test/recipes/70-test_sslcbcpadding.t

   1 #! /usr/bin/env perl
   2 # Copyright 2016-2018 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
   9 use strict;
  10 use feature 'state';
  11
  12 use OpenSSL::Test qw/:DEFAULT cmdstr srctop_file bldtop_dir/;
  13 use OpenSSL::Test::Utils;
  14 use TLSProxy::Proxy;
  15
  16 my $test_name = "test_sslcbcpadding";
  17 setup($test_name);
  18
  19 plan skip_all => "TLSProxy isn't usable on $^O"
  20     if $^O =~ /^(VMS)$/;
  21
  22 plan skip_all => "$test_name needs the dynamic engine feature enabled"
  23     if disabled("engine") || disabled("dynamic-engine");
  24
  25 plan skip_all => "$test_name needs the sock feature enabled"
  26     if disabled("sock");
  27
  28 plan skip_all => "$test_name needs TLSv1.2 enabled"
  29     if disabled("tls1_2");
  30
  31 $ENV{OPENSSL_ia32cap} = '~0x200000200000000';
  32 my $proxy = TLSProxy::Proxy->new(
  33     \&add_maximal_padding_filter,
  34     cmdstr(app(["openssl"]), display => 1),
  35     srctop_file("apps", "server.pem"),
  36     (!$ENV{HARNESS_ACTIVE} || $ENV{HARNESS_VERBOSE})
  37 );
  38
  39 # TODO: We could test all 256 values, but then the log file gets too large for
  40 # CI. See https://github.com/openssl/openssl/issues/1440.
  41 my @test_offsets = (0, 128, 254, 255);
  42
  43 # Test that maximally-padded records are accepted.
  44 my $bad_padding_offset = -1;
  45 $proxy->serverflags("-tls1_2");
  46 $proxy->clientflags("-no_tls1_3");
  47 $proxy->serverconnects(1 + scalar(@test_offsets));
  48 $proxy->start() or plan skip_all => "Unable to start up Proxy for tests";
  49 plan tests => 1 + scalar(@test_offsets);
  50 ok(TLSProxy::Message->success(), "Maximally-padded record test");
  51
  52 # Test that invalid padding is rejected.
  53 my $fatal_alert;    # set by add_maximal_padding_filter on client's fatal alert
  54
  55 foreach my $offset (@test_offsets) {
  56     $bad_padding_offset = $offset;
  57     $fatal_alert = 0;
  58     $proxy->clearClient();
  59     $proxy->clientflags("-no_tls1_3");
  60     $proxy->clientstart();
  61     ok($fatal_alert, "Invalid padding byte $bad_padding_offset");
  62 }
  63
  64 sub add_maximal_padding_filter
  65 {
  66     my $proxy = shift;
  67     my $messages = $proxy->message_list;
  68     state $sent_corrupted_payload;
  69
  70     if ($proxy->flight == 0) {
  71         # Disable Encrypt-then-MAC.
  72         foreach my $message (@{$messages}) {
  73             if ($message->mt != TLSProxy::Message::MT_CLIENT_HELLO) {
  74                 next;
  75             }
  76
  77             $message->delete_extension(TLSProxy::Message::EXT_ENCRYPT_THEN_MAC);
  78             $message->process_extensions();
  79             $message->repack();
  80         }
  81         $sent_corrupted_payload = 0;
  82         return;
  83     }
  84
  85     my $last_message = @{$messages}[-1];
  86     if (defined($last_message)
  87         && $last_message->server
  88         && $last_message->mt == TLSProxy::Message::MT_FINISHED
  89         && !@{$last_message->records}[0]->{sent}) {
  90
  91         # Insert a maximally-padded record. Assume a block size of 16 (AES) and
  92         # a MAC length of 20 (SHA-1).
  93         my $block_size = 16;
  94         my $mac_len = 20;
  95
  96         # Size the plaintext so that 256 is a valid padding.
  97         my $plaintext_len = $block_size - ($mac_len % $block_size);
  98         my $plaintext = "A" x $plaintext_len;
  99
 100         my $data = "B" x $block_size; # Explicit IV.
 101         $data .= $plaintext;
 102         $data .= TLSProxy::Proxy::fill_known_data($mac_len); # MAC.
 103
 104         # Add padding.
 105         for (my $i = 0; $i < 256; $i++) {
 106             if ($i == $bad_padding_offset) {
 107                 $sent_corrupted_payload = 1;
 108                 $data .= "\xfe";
 109             } else {
 110                 $data .= "\xff";
 111             }
 112         }
 113
 114         my $record = TLSProxy::Record->new(
 115             $proxy->flight,
 116             TLSProxy::Record::RT_APPLICATION_DATA,
 117             TLSProxy::Record::VERS_TLS_1_2,
 118             length($data),
 119             0,
 120             length($data),
 121             $plaintext_len,
 122             $data,
 123             $plaintext,
 124         );
 125
 126         # Send the record immediately after the server Finished.
 127         push @{$proxy->record_list}, $record;
 128     } elsif ($sent_corrupted_payload) {
 129         # Check for bad_record_mac from client
 130         my $last_record = @{$proxy->record_list}[-1];
 131         $fatal_alert = 1 if $last_record->is_fatal_alert(0) == 20;
 132     }
 133 }