public static Scalar52 FromBytesWide(byte[] data)
{
ulong[] words = new ulong[8];
words.Initialize();
for (var i = 0; i < 8; i++)
{
for (var j = 0; j < 8; j++)
{
words[i] |= ((ulong)data[(i * 8) + j]) << (j * 8);
}
}
ulong mask = (1L << 52) - 1;
var lo = Scalar52.Zero();
var hi = Scalar52.Zero();
lo[0] = words[0] & mask;
lo[1] = ((words[0] >> 52) | (words[1] << 12)) & mask;
lo[2] = ((words[1] >> 40) | (words[2] << 24)) & mask;
lo[3] = ((words[2] >> 28) | (words[3] << 36)) & mask;
lo[4] = ((words[3] >> 16) | (words[4] << 48)) & mask;
hi[0] = (words[4] >> 4) & mask;
hi[1] = ((words[4] >> 56) | (words[5] << 8)) & mask;
hi[2] = ((words[5] >> 44) | (words[6] << 20)) & mask;
hi[3] = ((words[6] >> 32) | (words[7] << 32)) & mask;
hi[4] = words[7] >> 20;
lo = Scalar52.MontgomeryMul(lo, Consts.R); // (lo * R) / R = lo
hi = Scalar52.MontgomeryMul(hi, Consts.RR); // (hi * R^2) / R = hi * R
return(Scalar52.Add(hi, lo));
}
public static Scalar52 FromBytes(byte[] data)
{
ulong[] words = new ulong[4];
words.Initialize();
for (var i = 0; i < 4; i++)
{
for (var j = 0; j < 4; j++)
{
words[i] |= (ulong)data[(i * 8) + j] << (j * 8);
}
}
ulong mask = (1L << 52) - 1;
ulong topMask = (1L << 48) - 1;
var s = Scalar52.Zero();
s[0] = words[0] & mask;
s[1] = ((words[0] >> 52) | (words[1] << 12)) & mask;
s[2] = ((words[1] >> 40) | (words[2] << 24)) & mask;
s[3] = ((words[2] >> 28) | (words[3] << 36)) & mask;
s[4] = (words[3] >> 16) & topMask;
return(s);
}
public static Scalar Pack(Scalar52 scalar)
{
var sc = new Scalar {
ScalarBytes = scalar.ToBytes()
};
sc.Recalc();
return(sc);
}
