I have several SSL certificates, and I would like to be notified, when a certificate has expired.
My idea is to create a cronjob, which executes a simple command every day.
I know that the
openssl command in Linux can be used to display the certificate info of remote server, i.e.:
openssl s_client -connect www.google.com:443
But I don't see the expiration date in this output. Also, I have to terminate this command with CTRL+c.
How can I check the expiration of a remote certificate from a script (preferably using
openssl) and do it in "batch mode" so that it runs automatically without user interaction?