nixos-config/sets/sshd.nix

{ config, pkgs, ... }:

{
  services.openssh = {
    enable = true;
    settings = {
      PermitRootLogin = "no";
      PasswordAuthentication = false;
      KbdInteractiveAuthentication = false;

      KexAlgorithms = [
        "sntrup761x25519-sha512@openssh.com"
        "curve25519-sha256"
        "curve25519-sha256@libssh.org"
      ];
      Macs = [
        "hmac-sha2-512-etm@openssh.com"
        "hmac-sha2-256-etm@openssh.com"
        "umac-128-etm@openssh.com"
      ];
    };

    extraConfig = ''
      TrustedUserCAKeys ${./ca.pub}
    '';
  };

  security.pam.ussh = {
    enable = true;
    caFile = ./ca.pub;
  };

  programs.mosh.enable = true;
}