GP Webpay

<?php if (!defined('BASEPATH')) exit('No direct script access allowed');

class Epay_gpwebpay
{
    var $private_key, $password, $public_key, $digest;

    public $params = array();


    var $options    = array(
        'MERCHANTNUMBER'    => GP_WEBPAY_MID,
        'OPERATION'     => 'CREATE_ORDER',
        'CURRENCY'      => '978',
        'DEPOSITFLAG'       => 1,
        'DESCRIPTION'       => 'nejaky text',
        'MD'            => 'nejaky text'
        );

    function __construct()
    {
        $this->CI =& get_instance();
    }

    function sign($key, $password)
    {
        $fp = fopen($key, "r");
        $this->private_key = fread($fp, filesize($key));
        fclose($fp);
        $this->password=$password;

        $digestValue = implode('|', $this->params);

        $keyid = openssl_get_privatekey($this->private_key, $this->password);
        openssl_sign($digestValue, $this->digest, $keyid);
        $this->digest = base64_encode($this->digest);
        openssl_free_key($keyid);
    }

    function verify($key)
    {
        $fp = fopen($key, "r");
        $this->public_key = fread($fp, filesize($key));
        fclose($fp);

        $pubcertid = openssl_get_publickey($this->public_key);
        $digest = base64_decode($this->digest);
        $data = implode('|', $this->params);
        $result = openssl_verify($data, $digest, $pubcertid);
        openssl_free_key($pubcertid);
        return (($result == 1) ? true : false);
    }

    function send_request($data)
    {

        $this->params['MERCHANTNUMBER'] = $this->options['MERCHANTNUMBER'];
        $this->params['OPERATION'] = $this->options['OPERATION'];
        $this->params['ORDERNUMBER'] = $data['variable_symbol'];
        $this->params['AMOUNT'] = $data['price'] * 100;
        $this->params['CURRENCY'] = $this->options['CURRENCY'];
        $this->params['DEPOSITFLAG'] = $this->options['DEPOSITFLAG'];
        $this->params['MERORDERNUM'] = $data['variable_symbol'];
        $this->params['URL'] = $data['redirect_url'];
        $this->params['DESCRIPTION'] = $this->options['DESCRIPTION'];
        $this->params['MD'] = base64_encode($this->options['MD']);

        $this->sign(GP_WEBPAY_PRIVATE_KEY, GP_WEBPAY_PASSWORD);

        if (isset($this->digest))
        {
            $this->params['DIGEST'] = $this->digest;
            $this->params = array_map('urlencode', $this->params);
            array_walk($this->params, create_function('&$val, $key', '$val = "$key=$val";'));

            return GP_WEBPAY_URL . "?" . implode('&', $this->params);
        }
        else
        {
            return false;
        }
    }

    function receive_response() {

    $this->params = array();
    $this->params['OPERATION'] = isset($_GET['OPERATION']) ? $_GET['OPERATION'] : '';
    $this->params['ORDERNUMBER'] = isset($_GET['ORDERNUMBER']) ? $_GET['ORDERNUMBER'] : '';
    $this->params['MERORDERNUM'] = isset($_GET['MERORDERNUM']) ? $_GET['MERORDERNUM'] : '';
    $this->params['MD'] = isset($_GET['MD']) ? $_GET['MD'] : '';
    $this->params['PRCODE'] = isset($_GET['PRCODE']) ? $_GET['PRCODE'] : '';
    $this->params['SRCODE'] = isset($_GET['SRCODE']) ? $_GET['SRCODE'] : '';
    $this->params['RESULTTEXT'] = isset($_GET['RESULTTEXT']) ? $_GET['RESULTTEXT'] : '';

    $this->digest = isset($_GET['DIGEST']) ? $_GET['DIGEST'] : '';

    return ($this->verify(GP_WEBPAY_PUBLIC_KEY) && ($this->params['PRCODE'] == 0) && ($this->params['SRCODE'] == 0)) ? true : false;

  }
}
?>