3 openssl req
-new -sha256 -key /etc
/ssl
/letsencrypt
/domain.key
-subj "/C=US/O=Acme/CN=sthu.org" -reqexts SAN
-config <(cat /etc
/ssl
/openssl.cnf
<(printf "[SAN]\nsubjectAltName=DNS:example.com,DNS:www.example.com")) -out /etc
/ssl
/letsencrypt
/domain.csr