private static uint GFExp7(uint b, uint m)
{
if (b == 0u)
{
return(0u);
}
uint x = IceCryptoTransform.GFMultiply(b, b, m);
x = IceCryptoTransform.GFMultiply(b, x, m);
x = IceCryptoTransform.GFMultiply(x, x, m);
return(IceCryptoTransform.GFMultiply(b, x, m));
}
private static void InitializeSBox()
{
if (IceCryptoTransform.SBox == null)
{
IceCryptoTransform.SBox = new uint[4, 1024];
for (int i = 0; i < 1024; i++)
{
int col = i >> 1 & 255;
int row = (i & 1) | (i & 512) >> 8;
IceCryptoTransform.SBox[0, i] = IceCryptoTransform.Perm32(IceCryptoTransform.GFExp7((uint)(col ^ IceCryptoTransform.SXor[0, row]), (uint)IceCryptoTransform.SMod[0, row]) << 24);
IceCryptoTransform.SBox[1, i] = IceCryptoTransform.Perm32(IceCryptoTransform.GFExp7((uint)(col ^ IceCryptoTransform.SXor[1, row]), (uint)IceCryptoTransform.SMod[1, row]) << 16);
IceCryptoTransform.SBox[2, i] = IceCryptoTransform.Perm32(IceCryptoTransform.GFExp7((uint)(col ^ IceCryptoTransform.SXor[2, row]), (uint)IceCryptoTransform.SMod[2, row]) << 8);
IceCryptoTransform.SBox[3, i] = IceCryptoTransform.Perm32(IceCryptoTransform.GFExp7((uint)(col ^ IceCryptoTransform.SXor[3, row]), (uint)IceCryptoTransform.SMod[3, row]));
}
}
}
internal IceCryptoTransform(int n, byte[] key, bool encrypt)
{
this.encrypt = encrypt;
IceCryptoTransform.InitializeSBox();
if (n == 0)
{
this.size = 1;
this.rounds = 8;
}
else
{
this.size = n;
this.rounds = n << 4;
}
this.keySchedule = new uint[this.rounds, 3];
this.SetKey(key);
}