In this post we will know about how to find date of expiry and issue of SSL certificate with command line. As a system administrator it is good to know how can we get the ssl certificate information with command line. It helps you to make script and run from terminal/cron job etc.
We have created nagios plugin with the help of this command.Here in this post, we are sharing with our readers.
In your system openssl package should be installed.
In CentOS/RHEL
yum install openssl
In Debian/Ubuntu
sudo apt-get install openssl
NOTE: Replace google.com with the domain name of your choice. And the certificate should be used in Website.
Date of issue of SSL Certificate
echo "QUIT" | openssl s_client -connect google.com:443 2>/dev/null | openssl x509 -noout -startdate 2>/dev/null
Date of expiration of SSL Certificate
echo "QUIT" | openssl s_client -connect google.com:443 2>/dev/null | openssl x509 -noout -enddate 2>/dev/null
Given below is the reference from our system
sharad@linuxworld:~$ echo "QUIT" | openssl s_client -connect google.com:443 2>/dev/null | openssl x509 -noout -enddate 2>/dev/null notAfter=Mar 3 00:00:00 2015 GMT sharad@linuxworld:~$ sharad@linuxworld:~$ echo "QUIT" | openssl s_client -connect google.com:443 2>/dev/null | openssl x509 -noout -startdate 2>/dev/null notBefore=Dec 3 11:52:24 2014 GMT sharad@linuxworld:~$
