inc/classes/main/filter/verifier/class_GraphicalCodeCaptchaVerifierFilter.php

   1 <?php
   2 /**
   3  * A concrete filter for validating code graphical CAPTCHAs with hashes
   4  *
   5  * @author              Roland Haeder <webmaster@shipsimu.org>
   6  * @version             0.0.0
   7  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2015 Core Developer Team
   8  * @license             GNU GPL 3.0 or any newer version
   9  * @link                http://www.shipsimu.org
  10  *
  11  * This program is free software: you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation, either version 3 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  23  */
  24 class GraphicalCodeCaptchaVerifierFilter extends BaseFilter implements Filterable {
  25         /**
  26          * Protected constructor
  27          *
  28          * @return      void
  29          */
  30         protected function __construct () {
  31                 // Call parent constructor
  32                 parent::__construct(__CLASS__);
  33         }
  34
  35         /**
  36          * Creates an instance of this filter class
  37          *
  38          * @return      $filterInstance         An instance of this filter class
  39          */
  40         public static final function createGraphicalCodeCaptchaVerifierFilter () {
  41                 // Get a new instance
  42                 $filterInstance = new GraphicalCodeCaptchaVerifierFilter();
  43
  44                 // Return the instance
  45                 return $filterInstance;
  46         }
  47
  48         /**
  49          * Executes the filter with given request and response objects
  50          *
  51          * @param       $requestInstance        An instance of a class with an Requestable interface
  52          * @param       $responseInstance       An instance of a class with an Responseable interface
  53          * @return      void
  54          * @throws      FilterChainException    If this filter fails to operate
  55          */
  56         public function execute (Requestable $requestInstance, Responseable $responseInstance) {
  57                 // Get the captcha code
  58                 $captchaCode = $requestInstance->getRequestElement('c_code');
  59
  60                 // Is this set?
  61                 if (is_null($captchaCode)) {
  62                         // Not set so request is invalid
  63                         $requestInstance->requestIsValid(FALSE);
  64
  65                         // Add fatal message
  66                         $responseInstance->addFatalMessage('captcha_code_unset');
  67
  68                         // Skip further processing
  69                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
  70                 } elseif (empty($captchaCode)) {
  71                         // Empty value so request is invalid
  72                         $requestInstance->requestIsValid(FALSE);
  73
  74                         // Add fatal message
  75                         $responseInstance->addFatalMessage('captcha_code_empty');
  76
  77                         // Skip further processing
  78                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
  79                 }
  80
  81                 // Get the hash as well
  82                 $captchaHash = $requestInstance->getRequestElement('hash');
  83
  84                 // Is this set?
  85                 if (is_null($captchaHash)) {
  86                         // Not set so request is invalid
  87                         $requestInstance->requestIsValid(FALSE);
  88
  89                         // Add fatal message
  90                         $responseInstance->addFatalMessage('captcha_hash_unset');
  91
  92                         // Skip further processing
  93                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
  94                 } elseif (empty($captchaHash)) {
  95                         // Empty value so request is invalid
  96                         $requestInstance->requestIsValid(FALSE);
  97
  98                         // Add fatal message
  99                         $responseInstance->addFatalMessage('captcha_hash_empty');
 100
 101                         // Skip further processing
 102                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 103                 }
 104
 105                 // Now, both are set hash the given one. First get a crypto instance
 106                 $cryptoInstance = ObjectFactory::createObjectByConfiguredName('crypto_class');
 107
 108                 // Then hash the code
 109                 $hashedCode = $cryptoInstance->hashString($captchaCode, $captchaHash);
 110
 111                 // Is this CAPTCHA valid?
 112                 if ($hashedCode != $captchaHash) {
 113                         // Not the same so request is invalid
 114                         $requestInstance->requestIsValid(FALSE);
 115
 116                         // Add fatal message
 117                         $responseInstance->addFatalMessage('captcha_hash_mismatch');
 118
 119                         // Skip further processing
 120                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 121                 } // END - not the same!
 122         }
 123 }
 124
 125 // [EOF]
 126 ?>