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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
|
/*-
* Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if 0
static char copyright[] =
"@(#) Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994\n\
The Regents of the University of California. All rights reserved.\n";
#endif
#ifndef lint
#if 0
static char sccsid[] = "@(#)login.c 8.4 (Berkeley) 4/2/94";
#endif
static const char rcsid[] =
"$FreeBSD$
#endif /* not lint */
/*
* login [ name ]
* login -h hostname (for telnetd, etc.)
* login -f name (for pre-authenticated login: datakit, xterm, etc.)
*/
#include <sys/copyright.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/file.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <err.h>
#include <errno.h>
#include <grp.h>
#include <libutil.h>
#include <login_cap.h>
#include <netdb.h>
#include <pwd.h>
#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <ttyent.h>
#include <unistd.h>
#include <utmp.h>
#ifdef USE_PAM
#include <security/pam_appl.h>
#include <security/pam_misc.h>
#include <sys/wait.h>
#endif /* USE_PAM */
#include "pathnames.h"
/* wrapper for KAME-special getnameinfo() */
#ifndef NI_WITHSCOPEID
#define NI_WITHSCOPEID 0
#endif
void badlogin __P((char *));
void checknologin __P((void));
void dolastlog __P((int));
void getloginname __P((void));
void motd __P((char *));
int rootterm __P((char *));
void sigint __P((int));
void sleepexit __P((int));
void refused __P((char *,char *,int));
char *stypeof __P((char *));
void timedout __P((int));
int login_access __P((char *, char *));
void login_fbtab __P((char *, uid_t, gid_t));
#ifdef USE_PAM
static int auth_pam __P((void));
static int export_pam_environment __P((void));
static int ok_to_export __P((const char *));
static pam_handle_t *pamh = NULL;
static char **environ_pam;
#define PAM_END { \
if ((e = pam_setcred(pamh, PAM_DELETE_CRED)) != PAM_SUCCESS) \
syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e)); \
if ((e = pam_close_session(pamh,0)) != PAM_SUCCESS) \
syslog(LOG_ERR, "pam_close_session: %s", pam_strerror(pamh, e)); \
if ((e = pam_end(pamh, e)) != PAM_SUCCESS) \
syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e)); \
}
#endif
static int auth_traditional __P((void));
extern void login __P((struct utmp *));
static void usage __P((void));
#define TTYGRPNAME "tty" /* name of group to own ttys */
#define DEFAULT_BACKOFF 3
#define DEFAULT_RETRIES 10
#define DEFAULT_PROMPT "login: "
#define DEFAULT_PASSWD_PROMPT "Password:"
/*
* This bounds the time given to login. Not a define so it can
* be patched on machines where it's too small.
*/
u_int timeout = 300;
/* Buffer for signal handling of timeout */
jmp_buf timeout_buf;
struct passwd *pwd;
int failures;
char *term, *envinit[1], *hostname, *passwd_prompt, *prompt, *tty, *username;
char full_hostname[MAXHOSTNAMELEN];
int
main(argc, argv)
int argc;
char *argv[];
{
extern char **environ;
struct group *gr;
struct stat st;
struct timeval tp;
struct utmp utmp;
int rootok, retries, backoff;
int ask, ch, cnt, fflag, hflag, pflag, quietlog, rootlogin, rval;
int changepass;
time_t warntime;
uid_t uid, euid;
gid_t egid;
char *p, *ttyn;
char tbuf[MAXPATHLEN + 2];
char tname[sizeof(_PATH_TTY) + 10];
char *shell = NULL;
login_cap_t *lc = NULL;
#ifdef USE_PAM
pid_t pid;
int e;
#endif /* USE_PAM */
(void)signal(SIGQUIT, SIG_IGN);
(void)signal(SIGINT, SIG_IGN);
(void)signal(SIGHUP, SIG_IGN);
if (setjmp(timeout_buf)) {
if (failures)
badlogin(tbuf);
(void)fprintf(stderr, "Login timed out after %d seconds\n",
timeout);
exit(0);
}
(void)signal(SIGALRM, timedout);
(void)alarm(timeout);
(void)setpriority(PRIO_PROCESS, 0, 0);
openlog("login", LOG_ODELAY, LOG_AUTH);
/*
* -p is used by getty to tell login not to destroy the environment
* -f is used to skip a second login authentication
* -h is used by other servers to pass the name of the remote
* host to login so that it may be placed in utmp and wtmp
*/
*full_hostname = '\0';
term = NULL;
fflag = hflag = pflag = 0;
uid = getuid();
euid = geteuid();
egid = getegid();
while ((ch = getopt(argc, argv, "fh:p")) != -1)
switch (ch) {
case 'f':
fflag = 1;
break;
case 'h':
if (uid)
errx(1, "-h option: %s", strerror(EPERM));
hflag = 1;
if (strlcpy(full_hostname, optarg,
sizeof(full_hostname)) >= sizeof(full_hostname))
errx(1, "-h option: %s: exceeds maximum "
"hostname size", optarg);
trimdomain(optarg, UT_HOSTSIZE);
if (strlen(optarg) > UT_HOSTSIZE) {
struct addrinfo hints, *res;
int ga_err;
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
ga_err = getaddrinfo(optarg, NULL, &hints,
&res);
if (ga_err == 0) {
char hostbuf[MAXHOSTNAMELEN];
getnameinfo(res->ai_addr,
res->ai_addrlen,
hostbuf,
sizeof(hostbuf), NULL, 0,
NI_NUMERICHOST|
NI_WITHSCOPEID);
optarg = strdup(hostbuf);
if (optarg == NULL) {
syslog(LOG_NOTICE,
"strdup(): %m");
sleepexit(1);
}
} else
optarg = "invalid hostname";
if (res != NULL)
freeaddrinfo(res);
}
hostname = optarg;
break;
case 'p':
pflag = 1;
break;
case '?':
default:
if (!uid)
syslog(LOG_ERR, "invalid flag %c", ch);
usage();
}
argc -= optind;
argv += optind;
if (*argv) {
username = *argv;
ask = 0;
} else
ask = 1;
for (cnt = getdtablesize(); cnt > 2; cnt--)
(void)close(cnt);
ttyn = ttyname(STDIN_FILENO);
if (ttyn == NULL || *ttyn == '\0') {
(void)snprintf(tname, sizeof(tname), "%s??", _PATH_TTY);
ttyn = tname;
}
if ((tty = strrchr(ttyn, '/')) != NULL)
++tty;
else
tty = ttyn;
/*
* Get "login-retries" & "login-backoff" from default class
*/
lc = login_getclass(NULL);
prompt = login_getcapstr(lc, "prompt", DEFAULT_PROMPT, DEFAULT_PROMPT);
passwd_prompt = login_getcapstr(lc, "passwd_prompt",
DEFAULT_PASSWD_PROMPT, DEFAULT_PASSWD_PROMPT);
retries = login_getcapnum(lc, "login-retries", DEFAULT_RETRIES,
DEFAULT_RETRIES);
backoff = login_getcapnum(lc, "login-backoff", DEFAULT_BACKOFF,
DEFAULT_BACKOFF);
login_close(lc);
lc = NULL;
for (cnt = 0;; ask = 1) {
if (ask) {
fflag = 0;
getloginname();
}
rootlogin = 0;
rootok = rootterm(tty); /* Default (auth may change) */
if (strlen(username) > UT_NAMESIZE)
username[UT_NAMESIZE] = '\0';
/*
* Note if trying multiple user names; log failures for
* previous user name, but don't bother logging one failure
* for nonexistent name (mistyped username).
*/
if (failures && strcmp(tbuf, username)) {
if (failures > (pwd ? 0 : 1))
badlogin(tbuf);
}
(void)strlcpy(tbuf, username, sizeof(tbuf));
pwd = getpwnam(username);
/*
* if we have a valid account name, and it doesn't have a
* password, or the -f option was specified and the caller
* is root or the caller isn't changing their uid, don't
* authenticate.
*/
if (pwd != NULL) {
if (pwd->pw_uid == 0)
rootlogin = 1;
if (fflag && (uid == (uid_t)0 ||
uid == (uid_t)pwd->pw_uid)) {
/* already authenticated */
break;
} else if (pwd->pw_passwd[0] == '\0') {
if (!rootlogin || rootok) {
/* pretend password okay */
rval = 0;
goto ttycheck;
}
}
}
fflag = 0;
(void)setpriority(PRIO_PROCESS, 0, -4);
#ifdef USE_PAM
/*
* Try to authenticate using PAM. If a PAM system error
* occurs, perhaps because of a botched configuration,
* then fall back to using traditional Unix authentication.
*/
if ((rval = auth_pam()) == -1)
#endif /* USE_PAM */
rval = auth_traditional();
(void)setpriority(PRIO_PROCESS, 0, 0);
#ifdef USE_PAM
/*
* PAM authentication may have changed "pwd" to the
* entry for the template user. Check again to see if
* this is a root login after all.
*/
if (pwd != NULL && pwd->pw_uid == 0)
rootlogin = 1;
#endif /* USE_PAM */
ttycheck:
/*
* If trying to log in as root without Kerberos,
* but with insecure terminal, refuse the login attempt.
*/
if (pwd && !rval) {
if (rootlogin && !rootok)
refused(NULL, "NOROOT", 0);
else /* valid password & authenticated */
break;
}
(void)printf("Login incorrect\n");
failures++;
/*
* we allow up to 'retry' (10) tries,
* but after 'backoff' (3) we start backing off
*/
if (++cnt > backoff) {
if (cnt >= retries) {
badlogin(username);
sleepexit(1);
}
sleep((u_int)((cnt - backoff) * 5));
}
}
/* committed to login -- turn off timeout */
(void)alarm((u_int)0);
(void)signal(SIGHUP, SIG_DFL);
endpwent();
/*
* Establish the login class.
*/
lc = login_getpwclass(pwd);
/* if user not super-user, check for disabled logins */
if (!rootlogin)
auth_checknologin(lc);
quietlog = login_getcapbool(lc, "hushlogin", 0);
/*
* Switching needed for NFS with root access disabled.
*
* XXX: This change fails to modify the additional groups for the
* process, and as such, may restrict rights normally granted
* through those groups.
*/
(void)setegid(pwd->pw_gid);
(void)seteuid(rootlogin ? 0 : pwd->pw_uid);
if (!*pwd->pw_dir || chdir(pwd->pw_dir) < 0) {
if (login_getcapbool(lc, "requirehome", 0))
refused("Home directory not available", "HOMEDIR", 1);
if (chdir("/") < 0)
refused("Cannot find root directory", "ROOTDIR", 1);
if (!quietlog || *pwd->pw_dir)
printf("No home directory.\nLogging in with home = \"/\".\n");
pwd->pw_dir = "/";
}
(void)seteuid(euid);
(void)setegid(egid);
if (!quietlog)
quietlog = access(_PATH_HUSHLOGIN, F_OK) == 0;
if (pwd->pw_change || pwd->pw_expire)
(void)gettimeofday(&tp, (struct timezone *)NULL);
#define DEFAULT_WARN (2L * 7L * 86400L) /* Two weeks */
warntime = login_getcaptime(lc, "warnexpire", DEFAULT_WARN,
DEFAULT_WARN);
if (pwd->pw_expire) {
if (tp.tv_sec >= pwd->pw_expire) {
refused("Sorry -- your account has expired", "EXPIRED",
1);
} else if (pwd->pw_expire - tp.tv_sec < warntime && !quietlog)
(void)printf("Warning: your account expires on %s",
ctime(&pwd->pw_expire));
}
warntime = login_getcaptime(lc, "warnpassword", DEFAULT_WARN,
DEFAULT_WARN);
changepass = 0;
if (pwd->pw_change) {
if (tp.tv_sec >= pwd->pw_change) {
(void)printf("Sorry -- your password has expired.\n");
changepass = 1;
syslog(LOG_INFO, "%s Password expired - forcing change",
pwd->pw_name);
} else if (pwd->pw_change - tp.tv_sec < warntime && !quietlog)
(void)printf("Warning: your password expires on %s",
ctime(&pwd->pw_change));
}
if (lc != NULL) {
if (hostname) {
struct addrinfo hints, *res;
int ga_err;
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
ga_err = getaddrinfo(full_hostname, NULL, &hints,
&res);
if (ga_err == 0) {
char hostbuf[MAXHOSTNAMELEN];
getnameinfo(res->ai_addr, res->ai_addrlen,
hostbuf, sizeof(hostbuf), NULL, 0,
NI_NUMERICHOST|NI_WITHSCOPEID);
if ((optarg = strdup(hostbuf)) == NULL) {
syslog(LOG_NOTICE, "strdup(): %m");
sleepexit(1);
}
} else
optarg = NULL;
if (res != NULL)
freeaddrinfo(res);
if (!auth_hostok(lc, full_hostname, optarg))
refused("Permission denied", "HOST", 1);
}
if (!auth_ttyok(lc, tty))
refused("Permission denied", "TTY", 1);
if (!auth_timeok(lc, time(NULL)))
refused("Logins not available right now", "TIME", 1);
}
shell = login_getcapstr(lc, "shell", pwd->pw_shell, pwd->pw_shell);
if (*pwd->pw_shell == '\0')
pwd->pw_shell = _PATH_BSHELL;
if (*shell == '\0') /* Not overridden */
shell = pwd->pw_shell;
if ((shell = strdup(shell)) == NULL) {
syslog(LOG_NOTICE, "strdup(): %m");
sleepexit(1);
}
#ifdef LOGIN_ACCESS
if (login_access(pwd->pw_name, hostname ? full_hostname : tty) == 0)
refused("Permission denied", "ACCESS", 1);
#endif /* LOGIN_ACCESS */
/* Nothing else left to fail -- really log in. */
memset((void *)&utmp, 0, sizeof(utmp));
(void)time(&utmp.ut_time);
(void)strncpy(utmp.ut_name, username, sizeof(utmp.ut_name));
if (hostname)
(void)strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host));
(void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line));
login(&utmp);
dolastlog(quietlog);
/*
* Set device protections, depending on what terminal the
* user is logged in. This feature is used on Suns to give
* console users better privacy.
*/
login_fbtab(tty, pwd->pw_uid, pwd->pw_gid);
/*
* Clear flags of the tty. None should be set, and when the
* user sets them otherwise, this can cause the chown to fail.
* Since it isn't clear that flags are useful on character
* devices, we just clear them.
*/
if (chflags(ttyn, 0) && errno != EOPNOTSUPP)
syslog(LOG_ERR, "chmod(%s): %m", ttyn);
if (chown(ttyn, pwd->pw_uid,
(gr = getgrnam(TTYGRPNAME)) ? gr->gr_gid : pwd->pw_gid))
syslog(LOG_ERR, "chmod(%s): %m", ttyn);
/*
* Preserve TERM if it happens to be already set.
*/
if ((term = getenv("TERM")) != NULL) {
if ((term = strdup(term)) == NULL) {
syslog(LOG_NOTICE,
"strdup(): %m");
sleepexit(1);
}
}
/*
* Exclude cons/vt/ptys only, assume dialup otherwise
* TODO: Make dialup tty determination a library call
* for consistency (finger etc.)
*/
if (hostname==NULL && isdialuptty(tty))
syslog(LOG_INFO, "DIALUP %s, %s", tty, pwd->pw_name);
#ifdef LOGALL
/*
* Syslog each successful login, so we don't have to watch hundreds
* of wtmp or lastlogin files.
*/
if (hostname)
syslog(LOG_INFO, "login from %s on %s as %s",
full_hostname, tty, pwd->pw_name);
else
syslog(LOG_INFO, "login on %s as %s",
tty, pwd->pw_name);
#endif
/*
* If fflag is on, assume caller/authenticator has logged root login.
*/
if (rootlogin && fflag == 0)
{
if (hostname)
syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s FROM %s",
username, tty, full_hostname);
else
syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s",
username, tty);
}
/*
* Destroy environment unless user has requested its preservation.
* We need to do this before setusercontext() because that may
* set or reset some environment variables.
*/
if (!pflag)
environ = envinit;
/*
* PAM modules might add supplementary groups during pam_setcred().
*/
if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETGROUP) != 0) {
syslog(LOG_ERR, "setusercontext() failed - exiting");
exit(1);
}
#ifdef USE_PAM
if (pamh) {
if ((e = pam_open_session(pamh, 0)) != PAM_SUCCESS) {
syslog(LOG_ERR, "pam_open_session: %s",
pam_strerror(pamh, e));
} else if ((e = pam_setcred(pamh, PAM_ESTABLISH_CRED))
!= PAM_SUCCESS) {
syslog(LOG_ERR, "pam_setcred: %s",
pam_strerror(pamh, e));
}
/*
* Add any environmental variables that the
* PAM modules may have set.
* Call *after* opening session!
*/
if (pamh) {
environ_pam = pam_getenvlist(pamh);
if (environ_pam)
export_pam_environment();
}
/*
* We must fork() before setuid() because we need to call
* pam_close_session() as root.
*/
pid = fork();
if (pid < 0) {
err(1, "fork");
PAM_END;
exit(0);
} else if (pid) {
/* parent - wait for child to finish, then cleanup
session */
wait(NULL);
PAM_END;
exit(0);
} else {
if ((e = pam_end(pamh, PAM_DATA_SILENT)) != PAM_SUCCESS)
syslog(LOG_ERR, "pam_end: %s",
pam_strerror(pamh, e));
}
}
#endif /* USE_PAM */
/*
* We don't need to be root anymore, so
* set the user and session context
*/
if (setlogin(username) != 0) {
syslog(LOG_ERR, "setlogin(%s): %m - exiting", username);
exit(1);
}
if (setusercontext(lc, pwd, pwd->pw_uid,
LOGIN_SETALL & ~(LOGIN_SETLOGIN|LOGIN_SETGROUP)) != 0) {
syslog(LOG_ERR, "setusercontext() failed - exiting");
exit(1);
}
(void)setenv("SHELL", pwd->pw_shell, 1);
(void)setenv("HOME", pwd->pw_dir, 1);
if (term != NULL && *term != '\0')
(void)setenv("TERM", term, 1); /* Preset overrides */
else {
(void)setenv("TERM", stypeof(tty), 0); /* Fallback doesn't */
}
(void)setenv("LOGNAME", username, 1);
(void)setenv("USER", username, 1);
(void)setenv("PATH", rootlogin ? _PATH_STDPATH : _PATH_DEFPATH, 0);
if (!quietlog) {
char *cw;
cw = login_getcapstr(lc, "copyright", NULL, NULL);
if (cw != NULL && access(cw, F_OK) == 0)
motd(cw);
else
(void)printf("%s\n\t%s %s\n",
"Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994",
"The Regents of the University of California. ",
"All rights reserved.");
(void)printf("\n");
cw = login_getcapstr(lc, "welcome", NULL, NULL);
if (cw == NULL || access(cw, F_OK) != 0)
cw = _PATH_MOTDFILE;
motd(cw);
cw = getenv("MAIL"); /* $MAIL may have been set by class */
if (cw != NULL)
strlcpy(tbuf, cw, sizeof(tbuf));
else
snprintf(tbuf, sizeof(tbuf), "%s/%s", _PATH_MAILDIR,
pwd->pw_name);
if (stat(tbuf, &st) == 0 && st.st_size != 0)
(void)printf("You have %smail.\n",
(st.st_mtime > st.st_atime) ? "new " : "");
}
login_close(lc);
(void)signal(SIGALRM, SIG_DFL);
(void)signal(SIGQUIT, SIG_DFL);
(void)signal(SIGINT, SIG_DFL);
(void)signal(SIGTSTP, SIG_IGN);
/*
* Login shells have a leading '-' in front of argv[0]
*/
if (snprintf(tbuf, sizeof(tbuf), "-%s",
(p = strrchr(pwd->pw_shell, '/')) ? p + 1 : pwd->pw_shell) >=
sizeof(tbuf)) {
syslog(LOG_ERR, "user: %s: shell exceeds maximum pathname size",
username);
errx(1, "shell exceeds maximum pathname size");
}
execlp(shell, tbuf, (char *)0);
err(1, "%s", shell);
}
static int
auth_traditional()
{
int rval;
char *p;
char *ep;
char *salt;
rval = 1;
salt = pwd != NULL ? pwd->pw_passwd : "xx";
p = getpass(passwd_prompt);
ep = crypt(p, salt);
if (pwd) {
if (!p[0] && pwd->pw_passwd[0])
ep = ":";
if (strcmp(ep, pwd->pw_passwd) == 0)
rval = 0;
}
/* clear entered password */
memset(p, 0, strlen(p));
return rval;
}
#ifdef USE_PAM
/*
* Attempt to authenticate the user using PAM. Returns 0 if the user is
* authenticated, or 1 if not authenticated. If some sort of PAM system
* error occurs (e.g., the "/etc/pam.conf" file is missing) then this
* function returns -1. This can be used as an indication that we should
* fall back to a different authentication mechanism.
*/
static int
auth_pam()
{
const char *tmpl_user;
const void *item;
int rval;
int e;
static struct pam_conv conv = { misc_conv, NULL };
if ((e = pam_start("login", username, &conv, &pamh)) != PAM_SUCCESS) {
syslog(LOG_ERR, "pam_start: %s", pam_strerror(pamh, e));
return -1;
}
if ((e = pam_set_item(pamh, PAM_TTY, tty)) != PAM_SUCCESS) {
syslog(LOG_ERR, "pam_set_item(PAM_TTY): %s",
pam_strerror(pamh, e));
return -1;
}
if (hostname != NULL &&
(e = pam_set_item(pamh, PAM_RHOST, full_hostname)) != PAM_SUCCESS) {
syslog(LOG_ERR, "pam_set_item(PAM_RHOST): %s",
pam_strerror(pamh, e));
return -1;
}
e = pam_authenticate(pamh, 0);
switch (e) {
case PAM_SUCCESS:
/*
* With PAM we support the concept of a "template"
* user. The user enters a login name which is
* authenticated by PAM, usually via a remote service
* such as RADIUS or TACACS+. If authentication
* succeeds, a different but related "template" name
* is used for setting the credentials, shell, and
* home directory. The name the user enters need only
* exist on the remote authentication server, but the
* template name must be present in the local password
* database.
*
* This is supported by two various mechanisms in the
* individual modules. However, from the application's
* point of view, the template user is always passed
* back as a changed value of the PAM_USER item.
*/
if ((e = pam_get_item(pamh, PAM_USER, &item)) ==
PAM_SUCCESS) {
tmpl_user = (const char *) item;
if (strcmp(username, tmpl_user) != 0)
pwd = getpwnam(tmpl_user);
} else
syslog(LOG_ERR, "Couldn't get PAM_USER: %s",
pam_strerror(pamh, e));
rval = 0;
break;
case PAM_AUTH_ERR:
case PAM_USER_UNKNOWN:
case PAM_MAXTRIES:
rval = 1;
break;
default:
syslog(LOG_ERR, "pam_authenticate: %s", pam_strerror(pamh, e));
rval = -1;
break;
}
if (rval == 0) {
e = pam_acct_mgmt(pamh, 0);
if (e == PAM_NEW_AUTHTOK_REQD) {
e = pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
if (e != PAM_SUCCESS) {
syslog(LOG_ERR, "pam_chauthtok: %s",
pam_strerror(pamh, e));
rval = 1;
}
} else if (e != PAM_SUCCESS) {
rval = 1;
}
}
if (rval != 0) {
if ((e = pam_end(pamh, e)) != PAM_SUCCESS) {
syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
}
pamh = NULL;
}
return rval;
}
static int
export_pam_environment()
{
char **pp;
for (pp = environ_pam; *pp != NULL; pp++) {
if (ok_to_export(*pp))
(void) putenv(*pp);
free(*pp);
}
return PAM_SUCCESS;
}
/*
* Sanity checks on PAM environmental variables:
* - Make sure there is an '=' in the string.
* - Make sure the string doesn't run on too long.
* - Do not export certain variables. This list was taken from the
* Solaris pam_putenv(3) man page.
*/
static int
ok_to_export(s)
const char *s;
{
static const char *noexport[] = {
"SHELL", "HOME", "LOGNAME", "MAIL", "CDPATH",
"IFS", "PATH", NULL
};
const char **pp;
size_t n;
if (strlen(s) > 1024 || strchr(s, '=') == NULL)
return 0;
if (strncmp(s, "LD_", 3) == 0)
return 0;
for (pp = noexport; *pp != NULL; pp++) {
n = strlen(*pp);
if (s[n] == '=' && strncmp(s, *pp, n) == 0)
return 0;
}
return 1;
}
#endif /* USE_PAM */
static void
usage()
{
(void)fprintf(stderr, "usage: login [-fp] [-h hostname] [username]\n");
exit(1);
}
/*
* Allow for authentication style and/or kerberos instance
*/
#define NBUFSIZ UT_NAMESIZE + 64
void
getloginname()
{
int ch;
char *p;
static char nbuf[NBUFSIZ];
for (;;) {
(void)printf("%s", prompt);
for (p = nbuf; (ch = getchar()) != '\n'; ) {
if (ch == EOF) {
badlogin(username);
exit(0);
}
if (p < nbuf + (NBUFSIZ - 1))
*p++ = ch;
}
if (p > nbuf) {
if (nbuf[0] == '-')
(void)fprintf(stderr,
"login names may not start with '-'.\n");
else {
*p = '\0';
username = nbuf;
break;
}
}
}
}
int
rootterm(ttyn)
char *ttyn;
{
struct ttyent *t;
return ((t = getttynam(ttyn)) && t->ty_status & TTY_SECURE);
}
volatile int motdinterrupt;
void
sigint(signo)
int signo __unused;
{
motdinterrupt = 1;
}
void
motd(motdfile)
char *motdfile;
{
int fd, nchars;
sig_t oldint;
char tbuf[256];
if ((fd = open(motdfile, O_RDONLY, 0)) < 0)
return;
motdinterrupt = 0;
oldint = signal(SIGINT, sigint);
while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0 && !motdinterrupt)
(void)write(fileno(stdout), tbuf, nchars);
(void)signal(SIGINT, oldint);
(void)close(fd);
}
/* ARGSUSED */
void
timedout(signo)
int signo;
{
longjmp(timeout_buf, signo);
}
void
dolastlog(quiet)
int quiet;
{
struct lastlog ll;
int fd;
if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) {
(void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET);
if (!quiet) {
if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) &&
ll.ll_time != 0) {
(void)printf("Last login: %.*s ",
24-5, (char *)ctime(&ll.ll_time));
if (*ll.ll_host != '\0')
(void)printf("from %.*s\n",
(int)sizeof(ll.ll_host),
ll.ll_host);
else
(void)printf("on %.*s\n",
(int)sizeof(ll.ll_line),
ll.ll_line);
}
(void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET);
}
memset((void *)&ll, 0, sizeof(ll));
(void)time(&ll.ll_time);
(void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
if (hostname)
(void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host));
(void)write(fd, (char *)&ll, sizeof(ll));
(void)close(fd);
} else {
syslog(LOG_ERR, "cannot open %s: %m", _PATH_LASTLOG);
}
}
void
badlogin(name)
char *name;
{
if (failures == 0)
return;
if (hostname) {
syslog(LOG_NOTICE, "%d LOGIN FAILURE%s FROM %s",
failures, failures > 1 ? "S" : "", full_hostname);
syslog(LOG_AUTHPRIV|LOG_NOTICE,
"%d LOGIN FAILURE%s FROM %s, %s",
failures, failures > 1 ? "S" : "", full_hostname, name);
} else {
syslog(LOG_NOTICE, "%d LOGIN FAILURE%s ON %s",
failures, failures > 1 ? "S" : "", tty);
syslog(LOG_AUTHPRIV|LOG_NOTICE,
"%d LOGIN FAILURE%s ON %s, %s",
failures, failures > 1 ? "S" : "", tty, name);
}
failures = 0;
}
#undef UNKNOWN
#define UNKNOWN "su"
char *
stypeof(ttyid)
char *ttyid;
{
struct ttyent *t;
if (ttyid != NULL && *ttyid != '\0') {
t = getttynam(ttyid);
if (t != NULL && t->ty_type != NULL)
return (t->ty_type);
}
return (UNKNOWN);
}
void
refused(msg, rtype, lout)
char *msg;
char *rtype;
int lout;
{
if (msg != NULL)
printf("%s.\n", msg);
if (hostname)
syslog(LOG_NOTICE, "LOGIN %s REFUSED (%s) FROM %s ON TTY %s",
pwd->pw_name, rtype, full_hostname, tty);
else
syslog(LOG_NOTICE, "LOGIN %s REFUSED (%s) ON TTY %s",
pwd->pw_name, rtype, tty);
if (lout)
sleepexit(1);
}
void
sleepexit(eval)
int eval;
{
(void)sleep(5);
exit(eval);
}
|