"https://www.ssllabs.com" could scan your server and give results about the weakness of your server by the domain name of server
"https://testssl.sh/" testssl.sh is a free command line tool which checks a server's service on any port for the support of TLS/SSL ciphers, protocols as well as recent cryptographic flaws and more.
"https://wiki.mozilla.org/Security/Server_Side_TLS' is the TLS intoduction