For a long time, I’ve wanted to be able to use a flipper zero as an NFC to USB bridge for FIDO2 tokens (Apex), due to Apple’s lack of support for NFC and my phone being iOS.
With the help of Claude Fable, I’ve managed to get to a working implementation for Momentum Firmware, tested with Yubico’s test page on a Mac. This works with both the latest Vivokey Apex applet and a YubiKey 5C. This also was heavily inspired by BryanJacob’s FIDO2 bridge, and StarGate01’s setup with a Pi acting as a HID device.
This does work best with one of the magic stickers from @Hamspiced on the Flipper.
Hopefully this ends up being useful to someone other than me.