<?php
# KCAPTCHA PROJECT VERSION 2.0
# Automatic test to tell computers and humans apart
# Copyright by Kruglov Sergei, 2006, 2007, 2008, 2011
# www.captcha.ru, www.kruglov.ru
# System requirements: PHP 4.0.6+ w/ GD
# KCAPTCHA is a free software. You can freely use it for developing own site or software.
# If you use this software as a part of own sofware, you must leave copyright notices intact or add KCAPTCHA copyright notices to own.
# As a default configuration, KCAPTCHA has a small credits text at bottom of CAPTCHA image.
# You can remove it, but I would be pleased if you left it. ;)
# See kcaptcha_config.php for customization
class KCAPTCHA{
// generates keystring and image
function KCAPTCHA(){
# KCAPTCHA configuration file
$alphabet = "0123456789abcdefghijklmnopqrstuvwxyz"; # do not change without changing font files!
# symbols used to draw CAPTCHA
//$allowed_symbols = "0123456789"; #digits
//$allowed_symbols = "23456789abcdegkmnpqsuvxyz"; #alphabet without similar symbols (o=0, 1=l, i=j, t=f)
$allowed_symbols = "23456789abcdegikpqsvxyz"; #alphabet without similar symbols (o=0, 1=l, i=j, t=f)
# folder with fonts
$fontsdir = 'fonts';
# CAPTCHA string length
$length = mt_rand(5,7); # random 5 or 6 or 7 //$length = 6;
# CAPTCHA image size (you do not need to change it, this parameters is optimal)
$width = 160;
$height = 80;
# symbol's vertical fluctuation amplitude
$fluctuation_amplitude = 8;
#noise
//$white_noise_density=0; // no white noise
$white_noise_density=1/6;
//$black_noise_density=0; // no black noise
$black_noise_density=1/30;
# increase safety by prevention of spaces between symbols
$no_spaces = true;
# show credits
$show_credits = true; # set to false to remove credits line. Credits adds 12 pixels to image height
$credits = 'www.captcha.ru'; # if empty, HTTP_HOST will be shown
# CAPTCHA image colors (RGB, 0-255)
//$foreground_color = array(0, 0, 0);
//$background_color = array(220, 230, 255);
# JPEG quality of CAPTCHA image (bigger is better quality, but larger file size)
$jpeg_quality = 90;
//require(dirname(__FILE__).'/kcaptcha_config.php');
$fontsdir_absolute=dirname(__FILE__).'/'.$fontsdir; if ($handle = opendir($fontsdir_absolute)) { while (false !== ($file = readdir($handle))) { $fonts[]=$fontsdir_absolute.'/'.$file;
}
}
}
$alphabet_length=strlen($alphabet);
do{
// generating random keystring
while(true){
$this->keystring='';
for($i=0;$i<$length;$i++){
$this->keystring.=$allowed_symbols{mt_rand(0,strlen($allowed_symbols)-1)}; }
if(!preg_match('/cp|cb|ck|c6|c9|rn|rm|mm|co|do|cl|db|qp|qb|dp|ww/', $this->keystring)) break; }
unset($_SESSION['captcha']); $_SESSION['captcha'] = $this->keystring;
$symbol=0;
$reading_symbol=false;
// loading font
for($i=0;$i<$fontfile_width && $symbol<$alphabet_length;$i++){
if(!$reading_symbol && !$transparent){
$font_metrics[$alphabet{$symbol}]=array('start'=>$i); $reading_symbol=true;
continue;
}
if($reading_symbol && $transparent){
$font_metrics[$alphabet{$symbol}]['end']=$i;
$reading_symbol=false;
$symbol++;
continue;
}
}
// draw text
$x=1;
if($odd==0) $odd=-1;
for($i=0;$i<$length;$i++){
$m=$font_metrics[$this->keystring{$i}];
$y=(($i%2)*$fluctuation_amplitude - $fluctuation_amplitude/2)*$odd
+ ($height-$fontfile_height)/2;
if($no_spaces){
$shift=0;
if($i>0){
$shift=10000;
for($sy=3;$sy<$fontfile_height-10;$sy+=1){
for($sx=$m['start']-1;$sx<$m['end'];$sx+=1){
$opacity=$rgb>>24;
if($opacity<127){
$left=$sx-$m['start']+$x;
$py=$sy+$y;
if($py>$height) break;
for($px=min($left,$width-1);$px>$left-200 && $px>=0;$px-=1){ if($color+$opacity<170){ // 170 - threshold
if($shift>$left-$px){
$shift=$left-$px;
}
break;
}
}
break;
}
}
}
if($shift==10000){
}
}
}else{
$shift=1;
}
imagecopy($img, $font, $x-$shift, $y, $m['start'], 1, $m['end']-$m['start'], $fontfile_height); $x+=$m['end']-$m['start']-$shift;
}
}while($x>=$width-10); // while not fit in canvas
//noise
for($i=0;$i<(($height-30)*$x)*$white_noise_density;$i++){
}
for($i=0;$i<(($height-30)*$x)*$black_noise_density;$i++){
}
$center=$x/2;
// credits. To remove, see configuration file
$foreground=imagecolorallocate($img2, $foreground_color[0], $foreground_color[1], $foreground_color[2]); $background=imagecolorallocate($img2, $background_color[0], $background_color[1], $background_color[2]); $credits=empty($credits)?$_SERVER['HTTP_HOST']:$credits;
// periods
$rand1=mt_rand(750000,1200000)/10000000; $rand2=mt_rand(750000,1200000)/10000000; $rand3=mt_rand(750000,1200000)/10000000; $rand4=mt_rand(750000,1200000)/10000000; // phases
$rand5=mt_rand(0,31415926)/10000000; $rand6=mt_rand(0,31415926)/10000000; $rand7=mt_rand(0,31415926)/10000000; $rand8=mt_rand(0,31415926)/10000000; // amplitudes
//wave distortion
for($x=0;$x<$width;$x++){
for($y=0;$y<$height;$y++){
$sx=$x+(sin($x*$rand1+$rand5)+sin($y*$rand3+$rand6))*$rand9-$width/2+$center+1; $sy=$y+(sin($x*$rand2+$rand7)+sin($y*$rand4+$rand8))*$rand10;
if($sx<0 || $sy<0 || $sx>=$width-1 || $sy>=$height-1){
continue;
}else{
}
if($color==255 && $color_x==255 && $color_y==255 && $color_xy==255){
continue;
}else if($color==0 && $color_x==0 && $color_y==0 && $color_xy==0){
$newred=$foreground_color[0];
$newgreen=$foreground_color[1];
$newblue=$foreground_color[2];
}else{
$frsx1=1-$frsx;
$frsy1=1-$frsy;
$newcolor=(
$color*$frsx1*$frsy1+
$color_x*$frsx*$frsy1+
$color_y*$frsx1*$frsy+
$color_xy*$frsx*$frsy);
if($newcolor>255) $newcolor=255;
$newcolor=$newcolor/255;
$newcolor0=1-$newcolor;
$newred=$newcolor0*$foreground_color[0]+$newcolor*$background_color[0];
$newgreen=$newcolor0*$foreground_color[1]+$newcolor*$background_color[1];
$newblue=$newcolor0*$foreground_color[2]+$newcolor*$background_color[2];
}
}
}
header('Expires: Mon, 26 Jul 1997 05:00:00 GMT'); header('Cache-Control: no-store, no-cache, must-revalidate'); header('Cache-Control: post-check=0, pre-check=0', FALSE); header("Content-Type: image/jpeg"); header("Content-Type: image/gif"); header("Content-Type: image/x-png"); }
}
// returns keystring
function getKeyString(){
return $this->keystring;
}
}
?>