull out the other room IDs, invalid data gets filtered.
for space in allowed_spaces:
@ -80,7 +96,10 @@ class EventAuthHandler:
# The user was joined to one of the spaces specified, they can join
# this room!
if space_id in joined_rooms:
return True
return
# The user was not in any of the required spaces.
return False
raise AuthError(
403,
"You do not belong to any of the required spaces to join this room.",
)

View file

@ -1668,28 +1668,17 @@ class FederationHandler(BaseHandler):
# Check if the user is already in the room or invited to the room.
user_id = event.state_key
prev_member_event_id = prev_state_ids.get((EventTypes.Member, user_id), None)
newly_joined = True
user_is_invited = False
prev_member_event = None
if prev_member_event_id:
prev_member_event = await self.store.get_event(prev_member_event_id)
newly_joined = prev_member_event.membership != Membership.JOIN
user_is_invited = prev_member_event.membership == Membership.INVITE
# If the member is not already in the room, and not invited, check if
# they should be allowed access via membership in a space.
if (
newly_joined
and not user_is_invited
and not await self._event_auth_handler.can_join_without_invite(
prev_state_ids,
event.room_version,
user_id,
)
):
raise AuthError(
403,
"You do not belong to any of the required spaces to join this room.",
)
# Check if the member should be allowed access via membership in a space.
await self._event_auth_handler.check_restricted_join_rules(
prev_state_ids,
event.room_version,
user_id,
prev_member_event,
)
# Persist the event.
await self._auth_and_persist_event(origin, event, context)

View file

@ -260,25 +260,15 @@ class RoomMemberHandler(metaclass=abc.ABCMeta):
if event.membership == Membership.JOIN:
newly_joined = True
user_is_invited = False
prev_member_event = None
if prev_member_event_id:
prev_member_event = await self.store.get_event(prev_member_event_id)
newly_joined = prev_member_event.membership != Membership.JOIN
user_is_invited = prev_member_event.membership == Membership.INVITE
# If the member is not already in the room and is not accepting an invite,
# check if they should be allowed access via membership in a space.
if (
newly_joined
and not user_is_invited
and not await self.event_auth_handler.can_join_without_invite(
prev_state_ids, event.room_version, user_id
)
):
raise AuthError(
403,
"You do not belong to any of the required spaces to join this room.",
)
# Check if the member should be allowed access via membership in a space.
await self.event_auth_handler.check_restricted_join_rules(
prev_state_ids, event.room_version, user_id, prev_member_event
)
# Only rate-limit if the user actually joined the room, otherwise we'll end
# up blocking profile updates.