ObjFW  Diff

#import "OFGZIPStream.h"
#import "OFInflateStream.h"
#import "OFDate.h"

#import "crc32.h"

#import "OFChecksumFailedException.h"
#import "OFChecksumMismatchException.h"
#import "OFInvalidFormatException.h"
#import "OFNotImplementedException.h"
#import "OFNotOpenException.h"
#import "OFTruncatedDataException.h"

@implementation OFGZIPStream
+ (instancetype)streamWithStream: (OFStream *)stream

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

	for (;;) {
		uint8_t byte;
		uint32_t CRC32, uncompressedSize;

		if ([_stream isAtEndOfStream]) {
			if (_state != OF_GZIP_STREAM_ID1)
				@throw [OFTruncatedDataException exception];

			return 0;
		}

		case OF_GZIP_STREAM_CRC32:
			_bytesRead += [_stream readIntoBuffer: _buffer
						       length: 4 - _bytesRead];

			if (_bytesRead < 4)
				return 0;

			if ((((uint32_t)_buffer[3] << 24) | (_buffer[2] << 16) |
			    (_buffer[1] << 8) | _buffer[0]) != ~_CRC32)
				@throw [OFChecksumFailedException exception];
			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 OF_GZIP_STREAM_UNCOMPRESSED_SIZE:
			_bytesRead += [_stream readIntoBuffer: _buffer
						       length: 4 - _bytesRead];

			if ((((uint32_t)_buffer[3] << 24) | (_buffer[2] << 16) |
			    (_buffer[1] << 8) | _buffer[0]) !=
			    _uncompressedSize)
				@throw [OFChecksumFailedException exception];
			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 = OF_GZIP_STREAM_ID1;
			break;
		}
	}