Update: Head to Cyfrin Updraft

ℹ️ Important: This repo is no longer maintained; we invite all people learning Solidity to head to Cyfrin Updraft! The 100% free #1 smart contract education platform on earth. Developed with love by Patrick & Cyfrin <3

Hardhat Security

This is a section of the Javascript Blockchain/Smart Contract FreeCodeCamp Course. This part of the course is to help users understand basic security and some fundamentals of auditing.

This repo has a few contracts with big flaws, see if you can see them, and see if the tools help you find them!

This repo has been updated for Sepolia over Goerli.

⌨️ (31:28:32) Lesson 18: Security & Auditing

Full Repo

• Hardhat Security
• What is an Audit?
• Help your auditors!
• Process
• Resources
  • Tools
  • Games
  • Blogs
  • Audit Examples:
  • Articles
• Getting Started
  • Requirements
  • Quickstart
  • No Typescript Support
    • Optional Gitpod
• Usage
  • Slither
  • Echidna
• Linting
• Formatting
• Thank you!

This project is apart of the Hardhat FreeCodeCamp video.

What is an Audit?

An audit is a security focused code review for looking for issues with your code.

Help your auditors!

When writing good code, you 100% need to follow these before sending you code to an audit.

Tweet from legendary security expert Tincho

• Add comments
  • This will help your auditors understand what you're doing.
• Use natspec
  • Document your functions. DOCUMENT YOUR FUNCTIONS.
• Test
  • If you don't have tests, and test coverage of all your functions and lines of code, you shouldn't go to audit. If your tests don't pass, don't go to audit.
• Be ready to talk to your auditors
  • The more communication, the better.
• Be prepared to give them plenty of time.
  • They literally pour themselves over your code.

"At this time, there are 0 good auditors that can get you an audit in under a week. If an auditor says they can do it in that time frame, they are either doing you a favor or they are shit. " - Patrick Collins, March 4th, 2022

Process

An auditors process looks like this:

1. Run tests
2. Read specs/docs
3. Run fast tools (like slither, linters, static analysis, etc)
4. Manual Analysis
5. Run slow tools (like echidna, manticore, symbolic execution, MythX)
6. Discuss (and repeat steps as needed)
7. Write report (Example report)

Typically, you organize reports in a chart that looks like this:

Resources

These are some of the best places to learn even MORE about security:

PRs welcome to improve the list.

Tools

• Slither
  • Static analysis from Trail of Bits.
• Echidna
  • Fuzzing from Trail of Bits.
• Manticore
  • Symbolic execution tool from Trail of Bits.
• MythX
  • Paid service for smart contract security.
• Mythrill
  • MythX free edition.
• ETH Security Toolbox
  • Script to create docker containers configured with Trail of Bits security tools.
• ethersplay
  • ETH Disassembler
• Consensys Security Tools
  • A list of Consensys tools.

Games

• Ethernaut (This is a must play!)
• Damn Vulnerable Defi (This is a must play!)

Blogs

• rekt
  • A blog that keeps up with all the "best" hacks in the industry.
• Trail of bits blog
  • Learn from one of the best auditors in the space.
• Openzeppelin Blog
  • Another blog of one of the best auditors in the space.

Audit Examples:

• Openzeppelin
• Sigma Prime
• Trail of Bits

Articles

• Smart Contract Security Best Practices
  • Consensys blog on security vulnerabilities. Also check out their tools.
• Chainlink X Certik Blog on Security
  • I helped write this. 😊
• More attacks

Getting Started

Requirements

• Git
  • You'll know you did it right if you can run git --version and you see a response like git version x.x.x
• Nodejs
  • You'll know you've installed nodejs right if you can run:
    • node --version and get an ouput like: vx.x.x
• Yarn instead of npm
  • You'll know you've installed yarn right if you can run:
    • yarn --version and get an output like: x.x.x
    • You might need to install it with npm
• Docker
  • You'll know you've installed docker right if you can run:
  • docker --version and get an ouput like Docker version xx.xx.xx, build xxxxx

Quickstart

git clone https://github.com/PatrickAlphaC/hardhat-security-fcc
cd hardhat-security-fcc
yarn set version 1.22.19   # can skip if your default version is already 1.x.x
yarn

(Yarn version 1 is recommended because auto-migration of this repo to yarn v2 doesn't go well. If your node version is incompatible with this, try node 16.19.1.) Then, go right into usage

No Typescript Support

Sorry! Feel free to make a PR if you'd like to see typescript here.

Optional Gitpod

If you can't or don't want to run and install locally, you can work with this repo in Gitpod. If you do this, you can skip the clone this repo part.

Usage

Slither

Open the docker shell:

yarn toolbox

Then, run:

slither /src/contracts/ --solc-remaps @openzeppelin=/src/node_modules/@openzeppelin --exclude naming-convention,external-function,low-level-calls

To exit:

exit

Echidna

Open the docker shell:

yarn toolbox

Then, run this:

echidna-test /src/contracts/test/fuzzing/VaultFuzzTest.sol --contract VaultFuzzTest --config /src/contracts/test/fuzzing/config.yaml

To exit:

exit

Linting

To check linting / code formatting:

yarn lint

or, to fix:

yarn lint:fix

Formatting

yarn format

Thank you!

If you appreciated this, feel free to follow me or donate!

ETH/Polygon/Avalanche/etc Address: 0x9680201d9c93d65a3603d2088d125e955c73BD65