126 lines
3.7 KiB
JavaScript
126 lines
3.7 KiB
JavaScript
import xss from 'pretty-text/xss';
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function attr(name, value) {
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if (value) {
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return `${name}="${xss.escapeAttrValue(value)}"`;
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}
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return name;
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}
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const ESCAPE_REPLACEMENTS = {
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"&": "&",
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"<": "<",
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">": ">",
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'"': """,
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"'": "'",
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'`': '`'
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};
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const BAD_CHARS = /[&<>"'`]/g;
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const POSSIBLE_CHARS = /[&<>"'`]/;
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function escapeChar(chr) {
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return ESCAPE_REPLACEMENTS[chr];
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}
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export function escape(string) {
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// don't escape SafeStrings, since they're already safe
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if (string === null) {
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return "";
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} else if (!string) {
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return string + '';
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}
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// Force a string conversion as this will be done by the append regardless and
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// the regex test will do this transparently behind the scenes, causing issues if
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// an object's to string has escaped characters in it.
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string = "" + string;
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if (!POSSIBLE_CHARS.test(string)) { return string; }
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return string.replace(BAD_CHARS, escapeChar);
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}
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export function hrefAllowed(href, extraHrefMatchers) {
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// escape single quotes
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href = href.replace(/'/g, "%27");
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// absolute urls
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if (/^(https?:)?\/\/[\w\.\-]+/i.test(href)) { return href; }
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// relative urls
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if (/^\/[\w\.\-]+/i.test(href)) { return href; }
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// anchors
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if (/^#[\w\.\-]+/i.test(href)) { return href; }
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// mailtos
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if (/^mailto:[\w\.\-@]+/i.test(href)) { return href; }
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if (extraHrefMatchers && extraHrefMatchers.length > 0) {
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for (let i=0; i<extraHrefMatchers.length; i++) {
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if (extraHrefMatchers[i].test(href)) { return href; }
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}
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}
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}
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export function sanitize(text, whiteLister) {
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if (!text) return "";
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// Allow things like <3 and <_<
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text = text.replace(/<([^A-Za-z\/\!]|$)/g, "<$1");
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const whiteList = whiteLister.getWhiteList(),
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allowedHrefSchemes = whiteLister.getAllowedHrefSchemes(),
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allowedIframes = whiteLister.getAllowedIframes();
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let extraHrefMatchers = null;
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if (allowedHrefSchemes && allowedHrefSchemes.length > 0) {
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extraHrefMatchers = [new RegExp('^(' + allowedHrefSchemes.join('|') + '):\/\/[\\w\\.\\-]+','i')];
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}
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let result = xss(text, {
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whiteList: whiteList.tagList,
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stripIgnoreTag: true,
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stripIgnoreTagBody: ['script', 'table'],
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onIgnoreTagAttr(tag, name, value) {
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const forTag = whiteList.attrList[tag];
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if (forTag) {
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const forAttr = forTag[name];
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if (
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(forAttr && (forAttr.indexOf('*') !== -1 || forAttr.indexOf(value) !== -1)) ||
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(name.indexOf('data-') === 0 && forTag['data-*']) ||
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((tag === 'a' && name === 'href') && hrefAllowed(value, extraHrefMatchers)) ||
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(tag === 'img' && name === 'src' && (/^data:image.*$/i.test(value) || hrefAllowed(value, extraHrefMatchers))) ||
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(tag === 'iframe' && name === 'src' && allowedIframes.some(i => { return value.toLowerCase().indexOf((i || '').toLowerCase()) === 0;}))
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) {
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return attr(name, value);
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}
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if (tag === 'iframe' && name === 'src') {
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return "-STRIP-";
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}
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// Heading ids must begin with `heading--`
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if (
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['h1', 'h2', 'h3', 'h4', 'h5', 'h6'].indexOf(tag) !== -1 &&
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value.match(/^heading\-\-[a-zA-Z0-9\-\_]+$/)
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) {
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return attr(name, value);
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}
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const custom = whiteLister.getCustom();
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for (let i=0; i<custom.length; i++) {
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const fn = custom[i];
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if (fn(tag, name, value)) {
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return attr(name, value);
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}
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}
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}
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},
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});
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return result.replace(/\[removed\]/g, '')
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.replace(/\<iframe[^>]+\-STRIP\-[^>]*>[^<]*<\/iframe>/g, '')
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.replace(/&(?![#\w]+;)/g, '&')
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.replace(/'/g, "'")
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.replace(/ \/>/g, '>');
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};
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