pkcs5s1parametersgenerator.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:   PKCS5S1ParametersGenerator.java

package org.bouncycastle.crypto.generators;

import org.bouncycastle.crypto.*;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.crypto.params.ParametersWithIV;

public class PKCS5S1ParametersGenerator extends PBEParametersGenerator
{

	private Digest digest;

	public PKCS5S1ParametersGenerator(Digest digest)
	{
		this.digest = digest;
	}

	private byte[] generateDerivedKey()
	{
		byte digestBytes[] = new byte[digest.getDigestSize()];
		digest.update(password, 0, password.length);
		digest.update(salt, 0, salt.length);
		digest.doFinal(digestBytes, 0);
		for (int i = 1; i < iterationCount; i++)
		{
			digest.update(digestBytes, 0, digestBytes.length);
			digest.doFinal(digestBytes, 0);
		}

		return digestBytes;
	}

	public CipherParameters generateDerivedParameters(int keySize)
	{
		keySize /= 8;
		if (keySize > digest.getDigestSize())
		{
			throw new IllegalArgumentException((new StringBuilder()).append("Can't generate a derived key ").append(keySize).append(" bytes long.").toString());
		} else
		{
			byte dKey[] = generateDerivedKey();
			return new KeyParameter(dKey, 0, keySize);
		}
	}

	public CipherParameters generateDerivedParameters(int keySize, int ivSize)
	{
		keySize /= 8;
		ivSize /= 8;
		if (keySize + ivSize > digest.getDigestSize())
		{
			throw new IllegalArgumentException((new StringBuilder()).append("Can't generate a derived key ").append(keySize + ivSize).append(" bytes long.").toString());
		} else
		{
			byte dKey[] = generateDerivedKey();
			return new ParametersWithIV(new KeyParameter(dKey, 0, keySize), dKey, keySize, ivSize);
		}
	}

	public CipherParameters generateDerivedMacParameters(int keySize)
	{
		return generateDerivedParameters(keySize);
	}
}