Add test for missing CertificateStatus message

If the client sends a status_request extension in the ClientHello
and the server responds with a status_request extension in the
ServerHello then normally the server will also later send a
CertificateStatus message. However this message is *optional* even
if the extensions were sent. This adds a test to ensure that if
the extensions are sent then we can still omit the message.
Reviewed-by: NViktor Dukhovni <viktor@openssl.org>

test/recipes/70-test_sslcertstatus.t

+#!/usr/bin/perl
+# Written by Matt Caswell for the OpenSSL project.
+# ====================================================================
+# Copyright (c) 1998-2015 The OpenSSL Project.  All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+#
+# 3. All advertising materials mentioning features or use of this
+#    software must display the following acknowledgment:
+#    "This product includes software developed by the OpenSSL Project
+#    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+#
+# 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+#    endorse or promote products derived from this software without
+#    prior written permission. For written permission, please contact
+#    openssl-core@openssl.org.
+#
+# 5. Products derived from this software may not be called "OpenSSL"
+#    nor may "OpenSSL" appear in their names without prior written
+#    permission of the OpenSSL Project.
+#
+# 6. Redistributions of any form whatsoever must retain the following
+#    acknowledgment:
+#    "This product includes software developed by the OpenSSL Project
+#    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+#
+# THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+# EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+# ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+# STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+# OF THE POSSIBILITY OF SUCH DAMAGE.
+# ====================================================================
+#
+# This product includes cryptographic software written by Eric Young
+# (eay@cryptsoft.com).  This product includes software written by Tim
+# Hudson (tjh@cryptsoft.com).
+
+use strict;
+use OpenSSL::Test qw/:DEFAULT cmdstr top_file top_dir/;
+use TLSProxy::Proxy;
+
+my $test_name = "test_sslcertstatus";
+setup($test_name);
+
+plan skip_all => "$test_name can only be performed with OpenSSL configured shared"
+    unless (map { s/\R//; s/^SHARED_LIBS=\s*//; $_ }
+        grep { /^SHARED_LIBS=/ }
+        do { local @ARGV = ( top_file("Makefile") ); <> })[0] ne "";
+
+$ENV{OPENSSL_ENGINES} = top_dir("engines");
+$ENV{OPENSSL_ia32cap} = '~0x200000200000000';
+my $proxy = TLSProxy::Proxy->new(
+    \&certstatus_filter,
+    cmdstr(app(["openssl"])),
+    top_file("apps", "server.pem")
+);
+
+plan tests => 1;
+
+#Test 1: Sending a status_request extension in both ClientHello and ServerHello
+#but then omitting the CertificateStatus message is valid
+$proxy->clientflags("-status");
+$proxy->start();
+ok(TLSProxy::Message->success, "Missing CertificateStatus message");
+
+sub certstatus_filter
+{
+    my $proxy = shift;
+
+    # We're only interested in the initial ServerHello
+    if ($proxy->flight != 1) {
+        return;
+    }
+
+    foreach my $message (@{$proxy->message_list}) {
+        if ($message->mt == TLSProxy::Message::MT_SERVER_HELLO) {
+            #Add the status_request to the ServerHello even though we are not
+            #going to send a CertificateStatus message
+            $message->set_extension(TLSProxy::ClientHello::EXT_STATUS_REQUEST,
+                                    "");
+
+            $message->repack();
+        }
+    }
+}

util/TLSProxy/ClientHello.pm

@@ -58,6 +58,7 @@ package TLSProxy::ClientHello;
 use parent 'TLSProxy::Message';
 
 use constant {
+    EXT_STATUS_REQUEST => 5,
     EXT_ENCRYPT_THEN_MAC => 22,
     EXT_EXTENDED_MASTER_SECRET => 23,
     EXT_SESSION_TICKET => 35