How to enable the integrated fingerprint reader with ThinkFinger
How to enable the fingerprint reader has a good explanation for using the fingerprint reader with the closed-source binary driver. But there is also an opensource project called ThinkFinger which does the same, but open.
However: The fingerprint reader is an INSECURE device and gives a false sense of security! There has been quite a bit of research by a hacker named Starbug, a member of the Chaos Computer Club, Berlin, Germany. He outlined in two very good talks how to forge each and every available fingerprint sensor available at the cost of a few euros, using materials from your local hardware store, a digicam and a laser printer! Here's some links:
Contents
Installing
From source
Download thinkfinger-0.3.tar.gz from the homepage and unpack it somewhere, make sure you have the gcc compiler, libtool, pkg-config, libusb-dev and libpam0g-dev installed, then:
$ cd thinkfinger-0.3
$ ./configure --prefix=/usr --sysconfdir=/etc --with-securedir=/lib/security --with-birdir=/etc/pam_thinkfinger
$ make
# make install
"make install" doesn't create the birdir we specified (where thinkfinger will store users' biometric info), so create it:
# mkdir /etc/pam_thinkfinger
If everything went OK assert that you find pam_thinkfinger.so in /lib/security typing:
$ ls /lib/security
From package
Debian
Packages arrived in Debian experimental on Aug 2nd, 2007 (cf. bug #409563). To access the experimental packages via apt, add the following lines to your sources.list:
# experimental deb ftp://mirrors.kernel.org/debian/ experimental main contrib non-free deb-src ftp://mirrors.kernel.org/debian/ experimental main contrib non-free
where of course you may replace mirrors.kernel.org with your mirror of choice. Just make sure that it hosts the experimental repositories.
aptitude update aptitude install libthinkfinger0 libpam-thinkfinger thinkfinger-tools
should then get you up and running.
Ubuntu
Hardy
Hardy includes the latest thinkfinger and it is up to date with subversion. Install packages:
$ sudo apt-get install thinkfinger-tools libpam-thinkfinger
Update the pam configuration files:
$ sudo /usr/lib/pam-thinkfinger/pam-thinkfinger-enable
Enroll your fingerprint (creates $HOME/.thinkfinger.bir). If this gives an error about claiming the USB device then reboot.
$ tf-tool --acquire
Check fingerprint enrollment
$ tf-tool --verify
You can expect everything to work correctly. Note that you still have to enter your username if prompted but will be able to swipe your finger instead of the password. The prompt will usually be "Password or swipe finger"
- Graphical login
- Text console login
- sudo
- screen lock/screen saver
- Administrative password prompt (eg for update or package managers). (Note no "or swipe finger" in prompt).
Gutsy
From https://wiki.ubuntu.com/ThinkFinger
Add PPA repositories to your sources.list:
deb http://ppa.launchpad.net/jldugger/ubuntu gutsy main restricted universe multiverse deb-src http://ppa.launchpad.net/jldugger/ubuntu gutsy main restricted universe multiverse
Install necessary packages:
$ sudo apt-get install thinkfinger-tools libpam-thinkfinger
Fedora/Fedora Core
- Packages for Fedora Core 6 are available in "extras" repository (# yum install thinkfinger).
- Packages for Fedora 7 are available in the "updates" repository (# yum install thinkfinger).
Gentoo
emerge sys-auth/thinkfinger
OpenSUSE
openSUSE 10.2 includes the package "libthinkfinger" (version 0.1-7) - you will find newer packages here.
Testing the driver
Now the driver is installed and should be working. You can try it (as root) with
# tf-tool --acquire
and
# tf-tool --verify
This will ask you to swipe your finger three times, save the fingerprint to /tmp/test.bir and then verify your fingerprint with the bir-file.
Configuring PAM to use ThinkFinger
Now you can configure PAM to use ThinkFinger:
Open /etc/pam.d/common-auth (In FC6, F7, and Gentoo, this file is /etc/pam.d/system-auth):
# nano -w /etc/pam.d/common-auth
Add this line before any pam_unix or pam_unix2 directives:
auth sufficient pam_thinkfinger.so
If your PAM uses the pam_unix and not the pam_unix2 module, you need to pass a specific argument in the /etc/pam.d/common-auth directive to make it consider the password entered at the pam_thinkfinger prompt.
auth required pam_unix.so try_first_pass
For instance, /etc/pam.d/common-auth looks like this:
auth sufficient pam_thinkfinger.so auth required pam_unix.so nullok_secure try_first_pass
On openSUSE 10.2, it looks like this now:
auth required pam_env.so auth sufficient pam_thinkfinger.so auth required pam_unix2.so
Now we are ready to add users to thinkfinger. You can add a fingerprint for a user with:
# tf-tool --add-user $USERNAME
Now the user should be able to login with his finger instead of the password.
If you would like to use thinkfinger for su, you have to enroll the fingerprint for root user with:
# tf-tool --add-user root
xscreensaver/gnome-screensaver
If you'd like to be able to unlock your screen using the fingerprint reader, you must have current versions of xscreesaver (>~5.03) or gnome-screensaver (>~2.18.2). Then you must give yourself access to the fingerprint reader and your bir-file, because unlike login/gdm/su/sudo, both gnome-screensaver and xscreensaver do not run as root. The following procedure will make the fingerprint reader accessible to members of the "fingerprint" group.
Make the group: # groupadd fingerprint
Save the following as /etc/udev/rules.d/60-thinkfinger.rules (you may need to reboot for this to take effect):
# # udev rules file for the thinkfinger fingerprint scanner # # gives access to the fingerprint reader to those in the "fingerprint" group # # Taken from: # http://www.thinkwiki.org/wiki/How_to_enable_the_fingerprint_reader_with_ThinkFinger # which was taken and modified from: # http://article.gmane.org/gmane.linux.drivers.thinkfinger/329 # # SGS Thomson Microelectronics Fingerprint Reader SYSFS{idVendor}=="0483", SYSFS{idProduct}=="2016", SYMLINK+="input/thinkfinger-%k", MODE="0660", GROUP="fingerprint" # the also-needed uinput device KERNEL=="uinput", MODE="0660", GROUP="fingerprint"
Finally, edit /etc/pam.d/gnome-screensaver so that it looks like this:
auth sufficient pam_thinkfinger.so auth required pam_unix.so try_first_pass nullok_secure
Per user:
- Add him to the group:
# gpasswd -a $USERNAME fingerprint - Make him owner of his bir-file:
# chown $USERNAME:root /etc/pam_thinkfinger/$USERNAME.bir - Give him read-only access to his bir-file:
# chmod 400 /etc/pam_thinkfinger/$USERNAME.bir - Give "execute only" access to everyone for the /etc/pam_thinkfinger/ directory:
# chmod o+x /etc/pam_thinkfinger(WARNING: this opens up security a little).
GNOME
gksu/gksudo doesn't work correctly. It just stays invisible. When starting a su privileged application such as synaptics you will not get prompted for the password. Nevertheless you can swipe your finger and it should authenticate you. Starting synaptics twice makes gksudo visible.
There are two possibilities to solve it:
- Changing the string "Password or swipe finger:" to a plain "Password:" (like sudo normally would do) in the file pam/pam_thinkfinger.c of the thinkfinger source directory. Of course, in the console you will then only see a "Password:" instead of "Password or swipe finger:" but this is still more usefull than having gksu/gksudo crashing everytime.
- Patching libgksu with the following patch. This is also a nasty hack until a better solution is implemented.
--- libgksu-2.0.3/libgksu/libgksu.c.orig 2007-06-17 16:00:24.000000000 +0200
+++ libgksu-2.0.3/libgksu/libgksu.c 2007-06-17 16:00:47.000000000 +0200
@@ -2663,7 +2663,7 @@
*/
for (counter = 0; counter < 50; counter++)
{
- if (strncmp (buffer, "GNOME_SUDO_PASS", 15) == 0)
+ if (strncmp (buffer, "GNOME_SUDO_PASS", 15) == 0 || strncmp (buffer, "Password or swi", 15) == 0)
break;
read_line (parent_pipe[0], buffer, 256);
@@ -2675,7 +2675,7 @@
if (context->debug)
fprintf (stderr, "brute force GNOME_SUDO_PASS ended...\n");
- if (strncmp(buffer, "GNOME_SUDO_PASS", 15) == 0)
+ if (strncmp(buffer, "GNOME_SUDO_PASS", 15) == 0 || strncmp(buffer, "Password or swi", 15) == 0)
{
gchar *password = NULL;
gboolean prompt_grab;
KDE
Integration in KDE and kdm seems not to be easily possible now. There is a filed bug at kde.org where you can vote for this.
Moreover, kdm in openSUSE 10.3 crashes when pam_thinkfinger is enabled. A possible "workaround" is downgrading to thinkfinger 0.2.2.
Another workaround is to use Fprint from [4] which works quite nicely on my X61s and Kubuntu Hardy.
This Howto was copied from Installing Ubuntu 6.06 on a ThinkPad T43#Fingerprint_Reader and then slightly modified.
