ValidateGlobalAntiForgeryToken attribute (put it on controller, not separate actions)

ValidateGlobalAntiForgeryTokenAttribute.cs

[AttributeUsage(AttributeTargets.Class, AllowMultiple = false, Inherited = true)]
public class ValidateGlobalAntiForgeryTokenAttribute : FilterAttribute, IAuthorizationFilter
{
  private readonly ValidateAntiForgeryTokenAttribute validator;

  private readonly AcceptVerbsAttribute acceptedVerbs;

  public ValidateGlobalAntiForgeryTokenAttribute()
  {
    this.validator = new ValidateAntiForgeryTokenAttribute();
    this.acceptedVerbs = new AcceptVerbsAttribute(HttpVerbs.Post);
  }

  public void OnAuthorization(AuthorizationContext filterContext)
  {
    string httpMethodOverride = filterContext.HttpContext.Request.GetHttpMethodOverride();
    if (this.acceptedVerbs.Verbs.Contains(httpMethodOverride, StringComparer.OrdinalIgnoreCase))
    {
      this.validator.OnAuthorization(filterContext);
    }
  }
}