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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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