The last update on my FIDO2 project was more than a year ago. I was quite busy with work and other problems. However, the project did not stop.

Unfortunately, Google did not return the BLE authenticator to the Chrome browser and does not seem to do that in the future. So, our options for usable authenticators are either USB or NFC. The ESP32 microcontroller does not have a USB and I tried to come up with the software implementation. I did not have much progress there and decided to switch to other MCUs.

At the time I’m experimenting with STM32 one and expecting the development board with RP2040 to arrive soon. The main drawback of STM32 is that they are bought out practically everywhere. Luckily, I still have a few of them from the times when I wanted to replicate the famous Solo Key. A bunch of leftover chips for voltage regulation and security from the previous project were used.

FIDO2 USB dongle with fingerprint scanner

I’ve traced a simple PCB for it and now I’m busy with the implementation of USB transport.

The overall design is practically the same as before - the FPC1020 fingerprint scanner and ATECC608a Secure Element.