Vsftpd /etc/vsftpd.conf /var/log/xferlog
/var/log/syslog
Custom SSL Certificate
Bring your own Cert!
You can add your own cert of any third-party vendor or your preference.
sudo site example.com -ssl=on -ssl-key=/path/cert.key -ssl-crt=/path/cert.crt -ssl-ocsp=/path/cert.pem
The -ssl-ocsp parameter is optional for OCSP support.