send SNI for federation requests

15 files changed, 71 insertions, 13 deletions

diff --git a/synapse/app/client_reader.py b/synapse/app/client_reader.py
index 654ddb8414..1c885e321c 100644
--- a/synapse/app/client_reader.py
+++ b/synapse/app/client_reader.py
@@ -153,11 +153,13 @@ def start(config_options):
     database_engine = create_engine(config.database_config)
 
     tls_server_context_factory = context_factory.ServerContextFactory(config)
+    tls_client_options_factory = context_factory.ClientTLSOptionsFactory(config)
 
     ss = ClientReaderServer(
         config.server_name,
         db_config=config.database_config,
         tls_server_context_factory=tls_server_context_factory,
+        tls_client_options_factory=tls_client_options_factory,
         config=config,
         version_string="Synapse/" + get_version_string(synapse),
         database_engine=database_engine,
diff --git a/synapse/app/event_creator.py b/synapse/app/event_creator.py
index 441467093a..ccbdd8b2df 100644
--- a/synapse/app/event_creator.py
+++ b/synapse/app/event_creator.py
@@ -171,11 +171,13 @@ def start(config_options):
     database_engine = create_engine(config.database_config)
 
     tls_server_context_factory = context_factory.ServerContextFactory(config)
+    tls_client_options_factory = context_factory.ClientTLSOptionsFactory(config)
 
     ss = EventCreatorServer(
         config.server_name,
         db_config=config.database_config,
         tls_server_context_factory=tls_server_context_factory,
+        tls_client_options_factory=tls_client_options_factory,
         config=config,
         version_string="Synapse/" + get_version_string(synapse),
         database_engine=database_engine,
diff --git a/synapse/app/federation_reader.py b/synapse/app/federation_reader.py
index b2415cc671..7fd20322f4 100644
--- a/synapse/app/federation_reader.py
+++ b/synapse/app/federation_reader.py
@@ -142,11 +142,13 @@ def start(config_options):
     database_engine = create_engine(config.database_config)
 
     tls_server_context_factory = context_factory.ServerContextFactory(config)
+    tls_client_options_factory = context_factory.ClientTLSOptionsFactory(config)
 
     ss = FederationReaderServer(
         config.server_name,
         db_config=config.database_config,
         tls_server_context_factory=tls_server_context_factory,
+        tls_client_options_factory=tls_client_options_factory,
         config=config,
         version_string="Synapse/" + get_version_string(synapse),
         database_engine=database_engine,
diff --git a/synapse/app/federation_sender.py b/synapse/app/federation_sender.py
index 13d2b70053..67dffaccbb 100644
--- a/synapse/app/federation_sender.py
+++ b/synapse/app/federation_sender.py
@@ -185,11 +185,13 @@ def start(config_options):
     config.send_federation = True
 
     tls_server_context_factory = context_factory.ServerContextFactory(config)
+    tls_client_options_factory = context_factory.ClientTLSOptionsFactory(config)
 
     ps = FederationSenderServer(
         config.server_name,
         db_config=config.database_config,
         tls_server_context_factory=tls_server_context_factory,
+        tls_client_options_factory=tls_client_options_factory,
         config=config,
         version_string="Synapse/" + get_version_string(synapse),
         database_engine=database_engine,
diff --git a/synapse/app/frontend_proxy.py b/synapse/app/frontend_proxy.py
index d2bae4ad03..d5638087a0 100644
--- a/synapse/app/frontend_proxy.py
+++ b/synapse/app/frontend_proxy.py
@@ -209,11 +209,13 @@ def start(config_options):
     database_engine = create_engine(config.database_config)
 
     tls_server_context_factory = context_factory.ServerContextFactory(config)
+    tls_client_options_factory = context_factory.ClientTLSOptionsFactory(config)
 
     ss = FrontendProxyServer(
         config.server_name,
         db_config=config.database_config,
         tls_server_context_factory=tls_server_context_factory,
+        tls_client_options_factory=tls_client_options_factory,
         config=config,
         version_string="Synapse/" + get_version_string(synapse),
         database_engine=database_engine,
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index ae5fc751d5..d48d68bc7e 100755
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -321,6 +321,7 @@ def setup(config_options):
     events.USE_FROZEN_DICTS = config.use_frozen_dicts
 
     tls_server_context_factory = context_factory.ServerContextFactory(config)
+    tls_client_options_factory = context_factory.ClientTLSOptionsFactory(config)
 
     database_engine = create_engine(config.database_config)
     config.database_config["args"]["cp_openfun"] = database_engine.on_new_connection
@@ -329,6 +330,7 @@ def setup(config_options):
         config.server_name,
         db_config=config.database_config,
         tls_server_context_factory=tls_server_context_factory,
+        tls_client_options_factory=tls_client_options_factory,
         config=config,
         version_string="Synapse/" + get_version_string(synapse),
         database_engine=database_engine,
diff --git a/synapse/app/media_repository.py b/synapse/app/media_repository.py
index 19a682cce3..cc3f31a438 100644
--- a/synapse/app/media_repository.py
+++ b/synapse/app/media_repository.py
@@ -156,11 +156,13 @@ def start(config_options):
     database_engine = create_engine(config.database_config)
 
     tls_server_context_factory = context_factory.ServerContextFactory(config)
+    tls_client_options_factory = context_factory.ClientTLSOptionsFactory(config)
 
     ss = MediaRepositoryServer(
         config.server_name,
         db_config=config.database_config,
         tls_server_context_factory=tls_server_context_factory,
+        tls_client_options_factory=tls_client_options_factory,
         config=config,
         version_string="Synapse/" + get_version_string(synapse),
         database_engine=database_engine,
diff --git a/synapse/app/user_dir.py b/synapse/app/user_dir.py
index f5726e3df6..51e7917ce2 100644
--- a/synapse/app/user_dir.py
+++ b/synapse/app/user_dir.py
@@ -213,11 +213,13 @@ def start(config_options):
     config.update_user_directory = True
 
     tls_server_context_factory = context_factory.ServerContextFactory(config)
+    tls_client_options_factory = context_factory.ClientTLSOptionsFactory(config)
 
     ps = UserDirectoryServer(
         config.server_name,
         db_config=config.database_config,
         tls_server_context_factory=tls_server_context_factory,
+        tls_client_options_factory=tls_client_options_factory,
         config=config,
         version_string="Synapse/" + get_version_string(synapse),
         database_engine=database_engine,
diff --git a/synapse/config/tls.py b/synapse/config/tls.py
index b66154bc7c..4e7d1bd93e 100644
--- a/synapse/config/tls.py
+++ b/synapse/config/tls.py
@@ -47,6 +47,8 @@ class TlsConfig(Config):
 
         self.tls_fingerprints = config["tls_fingerprints"]
 
+        self.tls_ignore_certificate_validation = config.get("tls_ignore_certificate_validation", False)
+
         # Check that our own certificate is included in the list of fingerprints
         # and include it if it is not.
         x509_certificate_bytes = crypto.dump_certificate(
@@ -73,6 +75,8 @@ class TlsConfig(Config):
         tls_private_key_path = base_key_name + ".tls.key"
         tls_dh_params_path = base_key_name + ".tls.dh"
 
+        tls_ignore_certificate_validation = False
+
         return """\
         # PEM encoded X509 certificate for TLS.
         # You can replace the self-signed certificate that synapse
@@ -117,6 +121,11 @@ class TlsConfig(Config):
         #
         tls_fingerprints: []
         # tls_fingerprints: [{"sha256": "<base64_encoded_sha256_fingerprint>"}]
+
+        # Ignore certificate validation for TLS client connections to other
+        # homeservers using federation. Don't enable this in a production
+        # environment, unless you know what you are doing!
+        tls_ignore_certificate_validation: %(tls_ignore_certificate_validation)s
         """ % locals()
 
     def read_tls_certificate(self, cert_path):
diff --git a/synapse/crypto/context_factory.py b/synapse/crypto/context_factory.py
index 0397f73ab4..297a5fb045 100644
--- a/synapse/crypto/context_factory.py
+++ b/synapse/crypto/context_factory.py
@@ -14,7 +14,8 @@
 
 from twisted.internet import ssl
 from OpenSSL import SSL, crypto
-from twisted.internet._sslverify import _defaultCurveName
+from twisted.internet._sslverify import _defaultCurveName, ClientTLSOptions, OpenSSLCertificateOptions, \
+    optionsForClientTLS
 
 import logging
 
@@ -48,3 +49,34 @@ class ServerContextFactory(ssl.ContextFactory):
 
     def getContext(self):
         return self._context
+
+
+class ClientTLSOptionsNoCertVerification(ClientTLSOptions):
+    """Redefinition of ClientTLSOptions to completely ignore certificate
+    validation. Should be kept in sync with the original class in Twisted.
+    This version of ClientTLSOptions is only intended for development use."""
+
+    def __init__(self, *args, **kwargs):
+        super(ClientTLSOptionsNoCertVerification, self).__init__(*args, **kwargs)
+
+        def do_nothing(*_args, **_kwargs):
+            pass
+
+        self._ctx.set_info_callback(do_nothing)
+
+
+class ClientTLSOptionsFactory(object):
+    """Factory for Twisted ClientTLSOptions that are used to make connections
+    to remote servers for federation."""
+
+    def __init__(self, config):
+        self._ignore_certificate_validation = config.tls_ignore_certificate_validation
+
+    def get_options(self, host):
+        if self._ignore_certificate_validation:
+            return ClientTLSOptionsNoCertVerification(
+                unicode(host),
+                OpenSSLCertificateOptions(verify=False).getContext()
+            )
+        else:
+            return optionsForClientTLS(unicode(host))
diff --git a/synapse/crypto/keyclient.py b/synapse/crypto/keyclient.py
index f1fd488b90..8e48f8a9cf 100644
--- a/synapse/crypto/keyclient.py
+++ b/synapse/crypto/keyclient.py
@@ -28,14 +28,14 @@ KEY_API_V1 = b"/_matrix/key/v1/"
 
 
 @defer.inlineCallbacks
-def fetch_server_key(server_name, ssl_context_factory, path=KEY_API_V1):
+def fetch_server_key(server_name, tls_client_options_factory, path=KEY_API_V1):
     """Fetch the keys for a remote server."""
 
     factory = SynapseKeyClientFactory()
     factory.path = path
     factory.host = server_name
     endpoint = matrix_federation_endpoint(
-        reactor, server_name, ssl_context_factory, timeout=30
+        reactor, server_name, tls_client_options_factory, timeout=30
     )
 
     for i in range(5):
diff --git a/synapse/crypto/keyring.py b/synapse/crypto/keyring.py
index 9b17ef0a08..9a1bb211fb 100644
--- a/synapse/crypto/keyring.py
+++ b/synapse/crypto/keyring.py
@@ -510,7 +510,7 @@ class Keyring(object):
                 continue
 
             (response, tls_certificate) = yield fetch_server_key(
-                server_name, self.hs.tls_server_context_factory,
+                server_name, self.tls_client_options_factory,
                 path=(b"/_matrix/key/v2/server/%s" % (
                     urllib.quote(requested_key_id),
                 )).encode("ascii"),
@@ -653,7 +653,7 @@ class Keyring(object):
         # Try to fetch the key from the remote server.
 
         (response, tls_certificate) = yield fetch_server_key(
-            server_name, self.hs.tls_server_context_factory
+            server_name, self.hs.tls_client_options_factory
         )
 
         # Check the response.
diff --git a/synapse/http/endpoint.py b/synapse/http/endpoint.py
index 87a482650d..e783f95719 100644
--- a/synapse/http/endpoint.py
+++ b/synapse/http/endpoint.py
@@ -26,7 +26,6 @@ import time
 
 logger = logging.getLogger(__name__)
 
-
 SERVER_CACHE = {}
 
 # our record of an individual server which can be tried to reach a destination.
@@ -38,15 +37,15 @@ _Server = collections.namedtuple(
 )
 
 
-def matrix_federation_endpoint(reactor, destination, ssl_context_factory=None,
+def matrix_federation_endpoint(reactor, destination, tls_client_options_factory=None,
                                timeout=None):
     """Construct an endpoint for the given matrix destination.
 
     Args:
         reactor: Twisted reactor.
         destination (bytes): The name of the server to connect to.
-        ssl_context_factory (twisted.internet.ssl.ContextFactory): Factory
-            which generates SSL contexts to use for TLS.
+        tls_client_options_factory (synapse.crypto.context_factory.ClientTLSOptionsFactory): 
+            Factory which generates TLS options for client connections.
         timeout (int): connection timeout in seconds
     """
 
@@ -59,13 +58,13 @@ def matrix_federation_endpoint(reactor, destination, ssl_context_factory=None,
     if timeout is not None:
         endpoint_kw_args.update(timeout=timeout)
 
-    if ssl_context_factory is None:
+    if tls_client_options_factory is None:
         transport_endpoint = HostnameEndpoint
         default_port = 8008
     else:
         def transport_endpoint(reactor, host, port, timeout):
             return wrapClientTLS(
-                ssl_context_factory,
+                tls_client_options_factory.get_options(unicode(host)),
                 HostnameEndpoint(reactor, host, port, timeout=timeout))
         default_port = 8448
 
diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py
index 4e0399e762..66796a202f 100644
--- a/synapse/http/matrixfederationclient.py
+++ b/synapse/http/matrixfederationclient.py
@@ -62,14 +62,14 @@ MAX_SHORT_RETRIES = 3
 
 class MatrixFederationEndpointFactory(object):
     def __init__(self, hs):
-        self.tls_server_context_factory = hs.tls_server_context_factory
+        self.tls_client_options_factory = hs.tls_client_options_factory
 
     def endpointForURI(self, uri):
         destination = uri.netloc
 
         return matrix_federation_endpoint(
             reactor, destination, timeout=10,
-            ssl_context_factory=self.tls_server_context_factory
+            tls_client_options_factory = self.tls_client_options_factory
         )
 
 
diff --git a/tests/utils.py b/tests/utils.py
index 189fd2711c..0b501e0786 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -114,6 +114,7 @@ def setup_test_homeserver(name="test", datastore=None, config=None, reactor=None
             database_engine=db_engine,
             room_list_handler=object(),
             tls_server_context_factory=Mock(),
+            tls_client_options_factory=Mock(),
             reactor=reactor,
             **kargs
         )
@@ -134,6 +135,7 @@ def setup_test_homeserver(name="test", datastore=None, config=None, reactor=None
             database_engine=db_engine,
             room_list_handler=object(),
             tls_server_context_factory=Mock(),
+            tls_client_options_factory=Mock(),
             **kargs
         )