C#字符串加密和解密

using System.Security.Cryptography;using System.IO;//默认密钥向量        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>        /// <param name="encryptKey">加密密钥,要求为8位</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 EncryptDES(string encryptString, string encryptKey)        {            try            {                byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));//转换为字节                byte[] rgbIV = Keys;                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);                DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();//实例化数据加密标准                MemoryStream mStream = new MemoryStream();//实例化内存流                //将数据流链接到加密转换的流                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>        /// <param name="decryptKey">解密密钥,要求为8位,和加密密钥相同</param>        /// <returns>解密成功返回解密后的字符串，失败返源串</returns>        public static string DecryptDES(string decryptString, string decryptKey)        {            try            {                byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey);                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;            }        }            string EncryptStr = EncryptDESString.EncryptDES("aaaaaaaaaa", "ssssssss");  //返回加密后的字符串            string DecryptStr = EncryptDESString.DecryptDES(EncryptStr, "ssssssss");//解密字符串