This sounds like a great RFE @tomaszkrzyzanowski -- are you interested in providing a PR for this? I think wrapPrivateKey:

can be updated to return another string or int corresponding to the key type+length (either in transit format or otherwise just the raw number of bits).

If you move this cast earlier:

you can just call the Size() method. And then obviously importKeyToTransit would need to be updated accordingly:

https://github.com/notaryproject/notation-hashicorp-vault/blob/main/cmd/key-helper/importKey.go#L154

I don't know off the top of my head if Notary supports other types of keys (ECDSA?) but given the upcoming PQC standards, I'd imagine it'd want to start doing so... So perhaps returning the string would be most optimal and ECDSA/... support can be added more easily.

HTH!

@cipherboy I was already working locally on support for this and in #21 is what I have implemented with mostly standard libraries.

There were a few differences in how Notation and Vault defines names for ie. hash algorithms, and I tried to cover this with maps.

Moreover, when I started, I haven't had bigger awareness of notation-go library, and I'm thinking if it's fine to leave it as is or maybe reimplement this with notation-go/signature parts instead?

My code was mostly written before your suggestion about contribution, so I decided to show it as it is, but I can rework it accordingly to your description in previous message :)

BR,
Tomasz