ci-bonfire / Sprint

system/helpers/captcha_helper.php

<?php

For compatibility and reusability of your code, PSR1 recommends that a file should introduce either new symbols (like classes, functions, etc.) or have side-effects (like outputting something, or including other files), but not both at the same time. The first symbol is defined on line 63 and the first side effect is on line 38.

/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2015, 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. (http://ellislab.com/)
 * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
 * @license	http://opensource.org/licenses/MIT	MIT License
 * @link	http://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		http://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 (substr($filename, -4) === '.jpg' && (str_replace('.jpg', '', $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)
				{
					list(, $rand_index) = unpack('C', $bytes[$byte_index++]);
					if ($rand_index > $rand_max)
					{
						// Was this the last byte we have?
						// If so, try to fetch more.
						if ($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;
							}
						}

						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);
	}
}