check SSL certificate expiration

Usage: ./check_expiration www.verisign.com

[-] Certificate for www.verisign.com has not expired yet: May 8 23:59:59 2009 GMT

 

#!/bin/bash 

dates=$(echo "GET /" |openssl s_client -connect "$1:443" 2> /dev/null |openssl x509 -noout -dates) 

# For STARTTLS over e.g. smtp, replace the offending field by: 

# openssl s_client -connect "$1:25" -starttls smtp if [ -z "$dates" ]; then    

 echo "[!] Invalid IP, not SSL or no cert found"     

exit 2 

fi 

not_after=$(echo $dates|cut -d '=' -f 3) 

now_epoch=$(date +%s) 

not_after_epoch=$(date +%s -d "$not_after") 

if [ $now_epoch -gt $not_after_epoch ]; then    

echo "[!] Certificate for $1 has expired: $not_after"     

exit 1 

else     

echo "[-] Certificate 

for $1 has not expired yet: $not_after" fi

After Completing the script change the permission of the script

#chm0d +x check_expiration.bash