testssl
Check SSL/TLS protocols and ciphers supported by a server. tldr-pages
On several platforms
Several platforms
Test a server (run every check) on port 443
testssl example.comIdentifyTest a different port
testssl example.com:465IdentifyOnly check available protocols
testssl --protocols example.comIdentifyOnly check vulnerabilities
testssl --vulnerable example.comIdentifyOnly check HTTP security headers
testssl --headers example.comIdentifyTest other STARTTLS enabled protocols
testssl --starttls ftp example.com:portIdentify