Functions to use curl make server side GET and POST requests with SSL and PHP. You can get CA bundle file in PEM format from: http://curl.haxx.se/docs/caextract.html.

gistfile1.php

function doPost($url, $parameters = array(), $headers = array()){

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $parameters);
    curl_setopt($ch, CURLOPT_CAINFO, realpath("../certs/cacert.pem"));
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, TRUE);
    curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    $result = curl_exec($ch);
    curl_close($ch);

    return $result;

}

function doGet($url, $parameters = array(), $headers = array()){

    if(sizeof($parameters) > 0){
        $url = $url . "?" . http_build_query($parameters);
    }

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
    curl_setopt($ch, CURLOPT_CAINFO, realpath("../certs/cacert.pem"));
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, TRUE);
    curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    $result = curl_exec($ch);
    curl_close($ch);

    return $result;

}