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SSL Offloading with NGINX Blog

Written by Ashnik Team

NGINX | Feb 19, 2025

3 min read

SSL Offloading with NGINX: Best Practices for High-Performance Traffic

Imagine running an e-commerce platform during a major sales event, only to find your servers slowing down due to heavy SSL encryption. This is a common challenge for high-traffic applications, where secure connections can strain server resources. SSL offloading with NGINX helps alleviate this burden, allowing your backend servers to focus on delivering content and processing transactions efficiently. But how do you ensure it’s done right? In this guide, we’ll break down the best practices for SSL offloading with NGINX, ensuring optimal security and efficiency.

What is SSL Offloading?

SSL offloading is the process of handling SSL/TLS encryption and decryption on a dedicated proxy, like NGINX, rather than on the backend servers. This reduces the load on application servers, allowing them to focus on business logic and application processing.

For an in-depth understanding of SSL offloading, refer to the NGINX SSL/TLS Termination Guide.

Why Use NGINX for SSL Offloading?

  • Performance Boost: Reduces CPU load on backend servers by offloading encryption tasks.
  • Centralized Security Management: Handles SSL/TLS configurations in one place.
  • Optimized Traffic Handling: Enhances scalability and performance for high-traffic websites.
  • Flexibility: Allows for advanced configurations like SSL termination, re-encryption, and client authentication.

Best Practices for SSL Offloading with NGINX

Choose the Right SSL/TLS Version and Cipher Suites

Use strong and up-to-date SSL/TLS versions while disabling weaker protocols, such as SSL 3.0 and TLS 1.0, which are vulnerable to attacks like POODLE and BEAST. These older versions lack modern cryptographic safeguards, making them susceptible to interception and exploitation.

ssl_protocols TLSv1.2 TLSv1.3;
ssl_ciphers "EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH";
ssl_prefer_server_ciphers on;

For a detailed list of recommended cipher suites, check the Mozilla SSL Configuration Generator.

Enable HTTP/2 for Faster Secure Connections

HTTP/2 significantly enhances performance compared to HTTP/1.1 by allowing multiple requests and responses to be processed concurrently over a single connection. This eliminates the head-of-line blocking issue in HTTP/1.1, reduces latency, and improves page load times for secure websites.

Enable it in NGINX:

server {
listen 443 ssl http2;
server_name example.com;
ssl_certificate /etc/nginx/ssl/example.com.crt;
ssl_certificate_key /etc/nginx/ssl/example.com.key;
}

Learn more about HTTP/2 performance benefits in the NGINX Blog.

Use OCSP Stapling to Speed Up Certificate Validation

Reduce SSL handshake time by enabling OCSP stapling:

ssl_stapling on;
ssl_stapling_verify on;
resolver 8.8.8.8 8.8.4.4 valid=300s;
resolver_timeout 5s;

For OCSP stapling details, refer to the Let’s Encrypt OCSP Guide.

Enable Session Resumption to Optimize Handshake Performance

SSL session caching minimizes the need for repeated full handshakes by storing session parameters for a given client. When a returning client reconnects, NGINX can reuse the stored session details, avoiding the need for a full handshake. This reduces computational overhead and improves connection speed, particularly for high-traffic applications.

ssl_session_cache shared:SSL:50m;
ssl_session_timeout 1h;
ssl_session_tickets on;

Implement Strict Transport Security (HSTS)

Enforce HTTPS to prevent downgrade attacks:

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

Read more about HSTS in Google’s Web Security Documentation.

Optimize SSL Certificate Management

  • Use Let’s Encrypt for free, automated SSL certificates with Certbot.
  • Consider wildcard or multi-domain certificates to simplify management.
  • Automate renewal to prevent downtime using:
certbot renew --quiet

For more details, visit the Let’s Encrypt Documentation.

Load Balancing with SSL Offloading

For high-traffic applications, distribute traffic effectively with NGINX load balancing:

upstream backend {
server app1.example.com;
server app2.example.com;
}
server {
listen 443 ssl;
ssl_certificate /etc/nginx/ssl/example.com.crt;
ssl_certificate_key /etc/nginx/ssl/example.com.key;
location / {
proxy_pass http://backend;
}
}

Why? This ensures smooth traffic distribution, reducing server load.

For best practices on load balancing, refer to the NGINX Load Balancing Guide.

Conclusion

SSL offloading with NGINX is a game-changer for improving website performance and security. By using best practices like optimized cipher suites, OCSP stapling, session resumption, and HTTP/2, you ensure that encrypted traffic is handled efficiently without overloading backend servers.

Looking to enhance your security and performance further? Ashnik provides enterprise-grade SSL offloading solutions with tailored configurations, ensuring maximum efficiency and security for your infrastructure.

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