Well, you could generate a random string, save it to a php file, then include that file in the captcha.php file and then iterate over that string to get you your image. I've adapted it to do just this (with alphabetic letters too) and here's what i got:
captcha.php
<?php
session_start();
function hex2int($hex) {
return array( 'r' => hexdec(substr($hex, 0, 2)), // 1st pair of digits
'g' => hexdec(substr($hex, 2, 2)), // 2nd pair
'b' => hexdec(substr($hex, 4, 2)) // 3rd pair
);
}
include_once('keyFile.php');
/*
Content: CAPTCHA image
Creator: Mark Cole
License: N/A
Copyright to Cyber-Wars.com
*/
$totalChars = 5;
$backrand = "backCAPTCHAimage" . rand(1, 4) . ".gif";
//$backrand = "backCAPTCHAimage2.gif";
$image = imagecreatefromgif("images/" . $backrand);
//change the image to whatever you want. I included one just in case
$spacing = (imagesx($image) / $totalChars);
//arial = 1.ttf
//masturbator = 2.ttf
//wizardry = 6.ttf
//augie = 4.ttf
//xfiles = 5.ttf
//medusa = 3.ttf
$colors = array('12CBEC', 'C315ED', '67F85D', '0151B7', '229E56', 'BA6DB4', 'E80363', 'F4D658', 'FFFFFF', 'DB2D12', 'A61859', 'A61812', '5EF254', 'ACE338', '21CB14', 'EE9CF1', '29F9FF', 'A1F63F', 'C31D19', 'ABC0E6', '1184CE', 'F71869', 'E0EDCC');
for($i = 0, $totalChars=strlen($key); $i < $totalChars; $i++)
{
$character = $key[$i];
$rand = rand(1,5);
$font = 'Arial'; //$rand . '.pap';
$font_size = rand(20, 35);
$angle = rand(-30, 30);
$rand_keys = array_rand($colors, 2);
$imColor = hex2int($colors[$rand_keys[0]]);
$fontColor = imagecolorallocate($image, $imColor['r'], $imColor['g'], $imColor['b']);
$details = imageftbbox($font_size, $angle, $font, $character, array());
$x = $spacing / 4 + $i * $spacing;
$char_height = $details[2] - $details[5];
$y = imagesy($image) / 2 + $char_height / 4;
imagettftext($image, $font_size, $angle, $x, $y, $fontColor, $font, $character);
}
header("Content-Type: image/gif");
imagegif($image);
?>
val.php
<?php
session_start();
ob_start();
if(!isset($_POST['submit']))
{
$_SESSION['key'] = genRandString();
echo '
<div align="center">
<img src="10341597.captcha.php" alt="security image" />
<form method="post">
<input type="text" name="security" id="security" />
<input type="submit" name="submit" value="Enter" />
</form>
</div>';
}
else
{
$seskey = $_SESSION['key'];
$security = $_POST['security'];
if(strlen($security) <= 0){
echo 'Field must be filled in. =/ idiot';
}
elseif($seskey != $security)
{
echo 'Invalid Security Code<br />';
}
else
{
$newtime = time() + 900;
setcookie("val", "set", "$newtime");
echo '<script type="text/javascript">
<!--
window.location = "intro.php"
//-->
</script>';
}
}
ob_end_flush();
function genRandString($chars=5)
{
$key = '';
$alpha = range('A', 'Z');
for($i=0; $i<$chars; $i++)
{
$alnum = rand(0,1);
if($alnum)
{
$char = rand(0,9);
}
else
{
$char = $alpha[rand(0, 25)];
}
$key .= $char;
}
writeKeyFile($key);
return $key;
}
function writeKeyFile($key)
{
$contents = '<?php
if(substr($_SERVER[\'SCRIPT_FILENAME\'], -11) == \'keyFile.php\')
{
header(\'Location: 10341597.val.php\');
}
$key = \''.$key.'\';
?>';
$fp = @fopen('keyFile.php', 'w+');
fwrite($fp, $contents);
fclose($fp);
}
?>
