flanker

# decode rails session
def verify_and_decrypt_session_cookie(session_value, secret_key_base = Rails.application.secret_key_base)
  serializer = ActiveSupport::MessageEncryptor::NullSerializer
  key_generator = ActiveSupport::KeyGenerator.new(secret_key_base, iterations: 1000)
  secret = key_generator.generate_key('encrypted cookie', 32)
  sign_secret = key_generator.generate_key("signed encrypted cookie")
  encryptor = ActiveSupport::MessageEncryptor.new(secret, sign_secret, cipher: "aes-256-cbc", serializer: serializer)
  encryptor.decrypt_and_verify(CGI::unescape session_value)
end