using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Text.RegularExpressions;

using System.Threading.Tasks;

using System.Web;

using System.Security.Cryptography;

using System.IO;

using System.Net;

using System.Net.Mail;

​

public class Program

{

        public static readonly string DefaultDesKey = "Xx%#lA*1"; 

        public static readonly string DefaultDesIv = "Xx%#lA*1";

    public static void Main()

    {

        Console.WriteLine("Hello World");

        var test = DesDecryptSafe("I_7qt5o3zJAJr9XptNoJEw2",DefaultDesKey, DefaultDesIv);

​

        Console.WriteLine(test);

    }

        public static string DesDecryptSafe(string encryptedString, string key, string iv)

        {

            string result = string.Empty;

​

            try

            {

                byte[] btKey = Encoding.UTF8.GetBytes(key);

​

                byte[] btIV = Encoding.UTF8.GetBytes(iv);

​

                DESCryptoServiceProvider des = new DESCryptoServiceProvider();

​

                using (MemoryStream ms = new MemoryStream())

                {

                    byte[] inData = HttpServerUtility.UrlTokenDecode(encryptedString);

​

                    try

                    {

                        using (CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(btKey, btIV), CryptoStreamMode.Write))

                        {

                            cs.Write(inData, 0, inData.Length);

​

                            cs.FlushFinalBlock();

                        }

​

                        result = Encoding.UTF8.GetString(ms.ToArray());

                    }

                    catch

                    {

                        result = encryptedString;

                    }

                }

            }

            catch

            {

                result = "error";

            }

​

            return result;

        }

        public static string DesEncryptSafe(string sourceString, string key, string iv)

        {

            string result = string.Empty;

            try

            {

                byte[] btKey = Encoding.UTF8.GetBytes(key);

​

                byte[] btIV = Encoding.UTF8.GetBytes(iv);

​

                DESCryptoServiceProvider des = new DESCryptoServiceProvider();

​

                using (MemoryStream ms = new MemoryStream())

                {

                    byte[] inData = Encoding.UTF8.GetBytes(sourceString);

                    try

                    {

                        using (CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(btKey, btIV), CryptoStreamMode.Write))

                        {

                            cs.Write(inData, 0, inData.Length);

​

                            cs.FlushFinalBlock();

                        }

​

                        result = HttpServerUtility.UrlTokenEncode(ms.ToArray());

                    }

                    catch

                    {

                        result = sourceString;

                    }

                }

            }

            catch

            {

                result = "error";

            }

​

            return result;

        }

}