How Often Should I Check My SSL/TLS Configuration?

The Importance of Regular SSL/TLS Monitoring

SSL/TLS configuration isn't a "set and forget" system. Certificates expire, configurations change, vulnerabilities emerge, and new versions of TLS become standard. Regular monitoring ensures your HTTPS security remains strong and you catch problems before they affect your users.

Recommended Monitoring Frequency

Certificate Expiration: Monthly Check

Calendar your certificate's expiration date (minus 30 days) as a monthly reminder. Most certificate authorities send expiration notices, but these often end up in spam or forwarding them. Don't rely solely on CA notifications.

Certificate expires: January 15, 2025
Reminder: December 15, 2024

Set multiple reminders at 30, 14, and 7 days before expiration to provide adequate notice for renewal.

Configuration Security: Quarterly Review

Review your SSL/TLS configuration every three months:

• Cipher suite support
• TLS version support
• Security header implementation
• Certificate chain completeness

Use SSL Checker quarterly to verify configuration hasn't drifted from best practices.

Emergency Checks: When Changes Occur

Immediately check SSL configuration when:

• You update server software (nginx, Apache, etc.)
• You change certificate or key files
• You update TLS libraries (OpenSSL, etc.)
• You modify SSL/TLS configuration files
• You hear about new vulnerabilities

Automated Continuous Monitoring

Rather than relying on manual checks, implement automated monitoring:

Certificate Monitoring Services:

• Entrust Certificate Monitoring
• Digicert Certificate Insights
• Sectigo Certificate Monitor
• Custom monitoring using APIs

These services provide:

• Real-time expiration alerts
• Certificate change detection
• Configuration anomaly detection
• Email notifications before expiration

Configuration Monitoring:

Use a cron job or scheduled task to run checks:

#!/bin/bash
# Daily SSL check with email alert on failure

DOMAIN="example.com"
EXPIRY_DAYS=30

EXPIRY_EPOCH=$(echo | openssl s_client -servername $DOMAIN -connect $DOMAIN:443 2>/dev/null | \
  openssl x509 -noout -enddate | cut -d= -f2 | date -f - +%s)

CURRENT_EPOCH=$(date +%s)
DAYS_LEFT=$(( ($EXPIRY_EPOCH - $CURRENT_EPOCH) / 86400 ))

if [ $DAYS_LEFT -lt $EXPIRY_DAYS ]; then
  echo "Certificate expires in $DAYS_LEFT days" | mail -s "SSL Certificate Alert" [email protected]
fi

Run this daily to catch certificate expiration with advance notice.

Automated TLS Configuration Testing:

Services like Google's SSL Labs API, Mozilla Observatory API, or self-hosted tools can test configuration automatically and alert on changes:

#!/bin/bash
# Weekly SSL configuration check

DOMAIN="example.com"
BASELINE="previous-test-results.json"

# Run test and save results
curl -s "https://api.ssllabs.com/api/v3/analyze?host=$DOMAIN&publish=off&all=done" > current-results.json

# Compare with baseline
if ! diff $BASELINE current-results.json > /dev/null; then
  echo "SSL configuration changed!" | mail -s "SSL Config Change Alert" [email protected]
  cp current-results.json $BASELINE
fi

What to Check During Regular Monitoring

Certificate Information:

• Certificate is valid (not expired)
• Certificate is still valid until at least 30 days from now
• Certificate common name matches your domain
• All expected Subject Alternative Names are present

TLS Configuration:

• TLS 1.2 and 1.3 are supported
• TLS 1.0 and 1.1 are disabled
• All cipher suites use strong encryption (AES-GCM, ChaCha20)
• Perfect Forward Secrecy (ECDHE) is in use
• Weak ciphers (RC4, DES, MD5) are disabled

Certificate Chain:

• Complete chain is presented (leaf + intermediate + root)
• Intermediate certificate is not expired
• All chain certificates are valid

Security Headers:

• Strict-Transport-Security (HSTS) is implemented
• HSTS max-age is appropriate (31536000)
• HSTS includes subdomains (if needed)
• X-Frame-Options is set
• X-Content-Type-Options: nosniff is present

Known Vulnerabilities:

• No recent vulnerabilities affecting your TLS implementation
• OpenSSL and TLS libraries are up to date

Using SSL Checker for Monitoring

Make SSL Checker part of your regular process:

Monthly:

1. Visit SSL Checker
2. Enter your domain
3. Check certificate expiration date
4. Note in calendar: 30 days before expiration

Quarterly:

1. Run full SSL Checker analysis
2. Compare results with previous quarter
3. Note any configuration changes
4. Address any new warnings

After Changes:

1. Make configuration changes
2. Immediately run SSL Checker
3. Verify expected results
4. Alert if unexpected changes

Certificate Renewal Timeline

Plan certificate renewal well in advance:

90 Days Before Expiration:

• Review certificate renewal process
• Decide on new certificate type/length
• Budget for renewal (if required)

60 Days Before Expiration:

• Submit renewal request to CA
• Update any DNS/validation records if needed
• Plan maintenance window if necessary

30 Days Before Expiration:

• Receive renewed certificate
• Test in staging environment
• Deploy to production
• Verify with SSL Checker

14 Days Before Expiration:

• Ensure renewal is in production
• Verify all domain endpoints are correct
• Set reminder for next renewal

Retiring your old certificate 7-14 days after deployment ensures all client caches have been updated.

Vulnerability Monitoring

Stay informed about SSL/TLS vulnerabilities:

Subscribe to Vulnerability Notifications:

• OpenSSL security announcements
• Apache/nginx security mailing lists
• Your certificate authority's security bulletins
• CISA alerts (US government alerts)

Monitor for Specific Vulnerabilities:

• BEAST, CRIME, POODLE (older attacks, but good to know they're mitigated)
• Heartbleed, Logjam, DROWN (specific vulnerability names to monitor)
• Critical CVEs affecting your TLS implementation

When a vulnerability is announced:

1. Check if your system is affected
2. Test with SSL Checker for visible impact
3. Patch your system if affected
4. Re-test to verify fix

Monitoring Checklist Template

Create a monitoring checklist for your team:

## Monthly SSL Monitoring Checklist

Date: ___________
Checked by: ___________

### Certificate Status
- [ ] Certificate not expired
- [ ] Days until expiration: ___
- [ ] Renewal needed? (> 30 days): Yes / No

### TLS Configuration
- [ ] TLS 1.2+ supported
- [ ] TLS 1.0/1.1 disabled
- [ ] ECDHE ciphers in use
- [ ] Weak ciphers disabled

### Security Headers
- [ ] HSTS header present
- [ ] HSTS max-age appropriate
- [ ] X-Frame-Options set
- [ ] Security headers complete

### Issues Found
_____________________
_____________________

### Actions Required
_____________________
_____________________

### Follow-up Date
_____________________

Automating Monitoring in CI/CD

Integrate SSL checking into your deployment pipeline:

# .github/workflows/ssl-check.yml
name: SSL Configuration Check

on:
  schedule:
    - cron: '0 0 * * 0'  # Weekly
  workflow_dispatch:

jobs:
  ssl-check:
    runs-on: ubuntu-latest
    steps:
      - name: Check SSL Configuration
        run: |
          DOMAIN="example.com"

          # Test TLS versions
          openssl s_client -connect $DOMAIN:443 -tls1_2 < /dev/null
          openssl s_client -connect $DOMAIN:443 -tls1_3 < /dev/null

          # Check certificate validity
          echo | openssl s_client -servername $DOMAIN -connect $DOMAIN:443 2>/dev/null | \
            openssl x509 -noout -dates

          # Check headers
          curl -I https://$DOMAIN | grep -i "Strict-Transport-Security"

Third-Party Monitoring Services

Consider professional monitoring services:

Uptime/Security Monitoring:

• Pingdom (SSL certificate monitoring)
• Statuspage.io (includes SSL checks)
• UptimeRobot (free SSL monitoring)

Dedicated SSL Monitoring:

• Entrust Certificate Monitoring
• Digicert CertCentral
• Sectigo Certificate Management

Vulnerability Scanning:

• Qualys SSL Labs (free and paid)
• Nessus (requires installation)
• Rapid7 (continuous monitoring)

These services provide:

• Scheduled testing and alerts
• Historical trending
• Vulnerability databases
• Integration with incident management

Best Practices for Continuous Monitoring

1. Automate expiration alerts - Set multiple reminders before expiration
2. Monitor configuration changes - Detect unexpected modifications
3. Track vulnerability disclosures - Stay informed about TLS vulnerabilities
4. Regular manual checks - Use SSL Checker monthly to verify automated systems
5. Maintain audit logs - Document all certificate and configuration changes
6. Test after updates - Check SSL configuration immediately after any changes
7. Document procedures - Have a clear process for renewal and updates
8. Distribute responsibility - Don't rely on one person for monitoring
9. Set up alerts - Slack, email, or PagerDuty notifications
10. Plan ahead - Certificate renewal before expiration, not after

Response Plan for Issues

When monitoring reveals issues:

Certificate Expiration (<30 days):

1. Immediately request renewal from CA
2. Expedite deployment process if needed
3. Alert team to prepare for update
4. Schedule maintenance window if necessary

Configuration Issues:

1. Identify the change that caused the issue
2. Test in staging first
3. Deploy fix to production
4. Re-test with SSL Checker

Vulnerability Disclosure:

1. Assess if your system is affected
2. Determine severity level
3. Plan patch timeline
4. Apply patches and re-test

Conclusion: Continuous Monitoring Is Essential

SSL/TLS security isn't a one-time implementation—it requires continuous monitoring and maintenance. Certificates expire, configurations drift, and new vulnerabilities emerge regularly. A combination of automated monitoring (for expiration and changes) and regular manual checks (using SSL Checker quarterly) creates a robust monitoring strategy. Most certificate-related incidents are preventable through proper monitoring and planning. Invest in monitoring infrastructure now to avoid emergency situations later.