private void GetBodyKey()
{
BodyKey = new byte[0x10];
_headerStream.Position = 0;
_headerStream.Read(BodyKey, 0, 0x10);
}
public override int Read(byte[] buffer, int offset, int count)
{
var read = 0;
//Unencrypted header from 0 to 0x30; Contains headerkey and magic
if (Position < 0x30)
{
_baseStream.Position = Position;
var size = Math.Min(count, 0x30 - (int)Position);
read += _baseStream.Read(buffer, read + offset, size);
Position += size;
}
//Encrypted header from 0x30 to 0x60; Contains bodykey and meta information like size
//Gets decrypted with BBCipher, headerkey and vkey
if (Position < 0x60 && read < count)
{
_headerStream.Position = Position - 0x30;
var size = Math.Min(count - read, 0x60 - (int)Position);
read += _headerStream.Read(buffer, read + offset, size);
Position += size;
}
//Unencrypted MAC data from 0x60 to 0x90; Contains 3 MACs, each validating data portion from 0 to {position of MAC}
//One MAC is 0x10 bytes long
if (Position < 0x90 && read < count)
{
_baseStream.Position = Position;
var size = Math.Min(count - read, 0x90 - (int)Position);
read += _baseStream.Read(buffer, read + offset, size);
Position += size;
}
//Encrypted file data from 0x90 to file end; Contains all file data
//Gets decrypted with BBCipher, bodykey and vkey
if (read < count)
{
_bodyStream.Position = Position - 0x90;
var size = Math.Min(count - read, _bodyStream.Length - Position);
read += _bodyStream.Read(buffer, read + offset, (int)size);
Position += size;
}
return(read);
}