Generate certificate StartSSL for virtual hosts in Apache

openssl req -new -newkey rsa:2048 -nodes -out /etc/ssl/user.zviretnik.csr -keyout /etc/ssl/private/user.zviretnik.key -subj "/C=CZ/ST=cs/L=Praha/O=/CN=user.zviretnik.eu"
chmod 640 /etc/ssl/private/user.zviretnik.key

https://www.startssl.com/

copy StartSSL certificate to:
touch /etc/ssl/user.zviretnik.cer

Show content of CSR:
openssl req -in user.zviretnik.csr -noout -text