Hi,

with latest version of Ubuntu I’m getting an error when trying to connect with windows x2go client to Ubuntu 22.04 machine (I think it’s not so relevant that it’s ubuntu 22.04 but newer openssh version 8.9):

“kex error: no match for method kex algos:server [Diffie-hellman-group-exchange-sha256], client [curve255519-sha256@libssh.org,ecdh-sha2-nistp256,Diffie-hellman-group14-sha1,Diffie-hellman-group1-sha1]”

I have tried to adapt sshd_config via:

„HostKeyAlgorithms ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,ssh-ed25519-cert-v01@openssh.com,ssh-rsa-cert-v01@openssh.com,ssh-dss-cert-v01@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519,ssh-rsa,ssh-dss“

After that I have restarted sshd service but that did not help.

I also tried:

HostKeyAlgorithms ssh-rsa,ssh-dss

PubkeyAcceptedKeyTypes ssh-rsa,ssh-dss

The error message is the same. So I assume that the error is not what the message is telling me but I know that with some of the latest openssh versions several other clients run into problems (putty latest versions fixed it, jump desktop – setting PubkeyAcceptedKeyTypes=+ssh-rsa did work)

Any ideas?