Unable to negotiate key exchange method when using post-quantum algorithms

[ShiinYu]

When attempting to establish an SSH connection using post-quantum algorithms (classic-mceliece-348864-sha256 for KEX and ssh-mldsa44 for host keys), the connection fails with a key exchange negotiation error. The server responds with a list of supported algorithms that do not include the specified post-quantum methods.

Command Executed:
sudo /home/pqc/openssh/openssh/ssh -F /home/pqc/openssh/openssh/regress/ssh_config
-o KexAlgorithms="classic-mceliece-348864-sha256"
-o HostKeyAlgorithms=ssh-mldsa44
-o PubkeyAcceptedKeyTypes=ssh-mldsa44
-o PasswordAuthentication=no
-i regress/ssh-mldsa44
somehost true
Error Message:
Unable to negotiate with 127.0.0.1 port 4242: no matching key exchange method found.
Their offer: curve25519-sha256,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,
ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,
diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,kex-strict-s-v00@openssh.com

[dstebila]

Are you also using the OQS fork of OpenSSH on the server side? Both the client and the server need to have PQC support enabled.