Get information about a certificate in Keychain Access on Mac
Use Keychain Access to view the information contained in a certificate.
Go to the Keychain Access app
on your Mac.To open Keychain Access, search for it in Spotlight, then press Return.
Select a keychain, then click either the My Certificates category or the Certificates category to see the certificates in that keychain.
Select the certificate you want to view, then click
in the toolbar. You can also double-click the certificate you want to view.