Checking what is actually being served.
HOW TO VIEW IT
Click the padlock in the address bar, then look for a connection or certificate option. The exact path differs between browsers but every one allows it.
WHAT TO READ
- Issued to: the hostnames covered. Look at the subject alternative names, which is the full list rather than just the primary name.
- Issued by: the certificate authority, and whether the chain shown reaches a trusted root.
- Validity period: the dates. If today is outside them, that is your problem.
The certification path, showing your certificate, the intermediate, and the root.
WHAT THIS TELLS YOU
Whether the certificate covers the name you are visiting Whether it has expired Whether the full chain is present Which authority issued it, which confirms whether AutoSSL or a purchased certificate is in use
WHEN TO DO THIS
Before opening a ticket about a certificate problem. The certificate itself usually contains the answer, and including what it says makes any ticket far faster to resolve.
