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mirror of https://github.com/kkapsner/CanvasBlocker synced 2024-10-31 18:38:45 +01:00
CanvasBlocker/test/canvasAPI.js

79 lines
2.1 KiB
JavaScript

const canvasAPI = {
draw: function draw(canvas){
"use strict";
canvas.width = 220;
canvas.height = 30;
const fingerprintText = "BrowserLeaks,com <canvas> 10";
const context = canvas.getContext("2d");
context.textBaseline = "top";
context.font = "14px 'Arial'";
context.textBaseline = "alphabetic";
context.fillStyle = "#f60";
context.fillRect(125, 1, 62, 20);
context.fillStyle = "#069";
context.fillText(fingerprintText, 2, 15);
context.fillStyle = "rgba(102, 204, 0, 07)";
context.fillText(fingerprintText, 4, 17);
return context;
},
getIsPointInPath: function getIsPointInPath(context){
"use strict";
context.beginPath();
context.moveTo(20, 19);
context.lineTo(40, 19);
context.lineTo(30, 30);
context.closePath();
context.stroke();
return context.isPointInPath(30, 19);
},
getFingerprintData: function getFingerprintData(canvas, context){
"use strict";
return {
imageData: context.getImageData(0, 0, canvas.width, canvas.height),
url: canvas.toDataURL(),
isPointInPath: canvasAPI.getIsPointInPath(context)
};
},
getFingerprintFromDifferentDocument: function getFingerprintFromDifferentDocument(otherDocument){
"use strict";
// create window canvas
const canvas = document.createElement("canvas");
// draw image in window canvas
canvasAPI.draw(canvas);
// create other canvas and context
const otherCanvas = otherDocument.createElement("canvas");
otherCanvas.setAttribute("width", 220);
otherCanvas.setAttribute("height", 30);
const otherContext = otherCanvas.getContext("2d");
// copy image from window canvas to iframe context
otherContext.drawImage(canvas, 0, 0);
return canvasAPI.getFingerprintData(otherCanvas, otherContext);
},
fingerprint: function fingerprint(windowToUse){
"use strict";
if (!windowToUse){
windowToUse = window;
}
const canvas = document.createElement("canvas");
const context = canvasAPI.draw(canvas);
if (windowToUse !== window){
return canvasAPI.getFingerprintFromDifferentDocument(windowToUse.document);
}
else {
return this.getFingerprintData(canvas, context);
}
}
};