plugin/authwordpress/auth.php

<?php
/**
 * DokuWiki Plugin authwordpress (Auth Component)
 *
 * Provides authentication against a WordPress MySQL database backend
 *
 * 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; version 2 of the License
 *
 * 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.
 *
 * See the COPYING file in your DokuWiki folder for details
 *
 * @author     Damien Regad <dregad@mantisbt.org>
 * @copyright  2015 Damien Regad
 * @license    GPL 2 http://www.gnu.org/licenses/gpl-2.0.html
 * @version    1.1
 * @link       https://github.com/dregad/dokuwiki-authwordpress
 */


// must be run within Dokuwiki
if(!defined('DOKU_INC')) die();

/**
 * WordPress password hashing framework
 */
require_once('class-phpass.php');

/**
 * Authentication class
 */
class auth_plugin_authwordpress extends DokuWiki_Auth_Plugin {

	/**
	 * SQL statement to retrieve User data from WordPress DB
	 * (including group memberships)
	 * '%prefix%' will be replaced by the actual prefix (from plugin config)
	 */
	protected $sql_wp_user_data = "SELECT
			id, user_login, user_pass, user_email, display_name,
			meta_value AS groups
		FROM %prefix%users u
		JOIN %prefix%usermeta m ON u.id = m.user_id AND meta_key = '%prefix%capabilities'";

	/**
	 * Wordpress database connection
	 */
	protected $db;

	/**
	 * Users cache
	 */
	protected $users;

	/**
	 * True if all users have been loaded in the cache
	 * @see $users
	 */
	protected $usersCached = false;

	/**
	 * Filter pattern
	 */
	protected $filter;

	/**
	 * Constructor.
	 */
	public function __construct() {
		parent::__construct();

		// Plugin capabilities
		$this->cando['getUsers'] = true;
		$this->cando['getUserCount'] = true;

		// Try to establish a connection to the WordPress DB
		// abort in case of failure
		try {
			$this->wp_connect();
		}
		catch (Exception $e) {
			msg(sprintf($this->getLang('error_connect_failed'), $e->getMessage()));
			$this->success = false;
			return;
		}

		// Initialize SQL query with configured prefix
		$this->sql_wp_user_data = str_replace(
			'%prefix%',
			$this->getConf('prefix'),
			$this->sql_wp_user_data
		);

		$this->success = true;
	}


	/**
	 * Check user+password
	 *
	 * @param   string $user the user name
	 * @param   string $pass the clear text password
	 * @return  bool
	 *
	 * @uses PasswordHash::CheckPassword WordPress password hasher
	 */
	public function checkPass($user, $pass) {
		$data = $this->getUserData($user);
		if ($data === false) {
			return false;
		}

		$hasher = new PasswordHash(8, true);
		$check = $hasher->CheckPassword($pass, $data['pass']);
		dbglog("Password " . ($check ? 'OK' : 'Invalid'));

		return $check;
	}

	/**
	 * Bulk retrieval of user data
	 *
	 * @param   int   $start index of first user to be returned
	 * @param   int   $limit max number of users to be returned
	 * @param   array $filter array of field/pattern pairs
	 * @return  array userinfo (refer getUserData for internal userinfo details)
	 */
	public function retrieveUsers($start = 0, $limit = 0, $filter = array()) {
		msg($this->getLang('user_list_use_wordpress'));

		$this->cacheAllUsers();

		// Apply filter and pagination
		$this->setFilter($filter);
		$list = array();
        foreach($this->users as $user => $info) {
            if($this->applyFilter($user, $info)) {
                if($i >= $start) {
                    $list[$user] = $info;
                    $count++;
                    if($limit > 0 && $count >= $limit) {
                    	break;
                    }
                }
                $i++;
            }
        }

		return $list;
	}

	/**
	 * Return a count of the number of user which meet $filter criteria
	 *
	 * @param array $filter
	 * @return int
	 */
	public function getUserCount($filter = array()) {
		$this->cacheAllUsers();

		if(empty($filter)) {
			$count = count($this->users);
		} else {
			$this->setFilter($filter);
	        foreach($this->users as $user => $info) {
	            $count += (int)$this->applyFilter($user, $info);
	        }
		}
		return $count;
	}


	/**
	 * Returns info about the given user
	 *
	 * @param   string $user the user name
	 * @return  array containing user data or false
	 */
	public function getUserData($user, $requireGroups=true) {
		if(isset($this->users[$user])) {
			return $this->users[$user];
		}

		$sql = $this->sql_wp_user_data
			. 'WHERE user_login = :user';

		$stmt = $this->db->prepare($sql);
		$stmt->bindParam(':user', $user);
		dbglog("Retrieving data for user '$user'\n$sql");

		if (!$stmt->execute()) {
			// Query execution failed
			$err = $stmt->errorInfo();
			dbglog("Error $err[1]: $err[2]");
			return false;
		}

		$user = $stmt->fetch(PDO::FETCH_ASSOC);
		if ($user === false) {
			// Unknown user
			dbglog("Unknown user");
			return false;
		}

		return $this->cacheUser($user);
	}


	/**
	 * Connect to Wordpress database
	 * Initializes $db property as PDO object
	 */
	protected function wp_connect() {
		if($this->db) {
			// Already connected
			return;
		}

		// Build connection string
		$dsn = array(
			'host=' . $this->getConf('hostname'),
			'dbname=' . $this->getConf('database'),
		);
		$port = $this->getConf('port');
		if ($port) {
			$dsn[] = 'port=' . $port;
		}
		$dsn = 'mysql:' . implode(';', $dsn);

		$this->db = new PDO($dsn, $this->getConf('username'), $this->getConf('password'));
	}

	/**
	 * Convert a Wordpress DB User row to DokuWiki user info array
	 * and stores it in the users cache
	 *
	 * @param  array $user Raw Wordpress user table row
	 * @return array user data
	 */
	protected function cacheUser($row) {
		global $conf;

		$login = $row['user_login'];

		// If the user is already cached, just return it
		if(isset($this->users[$login])) {
			return $this->users[$login];
		}

		// Group membership - add DokuWiki's default group
		$groups = array_keys(unserialize($row['groups']));
		if($this->getConf('usedefaultgroup')) {
			$groups[] = $conf['defaultgroup'];
		}

		$info = array(
			'user' => $login,
			'name' => $row['display_name'],
			'pass' => $row['user_pass'],
			'mail' => $row['user_email'],
			'grps' => $groups,
		);

		$this->users[$login] = $info;
		return $info;
	}

	/**
	 * Loads all Wordpress users into the cache
	 *
	 * @return void
	 */
	protected function cacheAllUsers() {
		if($this->usersCached) {
			return;
		}

		$stmt = $this->db->prepare($this->sql_wp_user_data);
		$stmt->execute();

		foreach($stmt->fetchAll(PDO::FETCH_ASSOC) as $user) {
			$this->cacheUser($user);
		}

		$this->usersCached = true;
	}

    /**
     * Build filter patterns from given criteria
     *
     * @param array $filter
     */
    protected function setFilter($filter) {
        $this->filter = array();
        foreach($filter as $field => $value) {
        	// Build PCRE pattern, utf8 + case insensitive
            $this->filter[$field] = '/' . str_replace('/', '\/', $value) . '/ui';
        }
    }

    /**
     * Return true if given user matches filter pattern, false otherwise
     *
     * @param string $user login
     * @param array  $info User data
     * @return bool
     */
    protected function applyFilter($user, $info) {
        foreach ($this->filter as $elem => $pattern) {
        	if ($elem == 'grps') {
                if (empty(preg_grep($pattern, $info['grps']))) {
                	return false;
                }
        	} else {
                if(!preg_match($pattern, $info[$elem])) {
                	return false;
                }
        	}
        }
        return true;
    }

}

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