ecfieldelement$fp.java

进行与数字证书相关开发必须的java源码

// Decompiled by Jad v1.5.7g. Copyright 2000 Pavel Kouznetsov.
// Jad home page: http://www.geocities.com/SiliconValley/Bridge/8617/jad.html
// Decompiler options: packimports(3) fieldsfirst ansi 
// Source File Name:   ECFieldElement.java

package jit.math.ec;

import jit.math.BigInteger;

// Referenced classes of package jit.math.ec:
//            ECFieldElement, ECConstants

public static class Fp extends ECFieldElement
{

    public String getFieldName()
    {
        return "Fp";
    }

    public ECFieldElement add(ECFieldElement b)
    {
        return new Fp(p, x.add(b.x).mod(p));
    }

    public ECFieldElement subtract(ECFieldElement b)
    {
        return new Fp(p, x.subtract(b.x).mod(p));
    }

    public ECFieldElement multiply(ECFieldElement b)
    {
        return new Fp(p, x.multiply(b.x).mod(p));
    }

    public ECFieldElement divide(ECFieldElement b)
    {
        return new Fp(p, x.multiply(b.x.modInverse(p)).mod(p));
    }

    public ECFieldElement negate()
    {
        return new Fp(p, x.negate().mod(p));
    }

    public ECFieldElement square()
    {
        return new Fp(p, x.multiply(x).mod(p));
    }

    public ECFieldElement invert()
    {
        return new Fp(p, x.modInverse(p));
    }

    public ECFieldElement sqrt()
    {
        if(p.testBit(1))
        {
            ECFieldElement z = new Fp(p, x.modPow(p.shiftRight(2).add(ECConstants.ONE), p));
            return z.square().equals(this) ? z : null;
        } else
        {
            throw new RuntimeException("not done yet");
        }
    }

    public Fp(BigInteger q, BigInteger x)
    {
        super(q, x);
    }
}