https://www.codeproject.com/Articles/36836/Forms-Authentication-and-Role-based-Authorization
Problem Space
Sad, but true, “Forms authentication in ASP.NET does not directly support role based authorization”. If you have ended up implementing Forms authentication along with configuring authorization rules for “users” and “roles” in the web.config, you are going to see the access rules working fine for “users”, but, not working at all for “roles”. You might have thought, there must be some way to specify user roles in the famous FormsAuthentication.RedirectFromLoginPage(), or, any other method. But, there isn't!
Background
This is really surprising because, in real life, most applications (if not all) actually require authorization of system resources based upon user roles, not user names. So, if you are going to use Forms authentication in your upcoming ASP.NET application, and you need to implement role based authorization in your system, you have a problem.
Wait, this is not entirely true, because of two reasons:
Reason 1: Since ASP.NET 2.0, we have Membership. It includes Membership (User) service, Role service, and Profile (User properties) service. And, using Membership, you can easily implement Role based authorization in your ASP.NET application.
Reason 2: Even if you don't use Membership, you can write some code to implement Role based authorization in Forms authentication. Basically, you need to create the authentication ticket yourself and push the user roles in the “UserData” property after authenticating the user. Also, you need to retrieve user roles from the same “UserData” property in the authentication ticket and set it in the current User property in the subsequent requests. This trick works, and many have done this already.
So, What is this Article About?
Well, this article assumes that you did use Forms authentication directly instead of ASP.NET Membership in your application for some good reasons. Consequently, you implemented Role based authorization as suggested by lots of articles on the web (like this one). But I tell you, you probably ended up doing an incorrect and incomplete implementation, and you might have problems in the near future.
This article is going to address the problems with the suggested implementation approaches, and provide you a correct, smart, and quick way of implementing Role based authorization in case you are not using ASP.NET Membership in your system. All you'll need is 5 minutes to implement this!
Please take a look at this article before you proceed, in case you are new to ASP.NET and wondering about Forms Authentication.