const fs = require('fs') const path = require('path') const pump = require('pump') const LocalMessageDuplexStream = require('post-message-stream') const PongStream = require('ping-pong-stream/pong') const ObjectMultiplex = require('obj-multiplex') const extension = require('extensionizer') const PortStream = require('./lib/port-stream.js') const inpageContent = fs.readFileSync(path.join(__dirname, '..', '..', 'dist', 'chrome', 'inpage.js')).toString() const inpageSuffix = '//# sourceURL=' + extension.extension.getURL('inpage.js') + '\n' const inpageBundle = inpageContent + inpageSuffix // Eventually this streaming injection could be replaced with: // https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XPCOM/Language_Bindings/Components.utils.exportFunction // // But for now that is only Firefox // If we create a FireFox-only code path using that API, // MetaMask will be much faster loading and performant on Firefox. if (shouldInjectWeb3()) { setupInjection() setupStreams() } /** * Creates a script tag that injects inpage.js */ function setupInjection () { try { // inject in-page script var scriptTag = document.createElement('script') scriptTag.textContent = inpageBundle scriptTag.onload = function () { this.parentNode.removeChild(this) } var container = document.head || document.documentElement // append as first child container.insertBefore(scriptTag, container.children[0]) } catch (e) { console.error('Metamask injection failed.', e) } } /** * Sets up two-way communication streams between the * browser extension and local per-page browser context */ function setupStreams () { // setup communication to page and plugin const pageStream = new LocalMessageDuplexStream({ name: 'contentscript', target: 'inpage', }) const pluginPort = extension.runtime.connect({ name: 'contentscript' }) const pluginStream = new PortStream(pluginPort) // forward communication plugin->inpage pump( pageStream, pluginStream, pageStream, (err) => logStreamDisconnectWarning('MetaMask Contentscript Forwarding', err) ) // setup local multistream channels const mux = new ObjectMultiplex() mux.setMaxListeners(25) pump( mux, pageStream, mux, (err) => logStreamDisconnectWarning('MetaMask Inpage', err) ) pump( mux, pluginStream, mux, (err) => logStreamDisconnectWarning('MetaMask Background', err) ) // connect ping stream const pongStream = new PongStream({ objectMode: true }) pump( mux, pongStream, mux, (err) => logStreamDisconnectWarning('MetaMask PingPongStream', err) ) // connect phishing warning stream const phishingStream = mux.createStream('phishing') phishingStream.once('data', redirectToPhishingWarning) // ignore unused channels (handled by background, inpage) mux.ignoreStream('provider') mux.ignoreStream('publicConfig') } /** * Error handler for page to plugin stream disconnections * * @param {string} remoteLabel Remote stream name * @param {Error} err Stream connection error */ function logStreamDisconnectWarning (remoteLabel, err) { let warningMsg = `MetamaskContentscript - lost connection to ${remoteLabel}` if (err) warningMsg += '\n' + err.stack console.warn(warningMsg) } /** * Determines if Web3 should be injected * * @returns {boolean} {@code true} if Web3 should be injected */ function shouldInjectWeb3 () { return doctypeCheck() && suffixCheck() && documentElementCheck() && !blacklistedDomainCheck() } /** * Checks the doctype of the current document if it exists * * @returns {boolean} {@code true} if the doctype is html or if none exists */ function doctypeCheck () { const doctype = window.document.doctype if (doctype) { return doctype.name === 'html' } else { return true } } /** * Checks the current document extension * * @returns {boolean} {@code true} if the current extension is not prohibited */ function suffixCheck () { var prohibitedTypes = ['xml', 'pdf'] var currentUrl = window.location.href var currentRegex for (let i = 0; i < prohibitedTypes.length; i++) { currentRegex = new RegExp(`\\.${prohibitedTypes[i]}$`) if (currentRegex.test(currentUrl)) { return false } } return true } /** * Checks the documentElement of the current document * * @returns {boolean} {@code true} if the documentElement is an html node or if none exists */ function documentElementCheck () { var documentElement = document.documentElement.nodeName if (documentElement) { return documentElement.toLowerCase() === 'html' } return true } /** * Checks if the current domain is blacklisted * * @returns {boolean} {@code true} if the current domain is blacklisted */ function blacklistedDomainCheck () { var blacklistedDomains = [ 'uscourts.gov', 'dropbox.com', 'webbyawards.com', 'cdn.shopify.com/s/javascripts/tricorder/xtld-read-only-frame.html', 'adyen.com', 'gravityforms.com', ] var currentUrl = window.location.href var currentRegex for (let i = 0; i < blacklistedDomains.length; i++) { const blacklistedDomain = blacklistedDomains[i].replace('.', '\\.') currentRegex = new RegExp(`(?:https?:\\/\\/)(?:(?!${blacklistedDomain}).)*$`) if (!currentRegex.test(currentUrl)) { return true } } return false } /** * Redirects the current page to a phishing information page */ function redirectToPhishingWarning () { console.log('MetaMask - redirecting to phishing warning') window.location.href = 'https://metamask.io/phishing.html' }