title: ASP.NET Core - Add role claim to User
body: <p>I've an ASP.NET Core (based on .NET Framework) using Windows Authentication. Point is, I need to add a role claim on that user and this role is stored in a distant database.</p>
  
  <p>I've read so much thing about OWIN/Cookie/UserManager/UserStore/Identity and so on that I'm lost.</p>
  
  <p>Question : How do I add a role claim for current user logged in (windows) for the whole application in the easiest way?</p>
  
  <p>What I need is to easily use <code>[Authorize(Role= "MyAddedRole")]</code> or <code>bool res = User.IsInRole("MyAddedRole")</code></p>
  
  <p>Thanks</p>