GZ::CTF

GZ::CTF is an open source CTF platform based on ASP.NET Core, using Docker or K8s as the container deployment backend, providing customizable challenges types, dynamic containers and dynamic scores.

This project originated from the author's idea that the implementation of CTFd is not elegant enough, the dynamic container configuration needs to be implemented by plug-ins, and the front-end is not good-looking. At the same time, in order to hold school CTF and help students from other schools to run their CTF, I wrote one by myself.

GZ::CTF is open source under AGPLv3 license, use and modification are subject to the open source license. Please refer to Quick Start for deployment.

Features 🛠️

• Create highly customizable challenges

  • Type of challenges: Static Attachment, Dynamic Attachment, Static Container, Dynamic Container

    • Static Attachment: Shared attachments, any configured flag can be accepted.
    • Dynamic Attachment: The number of flags and attachments must be at least the number of teams. Attachments and flags are distributed according to the teams.
    • Static Container: Shared container templates, no dynamic flag is issued, and any configured flag can be submitted.
    • Dynamic Container: Automatically generate and issue flags through container environment variables, and flag of each team is unique.

  • Dynamic Scores

    • Curve of scores:

      $f(S, r, d, x) = \left \lfloor S \times \left[r + ( 1- r) \times \exp\left( \dfrac{1 - x}{d} \right) \right] \right \rfloor$

      Where $S$ is the original score, $r$ is the minimum score ratio, $d$ is the difficulty coefficient, and $x$ is the number of submissions. The first three parameters can be customized to satisfy most of the dynamic score requirements.

    • Bonus for first three solves: The platform rewards 5%, 3%, and 1% of the current score for the first three solves respectively.

  • Disable or enable challenges during the competition, and release new challenges at any time.

  • Dynamic flag sharing detection, optional flag template, leet flag

• Teams score timeline, scoreboard. Teams can be grouped

• Dynamic container distribution, management, and multiple port mapping methods based on Docker or K8s

• Real-time competition notification, competition events and flag submission monitoring, and log monitoring based on SignalR

• SMTP email verification, malicious registration protection based on Google ReCaptchav3

• Ban specific user, three-level user permission management

• Optional team review, invitation code, registration email restriction

• Writeup collection, review, and batch download in the platform

• Download exported scoreboard, export all submission records

• Monitor submissions and major event logs during the competition

• Challenges traffic forwarding based on TCP over WebSocket proxy, configurable traffic capture

• Cluster cache based on Redis, database storage backend based on PGSQL

• Data tracking and monitoring based on Prometheus / OpenTelemetry

• Customizable global configuration, platform title, record information

• And more...

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Demo 🗿