pkcs5s2parametersgenerator.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:   PKCS5S2ParametersGenerator.java

package jit.crypto.generators;

import jit.crypto.*;
import jit.crypto.digests.SHA1Digest;
import jit.crypto.macs.HMac;
import jit.crypto.params.KeyParameter;
import jit.crypto.params.ParametersWithIV;

public class PKCS5S2ParametersGenerator extends PBEParametersGenerator
{

    private Mac hMac;

    public PKCS5S2ParametersGenerator()
    {
        hMac = new HMac(new SHA1Digest());
    }

    private void F(byte P[], byte S[], int c, byte iBuf[], byte out[], int outOff)
    {
        byte state[] = new byte[hMac.getMacSize()];
        CipherParameters param = new KeyParameter(P);
        hMac.init(param);
        if(S != null)
            hMac.update(S, 0, S.length);
        hMac.update(iBuf, 0, iBuf.length);
        hMac.doFinal(state, 0);
        System.arraycopy(state, 0, out, outOff, state.length);
        for(int count = 1; count != c; count++)
        {
            hMac.init(param);
            hMac.update(state, 0, state.length);
            hMac.doFinal(state, 0);
            for(int j = 0; j != state.length; j++)
                out[outOff + j] ^= state[j];

        }

    }

    private void intToOctet(byte buf[], int i)
    {
        buf[0] = (byte)(i >>> 24);
        buf[1] = (byte)(i >>> 16);
        buf[2] = (byte)(i >>> 8);
        buf[3] = (byte)i;
    }

    private byte[] generateDerivedKey(int dkLen)
    {
        int hLen = hMac.getMacSize();
        int l = ((dkLen + hLen) - 1) / hLen;
        byte iBuf[] = new byte[4];
        byte out[] = new byte[l * hLen];
        for(int i = 1; i <= l; i++)
        {
            intToOctet(iBuf, i);
            F(password, salt, iterationCount, iBuf, out, (i - 1) * hLen);
        }

        return out;
    }

    public CipherParameters generateDerivedParameters(int keySize)
    {
        keySize /= 8;
        byte dKey[] = generateDerivedKey(keySize);
        return new KeyParameter(dKey, 0, keySize);
    }

    public CipherParameters generateDerivedParameters(int keySize, int ivSize)
    {
        keySize /= 8;
        ivSize /= 8;
        byte dKey[] = generateDerivedKey(keySize + ivSize);
        return new ParametersWithIV(new KeyParameter(dKey, 0, keySize), dKey, keySize, ivSize);
    }

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