userAgentDefault = self::UA_BROWSER; $this->referer = self::REF_GOOGLE; // set the request method if (in_array($method, array(1,2,4))) { $this->method = $method; } else { if (class_exists('HttpRequestPool')) { $this->method = self::METHOD_REQUEST_POOL; } elseif (function_exists('curl_multi_init')) { $this->method = self::METHOD_CURL_MULTI; } else { $this->method = self::METHOD_FILE_GET_CONTENTS; } } if ($this->method == self::METHOD_CURL_MULTI) { require_once(dirname(__FILE__).'/RollingCurl.php'); } // create cookie jar $this->cookieJar = new CookieJar(); // set request options (redirect must be 0) // HTTP PECL (http://php.net/manual/en/http.request.options.php) $this->requestOptions = array( 'timeout' => 15, 'connecttimeout' => 15, 'dns_cache_timeout' => 300, 'redirect' => 0 // we handle redirects manually so we can rewrite the new hashbang URLs that are creeping up over the web // TODO: test onprogress? ); if (is_array($requestOptions)) { $this->requestOptions = array_merge($this->requestOptions, $requestOptions); } // HTTP file_get_contents $this->httpContext = array( 'http' => array( 'ignore_errors' => true, 'timeout' => $this->requestOptions['timeout'], 'max_redirects' => $this->requestOptions['redirect'], 'header' => "Accept: */*\r\n" ) ); // HTTP cURL $this->curlOptions = array( CURLOPT_CONNECTTIMEOUT => $this->requestOptions['timeout'], CURLOPT_TIMEOUT => $this->requestOptions['timeout'] ); // Use proxy? if ($this->requestOptions['proxyhost']) { // For file_get_contents (see http://stackoverflow.com/a/1336419/407938) $this->httpContext['http']['proxy'] = 'tcp://'.$this->requestOptions['proxyhost']; $this->httpContext['http']['request_fulluri'] = true; // For cURL (see http://stackoverflow.com/a/9247672/407938) $this->curlOptions[CURLOPT_PROXY] = $this->requestOptions['proxyhost']; if (isset($this->requestOptions['proxyauth'])) { $this->httpContext['http']['header'] .= "Proxy-Authorization: Basic ".base64_encode($this->requestOptions['proxyauth'])."\r\n"; $this->curlOptions[CURLOPT_PROXYUSERPWD] = $this->requestOptions['proxyauth']; } } } protected function debug($msg) { if ($this->debug) { $mem = round(memory_get_usage()/1024, 2); $memPeak = round(memory_get_peak_usage()/1024, 2); echo '* ',$msg; if ($this->debugVerbose) echo ' - mem used: ',$mem," (peak: $memPeak)"; echo "\n"; ob_flush(); flush(); } } protected function getUserAgent($url, $asArray=false) { $host = @parse_url($url, PHP_URL_HOST); if (strtolower(substr($host, 0, 4)) == 'www.') { $host = substr($host, 4); } if ($host) { $try = array($host); $split = explode('.', $host); if (count($split) > 1) { array_shift($split); $try[] = '.'.implode('.', $split); } foreach ($try as $h) { if (isset($this->userAgentMap[$h])) { $ua = $this->userAgentMap[$h]; break; } } } if (!isset($ua)) $ua = $this->userAgentDefault; if ($asArray) { return array('User-Agent' => $ua); } else { return 'User-Agent: '.$ua; } } public function rewriteHashbangFragment($url) { // return $url if there's no '#!' if (strpos($url, '#!') === false) return $url; // split $url and rewrite // TODO: is SimplePie_IRI included? $iri = new SimplePie_IRI($url); $fragment = substr($iri->fragment, 1); // strip '!' $iri->fragment = null; if (isset($iri->query)) { parse_str($iri->query, $query); } else { $query = array(); } $query['_escaped_fragment_'] = (string)$fragment; $iri->query = str_replace('%2F', '/', http_build_query($query)); // needed for some sites return $iri->get_iri(); } public function getRedirectURLfromHTML($url, $html) { $redirect_url = $this->getMetaRefreshURL($url, $html); if (!$redirect_url) { $redirect_url = $this->getUglyURL($url, $html); } return $redirect_url; } public function getMetaRefreshURL($url, $html) { if ($html == '') return false; // if (!preg_match('!]+)["\']?!i', $html, $match)) { return false; } $redirect_url = $match[1]; if (preg_match('!^https?://!i', $redirect_url)) { // already absolute $this->debug('Meta refresh redirect found (http-equiv="refresh"), new URL: '.$redirect_url); return $redirect_url; } // absolutize redirect URL $base = new SimplePie_IRI($url); // remove '//' in URL path (causes URLs not to resolve properly) if (isset($base->path)) $base->path = preg_replace('!//+!', '/', $base->path); if ($absolute = SimplePie_IRI::absolutize($base, $redirect_url)) { $this->debug('Meta refresh redirect found (http-equiv="refresh"), new URL: '.$absolute); return $absolute; } return false; } public function getUglyURL($url, $html) { if ($html == '') return false; $found = false; foreach ($this->ajaxTriggers as $string) { if (stripos($html, $string)) { $found = true; break; } } if (!$found) return false; $iri = new SimplePie_IRI($url); if (isset($iri->query)) { parse_str($iri->query, $query); } else { $query = array(); } $query['_escaped_fragment_'] = ''; $iri->query = str_replace('%2F', '/', http_build_query($query)); // needed for some sites $ugly_url = $iri->get_iri(); $this->debug('AJAX trigger (meta name="fragment" content="!") found, new URL: '.$ugly_url); return $ugly_url; } public function removeFragment($url) { $pos = strpos($url, '#'); if ($pos === false) { return $url; } else { return substr($url, 0, $pos); } } public function rewriteUrls($url) { foreach ($this->rewriteUrls as $find => $action) { if (strpos($url, $find) !== false) { if (is_array($action)) { return strtr($url, $action); } } } return $url; } public function enableDebug($bool=true) { $this->debug = (bool)$bool; } public function minimiseMemoryUse($bool = true) { $this->minimiseMemoryUse = $bool; } public function setMaxParallelRequests($max) { $this->maxParallelRequests = $max; } public function validateUrl($url) { $url = filter_var($url, FILTER_SANITIZE_URL); $test = filter_var($url, FILTER_VALIDATE_URL, FILTER_FLAG_SCHEME_REQUIRED); // deal with bug http://bugs.php.net/51192 (present in PHP 5.2.13 and PHP 5.3.2) if ($test === false) { $test = filter_var(strtr($url, '-', '_'), FILTER_VALIDATE_URL, FILTER_FLAG_SCHEME_REQUIRED); } if ($test !== false && $test !== null && preg_match('!^https?://!', $url)) { return $url; } else { return false; } } public function fetchAll(array $urls) { $this->fetchAllOnce($urls, $isRedirect=false); $redirects = 0; while (!empty($this->redirectQueue) && ++$redirects <= $this->maxRedirects) { $this->debug("Following redirects #$redirects..."); $this->fetchAllOnce($this->redirectQueue, $isRedirect=true); } } // fetch all URLs without following redirects public function fetchAllOnce(array $urls, $isRedirect=false) { if (!$isRedirect) $urls = array_unique($urls); if (empty($urls)) return; ////////////////////////////////////////////////////// // parallel (HttpRequestPool) if ($this->method == self::METHOD_REQUEST_POOL) { $this->debug('Starting parallel fetch (HttpRequestPool)'); try { while (count($urls) > 0) { $this->debug('Processing set of '.min($this->maxParallelRequests, count($urls))); $subset = array_splice($urls, 0, $this->maxParallelRequests); $pool = new HttpRequestPool(); foreach ($subset as $orig => $url) { if (!$isRedirect) $orig = $url; unset($this->redirectQueue[$orig]); $this->debug("...$url"); if (!$isRedirect && isset($this->requests[$url])) { $this->debug("......in memory"); /* } elseif ($this->isCached($url)) { $this->debug("......is cached"); if (!$this->minimiseMemoryUse) { $this->requests[$url] = $this->getCached($url); } */ } else { $this->debug("......adding to pool"); $req_url = $this->rewriteUrls($url); $req_url = ($this->rewriteHashbangFragment) ? $this->rewriteHashbangFragment($req_url) : $req_url; $req_url = $this->removeFragment($req_url); if (!empty($this->headerOnlyTypes) && !isset($this->requests[$orig]['wrongGuess']) && $this->possibleUnsupportedType($req_url)) { $_meth = HttpRequest::METH_HEAD; } else { $_meth = HttpRequest::METH_GET; unset($this->requests[$orig]['wrongGuess']); } $httpRequest = new HttpRequest($req_url, $_meth, $this->requestOptions); // send cookies, if we have any if ($cookies = $this->cookieJar->getMatchingCookies($req_url)) { $this->debug("......sending cookies: $cookies"); $httpRequest->addHeaders(array('Cookie' => $cookies)); } //$httpRequest->addHeaders(array('User-Agent' => $this->userAgent)); $httpRequest->addHeaders($this->getUserAgent($req_url, true)); // add referer for picky sites $httpRequest->addheaders(array('Referer' => $this->referer)); $this->requests[$orig] = array('headers'=>null, 'body'=>null, 'httpRequest'=>$httpRequest); $this->requests[$orig]['original_url'] = $orig; $pool->attach($httpRequest); } } // did we get anything into the pool? if (count($pool) > 0) { $this->debug('Sending request...'); try { $pool->send(); } catch (HttpRequestPoolException $e) { // do nothing } $this->debug('Received responses'); foreach($subset as $orig => $url) { if (!$isRedirect) $orig = $url; $request = $this->requests[$orig]['httpRequest']; //$this->requests[$orig]['headers'] = $this->headersToString($request->getResponseHeader()); // getResponseHeader() doesn't return status line, so, for consistency... $this->requests[$orig]['headers'] = substr($request->getRawResponseMessage(), 0, $request->getResponseInfo('header_size')); // check content type // TODO: use getResponseHeader('content-type') or getResponseInfo() if ($this->headerOnlyType($this->requests[$orig]['headers'])) { $this->requests[$orig]['body'] = ''; $_header_only_type = true; $this->debug('Header only type returned'); } else { $this->requests[$orig]['body'] = $request->getResponseBody(); $_header_only_type = false; } $this->requests[$orig]['effective_url'] = $request->getResponseInfo('effective_url'); $this->requests[$orig]['status_code'] = $status_code = $request->getResponseCode(); // is redirect? if ((in_array($status_code, array(300, 301, 302, 303, 307)) || $status_code > 307 && $status_code < 400) && $request->getResponseHeader('location')) { $redirectURL = $request->getResponseHeader('location'); if (!preg_match('!^https?://!i', $redirectURL)) { $redirectURL = SimplePie_Misc::absolutize_url($redirectURL, $url); } if ($this->validateURL($redirectURL)) { $this->debug('Redirect detected. Valid URL: '.$redirectURL); // store any cookies $cookies = $request->getResponseHeader('set-cookie'); if ($cookies && !is_array($cookies)) $cookies = array($cookies); if ($cookies) $this->cookieJar->storeCookies($url, $cookies); $this->redirectQueue[$orig] = $redirectURL; } else { $this->debug('Redirect detected. Invalid URL: '.$redirectURL); } } elseif (!$_header_only_type && $request->getMethod() === HttpRequest::METH_HEAD) { // the response content-type did not match our 'header only' types, // but we'd issues a HEAD request because we assumed it would. So // let's queue a proper GET request for this item... $this->debug('Wrong guess at content-type, queing GET request'); $this->requests[$orig]['wrongGuess'] = true; $this->redirectQueue[$orig] = $this->requests[$orig]['effective_url']; } elseif (strpos($this->requests[$orig]['effective_url'], '_escaped_fragment_') === false) { // check for // for AJAX sites, e.g. Blogger with its dynamic views templates. // Based on Google's spec: https://developers.google.com/webmasters/ajax-crawling/docs/specification if (isset($this->requests[$orig]['body'])) { $redirectURL = $this->getRedirectURLfromHTML($this->requests[$orig]['effective_url'], substr($this->requests[$orig]['body'], 0, 150000)); if ($redirectURL) { $this->redirectQueue[$orig] = $redirectURL; } } } //die($url.' -multi- '.$request->getResponseInfo('effective_url')); $pool->detach($request); unset($this->requests[$orig]['httpRequest'], $request); /* if ($this->minimiseMemoryUse) { if ($this->cache($url)) { unset($this->requests[$url]); } } */ } } } } catch (HttpException $e) { $this->debug($e); return false; } } ////////////////////////////////////////////////////////// // parallel (curl_multi_*) elseif ($this->method == self::METHOD_CURL_MULTI) { $this->debug('Starting parallel fetch (curl_multi_*)'); while (count($urls) > 0) { $this->debug('Processing set of '.min($this->maxParallelRequests, count($urls))); $subset = array_splice($urls, 0, $this->maxParallelRequests); $pool = new RollingCurl(array($this, 'handleCurlResponse')); $pool->window_size = count($subset); foreach ($subset as $orig => $url) { if (!$isRedirect) $orig = $url; unset($this->redirectQueue[$orig]); $this->debug("...$url"); if (!$isRedirect && isset($this->requests[$url])) { $this->debug("......in memory"); /* } elseif ($this->isCached($url)) { $this->debug("......is cached"); if (!$this->minimiseMemoryUse) { $this->requests[$url] = $this->getCached($url); } */ } else { $this->debug("......adding to pool"); $req_url = $this->rewriteUrls($url); $req_url = ($this->rewriteHashbangFragment) ? $this->rewriteHashbangFragment($req_url) : $req_url; $req_url = $this->removeFragment($req_url); if (!empty($this->headerOnlyTypes) && !isset($this->requests[$orig]['wrongGuess']) && $this->possibleUnsupportedType($req_url)) { $_meth = 'HEAD'; } else { $_meth = 'GET'; unset($this->requests[$orig]['wrongGuess']); } $headers = array(); //$headers[] = 'User-Agent: '.$this->userAgent; $headers[] = $this->getUserAgent($req_url); // add referer for picky sites $headers[] = 'Referer: '.$this->referer; // send cookies, if we have any if ($cookies = $this->cookieJar->getMatchingCookies($req_url)) { $this->debug("......sending cookies: $cookies"); $headers[] = 'Cookie: '.$cookies; } $httpRequest = new RollingCurlRequest($req_url, $_meth, null, $headers, $this->curlOptions); $httpRequest->set_original_url($orig); $this->requests[$orig] = array('headers'=>null, 'body'=>null, 'httpRequest'=>$httpRequest); $this->requests[$orig]['original_url'] = $orig; // TODO: is this needed anymore? $pool->add($httpRequest); } } // did we get anything into the pool? if (count($pool) > 0) { $this->debug('Sending request...'); $pool->execute(); // this will call handleCurlResponse() and populate $this->requests[$orig] $this->debug('Received responses'); foreach($subset as $orig => $url) { if (!$isRedirect) $orig = $url; // $this->requests[$orig]['headers'] // $this->requests[$orig]['body'] // $this->requests[$orig]['effective_url'] // check content type if ($this->headerOnlyType($this->requests[$orig]['headers'])) { $this->requests[$orig]['body'] = ''; $_header_only_type = true; $this->debug('Header only type returned'); } else { $_header_only_type = false; } $status_code = $this->requests[$orig]['status_code']; if ((in_array($status_code, array(300, 301, 302, 303, 307)) || $status_code > 307 && $status_code < 400) && isset($this->requests[$orig]['location'])) { $redirectURL = $this->requests[$orig]['location']; if (!preg_match('!^https?://!i', $redirectURL)) { $redirectURL = SimplePie_Misc::absolutize_url($redirectURL, $url); } if ($this->validateURL($redirectURL)) { $this->debug('Redirect detected. Valid URL: '.$redirectURL); // store any cookies $cookies = $this->cookieJar->extractCookies($this->requests[$orig]['headers']); if (!empty($cookies)) $this->cookieJar->storeCookies($url, $cookies); $this->redirectQueue[$orig] = $redirectURL; } else { $this->debug('Redirect detected. Invalid URL: '.$redirectURL); } } elseif (!$_header_only_type && $this->requests[$orig]['method'] == 'HEAD') { // the response content-type did not match our 'header only' types, // but we'd issues a HEAD request because we assumed it would. So // let's queue a proper GET request for this item... $this->debug('Wrong guess at content-type, queing GET request'); $this->requests[$orig]['wrongGuess'] = true; $this->redirectQueue[$orig] = $this->requests[$orig]['effective_url']; } elseif (strpos($this->requests[$orig]['effective_url'], '_escaped_fragment_') === false) { // check for // for AJAX sites, e.g. Blogger with its dynamic views templates. // Based on Google's spec: https://developers.google.com/webmasters/ajax-crawling/docs/specification if (isset($this->requests[$orig]['body'])) { $redirectURL = $this->getRedirectURLfromHTML($this->requests[$orig]['effective_url'], substr($this->requests[$orig]['body'], 0, 150000)); if ($redirectURL) { $this->redirectQueue[$orig] = $redirectURL; } } } // die($url.' -multi- '.$request->getResponseInfo('effective_url')); unset($this->requests[$orig]['httpRequest'], $this->requests[$orig]['method']); } } } } ////////////////////////////////////////////////////// // sequential (file_get_contents) else { $this->debug('Starting sequential fetch (file_get_contents)'); $this->debug('Processing set of '.count($urls)); foreach ($urls as $orig => $url) { if (!$isRedirect) $orig = $url; unset($this->redirectQueue[$orig]); $this->debug("...$url"); if (!$isRedirect && isset($this->requests[$url])) { $this->debug("......in memory"); /* } elseif ($this->isCached($url)) { $this->debug("......is cached"); if (!$this->minimiseMemoryUse) { $this->requests[$url] = $this->getCached($url); } */ } else { $this->debug("Sending request for $url"); $this->requests[$orig]['original_url'] = $orig; $req_url = $this->rewriteUrls($url); $req_url = ($this->rewriteHashbangFragment) ? $this->rewriteHashbangFragment($req_url) : $req_url; $req_url = $this->removeFragment($req_url); // send cookies, if we have any $httpContext = $this->httpContext; $httpContext['http']['header'] .= $this->getUserAgent($req_url)."\r\n"; // add referer for picky sites $httpContext['http']['header'] .= 'Referer: '.$this->referer."\r\n"; if ($cookies = $this->cookieJar->getMatchingCookies($req_url)) { $this->debug("......sending cookies: $cookies"); $httpContext['http']['header'] .= 'Cookie: '.$cookies."\r\n"; } if (false !== ($html = @file_get_contents($req_url, false, stream_context_create($httpContext)))) { $this->debug('Received response'); // get status code if (!isset($http_response_header[0]) || !preg_match('!^HTTP/\d+\.\d+\s+(\d+)!', trim($http_response_header[0]), $match)) { $this->debug('Error: no status code found'); // TODO: handle error - no status code } else { $this->requests[$orig]['headers'] = $this->headersToString($http_response_header, false); // check content type if ($this->headerOnlyType($this->requests[$orig]['headers'])) { $this->requests[$orig]['body'] = ''; } else { $this->requests[$orig]['body'] = $html; } $this->requests[$orig]['effective_url'] = $req_url; $this->requests[$orig]['status_code'] = $status_code = (int)$match[1]; unset($match); // handle redirect if (preg_match('/^Location:(.*?)$/mi', $this->requests[$orig]['headers'], $match)) { $this->requests[$orig]['location'] = trim($match[1]); } if ((in_array($status_code, array(300, 301, 302, 303, 307)) || $status_code > 307 && $status_code < 400) && isset($this->requests[$orig]['location'])) { $redirectURL = $this->requests[$orig]['location']; if (!preg_match('!^https?://!i', $redirectURL)) { $redirectURL = SimplePie_Misc::absolutize_url($redirectURL, $url); } if ($this->validateURL($redirectURL)) { $this->debug('Redirect detected. Valid URL: '.$redirectURL); // store any cookies $cookies = $this->cookieJar->extractCookies($this->requests[$orig]['headers']); if (!empty($cookies)) $this->cookieJar->storeCookies($url, $cookies); $this->redirectQueue[$orig] = $redirectURL; } else { $this->debug('Redirect detected. Invalid URL: '.$redirectURL); } } elseif (strpos($this->requests[$orig]['effective_url'], '_escaped_fragment_') === false) { // check for // for AJAX sites, e.g. Blogger with its dynamic views templates. // Based on Google's spec: https://developers.google.com/webmasters/ajax-crawling/docs/specification if (isset($this->requests[$orig]['body'])) { $redirectURL = $this->getRedirectURLfromHTML($this->requests[$orig]['effective_url'], substr($this->requests[$orig]['body'], 0, 150000)); if ($redirectURL) { $this->redirectQueue[$orig] = $redirectURL; } } } } } else { $this->debug('Error retrieving URL'); //print_r($req_url); //print_r($http_response_header); //print_r($html); // TODO: handle error - failed to retrieve URL } } } } } public function handleCurlResponse($response, $info, $request) { $orig = $request->url_original; $this->requests[$orig]['headers'] = substr($response, 0, $info['header_size']); $this->requests[$orig]['body'] = substr($response, $info['header_size']); $this->requests[$orig]['method'] = $request->method; $this->requests[$orig]['effective_url'] = $info['url']; $this->requests[$orig]['status_code'] = (int)$info['http_code']; if (preg_match('/^Location:(.*?)$/mi', $this->requests[$orig]['headers'], $match)) { $this->requests[$orig]['location'] = trim($match[1]); } } protected function headersToString(array $headers, $associative=true) { if (!$associative) { return implode("\n", $headers); } else { $str = ''; foreach ($headers as $key => $val) { if (is_array($val)) { foreach ($val as $v) $str .= "$key: $v\n"; } else { $str .= "$key: $val\n"; } } return rtrim($str); } } public function get($url, $remove=false, $gzdecode=true) { $url = "$url"; if (isset($this->requests[$url]) && isset($this->requests[$url]['body'])) { $this->debug("URL already fetched - in memory ($url, effective: {$this->requests[$url]['effective_url']})"); $response = $this->requests[$url]; /* } elseif ($this->isCached($url)) { $this->debug("URL already fetched - in disk cache ($url)"); $response = $this->getCached($url); $this->requests[$url] = $response; */ } else { $this->debug("Fetching URL ($url)"); $this->fetchAll(array($url)); if (isset($this->requests[$url]) && isset($this->requests[$url]['body'])) { $response = $this->requests[$url]; } else { $this->debug("Request failed"); $response = false; } } /* if ($this->minimiseMemoryUse && $response) { $this->cache($url); unset($this->requests[$url]); } */ if ($remove && $response) unset($this->requests[$url]); if ($gzdecode && stripos($response['headers'], 'Content-Encoding: gzip')) { if ($html = @gzdecode($response['body'])) { $response['body'] = $html; } } return $response; } public function parallelSupport() { return class_exists('HttpRequestPool') || function_exists('curl_multi_init'); } private function headerOnlyType($headers) { if (preg_match('!^Content-Type:\s*(([a-z-]+)/([^;\r\n ]+))!im', $headers, $match)) { // look for full mime type (e.g. image/jpeg) or just type (e.g. image) $match[1] = strtolower(trim($match[1])); $match[2] = strtolower(trim($match[2])); foreach (array($match[1], $match[2]) as $mime) { if (in_array($mime, $this->headerOnlyTypes)) return true; } } return false; } private function possibleUnsupportedType($url) { $path = @parse_url($url, PHP_URL_PATH); if ($path && strpos($path, '.') !== false) { $ext = strtolower(trim(pathinfo($path, PATHINFO_EXTENSION))); return in_array($ext, $this->headerOnlyClues); } return false; } } // gzdecode from http://www.php.net/manual/en/function.gzdecode.php#82930 if (!function_exists('gzdecode')) { function gzdecode($data,&$filename='',&$error='',$maxlength=null) { $len = strlen($data); if ($len < 18 || strcmp(substr($data,0,2),"\x1f\x8b")) { $error = "Not in GZIP format."; return null; // Not GZIP format (See RFC 1952) } $method = ord(substr($data,2,1)); // Compression method $flags = ord(substr($data,3,1)); // Flags if ($flags & 31 != $flags) { $error = "Reserved bits not allowed."; return null; } // NOTE: $mtime may be negative (PHP integer limitations) $mtime = unpack("V", substr($data,4,4)); $mtime = $mtime[1]; $xfl = substr($data,8,1); $os = substr($data,8,1); $headerlen = 10; $extralen = 0; $extra = ""; if ($flags & 4) { // 2-byte length prefixed EXTRA data in header if ($len - $headerlen - 2 < 8) { return false; // invalid } $extralen = unpack("v",substr($data,8,2)); $extralen = $extralen[1]; if ($len - $headerlen - 2 - $extralen < 8) { return false; // invalid } $extra = substr($data,10,$extralen); $headerlen += 2 + $extralen; } $filenamelen = 0; $filename = ""; if ($flags & 8) { // C-style string if ($len - $headerlen - 1 < 8) { return false; // invalid } $filenamelen = strpos(substr($data,$headerlen),chr(0)); if ($filenamelen === false || $len - $headerlen - $filenamelen - 1 < 8) { return false; // invalid } $filename = substr($data,$headerlen,$filenamelen); $headerlen += $filenamelen + 1; } $commentlen = 0; $comment = ""; if ($flags & 16) { // C-style string COMMENT data in header if ($len - $headerlen - 1 < 8) { return false; // invalid } $commentlen = strpos(substr($data,$headerlen),chr(0)); if ($commentlen === false || $len - $headerlen - $commentlen - 1 < 8) { return false; // Invalid header format } $comment = substr($data,$headerlen,$commentlen); $headerlen += $commentlen + 1; } $headercrc = ""; if ($flags & 2) { // 2-bytes (lowest order) of CRC32 on header present if ($len - $headerlen - 2 < 8) { return false; // invalid } $calccrc = crc32(substr($data,0,$headerlen)) & 0xffff; $headercrc = unpack("v", substr($data,$headerlen,2)); $headercrc = $headercrc[1]; if ($headercrc != $calccrc) { $error = "Header checksum failed."; return false; // Bad header CRC } $headerlen += 2; } // GZIP FOOTER $datacrc = unpack("V",substr($data,-8,4)); $datacrc = sprintf('%u',$datacrc[1] & 0xFFFFFFFF); $isize = unpack("V",substr($data,-4)); $isize = $isize[1]; // decompression: $bodylen = $len-$headerlen-8; if ($bodylen < 1) { // IMPLEMENTATION BUG! return null; } $body = substr($data,$headerlen,$bodylen); $data = ""; if ($bodylen > 0) { switch ($method) { case 8: // Currently the only supported compression method: $data = gzinflate($body,$maxlength); break; default: $error = "Unknown compression method."; return false; } } // zero-byte body content is allowed // Verifiy CRC32 $crc = sprintf("%u",crc32($data)); $crcOK = $crc == $datacrc; $lenOK = $isize == strlen($data); if (!$lenOK || !$crcOK) { $error = ( $lenOK ? '' : 'Length check FAILED. ') . ( $crcOK ? '' : 'Checksum FAILED.'); return false; } return $data; } }