Expired SSL Certificate

Question

Your production website is suddenly showing SSL errors for users. How do you troubleshoot and fix this?

Accepted Answer

Experiencing SSL errors on a production website is a critical issue that requires immediate and systematic troubleshooting. My approach would focus on quickly identifying the root cause to minimize user impact and restore service. First, I'd verify the most common culprit: certificate expiration. I would use tools like `openssl s_client -connect yourdomain.com:443 -servername yourdomain.com` or simply inspect the certificate details in a browser to check its validity dates. If expired, this immediately becomes the priority. Next, I would confirm the entire certificate chain is valid and correctly installed. This involves checking if the server's certificate, intermediate certificates, and the root certificate are all present and trusted by browsers. Missing or incorrect intermediate certificates are a frequent cause of errors. If the certificate is valid but still causing issues, I'd investigate potential configuration problems on the web server (e.g., Apache, Nginx). This includes ensuring the correct certificate and private key files are being referenced and that SSL/TLS protocols and cipher suites are configured securely and compatibly. I would also check for any recent changes to the server or network infrastructure that might have impacted SSL. This could include firewall rules, load balancer configurations, or DNS changes that might be interfering with the correct SSL handshake. If the certificate needs renewal or has been recently redeployed, I'd ensure that the process was handled with proper secret management, verifying the private key is secure and that the new certificate was deployed to all relevant servers and load balancers without interruption or misconfiguration. Once the immediate issue is resolved, I would implement robust monitoring to detect certificate expiration well in advance and ensure automated renewal processes are in place. Proactive checks of certificate validity and chain integrity will prevent future occurrences.

Expired SSL Certificate

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