c# - .NET Core API Conditional Authentication attributes for Development & Production

Question

Long story short, Is it possible to place an environment based authorization attribute on my API so that the authorization restriction would be turned off in development and turned back on in Production?

I have a separate Angular 2 project that I wish to call a .NET Core API with. We created a separate project so we could open the Angular 2 project in vscode and debug the typescript. When we are finished, we will build the project and place it inside the .NET Core project for security reasons.

Our problem is that during the debugging stages, we are unable to connect to the API because they are two separate projects and our Angular 2 project does not have Active Directory. The .NET Core project currently has Authentication Attributes and wont allow access (401) to the API. It would be nice if we could turn that off during development and back on during production.

I'm also open to any other suggestions on how we can best solve this problem.

[Authorize: (Only in Production)] <-- // something like this???
[Route("api/[controller]")]
public class TestController : Controller
{
    ...

Answer 1

ASP.NET Core authorization is based on policies. As you may have seen, the AuthorizeAttribute can take a policy name so it knows which criteria need to be satisfied for the request to be authorized. I suggest that you have a read of the great documentation on that subject.

Back to your problem, it looks like you don't use a specific policy, so it uses the default one, which requires the user to be authenticated by default.

You can change that behaviour in Startup.cs. If you're in development mode, you can redefine the default policy so that it doesn't have any requirements:

public void ConfigureServices(IServiceCollection services)
{
    services.AddAuthorization(x =>
    {
        // _env is of type IHostingEnvironment, which you can inject in
        // the ctor of Startup
        if (_env.IsDevelopment())
        {
            x.DefaultPolicy = new AuthorizationPolicyBuilder().Build();
        }
    });
}

---

Update

im1dermike mentioned in a comment that an AuthorizationPolicy needs at least one requirement, as we can see here. That code wasn't introduced recently, so it means the solution above was broken the whole time.

To work around this, we can still leverage the RequireAssertion method of AuthorizationPolicyBuilder and add a dummy requirement. This would look like:

public void ConfigureServices(IServiceCollection services)
{
    services.AddAuthorization(x =>
    {
        // _env is of type IHostingEnvironment, which you can inject in
        // the ctor of Startup
        if (_env.IsDevelopment())
        {
            x.DefaultPolicy = new AuthorizationPolicyBuilder()
                .RequireAssertion(_ => true)
                .Build();
        }
    });
}

This ensures we have at least one requirement in the authorization policy, and we know that it will always pass.