Url的DEC加密与解密

代码即注释，就不解释了

 public class PermissionHelper    {        ///<summary>        /// DEC 加密过程        /// </summary>        /// <param name="pToEncrypt">被加密的字符串</param>        /// <param name="sKey">密钥（只支持8个字节的密钥）</param>        /// <returns>加密后的字符串</returns>        public string Encrypt(string pToEncrypt, string sKey)        {            //访问数据加密标准(DES)算法的加密服务提供程序 (CSP) 版本的包装对象            DESCryptoServiceProvider des = new DESCryptoServiceProvider();            des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);　//建立加密对象的密钥和偏移量            des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);　 //原文使用ASCIIEncoding.ASCII方法的GetBytes方法            byte[] inputByteArray = Encoding.Default.GetBytes(pToEncrypt);//把字符串放到byte数组中            MemoryStream ms = new MemoryStream();//创建其支持存储区为内存的流　            //定义将数据流链接到加密转换的流            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);            cs.Write(inputByteArray, 0, inputByteArray.Length);            cs.FlushFinalBlock();            //上面已经完成了把加密后的结果放到内存中去            StringBuilder ret = new StringBuilder();            foreach (byte b in ms.ToArray())            {                ret.AppendFormat("{0:X2}", b);            }            ret.ToString();            return ret.ToString();        }        /// <summary>        /// DEC 解密过程        /// </summary>        /// <param name="pToDecrypt">被解密的字符串</param>        /// <param name="sKey">密钥（只支持8个字节的密钥，同前面的加密密钥相同）</param>        /// <returns>返回被解密的字符串</returns>        public string Decrypt(string pToDecrypt, string sKey)        {                             DESCryptoServiceProvider des = new DESCryptoServiceProvider();                byte[] inputByteArray = new byte[pToDecrypt.Length / 2];                for (int x = 0; x < pToDecrypt.Length / 2; x++)                {                    int i = (Convert.ToInt32(pToDecrypt.Substring(x * 2, 2), 16));                    inputByteArray[x] = (byte)i;                }                des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);　//建立加密对象的密钥和偏移量，此值重要，不能修改                des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);                MemoryStream ms = new MemoryStream();                CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);                cs.Write(inputByteArray, 0, inputByteArray.Length);                cs.FlushFinalBlock();                //建立StringBuild对象，createDecrypt使用的是流对象，必须把解密后的文本变成流对象                StringBuilder ret = new StringBuilder();                return System.Text.Encoding.Default.GetString(ms.ToArray());        }    }