I regularly find myself in need of generating a quick SSL key and certificate pair. I've been using a one-liner for a while to generate these certificates. No annoying user prompts just a quick fast certificate pair.
echo -e "XX\n\n \n \n\n$(hostname)\n\n" | openssl req -new -x509 -newkey \ rsa:2048 -keyout service.key -nodes -days 90 -out service.crt &> /dev/null
The cert uses the hostname of whatever machine you generated it on. It should under no circumstances be used for a production service. It's a 2048 bit key and only valid for for roughly three months.