framework/main/classes/helper/captcha/web/class_GraphicalCodeCaptcha.php

   1 <?php
   2 // Own namespace
   3 namespace Org\Mxchange\CoreFramework\Helper\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\Generic\FrameworkInterface;
   9 use Org\Mxchange\CoreFramework\Helper\Template\HelpableTemplate;
  10
  11 /**
  12  * A solveable graphical code CAPTCHA
  13  *
  14  * @author              Roland Haeder <webmaster@shipsimu.org>
  15  * @version             0.0.0
  16  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2023 Core Developer Team
  17  * @license             GNU GPL 3.0 or any newer version
  18  * @link                http://www.shipsimu.org
  19  *
  20  * This program is free software: you can redistribute it and/or modify
  21  * it under the terms of the GNU General Public License as published by
  22  * the Free Software Foundation, either version 3 of the License, or
  23  * (at your option) any later version.
  24  *
  25  * This program is distributed in the hope that it will be useful,
  26  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  27  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  28  * GNU General Public License for more details.
  29  *
  30  * You should have received a copy of the GNU General Public License
  31  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  32  */
  33 class GraphicalCodeCaptcha extends BaseCaptcha implements SolveableCaptcha {
  34         /**
  35          * Hash of the CAPTCHA string
  36          */
  37         private $hashedString = '';
  38
  39         /**
  40          * Encrypted string
  41          */
  42         private $encryptedString = '';
  43
  44         /**
  45          * Protected constructor
  46          *
  47          * @return      void
  48          */
  49         private function __construct () {
  50                 // Call parent constructor
  51                 parent::__construct(__CLASS__);
  52         }
  53
  54         /**
  55          * Creates an instance of this captcha class
  56          *
  57          * @param       $helperInstance         An instance of a helper class
  58          * @param       $extraInstance          An extra instance, just for better hash data
  59          * @return      $captchaInstance        An instance of this captcha class
  60          */
  61         public static final function createGraphicalCodeCaptcha (HelpableTemplate $helperInstance, FrameworkInterface $extraInstance = NULL) {
  62                 // Get a new instance
  63                 $captchaInstance = new GraphicalCodeCaptcha();
  64
  65                 // Set template instance
  66                 $captchaInstance->setHelperInstance($helperInstance);
  67
  68                 // Initialize the RNG
  69                 $captchaInstance->initializeRandomNumberGenerator($extraInstance);
  70
  71                 // Return the instance
  72                 return $captchaInstance;
  73         }
  74
  75         /**
  76          * Initiates the CAPTCHA
  77          *
  78          * @return      void
  79          */
  80         public function initiateCaptcha () {
  81                 // Get total length
  82                 $captchaLength = FrameworkBootstrap::getConfigurationInstance()->getConfigEntry('captcha_string_length');
  83
  84                 // Get max string length
  85                 $strLength = FrameworkBootstrap::getConfigurationInstance()->getConfigEntry('random_string_length');
  86
  87                 // Calculate starting position based on random place
  88                 $start = $this->getRngInstance()->randomNumber(0, ($strLength - $captchaLength));
  89
  90                 // Test it
  91                 assert($start >= 0);
  92
  93                 // Generate a random string for confirmation
  94                 $randomString = $this->getRngInstance()->randomString($strLength);
  95
  96                 // Encode the string with BASE64
  97                 $base64String = base64_encode($randomString);
  98
  99                 // Make this string a bit more readable for humans
 100                 $captchaString = substr($base64String, $start, $captchaLength);
 101
 102                 // Get all characters we want to replace
 103                 $searchChars = FrameworkBootstrap::getConfigurationInstance()->getConfigEntry('captcha_search_chars');
 104
 105                 // Get fixed salt and use it as "replacement characters"
 106                 $replaceChars = $this->getRngInstance()->getExtraSalt();
 107
 108                 // Remove any plus, equals or slashes
 109                 for ($searchIdx = 0; $searchIdx < strlen($searchChars); $searchIdx++) {
 110                         // Get search character
 111                         $search = substr($searchChars, $searchIdx, 1);
 112
 113                         // Random array index
 114                         $charIdx = $this->getRngInstance()->randomNumber(0, (strlen($replaceChars) - 1));
 115
 116                         // Get replacement
 117                         $replace = substr($replaceChars, $charIdx, 1);
 118
 119                         // Replace character
 120                         $captchaString = str_replace($search, $replace, $captchaString, $captchaLength);
 121                 }
 122
 123                 // Get crypto instance
 124                 $cryptoInstance = ObjectFactory::createObjectByConfiguredName('crypto_class');
 125
 126                 // Hash the CAPTCHA code for later comparison
 127                 $this->hashedString = $cryptoInstance->hashString($captchaString);
 128
 129                 // Encrypt the string for later usage
 130                 $this->encryptedString = $cryptoInstance->encryptString($captchaString);
 131         }
 132
 133         /**
 134          * Render the CAPTCHA code
 135          *
 136          * @return      void
 137          */
 138         public function renderCode () {
 139                 // Get helper instance
 140                 $helperInstance = $this->getHelperInstance();
 141
 142                 // Get template instance
 143                 $templateInstance = $helperInstance->getTemplateInstance();
 144
 145                 // Load a template for this CAPTCHA
 146                 $templateInstance->loadCodeTemplate('captch_graphic_code');
 147
 148                 // Rename variable
 149                 $templateInstance->renameVariable('captcha_code', $helperInstance->getFormName() . '_captcha');
 150                 $templateInstance->renameVariable('captcha_hash', $helperInstance->getFormName() . '_hash');
 151                 $templateInstance->renameVariable('encrypted_code', $helperInstance->getFormName() . '_encrypt');
 152
 153                 // Assign variables
 154                 $templateInstance->assignVariable($helperInstance->getFormName() . '_encrypt', urlencode(base64_encode($this->encryptedString)));
 155                 $templateInstance->assignVariable($helperInstance->getFormName() . '_hash', $this->hashedString);
 156
 157                 // Compile the template
 158                 $templateInstance->compileTemplate();
 159
 160                 // Get the content back
 161                 $this->addContent($templateInstance->getRawTemplateData());
 162         }
 163
 164 }