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#! /usr/bin/env perl
# Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
#
# Licensed under the OpenSSL license (the "License"). You may not use
# this file except in compliance with the License. You can obtain a copy
# in the file LICENSE in the source distribution or at
# https://www.openssl.org/source/license.html
use strict;
use feature 'state';
use OpenSSL::Test qw/:DEFAULT cmdstr srctop_file bldtop_dir/;
use OpenSSL::Test::Utils;
use TLSProxy::Proxy;
my $test_name = "test_sslcbcpadding";
setup($test_name);
plan skip_all => "TLSProxy isn't usable on $^O"
if $^O =~ /^(VMS)$/;
plan skip_all => "$test_name needs the dynamic engine feature enabled"
if disabled("engine") || disabled("dynamic-engine");
plan skip_all => "$test_name needs the sock feature enabled"
if disabled("sock");
plan skip_all => "$test_name needs TLSv1.2 enabled"
if disabled("tls1_2");
$ENV{OPENSSL_ia32cap} = '~0x200000200000000';
my $proxy = TLSProxy::Proxy->new(
\&add_maximal_padding_filter,
cmdstr(app(["openssl"]), display => 1),
srctop_file("apps", "server.pem"),
(!$ENV{HARNESS_ACTIVE} || $ENV{HARNESS_VERBOSE})
);
# TODO: We could test all 256 values, but then the log file gets too large for
# CI. See https://github.com/openssl/openssl/issues/1440.
my @test_offsets = (0, 128, 254, 255);
# Test that maximally-padded records are accepted.
my $bad_padding_offset = -1;
$proxy->serverflags("-tls1_2");
$proxy->serverconnects(1 + scalar(@test_offsets));
$proxy->start() or plan skip_all => "Unable to start up Proxy for tests";
plan tests => 1 + scalar(@test_offsets);
ok(TLSProxy::Message->success(), "Maximally-padded record test");
# Test that invalid padding is rejected.
my $fatal_alert; # set by add_maximal_padding_filter on client's fatal alert
foreach my $offset (@test_offsets) {
$bad_padding_offset = $offset;
$fatal_alert = 0;
$proxy->clearClient();
$proxy->clientstart();
ok($fatal_alert, "Invalid padding byte $bad_padding_offset");
}
sub add_maximal_padding_filter
{
my $proxy = shift;
my $messages = $proxy->message_list;
state $sent_corrupted_payload;
if ($proxy->flight == 0) {
# Disable Encrypt-then-MAC.
foreach my $message (@{$messages}) {
if ($message->mt != TLSProxy::Message::MT_CLIENT_HELLO) {
next;
}
$message->delete_extension(TLSProxy::Message::EXT_ENCRYPT_THEN_MAC);
$message->process_extensions();
$message->repack();
}
$sent_corrupted_payload = 0;
return;
}
my $last_message = @{$messages}[-1];
if (defined($last_message)
&& $last_message->server
&& $last_message->mt == TLSProxy::Message::MT_FINISHED
&& !@{$last_message->records}[0]->{sent}) {
# Insert a maximally-padded record. Assume a block size of 16 (AES) and
# a MAC length of 20 (SHA-1).
my $block_size = 16;
my $mac_len = 20;
# Size the plaintext so that 256 is a valid padding.
my $plaintext_len = $block_size - ($mac_len % $block_size);
my $plaintext = "A" x $plaintext_len;
my $data = "B" x $block_size; # Explicit IV.
$data .= $plaintext;
$data .= TLSProxy::Proxy::fill_known_data($mac_len); # MAC.
# Add padding.
for (my $i = 0; $i < 256; $i++) {
if ($i == $bad_padding_offset) {
$sent_corrupted_payload = 1;
$data .= "\xfe";
} else {
$data .= "\xff";
}
}
my $record = TLSProxy::Record->new(
$proxy->flight,
TLSProxy::Record::RT_APPLICATION_DATA,
TLSProxy::Record::VERS_TLS_1_2,
length($data),
0,
length($data),
$plaintext_len,
$data,
$plaintext,
);
# Send the record immediately after the server Finished.
push @{$proxy->record_list}, $record;
} elsif ($sent_corrupted_payload) {
# Check for bad_record_mac from client
my $last_record = @{$proxy->record_list}[-1];
$fatal_alert = 1 if $last_record->is_fatal_alert(0) == 20;
}
}
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