diff options
Diffstat (limited to 'kohana/libraries/Captcha.php')
| -rw-r--r-- | kohana/libraries/Captcha.php | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/kohana/libraries/Captcha.php b/kohana/libraries/Captcha.php new file mode 100644 index 00000000..bac4e132 --- /dev/null +++ b/kohana/libraries/Captcha.php @@ -0,0 +1,279 @@ +<?php defined('SYSPATH') or die('No direct script access.'); +/** + * Captcha library. + * + * $Id$ + * + * @package Captcha + * @author Kohana Team + * @copyright (c) 2007-2008 Kohana Team + * @license http://kohanaphp.com/license.html + */ +class Captcha_Core { + + // Captcha singleton + protected static $instance; + + // Style-dependent Captcha driver + protected $driver; + + // Config values + public static $config = array + ( + 'style' => 'basic', + 'width' => 150, + 'height' => 50, + 'complexity' => 4, + 'background' => '', + 'fontpath' => '', + 'fonts' => array(), + 'promote' => FALSE, + ); + + /** + * Singleton instance of Captcha. + * + * @return object + */ + public static function instance() + { + // Create the instance if it does not exist + empty(self::$instance) and new Captcha; + + return self::$instance; + } + + /** + * Constructs and returns a new Captcha object. + * + * @param string config group name + * @return object + */ + public function factory($group = NULL) + { + return new Captcha($group); + } + + /** + * Constructs a new Captcha object. + * + * @throws Kohana_Exception + * @param string config group name + * @return void + */ + public function __construct($group = NULL) + { + // Create a singleton instance once + empty(self::$instance) and self::$instance = $this; + + // No config group name given + if ( ! is_string($group)) + { + $group = 'default'; + } + + // Load and validate config group + if ( ! is_array($config = Kohana::config('captcha.'.$group))) + throw new Kohana_Exception('captcha.undefined_group', $group); + + // All captcha config groups inherit default config group + if ($group !== 'default') + { + // Load and validate default config group + if ( ! is_array($default = Kohana::config('captcha.default'))) + throw new Kohana_Exception('captcha.undefined_group', 'default'); + + // Merge config group with default config group + $config += $default; + } + + // Assign config values to the object + foreach ($config as $key => $value) + { + if (array_key_exists($key, self::$config)) + { + self::$config[$key] = $value; + } + } + + // Store the config group name as well, so the drivers can access it + self::$config['group'] = $group; + + // If using a background image, check if it exists + if ( ! empty($config['background'])) + { + self::$config['background'] = str_replace('\\', '/', realpath($config['background'])); + + if ( ! is_file(self::$config['background'])) + throw new Kohana_Exception('captcha.file_not_found', self::$config['background']); + } + + // If using any fonts, check if they exist + if ( ! empty($config['fonts'])) + { + self::$config['fontpath'] = str_replace('\\', '/', realpath($config['fontpath'])).'/'; + + foreach ($config['fonts'] as $font) + { + if ( ! is_file(self::$config['fontpath'].$font)) + throw new Kohana_Exception('captcha.file_not_found', self::$config['fontpath'].$font); + } + } + + // Set driver name + $driver = 'Captcha_'.ucfirst($config['style']).'_Driver'; + + // Load the driver + if ( ! Kohana::auto_load($driver)) + throw new Kohana_Exception('core.driver_not_found', $config['style'], get_class($this)); + + // Initialize the driver + $this->driver = new $driver; + + // Validate the driver + if ( ! ($this->driver instanceof Captcha_Driver)) + throw new Kohana_Exception('core.driver_implements', $config['style'], get_class($this), 'Captcha_Driver'); + + Kohana::log('debug', 'Captcha Library initialized'); + } + + /** + * Validates a Captcha response and updates response counter. + * + * @param string captcha response + * @return boolean + */ + public static function valid($response) + { + // Maximum one count per page load + static $counted; + + // User has been promoted, always TRUE and don't count anymore + if (self::instance()->promoted()) + return TRUE; + + // Challenge result + $result = (bool) self::instance()->driver->valid($response); + + // Increment response counter + if ($counted !== TRUE) + { + $counted = TRUE; + + // Valid response + if ($result === TRUE) + { + self::instance()->valid_count(Session::instance()->get('captcha_valid_count') + 1); + } + // Invalid response + else + { + self::instance()->invalid_count(Session::instance()->get('captcha_invalid_count') + 1); + } + } + + return $result; + } + + /** + * Gets or sets the number of valid Captcha responses for this session. + * + * @param integer new counter value + * @param boolean trigger invalid counter (for internal use only) + * @return integer counter value + */ + public function valid_count($new_count = NULL, $invalid = FALSE) + { + // Pick the right session to use + $session = ($invalid === TRUE) ? 'captcha_invalid_count' : 'captcha_valid_count'; + + // Update counter + if ($new_count !== NULL) + { + $new_count = (int) $new_count; + + // Reset counter = delete session + if ($new_count < 1) + { + Session::instance()->delete($session); + } + // Set counter to new value + else + { + Session::instance()->set($session, (int) $new_count); + } + + // Return new count + return (int) $new_count; + } + + // Return current count + return (int) Session::instance()->get($session); + } + + /** + * Gets or sets the number of invalid Captcha responses for this session. + * + * @param integer new counter value + * @return integer counter value + */ + public function invalid_count($new_count = NULL) + { + return $this->valid_count($new_count, TRUE); + } + + /** + * Resets the Captcha response counters and removes the count sessions. + * + * @return void + */ + public function reset_count() + { + $this->valid_count(0); + $this->valid_count(0, TRUE); + } + + /** + * Checks whether user has been promoted after having given enough valid responses. + * + * @param integer valid response count threshold + * @return boolean + */ + public function promoted($threshold = NULL) + { + // Promotion has been disabled + if (self::$config['promote'] === FALSE) + return FALSE; + + // Use the config threshold + if ($threshold === NULL) + { + $threshold = self::$config['promote']; + } + + // Compare the valid response count to the threshold + return ($this->valid_count() >= $threshold); + } + + /** + * Returns or outputs the Captcha challenge. + * + * @param boolean TRUE to output html, e.g. <img src="#" /> + * @return mixed html string or void + */ + public function render($html = TRUE) + { + return $this->driver->render($html); + } + + /** + * Magically outputs the Captcha challenge. + * + * @return mixed + */ + public function __toString() + { + return $this->render(); + } + +} // End Captcha Class
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