rpi-certbot

sudo sed -i "$ a\deb http://ftp.debian.org/debian jessie-backports main" /etc/apt/sources.list
sudo apt-get update
sudo gpg --keyserver pgpkeys.mit.edu --recv-key  8B48AD6246925553
sudo gpg -a --export 8B48AD6246925553 | sudo apt-key add -
sudo gpg --keyserver pgpkeys.mit.edu --recv-key  7638D0442B90D010
sudo gpg -a --export 7638D0442B90D010 | sudo apt-key add -
sudo apt-get install python-certbot-nginx