By skyforbes I’ve built a Linux-native software authenticator called passless, written in Rust. It fully emulates a FIDO2 / WebAuthn security key through a virtual UHID device, so it can work as a drop-in replacement for hardware tokens.
It supports passkeys (resident credentials) and offers two main storage backends: one integrated with pass, and another backed by TPM 2.0. It’s still a software authenticator, so it doesn’t provide the same security guarantees as a real hardware FIDO2 device, but the aim is to offer a practical, Linux-friendly option for everyday use and testing.
Repo: https://github.com/pando85/passless
Feedback is welcome, especially from people using FIDO2 or passkeys on Linux.