Formular mit Validierung:
$errorsucc = '';
if (isset($_POST["captcha_check"])) {
$code = str_decrypt($_POST["captcha_check"]);
if (empty($_POST['captcha_code'])) {
$errorsucc = '<p style="color:red">Please Enter the security code.</p>';
} elseif(!( $code == $_POST['captcha_code'] && !empty($code) )) {
$errorsucc = '<p style="color:red">Incorrect Code Entered.</p>';
} else {
$errorsucc = '<p style = "green">Nice, you entered the correct code.</p>';
}
}
$captcha = new CaptchaCode();
$code = str_encrypt($captcha->generateCode(6));
?>
<html>
<title>Sessionless Captcha</title>
<div style = "background: #e2e2e2; padding: 20px; width: 20%; box-shadow: 5px 5px #ccc;">
<?php echo $errorsucc; ?>
<form name="captchaform" method="post">
<table border="0" cellpadding="4" cellspacing="0">
<tr><td valign="middle" align="left">Security Code:</td>
<td valign="middle" align="left"><img src="captcha_images.php?width=150&height=50&code=<?php echo $code?>" /></td>
</tr>
<tr><td valign="middle" align="left">Enter Code:</td>
<td valign="middle" align="left"><input id="captcha_code" name="captcha_code" style="width:150px" type="text" /></td>
</tr>
<tr><td valign="top" align="left">
</td>
<td valign="top" align="left">
<input border="0" type="submit" value="Submit" />
</td>
</tr>
</table>
<input type="hidden" name="captcha_check" value="<?php echo $code?>" />
</form>
</div>
</html>
Erzeugen Sie Bilder wie jedes andere Captcha:
/* font size will be 75% of the image height */
$font_size = $height * 0.75;
$image = @imagecreate($width, $height) or die('Cannot initialize new GD image stream');
/* set the colours */
$background_color = imagecolorallocate($image, 255, 255, 255);
$text_color = imagecolorallocate($image, 0, 26, 26);
$noise_color = imagecolorallocate($image, 25, 89, 89);
/* generate random dots in background */
for( $i=0; $i<($width*$height)/3; $i++ ) {
imagefilledellipse($image, mt_rand(0,$width), mt_rand(0,$height), 1, 1, $noise_color);
}
/* generate random lines in background */
for( $i=0; $i<($width*$height)/150; $i++ ) {
imageline($image, mt_rand(0,$width), mt_rand(0,$height), mt_rand(0,$width), mt_rand(0,$height), $noise_color);
}
/* create textbox and add text */
$textbox = imagettfbbox($font_size, 0, $this->font, $code) or die('Error in imagettfbbox function');
$x = ($width - $textbox[4])/2;
$y = ($height - $textbox[5])/2;
imagettftext($image, $font_size, 0, $x, $y, $text_color, $this->font , $code) or die('Error in imagettftext function');
/* output captcha image to browser */
header('Content-Type: image/jpeg');
imagejpeg($image);
imagedestroy($image);
Laden Sie die Demodateien über diesen Link herunter: Ein sitzungsloses Captcha in PHP erstellen
