This container can be pulled via:
  docker pull registry.opensuse.org/devel/bci/16.1/containerfile/suse/stunnel:5
  docker pull registry.opensuse.org/devel/bci/16.1/containerfile/suse/stunnel:5.76
  docker pull registry.opensuse.org/devel/bci/16.1/containerfile/suse/stunnel:5.76-18.1

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.