2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 RCSID("$Id: enc_des.c,v 1.18 2001/02/24 05:47:39 assar Exp $");
38 #if defined(AUTHENTICATION) && defined(ENCRYPTION) && defined(DES_ENCRYPTION)
39 #include <arpa/telnet.h>
51 #include "misc-proto.h"
53 #ifdef HAVE_OPENSSL_DES_H
54 #include <openssl/des.h>
59 extern int encrypt_debug_mode;
67 #define IN_PROGRESS (NO_SEND_IV|NO_RECV_IV|NO_KEYID)
73 des_cblock str_output;
77 des_key_schedule str_sched;
83 des_cblock krbdes_key;
84 des_key_schedule krbdes_sched;
86 unsigned char fb_feed[64];
91 struct stinfo streams[2];
94 static struct fb fb[2];
103 { "\0", 1, 0, 0, 0 }, /* default key of zero */
107 #define KEYFLAG_MASK 03
109 #define KEYFLAG_NOINIT 00
110 #define KEYFLAG_INIT 01
111 #define KEYFLAG_OK 02
112 #define KEYFLAG_BAD 03
114 #define KEYFLAG_SHIFT 2
116 #define SHIFT_VAL(a,b) (KEYFLAG_SHIFT*((a)+((b)*2)))
120 #define FB64_IV_BAD 3
123 void fb64_stream_iv (des_cblock, struct stinfo *);
124 void fb64_init (struct fb *);
125 static int fb64_start (struct fb *, int, int);
126 int fb64_is (unsigned char *, int, struct fb *);
127 int fb64_reply (unsigned char *, int, struct fb *);
128 static void fb64_session (Session_Key *, int, struct fb *);
129 void fb64_stream_key (des_cblock, struct stinfo *);
130 int fb64_keyid (int, unsigned char *, int *, struct fb *);
132 void cfb64_init(int server)
135 fb[CFB].fb_feed[4] = ENCTYPE_DES_CFB64;
136 fb[CFB].streams[0].str_flagshift = SHIFT_VAL(0, CFB);
137 fb[CFB].streams[1].str_flagshift = SHIFT_VAL(1, CFB);
141 void ofb64_init(int server)
144 fb[OFB].fb_feed[4] = ENCTYPE_DES_OFB64;
145 fb[CFB].streams[0].str_flagshift = SHIFT_VAL(0, OFB);
146 fb[CFB].streams[1].str_flagshift = SHIFT_VAL(1, OFB);
149 void fb64_init(struct fb *fbp)
151 memset(fbp,0, sizeof(*fbp));
152 fbp->state[0] = fbp->state[1] = FAILED;
153 fbp->fb_feed[0] = IAC;
154 fbp->fb_feed[1] = SB;
155 fbp->fb_feed[2] = TELOPT_ENCRYPT;
156 fbp->fb_feed[3] = ENCRYPT_IS;
161 * -1: some error. Negotiation is done, encryption not ready.
162 * 0: Successful, initial negotiation all done.
163 * 1: successful, negotiation not done yet.
164 * 2: Not yet. Other things (like getting the key from
165 * Kerberos) have to happen before we can continue.
167 int cfb64_start(int dir, int server)
169 return(fb64_start(&fb[CFB], dir, server));
172 int ofb64_start(int dir, int server)
174 return(fb64_start(&fb[OFB], dir, server));
177 static int fb64_start(struct fb *fbp, int dir, int server)
186 * This is simply a request to have the other side
187 * start output (our input). He will negotiate an
188 * IV so we need not look for it.
190 state = fbp->state[dir-1];
196 state = fbp->state[dir-1];
199 else if ((state & NO_SEND_IV) == 0) {
203 if (!VALIDKEY(fbp->krbdes_key)) {
208 state &= ~NO_SEND_IV;
210 if (encrypt_debug_mode)
211 printf("Creating new feed\r\n");
213 * Create a random feed and send it over.
215 #ifndef OLD_DES_RANDOM_KEY
216 des_new_random_key(&fbp->temp_feed);
219 * From des_cryp.man "If the des_check_key flag is non-zero,
220 * des_set_key will check that the key passed is
221 * of odd parity and is not a week or semi-weak key."
224 des_random_key(fbp->temp_feed);
225 des_set_odd_parity(fbp->temp_feed);
226 } while (des_is_weak_key(fbp->temp_feed));
228 des_ecb_encrypt(&fbp->temp_feed,
230 fbp->krbdes_sched, 1);
231 p = fbp->fb_feed + 3;
235 for (x = 0; x < sizeof(des_cblock); ++x) {
236 if ((*p++ = fbp->temp_feed[x]) == IAC)
241 printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
242 telnet_net_write(fbp->fb_feed, p - fbp->fb_feed);
247 return(fbp->state[dir-1] = state);
252 * -1: some error. Negotiation is done, encryption not ready.
253 * 0: Successful, initial negotiation all done.
254 * 1: successful, negotiation not done yet.
257 int cfb64_is(unsigned char *data, int cnt)
259 return(fb64_is(data, cnt, &fb[CFB]));
262 int ofb64_is(unsigned char *data, int cnt)
264 return(fb64_is(data, cnt, &fb[OFB]));
268 int fb64_is(unsigned char *data, int cnt, struct fb *fbp)
271 int state = fbp->state[DIR_DECRYPT-1];
278 if (cnt != sizeof(des_cblock)) {
279 if (encrypt_debug_mode)
280 printf("CFB64: initial vector failed on size\r\n");
285 if (encrypt_debug_mode)
286 printf("CFB64: initial vector received\r\n");
288 if (encrypt_debug_mode)
289 printf("Initializing Decrypt stream\r\n");
291 fb64_stream_iv(data, &fbp->streams[DIR_DECRYPT-1]);
293 p = fbp->fb_feed + 3;
294 *p++ = ENCRYPT_REPLY;
299 printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
300 telnet_net_write(fbp->fb_feed, p - fbp->fb_feed);
302 state = fbp->state[DIR_DECRYPT-1] = IN_PROGRESS;
306 if (encrypt_debug_mode) {
307 printf("Unknown option type: %d\r\n", *(data-1));
314 * We failed. Send an FB64_IV_BAD option
315 * to the other side so it will know that
318 p = fbp->fb_feed + 3;
319 *p++ = ENCRYPT_REPLY;
324 printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
325 telnet_net_write(fbp->fb_feed, p - fbp->fb_feed);
329 return(fbp->state[DIR_DECRYPT-1] = state);
334 * -1: some error. Negotiation is done, encryption not ready.
335 * 0: Successful, initial negotiation all done.
336 * 1: successful, negotiation not done yet.
339 int cfb64_reply(unsigned char *data, int cnt)
341 return(fb64_reply(data, cnt, &fb[CFB]));
344 int ofb64_reply(unsigned char *data, int cnt)
346 return(fb64_reply(data, cnt, &fb[OFB]));
350 int fb64_reply(unsigned char *data, int cnt, struct fb *fbp)
352 int state = fbp->state[DIR_ENCRYPT-1];
359 fb64_stream_iv(fbp->temp_feed, &fbp->streams[DIR_ENCRYPT-1]);
362 state &= ~NO_RECV_IV;
363 encrypt_send_keyid(DIR_ENCRYPT, (unsigned char *)"\0", 1, 1);
367 memset(fbp->temp_feed, 0, sizeof(des_cblock));
368 fb64_stream_iv(fbp->temp_feed, &fbp->streams[DIR_ENCRYPT-1]);
373 if (encrypt_debug_mode) {
374 printf("Unknown option type: %d\r\n", data[-1]);
383 return(fbp->state[DIR_ENCRYPT-1] = state);
386 void cfb64_session(Session_Key *key, int server)
388 fb64_session(key, server, &fb[CFB]);
391 void ofb64_session(Session_Key *key, int server)
393 fb64_session(key, server, &fb[OFB]);
396 static void fb64_session(Session_Key *key, int server, struct fb *fbp)
399 if (!key || key->type != SK_DES) {
400 if (encrypt_debug_mode)
401 printf("Can't set krbdes's session key (%d != %d)\r\n",
402 key ? key->type : -1, SK_DES);
405 memcpy(fbp->krbdes_key, key->data, sizeof(des_cblock));
407 fb64_stream_key(fbp->krbdes_key, &fbp->streams[DIR_ENCRYPT-1]);
408 fb64_stream_key(fbp->krbdes_key, &fbp->streams[DIR_DECRYPT-1]);
410 if (fbp->once == 0) {
411 #if !defined(OLD_DES_RANDOM_KEY) && !defined(HAVE_OPENSSL_DES_H)
412 des_init_random_number_generator(&fbp->krbdes_key);
416 des_key_sched(&fbp->krbdes_key, fbp->krbdes_sched);
418 * Now look to see if krbdes_start() was was waiting for
419 * the key to show up. If so, go ahead an call it now
420 * that we have the key.
422 if (fbp->need_start) {
424 fb64_start(fbp, DIR_ENCRYPT, server);
429 * We only accept a keyid of 0. If we get a keyid of
430 * 0, then mark the state as SUCCESS.
433 int cfb64_keyid(int dir, unsigned char *kp, int *lenp)
435 return(fb64_keyid(dir, kp, lenp, &fb[CFB]));
438 int ofb64_keyid(int dir, unsigned char *kp, int *lenp)
440 return(fb64_keyid(dir, kp, lenp, &fb[OFB]));
443 int fb64_keyid(int dir, unsigned char *kp, int *lenp, struct fb *fbp)
445 int state = fbp->state[dir-1];
447 if (*lenp != 1 || (*kp != '\0')) {
457 return(fbp->state[dir-1] = state);
460 void fb64_printsub(unsigned char *data, int cnt,
461 unsigned char *buf, int buflen, char *type)
467 buf[buflen-1] = '\0'; /* make sure it's NULL terminated */
472 snprintf(lbuf, sizeof(lbuf), "%s_IV", type);
477 snprintf(lbuf, sizeof(lbuf), "%s_IV_OK", type);
482 snprintf(lbuf, sizeof(lbuf), "%s_IV_BAD", type);
487 snprintf(lbuf, sizeof(lbuf), " %d (unknown)", data[2]);
490 for (; (buflen > 0) && (*buf = *cp++); buf++)
492 for (i = 3; i < cnt; i++) {
493 snprintf(lbuf, sizeof(lbuf), " %d", data[i]);
494 for (cp = lbuf; (buflen > 0) && (*buf = *cp++); buf++)
501 void cfb64_printsub(unsigned char *data, int cnt,
502 unsigned char *buf, int buflen)
504 fb64_printsub(data, cnt, buf, buflen, "CFB64");
507 void ofb64_printsub(unsigned char *data, int cnt,
508 unsigned char *buf, int buflen)
510 fb64_printsub(data, cnt, buf, buflen, "OFB64");
513 void fb64_stream_iv(des_cblock seed, struct stinfo *stp)
516 memcpy(stp->str_iv, seed,sizeof(des_cblock));
517 memcpy(stp->str_output, seed, sizeof(des_cblock));
519 des_key_sched(&stp->str_ikey, stp->str_sched);
521 stp->str_index = sizeof(des_cblock);
524 void fb64_stream_key(des_cblock key, struct stinfo *stp)
526 memcpy(stp->str_ikey, key, sizeof(des_cblock));
527 des_key_sched((des_cblock*)key, stp->str_sched);
529 memcpy(stp->str_output, stp->str_iv, sizeof(des_cblock));
531 stp->str_index = sizeof(des_cblock);
535 * DES 64 bit Cipher Feedback
541 * INPUT --(--------->(+)+---> DATA
547 * iV: Initial vector, 64 bits (8 bytes) long.
548 * Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
549 * On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
553 * V(n+1) = DES(On, key)
556 void cfb64_encrypt(unsigned char *s, int c)
558 struct stinfo *stp = &fb[CFB].streams[DIR_ENCRYPT-1];
561 index = stp->str_index;
563 if (index == sizeof(des_cblock)) {
565 des_ecb_encrypt(&stp->str_output, &b,stp->str_sched, 1);
566 memcpy(stp->str_feed, b, sizeof(des_cblock));
570 /* On encryption, we store (feed ^ data) which is cypher */
571 *s = stp->str_output[index] = (stp->str_feed[index] ^ *s);
575 stp->str_index = index;
578 int cfb64_decrypt(int data)
580 struct stinfo *stp = &fb[CFB].streams[DIR_DECRYPT-1];
585 * Back up one byte. It is assumed that we will
586 * never back up more than one byte. If we do, this
587 * may or may not work.
594 index = stp->str_index++;
595 if (index == sizeof(des_cblock)) {
597 des_ecb_encrypt(&stp->str_output,&b, stp->str_sched, 1);
598 memcpy(stp->str_feed, b, sizeof(des_cblock));
599 stp->str_index = 1; /* Next time will be 1 */
600 index = 0; /* But now use 0 */
603 /* On decryption we store (data) which is cypher. */
604 stp->str_output[index] = data;
605 return(data ^ stp->str_feed[index]);
609 * DES 64 bit Output Feedback
616 * INPUT -------->(+) ----> DATA
619 * iV: Initial vector, 64 bits (8 bytes) long.
620 * Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
621 * On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
624 * V(n+1) = DES(Vn, key)
628 void ofb64_encrypt(unsigned char *s, int c)
630 struct stinfo *stp = &fb[OFB].streams[DIR_ENCRYPT-1];
633 index = stp->str_index;
635 if (index == sizeof(des_cblock)) {
637 des_ecb_encrypt(&stp->str_feed,&b, stp->str_sched, 1);
638 memcpy(stp->str_feed, b, sizeof(des_cblock));
641 *s++ ^= stp->str_feed[index];
644 stp->str_index = index;
647 int ofb64_decrypt(int data)
649 struct stinfo *stp = &fb[OFB].streams[DIR_DECRYPT-1];
654 * Back up one byte. It is assumed that we will
655 * never back up more than one byte. If we do, this
656 * may or may not work.
663 index = stp->str_index++;
664 if (index == sizeof(des_cblock)) {
666 des_ecb_encrypt(&stp->str_feed,&b,stp->str_sched, 1);
667 memcpy(stp->str_feed, b, sizeof(des_cblock));
668 stp->str_index = 1; /* Next time will be 1 */
669 index = 0; /* But now use 0 */
672 return(data ^ stp->str_feed[index]);