Hi, >From 1st Sep, any cert with a validity of over 398 days will be rejected by Opera. https://www.theregister.co.uk/2020/02/20/apple_shorter_cert_lifetime/ I expect other browsers to follow suit.
I suggest adding an option to check_http to set the maximum validity time of the certificate. My C is rather rusty but I'd be happy to try and hack something together if you think this check will be useful (and no-one on the project wants to code it!). Kind regards, Dave.