sign function
Implementation
List<int> sign(List<int> secret, List<int> message, {ED448_XOF xof = shake_256}) {
final expanded = _secretExpand(secret);
final a = expanded[0];
final prefix = expanded[1];
final A = _pointCompress(_pointMultiply(a, _G));
final r = _xofModQ(xof, MARKER + [0] + [0] + prefix + message, 114);
final R = _pointMultiply(r, _G);
final Rs = _pointCompress(R);
final h = _xofModQ(xof, MARKER + [0] + [0] + Rs + A + message, 114);
final s = (r + h * a) % q;
return UnmodifiableUint8ListView(Uint8List.fromList(Rs + _toLE(s, 57)));
}