/* * 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" #import "OFGZIPStream.h" #import "OFCRC32.h" #import "OFDate.h" #import "OFInflateStream.h" #import "OFChecksumMismatchException.h" #import "OFInvalidFormatException.h" #import "OFNotImplementedException.h" #import "OFNotOpenException.h" #import "OFTruncatedDataException.h" @implementation OFGZIPStream @synthesize operatingSystemMadeOn = _operatingSystemMadeOn; @synthesize modificationDate = _modificationDate; + (instancetype)streamWithStream: (OFStream *)stream mode: (OFString *)mode { return [[[self alloc] initWithStream: stream mode: mode] autorelease]; } - (instancetype)init { OF_INVALID_INIT_METHOD } - (instancetype)initWithStream: (OFStream *)stream mode: (OFString *)mode { self = [super init]; @try { if (![mode isEqual: @"r"]) @throw [OFNotImplementedException exceptionWithSelector: _cmd object: nil]; _stream = [stream retain]; _operatingSystemMadeOn = OFGZIPStreamOperatingSystemUnknown; _CRC32 = ~0; } @catch (id e) { [self release]; @throw e; } return self; } - (void)dealloc { if (_stream != nil) [self close]; [_inflateStream release]; [_modificationDate release]; [super dealloc]; } - (size_t)lowlevelReadIntoBuffer: (void *)buffer length: (size_t)length { if (_stream == nil) @throw [OFNotOpenException exceptionWithObject: self]; for (;;) { uint8_t byte; uint32_t CRC32, uncompressedSize; if (_stream.atEndOfStream) { if (_state != OFGZIPStreamStateID1) @throw [OFTruncatedDataException exception]; return 0; } switch (_state) { case OFGZIPStreamStateID1: case OFGZIPStreamStateID2: case OFGZIPStreamStateCompressionMethod: if ([_stream readIntoBuffer: &byte length: 1] < 1) return 0; if ((_state == OFGZIPStreamStateID1 && byte != 0x1F) || (_state == OFGZIPStreamStateID2 && byte != 0x8B) || (_state == OFGZIPStreamStateCompressionMethod && byte != 8)) @throw [OFInvalidFormatException exception]; _state++; break; case OFGZIPStreamStateFlags: if ([_stream readIntoBuffer: &byte length: 1] < 1) return 0; _flags = byte; _state++; break; case OFGZIPStreamStateModificationDate: _bytesRead += [_stream readIntoBuffer: _buffer + _bytesRead length: 4 - _bytesRead]; if (_bytesRead < 4) return 0; [_modificationDate release]; _modificationDate = nil; _modificationDate = [[OFDate alloc] initWithTimeIntervalSince1970: (_buffer[3] << 24) | (_buffer[2] << 16) | (_buffer[1] << 8) | _buffer[0]]; _bytesRead = 0; _state++; break; case OFGZIPStreamStateExtraFlags: if ([_stream readIntoBuffer: &byte length: 1] < 1) return 0; _extraFlags = byte; _state++; break; case OFGZIPStreamStateOperatingSystem: if ([_stream readIntoBuffer: &byte length: 1] < 1) return 0; _operatingSystemMadeOn = byte; _state++; break; case OFGZIPStreamStateExtraLength: if (!(_flags & OFGZIPStreamFlagExtra)) { _state += 2; break; } _bytesRead += [_stream readIntoBuffer: _buffer + _bytesRead length: 2 - _bytesRead]; if (_bytesRead < 2) return 0; _extraLength = (_buffer[1] << 8) | _buffer[0]; _bytesRead = 0; _state++; break; case OFGZIPStreamStateExtra: { char tmp[512]; size_t toRead = _extraLength - _bytesRead; if (toRead > 512) toRead = 512; _bytesRead += [_stream readIntoBuffer: tmp length: toRead]; } if (_bytesRead < _extraLength) return 0; _bytesRead = 0; _state++; break; case OFGZIPStreamStateName: if (!(_flags & OFGZIPStreamFlagName)) { _state++; break; } do { if ([_stream readIntoBuffer: &byte length: 1] < 1) return 0; } while (byte != 0); _state++; break; case OFGZIPStreamStateComment: if (!(_flags & OFGZIPStreamFlagComment)) { _state++; break; } do { if ([_stream readIntoBuffer: &byte length: 1] < 1) return 0; } while (byte != 0); _state++; break; case OFGZIPStreamStateHeaderCRC16: if (!(_flags & OFGZIPStreamFlagHeaderCRC16)) { _state++; break; } _bytesRead += [_stream readIntoBuffer: _buffer + _bytesRead length: 2 - _bytesRead]; if (_bytesRead < 2) return 0; /* * Header CRC16 is not checked, as I could not find a * single file in the wild that actually has a header * CRC16 - and thus no file to test against. */ _bytesRead = 0; _state++; break; case OFGZIPStreamStateData: if (_inflateStream == nil) _inflateStream = [[OFInflateStream alloc] initWithStream: _stream]; if (!_inflateStream.atEndOfStream) { size_t bytesRead = [_inflateStream readIntoBuffer: buffer length: length]; _CRC32 = OFCRC32(_CRC32, buffer, bytesRead); _uncompressedSize += bytesRead; return bytesRead; } [_inflateStream release]; _inflateStream = nil; _state++; break; case OFGZIPStreamStateCRC32: _bytesRead += [_stream readIntoBuffer: _buffer length: 4 - _bytesRead]; if (_bytesRead < 4) return 0; CRC32 = ((uint32_t)_buffer[3] << 24) | (_buffer[2] << 16) | (_buffer[1] << 8) | _buffer[0]; if (~_CRC32 != CRC32) { OFString *actual = [OFString stringWithFormat: @"%08" PRIX32, ~_CRC32]; OFString *expected = [OFString stringWithFormat: @"%08" PRIX32, CRC32]; @throw [OFChecksumMismatchException exceptionWithActualChecksum: actual expectedChecksum: expected]; } _bytesRead = 0; _CRC32 = ~0; _state++; break; case OFGZIPStreamStateUncompressedSize: _bytesRead += [_stream readIntoBuffer: _buffer length: 4 - _bytesRead]; uncompressedSize = ((uint32_t)_buffer[3] << 24) | (_buffer[2] << 16) | (_buffer[1] << 8) | _buffer[0]; if (_uncompressedSize != uncompressedSize) { OFString *actual = [OFString stringWithFormat: @"%" PRIu32, _uncompressedSize]; OFString *expected = [OFString stringWithFormat: @"%" PRIu32, uncompressedSize]; @throw [OFChecksumMismatchException exceptionWithActualChecksum: actual expectedChecksum: expected]; } _bytesRead = 0; _uncompressedSize = 0; _state = OFGZIPStreamStateID1; break; } } } - (bool)lowlevelIsAtEndOfStream { if (_stream == nil) @throw [OFNotOpenException exceptionWithObject: self]; return _stream.atEndOfStream; } - (bool)hasDataInReadBuffer { if (_state == OFGZIPStreamStateData) return (super.hasDataInReadBuffer || _inflateStream.hasDataInReadBuffer); return (super.hasDataInReadBuffer || _stream.hasDataInReadBuffer); } - (void)close { if (_stream == nil) @throw [OFNotOpenException exceptionWithObject: self]; [_stream release]; _stream = nil; [super close]; } @end