org.bouncycastle.math.ec.custom.sec.SecP128R1Curve 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 java.security.SecureRandom;

import org.bouncycastle.math.ec.AbstractECLookupTable;
import org.bouncycastle.math.ec.ECConstants;
import org.bouncycastle.math.ec.ECCurve;
import org.bouncycastle.math.ec.ECFieldElement;
import org.bouncycastle.math.ec.ECLookupTable;
import org.bouncycastle.math.ec.ECPoint;
import org.bouncycastle.math.raw.Nat128;
import org.bouncycastle.util.encoders.Hex;

public class SecP128R1Curve extends ECCurve.AbstractFp
{
    public static final BigInteger q = SecP128R1FieldElement.Q;

    private static final int SECP128R1_DEFAULT_COORDS = COORD_JACOBIAN;
    private static final ECFieldElement[] SECP128R1_AFFINE_ZS = new ECFieldElement[] { new SecP128R1FieldElement(ECConstants.ONE) }; 

    protected SecP128R1Point infinity;

    public SecP128R1Curve()
    {
        super(q);

        this.infinity = new SecP128R1Point(this, null, null);

        this.a = fromBigInteger(new BigInteger(1,
            Hex.decodeStrict("FFFFFFFDFFFFFFFFFFFFFFFFFFFFFFFC")));
        this.b = fromBigInteger(new BigInteger(1,
            Hex.decodeStrict("E87579C11079F43DD824993C2CEE5ED3")));
        this.order = new BigInteger(1, Hex.decodeStrict("FFFFFFFE0000000075A30D1B9038A115"));
        this.cofactor = BigInteger.valueOf(1);

        this.coord = SECP128R1_DEFAULT_COORDS;
    }

    protected ECCurve cloneCurve()
    {
        return new SecP128R1Curve();
    }

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

    public BigInteger getQ()
    {
        return q;
    }

    public int getFieldSize()
    {
        return q.bitLength();
    }

    public ECFieldElement fromBigInteger(BigInteger x)
    {
        return new SecP128R1FieldElement(x);
    }

    protected ECPoint createRawPoint(ECFieldElement x, ECFieldElement y)
    {
        return new SecP128R1Point(this, x, y);
    }

    protected ECPoint createRawPoint(ECFieldElement x, ECFieldElement y, ECFieldElement[] zs)
    {
        return new SecP128R1Point(this, x, y, zs);
    }

    public ECPoint getInfinity()
    {
        return infinity;
    }

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

        final int[] table = new int[len * FE_INTS * 2];
        {
            int pos = 0;
            for (int i = 0; i < len; ++i)
            {
                ECPoint p = points[off + i];
                Nat128.copy(((SecP128R1FieldElement)p.getRawXCoord()).x, 0, table, pos); pos += FE_INTS;
                Nat128.copy(((SecP128R1FieldElement)p.getRawYCoord()).x, 0, table, pos); pos += FE_INTS;
            }
        }

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

            public ECPoint lookup(int index)
            {
                int[] x = Nat128.create(), y = Nat128.create();
                int pos = 0;

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

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

                    pos += (FE_INTS * 2);
                }

                return createPoint(x, y);
            }

            public ECPoint lookupVar(int index)
            {
                int[] x = Nat128.create(), y = Nat128.create();
                int pos = index * FE_INTS * 2;

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

                return createPoint(x, y);
            }

            private ECPoint createPoint(int[] x, int[] y)
            {
                return createRawPoint(new SecP128R1FieldElement(x), new SecP128R1FieldElement(y), SECP128R1_AFFINE_ZS);
            }
        };
    }

    public ECFieldElement randomFieldElement(SecureRandom r)
    {
        int[] x = Nat128.create();
        SecP128R1Field.random(r, x);
        return new SecP128R1FieldElement(x);
    }

    public ECFieldElement randomFieldElementMult(SecureRandom r)
    {
        int[] x = Nat128.create();
        SecP128R1Field.randomMult(r, x);
        return new SecP128R1FieldElement(x);
    }
}