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
38 #if defined(AUTHENTICATION) && defined(ENCRYPTION) && defined(DES_ENCRYPTION)
39 #include <arpa/telnet.h>
51 #include "misc-proto.h"
53 #include "crypto-headers.h"
55 extern int encrypt_debug_mode
;
63 #define IN_PROGRESS (NO_SEND_IV|NO_RECV_IV|NO_KEYID)
69 DES_cblock str_output
;
73 DES_key_schedule str_sched
;
79 DES_cblock krbdes_key
;
80 DES_key_schedule krbdes_sched
;
82 unsigned char fb_feed
[64];
86 struct stinfo streams
[2];
89 static struct fb fb
[2];
98 { "\0", 1, 0, 0, 0 }, /* default key of zero */
102 #define KEYFLAG_MASK 03
104 #define KEYFLAG_NOINIT 00
105 #define KEYFLAG_INIT 01
106 #define KEYFLAG_OK 02
107 #define KEYFLAG_BAD 03
109 #define KEYFLAG_SHIFT 2
111 #define SHIFT_VAL(a,b) (KEYFLAG_SHIFT*((a)+((b)*2)))
115 #define FB64_IV_BAD 3
118 void fb64_stream_iv (DES_cblock
, struct stinfo
*);
119 void fb64_init (struct fb
*);
120 static int fb64_start (struct fb
*, int, int);
121 int fb64_is (unsigned char *, int, struct fb
*);
122 int fb64_reply (unsigned char *, int, struct fb
*);
123 static void fb64_session (Session_Key
*, int, struct fb
*);
124 void fb64_stream_key (DES_cblock
, struct stinfo
*);
125 int fb64_keyid (int, unsigned char *, int *, struct fb
*);
126 void fb64_printsub(unsigned char *, size_t ,
127 unsigned char *, size_t , char *);
129 void cfb64_init(int server
)
132 fb
[CFB
].fb_feed
[4] = ENCTYPE_DES_CFB64
;
133 fb
[CFB
].streams
[0].str_flagshift
= SHIFT_VAL(0, CFB
);
134 fb
[CFB
].streams
[1].str_flagshift
= SHIFT_VAL(1, CFB
);
138 void ofb64_init(int server
)
141 fb
[OFB
].fb_feed
[4] = ENCTYPE_DES_OFB64
;
142 fb
[CFB
].streams
[0].str_flagshift
= SHIFT_VAL(0, OFB
);
143 fb
[CFB
].streams
[1].str_flagshift
= SHIFT_VAL(1, OFB
);
146 void fb64_init(struct fb
*fbp
)
148 memset(fbp
,0, sizeof(*fbp
));
149 fbp
->state
[0] = fbp
->state
[1] = FAILED
;
150 fbp
->fb_feed
[0] = IAC
;
151 fbp
->fb_feed
[1] = SB
;
152 fbp
->fb_feed
[2] = TELOPT_ENCRYPT
;
153 fbp
->fb_feed
[3] = ENCRYPT_IS
;
158 * -1: some error. Negotiation is done, encryption not ready.
159 * 0: Successful, initial negotiation all done.
160 * 1: successful, negotiation not done yet.
161 * 2: Not yet. Other things (like getting the key from
162 * Kerberos) have to happen before we can continue.
164 int cfb64_start(int dir
, int server
)
166 return(fb64_start(&fb
[CFB
], dir
, server
));
169 int ofb64_start(int dir
, int server
)
171 return(fb64_start(&fb
[OFB
], dir
, server
));
174 static int fb64_start(struct fb
*fbp
, int dir
, int server
)
183 * This is simply a request to have the other side
184 * start output (our input). He will negotiate an
185 * IV so we need not look for it.
187 state
= fbp
->state
[dir
-1];
193 state
= fbp
->state
[dir
-1];
196 else if ((state
& NO_SEND_IV
) == 0) {
200 if (!VALIDKEY(fbp
->krbdes_key
)) {
205 state
&= ~NO_SEND_IV
;
207 if (encrypt_debug_mode
)
208 printf("Creating new feed\r\n");
210 * Create a random feed and send it over.
213 if (RAND_bytes(fbp
->temp_feed
,
214 sizeof(*fbp
->temp_feed
)) != 1)
216 DES_set_odd_parity(&fbp
->temp_feed
);
217 } while(DES_is_weak_key(&fbp
->temp_feed
));
219 p
= fbp
->fb_feed
+ 3;
223 for (x
= 0; x
< sizeof(DES_cblock
); ++x
) {
224 if ((*p
++ = fbp
->temp_feed
[x
]) == IAC
)
229 printsub('>', &fbp
->fb_feed
[2], p
- &fbp
->fb_feed
[2]);
230 telnet_net_write(fbp
->fb_feed
, p
- fbp
->fb_feed
);
235 return(fbp
->state
[dir
-1] = state
);
240 * -1: some error. Negotiation is done, encryption not ready.
241 * 0: Successful, initial negotiation all done.
242 * 1: successful, negotiation not done yet.
245 int cfb64_is(unsigned char *data
, int cnt
)
247 return(fb64_is(data
, cnt
, &fb
[CFB
]));
250 int ofb64_is(unsigned char *data
, int cnt
)
252 return(fb64_is(data
, cnt
, &fb
[OFB
]));
256 int fb64_is(unsigned char *data
, int cnt
, struct fb
*fbp
)
259 int state
= fbp
->state
[DIR_DECRYPT
-1];
266 if (cnt
!= sizeof(DES_cblock
)) {
267 if (encrypt_debug_mode
)
268 printf("CFB64: initial vector failed on size\r\n");
273 if (encrypt_debug_mode
)
274 printf("CFB64: initial vector received\r\n");
276 if (encrypt_debug_mode
)
277 printf("Initializing Decrypt stream\r\n");
279 fb64_stream_iv(data
, &fbp
->streams
[DIR_DECRYPT
-1]);
281 p
= fbp
->fb_feed
+ 3;
282 *p
++ = ENCRYPT_REPLY
;
287 printsub('>', &fbp
->fb_feed
[2], p
- &fbp
->fb_feed
[2]);
288 telnet_net_write(fbp
->fb_feed
, p
- fbp
->fb_feed
);
290 state
= fbp
->state
[DIR_DECRYPT
-1] = IN_PROGRESS
;
294 if (encrypt_debug_mode
) {
295 printf("Unknown option type: %d\r\n", *(data
-1));
302 * We failed. Send an FB64_IV_BAD option
303 * to the other side so it will know that
306 p
= fbp
->fb_feed
+ 3;
307 *p
++ = ENCRYPT_REPLY
;
312 printsub('>', &fbp
->fb_feed
[2], p
- &fbp
->fb_feed
[2]);
313 telnet_net_write(fbp
->fb_feed
, p
- fbp
->fb_feed
);
317 return(fbp
->state
[DIR_DECRYPT
-1] = state
);
322 * -1: some error. Negotiation is done, encryption not ready.
323 * 0: Successful, initial negotiation all done.
324 * 1: successful, negotiation not done yet.
327 int cfb64_reply(unsigned char *data
, int cnt
)
329 return(fb64_reply(data
, cnt
, &fb
[CFB
]));
332 int ofb64_reply(unsigned char *data
, int cnt
)
334 return(fb64_reply(data
, cnt
, &fb
[OFB
]));
338 int fb64_reply(unsigned char *data
, int cnt
, struct fb
*fbp
)
340 int state
= fbp
->state
[DIR_ENCRYPT
-1];
347 fb64_stream_iv(fbp
->temp_feed
, &fbp
->streams
[DIR_ENCRYPT
-1]);
350 state
&= ~NO_RECV_IV
;
351 encrypt_send_keyid(DIR_ENCRYPT
, (unsigned char *)"\0", 1, 1);
355 memset(fbp
->temp_feed
, 0, sizeof(DES_cblock
));
356 fb64_stream_iv(fbp
->temp_feed
, &fbp
->streams
[DIR_ENCRYPT
-1]);
361 if (encrypt_debug_mode
) {
362 printf("Unknown option type: %d\r\n", data
[-1]);
371 return(fbp
->state
[DIR_ENCRYPT
-1] = state
);
374 void cfb64_session(Session_Key
*key
, int server
)
376 fb64_session(key
, server
, &fb
[CFB
]);
379 void ofb64_session(Session_Key
*key
, int server
)
381 fb64_session(key
, server
, &fb
[OFB
]);
384 static void fb64_session(Session_Key
*key
, int server
, struct fb
*fbp
)
387 if (!key
|| key
->type
!= SK_DES
) {
388 if (encrypt_debug_mode
)
389 printf("Can't set krbdes's session key (%d != %d)\r\n",
390 key
? key
->type
: -1, SK_DES
);
393 memcpy(fbp
->krbdes_key
, key
->data
, sizeof(DES_cblock
));
395 fb64_stream_key(fbp
->krbdes_key
, &fbp
->streams
[DIR_ENCRYPT
-1]);
396 fb64_stream_key(fbp
->krbdes_key
, &fbp
->streams
[DIR_DECRYPT
-1]);
398 RAND_seed(key
->data
, key
->length
);
400 DES_set_key_checked((DES_cblock
*)&fbp
->krbdes_key
,
403 * Now look to see if krbdes_start() was waiting for the key to
404 * show up. If so, go ahead an call it now that we have the key.
406 if (fbp
->need_start
) {
408 fb64_start(fbp
, DIR_ENCRYPT
, server
);
413 * We only accept a keyid of 0. If we get a keyid of
414 * 0, then mark the state as SUCCESS.
417 int cfb64_keyid(int dir
, unsigned char *kp
, int *lenp
)
419 return(fb64_keyid(dir
, kp
, lenp
, &fb
[CFB
]));
422 int ofb64_keyid(int dir
, unsigned char *kp
, int *lenp
)
424 return(fb64_keyid(dir
, kp
, lenp
, &fb
[OFB
]));
427 int fb64_keyid(int dir
, unsigned char *kp
, int *lenp
, struct fb
*fbp
)
429 int state
= fbp
->state
[dir
-1];
431 if (*lenp
!= 1 || (*kp
!= '\0')) {
441 return(fbp
->state
[dir
-1] = state
);
444 void fb64_printsub(unsigned char *data
, size_t cnt
,
445 unsigned char *buf
, size_t buflen
, char *type
)
451 buf
[buflen
-1] = '\0'; /* make sure it's NULL terminated */
456 snprintf(lbuf
, sizeof(lbuf
), "%s_IV", type
);
461 snprintf(lbuf
, sizeof(lbuf
), "%s_IV_OK", type
);
466 snprintf(lbuf
, sizeof(lbuf
), "%s_IV_BAD", type
);
471 snprintf(lbuf
, sizeof(lbuf
), " %d (unknown)", data
[2]);
474 for (; (buflen
> 0) && (*buf
= *cp
++); buf
++)
476 for (i
= 3; i
< cnt
; i
++) {
477 snprintf(lbuf
, sizeof(lbuf
), " %d", data
[i
]);
478 for (cp
= lbuf
; (buflen
> 0) && (*buf
= *cp
++); buf
++)
485 void cfb64_printsub(unsigned char *data
, size_t cnt
,
486 unsigned char *buf
, size_t buflen
)
488 fb64_printsub(data
, cnt
, buf
, buflen
, "CFB64");
491 void ofb64_printsub(unsigned char *data
, size_t cnt
,
492 unsigned char *buf
, size_t buflen
)
494 fb64_printsub(data
, cnt
, buf
, buflen
, "OFB64");
497 void fb64_stream_iv(DES_cblock seed
, struct stinfo
*stp
)
500 memcpy(stp
->str_iv
, seed
,sizeof(DES_cblock
));
501 memcpy(stp
->str_output
, seed
, sizeof(DES_cblock
));
503 DES_set_key_checked(&stp
->str_ikey
, &stp
->str_sched
);
505 stp
->str_index
= sizeof(DES_cblock
);
508 void fb64_stream_key(DES_cblock key
, struct stinfo
*stp
)
510 memcpy(stp
->str_ikey
, key
, sizeof(DES_cblock
));
511 DES_set_key_checked((DES_cblock
*)key
, &stp
->str_sched
);
513 memcpy(stp
->str_output
, stp
->str_iv
, sizeof(DES_cblock
));
515 stp
->str_index
= sizeof(DES_cblock
);
519 * DES 64 bit Cipher Feedback
525 * INPUT --(--------->(+)+---> DATA
531 * iV: Initial vector, 64 bits (8 bytes) long.
532 * Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
533 * On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
537 * V(n+1) = DES(On, key)
540 void cfb64_encrypt(unsigned char *s
, int c
)
542 struct stinfo
*stp
= &fb
[CFB
].streams
[DIR_ENCRYPT
-1];
545 index
= stp
->str_index
;
547 if (index
== sizeof(DES_cblock
)) {
549 DES_ecb_encrypt(&stp
->str_output
, &b
,&stp
->str_sched
, 1);
550 memcpy(stp
->str_feed
, b
, sizeof(DES_cblock
));
554 /* On encryption, we store (feed ^ data) which is cypher */
555 *s
= stp
->str_output
[index
] = (stp
->str_feed
[index
] ^ *s
);
559 stp
->str_index
= index
;
562 int cfb64_decrypt(int data
)
564 struct stinfo
*stp
= &fb
[CFB
].streams
[DIR_DECRYPT
-1];
569 * Back up one byte. It is assumed that we will
570 * never back up more than one byte. If we do, this
571 * may or may not work.
578 index
= stp
->str_index
++;
579 if (index
== sizeof(DES_cblock
)) {
581 DES_ecb_encrypt(&stp
->str_output
,&b
, &stp
->str_sched
, 1);
582 memcpy(stp
->str_feed
, b
, sizeof(DES_cblock
));
583 stp
->str_index
= 1; /* Next time will be 1 */
584 index
= 0; /* But now use 0 */
587 /* On decryption we store (data) which is cypher. */
588 stp
->str_output
[index
] = data
;
589 return(data
^ stp
->str_feed
[index
]);
593 * DES 64 bit Output Feedback
600 * INPUT -------->(+) ----> DATA
603 * iV: Initial vector, 64 bits (8 bytes) long.
604 * Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
605 * On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
608 * V(n+1) = DES(Vn, key)
612 void ofb64_encrypt(unsigned char *s
, int c
)
614 struct stinfo
*stp
= &fb
[OFB
].streams
[DIR_ENCRYPT
-1];
617 index
= stp
->str_index
;
619 if (index
== sizeof(DES_cblock
)) {
621 DES_ecb_encrypt(&stp
->str_feed
,&b
, &stp
->str_sched
, 1);
622 memcpy(stp
->str_feed
, b
, sizeof(DES_cblock
));
625 *s
++ ^= stp
->str_feed
[index
];
628 stp
->str_index
= index
;
631 int ofb64_decrypt(int data
)
633 struct stinfo
*stp
= &fb
[OFB
].streams
[DIR_DECRYPT
-1];
638 * Back up one byte. It is assumed that we will
639 * never back up more than one byte. If we do, this
640 * may or may not work.
647 index
= stp
->str_index
++;
648 if (index
== sizeof(DES_cblock
)) {
650 DES_ecb_encrypt(&stp
->str_feed
,&b
,&stp
->str_sched
, 1);
651 memcpy(stp
->str_feed
, b
, sizeof(DES_cblock
));
652 stp
->str_index
= 1; /* Next time will be 1 */
653 index
= 0; /* But now use 0 */
656 return(data
^ stp
->str_feed
[index
]);