255) { return 255; }
if($a<0) { return 0; }
return $a;
}
function randString($length, $charset='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+=')
{
$str = '';
$count = strlen($charset);
while ($length--) {
$str .= $charset[rand(0, $count-1)];
}
return $str;
}
function generateCaptchaHash() {
global $config;
$lines = getImages();
$pick = pickImage($lines);
$enctext = $pick . ",," . time() . ",," . $_SERVER["REMOTE_ADDR"] . ",," . randString(12);
$converter = new Encryption;
return $converter->encode($config["imgcaptcha_key"],$enctext);
}
function ic_verifyHash($enctext, $output) {
global $config;
//print "VERIFY: " . $enctext . " " . $output . "
";
$converter = new Encryption;
$dectext = explode(",,",$converter->decode($config["imgcaptcha_key"],$enctext));
if(count($dectext)<4) return true;
$lines = getImages();
$pick = $dectext[0];
$time = time()-$dectext[1];
if($time>$config["imgcaptcha_time_limit"]) return true;
$lp = $lines[$pick];
for($i=1;$idecode($config["imgcaptcha_key"],$enctext));
if(count($dectext)<=1) return; //SC
$lines = getImages();
return $dectext[0];
}
function generateImage($enctext)
{
global $config;
$lines = getImages();
$pick = getPick($enctext);
if(!isset($lines[$pick])) return; //SC
$src = imagecreatefrompng(getIPath($lines[$pick][0]));
if($src == FALSE) return; //SC
$maxc = 8;
$icw = $config["imgcaptcha_width"];
$ich = $config["imgcaptcha_height"];
$dst = imagecreatetruecolor($icw,$ich);
$srcxm = imagesx($src)-$icw;
$srcym = imagesy($src)-$ich;
$srcx = rand(0,$srcxm-1);
$srcy = rand(0,$srcym-1);
imagecopy($dst,$src,0,0,$srcx,$srcy,$icw,$ich);
// Obfuscation step 1
imagecopymergegray($dst,$dst,0,0,0,0,$icw,$ich,rand(20,45));
// Obfuscation step 1.5
for($i=0;$i<8;$i++) {
$w = rand(5,10); $h = rand(5,10);
$x = rand(0,$icw-1-$w); $y = rand(0,$ich-1-$h);
$x2 = rand(0,$icw-1); $y2 = rand(0,$ich-1);
imagefilledrectangle($dst,$x,$y,$x+$w,$y+$h,imagecolorat($dst,$x2,$y2));
}
for($i=0;$i<5;$i++) {
$w = rand(20,40); $h = rand(20,40);
$x = rand(0,$icw-1-$w); $y = rand(0,$ich-1-$h);
imagecopymergegray($dst,$dst,$x,$y,$x,$y,$w,$h,0);
}
// Obfuscation step 2
for($i=0;$i<$icw*$ich;$i++) {
$x = $i%$icw; $y = $i/$icw;
$c = imagecolorat($dst,$x,$y);
if(rand(0,4) == 2) { $nc = $c ^ rand(0,16777215); }
else { $nc = imagecolorat($dst,rand(0,$icw-1),rand(0,$ich-1)); }
if(rand(18,24)!=21 and $c != 0 and $c != 0xFF00FF)
{
$nc = ncfix(($c&0xFF) + rand(-16,16)) | ncfix((($c>>8)&0xFF) + rand(-8,8))<<8 | ncfix((($c>>16)&0xFF) + rand(-32,32))<<16;
$nc1 = $nc&0xFF ^ ($nc>>8)&0xFF ^ ($nc>>16)&0xFF;
} else {
$nc1 = $nc&0xFF;
if($nc1>($maxc*25)) $nc1 = $nc % ($maxc*25);
}
$nc2 = $nc1 | $nc1<<8 | $nc1<<16;
if(rand(0,1)==0) $nc2=$nc;
imagesetpixel($dst,$x,$y,$nc2);
}
// Obfuscation step 3
for($i=0;$i