SDCTF 2021

Here is the challenge and infrastructure files of San Diego CTF 2021. Challenge files include source code that implement the challenge ideas.

This CTF was deployed on Google Cloud Platform using the brilliant kCTF framework. Please check them out.

This CTF used the novel Discord-based ctfbot as its frontend.

Disclaimer

San Diego CTF is managed by the ACM chapter at UC San Diego's Cyber community. We're a bunch of college students and SDCTF 2021 is over, so no support will be provided for the building, deploying, and managing of these challenges. This repository is published as a courtesy in the hopes that it will be educational to those interested in cybersecurity.

Contents

Each challenge is in its own subdirectory with its build files (Ex. Makefiles), generation scripts, and deploy files (Ex. Dockerfiles, challenge.yaml). README.md inside those folders are summaries of the challenge, information about CTF performance, internal specifications (if available), and links to writeups (if provided).

Build and Deploy Instructions

First time setup for deployment: do the following in the given order

1. Setup kctf environment (lol don't underestimate this)
2. Run command ./build-all.sh. This is necessary to generate both attachments and deployment files.
3. Run command kctf chal start in every directory containing challenge.yaml (Tip: List them using find . -name challenge.yaml) You can also currently run challenges locally (without deploying to a running cluster) with kctf chal debug docker. See the official docs for more information.

After updating the source code of any challenge(s), remember to run ./build-all.sh again (or the relevant Makefiles) so the attachment and/or deployment files can be updated. Then, run kctf chal start on the updated challenges to update the deployment.

We recommend building/running everything in Google Cloud Shell, which has a lot of tools (Ex. gcc) already built in. However, there are some additional tools that you need to install as some Makefiles depends on them:

• Onelinerizer: pip2 install onelinerizer
• Nasm: sudo apt-get install nasm
  • If you are using Google Cloud Shell, use ~/.customize_environment. See the section below

Google Cloud Shell

It is recommended to add the following to ~/.customize_environment in Google Cloud Shell so you have all the packages necessary to build or test the CTF.

#! /bin/bash
# Netcat/socat is useful when testing broken challenges. It is not necessary for building challenges
# Nasm is necessary to build some pwn challenges written in assembly
apt-get update -y && apt-get -y install netcat-openbsd socat nasm