class ActionDispatch::Cookies::UpgradeLegacyEncryptedCookieJar

:nodoc:
encrypts and re-saves them using the new key generator to provide a smooth upgrade path.
are both set. It reads legacy cookies signed with the old dummy key generator and
instead of EncryptedCookieJar if config.secret_token and config.secret_key_base
UpgradeLegacyEncryptedCookieJar is used by ActionDispatch::Session::CookieStore

def [](name) 

def [](name)
  if encrypted_or_signed_message = @parent_jar[name]
    decrypt_and_verify(encrypted_or_signed_message) || verify_and_upgrade_legacy_signed_message(name, encrypted_or_signed_message)
  end
end