/**
     * 
     */
    private static final String HMAC_KEY = "HMAC";
    private static final byte[] MD5_CONSTANT = "signaturekey\0".getBytes(StandardCharsets.US_ASCII);
    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 {

    /**
     * 
     */
    public static final int FSCTL_SRV_ENUMERATE_SNAPSHOTS = 0x00144064;
    /**
     * 
     */
    public static final int FSCTL_SRV_REQUEST_RESUME_KEY = 0x00140078;
    /**
     * 
     */
    public static final int FSCTL_SRV_READ_HASH = 0x001441bb;
    /**
     * 
     */
    public static final int FSCTL_SRV_COPYCHUNK_WRITE = 0x001480F2;
    /**

     */
    public static final int NTLMSSP_NEGOTIATE_DATAGRAM_STYLE = 0x00000040;

    /**
     * Indicates that the LAN Manager session key should be used for
     * signing and sealing authenticated communication.
     */
    public static final int NTLMSSP_NEGOTIATE_LM_KEY = 0x00000080;

    /**
     * ??? According to spec this is a reserved bit and must be set to zero
     */

                    HMACT64 hmac = new HMACT64(userSessionKey);
                    hmac.update(sessionNonce);
                    byte[] ntlm2SessionKey = hmac.digest();

                    if ((getFlags() & NTLMSSP_NEGOTIATE_KEY_EXCH) != 0) {
                        masterKey = new byte[16];
                        RANDOM.nextBytes(masterKey);

                        byte[] exchangedKey = new byte[16];

        }
        EXT_GSS_CONTEXT_CLASS = extendedGSSContextClassPrep;
        INQUIRE_SEC_CONTEXT = inquireSecContextPrep;
        INQUIRE_TYPE_SESSION_KEY = inquireTypeSessionKeyPrep;

        if ( EXT_GSS_CONTEXT_CLASS != null && INQUIRE_SEC_CONTEXT != null && INQUIRE_TYPE_SESSION_KEY != null ) {
            if ( log.isDebugEnabled() ) {
                log.debug("Found ExtendedGSSContext implementation: " + EXT_GSS_CONTEXT_CLASS.getName());

        if ( !auth.isAnonymous() ) {
            this.ntlmsspFlags |= NtlmFlags.NTLMSSP_NEGOTIATE_SIGN | NtlmFlags.NTLMSSP_NEGOTIATE_ALWAYS_SIGN | NtlmFlags.NTLMSSP_NEGOTIATE_KEY_EXCH;
        }
        else if ( auth.isGuest() ) {
            this.ntlmsspFlags |= NtlmFlags.NTLMSSP_NEGOTIATE_KEY_EXCH;
        }
        else {
            this.ntlmsspFlags |= NtlmFlags.NTLMSSP_NEGOTIATE_ANONYMOUS;
        }

    }


    /**
     * @param key
     *            7-byte "raw" DES key
     * @return 8-byte DES key with parity
     */
    static byte[] des7to8 ( byte[] key ) {
        byte key8[] = new byte[8];
        key8[ 0 ] = (byte) ( key[ 0 ] & 0xFE );
        key8[ 1 ] = (byte) ( ( key[ 0 ] << 7 ) | ( ( key[ 1 ] & 0xFF ) >>> 1 ) );
        key8[ 2 ] = (byte) ( ( key[ 1 ] << 6 ) | ( ( key[ 2 ] & 0xFF ) >>> 2 ) );

     * @param data
     * @param key
     * @throws GeneralSecurityException
     */
    private static void verifyAESMAC ( int usage, String expect, String data, String key ) throws GeneralSecurityException {
        verifyAESHMAC(usage, expect, key, Hex.decode(data));
    }


    private static void verifyArcfourHMAC ( int usage, String expect, String data, String key ) throws GeneralSecurityException {

    public static byte[] decrypt ( byte[] data, Key key, int type ) throws GeneralSecurityException {
        Cipher cipher = null;
        byte[] decrypt = null;

        switch ( type ) {
        case KerberosConstants.DES_ENC_TYPE:
            decrypt = decryptDES(data, key, cipher);
            break;
        case KerberosConstants.RC4_ENC_TYPE:
            decrypt = decryptRC4(data, key);
            break;
        default:

        Map map = new HashMap();
        String key = connection.getHeaderFieldKey(0);
        String value = connection.getHeaderField(0);
        for (int i = 1; key != null || value != null; i++) {
            List values = (List) map.get(key);
            if (values == null) {
                values = new ArrayList();
                map.put(key, values);
            }
            values.add(value);