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, 2009 - 2012 Core Developer Team
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 * @return $filterInstance An instance of this filter class
40 public static final function createGraphicalCodeCaptchaVerifierFilter () {
42 $filterInstance = new GraphicalCodeCaptchaVerifierFilter();
44 // Return the instance
45 return $filterInstance;
49 * Executes the filter with given request and response objects
51 * @param $requestInstance An instance of a class with an Requestable interface
52 * @param $responseInstance An instance of a class with an Responseable interface
55 public function execute (Requestable $requestInstance, Responseable $responseInstance) {
56 // Get the captcha code
57 $captchaCode = $requestInstance->getRequestElement('c_code');
60 if (is_null($captchaCode)) {
61 // Not set so request is invalid
62 $requestInstance->requestIsValid(false);
65 $responseInstance->addFatalMessage('captcha_code_unset');
67 // Skip further processing
69 } elseif (empty($captchaCode)) {
70 // Empty value so request is invalid
71 $requestInstance->requestIsValid(false);
74 $responseInstance->addFatalMessage('captcha_code_empty');
76 // Skip further processing
80 // Get the hash as well
81 $captchaHash = $requestInstance->getRequestElement('hash');
84 if (is_null($captchaHash)) {
85 // Not set so request is invalid
86 $requestInstance->requestIsValid(false);
89 $responseInstance->addFatalMessage('captcha_hash_unset');
91 // Skip further processing
93 } elseif (empty($captchaHash)) {
94 // Empty value so request is invalid
95 $requestInstance->requestIsValid(false);
98 $responseInstance->addFatalMessage('captcha_hash_empty');
100 // Skip further processing
104 // Now, both are set hash the given one. First get a crypto instance
105 $cryptoInstance = ObjectFactory::createObjectByConfiguredName('crypto_class');
107 // Then hash the code
108 $hashedCode = $cryptoInstance->hashString($captchaCode, $captchaHash);
110 // Is this CAPTCHA valid?
111 if ($hashedCode != $captchaHash) {
112 // Not the same so request is invalid
113 $requestInstance->requestIsValid(false);
116 $responseInstance->addFatalMessage('captcha_hash_mismatch');
117 } // END - not the same!