EncryptableAttributes

With the encryptable_attributes gem, you transparently encrypt and decrypt attributes of an ActiveRecord model. It uses ActiveSupport::MessageEncryptor to encrypt and decrypt values and provides a simple class-level DSL for configuration.

Add this line to your application's Gemfile:

gem 'encryptable_attributes'

And then execute:

$ bundle

Or install it yourself as:

$ gem install encryptable_attributes

Consider a simple ActiveRecord model Message with a title and a body field. To store those attributes' values encrypted, use the following code snippet.

class Message < ActiveRecord::Base
  include EncryptableAttributes::Base
  
  secure_key ENV.fetch('SECRET_KEY')
  secure_attrs :title, :body
end

ActiveRecord models use an attributes hash internally to keep attributes. EncryptablesAttributes overrides the accessor methods for the corresponding attributes and encrypts given values before storing them in the attributes hash and decrypts them when reading them from the attributes hash.

In addition to setting the encryption key statically as shown in the example above, you can also read the key dynamically per model instance via a method call. It looks like this.

class Message < ActiveRecord::Base
  include EncryptableAttributes::Base
  
  secure_key :individual_message_key
  secure_attrs :title, :body
  
  private

    # Use this to build a message key from other model attributes
    # or to set it from content fed from outside.
    def individual_message_key
      'secret'
    end
end

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.

Bug reports and pull requests are welcome on GitHub at https://github.com/nsommer/encryptable_attributes.

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