Diffcrypt

Diffable encrypted files that you can safely commit into your repo.

Installation

Add this line to your application's Gemfile:

gem 'diffcrypt'

And then execute:

$ bundle install

Or install it globally (to use the CLI from any project):

$ gem install diffcrypt

Usage

There are a few ways to use the library, depending on how advanced your use case is.

CLI

The easiest way to get started is to use the CLI.

diffcrypt decrypt -k $(cat test/fixtures/aes-128-gcm.key) test/fixtures/example.yml.enc
diffcrypt encrypt -k $(cat test/fixtures/aes-128-gcm.key) test/fixtures/example.yml

Ruby

A direct API is exposed so Diffcrypt::Encryptor can be used in any ruby project.

NOTE: This API may change any time until v1.0

encryptor = Diffcrypt::Encryptor.new('99e1f86b9e61f24c56ff4108dd415091')
yaml = File.read('test/fixtures/example.yml')
encrypted = encryptor.encrypt(yaml)
File.write('tmp/example.yml.enc', encrypted)

encryptor = Diffcrypt::Encryptor.new('99e1f86b9e61f24c56ff4108dd415091')
yaml = File.read('test/fixtures/example.yml.enc')
config = YAML.safe_load(encryptor.decrypt(yaml))

Ruby on Rails

Currently there is not native support for rails, but ActiveSupport can be monkeypatched to override the built in encrypter. All existing rails credentials:edit also work with this method.

# config/application.rb
module Rails
  class Application
    include Diffcrypt::Rails::ApplicationHelper
  end
end

Converting between ciphers

Sometimes you may want to rotate the cipher used on a file. You can do this programmatically using the ruby code above, or you can also chain the CLI commands like so:

diffcrypt decrypt -k $(cat test/fixtures/aes-128-gcm.key) test/fixtures/example.yml.enc > test/fixtures/example.128.yml \
&& diffcrypt encrypt --cipher aes-256-gcm -k $(cat test/fixtures/aes-256-gcm.key) test/fixtures/example.128.yml > test/fixtures/example.256.yml.enc && rm test/fixtures/example.128.yml

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/diffcrypt/diffcrypt-ruby.

License

The gem is available as open source under the terms of the MIT License.