private ZipReturn ZipFileReadHeaders()
{
try
{
ZipReturn zRet = FindEndOfCentralDirSignature();
if (zRet != ZipReturn.ZipGood)
{
ZipFileClose();
return(zRet);
}
ulong endOfCentralDir = (ulong)_zipFs.Position;
zRet = EndOfCentralDirRead();
if (zRet != ZipReturn.ZipGood)
{
ZipFileClose();
return(zRet);
}
// check if ZIP64 header is required
bool zip64Required = (_centralDirStart == 0xffffffff || _centralDirSize == 0xffffffff || _localFilesCount == 0xffff);
// check for a ZIP64 header
_zipFs.Position = (long)endOfCentralDir - 20;
zRet = Zip64EndOfCentralDirectoryLocatorRead();
if (zRet == ZipReturn.ZipGood)
{
_zipFs.Position = (long)_endOfCentralDir64;
zRet = Zip64EndOfCentralDirRead();
if (zRet == ZipReturn.ZipGood)
{
_zip64 = true;
endOfCentralDir = _endOfCentralDir64;
}
}
if (zip64Required && !_zip64)
{
return(ZipReturn.Zip64EndOfCentralDirError);
}
offset = (endOfCentralDir - _centralDirSize) - _centralDirStart;
_centralDirStart += offset;
bool trrntzip = false;
// check if the ZIP has a valid TorrentZip file comment
if (FileComment.Length == 22)
{
if (CompressUtils.GetString(FileComment).Substring(0, 14) == "TORRENTZIPPED-")
{
CrcCalculatorStream crcCs = new(_zipFs, true);
byte[] buffer = new byte[_centralDirSize];
_zipFs.Position = (long)_centralDirStart;
crcCs.Read(buffer, 0, (int)_centralDirSize);
crcCs.Flush();
crcCs.Close();
uint r = (uint)crcCs.Crc;
crcCs.Dispose();
string tcrc = CompressUtils.GetString(FileComment).Substring(14, 8);
string zcrc = r.ToString("X8");
if (string.Compare(tcrc, zcrc, StringComparison.Ordinal) == 0)
{
trrntzip = true;
}
}
}
if (zip64Required != _zip64)
{
trrntzip = false;
}
// now read the central directory
_zipFs.Position = (long)_centralDirStart;
_localFiles.Clear();
_localFiles.Capacity = (int)_localFilesCount;
for (int i = 0; i < _localFilesCount; i++)
{
ZipLocalFile lc = new();
zRet = lc.CentralDirectoryRead(_zipFs, offset);
if (zRet != ZipReturn.ZipGood)
{
ZipFileClose();
return(zRet);
}
_zip64 |= lc.GetStatus(LocalFileStatus.Zip64);
_localFiles.Add(lc);
}
for (int i = 0; i < _localFilesCount; i++)
{
zRet = _localFiles[i].LocalFileHeaderRead(_zipFs);
if (zRet != ZipReturn.ZipGood)
{
ZipFileClose();
return(zRet);
}
trrntzip &= _localFiles[i].GetStatus(LocalFileStatus.TrrntZip);
}
// check trrntzip file order
if (trrntzip)
{
for (int i = 0; i < _localFilesCount - 1; i++)
{
if (CompressUtils.TrrntZipStringCompare(_localFiles[i].Filename, _localFiles[i + 1].Filename) < 0)
{
continue;
}
trrntzip = false;
break;
}
}
// check trrntzip directories
if (trrntzip)
{
for (int i = 0; i < _localFilesCount - 1; i++)
{
// see if we found a directory
string filename0 = _localFiles[i].Filename;
if (filename0.Substring(filename0.Length - 1, 1) != "/")
{
continue;
}
// see if the next file is in that directory
string filename1 = _localFiles[i + 1].Filename;
if (filename1.Length <= filename0.Length)
{
continue;
}
if (CompressUtils.TrrntZipStringCompare(filename0, filename1.Substring(0, filename0.Length)) != 0)
{
continue;
}
// if we found a file in the directory then we do not need the directory entry
trrntzip = false;
break;
}
}
if (trrntzip)
{
ZipStatus |= ZipStatus.TrrntZip;
}
return(ZipReturn.ZipGood);
}
catch
{
ZipFileClose();
return(ZipReturn.ZipErrorReadingFile);
}
}
/*
* raw is true if we are just going to copy the raw data stream from the source to the destination zip file
* trrntzip is thue if the source zip is a valid trrntzip file
* compressionMethod must be set to 8 to make a valid trrntzip file.
*
* if raw is false then compressionMthod must be 0,8 or 93 (zstd)
*/
public ZipReturn ZipFileOpenWriteStream(bool raw, bool trrntzip, string filename, ulong uncompressedSize, ushort compressionMethod, out Stream stream, TimeStamps timeStamp = null)
{
stream = null;
if (ZipOpen != ZipOpenType.OpenWrite)
{
return(ZipReturn.ZipWritingToInputFile);
}
ZipReturn validTrrntzip = ZipReturn.ZipGood;
//invalid torrentZip Input If:
if (compressionMethod != 8)
{
validTrrntzip = ZipReturn.ZipTrrntzipIncorrectCompressionUsed;
}
if (raw && !trrntzip)
{
validTrrntzip = ZipReturn.ZipTrrntZipIncorrectDataStream;
}
int localFilesCount = _localFiles.Count;
if (localFilesCount > 0)
{
// check that filenames are in trrntzip order
string lastFilename = _localFiles[localFilesCount - 1].Filename;
if (CompressUtils.TrrntZipStringCompare(lastFilename, filename) > 0)
{
validTrrntzip = ZipReturn.ZipTrrntzipIncorrectFileOrder;
}
// check that no un-needed directory entries are added
if (_localFiles[localFilesCount - 1].IsDirectory && filename.Length > lastFilename.Length)
{
if (CompressUtils.TrrntZipStringCompare(lastFilename, filename.Substring(0, lastFilename.Length)) == 0)
{
validTrrntzip = ZipReturn.ZipTrrntzipIncorrectDirectoryAddedToZip;
}
}
}
// if we are requirering a trrrntzp file and it is not a trrntzip formated supplied stream then error out
if (writeZipType == OutputZipType.TrrntZip)
{
if (validTrrntzip != ZipReturn.ZipGood)
{
return(validTrrntzip);
}
}
ZipLocalFile lf = new ZipLocalFile(filename, timeStamp);
lf.SetStatus(LocalFileStatus.TrrntZip, validTrrntzip == ZipReturn.ZipGood);
ZipReturn retVal = lf.LocalFileOpenWriteStream(_zipFs, raw, uncompressedSize, compressionMethod, out stream);
if (retVal != ZipReturn.ZipGood)
{
return(retVal);
}
if (filename.Length > 0)
{
lf.IsDirectory = (filename.Substring(filename.Length - 1, 1) == "/");
}
_compressionStream = stream;
_localFiles.Add(lf);
return(ZipReturn.ZipGood);
}
