Around 2.5 years back I had written about custom authorization on MVC Custom authorization on class, action/function, code, area level under Asp.Net MVC application , there are few approaches which are changed in Core version for authorization. Like Authorization filter approach is discouraged since it cannot be unit tested. I believe this is right step but also global or basic authentication could still be driven by Attribute due to enhancing simplicity on codes by focusing on the primary objective rather than writing authorization check everywhere. The whole approach and usage remain same from the original Post, in this, we would be just looking into making it compatible with dotnet Core MVC. You would need to go through earlier Post to understand the approach that was taken for authorization of a user. Also, can go through official post: https://docs.microsoft.com/en-us/aspnet/core/security/authorization/policies to understand new approach. More of all we need to create...