Command prompt to check TLS version required by a host

LakeMichigan picture LakeMichigan · Nov 11, 2016 · Viewed 54.8k times · Source

Is there a command to check the TLS version reuired by a host site. Right now, the only way I know to check is by adjusting the max TLS version of my browser and checking if I can still access the site. However, I suspect there is a more sophisticated way to do this.

Answer

root picture root · Nov 12, 2016

you can check using following commands

for tls 1.2

openssl s_client -connect www.google.com:443 -tls1_2

for tls 1.1

openssl s_client -connect www.google.com:443 -tls1_1

for tls 1

openssl s_client -connect www.google.com:443 -tls1

If you get the certificate chain and the handshake then the tls version is supported. If you don't see the certificate chain, and something similar to "handshake error" then its not.