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 use CoreFramework\Request\Requestable;
   8
   9 /**
  10  * A concrete filter for validating code graphical CAPTCHAs with hashes
  11  *
  12  * @author              Roland Haeder <webmaster@shipsimu.org>
  13  * @version             0.0.0
  14  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
  15  * @license             GNU GPL 3.0 or any newer version
  16  * @link                http://www.shipsimu.org
  17  *
  18  * This program is free software: you can redistribute it and/or modify
  19  * it under the terms of the GNU General Public License as published by
  20  * the Free Software Foundation, either version 3 of the License, or
  21  * (at your option) any later version.
  22  *
  23  * This program is distributed in the hope that it will be useful,
  24  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  * GNU General Public License for more details.
  27  *
  28  * You should have received a copy of the GNU General Public License
  29  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  30  */
  31 class GraphicalCodeCaptchaVerifierFilter extends BaseFilter implements Filterable {
  32         /**
  33          * Protected constructor
  34          *
  35          * @return      void
  36          */
  37         protected function __construct () {
  38                 // Call parent constructor
  39                 parent::__construct(__CLASS__);
  40         }
  41
  42         /**
  43          * Creates an instance of this filter class
  44          *
  45          * @return      $filterInstance         An instance of this filter class
  46          */
  47         public static final function createGraphicalCodeCaptchaVerifierFilter () {
  48                 // Get a new instance
  49                 $filterInstance = new GraphicalCodeCaptchaVerifierFilter();
  50
  51                 // Return the instance
  52                 return $filterInstance;
  53         }
  54
  55         /**
  56          * Executes the filter with given request and response objects
  57          *
  58          * @param       $requestInstance        An instance of a class with an Requestable interface
  59          * @param       $responseInstance       An instance of a class with an Responseable interface
  60          * @return      void
  61          * @throws      FilterChainException    If this filter fails to operate
  62          */
  63         public function execute (Requestable $requestInstance, Responseable $responseInstance) {
  64                 // Is the form set?
  65                 if (($requestInstance->getRequestElement('command') !== 'do_form') ||  (!$requestInstance->isRequestElementSet('form'))) {
  66                         // Required field not set
  67                         $requestInstance->requestIsValid(FALSE);
  68
  69                         // Add fatal message
  70                         $responseInstance->addFatalMessage('command_form_invalid');
  71
  72                         // Skip further processing
  73                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
  74                 } // END - if
  75
  76                 // Create config entry
  77                 $configKey = sprintf('%s_captcha_secured',
  78                         $requestInstance->getRequestElement('form')
  79                 );
  80
  81                 // Is the CAPTCHA enabled?
  82                 if ($this->getConfigInstance()->getConfigEntry($configKey) != 'Y') {
  83                         // Not enabled, so don't check
  84                         return;
  85                 } // END - if
  86
  87                 // Get the captcha code
  88                 $captchaCode = $requestInstance->getRequestElement('c_code');
  89
  90                 // Is this set?
  91                 if (is_null($captchaCode)) {
  92                         // Not set so request is invalid
  93                         $requestInstance->requestIsValid(FALSE);
  94
  95                         // Add fatal message
  96                         $responseInstance->addFatalMessage('captcha_code_unset');
  97
  98                         // Skip further processing
  99                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 100                 } elseif (empty($captchaCode)) {
 101                         // Empty value so request is invalid
 102                         $requestInstance->requestIsValid(FALSE);
 103
 104                         // Add fatal message
 105                         $responseInstance->addFatalMessage('captcha_code_empty');
 106
 107                         // Skip further processing
 108                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 109                 }
 110
 111                 // Get the hash as well
 112                 $captchaHash = $requestInstance->getRequestElement('hash');
 113
 114                 // Is this set?
 115                 if (is_null($captchaHash)) {
 116                         // Not set so request is invalid
 117                         $requestInstance->requestIsValid(FALSE);
 118
 119                         // Add fatal message
 120                         $responseInstance->addFatalMessage('captcha_hash_unset');
 121
 122                         // Skip further processing
 123                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 124                 } elseif (empty($captchaHash)) {
 125                         // Empty value so request is invalid
 126                         $requestInstance->requestIsValid(FALSE);
 127
 128                         // Add fatal message
 129                         $responseInstance->addFatalMessage('captcha_hash_empty');
 130
 131                         // Skip further processing
 132                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 133                 }
 134
 135                 // Now, both are set hash the given one. First get a crypto instance
 136                 $cryptoInstance = ObjectFactory::createObjectByConfiguredName('crypto_class');
 137
 138                 // Then hash the code
 139                 $hashedCode = $cryptoInstance->hashString($captchaCode, $captchaHash);
 140
 141                 // Is this CAPTCHA valid?
 142                 if ($hashedCode != $captchaHash) {
 143                         // Not the same so request is invalid
 144                         $requestInstance->requestIsValid(FALSE);
 145
 146                         // Add fatal message
 147                         $responseInstance->addFatalMessage('captcha_hash_mismatch');
 148
 149                         // Skip further processing
 150                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 151                 } // END - not the same!
 152         }
 153
 154 }