Introduction

Learn how to enable a fingerprint reader (Fingerprint) on your laptop with KDE on Linux. In this article, the login manager assumes SDDM. Also, the setting method may differ depending on the distribution.

Fingerprint authentication setting at login (SDDM)

Add ʻauth sufficient pam_fprint.so to the top of /etc/pam.d/sddm`.

#%PAM-1.0

auth		sufficient	pam_fprintd.so
auth		include		system-login
-auth   	include		pam_kwallet5.so
-auth		optional	pam_gnome_keyring.so

account		include		system-login

password	include		system-login
-password	optional	pam_gnome_keyring.so use_authtok

session		optional	pam_keyinit.so force revoke
session		include		system-login
-session  	optional	pam_kwallet5.so auto_start
-session	optional	pam_gnome_keyring.so auto_start

After setting, fingerprint authentication will be enabled by pressing enter once when the password entry field is empty.

Fingerprint authentication setting on lock screen

Lock screens such as after sleep are authenticated by KDE, not SDDM. Add ʻauth sufficient pam_unix.so try_first_pass likeauth nullok and ʻauth sufficient pam_fprint.so to the top of /etc/pam.d/kde.

#%PAM-1.0

auth 			sufficient  	pam_unix.so try_first_pass likeauth nullok
auth            sufficient      pam_fprintd.so
auth            include         system-login

account         include         system-login

password        include         system-login

session         include         system-login

After setting, you can unlock by fingerprint authentication after pressing enter once with the password input field empty as with SDDM.

Bonus (troubleshooting when you cannot return to sleep)

By default, you may not be able to wake up from the sleep state. Here's a solution if you're using GRUB as your bootloader.

First, open / etc / default / grub. I think there are some differences, but I think the content is as follows. Rewrite GRUB_CMDLINE_LINUX =" " at the bottom to GRUB_CMDLINE_LINUX =" nouveau.modeset = 0 ".

# GRUB boot loader configuration

GRUB_DEFAULT=0
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="Arch"
GRUB_CMDLINE_LINUX_DEFAULT="loglevel=3 quiet"
GRUB_CMDLINE_LINUX=""

After rewriting, execute sudo grub-mkconfig -o /boot/grub/grub.cfg to reflect the previous setting change. Once you reboot, you will be able to wake up from sleep.

Fingerprint authentication settings with sudo

Add ʻauth sufficient pam_fprintd.so to the top of /etc/pam.d/sudo`.

#%PAM-1.0
auth		sufficient	pam_fprintd.so
auth		include		system-auth
account		include		system-auth
session		include		system-auth

in conclusion

I introduced how to enable fingerprint authentication on login screen, lock screen, and sudo.

[LINUX] How to use fingerprint authentication for KDE