ssl_certificate /config/keys/letsencrypt/fullchain.pem;
    ssl_certificate_key /config/keys/letsencrypt/privkey.pem;
    ssl_dhparam /config/keys/dhparam.pem;

    ssl_session_timeout 1d;
    ssl_session_cache shared:MozSSL:10m;
    ssl_session_tickets off;

    # modern configuration
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_prefer_server_ciphers on;
    ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384;
    ssl_ecdh_curve X25519:prime256v1:secp521r1:secp384r1;

    # OCSP stapling
    ssl_stapling on;
    ssl_stapling_verify on;

    # verify chain of trust of OCSP response using Root CA and Intermediate certs
    ssl_trusted_certificate /config/keys/letsencrypt/fullchain.pem;

    # replace with the IP address of your resolver
    resolver 127.0.0.11;
    resolver_timeout 2s;

    # HSTS (ngx_http_headers_module is required) (63072000 seconds)
    add_header Strict-Transport-Security "max-age=63072000; includeSubDomains" always;

    # Security Headers
    add_header Referrer-Policy "no-referrer-when-downgrade" always;
    add_header Content-Security-Policy "upgrade-insecure-requests" always;
    add_header Cache-Control "no-transform" always;
    add_header X-UA-Compatible "IE=Edge" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-XSS-Protection "1; mode=block" always;