libccid (https://packages.debian.org/buster/libccid) uses a hard-coded list of supported devices, and the Librem Key is not listed in it.
As such, tools that depend of libccid, like opensc-pkcs11 (https://packages.debian.org/buster/opensc-pkcs11) for PKCS#11 do not recognize the Librem Key.
Current status of this: Our patch sent upstream has been merged, and libccid 1.4.32 now supports the Librem Key out of the box. This version is already available in PureOS Byzantium, Debian testing, and any distro that has version 1.4.32 of this package.
We still need to check if we have interest in backporting this patch to Amber
The current workaround is to manually edit the libccid list of supported devices and add the Librem Key: Friendly Name, Vendor ID and Device ID.
after libccid is installed, the file with the list of supported devices can be found at: /etc/libccid_Info.plist
And adding the following strings:
add: <string>Librem Key</string>
After rebooting the machine, libccid will recognize the Librem Key
Long term solution:
We need to submit an upstream patch to libccid at: https://salsa.debian.org/rousseau/CCID
The workflow to request to the developers adding support for a new device is explained here: https://ccid.apdu.fr/#CCID_compliant