If you want to connect to a server which requires that you identify yourself with a certificate, use following code. Your certificate and servers certificate are signed by an authority whose certificate is in ca.ctr.
<?php
curl_setopt($ch, CURLOPT_VERBOSE, '1');
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, '2');
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, '1');
curl_setopt($ch, CURLOPT_CAINFO, getcwd().'/cert/ca.crt');
curl_setopt($ch, CURLOPT_SSLCERT, getcwd().'/cert/mycert.pem');
curl_setopt($ch, CURLOPT_SSLCERTPASSWD, 'password');
?>
If your original certificate is in .pfx format, you have to convert it to .pem using following commands
# openssl pkcs12 -in mycert.pfx -out mycert.key
# openssl rsa -in mycert.key -out mycert.pem
# openssl x509 -in mycert.key >> mycert.pem
