Letsencrypt.org

Let's Encrypt Free SSL Certificates
Let's Encrypt - Free SSL/TLS Certificates

Let’s Encrypt is a free, automated, and open Certificate Authority.

Site: http://letsencrypt.org

Getting started
https://letsencrypt.org/getting-started/

Ubuntu
Install: sudo apt-get update sudo apt-get install software-properties-common sudo add-apt-repository universe sudo add-apt-repository ppa:certbot/certbot sudo apt-get update

sudo apt-get install certbot python-certbot-apache

Auto install certificates: sudo certbot --apache

Or just get a certificate: sudo certbot certonly --apache

Test automatic renewal: sudo certbot renew --dry-run

ref: https://certbot.eff.org/lets-encrypt/ubuntubionic-apache

CentOS
Install: wget https://dl.eff.org/certbot-auto sudo mv certbot-auto /usr/local/bin/certbot-auto sudo chown root /usr/local/bin/certbot-auto sudo chmod 0755 /usr/local/bin/certbot-auto

Auto install certificates: sudo /usr/local/bin/certbot-auto --apache

Or just get a certificate: sudo /usr/local/bin/certbot-auto certonly --apache

Automatic renewal: (crontab) echo "0 0,12 * * * root python -c 'import random; import time; time.sleep(random.random * 3600)' && /usr/local/bin/certbot-auto renew" | sudo tee -a /etc/crontab > /dev/null

ref: https://certbot.eff.org/lets-encrypt/centos6-apache

Renewal
/path/to/certbot-auto renew --dry-run /path/to/certbot-auto renew

Autoamted Renewal: 0 0,12 * * * python -c 'import random; import time; time.sleep(random.random * 3600)' && /path/to/certbot-auto renew

IMPORTANT NOTES: - Congratulations! Your certificate and chain have been saved at: /etc/letsencrypt/live/test.t0e.org/fullchain.pem Your key file has been saved at: /etc/letsencrypt/live/test.t0e.org/privkey.pem Your cert will expire on 2019-04-30. To obtain a new or tweaked version of this certificate in the future, simply run certbot-auto again with the "certonly" option. To non-interactively renew *all* of your certificates, run "certbot-auto renew" - Your account credentials have been saved in your Certbot configuration directory at /etc/letsencrypt. You should make a  secure backup of this folder now. This configuration directory will also contain certificates and private keys obtained by Certbot so  making regular backups of this folder is ideal. - If you like Certbot, please consider supporting our work by:

Donating to ISRG / Let's Encrypt:  https://letsencrypt.org/donate Donating to EFF:                   https://eff.org/donate-le