Pwn2Win CTF 2018

About our NIZK (Non-Interactive Zero-Knowledge) Platform: https://arxiv.org/pdf/1708.05844.pdf

Registration

1. All team members must have a GitHub account and configure a SSH key in their account settings.

   Important Note: If you are unable to follow the installation instructions below, or is simply too lazy to do all the steps, we made a LXD container preloaded with this platform. If you prefer Docker, we made a Dockerfile too. If you want to install directly in your machine (instead of containers), just ignore this note.

2. All team members must clone the repository and install the dependencies:

   git clone git@github.com:pwn2winctf/2018.git
   cd 2018
   sudo apt-get install libsodium23
   curl https://bootstrap.pypa.io/get-pip.py | sudo -H python
   sudo -H python -m pip install -r pip-requirements.txt

   Note: Any libsodium version >= libsodium18 is supported. However, recent pysodium has a bug when used together with old libsodium. Therefore, if you use libsodium18, please change pip-requirements.txt second line to pysodium == 0.6.9.1 in order to use exactly the pysodium version which works correctly with libsodium18.

3. All team members must have the git client correctly set up. If you have never used git before, run:

   git config --global user.name "John Doe"
   git config --global user.email johndoe@example.com

4. If dependencies are installed correctly (or if you used one of our preloaded containers), you should now see the help menu when calling:

   ./ctf -h

5. The leader of the team must execute the following command and follow the instructions to register the team:

   ./ctf init

6. The other members of the team must login to GitHub without registering a new team, by running:

   ./ctf login

7. After that, the leader must share the team-secrets.json with the members of the team. The other members of the team must place the team-secrets.json file shared by the leader in their 2018 directory.

Challenges

Challenges are available on https://pwn2.win/2018.

If you prefer to browse them locally, you may also run a local webserver by typing ./ctf serve, or list challenges through the command line interface:

./ctf challs

Flag submission

To submit a flag:

./ctf submit --chall chall-id 'CTF-BR{flag123}'

You may omit --chall chall-id from the command, however it will be slower to run this way. In this case, we will look for the flag in every challenge released until now.

VPN

To get the VPN credentials after your team has unlocked it (by solving at least 6 challenges - see the rules page for more details):

./ctf news --pull

Scoreboard

You can see the scoreboard in the game link (https://pwn2.win/2018), locally (if you ran the local webserver) or through the command line interface:

./ctf score --names --pull

Support

You may reach us through #pwn2win at irc.freenode.net.