canvas获取浏览器指纹-唯一的设备标识

<meta charset="utf-8">
<title>canvas获取浏览器指纹-唯一的设备标识</title>

<script>
    function bin2hex(str) {
        var result = "";
        for (i = 0; i < str.length; i++ ) {
            result += int16_to_hex(str.charCodeAt(i));
        }
        return result;
    }
    
    function int16_to_hex(i) {
        var result = i.toString(16);
        var j = 0;
        while (j+result.length < 4){
            result = "0" + result;
            j++;
        }
        return result;
    }
function cans(str){
    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));
    //var crc = bin.slice(-16,-12);
return crc;//alert(crc);
}
cans()
</script>
 

<p>canvas获取浏览器指纹-唯一的设备标识：<span id="cab"></span></p>
<br /><br />


<script>
document.getElementById("cab").innerHTML=cans("http://security.tencent.com/");
</script>