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.
@@ -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
@@ -78,6 +78,20 @@ 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;
@@ -97,3 +111,23 @@ 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();
+ }
+ }
+}
