环境

我的IIS托管一个具有WebService资源的WebApp。

• myWebService.asmx
• myWebService.svc

问题

同样的坏人，试图用他们的机器人阻止服务器访问公共资源。

应用解决方案

1. I构建筛选器：

   public class BadGuysFilter
   {
       private class BadGuy
       {
           public BadGuy()
           {
               Visits = 0;
               FirstSuspiciousVisit = DateTime.Now;
           }
           public int Visits;
           public DateTime FirstSuspiciousVisit;
       }
       private static volatile Dictionary<string, BadGuy> _blackList = new Dictionary<string, BadGuy>();
       private static int _visitsLimit = 10;
       private static int _minutsLimit = 10;
       private static int _removeFromBlackListMinutesLimit = 30;
       public static void Init(int visitsLimit = 10, int minutsLimit = 10, int removeFromBlackListMinutesLimit = 30)
       {
           _visitsLimit = visitsLimit;
           _minutsLimit = minutsLimit;
           _removeFromBlackListMinutesLimit = removeFromBlackListMinutesLimit;
       }
       public static bool IsBadGuy()
       {
           return IsBadGuy(HttpContext.Current.Request.UserHostAddress);
       }
       public static bool IsBadGuy(string ip)
       {
           if (HttpContext.Current.Request.IsAuthenticated /*|| HttpContext.Current.Request.HttpMethod.ToUpper() == "POST"*/)
               return false;
           if (_blackList.Keys.Any(k => k == ip))
           {
               _blackList[ip].Visits++;
               if (_blackList[ip].FirstSuspiciousVisit < DateTime.Now.AddMinutes(-_removeFromBlackListMinutesLimit))
                   _blackList.Remove(ip);
               else if (_blackList[ip].FirstSuspiciousVisit < DateTime.Now.AddMinutes(-_minutsLimit))
               {
                   _blackList[ip].Visits = 0;
                   _blackList[ip].FirstSuspiciousVisit = DateTime.Now;
               }
               else if (_blackList[ip].Visits > _visitsLimit)
               {
                   _blackList[ip].FirstSuspiciousVisit = DateTime.Now;
                   return true;
               }
           }
           else
               _blackList.Add(ip, new BadGuy());
           return false;
       }
       public static void Punish()
       {
           var res = HttpContext.Current.Response;
           res.Clear();
           res.StatusCode = 429;
           res.StatusDescription = "TOO MANY REQUESTS: Your application is sending too many simultaneous requests.";
           res.End();
       }
   }
   

2. 在Global.asax中使用筛选器

   void Application_BeginRequest(object sender, EventArgs e) {
       if(BadGuysFilter.IsBadGuy())
           BadGuysFilter.Punish();
       // do stuff //
   }
   void Application_EndRequest(object sender, EventArgs e) {
       var app = (HttpApplication)sender;
       if (app.Context.Response.StatusCode == 429) // "TOO MANY REQUESTS"
           return;
       // do stuff //
   }
   

问题

这是一个足够安全的解决方案吗？或者还有别的办法

伊迪丝："不要在资源本身进行阻塞。在更上游进行阻塞，例如在防火墙处。–Marc B"是的，你是对的。这是最终解决方案，但在应用之前，我需要中间解决方案来保护我的服务器。我忘了提这件事Artiom