However, I was wondering if anyone has ported/refactored the pkcs11 engine stuff for OpenSSL 3.0 already? is this on the TODO list for the OpenSC/pkcs11 team? If I wanted to try to refactor the opensc-pkcs11 module, how would I start?
PKCS #11 support is one (of many) possible items that will be considered for future versions of OpenSSL. The technical and management committees will be discussing which items are going to be worked on for the subsequent release in the not too distant future.
I'll also note that PKCS #11 considerations were prominent through the 3.0 design process. A PKCS #11 provider is expected to be possible with minimal (hopefully no) changes to the provider / libcrypto interface.
Pauli