56 Received HTTP code 403 from proxy after CONNECT?

Question

I am getting an "56 Received HTTP code 403 from proxy after CONNECT" Error while generating a lead to salesforce using cUrl from my web page. SSL certificate of the site is already expired.

UPDATED:

my code is as follows:

  curl_setopt($curl, CURLOPT_URL, $_url);
  curl_setopt($curl, CURLOPT_POST, count($field));
  curl_setopt($curl, CURLOPT_POSTFIELDS, $query_data);
  curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
  curl_setopt($curl, CURLOPT_HEADER, 1);
  curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, FALSE);
  curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, FALSE);
  curl_setopt($curl, CURLOPT_USERAGENT, "cusom module");

Answer 1

Add

AllowCONNECT port[-port] [port[-port]] ...

below ProxyRequests On in httpd_proxy.conf of apache proxy

eg:

ProxyRequests On
AllowCONNECT 443 563 5000

5000 is port of destination address.