From 301b870546d1c7b2d8f0d66e04a2596142f0399f Mon Sep 17 00:00:00 2001
From: Matt Caswell <matt@openssl.org>
Date: Fri, 21 Jun 2024 14:29:26 +0100
Subject: [PATCH 10/10] Add a test for an empty NextProto message
It is valid according to the spec for a NextProto message to have no
protocols listed in it. The OpenSSL implementation however does not allow
us to create such a message. In order to check that we work as expected
when communicating with a client that does generate such messages we have
to use a TLSProxy test.
Follow on from CVE-2024-5535
Reviewed-by: Neil Horman <nhorman@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/24717)
---
test/recipes/70-test_npn.t | 73 +++++++++++++++++++++++++++++++++
util/perl/TLSProxy/Message.pm | 9 ++++
util/perl/TLSProxy/NextProto.pm | 54 ++++++++++++++++++++++++
util/perl/TLSProxy/Proxy.pm | 1 +
4 files changed, 137 insertions(+)
create mode 100644 test/recipes/70-test_npn.t
create mode 100644 util/perl/TLSProxy/NextProto.pm
diff --git a/test/recipes/70-test_npn.t b/test/recipes/70-test_npn.t
new file mode 100644
index 0000000000..f82e71af6a
--- /dev/null
+++ b/test/recipes/70-test_npn.t
@@ -0,0 +1,73 @@
+#! /usr/bin/env perl
+# Copyright 2024 The OpenSSL Project Authors. All Rights Reserved.
+#
+# Licensed under the Apache License 2.0 (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 OpenSSL::Test qw/:DEFAULT cmdstr srctop_file/;
+use OpenSSL::Test::Utils;
+
+use TLSProxy::Proxy;
+
+my $test_name = "test_npn";
+setup($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 => "$test_name needs NPN enabled"
+ if disabled("nextprotoneg");
+
+plan skip_all => "$test_name needs TLSv1.2 enabled"
+ if disabled("tls1_2");
+
+my $proxy = TLSProxy::Proxy->new(
+ undef,
+ cmdstr(app(["openssl"]), display => 1),
+ srctop_file("apps", "server.pem"),
+ (!$ENV{HARNESS_ACTIVE} || $ENV{HARNESS_VERBOSE})
+);
+
+$proxy->start() or plan skip_all => "Unable to start up Proxy for tests";
+plan tests => 1;
+
+my $npnseen = 0;
+
+# Test 1: Check sending an empty NextProto message from the client works. This is
+# valid as per the spec, but OpenSSL does not allow you to send it.
+# Therefore we must be prepared to receive such a message but we cannot
+# generate it except via TLSProxy
+$proxy->clear();
+$proxy->filter(\&npn_filter);
+$proxy->clientflags("-nextprotoneg foo -no_tls1_3");
+$proxy->serverflags("-nextprotoneg foo");
+$proxy->start();
+ok($npnseen && TLSProxy::Message->success(), "Empty NPN message");
+
+sub npn_filter
+{
+ my $proxy = shift;
+ my $message;
+
+ # The NextProto message always appears in flight 2
+ return if $proxy->flight != 2;
+
+ foreach my $message (@{$proxy->message_list}) {
+ if ($message->mt == TLSProxy::Message::MT_NEXT_PROTO) {
+ # Our TLSproxy NextProto message support doesn't support parsing of
+ # the message. If we repack it just creates an empty NextProto
+ # message - which is exactly the scenario we want to test here.
+ $message->repack();
+ $npnseen = 1;
+ }
+ }
+}
diff --git a/util/perl/TLSProxy/Message.pm b/util/perl/TLSProxy/Message.pm
index ce22187569..fb41b2ffc8 100644
--- a/util/perl/TLSProxy/Message.pm
+++ b/util/perl/TLSProxy/Message.pm
@@ -384,6 +384,15 @@ sub create_message
[@message_frag_lens]
);
$message->parse();
+ } elsif ($mt == MT_NEXT_PROTO) {
+ $message = TLSProxy::NextProto->new(
+ $server,
+ $data,
+ [@message_rec_list],
+ $startoffset,
+ [@message_frag_lens]
+ );
+ $message->parse();
} else {
#Unknown message type
$message = TLSProxy::Message->new(
diff --git a/util/perl/TLSProxy/NextProto.pm b/util/perl/TLSProxy/NextProto.pm
new file mode 100644
index 0000000000..0e18347546
--- /dev/null
+++ b/util/perl/TLSProxy/NextProto.pm
@@ -0,0 +1,54 @@
+# Copyright 2024 The OpenSSL Project Authors. All Rights Reserved.
+#
+# Licensed under the Apache License 2.0 (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;
+
+package TLSProxy::NextProto;
+
+use vars '@ISA';
+push @ISA, 'TLSProxy::Message';
+
+sub new
+{
+ my $class = shift;
+ my ($server,
+ $data,
+ $records,
+ $startoffset,
+ $message_frag_lens) = @_;
+
+ my $self = $class->SUPER::new(
+ $server,
+ TLSProxy::Message::MT_NEXT_PROTO,
+ $data,
+ $records,
+ $startoffset,
+ $message_frag_lens);
+
+ return $self;
+}
+
+sub parse
+{
+ # We don't support parsing at the moment
+}
+
+# This is supposed to reconstruct the on-the-wire message data following changes.
+# For now though since we don't support parsing we just create an empty NextProto
+# message - this capability is used in test_npn
+sub set_message_contents
+{
+ my $self = shift;
+ my $data;
+
+ $data = pack("C32", 0x00, 0x1e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00);
+ $self->data($data);
+}
+1;
diff --git a/util/perl/TLSProxy/Proxy.pm b/util/perl/TLSProxy/Proxy.pm
index 3de10eccb9..b707722b6b 100644
--- a/util/perl/TLSProxy/Proxy.pm
+++ b/util/perl/TLSProxy/Proxy.pm
@@ -23,6 +23,7 @@ use TLSProxy::CertificateRequest;
use TLSProxy::CertificateVerify;
use TLSProxy::ServerKeyExchange;
use TLSProxy::NewSessionTicket;
+use TLSProxy::NextProto;
my $have_IPv6;
my $IP_factory;
--
2.46.0