Rename 'kohana' to 'system' to conform to the Kohana filesystem layout. I'm comfortable with us not clearly drawing the distinction about the fact that it's Kohana.

1 files changed, 227 insertions, 0 deletions

diff --git a/system/libraries/drivers/Captcha.php b/system/libraries/drivers/Captcha.php
new file mode 100644
index 00000000..a4343e19
--- /dev/null
+++ b/system/libraries/drivers/Captcha.php
@@ -0,0 +1,227 @@
+<?php defined('SYSPATH') OR die('No direct access allowed.');
+/**
+ * Captcha driver class.
+ *
+ * $Id: Captcha.php 3769 2008-12-15 00:48:56Z zombor $
+ *
+ * @package    Captcha
+ * @author     Kohana Team
+ * @copyright  (c) 2007-2008 Kohana Team
+ * @license    http://kohanaphp.com/license.html
+ */
+abstract class Captcha_Driver {
+
+	// The correct Captcha challenge answer
+	protected $response;
+
+	// Image resource identifier and type ("png", "gif" or "jpeg")
+	protected $image;
+	protected $image_type = 'png';
+
+	/**
+	 * Constructs a new challenge.
+	 *
+	 * @return  void
+	 */
+	public function __construct()
+	{
+		// Generate a new challenge
+		$this->response = $this->generate_challenge();
+
+		// Store the correct Captcha response in a session
+		Event::add('system.post_controller', array($this, 'update_response_session'));
+	}
+
+	/**
+	 * Generate a new Captcha challenge.
+	 *
+	 * @return  string  the challenge answer
+	 */
+	abstract public function generate_challenge();
+
+	/**
+	 * Output the Captcha challenge.
+	 *
+	 * @param   boolean  html output
+	 * @return  mixed    the rendered Captcha (e.g. an image, riddle, etc.)
+	 */
+	abstract public function render($html);
+
+	/**
+	 * Stores the response for the current Captcha challenge in a session so it is available
+	 * on the next page load for Captcha::valid(). This method is called after controller
+	 * execution (in the system.post_controller event) in order not to overwrite itself too soon.
+	 *
+	 * @return  void
+	 */
+	public function update_response_session()
+	{
+		Session::instance()->set('captcha_response', sha1(strtoupper($this->response)));
+	}
+
+	/**
+	 * Validates a Captcha response from a user.
+	 *
+	 * @param   string   captcha response
+	 * @return  boolean
+	 */
+	public function valid($response)
+	{
+		return (sha1(strtoupper($response)) === Session::instance()->get('captcha_response'));
+	}
+
+	/**
+	 * Returns the image type.
+	 *
+	 * @param   string        filename
+	 * @return  string|FALSE  image type ("png", "gif" or "jpeg")
+	 */
+	public function image_type($filename)
+	{
+		switch (strtolower(substr(strrchr($filename, '.'), 1)))
+		{
+			case 'png':
+				return 'png';
+
+			case 'gif':
+				return 'gif';
+
+			case 'jpg':
+			case 'jpeg':
+				// Return "jpeg" and not "jpg" because of the GD2 function names
+				return 'jpeg';
+
+			default:
+				return FALSE;
+		}
+	}
+
+	/**
+	 * Creates an image resource with the dimensions specified in config.
+	 * If a background image is supplied, the image dimensions are used.
+	 *
+	 * @throws  Kohana_Exception  if no GD2 support
+	 * @param   string  path to the background image file
+	 * @return  void
+	 */
+	public function image_create($background = NULL)
+	{
+		// Check for GD2 support
+		if ( ! function_exists('imagegd2'))
+			throw new Kohana_Exception('captcha.requires_GD2');
+
+		// Create a new image (black)
+		$this->image = imagecreatetruecolor(Captcha::$config['width'], Captcha::$config['height']);
+
+		// Use a background image
+		if ( ! empty($background))
+		{
+			// Create the image using the right function for the filetype
+			$function = 'imagecreatefrom'.$this->image_type($background);
+			$this->background_image = $function($background);
+
+			// Resize the image if needed
+			if (imagesx($this->background_image) !== Captcha::$config['width']
+			    OR imagesy($this->background_image) !== Captcha::$config['height'])
+			{
+				imagecopyresampled
+				(
+					$this->image, $this->background_image, 0, 0, 0, 0,
+					Captcha::$config['width'], Captcha::$config['height'],
+					imagesx($this->background_image), imagesy($this->background_image)
+				);
+			}
+
+			// Free up resources
+			imagedestroy($this->background_image);
+		}
+	}
+
+	/**
+	 * Fills the background with a gradient.
+	 *
+	 * @param   resource  gd image color identifier for start color
+	 * @param   resource  gd image color identifier for end color
+	 * @param   string    direction: 'horizontal' or 'vertical', 'random' by default
+	 * @return  void
+	 */
+	public function image_gradient($color1, $color2, $direction = NULL)
+	{
+		$directions = array('horizontal', 'vertical');
+
+		// Pick a random direction if needed
+		if ( ! in_array($direction, $directions))
+		{
+			$direction = $directions[array_rand($directions)];
+
+			// Switch colors
+			if (mt_rand(0, 1) === 1)
+			{
+				$temp = $color1;
+				$color1 = $color2;
+				$color2 = $temp;
+			}
+		}
+
+		// Extract RGB values
+		$color1 = imagecolorsforindex($this->image, $color1);
+		$color2 = imagecolorsforindex($this->image, $color2);
+
+		// Preparations for the gradient loop
+		$steps = ($direction === 'horizontal') ? Captcha::$config['width'] : Captcha::$config['height'];
+
+		$r1 = ($color1['red'] - $color2['red']) / $steps;
+		$g1 = ($color1['green'] - $color2['green']) / $steps;
+		$b1 = ($color1['blue'] - $color2['blue']) / $steps;
+
+		if ($direction === 'horizontal')
+		{
+			$x1 =& $i;
+			$y1 = 0;
+			$x2 =& $i;
+			$y2 = Captcha::$config['height'];
+		}
+		else
+		{
+			$x1 = 0;
+			$y1 =& $i;
+			$x2 = Captcha::$config['width'];
+			$y2 =& $i;
+		}
+
+		// Execute the gradient loop
+		for ($i = 0; $i <= $steps; $i++)
+		{
+			$r2 = $color1['red'] - floor($i * $r1);
+			$g2 = $color1['green'] - floor($i * $g1);
+			$b2 = $color1['blue'] - floor($i * $b1);
+			$color = imagecolorallocate($this->image, $r2, $g2, $b2);
+
+			imageline($this->image, $x1, $y1, $x2, $y2, $color);
+		}
+	}
+
+	/**
+	 * Returns the img html element or outputs the image to the browser.
+	 *
+	 * @param   boolean  html output
+	 * @return  mixed    html string or void
+	 */
+	public function image_render($html)
+	{
+		// Output html element
+		if ($html)
+			return '<img alt="Captcha" src="'.url::site('captcha/'.Captcha::$config['group']).'" width="'.Captcha::$config['width'].'" height="'.Captcha::$config['height'].'" />';
+
+		// Send the correct HTTP header
+		header('Content-Type: image/'.$this->image_type);
+
+		// Pick the correct output function
+		$function = 'image'.$this->image_type;
+		$function($this->image);
+
+		// Free up resources
+		imagedestroy($this->image);
+	}
+
+} // End Captcha Driver
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