Login using the password from protected pages

Question

Does anyone know the logic on how to do the following:

I have a login section with a password field only on the index, so the user enter the password and submit. Upon submission, I was hoping if the password entered can match with the passwords of the existing protected pages. Once there's a single match, the user will be redirected to that password protected page as login successful.

Do u think it's possible..? I need some hope here, thanks!

Answer 1

This answer assumes you are talking about the regular login page, /wp-login.php, and that each user exists as a user in the WordPress database. After reading your question again I'm not so sure that is what you want to do.

This is a first attempt, but it is not complete because it asks for your password again on the protected post, and because it does not know when you want to visit /wp-admin/ or another restricted area.

add_filter( 'login_redirect', 'wpse6072_login_redirect', 10, 2 );
function wpse6072_login_redirect( $redirect_to, $requested_redirect )
{
    // You somehow need to figure out how to make a difference between an admin login and a regular login
    if ( /*! array_key_exists( 'redirect_to', $_REQUEST ) &&*/ array_key_exists( 'pwd', $_POST ) ) {
        global $wpdb;
        $post_id = $wpdb->get_var( $wpdb->prepare( "SELECT ID FROM {$wpdb->posts} WHERE post_password = %s", $_POST['pwd'] ) );
        $post_permalink = get_permalink( $post_id );
        if ( $post_permalink ) {
            // TODO: Set the post password in a way that satisfied WordPress
            $redirect_to = $post_permalink;
        }
    }
    return $redirect_to;
}