paypal invalid ipn

[eluser]Unknown[/eluser]
Hi sph. could you help me please....??

i have a code for an IPN listener, and im working with sandbox. The response is always INVALID and I've tried diferrent things to prove that, thats the only problem....

Code:

<?php

// PHP 4.1
// read the post from PayPal system and add 'cmd'
  include('codigo.php');
  include('declararobjeto.php');
  $obj=declarar();
  $objinsertar=declarar();
$req = 'cmd=_notify-validate';
$objtexto=declarar();
$idx=0;
$linea="La hora es: ".horaactual();
$objtexto->ejecutar("INSERT into texto values('$idx','$linea')");

foreach ($_POST as $key => $value)
{
$value = urlencode(stripslashes($value));
$req .= "&$key=$value";
//  $req .= '&'.http_build_query($_POST);
}
$lin="Lo que recibo en req = ".$req;
  $objtexto->ejecutar("INSERT into texto values('$idx','$lin')");
// post back to PayPal system to validate
$header .= "POST /cgi-bin/webscr HTTP/1.0\r\n";
$header .= "Content-Type: application/x-www-form-urlencoded\r\n";
$header .= "Content-Length: " . strlen($req) . "\r\n\r\n";
//$fp = fsockopen ('ssl://www.sandbox.paypal.com', 443, $errno, $errstr, 30);
$fp = fsockopen ('ssl://ipnpb.paypal.com', 443, $errno, $errstr, 30);
//$cnx=mysql_connect("mysql1.000webhost.com","a6513996_doctorm","lumanbdluman000") or die(mysql_error());
//$cnx=mysql_connect("localhost","marc1ae_doctorm","lumanbdluman000") or die(mysql_error());
// assign posted variables to local variables
$item_name = $_POST['item_name'];
$item_number = $_POST['item_number'];
$payment_status = $_POST['payment_status'];
$payment_amount = $_POST['mc_gross'];
$payment_currency = $_POST['mc_currency'];
$txn_id = $_POST['txn_id'];
$receiver_email = $_POST['receiver_email'];
$payer_email = $_POST['payer_email'];
$user_id=mysql_real_escape_string((int)$_POST['custom']);
$user_id=$_POST['custom'];
/*
//----------------------------------------------------------
$lin="ITEMNAME = ".$item_name." , ";
$lin.="ITEMNUMBER = ".$item_number." , ";
$lin.="PAYMENTSTATUS = ".$payment_status." , ";
$lin.="PAYMENTAMOUNT = ".$payment_amount." , ";
$lin.="PAYMENTCURRECY = ".$payment_currency." , ";
$lin.="TXNID = ".$txn_id." , ";
$lin.="RECEIVEREMAIL = ".$receiver_email." , ";
$lin.="PAYEREMAIL = ".$payer_email." , ";
$lin.="USERID = ".$user_id." , ";
$objtexto->ejecutar("INSERT into texto values('$idx','$lin')");
//----------------------------------------------------------
*/

//mysql_close($cnx);
if (!$fp)
{
// HTTP ERROR
$lin="ERROR FP";
$objtexto->ejecutar("INSERT into texto values('$idx','$lin')");
}
else
{  
  $lin="Lo que le envio a FP = ".$header.$req;
  $objtexto->ejecutar("INSERT into texto values('$idx','$lin')");
  fputs ($fp, $header . $req);  
  
  while (!feof($fp))
  {  
$res = fgets ($fp, 1024);   //ESTA ES LA ORIGINAL
//$res=stream_get_contents($fp, 1024);
$lin=$res;
    $objtexto->ejecutar("INSERT into texto values('$idx','$lin')");


if (strcmp ($res, "VERIFIED") == 0)
{
    // check the payment_status is Completed
    if($payment_status=="Completed")
    { // check that txn_id has not been previously processed
      $obj->ejecutar("SELECT * from log where txn_id='$txn_id'");
   if($fobj=$obj->obtfila())
   {
    //si entra aqui es porque esa transaccion ya fue hecha anteriormente. debemos evitar duplicaciones.
   }
   else
   { // check that receiver_email is your Primary PayPal email
     if(($receiver_email=="[email protected]")||($receiver_email=="[email protected]")||($receiver_email=="[email protected]"))
     {
        if(($payment_amount=="8.99")&&($payment_currency=="USD"))
     {
        //ahora inserto el txn_id en la base de datos
     $idx=0;
       $objinsertar->ejecutar("INSERT into log values('$idx','$txn_id','$payer_email')");
     //ahora actualizo premium a 1
     $objinsertar->ejecutar("UPDATE users set premium='1' where user_id='$user_id'");
    
     }
     }
   }
    }


// check that payment_amount/payment_currency are correct
// process payment
    }
    else
{
   if (strcmp ($res, "INVALID") == 0)
   {
    // log for manual investigation
   }
}
}
fclose ($fp);
}

?>

when I was debugging my code i found this at $res....
HTTP/1.1 200 OK
Date: Mon, 03 Jun 2013 19:36:31 GMT
Server: Apache
X-Frame-Options: SAMEORIGIN
Set-Cookie: cwrClyrK4LoCV1fydGbAxiNL6iG=ZlLtTHhoH2...
Set-Cookie: cookie_check=yes; expires=Thu, 01-Jun-...
Set-Cookie: navcmd=_notify-validate; domain=.paypa...
Set-Cookie: navlns=0.0; expires=Sun, 29-May-2033 1...
Set-Cookie: Apache=10.74.8.69.1370288191671154; pa...
Vary: Accept-Encoding
Strict-Transport-Security: max-age=14400
Connection: close
Content-Type: text/html; charset=UTF-8

INVALID