summaryrefslogtreecommitdiffstats
path: root/system/helpers/captcha_helper.php
blob: 03c1dd8525c5a937b2a4bcb481abf944a1c6d389 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
<?php
/**
 * 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);
	}
}