des.java

一个非常好的ssh客户端实现

/******************************************************************************
 *
 * Copyright (c) 1999-2003 AppGate Network Security AB. All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code as
 * defined in and that are subject to the MindTerm Public Source License,
 * Version 2.0, (the 'License'). You may not use this file except in compliance
 * with the License.
 * 
 * You should have received a copy of the MindTerm Public Source License
 * along with this software; see the file LICENSE.  If not, write to
 * AppGate Network Security AB, Otterhallegatan 2, SE-41118 Goteborg, SWEDEN
 *
 *****************************************************************************/

package com.mindbright.security.cipher;

import com.mindbright.jca.security.InvalidKeyException;

public final class DES extends BlockCipher {

    private final static int BLOCK_SIZE = 8; // bytes in a data-block

    int[] key_schedule;

    public DES() {
	key_schedule = new int[32];
    }

    public int getBlockSize() {
	return BLOCK_SIZE;
    }

    public synchronized void initializeKey(byte[] key)
	throws InvalidKeyException
    {
	int i, c, d, t, s, shifts;

	c = getIntLSBO(key, 0);
	d = getIntLSBO(key, 4);

	t  = ((d >>> 4) ^ c)  & 0x0f0f0f0f;
	c ^= t;
	d ^= t << 4;
	t = (((c << (16 - (-2))) ^ c) & 0xcccc0000);
	c = c ^ t ^ (t >>> (16 - (-2)));
	t = (((d << (16 - (-2))) ^ d) & 0xcccc0000);
	d = d ^ t ^ (t >>> (16 - (-2)));
	t  = ((d >>> 1) ^ c)  & 0x55555555;
	c ^= t;
	d ^= t << 1;
	t  = ((c >>> 8) ^ d)  & 0x00ff00ff;
	d ^= t;
	c ^= t << 8;
	t  = ((d >>> 1) ^ c)  & 0x55555555;
	c ^= t;
	d ^= t << 1;

	d  = ((d & 0xff) << 16) | (d & 0xff00) |
	    ((d >>> 16) & 0xff) | ((c >>> 4) & 0xf000000);
	c &= 0x0fffffff;
	shifts = 0x7efc;

	for(i = 0; i < 16; i++) {
	    if((shifts & 1) != 0) {
		c = ((c >>> 2) | (c << 26));
		d = ((d >>> 2) | (d << 26));
	    } else {
		c = ((c >>> 1) | (c << 27));
		d = ((d >>> 1) | (d << 27));
	    }
	    shifts >>>= 1;
	    c &= 0x0fffffff;
	    d &= 0x0fffffff;

	    s = des_skb[0][ (c) & 0x3f] |
		des_skb[1][((c >>> 6 ) & 0x03)|((c >>> 7 ) & 0x3c)] |
		des_skb[2][((c >>> 13) & 0x0f)|((c >>> 14) & 0x30)] |
		des_skb[3][((c >>> 20) & 0x01)|((c >>> 21) & 0x06) | ((c >>> 22) & 0x38)];

	    t = des_skb[4][ (d) & 0x3f] |
		des_skb[5][((d >>> 7 ) & 0x03) | ((d >>> 8 ) & 0x3c)] |
		des_skb[6][ (d >>> 15) & 0x3f                ] |
		des_skb[7][((d >>> 21) & 0x0f) | ((d >>> 22) & 0x30)];

	    key_schedule[i * 2]       = ((t << 16) | (s & 0xffff));
	    s                         = ((s >>> 16) | (t & 0xffff0000));
	    key_schedule[(i * 2) + 1] =  (s << 4)  | (s >>> 28);
	}
    }

    public void blockEncrypt(byte[] in, int inOffset, byte[] out, int outOffset) {
	int t, i;
	int[] lr = new int[2];

	lr[0] = getIntLSBO(in, inOffset);
	lr[1] = getIntLSBO(in, inOffset + 4);

	initPerm(lr);

	t = (lr[1] << 1) | (lr[1] >>> 31);
	lr[1] = (lr[0] << 1) | (lr[0] >>> 31);
	lr[0] = t;

	for (i = 0; i < 32; i += 4) {
	    desCipher1(lr, i);
	    desCipher2(lr, i + 2);
	}

	lr[0] = (lr[0] >>> 1) | (lr[0] << 31);
	lr[1] = (lr[1] >>> 1) | (lr[1] << 31);

	finalPerm(lr);

	putIntLSBO(lr[0], out, outOffset);
	putIntLSBO(lr[1], out, outOffset + 4);
    }

    public void blockDecrypt(byte[] in, int inOffset, byte[] out, int outOffset) {
	int t, i;
	int[] lr = new int[2];

	lr[0] = getIntLSBO(in, inOffset);
	lr[1] = getIntLSBO(in, inOffset + 4);

	initPerm(lr);

	t = (lr[1] << 1) | (lr[1] >>> 31);
	lr[1] = (lr[0] << 1) | (lr[0] >>> 31);
	lr[0] = t;

	for (i = 30; i > 0; i -= 4) {
	    desCipher1(lr, i);
	    desCipher2(lr, i - 2);
	}

	lr[0] = (lr[0] >>> 1) | (lr[0] << 31);
	lr[1] = (lr[1] >>> 1) | (lr[1] << 31);

	finalPerm(lr);

	putIntLSBO(lr[0], out, outOffset);
	putIntLSBO(lr[1], out, outOffset + 4);
    }

    final void desCipher1(int[] lr, int i) {
	int u = lr[1] ^ key_schedule[i    ];
	int t = lr[1] ^ key_schedule[i + 1];
	t = ((t >>> 4) + (t << 28));
	lr[0] ^= (des_SPtrans[1][(t       ) & 0x3f] |
		  des_SPtrans[3][(t >>> 8 ) & 0x3f] |
		  des_SPtrans[5][(t >>> 16) & 0x3f] |
		  des_SPtrans[7][(t >>> 24) & 0x3f] |
		  des_SPtrans[0][(u       ) & 0x3f] |
		  des_SPtrans[2][(u >>> 8 ) & 0x3f] |
		  des_SPtrans[4][(u >>> 16) & 0x3f] |
		  des_SPtrans[6][(u >>> 24) & 0x3f]);
    }

    final void desCipher2(int[] lr, int i) {
	int u = lr[0] ^ key_schedule[i    ];
	int t = lr[0] ^ key_schedule[i + 1];
	t = ((t >>> 4) + (t << 28));
	lr[1] ^= (des_SPtrans[1][(t       ) & 0x3f] |
		  des_SPtrans[3][(t >>> 8 ) & 0x3f] |
		  des_SPtrans[5][(t >>> 16) & 0x3f] |
		  des_SPtrans[7][(t >>> 24) & 0x3f] |
		  des_SPtrans[0][(u       ) & 0x3f] |
		  des_SPtrans[2][(u >>> 8 ) & 0x3f] |
		  des_SPtrans[4][(u >>> 16) & 0x3f] |
		  des_SPtrans[6][(u >>> 24) & 0x3f]);
    }

    final static void initPerm(int[] lr) {
	int t  = ((lr[1] >>> 4) ^ lr[0])  & 0x0f0f0f0f;
	lr[0] ^= t;
	lr[1] ^= t << 4;
	t  = ((lr[0] >>> 16) ^ lr[1]) & 0x0000ffff;
	lr[1] ^= t;
	lr[0] ^= t << 16;
	t  = ((lr[1] >>> 2) ^ lr[0])  & 0x33333333;
	lr[0] ^= t;
	lr[1] ^= t << 2;
	t  = ((lr[0] >>> 8) ^ lr[1])  & 0x00ff00ff;
	lr[1] ^= t;
	lr[0] ^= t << 8;
	t  = ((lr[1] >>> 1) ^ lr[0])  & 0x55555555;
	lr[0] ^= t;
	lr[1] ^= t << 1;
    }

    final static void finalPerm(int[] lr) {
	int t  = ((lr[1] >>> 1) ^ lr[0])  & 0x55555555;
	lr[0] ^= t;
	lr[1] ^= t << 1;
	t  = ((lr[0] >>> 8) ^ lr[1])  & 0x00ff00ff;
	lr[1] ^= t;
	lr[0] ^= t << 8;
	t  = ((lr[1] >>> 2) ^ lr[0])  & 0x33333333;
	lr[0] ^= t;
	lr[1] ^= t << 2;
	t  = ((lr[0] >>> 16) ^ lr[1]) & 0x0000ffff;
	lr[1] ^= t;
	lr[0] ^= t << 16;
	t  = ((lr[1] >>> 4) ^ lr[0])  & 0x0f0f0f0f;
	lr[0] ^= t;
	lr[1] ^= t << 4;
    }
  
    /* Table for key generation.  This used to be in sk.h.
     * Copyright (C) 1993 Eric Young - see README for more details
     */
    final static int des_skb[][] = {
	/* for C bits (numbered as per FIPS 46) 1 2 3 4 5 6 */
	{ 0x00000000,0x00000010,0x20000000,0x20000010,
	  0x00010000,0x00010010,0x20010000,0x20010010,
	  0x00000800,0x00000810,0x20000800,0x20000810,
	  0x00010800,0x00010810,0x20010800,0x20010810,
	  0x00000020,0x00000030,0x20000020,0x20000030,
	  0x00010020,0x00010030,0x20010020,0x20010030,
	  0x00000820,0x00000830,0x20000820,0x20000830,
	  0x00010820,0x00010830,0x20010820,0x20010830,
	  0x00080000,0x00080010,0x20080000,0x20080010,
	  0x00090000,0x00090010,0x20090000,0x20090010,
	  0x00080800,0x00080810,0x20080800,0x20080810,
	  0x00090800,0x00090810,0x20090800,0x20090810,
	  0x00080020,0x00080030,0x20080020,0x20080030,
	  0x00090020,0x00090030,0x20090020,0x20090030,
	  0x00080820,0x00080830,0x20080820,0x20080830,
	  0x00090820,0x00090830,0x20090820,0x20090830 },
	/* for C bits (numbered as per FIPS 46) 7 8 10 11 12 13 */
	{ 0x00000000,0x02000000,0x00002000,0x02002000,
	  0x00200000,0x02200000,0x00202000,0x02202000,
	  0x00000004,0x02000004,0x00002004,0x02002004,
	  0x00200004,0x02200004,0x00202004,0x02202004,
	  0x00000400,0x02000400,0x00002400,0x02002400,
	  0x00200400,0x02200400,0x00202400,0x02202400,
	  0x00000404,0x02000404,0x00002404,0x02002404,
	  0x00200404,0x02200404,0x00202404,0x02202404,
	  0x10000000,0x12000000,0x10002000,0x12002000,
	  0x10200000,0x12200000,0x10202000,0x12202000,
	  0x10000004,0x12000004,0x10002004,0x12002004,
	  0x10200004,0x12200004,0x10202004,0x12202004,
	  0x10000400,0x12000400,0x10002400,0x12002400,
	  0x10200400,0x12200400,0x10202400,0x12202400,
	  0x10000404,0x12000404,0x10002404,0x12002404,
	  0x10200404,0x12200404,0x10202404,0x12202404 },
	/* for C bits (numbered as per FIPS 46) 14 15 16 17 19 20 */
	{ 0x00000000,0x00000001,0x00040000,0x00040001,
	  0x01000000,0x01000001,0x01040000,0x01040001,
	  0x00000002,0x00000003,0x00040002,0x00040003,
	  0x01000002,0x01000003,0x01040002,0x01040003,
	  0x00000200,0x00000201,0x00040200,0x00040201,
	  0x01000200,0x01000201,0x01040200,0x01040201,
	  0x00000202,0x00000203,0x00040202,0x00040203,
	  0x01000202,0x01000203,0x01040202,0x01040203,
	  0x08000000,0x08000001,0x08040000,0x08040001,
	  0x09000000,0x09000001,0x09040000,0x09040001,
	  0x08000002,0x08000003,0x08040002,0x08040003,
	  0x09000002,0x09000003,0x09040002,0x09040003,
	  0x08000200,0x08000201,0x08040200,0x08040201,
	  0x09000200,0x09000201,0x09040200,0x09040201,
	  0x08000202,0x08000203,0x08040202,0x08040203,
	  0x09000202,0x09000203,0x09040202,0x09040203 },
	/* for C bits (numbered as per FIPS 46) 21 23 24 26 27 28 */
	{ 0x00000000,0x00100000,0x00000100,0x00100100,
	  0x00000008,0x00100008,0x00000108,0x00100108,