private static final byte[] ZERO_IV = new byte[] {
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
    };


    public static byte[] calculateMacArcfourHMACMD5 ( int keyusage, Key key, byte[] data ) throws GeneralSecurityException {
        int ms_usage = mapArcfourMD5KeyUsage(keyusage);
        Mac mac = Mac.getInstance("HmacMD5");

        byte[] datab = data.getBytes(StandardCharsets.US_ASCII);
        byte[] javaMac = sun.security.krb5.internal.crypto.ArcFourHmac.calculateChecksum(keyb, usage, datab, 0, datab.length);
        byte[] mac = PacMac.calculateMacArcfourHMACMD5(usage, makeKey(keyb, 23), datab);
        checkBytes(javaMac, mac);
        checkBytes(Hex.decode(expect), javaMac);
        checkBytes(Hex.decode(expect), mac);
    }


    @Test