Subversion-Projekte lars-tiefland.prado

<?php

/**

 * CAPTCHA generator script.

 *

 * @author Qiang Xue <qiang.xue@gmail.com>

 * @link http://www.pradosoft.com/

 * @copyright Copyright © 2005-2008 PradoSoft

 * @license http://www.pradosoft.com/license/

 * @version $Id: captcha.php 2541 2008-10-21 15:05:13Z qiang.xue $

 * @package System.Web.UI.WebControls.assets

 */

define('THEME_OPAQUE_BACKGROUND',0x0001);

define('THEME_NOISY_BACKGROUND',0x0002);

define('THEME_HAS_GRID',0x0004);

define('THEME_HAS_SCRIBBLE',0x0008);

define('THEME_MORPH_BACKGROUND',0x0010);

define('THEME_SHADOWED_TEXT',0x0020);

require_once(dirname(__FILE__).'/captcha_key.php');

$token='error';

$theme=0;

if(isset($_GET['options']))

{

	$str=base64_decode($_GET['options']);

	if(strlen($str)>32)

	{

		$hash=substr($str,0,32);

		$str=substr($str,32);

		if(md5($privateKey.$str)===$hash)

		{

			$options=unserialize($str);

			$publicKey=$options['publicKey'];

			$tokenLength=$options['tokenLength'];

			$caseSensitive=$options['caseSensitive'];

			$alphabet=$options['alphabet'];

			$fontSize=$options['fontSize'];

			$theme=$options['theme'];

			if(($randomSeed=$options['randomSeed'])>0)

				srand($randomSeed);

			else

				srand((int)(microtime()*1000000));

			$token=generateToken($publicKey,$privateKey,$alphabet,$tokenLength,$caseSensitive);

		}

	}

}

displayToken($token,$fontSize,$theme);

function generateToken($publicKey,$privateKey,$alphabet,$tokenLength,$caseSensitive)

{

	$token=substr(hash2string(md5($publicKey.$privateKey),$alphabet).hash2string(md5($privateKey.$publicKey),$alphabet),0,$tokenLength);

	return $caseSensitive?$token:strtoupper($token);

}

function hash2string($hex,$alphabet)

{

	if(strlen($alphabet)<2)

		$alphabet='234578adefhijmnrtABDEFGHJLMNRT';

	$hexLength=strlen($hex);

	$base=strlen($alphabet);

	$result='';

	for($i=0;$i<$hexLength;$i+=6)

	{

		$number=hexdec(substr($hex,$i,6));

		while($number)

		{

			$result.=$alphabet[$number%$base];

			$number=floor($number/$base);

		}

	}

	return $result;

}

function displayToken($token,$fontSize,$theme)

{

	if(($fontSize=(int)$fontSize)<22)

		$fontSize=22;

	if($fontSize>100)

		$fontSize=100;

	$length=strlen($token);

	$padding=10;

	$fontWidth=$fontSize;

	$fontHeight=floor($fontWidth*1.5);

	$width=$fontWidth*$length+$padding*2;

	$height=$fontHeight;

	$image=imagecreatetruecolor($width,$height);

	addBackground

	(

		$image, $width, $height,

		$theme&THEME_OPAQUE_BACKGROUND,

		$theme&THEME_NOISY_BACKGROUND,

		$theme&THEME_HAS_GRID,

		$theme&THEME_HAS_SCRIBBLE,

		$theme&THEME_MORPH_BACKGROUND

	);

	$font=dirname(__FILE__).DIRECTORY_SEPARATOR.'verase.ttf';

	if(function_exists('imagefilter'))

    	imagefilter($image,IMG_FILTER_GAUSSIAN_BLUR);

	$hasShadow=($theme&THEME_SHADOWED_TEXT);

    for($i=0;$i<$length;$i++)

	{

        $color=imagecolorallocate($image,rand(150,220),rand(150,220),rand(150,220));

        $size=rand($fontWidth-10,$fontWidth);

        $angle=rand(-30,30);

        $x=$padding+$i*$fontWidth;

        $y=rand($fontHeight-15,$fontHeight-10);

        imagettftext($image,$size,$angle,$x,$y,$color,$font,$token[$i]);

        if($hasShadow)

        	imagettftext($image,$size,$angle,$x+2,$y+2,$color,$font,$token[$i]);

        imagecolordeallocate($image,$color);

    }

	imagepng($image);

	imagedestroy($image);

}

function addBackground($image,$width,$height,$opaque,$noisy,$hasGrid,$hasScribble,$morph)

{

	$background=imagecreatetruecolor($width*2,$height*2);

	$white=imagecolorallocate($background,255,255,255);

	imagefill($background,0,0,$white);

	if($opaque)

		imagefill($background,0,0,imagecolorallocate($background,100,100,100));

	if($noisy)

		addNoise($background,$width*2,$height*2);

	if($hasGrid)

		addGrid($background,$width*2,$height*2);

	if($hasScribble)

		addScribble($background,$width*2,$height*2);

	if($morph)

		morphImage($background,$width*2,$height*2);

	imagecopy($image,$background,0,0,30,30,$width,$height);

	if(!$opaque)

		imagecolortransparent($image,$white);

}

function addNoise($image,$width,$height)

{

	for($x=0;$x<$width;++$x)

	{

		for($y=0;$y<$height;++$y)

		{

			if(rand(0,100)<25)

			{

				$color=imagecolorallocate($image,rand(150,220),rand(150,220),rand(150,220));

				imagesetpixel($image,$x,$y,$color);

	            imagecolordeallocate($image,$color);

	        }

		}

	}

}

function addGrid($image,$width,$height)

{

	for($i=0;$i<$width;$i+=rand(15,25))

	{

		imagesetthickness($image,rand(2,6));

		$color=imagecolorallocate($image,rand(100,180),rand(100,180),rand(100,180));

		imageline($image,$i+rand(-10,20),0,$i+rand(-10,20),$height,$color);

		imagecolordeallocate($image,$color);

	}

	for($i=0;$i<$height;$i+=rand(15,25))

	{

		imagesetthickness($image,rand(2,6));

		$color=imagecolorallocate($image,rand(100,180),rand(100,180),rand(100,180));

		imageline($image,0,$i+rand(-10,20),$width,$i+rand(-10,20),$color);

		imagecolordeallocate($image,$color);

	}

}

function addScribble($image,$width,$height)

{

	for($i=0;$i<8;$i++)

	{

		$color=imagecolorallocate($image,rand(100,180),rand(100,180),rand(100,180));

		$points=array();

		for($j=1;$j<rand(5,10);$j++)

		{

			$points[]=rand(2*(20*($i+1)),2*(50*($i+1)));

			$points[]=rand(30,$height+30);

		}

		imagesetthickness($image,rand(2,6));

		imagepolygon($image,$points,intval(sizeof($points)/2),$color);

		imagecolordeallocate($image,$color);

	}

}

function morphImage($image,$width,$height)

{

	$tempImage=imagecreatetruecolor($width,$height);

	$chunk=rand(1,5);

	for($x=$y=0;$x<$width;$x+=$chunk)

	{

		$chunk=rand(1,5);

		$y+=rand(-1,1);

		if($y>=$height)	$y=$height-5;

		if($y<0) $y=5;

		imagecopy($tempImage,$image,$x,0,$x,$y,$chunk,$height);

	}

	for($x=$y=0;$y<$height;$y+=$chunk)

	{

		$chunk=rand(1,5);

		$x+=rand(-1,1);

		if($x>=$width)	$x=$width-5;

		if($x<0) $x=5;

		imagecopy($image,$tempImage,$x,$y,0,$y,$width,$chunk);

	}

}