foundry-ctf-template

This template is based on Zellic's example-ctf-challenge, which was updated by minaminao, and further enhanced to streamline the process of developing challenges using this template.

Getting Started

$ forge init --template bshyuunn/foundry-ctf-template my-solidity-challenge
$ cd my-solidity-challenge
$ make all

$ nc localhost 31337
1 - launch new instance
2 - kill instance
3 - get flag (if isSolved() is true)
action? 

Creating Your Own Challenge

First, place your custom challenge files in the src/ directory. The Setup.col file is essential, and you also need to implement the isSolved function to check if the challenge has been solved. Other environment setup tasks should be handled in the constructor.

Additionally, you can write a script to solve the challenge in the script/ directory, and you can add test code for your challenge in the test/ directory.

Next, to configure the environment for your challenge, modify the docker-compose.yml file. Change simple-challenge: to the name of your challenge and adjust other values in the file to fit your challenge's environment.

services:
  simple-challenge:
    build: ./build
    ports:
      - "31337:31337"
      - "8545:8545"
    restart: unless-stopped
    environment:
      - FLAG=CTF{FLAG}
      - PORT=31337
      - HTTP_PORT=8545
      - PUBLIC_IP=localhost
      - SHARED_SECRET=47066539167276956766098200939677720952863069100758808950316570929135279551683
      - SETUP_CONTRACT_VALUE=0
      - USER_VALUE=10000000000000
      - EVM_VERSION=cancun # `cancun`, `shanghai`, `paris`, `london`, etc...

1. FLAG
   The secret value participants need to find.

2. PORT
   The port for service communication (default: 31337).
   If changed, also update docker-compose.yml under ports: - "31337:31337".

3. HTTP_PORT
   The port for RPC communication with the Ethereum node (default: 8545).
   If changed, also update docker-compose.yml under ports: - "8545:8545".

4. PUBLIC_IP
   The public IP for hosting the service (set to localhost for local development).

5. SHARED_SECRET
   An authentication value used when creating a blockchain network internally. (this value should be set randomly)

6. SETUP_CONTRACT_VALUE
   The value sent to the Setup Contract (default: 0).

7. USER_VALUE
   The initial balance value for the CTF player.

8. EVM_VERSION
   The Ethereum version to use (cancun, shanghai, paris, etc.).

Additionally, when changing the EVM_VERSION, make sure to properly set the desired version in the foundry.toml file as well:

[profile.default]

evm_version = "cancun"  # Set to your desired version, such as `cancun`, `shanghai`, `paris`, `london`, etc.