[SOLVED] Howdy face recognition

Ferdinand · 2021-09-06 16:47:05

I'm trying get Howdy to work.

According to the wiki it's a matter of installing the howdy package from AUR, and then adding PAM configurations for the processes where face recognition-based authentication is wanted.

Preconception:
If I understand PAM right, you only need to configure "end services", not included services. So, if I edit /etc/pam.d/lightdm I don't need to modify any included configurations, like /etc/pam.d/system-login or /etc/pam.d/system-auth. And things outside the "include path", like /etc/pam.d/system-local-login, aren't involved and won't need any howdy-related configuration either.

Problem:
I get howdy seemingly working, but it won't let me in :-)

What I tried:
I installed and configured Howdy as per the wiki:

$ lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 008: ID 05c8:0383 Cheng Uei Precision Industry Co., Ltd (Foxlink) HP HD Camera
Bus 001 Device 006: ID 138a:003f Validity Sensors, Inc. VFS495 Fingerprint Reader
Bus 001 Device 004: ID 8087:0a2b Intel Corp. Bluetooth wireless interface
Bus 001 Device 007: ID 0781:b6ba SanDisk Corp. CF SDDR-289
Bus 001 Device 005: ID 046d:0809 Logitech, Inc. Webcam Pro 9000
Bus 001 Device 003: ID 03f0:2f24 HP, Inc LP2475w Monitor Hub
Bus 001 Device 002: ID 046d:c52b Logitech, Inc. Unifying Receiver
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

$ v4l2-ctl --list-devices
UVC Camera (046d:0809) (usb-0000:00:14.0-2.2):
	/dev/video0
	/dev/video1

HP HD Camera: HP HD Camera (usb-0000:00:14.0-9):
	/dev/video2
	/dev/video3

Two cameras, so I use the Video 4 Linux path name:

$ ls -l /dev/v4l/by-id
total 0
lrwxrwxrwx 1 root root 12 06.09.2021 10:30 usb-046d_0809_0BEC0D5A-video-index0 -> ../../video0
lrwxrwxrwx 1 root root 12 06.09.2021 10:30 usb-046d_0809_0BEC0D5A-video-index1 -> ../../video1
lrwxrwxrwx 1 root root 12 06.09.2021 10:30 usb-Sonix_Technology_Co.__Ltd._HP_HD_Camera-video-index0 -> ../../video2
lrwxrwxrwx 1 root root 12 06.09.2021 10:30 usb-Sonix_Technology_Co.__Ltd._HP_HD_Camera-video-index1 -> ../../video3

Here's my full Howdy config.ini (I typed in the width and height from v4l2-ctl --list-devices --all just to be sure it's right:

$ ls -lad /lib/security/howdy
drw------- 9 root root 4,0K 06.09.2021 10:17 /lib/security/howdy/
$ sudo cat /lib/security/howdy/config.ini
# Howdy config file
# Press CTRL + X to save in the nano editor

[core]
# Print that face detection is being attempted
detection_notice = false

# Do not print anything when a face verification succeeds
no_confirmation = false

# When a user without a known face model tries to use this script, don't
# show an error but fail silently
suppress_unknown = false

# Disable Howdy in remote shells
ignore_ssh = true

# Disable Howdy if lid is closed
ignore_closed_lid = true

# Disable howdy in the PAM
# The howdy command will still function
disabled = false

# Use CNN instead of HOG
# CNN model is much more accurate than the HOG based model, but takes much more
# computational power to run, and is meant to be executed on a GPU to attain reasonable speed.
use_cnn = false

[video]
# The certainty of the detected face belonging to the user of the account
# On a scale from 1 to 10, values above 5 are not recommended
# Lower is better
certainty = 3.5

# The number of seconds to search before timing out
timeout = 4

# The path of the device to capture frames from
# Should be set automatically by an installer if your distro has one
# device_path = none
device_path = /dev/v4l/by-id/usb-Sonix_Technology_Co.__Ltd._HP_HD_Camera-video-index0

# Scale down the video feed to this maximum height
# Speeds up face recognition but can make it less precise
max_height = 320

# Set the camera input profile to this width and height
# The largest profile will be used if set to -1
# Automatically ignored if not a valid profile
# frame_width = -1
# frame_height = -1
frame_width = 640
frame_height = 480

# Because of flashing IR emitters, some frames can be completely unlit
# Skip the frame if the lowest 1/8 of the histogram is above this percentage
# of the total
# The lower this setting is, the more dark frames are ignored
dark_threshold = 50

# The recorder to use. Can be either opencv (default), ffmpeg or pyv4l2.
# Switching from the default opencv to ffmpeg can help with grayscale issues.
recording_plugin = opencv

# Video format used by ffmpeg. Options include vfwcap or v4l2.
# FFMPEG only.
device_format = v4l2

# Force the use of Motion JPEG when decoding frames, fixes issues with YUYV
# raw frame decoding.
# OPENCV only.
force_mjpeg = false

# Specify exposure value explicitly. This disables autoexposure.
# Use qv4l2 to determine an appropriate value.
# OPENCV only.
exposure = -1

[snapshots]
# Capture snapshots of failed login attempts and save them to disk with metadata
# Snapshots are saved to the "snapshots" folder
capture_failed = true

# Do the same as the option above but for successful attempts
capture_successful = true

[debug]
# Show a short but detailed diagnostic report in console
# Enabling this can cause some UI apps to fail, only enable it to debug
end_report = false

The IR camera test gives me 10 files, all containing colour pictures of me, in varying degrees of exposure (looks like exposure bracketing).

$ gst-launch-1.0 v4l2src device=/dev/v4l/by-id/usb-Sonix_Technology_Co.__Ltd._HP_HD_Camera-video-index0 num-buffers=10 ! image/jpeg ! multifilesink location="frame-%02d.jpg"
Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Pipeline is PREROLLED ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
Got EOS from element "pipeline0".
Execution ended after 0:00:00.587834090
Setting pipeline to NULL ...
Freeing pipeline ...

The howdy test shows a window, containing myself in glorious black and white, with my mug framed by a red circle - the circle follows as I move and, disregarding my mug, it looks quite good :-)
The GStreamer warnings can be ignored, according to the Wiki.

$ sudo howdy test
[ WARN:0] global /build/opencv/src/opencv-4.5.3/modules/videoio/src/cap_gstreamer.cpp (2056) handleMessage OpenCV | GStreamer warning: Embedded video playback halted; module source reported: Could not read from resource.
[ WARN:0] global /build/opencv/src/opencv-4.5.3/modules/videoio/src/cap_gstreamer.cpp (1034) open OpenCV | GStreamer warning: unable to start pipeline
[ WARN:0] global /build/opencv/src/opencv-4.5.3/modules/videoio/src/cap_gstreamer.cpp (597) isPipelinePlaying OpenCV | GStreamer warning: GStreamer: pipeline have not been created

Opening a window with a test feed

Press ctrl+C in this terminal to quit
Click on the image to enable or disable slow mode

QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
^C
Closing window

I have configured only the lightdm PAM configuration (password first, so I enter a blank password to go to the face authentication):

$ cat /etc/pam.d/lightdm
#%PAM-1.0
auth        sufficient  pam_unix.so try_first_pass likeauth nullok
auth        sufficient  pam_python.so /lib/security/howdy/pam.py
auth        include     system-login
-auth       optional    pam_gnome_keyring.so
account     include     system-login
password    include     system-login
session     include     system-login
-session    optional    pam_gnome_keyring.so auto_start

I'm fairly sure I have the correct camera with IR sensor. and howdy test seems to work.
If I press enter on the lightdm password the camera indicator lights up, but it just won't have it - I get a login error and I need to use my password to log in.

Edit: The login error is more or less "Wrong password entered, please try again"

I have the same problem with fprint by the way, so my assumption is that I'm doing something wrong on the PAM side of things?

Last edited by Ferdinand (2021-09-07 07:15:28)

loqs · 2021-09-06 16:56:00

What is in the journal for a failed lightdm login?
If you replace

auth        sufficient  pam_python.so /lib/security/howdy/pam.py

with

auth        sufficient  pam_permit.so

Can you then login after pressing enter? Confirming the issue is with that line.

Ferdinand · 2021-09-06 17:28:15

I think this is the relevant bit (I can of course post all if you want):

Sep 06 19:01:57 COMPUTERNAME lightdm[689]: pam_unix(lightdm:auth): authentication failure; logname= uid=0 euid=0 tty=:0 ruser= rhost=  user=USERNAME
Sep 06 19:01:57 COMPUTERNAME kernel: logitech-hidpp-device 0003:046D:4076.0005: HID++ 4.1 device connected.
Sep 06 19:01:57 COMPUTERNAME [689]: Attempting facial authentication for user USERNAME
Sep 06 19:01:58 COMPUTERNAME upowerd[387]: treating change event as add on /sys/devices/pci0000:00/0000:00:14.0/usb1/1-1/1-1:1.2/0003:046D:C52B.0003/0003:046D:4076.0005/power_supply/hidpp_battery_1
Sep 06 19:01:59 COMPUTERNAME kernel: usb 1-2.2: reset high-speed USB device number 5 using xhci_hcd
Sep 06 19:01:59 COMPUTERNAME lightdm[690]: [ WARN:0] global /build/opencv/src/opencv-4.5.3/modules/videoio/src/cap_gstreamer.cpp (2056) handleMessage OpenCV | GStreamer warning: Embedded video playback halted; module source reported: Could not read from resource.
Sep 06 19:01:59 COMPUTERNAME lightdm[690]: [ WARN:0] global /build/opencv/src/opencv-4.5.3/modules/videoio/src/cap_gstreamer.cpp (1034) open OpenCV | GStreamer warning: unable to start pipeline
Sep 06 19:01:59 COMPUTERNAME lightdm[690]: [ WARN:0] global /build/opencv/src/opencv-4.5.3/modules/videoio/src/cap_gstreamer.cpp (597) isPipelinePlaying OpenCV | GStreamer warning: GStreamer: pipeline have not been created
Sep 06 19:02:02 COMPUTERNAME systemd[1]: NetworkManager-dispatcher.service: Deactivated successfully.
Sep 06 19:02:02 COMPUTERNAME audit[1]: SERVICE_STOP pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=NetworkManager-dispatcher comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
Sep 06 19:02:02 COMPUTERNAME kernel: audit: type=1131 audit(1630947722.892:94): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=NetworkManager-dispatcher comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
Sep 06 19:02:05 COMPUTERNAME [689]: Failure, timeout reached
Sep 06 19:02:05 COMPUTERNAME dbus-daemon[381]: [system] Activating via systemd: service name='org.freedesktop.home1' unit='dbus-org.freedesktop.home1.service' requested by ':1.31' (uid=0 pid=689 comm="lightdm --session-child 12 19 ")
Sep 06 19:02:05 COMPUTERNAME dbus-daemon[381]: [system] Activation via systemd failed for unit 'dbus-org.freedesktop.home1.service': Unit dbus-org.freedesktop.home1.service not found.
Sep 06 19:02:05 COMPUTERNAME lightdm[689]: pam_systemd_home(lightdm:auth): systemd-homed is not available: Unit dbus-org.freedesktop.home1.service not found.
Sep 06 19:02:05 COMPUTERNAME audit[689]: USER_AUTH pid=689 uid=0 auid=4294967295 ses=4294967295 msg='op=PAM:authentication grantors=? acct="USERNAME" exe="/usr/bin/lightdm" hostname=? addr=? terminal=:0 res=failed'
Sep 06 19:02:05 COMPUTERNAME kernel: audit: type=1100 audit(1630947725.565:95): pid=689 uid=0 auid=4294967295 ses=4294967295 msg='op=PAM:authentication grantors=? acct="USERNAME" exe="/usr/bin/lightdm" hostname=? addr=? terminal=:0 res=failed'
Sep 06 19:02:07 COMPUTERNAME lightdm[689]: PAM 1 more authentication failure; logname= uid=0 euid=0 tty=:0 ruser= rhost=  user=USERNAME
Sep 06 19:02:15 COMPUTERNAME systemd[1]: systemd-hostnamed.service: Deactivated successfully.
Sep 06 19:02:15 COMPUTERNAME audit[1]: SERVICE_STOP pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-hostnamed comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
Sep 06 19:02:15 COMPUTERNAME kernel: audit: type=1131 audit(1630947735.295:96): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-hostnamed comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'

With your change, I got right in after pressing enter on an empty password.

EDIT: As the log states, there is a timeout reached, and yanking up the timeout in the Howdy config file from 4 seconds to 8 seconds did the trick.
I ought to have spotted that myself of course - but it seems I sometimes must empty all the drawers to find the key in my pocket :-p

Thanks for helping @loqs

Last edited by Ferdinand (2021-09-07 07:16:43)

Arch Linux

#1 2021-09-06 16:47:05

[SOLVED] Howdy face recognition

#2 2021-09-06 16:56:00

Re: [SOLVED] Howdy face recognition

#3 2021-09-06 17:28:15

Re: [SOLVED] Howdy face recognition

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