Thread by @Netxing

Getting back to the "weekend project" sessions!

This weekend, I am working on the proxmark3 RDV4 again. Some time ago I programmed the reblay standalone feature to relay data over its HC-06 Bluetooth device in the Blue Shark add-on device: github.com/RfidResearchGr… 1/n

Knowing the limitations of HC-06 device, I decided to try something different for the communication. First, I had to find UART pins without breaking apart the Blue Shark. Removing the case in the back side, there are two pins without labels. That's our UART! 2/n

For testing purposes, I am using a small ESP32 from @adafruit adafruit.com/product/5405?g… with WiFi and BLE technology. The main purpose of the ESP32 is to see if I can relay data over WiFi with a MQTT 3/n

The ESP32 C3 is small and extremely easy to configure to be programmed with @arduino environment. Now the idea is to design a bridge between WiFi and UART data. 4/n

A cool feature from this ESP32 is the NeoPixel LED that it's really useful to show the process status. In this example, I used it for WiFi connectivity(red), MQTT connection(blue) and ready stage(solid green)

For MQTT server, I'll use Mosquitto broker: mosquitto.org

I designed two programs:
- An Arduino sketch that will play the role of bridging data between UART and MQTT by WiFi connectivity: github.com/salmg/proxmark…
- A python script that will obtain the MQTT data in the commands topic, and respond with static data: github.com/salmg/proxmark…

Running all together:
1. Reset the ESP32 and connected to WiFi and MQTT broker
2. Run the testMQTT script to be ready to respond with static data after it receives a command by MQTT
3. Run the reblay standalone in the emulation way
4. The phone mimicking a terminal to send a cmd

Issues:

It is difficult to establish a fast and adequate communication between UART and WiFi.

The standalone "reblay" from the official repository seems to crash by overflow data. I used the old version proxmark3 from my repository to be able to send and receive UART data

Overall, with this approach, we can conclude that it is possible to establish other ways to interact with the Proxmark3 UART for futuristic and interesting projects. Thanks for reading!

What was your weekend project!?

#weekendproject #proxmark3