javascript过滤危险脚本方法

　　下面是他们的字符串规则：

　　1、<(script|link|style|iframe)(.|\n)*<\/\1>\s*

　　2、\s*on[a-z]+\s*=\s*("[^"]+"|'[^']+'|[^\s]+)\s*(?=>)

　　4、epression\((.|\n)*\);?

　　了解他们的规则后，抓虫行动就水到渠成。

<textarea id="bug" cols="80" rows="16"> 
<button id="kick">抓虫1</button> 
<img src="/_New/_cj/myeditor/sysimage/space.gif" class="ewebeditor__script" _ewebeditor_fake_tag="script" _ewebeditor_fake_value="%3Cscript%3E%20%0D%0Afunction%20kickBug(str)%20%7B%20%0D%0Areturn%20str.replace(%2F%3C(script%7Clink%7Cstyle%7Ciframe)(.%7C%5Cn)*%5C%2F%5C1%3E%5Cs*%2Fig%2C%22%22)%3B%20%0D%0A%7D%20%0D%0A%3C%2Fscript%3E"> 
<iframe></iframe> 
<link href='test.css'></link> 
<style> 
a { 
height:expression(alert('hei')); 
} 
</style> 
</textarea> 
<button id="kick">抓虫1</button> 
<img src="/_New/_cj/myeditor/sysimage/space.gif" class="ewebeditor__script" _ewebeditor_fake_tag="script" _ewebeditor_fake_value="%3Cscript%3E%20%0D%0Afunction%20kickBug(str)%20%7B%20%0D%0Areturn%20str.replace(%2F%3C(script%7Clink%7Cstyle%7Ciframe)(.%7C%5Cn)*%5C%2F%5C1%3E%5Cs*%2Fig%2C%22%22)%3B%20%0D%0A%7D%20%0D%0Aif(!%2Fmsie%2Fi.test(navigator.userAgent))%7B%20%0D%0AHTMLElement.prototype.__defineGetter__(%22innerText%22%2Cfunction()%7B%20%0D%0Areturn%20this.textContent%3B%20%0D%0A%7D)%3B%20%0D%0AHTMLElement.prototype.__defineSetter__(%22innerText%22%2Cfunction(text)%7B%20%0D%0Athis.textContent%20%3D%20text%3B%20%0D%0A%7D)%3B%20%0D%0A%7D%20%0D%0Adocument.getElementById(%22kick%22).onclick%20%3D%20function()%20%7B%20%0D%0Avar%20bug%20%3D%20document.getElementById(%22bug%22)%3B%20%0D%0Abug.innerText%20%3D%20kickBug(bug.innerText)%3B%20%0D%0A%7D%20%0D%0A%3C%2Fscript%3E">

　　 [Ctrl+A 全选注:如需引入外部Js需刷新才能执行]

　　 [Ctrl+A 全选注:如需引入外部Js需刷新才能执行]

　　 [Ctrl+A 全选注:如需引入外部Js需刷新才能执行]

<textarea id="bug" cols="80" rows="5"> 
expression() 
<a style="color:expression( 
'red' 
)">test</a> 
</textarea> 
<button id="kick">抓虫4</button> 
<img src="/_New/_cj/myeditor/sysimage/space.gif" class="ewebeditor__script" _ewebeditor_fake_tag="script" _ewebeditor_fake_value="%3Cscript%3E%20%0D%0Afunction%20kickBug(str)%20%7B%20%0D%0Areturn%20str.replace(%2F%3C%5Ba-z%5D%5B%5E%3E%5D*%5Cs*style%5Cs*%3D%5B%5E%3E%5D%2B%2Fig%2Cfunction(%240%2C%241)%7B%20%0D%0A%240%20%3D%20%240.replace(%2F%26%23(6%5B5-9%5D%7C%5B78%5D%5B0-9%5D%7C9%5B0789%5D%7C1%5B01%5D%5B0-9%5D%7C12%5B012%5D)%3B%3F%2Fg%2Cfunction(%240%2C%241)%7Breturn%20String.fromCharCode(%241)%3B%7D)%3B%20%0D%0Areturn%20%240.replace(%2F%5Cs*style%5Cs*%3D%5Cs*(%22%5B%5E%22%5D%2B(expression)%5B%5E%22%5D%2B%22%7C'%5B%5E'%5D%2B%5C2%5B%5E'%5D%2B'%7C%5B%5E%5Cs%5D%2B%5C2%5B%5E%5Cs%5D%2B)%5Cs*%2Fig%2C%22%22)%3B%20%0D%0A%7D)%3B%20%0D%0A%7D%20%0D%0Aif(!%2Fmsie%2Fi.test(navigator.userAgent))%7B%20%0D%0AHTMLElement.prototype.__defineGetter__(%22innerText%22%2Cfunction()%7B%20%0D%0Areturn%20this.textContent%3B%20%0D%0A%7D)%3B%20%0D%0AHTMLElement.prototype.__defineSetter__(%22innerText%22%2Cfunction(text)%7B%20%0D%0Athis.textContent%20%3D%20text%3B%20%0D%0A%7D)%3B%20%0D%0A%7D%20%0D%0Adocument.getElementById(%22kick%22).onclick%20%3D%20function()%20%7B%20%0D%0Avar%20bug%20%3D%20document.getElementById(%22bug%22)%3B%20%0D%0Abug.innerText%20%3D%20kickBug(bug.innerText)%3B%20%0D%0A%7D%20%0D%0A%3C%2Fscript%3E">

　　 [Ctrl+A 全选注:如需引入外部Js需刷新才能执行]

　　这样调用就可以

　　k1(k2(k3(k4(str))))

　　这样就是单纯地过滤脚本而已，所谓过滤“危险脚本”应该是能够判断哪些属于“危险"脚本，不危险的就不过滤才对……那可就难办了，相当于防火墙了。

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