using System;

using System.IO;

using System.Security.Cryptography;

using System.Text;

​

public class Program

{

    public static void Main()

    {

        //Message Data value

        //We are using encrypted multibyte.

        string myData = @"ROE8oYeV7B6faUsvfIx0Xe55vSs9IR5DlWGRbSM+lmKmLcaJsA13VudwWlAEYtLUD8+nMXShky0grSxsk0Z9cQe5V45XnAIfUhnyzI9a0jtMFC8XnIZ5dbclPO/V73QnieIZDkbNV5cPo3BM+l79ai96KB/gkF3xuerFPxvWejtPyWbOyO+FfNyFps4gAYDITsYIAEH39VP4eipmQ5zc18BA39lajQ3UaVewSxz7H+x3Ooe2SzJT/TQWRkioJSEFwexqzkHiLOQ0MOCIVD9xTWpLYnsL3LMwyF6H8f0PY4Fc57LVGhvUZ7dsB9NWUAnmG3uqbsonNFVhuXyvJTWNyFOHwFzOMx6XDLJJFHGZhaHg2VrescfnpUtonQY08RgojBngyJNRqK8URAvI3bqKq8Y7F/9HmEtMIIQe6KuuTmU=";

        string myKey = "012345678901234567890123456789";//Development Env Key.

        //string myKey = "012345678901234567890123";//Development Env Key.

        Console.WriteLine("Decrypt1:");

        string s = Decrypt1(myData, myKey);

        Console.WriteLine("Decrypted:" + s);

        Console.ReadLine();

    }

​

    public static string Decrypt1(string value, string decryptionKey)

    {

        string decryptString = "";

        TripleDESCryptoServiceProvider tDESalg = new TripleDESCryptoServiceProvider();

        MD5CryptoServiceProvider hashMD5Provider = new MD5CryptoServiceProvider();

        try

        {

            byte[] decodedData = Convert.FromBase64String(value);

            tDESalg.Mode = CipherMode.ECB;

            tDESalg.Padding = PaddingMode.PKCS7;//According to MS, same as PKCS5PADDING

            //byte[] Key = hashMD5Provider.ComputeHash(Encoding.UTF8.GetBytes(decryptionKey));//BAD

            byte[] Key = Encoding.UTF8.GetBytes(decryptionKey.Substring(0,24));

            Console.WriteLine("key len: " + Key.Length.ToString());

            //byte[] IV = tDESalg.IV;

            byte[] IV = new byte[tDESalg.BlockSize / 8]; //The size of the IV property must be the same as the BlockSize property divided by 8

            var memoryStream = new MemoryStream(decodedData);

            var cryptoStream = new CryptoStream(memoryStream, tDESalg.CreateDecryptor(Key, IV), CryptoStreamMode.Read);

            var reader = new StreamReader(cryptoStream);

            decryptString = reader.ReadToEnd();

            byte[] decryptData = Convert.FromBase64String(decryptString);

            decryptString = System.Text.UTF8Encoding.UTF8.GetString(decryptData);

            //decryptString = BitConverter.ToString(decryptData);

        }

        catch (Exception e)

        {

            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message + e.StackTrace);

            return null;

        }

​

        return decryptString;

    }

}