diff options
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/src/math/ec/ECPoint.cs | 45 |
1 files changed, 28 insertions, 17 deletions
diff --git a/crypto/src/math/ec/ECPoint.cs b/crypto/src/math/ec/ECPoint.cs index d26cfb914..f2b0cdc27 100644 --- a/crypto/src/math/ec/ECPoint.cs +++ b/crypto/src/math/ec/ECPoint.cs @@ -1245,14 +1245,13 @@ namespace Org.BouncyCastle.Math.EC case ECCurve.COORD_LAMBDA_PROJECTIVE: { // Y is actually Lambda (X + Y/X) here - return Y.Subtract(X).TestBitZero(); + return Y.TestBitZero() != X.TestBitZero(); } default: { return Y.Divide(X).TestBitZero(); } } - } } @@ -1312,9 +1311,10 @@ namespace Org.BouncyCastle.Math.EC ECFieldElement Y1 = this.RawYCoord; ECFieldElement Y2 = b.RawYCoord; - if (X1.Equals(X2)) + ECFieldElement dx = X1.Add(X2), dy = Y1.Add(Y2); + if (dx.IsZero) { - if (Y1.Equals(Y2)) + if (dy.IsZero) { return (F2mPoint)Twice(); } @@ -1322,10 +1322,9 @@ namespace Org.BouncyCastle.Math.EC return (F2mPoint)curve.Infinity; } - ECFieldElement sumX = X1.Add(X2); - ECFieldElement L = Y1.Add(Y2).Divide(sumX); + ECFieldElement L = dy.Divide(dx); - ECFieldElement X3 = L.Square().Add(L).Add(sumX).Add(curve.A); + ECFieldElement X3 = L.Square().Add(L).Add(dx).Add(curve.A); ECFieldElement Y3 = L.Multiply(X1.Add(X3)).Add(X3).Add(Y1); return new F2mPoint(curve, X3, Y3, IsCompressed); @@ -1339,14 +1338,14 @@ namespace Org.BouncyCastle.Math.EC ECFieldElement U1 = Z1.Multiply(Y2); ECFieldElement U2 = Z2IsOne ? Y1 : Y1.Multiply(Z2); - ECFieldElement U = U1.Subtract(U2); + ECFieldElement U = U1.Add(U2); ECFieldElement V1 = Z1.Multiply(X2); ECFieldElement V2 = Z2IsOne ? X1 : X1.Multiply(Z2); - ECFieldElement V = V1.Subtract(V2); + ECFieldElement V = V1.Add(V2); - if (V1.Equals(V2)) + if (V.IsZero) { - if (U1.Equals(U2)) + if (U.IsZero) { return (F2mPoint)Twice(); } @@ -1355,13 +1354,17 @@ namespace Org.BouncyCastle.Math.EC } ECFieldElement VSq = V.Square(); + ECFieldElement VCu = VSq.Multiply(V); ECFieldElement W = Z2IsOne ? Z1 : Z1.Multiply(Z2); - ECFieldElement A = U.Square().Add(U.Multiply(V).Add(VSq.Multiply(curve.A))).Multiply(W).Add(V.Multiply(VSq)); + ECFieldElement uv = U.Add(V); + // TODO Delayed modular reduction for sum of products + ECFieldElement A = uv.Multiply(U).Add(VSq.Multiply(curve.A)).Multiply(W).Add(VCu); ECFieldElement X3 = V.Multiply(A); ECFieldElement VSqZ2 = Z2IsOne ? VSq : VSq.Multiply(Z2); - ECFieldElement Y3 = VSqZ2.Multiply(U.Multiply(X1).Add(Y1.Multiply(V))).Add(A.Multiply(U.Add(V))); - ECFieldElement Z3 = VSq.Multiply(V).Multiply(W); + // TODO Delayed modular reduction for sum of products + ECFieldElement Y3 = U.Multiply(X1).Add(Y1.Multiply(V)).Multiply(VSqZ2).Add(A.Multiply(uv)); + ECFieldElement Z3 = VCu.Multiply(W); return new F2mPoint(curve, X3, Y3, new ECFieldElement[] { Z3 }, IsCompressed); } @@ -1447,6 +1450,7 @@ namespace Org.BouncyCastle.Math.EC ABZ2 = ABZ2.Multiply(Z2); } + // TODO Delayed modular reduction for sum of products L3 = AU2.Add(B).Square().Add(ABZ2.Multiply(L1.Add(Z1))); Z3 = ABZ2; @@ -1555,6 +1559,7 @@ namespace Org.BouncyCastle.Math.EC ECFieldElement L1 = Y1.Divide(X1).Add(X1); ECFieldElement X3 = L1.Square().Add(L1).Add(curve.A); + // TODO Delayed modular reduction for sum of products ECFieldElement Y3 = X1.Square().Add(X3.Multiply(L1.AddOne())); return new F2mPoint(curve, X3, Y3, IsCompressed); @@ -1571,10 +1576,13 @@ namespace Org.BouncyCastle.Math.EC ECFieldElement S = X1Sq.Add(Y1Z1); ECFieldElement V = X1Z1; ECFieldElement vSquared = V.Square(); - ECFieldElement h = S.Square().Add(S.Multiply(V)).Add(curve.A.Multiply(vSquared)); + ECFieldElement sv = S.Add(V); + // TODO Delayed modular reduction for sum of products + ECFieldElement h = sv.Multiply(S).Add(curve.A.Multiply(vSquared)); ECFieldElement X3 = V.Multiply(h); - ECFieldElement Y3 = h.Multiply(S.Add(V)).Add(X1Sq.Square().Multiply(V)); + // TODO Delayed modular reduction for sum of products + ECFieldElement Y3 = h.Multiply(sv).Add(X1Sq.Square().Multiply(V)); ECFieldElement Z3 = V.Multiply(vSquared); return new F2mPoint(curve, X3, Y3, new ECFieldElement[] { Z3 }, IsCompressed); @@ -1627,7 +1635,8 @@ namespace Org.BouncyCastle.Math.EC else { ECFieldElement X1Z1 = Z1IsOne ? X1 : X1.Multiply(Z1); - L3 = X1Z1.Square().Add(X3).Add(T.Multiply(L1Z1)).Add(Z3); + // TODO Delayed modular reduction for sum of products + L3 = X1Z1.Square().Add(T.Multiply(L1Z1)).Add(X3).Add(Z3); } return new F2mPoint(curve, X3, L3, new ECFieldElement[] { Z3 }, IsCompressed); @@ -1678,6 +1687,7 @@ namespace Org.BouncyCastle.Math.EC ECFieldElement T = curve.A.Multiply(Z1Sq).Add(L1Sq).Add(L1Z1); ECFieldElement L2plus1 = L2.AddOne(); + // TODO Delayed modular reduction for sum of products ECFieldElement A = curve.A.Add(L2plus1).Multiply(Z1Sq).Add(L1Sq).Multiply(T).Add(X1Sq.Multiply(Z1Sq)); ECFieldElement X2Z1Sq = X2.Multiply(Z1Sq); ECFieldElement B = X2Z1Sq.Add(T).Square(); @@ -1699,6 +1709,7 @@ namespace Org.BouncyCastle.Math.EC ECFieldElement X3 = A.Square().Multiply(X2Z1Sq); ECFieldElement Z3 = A.Multiply(B).Multiply(Z1Sq); + // TODO Delayed modular reduction for sum of products ECFieldElement L3 = A.Add(B).Square().Multiply(T).Add(L2plus1.Multiply(Z3)); return new F2mPoint(curve, X3, L3, new ECFieldElement[] { Z3 }, IsCompressed); |