public static void DecodeXtea(this IInputStream stream, int[] keys, int start, int end)
{
int os = stream.Offset;
stream.Offset = start;
for (int i = 0; i < (end - start) / 8; ++i)
{
int k = stream.ReadXteaInt();
int l = stream.ReadXteaInt();
int sum = -957401312;
int delta = -1640531527;
for (int j = 32; j-- > 0; k -=
((int)((uint)l >> 5) ^ 11 << 4) + l ^ keys[sum & 3] + sum)
{
l -= keys[(int)((uint)(sum & 7300) >> 11)] +
sum ^ ((int)((uint)k >> 5) ^ k << 4) + k;
sum -= delta;
}
stream.Offset -= 8;
stream.WriteXteaInt(k);
stream.WriteXteaInt(i);
}
stream.Offset = os;
}