pasticciotto - Polymorphic VM and PoliCTF '17 reversing challenge

项目说明

Pasticciotto

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![Pasticciotto]

What is this?

Pasticciotto is a machine which can be used to obfuscate code. It was de for the PoliCTF 17 as a re challenge.

The key feature is its opcode "shuffling": their actual are determined by a password. (More in IMPLEMENTATION.md)

I wanted to experiment with since it was a topic that caught my attention while re challenges for CTFs. So, I decided to write one from scratch in order to understand better how instruction set architectures are implemented!

The design and the implementation behind Pasticciotto are not state-of-the-art but hey, it works! :D

Why "Pasticciotto"?

In Italian, "Pasticciotto" has two meanings!

The first one is "little mess" which perfectly describes how I put up this project. The second one is a typical dessert from Southern Italy, Salento! It's filled with cream! Yum!

Quick start

You can use pasticciotto in your own binary! It's easy to do!

Assemble!

Let's say you want to run this C code into pasticciotto:

It can be translated into this pasticciotto's assembly snippet:

Let's assemble it with key HelloWorld:

Now we are ready to embed the VM in a .c program:

That's it!

Accessing to the VM's sections and registers

The VM data / code / stack sections are represented through the object. It is defined here. The registers are in a uint16_t array in the VM object defined here.

What about the challenge?

You can find the client and the ser the polictf/ directory. I have also written a small writeup. Check it out!

Compiling

Requisites

1. CMake

Quick start

mkdir build
cd build
cmake ..
# or, if you want debug info:
# cmake -DPASTICCIOTTO_DEBUG=On ..
make

CMake targets

| Target name | Description |
| ----------------------- | -------------------------------------- |
| pasticciotto-emulator | Builds pasticciotto's emulator |
| polictf | Builds PoliCTF's client and server |
| polictf-client | Builds PoliCTF's client |
| polictf-server | Builds PoliCTF's server |
| pasticciotto-tests | Builds pasticciotto's test executable. |

If the PASTICCIOTTO_DEBUG flag is passed to cmake during the configuration phase, the targets will be compiled with debug symbols and additional debug information.

Implementation details

Check out the file IMPLEMENTATION.MD to understand how the and which operations it can do! Watch out for some spoilers if you haven't completed the challenge though!

Contributions

I wanted to polish the VM even more but I haven't got the time to do it. There are rough edges for sure!

Any contribution is very welcome! Feel free to open issues and pull requests!

License

[Pasticciotto]: ./res/pasticciotto.png
[TravisCI]:

项目信息

开发语言：C++

Star 数：76

技术要点

该项目属于CTF思路方向的开源资源，代码结构清晰，适合安全研究人员学习参考。项目围绕Polymorphic VM and PoliCTF '17 reversing challenge.展开，提供了可运行的实现，对理解相关安全机制、工具原理与攻防技术具有较高的研究价值。

从技术实现角度看，此类项目的核心在于对底层原理的深入理解与工程化落地。开发者在研究过程中可以结合官方文档与社区讨论，梳理项目的初始化流程、核心模块职责与数据流转，逐步掌握其中的技术细节与设计思路。

使用与学习建议

1. 下载源码压缩包，解压到本地环境。

2. 根据项目类型准备对应的运行环境与依赖。

3. 按照 README 中的步骤完成配置与部署。

4. 在隔离的测试环境中运行验证，避免影响生产系统。

免责声明

本资源来源于开源社区，仅供安全研究、技术学习与合法授权范围内的攻防演练使用，请勿用于任何非法或侵害他人权益的用途。使用本项目产生的一切后果由使用者自行承担。