Automatically expand encrypted arguments to support querying both encrypted and unencrypted data

Active Record Encryption supports querying the db using deterministic attributes. For example:

Contact.find_by(email_address: "jorge@hey.com")

The value “jorge@hey.com” will get encrypted automatically to perform the query. But there is a problem while the data is being encrypted. This won't work. During that time, you need these queries to be:

Contact.find_by(email_address: [ "jorge@hey.com", "<encrypted jorge@hey.com>" ])

This patches ActiveRecord to support this automatically. It addresses both:

  • ActiveRecord::Base: Used in +Contact.find_by_email_address(…)+

  • ActiveRecord::Relation: Used in +Contact.internal.find_by_email_address(…)+

ActiveRecord::Base relies on ActiveRecord::Relation (ActiveRecord::QueryMethods) but it does some prepared statements caching. That's why we need to intercept ActiveRecord::Base as soon as it's invoked (so that the proper prepared statement is cached).

When modifying this file run performance tests in test/performance/extended_deterministic_queries_performance_test.rb to

make sure performance overhead is acceptable.

We will extend this to support previous “encryption context” versions in future iterations

@TODO Experimental. Support for every kind of query is pending @TODO It should not patch anything if not needed (no previous schemes or no support for previous encryption schemes)

Namespace

Module

Class

Methods

Constants

MigrationProxy = Struct.new(:name, :version, :filename, :scope) do def initialize(name, version, filename, scope) super @migration = nil end def basename File.basename(filename) end delegate :migrate, :announce, :write, :disable_ddl_transaction, to: :migration private def migration @migration ||= load_migration end def load_migration Object.send(:remove_const, name) rescue nil load(File.expand_path(filename)) name.constantize.new(name, version) end end
 

MigrationProxy is used to defer loading of the actual migration classes until they are needed

Point = Struct.new(:x, :y)
 
UnknownAttributeError = ActiveModel::UnknownAttributeError
 

Raised when unknown attributes are supplied via mass assignment.

class Person
  include ActiveModel::AttributeAssignment
  include ActiveModel::Validations
end

person = Person.new
person.assign_attributes(name: 'Gorby')
# => ActiveModel::UnknownAttributeError: unknown attribute 'name' for Person.

Class Public methods

gem_version()

Returns the version of the currently loaded Active Record as a Gem::Version

# File activerecord/lib/active_record/gem_version.rb, line 5
def self.gem_version
  Gem::Version.new VERSION::STRING
end

version()

Returns the version of the currently loaded ActiveRecord as a Gem::Version

# File activerecord/lib/active_record/version.rb, line 7
def self.version
  gem_version
end