protected ZipHeader ReadHeader(uint headerBytes, BinaryReader reader)
{
switch (headerBytes)
{
case 0x5054b50:
return(null);
case 0x6054b50:
{
DirectoryEndHeader header3 = new DirectoryEndHeader();
header3.Read(reader);
return(header3);
}
case 0x2014b50:
{
DirectoryEntryHeader header2 = new DirectoryEntryHeader();
header2.Read(reader);
return(header2);
}
case 0x4034b50:
{
LocalEntryHeader entryHeader = new LocalEntryHeader();
entryHeader.Read(reader);
this.LoadHeader(entryHeader, reader.BaseStream);
this.lastEntryHeader = entryHeader;
return(entryHeader);
}
case 0x6064b50:
case 0x7064b50:
{
IgnoreHeader header4 = new IgnoreHeader(ZipHeaderType.Ignore);
header4.Read(reader);
return(header4);
}
case 0x8074b50:
if (FlagUtility.HasFlag <HeaderFlags>(this.lastEntryHeader.Flags, HeaderFlags.UsePostDataDescriptor))
{
this.lastEntryHeader.Crc = reader.ReadUInt32();
this.lastEntryHeader.CompressedSize = reader.ReadUInt32();
this.lastEntryHeader.UncompressedSize = reader.ReadUInt32();
}
else
{
reader.ReadUInt32();
reader.ReadUInt32();
reader.ReadUInt32();
}
return(null);
case 0x30304b50:
return(new SplitHeader());
}
throw new NotSupportedException("Unknown header: " + headerBytes);
}
internal IEnumerable <ZipHeader> ReadSeekableHeader(Stream stream)
{
var reader = new BinaryReader(stream);
SeekBackToHeader(stream, reader, DIRECTORY_END_HEADER_BYTES);
var entry = new DirectoryEndHeader();
entry.Read(reader);
if (entry.IsZip64)
{
_zip64 = true;
SeekBackToHeader(stream, reader, ZIP64_END_OF_CENTRAL_DIRECTORY_LOCATOR);
var zip64Locator = new Zip64DirectoryEndLocatorHeader();
zip64Locator.Read(reader);
stream.Seek(zip64Locator.RelativeOffsetOfTheEndOfDirectoryRecord, SeekOrigin.Begin);
uint zip64Signature = reader.ReadUInt32();
if (zip64Signature != ZIP64_END_OF_CENTRAL_DIRECTORY)
{
throw new ArchiveException("Failed to locate the Zip64 Header");
}
var zip64Entry = new Zip64DirectoryEndHeader();
zip64Entry.Read(reader);
stream.Seek(zip64Entry.DirectoryStartOffsetRelativeToDisk, SeekOrigin.Begin);
}
else
{
stream.Seek(entry.DirectoryStartOffsetRelativeToDisk, SeekOrigin.Begin);
}
long position = stream.Position;
while (true)
{
stream.Position = position;
uint signature = reader.ReadUInt32();
var nextHeader = ReadHeader(signature, reader, _zip64);
position = stream.Position;
if (nextHeader == null)
{
yield break;
}
if (nextHeader is DirectoryEntryHeader entryHeader)
{
//entry could be zero bytes so we need to know that.
entryHeader.HasData = entryHeader.CompressedSize != 0;
yield return(entryHeader);
}
else if (nextHeader is DirectoryEndHeader endHeader)
{
yield return(endHeader);
}
}
}
protected ZipHeader ReadHeader(uint headerBytes, BinaryReader reader)
{
switch (headerBytes)
{
case ENTRY_HEADER_BYTES:
{
var entryHeader = new LocalEntryHeader();
entryHeader.Read(reader);
LoadHeader(entryHeader, reader.BaseStream);
lastEntryHeader = entryHeader;
return(entryHeader);
}
case DIRECTORY_START_HEADER_BYTES:
{
var entry = new DirectoryEntryHeader();
entry.Read(reader);
return(entry);
}
case POST_DATA_DESCRIPTOR:
{
if (FlagUtility.HasFlag(lastEntryHeader.Flags, HeaderFlags.UsePostDataDescriptor))
{
lastEntryHeader.Crc = reader.ReadUInt32();
lastEntryHeader.CompressedSize = reader.ReadUInt32();
lastEntryHeader.UncompressedSize = reader.ReadUInt32();
}
else
{
reader.ReadUInt32();
reader.ReadUInt32();
reader.ReadUInt32();
}
return(null);
}
case DIGITAL_SIGNATURE:
return(null);
case DIRECTORY_END_HEADER_BYTES:
{
var entry = new DirectoryEndHeader();
entry.Read(reader);
return(entry);
}
case SPLIT_ARCHIVE_HEADER_BYTES:
{
return(new SplitHeader());
}
case ZIP64_END_OF_CENTRAL_DIRECTORY:
default:
throw new NotSupportedException("Unknown header: " + headerBytes);
}
}
internal static IEnumerable <ZipHeader> ReadHeaderNonseekable(Stream stream)
{
while (true)
{
ZipHeader header = null;
try
{
MarkingBinaryReader reader = new MarkingBinaryReader(stream);
uint headerBytes = reader.ReadUInt32();
switch (headerBytes)
{
case ENTRY_HEADER_BYTES:
{
var entry = new LocalEntryHeader();
entry.Read(reader);
if (entry.CompressedSize > 0)
{
entry.PackedStream = new ReadOnlySubStream(stream, entry.CompressedSize, true);
}
header = entry;
}
break;
case DIRECTORY_START_HEADER_BYTES:
{
var entry = new DirectoryEntryHeader();
entry.Read(reader);
header = entry;
}
break;
case POST_DATA_DESCRIPTOR:
case DIGITAL_SIGNATURE:
break;
case DIRECTORY_END_HEADER_BYTES:
{
var entry = new DirectoryEndHeader();
entry.Read(reader);
header = entry;
}
break;
case ZIP64_END_OF_CENTRAL_DIRECTORY:
default:
break;
}
}
catch
{
header = null;
}
yield return(header);
}
}
internal IEnumerable <DirectoryEntryHeader> ReadSeekableHeader(Stream stream)
{
long offset = 0;
uint signature;
BinaryReader reader = new BinaryReader(stream);
int iterationCount = 0;
do
{
if ((stream.Length + offset) - 4 < 0)
{
throw new ArchiveException("Failed to locate the Zip Header");
}
stream.Seek(offset - 4, SeekOrigin.End);
signature = reader.ReadUInt32();
offset--;
iterationCount++;
if (iterationCount > MAX_ITERATIONS_FOR_DIRECTORY_HEADER)
{
throw new ArchiveException(
"Could not find Zip file Directory at the end of the file. File may be corrupted.");
}
}while (signature != DIRECTORY_END_HEADER_BYTES);
var entry = new DirectoryEndHeader();
entry.Read(reader);
stream.Seek(entry.DirectoryStartOffsetRelativeToDisk, SeekOrigin.Begin);
DirectoryEntryHeader directoryEntryHeader = null;
long position = stream.Position;
while (true)
{
stream.Position = position;
signature = reader.ReadUInt32();
directoryEntryHeader = ReadHeader(signature, reader) as DirectoryEntryHeader;
position = stream.Position;
if (directoryEntryHeader == null)
{
yield break;
}
//entry could be zero bytes so we need to know that.
directoryEntryHeader.HasData = directoryEntryHeader.CompressedSize != 0;
yield return(directoryEntryHeader);
}
}
internal IEnumerable <DirectoryEntryHeader> ReadSeekableHeader(Stream stream)
{
uint iteratorVariable1;
long iteratorVariable0 = 0L;
BinaryReader reader = new BinaryReader(stream);
int iteratorVariable3 = 0;
do
{
if (((stream.Length + iteratorVariable0) - 4L) < 0L)
{
throw new ArchiveException("Failed to locate the Zip Header");
}
stream.Seek(iteratorVariable0 - 4L, SeekOrigin.End);
iteratorVariable1 = reader.ReadUInt32();
iteratorVariable0 -= 1L;
iteratorVariable3++;
if (iteratorVariable3 > 0x3e8)
{
throw new ArchiveException("Could not find Zip file Directory at the end of the file. File may be corrupted.");
}
}while (iteratorVariable1 != 0x6054b50);
DirectoryEndHeader iteratorVariable4 = new DirectoryEndHeader();
iteratorVariable4.Read(reader);
stream.Seek((long)iteratorVariable4.DirectoryStartOffsetRelativeToDisk, SeekOrigin.Begin);
DirectoryEntryHeader iteratorVariable5 = null;
long position = stream.Position;
while (true)
{
stream.Position = position;
iteratorVariable1 = reader.ReadUInt32();
iteratorVariable5 = this.ReadHeader(iteratorVariable1, reader) as DirectoryEntryHeader;
position = stream.Position;
if (iteratorVariable5 == null)
{
yield break;
}
iteratorVariable5.HasData = iteratorVariable5.CompressedSize != 0;
yield return(iteratorVariable5);
}
}
protected ZipHeader ReadHeader(uint headerBytes, BinaryReader reader, bool zip64 = false)
{
switch (headerBytes)
{
case ENTRY_HEADER_BYTES:
{
var entryHeader = new LocalEntryHeader(_archiveEncoding);
entryHeader.Read(reader);
LoadHeader(entryHeader, reader.BaseStream);
_lastEntryHeader = entryHeader;
return(entryHeader);
}
case DIRECTORY_START_HEADER_BYTES:
{
var entry = new DirectoryEntryHeader(_archiveEncoding);
entry.Read(reader);
return(entry);
}
case POST_DATA_DESCRIPTOR:
{
if (FlagUtility.HasFlag(_lastEntryHeader.Flags, HeaderFlags.UsePostDataDescriptor))
{
_lastEntryHeader.Crc = reader.ReadUInt32();
_lastEntryHeader.CompressedSize = zip64 ? (long)reader.ReadUInt64() : reader.ReadUInt32();
_lastEntryHeader.UncompressedSize = zip64 ? (long)reader.ReadUInt64() : reader.ReadUInt32();
}
else
{
reader.ReadBytes(zip64 ? 20 : 12);
}
return(null);
}
case DIGITAL_SIGNATURE:
return(null);
case DIRECTORY_END_HEADER_BYTES:
{
var entry = new DirectoryEndHeader();
entry.Read(reader);
return(entry);
}
case SPLIT_ARCHIVE_HEADER_BYTES:
{
return(new SplitHeader());
}
case ZIP64_END_OF_CENTRAL_DIRECTORY:
{
var entry = new Zip64DirectoryEndHeader();
entry.Read(reader);
return(entry);
}
case ZIP64_END_OF_CENTRAL_DIRECTORY_LOCATOR:
{
var entry = new Zip64DirectoryEndLocatorHeader();
entry.Read(reader);
return(entry);
}
default:
return(null);
}
}
