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File: system/helpers/captcha_helper.php

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File: system/helpers/captcha_helper.php
Role: Example script
Content type: text/plain
Description: Example script
Class: PHP User Feedback System
Application to record feedback from customers
Author: By
Last change:
Date: 4 years ago
Size: 9,546 bytes
 

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<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
 *
 * 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 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
 * @license http://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/user_guide/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
     * @param string $img_url URL to the CAPTCHA image folder
     * @param string $font_path server path to font
     * @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 (
$img_path === '' OR $img_url === ''
           
OR ! is_dir($img_path) OR ! is_really_writable($img_path)
            OR !
extension_loaded('gd'))
        {
            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.'; height: '.$img_height .'; border: 0;" alt=" " />';
       
ImageDestroy($im);

        return array(
'word' => $word, 'time' => $now, 'image' => $img, 'filename' => $img_filename);
    }
}