source: trunk/www.guidonia.net/wp/wp-content/plugins/really-simple-captcha/really-simple-captcha.php@ 44

Last change on this file since 44 was 44, checked in by luciano, 15 years ago
File size: 4.9 KB
RevLine 
[44]1<?php
2/*
3Plugin Name: Really Simple CAPTCHA
4Plugin URI: http://ideasilo.wordpress.com/2009/03/14/really-simple-captcha/
5Description: Really Simple CAPTCHA is a CAPTCHA module intended to be called from other plugins. It is originally created for my Contact Form 7 plugin.
6Author: Takayuki Miyoshi
7Version: 1.0
8Author URI: http://ideasilo.wordpress.com/
9*/
10
11/* Copyright 2007-2009 Takayuki Miyoshi (email: takayukister at gmail.com)
12
13 This program is free software; you can redistribute it and/or modify
14 it under the terms of the GNU General Public License as published by
15 the Free Software Foundation; either version 2 of the License, or
16 (at your option) any later version.
17
18 This program is distributed in the hope that it will be useful,
19 but WITHOUT ANY WARRANTY; without even the implied warranty of
20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 GNU General Public License for more details.
22
23 You should have received a copy of the GNU General Public License
24 along with this program; if not, write to the Free Software
25 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
26*/
27
28class ReallySimpleCaptcha {
29
30 function ReallySimpleCaptcha() {
31
32 /* Characters you can use in an image */
33 $this->chars = 'ABCDEFGHJKLMNPQRSTUVWXYZ23456789';
34
35 /* Length of a word in an image */
36 $this->char_length = 4;
37
38 /* Array of fonts. Randomly picked up per character */
39 $this->fonts = array(
40 dirname(__FILE__) . '/gentium/GenAI102.TTF',
41 dirname(__FILE__) . '/gentium/GenAR102.TTF',
42 dirname(__FILE__) . '/gentium/GenI102.TTF',
43 dirname(__FILE__) . '/gentium/GenR102.TTF');
44
45 /* Directory CAPTCHA image and corresponding code kept temporary */
46 $this->tmp_dir = dirname(__FILE__) . '/tmp/';
47
48 /* Array of CAPTCHA image size. Width and height */
49 $this->img_size = array(72, 24);
50
51 /* Background color of CAPTCHA image. RGB color 0-255 */
52 $this->bg = array(255, 255, 255);
53
54 /* Foreground (character) color of CAPTCHA image. RGB color 0-255 */
55 $this->fg = array(0, 0, 0);
56
57 /* Coordinates for a text in an image. I don't know the meaning. Just adjust. */
58 $this->base = array(6, 18);
59
60 /* Font size */
61 $this->font_size = 14;
62
63 /* Width of a character */
64 $this->font_char_width = 15;
65
66 /* Image type. 'png', 'gif' or 'jpeg' */
67 $this->img_type = 'png';
68
69 /* Mode of temporary files */
70 $this->file_mode = 0755;
71 }
72
73 /* Generate and return random word with $chars characters x $char_length length */
74 function generate_random_word() {
75 $word = '';
76 for ($i = 0; $i < $this->char_length; $i++) {
77 $pos = mt_rand(0, strlen($this->chars) - 1);
78 $char = $this->chars[$pos];
79 $word .= $char;
80 }
81 return $word;
82 }
83
84 /* Generate CAPTCHA code and corresponding code and save them into $tmp_dir directory.
85 $prefix is file prefix for both files. $captcha is a random word usually generated by generate_random_word()
86 This function returns the filename of the CAPTCHA image temporary file */
87 function generate_image($prefix, $word) {
88 $filename = null;
89 if ($im = imagecreatetruecolor($this->img_size[0], $this->img_size[1])) {
90 $bg = imagecolorallocate($im, $this->bg[0], $this->bg[1], $this->bg[2]);
91 $fg = imagecolorallocate($im, $this->fg[0], $this->fg[1], $this->fg[2]);
92 imagefill($im, 0, 0, $bg);
93 $x = $this->base[0] + mt_rand(-2, 2);
94 for ($i = 0; $i < strlen($word); $i++) {
95 $font = $this->fonts[array_rand($this->fonts)];
96 imagettftext($im, $this->font_size, mt_rand(-2, 2), $x, $this->base[1] + mt_rand(-2, 2), $fg, $font, $word[$i]);
97 $x += $this->font_char_width;
98 }
99 switch ($this->img_type) {
100 case 'jpeg':
101 $filename = $prefix . '.jpeg';
102 imagejpeg($im, $this->tmp_dir . $filename);
103 break;
104 case 'gif':
105 $filename = $prefix . '.gif';
106 imagegif($im, $this->tmp_dir . $filename);
107 break;
108 case 'png':
109 default:
110 $filename = $prefix . '.png';
111 imagepng($im, $this->tmp_dir . $filename);
112 }
113 imagedestroy($im);
114 @chmod($this->tmp_dir . $filename, $this->file_mode);
115 }
116 if ($fh = fopen($this->tmp_dir . $prefix . '.php', 'w')) {
117 @chmod($this->tmp_dir . $prefix . '.php', $this->file_mode);
118 fwrite($fh, '<?php $captcha = "' . $word . '"; ?>');
119 fclose($fh);
120 }
121 return $filename;
122 }
123
124 /* Check a $response against the code kept in the temporary file with $prefix
125 Return true if the two match, otherwise return false. */
126 function check($prefix, $response) {
127 if (is_readable($this->tmp_dir . $prefix . '.php')) {
128 include($this->tmp_dir . $prefix . '.php');
129 if (0 == strcasecmp($response, $captcha))
130 return true;
131 }
132 return false;
133 }
134
135 /* Remove temporary files with $prefix */
136 function remove($prefix) {
137 $suffixes = array('.jpeg', '.gif', '.png', '.php');
138 foreach ($suffixes as $suffix) {
139 $file = $this->tmp_dir . $prefix . $suffix;
140 if (is_file($file))
141 unlink($file);
142 }
143 }
144}
145
146?>
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