added fingerprint lib

web/nfc-theme/static/code/GenerateCanvasFingerprint.js

@@ -0,0 +1,31 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.getCanvasFingerprint = exports.isCanvasSupported = void 0;
+const isCanvasSupported = () => {
+    var elem = document.createElement('canvas');
+    return !!(elem.getContext && elem.getContext('2d'));
+};
+exports.isCanvasSupported = isCanvasSupported;
+// this working code snippet is taken from - https://github.com/artem0/canvas-fingerprinting/blob/master/fingerprinting/fingerprint.js
+const getCanvasFingerprint = () => {
+    // If canvas is not supported simply return a static string
+    if (!(0, exports.isCanvasSupported)())
+        return "broprint.js";
+    // draw a canvas of given text and return its data uri
+    // different browser generates different dataUri based on their hardware configs
+    var canvas = document.createElement('canvas');
+    var ctx = canvas.getContext('2d');
+    // https://www.browserleaks.com/canvas#how-does-it-work
+    var txt = 'BroPrint.65@345876';
+    ctx.textBaseline = "top";
+    ctx.font = "14px 'Arial'";
+    ctx.textBaseline = "alphabetic";
+    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);
+    return canvas.toDataURL();
+};
+exports.getCanvasFingerprint = getCanvasFingerprint;