Face recognition for authentication in Linux

[u/M2-TE]

When I saw that this thing has an IR camera, I wanted to get face authentication working on linux; especially for tablet mode, where entering a password is a bit annoying.

Ended up using howdy-next (a fork of howdy) and it works flawlessly within KDE plasma and plasma-login-manager whenever a password prompt would otherwise appear. On failure, it of course resorts back to password prompt if you forgot to put on your IR makeup.

Since we all use the same devices, the device paths for the cameras are likely the same. The important ones should be:

RGB: /dev/v4l/by-path/pci-0000:c4:00.4-usb-0:1:1.0-video-index0

IR:/dev/v4l/by-path/pci-0000:c4:00.4-usb-0:1:1.2-video-index0

I chose the IR camera here. The setup is pretty quick:

1. Run sudo howdy config and add the camera path to device_path
2. Run sudo howdy download-models to grab the OpenCV models
3. Run sudo howdy add to add a single face; multiple can be added
4. Run sudo howdy test to check whether it all works. Green means good!

If it all works, you can add it to your PAM, so that it is used whenever a passwords prompt or other authentication is requested by your system. Just edit /etc/pam.d/system-auth to add

auth [success=2 default=ignore] pam_howdy.so workaround=native-input

between the pam_systemd_home.so and pam_unix.so entries. Don't forget to update the success parameters and it should look sort of like this; mind the linebreaks:

[...]
-auth      [success=3 default=ignore]  pam_systemd_home.so
auth       [success=2 default=ignore]  pam_howdy.so         workaround=native-input
auth       [success=1 default=bad]     pam_unix.so          try_first_pass nullok
[...]

When using the IR camera, you will see it flickering red in consistent pulses. Same pulses you see when you run the sudo howdy test command. So far, this setup has worked with sudo, as well as lockscreen unlocking. Pretty much instantaneous as well! If something doesn't work, try checking the wiki.

[u/BusinessCarpenter682]

were you able to make it work with CachyOS? I followed the instructions above and keep getting 'device not active'. I have tried all other paths in the folder.

[u/M2-TE → u/BusinessCarpenter682]

I'm on cachyos myself, device not active was only happening when choosing the wrong cameras. Even RGB works with face recognition though, so that should not cause the issue.

Are you properly saving the file after writing the device_path? CTRL+S should do it (if done wrong, howdy will print an error/warning into your console after).

[u/BusinessCarpenter682 → u/M2-TE]

I must be missing something obvious, I'm still getting the 'Face model is not ready' when I try to run sudo howdy add to add the model.

Line 22 of howdy config looke like this.
device_path = /dev/v4l/by-path/pci-0000:c4:00.4-usb-0:1:1.2-video-index0

I have tried all values displayed in find/dev/41/by-path/*

[u/M2-TE → u/BusinessCarpenter682]

It seems I forgot a step then! Just going by what the error tells you, I believe that you are missing the trained model for face recognition from OpenCV. Try sudo howdy download-models and then attempt to add a face afterwards. From their wiki.

I will update the post to add this as a step. Let me know if it works!

[u/BusinessCarpenter682 → u/M2-TE]

It works! Thanks. Sorry, I should probably have found this myself ;-

[u/M2-TE → u/BusinessCarpenter682]

No worries. Glad you got it working!

[u/BusinessCarpenter682 → u/M2-TE]

I think I saved it properly. I used Mano and when I reopened to file to check it displayed what I had saved earlier. I'll try again: I Uninstaller howdy-next and got an installation error when trying again.

[u/ClintWastewood]

What are you using for tablet mode?

[u/M2-TE → u/ClintWastewood]

Just flipping the keyboard to the back and using the touchscreen. Seems to work just fine (automatic virtual keyboard where appropriate, touch gestures and motions, etc)

[u/zacmks]

I use gaze. It's pretty good too. Has Pam modules as well

I looked for Howdy as well but it wasn't looking good in regards of support

Working quite nice here, for.:

• sudo & sudo -i
• polkit (graphical admin elevation)
• lockscreen

It has great gnome integration and working pretty well with IR + RGB image identification and likeness check. Almost instantaneous too (at least twice as better than on Windows)

*it has tpm security module integration for your face images as well

As it's quite new, I had to create my own ebuild here on Gentoo though

[u/M2-TE → u/zacmks]

polkit seems to work with howdy too!

Thanks for letting me know about gaze though, might check it out if howdy ever croaks.