d3des.c

realvnc是一个非常流行的远程控制程序

/*
 * This is D3DES (V5.09) by Richard Outerbridge with the double and
 * triple-length support removed for use in VNC.  Also the bytebit[] array
 * has been reversed so that the most significant bit in each byte of the
 * key is ignored, not the least significant.
 *
 * These changes are
 * Copyright (C) 1999 AT&T Laboratories Cambridge. All Rights Reserved.
 *
 * This software 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.
 */

/* D3DES (V5.09) -
 *
 * A portable, public domain, version of the Data Encryption Standard.
 *
 * Written with Symantec's THINK (Lightspeed) C by Richard Outerbridge.
 * Thanks to: Dan Hoey for his excellent Initial and Inverse permutation
 * code;  Jim Gillogly & Phil Karn for the DES key schedule code; Dennis
 * Ferguson, Eric Young and Dana How for comparing notes; and Ray Lau,
 * for humouring me on.
 *
 * Copyright (c) 1988,1989,1990,1991,1992 by Richard Outerbridge.
 * (GEnie : OUTER; CIS : [71755,204]) Graven Imagery, 1992.
 */

#include "d3des.h"

static void scrunch(unsigned char *, unsigned long *);
static void unscrun(unsigned long *, unsigned char *);
static void desfunc(unsigned long *, unsigned long *);
static void cookey(unsigned long *);

static unsigned long KnL[32] = { 0L };
static unsigned long KnR[32] = { 0L };
static unsigned long Kn3[32] = { 0L };
static unsigned char Df_Key[24] = {
        0x01,0x23,0x45,0x67,0x89,0xab,0xcd,0xef,
        0xfe,0xdc,0xba,0x98,0x76,0x54,0x32,0x10,
        0x89,0xab,0xcd,0xef,0x01,0x23,0x45,0x67 };

static unsigned short bytebit[8]        = {
        01, 02, 04, 010, 020, 040, 0100, 0200 };

static unsigned long bigbyte[24] = {
        0x800000L,      0x400000L,      0x200000L,      0x100000L,
        0x80000L,       0x40000L,       0x20000L,       0x10000L,
        0x8000L,        0x4000L,        0x2000L,        0x1000L,
        0x800L,         0x400L,         0x200L,         0x100L,
        0x80L,          0x40L,          0x20L,          0x10L,
        0x8L,           0x4L,           0x2L,           0x1L    };

/* Use the key schedule specified in the Standard (ANSI X3.92-1981). */

static unsigned char pc1[56] = {
        56, 48, 40, 32, 24, 16,  8,      0, 57, 49, 41, 33, 25, 17,
         9,  1, 58, 50, 42, 34, 26,     18, 10,  2, 59, 51, 43, 35,
        62, 54, 46, 38, 30, 22, 14,      6, 61, 53, 45, 37, 29, 21,
        13,  5, 60, 52, 44, 36, 28,     20, 12,  4, 27, 19, 11,  3 };

static unsigned char totrot[16] = {
        1,2,4,6,8,10,12,14,15,17,19,21,23,25,27,28 };

static unsigned char pc2[48] = {
        13, 16, 10, 23,  0,  4,  2, 27, 14,  5, 20,  9,
        22, 18, 11,  3, 25,  7, 15,  6, 26, 19, 12,  1,
        40, 51, 30, 36, 46, 54, 29, 39, 50, 44, 32, 47,
        43, 48, 38, 55, 33, 52, 45, 41, 49, 35, 28, 31 };

void deskey(key, edf)   /* Thanks to James Gillogly & Phil Karn! */
unsigned char *key;
short edf;
{
        register int i, j, l, m, n;
        unsigned char pc1m[56], pcr[56];
        unsigned long kn[32];

        for ( j = 0; j < 56; j++ ) {
                l = pc1[j];
                m = l & 07;
                pc1m[j] = (key[l >> 3] & bytebit[m]) ? 1 : 0;
                }
        for( i = 0; i < 16; i++ ) {
                if( edf == DE1 ) m = (15 - i) << 1;
                else m = i << 1;
                n = m + 1;
                kn[m] = kn[n] = 0L;
                for( j = 0; j < 28; j++ ) {
                        l = j + totrot[i];
                        if( l < 28 ) pcr[j] = pc1m[l];
                        else pcr[j] = pc1m[l - 28];
                        }
                for( j = 28; j < 56; j++ ) {
                    l = j + totrot[i];
                    if( l < 56 ) pcr[j] = pc1m[l];
                    else pcr[j] = pc1m[l - 28];
                    }
                for( j = 0; j < 24; j++ ) {
                        if( pcr[pc2[j]] ) kn[m] |= bigbyte[j];
                        if( pcr[pc2[j+24]] ) kn[n] |= bigbyte[j];
                        }
                }
        cookey(kn);
        return;
        }

static void cookey(raw1)
register unsigned long *raw1;
{
        register unsigned long *cook, *raw0;
        unsigned long dough[32];
        register int i;

        cook = dough;
        for( i = 0; i < 16; i++, raw1++ ) {
                raw0 = raw1++;
                *cook    = (*raw0 & 0x00fc0000L) << 6;
                *cook   |= (*raw0 & 0x00000fc0L) << 10;
                *cook   |= (*raw1 & 0x00fc0000L) >> 10;
                *cook++ |= (*raw1 & 0x00000fc0L) >> 6;
                *cook    = (*raw0 & 0x0003f000L) << 12;
                *cook   |= (*raw0 & 0x0000003fL) << 16;
                *cook   |= (*raw1 & 0x0003f000L) >> 4;
                *cook++ |= (*raw1 & 0x0000003fL);
                }
        usekey(dough);
        return;
        }

void cpkey(into)
register unsigned long *into;
{
        register unsigned long *from, *endp;

        from = KnL, endp = &KnL[32];
        while( from < endp ) *into++ = *from++;
        return;
        }

void usekey(from)
register unsigned long *from;
{
        register unsigned long *to, *endp;

        to = KnL, endp = &KnL[32];
        while( to < endp ) *to++ = *from++;
        return;
        }

void des(inblock, outblock)
unsigned char *inblock, *outblock;
{
        unsigned long work[2];

        scrunch(inblock, work);
        desfunc(work, KnL);
        unscrun(work, outblock);
        return;
        }

static void scrunch(outof, into)
register unsigned char *outof;
register unsigned long *into;
{
        *into    = (*outof++ & 0xffL) << 24;
        *into   |= (*outof++ & 0xffL) << 16;
        *into   |= (*outof++ & 0xffL) << 8;
        *into++ |= (*outof++ & 0xffL);
        *into    = (*outof++ & 0xffL) << 24;
        *into   |= (*outof++ & 0xffL) << 16;
        *into   |= (*outof++ & 0xffL) << 8;
        *into   |= (*outof   & 0xffL);
        return;
        }

static void unscrun(outof, into)
register unsigned long *outof;
register unsigned char *into;
{
        *into++ = (unsigned char) ((*outof >> 24) & 0xffL);
        *into++ = (unsigned char) ((*outof >> 16) & 0xffL);
        *into++ = (unsigned char) ((*outof >>  8) & 0xffL);
        *into++ = (unsigned char)  (*outof++      & 0xffL);
        *into++ = (unsigned char) ((*outof >> 24) & 0xffL);
        *into++ = (unsigned char) ((*outof >> 16) & 0xffL);
        *into++ = (unsigned char) ((*outof >>  8) & 0xffL);
        *into   = (unsigned char)  (*outof        & 0xffL);
        return;
        }

static unsigned long SP1[64] = {
        0x01010400L, 0x00000000L, 0x00010000L, 0x01010404L,
        0x01010004L, 0x00010404L, 0x00000004L, 0x00010000L,
        0x00000400L, 0x01010400L, 0x01010404L, 0x00000400L,
        0x01000404L, 0x01010004L, 0x01000000L, 0x00000004L,
        0x00000404L, 0x01000400L, 0x01000400L, 0x00010400L,
        0x00010400L, 0x01010000L, 0x01010000L, 0x01000404L,
        0x00010004L, 0x01000004L, 0x01000004L, 0x00010004L,
        0x00000000L, 0x00000404L, 0x00010404L, 0x01000000L,
        0x00010000L, 0x01010404L, 0x00000004L, 0x01010000L,
        0x01010400L, 0x01000000L, 0x01000000L, 0x00000400L,
        0x01010004L, 0x00010000L, 0x00010400L, 0x01000004L,
        0x00000400L, 0x00000004L, 0x01000404L, 0x00010404L,
        0x01010404L, 0x00010004L, 0x01010000L, 0x01000404L,
        0x01000004L, 0x00000404L, 0x00010404L, 0x01010400L,
        0x00000404L, 0x01000400L, 0x01000400L, 0x00000000L,
        0x00010004L, 0x00010400L, 0x00000000L, 0x01010004L };

static unsigned long SP2[64] = {
        0x80108020L, 0x80008000L, 0x00008000L, 0x00108020L,
        0x00100000L, 0x00000020L, 0x80100020L, 0x80008020L,
        0x80000020L, 0x80108020L, 0x80108000L, 0x80000000L,
        0x80008000L, 0x00100000L, 0x00000020L, 0x80100020L,
        0x00108000L, 0x00100020L, 0x80008020L, 0x00000000L,
        0x80000000L, 0x00008000L, 0x00108020L, 0x80100000L,
        0x00100020L, 0x80000020L, 0x00000000L, 0x00108000L,
        0x00008020L, 0x80108000L, 0x80100000L, 0x00008020L,
        0x00000000L, 0x00108020L, 0x80100020L, 0x00100000L,
        0x80008020L, 0x80100000L, 0x80108000L, 0x00008000L,