/system/plugins/captcha_pi.php

  1<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
  2/**
  3 * CodeIgniter
  4 *
  5 * An open source application development framework for PHP 4.3.2 or newer
  6 *
  7 * @package		CodeIgniter
  8 * @author		ExpressionEngine Dev Team
  9 * @copyright	Copyright (c) 2008 - 2010, EllisLab, Inc.
 10 * @license		http://codeigniter.com/user_guide/license.html
 11 * @link		http://codeigniter.com
 12 * @since		Version 1.0
 13 * @filesource
 14 */
 15
 16// ------------------------------------------------------------------------
 17
 18/*
 19Instructions:
 20
 21Load the plugin using:
 22
 23 	$this->load->plugin('captcha');
 24
 25Once loaded you can generate a captcha like this:
 26	
 27	$vals = array(
 28					'word'		 => 'Random word',
 29					'img_path'	 => './captcha/',
 30					'img_url'	 => 'http://example.com/captcha/',
 31					'font_path'	 => './system/fonts/texb.ttf',
 32					'img_width'	 => '150',
 33					'img_height' => 30,
 34					'expiration' => 7200
 35				);
 36	
 37	$cap = create_captcha($vals);
 38	echo $cap['image'];
 39	
 40
 41NOTES:
 42	
 43	The captcha function requires the GD image library.
 44	
 45	Only the img_path and img_url are required.
 46	
 47	If a "word" is not supplied, the function will generate a random
 48	ASCII string.  You might put together your own word library that
 49	you can draw randomly from.
 50	
 51	If you do not specify a path to a TRUE TYPE font, the native ugly GD
 52	font will be used.
 53	
 54	The "captcha" folder must be writable (666, or 777)
 55	
 56	The "expiration" (in seconds) signifies how long an image will
 57	remain in the captcha folder before it will be deleted.  The default
 58	is two hours.
 59
 60RETURNED DATA
 61
 62The create_captcha() function returns an associative array with this data:
 63
 64  [array]
 65  (
 66	'image' => IMAGE TAG
 67	'time'	=> TIMESTAMP (in microtime)
 68	'word'	=> CAPTCHA WORD
 69  )
 70
 71The "image" is the actual image tag:
 72<img src="http://example.com/captcha/12345.jpg" width="140" height="50" />
 73
 74The "time" is the micro timestamp used as the image name without the file
 75extension.  It will be a number like this:  1139612155.3422
 76
 77The "word" is the word that appears in the captcha image, which if not
 78supplied to the function, will be a random string.
 79
 80
 81ADDING A DATABASE
 82
 83In order for the captcha function to prevent someone from posting, you will need
 84to add the information returned from create_captcha() function to your database.
 85Then, when the data from the form is submitted by the user you will need to verify
 86that the data exists in the database and has not expired.
 87
 88Here is a table prototype:
 89
 90	CREATE TABLE captcha (
 91	 captcha_id bigint(13) unsigned NOT NULL auto_increment,
 92	 captcha_time int(10) unsigned NOT NULL,
 93	 ip_address varchar(16) default '0' NOT NULL,
 94	 word varchar(20) NOT NULL,
 95	 PRIMARY KEY `captcha_id` (`captcha_id`),
 96	 KEY `word` (`word`)
 97	)
 98
 99
100Here is an example of usage with a DB.
101
102On the page where the captcha will be shown you'll have something like this:
103
104	$this->load->plugin('captcha');
105	$vals = array(
106					'img_path'	 => './captcha/',
107					'img_url'	 => 'http://example.com/captcha/'
108				);
109	
110	$cap = create_captcha($vals);
111
112	$data = array(
113					'captcha_id'	=> '',
114					'captcha_time'	=> $cap['time'],
115					'ip_address'	=> $this->input->ip_address(),
116					'word'			=> $cap['word']
117				);
118
119	$query = $this->db->insert_string('captcha', $data);
120	$this->db->query($query);
121		
122	echo 'Submit the word you see below:';
123	echo $cap['image'];
124	echo '<input type="text" name="captcha" value="" />';
125
126
127Then, on the page that accepts the submission you'll have something like this:
128
129	// First, delete old captchas
130	$expiration = time()-7200; // Two hour limit
131	$DB->query("DELETE FROM captcha WHERE captcha_time < ".$expiration);		
132
133	// Then see if a captcha exists:
134	$sql = "SELECT COUNT(*) AS count FROM captcha WHERE word = ? AND ip_address = ? AND date > ?";
135	$binds = array($_POST['captcha'], $this->input->ip_address(), $expiration);
136	$query = $this->db->query($sql, $binds);
137	$row = $query->row();
138
139	if ($row->count == 0)
140	{
141		echo "You must submit the word that appears in the image";
142	}
143
144*/
145
146
147	
148/**
149|==========================================================
150| Create Captcha
151|==========================================================
152|
153*/
154function create_captcha($data = '', $img_path = '', $img_url = '', $font_path = '')
155{		
156	$defaults = array('word' => '', 'img_path' => '', 'img_url' => '', 'img_width' => '150', 'img_height' => '30', 'font_path' => '', 'expiration' => 7200);		
157	
158	foreach ($defaults as $key => $val)
159	{
160		if ( ! is_array($data))
161		{
162			if ( ! isset($$key) OR $$key == '')
163			{
164				$$key = $val;
165			}
166		}
167		else
168		{			
169			$$key = ( ! isset($data[$key])) ? $val : $data[$key];
170		}
171	}
172	
173	if ($img_path == '' OR $img_url == '')
174	{
175		return FALSE;
176	}
177
178	if ( ! @is_dir($img_path))
179	{
180		return FALSE;
181	}
182	
183	if ( ! is_really_writable($img_path))
184	{
185		return FALSE;
186	}
187			
188	if ( ! extension_loaded('gd'))
189	{
190		return FALSE;
191	}		
192	
193	// -----------------------------------
194	// Remove old images	
195	// -----------------------------------
196			
197	list($usec, $sec) = explode(" ", microtime());
198	$now = ((float)$usec + (float)$sec);
199			
200	$current_dir = @opendir($img_path);
201	
202	while($filename = @readdir($current_dir))
203	{
204		if ($filename != "." and $filename != ".." and $filename != "index.html")
205		{
206			$name = str_replace(".jpg", "", $filename);
207		
208			if (($name + $expiration) < $now)
209			{
210				@unlink($img_path.$filename);
211			}
212		}
213	}
214	
215	@closedir($current_dir);
216
217	// -----------------------------------
218	// Do we have a "word" yet?
219	// -----------------------------------
220	
221   if ($word == '')
222   {
223		$pool = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
224
225		$str = '';
226		for ($i = 0; $i < 8; $i++)
227		{
228			$str .= substr($pool, mt_rand(0, strlen($pool) -1), 1);
229		}
230		
231		$word = $str;
232   }
233	
234	// -----------------------------------
235	// Determine angle and position	
236	// -----------------------------------
237	
238	$length	= strlen($word);
239	$angle	= ($length >= 6) ? rand(-($length-6), ($length-6)) : 0;
240	$x_axis	= rand(6, (360/$length)-16);			
241	$y_axis = ($angle >= 0 ) ? rand($img_height, $img_width) : rand(6, $img_height);
242	
243	// -----------------------------------
244	// Create image
245	// -----------------------------------
246			
247	// PHP.net recommends imagecreatetruecolor(), but it isn't always available
248	if (function_exists('imagecreatetruecolor'))
249	{
250		$im = imagecreatetruecolor($img_width, $img_height);
251	}
252	else
253	{
254		$im = imagecreate($img_width, $img_height);
255	}
256			
257	// -----------------------------------
258	//  Assign colors
259	// -----------------------------------
260	
261	$bg_color		= imagecolorallocate ($im, 255, 255, 255);
262	$border_color	= imagecolorallocate ($im, 153, 102, 102);
263	$text_color		= imagecolorallocate ($im, 204, 153, 153);
264	$grid_color		= imagecolorallocate($im, 255, 182, 182);
265	$shadow_color	= imagecolorallocate($im, 255, 240, 240);
266
267	// -----------------------------------
268	//  Create the rectangle
269	// -----------------------------------
270	
271	ImageFilledRectangle($im, 0, 0, $img_width, $img_height, $bg_color);
272	
273	// -----------------------------------
274	//  Create the spiral pattern
275	// -----------------------------------
276	
277	$theta		= 1;
278	$thetac		= 7;
279	$radius		= 16;
280	$circles	= 20;
281	$points		= 32;
282
283	for ($i = 0; $i < ($circles * $points) - 1; $i++)
284	{
285		$theta = $theta + $thetac;
286		$rad = $radius * ($i / $points );
287		$x = ($rad * cos($theta)) + $x_axis;
288		$y = ($rad * sin($theta)) + $y_axis;
289		$theta = $theta + $thetac;
290		$rad1 = $radius * (($i + 1) / $points);
291		$x1 = ($rad1 * cos($theta)) + $x_axis;
292		$y1 = ($rad1 * sin($theta )) + $y_axis;
293		imageline($im, $x, $y, $x1, $y1, $grid_color);
294		$theta = $theta - $thetac;
295	}
296
297	// -----------------------------------
298	//  Write the text
299	// -----------------------------------
300	
301	$use_font = ($font_path != '' AND file_exists($font_path) AND function_exists('imagettftext')) ? TRUE : FALSE;
302		
303	if ($use_font == FALSE)
304	{
305		$font_size = 5;
306		$x = rand(0, $img_width/($length/3));
307		$y = 0;
308	}
309	else
310	{
311		$font_size	= 16;
312		$x = rand(0, $img_width/($length/1.5));
313		$y = $font_size+2;
314	}
315
316	for ($i = 0; $i < strlen($word); $i++)
317	{
318		if ($use_font == FALSE)
319		{
320			$y = rand(0 , $img_height/2);
321			imagestring($im, $font_size, $x, $y, substr($word, $i, 1), $text_color);
322			$x += ($font_size*2);
323		}
324		else
325		{		
326			$y = rand($img_height/2, $img_height-3);
327			imagettftext($im, $font_size, $angle, $x, $y, $text_color, $font_path, substr($word, $i, 1));
328			$x += $font_size;
329		}
330	}
331	
332
333	// -----------------------------------
334	//  Create the border
335	// -----------------------------------
336
337	imagerectangle($im, 0, 0, $img_width-1, $img_height-1, $border_color);		
338
339	// -----------------------------------
340	//  Generate the image
341	// -----------------------------------
342	
343	$img_name = $now.'.jpg';
344
345	ImageJPEG($im, $img_path.$img_name);
346	
347	$img = "<img src=\"$img_url$img_name\" width=\"$img_width\" height=\"$img_height\" style=\"border:0;\" alt=\" \" />";
348	
349	ImageDestroy($im);
350		
351	return array('word' => $word, 'time' => $now, 'image' => $img);
352}
353
354
355/* End of file captcha_pi.php */
356/* Location: ./system/plugins/captcha_pi.php */