I'm working on a small server written in Go to add short-lived user certificates to the forwarded agents of authorized users. https://github.com/rorycl/sshagentca This seems to work quite well for accessing sshd servers with the appropriately configured "TrustedUserCAKeys" directive. I have been in a debate about how similarly adding host certificates to forwarded agents could help mitigate man-in-the-middle attacks. This has raised a few questions. Firstly, given a host CA signing key on the sshagentca server, would an appropriately constructed host certificate added to a forwarded agent replace the necessity for a '@cert-authority' line in a user's known_hosts file? Secondly, would there be any alteration to the requirement for a "HostCertificate" CA-signed public key (from a private "HostKey") on sshd receiving servers? Many thanks Rory _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev