154 lines
3.9 KiB
JavaScript
154 lines
3.9 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)) {
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return string;
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}
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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)) {
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return href;
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}
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// relative urls
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if (/^\/[\w\.\-]+/i.test(href)) {
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return href;
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}
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// anchors
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if (/^#[\w\.\-]+/i.test(href)) {
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return href;
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}
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// mailtos
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if (/^mailto:[\w\.\-@]+/i.test(href)) {
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return href;
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}
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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)) {
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return href;
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}
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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 = [
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new RegExp("^(" + allowedHrefSchemes.join("|") + ")://[\\w\\.\\-]+", "i")
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];
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if (allowedHrefSchemes.includes("tel")) {
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extraHrefMatchers.push(new RegExp("^tel://\\+?[\\w\\.\\-]+", "i"));
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}
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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 &&
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(forAttr.indexOf("*") !== -1 || forAttr.indexOf(value) !== -1)) ||
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(name.indexOf("data-") === 0 && forTag["data-*"]) ||
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(tag === "a" &&
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name === "href" &&
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hrefAllowed(value, extraHrefMatchers)) ||
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(tag === "img" &&
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name === "src" &&
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(/^data:image.*$/i.test(value) ||
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hrefAllowed(value, extraHrefMatchers))) ||
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(tag === "iframe" &&
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name === "src" &&
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allowedIframes.some(i => {
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return value.toLowerCase().indexOf((i || "").toLowerCase()) === 0;
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}))
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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
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.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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