makecfw.sh

docker run --rm -v "$(pwd):/work" ubuntu:22.04 bash -c '
  set -e
  apt-get update && apt-get install -y whois
  cd /work

  mkdir -p mod
  tar xzf archive.tar.gz -C mod/

  cat >> mod/home/root/.ssh/authorized_keys << "KEYS"
<snip>
KEYS

  sed -i "s/PasswordAuthentication no/PasswordAuthentication yes/g" \
    mod/etc/ssh/sshd_config
  sed -i "s/PasswordAuthentication no/PasswordAuthentication yes/g" \
    mod/etc/ssh/sshd_config_readonly

  HASH=$(mkpasswd -m sha256crypt -S rodessh00 root)
  sed -i "s|^root:[^:]*|root:${HASH}|" mod/etc/shadow

  cd mod
  tar czf /work/archive-ssh.tar.gz .
'