using System;

using System.Text;

​

public static class Program

{

    public static void Main()

    {

        var token = "Q0EyX09JQVBJOkN6JXRFM1MlMkMlZmZRUVE=";

        Decode(token);

        string username = "CA2_OIAPI", password = "Cz%tE3S%2C%ffQQQ";   

        Encode(username, password);

    } 

    public static void Decode(string token)

    {

        var creds = Encoding.UTF8.GetString(Convert.FromBase64String(token)).Split(":");

        Console.WriteLine("Decoded credentials:");

        Console.WriteLine($"Username: {creds[0]}");

        Console.WriteLine($"Password: {creds[1]}");        

        Console.WriteLine();

​

    }

    public static void Encode(string username, string password)

    {

        var token = Convert.ToBase64String(Encoding.UTF8.GetBytes($"{username}:{password}"));

        Console.WriteLine("Encoded credentials:");

        Console.WriteLine(token);      

        Console.WriteLine();

    }

}