aboutsummaryrefslogtreecommitdiffstats
path: root/wpa_supplicant/eap_sim.c
blob: 43fd1873072c0326c1e429fafb802d9b0e33fd76 (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
/*
 * WPA Supplicant / EAP-SIM (draft-haverinen-pppext-eap-sim-13.txt)
 * Copyright (c) 2004-2005, Jouni Malinen <jkmaline@cc.hut.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "common.h"
#include "eap_i.h"
#include "wpa_supplicant.h"
#include "config_ssid.h"
#include "crypto.h"
#include "pcsc_funcs.h"
#include "eap_sim_common.h"


struct eap_sim_data {
	u8 *ver_list;
	size_t ver_list_len;
	int selected_version;
	int min_num_chal, num_chal;

	u8 kc[3][EAP_SIM_KC_LEN];
	u8 sres[3][EAP_SIM_SRES_LEN];
	u8 nonce_mt[EAP_SIM_NONCE_MT_LEN], nonce_s[EAP_SIM_NONCE_S_LEN];
	u8 mk[EAP_SIM_MK_LEN];
	u8 k_aut[EAP_SIM_K_AUT_LEN];
	u8 k_encr[EAP_SIM_K_ENCR_LEN];
	u8 msk[EAP_SIM_KEYING_DATA_LEN];
	u8 rand[3][GSM_RAND_LEN];

	int num_id_req, num_notification;
	u8 *pseudonym;
	size_t pseudonym_len;
	u8 *reauth_id;
	size_t reauth_id_len;
	int reauth;
	unsigned int counter, counter_too_small;
	u8 *last_eap_identity;
	size_t last_eap_identity_len;
	enum { CONTINUE, SUCCESS, FAILURE } state;
};


static void * eap_sim_init(struct eap_sm *sm)
{
	struct eap_sim_data *data;
	struct wpa_ssid *config = eap_get_config(sm);

	data = malloc(sizeof(*data));
	if (data == NULL)
		return NULL;
	memset(data, 0, sizeof(*data));

	if (hostapd_get_rand(data->nonce_mt, EAP_SIM_NONCE_MT_LEN)) {
		wpa_printf(MSG_WARNING, "EAP-SIM: Failed to get random data "
			   "for NONCE_MT");
		free(data);
		return NULL;
	}

	data->min_num_chal = 2;
	if (config && config->phase1) {
		char *pos = strstr(config->phase1, "sim_min_num_chal=");
		if (pos) {
			data->min_num_chal = atoi(pos + 17);
			if (data->min_num_chal < 2 || data->min_num_chal > 3) {
				wpa_printf(MSG_WARNING, "EAP-SIM: Invalid "
					   "sim_min_num_chal configuration "
					   "(%d, expected 2 or 3)",
					   data->min_num_chal);
				free(data);
				return NULL;
			}
			wpa_printf(MSG_DEBUG, "EAP-SIM: Set minimum number of "
				   "challenges to %d", data->min_num_chal);
		}
	}

	data->state = CONTINUE;

	return data;
}


static void eap_sim_deinit(struct eap_sm *sm, void *priv)
{
	struct eap_sim_data *data = priv;
	if (data) {
		free(data->ver_list);
		free(data->pseudonym);
		free(data->reauth_id);
		free(data->last_eap_identity);
		free(data);
	}
}


static int eap_sim_gsm_auth(struct eap_sm *sm, struct eap_sim_data *data)
{
	wpa_printf(MSG_DEBUG, "EAP-SIM: GSM authentication algorithm");
#ifdef PCSC_FUNCS
	if (scard_gsm_auth(sm->scard_ctx, data->rand[0],
			   data->sres[0], data->kc[0]) ||
	    scard_gsm_auth(sm->scard_ctx, data->rand[1],
			   data->sres[1], data->kc[1]) ||
	    (data->num_chal > 2 &&
	     scard_gsm_auth(sm->scard_ctx, data->rand[2],
			    data->sres[2], data->kc[2]))) {
		wpa_printf(MSG_DEBUG, "EAP-SIM: GSM SIM authentication could "
			   "not be completed");
		return -1;
	}
#else /* PCSC_FUNCS */
	/* These hardcoded Kc and SRES values are used for testing. RAND to
	 * KC/SREC mapping is very bogus as far as real authentication is
	 * concerned, but it is quite useful for cases where the AS is rotating
	 * the order of pre-configured values. */
	{
		int i;
		for (i = 0; i < data->num_chal; i++) {
			if (data->rand[i][0] == 0xaa) {
				memcpy(data->kc[i],
				       "\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7",
				       EAP_SIM_KC_LEN);
				memcpy(data->sres[i], "\xd1\xd2\xd3\xd4",
				       EAP_SIM_SRES_LEN);
			} else if (data->rand[i][0] == 0xbb) {
				memcpy(data->kc[i],
				       "\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7",
				       EAP_SIM_KC_LEN);
				memcpy(data->sres[i], "\xe1\xe2\xe3\xe4",
				       EAP_SIM_SRES_LEN);
			} else {
				memcpy(data->kc[i],
				       "\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7",
				       EAP_SIM_KC_LEN);
				memcpy(data->sres[i], "\xf1\xf2\xf3\xf4",
				       EAP_SIM_SRES_LEN);
			}
		}
	}
#endif /* PCSC_FUNCS */
	return 0;
}


static int eap_sim_supported_ver(struct eap_sim_data *data, int version)
{
	return version == EAP_SIM_VERSION;
}


#define CLEAR_PSEUDONYM	0x01
#define CLEAR_REAUTH_ID	0x02
#define CLEAR_EAP_ID	0x04

static void eap_sim_clear_identities(struct eap_sim_data *data, int id)
{
	wpa_printf(MSG_DEBUG, "EAP-SIM: forgetting old%s%s%s",
		   id & CLEAR_PSEUDONYM ? " pseudonym" : "",
		   id & CLEAR_REAUTH_ID ? " reauth_id" : "",
		   id & CLEAR_EAP_ID ? " eap_id" : "");
	if (id & CLEAR_PSEUDONYM) {
		free(data->pseudonym);
		data->pseudonym = NULL;
		data->pseudonym_len = 0;
	}
	if (id & CLEAR_REAUTH_ID) {
		free(data->reauth_id);
		data->reauth_id = NULL;
		data->reauth_id_len = 0;
	}
	if (id & CLEAR_EAP_ID) {
		free(data->last_eap_identity);
		data->last_eap_identity = NULL;
		data->last_eap_identity_len = 0;
	}
}


static int eap_sim_learn_ids(struct eap_sim_data *data,
			     struct eap_sim_attrs *attr)
{
	if (attr->next_pseudonym) {
		free(data->pseudonym);
		data->pseudonym = malloc(attr->next_pseudonym_len);
		if (data->pseudonym == NULL) {
			wpa_printf(MSG_INFO, "EAP-SIM: (encr) No memory for "
				   "next pseudonym");
			return -1;
		}
		memcpy(data->pseudonym, attr->next_pseudonym,
		       attr->next_pseudonym_len);
		data->pseudonym_len = attr->next_pseudonym_len;
		wpa_hexdump_ascii(MSG_DEBUG,
				  "EAP-SIM: (encr) AT_NEXT_PSEUDONYM",
				  data->pseudonym,
				  data->pseudonym_len);
	}

	if (attr->next_reauth_id) {
		free(data->reauth_id);
		data->reauth_id = malloc(attr->next_reauth_id_len);
		if (data->reauth_id == NULL) {
			wpa_printf(MSG_INFO, "EAP-SIM: (encr) No memory for "
				   "next reauth_id");
			return -1;
		}
		memcpy(data->reauth_id, attr->next_reauth_id,
		       attr->next_reauth_id_len);
		data->reauth_id_len = attr->next_reauth_id_len;
		wpa_hexdump_ascii(MSG_DEBUG,
				  "EAP-SIM: (encr) AT_NEXT_REAUTH_ID",
				  data->reauth_id,
				  data->reauth_id_len);
	}

	return 0;
}


static u8 * eap_sim_client_error(struct eap_sm *sm, struct eap_sim_data *data,
				 const struct eap_hdr *req,
				 size_t *respDataLen, int err)
{
	struct eap_sim_msg *msg;

	data->state = FAILURE;
	data->num_id_req = 0;
	data->num_notification = 0;

	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
			       EAP_TYPE_SIM, EAP_SIM_SUBTYPE_CLIENT_ERROR);
	eap_sim_msg_add(msg, EAP_SIM_AT_CLIENT_ERROR_CODE, err, NULL, 0);
	return eap_sim_msg_finish(msg, respDataLen, NULL, NULL, 0);
}


static u8 * eap_sim_response_start(struct eap_sm *sm,
				   struct eap_sim_data *data,
				   const struct eap_hdr *req,
				   size_t *respDataLen,
				   enum eap_sim_id_req id_req)
{
	struct wpa_ssid *config = eap_get_config(sm);
	u8 *identity = NULL;
	size_t identity_len = 0;
	struct eap_sim_msg *msg;

	data->reauth = 0;
	if (id_req == ANY_ID && data->reauth_id) {
		identity = data->reauth_id;
		identity_len = data->reauth_id_len;
		data->reauth = 1;
	} else if ((id_req == ANY_ID || id_req == FULLAUTH_ID) &&
		   data->pseudonym) {
		identity = data->pseudonym;
		identity_len = data->pseudonym_len;
		eap_sim_clear_identities(data, CLEAR_REAUTH_ID);
	} else if (id_req != NO_ID_REQ && config && config->identity) {
		identity = config->identity;
		identity_len = config->identity_len;
		eap_sim_clear_identities(data,
					 CLEAR_PSEUDONYM | CLEAR_REAUTH_ID);
	}
	if (id_req != NO_ID_REQ)
		eap_sim_clear_identities(data, CLEAR_EAP_ID);

	wpa_printf(MSG_DEBUG, "Generating EAP-SIM Start (id=%d)",
		   req->identifier);
	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
			       EAP_TYPE_SIM, EAP_SIM_SUBTYPE_START);
	wpa_hexdump(MSG_DEBUG, "   AT_NONCE_MT",
		    data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
	eap_sim_msg_add(msg, EAP_SIM_AT_NONCE_MT, 0,
			data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
	wpa_printf(MSG_DEBUG, "   AT_SELECTED_VERSION %d",
		   data->selected_version);
	eap_sim_msg_add(msg, EAP_SIM_AT_SELECTED_VERSION,
			data->selected_version, NULL, 0);

	if (identity) {
		wpa_hexdump_ascii(MSG_DEBUG, "   AT_IDENTITY",
				  identity, identity_len);
		eap_sim_msg_add(msg, EAP_SIM_AT_IDENTITY, identity_len,
				identity, identity_len);
	}

	return eap_sim_msg_finish(msg, respDataLen, NULL, NULL, 0);
}


static u8 * eap_sim_response_challenge(struct eap_sm *sm,
				       struct eap_sim_data *data,
				       const struct eap_hdr *req,
				       size_t *respDataLen)
{
	struct eap_sim_msg *msg;

	wpa_printf(MSG_DEBUG, "Generating EAP-SIM Challenge (id=%d)",
		   req->identifier);
	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
			       EAP_TYPE_SIM, EAP_SIM_SUBTYPE_CHALLENGE);
	wpa_printf(MSG_DEBUG, "   AT_MAC");
	eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
	return eap_sim_msg_finish(msg, respDataLen, data->k_aut,
				  (u8 *) data->sres,
				  data->num_chal * EAP_SIM_SRES_LEN);
}


static u8 * eap_sim_response_reauth(struct eap_sm *sm,
				    struct eap_sim_data *data,
				    const struct eap_hdr *req,
				    size_t *respDataLen, int counter_too_small)
{
	struct eap_sim_msg *msg;
	unsigned int counter;

	wpa_printf(MSG_DEBUG, "Generating EAP-SIM Reauthentication (id=%d)",
		   req->identifier);
	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
			       EAP_TYPE_SIM,
			       EAP_SIM_SUBTYPE_REAUTHENTICATION);
	wpa_printf(MSG_DEBUG, "   AT_IV");
	wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
	eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA);

	if (counter_too_small) {
		wpa_printf(MSG_DEBUG, "   *AT_COUNTER_TOO_SMALL");
		eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER_TOO_SMALL, 0, NULL, 0);
		counter = data->counter_too_small;
	} else
		counter = data->counter;

	wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", counter);
	eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0);

	if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) {
		wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
			   "AT_ENCR_DATA");
		eap_sim_msg_free(msg);
		return NULL;
	}
	wpa_printf(MSG_DEBUG, "   AT_MAC");
	eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
	return eap_sim_msg_finish(msg, respDataLen, data->k_aut, data->nonce_s,
				  EAP_SIM_NONCE_S_LEN);
}


static u8 * eap_sim_response_notification(struct eap_sm *sm,
					  struct eap_sim_data *data,
					  const struct eap_hdr *req,
					  size_t *respDataLen,
					  u16 notification)
{
	struct eap_sim_msg *msg;
	u8 *k_aut = (notification & 0x4000) == 0 ? data->k_aut : NULL;

	wpa_printf(MSG_DEBUG, "Generating EAP-SIM Notification (id=%d)",
		   req->identifier);
	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, req->identifier,
			       EAP_TYPE_SIM, EAP_SIM_SUBTYPE_NOTIFICATION);
	wpa_printf(MSG_DEBUG, "   AT_NOTIFICATION");
	eap_sim_msg_add(msg, EAP_SIM_AT_NOTIFICATION, notification, NULL, 0);
	if (k_aut && data->reauth) {
		wpa_printf(MSG_DEBUG, "   AT_IV");
		wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
		eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
					   EAP_SIM_AT_ENCR_DATA);
		wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", data->counter);
		eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
				NULL, 0);
		if (eap_sim_msg_add_encr_end(msg, data->k_encr,
					     EAP_SIM_AT_PADDING)) {
			wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
				   "AT_ENCR_DATA");
			eap_sim_msg_free(msg);
			return NULL;
		}
	}
	if (k_aut) {
		wpa_printf(MSG_DEBUG, "   AT_MAC");
		eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
	}
	return eap_sim_msg_finish(msg, respDataLen, k_aut, (u8 *) "", 0);
}


static u8 * eap_sim_process_start(struct eap_sm *sm, struct eap_sim_data *data,
				  const struct eap_hdr *req, size_t reqDataLen,
				  size_t *respDataLen,
				  struct eap_sim_attrs *attr)
{
	int i, selected_version = -1, id_error;
	u8 *pos;

	wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Start");
	if (attr->version_list == NULL) {
		wpa_printf(MSG_INFO, "EAP-SIM: No AT_VERSION_LIST in "
			   "SIM/Start");
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_UNSUPPORTED_VERSION);
	}

	free(data->ver_list);
	data->ver_list = malloc(attr->version_list_len);
	if (data->ver_list == NULL) {
		wpa_printf(MSG_DEBUG, "EAP-SIM: Failed to allocate "
			   "memory for version list");
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
	}
	memcpy(data->ver_list, attr->version_list, attr->version_list_len);
	data->ver_list_len = attr->version_list_len;
	pos = data->ver_list;
	for (i = 0; i < data->ver_list_len / 2; i++) {
		int ver = pos[0] * 256 + pos[1];
		pos += 2;
		if (eap_sim_supported_ver(data, ver)) {
			selected_version = ver;
			break;
		}
	}
	if (selected_version < 0) {
		wpa_printf(MSG_INFO, "EAP-SIM: Could not find a supported "
			   "version");
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_UNSUPPORTED_VERSION);
	}
	wpa_printf(MSG_DEBUG, "EAP-SIM: Selected Version %d",
		   selected_version);
	data->selected_version = selected_version;

	id_error = 0;
	switch (attr->id_req) {
	case NO_ID_REQ:
		break;
	case ANY_ID:
		if (data->num_id_req > 0)
			id_error++;
		data->num_id_req++;
		break;
	case FULLAUTH_ID:
		if (data->num_id_req > 1)
			id_error++;
		data->num_id_req++;
		break;
	case PERMANENT_ID:
		if (data->num_id_req > 2)
			id_error++;
		data->num_id_req++;
		break;
	}
	if (id_error) {
		wpa_printf(MSG_INFO, "EAP-SIM: Too many ID requests "
			   "used within one authentication");
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
	}

	return eap_sim_response_start(sm, data, req, respDataLen,
				      attr->id_req);
}


static u8 * eap_sim_process_challenge(struct eap_sm *sm,
				      struct eap_sim_data *data,
				      const struct eap_hdr *req,
				      size_t reqDataLen,
				      size_t *respDataLen,
				      struct eap_sim_attrs *attr)
{
	struct wpa_ssid *config = eap_get_config(sm);
	u8 *identity;
	size_t identity_len;
	struct eap_sim_attrs eattr;

	wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Challenge");
	data->reauth = 0;
	if (!attr->mac || !attr->rand) {
		wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
			   "did not include%s%s",
			   !attr->mac ? " AT_MAC" : "",
			   !attr->rand ? " AT_RAND" : "");
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
	}

	wpa_printf(MSG_DEBUG, "EAP-SIM: %lu challenges",
		   (unsigned long) attr->num_chal);
	if (attr->num_chal < data->min_num_chal) {
		wpa_printf(MSG_INFO, "EAP-SIM: Insufficient number of "
			   "challenges (%lu)", (unsigned long) attr->num_chal);
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_INSUFFICIENT_NUM_OF_CHAL);
	}
	if (attr->num_chal > 3) {
		wpa_printf(MSG_INFO, "EAP-SIM: Too many challenges "
			   "(%lu)", (unsigned long) attr->num_chal);
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
	}

	/* Verify that RANDs are different */
	if (memcmp(attr->rand, attr->rand + GSM_RAND_LEN,
		   GSM_RAND_LEN) == 0 ||
	    (attr->num_chal > 2 &&
	     (memcmp(attr->rand, attr->rand + 2 * GSM_RAND_LEN,
		     GSM_RAND_LEN) == 0 ||
	      memcmp(attr->rand + GSM_RAND_LEN,
		     attr->rand + 2 * GSM_RAND_LEN,
		     GSM_RAND_LEN) == 0))) {
		wpa_printf(MSG_INFO, "EAP-SIM: Same RAND used multiple times");
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_RAND_NOT_FRESH);
	}

	memcpy(data->rand, attr->rand, attr->num_chal * GSM_RAND_LEN);
	data->num_chal = attr->num_chal;
		
	if (eap_sim_gsm_auth(sm, data)) {
		wpa_printf(MSG_WARNING, "EAP-SIM: GSM authentication failed");
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
	}
	if (data->last_eap_identity) {
		identity = data->last_eap_identity;
		identity_len = data->last_eap_identity_len;
	} else if (data->pseudonym) {
		identity = data->pseudonym;
		identity_len = data->pseudonym_len;
	} else {
		identity = config->identity;
		identity_len = config->identity_len;
	}
	wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Selected identity for MK "
			  "derivation", identity, identity_len);
	eap_sim_derive_mk(identity, identity_len, data->nonce_mt,
			  data->selected_version, data->ver_list,
			  data->ver_list_len, data->num_chal,
			  (const u8 *) data->kc, data->mk);
	eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk);
	if (eap_sim_verify_mac(data->k_aut, (const u8 *) req, reqDataLen,
			       attr->mac, data->nonce_mt,
			       EAP_SIM_NONCE_MT_LEN)) {
		wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
			   "used invalid AT_MAC");
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
	}

	/* Old reauthentication and pseudonym identities must not be used
	 * anymore. In other words, if no new identities are received, full
	 * authentication will be used on next reauthentication. */
	eap_sim_clear_identities(data, CLEAR_PSEUDONYM | CLEAR_REAUTH_ID |
				 CLEAR_EAP_ID);

	if (attr->encr_data) {
		u8 *decrypted;
		decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
					       attr->encr_data_len, attr->iv,
					       &eattr, 0);
		if (decrypted == NULL) {
			return eap_sim_client_error(
				sm, data, req, respDataLen,
				EAP_SIM_UNABLE_TO_PROCESS_PACKET);
		}
		eap_sim_learn_ids(data, &eattr);
		free(decrypted);
	}

	if (data->state != FAILURE)
		data->state = SUCCESS;

	data->num_id_req = 0;
	data->num_notification = 0;
	/* draft-haverinen-pppext-eap-sim-13.txt specifies that counter
	 * is initialized to one after fullauth, but initializing it to
	 * zero makes it easier to implement reauth verification. */
	data->counter = 0;
	return eap_sim_response_challenge(sm, data, req, respDataLen);
}


static int eap_sim_process_notification_reauth(struct eap_sim_data *data,
					       const struct eap_hdr *req,
					       size_t reqDataLen,
					       struct eap_sim_attrs *attr)
{
	struct eap_sim_attrs eattr;
	u8 *decrypted;

	if (attr->encr_data == NULL || attr->iv == NULL) {
		wpa_printf(MSG_WARNING, "EAP-SIM: Notification message after "
			   "reauth did not include encrypted data");
		return -1;
	}

	decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
				       attr->encr_data_len, attr->iv, &eattr,
				       0);
	if (decrypted == NULL) {
		wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
			   "data from notification message");
		return -1;
	}

	if (eattr.counter != data->counter) {
		wpa_printf(MSG_WARNING, "EAP-SIM: Counter in notification "
			   "message does not match with counter in reauth "
			   "message");
		free(decrypted);
		return -1;
	}

	free(decrypted);
	return 0;
}


static int eap_sim_process_notification_auth(struct eap_sim_data *data,
					     const struct eap_hdr *req,
					     size_t reqDataLen,
					     struct eap_sim_attrs *attr)
{
	if (attr->mac == NULL) {
		wpa_printf(MSG_INFO, "EAP-SIM: no AT_MAC in after_auth "
			   "Notification message");
		return -1;
	}

	if (eap_sim_verify_mac(data->k_aut, (u8 *) req, reqDataLen, attr->mac,
			       (u8 *) "", 0)) {
		wpa_printf(MSG_WARNING, "EAP-SIM: Notification message "
			   "used invalid AT_MAC");
		return -1;
	}

	if (data->reauth &&
	    eap_sim_process_notification_reauth(data, req, reqDataLen, attr)) {
		wpa_printf(MSG_WARNING, "EAP-SIM: Invalid notification "
			   "message after reauth");
		return -1;
	}

	return 0;
}


static u8 * eap_sim_process_notification(struct eap_sm *sm,
					 struct eap_sim_data *data,
					 const struct eap_hdr *req,
					 size_t reqDataLen,
					 size_t *respDataLen,
					 struct eap_sim_attrs *attr)
{
	wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Notification");
	if (data->num_notification > 0) {
		wpa_printf(MSG_INFO, "EAP-SIM: too many notification "
			   "rounds (only one allowed)");
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
	}
	data->num_notification++;
	if (attr->notification == -1) {
		wpa_printf(MSG_INFO, "EAP-SIM: no AT_NOTIFICATION in "
			   "Notification message");
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
	}

	if ((attr->notification & 0x4000) == 0 &&
	    eap_sim_process_notification_auth(data, req, reqDataLen, attr)) {
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
	}

	eap_sim_report_notification(sm->msg_ctx, attr->notification, 0);
	if (attr->notification >= 0 && attr->notification < 32768) {
		data->state = FAILURE;
	}
	return eap_sim_response_notification(sm, data, req, respDataLen,
					     attr->notification);
}


static u8 * eap_sim_process_reauthentication(struct eap_sm *sm,
					     struct eap_sim_data *data,
					     const struct eap_hdr *req,
					     size_t reqDataLen,
					     size_t *respDataLen,
					     struct eap_sim_attrs *attr)
{
	struct eap_sim_attrs eattr;
	u8 *decrypted;

	wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Reauthentication");

	if (data->reauth_id == NULL) {
		wpa_printf(MSG_WARNING, "EAP-SIM: Server is trying "
			   "reauthentication, but no reauth_id available");
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
	}

	data->reauth = 1;
	if (eap_sim_verify_mac(data->k_aut, (const u8 *) req, reqDataLen,
			       attr->mac, (u8 *) "", 0)) {
		wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
			   "did not have valid AT_MAC");
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
	}

	if (attr->encr_data == NULL || attr->iv == NULL) {
		wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
			   "message did not include encrypted data");
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
	}

	decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
				       attr->encr_data_len, attr->iv, &eattr,
				       0);
	if (decrypted == NULL) {
		wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
			   "data from reauthentication message");
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
	}

	if (eattr.nonce_s == NULL || eattr.counter < 0) {
		wpa_printf(MSG_INFO, "EAP-SIM: (encr) No%s%s in reauth packet",
			   !eattr.nonce_s ? " AT_NONCE_S" : "",
			   eattr.counter < 0 ? " AT_COUNTER" : "");
		free(decrypted);
		return eap_sim_client_error(sm, data, req, respDataLen,
					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
	}

	if (eattr.counter <= data->counter) {
		wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid counter "
			   "(%d <= %d)", eattr.counter, data->counter);
		data->counter_too_small = eattr.counter;
		/* Reply using Re-auth w/ AT_COUNTER_TOO_SMALL. The current
		 * reauth_id must not be used to start a new reauthentication.
		 * However, since it was used in the last EAP-Response-Identity
		 * packet, it has to saved for the following fullauth to be
		 * used in MK derivation. */
		free(data->last_eap_identity);
		data->last_eap_identity = data->reauth_id;
		data->last_eap_identity_len = data->reauth_id_len;
		data->reauth_id = NULL;
		data->reauth_id_len = 0;
		free(decrypted);
		return eap_sim_response_reauth(sm, data, req, respDataLen, 1);
	}
	data->counter = eattr.counter;

	memcpy(data->nonce_s, eattr.nonce_s, EAP_SIM_NONCE_S_LEN);
	wpa_hexdump(MSG_DEBUG, "EAP-SIM: (encr) AT_NONCE_S",
		    data->nonce_s, EAP_SIM_NONCE_S_LEN);

	eap_sim_derive_keys_reauth(data->counter,
				   data->reauth_id, data->reauth_id_len,
				   data->nonce_s, data->mk, data->msk);
	eap_sim_clear_identities(data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
	eap_sim_learn_ids(data, &eattr);

	if (data->state != FAILURE)
		data->state = SUCCESS;

	data->num_id_req = 0;
	data->num_notification = 0;
	if (data->counter > EAP_SIM_MAX_FAST_REAUTHS) {
		wpa_printf(MSG_DEBUG, "EAP-SIM: Maximum number of "
			   "fast reauths performed - force fullauth");
		eap_sim_clear_identities(data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
	}
	free(decrypted);
	return eap_sim_response_reauth(sm, data, req, respDataLen, 0);
}


static u8 * eap_sim_process(struct eap_sm *sm, void *priv,
			    struct eap_method_ret *ret,
			    const u8 *reqData, size_t reqDataLen,
			    size_t *respDataLen)
{
	struct eap_sim_data *data = priv;
	struct wpa_ssid *config = eap_get_config(sm);
	const struct eap_hdr *req;
	u8 subtype, *res;
	const u8 *pos;
	struct eap_sim_attrs attr;
	size_t len;

	wpa_hexdump(MSG_DEBUG, "EAP-SIM: EAP data", reqData, reqDataLen);
	if (config == NULL || config->identity == NULL) {
		wpa_printf(MSG_INFO, "EAP-SIM: Identity not configured");
		eap_sm_request_identity(sm, config);
		ret->ignore = TRUE;
		return NULL;
	}

	pos = eap_hdr_validate(EAP_TYPE_SIM, reqData, reqDataLen, &len);
	if (pos == NULL || len < 1) {
		ret->ignore = TRUE;
		return NULL;
	}
	req = (const struct eap_hdr *) reqData;
	len = be_to_host16(req->length);

	ret->ignore = FALSE;
	ret->methodState = METHOD_MAY_CONT;
	ret->decision = DECISION_FAIL;
	ret->allowNotifications = TRUE;

	subtype = *pos++;
	wpa_printf(MSG_DEBUG, "EAP-SIM: Subtype=%d", subtype);
	pos += 2; /* Reserved */

	if (eap_sim_parse_attr(pos, reqData + len, &attr, 0, 0)) {
		res = eap_sim_client_error(sm, data, req, respDataLen,
					   EAP_SIM_UNABLE_TO_PROCESS_PACKET);
		goto done;
	}

	switch (subtype) {
	case EAP_SIM_SUBTYPE_START:
		res = eap_sim_process_start(sm, data, req, len,
					    respDataLen, &attr);
		break;
	case EAP_SIM_SUBTYPE_CHALLENGE:
		res = eap_sim_process_challenge(sm, data, req, len,
						respDataLen, &attr);
		break;
	case EAP_SIM_SUBTYPE_NOTIFICATION:
		res = eap_sim_process_notification(sm, data, req, len,
						   respDataLen, &attr);
		break;
	case EAP_SIM_SUBTYPE_REAUTHENTICATION:
		res = eap_sim_process_reauthentication(sm, data, req, len,
						       respDataLen, &attr);
		break;
	case EAP_SIM_SUBTYPE_CLIENT_ERROR:
		wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Client-Error");
		res = eap_sim_client_error(sm, data, req, respDataLen,
					   EAP_SIM_UNABLE_TO_PROCESS_PACKET);
		break;
	default:
		wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown subtype=%d", subtype);
		res = eap_sim_client_error(sm, data, req, respDataLen,
					   EAP_SIM_UNABLE_TO_PROCESS_PACKET);
		break;
	}

done:
	if (data->state == FAILURE) {
		ret->decision = DECISION_FAIL;
		ret->methodState = METHOD_DONE;
	} else if (data->state == SUCCESS) {
		ret->decision = DECISION_COND_SUCC;
		ret->methodState = METHOD_DONE;
	}

	if (ret->methodState == METHOD_DONE) {
		ret->allowNotifications = FALSE;
	}

	return res;
}


static Boolean eap_sim_has_reauth_data(struct eap_sm *sm, void *priv)
{
	struct eap_sim_data *data = priv;
	return data->pseudonym || data->reauth_id;
}


static void eap_sim_deinit_for_reauth(struct eap_sm *sm, void *priv)
{
	struct eap_sim_data *data = priv;
	eap_sim_clear_identities(data, CLEAR_EAP_ID);
}


static void * eap_sim_init_for_reauth(struct eap_sm *sm, void *priv)
{
	struct eap_sim_data *data = priv;
	if (hostapd_get_rand(data->nonce_mt, EAP_SIM_NONCE_MT_LEN)) {
		wpa_printf(MSG_WARNING, "EAP-SIM: Failed to get random data "
			   "for NONCE_MT");
		free(data);
		return NULL;
	}
	data->num_id_req = 0;
	data->num_notification = 0;
	data->state = CONTINUE;
	return priv;
}


static const u8 * eap_sim_get_identity(struct eap_sm *sm, void *priv,
				       size_t *len)
{
	struct eap_sim_data *data = priv;

	if (data->reauth_id) {
		*len = data->reauth_id_len;
		return data->reauth_id;
	}

	if (data->pseudonym) {
		*len = data->pseudonym_len;
		return data->pseudonym;
	}

	return NULL;
}


static Boolean eap_sim_isKeyAvailable(struct eap_sm *sm, void *priv)
{
	struct eap_sim_data *data = priv;
	return data->state == SUCCESS;
}


static u8 * eap_sim_getKey(struct eap_sm *sm, void *priv, size_t *len)
{
	struct eap_sim_data *data = priv;
	u8 *key;

	if (data->state != SUCCESS)
		return NULL;

	key = malloc(EAP_SIM_KEYING_DATA_LEN);
	if (key == NULL)
		return NULL;

	*len = EAP_SIM_KEYING_DATA_LEN;
	memcpy(key, data->msk, EAP_SIM_KEYING_DATA_LEN);

	return key;
}


const struct eap_method eap_method_sim =
{
	.method = EAP_TYPE_SIM,
	.name = "SIM",
	.init = eap_sim_init,
	.deinit = eap_sim_deinit,
	.process = eap_sim_process,
	.isKeyAvailable = eap_sim_isKeyAvailable,
	.getKey = eap_sim_getKey,
	.has_reauth_data = eap_sim_has_reauth_data,
	.deinit_for_reauth = eap_sim_deinit_for_reauth,
	.init_for_reauth = eap_sim_init_for_reauth,
	.get_identity = eap_sim_get_identity,
};