.net core - How to return 403 on AuthorizationHandler? - api

Question

I implemented my custom AuthorizationHandler.
On that i check i the user can resolved and is active.
If the user isn't active then i would like to return an 403 status.
protected override async Task HandleRequirementAsync(AuthorizationHandlerContext context, ValidUserRequirement requirement)
{
var userId = context.User.FindFirstValue( ClaimTypes.NameIdentifier );
if (userId != null)
{
var user = await _userManager.GetUserAsync(userId);
if (user != null)
{
_httpContextAccessor.HttpContext.AddCurrentUser(user);
if (user.Active)
{
context.Succeed(requirement);
return;
}
else
{
_log.LogWarning(string.Format("User ´{1}´ with id: ´{0} isn't active", userId, user.UserName), null);
}
}
else
{
_log.LogWarning(string.Format("Can't find user with id: ´{0}´", userId), null);
}
} else
{
_log.LogWarning(string.Format("Can't get user id from token"), null);
}
context.Fail();
var response = _httpContextAccessor.HttpContext.Response;
response.StatusCode = 403;
}
But i receive a 401. Can you please help me?

Answer 1

Could you check that on the end of your function? I'm using that in my custom middleware to rewrite status code to 401 in some cases but in your scenario should also work
var filterContext = context.Resource as AuthorizationFilterContext;
var response = filterContext?.HttpContext.Response;
response?.OnStarting(async () =>
{
filterContext.HttpContext.Response.StatusCode = 403;
//await response.Body.WriteAsync(message, 0, message.Length); only when you want to pass a message
});

Answer 2

According to the Single Responsibility Principle , we should not use the HandleRequirementAsync() method to redirect reponse , we should use middleware or Controller to do that instead . If you put the redirect logic in HandleRequirementAsync() , how about if you want to use it in View page ?
You can remove the redirection-related code to somewhere else (outside) , and now you inject an IAuthorizationService to authorize anything as you like , even a resource-based authorization :
public class YourController : Controller{
private readonly IAuthorizationService _authorizationService;
public YourController(IAuthorizationService authorizationService)
{
this._authorizationService = authorizationService;
}
[Authorize("YYY")]
public async Task<IActionResult> Index()
{
var resource /* = ... */ ;
var x = await this._authorizationService.AuthorizeAsync(User,resource , "UserNameActiveCheck");
if (x.Succeeded)
{
return View();
}
else {
return new StatusCodeResult(403);
}
}
}

Answer 3

in .NET core 6.0 you can use the Fail method
AuthorizationHandlerContext.Fail Method
protected override async Task HandleRequirementAsync(AuthorizationHandlerContext context, AppAuthorizationRequirement requirement)
{
context.Fail(); //Use this
}