This idea is interesting to me because hell making my own stuff is fun. I have access to quite a few usb keys already so technically I might have the material available. Also my threat model is pretty low so I’m interested in security mostly for fun.
Most methods I have found talk about making a key to secure a computer but I would really like to make something that would do WebAuthn.
There is a neat Git project that shows how to turn a few specific devices into 2FA code prompters/automatic fillers. But in my naive mind that falls short of what I would truly wish to be able to accomplish ie. Stock USB --> WebAuthn/Passkey device.
Has anybody seen anything on the subject?
You could try USB Raptor - it’s Windows only and works as a wrapper to use your drive as the authentication since you need special hardware to make an actual HID authentication device as @SpaceNoodle correctly stated.
https://sourceforge.net/projects/usbraptor/
There were a few different resources talking about ways to make a security key that locks/unlocks a computer. It’s not on my radar right now. Thank you for sharing this one.