x9curve.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:   X9Curve.java

package jit.asn1.x9;

import jit.asn1.*;
import jit.math.BigInteger;
import jit.math.ec.ECCurve;
import jit.math.ec.ECFieldElement;

// Referenced classes of package jit.asn1.x9:
//            X9FieldElement, X9ObjectIdentifiers, X9FieldID

public class X9Curve
    implements DEREncodable, X9ObjectIdentifiers
{

    private ECCurve curve;
    private byte seed[];

    public X9Curve(ECCurve curve)
    {
        this.curve = curve;
        seed = null;
    }

    public X9Curve(ECCurve curve, byte seed[])
    {
        this.curve = curve;
        this.seed = seed;
    }

    public X9Curve(X9FieldID fieldID, ASN1Sequence seq)
    {
        if(fieldID.getIdentifier().equals(X9ObjectIdentifiers.prime_field))
        {
            BigInteger q = ((DERInteger)fieldID.getParameters()).getValue();
            X9FieldElement x9A = new X9FieldElement(true, q, (ASN1OctetString)seq.getObjectAt(0));
            X9FieldElement x9B = new X9FieldElement(true, q, (ASN1OctetString)seq.getObjectAt(1));
            curve = new jit.math.ec.ECCurve.Fp(q, x9A.getValue().toBigInteger(), x9B.getValue().toBigInteger());
        } else
        {
            throw new RuntimeException("not implemented");
        }
        if(seq.size() == 3)
            seed = ((DERBitString)seq.getObjectAt(2)).getBytes();
    }

    public ECCurve getCurve()
    {
        return curve;
    }

    public byte[] getSeed()
    {
        return seed;
    }

    public DERObject getDERObject()
    {
        ASN1EncodableVector v = new ASN1EncodableVector();
        v.add((new X9FieldElement(curve.getA())).getDERObject());
        v.add((new X9FieldElement(curve.getB())).getDERObject());
        if(seed != null)
            v.add(new DERBitString(seed));
        return new DERSequence(v);
    }
}