feat(cert-create): add pkcs11 engine support

Add pkcs11 engine support which allows using keys that are securely
stored on a HSM or TPM. To use this feature the user has to supply
an RFC 7512 compliant PKCS11 URI to a key instead of a file as an
argument to one of the key options. This change is fully backwards
compatible.

This change makes use of the openssl engine API which is deprecated
since openssl 3.0 and will most likely be removed in version 4. So
pkcs11 support will have to be updated to the openssl provider API
in the near future.

Signed-off-by: Robin van der Gracht <robin@protonic.nl>
Change-Id: If96725988ca62c5613ec59123943bf15922f5d1f
6 files changed