Hi Mikael, The server should send the subject in a header which you can get and maybe build a check on.
e.g. the HEAD command (libwww-perl package) $ /usr/bin/HEAD -s https://google.com/ | grep Client-SSL-Cert-Subject Client-SSL-Cert-Subject: /CN=www.google.com or just straight perl: $ perl -MLWP::UserAgent -le'print foreach LWP::UserAgent->new->get("https://atlassian.com")->headers->{"client-ssl-cert-subject"}' /C=AU/ST=New South Wales/L=Sydney/O=Atlassian Pty Ltd/CN=*.atlassian.com If the date is in YYYY-MM-DD format you could grab it, convert it to an epoch time and calculate the seconds left with: $ perl -MTime::Local -MLWP::UserAgent -le'LWP::UserAgent->new->get("https://your.vendor.com")->headers->{"client-ssl-cert-subject"} =~ /(\d{4})\-(\d\d)\-(\d\d)/ and print timelocal(0,0,0,$2,$1,$0) - time' cheers, Woody From: "Mikael Janeld" <mikael.jan...@tietoevry.com> To: "help" <help@monitoring-plugins.org> Sent: Wednesday, 3 November, 2021 8:00:03 PM Subject: Check date in Subject/OU in a Certificate. Hi, We have a vendor/application that stamps the expire date for a license in the Subject/OU field in a certificate and I am trying to found a way that we can use OP5 to monitor that. I have checked the “check_https_certificate” but it only checks when the certificates expires and in the application certificate the certificate expire date and the license expire date are different. I hope there is a way to solve this, either with “check_https_certificate” check or if we can use another check that can do this or maybe create a new check for this, can you help me with that or point me to a way that I can solve it? Med vänlig hälsning / Best regards, Mikael Janeld , VMware & Windows Specialist TietoEVRY, Financial Services - Card Acquiring email [ mailto:mikael.jan...@tietoevry.com | mikael.jan...@tietoevry.com ] , mobile +46 (0)73 236 5240 Ekensbergsvägen 113, Solna Tieto and EVRY are joining forces. [ http://www.tietoevry.com/ | www.tietoevry.com ] [ https://twitter.com/tietoevry | Twitter ] | [ https://www.facebook.com/tietoevry/ | Facebook ] | [ https://www.linkedin.com/company/tietoevry/ | LinkedIn ] Please note: The information contained in this message may be legally privileged, confidential and protected from disclosure. If you received this in error, please notify the sender immediately and delete the message from your computer. Thank you.