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