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\Factory\ObjectFactory;
   7 use Org\Mxchange\CoreFramework\Filter\BaseFilter;
   8 use Org\Mxchange\CoreFramework\Filter\Filterable;
   9 use Org\Mxchange\CoreFramework\Request\Requestable;
  10 use Org\Mxchange\CoreFramework\Response\Responseable;
  11
  12 /**
  13  * A concrete filter for validating code graphical CAPTCHAs with hashes
  14  *
  15  * @author              Roland Haeder <webmaster@shipsimu.org>
  16  * @version             0.0.0
  17  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
  18  * @license             GNU GPL 3.0 or any newer version
  19  * @link                http://www.shipsimu.org
  20  *
  21  * This program is free software: you can redistribute it and/or modify
  22  * it under the terms of the GNU General Public License as published by
  23  * the Free Software Foundation, either version 3 of the License, or
  24  * (at your option) any later version.
  25  *
  26  * This program is distributed in the hope that it will be useful,
  27  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  28  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  29  * GNU General Public License for more details.
  30  *
  31  * You should have received a copy of the GNU General Public License
  32  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  33  */
  34 class GraphicalCodeCaptchaVerifierFilter extends BaseFilter implements Filterable {
  35         /**
  36          * Protected constructor
  37          *
  38          * @return      void
  39          */
  40         protected function __construct () {
  41                 // Call parent constructor
  42                 parent::__construct(__CLASS__);
  43         }
  44
  45         /**
  46          * Creates an instance of this filter class
  47          *
  48          * @return      $filterInstance         An instance of this filter class
  49          */
  50         public static final function createGraphicalCodeCaptchaVerifierFilter () {
  51                 // Get a new instance
  52                 $filterInstance = new GraphicalCodeCaptchaVerifierFilter();
  53
  54                 // Return the instance
  55                 return $filterInstance;
  56         }
  57
  58         /**
  59          * Executes the filter with given request and response objects
  60          *
  61          * @param       $requestInstance        An instance of a class with an Requestable interface
  62          * @param       $responseInstance       An instance of a class with an Responseable interface
  63          * @return      void
  64          * @throws      FilterChainException    If this filter fails to operate
  65          */
  66         public function execute (Requestable $requestInstance, Responseable $responseInstance) {
  67                 // Is the form set?
  68                 if (($requestInstance->getRequestElement('command') !== 'do_form') ||  (!$requestInstance->isRequestElementSet('form'))) {
  69                         // Required field not set
  70                         $requestInstance->requestIsValid(false);
  71
  72                         // Add fatal message
  73                         $responseInstance->addFatalMessage('command_form_invalid');
  74
  75                         // Skip further processing
  76                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
  77                 } // END - if
  78
  79                 // Create config entry
  80                 $configKey = sprintf('%s_captcha_secured',
  81                         $requestInstance->getRequestElement('form')
  82                 );
  83
  84                 // Is the CAPTCHA enabled?
  85                 if ($this->getConfigInstance()->getConfigEntry($configKey) != 'Y') {
  86                         // Not enabled, so don't check
  87                         return;
  88                 } // END - if
  89
  90                 // Get the captcha code
  91                 $captchaCode = $requestInstance->getRequestElement('c_code');
  92
  93                 // Is this set?
  94                 if (is_null($captchaCode)) {
  95                         // Not set so request is invalid
  96                         $requestInstance->requestIsValid(false);
  97
  98                         // Add fatal message
  99                         $responseInstance->addFatalMessage('captcha_code_unset');
 100
 101                         // Skip further processing
 102                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 103                 } elseif (empty($captchaCode)) {
 104                         // Empty value so request is invalid
 105                         $requestInstance->requestIsValid(false);
 106
 107                         // Add fatal message
 108                         $responseInstance->addFatalMessage('captcha_code_empty');
 109
 110                         // Skip further processing
 111                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 112                 }
 113
 114                 // Get the hash as well
 115                 $captchaHash = $requestInstance->getRequestElement('hash');
 116
 117                 // Is this set?
 118                 if (is_null($captchaHash)) {
 119                         // Not set so request is invalid
 120                         $requestInstance->requestIsValid(false);
 121
 122                         // Add fatal message
 123                         $responseInstance->addFatalMessage('captcha_hash_unset');
 124
 125                         // Skip further processing
 126                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 127                 } elseif (empty($captchaHash)) {
 128                         // Empty value so request is invalid
 129                         $requestInstance->requestIsValid(false);
 130
 131                         // Add fatal message
 132                         $responseInstance->addFatalMessage('captcha_hash_empty');
 133
 134                         // Skip further processing
 135                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 136                 }
 137
 138                 // Now, both are set hash the given one. First get a crypto instance
 139                 $cryptoInstance = ObjectFactory::createObjectByConfiguredName('crypto_class');
 140
 141                 // Then hash the code
 142                 $hashedCode = $cryptoInstance->hashString($captchaCode, $captchaHash);
 143
 144                 // Is this CAPTCHA valid?
 145                 if ($hashedCode != $captchaHash) {
 146                         // Not the same so request is invalid
 147                         $requestInstance->requestIsValid(false);
 148
 149                         // Add fatal message
 150                         $responseInstance->addFatalMessage('captcha_hash_mismatch');
 151
 152                         // Skip further processing
 153                         throw new FilterChainException($this, self::EXCEPTION_FILTER_CHAIN_INTERCEPTED);
 154                 } // END - not the same!
 155         }
 156
 157 }