linux-fingerprint-drivers / Validity / Synaptics VFS0090 (USB 138a:0090, 138a:0097)
USB ID
138a:0090, 138a:0097
Source
devices/138a:0090/README.md

Validity / Synaptics VFS0090 (USB 138a:0090, 138a:0097)

Status: Working via the established out-of-tree vfs0090 driver.

Validity Sensors (now Synaptics) fingerprint reader, found in 2016-era ThinkPad laptops. This entry covers 138a:0090 and 138a:0097.

What was broken

Upstream libfprint has no native driver for these Validity readers; the protocol had to be reverse engineered. They are unrecognised by stock libfprint.

What the fix does

Adds a vfs0090 driver that does match-on-host: it captures images from the sensor and matches them using libfprint's image comparison algorithm. Most of the device interaction and crypto comes from the Validity90 reverse-engineering prototype.

Note: for 138a:0097, match-on-chip is the only supported path on some firmware; behaviour can vary by unit.

There is also an unmerged upstream effort for this sensor family: libfprint MR !579 ("validity: Add new driver for Validity/Synaptics VCSFW sensors", Draft; covers 138a:0090/0097/009d and 06cb:009a).

Build and install

The driver lives on the vfs0090 branch of 3v1n0's libfprint fork (see CREDITS). Packaged builds exist:

From source:

git clone https://github.com/3v1n0/libfprint
cd libfprint
git checkout vfs0090
meson setup builddir --prefix=/usr
meson compile -C builddir
sudo meson install -C "$PWD/builddir"
sudo ldconfig

Then restart fprintd and enroll:

sudo pkill -9 -x fprintd
fprintd-list "$USER"
sudo fprintd-enroll "$USER"

PAM setup

Enable fprintd in your PAM stack: distro helper where there is one, otherwise auth sufficient pam_fprintd.so. Never required. Full steps per distro are in docs/BUILD.md.

Tested on

Packaged route (Arch)

The AUR package libfprint-vfs009x-git builds libfprint with the libre vfs0090 and vfs0097 drivers, which is the quickest way onto this driver on Arch without managing your own fork.