A really tiny JSON encrypted-and-compressed datastore

tinystore.js

// Dead simple compressed and encrypted datastore
var crypto = require('crypto');
var zlib   = require('zlib');
var fs     = require('fs');
var stream = require('stream');

// Load the session store from #{filename} and decrypt it using #{method} with
// the key #{key}.
// @param filename {String} filename
// @param key the encryption key, can be a string or buffer
// @param method (default = "aes-256-cbc") the encryption method to use
// @returns {Stream} a stream containing your JSON data
module.exports.load = function(filename, key, method) {
  method = method || 'aes-256-cbc';
  var decipher = crypto.createDecipher(method, key);
  var file = fs.createReadStream(filename);
  var unpack = zlib.createGunzip();

  return file.pipe(unpack).pipe(decipher);
};

// Save the given data into filename and encrypt / compress it.
// @param data {Object} JSON-serializable data
// @param filename {String} filename
// @param key the encryption key, can be a string or buffer
// @param method (default = "aes-256-cbc") the encryption method to use
// @returns {Writable Stream} the file stream
module.exports.save = function(data, filename, key, method) {
  method = method || 'aes-256-cbc';

  var cipher = crypto.createCipher(method, key);
  var file = fs.createWriteStream(filename);
  var pack = zlib.createGzip();
  var s = new stream.Readable();

  data = JSON.stringify(data);

  s.push(data);
  s.push(null);

  return s.pipe(cipher).pipe(pack).pipe(file);
};