private byte[] GetSecondSubKey(byte[] key)
{
var firstSubKey = GetFirstSubKey(key);
var a = (byte)(firstSubKey[0] ^ 0b10000000);
var c = Aes16Helper.RotNib(firstSubKey[1]);
var b = Aes16Helper.SubNib(c);
var firstByte = (byte)(a ^ b);
var secondByte = (byte)(firstByte ^ firstSubKey[1]);
return(new[] { firstByte, secondByte });
}
private byte[] GetThirdSubKey(byte[] key)
{
var secondSubKey = GetSecondSubKey(key);
var firstByte = (byte)(secondSubKey[0] ^ 0b00110000 ^ Aes16Helper.SubNib(Aes16Helper.RotNib(secondSubKey[1])));
var secondByte = (byte)(firstByte ^ secondSubKey[1]);
return(new[] { firstByte, secondByte });
}