nginx SSL configuration based on https://mozilla.github.io/server-side-tls/ssl-config-generator/

ssl.conf

# Updated from https://mozilla.github.io/server-side-tls/ssl-config-generator/
# on 2018-01-25

ssl_session_timeout 1d;
ssl_session_cache shared:SSL:50m;
ssl_session_tickets off;

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';
ssl_prefer_server_ciphers on;

ssl_dhparam /etc/nginx/ssl/dhparam.pem;

ssl_stapling on;
ssl_stapling_verify on;
resolver 8.8.8.8 8.8.4.4;
resolver_timeout 2s;

add_header Strict-Transport-Security "max-age=15768000;";
add_header X-Frame-Options DENY;
add_header X-Content-Type-Options nosniff;