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Diffstat (limited to 'system/plugins/captcha_pi.php')
| -rw-r--r-- | system/plugins/captcha_pi.php | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/system/plugins/captcha_pi.php b/system/plugins/captcha_pi.php new file mode 100644 index 000000000..36a74c42f --- /dev/null +++ b/system/plugins/captcha_pi.php @@ -0,0 +1,356 @@ +<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed'); +/** + * CodeIgniter + * + * An open source application development framework for PHP 4.3.2 or newer + * + * @package CodeIgniter + * @author ExpressionEngine Dev Team + * @copyright Copyright (c) 2008 - 2009, EllisLab, Inc. + * @license http://codeigniter.com/user_guide/license.html + * @link http://codeigniter.com + * @since Version 1.0 + * @filesource + */ + +// ------------------------------------------------------------------------ + +/* +Instructions: + +Load the plugin using: + + $this->load->plugin('captcha'); + +Once loaded you can generate a captcha like this: + + $vals = array( + 'word' => 'Random word', + 'img_path' => './captcha/', + 'img_url' => 'http://example.com/captcha/', + 'font_path' => './system/fonts/texb.ttf', + 'img_width' => '150', + 'img_height' => 30, + 'expiration' => 7200 + ); + + $cap = create_captcha($vals); + echo $cap['image']; + + +NOTES: + + The captcha function requires the GD image library. + + Only the img_path and img_url are required. + + If a "word" is not supplied, the function will generate a random + ASCII string. You might put together your own word library that + you can draw randomly from. + + If you do not specify a path to a TRUE TYPE font, the native ugly GD + font will be used. + + The "captcha" folder must be writable (666, or 777) + + The "expiration" (in seconds) signifies how long an image will + remain in the captcha folder before it will be deleted. The default + is two hours. + +RETURNED DATA + +The create_captcha() function returns an associative array with this data: + + [array] + ( + 'image' => IMAGE TAG + 'time' => TIMESTAMP (in microtime) + 'word' => CAPTCHA WORD + ) + +The "image" is the actual image tag: +<img src="http://example.com/captcha/12345.jpg" width="140" height="50" /> + +The "time" is the micro timestamp used as the image name without the file +extension. It will be a number like this: 1139612155.3422 + +The "word" is the word that appears in the captcha image, which if not +supplied to the function, will be a random string. + + +ADDING A DATABASE + +In order for the captcha function to prevent someone from posting, you will need +to add the information returned from create_captcha() function to your database. +Then, when the data from the form is submitted by the user you will need to verify +that the data exists in the database and has not expired. + +Here is a table prototype: + + CREATE TABLE captcha ( + captcha_id bigint(13) unsigned NOT NULL auto_increment, + captcha_time int(10) unsigned NOT NULL, + ip_address varchar(16) default '0' NOT NULL, + word varchar(20) NOT NULL, + PRIMARY KEY `captcha_id` (`captcha_id`), + KEY `word` (`word`) + ) + + +Here is an example of usage with a DB. + +On the page where the captcha will be shown you'll have something like this: + + $this->load->plugin('captcha'); + $vals = array( + 'img_path' => './captcha/', + 'img_url' => 'http://example.com/captcha/' + ); + + $cap = create_captcha($vals); + + $data = array( + 'captcha_id' => '', + 'captcha_time' => $cap['time'], + 'ip_address' => $this->input->ip_address(), + 'word' => $cap['word'] + ); + + $query = $this->db->insert_string('captcha', $data); + $this->db->query($query); + + echo 'Submit the word you see below:'; + echo $cap['image']; + echo '<input type="text" name="captcha" value="" />'; + + +Then, on the page that accepts the submission you'll have something like this: + + // First, delete old captchas + $expiration = time()-7200; // Two hour limit + $DB->query("DELETE FROM captcha WHERE captcha_time < ".$expiration); + + // Then see if a captcha exists: + $sql = "SELECT COUNT(*) AS count FROM captcha WHERE word = ? AND ip_address = ? AND date > ?"; + $binds = array($_POST['captcha'], $this->input->ip_address(), $expiration); + $query = $this->db->query($sql, $binds); + $row = $query->row(); + + if ($row->count == 0) + { + echo "You must submit the word that appears in the image"; + } + +*/ + + + +/** +|========================================================== +| Create Captcha +|========================================================== +| +*/ +function create_captcha($data = '', $img_path = '', $img_url = '', $font_path = '') +{ + $defaults = array('word' => '', 'img_path' => '', 'img_url' => '', 'img_width' => '150', 'img_height' => '30', 'font_path' => '', 'expiration' => 7200); + + foreach ($defaults as $key => $val) + { + if ( ! is_array($data)) + { + if ( ! isset($$key) OR $$key == '') + { + $$key = $val; + } + } + else + { + $$key = ( ! isset($data[$key])) ? $val : $data[$key]; + } + } + + if ($img_path == '' OR $img_url == '') + { + return FALSE; + } + + if ( ! @is_dir($img_path)) + { + return FALSE; + } + + if ( ! is_really_writable($img_path)) + { + return FALSE; + } + + if ( ! extension_loaded('gd')) + { + return FALSE; + } + + // ----------------------------------- + // Remove old images + // ----------------------------------- + + list($usec, $sec) = explode(" ", microtime()); + $now = ((float)$usec + (float)$sec); + + $current_dir = @opendir($img_path); + + while($filename = @readdir($current_dir)) + { + if ($filename != "." and $filename != ".." and $filename != "index.html") + { + $name = str_replace(".jpg", "", $filename); + + if (($name + $expiration) < $now) + { + @unlink($img_path.$filename); + } + } + } + + @closedir($current_dir); + + // ----------------------------------- + // Do we have a "word" yet? + // ----------------------------------- + + if ($word == '') + { + $pool = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'; + + $str = ''; + for ($i = 0; $i < 8; $i++) + { + $str .= substr($pool, mt_rand(0, strlen($pool) -1), 1); + } + + $word = $str; + } + + // ----------------------------------- + // Determine angle and position + // ----------------------------------- + + $length = strlen($word); + $angle = ($length >= 6) ? rand(-($length-6), ($length-6)) : 0; + $x_axis = rand(6, (360/$length)-16); + $y_axis = ($angle >= 0 ) ? rand($img_height, $img_width) : rand(6, $img_height); + + // ----------------------------------- + // Create image + // ----------------------------------- + + // PHP.net recommends imagecreatetruecolor(), but it isn't always available + if (function_exists('imagecreatetruecolor')) + { + $im = imagecreatetruecolor($img_width, $img_height); + } + else + { + $im = imagecreate($img_width, $img_height); + } + + // ----------------------------------- + // Assign colors + // ----------------------------------- + + $bg_color = imagecolorallocate ($im, 255, 255, 255); + $border_color = imagecolorallocate ($im, 153, 102, 102); + $text_color = imagecolorallocate ($im, 204, 153, 153); + $grid_color = imagecolorallocate($im, 255, 182, 182); + $shadow_color = imagecolorallocate($im, 255, 240, 240); + + // ----------------------------------- + // Create the rectangle + // ----------------------------------- + + ImageFilledRectangle($im, 0, 0, $img_width, $img_height, $bg_color); + + // ----------------------------------- + // Create the spiral pattern + // ----------------------------------- + + $theta = 1; + $thetac = 7; + $radius = 16; + $circles = 20; + $points = 32; + + for ($i = 0; $i < ($circles * $points) - 1; $i++) + { + $theta = $theta + $thetac; + $rad = $radius * ($i / $points ); + $x = ($rad * cos($theta)) + $x_axis; + $y = ($rad * sin($theta)) + $y_axis; + $theta = $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, $grid_color); + $theta = $theta - $thetac; + } + + // ----------------------------------- + // Write the text + // ----------------------------------- + + $use_font = ($font_path != '' AND file_exists($font_path) AND function_exists('imagettftext')) ? TRUE : FALSE; + + if ($use_font == FALSE) + { + $font_size = 5; + $x = rand(0, $img_width/($length/3)); + $y = 0; + } + else + { + $font_size = 16; + $x = rand(0, $img_width/($length/1.5)); + $y = $font_size+2; + } + + for ($i = 0; $i < strlen($word); $i++) + { + if ($use_font == FALSE) + { + $y = rand(0 , $img_height/2); + imagestring($im, $font_size, $x, $y, substr($word, $i, 1), $text_color); + $x += ($font_size*2); + } + else + { + $y = rand($img_height/2, $img_height-3); + imagettftext($im, $font_size, $angle, $x, $y, $text_color, $font_path, substr($word, $i, 1)); + $x += $font_size; + } + } + + + // ----------------------------------- + // Create the border + // ----------------------------------- + + imagerectangle($im, 0, 0, $img_width-1, $img_height-1, $border_color); + + // ----------------------------------- + // Generate the image + // ----------------------------------- + + $img_name = $now.'.jpg'; + + ImageJPEG($im, $img_path.$img_name); + + $img = "<img src=\"$img_url$img_name\" width=\"$img_width\" height=\"$img_height\" style=\"border:0;\" alt=\" \" />"; + + ImageDestroy($im); + + return array('word' => $word, 'time' => $now, 'image' => $img); +} + + +/* End of file captcha_pi.php */ +/* Location: ./system/plugins/captcha_pi.php */
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