ASP.NET Core is a fresh start. For authentication it means out with the old Http Modules’ events and in with a pipeline of Middleware. Middleware are loosely coupled components that are run by calling each other in a pipeline. They can be combined in different way. It can be a simple single cookie middleware used with an authentication form. Or it can be a powerful mixed authentication setup with multiple external providers (Google, Facebook, SAML2).
This deep dive starts with a closer look on how middleware are configured and how they interact during authentication. There will then be a look at how to implement a simple authentication middleware, identifying the different parts and how they relate to the overall pipeline model.