<?php 
/** 
 * CodeIgniter 
 * 
 * An open source application development framework for PHP 
 * 
 * This content is released under the MIT License (MIT) 
 * 
 * Copyright (c) 2019 - 2022, CodeIgniter Foundation 
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy 
 * of this software and associated documentation files (the "Software"), to deal 
 * in the Software without restriction, including without limitation the rights 
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
 * copies of the Software, and to permit persons to whom the Software is 
 * furnished to do so, subject to the following conditions: 
 * 
 * The above copyright notice and this permission notice shall be included in 
 * all copies or substantial portions of the Software. 
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
 * THE SOFTWARE. 
 * 
 * @package    CodeIgniter 
 * @author    EllisLab Dev Team 
 * @copyright    Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/) 
 * @copyright    Copyright (c) 2014 - 2019, British Columbia Institute of Technology (https://bcit.ca/) 
 * @copyright    Copyright (c) 2019 - 2022, CodeIgniter Foundation (https://codeigniter.com/) 
 * @license    https://opensource.org/licenses/MIT    MIT License 
 * @link    https://codeigniter.com 
 * @since    Version 1.0.0 
 * @filesource 
 */ 
defined('BASEPATH') OR exit('No direct script access allowed'); 
 
/** 
 * CodeIgniter CAPTCHA Helper 
 * 
 * @package        CodeIgniter 
 * @subpackage    Helpers 
 * @category    Helpers 
 * @author        EllisLab Dev Team 
 * @link        https://codeigniter.com/userguide3/helpers/captcha_helper.html 
 */ 
 
// ------------------------------------------------------------------------ 
 
if ( ! function_exists('create_captcha')) 
{ 
    /** 
     * Create CAPTCHA 
     * 
     * @param    array    $data        Data for the CAPTCHA 
     * @param    string    $img_path    Path to create the image in (deprecated) 
     * @param    string    $img_url    URL to the CAPTCHA image folder (deprecated) 
     * @param    string    $font_path    Server path to font (deprecated) 
     * @return    string 
     */ 
    function create_captcha($data = '', $img_path = '', $img_url = '', $font_path = '') 
    { 
        $defaults = array( 
            'word'        => '', 
            'img_path'    => '', 
            'img_url'    => '', 
            'img_width'    => '150', 
            'img_height'    => '30', 
            'font_path'    => '', 
            'expiration'    => 7200, 
            'word_length'    => 8, 
            'font_size'    => 16, 
            'img_id'    => '', 
            'pool'        => '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ', 
            'colors'    => array( 
                'background'    => array(255,255,255), 
                'border'    => array(153,102,102), 
                'text'        => array(204,153,153), 
                'grid'        => array(255,182,182) 
            ) 
        ); 
 
        foreach ($defaults as $key => $val) 
        { 
            if ( ! is_array($data) && empty($$key)) 
            { 
                $$key = $val; 
            } 
            else 
            { 
                $$key = isset($data[$key]) ? $data[$key] : $val; 
            } 
        } 
 
        if ( ! extension_loaded('gd')) 
        { 
            log_message('error', 'create_captcha(): GD extension is not loaded.'); 
            return FALSE; 
        } 
 
        if ($img_path === '' OR $img_url === '') 
        { 
            log_message('error', 'create_captcha(): $img_path and $img_url are required.'); 
            return FALSE; 
        } 
 
        if ( ! is_dir($img_path) OR ! is_really_writable($img_path)) 
        { 
            log_message('error', "create_captcha(): '{$img_path}' is not a dir, nor is it writable."); 
            return FALSE; 
        } 
 
        // ----------------------------------- 
        // Remove old images 
        // ----------------------------------- 
 
        $now = microtime(TRUE); 
 
        $current_dir = @opendir($img_path); 
        while ($filename = @readdir($current_dir)) 
        { 
            if (in_array(substr($filename, -4), array('.jpg', '.png')) 
                && (str_replace(array('.jpg', '.png'), '', $filename) + $expiration) < $now) 
            { 
                @unlink($img_path.$filename); 
            } 
        } 
 
        @closedir($current_dir); 
 
        // ----------------------------------- 
        // Do we have a "word" yet? 
        // ----------------------------------- 
 
        if (empty($word)) 
        { 
            $word = ''; 
            $pool_length = strlen($pool); 
            $rand_max = $pool_length - 1; 
 
            // PHP7 or a suitable polyfill 
            if (function_exists('random_int')) 
            { 
                try 
                { 
                    for ($i = 0; $i < $word_length; $i++) 
                    { 
                        $word .= $pool[random_int(0, $rand_max)]; 
                    } 
                } 
                catch (Exception $e) 
                { 
                    // This means fallback to the next possible 
                    // alternative to random_int() 
                    $word = ''; 
                } 
            } 
        } 
 
        if (empty($word)) 
        { 
            // Nobody will have a larger character pool than 
            // 256 characters, but let's handle it just in case ... 
            // 
            // No, I do not care that the fallback to mt_rand() can 
            // handle it; if you trigger this, you're very obviously 
            // trying to break it. -- Narf 
            if ($pool_length > 256) 
            { 
                return FALSE; 
            } 
 
            // We'll try using the operating system's PRNG first, 
            // which we can access through CI_Security::get_random_bytes() 
            $security = get_instance()->security; 
 
            // To avoid numerous get_random_bytes() calls, we'll 
            // just try fetching as much bytes as we need at once. 
            if (($bytes = $security->get_random_bytes($pool_length)) !== FALSE) 
            { 
                $byte_index = $word_index = 0; 
                while ($word_index < $word_length) 
                { 
                    // Do we have more random data to use? 
                    // It could be exhausted by previous iterations 
                    // ignoring bytes higher than $rand_max. 
                    if ($byte_index === $pool_length) 
                    { 
                        // No failures should be possible if the 
                        // first get_random_bytes() call didn't 
                        // return FALSE, but still ... 
                        for ($i = 0; $i < 5; $i++) 
                        { 
                            if (($bytes = $security->get_random_bytes($pool_length)) === FALSE) 
                            { 
                                continue; 
                            } 
 
                            $byte_index = 0; 
                            break; 
                        } 
 
                        if ($bytes === FALSE) 
                        { 
                            // Sadly, this means fallback to mt_rand() 
                            $word = ''; 
                            break; 
                        } 
                    } 
 
                    list(, $rand_index) = unpack('C', $bytes[$byte_index++]); 
                    if ($rand_index > $rand_max) 
                    { 
                        continue; 
                    } 
 
                    $word .= $pool[$rand_index]; 
                    $word_index++; 
                } 
            } 
        } 
 
        if (empty($word)) 
        { 
            for ($i = 0; $i < $word_length; $i++) 
            { 
                $word .= $pool[mt_rand(0, $rand_max)]; 
            } 
        } 
        elseif ( ! is_string($word)) 
        { 
            $word = (string) $word; 
        } 
 
        // ----------------------------------- 
        // Determine angle and position 
        // ----------------------------------- 
        $length    = strlen($word); 
        $angle    = ($length >= 6) ? mt_rand(-($length-6), ($length-6)) : 0; 
        $x_axis    = mt_rand(6, (360/$length)-16); 
        $y_axis = ($angle >= 0) ? mt_rand($img_height, $img_width) : mt_rand(6, $img_height); 
 
        // Create image 
        // PHP.net recommends imagecreatetruecolor(), but it isn't always available 
        $im = function_exists('imagecreatetruecolor') 
            ? imagecreatetruecolor($img_width, $img_height) 
            : imagecreate($img_width, $img_height); 
 
        // ----------------------------------- 
        //  Assign colors 
        // ---------------------------------- 
 
        is_array($colors) OR $colors = $defaults['colors']; 
 
        foreach (array_keys($defaults['colors']) as $key) 
        { 
            // Check for a possible missing value 
            is_array($colors[$key]) OR $colors[$key] = $defaults['colors'][$key]; 
            $colors[$key] = imagecolorallocate($im, $colors[$key][0], $colors[$key][1], $colors[$key][2]); 
        } 
 
        // Create the rectangle 
        ImageFilledRectangle($im, 0, 0, $img_width, $img_height, $colors['background']); 
 
        // ----------------------------------- 
        //  Create the spiral pattern 
        // ----------------------------------- 
        $theta        = 1; 
        $thetac        = 7; 
        $radius        = 16; 
        $circles    = 20; 
        $points        = 32; 
 
        for ($i = 0, $cp = ($circles * $points) - 1; $i < $cp; $i++) 
        { 
            $theta += $thetac; 
            $rad = $radius * ($i / $points); 
            $x = ($rad * cos($theta)) + $x_axis; 
            $y = ($rad * sin($theta)) + $y_axis; 
            $theta += $thetac; 
            $rad1 = $radius * (($i + 1) / $points); 
            $x1 = ($rad1 * cos($theta)) + $x_axis; 
            $y1 = ($rad1 * sin($theta)) + $y_axis; 
            imageline($im, $x, $y, $x1, $y1, $colors['grid']); 
            $theta -= $thetac; 
        } 
 
        // ----------------------------------- 
        //  Write the text 
        // ----------------------------------- 
 
        $use_font = ($font_path !== '' && file_exists($font_path) && function_exists('imagettftext')); 
        if ($use_font === FALSE) 
        { 
            ($font_size > 5) && $font_size = 5; 
            $x = mt_rand(0, $img_width / ($length / 3)); 
            $y = 0; 
        } 
        else 
        { 
            ($font_size > 30) && $font_size = 30; 
            $x = mt_rand(0, $img_width / ($length / 1.5)); 
            $y = $font_size + 2; 
        } 
 
        for ($i = 0; $i < $length; $i++) 
        { 
            if ($use_font === FALSE) 
            { 
                $y = mt_rand(0 , $img_height / 2); 
                imagestring($im, $font_size, $x, $y, $word[$i], $colors['text']); 
                $x += ($font_size * 2); 
            } 
            else 
            { 
                $y = mt_rand($img_height / 2, $img_height - 3); 
                imagettftext($im, $font_size, $angle, $x, $y, $colors['text'], $font_path, $word[$i]); 
                $x += $font_size; 
            } 
        } 
 
        // Create the border 
        imagerectangle($im, 0, 0, $img_width - 1, $img_height - 1, $colors['border']); 
 
        // ----------------------------------- 
        //  Generate the image 
        // ----------------------------------- 
        $img_url = rtrim($img_url, '/').'/'; 
 
        if (function_exists('imagejpeg')) 
        { 
            $img_filename = $now.'.jpg'; 
            imagejpeg($im, $img_path.$img_filename); 
        } 
        elseif (function_exists('imagepng')) 
        { 
            $img_filename = $now.'.png'; 
            imagepng($im, $img_path.$img_filename); 
        } 
        else 
        { 
            return FALSE; 
        } 
 
        $img = '<img '.($img_id === '' ? '' : 'id="'.$img_id.'"').' src="'.$img_url.$img_filename.'" style="width: '.$img_width.'px; height: '.$img_height .'px; border: 0;" alt=" " />'; 
        ImageDestroy($im); 
 
        return array('word' => $word, 'time' => $now, 'image' => $img, 'filename' => $img_filename); 
    } 
} 
 
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