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\Factory\ObjectFactory;
   7 use Org\Mxchange\CoreFramework\Generic\FrameworkInterface;
   8 use Org\Mxchange\CoreFramework\Helper\Template\HelpableTemplate;
   9
  10 /**
  11  * A solveable graphical code CAPTCHA
  12  *
  13  * @author              Roland Haeder <webmaster@shipsimu.org>
  14  * @version             0.0.0
  15  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2019 Core Developer Team
  16  * @license             GNU GPL 3.0 or any newer version
  17  * @link                http://www.shipsimu.org
  18  *
  19  * This program is free software: you can redistribute it and/or modify
  20  * it under the terms of the GNU General Public License as published by
  21  * the Free Software Foundation, either version 3 of the License, or
  22  * (at your option) any later version.
  23  *
  24  * This program is distributed in the hope that it will be useful,
  25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27  * GNU General Public License for more details.
  28  *
  29  * You should have received a copy of the GNU General Public License
  30  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  31  */
  32 class GraphicalCodeCaptcha extends BaseCaptcha implements SolveableCaptcha {
  33         /**
  34          * Hash of the CAPTCHA string
  35          */
  36         private $hashedString = '';
  37
  38         /**
  39          * Encrypted string
  40          */
  41         private $encryptedString = '';
  42
  43         /**
  44          * Protected constructor
  45          *
  46          * @return      void
  47          */
  48         protected function __construct () {
  49                 // Call parent constructor
  50                 parent::__construct(__CLASS__);
  51         }
  52
  53         /**
  54          * Creates an instance of this captcha class
  55          *
  56          * @param       $helperInstance         An instance of a helper class
  57          * @param       $extraInstance          An extra instance, just for better hash data
  58          * @return      $captchaInstance        An instance of this captcha class
  59          */
  60         public static final function createGraphicalCodeCaptcha (HelpableTemplate $helperInstance, FrameworkInterface $extraInstance = NULL) {
  61                 // Get a new instance
  62                 $captchaInstance = new GraphicalCodeCaptcha();
  63
  64                 // Set template instance
  65                 $captchaInstance->setHelperInstance($helperInstance);
  66
  67                 // Initialize the RNG
  68                 $captchaInstance->initializeRandomNumberGenerator($extraInstance);
  69
  70                 // Return the instance
  71                 return $captchaInstance;
  72         }
  73
  74         /**
  75          * Initiates the CAPTCHA
  76          *
  77          * @return      void
  78          */
  79         public function initiateCaptcha () {
  80                 // Get total length
  81                 $captchaLength = $this->getConfigInstance()->getConfigEntry('captcha_string_length');
  82
  83                 // Get max string length
  84                 $strLength = $this->getConfigInstance()->getConfigEntry('random_string_length');
  85
  86                 // Calculate starting position based on random place
  87                 $start = $this->getRngInstance()->randomNumber(0, ($strLength - $captchaLength));
  88
  89                 // Test it
  90                 assert($start >= 0);
  91
  92                 // Generate a random string for confirmation
  93                 $randomString = $this->getRngInstance()->randomString($strLength);
  94
  95                 // Encode the string with BASE64
  96                 $base64String = base64_encode($randomString);
  97
  98                 // Make this string a bit more readable for humans
  99                 $captchaString = substr($base64String, $start, $captchaLength);
 100
 101                 // Get all characters we want to replace
 102                 $searchChars = $this->getConfigInstance()->getConfigEntry('captcha_search_chars');
 103
 104                 // Get fixed salt and use it as "replacement characters"
 105                 $replaceChars = $this->getRngInstance()->getExtraSalt();
 106
 107                 // Remove any plus, equals or slashes
 108                 for ($searchIdx = 0; $searchIdx < strlen($searchChars); $searchIdx++) {
 109                         // Get search character
 110                         $search = substr($searchChars, $searchIdx, 1);
 111
 112                         // Random array index
 113                         $charIdx = $this->getRngInstance()->randomNumber(0, (strlen($replaceChars) - 1));
 114
 115                         // Get replacement
 116                         $replace = substr($replaceChars, $charIdx, 1);
 117
 118                         // Replace character
 119                         $captchaString = str_replace($search, $replace, $captchaString, $captchaLength);
 120                 } // END - foreach
 121
 122                 // Get crypto instance
 123                 $cryptoInstance = ObjectFactory::createObjectByConfiguredName('crypto_class');
 124
 125                 // Hash the CAPTCHA code for later comparison
 126                 $this->hashedString = $cryptoInstance->hashString($captchaString);
 127
 128                 // Encrypt the string for later usage
 129                 $this->encryptedString = $cryptoInstance->encryptString($captchaString);
 130         }
 131
 132         /**
 133          * Render the CAPTCHA code
 134          *
 135          * @return      void
 136          */
 137         public function renderCode () {
 138                 // Get helper instance
 139                 $helperInstance = $this->getHelperInstance();
 140
 141                 // Get template instance
 142                 $templateInstance = $helperInstance->getTemplateInstance();
 143
 144                 // Load a template for this CAPTCHA
 145                 $templateInstance->loadCodeTemplate('captch_graphic_code');
 146
 147                 // Rename variable
 148                 $templateInstance->renameVariable('captcha_code', $helperInstance->getFormName() . '_captcha');
 149                 $templateInstance->renameVariable('captcha_hash', $helperInstance->getFormName() . '_hash');
 150                 $templateInstance->renameVariable('encrypted_code', $helperInstance->getFormName() . '_encrypt');
 151
 152                 // Assign variables
 153                 $templateInstance->assignVariable($helperInstance->getFormName() . '_encrypt', urlencode(base64_encode($this->encryptedString)));
 154                 $templateInstance->assignVariable($helperInstance->getFormName() . '_hash', $this->hashedString);
 155
 156                 // Compile the template
 157                 $templateInstance->compileTemplate();
 158
 159                 // Get the content back
 160                 $this->addContent($templateInstance->getRawTemplateData());
 161         }
 162
 163 }