REGISTER WITH PAYPAL TUTORIAL (2/3): A Real Register with PayPal Project

CREATE TABLE IF NOT EXISTS `payment` (
`payId` int(11) NOT NULL AUTO_INCREMENT,
`timestamp` bigint(20) DEFAULT NULL,
`paid` float DEFAULT NULL COMMENT 'user paid amount returned by paypal',
`bankFee` float DEFAULT NULL,
`currency` varchar(4) DEFAULT NULL,
`txnId` varchar(32) DEFAULT NULL COMMENT 'Transaction ID: specify single unique transaction from paypal. if this field is NOT NULL, means this payment has been process already. So if IPN returns to PHP, we can refuse to update our database.',
`status` varchar(16) DEFAULT NULL,
`uid` int(11) DEFAULT NULL COMMENT 'FK to users PK',
PRIMARY KEY (`payId`),
KEY `uid` (`uid`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
CREATE TABLE IF NOT EXISTS `temp_register` (
`tRegId` int(11) NOT NULL AUTO_INCREMENT,
`fullName` varchar(255) DEFAULT NULL,
`uAcc` varchar(255) DEFAULT NULL,
`uPwd` varchar(32) DEFAULT NULL,
PRIMARY KEY (`tRegId`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 COMMENT='prevent unpaid user take uAcc(UNIQUE) in our users table' AUTO_INCREMENT=1 ;
CREATE TABLE IF NOT EXISTS `users` (
`uid` int(11) NOT NULL AUTO_INCREMENT,
`fullName` varchar(255) DEFAULT NULL,
`uAcc` varchar(255) NOT NULL,
`uPwd` varchar(32) NOT NULL,
`token` varchar(32) DEFAULT NULL,
`verified` tinyint(1) NOT NULL DEFAULT '0',
`priviledge` enum('delegate','admin','developer') NOT NULL DEFAULT 'delegate',
PRIMARY KEY (`uid`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
ALTER TABLE `payment`
ADD CONSTRAINT `payment_ibfk_1` FOREIGN KEY (`uid`) REFERENCES `users` (`uid`);

/**
* PAYPAL: PDT HANDLER:
* ====================
* called by PayPal, send tokens back
* get payment details and payment result
* @return $ret array contains result true/false, and user account or error message
*/
private function _PDT()
{
// some indexes can not be missing:
$ruler = array(
'tx', // token from paypal
);
if(count(array_diff($ruler, array_keys($_GET))))
{
return array('result' => false, 'error' => 'Index missing ... ', 'index' => $_GET, 'missing' => array_diff($ruler, array_keys($_GET)));
}
// read the post from PayPal system and add 'cmd'
$req = 'cmd=_notify-synch';
// get token and prepare request url (send back to paypal)
$tx_token = $_GET['tx'];$auth_token = "_PJaHiwRfwMmWzW-9nuPuSguYxC-1d9KpxaasaNANtIvyOcmqY6jXNkRmxW";
// $auth_token = "OxDenzKmrWPyEXU0YzIg2zs-VAe7ufCADyjbfxF_RpREL4rLEslZrSa21R4";
$req .= "&tx=$tx_token&at=$auth_token";
// post back to PayPal system to validate
$header = "POST /cgi-bin/webscr HTTP/1.0rn";
$header .= "Host: www.sandbox.paypal.comrn";
// $header .= "Host: www.paypal.comrn";
$header .= "Content-Type: application/x-www-form-urlencodedrn";
$header .= "Content-Length: " . strlen($req) . "rnrn";
$fp = fsockopen ('ssl://www.sandbox.paypal.com', 443, $errno, $errstr, 30); // open socket
// $fp = fsockopen ('ssl://www.paypal.com', 443, $errno, $errstr, 30); // open socket
if (!$fp)
{
// HTML FAIL
return array('result' => false, 'error' => 'HTTP error ... ');
}
else
{
fputs ($fp, $header . $req);
// read the body data
$res = '';
$headerdone = false;
while (!feof($fp))
{
$line = fgets ($fp, 1024);
if (strcmp($line, "rn") == 0)
{
$headerdone = true; // read the header
}
else if ($headerdone)
{
$res .= $line; // header has been read. now read the contents
}
}
// parse the data
$lines = explode("n", $res);
$keyarray = array();
if (strcmp ($lines[0], "SUCCESS") == 0)
{
for ($i=1; $i_validatePaypal($keyarray);
}
// log for manual investigation
else if (strcmp ($lines[0], "FAIL") == 0)
{
// skipped
return array('result' => false, 'error' => 'Transaction failed ... ');
}
}
fclose ($fp);
return $ret;
}

/**
* PAYPAL: IPN HANDLER:
* ====================
* called by PayPal, send POSTed payment data back (handshake)
* get payment result
* return: payment VERIFIED: array('result' => true/false, and other user details)
* payment INVALID: false // no further process (see handler in Register Module)
* TODO: return true if success, then send email to buyers
*/
private function _IPN()
{
// get IPN data
$postData = $_POST;// read the post from PayPal system and add 'cmd'
$req = 'cmd=' . urlencode('_notify-validate');
foreach ($postData as $key => $value) {
$value = urlencode(stripslashes($value));
$req .= "&$key=$value";
}
// CURL: copy from paypal sample code
$url= 'https://www.sandbox.paypal.com/cgi-bin/webscr';
// $url= 'https://www.paypal.com/cgi-bin/webscr';
$curl_result=$curl_err='';
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $req);
curl_setopt($ch, CURLOPT_HTTPHEADER, array("Content-Type: application/x-www-form-urlencoded", "Content-Length: " . strlen($req)));
curl_setopt($ch, CURLOPT_HEADER , array('Host: www.sandbox.paypal.com'));
// curl_setopt($ch, CURLOPT_HEADER , array('Host: www.paypal.com'));
curl_setopt($ch, CURLOPT_VERBOSE, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($ch, CURLOPT_TIMEOUT, 30);
$res = @curl_exec($ch);
$curl_err = curl_error($ch);
curl_close($ch);
$keyarray = $postData;
if (strcmp (substr($res, '-8'), "VERIFIED") == 0)
{
// validate paypal information
return $this->_validatePaypal($keyarray);
}
elseif (strcmp (substr($res, '-7'), "INVALID") == 0)
{
// log for manual investigation
return false;
}
// return $ret; // Do not need to return, because IPN runs in background
}