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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;
///<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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