MVC 5 IoC and Authentication

Question

I am just about to start on a project, where I will be using MVC5. But as I want to use IoC and later reuse my user tables, and add custom stuff to it, I am finding it very hard to see how I can use the new Identity framework that came with MVC5.

I am more and more looking towards basic forms auth. What are your solutions?

My needs:

• User repository/service must be injected
• User repository must reside in the DAL
• User repository must be able to support other technologies than EF
• Authentication with OpenID and OAuth must be somewhat easy to implement
• MUST BE SECURE
• Should be reusable in other projects, eg. WPF

I have been looking for a long time for an answer, but everything I see is hardcoded in the controller.

How are you solving this? Are you writing most from scratch, or can you bind into something that will scale to other .NET platforms as WCF and WPF?

The below code is taken directly from the AccountController in the default ASP.NET MVC 5 Template. The first thing it does is a Bastard Injection.

[Authorize]
public class AccountController : Controller
{
    public AccountController()
        : this(
            new UserManager<ApplicationUser>(
                new UserStore<ApplicationUser>(
                    new ApplicationDbContext())))
    {
    }

    public AccountController(UserManager<ApplicationUser> userManager)
    {
        UserManager = userManager;
    }
}

The accepted answer will go to the person, that shows me what they have done, that incorporates the above requirements

Answer 1

Since this is .NET, the standard approach to security is to authenticate at the application boundary, and convert the authentication information into an IPrincipal. MVC supports this out of the box.

If you need other information gained during authentication, you can gather that at in the Composition Root and use it to compose your services.

As an example, imagine that you need the authenticated user's email address in a lower layer. Any class that requires the user's email address can simply request it as a Concrete Dependency:

public class EmailThingy
{
    private readonly string userEmail;

    public EmailThingy(string userEmail)
    {
        if (userEmail == null)
            throw new ArgumentNullException("userEmail");

        this.userEmail = userEmail;
    }

    // other members go here...
}

In ASP.NET MVC, the Composition Root is IControllerFactory. IIRC, you can pull the authentication data from within the CreateController method and use it to compose your object graph.

These days, I use IPrincipal in the same way: I inject it as a dependency, instead of relying on the Thread.CurrentPrincipal Ambient Context, because it's easier to unit test when everything is consistently injected via Constructor Injection.