NIOSSHError.keyExchangeNegotiationFailure

Hello, I am trying to SSH to a HPC server using this library, but trying to authenticate when connecting always gives me the above error. I have tried both password authentication and p521 key authentication to no avail.

Since I have been able to successfully use SwiftNIO SSH to execute a test command on another known server, I am sure my code runs correctly (it is also adapted from the NIOSSHClient example code from this repository). I am also able to SSH with a regular computer to the HPC server.

Running ssh -Q key on the HPC server gives the following:

>ssh-ed25519
ssh-ed25519-cert-v01@openssh.com
ssh-rsa
ssh-dss
ecdsa-sha2-nistp256
ecdsa-sha2-nistp384
ecdsa-sha2-nistp521
ssh-rsa-cert-v01@openssh.com
ssh-dss-cert-v01@openssh.com
ecdsa-sha2-nistp256-cert-v01@openssh.com
ecdsa-sha2-nistp384-cert-v01@openssh.com
ecdsa-sha2-nistp521-cert-v01@openssh.com

which is exactly the same as on the test server I have been able to connect to, and includes ed25519. Any ideas what the problem could be?

Start with the NIOSSHClient example code and compare its connection and authentication behavior against the known working server and the HPC server. Reproduce the keyExchangeNegotiationFailure while examining the SSH negotiation details and the server's supported keys; done means identifying the compatibility cause and confirming a successful connection or clearly documenting the unsupported case.

Written by the indexing model from the issue text.