I am using an ec2 linux machine. How do I check the TLS / SSL version from the command line or browser?


You cannot do it without pausing the process (i.e. you can always attach a debugger such as gdb and try to work from that, but the process gets paused and it's whole hell of work anyway). The TLS version isn't saved anywhere else besides where the process puts it. It's not an OS thing.

If you started a tcpdump or tshark gathering packets before the connection was initiated, the TLS version will be visible in the second packet. TLS version is always transferred unencrypted.

  • Just wow! You know your stuff. – petey May 17 '18 at 18:10

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