1#! /usr/bin/env perl
2# Copyright 2016-2021 The OpenSSL Project Authors. All Rights Reserved.
3#
4# Licensed under the Apache License 2.0 (the "License").  You may not use
5# this file except in compliance with the License.  You can obtain a copy
6# in the file LICENSE in the source distribution or at
7# https://www.openssl.org/source/license.html
8
9use strict;
10use OpenSSL::Test qw/:DEFAULT cmdstr srctop_file bldtop_dir/;
11use OpenSSL::Test::Utils;
12use TLSProxy::Proxy;
13
14my $test_name = "test_sslsignature";
15setup($test_name);
16
17plan skip_all => "TLSProxy isn't usable on $^O"
18    if $^O =~ /^(VMS)$/;
19
20plan skip_all => "$test_name needs the dynamic engine feature enabled"
21    if disabled("engine") || disabled("dynamic-engine");
22
23plan skip_all => "$test_name needs the sock feature enabled"
24    if disabled("sock");
25
26plan skip_all => "$test_name needs TLS enabled"
27    if alldisabled(available_protocols("tls"));
28
29my $proxy = TLSProxy::Proxy->new(
30    undef,
31    cmdstr(app(["openssl"]), display => 1),
32    srctop_file("apps", "server.pem"),
33    (!$ENV{HARNESS_ACTIVE} || $ENV{HARNESS_VERBOSE})
34);
35
36use constant {
37    NO_CORRUPTION => 0,
38    CORRUPT_SERVER_CERT_VERIFY => 1,
39    CORRUPT_CLIENT_CERT_VERIFY => 2,
40    CORRUPT_TLS1_2_SERVER_KEY_EXCHANGE => 3,
41};
42
43$proxy->filter(\&signature_filter);
44
45#Test 1: No corruption should succeed
46my $testtype = NO_CORRUPTION;
47$proxy->clientflags("-no_tls1_3") if disabled("ec") && disabled("dh");
48$proxy->start() or plan skip_all => "Unable to start up Proxy for tests";
49plan tests => 4;
50ok(TLSProxy::Message->success, "No corruption");
51
52SKIP: {
53    skip "TLSv1.3 disabled", 1
54        if disabled("tls1_3") || (disabled("ec") && disabled("dh"));
55
56    #Test 2: Corrupting a server CertVerify signature in TLSv1.3 should fail
57    $proxy->clear();
58    $testtype = CORRUPT_SERVER_CERT_VERIFY;
59    $proxy->start();
60    ok(TLSProxy::Message->fail, "Corrupt server TLSv1.3 CertVerify");
61
62    #Test x: Corrupting a client CertVerify signature in TLSv1.3 should fail
63    #$proxy->clear();
64    #$testtype = CORRUPT_CLIENT_CERT_VERIFY;
65    #$proxy->serverflags("-Verify 5");
66    #$proxy->clientflags("-cert ".srctop_file("apps", "server.pem"));
67    #$proxy->start();
68    #ok(TLSProxy::Message->fail, "Corrupt client TLSv1.3 CertVerify");
69    #TODO(TLS1.3): This test fails due to a problem in s_server/TLSProxy.
70    #Currently a connection is counted as "successful" if the client ends it
71    #with a close_notify. In TLSProxy the client initiates the closure of the
72    #connection so really we should not count it as successful until s_server
73    #has also responded with a close_notify. However s_server never sends a
74    #close_notify - it just closes the connection. Fixing this would be a
75    #significant change to the long established behaviour of s_server.
76    #Unfortunately in this test, it is the server that notices the incorrect
77    #signature and responds with an appropriate alert. However s_client never
78    #sees that because it occurs after the server Finished has been sent.
79    #Therefore s_client just continues to send its application data and sends
80    #its close_notify regardless. TLSProxy sees this and thinks that the
81    #connection was successful when in fact it was not. There isn't an easy fix
82    #for this, so leaving this test commented out for now.
83}
84
85SKIP: {
86    skip "TLS <= 1.2 disabled", 2
87        if alldisabled(("ssl3", "tls1", "tls1_1", "tls1_2"));
88
89    #Test 3: Corrupting a CertVerify signature in <=TLSv1.2 should fail
90    $proxy->clear();
91    $testtype = CORRUPT_CLIENT_CERT_VERIFY;
92    $proxy->serverflags("-Verify 5");
93    $proxy->clientflags("-no_tls1_3 -cert ".srctop_file("apps", "server.pem"));
94    $proxy->start();
95    ok(TLSProxy::Message->fail, "Corrupt <=TLSv1.2 CertVerify");
96
97    SKIP: {
98        skip "DH disabled", 1 if disabled("dh");
99
100        #Test 4: Corrupting a ServerKeyExchange signature in <=TLSv1.2 should
101        #fail
102        $proxy->clear();
103        $testtype = CORRUPT_TLS1_2_SERVER_KEY_EXCHANGE;
104        $proxy->clientflags("-no_tls1_3");
105        $proxy->cipherc('DHE-RSA-AES128-SHA');
106        $proxy->ciphers('DHE-RSA-AES128-SHA');
107        $proxy->start();
108        ok(TLSProxy::Message->fail, "Corrupt <=TLSv1.2 ServerKeyExchange");
109    }
110}
111
112sub signature_filter
113{
114    my $proxy = shift;
115    my $flight;
116    my $mt = TLSProxy::Message::MT_CERTIFICATE_VERIFY;
117
118    if ($testtype == CORRUPT_SERVER_CERT_VERIFY
119            || $testtype == CORRUPT_TLS1_2_SERVER_KEY_EXCHANGE
120            || (!disabled("tls1_3") && $testtype == NO_CORRUPTION)) {
121        $flight = 1;
122    } else {
123        $flight = 2;
124    }
125
126    # We're only interested in the initial server flight
127    return if ($proxy->flight != $flight);
128
129    $mt = TLSProxy::Message::MT_SERVER_KEY_EXCHANGE
130        if ($testtype == CORRUPT_TLS1_2_SERVER_KEY_EXCHANGE);
131
132    foreach my $message (@{$proxy->message_list}) {
133        if ($message->mt == $mt) {
134            my $sig = $message->signature();
135            my $sigbase = substr($sig, 0, -1);
136            my $sigend = unpack("C", substr($sig, -1));
137
138            #Flip bits in final byte of signature to corrupt the sig
139            $sigend ^= 0xff unless $testtype == NO_CORRUPTION;
140
141            $message->signature($sigbase.pack("C", $sigend));
142            $message->repack();
143        }
144    }
145}
146