Snippets of Javascript.

nonce.js

'use strict';

/* node.js nonce: crypto-quality random session key (filename safe base64, rfc4648) */

const btoa   = require( 'btoa' );
const crypto = require( 'crypto' );

function nonce( length ) {
  const rndLen = 1+(( (length)+(length<<1) +3)>>2);
  const randomArray = crypto.randomBytes( rndLen );
  const b64         = btoa( String.fromCharCode.apply( null, randomArray ) );

  return b64
      .replace( /[\/]/g, '_' )
      .replace( /[+]/g, '-' )
      .replace( /[=]/g, '' )
      .substring( 0, length );
}

module.exports = nonce;