When configuring Nginx for optimal SSL/TLS performance, you might encounter this warning during configuration testing or server reload:

nginx: [warn] "ssl_stapling" ignored, no OCSP responder URL in the certificate

This occurs when your SSL certificate doesn't contain the necessary Authority Information Access (AIA) extension that specifies the OCSP responder URL. Let's break down why this happens and how to resolve it.

First, verify whether your certificate supports OCSP stapling by examining it with OpenSSL:

openssl x509 -in your_domain.crt -noout -text | grep -i "OCSP"

If you don't see output containing "OCSP" or a CA Issuers URI, your certificate wasn't issued with OCSP capabilities. This is common with some certificate authorities or certain types of certificates.

Here are your options when facing this situation:

Option 1: Request a New Certificate with OCSP Support

Contact your certificate provider and request a reissue with proper OCSP responder information. Most modern CAs include this by default.

Option 2: Implement Alternative Validation Methods

If you can't get a new certificate, consider these alternatives in your Nginx config:

# Disable stapling for this certificate
ssl_stapling off;

# But keep other security optimizations
ssl_session_cache shared:SSL:10m;
ssl_session_timeout 10m;
ssl_session_tickets off;

If you do have OCSP support, here's a complete working configuration:

server {
    listen 443 ssl;
    server_name example.com;
    
    ssl_certificate /etc/ssl/certs/example.com.crt;
    ssl_certificate_key /etc/ssl/private/example.com.key;
    
    # OCSP Stapling Configuration
    ssl_stapling on;
    ssl_stapling_verify on;
    resolver 8.8.8.8 8.8.4.4 valid=300s;
    resolver_timeout 5s;
    
    # Chain of trust verification
    ssl_trusted_certificate /etc/ssl/certs/ca-bundle.crt;
    
    # Other recommended SSL settings
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_prefer_server_ciphers on;
    ssl_ciphers 'ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256...';
}

After implementing changes, verify with:

nginx -t
systemctl reload nginx

Check if stapling works using OpenSSL:

openssl s_client -connect example.com:443 -status -servername example.com -tlsextdebug 2>&1 | grep -i "OCSP"

---

When configuring OCSP stapling in Nginx, you might encounter this warning in your error logs:

nginx: [warn] "ssl_stapling" ignored, no OCSP responder URL in the certificate

This occurs when your SSL certificate doesn't contain the necessary Authority Information Access (AIA) extension that specifies the OCSP responder URL. Without this URL, Nginx cannot perform OCSP stapling, even if you've properly configured ssl_stapling on in your server block.

First, check if your certificate actually supports OCSP by examining its details:

openssl x509 -in your_certificate.crt -noout -text | grep -A 4 "Authority Information Access"

If you don't see an OCSP URL in the output, your certificate wasn't issued with OCSP capabilities. You'll need to request a new certificate from your CA that includes this information.

For certificates that do support OCSP, here's a complete configuration example:

server {
    listen 443 ssl;
    server_name example.com;
    
    ssl_certificate /etc/ssl/certs/example.com.crt;
    ssl_certificate_key /etc/ssl/private/example.com.key;
    
    # OCSP Stapling configuration
    ssl_stapling on;
    ssl_stapling_verify on;
    
    # Use trusted certificate chain for verification
    ssl_trusted_certificate /etc/ssl/certs/ca-bundle.crt;
    
    # DNS resolver configuration
    resolver 8.8.8.8 8.8.4.4 valid=300s;
    resolver_timeout 5s;
}

1. Missing Intermediate Certificates: Ensure your ssl_trusted_certificate file contains the full chain including root and intermediate certificates.

2. DNS Resolution Issues: Nginx needs DNS resolution to reach the OCSP responder. Test connectivity with:

dig +short ocsp.your-ca.com

3. Certificate Renewal: Some CAs only include OCSP information when explicitly requested during certificate issuance.

After implementing changes, verify OCSP stapling is working:

openssl s_client -connect example.com:443 -status -tlsextdebug </dev/null 2>&1 | grep -i "OCSP response"

You should see output indicating a valid OCSP response if stapling is working correctly.

If you can't obtain a certificate with OCSP information:

• Consider switching to a CA that provides OCSP-enabled certificates by default
• Implement short-lived certificates with automated renewal
• Use a CDN that handles OCSP stapling for you