From 96358cb42410a4be6268eaa3ffec229c550208ea Mon Sep 17 00:00:00 2001 From: Patrick Cloke Date: Fri, 4 Dec 2020 10:56:28 -0500 Subject: [PATCH] Add authentication to replication endpoints. (#8853) Authentication is done by checking a shared secret provided in the Synapse configuration file. --- changelog.d/8853.feature | 1 + docs/sample_config.yaml | 7 ++ docs/workers.md | 6 +- synapse/config/workers.py | 10 ++ synapse/replication/http/_base.py | 47 ++++++- tests/replication/test_auth.py | 119 ++++++++++++++++++ tests/replication/test_client_reader_shard.py | 9 +- 7 files changed, 184 insertions(+), 15 deletions(-) create mode 100644 changelog.d/8853.feature create mode 100644 tests/replication/test_auth.py diff --git a/changelog.d/8853.feature b/changelog.d/8853.feature new file mode 100644 index 000000000..63c59f4ff --- /dev/null +++ b/changelog.d/8853.feature @@ -0,0 +1 @@ +Add optional HTTP authentication to replication endpoints. diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml index 6dbccf593..8712c580c 100644 --- a/docs/sample_config.yaml +++ b/docs/sample_config.yaml @@ -2589,6 +2589,13 @@ opentracing: # #run_background_tasks_on: worker1 +# A shared secret used by the replication APIs to authenticate HTTP requests +# from workers. +# +# By default this is unused and traffic is not authenticated. +# +#worker_replication_secret: "" + # Configuration for Redis when using workers. This *must* be enabled when # using workers (unless using old style direct TCP configuration). diff --git a/docs/workers.md b/docs/workers.md index c53d1bd2f..efe97af31 100644 --- a/docs/workers.md +++ b/docs/workers.md @@ -89,7 +89,8 @@ shared configuration file. Normally, only a couple of changes are needed to make an existing configuration file suitable for use with workers. First, you need to enable an "HTTP replication listener" for the main process; and secondly, you need to enable redis-based -replication. For example: +replication. Optionally, a shared secret can be used to authenticate HTTP +traffic between workers. For example: ```yaml @@ -103,6 +104,9 @@ listeners: resources: - names: [replication] +# Add a random shared secret to authenticate traffic. +worker_replication_secret: "" + redis: enabled: true ``` diff --git a/synapse/config/workers.py b/synapse/config/workers.py index 57ab097eb..7ca9efec5 100644 --- a/synapse/config/workers.py +++ b/synapse/config/workers.py @@ -85,6 +85,9 @@ class WorkerConfig(Config): # The port on the main synapse for HTTP replication endpoint self.worker_replication_http_port = config.get("worker_replication_http_port") + # The shared secret used for authentication when connecting to the main synapse. + self.worker_replication_secret = config.get("worker_replication_secret", None) + self.worker_name = config.get("worker_name", self.worker_app) self.worker_main_http_uri = config.get("worker_main_http_uri", None) @@ -185,6 +188,13 @@ class WorkerConfig(Config): # data). If not provided this defaults to the main process. # #run_background_tasks_on: worker1 + + # A shared secret used by the replication APIs to authenticate HTTP requests + # from workers. + # + # By default this is unused and traffic is not authenticated. + # + #worker_replication_secret: "" """ def read_arguments(self, args): diff --git a/synapse/replication/http/_base.py b/synapse/replication/http/_base.py index 2b3972cb1..1492ac922 100644 --- a/synapse/replication/http/_base.py +++ b/synapse/replication/http/_base.py @@ -106,6 +106,25 @@ class ReplicationEndpoint(metaclass=abc.ABCMeta): assert self.METHOD in ("PUT", "POST", "GET") + self._replication_secret = None + if hs.config.worker.worker_replication_secret: + self._replication_secret = hs.config.worker.worker_replication_secret + + def _check_auth(self, request) -> None: + # Get the authorization header. + auth_headers = request.requestHeaders.getRawHeaders(b"Authorization") + + if len(auth_headers) > 1: + raise RuntimeError("Too many Authorization headers.") + parts = auth_headers[0].split(b" ") + if parts[0] == b"Bearer" and len(parts) == 2: + received_secret = parts[1].decode("ascii") + if self._replication_secret == received_secret: + # Success! + return + + raise RuntimeError("Invalid Authorization header.") + @abc.abstractmethod async def _serialize_payload(**kwargs): """Static method that is called when creating a request. @@ -150,6 +169,12 @@ class ReplicationEndpoint(metaclass=abc.ABCMeta): outgoing_gauge = _pending_outgoing_requests.labels(cls.NAME) + replication_secret = None + if hs.config.worker.worker_replication_secret: + replication_secret = hs.config.worker.worker_replication_secret.encode( + "ascii" + ) + @trace(opname="outgoing_replication_request") @outgoing_gauge.track_inprogress() async def send_request(instance_name="master", **kwargs): @@ -202,6 +227,9 @@ class ReplicationEndpoint(metaclass=abc.ABCMeta): # the master, and so whether we should clean up or not. while True: headers = {} # type: Dict[bytes, List[bytes]] + # Add an authorization header, if configured. + if replication_secret: + headers[b"Authorization"] = [b"Bearer " + replication_secret] inject_active_span_byte_dict(headers, None, check_destination=False) try: result = await request_func(uri, data, headers=headers) @@ -236,21 +264,19 @@ class ReplicationEndpoint(metaclass=abc.ABCMeta): """ url_args = list(self.PATH_ARGS) - handler = self._handle_request method = self.METHOD if self.CACHE: - handler = self._cached_handler # type: ignore url_args.append("txn_id") args = "/".join("(?P<%s>[^/]+)" % (arg,) for arg in url_args) pattern = re.compile("^/_synapse/replication/%s/%s$" % (self.NAME, args)) http_server.register_paths( - method, [pattern], handler, self.__class__.__name__, + method, [pattern], self._check_auth_and_handle, self.__class__.__name__, ) - def _cached_handler(self, request, txn_id, **kwargs): + def _check_auth_and_handle(self, request, **kwargs): """Called on new incoming requests when caching is enabled. Checks if there is a cached response for the request and returns that, otherwise calls `_handle_request` and caches its response. @@ -258,6 +284,15 @@ class ReplicationEndpoint(metaclass=abc.ABCMeta): # We just use the txn_id here, but we probably also want to use the # other PATH_ARGS as well. - assert self.CACHE + # Check the authorization headers before handling the request. + if self._replication_secret: + self._check_auth(request) - return self.response_cache.wrap(txn_id, self._handle_request, request, **kwargs) + if self.CACHE: + txn_id = kwargs.pop("txn_id") + + return self.response_cache.wrap( + txn_id, self._handle_request, request, **kwargs + ) + + return self._handle_request(request, **kwargs) diff --git a/tests/replication/test_auth.py b/tests/replication/test_auth.py new file mode 100644 index 000000000..fe9e4d5f9 --- /dev/null +++ b/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") diff --git a/tests/replication/test_client_reader_shard.py b/tests/replication/test_client_reader_shard.py index 96801db47..fdaad3d8a 100644 --- a/tests/replication/test_client_reader_shard.py +++ b/tests/replication/test_client_reader_shard.py @@ -14,27 +14,20 @@ # limitations under the License. import logging -from synapse.api.constants import LoginType from synapse.http.site import SynapseRequest from synapse.rest.client.v2_alpha import register from tests.replication._base import BaseMultiWorkerStreamTestCase -from tests.rest.client.v2_alpha.test_auth import DummyRecaptchaChecker from tests.server import FakeChannel, make_request logger = logging.getLogger(__name__) class ClientReaderTestCase(BaseMultiWorkerStreamTestCase): - """Base class for tests of the replication streams""" + """Test using one or more client readers for registration.""" servlets = [register.register_servlets] - def prepare(self, reactor, clock, hs): - self.recaptcha_checker = DummyRecaptchaChecker(hs) - auth_handler = hs.get_auth_handler() - auth_handler.checkers[LoginType.RECAPTCHA] = self.recaptcha_checker - def _get_worker_hs_config(self) -> dict: config = self.default_config() config["worker_app"] = "synapse.app.client_reader"