using System;

public class Program

{

    public static void Main()

    {

        // Console.WriteLine("Hello World");

        string strTextBytes1 = "5IWE5KWW5I2E5IWI46WO46i55Ji245WE5Jy25YmE5I2H";

        string x = CrmDecryptAuthoriz(strTextBytes1);

        Console.WriteLine(x);

    }

     public static String CrmDecryptAuthoriz(String key)

        {

            //2.         

            byte[] plainTextBytes2 = System.Convert.FromBase64String(key);

            string strTextBytes2 = System.Text.Encoding.UTF8.GetString(plainTextBytes2);

​

            //1.

            byte[] plainTextBytes1 = GetBytes(strTextBytes2);

            string strTextBytes1 = System.Text.Encoding.UTF8.GetString(plainTextBytes1);

​

            return strTextBytes1;

        }

           public static byte[] GetBytes(string str)

        {

            byte[] bytes = new byte[str.Length * sizeof(char)];

            System.Buffer.BlockCopy(str.ToCharArray(), 0, bytes, 0, bytes.Length);

            return bytes;

        }

}