public void TestClone()
{
var p = new CurvePoint(5, 5);
var q = p.Clone();
Assert.AreNotSame(p, q);
Assert.AreEqual(p, q);
}
public void TestAddDoublePoint()
{
var curve = TestCurveParameters.WeierstrassParameters.Equation;
var p = new CurvePoint(5, 5);
var other = p.Clone();
var expectedQ = new CurvePoint(15, 14);
var q = curve.Add(p, other);
Assert.AreEqual(expectedQ, q);
}
public void TestEquals()
{
var p = new CurvePoint(11, 0);
var q = new CurvePoint(3, 4);
Assert.AreEqual(p, p, "same");
Assert.AreEqual(p, p.Clone(), "equal");
Assert.AreEqual(CurvePoint.PointAtInfinity, CurvePoint.PointAtInfinity, "at inf");
Assert.AreNotEqual(p, q, "not equal");
Assert.AreNotEqual(q, p, "not equal reversed");
}
public void TestAreNegationsFalseForEqualPoint()
{
var equation = new Mock <CurveEquation>(
BigPrime.CreateWithoutChecks(23),
BigInteger.Zero, BigInteger.One
)
{
CallBase = true
};
var testElement = new CurvePoint(5, 5);
var otherElement = testElement.Clone();
Assert.IsFalse(equation.Object.AreNegations(testElement, otherElement));
}
/// <inheritdoc/>
public override CurvePoint Add(CurvePoint left, CurvePoint right)
{
BigInteger x1 = left.X;
BigInteger x2 = right.X;
BigInteger y1 = left.Y;
BigInteger y2 = right.Y;
BigInteger lambda;
if (left.Equals(right))
{
lambda = Field.Mod((3 * Field.Square(x1) + 2 * A * x1 + 1) * Field.InvertMult(2 * B * y1));
}
else
{
lambda = Field.Mod((y2 - y1) * Field.InvertMult(x2 - x1));
}
BigInteger x3 = Field.Mod(B * Field.Square(lambda) - x1 - x2 - A);
BigInteger y3 = Field.Mod(lambda * (x1 - x3) - y1);
CurvePoint result = CurvePoint.PointAtInfinity;
bool pointsAreNegations = AreNegations(left, right);
if (left.IsAtInfinity && right.IsAtInfinity)
{
result = CurvePoint.PointAtInfinity;
}
if (left.IsAtInfinity && !right.IsAtInfinity)
{
result = right.Clone();
}
if (right.IsAtInfinity && !left.IsAtInfinity)
{
result = left.Clone();
}
if (!left.IsAtInfinity && !right.IsAtInfinity && pointsAreNegations)
{
result = CurvePoint.PointAtInfinity;
}
if (!left.IsAtInfinity && !right.IsAtInfinity && !pointsAreNegations)
{
result = new CurvePoint(x3, y3);
}
return(result);
}