Informing the SSH agent of the target user at server

[David Newall]

On 21/03/18 10:30, Damien Miller wrote:
> The downside of this design is that it blurs the trust boundary for
> ssh-agent; no longer would it be making decisions solely on its own - it
> would be trusting ssh not to lie to it about the remote destination.

That doesn't sound particularly bad to me.  Sure, the agent might try a
private key for the wrong destination, but that already happens. The
method you outlined sounds rather good.