CasperSecurity
<?php
declare(strict_types=1);
namespace ZipStream;
use Closure;
use DateTimeInterface;
use DeflateContext;
use RuntimeException;
use ZipStream\Exception\FileSizeIncorrectException;
use ZipStream\Exception\OverflowException;
use ZipStream\Exception\ResourceActionException;
use ZipStream\Exception\SimulationFileUnknownException;
use ZipStream\Exception\StreamNotReadableException;
use ZipStream\Exception\StreamNotSeekableException;
/**
* @internal
*/
class File
{
private const CHUNKED_READ_BLOCK_SIZE = 0x1000000;
private Version $version;
private int $compressedSize = 0;
private int $uncompressedSize = 0;
private int $crc = 0;
private int $generalPurposeBitFlag = 0;
private readonly string $fileName;
/**
* @var resource|null
*/
private $stream;
/**
* @param Closure $dataCallback
* @psalm-param Closure(): resource $dataCallback
*/
public function __construct(
string $fileName,
private readonly Closure $dataCallback,
private readonly OperationMode $operationMode,
private readonly int $startOffset,
private readonly CompressionMethod $compressionMethod,
private readonly string $comment,
private readonly DateTimeInterface $lastModificationDateTime,
private readonly int $deflateLevel,
private readonly ?int $maxSize,
private readonly ?int $exactSize,
private readonly bool $enableZip64,
private readonly bool $enableZeroHeader,
private readonly Closure $send,
private readonly Closure $recordSentBytes,
) {
$this->fileName = self::filterFilename($fileName);
$this->checkEncoding();
if ($this->enableZeroHeader) {
$this->generalPurposeBitFlag |= GeneralPurposeBitFlag::ZERO_HEADER;
}
$this->version = $this->compressionMethod === CompressionMethod::DEFLATE ? Version::DEFLATE : Version::STORE;
}
public function cloneSimulationExecution(): self
{
return new self(
$this->fileName,
$this->dataCallback,
OperationMode::NORMAL,
$this->startOffset,
$this->compressionMethod,
$this->comment,
$this->lastModificationDateTime,
$this->deflateLevel,
$this->maxSize,
$this->exactSize,
$this->enableZip64,
$this->enableZeroHeader,
$this->send,
$this->recordSentBytes,
);
}
public function process(): string
{
$forecastSize = $this->forecastSize();
if ($this->enableZeroHeader) {
// No calculation required
} elseif ($this->isSimulation() && $forecastSize !== null) {
$this->uncompressedSize = $forecastSize;
$this->compressedSize = $forecastSize;
} else {
$this->readStream(send: false);
if (rewind($this->unpackStream()) === false) {
throw new ResourceActionException('rewind', $this->unpackStream());
}
}
$this->addFileHeader();
$detectedSize = $forecastSize ?? ($this->compressedSize > 0 ? $this->compressedSize : null);
if (
$this->isSimulation() &&
$detectedSize !== null
) {
($this->recordSentBytes)($detectedSize);
} else {
$this->readStream(send: true);
}
$this->addFileFooter();
return $this->getCdrFile();
}
/**
* @return resource
*/
private function unpackStream()
{
if ($this->stream) {
return $this->stream;
}
if ($this->operationMode === OperationMode::SIMULATE_STRICT) {
throw new SimulationFileUnknownException();
}
$this->stream = ($this->dataCallback)();
if (!$this->enableZeroHeader && !stream_get_meta_data($this->stream)['seekable']) {
throw new StreamNotSeekableException();
}
if (!(
str_contains(stream_get_meta_data($this->stream)['mode'], 'r')
|| str_contains(stream_get_meta_data($this->stream)['mode'], 'w+')
|| str_contains(stream_get_meta_data($this->stream)['mode'], 'a+')
|| str_contains(stream_get_meta_data($this->stream)['mode'], 'x+')
|| str_contains(stream_get_meta_data($this->stream)['mode'], 'c+')
)) {
throw new StreamNotReadableException();
}
return $this->stream;
}
private function forecastSize(): ?int
{
if ($this->compressionMethod !== CompressionMethod::STORE) {
return null;
}
if ($this->exactSize !== null) {
return $this->exactSize;
}
$fstat = fstat($this->unpackStream());
if (!$fstat || !array_key_exists('size', $fstat) || $fstat['size'] < 1) {
return null;
}
if ($this->maxSize !== null && $this->maxSize < $fstat['size']) {
return $this->maxSize;
}
return $fstat['size'];
}
/**
* Create and send zip header for this file.
*/
private function addFileHeader(): void
{
$forceEnableZip64 = $this->enableZeroHeader && $this->enableZip64;
$footer = $this->buildZip64ExtraBlock($forceEnableZip64);
$zip64Enabled = $footer !== '';
if ($zip64Enabled) {
$this->version = Version::ZIP64;
}
if ($this->generalPurposeBitFlag & GeneralPurposeBitFlag::EFS) {
// Put the tricky entry to
// force Linux unzip to lookup EFS flag.
$footer .= Zs\ExtendedInformationExtraField::generate();
}
$data = LocalFileHeader::generate(
versionNeededToExtract: $this->version->value,
generalPurposeBitFlag: $this->generalPurposeBitFlag,
compressionMethod: $this->compressionMethod,
lastModificationDateTime: $this->lastModificationDateTime,
crc32UncompressedData: $this->crc,
compressedSize: $zip64Enabled
? 0xFFFFFFFF
: $this->compressedSize,
uncompressedSize: $zip64Enabled
? 0xFFFFFFFF
: $this->uncompressedSize,
fileName: $this->fileName,
extraField: $footer,
);
($this->send)($data);
}
/**
* Strip characters that are not legal in Windows filenames
* to prevent compatibility issues
*/
private static function filterFilename(
/**
* Unprocessed filename
*/
string $fileName
): string {
// strip leading slashes from file name
// (fixes bug in windows archive viewer)
$fileName = ltrim($fileName, '/');
return str_replace(['\\', ':', '*', '?', '"', '<', '>', '|'], '_', $fileName);
}
private function checkEncoding(): void
{
// Sets Bit 11: Language encoding flag (EFS). If this bit is set,
// the filename and comment fields for this file
// MUST be encoded using UTF-8. (see APPENDIX D)
if (mb_check_encoding($this->fileName, 'UTF-8') &&
mb_check_encoding($this->comment, 'UTF-8')) {
$this->generalPurposeBitFlag |= GeneralPurposeBitFlag::EFS;
}
}
private function buildZip64ExtraBlock(bool $force = false): string
{
$outputZip64ExtraBlock = false;
$originalSize = null;
if ($force || $this->uncompressedSize > 0xFFFFFFFF) {
$outputZip64ExtraBlock = true;
$originalSize = $this->uncompressedSize;
}
$compressedSize = null;
if ($force || $this->compressedSize > 0xFFFFFFFF) {
$outputZip64ExtraBlock = true;
$compressedSize = $this->compressedSize;
}
// If this file will start over 4GB limit in ZIP file,
// CDR record will have to use Zip64 extension to describe offset
// to keep consistency we use the same value here
$relativeHeaderOffset = null;
if ($this->startOffset > 0xFFFFFFFF) {
$outputZip64ExtraBlock = true;
$relativeHeaderOffset = $this->startOffset;
}
if (!$outputZip64ExtraBlock) {
return '';
}
if (!$this->enableZip64) {
throw new OverflowException();
}
return Zip64\ExtendedInformationExtraField::generate(
originalSize: $originalSize,
compressedSize: $compressedSize,
relativeHeaderOffset: $relativeHeaderOffset,
diskStartNumber: null,
);
}
private function addFileFooter(): void
{
if (($this->compressedSize > 0xFFFFFFFF || $this->uncompressedSize > 0xFFFFFFFF) && $this->version !== Version::ZIP64) {
throw new OverflowException();
}
if (!$this->enableZeroHeader) {
return;
}
if ($this->version === Version::ZIP64) {
$footer = Zip64\DataDescriptor::generate(
crc32UncompressedData: $this->crc,
compressedSize: $this->compressedSize,
uncompressedSize: $this->uncompressedSize,
);
} else {
$footer = DataDescriptor::generate(
crc32UncompressedData: $this->crc,
compressedSize: $this->compressedSize,
uncompressedSize: $this->uncompressedSize,
);
}
($this->send)($footer);
}
private function readStream(bool $send): void
{
$this->compressedSize = 0;
$this->uncompressedSize = 0;
$hash = hash_init('crc32b');
$deflate = $this->compressionInit();
while (
!feof($this->unpackStream()) &&
($this->maxSize === null || $this->uncompressedSize < $this->maxSize) &&
($this->exactSize === null || $this->uncompressedSize < $this->exactSize)
) {
$readLength = min(
($this->maxSize ?? PHP_INT_MAX) - $this->uncompressedSize,
($this->exactSize ?? PHP_INT_MAX) - $this->uncompressedSize,
self::CHUNKED_READ_BLOCK_SIZE
);
$data = fread($this->unpackStream(), $readLength);
hash_update($hash, $data);
$this->uncompressedSize += strlen($data);
if ($deflate) {
$data = deflate_add(
$deflate,
$data,
feof($this->unpackStream()) ? ZLIB_FINISH : ZLIB_NO_FLUSH
);
}
$this->compressedSize += strlen($data);
if ($send) {
($this->send)($data);
}
}
if ($this->exactSize !== null && $this->uncompressedSize !== $this->exactSize) {
throw new FileSizeIncorrectException(expectedSize: $this->exactSize, actualSize: $this->uncompressedSize);
}
$this->crc = hexdec(hash_final($hash));
}
private function compressionInit(): ?DeflateContext
{
switch ($this->compressionMethod) {
case CompressionMethod::STORE:
// Noting to do
return null;
case CompressionMethod::DEFLATE:
$deflateContext = deflate_init(
ZLIB_ENCODING_RAW,
['level' => $this->deflateLevel]
);
if (!$deflateContext) {
// @codeCoverageIgnoreStart
throw new RuntimeException("Can't initialize deflate context.");
// @codeCoverageIgnoreEnd
}
// False positive, resource is no longer returned from this function
return $deflateContext;
default:
// @codeCoverageIgnoreStart
throw new RuntimeException('Unsupported Compression Method ' . print_r($this->compressionMethod, true));
// @codeCoverageIgnoreEnd
}
}
private function getCdrFile(): string
{
$footer = $this->buildZip64ExtraBlock();
return CentralDirectoryFileHeader::generate(
versionMadeBy: ZipStream::ZIP_VERSION_MADE_BY,
versionNeededToExtract: $this->version->value,
generalPurposeBitFlag: $this->generalPurposeBitFlag,
compressionMethod: $this->compressionMethod,
lastModificationDateTime: $this->lastModificationDateTime,
crc32: $this->crc,
compressedSize: $this->compressedSize > 0xFFFFFFFF
? 0xFFFFFFFF
: $this->compressedSize,
uncompressedSize: $this->uncompressedSize > 0xFFFFFFFF
? 0xFFFFFFFF
: $this->uncompressedSize,
fileName: $this->fileName,
extraField: $footer,
fileComment: $this->comment,
diskNumberStart: 0,
internalFileAttributes: 0,
externalFileAttributes: 32,
relativeOffsetOfLocalHeader: $this->startOffset > 0xFFFFFFFF
? 0xFFFFFFFF
: $this->startOffset,
);
}
private function isSimulation(): bool
{
return $this->operationMode === OperationMode::SIMULATE_LAX || $this->operationMode === OperationMode::SIMULATE_STRICT;
}
}