<?php
 
/**
 
  * This file contains the HelloCaptcha class that is the essential
 
  * PHP class for embedding HelloCaptcha CAPTCHAs.
 
  * 
 
  * The most recent version of this file can be downloaded from:
 
  * http://www.hellocaptcha.com/dl/HelloCaptcha.class.php
 
  *
 
  * A sample file that demonstrates how to use this class can be
 
  * downloaded from:
 
  * http://www.hellocaptcha.com/dl/sample-captcha.php
 
  *
 
  * PHP versions before 5.2 do not have JSON support enabled. To solve
 
  * this issue download JSON.php from our server and place it near the
 
  * HelloCaptcha.class.php file. The HelloCaptcha.class.php file
 
  * automatically includes it if neccessary. The file can be downloaded
 
  * from:
 
  * http://www.hellocaptcha.com/dl/JSON.php
 
  *
 
  * @see http://www.hellocaptcha.com
 
  * @see http://www.hellocaptcha.com/doc/embedding
 
  * @Copyright Program Produkt, 2010-2011
 
  */
 
 
 
/** Version */
 
define("HELLOCAPTCHA_VERSION", "1.0");
 
/** Release date */
 
define("HELLOCAPTCHA_RELEASE_DATE", "2011-02-07");
 
 
 
/**
 
  * This if will be used, if profile is not set. You can override this
 
  * constant by defining it before including this file.
 
  */
 
define("HELLOCAPTCHA_TRIAL_PROFILE_ID", "hellocaptchatrialprofile");
 
/** HelloCaptcha service domain */
 
define("HELLOCAPTCHA_SERVER_DOMAIN", "service.hellocaptcha.com");
 
/** Path for verifying user's answer */
 
define("HELLOCAPTCHA_GET_NEW_TEST_PATH", "/getnewtest/");
 
/** Path for verifying user's answer */
 
define("HELLOCAPTCHA_VERIFY_ANSWER_PATH", "/verifyanswer/");
 
 
 
/** Error codes for getNewTest */
 
define("HELLOCAPTCHA_ERROR_1", "The profile named profileid does not exist.");
 
define("HELLOCAPTCHA_ERROR_2", "There is no pre-rendered CAPTCHA in the profile pool, yet. Please wait, until HelloCaptcha server generates the CAPTCHA animations.");
 
 
 
/** Error codes for verifyAnswer */
 
define("HELLOCAPTCHA_ERROR_3", "The Turing test identified by turingtestid does not exist.");
 
define("HELLOCAPTCHA_ERROR_4", "Either test turingtestid or answer is empty.");
 
define("HELLOCAPTCHA_ERROR_5", "The Turing test was already verified once.");
 
define("HELLOCAPTCHA_ERROR_6", "The Turing test is expired."); 
 
define("HELLOCAPTCHA_ERROR_7", "There are too many bad tries (on a retryable CAPTCHA)."); 
 
 
 
/**
 
  * Class that wraps functionality of HelloCaptcha service by implementing HTTP based
 
  * communication and creating wrapper methods for HelloCaptcha service. This class
 
  * should be used if someone needs custom functionality of this service. The HelloCaptcha
 
  * class is based on the functions of this class.
 
  *
 
  * @version 1.0
 
  */
 
class HelloCaptchaWrapper {
 
 
 
  /**
 
    * Converts an error code to string
 
    *
 
    * @param int $p_error_code
 
    * @return string response
 
    */
 
  public static function errorCodeToString( $p_errorcode ) {
 
    $cn = "HELLOCAPTCHA_ERROR_" . $p_errorcode;
 
    if ( defined( $cn ) )
 
      return constant( $cn );
 
    else
 
      return "Unknown error.";
 
  }
 
 
 
  /**
 
    * Submits an HTTP POST to a server and returns its result.
 
    *
 
    * @param string $p_host
 
    * @param string $p_path
 
    * @param array $p_data
 
    * @param int $p_port
 
    * @return string response
 
    */
 
  private static function doHTTPPost( $p_host, $p_path, $p_data, $p_port = 80 ) {
 
 
 
      // Url encode the passed values
 
    $request = Array();
 
    foreach ( $p_data as $key => $value ) {
 
      $request[] = $key . '=' . urlencode( stripslashes($value) );
 
    }
 
    $request = implode('&', $request);
 
 
 
    // Create HTTP request string
 
    $http_request  = "POST $p_path HTTP/1.0
";
 
    $http_request .= "Host: $p_host
";
 
    $http_request .= "Content-Type: application/x-www-form-urlencoded;
";
 
    $http_request .= "Content-Length: " . strlen($request) . "
";
 
    $http_request .= "User-Agent: HELLOCAPTCHA/PHP
";
 
    $http_request .= "
";
 
    $http_request .= $request;
 
 
 
    // Connect to server
 
    if( false == ( $fs = @fsockopen($p_host, $p_port, $errno, $errstr, 10) ) )
 
      throw new Exception( __METHOD__ . ': Cannot connect to server: ' . $p_host . ' on port: ' . $p_port . '.' );
 
 
 
    // Do the request
 
    fwrite($fs, $http_request);
 
 
 
    // Get the response
 
    $response = '';
 
    while ( !feof($fs) ) {
 
      // One TCP-IP packet
 
      $response .= fgets($fs, 1160);
 
    }
 
 
 
    // Disconnect from the server
 
    fclose($fs);
 
 
 
    // Return the response
 
    return $response;
 
  }
 
 
 
  /**
 
    * Decodes a server response response is valid. If the response contains an exception
 
    * then throws it.
 
    */
 
  protected static function decodeResponse( $p_response ) {
 
    $p_response = explode("
 
", $p_response, 2);
 
    $p_response = $p_response[1];
 
 
 
    // Check response for trivial errors
 
    if ( is_null( $p_response ) )
 
      throw new Exception( __METHOD__ . ': Server response is NULL.' );
 
    if ( empty( $p_response ) )
 
      throw new Exception( __METHOD__ . ': Server response is EMPTY.' );
 
 
 
    // JSON decode
 
    $response = json_decode( $p_response, TRUE );
 
    if ( NULL === $response )
 
      throw new Exception( __METHOD__ . ': Error decoding server response.' );
 
 
 
    // Check for exception
 
    if ( !empty( $response['e'] ) )
 
      throw new Exception( __METHOD__ . ': Server returned an error: ' . $response['e']['message'], $response['e']['code'] );
 
 
 
    // Return value if not empty
 
    if ( empty( $response['d'] ) )
 
      throw new Exception( __METHOD__ . ': Server returned empty data' );
 
    return $response['d'];
 
  }
 
 
 
  /**
 
    * Calls remote service and return the result.
 
    *
 
    * @param string $p_path
 
    * @param array $p_data
 
    * @return array response
 
    */
 
  protected static function callRemote( $p_path, $p_data ) {
 
 
 
    // Post data over HTTP
 
    $response = self::doHTTPPost( HELLOCAPTCHA_SERVER_DOMAIN, $p_path, $p_data );
 
 
 
    // Decode and return response
 
    $response = self::decodeResponse( $response );
 
    return $response;
 
  }
 
 
 
  /**
 
    * Creates a new Turing test and returns the received result.
 
    *
 
    * @param string $p_profileid
 
    * @return array response
 
    */
 
  public function getNewTest( $p_profileid = HELLOCAPTCHA_TRIAL_PROFILE_ID ) {
 
 
 
    // Call remote service
 
    return self::callRemote(
 
      HELLOCAPTCHA_GET_NEW_TEST_PATH,
 
      Array( 'profileid' => $p_profileid )
 
    );
 
  }
 
 
 
  /**
 
    * Checks the answer for a given Turing test.
 
    *
 
    * @param string $p_turingtestid
 
    * @param string $p_answer
 
    * @return array response
 
    */
 
  public function verifyAnswer( $p_turingtestid, $p_answer ) {
 
 
 
    // Assert Turing test id is not empty
 
    if ( empty( $p_turingtestid ) )
 
      die (__METHOD__ . ": Turing test id is empty. Please specify Turing test id to let the system know which test was completed. A new test id can be obtained on http://www.hellocaptcha.com/registration/ .");
 
    // Assert answer is not empty
 
    if ( empty( $p_answer ) )
 
      die (__METHOD__ . ": Answer is empty. Please specify answer to let the system know what to evaluate.");
 
 
 
    // Call remote service
 
    return self::callRemote(
 
      HELLOCAPTCHA_VERIFY_ANSWER_PATH,
 
      Array( 'turingtestid' => $p_turingtestid, 'answer' => $p_answer )
 
    );
 
  }
 
 
 
}
 
 
 
/**
 
  * Class that provides high level functionality for HelloCaptcha service.
 
  * This class uses the low level methods of HelloCaptchaWrapper class. If you need
 
  * custom behaviour, you can create a custom class (MyHelloCaptcha) by modifying this
 
  * class or by derivating from it.
 
  */
 
class HelloCaptcha extends HelloCaptchaWrapper {
 
 
 
  /**
 
    * Asks for a new test on HelloCaptcha server and returns a default
 
    * embedding code for the CAPTCHA of the given profile.
 
    */
 
  public static function getEmbedCode( $p_profileid = HELLOCAPTCHA_TRIAL_PROFILE_ID  ) {
 
    try {
 
      // Call wrapper method, and return the ready-made part of the answer.
 
      $res = self::getNewTest( $p_profileid );
 
      return $res['html'];
 
    } catch (Exception $e) {
 
      echo "Error acquiring HelloCaptcha embedding code. " . self::errorCodeToString( $e->getCode() );
 
      error_log( __METHOD__ . ": Unexpected error occured. Error message: " . self::errorCodeToString( $e->getCode() ) ); 
 
      error_log( __METHOD__ . ": Unexpected error occured. HelloCaptcha server said: " . $e->getMessage() ); 
 
    }
 
  }
 
 
 
  public static function checkAnswer( $p_turingtestid, $p_answer ) {
 
    try {
 
      // Call wrapper method, and return the validity of the answer.
 
      $res = self::verifyAnswer( $p_turingtestid, $p_answer );
 
      return $res['is_valid'];
 
    } catch (Exception $e) {
 
      echo "Error checking user answer for HelloCaptcha. " . self::errorCodeToString( $e->getCode() ) . "<br />";
 
      error_log( __METHOD__ . ": Unexpected error occured. Error message: " . self::errorCodeToString( $e->getCode() ) );
 
      error_log( __METHOD__ . ": Unexpected error occured. HelloCaptcha server said: " . $e->getMessage() );
 
      return false;
 
    }
 
  }
 
 
 
}
 
 
 
if ( !function_exists('json_decode') ) {
 
  function json_decode($p_content, $p_assoc = true) {
 
    require_once 'JSON.php';
 
    if ( $p_assoc ) {
 
      $json = new Services_JSON(SERVICES_JSON_LOOSE_TYPE);
 
    } else {
 
      $json = new Services_JSON;
 
    }
 
    return $json->decode($p_content);
 
  }
 
}
 
 
 
if ( !function_exists('json_encode') ){
 
  function json_encode($p_content){
 
    require_once 'JSON.php';
 
    $json = new Services_JSON;
 
    return $json->encode($p_content);
 
  }
 
}
 
 
 
?>