ObjFW  Artifact [a5dd4c3dce]

Artifact a5dd4c3dce8ef533c8280c98b11d32798cf8ee28e1bcba3272e5173a0ff44a6e:

• File src/OFZIPArchive.m — part of check-in [d1d36ae522] at 2021-11-06 15:57:29 on branch trunk — OFStream: New write API

  The old write API made it too easy to lose bytes when a stream is set to
  non-blocking mode. The new API always throws when not all bytes were
  written, which forces handling the number of bytes being written being
  smaller than the number of bytes requested to be written. (user: js, size: 23736) [annotate] [blame] [check-ins using]

/*
 * Copyright (c) 2008-2021 Jonathan Schleifer <js@nil.im>
 *
 * All rights reserved.
 *
 * This file is part of ObjFW. It may be distributed under the terms of the
 * Q Public License 1.0, which can be found in the file LICENSE.QPL included in
 * the packaging of this file.
 *
 * Alternatively, it may be distributed under the terms of the GNU General
 * Public License, either version 2 or 3, which can be found in the file
 * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
 * file.
 */

#include "config.h"

#include <errno.h>

#import "OFZIPArchive.h"
#import "OFZIPArchiveEntry.h"
#import "OFZIPArchiveEntry+Private.h"
#import "OFCRC32.h"
#import "OFData.h"
#import "OFArray.h"
#import "OFDictionary.h"
#import "OFStream.h"
#import "OFSeekableStream.h"
#ifdef OF_HAVE_FILES
# import "OFFile.h"
#endif
#import "OFInflateStream.h"
#import "OFInflate64Stream.h"

#import "OFChecksumMismatchException.h"
#import "OFInvalidArgumentException.h"
#import "OFInvalidFormatException.h"
#import "OFNotImplementedException.h"
#import "OFNotOpenException.h"
#import "OFOpenItemFailedException.h"
#import "OFOutOfRangeException.h"
#import "OFSeekFailedException.h"
#import "OFTruncatedDataException.h"
#import "OFUnsupportedVersionException.h"
#import "OFWriteFailedException.h"

/*
 * FIXME: Current limitations:
 *  - Split archives are not supported.
 *  - Encrypted files cannot be read.
 */

enum {
	modeRead,
	modeWrite,
	modeAppend
};

OF_DIRECT_MEMBERS
@interface OFZIPArchive ()
- (void)of_readZIPInfo;
- (void)of_readEntries;
- (void)of_closeLastReturnedStream;
- (void)of_writeCentralDirectory;
@end

OF_DIRECT_MEMBERS
@interface OFZIPArchiveLocalFileHeader: OFObject
{
@public
	uint16_t _minVersionNeeded, _generalPurposeBitFlag, _compressionMethod;
	uint16_t _lastModifiedFileTime, _lastModifiedFileDate;
	uint32_t _CRC32;
	uint64_t _compressedSize, _uncompressedSize;
	OFString *_fileName;
	OFData *_extraField;
}

- (instancetype)initWithStream: (OFStream *)stream;
- (bool)matchesEntry: (OFZIPArchiveEntry *)entry;
@end

OF_DIRECT_MEMBERS
@interface OFZIPArchiveFileReadStream: OFStream
{
	OFStream *_stream, *_decompressedStream;
	OFZIPArchiveEntry *_entry;
	uint64_t _toRead;
	uint32_t _CRC32;
	bool _atEndOfStream;
}

- (instancetype)of_initWithStream: (OFStream *)stream
			    entry: (OFZIPArchiveEntry *)entry;
@end

OF_DIRECT_MEMBERS
@interface OFZIPArchiveFileWriteStream: OFStream
{
	OFStream *_stream;
	uint32_t _CRC32;
@public
	int64_t _bytesWritten;
	OFMutableZIPArchiveEntry *_entry;
}

- (instancetype)initWithStream: (OFStream *)stream
			 entry: (OFMutableZIPArchiveEntry *)entry;
@end

uint32_t
OFZIPArchiveReadField32(const uint8_t **data, uint16_t *size)
{
	uint32_t field = 0;

	if (*size < 4)
		@throw [OFInvalidFormatException exception];

	for (uint8_t i = 0; i < 4; i++)
		field |= (uint32_t)(*data)[i] << (i * 8);

	*data += 4;
	*size -= 4;

	return field;
}

uint64_t
OFZIPArchiveReadField64(const uint8_t **data, uint16_t *size)
{
	uint64_t field = 0;

	if (*size < 8)
		@throw [OFInvalidFormatException exception];

	for (uint8_t i = 0; i < 8; i++)
		field |= (uint64_t)(*data)[i] << (i * 8);

	*data += 8;
	*size -= 8;

	return field;
}

static void
seekOrThrowInvalidFormat(OFSeekableStream *stream,
    OFFileOffset offset, int whence)
{
	@try {
		[stream seekToOffset: offset whence: whence];
	} @catch (OFSeekFailedException *e) {
		if (e.errNo == EINVAL)
			@throw [OFInvalidFormatException exception];

		@throw e;
	}
}

@implementation OFZIPArchive
@synthesize archiveComment = _archiveComment;

+ (instancetype)archiveWithStream: (OFStream *)stream mode: (OFString *)mode
{
	return [[[self alloc] initWithStream: stream mode: mode] autorelease];
}

#ifdef OF_HAVE_FILES
+ (instancetype)archiveWithPath: (OFString *)path mode: (OFString *)mode
{
	return [[[self alloc] initWithPath: path mode: mode] autorelease];
}
#endif

- (instancetype)init
{
	OF_INVALID_INIT_METHOD
}

- (instancetype)initWithStream: (OFStream *)stream mode: (OFString *)mode
{
	self = [super init];

	@try {
		if ([mode isEqual: @"r"])
			_mode = modeRead;
		else if ([mode isEqual: @"w"])
			_mode = modeWrite;
		else if ([mode isEqual: @"a"])
			_mode = modeAppend;
		else
			@throw [OFInvalidArgumentException exception];

		_stream = [stream retain];
		_entries = [[OFMutableArray alloc] init];
		_pathToEntryMap = [[OFMutableDictionary alloc] init];

		if (_mode == modeRead || _mode == modeAppend) {
			if (![stream isKindOfClass: [OFSeekableStream class]])
				@throw [OFInvalidArgumentException exception];

			[self of_readZIPInfo];
			[self of_readEntries];
		}

		if (_mode == modeAppend) {
			_offset = _centralDirectoryOffset;
			seekOrThrowInvalidFormat((OFSeekableStream *)_stream,
			    (OFFileOffset)_offset, SEEK_SET);
		}
	} @catch (id e) {
		/*
		 * If we are in write or append mode, we do not want -[close]
		 * to write anything to it on error - after all, it might not
		 * be a ZIP file which we would destroy otherwise.
		 */
		[_stream release];
		_stream = nil;

		[self release];
		@throw e;
	}

	return self;
}

#ifdef OF_HAVE_FILES
- (instancetype)initWithPath: (OFString *)path mode: (OFString *)mode
{
	OFFile *file;

	if ([mode isEqual: @"a"])
		file = [[OFFile alloc] initWithPath: path mode: @"r+"];
	else
		file = [[OFFile alloc] initWithPath: path mode: mode];

	@try {
		self = [self initWithStream: file mode: mode];
	} @finally {
		[file release];
	}

	return self;
}
#endif

- (void)dealloc
{
	if (_stream != nil)
		[self close];

	[_stream release];
	[_archiveComment release];
	[_entries release];
	[_pathToEntryMap release];
	[_lastReturnedStream release];

	[super dealloc];
}

- (void)of_readZIPInfo
{
	void *pool = objc_autoreleasePoolPush();
	uint16_t commentLength;
	OFFileOffset offset = -22;
	bool valid = false;

	do {
		seekOrThrowInvalidFormat((OFSeekableStream *)_stream,
		    offset, SEEK_END);

		if ([_stream readLittleEndianInt32] == 0x06054B50) {
			valid = true;
			break;
		}
	} while (--offset >= -65557);

	if (!valid)
		@throw [OFInvalidFormatException exception];

	_diskNumber = [_stream readLittleEndianInt16];
	_centralDirectoryDisk = [_stream readLittleEndianInt16];
	_centralDirectoryEntriesInDisk = [_stream readLittleEndianInt16];
	_centralDirectoryEntries = [_stream readLittleEndianInt16];
	_centralDirectorySize = [_stream readLittleEndianInt32];
	_centralDirectoryOffset = [_stream readLittleEndianInt32];

	commentLength = [_stream readLittleEndianInt16];
	_archiveComment = [[_stream
	    readStringWithLength: commentLength
			encoding: OFStringEncodingCodepage437] copy];

	if (_diskNumber == 0xFFFF ||
	    _centralDirectoryDisk == 0xFFFF ||
	    _centralDirectoryEntriesInDisk == 0xFFFF ||
	    _centralDirectoryEntries == 0xFFFF ||
	    _centralDirectorySize == 0xFFFFFFFF ||
	    _centralDirectoryOffset == 0xFFFFFFFF) {
		int64_t offset64;
		uint64_t size;

		seekOrThrowInvalidFormat((OFSeekableStream *)_stream,
		    offset - 20, SEEK_END);

		if ([_stream readLittleEndianInt32] != 0x07064B50) {
			objc_autoreleasePoolPop(pool);
			return;
		}

		/*
		 * FIXME: Handle number of the disk containing ZIP64 end of
		 * central directory record.
		 */
		[_stream readLittleEndianInt32];
		offset64 = [_stream readLittleEndianInt64];

		if (offset64 < 0 || (OFFileOffset)offset64 != offset64)
			@throw [OFOutOfRangeException exception];

		seekOrThrowInvalidFormat((OFSeekableStream *)_stream,
		    (OFFileOffset)offset64, SEEK_SET);

		if ([_stream readLittleEndianInt32] != 0x06064B50)
			@throw [OFInvalidFormatException exception];

		size = [_stream readLittleEndianInt64];
		if (size < 44)
			@throw [OFInvalidFormatException exception];

		/* version made by */
		[_stream readLittleEndianInt16];
		/* version needed to extract */
		[_stream readLittleEndianInt16];

		_diskNumber = [_stream readLittleEndianInt32];
		_centralDirectoryDisk = [_stream readLittleEndianInt32];
		_centralDirectoryEntriesInDisk =
		    [_stream readLittleEndianInt64];
		_centralDirectoryEntries = [_stream readLittleEndianInt64];
		_centralDirectorySize = [_stream readLittleEndianInt64];
		_centralDirectoryOffset = [_stream readLittleEndianInt64];

		if (_centralDirectoryOffset < 0 ||
		    (OFFileOffset)_centralDirectoryOffset !=
		    _centralDirectoryOffset)
			@throw [OFOutOfRangeException exception];
	}

	objc_autoreleasePoolPop(pool);
}

- (void)of_readEntries
{
	void *pool = objc_autoreleasePoolPush();

	if (_centralDirectoryOffset < 0 ||
	    (OFFileOffset)_centralDirectoryOffset != _centralDirectoryOffset)
		@throw [OFOutOfRangeException exception];

	seekOrThrowInvalidFormat((OFSeekableStream *)_stream,
	    (OFFileOffset)_centralDirectoryOffset, SEEK_SET);

	for (size_t i = 0; i < _centralDirectoryEntries; i++) {
		OFZIPArchiveEntry *entry = [[[OFZIPArchiveEntry alloc]
		    of_initWithStream: _stream] autorelease];

		if ([_pathToEntryMap objectForKey: entry.fileName] != nil)
			@throw [OFInvalidFormatException exception];

		[_entries addObject: entry];
		[_pathToEntryMap setObject: entry forKey: entry.fileName];
	}

	objc_autoreleasePoolPop(pool);
}

- (OFArray *)entries
{
	return [[_entries copy] autorelease];
}

- (OFString *)archiveComment
{
	return _archiveComment;
}

- (void)setArchiveComment: (OFString *)comment
{
	void *pool = objc_autoreleasePoolPush();
	OFString *old;

	if (comment.UTF8StringLength > UINT16_MAX)
		@throw [OFOutOfRangeException exception];

	old = _archiveComment;
	_archiveComment = [comment copy];
	[old release];

	objc_autoreleasePoolPop(pool);
}

- (void)of_closeLastReturnedStream
{
	@try {
		[_lastReturnedStream close];
	} @catch (OFNotOpenException *e) {
		/* Might have already been closed by the user - that's fine. */
	}

	if ((_mode == modeWrite || _mode == modeAppend) &&
	    [_lastReturnedStream isKindOfClass:
	    [OFZIPArchiveFileWriteStream class]]) {
		OFZIPArchiveFileWriteStream *stream =
		    (OFZIPArchiveFileWriteStream *)_lastReturnedStream;

		if (INT64_MAX - _offset < stream->_bytesWritten)
			@throw [OFOutOfRangeException exception];

		_offset += stream->_bytesWritten;

		if (stream->_entry != nil) {
			[_entries addObject: stream->_entry];
			[_pathToEntryMap setObject: stream->_entry
					    forKey: [stream->_entry fileName]];
		}
	}

	[_lastReturnedStream release];
	_lastReturnedStream = nil;
}

- (OFStream *)streamForReadingFile: (OFString *)path
{
	void *pool = objc_autoreleasePoolPush();
	OFZIPArchiveEntry *entry;
	OFZIPArchiveLocalFileHeader *localFileHeader;
	int64_t offset64;

	if (_mode != modeRead)
		@throw [OFInvalidArgumentException exception];

	if ((entry = [_pathToEntryMap objectForKey: path]) == nil)
		@throw [OFOpenItemFailedException exceptionWithPath: path
							       mode: @"r"
							      errNo: ENOENT];

	[self of_closeLastReturnedStream];

	offset64 = entry.of_localFileHeaderOffset;
	if (offset64 < 0 || (OFFileOffset)offset64 != offset64)
		@throw [OFOutOfRangeException exception];

	seekOrThrowInvalidFormat((OFSeekableStream *)_stream,
	    (OFFileOffset)offset64, SEEK_SET);
	localFileHeader = [[[OFZIPArchiveLocalFileHeader alloc]
	    initWithStream: _stream] autorelease];

	if (![localFileHeader matchesEntry: entry])
		@throw [OFInvalidFormatException exception];

	if ((localFileHeader->_minVersionNeeded & 0xFF) > 45) {
		OFString *version = [OFString stringWithFormat: @"%u.%u",
		    (localFileHeader->_minVersionNeeded & 0xFF) / 10,
		    (localFileHeader->_minVersionNeeded & 0xFF) % 10];

		@throw [OFUnsupportedVersionException
		    exceptionWithVersion: version];
	}

	_lastReturnedStream = [[OFZIPArchiveFileReadStream alloc]
	     of_initWithStream: _stream
			 entry: entry];

	objc_autoreleasePoolPop(pool);

	return [[_lastReturnedStream retain] autorelease];
}

- (OFStream *)streamForWritingEntry: (OFZIPArchiveEntry *)entry_
{
	/* TODO: Avoid data descriptor when _stream is an OFSeekableStream */
	int64_t offsetAdd = 0;
	void *pool;
	OFMutableZIPArchiveEntry *entry;
	OFString *fileName;
	OFData *extraField;
	uint16_t fileNameLength, extraFieldLength;

	if (_mode != modeWrite && _mode != modeAppend)
		@throw [OFInvalidArgumentException exception];

	pool = objc_autoreleasePoolPush();
	entry = [[entry_ mutableCopy] autorelease];

	if ([_pathToEntryMap objectForKey: entry.fileName] != nil)
		@throw [OFOpenItemFailedException
		    exceptionWithPath: entry.fileName
				 mode: @"w"
				errNo: EEXIST];

	if (entry.compressionMethod != OFZIPArchiveEntryCompressionMethodNone)
		@throw [OFNotImplementedException exceptionWithSelector: _cmd
								 object: self];

	[self of_closeLastReturnedStream];

	fileName = entry.fileName;
	fileNameLength = fileName.UTF8StringLength;
	extraField = entry.extraField;
	extraFieldLength = extraField.count;

	if (UINT16_MAX - extraFieldLength < 20)
		@throw [OFOutOfRangeException exception];

	entry.versionMadeBy = (entry.versionMadeBy & 0xFF00) | 45;
	entry.minVersionNeeded = (entry.minVersionNeeded & 0xFF00) | 45;
	entry.compressedSize = 0;
	entry.uncompressedSize = 0;
	entry.CRC32 = 0;
	entry.generalPurposeBitFlag |= (1u << 3) | (1u << 11);
	entry.of_localFileHeaderOffset = _offset;

	[_stream writeLittleEndianInt32: 0x04034B50];
	[_stream writeLittleEndianInt16: entry.minVersionNeeded];
	[_stream writeLittleEndianInt16: entry.generalPurposeBitFlag];
	[_stream writeLittleEndianInt16: entry.compressionMethod];
	[_stream writeLittleEndianInt16: entry.of_lastModifiedFileTime];
	[_stream writeLittleEndianInt16: entry.of_lastModifiedFileDate];
	/* We use the data descriptor */
	[_stream writeLittleEndianInt32: 0];
	/* We use ZIP64 */
	[_stream writeLittleEndianInt32: 0xFFFFFFFF];
	[_stream writeLittleEndianInt32: 0xFFFFFFFF];
	[_stream writeLittleEndianInt16: fileNameLength];
	[_stream writeLittleEndianInt16: extraFieldLength + 20];
	offsetAdd += 4 + (5 * 2) + (3 * 4) + (2 * 2);

	[_stream writeString: fileName];
	offsetAdd += fileNameLength;

	[_stream writeLittleEndianInt16: OFZIPArchiveEntryExtraFieldTagZIP64];
	[_stream writeLittleEndianInt16: 16];
	/* We use the data descriptor */
	[_stream writeLittleEndianInt64: 0];
	[_stream writeLittleEndianInt64: 0];
	offsetAdd += (2 * 2) + (2 * 8);

	if (extraField != nil)
		[_stream writeData: extraField];
	offsetAdd += extraFieldLength;

	if (INT64_MAX - _offset < offsetAdd)
		@throw [OFOutOfRangeException exception];

	_offset += offsetAdd;

	_lastReturnedStream = [[OFZIPArchiveFileWriteStream alloc]
	     initWithStream: _stream
		      entry: entry];

	objc_autoreleasePoolPop(pool);

	return [[_lastReturnedStream retain] autorelease];
}

- (void)of_writeCentralDirectory
{
	void *pool = objc_autoreleasePoolPush();

	_centralDirectoryEntries = 0;
	_centralDirectoryEntriesInDisk = 0;
	_centralDirectorySize = 0;
	_centralDirectoryOffset = _offset;

	for (OFZIPArchiveEntry *entry in _entries) {
		_centralDirectorySize += [entry of_writeToStream: _stream];
		_centralDirectoryEntries++;
		_centralDirectoryEntriesInDisk++;
	}

	/* ZIP64 end of central directory */
	[_stream writeLittleEndianInt32: 0x06064B50];
	[_stream writeLittleEndianInt64: 44];	/* Remaining size */
	[_stream writeLittleEndianInt16: 45];	/* Version made by */
	[_stream writeLittleEndianInt16: 45];	/* Version required */
	[_stream writeLittleEndianInt32: _diskNumber];
	[_stream writeLittleEndianInt32: _centralDirectoryDisk];
	[_stream writeLittleEndianInt64: _centralDirectoryEntriesInDisk];
	[_stream writeLittleEndianInt64: _centralDirectoryEntries];
	[_stream writeLittleEndianInt64: _centralDirectorySize];
	[_stream writeLittleEndianInt64: _centralDirectoryOffset];

	/* ZIP64 end of central directory locator */
	[_stream writeLittleEndianInt32: 0x07064B50];
	[_stream writeLittleEndianInt32: _diskNumber];
	[_stream writeLittleEndianInt64:
	    _centralDirectoryOffset + _centralDirectorySize];
	[_stream writeLittleEndianInt32: 1];	/* Total number of disks */

	/* End of central directory */
	[_stream writeLittleEndianInt32: 0x06054B50];
	[_stream writeLittleEndianInt16: 0xFFFF];	/* Disk number */
	[_stream writeLittleEndianInt16: 0xFFFF];	/* CD disk */
	[_stream writeLittleEndianInt16: 0xFFFF];	/* CD entries in disk */
	[_stream writeLittleEndianInt16: 0xFFFF];	/* CD entries */
	[_stream writeLittleEndianInt32: 0xFFFFFFFF];	/* CD size */
	[_stream writeLittleEndianInt32: 0xFFFFFFFF];	/* CD offset */
	[_stream writeLittleEndianInt16: _archiveComment.UTF8StringLength];
	if (_archiveComment != nil)
		[_stream writeString: _archiveComment];

	objc_autoreleasePoolPop(pool);
}

- (void)close
{
	if (_stream == nil)
		@throw [OFNotOpenException exceptionWithObject: self];

	[self of_closeLastReturnedStream];

	if (_mode == modeWrite || _mode == modeAppend)
		[self of_writeCentralDirectory];

	[_stream release];
	_stream = nil;
}
@end

@implementation OFZIPArchiveLocalFileHeader
- (instancetype)initWithStream: (OFStream *)stream
{
	self = [super init];

	@try {
		void *pool = objc_autoreleasePoolPush();
		OFMutableData *extraField = nil;
		uint16_t fileNameLength, extraFieldLength;
		OFStringEncoding encoding;
		size_t ZIP64Index;
		uint16_t ZIP64Size;

		if ([stream readLittleEndianInt32] != 0x04034B50)
			@throw [OFInvalidFormatException exception];

		_minVersionNeeded = [stream readLittleEndianInt16];
		_generalPurposeBitFlag = [stream readLittleEndianInt16];
		_compressionMethod = [stream readLittleEndianInt16];
		_lastModifiedFileTime = [stream readLittleEndianInt16];
		_lastModifiedFileDate = [stream readLittleEndianInt16];
		_CRC32 = [stream readLittleEndianInt32];
		_compressedSize = [stream readLittleEndianInt32];
		_uncompressedSize = [stream readLittleEndianInt32];
		fileNameLength = [stream readLittleEndianInt16];
		extraFieldLength = [stream readLittleEndianInt16];
		encoding = (_generalPurposeBitFlag & (1u << 11)
		    ? OFStringEncodingUTF8 : OFStringEncodingCodepage437);

		_fileName = [[stream readStringWithLength: fileNameLength
						 encoding: encoding] copy];
		if (extraFieldLength > 0)
			extraField = [[[stream readDataWithCount:
			    extraFieldLength] mutableCopy] autorelease];

		ZIP64Index = OFZIPArchiveEntryExtraFieldFind(extraField,
		    OFZIPArchiveEntryExtraFieldTagZIP64, &ZIP64Size);

		if (ZIP64Index != OFNotFound) {
			const uint8_t *ZIP64 =
			    [extraField itemAtIndex: ZIP64Index];
			OFRange range =
			    OFRangeMake(ZIP64Index - 4, ZIP64Size + 4);

			if (_uncompressedSize == 0xFFFFFFFF)
				_uncompressedSize = OFZIPArchiveReadField64(
				    &ZIP64, &ZIP64Size);
			if (_compressedSize == 0xFFFFFFFF)
				_compressedSize = OFZIPArchiveReadField64(
				    &ZIP64, &ZIP64Size);

			if (ZIP64Size > 0)
				@throw [OFInvalidFormatException exception];

			[extraField removeItemsInRange: range];
		}

		if (extraField.count > 0) {
			[extraField makeImmutable];
			_extraField = [extraField copy];
		}

		objc_autoreleasePoolPop(pool);
	} @catch (id e) {
		[self release];
		@throw e;
	}

	return self;
}

- (void)dealloc
{
	[_fileName release];
	[_extraField release];

	[super dealloc];
}

- (bool)matchesEntry: (OFZIPArchiveEntry *)entry
{
	if (_compressionMethod != entry.compressionMethod ||
	    _lastModifiedFileTime != entry.of_lastModifiedFileTime ||
	    _lastModifiedFileDate != entry.of_lastModifiedFileDate)
		return false;

	if (!(_generalPurposeBitFlag & (1u << 3)))
		if (_CRC32 != entry.CRC32 ||
		    _compressedSize != entry.compressedSize ||
		    _uncompressedSize != entry.uncompressedSize)
			return false;

	if (![_fileName isEqual: entry.fileName])
		return false;

	return true;
}
@end

@implementation OFZIPArchiveFileReadStream
- (instancetype)of_initWithStream: (OFStream *)stream
			    entry: (OFZIPArchiveEntry *)entry
{
	self = [super init];

	@try {
		_stream = [stream retain];

		switch (entry.compressionMethod) {
		case OFZIPArchiveEntryCompressionMethodNone:
			_decompressedStream = [stream retain];
			break;
		case OFZIPArchiveEntryCompressionMethodDeflate:
			_decompressedStream = [[OFInflateStream alloc]
			    initWithStream: stream];
			break;
		case OFZIPArchiveEntryCompressionMethodDeflate64:
			_decompressedStream = [[OFInflate64Stream alloc]
			    initWithStream: stream];
			break;
		default:
			@throw [OFNotImplementedException
			    exceptionWithSelector: _cmd
					   object: nil];
		}

		_entry = [entry copy];
		_toRead = entry.uncompressedSize;
		_CRC32 = ~0;
	} @catch (id e) {
		[self release];
		@throw e;
	}

	return self;
}

- (void)dealloc
{
	if (_stream != nil || _decompressedStream != nil)
		[self close];

	[_entry release];

	[super dealloc];
}

- (bool)lowlevelIsAtEndOfStream
{
	if (_stream == nil)
		@throw [OFNotOpenException exceptionWithObject: self];

	return _atEndOfStream;
}

- (size_t)lowlevelReadIntoBuffer: (void *)buffer length: (size_t)length
{
	size_t ret;

	if (_stream == nil)
		@throw [OFNotOpenException exceptionWithObject: self];

	if (_atEndOfStream)
		return 0;

	if (_stream.atEndOfStream && !_decompressedStream.hasDataInReadBuffer)
		@throw [OFTruncatedDataException exception];

#if SIZE_MAX >= UINT64_MAX
	if (length > UINT64_MAX)
		@throw [OFOutOfRangeException exception];
#endif

	if ((uint64_t)length > _toRead)
		length = (size_t)_toRead;

	ret = [_decompressedStream readIntoBuffer: buffer length: length];

	_toRead -= ret;
	_CRC32 = OFCRC32(_CRC32, buffer, ret);

	if (_toRead == 0) {
		_atEndOfStream = true;

		if (~_CRC32 != _entry.CRC32) {
			OFString *actualChecksum = [OFString stringWithFormat:
			    @"%08" PRIX32, ~_CRC32];
			OFString *expectedChecksum = [OFString stringWithFormat:
			    @"%08" PRIX32, _entry.CRC32];

			@throw [OFChecksumMismatchException
			    exceptionWithActualChecksum: actualChecksum
				       expectedChecksum: expectedChecksum];
		}
	}

	return ret;
}

- (bool)hasDataInReadBuffer
{
	return (super.hasDataInReadBuffer ||
	    _decompressedStream.hasDataInReadBuffer);
}

- (int)fileDescriptorForReading
{
	return ((id <OFReadyForReadingObserving>)_decompressedStream)
	    .fileDescriptorForReading;
}

- (void)close
{
	if (_stream == nil || _decompressedStream == nil)
		@throw [OFNotOpenException exceptionWithObject: self];

	[_stream release];
	_stream = nil;

	[_decompressedStream release];
	_decompressedStream = nil;

	[super close];
}
@end

@implementation OFZIPArchiveFileWriteStream
- (instancetype)initWithStream: (OFStream *)stream
			 entry: (OFMutableZIPArchiveEntry *)entry
{
	self = [super init];

	_stream = [stream retain];
	_entry = [entry retain];
	_CRC32 = ~0;

	return self;
}

- (void)dealloc
{
	if (_stream != nil)
		[self close];

	[_entry release];

	[super dealloc];
}

- (size_t)lowlevelWriteBuffer: (const void *)buffer length: (size_t)length
{
#if SIZE_MAX >= INT64_MAX
	if (length > INT64_MAX)
		@throw [OFOutOfRangeException exception];
#endif

	if (INT64_MAX - _bytesWritten < (int64_t)length)
		@throw [OFOutOfRangeException exception];

	@try {
		[_stream writeBuffer: buffer length: length];
	} @catch (OFWriteFailedException *e) {
		OFEnsure(e.bytesWritten < length);

		_bytesWritten += (int64_t)e.bytesWritten;
		_CRC32 = OFCRC32(_CRC32, buffer, e.bytesWritten);

		if (e.errNo == EWOULDBLOCK)
			return e.bytesWritten;

		@throw e;
	}

	_bytesWritten += (int64_t)length;
	_CRC32 = OFCRC32(_CRC32, buffer, length);

	return length;
}

- (void)close
{
	if (_stream == nil)
		@throw [OFNotOpenException exceptionWithObject: self];

	[_stream writeLittleEndianInt32: 0x08074B50];
	[_stream writeLittleEndianInt32: _CRC32];
	[_stream writeLittleEndianInt64: _bytesWritten];
	[_stream writeLittleEndianInt64: _bytesWritten];

	[_stream release];
	_stream = nil;

	_entry.CRC32 = ~_CRC32;
	_entry.compressedSize = _bytesWritten;
	_entry.uncompressedSize = _bytesWritten;
	[_entry makeImmutable];

	_bytesWritten += (2 * 4 + 2 * 8);

	[super close];
}
@end