<?php
namespace PhpZip\Model\Extra\Fields;
use PhpZip\Exception\ZipException;
use PhpZip\Model\Extra\ZipExtraField;
use PhpZip\Model\ZipEntry;
/**
* Info-ZIP New Unix Extra Field:
* ====================================.
*
* Currently stores Unix UIDs/GIDs up to 32 bits.
* (Last Revision 20080509)
*
* Value Size Description
* ----- ---- -----------
* (UnixN) 0x7875 Short tag for this extra block type ("ux")
* TSize Short total data size for this block
* Version 1 byte version of this extra field, currently 1
* UIDSize 1 byte Size of UID field
* UID Variable UID for this entry
* GIDSize 1 byte Size of GID field
* GID Variable GID for this entry
*
* Currently Version is set to the number 1. If there is a need
* to change this field, the version will be incremented. Changes
* may not be backward compatible so this extra field should not be
* used if the version is not recognized.
*
* UIDSize is the size of the UID field in bytes. This size should
* match the size of the UID field on the target OS.
*
* UID is the UID for this entry in standard little endian format.
*
* GIDSize is the size of the GID field in bytes. This size should
* match the size of the GID field on the target OS.
*
* GID is the GID for this entry in standard little endian format.
*
* If both the old 16-bit Unix extra field (tag 0x7855, Info-ZIP Unix)
* and this extra field are present, the values in this extra field
* supercede the values in that extra field.
*/
class NewUnixExtraField implements ZipExtraField
{
/** @var int header id */
const HEADER_ID = 0x7875;
/** ID of the first non-root user created on a unix system. */
const USER_GID_PID = 1000;
/** @var int version of this extra field, currently 1 */
private $version = 1;
/** @var int User id */
private $uid;
/** @var int Group id */
private $gid;
/**
* NewUnixExtraField constructor.
*
* @param int $version
* @param int $uid
* @param int $gid
*/
public function __construct($version = 1, $uid = self::USER_GID_PID, $gid = self::USER_GID_PID)
{
$this->version = (int) $version;
$this->uid = (int) $uid;
$this->gid = (int) $gid;
}
/**
* Returns the Header ID (type) of this Extra Field.
* The Header ID is an unsigned short integer (two bytes)
* which must be constant during the life cycle of this object.
*
* @return int
*/
public function getHeaderId()
{
return self::HEADER_ID;
}
/**
* Populate data from this array as if it was in local file data.
*
* @param string $buffer the buffer to read data from
* @param ZipEntry|null $entry
*
* @throws ZipException
*
* @return NewUnixExtraField
*/
public static function unpackLocalFileData($buffer, ZipEntry $entry = null)
{
$length = \strlen($buffer);
if ($length < 3) {
throw new ZipException(sprintf('X7875_NewUnix length is too short, only %s bytes', $length));
}
$offset = 0;
$data = unpack('Cversion/CuidSize', $buffer);
$offset += 2;
$uidSize = $data['uidSize'];
$gid = self::readSizeIntegerLE(substr($buffer, $offset, $uidSize), $uidSize);
$offset += $uidSize;
$gidSize = unpack('C', $buffer[$offset])[1];
$offset++;
$uid = self::readSizeIntegerLE(substr($buffer, $offset, $gidSize), $gidSize);
return new self($data['version'], $gid, $uid);
}
/**
* Populate data from this array as if it was in central directory data.
*
* @param string $buffer the buffer to read data from
* @param ZipEntry|null $entry
*
* @throws ZipException
*
* @return NewUnixExtraField
*/
public static function unpackCentralDirData($buffer, ZipEntry $entry = null)
{
return self::unpackLocalFileData($buffer, $entry);
}
/**
* The actual data to put into local file data - without Header-ID
* or length specifier.
*
* @return string the data
*/
public function packLocalFileData()
{
return pack(
'CCVCV',
$this->version,
4, // UIDSize
$this->uid,
4, // GIDSize
$this->gid
);
}
/**
* The actual data to put into central directory - without Header-ID or
* length specifier.
*
* @return string the data
*/
public function packCentralDirData()
{
return $this->packLocalFileData();
}
/**
* @param string $data
* @param int $size
*
* @throws ZipException
*
* @return int
*/
private static function readSizeIntegerLE($data, $size)
{
$format = [
1 => 'C', // unsigned byte
2 => 'v', // unsigned short LE
4 => 'V', // unsigned int LE
];
if (!isset($format[$size])) {
throw new ZipException(sprintf('Invalid size bytes: %d', $size));
}
return unpack($format[$size], $data)[1];
}
/**
* @return int
*/
public function getUid()
{
return $this->uid;
}
/**
* @param int $uid
*/
public function setUid($uid)
{
$this->uid = $uid & 0xffffffff;
}
/**
* @return int
*/
public function getGid()
{
return $this->gid;
}
/**
* @param int $gid
*/
public function setGid($gid)
{
$this->gid = $gid & 0xffffffff;
}
/**
* @return int
*/
public function getVersion()
{
return $this->version;
}
/**
* @return string
*/
public function __toString()
{
return sprintf(
'0x%04x NewUnix: UID=%d GID=%d',
self::HEADER_ID,
$this->uid,
$this->gid
);
}
}