Fingerprint login issue

[tobyrg]

When logging in using a fingerprint, there is currently a confirm button that needs to be pressed after the fingerprint has been read. Ideally, I would prefer to log in directly without having to press the confirm button once the fingerprint is read.

[ChocolateLoverRaj]

I don't see anything in the code that will unlock with a fingerprint. As far as I know it only uses login PAM. I think you may be using a hack that allows the login PAM to also accept fingerprint. Did you make any modifications to your PAM?

[tobyrg]

From my understanding cosmic-greeter uses PAM, I enabled Fingerprint authentication PAM profile.

The issue I'm having is that when logging in for the first time you must press confirm, I'm unsure how I could take a screenshot of this.

[ChocolateLoverRaj]

I enabled Fingerprint authentication PAM profile

What distro are you using and what is the contents of your /etc/pam.d/login?

cosmic-greeter uses PAM

PAM was not made to support either password or fingerprint in a single PAM module. You can use PAM to unlock with either fingerprint or password, but using two PAMs at the same time, not one PAM.

Does your fingerprint login work as expected for other DEs? Are you using https://gitlab.com/mishakmak/pam-fprint-grosshack?

[tobyrg]

Fingerprint works fine when I used GNOME, I just ran sudo pam-auth-update and added Fingerprint authentication.

[tobyrg]

I am using Pop_OS! 22.04

This is my /etc/pam.d/login

#
# The PAM configuration file for the Shadow `login' service
#

# Enforce a minimal delay in case of failure (in microseconds).
# (Replaces the `FAIL_DELAY' setting from login.defs)
# Note that other modules may require another minimal delay. (for example,
# to disable any delay, you should add the nodelay option to pam_unix)
auth       optional   pam_faildelay.so  delay=3000000

# Outputs an issue file prior to each login prompt (Replaces the
# ISSUE_FILE option from login.defs). Uncomment for use
# auth       required   pam_issue.so issue=/etc/issue

# Disallows other than root logins when /etc/nologin exists
# (Replaces the `NOLOGINS_FILE' option from login.defs)
auth       requisite  pam_nologin.so

# SELinux needs to be the first session rule. This ensures that any
# lingering context has been cleared. Without this it is possible
# that a module could execute code in the wrong domain.
# When the module is present, "required" would be sufficient (When SELinux
# is disabled, this returns success.)
session [success=ok ignore=ignore module_unknown=ignore default=bad] pam_selinux.so close

# Sets the loginuid process attribute
session    required     pam_loginuid.so

# Prints the message of the day upon successful login.
# (Replaces the `MOTD_FILE' option in login.defs)
# This includes a dynamically generated part from /run/motd.dynamic
# and a static (admin-editable) part from /etc/motd.
session    optional   pam_motd.so motd=/run/motd.dynamic
session    optional   pam_motd.so noupdate

# SELinux needs to intervene at login time to ensure that the process
# starts in the proper default security context. Only sessions which are
# intended to run in the user's context should be run after this.
# pam_selinux.so changes the SELinux context of the used TTY and configures
# SELinux in order to transition to the user context with the next execve()
# call.
session [success=ok ignore=ignore module_unknown=ignore default=bad] pam_selinux.so open
# When the module is present, "required" would be sufficient (When SELinux
# is disabled, this returns success.)

# This module parses environment configuration file(s)
# and also allows you to use an extended config
# file /etc/security/pam_env.conf.
# 
# parsing /etc/environment needs "readenv=1"
session       required   pam_env.so readenv=1
# locale variables are also kept into /etc/default/locale in etch
# reading this file *in addition to /etc/environment* does not hurt
session       required   pam_env.so readenv=1 envfile=/etc/default/locale

# Standard Un*x authentication.
@include common-auth

# This allows certain extra groups to be granted to a user
# based on things like time of day, tty, service, and user.
# Please edit /etc/security/group.conf to fit your needs
# (Replaces the `CONSOLE_GROUPS' option in login.defs)
auth       optional   pam_group.so

# Uncomment and edit /etc/security/time.conf if you need to set
# time restraint on logins.
# (Replaces the `PORTTIME_CHECKS_ENAB' option from login.defs
# as well as /etc/porttime)
# account    requisite  pam_time.so

# Uncomment and edit /etc/security/access.conf if you need to
# set access limits.
# (Replaces /etc/login.access file)
# account  required       pam_access.so

# Sets up user limits according to /etc/security/limits.conf
# (Replaces the use of /etc/limits in old login)
session    required   pam_limits.so

# Prints the last login info upon successful login
# (Replaces the `LASTLOG_ENAB' option from login.defs)
session    optional   pam_lastlog.so

# Prints the status of the user's mailbox upon successful login
# (Replaces the `MAIL_CHECK_ENAB' option from login.defs). 
#
# This also defines the MAIL environment variable
# However, userdel also needs MAIL_DIR and MAIL_FILE variables
# in /etc/login.defs to make sure that removing a user 
# also removes the user's mail spool file.
# See comments in /etc/login.defs
session    optional   pam_mail.so standard

# Create a new session keyring.
session    optional   pam_keyinit.so force revoke

# Standard Un*x account and session
@include common-account
@include common-session
@include common-password

[ChocolateLoverRaj]

That's weird, your /etc/pam.d/login file doesn't mension fprintd anywhere. Is it part of one of the @included files? I'm pretty sure GNOME uses /etc/pam.d/gdm-fingerprint for fingerprint login, which cosmic-greeter doesn't use, so I'm wondering how cosmic-greeter even unlocks with a fingerprint for you.

https://manpages.ubuntu.com/manpages/trusty/man8/pam-auth-update.8.html says it changes /etc/pam.d/common-*. Is the fingerprint login configured in one of those files? Also what is the behavior of pamtester login $USER authenticate?

[zeroZshadow]

The standard method I've been using is installing fprintd followed by libpam-fprintd, then run pam-auth-update as @tobyrg mentions. This lets you select the fingerprint as an option. I've used this method to make it work on gnome as well as plasma.

[tobyrg]

Here is the photo of the issue, as you can see there is a Confirm button that has to be pressed once the fingerprint has been read.

[jotuel]

The way I understand this it is not a fingerprint login issue but more of an improvement idea that placing a finger on the scanner should produce following behavior:

1. Fingerprint gets scanned
2. Scan is compared to all users all registered fingerprint
3. If match is found the system logs you in as the user that the matched fingerprint was registered to.
4. No match found should display some error, or prompt, to let the user know it failed.

e. This from fprintd "Known issues:

• pam_fprintd does not support identifying the user itself as that would mean having the fingerprint reader on for all the time the user selection is displayed, and could damage the hardware. It could be fixed by having gdm/login only start the PAM conversation when there is activity
• pam_fprintd doesn't support entering either the password or a fingerprint, as pam_thinkfinger does, because it's a gross hack, and could be fixed by having the login managers run 2 separate PAM stacks"

Also the installer should offer the option when finding a known working scanner hardware to set up fprintd, libpam-fprintd, pam-auth-update && fprintd-enroll, preferably in a GUI.