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