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

   1 <?php
   2 // Own namespace
   3 namespace CoreFramework\Filter\Verifier\Captcha;
   4
   5 // Import framework stuff
   6 use CoreFramework\Factory\ObjectFactory;
   7
   8 /**
   9  * A concrete filter for validating code graphical CAPTCHAs with hashes
  10  *
  11  * @author              Roland Haeder <webmaster@shipsimu.org>
  12  * @version             0.0.0
  13  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
  14  * @license             GNU GPL 3.0 or any newer version
  15  * @link                http://www.shipsimu.org
  16  *
  17  * This program is free software: you can redistribute it and/or modify
  18  * it under the terms of the GNU General Public License as published by
  19  * the Free Software Foundation, either version 3 of the License, or
  20  * (at your option) any later version.
  21  *
  22  * This program is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  * GNU General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License
  28  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  29  */
  30 class GraphicalCodeCaptchaVerifierFilter extends BaseFilter implements Filterable {
  31         /**
  32          * Protected constructor
  33          *
  34          * @return      void
  35          */
  36         protected function __construct () {
  37                 // Call parent constructor
  38                 parent::__construct(__CLASS__);
  39         }
  40
  41         /**
  42          * Creates an instance of this filter class
  43          *
  44          * @return      $filterInstance         An instance of this filter class
  45          */
  46         public static final function createGraphicalCodeCaptchaVerifierFilter () {
  47                 // Get a new instance
  48                 $filterInstance = new GraphicalCodeCaptchaVerifierFilter();
  49
  50                 // Return the instance
  51                 return $filterInstance;
  52         }
  53
  54         /**
  55          * Executes the filter with given request and response objects
  56          *
  57          * @param       $requestInstance        An instance of a class with an Requestable interface
  58          * @param       $responseInstance       An instance of a class with an Responseable interface
  59          * @return      void
  60          * @throws      FilterChainException    If this filter fails to operate
  61          */
  62         public function execute (Requestable $requestInstance, Responseable $responseInstance) {
  63                 // Is the form set?
  64                 if (($requestInstance->getRequestElement('command') !== 'do_form') ||  (!$requestInstance->isRequestElementSet('form'))) {
  65                         // Required field not set
  66                         $requestInstance->requestIsValid(FALSE);
  67
  68                         // Add fatal message
  69                         $responseInstance->addFatalMessage('command_form_invalid');
  70
  71                         // Skip further processing
  72                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
  73                 } // END - if
  74
  75                 // Create config entry
  76                 $configKey = sprintf('%s_captcha_secured',
  77                         $requestInstance->getRequestElement('form')
  78                 );
  79
  80                 // Is the CAPTCHA enabled?
  81                 if ($this->getConfigInstance()->getConfigEntry($configKey) != 'Y') {
  82                         // Not enabled, so don't check
  83                         return;
  84                 } // END - if
  85
  86                 // Get the captcha code
  87                 $captchaCode = $requestInstance->getRequestElement('c_code');
  88
  89                 // Is this set?
  90                 if (is_null($captchaCode)) {
  91                         // Not set so request is invalid
  92                         $requestInstance->requestIsValid(FALSE);
  93
  94                         // Add fatal message
  95                         $responseInstance->addFatalMessage('captcha_code_unset');
  96
  97                         // Skip further processing
  98                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
  99                 } elseif (empty($captchaCode)) {
 100                         // Empty value so request is invalid
 101                         $requestInstance->requestIsValid(FALSE);
 102
 103                         // Add fatal message
 104                         $responseInstance->addFatalMessage('captcha_code_empty');
 105
 106                         // Skip further processing
 107                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 108                 }
 109
 110                 // Get the hash as well
 111                 $captchaHash = $requestInstance->getRequestElement('hash');
 112
 113                 // Is this set?
 114                 if (is_null($captchaHash)) {
 115                         // Not set so request is invalid
 116                         $requestInstance->requestIsValid(FALSE);
 117
 118                         // Add fatal message
 119                         $responseInstance->addFatalMessage('captcha_hash_unset');
 120
 121                         // Skip further processing
 122                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 123                 } elseif (empty($captchaHash)) {
 124                         // Empty value so request is invalid
 125                         $requestInstance->requestIsValid(FALSE);
 126
 127                         // Add fatal message
 128                         $responseInstance->addFatalMessage('captcha_hash_empty');
 129
 130                         // Skip further processing
 131                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 132                 }
 133
 134                 // Now, both are set hash the given one. First get a crypto instance
 135                 $cryptoInstance = ObjectFactory::createObjectByConfiguredName('crypto_class');
 136
 137                 // Then hash the code
 138                 $hashedCode = $cryptoInstance->hashString($captchaCode, $captchaHash);
 139
 140                 // Is this CAPTCHA valid?
 141                 if ($hashedCode != $captchaHash) {
 142                         // Not the same so request is invalid
 143                         $requestInstance->requestIsValid(FALSE);
 144
 145                         // Add fatal message
 146                         $responseInstance->addFatalMessage('captcha_hash_mismatch');
 147
 148                         // Skip further processing
 149                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 150                 } // END - not the same!
 151         }
 152
 153 }