Keychain

cypher.rb

require 'gibberish'

class Keychain
  module Cipher
    @@secret = ""

    def self.configuration
      yield self
    end

    def self.secret= secret
      @@secret = secret
    end

    def self.secret
      @@secret
    end

    def self.encrypt information
      @@cipher ||= Gibberish::AES.new @@secret
      @@cipher.enc information
    end

    def self.decrypt information
      @@cipher.dec information
    end
  end
end

cypher_spec.rb

require_relative '../keychain/cipher'

describe Keychain::Cipher do
  it "encrypts a piece of information" do
    encrypted_text = Keychain::Cipher.encrypt 'some text'
    encrypted_text.should_not == 'some text'
    decrypted_text = Keychain::Cipher.decrypt encrypted_text
    decrypted_text.should == 'some text'
  end

  it "secret should be configurable" do
    Keychain::Cipher.configuration do |config|
      config.secret = "some other secret"
    end

    Keychain::Cipher.secret.should == "some other secret"
  end
end

key.rb

module Mixin
  module Key
    def self.included klass
      klass.extend ClassMethods
    end

    def cipher
      Keychain::Cipher
    end

    def will_lock
      @@will_unlock
    end

    def lock
      cipher_direction :encrypt
    end

    def unlock
      cipher_direction :decrypt
    end

    module ClassMethods
      def attr_locks *syms
        syms.each do |sym|
          attr_accessor sym
        end
        Key.class_variable_set :@@will_unlock, syms
      end
    end

  private
    def cipher_direction direction
      @@will_unlock.each do |sym|
        value = instance_variable_get "@#{sym}"
        processed_value = cipher.method(direction).call value
        instance_variable_set "@#{sym}", processed_value
      end
    end
  end
end

key_spec.rb

require_relative '../keychain/key'
require_relative '../keychain/cipher'

class KeyStore
  include Mixin::Key

  attr_locks :login, :password
end

describe Mixin::Key do
  let(:key) { KeyStore.new }

  before do 
    key.login = "john@example.com"
    key.password = "abc123"
  end

  it "has fields to lock" do  
    key.will_lock.should == [:login, :password]
  end

  it "unlocks itself" do
    key.lock
    key.login.should_not match "john@example.com"

    key.unlock
    key.login.should match "john@example.com"
  end
end