在网上找到了一段代码：

message = CGI.unescape("VXVHWGQra3JpclBiSkpZWW8yMTRzWUVQL0tYajNXMXUyZzFNcFlNcjVVdloxMnhWOFRvdGdPcXhJV256ZEx3MzFkbWhWbG1SSmMzK0NqNHZnS1BPKytTWVRHRFhjN1hWOHlmc3VnNk5rOXRQNzdobnFlOFhPT25NSTVlT3d2QkZiQktvRU5jMWlNdUZKWjFNL0lBbE9WSEVkcXFoMnUzNGtBa0kzRHJMWFd6VEIreHVjVlhSMThxZEQ2VmdKRmtrWXFKQlI4d1k3QU9EbnViVXR2ZWZxZz09LS00bUd0K0g3UTM0RkY1THkrZUt6Slh3PT0%3D--d9847b41c72ceed939cb58acb6cb989d58602d6e")

config = Rails.application.config

key_generator = ActiveSupport::KeyGenerator.new(
  config.secret_key_base, iterations: 1000
)

secret = key_generator.generate_key(
  config.action_dispatch.encrypted_cookie_salt
)

sign_secret = key_generator.generate_key(
  config.action_dispatch.encrypted_signed_cookie_salt
)

encryptor = ActiveSupport::MessageEncryptor.new(
  secret, sign_secret
)

encryptor.decrypt_and_verify(message)

但不知该如何运行，是要放到该 app 的工作目录下，还是任意一个地方，需要require什么吗？