Add a test for CVE-2021-3449

We perform a reneg handshake, where the second ClientHello drops the
sig_algs extension. It must also contain cert_sig_algs for the test to
work.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>

1 files changed, 35 insertions, 1 deletions

diff --git a/test/recipes/70-test_renegotiation.t b/test/recipes/70-test_renegotiation.t
index 734f1cd21e..89cab85aa1 100644
--- a/test/recipes/70-test_renegotiation.t
+++ b/test/recipes/70-test_renegotiation.t
@@ -38,7 +38,7 @@ my $proxy = TLSProxy::Proxy->new(
 $proxy->clientflags("-no_tls1_3");
 $proxy->reneg(1);
 $proxy->start() or plan skip_all => "Unable to start up Proxy for tests";
-plan tests => 3;
+plan tests => 4;
 ok(TLSProxy::Message->success(), "Basic renegotiation");
 
 #Test 2: Client does not send the Reneg SCSV. Reneg should fail
@@ -77,6 +77,20 @@ SKIP: {
        "Check ClientHello version is the same");
 }
 
+SKIP: {
+    skip "TLSv1.2 disabled", 1
+        if disabled("tls1_2");
+
+    #Test 4: Test for CVE-2021-3449. client_sig_algs instead of sig_algs in
+    #        resumption ClientHello
+    $proxy->clear();
+    $proxy->filter(\&sigalgs_filter);
+    $proxy->clientflags("-tls1_2");
+    $proxy->reneg(1);
+    $proxy->start();
+    ok(TLSProxy::Message->fail(), "client_sig_algs instead of sig_algs");
+}
+
 sub reneg_filter
 {
     my $proxy = shift;
@@ -96,3 +110,23 @@ sub reneg_filter
         }
     }
 }
+
+sub sigalgs_filter
+{
+    my $proxy = shift;
+    my $cnt = 0;
+
+    # We're only interested in the second ClientHello message
+    foreach my $message (@{$proxy->message_list}) {
+        if ($message->mt == TLSProxy::Message::MT_CLIENT_HELLO) {
+            next if ($cnt++ == 0);
+
+            my $sigs = pack "C10", 0x00, 0x08,
+                            # rsa_pkcs_sha{256,384,512,1}
+                            0x04, 0x01,  0x05, 0x01,  0x06, 0x01,  0x02, 0x01;
+            $message->set_extension(TLSProxy::Message::EXT_SIG_ALGS_CERT, $sigs);
+            $message->delete_extension(TLSProxy::Message::EXT_SIG_ALGS);
+            $message->repack();
+        }
+    }
+}