使用Global.asax的Application_BeginRequest事件过滤客户端XSS恶意脚本提交

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Web;
 5 using System.Text.RegularExpressions;
 6 
 7 /// <summary>
 8 ///XSSFilter 的摘要说明
 9 /// </summary>
10 public class XSSFilter
11 {
12     public XSSFilter() { }
13 
14     private const string StrRegex = @"<[^>]+?style=[\w]+?:expression\(|\b(alert|confirm|prompt)\b|^\+/v(8|9)|<[^>]*?=[^>]*?&#[^>]*?>|\b(and|or)\b.{1,6}?(=|>|<|\bin\b|\blike\b)|/\*.+?\*/|<\s*script\b|<\s*img\b|\bEXEC\b|UNION.+?SELECT|UPDATE.+?SET|INSERT\s+INTO.+?VALUES|(SELECT|DELETE).+?FROM|(CREATE|ALTER|DROP|TRUNCATE)\s+(TABLE|DATABASE)";
15     public static bool PostData()
16     {
17         bool result = false;
18         try
19         {
20             for (int i = 0; i < HttpContext.Current.Request.Form.Count; i++)
21             {
22                 result = CheckData(HttpContext.Current.Request.Form[i].ToString());
23                 if (result)
24                 {
25                     break;
26                 }
27             }
28         }
29         catch (HttpRequestValidationException ex)
30         {
31             return true;
32         }
33         return result;
34     }
35 
36     public static bool GetData()
37     {
38         bool result = false;
39         try
40         {
41             for (int i = 0; i < HttpContext.Current.Request.QueryString.Count; i++)
42             {
43                 result = CheckData(HttpContext.Current.Request.QueryString[i].ToString());
44                 if (result)
45                 {
46                     break;
47                 }
48             }
49         }
50         catch (HttpRequestValidationException ex)
51         {
52             return true;
53         }
54         return result;
55     }
56 
57     public static bool CookieData()
58     {
59         bool result = false;
60         try
61         {
62             for (int i = 0; i < HttpContext.Current.Request.Cookies.Count; i++)
63             {
64                 result = CheckData(HttpContext.Current.Request.Cookies[i].Value.ToLower());
65                 if (result)
66                 {
67                     break;
68                 }
69             }
70         }
71         catch (HttpRequestValidationException ex)
72         {
73             return true;
74         }
75         return result;
76 
77     }
78 
79     public static bool referer()
80     {
81         bool result = false;
82         return result = CheckData(HttpContext.Current.Request.UrlReferrer.ToString());
83     }
84 
85     public static bool CheckData(string inputData)
86     {
87         if (Regex.IsMatch(inputData, StrRegex))
88         {
89             return true;
90         }
91         else
92         {
93             return false;
94         }
95     }
96 }

 1     void Application_BeginRequest(object sender, EventArgs e)
 2     {
 3         if (Request.Cookies != null)
 4         {
 5             if (XSSFilter.CookieData())
 6             {
 7                 Response.Write("您提交的Cookie数据有恶意字符！");
 8                 Response.End();
 9             }
10         }
11         if (Request.UrlReferrer != null)
12         {
13             if (XSSFilter.referer())
14             {
15                 Response.Write("您提交的Referrer数据有恶意字符！");
16                 Response.End();
17             }
18         }
19         if (Request.RequestType.ToUpper() == "POST")
20         {
21             if (XSSFilter.PostData())
22             {
23                 Response.Write("您提交的Post数据有恶意字符！");
24                 Response.End();
25             }
26         }
27         if (Request.RequestType.ToUpper() == "GET")
28         {
29             if (XSSFilter.GetData())
30             {
31                 Response.Write("您提交的Get数据有恶意字符！");
32                 Response.End();
33             }
34         }
35     }