forked-synapse/synapse/push/presentable_names.py
Patrick Cloke 6f7417c3db
Handle missing content keys when calculating presentable names. (#9165)
Treat the content as untrusted and do not assume it is of
the proper form.
2021-01-25 07:27:16 -05:00

211 lines
7.6 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2016 OpenMarket 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
import re
from typing import TYPE_CHECKING, Dict, Iterable, Optional
from synapse.api.constants import EventTypes, Membership
from synapse.events import EventBase
from synapse.types import StateMap
if TYPE_CHECKING:
from synapse.storage.databases.main import DataStore
logger = logging.getLogger(__name__)
# intentionally looser than what aliases we allow to be registered since
# other HSes may allow aliases that we would not
ALIAS_RE = re.compile(r"^#.*:.+$")
ALL_ALONE = "Empty Room"
async def calculate_room_name(
store: "DataStore",
room_state_ids: StateMap[str],
user_id: str,
fallback_to_members: bool = True,
fallback_to_single_member: bool = True,
) -> Optional[str]:
"""
Works out a user-facing name for the given room as per Matrix
spec recommendations.
Does not yet support internationalisation.
Args:
store: The data store to query.
room_state_ids: Dictionary of the room's state IDs.
user_id: The ID of the user to whom the room name is being presented
fallback_to_members: If False, return None instead of generating a name
based on the room's members if the room has no
title or aliases.
fallback_to_single_member: If False, return None instead of generating a
name based on the user who invited this user to the room if the room
has no title or aliases.
Returns:
A human readable name for the room, if possible.
"""
# does it have a name?
if (EventTypes.Name, "") in room_state_ids:
m_room_name = await store.get_event(
room_state_ids[(EventTypes.Name, "")], allow_none=True
)
if m_room_name and m_room_name.content and m_room_name.content.get("name"):
return m_room_name.content["name"]
# does it have a canonical alias?
if (EventTypes.CanonicalAlias, "") in room_state_ids:
canon_alias = await store.get_event(
room_state_ids[(EventTypes.CanonicalAlias, "")], allow_none=True
)
if (
canon_alias
and canon_alias.content
and canon_alias.content.get("alias")
and _looks_like_an_alias(canon_alias.content["alias"])
):
return canon_alias.content["alias"]
if not fallback_to_members:
return None
my_member_event = None
if (EventTypes.Member, user_id) in room_state_ids:
my_member_event = await store.get_event(
room_state_ids[(EventTypes.Member, user_id)], allow_none=True
)
if (
my_member_event is not None
and my_member_event.content.get("membership") == Membership.INVITE
):
if (EventTypes.Member, my_member_event.sender) in room_state_ids:
inviter_member_event = await store.get_event(
room_state_ids[(EventTypes.Member, my_member_event.sender)],
allow_none=True,
)
if inviter_member_event:
if fallback_to_single_member:
return "Invite from %s" % (
name_from_member_event(inviter_member_event),
)
else:
return None
else:
return "Room Invite"
# at this point we're going to need to search the state by all state keys
# for an event type, so rearrange the data structure
room_state_bytype_ids = _state_as_two_level_dict(room_state_ids)
# we're going to have to generate a name based on who's in the room,
# so find out who is in the room that isn't the user.
if EventTypes.Member in room_state_bytype_ids:
member_events = await store.get_events(
list(room_state_bytype_ids[EventTypes.Member].values())
)
all_members = [
ev
for ev in member_events.values()
if ev.content.get("membership") == Membership.JOIN
or ev.content.get("membership") == Membership.INVITE
]
# Sort the member events oldest-first so the we name people in the
# order the joined (it should at least be deterministic rather than
# dictionary iteration order)
all_members.sort(key=lambda e: e.origin_server_ts)
other_members = [m for m in all_members if m.state_key != user_id]
else:
other_members = []
all_members = []
if len(other_members) == 0:
if len(all_members) == 1:
# self-chat, peeked room with 1 participant,
# or inbound invite, or outbound 3PID invite.
if all_members[0].sender == user_id:
if EventTypes.ThirdPartyInvite in room_state_bytype_ids:
third_party_invites = room_state_bytype_ids[
EventTypes.ThirdPartyInvite
].values()
if len(third_party_invites) > 0:
# technically third party invite events are not member
# events, but they are close enough
# FIXME: no they're not - they look nothing like a member;
# they have a great big encrypted thing as their name to
# prevent leaking the 3PID name...
# return "Inviting %s" % (
# descriptor_from_member_events(third_party_invites)
# )
return "Inviting email address"
else:
return ALL_ALONE
else:
return name_from_member_event(all_members[0])
else:
return ALL_ALONE
elif len(other_members) == 1 and not fallback_to_single_member:
return None
return descriptor_from_member_events(other_members)
def descriptor_from_member_events(member_events: Iterable[EventBase]) -> str:
"""Get a description of the room based on the member events.
Args:
member_events: The events of a room.
Returns:
The room description
"""
member_events = list(member_events)
if len(member_events) == 0:
return "nobody"
elif len(member_events) == 1:
return name_from_member_event(member_events[0])
elif len(member_events) == 2:
return "%s and %s" % (
name_from_member_event(member_events[0]),
name_from_member_event(member_events[1]),
)
else:
return "%s and %d others" % (
name_from_member_event(member_events[0]),
len(member_events) - 1,
)
def name_from_member_event(member_event: EventBase) -> str:
if member_event.content and member_event.content.get("displayname"):
return member_event.content["displayname"]
return member_event.state_key
def _state_as_two_level_dict(state: StateMap[str]) -> Dict[str, Dict[str, str]]:
ret = {} # type: Dict[str, Dict[str, str]]
for k, v in state.items():
ret.setdefault(k[0], {})[k[1]] = v
return ret
def _looks_like_an_alias(string: str) -> bool:
return ALIAS_RE.match(string) is not None