internal ZipReturn LocalFileHeaderReadQuick(Stream zipFs)
{
try
{
using BinaryReader br = new(zipFs, Encoding.UTF8, true);
SetStatus(LocalFileStatus.TrrntZip);
zipFs.Position = (long)RelativeOffsetOfLocalHeader;
uint thisSignature = br.ReadUInt32();
if (thisSignature != LocalFileHeaderSignature)
{
return(ZipReturn.ZipLocalFileHeaderError);
}
br.ReadUInt16(); // version needed to extract
GeneralPurposeBitFlag = br.ReadUInt16();
if ((GeneralPurposeBitFlag & 8) == 8)
{
return(ZipReturn.ZipCannotFastOpen);
}
_compressionMethod = br.ReadUInt16();
ushort lastModFileTime = br.ReadUInt16();
ushort lastModFileDate = br.ReadUInt16();
HeaderLastModified = CompressUtils.UtcTicksFromDosDateTime(lastModFileDate, lastModFileTime);
CRC = ReadCRC(br);
_compressedSize = br.ReadUInt32();
UncompressedSize = br.ReadUInt32();
ushort fileNameLength = br.ReadUInt16();
ushort extraFieldLength = br.ReadUInt16();
byte[] bFileName = br.ReadBytes(fileNameLength);
Filename = (GeneralPurposeBitFlag & (1 << 11)) == 0
? CompressUtils.GetString(bFileName)
: Encoding.UTF8.GetString(bFileName, 0, fileNameLength);
SetStatus(LocalFileStatus.Zip64, false);
if (extraFieldLength > 0)
{
byte[] extraField = br.ReadBytes(extraFieldLength);
ulong LocalHeader = 0;
ZipReturn zr = ZipExtraField.ReadExtraField(extraField, bFileName, this, ref _compressedSize, ref LocalHeader, false);
if (zr != ZipReturn.ZipGood)
{
return(zr);
}
}
if (CompressUtils.IsCodePage437(Filename) != ((GeneralPurposeBitFlag & (1 << 11)) == 0))
{
SetStatus(LocalFileStatus.TrrntZip, false);
}
_dataLocation = (ulong)zipFs.Position;
return(ZipReturn.ZipGood);
}
catch
{
return(ZipReturn.ZipLocalFileHeaderError);
}
}
internal ZipReturn CentralDirectoryRead(Stream zipFs, ulong offset)
{
try
{
using BinaryReader br = new(zipFs, Encoding.UTF8, true);
uint thisSignature = br.ReadUInt32();
if (thisSignature != CentralDirectoryHeaderSignature)
{
return(ZipReturn.ZipCentralDirError);
}
br.ReadUInt16(); // Version Made By
br.ReadUInt16(); // Version Needed To Extract
GeneralPurposeBitFlag = br.ReadUInt16();
_compressionMethod = br.ReadUInt16();
ushort lastModFileTime = br.ReadUInt16();
ushort lastModFileDate = br.ReadUInt16();
HeaderLastModified = CompressUtils.UtcTicksFromDosDateTime(lastModFileDate, lastModFileTime);
CRC = ReadCRC(br);
_compressedSize = br.ReadUInt32();
UncompressedSize = br.ReadUInt32();
ushort fileNameLength = br.ReadUInt16();
ushort extraFieldLength = br.ReadUInt16();
ushort fileCommentLength = br.ReadUInt16();
br.ReadUInt16(); // diskNumberStart
br.ReadUInt16(); // internalFileAttributes
br.ReadUInt32(); // externalFileAttributes
RelativeOffsetOfLocalHeader = br.ReadUInt32();
byte[] bFileName = br.ReadBytes(fileNameLength);
Filename = (GeneralPurposeBitFlag & (1 << 11)) == 0
? CompressUtils.GetString(bFileName)
: Encoding.UTF8.GetString(bFileName, 0, fileNameLength);
if (extraFieldLength > 0)
{
byte[] extraField = br.ReadBytes(extraFieldLength);
ZipReturn zr = ZipExtraField.ReadExtraField(extraField, bFileName, this, ref _compressedSize, ref RelativeOffsetOfLocalHeader, true);
if (zr != ZipReturn.ZipGood)
{
return(zr);
}
}
RelativeOffsetOfLocalHeader += offset;
if (CompressUtils.IsCodePage437(Filename) != ((GeneralPurposeBitFlag & (1 << 11)) == 0))
{
SetStatus(LocalFileStatus.TrrntZip, false);
}
if (fileCommentLength > 0)
{
byte[] fileComment = br.ReadBytes(fileCommentLength);
}
if (Filename.Length > 0)
{
char lastChar = Filename[Filename.Length - 1];
IsDirectory = (lastChar == '/' || lastChar == '\\');
if (IsDirectory && UncompressedSize > 0)
{
SetStatus(LocalFileStatus.DirectoryLengthError);
}
}
/*
* 4.4.5 compression method: (2 bytes)
*
* 0 - (Supported) The file is stored (no compression)
* 1 - (Supported) The file is Shrunk
* 2 - (Supported) The file is Reduced with compression factor 1
* 3 - (Supported) The file is Reduced with compression factor 2
* 4 - (Supported) The file is Reduced with compression factor 3
* 5 - (Supported) The file is Reduced with compression factor 4
* 6 - (Supported) The file is Imploded
* 7 - Reserved for Tokenizing compression algorithm
* 8 - (Supported) The file is Deflated
* 9 - (Supported) Enhanced Deflating using Deflate64(tm)
* 10 - PKWARE Data Compression Library Imploding (old IBM TERSE)
* 11 - Reserved by PKWARE
* 12 - (Supported) File is compressed using BZIP2 algorithm
* 13 - Reserved by PKWARE
* 14 - (Supported) LZMA
* 15 - Reserved by PKWARE
* 16 - IBM z/OS CMPSC Compression
* 17 - Reserved by PKWARE
* 18 - File is compressed using IBM TERSE (new)
* 19 - IBM LZ77 z Architecture
* 20 - deprecated (use method 93 for zstd)
* 93 - (Supported, with external DLL) Zstandard (zstd) Compression
* 94 - MP3 Compression
* 95 - XZ Compression
* 96 - JPEG variant
* 97 - WavPack compressed data
* 98 - (Supported) PPMd version I, Rev 1
* 99 - AE-x encryption marker (see APPENDIX E)
*/
switch (_compressionMethod)
{
case 0: // The file is stored (no compression)
case 8: // The file is Deflated
case 9: // Enhanced Deflating using Deflate64(tm)
case 12: // The file is BZIP2 algorithm.
case 14: // LZMA
return(ZipReturn.ZipGood);
case 20:
case 93: // Zstandard (zstd) Compression
return(ZipReturn.ZipGood);
case 98: // PPMd version I, Rev 1
return(ZipReturn.ZipGood);
default:
return(ZipReturn.ZipUnsupportedCompression);
}
}
catch
{
return(ZipReturn.ZipCentralDirError);
}
}
internal ZipReturn LocalFileHeaderRead(Stream zipFs)
{
try
{
using (BinaryReader br = new(zipFs, Encoding.UTF8, true))
{
SetStatus(LocalFileStatus.TrrntZip);
zipFs.Position = (long)RelativeOffsetOfLocalHeader;
uint thisSignature = br.ReadUInt32();
if (thisSignature != LocalFileHeaderSignature)
{
return(ZipReturn.ZipLocalFileHeaderError);
}
br.ReadUInt16(); // version needed to extract
ushort generalPurposeBitFlagLocal = br.ReadUInt16();
if (generalPurposeBitFlagLocal != GeneralPurposeBitFlag)
{
SetStatus(LocalFileStatus.TrrntZip, false);
}
ushort tshort = br.ReadUInt16();
if (tshort != _compressionMethod)
{
return(ZipReturn.ZipLocalFileHeaderError);
}
ushort lastModFileTime = br.ReadUInt16();
ushort lastModFileDate = br.ReadUInt16();
long tTime = CompressUtils.UtcTicksFromDosDateTime(lastModFileDate, lastModFileTime);
if (tTime != HeaderLastModified)
{
SetStatus(LocalFileStatus.DateTimeMisMatch);
SetStatus(LocalFileStatus.TrrntZip, false);
}
LocalFile localHeader = new();
localHeader.CRC = ReadCRC(br);
ulong localHeaderCompressedSize = br.ReadUInt32();
localHeader.UncompressedSize = br.ReadUInt32();
ulong localRelativeOffset = 0;
ushort fileNameLength = br.ReadUInt16();
ushort extraFieldLength = br.ReadUInt16();
byte[] bFileName = br.ReadBytes(fileNameLength);
localHeader.Filename = (generalPurposeBitFlagLocal & (1 << 11)) == 0
? CompressUtils.GetString(bFileName)
: Encoding.UTF8.GetString(bFileName, 0, fileNameLength);
if (extraFieldLength > 0)
{
byte[] extraField = br.ReadBytes(extraFieldLength);
ZipReturn zr = ZipExtraField.ReadExtraField(extraField, bFileName, localHeader, ref localHeaderCompressedSize, ref localRelativeOffset, false);
if (zr != ZipReturn.ZipGood)
{
return(zr);
}
}
if (!CompressUtils.CompareString(Filename, localHeader.Filename))
{
SetStatus(LocalFileStatus.TrrntZip, false);
if (!CompressUtils.CompareStringSlash(Filename.ToLower(), localHeader.Filename.ToLower()))
{
SetStatus(LocalFileStatus.FilenameMisMatch);
}
}
_dataLocation = (ulong)zipFs.Position;
if ((GeneralPurposeBitFlag & 8) == 8)
{
SetStatus(LocalFileStatus.TrrntZip, false);
zipFs.Position += (long)_compressedSize;
localHeader.CRC = ReadCRC(br);
if (CompressUtils.ByteArrCompare(localHeader.CRC, new byte[] { 0x08, 0x07, 0x4b, 0x50 }))
{
localHeader.CRC = ReadCRC(br);
}
if (GetStatus(LocalFileStatus.Zip64))
{
localHeaderCompressedSize = br.ReadUInt64();
localHeader.UncompressedSize = br.ReadUInt64();
}
else
{
localHeaderCompressedSize = br.ReadUInt32();
localHeader.UncompressedSize = br.ReadUInt32();
}
}
if (CompressUtils.IsCodePage437(Filename) != ((GeneralPurposeBitFlag & (1 << 11)) == 0))
{
SetStatus(LocalFileStatus.TrrntZip, false);
}
if (!CompressUtils.ByteArrCompare(localHeader.CRC, CRC))
{
return(ZipReturn.ZipLocalFileHeaderError);
}
if (localHeaderCompressedSize != _compressedSize)
{
return(ZipReturn.ZipLocalFileHeaderError);
}
if (localHeader.UncompressedSize != UncompressedSize)
{
return(ZipReturn.ZipLocalFileHeaderError);
}
return(ZipReturn.ZipGood);
}
}
catch
{
return(ZipReturn.ZipLocalFileHeaderError);
}
}