diff --git a/changelog.d/4051.feature b/changelog.d/4051.feature new file mode 100644 index 000000000..9c1b3a72a --- /dev/null +++ b/changelog.d/4051.feature @@ -0,0 +1 @@ +Add config option to control alias creation diff --git a/synapse/config/homeserver.py b/synapse/config/homeserver.py index b8d5690f2..10dd40159 100644 --- a/synapse/config/homeserver.py +++ b/synapse/config/homeserver.py @@ -31,6 +31,7 @@ from .push import PushConfig from .ratelimiting import RatelimitConfig from .registration import RegistrationConfig from .repository import ContentRepositoryConfig +from .room_directory import RoomDirectoryConfig from .saml2 import SAML2Config from .server import ServerConfig from .server_notices_config import ServerNoticesConfig @@ -49,7 +50,7 @@ class HomeServerConfig(TlsConfig, ServerConfig, DatabaseConfig, LoggingConfig, WorkerConfig, PasswordAuthProviderConfig, PushConfig, SpamCheckerConfig, GroupsConfig, UserDirectoryConfig, ConsentConfig, - ServerNoticesConfig, + ServerNoticesConfig, RoomDirectoryConfig, ): pass diff --git a/synapse/config/room_directory.py b/synapse/config/room_directory.py new file mode 100644 index 000000000..9da13ab11 --- /dev/null +++ b/synapse/config/room_directory.py @@ -0,0 +1,102 @@ +# -*- coding: utf-8 -*- +# Copyright 2018 New Vector 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. + +from synapse.util import glob_to_regex + +from ._base import Config, ConfigError + + +class RoomDirectoryConfig(Config): + def read_config(self, config): + alias_creation_rules = config["alias_creation_rules"] + + self._alias_creation_rules = [ + _AliasRule(rule) + for rule in alias_creation_rules + ] + + def default_config(self, config_dir_path, server_name, **kwargs): + return """ + # 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 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". + # + # If no rules match the request is denied. + alias_creation_rules: + - user_id: "*" + alias: "*" + action: allow + """ + + def is_alias_creation_allowed(self, user_id, alias): + """Checks if the given user is allowed to create the given alias + + Args: + user_id (str) + alias (str) + + Returns: + boolean: True if user is allowed to crate the alias + """ + for rule in self._alias_creation_rules: + if rule.matches(user_id, alias): + return rule.action == "allow" + + return False + + +class _AliasRule(object): + def __init__(self, rule): + action = rule["action"] + user_id = rule["user_id"] + alias = rule["alias"] + + if action in ("allow", "deny"): + self.action = action + else: + raise ConfigError( + "alias_creation_rules rules can only have action of 'allow'" + " or 'deny'" + ) + + try: + self._user_id_regex = glob_to_regex(user_id) + self._alias_regex = glob_to_regex(alias) + except Exception as e: + raise ConfigError("Failed to parse glob into regex: %s", e) + + def matches(self, user_id, alias): + """Tests if this rule matches the given user_id and alias. + + Args: + user_id (str) + alias (str) + + Returns: + boolean + """ + + # Note: The regexes are anchored at both ends + if not self._user_id_regex.match(user_id): + return False + + if not self._alias_regex.match(alias): + return False + + return True diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py index af0107a46..0f9302a6a 100644 --- a/synapse/federation/federation_server.py +++ b/synapse/federation/federation_server.py @@ -14,7 +14,6 @@ # See the License for the specific language governing permissions and # limitations under the License. import logging -import re import six from six import iteritems @@ -44,6 +43,7 @@ from synapse.replication.http.federation import ( ReplicationGetQueryRestServlet, ) from synapse.types import get_domain_from_id +from synapse.util import glob_to_regex from synapse.util.async_helpers import Linearizer, concurrently_execute from synapse.util.caches.response_cache import ResponseCache from synapse.util.logcontext import nested_logging_context @@ -729,22 +729,10 @@ def _acl_entry_matches(server_name, acl_entry): if not isinstance(acl_entry, six.string_types): logger.warn("Ignoring non-str ACL entry '%s' (is %s)", acl_entry, type(acl_entry)) return False - regex = _glob_to_regex(acl_entry) + regex = glob_to_regex(acl_entry) return regex.match(server_name) -def _glob_to_regex(glob): - res = '' - for c in glob: - if c == '*': - res = res + '.*' - elif c == '?': - res = res + '.' - else: - res = res + re.escape(c) - return re.compile(res + "\\Z", re.IGNORECASE) - - class FederationHandlerRegistry(object): """Allows classes to register themselves as handlers for a given EDU or query type for incoming federation traffic. diff --git a/synapse/handlers/directory.py b/synapse/handlers/directory.py index 02f12f664..7d67bf803 100644 --- a/synapse/handlers/directory.py +++ b/synapse/handlers/directory.py @@ -43,6 +43,7 @@ class DirectoryHandler(BaseHandler): self.state = hs.get_state_handler() self.appservice_handler = hs.get_application_service_handler() self.event_creation_handler = hs.get_event_creation_handler() + self.config = hs.config self.federation = hs.get_federation_client() hs.get_federation_registry().register_query_handler( @@ -111,6 +112,14 @@ class DirectoryHandler(BaseHandler): 403, "This user is not permitted to create this alias", ) + if not self.config.is_alias_creation_allowed(user_id, room_alias.to_string()): + # Lets just return a generic message, as there may be all sorts of + # reasons why we said no. TODO: Allow configurable error messages + # per alias creation rule? + raise SynapseError( + 403, "Not allowed to create alias", + ) + can_create = yield self.can_modify_alias( room_alias, user_id=user_id diff --git a/synapse/util/__init__.py b/synapse/util/__init__.py index 9a8fae049..0ae7e2ef3 100644 --- a/synapse/util/__init__.py +++ b/synapse/util/__init__.py @@ -14,6 +14,7 @@ # limitations under the License. import logging +import re from itertools import islice import attr @@ -138,3 +139,27 @@ def log_failure(failure, msg, consumeErrors=True): if not consumeErrors: return failure + + +def glob_to_regex(glob): + """Converts a glob to a compiled regex object. + + The regex is anchored at the beginning and end of the string. + + Args: + glob (str) + + Returns: + re.RegexObject + """ + res = '' + for c in glob: + if c == '*': + res = res + '.*' + elif c == '?': + res = res + '.' + else: + res = res + re.escape(c) + + # \A anchors at start of string, \Z at end of string + return re.compile(r"\A" + res + r"\Z", re.IGNORECASE) diff --git a/tests/config/test_room_directory.py b/tests/config/test_room_directory.py new file mode 100644 index 000000000..f37a17d61 --- /dev/null +++ b/tests/config/test_room_directory.py @@ -0,0 +1,67 @@ +# -*- coding: utf-8 -*- +# Copyright 2018 New Vector 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 yaml + +from synapse.config.room_directory import RoomDirectoryConfig + +from tests import unittest + + +class RoomDirectoryConfigTestCase(unittest.TestCase): + def test_alias_creation_acl(self): + config = yaml.load(""" + alias_creation_rules: + - user_id: "*bob*" + alias: "*" + action: "deny" + - user_id: "*" + alias: "#unofficial_*" + action: "allow" + - user_id: "@foo*:example.com" + alias: "*" + action: "allow" + - user_id: "@gah:example.com" + alias: "#goo:example.com" + action: "allow" + """) + + rd_config = RoomDirectoryConfig() + rd_config.read_config(config) + + self.assertFalse(rd_config.is_alias_creation_allowed( + user_id="@bob:example.com", + alias="#test:example.com", + )) + + self.assertTrue(rd_config.is_alias_creation_allowed( + user_id="@test:example.com", + alias="#unofficial_st:example.com", + )) + + self.assertTrue(rd_config.is_alias_creation_allowed( + user_id="@foobar:example.com", + alias="#test:example.com", + )) + + self.assertTrue(rd_config.is_alias_creation_allowed( + user_id="@gah:example.com", + alias="#goo:example.com", + )) + + self.assertFalse(rd_config.is_alias_creation_allowed( + user_id="@test:example.com", + alias="#test:example.com", + )) diff --git a/tests/handlers/test_directory.py b/tests/handlers/test_directory.py index ec7355688..8ae6556c0 100644 --- a/tests/handlers/test_directory.py +++ b/tests/handlers/test_directory.py @@ -18,7 +18,9 @@ from mock import Mock from twisted.internet import defer +from synapse.config.room_directory import RoomDirectoryConfig from synapse.handlers.directory import DirectoryHandler +from synapse.rest.client.v1 import directory, room from synapse.types import RoomAlias from tests import unittest @@ -102,3 +104,49 @@ class DirectoryTestCase(unittest.TestCase): ) self.assertEquals({"room_id": "!8765asdf:test", "servers": ["test"]}, response) + + +class TestCreateAliasACL(unittest.HomeserverTestCase): + user_id = "@test:test" + + servlets = [directory.register_servlets, room.register_servlets] + + def prepare(self, hs, reactor, clock): + # We cheekily override the config to add custom alias creation rules + config = {} + config["alias_creation_rules"] = [ + { + "user_id": "*", + "alias": "#unofficial_*", + "action": "allow", + } + ] + + rd_config = RoomDirectoryConfig() + rd_config.read_config(config) + + self.hs.config.is_alias_creation_allowed = rd_config.is_alias_creation_allowed + + return hs + + def test_denied(self): + room_id = self.helper.create_room_as(self.user_id) + + request, channel = self.make_request( + "PUT", + b"directory/room/%23test%3Atest", + ('{"room_id":"%s"}' % (room_id,)).encode('ascii'), + ) + self.render(request) + self.assertEquals(403, channel.code, channel.result) + + def test_allowed(self): + room_id = self.helper.create_room_as(self.user_id) + + request, channel = self.make_request( + "PUT", + b"directory/room/%23unofficial_test%3Atest", + ('{"room_id":"%s"}' % (room_id,)).encode('ascii'), + ) + self.render(request) + self.assertEquals(200, channel.code, channel.result)