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\Crypto\CryptoHelper;
  10 use Org\Mxchange\CoreFramework\Helper\Template\HelpableTemplate;
  11
  12 /**
  13  * A solveable graphical code CAPTCHA
  14  *
  15  * @author              Roland Haeder <webmaster@shipsimu.org>
  16  * @version             0.0.0
  17  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2023 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 GraphicalCodeCaptcha extends BaseCaptcha implements SolveableCaptcha {
  35         /**
  36          * Hash of the CAPTCHA string
  37          */
  38         private $hashedString = '';
  39
  40         /**
  41          * Encrypted string
  42          */
  43         private $encryptedString = '';
  44
  45         /**
  46          * Protected constructor
  47          *
  48          * @return      void
  49          */
  50         private function __construct () {
  51                 // Call parent constructor
  52                 parent::__construct(__CLASS__);
  53         }
  54
  55         /**
  56          * Creates an instance of this captcha class
  57          *
  58          * @param       $helperInstance         An instance of a helper class
  59          * @param       $extraInstance          An extra instance, just for better hash data
  60          * @return      $captchaInstance        An instance of this captcha class
  61          */
  62         public static final function createGraphicalCodeCaptcha (HelpableTemplate $helperInstance, FrameworkInterface $extraInstance = NULL) {
  63                 // Get a new instance
  64                 $captchaInstance = new GraphicalCodeCaptcha();
  65
  66                 // Set template instance
  67                 $captchaInstance->setHelperInstance($helperInstance);
  68
  69                 // Initialize the RNG
  70                 $captchaInstance->initializeRandomNumberGenerator($extraInstance);
  71
  72                 // Return the instance
  73                 return $captchaInstance;
  74         }
  75
  76         /**
  77          * Initiates the CAPTCHA
  78          *
  79          * @return      void
  80          */
  81         public function initiateCaptcha () {
  82                 // Get total length
  83                 $captchaLength = FrameworkBootstrap::getConfigurationInstance()->getConfigEntry('captcha_string_length');
  84
  85                 // Get max string length
  86                 $strLength = FrameworkBootstrap::getConfigurationInstance()->getConfigEntry('random_string_length');
  87
  88                 // Calculate starting position based on random place
  89                 $start = $this->getRngInstance()->randomNumber(0, ($strLength - $captchaLength));
  90
  91                 // Test it
  92                 assert($start >= 0);
  93
  94                 // Generate a random string for confirmation
  95                 $randomString = $this->getRngInstance()->randomString($strLength);
  96
  97                 // Encode the string with BASE64
  98                 $base64String = base64_encode($randomString);
  99
 100                 // Make this string a bit more readable for humans
 101                 $captchaString = substr($base64String, $start, $captchaLength);
 102
 103                 // Get all characters we want to replace
 104                 $searchChars = FrameworkBootstrap::getConfigurationInstance()->getConfigEntry('captcha_search_chars');
 105
 106                 // Get fixed salt and use it as "replacement characters"
 107                 $replaceChars = $this->getRngInstance()->getExtraSalt();
 108
 109                 // Remove any plus, equals or slashes
 110                 for ($searchIdx = 0; $searchIdx < strlen($searchChars); $searchIdx++) {
 111                         // Get search character
 112                         $search = substr($searchChars, $searchIdx, 1);
 113
 114                         // Random array index
 115                         $charIdx = $this->getRngInstance()->randomNumber(0, (strlen($replaceChars) - 1));
 116
 117                         // Get replacement
 118                         $replace = substr($replaceChars, $charIdx, 1);
 119
 120                         // Replace character
 121                         $captchaString = str_replace($search, $replace, $captchaString, $captchaLength);
 122                 }
 123
 124                 // Get crypto instance
 125                 $cryptoInstance = CryptoHelper::getSelfInstance();
 126
 127                 // Hash the CAPTCHA code for later comparison
 128                 $this->hashedString = $cryptoInstance->hashString($captchaString);
 129
 130                 // Encrypt the string for later usage
 131                 $this->encryptedString = $cryptoInstance->encryptString($captchaString);
 132         }
 133
 134         /**
 135          * Render the CAPTCHA code
 136          *
 137          * @return      void
 138          */
 139         public function renderCode () {
 140                 // Get helper instance
 141                 $helperInstance = $this->getHelperInstance();
 142
 143                 // Get template instance
 144                 $templateInstance = $helperInstance->getTemplateInstance();
 145
 146                 // Load a template for this CAPTCHA
 147                 $templateInstance->loadCodeTemplate('captch_graphic_code');
 148
 149                 // Rename variable
 150                 $templateInstance->renameVariable('captcha_code', $helperInstance->getFormName() . '_captcha');
 151                 $templateInstance->renameVariable('captcha_hash', $helperInstance->getFormName() . '_hash');
 152                 $templateInstance->renameVariable('encrypted_code', $helperInstance->getFormName() . '_encrypt');
 153
 154                 // Assign variables
 155                 $templateInstance->assignVariable($helperInstance->getFormName() . '_encrypt', urlencode(base64_encode($this->encryptedString)));
 156                 $templateInstance->assignVariable($helperInstance->getFormName() . '_hash', $this->hashedString);
 157
 158                 // Compile the template
 159                 $templateInstance->compileTemplate();
 160
 161                 // Get the content back
 162                 $this->addContent($templateInstance->getRawTemplateData());
 163         }
 164
 165 }