Add custom PAM module to attempt login with the osk-sdl password
See pmaports#823 (comment 433581347) for context.
TODO:
- let osk-sdl store the password that was typed in the kernel keyring
- create a custom PAM module that reads this password
- if the password typed into osk-sdl is NOT the autologin user's password: return, otherwise:
- set an env var to let tinydm-run-session know that this worked
- set this password as pass for the PAM session, so it will be used with gnome-keyring, kwallet etc.
- enable the module in
/etc/pam.d/autologin
- tinydm-run-session.sh: if the env var is set, and phosh will be started, set
GDMSESSION=phosh
to let phosh know that the PAM session is already set up and that the lockscreen and PAM session setup can be skipped.