Class: ActiveRecord::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/symmetric_encryption/extensions/active_record/base.rb

Class Method Summary collapse

Class Method Details

.attr_encrypted(*params) ⇒ Object

Much lighter weight encryption for Rails attributes matching the attr_encrypted interface using SymmetricEncryption

The regular attr_encrypted gem uses Encryptor that adds encryption to every Ruby object which is a complete overkill for this simple use-case

Params:

  • symbolic names of each method to create which has a corresponding method already defined in rails starting with: encrypted_

  • Followed by an option hash:

    :marshal => Whether this element should be converted to YAML before encryption
            true or false
            Default: false



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# File 'lib/symmetric_encryption/extensions/active_record/base.rb', line 19

def attr_encrypted(*params)
  # Ensure ActiveRecord has created all its methods first
  # Ignore failures since the table may not yet actually exist
  define_attribute_methods rescue nil

  options = params.last.is_a?(Hash) ? params.pop : {}

  params.each do |attribute|
    # Generate unencrypted attribute with getter and setter
    class_eval(<<-UNENCRYPTED, __FILE__, __LINE__ + 1)
      # Returns the decrypted value for the encrypted attribute
      # 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 #{attribute}
        if @stored_encrypted_#{attribute} != self.encrypted_#{attribute}
          @#{attribute} = ::SymmetricEncryption.decrypt(self.encrypted_#{attribute})
          @stored_encrypted_#{attribute} = self.encrypted_#{attribute}
        end
        @#{attribute}
      end

      # Set the un-encrypted attribute
      # Also updates the encrypted field with the encrypted value
      def #{attribute}=(value)
        self.encrypted_#{attribute} = @stored_encrypted_#{attribute} = ::SymmetricEncryption.encrypt(value#{".to_yaml" if options[:marshal]})
        @#{attribute} = value
      end
    UNENCRYPTED

    encrypted_attributes[attribute.to_sym] = "encrypted_#{attribute}".to_sym
  end
end

.encrypted_attribute?(attribute) ⇒ Boolean

Returns whether an attribute has been configured to be encrypted

Example

class User < ActiveRecord::Base
  attr_accessor :name
  attr_encrypted :email
end

User.encrypted_attribute?(:name) # false
User.encrypted_attribute?(:email) # true

Returns:

  • (Boolean) 


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# File 'lib/symmetric_encryption/extensions/active_record/base.rb', line 89

def encrypted_attribute?(attribute)
  encrypted_keys.include?(attribute)
end

.encrypted_attributes ⇒ Object

Contains a hash of encrypted attributes with virtual attribute names as keys and real attribute names as values

Example

class User < ActiveRecord::Base
  attr_encrypted :email
end

User.encrypted_attributes # { :email => :encrypted_email }



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# File 'lib/symmetric_encryption/extensions/active_record/base.rb', line 62

def encrypted_attributes
  @encrypted_attributes ||= superclass.respond_to?(:encrypted_attributes) ? superclass.encrypted_attributes.dup : {}
end

.encrypted_column?(attribute) ⇒ Boolean

Returns whether the attribute is the database column to hold the encrypted data for a matching encrypted attribute

Example

class User < ActiveRecord::Base
  attr_accessor :name
  attr_encrypted :email
end

User.encrypted_column?(:encrypted_name) # false
User.encrypted_column?(:encrypted_email) # true

Returns:

  • (Boolean) 


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# File 'lib/symmetric_encryption/extensions/active_record/base.rb', line 105

def encrypted_column?(attribute)
  encrypted_columns.include?(attribute)
end

.encrypted_columns ⇒ Object

Return the name of all encrypted columns as an Array of symbols Example: [:encrypted_email, :encrypted_password]



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# File 'lib/symmetric_encryption/extensions/active_record/base.rb', line 74

def encrypted_columns
  @encrypted_columns ||= encrypted_attributes.values
end

.encrypted_keys ⇒ Object

Return the name of all encrypted virtual attributes as an Array of symbols Example: [:email, :password]



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# File 'lib/symmetric_encryption/extensions/active_record/base.rb', line 68

def encrypted_keys
  @encrypted_keys ||= encrypted_attributes.keys
end