des.c

在Linux/Unix下面访问WINDOWS SQLSERVER 的ODBC驱动程序

/*
 * Copyright (C) 1998,1999,2000,2001 Nikos Mavroyanopoulos
 * 
 * This library is free software; you can redistribute it and/or modify it 
 * under the terms of the GNU Library General Public License as published 
 * by the Free Software Foundation; either version 2 of the License, or 
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/* Sofware DES functions
 * written 12 Dec 1986 by Phil Karn, KA9Q; large sections adapted from
 * the 1977 public-domain program by Jim Gillogly
 * Modified for additional speed - 6 December 1988 Phil Karn
 * Modified for parameterized key schedules - Jan 1991 Phil Karn
 * Callers now allocate a key schedule as follows:
 *	kn = (char (*)[8])malloc(sizeof(char) * 8 * 16);
 *	or
 *	char kn[16][8];
 */

/* modified in order to use the libmcrypt API by Nikos Mavroyanopoulos 
 * All modifications are placed under the license of libmcrypt.
 */

#if HAVE_CONFIG_H
#include <config.h>
#endif /* HAVE_CONFIG_H */

#if HAVE_STRING_H
#include <string.h>
#endif /* HAVE_STRING_H */

#include "tds.h"
#include "des.h"

TDS_RCSID(var, "$Id: des.c,v 1.15 2005/07/07 13:06:45 freddy77 Exp $");

static void permute_ip(des_cblock inblock, DES_KEY * key, des_cblock outblock);
static void permute_fp(des_cblock inblock, DES_KEY * key, des_cblock outblock);
static void perminit_ip(DES_KEY * key);
static void spinit(DES_KEY * key);
static void perminit_fp(DES_KEY * key);
static TDS_UINT f(DES_KEY * key, register TDS_UINT r, register unsigned char *subkey);

void
tds_des_set_odd_parity(des_cblock key)
{

	int i;
	unsigned char parity;

	for (i = 0; i < 8; i++) {
		parity = key[i];

		parity ^= parity >> 4;
		parity ^= parity >> 2;
		parity ^= parity >> 1;

		key[i] = (key[i] & 0xfe) | (parity & 1);
	}
}

#define byteswap32(x) (TDS_UINT) (((x) & 0xff000000) >> 24 | \
				  ((x) & 0x00ff0000) >> 8 | \
				  ((x) & 0x0000ff00) << 8 | \
				  ((x) & 0x000000ff) << 24)

/* Tables defined in the Data Encryption Standard documents */

/* initial permutation IP */
static const char ip[] = {
	58, 50, 42, 34, 26, 18, 10, 2,
	60, 52, 44, 36, 28, 20, 12, 4,
	62, 54, 46, 38, 30, 22, 14, 6,
	64, 56, 48, 40, 32, 24, 16, 8,
	57, 49, 41, 33, 25, 17, 9, 1,
	59, 51, 43, 35, 27, 19, 11, 3,
	61, 53, 45, 37, 29, 21, 13, 5,
	63, 55, 47, 39, 31, 23, 15, 7
};

/* final permutation IP^-1 */
static const char fp[] = {
	40, 8, 48, 16, 56, 24, 64, 32,
	39, 7, 47, 15, 55, 23, 63, 31,
	38, 6, 46, 14, 54, 22, 62, 30,
	37, 5, 45, 13, 53, 21, 61, 29,
	36, 4, 44, 12, 52, 20, 60, 28,
	35, 3, 43, 11, 51, 19, 59, 27,
	34, 2, 42, 10, 50, 18, 58, 26,
	33, 1, 41, 9, 49, 17, 57, 25
};

/* expansion operation matrix
 * This is for reference only; it is unused in the code
 * as the f() function performs it implicitly for speed
 */
#ifdef notdef
static char ei[] = {
	32, 1, 2, 3, 4, 5,
	4, 5, 6, 7, 8, 9,
	8, 9, 10, 11, 12, 13,
	12, 13, 14, 15, 16, 17,
	16, 17, 18, 19, 20, 21,
	20, 21, 22, 23, 24, 25,
	24, 25, 26, 27, 28, 29,
	28, 29, 30, 31, 32, 1
};
#endif

/* permuted choice table (key) */
static const char pc1[] = {
	57, 49, 41, 33, 25, 17, 9,
	1, 58, 50, 42, 34, 26, 18,
	10, 2, 59, 51, 43, 35, 27,
	19, 11, 3, 60, 52, 44, 36,

	63, 55, 47, 39, 31, 23, 15,
	7, 62, 54, 46, 38, 30, 22,
	14, 6, 61, 53, 45, 37, 29,
	21, 13, 5, 28, 20, 12, 4
};

/* number left rotations of pc1 */
static const char totrot[] = {
	1, 2, 4, 6, 8, 10, 12, 14, 15, 17, 19, 21, 23, 25, 27, 28
};

/* permuted choice key (table) */
static const char pc2[] = {
	14, 17, 11, 24, 1, 5,
	3, 28, 15, 6, 21, 10,
	23, 19, 12, 4, 26, 8,
	16, 7, 27, 20, 13, 2,
	41, 52, 31, 37, 47, 55,
	30, 40, 51, 45, 33, 48,
	44, 49, 39, 56, 34, 53,
	46, 42, 50, 36, 29, 32
};

/* The (in)famous S-boxes */
static const char si[8][64] = {
	/* S1 */
	{14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
	 0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
	 4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
	 15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13},

	/* S2 */
	{15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
	 3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
	 0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
	 13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9},

	/* S3 */
	{10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
	 13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
	 13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
	 1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12},

	/* S4 */
	{7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
	 13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
	 10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
	 3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14},

	/* S5 */
	{2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
	 14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
	 4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
	 11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3},

	/* S6 */
	{12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
	 10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
	 9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
	 4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13},

	/* S7 */
	{4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
	 13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
	 1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
	 6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12},

	/* S8 */
	{13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
	 1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
	 7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
	 2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11},

};

/* 32-bit permutation function P used on the output of the S-boxes */
static const char p32i[] = {
	16, 7, 20, 21,
	29, 12, 28, 17,
	1, 15, 23, 26,
	5, 18, 31, 10,
	2, 8, 24, 14,
	32, 27, 3, 9,
	19, 13, 30, 6,
	22, 11, 4, 25
};

/* End of DES-defined tables */

/* Lookup tables initialized once only at startup by des_init() */

/* bit 0 is left-most in byte */
static const int bytebit[] = {
	0200, 0100, 040, 020, 010, 04, 02, 01
};

static const int nibblebit[] = {
	010, 04, 02, 01
};

/* Allocate space and initialize DES lookup arrays
 * mode == 0: standard Data Encryption Algorithm
 */
static int
des_init(DES_KEY * key)
{

	spinit(key);
	perminit_ip(key);
	perminit_fp(key);

	return 0;
}


/* Set key (initialize key schedule array) */
int
tds_des_set_key(DES_KEY * dkey, des_cblock user_key, int len)
{
	char pc1m[56];		/* place to modify pc1 into */
	char pcr[56];		/* place to rotate pc1 into */
	register int i, j, l;
	int m;

	memset(dkey, '\0', sizeof(DES_KEY));
	des_init(dkey);

	/* Clear key schedule */


	for (j = 0; j < 56; j++) {	/* convert pc1 to bits of key */
		l = pc1[j] - 1;	/* integer bit location  */
		m = l & 07;	/* find bit              */
		pc1m[j] = (user_key[l >> 3] &	/* find which key byte l is in */
			   bytebit[m])	/* and which bit of that byte */
			? 1 : 0;	/* and store 1-bit result */

	}
	for (i = 0; i < 16; i++) {	/* key chunk for each iteration */
		for (j = 0; j < 56; j++)	/* rotate pc1 the right amount */
			pcr[j] = pc1m[(l = j + totrot[i]) < (j < 28 ? 28 : 56) ? l : l - 28];
		/* rotate left and right halves independently */
		for (j = 0; j < 48; j++) {	/* select bits individually */
			/* check bit that goes to kn[j] */
			if (pcr[pc2[j] - 1]) {
				/* mask it in if it's there */
				l = j % 6;
				dkey->kn[i][j / 6] |= bytebit[l] >> 2;
			}
		}
	}
	return 0;
}

/* In-place encryption of 64-bit block */
void
tds_des_encrypt(DES_KEY * key, des_cblock block)
{
	register TDS_UINT left, right;
	register unsigned char *knp;
	TDS_UINT work[2];	/* Working data storage */

	permute_ip(block, key, (unsigned char *) work);	/* Initial Permutation */
#ifndef	WORDS_BIGENDIAN
	left = byteswap32(work[0]);
	right = byteswap32(work[1]);
#else
	left = work[0];
	right = work[1];
#endif

	/* Do the 16 rounds.
	 * The rounds are numbered from 0 to 15. On even rounds
	 * the right half is fed to f() and the result exclusive-ORs
	 * the left half; on odd rounds the reverse is done.
	 */
	knp = &key->kn[0][0];
	left ^= f(key, right, knp);
	knp += 8;
	right ^= f(key, left, knp);
	knp += 8;
	left ^= f(key, right, knp);
	knp += 8;
	right ^= f(key, left, knp);
	knp += 8;