56
57#define CFB 0
58#define OFB 1
59
60#define NO_SEND_IV 1
61#define NO_RECV_IV 2
62#define NO_KEYID 4
63#define IN_PROGRESS (NO_SEND_IV|NO_RECV_IV|NO_KEYID)
64#define SUCCESS 0
65#define FAILED -1
66
67
68struct fb {
69 Block krbdes_key;
70 Schedule krbdes_sched;
71 Block temp_feed;
72 unsigned char fb_feed[64];
73 int need_start;
74 int state[2];
75 int keyid[2];
76 int once;
77 struct stinfo {
78 Block str_output;
79 Block str_feed;
80 Block str_iv;
81 Block str_ikey;
82 Schedule str_sched;
83 int str_index;
84 int str_flagshift;
85 } streams[2];
86};
87
88static struct fb fb[2];
89
90struct keyidlist {
91 char *keyid;
92 int keyidlen;
93 char *key;
94 int keylen;
95 int flags;
96} keyidlist [] = {
97 { "\0", 1, 0, 0, 0 }, /* default key of zero */
98 { 0, 0, 0, 0, 0 }
99};
100
101#define KEYFLAG_MASK 03
102
103#define KEYFLAG_NOINIT 00
104#define KEYFLAG_INIT 01
105#define KEYFLAG_OK 02
106#define KEYFLAG_BAD 03
107
108#define KEYFLAG_SHIFT 2
109
110#define SHIFT_VAL(a,b) (KEYFLAG_SHIFT*((a)+((b)*2)))
111
112#define FB64_IV 1
113#define FB64_IV_OK 2
114#define FB64_IV_BAD 3
115
116
117void fb64_stream_iv P((Block, struct stinfo *));
118void fb64_init P((struct fb *));
119static int fb64_start P((struct fb *, int, int));
120int fb64_is P((unsigned char *, int, struct fb *));
121int fb64_reply P((unsigned char *, int, struct fb *));
122static void fb64_session P((Session_Key *, int, struct fb *));
123void fb64_stream_key P((Block, struct stinfo *));
124int fb64_keyid P((int, unsigned char *, int *, struct fb *));
125
126 void
127cfb64_init(server)
128 int server;
129{
130 fb64_init(&fb[CFB]);
131 fb[CFB].fb_feed[4] = ENCTYPE_DES_CFB64;
132 fb[CFB].streams[0].str_flagshift = SHIFT_VAL(0, CFB);
133 fb[CFB].streams[1].str_flagshift = SHIFT_VAL(1, CFB);
134}
135
136 void
137ofb64_init(server)
138 int server;
139{
140 fb64_init(&fb[OFB]);
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);
144}
145
146 void
147fb64_init(fbp)
148 register struct fb *fbp;
149{
150 memset((void *)fbp, 0, sizeof(*fbp));
151 fbp->state[0] = fbp->state[1] = FAILED;
152 fbp->fb_feed[0] = IAC;
153 fbp->fb_feed[1] = SB;
154 fbp->fb_feed[2] = TELOPT_ENCRYPT;
155 fbp->fb_feed[3] = ENCRYPT_IS;
156}
157
158/*
159 * Returns:
160 * -1: some error. Negotiation is done, encryption not ready.
161 * 0: Successful, initial negotiation all done.
162 * 1: successful, negotiation not done yet.
163 * 2: Not yet. Other things (like getting the key from
164 * Kerberos) have to happen before we can continue.
165 */
166 int
167cfb64_start(dir, server)
168 int dir;
169 int server;
170{
171 return(fb64_start(&fb[CFB], dir, server));
172}
173 int
174ofb64_start(dir, server)
175 int dir;
176 int server;
177{
178 return(fb64_start(&fb[OFB], dir, server));
179}
180
181 static int
182fb64_start(fbp, dir, server)
183 struct fb *fbp;
184 int dir;
185 int server;
186{
187 int x;
188 unsigned char *p;
189 register int state;
190
191 switch (dir) {
192 case DIR_DECRYPT:
193 /*
194 * This is simply a request to have the other side
195 * start output (our input). He will negotiate an
196 * IV so we need not look for it.
197 */
198 state = fbp->state[dir-1];
199 if (state == FAILED)
200 state = IN_PROGRESS;
201 break;
202
203 case DIR_ENCRYPT:
204 state = fbp->state[dir-1];
205 if (state == FAILED)
206 state = IN_PROGRESS;
207 else if ((state & NO_SEND_IV) == 0)
208 break;
209
210 if (!VALIDKEY(fbp->krbdes_key)) {
211 fbp->need_start = 1;
212 break;
213 }
214 state &= ~NO_SEND_IV;
215 state |= NO_RECV_IV;
216 if (encrypt_debug_mode)
217 printf("Creating new feed\r\n");
218 /*
219 * Create a random feed and send it over.
220 */
221 des_new_random_key((Block *)fbp->temp_feed);
222 des_ecb_encrypt((Block *)fbp->temp_feed, (Block *)fbp->temp_feed,
223 fbp->krbdes_sched, 1);
224 p = fbp->fb_feed + 3;
225 *p++ = ENCRYPT_IS;
226 p++;
227 *p++ = FB64_IV;
228 for (x = 0; x < sizeof(Block); ++x) {
229 if ((*p++ = fbp->temp_feed[x]) == IAC)
230 *p++ = IAC;
231 }
232 *p++ = IAC;
233 *p++ = SE;
234 printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
235 net_write(fbp->fb_feed, p - fbp->fb_feed);
236 break;
237 default:
238 return(FAILED);
239 }
240 return(fbp->state[dir-1] = state);
241}
242
243/*
244 * Returns:
245 * -1: some error. Negotiation is done, encryption not ready.
246 * 0: Successful, initial negotiation all done.
247 * 1: successful, negotiation not done yet.
248 */
249 int
250cfb64_is(data, cnt)
251 unsigned char *data;
252 int cnt;
253{
254 return(fb64_is(data, cnt, &fb[CFB]));
255}
256 int
257ofb64_is(data, cnt)
258 unsigned char *data;
259 int cnt;
260{
261 return(fb64_is(data, cnt, &fb[OFB]));
262}
263
264 int
265fb64_is(data, cnt, fbp)
266 unsigned char *data;
267 int cnt;
268 struct fb *fbp;
269{
270 unsigned char *p;
271 register int state = fbp->state[DIR_DECRYPT-1];
272
273 if (cnt-- < 1)
274 goto failure;
275
276 switch (*data++) {
277 case FB64_IV:
278 if (cnt != sizeof(Block)) {
279 if (encrypt_debug_mode)
280 printf("CFB64: initial vector failed on size\r\n");
281 state = FAILED;
282 goto failure;
283 }
284
285 if (encrypt_debug_mode)
286 printf("CFB64: initial vector received\r\n");
287
288 if (encrypt_debug_mode)
289 printf("Initializing Decrypt stream\r\n");
290
291 fb64_stream_iv((void *)data, &fbp->streams[DIR_DECRYPT-1]);
292
293 p = fbp->fb_feed + 3;
294 *p++ = ENCRYPT_REPLY;
295 p++;
296 *p++ = FB64_IV_OK;
297 *p++ = IAC;
298 *p++ = SE;
299 printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
300 net_write(fbp->fb_feed, p - fbp->fb_feed);
301
302 state = fbp->state[DIR_DECRYPT-1] = IN_PROGRESS;
303 break;
304
305 default:
306 if (encrypt_debug_mode) {
307 printf("Unknown option type: %d\r\n", *(data-1));
308 printd(data, cnt);
309 printf("\r\n");
310 }
311 /* FALL THROUGH */
312 failure:
313 /*
314 * We failed. Send an FB64_IV_BAD option
315 * to the other side so it will know that
316 * things failed.
317 */
318 p = fbp->fb_feed + 3;
319 *p++ = ENCRYPT_REPLY;
320 p++;
321 *p++ = FB64_IV_BAD;
322 *p++ = IAC;
323 *p++ = SE;
324 printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
325 net_write(fbp->fb_feed, p - fbp->fb_feed);
326
327 break;
328 }
329 return(fbp->state[DIR_DECRYPT-1] = state);
330}
331
332/*
333 * Returns:
334 * -1: some error. Negotiation is done, encryption not ready.
335 * 0: Successful, initial negotiation all done.
336 * 1: successful, negotiation not done yet.
337 */
338 int
339cfb64_reply(data, cnt)
340 unsigned char *data;
341 int cnt;
342{
343 return(fb64_reply(data, cnt, &fb[CFB]));
344}
345 int
346ofb64_reply(data, cnt)
347 unsigned char *data;
348 int cnt;
349{
350 return(fb64_reply(data, cnt, &fb[OFB]));
351}
352
353
354 int
355fb64_reply(data, cnt, fbp)
356 unsigned char *data;
357 int cnt;
358 struct fb *fbp;
359{
360 register int state = fbp->state[DIR_ENCRYPT-1];
361
362 if (cnt-- < 1)
363 goto failure;
364
365 switch (*data++) {
366 case FB64_IV_OK:
367 fb64_stream_iv(fbp->temp_feed, &fbp->streams[DIR_ENCRYPT-1]);
368 if (state == FAILED)
369 state = IN_PROGRESS;
370 state &= ~NO_RECV_IV;
371 encrypt_send_keyid(DIR_ENCRYPT, (unsigned char *)"\0", 1, 1);
372 break;
373
374 case FB64_IV_BAD:
375 memset(fbp->temp_feed, 0, sizeof(Block));
376 fb64_stream_iv(fbp->temp_feed, &fbp->streams[DIR_ENCRYPT-1]);
377 state = FAILED;
378 break;
379
380 default:
381 if (encrypt_debug_mode) {
382 printf("Unknown option type: %d\r\n", data[-1]);
383 printd(data, cnt);
384 printf("\r\n");
385 }
386 /* FALL THROUGH */
387 failure:
388 state = FAILED;
389 break;
390 }
391 return(fbp->state[DIR_ENCRYPT-1] = state);
392}
393
394 void
395cfb64_session(key, server)
396 Session_Key *key;
397 int server;
398{
399 fb64_session(key, server, &fb[CFB]);
400}
401
402 void
403ofb64_session(key, server)
404 Session_Key *key;
405 int server;
406{
407 fb64_session(key, server, &fb[OFB]);
408}
409
410 static void
411fb64_session(key, server, fbp)
412 Session_Key *key;
413 int server;
414 struct fb *fbp;
415{
416
417 if (!key || key->type != SK_DES) {
418 if (encrypt_debug_mode)
419 printf("Can't set krbdes's session key (%d != %d)\r\n",
420 key ? key->type : -1, SK_DES);
421 return;
422 }
423 memmove((void *)fbp->krbdes_key, (void *)key->data, sizeof(Block));
424
425 fb64_stream_key(fbp->krbdes_key, &fbp->streams[DIR_ENCRYPT-1]);
426 fb64_stream_key(fbp->krbdes_key, &fbp->streams[DIR_DECRYPT-1]);
427
428 if (fbp->once == 0) {
429 des_set_random_generator_seed((Block *)fbp->krbdes_key);
430 fbp->once = 1;
431 }
432 des_key_sched((Block *)fbp->krbdes_key, fbp->krbdes_sched);
433 /*
434 * Now look to see if krbdes_start() was was waiting for
435 * the key to show up. If so, go ahead an call it now
436 * that we have the key.
437 */
438 if (fbp->need_start) {
439 fbp->need_start = 0;
440 fb64_start(fbp, DIR_ENCRYPT, server);
441 }
442}
443
444/*
445 * We only accept a keyid of 0. If we get a keyid of
446 * 0, then mark the state as SUCCESS.
447 */
448 int
449cfb64_keyid(dir, kp, lenp)
450 int dir, *lenp;
451 unsigned char *kp;
452{
453 return(fb64_keyid(dir, kp, lenp, &fb[CFB]));
454}
455
456 int
457ofb64_keyid(dir, kp, lenp)
458 int dir, *lenp;
459 unsigned char *kp;
460{
461 return(fb64_keyid(dir, kp, lenp, &fb[OFB]));
462}
463
464 int
465fb64_keyid(dir, kp, lenp, fbp)
466 int dir, *lenp;
467 unsigned char *kp;
468 struct fb *fbp;
469{
470 register int state = fbp->state[dir-1];
471
472 if (*lenp != 1 || (*kp != '\0')) {
473 *lenp = 0;
474 return(state);
475 }
476
477 if (state == FAILED)
478 state = IN_PROGRESS;
479
480 state &= ~NO_KEYID;
481
482 return(fbp->state[dir-1] = state);
483}
484
485 void
486fb64_printsub(data, cnt, buf, buflen, type)
487 unsigned char *data, *buf, *type;
488 int cnt, buflen;
489{
490 char lbuf[32];
491 register int i;
492 char *cp;
493
494 buf[buflen-1] = '\0'; /* make sure it's NULL terminated */
495 buflen -= 1;
496
497 switch(data[2]) {
498 case FB64_IV:
499 sprintf(lbuf, "%s_IV", type);
500 cp = lbuf;
501 goto common;
502
503 case FB64_IV_OK:
504 sprintf(lbuf, "%s_IV_OK", type);
505 cp = lbuf;
506 goto common;
507
508 case FB64_IV_BAD:
509 sprintf(lbuf, "%s_IV_BAD", type);
510 cp = lbuf;
511 goto common;
512
513 default:
514 sprintf(lbuf, " %d (unknown)", data[2]);
515 cp = lbuf;
516 common:
517 for (; (buflen > 0) && (*buf = *cp++); buf++)
518 buflen--;
519 for (i = 3; i < cnt; i++) {
520 sprintf(lbuf, " %d", data[i]);
521 for (cp = lbuf; (buflen > 0) && (*buf = *cp++); buf++)
522 buflen--;
523 }
524 break;
525 }
526}
527
528 void
529cfb64_printsub(data, cnt, buf, buflen)
530 unsigned char *data, *buf;
531 int cnt, buflen;
532{
533 fb64_printsub(data, cnt, buf, buflen, "CFB64");
534}
535
536 void
537ofb64_printsub(data, cnt, buf, buflen)
538 unsigned char *data, *buf;
539 int cnt, buflen;
540{
541 fb64_printsub(data, cnt, buf, buflen, "OFB64");
542}
543
544 void
545fb64_stream_iv(seed, stp)
546 Block seed;
547 register struct stinfo *stp;
548{
549
550 memmove((void *)stp->str_iv, (void *)seed, sizeof(Block));
551 memmove((void *)stp->str_output, (void *)seed, sizeof(Block));
552
553 des_key_sched((Block *)stp->str_ikey, stp->str_sched);
554
555 stp->str_index = sizeof(Block);
556}
557
558 void
559fb64_stream_key(key, stp)
560 Block key;
561 register struct stinfo *stp;
562{
563 memmove((void *)stp->str_ikey, (void *)key, sizeof(Block));
564 des_key_sched((Block *)key, stp->str_sched);
565
566 memmove((void *)stp->str_output, (void *)stp->str_iv, sizeof(Block));
567
568 stp->str_index = sizeof(Block);
569}
570
571/*
572 * DES 64 bit Cipher Feedback
573 *
574 * key --->+-----+
575 * +->| DES |--+
576 * | +-----+ |
577 * | v
578 * INPUT --(--------->(+)+---> DATA
579 * | |
580 * +-------------+
581 *
582 *
583 * Given:
584 * iV: Initial vector, 64 bits (8 bytes) long.
585 * Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
586 * On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
587 *
588 * V0 = DES(iV, key)
589 * On = Dn ^ Vn
590 * V(n+1) = DES(On, key)
591 */
592
593 void
594cfb64_encrypt(s, c)
595 register unsigned char *s;
596 int c;
597{
598 register struct stinfo *stp = &fb[CFB].streams[DIR_ENCRYPT-1];
599 register int index;
600
601 index = stp->str_index;
602 while (c-- > 0) {
603 if (index == sizeof(Block)) {
604 Block b;
605 des_ecb_encrypt((Block *)stp->str_output, (Block *)b, stp->str_sched, 1);
606 memmove((void *)stp->str_feed, (void *)b, sizeof(Block));
607 index = 0;
608 }
609
610 /* On encryption, we store (feed ^ data) which is cypher */
611 *s = stp->str_output[index] = (stp->str_feed[index] ^ *s);
612 s++;
613 index++;
614 }
615 stp->str_index = index;
616}
617
618 int
619cfb64_decrypt(data)
620 int data;
621{
622 register struct stinfo *stp = &fb[CFB].streams[DIR_DECRYPT-1];
623 int index;
624
625 if (data == -1) {
626 /*
627 * Back up one byte. It is assumed that we will
628 * never back up more than one byte. If we do, this
629 * may or may not work.
630 */
631 if (stp->str_index)
632 --stp->str_index;
633 return(0);
634 }
635
636 index = stp->str_index++;
637 if (index == sizeof(Block)) {
638 Block b;
639 des_ecb_encrypt((Block *)stp->str_output, (Block *)b, stp->str_sched, 1);
640 memmove((void *)stp->str_feed, (void *)b, sizeof(Block));
641 stp->str_index = 1; /* Next time will be 1 */
642 index = 0; /* But now use 0 */
643 }
644
645 /* On decryption we store (data) which is cypher. */
646 stp->str_output[index] = data;
647 return(data ^ stp->str_feed[index]);
648}
649
650/*
651 * DES 64 bit Output Feedback
652 *
653 * key --->+-----+
654 * +->| DES |--+
655 * | +-----+ |
656 * +-----------+
657 * v
658 * INPUT -------->(+) ----> DATA
659 *
660 * Given:
661 * iV: Initial vector, 64 bits (8 bytes) long.
662 * Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
663 * On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
664 *
665 * V0 = DES(iV, key)
666 * V(n+1) = DES(Vn, key)
667 * On = Dn ^ Vn
668 */
669 void
670ofb64_encrypt(s, c)
671 register unsigned char *s;
672 int c;
673{
674 register struct stinfo *stp = &fb[OFB].streams[DIR_ENCRYPT-1];
675 register int index;
676
677 index = stp->str_index;
678 while (c-- > 0) {
679 if (index == sizeof(Block)) {
680 Block b;
681 des_ecb_encrypt((Block *)stp->str_feed, (Block *)b, stp->str_sched, 1);
682 memmove((void *)stp->str_feed, (void *)b, sizeof(Block));
683 index = 0;
684 }
685 *s++ ^= stp->str_feed[index];
686 index++;
687 }
688 stp->str_index = index;
689}
690
691 int
692ofb64_decrypt(data)
693 int data;
694{
695 register struct stinfo *stp = &fb[OFB].streams[DIR_DECRYPT-1];
696 int index;
697
698 if (data == -1) {
699 /*
700 * Back up one byte. It is assumed that we will
701 * never back up more than one byte. If we do, this
702 * may or may not work.
703 */
704 if (stp->str_index)
705 --stp->str_index;
706 return(0);
707 }
708
709 index = stp->str_index++;
710 if (index == sizeof(Block)) {
711 Block b;
712 des_ecb_encrypt((Block *)stp->str_feed, (Block *)b, stp->str_sched, 1);
713 memmove((void *)stp->str_feed, (void *)b, sizeof(Block));
714 stp->str_index = 1; /* Next time will be 1 */
715 index = 0; /* But now use 0 */
716 }
717
718 return(data ^ stp->str_feed[index]);
719}
720# endif /* DES_ENCRYPTION */
721# endif /* AUTHENTICATION */
722#endif /* ENCRYPTION */
| 57
58#define CFB 0
59#define OFB 1
60
61#define NO_SEND_IV 1
62#define NO_RECV_IV 2
63#define NO_KEYID 4
64#define IN_PROGRESS (NO_SEND_IV|NO_RECV_IV|NO_KEYID)
65#define SUCCESS 0
66#define FAILED -1
67
68
69struct fb {
70 Block krbdes_key;
71 Schedule krbdes_sched;
72 Block temp_feed;
73 unsigned char fb_feed[64];
74 int need_start;
75 int state[2];
76 int keyid[2];
77 int once;
78 struct stinfo {
79 Block str_output;
80 Block str_feed;
81 Block str_iv;
82 Block str_ikey;
83 Schedule str_sched;
84 int str_index;
85 int str_flagshift;
86 } streams[2];
87};
88
89static struct fb fb[2];
90
91struct keyidlist {
92 char *keyid;
93 int keyidlen;
94 char *key;
95 int keylen;
96 int flags;
97} keyidlist [] = {
98 { "\0", 1, 0, 0, 0 }, /* default key of zero */
99 { 0, 0, 0, 0, 0 }
100};
101
102#define KEYFLAG_MASK 03
103
104#define KEYFLAG_NOINIT 00
105#define KEYFLAG_INIT 01
106#define KEYFLAG_OK 02
107#define KEYFLAG_BAD 03
108
109#define KEYFLAG_SHIFT 2
110
111#define SHIFT_VAL(a,b) (KEYFLAG_SHIFT*((a)+((b)*2)))
112
113#define FB64_IV 1
114#define FB64_IV_OK 2
115#define FB64_IV_BAD 3
116
117
118void fb64_stream_iv P((Block, struct stinfo *));
119void fb64_init P((struct fb *));
120static int fb64_start P((struct fb *, int, int));
121int fb64_is P((unsigned char *, int, struct fb *));
122int fb64_reply P((unsigned char *, int, struct fb *));
123static void fb64_session P((Session_Key *, int, struct fb *));
124void fb64_stream_key P((Block, struct stinfo *));
125int fb64_keyid P((int, unsigned char *, int *, struct fb *));
126
127 void
128cfb64_init(server)
129 int server;
130{
131 fb64_init(&fb[CFB]);
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);
135}
136
137 void
138ofb64_init(server)
139 int server;
140{
141 fb64_init(&fb[OFB]);
142 fb[OFB].fb_feed[4] = ENCTYPE_DES_OFB64;
143 fb[CFB].streams[0].str_flagshift = SHIFT_VAL(0, OFB);
144 fb[CFB].streams[1].str_flagshift = SHIFT_VAL(1, OFB);
145}
146
147 void
148fb64_init(fbp)
149 register struct fb *fbp;
150{
151 memset((void *)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;
157}
158
159/*
160 * Returns:
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.
166 */
167 int
168cfb64_start(dir, server)
169 int dir;
170 int server;
171{
172 return(fb64_start(&fb[CFB], dir, server));
173}
174 int
175ofb64_start(dir, server)
176 int dir;
177 int server;
178{
179 return(fb64_start(&fb[OFB], dir, server));
180}
181
182 static int
183fb64_start(fbp, dir, server)
184 struct fb *fbp;
185 int dir;
186 int server;
187{
188 int x;
189 unsigned char *p;
190 register int state;
191
192 switch (dir) {
193 case DIR_DECRYPT:
194 /*
195 * This is simply a request to have the other side
196 * start output (our input). He will negotiate an
197 * IV so we need not look for it.
198 */
199 state = fbp->state[dir-1];
200 if (state == FAILED)
201 state = IN_PROGRESS;
202 break;
203
204 case DIR_ENCRYPT:
205 state = fbp->state[dir-1];
206 if (state == FAILED)
207 state = IN_PROGRESS;
208 else if ((state & NO_SEND_IV) == 0)
209 break;
210
211 if (!VALIDKEY(fbp->krbdes_key)) {
212 fbp->need_start = 1;
213 break;
214 }
215 state &= ~NO_SEND_IV;
216 state |= NO_RECV_IV;
217 if (encrypt_debug_mode)
218 printf("Creating new feed\r\n");
219 /*
220 * Create a random feed and send it over.
221 */
222 des_new_random_key((Block *)fbp->temp_feed);
223 des_ecb_encrypt((Block *)fbp->temp_feed, (Block *)fbp->temp_feed,
224 fbp->krbdes_sched, 1);
225 p = fbp->fb_feed + 3;
226 *p++ = ENCRYPT_IS;
227 p++;
228 *p++ = FB64_IV;
229 for (x = 0; x < sizeof(Block); ++x) {
230 if ((*p++ = fbp->temp_feed[x]) == IAC)
231 *p++ = IAC;
232 }
233 *p++ = IAC;
234 *p++ = SE;
235 printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
236 net_write(fbp->fb_feed, p - fbp->fb_feed);
237 break;
238 default:
239 return(FAILED);
240 }
241 return(fbp->state[dir-1] = state);
242}
243
244/*
245 * Returns:
246 * -1: some error. Negotiation is done, encryption not ready.
247 * 0: Successful, initial negotiation all done.
248 * 1: successful, negotiation not done yet.
249 */
250 int
251cfb64_is(data, cnt)
252 unsigned char *data;
253 int cnt;
254{
255 return(fb64_is(data, cnt, &fb[CFB]));
256}
257 int
258ofb64_is(data, cnt)
259 unsigned char *data;
260 int cnt;
261{
262 return(fb64_is(data, cnt, &fb[OFB]));
263}
264
265 int
266fb64_is(data, cnt, fbp)
267 unsigned char *data;
268 int cnt;
269 struct fb *fbp;
270{
271 unsigned char *p;
272 register int state = fbp->state[DIR_DECRYPT-1];
273
274 if (cnt-- < 1)
275 goto failure;
276
277 switch (*data++) {
278 case FB64_IV:
279 if (cnt != sizeof(Block)) {
280 if (encrypt_debug_mode)
281 printf("CFB64: initial vector failed on size\r\n");
282 state = FAILED;
283 goto failure;
284 }
285
286 if (encrypt_debug_mode)
287 printf("CFB64: initial vector received\r\n");
288
289 if (encrypt_debug_mode)
290 printf("Initializing Decrypt stream\r\n");
291
292 fb64_stream_iv((void *)data, &fbp->streams[DIR_DECRYPT-1]);
293
294 p = fbp->fb_feed + 3;
295 *p++ = ENCRYPT_REPLY;
296 p++;
297 *p++ = FB64_IV_OK;
298 *p++ = IAC;
299 *p++ = SE;
300 printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
301 net_write(fbp->fb_feed, p - fbp->fb_feed);
302
303 state = fbp->state[DIR_DECRYPT-1] = IN_PROGRESS;
304 break;
305
306 default:
307 if (encrypt_debug_mode) {
308 printf("Unknown option type: %d\r\n", *(data-1));
309 printd(data, cnt);
310 printf("\r\n");
311 }
312 /* FALL THROUGH */
313 failure:
314 /*
315 * We failed. Send an FB64_IV_BAD option
316 * to the other side so it will know that
317 * things failed.
318 */
319 p = fbp->fb_feed + 3;
320 *p++ = ENCRYPT_REPLY;
321 p++;
322 *p++ = FB64_IV_BAD;
323 *p++ = IAC;
324 *p++ = SE;
325 printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
326 net_write(fbp->fb_feed, p - fbp->fb_feed);
327
328 break;
329 }
330 return(fbp->state[DIR_DECRYPT-1] = state);
331}
332
333/*
334 * Returns:
335 * -1: some error. Negotiation is done, encryption not ready.
336 * 0: Successful, initial negotiation all done.
337 * 1: successful, negotiation not done yet.
338 */
339 int
340cfb64_reply(data, cnt)
341 unsigned char *data;
342 int cnt;
343{
344 return(fb64_reply(data, cnt, &fb[CFB]));
345}
346 int
347ofb64_reply(data, cnt)
348 unsigned char *data;
349 int cnt;
350{
351 return(fb64_reply(data, cnt, &fb[OFB]));
352}
353
354
355 int
356fb64_reply(data, cnt, fbp)
357 unsigned char *data;
358 int cnt;
359 struct fb *fbp;
360{
361 register int state = fbp->state[DIR_ENCRYPT-1];
362
363 if (cnt-- < 1)
364 goto failure;
365
366 switch (*data++) {
367 case FB64_IV_OK:
368 fb64_stream_iv(fbp->temp_feed, &fbp->streams[DIR_ENCRYPT-1]);
369 if (state == FAILED)
370 state = IN_PROGRESS;
371 state &= ~NO_RECV_IV;
372 encrypt_send_keyid(DIR_ENCRYPT, (unsigned char *)"\0", 1, 1);
373 break;
374
375 case FB64_IV_BAD:
376 memset(fbp->temp_feed, 0, sizeof(Block));
377 fb64_stream_iv(fbp->temp_feed, &fbp->streams[DIR_ENCRYPT-1]);
378 state = FAILED;
379 break;
380
381 default:
382 if (encrypt_debug_mode) {
383 printf("Unknown option type: %d\r\n", data[-1]);
384 printd(data, cnt);
385 printf("\r\n");
386 }
387 /* FALL THROUGH */
388 failure:
389 state = FAILED;
390 break;
391 }
392 return(fbp->state[DIR_ENCRYPT-1] = state);
393}
394
395 void
396cfb64_session(key, server)
397 Session_Key *key;
398 int server;
399{
400 fb64_session(key, server, &fb[CFB]);
401}
402
403 void
404ofb64_session(key, server)
405 Session_Key *key;
406 int server;
407{
408 fb64_session(key, server, &fb[OFB]);
409}
410
411 static void
412fb64_session(key, server, fbp)
413 Session_Key *key;
414 int server;
415 struct fb *fbp;
416{
417
418 if (!key || key->type != SK_DES) {
419 if (encrypt_debug_mode)
420 printf("Can't set krbdes's session key (%d != %d)\r\n",
421 key ? key->type : -1, SK_DES);
422 return;
423 }
424 memmove((void *)fbp->krbdes_key, (void *)key->data, sizeof(Block));
425
426 fb64_stream_key(fbp->krbdes_key, &fbp->streams[DIR_ENCRYPT-1]);
427 fb64_stream_key(fbp->krbdes_key, &fbp->streams[DIR_DECRYPT-1]);
428
429 if (fbp->once == 0) {
430 des_set_random_generator_seed((Block *)fbp->krbdes_key);
431 fbp->once = 1;
432 }
433 des_key_sched((Block *)fbp->krbdes_key, fbp->krbdes_sched);
434 /*
435 * Now look to see if krbdes_start() was was waiting for
436 * the key to show up. If so, go ahead an call it now
437 * that we have the key.
438 */
439 if (fbp->need_start) {
440 fbp->need_start = 0;
441 fb64_start(fbp, DIR_ENCRYPT, server);
442 }
443}
444
445/*
446 * We only accept a keyid of 0. If we get a keyid of
447 * 0, then mark the state as SUCCESS.
448 */
449 int
450cfb64_keyid(dir, kp, lenp)
451 int dir, *lenp;
452 unsigned char *kp;
453{
454 return(fb64_keyid(dir, kp, lenp, &fb[CFB]));
455}
456
457 int
458ofb64_keyid(dir, kp, lenp)
459 int dir, *lenp;
460 unsigned char *kp;
461{
462 return(fb64_keyid(dir, kp, lenp, &fb[OFB]));
463}
464
465 int
466fb64_keyid(dir, kp, lenp, fbp)
467 int dir, *lenp;
468 unsigned char *kp;
469 struct fb *fbp;
470{
471 register int state = fbp->state[dir-1];
472
473 if (*lenp != 1 || (*kp != '\0')) {
474 *lenp = 0;
475 return(state);
476 }
477
478 if (state == FAILED)
479 state = IN_PROGRESS;
480
481 state &= ~NO_KEYID;
482
483 return(fbp->state[dir-1] = state);
484}
485
486 void
487fb64_printsub(data, cnt, buf, buflen, type)
488 unsigned char *data, *buf, *type;
489 int cnt, buflen;
490{
491 char lbuf[32];
492 register int i;
493 char *cp;
494
495 buf[buflen-1] = '\0'; /* make sure it's NULL terminated */
496 buflen -= 1;
497
498 switch(data[2]) {
499 case FB64_IV:
500 sprintf(lbuf, "%s_IV", type);
501 cp = lbuf;
502 goto common;
503
504 case FB64_IV_OK:
505 sprintf(lbuf, "%s_IV_OK", type);
506 cp = lbuf;
507 goto common;
508
509 case FB64_IV_BAD:
510 sprintf(lbuf, "%s_IV_BAD", type);
511 cp = lbuf;
512 goto common;
513
514 default:
515 sprintf(lbuf, " %d (unknown)", data[2]);
516 cp = lbuf;
517 common:
518 for (; (buflen > 0) && (*buf = *cp++); buf++)
519 buflen--;
520 for (i = 3; i < cnt; i++) {
521 sprintf(lbuf, " %d", data[i]);
522 for (cp = lbuf; (buflen > 0) && (*buf = *cp++); buf++)
523 buflen--;
524 }
525 break;
526 }
527}
528
529 void
530cfb64_printsub(data, cnt, buf, buflen)
531 unsigned char *data, *buf;
532 int cnt, buflen;
533{
534 fb64_printsub(data, cnt, buf, buflen, "CFB64");
535}
536
537 void
538ofb64_printsub(data, cnt, buf, buflen)
539 unsigned char *data, *buf;
540 int cnt, buflen;
541{
542 fb64_printsub(data, cnt, buf, buflen, "OFB64");
543}
544
545 void
546fb64_stream_iv(seed, stp)
547 Block seed;
548 register struct stinfo *stp;
549{
550
551 memmove((void *)stp->str_iv, (void *)seed, sizeof(Block));
552 memmove((void *)stp->str_output, (void *)seed, sizeof(Block));
553
554 des_key_sched((Block *)stp->str_ikey, stp->str_sched);
555
556 stp->str_index = sizeof(Block);
557}
558
559 void
560fb64_stream_key(key, stp)
561 Block key;
562 register struct stinfo *stp;
563{
564 memmove((void *)stp->str_ikey, (void *)key, sizeof(Block));
565 des_key_sched((Block *)key, stp->str_sched);
566
567 memmove((void *)stp->str_output, (void *)stp->str_iv, sizeof(Block));
568
569 stp->str_index = sizeof(Block);
570}
571
572/*
573 * DES 64 bit Cipher Feedback
574 *
575 * key --->+-----+
576 * +->| DES |--+
577 * | +-----+ |
578 * | v
579 * INPUT --(--------->(+)+---> DATA
580 * | |
581 * +-------------+
582 *
583 *
584 * Given:
585 * iV: Initial vector, 64 bits (8 bytes) long.
586 * Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
587 * On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
588 *
589 * V0 = DES(iV, key)
590 * On = Dn ^ Vn
591 * V(n+1) = DES(On, key)
592 */
593
594 void
595cfb64_encrypt(s, c)
596 register unsigned char *s;
597 int c;
598{
599 register struct stinfo *stp = &fb[CFB].streams[DIR_ENCRYPT-1];
600 register int index;
601
602 index = stp->str_index;
603 while (c-- > 0) {
604 if (index == sizeof(Block)) {
605 Block b;
606 des_ecb_encrypt((Block *)stp->str_output, (Block *)b, stp->str_sched, 1);
607 memmove((void *)stp->str_feed, (void *)b, sizeof(Block));
608 index = 0;
609 }
610
611 /* On encryption, we store (feed ^ data) which is cypher */
612 *s = stp->str_output[index] = (stp->str_feed[index] ^ *s);
613 s++;
614 index++;
615 }
616 stp->str_index = index;
617}
618
619 int
620cfb64_decrypt(data)
621 int data;
622{
623 register struct stinfo *stp = &fb[CFB].streams[DIR_DECRYPT-1];
624 int index;
625
626 if (data == -1) {
627 /*
628 * Back up one byte. It is assumed that we will
629 * never back up more than one byte. If we do, this
630 * may or may not work.
631 */
632 if (stp->str_index)
633 --stp->str_index;
634 return(0);
635 }
636
637 index = stp->str_index++;
638 if (index == sizeof(Block)) {
639 Block b;
640 des_ecb_encrypt((Block *)stp->str_output, (Block *)b, stp->str_sched, 1);
641 memmove((void *)stp->str_feed, (void *)b, sizeof(Block));
642 stp->str_index = 1; /* Next time will be 1 */
643 index = 0; /* But now use 0 */
644 }
645
646 /* On decryption we store (data) which is cypher. */
647 stp->str_output[index] = data;
648 return(data ^ stp->str_feed[index]);
649}
650
651/*
652 * DES 64 bit Output Feedback
653 *
654 * key --->+-----+
655 * +->| DES |--+
656 * | +-----+ |
657 * +-----------+
658 * v
659 * INPUT -------->(+) ----> DATA
660 *
661 * Given:
662 * iV: Initial vector, 64 bits (8 bytes) long.
663 * Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
664 * On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
665 *
666 * V0 = DES(iV, key)
667 * V(n+1) = DES(Vn, key)
668 * On = Dn ^ Vn
669 */
670 void
671ofb64_encrypt(s, c)
672 register unsigned char *s;
673 int c;
674{
675 register struct stinfo *stp = &fb[OFB].streams[DIR_ENCRYPT-1];
676 register int index;
677
678 index = stp->str_index;
679 while (c-- > 0) {
680 if (index == sizeof(Block)) {
681 Block b;
682 des_ecb_encrypt((Block *)stp->str_feed, (Block *)b, stp->str_sched, 1);
683 memmove((void *)stp->str_feed, (void *)b, sizeof(Block));
684 index = 0;
685 }
686 *s++ ^= stp->str_feed[index];
687 index++;
688 }
689 stp->str_index = index;
690}
691
692 int
693ofb64_decrypt(data)
694 int data;
695{
696 register struct stinfo *stp = &fb[OFB].streams[DIR_DECRYPT-1];
697 int index;
698
699 if (data == -1) {
700 /*
701 * Back up one byte. It is assumed that we will
702 * never back up more than one byte. If we do, this
703 * may or may not work.
704 */
705 if (stp->str_index)
706 --stp->str_index;
707 return(0);
708 }
709
710 index = stp->str_index++;
711 if (index == sizeof(Block)) {
712 Block b;
713 des_ecb_encrypt((Block *)stp->str_feed, (Block *)b, stp->str_sched, 1);
714 memmove((void *)stp->str_feed, (void *)b, sizeof(Block));
715 stp->str_index = 1; /* Next time will be 1 */
716 index = 0; /* But now use 0 */
717 }
718
719 return(data ^ stp->str_feed[index]);
720}
721# endif /* DES_ENCRYPTION */
722# endif /* AUTHENTICATION */
723#endif /* ENCRYPTION */
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