Module: SymmetricEncryption::Generator

Defined in:
lib/symmetric_encryption/generator.rb

Class Method Summary collapse

Class Method Details

.generate_decrypted_accessors(model, decrypted_name, encrypted_name, options) ⇒ Object

Common internal method for generating accessors for decrypted accessors Primarily used by extensions

Raises:

  • (ArgumentError) 


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# File 'lib/symmetric_encryption/generator.rb', line 5

def self.generate_decrypted_accessors(model, decrypted_name, encrypted_name, options)
  options   = options.dup
  random_iv = options.delete(:random_iv) || false
  compress  = options.delete(:compress) || false
  type      = options.delete(:type) || :string

  raise(ArgumentError, "SymmetricEncryption Invalid options #{options.inspect} when encrypting '#{decrypted_name}'") if options.size > 0
  raise(ArgumentError, "Invalid type: #{type.inspect}. Valid types: #{SymmetricEncryption::COERCION_TYPES.inspect}") unless SymmetricEncryption::COERCION_TYPES.include?(type)

  if model.const_defined?(:EncryptedAttributes, _search_ancestors = false)
    mod = model.const_get(:EncryptedAttributes)
  else
    mod = model.const_set(:EncryptedAttributes, Module.new)
    model.send(:include, mod)
  end

  # Generate getter and setter methods
  mod.module_eval(<<-EOS, __FILE__, __LINE__ + 1)
    # Set the un-encrypted field
    # Also updates the encrypted field with the encrypted value
    # Freeze the decrypted field value so that it is not modified directly
    def #{decrypted_name}=(value)
      v = SymmetricEncryption::coerce(value, :#{type})
      self.#{encrypted_name} = @stored_#{encrypted_name} = ::SymmetricEncryption.encrypt(v,#{random_iv},#{compress},:#{type})
      @#{decrypted_name} = v.freeze
    end

    # Returns the decrypted value for the encrypted field
    # The decrypted value is cached and is only decrypted if the encrypted value has changed
    # If this method is not called, then the encrypted value is never decrypted
    def #{decrypted_name}
      if @stored_#{encrypted_name} != self.#{encrypted_name}
        @#{decrypted_name} = ::SymmetricEncryption.decrypt(self.#{encrypted_name},version=nil,:#{type}).freeze
        @stored_#{encrypted_name} = self.#{encrypted_name}
      end
      @#{decrypted_name}
    end

  EOS
end