Get list of custom attributes for current action/controller in ASP.NET MVC

This seems to work... is there a better / more proper way in ASP.NET MVC 1?

if (filterContext.Controller.GetType().GetCustomAttributes(typeof(RequireHttpsAttribute), true).Length > 0)
    return;
string action = (string)filterContext.RouteData.Values["action"];
if (!string.IsNullOrEmpty(action) && filterContext.Controller.GetType().GetMethod(action).GetCustomAttributes(typeof(RequireHttpsAttribute), true).Length > 0)
    return;

Even better and more reliable* approach:

filterContext.ActionDescriptor.GetCustomAttributes(
    typeof(RequireHttpsAttribute), true).Count> 0

Though this might be MVC 3.0+ only.

Goldplated edition, works on MVC5, probably 4/3:

filterContext.HasMarkerAttribute<RequireHttpsAttribute>()

Uses this set of helper extensions:

public static class MarkerAttributeExtensions
{
    public static bool HasMarkerAttribute<T>(this AuthorizationContext that) {
        return that.Controller.HasMarkerAttribute<T>()
            || that.ActionDescriptor.HasMarkerAttribute<T>();
    }

    public static bool HasMarkerAttribute<T>(this ActionExecutingContext that) {
        return that.Controller.HasMarkerAttribute<T>()
            || that.ActionDescriptor.HasMarkerAttribute<T>();
    }

    public static bool HasMarkerAttribute<T>(this ControllerBase that) {
        return that.GetType().HasMarkerAttribute<T>();
    }

    public static bool HasMarkerAttribute<T>(this Type that) {
        return that.IsDefined(typeof(T), false);
    }

    public static IEnumerable<T> GetCustomAttributes<T>(this Type that) {
        return that.GetCustomAttributes(typeof(T), false).Cast<T>();
    }

    public static bool HasMarkerAttribute<T>(this ActionDescriptor that) {
        return that.IsDefined(typeof(T), false);
    }

    public static IEnumerable<T> GetCustomAttributes<T>(this ActionDescriptor that) {
        return that.GetCustomAttributes(typeof(T), false).Cast<T>();
    }
}

this worked for me in .NET Core 2.2:

var controllerActionDescriptor = actionContext.ActionDescriptor as ControllerActionDescriptor;

if (controllerActionDescriptor != null)
{
    // Check if the attribute exists on the action method
    if (controllerActionDescriptor.MethodInfo?.GetCustomAttributes(inherit: true)?.Any(a => a.GetType().Equals(typeof(CustomAttribute))) ?? false)
        return true;

    // Check if the attribute exists on the controller
    if (controllerActionDescriptor.ControllerTypeInfo?.GetCustomAttributes(typeof(CustomAttribute), true)?.Any() ?? false)
        return true;
}