Don't send IP addresses as SNI (#4452)

The problem here is that we have cut-and-pasted an impl from Twisted, and then
failed to maintain it. It was fixed in Twisted in
https://github.com/twisted/twisted/pull/1047/files; let's do the same here.
This commit is contained in:
Richard van der Hoff 2019-01-24 09:34:44 +00:00 committed by GitHub
parent 6b90ae6efc
commit 97fd29c019
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3 changed files with 73 additions and 6 deletions

1
changelog.d/4452.bugfix Normal file
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@ -0,0 +1 @@
Don't send IP addresses as SNI

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@ -17,6 +17,7 @@ from zope.interface import implementer
from OpenSSL import SSL, crypto
from twisted.internet._sslverify import _defaultCurveName
from twisted.internet.abstract import isIPAddress, isIPv6Address
from twisted.internet.interfaces import IOpenSSLClientConnectionCreator
from twisted.internet.ssl import CertificateOptions, ContextFactory
from twisted.python.failure import Failure
@ -98,8 +99,14 @@ class ClientTLSOptions(object):
def __init__(self, hostname, ctx):
self._ctx = ctx
self._hostname = hostname
self._hostnameBytes = _idnaBytes(hostname)
if isIPAddress(hostname) or isIPv6Address(hostname):
self._hostnameBytes = hostname.encode('ascii')
self._sendSNI = False
else:
self._hostnameBytes = _idnaBytes(hostname)
self._sendSNI = True
ctx.set_info_callback(
_tolerateErrors(self._identityVerifyingInfoCallback)
)
@ -111,7 +118,9 @@ class ClientTLSOptions(object):
return connection
def _identityVerifyingInfoCallback(self, connection, where, ret):
if where & SSL.SSL_CB_HANDSHAKE_START:
# Literal IPv4 and IPv6 addresses are not permitted
# as host names according to the RFCs
if where & SSL.SSL_CB_HANDSHAKE_START and self._sendSNI:
connection.set_tlsext_host_name(self._hostnameBytes)

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@ -46,7 +46,7 @@ class MatrixFederationAgentTests(TestCase):
_srv_resolver=self.mock_resolver,
)
def _make_connection(self, client_factory):
def _make_connection(self, client_factory, expected_sni):
"""Builds a test server, and completes the outgoing client connection
Returns:
@ -69,9 +69,17 @@ class MatrixFederationAgentTests(TestCase):
# tell the server tls protocol to send its stuff back to the client, too
server_tls_protocol.makeConnection(FakeTransport(client_protocol, self.reactor))
# finally, give the reactor a pump to get the TLS juices flowing.
# give the reactor a pump to get the TLS juices flowing.
self.reactor.pump((0.1,))
# check the SNI
server_name = server_tls_protocol._tlsConnection.get_servername()
self.assertEqual(
server_name,
expected_sni,
"Expected SNI %s but got %s" % (expected_sni, server_name),
)
# fish the test server back out of the server-side TLS protocol.
return server_tls_protocol.wrappedProtocol
@ -113,7 +121,10 @@ class MatrixFederationAgentTests(TestCase):
self.assertEqual(port, 8448)
# make a test server, and wire up the client
http_server = self._make_connection(client_factory)
http_server = self._make_connection(
client_factory,
expected_sni=b"testserv",
)
self.assertEqual(len(http_server.requests), 1)
request = http_server.requests[0]
@ -150,6 +161,52 @@ class MatrixFederationAgentTests(TestCase):
json = self.successResultOf(treq.json_content(response))
self.assertEqual(json, {"a": 1})
def test_get_ip_address(self):
"""
Test the behaviour when the server name contains an explicit IP (with no port)
"""
# the SRV lookup will return an empty list (XXX: why do we even do an SRV lookup?)
self.mock_resolver.resolve_service.side_effect = lambda _: []
# then there will be a getaddrinfo on the IP
self.reactor.lookups["1.2.3.4"] = "1.2.3.4"
test_d = self._make_get_request(b"matrix://1.2.3.4/foo/bar")
# Nothing happened yet
self.assertNoResult(test_d)
self.mock_resolver.resolve_service.assert_called_once()
# Make sure treq is trying to connect
clients = self.reactor.tcpClients
self.assertEqual(len(clients), 1)
(host, port, client_factory, _timeout, _bindAddress) = clients[0]
self.assertEqual(host, '1.2.3.4')
self.assertEqual(port, 8448)
# make a test server, and wire up the client
http_server = self._make_connection(
client_factory,
expected_sni=None,
)
self.assertEqual(len(http_server.requests), 1)
request = http_server.requests[0]
self.assertEqual(request.method, b'GET')
self.assertEqual(request.path, b'/foo/bar')
# XXX currently broken
# self.assertEqual(
# request.requestHeaders.getRawHeaders(b'host'),
# [b'1.2.3.4:8448']
# )
# finish the request
request.finish()
self.reactor.pump((0.1,))
self.successResultOf(test_d)
def _check_logcontext(context):
current = LoggingContext.current_context()