internal static ECPoint ImplSumOfMultiplies(ECPoint[] ps, ECPointMap pointMap, BigInteger[] ks)
{
int halfCount = ps.Length, fullCount = halfCount << 1;
bool[] negs = new bool[fullCount];
WNafPreCompInfo[] infos = new WNafPreCompInfo[fullCount];
byte[][] wnafs = new byte[fullCount][];
for (int i = 0; i < halfCount; ++i)
{
int j0 = i << 1, j1 = j0 + 1;
BigInteger kj0 = ks[j0]; negs[j0] = kj0.SignValue < 0; kj0 = kj0.Abs();
BigInteger kj1 = ks[j1]; negs[j1] = kj1.SignValue < 0; kj1 = kj1.Abs();
int width = System.Math.Max(2, System.Math.Min(16, WNafUtilities.GetWindowSize(System.Math.Max(kj0.BitLength, kj1.BitLength))));
ECPoint P = ps[i], Q = WNafUtilities.MapPointWithPrecomp(P, width, true, pointMap);
infos[j0] = WNafUtilities.GetWNafPreCompInfo(P);
infos[j1] = WNafUtilities.GetWNafPreCompInfo(Q);
wnafs[j0] = WNafUtilities.GenerateWindowNaf(width, kj0);
wnafs[j1] = WNafUtilities.GenerateWindowNaf(width, kj1);
}
return ImplSumOfMultiplies(negs, infos, wnafs);
}
private static ECPoint ImplSumOfMultiplies(bool[] negs, WNafPreCompInfo[] infos, byte[][] wnafs)
{
int len = 0, count = wnafs.Length;
for (int i = 0; i < count; ++i)
{
len = System.Math.Max(len, wnafs[i].Length);
}
ECCurve curve = infos[0].PreComp[0].Curve;
ECPoint infinity = curve.Infinity;
ECPoint R = infinity;
int zeroes = 0;
for (int i = len - 1; i >= 0; --i)
{
ECPoint r = infinity;
for (int j = 0; j < count; ++j)
{
byte[] wnaf = wnafs[j];
int wi = i < wnaf.Length ? (int)(sbyte)wnaf[i] : 0;
if (wi != 0)
{
int n = System.Math.Abs(wi);
WNafPreCompInfo info = infos[j];
ECPoint[] table = (wi < 0 == negs[j]) ? info.PreComp : info.PreCompNeg;
r = r.Add(table[n >> 1]);
}
}
if (r == infinity)
{
++zeroes;
continue;
}
if (zeroes > 0)
{
R = R.TimesPow2(zeroes);
zeroes = 0;
}
R = R.TwicePlus(r);
}
if (zeroes > 0)
{
R = R.TimesPow2(zeroes);
}
return R;
}
internal static ECPoint ImplSumOfMultiplies(ECPoint[] ps, BigInteger[] ks)
{
int count = ps.Length;
bool[] negs = new bool[count];
WNafPreCompInfo[] infos = new WNafPreCompInfo[count];
byte[][] wnafs = new byte[count][];
for (int i = 0; i < count; ++i)
{
BigInteger ki = ks[i]; negs[i] = ki.SignValue < 0; ki = ki.Abs();
int width = System.Math.Max(2, System.Math.Min(16, WNafUtilities.GetWindowSize(ki.BitLength)));
infos[i] = WNafUtilities.Precompute(ps[i], width, true);
wnafs[i] = WNafUtilities.GenerateWindowNaf(width, ki);
}
return ImplSumOfMultiplies(negs, infos, wnafs);
}
