* Copyright (c) 1991, 1993

/* $NetBSD: bdes.c,v 1.11 2023/06/27 19:30:27 andvar Exp $ */

/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Matt Bishop of Dartmouth College.
*
* The United States Government has rights in this work pursuant
* to contract no. NAG 2-680 between the National Aeronautics and
* Space Administration and Dartmouth College.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1991, 1993\
The Regents of the University of California. All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)bdes.c 8.1 (Berkeley) 6/6/93";
#else
__RCSID("$NetBSD: bdes.c,v 1.11 2023/06/27 19:30:27 andvar Exp $");
#endif
#endif /* not lint */

/*
* BDES -- DES encryption package for Berkeley Software Distribution 4.4
* options:
* -a key is in ASCII
* -b use ECB (electronic code book) mode
* -d invert (decrypt) input
* -f b use b-bit CFB (cipher feedback) mode
* -F b use b-bit CFB (cipher feedback) alternative mode
* -k key use key as the cryptographic key
* -m b generate a MAC of length b
* -o b use b-bit OFB (output feedback) mode
* -p don't reset the parity bit
* -v v use v as the initialization vector (ignored for ECB)
* note: the last character of the last block is the integer indicating
* how many characters of that block are to be output
*
* Author: Matt Bishop
* Department of Mathematics and Computer Science
* Dartmouth College
* Hanover, NH 03755
* Email: [email protected]
* ...!decvax!dartvax!Matt.Bishop
*
* See Technical Report PCS-TR91-158, Department of Mathematics and Computer
* Science, Dartmouth College, for a detailed description of the implemen-
* tation and differences between it and Sun's. The DES is described in
* FIPS PUB 46, and the modes in FIPS PUB 81 (see either the manual page
* or the technical report for a complete reference).
*/

#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>

/*
* BSD and System V systems offer special library calls that do
* block moves and fills, so if possible we take advantage of them
*/
#define MEMCPY(dest,src,len) bcopy((src),(dest),(len))
#define MEMZERO(dest,len) bzero((dest),(len))

/* Hide the calls to the primitive encryption routines. */
#define FASTWAY
#ifdef FASTWAY
#define DES_KEY(buf) \
if (des_setkey(buf)) \
bdes_err(0, "des_setkey");
#define DES_XFORM(buf) \
if (des_cipher(buf, buf, 0L, (inverse ? -1 : 1))) \
bdes_err(0, "des_cipher");
#else
#define DES_KEY(buf) { \
char bits1[64]; /* bits of key */ \
expand(buf, bits1); \
if (setkey(bits1)) \
bdes_err(0, "setkey"); \
}
#define DES_XFORM(buf) { \
char bits1[64]; /* bits of message */ \
expand(buf, bits1); \
if (encrypt(bits1, inverse)) \
bdes_err(0, "encrypt"); \
compress(bits1, buf); \
}
#endif

/*
* this does an error-checking write
*/
#define READ(buf, n) fread(buf, sizeof(char), n, stdin)
#define WRITE(buf,n) \
if (fwrite(buf, sizeof(char), n, stdout) != (size_t)n) \
bdes_err(bn, NULL);

/*
* some things to make references easier
*/
typedef char Desbuf[8];
#define CHAR(x,i) (x[i])
#define UCHAR(x,i) (x[i])
#define BUFFER(x) (x)
#define UBUFFER(x) (x)

/*
* global variables and related macros
*/
#define KEY_DEFAULT 0 /* interpret radix of key from key */
#define KEY_ASCII 1 /* key is in ASCII characters */
static int keybase = KEY_DEFAULT; /* how to interpret the key */

static enum { /* encrypt, decrypt, authenticate */
MODE_ENCRYPT, MODE_DECRYPT, MODE_AUTHENTICATE
} mode = MODE_ENCRYPT;
static enum { /* ecb, cbc, cfb, cfba, ofb? */
ALG_ECB, ALG_CBC, ALG_CFB, ALG_OFB, ALG_CFBA
} alg = ALG_CBC;

static Desbuf ivec; /* initialization vector */
static const char bits[] = { /* used to extract bits from a char */
'\200', '\100', '\040', '\020', '\010', '\004', '\002', '\001'
};
static int inverse; /* 0 to encrypt, 1 to decrypt */
static int macbits = -1; /* number of bits in authentication */
static int fbbits = -1; /* number of feedback bits */
static int pflag; /* 1 to preserve parity bits */

static int setbits(char *, int);
static void bdes_err(int, const char *) __dead;
static int tobinhex(char, int);
static void cvtkey(char *, char *);
static void makekey(Desbuf);
static void ecbenc(void);
static void ecbdec(void);
static void cbcenc(void);
static void cbcdec(void);
static void cbcauth(void);
static void cfbenc(void);
static void cfbdec(void);
static void cfbaenc(void);
static void cfbadec(void);
static void ofbenc(void);
static void ofbdec(void);
static void cfbauth(void);
#ifndef FASTWAY
static void expand(Desbuf, char *);
static void compress(char *, Desbuf);
#endif
static void usage(void) __dead;

int
main(int ac, char *av[])
{
register int i; /* counter in a for loop */
register char *p; /* used to obtain the key */
Desbuf msgbuf; /* I/O buffer */
int kflag; /* command-line encryption key */
int argc; /* the real arg count */
char **argv; /* the real argument vector */

/*
* Hide the arguments from ps(1) by making private copies of them
* and clobbering the global (visible to ps(1)) ones.
*/
argc = ac;
ac = 1;
argv = malloc((argc + 1) * sizeof(char *));
for (i = 0; i < argc; ++i) {
argv[i] = strdup(av[i]);
MEMZERO(av[i], strlen(av[i]));
}
argv[argc] = NULL;

/* initialize the initialization vctor */
MEMZERO(ivec, 8);

/* process the argument list */
kflag = 0;
while ((i = getopt(argc, argv, "abdF:f:k:m:o:pv:")) != -1)
switch(i) {
case 'a': /* key is ASCII */
keybase = KEY_ASCII;
break;
case 'b': /* use ECB mode */
alg = ALG_ECB;
break;
case 'd': /* decrypt */
mode = MODE_DECRYPT;
break;
case 'F': /* use alternative CFB mode */
alg = ALG_CFBA;
if ((fbbits = setbits(optarg, 7)) > 56 || fbbits == 0)
bdes_err(-1,
"-F: number must be 1-56 inclusive");
else if (fbbits == -1)
bdes_err(-1,
"-F: number must be a multiple of 7");
break;
case 'f': /* use CFB mode */
alg = ALG_CFB;
if ((fbbits = setbits(optarg, 8)) > 64 || fbbits == 0)
bdes_err(-1,
"-f: number must be 1-64 inclusive");
else if (fbbits == -1)
bdes_err(-1,
"-f: number must be a multiple of 8");
break;
case 'k': /* encryption key */
kflag = 1;
cvtkey(BUFFER(msgbuf), optarg);
break;
case 'm': /* number of bits for MACing */
mode = MODE_AUTHENTICATE;
if ((macbits = setbits(optarg, 1)) > 64)
bdes_err(-1,
"-m: number must be 0-64 inclusive");
break;
case 'o': /* use OFB mode */
alg = ALG_OFB;
if ((fbbits = setbits(optarg, 8)) > 64 || fbbits == 0)
bdes_err(-1,
"-o: number must be 1-64 inclusive");
else if (fbbits == -1)
bdes_err(-1,
"-o: number must be a multiple of 8");
break;
case 'p': /* preserve parity bits */
pflag = 1;
break;
case 'v': /* set initialization vector */
cvtkey(BUFFER(ivec), optarg);
break;
default: /* error */
usage();
}

if (!kflag) {
/*
* if the key's not ASCII, assume it is
*/
keybase = KEY_ASCII;
/*
* get the key
*/
p = getpass("Enter key: ");
/*
* copy it, nul-padded, into the key area
*/
cvtkey(BUFFER(msgbuf), p);
}

makekey(msgbuf);
inverse = (alg == ALG_CBC || alg == ALG_ECB) && mode == MODE_DECRYPT;

switch(alg) {
case ALG_CBC:
switch(mode) {
case MODE_AUTHENTICATE: /* authenticate using CBC mode */
cbcauth();
break;
case MODE_DECRYPT: /* decrypt using CBC mode */
cbcdec();
break;
case MODE_ENCRYPT: /* encrypt using CBC mode */
cbcenc();
break;
}
break;
case ALG_CFB:
switch(mode) {
case MODE_AUTHENTICATE: /* authenticate using CFB mode */
cfbauth();
break;
case MODE_DECRYPT: /* decrypt using CFB mode */
cfbdec();
break;
case MODE_ENCRYPT: /* encrypt using CFB mode */
cfbenc();
break;
}
break;
case ALG_CFBA:
switch(mode) {
case MODE_AUTHENTICATE: /* authenticate using CFBA mode */
bdes_err(-1, "can't authenticate with CFBA mode");
break;
case MODE_DECRYPT: /* decrypt using CFBA mode */
cfbadec();
break;
case MODE_ENCRYPT: /* encrypt using CFBA mode */
cfbaenc();
break;
}
break;
case ALG_ECB:
switch(mode) {
case MODE_AUTHENTICATE: /* authenticate using ECB mode */
bdes_err(-1, "can't authenticate with ECB mode");
break;
case MODE_DECRYPT: /* decrypt using ECB mode */
ecbdec();
break;
case MODE_ENCRYPT: /* encrypt using ECB mode */
ecbenc();
break;
}
break;
case ALG_OFB:
switch(mode) {
case MODE_AUTHENTICATE: /* authenticate using OFB mode */
bdes_err(-1, "can't authenticate with OFB mode");
break;
case MODE_DECRYPT: /* decrypt using OFB mode */
ofbdec();
break;
case MODE_ENCRYPT: /* encrypt using OFB mode */
ofbenc();
break;
}
break;
}
exit(0);
}

/*
* print a warning message and, possibly, terminate
*/
static void
bdes_err(int n, const char *s)
{
if (n > 0)
(void)fprintf(stderr, "bdes (block %d): ", n);
else
(void)fprintf(stderr, "bdes: ");
(void)fprintf(stderr, "%s\n", s ? s : strerror(errno));
exit(1);
}

/*
* map a hex character to an integer
*/
static int
tobinhex(char c, int radix)
{
switch(c) {
case '0': return(0x0);
case '1': return(0x1);
case '2': return(radix > 2 ? 0x2 : -1);
case '3': return(radix > 3 ? 0x3 : -1);
case '4': return(radix > 4 ? 0x4 : -1);
case '5': return(radix > 5 ? 0x5 : -1);
case '6': return(radix > 6 ? 0x6 : -1);
case '7': return(radix > 7 ? 0x7 : -1);
case '8': return(radix > 8 ? 0x8 : -1);
case '9': return(radix > 9 ? 0x9 : -1);
case 'A': case 'a': return(radix > 10 ? 0xa : -1);
case 'B': case 'b': return(radix > 11 ? 0xb : -1);
case 'C': case 'c': return(radix > 12 ? 0xc : -1);
case 'D': case 'd': return(radix > 13 ? 0xd : -1);
case 'E': case 'e': return(radix > 14 ? 0xe : -1);
case 'F': case 'f': return(radix > 15 ? 0xf : -1);
}
/*
* invalid character
*/
return(-1);
}

/*
* convert the key to a bit pattern
*/
static void
cvtkey(char *obuf, char *ibuf)
{
register int i, j; /* counter in a for loop */
int nbuf[64]; /* used for hex/key translation */

/*
* just switch on the key base
*/
switch(keybase) {
case KEY_ASCII: /* ascii to integer */
(void)strncpy(obuf, ibuf, 8);
return;
case KEY_DEFAULT: /* tell from context */
/*
* leading '0x' or '0X' == hex key
*/
if (ibuf[0] == '0' && (ibuf[1] == 'x' || ibuf[1] == 'X')) {
ibuf = &ibuf[2];
/*
* now translate it, bombing on any illegal hex digit
*/
for (i = 0; i < 16 && ibuf[i]; i++)
if ((nbuf[i] = tobinhex(ibuf[i], 16)) == -1)
bdes_err(-1, "bad hex digit in key");
while (i < 16)
nbuf[i++] = 0;
for (i = 0; i < 8; i++)
obuf[i] =
((nbuf[2*i]&0xf)<<4) | (nbuf[2*i+1]&0xf);
/* preserve parity bits */
pflag = 1;
return;
}
/*
* leading '0b' or '0B' == binary key
*/
if (ibuf[0] == '0' && (ibuf[1] == 'b' || ibuf[1] == 'B')) {
ibuf = &ibuf[2];
/*
* now translate it, bombing on any illegal binary digit
*/
for (i = 0; ibuf[i] && i < 16; i++)
if ((nbuf[i] = tobinhex(ibuf[i], 2)) == -1)
bdes_err(-1, "bad binary digit in key");
while (i < 64)
nbuf[i++] = 0;
for (i = 0; i < 8; i++)
for (j = 0; j < 8; j++)
obuf[i] = (obuf[i]<<1)|nbuf[8*i+j];
/* preserve parity bits */
pflag = 1;
return;
}
/*
* no special leader -- ASCII
*/
(void)strncpy(obuf, ibuf, 8);
}
}

/*
* convert an ASCII string into a decimal number:
* 1. must be between 0 and 64 inclusive (or 56, checked by caller)
* 2. must be a valid decimal number
* 3. must be a multiple of mult
*/
static int
setbits(char *s, int mult)
{
char *p;
int n; /* the integer collected */

n = strtoul(s, &p, 10);
if (*p != 0)
bdes_err(-1, "bad decimal digit in MAC length");
/*
* be sure it's a multiple of mult
*/
return((n % mult != 0) ? -1 : n);
}

/*****************
* DES FUNCTIONS *
*****************/
/*
* This sets the DES key and (if you're using the deszip version)
* the direction of the transformation. This uses the Sun
* to map the 64-bit key onto the 56 bits that the key schedule
* generation routines use: the old way, which just uses the user-
* supplied 64 bits as is, and the new way, which resets the parity
* bit to be the same as the low-order bit in each character. The
* new way generates a greater variety of key schedules, since many
* systems set the parity (high) bit of each character to 0, and the
* DES ignores the low order bit of each character.
*/
static void
makekey(Desbuf buf)
{
register int i, j; /* counter in a for loop */
register int par; /* parity counter */

/*
* if the parity is not preserved, flip it
*/
if (!pflag) {
for (i = 0; i < 8; i++) {
par = 0;
for (j = 1; j < 8; j++)
if ((bits[j]&UCHAR(buf, i)) != 0)
par++;
if ((par&01) == 01)
UCHAR(buf, i) = UCHAR(buf, i)&0177;
else
UCHAR(buf, i) = (UCHAR(buf, i)&0177)|0200;
}
}

DES_KEY(UBUFFER(buf));
}

/*
* This encrypts using the Electronic Code Book mode of DES
*/
static void
ecbenc(void)
{
register int n; /* number of bytes actually read */
register int bn; /* block number */
Desbuf msgbuf; /* I/O buffer */

for (bn = 0; (n = READ(BUFFER(msgbuf), 8)) == 8; bn++) {
/*
* do the transformation
*/
DES_XFORM(UBUFFER(msgbuf));
WRITE(BUFFER(msgbuf), 8);
}
/*
* at EOF or last block -- in either ase, the last byte contains
* the character representation of the number of bytes in it
*/
bn++;
MEMZERO(&CHAR(msgbuf, n), 8 - n);
CHAR(msgbuf, 7) = n;
DES_XFORM(UBUFFER(msgbuf));
WRITE(BUFFER(msgbuf), 8);

}

/*
* This decrypts using the Electronic Code Book mode of DES
*/
static void
ecbdec(void)
{
register int n; /* number of bytes actually read */
register int c; /* used to test for EOF */
register int bn; /* block number */
Desbuf msgbuf; /* I/O buffer */

for (bn = 1; (n = READ(BUFFER(msgbuf), 8)) == 8; bn++) {
/*
* do the transformation
*/
DES_XFORM(UBUFFER(msgbuf));
/*
* if the last one, handle it specially
*/
if ((c = getchar()) == EOF) {
n = CHAR(msgbuf, 7);
if (n < 0 || n > 7)
bdes_err(bn,
"decryption failed (block corrupted)");
}
else
(void)ungetc(c, stdin);
WRITE(BUFFER(msgbuf), n);
}
if (n > 0)
bdes_err(bn, "decryption failed (incomplete block)");
}

/*
* This encrypts using the Cipher Block Chaining mode of DES
*/
static void
cbcenc(void)
{
register int n; /* number of bytes actually read */
register int bn; /* block number */
Desbuf msgbuf; /* I/O buffer */

/*
* do the transformation
*/
for (bn = 1; (n = READ(BUFFER(msgbuf), 8)) == 8; bn++) {
for (n = 0; n < 8; n++)
CHAR(msgbuf, n) ^= CHAR(ivec, n);
DES_XFORM(UBUFFER(msgbuf));
MEMCPY(BUFFER(ivec), BUFFER(msgbuf), 8);
WRITE(BUFFER(msgbuf), 8);
}
/*
* at EOF or last block -- in either case, the last byte contains
* the character representation of the number of bytes in it
*/
bn++;
MEMZERO(&CHAR(msgbuf, n), 8 - n);
CHAR(msgbuf, 7) = n;
for (n = 0; n < 8; n++)
CHAR(msgbuf, n) ^= CHAR(ivec, n);
DES_XFORM(UBUFFER(msgbuf));
WRITE(BUFFER(msgbuf), 8);

}

/*
* This decrypts using the Cipher Block Chaining mode of DES
*/
static void
cbcdec(void)
{
register int n; /* number of bytes actually read */
Desbuf msgbuf; /* I/O buffer */
Desbuf ibuf; /* temp buffer for initialization vector */
register int c; /* used to test for EOF */
register int bn; /* block number */

for (bn = 0; (n = READ(BUFFER(msgbuf), 8)) == 8; bn++) {
/*
* do the transformation
*/
MEMCPY(BUFFER(ibuf), BUFFER(msgbuf), 8);
DES_XFORM(UBUFFER(msgbuf));
for (c = 0; c < 8; c++)
UCHAR(msgbuf, c) ^= UCHAR(ivec, c);
MEMCPY(BUFFER(ivec), BUFFER(ibuf), 8);
/*
* if the last one, handle it specially
*/
if ((c = getchar()) == EOF) {
n = CHAR(msgbuf, 7);
if (n < 0 || n > 7)
bdes_err(bn,
"decryption failed (block corrupted)");
}
else
(void)ungetc(c, stdin);
WRITE(BUFFER(msgbuf), n);
}
if (n > 0)
bdes_err(bn, "decryption failed (incomplete block)");
}

/*
* This authenticates using the Cipher Block Chaining mode of DES
*/
static void
cbcauth(void)
{
register int n, j; /* number of bytes actually read */
Desbuf msgbuf; /* I/O buffer */
Desbuf encbuf; /* encryption buffer */

/*
* do the transformation
* note we DISCARD the encrypted block;
* we only care about the last one
*/
while ((n = READ(BUFFER(msgbuf), 8)) == 8) {
for (n = 0; n < 8; n++)
CHAR(encbuf, n) = CHAR(msgbuf, n) ^ CHAR(ivec, n);
DES_XFORM(UBUFFER(encbuf));
MEMCPY(BUFFER(ivec), BUFFER(encbuf), 8);
}
/*
* now compute the last one, right padding with '\0' if need be
*/
if (n > 0) {
MEMZERO(&CHAR(msgbuf, n), 8 - n);
for (n = 0; n < 8; n++)
CHAR(encbuf, n) = CHAR(msgbuf, n) ^ CHAR(ivec, n);
DES_XFORM(UBUFFER(encbuf));
}
/*
* drop the bits
* we write chars until fewer than 7 bits,
* and then pad the last one with 0 bits
*/
for (n = 0; macbits > 7; n++, macbits -= 8)
(void)putchar(CHAR(encbuf, n));
if (macbits > 0) {
CHAR(msgbuf, 0) = 0x00;
for (j = 0; j < macbits; j++)
CHAR(msgbuf, 0) |= (CHAR(encbuf, n)&bits[j]);
(void)putchar(CHAR(msgbuf, 0));
}
}

/*
* This encrypts using the Cipher FeedBack mode of DES
*/
static void
cfbenc(void)
{
register int n; /* number of bytes actually read */
register int nbytes; /* number of bytes to read */
register int bn; /* block number */
char ibuf[8]; /* input buffer */
Desbuf msgbuf; /* encryption buffer */

/*
* do things in bytes, not bits
*/
nbytes = fbbits / 8;
/*
* do the transformation
*/
for (bn = 1; (n = READ(ibuf, nbytes)) == nbytes; bn++) {
MEMCPY(BUFFER(msgbuf), BUFFER(ivec), 8);
DES_XFORM(UBUFFER(msgbuf));
for (n = 0; n < 8 - nbytes; n++)
UCHAR(ivec, n) = UCHAR(ivec, n+nbytes);
for (n = 0; n < nbytes; n++)
UCHAR(ivec, 8-nbytes+n) = ibuf[n] ^ UCHAR(msgbuf, n);
WRITE(&CHAR(ivec, 8-nbytes), nbytes);
}
/*
* at EOF or last block -- in either case, the last byte contains
* the character representation of the number of bytes in it
*/
bn++;
MEMZERO(&ibuf[n], nbytes - n);
ibuf[nbytes - 1] = n;
MEMCPY(BUFFER(msgbuf), BUFFER(ivec), 8);
DES_XFORM(UBUFFER(msgbuf));
for (n = 0; n < nbytes; n++)
ibuf[n] ^= UCHAR(msgbuf, n);
WRITE(ibuf, nbytes);
}

/*
* This decrypts using the Cipher Block Chaining mode of DES
*/
static void
cfbdec(void)
{
register int n; /* number of bytes actually read */
register int c; /* used to test for EOF */
register int nbytes; /* number of bytes to read */
register int bn; /* block number */
char ibuf[8]; /* input buffer */
char obuf[8]; /* output buffer */
Desbuf msgbuf; /* encryption buffer */

/*
* do things in bytes, not bits
*/
nbytes = fbbits / 8;
/*
* do the transformation
*/
for (bn = 1; (n = READ(ibuf, nbytes)) == nbytes; bn++) {
MEMCPY(BUFFER(msgbuf), BUFFER(ivec), 8);
DES_XFORM(UBUFFER(msgbuf));
for (c = 0; c < 8 - nbytes; c++)
CHAR(ivec, c) = CHAR(ivec, c+nbytes);
for (c = 0; c < nbytes; c++) {
CHAR(ivec, 8-nbytes+c) = ibuf[c];
obuf[c] = ibuf[c] ^ UCHAR(msgbuf, c);
}
/*
* if the last one, handle it specially
*/
if ((c = getchar()) == EOF) {
n = obuf[nbytes-1];
if (n < 0 || n > nbytes-1)
bdes_err(bn,
"decryption failed (block corrupted)");
}
else
(void)ungetc(c, stdin);
WRITE(obuf, n);
}
if (n > 0)
bdes_err(bn, "decryption failed (incomplete block)");
}

/*
* This encrypts using the alternative Cipher FeedBack mode of DES
*/
static void
cfbaenc(void)
{
register int n; /* number of bytes actually read */
register int nbytes; /* number of bytes to read */
register int bn; /* block number */
char ibuf[8]; /* input buffer */
char obuf[8]; /* output buffer */
Desbuf msgbuf; /* encryption buffer */

/*
* do things in bytes, not bits
*/
nbytes = fbbits / 7;
/*
* do the transformation
*/
for (bn = 1; (n = READ(ibuf, nbytes)) == nbytes; bn++) {
MEMCPY(BUFFER(msgbuf), BUFFER(ivec), 8);
DES_XFORM(UBUFFER(msgbuf));
for (n = 0; n < 8 - nbytes; n++)
UCHAR(ivec, n) = UCHAR(ivec, n+nbytes);
for (n = 0; n < nbytes; n++)
UCHAR(ivec, 8-nbytes+n) = (ibuf[n] ^ UCHAR(msgbuf, n))
|0200;
for (n = 0; n < nbytes; n++)
obuf[n] = CHAR(ivec, 8-nbytes+n)&0177;
WRITE(obuf, nbytes);
}
/*
* at EOF or last block -- in either case, the last byte contains
* the character representation of the number of bytes in it
*/
bn++;
MEMZERO(&ibuf[n], nbytes - n);
ibuf[nbytes - 1] = ('0' + n)|0200;
MEMCPY(BUFFER(msgbuf), BUFFER(ivec), 8);
DES_XFORM(UBUFFER(msgbuf));
for (n = 0; n < nbytes; n++)
ibuf[n] ^= UCHAR(msgbuf, n);
WRITE(ibuf, nbytes);
}

/*
* This decrypts using the alternative Cipher Block Chaining mode of DES
*/
static void
cfbadec(void)
{
register int n; /* number of bytes actually read */
register int c; /* used to test for EOF */
register int nbytes; /* number of bytes to read */
register int bn; /* block number */
char ibuf[8]; /* input buffer */
char obuf[8]; /* output buffer */
Desbuf msgbuf; /* encryption buffer */

/*
* do things in bytes, not bits
*/
nbytes = fbbits / 7;
/*
* do the transformation
*/
for (bn = 1; (n = READ(ibuf, nbytes)) == nbytes; bn++) {
MEMCPY(BUFFER(msgbuf), BUFFER(ivec), 8);
DES_XFORM(UBUFFER(msgbuf));
for (c = 0; c < 8 - nbytes; c++)
CHAR(ivec, c) = CHAR(ivec, c+nbytes);
for (c = 0; c < nbytes; c++) {
CHAR(ivec, 8-nbytes+c) = ibuf[c]|0200;
obuf[c] = (ibuf[c] ^ UCHAR(msgbuf, c))&0177;
}
/*
* if the last one, handle it specially
*/
if ((c = getchar()) == EOF) {
if ((n = (obuf[nbytes-1] - '0')) < 0
|| n > nbytes-1)
bdes_err(bn,
"decryption failed (block corrupted)");
}
else
(void)ungetc(c, stdin);
WRITE(obuf, n);
}
if (n > 0)
bdes_err(bn, "decryption failed (incomplete block)");
}

/*
* This encrypts using the Output FeedBack mode of DES
*/
static void
ofbenc(void)
{
register int n; /* number of bytes actually read */
register int c; /* used to test for EOF */
register int nbytes; /* number of bytes to read */
register int bn; /* block number */
char ibuf[8]; /* input buffer */
char obuf[8]; /* output buffer */
Desbuf msgbuf; /* encryption buffer */

/*
* do things in bytes, not bits
*/
nbytes = fbbits / 8;
/*
* do the transformation
*/
for (bn = 1; (n = READ(ibuf, nbytes)) == nbytes; bn++) {
MEMCPY(BUFFER(msgbuf), BUFFER(ivec), 8);
DES_XFORM(UBUFFER(msgbuf));
for (n = 0; n < 8 - nbytes; n++)
UCHAR(ivec, n) = UCHAR(ivec, n+nbytes);
for (n = 0; n < nbytes; n++) {
UCHAR(ivec, 8-nbytes+n) = UCHAR(msgbuf, n);
obuf[n] = ibuf[n] ^ UCHAR(msgbuf, n);
}
WRITE(obuf, nbytes);
}
/*
* at EOF or last block -- in either case, the last byte contains
* the character representation of the number of bytes in it
*/
bn++;
MEMZERO(&ibuf[n], nbytes - n);
ibuf[nbytes - 1] = n;
MEMCPY(BUFFER(msgbuf), BUFFER(ivec), 8);
DES_XFORM(UBUFFER(msgbuf));
for (c = 0; c < nbytes; c++)
ibuf[c] ^= UCHAR(msgbuf, c);
WRITE(ibuf, nbytes);
}

/*
* This decrypts using the Output Block Chaining mode of DES
*/
static void
ofbdec(void)
{
register int n; /* number of bytes actually read */
register int c; /* used to test for EOF */
register int nbytes; /* number of bytes to read */
register int bn; /* block number */
char ibuf[8]; /* input buffer */
char obuf[8]; /* output buffer */
Desbuf msgbuf; /* encryption buffer */

/*
* do things in bytes, not bits
*/
nbytes = fbbits / 8;
/*
* do the transformation
*/
for (bn = 1; (n = READ(ibuf, nbytes)) == nbytes; bn++) {
MEMCPY(BUFFER(msgbuf), BUFFER(ivec), 8);
DES_XFORM(UBUFFER(msgbuf));
for (c = 0; c < 8 - nbytes; c++)
CHAR(ivec, c) = CHAR(ivec, c+nbytes);
for (c = 0; c < nbytes; c++) {
CHAR(ivec, 8-nbytes+c) = UCHAR(msgbuf, c);
obuf[c] = ibuf[c] ^ UCHAR(msgbuf, c);
}
/*
* if the last one, handle it specially
*/
if ((c = getchar()) == EOF) {
n = obuf[nbytes-1];
if (n < 0 || n > nbytes-1)
bdes_err(bn,
"decryption failed (block corrupted)");
}
else
(void)ungetc(c, stdin);
/*
* dump it
*/
WRITE(obuf, n);
}
if (n > 0)
bdes_err(bn, "decryption failed (incomplete block)");
}

/*
* This authenticates using the Cipher FeedBack mode of DES
*/
static void
cfbauth(void)
{
register int n, j; /* number of bytes actually read */
register int nbytes; /* number of bytes to read */
char ibuf[8]; /* input buffer */
Desbuf msgbuf; /* encryption buffer */

/*
* do things in bytes, not bits
*/
nbytes = fbbits / 8;
/*
* do the transformation
*/
while ((n = READ(ibuf, nbytes)) == nbytes) {
MEMCPY(BUFFER(msgbuf), BUFFER(ivec), 8);
DES_XFORM(UBUFFER(msgbuf));
for (n = 0; n < 8 - nbytes; n++)
UCHAR(ivec, n) = UCHAR(ivec, n+nbytes);
for (n = 0; n < nbytes; n++)
UCHAR(ivec, 8-nbytes+n) = ibuf[n] ^ UCHAR(msgbuf, n);
}
/*
* at EOF or last block -- in either case, the last byte contains
* the character representation of the number of bytes in it
*/
MEMZERO(&ibuf[n], nbytes - n);
ibuf[nbytes - 1] = '0' + n;
MEMCPY(BUFFER(msgbuf), BUFFER(ivec), 8);
DES_XFORM(UBUFFER(msgbuf));
for (n = 0; n < nbytes; n++)
ibuf[n] ^= UCHAR(msgbuf, n);
/*
* drop the bits
* we write chars until fewer than 7 bits,
* and then pad the last one with 0 bits
*/
for (n = 0; macbits > 7; n++, macbits -= 8)
(void)putchar(CHAR(msgbuf, n));
if (macbits > 0) {
CHAR(msgbuf, 0) = 0x00;
for (j = 0; j < macbits; j++)
CHAR(msgbuf, 0) |= (CHAR(msgbuf, n)&bits[j]);
(void)putchar(CHAR(msgbuf, 0));
}
}

#ifndef FASTWAY
/*
* change from 8 bits/Uchar to 1 bit/Uchar
*/
static void
expand(Desbuf from, char *to)
{
register int i, j; /* counters in for loop */

for (i = 0; i < 8; i++)
for (j = 0; j < 8; j++)
*to++ = (CHAR(from, i)>>(7-j))&01;
}

/*
* change from 1 bit/char to 8 bits/Uchar
*/
static void
compress(char *from, Desbuf to)
{
register int i, j; /* counters in for loop */

for (i = 0; i < 8; i++) {
CHAR(to, i) = 0;
for (j = 0; j < 8; j++)
CHAR(to, i) = ((*from++)<<(7-j))|CHAR(to, i);
}
}
#endif

/*
* message about usage
*/
static void
usage(void)
{

(void) fprintf(stderr, "usage: %s %s\n", getprogname(),
"[-abdp] [-F bit] [-f bit] [-k key] [-m bit] [-o bit] [-v vector]");
exit(1);
}