取代cookie的网站追踪技术：”帆布指纹识别”初探

bin2hex.js

function bin2hex (bin)
{
  var i = 0, l = bin.length, chr, hex = '';
  for (i; i < l; ++i)
  {
    chr = bin.charCodeAt(i).toString(16)
    hex += chr.length < 2 ? '0' + chr : chr
  }
  return hex
}

canvas_fingerprint.js

var canvas = document.createElement('canvas');
var ctx = canvas.getContext('2d');
var txt = 'http://security.tencent.com/';
ctx.textBaseline = "top";
ctx.font = "14px 'Arial'";
ctx.textBaseline = "tencent";
ctx.fillStyle = "#f60";
ctx.fillRect(125,1,62,20);
ctx.fillStyle = "#069";
ctx.fillText(txt, 2, 15);
ctx.fillStyle = "rgba(102, 204, 0, 0.7)";
ctx.fillText(txt, 4, 17);

var b64 = canvas.toDataURL().replace("data:image/png;base64,","");
var bin = atob(b64);
var crc = bin2hex(bin.slice(-16,-12));
console.log(crc);