GreyCTF Blockchain Infrastructure

Forked from https://github.com/uclaacm/lactf-archive/tree/main/2023/pwn/eth-challenge-base

Makes use of anvil from the foundry toolchain to create blockchain nodes.

Configuration Reference

The docker image is configurable with the use of environment variables.

Here is the list of configuration available for the docker image

Name	Default	Description
FLAG	grey{TEST_FLAG}	Challenge flag to be given on solving the challenge
PUBLIC_IP	127.0.0.1	Public IP/Hostname to display in RPC_URL
PORT	5000	Port number to bind to (for the challenge deployer service)
HTTP_PORT	8545	Port number to bind to (to host the web3 interface)
PER_SOURCE	1	Maximum concurrent connections for each IP
CPS_RATE	200	Maximum connections per second
CPS_DELAY	5	Service timeout when CPS_RATE has been hit
RLIMIT_CPU	5	Maximum number of CPU seconds that the service may use
CONTRACT_DEPLOY_ARGS	""	Arguments that will be used in deploying the Setup contract
CONTRACT_DEPLOY_VALUE	0	Amount of Ether to deploy the Setup contract with
PLAYER_VALUE	10	Amount of Ether to grant to the player
ETH_RPC_URL	https://eth-pokt.nodies.app	Ethereum chain that will be forked
RPC_KILL_TIMEOUT	600	Amount of seconds until Anvil node is terminated

Setting up the Image

docker build ./eth_container -t grey.ctf/evm-infra

Challenge Deployment

Using the built docker image, we can easily deploy on-demand blockchain challenges, with just the smart contract code.

FROM grey.ctf/evm-infra

# configuration
ENV FLAG="grey{i_am_the_flag!}"

# contracts
COPY contracts/ /tmp/contracts/

# additional configuration to build contract 
# uncomment if necessary
#
# COPY ./foundry.toml /tmp/foundry.toml
# COPY ./remappings.txt /tmp/remappings.txt

The contracts/ folder MUST contain a file Setup.sol, with a solidity contract called "Setup" that has the isSolved() function.

This contract will be deployed on creation of the ethereum node, and will be responsible for:

• Deploying any additional challenge contracts
• Checking if the challenge has been solved by returning a bool on the isSolved() function

TODO

• get the image build to work
• add a config to ask for a redpwn proof of work (prevent DoS but idk if necessary)
• make EVM node timeout configurable (default now is 1 hour)
• make SOLC version configurable
• update requirements.txt
• add github workflows to deploy docker image
• add github workflows to test that docker image works