Google 2 Step Authenticator - MVC 5.0 ASP.Net C#

Requirement :

Implement google 2 step authentication in any existing MVC C# Project.

Features :

Highly Secure
No need of internet to get OTP Code
No cost for OTP code unlike SMS
No need to wait long to get a code
Both IOS and Android are supported
Complete solution with source code available for download
30 Days cookie so no need to authenticate daily [Can be changed]
Easily add or edit private secure code in web config.
Enable 2 step feature from Web.config
The session cookie is Encrypted for security purpose

Source Code :

Download complete source code from my repository: https://github.com/haneefputtur/GauthenticatorMVC5

Steps :

Create a blank MVC Project
Install Google Authenticator from Nuget Package 3. Add New Controller and name as LoginController Copy Below Code to controller

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web;
using System.Web.Configuration;
using System.Web.Mvc;
using System.Web.Security;
using GAuthenticator.Models;
using Google.Authenticator;

namespace GAuthenticator.Controllers
{
    public class LoginController : Controller
    {
        // GET: Login
        public ActionResult Index()
        {
            return View();
        }
      
        public ActionResult Login()
        {
            return View();
        }
        [HttpPost]
        public ActionResult Login(LoginModel login)
        {
            string message = "";
            bool status = false;
            //check UserName and password form our database here
            string GAuthPrivKey = WebConfigurationManager.AppSettings["GAuthPrivateKey"];
            string UserUniqueKey = (login.UserName + GAuthPrivKey);
            if (login.UserName == "Admin" && login.Password == "12345") // Admin as user name and 12345 as Password
            {
                status = true;
                Session["UserName"] = login.UserName;

                if (WebConfigurationManager.AppSettings["GAuthEnable"].ToString() == "1")
                {
                    HttpCookie TwoFCookie = Request.Cookies["TwoFCookie"];
                    int k = 0;
                    if (TwoFCookie == null)
                    {
                        k = 1;
                    }
                    else
                    {

                        if (!string.IsNullOrEmpty(TwoFCookie.Values["UserCode"]))
                        {
                            string UserCodeE = TwoFCookie.Values["UserCode"].ToString();
                            string UserCodeD = Encoding.UTF8.GetString(MachineKey.Unprotect(Convert.FromBase64String(UserCodeE)));


                            if (UserUniqueKey == UserCodeD)
                            {
                                FormsAuthentication.SetAuthCookie(Session["Username"].ToString(), false);
                                ViewBag.Message = "Welcome to Mr. " + Session["Username"].ToString();
                                //return View("UserProfile");
                                return RedirectToAction("UserProfile");
                            }
                            else
                            {
                                k = 1;
                            }


                        }
                    }

                    if (k == 1)
                    {

                        message = "Two Factor Authentication Verification";

                        //Two Factor Authentication Setup
                        TwoFactorAuthenticator TwoFacAuth = new TwoFactorAuthenticator();

                        Session["UserUniqueKey"] = UserUniqueKey;
                        var setupInfo = TwoFacAuth.GenerateSetupCode("HaneefPuttur.com", login.UserName, UserUniqueKey, 300, 300);
                        ViewBag.BarcodeImageUrl = setupInfo.QrCodeSetupImageUrl;
                        ViewBag.SetupCode = setupInfo.ManualEntryKey;
                    }
                }
                else
                {
                    FormsAuthentication.SetAuthCookie(Session["Username"].ToString(), true);
                    ViewBag.Message = "Welcome to Mr. " + Session["Username"].ToString();
                    //       return View("UserProfile");
                    return RedirectToAction("UserProfile");
                }

            }

            else
            {
                message = "Please Enter the Valid Credential!";
            }
            ViewBag.Message = message;
            ViewBag.Status = status;
            return View();
        }
        [Authorize]
        public ActionResult UserProfile()
        {
            //if (Session["Username"] == null || Session["IsValidTwoFactorAuthentication"] == null || !(bool)Session["IsValidTwoFactorAuthentication"])
            //{
            //    return RedirectToAction("Login");
            //}
            ViewBag.Message = "Welcome to  " + Session["Username"].ToString();
            return View();
        }

        public ActionResult TwoFactorAuthenticate()
        {
            var token = Request["CodeDigit"];
            TwoFactorAuthenticator TwoFacAuth = new TwoFactorAuthenticator();
            string UserUniqueKey = Session["UserUniqueKey"].ToString();
            bool isValid = TwoFacAuth.ValidateTwoFactorPIN(UserUniqueKey, token);
            if (isValid)
            {
                HttpCookie TwoFCookie = new HttpCookie("TwoFCookie");
                string UserCode = Convert.ToBase64String(MachineKey.Protect(Encoding.UTF8.GetBytes(UserUniqueKey)));

                TwoFCookie.Values.Add("UserCode", UserCode);
                TwoFCookie.Expires = DateTime.Now.AddDays(30);
                Response.Cookies.Add(TwoFCookie);
                Session["IsValidTwoFactorAuthentication"] = true;
                return RedirectToAction("UserProfile", "Login");
            }
            return RedirectToAction("Login", "Login");
        }
        public ActionResult Logoff()
        {
            Session["UserName"] = null;
            FormsAuthentication.SignOut();
            FormsAuthentication.RedirectToLoginPage();
            return RedirectToAction("Login");
        }
    }
}

Create New Model called LoginModel

Add Below Code to the file

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace GAuthenticator.Models
{
    public class LoginModel
    {
        public string UserName { get; set; }
        public string Password { get; set; }
    }
}

Create View Login.cshtml and copy the code from this link : https://github.com/haneefputtur/GauthenticatorMVC5/blob/master/GAuthenticator/Views/Login/Login.cshtml