OpenSSL CheatSheet

openssl s_client -showcerts -connect www.domain.com:443

openssl x509 -in server.crt -text

openssl x509 -noout -modulus -in server.crt
openssl rsa -noout -modulus -in server.key

openssl x509 -noout -enddate -in server.crt | sed -e 's#notAfter=##'

openssl x509 -noout -checkhost $(hostname) -in /data/config/ssl/server.crt