}

        byte[] mac = PacMac.calculateMacArcfourHMACMD5(usage, makeKey(keybytes, 23), bytes);
        checkBytes(javaChecksum, mac);
        checkBytes(Hex.decode(expect), mac);
    }


    /**
     * @param keybytes
     * @return
     */
    private static KerberosKey makeKey ( byte[] keybytes, int etype ) {
        return new KerberosKey(null, keybytes, etype, 0);
    }

    /**
     * @return
     * @throws IOException
     */
    private int negotiateWrite ( CommonServerMessageBlockRequest req, boolean setmid ) throws IOException {
        if ( setmid ) {
            makeKey(req);
        }
        else {
            req.setMid(0);
            this.mid.set(1);
        }
        int n = req.encode(this.sbuf, 4);