<?php

# Copyright by Kruglov Sergei, 2006, 2007, 2008
# www.captcha.ru, www.kruglov.ru

@error_reporting(E_ALL ^ E_NOTICE);
@ini_set('display_errors', true);
@ini_set('html_errors', false);
@ini_set('error_reporting', E_ALL ^ E_NOTICE);

function clean_url($url)
{
	if( $url == "" )
		return;
	
	$url = strtolower($url);
	$url = str_replace('http://', '',$url);
	$url = str_replace("https://", "", $url);
	$url = str_replace("www.",    "", $url);
	$url = explode('/', $url);
	$url = $url[0];
	
	return $url;
}

if (clean_url($_SERVER['HTTP_REFERER']) != clean_url($_SERVER['HTTP_HOST']))
{
	@include '../../../logs/save_log.php';
	exit ( "Error, wrong way to file.<br><a href=\"/\">Go to main</a>." );
}

class KCAPTCHA {

    PRIVATE $alphabet = "0123456789abcdefghijklmnopqrstuvwxyz";
    PRIVATE $allowed_symbols = "23456789abcdeghkmnpqsuvxyz";
    PRIVATE $fontsdir = 'fonts';
    PRIVATE $length_min = 5;
    PRIVATE $length_max = 6;
    PRIVATE $length = 0;
    PRIVATE $width = 120;
    PRIVATE $height = 60;
    PRIVATE $fluctuation_amplitude = 5;
    PRIVATE $no_spaces = true;
    PRIVATE $show_credits = true;
    PRIVATE $credits = 'LogicBoard.ru';
    PRIVATE $jpeg_quality = 90;
    PUBLIC $keystring = "";
    
    function getKeyString()
    {
       $length = mt_rand( $this->length_min, $this->length_max );
       $this->length = $length;
       
	   $this->keystring = "";
	   for($i=0;$i<$length;$i++)
       {
	       $this->keystring .= $this->allowed_symbols{mt_rand(0,strlen($this->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;
    }
    
	function getImage()
    {
        $foreground_color = array(mt_rand(0,100), mt_rand(0,100), mt_rand(0,100));
        $background_color = array(mt_rand(200,255), mt_rand(200,255), mt_rand(200,255));
        
		$fonts = array();
		$fontsdir_absolute = dirname(__FILE__).'/'.$this->fontsdir;
        
		if ($handle = opendir($fontsdir_absolute))
        {
			while (false !== ($file = readdir($handle)))
            {
				if (preg_match('/\.png$/i', $file))
					$fonts[]=$fontsdir_absolute.'/'.$file;
			}
		    closedir($handle);
		}	
       	
		$alphabet_length=strlen($this->alphabet);
		
		do{
			$font_file=$fonts[mt_rand(0, count($fonts)-1)];
			$font=imagecreatefrompng($font_file);
			imagealphablending($font, true);
			$fontfile_width=imagesx($font);
			$fontfile_height=imagesy($font)-1;
			$font_metrics=array();
			$symbol=0;
			$reading_symbol=false;

			// loading font
			for($i=0;$i<$fontfile_width && $symbol<$alphabet_length;$i++){
				$transparent = (imagecolorat($font, $i, 0) >> 24) == 127;

				if(!$reading_symbol && !$transparent){
					$font_metrics[$this->alphabet{$symbol}]=array('start'=>$i);
					$reading_symbol=true;
					continue;
				}

				if($reading_symbol && $transparent){
					$font_metrics[$this->alphabet{$symbol}]['end']=$i;
					$reading_symbol=false;
					$symbol++;
					continue;
				}
			}

			$img=imagecreatetruecolor($this->width, $this->height);
			imagealphablending($img, true);
			$white=imagecolorallocate($img, 255, 255, 255);
			$black=imagecolorallocate($img, 0, 0, 0);

			imagefilledrectangle($img, 0, 0, $this->width-1, $this->height-1, $white);

			// draw text
			$x=1;
			for($i=0;$i<$this->length;$i++){
				$m=$font_metrics[$this->keystring{$i}];

				$y=mt_rand(-$this->fluctuation_amplitude, $this->fluctuation_amplitude)+($this->height-$fontfile_height)/2+2;

				if($this->no_spaces){
					$shift=0;
					if($i>0){
						$shift=10000;
						for($sy=7;$sy<$fontfile_height-20;$sy+=1){
							for($sx=$m['start']-1;$sx<$m['end'];$sx+=1){
				        		$rgb=imagecolorat($font, $sx, $sy);
				        		$opacity=$rgb>>24;
								if($opacity<127){
									$left=$sx-$m['start']+$x;
									$py=$sy+$y;
									if($py>$this->height) break;
									for($px=min($left,$this->width-1);$px>$left-12 && $px>=0;$px-=1){
						        		$color=imagecolorat($img, $px, $py) & 0xff;
										if($color+$opacity<190){
											if($shift>$left-$px){
												$shift=$left-$px;
											}
											break;
										}
									}
									break;
								}
							}
						}
						if($shift==10000){
							$shift=mt_rand(4,6);
						}

					}
				}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($x>=$this->width-10); // while not fit in canvas

		$center=$x/2;

		// credits. To remove, see configuration file
		$img2=imagecreatetruecolor($this->width, $this->height+($this->show_credits?12:0));
		$foreground=imagecolorallocate($img2, $foreground_color[0], $foreground_color[1], $foreground_color[2]);
		$background=imagecolorallocate($img2, $background_color[0], $background_color[1], $background_color[2]);
		imagefilledrectangle($img2, 0, 0, $this->width-1, $this->height-1, $background);		
		imagefilledrectangle($img2, 0, $this->height, $this->width-1, $this->height+12, $foreground);
		$credits=empty($this->credits)?$_SERVER['HTTP_HOST']:$this->credits;
		imagestring($img2, 2, $this->width/2-imagefontwidth(2)*strlen($credits)/2, $this->height-2, $credits, $background);

		// 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
		$rand9=mt_rand(330,420)/110;
		$rand10=mt_rand(330,450)/110;

		//wave distortion

		for($x=0;$x<$this->width;$x++){
			for($y=0;$y<$this->height;$y++){
				$sx=$x+(sin($x*$rand1+$rand5)+sin($y*$rand3+$rand6))*$rand9-$this->width/2+$center+1;
				$sy=$y+(sin($x*$rand2+$rand7)+sin($y*$rand4+$rand8))*$rand10;

				if($sx<0 || $sy<0 || $sx>=$this->width-1 || $sy>=$this->height-1){
					continue;
				}else{
					$color=imagecolorat($img, $sx, $sy) & 0xFF;
					$color_x=imagecolorat($img, $sx+1, $sy) & 0xFF;
					$color_y=imagecolorat($img, $sx, $sy+1) & 0xFF;
					$color_xy=imagecolorat($img, $sx+1, $sy+1) & 0xFF;
				}

				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{
					$frsx=$sx-floor($sx);
					$frsy=$sy-floor($sy);
					$frsx1=1-$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];
				}

				imagesetpixel($img2, $x, $y, imagecolorallocate($img2, $newred, $newgreen, $newblue));
			}
		}
		
		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('Pragma: no-cache');
		
		if(function_exists("imagejpeg")){
			header("Content-Type: image/jpeg");
			imagejpeg($img2, null, $this->jpeg_quality);
		}else if(function_exists("imagegif")){
			header("Content-Type: image/gif");
			imagegif($img2);
		}else if(function_exists("imagepng")){
			header("Content-Type: image/x-png");
			imagepng($img2);
		}
	}
}

session_start();

$captcha = new KCAPTCHA();
$captcha->getKeyString();
$_SESSION['captcha_keystring'] = $captcha->keystring;
$captcha->getImage();

?>