OWIN Authentication in .NET Core

OWIN (Open Web Interface for .NET) is an interface between web servers and web applications that provides a unified way to handle HTTP-related functionalities such as authentication and authorization.

In .NET Core, OWIN middleware can be used to implement authentication.

To implement OWIN authentication in .NET Core, you’ll need to follow these steps:

1. Install the required packages – Microsoft.Owin and Microsoft.Owin.Security.
2. In the Configure method of the Startup.cs file, configure OWIN middleware using the app.UseAuthentication() and app.UseAuthorization() methods.
3. In the ConfigureServices method of the Startup.cs file, configure authentication using the AddAuthentication and AddOAuthBearer methods:

services.AddAuthentication(options =>
{
    options.DefaultAuthenticateScheme = "Bearer";
    options.DefaultChallengeScheme = "Bearer";
})
.AddOAuthBearer(options =>
{
    options.Authority = "https://example.com"; // URL of the token issuer
    options.Audience = "audience"; // intended audience for the token
});

4. Add the [Authorize] attribute to the controller or action methods that require authentication:

[Authorize]
public class SecureController : Controller
{
    // action methods
}

By following these steps, you can implement OWIN authentication in your .NET Core application.