Support SoftHSMv2 sql database format

[abbra]

Allow reading/writing in SoftHSMv2 sql database format to provide transparent migration path.

This would help FreeIPA to migrate existing environments where we use SoftHSM for DNSSEC to use kryoptic without forcing data migration.

[simo5]

@abbra do we have a spec for their format somewhere?

[abbra]

I'm afraid there is no a particular specification anywhere. Design for SoftHSMv2 only has this: https://wiki.opendnssec.org/softhsm2-design/#secure-object-store. The original implementation was added in 2013 by softhsm/SoftHSMv2@9d4acf2 and the interface is largely the same.

src/lib/object_store is where the code is. DB.cpp, DBObject.cpp and DBToken.cpp are implementation of the database interface, DB objects, and tokens represented as DB objects.

There is also a dump program that allows to dump existing database, SQL variant is implemented in src/bin/dump/softhsm2-dump-db.cpp. This might be interesting because it does not use the object store and operates on the SQL level directly.