Waca\IdentificationVerifier

Complexity

Total Complexity

8

Size/Duplication

Total Lines	165
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	4

Test Coverage

Coverage

33.33%

Importance

Changes	4
Bugs	0	Features	1

6 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	6	1
A	isUserIdentified()	0	16	3
A	checkIdentificationCache()	0	21	1
A	clearExpiredCacheEntries()	0	10	1
A	cacheIdentificationStatus()	0	15	1
A	isIdentifiedOnWiki()	0	16	1

<?php
/******************************************************************************
 * Wikipedia Account Creation Assistance tool                                 *
 *                                                                            *
 * All code in this file is released into the public domain by the ACC        *
 * Development Team. Please see team.json for a list of contributors.         *
 ******************************************************************************/

namespace Waca;

use PDO;

use Waca\Helpers\HttpHelper;

/**
 * Class IdentificationVerifier
 *
 * Handles automatically verifying if users are identified with the Wikimedia Foundation or not.  Intended to be used
 * as necessary by the User class when a user's "forceidentified" attribute is NULL.
 *
 * @package  Waca
 * @author   Andrew "FastLizard4" Adams
 * @category Security-Critical
 */
class IdentificationVerifier
{
	/**
	 * This field is an array of parameters, in key => value format, that should be appended to the Meta Wikimedia
	 * Web Service Endpoint URL to query if a user is listed on the Identification Noticeboard.  Note that URL encoding
	 * of these values is *not* necessary; this is done automatically.
	 *
	 * @var string[]
	 * @category Security-Critical
	 */
	private static $apiQueryParameters = array(
		'action'   => 'query',
		'format'   => 'json',
		'prop'     => 'links',
		'titles'   => 'Access to nonpublic information policy/Noticeboard',
		// Username of the user to be checked, with User: prefix, goes here!  Set in isIdentifiedOnWiki()
		'pltitles' => '',
	);
	/** @var HttpHelper */
	private $httpHelper;
	/** @var SiteConfiguration */
	private $siteConfiguration;
	/** @var PdoDatabase */
	private $dbObject;

	/**
	 * IdentificationVerifier constructor.
	 *
	 * @param HttpHelper        $httpHelper
	 * @param SiteConfiguration $siteConfiguration
	 * @param PdoDatabase       $dbObject
	 */
	public function __construct(HttpHelper $httpHelper, SiteConfiguration $siteConfiguration, PdoDatabase $dbObject)
	{
		$this->httpHelper = $httpHelper;
		$this->siteConfiguration = $siteConfiguration;
		$this->dbObject = $dbObject;
	}

	/**
	 * Checks if the given user is identified to the Wikimedia Foundation.
	 *
	 * @param string $onWikiName The Wikipedia username of the user
	 *
	 * @return bool
	 * @category Security-Critical
	 */
	public function isUserIdentified($onWikiName)
	{
		if ($this->checkIdentificationCache($onWikiName)) {
			return true;
		}
		else {
			if ($this->isIdentifiedOnWiki($onWikiName)) {
				$this->cacheIdentificationStatus($onWikiName);

				return true;
			}
			else {
				return false;
			}
		}
	}

	/**
	 * Checks if the given user has a valid entry in the idcache table.
	 *
	 * @param string $onWikiName The Wikipedia username of the user
	 *
	 * @return bool
	 * @category Security-Critical
	 */
	private function checkIdentificationCache($onWikiName)
	{
		$interval = $this->siteConfiguration->getIdentificationCacheExpiry();

		$query = <<<SQL
			SELECT COUNT(`id`)
			FROM `idcache`
			WHERE `onwikiusername` = :onwikiname
				AND DATE_ADD(`checktime`, INTERVAL {$interval}) >= NOW();
SQL;
		$stmt = $this->dbObject->prepare($query);
		$stmt->bindValue(':onwikiname', $onWikiName, PDO::PARAM_STR);
		$stmt->execute();

		// Guaranteed by the query to only return a single row with a single column
		$results = $stmt->fetch(PDO::FETCH_NUM);

		// I don't expect this to ever be a value other than 0 or 1 since the `onwikiusername` column is declared as a
		// unique key - but meh.
		return $results[0] != 0;
	}

	/**
	 * Does pretty much exactly what it says on the label - this method will clear all expired idcache entries from the
	 * idcache table.  Meant to be called periodically by a maintenance script.
	 *
	 * @param SiteConfiguration $siteConfiguration
	 * @param PdoDatabase       $dbObject
	 *
	 * @return void
	 */
	public static function clearExpiredCacheEntries(SiteConfiguration $siteConfiguration, PdoDatabase $dbObject)
	{
		$interval = $siteConfiguration->getIdentificationCacheExpiry();

		$query = <<<SQL
			DELETE FROM `idcache`
			WHERE DATE_ADD(`checktime`, INTERVAL {$interval}) < NOW();
SQL;
		$dbObject->prepare($query)->execute();
	}

	/**
	 * This method will add an entry to the idcache that the given Wikipedia user has been verified as identified.  This
	 * is so we don't have to hit the API every single time we check.  The cache entry is valid for as long as specified
	 * in the ACC configuration (validity enforced by checkIdentificationCache() and clearExpiredCacheEntries()).
	 *
	 * @param string $onWikiName The Wikipedia username of the user
	 *
	 * @return void
	 * @category Security-Critical
	 */
	private function cacheIdentificationStatus($onWikiName)
	{
		$query = <<<SQL
			INSERT INTO `idcache`
				(`onwikiusername`)
			VALUES
				(:onwikiname)
			ON DUPLICATE KEY UPDATE
				`onwikiusername` = VALUES(`onwikiusername`),
				`checktime` = CURRENT_TIMESTAMP;
SQL;
		$stmt = $this->dbObject->prepare($query);
		$stmt->bindValue(':onwikiname', $onWikiName, PDO::PARAM_STR);
		$stmt->execute();
	}

	/**
	 * Queries the Wikimedia API to determine if the specified user is listed on the identification noticeboard.
	 *
	 * @param string $onWikiName The Wikipedia username of the user
	 *
	 * @return bool
	 * @category Security-Critical
	 */
	private function isIdentifiedOnWiki($onWikiName)
	{
		$strings = new StringFunctions();

		// First character of Wikipedia usernames is always capitalized.
		$onWikiName = $strings->ucfirst($onWikiName);

		$parameters = self::$apiQueryParameters;
		$parameters['pltitles'] = "User:" . $onWikiName;
		$response = $this->httpHelper->get($this->siteConfiguration->getMetaWikimediaWebServiceEndpoint(), $parameters);
		$response = json_decode($response, true);

		$page = @array_pop($response['query']['pages']);

		return @$page['links'][0]['title'] === "User:" . $onWikiName;
	}
}