[Galerie] Réalisation de CAPTCHAs

<?php
header ("Content-type: image/png");

$image = imagecreate(80,60);
$p0 = $_GET['cap0'];
$p1 = $_GET['cap1'];
$p2 = $_GET['cap2'];
$p3 = $_GET['cap3'];
$p4 = $_GET['cap4'];
$p5 = $_GET['cap5'];
$p6 = $_GET['cap6'];
$p7 = $_GET['cap7'];

$pos_0 = mt_rand (1,40);
$pos_1 = mt_rand (1,40);
$pos_2 = mt_rand (1,40);
$pos_3 = mt_rand (1,40);
$pos_4 = mt_rand (1,40);
$pos_5 = mt_rand (1,40);
$pos_6 = mt_rand (1,40);
$pos_7 = mt_rand (1,40);

$orange = imagecolorallocate($image, 255, 128, 0);
$bleu = imagecolorallocate($image, 0, 0, 255);
$bleuclair = imagecolorallocate($image, 156, 227, 254);
$noir = imagecolorallocate($image, 0, 0, 0);
$blanc = imagecolorallocate($image, 255, 255, 255);

imagestring($image, 3, 1, $pos_0,$p0 , $blanc);
imagestring($image, 3, 10, $pos_1,$p1 , $blanc);
imagestring($image, 3, 20, $pos_2,$p2 , $blanc);
imagestring($image, 3, 30, $pos_3,$p3 , $blanc);
imagestring($image, 3, 40, $pos_4,$p4 , $blanc);
imagestring($image, 3, 50, $pos_5,$p5 , $blanc);
imagestring($image, 3, 60, $pos_6,$p6 , $blanc);
imagestring($image, 3, 70, $pos_7,$p7 , $blanc);


imagepng($image);
?>

<?php
function pass($nbr, $C=TRUE, $Lp=FALSE, $Lg=FALSE, $S=FALSE)
{
        $chaine = '';
        if ($C == 1) $chaine .=  "0123456789";
        if ($Lp == 1) $chaine .=  "abcdefghijklmnopqrstuvwyz";
        if ($Lg == 1) $chaine .=  "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        if ($S == 1) $chaine .=  "#(-_)=\|/*$:;,&?!§µ{}][";
        $pass = '';
        for($i=0; $i<$nbr; $i++) { $pass .= $chaine[rand()%strlen($chaine)]; }
        return $pass;
}

$pass0 = strtolower(pass(1,true,true,true));
$pass1 = strtolower(pass(1,true,true,true));
$pass2 = strtolower(pass(1,true,true,true));
$pass3 = strtolower(pass(1,true,true,true));
$pass4 = strtolower(pass(1,true,true,true));
$pass5 = strtolower(pass(1,true,true,true));
$pass6 = strtolower(pass(1,true,true,true));
$pass7 = strtolower(pass(1,true,true,true));
?>
<img src="captcha.php?cap0=<?php echo $pass0;?>&amp;cap1=<?php echo $pass1;?>&amp;cap2=<?php echo $pass2;?>&amp;cap3=<?php echo $pass3;?>&amp;cap4=<?php echo $pass4;?>&amp;cap5=<?php echo $pass5;?>&amp;cap6=<?php echo $pass6;?>&amp;cap7=<?php echo $pass7;?>"/><br>