diff --git a/crypto/src/math/ec/ECPoint.cs b/crypto/src/math/ec/ECPoint.cs
index f8bbf04e7..cd6811dfa 100644
--- a/crypto/src/math/ec/ECPoint.cs
+++ b/crypto/src/math/ec/ECPoint.cs
@@ -289,6 +289,20 @@ namespace Org.BouncyCastle.Math.EC
get { return m_withCompression; }
}
+ public virtual ECPoint ScaleX(ECFieldElement scale)
+ {
+ return IsInfinity
+ ? this
+ : Curve.CreateRawPoint(RawXCoord.Multiply(scale), RawYCoord, RawZCoords, IsCompressed);
+ }
+
+ public virtual ECPoint ScaleY(ECFieldElement scale)
+ {
+ return IsInfinity
+ ? this
+ : Curve.CreateRawPoint(RawXCoord, RawYCoord.Multiply(scale), RawZCoords, IsCompressed);
+ }
+
public override bool Equals(object obj)
{
return Equals(obj as ECPoint);
@@ -1309,6 +1323,66 @@ namespace Org.BouncyCastle.Math.EC
}
}
+ public override ECPoint ScaleX(ECFieldElement scale)
+ {
+ if (this.IsInfinity)
+ return this;
+
+ switch (CurveCoordinateSystem)
+ {
+ case ECCurve.COORD_LAMBDA_AFFINE:
+ {
+ // Y is actually Lambda (X + Y/X) here
+ ECFieldElement X = RawXCoord, L = RawYCoord;
+
+ ECFieldElement X2 = X.Multiply(scale);
+ ECFieldElement L2 = L.Add(X).Divide(scale).Add(X2);
+
+ return Curve.CreateRawPoint(X, L2, RawZCoords, IsCompressed);
+ }
+ case ECCurve.COORD_LAMBDA_PROJECTIVE:
+ {
+ // Y is actually Lambda (X + Y/X) here
+ ECFieldElement X = RawXCoord, L = RawYCoord, Z = RawZCoords[0];
+
+ // We scale the Z coordinate also, to avoid an inversion
+ ECFieldElement X2 = X.Multiply(scale.Square());
+ ECFieldElement L2 = L.Add(X).Add(X2);
+ ECFieldElement Z2 = Z.Multiply(scale);
+
+ return Curve.CreateRawPoint(X, L2, new ECFieldElement[] { Z2 }, IsCompressed);
+ }
+ default:
+ {
+ return base.ScaleX(scale);
+ }
+ }
+ }
+
+ public override ECPoint ScaleY(ECFieldElement scale)
+ {
+ if (this.IsInfinity)
+ return this;
+
+ switch (CurveCoordinateSystem)
+ {
+ case ECCurve.COORD_LAMBDA_AFFINE:
+ case ECCurve.COORD_LAMBDA_PROJECTIVE:
+ {
+ ECFieldElement X = RawXCoord, L = RawYCoord;
+
+ // Y is actually Lambda (X + Y/X) here
+ ECFieldElement L2 = L.Add(X).Multiply(scale).Add(X);
+
+ return Curve.CreateRawPoint(X, L2, RawZCoords, IsCompressed);
+ }
+ default:
+ {
+ return base.ScaleY(scale);
+ }
+ }
+ }
+
protected internal override bool CompressionYTilde
{
get
|
