Logging TLS versions for TTLS/EAP

Hi! To gather a deeper insight in what TLS versions are used by clients in our wireless network, I want to log what MAC address uses what TLS version (and maybe cipher algorithm, but that is secondary) during the PEAP or TTLS handshake. I guess a simple linelog would be sufficient for that task, but, I must confess, I am a bit lost on what attributes to use for the TLS version part, if there even *is* a way to log this information. I'd appreciate a little push in the right direction. Grüße, Sven.