How crub access Self-Signed Certificate website?

My Site’s Certificate is Self-Signed.
(followed Generating an SSL Certificate with Apache+mod_ssl the instruction)

if I curl https://mysite.com/ will get the error response.
according to http://curl.haxx.se/docs/sslcerts.html
the followed commands are able to to access my website by curl

openssl s_client -connect mysite.com:443 |tee logfile
curl --cacert logfile https://mysite.com/

when I want to use Curb to access my site,
I try to search the Curb manual, I don’t know after getting site’s CA
certificate how Curb import it to perform like curl.

Thank you.