Typescript nodejs stdlib enc/dec sample

enc_dec.ts

import * as crypto from 'crypto'
import assert from 'assert'

const ivKey = 'randomString1-fah3f;aklajr'
const initialVec = Buffer.alloc(16, 0)
crypto
  .createHash('sha256')
  .update(ivKey)
  .digest().copy(initialVec)

const key = (passphrase: string) => crypto
  .createHash('sha256')
  .update(passphrase)
  .digest()

const plainEncoding = 'utf8'
const encryptedEncoding = 'base64'
export function enc (plain: string, passphrase: string) {
  const salt = crypto.randomBytes(3).toString('base64')
  const cipher = crypto.createCipheriv('aes256', key(passphrase), initialVec)
  return cipher.update(salt + plain, plainEncoding, encryptedEncoding) + cipher.final(encryptedEncoding)
}
export function dec (encrypted: string, passphrase: string) {
  const decipher = crypto.createDecipheriv('aes256', key(passphrase), initialVec)
  const ret = decipher.update(encrypted, encryptedEncoding, plainEncoding) + decipher.final(plainEncoding)
  return ret.slice(4)
}

function test (msg: string) {
  const passphrase = 'pass'
  const encrypted = [enc(msg, passphrase), enc(msg, passphrase)]
  console.log(encrypted)
  assert.strict.notEqual(encrypted[0], encrypted[1])
  const decrypted = encrypted.map(x => dec(x, passphrase))
  console.log(msg, decrypted)
  assert.strict.equal(decrypted[0], decrypted[1])
}
test('hogehogefugafuga')