config/systems/mdesktop/ssh.nix

{ config, ... }:

{
  services.openssh = {
    enable = true;
    settings = {
      PermitRootLogin = "no";
      PasswordAuthentication = false;
      KbdInteractiveAuthentication = false;
    };
  };
  programs.ssh.hostKeyAlgorithms = [ "sk-ssh-ed25519@openssh.com" "ssh-ed25519" ];
}