3 * A concrete filter for validating code graphical CAPTCHAs with hashes
5 * @author Roland Haeder <webmaster@ship-simu.org>
7 * @copyright Copyright (c) 2007, 2008 Roland Haeder, this is free software
8 * @license GNU GPL 3.0 or any newer version
9 * @link http://www.ship-simu.org
11 * This program is free software: you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation, either version 3 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program. If not, see <http://www.gnu.org/licenses/>.
24 class GraphicalCodeCaptchaVerifierFilter extends BaseFilter implements Filterable {
26 * Protected constructor
30 protected function __construct () {
31 // Call parent constructor
32 parent::__construct(__CLASS__);
36 * Creates an instance of this filter class
38 * @param $controllerInstance An instance of a Controller class
39 * @return $filterInstance An instance of this filter class
41 public final static function createGraphicalCodeCaptchaVerifierFilter (Controller $controllerInstance) {
43 $filterInstance = new GraphicalCodeCaptchaVerifierFilter();
46 $filterInstance->setControllerInstance($controllerInstance);
48 // Return the instance
49 return $filterInstance;
53 * Executes the filter with given request and response objects
55 * @param $requestInstance An instance of a class with an Requestable interface
56 * @param $responseInstance An instance of a class with an Responseable interface
59 public function execute (Requestable $requestInstance, Responseable $responseInstance) {
60 // Get the captcha code
61 $captchaCode = $requestInstance->getRequestElement('c_code');
64 if (is_null($captchaCode)) {
65 // Not set so request is invalid
66 $requestInstance->requestIsValid(false);
69 $responseInstance->addFatalMessage('captcha_code_unset');
71 // Skip further processing
73 } elseif (empty($captchaCode)) {
74 // Empty value so request is invalid
75 $requestInstance->requestIsValid(false);
78 $responseInstance->addFatalMessage('captcha_code_empty');
80 // Skip further processing
84 // Get the hash as well
85 $captchaHash = $requestInstance->getRequestElement('hash');
88 if (is_null($captchaHash)) {
89 // Not set so request is invalid
90 $requestInstance->requestIsValid(false);
93 $responseInstance->addFatalMessage('captcha_hash_unset');
95 // Skip further processing
97 } elseif (empty($captchaHash)) {
98 // Empty value so request is invalid
99 $requestInstance->requestIsValid(false);
102 $responseInstance->addFatalMessage('captcha_hash_empty');
104 // Skip further processing
108 // Now, both are set hash the given one. First get a crypto instance
109 $cryptoInstance = ObjectFactory::createObjectByConfiguredName('crypto_class');
111 // Then hash the code
112 $hashedCode = $cryptoInstance->hashString($captchaCode, $captchaHash);
114 // Is this CAPTCHA valid?
115 if ($hashedCode != $captchaHash) {
116 // Not the same so request is invalid
117 $requestInstance->requestIsValid(false);
120 $responseInstance->addFatalMessage('captcha_hash_mismatch');
121 } // END - not the same!