public ZipReturn ReadGZip(string filename, bool deepScan)
{
_filename = "";
if (!IO.File.Exists(filename))
{
return ZipReturn.ZipErrorFileNotFound;
}
_filename = filename;
int errorCode = IO.FileStream.OpenFileRead(filename, out _zipFs);
if (errorCode != 0)
{
if (errorCode == 32)
return ZipReturn.ZipFileLocked;
return ZipReturn.ZipErrorOpeningFile;
}
BinaryReader zipBr = new BinaryReader(_zipFs);
byte ID1 = zipBr.ReadByte();
byte ID2 = zipBr.ReadByte();
if (ID1 != 0x1f || ID2 != 0x8b)
{
_zipFs.Close();
return ZipReturn.ZipSignatureError;
}
byte CM = zipBr.ReadByte();
if (CM != 8)
{
_zipFs.Close();
return ZipReturn.ZipUnsupportedCompression;
}
byte FLG = zipBr.ReadByte();
UInt32 MTime = zipBr.ReadUInt32();
byte XFL = zipBr.ReadByte();
byte OS = zipBr.ReadByte();
//if FLG.FEXTRA set
if ((FLG & 0x4) == 0x4)
{
int XLen = zipBr.ReadInt16();
byte[] bytes = zipBr.ReadBytes(XLen);
if (XLen == 28)
{
md5Hash = new byte[16];
Array.Copy(bytes, 0, md5Hash, 0, 16);
crc = new byte[4];
Array.Copy(bytes, 16, crc, 0, 4);
uncompressedSize = BitConverter.ToUInt64(bytes, 20);
}
}
//if FLG.FNAME set
if ((FLG & 0x8) == 0x8)
{
int XLen = zipBr.ReadInt16();
byte[] bytes = zipBr.ReadBytes(XLen);
}
//if FLG.FComment set
if ((FLG & 0x10) == 0x10)
{
int XLen = zipBr.ReadInt16();
byte[] bytes = zipBr.ReadBytes(XLen);
}
//if FLG.FHCRC set
if ((FLG & 0x2) == 0x2)
{
uint crc16 = zipBr.ReadUInt16();
}
compressedSize = (ulong)(_zipFs.Length - _zipFs.Position) - 8;
datapos = _zipFs.Position;
if (deepScan)
{
Stream sInput = new DeflateStream(_zipFs, CompressionMode.Decompress, true);
CRC32Hash crc32 = new CRC32Hash();
MD5 lmd5 = MD5.Create();
SHA1 lsha1 = SHA1.Create();
if (_buffer == null)
_buffer = new byte[Buffersize];
ulong uncompressedRead = 0;
int sizeRead = 1;
while (sizeRead > 0)
{
sizeRead = sInput.Read(_buffer, 0, Buffersize);
if (sizeRead > 0)
{
crc32.TransformBlock(_buffer, 0, sizeRead, null, 0);
lmd5.TransformBlock(_buffer, 0, sizeRead, null, 0);
lsha1.TransformBlock(_buffer, 0, sizeRead, null, 0);
}
uncompressedRead += (ulong)sizeRead;
}
crc32.TransformFinalBlock(_buffer, 0, 0);
lmd5.TransformFinalBlock(_buffer, 0, 0);
lsha1.TransformFinalBlock(_buffer, 0, 0);
sInput.Close();
sInput.Dispose();
if (uncompressedSize != 0)
{
if (uncompressedSize != uncompressedRead)
{
_zipFs.Close();
return ZipReturn.ZipDecodeError;
}
}
else
uncompressedSize = uncompressedRead;
byte[] testcrc = crc32.Hash;
if (crc != null)
{
for (int i = 0; i < 4; i++)
{
if (crc[i] == testcrc[i]) continue;
_zipFs.Close();
return ZipReturn.ZipDecodeError;
}
}
else
crc = testcrc;
byte[] testmd5 = lmd5.Hash;
if (md5Hash != null)
{
for (int i = 0; i < 16; i++)
{
if (md5Hash[i] == testmd5[i]) continue;
_zipFs.Close();
return ZipReturn.ZipDecodeError;
}
}
else
md5Hash = testmd5;
byte[] testsha1 = lsha1.Hash;
if (sha1Hash != null)
{
for (int i = 0; i < 20; i++)
{
if (sha1Hash[i] == testsha1[i]) continue;
_zipFs.Close();
return ZipReturn.ZipDecodeError;
}
}
else
sha1Hash = testsha1;
sInput.Close();
sInput.Dispose();
}
_zipFs.Position = _zipFs.Length - 8;
byte[] gzcrc = zipBr.ReadBytes(4);
uint gzLength = zipBr.ReadUInt32();
if (crc != null)
{
for (int i = 0; i < 4; i++)
{
if (gzcrc[3 - i] == crc[i]) continue;
_zipFs.Close();
return ZipReturn.ZipDecodeError;
}
}
else
crc = new[] { gzcrc[3], gzcrc[2], gzcrc[1], gzcrc[0] };
if (uncompressedSize != 0)
{
if (gzLength != (uncompressedSize & 0xffffffff))
{
_zipFs.Close();
return ZipReturn.ZipDecodeError;
}
}
_zipFs.Close();
return ZipReturn.ZipGood;
}
public void LocalFileCheck()
{
if (FileStatus != ZipReturn.ZipUntested) return;
try
{
Stream sInput = null;
_zipFs.Seek((long)_dataLocation, SeekOrigin.Begin);
switch (_compressionMethod)
{
case 8:
sInput = new DeflateStream(_zipFs, CompressionMode.Decompress, true);
break;
case 0:
sInput = _zipFs;
break;
}
if (sInput == null)
{
FileStatus = ZipReturn.ZipErrorGettingDataStream;
return;
}
CRC32Hash crc32 = new CRC32Hash();
MD5 lmd5 = System.Security.Cryptography.MD5.Create();
SHA1 lsha1 = System.Security.Cryptography.SHA1.Create();
ulong sizetogo = UncompressedSize;
if (_buffer == null)
_buffer = new byte[Buffersize];
while (sizetogo > 0)
{
int sizenow = sizetogo > Buffersize ? Buffersize : (int)sizetogo;
sInput.Read(_buffer, 0, sizenow);
crc32.TransformBlock(_buffer, 0, sizenow, null, 0);
lmd5.TransformBlock(_buffer, 0, sizenow, null, 0);
lsha1.TransformBlock(_buffer, 0, sizenow, null, 0);
sizetogo = sizetogo - (ulong)sizenow;
}
crc32.TransformFinalBlock(_buffer, 0, 0);
lmd5.TransformFinalBlock(_buffer, 0, 0);
lsha1.TransformFinalBlock(_buffer, 0, 0);
byte[] testcrc = crc32.Hash;
md5 = lmd5.Hash;
sha1 = lsha1.Hash;
if (_compressionMethod == 8)
{
sInput.Close();
sInput.Dispose();
}
FileStatus = ByteArrCompare(CRC, testcrc) ? ZipReturn.ZipGood : ZipReturn.ZipCRCDecodeError;
}
catch
{
FileStatus = ZipReturn.ZipDecodeError;
}
}
public ZipReturn WriteGZip(string filename, Stream sInput, bool isCompressedStream)
{
CreateDirForFile(filename);
Stream _zipFs;
IO.FileStream.OpenFileWrite(filename, out _zipFs);
BinaryWriter zipBw = new BinaryWriter(_zipFs);
zipBw.Write((byte)0x1f); // ID1 = 0x1f
zipBw.Write((byte)0x8b); // ID2 = 0x8b
zipBw.Write((byte)0x08); // CM = 0x08
zipBw.Write((byte)0x04); // FLG = 0x04
zipBw.Write((UInt32)0); // MTime = 0
zipBw.Write((byte)0x00); // XFL = 0x00
zipBw.Write((byte)0xff); // OS = 0x00
// writing FEXTRA
zipBw.Write((Int16)28); // XLEN
zipBw.Write(md5Hash);
zipBw.Write(crc);
zipBw.Write(uncompressedSize);
if (_buffer == null)
_buffer = new byte[Buffersize];
ulong dataStartPos =(ulong) zipBw.BaseStream.Position;
if (isCompressedStream)
{
ulong sizetogo = compressedSize;
while (sizetogo > 0)
{
int sizenow = sizetogo > Buffersize ? Buffersize : (int)sizetogo;
sInput.Read(_buffer, 0, sizenow);
_zipFs.Write(_buffer, 0, sizenow);
sizetogo -= (ulong)sizenow;
}
}
else
{
ulong sizetogo = uncompressedSize;
Stream writeStream = new DeflateStream(_zipFs, CompressionMode.Compress, CompressionLevel.BestCompression, true);
while (sizetogo > 0)
{
int sizenow = sizetogo > Buffersize ? Buffersize : (int)sizetogo;
sInput.Read(_buffer, 0, sizenow);
writeStream.Write(_buffer, 0, sizenow);
sizetogo -= (ulong)sizenow;
}
writeStream.Flush();
writeStream.Close();
writeStream.Dispose();
}
compressedSize = (ulong)zipBw.BaseStream.Position - dataStartPos;
zipBw.Write(crc[3]);
zipBw.Write(crc[2]);
zipBw.Write(crc[1]);
zipBw.Write(crc[0]);
zipBw.Write((UInt32)uncompressedSize);
zipBw.Flush();
zipBw.Close();
_zipFs.Close();
return ZipReturn.ZipGood;
}