I was looking for a solution to spam for a contact form and found the code below at
www.html-form-guide.com/contact- … ptcha.html
htlm-contact-form-captcha.php
<?php
$your_email ='yourname@your-website.com';// <<=== update to your email address
session_start();
$errors = '';
$name = '';
$visitor_email = '';
$user_message = '';
if(isset($_POST['submit']))
{
$name = $_POST['name'];
$visitor_email = $_POST['email'];
$user_message = $_POST['message'];
///------------Do Validations-------------
if(empty($name)||empty($visitor_email))
{
$errors .= "\n Name and Email are required fields. ";
}
if(IsInjected($visitor_email))
{
$errors .= "\n Bad email value!";
}
if(empty($_SESSION['6_letters_code'] ) ||
strcasecmp($_SESSION['6_letters_code'], $_POST['6_letters_code']) != 0)
{
//Note: the captcha code is compared case insensitively.
//if you want case sensitive match, update the check above to
// strcmp()
$errors .= "\n The captcha code does not match!";
}
if(empty($errors))
{
//send the email
$to = $your_email;
$subject="New form submission";
$from = $your_email;
$ip = isset($_SERVER['REMOTE_ADDR']) ? $_SERVER['REMOTE_ADDR'] : '';
$body = "A user $name submitted the contact form:\n".
"Name: $name\n".
"Email: $visitor_email \n".
"Message: \n ".
"$user_message\n".
"IP: $ip\n";
$headers = "From: $from \r\n";
$headers .= "Reply-To: $visitor_email \r\n";
mail($to, $subject, $body,$headers);
header('Location: thank-you.html');
}
}
// Function to validate against any email injection attempts
function IsInjected($str)
{
$injections = array('(\n+)',
'(\r+)',
'(\t+)',
'(%0A+)',
'(%0D+)',
'(%08+)',
'(%09+)'
);
$inject = join('|', $injections);
$inject = "/$inject/i";
if(preg_match($inject,$str))
{
return true;
}
else
{
return false;
}
}
?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Contact Us</title>
<!-- define some style elements-->
<style>
label,a, body
{
font-family : Arial, Helvetica, sans-serif;
font-size : 12px;
}
.err
{
font-family : Verdana, Helvetica, sans-serif;
font-size : 12px;
color: red;
}
</style>
<!-- a helper script for vaidating the form-->
<script language="JavaScript" src="scripts/gen_validatorv31.js" type="text/javascript"></script>
</head>
<body>
<?php
if(!empty($errors)){
echo "<p class='err'>".nl2br($errors)."</p>";
}
?>
<div id='contact_form_errorloc' class='err'></div>
<form method="POST" name="contact_form"
action="<?php echo htmlentities($_SERVER['PHP_SELF']); ?>">
<p>
<label for='name'>Name: </label><br>
<input type="text" name="name" value='<?php echo htmlentities($name) ?>'>
</p>
<p>
<label for='email'>Email: </label><br>
<input type="text" name="email" value='<?php echo htmlentities($visitor_email) ?>'>
</p>
<p>
<label for='message'>Message:</label> <br>
<textarea name="message" rows=8 cols=30><?php echo htmlentities($user_message) ?></textarea>
</p>
<p>
<img src="captcha_code_file.php?rand=<?php echo rand(); ?>" id='captchaimg' ><br>
<label for='message'>Enter the code above here :</label><br>
<input id="6_letters_code" name="6_letters_code" type="text"><br>
<small>Can't read the image? click <a href='javascript: refreshCaptcha();'>here</a> to refresh</small>
</p>
<input type="submit" value="Submit" name='submit'>
</form>
<script language="JavaScript">
// Code for validating the form
// Visit http://www.javascript-coder.com/html-form/javascript-form-validation.phtml
// for details
var frmvalidator = new Validator("contact_form");
//remove the following two lines if you like error message box popups
frmvalidator.EnableOnPageErrorDisplaySingleBox();
frmvalidator.EnableMsgsTogether();
frmvalidator.addValidation("name","req","Please provide your name");
frmvalidator.addValidation("email","req","Please provide your email");
frmvalidator.addValidation("email","email","Please enter a valid email address");
</script>
<script language='JavaScript' type='text/javascript'>
function refreshCaptcha()
{
var img = document.images['captchaimg'];
img.src = img.src.substring(0,img.src.lastIndexOf("?"))+"?rand="+Math.random()*1000;
}
</script>
</body>
</html>
<?php
/*
*
* this code is based on captcha code by Simon Jarvis
* http://www.white-hat-web-design.co.uk/articles/php-captcha.php
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details:
* http://www.gnu.org/licenses/gpl.html
*/
session_start();
//Settings: You can customize the captcha here
$image_width = 120;
$image_height = 40;
$characters_on_image = 6;
$font = './monofont.ttf';
//The characters that can be used in the CAPTCHA code.
//avoid confusing characters (l 1 and i for example)
$possible_letters = '23456789bcdfghjkmnpqrstvwxyz';
$random_dots = 0;
$random_lines = 20;
$captcha_text_color="0x142864";
$captcha_noice_color = "0x142864";
$code = '';
$i = 0;
while ($i < $characters_on_image) {
$code .= substr($possible_letters, mt_rand(0, strlen($possible_letters)-1), 1);
$i++;
}
$font_size = $image_height * 0.75;
$image = @imagecreate($image_width, $image_height);
/* setting the background, text and noise colours here */
$background_color = imagecolorallocate($image, 255, 255, 255);
$arr_text_color = hexrgb($captcha_text_color);
$text_color = imagecolorallocate($image, $arr_text_color['red'],
$arr_text_color['green'], $arr_text_color['blue']);
$arr_noice_color = hexrgb($captcha_noice_color);
$image_noise_color = imagecolorallocate($image, $arr_noice_color['red'],
$arr_noice_color['green'], $arr_noice_color['blue']);
/* generating the dots randomly in background */
for( $i=0; $i<$random_dots; $i++ ) {
imagefilledellipse($image, mt_rand(0,$image_width),
mt_rand(0,$image_height), 2, 3, $image_noise_color);
}
/* generating lines randomly in background of image */
for( $i=0; $i<$random_lines; $i++ ) {
imageline($image, mt_rand(0,$image_width), mt_rand(0,$image_height),
mt_rand(0,$image_width), mt_rand(0,$image_height), $image_noise_color);
}
/* create a text box and add 6 letters code in it */
$textbox = imagettfbbox($font_size, 0, $font, $code);
$x = ($image_width - $textbox[4])/2;
$y = ($image_height - $textbox[5])/2;
imagettftext($image, $font_size, 0, $x, $y, $text_color, $font , $code);
/* Show captcha image in the page html page */
header('Content-Type: image/jpeg');// defining the image type to be shown in browser widow
imagejpeg($image);//showing the image
imagedestroy($image);//destroying the image instance
$_SESSION['6_letters_code'] = $code;
function hexrgb ($hexstr)
{
$int = hexdec($hexstr);
return array("red" => 0xFF & ($int >> 0x10),
"green" => 0xFF & ($int >> 0x8),
"blue" => 0xFF & $int);
}
?>
