Please used post method instead of get method....
Try jsonp in your ajax since you are accessing cross domain with call back function.For more information about jsonp see the link:-
http://www.cypressnorth.com/blog/programming/cross-domain-ajax-request-with-json-response-for-iefirefoxchrome-safari-jquery/
http://json-p.org/
The most important thing you need is the server side page you are using for doing curl has to set some headers for allowing http to https connection. This are below....
header("Access-Control-Allow-Origin: your https url");
header("Access-Control-Allow-Methods: POST, GET");
header("Access-Control-Max-Age: 1728000");
header("Access-Control-Allow-Headers: Content-Type, Connection, Depth, User-Agent, X-File-Size, X-Requested-With, If-Modified-Since, X-File-Name, Cache-Control");
header("Connection: close");