Maven

Various IBM/Lenovo ThinkPad notebooks contain interesting feature – fingerprint reader. It is possible to use it under Linux for authentication. Thanks to PAM module we can easily use fingerprint reader to biometrically authenticate various apps.

Installation

To get fingerprint reader working under Linux (PLD/Linux in this case) we need:

• BioAPI (reference implementation of BioAPI framework for unix systems). For PLD/Linux see bioapi.spec.
• TouchChip TFM/ESS driver from Upek, Inc. tfm-fingerprint.spec for PLD/Linux.
• PAM BioAPI module. pam-pam_bioapi.spec for PLD/Linux.

Usage

Sample programs from BioAPI implementation will allow you to verify if fingerprint reader works correctly and will allow to dump your fingerprints data into *.bin files. *.bin files are later used to verify if fingerprint is correct one.

Example PAM configuration for sudo with authentication done through BioAPI:

[root@tarm ~]# cat /etc/pam.d/sudo
#%PAM-1.0
auth sufficient pam_bioapi.so {5550454b-2054-464d-2f45-535320425350} /etc/bioapi/pam/
auth required pam_unix.so
account required pam_unix.so
password required pam_cracklib.so difok=2 minlen=8 dcredit=2 ocredit=2 retry=3
password sufficient pam_bioapi.so {5550454b-2054-464d-2f45-535320425350} /etc/bioapi/pam/
password required pam_unix.so md5 shadow use_authtok
password required pam_make.so /var/db
session required pam_unix.so
session required pam_env.so
session required pam_limits.so change_uid

(/etc/bioapi/… contains *.bin files with scanned fingerprints)

How it works?

[arekm@tarm ~]$ sudo zsh
Verification start
Put finger

When the finger was moved too fast:

Swipe too fast
Put finger

When the scan had bad quality (I just moved my finger quite fast and not in correct way):

Bad quality
Put finger

The finger was passed over right side of sensor only:

Finger is too right
Put finger

Correct scan, finger passed properly:

Image processing
Scanned good image
Operation succeeded
[root@tarm ~]#

Example of unlocking KDE lock screen:

Interesting links:

ThinWiki article about ThinkPad FingerPrint reader.

2007-01-18 UPDATE:
There is open source implementation that is able to use fingerprint device in thinkpads:
ThinkFinger