CTF Challenge Maker & Writeup Submission Guide

Format flag: INTECHFEST{.*} Maximum flag length: 64

Important Dates

• CTF Start Date: 6 September 2025
• Challenge Submission Deadline: 8 September 2025

Instructions for Participants

If you successfully solve a challenge, please consider contributing a detailed writeup to help the community learn. When submitting your writeup, follow these guidelines:

• Fork & Branch: Fork the repository and create a new branch for your writeup submission.
• Directory Structure: Place your writeup in the appropriate challenge folder (e.g., Web/<challenge_name>/writeups/<yourname>/, Crypto/<challenge_name>/writeups/<yourname>/, etc.).
• Content: Ensure your writeup includes:
  • A brief overview of the challenge.
  • Steps of your approach, including any commands, code snippets, or screenshots.
• Submission: Open a Pull Request once your writeup is ready.

Instructions for Challenge Authors

As a challenge author, it is highly recommended to include a solver to assist participants in verifying their solutions and understanding the intended approach. Please follow these guidelines:

• Use Template Structure: Base your challenge on the templates provided in the .example/ directory:

  • static-attachment/ - For challenges with static files/attachments
  • static-attachment-with-compose/ - For challenges requiring Docker Compose setup
  • static-attachment-with-compose-traefik/ - For challenges requiring custom domain routing, host SNI, or Traefik reverse proxy integration
  • static-container/ - For challenges that need one container per person/team
  • dynamic-container/ - For challenges that need dynamic container per person/team

• ⚠️ Hints in challenge.yml: You can add hints in your challenge.yml file if desired, but keep in mind that these hints will automatically become public on the platform once the challenge is published and will be visible to all participants.

Automatic Challenge Updates

The CTF CI/CD supports automatic challenge updates when you push changes to the repository. Here's how it works:

Update Types Based on File Location:

• 📝 Configuration Changes (challenge.yml): Updates challenge metadata, description, flags, and attachments
• 📁 Attachment Updates (dist/ folder): Updates only the challenge attachment files
• 🔄 Full Redeploy (src/ folder): Stops services, updates challenge, and restarts services
• 🐳 Infrastructure Changes (Dockerfile, docker-compose.yml, Makefile): Complete redeploy with service restart
• 📚 Documentation (solver/, writeup/ folders): No updates (documentation only)

How to Update Your Challenge:

1. Make your changes to the appropriate files in your challenge directory
2. Commit and push your changes to the repository:

   git add .
   git commit -m "Update challenge: description and fix vulnerability"
   git push origin main

3. Automatic deployment happens within seconds based on what you changed:
   • Edit challenge.yml → Metadata update (~3 seconds)
   • Update dist/files.zip → Attachment update (~2 seconds)
   • Modify src/app.py → Full redeploy (~10 seconds)