curl - Debugging SSL Handshake -

how debug ssl handshake, preferably curl?

i troubleshoot per directory authentication client certificate. specially find out acceptable client certificates server send.

thanks in advance

i have used command troubleshoot client certificate negotiation:

openssl s_client -connect www.test.com:443 -prexit 

the output contain "acceptable client certificate ca names" , list of ca certificates server, or possibly "no client certificate ca names sent", if server doesn't require client certificates.