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

   1 <?php
   2 // Own namespace
   3 namespace CoreFramework\Captcha;
   4
   5 // Import framework stuff
   6 use CoreFramework\Factory\ObjectFactory;
   7 use CoreFramework\Generic\FrameworkInterface;
   8
   9 /**
  10  * A solveable graphical code CAPTCHA
  11  *
  12  * @author              Roland Haeder <webmaster@shipsimu.org>
  13  * @version             0.0.0
  14  * @copyright   Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2017 Core Developer Team
  15  * @license             GNU GPL 3.0 or any newer version
  16  * @link                http://www.shipsimu.org
  17  *
  18  * This program is free software: you can redistribute it and/or modify
  19  * it under the terms of the GNU General Public License as published by
  20  * the Free Software Foundation, either version 3 of the License, or
  21  * (at your option) any later version.
  22  *
  23  * This program is distributed in the hope that it will be useful,
  24  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  * GNU General Public License for more details.
  27  *
  28  * You should have received a copy of the GNU General Public License
  29  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  30  */
  31 class GraphicalCodeCaptcha extends BaseCaptcha implements SolveableCaptcha {
  32         /**
  33          * Hash of the CAPTCHA string
  34          */
  35         private $hashedString = '';
  36
  37         /**
  38          * Encrypted string
  39          */
  40         private $encryptedString = '';
  41
  42         /**
  43          * Protected constructor
  44          *
  45          * @return      void
  46          */
  47         protected function __construct () {
  48                 // Call parent constructor
  49                 parent::__construct(__CLASS__);
  50         }
  51
  52         /**
  53          * Creates an instance of this captcha class
  54          *
  55          * @param       $helperInstance         An instance of a helper class
  56          * @param       $extraInstance          An extra instance, just for better hash data
  57          * @return      $captchaInstance        An instance of this captcha class
  58          */
  59         public static final function createGraphicalCodeCaptcha (HelpableTemplate $helperInstance, FrameworkInterface $extraInstance = NULL) {
  60                 // Get a new instance
  61                 $captchaInstance = new GraphicalCodeCaptcha();
  62
  63                 // Set template instance
  64                 $captchaInstance->setHelperInstance($helperInstance);
  65
  66                 // Initialize the RNG
  67                 $captchaInstance->initializeRandomNumberGenerator($extraInstance);
  68
  69                 // Return the instance
  70                 return $captchaInstance;
  71         }
  72
  73         /**
  74          * Initiates the CAPTCHA
  75          *
  76          * @return      void
  77          */
  78         public function initiateCaptcha () {
  79                 // Get total length
  80                 $captchaLength = $this->getConfigInstance()->getConfigEntry('captcha_string_length');
  81
  82                 // Get max string length
  83                 $strLength = $this->getConfigInstance()->getConfigEntry('random_string_length');
  84
  85                 // Calculate starting position based on random place
  86                 $start = $this->getRngInstance()->randomNumber(0, ($strLength - $captchaLength));
  87
  88                 // Test it
  89                 assert($start >= 0);
  90
  91                 // Generate a random string for confirmation
  92                 $randomString = $this->getRngInstance()->randomString($strLength);
  93
  94                 // Encode the string with BASE64
  95                 $base64String = base64_encode($randomString);
  96
  97                 // Make this string a bit more readable for humans
  98                 $captchaString = substr($base64String, $start, $captchaLength);
  99
 100                 // Get all characters we want to replace
 101                 $searchChars = $this->getConfigInstance()->getConfigEntry('captcha_search_chars');
 102
 103                 // Get fixed salt and use it as "replacement characters"
 104                 $replaceChars = $this->getRngInstance()->getExtraSalt();
 105
 106                 // Remove any plus, equals or slashes
 107                 for ($searchIdx = 0; $searchIdx < strlen($searchChars); $searchIdx++) {
 108                         // Get search character
 109                         $search = substr($searchChars, $searchIdx, 1);
 110
 111                         // Random array index
 112                         $charIdx = $this->getRngInstance()->randomNumber(0, (strlen($replaceChars) - 1));
 113
 114                         // Get replacement
 115                         $replace = substr($replaceChars, $charIdx, 1);
 116
 117                         // Replace character
 118                         $captchaString = str_replace($search, $replace, $captchaString, $captchaLength);
 119                 } // END - foreach
 120
 121                 // Get crypto instance
 122                 $cryptoInstance = ObjectFactory::createObjectByConfiguredName('crypto_class');
 123
 124                 // Hash the CAPTCHA code for later comparison
 125                 $this->hashedString = $cryptoInstance->hashString($captchaString);
 126
 127                 // Encrypt the string for later usage
 128                 $this->encryptedString = $cryptoInstance->encryptString($captchaString);
 129         }
 130
 131         /**
 132          * Render the CAPTCHA code
 133          *
 134          * @return      void
 135          */
 136         public function renderCode () {
 137                 // Get helper instance
 138                 $helperInstance = $this->getHelperInstance();
 139
 140                 // Get template instance
 141                 $templateInstance = $helperInstance->getTemplateInstance();
 142
 143                 // Load a template for this CAPTCHA
 144                 $templateInstance->loadCodeTemplate('captch_graphic_code');
 145
 146                 // Rename variable
 147                 $templateInstance->renameVariable('captcha_code', $helperInstance->getFormName() . '_captcha');
 148                 $templateInstance->renameVariable('captcha_hash', $helperInstance->getFormName() . '_hash');
 149                 $templateInstance->renameVariable('encrypted_code', $helperInstance->getFormName() . '_encrypt');
 150
 151                 // Assign variables
 152                 $templateInstance->assignVariable($helperInstance->getFormName() . '_encrypt', urlencode(base64_encode($this->encryptedString)));
 153                 $templateInstance->assignVariable($helperInstance->getFormName() . '_hash', $this->hashedString);
 154
 155                 // Compile the template
 156                 $templateInstance->compileTemplate();
 157
 158                 // Get the content back
 159                 $this->addContent($templateInstance->getRawTemplateData());
 160         }
 161
 162 }