HR/Crypter

'use strict'
/**
 * MasterPass.js
 * MasterPass functionality
 ******************************/

const crypto = require('./crypto'),
  keytar = require('keytar'),
  SERVICE = 'Crypter',
  ACCOUNT = 'MasterPass'

// TODO: Make independent from global obj! use param instead

exports.init = async () => {
  const masterpass = await keytar.getPassword(SERVICE, ACCOUNT)
  if (!masterpass) return false
  const mpk = await crypto.deriveKey(masterpass, global.creds.mpsalt)
  return mpk
}

exports.save = masterpass => keytar.setPassword(SERVICE, ACCOUNT, masterpass)

// Check MasterPass
exports.check = masterpass => {
  return new Promise((resolve, reject) => {
    // deriveKey using the salt originally used to generate the
    // MasterPassKey
    crypto
      .deriveKey(masterpass, global.creds.mpsalt)
      .then(mpk => {
        // generate the hash for the MasterPassKey
        return crypto.genPassHash(mpk.key, global.creds.mpksalt)
      })
      .then(mpk => {
        // check if MasterPassKey hash is equal to the MasterPassKey hash in mdb
        // Use timingSafeEqual to protect against timing attacks
        const match = crypto.timingSafeEqual(global.creds.mpkhash, mpk.hash)
        // return the match and derived key
        resolve({ match, key: mpk.key })
      })
      .catch(err => {
        reject(err)
      })
  })
}

// Set MasterPass
exports.set = masterpass => {
  return new Promise((resolve, reject) => {
    // Derive the MasterPassKey from the supplied masterpass
    crypto
      .deriveKey(masterpass, null)
      .then(mp => exports.save(masterpass).then(() => mp))
      .then(mp => {
        // Save the salt used to generate the MasterPassKey
        global.creds.mpsalt = mp.salt
        // generate the hash for the MasterPassKey
        return crypto.genPassHash(mp.key, null)
      })
      .then(mpk => {
        // Save the salt used to generate the masterpass
        global.creds.mpkhash = mpk.hash
        global.creds.mpksalt = mpk.salt
        // return the derived mpkey
        resolve(mpk.key)
      })
      .catch(err => {
        // reject if error occurs
        reject(err)
      })
  })
}