CanvasBlocker/test/iframeTest.js

110 lines
2.5 KiB
JavaScript

// eslint-disable-next-line no-var
var log = function(){
"use strict";
return function log(...str){
if (str[str.length - 1] === "match"){
str.unshift("color: green");
str.unshift("%cOK");
}
else if (str[str.length - 1].startsWith("missmatch")){
str.unshift("color: red");
str.unshift("%cX");
}
console.log(...str);
};
}();
function draw(canvas){
"use strict";
canvas.setAttribute("width", 220);
canvas.setAttribute("height", 30);
const fp_text = "BrowserLeaks,com <canvas> 10";
const ctx = canvas.getContext("2d");
ctx.textBaseline = "top";
ctx.font = "14px 'Arial'";
ctx.textBaseline = "alphabetic";
ctx.fillStyle = "#f60";
ctx.fillRect(125, 1, 62, 20);
ctx.fillStyle = "#069";
ctx.fillText(fp_text, 2, 15);
ctx.fillStyle = "rgba(102, 204, 0, 07)";
ctx.fillText(fp_text, 4, 17);
return ctx;
}
function test(window){
"use strict";
// create window canvas
const canvas = document.createElement("canvas");
// draw image in window canvas
draw(canvas);
return window.HTMLCanvasElement.prototype.toDataURL.call(canvas);
}
async function hash(string){
"use strict";
const buffer = new TextEncoder("utf-8").encode(string);
const hash = await crypto.subtle.digest("SHA-256", buffer);
const chunks = [];
(new Uint32Array(hash)).forEach(function(num){
chunks.push(num.toString(16));
});
return chunks.map(function(chunk){
return "0".repeat(8 - chunk.length) + chunk;
}).join("");
}
function compare(string1, string2, alwaysOutputHashes){
"use strict";
async function outputHashes(message){
const hashes = await Promise.all([
hash(string1),
hash(string2)
]);
console.log(message, ...hashes);
}
if (string1 === string2){
if (alwaysOutputHashes){
outputHashes("Matching hashes:");
}
return "match";
}
else {
outputHashes("Hashes that differ:");
if (string1.length === string2.length){
let i;
for (i = 0; i < string1.length; i += 1){
if (string1.charAt(i) !== string2.charAt(i)){
break;
}
}
return "missmatch (first at " + i + ")";
}
else {
let i;
for (i = 0; i < Math.min(string1.length, string2.length); i += 1){
if (string1.charAt(i) !== string2.charAt(i)){
break;
}
}
return "missmatch (different lengths, first at " + i + ")";
}
}
}
// eslint-disable-next-line no-var
var reference = test(window);
(async function(){
"use strict";
try {
const hashValue = await hash(reference);
log("reference hash:", hashValue);
}
catch (error){
log("%cX", "color: red", "Unable to compute reference hash:", error);
}
}());