How to enable integrated fingerprint reader with BioAPI

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Revision as of 21:52, 29 August 2006 by Tec (Talk | contribs) (Installing the driver)
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This page describes the process of getting the integrated fingerprint reader to work under Linux, using bioapi and binary-only drivers. It is based on experiences in Ubuntu on a T43. The same works on Fedora 4 and 5, RHEL4, SuSE 9.3, SuSE 10, and Gentoo. Note that experimental open-source driver is available, see fingerprint reader page for details.

Basic installation

Installing the bioapi framework

Automated installation script

The Script for enabling the fingerprint reader automates the installation of most components (bioapi framework, driver, pam_bioapi, pam setup, device permissions, pamtester and enrolling), for some Linux distributions.

Binary packages

Note that these packages only take care of this one section. If you can use one, you should do so and then proceed to the section entitled, Installing and Configuring the Driver.

Debian/ Ubuntu Dapper
  • If you're using Debian Sid (the unstable branch) or Ubuntu Dapper Drake 6.06 LTS you can try the packages from Michael R. Crusoe's site, either version 1.2.3 (recommended) or older versions which might not work with the steps in this howto.
Ignore the warning about not finding /usr/lib/, it's not fatal.

You can either grab the ebuild, or use the source-install procedure below.

Also see for alternative documentation on installing on Gentoo including ebuilds for all the packages used.

Fedora Core

RPM packages for Fedora Core and installation instructions are available here

Installing from source

  • Get the bioapi source:
$ wget
  • I could not compile bioapi with the graphical Qt tools. To do it manually, do the following:
$ tar xjf bioapi-latest.tar.bz2
$ cd bioapi-1.2.2
$ ./configure --with-Qt-dir=no
$ make
and then as root
# make install
If make install fails, be sure you're root and then:
# export LD_LIBRARY_PATH=/usr/local/lib
# 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!
(I got through configure with Qt, but got a cryptic build error. It all worked fine with Qt disabled as above)
buzz: This is due to a wrong qt include path, set it manually in configure and everything should work.
  • Bioapi (at least version 1.2.2) doesn't compile with GCC4. You need to patch it:
  • This is neccessary to compile on SUSE 10.1 which it using gcc version 4.1.0.
$ wget
$ patch -p1 < bioapi-1.2.2-gcc4.patch
Create a dedicated directory, for example /opt/bioapi .
Append --prefix=/opt/bioapi to the above ./configure command.
Append /opt/bioapi/bin to $PATH and /opt/bioapi/lib to $LD_LIBRARY_PATH.
When installing the driver (below), tell it the new install path: # sh /opt/bioapi/lib

Adjusting ldconfigs library search path

At least on Fedora or Aurox Linux 11, you may need to add /usr/local/lib to the library path so that the libraries referenced from get picked up properly. The usual way to do this is adding it to the ldconfig configuration:

# echo '/usr/local/lib' > /etc/
# ldconfig

Alternatively you can add it to the LD_LIBRARY variable.

If you see bioapi libs in the output of

# ldconfig -p

then it should work.

Installing and configuring the driver

Installing the driver

  • Download from the UPEK support site and unzip it into a seperate folder, as it will not create one.
  • Change to that folder and do as root:
# sh
If you're running Gentoo or Ubuntu Dapper, use
# sh /usr/lib

For me it didn't wor this way, but following did:

sh /usr/local/lib

greetings, tec

If that fails, it may be that make install failed up above -- try setting LD_LIBRARY_PATH, do the make install again, and come back here and try this again. You also need mod_install from bioapi in your PATH.
May there still occures and error, which means mod_install: command not found.
Then login as root - not su!
Do this:
# sh
again. It should work. SU to root does not work since then the /usr/local/bin directory is not used per default.

Configuring permissions for non-root use

If you want to use PAM-aware applications like xscreensaver that are NOT running with root permissions (as opposed to login, gdm or other authentication mechanisms), you may need to do all or at least some of the things in this section. More details on what is necessary on which distributions would be greately appreciated.

  • Create two groups, one for access to BioAPI files and the other for access to the usb files. (This is done for full generality; i.e., you may have other USB devices which you want accessable to other users, without exposing your BioAPI configuration to them). Add your normal user (the one you wish to use PAM-aware applications with) to both of these groups.

On Debian this is done with

# addgroup --system bioapi
# addgroup --system usbfs
# adduser yournormaluser bioapi
# adduser yournormaluser usbfs

On SUSE this is done with

# groupadd --system bioapi
# groupadd --system usbfs
# groupmod -A yournormaluser bioapi
# groupmod -A yournormaluser usbfs

On Mandriva this is done with

# groupadd -r bioapi
# groupadd -r usbfs
# usermod -G bioapi,usbfs yournormaluser
(where yournormaluser is your normal user name). You will need to log out and log back in for this to take effect.
  • Set permissions on the BioAPI config/registry directory:
# chown -R root:bioapi /usr/local/var/bioapi/
# chmod -R 770 /usr/local/var/bioapi/
(change this path if you used an alternate BioAPI install directory above)
  • Set permissions on the files in /proc/bus/usb:
# chown -R root:usbfs /proc/bus/usb
# chmod -R g+X /proc/bus/usb
# chown root:usbfs /proc/bus/usb/`lsusb | sed -ne "/0483:2016/s/Bus\ \(.*\)\ Device\ \(.*\):\ .*/\1\/\2/p"`
# chmod 660 /proc/bus/usb/`lsusb | sed -ne "/0483:2016/s/Bus\ \(.*\)\ Device\ \(.*\):\ .*/\1\/\2/p"`
You may need to replace lsusb with its full path, which is something like /sbin/lsusb or /usr/bin/lsusb depending on your distro. It might be necessary to put these lines into a script which is run at startup and resume from suspend/hibernate.
  • As an alternative to the chown/chmod commands above, you can set mount options for usbfs with a line in /etc/fstab; an example would be
none /proc/bus/usb usbfs defaults,devgid=108,devmode=0660,busgid=108,busmode=0770,listgid=108,listmode=0660 0 0
where 108 is replaced with the numerical group ID of the usbfs group (you can determine this with something like cat /etc/group | grep usbfs | cut -d':' -f 3). Make sure you only have one /proc/bus/usb entry in /etc/fstab. See the mount(8) manpage for more information on these options. This is "cleaner" but seems to have a few weird issues -- see the talk page for details.
  • You may also have files in /dev/bus/usb, which the driver will try before /proc/bus/usb. If this is another usbfs mount point (mount shows a line containing /dev/bus/usb type usbfs), then simply follow the above instructions with /dev/bus/usb rather than /proc/bus/usb. Otherwise, you may be running a new kernel (i.e. 2.6.15) that makes usbfs-like files available through /dev/bus/usb.
  • On systems running udev these files are dynamically created; you can configure their permissions by editing a udev config file. On Debian this is done by changing the usb_device line of /etc/udev/permissions.rules to read
SUBSYSTEM=="usb_device", MODE="0660", GROUP="usbfs"
  • For the beta versions only, there is a logfile, which needs to exist with the proper permissions:
# touch /var/log/BSP.log && chown root:bioapi /var/log/BSP.log && chmod 660 /var/log/BSP.log

Miscellaneous configuration

  • To increase the security level (minimize false accept rate), set this in /etc/tfmessbsp.cfg:
Please see discussion section Security Level!

Testing the driver and enrolling a fingerprint

To test the driver and generate the file containing your fingerprint information, you need a sample program included with the driver. The compilation steps below were discovered by trial and error; if they don't work for you, try the binary Sample utility that came with the beta versions of the driver (i.e., as mentioned above). Go to the folder where you extracted and do:

# cd NonGUI_Sample
Edit main.c and remove (or comment out) the line
#include "port/bioapi_port.h"
# gcc -o Sample main.c -L/usr/local/lib -lbioapi100 -DUNIX -DLITTLE_ENDIAN
# ./Sample
Note that Sample may only run as root, unless you've already configured the usbfs file permissions.
You can try to "e"nroll (to record a fingerprint for an account) and then "v"erify (to test a fingerprint against the one it expects for an account).
You'll save a step later if you use your own login username as the username to enroll here.
If running ./Sample produces the error message 'BioAPI_ModuleLoad failed, BioAPI Error Code: 6477 (0x194d)'
then uncommenting the line
//BioAPI_SetGUICallbacks(gModuleHandle, NULL, NULL,TextGuiCallback, NULL);
in main.c can help.

Login via pam_bioapi

The following explains how to add fingerprint authentiation to programs that use the PAM (Pluggable Authentication Modules) framework, such as Gnome's GDM and KDE's KDM and screensaver.

Getting required libs & tools

Installing pam_bioapi

  • Prerequisites
On SuSE 10, I needed to install the pam-devel RPM
In general, you will need pam itself (standard for most distros) as well as the pam development files (probably an optional package for your distro).
  • Get and compile the pam_bioapi module.
A new version, pam_bioapi 0.3.0, with multi-finger and identification support can be found here.
$ wget
$ tar xjf pam_bioapi-latest.tar.bz2
$ cd pam_bioapi-0.2.1
$ wget
$ patch -p0 < fingerprint.patch
If you want to, review the patch. In general you should review all code you download and compile, if possible.
$ ./configure --libdir=/lib && make
and as root
# make install
If you get a 'rpl_malloc' error in /var/log/auth.log when trying to use the fingerprint reader, redo these steps and remove the related term from Makefile after running ./configure. (FC3, Debian etch)
  • If you get 'configure: error: cannot find required header: security/_pam_macros.h' and are on a Debian-like system, do "apt-get install libpam0g-dev" and try again. If you are using a Mandriva distribution, do "urpmi libpam0-devel" instead.
  • If you get 'PAM [dlerror: /lib/security/ undefined symbol: BioAPIMemoryFuncs]' error in your syslog, replace 'LIBS = ' line in libpam_bioapi/makefile with the following (of course, replace /opt/bioapi/ with the path where you installed bioapi):
LIBS = -L/opt/bioapi/lib -lbioapi100 -lbioapi_mds300 -lmds_util
  • 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:
# SERIAL=`BioAPITest | sed -ne "/Fingerprint/{n;n;s/^.*: \(.\{9\}\)\(.\{4\}\)\(.\{4\}\)\(.\{4\}\)\(.*\)/\1-\2-\3-\4-\5/gp}"`
# echo $SERIAL should print something like {5550454b-2054-464d-2f45-535320425350} now.
If it does, do:
# mkdir -p /etc/bioapi/pam/$SERIAL
# cp <username>.bir /etc/bioapi/pam/$SERIAL
If not, you might just try
# SERIAL={5550454b-2054-464d-2f45-535320425350}
as this value is hardcoded into the UPEK docs.

Configuring pam

The following part is distribution specific. On Ubuntu or SUSE you can modify /etc/pam.d/common-auth (on Gentoo and Fedora it is /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 {5550454b-2054-464d-2f45-535320425350} /etc/bioapi/pam/
password   sufficient {5550454b-2054-464d-2f45-535320425350} /etc/bioapi/pam/
auth       required nullok_secure

For Gentoo-Users - this allows you to attempt a password first. If you simply press enter, it then prompts for a fingerprints. Create a file named /etc/pam.d/bioapi. This also means that remote services, such as SSH keep working:

auth       required
auth       sufficient likeauth nullok
auth       sufficient {5550454b-2054-464d-2f45-535320425350} /etc/bioapi/pam/
auth       required

account    required

session    required
session    required

Now, simply replace "auth include system-auth" in all services that you wish to use fingerprint for with "auth include bioapi". For example, /etc/pam.d/kde by default contains

 auth       include      system-auth
 auth       required
 account    include      system-auth
 password   include      system-auth
 session    include      system-auth

Simply replace the first "system-auth" with bioapi and you can also get rid of KDE desktop lock with a fingerprint. If you do not wish to allow for "password fallback" then remove

auth       sufficient likeauth nullok

from /etc/pam.d/bioapi.

If su/sudo expects to receive the root password (SuSE 10), you need to have fingerprint settings for root (that is, copy in a root.bir as well as a your-username.bir). Otherwise, they get a segmentation fault. Which is a little unfortunate, given that you need to su or sudo to change your settings...
Not only SuSE 10 requires root.bir to be available for su to work. Just make sure you have root.bir when su is not working with your fingerprint reader but other applications are...

Note that sshd may pick up the fingerprint settings from /etc/pam.d/common-auth. I didn't want that, so I removed the "auth include common-auth" line from /etc/pam.d/sshd and replaced it with the lines that were originally in my /etc/pam.d/common-auth. That way most local services use the fingerprint reader, but sshd does not.

Another way to do this is to create a file (/etc/pam.d/bioapi for example) which contains the lines, and explicitly @include this before /etc/pam.d/common-auth in the files for services which should use the fingerprint reader. In this case you should leave /etc/pam.d/common-auth alone.

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

In Fedora the original 'session' terms in /etc/pam.d/system-auth need to be kept.

The setup described above will/could affect remote ssh logins to also use biometric logins, which is a bit silly (who wants to remote ssh to the laptop, and then have to walk over to it and swipe your finger)
To avoid that you can copy the default /etc/pam.d/system-auth to /etc/pam.d/sshd which will allow the sshd service to use the standard authentication procedure.

You can do some useful testing with pamtester, which calls the pam modules as if it were a program of your choice. Examples:

# pamtester xdm yourusername authenticate
$ pamtester xscreensaver yourusername authenticate

where yourusername is your username. Note that pamtester should run as root if and only if the program in question does.

Application support

The implementation of fingerprint scanning support in the relevant applications varies.

Here is the behaviour of the most common ones:

  • In gdm enter your username and there should pop up an (ugly) image to swipe your finger and... magic - you can login without a password.
  • kdm doesn't give any visual indication, other than that the cursor stops blinking. Just swipe your finger and hope it lets you log in.
  • In xdm, enter your username and a blank password, then swipe (there is no popup as well). Identification support for xdm can be achieved with this patch.
  • The KDE screen saver in SUSE 10 requires you to enter an empty password (or select the correct user and then enter an empty password) in order to get the fingerprint prompt.
  • For Fedora users, the redhat-config tools will crash if no root.bir presents. Also, there won't be any visual idication unless X server is properly configured for root to access. Just swipe your finger when the HDD stopped blinking or issue the following command in advance:
$ xhost +local:
  • For RHEL4 users gdm, console (virtual terminal) logins and the xscreensaver all work

kdm support

To add graphical popup to kdm, you need following:

  • Patch for pam_bioapi. This patch adds third parameter to module, which is a name of file with additional environment variables that will be supplied to the UPEK driver.
# wget
# patch -p1 < pam_bioapi-0.2.1-alter-environ.patch
  • Edit your Xsetup file (on SUSE 10 it's /etc/X11/xdm/Xsetup) and add these lines:
echo "XAUTHORITY=$XAUTHORITY" > /var/lib/xdm/kdm_env
echo "DISPLAY=$DISPLAY" >> /var/lib/xdm/kdm_env
  • In /etc/pam.d/xdm file, add /var/lib/xdm/kdm_env as a third parameter for module:
auth sufficient {5550454b-2054-464d-2f45-535320425350} /etc/bioapi/pam/ /var/lib/xdm/kdm_env

Please note, that this won't work if you have more than one Xserver.

Make xscreensaver use the scanner

If you are using Gentoo, you can get a portage overlay with the necessary patches here:

  • Get the needed xscreensaver sources:
$ wget
$ tar xzf xscreensaver-4.23.tar.gz
$ cd xscreensaver-4.23
$ wget
For xscreensaver 5.00, you can get a patch here:
  • After reviewing the patch (it's small and straightforward), do
$ patch -p1 < xscreensaver-4.22_alternativeAuth.diff
The patch prevents xscreensaver from opening an authentification window and dispatches the authentification request to another program, in our case pam and pam_bioapi. It should apply with some offset, don't mind that. If it says something about rejected though, then there's a problem.
  • Compile with
$ ./configure --with-pam && make
  • If you receive an error like "Couldn't find X11 headers/libs" and are running a Debian-like system, try "apt-get install xlibs-dev"
  • If you receive an error like "undefined reference to `XmuPrintDefaultErrorMessage'" then install the libxmu-dev package and run the previous line again and then install as root with
$ su -c 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 adjusting your PATH.