1 // Unique ID creation requires a high quality random # generator. In the
2 // browser this is a little complicated due to unknown quality of Math.random()
3 // and inconsistent support for the `crypto` API. We do the best we can via
7 var crypto = global.crypto || global.msCrypto; // for IE 11
8 if (crypto && crypto.getRandomValues) {
9 // WHATWG crypto RNG - http://wiki.whatwg.org/wiki/Crypto
10 var rnds8 = new Uint8Array(16);
11 rng = function whatwgRNG() {
12 crypto.getRandomValues(rnds8);
18 // Math.random()-based (RNG)
20 // If all else fails, use Math.random(). It's fast, but is of unspecified
22 var rnds = new Array(16);
24 for (var i = 0, r; i < 16; i++) {
25 if ((i & 0x03) === 0) r = Math.random() * 0x100000000;
26 rnds[i] = r >>> ((i & 0x03) << 3) & 0xff;