Modify CookieAuthenticationOptions LoginPath OnRedirectToReturnUrl Event

Question

I have the following setup in my MVC 6 ASP.NET 5 project:

Startup.cs in the Configure Method:

app.UseCookieAuthentication(options =>
{
    options.AuthenticationScheme = "Cookie";
    options.LoginPath = new PathString("/<TENANT>/account/signin/");
    options.AccessDeniedPath = new PathString("/<TENANT>/account/unauthorised/");
    options.AutomaticAuthenticate = true;
    options.AutomaticChallenge = true;
    options.Events = new CookieAuthenticationEvents
    {
        OnRedirectToReturnUrl = MyClass.RedirectToReturnUrlAsync
    };
});

Events class:

public static class MyClass
{
    public static async Task RedirectToReturnUrlAsync(CookieRedirectContext context)
    {
        context.Options.LoginPath = new PathString("/<HERE I PLAN TO PUT LOGIC TO FIGURE OUT TENANT FROM CONTEXT>/account/signin");
    }

}

Lets say a user goes to the following url:

http://localhost/mycompany/securecontroller/secureaction

I want the Cookie middleware to redirect the user to:

http://localhost/mycompany/account/signin

The problem is the code "MyClass.RedirectToReturnUrlAsync" never gets hit when a Redirect to Return Url happens, so I cannot find the opportunity to modify the LoginPath at runtime.

I suspect I have something wrong in my setup. Has anybody ever encountered this problem?

Hooroo

Answer 1

Ok, I think I figured it out. I was looking at the problem from the wrong angle (and after a getting some sleep!)

app.UseCookieAuthentication(options =>
{
    options.AuthenticationScheme = "Cookie";
    options.LoginPath = new PathString("/<TENANT>/account/signin/");
    options.AccessDeniedPath = new PathString("/<TENANT>/account/unauthorised/");
    options.AutomaticAuthenticate = true;
    options.AutomaticChallenge = true;
    options.Events = new MyCookieAuthenticationEvents();
});

The proper way to create your own custom Cookie Authentication Events would be to derive from the CookieAuthenticationEvents object and override the events you'd like to custom, something like this:

public class MyCookieAuthenticationEvents : CookieAuthenticationEvents
{
    public override Task RedirectToLogin(CookieRedirectContext context)
    {
        context.RedirectUri = <PUT LOGIC HERE TO REPLACE YOUR REDIRECT URI>
        return base.RedirectToLogin(context);
    }
}

I was also targeting the wrong Event in my previous attempt. In my case, the correct method to override was the "RedirectToLogin" method.

Hooroo