What is NexMon?
NexMon is a firmware patching framework initially built for the BCM4339 WiFi firmware of Nexus 5 smartphones. However, this repository contains firmware patches for the BCM43438 WiFi chip used in the Raspberry Pi 3. It's main intention was to enable monitor mode and frame injection, which now works quite well. Nevertheless, we have also published many example patches that allow you to dive into firmware reverse engineering and firmware patching. The ability to write firmware patches in C makes it easy to use, especially for beginners.
News
- We moved to GitHub!
WARNING
Our software may damage your hardware and may void your hardware’s warranty! You use our tools at your own risk and responsibility! If you don't like these terms, don't use nexmon!
What this Repo contains
- A bootable image (Raspbian 8) for the micro SD card (8GB) of your Raspberry Pi 3, including a patched version of airgrack-ng:
- Everything needed to build the patches by yourself
Steps needed to run the prepared SD card image on your Raspberry Pi 3
- Login as
root
with the passwordnexmon
Monitor Mode
insmod /root/brcmfmac.ko
- thats it, try using tcpdump:
tcpdump -i wlan0 -s0
- or airodump-ng:
airodump-ng wlan0
Original firmware and driver
- Optional: remove the monitor mode driver
rmmod brcmfmac
cp /root/brcmfmac43430-sdio.orig.bin /lib/firmware/brcm/brcmfmac43430-sdio.bin
- use
modprobe brcmfmac
to load the unmodified driver and firmware
Steps to create your own firmware patches
source setup_env.sh
- for the monitor mode patch:
cd firmware_patching/monitor_mode/
make
- copy the
brcmfmac/brcmfmac.ko
to the/root/
directory of your Raspberry Pi - copy the
brcmfmac43430-sdio.bin
to/lib/firmware/brcm/
directory of your Raspberry Pi
Caveats
Switching channels does not workit works now, but it needs a patch in the kernel, see 8f4b7501dedf72306c471e4962478b8ffe91d7a8
Read our papers
Feel free to read and reference our papers on the development of this project
- M. Schulz, D. Wegemer and M. Hollick. [NexMon: A Cookbook for Firmware Modifications on Smartphones to Enable Monitor Mode] (http://arxiv.org/abs/1601.07077), CoRR, vol. abs/1601.07077, December 2015. bibtex
- M. Schulz, D. Wegemer, M. Hollick. DEMO: Using NexMon, the C-based WiFi firmware modification framework, Proceedings of the 9th ACM Conference on Security and Privacy in Wireless and Mobile Networks, WiSec 2016, July 2016.