<?php
/**
* CodeIgniter
*
* An open source application development framework for PHP
*
* This content is released under the MIT License (MIT)
*
* Copyright (c) 2014 - 2018, 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 - 2018, 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 (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] : $val;
}
}
if ($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);
}
}
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