Hi @ManjunathN
There are multiple ways to monitor certificates. I would say, write a custom application that leverages openssl library and send the interested events from that application to Splunk using HEC. In addition, i would also recommend building an inventory of certificates which enlists the systems or applications its used within your organization. This can be later on referenced for impact assessment and you can even correlate to application failures/ events corroborated by the certificate. Also, write alerts for certificates that's about to expire in X days so that your operational/SRE team can liaise and generate new ones within a stipulated period.
There's a sample app you can use for checking certificate expiry from Splunkbase
https://splunkbase.splunk.com/app/3172
~ If the reply helps, a karma upvote would be appreciated.
