<?php
/**
 * @package     Joomla.Plugin
 * @subpackage  Authentication.cookie
 *
 * @copyright   Copyright (C) 2005 - 2016 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE.txt
 */

defined('_JEXEC') or die;

/**
 * Joomla Authentication plugin
 *
 * @since  3.2
 * @note   Code based on http://jaspan.com/improved_persistent_login_cookie_best_practice
 *         and http://fishbowl.pastiche.org/2004/01/19/persistent_login_cookie_best_practice/
 */
class PlgAuthenticationCookie extends JPlugin
{
	/**
	 * Application object
	 *
	 * @var    JApplicationCms
	 * @since  3.2
	 */
	protected $app;

	/**
	 * Database object
	 *
	 * @var    JDatabaseDriver
	 * @since  3.2
	 */
	protected $db;

	/**
	 * This method should handle any authentication and report back to the subject
	 *
	 * @param   array   $credentials  Array holding the user credentials
	 * @param   array   $options      Array of extra options
	 * @param   object  &$response    Authentication response object
	 *
	 * @return  boolean
	 *
	 * @since   3.2
	 */
	public function onUserAuthenticate($credentials, $options, &$response)
	{
		// No remember me for admin
		if ($this->app->isAdmin())
		{
			return false;
		}

		// Get cookie
		$cookieName  = 'joomla_remember_me_' . JUserHelper::getShortHashedUserAgent();
		$cookieValue = $this->app->input->cookie->get($cookieName);

		// Try with old cookieName (pre 3.6.0) if not found
		if (!$cookieValue)
		{
			$cookieName  = JUserHelper::getShortHashedUserAgent();
			$cookieValue = $this->app->input->cookie->get($cookieName);
		}

		if (!$cookieValue)
		{
			return false;
		}

		$cookieArray = explode('.', $cookieValue);

		// Check for valid cookie value
		if (count($cookieArray) != 2)
		{
			// Destroy the cookie in the browser.
			$this->app->input->cookie->set($cookieName, false, time() - 42000, $this->app->get('cookie_path', '/'), $this->app->get('cookie_domain'));
			JLog::add('Invalid cookie detected.', JLog::WARNING, 'error');

			return false;
		}

		$response->type = 'Cookie';

		// Filter series since we're going to use it in the query
		$filter = new JFilterInput;
		$series = $filter->clean($cookieArray[1], 'ALNUM');

		// Remove expired tokens
		$query = $this->db->getQuery(true)
			->delete('#__user_keys')
			->where($this->db->quoteName('time') . ' < ' . $this->db->quote(time()));

		try
		{
			$this->db->setQuery($query)->execute();
		}
		catch (RuntimeException $e)
		{
			// We aren't concerned with errors from this query, carry on
		}

		// Find the matching record if it exists.
		$query = $this->db->getQuery(true)
			->select($this->db->quoteName(array('user_id', 'token', 'series', 'time')))
			->from($this->db->quoteName('#__user_keys'))
			->where($this->db->quoteName('series') . ' = ' . $this->db->quote($series))
			->where($this->db->quoteName('uastring') . ' = ' . $this->db->quote($cookieName))
			->order($this->db->quoteName('time') . ' DESC');

		try
		{
			$results = $this->db->setQuery($query)->loadObjectList();
		}
		catch (RuntimeException $e)
		{
			$response->status = JAuthentication::STATUS_FAILURE;

			return false;
		}

		if (count($results) !== 1)
		{
			// Destroy the cookie in the browser.
			$this->app->input->cookie->set($cookieName, false, time() - 42000, $this->app->get('cookie_path', '/'), $this->app->get('cookie_domain'));
			$response->status = JAuthentication::STATUS_FAILURE;

			return false;
		}

		// We have a user with one cookie with a valid series and a corresponding record in the database.
		if (!JUserHelper::verifyPassword($cookieArray[0], $results[0]->token))
		{
			/*
			 * This is a real attack! Either the series was guessed correctly or a cookie was stolen and used twice (once by attacker and once by victim).
			 * Delete all tokens for this user!
			 */
			$query = $this->db->getQuery(true)
				->delete('#__user_keys')
				->where($this->db->quoteName('user_id') . ' = ' . $this->db->quote($results[0]->user_id));

			try
			{
				$this->db->setQuery($query)->execute();
			}
			catch (RuntimeException $e)
			{
				// Log an alert for the site admin
				JLog::add(
					sprintf('Failed to delete cookie token for user %s with the following error: %s', $results[0]->user_id, $e->getMessage()),
					JLog::WARNING,
					'security'
				);
			}

			// Destroy the cookie in the browser.
			$this->app->input->cookie->set($cookieName, false, time() - 42000, $this->app->get('cookie_path', '/'), $this->app->get('cookie_domain'));

			// Issue warning by email to user and/or admin?
			JLog::add(JText::sprintf('PLG_AUTH_COOKIE_ERROR_LOG_LOGIN_FAILED', $results[0]->user_id), JLog::WARNING, 'security');
			$response->status = JAuthentication::STATUS_FAILURE;

			return false;
		}

		// Make sure there really is a user with this name and get the data for the session.
		$query = $this->db->getQuery(true)
			->select($this->db->quoteName(array('id', 'username', 'password')))
			->from($this->db->quoteName('#__users'))
			->where($this->db->quoteName('username') . ' = ' . $this->db->quote($results[0]->user_id))
			->where($this->db->quoteName('requireReset') . ' = 0');

		try
		{
			$result = $this->db->setQuery($query)->loadObject();
		}
		catch (RuntimeException $e)
		{
			$response->status = JAuthentication::STATUS_FAILURE;

			return false;
		}

		if ($result)
		{
			// Bring this in line with the rest of the system
			$user = JUser::getInstance($result->id);

			// Set response data.
			$response->username = $result->username;
			$response->email    = $user->email;
			$response->fullname = $user->name;
			$response->password = $result->password;
			$response->language = $user->getParam('language');

			// Set response status.
			$response->status        = JAuthentication::STATUS_SUCCESS;
			$response->error_message = '';
		}
		else
		{
			$response->status        = JAuthentication::STATUS_FAILURE;
			$response->error_message = JText::_('JGLOBAL_AUTH_NO_USER');
		}
	}

	/**
	 * We set the authentication cookie only after login is successfullly finished.
	 * We set a new cookie either for a user with no cookies or one
	 * where the user used a cookie to authenticate.
	 *
	 * @param   array  $options  Array holding options
	 *
	 * @return  boolean  True on success
	 *
	 * @since   3.2
	 */
	public function onUserAfterLogin($options)
	{
		// No remember me for admin
		if ($this->app->isAdmin())
		{
			return false;
		}

		if (isset($options['responseType']) && $options['responseType'] == 'Cookie')
		{
			// Logged in using a cookie
			$cookieName = 'joomla_remember_me_' . JUserHelper::getShortHashedUserAgent();

			// We need the old data to get the existing series
			$cookieValue = $this->app->input->cookie->get($cookieName);

			// Try with old cookieName (pre 3.6.0) if not found
			if (!$cookieValue)
			{
				$oldCookieName = JUserHelper::getShortHashedUserAgent();
				$cookieValue   = $this->app->input->cookie->get($oldCookieName);

				// Destroy the old cookie in the browser
				$this->app->input->cookie->set($oldCookieName, false, time() - 42000, $this->app->get('cookie_path', '/'), $this->app->get('cookie_domain'));
			}

			$cookieArray = explode('.', $cookieValue);

			// Filter series since we're going to use it in the query
			$filter = new JFilterInput;
			$series = $filter->clean($cookieArray[1], 'ALNUM');
		}
		elseif (!empty($options['remember']))
		{
			// Remember checkbox is set
			$cookieName = 'joomla_remember_me_' . JUserHelper::getShortHashedUserAgent();

			// Create a unique series which will be used over the lifespan of the cookie
			$unique     = false;
			$errorCount = 0;

			do
			{
				$series = JUserHelper::genRandomPassword(20);
				$query  = $this->db->getQuery(true)
					->select($this->db->quoteName('series'))
					->from($this->db->quoteName('#__user_keys'))
					->where($this->db->quoteName('series') . ' = ' . $this->db->quote($series));

				try
				{
					$results = $this->db->setQuery($query)->loadResult();

					if (is_null($results))
					{
						$unique = true;
					}
				}
				catch (RuntimeException $e)
				{
					$errorCount++;

					// We'll let this query fail up to 5 times before giving up, there's probably a bigger issue at this point
					if ($errorCount == 5)
					{
						return false;
					}
				}
			}

			while ($unique === false);
		}
		else
		{
			return false;
		}

		// Get the parameter values
		$lifetime = $this->params->get('cookie_lifetime', '60') * 24 * 60 * 60;
		$length   = $this->params->get('key_length', '16');

		// Generate new cookie
		$token       = JUserHelper::genRandomPassword($length);
		$cookieValue = $token . '.' . $series;

		// Overwrite existing cookie with new value
		$this->app->input->cookie->set(
			$cookieName, $cookieValue,
			time() + $lifetime,
			$this->app->get('cookie_path', '/'),
			$this->app->get('cookie_domain'),
			$this->app->isSSLConnection()
		);
		$query = $this->db->getQuery(true);

		if (!empty($options['remember']))
		{
			// Create new record
			$query
				->insert($this->db->quoteName('#__user_keys'))
				->set($this->db->quoteName('user_id') . ' = ' . $this->db->quote($options['user']->username))
				->set($this->db->quoteName('series') . ' = ' . $this->db->quote($series))
				->set($this->db->quoteName('uastring') . ' = ' . $this->db->quote($cookieName))
				->set($this->db->quoteName('time') . ' = ' . (time() + $lifetime));
		}
		else
		{
			// Update existing record with new token
			$query
				->update($this->db->quoteName('#__user_keys'))
				->where($this->db->quoteName('user_id') . ' = ' . $this->db->quote($options['user']->username))
				->where($this->db->quoteName('series') . ' = ' . $this->db->quote($series))
				->where($this->db->quoteName('uastring') . ' = ' . $this->db->quote($cookieName));
		}

		$hashed_token = JUserHelper::hashPassword($token);

		$query->set($this->db->quoteName('token') . ' = ' . $this->db->quote($hashed_token));

		try
		{
			$this->db->setQuery($query)->execute();
		}
		catch (RuntimeException $e)
		{
			return false;
		}

		return true;
	}

	/**
	 * This is where we delete any authentication cookie when a user logs out
	 *
	 * @param   array  $options  Array holding options (length, timeToExpiration)
	 *
	 * @return  boolean  True on success
	 *
	 * @since   3.2
	 */
	public function onUserAfterLogout($options)
	{
		// No remember me for admin
		if ($this->app->isAdmin())
		{
			return false;
		}

		$cookieName  = 'joomla_remember_me_' . JUserHelper::getShortHashedUserAgent();
		$cookieValue = $this->app->input->cookie->get($cookieName);

		// There are no cookies to delete.
		if (!$cookieValue)
		{
			return true;
		}

		$cookieArray = explode('.', $cookieValue);

		// Filter series since we're going to use it in the query
		$filter = new JFilterInput;
		$series = $filter->clean($cookieArray[1], 'ALNUM');

		// Remove the record from the database
		$query = $this->db->getQuery(true)
			->delete('#__user_keys')
			->where($this->db->quoteName('series') . ' = ' . $this->db->quote($series));

		try
		{
			$this->db->setQuery($query)->execute();
		}
		catch (RuntimeException $e)
		{
			// We aren't concerned with errors from this query, carry on
		}

		// Destroy the cookie
		$this->app->input->cookie->set(
			$cookieName,
			false,
			time() - 42000,
			$this->app->get('cookie_path', '/'),
			$this->app->get('cookie_domain')
		);

		return true;
	}
}
