Installer un certificat SSL auto-signé

Activer mod_ssl

sudo a2enmod ssl & systemctl restart apache2

Créer un certificat SSL

sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout /etc/ssl/private/apache-selfsigned.key -out /etc/ssl/certs/apache-selfsigned.crt

Configurer Apache pour utiliser SSL

Dans chaque VirtualHost (/etc/apache2/sites-available/mon_site.conf, ajouter :

<VirtualHost *:443>
   ServerName your_domain_or_ip
   DocumentRoot /var/www/your_domain_or_ip

   SSLEngine on
   SSLCertificateFile /etc/ssl/certs/apache-selfsigned.crt
   SSLCertificateKeyFile /etc/ssl/private/apache-selfsigned.key
</VirtualHost>

Source : https://www.digitalocean.com/community/tutorials/how-to-create-a-self-signed-ssl-certificate-for-apache-in-ubuntu-20-04-fr (archive)