openssh – How retrieve or recreate a delete file from the /etc/ssh directory

In the /etc/ssh directory exists the following content:

moduli      sshd_config           ssh_host_ecdsa_key      ssh_host_ed25519_key      ssh_host_rsa_key      ssh_import_id
ssh_config  sshd_config.ucf-dist

I can see practically two categories:

  1. public/private keys
  2. configuration files

If any of those files for any of these categories is deleted by mistake.

How that file can be re-generated? Is possible?, How? it according of each category (1 or 2)