Created
May 9, 2019 16:02
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const storageGet = chrome.storage.local.get; | |
const TimeoutDelay = 2 * 1000; | |
let allowInjection = true; | |
let storedObjectPrefix = getRandomString(); | |
let storageElems; | |
let notificationTimeoutID; | |
if (window.frameElement != null && window.frameElement.sandbox != null) { | |
allowInjection = false; | |
for (let i = 0; i < window.frameElement.sandbox.length; i++) { | |
const val = window.frameElement.sandbox[i]; | |
if (val == 'allow-scripts') { | |
allowInjection = true; | |
} | |
} | |
} | |
if (allowInjection) { | |
storageGet(["docId", "data", "enabled", "whitelist"], (elems)=>{ | |
const {docId, data, enabled = true, whitelist = {}} = elems || {}; | |
if (inWhiteList(whitelist) || !data){ | |
return; | |
} | |
storageElems = elems; | |
if (enabled) { | |
overrideMethods(docId, JSON.parse(data)); | |
} else { | |
restoreMethods(docId, JSON.parse(data)); | |
} | |
}); | |
} | |
function inWhiteList(whitelist) { | |
if (window.location.href in whitelist){ | |
return true | |
} | |
const {hostname, host} = window.location; | |
if (hostname in whitelist || host in whitelist) { | |
return true; | |
} | |
return false; | |
} | |
function overrideMethods(docId, data) { | |
const script = document.createElement('script'); | |
script.id = getRandomString(); | |
script.type = "text/javascript"; | |
if (allowInjection) { | |
var newChild = document.createTextNode('try{(' + overrideDefaultMethods + ')(' + data.r + ',' + data.g + ',' + data.b + ',' + data.a + ',"' + script.id + '", "' + storedObjectPrefix + '");} catch (e) {console.error(e);}'); | |
script.appendChild(newChild); | |
var node = (document.documentElement || document.head || document.body); | |
if (typeof node[docId] === 'undefined') { | |
node.insertBefore(script, node.firstChild); | |
node[docId] = getRandomString(); | |
} | |
} | |
} | |
function restoreMethods(docId, data) { | |
const script = document.createElement('script'); | |
script.id = getRandomString(); | |
script.type = "text/javascript"; | |
if (allowInjection) { | |
var newChild = document.createTextNode('try{(' + restoreDefaultMethods + ')(' + data.r + ',' + data.g + ',' + data.b + ',' + data.a + ',"' + script.id + '", "' + storedObjectPrefix + '");} catch (e) {console.error(e);}'); | |
script.appendChild(newChild); | |
var node = (document.documentElement || document.head || document.body); | |
if (node[docId]) { | |
node.insertBefore(script, node.firstChild); | |
delete node[docId]; | |
} | |
} | |
} | |
function getRandomString() { | |
var text = ""; | |
var charset = "abcdefghijklmnopqrstuvwxyz"; | |
for (var i = 0; i < 5; i++) | |
text += charset.charAt(Math.floor(Math.random() * charset.length)); | |
return text; | |
} | |
function showNotification() { | |
console.log("showNotification"); | |
chrome.runtime.sendMessage({action: "show-notification", url: window.location.href}); | |
} | |
(function addBodyListener() { | |
window.addEventListener(storedObjectPrefix + "_show_notification", (evt)=>{ | |
if (notificationTimeoutID) { | |
clearTimeout(notificationTimeoutID); | |
} | |
notificationTimeoutID = setTimeout(showNotification, TimeoutDelay) | |
}); | |
})(); | |
function overrideDefaultMethods(r, g, b, a, scriptId, storedObjectPrefix) { | |
var scriptNode = document.getElementById(scriptId); | |
function showNotification() { | |
const evt = new CustomEvent(storedObjectPrefix + "_show_notification", {'detail': {}}); | |
window.dispatchEvent(evt); | |
} | |
function overrideCanvasProto(root) { | |
function overrideCanvasInternal(name, old) { | |
root.prototype[storedObjectPrefix + name] = old; | |
Object.defineProperty(root.prototype, name, | |
{ | |
value: function () { | |
var width = this.width; | |
var height = this.height; | |
var context = this.getContext("2d"); | |
var imageData = context.getImageData(0, 0, width, height); | |
for (var i = 0; i < height; i++) { | |
for (var j = 0; j < width; j++) { | |
var index = ((i * (width * 4)) + (j * 4)); | |
imageData.data[index + 0] = imageData.data[index + 0] + r; | |
imageData.data[index + 1] = imageData.data[index + 1] + g; | |
imageData.data[index + 2] = imageData.data[index + 2] + b; | |
imageData.data[index + 3] = imageData.data[index + 3] + a; | |
} | |
} | |
context.putImageData(imageData, 0, 0); | |
showNotification(); | |
return old.apply(this, arguments); | |
} | |
} | |
); | |
} | |
overrideCanvasInternal("toDataURL", root.prototype.toDataURL); | |
overrideCanvasInternal("toBlob", root.prototype.toBlob); | |
//overrideCanvasInternal("mozGetAsFile", root.prototype.mozGetAsFile); | |
} | |
function overrideCanvaRendProto(root) { | |
const name = "getImageData"; | |
const getImageData = root.prototype.getImageData; | |
root.prototype[storedObjectPrefix + name] = getImageData; | |
Object.defineProperty(root.prototype, "getImageData", | |
{ | |
value: function () { | |
var imageData = getImageData.apply(this, arguments); | |
var height = imageData.height; | |
var width = imageData.width; | |
// console.log("getImageData " + width + " " + height); | |
for (var i = 0; i < height; i++) { | |
for (var j = 0; j < width; j++) { | |
var index = ((i * (width * 4)) + (j * 4)); | |
imageData.data[index + 0] = imageData.data[index + 0] + r; | |
imageData.data[index + 1] = imageData.data[index + 1] + g; | |
imageData.data[index + 2] = imageData.data[index + 2] + b; | |
imageData.data[index + 3] = imageData.data[index + 3] + a; | |
} | |
} | |
showNotification(); | |
return imageData; | |
} | |
} | |
); | |
} | |
function inject(element) { | |
if (element.tagName.toUpperCase() === "IFRAME" && element.contentWindow) { | |
try { | |
var hasAccess = element.contentWindow.HTMLCanvasElement; | |
} catch (e) { | |
console.log("can't access " + e); | |
return; | |
} | |
overrideCanvasProto(element.contentWindow.HTMLCanvasElement); | |
overrideCanvaRendProto(element.contentWindow.CanvasRenderingContext2D); | |
overrideDocumentProto(element.contentWindow.Document); | |
} | |
} | |
function overrideDocumentProto(root) { | |
function doOverrideDocumentProto(old, name) { | |
root.prototype[storedObjectPrefix + name] = old; | |
Object.defineProperty(root.prototype, name, | |
{ | |
value: function () { | |
var element = old.apply(this, arguments); | |
// console.log(name+ " everridden call"+element); | |
if (element == null) { | |
return null; | |
} | |
if (Object.prototype.toString.call(element) === '[object HTMLCollection]' || | |
Object.prototype.toString.call(element) === '[object NodeList]') { | |
for (var i = 0; i < element.length; ++i) { | |
var el = element[i]; | |
// console.log("elements list inject " + name); | |
inject(el); | |
} | |
} else { | |
// console.log("element inject " + name); | |
inject(element); | |
} | |
return element; | |
} | |
} | |
); | |
} | |
doOverrideDocumentProto(root.prototype.createElement, "createElement"); | |
doOverrideDocumentProto(root.prototype.createElementNS, "createElementNS"); | |
doOverrideDocumentProto(root.prototype.getElementById, "getElementById"); | |
doOverrideDocumentProto(root.prototype.getElementsByName, "getElementsByName"); | |
doOverrideDocumentProto(root.prototype.getElementsByClassName, "getElementsByClassName"); | |
doOverrideDocumentProto(root.prototype.getElementsByTagName, "getElementsByTagName"); | |
doOverrideDocumentProto(root.prototype.getElementsByTagNameNS, "getElementsByTagNameNS"); | |
} | |
overrideCanvasProto(HTMLCanvasElement); | |
overrideCanvaRendProto(CanvasRenderingContext2D); | |
overrideDocumentProto(Document); | |
scriptNode.parentNode.removeChild(scriptNode); | |
} | |
function restoreDefaultMethods(r, g, b, a, scriptId, storedObjectPrefix) { | |
var scriptNode = document.getElementById(scriptId); | |
function overrideCanvasProto(root) { | |
function overrideCanvasInternal(name, old) { | |
root.prototype[name] = root.prototype[storedObjectPrefix + name]; | |
} | |
overrideCanvasInternal("toDataURL", root.prototype.toDataURL); | |
overrideCanvasInternal("toBlob", root.prototype.toBlob); | |
//overrideCanvasInternal("mozGetAsFile", root.prototype.mozGetAsFile); | |
} | |
function overrideCanvaRendProto(root) { | |
const name = "getImageData"; | |
root.prototype[name] = root.prototype[storedObjectPrefix + name]; | |
} | |
function inject(element) { | |
if (element.tagName.toUpperCase() === "IFRAME" && element.contentWindow) { | |
try { | |
var hasAccess = element.contentWindow.HTMLCanvasElement; | |
} catch (e) { | |
console.log("can't access " + e); | |
return; | |
} | |
overrideCanvasProto(element.contentWindow.HTMLCanvasElement); | |
overrideCanvaRendProto(element.contentWindow.CanvasRenderingContext2D); | |
overrideDocumentProto(element.contentWindow.Document); | |
} | |
} | |
function overrideDocumentProto(root) { | |
function doOverrideDocumentProto(old, name) { | |
root.prototype[name] = root.prototype[storedObjectPrefix + name]; | |
} | |
doOverrideDocumentProto(root.prototype.createElement, "createElement"); | |
doOverrideDocumentProto(root.prototype.createElementNS, "createElementNS"); | |
doOverrideDocumentProto(root.prototype.getElementById, "getElementById"); | |
doOverrideDocumentProto(root.prototype.getElementsByName, "getElementsByName"); | |
doOverrideDocumentProto(root.prototype.getElementsByClassName, "getElementsByClassName"); | |
doOverrideDocumentProto(root.prototype.getElementsByTagName, "getElementsByTagName"); | |
doOverrideDocumentProto(root.prototype.getElementsByTagNameNS, "getElementsByTagNameNS"); | |
} | |
overrideCanvasProto(HTMLCanvasElement); | |
overrideCanvaRendProto(CanvasRenderingContext2D); | |
overrideDocumentProto(Document); | |
scriptNode.parentNode.removeChild(scriptNode); | |
} |
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