ASP.NET core, change default redirect for unauthorized

Question

I am attempting to redirect to a different login url in ASP.NET MVC6

My account controller login method has a Route attribute to change the url.

Answer 1

Since asp.net core 2.0 if you use cookies without Identity:

app.UseAuthentication();

// If you don't want the cookie to be automatically authenticated and assigned HttpContext.User, 
// remove the CookieAuthenticationDefaults.AuthenticationScheme parameter passed to AddAuthentication.
services.AddAuthentication(CookieAuthenticationDefaults.AuthenticationScheme)
    .AddCookie(options => 
    {
        options.LoginPath = "/Account/LogIn";
        options.LogoutPath = "/Account/LogOff";
    });

source

Answer 2

I wouldn't recommend Serj Sagan solution in a real life example. This would work perfectly when developing but for a real application used by different types of user that might be misleading. Lets look at the below scenario

1. I am authenticated used
2. I know the url for a specific page
3. I am not authorize to access that pages

It means that I would be redirected to the login page as if I were not authenticated which is not the case. I would go more with mxmissile solution

Personnally I am using the AddMvcCore but you need to add AddRazorViewEngine if you are using razor views and AddRazorPages if you are using razor pages

        services.AddMvcCore(options =>
        {
            var policy = new AuthorizationPolicyBuilder()
                .RequireAuthenticatedUser()
                .Build();
            options.Filters.Add(new AuthorizeFilter(policy));
        })
        .AddRazorViewEngine()
        .AddAuthorization()
        .AddJsonFormatters();

Answer 3

With asp.net core 2.0 out now, this has changed to:

services.ConfigureApplicationCookie(options => options.LoginPath = "/Account/LogIn");

More on migrating to 2.0 here. And even more information on migrating from 2.0 to 2.1.

Answer 4

You'll need to configure this in startup.cs when adding the authentication service especially if you're using cookie authentication scheme.

services.AddAuthentication(CookieAuthenticationDefaults.AuthenticationScheme)
        .AddCookie(options => 
        {
            options.LoginPath = new PathString("/login");
        }); 

This was how i solved the issue, you'll should try it out...It'll definitely work for you

Answer 5

You may also want to try using StatusCodePages:

app.UseStatusCodePages(async context => {
    var response = context.HttpContext.Response;

    if (response.StatusCode == (int)HttpStatusCode.Unauthorized || 
        response.StatusCode == (int)HttpStatusCode.Forbidden)
        response.Redirect("/Error/Unauthorized");
});

Answer 6

UPDATE: As of dot net core 2.1.x, Identity is scaffolded from the SDK. To co--sign @mxmissile answer, the path can be specified. To pull off a trick path, combine with advanced routing or redirects.Scaffold Identity