I am doing some tests around ssh. From what I have seen a server usually has multiple host keys. When a client tries to connect, it tries to negotiate which key types to use
ECDSA, etc. But on key signature confirmation by the user, those host keys are added to
This brings up my problem:
I am sure I saw in
known_hosts keys for github both for
ed25519). Now when I connect to github it only adds the
RSA key. If I tweak the preferred algorithm with
HostKeyAlgorithms and set it to
ed25519 only, it obviously refuses to connect with
WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!.
I tested with a local openssh server and indeed it adds all the host keys. Why does github behave differently?
Host * ServerAliveInterval 60 HostKeyAlgorithms rsa-sha2-512,rsa-sha2-256,ssh-ed25519