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
6 // getRandomValues needs to be invoked in a context where "this" is a Crypto
7 // implementation. Also, find the complete implementation of crypto on IE11.
8 var getRandomValues = (typeof(crypto) != 'undefined' && crypto.getRandomValues && crypto.getRandomValues.bind(crypto)) ||
9 (typeof(msCrypto) != 'undefined' && typeof window.msCrypto.getRandomValues == 'function' && msCrypto.getRandomValues.bind(msCrypto));
11 if (getRandomValues) {
12 // WHATWG crypto RNG - http://wiki.whatwg.org/wiki/Crypto
13 var rnds8 = new Uint8Array(16); // eslint-disable-line no-undef
15 module.exports = function whatwgRNG() {
16 getRandomValues(rnds8);
20 // Math.random()-based (RNG)
22 // If all else fails, use Math.random(). It's fast, but is of unspecified
24 var rnds = new Array(16);
26 module.exports = function mathRNG() {
27 for (var i = 0, r; i < 16; i++) {
28 if ((i & 0x03) === 0) r = Math.random() * 0x100000000;
29 rnds[i] = r >>> ((i & 0x03) << 3) & 0xff;