<?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. ;)

/*
=====================================================
 DataLife Engine v10.3
-----------------------------------------------------
 Persian support site: http://datalifeengine.ir
-----------------------------------------------------
 Copyright (c) 2006-2014, All rights reserved.
=====================================================
 File name: antibot.php
=====================================================
*/

function clean_url ($url) {

  if ($url == '') return;

  $url = str_replace("http://", "", strtolower($url));
  $url = str_replace("https://", "", $url );
  if (substr($url, 0, 4) == 'www.')  $url = substr($url, 4);
  $url = explode('/', $url);
  $url = reset($url);
  $url = explode(':', $url);
  $url = reset($url);

  return $url;
}

if (clean_url($_SERVER['HTTP_REFERER']) != clean_url($_SERVER['HTTP_HOST'])) die("Hacking attempt!");

class KCAPTCHA{

	// generates keystring and image
	function KCAPTCHA(){

		$alphabet = "0123456789abcdefghijklmnopqrstuvwxyz"; # do not change without changing font files!
		
		# symbols used to draw CAPTCHA
		//$allowed_symbols = "0123456789"; #digits
		$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;
		
		
		# CAPTCHA image colors (RGB, 0-255)
		//$foreground_color = array(0, 0, 0);
		//$background_color = array(220, 230, 255);
		$foreground_color = array(mt_rand(0,80), mt_rand(0,80), mt_rand(0,80));
		$background_color = array(mt_rand(220,255), mt_rand(220,255), mt_rand(220,255));
		
		# JPEG quality of CAPTCHA image (bigger is better quality, but larger file size)
		$jpeg_quality = 90;
		$fonts=array();
		$fontsdir_absolute=dirname(__FILE__).'/'.$fontsdir;
		if ($handle = opendir($fontsdir_absolute)) {
			while (false !== ($file = readdir($handle))) {
				if (preg_match('/\.png$/i', $file)) {
					$fonts[]=$fontsdir_absolute.'/'.$file;
				}
			}
		    closedir($handle);
		}	
	
		$alphabet_length=strlen($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;
			}
		
			$font_file=$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){
					$font_metrics[$alphabet{$symbol}]=array('start'=>$i);
					$reading_symbol=true;
					continue;
				}

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

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

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

			// draw text
			$x=1;
			$odd=mt_rand(0,1);
			if($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
					+ mt_rand(-round($fluctuation_amplitude/3), round($fluctuation_amplitude/3))
					+ ($height-$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){
				        		$rgb=imagecolorat($font, $sx, $sy);
				        		$opacity=$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){
						        		$color=imagecolorat($img, $px, $py) & 0xff;
										if($color+$opacity<170){ // 170 - threshold
											if($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($x>=$width-10); // while not fit in canvas

		//noise
		$white=imagecolorallocate($font, 255, 255, 255);
		$black=imagecolorallocate($font, 0, 0, 0);
		for($i=0;$i<(($height-30)*$x)*$white_noise_density;$i++){
			imagesetpixel($img, mt_rand(0, $x-1), mt_rand(10, $height-15), $white);
		}
		for($i=0;$i<(($height-30)*$x)*$black_noise_density;$i++){
			imagesetpixel($img, mt_rand(0, $x-1), mt_rand(10, $height-15), $black);
		}

		
		$center=$x/2;

		// credits. To remove, see configuration file
		$img2=imagecreatetruecolor($width, $height);
		$foreground=imagecolorallocate($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, $width-1, $height-1, $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)/100;

		//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{
					$color=imagecolorat($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, $jpeg_quality);
		}else if(function_exists("imagegif")){
			header("Content-Type: image/gif");
			imagegif($img2);
		}else if(function_exists("imagepng")){
			header("Content-Type: image/x-png");
			imagepng($img2);
		}
	}

	// returns keystring
	function getKeyString(){
		return $this->keystring;
	}
}

$domain_cookie = explode (".", clean_url( $_SERVER['HTTP_HOST'] ));
$domain_cookie_count = count($domain_cookie);
$domain_allow_count = -2;

if ( $domain_cookie_count > 2 ) {

	if ( in_array($domain_cookie[$domain_cookie_count-2], array('com', 'net', 'org') )) $domain_allow_count = -3;
	if ( $domain_cookie[$domain_cookie_count-1] == 'ua' ) $domain_allow_count = -3;
	$domain_cookie = array_slice($domain_cookie, $domain_allow_count);
}

$domain_cookie = "." . implode (".", $domain_cookie);

if( ip2long($_SERVER['HTTP_HOST']) != -1 AND ip2long($_SERVER['HTTP_HOST']) !== FALSE ) define( 'DOMAIN', null );
else define( 'DOMAIN', $domain_cookie );

$params = session_get_cookie_params();

if ( DOMAIN ) $params['domain'] = DOMAIN;

if( version_compare(PHP_VERSION, '5.2', '<') ) {
		
	session_set_cookie_params($params['lifetime'], "/", $params['domain'], $params['secure']);

} else {
	
	session_set_cookie_params($params['lifetime'], "/", $params['domain'], $params['secure'], true);
	
}	

@session_start();

$im = new KCAPTCHA();

$_SESSION['sec_code_session'] = $im->getKeyString();

?>