feat: implement getRandomValues and randomUUID - resolves #213 and #214

Author: markhughes

index.js

@@ -1,6 +1,29 @@
 'use strict'
 
 exports.randomBytes = exports.rng = exports.pseudoRandomBytes = exports.prng = require('randombytes')
+
+exports.getRandomValues = function (abv) {
+  var l = abv.length
+  while (l--) {
+    var bytes = exports.randomBytes(7)
+    var randomFloat = (bytes[0] % 32) / 32
+
+    for (var i = 0; i < bytes.length; i++) {
+      var byte = bytes[i]
+      randomFloat = (randomFloat + byte) / 256
+    }
+
+    abv[l] = Math.floor(randomFloat * 256)
+  }
+  return abv
+}
+
+exports.randomUUID = function () {
+  return '10000000-1000-4000-8000-100000000000'.replace(/[018]/g, function (c) {
+    return  (c ^ (exports.getRandomValues(new Uint8Array(1))[0] & (15 >> (c / 4)))).toString(16)
+  })
+}
+
 exports.createHash = exports.Hash = require('create-hash')
 exports.createHmac = exports.Hmac = require('create-hmac')
 

test/index.js

@@ -5,6 +5,9 @@ if (!process.browser) {
 }
 
 require('./pbkdf2')
+
+require('./random-uuid')
+
 try {
   require('randombytes')(8)
   require('./ecdh')

test/random-uuid.js

@@ -0,0 +1,17 @@
+var test = require('tape')
+var crypto = require('../')
+
+test('randomuuid', function (t) {
+  var uuid1 = crypto.randomUUID()
+  var uuid2 = crypto.randomUUID()
+
+  t.ok(uuid1, 'first uuid truthy')
+  t.ok(uuid2, 'second uuid truthy')
+
+  t.notEqual(uuid1, uuid2, 'consecutive uuid\'s do not match')
+
+  t.match(uuid1, /^[0-9A-F]{8}-[0-9A-F]{4}-[4][0-9A-F]{3}-[89AB][0-9A-F]{3}-[0-9A-F]{12}$/i, 'first uuid matches uuid regex')
+  t.match(uuid2, /^[0-9A-F]{8}-[0-9A-F]{4}-[4][0-9A-F]{3}-[89AB][0-9A-F]{3}-[0-9A-F]{12}$/i, 'second uuid matches uuid regex')
+
+  t.end()
+})