The ActiveSupport::SecureCompareRotator is a wrapper around ActiveSupport::SecurityUtils.secure_compare and allows you to rotate a previously defined value to a new one.

It can be used as follow:

rotator = ActiveSupport::SecureCompareRotator.new('new_production_value')
rotator.rotate('previous_production_value')
rotator.secure_compare!('previous_production_value')

One real use case example would be to rotate a basic auth credentials:

class MyController < ApplicationController
  def authenticate_request
    rotator = ActiveSupport::SecureCompareRotator.new('new_password')
    rotator.rotate('old_password')

    authenticate_or_request_with_http_basic do |username, password|
      rotator.secure_compare!(password)
    rescue ActiveSupport::SecureCompareRotator::InvalidMatch
      false
    end
  end
end

Methods

Included Modules

Constants

InvalidMatch = Class.new(StandardError)
 

Class Public methods

new(value, **_options)

# File activesupport/lib/active_support/secure_compare_rotator.rb, line 36
def initialize(value, **_options)
  @value = value
end

Instance Public methods

secure_compare!(other_value, on_rotation: @on_rotation)

# File activesupport/lib/active_support/secure_compare_rotator.rb, line 40
def secure_compare!(other_value, on_rotation: @on_rotation)
  secure_compare(@value, other_value) ||
    run_rotations(on_rotation) { |wrapper| wrapper.secure_compare!(other_value) } ||
    raise(InvalidMatch)
end