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29 * $FreeBSD: src/crypto/telnet/libtelnet/enc_des.c,v 1.3.2.2 2003/02/14 22:38:13 nectar Exp $
30 * $DragonFly: src/crypto/telnet/libtelnet/enc_des.c,v 1.2 2003/06/17 04:24:37 dillon Exp $
32 * @(#)enc_des.c 8.3 (Berkeley) 5/30/95
33 * $FreeBSD: src/crypto/telnet/libtelnet/enc_des.c,v 1.3.2.2 2003/02/14 22:38:13 nectar Exp $
37 # ifdef AUTHENTICATION
38 #include <arpa/telnet.h>
39 #include <openssl/des.h>
45 #include "key-proto.h"
46 #include "misc-proto.h"
48 extern int encrypt_debug_mode;
56 #define IN_PROGRESS (NO_SEND_IV|NO_RECV_IV|NO_KEYID)
63 Schedule krbdes_sched;
65 unsigned char fb_feed[64];
80 static struct fb fb[2];
89 { "\0", 1, 0, 0, 0 }, /* default key of zero */
93 #define KEYFLAG_MASK 03
95 #define KEYFLAG_NOINIT 00
96 #define KEYFLAG_INIT 01
98 #define KEYFLAG_BAD 03
100 #define KEYFLAG_SHIFT 2
102 #define SHIFT_VAL(a,b) (KEYFLAG_SHIFT*((a)+((b)*2)))
106 #define FB64_IV_BAD 3
109 void fb64_stream_iv(Block, struct stinfo *);
110 void fb64_init(struct fb *);
111 static int fb64_start(struct fb *, int, int);
112 int fb64_is(unsigned char *, int, struct fb *);
113 int fb64_reply(unsigned char *, int, struct fb *);
114 static void fb64_session(Session_Key *, int, struct fb *);
115 void fb64_stream_key(Block, struct stinfo *);
116 int fb64_keyid(int, unsigned char *, int *, struct fb *);
119 cfb64_init(int server __unused)
122 fb[CFB].fb_feed[4] = ENCTYPE_DES_CFB64;
123 fb[CFB].streams[0].str_flagshift = SHIFT_VAL(0, CFB);
124 fb[CFB].streams[1].str_flagshift = SHIFT_VAL(1, CFB);
128 ofb64_init(int server __unused)
131 fb[OFB].fb_feed[4] = ENCTYPE_DES_OFB64;
132 fb[CFB].streams[0].str_flagshift = SHIFT_VAL(0, OFB);
133 fb[CFB].streams[1].str_flagshift = SHIFT_VAL(1, OFB);
137 fb64_init(struct fb *fbp)
139 memset((void *)fbp, 0, sizeof(*fbp));
140 fbp->state[0] = fbp->state[1] = FAILED;
141 fbp->fb_feed[0] = IAC;
142 fbp->fb_feed[1] = SB;
143 fbp->fb_feed[2] = TELOPT_ENCRYPT;
144 fbp->fb_feed[3] = ENCRYPT_IS;
149 * -1: some error. Negotiation is done, encryption not ready.
150 * 0: Successful, initial negotiation all done.
151 * 1: successful, negotiation not done yet.
152 * 2: Not yet. Other things (like getting the key from
153 * Kerberos) have to happen before we can continue.
156 cfb64_start(int dir, int server)
158 return(fb64_start(&fb[CFB], dir, server));
162 ofb64_start(int dir, int server)
164 return(fb64_start(&fb[OFB], dir, server));
168 fb64_start(struct fb *fbp, int dir, int server __unused)
177 * This is simply a request to have the other side
178 * start output (our input). He will negotiate an
179 * IV so we need not look for it.
181 state = fbp->state[dir-1];
187 state = fbp->state[dir-1];
190 else if ((state & NO_SEND_IV) == 0)
193 if (!VALIDKEY(fbp->krbdes_key)) {
197 state &= ~NO_SEND_IV;
199 if (encrypt_debug_mode)
200 printf("Creating new feed\r\n");
202 * Create a random feed and send it over.
204 des_random_key((Block *)fbp->temp_feed);
205 des_ecb_encrypt((Block *)fbp->temp_feed, (Block *)fbp->temp_feed,
206 fbp->krbdes_sched, 1);
207 p = fbp->fb_feed + 3;
211 for (x = 0; x < sizeof(Block); ++x) {
212 if ((*p++ = fbp->temp_feed[x]) == IAC)
217 printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
218 net_write(fbp->fb_feed, p - fbp->fb_feed);
223 return(fbp->state[dir-1] = state);
228 * -1: some error. Negotiation is done, encryption not ready.
229 * 0: Successful, initial negotiation all done.
230 * 1: successful, negotiation not done yet.
233 cfb64_is(unsigned char *data, int cnt)
235 return(fb64_is(data, cnt, &fb[CFB]));
239 ofb64_is(unsigned char *data, int cnt)
241 return(fb64_is(data, cnt, &fb[OFB]));
245 fb64_is(unsigned char *data, int cnt, struct fb *fbp)
248 int state = fbp->state[DIR_DECRYPT-1];
255 if (cnt != sizeof(Block)) {
256 if (encrypt_debug_mode)
257 printf("CFB64: initial vector failed on size\r\n");
262 if (encrypt_debug_mode)
263 printf("CFB64: initial vector received\r\n");
265 if (encrypt_debug_mode)
266 printf("Initializing Decrypt stream\r\n");
268 fb64_stream_iv((void *)data, &fbp->streams[DIR_DECRYPT-1]);
270 p = fbp->fb_feed + 3;
271 *p++ = ENCRYPT_REPLY;
276 printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
277 net_write(fbp->fb_feed, p - fbp->fb_feed);
279 state = fbp->state[DIR_DECRYPT-1] = IN_PROGRESS;
283 if (encrypt_debug_mode) {
284 printf("Unknown option type: %d\r\n", *(data-1));
291 * We failed. Send an FB64_IV_BAD option
292 * to the other side so it will know that
295 p = fbp->fb_feed + 3;
296 *p++ = ENCRYPT_REPLY;
301 printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
302 net_write(fbp->fb_feed, p - fbp->fb_feed);
306 return(fbp->state[DIR_DECRYPT-1] = state);
311 * -1: some error. Negotiation is done, encryption not ready.
312 * 0: Successful, initial negotiation all done.
313 * 1: successful, negotiation not done yet.
316 cfb64_reply(unsigned char *data, int cnt)
318 return(fb64_reply(data, cnt, &fb[CFB]));
322 ofb64_reply(unsigned char *data, int cnt)
324 return(fb64_reply(data, cnt, &fb[OFB]));
328 fb64_reply(unsigned char *data, int cnt, struct fb *fbp)
330 int state = fbp->state[DIR_ENCRYPT-1];
337 fb64_stream_iv(fbp->temp_feed, &fbp->streams[DIR_ENCRYPT-1]);
340 state &= ~NO_RECV_IV;
341 encrypt_send_keyid(DIR_ENCRYPT, "\0", 1, 1);
345 memset(fbp->temp_feed, 0, sizeof(Block));
346 fb64_stream_iv(fbp->temp_feed, &fbp->streams[DIR_ENCRYPT-1]);
351 if (encrypt_debug_mode) {
352 printf("Unknown option type: %d\r\n", data[-1]);
361 return(fbp->state[DIR_ENCRYPT-1] = state);
365 cfb64_session(Session_Key *key, int server)
367 fb64_session(key, server, &fb[CFB]);
371 ofb64_session(Session_Key *key, int server)
373 fb64_session(key, server, &fb[OFB]);
377 fb64_session(Session_Key *key, int server, struct fb *fbp)
379 if (!key || key->type != SK_DES) {
380 if (encrypt_debug_mode)
381 printf("Can't set krbdes's session key (%d != %d)\r\n",
382 key ? key->type : -1, SK_DES);
385 memmove((void *)fbp->krbdes_key, (void *)key->data, sizeof(Block));
387 fb64_stream_key(fbp->krbdes_key, &fbp->streams[DIR_ENCRYPT-1]);
388 fb64_stream_key(fbp->krbdes_key, &fbp->streams[DIR_DECRYPT-1]);
390 des_key_sched((Block *)fbp->krbdes_key, fbp->krbdes_sched);
392 * Now look to see if krbdes_start() was was waiting for
393 * the key to show up. If so, go ahead an call it now
394 * that we have the key.
396 if (fbp->need_start) {
398 fb64_start(fbp, DIR_ENCRYPT, server);
403 * We only accept a keyid of 0. If we get a keyid of
404 * 0, then mark the state as SUCCESS.
407 cfb64_keyid(int dir, unsigned char *kp, int *lenp)
409 return(fb64_keyid(dir, kp, lenp, &fb[CFB]));
413 ofb64_keyid(int dir, unsigned char *kp, int *lenp)
415 return(fb64_keyid(dir, kp, lenp, &fb[OFB]));
419 fb64_keyid(int dir, unsigned char *kp, int *lenp, struct fb *fbp)
421 int state = fbp->state[dir-1];
423 if (*lenp != 1 || (*kp != '\0')) {
433 return(fbp->state[dir-1] = state);
437 fb64_printsub(unsigned char *data, int cnt, unsigned char *buf, int buflen, const char *type)
443 buf[buflen-1] = '\0'; /* make sure it's NULL terminated */
448 sprintf(lbuf, "%s_IV", type);
453 sprintf(lbuf, "%s_IV_OK", type);
458 sprintf(lbuf, "%s_IV_BAD", type);
463 sprintf(lbuf, " %d (unknown)", data[2]);
466 for (; (buflen > 0) && (*buf = *cp++); buf++)
468 for (i = 3; i < cnt; i++) {
469 sprintf(lbuf, " %d", data[i]);
470 for (cp = lbuf; (buflen > 0) && (*buf = *cp++); buf++)
478 cfb64_printsub(unsigned char *data, int cnt, unsigned char *buf, int buflen)
480 fb64_printsub(data, cnt, buf, buflen, "CFB64");
484 ofb64_printsub(unsigned char *data, int cnt, unsigned char *buf, int buflen)
486 fb64_printsub(data, cnt, buf, buflen, "OFB64");
490 fb64_stream_iv(Block seed, struct stinfo *stp)
493 memmove((void *)stp->str_iv, (void *)seed, sizeof(Block));
494 memmove((void *)stp->str_output, (void *)seed, sizeof(Block));
496 des_key_sched((Block *)stp->str_ikey, stp->str_sched);
498 stp->str_index = sizeof(Block);
502 fb64_stream_key(Block key, struct stinfo *stp)
504 memmove((void *)stp->str_ikey, (void *)key, sizeof(Block));
505 des_key_sched((Block *)key, stp->str_sched);
507 memmove((void *)stp->str_output, (void *)stp->str_iv, sizeof(Block));
509 stp->str_index = sizeof(Block);
513 * DES 64 bit Cipher Feedback
519 * INPUT --(--------->(+)+---> DATA
525 * iV: Initial vector, 64 bits (8 bytes) long.
526 * Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
527 * On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
531 * V(n+1) = DES(On, key)
535 cfb64_encrypt(unsigned char *s, int c)
537 struct stinfo *stp = &fb[CFB].streams[DIR_ENCRYPT-1];
540 idx = stp->str_index;
542 if (idx == sizeof(Block)) {
544 des_ecb_encrypt((Block *)stp->str_output, (Block *)b, stp->str_sched, 1);
545 memmove((void *)stp->str_feed, (void *)b, sizeof(Block));
549 /* On encryption, we store (feed ^ data) which is cypher */
550 *s = stp->str_output[idx] = (stp->str_feed[idx] ^ *s);
554 stp->str_index = idx;
558 cfb64_decrypt(int data)
560 struct stinfo *stp = &fb[CFB].streams[DIR_DECRYPT-1];
565 * Back up one byte. It is assumed that we will
566 * never back up more than one byte. If we do, this
567 * may or may not work.
574 idx = stp->str_index++;
575 if (idx == sizeof(Block)) {
577 des_ecb_encrypt((Block *)stp->str_output, (Block *)b, stp->str_sched, 1);
578 memmove((void *)stp->str_feed, (void *)b, sizeof(Block));
579 stp->str_index = 1; /* Next time will be 1 */
580 idx = 0; /* But now use 0 */
583 /* On decryption we store (data) which is cypher. */
584 stp->str_output[idx] = data;
585 return(data ^ stp->str_feed[idx]);
589 * DES 64 bit Output Feedback
596 * INPUT -------->(+) ----> DATA
599 * iV: Initial vector, 64 bits (8 bytes) long.
600 * Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
601 * On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
604 * V(n+1) = DES(Vn, key)
608 ofb64_encrypt(unsigned char *s, int c)
610 struct stinfo *stp = &fb[OFB].streams[DIR_ENCRYPT-1];
613 idx = stp->str_index;
615 if (idx == sizeof(Block)) {
617 des_ecb_encrypt((Block *)stp->str_feed, (Block *)b, stp->str_sched, 1);
618 memmove((void *)stp->str_feed, (void *)b, sizeof(Block));
621 *s++ ^= stp->str_feed[idx];
624 stp->str_index = idx;
628 ofb64_decrypt(int data)
630 struct stinfo *stp = &fb[OFB].streams[DIR_DECRYPT-1];
635 * Back up one byte. It is assumed that we will
636 * never back up more than one byte. If we do, this
637 * may or may not work.
644 idx = stp->str_index++;
645 if (idx == sizeof(Block)) {
647 des_ecb_encrypt((Block *)stp->str_feed, (Block *)b, stp->str_sched, 1);
648 memmove((void *)stp->str_feed, (void *)b, sizeof(Block));
649 stp->str_index = 1; /* Next time will be 1 */
650 idx = 0; /* But now use 0 */
653 return(data ^ stp->str_feed[idx]);
655 # endif /* AUTHENTICATION */
656 #endif /* ENCRYPTION */