int ctxFlags = getContextFlags();
            if ( ctxFlags != 0 ) {
                fields.add(new DERTaggedObject(true, 1, new DERBitString(ctxFlags)));
            }
            byte[] mechanismToken = getMechanismToken();
            if ( mechanismToken != null ) {
                fields.add(new DERTaggedObject(true, 2, new DEROctetString(mechanismToken)));
            }
            byte[] mechanismListMIC = getMechanismListMIC();

        NegTokenInit negInit = new NegTokenInit(mechToken);
        byte[] krbToken = negInit.getMechanismToken();


        Path p = Files.createTempFile("fakeserver", ".keytab");
        try {
            Files.write(p, keyTab);
            KeyTab kt = KeyTab.getInstance(p.toFile());