private static final String AES_DECRIPTING_ALGORITHM = "AES/CBC/PKCS5Padding";

    private static final String DES_DECRIPTING_ALGORITHM = "DESede/ECB/PKCS5Padding";

​

    private byte[] getSecretKey(String ltpa3DESKey, String ltpaPassword) throws Exception

    {

        MessageDigest md = MessageDigest.getInstance("SHA");    

        md.update(ltpaPassword.getBytes());

        byte[] hash3DES = new byte[24];

        System.arraycopy(md.digest(), 0, hash3DES, 0, 20);

        Arrays.fill(hash3DES, 20, 24, (byte) 0);

        final Cipher cipher = Cipher.getInstance(DES_DECRIPTING_ALGORITHM);        

        final KeySpec keySpec = new DESedeKeySpec(hash3DES);

        final Key secretKey = SecretKeyFactory.getInstance("DESede").generateSecret(keySpec);

        cipher.init(Cipher.DECRYPT_MODE, secretKey);

        byte[] secret = cipher.doFinal(Base64.decodeBase64(ltpa3DESKey.getBytes()));

        return secret;

    }

    private byte[] decrypt(byte[] token, byte[] key, String algorithm) throws Exception

    {

        SecretKey sKey = null;

​

        if (algorithm.indexOf("AES") != -1)

        {

            sKey = new SecretKeySpec(key, 0, 16, "AES");

        }

        else

        {

            DESedeKeySpec kSpec = new DESedeKeySpec(key);

            SecretKeyFactory kFact = SecretKeyFactory.getInstance("DESede");

            sKey = kFact.generateSecret(kSpec);

        }

        Cipher cipher = Cipher.getInstance(algorithm);

​

        if (algorithm.indexOf("ECB") == -1)

        {

            if (algorithm.indexOf("AES") != -1)

            {

                IvParameterSpec ivs16 = generateIvParameterSpec(key, 16);

                cipher.init(Cipher.DECRYPT_MODE, sKey, ivs16);

            }

            else

            {

                IvParameterSpec ivs8 = generateIvParameterSpec(key, 8);

                cipher.init(Cipher.DECRYPT_MODE, sKey, ivs8);

            }

        }

        else

        {

            cipher.init(Cipher.DECRYPT_MODE, sKey);

        }

        return cipher.doFinal(token);

    }

    private IvParameterSpec generateIvParameterSpec(byte key[], int size)

    {

        byte[] row = new byte[size];

        for (int i = 0; i < size; i++)

        {

            row[i] = key[i];

        }

        return new IvParameterSpec(row);

    }

// How to use it:

byte[] secretKey = getSecretKey(ltpa3DESKey, ltpaPassword);

byte[] ltpaTokenBytes = Base64.decodeBase64(ltpaToken.getBytes());

String token = new String(decrypt(ltpaTokenBytes, secretKey, DES_DECRIPTING_ALGORITHM));

// or

String token = new String(decrypt(ltpaTokenBytes, secretKey, AES_DECRIPTING_ALGORITHM));