x9integerconverter.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:   X9IntegerConverter.java

package org.bouncycastle.asn1.x9;

import java.math.BigInteger;
import org.bouncycastle.math.ec.ECCurve;
import org.bouncycastle.math.ec.ECFieldElement;

public class X9IntegerConverter
{

	public X9IntegerConverter()
	{
	}

	public int getByteLength(ECCurve c)
	{
		return (c.getFieldSize() + 7) / 8;
	}

	public int getByteLength(ECFieldElement fe)
	{
		return (fe.getFieldSize() + 7) / 8;
	}

	public byte[] integerToBytes(BigInteger s, int qLength)
	{
		byte bytes[] = s.toByteArray();
		if (qLength < bytes.length)
		{
			byte tmp[] = new byte[qLength];
			System.arraycopy(bytes, bytes.length - tmp.length, tmp, 0, tmp.length);
			return tmp;
		}
		if (qLength > bytes.length)
		{
			byte tmp[] = new byte[qLength];
			System.arraycopy(bytes, 0, tmp, tmp.length - bytes.length, bytes.length);
			return tmp;
		} else
		{
			return bytes;
		}
	}
}