/// <summary>    /// 加密、解密    /// </summary>    public class CryptoSecurity    {        /// <summary>        /// 默认密钥向量        /// </summary>        private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };        private static string encryptKey = DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + DateTime.Now.Day.ToString() + "1qasde32";        /// <summary>        /// DES加密字符串(权限代码加密、页面数据访问的加密)        /// </summary>        /// <param name="encryptString">待加密的字符串</param>        /// <returns></returns>        public static string EncryptDES(string encryptString)        {            try            {                byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.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  (权限代码解密、页面数据访问的解密)        /// </summary>        /// <param name="decryptString">待解密的字符串</param>        /// <returns></returns>        public static string DecryptDES(string decryptString)        {            try            {                byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));                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;            }        }    }