summaryrefslogtreecommitdiff
path: root/source3/auth/pass_check.c
blob: 23ae4d0974546c5392316a7a93e60285813d366e (plain)
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
/* 
   Unix SMB/Netbios implementation.
   Version 1.9.
   Password checking
   Copyright (C) Andrew Tridgell 1992-1998
   
   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; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

/* this module is for checking a username/password against a system
   password database. The SMB encrypted password support is elsewhere */

#include "includes.h"

extern int DEBUGLEVEL;

/* these are kept here to keep the string_combinations function simple */
static char this_user[100]="";
static char this_salt[100]="";
static char this_crypted[100]="";


/****************************************************************************
update the enhanced security database. Only relevant for OSF1 at the moment.
****************************************************************************/
static void update_protected_database(char *user, BOOL result)
{
#ifdef OSF1_ENH_SEC
	struct pr_passwd *mypasswd;
	time_t starttime;

	mypasswd = getprpwnam (user);
	starttime = time (NULL);

	if (result)  {
		mypasswd->ufld.fd_slogin = starttime;
		mypasswd->ufld.fd_nlogins = 0;
      
		putprpwnam(user,mypasswd);
      	} else {
		mypasswd->ufld.fd_ulogin = starttime;
		mypasswd->ufld.fd_nlogins = mypasswd->ufld.fd_nlogins + 1;
		if (mypasswd->ufld.fd_max_tries != 0 && 
		    mypasswd->ufld.fd_nlogins > mypasswd->ufld.fd_max_tries) {
			mypasswd->uflg.fg_lock = 0;
			DEBUG(3,("Account %s is disabled\n", user));
		}
		putprpwnam(user ,mypasswd);
	}
#endif
}


#ifdef HAVE_PAM
/*******************************************************************
check on PAM authentication
********************************************************************/

/* We first need some helper functions */
#include <security/pam_appl.h>
/* Static variables used to communicate between the conversation function
 * and the server_login function
 */
static char *PAM_username;
static char *PAM_password;

/* PAM conversation function
 * Here we assume (for now, at least) that echo on means login name, and
 * echo off means password.
 */
static int PAM_conv (int num_msg,
                     const struct pam_message **msg,
                     struct pam_response **resp,
                     void *appdata_ptr) {
  int replies = 0;
  struct pam_response *reply = NULL;

  #define COPY_STRING(s) (s) ? strdup(s) : NULL

  reply = malloc(sizeof(struct pam_response) * num_msg);
  if (!reply) return PAM_CONV_ERR;

  for (replies = 0; replies < num_msg; replies++) {
    switch (msg[replies]->msg_style) {
      case PAM_PROMPT_ECHO_ON:
        reply[replies].resp_retcode = PAM_SUCCESS;
        reply[replies].resp = COPY_STRING(PAM_username);
          /* PAM frees resp */
        break;
      case PAM_PROMPT_ECHO_OFF:
        reply[replies].resp_retcode = PAM_SUCCESS;
        reply[replies].resp = COPY_STRING(PAM_password);
          /* PAM frees resp */
        break;
      case PAM_TEXT_INFO:
	/* fall through */
      case PAM_ERROR_MSG:
        /* ignore it... */
        reply[replies].resp_retcode = PAM_SUCCESS;
        reply[replies].resp = NULL;
        break;
      default:
        /* Must be an error of some sort... */
        free (reply);
        return PAM_CONV_ERR;
    }
  }
  if (reply) *resp = reply;
  return PAM_SUCCESS;
}
static struct pam_conv PAM_conversation = {
    &PAM_conv,
    NULL
};


static BOOL pam_auth(char *user,char *password)
{
  pam_handle_t *pamh;
  int pam_error;

  /* Now use PAM to do authentication.  For now, we won't worry about
   * session logging, only authentication.  Bail out if there are any
   * errors.  Since this is a limited protocol, and an even more limited
   * function within a server speaking this protocol, we can't be as
   * verbose as would otherwise make sense.
   * Query: should we be using PAM_SILENT to shut PAM up?
   */
  #define PAM_BAIL if (pam_error != PAM_SUCCESS) { \
     pam_end(pamh, 0); return False; \
   }
  PAM_password = password;
  PAM_username = user;
  pam_error = pam_start("samba", user, &PAM_conversation, &pamh);
  PAM_BAIL;
/* Setting PAM_SILENT stops generation of error messages to syslog
 * to enable debugging on Red Hat Linux set:
 * /etc/pam.d/samba:
 *	auth required /lib/security/pam_pwdb.so nullok shadow audit
 * _OR_ change PAM_SILENT to 0 to force detailed reporting (logging)
 */
  pam_error = pam_authenticate(pamh, PAM_SILENT);
  PAM_BAIL;
  /* It is not clear to me that account management is the right thing
   * to do, but it is not clear that it isn't, either.  This can be
   * removed if no account management should be done.  Alternately,
   * put a pam_allow.so entry in /etc/pam.conf for account handling. */
  pam_error = pam_acct_mgmt(pamh, PAM_SILENT);
  PAM_BAIL;
  pam_end(pamh, PAM_SUCCESS);
  /* If this point is reached, the user has been authenticated. */
  return(True);
}
#endif


#ifdef WITH_AFS
/*******************************************************************
check on AFS authentication
********************************************************************/
static BOOL afs_auth(char *user,char *password)
{
	long password_expires = 0;
	char *reason;
    
	/* For versions of AFS prior to 3.3, this routine has few arguments, */
	/* but since I can't find the old documentation... :-)               */
	setpag();
	if (ka_UserAuthenticateGeneral(KA_USERAUTH_VERSION+KA_USERAUTH_DOSETPAG,
				       user,
				       (char *) 0, /* instance */
				       (char *) 0, /* cell */
				       password,
				       0,          /* lifetime, default */
				       &password_expires, /*days 'til it expires */
				       0,          /* spare 2 */
				       &reason) == 0) {
		return(True);
	}
	return(False);
}
#endif


#ifdef WITH_DFS

/*****************************************************************
 This new version of the DFS_AUTH code was donated by Karsten Muuss
 <muuss@or.uni-bonn.de>. It fixes the following problems with the
 old code :

  - Server credentials may expire
  - Client credential cache files have wrong owner
  - purge_context() function is called with invalid argument

 This new code was modified to ensure that on exit the uid/gid is
 still root, and the original directory is restored. JRA.
******************************************************************/

sec_login_handle_t my_dce_sec_context;
int dcelogin_atmost_once = 0;

/*******************************************************************
check on a DCE/DFS authentication
********************************************************************/
static BOOL dfs_auth(char *user,char *password)
{
	error_status_t err;
	int err2;
	int prterr;
	signed32 expire_time, current_time;
	boolean32 password_reset;
	struct passwd *pw;
	sec_passwd_rec_t passwd_rec;
	sec_login_auth_src_t auth_src = sec_login_auth_src_network;
	unsigned char dce_errstr[dce_c_error_string_len];

	if (dcelogin_atmost_once) return(False);

#ifdef HAVE_CRYPT
	/*
	 * We only go for a DCE login context if the given password
	 * matches that stored in the local password file.. 
	 * Assumes local passwd file is kept in sync w/ DCE RGY!
	 */

	if (strcmp((char *)crypt(password,this_salt),this_crypted)) {
		return(False);
	}
#endif

	sec_login_get_current_context(&my_dce_sec_context, &err);
	if (err != error_status_ok ) {  
		dce_error_inq_text(err, dce_errstr, &err2);
		DEBUG(0,("DCE can't get current context. %s\n", dce_errstr));

		return(False);
	}

	sec_login_certify_identity(my_dce_sec_context, &err);
	if (err != error_status_ok) {  
		dce_error_inq_text(err, dce_errstr, &err2);
		DEBUG(0,("DCE can't get current context. %s\n", dce_errstr));
		
		return(False);
	}

	sec_login_get_expiration(my_dce_sec_context, &expire_time, &err);
	if (err != error_status_ok) {
		dce_error_inq_text(err, dce_errstr, &err2);
		DEBUG(0,("DCE can't get expiration. %s\n", dce_errstr));
		
		return(False);
	}
  
	time(&current_time);

	if (expire_time < (current_time + 60)) {
		struct passwd    *pw;
		sec_passwd_rec_t *key;
  
		sec_login_get_pwent(my_dce_sec_context, 
				    (sec_login_passwd_t*)&pw, &err);
		if (err != error_status_ok ) {
			dce_error_inq_text(err, dce_errstr, &err2);
			DEBUG(0,("DCE can't get pwent. %s\n", dce_errstr));
			
			return(False);
		}
		
		sec_login_refresh_identity(my_dce_sec_context, &err);
		if (err != error_status_ok) { 
			dce_error_inq_text(err, dce_errstr, &err2);
			DEBUG(0,("DCE can't refresh identity. %s\n", 
				 dce_errstr));
			
			return(False);
		}
  
		sec_key_mgmt_get_key(rpc_c_authn_dce_secret, NULL,
				     (unsigned char *)pw->pw_name,
				     sec_c_key_version_none,
				     (void**)&key, &err);
		if (err != error_status_ok) {
			dce_error_inq_text(err, dce_errstr, &err2);
			DEBUG(0,("DCE can't get key for %s. %s\n", 
				 pw->pw_name, dce_errstr));

			return(False);
		}
  
		sec_login_valid_and_cert_ident(my_dce_sec_context, key,
					       &password_reset, &auth_src, 
					       &err);
		if (err != error_status_ok ) {
			dce_error_inq_text(err, dce_errstr, &err2);
			DEBUG(0,("DCE can't validate and certify identity for %s. %s\n", 
				 pw->pw_name, dce_errstr));
		}
  
		sec_key_mgmt_free_key(key, &err);
		if (err != error_status_ok ) {
			dce_error_inq_text(err, dce_errstr, &err2);
			DEBUG(0,("DCE can't free key.\n", dce_errstr));
		}
	}

	if (sec_login_setup_identity((unsigned char *)user,
				     sec_login_no_flags,
				     &my_dce_sec_context,
				     &err) == 0) {
		dce_error_inq_text(err, dce_errstr, &err2);
		DEBUG(0,("DCE Setup Identity for %s failed: %s\n",
			 user,dce_errstr));
		return(False);
	}

	sec_login_get_pwent(my_dce_sec_context, 
			    (sec_login_passwd_t*)&pw, &err);
	if (err != error_status_ok) {
		dce_error_inq_text(err, dce_errstr, &err2);
		DEBUG(0,("DCE can't get pwent. %s\n", dce_errstr));
		
		return(False);
	}

	sec_login_purge_context(&my_dce_sec_context, &err);
	if (err != error_status_ok) {
		dce_error_inq_text(err, dce_errstr, &err2);
		DEBUG(0,("DCE can't purge context. %s\n", dce_errstr));

		return(False);
	}

	/*
	 * NB. I'd like to change these to call something like become_user()
	 * instead but currently we don't have a connection
	 * context to become the correct user. This is already
	 * fairly platform specific code however, so I think
	 * this should be ok. I have added code to go
	 * back to being root on error though. JRA.
	 */
	
	if (setregid(-1, pw->pw_gid) != 0) {
		DEBUG(0,("Can't set egid to %d (%s)\n", 
			 pw->pw_gid, strerror(errno)));
		return False;
	}

	if (setreuid(-1, pw->pw_uid) != 0) {
		setgid(0);
		DEBUG(0,("Can't set euid to %d (%s)\n", 
			 pw->pw_uid, strerror(errno)));
		return False;
	}
 
	if (sec_login_setup_identity((unsigned char *)user,
				     sec_login_no_flags,
				     &my_dce_sec_context,
				     &err) == 0) {
		dce_error_inq_text(err, dce_errstr, &err2);
		/* Go back to root, JRA. */
		setuid(0);
		setgid(0);
		DEBUG(0,("DCE Setup Identity for %s failed: %s\n",
			 user,dce_errstr));
		return(False);
	}

	sec_login_get_pwent(my_dce_sec_context, 
			    (sec_login_passwd_t*)&pw, &err);
	if (err != error_status_ok ) {
		dce_error_inq_text(err, dce_errstr, &err2);
		/* Go back to root, JRA. */
		setuid(0);
		setgid(0);
		DEBUG(0,("DCE can't get pwent. %s\n", dce_errstr));
		
		return(False);
	}

	passwd_rec.version_number = sec_passwd_c_version_none;
	passwd_rec.pepper = NULL;
	passwd_rec.key.key_type = sec_passwd_plain;
	passwd_rec.key.tagged_union.plain  = (idl_char *)password;
	
	sec_login_validate_identity(my_dce_sec_context,
				    &passwd_rec, &password_reset,
				    &auth_src, &err);
	if (err != error_status_ok ) { 
		dce_error_inq_text(err, dce_errstr, &err2);
		/* Go back to root, JRA. */
		setuid(0);
		setgid(0);
		DEBUG(0,("DCE Identity Validation failed for principal %s: %s\n",
			 user,dce_errstr));
		
		return(False);
	}

	sec_login_certify_identity(my_dce_sec_context, &err);
	if (err != error_status_ok) { 
		dce_error_inq_text(err, dce_errstr, &err2);
		/* Go back to root, JRA. */
		setuid(0);
		setgid(0);
		DEBUG(0,("DCE certify identity failed: %s\n", dce_errstr));
		
		return(False);
	}

	if (auth_src != sec_login_auth_src_network) { 
		DEBUG(0,("DCE context has no network credentials.\n"));
	}

	sec_login_set_context(my_dce_sec_context, &err);
	if (err != error_status_ok) {  
		dce_error_inq_text(err, dce_errstr, &err2);
		DEBUG(0,("DCE login failed for principal %s, cant set context: %s\n",
			 user,dce_errstr));
		
		sec_login_purge_context(&my_dce_sec_context, &err);
		/* Go back to root, JRA. */
		setuid(0);
		setgid(0);
		return(False);
	}
	
	sec_login_get_pwent(my_dce_sec_context, 
			    (sec_login_passwd_t*)&pw, &err);
	if (err != error_status_ok) {
		dce_error_inq_text(err, dce_errstr, &err2);
		DEBUG(0,("DCE can't get pwent. %s\n", dce_errstr));

		/* Go back to root, JRA. */
		setuid(0);
		setgid(0);
		return(False);
	}
	
	DEBUG(0,("DCE login succeeded for principal %s on pid %d\n",
		 user, getpid()));
	
	DEBUG(3,("DCE principal: %s\n"
		 "          uid: %d\n"
		 "          gid: %d\n",
		 pw->pw_name, pw->pw_uid, pw->pw_gid));
	DEBUG(3,("         info: %s\n"
		 "          dir: %s\n"
		 "        shell: %s\n",
		 pw->pw_gecos, pw->pw_dir, pw->pw_shell));
	
	sec_login_get_expiration(my_dce_sec_context, &expire_time, &err);
	if (err != error_status_ok) {
		dce_error_inq_text(err, dce_errstr, &err2);
		/* Go back to root, JRA. */
		setuid(0);
		setgid(0);
		DEBUG(0,("DCE can't get expiration. %s\n", dce_errstr));
		
		return(False);
	}
	
	setuid(0);
	setgid(0);
	
	DEBUG(0,("DCE context expires: %s",asctime(localtime(&expire_time))));
	
	dcelogin_atmost_once = 1;
	return (True);
}

void dfs_unlogin(void)
{
	error_status_t err;
	int err2;
	unsigned char dce_errstr[dce_c_error_string_len];
	
	sec_login_purge_context(&my_dce_sec_context, &err);
	if (err != error_status_ok) {  
		dce_error_inq_text(err, dce_errstr, &err2);
		DEBUG(0,("DCE purge login context failed for server instance %d: %s\n",
			 getpid(), dce_errstr));
	}
}
#endif

#ifdef KRB5_AUTH
/*******************************************************************
check on Kerberos authentication
********************************************************************/
static BOOL krb5_auth(char *user,char *password)
{
	krb5_data tgtname = {
		0,
		KRB5_TGS_NAME_SIZE,
	 	KRB5_TGS_NAME
 	};
	krb5_context kcontext;
	krb5_principal kprinc;
	krb5_principal server;
	krb5_creds kcreds;
	int options = 0;
	krb5_address **addrs = (krb5_address **)0;
	krb5_preauthtype *preauth = NULL;
	krb5_keytab keytab = NULL;
	krb5_timestamp now;
	krb5_ccache ccache = NULL;
	int retval;
	char *name;

	if (retval=krb5_init_context(&kcontext)) {
		return(False);
	}

	if (retval = krb5_timeofday(kcontext, &now)) {
		return(False);
	}

	if (retval = krb5_cc_default(kcontext, &ccache)) {
		return(False);
	}
	
	if (retval = krb5_parse_name(kcontext, user, &kprinc)) {
		return(False);
	}

	memset((char *)&kcreds, 0, sizeof(kcreds));

	kcreds.client = kprinc;
	
	if ((retval = krb5_build_principal_ext(kcontext, &server,
		krb5_princ_realm(kcontext, kprinc)->length,
		krb5_princ_realm(kcontext, kprinc)->data,
		tgtname.length,
		tgtname.data,
		krb5_princ_realm(kcontext, kprinc)->length,
		krb5_princ_realm(kcontext, kprinc)->data,
		0))) {
 		return(False);
	}

	kcreds.server = server;

	retval = krb5_get_in_tkt_with_password(kcontext,
					       options,
					       addrs,
					       NULL,
					       preauth,
					       password,
					       0,
					       &kcreds,
					       0);

	if (retval) {
		return(False);
	}

	return(True);
}
#endif /* KRB5_AUTH */

#ifdef KRB4_AUTH
/*******************************************************************
check on Kerberos authentication
********************************************************************/
static BOOL krb4_auth(char *user,char *password)
{
	char realm[REALM_SZ];
	char tkfile[MAXPATHLEN];
  
	if (krb_get_lrealm(realm, 1) != KSUCCESS) {
		(void) safe_strcpy(realm, KRB_REALM, sizeof (realm) - 1);
	}

	(void) slprintf(tkfile, sizeof(tkfile) - 1, "/tmp/samba_tkt_%d", 
			getpid());
  
	krb_set_tkt_string(tkfile);
	if (krb_verify_user(user, "", realm,
			    password, 0,
			    "rmcd") == KSUCCESS) {
		unlink(tkfile);
		return 1;
	}
	unlink(tkfile);
	return 0;
}
#endif /* KRB4_AUTH */

#ifdef LINUX_BIGCRYPT
/****************************************************************************
an enhanced crypt for Linux to handle password longer than 8 characters
****************************************************************************/
static int linux_bigcrypt(char *password,char *salt1, char *crypted)
{
#define LINUX_PASSWORD_SEG_CHARS 8
	char salt[3];
	int i;
  
	StrnCpy(salt,salt1,2);
	crypted +=2;
  
	for ( i=strlen(password); i > 0; i -= LINUX_PASSWORD_SEG_CHARS) {
		char * p = crypt(password,salt) + 2;
		if (strncmp(p, crypted, LINUX_PASSWORD_SEG_CHARS) != 0)
			return(0);
		password += LINUX_PASSWORD_SEG_CHARS;
		crypted  += strlen(p);
	}
  
	return(1);
}
#endif

#ifdef OSF1_ENH_SEC
/****************************************************************************
an enhanced crypt for OSF1
****************************************************************************/
static char *osf1_bigcrypt(char *password,char *salt1)
{
	static char result[AUTH_MAX_PASSWD_LENGTH] = "";
	char *p1;
	char *p2=password;
	char salt[3];
	int i;
	int parts = strlen(password) / AUTH_CLEARTEXT_SEG_CHARS;
	if (strlen(password)%AUTH_CLEARTEXT_SEG_CHARS) {
		parts++;
	}
	
	StrnCpy(salt,salt1,2);
	StrnCpy(result,salt1,2);

	for (i=0; i<parts;i++) {
		p1 = crypt(p2,salt);
		strncat(result,p1+2,AUTH_MAX_PASSWD_LENGTH-strlen(p1+2)-1);
		StrnCpy(salt,&result[2+i*AUTH_CIPHERTEXT_SEG_CHARS],2);
		p2 += AUTH_CLEARTEXT_SEG_CHARS;
	}

	return(result);
}
#endif


/****************************************************************************
apply a function to upper/lower case combinations
of a string and return true if one of them returns true.
try all combinations with N uppercase letters.
offset is the first char to try and change (start with 0)
it assumes the string starts lowercased
****************************************************************************/
static BOOL string_combinations2(char *s,int offset,BOOL (*fn)(char *),int N)
{
	int len = strlen(s);
	int i;

#ifdef PASSWORD_LENGTH
	len = MIN(len,PASSWORD_LENGTH);
#endif

	if (N <= 0 || offset >= len) {
		return(fn(s));
	}

	for (i=offset;i<(len-(N-1));i++) {      
		char c = s[i];
		if (!islower(c)) continue;
		s[i] = toupper(c);
		if (string_combinations2(s,i+1,fn,N-1))
			return(True);
		s[i] = c;
	}
	return(False);
}

/****************************************************************************
apply a function to upper/lower case combinations
of a string and return true if one of them returns true.
try all combinations with up to N uppercase letters.
offset is the first char to try and change (start with 0)
it assumes the string starts lowercased
****************************************************************************/
static BOOL string_combinations(char *s,BOOL (*fn)(char *),int N)
{
	int n;
	for (n=1;n<=N;n++)
		if (string_combinations2(s,0,fn,n)) return(True);
	return(False);
}


/****************************************************************************
core of password checking routine
****************************************************************************/
static BOOL password_check(char *password)
{

#ifdef HAVE_PAM
	/* This falls through if the password check fails
	   - if HAVE_CRYPT is not defined this causes an error msg
	   saying Warning - no crypt available
	   - if HAVE_CRYPT is defined this is a potential security hole
	   as it may authenticate via the crypt call when PAM
	   settings say it should fail.
	   if (pam_auth(user,password)) return(True);
	   Hence we make a direct return to avoid a second chance!!!
	*/
	return (pam_auth(this_user,password));
#endif
	
#ifdef WITH_AFS
	if (afs_auth(this_user,password)) return(True);
#endif
	
#ifdef WITH_DFS
	if (dfs_auth(this_user,password)) return(True);
#endif 

#ifdef KRB5_AUTH
	if (krb5_auth(this_user,password)) return(True);
#endif

#ifdef KRB4_AUTH
	if (krb4_auth(this_user,password)) return(True);
#endif

#ifdef OSF1_ENH_SEC
	{
	  BOOL ret = (strcmp(osf1_bigcrypt(password,this_salt),this_crypted) == 0);
	  if(!ret) {
		  DEBUG(2,("OSF1_ENH_SEC failed. Trying normal crypt.\n"));
		  ret = (strcmp((char *)crypt(password,this_salt),this_crypted) == 0);
	  }
	  return ret;
	}
#endif

#ifdef ULTRIX_AUTH
	return (strcmp((char *)crypt16(password, this_salt ),this_crypted) == 0);
#endif

#ifdef LINUX_BIGCRYPT
	return(linux_bigcrypt(password,this_salt,this_crypted));
#endif

#ifdef HAVE_BIGCRYPT
	return(strcmp(bigcrypt(password,this_salt),this_crypted) == 0);
#endif

#ifndef HAVE_CRYPT
	DEBUG(1,("Warning - no crypt available\n"));
	return(False);
#else
	return(strcmp((char *)crypt(password,this_salt),this_crypted) == 0);
#endif
}



/****************************************************************************
check if a username/password is OK
the function pointer fn() points to a function to call when a successful
match is found and is used to update the encrypted password file 
return True on correct match, False otherwise
****************************************************************************/
BOOL pass_check(char *user,char *password, int pwlen, struct passwd *pwd,
		BOOL (*fn)(char *, char *))
{
	pstring pass2;
	int level = lp_passwordlevel();
	struct passwd *pass;

	if (password) password[pwlen] = 0;

#if DEBUG_PASSWORD
	DEBUG(100,("checking user=[%s] pass=[%s]\n",user,password));
#endif

	if (!password) {
		return(False);
	}

	if (((!*password) || (!pwlen)) && !lp_null_passwords()) {
		return(False);
	}

	if (pwd && !user) {
		pass = (struct passwd *) pwd;
		user = pass->pw_name;
	} else {
		pass = Get_Pwnam(user,True);
	}


	DEBUG(4,("Checking password for user %s (l=%d)\n",user,pwlen));

	if (!pass) {
		DEBUG(3,("Couldn't find user %s\n",user));
		return(False);
	}

#ifdef HAVE_GETSPNAM
	{
		struct spwd *spass;

		/* many shadow systems require you to be root to get
		   the password, in most cases this should already be
		   the case when this function is called, except
		   perhaps for IPC password changing requests */

		spass = getspnam(pass->pw_name);
		if (spass && spass->sp_pwdp) {
			pass->pw_passwd = spass->sp_pwdp;
		}
	}
#elif defined(IA_UINFO)
	{
		/* Need to get password with SVR4.2's ia_ functions
		   instead of get{sp,pw}ent functions. Required by
		   UnixWare 2.x, tested on version
		   2.1. (tangent@cyberport.com) */
		uinfo_t uinfo;
		if (ia_openinfo(pass->pw_name, &uinfo) != -1) {
			ia_get_logpwd(uinfo, &(pass->pw_passwd));
		}
	}
#endif

#ifdef HAVE_GETPRPWNAM
	{
		struct pr_passwd *pr_pw = getprpwnam(pass->pw_name);
		if (pr_pw && pr_pw->ufld.fd_encrypt)
			pass->pw_passwd = pr_pw->ufld.fd_encrypt;
	}
#endif

#ifdef OSF1_ENH_SEC
	{
		struct pr_passwd *mypasswd;
		DEBUG(5,("Checking password for user %s in OSF1_ENH_SEC\n",
			 user));
		mypasswd = getprpwnam (user);
		if (mypasswd) { 
			fstrcpy(pass->pw_name,mypasswd->ufld.fd_name);
			fstrcpy(pass->pw_passwd,mypasswd->ufld.fd_encrypt);
		} else {
			DEBUG(5,("No entry for user %s in protected database !\n",
				 user));
			return(False);
		}
	}
#endif

#ifdef ULTRIX_AUTH
	{
		AUTHORIZATION *ap = getauthuid(pass->pw_uid);
		if (ap) {
			fstrcpy(pass->pw_passwd, ap->a_password);
			endauthent();
		}
	}
#endif

	/* extract relevant info */
	fstrcpy(this_user,pass->pw_name);  
	fstrcpy(this_salt,pass->pw_passwd);
	/* crypt on some platforms (HPUX in particular)
	   won't work with more than 2 salt characters. */
	this_salt[2] = 0;
	
	fstrcpy(this_crypted,pass->pw_passwd);
	
	if (!*this_crypted) {
		if (!lp_null_passwords()) {
			DEBUG(2,("Disallowing %s with null password\n",
				 this_user));
			return(False);
		}
		if (!*password) {
			DEBUG(3,("Allowing access to %s with null password\n",
				 this_user));
			return(True);
		}
	}

	/* try it as it came to us */
	if (password_check(password)) {
		update_protected_database(user,True);
		if (fn) fn(user,password);
		return(True);
	}

	/* if the password was given to us with mixed case then we don't
	   need to proceed as we know it hasn't been case modified by the
	   client */
	if (strhasupper(password) && strhaslower(password)) {
		return(False);
	}

	/* make a copy of it */
	StrnCpy(pass2,password,sizeof(pstring)-1);
  
	/* try all lowercase */
	strlower(password);
	if (password_check(password)) {
		update_protected_database(user,True);
		if (fn) fn(user,password);
		return(True);
	}

	/* give up? */
	if (level < 1) {
		update_protected_database(user,False);

		/* restore it */
		fstrcpy(password,pass2);
		
		return(False);
	}

	/* last chance - all combinations of up to level chars upper! */
	strlower(password);

	if (string_combinations(password,password_check,level)) {
		update_protected_database(user,True);
		if (fn) fn(user,password);
		return(True);
	}

	update_protected_database(user,False);
  
	/* restore it */
	fstrcpy(password,pass2);
  
	return(False);
}