#!/usr/bin/env node

'use strict'

const HKDF = require('node-hkdf-sync')

const label = process.argv[2]
const masterSeedHex = process.argv[3].trim()

if (process.argv.length !== 4) {
  console.log('hdkf <label> <masterKey>')
  console.log('masterKey should be in hex encoding.')
  process.exit(3)
}

const masterSeed = new Buffer(masterSeedHex, 'hex')
const hkdf = new HKDF('sha256', 'lamassu-server-salt', masterSeed)
console.log(hkdf.derive(label, 32).toString('hex'))