Add authentication to replication endpoints. (#8853)

Authentication is done by checking a shared secret provided
in the Synapse configuration file.

tests/replication/test_auth.py

@@ -0,0 +1,119 @@
+# -*- coding: utf-8 -*-
+# Copyright 2020 The 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.
+import logging
+from typing import Tuple
+
+from synapse.http.site import SynapseRequest
+from synapse.rest.client.v2_alpha import register
+
+from tests.replication._base import BaseMultiWorkerStreamTestCase
+from tests.server import FakeChannel, make_request
+from tests.unittest import override_config
+
+logger = logging.getLogger(__name__)
+
+
+class WorkerAuthenticationTestCase(BaseMultiWorkerStreamTestCase):
+    """Test the authentication of HTTP calls between workers."""
+
+    servlets = [register.register_servlets]
+
+    def make_homeserver(self, reactor, clock):
+        config = self.default_config()
+        # This isn't a real configuration option but is used to provide the main
+        # homeserver and worker homeserver different options.
+        main_replication_secret = config.pop("main_replication_secret", None)
+        if main_replication_secret:
+            config["worker_replication_secret"] = main_replication_secret
+        return self.setup_test_homeserver(config=config)
+
+    def _get_worker_hs_config(self) -> dict:
+        config = self.default_config()
+        config["worker_app"] = "synapse.app.client_reader"
+        config["worker_replication_host"] = "testserv"
+        config["worker_replication_http_port"] = "8765"
+
+        return config
+
+    def _test_register(self) -> Tuple[SynapseRequest, FakeChannel]:
+        """Run the actual test:
+
+        1. Create a worker homeserver.
+        2. Start registration by providing a user/password.
+        3. Complete registration by providing dummy auth (this hits the main synapse).
+        4. Return the final request.
+
+        """
+        worker_hs = self.make_worker_hs("synapse.app.client_reader")
+        site = self._hs_to_site[worker_hs]
+
+        request_1, channel_1 = make_request(
+            self.reactor,
+            site,
+            "POST",
+            "register",
+            {"username": "user", "type": "m.login.password", "password": "bar"},
+        )  # type: SynapseRequest, FakeChannel
+        self.assertEqual(request_1.code, 401)
+
+        # Grab the session
+        session = channel_1.json_body["session"]
+
+        # also complete the dummy auth
+        return make_request(
+            self.reactor,
+            site,
+            "POST",
+            "register",
+            {"auth": {"session": session, "type": "m.login.dummy"}},
+        )
+
+    def test_no_auth(self):
+        """With no authentication the request should finish.
+        """
+        request, channel = self._test_register()
+        self.assertEqual(request.code, 200)
+
+        # We're given a registered user.
+        self.assertEqual(channel.json_body["user_id"], "@user:test")
+
+    @override_config({"main_replication_secret": "my-secret"})
+    def test_missing_auth(self):
+        """If the main process expects a secret that is not provided, an error results.
+        """
+        request, channel = self._test_register()
+        self.assertEqual(request.code, 500)
+
+    @override_config(
+        {
+            "main_replication_secret": "my-secret",
+            "worker_replication_secret": "wrong-secret",
+        }
+    )
+    def test_unauthorized(self):
+        """If the main process receives the wrong secret, an error results.
+        """
+        request, channel = self._test_register()
+        self.assertEqual(request.code, 500)
+
+    @override_config({"worker_replication_secret": "my-secret"})
+    def test_authorized(self):
+        """The request should finish when the worker provides the authentication header.
+        """
+        request, channel = self._test_register()
+        self.assertEqual(request.code, 200)
+
+        # We're given a registered user.
+        self.assertEqual(channel.json_body["user_id"], "@user:test")