Introduction to authorization in ASP.NET Core

Authorization refers to the process that determines what a user is able to do. For example, an administrative user is allowed to create a document library, add documents, edit documents, and delete them. A non-administrative user working with the library is only authorized to read the documents.

Authorization is orthogonal and independent from authentication. However, authorization requires an authentication mechanism. Authentication is the process of ascertaining who a user is. Authentication may create one or more identities for the current user.

Authorization types

ASP.NET Core authorization provides a simple, declarative role and a rich policy-based model. Authorization is expressed in requirements, and handlers evaluate a user's claims against requirements. Imperative checks can be based on simple policies or policies which evaluate both the user identity and properties of the resource that the user is attempting to access.


Authorization components, including the AuthorizeAttribute and AllowAnonymousAttribute attributes, are found in the Microsoft.AspNetCore.Authorization namespace.

Consult the documentation on simple authorization.