GlvMultiplier
using Renci.SshNet.Security.Org.BouncyCastle.Math.EC.Endo;
using System;
namespace Renci.SshNet.Security.Org.BouncyCastle.Math.EC.Multiplier
{
internal class GlvMultiplier : AbstractECMultiplier
{
protected readonly ECCurve curve;
protected readonly GlvEndomorphism glvEndomorphism;
public GlvMultiplier(ECCurve curve, GlvEndomorphism glvEndomorphism)
{
if (curve == null || curve.Order == null)
throw new ArgumentException("Need curve with known group order", "curve");
this.curve = curve;
this.glvEndomorphism = glvEndomorphism;
}
protected override ECPoint MultiplyPositive(ECPoint p, BigInteger k)
{
if (!curve.Equals(p.Curve))
throw new InvalidOperationException();
BigInteger order = p.Curve.Order;
BigInteger[] array = glvEndomorphism.DecomposeScalar(k.Mod(order));
BigInteger k2 = array[0];
BigInteger l = array[1];
ECPointMap pointMap = glvEndomorphism.PointMap;
if (glvEndomorphism.HasEfficientPointMap)
return ECAlgorithms.ImplShamirsTrickWNaf(p, k2, pointMap, l);
return ECAlgorithms.ImplShamirsTrickWNaf(p, k2, pointMap.Map(p), l);
}
}
}