ASP.NET Identity 2.1 Custom Database

This is a two post series. You can read the second post at ASPNET Identity Custom Database and OWIN.

I have to admit when I first took a deeper look at the ASP.NET’s Identity model in version 2.1 I was a bit overwhelmed. I was looking for a way to authenticate a user against an existing database using Forms authentication to create an authentication cookie after verifying the user’s credentials. Looking at the template ASP.NET Individual User Accounts I found that the SignInManager was responsible for creating the authentication cookie and so I started there.

I found that the SignInManager constructor required a UserManager which in turned required an implementation of IUserStore. And so I went in search of a way to implement my own UserStore by look at the Entity Framework User Store. When I saw the number of interfaces Entity Frame works UserStore implemented I froze. Would I know what to implement and how?

IUser<TKey>

So I took a few deep breaths and when went back to the SigninManager. I would start there and see what was need to implement it. Using the existing SigninManager as a reference, I found I need to have a IUser<TKey>. This is easy enough:

public class CustomUser : IUser<string>
{
    public string Id { get; set; }

    public string UserName { get; set; }
}

UserManager<TUser>

Next the SigninManager constructor takes a Usermanager. Again this was a fairly simple implementation:

public class CustomUserManager : UserManager<CustomUser>
{
    public CustomUserManager(IUserStore<CustomUser> store)
        : base(store)
    {
    }
}

SigninManager<TUser, TKey>

Now we have all the piece to be able to put together the SigninManager:

public class CustomSignInManager : SignInManager<CustomUser, string>
{
    public CustomSignInManager(CustomUserManager userManager, IAuthenticationManager authenticationManager)
        : base(userManager, authenticationManager)
    {
    }
}

IUserStore<TUser>

The astute reader will have notice that we missed the implementation of the IUserStore<TUser> for the CustomerUserManager. This again is a very quick implementation of a few CRUD operations (I have left some of the implementation blank and the others are not production ready):

public class CustomUserStore : IUserStore<CustomUser>
{
    private CustomDbContext database;

    public CustomUserStore()
    {
        this.database = new CustomDbContext();
    }

    public void Dispose()
    {
        this.database.Dispose();
    }

    public Task CreateAsync(CustomUser user)
    {
        // TODO
        throw new NotImplementedException();
    }

    public Task UpdateAsync(CustomUser user)
    {
        // TODO
        throw new NotImplementedException();
    }

    public Task DeleteAsync(CustomUser user)
    {
		// TODO
        throw new NotImplementedException();
    }

    public async Task<CustomUser> FindByIdAsync(string userId)
    {
        CustomUser user = await this.database.CustomUsers.Where(c => c.UserId == userId).FirstOrDefaultAsync();
        return user;
    }

    public async Task<CustomUser> FindByNameAsync(string userName)
    {
       CustomUser user = await this.database.CustomUsers.Where(c => c.UserName == userName).FirstOrDefaultAsync();
        return user;
    }
}

Next Steps

We have now implemented all the parts required to create a Custom SigninManager. The initial feeling of being overwhelmed with the number of interfaces to implement has gone away. It was actually quite simple to create all the pieces to create our own SigninManager. Stay tuned for the next blog post where I show how to hook it into the OWIN Middleware so we can use it to sign our user in and create our Authentication Cookie.