Enforce HTTPS with HSTS in Nginx

server {
    listen 443 ssl http2;
    server_name your_domain.com www.your_domain.com;

    ssl_certificate /etc/nginx/ssl/your_domain.com.crt;
    ssl_certificate_key /etc/nginx/ssl/your_domain.com.key;
    ssl_session_timeout 1d;
    ssl_session_cache shared:SSL:10m;
    ssl_session_tickets off;

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

    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers 'TLS_AES_128_GCM_SHA256:TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256';
    ssl_prefer_server_ciphers off;

}

server {
    listen 80;
    server_name your_domain.com www.your_domain.com;
    return 301 https://$host$request_uri;
}

How it works: This Nginx configuration snippet demonstrates how to implement HTTP Strict Transport Security (HSTS). Placed within the HTTPS server block, the `add_header Strict-Transport-Security` directive instructs browsers to *only* access your domain over HTTPS for a specified `max-age` period (here, 1 year). This helps prevent downgrade attacks (where attackers force connections to insecure HTTP) and protects against cookie hijacking, significantly enhancing user security. The `includeSubDomains` and `preload` directives further extend this protection to subdomains and enable inclusion in browser-level HSTS lists, respectively. A corresponding HTTP server block is also shown to redirect all initial HTTP requests to HTTPS.