SSL Best Practices & Security Headers
Advanced configuration techniques for maximum SSL/TLS security
Having an SSL certificate is just the beginning. This guide covers advanced configurations and best practices to maximize your website's security posture and achieve A+ ratings on SSL tests.
Why Best Practices Matter
- Protect against evolving threats and vulnerabilities
- Improve performance with modern protocols
- Meet compliance requirements (PCI DSS, HIPAA)
- Build customer trust with visible security indicators
TLS Protocol Configuration
1. Use Modern TLS Versions
Disable outdated protocols vulnerable to attacks. Only enable TLS 1.2 and TLS 1.3.
Apache Configuration
Nginx Configuration
2. Configure Strong Cipher Suites
Use only secure cipher suites with forward secrecy. Prioritize AEAD ciphers.
# Modern cipher suite (TLS 1.3 + TLS 1.2)
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
3. Enable Forward Secrecy
Forward secrecy ensures past communications remain secure even if private keys are compromised.
Note: The cipher suites above (ECDHE) provide forward secrecy by default.
Essential Security Headers
1. HTTP Strict Transport Security (HSTS)
Forces browsers to use HTTPS and prevents protocol downgrade attacks.
Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
Start with a shorter max-age (300 seconds) and increase gradually to avoid lockout.
2. Content Security Policy (CSP)
Prevents XSS attacks by controlling which resources can be loaded.
Content-Security-Policy: default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval' https://trusted-cdn.com; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:;
3. X-Frame-Options
Prevents clickjacking attacks by controlling iframe embedding.
X-Frame-Options: SAMEORIGIN
4. X-Content-Type-Options
Prevents MIME type sniffing attacks.
X-Content-Type-Options: nosniff
5. Referrer-Policy
Controls how much referrer information is shared.
Referrer-Policy: strict-origin-when-cross-origin
Certificate Management Best Practices
Use Strong Key Sizes
Use at least 2048-bit RSA keys or 256-bit ECC keys for optimal security.
Implement Certificate Pinning
For high-security applications, pin certificates to prevent MITM attacks.
Monitor Certificate Transparency
Use CT logs to monitor for unauthorized certificate issuance.
Automate Renewal
Use tools like Certbot for Let's Encrypt or your CA's automation tools.
Performance Optimization
1. Enable OCSP Stapling
Improves performance by caching certificate status responses.
Apache
SSLUseStapling on
SSLStaplingCache "shmcb:logs/ssl_stapling(32768)"
Nginx
ssl_stapling on;
ssl_stapling_verify on;
2. Enable Session Resumption
Reduces TLS handshake overhead for returning visitors.
# Nginx example
ssl_session_cache shared:SSL:10m;
ssl_session_timeout 10m;
3. Use HTTP/2
Modern protocol with multiplexing and better performance.
listen 443 ssl http2;
Testing & Monitoring
Regular Testing
- Test configuration after any changes
- Use SSL Labs Server Test monthly
- Check for mixed content issues
- Monitor certificate expiration
Security Monitoring
- Monitor CT logs for certificates
- Track security header compliance
- Review access logs regularly
- Set up downtime alerts
Common Mistakes to Avoid
❌ Using outdated protocols: Never enable SSL 2.0, SSL 3.0, TLS 1.0, or TLS 1.1
❌ Weak cipher suites: Avoid RC4, 3DES, and export-grade ciphers
❌ Missing intermediate certificates: Always include the full certificate chain
❌ Ignoring security headers: Headers are as important as the certificate itself
Ready to Implement Best Practices?
Our security experts can audit your current configuration and implement industry best practices.
Sources & References
- 1 Mozilla SSL Configuration Generator:https://ssl-config.mozilla.org/(Accessed: July 15, 2025)
- 2 OWASP Secure Headers Project:https://owasp.org/www-project-secure-headers/(Accessed: July 15, 2025)
- 3 SSL Labs Server Test:https://www.ssllabs.com/ssltest/(Industry Standard Testing Tool)