【加密技术】对称加密算法(2)：3DES

3DES 的实现方式：jdk 的实现 ， BouncyCastle 的实现方式 

   /**
 * jdk 3DES 生成秘钥
 * @return
 * @throws Exception
 */
public static byte [] JDK_3DES_GetSecretKey() throws Exception{
    KeyGenerator keyGenerator = KeyGenerator.getInstance("DESede");
    keyGenerator.init(168);  // 秘钥的长度 ,可使用 new SecureRandom() 生成默认长度的秘钥
    SecretKey secretKey = keyGenerator.generateKey();
    return secretKey.getEncoded();
}

/**
 * 使用 3des 对数据进行加密
 * @param src
 * @param encryptKey
 * @return
 * @throws Exception
 */
public static byte [] JDK_3DES_Encrypt(String src,byte [] encryptKey) throws Exception{
    //Key 的转换
    DESedeKeySpec keySpec = new DESedeKeySpec(encryptKey);
    SecretKeyFactory factory = SecretKeyFactory.getInstance("DESede");
    Key secretKey = factory.generateSecret(keySpec);

    //加密
    Cipher cipher = Cipher.getInstance("DESede/ECB/PKCS5Padding");
    cipher.init(Cipher.ENCRYPT_MODE, secretKey);
    byte [] result = cipher.doFinal(src.getBytes());
    return result;
}

/**
 * 使用 3des 对数据进行解密
 * @param encryptBytes
 * @param encryptKey
 * @return
 * @throws Exception
 */
public static String JDK_3DES_Decrypt(byte [] encryptBytes ,byte [] encryptKey) throws Exception{
    //Key 的转换
    DESedeKeySpec keySpec = new DESedeKeySpec(encryptKey);
    SecretKeyFactory factory = SecretKeyFactory.getInstance("DESede");
    Key secretKey = factory.generateSecret(keySpec);

    //解密
    Cipher cipher = Cipher.getInstance("DESede/ECB/PKCS5Padding");
    cipher.init(Cipher.DECRYPT_MODE, secretKey);
    String result = new String(cipher.doFinal(encryptBytes));
    return result;
}

/**
 * bc 3DES 生成秘钥
 * @return
 * @throws Exception
 */
public static byte [] BC_3DES_GetSecretKey() throws Exception{
    Security.addProvider(new BouncyCastleProvider());
    KeyGenerator keyGenerator = KeyGenerator.getInstance("DESede","BC");
    keyGenerator.init(new SecureRandom());  // 秘钥的长度  new SecureRandom() 默认长度
    SecretKey secretKey = keyGenerator.generateKey();
    return secretKey.getEncoded();
}

/**
 * 使用 3des 对数据进行加密
 * @param src
 * @param encryptKey
 * @return
 * @throws Exception
 */
public static byte [] BC_3DES_Encrypt(String src,byte [] encryptKey) throws Exception{
    //Key 的转换
    DESedeKeySpec keySpec = new DESedeKeySpec(encryptKey);
    SecretKeyFactory factory = SecretKeyFactory.getInstance("DESede");
    Key secretKey = factory.generateSecret(keySpec);

    //加密
    Cipher cipher = Cipher.getInstance("DESede/ECB/PKCS5Padding");
    cipher.init(Cipher.ENCRYPT_MODE, secretKey);
    byte [] result = cipher.doFinal(src.getBytes());
    return result;
}

/**
 * 使用 3des 对数据进行解密
 * @param encryptBytes
 * @param encryptKey
 * @return
 * @throws Exception
 */
public static String BC_3DES_Decrypt(byte [] encryptBytes ,byte [] encryptKey) throws Exception{
    //Key 的转换
    DESedeKeySpec keySpec = new DESedeKeySpec(encryptKey);
    SecretKeyFactory factory = SecretKeyFactory.getInstance("DESede");
    Key secretKey = factory.generateSecret(keySpec);

    //解密
    Cipher cipher = Cipher.getInstance("DESede/ECB/PKCS5Padding");
    cipher.init(Cipher.DECRYPT_MODE, secretKey);
    String result = new String(cipher.doFinal(encryptBytes));
    return result;
}