Customizing ASP.NET Identity, OWIN and Social provider logins - asp.net-mvc-5

Question

I am new to ASP.NET MVC 5 and OWIN.
I have upgraded my project to MVC 5 to implement the authentication and authorization of my project. Problem is that my project does not store the user data. When user logins in I ask a different system via a WCF service to tell me if the user is authenticated. So I do not have a database nor tables that the user is stored in.
But I want to add the ability to login via social providers using OWIN. For this I will add a local database table to store the social provider Id/Token
Looking around other have asked similar question but only when they want to change database type store... Whilst I actually don't store the data... Is it still possible to customize this with ASP.NET Identity and how would I do this?

Answer 1

I would recommend creating a custom IUserStore that connects to the wcf service.
http://www.asp.net/identity/overview/extensibility/overview-of-custom-storage-providers-for-aspnet-identity

Answer 2

If you don't want to implement your own IUserStore, you can still use the built in default EF based UserStore and just only use the external login apis. The database schema will have a bunch of columns that will always be null like PasswordHash etc, but the operations you care about would still work fine:
CreateAsync(TUser) - Create a user
AddLoginAsync(userId, UserLoginInfo) - Associate an external login
FindAsync(UserLoginInfo) - Return the user with the associated external login

Answer 3

I looked into the solutions suggested. I found that the method names of the interfaces to implement did not really fit and there where way too many methods as well.
I ended up only using the OWIN Context in AccountController to extract the LoginInfo with all the details I wanted. This way I did not have to implement any custom versions of IUserLoginStore etc...
I wanted the simplest solution to implement and therefore I ended up with:
1. Added StartupAuth class from template mvc project and configured different providers there
1. In AccountController: Extracted the claims from LoginInfo,
2. Stored OpenId in a table for lookup and then continued on as before.

Answer 4

You have to provide a UserStore and pass it to the UserManager, if you are already using entityframework in the default mvc5 project, you can write your CustomUserStore which inherits from Microsoft.AspNet.Identity.EntityFramework.UserStore and override the methods defined in Microsoft.AspNet.Identity.EntityFramework.IUserLoginStore:
public interface IUserLoginStore<TUser, in TKey> : IUserStore<TUser, TKey>, IDisposable where TUser : class, Microsoft.AspNet.Identity.IUser<TKey>
{
Task AddLoginAsync(TUser user, UserLoginInfo login);
Task<TUser> FindAsync(UserLoginInfo login);
Task<Collections.Generic.IList<UserLoginInfo>> GetLoginsAsync(TUser user);
Task RemoveLoginAsync(TUser user, UserLoginInfo login);
}
if you don't use entityframework, you have to provide your own way of accessing your database,by writing a UserStore which implements IUserStore, IUserLoginStore, IUserClaimStore, IUserRoleStore,IUserPasswordStore,IUserSecurityStampStore (depends on your need but at least IUserStore and IUserLoginStore as IUserStore is mandatory and IUserLoginStore is what you want to add)
all these interfaces are in Microsoft.AspNet.Identity namespace.
here how to implement a Custom MySQL ASP.NET Identity Storage Provider and
here how to use Dapper ORM instead of EntityFramwework.