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.
212 if (DES_new_random_key(&fbp
->temp_feed
))
215 DES_ecb_encrypt(&fbp
->temp_feed
,
217 &fbp
->krbdes_sched
, 1);
218 p
= fbp
->fb_feed
+ 3;
222 for (x
= 0; x
< sizeof(DES_cblock
); ++x
) {
223 if ((*p
++ = fbp
->temp_feed
[x
]) == IAC
)
228 printsub('>', &fbp
->fb_feed
[2], p
- &fbp
->fb_feed
[2]);
229 telnet_net_write(fbp
->fb_feed
, p
- fbp
->fb_feed
);
234 return(fbp
->state
[dir
-1] = state
);
239 * -1: some error. Negotiation is done, encryption not ready.
240 * 0: Successful, initial negotiation all done.
241 * 1: successful, negotiation not done yet.
244 int cfb64_is(unsigned char *data
, int cnt
)
246 return(fb64_is(data
, cnt
, &fb
[CFB
]));
249 int ofb64_is(unsigned char *data
, int cnt
)
251 return(fb64_is(data
, cnt
, &fb
[OFB
]));
255 int fb64_is(unsigned char *data
, int cnt
, struct fb
*fbp
)
258 int state
= fbp
->state
[DIR_DECRYPT
-1];
265 if (cnt
!= sizeof(DES_cblock
)) {
266 if (encrypt_debug_mode
)
267 printf("CFB64: initial vector failed on size\r\n");
272 if (encrypt_debug_mode
)
273 printf("CFB64: initial vector received\r\n");
275 if (encrypt_debug_mode
)
276 printf("Initializing Decrypt stream\r\n");
278 fb64_stream_iv(data
, &fbp
->streams
[DIR_DECRYPT
-1]);
280 p
= fbp
->fb_feed
+ 3;
281 *p
++ = ENCRYPT_REPLY
;
286 printsub('>', &fbp
->fb_feed
[2], p
- &fbp
->fb_feed
[2]);
287 telnet_net_write(fbp
->fb_feed
, p
- fbp
->fb_feed
);
289 state
= fbp
->state
[DIR_DECRYPT
-1] = IN_PROGRESS
;
293 if (encrypt_debug_mode
) {
294 printf("Unknown option type: %d\r\n", *(data
-1));
301 * We failed. Send an FB64_IV_BAD option
302 * to the other side so it will know that
305 p
= fbp
->fb_feed
+ 3;
306 *p
++ = ENCRYPT_REPLY
;
311 printsub('>', &fbp
->fb_feed
[2], p
- &fbp
->fb_feed
[2]);
312 telnet_net_write(fbp
->fb_feed
, p
- fbp
->fb_feed
);
316 return(fbp
->state
[DIR_DECRYPT
-1] = state
);
321 * -1: some error. Negotiation is done, encryption not ready.
322 * 0: Successful, initial negotiation all done.
323 * 1: successful, negotiation not done yet.
326 int cfb64_reply(unsigned char *data
, int cnt
)
328 return(fb64_reply(data
, cnt
, &fb
[CFB
]));
331 int ofb64_reply(unsigned char *data
, int cnt
)
333 return(fb64_reply(data
, cnt
, &fb
[OFB
]));
337 int fb64_reply(unsigned char *data
, int cnt
, struct fb
*fbp
)
339 int state
= fbp
->state
[DIR_ENCRYPT
-1];
346 fb64_stream_iv(fbp
->temp_feed
, &fbp
->streams
[DIR_ENCRYPT
-1]);
349 state
&= ~NO_RECV_IV
;
350 encrypt_send_keyid(DIR_ENCRYPT
, (unsigned char *)"\0", 1, 1);
354 memset(fbp
->temp_feed
, 0, sizeof(DES_cblock
));
355 fb64_stream_iv(fbp
->temp_feed
, &fbp
->streams
[DIR_ENCRYPT
-1]);
360 if (encrypt_debug_mode
) {
361 printf("Unknown option type: %d\r\n", data
[-1]);
370 return(fbp
->state
[DIR_ENCRYPT
-1] = state
);
373 void cfb64_session(Session_Key
*key
, int server
)
375 fb64_session(key
, server
, &fb
[CFB
]);
378 void ofb64_session(Session_Key
*key
, int server
)
380 fb64_session(key
, server
, &fb
[OFB
]);
383 static void fb64_session(Session_Key
*key
, int server
, struct fb
*fbp
)
386 if (!key
|| key
->type
!= SK_DES
) {
387 if (encrypt_debug_mode
)
388 printf("Can't set krbdes's session key (%d != %d)\r\n",
389 key
? key
->type
: -1, SK_DES
);
392 memcpy(fbp
->krbdes_key
, key
->data
, sizeof(DES_cblock
));
394 fb64_stream_key(fbp
->krbdes_key
, &fbp
->streams
[DIR_ENCRYPT
-1]);
395 fb64_stream_key(fbp
->krbdes_key
, &fbp
->streams
[DIR_DECRYPT
-1]);
397 DES_set_key_checked((DES_cblock
*)&fbp
->krbdes_key
,
400 * Now look to see if krbdes_start() was was waiting for
401 * the key to show up. If so, go ahead an call it now
402 * that we have the key.
404 if (fbp
->need_start
) {
406 fb64_start(fbp
, DIR_ENCRYPT
, server
);
411 * We only accept a keyid of 0. If we get a keyid of
412 * 0, then mark the state as SUCCESS.
415 int cfb64_keyid(int dir
, unsigned char *kp
, int *lenp
)
417 return(fb64_keyid(dir
, kp
, lenp
, &fb
[CFB
]));
420 int ofb64_keyid(int dir
, unsigned char *kp
, int *lenp
)
422 return(fb64_keyid(dir
, kp
, lenp
, &fb
[OFB
]));
425 int fb64_keyid(int dir
, unsigned char *kp
, int *lenp
, struct fb
*fbp
)
427 int state
= fbp
->state
[dir
-1];
429 if (*lenp
!= 1 || (*kp
!= '\0')) {
439 return(fbp
->state
[dir
-1] = state
);
442 void fb64_printsub(unsigned char *data
, size_t cnt
,
443 unsigned char *buf
, size_t buflen
, char *type
)
449 buf
[buflen
-1] = '\0'; /* make sure it's NULL terminated */
454 snprintf(lbuf
, sizeof(lbuf
), "%s_IV", type
);
459 snprintf(lbuf
, sizeof(lbuf
), "%s_IV_OK", type
);
464 snprintf(lbuf
, sizeof(lbuf
), "%s_IV_BAD", type
);
469 snprintf(lbuf
, sizeof(lbuf
), " %d (unknown)", data
[2]);
472 for (; (buflen
> 0) && (*buf
= *cp
++); buf
++)
474 for (i
= 3; i
< cnt
; i
++) {
475 snprintf(lbuf
, sizeof(lbuf
), " %d", data
[i
]);
476 for (cp
= lbuf
; (buflen
> 0) && (*buf
= *cp
++); buf
++)
483 void cfb64_printsub(unsigned char *data
, size_t cnt
,
484 unsigned char *buf
, size_t buflen
)
486 fb64_printsub(data
, cnt
, buf
, buflen
, "CFB64");
489 void ofb64_printsub(unsigned char *data
, size_t cnt
,
490 unsigned char *buf
, size_t buflen
)
492 fb64_printsub(data
, cnt
, buf
, buflen
, "OFB64");
495 void fb64_stream_iv(DES_cblock seed
, struct stinfo
*stp
)
498 memcpy(stp
->str_iv
, seed
,sizeof(DES_cblock
));
499 memcpy(stp
->str_output
, seed
, sizeof(DES_cblock
));
501 DES_set_key_checked(&stp
->str_ikey
, &stp
->str_sched
);
503 stp
->str_index
= sizeof(DES_cblock
);
506 void fb64_stream_key(DES_cblock key
, struct stinfo
*stp
)
508 memcpy(stp
->str_ikey
, key
, sizeof(DES_cblock
));
509 DES_set_key_checked((DES_cblock
*)key
, &stp
->str_sched
);
511 memcpy(stp
->str_output
, stp
->str_iv
, sizeof(DES_cblock
));
513 stp
->str_index
= sizeof(DES_cblock
);
517 * DES 64 bit Cipher Feedback
523 * INPUT --(--------->(+)+---> DATA
529 * iV: Initial vector, 64 bits (8 bytes) long.
530 * Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
531 * On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
535 * V(n+1) = DES(On, key)
538 void cfb64_encrypt(unsigned char *s
, int c
)
540 struct stinfo
*stp
= &fb
[CFB
].streams
[DIR_ENCRYPT
-1];
543 index
= stp
->str_index
;
545 if (index
== sizeof(DES_cblock
)) {
547 DES_ecb_encrypt(&stp
->str_output
, &b
,&stp
->str_sched
, 1);
548 memcpy(stp
->str_feed
, b
, sizeof(DES_cblock
));
552 /* On encryption, we store (feed ^ data) which is cypher */
553 *s
= stp
->str_output
[index
] = (stp
->str_feed
[index
] ^ *s
);
557 stp
->str_index
= index
;
560 int cfb64_decrypt(int data
)
562 struct stinfo
*stp
= &fb
[CFB
].streams
[DIR_DECRYPT
-1];
567 * Back up one byte. It is assumed that we will
568 * never back up more than one byte. If we do, this
569 * may or may not work.
576 index
= stp
->str_index
++;
577 if (index
== sizeof(DES_cblock
)) {
579 DES_ecb_encrypt(&stp
->str_output
,&b
, &stp
->str_sched
, 1);
580 memcpy(stp
->str_feed
, b
, sizeof(DES_cblock
));
581 stp
->str_index
= 1; /* Next time will be 1 */
582 index
= 0; /* But now use 0 */
585 /* On decryption we store (data) which is cypher. */
586 stp
->str_output
[index
] = data
;
587 return(data
^ stp
->str_feed
[index
]);
591 * DES 64 bit Output Feedback
598 * INPUT -------->(+) ----> DATA
601 * iV: Initial vector, 64 bits (8 bytes) long.
602 * Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
603 * On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
606 * V(n+1) = DES(Vn, key)
610 void ofb64_encrypt(unsigned char *s
, int c
)
612 struct stinfo
*stp
= &fb
[OFB
].streams
[DIR_ENCRYPT
-1];
615 index
= stp
->str_index
;
617 if (index
== sizeof(DES_cblock
)) {
619 DES_ecb_encrypt(&stp
->str_feed
,&b
, &stp
->str_sched
, 1);
620 memcpy(stp
->str_feed
, b
, sizeof(DES_cblock
));
623 *s
++ ^= stp
->str_feed
[index
];
626 stp
->str_index
= index
;
629 int ofb64_decrypt(int data
)
631 struct stinfo
*stp
= &fb
[OFB
].streams
[DIR_DECRYPT
-1];
636 * Back up one byte. It is assumed that we will
637 * never back up more than one byte. If we do, this
638 * may or may not work.
645 index
= stp
->str_index
++;
646 if (index
== sizeof(DES_cblock
)) {
648 DES_ecb_encrypt(&stp
->str_feed
,&b
,&stp
->str_sched
, 1);
649 memcpy(stp
->str_feed
, b
, sizeof(DES_cblock
));
650 stp
->str_index
= 1; /* Next time will be 1 */
651 index
= 0; /* But now use 0 */
654 return(data
^ stp
->str_feed
[index
]);