mirror of
https://github.com/lunaisnotaboy/mastodon.git
synced 2024-09-11 04:36:45 +00:00
also including some refactoring: - add `// @ts-check` - use Map to completely avoid prototype pollution - assign random id to each iframe for reduce chance to brute-force attack, and leak of iframe counts - check iframe.contentWindow and MessageEvent.source to validate message is coming from correct iframe (it works on latest Chrome/Firefox/Safari but I'm not sure this is allowed by spec) follow-up of #17420 fix #18299
66 lines
1.6 KiB
JavaScript
66 lines
1.6 KiB
JavaScript
// @ts-check
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(function() {
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'use strict';
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/**
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* @param {() => void} loaded
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*/
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var ready = function(loaded) {
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if (['interactive', 'complete'].indexOf(document.readyState) !== -1) {
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loaded();
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} else {
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document.addEventListener('DOMContentLoaded', loaded);
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}
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};
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ready(function() {
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/** @type {Map<number, HTMLIFrameElement>} */
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var iframes = new Map();
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window.addEventListener('message', function(e) {
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var data = e.data || {};
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if (typeof data !== 'object' || data.type !== 'setHeight' || !iframes.has(data.id)) {
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return;
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}
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var iframe = iframes.get(data.id);
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if ('source' in e && iframe.contentWindow !== e.source) {
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return;
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}
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iframe.height = data.height;
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});
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[].forEach.call(document.querySelectorAll('iframe.mastodon-embed'), function(iframe) {
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// select unique id for each iframe
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var id = 0, failCount = 0, idBuffer = new Uint32Array(1);
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while (id === 0 || iframes.has(id)) {
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id = crypto.getRandomValues(idBuffer)[0];
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failCount++;
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if (failCount > 100) {
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// give up and assign (easily guessable) unique number if getRandomValues is broken or no luck
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id = -(iframes.size + 1);
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break;
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}
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}
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iframes.set(id, iframe);
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iframe.scrolling = 'no';
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iframe.style.overflow = 'hidden';
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iframe.onload = function() {
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iframe.contentWindow.postMessage({
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type: 'setHeight',
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id: id,
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}, '*');
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};
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iframe.onload();
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});
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});
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})();
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