OpenSSL

Show Certificate information

openssl s_client -showcerts -connect you-server.com:443 </dev/null

Show SHA1 Fingerprint of Certificate

openssl s_client -connect server:port < /dev/null 2>/dev/null | openssl x509 -fingerprint -noout -in /dev/stdin

Send a Certificate Status Request to the Server

If the server supports OCSP stapling, openssl will show the result in the response printed on stdout. Use the -status flag

openssl s_client -connect example.com:443 -status