using Org.BouncyCastle.Utilities; using System; namespace Org.BouncyCastle.Math.EC.Multiplier { public class WNafL2RMultiplier : AbstractECMultiplier { protected override ECPoint MultiplyPositive(ECPoint p, BigInteger k) { int windowSize = WNafUtilities.GetWindowSize(k.BitLength); WNafPreCompInfo wNafPreCompInfo = WNafUtilities.Precompute(p, windowSize, true); ECPoint[] preComp = wNafPreCompInfo.PreComp; ECPoint[] preCompNeg = wNafPreCompInfo.PreCompNeg; int width = wNafPreCompInfo.Width; int[] array = WNafUtilities.GenerateCompactWindowNaf(width, k); ECPoint eCPoint = p.Curve.Infinity; int num = array.Length; if (num > 1) { int num2 = array[--num]; int num3 = num2 >> 16; int num4 = num2 & 65535; int num5 = System.Math.Abs(num3); ECPoint[] array2 = (num3 < 0) ? preCompNeg : preComp; if (num5 << 2 < 1 << width) { int num6 = 32 - Integers.NumberOfLeadingZeros(num5); int num7 = width - num6; int num8 = num5 ^ (1 << num6 - 1); int num9 = (1 << width - 1) - 1; int num10 = (num8 << num7) + 1; eCPoint = array2[num9 >> 1].Add(array2[num10 >> 1]); num4 -= num7; } else eCPoint = array2[num5 >> 1]; eCPoint = eCPoint.TimesPow2(num4); } while (num > 0) { int num11 = array[--num]; int num12 = num11 >> 16; int e = num11 & 65535; int num13 = System.Math.Abs(num12); ECPoint b = ((num12 < 0) ? preCompNeg : preComp)[num13 >> 1]; eCPoint = eCPoint.TwicePlus(b); eCPoint = eCPoint.TimesPow2(e); } return eCPoint; } } }