x9curve.java

java 文件下载器。可自定义

// Decompiled by Jad v1.5.8e2. Copyright 2001 Pavel Kouznetsov.
// Jad home page: http://kpdus.tripod.com/jad.html
// Decompiler options: packimports(3) fieldsfirst ansi space 
// Source File Name:   X9Curve.java

package org.bouncycastle.asn1.x9;

import org.bouncycastle.asn1.*;
import org.bouncycastle.math.ec.ECCurve;
import org.bouncycastle.math.ec.ECFieldElement;

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

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(prime_field))
		{
			java.math.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 org.bouncycastle.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);
	}
}