ASP防XSS代码

原作是在GitHub上，基于Node.js所写。但是。。ASP的JS引擎跟V8又有些不同。。于是，嗯。。

<%
Function AntiXSS_VbsTrim(s)
    AntiXSS_VbsTrim=Trim(s)
End Function

%>
<script language="javascript" runat="server">
//原GITHUB：https://github.com/leizongmin/js-xss/blob/master/index.js
//过滤XSS攻击 @author 老雷<leizongmin@gmail.com>
//转换到ASP by zsx(http://www.zsxsoft.com)
function AntiXSS_run(html){
    String.prototype.trim=function(){return AntiXSS_VbsTrim(this)};
    return AntiXSS(html,AntiXSS_config);
}
var AntiXSS_noTag = function(text) {
    return text.replace(/</g, '<').replace(/>/g, '>');
};
function AntiXSS(html, options) {
    var whiteList = options.whiteList;
    var onTagAttr = options.onTagAttr;
    var onIgnoreTag = options.onIgnoreTag;
    var rethtml = '';
    var lastPos = 0;
    var tagStart = false;
    var quoteStart = false;
    var currentPos = 0;
    var filterAttributes = function(tagName, attrs) {
        tagName = tagName.toLowerCase();
        var whites = whiteList[tagName];
        var lastPos = 0;
        var _attrs = [];
        var tmpName = false;
        var hasSprit = false;
        var addAttr = function(name, value) {
            name = name.trim();
            if (!hasSprit && name === '/') {
                hasSprit = true;
                return;
            };
            name = name.replace(/[^a-zA-Z0-9_:\.\-]/img, '').toLowerCase();
            if (name.length < 1) return;
            if (whites.join().indexOf(name) !== -1) {
                if (value) {
                    value = value.trim().replace(/"/g, '"e;');
                    value = value.replace(/&#([a-zA-Z0-9]*);?/img,
                    function(str, code) {
                        code = parseInt(code);
                        return String.fromCharCode(code);
                    });
                    var _value = '';
                    for (var i = 0, len = value.length; i < len; i++) {
                        _value += value.charCodeAt(i) < 32 ? ' ': value.split("")[i];
                    }
                    value = _value.trim();
                    var newValue = onTagAttr(tagName, name, value);
                    if (typeof(newValue) !== 'undefined') {
                        value = newValue;
                    }
                }
                _attrs.push(name + (value ? '="' + value + '"': ''));
            }
        };
        for (var i = 0, len = attrs.length; i < len; i++) {
            var c = attrs.split("")[i];
            if (tmpName === false && c === '=') {
                tmpName = attrs.slice(lastPos, i);
                lastPos = i + 1;
                continue;
            }
            if (tmpName !== false) {
                if (i === lastPos && (c === '"' || c === "'")) {
                    var j = attrs.indexOf(c, i + 1);
                    if (j === -1) {
                        break;
                    } else {
                        var v = attrs.slice(lastPos + 1, j).trim();
                        addAttr(tmpName, v);
                        tmpName = false;
                        i = j;
                        lastPos = i + 1;
                        continue;
                    }
                }
            }
            if (c === ' ') {
                var v = attrs.slice(lastPos, i).trim();
                if (tmpName === false) {
                    addAttr(v);
                } else {
                    addAttr(tmpName, v);
                }
                tmpName = false;
                lastPos = i + 1;
                continue;
            }
        }
        if (lastPos < attrs.length) {
            if (tmpName === false) {
                addAttr(attrs.slice(lastPos));
            } else {
                addAttr(tmpName, attrs.slice(lastPos));
            }
        }
        if (hasSprit) _attrs.push('/');
        return _attrs.join(' ');
    };
    var addNewTag = function(tag, end) {
        rethtml += AntiXSS_noTag(html.slice(lastPos, tagStart));
        lastPos = end + 1;
        var spos = tag.slice(0, 2) === '</' ? 2: 1;
        var i = tag.indexOf(' ');
        if (i === -1) {
            var tagName = tag.slice(spos, tag.length - 1).trim();
        } else {
            var tagName = tag.slice(spos, i + 1).trim();
        }
        tagName = tagName.toLowerCase();
        if (tagName in whiteList) {
            if (i === -1) {
                rethtml += tag.slice(0, spos) + tagName + '>';
            } else {
                var attrs = filterAttributes(tagName, tag.slice(i + 1, tag.length - 1).trim());
                rethtml += tag.slice(0, spos) + tagName + (attrs.length > 0 ? ' ' + attrs: '') + '>';
            }
        } else {
            var options = {
                isClosing: (spos === 2),
                position: rethtml.length,
                originalPosition: currentPos - tag.length + 1
            };
            var tagHtml = onIgnoreTag(tagName, tag, options);
            if (typeof(tagHtml) === 'undefined') {
                tagHtml = AntiXSS_noTag(tag);
            }
            rethtml += tagHtml;
        }
    };
    for (var currentPos = 0, len = html.length; currentPos < len; currentPos++) {
        var c = html.split("")[currentPos];
        if (tagStart === false) {
            if (c === '<') {
                tagStart = currentPos;
                continue;
            }
        } else {
            if (quoteStart === false) {
                if (c === '<') {
                    rethtml += AntiXSS_noTag(html.slice(lastPos, currentPos));
                    tagStart = currentPos;
                    lastPos = currentPos;
                    continue;
                }
                if (c === '>') {
                    addNewTag(html.slice(tagStart, currentPos + 1), currentPos);
                    tagStart = false;
                    continue;
                }
                if (c === '"' || c === "'") {
                    quoteStart = c;
                    continue;
                }
            } else {
                if (c === quoteStart) {
                    quoteStart = false;
                    continue;
                }
            }
        }
    }
    if (lastPos < html.length) {
        rethtml += AntiXSS_noTag(html.substr(lastPos));
    }
    return rethtml;
};
var AntiXSS_config = {
    "whiteList": {
//      h1: ['style', 'class'],
//      h2: ['style', 'class'],
//      h3: ['style', 'class'],
//      h4: ['style', 'class'],
//      h5: ['style', 'class'],
//      h6: ['style', 'class'],
        hr: ['style', 'class'],
        span: ['style', 'class'],
        strong: ['style', 'class'],
        b: ['style', 'class'],
        i: ['style', 'class'],
        br: [],
        p: ['style', 'class'],
        pre: ['style', 'class'],
        code: ['style', 'class'],
        a: ['style', 'class', 'target', 'href', 'title' ,'rel'],
        img: ['style', 'class', 'src', 'alt', 'title'],
        div: ['style', 'class'],
        table: ['style', 'class', 'width', 'border'],
        tr: ['style', 'class'],
        td: ['style', 'class', 'width', 'colspan'],
        th: ['style', 'class', 'width', 'colspan'],
        tbody: ['style', 'class'],
        ul: ['style', 'class'],
        li: ['style', 'class'],
        ol: ['style', 'class'],
        dl: ['style', 'class'],
        dt: ['style', 'class'],
        em: ['style'],
//      cite: ['style'],
//      section: ['style', 'class'],
//      header: ['style', 'class'],
//      footer: ['style', 'class'],
        blockquote: ['style', 'class']//,
//      audio: ['autoplay', 'controls', 'loop', 'preload', 'src'],
//      video: ['autoplay', 'controls', 'loop', 'preload', 'src', 'height', 'width']
    },
    "onTagAttr": function(tag, attr, value) {
        if (attr === 'href' || attr === 'src') {
            if (/\/\*|\*\//mg.test(value)) {
                return '#';
            }
            if (/^[\s"'`]*((j\s*a\s*v\s*a|v\s*b|l\s*i\s*v\s*e)\s*s\s*c\s*r\s*i\s*p\s*t\s*|m\s*o\s*c\s*h\s*a):/ig.test(value)) {
                return '#';
            }
        } else if (attr === 'style') {
            if (/\/\*|\*\//mg.test(value)) {
                return '#';
            }
            if (/((j\s*a\s*v\s*a|v\s*b|l\s*i\s*v\s*e)\s*s\s*c\s*r\s*i\s*p\s*t\s*|m\s*o\s*c\s*h\s*a):/ig.test(value)) {
                return '';
            }
        }
    },
    "onIgnoreTag": function(tag, html, options) {
        return AntiXSS_noTag(html);
    }
};

</script>