1 <?php
  2 /**
  3  * @package     Joomla.Platform
  4  * @subpackage  Archive
  5  *
  6  * @copyright   Copyright (C) 2005 - 2017 Open Source Matters, Inc. All rights reserved.
  7  * @license     GNU General Public License version 2 or later; see LICENSE
  8  */
  9 
 10 defined('JPATH_PLATFORM') or die;
 11 
 12 jimport('joomla.filesystem.file');
 13 
 14 /**
 15  * Gzip format adapter for the JArchive class
 16  *
 17  * This class is inspired from and draws heavily in code and concept from the Compress package of
 18  * The Horde Project <https://www.horde.org>
 19  *
 20  * @contributor  Michael Slusarz <slusarz@horde.org>
 21  * @contributor  Michael Cochrane <mike@graftonhall.co.nz>
 22  *
 23  * @since  11.1
 24  */
 25 class JArchiveGzip implements JArchiveExtractable
 26 {
 27     /**
 28      * Gzip file flags.
 29      *
 30      * @var    array
 31      * @since  11.1
 32      */
 33     private $_flags = array('FTEXT' => 0x01, 'FHCRC' => 0x02, 'FEXTRA' => 0x04, 'FNAME' => 0x08, 'FCOMMENT' => 0x10);
 34 
 35     /**
 36      * Gzip file data buffer
 37      *
 38      * @var    string
 39      * @since  11.1
 40      */
 41     private $_data = null;
 42 
 43     /**
 44      * Extract a Gzip compressed file to a given path
 45      *
 46      * @param   string  $archive      Path to ZIP archive to extract
 47      * @param   string  $destination  Path to extract archive to
 48      * @param   array   $options      Extraction options [unused]
 49      *
 50      * @return  boolean  True if successful
 51      *
 52      * @since   11.1
 53      * @throws  RuntimeException
 54      */
 55     public function extract($archive, $destination, array $options = array())
 56     {
 57         $this->_data = null;
 58 
 59         if (!extension_loaded('zlib'))
 60         {
 61             return $this->raiseWarning(100, 'The zlib extension is not available.');
 62         }
 63 
 64         if (isset($options['use_streams']) && $options['use_streams'] != false)
 65         {
 66             return $this->extractStream($archive, $destination, $options);
 67         }
 68 
 69         $this->_data = file_get_contents($archive);
 70 
 71         if (!$this->_data)
 72         {
 73             return $this->raiseWarning(100, 'Unable to read archive');
 74         }
 75 
 76         $position = $this->_getFilePosition();
 77         $buffer = gzinflate(substr($this->_data, $position, strlen($this->_data) - $position));
 78 
 79         if (empty($buffer))
 80         {
 81             return $this->raiseWarning(100, 'Unable to decompress data');
 82         }
 83 
 84         if (JFile::write($destination, $buffer) === false)
 85         {
 86             return $this->raiseWarning(100, 'Unable to write archive');
 87         }
 88 
 89         return true;
 90     }
 91 
 92     /**
 93      * Method to extract archive using stream objects
 94      *
 95      * @param   string  $archive      Path to ZIP archive to extract
 96      * @param   string  $destination  Path to extract archive to
 97      * @param   array   $options      Extraction options [unused]
 98      *
 99      * @return  boolean  True if successful
100      */
101     protected function extractStream($archive, $destination, $options = array())
102     {
103         // New style! streams!
104         $input = JFactory::getStream();
105 
106         // Use gz
107         $input->set('processingmethod', 'gz');
108 
109         if (!$input->open($archive))
110         {
111             return $this->raiseWarning(100, 'Unable to read archive (gz)');
112         }
113 
114         $output = JFactory::getStream();
115 
116         if (!$output->open($destination, 'w'))
117         {
118             $input->close();
119 
120             return $this->raiseWarning(100, 'Unable to write archive (gz)');
121         }
122 
123         do
124         {
125             $this->_data = $input->read($input->get('chunksize', 8196));
126 
127             if ($this->_data && !$output->write($this->_data))
128             {
129                 $input->close();
130 
131                 return $this->raiseWarning(100, 'Unable to write file (gz)');
132             }
133         }
134 
135         while ($this->_data);
136 
137         $output->close();
138         $input->close();
139 
140         return true;
141     }
142 
143     /**
144      * Temporary private method to isolate JError from the extract method
145      * This code should be removed when JError is removed.
146      *
147      * @param   int     $code  The application-internal error code for this error
148      * @param   string  $msg   The error message, which may also be shown the user if need be.
149      *
150      * @return  JException  JException instance if JError class exists
151      *
152      * @throws  RuntimeException if JError class does not exist
153      */
154     private function raiseWarning($code, $msg)
155     {
156         if (class_exists('JError'))
157         {
158             return JError::raiseWarning($code, $msg);
159         }
160 
161         throw new RuntimeException($msg);
162     }
163 
164     /**
165      * Tests whether this adapter can unpack files on this computer.
166      *
167      * @return  boolean  True if supported
168      *
169      * @since   11.3
170      */
171     public static function isSupported()
172     {
173         return extension_loaded('zlib');
174     }
175 
176     /**
177      * Get file data offset for archive
178      *
179      * @return  integer  Data position marker for archive
180      *
181      * @since   11.1
182      * @throws  RuntimeException
183      */
184     public function _getFilePosition()
185     {
186         // Gzipped file... unpack it first
187         $position = 0;
188         $info = @ unpack('CCM/CFLG/VTime/CXFL/COS', substr($this->_data, $position + 2));
189 
190         if (!$info)
191         {
192             return $this->raiseWarning(100, 'Unable to decompress data.');
193         }
194 
195         $position += 10;
196 
197         if ($info['FLG'] & $this->_flags['FEXTRA'])
198         {
199             $XLEN = unpack('vLength', substr($this->_data, $position + 0, 2));
200             $XLEN = $XLEN['Length'];
201             $position += $XLEN + 2;
202         }
203 
204         if ($info['FLG'] & $this->_flags['FNAME'])
205         {
206             $filenamePos = strpos($this->_data, "\x0", $position);
207             $position = $filenamePos + 1;
208         }
209 
210         if ($info['FLG'] & $this->_flags['FCOMMENT'])
211         {
212             $commentPos = strpos($this->_data, "\x0", $position);
213             $position = $commentPos + 1;
214         }
215 
216         if ($info['FLG'] & $this->_flags['FHCRC'])
217         {
218             $hcrc = unpack('vCRC', substr($this->_data, $position + 0, 2));
219             $hcrc = $hcrc['CRC'];
220             $position += 2;
221         }
222 
223         return $position;
224     }
225 }
226 

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