[Fi]*regex 🔥
What is Firegex?
Firegex is a firewall that includes different functionalities, created for CTF Attack-Defence competitions that has the aim to limit or totally deny malicious traffic through the use of different kind of filters.
Get started firegex
What you need is a linux machine and docker ( + docker-compose )
python3 start.py
This command will generate the docker-compose configuration and start it with docker-compose, read the help with -h to customize you firegex instance.
We recommend to use -t paramether and specify the number of threads to use for each service running on firegex, this will make you network more stable with multiple connections python3 start.py -t 4.
The default port of firegex is 4444. At the startup you will choose a password, that is essential for your security.
Functionalities
- Regex filtering using NFQUEUE with nftables with a c++ file that handle the regexes and the requests, blocking the malicius requests. PCRE2 regexes are used. The requests are intercepted kernel side, so this filter works immediatly (IPv4/6 and TCP/UDP supported)
- TCP Proxy regex filter, create a proxy tunnel from the service internal port to a public port published by the proxy. Internally the c++ proxy filter the request with PCRE2 regexes. For mantaining the same public port you will need to open only in localhost the real service. (Only TCP IPv4)
- Port Hijacking (not available yet) allow you to redirect the traffic on a specific port to another port. Thanks to this you can start your own proxy, connecting to the real service using loopback interface. Firegex will be resposable about the routing of the packets using internally nftables
Documentation
Find the documentation of the backend and of the frontend in the related README files
Main Points of Firegex
1. Efficiency
Firegex should not slow down the traffic on the network. For this the core of the main functionalities of firegex is a c++ binary file.
2. Availability
Firegex must not become a problem for the SLA points! This means that firegex is projected to avoid any possibility to have the service down. We know that passing all the traffic through firegex, means also that if it fails, all services go down. It's for this that firegex implements different logics to avoid this. Also, if you add a wrong filter to your services, firegex will always offer you a fast or instant way to reset it to the previous state.
Why "Firegex"?
Initiially the project was based only on regex filters, and also now the main function uses regexes, but firegex have and will have also other filtering tools.
Credits
- Copyright (c) 2007 Arash Partow (http://www.partow.net) for the base of our proxy implementation
- Copyright (c) 2022 Pwnzer0tt1
TODO:
Next points
- Create hijacking port to proxy
- Explanation about tools in the dedicated pages making them more user-friendly
- Give the permission to set a startup password in start.py protecting firegex also at the first run
- buffering the TCP and(/or) the UDP stream to avoid to bypass the proxy dividing the information in more packets
- Adding new section with "general firewall rules" to manage "simple" TCP traffic rules graphically and through nftables