/password-protected.php

<?php

/*
Plugin Name: Password Protected
Plugin URI: http://www.benhuson.co.uk/
Description: A very simple way to quickly password protect your WordPress site with a single password. Integrates seamlessly into your WordPress privacy settings.
Version: 1.4
Author: Ben Huson
Author URI: http://www.benhuson.co.uk/
License: GPLv2
*/

/*
Copyright 2012 Ben Huson (email : ben@thewhiteroom.net)

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License, version 2, 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.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

/**
 * @todo Use wp_hash_password() ?
 */

define( 'PASSWORD_PROTECTED_SUBDIR', '/' . str_replace( basename( __FILE__ ), '', plugin_basename( __FILE__ ) ) );
define( 'PASSWORD_PROTECTED_URL', plugins_url( PASSWORD_PROTECTED_SUBDIR ) );
define( 'PASSWORD_PROTECTED_DIR', plugin_dir_path( __FILE__ ) );

global $Password_Protected;
$Password_Protected = new Password_Protected();

class Password_Protected {
	
	var $version = '1.4';
	var $admin   = null;
	var $errors  = null;
	
	/**
	 * Constructor
	 */
	function Password_Protected() {
		$this->errors = new WP_Error();
		register_activation_hook( __FILE__, array( &$this, 'install' ) );
		add_action( 'plugins_loaded', array( $this, 'load_plugin_textdomain' ) );
		add_action( 'init', array( $this, 'maybe_process_login' ), 1 );
		add_action( 'wp', array( $this, 'disable_feeds' ) );
		add_action( 'template_redirect', array( $this, 'maybe_show_login' ), 1 );
		add_filter( 'pre_option_password_protected_status', array( $this, 'allow_feeds' ) );
		add_filter( 'pre_option_password_protected_status', array( $this, 'allow_administrators' ) );
		if ( is_admin() ) {
			include_once( dirname( __FILE__ ) . '/admin/admin.php' );
			$this->admin = new Password_Protected_Admin();
		}
	}
	
	/**
	 * I18n
	 */
	function load_plugin_textdomain() {
		load_plugin_textdomain( 'password-protected', false, basename( dirname( __FILE__ ) ) . '/languages' );
	}
	
	/**
	 * Is Active?
	 */
	function is_active() {
		if ( (bool) get_option( 'password_protected_status' ) ) {
			if ( ! defined( 'DONOTCACHEPAGE' ) )
				define( 'DONOTCACHEPAGE', true );
			return true;
		}
		return false;
	}
	
	/**
	 * Disable Feeds
	 *
	 * @todo An option/filter to prevent disabling of feeds.
	 */
	function disable_feeds() {
		if ( $this->is_active() ) {
			add_action( 'do_feed', array( $this, 'disable_feed' ), 1 );
			add_action( 'do_feed_rdf', array( $this, 'disable_feed' ), 1 );
			add_action( 'do_feed_rss', array( $this, 'disable_feed' ), 1 );
			add_action( 'do_feed_rss2', array( $this, 'disable_feed' ), 1 );
			add_action( 'do_feed_atom', array( $this, 'disable_feed' ), 1 );
		}
	}
	
	/**
	 * Disable Feed
	 * @todo Make Translatable
	 */
	function disable_feed() {
		wp_die( sprintf( __( 'Feeds are not available for this site. Please visit the <a href="%s">website</a>.', 'password-protected' ), get_bloginfo( 'url' ) ) );
	}
	
	/**
	 * Allow Feeds
	 */
	function allow_feeds( $bool ) {
		if ( is_feed() && (bool) get_option( 'password_protected_feeds' ) )
			return 0;
		return $bool;
	}
	
	/**
	 * Allow Administrators
	 */
	function allow_administrators( $bool ) {
		if ( ! is_admin() && current_user_can( 'manage_options' ) && (bool) get_option( 'password_protected_administrators' ) )
			return 0;
		return $bool;
	}
	
	/**
	 * Maybe Process Login
	 */
	function maybe_process_login() {
		if ( $this->is_active() && isset( $_REQUEST['password_protected_pwd'] ) ) {
			$password_protected_pwd = $_REQUEST['password_protected_pwd'];
			$pwd = get_option( 'password_protected_password' );
			// If correct password...
			if ( ( md5( $password_protected_pwd ) == $pwd && $pwd != '' ) || apply_filters( 'password_protected_process_login', false, $password_protected_pwd ) ) {
				$this->set_auth_cookie();
				if ( ! empty( $_REQUEST['redirect_to'] ) ) {
					wp_redirect( $_REQUEST['redirect_to'] );
					exit;
				}
			} else {
				// ... otherwise incorrect password
				$this->clear_auth_cookie();
				$this->errors->add( 'incorrect_password', __( 'Incorrect Password', 'password-protected' ) );
			}
		}
		
		// Log out
		if ( isset( $_REQUEST['password-protected'] ) && $_REQUEST['password-protected'] == 'logout' ) {
			$this->logout();
			$redirect_to = remove_query_arg( array( 'password-protected', 'redirect_to' ), ( is_ssl() ? 'https://' : 'http://' ) . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'] );
			$query = array(
				'password-protected' => 'login',
				'redirect_to' => urlencode( $redirect_to )
			);
			wp_redirect( add_query_arg( $query, home_url() ) );
			exit();
		}
	}
	
	/**
	 * Maybe Show Login
	 */
	function maybe_show_login() {
		// Don't show login if not enabled
		if ( ! $this->is_active() )
			return;
		
		// Logged in
		if ( $this->validate_auth_cookie() )
			return;
		
		// Show login form
		if ( isset( $_REQUEST['password-protected'] ) && 'login' == $_REQUEST['password-protected'] ) {
			include( dirname( __FILE__ ) . '/theme/login.php' );
			exit();
		} else {
			$query = array(
				'password-protected' => 'login',
				'redirect_to' => urlencode( ( is_ssl() ? 'https://' : 'http://' ) . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'] )
			);
			wp_redirect( add_query_arg( $query, home_url() ) );
			exit();
		}
	}
	
	/**
	 * Get Site ID
	 */
	function get_site_id() {
		global $blog_id;
		return 'bid_' . apply_filters( 'password_protected_blog_id', $blog_id );
	}
	
	/**
	 * Logout
	 */
	function logout() {
		$this->clear_auth_cookie();
		do_action( 'password_protected_logout' );
	}
	
	/**
	 * Validate Auth Cookie
	 */
	function validate_auth_cookie( $cookie = '', $scheme = '' ) {
		if ( ! $cookie_elements = $this->parse_auth_cookie( $cookie, $scheme ) ) {
			do_action( 'password_protected_auth_cookie_malformed', $cookie, $scheme );
			return false;
		}
		extract( $cookie_elements, EXTR_OVERWRITE );
		
		$expired = $expiration;
	
		// Allow a grace period for POST and AJAX requests
		if ( defined( 'DOING_AJAX' ) || 'POST' == $_SERVER['REQUEST_METHOD'] )
			$expired += 3600;
	
		// Quick check to see if an honest cookie has expired
		if ( $expired < time() ) {
			do_action('password_protected_auth_cookie_expired', $cookie_elements);
			return false;
		}
		
		$pass = md5( get_option( 'password_protected_password' ) );
		$pass_frag = substr( $pass, 8, 4 );
	
		$key = md5( $this->get_site_id() . $pass_frag . '|' . $expiration );
		$hash = hash_hmac( 'md5', $this->get_site_id() . '|' . $expiration, $key);
		
		if ( $hmac != $hash ) {
			do_action( 'password_protected_auth_cookie_bad_hash', $cookie_elements );
			return false;
		}
	
		if ( $expiration < time() ) // AJAX/POST grace period set above
			$GLOBALS['login_grace_period'] = 1;
	
		return true;
	}

	/**
	 * Generate Auth Cookie
	 */
	function generate_auth_cookie( $expiration, $scheme = 'auth' ) {
		$pass = md5( get_option( 'password_protected_password' ) );
		$pass_frag = substr( $pass, 8, 4 );
		
		$key = md5( $this->get_site_id() . $pass_frag . '|' . $expiration );
		$hash = hash_hmac( 'md5', $this->get_site_id() . '|' . $expiration, $key );
		$cookie = $this->get_site_id() . '|' . $expiration . '|' . $hash;
	
		return $cookie;
	}
	
	/**
	 * Parse Auth Cookie
	 */
	function parse_auth_cookie( $cookie = '', $scheme = '' ) {
		if ( empty( $cookie ) ) {
			$cookie_name = $this->cookie_name();
	
			if ( empty( $_COOKIE[$cookie_name] ) )
				return false;
			$cookie = $_COOKIE[$cookie_name];
		}
	
		$cookie_elements = explode( '|', $cookie );
		if ( count( $cookie_elements ) != 3 )
			return false;
	
		list( $site_id, $expiration, $hmac ) = $cookie_elements;
	
		return compact( 'site_id', 'expiration', 'hmac', 'scheme' );
	}
	
	/**
	 * Set Auth Cookie
	 * @todo
	 */
	function set_auth_cookie( $remember = false, $secure = '') {
		if ( $remember ) {
			$expiration = $expire = time() + apply_filters( 'password_protected_auth_cookie_expiration', 1209600, $remember );
		} else {
			$expiration = time() + apply_filters( 'password_protected_auth_cookie_expiration', 172800, $remember );
			$expire = 0;
		}
	
		if ( '' === $secure )
			$secure = is_ssl();
	
		$secure_password_protected_cookie = apply_filters( 'password_protected_secure_password_protected_cookie', false, $secure );
		$password_protected_cookie = $this->generate_auth_cookie( $expiration, 'password_protected' );
		
		setcookie( $this->cookie_name(), $password_protected_cookie, $expire, COOKIEPATH, COOKIE_DOMAIN, $secure_password_protected_cookie, true );
		if ( COOKIEPATH != SITECOOKIEPATH )
			setcookie( $this->cookie_name(), $password_protected_cookie, $expire, SITECOOKIEPATH, COOKIE_DOMAIN, $secure_password_protected_cookie, true );
	}
	
	/**
	 * Clear Auth Cookie
	 */
	function clear_auth_cookie() {
		setcookie( $this->cookie_name(), ' ', time() - 31536000, COOKIEPATH, COOKIE_DOMAIN );
		setcookie( $this->cookie_name(), ' ', time() - 31536000, SITECOOKIEPATH, COOKIE_DOMAIN );
	}
	
	/**
	 * Cookie Name
	 */
	function cookie_name() {
		return $this->get_site_id() . '_password_protected_auth';
	}
	
	/**
	 * Install
	 */
	function install() {
		$old_version = get_option( 'password_protected_version' );
		
		// 1.1 - Upgrade to MD5
		if ( empty( $old_version ) || version_compare( '1.1', $old_version ) ) {
			$pwd = get_option( 'password_protected_password' );
			if ( ! empty( $pwd ) ) {
				$new_pwd = md5( $pwd );
				update_option( 'password_protected_password', $new_pwd );
			} 
		}
		
		update_option( 'password_protected_version', $this->version );
	}

}

?>