[TCPIP]
[reactos.git] / reactos / lib / drivers / lwip / src / netif / ppp / chap.c
1 /*** WARNING - THIS HAS NEVER BEEN FINISHED ***/
2 /*****************************************************************************
3 * chap.c - Network Challenge Handshake Authentication Protocol program file.
4 *
5 * Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
6 * portions Copyright (c) 1997 by Global Election Systems Inc.
7 *
8 * The authors hereby grant permission to use, copy, modify, distribute,
9 * and license this software and its documentation for any purpose, provided
10 * that existing copyright notices are retained in all copies and that this
11 * notice and the following disclaimer are included verbatim in any
12 * distributions. No written agreement, license, or royalty fee is required
13 * for any of the authorized uses.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 ******************************************************************************
27 * REVISION HISTORY
28 *
29 * 03-01-01 Marc Boucher <marc@mbsi.ca>
30 * Ported to lwIP.
31 * 97-12-04 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
32 * Original based on BSD chap.c.
33 *****************************************************************************/
34 /*
35 * chap.c - Challenge Handshake Authentication Protocol.
36 *
37 * Copyright (c) 1993 The Australian National University.
38 * All rights reserved.
39 *
40 * Redistribution and use in source and binary forms are permitted
41 * provided that the above copyright notice and this paragraph are
42 * duplicated in all such forms and that any documentation,
43 * advertising materials, and other materials related to such
44 * distribution and use acknowledge that the software was developed
45 * by the Australian National University. The name of the University
46 * may not be used to endorse or promote products derived from this
47 * software without specific prior written permission.
48 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
49 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
50 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
51 *
52 * Copyright (c) 1991 Gregory M. Christy.
53 * All rights reserved.
54 *
55 * Redistribution and use in source and binary forms are permitted
56 * provided that the above copyright notice and this paragraph are
57 * duplicated in all such forms and that any documentation,
58 * advertising materials, and other materials related to such
59 * distribution and use acknowledge that the software was developed
60 * by Gregory M. Christy. The name of the author may not be used to
61 * endorse or promote products derived from this software without
62 * specific prior written permission.
63 *
64 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
65 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
66 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
67 */
68
69 #include "lwip/opt.h"
70
71 #if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */
72
73 #if CHAP_SUPPORT /* don't build if not configured for use in lwipopts.h */
74
75 #include "ppp.h"
76 #include "pppdebug.h"
77
78 #include "magic.h"
79 #include "randm.h"
80 #include "auth.h"
81 #include "md5.h"
82 #include "chap.h"
83 #include "chpms.h"
84
85 #include <string.h>
86
87 #if 0 /* UNUSED */
88 /*
89 * Command-line options.
90 */
91 static option_t chap_option_list[] = {
92 { "chap-restart", o_int, &chap[0].timeouttime,
93 "Set timeout for CHAP" },
94 { "chap-max-challenge", o_int, &chap[0].max_transmits,
95 "Set max #xmits for challenge" },
96 { "chap-interval", o_int, &chap[0].chal_interval,
97 "Set interval for rechallenge" },
98 #ifdef MSLANMAN
99 { "ms-lanman", o_bool, &ms_lanman,
100 "Use LanMan passwd when using MS-CHAP", 1 },
101 #endif
102 { NULL }
103 };
104 #endif /* UNUSED */
105
106 /*
107 * Protocol entry points.
108 */
109 static void ChapInit (int);
110 static void ChapLowerUp (int);
111 static void ChapLowerDown (int);
112 static void ChapInput (int, u_char *, int);
113 static void ChapProtocolReject (int);
114 #if PPP_ADDITIONAL_CALLBACKS
115 static int ChapPrintPkt (u_char *, int, void (*) (void *, char *, ...), void *);
116 #endif
117
118 struct protent chap_protent = {
119 PPP_CHAP,
120 ChapInit,
121 ChapInput,
122 ChapProtocolReject,
123 ChapLowerUp,
124 ChapLowerDown,
125 NULL,
126 NULL,
127 #if PPP_ADDITIONAL_CALLBACKS
128 ChapPrintPkt,
129 NULL,
130 #endif /* PPP_ADDITIONAL_CALLBACKS */
131 1,
132 "CHAP",
133 #if PPP_ADDITIONAL_CALLBACKS
134 NULL,
135 NULL,
136 NULL
137 #endif /* PPP_ADDITIONAL_CALLBACKS */
138 };
139
140 chap_state chap[NUM_PPP]; /* CHAP state; one for each unit */
141
142 static void ChapChallengeTimeout (void *);
143 static void ChapResponseTimeout (void *);
144 static void ChapReceiveChallenge (chap_state *, u_char *, u_char, int);
145 static void ChapRechallenge (void *);
146 static void ChapReceiveResponse (chap_state *, u_char *, int, int);
147 static void ChapReceiveSuccess(chap_state *cstate, u_char *inp, u_char id, int len);
148 static void ChapReceiveFailure(chap_state *cstate, u_char *inp, u_char id, int len);
149 static void ChapSendStatus (chap_state *, int);
150 static void ChapSendChallenge (chap_state *);
151 static void ChapSendResponse (chap_state *);
152 static void ChapGenChallenge (chap_state *);
153
154 /*
155 * ChapInit - Initialize a CHAP unit.
156 */
157 static void
158 ChapInit(int unit)
159 {
160 chap_state *cstate = &chap[unit];
161
162 BZERO(cstate, sizeof(*cstate));
163 cstate->unit = unit;
164 cstate->clientstate = CHAPCS_INITIAL;
165 cstate->serverstate = CHAPSS_INITIAL;
166 cstate->timeouttime = CHAP_DEFTIMEOUT;
167 cstate->max_transmits = CHAP_DEFTRANSMITS;
168 /* random number generator is initialized in magic_init */
169 }
170
171
172 /*
173 * ChapAuthWithPeer - Authenticate us with our peer (start client).
174 *
175 */
176 void
177 ChapAuthWithPeer(int unit, char *our_name, u_char digest)
178 {
179 chap_state *cstate = &chap[unit];
180
181 cstate->resp_name = our_name;
182 cstate->resp_type = digest;
183
184 if (cstate->clientstate == CHAPCS_INITIAL ||
185 cstate->clientstate == CHAPCS_PENDING) {
186 /* lower layer isn't up - wait until later */
187 cstate->clientstate = CHAPCS_PENDING;
188 return;
189 }
190
191 /*
192 * We get here as a result of LCP coming up.
193 * So even if CHAP was open before, we will
194 * have to re-authenticate ourselves.
195 */
196 cstate->clientstate = CHAPCS_LISTEN;
197 }
198
199
200 /*
201 * ChapAuthPeer - Authenticate our peer (start server).
202 */
203 void
204 ChapAuthPeer(int unit, char *our_name, u_char digest)
205 {
206 chap_state *cstate = &chap[unit];
207
208 cstate->chal_name = our_name;
209 cstate->chal_type = digest;
210
211 if (cstate->serverstate == CHAPSS_INITIAL ||
212 cstate->serverstate == CHAPSS_PENDING) {
213 /* lower layer isn't up - wait until later */
214 cstate->serverstate = CHAPSS_PENDING;
215 return;
216 }
217
218 ChapGenChallenge(cstate);
219 ChapSendChallenge(cstate); /* crank it up dude! */
220 cstate->serverstate = CHAPSS_INITIAL_CHAL;
221 }
222
223
224 /*
225 * ChapChallengeTimeout - Timeout expired on sending challenge.
226 */
227 static void
228 ChapChallengeTimeout(void *arg)
229 {
230 chap_state *cstate = (chap_state *) arg;
231
232 /* if we aren't sending challenges, don't worry. then again we */
233 /* probably shouldn't be here either */
234 if (cstate->serverstate != CHAPSS_INITIAL_CHAL &&
235 cstate->serverstate != CHAPSS_RECHALLENGE) {
236 return;
237 }
238
239 if (cstate->chal_transmits >= cstate->max_transmits) {
240 /* give up on peer */
241 CHAPDEBUG(LOG_ERR, ("Peer failed to respond to CHAP challenge\n"));
242 cstate->serverstate = CHAPSS_BADAUTH;
243 auth_peer_fail(cstate->unit, PPP_CHAP);
244 return;
245 }
246
247 ChapSendChallenge(cstate); /* Re-send challenge */
248 }
249
250
251 /*
252 * ChapResponseTimeout - Timeout expired on sending response.
253 */
254 static void
255 ChapResponseTimeout(void *arg)
256 {
257 chap_state *cstate = (chap_state *) arg;
258
259 /* if we aren't sending a response, don't worry. */
260 if (cstate->clientstate != CHAPCS_RESPONSE) {
261 return;
262 }
263
264 ChapSendResponse(cstate); /* re-send response */
265 }
266
267
268 /*
269 * ChapRechallenge - Time to challenge the peer again.
270 */
271 static void
272 ChapRechallenge(void *arg)
273 {
274 chap_state *cstate = (chap_state *) arg;
275
276 /* if we aren't sending a response, don't worry. */
277 if (cstate->serverstate != CHAPSS_OPEN) {
278 return;
279 }
280
281 ChapGenChallenge(cstate);
282 ChapSendChallenge(cstate);
283 cstate->serverstate = CHAPSS_RECHALLENGE;
284 }
285
286
287 /*
288 * ChapLowerUp - The lower layer is up.
289 *
290 * Start up if we have pending requests.
291 */
292 static void
293 ChapLowerUp(int unit)
294 {
295 chap_state *cstate = &chap[unit];
296
297 if (cstate->clientstate == CHAPCS_INITIAL) {
298 cstate->clientstate = CHAPCS_CLOSED;
299 } else if (cstate->clientstate == CHAPCS_PENDING) {
300 cstate->clientstate = CHAPCS_LISTEN;
301 }
302
303 if (cstate->serverstate == CHAPSS_INITIAL) {
304 cstate->serverstate = CHAPSS_CLOSED;
305 } else if (cstate->serverstate == CHAPSS_PENDING) {
306 ChapGenChallenge(cstate);
307 ChapSendChallenge(cstate);
308 cstate->serverstate = CHAPSS_INITIAL_CHAL;
309 }
310 }
311
312
313 /*
314 * ChapLowerDown - The lower layer is down.
315 *
316 * Cancel all timeouts.
317 */
318 static void
319 ChapLowerDown(int unit)
320 {
321 chap_state *cstate = &chap[unit];
322
323 /* Timeout(s) pending? Cancel if so. */
324 if (cstate->serverstate == CHAPSS_INITIAL_CHAL ||
325 cstate->serverstate == CHAPSS_RECHALLENGE) {
326 UNTIMEOUT(ChapChallengeTimeout, cstate);
327 } else if (cstate->serverstate == CHAPSS_OPEN
328 && cstate->chal_interval != 0) {
329 UNTIMEOUT(ChapRechallenge, cstate);
330 }
331 if (cstate->clientstate == CHAPCS_RESPONSE) {
332 UNTIMEOUT(ChapResponseTimeout, cstate);
333 }
334 cstate->clientstate = CHAPCS_INITIAL;
335 cstate->serverstate = CHAPSS_INITIAL;
336 }
337
338
339 /*
340 * ChapProtocolReject - Peer doesn't grok CHAP.
341 */
342 static void
343 ChapProtocolReject(int unit)
344 {
345 chap_state *cstate = &chap[unit];
346
347 if (cstate->serverstate != CHAPSS_INITIAL &&
348 cstate->serverstate != CHAPSS_CLOSED) {
349 auth_peer_fail(unit, PPP_CHAP);
350 }
351 if (cstate->clientstate != CHAPCS_INITIAL &&
352 cstate->clientstate != CHAPCS_CLOSED) {
353 auth_withpeer_fail(unit, PPP_CHAP); /* lwip: just sets the PPP error code on this unit to PPPERR_AUTHFAIL */
354 }
355 ChapLowerDown(unit); /* shutdown chap */
356 }
357
358
359 /*
360 * ChapInput - Input CHAP packet.
361 */
362 static void
363 ChapInput(int unit, u_char *inpacket, int packet_len)
364 {
365 chap_state *cstate = &chap[unit];
366 u_char *inp;
367 u_char code, id;
368 int len;
369
370 /*
371 * Parse header (code, id and length).
372 * If packet too short, drop it.
373 */
374 inp = inpacket;
375 if (packet_len < CHAP_HEADERLEN) {
376 CHAPDEBUG(LOG_INFO, ("ChapInput: rcvd short header.\n"));
377 return;
378 }
379 GETCHAR(code, inp);
380 GETCHAR(id, inp);
381 GETSHORT(len, inp);
382 if (len < CHAP_HEADERLEN) {
383 CHAPDEBUG(LOG_INFO, ("ChapInput: rcvd illegal length.\n"));
384 return;
385 }
386 if (len > packet_len) {
387 CHAPDEBUG(LOG_INFO, ("ChapInput: rcvd short packet.\n"));
388 return;
389 }
390 len -= CHAP_HEADERLEN;
391
392 /*
393 * Action depends on code (as in fact it usually does :-).
394 */
395 switch (code) {
396 case CHAP_CHALLENGE:
397 ChapReceiveChallenge(cstate, inp, id, len);
398 break;
399
400 case CHAP_RESPONSE:
401 ChapReceiveResponse(cstate, inp, id, len);
402 break;
403
404 case CHAP_FAILURE:
405 ChapReceiveFailure(cstate, inp, id, len);
406 break;
407
408 case CHAP_SUCCESS:
409 ChapReceiveSuccess(cstate, inp, id, len);
410 break;
411
412 default: /* Need code reject? */
413 CHAPDEBUG(LOG_WARNING, ("Unknown CHAP code (%d) received.\n", code));
414 break;
415 }
416 }
417
418
419 /*
420 * ChapReceiveChallenge - Receive Challenge and send Response.
421 */
422 static void
423 ChapReceiveChallenge(chap_state *cstate, u_char *inp, u_char id, int len)
424 {
425 int rchallenge_len;
426 u_char *rchallenge;
427 int secret_len;
428 char secret[MAXSECRETLEN];
429 char rhostname[256];
430 MD5_CTX mdContext;
431 u_char hash[MD5_SIGNATURE_SIZE];
432
433 CHAPDEBUG(LOG_INFO, ("ChapReceiveChallenge: Rcvd id %d.\n", id));
434 if (cstate->clientstate == CHAPCS_CLOSED ||
435 cstate->clientstate == CHAPCS_PENDING) {
436 CHAPDEBUG(LOG_INFO, ("ChapReceiveChallenge: in state %d\n",
437 cstate->clientstate));
438 return;
439 }
440
441 if (len < 2) {
442 CHAPDEBUG(LOG_INFO, ("ChapReceiveChallenge: rcvd short packet.\n"));
443 return;
444 }
445
446 GETCHAR(rchallenge_len, inp);
447 len -= sizeof (u_char) + rchallenge_len; /* now name field length */
448 if (len < 0) {
449 CHAPDEBUG(LOG_INFO, ("ChapReceiveChallenge: rcvd short packet.\n"));
450 return;
451 }
452 rchallenge = inp;
453 INCPTR(rchallenge_len, inp);
454
455 if (len >= (int)sizeof(rhostname)) {
456 len = sizeof(rhostname) - 1;
457 }
458 BCOPY(inp, rhostname, len);
459 rhostname[len] = '\000';
460
461 CHAPDEBUG(LOG_INFO, ("ChapReceiveChallenge: received name field '%s'\n",
462 rhostname));
463
464 /* Microsoft doesn't send their name back in the PPP packet */
465 if (ppp_settings.remote_name[0] != 0 && (ppp_settings.explicit_remote || rhostname[0] == 0)) {
466 strncpy(rhostname, ppp_settings.remote_name, sizeof(rhostname));
467 rhostname[sizeof(rhostname) - 1] = 0;
468 CHAPDEBUG(LOG_INFO, ("ChapReceiveChallenge: using '%s' as remote name\n",
469 rhostname));
470 }
471
472 /* get secret for authenticating ourselves with the specified host */
473 if (!get_secret(cstate->unit, cstate->resp_name, rhostname,
474 secret, &secret_len, 0)) {
475 secret_len = 0; /* assume null secret if can't find one */
476 CHAPDEBUG(LOG_WARNING, ("No CHAP secret found for authenticating us to %s\n",
477 rhostname));
478 }
479
480 /* cancel response send timeout if necessary */
481 if (cstate->clientstate == CHAPCS_RESPONSE) {
482 UNTIMEOUT(ChapResponseTimeout, cstate);
483 }
484
485 cstate->resp_id = id;
486 cstate->resp_transmits = 0;
487
488 /* generate MD based on negotiated type */
489 switch (cstate->resp_type) {
490
491 case CHAP_DIGEST_MD5:
492 MD5Init(&mdContext);
493 MD5Update(&mdContext, &cstate->resp_id, 1);
494 MD5Update(&mdContext, (u_char*)secret, secret_len);
495 MD5Update(&mdContext, rchallenge, rchallenge_len);
496 MD5Final(hash, &mdContext);
497 BCOPY(hash, cstate->response, MD5_SIGNATURE_SIZE);
498 cstate->resp_length = MD5_SIGNATURE_SIZE;
499 break;
500
501 #if MSCHAP_SUPPORT
502 case CHAP_MICROSOFT:
503 ChapMS(cstate, rchallenge, rchallenge_len, secret, secret_len);
504 break;
505 #endif
506
507 default:
508 CHAPDEBUG(LOG_INFO, ("unknown digest type %d\n", cstate->resp_type));
509 return;
510 }
511
512 BZERO(secret, sizeof(secret));
513 ChapSendResponse(cstate);
514 }
515
516
517 /*
518 * ChapReceiveResponse - Receive and process response.
519 */
520 static void
521 ChapReceiveResponse(chap_state *cstate, u_char *inp, int id, int len)
522 {
523 u_char *remmd, remmd_len;
524 int secret_len, old_state;
525 int code;
526 char rhostname[256];
527 MD5_CTX mdContext;
528 char secret[MAXSECRETLEN];
529 u_char hash[MD5_SIGNATURE_SIZE];
530
531 CHAPDEBUG(LOG_INFO, ("ChapReceiveResponse: Rcvd id %d.\n", id));
532
533 if (cstate->serverstate == CHAPSS_CLOSED ||
534 cstate->serverstate == CHAPSS_PENDING) {
535 CHAPDEBUG(LOG_INFO, ("ChapReceiveResponse: in state %d\n",
536 cstate->serverstate));
537 return;
538 }
539
540 if (id != cstate->chal_id) {
541 return; /* doesn't match ID of last challenge */
542 }
543
544 /*
545 * If we have received a duplicate or bogus Response,
546 * we have to send the same answer (Success/Failure)
547 * as we did for the first Response we saw.
548 */
549 if (cstate->serverstate == CHAPSS_OPEN) {
550 ChapSendStatus(cstate, CHAP_SUCCESS);
551 return;
552 }
553 if (cstate->serverstate == CHAPSS_BADAUTH) {
554 ChapSendStatus(cstate, CHAP_FAILURE);
555 return;
556 }
557
558 if (len < 2) {
559 CHAPDEBUG(LOG_INFO, ("ChapReceiveResponse: rcvd short packet.\n"));
560 return;
561 }
562 GETCHAR(remmd_len, inp); /* get length of MD */
563 remmd = inp; /* get pointer to MD */
564 INCPTR(remmd_len, inp);
565
566 len -= sizeof (u_char) + remmd_len;
567 if (len < 0) {
568 CHAPDEBUG(LOG_INFO, ("ChapReceiveResponse: rcvd short packet.\n"));
569 return;
570 }
571
572 UNTIMEOUT(ChapChallengeTimeout, cstate);
573
574 if (len >= (int)sizeof(rhostname)) {
575 len = sizeof(rhostname) - 1;
576 }
577 BCOPY(inp, rhostname, len);
578 rhostname[len] = '\000';
579
580 CHAPDEBUG(LOG_INFO, ("ChapReceiveResponse: received name field: %s\n",
581 rhostname));
582
583 /*
584 * Get secret for authenticating them with us,
585 * do the hash ourselves, and compare the result.
586 */
587 code = CHAP_FAILURE;
588 if (!get_secret(cstate->unit, rhostname, cstate->chal_name,
589 secret, &secret_len, 1)) {
590 CHAPDEBUG(LOG_WARNING, ("No CHAP secret found for authenticating %s\n",
591 rhostname));
592 } else {
593 /* generate MD based on negotiated type */
594 switch (cstate->chal_type) {
595
596 case CHAP_DIGEST_MD5: /* only MD5 is defined for now */
597 if (remmd_len != MD5_SIGNATURE_SIZE) {
598 break; /* it's not even the right length */
599 }
600 MD5Init(&mdContext);
601 MD5Update(&mdContext, &cstate->chal_id, 1);
602 MD5Update(&mdContext, (u_char*)secret, secret_len);
603 MD5Update(&mdContext, cstate->challenge, cstate->chal_len);
604 MD5Final(hash, &mdContext);
605
606 /* compare local and remote MDs and send the appropriate status */
607 if (memcmp (hash, remmd, MD5_SIGNATURE_SIZE) == 0) {
608 code = CHAP_SUCCESS; /* they are the same! */
609 }
610 break;
611
612 default:
613 CHAPDEBUG(LOG_INFO, ("unknown digest type %d\n", cstate->chal_type));
614 }
615 }
616
617 BZERO(secret, sizeof(secret));
618 ChapSendStatus(cstate, code);
619
620 if (code == CHAP_SUCCESS) {
621 old_state = cstate->serverstate;
622 cstate->serverstate = CHAPSS_OPEN;
623 if (old_state == CHAPSS_INITIAL_CHAL) {
624 auth_peer_success(cstate->unit, PPP_CHAP, rhostname, len);
625 }
626 if (cstate->chal_interval != 0) {
627 TIMEOUT(ChapRechallenge, cstate, cstate->chal_interval);
628 }
629 } else {
630 CHAPDEBUG(LOG_ERR, ("CHAP peer authentication failed\n"));
631 cstate->serverstate = CHAPSS_BADAUTH;
632 auth_peer_fail(cstate->unit, PPP_CHAP);
633 }
634 }
635
636 /*
637 * ChapReceiveSuccess - Receive Success
638 */
639 static void
640 ChapReceiveSuccess(chap_state *cstate, u_char *inp, u_char id, int len)
641 {
642 LWIP_UNUSED_ARG(id);
643 LWIP_UNUSED_ARG(inp);
644
645 CHAPDEBUG(LOG_INFO, ("ChapReceiveSuccess: Rcvd id %d.\n", id));
646
647 if (cstate->clientstate == CHAPCS_OPEN) {
648 /* presumably an answer to a duplicate response */
649 return;
650 }
651
652 if (cstate->clientstate != CHAPCS_RESPONSE) {
653 /* don't know what this is */
654 CHAPDEBUG(LOG_INFO, ("ChapReceiveSuccess: in state %d\n",
655 cstate->clientstate));
656 return;
657 }
658
659 UNTIMEOUT(ChapResponseTimeout, cstate);
660
661 /*
662 * Print message.
663 */
664 if (len > 0) {
665 PRINTMSG(inp, len);
666 }
667
668 cstate->clientstate = CHAPCS_OPEN;
669
670 auth_withpeer_success(cstate->unit, PPP_CHAP);
671 }
672
673
674 /*
675 * ChapReceiveFailure - Receive failure.
676 */
677 static void
678 ChapReceiveFailure(chap_state *cstate, u_char *inp, u_char id, int len)
679 {
680 LWIP_UNUSED_ARG(id);
681 LWIP_UNUSED_ARG(inp);
682
683 CHAPDEBUG(LOG_INFO, ("ChapReceiveFailure: Rcvd id %d.\n", id));
684
685 if (cstate->clientstate != CHAPCS_RESPONSE) {
686 /* don't know what this is */
687 CHAPDEBUG(LOG_INFO, ("ChapReceiveFailure: in state %d\n",
688 cstate->clientstate));
689 return;
690 }
691
692 UNTIMEOUT(ChapResponseTimeout, cstate);
693
694 /*
695 * Print message.
696 */
697 if (len > 0) {
698 PRINTMSG(inp, len);
699 }
700
701 CHAPDEBUG(LOG_ERR, ("CHAP authentication failed\n"));
702 auth_withpeer_fail(cstate->unit, PPP_CHAP); /* lwip: just sets the PPP error code on this unit to PPPERR_AUTHFAIL */
703 }
704
705
706 /*
707 * ChapSendChallenge - Send an Authenticate challenge.
708 */
709 static void
710 ChapSendChallenge(chap_state *cstate)
711 {
712 u_char *outp;
713 int chal_len, name_len;
714 int outlen;
715
716 chal_len = cstate->chal_len;
717 name_len = (int)strlen(cstate->chal_name);
718 outlen = CHAP_HEADERLEN + sizeof (u_char) + chal_len + name_len;
719 outp = outpacket_buf[cstate->unit];
720
721 MAKEHEADER(outp, PPP_CHAP); /* paste in a CHAP header */
722
723 PUTCHAR(CHAP_CHALLENGE, outp);
724 PUTCHAR(cstate->chal_id, outp);
725 PUTSHORT(outlen, outp);
726
727 PUTCHAR(chal_len, outp); /* put length of challenge */
728 BCOPY(cstate->challenge, outp, chal_len);
729 INCPTR(chal_len, outp);
730
731 BCOPY(cstate->chal_name, outp, name_len); /* append hostname */
732
733 pppWrite(cstate->unit, outpacket_buf[cstate->unit], outlen + PPP_HDRLEN);
734
735 CHAPDEBUG(LOG_INFO, ("ChapSendChallenge: Sent id %d.\n", cstate->chal_id));
736
737 TIMEOUT(ChapChallengeTimeout, cstate, cstate->timeouttime);
738 ++cstate->chal_transmits;
739 }
740
741
742 /*
743 * ChapSendStatus - Send a status response (ack or nak).
744 */
745 static void
746 ChapSendStatus(chap_state *cstate, int code)
747 {
748 u_char *outp;
749 int outlen, msglen;
750 char msg[256]; /* @todo: this can be a char*, no strcpy needed */
751
752 if (code == CHAP_SUCCESS) {
753 strcpy(msg, "Welcome!");
754 } else {
755 strcpy(msg, "I don't like you. Go 'way.");
756 }
757 msglen = (int)strlen(msg);
758
759 outlen = CHAP_HEADERLEN + msglen;
760 outp = outpacket_buf[cstate->unit];
761
762 MAKEHEADER(outp, PPP_CHAP); /* paste in a header */
763
764 PUTCHAR(code, outp);
765 PUTCHAR(cstate->chal_id, outp);
766 PUTSHORT(outlen, outp);
767 BCOPY(msg, outp, msglen);
768 pppWrite(cstate->unit, outpacket_buf[cstate->unit], outlen + PPP_HDRLEN);
769
770 CHAPDEBUG(LOG_INFO, ("ChapSendStatus: Sent code %d, id %d.\n", code,
771 cstate->chal_id));
772 }
773
774 /*
775 * ChapGenChallenge is used to generate a pseudo-random challenge string of
776 * a pseudo-random length between min_len and max_len. The challenge
777 * string and its length are stored in *cstate, and various other fields of
778 * *cstate are initialized.
779 */
780
781 static void
782 ChapGenChallenge(chap_state *cstate)
783 {
784 int chal_len;
785 u_char *ptr = cstate->challenge;
786 int i;
787
788 /* pick a random challenge length between MIN_CHALLENGE_LENGTH and
789 MAX_CHALLENGE_LENGTH */
790 chal_len = (unsigned)
791 ((((magic() >> 16) *
792 (MAX_CHALLENGE_LENGTH - MIN_CHALLENGE_LENGTH)) >> 16)
793 + MIN_CHALLENGE_LENGTH);
794 LWIP_ASSERT("chal_len <= 0xff", chal_len <= 0xffff);
795 cstate->chal_len = (u_char)chal_len;
796 cstate->chal_id = ++cstate->id;
797 cstate->chal_transmits = 0;
798
799 /* generate a random string */
800 for (i = 0; i < chal_len; i++ ) {
801 *ptr++ = (char) (magic() & 0xff);
802 }
803 }
804
805 /*
806 * ChapSendResponse - send a response packet with values as specified
807 * in *cstate.
808 */
809 /* ARGSUSED */
810 static void
811 ChapSendResponse(chap_state *cstate)
812 {
813 u_char *outp;
814 int outlen, md_len, name_len;
815
816 md_len = cstate->resp_length;
817 name_len = (int)strlen(cstate->resp_name);
818 outlen = CHAP_HEADERLEN + sizeof (u_char) + md_len + name_len;
819 outp = outpacket_buf[cstate->unit];
820
821 MAKEHEADER(outp, PPP_CHAP);
822
823 PUTCHAR(CHAP_RESPONSE, outp); /* we are a response */
824 PUTCHAR(cstate->resp_id, outp); /* copy id from challenge packet */
825 PUTSHORT(outlen, outp); /* packet length */
826
827 PUTCHAR(md_len, outp); /* length of MD */
828 BCOPY(cstate->response, outp, md_len); /* copy MD to buffer */
829 INCPTR(md_len, outp);
830
831 BCOPY(cstate->resp_name, outp, name_len); /* append our name */
832
833 /* send the packet */
834 pppWrite(cstate->unit, outpacket_buf[cstate->unit], outlen + PPP_HDRLEN);
835
836 cstate->clientstate = CHAPCS_RESPONSE;
837 TIMEOUT(ChapResponseTimeout, cstate, cstate->timeouttime);
838 ++cstate->resp_transmits;
839 }
840
841 #if PPP_ADDITIONAL_CALLBACKS
842 static char *ChapCodenames[] = {
843 "Challenge", "Response", "Success", "Failure"
844 };
845 /*
846 * ChapPrintPkt - print the contents of a CHAP packet.
847 */
848 static int
849 ChapPrintPkt( u_char *p, int plen, void (*printer) (void *, char *, ...), void *arg)
850 {
851 int code, id, len;
852 int clen, nlen;
853 u_char x;
854
855 if (plen < CHAP_HEADERLEN) {
856 return 0;
857 }
858 GETCHAR(code, p);
859 GETCHAR(id, p);
860 GETSHORT(len, p);
861 if (len < CHAP_HEADERLEN || len > plen) {
862 return 0;
863 }
864
865 if (code >= 1 && code <= sizeof(ChapCodenames) / sizeof(char *)) {
866 printer(arg, " %s", ChapCodenames[code-1]);
867 } else {
868 printer(arg, " code=0x%x", code);
869 }
870 printer(arg, " id=0x%x", id);
871 len -= CHAP_HEADERLEN;
872 switch (code) {
873 case CHAP_CHALLENGE:
874 case CHAP_RESPONSE:
875 if (len < 1) {
876 break;
877 }
878 clen = p[0];
879 if (len < clen + 1) {
880 break;
881 }
882 ++p;
883 nlen = len - clen - 1;
884 printer(arg, " <");
885 for (; clen > 0; --clen) {
886 GETCHAR(x, p);
887 printer(arg, "%.2x", x);
888 }
889 printer(arg, ">, name = %.*Z", nlen, p);
890 break;
891 case CHAP_FAILURE:
892 case CHAP_SUCCESS:
893 printer(arg, " %.*Z", len, p);
894 break;
895 default:
896 for (clen = len; clen > 0; --clen) {
897 GETCHAR(x, p);
898 printer(arg, " %.2x", x);
899 }
900 }
901
902 return len + CHAP_HEADERLEN;
903 }
904 #endif /* PPP_ADDITIONAL_CALLBACKS */
905
906 #endif /* CHAP_SUPPORT */
907
908 #endif /* PPP_SUPPORT */