diff options
Diffstat (limited to 'crypto/src/math/ec/ECCurve.cs')
| -rw-r--r-- | crypto/src/math/ec/ECCurve.cs | 175 |
1 files changed, 76 insertions, 99 deletions
diff --git a/crypto/src/math/ec/ECCurve.cs b/crypto/src/math/ec/ECCurve.cs index 339d37f7c..9fe9e32fd 100644 --- a/crypto/src/math/ec/ECCurve.cs +++ b/crypto/src/math/ec/ECCurve.cs @@ -623,6 +623,18 @@ namespace Org.BouncyCastle.Math.EC public abstract class AbstractF2mCurve : ECCurve { + public static BigInteger Inverse(int m, int[] ks, BigInteger x) + { + return new LongArray(x).ModInverse(m, ks).ToBigInteger(); + } + + /** + * The auxiliary values <code>s<sub>0</sub></code> and + * <code>s<sub>1</sub></code> used for partial modular reduction for + * Koblitz curves. + */ + private BigInteger[] si = null; + private static IFiniteField BuildField(int m, int k1, int k2, int k3) { if (k1 == 0) @@ -657,6 +669,69 @@ namespace Org.BouncyCastle.Math.EC : base(BuildField(m, k1, k2, k3)) { } + + [Obsolete("Per-point compression property will be removed")] + public override ECPoint CreatePoint(BigInteger x, BigInteger y, bool withCompression) + { + ECFieldElement X = FromBigInteger(x), Y = FromBigInteger(y); + + switch (this.CoordinateSystem) + { + case COORD_LAMBDA_AFFINE: + case COORD_LAMBDA_PROJECTIVE: + { + 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); + } + break; + } + default: + { + break; + } + } + + return CreateRawPoint(X, Y, withCompression); + } + + /** + * @return the auxiliary values <code>s<sub>0</sub></code> and + * <code>s<sub>1</sub></code> used for partial modular reduction for + * Koblitz curves. + */ + internal virtual BigInteger[] GetSi() + { + if (si == null) + { + lock (this) + { + if (si == null) + { + si = Tnaf.GetSi(this); + } + } + } + return si; + } + + /** + * Returns true if this is a Koblitz curve (ABC curve). + * @return true if this is a Koblitz curve (ABC curve), false otherwise + */ + public virtual bool IsKoblitz + { + get + { + return m_order != null && m_cofactor != null && m_b.IsOne && (m_a.IsZero || m_a.IsOne); + } + } } /** @@ -705,19 +780,6 @@ namespace Org.BouncyCastle.Math.EC protected readonly F2mPoint m_infinity; /** - * The parameter <code>μ</code> of the elliptic curve if this is - * a Koblitz curve. - */ - private sbyte mu = 0; - - /** - * The auxiliary values <code>s<sub>0</sub></code> and - * <code>s<sub>1</sub></code> used for partial modular reduction for - * Koblitz curves. - */ - private BigInteger[] si = null; - - /** * Constructor for Trinomial Polynomial Basis (TPB). * @param m The exponent <code>m</code> of * <code>F<sub>2<sup>m</sup></sub></code>. @@ -917,37 +979,6 @@ namespace Org.BouncyCastle.Math.EC return new F2mFieldElement(this.m, this.k1, this.k2, this.k3, x); } - [Obsolete("Per-point compression property will be removed")] - public override ECPoint CreatePoint(BigInteger x, BigInteger y, bool withCompression) - { - ECFieldElement X = FromBigInteger(x), Y = FromBigInteger(y); - - switch (this.CoordinateSystem) - { - case COORD_LAMBDA_AFFINE: - case COORD_LAMBDA_PROJECTIVE: - { - 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); - } - break; - } - default: - { - break; - } - } - - return CreateRawPoint(X, Y, withCompression); - } - protected internal override ECPoint CreateRawPoint(ECFieldElement x, ECFieldElement y, bool withCompression) { return new F2mPoint(this, x, y, withCompression); @@ -963,60 +994,6 @@ namespace Org.BouncyCastle.Math.EC get { return m_infinity; } } - /** - * Returns true if this is a Koblitz curve (ABC curve). - * @return true if this is a Koblitz curve (ABC curve), false otherwise - */ - public virtual bool IsKoblitz - { - get - { - return m_order != null && m_cofactor != null && m_b.IsOne && (m_a.IsZero || m_a.IsOne); - } - } - - /** - * Returns the parameter <code>μ</code> of the elliptic curve. - * @return <code>μ</code> of the elliptic curve. - * @throws ArgumentException if the given ECCurve is not a - * Koblitz curve. - */ - internal virtual sbyte GetMu() - { - if (mu == 0) - { - lock (this) - { - if (mu == 0) - { - mu = Tnaf.GetMu(this); - } - } - } - - return mu; - } - - /** - * @return the auxiliary values <code>s<sub>0</sub></code> and - * <code>s<sub>1</sub></code> used for partial modular reduction for - * Koblitz curves. - */ - internal virtual BigInteger[] GetSi() - { - if (si == null) - { - lock (this) - { - if (si == null) - { - si = Tnaf.GetSi(this); - } - } - } - return si; - } - protected override ECPoint DecompressPoint(int yTilde, BigInteger X1) { ECFieldElement xp = FromBigInteger(X1), yp = null; @@ -1086,7 +1063,7 @@ namespace Org.BouncyCastle.Math.EC ECFieldElement t = FromBigInteger(new BigInteger(m, rand)); z = zeroElement; ECFieldElement w = beta; - for (int i = 1; i <= m - 1; i++) + for (int i = 1; i < m; i++) { ECFieldElement w2 = w.Square(); z = z.Square().Add(w2.Multiply(t)); |