ssl_protocols TLSv1.2;
ssl_ecdh_curve secp384r1;
ssl_ciphers ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256;
ssl_prefer_server_ciphers on;

ssl_session_cache shared:SSL:20m;
ssl_session_timeout 15m;
ssl_session_tickets off;

add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload";