CDN SSL/TLS Configuration Best Practices: Balancing Security and Performance

guide covers certificate management, protocol versions, cipher suites, and best
practices.
seo_title: 'CDN SSL/TLS Configuration Best Practices: Security and Performance · 16IDC'
seo_keywords: CDN SSL configuration, TLS best practices, HTTPS optimization, certificate
management, CDN security
seo_description: 'CDN SSL/TLS best practices guide: certificate management, TLS protocol
version selection, cipher suite configuration, OCSP Stapling, and more.'
published_at: '2026-07-18'
status: active

CDN SSL/TLS Configuration Best Practices: Balancing Security and Performance

When CDNs handle HTTPS traffic, SSL/TLS configuration directly impacts both security and performance. A well-optimized TLS configuration can achieve both security and speed.

1. Certificate Selection and Deployment

1.1 Certificate Type Selection

| Certificate Type | Use Case | Validation Level | Cost |

1.2 Certificate Management on CDN

Automatic Certificate Management (Recommended):

Cloudflare: Auto SSL
AWS CloudFront: ACM auto-renewal
Azure: App Service managed certificates
Alibaba Cloud: Free DV certificates

Manual Certificate Management:

1. Purchase or generate certificate from CA
2. Upload to CDN console
3. Configure certificate chain (full chain)
4. Set up auto-renewal reminders

1.3 Let's Encrypt Integration

Most CDNs support automatic Let's Encrypt certificate issuance:

• Cloudflare: Built-in free certificate
• Bunny CDN: Auto Let's Encrypt
• AWS: Requires ACM import

2. TLS Protocol Version Configuration

2.1 Recommended Configuration

2.2 TLS 1.3 Advantages

Key improvements of TLS 1.3 over 1.2:

• Faster handshake: 1-RTT → 0-RTT
• More secure cipher suites: Removed insecure algorithms
• Connection time: Reduced by 1-2 network round trips

2.3 CDN Configuration Examples

Cloudflare: SSL/TLS → Edge Certificates → Minimum TLS Version: 1.2
CloudFront: Security Policy → TLSv1.2_2021
Nginx + CDN: ssl_protocols TLSv1.2 TLSv1.3;

3. Cipher Suite Configuration

3.1 Recommended Cipher Suites

# TLS 1.3 Cipher Suites (no configuration needed)
TLS_AES_128_GCM_SHA256
TLS_AES_256_GCM_SHA384
TLS_CHACHA20_POLY1305_SHA256

# TLS 1.2 Cipher Suites (recommended)
ECDHE-ECDSA-AES128-GCM-SHA256
ECDHE-RSA-AES128-GCM-SHA256
ECDHE-ECDSA-CHACHA20-POLY1305
ECDHE-RSA-CHACHA20-POLY1305

3.2 Insecure Cipher Suites (Disable)

TLS_RSA_WITH_AES_128_CBC_SHA
TLS_RSA_WITH_AES_256_CBC_SHA
All RC4, 3DES, CBC mode ciphers

4. Performance Optimization

4.1 OCSP Stapling

OCSP Stapling lets the CDN query certificate status on behalf of clients, reducing verification latency.

# Nginx Configuration
ssl_stapling on;
ssl_stapling_verify on;

4.2 SSL Session Resumption

Reduce handshake count through session reuse:

# Nginx Configuration
ssl_session_cache shared:SSL:50m;
ssl_session_timeout 1d;
ssl_session_tickets on;

4.3 HSTS Configuration

Enable HSTS to force HTTPS usage:

Strict-Transport-Security: max-age=31536000; includeSubDomains; preload

5. CDN Configuration Reference