@Test
public void hashCodesAreEqualForEquivalentObjects() {
// Arrange:
final GroupElement g1 = MathUtils.getRandomGroupElement();
final GroupElement g2 = MathUtils.toRepresentation(g1, GroupElement.Representation.P2);
final GroupElement g3 = MathUtils.toRepresentation(g1, GroupElement.Representation.P1P1);
final GroupElement g4 = MathUtils.getRandomGroupElement();
// Assert
Assert.assertThat(g2.hashCode(), IsEqual.equalTo(g1.hashCode()));
Assert.assertThat(g3.hashCode(), IsEqual.equalTo(g1.hashCode()));
Assert.assertThat(g1.hashCode(), IsNot.not(IsEqual.equalTo(g4.hashCode())));
Assert.assertThat(g2.hashCode(), IsNot.not(IsEqual.equalTo(g4.hashCode())));
Assert.assertThat(g3.hashCode(), IsNot.not(IsEqual.equalTo(g4.hashCode())));
}
@Test
public void equalsOnlyReturnsTrueForEquivalentObjects() {
// Arrange:
final GroupElement g1 = MathUtils.getRandomGroupElement();
final GroupElement g2 = MathUtils.toRepresentation(g1, GroupElement.Representation.P2);
final GroupElement g3 = MathUtils.toRepresentation(g1, GroupElement.Representation.CACHED);
final GroupElement g4 = MathUtils.toRepresentation(g1, GroupElement.Representation.P1P1);
final GroupElement g5 = MathUtils.getRandomGroupElement();
// Assert
Assert.assertThat(g2, IsEqual.equalTo(g1));
Assert.assertThat(g3, IsEqual.equalTo(g1));
Assert.assertThat(g1, IsEqual.equalTo(g4));
Assert.assertThat(g1, IsNot.not(IsEqual.equalTo(g5)));
Assert.assertThat(g2, IsNot.not(IsEqual.equalTo(g5)));
Assert.assertThat(g3, IsNot.not(IsEqual.equalTo(g5)));
Assert.assertThat(g5, IsNot.not(IsEqual.equalTo(g4)));
}
@Test(expected = IllegalArgumentException.class)
public void toCachedThrowsIfGroupElementHasP1P1Representation() {
// Arrange:
final GroupElement g =
MathUtils.toRepresentation(
MathUtils.getRandomGroupElement(), GroupElement.Representation.P1P1);
// Assert:
g.toCached();
}
@Test(expected = IllegalArgumentException.class)
public void toP3ThrowsIfGroupElementHasPrecompRepresentation() {
// Arrange:
final GroupElement g =
MathUtils.toRepresentation(
MathUtils.getRandomGroupElement(), GroupElement.Representation.PRECOMP);
// Assert:
g.toP3();
}
@Test
public void toP3ReturnsExpectedResultIfGroupElementHasP1P1Representation() {
for (int i = 0; i < 10; i++) {
// Arrange:
final GroupElement g =
MathUtils.toRepresentation(
MathUtils.getRandomGroupElement(), GroupElement.Representation.P1P1);
// Act:
final GroupElement h1 = g.toP3();
final GroupElement h2 = MathUtils.toRepresentation(g, GroupElement.Representation.P3);
// Assert:
Assert.assertThat(h1, IsEqual.equalTo(h2));
Assert.assertThat(h1.getRepresentation(), IsEqual.equalTo(GroupElement.Representation.P3));
Assert.assertThat(h1.getX(), IsEqual.equalTo(g.getX().multiply(g.getT())));
Assert.assertThat(h1.getY(), IsEqual.equalTo(g.getY().multiply(g.getZ())));
Assert.assertThat(h1.getZ(), IsEqual.equalTo(g.getZ().multiply(g.getT())));
Assert.assertThat(h1.getT(), IsEqual.equalTo(g.getX().multiply(g.getY())));
}
}
@Test
public void dblPrecomputedTableContainsExpectedGroupElements() {
// Arrange:
GroupElement g = ed25519.getB();
GroupElement h = MathUtils.addGroupElements(g, g);
// Act + Assert:
for (int i = 0; i < 8; i++) {
Assert.assertThat(
MathUtils.toRepresentation(g, GroupElement.Representation.PRECOMP),
IsEqual.equalTo(ed25519.getB().dblPrecmp[i]));
g = MathUtils.addGroupElements(g, h);
}
}
@Test
public void precomputedTableContainsExpectedGroupElements() {
// Arrange:
GroupElement g = ed25519.getB();
// Act + Assert:
for (int i = 0; i < 32; i++) {
GroupElement h = g;
for (int j = 0; j < 8; j++) {
Assert.assertThat(
MathUtils.toRepresentation(h, GroupElement.Representation.PRECOMP),
IsEqual.equalTo(ed25519.getB().precmp[i][j]));
h = MathUtils.addGroupElements(h, g);
}
for (int k = 0; k < 8; k++) {
g = MathUtils.addGroupElements(g, g);
}
}
}
@Test
public void toP2ReturnsExpectedResultIfGroupElementHasP2Representation() {
for (int i = 0; i < 10; i++) {
// Arrange:
final GroupElement g =
MathUtils.toRepresentation(
MathUtils.getRandomGroupElement(), GroupElement.Representation.P2);
// Act:
final GroupElement h = g.toP2();
// Assert:
Assert.assertThat(h, IsEqual.equalTo(g));
Assert.assertThat(h.getRepresentation(), IsEqual.equalTo(GroupElement.Representation.P2));
Assert.assertThat(h.getX(), IsEqual.equalTo(g.getX()));
Assert.assertThat(h.getY(), IsEqual.equalTo(g.getY()));
Assert.assertThat(h.getZ(), IsEqual.equalTo(g.getZ()));
Assert.assertThat(h.getT(), IsEqual.equalTo(null));
}
}
@Test
public void toCachedReturnsExpectedResultIfGroupElementHasP3Representation() {
for (int i = 0; i < 10; i++) {
// Arrange:
final GroupElement g = MathUtils.getRandomGroupElement();
// Act:
final GroupElement h1 = g.toCached();
final GroupElement h2 = MathUtils.toRepresentation(g, GroupElement.Representation.CACHED);
// Assert:
Assert.assertThat(h1, IsEqual.equalTo(h2));
Assert.assertThat(
h1.getRepresentation(), IsEqual.equalTo(GroupElement.Representation.CACHED));
Assert.assertThat(h1, IsEqual.equalTo(g));
Assert.assertThat(h1.getX(), IsEqual.equalTo(g.getY().add(g.getX())));
Assert.assertThat(h1.getY(), IsEqual.equalTo(g.getY().subtract(g.getX())));
Assert.assertThat(h1.getZ(), IsEqual.equalTo(g.getZ()));
Assert.assertThat(h1.getT(), IsEqual.equalTo(g.getT().multiply(curve.get2D())));
}
}