分布式服务器框架之Servers.Core库实现 DES对称加密算法；SHA1信息摘要算法；MD5信息摘要算法

#region DES加密解密 
        /*
         * 概况：
         * DES加密算法现已经被破解，要使用也是用3DES加密算法
         */
        //用于对称算法的初始化向量(公钥)
        private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
        public static string KeyDES = "87654321";
        /*DES加密字符串
            encryptString:待加密的字符串
            encryptKey:加密密钥，要求为8位(8个字符)
         */
        public static string EncryptDES(string encryptString,string encryptKey)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0,8));
                byte[] rgbIV = Keys;
                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
                //des服务者
                DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
                //内存流
                MemoryStream mStream = new MemoryStream();
                //加密流
                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;
            }
        }
        /*DES解密
            decryptString: 待解密的字符串
            decryptKey   : 解密密钥,要求8位，要求和加密密钥相同
        */
        public static string DecryptDES(string decryptString,string decryptKey)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey.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;
            }
        }
        #endregion

 #region Sha1
        //Sha1加密
        public static string Sha1(this string value)
        {
            if (string.IsNullOrEmpty(value))
                return null;
            SHA1 sha1 = new SHA1CryptoServiceProvider();
            byte[] bytResult = sha1.ComputeHash(Encoding.Default.GetBytes(value));
            string strResult = BitConverter.ToString(bytResult);
            strResult = strResult.Replace("-", "");
            return strResult;
        }
        #endregion

        #region Md5
        //Md5算法
        public static string Md5(this string sDataIn)
        {
            MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
            byte[] bytValue, bytHash;
            bytValue = Encoding.UTF8.GetBytes(sDataIn);
            bytHash = md5.ComputeHash(bytValue);
            md5.Clear();
            string sTemp = "";
            for (int i = 0; i < bytHash.Length; ++i)
            {
                sTemp += bytHash[i].ToString("X").PadLeft(2, '0');
            }
            return sTemp.ToUpper();
        }
        /*Md5算法
         * value:原始字符串
         * Is16:是否16位密码
         */
        public static string Md5(this string value,bool Is16)
        {
            if (string.IsNullOrEmpty(value))
                return null;
            if (Is16)
            {
                //截取前16位数(这样出现Hash值冲突的概率增高了)
                return value.Md5().Substring(0, 16);
            }
            else 
            {
                return value.Md5();
            }
        }
        #endregion