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

   1 <?php
   2 // Own namespace
   3 namespace Org\Mxchange\CoreFramework\Filter\Verifier\Captcha;
   4
   5 // Import framework stuff
   6 use Org\Mxchange\CoreFramework\Bootstrap\FrameworkBootstrap;
   7 use Org\Mxchange\CoreFramework\Factory\Object\ObjectFactory;
   8 use Org\Mxchange\CoreFramework\Filter\BaseFilter;
   9 use Org\Mxchange\CoreFramework\Filter\Chain\FilterChainException;
  10 use Org\Mxchange\CoreFramework\Filter\Filterable;
  11 use Org\Mxchange\CoreFramework\Request\Requestable;
  12 use Org\Mxchange\CoreFramework\Response\Responseable;
  13
  14 /**
  15  * A concrete filter for validating code graphical CAPTCHAs with hashes
  16  *
  17  * @author              Roland Haeder <webmaster@shipsimu.org>
  18  * @version             0.0.0
  19  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2021 Core Developer Team
  20  * @license             GNU GPL 3.0 or any newer version
  21  * @link                http://www.shipsimu.org
  22  *
  23  * This program is free software: you can redistribute it and/or modify
  24  * it under the terms of the GNU General Public License as published by
  25  * the Free Software Foundation, either version 3 of the License, or
  26  * (at your option) any later version.
  27  *
  28  * This program is distributed in the hope that it will be useful,
  29  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  30  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  31  * GNU General Public License for more details.
  32  *
  33  * You should have received a copy of the GNU General Public License
  34  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  35  */
  36 class GraphicalCodeCaptchaVerifierFilter extends BaseFilter implements Filterable {
  37         /**
  38          * Protected constructor
  39          *
  40          * @return      void
  41          */
  42         private function __construct () {
  43                 // Call parent constructor
  44                 parent::__construct(__CLASS__);
  45         }
  46
  47         /**
  48          * Creates an instance of this filter class
  49          *
  50          * @return      $filterInstance         An instance of this filter class
  51          */
  52         public static final function createGraphicalCodeCaptchaVerifierFilter () {
  53                 // Get a new instance
  54                 $filterInstance = new GraphicalCodeCaptchaVerifierFilter();
  55
  56                 // Return the instance
  57                 return $filterInstance;
  58         }
  59
  60         /**
  61          * Executes the filter with given request and response objects
  62          *
  63          * @param       $requestInstance        An instance of a class with an Requestable interface
  64          * @param       $responseInstance       An instance of a class with an Responseable interface
  65          * @return      void
  66          * @throws      FilterChainException    If this filter fails to operate
  67          */
  68         public function execute (Requestable $requestInstance, Responseable $responseInstance) {
  69                 // Is the form set?
  70                 if (($requestInstance->getRequestElement('command') !== 'do_form') || (!$requestInstance->isRequestElementSet('form'))) {
  71                         // Required field not set
  72                         $requestInstance->requestIsValid(false);
  73
  74                         // Add fatal message
  75                         $responseInstance->addFatalMessage('command_form_invalid');
  76
  77                         // Skip further processing
  78                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
  79                 } // END - if
  80
  81                 // Create config entry
  82                 $configKey = sprintf('%s_captcha_secured',
  83                         $requestInstance->getRequestElement('form')
  84                 );
  85
  86                 // Is the CAPTCHA enabled?
  87                 if (FrameworkBootstrap::getConfigurationInstance()->getConfigEntry($configKey) != 'Y') {
  88                         // Not enabled, so don't check
  89                         return;
  90                 } // END - if
  91
  92                 // Get the captcha code
  93                 $captchaCode = $requestInstance->getRequestElement('c_code');
  94
  95                 // Is this set?
  96                 if (is_null($captchaCode)) {
  97                         // Not set so request is invalid
  98                         $requestInstance->requestIsValid(false);
  99
 100                         // Add fatal message
 101                         $responseInstance->addFatalMessage('captcha_code_unset');
 102
 103                         // Skip further processing
 104                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 105                 } elseif (empty($captchaCode)) {
 106                         // Empty value so request is invalid
 107                         $requestInstance->requestIsValid(false);
 108
 109                         // Add fatal message
 110                         $responseInstance->addFatalMessage('captcha_code_empty');
 111
 112                         // Skip further processing
 113                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 114                 }
 115
 116                 // Get the hash as well
 117                 $captchaHash = $requestInstance->getRequestElement('hash');
 118
 119                 // Is this set?
 120                 if (is_null($captchaHash)) {
 121                         // Not set so request is invalid
 122                         $requestInstance->requestIsValid(false);
 123
 124                         // Add fatal message
 125                         $responseInstance->addFatalMessage('captcha_hash_unset');
 126
 127                         // Skip further processing
 128                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 129                 } elseif (empty($captchaHash)) {
 130                         // Empty value so request is invalid
 131                         $requestInstance->requestIsValid(false);
 132
 133                         // Add fatal message
 134                         $responseInstance->addFatalMessage('captcha_hash_empty');
 135
 136                         // Skip further processing
 137                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 138                 }
 139
 140                 // Now, both are set hash the given one. First get a crypto instance
 141                 $cryptoInstance = ObjectFactory::createObjectByConfiguredName('crypto_class');
 142
 143                 // Then hash the code
 144                 $hashedCode = $cryptoInstance->hashString($captchaCode, $captchaHash);
 145
 146                 // Is this CAPTCHA valid?
 147                 if ($hashedCode != $captchaHash) {
 148                         // Not the same so request is invalid
 149                         $requestInstance->requestIsValid(false);
 150
 151                         // Add fatal message
 152                         $responseInstance->addFatalMessage('captcha_hash_mismatch');
 153
 154                         // Skip further processing
 155                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 156                 } // END - not the same!
 157         }
 158
 159 }