81 lines
2.7 KiB
PHP
81 lines
2.7 KiB
PHP
<?php defined('SYSPATH') OR die('No direct access allowed.');
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/**
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* Captcha driver for "basic" style.
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*
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* $Id: Basic.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_Basic_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, Captcha::$config['complexity']));
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}
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/**
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* Outputs the Captcha image.
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*
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* @param boolean html output
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* @return mixed
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*/
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public function render($html)
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{
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// Creates $this->image
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$this->image_create(Captcha::$config['background']);
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// Add a random gradient
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if (empty(Captcha::$config['background']))
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{
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$color1 = imagecolorallocate($this->image, mt_rand(200, 255), mt_rand(200, 255), mt_rand(150, 255));
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$color2 = imagecolorallocate($this->image, mt_rand(200, 255), mt_rand(200, 255), mt_rand(150, 255));
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$this->image_gradient($color1, $color2);
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}
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// Add a few random lines
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for ($i = 0, $count = mt_rand(5, Captcha::$config['complexity'] * 4); $i < $count; $i++)
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{
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$color = imagecolorallocatealpha($this->image, mt_rand(0, 255), mt_rand(0, 255), mt_rand(100, 255), mt_rand(50, 120));
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imageline($this->image, mt_rand(0, Captcha::$config['width']), 0, mt_rand(0, Captcha::$config['width']), Captcha::$config['height'], $color);
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}
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// Calculate character font-size and spacing
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$default_size = min(Captcha::$config['width'], Captcha::$config['height'] * 2) / (strlen($this->response) + 1);
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$spacing = (int) (Captcha::$config['width'] * 0.9 / strlen($this->response));
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// Draw each Captcha character with varying attributes
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for ($i = 0, $strlen = strlen($this->response); $i < $strlen; $i++)
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{
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// Use different fonts if available
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$font = Captcha::$config['fontpath'].Captcha::$config['fonts'][array_rand(Captcha::$config['fonts'])];
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// Allocate random color, size and rotation attributes to text
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$color = imagecolorallocate($this->image, mt_rand(0, 150), mt_rand(0, 150), mt_rand(0, 150));
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$angle = mt_rand(-40, 20);
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// Scale the character size on image height
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$size = $default_size / 10 * mt_rand(8, 12);
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$box = imageftbbox($size, $angle, $font, $this->response[$i]);
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// Calculate character starting coordinates
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$x = $spacing / 4 + $i * $spacing;
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$y = Captcha::$config['height'] / 2 + ($box[2] - $box[5]) / 4;
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// Write text character to image
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imagefttext($this->image, $size, $angle, $x, $y, $color, $font, $this->response[$i]);
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}
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// Output
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return $this->image_render($html);
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}
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} // End Captcha Basic Driver Class
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