yael-autoencrypt

Encrypt and write a file during development, then read and decrypt it during production.

Installation

npm install yael-autoencrypt

Use Case

Say you have a config file called 'secrets.txt' with all the secret API keys for all your server application. You need to distribute the secrets to your server via source control, possibly because you have a git 'push' based deploy mechanism, or you just have so many secrets that using separate environment variables for each API key is too much work. However, you don't and want those secrets stored in the clear, either in source control or on your server, because your server or source code repo could get hacked. Rather than add another step into your build chain, this library helps you encrypt your secrets in a file AND keep that file up-to-date.

Example

This example code lets you keep a master plaintext_file on your development box. (Be sure to add it to .gitignore so you don't ever upload it by mistake!) When your application runs, it will automatically save an encrypted version of the file as encrypted_file, which you can add to source control. On the production server or on other developer's boxes where plaintext_file is absent, it will notice that and try to use encrypted_file instead. From the code's perspective the library usage is the exact same, so the code is identical in both cases.

autoencrypt = require('yael-autoencrypt');
config = autoencrypt({
  password: process.env.CONFIG_PASSWORD,
  plaintext_file: 'secrets.txt',
  encrypted_file: 'encrypted.txt'
})
console.log config

Whenever you run your application on a computer where plaintext_file is present, it will check that the contents match the decrypted contents of encrypted_file. If the contents differ, it will overwrite encrypted_file with the updated content.

Caching and using multiple files

For convenience, the module caches the password, plaintext_file, and encrypted_file values in memory. This means that once you have called autoencrypt with the options, elsewhere in your code you can leave out the options:

autoencrypt = require('yael-autoencrypt')
config = autoencrypt()

This makes sense if you have one central encrypted config file. However this causes a problem if you need to work with multiple encrypted config files. To get around this, you can add a cache: false option:

autoencrypt = require('yael-autoencrypt');
config = autoencrypt({
  cache: false,
  password: process.env.CONFIG_PASSWORD2,
  plaintext_file: 'other-secrets.txt',
  encrypted_file: 'other-encrypted.txt'
})