linux-fingerprint-drivers / Synaptics "Prometheus" via python-validity (USB 06cb:009a)
USB ID
06cb:009a
Source
devices/06cb:009a/README.md

Synaptics "Prometheus" via python-validity (USB 06cb:009a)

Status: Working via python-validity (userspace daemon, not a libfprint driver).

Synaptics/Validity "Prometheus" fingerprint readers. The python-validity driver covers 06cb:009a (Metallica MIS Touch) and the Validity 138a:0090, 138a:0097, 138a:009d family.

Overlap note: 138a:0090/138a:0097 also have a libfprint match-on-host driver entry at 138a:0090. python-validity is the match-on-chip userspace path and is usually the better bet for 06cb:009a and 138a:009d.

What was broken

These Synaptics "Prometheus" sensors use match-on-chip and an encrypted protocol that upstream libfprint does not implement.

What the fix does (architecture is different)

python-validity is not a libfprint driver. It is a reverse-engineered userspace daemon that talks to the sensor over DBus. It initialises the device, then registers itself with the open-fprintd service so that the normal fprintd clients and PAM modules work on top of it.

So the stack is: python-validity (device driver daemon) -> open-fprintd (fprintd-compatible DBus service) -> fprintd-clients / pam_fprintd.

There is also an unmerged upstream effort to support this family natively in libfprint: MR !579 ("validity: Add new driver for Validity/Synaptics VCSFW sensors", Draft).

Install

Packages exist for major distros (see CREDITS):

Install open-fprintd, python3-validity, and fprintd-clients together, then:

sudo systemctl start python3-validity
fprintd-enroll        # plain fprintd clients work via open-fprintd
fprintd-verify

Note: on some units the sensor's storage must be initialised/cleared first; see the project's docs for validity-sensors-firmware and dbus-init steps.

PAM setup

Once open-fprintd is running, configure PAM exactly as for normal fprintd (distro helper or auth sufficient pam_fprintd.so); see docs/BUILD.md. The build sections of that guide do not apply here, since python-validity is packaged rather than built.

Tested on

License note

python-validity is MIT-licensed (compatible with this hub's scope). It is listed here as the canonical working fix even though it is a userspace daemon rather than a libfprint driver.