А теперь внимание, правильный ответ:
$add = http_build_query($params, NULL, '&');
$graph_url= "https://graph.facebook.com".$request.'?'.$add;
$appsecret_proof= hash_hmac('sha256', $access_token, $client_secret);
$postData = '';
$postData = "&appsecret_proof=" .$appsecret_proof;
$postData .= "&access_token=".$access_token;
$ch = curl_init($graph_url.$postData);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_TIMEOUT, 60);
curl_setopt($ch, CURLOPT_VERBOSE, true);
$output = curl_exec($ch);
curl_close($ch);
return json_decode($output);
