openssl req -new -days 365 -x509 -nodes -out /etc/pki/tls/certs/localhost.crt -keyout /etc/pki/tls/private/localhost.key
More information:
https://www.stevejenkins.com/blog/2010/08/renewing-a-self-signed-ssl-certificate-on-fedoracentos/ (https://www.stevejenkins.com/blog/2010/08/renewing-a-self-signed-ssl-certificate-on-fedoracentos/)