public static ECPoint SumOfTwoMultiplies(ECPoint P, BigInteger a, ECPoint Q, BigInteger b)
{
ECCurve curve = P.Curve;
Q = ECAlgorithms.ImportPoint(curve, Q);
if (curve is F2mCurve)
{
F2mCurve f2mCurve = (F2mCurve)curve;
if (f2mCurve.IsKoblitz)
{
return(ECAlgorithms.ValidatePoint(P.Multiply(a).Add(Q.Multiply(b))));
}
}
GlvEndomorphism glvEndomorphism = curve.GetEndomorphism() as GlvEndomorphism;
if (glvEndomorphism != null)
{
return(ECAlgorithms.ValidatePoint(ECAlgorithms.ImplSumOfMultipliesGlv(new ECPoint[]
{
P,
Q
}, new BigInteger[]
{
a,
b
}, glvEndomorphism)));
}
return(ECAlgorithms.ValidatePoint(ECAlgorithms.ImplShamirsTrickWNaf(P, a, Q, b)));
}
internal static ECPoint ImplShamirsTrickWNaf(ECPoint P, BigInteger k, ECPointMap pointMapQ, BigInteger l)
{
bool flag = k.SignValue < 0;
bool flag2 = l.SignValue < 0;
k = k.Abs();
l = l.Abs();
int width = Math.Max(2, Math.Min(16, WNafUtilities.GetWindowSize(Math.Max(k.BitLength, l.BitLength))));
ECPoint p = WNafUtilities.MapPointWithPrecomp(P, width, true, pointMapQ);
WNafPreCompInfo wNafPreCompInfo = WNafUtilities.GetWNafPreCompInfo(P);
WNafPreCompInfo wNafPreCompInfo2 = WNafUtilities.GetWNafPreCompInfo(p);
ECPoint[] preCompP = flag ? wNafPreCompInfo.PreCompNeg : wNafPreCompInfo.PreComp;
ECPoint[] preCompQ = flag2 ? wNafPreCompInfo2.PreCompNeg : wNafPreCompInfo2.PreComp;
ECPoint[] preCompNegP = flag ? wNafPreCompInfo.PreComp : wNafPreCompInfo.PreCompNeg;
ECPoint[] preCompNegQ = flag2 ? wNafPreCompInfo2.PreComp : wNafPreCompInfo2.PreCompNeg;
byte[] wnafP = WNafUtilities.GenerateWindowNaf(width, k);
byte[] wnafQ = WNafUtilities.GenerateWindowNaf(width, l);
return(ECAlgorithms.ImplShamirsTrickWNaf(preCompP, preCompNegP, wnafP, preCompQ, preCompNegQ, wnafQ));
}
