private byte[] GetExtraField()
{
byte[] block = null;
//var data = new System.Collections.Generic.List<byte>();
if ((UsesEncryption) && (IsStrong(Encryption)))
{
// byte[] block= GetStrongEncryptionBlock();
// return block;
}
#if INFOZIP_UTF8
if (FileNameIsUtf8(FileNameChars))
{
_FilenameIsUtf8= true;
int datasize= 2+2+1+4+FileNameChars.Length;
block= new byte[datasize];
int i=0, mark=0;
uint d= (uint) (datasize -4);
block[i++]= 0x75;
block[i++]= 0x70;
block[i++]= (byte)(d & 0x00FF);
block[i++]= (byte)(d & 0xFF00);
// version
block[i++]= 1;
// skip the CRC on the filenamebytes, for now
mark = i;
i+= 4;
// UTF8 filename
for (int j = 0; j < FileNameChars.Length; j++)
{
byte[] b = System.BitConverter.GetBytes(FileNameChars[j]);
block[i++]= b[0];
}
// filename field Crc32 - for the non-UTF8 filename field
CRC32 Crc32= new CRC32();
Crc32.SlurpBlock(block, mark+4, FileNameChars.Length);
i= mark;
block[i++] = (byte)(Crc32.Crc32Result & 0x000000FF);
block[i++] = (byte)((Crc32.Crc32Result & 0x0000FF00) >> 8);
block[i++] = (byte)((Crc32.Crc32Result & 0x00FF0000) >> 16);
block[i++] = (byte)((Crc32.Crc32Result & 0xFF000000) >> 24);
}
#endif
// could inject other blocks here...
return block;
}
/// <summary>
/// The constructor.
/// </summary>
/// <param name="stream">The underlying stream</param>
/// <param name="length">The length of the stream to slurp</param>
public CrcCalculatorStream(System.IO.Stream stream, int length)
: base()
{
_InnerStream = stream;
_Crc32 = new CRC32();
_length = length;
}
private Int32 FigureCrc32()
{
if (_crcCalculated == false)
{
Stream input = null;
// get the original stream:
if (_sourceStream != null)
{
_sourceStream.Position = 0;
input = _sourceStream;
}
else
{
input = System.IO.File.OpenRead(LocalFileName);
}
var crc32 = new CRC32();
_Crc32 = crc32.GetCrc32(input);
if (_sourceStream == null)
{
input.Close();
input.Dispose();
}
_crcCalculated = true;
}
return _Crc32;
}
/// <summary>
/// The constructor.
/// </summary>
/// <param name="stream">The underlying stream</param>
public CrcCalculatorStream(System.IO.Stream stream)
: base()
{
_InnerStream = stream;
_Crc32 = new CRC32();
}