MVC3 Custom AuthorizeAttribute : how to pass in an object from controller

I have an object that contains all login data, that's in my controller (it was programmed before switching to MVC3).

I'm trying to add authorization to the site, so so far I have:

public LoginObject MyLoginObject
{
   get;
   set;
}

[CustomAuthorization()]
public ActionResult Index()
{
 return View();
}

and

public class CustomAuthorization : AuthorizeAttribute
{
   protected override bool AuthorizeCore(HttpContextBase httpContext)
   {
    return true;
    //should be return myLoginObject.IsLoggedIn;
   }
}

Is there anyway to pass MyLoginObject into the AuthorizeAttribute class? If not could I at least pass in a boolean from the object that specifies if the user is authorized or not?

Edit: My solution based on Zonnenberg's advice.

public class LoginObject : IPrincipal // Now extends IPrincipal 
{
   ... //old code
   private class IdentityImpl : IIdentity
{
  public string AuthenticationType
  {
    get;
    set;
  }

  public bool IsAuthenticated
  {
    get;
    set;
  }

  public string Name
  {
    get;
    set;
  }
}

public IIdentity Identity
{
  get { return new IdentityImpl { AuthenticationType = "Custom Authentication", IsAuthenticated = this.IsLoggedIn, Name = this.Id}; }
}
}

Then I moved the instantiation of loginobject into CustomAuthorization

public override void OnAuthorization(AuthorizationContext filterContext)
{
  // ... Set up LoginObject
    filterContext.RequestContext.HttpContext.User = myLoginObject;

  base.OnAuthorization(filterContext);
}

So now logging in, is done inside the authorization, and I can call User to access the login from the controller.