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<?php
namespace PhpOffice\PhpSpreadsheet\Shared;
use PhpOffice\PhpSpreadsheet\Reader\Exception as ReaderException;
class OLERead
{
private $data = '';
// Size of a sector = 512 bytes
const BIG_BLOCK_SIZE = 0x200;
// Size of a short sector = 64 bytes
const SMALL_BLOCK_SIZE = 0x40;
// Size of a directory entry always = 128 bytes
const PROPERTY_STORAGE_BLOCK_SIZE = 0x80;
// Minimum size of a standard stream = 4096 bytes, streams smaller than this are stored as short streams
const SMALL_BLOCK_THRESHOLD = 0x1000;
// header offsets
const NUM_BIG_BLOCK_DEPOT_BLOCKS_POS = 0x2c;
const ROOT_START_BLOCK_POS = 0x30;
const SMALL_BLOCK_DEPOT_BLOCK_POS = 0x3c;
const EXTENSION_BLOCK_POS = 0x44;
const NUM_EXTENSION_BLOCK_POS = 0x48;
const BIG_BLOCK_DEPOT_BLOCKS_POS = 0x4c;
// property storage offsets (directory offsets)
const SIZE_OF_NAME_POS = 0x40;
const TYPE_POS = 0x42;
const START_BLOCK_POS = 0x74;
const SIZE_POS = 0x78;
public $wrkbook;
public $summaryInformation;
public $documentSummaryInformation;
/**
* @var int
*/
private $numBigBlockDepotBlocks;
/**
* @var int
*/
private $rootStartBlock;
/**
* @var int
*/
private $sbdStartBlock;
/**
* @var int
*/
private $extensionBlock;
/**
* @var int
*/
private $numExtensionBlocks;
/**
* @var string
*/
private $bigBlockChain;
/**
* @var string
*/
private $smallBlockChain;
/**
* @var string
*/
private $entry;
/**
* @var int
*/
private $rootentry;
/**
* @var array
*/
private $props = [];
/**
* Read the file.
*
* @param $pFilename string Filename
*/
public function read($pFilename): void
{
File::assertFile($pFilename);
// Get the file identifier
// Don't bother reading the whole file until we know it's a valid OLE file
$this->data = file_get_contents($pFilename, false, null, 0, 8);
// Check OLE identifier
$identifierOle = pack('CCCCCCCC', 0xd0, 0xcf, 0x11, 0xe0, 0xa1, 0xb1, 0x1a, 0xe1);
if ($this->data != $identifierOle) {
throw new ReaderException('The filename ' . $pFilename . ' is not recognised as an OLE file');
}
// Get the file data
$this->data = file_get_contents($pFilename);
// Total number of sectors used for the SAT
$this->numBigBlockDepotBlocks = self::getInt4d($this->data, self::NUM_BIG_BLOCK_DEPOT_BLOCKS_POS);
// SecID of the first sector of the directory stream
$this->rootStartBlock = self::getInt4d($this->data, self::ROOT_START_BLOCK_POS);
// SecID of the first sector of the SSAT (or -2 if not extant)
$this->sbdStartBlock = self::getInt4d($this->data, self::SMALL_BLOCK_DEPOT_BLOCK_POS);
// SecID of the first sector of the MSAT (or -2 if no additional sectors are used)
$this->extensionBlock = self::getInt4d($this->data, self::EXTENSION_BLOCK_POS);
// Total number of sectors used by MSAT
$this->numExtensionBlocks = self::getInt4d($this->data, self::NUM_EXTENSION_BLOCK_POS);
$bigBlockDepotBlocks = [];
$pos = self::BIG_BLOCK_DEPOT_BLOCKS_POS;
$bbdBlocks = $this->numBigBlockDepotBlocks;
if ($this->numExtensionBlocks != 0) {
$bbdBlocks = (self::BIG_BLOCK_SIZE - self::BIG_BLOCK_DEPOT_BLOCKS_POS) / 4;
}
for ($i = 0; $i < $bbdBlocks; ++$i) {
$bigBlockDepotBlocks[$i] = self::getInt4d($this->data, $pos);
$pos += 4;
}
for ($j = 0; $j < $this->numExtensionBlocks; ++$j) {
$pos = ($this->extensionBlock + 1) * self::BIG_BLOCK_SIZE;
$blocksToRead = min($this->numBigBlockDepotBlocks - $bbdBlocks, self::BIG_BLOCK_SIZE / 4 - 1);
for ($i = $bbdBlocks; $i < $bbdBlocks + $blocksToRead; ++$i) {
$bigBlockDepotBlocks[$i] = self::getInt4d($this->data, $pos);
$pos += 4;
}
$bbdBlocks += $blocksToRead;
if ($bbdBlocks < $this->numBigBlockDepotBlocks) {
$this->extensionBlock = self::getInt4d($this->data, $pos);
}
}
$pos = 0;
$this->bigBlockChain = '';
$bbs = self::BIG_BLOCK_SIZE / 4;
for ($i = 0; $i < $this->numBigBlockDepotBlocks; ++$i) {
$pos = ($bigBlockDepotBlocks[$i] + 1) * self::BIG_BLOCK_SIZE;
$this->bigBlockChain .= substr($this->data, $pos, 4 * $bbs);
$pos += 4 * $bbs;
}
$pos = 0;
$sbdBlock = $this->sbdStartBlock;
$this->smallBlockChain = '';
while ($sbdBlock != -2) {
$pos = ($sbdBlock + 1) * self::BIG_BLOCK_SIZE;
$this->smallBlockChain .= substr($this->data, $pos, 4 * $bbs);
$pos += 4 * $bbs;
$sbdBlock = self::getInt4d($this->bigBlockChain, $sbdBlock * 4);
}
// read the directory stream
$block = $this->rootStartBlock;
$this->entry = $this->readData($block);
$this->readPropertySets();
}
/**
* Extract binary stream data.
*
* @param int $stream
*
* @return string
*/
public function getStream($stream)
{
if ($stream === null) {
return null;
}
$streamData = '';
if ($this->props[$stream]['size'] < self::SMALL_BLOCK_THRESHOLD) {
$rootdata = $this->readData($this->props[$this->rootentry]['startBlock']);
$block = $this->props[$stream]['startBlock'];
while ($block != -2) {
$pos = $block * self::SMALL_BLOCK_SIZE;
$streamData .= substr($rootdata, $pos, self::SMALL_BLOCK_SIZE);
$block = self::getInt4d($this->smallBlockChain, $block * 4);
}
return $streamData;
}
$numBlocks = $this->props[$stream]['size'] / self::BIG_BLOCK_SIZE;
if ($this->props[$stream]['size'] % self::BIG_BLOCK_SIZE != 0) {
++$numBlocks;
}
if ($numBlocks == 0) {
return '';
}
$block = $this->props[$stream]['startBlock'];
while ($block != -2) {
$pos = ($block + 1) * self::BIG_BLOCK_SIZE;
$streamData .= substr($this->data, $pos, self::BIG_BLOCK_SIZE);
$block = self::getInt4d($this->bigBlockChain, $block * 4);
}
return $streamData;
}
/**
* Read a standard stream (by joining sectors using information from SAT).
*
* @param int $bl Sector ID where the stream starts
*
* @return string Data for standard stream
*/
private function readData($bl)
{
$block = $bl;
$data = '';
while ($block != -2) {
$pos = ($block + 1) * self::BIG_BLOCK_SIZE;
$data .= substr($this->data, $pos, self::BIG_BLOCK_SIZE);
$block = self::getInt4d($this->bigBlockChain, $block * 4);
}
return $data;
}
/**
* Read entries in the directory stream.
*/
private function readPropertySets(): void
{
$offset = 0;
// loop through entires, each entry is 128 bytes
$entryLen = strlen($this->entry);
while ($offset < $entryLen) {
// entry data (128 bytes)
$d = substr($this->entry, $offset, self::PROPERTY_STORAGE_BLOCK_SIZE);
// size in bytes of name
$nameSize = ord($d[self::SIZE_OF_NAME_POS]) | (ord($d[self::SIZE_OF_NAME_POS + 1]) << 8);
// type of entry
$type = ord($d[self::TYPE_POS]);
// sectorID of first sector or short sector, if this entry refers to a stream (the case with workbook)
// sectorID of first sector of the short-stream container stream, if this entry is root entry
$startBlock = self::getInt4d($d, self::START_BLOCK_POS);
$size = self::getInt4d($d, self::SIZE_POS);
$name = str_replace("\x00", '', substr($d, 0, $nameSize));
$this->props[] = [
'name' => $name,
'type' => $type,
'startBlock' => $startBlock,
'size' => $size,
];
// tmp helper to simplify checks
$upName = strtoupper($name);
// Workbook directory entry (BIFF5 uses Book, BIFF8 uses Workbook)
if (($upName === 'WORKBOOK') || ($upName === 'BOOK')) {
$this->wrkbook = count($this->props) - 1;
} elseif ($upName === 'ROOT ENTRY' || $upName === 'R') {
// Root entry
$this->rootentry = count($this->props) - 1;
}
// Summary information
if ($name == chr(5) . 'SummaryInformation') {
$this->summaryInformation = count($this->props) - 1;
}
// Additional Document Summary information
if ($name == chr(5) . 'DocumentSummaryInformation') {
$this->documentSummaryInformation = count($this->props) - 1;
}
$offset += self::PROPERTY_STORAGE_BLOCK_SIZE;
}
}
/**
* Read 4 bytes of data at specified position.
*
* @param string $data
* @param int $pos
*
* @return int
*/
private static function getInt4d($data, $pos)
{
if ($pos < 0) {
// Invalid position
throw new ReaderException('Parameter pos=' . $pos . ' is invalid.');
}
$len = strlen($data);
if ($len < $pos + 4) {
$data .= str_repeat("\0", $pos + 4 - $len);
}
// FIX: represent numbers correctly on 64-bit system
// http://sourceforge.net/tracker/index.php?func=detail&aid=1487372&group_id=99160&atid=623334
// Changed by Andreas Rehm 2006 to ensure correct result of the <<24 block on 32 and 64bit systems
$_or_24 = ord($data[$pos + 3]);
if ($_or_24 >= 128) {
// negative number
$_ord_24 = -abs((256 - $_or_24) << 24);
} else {
$_ord_24 = ($_or_24 & 127) << 24;
}
return ord($data[$pos]) | (ord($data[$pos + 1]) << 8) | (ord($data[$pos + 2]) << 16) | $_ord_24;
}
}
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