openssl: Could not find private key of key from PK.key (TPM)

[m00nwtchr]

I'm trying to integrate sbctl with systemd-measure, as it would be nice if I could re-use the sbctl keys to sign the PCR policy as well. However, currently I'm stuck on trying to read the tpm-shielded private Platform Key file using openssl:

# openssl pkey -provider tpm2 -provider base -in PK.key -pubout -out testkey.pub
Could not find private key of key from PK.key
809BB60538750000:error:1608010C:STORE routines:ossl_store_handle_load_result:unsupported:crypto/store/store_result.c:151:

I confirmed that this command works with keys I've generated myself, but I can't get it to work with the sbctl created keys. (Except for normal file keys)

[Foxboron]

Probably this issue here: tpm2-software/tpm2-openssl#120