int ms_usage = mapArcfourMD5KeyUsage(keyusage);
        Mac mac = Mac.getInstance("HmacMD5");
        MessageDigest md = MessageDigest.getInstance("MD5");
        mac.init(key);
        byte[] dk = mac.doFinal(MD5_CONSTANT);
        try {
            // little endian
            md.update((byte) ( ms_usage & 0xFF ));

    private static void testJavaHMAC ( String key, byte[] bytes, String expect ) throws NoSuchAlgorithmException, InvalidKeyException {
        Mac m = Mac.getInstance("HmacMD5");
        m.init(new SecretKeySpec(Hex.decode(key), "HMAC"));
        byte[] mac = m.doFinal(bytes);
        checkBytes(Hex.decode(expect), mac);
    }


    @Test
    public void testRC4Checksum1 () throws PACDecodingException, GeneralSecurityException {

        Key macKey = new SecretKeySpec(key.clone(), KerberosConstants.HMAC_ALGORITHM);
        Mac mac = Mac.getInstance(KerberosConstants.HMAC_ALGORITHM);
        mac.init(macKey);
        return mac.doFinal(data);
    }


    public String getUserRealm () {
        return this.userRealm;
    }


    public String getUserPrincipalName () {

    /**
     * Retrieves the MAC address of the remote network interface. Samba returns all zeros.
     * 
     * @param tc
     *            context to use
     *
     * @return the MAC address as an array of six bytes
     * @throws UnknownHostException
     *             if the host cannot be resolved to
     *             determine the MAC address.
     */

 */
package jcifs.internal;


/**
 * @author mbechler
 *
 */
public interface SMBSigningDigest {

    /**
     * Performs MAC signing of the SMB. This is done as follows.
     * The signature field of the SMB is overwritten with the sequence number;
     * The MD5 digest of the MAC signing key + the entire SMB is taken;
     * The first 8 bytes of this are placed in the signature field.
     *
     * @param data

        hmac.update(serverChallenge);
        hmac.update(clientData, offset, length);
        byte[] mac = hmac.digest();
        byte[] ret = new byte[mac.length + clientData.length];
        System.arraycopy(mac, 0, ret, 0, mac.length);
        System.arraycopy(clientData, 0, ret, mac.length, clientData.length);
        return ret;
    }
    public static byte[] getLMv2Response(

        hmac.update(serverChallenge);
        hmac.update(clientData, offset, length);
        byte[] mac = hmac.digest();
        byte[] ret = new byte[mac.length + clientData.length];
        System.arraycopy(mac, 0, ret, 0, mac.length);
        System.arraycopy(clientData, 0, ret, mac.length, clientData.length);
        return ret;
    }


    /**
     * 
     * @param domain
     * @param username

     * signing/verifying SMB using kerberos session key.
     * The MAC Key = concat(Session Key, Digest of Challenge);
     * Because of Kerberos Authentication don't have challenge,
     * The MAC Key = Session Key
     * 
     * @param macSigningKey
     *            The MAC key used to sign or verify SMB.
     */
    public SMB1SigningDigest ( byte[] macSigningKey ) {

            log.flush();
        }
        updates = 0;

        return b;
    }

    /**
     * Performs MAC signing of the SMB.  This is done as follows.
     * The signature field of the SMB is overwritted with the sequence number;
     * The MD5 digest of the MAC signing key + the entire SMB is taken;
     * The first 8 bytes of this are placed in the signature field.
     *
     * @param data The data.

        }
        catch ( NoSuchAlgorithmException e ) {
            throw new CIFSUnsupportedCryptoException(e);
        }
    }


    /**
     * 
     * @param key
     * @return HMACT64 MAC
     */
    public static MessageDigest getHMACT64 ( byte[] key ) {
        return new HMACT64(key);
    }


    /**
     * 
     * @param key
     * @return RC4 cipher
     */