How to debug SSL handshake using cURL?

client-certificates, curl, ssl

Solution

I have used this command to troubleshoot client certificate negotiation:

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

The output will probably contain "Acceptable client certificate CA names" and a list of CA certificates from the server, or possibly "No client certificate CA names sent", if the server doesn't always require client certificates.

Problem

I would like to troubleshoot per directory authentication with client certificate. I would specially like to find out which acceptable client certificates does server send. How do I debug SSL handshake, preferably with cURL?

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