How to enable integrated fingerprint reader with BioAPI

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Disclaimer: This is how I got the fingerprint reader on my T43 to work. It can _NOT_ yet be used to log me into the system. Working on that.

This is on Ubuntu Breezy.

The same works on Fedora Core 4.


Basic driver installation

Getting required libs and tools

Installing the bioapi source

  • Get the bioapi source:
$ wget http://www.qrivy.net/~michael/blua/bioapi/bioapi-1.2.2.tar.bz2
  • I could not compile bioapi with the graphical Qt tools. To do it manually, do the following:
$ tar xjf bioapi-1.2.2.tar.bz2
$ cd bioapi-1.2.2
$ ./configure --with-Qt-dir=no
$ make
and then as root
# make install
and if you want to compile pam_bioapi for auth later
# cp include/bioapi_util.h include/installdefs.h imports/cdsa/v2_0/inc/cssmtype.h /usr/include
Be aware that checkinstall will not work!

Installing the driver

# sh install.sh
# chmod 777 -R /usr/local/var/bioapi/
Actually this depends on where you installed, if you did as suggested, it should work. Otherwise you probably know what you're doing anyways. :)
# touch /var/log/BSP.log && chmod 666 /var/log/BSP.log
# chmod -R a+X /proc/bus/usb
# chmod 666 /proc/bus/usb/`lsusb | grep "0483:2016" | sed -e "s/Bus\ \(.*\)\ Device\ \(.*\):\ .*/\1\/\2/"`
It might be nessecary to put the above line into a startup script somewhere.

Testing the driver

Go to the folder where you extracted TFMESS_BSP_LIN_1.0beta2.zip and do:

# cd NonGUI_Sample
# chmod +x Sample
# ./Sample

If it doesn't work, ask for help at: t43fingerprint (at) badcode.de

GDM Login via pam_bioapi

Getting required libs & tools

Installing pam_bioapi

  • Get and compile the pam_bioapi module.
$ wget http://www.qrivy.net/~michael/blua/pam_bioapi/pam_bioapi-0.2.1.tar.bz2
$ tar xjf pam_bioapi-0.2.1.tar.bz2
$ cd pam_bioapi-0.2.1
$ wget http://badcode.de/downloads/fingerprint.patch
$ patch -p0 < fingerprint.patch
If you want to, review the patch. In general you should review all code you download and compile, if possible.

The patch comes from this thread.

$ ./configure && make
and as root
# make install
# cp /usr/local/lib/security/* /lib/security/
  • Use the sample tool from the fingerprint reader to create <username>.bir

<username> must be the username you want to login with, gdm will probably break for any login name that has no .bir file.

  • As root do:
# BioAPITest | grep -A2 Fingerprint | tail -n1 | cut -b 12-
It should print something like
{5550454b2054464d2f45535320425350}
If it does, do:
# mkdir /etc/bioapi1.10/pam`BioAPITest | grep -A2 Fingerprint | tail -n1 | cut -b 12-`
# cp <username>.bir /etc/bioapi1.10/pam/`BioAPITest | grep -A2 Fingerprint | tail -n1 | cut -b 12-`

Configuring pam

The following part is distribution specific. On Ubuntu you can modify /etc/pam.d/common-auth (on Gentoo and Fedora it is file /etc/pam.d/system-auth) to look like this: 

#
# /etc/pam.d/common-auth - authentication settings common to all services
#
# This file is included from other service-specific PAM config files,
# and should contain a list of the authentication modules that define
# the central authentication scheme for use on the system
# (e.g., /etc/shadow, LDAP, Kerberos, etc.).  The default is to use the
# traditional Unix authentication mechanisms.
#
auth    sufficient      pam_bioapi.so {5550454b-2054-464d-2f45-535320425350} /etc/bioapi1.10/pam/
password   sufficient   pam_bioapi.so {5550454b-2054-464d-2f45-535320425350} /etc/bioapi1.10/pam/
auth    required        pam_unix.so nullok_secure

With this modification pam immediatelly starts to use the fingerprint reader to do local authorization (e.g. sudo/gdm use the fingerprint reader).

NOTE!
This was discovered through trial and success, if it is plain wrong, wikorrect it, please.

Now gdm should pop up an (ugly) image to swipe your finger and... magic - you can login without a password.

On Fedora, I had to add /usr/local/lib to my LD_LIBRARY path so that the libraries referenced from pam_bioapi.so get picked up properly.

Make xscreensaver use the scanner

$ wget http://www.jwz.org/xscreensaver/xscreensaver-4.23.tar.gz
$ tar xzf xscreensaver-4.23.tar.gz
$ cd xscreensaver-4.23
$ wget http://nax.hn.org/pub/bioapi/xscreensaver-4.22_alternativeAuth.diff

After reviewing the patch (it's small and straightforward), do

$ patch -p1 < xscreensaver-4.22_alternativeAuth.diff

The patch should apply with some offset, don't mind that. If it says something about rejected though, then there's a problem.

This patch prevents xscreensaver from opening an authentification window and dispatches the authentification request to another program, in our case pam and pam_bioapi. Compile with

$ ./configure --with-pam && make

and then install as root with

# make install .

Make sure that the newly compiled xscreensaver is used

$ which xscreensaver should return
/usr/local/bin/xscreensaver .

In case it doesn't, try

$ export PATH=/usr/local/bin:$PATH

and retry.

$ xscreensaver-command -exit

kills your running instance of xscreensaver. Make sure you have the following line in your ~/.xscreensaver: 

alternativeAuth: True

now look at /etc/pam.d/xscreensaver. If you're on Ubuntu Breezy and you have already changed /etc/pam.d/common-auth you should be good to go. Otherwise check that the following line is at the top of the file: 

auth    sufficient      pam_bioapi.so {5550454b-2054-464d-2f45-535320425350} /etc/bioapi1.10/pam

start the new xscreensaver

$ xscreensaver

There should be a splash screen with version 4.23.

Now try with:

$ xscreensaver-command -lock

If you have questions or problems with this procedure, ask: t43fingerprint (at) badcode.de .

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