In commit 5c28654d9 ("goodixmoc: Fix print template parsing") the length
check for the verify and duplicate check responses by requiring two
extra bytes at the end of the message.
There were also issues in other places where the length was not checked
correctly, including a scenario that could cause a read beyond the end
of the buffer.
Related: #444
* Allow FPI_PRINT_NBIS to be extended rather than overridden if a user
supplies an existing FpPrint template with data;
* Prints will only be extended if a device has the required feature.
For image-based devices this feature is added by default since they
typically do not have storage (this can be overridden at the child
class level).
Extending an existing FpPrint requires passing a template print with
existing data during the enrollment process. This is done because the
caller is responsible for maintaining the fingerprint database and doing
the necessary deserialization operations if needed. The existing
example program is updated to show how to do that.
This ensures that we have processed all hotplug events before
considering enumeration to be complete. This is important due to USB
persist being turned off. At resume time, devices will disappear and
immediately re-appear. In this situatoin, enumerate could first see the
old state with a removed device resulting in it to not be discovered.
As a hotplug event is semingly emitted by the kernel immediately, we
can simply make sure to process this hotplug event before returning
from enumerate.
Closes: fprintd#119
The length is only a single byte in the transfer. However, the struct
had a uint32_t in that place, breaking the sizeof() calculation and
seemingly creating issues for certain lengths of user id strings (which
depend on the username).
Fix this by changing the type to uint8_t. Also add the initial 0x43
prefix byte and a byte of apparent padding that the struct contains.
Leave the two reserved bytes at the end, as they seem to actually have a
meaning (i.e. they are seemingly send in listings).
This effectively makes the struct one byte smaller, bringing it down to
127 bytes from 128 bytes.
Closes: #428, #404
While useful, there are advantages for this to be done by the
surrounding code (i.e. fprintd). As such, remove the identify stage from
the goodix driver and rely on fprintd doing it for us.
One can probably argue that neither solution is perfect. Ideally, we
would probably return the information required to delete the old print
to the upper stack and let the driver/device handle the duplicate
checking.
However, for now this works well. We may need to reconsider this if we
get devices that do the duplicate checking transparently and just throw
an enroll error.
NOTE: The driver did not report any progress for the identify step. As
such, the number of enroll steps reported by the device remain the same.
Closes: #415
Benjamin Berg