using System;

public class Program

{

    public static Random RandomGenerator = new Random();

    public static void Main()

    {

        Console.WriteLine("Hello World");

        var user = "marco";

        var ts = DateTime.UtcNow.Ticks;

        var rand = RandomGenerator.Next();

        var token = user+"|||"+ts+"|||"+rand+"|||";

        var encToken = "xxxxgeneratodadfen";

        //encToken = CriptaCDfEncript(token);

        encToken = EncodeToBase64(encToken);

        Console.WriteLine(token+"==>"+"infermerie.aspx?tk="+encToken);

        //decript

        CheckLogin();       

    }

 static public void CheckLogin(){

     try{

 //var tk = System.Web.HttpContext.Request.QueryString["tk"];

     //decripto

         var tk="marco|||"+DateTime.UtcNow.AddSeconds(-9).Ticks+"|||795412637|||";

         var dt = long.Parse(tk.Split(new string[]{"|||"}, StringSplitOptions.None )[1]);

         Console.WriteLine((DateTime.UtcNow.Ticks - dt));

         if(DateTime.UtcNow.Ticks - dt > 100000000) // 10 secondi

             throw new Exception("token expired");

     }catch(Exception er){

        throw new Exception("access denied: "+er.Message);

     }

 }

         static public string EncodeToBase64(string toEncode)

        {

            byte[] toEncodeAsBytes = System.Text.ASCIIEncoding.ASCII.GetBytes(toEncode);

            string returnValue = System.Convert.ToBase64String(toEncodeAsBytes);

            return returnValue;

​

        }

​

        static public string DecodeFromBase64(string encodedData)

        {

            byte[] encodedDataAsBytes  = System.Convert.FromBase64String(encodedData);

            string returnValue =  System.Text.ASCIIEncoding.ASCII.GetString(encodedDataAsBytes);

            return returnValue;

        }

}