captcha i min kontaktform

<?php

session_start();

require 'lib/Database.php';
require 'inc/Top.inc';

$self = $_SERVER['PHP_SELF'];

if ($_SERVER['REQUEST_METHOD'] == 'POST')
{
    $dbo = new \Application\Model\Database();

    // prepare form data
    $_POST = array_map('addslashes', $_POST);
    $_POST = array_map('trim', $_POST);
    extract($_POST);

    // TODO: Validate data (make sure form is completely & correctly filled)
    $form_valid = (
        isset($firstname) &&
        isset($lastname) &&
        isset($email) &&
        isset($phone) &&
        isset($mail_message)
    );

    $errors = [];

    if ($form_valid && count($errors) == 0) {
        $ip = getenv('REMOTE_ADDR');
        $seed = time();
        $enc1 = md5($_FILES['file1']['tmp_name']) . '.dat';
        $enc2 = md5($_FILES['file2']['tmp_name']) . '.dat';
        $enc3 = md5($_FILES['file3']['tmp_name']) . '.dat';
        $enc4 = md5($_FILES['file4']['tmp_name']) . '.dat';
        $enc5 = md5($_FILES['file5']['tmp_name']) . '.dat';
        $q = $dbo->Query("insert into Messages (
            FirstName,
            LastName,
            Email,
            Phone,
            Message,
            EncSeed,
            EncFile1,
            EncFile2,
            EncFile3,
            EncFile4,
            EncFile5,
            IPAddress,
            SentDate)
          values (
            '$firstname',
            '$lastname',
            '$email',
            '$phone',
            '$mail_message',
            '$seed',
            '$enc1',
            '$enc2',
            '$enc3',
            '$enc4',
            '$enc5',
            '$ip',
            NOW()
          );");

        if ($q !== false) {
            $mail_message = htmlentities($mail_message);
            $mail_message = nl2br($mail_message);

            $html = '<h2>Besked fra Mitsite</h2><hr>';
            $html .= "<p><b>Navn:</b> $firstname $lastname<br><b>Telefon:</b> $phone<br><b>E-mail:</b> $email</p>";
            $html .= '<hr>' . $mail_message;

            if (isset($_FILES) && count($_FILES) > 0) {
                $html .= '<hr><h3>Billeder</h3>';
            }

            if (isset($_FILES['file1']) && $_FILES['file1']['name'] != null) {
                move_uploaded_file($_FILES['file1']['tmp_name'], "admin/message_files/$enc1");
                $html .= "<img src='https://mitsite.dk/admin/message_files/$enc1'><br>";
            }
            if (isset($_FILES['file2']) && $_FILES['file2']['name'] != null) {
                move_uploaded_file($_FILES['file2']['tmp_name'], "admin/message_files/$enc2");
                $html .= "<img src='https://mitsite.dk/admin/message_files/$enc2'><br>";
            }
            if (isset($_FILES['file3']) && $_FILES['file3']['name'] != null) {
                move_uploaded_file($_FILES['file3']['tmp_name'], "admin/message_files/$enc3");
                $html .= "<img src='https://mitsite.dk/admin/message_files/$enc3'><br>";
            }
            if (isset($_FILES['file4']) && $_FILES['file4']['name'] != null) {
                move_uploaded_file($_FILES['file4']['tmp_name'], "admin/message_files/$enc4");
                $html .= "<img src='https://mitsite.dk/admin/message_files/$enc4'><br>";
            }
            if (isset($_FILES['file5']) && $_FILES['file5']['name'] != null) {
                move_uploaded_file($_FILES['file5']['tmp_name'], "admin/message_files/$enc5");
                $html .= "<img src='https://mitsite.dk/admin/message_files/$enc5'><br>";
            }

            echo '<h2>Kontakt</h2><hr><p>Vi har modtaget din besked, og vil besvare den hurtigst muligt.</p>';

            // Send html mail with text and uploaded images
            $headers = "MIME-Version: 1.0" . "\r\n";
            $headers .= "Content-type: text/html; charset=iso-8859-1" . "\r\n";
            $headers .= "From: contact@mitsite.dk" . "\r\n" .
                "Reply-To: contact@mitsiteom.dk" . "\r\n" .
                "X-Mailer: PHP/" . phpversion();

            mail('minmail@hotmail.com', 'Besked fra mitsite', $html, $headers);
        }

        require 'inc/Bottom.inc';
        die;
    }
}

// general form check
$err_msg = (isset($form_valid) && !$form_valid) ? '<p class="error">Alle felter skal udfyldes.</p><hr>' : '';

// individual check done only if general check yielded nothing
$err_list_html = '';
if (count($errors) > 0) {
    $err_list_html = "\n<ul>\n";

    foreach ($errors as $e) {
        $err_list_html .= "<li class=\"error\">$e</li>\n";
    }

    $err_list_html .= "</ul>\n\n";
    $err_msg = $err_list_html;
}

echo <<< HTML

    <h2>Kontakt</h2>
    <hr>
    $err_msg
    <form action="./kontakt" method="post" enctype="multipart/form-data">
        <div class="row">
            <div class="col-md-6">
                <label for="firstname">Fornavn</label><br>
                <input type="text" value="$firstname" name="firstname" id="firstname" class="checkout form-control" required>
            </div>
            <div class="col-md-6">
                <label for="lastname">Efternavn</label><br>
                <input type="text" value="$lastname" name="lastname" id="lastname" class="checkout form-control" required>
            </div>
        </div>

        <div class="row">
            <div class="col-md-6">
                <label for="email">E-mail</label><br>
                <input type="email" value="$email" name="email" id="email" class="checkout form-control" required>
            </div>
            <div class="col-md-6">
                <label for="phone">Telefon</label><br>
                <input type="tel" value="$phone" name="phone" id="phone" class="checkout form-control" required>
            </div>
        </div>

        <div class="row">
            <div class="col-md-12">
                <label for="message">Meddelelse</label><br>
                <textarea id="message" name="mail_message" class="checkout form-control" required style="height:200px;">$mail_message</textarea>
            </div>
        </div>

        <div class="row text-center"><button type="submit" class="btn btn-primary">Send</button></div>

        <div class="row h3">
            <div class="col-md-12">Billeder, der skal vedh&aelig;ftes beskeden (valgfrit)</div>
        </div>

        <div class="row">
            <div class="col-md-12">
                <input type="file" name="file1"><br>
                <input type="file" name="file2"><br>
                <input type="file" name="file3"><br>
                <input type="file" name="file4"><br>
                <input type="file" name="file5">
            </div>
        </div>
    </form>

HTML;


require 'inc/Bottom.inc';

<?php 
if(isset($_POST["captcha"])) 
if($_SESSION["captcha"]==$_POST["captcha"]) 
{ 
    //CAPTHCA is valid; proceed the message: save to database, send by e-mail … 
    echo '<div class="alert alert-success">CAPTHCA is valid; proceed the message</div>'; 
} 
else 
{ 
    echo '<div class="alert alert-danger">CAPTHCA is not valid; ignore submission</div>'; 
} 
?>

  <div class="form-group">
    <div class="col-sm-5 pull-left"><label for="pwd">Anti Spam code, Please Enter 3 Black Symbols</label>
    <img src="captcha.php" alt="captcha image"></div>
    <div class="col-sm-7 pull-right"><input type="text" name="captcha" size="3″ maxlength="3″ class="form-control"></div>
  </div>

<?php
session_start(); 
header("Expires: Mon, 26 Jul 1997 05:00:00 GMT"); 
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT"); 
header("Cache-Control: no-store, no-cache, must-revalidate"); 
header("Cache-Control: post-check=0, pre-check=0", false); 
header("Pragma: no-cache"); 
 
function _generateRandom($length=6) 
{ 
    $_rand_src = array( 
        array(48,57) //digits 
        , array(97,122) //lowercase chars 
//      , array(65,90) //uppercase chars 
    ); 
    srand ((double) microtime() * 1000000); 
    $random_string = ""; 
    for($i=0;$i<$length;$i++){ 
        $i1=rand(0,sizeof($_rand_src)-1); 
        $random_string .= chr(rand($_rand_src[$i1][0],$_rand_src[$i1][1])); 
    } 
    return $random_string; 
} 
 
$im = @imagecreatefromjpeg("captcha.jpg"); 
$rand = _generateRandom(3); 
$_SESSION['captcha'] = $rand; 
ImageString($im, 5, 2, 2, $rand[0]." ".$rand[1]." ".$rand[2]." ", ImageColorAllocate ($im, 0, 0, 0)); 
$rand = _generateRandom(3); 
ImageString($im, 5, 2, 2, " ".$rand[0]." ".$rand[1]." ".$rand[2], ImageColorAllocate ($im, 255, 0, 0)); 
Header ('Content-type: image/jpeg'); 
imagejpeg($im,NULL,100); 
ImageDestroy($im); 
?>