Let’sEncrypt is a very nice tool to create free certificate for your site. With Let’sEncrypt you need to use domaine validation if you want to create wilcard certificate. In our case we host our zone on debian server with bind9. You can read our tutoriel to learn how you can make up bind9 . You have to know that let’sencrypt need to read TXT record in you zone to check if you are owner of this zone, this TXT record always have same name _acme-challenge.your_zone.fr but différent value for each renewal.

Firstly we will create the specific zone for let’sencrypt to make dynamics update on this zone with our script. login on your bind server and go to configuration directory (/etc/bind/), create let’sencrypt directory and HMAC configuration.