private static bool ReadHeader(ZipEntry ze, Encoding defaultEncoding)
{
// no seek - stream integrity should be protected by the caller
int bytesRead = 0;
ze._RelativeOffsetOfHeader = (int) ze.ArchiveStream.Position;
int signature = ZipSharedUtilities.ReadSignature(ze.ArchiveStream);
bytesRead += 4;
if (IsNotValidSig(signature))
{
ze.ArchiveStream.Seek(-4L, SeekOrigin.Current);
if (ZipDirEntry.IsNotValidSig(signature) && (signature != 0x6054b50L))
{
throw new BadReadException(String.Format(" ZipEntry::ReadHeader(): Bad signature (0x{0:X8}) at position 0x{1:X8}", signature, ze.ArchiveStream.Position));
}
return false;
}
byte[] block = new byte[0x1a];
int n = ze.ArchiveStream.Read(block, 0, block.Length);
if (n != block.Length)
{
return false;
}
bytesRead += n;
int i = 0;
ze._VersionNeeded = (short) (block[i++] + (block[i++] * 0x100));
ze._BitField = (short) (block[i++] + (block[i++] * 0x100));
ze._CompressionMethod = (short) (block[i++] + (block[i++] * 0x100));
ze._TimeBlob = ((block[i++] + (block[i++] * 0x100)) + ((block[i++] * 0x100) * 0x100)) + (((block[i++] * 0x100) * 0x100) * 0x100);
ze._LastModified = ZipSharedUtilities.PackedToDateTime(ze._TimeBlob);
if ((ze._BitField & 8) != 8)
{
ze._Crc32 = ((block[i++] + (block[i++] * 0x100)) + ((block[i++] * 0x100) * 0x100)) + (((block[i++] * 0x100) * 0x100) * 0x100);
ze._CompressedSize = ((block[i++] + (block[i++] * 0x100)) + ((block[i++] * 0x100) * 0x100)) + (((block[i++] * 0x100) * 0x100) * 0x100);
ze._UncompressedSize = ((block[i++] + (block[i++] * 0x100)) + ((block[i++] * 0x100) * 0x100)) + (((block[i++] * 0x100) * 0x100) * 0x100);
}
else
{
i += 12;
}
short filenameLength = (short) (block[i++] + (block[i++] * 0x100));
short extraFieldLength = (short) (block[i++] + (block[i++] * 0x100));
block = new byte[filenameLength];
n = ze.ArchiveStream.Read(block, 0, block.Length);
bytesRead += n;
var s1 = ZipSharedUtilities.StringFromBuffer(block, block.Length, Encoding.GetEncoding(1251));
var s2 = ZipSharedUtilities.StringFromBuffer(block, block.Length, Encoding.ASCII);
var s3 = ZipSharedUtilities.StringFromBuffer(block, block.Length, Encoding.UTF8);
var s4 = ZipSharedUtilities.StringFromBuffer(block, block.Length, Encoding.Default);
var s5 = ZipSharedUtilities.StringFromBuffer(block, block.Length, Encoding.GetEncoding(1252));
if ((ze._BitField & 0x800) == 0x800)
{
ze._FileNameInArchive = ZipSharedUtilities.StringFromBuffer(block, block.Length, Encoding.UTF8);
ze.UseUtf8Encoding = true;
}
else
{
ze._FileNameInArchive = ZipSharedUtilities.StringFromBuffer(block, block.Length, defaultEncoding);
ze._encoding = defaultEncoding;
}
ze._LocalFileName = ze._FileNameInArchive;
if (extraFieldLength > 0)
{
ze._Extra = new byte[extraFieldLength];
n = ze.ArchiveStream.Read(ze._Extra, 0, ze._Extra.Length);
bytesRead += n;
}
if (!ze.FileName.EndsWith("/") && ((ze._BitField & 8) == 8))
{
long posn = ze.ArchiveStream.Position;
bool wantMore = true;
long SizeOfDataRead = 0L;
int tries = 0;
while (wantMore)
{
tries++;
long d = ZipSharedUtilities.FindSignature(ze.ArchiveStream, 0x8074b50);
if (d == -1L)
{
return false;
}
SizeOfDataRead += d;
block = new byte[12];
n = ze.ArchiveStream.Read(block, 0, block.Length);
if (n != 12)
{
return false;
}
bytesRead += n;
i = 0;
ze._Crc32 = ((block[i++] + (block[i++] * 0x100)) + ((block[i++] * 0x100) * 0x100)) + (((block[i++] * 0x100) * 0x100) * 0x100);
ze._CompressedSize = ((block[i++] + (block[i++] * 0x100)) + ((block[i++] * 0x100) * 0x100)) + (((block[i++] * 0x100) * 0x100) * 0x100);
ze._UncompressedSize = ((block[i++] + (block[i++] * 0x100)) + ((block[i++] * 0x100) * 0x100)) + (((block[i++] * 0x100) * 0x100) * 0x100);
if (SizeOfDataRead != ze._CompressedSize)
{
ze.ArchiveStream.Seek(-12L, SeekOrigin.Current);
SizeOfDataRead += 4L;
}
}
ze.ArchiveStream.Seek(posn, SeekOrigin.Begin);
}
ze._CompressedFileDataSize = ze._CompressedSize;
if ((ze._BitField & 1) == 1)
{
throw new NotSupportedException("Encryption is not supported");
}
ze._TotalEntrySize = bytesRead + ze._CompressedFileDataSize;
ze._LengthOfHeader = bytesRead;
return true;
}
internal static ZipEntry Read(Stream s, Encoding defaultEncoding)
{
// no seek - stream integrity should be protected by the caller
ZipEntry entry = new ZipEntry
{
_Source = EntrySource.Zipfile,
_archiveStream = s
};
if (!ReadHeader(entry, defaultEncoding))
{
return null;
}
entry.__FileDataPosition = entry.ArchiveStream.Position;
s.Seek((long) entry._CompressedFileDataSize, SeekOrigin.Current);
if (!entry.FileName.EndsWith("/") && ((entry._BitField & 8) == 8))
{
s.Seek(0x10L, SeekOrigin.Current);
}
HandleUnexpectedDataDescriptor(entry);
return entry;
}
internal static ZipEntry Create(String filename, String nameInArchive, Stream stream)
{
if (String.IsNullOrEmpty(filename))
{
throw new ZipException("The entry name must be non-null and non-empty.");
}
ZipEntry entry = new ZipEntry();
if (stream != null)
{
entry._sourceStream = stream;
entry._LastModified = DateTime.Now;
}
else
{
entry._LastModified = (File.Exists(filename) || Directory.Exists(filename)) ? ZipSharedUtilities.RoundToEvenSecond(File.GetLastWriteTime(filename)) : DateTime.Now;
if (!(entry._LastModified.IsDaylightSavingTime() || !DateTime.Now.IsDaylightSavingTime()))
{
entry._LastModified += new TimeSpan(1, 0, 0);
}
if (!(!entry._LastModified.IsDaylightSavingTime() || DateTime.Now.IsDaylightSavingTime()))
{
entry._LastModified -= new TimeSpan(1, 0, 0);
}
}
entry._LocalFileName = filename;
entry._FileNameInArchive = nameInArchive.Replace('\\', '/');
return entry;
}
private static void HandleUnexpectedDataDescriptor(ZipEntry entry)
{
// no seek - stream integrity should be protected by the caller
Stream s = entry.ArchiveStream;
if (ZipSharedUtilities.ReadInt(s) == entry._Crc32)
{
if (ZipSharedUtilities.ReadInt(s) == entry._CompressedSize)
{
if (ZipSharedUtilities.ReadInt(s) != entry._UncompressedSize)
{
s.Seek(-12L, SeekOrigin.Current);
}
}
else
{
s.Seek(-8L, SeekOrigin.Current);
}
}
else
{
s.Seek(-4L, SeekOrigin.Current);
}
}
internal void CopyMetaData(ZipEntry source)
{
this.__FileDataPosition = source.__FileDataPosition;
this.CompressionMethod = source.CompressionMethod;
this._CompressedFileDataSize = source._CompressedFileDataSize;
this._UncompressedSize = source._UncompressedSize;
this._BitField = source._BitField;
this._LastModified = source._LastModified;
}