diff options
Diffstat (limited to 'crypto/src/math/ec/multiplier/WNafL2RMultiplier.cs')
| -rw-r--r-- | crypto/src/math/ec/multiplier/WNafL2RMultiplier.cs | 25 |
1 files changed, 8 insertions, 17 deletions
diff --git a/crypto/src/math/ec/multiplier/WNafL2RMultiplier.cs b/crypto/src/math/ec/multiplier/WNafL2RMultiplier.cs index f671f6a5c..833bbb5ea 100644 --- a/crypto/src/math/ec/multiplier/WNafL2RMultiplier.cs +++ b/crypto/src/math/ec/multiplier/WNafL2RMultiplier.cs @@ -1,5 +1,7 @@ using System; +using Org.BouncyCastle.Utilities; + namespace Org.BouncyCastle.Math.EC.Multiplier { /** @@ -18,12 +20,12 @@ namespace Org.BouncyCastle.Math.EC.Multiplier */ protected override ECPoint MultiplyPositive(ECPoint p, BigInteger k) { - // Clamp the window width in the range [2, 16] - int width = System.Math.Max(2, System.Math.Min(16, GetWindowSize(k.BitLength))); + int minWidth = WNafUtilities.GetWindowSize(k.BitLength); - WNafPreCompInfo wnafPreCompInfo = WNafUtilities.Precompute(p, width, true); - ECPoint[] preComp = wnafPreCompInfo.PreComp; - ECPoint[] preCompNeg = wnafPreCompInfo.PreCompNeg; + WNafPreCompInfo info = WNafUtilities.Precompute(p, minWidth, true); + ECPoint[] preComp = info.PreComp; + ECPoint[] preCompNeg = info.PreCompNeg; + int width = info.Width; int[] wnaf = WNafUtilities.GenerateCompactWindowNaf(width, k); @@ -46,7 +48,7 @@ namespace Org.BouncyCastle.Math.EC.Multiplier // Optimization can only be used for values in the lower half of the table if ((n << 2) < (1 << width)) { - int highest = LongArray.BitLengths[n]; + int highest = 32 - Integers.NumberOfLeadingZeros(n); // TODO Get addition/doubling cost ratio from curve and compare to 'scale' to see if worth substituting? int scale = width - highest; @@ -83,16 +85,5 @@ namespace Org.BouncyCastle.Math.EC.Multiplier return R; } - - /** - * Determine window width to use for a scalar multiplication of the given size. - * - * @param bits the bit-length of the scalar to multiply by - * @return the window size to use - */ - protected virtual int GetWindowSize(int bits) - { - return WNafUtilities.GetWindowSize(bits); - } } } |