112 lines
4.4 KiB
JavaScript
112 lines
4.4 KiB
JavaScript
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//JavaScript HTML Sanitizer, (c) Alexander Yumashev, Jitbit Software.
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//homepage https://github.com/jitbit/HtmlSanitizer
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//License: MIT https://github.com/jitbit/HtmlSanitizer/blob/master/LICENSE
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console.log('Sanitizer loading');
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export var HtmlSanitizer = new (function () {
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var tagWhitelist_ = {
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'A': true, 'ABBR': true, 'B': true, 'BLOCKQUOTE': true, 'BODY': true, 'BR': true, 'CENTER': true, 'CODE': true, 'DIV': true, 'EM': true, 'FONT': true,
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'H1': true, 'H2': true, 'H3': true, 'H4': true, 'H5': true, 'H6': true, 'HR': true, 'I': true, 'IMG': true, 'LABEL': true, 'LI': true, 'OL': true, 'P': true, 'PRE': true,
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'SMALL': true, 'SOURCE': true, 'SPAN': true, 'STRONG': true, 'TABLE': true, 'TBODY': true, 'TR': true, 'TD': true, 'TH': true, 'THEAD': true, 'UL': true, 'U': true, 'VIDEO': true
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};
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var contentTagWhiteList_ = { 'FORM': true }; //tags that will be converted to DIVs
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var attributeWhitelist_ = { 'align': true, 'color': true, 'controls': true, 'height': true, 'href': true, 'src': true, 'style': true, 'target': true, 'title': true, 'type': true, 'width': true };
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var cssWhitelist_ = { 'color': true, 'background-color': true, 'font-size': true, 'text-align': true, 'text-decoration': true, 'font-weight': true };
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var schemaWhiteList_ = [ 'http:', 'https:', 'data:', 'm-files:', 'file:', 'ftp:' ]; //which "protocols" are allowed in "href", "src" etc
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var uriAttributes_ = { 'href': true, 'action': true };
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this.SanitizeHtml = function(input) {
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input = input.trim();
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if (input == "") return ""; //to save performance and not create iframe
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//firefox "bogus node" workaround
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if (input == "<br>") return "";
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var iframe = document.createElement('iframe');
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if (iframe['sandbox'] === undefined) {
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alert('Your browser does not support sandboxed iframes. Please upgrade to a modern browser.');
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return '';
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}
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iframe['sandbox'] = 'allow-same-origin';
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iframe.style.display = 'none';
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document.body.appendChild(iframe); // necessary so the iframe contains a document
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var iframedoc = iframe.contentDocument || iframe.contentWindow.document;
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if (iframedoc.body == null) iframedoc.write("<body></body>"); // null in IE
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iframedoc.body.innerHTML = input;
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function makeSanitizedCopy(node) {
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if (node.nodeType == Node.TEXT_NODE) {
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var newNode = node.cloneNode(true);
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} else if (node.nodeType == Node.ELEMENT_NODE && (tagWhitelist_[node.tagName] || contentTagWhiteList_[node.tagName])) {
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//remove useless empty spans (lots of those when pasting from MS Outlook)
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if ((node.tagName == "SPAN" || node.tagName == "B" || node.tagName == "I" || node.tagName == "U")
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&& node.innerHTML.trim() == "") {
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return document.createDocumentFragment();
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}
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if (contentTagWhiteList_[node.tagName])
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newNode = iframedoc.createElement('DIV'); //convert to DIV
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else
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newNode = iframedoc.createElement(node.tagName);
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for (var i = 0; i < node.attributes.length; i++) {
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var attr = node.attributes[i];
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if (attributeWhitelist_[attr.name]) {
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if (attr.name == "style") {
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for (s = 0; s < node.style.length; s++) {
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var styleName = node.style[s];
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if (cssWhitelist_[styleName])
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newNode.style.setProperty(styleName, node.style.getPropertyValue(styleName));
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}
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}
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else {
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if (uriAttributes_[attr.name]) { //if this is a "uri" attribute, that can have "javascript:" or something
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if (attr.value.indexOf(":") > -1 && !startsWithAny(attr.value, schemaWhiteList_))
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continue;
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}
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newNode.setAttribute(attr.name, attr.value);
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}
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}
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}
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for (i = 0; i < node.childNodes.length; i++) {
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var subCopy = makeSanitizedCopy(node.childNodes[i]);
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newNode.appendChild(subCopy, false);
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}
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} else {
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newNode = document.createDocumentFragment();
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}
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return newNode;
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};
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var resultElement = makeSanitizedCopy(iframedoc.body);
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document.body.removeChild(iframe);
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return resultElement.innerHTML
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.replace(/<br[^>]*>(\S)/g, "<br>\n$1")
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.replace(/div><div/g, "div>\n<div"); //replace is just for cleaner code
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}
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function startsWithAny(str, substrings) {
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for (var i = 0; i < substrings.length; i++) {
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if (str.indexOf(substrings[i]) == 0) {
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return true;
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}
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}
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return false;
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}
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this.AllowedTags = tagWhitelist_;
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this.AllowedAttributes = attributeWhitelist_;
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this.AllowedCssStyles = cssWhitelist_;
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this.AllowedSchemas = schemaWhiteList_;
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});
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