SSL Analyzer

An SSL certificate analyzer reads the certificate presented by a TLS endpoint and turns its fields into an operational checklist. Useful fields include the subject, Subject Alternative Name entries, issuer, validity window, public-key algorithm, and fingerprint. The certificate is only one part of HTTPS: DNS routing, SNI, protocol negotiation, intermediate certificates, and the application listener must all agree for a client to trust the connection.

Analyze the public hostname, preserve the hostname during the connection, and compare the certificate's SAN list with every URL your application publishes. Check both expiry and the time remaining for renewal automation. If a service sits behind a load balancer or CDN, test each edge address when possible because a partial rollout can present different certificates. Never upload private keys; an analyzer should need only the public endpoint and certificate data.

A certificate can be valid, unexpired, and still wrong for the requested host. Wildcards cover only one label, and an IP address may return a default certificate when the client omits SNI. Checking SAN coverage and SNI behavior catches hostname mistakes that a simple expiry monitor misses. Record the fingerprint and edge address during an incident, then add a regression check for the exact certificate mismatch that was fixed.