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[/] [openrisc/] [trunk/] [rtos/] [rtems/] [c/] [src/] [libnetworking/] [pppd/] [chap.c] - Blame information for rev 30

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/*
2
 * chap.c - Challenge Handshake Authentication Protocol.
3
 *
4
 * Copyright (c) 1993 The Australian National University.
5
 * All rights reserved.
6
 *
7
 * Redistribution and use in source and binary forms are permitted
8
 * provided that the above copyright notice and this paragraph are
9
 * duplicated in all such forms and that any documentation,
10
 * advertising materials, and other materials related to such
11
 * distribution and use acknowledge that the software was developed
12
 * by the Australian National University.  The name of the University
13
 * may not be used to endorse or promote products derived from this
14
 * software without specific prior written permission.
15
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
16
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
17
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
18
 *
19
 * Copyright (c) 1991 Gregory M. Christy.
20
 * All rights reserved.
21
 *
22
 * Redistribution and use in source and binary forms are permitted
23
 * provided that the above copyright notice and this paragraph are
24
 * duplicated in all such forms and that any documentation,
25
 * advertising materials, and other materials related to such
26
 * distribution and use acknowledge that the software was developed
27
 * by Gregory M. Christy.  The name of the author may not be used to
28
 * endorse or promote products derived from this software without
29
 * specific prior written permission.
30
 *
31
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
32
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
33
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
34
 */
35
 
36
#ifndef lint
37
/* static char rcsid[] = "$Id: chap.c,v 1.2 2001-09-27 12:01:57 chris Exp $"; */
38
#endif
39
 
40
/*
41
 * TODO:
42
 */
43
 
44
#include <stdio.h>
45
#include <string.h>
46
#include <sys/types.h>
47
#include <sys/time.h>
48
#include <syslog.h>
49
 
50
#include "pppd.h"
51
#include "chap.h"
52
#include "md5.h"
53
#ifdef CHAPMS
54
#include "chap_ms.h"
55
#endif
56
 
57
/*
58
 * Protocol entry points.
59
 */
60
static void ChapInit __P((int));
61
static void ChapLowerUp __P((int));
62
static void ChapLowerDown __P((int));
63
static void ChapInput __P((int, u_char *, int));
64
static void ChapProtocolReject __P((int));
65
static int  ChapPrintPkt __P((u_char *, int,
66
                              void (*) __P((void *, char *, ...)), void *));
67
 
68
struct protent chap_protent = {
69
    PPP_CHAP,
70
    ChapInit,
71
    ChapInput,
72
    ChapProtocolReject,
73
    ChapLowerUp,
74
    ChapLowerDown,
75
    NULL,
76
    NULL,
77
    ChapPrintPkt,
78
    NULL,
79
    1,
80
    "CHAP",
81
    NULL,
82
    NULL,
83
    NULL
84
};
85
 
86
chap_state chap[NUM_PPP];               /* CHAP state; one for each unit */
87
 
88
static void ChapChallengeTimeout __P((void *));
89
static void ChapResponseTimeout __P((void *));
90
static void ChapReceiveChallenge __P((chap_state *, u_char *, int, int));
91
static void ChapRechallenge __P((void *));
92
static void ChapReceiveResponse __P((chap_state *, u_char *, int, int));
93
static void ChapReceiveSuccess __P((chap_state *, u_char *, int, int));
94
static void ChapReceiveFailure __P((chap_state *, u_char *, int, int));
95
static void ChapSendStatus __P((chap_state *, int));
96
static void ChapSendChallenge __P((chap_state *));
97
static void ChapSendResponse __P((chap_state *));
98
static void ChapGenChallenge __P((chap_state *));
99
/* #include <stdlib.h> */
100
 
101
extern double drand48 __P((void));
102
/*{
103
        return (((double)rand())/RAND_MAX);
104
}
105
*/
106
extern void srand48 __P((long));
107
 
108
/*
109
 * ChapInit - Initialize a CHAP unit.
110
 */
111
static void
112
ChapInit(unit)
113
    int unit;
114
{
115
    chap_state *cstate = &chap[unit];
116
 
117
    BZERO(cstate, sizeof(*cstate));
118
    cstate->unit = unit;
119
    cstate->clientstate = CHAPCS_INITIAL;
120
    cstate->serverstate = CHAPSS_INITIAL;
121
    cstate->timeouttime = CHAP_DEFTIMEOUT;
122
    cstate->max_transmits = CHAP_DEFTRANSMITS;
123
    /* random number generator is initialized in magic_init */
124
}
125
 
126
 
127
/*
128
 * ChapAuthWithPeer - Authenticate us with our peer (start client).
129
 *
130
 */
131
void
132
ChapAuthWithPeer(unit, our_name, digest)
133
    int unit;
134
    char *our_name;
135
    int digest;
136
{
137
    chap_state *cstate = &chap[unit];
138
 
139
    cstate->resp_name = our_name;
140
    cstate->resp_type = digest;
141
 
142
    if (cstate->clientstate == CHAPCS_INITIAL ||
143
        cstate->clientstate == CHAPCS_PENDING) {
144
        /* lower layer isn't up - wait until later */
145
        cstate->clientstate = CHAPCS_PENDING;
146
        return;
147
    }
148
 
149
    /*
150
     * We get here as a result of LCP coming up.
151
     * So even if CHAP was open before, we will
152
     * have to re-authenticate ourselves.
153
     */
154
    cstate->clientstate = CHAPCS_LISTEN;
155
}
156
 
157
 
158
/*
159
 * ChapAuthPeer - Authenticate our peer (start server).
160
 */
161
void
162
ChapAuthPeer(unit, our_name, digest)
163
    int unit;
164
    char *our_name;
165
    int digest;
166
{
167
    chap_state *cstate = &chap[unit];
168
 
169
    cstate->chal_name = our_name;
170
    cstate->chal_type = digest;
171
 
172
    if (cstate->serverstate == CHAPSS_INITIAL ||
173
        cstate->serverstate == CHAPSS_PENDING) {
174
        /* lower layer isn't up - wait until later */
175
        cstate->serverstate = CHAPSS_PENDING;
176
        return;
177
    }
178
 
179
    ChapGenChallenge(cstate);
180
    ChapSendChallenge(cstate);          /* crank it up dude! */
181
    cstate->serverstate = CHAPSS_INITIAL_CHAL;
182
}
183
 
184
 
185
/*
186
 * ChapChallengeTimeout - Timeout expired on sending challenge.
187
 */
188
static void
189
ChapChallengeTimeout(arg)
190
    void *arg;
191
{
192
    chap_state *cstate = (chap_state *) arg;
193
 
194
    /* if we aren't sending challenges, don't worry.  then again we */
195
    /* probably shouldn't be here either */
196
    if (cstate->serverstate != CHAPSS_INITIAL_CHAL &&
197
        cstate->serverstate != CHAPSS_RECHALLENGE)
198
        return;
199
 
200
    if (cstate->chal_transmits >= cstate->max_transmits) {
201
        /* give up on peer */
202
        syslog(LOG_ERR, "Peer failed to respond to CHAP challenge");
203
        cstate->serverstate = CHAPSS_BADAUTH;
204
        auth_peer_fail(cstate->unit, PPP_CHAP);
205
        return;
206
    }
207
 
208
    ChapSendChallenge(cstate);          /* Re-send challenge */
209
}
210
 
211
 
212
/*
213
 * ChapResponseTimeout - Timeout expired on sending response.
214
 */
215
static void
216
ChapResponseTimeout(arg)
217
    void *arg;
218
{
219
    chap_state *cstate = (chap_state *) arg;
220
 
221
    /* if we aren't sending a response, don't worry. */
222
    if (cstate->clientstate != CHAPCS_RESPONSE)
223
        return;
224
 
225
    ChapSendResponse(cstate);           /* re-send response */
226
}
227
 
228
 
229
/*
230
 * ChapRechallenge - Time to challenge the peer again.
231
 */
232
static void
233
ChapRechallenge(arg)
234
    void *arg;
235
{
236
    chap_state *cstate = (chap_state *) arg;
237
 
238
    /* if we aren't sending a response, don't worry. */
239
    if (cstate->serverstate != CHAPSS_OPEN)
240
        return;
241
 
242
    ChapGenChallenge(cstate);
243
    ChapSendChallenge(cstate);
244
    cstate->serverstate = CHAPSS_RECHALLENGE;
245
}
246
 
247
 
248
/*
249
 * ChapLowerUp - The lower layer is up.
250
 *
251
 * Start up if we have pending requests.
252
 */
253
static void
254
ChapLowerUp(unit)
255
    int unit;
256
{
257
    chap_state *cstate = &chap[unit];
258
 
259
    if (cstate->clientstate == CHAPCS_INITIAL)
260
        cstate->clientstate = CHAPCS_CLOSED;
261
    else if (cstate->clientstate == CHAPCS_PENDING)
262
        cstate->clientstate = CHAPCS_LISTEN;
263
 
264
    if (cstate->serverstate == CHAPSS_INITIAL)
265
        cstate->serverstate = CHAPSS_CLOSED;
266
    else if (cstate->serverstate == CHAPSS_PENDING) {
267
        ChapGenChallenge(cstate);
268
        ChapSendChallenge(cstate);
269
        cstate->serverstate = CHAPSS_INITIAL_CHAL;
270
    }
271
}
272
 
273
 
274
/*
275
 * ChapLowerDown - The lower layer is down.
276
 *
277
 * Cancel all timeouts.
278
 */
279
static void
280
ChapLowerDown(unit)
281
    int unit;
282
{
283
    chap_state *cstate = &chap[unit];
284
 
285
    /* Timeout(s) pending?  Cancel if so. */
286
    if (cstate->serverstate == CHAPSS_INITIAL_CHAL ||
287
        cstate->serverstate == CHAPSS_RECHALLENGE)
288
        UNTIMEOUT(ChapChallengeTimeout, cstate);
289
    else if (cstate->serverstate == CHAPSS_OPEN
290
             && cstate->chal_interval != 0)
291
        UNTIMEOUT(ChapRechallenge, cstate);
292
    if (cstate->clientstate == CHAPCS_RESPONSE)
293
        UNTIMEOUT(ChapResponseTimeout, cstate);
294
 
295
    cstate->clientstate = CHAPCS_INITIAL;
296
    cstate->serverstate = CHAPSS_INITIAL;
297
}
298
 
299
 
300
/*
301
 * ChapProtocolReject - Peer doesn't grok CHAP.
302
 */
303
static void
304
ChapProtocolReject(unit)
305
    int unit;
306
{
307
    chap_state *cstate = &chap[unit];
308
 
309
    if (cstate->serverstate != CHAPSS_INITIAL &&
310
        cstate->serverstate != CHAPSS_CLOSED)
311
        auth_peer_fail(unit, PPP_CHAP);
312
    if (cstate->clientstate != CHAPCS_INITIAL &&
313
        cstate->clientstate != CHAPCS_CLOSED)
314
        auth_withpeer_fail(unit, PPP_CHAP);
315
    ChapLowerDown(unit);                /* shutdown chap */
316
}
317
 
318
 
319
/*
320
 * ChapInput - Input CHAP packet.
321
 */
322
static void
323
ChapInput(unit, inpacket, packet_len)
324
    int unit;
325
    u_char *inpacket;
326
    int packet_len;
327
{
328
    chap_state *cstate = &chap[unit];
329
    u_char *inp;
330
    u_char code, id;
331
    int len;
332
 
333
    /*
334
     * Parse header (code, id and length).
335
     * If packet too short, drop it.
336
     */
337
    inp = inpacket;
338
    if (packet_len < CHAP_HEADERLEN) {
339
        CHAPDEBUG((LOG_INFO, "ChapInput: rcvd short header."));
340
        return;
341
    }
342
    GETCHAR(code, inp);
343
    GETCHAR(id, inp);
344
    GETSHORT(len, inp);
345
    if (len < CHAP_HEADERLEN) {
346
        CHAPDEBUG((LOG_INFO, "ChapInput: rcvd illegal length."));
347
        return;
348
    }
349
    if (len > packet_len) {
350
        CHAPDEBUG((LOG_INFO, "ChapInput: rcvd short packet."));
351
        return;
352
    }
353
    len -= CHAP_HEADERLEN;
354
 
355
    /*
356
     * Action depends on code (as in fact it usually does :-).
357
     */
358
    switch (code) {
359
    case CHAP_CHALLENGE:
360
        ChapReceiveChallenge(cstate, inp, id, len);
361
        break;
362
 
363
    case CHAP_RESPONSE:
364
        ChapReceiveResponse(cstate, inp, id, len);
365
        break;
366
 
367
    case CHAP_FAILURE:
368
        ChapReceiveFailure(cstate, inp, id, len);
369
        break;
370
 
371
    case CHAP_SUCCESS:
372
        ChapReceiveSuccess(cstate, inp, id, len);
373
        break;
374
 
375
    default:                            /* Need code reject? */
376
        syslog(LOG_WARNING, "Unknown CHAP code (%d) received.", code);
377
        break;
378
    }
379
}
380
 
381
 
382
/*
383
 * ChapReceiveChallenge - Receive Challenge and send Response.
384
 */
385
static void
386
ChapReceiveChallenge(cstate, inp, id, len)
387
    chap_state *cstate;
388
    u_char *inp;
389
    int id;
390
    int len;
391
{
392
    int rchallenge_len;
393
    u_char *rchallenge;
394
    int secret_len;
395
    char secret[MAXSECRETLEN];
396
    char rhostname[256];
397
    MD5_CTX mdContext;
398
    u_char hash[MD5_SIGNATURE_SIZE];
399
 
400
    CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: Rcvd id %d.", id));
401
    if (cstate->clientstate == CHAPCS_CLOSED ||
402
        cstate->clientstate == CHAPCS_PENDING) {
403
        CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: in state %d",
404
                   cstate->clientstate));
405
        return;
406
    }
407
 
408
    if (len < 2) {
409
        CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: rcvd short packet."));
410
        return;
411
    }
412
 
413
    GETCHAR(rchallenge_len, inp);
414
    len -= sizeof (u_char) + rchallenge_len;    /* now name field length */
415
    if (len < 0) {
416
        CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: rcvd short packet."));
417
        return;
418
    }
419
    rchallenge = inp;
420
    INCPTR(rchallenge_len, inp);
421
 
422
    if (len >= sizeof(rhostname))
423
        len = sizeof(rhostname) - 1;
424
    BCOPY(inp, rhostname, len);
425
    rhostname[len] = '\000';
426
 
427
    CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: received name field '%s'",
428
               rhostname));
429
 
430
    /* Microsoft doesn't send their name back in the PPP packet */
431
    if (remote_name[0] != 0 && (explicit_remote || rhostname[0] == 0)) {
432
        strncpy(rhostname, remote_name, sizeof(rhostname));
433
        rhostname[sizeof(rhostname) - 1] = 0;
434
        CHAPDEBUG((LOG_INFO, "ChapReceiveChallenge: using '%s' as remote name",
435
                   rhostname));
436
    }
437
 
438
    /* get secret for authenticating ourselves with the specified host */
439
    if (!get_secret(cstate->unit, cstate->resp_name, rhostname,
440
                    secret, &secret_len, 0)) {
441
        secret_len = 0;          /* assume null secret if can't find one */
442
        syslog(LOG_WARNING, "No CHAP secret found for authenticating us to %s",
443
               rhostname);
444
    }
445
 
446
    /* cancel response send timeout if necessary */
447
    if (cstate->clientstate == CHAPCS_RESPONSE)
448
        UNTIMEOUT(ChapResponseTimeout, cstate);
449
 
450
    cstate->resp_id = id;
451
    cstate->resp_transmits = 0;
452
 
453
    /*  generate MD based on negotiated type */
454
    switch (cstate->resp_type) {
455
 
456
    case CHAP_DIGEST_MD5:
457
        MD5Init(&mdContext);
458
        MD5Update(&mdContext, &cstate->resp_id, 1);
459
        MD5Update(&mdContext, secret, secret_len);
460
        MD5Update(&mdContext, rchallenge, rchallenge_len);
461
        MD5Final(hash, &mdContext);
462
        BCOPY(hash, cstate->response, MD5_SIGNATURE_SIZE);
463
        cstate->resp_length = MD5_SIGNATURE_SIZE;
464
        break;
465
 
466
#ifdef CHAPMS
467
    case CHAP_MICROSOFT:
468
        ChapMS(cstate, rchallenge, rchallenge_len, secret, secret_len);
469
        break;
470
#endif
471
 
472
    default:
473
        CHAPDEBUG((LOG_INFO, "unknown digest type %d", cstate->resp_type));
474
        return;
475
    }
476
 
477
    BZERO(secret, sizeof(secret));
478
    ChapSendResponse(cstate);
479
}
480
 
481
 
482
/*
483
 * ChapReceiveResponse - Receive and process response.
484
 */
485
static void
486
ChapReceiveResponse(cstate, inp, id, len)
487
    chap_state *cstate;
488
    u_char *inp;
489
    int id;
490
    int len;
491
{
492
    u_char *remmd, remmd_len;
493
    int secret_len, old_state;
494
    int code;
495
    char rhostname[256];
496
    MD5_CTX mdContext;
497
    char secret[MAXSECRETLEN];
498
    u_char hash[MD5_SIGNATURE_SIZE];
499
 
500
    CHAPDEBUG((LOG_INFO, "ChapReceiveResponse: Rcvd id %d.", id));
501
 
502
    if (cstate->serverstate == CHAPSS_CLOSED ||
503
        cstate->serverstate == CHAPSS_PENDING) {
504
        CHAPDEBUG((LOG_INFO, "ChapReceiveResponse: in state %d",
505
                   cstate->serverstate));
506
        return;
507
    }
508
 
509
    if (id != cstate->chal_id)
510
        return;                 /* doesn't match ID of last challenge */
511
 
512
    /*
513
     * If we have received a duplicate or bogus Response,
514
     * we have to send the same answer (Success/Failure)
515
     * as we did for the first Response we saw.
516
     */
517
    if (cstate->serverstate == CHAPSS_OPEN) {
518
        ChapSendStatus(cstate, CHAP_SUCCESS);
519
        return;
520
    }
521
    if (cstate->serverstate == CHAPSS_BADAUTH) {
522
        ChapSendStatus(cstate, CHAP_FAILURE);
523
        return;
524
    }
525
 
526
    if (len < 2) {
527
        CHAPDEBUG((LOG_INFO, "ChapReceiveResponse: rcvd short packet."));
528
        return;
529
    }
530
    GETCHAR(remmd_len, inp);            /* get length of MD */
531
    remmd = inp;                        /* get pointer to MD */
532
    INCPTR(remmd_len, inp);
533
 
534
    len -= sizeof (u_char) + remmd_len;
535
    if (len < 0) {
536
        CHAPDEBUG((LOG_INFO, "ChapReceiveResponse: rcvd short packet."));
537
        return;
538
    }
539
 
540
    UNTIMEOUT(ChapChallengeTimeout, cstate);
541
 
542
    if (len >= sizeof(rhostname))
543
        len = sizeof(rhostname) - 1;
544
    BCOPY(inp, rhostname, len);
545
    rhostname[len] = '\000';
546
 
547
    CHAPDEBUG((LOG_INFO, "ChapReceiveResponse: received name field: %s",
548
               rhostname));
549
 
550
    /*
551
     * Get secret for authenticating them with us,
552
     * do the hash ourselves, and compare the result.
553
     */
554
    code = CHAP_FAILURE;
555
    if (!get_secret(cstate->unit, rhostname, cstate->chal_name,
556
                   secret, &secret_len, 1)) {
557
        syslog(LOG_WARNING, "No CHAP secret found for authenticating %s",
558
               rhostname);
559
    } else {
560
 
561
        /*  generate MD based on negotiated type */
562
        switch (cstate->chal_type) {
563
 
564
        case CHAP_DIGEST_MD5:           /* only MD5 is defined for now */
565
            if (remmd_len != MD5_SIGNATURE_SIZE)
566
                break;                  /* it's not even the right length */
567
            MD5Init(&mdContext);
568
            MD5Update(&mdContext, &cstate->chal_id, 1);
569
            MD5Update(&mdContext, secret, secret_len);
570
            MD5Update(&mdContext, cstate->challenge, cstate->chal_len);
571
            MD5Final(hash, &mdContext);
572
 
573
            /* compare local and remote MDs and send the appropriate status */
574
            if (memcmp (hash, remmd, MD5_SIGNATURE_SIZE) == 0)
575
                code = CHAP_SUCCESS;    /* they are the same! */
576
            break;
577
 
578
        default:
579
            CHAPDEBUG((LOG_INFO, "unknown digest type %d", cstate->chal_type));
580
        }
581
    }
582
 
583
    BZERO(secret, sizeof(secret));
584
    ChapSendStatus(cstate, code);
585
 
586
    if (code == CHAP_SUCCESS) {
587
        old_state = cstate->serverstate;
588
        cstate->serverstate = CHAPSS_OPEN;
589
        if (old_state == CHAPSS_INITIAL_CHAL) {
590
            auth_peer_success(cstate->unit, PPP_CHAP, rhostname, len);
591
        }
592
        if (cstate->chal_interval != 0)
593
            TIMEOUT(ChapRechallenge, cstate, cstate->chal_interval);
594
        syslog(LOG_NOTICE, "CHAP peer authentication succeeded for %s",
595
               rhostname);
596
 
597
    } else {
598
        syslog(LOG_ERR, "CHAP peer authentication failed for remote host %s",
599
               rhostname);
600
        cstate->serverstate = CHAPSS_BADAUTH;
601
        auth_peer_fail(cstate->unit, PPP_CHAP);
602
    }
603
}
604
 
605
/*
606
 * ChapReceiveSuccess - Receive Success
607
 */
608
static void
609
ChapReceiveSuccess(cstate, inp, id, len)
610
    chap_state *cstate;
611
    u_char *inp;
612
    int id;  /* was u_char id */
613
    int len;
614
{
615
 
616
    CHAPDEBUG((LOG_INFO, "ChapReceiveSuccess: Rcvd id %d.", id));
617
 
618
    if (cstate->clientstate == CHAPCS_OPEN)
619
        /* presumably an answer to a duplicate response */
620
        return;
621
 
622
    if (cstate->clientstate != CHAPCS_RESPONSE) {
623
        /* don't know what this is */
624
        CHAPDEBUG((LOG_INFO, "ChapReceiveSuccess: in state %d\n",
625
                   cstate->clientstate));
626
        return;
627
    }
628
 
629
    UNTIMEOUT(ChapResponseTimeout, cstate);
630
 
631
    /*
632
     * Print message.
633
     */
634
    if (len > 0)
635
        PRINTMSG(inp, len);
636
 
637
    cstate->clientstate = CHAPCS_OPEN;
638
 
639
    auth_withpeer_success(cstate->unit, PPP_CHAP);
640
}
641
 
642
 
643
/*
644
 * ChapReceiveFailure - Receive failure.
645
 */
646
static void
647
ChapReceiveFailure(cstate, inp, id, len)
648
    chap_state *cstate;
649
    u_char *inp;
650
    int id;  /* was u_char id; */
651
    int len;
652
{
653
    CHAPDEBUG((LOG_INFO, "ChapReceiveFailure: Rcvd id %d.", id));
654
 
655
    if (cstate->clientstate != CHAPCS_RESPONSE) {
656
        /* don't know what this is */
657
        CHAPDEBUG((LOG_INFO, "ChapReceiveFailure: in state %d\n",
658
                   cstate->clientstate));
659
        return;
660
    }
661
 
662
    UNTIMEOUT(ChapResponseTimeout, cstate);
663
 
664
    /*
665
     * Print message.
666
     */
667
    if (len > 0)
668
        PRINTMSG(inp, len);
669
 
670
    syslog(LOG_ERR, "CHAP authentication failed");
671
    auth_withpeer_fail(cstate->unit, PPP_CHAP);
672
}
673
 
674
 
675
/*
676
 * ChapSendChallenge - Send an Authenticate challenge.
677
 */
678
static void
679
ChapSendChallenge(cstate)
680
    chap_state *cstate;
681
{
682
    u_char *outp;
683
    int chal_len, name_len;
684
    int outlen;
685
 
686
    chal_len = cstate->chal_len;
687
    name_len = strlen(cstate->chal_name);
688
    outlen = CHAP_HEADERLEN + sizeof (u_char) + chal_len + name_len;
689
    outp = outpacket_buf;
690
 
691
    MAKEHEADER(outp, PPP_CHAP);         /* paste in a CHAP header */
692
 
693
    PUTCHAR(CHAP_CHALLENGE, outp);
694
    PUTCHAR(cstate->chal_id, outp);
695
    PUTSHORT(outlen, outp);
696
 
697
    PUTCHAR(chal_len, outp);            /* put length of challenge */
698
    BCOPY(cstate->challenge, outp, chal_len);
699
    INCPTR(chal_len, outp);
700
 
701
    BCOPY(cstate->chal_name, outp, name_len);   /* append hostname */
702
 
703
    output(cstate->unit, outpacket_buf, outlen + PPP_HDRLEN);
704
 
705
    CHAPDEBUG((LOG_INFO, "ChapSendChallenge: Sent id %d.", cstate->chal_id));
706
 
707
    TIMEOUT(ChapChallengeTimeout, cstate, cstate->timeouttime);
708
    ++cstate->chal_transmits;
709
}
710
 
711
 
712
/*
713
 * ChapSendStatus - Send a status response (ack or nak).
714
 */
715
static void
716
ChapSendStatus(cstate, code)
717
    chap_state *cstate;
718
    int code;
719
{
720
    u_char *outp;
721
    int outlen, msglen;
722
    char msg[256];
723
 
724
    if (code == CHAP_SUCCESS)
725
        sprintf(msg, "Welcome to %s.", hostname);
726
    else
727
        sprintf(msg, "I don't like you.  Go 'way.");
728
    msglen = strlen(msg);
729
 
730
    outlen = CHAP_HEADERLEN + msglen;
731
    outp = outpacket_buf;
732
 
733
    MAKEHEADER(outp, PPP_CHAP); /* paste in a header */
734
 
735
    PUTCHAR(code, outp);
736
    PUTCHAR(cstate->chal_id, outp);
737
    PUTSHORT(outlen, outp);
738
    BCOPY(msg, outp, msglen);
739
    output(cstate->unit, outpacket_buf, outlen + PPP_HDRLEN);
740
 
741
    CHAPDEBUG((LOG_INFO, "ChapSendStatus: Sent code %d, id %d.", code,
742
               cstate->chal_id));
743
}
744
 
745
/*
746
 * ChapGenChallenge is used to generate a pseudo-random challenge string of
747
 * a pseudo-random length between min_len and max_len.  The challenge
748
 * string and its length are stored in *cstate, and various other fields of
749
 * *cstate are initialized.
750
 */
751
 
752
static void
753
ChapGenChallenge(cstate)
754
    chap_state *cstate;
755
{
756
    int chal_len;
757
    u_char *ptr = cstate->challenge;
758
    unsigned int i;
759
 
760
    /* pick a random challenge length between MIN_CHALLENGE_LENGTH and
761
       MAX_CHALLENGE_LENGTH */
762
    chal_len =  (unsigned) ((drand48() *
763
                             (MAX_CHALLENGE_LENGTH - MIN_CHALLENGE_LENGTH)) +
764
                            MIN_CHALLENGE_LENGTH);
765
    cstate->chal_len = chal_len;
766
    cstate->chal_id = ++cstate->id;
767
    cstate->chal_transmits = 0;
768
 
769
    /* generate a random string */
770
    for (i = 0; i < chal_len; i++ )
771
        *ptr++ = (char) (drand48() * 0xff);
772
}
773
 
774
/*
775
 * ChapSendResponse - send a response packet with values as specified
776
 * in *cstate.
777
 */
778
/* ARGSUSED */
779
static void
780
ChapSendResponse(cstate)
781
    chap_state *cstate;
782
{
783
    u_char *outp;
784
    int outlen, md_len, name_len;
785
 
786
    md_len = cstate->resp_length;
787
    name_len = strlen(cstate->resp_name);
788
    outlen = CHAP_HEADERLEN + sizeof (u_char) + md_len + name_len;
789
    outp = outpacket_buf;
790
 
791
    MAKEHEADER(outp, PPP_CHAP);
792
 
793
    PUTCHAR(CHAP_RESPONSE, outp);       /* we are a response */
794
    PUTCHAR(cstate->resp_id, outp);     /* copy id from challenge packet */
795
    PUTSHORT(outlen, outp);             /* packet length */
796
 
797
    PUTCHAR(md_len, outp);              /* length of MD */
798
    BCOPY(cstate->response, outp, md_len);      /* copy MD to buffer */
799
    INCPTR(md_len, outp);
800
 
801
    BCOPY(cstate->resp_name, outp, name_len); /* append our name */
802
 
803
    /* send the packet */
804
    output(cstate->unit, outpacket_buf, outlen + PPP_HDRLEN);
805
 
806
    cstate->clientstate = CHAPCS_RESPONSE;
807
    TIMEOUT(ChapResponseTimeout, cstate, cstate->timeouttime);
808
    ++cstate->resp_transmits;
809
}
810
 
811
/*
812
 * ChapPrintPkt - print the contents of a CHAP packet.
813
 */
814
static char *ChapCodenames[] = {
815
    "Challenge", "Response", "Success", "Failure"
816
};
817
 
818
static int
819
ChapPrintPkt(p, plen, printer, arg)
820
    u_char *p;
821
    int plen;
822
    void (*printer) __P((void *, char *, ...));
823
    void *arg;
824
{
825
    int code, id, len;
826
    int clen, nlen;
827
    u_char x;
828
    if (plen < CHAP_HEADERLEN)
829
        return 0;
830
    GETCHAR(code, p);
831
    GETCHAR(id, p);
832
    GETSHORT(len, p);
833
    if (len < CHAP_HEADERLEN || len > plen)
834
        return 0;
835
 
836
    if (code >= 1 && code <= sizeof(ChapCodenames) / sizeof(char *))
837
        printer(arg, " %s", ChapCodenames[code-1]);
838
    else
839
        printer(arg, " code=0x%x", code);
840
    printer(arg, " id=0x%x", id);
841
    len -= CHAP_HEADERLEN;
842
    switch (code) {
843
    case CHAP_CHALLENGE:
844
    case CHAP_RESPONSE:
845
        if (len < 1)
846
            break;
847
        clen = p[0];
848
        if (len < clen + 1)
849
            break;
850
        ++p;
851
        nlen = len - clen - 1;
852
        printer(arg, " <");
853
        for (; clen > 0; --clen) {
854
            GETCHAR(x, p);
855
            printer(arg, "%.2x", x);
856
        }
857
        printer(arg, ">, name = ");
858
        print_string((char *)p, nlen, printer, arg);
859
        break;
860
    case CHAP_FAILURE:
861
    case CHAP_SUCCESS:
862
        printer(arg, " ");
863
        print_string((char *)p, len, printer, arg);
864
        break;
865
    default:
866
        for (clen = len; clen > 0; --clen) {
867
            GETCHAR(x, p);
868
            printer(arg, " %.2x", x);
869
        }
870
    }
871
    return len + CHAP_HEADERLEN;
872
}

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