pkcs5s1parametersgenerator.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:   PKCS5S1ParametersGenerator.java

package jit.crypto.generators;

import jit.crypto.*;
import jit.crypto.params.KeyParameter;
import jit.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(String.valueOf(String.valueOf((new StringBuffer("Can't generate a derived key ")).append(keySize).append(" bytes long."))));
        } 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(String.valueOf(String.valueOf((new StringBuffer("Can't generate a derived key ")).append(keySize + ivSize).append(" bytes long."))));
        } else
        {
            byte dKey[] = generateDerivedKey();
            return new ParametersWithIV(new KeyParameter(dKey, 0, keySize), dKey, keySize, ivSize);
        }
    }

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