+
+# Test 2-3: Sending a duplicate extension should fail.
+sub inject_duplicate_extension
+{
+ my ($proxy, $message_type) = @_;
+
+ foreach my $message (@{$proxy->message_list}) {
+ if ($message->mt == $message_type) {
+ my %extensions = %{$message->extension_data};
+ # Add a duplicate (unknown) extension.
+ $message->set_extension(TLSProxy::Message::EXT_DUPLICATE_EXTENSION, "");
+ $message->set_extension(TLSProxy::Message::EXT_DUPLICATE_EXTENSION, "");
+ $message->repack();
+ }
+ }
+}
+
+sub inject_duplicate_extension_clienthello
+{
+ my $proxy = shift;
+
+ # We're only interested in the initial ClientHello
+ if ($proxy->flight != 0) {
+ return;
+ }
+
+ inject_duplicate_extension($proxy, TLSProxy::Message::MT_CLIENT_HELLO);
+}
+
+sub inject_duplicate_extension_serverhello
+{
+ my $proxy = shift;
+
+ # We're only interested in the initial ServerHello
+ if ($proxy->flight != 1) {
+ return;
+ }
+
+ inject_duplicate_extension($proxy, TLSProxy::Message::MT_SERVER_HELLO);
+}
+
+$proxy->clear();
+$proxy->filter(\&inject_duplicate_extension_clienthello);
+$proxy->start();
+ok(TLSProxy::Message->fail(), "Duplicate ClientHello extension");
+
+$proxy->clear();
+$proxy->filter(\&inject_duplicate_extension_serverhello);
+$proxy->start();
+ok(TLSProxy::Message->fail(), "Duplicate ServerHello extension");
+