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πŸ“˜ Excessive Explanation

🧩 Technical Details

What this tool checks

  • Certificate chain validity and expiry horizon signals.
  • Issuer, SAN, and key metadata relevant for trust decisions.
  • ALPN negotiation evidence and HTTP/3 confirmed vs. advertised status.

How to read the output

  • Result Summary quickly shows whether certificate posture is safe.
  • Overview emphasizes expiry risk and protocol negotiation outcomes.
  • Technical Details is where chain and negotiation evidence should be reviewed.
  • Raw Output is suitable for certificate-ops escalation and audit records.

Common failure patterns

  1. Near-expiry certificates create immediate outage risk windows.
  2. SAN mismatch breaks trust for expected hostnames.
  3. Incomplete chain causes validation failure on strict clients.
  4. HTTP/3 advertised but not actually reachable via QUIC.

Remediation workflow

  1. Automate renewal and monitor expiry thresholds proactively.
  2. Ensure SAN list aligns with all production hostnames.
  3. Deploy full chain consistently across edge and origin termination points.
  4. Re-test ALPN and HTTP/3 after TLS/CDN changes.

Next steps

❓ Frequently asked questions

How early should certificate expiry be treated as critical?

Most teams treat under-30-day validity as high priority, with tighter thresholds for critical services.

Is HTTP/3 advertisement enough?

No. Confirmed connectivity is needed before treating HTTP/3 as operationally available.

Can chain issues affect only some users?

Yes. Client trust stores and validation strictness can differ by platform.

Should wildcard certs replace SAN planning?

Wildcard helps, but SAN coverage still must match actual host strategy.

What follows TLS validation in incident flow?

Check headers and application response behavior on the same target.