"pam_fprint is a simple PAM module which uses libfprint's fingerprint processing and verification functionality for authentication. In other words, instead of seeing a password prompt, you're asked to scan your fingerprint."
The idea is to use the built-in fingerprint reader in some notebooks for login using PAM. I will also explain how to use regular password for backup login method (solely fingerprint scanner is not recommended due to numerous reasons).
First, make sure you have one of the supported finger scanners. http://www.thinkwiki.org/wiki/Integrated_Fingerprint_Reader gives a list of supported devices. To check which one you have, type
You need to install pam and libfprint. In my case PAM was already installed.
# pacman -S pam libfprint
Once you made sure your reader is supported, you are good to go
# pacman -S pam_fprint
This is the tricky part. By defaut, only root has access to the device. You can create a signature from sudo, but then you can only use it for root user. After digging at the Ubuntu forums I found out the following solution which worked for me.
1. If the group plugdev doesn't exist (didn't for me), create it
2. Add yourself to the group
# gpasswd -a USER plugdev
3. Allow USB access
# chgrp -R plugdev /dev/bus/usb/
== Login configuration
Modify the auth section of /etc/pam.d/login to this
auth required pam_env.so auth sufficient pam_fprint.so auth sufficient pam_unix.so try_first_pass likeauth nullok auth required pam_deny.so