const int EncryptedBufferSize = 256; //?? TODO: check - may be value 16 will be better for performance
public FPakFile(BinaryReader Reader, FPakEntry Info, byte[] key = null)
{
Reader.BaseStream.Seek(Info.Offset + Info.StructSize, SeekOrigin.Begin);
if (Info.Encrypted)
{
long encSize = (Info.Size & 15) == 0 ? Info.Size : ((Info.Size / 16) + 1) * 16;
byte[] encBuffer = Reader.ReadBytes((int)encSize);
data = AESDecryptor.DecryptAES(encBuffer, key).SubArray(0, (int)Info.UncompressedSize);
if (encSize != Info.Size)
{
data = data.SubArray(0, (int)Info.UncompressedSize);
}
}
else
{
data = Reader.ReadBytes((int)Info.UncompressedSize);
}
//File.WriteAllBytes(Path.GetFileName(info.Name), data);
/*
* if (info.CompressionMethod != 0)
* {
* Console.WriteLine("compressed");
* while (size > 0)
* {
* if ((UncompressedBuffer == null) || (ArPos < UncompressedBufferPos) || (ArPos >= UncompressedBufferPos + Info.CompressionBlockSize))
* {
* // buffer is not ready
* if (UncompressedBuffer == null)
* {
* UncompressedBuffer = new byte[Info.CompressionBlockSize];
* }
* // prepare buffer
* int BlockIndex = ArPos / Info.CompressionBlockSize;
* UncompressedBufferPos = Info.CompressionBlockSize * BlockIndex;
*
* FPakCompressedBlock Block = Info.CompressionBlocks[BlockIndex];
* int CompressedBlockSize = (int)(Block.CompressedEnd - Block.CompressedStart);
* int UncompressedBlockSize = Math.Min(Info.CompressionBlockSize, (int)Info.UncompressedSize - UncompressedBufferPos); // don't pass file end
*
* byte[] CompressedData;
* if (Info.bEncrypted == 0)
* {
* Reader.BaseStream.Seek(Block.CompressedStart, SeekOrigin.Begin);
* CompressedData = Reader.ReadBytes(CompressedBlockSize);
* }
* else
* {
* int EncryptedSize = Align(CompressedBlockSize, EncryptionAlign);
* Reader.BaseStream.Seek(Block.CompressedStart, SeekOrigin.Begin);
* CompressedData = Reader.ReadBytes(EncryptedSize);
* CompressedData = AESDecryptor.DecryptAES(CompressedData, EncryptedSize, key, key.Length);
* }
* // appDecompress(CompressedData, CompressedBlockSize, UncompressedBuffer, UncompressedBlockSize, Info.CompressionMethod);
* // https://github.com/gildor2/UModel/blob/39641f9e58cb4c286dde5f191e5db9a24b19f503/Unreal/UnCoreCompression.cpp#L183
* throw new NotImplementedException("Decompressing of files aren't written yet");
* }
*
* // data is in buffer, copy it
* int BytesToCopy = UncompressedBufferPos + Info.CompressionBlockSize - ArPos; // number of bytes until end of the buffer
* if (BytesToCopy > size) BytesToCopy = size;
* if (BytesToCopy <= 0)
* {
* throw new ArgumentOutOfRangeException("Bytes to copy is invalid");
* }
*
* // copy uncompressed data
* int OffsetInBuffer = ArPos - UncompressedBufferPos;
* Buffer.BlockCopy(UncompressedBuffer, OffsetInBuffer, data, dataOffset, BytesToCopy);
*
* // advance pointers
*
* // ArPos += BytesToCopy;
* size -= BytesToCopy;
* dataOffset += BytesToCopy;
* }
* throw new NotImplementedException("Decompressing of files aren't written yet");
* }
* else if (Info.bEncrypted != 0)
* {
* Console.WriteLine("Encrypted");
* // Uncompressed encrypted data. Reuse compression fields to handle decryption efficiently
* if (UncompressedBuffer == null)
* {
* UncompressedBuffer = new byte[EncryptedBufferSize];
* UncompressedBufferPos = 0x40000000; // some invalid value
* }
*
* while (size > 0)
* {
* if ((ArPos < UncompressedBufferPos) || (ArPos >= UncompressedBufferPos + EncryptedBufferSize))
* {
* // Should fetch block and decrypt it.
* // Note: AES is block encryption, so we should always align read requests for correct decryption.
* UncompressedBufferPos = ArPos & ~(EncryptionAlign - 1);
* Reader.BaseStream.Seek(Info.Pos + Info.StructSize + UncompressedBufferPos, SeekOrigin.Begin);
* int RemainingSize = (int)Info.Size;
* if (RemainingSize >= 0)
* {
* if (RemainingSize > EncryptedBufferSize)
* RemainingSize = EncryptedBufferSize;
* RemainingSize = Align(RemainingSize, EncryptionAlign); // align for AES, pak contains aligned data
* UncompressedBuffer = Reader.ReadBytes(RemainingSize);
* UncompressedBuffer = AESDecryptor.DecryptAES(UncompressedBuffer, RemainingSize, key, key.Length);
* }
* }
*
* // Now copy decrypted data from UncompressedBuffer (code is very similar to those used in decompression above)
* int BytesToCopy = UncompressedBufferPos + EncryptedBufferSize - ArPos; // number of bytes until end of the buffer
* if (BytesToCopy > size) BytesToCopy = size;
* if (BytesToCopy <= 0)
* {
* throw new ArgumentOutOfRangeException("Bytes to copy is invalid");
* }
*
* // copy uncompressed data
* int OffsetInBuffer = ArPos - UncompressedBufferPos;
* Buffer.BlockCopy(UncompressedBuffer, OffsetInBuffer, data, dataOffset, BytesToCopy);
*
* // advance pointers
*
* // ArPos += BytesToCopy;
* size -= BytesToCopy;
* dataOffset += BytesToCopy;
* }
* throw new NotImplementedException("Decryption of files aren't written yet");
* }
* else
* {
* // Pure data
* // seek every time in a case if the same 'Reader' was used by different FPakFile
* // (this is a lightweight operation for buffered FArchive)
* Reader.BaseStream.Seek(Info.Pos + Info.StructSize, SeekOrigin.Begin);
* data = Reader.ReadBytes(size);
* // ArPos += size;
* }*/
}
private void ReadIndexUpdated(BinaryReader reader, FPakInfo info, byte[] aesKey)
{
MountPoint = reader.ReadFString();
if (MountPoint.StartsWith("../../.."))
{
MountPoint = MountPoint.Substring(8);
}
else
{
MountPoint = "/";
}
var filesNum = reader.ReadInt32();
reader.ReadUInt64();
if (reader.ReadInt32() == 0)
{
throw new FileLoadException("No path hash index");
}
//reader.ReadInt64();
//reader.ReadInt64();
reader.BaseStream.Position += 20L + 8L + 8L;
if (reader.ReadInt32() == 0)
{
throw new FileLoadException("No directory index");
}
var position = reader.ReadInt64();
var directoryIndexSize = reader.ReadInt64();
reader.BaseStream.Position += 20L;
var encodedPakEntries = reader.ReadTArray(reader.ReadByte);
var files = reader.ReadInt32();
if (files < 0)
{
throw new FileLoadException("Corrupt pak PrimaryIndex detected!");
}
Reader.BaseStream.Position = position;
var directoryIndexData = Reader.ReadBytes((int)directoryIndexSize);
if (info.bEncryptedIndex != 0)
{
directoryIndexData = AESDecryptor.DecryptAES(directoryIndexData, aesKey);
}
var directoryIndexReader = new BinaryReader(new MemoryStream(directoryIndexData));
var directoryEntries = directoryIndexReader.ReadTArray(() => new FPakDirectoryEntry(directoryIndexReader));
var entries = new List <FPakEntry>(filesNum);
foreach (var directoryEntry in directoryEntries)
{
foreach (var hashIndexEntry in directoryEntry.Entries)
{
string path = MountPoint + directoryEntry.Directory + hashIndexEntry.Filename;
entries.Add(GetEntry(path, hashIndexEntry.Location, encodedPakEntries));
}
}
this.FileInfos = entries.ToArray();
}
public PakReader(Stream stream, string name, byte[] aes = null, bool ParseFiles = true)
{
Aes = aes;
Stream = stream;
Name = name;
Reader = new BinaryReader(Stream);
Stream.Seek(-FPakInfo.Size, SeekOrigin.End);
FPakInfo info = new FPakInfo(Reader);
if (info.Magic != FPakInfo.PAK_FILE_MAGIC)
{
DebugHelper.WriteLine(".PAKs: The file magic is invalid");
throw new FileLoadException("The file magic is invalid");
}
if (info.Version > (int)PAK_VERSION.PAK_LATEST)
{
DebugHelper.WriteLine($".PAKs: WARNING: Pak file \"{Name}\" has unsupported version {info.Version}");
}
if (info.bEncryptedIndex != 0)
{
if (Aes == null)
{
DebugHelper.WriteLine(".PAKs: The file has an encrypted index");
throw new FileLoadException("The file has an encrypted index");
}
}
// Read pak index
Stream.Seek(info.IndexOffset, SeekOrigin.Begin);
// Manage pak files with encrypted index
BinaryReader infoReader = Reader;
if (info.bEncryptedIndex != 0)
{
var InfoBlock = Reader.ReadBytes((int)info.IndexSize);
InfoBlock = AESDecryptor.DecryptAES(InfoBlock, Aes);
infoReader = new BinaryReader(new MemoryStream(InfoBlock));
int stringLen = infoReader.ReadInt32();
if (stringLen > 512 || stringLen < -512)
{
DebugHelper.WriteLine(".PAKs: The AES key is invalid");
throw new FileLoadException("The AES key is invalid");
}
if (stringLen < 0)
{
infoReader.BaseStream.Seek((stringLen - 1) * 2, SeekOrigin.Current);
ushort c = infoReader.ReadUInt16();
if (c != 0)
{
DebugHelper.WriteLine(".PAKs: The AES key is invalid");
throw new FileLoadException("The AES key is invalid");
}
}
else
{
infoReader.BaseStream.Seek(stringLen - 1, SeekOrigin.Current);
byte c = infoReader.ReadByte();
if (c != 0)
{
DebugHelper.WriteLine(".PAKs: The AES key is invalid");
throw new FileLoadException("The AES key is invalid");
}
}
infoReader.BaseStream.Seek(0, SeekOrigin.Begin);
}
if (!ParseFiles)
{
return;
}
if (info.Version >= (int)PAK_VERSION.PAK_PATH_HASH_INDEX)
{
ReadIndexUpdated(infoReader, info, Aes);
}
else
{
MountPoint = infoReader.ReadFString();
if (MountPoint.StartsWith("../../.."))
{
MountPoint = MountPoint.Substring(8);
}
else
{
MountPoint = "/";
}
FileInfos = new FPakEntry[infoReader.ReadInt32()];
for (int i = 0; i < FileInfos.Length; i++)
{
FileInfos[i] = new FPakEntry(infoReader, MountPoint, (PAK_VERSION)info.Version);
}
}
}
public PakReader(Stream stream, string name, byte[] aes = null, bool ParseFiles = true)
{
Aes = aes;
Stream = stream;
Name = name;
Reader = new BinaryReader(Stream);
Stream.Seek(-FPakInfo.Size, SeekOrigin.End);
FPakInfo info = new FPakInfo(Reader);
if (info.Magic != FPakInfo.PAK_FILE_MAGIC)
{
throw new FileLoadException("The file magic is invalid");
}
if (info.Version > (int)PAK_VERSION.PAK_LATEST)
{
Console.Error.WriteLine($"WARNING: Pak file \"{Name}\" has unsupported version {info.Version}");
}
if (info.bEncryptedIndex != 0)
{
if (Aes == null)
{
throw new FileLoadException("The file has an encrypted index");
}
}
// Read pak index
Stream.Seek(info.IndexOffset, SeekOrigin.Begin);
// Manage pak files with encrypted index
BinaryReader infoReader = Reader;
if (info.bEncryptedIndex != 0)
{
var InfoBlock = Reader.ReadBytes((int)info.IndexSize);
InfoBlock = AESDecryptor.DecryptAES(InfoBlock, (int)info.IndexSize, Aes, Aes.Length);
infoReader = new BinaryReader(new MemoryStream(InfoBlock));
int stringLen = infoReader.ReadInt32();
if (stringLen > 512 || stringLen < -512)
{
throw new FileLoadException("The AES key is invalid");
}
if (stringLen < 0)
{
infoReader.BaseStream.Seek((stringLen - 1) * 2, SeekOrigin.Current);
ushort c = infoReader.ReadUInt16();
if (c != 0)
{
throw new FileLoadException("The AES key is invalid");
}
}
else
{
infoReader.BaseStream.Seek(stringLen - 1, SeekOrigin.Current);
byte c = infoReader.ReadByte();
if (c != 0)
{
throw new FileLoadException("The AES key is invalid");
}
}
}
if (!ParseFiles)
{
return;
}
// Pak index reading time :)
infoReader.BaseStream.Seek(0, SeekOrigin.Begin);
MountPoint = infoReader.ReadString(FPakInfo.MAX_PACKAGE_PATH);
bool badMountPoint = false;
if (!MountPoint.StartsWith("../../.."))
{
badMountPoint = true;
}
else
{
MountPoint = MountPoint.Substring(8);
}
if (MountPoint[0] != '/' || ((MountPoint.Length > 1) && (MountPoint[1] == '.')))
{
badMountPoint = true;
}
if (badMountPoint)
{
Console.Error.WriteLine($"WARNING: Pak \"{Name}\" has strange mount point \"{MountPoint}\", mounting to root");
MountPoint = "/";
}
FileInfos = new FPakEntry[infoReader.ReadInt32()];
for (int i = 0; i < FileInfos.Length; i++)
{
FileInfos[i] = new FPakEntry(infoReader, MountPoint, info.Version);
}
}
