Originariamente inviato da vnt54
Quale codice?
ops questo... a grandi linee è quello predefinito che si trova nel facebook app,
codice:
<?php
define('FACEBOOK_APP_ID', '564646346363535');
define('FACEBOOK_SECRET', '2555554e352c88225555550a');

function parse_signed_request($signed_request, $secret) {
  list($encoded_sig, $payload) = explode('.', $signed_request, 2); 

  // decode the data
  $sig = base64_url_decode($encoded_sig);
  $data = json_decode(base64_url_decode($payload), true);

  if (strtoupper($data['algorithm']) !== 'HMAC-SHA256') {
    error_log('Unknown algorithm. Expected HMAC-SHA256');
    return null;
  }

  // check sig
  $expected_sig = hash_hmac('sha256', $payload, $secret, $raw = true);
  if ($sig !== $expected_sig) {
    error_log('Bad Signed JSON signature!');
    return null;
  }

  return $data;
}

function base64_url_decode($input) {
    return base64_decode(strtr($input, '-_', '+/'));
}

if ($_REQUEST) {
  
  $response = parse_signed_request($_REQUEST['signed_request'], 
                                   FACEBOOK_SECRET);
  echo '<pre> Benvenuto '; print_r ($response["registration"]["name"]); echo '</pre>

'; 
} else {?>
  <iframe src="https://www.facebook.com/plugins/registration?
             client_id=132025016958704&
           redirect_uri=http%3A%2F%2Fspazifluidi.altervista.org%2Fblog%2Fblog%2F& 
             fields=name,email"
        scrolling="auto"
        frameborder="yes"
        style="border:none"
        allowTransparency="true"
        width="90%"
        height="330">

</iframe><?
}
?>