Use PIN protection

[asdil12]

I'm not sure if this is applicable here, but it would be nice, if it would optionally be possible to protect the tpm by a PIN that is requested from the user via pinentry when authenticating.

[psanford]

Yup, I plan on adding that for user-verification as part of supporting fido2.

[497a]

I also would be happy about this feature! I like the idea of FDO but the idea of anyone just having to press 'OK' instead of having to provide a password bugs me a bit. I'd like to use passwordless login but no pin would mean unlimited access to my services for anyone with physical access to my device.

[PaarthShah]

Is there any particular set of things a potential contributor could look at to help support PINs?
Asking for a friend :^)

[guiand888]

Also looking forward to this feature! :)
Would be even nicer to integrate with PAM too as I assume we'd then be able to authenticate with a fingerprint reader.