desedeengine.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:   DESedeEngine.java

package jit.crypto.engines;

import jit.crypto.CipherParameters;
import jit.crypto.DataLengthException;
import jit.crypto.params.KeyParameter;

// Referenced classes of package jit.crypto.engines:
//            DESEngine

public class DESedeEngine extends DESEngine
{

    protected static final int BLOCK_SIZE = 8;
    private int workingKey1[];
    private int workingKey2[];
    private int workingKey3[];
    private boolean forEncryption;

    public DESedeEngine()
    {
        workingKey1 = null;
        workingKey2 = null;
        workingKey3 = null;
    }

    public void init(boolean encrypting, CipherParameters params)
    {
        if(!(params instanceof KeyParameter))
            throw new IllegalArgumentException("invalid parameter passed to DESede init - ".concat(String.valueOf(String.valueOf(params.getClass().getName()))));
        byte keyMaster[] = ((KeyParameter)params).getKey();
        byte key1[] = new byte[8];
        byte key2[] = new byte[8];
        byte key3[] = new byte[8];
        forEncryption = encrypting;
        if(keyMaster.length == 24)
        {
            System.arraycopy(keyMaster, 0, key1, 0, key1.length);
            System.arraycopy(keyMaster, 8, key2, 0, key2.length);
            System.arraycopy(keyMaster, 16, key3, 0, key3.length);
            workingKey1 = generateWorkingKey(encrypting, key1);
            workingKey2 = generateWorkingKey(!encrypting, key2);
            workingKey3 = generateWorkingKey(encrypting, key3);
        } else
        {
            System.arraycopy(keyMaster, 0, key1, 0, key1.length);
            System.arraycopy(keyMaster, 8, key2, 0, key2.length);
            workingKey1 = generateWorkingKey(encrypting, key1);
            workingKey2 = generateWorkingKey(!encrypting, key2);
            workingKey3 = workingKey1;
        }
    }

    public String getAlgorithmName()
    {
        return "DESede";
    }

    public int getBlockSize()
    {
        return 8;
    }

    public int processBlock(byte in[], int inOff, byte out[], int outOff)
    {
        if(workingKey1 == null)
            throw new IllegalStateException("DESede engine not initialised");
        if(inOff + 8 > in.length)
            throw new DataLengthException("input buffer too short");
        if(outOff + 8 > out.length)
            throw new DataLengthException("output buffer too short");
        if(forEncryption)
        {
            desFunc(workingKey1, in, inOff, out, outOff);
            desFunc(workingKey2, out, outOff, out, outOff);
            desFunc(workingKey3, out, outOff, out, outOff);
        } else
        {
            desFunc(workingKey3, in, inOff, out, outOff);
            desFunc(workingKey2, out, outOff, out, outOff);
            desFunc(workingKey1, out, outOff, out, outOff);
        }
        return 8;
    }

    public void reset()
    {
    }

    static 
    {
        BLOCK_SIZE = 8;
    }
}