tls: return fixed ASCII characters "STARTTLS" as starttls verifier

As required by current draft.

Acked-by: Paul Millar
Target: master

Author: kofemann

oncrpc4j-core/src/main/java/org/dcache/oncrpc4j/rpc/RpcAuthTypeTls.java

@@ -20,6 +20,7 @@
 package org.dcache.oncrpc4j.rpc;
 
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import javax.security.auth.Subject;
 import org.dcache.oncrpc4j.xdr.XdrAble;
 import org.dcache.oncrpc4j.xdr.XdrDecodingStream;
@@ -32,7 +33,8 @@
  */
 public class RpcAuthTypeTls implements RpcAuth, XdrAble {
 
-    private final RpcAuthVerifier verifier = new RpcAuthVerifier(RpcAuthType.NONE, new byte[0]);
+    private final static byte[] STARTTLS = "STARTTLS".getBytes(StandardCharsets.US_ASCII);
+    private final RpcAuthVerifier verifier = new RpcAuthVerifier(RpcAuthType.NONE, STARTTLS);
 
     @Override
     public int type() {