Probier mal aus

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using SteamKit2;
using System.IO;
using System.Threading;

namespace We_are_Coder
{
    class Program
    {
        static string user, pass;

        static SteamClient steamClient;
        static CallbackManager manager;
        static SteamUser steamUser;

        static bool isRunning = false;

        static string authCode;

        static void Main(string[] args)
        {
            Console.Title = "PowerByteDev";
            Console.WriteLine("CTRL+C quits the program");

            Console.Write("Username: ");
            user = Console.ReadLine();

            Console.Write("Password: ");
            pass = Console.ReadLine();

            SteamLogIn();
        }

        static void SteamLogIn()
        {
            steamClient = new SteamClient();

            manager = new CallbackManager(steamClient);

            steamUser = steamClient.GetHandler<SteamUser>();

            manager.Subscribe<SteamClient.ConnectedCallback>(OnConnected);

            manager.Subscribe<SteamUser.LoggedOnCallback>(OnLoggedOn);

            manager.Subscribe<SteamClient.DisconnectedCallback>(OnDisconnected);

            manager.Subscribe<SteamUser.UpdateMachineAuthCallback>(UpdateMachineAuthCallback);

            steamClient.Connect();

            steamClient.Connect();

            isRunning = true;
            while (isRunning)
            {
                manager.RunWaitCallbacks(TimeSpan.FromSeconds(1));
            }
            Console.ReadKey();
        }
        static void OnConnected(SteamClient.ConnectedCallback callback)
        {
            if (callback.Result != EResult.OK)
            {
                Console.WriteLine("Unable to connect to Steam: {0}", callback.Result);
                isRunning = false;
                return;
            }

            Console.WriteLine("Connected to Steam. \nLogging in {0}...\n", user);

            byte[] sentryHash = null;

            if (File.Exists("sentry.bin"))
            {
                byte[] sentryFile = File.ReadAllBytes("sentry.bin");

                sentryHash = CryptoHelper.SHAHash(sentryFile);
            }

            steamUser.LogOn(new SteamUser.LogOnDetails
            {
                Username = user,
                Password = pass,

                AuthCode = authCode,
            });
        }

        static void OnLoggedOn(SteamUser.LoggedOnCallback callback)
        {
            if (callback.Result == EResult.AccountLogonDenied)
            {
                Console.WriteLine("This account is SteamGuard protected.");

                Console.Write("Please enter the auth code sent to the email at {0}", callback.EmailDomain);

                authCode = Console.ReadLine();

                return;
            }
            if (callback.Result != EResult.OK)
            {
                Console.WriteLine("Unable to log in to Steam: {0}\n", callback.Result);
                isRunning = false;
                return;
            }
            Console.WriteLine("{0} successfully Logged in!", user);
        }

        static void UpdateMachineAuthCallback(SteamUser.UpdateMachineAuthCallback callback)
        {
            Console.WriteLine("Updating sentry file...");
            byte[] sentryHash = CryptoHelper.SHAHash(callback.Data);
            File.WriteAllBytes("sentry.bin", callback.Data);
            steamUser.SendMachineAuthResponse(new SteamUser.MachineAuthDetails
            {
                JobID = callback.JobID,
                FileName = callback.FileName,
                BytesWritten = callback.BytesToWrite,
                FileSize = callback.Data.Length,
                Offset = callback.Offset,
                Result = EResult.OK,
                LastError = 0,
                OneTimePassword = callback.OneTimePassword,
                SentryFileHash = sentryHash,
            });
            Console.WriteLine("Done!");
        }

        static void OnDisconnected(SteamClient.DisconnectedCallback callback)
        {
            Console.WriteLine("\n{0} disconnected from steam reconnecting in 5...\n", user);

            Thread.Sleep(TimeSpan.FromSeconds(5));

            steamClient.Connect();
        }
    }
}