ASP.NET Web API 2 access current user claims via dependency injection with Autofac

Question

At the moment I have to develop a self-hosted ASP.NET Web API 2 with Topshelf and Owin. I use Autofac as IOC container and an OAuth2 authentication with JWT tokens.

In .NET Core/.NET 5 web api's I can get DI access to the claims of the current user via IHttpContextAccessor.

How can I access the user claims via DI in my .NET Framework Web API using Autofac? (I don't want to access them in the API controller but in domain services).

Answer 1

While @Steven's suggestion will work fine with normal .NET Web API 2 applications, it is not suitable for self-hosted applications with Owin, since HttpContext.Current is always NULL there. Based on @Steven's suggested solution, I was able to solve the problem as follows:

Install the Nuget package OwinRequestScopeContext. Add app.UseRequestScopeContext(); to the Startup.cs. Add a IClaimsProvider interface to the Domain project:

public interface IClaimsProvider
    {
        ClaimsPrincipal UserClaims { get; }
    }

Add a OwinContextClaimsProvider class which implements IClaimsProvider to the startup project:

public class OwinContextClaimsProvider : IClaimsProvider
    {
        public ClaimsPrincipal UserClaims => OwinRequestScopeContext.Current.Environment["server.User"] as ClaimsPrincipal;
    }

Register the ClaimsProvider using Autofac:

builder.RegisterType<OwinContextClaimsProvider>().As<IClaimsProvider>().InstancePerLifetimeScope();

Note: IClaimsProvider.UserClaims will be NULL if no user is authenticated.