Support data descriptors in Zip

diff --git a/wcfsetup/install/files/lib/system/io/Zip.class.php b/wcfsetup/install/files/lib/system/io/Zip.class.php
index d0fb3c4beab0e663b5fc9878e92f376719650213..094f37cde2568b01921fd1d41c4fa0ce4c67eb5e 100644 (file)
--- a/wcfsetup/install/files/lib/system/io/Zip.class.php
+++ b/wcfsetup/install/files/lib/system/io/Zip.class.php
@@ -17,22 +17,23 @@ class Zip extends File implements IArchive {
        const LOCAL_FILE_SIGNATURE = "\x50\x4b\x03\x04";
        const CENTRAL_DIRECTORY_SIGNATURE = "\x50\x4b\x01\x02";
        const EOF_SIGNATURE = "\x50\x4b\x05\x06";
+       const DATA_DESCRIPTOR_SIGNATURE = "\x50\x4b\x07\x08";
+       protected $centralDirectory = null;
        
        /**
         * @see \wcf\system\io\File::__construct()
         */
        public function __construct($filename) {
                parent::__construct($filename, 'rb');
+               
+               $this->centralDirectory = $this->readCentralDirectory();
        }
        
        /**
         * @see \wcf\system\io\IArchive::getIndexByFilename()
         */
        public function getIndexByFilename($filename) {
-               $this->jumpToCentralDirectory();
-               $centralDirectory = $this->readCentralDirectory();
-               
-               if (isset($centralDirectory['files'][$filename])) return $centralDirectory['files'][$filename]['offset'];
+               if (isset($this->centralDirectory['files'][$filename])) return $this->centralDirectory['files'][$filename]['offset'];
                return false;
        }
        
@@ -40,10 +41,7 @@ class Zip extends File implements IArchive {
         * @see \wcf\system\io\IArchive::getContentList()
         */
        public function getContentList() {
-               $this->jumpToCentralDirectory();
-               $centralDirectory = $this->readCentralDirectory();
-               
-               return $centralDirectory['files'];
+               return $this->centralDirectory['files'];
        }
        
        /**
@@ -131,7 +129,7 @@ class Zip extends File implements IArchive {
        /**
         * Moves the file-pointer to the beginning of the Central Directory.
         */
-       public function jumpToCentralDirectory() {
+       protected function jumpToCentralDirectory() {
                $this->seek(0, SEEK_END);
                $lastOffset = $this->tell();
                $this->seek(-4, SEEK_CUR);
@@ -159,19 +157,18 @@ class Zip extends File implements IArchive {
        /**
         * Reads the central directory and returns it.
         * 
-        * @param       integer         $offset         where to start reading
         * @return      array
         */
-       public function readCentralDirectory($offset = null) {
-               if ($offset === null) $offset = $this->tell();
-               if ($offset === false) throw new SystemException('Invalid offset passed to readCentralDirectory');
+       protected function readCentralDirectory() {
+               $this->jumpToCentralDirectory();
                
-               $this->seek($offset);
+               $offset = $this->tell();
+
                // check signature
                if ($this->read(4) !== self::CENTRAL_DIRECTORY_SIGNATURE) {
-                       throw new SystemException('Invalid offset passed to readCentralDirectory');
+                       throw new SystemException('Not in central directory');
                }
-               $this->seek($offset);
+               $this->seek(-4, SEEK_CUR);
                
                $files = array();
                while ($this->read(4) === self::CENTRAL_DIRECTORY_SIGNATURE) {
@@ -200,7 +197,7 @@ class Zip extends File implements IArchive {
                        
                        $files[$data['filename']] = $data;
                }
-               $this->seek($this->tell() - 4);
+               $this->seek(-4, SEEK_CUR);
                $size = $this->tell() - $offset;
                
                if ($this->read(4) !== self::EOF_SIGNATURE) throw new SystemException('Could not find the end of Central Directory');
@@ -237,35 +234,6 @@ class Zip extends File implements IArchive {
                return $result;
        }
        
-       /**
-        * Moves the file-pointer right after this file.
-        * 
-        * @param       integer         $offset         where to start reading
-        */
-       public function skipFile($offset = null) {
-               if ($offset === null) $offset = $this->tell();
-               if (!is_int($offset)) $offset = $this->getIndexByFilename($offset);
-               if ($offset === false) throw new SystemException('Invalid offset passed to skipFile');
-               
-               $this->seek($offset);
-               // check signature
-               if ($this->read(4) !== self::LOCAL_FILE_SIGNATURE) {
-                       throw new SystemException('Invalid offset passed to skipFile');
-               }
-               
-               // skip unneccessary header
-               $this->seek($offset + 18);
-               // read compressed filesize
-               $compressedSize = $this->readAndUnpack(4, 'V');
-               $this->read(4);
-               // read length of some fields
-               $filenameLength = $this->readAndUnpack(2, 'v');
-               $extraFieldLength = $this->readAndUnpack(2, 'v');
-               
-               // skip file
-               $this->seek($offset + 30 + $compressedSize + $filenameLength + $extraFieldLength);
-       }
-       
        /**
         * Reads a file and returns it.
         * 
@@ -286,7 +254,6 @@ class Zip extends File implements IArchive {
                // read headers
                $header = array();
                $header = unpack('vminVersion/vgeneralPurposeBit/vcompression/vmtime/vmdate', $this->read(10));
-               if ($header['generalPurposeBit'] & 7 /* 3rd bit */) throw new SystemException('Data Descriptors are not supported');
                $second = ($header['mtime'] & 31 /* 5 bits */) * 2;
                $minute = ($header['mtime'] >> 5) & 63 /* 6 bits */;
                $hour = ($header['mtime'] >> 11) & 31 /* 5 bits */;
@@ -302,6 +269,13 @@ class Zip extends File implements IArchive {
                if ($header['extraFieldLength'] > 0) $header['extraField'] = $this->read($header['extraFieldLength']);
                else $header['extraField'] = '';
                
+               // fetch sizes and crc from central directory
+               if ($header['generalPurposeBit'] & (1 << 3)) {
+                       $header['compressedSize'] = $this->centralDirectory['files'][$header['filename']]['compressedSize'];
+                       $header['size'] = $this->centralDirectory['files'][$header['filename']]['size'];
+                       $header['crc32'] = $this->centralDirectory['files'][$header['filename']]['crc32'];
+               }
+
                // read contents
                $header['type'] = 'file';
                if (substr($header['filename'], -1) != '/') $content = $this->read($header['compressedSize']);
@@ -327,6 +301,16 @@ class Zip extends File implements IArchive {
                // check crc32
                if (crc32($content) != $header['crc32']) throw new SystemException('Checksum does not match');
                
+               // gobble data descriptor
+               if ($header['generalPurposeBit'] & (1 << 3)) {
+                       if ($this->read(4) === self::DATA_DESCRIPTOR_SIGNATURE) {
+                               $this->read(12);
+                       }
+                       else {
+                               $this->read(8);
+                       }
+               }
+               
                return array('header' => $header, 'content' => $content);
        }