NACL SecretBox example (safely symm encrypt/decrypt)

secretbox-example.js

const nacl = require('tweetnacl')
nacl.util = require('tweetnacl-util')
const crypto = require('crypto')
const key64 = '4jYJgju0rVSVSBBhihogB7dIW5UIEDhPHxwl+WJlfOk='
const keyBuff = Buffer.from(key64, 'base64')

/* -------------- */
/*    Build jwt   */
/* -------------- */

const nonceBuff = crypto.randomBytes(24)
const nonce64 = nonceBuff.toString('base64')

const args = process.argv
args.shift()
args.shift()
const message = args.length ? args.join(' ') : 'This is a super secret message.'
const messageBuff = new Buffer(message)

const box = nacl.secretbox(
  messageBuff,
  nonceBuff,
  keyBuff)
const box64 = nacl.util.encodeBase64(box)
const msg = {box64, nonce64}
console.log(msg)

/* -------------- */
/*  Get from msg  */
/* -------------- */

const msgNonceBuff = nacl.util.decodeBase64(msg.nonce64)
const msgBoxBuff = nacl.util.decodeBase64(msg.box64)
const msgMessageBuff = nacl.secretbox.open(msgBoxBuff, msgNonceBuff, keyBuff)
const msgMessage = nacl.util.encodeUTF8(msgMessageBuff)
console.log(msgMessage)

/* -------------- */
/* Create new key */
/* -------------- */

console.log('')
console.log('POC Successful! Generating new keys for future use:')
console.log('')

console.log(crypto.randomBytes(32).toString('base64'))
console.log(crypto.randomBytes(32).toString('base64'))
console.log(crypto.randomBytes(32).toString('base64'))