GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.sbin/pppd/auth.c Lines: 0 431 0.0 %
Date: 2017-11-13 Branches: 0 376 0.0 %

Line Branch Exec Source
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/*	$OpenBSD: auth.c,v 1.38 2016/06/24 17:22:56 tedu Exp $	*/
2
3
/*
4
 * auth.c - PPP authentication and phase control.
5
 *
6
 * Copyright (c) 1989-2002 Paul Mackerras. All rights reserved.
7
 *
8
 * Redistribution and use in source and binary forms, with or without
9
 * modification, are permitted provided that the following conditions
10
 * are met:
11
 *
12
 * 1. Redistributions of source code must retain the above copyright
13
 *    notice, this list of conditions and the following disclaimer.
14
 *
15
 * 2. Redistributions in binary form must reproduce the above copyright
16
 *    notice, this list of conditions and the following disclaimer in
17
 *    the documentation and/or other materials provided with the
18
 *    distribution.
19
 *
20
 * 3. The name(s) of the authors of this software must not be used to
21
 *    endorse or promote products derived from this software without
22
 *    prior written permission.
23
 *
24
 * 4. Redistributions of any form whatsoever must retain the following
25
 *    acknowledgment:
26
 *    "This product includes software developed by Paul Mackerras
27
 *     <paulus@samba.org>".
28
 *
29
 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
30
 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
31
 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
32
 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
33
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
34
 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
35
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
36
 *
37
 * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
38
 *
39
 * Redistribution and use in source and binary forms, with or without
40
 * modification, are permitted provided that the following conditions
41
 * are met:
42
 *
43
 * 1. Redistributions of source code must retain the above copyright
44
 *    notice, this list of conditions and the following disclaimer.
45
 *
46
 * 2. Redistributions in binary form must reproduce the above copyright
47
 *    notice, this list of conditions and the following disclaimer in
48
 *    the documentation and/or other materials provided with the
49
 *    distribution.
50
 *
51
 * 3. The name "Carnegie Mellon University" must not be used to
52
 *    endorse or promote products derived from this software without
53
 *    prior written permission. For permission or any legal
54
 *    details, please contact
55
 *      Office of Technology Transfer
56
 *      Carnegie Mellon University
57
 *      5000 Forbes Avenue
58
 *      Pittsburgh, PA  15213-3890
59
 *      (412) 268-4387, fax: (412) 268-7395
60
 *      tech-transfer@andrew.cmu.edu
61
 *
62
 * 4. Redistributions of any form whatsoever must retain the following
63
 *    acknowledgment:
64
 *    "This product includes software developed by Computing Services
65
 *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
66
 *
67
 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
68
 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
69
 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
70
 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
71
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
72
 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
73
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
74
 */
75
76
#include <stdio.h>
77
#include <stddef.h>
78
#include <stdlib.h>
79
#include <unistd.h>
80
#include <limits.h>
81
#include <syslog.h>
82
#include <pwd.h>
83
#include <string.h>
84
#include <sys/types.h>
85
#include <sys/stat.h>
86
#include <sys/socket.h>
87
#include <utmp.h>
88
#include <fcntl.h>
89
#if defined(_PATH_LASTLOG) && defined(_linux_)
90
#include <lastlog.h>
91
#endif
92
93
#include <netdb.h>
94
#include <netinet/in.h>
95
#include <arpa/inet.h>
96
97
98
99
#include "pppd.h"
100
#include "fsm.h"
101
#include "lcp.h"
102
#include "ipcp.h"
103
#include "upap.h"
104
#include "chap.h"
105
#ifdef CBCP_SUPPORT
106
#include "cbcp.h"
107
#endif
108
#include "pathnames.h"
109
110
/* Used for storing a sequence of words.  Usually malloced. */
111
struct wordlist {
112
    struct wordlist	*next;
113
    char		word[1];
114
};
115
116
/* Bits in scan_authfile return value */
117
#define NONWILD_SERVER	1
118
#define NONWILD_CLIENT	2
119
120
#define ISWILD(word)	(word[0] == '*' && word[1] == 0)
121
122
#define FALSE	0
123
#define TRUE	1
124
125
/* The name by which the peer authenticated itself to us. */
126
char peer_authname[MAXNAMELEN];
127
128
/* Records which authentication operations haven't completed yet. */
129
static int auth_pending[NUM_PPP];
130
131
/* Set if we have successfully called plogin() */
132
static int logged_in;
133
134
/* Set if we have run the /etc/ppp/auth-up script. */
135
static int did_authup;
136
137
/* List of addresses which the peer may use. */
138
static struct wordlist *addresses[NUM_PPP];
139
140
/* Number of network protocols which we have opened. */
141
static int num_np_open;
142
143
/* Number of network protocols which have come up. */
144
static int num_np_up;
145
146
/* Set if we got the contents of passwd[] from the pap-secrets file. */
147
static int passwd_from_file;
148
149
/* Bits in auth_pending[] */
150
#define PAP_WITHPEER	1
151
#define PAP_PEER	2
152
#define CHAP_WITHPEER	4
153
#define CHAP_PEER	8
154
155
extern char *crypt(const char *, const char *);
156
157
/* Prototypes for procedures local to this file. */
158
159
static void network_phase(int);
160
static void check_idle(void *);
161
static void connect_time_expired(void *);
162
static int  plogin(char *, char *, char **, int *);
163
static void plogout(void);
164
static int  null_login(int);
165
static int  get_pap_passwd(char *);
166
static int  have_pap_secret(void);
167
static int  have_chap_secret(char *, char *, u_int32_t);
168
static int  ip_addr_check(u_int32_t, struct wordlist *);
169
static int  scan_authfile(FILE *, char *, char *, u_int32_t, char *,
170
		struct wordlist **, char *);
171
static void free_wordlist(struct wordlist *);
172
static void auth_script(char *);
173
static void set_allowed_addrs(int, struct wordlist *);
174
175
/*
176
 * An Open on LCP has requested a change from Dead to Establish phase.
177
 * Do what's necessary to bring the physical layer up.
178
 */
179
void
180
link_required(unit)
181
    int unit;
182
{
183
}
184
185
/*
186
 * LCP has terminated the link; go to the Dead phase and take the
187
 * physical layer down.
188
 */
189
void
190
link_terminated(unit)
191
    int unit;
192
{
193
    if (phase == PHASE_DEAD)
194
	return;
195
    if (logged_in)
196
	plogout();
197
    phase = PHASE_DEAD;
198
    syslog(LOG_NOTICE, "Connection terminated.");
199
}
200
201
/*
202
 * LCP has gone down; it will either die or try to re-establish.
203
 */
204
void
205
link_down(unit)
206
    int unit;
207
{
208
    int i;
209
    struct protent *protp;
210
211
    if (did_authup) {
212
	auth_script(_PATH_AUTHDOWN);
213
	did_authup = 0;
214
    }
215
    for (i = 0; (protp = protocols[i]) != NULL; ++i) {
216
	if (!protp->enabled_flag)
217
	    continue;
218
        if (protp->protocol != PPP_LCP && protp->lowerdown != NULL)
219
	    (*protp->lowerdown)(unit);
220
        if (protp->protocol < 0xC000 && protp->close != NULL)
221
	    (*protp->close)(unit, "LCP down");
222
    }
223
    num_np_open = 0;
224
    num_np_up = 0;
225
    if (phase != PHASE_DEAD)
226
	phase = PHASE_TERMINATE;
227
}
228
229
/*
230
 * The link is established.
231
 * Proceed to the Dead, Authenticate or Network phase as appropriate.
232
 */
233
void
234
link_established(unit)
235
    int unit;
236
{
237
    int auth;
238
    lcp_options *wo = &lcp_wantoptions[unit];
239
    lcp_options *go = &lcp_gotoptions[unit];
240
    lcp_options *ho = &lcp_hisoptions[unit];
241
    int i;
242
    struct protent *protp;
243
244
    /*
245
     * Tell higher-level protocols that LCP is up.
246
     */
247
    for (i = 0; (protp = protocols[i]) != NULL; ++i)
248
        if (protp->protocol != PPP_LCP && protp->enabled_flag
249
	    && protp->lowerup != NULL)
250
	    (*protp->lowerup)(unit);
251
252
    if (auth_required && !(go->neg_chap || go->neg_upap)) {
253
	/*
254
	 * We wanted the peer to authenticate itself, and it refused:
255
	 * treat it as though it authenticated with PAP using a username
256
	 * of "" and a password of "".  If that's not OK, boot it out.
257
	 */
258
	if (!wo->neg_upap || !null_login(unit)) {
259
	    syslog(LOG_WARNING, "peer refused to authenticate");
260
	    lcp_close(unit, "peer refused to authenticate");
261
	    return;
262
	}
263
    }
264
265
    phase = PHASE_AUTHENTICATE;
266
    auth = 0;
267
    if (go->neg_chap) {
268
	ChapAuthPeer(unit, our_name, go->chap_mdtype);
269
	auth |= CHAP_PEER;
270
    } else if (go->neg_upap) {
271
	upap_authpeer(unit);
272
	auth |= PAP_PEER;
273
    }
274
    if (ho->neg_chap) {
275
	ChapAuthWithPeer(unit, user, ho->chap_mdtype);
276
	auth |= CHAP_WITHPEER;
277
    } else if (ho->neg_upap) {
278
	if (passwd[0] == 0) {
279
	    passwd_from_file = 1;
280
	    if (!get_pap_passwd(passwd))
281
		syslog(LOG_ERR, "No secret found for PAP login");
282
	}
283
	upap_authwithpeer(unit, user, passwd);
284
	auth |= PAP_WITHPEER;
285
    }
286
    auth_pending[unit] = auth;
287
288
    if (!auth)
289
	network_phase(unit);
290
}
291
292
/*
293
 * Proceed to the network phase.
294
 */
295
static void
296
network_phase(unit)
297
    int unit;
298
{
299
    int i;
300
    struct protent *protp;
301
    lcp_options *go = &lcp_gotoptions[unit];
302
303
    /*
304
     * If the peer had to authenticate, run the auth-up script now.
305
     */
306
    if ((go->neg_chap || go->neg_upap) && !did_authup) {
307
	auth_script(_PATH_AUTHUP);
308
	did_authup = 1;
309
    }
310
311
#ifdef CBCP_SUPPORT
312
    /*
313
     * If we negotiated callback, do it now.
314
     */
315
    if (go->neg_cbcp) {
316
	phase = PHASE_CALLBACK;
317
	(*cbcp_protent.open)(unit);
318
	return;
319
    }
320
#endif
321
322
    phase = PHASE_NETWORK;
323
#if 0
324
    if (!demand)
325
	set_filters(&pass_filter, &active_filter);
326
#endif
327
    for (i = 0; (protp = protocols[i]) != NULL; ++i)
328
        if (protp->protocol < 0xC000 && protp->enabled_flag
329
	    && protp->open != NULL) {
330
	    (*protp->open)(unit);
331
	    if (protp->protocol != PPP_CCP)
332
		++num_np_open;
333
	}
334
335
    if (num_np_open == 0)
336
	/* nothing to do */
337
	lcp_close(0, "No network protocols running");
338
}
339
340
/*
341
 * The peer has failed to authenticate himself using `protocol'.
342
 */
343
void
344
auth_peer_fail(unit, protocol)
345
    int unit, protocol;
346
{
347
    /*
348
     * Authentication failure: take the link down
349
     */
350
    lcp_close(unit, "Authentication failed");
351
}
352
353
/*
354
 * The peer has been successfully authenticated using `protocol'.
355
 */
356
void
357
auth_peer_success(unit, protocol, name, namelen)
358
    int unit, protocol;
359
    char *name;
360
    int namelen;
361
{
362
    int bit;
363
364
    switch (protocol) {
365
    case PPP_CHAP:
366
	bit = CHAP_PEER;
367
	break;
368
    case PPP_PAP:
369
	bit = PAP_PEER;
370
	break;
371
    default:
372
	syslog(LOG_WARNING, "auth_peer_success: unknown protocol %x",
373
	       protocol);
374
	return;
375
    }
376
377
    /*
378
     * Save the authenticated name of the peer for later.
379
     */
380
    if (namelen > sizeof(peer_authname) - 1)
381
	namelen = sizeof(peer_authname) - 1;
382
    BCOPY(name, peer_authname, namelen);
383
    peer_authname[namelen] = 0;
384
    script_setenv("PEERNAME", peer_authname);
385
386
    /*
387
     * If there is no more authentication still to be done,
388
     * proceed to the network (or callback) phase.
389
     */
390
    if ((auth_pending[unit] &= ~bit) == 0)
391
        network_phase(unit);
392
}
393
394
/*
395
 * We have failed to authenticate ourselves to the peer using `protocol'.
396
 */
397
void
398
auth_withpeer_fail(unit, protocol)
399
    int unit, protocol;
400
{
401
    if (passwd_from_file)
402
	BZERO(passwd, MAXSECRETLEN);
403
    /*
404
     * We've failed to authenticate ourselves to our peer.
405
     * He'll probably take the link down, and there's not much
406
     * we can do except wait for that.
407
     */
408
}
409
410
/*
411
 * We have successfully authenticated ourselves with the peer using `protocol'.
412
 */
413
void
414
auth_withpeer_success(unit, protocol)
415
    int unit, protocol;
416
{
417
    int bit;
418
419
    switch (protocol) {
420
    case PPP_CHAP:
421
	bit = CHAP_WITHPEER;
422
	break;
423
    case PPP_PAP:
424
	if (passwd_from_file)
425
	    BZERO(passwd, MAXSECRETLEN);
426
	bit = PAP_WITHPEER;
427
	break;
428
    default:
429
	syslog(LOG_WARNING, "auth_peer_success: unknown protocol %x",
430
	       protocol);
431
	bit = 0;
432
    }
433
434
    /*
435
     * If there is no more authentication still being done,
436
     * proceed to the network (or callback) phase.
437
     */
438
    if ((auth_pending[unit] &= ~bit) == 0)
439
	network_phase(unit);
440
}
441
442
443
/*
444
 * np_up - a network protocol has come up.
445
 */
446
void
447
np_up(unit, proto)
448
    int unit, proto;
449
{
450
    if (num_np_up == 0) {
451
	/*
452
	 * At this point we consider that the link has come up successfully.
453
	 */
454
	need_holdoff = 0;
455
456
	if (idle_time_limit > 0)
457
	    TIMEOUT(check_idle, NULL, idle_time_limit);
458
459
	/*
460
	 * Set a timeout to close the connection once the maximum
461
	 * connect time has expired.
462
	 */
463
	if (maxconnect > 0)
464
	    TIMEOUT(connect_time_expired, 0, maxconnect);
465
466
	/*
467
	 * Detach now, if the updetach option was given.
468
	 */
469
	if (nodetach == -1)
470
	    detach();
471
    }
472
    ++num_np_up;
473
}
474
475
/*
476
 * np_down - a network protocol has gone down.
477
 */
478
void
479
np_down(unit, proto)
480
    int unit, proto;
481
{
482
    if (--num_np_up == 0 && idle_time_limit > 0) {
483
	UNTIMEOUT(check_idle, NULL);
484
    }
485
}
486
487
/*
488
 * np_finished - a network protocol has finished using the link.
489
 */
490
void
491
np_finished(unit, proto)
492
    int unit, proto;
493
{
494
    if (--num_np_open <= 0) {
495
	/* no further use for the link: shut up shop. */
496
	lcp_close(0, "No network protocols running");
497
    }
498
}
499
500
/*
501
 * check_idle - check whether the link has been idle for long
502
 * enough that we can shut it down.
503
 */
504
static void
505
check_idle(arg)
506
    void *arg;
507
{
508
    struct ppp_idle idle;
509
    time_t itime;
510
511
    if (!get_idle_time(0, &idle))
512
	return;
513
    itime = MIN(idle.xmit_idle, idle.recv_idle);
514
    if (itime >= idle_time_limit) {
515
	/* link is idle: shut it down. */
516
	syslog(LOG_INFO, "Terminating connection due to lack of activity.");
517
	lcp_close(0, "Link inactive");
518
    } else {
519
	TIMEOUT(check_idle, NULL, idle_time_limit - itime);
520
    }
521
}
522
523
/*
524
 * connect_time_expired - log a message and close the connection.
525
 */
526
static void
527
connect_time_expired(arg)
528
    void *arg;
529
{
530
    syslog(LOG_INFO, "Connect time expired");
531
    lcp_close(0, "Connect time expired");	/* Close connection */
532
}
533
534
/*
535
 * auth_check_options - called to check authentication options.
536
 */
537
void
538
auth_check_options()
539
{
540
    lcp_options *wo = &lcp_wantoptions[0];
541
    int can_auth;
542
    ipcp_options *ipwo = &ipcp_wantoptions[0];
543
    u_int32_t remote;
544
545
    /* Default our_name to hostname, and user to our_name */
546
    if (our_name[0] == 0 || usehostname)
547
	strlcpy(our_name, hostname, HOST_NAME_MAX+1);
548
    if (user[0] == 0)
549
	strlcpy(user, our_name, MAXNAMELEN);
550
551
    /* If authentication is required, ask peer for CHAP or PAP. */
552
    if (auth_required && !wo->neg_chap && !wo->neg_upap) {
553
	wo->neg_chap = 1;
554
	wo->neg_upap = 1;
555
    }
556
557
    /*
558
     * Check whether we have appropriate secrets to use
559
     * to authenticate the peer.
560
     */
561
    can_auth = wo->neg_upap && (uselogin || have_pap_secret());
562
    if (!can_auth && wo->neg_chap) {
563
	remote = ipwo->accept_remote? 0: ipwo->hisaddr;
564
	can_auth = have_chap_secret(remote_name, our_name, remote);
565
    }
566
567
    if (auth_required && !can_auth) {
568
	option_error("peer authentication required but no suitable secret(s) found\n");
569
	if (remote_name[0] == 0)
570
	    option_error("for authenticating any peer to us (%s)\n", our_name);
571
	else
572
	    option_error("for authenticating peer %s to us (%s)\n",
573
			 remote_name, our_name);
574
	exit(1);
575
    }
576
577
    /*
578
     * Check whether the user tried to override certain values
579
     * set by root.
580
     */
581
    if (!auth_required && auth_req_info.priv > 0) {
582
	if (!default_device && devnam_info.priv == 0) {
583
	    option_error("can't override device name when noauth option used");
584
	    exit(1);
585
	}
586
	if ((connector != NULL && connector_info.priv == 0)
587
	    || (disconnector != NULL && disconnector_info.priv == 0)
588
	    || (welcomer != NULL && welcomer_info.priv == 0)) {
589
	    option_error("can't override connect, disconnect or welcome");
590
	    option_error("option values when noauth option used");
591
	    exit(1);
592
	}
593
    }
594
}
595
596
/*
597
 * auth_reset - called when LCP is starting negotiations to recheck
598
 * authentication options, i.e. whether we have appropriate secrets
599
 * to use for authenticating ourselves and/or the peer.
600
 */
601
void
602
auth_reset(unit)
603
    int unit;
604
{
605
    lcp_options *go = &lcp_gotoptions[unit];
606
    lcp_options *ao = &lcp_allowoptions[0];
607
    ipcp_options *ipwo = &ipcp_wantoptions[0];
608
    u_int32_t remote;
609
610
    ao->neg_upap = !refuse_pap && (passwd[0] != 0 || get_pap_passwd(NULL));
611
    ao->neg_chap = !refuse_chap
612
	&& have_chap_secret(user, remote_name, (u_int32_t)0);
613
614
    if (go->neg_upap && !uselogin && !have_pap_secret())
615
	go->neg_upap = 0;
616
    if (go->neg_chap) {
617
	remote = ipwo->accept_remote? 0: ipwo->hisaddr;
618
	if (!have_chap_secret(remote_name, our_name, remote))
619
	    go->neg_chap = 0;
620
    }
621
}
622
623
624
/*
625
 * check_passwd - Check the user name and passwd against the PAP secrets
626
 * file.  If requested, also check against the system password database,
627
 * and login the user if OK.
628
 *
629
 * returns:
630
 *	UPAP_AUTHNAK: Authentication failed.
631
 *	UPAP_AUTHACK: Authentication succeeded.
632
 * In either case, msg points to an appropriate message.
633
 */
634
int
635
check_passwd(unit, auser, userlen, apasswd, passwdlen, msg, msglen)
636
    int unit;
637
    char *auser;
638
    int userlen;
639
    char *apasswd;
640
    int passwdlen;
641
    char **msg;
642
    int *msglen;
643
{
644
    int ret;
645
    char *filename;
646
    FILE *f;
647
    struct wordlist *addrs;
648
    u_int32_t remote;
649
    ipcp_options *ipwo = &ipcp_wantoptions[unit];
650
    char passwd[256], user[256];
651
    char secret[MAXWORDLEN];
652
    static int attempts = 0;
653
654
    /*
655
     * Make copies of apasswd and auser, then null-terminate them.
656
     */
657
    BCOPY(apasswd, passwd, passwdlen);
658
    passwd[passwdlen] = '\0';
659
    BCOPY(auser, user, userlen);
660
    user[userlen] = '\0';
661
    *msg = (char *) 0;
662
663
    /*
664
     * Open the file of pap secrets and scan for a suitable secret
665
     * for authenticating this user.
666
     */
667
    filename = _PATH_UPAPFILE;
668
    addrs = NULL;
669
    ret = UPAP_AUTHACK;
670
    f = fopen(filename, "r");
671
    if (f == NULL) {
672
	syslog(LOG_ERR, "Can't open PAP password file %s: %m", filename);
673
	ret = UPAP_AUTHNAK;
674
    } else {
675
	check_access(f, filename);
676
	remote = ipwo->accept_remote? 0: ipwo->hisaddr;
677
	if (scan_authfile(f, user, our_name, remote,
678
			  secret, &addrs, filename) < 0
679
	    || (secret[0] != 0 && (cryptpap || strcmp(passwd, secret) != 0)
680
		&& strcmp(crypt(passwd, secret), secret) != 0)) {
681
	    syslog(LOG_WARNING, "PAP authentication failure for %s", user);
682
	    ret = UPAP_AUTHNAK;
683
	}
684
	fclose(f);
685
    }
686
687
    if (uselogin && ret == UPAP_AUTHACK) {
688
	ret = plogin(user, passwd, msg, msglen);
689
	if (ret == UPAP_AUTHNAK) {
690
	    syslog(LOG_WARNING, "PAP login failure for %s", user);
691
	}
692
    }
693
694
    if (ret == UPAP_AUTHNAK) {
695
        if (*msg == (char *) 0)
696
	    *msg = "Login incorrect";
697
	*msglen = strlen(*msg);
698
	/*
699
	 * Frustrate passwd stealer programs.
700
	 * Allow 10 tries, but start backing off after 3 (stolen from login).
701
	 * On 10'th, drop the connection.
702
	 */
703
	if (attempts++ >= 10) {
704
	    syslog(LOG_WARNING, "%d LOGIN FAILURES ON %s, %s",
705
		   attempts, devnam, user);
706
	    quit();
707
	}
708
	if (attempts > 3)
709
	    sleep((u_int) (attempts - 3) * 5);
710
	if (addrs != NULL)
711
	    free_wordlist(addrs);
712
713
    } else {
714
	attempts = 0;			/* Reset count */
715
	if (*msg == (char *) 0)
716
	    *msg = "Login ok";
717
	*msglen = strlen(*msg);
718
	set_allowed_addrs(unit, addrs);
719
    }
720
721
    BZERO(passwd, sizeof(passwd));
722
    BZERO(secret, sizeof(secret));
723
724
    return ret;
725
}
726
727
/*
728
 * plogin - Check the user name and password against the system
729
 * password database, and login the user if OK.
730
 *
731
 * returns:
732
 *	UPAP_AUTHNAK: Login failed.
733
 *	UPAP_AUTHACK: Login succeeded.
734
 * In either case, msg points to an appropriate message.
735
 */
736
737
static int
738
plogin(user, passwd, msg, msglen)
739
    char *user;
740
    char *passwd;
741
    char **msg;
742
    int *msglen;
743
{
744
    struct passwd *pw;
745
    char *tty;
746
747
    pw = getpwnam_shadow(user);
748
    if (crypt_checkpass(passwd, pw ? pw->pw_passwd : NULL))
749
	    return UPAP_AUTHNAK;
750
751
    /*
752
     * Write a wtmp entry for this user.
753
     */
754
755
    tty = devnam;
756
    if (strncmp(tty, "/dev/", 5) == 0)
757
	tty += 5;
758
    logwtmp(tty, user, remote_name);		/* Add wtmp login entry */
759
760
#if defined(_PATH_LASTLOG)
761
    {
762
	    struct lastlog ll;
763
	    int fd;
764
765
	    if ((fd = open(_PATH_LASTLOG, O_RDWR)) >= 0) {
766
		memset(&ll, 0, sizeof(ll));
767
		(void)time(&ll.ll_time);
768
		(void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
769
		(void)pwrite(fd, &ll, sizeof(ll), (off_t)pw->pw_uid *
770
		    sizeof(ll));
771
		(void)close(fd);
772
	    }
773
    }
774
#endif
775
776
777
    syslog(LOG_INFO, "user %s logged in", user);
778
    logged_in = TRUE;
779
780
    return (UPAP_AUTHACK);
781
}
782
783
/*
784
 * plogout - Logout the user.
785
 */
786
static void
787
plogout()
788
{
789
    char *tty;
790
791
    tty = devnam;
792
    if (strncmp(tty, "/dev/", 5) == 0)
793
	tty += 5;
794
    logwtmp(tty, "", "");		/* Wipe out utmp logout entry */
795
796
    logged_in = FALSE;
797
}
798
799
800
/*
801
 * null_login - Check if a username of "" and a password of "" are
802
 * acceptable, and iff so, set the list of acceptable IP addresses
803
 * and return 1.
804
 */
805
static int
806
null_login(unit)
807
    int unit;
808
{
809
    char *filename;
810
    FILE *f;
811
    int i, ret;
812
    struct wordlist *addrs;
813
    char secret[MAXWORDLEN];
814
815
    /*
816
     * Open the file of pap secrets and scan for a suitable secret.
817
     * We don't accept a wildcard client.
818
     */
819
    filename = _PATH_UPAPFILE;
820
    addrs = NULL;
821
    f = fopen(filename, "r");
822
    if (f == NULL)
823
	return 0;
824
    check_access(f, filename);
825
826
    i = scan_authfile(f, "", our_name, (u_int32_t)0, secret, &addrs, filename);
827
    ret = i >= 0 && (i & NONWILD_CLIENT) != 0 && secret[0] == 0;
828
    BZERO(secret, sizeof(secret));
829
830
    if (ret)
831
	set_allowed_addrs(unit, addrs);
832
    else
833
	free_wordlist(addrs);
834
835
    fclose(f);
836
    return ret;
837
}
838
839
840
/*
841
 * get_pap_passwd - get a password for authenticating ourselves with
842
 * our peer using PAP.  Returns 1 on success, 0 if no suitable password
843
 * could be found.
844
 */
845
static int
846
get_pap_passwd(passwd)
847
    char *passwd;
848
{
849
    char *filename;
850
    FILE *f;
851
    int ret;
852
    char secret[MAXWORDLEN];
853
854
    filename = _PATH_UPAPFILE;
855
    f = fopen(filename, "r");
856
    if (f == NULL)
857
	return 0;
858
    check_access(f, filename);
859
    ret = scan_authfile(f, user,
860
			remote_name[0]? remote_name: NULL,
861
			(u_int32_t)0, secret, NULL, filename);
862
    fclose(f);
863
    if (ret < 0)
864
	return 0;
865
    if (passwd != NULL)
866
	strlcpy(passwd, secret, MAXSECRETLEN);
867
    BZERO(secret, sizeof(secret));
868
    return 1;
869
}
870
871
872
/*
873
 * have_pap_secret - check whether we have a PAP file with any
874
 * secrets that we could possibly use for authenticating the peer.
875
 */
876
static int
877
have_pap_secret()
878
{
879
    FILE *f;
880
    int ret;
881
    char *filename;
882
    ipcp_options *ipwo = &ipcp_wantoptions[0];
883
    u_int32_t remote;
884
885
    filename = _PATH_UPAPFILE;
886
    f = fopen(filename, "r");
887
    if (f == NULL)
888
	return 0;
889
890
    remote = ipwo->accept_remote? 0: ipwo->hisaddr;
891
    ret = scan_authfile(f, NULL, our_name, remote, NULL, NULL, filename);
892
    fclose(f);
893
    if (ret < 0)
894
	return 0;
895
896
    return 1;
897
}
898
899
900
/*
901
 * have_chap_secret - check whether we have a CHAP file with a
902
 * secret that we could possibly use for authenticating `client'
903
 * on `server'.  Either can be the null string, meaning we don't
904
 * know the identity yet.
905
 */
906
static int
907
have_chap_secret(client, server, remote)
908
    char *client;
909
    char *server;
910
    u_int32_t remote;
911
{
912
    FILE *f;
913
    int ret;
914
    char *filename;
915
916
    filename = _PATH_CHAPFILE;
917
    f = fopen(filename, "r");
918
    if (f == NULL)
919
	return 0;
920
921
    if (client[0] == 0)
922
	client = NULL;
923
    else if (server[0] == 0)
924
	server = NULL;
925
926
    ret = scan_authfile(f, client, server, remote, NULL, NULL, filename);
927
    fclose(f);
928
    if (ret < 0)
929
	return 0;
930
931
    return 1;
932
}
933
934
935
/*
936
 * get_secret - open the CHAP secret file and return the secret
937
 * for authenticating the given client on the given server.
938
 * (We could be either client or server).
939
 */
940
int
941
get_secret(unit, client, server, secret, secret_len, save_addrs)
942
    int unit;
943
    char *client;
944
    char *server;
945
    char *secret;
946
    int *secret_len;
947
    int save_addrs;
948
{
949
    FILE *f;
950
    int ret, len;
951
    char *filename;
952
    struct wordlist *addrs;
953
    char secbuf[MAXWORDLEN];
954
955
    filename = _PATH_CHAPFILE;
956
    addrs = NULL;
957
    secbuf[0] = 0;
958
959
    f = fopen(filename, "r");
960
    if (f == NULL) {
961
	syslog(LOG_ERR, "Can't open chap secret file %s: %m", filename);
962
	return 0;
963
    }
964
    check_access(f, filename);
965
966
    ret = scan_authfile(f, client, server, (u_int32_t)0,
967
			secbuf, &addrs, filename);
968
    fclose(f);
969
    if (ret < 0)
970
	return 0;
971
972
    if (save_addrs)
973
	set_allowed_addrs(unit, addrs);
974
975
    len = strlen(secbuf);
976
    if (len > MAXSECRETLEN) {
977
	syslog(LOG_ERR, "Secret for %s on %s is too long", client, server);
978
	len = MAXSECRETLEN;
979
    }
980
    BCOPY(secbuf, secret, len);
981
    BZERO(secbuf, sizeof(secbuf));
982
    *secret_len = len;
983
984
    return 1;
985
}
986
987
/*
988
 * set_allowed_addrs() - set the list of allowed addresses.
989
 */
990
static void
991
set_allowed_addrs(unit, addrs)
992
    int unit;
993
    struct wordlist *addrs;
994
{
995
    if (addresses[unit] != NULL)
996
	free_wordlist(addresses[unit]);
997
    addresses[unit] = addrs;
998
999
    /*
1000
     * If there's only one authorized address we might as well
1001
     * ask our peer for that one right away
1002
     */
1003
    if (addrs != NULL && addrs->next == NULL) {
1004
	char *p = addrs->word;
1005
	struct ipcp_options *wo = &ipcp_wantoptions[unit];
1006
	struct in_addr ina;
1007
	struct hostent *hp;
1008
1009
	if (*p != '!' && *p != '-' && !ISWILD(p) && strchr(p, '/') == NULL) {
1010
	    hp = gethostbyname(p);
1011
	    if (hp != NULL && hp->h_addrtype == AF_INET)
1012
		wo->hisaddr = *(u_int32_t *)hp->h_addr;
1013
	    else if (inet_aton(p, &ina) == 1)
1014
		wo->hisaddr = ina.s_addr;
1015
	}
1016
    }
1017
}
1018
1019
/*
1020
 * auth_ip_addr - check whether the peer is authorized to use
1021
 * a given IP address.  Returns 1 if authorized, 0 otherwise.
1022
 */
1023
int
1024
auth_ip_addr(unit, addr)
1025
    int unit;
1026
    u_int32_t addr;
1027
{
1028
    return ip_addr_check(addr, addresses[unit]);
1029
}
1030
1031
static int
1032
ip_addr_check(addr, addrs)
1033
    u_int32_t addr;
1034
    struct wordlist *addrs;
1035
{
1036
    u_int32_t mask, ah;
1037
    struct in_addr ina;
1038
    int accept, r = 1;
1039
    char *ptr_word, *ptr_mask;
1040
    struct hostent *hp;
1041
1042
    /* don't allow loopback or multicast address */
1043
    if (bad_ip_adrs(addr))
1044
	return 0;
1045
1046
    if (addrs == NULL)
1047
	return !auth_required;		/* no addresses authorized */
1048
1049
    for (; addrs != NULL; addrs = addrs->next) {
1050
	/* "-" means no addresses authorized, "*" means any address allowed */
1051
	ptr_word = addrs->word;
1052
	if (strcmp(ptr_word, "-") == 0)
1053
	    break;
1054
	if (strcmp(ptr_word, "*") == 0)
1055
	    return 1;
1056
1057
	accept = 1;
1058
	if (*ptr_word == '!') {
1059
	    accept = 0;
1060
	    ++ptr_word;
1061
	}
1062
1063
	mask = ~ (u_int32_t) 0;
1064
	ptr_mask = strchr (ptr_word, '/');
1065
	if (ptr_mask != NULL) {
1066
	    int bit_count;
1067
1068
	    bit_count = (int) strtol (ptr_mask+1, (char **) 0, 10);
1069
	    if (bit_count <= 0 || bit_count > 32) {
1070
		syslog (LOG_WARNING,
1071
			"invalid address length %s in auth. address list",
1072
			ptr_mask);
1073
		continue;
1074
	    }
1075
	    *ptr_mask = '\0';
1076
	    mask <<= 32 - bit_count;
1077
	}
1078
1079
	hp = gethostbyname(ptr_word);
1080
	if (hp != NULL && hp->h_addrtype == AF_INET) {
1081
	    ina.s_addr = *(u_int32_t *)hp->h_addr;
1082
	} else {
1083
	    r = inet_aton (ptr_word, &ina);
1084
	    if (ptr_mask == NULL) {
1085
		/* calculate appropriate mask for net */
1086
		ah = ntohl(ina.s_addr);
1087
		if (IN_CLASSA(ah))
1088
		    mask = IN_CLASSA_NET;
1089
		else if (IN_CLASSB(ah))
1090
		    mask = IN_CLASSB_NET;
1091
		else if (IN_CLASSC(ah))
1092
		    mask = IN_CLASSC_NET;
1093
	    }
1094
	}
1095
1096
	if (ptr_mask != NULL)
1097
	    *ptr_mask = '/';
1098
1099
	if (r == 0)
1100
	    syslog (LOG_WARNING,
1101
		    "unknown host %s in auth. address list",
1102
		    addrs->word);
1103
	else
1104
	    /* Here ina.s_addr and addr are in network byte order,
1105
	       and mask is in host order. */
1106
	    if (((addr ^ ina.s_addr) & htonl(mask)) == 0)
1107
		return accept;
1108
    }
1109
    return 0;			/* not in list => can't have it */
1110
}
1111
1112
/*
1113
 * bad_ip_adrs - return 1 if the IP address is one we don't want
1114
 * to use, such as an address in the loopback net or a multicast address.
1115
 * addr is in network byte order.
1116
 */
1117
int
1118
bad_ip_adrs(addr)
1119
    u_int32_t addr;
1120
{
1121
    addr = ntohl(addr);
1122
    return (addr >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET
1123
	|| IN_MULTICAST(addr) || IN_BADCLASS(addr);
1124
}
1125
1126
/*
1127
 * check_access - complain if a secret file has too-liberal permissions.
1128
 */
1129
void
1130
check_access(f, filename)
1131
    FILE *f;
1132
    char *filename;
1133
{
1134
    struct stat sbuf;
1135
1136
    if (fstat(fileno(f), &sbuf) < 0) {
1137
	syslog(LOG_WARNING, "cannot stat secret file %s: %m", filename);
1138
    } else if ((sbuf.st_mode & (S_IRWXG | S_IRWXO)) != 0) {
1139
	syslog(LOG_WARNING, "Warning - secret file %s has world and/or group access", filename);
1140
    }
1141
}
1142
1143
1144
/*
1145
 * scan_authfile - Scan an authorization file for a secret suitable
1146
 * for authenticating `client' on `server'.  The return value is -1
1147
 * if no secret is found, otherwise >= 0.  The return value has
1148
 * NONWILD_CLIENT set if the secret didn't have "*" for the client, and
1149
 * NONWILD_SERVER set if the secret didn't have "*" for the server.
1150
 * Any following words on the line (i.e. address authorization
1151
 * info) are placed in a wordlist and returned in *addrs.
1152
 */
1153
static int
1154
scan_authfile(f, client, server, ipaddr, secret, addrs, filename)
1155
    FILE *f;
1156
    char *client;
1157
    char *server;
1158
    u_int32_t ipaddr;
1159
    char *secret;
1160
    struct wordlist **addrs;
1161
    char *filename;
1162
{
1163
    int newline, xxx;
1164
    int got_flag, best_flag;
1165
    FILE *sf;
1166
    struct wordlist *ap, *addr_list, *alist, *alast;
1167
    char word[MAXWORDLEN];
1168
    char atfile[MAXWORDLEN];
1169
    char lsecret[MAXWORDLEN];
1170
1171
    if (addrs != NULL)
1172
	*addrs = NULL;
1173
    addr_list = NULL;
1174
    if (!getword(f, word, &newline, filename))
1175
	return -1;		/* file is empty??? */
1176
    newline = 1;
1177
    best_flag = -1;
1178
    for (;;) {
1179
	/*
1180
	 * Skip until we find a word at the start of a line.
1181
	 */
1182
	while (!newline && getword(f, word, &newline, filename))
1183
	    ;
1184
	if (!newline)
1185
	    break;		/* got to end of file */
1186
1187
	/*
1188
	 * Got a client - check if it's a match or a wildcard.
1189
	 */
1190
	got_flag = 0;
1191
	if (client != NULL && strcmp(word, client) != 0 && !ISWILD(word)) {
1192
	    newline = 0;
1193
	    continue;
1194
	}
1195
	if (!ISWILD(word))
1196
	    got_flag = NONWILD_CLIENT;
1197
1198
	/*
1199
	 * Now get a server and check if it matches.
1200
	 */
1201
	if (!getword(f, word, &newline, filename))
1202
	    break;
1203
	if (newline)
1204
	    continue;
1205
	if (server != NULL && strcmp(word, server) != 0 && !ISWILD(word))
1206
	    continue;
1207
	if (!ISWILD(word))
1208
	    got_flag |= NONWILD_SERVER;
1209
1210
	/*
1211
	 * Got some sort of a match - see if it's better than what
1212
	 * we have already.
1213
	 */
1214
	if (got_flag <= best_flag)
1215
	    continue;
1216
1217
	/*
1218
	 * Get the secret.
1219
	 */
1220
	if (!getword(f, word, &newline, filename))
1221
	    break;
1222
	if (newline)
1223
	    continue;
1224
1225
	/*
1226
	 * Special syntax: @filename means read secret from file.
1227
	 */
1228
	if (word[0] == '@') {
1229
	    strlcpy(atfile, word+1, sizeof atfile);
1230
	    if ((sf = fopen(atfile, "r")) == NULL) {
1231
		syslog(LOG_WARNING, "can't open indirect secret file %s",
1232
		       atfile);
1233
		continue;
1234
	    }
1235
	    check_access(sf, atfile);
1236
	    if (!getword(sf, word, &xxx, atfile)) {
1237
		syslog(LOG_WARNING, "no secret in indirect secret file %s",
1238
		       atfile);
1239
		fclose(sf);
1240
		continue;
1241
	    }
1242
	    fclose(sf);
1243
	}
1244
	if (secret != NULL)
1245
	    strlcpy(lsecret, word, sizeof lsecret);
1246
1247
	/*
1248
	 * Now read address authorization info and make a wordlist.
1249
	 */
1250
	alist = alast = NULL;
1251
	for (;;) {
1252
	    size_t wordlen;
1253
1254
	    if (!getword(f, word, &newline, filename) || newline)
1255
		break;
1256
	    wordlen = strlen(word);	/* NUL in struct wordlist */
1257
	    ap = (struct wordlist *) malloc(sizeof(struct wordlist) +
1258
		wordlen);
1259
1260
	    if (ap == NULL)
1261
		novm("authorized addresses");
1262
	    ap->next = NULL;
1263
	    strlcpy(ap->word, word, wordlen + 1);
1264
	    if (alist == NULL)
1265
		alist = ap;
1266
	    else
1267
		alast->next = ap;
1268
	    alast = ap;
1269
	}
1270
1271
	/*
1272
	 * Check if the given IP address is allowed by the wordlist.
1273
	 */
1274
	if (ipaddr != 0 && !ip_addr_check(ipaddr, alist)) {
1275
	    free_wordlist(alist);
1276
	    continue;
1277
	}
1278
1279
	/*
1280
	 * This is the best so far; remember it.
1281
	 */
1282
	best_flag = got_flag;
1283
	if (addr_list)
1284
	    free_wordlist(addr_list);
1285
	addr_list = alist;
1286
	if (secret != NULL)
1287
	    strlcpy(secret, lsecret, MAXWORDLEN);
1288
1289
	if (!newline)
1290
	    break;
1291
    }
1292
1293
    if (addrs != NULL)
1294
	*addrs = addr_list;
1295
    else if (addr_list != NULL)
1296
	free_wordlist(addr_list);
1297
1298
    return best_flag;
1299
}
1300
1301
/*
1302
 * free_wordlist - release memory allocated for a wordlist.
1303
 */
1304
static void
1305
free_wordlist(wp)
1306
    struct wordlist *wp;
1307
{
1308
    struct wordlist *next;
1309
1310
    while (wp != NULL) {
1311
	next = wp->next;
1312
	free(wp);
1313
	wp = next;
1314
    }
1315
}
1316
1317
/*
1318
 * auth_script - execute a script with arguments
1319
 * interface-name peer-name real-user tty speed
1320
 */
1321
static void
1322
auth_script(script)
1323
    char *script;
1324
{
1325
    char strspeed[32];
1326
    struct passwd *pw;
1327
    char struid[32];
1328
    char *user_name;
1329
    char *argv[8];
1330
1331
    if ((pw = getpwuid(getuid())) != NULL && pw->pw_name != NULL)
1332
	user_name = pw->pw_name;
1333
    else {
1334
	snprintf(struid, sizeof struid, "%u", getuid());
1335
	user_name = struid;
1336
    }
1337
    snprintf(strspeed, sizeof strspeed, "%d", baud_rate);
1338
1339
    argv[0] = script;
1340
    argv[1] = ifname;
1341
    argv[2] = peer_authname;
1342
    argv[3] = user_name;
1343
    argv[4] = devnam;
1344
    argv[5] = strspeed;
1345
    argv[6] = NULL;
1346
1347
    run_program(script, argv, 0);
1348
}