public static void Precompute()
{
if (precompBase != null)
{
return;
}
precompBase = new int[X25519Field.Size * 252];
int[] xs = precompBase;
int[] zs = new int[X25519Field.Size * 251];
int[] x = X25519Field.Create(); x[0] = 9;
int[] z = X25519Field.Create(); z[0] = 1;
int[] n = X25519Field.Create();
int[] d = X25519Field.Create();
X25519Field.Apm(x, z, n, d);
int[] c = X25519Field.Create(); X25519Field.Copy(d, 0, c, 0);
int off = 0;
for (;;)
{
X25519Field.Copy(n, 0, xs, off);
if (off == (X25519Field.Size * 251))
{
break;
}
PointDouble(x, z);
X25519Field.Apm(x, z, n, d);
X25519Field.Mul(n, c, n);
X25519Field.Mul(c, d, c);
X25519Field.Copy(d, 0, zs, off);
off += X25519Field.Size;
}
int[] u = X25519Field.Create();
X25519Field.Inv(c, u);
for (;;)
{
X25519Field.Copy(xs, off, x, 0);
X25519Field.Mul(x, u, x);
//X25519Field.Normalize(x);
X25519Field.Copy(x, 0, precompBase, off);
if (off == 0)
{
break;
}
off -= X25519Field.Size;
X25519Field.Copy(zs, off, z, 0);
X25519Field.Mul(u, z, u);
}
}
