org.bouncycastle.math.ec.custom.sec.SecT233K1Curve Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of bcprov-ext-debug-jdk18on Show documentation
The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains JCE provider and lightweight API for the Bouncy Castle Cryptography APIs for Java 1.8 and later with debug enabled.
The newest version!
package org.bouncycastle.math.ec.custom.sec;

import java.math.BigInteger;

import org.bouncycastle.math.ec.AbstractECLookupTable;
import org.bouncycastle.math.ec.ECConstants;
import org.bouncycastle.math.ec.ECCurve;
import org.bouncycastle.math.ec.ECCurve.AbstractF2m;
import org.bouncycastle.math.ec.ECFieldElement;
import org.bouncycastle.math.ec.ECLookupTable;
import org.bouncycastle.math.ec.ECMultiplier;
import org.bouncycastle.math.ec.ECPoint;
import org.bouncycastle.math.ec.WTauNafMultiplier;
import org.bouncycastle.math.raw.Nat256;
import org.bouncycastle.util.encoders.Hex;

public class SecT233K1Curve extends AbstractF2m
{
    private static final int SECT233K1_DEFAULT_COORDS = COORD_LAMBDA_PROJECTIVE;
    private static final ECFieldElement[] SECT233K1_AFFINE_ZS = new ECFieldElement[] { new SecT233FieldElement(ECConstants.ONE) }; 

    protected SecT233K1Point infinity;

    public SecT233K1Curve()
    {
        super(233, 74, 0, 0);

        this.infinity = new SecT233K1Point(this, null, null);

        this.a = fromBigInteger(BigInteger.valueOf(0));
        this.b = fromBigInteger(BigInteger.valueOf(1));
        this.order = new BigInteger(1, Hex.decodeStrict("8000000000000000000000000000069D5BB915BCD46EFB1AD5F173ABDF"));
        this.cofactor = BigInteger.valueOf(4);

        this.coord = SECT233K1_DEFAULT_COORDS;
    }

    protected ECCurve cloneCurve()
    {
        return new SecT233K1Curve();
    }

    public boolean supportsCoordinateSystem(int coord)
    {
        switch (coord)
        {
        case COORD_LAMBDA_PROJECTIVE:
            return true;
        default:
            return false;
        }
    }

    protected ECMultiplier createDefaultMultiplier()
    {
        return new WTauNafMultiplier();
    }

    public int getFieldSize()
    {
        return 233;
    }

    public ECFieldElement fromBigInteger(BigInteger x)
    {
        return new SecT233FieldElement(x);
    }

    protected ECPoint createRawPoint(ECFieldElement x, ECFieldElement y)
    {
        return new SecT233K1Point(this, x, y);
    }

    protected ECPoint createRawPoint(ECFieldElement x, ECFieldElement y, ECFieldElement[] zs)
    {
        return new SecT233K1Point(this, x, y, zs);
    }

    public ECPoint getInfinity()
    {
        return infinity;
    }

    public boolean isKoblitz()
    {
        return true;
    }

    public int getM()
    {
        return 233;
    }

    public boolean isTrinomial()
    {
        return true;
    }

    public int getK1()
    {
        return 74;
    }

    public int getK2()
    {
        return 0;
    }

    public int getK3()
    {
        return 0;
    }

    public ECLookupTable createCacheSafeLookupTable(ECPoint[] points, int off, final int len)
    {
        final int FE_LONGS = 4;

        final long[] table = new long[len * FE_LONGS * 2];
        {
            int pos = 0;
            for (int i = 0; i < len; ++i)
            {
                ECPoint p = points[off + i];
                Nat256.copy64(((SecT233FieldElement)p.getRawXCoord()).x, 0, table, pos); pos += FE_LONGS;
                Nat256.copy64(((SecT233FieldElement)p.getRawYCoord()).x, 0, table, pos); pos += FE_LONGS;
            }
        }

        return new AbstractECLookupTable()
        {
            public int getSize()
            {
                return len;
            }

            public ECPoint lookup(int index)
            {
                long[] x = Nat256.create64(), y = Nat256.create64();
                int pos = 0;

                for (int i = 0; i < len; ++i)
                {
                    long MASK = ((i ^ index) - 1) >> 31;

                    for (int j = 0; j < FE_LONGS; ++j)
                    {
                        x[j] ^= table[pos + j] & MASK;
                        y[j] ^= table[pos + FE_LONGS + j] & MASK;
                    }

                    pos += (FE_LONGS * 2);
                }

                return createPoint(x, y);
            }

            public ECPoint lookupVar(int index)
            {
                long[] x = Nat256.create64(), y = Nat256.create64();
                int pos = index * FE_LONGS * 2;

                for (int j = 0; j < FE_LONGS; ++j)
                {
                    x[j] = table[pos + j];
                    y[j] = table[pos + FE_LONGS + j];
                }

                return createPoint(x, y);
            }

            private ECPoint createPoint(long[] x, long[] y)
            {
                return createRawPoint(new SecT233FieldElement(x), new SecT233FieldElement(y), SECT233K1_AFFINE_ZS);
            }
        };
    }
}