forked from kravietz/pam_tacplus
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathpam_tacplus.c
1052 lines (862 loc) · 27.5 KB
/
pam_tacplus.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/* pam_tacplus.c - PAM interface for TACACS+ protocol.
*
* Copyright (C) 2010, Pawel Krawczyk <pawel.krawczyk@hush.com> and
* Jeroen Nijhof <jeroen@jeroennijhof.nl>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program - see the file COPYING.
*
* See `CHANGES' file for revision history.
*/
#include "pam_tacplus.h"
#include "support.h"
#include <stdlib.h> /* malloc */
#include <stdio.h>
#include <syslog.h>
#include <netdb.h> /* gethostbyname */
#include <sys/socket.h> /* in_addr */
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdarg.h> /* va_ */
#include <signal.h>
#include <string.h> /* strdup */
#include <ctype.h>
#include <time.h>
#include <unistd.h>
#include <strings.h>
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#if defined(HAVE_OPENSSL_RAND_H) && defined(HAVE_LIBCRYPTO)
# include <openssl/rand.h>
#else
# include "magic.h"
#endif
/* address of server discovered by pam_sm_authenticate */
static tacplus_server_t active_server;
struct addrinfo active_addrinfo;
struct sockaddr active_sockaddr;
char active_key[TAC_SECRET_MAX_LEN+1];
/* accounting task identifier */
static short int task_id = 0;
/* copy a server's information into active_server */
static void set_active_server (const tacplus_server_t *tac_svr)
{
active_addrinfo.ai_addr = &active_sockaddr;
tac_copy_addr_info (&active_addrinfo, tac_svr->addr);
strncpy (active_key, tac_svr->key ? tac_svr->key : "", TAC_SECRET_MAX_LEN-1);
active_server.addr = &active_addrinfo;
active_server.key = active_key;
}
/* Helper functions */
int _pam_send_account(int tac_fd, int type, const char *user, char *tty,
char *r_addr, char *cmd) {
char buf[64];
struct tac_attrib *attr;
int retval;
attr = (struct tac_attrib *) xcalloc(1, sizeof(struct tac_attrib));
sprintf(buf, "%lu", (unsigned long) time(NULL));
if (type == TAC_PLUS_ACCT_FLAG_START) {
tac_add_attrib(&attr, "start_time", buf);
} else if (type == TAC_PLUS_ACCT_FLAG_STOP) {
tac_add_attrib(&attr, "stop_time", buf);
}
sprintf(buf, "%hu", task_id);
tac_add_attrib(&attr, "task_id", buf);
tac_add_attrib(&attr, "service", tac_service);
if (tac_protocol[0] != '\0')
tac_add_attrib(&attr, "protocol", tac_protocol);
if (cmd != NULL) {
tac_add_attrib(&attr, "cmd", cmd);
}
retval = tac_acct_send(tac_fd, type, user, tty, r_addr, attr);
/* this is no longer needed */
tac_free_attrib(&attr);
if (retval < 0) {
_pam_log(LOG_WARNING, "%s: send %s accounting failed (task %hu)",
__FUNCTION__, tac_acct_flag2str(type), task_id);
close(tac_fd);
return -1;
}
struct areply re;
if (tac_acct_read(tac_fd, &re) != TAC_PLUS_ACCT_STATUS_SUCCESS) {
_pam_log(LOG_WARNING, "%s: accounting %s failed (task %hu)",
__FUNCTION__, tac_acct_flag2str(type), task_id);
if (re.msg != NULL)
free(re.msg);
close(tac_fd);
return -1;
}
if (re.msg != NULL)
free(re.msg);
close(tac_fd);
return 0;
}
int _pam_account(pam_handle_t *pamh, int argc, const char **argv, int type,
char *cmd) {
int retval;
static int ctrl;
char *user = NULL;
char *tty = NULL;
char *r_addr = NULL;
char *typemsg;
int status = PAM_SESSION_ERR;
int srv_i, tac_fd;
typemsg = tac_acct_flag2str(type);
ctrl = _pam_parse(argc, argv);
if (ctrl & PAM_TAC_DEBUG) {
syslog(LOG_DEBUG, "%s: [%s] called (pam_tacplus v%u.%u.%u)",
__FUNCTION__, typemsg, PAM_TAC_VMAJ, PAM_TAC_VMIN,
PAM_TAC_VPAT);
syslog(LOG_DEBUG, "%s: tac_srv_no=%d", __FUNCTION__, tac_srv_no);
}
if ((user = _pam_get_user(pamh)) == NULL)
return PAM_USER_UNKNOWN;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: username [%s] obtained", __FUNCTION__, user);
tty = _pam_get_terminal(pamh);
if (!strncmp(tty, "/dev/", 5))
tty += 5;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: tty [%s] obtained", __FUNCTION__, tty);
r_addr = _pam_get_rhost(pamh);
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: rhost [%s] obtained", __FUNCTION__, r_addr);
/* checks for specific data required by TACACS+, which should
be supplied in command line */
if (*tac_service == '\0') {
_pam_log(LOG_ERR, "ACC: TACACS+ service type not configured");
return PAM_AUTH_ERR;
}
if (*tac_protocol == '\0') {
_pam_log(LOG_ERR,
"ACC: TACACS+ protocol type not configured (IGNORED)");
}
/* when this module is called from within pppd or other
application dealing with serial lines, it is likely
that we will get hit with signal caused by modem hangup;
this is important only for STOP packets, it's relatively
rare that modem hangs up on accounting start */
if (type == TAC_PLUS_ACCT_FLAG_STOP) {
signal(SIGALRM, SIG_IGN);
signal(SIGCHLD, SIG_IGN);
signal(SIGHUP, SIG_IGN);
}
status = PAM_SESSION_ERR;
for (srv_i = 0; srv_i < tac_srv_no; srv_i++) {
tac_fd = tac_connect_single(tac_srv[srv_i].addr, tac_srv[srv_i].key,
NULL, tac_timeout);
if (tac_fd < 0) {
_pam_log(LOG_WARNING, "%s: error sending %s (fd)", __FUNCTION__,
typemsg);
continue;
}
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: connected with fd=%d (srv %d)", __FUNCTION__,
tac_fd, srv_i);
retval = _pam_send_account(tac_fd, type, user, tty, r_addr, cmd);
if (retval < 0) {
_pam_log(LOG_WARNING, "%s: error sending %s (acct)", __FUNCTION__,
typemsg);
} else {
status = PAM_SUCCESS;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: [%s] for [%s] sent", __FUNCTION__,
typemsg, user);
}
close(tac_fd);
if ((status == PAM_SUCCESS) && !(ctrl & PAM_TAC_ACCT)) {
/* do not send acct start/stop packets to _all_ servers */
break;
}
}
if (type == TAC_PLUS_ACCT_FLAG_STOP) {
signal(SIGALRM, SIG_DFL);
signal(SIGCHLD, SIG_DFL);
signal(SIGHUP, SIG_DFL);
}
return status;
}
/* Main PAM functions */
/* authenticates user on remote TACACS+ server
* returns PAM_SUCCESS if the supplied username and password
* pair is valid
*/
PAM_EXTERN
int pam_sm_authenticate(pam_handle_t * pamh, int flags, int argc,
const char **argv) {
int ctrl, retval;
char *user;
char *pass;
char *tty;
char *r_addr;
int srv_i;
int tac_fd, status, msg, communicating;
user = pass = tty = r_addr = NULL;
ctrl = _pam_parse(argc, argv);
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: called (pam_tacplus v%u.%u.%u)", __FUNCTION__,
PAM_TAC_VMAJ, PAM_TAC_VMIN, PAM_TAC_VPAT);
if ((user = _pam_get_user(pamh)) == NULL)
return PAM_USER_UNKNOWN;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: user [%s] obtained", __FUNCTION__, user);
retval = tacacs_get_password(pamh, flags, ctrl, &pass);
if (retval != PAM_SUCCESS || pass == NULL || *pass == '\0') {
_pam_log(LOG_ERR, "unable to obtain password");
free(pass);
return PAM_CRED_INSUFFICIENT;
}
retval = pam_set_item(pamh, PAM_AUTHTOK, pass);
if (retval != PAM_SUCCESS) {
_pam_log(LOG_ERR, "unable to set password");
free(pass);
return PAM_CRED_INSUFFICIENT;
}
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: password obtained", __FUNCTION__);
tty = _pam_get_terminal(pamh);
if (!strncmp(tty, "/dev/", 5))
tty += 5;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: tty [%s] obtained", __FUNCTION__, tty);
r_addr = _pam_get_rhost(pamh);
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: rhost [%s] obtained", __FUNCTION__, r_addr);
status = PAM_AUTHINFO_UNAVAIL;
for (srv_i = 0; srv_i < tac_srv_no; srv_i++) {
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: trying srv %d", __FUNCTION__, srv_i);
tac_fd = tac_connect_single(tac_srv[srv_i].addr, tac_srv[srv_i].key,
NULL, tac_timeout);
if (tac_fd < 0) {
_pam_log(LOG_ERR, "connection failed srv %d: %m", srv_i);
active_server.addr = NULL;
continue;
}
if (tac_authen_send(tac_fd, user, pass, tty, r_addr,
TAC_PLUS_AUTHEN_LOGIN) < 0) {
close(tac_fd);
_pam_log(LOG_ERR, "error sending auth req to TACACS+ server");
active_server.addr = NULL;
continue;
}
communicating = 1;
while (communicating) {
struct areply re = { .attr = NULL, .msg = NULL, .status = 0,
.flags = 0 };
struct pam_message conv_msg = { .msg_style = 0, .msg = NULL };
struct pam_response *resp = NULL;
msg = tac_authen_read(tac_fd, &re);
if (NULL != re.msg) {
conv_msg.msg = re.msg;
}
/* talk the protocol */
switch (msg) {
case TAC_PLUS_AUTHEN_STATUS_PASS:
/* success */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG,
"tacacs status: TAC_PLUS_AUTHEN_STATUS_PASS");
if (NULL != conv_msg.msg) {
conv_msg.msg_style = PAM_TEXT_INFO;
retval = converse(pamh, 1, &conv_msg, &resp);
if (PAM_SUCCESS == retval) {
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "send msg=\"%s\"", conv_msg.msg);
} else {
_pam_log(LOG_WARNING,
"%s: error sending msg=\"%s\", retval=%d",
__FUNCTION__, conv_msg.msg, retval);
}
}
status = PAM_SUCCESS;
communicating = 0;
set_active_server(&tac_srv[srv_i]);
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: active srv %d", __FUNCTION__, srv_i);
break;
case TAC_PLUS_AUTHEN_STATUS_FAIL:
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG,
"tacacs status: TAC_PLUS_AUTHEN_STATUS_FAIL");
if (NULL != conv_msg.msg) {
conv_msg.msg_style = PAM_ERROR_MSG;
retval = converse(pamh, 1, &conv_msg, &resp);
if (PAM_SUCCESS == retval) {
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "send msg=\"%s\"", conv_msg.msg);
} else {
_pam_log(LOG_WARNING,
"%s: error sending msg=\"%s\", retval=%d",
__FUNCTION__, conv_msg.msg, retval);
}
}
status = PAM_AUTH_ERR;
communicating = 0;
_pam_log(LOG_ERR, "auth failed: %d", msg);
break;
case TAC_PLUS_AUTHEN_STATUS_GETDATA:
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG,
"tacacs status: TAC_PLUS_AUTHEN_STATUS_GETDATA");
if (NULL != conv_msg.msg) {
int echo_off = (0x1 == (re.flags & 0x1));
conv_msg.msg_style =
echo_off ? PAM_PROMPT_ECHO_OFF : PAM_PROMPT_ECHO_ON;
retval = converse(pamh, 1, &conv_msg, &resp);
if (PAM_SUCCESS == retval) {
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "sent msg=\"%s\", resp=\"%s\"",
conv_msg.msg, resp->resp);
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "%s: calling tac_cont_send",
__FUNCTION__);
if (0
> tac_cont_send_seq(tac_fd, resp->resp,
re.seq_no + 1)) {
_pam_log(LOG_ERR,
"error sending continue req to TACACS+ server");
status = PAM_AUTH_ERR;
communicating = 0;
}
} else {
_pam_log(LOG_WARNING,
"%s: error sending msg=\"%s\", retval=%d (%s)",
__FUNCTION__, conv_msg.msg, retval,
pam_strerror(pamh, retval));
status = PAM_AUTH_ERR;
communicating = 0;
}
} else {
syslog(LOG_ERR,
"GETDATA response with no message, returning PAM_AUTH_ERR");
status = PAM_AUTH_ERR;
communicating = 0;
}
break;
case TAC_PLUS_AUTHEN_STATUS_GETUSER:
/* not implemented */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG,
"tacacs status: TAC_PLUS_AUTHEN_STATUS_GETUSER");
communicating = 0;
break;
case TAC_PLUS_AUTHEN_STATUS_GETPASS:
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG,
"tacacs status: TAC_PLUS_AUTHEN_STATUS_GETPASS");
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: tac_cont_send called", __FUNCTION__);
if (tac_cont_send(tac_fd, pass) < 0) {
_pam_log(LOG_ERR,
"error sending continue req to TACACS+ server");
communicating = 0;
}
/* continue the while loop; go read tac response */
break;
case TAC_PLUS_AUTHEN_STATUS_RESTART:
/* try it again */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG,
"tacacs status: TAC_PLUS_AUTHEN_STATUS_RESTART");
/*
* not implemented
* WdJ: I *think* you can just do tac_authen_send(user, pass) again
* but I'm not sure
*/
communicating = 0;
break;
case TAC_PLUS_AUTHEN_STATUS_ERROR:
/* server has problems */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG,
"tacacs status: TAC_PLUS_AUTHEN_STATUS_ERROR");
communicating = 0;
break;
case TAC_PLUS_AUTHEN_STATUS_FOLLOW:
/* server tells to try a different server address */
/* not implemented */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG,
"tacacs status: TAC_PLUS_AUTHEN_STATUS_FOLLOW");
communicating = 0;
break;
default:
if (msg < 0) {
/* connection error */
communicating = 0;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG,
"error communicating with tacacs server");
break;
}
/* unknown response code */
communicating = 0;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "tacacs status: unknown response 0x%02x",
msg);
}
if (NULL != resp) {
free(resp->resp);
free(resp);
}
free(re.msg);
} /* end while(communicating) */
close(tac_fd);
if (status == PAM_SUCCESS || status == PAM_AUTH_ERR)
break;
}
if (status != PAM_SUCCESS && status != PAM_AUTH_ERR)
_pam_log(LOG_ERR, "no more servers to connect");
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: exit with pam status: %d", __FUNCTION__, status);
if (NULL != pass) {
bzero(pass, strlen(pass));
free(pass);
pass = NULL;
}
return status;
} /* pam_sm_authenticate */
/* no-op function to satisfy PAM authentication module */
PAM_EXTERN
int pam_sm_setcred(pam_handle_t * pamh, int flags, int argc, const char **argv) {
int ctrl = _pam_parse(argc, argv);
pamh = pamh;
flags = flags; /* unused */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: called (pam_tacplus v%u.%u.%u)", __FUNCTION__,
PAM_TAC_VMAJ, PAM_TAC_VMIN, PAM_TAC_VPAT);
return PAM_SUCCESS;
} /* pam_sm_setcred */
/* authorizes user on remote TACACS+ server, i.e. checks
* his permission to access requested service
* returns PAM_SUCCESS if the service is allowed
*/
PAM_EXTERN
int pam_sm_acct_mgmt(pam_handle_t * pamh, int flags, int argc,
const char **argv) {
int retval, ctrl, status = PAM_AUTH_ERR;
char *user;
char *tty;
char *r_addr;
struct areply arep;
struct tac_attrib *attr = NULL;
int tac_fd;
flags = flags; /* unused */
user = tty = r_addr = NULL;
memset(&arep, 0, sizeof(arep));
/* this also obtains service name for authorization
this should be normally performed by pam_get_item(PAM_SERVICE)
but since PAM service names are incompatible TACACS+
we have to pass it via command line argument until a better
solution is found ;) */
ctrl = _pam_parse(argc, argv);
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: called (pam_tacplus v%u.%u.%u)", __FUNCTION__,
PAM_TAC_VMAJ, PAM_TAC_VMIN, PAM_TAC_VPAT);
if ((user = _pam_get_user(pamh)) == NULL)
return PAM_USER_UNKNOWN;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: username obtained [%s]", __FUNCTION__, user);
tty = _pam_get_terminal(pamh);
if (!strncmp(tty, "/dev/", 5))
tty += 5;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: tty obtained [%s]", __FUNCTION__, tty);
r_addr = _pam_get_rhost(pamh);
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: rhost obtained [%s]", __FUNCTION__, r_addr);
/* checks if user has been successfully authenticated
by TACACS+; we cannot solely authorize user if it hasn't
been authenticated or has been authenticated by method other
than TACACS+ */
if (active_server.addr == NULL) {
_pam_log(LOG_ERR, "user not authenticated by TACACS+");
return PAM_AUTH_ERR;
}
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: active server is [%s]", __FUNCTION__,
tac_ntop(active_server.addr->ai_addr));
/* checks for specific data required by TACACS+, which should
be supplied in command line */
if (!*tac_service) {
_pam_log(LOG_ERR, "SM: TACACS+ service type not configured");
return PAM_AUTH_ERR;
}
if (!*tac_protocol) {
_pam_log(LOG_ERR, "SM: TACACS+ protocol type not configured (IGNORED)");
}
tac_add_attrib(&attr, "service", tac_service);
if (tac_protocol[0] != '\0')
tac_add_attrib(&attr, "protocol", tac_protocol);
tac_fd = tac_connect_single(active_server.addr, active_server.key, NULL,
tac_timeout);
if (tac_fd < 0) {
_pam_log(LOG_ERR, "TACACS+ server unavailable");
if (arep.msg != NULL)
free(arep.msg);
return PAM_AUTH_ERR;
}
retval = tac_author_send(tac_fd, user, tty, r_addr, attr);
tac_free_attrib(&attr);
if (retval < 0) {
_pam_log(LOG_ERR, "error getting authorization");
if (arep.msg != NULL)
free(arep.msg);
close(tac_fd);
active_server.addr = NULL;
return PAM_AUTH_ERR;
}
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: sent authorization request", __FUNCTION__);
tac_author_read(tac_fd, &arep);
if (arep.status != AUTHOR_STATUS_PASS_ADD
&& arep.status != AUTHOR_STATUS_PASS_REPL) {
_pam_log(LOG_ERR, "TACACS+ authorisation failed for [%s]", user);
if (arep.msg != NULL)
free(arep.msg);
close(tac_fd);
return PAM_PERM_DENIED;
}
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: user [%s] successfully authorized", __FUNCTION__,
user);
status = PAM_SUCCESS;
attr = arep.attr;
while (attr != NULL) {
size_t len = strcspn(attr->attr, "=*");
if (len < attr->attr_len) {
char avpair[attr->attr_len+1];
bcopy(attr->attr, avpair, attr->attr_len+1); /* Also copy terminating NUL */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: returned attribute `%s' from server",
__FUNCTION__, avpair);
avpair[len] = '='; // replace '*' by '='
size_t i;
for (i = 0; i < len; i++) {
avpair[i] = toupper(avpair[i]);
if (avpair[i] == '-')
avpair[i] = '_';
}
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: setting PAM environment `%s'",
__FUNCTION__, avpair);
/* make returned attributes available for other PAM modules via PAM environment */
if (pam_putenv(pamh, avpair) != PAM_SUCCESS)
syslog(LOG_WARNING, "%s: unable to set PAM environment",
__FUNCTION__);
} else {
syslog(LOG_WARNING, "%s: invalid attribute `%s', no separator",
__FUNCTION__, attr->attr);
}
attr = attr->next;
}
/* free returned attributes */
if (arep.attr != NULL)
tac_free_attrib(&arep.attr);
if (arep.msg != NULL)
free(arep.msg);
close(tac_fd);
return status;
} /* pam_sm_acct_mgmt */
/* sends START accounting request to the remote TACACS+ server
* returns PAM error only if the request was refused or there
* were problems connection to the server
*/
/* accounting packets may be directed to any TACACS+ server,
* independent from those used for authentication and authorization;
* it may be also directed to all specified servers
*/
PAM_EXTERN
int pam_sm_open_session(pam_handle_t * pamh, int flags, int argc,
const char **argv) {
#if defined(HAVE_OPENSSL_RAND_H) && defined(HAVE_LIBCRYPTO)
RAND_pseudo_bytes((unsigned char *) &task_id, sizeof(task_id));
#else
task_id=(short int) magic();
#endif
flags = flags; /* unused */
return _pam_account(pamh, argc, argv, TAC_PLUS_ACCT_FLAG_START, NULL);
} /* pam_sm_open_session */
/* sends STOP accounting request to the remote TACACS+ server
* returns PAM error only if the request was refused or there
* were problems connection to the server
*/
PAM_EXTERN
int pam_sm_close_session(pam_handle_t * pamh, int flags, int argc,
const char **argv) {
flags = flags; /* unused */
return _pam_account(pamh, argc, argv, TAC_PLUS_ACCT_FLAG_STOP, NULL);
} /* pam_sm_close_session */
#ifdef PAM_SM_PASSWORD
/* no-op function for future use */
PAM_EXTERN
int pam_sm_chauthtok(pam_handle_t * pamh, int flags, int argc,
const char **argv) {
int ctrl, retval;
char *user;
char *pass;
char *tty;
char *r_addr;
const void *pam_pass = NULL;
int srv_i;
int tac_fd, status, msg, communicating;
user = pass = tty = r_addr = NULL;
ctrl = _pam_parse(argc, argv);
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: called (pam_tacplus v%u.%u.%u)", __FUNCTION__,
PAM_TAC_VMAJ, PAM_TAC_VMIN, PAM_TAC_VPAT);
syslog(LOG_DEBUG, "%s(flags=%d, argc=%d)", __func__, flags, argc);
if ((pam_get_item(pamh, PAM_OLDAUTHTOK, &pam_pass) == PAM_SUCCESS)
&& (pam_pass != NULL)) {
if ((pass = strdup(pam_pass)) == NULL)
return PAM_BUF_ERR;
} else {
pass = strdup("");
}
if ((user = _pam_get_user(pamh)) == NULL) {
if (pass) {
free(pass);
}
return PAM_USER_UNKNOWN;
}
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: user [%s] obtained", __FUNCTION__, user);
tty = _pam_get_terminal(pamh);
if (!strncmp(tty, "/dev/", 5))
tty += 5;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: tty [%s] obtained", __FUNCTION__, tty);
r_addr = _pam_get_rhost(pamh);
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: rhost [%s] obtained", __FUNCTION__, r_addr);
if (PAM_SILENT == (flags & PAM_SILENT)) {
status = PAM_AUTHTOK_ERR;
goto finish;
}
status = PAM_TRY_AGAIN;
for (srv_i = 0; srv_i < tac_srv_no; srv_i++) {
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: trying srv %d", __FUNCTION__, srv_i);
tac_fd = tac_connect_single(tac_srv[srv_i].addr, tac_srv[srv_i].key,
NULL, tac_timeout);
if (tac_fd < 0) {
_pam_log(LOG_ERR, "connection failed srv %d: %m", srv_i);
continue;
}
if (PAM_PRELIM_CHECK == (flags & PAM_PRELIM_CHECK)) {
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "%s: finishing PAM_PRELIM_CHECK with srv %d",
__FUNCTION__, srv_i);
close(tac_fd);
status = PAM_SUCCESS;
goto finish;
}
if (tac_authen_send(tac_fd, user, "", tty, r_addr,
TAC_PLUS_AUTHEN_CHPASS) < 0) {
close(tac_fd);
_pam_log(LOG_ERR, "error sending auth req to TACACS+ server");
continue;
}
communicating = 1;
while (communicating) {
struct areply re = { .attr = NULL, .msg = NULL, .status = 0,
.flags = 0 };
struct pam_message conv_msg = { .msg_style = 0, .msg = NULL };
struct pam_response *resp = NULL;
msg = tac_authen_read(tac_fd, &re);
if (NULL != re.msg) {
conv_msg.msg = re.msg;
}
/* talk the protocol */
switch (msg) {
case TAC_PLUS_AUTHEN_STATUS_PASS:
/* success */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG,
"tacacs status: TAC_PLUS_AUTHEN_STATUS_PASS");
if (NULL != conv_msg.msg) {
conv_msg.msg_style = PAM_TEXT_INFO;
retval = converse(pamh, 1, &conv_msg, &resp);
if (PAM_SUCCESS == retval) {
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "send msg=\"%s\"", conv_msg.msg);
} else {
_pam_log(LOG_WARNING,
"%s: error sending msg=\"%s\", retval=%d",
__FUNCTION__, conv_msg.msg, retval);
}
}
status = PAM_SUCCESS;
communicating = 0;
set_active_server(&tac_srv[srv_i]);
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: active srv %d", __FUNCTION__, srv_i);
break;
case TAC_PLUS_AUTHEN_STATUS_FAIL:
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG,
"tacacs status: TAC_PLUS_AUTHEN_STATUS_FAIL");
if (NULL != conv_msg.msg) {
conv_msg.msg_style = PAM_ERROR_MSG;
retval = converse(pamh, 1, &conv_msg, &resp);
if (PAM_SUCCESS == retval) {
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "send msg=\"%s\"", conv_msg.msg);
} else {
_pam_log(LOG_WARNING,
"%s: error sending msg=\"%s\", retval=%d",
__FUNCTION__, conv_msg.msg, retval);
}
}
status = PAM_AUTHTOK_ERR;
communicating = 0;
_pam_log(LOG_ERR, "chauthtok failed: %d", msg);
break;
case TAC_PLUS_AUTHEN_STATUS_GETDATA:
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG,
"tacacs status: TAC_PLUS_AUTHEN_STATUS_GETDATA");
if (NULL != conv_msg.msg) {
int echo_off = (0x1 == (re.flags & 0x1));
conv_msg.msg_style =
echo_off ? PAM_PROMPT_ECHO_OFF : PAM_PROMPT_ECHO_ON;
retval = converse(pamh, 1, &conv_msg, &resp);
if (PAM_SUCCESS == retval) {
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "sent msg=\"%s\", resp=\"%s\"",
conv_msg.msg, resp->resp);
if (PAM_TAC_DEBUG == (ctrl & PAM_TAC_DEBUG))
syslog(LOG_DEBUG, "%s: calling tac_cont_send",
__FUNCTION__);
if (0
> tac_cont_send_seq(tac_fd, resp->resp,
re.seq_no + 1)) {
_pam_log(LOG_ERR,
"error sending continue req to TACACS+ server");
communicating = 0;
}
} else {
_pam_log(LOG_WARNING,
"%s: error sending msg=\"%s\", retval=%d",
__FUNCTION__, conv_msg.msg, retval);
communicating = 0;
}
} else {
syslog(LOG_ERR,
"GETDATA response with no message, returning PAM_TRY_AGAIN");
communicating = 0;
}
break;
case TAC_PLUS_AUTHEN_STATUS_GETUSER:
/* not implemented */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG,
"tacacs status: TAC_PLUS_AUTHEN_STATUS_GETUSER");
communicating = 0;
break;
case TAC_PLUS_AUTHEN_STATUS_GETPASS:
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG,
"tacacs status: TAC_PLUS_AUTHEN_STATUS_GETPASS");
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG, "%s: calling tac_cont_send",
__FUNCTION__);
if (tac_cont_send(tac_fd, pass) < 0) {
_pam_log(LOG_ERR,
"error sending continue req to TACACS+ server");
communicating = 0;
break;
}
/* continue the while loop; go read tac response */
break;
case TAC_PLUS_AUTHEN_STATUS_RESTART:
/* try it again */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG,
"tacacs status: TAC_PLUS_AUTHEN_STATUS_RESTART");
/*
* not implemented
* WdJ: I *think* you can just do tac_authen_send(user, pass) again
* but I'm not sure
*/
communicating = 0;
break;
case TAC_PLUS_AUTHEN_STATUS_ERROR:
/* server has problems */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG,
"tacacs status: TAC_PLUS_AUTHEN_STATUS_ERROR");
communicating = 0;
break;
case TAC_PLUS_AUTHEN_STATUS_FOLLOW:
/* server tells to try a different server address */
/* not implemented */
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG,
"tacacs status: TAC_PLUS_AUTHEN_STATUS_FOLLOW");
communicating = 0;
break;
default:
if (msg < 0) {
/* connection error */
communicating = 0;
if (ctrl & PAM_TAC_DEBUG)
syslog(LOG_DEBUG,
"error communicating with tacacs server");
break;
}
/* unknown response code */