add logout to password protect page

Question

I have a page I want to password-protect. I've tried the code below, but I am unable to put logout to the page. Any other quick (and easy) way to do this? Thanks!

How I can add logout to this password protected page as described below

$username = "the_username_here";
$password = "the_password_here";
$nonsense = "supercalifragilisticexpialidocious";

if (isset($_COOKIE['PrivatePageLogin'])) {
if ($_COOKIE['PrivatePageLogin'] == md5($password.$nonsense)) {


LOGGED IN CONTENT HERE

  exit;
} else {
  echo "Bad Cookie.";
  exit;
}
}

if (isset($_GET['p']) && $_GET['p'] == "login") {
if ($_POST['user'] != $username) {
  echo "Sorry, that username does not match.";
  exit;
 } else if ($_POST['keypass'] != $password) {
  echo "Sorry, that password does not match.";
  exit;
 } else if ($_POST['user'] == $username && $_POST['keypass'] == $password) {
  setcookie('PrivatePageLogin', md5($_POST['keypass'].$nonsense));
  header("Location: $_SERVER[PHP_SELF]");
 } else {
  echo "Sorry, you could not be logged in at this time.";
}
}

And the login form on the page...

<form action="<?php echo $_SERVER['PHP_SELF']; ?>?p=login" method="post">
<label><input type="text" name="user" id="user" /> Name</label><br />
<label><input type="password" name="keypass" id="keypass" /> Password</label><br />
<input type="submit" id="submit" value="Login" />
</form>

Any clue on how to get this solved ?

Answer 1

On any page

<?php if(isset($_COOKIE['PrivatePageLogin'])):?>
   <a href="logout.php">Logout</a>
<?php endif?>

logout.php

if(isset($_COOKIE['PrivatePageLogin'])){
    // delete cookie
    setcookie('PrivatePageLogin', null, time() - 1);
    // if you use sessions delete session variables as well
}
header('Location: index.php');

Answer 2

Simply provide a link to a page which clears the cookie you've set.

As a side note, saving the password in md5 alone in the client side is not secure whatsoever.

Answer 3

This doesn't answer the question of user1561466. With this answer I show you how one could use the password protected feature of WP with a logout button (without plugins):

logout.php:

<?php

if (isset($_SERVER['HTTP_COOKIE'])) {
    $cookies = explode(';', $_SERVER['HTTP_COOKIE']);
    foreach($cookies as $cookie) {
        $parts = explode('=', $cookie);
        $name = trim($parts[0]);
        setcookie($name, '', time()-1000);
        setcookie($name, '', time()-1000, '/');
    }
}
header('Location: index.php');

?>

Perhaps you could only delete only one cookie, but this is how I can independently of WP delete the cookie.

In page.php I have this:

<?php if (have_posts()) : while (have_posts()) : the_post(); ?>

    <?php
        if (!empty($post->post_password)) { // if there's a password

            if (isset($_COOKIE['wp-postpass_' . COOKIEHASH]) && wp_check_password( $post->post_password, $_COOKIE['wp-postpass_' . COOKIEHASH])) {
                echo '<a href="/logout.php">Logout</a><br /><br />';
            }
        }
    ?>

Sources: how to delete all cookies of my website in php , http://wordpress.org/support/topic/check-in-the-loop-if-a-post-is-password-protected