react-native-secure-random

Synchronous and asynchronous native random number provider for iOS and Android.

react-native-secure-random bridges iOS's SecRandomCopyBytes and Android's java.security.SecureRandom to provide secure random bytes to react native apps.

Getting started

$ npm install react-native-secure-random --save

$3

$ react-native link react-native-secure-random

Usage

To obtain bytes asynchronously use randomBytesAsync.

``javascript
import { randomBytesAsync } from 'react-native-secure-random'

randomBytesAsync(10).then(bytes => {
// bytes is an Uint8Array of 10 elements.
})
`

In order to support legacy code that needs randomness synchronously you can use the synchronous version:

`javascript
import { randomBytesSync } from 'react-native-secure-random'

const bytes = randomBytesSync(10) // bytes is an array of 10 numbers.
`

Note that randomBytesSync relies on having a small pool which it fills when the package is initialized, and refills when it starts to run low. That means that it is possible to deplete the pool faster than you fill it if you request a lot of bytes fast. An exception will be thrown in that case.

The pool will be re-filled every time bytes are taken out of it. If you want to manually refill or be sure that the pool is filled you can call fillPool() yourself:

`javascript
import { fillPool } from 'react-native-secure-random'
await fillPool() // Which will return a promise fullfilled once the pool is full.
``

LICENSE

The MIT License

Copyright (c) 2020 Crypho AS.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.