private bool WriteLocalFileHeader(bool isEmptyFile)
{
uint maxValue;
uint num2;
ushort num4;
BinaryWriter writer = new BinaryWriter(_archive.ArchiveStream);
Zip64ExtraField field = new Zip64ExtraField();
bool flag = false;
if (isEmptyFile)
{
CompressionMethod = CompressionMethodValues.Stored;
maxValue = 0;
num2 = 0;
}
else if (((_archive.Mode == ZipArchiveMode.Create) && !_archive.ArchiveStream.CanSeek) && !isEmptyFile)
{
_generalPurposeBitFlag |= BitFlagValues.DataDescriptor;
flag = false;
maxValue = 0;
num2 = 0;
}
else if (SizesTooLarge())
{
flag = true;
maxValue = uint.MaxValue;
num2 = uint.MaxValue;
field.CompressedSize = new long?(_compressedSize);
field.UncompressedSize = new long?(_uncompressedSize);
VersionToExtractAtLeast(ZipVersionNeededValues.Zip64);
}
else
{
flag = false;
maxValue = (uint)_compressedSize;
num2 = (uint)_uncompressedSize;
}
_offsetOfLocalHeader = writer.BaseStream.Position;
int num3 = (flag ? field.TotalSize : 0) + ((_lhUnknownExtraFields != null) ? ZipGenericExtraField.TotalSize(_lhUnknownExtraFields) : 0);
if (num3 > 0xffff)
{
num4 = flag ? field.TotalSize : ((ushort)0);
_lhUnknownExtraFields = null;
}
else
{
num4 = (ushort)num3;
}
writer.Write((uint)0x4034b50);
writer.Write((ushort)_versionToExtract);
writer.Write((ushort)_generalPurposeBitFlag);
writer.Write((ushort)CompressionMethod);
writer.Write(ZipHelper.DateTimeToDosTime(_lastModified.DateTime));
writer.Write(_crc32);
writer.Write(maxValue);
writer.Write(num2);
writer.Write((ushort)_storedEntryNameBytes.Length);
writer.Write(num4);
writer.Write(_storedEntryNameBytes);
if (flag)
{
field.WriteBlock(_archive.ArchiveStream);
}
if (_lhUnknownExtraFields != null)
{
ZipGenericExtraField.WriteAllBlocks(_lhUnknownExtraFields, _archive.ArchiveStream);
}
return(flag);
}
private void ReadEndOfCentralDirectory()
{
try
{
ZipEndOfCentralDirectoryBlock block;
ArchiveStream1.Seek(-18L, SeekOrigin.End);
if (!ZipHelper.SeekBackwardsToSignature(ArchiveStream1, 0x6054b50))
{
throw new InvalidDataException(Messages.EOCDNotFound);
}
long position = ArchiveStream1.Position;
ZipEndOfCentralDirectoryBlock.TryReadBlock(_archiveReader, out block);
if (block.NumberOfThisDisk != block.NumberOfTheDiskWithTheStartOfTheCentralDirectory)
{
throw new InvalidDataException(Messages.SplitSpanned);
}
_numberOfThisDisk = block.NumberOfThisDisk;
_centralDirectoryStart = block.OffsetOfStartOfCentralDirectoryWithRespectToTheStartingDiskNumber;
if (block.NumberOfEntriesInTheCentralDirectory != block.NumberOfEntriesInTheCentralDirectoryOnThisDisk)
{
throw new InvalidDataException(Messages.SplitSpanned);
}
_expectedNumberOfEntries = block.NumberOfEntriesInTheCentralDirectory;
if (_mode == ZipArchiveMode.Update)
{
_archiveComment = block.ArchiveComment;
}
if (((block.NumberOfThisDisk == 0xffff) || (block.OffsetOfStartOfCentralDirectoryWithRespectToTheStartingDiskNumber == uint.MaxValue)) || (block.NumberOfEntriesInTheCentralDirectory == 0xffff))
{
ArchiveStream1.Seek(position - 0x10L, SeekOrigin.Begin);
if (ZipHelper.SeekBackwardsToSignature(ArchiveStream1, 0x7064b50))
{
Zip64EndOfCentralDirectoryLocator locator;
Zip64EndOfCentralDirectoryRecord record;
Zip64EndOfCentralDirectoryLocator.TryReadBlock(_archiveReader, out locator);
if (locator.OffsetOfZip64EOCD > 0x7fffffffffffffffL)
{
throw new InvalidDataException(Messages.FieldTooBigOffsetToZip64EOCD);
}
long offset = (long)locator.OffsetOfZip64EOCD;
ArchiveStream1.Seek(offset, SeekOrigin.Begin);
if (!Zip64EndOfCentralDirectoryRecord.TryReadBlock(_archiveReader, out record))
{
throw new InvalidDataException(Messages.Zip64EOCDNotWhereExpected);
}
_numberOfThisDisk = record.NumberOfThisDisk;
if (record.NumberOfEntriesTotal > 0x7fffffffffffffffL)
{
throw new InvalidDataException(Messages.FieldTooBigNumEntries);
}
if (record.OffsetOfCentralDirectory > 0x7fffffffffffffffL)
{
throw new InvalidDataException(Messages.FieldTooBigOffsetToCD);
}
if (record.NumberOfEntriesTotal != record.NumberOfEntriesOnThisDisk)
{
throw new InvalidDataException(Messages.SplitSpanned);
}
_expectedNumberOfEntries = (long)record.NumberOfEntriesTotal;
_centralDirectoryStart = (long)record.OffsetOfCentralDirectory;
}
}
if (_centralDirectoryStart > ArchiveStream1.Length)
{
throw new InvalidDataException(Messages.FieldTooBigOffsetToCD);
}
}
catch (EndOfStreamException exception)
{
throw new InvalidDataException(Messages.CDCorrupt, exception);
}
catch (IOException exception2)
{
throw new InvalidDataException(Messages.CDCorrupt, exception2);
}
}
internal void WriteCentralDirectoryFileHeader()
{
uint maxValue;
uint num2;
uint num3;
ushort num5;
BinaryWriter writer = new BinaryWriter(_archive.ArchiveStream);
Zip64ExtraField field = new Zip64ExtraField();
bool flag = false;
if (SizesTooLarge())
{
flag = true;
maxValue = uint.MaxValue;
num2 = uint.MaxValue;
field.CompressedSize = new long?(_compressedSize);
field.UncompressedSize = new long?(_uncompressedSize);
}
else
{
maxValue = (uint)_compressedSize;
num2 = (uint)_uncompressedSize;
}
if (_offsetOfLocalHeader > 0xffffffffL)
{
flag = true;
num3 = uint.MaxValue;
field.LocalHeaderOffset = new long?(_offsetOfLocalHeader);
}
else
{
num3 = (uint)_offsetOfLocalHeader;
}
if (flag)
{
VersionToExtractAtLeast(ZipVersionNeededValues.Zip64);
}
int num4 = (flag ? field.TotalSize : 0) + ((_cdUnknownExtraFields != null) ? ZipGenericExtraField.TotalSize(_cdUnknownExtraFields) : 0);
if (num4 > 0xffff)
{
num5 = flag ? field.TotalSize : ((ushort)0);
_cdUnknownExtraFields = null;
}
else
{
num5 = (ushort)num4;
}
writer.Write((uint)0x2014b50);
writer.Write((ushort)_versionToExtract);
writer.Write((ushort)_versionToExtract);
writer.Write((ushort)_generalPurposeBitFlag);
writer.Write((ushort)CompressionMethod);
writer.Write(ZipHelper.DateTimeToDosTime(_lastModified.DateTime));
writer.Write(_crc32);
writer.Write(maxValue);
writer.Write(num2);
writer.Write((ushort)_storedEntryNameBytes.Length);
writer.Write(num5);
writer.Write((_fileComment != null) ? ((ushort)_fileComment.Length) : ((ushort)0));
writer.Write((ushort)0);
writer.Write((ushort)0);
writer.Write((uint)0);
writer.Write(num3);
writer.Write(_storedEntryNameBytes);
if (flag)
{
field.WriteBlock(_archive.ArchiveStream);
}
if (_cdUnknownExtraFields != null)
{
ZipGenericExtraField.WriteAllBlocks(_cdUnknownExtraFields, _archive.ArchiveStream);
}
if (_fileComment != null)
{
writer.Write(_fileComment);
}
}
