Requiring HTTPS in ASP.NET MVC3

You can simply use RequireHttpsAttribute to your Action or Controller.

For Example:

[RequireHttps]
public ActionResult SignIn()
{
   return View();
}

More details at: http://weblogs.asp.net/dwahlin/archive/2009/08/25/requiring-ssl-for-asp-net-mvc-controllers.aspx, http://salvoz.com/blog/2009/04/25/partial-ssl-and-authorization-with-asp-net-mvc-revisited/