Tuesday, March 28, 2023

A simple role-based access control system for .NET

In many cases, I need a simple solution for adding authentication and authorization in my .NET project, so as to easily develop the rest of the system. I need something simple, e.g., hardcode some user information in the configuration file. ASP.NET Identity is for most of the times an overkill. So I decided to create my own solution. You can find the source code of my solution in this GitHub repository

The most important part is in the appsettings.Development.json file where users, their passwords, and their roles are defined. For example:

  "AuthorizedUsers": {
    "administrator": {
      "Password": "admin!",
      "Roles": [ "Administrator" ]
    "user1": {
      "Password": "user1!",
      "Roles": [ "User" ]

Then, in the Program.cs file the following code must be added:

    .AddCookie(options =>
        options.LoginPath = "/Account/Login";


builder.Services.AddAuthorization(options =>
    options.FallbackPolicy = new AuthorizationPolicyBuilder()

User authentication is handled by the Account controller. By default all pages are accessed only by authenticated users. If you want to restrict a page to particular role a decorator can be added to the corresponding controller method, e.g.:

[Authorize(Roles = "Administrator")]
public IActionResult Admin()
   return View();

I hope you can find this code useful