window.crypto.getRandomValues or window.msCrypto.getRandomValues or require('crypto').randomBytes or an Error.

var getRandomValues = require('get-random-values');

var array = new Uint32Array(10);
getRandomValues(array);
// => [
// =>   183,
// =>   76,
// =>   18,
// =>   177,
// =>   73,
// =>   9,
// =>   50,
// =>   248,
// =>   216,
// =>   104
// => ]

$ npm install get-random-values

var getRandomValues = require('get-random-values');

Fills integer-based TypedArray buf with cryptographically random numbers. Checks for and uses the first of the following:

• window.crypto.getRandomValues
• window.msCrypto.getRandomValues
• Node.js crypto

If none of the above are available, then an Error is thrown.

Throws QuotaExceededError if buf.length > 65536 (even if Node.js crypto, which doesn't have that limit, is being used).

buf must be a Uint8Array if Node.js crypto is used, otherwise a TypeError will be thrown.