How to generate a random 32-byte Javascript token?

Question

I need to generate a random alphanumeric string that needs to be 32 bytes. Is there any direct function to do this?

Answer 1

Using Crypto and a typed array

function random32bit() {
  let u = new Uint32Array(1);
  window.crypto.getRandomValues(u);
  let str = u[0].toString(16).toUpperCase();
  return '00000000'.slice(str.length) + str;
}

Answer 2

Here has a very good discussion about UUID

And here is an example you can find on the first link:

function uuid() {
  return ([1e7]+-1e3+-4e3+-8e3+-1e11).replace(/[018]/g, c => (c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16));
}

console.log(uuid());

Using Math,

function uuid() {
  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
    var r = Math.random() * 16 | 0, v = c == 'x' ? r : (r & 0x3 | 0x8);
    return v.toString(16);
  });
}

console.log(uuid())