ssl 인증서 확인하기
echo | openssl s_client -showcerts -servername gnupg.org -connect hostname.tld:443 2>/dev/null | openssl x509 -inform pem -noout -text```
echo | openssl s_client -showcerts -servername gnupg.org -connect hostname.tld:443 2>/dev/null | openssl x509 -inform pem -noout -text```