The reason for this error is that Curl performs SSL certificate verification by default, using a “bundle” of Certificate Authority (CA) public keys (CA certs) and the CA that issued the certificated for the server is not in the default bundle.
- Specify an alternate file using the CURLOPT_CAINFO option. The CA for locklizard-license2.co.uk is GoDaddy.com, Inc.
- Specify 1 rather than TRUE for the VERIFYPEER option. 1=TRUE and 0=FALSE. Example: curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1);
- Uncomment the line curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE); This is not an ideal solution however because you don’t know who the site is that you are now talking to (could be a spoof site).
curl_setopt($ch, CURLOPT_CAINFO, /path to cabundle);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1); // uncomment this line if you get no gateway response. ###
Some useful sites for information are: