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- // Unique ID creation requires a high quality random # generator. In the
- // browser this is a little complicated due to unknown quality of Math.random()
- // and inconsistent support for the `crypto` API. We do the best we can via
- // feature-detection
-
- // getRandomValues needs to be invoked in a context where "this" is a Crypto
- // implementation. Also, find the complete implementation of crypto on IE11.
- var getRandomValues = (typeof(crypto) != 'undefined' && crypto.getRandomValues && crypto.getRandomValues.bind(crypto)) ||
- (typeof(msCrypto) != 'undefined' && typeof window.msCrypto.getRandomValues == 'function' && msCrypto.getRandomValues.bind(msCrypto));
-
- if (getRandomValues) {
- // WHATWG crypto RNG - http://wiki.whatwg.org/wiki/Crypto
- var rnds8 = new Uint8Array(16); // eslint-disable-line no-undef
-
- module.exports = function whatwgRNG() {
- getRandomValues(rnds8);
- return rnds8;
- };
- } else {
- // Math.random()-based (RNG)
- //
- // If all else fails, use Math.random(). It's fast, but is of unspecified
- // quality.
- var rnds = new Array(16);
-
- module.exports = function mathRNG() {
- for (var i = 0, r; i < 16; i++) {
- if ((i & 0x03) === 0) r = Math.random() * 0x100000000;
- rnds[i] = r >>> ((i & 0x03) << 3) & 0xff;
- }
-
- return rnds;
- };
- }
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