Insert a short pseudorandom delay before closing channel after any as…

…ymmetric decoding failure

opc-ua-stack/stack-server/src/main/java/org/eclipse/milo/opcua/stack/server/transport/uasc/UascServerAsymmetricHandler.java

@@ -17,6 +17,7 @@
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.Random;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 
@@ -296,7 +297,11 @@ private void onOpenSecureChannel(ChannelHandlerContext ctx, ByteBuf buffer) thro
                     } catch (MessageDecodeException e) {
                         logger.error("Error decoding asymmetric message", e);
 
-                        ctx.close();
+                        ctx.executor().schedule(
+                            () -> ctx.close(),
+                            new Random().nextInt(1000), TimeUnit.MILLISECONDS
+                        );
+
                         return;
                     }