mirror of
https://github.com/kkapsner/CanvasBlocker
synced 2024-11-13 00:28:52 +01:00
0ce446cf52
Makes #211 reproducible.
106 lines
2.8 KiB
HTML
106 lines
2.8 KiB
HTML
<html>
|
|
<body>
|
|
<div id="log"></div>
|
|
<form id="form" method="POST" action="http://localhost/server/POST-echo.php">
|
|
<input name="internalId" value="id to be used to link the requests">
|
|
<textarea style="display: block;" name="fingerprint"></textarea>
|
|
<button>submit</button>
|
|
</form>
|
|
<script>
|
|
const origin = "iframe";
|
|
function draw(canvas){
|
|
"use strict";
|
|
|
|
canvas.setAttribute("width", 220);
|
|
canvas.setAttribute("height", 30);
|
|
|
|
var fp_text = "BrowserLeaks,com <canvas> 10";
|
|
|
|
var 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 topTest(){
|
|
"use strict";
|
|
|
|
// create window canvas
|
|
var canvas = document.createElement("canvas");
|
|
// draw image in window canvas
|
|
var ctx = draw(canvas);
|
|
return {
|
|
imageData: ctx.getImageData(0, 0, canvas.width, canvas.height),
|
|
url: canvas.toDataURL(),
|
|
isPointInPath: getIsPointInPath(ctx)
|
|
};
|
|
}
|
|
function getIsPointInPath(ctx){
|
|
"use strict";
|
|
ctx.beginPath();
|
|
ctx.moveTo(20, 19);
|
|
ctx.lineTo(40, 19);
|
|
ctx.lineTo(30, 30);
|
|
ctx.closePath();
|
|
ctx.stroke();
|
|
|
|
return ctx.isPointInPath(30, 19);
|
|
};
|
|
function hashToString(hash){
|
|
var 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 send(form, {url, imageData, isPointInPath}){
|
|
var buffer = new TextEncoder("utf-8").encode(url);
|
|
Promise.all([
|
|
crypto.subtle.digest("SHA-256", buffer),
|
|
crypto.subtle.digest("SHA-256", imageData.data)
|
|
]).then(function(hashes){
|
|
var data = JSON.stringify({
|
|
urlHash: hashToString(hashes[0]),
|
|
imageDataHash: hashToString(hashes[1]),
|
|
isPointInPath
|
|
}, null, "\t");
|
|
form.fingerprint.value = data;
|
|
var xhr = new XMLHttpRequest();
|
|
xhr.open("POST", form.action, true);
|
|
xhr.onreadystatechange = function(){
|
|
if (this.readyState === 4){
|
|
const status = this.status;
|
|
if (status === 200 || status === 304) {
|
|
console.log("Sending xhr successful from", origin, ":", data);
|
|
}
|
|
else {
|
|
console.log("Sending xhr failed:", this);
|
|
}
|
|
}
|
|
};
|
|
xhr.send(new FormData(form));
|
|
window.setTimeout(function(){
|
|
form.submit();
|
|
window.setTimeout(function(){
|
|
document.getElementById("log").textContent = "You see the real canvas fingerprint, but it cannot leak from this iFrame.";
|
|
},
|
|
250
|
|
);
|
|
}, 1000);
|
|
});
|
|
}
|
|
|
|
send(document.getElementById("form"), topTest());
|
|
</script>
|
|
</body>
|
|
</html> |