MVC 5 & ASP.NET Identity – Implementation Confusion

I'm creating a new web application that will be written using MVC 5 and Entity Framework Database First Approach. I would also like to use ASP.Net Identity to look after membership, authentication, authorisation etc.

I've read a good bit about the ASP.Net Identity on the web and how it works, however, I am still learning about this topic.

When I created my MVC 5 application in Visual Studio 2013 and looked at the Account Controller my first instinct was that I didn't like what I saw, i.e., a DbContext was being referenced named 'ApplicationDbContext'. The reason I didn't like this was because I prefer to keep my DbContext in the appropriate project within my solution, i.e., in my Model layer which adheres to the separation of concerns logic.

Also, the out of the box MVC 5 project uses Entity Framework Code First to create a default database and tables to store the Users, Roles etc.

Because I must use an existing database with an existing User table, this approach does not suit my needs.

I still want to use the latest ASP.Net Identity for my application as it looks to have many benefits, therefore, I found this article which stripped back alot of the Entity Framework code but still got OWIN powered authentication into an ASP.NET MVC.

http://www.khalidabuhakmeh.com/asp-net-mvc-5-authentication-breakdown-part-deux

Using the tutorial above, here is the HttpPost Login method for my Account Controller

    [HttpPost]
    [AllowAnonymous]
    public ActionResult Login(LoginViewModel model, string returnUrl)
    {
        if (ModelState.IsValid)
        {
            //Calling my own custom Account Service which validates users login details
            var user = _AccountService.VerifyPassword(model.UserName, model.Password, false);
            if (user)
            {
                var identity = new ClaimsIdentity(new[] { new Claim(ClaimTypes.Name, model.UserName), }, DefaultAuthenticationTypes.ApplicationCookie, ClaimTypes.Name, ClaimTypes.Role);

                //ToDo: Manually adding Role, but will pull from db later
                identity.AddClaim(new Claim(ClaimTypes.Role, "guest"));

                AuthenticationManager.SignIn(new AuthenticationProperties
                {
                    IsPersistent = model.RememberMe
                }, identity);

                return RedirectToAction("Index", "MyDashboard");
            }
            else
            {
                ModelState.AddModelError("", "Invalid username or password.");
            }
        }

        return View(model);
    }

In my previous MVC applications I usually rolled my own custom membership and when a User logged into the site and was authenticated, I would have stored the any additional user details such as userID, DOB etc in the UserData string of the FormsAuthenticationTicket.

As the code above does not use FormsAuthentication, instead it uses OWIN CookieAuthentication, I am not sure how to store this additional user data.

Therefore, I have a few questions about the problems I am experiencing.

1. How do I store the userID or any other additional piece of user data (DOB etc) the way I used to in FormsAuthentication? Is this done by adding a Claim to the identity?

2. Does the method of using ASP.Net Identity/ OWIN above seem correct considering I am using Entity Framework Database First with an existing database?

3. Should I be using the out of the box code that is used in the Account Controller, i.e., UserManager, ApplicationUser, ApplicationDbContext etc and hooking this up to work with my existing database?

I apologise if my question is confusing, I suppose I'm just a little unsure of what approach I should be using whilst attempting to use ASP.Net Identity in my latest project.

Any feedback would be greatly appreciated.

Thanks.