forked-synapse/synapse/config/room_directory.py
Patrick Cloke 7ae559944a
Fix checking whether a room can be published on creation. (#11392)
If `room_list_publication_rules` was configured with a rule with a
non-wildcard alias and a room was created with an alias then an
internal server error would have been thrown.

This fixes the error and properly applies the publication rules
during room creation.
2021-11-19 15:19:32 +00:00

227 lines
7.9 KiB
Python

# Copyright 2018 New Vector Ltd
# Copyright 2021 Matrix.org Foundation C.I.C.
#
# 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.
from typing import List
from synapse.types import JsonDict
from synapse.util import glob_to_regex
from ._base import Config, ConfigError
class RoomDirectoryConfig(Config):
section = "roomdirectory"
def read_config(self, config, **kwargs) -> None:
self.enable_room_list_search = config.get("enable_room_list_search", True)
alias_creation_rules = config.get("alias_creation_rules")
if alias_creation_rules is not None:
self._alias_creation_rules = [
_RoomDirectoryRule("alias_creation_rules", rule)
for rule in alias_creation_rules
]
else:
self._alias_creation_rules = [
_RoomDirectoryRule("alias_creation_rules", {"action": "allow"})
]
room_list_publication_rules = config.get("room_list_publication_rules")
if room_list_publication_rules is not None:
self._room_list_publication_rules = [
_RoomDirectoryRule("room_list_publication_rules", rule)
for rule in room_list_publication_rules
]
else:
self._room_list_publication_rules = [
_RoomDirectoryRule("room_list_publication_rules", {"action": "allow"})
]
def generate_config_section(self, config_dir_path, server_name, **kwargs) -> str:
return """
# Uncomment to disable searching the public room list. When disabled
# blocks searching local and remote room lists for local and remote
# users by always returning an empty list for all queries.
#
#enable_room_list_search: false
# The `alias_creation` option controls who's allowed to create aliases
# on this server.
#
# The format of this option is a list of rules that contain globs that
# match against user_id, room_id and the new alias (fully qualified with
# server name). The action in the first rule that matches is taken,
# which can currently either be "allow" or "deny".
#
# Missing user_id/room_id/alias fields default to "*".
#
# If no rules match the request is denied. An empty list means no one
# can create aliases.
#
# Options for the rules include:
#
# user_id: Matches against the creator of the alias
# alias: Matches against the alias being created
# room_id: Matches against the room ID the alias is being pointed at
# action: Whether to "allow" or "deny" the request if the rule matches
#
# The default is:
#
#alias_creation_rules:
# - user_id: "*"
# alias: "*"
# room_id: "*"
# action: allow
# The `room_list_publication_rules` option controls who can publish and
# which rooms can be published in the public room list.
#
# The format of this option is the same as that for
# `alias_creation_rules`.
#
# If the room has one or more aliases associated with it, only one of
# the aliases needs to match the alias rule. If there are no aliases
# then only rules with `alias: *` match.
#
# If no rules match the request is denied. An empty list means no one
# can publish rooms.
#
# Options for the rules include:
#
# user_id: Matches against the creator of the alias
# room_id: Matches against the room ID being published
# alias: Matches against any current local or canonical aliases
# associated with the room
# action: Whether to "allow" or "deny" the request if the rule matches
#
# The default is:
#
#room_list_publication_rules:
# - user_id: "*"
# alias: "*"
# room_id: "*"
# action: allow
"""
def is_alias_creation_allowed(self, user_id: str, room_id: str, alias: str) -> bool:
"""Checks if the given user is allowed to create the given alias
Args:
user_id: The user to check.
room_id: The room ID for the alias.
alias: The alias being created.
Returns:
True if user is allowed to create the alias
"""
for rule in self._alias_creation_rules:
if rule.matches(user_id, room_id, [alias]):
return rule.action == "allow"
return False
def is_publishing_room_allowed(
self, user_id: str, room_id: str, aliases: List[str]
) -> bool:
"""Checks if the given user is allowed to publish the room
Args:
user_id: The user ID publishing the room.
room_id: The room being published.
aliases: any local aliases associated with the room
Returns:
True if user can publish room
"""
for rule in self._room_list_publication_rules:
if rule.matches(user_id, room_id, aliases):
return rule.action == "allow"
return False
class _RoomDirectoryRule:
"""Helper class to test whether a room directory action is allowed, like
creating an alias or publishing a room.
"""
def __init__(self, option_name: str, rule: JsonDict):
"""
Args:
option_name: Name of the config option this rule belongs to
rule: The rule as specified in the config
"""
action = rule["action"]
user_id = rule.get("user_id", "*")
room_id = rule.get("room_id", "*")
alias = rule.get("alias", "*")
if action in ("allow", "deny"):
self.action = action
else:
raise ConfigError(
"%s rules can only have action of 'allow' or 'deny'" % (option_name,)
)
self._alias_matches_all = alias == "*"
try:
self._user_id_regex = glob_to_regex(user_id)
self._alias_regex = glob_to_regex(alias)
self._room_id_regex = glob_to_regex(room_id)
except Exception as e:
raise ConfigError("Failed to parse glob into regex") from e
def matches(self, user_id: str, room_id: str, aliases: List[str]) -> bool:
"""Tests if this rule matches the given user_id, room_id and aliases.
Args:
user_id: The user ID to check.
room_id: The room ID to check.
aliases: The associated aliases to the room. Will be a single element
for testing alias creation, and can be empty for testing room
publishing.
Returns:
True if the rule matches.
"""
# Note: The regexes are anchored at both ends
if not self._user_id_regex.match(user_id):
return False
if not self._room_id_regex.match(room_id):
return False
# We only have alias checks left, so we can short circuit if the alias
# rule matches everything.
if self._alias_matches_all:
return True
# If we are not given any aliases then this rule only matches if the
# alias glob matches all aliases, which we checked above.
if not aliases:
return False
# Otherwise, we just need one alias to match
for alias in aliases:
if self._alias_regex.match(alias):
return True
return False