Paypal PDT Handling Script, slightly cleaned up

paypal_pdt

<?php

// PayPal PDT code
	
	// read the post from PayPal system and add 'cmd'
	$req = 'cmd=_notify-synch';
	
	$tx_token = $_GET['tx'];
	$auth_token = "YOUR TOKEN GOES HERE";
	$req .= "&tx=$tx_token&at=$auth_token";
	
	// 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 ('www.paypal.com', 80, $errno, $errstr, 30);
	// If possible, securely post back to paypal using HTTPS
	// Your PHP server will need to be SSL enabled
	// $fp = fsockopen ('ssl://www.paypal.com', 443, $errno, $errstr, 30);
	
	if (!$fp) {
		// HTTP ERROR
		echo("<h3>HTTP Error</h3>");
	} else {
		fputs ($fp, $header . $req);
		// read the body data 
		$res = '';
		$headerdone = false;
		while (!feof($fp)) {
			$line = fgets ($fp, 1024);
			if (strcmp($line, "\r\n") == 0) {
				// read the header
				$headerdone = true;
			} else if ($headerdone) {
				// header has been read. now read the contents
				$res .= $line;
			}
		}
	
		// parse the data
		$lines = explode("\n", $res);
		$keyarray = array();
		if (strcmp ($lines[0], "SUCCESS") == 0) {
			for ($i=1; $i<count($lines);$i++){
				list($key,$val) = explode("=", $lines[$i]);
				$keyarray[urldecode($key)] = urldecode($val);
			}
			// check the payment_status is Completed
			// check that txn_id has not been previously processed
			// check that receiver_email is your Primary PayPal email
			// check that payment_amount/payment_currency are correct
			// process payment
			$firstname = $keyarray['first_name'];
			$lastname = $keyarray['last_name'];
			$itemname = $keyarray['item_name'];
			$amount = $keyarray['payment_gross'];
			$item_id = $keyarray['item_number'];
			?>
	
			<h3>Payment Details</h3>
			<p>
				<strong>Name:</strong> <?= $firstname ?> <?= $lastname ?><br />
				<strong>Item:</strong> <?= $itemname ?><br />
				<strong>ID:</strong> <?= $item_id ?><br />				
				<strong>Amount:</strong> <?= $amount ?>
			</p>

			<?php
			
		} else if (strcmp ($lines[0], "FAIL") == 0) {
			echo("<h3>There was a problem parsing the data</h3>");
			// log for manual investigation
		}

	}

	fclose ($fp);
?>