Encryption and Decryption in Node.js v6.9.4 for buffer data

crypto.js

'use strict'

var crypto = require('crypto')
var Promise = require('bluebird')

module.exports = {
  encrypt: encrypt,
  decrypt: decrypt
}

/**
 * @function encrypt Encrypt the buffer data
 * @param {Buffer} buffer - Represent the buffer data which needs to be encrypted
 * @param {Object} config - Contains the algorithm and password used for encryption
 * @return {Promise<Buffer>} - Promise to the encrypted buffer
 */
function encrypt (buffer, config) {
  return new Promise((resolve, reject) => {
    try {
      var cipher = crypto.createCipher(config.algorithm, config.password)
      var crypted = cipher.update(buffer)
      crypted = Buffer.concat([ crypted, cipher.final() ])
      resolve(crypted)
    } catch (err) {
      reject(err)
    }
  })
}

/**
 * @function decrypt Decrypt the buffer data
 * @param {Buffer} buffer - Represent the buffer data which needs to be decrypted
 * @param {Object} config - Contains the algorithm and password used for decryption
 * @return {Promise<Buffer>} - Promise to the decrypted buffer
 */
function decrypt (buffer, config) {
  return new Promise((resolve, reject) => {
    try {
      var decipher = crypto.createDecipher(config.algorithm, config.password)
      var decrypted = decipher.update(buffer)
      decrypted = Buffer.concat([ decrypted, decipher.final() ])
      resolve(decrypted)
    } catch (err) {
      reject(err)
    }
  })
}