DES如何解密

[malong60]

以下是加密代码，如何进行解密，求请教，没弄过，研究了几个钟没有头绪啊。
public static string EncryptDES(string message, string DES_KEY)
{
DES des = new DESCryptoServiceProvider();
des.Key = Encoding.UTF8.GetBytes(DES_KEY);
des.Mode = CipherMode.ECB;
byte[] bytes = Encoding.UTF8.GetBytes(message);
byte[] result = des.CreateEncryptor().TransformFinalBlock(bytes,0, bytes.Length);
SHA256 sha256 = new SHA256Managed();
byte[] buffer = sha256.ComputeHash(Encoding.ASCII.GetBytes(Convert.ToBase64String(result)));
StringBuilder sb = new StringBuilder();
foreach (byte by in buffer)
{
sb.AppendFormat("{0:x2}", by);
}
return sb.ToString();
}

[sky]

这是我自己用的一个DES加解密函数，供参考。

        //默认密钥向量 
        private static string DESKey = "abcd";
        private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };

        /// <summary> 
        /// DES加密字符串 
        /// </summary> 
        /// <param name="encryptString">待加密的字符串</param> 
        /// <returns>加密成功返回加密后的字符串，失败返回源串</returns> 
        public static string DESEncrypt(string encryptString)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(DESKey.Substring(0, 8));
                byte[] rgbIV = Keys;
                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);

                DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);

                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();

                return Convert.ToBase64String(mStream.ToArray());
            }
            catch
            {
                return encryptString;
            }
        }

        /// <summary> 
        /// DES解密字符串 
        /// </summary> 
        /// <param name="decryptString">待解密的字符串</param> 
        /// <returns>解密成功返回解密后的字符串，失败返源串</returns> 
        public static string DESDecrypt(string decryptString)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(DESKey);
                byte[] rgbIV = Keys;
                byte[] inputByteArray = Convert.FromBase64String(decryptString);

                DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);

                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();

                return Encoding.UTF8.GetString(mStream.ToArray());
            }
            catch
            {
                return decryptString;
            }
        }

[malong60]

[quote=引用 1 楼 pantian 的回复:] 这是我自己用的一个DES加解密函数，供参考。 你好，我现在是这样的，我是要按我上面那个加密方法加密成数据库指定的以前生成的密码加密的字符串，所以要按我上面那个解密才能解密出数据库指定的密码对应的数字