Subversion-Projekte lars-tiefland.prado

<?php
/**
 * CAPTCHA generator script.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.pradosoft.com/
 * @copyright Copyright &copy; 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);
        }
}