diff options
Diffstat (limited to 'crypto/src/math/ec/custom/sec/SecP521R1Field.cs')
-rw-r--r-- | crypto/src/math/ec/custom/sec/SecP521R1Field.cs | 41 |
1 files changed, 28 insertions, 13 deletions
diff --git a/crypto/src/math/ec/custom/sec/SecP521R1Field.cs b/crypto/src/math/ec/custom/sec/SecP521R1Field.cs index f39a0daa6..38b177c0d 100644 --- a/crypto/src/math/ec/custom/sec/SecP521R1Field.cs +++ b/crypto/src/math/ec/custom/sec/SecP521R1Field.cs @@ -24,7 +24,7 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec public static void AddOne(uint[] x, uint[] z) { Array.Copy(x, 0, z, 0, 16); - uint c = Nat.Inc(16, z, 0) + z[16]; + uint c = Nat.Inc(16, z, 0) + x[16]; if (c > P16 || (c == P16 && Nat.Eq(16, z, P))) { c += Nat.Inc(16, z, 0); @@ -45,15 +45,15 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec public static void Half(uint[] x, uint[] z) { - uint c0 = x[0] & 1, x16 = x[16], c512 = x16 & 1; - Nat.ShiftDownBit(16, x, c512, z); - z[16] = (x16 >> 1) | (c0 << 8); + uint x16 = x[16]; + uint c = Nat.ShiftDownBit(16, x, x16, z); + z[16] = (x16 >> 1) | (c >> 23); } public static void Multiply(uint[] x, uint[] y, uint[] z) { - uint[] tt = Nat.Create(34); - Nat.Mul(17, x, y, tt); + uint[] tt = Nat.Create(33); + ImplMultiply(x, y, tt); Reduce(tt, z); } @@ -71,10 +71,9 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec public static void Reduce(uint[] xx, uint[] z) { - Debug.Assert(xx[33] == 0); Debug.Assert(xx[32] >> 18 == 0); uint xx32 = xx[32]; - uint c = Nat.ShiftDownBitsExt(16, xx, 16, 9, xx32, z) >> 23; + uint c = Nat.ShiftDownBits(16, xx, 16, 9, xx32, z) >> 23; c += xx32 >> 9; c += Nat.Add(16, z, xx, z); if (c > P16 || (c == P16 && Nat.Eq(16, z, P))) @@ -99,21 +98,21 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec public static void Square(uint[] x, uint[] z) { - uint[] tt = Nat.Create(34); - Nat.Square(17, x, tt); + uint[] tt = Nat.Create(33); + ImplSquare(x, tt); Reduce(tt, z); } public static void SquareN(uint[] x, int n, uint[] z) { Debug.Assert(n > 0); - uint[] tt = Nat.Create(34); - Nat.Square(17, x, tt); + uint[] tt = Nat.Create(33); + ImplSquare(x, tt); Reduce(tt, z); while (--n > 0) { - Nat.Square(17, z, tt); + ImplSquare(z, tt); Reduce(tt, z); } } @@ -139,5 +138,21 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec } z[16] = c; } + + protected static void ImplMultiply(uint[] x, uint[] y, uint[] zz) + { + Nat512.Mul(x, y, zz); + + uint x16 = x[16], y16 = y[16]; + zz[32] = Nat.Mul31BothAdd(16, x16, y, y16, x, zz, 16) + (x16 * y16); + } + + protected static void ImplSquare(uint[] x, uint[] zz) + { + Nat512.Square(x, zz); + + uint x16 = x[16]; + zz[32] = Nat.MulWordAdd(16, x16 << 1, x, zz, 16) + (x16 * x16); + } } } |