MyController.cs

[RequireScheme(Scheme.Http)]
public partial class MyController : Controller
{
    public virtual ActionResult AllowsHttpOnly()
    {
        return View();
    }

    [RequireScheme(Scheme.Https)]
    public virtual ActionResult AllowsHttpsOnly()
    {
        return View();
    }

    [RequireScheme(Scheme.Ignore)]
    public virtual ActionResult AllowsHttpOrHttps()
    {
        return View();
    }
}

RequireScheme.cs

public enum Scheme
{
    Ignore,
    Http,
    Https,
}

[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, Inherited = true, AllowMultiple = false)]
public class RequireScheme: FilterAttribute, IAuthorizationFilter
{
    private readonly Scheme scheme;

    public RequireScheme(Scheme scheme)
    {
        this.scheme = scheme;
    }

    public void OnAuthorization(AuthorizationContext filterContext)
    {
        if ((scheme == Scheme.Https) && !filterContext.HttpContext.Request.IsSecureConnection)
            filterContext.Result = GetResult(filterContext, "https");
        else if ((scheme == Scheme.Http) && filterContext.HttpContext.Request.IsSecureConnection)
            filterContext.Result = GetResult(filterContext, "http");
    }

    private static RedirectResult GetResult(AuthorizationContext filterContext, string scheme)
    {
        var builder = new UriBuilder()
        {
            Scheme = scheme,
            Host = filterContext.HttpContext.Request.Url.Host,
            Path = filterContext.HttpContext.Request.RawUrl
        };

        return new RedirectResult(builder.ToString());
    }
}