nginx: be ready for a stronger ssl configuration.

nginx/defaults/main.yml

@@ -3,6 +3,8 @@ nginx_enabled: True
 nginx_use_ppa: False
 nginx_ppa_repo: ppa:nginx/stable
 nginx_package_state: installed
+# See https://mozilla.github.io/server-side-tls/ssl-config-generator/
+nginx_ssl_level: intermediate
 
 #nginx_virthosts: []
 
@@ -77,6 +79,8 @@ nginx_basic_auth_users:
 nginx_letsencrypt_managed: True
 nginx_websockets_support: False
 nginx_use_common_virthost: False
+# Set it to 'ssl http2' if the nginx version supports it
+nginx_ssl_type: ssl
 # When we do not use letsencrypt:
 # nginx_ssl_cert_file: '{{ pki_dir }}/certs/nginx.crt'
 # nginx_ssl_cert_key: '{{ pki_dir }}/keys/nginx.key'

nginx/tasks/nginx-config.yml

@@ -3,6 +3,16 @@
     - name: Create the snippets directory
       file: dest={{ nginx_snippets_dir }} state=directory
 
+    - name: Create the pki directory
+      file: dest={{ {{ pki_dir }}/nginx }} state=directory
+
+    - name: Create a dhparams file 2048 bits long
+      shell: openssl dhparam -out {{ pki_dir }}/nginx/dhparams.pem 2048
+      args:
+        creates: '{{ pki_dir }}/nginx/dhparams.pem'
+      when: nginx_ssl_level == 'intermediate'
+      notify: Reload nginx
+
     - name: remove nginx default virtualhost
       file: dest=/etc/nginx/sites-enabled/default state=absent
       notify: Reload nginx

nginx/templates/nginx-server-ssl.conf.j2

@@ -5,13 +5,27 @@ ssl_certificate_key {{ letsencrypt_acme_certs_dir }}/privkey;
 ssl_certificate {{ nginx_ssl_cert_file | default('/etc/nginx/ssl/server.crt') }};
 ssl_certificate_key {{ nginx_ssl_cert_key | default ('/etc/nginx/ssl/server.key') }};
 {% endif %}
-ssl_session_cache shared:SSL:10m;
-ssl_session_timeout 10m;
+ssl_session_cache shared:SSL:50m;
+ssl_session_timeout 120m;
+{% if nginx_ssl_level == 'intermediate' %}
+ssl_dhparam {{ pki_dir }}/nginx/dhparams.pem;
 ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
-ssl_ciphers "ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:ECDHE-RSA-DES-CBC3-SHA:ECDHE-ECDSA-DES-CBC3-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA";
+ssl_ciphers 'ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:ECDHE-ECDSA-DES-CBC3-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:DES-CBC3-SHA:!DSS';
+{% endif %}
+{% if nginx_ssl_level == 'modern' %}
+ssl_session_tickets off;
+# modern configuration. tweak to your needs.
+ssl_protocols TLSv1.2;
+ssl_ciphers 'ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256';
+{% endif %}
 ssl_prefer_server_ciphers on;
 {% if ansible_distribution_version | version_compare('14.04', '>=') %}
 ssl_stapling on;
 ssl_stapling_verify on;
+{% if letsencrypt_acme_install is defined and letsencrypt_acme_install %}
+ssl_trusted_certificate {{ letsencrypt_acme_certs_dir }}/fullchain;
+{% else %}
+ssl_trusted_certificate {{ nginx_ssl_fullchain_file | default('/etc/nginx/ssl/cacert.crt') }};
+{% endif %}
 add_header Strict-Transport-Security max-age=15768000;
 {% endif %}

nginx/templates/nginx-virthost.j2

@@ -99,9 +99,9 @@ server {
 
 }
 
-{% if item.ssl_enabled and item.ssl_only %}
+{% if item.ssl_enabled %}
 server {
-    listen {{ https_port | default(443) }} ssl;
+    listen {{ https_port | default(443) }} {{ nginx_ssl_type }};
     server_name {{ item.server_name }} {% if item.serveraliases is defined %}{{ item.serveraliases }}{% endif %};
     {% if item.access_log is defined %}
     access_log {{ item.access_log }};