C#代码
- using System;
- using System.IO;
- using System.Text;
- using System.Text.RegularExpressions;
- using System.Runtime.Remoting;
- using System.Runtime.Remoting.Proxies;
- using System.Runtime.Remoting.Messaging;
- using System.Reflection;
- namespace FilterRealProxy
- {
- /**//// <summary>
- /// FilterRealProxy类：一个真实代理, 拦截它所代理对象中方法的返回值，并对需要过滤的返回值进行过滤。
- /// </summary>
- public class FilterRealProxy:RealProxy
- {
- private MarshalByRefObject target;
- public FilterRealProxy(MarshalByRefObject target):base(target.GetType())
- {
- this.target=target;
- }
- public override IMessage Invoke(IMessage msg)
- {
- IMethodCallMessage callMsg=msg as IMethodCallMessage;
- IMethodReturnMessage returnMsg = RemotingServices.ExecuteMessage(target,callMsg);
- //检查返回值是否为String,如果不是String,就没必要进行过滤
- if(this.IsMatchType(returnMsg.ReturnValue))
- {
- string returnValue=this.Filter(returnMsg.ReturnValue.ToString(),returnMsg.MethodName);
- return new ReturnMessage(returnValue,null,0,null,callMsg);
- }
- return returnMsg;
- }
- protected string Filter(string ReturnValue,string MethodName)
- {
- MethodInfo methodInfo=target.GetType().GetMethod(MethodName);
- object[] attributes=methodInfo.GetCustomAttributes(typeof(StringFilter),true);
- foreach (object attrib in attributes)
- {
- return FilterHandler.Process(((StringFilter)attrib).FilterType,ReturnValue);
- }
- return ReturnValue;
- }
- protected bool IsMatchType(object obj)
- {
- return obj is System.String;
- }
- }
- /**////<summary>
- /// StringFilter类：自定义属性类, 定义目标元素的过滤类型
- ///</summary>
- public class StringFilter:Attribute
- {
- protected FilterType _filterType;
- public StringFilter(FilterType filterType)
- {
- this._filterType=filterType;
- }
- public FilterType FilterType
- {
- get
- {
- return _filterType;
- }
- }
- }
- /**//// <summary>
- /// 枚举类：用于指定过滤类型，例如：对script过滤还是对html进行过滤？
- /// </summary>
- [Flags()]
- public enum FilterType
- {
- Script = 1,
- Html =2,
- Object=3,
- AHrefScript=4,
- Iframe=5,
- Frameset=6,
- Src=7,
- BadWords=8,
- //Include=9,
- All=16
- }
- /**////<summary>
- /// 过滤处理类：根据过滤类型，调用相应的过滤处理方法。
- ///</summary>
- public class FilterHandler
- {
- private FilterHandler()
- {
- }
- public static string Process(FilterType filterType,string filterContent)
- {
- switch(filterType)
- {
- case FilterType.Script:
- filterContent=FilterScript(filterContent);
- break;
- case FilterType.Html:
- filterContent=FilterHtml(filterContent);
- break;
- case FilterType.Object:
- filterContent=FilterObject(filterContent);
- break;
- case FilterType.AHrefScript:
- filterContent=FilterAHrefScript(filterContent);
- break;
- case FilterType.Iframe:
- filterContent=FilterIframe(filterContent);
- break;
- case FilterType.Frameset:
- filterContent=FilterFrameset(filterContent);
- break;
- case FilterType.Src:
- filterContent=FilterSrc(filterContent);
- break;
- //case FilterType.Include:
- // filterContent=FilterInclude(filterContent);
- // break;
- case FilterType.BadWords:
- filterContent=FilterBadWords(filterContent);
- break;
- case FilterType.All:
- filterContent=FilterAll(filterContent);
- break;
- default:
- //do nothing
- break;
- }
- return filterContent;
- }
- public static string FilterScript(string content)
- {
- string commentPattern = @"(?'comment'<!--.*?--[ \n\r]*>)" ;
- string embeddedScriptComments = @"(\/\*.*?\*\/|\/\/.*?[\n\r])" ;
- string scriptPattern = String.Format(@"(?'script'<[ \n\r]*script[^>]*>(.*?{0}?)*<[ \n\r]*/script[^>]*>)", embeddedScriptComments ) ;
- // 包含注释和Script语句
- string pattern = String.Format(@"(?s)({0}|{1})", commentPattern, scriptPattern) ;
- return StripScriptAttributesFromTags(Regex.Replace(content,pattern,string.Empty,RegexOptions.IgnoreCase));
- }
- private static string StripScriptAttributesFromTags( string content )
- {
- string eventAttribs = @"on(blur|c(hange|lick)|dblclick|focus|keypress|(key|mouse)(down|up)|(un)?load
- |mouse(move|o(ut|ver))|reset|s(elect|ubmit))" ;
- string pattern = String.Format(@"(?inx)
- \<(\w+)\s+
- (
- (?'attribute'
- (?'attributeName'{0})\s*=\s*
- (?'delim'['""]?)
- (?'attributeValue'[^'"">]+)
- (\3)
- )
- |
- (?'attribute'
- (?'attributeName'href)\s*=\s*
- (?'delim'['""]?)
- (?'attributeValue'javascript[^'"">]+)
- (\3)
- )
- |
- [^>]
- )*
- \>", eventAttribs ) ;
- Regex re = new Regex( pattern ) ;
- // 使用MatchEvaluator的委托
- return re.Replace( content, new MatchEvaluator( StripAttributesHandler ) ) ;
- }
- private static string StripAttributesHandler( Match m )
- {
- if( m.Groups["attribute"].Success )
- {
- return m.Value.Replace( m.Groups["attribute"].Value, "") ;
- }
- else
- {
- return m.Value ;
- }
- }
- public static string FilterAHrefScript(string content)
- {
- string newstr=FilterScript(content);
- string regexstr=@" href[ ^=]*= *[\s\S]*script *:";
- return Regex.Replace(newstr,regexstr,string.Empty,RegexOptions.IgnoreCase);
- }
- public static string FilterSrc(string content)
- {
- string newstr=FilterScript(content);
- string regexstr=@" src *= *['""]?[^\.]+\.(js|vbs|asp|aspx|php|jsp)['""]";
- return Regex.Replace(newstr,regexstr,@"",RegexOptions.IgnoreCase);
- }
- /**//*
- public static string FilterInclude(string content)
- {
- string newstr=FilterScript(content);
- string regexstr=@"<[\s\S]*include *(file|virtual) *= *[\s\S]*\.(js|vbs|asp|aspx|php|jsp)[^>]*>";
- return Regex.Replace(newstr,regexstr,string.Empty,RegexOptions.IgnoreCase);
- }
- */
- public static string FilterHtml(string content)
- {
- string newstr=FilterScript(content);
- string regexstr=@"<[^>]*>";
- return Regex.Replace(newstr,regexstr,string.Empty,RegexOptions.IgnoreCase);
- }
- public static string FilterObject(string content)
- {
- string regexstr=@"(?i)<Object([^>])*>(\w|\W)*</Object([^>])*>";
- return Regex.Replace(content,regexstr,string.Empty,RegexOptions.IgnoreCase);
- }
- public static string FilterIframe(string content)
- {
- string regexstr=@"(?i)<Iframe([^>])*>(\w|\W)*</Iframe([^>])*>";
- return Regex.Replace(content,regexstr,string.Empty,RegexOptions.IgnoreCase);
- }
- public static string FilterFrameset(string content)
- {
- string regexstr=@"(?i)<Frameset([^>])*>(\w|\W)*</Frameset([^>])*>";
- return Regex.Replace(content,regexstr,string.Empty,RegexOptions.IgnoreCase);
- }
- //移除非法或不友好字符
- private static string FilterBadWords(string chkStr)
- {
- //这里的非法和不友好字符由你任意加，用“|”分隔，支持正则表达式,由于本Blog禁止贴非法和不友好字符，所以这里无法加上。
- string BadWords=@"";
- if (chkStr == "")
- {
- return "";
- }
- string[] bwords = BadWords.Split('#');
- int i,j;
- string str;
- StringBuilder sb = new StringBuilder();
- for(i = 0; i< bwords.Length; i++)
- {
- str=bwords[i].ToString().Trim();
- string regStr,toStr;
- regStr=str;
- Regex r=new Regex(regStr,RegexOptions.IgnoreCase | RegexOptions.Singleline| RegexOptions.Multiline);
- Match m=r.Match(chkStr);
- if(m.Success)
- {
- j=m.Value.Length;
- sb.Insert(0,"*",j);
- toStr=sb.ToString();
- chkStr=Regex.Replace(chkStr,regStr,toStr,RegexOptions.IgnoreCase | RegexOptions.Singleline| RegexOptions.Multiline);
- }
- sb.Remove(0,sb.Length);
- }
- return chkStr;
- }
- public static string FilterAll(string content)
- {
- content = FilterHtml(content);
- content = FilterScript(content);
- content = FilterAHrefScript(content);
- content = FilterObject(content);
- content = FilterIframe(content);
- content = FilterFrameset(content);
- content = FilterSrc(content);
- content = FilterBadWords(content);
- //content = FilterInclude(content);
- return content;
- }
- }
- }
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