openssh unix dev - Sep 2021 - Loading (Only) a Cert Into the Agent

There was also a discussion on this topic earlier this year, with 
subject "Insert certificate into agent for existing key?"

https://marc.info/?l=openssh-unix-dev&w=4&r=1&s=insert+certificate+into+agent&q=b

On Fri, 10 Sep 2021, Brian Candler wrote:
> There was also a discussion on this topic earlier this year, with subject
> "Insert certificate into agent for existing key?"
> 
>
https://marc.info/?l=openssh-unix-dev&w=4&r=1&s=insert+certificate+into+agent&q=b
Yeah, addings just certificates to the agent requires protocol
extensions to match them against already loaded private keys. It's
messy and complicated in a piece of code that we really don't want
to be messy and complicated.

But you don't actually need to load a certificate into an agent to
use it with an agent! You can just have the private key in the agent
and specify CertificateFile in ~/.ssh/config or on the command-line
and ssh will match the private key to the certificate when it is time
to use it (well, it should anyway).

-d