def test_immediate_disconnect(self, tctx: context.Context, close_at):
"""Test the scenario where the client is disconnecting during the handshake.
This may happen because they are not interested in the connection anymore, or because they do not like
the proxy certificate."""
playbook, client_layer, tssl_client = make_client_tls_layer(
tctx, sni=b"wrong.host.mitmproxy.org")
playbook.logs = True
playbook >> events.DataReceived(tctx.client, tssl_client.bio_read())
playbook << tls.TlsClienthelloHook(tutils.Placeholder())
if close_at == "tls_clienthello":
assert (playbook >> events.ConnectionClosed(
tctx.client) >> tutils.reply(to=-2) << tls.TlsStartClientHook(
tutils.Placeholder()) >> reply_tls_start_client() <<
commands.CloseConnection(tctx.client))
return
playbook >> tutils.reply()
playbook << tls.TlsStartClientHook(tutils.Placeholder())
if close_at == "tls_start_client":
assert (playbook >> events.ConnectionClosed(tctx.client) >>
reply_tls_start_client(to=-2) << commands.CloseConnection(
tctx.client))
return
assert (playbook >> reply_tls_start_client() << commands.SendData(
tctx.client, tutils.Placeholder()
) >> events.ConnectionClosed(tctx.client) << commands.Log(
"Client TLS handshake failed. The client disconnected during the handshake. "
"If this happens consistently for wrong.host.mitmproxy.org, this may indicate that the "
"client does not trust the proxy's certificate.", "info") <<
commands.CloseConnection(tctx.client))
def test_mitmproxy_ca_is_untrusted(self, tctx: context.Context):
"""Test the scenario where the client doesn't trust the mitmproxy CA."""
playbook, client_layer, tssl_client = make_client_tls_layer(
tctx, sni=b"wrong.host.mitmproxy.org")
playbook.logs = True
data = tutils.Placeholder(bytes)
assert (
playbook >> events.DataReceived(
tctx.client, tssl_client.bio_read()) << tls.TlsClienthelloHook(
tutils.Placeholder()) >> tutils.reply() <<
tls.TlsStartClientHook(tutils.Placeholder()) >>
reply_tls_start_client() << commands.SendData(tctx.client, data))
tssl_client.bio_write(data())
with pytest.raises(ssl.SSLCertVerificationError):
tssl_client.do_handshake()
# Finish Handshake
assert (playbook >> events.DataReceived(
tctx.client, tssl_client.bio_read()
) << commands.Log(
"Client TLS handshake failed. The client does not trust the proxy's certificate "
"for wrong.host.mitmproxy.org (sslv3 alert bad certificate)",
"warn") << commands.CloseConnection(tctx.client) >>
events.ConnectionClosed(tctx.client))
assert not tctx.client.tls_established
def test_client_only(self, tctx: context.Context):
"""Test TLS with client only"""
playbook, client_layer, tssl_client = make_client_tls_layer(tctx)
client_layer.debug = " "
assert not tctx.client.tls_established
# Send ClientHello, receive ServerHello
data = tutils.Placeholder(bytes)
assert (
playbook >> events.DataReceived(
tctx.client, tssl_client.bio_read()) << tls.TlsClienthelloHook(
tutils.Placeholder()) >> tutils.reply() <<
tls.TlsStartClientHook(tutils.Placeholder()) >>
reply_tls_start_client() << commands.SendData(tctx.client, data))
tssl_client.bio_write(data())
tssl_client.do_handshake()
# Finish Handshake
interact(playbook, tctx.client, tssl_client)
assert tssl_client.obj.getpeercert(True)
assert tctx.client.tls_established
# Echo
_test_echo(playbook, tssl_client, tctx.client)
other_server = Server(None)
assert (playbook >> events.DataReceived(other_server, b"Plaintext") <<
commands.SendData(other_server, b"plaintext"))
def test_server_required(self, tctx, server_state):
"""
Test the scenario where a server connection is required (for example, because of an unknown ALPN)
to establish TLS with the client.
"""
if server_state == "open":
tctx.server.state = ConnectionState.OPEN
tssl_server = SSLTest(server_side=True, alpn=["quux"])
playbook, client_layer, tssl_client = make_client_tls_layer(
tctx, alpn=["quux"])
# We should now get instructed to open a server connection.
data = tutils.Placeholder(bytes)
def require_server_conn(client_hello: ClientHelloData) -> None:
client_hello.establish_server_tls_first = True
(playbook >> events.DataReceived(tctx.client, tssl_client.bio_read())
<< tls.TlsClienthelloHook(tutils.Placeholder()) >>
tutils.reply(side_effect=require_server_conn))
if server_state == "closed":
(playbook << commands.OpenConnection(tctx.server) >>
tutils.reply(None))
assert (playbook << tls.TlsStartServerHook(tutils.Placeholder()) >>
reply_tls_start_server(alpn=b"quux") << commands.SendData(
tctx.server, data))
# Establish TLS with the server...
tssl_server.bio_write(data())
with pytest.raises(ssl.SSLWantReadError):
tssl_server.do_handshake()
data = tutils.Placeholder(bytes)
assert (playbook >> events.DataReceived(tctx.server,
tssl_server.bio_read()) <<
tls.TlsEstablishedServerHook(tutils.Placeholder()) >>
tutils.reply() << commands.SendData(tctx.server, data) <<
tls.TlsStartClientHook(tutils.Placeholder()))
tssl_server.bio_write(data())
assert tctx.server.tls_established
# Server TLS is established, we can now reply to the client handshake...
data = tutils.Placeholder(bytes)
assert (playbook >> reply_tls_start_client(alpn=b"quux") <<
commands.SendData(tctx.client, data))
tssl_client.bio_write(data())
tssl_client.do_handshake()
finish_handshake(playbook, tctx.client, tssl_client)
# Both handshakes completed!
assert tctx.client.tls_established
assert tctx.server.tls_established
assert tctx.server.sni == tctx.client.sni
assert tctx.client.alpn == b"quux"
assert tctx.server.alpn == b"quux"
_test_echo(playbook, tssl_server, tctx.server)
_test_echo(playbook, tssl_client, tctx.client)
def test_unsupported_protocol(self, tctx: context.Context):
"""Test the scenario where the client only supports an outdated TLS version by default."""
playbook, client_layer, tssl_client = make_client_tls_layer(
tctx, max_ver=ssl.TLSVersion.TLSv1_2)
playbook.logs = True
assert (playbook >> events.DataReceived(
tctx.client, tssl_client.bio_read()
) << tls.TlsClienthelloHook(tutils.Placeholder(
)) >> tutils.reply() << tls.TlsStartClientHook(tutils.Placeholder(
)) >> reply_tls_start_client() << commands.Log(
"Client TLS handshake failed. Client and mitmproxy cannot agree on a TLS version to "
"use. You may need to adjust mitmproxy's tls_version_client_min option.",
"warn") << commands.CloseConnection(tctx.client))
