72 lines
3.2 KiB
PHP
72 lines
3.2 KiB
PHP
<?php defined('SYSPATH') OR die('No direct access allowed.');
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/**
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* Captcha driver for "black" style.
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*
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* $Id: Black.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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class Captcha_Black_Driver extends Captcha_Driver {
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/**
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* Generates 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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public function generate_challenge()
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{
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// Complexity setting is used as character count
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return text::random('distinct', max(1, ceil(Captcha::$config['complexity'] / 1.5)));
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}
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/**
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* Outputs the Captcha image.
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*
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* @param boolean html output
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* @return mixed
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*/
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public function render($html)
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{
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// Creates a black image to start from
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$this->image_create(Captcha::$config['background']);
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// Add random white/gray arcs, amount depends on complexity setting
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$count = (Captcha::$config['width'] + Captcha::$config['height']) / 2;
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$count = $count / 5 * min(10, Captcha::$config['complexity']);
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for ($i = 0; $i < $count; $i++)
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{
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imagesetthickness($this->image, mt_rand(1, 2));
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$color = imagecolorallocatealpha($this->image, 255, 255, 255, mt_rand(0, 120));
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imagearc($this->image, mt_rand(-Captcha::$config['width'], Captcha::$config['width']), mt_rand(-Captcha::$config['height'], Captcha::$config['height']), mt_rand(-Captcha::$config['width'], Captcha::$config['width']), mt_rand(-Captcha::$config['height'], Captcha::$config['height']), mt_rand(0, 360), mt_rand(0, 360), $color);
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}
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// Use different fonts if available
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$font = Captcha::$config['fontpath'].Captcha::$config['fonts'][array_rand(Captcha::$config['fonts'])];
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// Draw the character's white shadows
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$size = (int) min(Captcha::$config['height'] / 2, Captcha::$config['width'] * 0.8 / strlen($this->response));
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$angle = mt_rand(-15 + strlen($this->response), 15 - strlen($this->response));
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$x = mt_rand(1, Captcha::$config['width'] * 0.9 - $size * strlen($this->response));
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$y = ((Captcha::$config['height'] - $size) / 2) + $size;
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$color = imagecolorallocate($this->image, 255, 255, 255);
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imagefttext($this->image, $size, $angle, $x + 1, $y + 1, $color, $font, $this->response);
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// Add more shadows for lower complexities
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(Captcha::$config['complexity'] < 10) and imagefttext($this->image, $size, $angle, $x - 1, $y - 1, $color, $font , $this->response);
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(Captcha::$config['complexity'] < 8) and imagefttext($this->image, $size, $angle, $x - 2, $y + 2, $color, $font , $this->response);
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(Captcha::$config['complexity'] < 6) and imagefttext($this->image, $size, $angle, $x + 2, $y - 2, $color, $font , $this->response);
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(Captcha::$config['complexity'] < 4) and imagefttext($this->image, $size, $angle, $x + 3, $y + 3, $color, $font , $this->response);
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(Captcha::$config['complexity'] < 2) and imagefttext($this->image, $size, $angle, $x - 3, $y - 3, $color, $font , $this->response);
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// Finally draw the foreground characters
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$color = imagecolorallocate($this->image, 0, 0, 0);
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imagefttext($this->image, $size, $angle, $x, $y, $color, $font, $this->response);
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// Output
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return $this->image_render($html);
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}
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} // End Captcha Black Driver Class
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