我如何编写一个ActionFilter来确保AntiForgeryTokens用于每个Post操作？

Question

我希望AntiForgeryTokens在每个HttpPost Action上使用ActionFilter,该ActionFilter位于ControllerBase每个其他控制器继承的控制器中.

我想通过创建一个ActionFilter来实现这一点,该ActionFilter从中继承ValidateAntiForgeryToken一个参数,该参数告诉它将HTTP谓词应用到哪个.然后,我想要应用该过滤器, ControllerBase以确保AntiForgeryToken在整个站点上检查每个POST操作.

我正在研究使用这个解决方案,但是

• AuthorizationContext Constructor (ControllerContext)是一个过时的构造函数,我不知道如何使用推荐的方法重建代码AuthorizationContext(ControllerContext controllerContext, ActionDescriptor actionDescriptor).

• 默认情况下它似乎不使用AntiForgeryToken,因为我收到以下错误:A required anti-forgery token was not supplied or was invalid每次发布后操作.

我应该如何重写ActionFilter以满足当前的非过时标准并在每个[HttpPost]动词上正确使用防伪标记？

我是否必须在每种形式中都包含一个防伪标记(我在想)？(而不是自动生成 - 不要笑,我很好奇) 更新:正如评论中指出的那样; 是的,这必须在每个表格中完成.

以下是我的ControllerBase中的代码供参考:

[UseAntiForgeryTokenOnPostByDefault]
public class ControllerBase : Controller 
{
    [AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
    public class BypassAntiForgeryTokenAttribute : ActionFilterAttribute
    {
    }

    [AttributeUsage(AttributeTargets.Class, AllowMultiple = false)]
    public class UseAntiForgeryTokenOnPostByDefault : ActionFilterAttribute
    {
        public override void OnActionExecuting(ActionExecutingContext filterContext)
        {
            if (ShouldValidateAntiForgeryTokenManually(filterContext))
            {
                var authorizationContext = new AuthorizationContext(filterContext.Controller.ControllerContext);

                //Use the authorization of the anti forgery token, 
                //which can't be inhereted from because it is sealed
                new ValidateAntiForgeryTokenAttribute().OnAuthorization(authorizationContext);
            }

            base.OnActionExecuting(filterContext);
        }

        /// <summary>
        /// We should validate the anti forgery token manually if the following criteria are met:
        /// 1. The http method must be POST
        /// 2. There is not an existing [ValidateAntiForgeryToken] attribute on the action
        /// 3. There is no [BypassAntiForgeryToken] attribute on the action
        /// </summary>
        private static bool ShouldValidateAntiForgeryTokenManually(ActionExecutingContext filterContext)
        {
            var httpMethod = filterContext.HttpContext.Request.HttpMethod;

            //1. The http method must be POST
            if (httpMethod != "POST") return false;

            // 2. There is not an existing anti forgery token attribute on the action
            var antiForgeryAttributes =
                filterContext.ActionDescriptor.GetCustomAttributes(typeof (ValidateAntiForgeryTokenAttribute), false);

            if (antiForgeryAttributes.Length > 0) return false;

            // 3. There is no [BypassAntiForgeryToken] attribute on the action
            var ignoreAntiForgeryAttributes =
                filterContext.ActionDescriptor.GetCustomAttributes(typeof (BypassAntiForgeryTokenAttribute), false);

            if (ignoreAntiForgeryAttributes.Length > 0) return false;

            return true;
        }
    }
}

Answer 1

我使用了以下方法:

public class SkipCSRFCheckAttribute : Attribute
{
}

public class AntiForgeryTokenFilter : IAuthorizationFilter
{
    public void OnAuthorization(AuthorizationContext filterContext)
    {
        if (IsHttpPostRequest(filterContext) && !SkipCsrfCheck(filterContext))
            AntiForgery.Validate();
    }

    private static bool IsHttpPostRequest(AuthorizationContext filterContext)
    {
        return filterContext.RequestContext.HttpContext.Request.HttpMethod == HttpMethod.Post.ToString();
    }

    private static bool SkipCsrfCheck(AuthorizationContext filterContext)
    {
        return filterContext.ActionDescriptor.GetCustomAttributes(typeof (SkipCSRFCheck), false).Any();
    }
}

这使我们能够使用SkipCSRFCheck属性逐个禁用它,然后在Application_Start中将其注册为全局过滤器:

GlobalFilters.Filters.Add(new AntiForgeryTokenFilter());

Answer 2

您不需要实例化任何AuthorizationContext或调用该OnAuthorization方法，只需：

if (ShouldValidateAntiForgeryTokenManually(filterContext))
{
    AntiForgery.Validate(filterContext.HttpContext, null);
}