class ActiveSupport::MessageEncryptor

def initialize(secret, *signature_key_or_options)

* :serializer - Object serializer to use. Default is +Marshal+.
* :digest - String of digest to use for signing. Default is +SHA1+.
OpenSSL::Cipher.ciphers. Default is 'aes-256-cbc'.
* :cipher - Cipher to use. Can be any cipher returned by
Options:

derivation function.
key by using ActiveSupport::KeyGenerator or a similar key
bits. If you are using a user-entered secret, you can generate a suitable
the cipher key size. For the default 'aes-256-cbc' cipher, this is 256
Initialize a new MessageEncryptor. +secret+ must be at least as long as 
def initialize(secret, *signature_key_or_options)
  options = signature_key_or_options.extract_options!
  sign_secret = signature_key_or_options.first
  @secret = secret
  @sign_secret = sign_secret
  @cipher = options[:cipher] || 'aes-256-cbc'
  @verifier = MessageVerifier.new(@sign_secret || @secret, digest: options[:digest] || 'SHA1', serializer: NullSerializer)
  @serializer = options[:serializer] || Marshal
end