<?php
require_once('wordfenceConstants.php');
require_once('wordfenceClass.php');
require_once('wordfenceURLHoover.php');
class wordfenceScanner {
	/*
	 * Mask to return all patterns in the exclusion list.
	 * @var int
	 */
	const EXCLUSION_PATTERNS_ALL = PHP_INT_MAX;
	/*
	 * Mask for patterns that the user has added.
	 */
	const EXCLUSION_PATTERNS_USER = 0x1;
	/*
	 * Mask for patterns that should be excluded from the known files scan.
	 */
	const EXCLUSION_PATTERNS_KNOWN_FILES = 0x2;
	/*
	 * Mask for patterns that should be excluded from the malware scan.
	 */
	const EXCLUSION_PATTERNS_MALWARE = 0x4;

	//serialized:
	protected $path = '';
	protected $results = array(); 
	public $errorMsg = false;
	protected $apiKey = false;
	protected $wordpressVersion = '';
	protected $totalFilesScanned = 0;
	protected $startTime = false;
	protected $lastStatusTime = false;
	protected $patterns = "";
	protected $api = false;
	protected static $excludePatterns = array();
	protected static $builtinExclusions = array(
											array('pattern' => 'wp-includes/version.php', 'include' => self::EXCLUSION_PATTERNS_KNOWN_FILES), //Excluded from the known files scan because non-en_US installations will have extra content that fails the check, still in malware scan
											);
	/** @var wfScanEngine */
	protected $scanEngine;

	public function __sleep(){
		return array('path', 'results', 'errorMsg', 'apiKey', 'wordpressVersion', 'urlHoover', 'totalFilesScanned',
			'startTime', 'lastStatusTime', 'patterns', 'scanEngine');
	}
	public function __wakeup(){
	}
	public function __construct($apiKey, $wordpressVersion, $path){
		$this->apiKey = $apiKey;
		$this->wordpressVersion = $wordpressVersion;
		$this->api = new wfAPI($this->apiKey, $this->wordpressVersion);
		if($path[strlen($path) - 1] != '/'){
			$path .= '/';
		}
		$this->path = $path;
		
		
		$this->results = array();
		$this->errorMsg = false;
		//First extract hosts or IP's and their URL's into $this->hostsFound and URL's into $this->urlsFound
		$this->urlHoover = new wordfenceURLHoover($this->apiKey, $this->wordpressVersion);
		$this->setupSigs();
	}

	/**
	 * Get scan regexes from noc1 and add any user defined regexes, including descriptions, ID's and time added.
	 * @todo add caching to this.
	 * @throws Exception
	 */
	protected function setupSigs() {
		$this->api = new wfAPI($this->apiKey, $this->wordpressVersion);
		$sigData = $this->api->call('get_patterns', array(), array());
		if(! (is_array($sigData) && isset($sigData['rules'])) ){
			throw new Exception("Wordfence could not get the attack signature patterns from the scanning server.");
		}

		if (is_array($sigData['rules'])) {
			$finalPattern = '/';
			foreach ($sigData['rules'] as $signatureRow) {
				list($id, $timeAdded, $pattern, $description) = $signatureRow;
				$finalPattern .= ($pattern . '|');
			}
			$finalPattern = substr($finalPattern, 0, -1) . '/i';
			if(@preg_match($finalPattern, null) === false){
				throw new Exception("The regex Wordfence received from it's servers is invalid. The pattern is: " . $finalPattern);
			}
		}

		$extra = wfConfig::get('scan_include_extra');
		if (!empty($extra)) {
			$regexs = explode("\n", $extra);
			$id = 1000001;
			foreach($regexs as $r){
				$r = rtrim($r, "\r");
				try {
					preg_match('/' . $r . '/i', "");
				} catch(Exception $e){
					throw new Exception("The following user defined scan pattern has an error: $r");
				}
				$sigData['rules'][] = array($id++, time(), $r, "User defined scan pattern");
			}
		}

		$this->patterns = $sigData;
		if (isset($this->patterns['signatureUpdateTime'])) {
			wfConfig::set('signatureUpdateTime', $this->patterns['signatureUpdateTime']);
		}
	}

	/**
	 * Return regular expression to exclude files or false if
	 * there is no pattern
	 *
	 * @param $whichPatterns int Bitmask indicating which patterns to include.
	 * @return string|boolean
	 */
	public static function getExcludeFilePattern($whichPatterns = self::EXCLUSION_PATTERNS_USER) {
		if (isset(self::$excludePatterns[$whichPatterns])) {
			return self::$excludePatterns[$whichPatterns];
		}
		
		$exParts = array();
		if (($whichPatterns & self::EXCLUSION_PATTERNS_USER) > 0)
		{
			if (wfConfig::get('scan_exclude', false))
			{
				$exParts = explode("\n", wfUtils::cleanupOneEntryPerLine(wfConfig::get('scan_exclude')));
			}
		}

		foreach (self::$builtinExclusions as $pattern) {
			if (($pattern['include'] & $whichPatterns) > 0) {
				$exParts[] = $pattern['pattern'];
			}
		}

		if (!empty($exParts)) {
			foreach($exParts as &$exPart){
				$exPart = preg_quote(trim($exPart), '/');
				$exPart = preg_replace('/\\\\\*/', '.*', $exPart);
			}

			//self::$excludePattern = '/^(?:' . implode('|', array_filter($exParts)) . ')$/i';
			self::$excludePatterns[$whichPatterns] = '/(?:' . implode('|', array_filter($exParts)) . ')$/i';
		}
		else {
			self::$excludePatterns[$whichPatterns]= false;
		}

		return self::$excludePatterns[$whichPatterns];
	}

	/**
	 * @param wfScanEngine $forkObj
	 * @return array
	 */
	public function scan($forkObj){
		$this->scanEngine = $forkObj;
		$loader = $this->scanEngine->getKnownFilesLoader();
		if(! $this->startTime){
			$this->startTime = microtime(true);
		}
		if(! $this->lastStatusTime){
			$this->lastStatusTime = microtime(true);
		}
		$db = new wfDB();
		$lastCount = 'whatever';
		$excludePattern = self::getExcludeFilePattern(self::EXCLUSION_PATTERNS_USER & self::EXCLUSION_PATTERNS_MALWARE);
		while(true){
			$thisCount = $db->querySingle("select count(*) from " . $db->prefix() . "wfFileMods where oldMD5 != newMD5 and knownFile=0");
			if($thisCount == $lastCount){
				//count should always be decreasing. If not, we're in an infinite loop so lets catch it early
				break;
			}
			$lastCount = $thisCount;
			$res1 = $db->querySelect("select filename, filenameMD5, hex(newMD5) as newMD5 from " . $db->prefix() . "wfFileMods where oldMD5 != newMD5 and knownFile=0 limit 500");
			if(sizeof($res1) < 1){
				break;
			}
			foreach($res1 as $rec1){
				$db->queryWrite("update " . $db->prefix() . "wfFileMods set oldMD5 = newMD5 where filenameMD5='%s'", $rec1['filenameMD5']); //A way to mark as scanned so that if we come back from a sleep we don't rescan this one.
				$file = $rec1['filename'];
				if($excludePattern && preg_match($excludePattern, $file)){
					continue;
				}
				$fileSum = $rec1['newMD5'];

				if(! file_exists($this->path . $file)){
					continue;
				}
				$fileExt = '';
				if(preg_match('/\.([a-zA-Z\d\-]{1,7})$/', $file, $matches)){
					$fileExt = strtolower($matches[1]);
				}
				$isPHP = false;
				if(preg_match('/\.(?:php(?:\d+)?|phtml)(\.|$)/i', $file)) {
					$isPHP = true;
				}
				$dontScanForURLs = false;
				if( (! wfConfig::get('scansEnabled_highSense')) && preg_match('/^(?:\.htaccess|wp\-config\.php)$/', $file)) {
					$dontScanForURLs = true;
				}
				if(! $isPHP && preg_match('/^(?:jpg|jpeg|mp3|avi|m4v|gif|png|sql|tbz2?|bz2?|xz|zip|tgz|gz|tar|log|err\d+)$/', $fileExt) && (! wfConfig::get('scansEnabled_scanImages')) ){
					continue;
				}
				if( (! wfConfig::get('scansEnabled_highSense')) && strtolower($fileExt) == 'sql'){ //
					continue;
				}
				if(wfUtils::fileTooBig($this->path . $file)){ //We can't use filesize on 32 bit systems for files > 2 gigs
					//We should not need this check because files > 2 gigs are not hashed and therefore won't be received back as unknowns from the API server
					//But we do it anyway to be safe.
					wordfence::status(2, 'error', "Encountered file that is too large: $file - Skipping.");
					continue;
				}
				wfUtils::beginProcessingFile($file);

				$fsize = filesize($this->path . $file); //Checked if too big above
				if($fsize > 1000000){
					$fsize = sprintf('%.2f', ($fsize / 1000000)) . "M";
				} else {
					$fsize = $fsize . "B";
				}
				if (function_exists('memory_get_usage')) {
					wordfence::status(4, 'info', "Scanning contents: $file (Size:$fsize Mem:" . sprintf('%.1f', memory_get_usage(true) / (1024 * 1024)) . "M)");
				} else {
					wordfence::status(4, 'info', "Scanning contents: $file (Size: $fsize)");
				}

				$stime = microtime(true);
				$fh = @fopen($this->path . $file, 'r');
				if(! $fh){
					continue;
				}
				$totalRead = 0;

				$dataForFile = $this->dataForFile($file);

				while(! feof($fh)){
					$data = fread($fh, 1 * 1024 * 1024); //read 1 megs max per chunk
					$totalRead += strlen($data);
					if($totalRead < 1){
						break;
					}
					if($isPHP || wfConfig::get('scansEnabled_scanImages') ){
						if(strpos($data, '$allowed'.'Sites') !== false && strpos($data, "define ('VER"."SION', '1.") !== false && strpos($data, "TimThum"."b script created by") !== false){
							if(! $this->isSafeFile($this->path . $file)){
								$this->addResult(array(
									'type' => 'file',
									'severity' => 1,
									'ignoreP' => $this->path . $file,
									'ignoreC' => $fileSum,
									'shortMsg' => "File is an old version of TimThumb which is vulnerable.",
									'longMsg' => "This file appears to be an old version of the TimThumb script which makes your system vulnerable to attackers. Please upgrade the theme or plugin that uses this or remove it.",
									'data' => array_merge(array(
										'file' => $file,
									), $dataForFile),
								));
								break;
							}
						} else if(strpos($file, 'lib/wordfenceScanner.php') === false){ // && preg_match($this->patterns['sigPattern'], $data, $matches)){
							$regexMatched = false;
							foreach($this->patterns['rules'] as $rule){
								if(preg_match('/(' . $rule[2] . ')/i', $data, $matches)){
									if(! $this->isSafeFile($this->path . $file)){
										$this->addResult(array(
											'type' => 'file',
											'severity' => 1,
											'ignoreP' => $this->path . $file,
											'ignoreC' => $fileSum,
											'shortMsg' => "File appears to be malicious: " . esc_html($file),
											'longMsg' => "This file appears to be installed by a hacker to perform malicious activity. If you know about this file you can choose to ignore it to exclude it from future scans. The text we found in this file that matches a known malicious file is: <strong style=\"color: #F00;\">\"" . esc_html((strlen($matches[1]) > 200 ? substr($matches[1], 0, 200) . '...' : $matches[1])) . "\"</strong>. The infection type is: <strong>" . esc_html($rule[3]) . '</strong>',
											'data' => array_merge(array(
												'file' => $file,
											), $dataForFile),
										));
										$regexMatched = true;
										break;
									}
								}
							}
							if($regexMatched){ break; }
						}
						if(wfConfig::get('scansEnabled_highSense')){
							$badStringFound = false;
							if(strpos($data, $this->patterns['badstrings'][0]) !== false){
								for($i = 1; $i < sizeof($this->patterns['badstrings']); $i++){
									if(strpos($data, $this->patterns['badstrings'][$i]) !== false){
										$badStringFound = $this->patterns['badstrings'][$i];
										break;
									}
								}
							}
							if($badStringFound){
								if(! $this->isSafeFile($this->path . $file)){
									$this->addResult(array(
										'type' => 'file',
										'severity' => 1,
										'ignoreP' => $this->path . $file,
										'ignoreC' => $fileSum,
										'shortMsg' => "This file may contain malicious executable code: " . esc_html($this->path . $file),
										'longMsg' => "This file is a PHP executable file and contains the word 'eval' (without quotes) and the word '" . esc_html($badStringFound) . "' (without quotes). The eval() function along with an encoding function like the one mentioned are commonly used by hackers to hide their code. If you know about this file you can choose to ignore it to exclude it from future scans.",
										'data' => array_merge(array(
											'file' => $file,
										), $dataForFile),
										));
									break;
								}
							}
						}
						if(! $dontScanForURLs){
							$this->urlHoover->hoover($file, $data);
						}
					} else {
						if(! $dontScanForURLs){
							$this->urlHoover->hoover($file, $data);
						}
					}

					if($totalRead > 2 * 1024 * 1024){
						break;
					}
				}
				fclose($fh);
				$this->totalFilesScanned++;
				if(microtime(true) - $this->lastStatusTime > 1){
					$this->lastStatusTime = microtime(true);
					$this->writeScanningStatus();
				}
				$forkObj->forkIfNeeded();
			}
		}
		$this->writeScanningStatus();
		wordfence::status(2, 'info', "Asking Wordfence to check URL's against malware list.");
		$hooverResults = $this->urlHoover->getBaddies();
		if($this->urlHoover->errorMsg){
			$this->errorMsg = $this->urlHoover->errorMsg;
			return false;
		}
		$this->urlHoover->cleanup();
		foreach($hooverResults as $file => $hresults){
			$dataForFile = $this->dataForFile($file);

			foreach($hresults as $result){
				if(preg_match('/wfBrowscapCache\.php$/', $file)){
					continue;
				}
				if($result['badList'] == 'goog-malware-shavar'){
					if(! $this->isSafeFile($this->path . $file)){
						$this->addResult(array(
							'type' => 'file',
							'severity' => 1,
							'ignoreP' => $this->path . $file,
							'ignoreC' => md5_file($this->path . $file),
							'shortMsg' => "File contains suspected malware URL: " . esc_html($this->path . $file),
							'longMsg' => "This file contains a suspected malware URL listed on Google's list of malware sites. Wordfence decodes " . esc_html($this->patterns['word3']) . " when scanning files so the URL may not be visible if you view this file. The URL is: " . esc_html($result['URL']) . " - More info available at <a href=\"http://safebrowsing.clients.google.com/safebrowsing/diagnostic?site=" . urlencode($result['URL']) . "&client=googlechrome&hl=en-US\" target=\"_blank\">Google Safe Browsing diagnostic page</a>.",
							'data' => array_merge(array(
								'file' => $file,
								'badURL' => $result['URL'],
								'gsb' => 'goog-malware-shavar'
							), $dataForFile),
						));
					}
				} else if($result['badList'] == 'googpub-phish-shavar'){
					if(! $this->isSafeFile($this->path . $file)){
						$this->addResult(array(
							'type' => 'file',
							'severity' => 1,
							'ignoreP' => $this->path . $file,
							'ignoreC' => md5_file($this->path . $file),
							'shortMsg' => "File contains suspected phishing URL: " . esc_html($this->path . $file),
							'longMsg' => "This file contains a URL that is a suspected phishing site that is currently listed on Google's list of known phishing sites. The URL is: " . esc_html($result['URL']),
							'data' => array_merge(array(
								'file' => $file,
								'badURL' => $result['URL'],
								'gsb' => 'googpub-phish-shavar'
							), $dataForFile),
						));
					}
				}
			}
		}
		wfUtils::endProcessingFile();

		return $this->results;
	}

	protected function writeScanningStatus() {
		wordfence::status(2, 'info', "Scanned contents of " . $this->totalFilesScanned . " additional files at " . sprintf('%.2f', ($this->totalFilesScanned / (microtime(true) - $this->startTime))) . " per second");
	}

	protected function addResult($result) {
		for ($i = 0; $i < sizeof($this->results); $i++) {
			if ($this->results[$i]['type'] == 'file' && $this->results[$i]['data']['file'] == $result['data']['file']) {
				if ($this->results[$i]['severity'] > $result['severity']) {
					$this->results[$i] = $result; //Overwrite with more severe results
				}
				return;
			}
		}
		//We don't have a results for this file so append
		$this->results[] = $result;
	}
	private function isSafeFile($file){
		if(! $this->api){
			$this->api = new wfAPI($this->apiKey, $this->wordpressVersion);
		}
			
		$wfHash = wordfenceHash::wfHash($file);
		$result = $this->api->call('is_safe_file', array(), array('shac' => strtoupper($wfHash[1])));
		if(isset($result['isSafe']) && $result['isSafe'] == 1){
			return true;
		}
		return false;
	}

	/**
	 * @param string $file
	 * @return array
	 */
	private function dataForFile($file) {
		$loader = $this->scanEngine->getKnownFilesLoader();
		$data = array();
		if ($isKnownFile = $loader->isKnownFile($file)) {
			if ($loader->isKnownCoreFile($file)) {
				$data['cType'] = 'core';

			} else if ($loader->isKnownPluginFile($file)) {
				$data['cType'] = 'plugin';
				list($itemName, $itemVersion, $cKey) = $loader->getKnownPluginData($file);
				$data = array_merge($data, array(
					'cName'    => $itemName,
					'cVersion' => $itemVersion,
					'cKey'     => $cKey
				));

			} else if ($loader->isKnownThemeFile($file)) {
				$data['cType'] = 'theme';
				list($itemName, $itemVersion, $cKey) = $loader->getKnownThemeData($file);
				$data = array_merge($data, array(
					'cName'    => $itemName,
					'cVersion' => $itemVersion,
					'cKey'     => $cKey
				));
			}
		}

		$data['canDiff'] = $isKnownFile;
		$data['canFix'] = $isKnownFile;
		$data['canDelete'] = !$isKnownFile;

		return $data;
	}
}


?>
