const fs = require('fs')
const path = require('path')
const pump = require('pump')
const log = require('loglevel')
const Dnode = require('dnode')
const querystring = require('querystring')
const LocalMessageDuplexStream = require('post-message-stream')
const ObjectMultiplex = require('obj-multiplex')
const extension = require('extensionizer')
const PortStream = require('extension-port-stream')
// const injectedScript = require('./inpage_stringify')
// console.log(`typeof(injectedScript)`, typeof injectedScript)
const inpageContent = fs.readFileSync(path.join(__dirname, '..', '..', 'dist', 'chrome', 'inpage.js'), 'utf8');
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()) {
injectScript(inpageBundle)
start()
}
/**
* Injects a script tag into the current document
*
* @param {string} content - Code to be executed in the current document
*/
function injectScript (content) {
try {
const container = document.head || document.documentElement
const scriptTag = document.createElement('script')
scriptTag.setAttribute('async', false)
// scriptTag.src = extension.runtime.getURL('inpage.js')
scriptTag.textContent = content
container.insertBefore(scriptTag, container.children[0])
container.removeChild(scriptTag)
} catch (e) {
console.error('MetaMask script injection failed', e)
}
}
/**
* Sets up the stream communication and submits site metadata
*
*/
async function start () {
await setupStreams()
await domIsReady()
}
/**
* Sets up two-way communication streams between the
* browser extension and local per-page browser context.
*
*/
async function setupStreams () {
// the transport-specific streams for communication between inpage and background
const pageStream = new LocalMessageDuplexStream({
name: 'contentscript_tangerine',
target: 'inpage_tangerine',
})
const extensionPort = extension.runtime.connect({ name: 'contentscript' })
const extensionStream = new PortStream(extensionPort)
// create and connect channel muxers
// so we can handle the channels individually
const pageMux = new ObjectMultiplex()
pageMux.setMaxListeners(100)
const extensionMux = new ObjectMultiplex()
extensionMux.setMaxListeners(100)
pump(
pageMux,
pageStream,
pageMux,
(err) => logStreamDisconnectWarning('MetaMask Inpage Multiplex', err)
)
pump(
extensionMux,
extensionStream,
extensionMux,
(err) => logStreamDisconnectWarning('MetaMask Background Multiplex', err)
)
// forward communication across inpage-background for these channels only
forwardTrafficBetweenMuxers('provider', pageMux, extensionMux)
forwardTrafficBetweenMuxers('publicConfig', pageMux, extensionMux)
// connect "phishing" channel to warning system
const phishingStream = extensionMux.createStream('phishing')
phishingStream.once('data', redirectToPhishingWarning)
// connect "publicApi" channel to submit page metadata
const publicApiStream = extensionMux.createStream('publicApi')
const background = await setupPublicApi(publicApiStream)
return { background }
}
function forwardTrafficBetweenMuxers (channelName, muxA, muxB) {
const channelA = muxA.createStream(channelName)
const channelB = muxB.createStream(channelName)
pump(
channelA,
channelB,
channelA,
(err) => logStreamDisconnectWarning(`MetaMask muxed traffic for channel "${channelName}" failed.`, err)
)
}
async function setupPublicApi (outStream) {
const api = {
getSiteMetadata: (cb) => cb(null, getSiteMetadata()),
}
const dnode = Dnode(api)
pump(
outStream,
dnode,
outStream,
(err) => {
// report any error
if (err) log.error(err)
}
)
const background = await new Promise(resolve => dnode.once('remote', resolve))
return background
}
/**
* Gets site metadata and returns it
*
*/
function getSiteMetadata () {
// get metadata
const metadata = {
name: getSiteName(window),
icon: getSiteIcon(window),
}
return metadata
}
/**
* Error handler for page to extension stream disconnections
*
* @param {string} remoteLabel Remote stream name
* @param {Error} err Stream connection error
*/
function logStreamDisconnectWarning (remoteLabel, err) {
let warningMsg = `MetamaskContentscript - lost connection to ${remoteLabel}`
if (err) warningMsg += '\n' + err.stack
console.warn(warningMsg)
}
/**
* Determines if Web3 should be injected
*
* @returns {boolean} {@code true} if Web3 should be injected
*/
function shouldInjectWeb3 () {
return doctypeCheck() && suffixCheck() &&
documentElementCheck() && !blacklistedDomainCheck()
}
/**
* Checks the doctype of the current document if it exists
*
* @returns {boolean} {@code true} if the doctype is html or if none exists
*/
function doctypeCheck () {
const doctype = window.document.doctype
if (doctype) {
return doctype.name === 'html'
} else {
return true
}
}
/**
* Returns whether or not the extension (suffix) of the current document is prohibited
*
* This checks {@code window.location.pathname} against a set of file extensions
* that should not have web3 injected into them. This check is indifferent of query parameters
* in the location.
*
* @returns {boolean} whether or not the extension of the current document is prohibited
*/
function suffixCheck () {
const prohibitedTypes = [
/\.xml$/,
/\.pdf$/,
]
const currentUrl = window.location.pathname
for (let i = 0; i < prohibitedTypes.length; i++) {
if (prohibitedTypes[i].test(currentUrl)) {
return false
}
}
return true
}
/**
* Checks the documentElement of the current document
*
* @returns {boolean} {@code true} if the documentElement is an html node or if none exists
*/
function documentElementCheck () {
const documentElement = document.documentElement.nodeName
if (documentElement) {
return documentElement.toLowerCase() === 'html'
}
return true
}
/**
* Checks if the current domain is blacklisted
*
* @returns {boolean} {@code true} if the current domain is blacklisted
*/
function blacklistedDomainCheck () {
const blacklistedDomains = [
'uscourts.gov',
'dropbox.com',
'webbyawards.com',
'cdn.shopify.com/s/javascripts/tricorder/xtld-read-only-frame.html',
'adyen.com',
'gravityforms.com',
'harbourair.com',
'ani.gamer.com.tw',
'blueskybooking.com',
'sharefile.com',
]
const currentUrl = window.location.href
let currentRegex
for (let i = 0; i < blacklistedDomains.length; i++) {
const blacklistedDomain = blacklistedDomains[i].replace('.', '\\.')
currentRegex = new RegExp(`(?:https?:\\/\\/)(?:(?!${blacklistedDomain}).)*$`)
if (!currentRegex.test(currentUrl)) {
return true
}
}
return false
}
/**
* Redirects the current page to a phishing information page
*/
function redirectToPhishingWarning () {
console.log('MetaMask - routing to Phishing Warning component')
const extensionURL = extension.runtime.getURL('phishing.html')
window.location.href = `${extensionURL}#${querystring.stringify({
hostname: window.location.hostname,
href: window.location.href,
})}`
}
/**
* Extracts a name for the site from the DOM
*/
function getSiteName (window) {
const document = window.document
const siteName = document.querySelector('head > meta[property="og:site_name"]')
if (siteName) {
return siteName.content
}
const metaTitle = document.querySelector('head > meta[name="title"]')
if (metaTitle) {
return metaTitle.content
}
return document.title
}
/**
* Extracts an icon for the site from the DOM
*/
function getSiteIcon (window) {
const document = window.document
// Use the site's favicon if it exists
const shortcutIcon = document.querySelector('head > link[rel="shortcut icon"]')
if (shortcutIcon) {
return shortcutIcon.href
}
// Search through available icons in no particular order
const icon = Array.from(document.querySelectorAll('head > link[rel="icon"]')).find((icon) => Boolean(icon.href))
if (icon) {
return icon.href
}
return null
}
/**
* Returns a promise that resolves when the DOM is loaded (does not wait for images to load)
*/
async function domIsReady () {
// already loaded
if (['interactive', 'complete'].includes(document.readyState)) return
// wait for load
await new Promise(resolve => window.addEventListener('DOMContentLoaded', resolve, { once: true }))
}
