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authorbrettp <brettp@36083f99-b078-4883-b0ff-0f9b5a30f544>2010-03-03 17:53:05 +0000
committerbrettp <brettp@36083f99-b078-4883-b0ff-0f9b5a30f544>2010-03-03 17:53:05 +0000
commit4766f36a4d74924f21ff329c4318ce4e069ffa04 (patch)
tree969b84632f2a8b0db79788a8a6db8e41d63e5cb4 /mod/captcha/start.php
parent57a217fd6b708844407486046a1faa23b46cac08 (diff)
downloadelgg-4766f36a4d74924f21ff329c4318ce4e069ffa04.tar.gz
elgg-4766f36a4d74924f21ff329c4318ce4e069ffa04.tar.bz2
Pulled in the interface changes.
git-svn-id: http://code.elgg.org/elgg/trunk@5257 36083f99-b078-4883-b0ff-0f9b5a30f544
Diffstat (limited to 'mod/captcha/start.php')
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diff --git a/mod/captcha/start.php b/mod/captcha/start.php
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+<?php
+ /**
+ * Elgg captcha plugin
+ *
+ * @package ElggCaptcha
+ * @license http://www.gnu.org/licenses/old-licenses/gpl-2.0.html GNU Public License version 2
+ * @author Curverider Ltd
+ * @copyright Curverider Ltd 2008-2010
+ * @link http://elgg.com/
+ */
+
+ function captcha_init()
+ {
+ global $CONFIG;
+
+ // Register page handler for captcha functionality
+ register_page_handler('captcha','captcha_page_handler');
+
+ // Extend CSS
+ elgg_extend_view('css','captcha/css');
+
+ // Number of background images
+ $CONFIG->captcha_num_bg = 5;
+
+ // Default length
+ $CONFIG->captcha_length = 5;
+
+ // Register a function that provides some default override actions
+ register_plugin_hook('actionlist', 'captcha', 'captcha_actionlist_hook');
+
+ // Register actions to intercept
+ $actions = array();
+ $actions = trigger_plugin_hook('actionlist', 'captcha', null, $actions);
+
+ if (($actions) && (is_array($actions)))
+ {
+ foreach ($actions as $action)
+ register_plugin_hook("action", $action, "captcha_verify_action_hook");
+ }
+ }
+
+ function captcha_page_handler($page)
+ {
+ global $CONFIG;
+
+ if (isset($page[0])) {
+ set_input('captcha_token',$page[0]);
+ }
+
+ include($CONFIG->pluginspath . "captcha/captcha.php");
+ }
+
+ /**
+ * Generate a token to act as a seed value for the captcha algorithm.
+ */
+ function captcha_generate_token()
+ {
+ return md5(generate_action_token(time()).rand()); // Use action token plus some random for uniqueness
+ }
+
+ /**
+ * Generate a captcha based on the given seed value and length.
+ *
+ * @param string $seed_token
+ * @return string
+ */
+ function captcha_generate_captcha($seed_token)
+ {
+ global $CONFIG;
+
+ /*
+ * We generate a token out of the random seed value + some session data,
+ * this means that solving via pr0n site or indian cube farm becomes
+ * significantly more tricky (we hope).
+ *
+ * We also add the site secret, which is unavailable to the client and so should
+ * make it very very hard to guess values before hand.
+ *
+ */
+
+ return strtolower(substr(md5(generate_action_token(0) . $seed_token), 0, $CONFIG->captcha_length));
+ }
+
+ /**
+ * Verify a captcha based on the input value entered by the user and the seed token passed.
+ *
+ * @param string $input_value
+ * @param string $seed_token
+ * @return bool
+ */
+ function captcha_verify_captcha($input_value, $seed_token)
+ {
+ if (strcasecmp($input_value, captcha_generate_captcha($seed_token)) == 0)
+ return true;
+
+ return false;
+ }
+
+ /**
+ * Listen to the action plugin hook and check the captcha.
+ *
+ * @param unknown_type $hook
+ * @param unknown_type $entity_type
+ * @param unknown_type $returnvalue
+ * @param unknown_type $params
+ */
+ function captcha_verify_action_hook($hook, $entity_type, $returnvalue, $params)
+ {
+ $token = get_input('captcha_token');
+ $input = get_input('captcha_input');
+
+ if (($token) && (captcha_verify_captcha($input, $token)))
+ return true;
+
+ register_error(elgg_echo('captcha:captchafail'));
+
+ return false;
+ }
+
+ /**
+ * This function returns an array of actions the captcha will expect a captcha for, other plugins may
+ * add their own to this list thereby extending the use.
+ *
+ * @param unknown_type $hook
+ * @param unknown_type $entity_type
+ * @param unknown_type $returnvalue
+ * @param unknown_type $params
+ */
+ function captcha_actionlist_hook($hook, $entity_type, $returnvalue, $params)
+ {
+ if (!is_array($returnvalue))
+ $returnvalue = array();
+
+ $returnvalue[] = 'register';
+ $returnvalue[] = 'user/requestnewpassword';
+
+ return $returnvalue;
+ }
+
+ register_elgg_event_handler('init','system','captcha_init');
+?> \ No newline at end of file