NetBSD-5.0.2/lib/libtelnet/enc_des.c
/* $NetBSD: enc_des.c,v 1.13 2007/01/17 23:24:22 hubertf Exp $ */
/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* 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
#if 0
static char sccsid[] = "@(#)enc_des.c 8.3 (Berkeley) 5/30/95"; */
#else
__RCSID("$NetBSD: enc_des.c,v 1.13 2007/01/17 23:24:22 hubertf Exp $");
#endif
#endif /* not lint */
#ifdef ENCRYPTION
# ifdef AUTHENTICATION
# ifdef DES_ENCRYPTION
#include <arpa/telnet.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <des.h>
#include "encrypt.h"
#include "key-proto.h"
#include "misc-proto.h"
#define CFB 0
#define OFB 1
#define NO_SEND_IV 1
#define NO_RECV_IV 2
#define NO_KEYID 4
#define IN_PROGRESS (NO_SEND_IV|NO_RECV_IV|NO_KEYID)
#define SUCCESS 0
#define FAILED -1
struct fb {
Block krbdes_key;
Schedule krbdes_sched;
Block temp_feed;
unsigned char fb_feed[64];
int need_start;
int state[2];
int keyid[2];
int once;
struct stinfo {
Block str_output;
Block str_feed;
Block str_iv;
Block str_ikey;
Schedule str_sched;
int str_index;
int str_flagshift;
} streams[2];
};
static struct fb fb[2];
struct keyidlist {
char *keyid;
int keyidlen;
char *key;
int keylen;
int flags;
} keyidlist [] = {
{ "\0", 1, 0, 0, 0 }, /* default key of zero */
{ 0, 0, 0, 0, 0 }
};
#define KEYFLAG_MASK 03
#define KEYFLAG_NOINIT 00
#define KEYFLAG_INIT 01
#define KEYFLAG_OK 02
#define KEYFLAG_BAD 03
#define KEYFLAG_SHIFT 2
#define SHIFT_VAL(a,b) (KEYFLAG_SHIFT*((a)+((b)*2)))
#define FB64_IV 1
#define FB64_IV_OK 2
#define FB64_IV_BAD 3
void fb64_stream_iv(Block, struct stinfo *);
void fb64_init(struct fb *);
static int fb64_start(struct fb *, int, int);
int fb64_is(unsigned char *, int, struct fb *);
int fb64_reply(unsigned char *, int, struct fb *);
static void fb64_session(Session_Key *, int, struct fb *);
void fb64_stream_key(Block *, struct stinfo *);
int fb64_keyid(int, unsigned char *, int *, struct fb *);
void
cfb64_init(server)
int server;
{
fb64_init(&fb[CFB]);
fb[CFB].fb_feed[4] = ENCTYPE_DES_CFB64;
fb[CFB].streams[0].str_flagshift = SHIFT_VAL(0, CFB);
fb[CFB].streams[1].str_flagshift = SHIFT_VAL(1, CFB);
}
void
ofb64_init(server)
int server;
{
fb64_init(&fb[OFB]);
fb[OFB].fb_feed[4] = ENCTYPE_DES_OFB64;
fb[CFB].streams[0].str_flagshift = SHIFT_VAL(0, OFB);
fb[CFB].streams[1].str_flagshift = SHIFT_VAL(1, OFB);
}
void
fb64_init(fbp)
register struct fb *fbp;
{
memset((void *)fbp, 0, sizeof(*fbp));
fbp->state[0] = fbp->state[1] = FAILED;
fbp->fb_feed[0] = IAC;
fbp->fb_feed[1] = SB;
fbp->fb_feed[2] = TELOPT_ENCRYPT;
fbp->fb_feed[3] = ENCRYPT_IS;
}
/*
* Returns:
* -1: some error. Negotiation is done, encryption not ready.
* 0: Successful, initial negotiation all done.
* 1: successful, negotiation not done yet.
* 2: Not yet. Other things (like getting the key from
* Kerberos) have to happen before we can continue.
*/
int
cfb64_start(dir, server)
int dir;
int server;
{
return(fb64_start(&fb[CFB], dir, server));
}
int
ofb64_start(dir, server)
int dir;
int server;
{
return(fb64_start(&fb[OFB], dir, server));
}
static int
fb64_start(fbp, dir, server)
struct fb *fbp;
int dir;
int server;
{
int x;
unsigned char *p;
register int state;
switch (dir) {
case DIR_DECRYPT:
/*
* This is simply a request to have the other side
* start output (our input). He will negotiate an
* IV so we need not look for it.
*/
state = fbp->state[dir-1];
if (state == FAILED)
state = IN_PROGRESS;
break;
case DIR_ENCRYPT:
state = fbp->state[dir-1];
if (state == FAILED)
state = IN_PROGRESS;
else if ((state & NO_SEND_IV) == 0)
break;
if (!VALIDKEY(fbp->krbdes_key)) {
fbp->need_start = 1;
break;
}
state &= ~NO_SEND_IV;
state |= NO_RECV_IV;
if (encrypt_debug_mode)
printf("Creating new feed\r\n");
/*
* Create a random feed and send it over.
*/
des_new_random_key(&fbp->temp_feed);
des_ecb_encrypt(&fbp->temp_feed, &fbp->temp_feed,
fbp->krbdes_sched, 1);
p = fbp->fb_feed + 3;
*p++ = ENCRYPT_IS;
p++;
*p++ = FB64_IV;
for (x = 0; x < sizeof(Block); ++x) {
if ((*p++ = fbp->temp_feed[x]) == IAC)
*p++ = IAC;
}
*p++ = IAC;
*p++ = SE;
printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
telnet_net_write(fbp->fb_feed, p - fbp->fb_feed);
break;
default:
return(FAILED);
}
return(fbp->state[dir-1] = state);
}
/*
* Returns:
* -1: some error. Negotiation is done, encryption not ready.
* 0: Successful, initial negotiation all done.
* 1: successful, negotiation not done yet.
*/
int
cfb64_is(data, cnt)
unsigned char *data;
int cnt;
{
return(fb64_is(data, cnt, &fb[CFB]));
}
int
ofb64_is(data, cnt)
unsigned char *data;
int cnt;
{
return(fb64_is(data, cnt, &fb[OFB]));
}
int
fb64_is(data, cnt, fbp)
unsigned char *data;
int cnt;
struct fb *fbp;
{
unsigned char *p;
register int state = fbp->state[DIR_DECRYPT-1];
if (cnt-- < 1)
goto failure;
switch (*data++) {
case FB64_IV:
if (cnt != sizeof(Block)) {
if (encrypt_debug_mode)
printf("CFB64: initial vector failed on size\r\n");
state = FAILED;
goto failure;
}
if (encrypt_debug_mode)
printf("CFB64: initial vector received\r\n");
if (encrypt_debug_mode)
printf("Initializing Decrypt stream\r\n");
fb64_stream_iv((void *)data, &fbp->streams[DIR_DECRYPT-1]);
p = fbp->fb_feed + 3;
*p++ = ENCRYPT_REPLY;
p++;
*p++ = FB64_IV_OK;
*p++ = IAC;
*p++ = SE;
printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
telnet_net_write(fbp->fb_feed, p - fbp->fb_feed);
state = fbp->state[DIR_DECRYPT-1] = IN_PROGRESS;
break;
default:
if (encrypt_debug_mode) {
printf("Unknown option type: %d\r\n", *(data-1));
printd(data, cnt);
printf("\r\n");
}
/* FALL THROUGH */
failure:
/*
* We failed. Send an FB64_IV_BAD option
* to the other side so it will know that
* things failed.
*/
p = fbp->fb_feed + 3;
*p++ = ENCRYPT_REPLY;
p++;
*p++ = FB64_IV_BAD;
*p++ = IAC;
*p++ = SE;
printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
telnet_net_write(fbp->fb_feed, p - fbp->fb_feed);
break;
}
return(fbp->state[DIR_DECRYPT-1] = state);
}
/*
* Returns:
* -1: some error. Negotiation is done, encryption not ready.
* 0: Successful, initial negotiation all done.
* 1: successful, negotiation not done yet.
*/
int
cfb64_reply(data, cnt)
unsigned char *data;
int cnt;
{
return(fb64_reply(data, cnt, &fb[CFB]));
}
int
ofb64_reply(data, cnt)
unsigned char *data;
int cnt;
{
return(fb64_reply(data, cnt, &fb[OFB]));
}
int
fb64_reply(data, cnt, fbp)
unsigned char *data;
int cnt;
struct fb *fbp;
{
register int state = fbp->state[DIR_ENCRYPT-1];
if (cnt-- < 1)
goto failure;
switch (*data++) {
case FB64_IV_OK:
fb64_stream_iv(fbp->temp_feed, &fbp->streams[DIR_ENCRYPT-1]);
if (state == FAILED)
state = IN_PROGRESS;
state &= ~NO_RECV_IV;
encrypt_send_keyid(DIR_ENCRYPT, (unsigned char *)"\0", 1, 1);
break;
case FB64_IV_BAD:
memset(fbp->temp_feed, 0, sizeof(Block));
fb64_stream_iv(fbp->temp_feed, &fbp->streams[DIR_ENCRYPT-1]);
state = FAILED;
break;
default:
if (encrypt_debug_mode) {
printf("Unknown option type: %d\r\n", data[-1]);
printd(data, cnt);
printf("\r\n");
}
/* FALL THROUGH */
failure:
state = FAILED;
break;
}
return(fbp->state[DIR_ENCRYPT-1] = state);
}
void
cfb64_session(key, server)
Session_Key *key;
int server;
{
fb64_session(key, server, &fb[CFB]);
}
void
ofb64_session(key, server)
Session_Key *key;
int server;
{
fb64_session(key, server, &fb[OFB]);
}
static void
fb64_session(key, server, fbp)
Session_Key *key;
int server;
struct fb *fbp;
{
if (!key || key->type != SK_DES) {
if (encrypt_debug_mode)
printf("Can't set krbdes's session key (%d != %d)\r\n",
key ? key->type : -1, SK_DES);
return;
}
memmove((void *)fbp->krbdes_key, (void *)key->data, sizeof(Block));
fb64_stream_key(&fbp->krbdes_key, &fbp->streams[DIR_ENCRYPT-1]);
fb64_stream_key(&fbp->krbdes_key, &fbp->streams[DIR_DECRYPT-1]);
if (fbp->once == 0) {
des_init_random_number_generator(&fbp->krbdes_key);
fbp->once = 1;
}
des_key_sched(&fbp->krbdes_key, fbp->krbdes_sched);
/*
* Now look to see if krbdes_start() was was waiting for
* the key to show up. If so, go ahead an call it now
* that we have the key.
*/
if (fbp->need_start) {
fbp->need_start = 0;
fb64_start(fbp, DIR_ENCRYPT, server);
}
}
/*
* We only accept a keyid of 0. If we get a keyid of
* 0, then mark the state as SUCCESS.
*/
int
cfb64_keyid(dir, kp, lenp)
int dir, *lenp;
unsigned char *kp;
{
return(fb64_keyid(dir, kp, lenp, &fb[CFB]));
}
int
ofb64_keyid(dir, kp, lenp)
int dir, *lenp;
unsigned char *kp;
{
return(fb64_keyid(dir, kp, lenp, &fb[OFB]));
}
int
fb64_keyid(dir, kp, lenp, fbp)
int dir, *lenp;
unsigned char *kp;
struct fb *fbp;
{
register int state = fbp->state[dir-1];
if (*lenp != 1 || (*kp != '\0')) {
*lenp = 0;
return(state);
}
if (state == FAILED)
state = IN_PROGRESS;
state &= ~NO_KEYID;
return(fbp->state[dir-1] = state);
}
void
fb64_printsub(data, cnt, buf, buflen, type)
unsigned char *data, *buf, *type;
int cnt, buflen;
{
char lbuf[32];
register int i;
char *cp;
buf[buflen-1] = '\0'; /* make sure it's NULL terminated */
buflen -= 1;
switch(data[2]) {
case FB64_IV:
snprintf(lbuf, sizeof(lbuf), "%s_IV", type);
cp = lbuf;
goto common;
case FB64_IV_OK:
snprintf(lbuf, sizeof(lbuf), "%s_IV_OK", type);
cp = lbuf;
goto common;
case FB64_IV_BAD:
snprintf(lbuf, sizeof(lbuf), "%s_IV_BAD", type);
cp = lbuf;
goto common;
default:
snprintf(lbuf, sizeof(lbuf), " %d (unknown)", data[2]);
cp = lbuf;
common:
for (; (buflen > 0) && (*buf = *cp++); buf++)
buflen--;
for (i = 3; i < cnt; i++) {
snprintf(lbuf, sizeof(lbuf), " %d", data[i]);
for (cp = lbuf; (buflen > 0) && (*buf = *cp++); buf++)
buflen--;
}
break;
}
}
void
cfb64_printsub(data, cnt, buf, buflen)
unsigned char *data, *buf;
int cnt, buflen;
{
fb64_printsub(data, cnt, buf, buflen, "CFB64");
}
void
ofb64_printsub(data, cnt, buf, buflen)
unsigned char *data, *buf;
int cnt, buflen;
{
fb64_printsub(data, cnt, buf, buflen, "OFB64");
}
void
fb64_stream_iv(seed, stp)
Block seed;
register struct stinfo *stp;
{
memmove((void *)stp->str_iv, (void *)seed, sizeof(Block));
memmove((void *)stp->str_output, (void *)seed, sizeof(Block));
des_key_sched(&stp->str_ikey, stp->str_sched);
stp->str_index = sizeof(Block);
}
void
fb64_stream_key(key, stp)
Block *key;
register struct stinfo *stp;
{
memmove((void *)stp->str_ikey, (void *)key, sizeof(Block));
des_key_sched(key, stp->str_sched);
memmove((void *)stp->str_output, (void *)stp->str_iv, sizeof(Block));
stp->str_index = sizeof(Block);
}
/*
* DES 64 bit Cipher Feedback
*
* key --->+-----+
* +->| DES |--+
* | +-----+ |
* | v
* INPUT --(--------->(+)+---> DATA
* | |
* +-------------+
*
*
* Given:
* iV: Initial vector, 64 bits (8 bytes) long.
* Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
* On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
*
* V0 = DES(iV, key)
* On = Dn ^ Vn
* V(n+1) = DES(On, key)
*/
void
cfb64_encrypt(s, c)
register unsigned char *s;
int c;
{
register struct stinfo *stp = &fb[CFB].streams[DIR_ENCRYPT-1];
register int idx;
idx = stp->str_index;
while (c-- > 0) {
if (idx == sizeof(Block)) {
Block b;
des_ecb_encrypt(&stp->str_output, &b, stp->str_sched, 1);
memmove((void *)stp->str_feed, (void *)b, sizeof(Block));
idx = 0;
}
/* On encryption, we store (feed ^ data) which is cypher */
*s = stp->str_output[idx] = (stp->str_feed[idx] ^ *s);
s++;
idx++;
}
stp->str_index = idx;
}
int
cfb64_decrypt(data)
int data;
{
register struct stinfo *stp = &fb[CFB].streams[DIR_DECRYPT-1];
int idx;
if (data == -1) {
/*
* Back up one byte. It is assumed that we will
* never back up more than one byte. If we do, this
* may or may not work.
*/
if (stp->str_index)
--stp->str_index;
return(0);
}
idx = stp->str_index++;
if (idx == sizeof(Block)) {
Block b;
des_ecb_encrypt(&stp->str_output, &b, stp->str_sched, 1);
memmove((void *)stp->str_feed, (void *)b, sizeof(Block));
stp->str_index = 1; /* Next time will be 1 */
idx = 0; /* But now use 0 */
}
/* On decryption we store (data) which is cypher. */
stp->str_output[idx] = data;
return(data ^ stp->str_feed[idx]);
}
/*
* DES 64 bit Output Feedback
*
* key --->+-----+
* +->| DES |--+
* | +-----+ |
* +-----------+
* v
* INPUT -------->(+) ----> DATA
*
* Given:
* iV: Initial vector, 64 bits (8 bytes) long.
* Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
* On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
*
* V0 = DES(iV, key)
* V(n+1) = DES(Vn, key)
* On = Dn ^ Vn
*/
void
ofb64_encrypt(s, c)
register unsigned char *s;
int c;
{
register struct stinfo *stp = &fb[OFB].streams[DIR_ENCRYPT-1];
register int idx;
idx = stp->str_index;
while (c-- > 0) {
if (idx == sizeof(Block)) {
Block b;
des_ecb_encrypt(&stp->str_feed, &b, stp->str_sched, 1);
memmove((void *)stp->str_feed, (void *)b, sizeof(Block));
idx = 0;
}
*s++ ^= stp->str_feed[idx];
idx++;
}
stp->str_index = idx;
}
int
ofb64_decrypt(data)
int data;
{
register struct stinfo *stp = &fb[OFB].streams[DIR_DECRYPT-1];
int idx;
if (data == -1) {
/*
* Back up one byte. It is assumed that we will
* never back up more than one byte. If we do, this
* may or may not work.
*/
if (stp->str_index)
--stp->str_index;
return(0);
}
idx = stp->str_index++;
if (idx == sizeof(Block)) {
Block b;
des_ecb_encrypt(&stp->str_feed, &b, stp->str_sched, 1);
memmove((void *)stp->str_feed, (void *)b, sizeof(Block));
stp->str_index = 1; /* Next time will be 1 */
idx = 0; /* But now use 0 */
}
return(data ^ stp->str_feed[idx]);
}
# endif /* DES_ENCRYPTION */
# endif /* AUTHENTICATION */
#endif /* ENCRYPTION */