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<?php // This file is part of Moodle - http://moodle.org/ // // Moodle 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, either version 3 of the License, or // (at your option) any later version. // // Moodle 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. // // You should have received a copy of the GNU General Public License // along with Moodle. If not, see <http://www.gnu.org/licenses/>. /** * Implementation of zip file archive. * * @package core_files * @copyright 2008 Petr Skoda (http://skodak.org) * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later */ defined('MOODLE_INTERNAL') || die(); require_once("$CFG->libdir/filestorage/file_archive.php"); /** * Zip file archive class. * * @package core_files * @category files * @copyright 2008 Petr Skoda (http://skodak.org) * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later */ class zip_archive extends file_archive { /** @var string Pathname of archive */ protected $archivepathname = null; /** @var int archive open mode */ protected $mode = null; /** @var int Used memory tracking */ protected $usedmem = 0; /** @var int Iteration position */ protected $pos = 0; /** @var ZipArchive instance */ protected $za; /** @var bool was this archive modified? */ protected $modified = false; /** @var array unicode decoding array, created by decoding zip file */ protected $namelookup = null; /** @var string base64 encoded contents of empty zip file */ protected static $emptyzipcontent = 'UEsFBgAAAAAAAAAAAAAAAAAAAAAAAA=='; /** @var bool ugly hack for broken empty zip handling in < PHP 5.3.10 */ protected $emptyziphack = false; /** * Create new zip_archive instance. */ public function __construct() { $this->encoding = null; // Autodetects encoding by default. } /** * Open or create archive (depending on $mode). * * @todo MDL-31048 return error message * @param string $archivepathname * @param int $mode OPEN, CREATE or OVERWRITE constant * @param string $encoding archive local paths encoding, empty means autodetect * @return bool success */ public function open($archivepathname, $mode=file_archive::CREATE, $encoding=null) { $this->close(); $this->usedmem = 0; $this->pos = 0; $this->encoding = $encoding; $this->mode = $mode; $this->za = new ZipArchive(); switch($mode) { case file_archive::OPEN: $flags = 0; break; case file_archive::OVERWRITE: $flags = ZIPARCHIVE::CREATE | ZIPARCHIVE::OVERWRITE; break; //changed in PHP 5.2.8 case file_archive::CREATE: default : $flags = ZIPARCHIVE::CREATE; break; } $result = $this->za->open($archivepathname, $flags); if ($flags == 0 and $result === ZIPARCHIVE::ER_NOZIP and filesize($archivepathname) === 22) { // Legacy PHP versions < 5.3.10 can not deal with empty zip archives. if (file_get_contents($archivepathname) === base64_decode(self::$emptyzipcontent)) { if ($temp = make_temp_directory('zip')) { $this->emptyziphack = tempnam($temp, 'zip'); $this->za = new ZipArchive(); $result = $this->za->open($this->emptyziphack, ZIPARCHIVE::CREATE); } } } if ($result === true) { if (file_exists($archivepathname)) { $this->archivepathname = realpath($archivepathname); } else { $this->archivepathname = $archivepathname; } return true; } else { $message = 'Unknown error.'; switch ($result) { case ZIPARCHIVE::ER_EXISTS: $message = 'File already exists.'; break; case ZIPARCHIVE::ER_INCONS: $message = 'Zip archive inconsistent.'; break; case ZIPARCHIVE::ER_INVAL: $message = 'Invalid argument.'; break; case ZIPARCHIVE::ER_MEMORY: $message = 'Malloc failure.'; break; case ZIPARCHIVE::ER_NOENT: $message = 'No such file.'; break; case ZIPARCHIVE::ER_NOZIP: $message = 'Not a zip archive.'; break; case ZIPARCHIVE::ER_OPEN: $message = 'Can\'t open file.'; break; case ZIPARCHIVE::ER_READ: $message = 'Read error.'; break; case ZIPARCHIVE::ER_SEEK: $message = 'Seek error.'; break; } debugging($message.': '.$archivepathname, DEBUG_DEVELOPER); $this->za = null; $this->archivepathname = null; return false; } } /** * Normalize $localname, always keep in utf-8 encoding. * * @param string $localname name of file in utf-8 encoding * @return string normalised compressed file or directory name */ protected function mangle_pathname($localname) { $result = str_replace('\\', '/', $localname); // no MS \ separators $result = preg_replace('/\.\.+\//', '', $result); // Cleanup any potential ../ transversal (any number of dots). $result = preg_replace('/\.\.+/', '.', $result); // Join together any number of consecutive dots. $result = ltrim($result, '/'); // no leading slash if ($result === '.') { $result = ''; } return $result; } /** * Tries to convert $localname into utf-8 * please note that it may fail really badly. * The resulting file name is cleaned. * * @param string $localname name (encoding is read from zip file or guessed) * @return string in utf-8 */ protected function unmangle_pathname($localname) { $this->init_namelookup(); if (!isset($this->namelookup[$localname])) { $name = $localname; // This should not happen. if (!empty($this->encoding) and $this->encoding !== 'utf-8') { $name = @core_text::convert($name, $this->encoding, 'utf-8'); } $name = str_replace('\\', '/', $name); // no MS \ separators $name = clean_param($name, PARAM_PATH); // only safe chars return ltrim($name, '/'); // no leading slash } return $this->namelookup[$localname]; } /** * Close archive, write changes to disk. * * @return bool success */ public function close() { if (!isset($this->za)) { return false; } if ($this->emptyziphack) { @$this->za->close(); $this->za = null; $this->mode = null; $this->namelookup = null; $this->modified = false; @unlink($this->emptyziphack); $this->emptyziphack = false; return true; } else if ($this->za->numFiles == 0) { // PHP can not create empty archives, so let's fake it. @$this->za->close(); $this->za = null; $this->mode = null; $this->namelookup = null; $this->modified = false; // If the existing archive is already empty, we didn't change it. Don't bother completing a save. // This is important when we are inspecting archives that we might not have write permission to. if (@filesize($this->archivepathname) == 22 && @file_get_contents($this->archivepathname) === base64_decode(self::$emptyzipcontent)) { return true; } @unlink($this->archivepathname); $data = base64_decode(self::$emptyzipcontent); if (!file_put_contents($this->archivepathname, $data)) { return false; } return true; } $res = $this->za->close(); $this->za = null; $this->mode = null; $this->namelookup = null; if ($this->modified) { $this->fix_utf8_flags(); $this->modified = false; } return $res; } /** * Returns file stream for reading of content. * * @param int $index index of file * @return resource|bool file handle or false if error */ public function get_stream($index) { if (!isset($this->za)) { return false; } $name = $this->za->getNameIndex($index); if ($name === false) { return false; } return $this->za->getStream($name); } /** * Returns file information. * * @param int $index index of file * @return stdClass|bool info object or false if error */ public function get_info($index) { if (!isset($this->za)) { return false; } // Need to use the ZipArchive's numfiles, as $this->count() relies on this function to count actual files (skipping OSX junk). if ($index < 0 or $index >=$this->za->numFiles) { return false; } // PHP 5.6 introduced encoding guessing logic, we need to fall back // to raw ZIP_FL_ENC_RAW (== 64) to get consistent results as in PHP 5.5. $result = $this->za->statIndex($index, 64); if ($result === false) { return false; } $info = new stdClass(); $info->index = $index; $info->original_pathname = $result['name']; $info->pathname = $this->unmangle_pathname($result['name']); $info->mtime = (int)$result['mtime']; if ($info->pathname[strlen($info->pathname)-1] === '/') { $info->is_directory = true; $info->size = 0; } else { $info->is_directory = false; $info->size = (int)$result['size']; } if ($this->is_system_file($info)) { // Don't return system files. return false; } return $info; } /** * Returns array of info about all files in archive. * * @return array of file infos */ public function list_files() { if (!isset($this->za)) { return false; } $infos = array(); foreach ($this as $info) { // Simply iterating over $this will give us info only for files we're interested in. array_push($infos, $info); } return $infos; } public function is_system_file($fileinfo) { if (substr($fileinfo->pathname, 0, 8) === '__MACOSX' or substr($fileinfo->pathname, -9) === '.DS_Store') { // Mac OSX system files. return true; } if (substr($fileinfo->pathname, -9) === 'Thumbs.db') { $stream = $this->za->getStream($fileinfo->pathname); $info = base64_encode(fread($stream, 8)); fclose($stream); if ($info === '0M8R4KGxGuE=') { // It's an OLE Compound File - so it's almost certainly a Windows thumbnail cache. return true; } } return false; } /** * Returns number of files in archive. * * @return int number of files */ public function count() { if (!isset($this->za)) { return false; } return count($this->list_files()); } /** * Returns approximate number of files in archive. This may be a slight * overestimate. * * @return int|bool Estimated number of files, or false if not opened */ public function estimated_count() { if (!isset($this->za)) { return false; } return $this->za->numFiles; } /** * Add file into archive. * * @param string $localname name of file in archive * @param string $pathname location of file * @return bool success */ public function add_file_from_pathname($localname, $pathname) { if ($this->emptyziphack) { $this->close(); $this->open($this->archivepathname, file_archive::OVERWRITE, $this->encoding); } if (!isset($this->za)) { return false; } if ($this->archivepathname === realpath($pathname)) { // Do not add self into archive. return false; } if (!is_readable($pathname) or is_dir($pathname)) { return false; } if (is_null($localname)) { $localname = clean_param($pathname, PARAM_PATH); } $localname = trim($localname, '/'); // No leading slashes in archives! $localname = $this->mangle_pathname($localname); if ($localname === '') { // Sorry - conversion failed badly. return false; } if (!$this->za->addFile($pathname, $localname)) { return false; } $this->modified = true; return true; } /** * Add content of string into archive. * * @param string $localname name of file in archive * @param string $contents contents * @return bool success */ public function add_file_from_string($localname, $contents) { if ($this->emptyziphack) { $this->close(); $this->open($this->archivepathname, file_archive::OVERWRITE, $this->encoding); } if (!isset($this->za)) { return false; } $localname = trim($localname, '/'); // No leading slashes in archives! $localname = $this->mangle_pathname($localname); if ($localname === '') { // Sorry - conversion failed badly. return false; } if ($this->usedmem > 2097151) { // This prevents running out of memory when adding many large files using strings. $this->close(); $res = $this->open($this->archivepathname, file_archive::OPEN, $this->encoding); if ($res !== true) { print_error('cannotopenzip'); } } $this->usedmem += strlen($contents); if (!$this->za->addFromString($localname, $contents)) { return false; } $this->modified = true; return true; } /** * Add empty directory into archive. * * @param string $localname name of file in archive * @return bool success */ public function add_directory($localname) { if ($this->emptyziphack) { $this->close(); $this->open($this->archivepathname, file_archive::OVERWRITE, $this->encoding); } if (!isset($this->za)) { return false; } $localname = trim($localname, '/'). '/'; $localname = $this->mangle_pathname($localname); if ($localname === '/') { // Sorry - conversion failed badly. return false; } if ($localname !== '') { if (!$this->za->addEmptyDir($localname)) { return false; } $this->modified = true; } return true; } /** * Returns current file info. * * @return stdClass */ public function current() { if (!isset($this->za)) { return false; } return $this->get_info($this->pos); } /** * Returns the index of current file. * * @return int current file index */ public function key() { return $this->pos; } /** * Moves forward to next file. */ public function next() { $this->pos++; } /** * Rewinds back to the first file. */ public function rewind() { $this->pos = 0; } /** * Did we reach the end? * * @return bool */ public function valid() { if (!isset($this->za)) { return false; } // Skip over unwanted system files (get_info will return false). while (!$this->get_info($this->pos) && $this->pos < $this->za->numFiles) { $this->next(); } // No files left - we're at the end. if ($this->pos >= $this->za->numFiles) { return false; } return true; } /** * Create a map of file names used in zip archive. * @return void */ protected function init_namelookup() { if ($this->emptyziphack) { $this->namelookup = array(); return; } if (!isset($this->za)) { return; } if (isset($this->namelookup)) { return; } $this->namelookup = array(); if ($this->mode != file_archive::OPEN) { // No need to tweak existing names when creating zip file because there are none yet! return; } if (!file_exists($this->archivepathname)) { return; } if (!$fp = fopen($this->archivepathname, 'rb')) { return; } if (!$filesize = filesize($this->archivepathname)) { return; } $centralend = self::zip_get_central_end($fp, $filesize); if ($centralend === false or $centralend['disk'] !== 0 or $centralend['disk_start'] !== 0 or $centralend['offset'] === 0xFFFFFFFF) { // Single disk archives only and o support for ZIP64, sorry. fclose($fp); return; } fseek($fp, $centralend['offset']); $data = fread($fp, $centralend['size']); $pos = 0; $files = array(); for($i=0; $i<$centralend['entries']; $i++) { $file = self::zip_parse_file_header($data, $centralend, $pos); if ($file === false) { // Wrong header, sorry. fclose($fp); return; } $files[] = $file; } fclose($fp); foreach ($files as $file) { $name = $file['name']; if (preg_match('/^[a-zA-Z0-9_\-\.]*$/', $file['name'])) { // No need to fix ASCII. $name = fix_utf8($name); } else if (!($file['general'] & pow(2, 11))) { // First look for unicode name alternatives. $found = false; foreach($file['extra'] as $extra) { if ($extra['id'] === 0x7075) { $data = unpack('cversion/Vcrc', substr($extra['data'], 0, 5)); if ($data['crc'] === crc32($name)) { $found = true; $name = substr($extra['data'], 5); } } } if (!$found and !empty($this->encoding) and $this->encoding !== 'utf-8') { // Try the encoding from open(). $newname = @core_text::convert($name, $this->encoding, 'utf-8'); $original = core_text::convert($newname, 'utf-8', $this->encoding); if ($original === $name) { $found = true; $name = $newname; } } if (!$found and $file['version'] === 0x315) { // This looks like OS X build in zipper. $newname = fix_utf8($name); if ($newname === $name) { $found = true; $name = $newname; } } if (!$found and $file['version'] === 0) { // This looks like our old borked Moodle 2.2 file. $newname = fix_utf8($name); if ($newname === $name) { $found = true; $name = $newname; } } if (!$found and $encoding = get_string('oldcharset', 'langconfig')) { // Last attempt - try the dos/unix encoding from current language. $windows = true; foreach($file['extra'] as $extra) { // In Windows archivers do not usually set any extras with the exception of NTFS flag in WinZip/WinRar. $windows = false; if ($extra['id'] === 0x000a) { $windows = true; break; } } if ($windows === true) { switch(strtoupper($encoding)) { case 'ISO-8859-1': $encoding = 'CP850'; break; case 'ISO-8859-2': $encoding = 'CP852'; break; case 'ISO-8859-4': $encoding = 'CP775'; break; case 'ISO-8859-5': $encoding = 'CP866'; break; case 'ISO-8859-6': $encoding = 'CP720'; break; case 'ISO-8859-7': $encoding = 'CP737'; break; case 'ISO-8859-8': $encoding = 'CP862'; break; case 'WINDOWS-1251': $encoding = 'CP866'; break; case 'EUC-JP': case 'UTF-8': if ($winchar = get_string('localewincharset', 'langconfig')) { // Most probably works only for zh_cn, // if there are more problems we could add zipcharset to langconfig files. $encoding = $winchar; } break; } } $newname = @core_text::convert($name, $encoding, 'utf-8'); $original = core_text::convert($newname, 'utf-8', $encoding); if ($original === $name) { $name = $newname; } } } $name = str_replace('\\', '/', $name); // no MS \ separators $name = clean_param($name, PARAM_PATH); // only safe chars $name = ltrim($name, '/'); // no leading slash if (function_exists('normalizer_normalize')) { $name = normalizer_normalize($name, Normalizer::FORM_C); } $this->namelookup[$file['name']] = $name; } } /** * Add unicode flag to all files in archive. * * NOTE: single disk archives only, no ZIP64 support. * * @return bool success, modifies the file contents */ protected function fix_utf8_flags() { if ($this->emptyziphack) { return true; } if (!file_exists($this->archivepathname)) { return true; } // Note: the ZIP structure is described at http://www.pkware.com/documents/casestudies/APPNOTE.TXT if (!$fp = fopen($this->archivepathname, 'rb+')) { return false; } if (!$filesize = filesize($this->archivepathname)) { return false; } $centralend = self::zip_get_central_end($fp, $filesize); if ($centralend === false or $centralend['disk'] !== 0 or $centralend['disk_start'] !== 0 or $centralend['offset'] === 0xFFFFFFFF) { // Single disk archives only and o support for ZIP64, sorry. fclose($fp); return false; } fseek($fp, $centralend['offset']); $data = fread($fp, $centralend['size']); $pos = 0; $files = array(); for($i=0; $i<$centralend['entries']; $i++) { $file = self::zip_parse_file_header($data, $centralend, $pos); if ($file === false) { // Wrong header, sorry. fclose($fp); return false; } $newgeneral = $file['general'] | pow(2, 11); if ($newgeneral === $file['general']) { // Nothing to do with this file. continue; } if (preg_match('/^[a-zA-Z0-9_\-\.]*$/', $file['name'])) { // ASCII file names are always ok. continue; } if ($file['extra']) { // Most probably not created by php zip ext, better to skip it. continue; } if (fix_utf8($file['name']) !== $file['name']) { // Does not look like a valid utf-8 encoded file name, skip it. continue; } // Read local file header. fseek($fp, $file['local_offset']); $localfile = unpack('Vsig/vversion_req/vgeneral/vmethod/vmtime/vmdate/Vcrc/Vsize_compressed/Vsize/vname_length/vextra_length', fread($fp, 30)); if ($localfile['sig'] !== 0x04034b50) { // Borked file! fclose($fp); return false; } $file['local'] = $localfile; $files[] = $file; } foreach ($files as $file) { $localfile = $file['local']; // Add the unicode flag in central file header. fseek($fp, $file['central_offset'] + 8); if (ftell($fp) === $file['central_offset'] + 8) { $newgeneral = $file['general'] | pow(2, 11); fwrite($fp, pack('v', $newgeneral)); } // Modify local file header too. fseek($fp, $file['local_offset'] + 6); if (ftell($fp) === $file['local_offset'] + 6) { $newgeneral = $localfile['general'] | pow(2, 11); fwrite($fp, pack('v', $newgeneral)); } } fclose($fp); return true; } /** * Read end of central signature of ZIP file. * @internal * @static * @param resource $fp * @param int $filesize * @return array|bool */ public static function zip_get_central_end($fp, $filesize) { // Find end of central directory record. fseek($fp, $filesize - 22); $info = unpack('Vsig', fread($fp, 4)); if ($info['sig'] === 0x06054b50) { // There is no comment. fseek($fp, $filesize - 22); $data = fread($fp, 22); } else { // There is some comment with 0xFF max size - that is 65557. fseek($fp, $filesize - 65557); $data = fread($fp, 65557); } $pos = strpos($data, pack('V', 0x06054b50)); if ($pos === false) { // Borked ZIP structure! return false; } $centralend = unpack('Vsig/vdisk/vdisk_start/vdisk_entries/ventries/Vsize/Voffset/vcomment_length', substr($data, $pos, 22)); if ($centralend['comment_length']) { $centralend['comment'] = substr($data, 22, $centralend['comment_length']); } else { $centralend['comment'] = ''; } return $centralend; } /** * Parse file header. * @internal * @param string $data * @param array $centralend * @param int $pos (modified) * @return array|bool file info */ public static function zip_parse_file_header($data, $centralend, &$pos) { $file = unpack('Vsig/vversion/vversion_req/vgeneral/vmethod/Vmodified/Vcrc/Vsize_compressed/Vsize/vname_length/vextra_length/vcomment_length/vdisk/vattr/Vattrext/Vlocal_offset', substr($data, $pos, 46)); $file['central_offset'] = $centralend['offset'] + $pos; $pos = $pos + 46; if ($file['sig'] !== 0x02014b50) { // Borked ZIP structure! return false; } $file['name'] = substr($data, $pos, $file['name_length']); $pos = $pos + $file['name_length']; $file['extra'] = array(); $file['extra_data'] = ''; if ($file['extra_length']) { $extradata = substr($data, $pos, $file['extra_length']); $file['extra_data'] = $extradata; while (strlen($extradata) > 4) { $extra = unpack('vid/vsize', substr($extradata, 0, 4)); $extra['data'] = substr($extradata, 4, $extra['size']); $extradata = substr($extradata, 4+$extra['size']); $file['extra'][] = $extra; } $pos = $pos + $file['extra_length']; } if ($file['comment_length']) { $pos = $pos + $file['comment_length']; $file['comment'] = substr($data, $pos, $file['comment_length']); } else { $file['comment'] = ''; } return $file; } }