summaryrefslogtreecommitdiffstats
path: root/servers/slapd/overlays/otp.c
blob: b39c18647c4960b41646f707722b2f4a28382a1e (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
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
/* otp.c - OATH 2-factor authentication module */
/* $OpenLDAP$ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
 *
 * Copyright 2015-2024 The OpenLDAP Foundation.
 * Portions Copyright 2015 by Howard Chu, Symas Corp.
 * Portions Copyright 2016-2017 by Michael Ströder <michael@stroeder.com>
 * Portions Copyright 2018 by Ondřej Kuzník, Symas Corp.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted only as authorized by the OpenLDAP
 * Public License.
 *
 * A copy of this license is available in the file LICENSE in the
 * top-level directory of the distribution or, alternatively, at
 * <http://www.OpenLDAP.org/license.html>.
 */
/* ACKNOWLEDGEMENTS:
 * This work includes code from the lastbind overlay.
 */

#include <portable.h>

#ifdef SLAPD_OVER_OTP

#if HAVE_STDINT_H
#include <stdint.h>
#endif

#include <lber.h>
#include <lber_pvt.h>
#include "lutil.h"
#include <ac/stdlib.h>
#include <ac/ctype.h>
#include <ac/string.h>
/* include socket.h to get sys/types.h and/or winsock2.h */
#include <ac/socket.h>

#if HAVE_OPENSSL
#include <openssl/sha.h>
#include <openssl/hmac.h>

#define TOTP_SHA512_DIGEST_LENGTH SHA512_DIGEST_LENGTH

#if OPENSSL_VERSION_MAJOR >= 3
#define TOTP_SHA1 SN_sha1
#define TOTP_SHA224 SN_sha224
#define TOTP_SHA256 SN_sha256
#define TOTP_SHA384 SN_sha384
#define TOTP_SHA512 SN_sha512
#define TOTP_HMAC_CTX	EVP_MAC_CTX *
#else
#define TOTP_SHA1 EVP_sha1()
#define TOTP_SHA224 EVP_sha224()
#define TOTP_SHA256 EVP_sha256()
#define TOTP_SHA384 EVP_sha384()
#define TOTP_SHA512 EVP_sha512()
#define TOTP_HMAC_CTX HMAC_CTX *
#endif

#if OPENSSL_VERSION_NUMBER < 0x10100000L
static HMAC_CTX *
HMAC_CTX_new( void )
{
	HMAC_CTX *ctx = OPENSSL_malloc( sizeof(*ctx) );
	if ( ctx != NULL ) {
		HMAC_CTX_init( ctx );
	}
	return ctx;
}

static void
HMAC_CTX_free( HMAC_CTX *ctx )
{
	if ( ctx != NULL ) {
		HMAC_CTX_cleanup( ctx );
		OPENSSL_free( ctx );
	}
}
#endif /* OPENSSL_VERSION_NUMBER < 0x10100000L */

#if OPENSSL_VERSION_MAJOR >= 3
static EVP_MAC *evp_mac;
#define HMAC_setup( ctx, key, len, hash ) \
	{ OSSL_PARAM params[2]; \
	ctx = EVP_MAC_CTX_new( evp_mac ); \
	params[0] = OSSL_PARAM_construct_utf8_string( "digest", (char *)hash, 0 ); \
	params[1] = OSSL_PARAM_construct_end(); \
	EVP_MAC_init( ctx, key, len, params ); }
#define HMAC_crunch( ctx, buf, len ) EVP_MAC_update( ctx, buf, len )
#define HMAC_finish( ctx, dig, dlen ) \
	{ size_t outlen; \
	EVP_MAC_final( ctx, dig, &outlen, TOTP_SHA512_DIGEST_LENGTH ); \
	dlen = outlen; } \
	EVP_MAC_CTX_free( ctx )

#else
#define HMAC_setup( ctx, key, len, hash ) \
	ctx = HMAC_CTX_new(); \
	HMAC_Init_ex( ctx, key, len, hash, 0 )
#define HMAC_crunch( ctx, buf, len ) HMAC_Update( ctx, buf, len )
#define HMAC_finish( ctx, dig, dlen ) \
	HMAC_Final( ctx, dig, &dlen ); \
	HMAC_CTX_free( ctx )
#endif

#elif HAVE_GNUTLS
#include <nettle/hmac.h>

#define TOTP_SHA512_DIGEST_LENGTH SHA512_DIGEST_SIZE
#define TOTP_SHA1 &nettle_sha1
#define TOTP_SHA224 &nettle_sha224
#define TOTP_SHA256 &nettle_sha256
#define TOTP_SHA384 &nettle_sha384
#define TOTP_SHA512 &nettle_sha512
#define TOTP_HMAC_CTX struct hmac_sha512_ctx

#define HMAC_setup( ctx, key, len, hash ) \
	const struct nettle_hash *h = hash; \
	hmac_set_key( &ctx.outer, &ctx.inner, &ctx.state, h, len, key )
#define HMAC_crunch( ctx, buf, len ) hmac_update( &ctx.state, h, len, buf )
#define HMAC_finish( ctx, dig, dlen ) \
	hmac_digest( &ctx.outer, &ctx.inner, &ctx.state, h, h->digest_size, dig ); \
	dlen = h->digest_size

#else
#error Unsupported crypto backend.
#endif

#include "slap.h"
#include "slap-config.h"

/* Schema from OATH-LDAP project by Michael Ströder */

static struct {
	char *name, *oid;
} otp_oid[] = {
	{ "oath-ldap", "1.3.6.1.4.1.5427.1.389.4226" },
	{ "oath-ldap-at", "oath-ldap:4" },
	{ "oath-ldap-oc", "oath-ldap:6" },
	{ NULL }
};

AttributeDescription *ad_oathOTPToken;
AttributeDescription *ad_oathSecret;
AttributeDescription *ad_oathOTPLength;
AttributeDescription *ad_oathHMACAlgorithm;

AttributeDescription *ad_oathHOTPParams;
AttributeDescription *ad_oathHOTPToken;
AttributeDescription *ad_oathHOTPCounter;
AttributeDescription *ad_oathHOTPLookahead;

AttributeDescription *ad_oathTOTPTimeStepPeriod;
AttributeDescription *ad_oathTOTPParams;
AttributeDescription *ad_oathTOTPToken;
AttributeDescription *ad_oathTOTPLastTimeStep;
AttributeDescription *ad_oathTOTPTimeStepWindow;
AttributeDescription *ad_oathTOTPTimeStepDrift;

static struct otp_at {
	char					*schema;
	AttributeDescription	**adp;
} otp_at[] = {
	{ "( oath-ldap-at:1 "
		"NAME 'oathSecret' "
		"DESC 'OATH-LDAP: Shared Secret (possibly encrypted with public key in oathEncKey)' "
		"X-ORIGIN 'OATH-LDAP' "
		"SINGLE-VALUE "
		"EQUALITY octetStringMatch "
		"SUBSTR octetStringSubstringsMatch "
		"SYNTAX 1.3.6.1.4.1.1466.115.121.1.40 )",
		&ad_oathSecret },

	{ "( oath-ldap-at:2 "
		"NAME 'oathTokenSerialNumber' "
		"DESC 'OATH-LDAP: Proprietary hardware token serial number assigned by vendor' "
		"X-ORIGIN 'OATH-LDAP' "
		"SINGLE-VALUE "
		"EQUALITY caseIgnoreMatch "
		"SUBSTR caseIgnoreSubstringsMatch "
		"SYNTAX 1.3.6.1.4.1.1466.115.121.1.44{64})" },

	{ "( oath-ldap-at:3 "
		"NAME 'oathTokenIdentifier' "
		"DESC 'OATH-LDAP: Globally unique OATH token identifier' "
		"X-ORIGIN 'OATH-LDAP' "
		"SINGLE-VALUE "
		"EQUALITY caseIgnoreMatch "
		"SYNTAX 1.3.6.1.4.1.1466.115.121.1.15{256} )" },

	{ "( oath-ldap-at:4 "
		"NAME 'oathParamsEntry' "
		"DESC 'OATH-LDAP: DN pointing to OATH parameter/policy object' "
		"X-ORIGIN 'OATH-LDAP' "
		"SINGLE-VALUE "
		"SUP distinguishedName )" },
	{ "( oath-ldap-at:4.1 "
		"NAME 'oathTOTPTimeStepPeriod' "
		"DESC 'OATH-LDAP: Time window for TOTP (seconds)' "
		"X-ORIGIN 'OATH-LDAP' "
		"SINGLE-VALUE "
		"EQUALITY integerMatch "
		"ORDERING integerOrderingMatch "
		"SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 )",
		&ad_oathTOTPTimeStepPeriod },

	{ "( oath-ldap-at:5 "
		"NAME 'oathOTPLength' "
		"DESC 'OATH-LDAP: Length of OTP (number of digits)' "
		"X-ORIGIN 'OATH-LDAP' "
		"SINGLE-VALUE "
		"EQUALITY integerMatch "
		"ORDERING integerOrderingMatch "
		"SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 )",
		&ad_oathOTPLength },
	{ "( oath-ldap-at:5.1 "
		"NAME 'oathHOTPParams' "
		"DESC 'OATH-LDAP: DN pointing to HOTP parameter object' "
		"X-ORIGIN 'OATH-LDAP' "
		"SINGLE-VALUE "
        "SUP oathParamsEntry )",
		&ad_oathHOTPParams },
	{ "( oath-ldap-at:5.2 "
		"NAME 'oathTOTPParams' "
		"DESC 'OATH-LDAP: DN pointing to TOTP parameter object' "
		"X-ORIGIN 'OATH-LDAP' "
		"SINGLE-VALUE "
		"SUP oathParamsEntry )",
		&ad_oathTOTPParams },

	{ "( oath-ldap-at:6 "
		"NAME 'oathHMACAlgorithm' "
		"DESC 'OATH-LDAP: HMAC algorithm used for generating OTP values' "
		"X-ORIGIN 'OATH-LDAP' "
		"SINGLE-VALUE "
		"EQUALITY objectIdentifierMatch "
		"SYNTAX 1.3.6.1.4.1.1466.115.121.1.38 )",
		&ad_oathHMACAlgorithm },

	{ "( oath-ldap-at:7 "
		"NAME 'oathTimestamp' "
		"DESC 'OATH-LDAP: Timestamp (not directly used).' "
		"X-ORIGIN 'OATH-LDAP' "
		"SINGLE-VALUE "
		"EQUALITY generalizedTimeMatch "
		"ORDERING generalizedTimeOrderingMatch "
		"SYNTAX 1.3.6.1.4.1.1466.115.121.1.24 )" },
	{ "( oath-ldap-at:7.1 "
        "NAME 'oathLastFailure' "
        "DESC 'OATH-LDAP: Timestamp of last failed OATH validation' "
        "X-ORIGIN 'OATH-LDAP' "
        "SINGLE-VALUE "
        "SUP oathTimestamp )" },
	{ "( oath-ldap-at:7.2 "
        "NAME 'oathLastLogin' "
        "DESC 'OATH-LDAP: Timestamp of last successful OATH validation' "
        "X-ORIGIN 'OATH-LDAP' "
        "SINGLE-VALUE "
        "SUP oathTimestamp )" },
	{ "( oath-ldap-at:7.3 "
        "NAME 'oathSecretTime' "
        "DESC 'OATH-LDAP: Timestamp of generation of oathSecret attribute.' "
        "X-ORIGIN 'OATH-LDAP' "
        "SINGLE-VALUE "
        "SUP oathTimestamp )" },

	{ "( oath-ldap-at:8 "
		"NAME 'oathSecretMaxAge' "
		"DESC 'OATH-LDAP: Time in seconds for which the shared secret (oathSecret) will be valid from oathSecretTime value.' "
		"X-ORIGIN 'OATH-LDAP' "
		"SINGLE-VALUE "
		"EQUALITY integerMatch "
		"ORDERING integerOrderingMatch "
		"SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 )" },

	{ "( oath-ldap-at:9 "
		"NAME 'oathToken' "
		"DESC 'OATH-LDAP: DN pointing to OATH token object' "
		"X-ORIGIN 'OATH-LDAP' "
		"SINGLE-VALUE "
		"SUP distinguishedName )" },
	{ "( oath-ldap-at:9.1 "
        "NAME 'oathHOTPToken' "
        "DESC 'OATH-LDAP: DN pointing to OATH/HOTP token object' "
        "X-ORIGIN 'OATH-LDAP' "
        "SINGLE-VALUE "
        "SUP oathToken )",
		&ad_oathHOTPToken },
	{ "( oath-ldap-at:9.2 "
		"NAME 'oathTOTPToken' "
		"DESC 'OATH-LDAP: DN pointing to OATH/TOTP token object' "
		"X-ORIGIN 'OATH-LDAP' "
		"SINGLE-VALUE "
		"SUP oathToken )",
		&ad_oathTOTPToken },

	{ "( oath-ldap-at:10 "
		"NAME 'oathCounter' "
		"DESC 'OATH-LDAP: Counter for OATH data (not directly used)' "
		"X-ORIGIN 'OATH-LDAP' "
		"SINGLE-VALUE "
		"EQUALITY integerMatch "
		"ORDERING integerOrderingMatch "
		"SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 )" },
	{ "( oath-ldap-at:10.1 "
        "NAME 'oathFailureCount' "
        "DESC 'OATH-LDAP: OATH failure counter' "
        "X-ORIGIN 'OATH-LDAP' "
        "SINGLE-VALUE "
        "SUP oathCounter )" },
	{ "( oath-ldap-at:10.2 "
        "NAME 'oathHOTPCounter' "
              "DESC 'OATH-LDAP: Counter for HOTP' "
        "X-ORIGIN 'OATH-LDAP' "
        "SINGLE-VALUE "
        "SUP oathCounter )",
		&ad_oathHOTPCounter },
	{ "( oath-ldap-at:10.3 "
        "NAME 'oathHOTPLookAhead' "
        "DESC 'OATH-LDAP: Look-ahead window for HOTP' "
        "X-ORIGIN 'OATH-LDAP' "
        "SINGLE-VALUE "
        "SUP oathCounter )",
		&ad_oathHOTPLookahead },
	{ "( oath-ldap-at:10.5 "
        "NAME 'oathThrottleLimit' "
        "DESC 'OATH-LDAP: Failure throttle limit' "
        "X-ORIGIN 'OATH-LDAP' "
        "SINGLE-VALUE "
        "SUP oathCounter )" },
	{ "( oath-ldap-at:10.6 "
		"NAME 'oathTOTPLastTimeStep' "
		"DESC 'OATH-LDAP: Last time step seen for TOTP (time/period)' "
		"X-ORIGIN 'OATH-LDAP' "
		"SINGLE-VALUE "
		"SUP oathCounter )",
		&ad_oathTOTPLastTimeStep },
	{ "( oath-ldap-at:10.7 "
        "NAME 'oathMaxUsageCount' "
        "DESC 'OATH-LDAP: Maximum number of times a token can be used' "
        "X-ORIGIN 'OATH-LDAP' "
        "SINGLE-VALUE "
        "SUP oathCounter )" },
	{ "( oath-ldap-at:10.8 "
        "NAME 'oathTOTPTimeStepWindow' "
        "DESC 'OATH-LDAP: Size of time step +/- tolerance window used for TOTP validation' "
        "X-ORIGIN 'OATH-LDAP' "
        "SINGLE-VALUE "
        "SUP oathCounter )",
		&ad_oathTOTPTimeStepWindow },
	{ "( oath-ldap-at:10.9 "
        "NAME 'oathTOTPTimeStepDrift' "
        "DESC 'OATH-LDAP: Last observed time step shift seen for TOTP' "
        "X-ORIGIN 'OATH-LDAP' "
        "SINGLE-VALUE "
        "SUP oathCounter )",
		&ad_oathTOTPTimeStepDrift },

	{ "( oath-ldap-at:11 "
        "NAME 'oathSecretLength' "
        "DESC 'OATH-LDAP: Length of plain-text shared secret (number of bytes)' "
        "X-ORIGIN 'OATH-LDAP' "
        "SINGLE-VALUE "
        "EQUALITY integerMatch "
        "ORDERING integerOrderingMatch "
        "SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 )" },

	{ "( oath-ldap-at:12 "
        "NAME 'oathEncKey' "
        "DESC 'OATH-LDAP: public key to be used for encrypting new shared secrets' "
        "X-ORIGIN 'OATH-LDAP' "
        "SINGLE-VALUE "
        "EQUALITY caseIgnoreMatch "
        "SUBSTR caseIgnoreSubstringsMatch "
        "SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 )" },

	{ "( oath-ldap-at:13 "
        "NAME 'oathResultCode' "
        "DESC 'OATH-LDAP: LDAP resultCode to use in response' "
        "X-ORIGIN 'OATH-LDAP' "
        "SINGLE-VALUE "
        "EQUALITY integerMatch "
        "ORDERING integerOrderingMatch "
        "SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 )" },
	{ "( oath-ldap-at:13.1 "
        "NAME 'oathSuccessResultCode' "
        "DESC 'OATH-LDAP: success resultCode to use in bind/compare response' "
        "X-ORIGIN 'OATH-LDAP' "
        "SUP oathResultCode )" },
	{ "( oath-ldap-at:13.2 "
        "NAME 'oathFailureResultCode' "
        "DESC 'OATH-LDAP: failure resultCode to use in bind/compare response' "
        "X-ORIGIN 'OATH-LDAP' "
        "SUP oathResultCode )" },

	{ "( oath-ldap-at:14 "
        "NAME 'oathTokenPIN' "
        "DESC 'OATH-LDAP: Configuration PIN (possibly encrypted with oathEncKey)' "
        "X-ORIGIN 'OATH-LDAP' "
        "SINGLE-VALUE "
        "EQUALITY caseIgnoreMatch "
        "SUBSTR caseIgnoreSubstringsMatch "
        "SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 )" },

	{ "( oath-ldap-at:15 "
        "NAME 'oathMessage' "
        "DESC 'OATH-LDAP: success diagnosticMessage to use in bind/compare response' "
        "X-ORIGIN 'OATH-LDAP' "
        "SINGLE-VALUE "
        "EQUALITY caseIgnoreMatch "
        "SUBSTR caseIgnoreSubstringsMatch "
        "SYNTAX 1.3.6.1.4.1.1466.115.121.1.15{1024} )" },
	{ "( oath-ldap-at:15.1 "
        "NAME 'oathSuccessMessage' "
        "DESC 'OATH-LDAP: success diagnosticMessage to use in bind/compare response' "
        "X-ORIGIN 'OATH-LDAP' "
        "SUP oathMessage )" },
	{ "( oath-ldap-at:15.2 "
        "NAME 'oathFailureMessage' "
        "DESC 'OATH-LDAP: failure diagnosticMessage to use in bind/compare response' "
        "X-ORIGIN 'OATH-LDAP' "
        "SUP oathMessage )" },

	{ NULL }
};

ObjectClass *oc_oathOTPUser;
ObjectClass *oc_oathHOTPToken;
ObjectClass *oc_oathTOTPToken;
ObjectClass *oc_oathHOTPParams;
ObjectClass *oc_oathTOTPParams;

static struct otp_oc {
	char			*schema;
	ObjectClass		**ocp;
} otp_oc[] = {
	{ "( oath-ldap-oc:1 "
		"NAME 'oathUser' "
		"DESC 'OATH-LDAP: User Object' "
		"X-ORIGIN 'OATH-LDAP' "
		"ABSTRACT )",
		&oc_oathOTPUser },
	{ "( oath-ldap-oc:1.1 "
		"NAME 'oathHOTPUser' "
		"DESC 'OATH-LDAP: HOTP user object' "
		"X-ORIGIN 'OATH-LDAP' "
		"AUXILIARY "
		"SUP oathUser "
		"MAY ( oathHOTPToken ) )" },
	{ "( oath-ldap-oc:1.2 "
		"NAME 'oathTOTPUser' "
		"DESC 'OATH-LDAP: TOTP user object' "
		"X-ORIGIN 'OATH-LDAP' "
		"AUXILIARY "
		"SUP oathUser "
		"MUST ( oathTOTPToken ) )" },
	{ "( oath-ldap-oc:2 "
		"NAME 'oathParams' "
		"DESC 'OATH-LDAP: Parameter object' "
		"X-ORIGIN 'OATH-LDAP' "
		"ABSTRACT "
		"MUST ( oathOTPLength $ oathHMACAlgorithm ) "
		"MAY ( oathSecretMaxAge $ oathSecretLength $ "
			"oathMaxUsageCount $ oathThrottleLimit $ oathEncKey $ "
			"oathSuccessResultCode $ oathSuccessMessage $ "
			"oathFailureResultCode $ oathFailureMessage ) )" },
	{ "( oath-ldap-oc:2.1 "
		"NAME 'oathHOTPParams' "
		"DESC 'OATH-LDAP: HOTP parameter object' "
		"X-ORIGIN 'OATH-LDAP' "
		"AUXILIARY "
		"SUP oathParams "
		"MUST ( oathHOTPLookAhead ) )",
		&oc_oathHOTPParams },
	{ "( oath-ldap-oc:2.2 "
		"NAME 'oathTOTPParams' "
		"DESC 'OATH-LDAP: TOTP parameter object' "
		"X-ORIGIN 'OATH-LDAP' "
		"AUXILIARY "
		"SUP oathParams "
		"MUST ( oathTOTPTimeStepPeriod ) "
		"MAY ( oathTOTPTimeStepWindow ) )",
		&oc_oathTOTPParams },
	{ "( oath-ldap-oc:3 "
		"NAME 'oathToken' "
		"DESC 'OATH-LDAP: User Object' "
		"X-ORIGIN 'OATH-LDAP' "
		"ABSTRACT "
		"MAY ( oathSecret $ oathSecretTime $ "
			"oathLastLogin $ oathFailureCount $ oathLastFailure $ "
			"oathTokenSerialNumber $ oathTokenIdentifier $ oathTokenPIN ) )" },
	{ "( oath-ldap-oc:3.1 "
		"NAME 'oathHOTPToken' "
		"DESC 'OATH-LDAP: HOTP token object' "
		"X-ORIGIN 'OATH-LDAP' "
		"AUXILIARY "
		"SUP oathToken "
		"MAY ( oathHOTPParams $ oathHOTPCounter ) )",
		&oc_oathHOTPToken },
	{ "( oath-ldap-oc:3.2 "
		"NAME 'oathTOTPToken' "
		"DESC 'OATH-LDAP: TOTP token' "
		"X-ORIGIN 'OATH-LDAP' "
		"AUXILIARY "
		"SUP oathToken "
		"MAY ( oathTOTPParams $ oathTOTPLastTimeStep $ oathTOTPTimeStepDrift ) )",
		&oc_oathTOTPToken },
	{ NULL }
};

typedef struct myval {
	ber_len_t mv_len;
	void *mv_val;
} myval;

static void
do_hmac( const void *hash, myval *key, myval *data, myval *out )
{
	TOTP_HMAC_CTX ctx;
	unsigned int digestLen;

	HMAC_setup( ctx, key->mv_val, key->mv_len, hash );
	HMAC_crunch( ctx, data->mv_val, data->mv_len );
	HMAC_finish( ctx, out->mv_val, digestLen );
	out->mv_len = digestLen;
}

#define MAX_DIGITS 8
static const int DIGITS_POWER[] = {
	1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000,
};

static const void *
otp_choose_mech( struct berval *oid )
{
	/* RFC 8018 OIDs */
	const struct berval oid_hmacwithSHA1 = BER_BVC("1.2.840.113549.2.7");
	const struct berval oid_hmacwithSHA224 = BER_BVC("1.2.840.113549.2.8");
	const struct berval oid_hmacwithSHA256 = BER_BVC("1.2.840.113549.2.9");
	const struct berval oid_hmacwithSHA384 = BER_BVC("1.2.840.113549.2.10");
	const struct berval oid_hmacwithSHA512 = BER_BVC("1.2.840.113549.2.11");

	if ( !ber_bvcmp( &oid_hmacwithSHA1, oid ) ) {
		return TOTP_SHA1;
	} else if ( !ber_bvcmp( &oid_hmacwithSHA224, oid ) ) {
		return TOTP_SHA224;
	} else if ( !ber_bvcmp( &oid_hmacwithSHA256, oid ) ) {
		return TOTP_SHA256;
	} else if ( !ber_bvcmp( &oid_hmacwithSHA384, oid ) ) {
		return TOTP_SHA384;
	} else if ( !ber_bvcmp( &oid_hmacwithSHA512, oid ) ) {
		return TOTP_SHA512;
	}

	Debug( LDAP_DEBUG_TRACE, "otp_choose_mech: "
			"hmac OID %s unsupported\n",
			oid->bv_val );
	return NULL;
}

static void
generate(
		struct berval *bv,
		uint64_t tval,
		int digits,
		struct berval *out,
		const void *mech )
{
	unsigned char digest[TOTP_SHA512_DIGEST_LENGTH];
	myval digval;
	myval key, data;
	unsigned char msg[8];
	int i, offset, res, otp;

#if WORDS_BIGENDIAN
	*(uint64_t *)msg = tval;
#else
	for ( i = 7; i >= 0; i-- ) {
		msg[i] = tval & 0xff;
		tval >>= 8;
	}
#endif

	key.mv_len = bv->bv_len;
	key.mv_val = bv->bv_val;

	data.mv_val = msg;
	data.mv_len = sizeof(msg);

	digval.mv_val = digest;
	digval.mv_len = sizeof(digest);
	do_hmac( mech, &key, &data, &digval );

	offset = digest[digval.mv_len - 1] & 0xf;
	res = ( (digest[offset] & 0x7f) << 24 ) |
			( ( digest[offset + 1] & 0xff ) << 16 ) |
			( ( digest[offset + 2] & 0xff ) << 8 ) |
			( digest[offset + 3] & 0xff );

	otp = res % DIGITS_POWER[digits];
	out->bv_len = snprintf( out->bv_val, out->bv_len, "%0*d", digits, otp );
}

static int
otp_bind_response( Operation *op, SlapReply *rs )
{
	if ( rs->sr_err == LDAP_SUCCESS ) {
		/* If the bind succeeded, return our result */
		rs->sr_err = LDAP_INVALID_CREDENTIALS;
	}
	return SLAP_CB_CONTINUE;
}

static long
otp_hotp( Operation *op, Entry *token )
{
	char outbuf[MAX_DIGITS + 1];
	Entry *params = NULL;
	Attribute *a;
	BerValue *secret, client_otp;
	const void *mech;
	long last_step = -1, found = -1;
	int i, otp_len, window;

	a = attr_find( token->e_attrs, ad_oathSecret );
	secret = &a->a_vals[0];

	a = attr_find( token->e_attrs, ad_oathHOTPCounter );
	if ( a && lutil_atol( &last_step, a->a_vals[0].bv_val ) != 0 ) {
		Debug( LDAP_DEBUG_ANY, "otp_hotp: "
				"could not parse oathHOTPCounter value %s\n",
				a->a_vals[0].bv_val );
		goto done;
	}

	a = attr_find( token->e_attrs, ad_oathHOTPParams );
	if ( !a ||
			be_entry_get_rw( op, &a->a_nvals[0], oc_oathHOTPParams, NULL, 0,
					&params ) ) {
		goto done;
	}

	a = attr_find( params->e_attrs, ad_oathOTPLength );
	if ( lutil_atoi( &otp_len, a->a_vals[0].bv_val ) != 0 ) {
		Debug( LDAP_DEBUG_ANY, "otp_hotp: "
				"could not parse oathOTPLength value %s\n",
				a->a_vals[0].bv_val );
		goto done;
	}
	if ( otp_len > MAX_DIGITS || op->orb_cred.bv_len < otp_len ) {
		/* Client didn't even send the token, fail immediately */
		goto done;
	}

	a = attr_find( params->e_attrs, ad_oathHOTPLookahead );
	if ( lutil_atoi( &window, a->a_vals[0].bv_val ) != 0 ) {
		Debug( LDAP_DEBUG_ANY, "otp_hotp: "
				"could not parse oathHOTPLookAhead value %s\n",
				a->a_vals[0].bv_val );
		goto done;
	}
	window++;

	a = attr_find( params->e_attrs, ad_oathHMACAlgorithm );
	if ( !(mech = otp_choose_mech( &a->a_vals[0] )) ) {
		goto done;
	}
	be_entry_release_r( op, params );
	params = NULL;

	/* We are provided "password" + "OTP", split accordingly */
	client_otp.bv_len = otp_len;
	client_otp.bv_val = op->orb_cred.bv_val + op->orb_cred.bv_len - otp_len;

	/* If check succeeds, advance the step counter accordingly */
	for ( i = 1; i <= window; i++ ) {
		BerValue out = { .bv_val = outbuf, .bv_len = sizeof(outbuf) };

		generate( secret, last_step + i, otp_len, &out, mech );
		if ( !ber_bvcmp( &out, &client_otp ) ) {
			found = last_step + i;
			/* Would we leak information if we stopped right now? */
		}
	}

	if ( found >= 0 ) {
		/* OTP check passed, trim the password */
		op->orb_cred.bv_len -= otp_len;
		Debug( LDAP_DEBUG_STATS, "%s HOTP token %s no. %ld redeemed\n",
				op->o_log_prefix, token->e_name.bv_val, found );
	}

done:
	memset( outbuf, 0, sizeof(outbuf) );
	if ( params ) {
		be_entry_release_r( op, params );
	}
	return found;
}

static long
otp_totp( Operation *op, Entry *token, long *drift )
{
	char outbuf[MAX_DIGITS + 1];
	Entry *params = NULL;
	Attribute *a;
	BerValue *secret, client_otp;
	const void *mech;
	long t, last_step = -1, found = -1, window = 0, old_drift;
	int i, otp_len, time_step;

	a = attr_find( token->e_attrs, ad_oathSecret );
	secret = &a->a_vals[0];

	a = attr_find( token->e_attrs, ad_oathTOTPLastTimeStep );
	if ( a && lutil_atol( &last_step, a->a_vals[0].bv_val ) != 0 ) {
		Debug( LDAP_DEBUG_ANY, "otp_totp: "
				"could not parse oathTOTPLastTimeStep value %s\n",
				a->a_vals[0].bv_val );
		goto done;
	}

	a = attr_find( token->e_attrs, ad_oathTOTPParams );
	if ( !a ||
			be_entry_get_rw( op, &a->a_nvals[0], oc_oathTOTPParams, NULL, 0,
					&params ) ) {
		goto done;
	}

	a = attr_find( params->e_attrs, ad_oathTOTPTimeStepPeriod );
	if ( lutil_atoi( &time_step, a->a_vals[0].bv_val ) != 0 ) {
		Debug( LDAP_DEBUG_ANY, "otp_totp: "
				"could not parse oathTOTPTimeStepPeriod value %s\n",
				a->a_vals[0].bv_val );
		goto done;
	}

	a = attr_find( params->e_attrs, ad_oathTOTPTimeStepWindow );
	if ( a && lutil_atol( &window, a->a_vals[0].bv_val ) != 0 ) {
		Debug( LDAP_DEBUG_ANY, "otp_totp: "
				"could not parse oathTOTPTimeStepWindow value %s\n",
				a->a_vals[0].bv_val );
		goto done;
	}

	a = attr_find( params->e_attrs, ad_oathTOTPTimeStepDrift );
	if ( a && lutil_atol( drift, a->a_vals[0].bv_val ) != 0 ) {
		Debug( LDAP_DEBUG_ANY, "otp_totp: "
				"could not parse oathTOTPTimeStepDrift value %s\n",
				a->a_vals[0].bv_val );
		goto done;
	}
	old_drift = *drift;
	t = op->o_time / time_step + *drift;

	a = attr_find( params->e_attrs, ad_oathOTPLength );
	if ( lutil_atoi( &otp_len, a->a_vals[0].bv_val ) != 0 ) {
		Debug( LDAP_DEBUG_ANY, "otp_totp: "
				"could not parse oathOTPLength value %s\n",
				a->a_vals[0].bv_val );
		goto done;
	}
	if ( otp_len > MAX_DIGITS || op->orb_cred.bv_len < otp_len ) {
		/* Client didn't even send the token, fail immediately */
		goto done;
	}

	a = attr_find( params->e_attrs, ad_oathHMACAlgorithm );
	if ( !(mech = otp_choose_mech( &a->a_vals[0] )) ) {
		goto done;
	}
	be_entry_release_r( op, params );
	params = NULL;

	/* We are provided "password" + "OTP", split accordingly */
	client_otp.bv_len = otp_len;
	client_otp.bv_val = op->orb_cred.bv_val + op->orb_cred.bv_len - otp_len;

	/* If check succeeds, advance the step counter accordingly */
	/* Negation of A001057 series that enumerates all integers:
	 * (0, -1, 1, -2, 2, ...) */
	for ( i = 0; i >= -window; i = ( i < 0 ) ? -i : ~i ) {
		BerValue out = { .bv_val = outbuf, .bv_len = sizeof(outbuf) };

		if ( t + i <= last_step ) continue;

		generate( secret, t + i, otp_len, &out, mech );
		if ( !ber_bvcmp( &out, &client_otp ) ) {
			found = t + i;
			*drift = old_drift + i;
			/* Would we leak information if we stopped right now? */
		}
	}

	/* OTP check passed, trim the password */
	if ( found >= 0 ) {
		assert( found > last_step );

		op->orb_cred.bv_len -= otp_len;
		Debug( LDAP_DEBUG_TRACE, "%s TOTP token %s redeemed with new drift of %ld\n",
				op->o_log_prefix, token->e_name.bv_val, *drift );
	}

done:
	memset( outbuf, 0, sizeof(outbuf) );
	if ( params ) {
		be_entry_release_r( op, params );
	}
	return found;
}

static int
otp_op_bind( Operation *op, SlapReply *rs )
{
	slap_overinst *on = (slap_overinst *)op->o_bd->bd_info;
	BerValue totpdn = BER_BVNULL, hotpdn = BER_BVNULL, ndn;
	Entry *user = NULL, *token = NULL;
	AttributeDescription *ad = NULL, *drift_ad = NULL;
	Attribute *a;
	long t = -1, drift = 0;
	int rc = SLAP_CB_CONTINUE;

	if ( op->oq_bind.rb_method != LDAP_AUTH_SIMPLE ) {
		return rc;
	}

	op->o_bd->bd_info = (BackendInfo *)on->on_info;

	if ( be_entry_get_rw( op, &op->o_req_ndn, NULL, NULL, 0, &user ) ) {
		goto done;
	}

	if ( !is_entry_objectclass_or_sub( user, oc_oathOTPUser ) ) {
		be_entry_release_r( op, user );
		goto done;
	}

	if ( (a = attr_find( user->e_attrs, ad_oathTOTPToken )) ) {
		ber_dupbv_x( &totpdn, &a->a_nvals[0], op->o_tmpmemctx );
	}

	if ( (a = attr_find( user->e_attrs, ad_oathHOTPToken )) ) {
		ber_dupbv_x( &hotpdn, &a->a_nvals[0], op->o_tmpmemctx );
	}
	be_entry_release_r( op, user );

	if ( !BER_BVISNULL( &totpdn ) &&
			be_entry_get_rw( op, &totpdn, oc_oathTOTPToken, ad_oathSecret, 0,
					&token ) == LDAP_SUCCESS ) {
		ndn = totpdn;
		ad = ad_oathTOTPLastTimeStep;
		drift_ad = ad_oathTOTPTimeStepDrift;
		t = otp_totp( op, token, &drift );
		be_entry_release_r( op, token );
		token = NULL;
	}
	if ( t < 0 && !BER_BVISNULL( &hotpdn ) &&
			be_entry_get_rw( op, &hotpdn, oc_oathHOTPToken, ad_oathSecret, 0,
					&token ) == LDAP_SUCCESS ) {
		ndn = hotpdn;
		ad = ad_oathHOTPCounter;
		t = otp_hotp( op, token );
		be_entry_release_r( op, token );
		token = NULL;
	}

	/* If check succeeds, advance the step counter and drift accordingly */
	if ( t >= 0 ) {
		char outbuf[32], drift_buf[32];
		Operation op2;
		Opheader oh;
		Modifications mod[2], *m = mod;
		SlapReply rs2 = { REP_RESULT };
		slap_callback cb = { .sc_response = &slap_null_cb };
		BerValue bv[2], bv_drift[2];

		bv[0].bv_val = outbuf;
		bv[0].bv_len = snprintf( bv[0].bv_val, sizeof(outbuf), "%ld", t );
		BER_BVZERO( &bv[1] );

		m->sml_numvals = 1;
		m->sml_values = bv;
		m->sml_nvalues = NULL;
		m->sml_desc = ad;
		m->sml_op = LDAP_MOD_REPLACE;
		m->sml_flags = SLAP_MOD_INTERNAL;

		if ( drift_ad ) {
			m->sml_next = &mod[1];

			bv_drift[0].bv_val = drift_buf;
			bv_drift[0].bv_len = snprintf(
					bv_drift[0].bv_val, sizeof(drift_buf), "%ld", drift );
			BER_BVZERO( &bv_drift[1] );

			m++;
			m->sml_numvals = 1;
			m->sml_values = bv_drift;
			m->sml_nvalues = NULL;
			m->sml_desc = drift_ad;
			m->sml_op = LDAP_MOD_REPLACE;
			m->sml_flags = SLAP_MOD_INTERNAL;
		}
		m->sml_next = NULL;

		op2 = *op;
		oh = *op->o_hdr;
		op2.o_hdr = &oh;

		op2.o_callback = &cb;

		op2.o_tag = LDAP_REQ_MODIFY;
		op2.orm_modlist = mod;
		op2.o_dn = op->o_bd->be_rootdn;
		op2.o_ndn = op->o_bd->be_rootndn;
		op2.o_req_dn = ndn;
		op2.o_req_ndn = ndn;
		op2.o_opid = -1;

		op2.o_bd->be_modify( &op2, &rs2 );
		if ( rs2.sr_err != LDAP_SUCCESS ) {
			rc = LDAP_OTHER;
			goto done;
		}
	} else {
		/* Client failed the bind, but we still have to pass it over to the
		 * backend and fail the Bind later */
		slap_callback *cb;
		cb = op->o_tmpcalloc( 1, sizeof(slap_callback), op->o_tmpmemctx );
		cb->sc_response = otp_bind_response;
		cb->sc_next = op->o_callback;
		op->o_callback = cb;
	}

done:
	if ( !BER_BVISNULL( &hotpdn ) ) {
		ber_memfree_x( hotpdn.bv_val, op->o_tmpmemctx );
	}
	if ( !BER_BVISNULL( &totpdn ) ) {
		ber_memfree_x( totpdn.bv_val, op->o_tmpmemctx );
	}
	op->o_bd->bd_info = (BackendInfo *)on;
	return rc;
}

static slap_overinst otp;

int
otp_initialize( void )
{
	ConfigArgs ca;
	char *argv[4];
	int i;

	otp.on_bi.bi_type = "otp";
	otp.on_bi.bi_op_bind = otp_op_bind;

	ca.argv = argv;
	argv[0] = "otp";
	ca.argv = argv;
	ca.argc = 3;
	ca.fname = argv[0];

	argv[3] = NULL;
	for ( i = 0; otp_oid[i].name; i++ ) {
		argv[1] = otp_oid[i].name;
		argv[2] = otp_oid[i].oid;
		parse_oidm( &ca, 0, NULL );
	}

	/* schema integration */
	for ( i = 0; otp_at[i].schema; i++ ) {
		if ( register_at( otp_at[i].schema, otp_at[i].adp, 0 ) ) {
			Debug( LDAP_DEBUG_ANY, "otp_initialize: "
					"register_at failed\n" );
			return -1;
		}
	}

	for ( i = 0; otp_oc[i].schema; i++ ) {
		if ( register_oc( otp_oc[i].schema, otp_oc[i].ocp, 0 ) ) {
			Debug( LDAP_DEBUG_ANY, "otp_initialize: "
					"register_oc failed\n" );
			return -1;
		}
	}

#if OPENSSL_VERSION_MAJOR >= 3
	evp_mac = EVP_MAC_fetch( NULL, "HMAC", "provider=default" );
#endif
	return overlay_register( &otp );
}

#if SLAPD_OVER_OTP == SLAPD_MOD_DYNAMIC
int
init_module( int argc, char *argv[] )
{
	return otp_initialize();
}
#endif /* SLAPD_OVER_OTP == SLAPD_MOD_DYNAMIC */

#endif /* defined(SLAPD_OVER_OTP) */