pakala - Offensive vulnerability scanner for ethereum, and

项目说明

Pakala
======

![PyPI]()
![Build States]()

<img align="right" src="

*"ilo Pakala li pakala e mani sona"*

* Pakala is a tool to search for exploitable bugs in Ethereum smart contracts.
* Pakala is a symbolic execution engine for the Ethereum Machine.

The intended public for the tool are security researchers interested by Ethereum / the EVM.

Installation
------------

It works only with python 3.

Usage
-----

Let's look at 0xeBE6c7a839A660a0F04BdF6816e2eA182F5d542C:
it has a `transfer(address _to, uint256 _value) function. It is supposedly protected by a require(call.value - _value) >= 0
but that condition always holds because we are substracting two unsigned integers, so the result is also an unsigned integer.

Let's scan it:

The contract balance being 0, we won't be able to have it send us some ethers.
So we o the balance to be 1 ETH: then it has some "" money to send us.

The tool with tell you a bug was found, and dump you a path of "states". Each
state corresponds to a transaction, with constraints that needs to be respected
for that code path to be taken, storage that has been read/written...

Advice: look at calldata[0] in the constraints to see the function signature for each transaction.

See pakala help` for more complete usage information.

How does it works? What does it do?
-----------------------------------

See the introductory article for more information and a demo.

In a nutshell:

* It's very good at finding simple bugs in simple contracts.
* The false-positive rate is very low. If it flags your contract it's likely people can drain it.
* It can exploit non-trivial bugs requiring to o some storage keys with others (array size underflow...), has a good
modeling of cryptographic hashes, and support chaining multiple transactions.

However, It only implements an "interesting" subset of the EVM. It doesn't handle:

* gas,
* precompiles,
* or a contract interacting with other contracts (DELEGATECALL, STATICCALL...).

This means that CALL support is limited to sending ethers. Other tools like Manticore can do that much better, and the focus for
Pakala was offensi scanning of contracts *en masse*.

项目信息

开发语言：Python

Star 数：344

技术要点

该项目属于安全软件方向的开源资源，代码结构清晰，适合安全研究人员学习参考。项目围绕Offensive vulnerability scanner for ethereum, and symbolic execution tool for the Ethereum Virtual Machine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。