File Source for securimage.php

<?php
/**
* Project: Securimage: A PHP class for creating and managing form CAPTCHA images
* File: securimage.php
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Any modifications to the library should be indicated clearly in the source code
* to inform users that the changes are not a part of the original software.
*
* If you found this script useful, please take a quick moment to rate it.
* http://www.hotscripts.com/rate/49400.html Thanks.
*
* @link http://www.phpcaptcha.org Securimage PHP CAPTCHA
* @link http://www.phpcaptcha.org/latest.zip Download Latest Version
* @link http://www.phpcaptcha.org/Securimage_Docs/ Online Documentation
* @copyright 2007 Drew Phillips
* @author drew010 <drew@drew-phillips.com>
* @version 1.0.2 (January 6, 2008)
* @package Securimage
*
*/
/**
ChangeLog
1.0.1
- Audible CAPTCHA Code wav files
- Create codes from a word list instead of random strings
1.0
- Added the ability to use a selected character set, rather than a-z0-9 only.
- Added the multi-color text option to use different colors for each letter.
- Switched to automatic session handling instead of using files for code storage
- Added GD Font support if ttf support is not available. Can use internal GD fonts or load new ones.
- Added the ability to set line thickness
- Added option for drawing arced lines over letters
- Added ability to choose image type for output
*/
/**
* Output images in JPEG format
*/
define('SI_IMAGE_JPEG', 1);
/**
* Output images in PNG format
*/
define('SI_IMAGE_PNG', 2);
/**
* Output images in GIF format
* Must have GD >= 2.0.28!
*/
define('SI_IMAGE_GIF', 3);
/**
* Securimage CAPTCHA Class.
*
* @package Securimage
* @subpackage classes
*
*/
class Securimage {
/**
* The desired width of the CAPTCHA image.
*
* @var int
*/
var $image_width = 175;
/**
* The desired width of the CAPTCHA image.
*
* @var int
*/
var $image_height = 45;
/**
* The image format for output.
* Valid options: SI_IMAGE_PNG, SI_IMAGE_JPG, SI_IMAGE_GIF
*
* @var int
*/
var $image_type = SI_IMAGE_PNG;
/**
* The length of the code to generate.
*
* @var int
*/
var $code_length = 4;
/**
* The character set for individual characters in the image.
* Letters are converted to uppercase.
* The font must support the letters or there may be problematic substitutions.
*
* @var string
*/
var $charset = 'ABCDEFGHKLMNPRSTUVWYZ23456789';
//var $charset = '0123456789';
/**
* Create codes using this word list
*
* @var string The path to the word list to use for creating CAPTCHA codes
*/
var $wordlist_file = 'words/words.txt';
/**
* True to use a word list file instead of a random code
*
* @var bool
*/
var $use_wordlist = true;
/**
* Whether to use a GD font instead of a TTF font.
* TTF offers more support and options, but use this if your PHP doesn't support TTF.
*
* @var boolean
*/
var $use_gd_font = false;
/**
* The GD font to use.
* Internal gd fonts can be loaded by their number.
* Alternatively, a file path can be given and the font will be loaded from file.
*
* @var mixed
*/
var $gd_font_file = 'gdfonts/bubblebath.gdf';
/**
* The approximate size of the font in pixels.
* This does not control the size of the font because that is determined by the GD font itself.
* This is used to aid the calculations of positioning used by this class.
*
* @var int
*/
var $gd_font_size = 20;
// Note: These font options below do not apply if you set $use_gd_font to true with the exception of $text_color
/**
* The path to the TTF font file to load.
*
* @var string
*/
var $ttf_file = "./elephant.ttf";
/**
* The font size.
* Depending on your version of GD, this should be specified as the pixel size (GD1) or point size (GD2)
*
* @var int
*/
var $font_size = 24;
/**
* The minimum angle in degrees, with 0 degrees being left-to-right reading text.
* Higher values represent a counter-clockwise rotation.
* For example, a value of 90 would result in bottom-to-top reading text.
*
* @var int
*/
var $text_angle_minimum = -20;
/**
* The minimum angle in degrees, with 0 degrees being left-to-right reading text.
* Higher values represent a counter-clockwise rotation.
* For example, a value of 90 would result in bottom-to-top reading text.
*
* @var int
*/
var $text_angle_maximum = 20;
/**
* The X-Position on the image where letter drawing will begin.
* This value is in pixels from the left side of the image.
*
* @var int
*/
var $text_x_start = 8;
/**
* Letters can be spaced apart at random distances.
* This is the minimum distance between two letters.
* This should be at least as wide as a font character.
* Small values can cause letters to be drawn over eachother.
*
* @var int
*/
var $text_minimum_distance = 30;
/**
* Letters can be spaced apart at random distances.
* This is the maximum distance between two letters.
* This should be at least as wide as a font character.
* Small values can cause letters to be drawn over eachother.
*
* @var int
*/
var $text_maximum_distance = 33;
/**
* The background color for the image.
* This should be specified in HTML hex format.
* Make sure to include the preceding # sign!
*
* @var string
*/
var $image_bg_color = "#e3daed";
/**
* The text color to use for drawing characters.
* This value is ignored if $use_multi_text is set to true.
* Make sure this contrasts well with the background color.
* Specify the color in HTML hex format with preceding # sign
*
* @see Securimage::$use_multi_text
* @var string
*/
var $text_color = "#ff0000";
/**
* Set to true to use multiple colors for each character.
*
* @see Securimage::$multi_text_color
* @var boolean
*/
var $use_multi_text = true;
/**
* String of HTML hex colors to use.
* Separate each possible color with commas.
* Be sure to precede each value with the # sign.
*
* @var string
*/
var $multi_text_color = "#0a68dd,#f65c47,#8d32fd";
/**
* Set to true to make the characters appear transparent.
*
* @see Securimage::$text_transparency_percentage
* @var boolean
*/
var $use_transparent_text = true;
/**
* The percentage of transparency, 0 to 100.
* A value of 0 is completely opaque, 100 is completely transparent (invisble)
*
* @see Securimage::$use_transparent_text
* @var int
*/
var $text_transparency_percentage = 15;
// Line options
/**
* Draw vertical and horizontal lines on the image.
*
* @see Securimage::$line_color
* @see Securimage::$line_distance
* @see Securimage::$line_thickness
* @see Securimage::$draw_lines_over_text
* @var boolean
*/
var $draw_lines = true;
/**
* The color of the lines drawn on the image.
* Use HTML hex format with preceding # sign.
*
* @see Securimage::$draw_lines
* @var string
*/
var $line_color = "#80BFFF";
/**
* How far apart to space the lines from eachother in pixels.
*
* @see Securimage::$draw_lines
* @var int
*/
var $line_distance = 5;
/**
* How thick to draw the lines in pixels.
* 1-3 is ideal depending on distance
*
* @see Securimage::$draw_lines
* @see Securimage::$line_distance
* @var int
*/
var $line_thickness = 1;
/**
* Set to true to draw angled lines on the image in addition to the horizontal and vertical lines.
*
* @see Securimage::$draw_lines
* @var boolean
*/
var $draw_angled_lines = false;
/**
* Draw the lines over the text.
* If fales lines will be drawn before putting the text on the image.
* This can make the image hard for humans to read depending on the line thickness and distance.
*
* @var boolean
*/
var $draw_lines_over_text = false;
/**
* For added security, it is a good idea to draw arced lines over the letters to make it harder for bots to segment the letters.
* Two arced lines will be drawn over the text on each side of the image.
* This is currently expirimental and may be off in certain configurations.
*
* @var boolean
*/
var $arc_linethrough = true;
/**
* The colors or color of the arced lines.
* Use HTML hex notation with preceding # sign, and separate each value with a comma.
* This should be similar to your font color for single color images.
*
* @var string
*/
var $arc_line_colors = "#8080ff";
/**
* Full path to the WAV files to use to make the audio files, include trailing /.
* Name Files [A-Z0-9].wav
*
* @since 1.0.1
* @var string
*/
var $audio_path = './audio/';
//END USER CONFIGURATION
//There should be no need to edit below unless you really know what you are doing.
/**
* The gd image resource.
*
* @access private
* @var resource
*/
var $im;
/**
* The background image resource
*
* @access private
* @var resource
*/
var $bgimg;
/**
* The code generated by the script
*
* @access private
* @var string
*/
var $code;
/**
* The code that was entered by the user
*
* @access private
* @var string
*/
var $code_entered;
/**
* Whether or not the correct code was entered
*
* @access private
* @var boolean
*/
var $correct_code;
/**
* Class constructor.
* Because the class uses sessions, this will attempt to start a session if there is no previous one.
* If you do not start a session before calling the class, the constructor must be called before any
* output is sent to the browser.
*
* <code>
* $securimage = new Securimage();
* </code>
*
*/
function Securimage()
{
if ( session_id() == '' ) { // no session has been started yet, which is needed for validation
session_start();
}
}
/**
* Generate a code and output the image to the browser.
*
* <code>
* <?php
* include 'securimage.php';
* $securimage = new Securimage();
* $securimage->show('bg.jpg');
* ?>
* </code>
*
* @param string $background_image The path to an image to use as the background for the CAPTCHA
*/
function show($background_image = "")
{
if($background_image != "" && is_readable($background_image)) {
$this->bgimg = $background_image;
}
$this->doImage();
}
/**
* Validate the code entered by the user.
*
* <code>
* $code = $_POST['code'];
* if ($securimage->check($code) == false) {
* die("Sorry, the code entered did not match.");
* } else {
* $valid = true;
* }
* </code>
* @param string $code The code the user entered
* @return boolean true if the code was correct, false if not
*/
function check($code)
{
$this->code_entered = $code;
$this->validate();
return $this->correct_code;
}
/**
* Generate and output the image
*
* @access private
*
*/
function doImage()
{
if($this->use_transparent_text == true || $this->bgimg != "") {
$this->im = imagecreatetruecolor($this->image_width, $this->image_height);
$bgcolor = imagecolorallocate($this->im, hexdec(substr($this->image_bg_color, 1, 2)), hexdec(substr($this->image_bg_color, 3, 2)), hexdec(substr($this->image_bg_color, 5, 2)));
imagefilledrectangle($this->im, 0, 0, imagesx($this->im), imagesy($this->im), $bgcolor);
} else { //no transparency
$this->im = imagecreate($this->image_width, $this->image_height);
$bgcolor = imagecolorallocate($this->im, hexdec(substr($this->image_bg_color, 1, 2)), hexdec(substr($this->image_bg_color, 3, 2)), hexdec(substr($this->image_bg_color, 5, 2)));
}
if($this->bgimg != "") { $this->setBackground(); }
$this->createCode();
if (!$this->draw_lines_over_text && $this->draw_lines) $this->drawLines();
$this->drawWord();
if ($this->arc_linethrough == true) $this->arcLines();
if ($this->draw_lines_over_text && $this->draw_lines) $this->drawLines();
$this->output();
}
/**
* Set the background of the CAPTCHA image
*
* @access private
*
*/
function setBackground()
{
$dat = @getimagesize($this->bgimg);
if($dat == false) { return; }
switch($dat[2]) {
case 1: $newim = @imagecreatefromgif($this->bgimg); break;
case 2: $newim = @imagecreatefromjpeg($this->bgimg); break;
case 3: $newim = @imagecreatefrompng($this->bgimg); break;
case 15: $newim = @imagecreatefromwbmp($this->bgimg); break;
case 16: $newim = @imagecreatefromxbm($this->bgimg); break;
default: return;
}
if(!$newim) return;
imagecopy($this->im, $newim, 0, 0, 0, 0, $this->image_width, $this->image_height);
}
/**
* Draw arced lines over the text
*
* @access private
*
*/
function arcLines()
{
$colors = explode(',', $this->arc_line_colors);
imagesetthickness($this->im, 3);
$color = $colors[rand(0, sizeof($colors) - 1)];
$linecolor = imagecolorallocate($this->im, hexdec(substr($color, 1, 2)), hexdec(substr($color, 3, 2)), hexdec(substr($color, 5, 2)));
$xpos = $this->text_x_start + ($this->font_size * 2) + rand(-5, 5);
$width = $this->image_width / 2.66 + rand(3, 10);
$height = $this->font_size * 2.14 - rand(3, 10);
if ( rand(0,100) % 2 == 0 ) {
$start = rand(0,66);
$ypos = $this->image_height / 2 - rand(5, 15);
$xpos += rand(5, 15);
} else {
$start = rand(180, 246);
$ypos = $this->image_height / 2 + rand(5, 15);
}
$end = $start + rand(75, 110);
imagearc($this->im, $xpos, $ypos, $width, $height, $start, $end, $linecolor);
$color = $colors[rand(0, sizeof($colors) - 1)];
$linecolor = imagecolorallocate($this->im, hexdec(substr($color, 1, 2)), hexdec(substr($color, 3, 2)), hexdec(substr($color, 5, 2)));
if ( rand(1,75) % 2 == 0 ) {
$start = rand(45, 111);
$ypos = $this->image_height / 2 - rand(5, 15);
$xpos += rand(5, 15);
} else {
$start = rand(200, 250);
$ypos = $this->image_height / 2 + rand(5, 15);
}
$end = $start + rand(75, 100);
imagearc($this->im, $this->image_width * .75, $ypos, $width, $height, $start, $end, $linecolor);
}
/**
* Draw lines on the image
*
* @access private
*
*/
function drawLines()
{
$linecolor = imagecolorallocate($this->im, hexdec(substr($this->line_color, 1, 2)), hexdec(substr($this->line_color, 3, 2)), hexdec(substr($this->line_color, 5, 2)));
imagesetthickness($this->im, $this->line_thickness);
//vertical lines
for($x = 1; $x < $this->image_width; $x += $this->line_distance) {
imageline($this->im, $x, 0, $x, $this->image_height, $linecolor);
}
//horizontal lines
for($y = 11; $y < $this->image_height; $y += $this->line_distance) {
imageline($this->im, 0, $y, $this->image_width, $y, $linecolor);
}
if ($this->draw_angled_lines == true) {
for ($x = -($this->image_height); $x < $this->image_width; $x += $this->line_distance) {
imageline($this->im, $x, 0, $x + $this->image_height, $this->image_height, $linecolor);
}
for ($x = $this->image_width + $this->image_height; $x > 0; $x -= $this->line_distance) {
imageline($this->im, $x, 0, $x - $this->image_height, $this->image_height, $linecolor);
}
}
}
/**
* Draw the CAPTCHA code over the image
*
* @access private
*
*/
function drawWord()
{
if ($this->use_gd_font == true) {
if (!is_int($this->gd_font_file)) { //is a file name
$font = @imageloadfont($this->gd_font_file);
if ($font == false) {
trigger_error("Failed to load GD Font file {$this->gd_font_file} ", E_USER_WARNING);
return;
}
} else { //gd font identifier

Source for file securimage.php