init commit

output/Libraries/BouncyCastle.Crypto/Org/BouncyCastle/Math/EC/Endo/ECEndomorphism.cs

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+namespace Org.BouncyCastle.Math.EC.Endo;
+
+public interface ECEndomorphism
+{
+	ECPointMap PointMap { get; }
+
+	bool HasEfficientPointMap { get; }
+}

output/Libraries/BouncyCastle.Crypto/Org/BouncyCastle/Math/EC/Endo/GlvEndomorphism.cs

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+namespace Org.BouncyCastle.Math.EC.Endo;
+
+public interface GlvEndomorphism : ECEndomorphism
+{
+	BigInteger[] DecomposeScalar(BigInteger k);
+}

output/Libraries/BouncyCastle.Crypto/Org/BouncyCastle/Math/EC/Endo/GlvTypeBEndomorphism.cs

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+namespace Org.BouncyCastle.Math.EC.Endo;
+
+public class GlvTypeBEndomorphism : GlvEndomorphism, ECEndomorphism
+{
+	protected readonly ECCurve m_curve;
+
+	protected readonly GlvTypeBParameters m_parameters;
+
+	protected readonly ECPointMap m_pointMap;
+
+	public virtual ECPointMap PointMap => m_pointMap;
+
+	public virtual bool HasEfficientPointMap => true;
+
+	public GlvTypeBEndomorphism(ECCurve curve, GlvTypeBParameters parameters)
+	{
+		m_curve = curve;
+		m_parameters = parameters;
+		m_pointMap = new ScaleXPointMap(curve.FromBigInteger(parameters.Beta));
+	}
+
+	public virtual BigInteger[] DecomposeScalar(BigInteger k)
+	{
+		int bits = m_parameters.Bits;
+		BigInteger bigInteger = CalculateB(k, m_parameters.G1, bits);
+		BigInteger bigInteger2 = CalculateB(k, m_parameters.G2, bits);
+		BigInteger[] v = m_parameters.V1;
+		BigInteger[] v2 = m_parameters.V2;
+		BigInteger bigInteger3 = k.Subtract(bigInteger.Multiply(v[0]).Add(bigInteger2.Multiply(v2[0])));
+		BigInteger bigInteger4 = bigInteger.Multiply(v[1]).Add(bigInteger2.Multiply(v2[1])).Negate();
+		return new BigInteger[2] { bigInteger3, bigInteger4 };
+	}
+
+	protected virtual BigInteger CalculateB(BigInteger k, BigInteger g, int t)
+	{
+		bool flag = g.SignValue < 0;
+		BigInteger bigInteger = k.Multiply(g.Abs());
+		bool flag2 = bigInteger.TestBit(t - 1);
+		bigInteger = bigInteger.ShiftRight(t);
+		if (flag2)
+		{
+			bigInteger = bigInteger.Add(BigInteger.One);
+		}
+		if (!flag)
+		{
+			return bigInteger;
+		}
+		return bigInteger.Negate();
+	}
+}

output/Libraries/BouncyCastle.Crypto/Org/BouncyCastle/Math/EC/Endo/GlvTypeBParameters.cs

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+namespace Org.BouncyCastle.Math.EC.Endo;
+
+public class GlvTypeBParameters
+{
+	protected readonly BigInteger m_beta;
+
+	protected readonly BigInteger m_lambda;
+
+	protected readonly BigInteger[] m_v1;
+
+	protected readonly BigInteger[] m_v2;
+
+	protected readonly BigInteger m_g1;
+
+	protected readonly BigInteger m_g2;
+
+	protected readonly int m_bits;
+
+	public virtual BigInteger Beta => m_beta;
+
+	public virtual BigInteger Lambda => m_lambda;
+
+	public virtual BigInteger[] V1 => m_v1;
+
+	public virtual BigInteger[] V2 => m_v2;
+
+	public virtual BigInteger G1 => m_g1;
+
+	public virtual BigInteger G2 => m_g2;
+
+	public virtual int Bits => m_bits;
+
+	public GlvTypeBParameters(BigInteger beta, BigInteger lambda, BigInteger[] v1, BigInteger[] v2, BigInteger g1, BigInteger g2, int bits)
+	{
+		m_beta = beta;
+		m_lambda = lambda;
+		m_v1 = v1;
+		m_v2 = v2;
+		m_g1 = g1;
+		m_g2 = g2;
+		m_bits = bits;
+	}
+}