/// <param name="seedBytes"> - a bytes sequence of arbitrary length which will be hashed </param>
/// <param name="discriminator"> - nullable optional uint32 to hash </param>
/// <returns> a number between [1, order -1] suitable as a private key
/// </returns>
public static BigInteger ComputeScalar(byte[] seedBytes, uint?discriminator)
{
BigInteger key = null;
for (uint i = 0; i <= 0xFFFFFFFFL; i++)
{
var sha512 = new Sha512(seedBytes);
if (discriminator != null)
{
sha512.AddU32(discriminator.Value);
}
sha512.AddU32(i);
byte[] keyBytes = sha512.Finish256();
key = Misc.UBigInt(keyBytes);
if (key.CompareTo(BigInteger.Zero) == 1 &&
key.CompareTo(Secp256K1.Order()) == -1)
{
break;
}
}
return(key);
}