PayPal notify_url无法通过strcmp验证

Question

I'm having some issues with my notify_url in PayPal. The handshake is fine, but the code to update my DB doesn't work. So to debug, I'm using the return.php url to output some data and try to debug and echo where the problem is.

Here is what I did so far to debug (on return.php)

$req = 'cmd=_notify-validate';
 foreach ($_POST as $key => $value) 
{
    $value = urlencode(stripslashes($value));
    $req .= "&$key=$value";
}

echo "<br>test REQ: ".$req."<br><br>";;

$header .= "POST /cgi-bin/webscr HTTP/1.0
";
$header .= "Content-Type: application/x-www-form-urlencoded
";
$header .= "Content-Length: " . strlen($req) . "

";


$fp = fsockopen ('ssl://www.sandbox.paypal.com', 443, $errno, $errstr, 30);

if (!$fp) 
{
    echo "FP NOT WORKIGN";
} 
else 
{
    echo "FP WORKIGN<br><br>";

    fputs ($fp, $header . $req);

    while (!feof($fp)) 
    {
        echo "whie: YES<br>";
        $res = fgets ($fp, 1024);
        if (strcmp ($res, "VERIFIED") == 0) 
        {
            echo "verified<br>";

            if($status == "Completed")
            {   
                echo "<br>####### completed<br>";
            }
        }
    }
}

My result is I get the echo of REQ, I get the echo of FP Working, I get echo "WHILE YES" 5 times, but I don't the echo of "VERIFIED". SO it seems the script doesn't get pass the if (strcmp ($res, "VERIFIED") == 0)

I'm stuck now, how can I fix this issue? Not sure what's wrong

This is the echo of my $req (if it helps to debug)

test: cmd=_notify-validate&mc_gross=1.00&protection_eligibility=Ineligible&payer_id=3EW5DFETD3E4L&tax=0.00&payment_date=15%3A35%3A43+Nov+14%2C+2016+PST&payment_status=Completed&charset=windows-1252&first_name=test&mc_fee=0.33¬ify_version=3.8&custom=1000%40%40Katia%40%40213+st-louis%40%40lemoyne%40%40quebec%40%40j4r+2l3%40%40Canada%40%401%40%40CAD%40%400%40%401.00&payer_status=verified&business=louisefrigon1-facilitator%40gmail.com&quantity=1&payer_email=louisefrigon1-buyer%40gmail.com&verify_sign=AFcWxV21C7fd0v3bYYYRCpSSRl31AchhgWj8TBE3e7K7SSx6jHwconuT&txn_id=6E11719159210262F&payment_type=instant&last_name=buyer&receiver_email=louisefrigon1-facilitator%40gmail.com&payment_fee=&receiver_id=LMCZ83V6LRE4S&txn_type=web_accept&item_name=Superfood+Powder&mc_currency=CAD&item_number=&residence_country=CA&test_ipn=1&handling_amount=0.00&transaction_subject=&payment_gross=&shipping=0.00&merchant_return_link=click+here&auth=A1CZ8ecFDP.O-dZHCSU6ouq8Gxn8qrDXHyoUX9qI-CEmFlvuS1Rq8FlqPmP8dCqlTffcxTJX84-huLEvRi5C.fA