Application Certificate Invalid (Additional Scenarios)
Issue Description
Application certificate is reported as invalid in various scenarios.
Additional Scenarios
Scenario 1: Certificate Chain Incomplete
Symptoms: Certificate validation fails
Cause: Missing intermediate certificates
Solution: Install complete certificate chain
Scenario 2: Certificate Revoked
Symptoms: Certificate shows as invalid
Cause: Certificate has been revoked by CA
Solution: Obtain new certificate
Scenario 3: Wrong Certificate Installed
Symptoms: Domain mismatch errors
Cause: Certificate for wrong domain installed
Solution: Install correct certificate
Scenario 4: Certificate Not Yet Valid
Cause: Certificate start date in future
Solution: Wait or obtain correctly dated certificate
Scenario 5: Self-Signed Certificate
Symptoms: Untrusted certificate error
Cause: Self-signed not in trust store
Solution: Use trusted CA or add to trust store
Investigation Steps
1.
openssl s_client -connect domain:443 -showcerts
2. **Verify Certificate Chain**
- Check all intermediates present
- Verify chain order
- Validate signatures
- Check expiration dates
3. **Test from Multiple Locations**
- Different monitoring nodes
- Different browsers
- Different networks
- Online SSL checkers
## Resolution by Scenario
### Incomplete Chain
- Download intermediate certificates
- Install in correct order
- Verify chain completeness
- Test validation
### Revoked Certificate
- Contact certificate provider
- Obtain new certificate
- Install immediately
- Set up monitoring
### Wrong Certificate
- Verify domain ownership
- Obtain correct certificate
- Install on correct server
- Verify installation
## Prevention
- Monitor certificate status
- Set up expiration alerts
- Use automated certificate management
- Regular certificate audits