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Correctly (I hope) implement reading from the central directory

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This commit is contained in:
Michael Becker 2016-02-04 15:22:37 -05:00
parent bed9717b24
commit 019f9a88d4
1 changed files with 149 additions and 4 deletions
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153
CSharp/Plugins/UniversalEditor.Plugins.FileSystem/DataFormats/FileSystem/ZIP/ZIPDataFormat.cs
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@ -19,6 +19,9 @@ namespace UniversalEditor.DataFormats.FileSystem.ZIP
{
private ZIPSettings mvarSettings = new ZIPSettings();
private static readonly byte[] SIG_CENTRAL_DIRECTORY_ENTRY = new byte[] { 0x50, 0x4B, 0x01, 0x02 };
private static readonly byte[] SIG_END_OF_CENTRAL_DIRECTORY = new byte[] { 0x50, 0x4B, 0x05, 0x06 };
private string mvarComment = String.Empty;
public string Comment { get { return mvarComment; } set { mvarComment = value; } }
@ -37,6 +40,120 @@ namespace UniversalEditor.DataFormats.FileSystem.ZIP
if (fsom == null) return;
IO.Reader br = base.Accessor.Reader;
long eocdOffset = zip_FindEndOfCentralDirectory(br);
if (eocdOffset != -1)
{
// let's work with the central directory since it's more reliable than the file header
Internal.ZIPCentralDirectoryFooter footer = ReadZIPCentralDirectoryFooter(br);
if (footer.centralDirectoryOffset > 0 && footer.centralDirectoryOffset < br.Accessor.Length)
{
br.Seek(footer.centralDirectoryOffset, SeekOrigin.Begin);
long pos = br.Accessor.Position;
while (br.Accessor.Position < footer.centralDirectoryLength + pos)
{
byte[] centralDirectorySignature = br.ReadBytes(4);
if (!centralDirectorySignature.Match(SIG_CENTRAL_DIRECTORY_ENTRY))
{
Console.WriteLine("zip: @" + br.Accessor.Position.ToString() + " - invalid central directory entry, shit might get real now");
}
ushort unknown1 = br.ReadUInt16();
ushort unknown2 = br.ReadUInt16();
ushort unknown3 = br.ReadUInt16();
ushort unknown4 = br.ReadUInt16();
uint unknown5 = br.ReadUInt32();
uint unknown6 = br.ReadUInt32();
uint compressedLength = br.ReadUInt32();
uint decompressedLength = br.ReadUInt32();
uint fileNameLength = br.ReadUInt32();
ushort unknown7 = br.ReadUInt16();
ushort unknown8 = br.ReadUInt16();
ushort unknown9 = br.ReadUInt16();
ushort unknown10 = br.ReadUInt16();
ushort unknown11 = br.ReadUInt16();
uint fileOffset = br.ReadUInt32();
string fileName = br.ReadFixedLengthString(fileNameLength);
long curpos = br.Accessor.Position;
br.Accessor.Position = fileOffset;
byte[] headerSignature = br.ReadBytes(4);
if (!headerSignature.Match(new byte[] { 0x50, 0x4B, 0x03, 0x04 }))
{
}
CompressionMethod method = CompressionMethod.None;
short iMinimumVersionNeededToExtract = br.ReadInt16();
short iGeneralPurposeBitFlag = br.ReadInt16();
short iCompressionMethod = br.ReadInt16();
switch (iCompressionMethod)
{
case 8:
{
method = CompressionMethod.Deflate;
break;
}
case 9:
{
method = CompressionMethod.Deflate64;
break;
}
case 12:
{
method = CompressionMethod.Bzip2;
break;
}
case 14:
{
method = CompressionMethod.LZMA;
break;
}
}
short iFileLastModificationTime = br.ReadInt16();
short iFileLastModificationDate = br.ReadInt16();
bool isEncrypted = false;
int iCRC32 = br.ReadInt32();
int packedFileLength = br.ReadInt32();
int unpackedFileLength = br.ReadInt32();
short local_fileNameLength = br.ReadInt16();
short extraFieldLength = br.ReadInt16();
string local_fileName = br.ReadFixedLengthString(fileNameLength);
long local_pos = br.Accessor.Position;
while (br.Accessor.Position < (local_pos + extraFieldLength))
{
short chunkIDCode = br.ReadInt16();
short chunkLength = br.ReadInt16();
byte[] data = br.ReadBytes(chunkLength);
}
byte[] compressedData = br.ReadBytes(compressedLength);
br.Accessor.Position = curpos;
byte[] decompressedData = compressedData;
if (compressedLength != decompressedLength)
{
decompressedData = UniversalEditor.Compression.CompressionModules.Deflate.Decompress(compressedData);
if (decompressedData.Length != decompressedLength)
{
Console.WriteLine("zip: sanity check - decompressed data length (" + decompressedData.Length.ToString() + ") does not match expected value (" + decompressedLength.ToString() + ")");
}
}
File file = fsom.AddFile(fileName, decompressedData);
}
return;
}
else
{
Console.WriteLine("zip: central directory offset " + footer.centralDirectoryOffset.ToString() + " out of bounds for file (" + br.Accessor.Length.ToString() + ")");
}
}
int firstFile = this.zip_FindFirstFileOffset(br);
if (firstFile == -1)
{
@ -49,7 +166,8 @@ namespace UniversalEditor.DataFormats.FileSystem.ZIP
File file = null;
try
{
file = (zip_ReadFile(br) as File);
zip_ReadFile(br, fsom);
/*
if (file != null)
{
if (file.Name.Contains("/"))
@ -106,6 +224,7 @@ namespace UniversalEditor.DataFormats.FileSystem.ZIP
{
break;
}
*/
}
catch (System.Security.SecurityException)
{
@ -114,6 +233,18 @@ namespace UniversalEditor.DataFormats.FileSystem.ZIP
}
}
private static Internal.ZIPCentralDirectoryFooter ReadZIPCentralDirectoryFooter(Reader reader)
{
Internal.ZIPCentralDirectoryFooter item = new Internal.ZIPCentralDirectoryFooter();
item.unknown1 = reader.ReadUInt32();
item.unknown2 = reader.ReadUInt16();
item.unknown3 = reader.ReadUInt16();
item.centralDirectoryLength = reader.ReadUInt32();
item.centralDirectoryOffset = reader.ReadUInt32();
item.unknown4 = reader.ReadUInt16();
return item;
}
private bool readCentralDirectory(IO.Reader br)
{
int ctdir = this.seekCentralDirectory(br);
@ -373,8 +504,23 @@ namespace UniversalEditor.DataFormats.FileSystem.ZIP
}
return -1;
}
private long zip_FindEndOfCentralDirectory(IO.Reader reader)
{
reader.Seek(-4, SeekOrigin.End);
while (true)
{
byte[] test = reader.ReadBytes(4);
if (test.Match(SIG_END_OF_CENTRAL_DIRECTORY))
{
return reader.Accessor.Position;
}
reader.Seek(-5, SeekOrigin.Current);
}
return -1;
}
private File zip_ReadFile(IO.Reader br)
private File zip_ReadFile(IO.Reader br, IFileSystemContainer fsom)
{
byte[] unpackedData;
CompressionMethod method = CompressionMethod.Deflate;
@ -446,9 +592,8 @@ namespace UniversalEditor.DataFormats.FileSystem.ZIP
HostApplication.Messages.Add(HostApplicationMessageSeverity.Error, "File size mismatch, source archive may be corrupted", fileName);
}
File f = new File();
File f = fsom.AddFile(fileName);
f.SetData(unpackedData);
f.Name = fileName;
return f;
}