check ssl certification info

check expiry date of a single ssl certificate

openssl x509 -enddate -subject -noout -in cert.pem

check expiry date of multiple ssl certificates

find -name cert.pem -exec openssl x509 -enddate -subject -noout -in {} \;

get creation and expiry from a ssl certificate

openssl x509 -startdate -enddate -subject -noout -in cert.pem

get all information from a ssl certificate

openssl x509 -text -noout -in cert.pem

test a ssl certificate

openssl s_client -connect www.paypal.com:443

openssl s_client paypal.com:443 2> /dev/null | openssl x509 -noout -dates

check all options about a ssl certificate

man x509