http://www.perlmonks.org?node_id=1033506


in reply to Re: LWP UserAgent - Sending Client Certificate connect to remote host
in thread LWP UserAgent - Sending Client Certificate connect to remote host

From what I know an http authentication can not be done with a certificate. It is done with user credentials (username/passwords) protected by an encrypted communication (https).
No, HTTPS authentication can be done with a certificate. However I am not sure if LWP allows this. And yes SSL_ca_file is possible incorrect option. Documentation for this stuff should be somewhere here http://search.cpan.org/perldoc?IO%3A%3ASocket%3A%3ASSL