From e385c8b4734b95c0738d6f4022d7bbb1621167db Mon Sep 17 00:00:00 2001 From: Marcus Date: Tue, 12 Jan 2021 18:20:30 +0100 Subject: [PATCH] Don't apply the IP range blacklist to proxy connections (#9084) It is expected that the proxy would be on a private IP address so the configured proxy should be connected to regardless of the IP range blacklist. --- changelog.d/9084.bugfix | 1 + synapse/http/client.py | 1 + synapse/http/proxyagent.py | 16 ++++- tests/http/test_proxyagent.py | 130 ++++++++++++++++++++++++++++++++++ 4 files changed, 145 insertions(+), 3 deletions(-) create mode 100644 changelog.d/9084.bugfix diff --git a/changelog.d/9084.bugfix b/changelog.d/9084.bugfix new file mode 100644 index 0000000000..415dd8b259 --- /dev/null +++ b/changelog.d/9084.bugfix @@ -0,0 +1 @@ +Don't blacklist connections to the configured proxy. Contributed by @Bubu. diff --git a/synapse/http/client.py b/synapse/http/client.py index 29f40ddf5f..5f74ee1149 100644 --- a/synapse/http/client.py +++ b/synapse/http/client.py @@ -341,6 +341,7 @@ class SimpleHttpClient: self.agent = ProxyAgent( self.reactor, + hs.get_reactor(), connectTimeout=15, contextFactory=self.hs.get_http_client_context_factory(), pool=pool, diff --git a/synapse/http/proxyagent.py b/synapse/http/proxyagent.py index e32d3f43e0..b730d2c634 100644 --- a/synapse/http/proxyagent.py +++ b/synapse/http/proxyagent.py @@ -39,6 +39,10 @@ class ProxyAgent(_AgentBase): reactor: twisted reactor to place outgoing connections. + proxy_reactor: twisted reactor to use for connections to the proxy server + reactor might have some blacklisting applied (i.e. for DNS queries), + but we need unblocked access to the proxy. + contextFactory (IPolicyForHTTPS): A factory for TLS contexts, to control the verification parameters of OpenSSL. The default is to use a `BrowserLikePolicyForHTTPS`, so unless you have special @@ -59,6 +63,7 @@ class ProxyAgent(_AgentBase): def __init__( self, reactor, + proxy_reactor=None, contextFactory=BrowserLikePolicyForHTTPS(), connectTimeout=None, bindAddress=None, @@ -68,6 +73,11 @@ class ProxyAgent(_AgentBase): ): _AgentBase.__init__(self, reactor, pool) + if proxy_reactor is None: + self.proxy_reactor = reactor + else: + self.proxy_reactor = proxy_reactor + self._endpoint_kwargs = {} if connectTimeout is not None: self._endpoint_kwargs["timeout"] = connectTimeout @@ -75,11 +85,11 @@ class ProxyAgent(_AgentBase): self._endpoint_kwargs["bindAddress"] = bindAddress self.http_proxy_endpoint = _http_proxy_endpoint( - http_proxy, reactor, **self._endpoint_kwargs + http_proxy, self.proxy_reactor, **self._endpoint_kwargs ) self.https_proxy_endpoint = _http_proxy_endpoint( - https_proxy, reactor, **self._endpoint_kwargs + https_proxy, self.proxy_reactor, **self._endpoint_kwargs ) self._policy_for_https = contextFactory @@ -137,7 +147,7 @@ class ProxyAgent(_AgentBase): request_path = uri elif parsed_uri.scheme == b"https" and self.https_proxy_endpoint: endpoint = HTTPConnectProxyEndpoint( - self._reactor, + self.proxy_reactor, self.https_proxy_endpoint, parsed_uri.host, parsed_uri.port, diff --git a/tests/http/test_proxyagent.py b/tests/http/test_proxyagent.py index 22abf76515..9a56e1c14a 100644 --- a/tests/http/test_proxyagent.py +++ b/tests/http/test_proxyagent.py @@ -15,12 +15,14 @@ import logging import treq +from netaddr import IPSet from twisted.internet import interfaces # noqa: F401 from twisted.internet.protocol import Factory from twisted.protocols.tls import TLSMemoryBIOFactory from twisted.web.http import HTTPChannel +from synapse.http.client import BlacklistingReactorWrapper from synapse.http.proxyagent import ProxyAgent from tests.http import TestServerTLSConnectionFactory, get_test_https_policy @@ -292,6 +294,134 @@ class MatrixFederationAgentTests(TestCase): body = self.successResultOf(treq.content(resp)) self.assertEqual(body, b"result") + def test_http_request_via_proxy_with_blacklist(self): + # The blacklist includes the configured proxy IP. + agent = ProxyAgent( + BlacklistingReactorWrapper( + self.reactor, ip_whitelist=None, ip_blacklist=IPSet(["1.0.0.0/8"]) + ), + self.reactor, + http_proxy=b"proxy.com:8888", + ) + + self.reactor.lookups["proxy.com"] = "1.2.3.5" + d = agent.request(b"GET", b"http://test.com") + + # there should be a pending TCP connection + clients = self.reactor.tcpClients + self.assertEqual(len(clients), 1) + (host, port, client_factory, _timeout, _bindAddress) = clients[0] + self.assertEqual(host, "1.2.3.5") + self.assertEqual(port, 8888) + + # make a test server, and wire up the client + http_server = self._make_connection( + client_factory, _get_test_protocol_factory() + ) + + # the FakeTransport is async, so we need to pump the reactor + self.reactor.advance(0) + + # now there should be a pending request + self.assertEqual(len(http_server.requests), 1) + + request = http_server.requests[0] + self.assertEqual(request.method, b"GET") + self.assertEqual(request.path, b"http://test.com") + self.assertEqual(request.requestHeaders.getRawHeaders(b"host"), [b"test.com"]) + request.write(b"result") + request.finish() + + self.reactor.advance(0) + + resp = self.successResultOf(d) + body = self.successResultOf(treq.content(resp)) + self.assertEqual(body, b"result") + + def test_https_request_via_proxy_with_blacklist(self): + # The blacklist includes the configured proxy IP. + agent = ProxyAgent( + BlacklistingReactorWrapper( + self.reactor, ip_whitelist=None, ip_blacklist=IPSet(["1.0.0.0/8"]) + ), + self.reactor, + contextFactory=get_test_https_policy(), + https_proxy=b"proxy.com", + ) + + self.reactor.lookups["proxy.com"] = "1.2.3.5" + d = agent.request(b"GET", b"https://test.com/abc") + + # there should be a pending TCP connection + clients = self.reactor.tcpClients + self.assertEqual(len(clients), 1) + (host, port, client_factory, _timeout, _bindAddress) = clients[0] + self.assertEqual(host, "1.2.3.5") + self.assertEqual(port, 1080) + + # make a test HTTP server, and wire up the client + proxy_server = self._make_connection( + client_factory, _get_test_protocol_factory() + ) + + # fish the transports back out so that we can do the old switcheroo + s2c_transport = proxy_server.transport + client_protocol = s2c_transport.other + c2s_transport = client_protocol.transport + + # the FakeTransport is async, so we need to pump the reactor + self.reactor.advance(0) + + # now there should be a pending CONNECT request + self.assertEqual(len(proxy_server.requests), 1) + + request = proxy_server.requests[0] + self.assertEqual(request.method, b"CONNECT") + self.assertEqual(request.path, b"test.com:443") + + # tell the proxy server not to close the connection + proxy_server.persistent = True + + # this just stops the http Request trying to do a chunked response + # request.setHeader(b"Content-Length", b"0") + request.finish() + + # now we can replace the proxy channel with a new, SSL-wrapped HTTP channel + ssl_factory = _wrap_server_factory_for_tls(_get_test_protocol_factory()) + ssl_protocol = ssl_factory.buildProtocol(None) + http_server = ssl_protocol.wrappedProtocol + + ssl_protocol.makeConnection( + FakeTransport(client_protocol, self.reactor, ssl_protocol) + ) + c2s_transport.other = ssl_protocol + + self.reactor.advance(0) + + server_name = ssl_protocol._tlsConnection.get_servername() + expected_sni = b"test.com" + self.assertEqual( + server_name, + expected_sni, + "Expected SNI %s but got %s" % (expected_sni, server_name), + ) + + # now there should be a pending request + self.assertEqual(len(http_server.requests), 1) + + request = http_server.requests[0] + self.assertEqual(request.method, b"GET") + self.assertEqual(request.path, b"/abc") + self.assertEqual(request.requestHeaders.getRawHeaders(b"host"), [b"test.com"]) + request.write(b"result") + request.finish() + + self.reactor.advance(0) + + resp = self.successResultOf(d) + body = self.successResultOf(treq.content(resp)) + self.assertEqual(body, b"result") + def _wrap_server_factory_for_tls(factory, sanlist=None): """Wrap an existing Protocol Factory with a test TLSMemoryBIOFactory