/// <summary>
/// Reads the PAK file metadata, including file list information and the file list
/// </summary>
/// <exception cref="NotSupportedException">Is thrown if the given PAK file does not have a valid signature</exception>
private void ReadMetadata()
{
using (BinaryReader reader = new BinaryReader(new MemoryStream(File.ReadAllBytes(FilePath))))
{
reader.BaseStream.Seek(-9L, SeekOrigin.End);
uint fileListOffset = reader.ReadUInt32();
uint fileCount = reader.ReadUInt32();
if ((reader.ReadByte()) != 0x12)
{
throw new NotSupportedException("The signature of this PAK file is invalid!");
}
reader.BaseStream.Seek(fileListOffset, SeekOrigin.Begin);
for (uint i = 0; i < fileCount; i++)
{
FileEntry fileEntry = new FileEntry();
fileEntry.FileNameLength = reader.ReadByte();
fileEntry.Compression = reader.ReadByte();
fileEntry.Offset = reader.ReadUInt32();
fileEntry.FileSize = reader.ReadUInt32();
fileEntry.RealFileSize = reader.ReadUInt32();
byte[] tempName = reader.ReadBytes(fileEntry.FileNameLength);
if (fileEntry.Compression < 4)
{
uint decryptionKey = (uint)Key;
reader.BaseStream.Seek(1L, SeekOrigin.Current);
fileEntry.FileName = Encoding.UTF8.GetString(XOR.Cipher(tempName, decryptionKey));
}
else
{
uint[] decryptionKey = (uint[])Key;
fileEntry.Compression ^= 0x20;
fileEntry.FileName = DecryptFileName(tempName, decryptionKey);
uint[] decryptionData =
{
fileEntry.Offset,
fileEntry.RealFileSize
};
uint[] resultData = XTEA.Decipher(16, decryptionData, decryptionKey);
fileEntry.Offset = resultData[0];
fileEntry.RealFileSize = resultData[1];
}
Entries.Add(fileEntry);
}
}
}
/// <summary>
/// Reads the file entries of the PAK file
/// </summary>
public void ReadFileEntries()
{
long Position = Reader.BaseStream.Position;
Reader.BaseStream.Seek(FileListOffset, SeekOrigin.Begin);
for (uint i = 0; i < FileCount; i++)
{
FileEntry fileEntry = new FileEntry();
fileEntry.FileNameLength = Reader.ReadByte();
fileEntry.Compression = Reader.ReadByte();
fileEntry.Offset = Reader.ReadUInt32();
fileEntry.FileSize = Reader.ReadUInt32();
fileEntry.RealFileSize = Reader.ReadUInt32();
byte[] tempName = Reader.ReadBytes(fileEntry.FileNameLength);
if (fileEntry.Compression < 4 && fileEntry.Compression > -1)
{
uint decryptionKey = (uint)Key;
fileEntry.Unknown1 = Reader.ReadByte();
fileEntry.FileName = Encoding.UTF8.GetString(XOR.Cipher(tempName, decryptionKey));
}
else
{
uint[] decryptionKey = (uint[])Key;
fileEntry.Compression ^= 0x20;
fileEntry.FileName = DecryptFileName(tempName, decryptionKey);
uint[] decryptionData = new uint[]
{
fileEntry.Offset,
fileEntry.RealFileSize
};
uint[] resultData = XTEA.Decipher(16, decryptionData, decryptionKey);
fileEntry.Offset = resultData[0];
fileEntry.RealFileSize = resultData[1];
}
Entries.Add(fileEntry);
}
Reader.BaseStream.Seek(Position, SeekOrigin.Begin);
}
