GeScalarMultVartime function Null safety

void GeScalarMultVartime(
  1. ProjectiveGroupElement r,
  2. Uint8List a,
  3. ExtendedGroupElement A
)

Implementation

void GeScalarMultVartime(
    ProjectiveGroupElement r, Uint8List a, ExtendedGroupElement A) {
  Int8List aSlide = new Int8List(256);
  var Ai = List.generate(8, (index) => CachedGroupElement()); // A,

  CompletedGroupElement t = new CompletedGroupElement();
  ExtendedGroupElement u = new ExtendedGroupElement();
  ExtendedGroupElement A2 = new ExtendedGroupElement();
  int i;

  slide(aSlide, a);

  A.ToCached(Ai[0]);
  A.Double(t);
  t.ToExtended(A2);

  for (i = 0; i < 7; i++) {
    geAdd(t, A2, Ai[i]);
    t.ToExtended(u);
    u.ToCached(Ai[i + 1]);
  }

  r.Zero();

  for (i = 255; i >= 0; i--) {
    if (aSlide[i] != 0) {
      break;
    }
  }

  for (; i >= 0; i--) {
    r.Double(t);

    if (aSlide[i] > 0) {
      t.ToExtended(u);
      geAdd(t, u, Ai[aSlide[i] ~/ 2]);
    } else if (aSlide[i] < 0) {
      t.ToExtended(u);
      geSub(t, u, Ai[(-aSlide[i]) ~/ 2]);
    }

    t.ToProjective(r);
  }

  ProjectiveGroupElement ProjBytesExt(ExtendedGroupElement r) {
    ProjectiveGroupElement p = new ProjectiveGroupElement();
    Uint8List buff = new Uint8List(32);

    p.ToBytes(buff);
    r.FromBytes(buff);

    return p;
  }
  // I AM FAILING TO ASSERT FromBytes()

  //var A2 edwards25519.ExtendedGroupElement
  //if ok := r.FromBytes(buff); !ok {
  //	return nil, errors.New("failed to create an extended group element A2 from A")
  //}
}