Thanks for opening an issue! Yep, this is definitely something that's currently missing. We'll need to add it.

Do you mind giving a bit of insight into the use case? You have keys you'd like to use, that much I understand. But is that a requirement from some other software? Is it because step isn't able to generate the exact keys you want to use?

For sure! I was investigating options for cross-signing intermediate CAs and just exploring the tooling you all have created. It's been a pleasure to work with btw!

Hey, that's very kind, thanks!

Currently this is on our mid-term roadmap. But if it becomes a blocker for you, please let us know and we can see about fast-tracking it.

And, if anyone finds this and is looking for ways to contribute, we definitely encourage PRs from the community and are happy to help with guidance. There are a number of commands in the cli that take pub and priv key arguments, so there are plenty of examples to work from.