libraries/ZipFile.php

   1 <?php
   2 /* vim: set expandtab sw=4 ts=4 sts=4: */
   3 /**
   4  * Zip file creation
   5  *
   6  * @package PhpMyAdmin
   7  */
   8 namespace PMA\libraries;
   9
  10 if (!defined('PHPMYADMIN')) {
  11     exit;
  12 }
  13
  14 /**
  15  * Zip file creation class.
  16  * Makes zip files.
  17  *
  18  * @access  public
  19  * @package PhpMyAdmin
  20  * @see     Official ZIP file format: https://www.pkware.com/support/zip-app-note
  21  */
  22 class ZipFile
  23 {
  24     /**
  25      * Whether to echo zip as it's built or return as string from -> file
  26      *
  27      * @var  boolean $doWrite
  28      */
  29     var $doWrite = false;
  30     /**
  31      * Array to store compressed data
  32      *
  33      * @var  array $datasec
  34      */
  35     var $datasec = array();
  36     /**
  37      * Central directory
  38      *
  39      * @var  array $ctrl_dir
  40      */
  41     var $ctrl_dir = array();
  42     /**
  43      * End of central directory record
  44      *
  45      * @var  string $eof_ctrl_dir
  46      */
  47     var $eof_ctrl_dir = "\x50\x4b\x05\x06\x00\x00\x00\x00";
  48     /**
  49      * Last offset position
  50      *
  51      * @var  integer $old_offset
  52      */
  53     var $old_offset = 0;
  54
  55     /**
  56      * Sets member variable this -> doWrite to true
  57      * - Should be called immediately after class instantiation
  58      * - If set to true, then ZIP archive are echo'ed to STDOUT as each
  59      *   file is added via this -> addfile(), and central directories are
  60      *   echoed to STDOUT on final call to this -> file().  Also,
  61      *   this -> file() returns an empty string so it is safe to issue a
  62      *   "echo $zipfile;" command
  63      *
  64      * @access public
  65      *
  66      * @return void
  67      */
  68     function setDoWrite()
  69     {
  70         $this->doWrite = true;
  71     } // end of the 'setDoWrite()' method
  72
  73     /**
  74      * Converts an Unix timestamp to a four byte DOS date and time format (date
  75      * in high two bytes, time in low two bytes allowing magnitude comparison).
  76      *
  77      * @param integer $unixtime the current Unix timestamp
  78      *
  79      * @return integer the current date in a four byte DOS format
  80      *
  81      * @access private
  82      */
  83     function unix2DosTime($unixtime = 0)
  84     {
  85         $timearray = ($unixtime == 0) ? getdate() : getdate($unixtime);
  86
  87         if ($timearray['year'] < 1980) {
  88             $timearray['year'] = 1980;
  89             $timearray['mon'] = 1;
  90             $timearray['mday'] = 1;
  91             $timearray['hours'] = 0;
  92             $timearray['minutes'] = 0;
  93             $timearray['seconds'] = 0;
  94         } // end if
  95
  96         return (($timearray['year'] - 1980) << 25)
  97         | ($timearray['mon'] << 21)
  98         | ($timearray['mday'] << 16)
  99         | ($timearray['hours'] << 11)
 100         | ($timearray['minutes'] << 5)
 101         | ($timearray['seconds'] >> 1);
 102     } // end of the 'unix2DosTime()' method
 103
 104     /**
 105      * Adds "file" to archive
 106      *
 107      * @param string  $data file contents
 108      * @param string  $name name of the file in the archive (may contains the path)
 109      * @param integer $time the current timestamp
 110      *
 111      * @access public
 112      *
 113      * @return void
 114      */
 115     function addFile($data, $name, $time = 0)
 116     {
 117         $name = str_replace('\\', '/', $name);
 118
 119         $hexdtime = pack('V', $this->unix2DosTime($time));
 120
 121         $fr = "\x50\x4b\x03\x04";
 122         $fr .= "\x14\x00";            // ver needed to extract
 123         $fr .= "\x00\x00";            // gen purpose bit flag
 124         $fr .= "\x08\x00";            // compression method
 125         $fr .= $hexdtime;             // last mod time and date
 126
 127         // "local file header" segment
 128         $unc_len = strlen($data);
 129         $crc = crc32($data);
 130         $zdata = gzcompress($data);
 131         $zdata = substr(substr($zdata, 0, strlen($zdata) - 4), 2); // fix crc bug
 132         $c_len = strlen($zdata);
 133         $fr .= pack('V', $crc);             // crc32
 134         $fr .= pack('V', $c_len);           // compressed filesize
 135         $fr .= pack('V', $unc_len);         // uncompressed filesize
 136         $fr .= pack('v', strlen($name));    // length of filename
 137         $fr .= pack('v', 0);                // extra field length
 138         $fr .= $name;
 139
 140         // "file data" segment
 141         $fr .= $zdata;
 142
 143         // echo this entry on the fly, ...
 144         if ($this->doWrite) {
 145             echo $fr;
 146         } else {                     // ... OR add this entry to array
 147             $this->datasec[] = $fr;
 148         }
 149
 150         // now add to central directory record
 151         $cdrec = "\x50\x4b\x01\x02";
 152         $cdrec .= "\x00\x00";                // version made by
 153         $cdrec .= "\x14\x00";                // version needed to extract
 154         $cdrec .= "\x00\x00";                // gen purpose bit flag
 155         $cdrec .= "\x08\x00";                // compression method
 156         $cdrec .= $hexdtime;                 // last mod time & date
 157         $cdrec .= pack('V', $crc);           // crc32
 158         $cdrec .= pack('V', $c_len);         // compressed filesize
 159         $cdrec .= pack('V', $unc_len);       // uncompressed filesize
 160         $cdrec .= pack('v', strlen($name)); // length of filename
 161         $cdrec .= pack('v', 0);             // extra field length
 162         $cdrec .= pack('v', 0);             // file comment length
 163         $cdrec .= pack('v', 0);             // disk number start
 164         $cdrec .= pack('v', 0);             // internal file attributes
 165         $cdrec .= pack('V', 32);            // external file attributes
 166         // - 'archive' bit set
 167
 168         $cdrec .= pack('V', $this->old_offset); // relative offset of local header
 169         $this->old_offset += strlen($fr);
 170
 171         $cdrec .= $name;
 172
 173         // optional extra field, file comment goes here
 174         // save to central directory
 175         $this->ctrl_dir[] = $cdrec;
 176     } // end of the 'addFile()' method
 177
 178     /**
 179      * Echo central dir if ->doWrite==true, else build string to return
 180      *
 181      * @return string  if ->doWrite {empty string} else the ZIP file contents
 182      *
 183      * @access public
 184      */
 185     function file()
 186     {
 187         $ctrldir = implode('', $this->ctrl_dir);
 188         $header = $ctrldir .
 189             $this->eof_ctrl_dir .
 190             pack('v', sizeof($this->ctrl_dir)) . //total #of entries "on this disk"
 191             pack('v', sizeof($this->ctrl_dir)) . //total #of entries overall
 192             pack('V', strlen($ctrldir)) .          //size of central dir
 193             pack('V', $this->old_offset) .       //offset to start of central dir
 194             "\x00\x00";                            //.zip file comment length
 195
 196         if ($this->doWrite) { // Send central directory & end ctrl dir to STDOUT
 197             echo $header;
 198
 199             return "";            // Return empty string
 200         } else {                  // Return entire ZIP archive as string
 201             $data = implode('', $this->datasec);
 202
 203             return $data . $header;
 204         }
 205     } // end of the 'file()' method
 206 } // end of the 'PMA\libraries\ZipFile' class