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| author | Peter Dettman <peter.dettman@bouncycastle.org> | 2014-01-25 20:52:28 +0700 |
|---|---|---|
| committer | Peter Dettman <peter.dettman@bouncycastle.org> | 2014-01-25 20:52:28 +0700 |
| commit | 0d360477865400dfe98e1aeade606d57e11def80 (patch) | |
| tree | 3593e41ff9dd374c7c315bc90291a67cf262fb7f /crypto/src/math/ec/ECCurve.cs | |
| parent | Change F2m test curve to match Java version more clearly (diff) | |
| download | BouncyCastle.NET-ed25519-0d360477865400dfe98e1aeade606d57e11def80.tar.xz | |
Port latest Java fixes for lambda-projective and make it the default for F2m
Diffstat (limited to 'crypto/src/math/ec/ECCurve.cs')
| -rw-r--r-- | crypto/src/math/ec/ECCurve.cs | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/crypto/src/math/ec/ECCurve.cs b/crypto/src/math/ec/ECCurve.cs index 832145e2e..9679fdb89 100644 --- a/crypto/src/math/ec/ECCurve.cs +++ b/crypto/src/math/ec/ECCurve.cs @@ -463,7 +463,7 @@ namespace Org.BouncyCastle.Math.EC */ public class F2mCurve : ECCurve { - private const int F2M_DEFAULT_COORDS = COORD_AFFINE; + private const int F2M_DEFAULT_COORDS = COORD_LAMBDA_PROJECTIVE; private static IFiniteField BuildField(int m, int k1, int k2, int k3) { @@ -827,7 +827,12 @@ namespace Org.BouncyCastle.Math.EC case COORD_LAMBDA_AFFINE: case COORD_LAMBDA_PROJECTIVE: { - if (!X.IsZero) + if (X.IsZero) + { + if (!Y.Square().Equals(B)) + throw new ArgumentException(); + } + else { // Y becomes Lambda (X + Y/X) here Y = Y.Divide(X).Add(X); @@ -847,16 +852,11 @@ namespace Org.BouncyCastle.Math.EC int yTilde, BigInteger X1) { - ECFieldElement xp = FromBigInteger(X1); - ECFieldElement yp = null; + ECFieldElement yp; if (xp.IsZero) { - yp = (F2mFieldElement)m_b; - for (int i = 0; i < m - 1; i++) - { - yp = yp.Square(); - } + yp = m_b.Sqrt(); } else { |