/app/code/community/Fontis/Recaptcha/Helper/Data.php

<?php

/**

 * Fontis Recaptcha Extension

 *

 * NOTICE OF LICENSE

 *

 * This source file is subject to the Open Software License (OSL 3.0)

 * that is bundled with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://opensource.org/licenses/osl-3.0.php

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@magentocommerce.com so we can send you a copy immediately.

 * 

 * This code has been adopted from the reCAPTCHA module available at:

 * 	http://www.google.com/recaptcha

 * The original reCAPTCHA module was written by:

 * 	Mike Crawford

 * 	Ben Maurer

 *

 * @category   Fontis

 * @package    Fontis_Recaptcha

 * @author     Denis Margetic

 * @author     Chris Norton

 * @copyright  Copyright (c) 2011 Fontis Pty. Ltd. (http://www.fontis.com.au)

 * @license    http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)

 */

class Fontis_Recaptcha_Helper_Data extends Mage_Core_Helper_Abstract 

{

    const RECAPTCHA_API_SERVER_HOST = "www.google.com";

    const RECAPTCHA_API_SERVER_PATH = "/recaptcha/api";

    const RECAPTCHA_API_SECURE_SERVER = "https://www.google.com/recaptcha/api";



    /**

     * Encodes the given data into a query string format

     * @param $data - array of string elements to be encoded

     * @return string - encoded request

     */

    function _recaptcha_qsencode ($data) 

    {

        $req = "";

        foreach ( $data as $key => $value )

            $req .= $key . '=' . urlencode( stripslashes($value) ) . '&';



        // Cut the last '&'

        $req=substr($req,0,strlen($req)-1);

        return $req;

    }



    /**

     * Submits an HTTP POST to a reCAPTCHA server

     * @param string $host

     * @param string $path

     * @param array $data

     * @param int port

     * @return array response

     */

    function _recaptcha_http_post($host, $path, $data, $port = 80) 

    {

        $req = $this->_recaptcha_qsencode ($data);



        $http_request  = "POST $path HTTP/1.0\r\n";

        $http_request .= "Host: $host\r\n";

        $http_request .= "Content-Type: application/x-www-form-urlencoded;\r\n";

        $http_request .= "Content-Length: " . strlen($req) . "\r\n";

        $http_request .= "User-Agent: reCAPTCHA/PHP\r\n";

        $http_request .= "\r\n";

        $http_request .= $req;



        $response = '';

        if( false == ( $fs = @fsockopen($host, $port, $errno, $errstr, 10) ) ) {

            die ('Could not open socket');

        }



        fwrite($fs, $http_request);



        while ( !feof($fs) )

            $response .= fgets($fs, 1160); // One TCP-IP packet

        fclose($fs);

        $response = explode("\r\n\r\n", $response, 2);



        return $response;

    }



    /**

     * Gets the challenge HTML (javascript and non-javascript version).

     * This is called from the browser, and the resulting reCAPTCHA HTML widget

     * is embedded within the HTML form it was called from.

     * @param string $pubkey A public key for reCAPTCHA

     * @param string $error The error given by reCAPTCHA (optional, default is null)

     * @param boolean $use_ssl Should the request be made over ssl? (optional, default is false)



     * @return string - The HTML to be embedded in the user's form.

     */

    function recaptcha_get_html ($pubkey, $error = null, $use_ssl = false)

    {

	    if ($pubkey == null || $pubkey == '') {

		    die ("To use reCAPTCHA you must get an API key from <a href='http://recaptcha.net/api/getkey'>http://recaptcha.net/api/getkey</a>");

	    }

	

	    if ($use_ssl) {

            $server = self::RECAPTCHA_API_SECURE_SERVER;

        } else {

            $server = 'http://' . self::RECAPTCHA_API_SERVER_HOST . self::RECAPTCHA_API_SERVER_PATH;

        }



        $errorpart = "";

        if ($error) {

           $errorpart = "&amp;error=" . $error;

        }

        return '<script type="text/javascript" src="'. $server . '/challenge?k=' . $pubkey . $errorpart . '"></script>



	    <noscript>

  		    <iframe src="'. $server . '/noscript?k=' . $pubkey . $errorpart . '" height="300" width="500" frameborder="0"></iframe><br/>

  		    <textarea name="recaptcha_challenge_field" rows="3" cols="40"></textarea>

  		    <input type="hidden" name="recaptcha_response_field" value="manual_challenge"/>

	    </noscript>';

    }



    /**

      * Calls an HTTP POST function to verify if the user's guess was correct

      * @param string $privkey

      * @param string $remoteip

      * @param string $challenge

      * @param string $response

      * @param array $extra_params an array of extra variables to post to the server

      * @return ReCaptchaResponse

      */

    function recaptcha_check_answer ($privkey, $remoteip, $challenge, $response, $extra_params = array())

    {

	    if ($privkey == null || $privkey == '') {

		    die ("To use reCAPTCHA you must get an API key from <a href='http://recaptcha.net/api/getkey'>http://recaptcha.net/api/getkey</a>");

	    }



	    if ($remoteip == null || $remoteip == '') {

		    die ("For security reasons, you must pass the remote ip to reCAPTCHA");

	    }

	

        //discard spam submissions

        if ($challenge == null || strlen($challenge) == 0 || $response == null || strlen($response) == 0) {

            return false;

        }



        $response = $this->_recaptcha_http_post (self::RECAPTCHA_API_SERVER_HOST, self::RECAPTCHA_API_SERVER_PATH . "/verify", array (  'privatekey' => $privkey,

                                                                                                                            'remoteip' => $remoteip,

                                                                                                                            'challenge' => $challenge,

                                                                                                                            'response' => $response

                                                                                                                         ) + $extra_params

                                                );



        $answers = explode ("\n", $response [1]);



        if (trim ($answers [0]) == 'true') {

            return true;

        }

        return false;

    }



    /**

     * gets a URL where the user can sign up for reCAPTCHA. If your application

     * has a configuration page where you enter a key, you should provide a link

     * using this function.

     * @param string $domain The domain where the page is hosted

     * @param string $appname The name of your application

     */

    function recaptcha_get_signup_url ($domain = null, $appname = null) 

    {

	    return "http://recaptcha.net/api/getkey?" .  $this->_recaptcha_qsencode (array ('domain' => $domain, 'app' => $appname));

    }



    function _recaptcha_aes_pad($val) 

    {

	    $block_size = 16;

	    $numpad = $block_size - (strlen ($val) % $block_size);

	    return str_pad($val, strlen ($val) + $numpad, chr($numpad));

    }

}

?>