Do checks on aliases for incoming m.room.aliases events (#5128)

Follow-up to #5124

Also added a bunch of checks to make sure everything (both the stuff added on #5124 and this PR) works as intended.

tests/rest/client/v1/test_directory.py

@@ -0,0 +1,169 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 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 json
+
+from synapse.rest.admin import register_servlets
+from synapse.rest.client.v1 import directory, login, room
+from synapse.types import RoomAlias
+from synapse.util.stringutils import random_string
+
+from tests import unittest
+
+
+class DirectoryTestCase(unittest.HomeserverTestCase):
+
+    servlets = [
+        register_servlets,
+        directory.register_servlets,
+        login.register_servlets,
+        room.register_servlets,
+    ]
+
+    def make_homeserver(self, reactor, clock):
+        config = self.default_config()
+        config.require_membership_for_aliases = True
+
+        self.hs = self.setup_test_homeserver(config=config)
+
+        return self.hs
+
+    def prepare(self, reactor, clock, homeserver):
+        self.room_owner = self.register_user("room_owner", "test")
+        self.room_owner_tok = self.login("room_owner", "test")
+
+        self.room_id = self.helper.create_room_as(
+            self.room_owner, tok=self.room_owner_tok,
+        )
+
+        self.user = self.register_user("user", "test")
+        self.user_tok = self.login("user", "test")
+
+    def test_state_event_not_in_room(self):
+        self.ensure_user_left_room()
+        self.set_alias_via_state_event(403)
+
+    def test_directory_endpoint_not_in_room(self):
+        self.ensure_user_left_room()
+        self.set_alias_via_directory(403)
+
+    def test_state_event_in_room_too_long(self):
+        self.ensure_user_joined_room()
+        self.set_alias_via_state_event(400, alias_length=256)
+
+    def test_directory_in_room_too_long(self):
+        self.ensure_user_joined_room()
+        self.set_alias_via_directory(400, alias_length=256)
+
+    def test_state_event_in_room(self):
+        self.ensure_user_joined_room()
+        self.set_alias_via_state_event(200)
+
+    def test_directory_in_room(self):
+        self.ensure_user_joined_room()
+        self.set_alias_via_directory(200)
+
+    def test_room_creation_too_long(self):
+        url = "/_matrix/client/r0/createRoom"
+
+        # We use deliberately a localpart under the length threshold so
+        # that we can make sure that the check is done on the whole alias.
+        data = {
+            "room_alias_name": random_string(256 - len(self.hs.hostname)),
+        }
+        request_data = json.dumps(data)
+        request, channel = self.make_request(
+            "POST", url, request_data, access_token=self.user_tok,
+        )
+        self.render(request)
+        self.assertEqual(channel.code, 400, channel.result)
+
+    def test_room_creation(self):
+        url = "/_matrix/client/r0/createRoom"
+
+        # Check with an alias of allowed length. There should already be
+        # a test that ensures it works in test_register.py, but let's be
+        # as cautious as possible here.
+        data = {
+            "room_alias_name": random_string(5),
+        }
+        request_data = json.dumps(data)
+        request, channel = self.make_request(
+            "POST", url, request_data, access_token=self.user_tok,
+        )
+        self.render(request)
+        self.assertEqual(channel.code, 200, channel.result)
+
+    def set_alias_via_state_event(self, expected_code, alias_length=5):
+        url = ("/_matrix/client/r0/rooms/%s/state/m.room.aliases/%s"
+               % (self.room_id, self.hs.hostname))
+
+        data = {
+            "aliases": [
+                self.random_alias(alias_length),
+            ],
+        }
+        request_data = json.dumps(data)
+
+        request, channel = self.make_request(
+            "PUT", url, request_data, access_token=self.user_tok,
+        )
+        self.render(request)
+        self.assertEqual(channel.code, expected_code, channel.result)
+
+    def set_alias_via_directory(self, expected_code, alias_length=5):
+        url = "/_matrix/client/r0/directory/room/%s" % self.random_alias(alias_length)
+        data = {
+            "room_id": self.room_id,
+        }
+        request_data = json.dumps(data)
+
+        request, channel = self.make_request(
+            "PUT", url, request_data, access_token=self.user_tok,
+        )
+        self.render(request)
+        self.assertEqual(channel.code, expected_code, channel.result)
+
+    def random_alias(self, length):
+        return RoomAlias(
+            random_string(length),
+            self.hs.hostname,
+        ).to_string()
+
+    def ensure_user_left_room(self):
+        self.ensure_membership("leave")
+
+    def ensure_user_joined_room(self):
+        self.ensure_membership("join")
+
+    def ensure_membership(self, membership):
+        try:
+            if membership == "leave":
+                self.helper.leave(
+                    room=self.room_id,
+                    user=self.user,
+                    tok=self.user_tok,
+                )
+            if membership == "join":
+                self.helper.join(
+                    room=self.room_id,
+                    user=self.user,
+                    tok=self.user_tok,
+                )
+        except AssertionError:
+            # We don't care whether the leave request didn't return a 200 (e.g.
+            # if the user isn't already in the room), because we only want to
+            # make sure the user isn't in the room.
+            pass