PHP

<?php
/**
 * Notes:
 * - All lines with the suffix "// DEBUG" are for debugging purposes and
 *   can safely be removed from live code.
 * - Remember to set PAYFAST_SERVER to LIVE for production/live site
 */
// General defines
define( 'PAYFAST_SERVER', 'TEST' );
    // Whether to use "sandbox" test server or live server
define( 'USER_AGENT', 'Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)' );
    // User Agent for cURL
 
// Messages
    // Error
define( 'PF_ERR_AMOUNT_MISMATCH', 'Amount mismatch' );
define( 'PF_ERR_BAD_SOURCE_IP', 'Bad source IP address' );
define( 'PF_ERR_CONNECT_FAILED', 'Failed to connect to PayFast' );
define( 'PF_ERR_BAD_ACCESS', 'Bad access of page' );
define( 'PF_ERR_INVALID_SIGNATURE', 'Security signature mismatch' );
define( 'PF_ERR_CURL_ERROR', 'An error occurred executing cURL' );
define( 'PF_ERR_INVALID_DATA', 'The data received is invalid' );
define( 'PF_ERR_UKNOWN', 'Unkown error occurred' );
 
    // General
define( 'PF_MSG_OK', 'Payment was successful' );
define( 'PF_MSG_FAILED', 'Payment has failed' );
 
 
// Notify PayFast that information has been received
header( 'HTTP/1.0 200 OK' );
flush();
 
// Variable initialization
$pfError = false;
$pfErrMsg = '';
$filename = 'notify.txt'; // DEBUG
$output = ''; // DEBUG
$pfParamString = '';
$pfHost = ( PAYFAST_SERVER == 'LIVE' ) ?
	'www.payfast.co.za' : 'sandbox.payfast.co.za';
 
//// Dump the submitted variables and calculate security signature
if( !$pfError )
{
    $output = "Posted Variables:\n\n"; // DEBUG
 
    // Strip any slashes in data
    foreach( $_POST as $key => $val )
        $_POST[$key] = stripslashes( $val );
 
    foreach( $_POST as $key => $val )
    {
    	$output .= $key .'='. $val ."\r\n"; // DEBUG
 
        if( $key != 'signature' )
            $pfParamString .= $key .'='. urlencode( $val ) .'&';
    }
 
    $output .= "\n\n"; // DEBUG
 
    // Remove the last '&' from the parameter string
    $pfParamString = substr( $pfParamString, 0, -1 );
    $signature = md5( $pfParamString );
 
    $result = ( $_POST['signature'] == $signature );
 
    $output .= "Security Signature:\n\n"; // DEBUG
    $output .= "- posted     = ". $_POST['signature'] ."\n"; // DEBUG
    $output .= "- calculated = ". $signature ."\n"; // DEBUG
    $output .= "- result     = ". ( $result ? 'SUCCESS' : 'FAILURE' ) ."\n"; // DEBUG
}
 
//// Verify source IP
if( !$pfError )
{
    $validHosts = array(
        'www.payfast.co.za',
        'sandbox.payfast.co.za',
        'w1w.payfast.co.za',
        'w2w.payfast.co.za',
        );
 
    $validIps = array();
 
    foreach( $validHosts as $pfHostname )
    {
        $ips = gethostbynamel( $pfHostname );
 
        if( $ips !== false )
            $validIps = array_merge( $validIps, $ips );
    }
 
    // Remove duplicates
    $validIps = array_unique( $validIps );
 
    if( !in_array( $_SERVER['REMOTE_ADDR'], $validIps ) )
    {
        $pfError = true;
        $pfErrMsg = PF_ERR_BAD_SOURCE_IP;
    }
}
 
//// Connect to server to validate data received
if( !$pfError )
{
    // Use cURL (If it's available)
    if( function_exists( 'curl_init' ) )
    {
        $output .= "\n\nUsing cURL\n\n"; // DEBUG
 
        // Create default cURL object
        $ch = curl_init();
 
        // Base settings
        $curlOpts = array(
            // Base options
            CURLOPT_USERAGENT => USER_AGENT, // Set user agent
            CURLOPT_RETURNTRANSFER => true,  // Return output as string rather than outputting it
            CURLOPT_HEADER => false,         // Don't include header in output
            CURLOPT_SSL_VERIFYHOST => true,
            CURLOPT_SSL_VERIFYPEER => false,
 
            // Standard settings
            CURLOPT_URL => 'https://'. $pfHost . '/eng/query/validate',
            CURLOPT_POST => true,
            CURLOPT_POSTFIELDS => $pfParamString,
        );
        curl_setopt_array( $ch, $curlOpts );
 
        // Execute CURL
        $res = curl_exec( $ch );
        curl_close( $ch );
 
        if( $res === false )
        {
            $pfError = true;
            $pfErrMsg = PF_ERR_CURL_ERROR;
        }
    }
    // Use fsockopen
    else
    {
        $output .= "\n\nUsing fsockopen\n\n"; // DEBUG
 
        // Construct Header
        $header = "POST /eng/query/validate HTTP/1.0\r\n";
       	$header .= "Host: ". $pfHost ."\r\n";
        $header .= "Content-Type: application/x-www-form-urlencoded\r\n";
        $header .= "Content-Length: " . strlen( $pfParamString ) . "\r\n\r\n";
 
        // Connect to server
        $socket = fsockopen( 'ssl://'. $pfHost, 443, $errno, $errstr, 10 );
 
        // Send command to server
        fputs( $socket, $header . $pfParamString );
 
        // Read the response from the server
        $res = '';
        $headerDone = false;
 
        while( !feof( $socket ) )
        {
            $line = fgets( $socket, 1024 );
 
            // Check if we are finished reading the header yet
            if( strcmp( $line, "\r\n" ) == 0 )
            {
                // read the header
                $headerDone = true;
            }
            // If header has been processed
            else if( $headerDone )
            {
                // Read the main response
                $res .= $line;
            }
        }
    }
}
 
//// Get data from server
if( !$pfError )
{
    // Parse the returned data
    $lines = explode( "\n", $res );
 
    $output .= "\n\nValidate response from server:\n\n"; // DEBUG
 
    foreach( $lines as $line ) // DEBUG
        $output .= $line ."\n"; // DEBUG
}
 
//// Interpret the response from server
if( !$pfError )
{
    // Get the response from PayFast (VALID or INVALID)
    $result = trim( $lines[0] );
 
    $output .= "\nResult = ". $result; // DEBUG
 
    // If the transaction was valid
    if( strcmp( $result, 'VALID' ) == 0 )
    {
        // Process as required
    }
    // If the transaction was NOT valid
    else
    {
        // Log for investigation
        $pfError = true;
        $pfErrMsg = PF_ERR_INVALID_DATA;
    }
}
 
// If an error occurred
if( $pfError )
{
    $output .= "\n\nAn error occurred!";
    $output .= "\nError = ". $pfErrMsg;
}
 
//// Write output to file // DEBUG
file_put_contents( $filename, $output ); // DEBUG
?>

<?php
define( 'SANDBOX', 1 );
 
// Variable Initialization
$pmtToken = isset( $_GET['pt'] ) ? $_GET['pt'] : null;
 
if( !empty( $pmtToken ) )
{
    // Variable Initialization
    $error = false;
    $authToken = '<YOUR_PDT_KEY>';
    $req = 'pt='. $pmtToken .'&at='. $authToken;
    $data = array();
    $host = SANDBOX ? 'sandbox.payfast.co.za' : 'www.payfast.co.za';
 
    //// Connect to server
    if( !$error )
    {
        // Construct Header
        $header = "POST /eng/query/fetch HTTP/1.0\r\n";
        $header .= 'Host: '. $host ."\r\n";
        $header .= "Content-Type: application/x-www-form-urlencoded\r\n";
        $header .= 'Content-Length: '. strlen( $req ) ."\r\n\r\n";
 
        // Connect to server
        $socket = fsockopen( 'ssl://'. $host, 443, $errno, $errstr, 10 );
 
        if( !$socket )
        {
            $error = true;
            print( 'errno = '. $errno .', errstr = '. $errstr );
        }
    }
 
    //// Get data from server
    if( !$error )
    {
        // Send command to server
        fputs( $socket, $header . $req );
 
        // Read the response from the server
        $res = '';
        $headerDone = false;
 
        while( !feof( $socket ) )
        {
            $line = fgets( $socket, 1024 );
 
            // Check if we are finished reading the header yet
            if( strcmp( $line, "\r\n" ) == 0 )
            {
                // read the header
                $headerDone = true;
            }
            // If header has been processed
            else if( $headerDone )
            {
                // Read the main response
                $res .= $line;
            }
        }
 
        // Parse the returned data
        $lines = explode( "\n", $res );
    }
 
    //// Interpret the response from server
    if( !$error )
    {
        $result = trim( $lines[0] );
 
        // If the transaction was successful
        if( strcmp( $result, 'SUCCESS' ) == 0 )
        {
            // Process the reponse into an associative array of data
            for( $i = 1; $i < count( $lines ); $i++ )
            {
                list( $key, $val ) = explode( "=", $lines[$i] );
                $data[urldecode( $key )] = stripslashes( urldecode( $val ) );
            }
        }
        // If the transaction was NOT successful
        else if( strcmp( $result, 'FAIL' ) == 0 )
        {
            // Log for investigation
            $error = true;
            // 
        }
    }
 
    //// Process the payment
    if( !$error )
    {
        // Get the data from the new array as needed
        $nameFirst   = $data['name_first'];
        $nameLast    = $data['name_last'];
        $amountGross = $data['amount_gross'];
 
        // Once you have access to this data, you should perform a number of
        // checks to ensure the transaction is "correct" before processing it.
        // - Check the payment_status is Completed
        // - Check the pf_transaction_id has not already been processed
        // - Check the merchant_id is correct for your account
 
        // Process payment
        // 
    }
 
    // Close socket if successfully opened
    if( $socket )
        fclose( $socket );
}
?>