public static void MultiplyAddToExt(uint[] x, uint[] y, uint[] zz)
{
Nat256.MulAddTo(x, y, zz);
if (Nat.Gte(16, zz, Curve25519Field.PExt))
{
Curve25519Field.SubPExtFrom(zz);
}
}
public static void MultiplyAddToExt(uint[] x, uint[] y, uint[] zz)
{
Nat256.MulAddTo(x, y, zz);
if (Nat.Gte(16, zz, PExt))
{
SubPExtFrom(zz);
}
}
public static void MultiplyAddToExt(uint[] x, uint[] y, uint[] zz)
{
uint c = Nat256.MulAddTo(x, y, zz);
if (c != 0 || (zz[15] >= PExt15 && Nat.Gte(16, zz, PExt)))
{
Nat.SubFrom(16, PExt, zz);
}
}
public static void MultiplyAddToExt(uint[] x, uint[] y, uint[] zz)
{
uint c = Nat256.MulAddTo(x, y, zz);
if (c != 0 || (zz[15] == PExt15 && Nat.Gte(16, zz, PExt)))
{
if (Nat.AddTo(PExtInv.Length, PExtInv, zz) != 0)
{
Nat.IncAt(16, zz, PExtInv.Length);
}
}
}
private static byte[] CalculateS(byte[] r, byte[] k, byte[] s)
{
uint[] t = new uint[ScalarUints * 2]; DecodeScalar(r, 0, t);
uint[] u = new uint[ScalarUints]; DecodeScalar(k, 0, u);
uint[] v = new uint[ScalarUints]; DecodeScalar(s, 0, v);
Nat256.MulAddTo(u, v, t);
byte[] result = new byte[ScalarBytes * 2];
for (int i = 0; i < t.Length; ++i)
{
Encode32(t[i], result, i * 4);
}
return(ReduceScalar(result));
}
