USB Fingerprint reader Linux
 

Sorry for the thread necromancy but this is one of the first results that pops up when you search for "USB Fingerprint reader Linux".

The advice to check the fprint Supported Devices is good, but there you'll find only a list of USB IDs that are quite difficult, at least for me, to be mapped to real products.

I just want to share that I have finally found a (cheap) product that uses one of the supported USB IDs, the "Benss USB Fingerprint Reader (UA002)".
The one I got came with the USB ID 04f3:0c28 but I saw on other reviews of the product that also uses the USB ID 04f3:0c26.

On Ubuntu 20.04 was recognized automatically and to enable the login with fingerprint I simply followed the official Wiki instructions:

1. Open the Activities overview and start typing Users.
2. Click on Users to open the panel.
3. Press on Disabled, next to Fingerprint Login to add a fingerprint for the selected account. If you are adding the fingerprint for a different user, you will first need to Unlock the panel.
4. Select the finger that you want to use for the fingerprint, then Next.
5. Follow the instructions in the dialog and swipe your finger at a moderate speed over your fingerprint reader. Once the computer has a good record of your fingerprint, you will see a Done! message.
6. Select Next. You will see a confirmation message that your fingerprint was saved successfully. Select Close to finish.

After verifying that the login via fingerprint worked, I enabled the pam authentication as well:
One very important thing I figure out while checking the images is that I got the best result while swiping the finger from the joint to the tip of the phalanx, with the reader logo/led facing the joint.

Anyway I just wanted to share this information because I was looking for it literally for years.

lsusb: