1/*
2 * EAP peer method: EAP-AKA (RFC 4187) and EAP-AKA' (RFC 5448)
3 * Copyright (c) 2004-2012, Jouni Malinen <j@w1.fi>
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9#include "includes.h"
10
11#include "common.h"
12#include "pcsc_funcs.h"
13#include "crypto/crypto.h"
14#include "crypto/sha1.h"
15#include "crypto/sha256.h"
16#include "crypto/milenage.h"
17#include "eap_common/eap_sim_common.h"
18#include "eap_config.h"
19#include "eap_i.h"
20
21
22struct eap_aka_data {
23	u8 ik[EAP_AKA_IK_LEN], ck[EAP_AKA_CK_LEN], res[EAP_AKA_RES_MAX_LEN];
24	size_t res_len;
25	u8 nonce_s[EAP_SIM_NONCE_S_LEN];
26	u8 mk[EAP_SIM_MK_LEN];
27	u8 k_aut[EAP_AKA_PRIME_K_AUT_LEN];
28	u8 k_encr[EAP_SIM_K_ENCR_LEN];
29	u8 k_re[EAP_AKA_PRIME_K_RE_LEN]; /* EAP-AKA' only */
30	u8 msk[EAP_SIM_KEYING_DATA_LEN];
31	u8 emsk[EAP_EMSK_LEN];
32	u8 rand[EAP_AKA_RAND_LEN], autn[EAP_AKA_AUTN_LEN];
33	u8 auts[EAP_AKA_AUTS_LEN];
34
35	int num_id_req, num_notification;
36	u8 *pseudonym;
37	size_t pseudonym_len;
38	u8 *reauth_id;
39	size_t reauth_id_len;
40	int reauth;
41	unsigned int counter, counter_too_small;
42	u8 *last_eap_identity;
43	size_t last_eap_identity_len;
44	enum {
45		CONTINUE, RESULT_SUCCESS, SUCCESS, FAILURE
46	} state;
47
48	struct wpabuf *id_msgs;
49	int prev_id;
50	int result_ind, use_result_ind;
51	int use_pseudonym;
52	u8 eap_method;
53	u8 *network_name;
54	size_t network_name_len;
55	u16 kdf;
56	int kdf_negotiation;
57};
58
59
60#ifndef CONFIG_NO_STDOUT_DEBUG
61static const char * eap_aka_state_txt(int state)
62{
63	switch (state) {
64	case CONTINUE:
65		return "CONTINUE";
66	case RESULT_SUCCESS:
67		return "RESULT_SUCCESS";
68	case SUCCESS:
69		return "SUCCESS";
70	case FAILURE:
71		return "FAILURE";
72	default:
73		return "?";
74	}
75}
76#endif /* CONFIG_NO_STDOUT_DEBUG */
77
78
79static void eap_aka_state(struct eap_aka_data *data, int state)
80{
81	wpa_printf(MSG_DEBUG, "EAP-AKA: %s -> %s",
82		   eap_aka_state_txt(data->state),
83		   eap_aka_state_txt(state));
84	data->state = state;
85}
86
87
88static void * eap_aka_init(struct eap_sm *sm)
89{
90	struct eap_aka_data *data;
91	const char *phase1 = eap_get_config_phase1(sm);
92	struct eap_peer_config *config = eap_get_config(sm);
93
94	data = os_zalloc(sizeof(*data));
95	if (data == NULL)
96		return NULL;
97
98	data->eap_method = EAP_TYPE_AKA;
99
100	eap_aka_state(data, CONTINUE);
101	data->prev_id = -1;
102
103	data->result_ind = phase1 && os_strstr(phase1, "result_ind=1") != NULL;
104
105	data->use_pseudonym = !sm->init_phase2;
106	if (config && config->anonymous_identity && data->use_pseudonym) {
107		data->pseudonym = os_malloc(config->anonymous_identity_len);
108		if (data->pseudonym) {
109			os_memcpy(data->pseudonym, config->anonymous_identity,
110				  config->anonymous_identity_len);
111			data->pseudonym_len = config->anonymous_identity_len;
112		}
113	}
114
115	return data;
116}
117
118
119#ifdef EAP_AKA_PRIME
120static void * eap_aka_prime_init(struct eap_sm *sm)
121{
122	struct eap_aka_data *data = eap_aka_init(sm);
123	if (data == NULL)
124		return NULL;
125	data->eap_method = EAP_TYPE_AKA_PRIME;
126	return data;
127}
128#endif /* EAP_AKA_PRIME */
129
130
131static void eap_aka_clear_keys(struct eap_aka_data *data, int reauth)
132{
133	if (!reauth) {
134		os_memset(data->mk, 0, EAP_SIM_MK_LEN);
135		os_memset(data->k_aut, 0, EAP_AKA_PRIME_K_AUT_LEN);
136		os_memset(data->k_encr, 0, EAP_SIM_K_ENCR_LEN);
137		os_memset(data->k_re, 0, EAP_AKA_PRIME_K_RE_LEN);
138	}
139	os_memset(data->msk, 0, EAP_SIM_KEYING_DATA_LEN);
140	os_memset(data->emsk, 0, EAP_EMSK_LEN);
141	os_memset(data->autn, 0, EAP_AKA_AUTN_LEN);
142	os_memset(data->auts, 0, EAP_AKA_AUTS_LEN);
143}
144
145
146static void eap_aka_deinit(struct eap_sm *sm, void *priv)
147{
148	struct eap_aka_data *data = priv;
149	if (data) {
150		os_free(data->pseudonym);
151		os_free(data->reauth_id);
152		os_free(data->last_eap_identity);
153		wpabuf_free(data->id_msgs);
154		os_free(data->network_name);
155		eap_aka_clear_keys(data, 0);
156		os_free(data);
157	}
158}
159
160
161static int eap_aka_ext_sim_req(struct eap_sm *sm, struct eap_aka_data *data)
162{
163	char req[200], *pos, *end;
164
165	wpa_printf(MSG_DEBUG, "EAP-AKA: Use external USIM processing");
166	pos = req;
167	end = pos + sizeof(req);
168	pos += os_snprintf(pos, end - pos, "UMTS-AUTH");
169	pos += os_snprintf(pos, end - pos, ":");
170	pos += wpa_snprintf_hex(pos, end - pos, data->rand, EAP_AKA_RAND_LEN);
171	pos += os_snprintf(pos, end - pos, ":");
172	wpa_snprintf_hex(pos, end - pos, data->autn, EAP_AKA_AUTN_LEN);
173
174	eap_sm_request_sim(sm, req);
175	return 1;
176}
177
178
179static int eap_aka_ext_sim_result(struct eap_sm *sm, struct eap_aka_data *data,
180				  struct eap_peer_config *conf)
181{
182	char *resp, *pos;
183
184	wpa_printf(MSG_DEBUG,
185		   "EAP-AKA: Use result from external USIM processing");
186
187	resp = conf->external_sim_resp;
188	conf->external_sim_resp = NULL;
189
190	if (os_strncmp(resp, "UMTS-AUTS:", 10) == 0) {
191		pos = resp + 10;
192		if (hexstr2bin(pos, data->auts, EAP_AKA_AUTS_LEN) < 0)
193			goto invalid;
194		wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: AUTS", data->auts,
195				EAP_AKA_AUTS_LEN);
196		os_free(resp);
197		return -2;
198	}
199
200	if (os_strncmp(resp, "UMTS-AUTH:", 10) != 0) {
201		wpa_printf(MSG_DEBUG, "EAP-AKA: Unrecognized external USIM processing response");
202		os_free(resp);
203		return -1;
204	}
205
206	pos = resp + 10;
207	wpa_hexdump(MSG_DEBUG, "EAP-AKA: RAND", data->rand, EAP_AKA_RAND_LEN);
208
209	if (hexstr2bin(pos, data->ik, EAP_AKA_IK_LEN) < 0)
210		goto invalid;
211	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: IK", data->ik, EAP_AKA_IK_LEN);
212	pos += EAP_AKA_IK_LEN * 2;
213	if (*pos != ':')
214		goto invalid;
215	pos++;
216
217	if (hexstr2bin(pos, data->ck, EAP_AKA_CK_LEN) < 0)
218		goto invalid;
219	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: CK", data->ck, EAP_AKA_CK_LEN);
220	pos += EAP_AKA_CK_LEN * 2;
221	if (*pos != ':')
222		goto invalid;
223	pos++;
224
225	data->res_len = os_strlen(pos) / 2;
226	if (data->res_len > EAP_AKA_RES_MAX_LEN) {
227		data->res_len = 0;
228		goto invalid;
229	}
230	if (hexstr2bin(pos, data->res, data->res_len) < 0)
231		goto invalid;
232	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: RES", data->res, data->res_len);
233
234	os_free(resp);
235	return 0;
236
237invalid:
238	wpa_printf(MSG_DEBUG, "EAP-AKA: Invalid external USIM processing UMTS-AUTH response");
239	os_free(resp);
240	return -1;
241}
242
243
244static int eap_aka_umts_auth(struct eap_sm *sm, struct eap_aka_data *data)
245{
246	struct eap_peer_config *conf;
247
248	wpa_printf(MSG_DEBUG, "EAP-AKA: UMTS authentication algorithm");
249
250	conf = eap_get_config(sm);
251	if (conf == NULL)
252		return -1;
253
254	if (sm->external_sim) {
255		if (conf->external_sim_resp)
256			return eap_aka_ext_sim_result(sm, data, conf);
257		else
258			return eap_aka_ext_sim_req(sm, data);
259	}
260
261	if (conf->pcsc) {
262		return scard_umts_auth(sm->scard_ctx, data->rand,
263				       data->autn, data->res, &data->res_len,
264				       data->ik, data->ck, data->auts);
265	}
266
267#ifdef CONFIG_USIM_SIMULATOR
268	if (conf->password) {
269		u8 opc[16], k[16], sqn[6];
270		const char *pos;
271		wpa_printf(MSG_DEBUG, "EAP-AKA: Use internal Milenage "
272			   "implementation for UMTS authentication");
273		if (conf->password_len < 78) {
274			wpa_printf(MSG_DEBUG, "EAP-AKA: invalid Milenage "
275				   "password");
276			return -1;
277		}
278		pos = (const char *) conf->password;
279		if (hexstr2bin(pos, k, 16))
280			return -1;
281		pos += 32;
282		if (*pos != ':')
283			return -1;
284		pos++;
285
286		if (hexstr2bin(pos, opc, 16))
287			return -1;
288		pos += 32;
289		if (*pos != ':')
290			return -1;
291		pos++;
292
293		if (hexstr2bin(pos, sqn, 6))
294			return -1;
295
296		return milenage_check(opc, k, sqn, data->rand, data->autn,
297				      data->ik, data->ck,
298				      data->res, &data->res_len, data->auts);
299	}
300#endif /* CONFIG_USIM_SIMULATOR */
301
302#ifdef CONFIG_USIM_HARDCODED
303	wpa_printf(MSG_DEBUG, "EAP-AKA: Use hardcoded Kc and SRES values for "
304		   "testing");
305
306	/* These hardcoded Kc and SRES values are used for testing.
307	 * Could consider making them configurable. */
308	os_memset(data->res, '2', EAP_AKA_RES_MAX_LEN);
309	data->res_len = EAP_AKA_RES_MAX_LEN;
310	os_memset(data->ik, '3', EAP_AKA_IK_LEN);
311	os_memset(data->ck, '4', EAP_AKA_CK_LEN);
312	{
313		u8 autn[EAP_AKA_AUTN_LEN];
314		os_memset(autn, '1', EAP_AKA_AUTN_LEN);
315		if (os_memcmp_const(autn, data->autn, EAP_AKA_AUTN_LEN) != 0) {
316			wpa_printf(MSG_WARNING, "EAP-AKA: AUTN did not match "
317				   "with expected value");
318			return -1;
319		}
320	}
321#if 0
322	{
323		static int test_resync = 1;
324		if (test_resync) {
325			/* Test Resynchronization */
326			test_resync = 0;
327			return -2;
328		}
329	}
330#endif
331	return 0;
332
333#else /* CONFIG_USIM_HARDCODED */
334
335	wpa_printf(MSG_DEBUG, "EAP-AKA: No UMTS authentication algorithm "
336		   "enabled");
337	return -1;
338
339#endif /* CONFIG_USIM_HARDCODED */
340}
341
342
343#define CLEAR_PSEUDONYM	0x01
344#define CLEAR_REAUTH_ID	0x02
345#define CLEAR_EAP_ID	0x04
346
347static void eap_aka_clear_identities(struct eap_sm *sm,
348				     struct eap_aka_data *data, int id)
349{
350	if ((id & CLEAR_PSEUDONYM) && data->pseudonym) {
351		wpa_printf(MSG_DEBUG, "EAP-AKA: forgetting old pseudonym");
352		os_free(data->pseudonym);
353		data->pseudonym = NULL;
354		data->pseudonym_len = 0;
355		if (data->use_pseudonym)
356			eap_set_anon_id(sm, NULL, 0);
357	}
358	if ((id & CLEAR_REAUTH_ID) && data->reauth_id) {
359		wpa_printf(MSG_DEBUG, "EAP-AKA: forgetting old reauth_id");
360		os_free(data->reauth_id);
361		data->reauth_id = NULL;
362		data->reauth_id_len = 0;
363	}
364	if ((id & CLEAR_EAP_ID) && data->last_eap_identity) {
365		wpa_printf(MSG_DEBUG, "EAP-AKA: forgetting old eap_id");
366		os_free(data->last_eap_identity);
367		data->last_eap_identity = NULL;
368		data->last_eap_identity_len = 0;
369	}
370}
371
372
373static int eap_aka_learn_ids(struct eap_sm *sm, struct eap_aka_data *data,
374			     struct eap_sim_attrs *attr)
375{
376	if (attr->next_pseudonym) {
377		const u8 *identity = NULL;
378		size_t identity_len = 0;
379		const u8 *realm = NULL;
380		size_t realm_len = 0;
381
382		wpa_hexdump_ascii(MSG_DEBUG,
383				  "EAP-AKA: (encr) AT_NEXT_PSEUDONYM",
384				  attr->next_pseudonym,
385				  attr->next_pseudonym_len);
386		os_free(data->pseudonym);
387		/* Look for the realm of the permanent identity */
388		identity = eap_get_config_identity(sm, &identity_len);
389		if (identity) {
390			for (realm = identity, realm_len = identity_len;
391			     realm_len > 0; realm_len--, realm++) {
392				if (*realm == '@')
393					break;
394			}
395		}
396		data->pseudonym = os_malloc(attr->next_pseudonym_len +
397					    realm_len);
398		if (data->pseudonym == NULL) {
399			wpa_printf(MSG_INFO, "EAP-AKA: (encr) No memory for "
400				   "next pseudonym");
401			data->pseudonym_len = 0;
402			return -1;
403		}
404		os_memcpy(data->pseudonym, attr->next_pseudonym,
405			  attr->next_pseudonym_len);
406		if (realm_len) {
407			os_memcpy(data->pseudonym + attr->next_pseudonym_len,
408				  realm, realm_len);
409		}
410		data->pseudonym_len = attr->next_pseudonym_len + realm_len;
411		if (data->use_pseudonym)
412			eap_set_anon_id(sm, data->pseudonym,
413					data->pseudonym_len);
414	}
415
416	if (attr->next_reauth_id) {
417		os_free(data->reauth_id);
418		data->reauth_id = os_malloc(attr->next_reauth_id_len);
419		if (data->reauth_id == NULL) {
420			wpa_printf(MSG_INFO, "EAP-AKA: (encr) No memory for "
421				   "next reauth_id");
422			data->reauth_id_len = 0;
423			return -1;
424		}
425		os_memcpy(data->reauth_id, attr->next_reauth_id,
426			  attr->next_reauth_id_len);
427		data->reauth_id_len = attr->next_reauth_id_len;
428		wpa_hexdump_ascii(MSG_DEBUG,
429				  "EAP-AKA: (encr) AT_NEXT_REAUTH_ID",
430				  data->reauth_id,
431				  data->reauth_id_len);
432	}
433
434	return 0;
435}
436
437
438static int eap_aka_add_id_msg(struct eap_aka_data *data,
439			      const struct wpabuf *msg)
440{
441	if (msg == NULL)
442		return -1;
443
444	if (data->id_msgs == NULL) {
445		data->id_msgs = wpabuf_dup(msg);
446		return data->id_msgs == NULL ? -1 : 0;
447	}
448
449	if (wpabuf_resize(&data->id_msgs, wpabuf_len(msg)) < 0)
450		return -1;
451	wpabuf_put_buf(data->id_msgs, msg);
452
453	return 0;
454}
455
456
457static void eap_aka_add_checkcode(struct eap_aka_data *data,
458				  struct eap_sim_msg *msg)
459{
460	const u8 *addr;
461	size_t len;
462	u8 hash[SHA256_MAC_LEN];
463
464	wpa_printf(MSG_DEBUG, "   AT_CHECKCODE");
465
466	if (data->id_msgs == NULL) {
467		/*
468		 * No EAP-AKA/Identity packets were exchanged - send empty
469		 * checkcode.
470		 */
471		eap_sim_msg_add(msg, EAP_SIM_AT_CHECKCODE, 0, NULL, 0);
472		return;
473	}
474
475	/* Checkcode is SHA1/SHA256 hash over all EAP-AKA/Identity packets. */
476	addr = wpabuf_head(data->id_msgs);
477	len = wpabuf_len(data->id_msgs);
478	wpa_hexdump(MSG_MSGDUMP, "EAP-AKA: AT_CHECKCODE data", addr, len);
479#ifdef EAP_AKA_PRIME
480	if (data->eap_method == EAP_TYPE_AKA_PRIME)
481		sha256_vector(1, &addr, &len, hash);
482	else
483#endif /* EAP_AKA_PRIME */
484		sha1_vector(1, &addr, &len, hash);
485
486	eap_sim_msg_add(msg, EAP_SIM_AT_CHECKCODE, 0, hash,
487			data->eap_method == EAP_TYPE_AKA_PRIME ?
488			EAP_AKA_PRIME_CHECKCODE_LEN : EAP_AKA_CHECKCODE_LEN);
489}
490
491
492static int eap_aka_verify_checkcode(struct eap_aka_data *data,
493				    const u8 *checkcode, size_t checkcode_len)
494{
495	const u8 *addr;
496	size_t len;
497	u8 hash[SHA256_MAC_LEN];
498	size_t hash_len;
499
500	if (checkcode == NULL)
501		return -1;
502
503	if (data->id_msgs == NULL) {
504		if (checkcode_len != 0) {
505			wpa_printf(MSG_DEBUG, "EAP-AKA: Checkcode from server "
506				   "indicates that AKA/Identity messages were "
507				   "used, but they were not");
508			return -1;
509		}
510		return 0;
511	}
512
513	hash_len = data->eap_method == EAP_TYPE_AKA_PRIME ?
514		EAP_AKA_PRIME_CHECKCODE_LEN : EAP_AKA_CHECKCODE_LEN;
515
516	if (checkcode_len != hash_len) {
517		wpa_printf(MSG_DEBUG, "EAP-AKA: Checkcode from server "
518			   "indicates that AKA/Identity message were not "
519			   "used, but they were");
520		return -1;
521	}
522
523	/* Checkcode is SHA1/SHA256 hash over all EAP-AKA/Identity packets. */
524	addr = wpabuf_head(data->id_msgs);
525	len = wpabuf_len(data->id_msgs);
526#ifdef EAP_AKA_PRIME
527	if (data->eap_method == EAP_TYPE_AKA_PRIME)
528		sha256_vector(1, &addr, &len, hash);
529	else
530#endif /* EAP_AKA_PRIME */
531		sha1_vector(1, &addr, &len, hash);
532
533	if (os_memcmp_const(hash, checkcode, hash_len) != 0) {
534		wpa_printf(MSG_DEBUG, "EAP-AKA: Mismatch in AT_CHECKCODE");
535		return -1;
536	}
537
538	return 0;
539}
540
541
542static struct wpabuf * eap_aka_client_error(struct eap_aka_data *data, u8 id,
543					    int err)
544{
545	struct eap_sim_msg *msg;
546
547	eap_aka_state(data, FAILURE);
548	data->num_id_req = 0;
549	data->num_notification = 0;
550
551	wpa_printf(MSG_DEBUG, "EAP-AKA: Send Client-Error (error code %d)",
552		   err);
553	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
554			       EAP_AKA_SUBTYPE_CLIENT_ERROR);
555	eap_sim_msg_add(msg, EAP_SIM_AT_CLIENT_ERROR_CODE, err, NULL, 0);
556	return eap_sim_msg_finish(msg, data->eap_method, NULL, NULL, 0);
557}
558
559
560static struct wpabuf * eap_aka_authentication_reject(struct eap_aka_data *data,
561						     u8 id)
562{
563	struct eap_sim_msg *msg;
564
565	eap_aka_state(data, FAILURE);
566	data->num_id_req = 0;
567	data->num_notification = 0;
568
569	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Authentication-Reject "
570		   "(id=%d)", id);
571	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
572			       EAP_AKA_SUBTYPE_AUTHENTICATION_REJECT);
573	return eap_sim_msg_finish(msg, data->eap_method, NULL, NULL, 0);
574}
575
576
577static struct wpabuf * eap_aka_synchronization_failure(
578	struct eap_aka_data *data, u8 id)
579{
580	struct eap_sim_msg *msg;
581
582	data->num_id_req = 0;
583	data->num_notification = 0;
584
585	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Synchronization-Failure "
586		   "(id=%d)", id);
587	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
588			       EAP_AKA_SUBTYPE_SYNCHRONIZATION_FAILURE);
589	wpa_printf(MSG_DEBUG, "   AT_AUTS");
590	eap_sim_msg_add_full(msg, EAP_SIM_AT_AUTS, data->auts,
591			     EAP_AKA_AUTS_LEN);
592	return eap_sim_msg_finish(msg, data->eap_method, NULL, NULL, 0);
593}
594
595
596static struct wpabuf * eap_aka_response_identity(struct eap_sm *sm,
597						 struct eap_aka_data *data,
598						 u8 id,
599						 enum eap_sim_id_req id_req)
600{
601	const u8 *identity = NULL;
602	size_t identity_len = 0;
603	struct eap_sim_msg *msg;
604
605	data->reauth = 0;
606	if (id_req == ANY_ID && data->reauth_id) {
607		identity = data->reauth_id;
608		identity_len = data->reauth_id_len;
609		data->reauth = 1;
610	} else if ((id_req == ANY_ID || id_req == FULLAUTH_ID) &&
611		   data->pseudonym) {
612		identity = data->pseudonym;
613		identity_len = data->pseudonym_len;
614		eap_aka_clear_identities(sm, data, CLEAR_REAUTH_ID);
615	} else if (id_req != NO_ID_REQ) {
616		identity = eap_get_config_identity(sm, &identity_len);
617		if (identity) {
618			eap_aka_clear_identities(sm, data, CLEAR_PSEUDONYM |
619						 CLEAR_REAUTH_ID);
620		}
621	}
622	if (id_req != NO_ID_REQ)
623		eap_aka_clear_identities(sm, data, CLEAR_EAP_ID);
624
625	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Identity (id=%d)", id);
626	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
627			       EAP_AKA_SUBTYPE_IDENTITY);
628
629	if (identity) {
630		wpa_hexdump_ascii(MSG_DEBUG, "   AT_IDENTITY",
631				  identity, identity_len);
632		eap_sim_msg_add(msg, EAP_SIM_AT_IDENTITY, identity_len,
633				identity, identity_len);
634	}
635
636	return eap_sim_msg_finish(msg, data->eap_method, NULL, NULL, 0);
637}
638
639
640static struct wpabuf * eap_aka_response_challenge(struct eap_aka_data *data,
641						  u8 id)
642{
643	struct eap_sim_msg *msg;
644
645	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Challenge (id=%d)", id);
646	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
647			       EAP_AKA_SUBTYPE_CHALLENGE);
648	wpa_printf(MSG_DEBUG, "   AT_RES");
649	eap_sim_msg_add(msg, EAP_SIM_AT_RES, data->res_len * 8,
650			data->res, data->res_len);
651	eap_aka_add_checkcode(data, msg);
652	if (data->use_result_ind) {
653		wpa_printf(MSG_DEBUG, "   AT_RESULT_IND");
654		eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
655	}
656	wpa_printf(MSG_DEBUG, "   AT_MAC");
657	eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
658	return eap_sim_msg_finish(msg, data->eap_method, data->k_aut, (u8 *) "",
659				  0);
660}
661
662
663static struct wpabuf * eap_aka_response_reauth(struct eap_aka_data *data,
664					       u8 id, int counter_too_small,
665					       const u8 *nonce_s)
666{
667	struct eap_sim_msg *msg;
668	unsigned int counter;
669
670	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Reauthentication (id=%d)",
671		   id);
672	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
673			       EAP_AKA_SUBTYPE_REAUTHENTICATION);
674	wpa_printf(MSG_DEBUG, "   AT_IV");
675	wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
676	eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA);
677
678	if (counter_too_small) {
679		wpa_printf(MSG_DEBUG, "   *AT_COUNTER_TOO_SMALL");
680		eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER_TOO_SMALL, 0, NULL, 0);
681		counter = data->counter_too_small;
682	} else
683		counter = data->counter;
684
685	wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", counter);
686	eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0);
687
688	if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) {
689		wpa_printf(MSG_WARNING, "EAP-AKA: Failed to encrypt "
690			   "AT_ENCR_DATA");
691		eap_sim_msg_free(msg);
692		return NULL;
693	}
694	eap_aka_add_checkcode(data, msg);
695	if (data->use_result_ind) {
696		wpa_printf(MSG_DEBUG, "   AT_RESULT_IND");
697		eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
698	}
699	wpa_printf(MSG_DEBUG, "   AT_MAC");
700	eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
701	return eap_sim_msg_finish(msg, data->eap_method, data->k_aut, nonce_s,
702				  EAP_SIM_NONCE_S_LEN);
703}
704
705
706static struct wpabuf * eap_aka_response_notification(struct eap_aka_data *data,
707						     u8 id, u16 notification)
708{
709	struct eap_sim_msg *msg;
710	u8 *k_aut = (notification & 0x4000) == 0 ? data->k_aut : NULL;
711
712	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Notification (id=%d)", id);
713	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
714			       EAP_AKA_SUBTYPE_NOTIFICATION);
715	if (k_aut && data->reauth) {
716		wpa_printf(MSG_DEBUG, "   AT_IV");
717		wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
718		eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
719					   EAP_SIM_AT_ENCR_DATA);
720		wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", data->counter);
721		eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
722				NULL, 0);
723		if (eap_sim_msg_add_encr_end(msg, data->k_encr,
724					     EAP_SIM_AT_PADDING)) {
725			wpa_printf(MSG_WARNING, "EAP-AKA: Failed to encrypt "
726				   "AT_ENCR_DATA");
727			eap_sim_msg_free(msg);
728			return NULL;
729		}
730	}
731	if (k_aut) {
732		wpa_printf(MSG_DEBUG, "   AT_MAC");
733		eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
734	}
735	return eap_sim_msg_finish(msg, data->eap_method, k_aut, (u8 *) "", 0);
736}
737
738
739static struct wpabuf * eap_aka_process_identity(struct eap_sm *sm,
740						struct eap_aka_data *data,
741						u8 id,
742						const struct wpabuf *reqData,
743						struct eap_sim_attrs *attr)
744{
745	int id_error;
746	struct wpabuf *buf;
747
748	wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Identity");
749
750	id_error = 0;
751	switch (attr->id_req) {
752	case NO_ID_REQ:
753		break;
754	case ANY_ID:
755		if (data->num_id_req > 0)
756			id_error++;
757		data->num_id_req++;
758		break;
759	case FULLAUTH_ID:
760		if (data->num_id_req > 1)
761			id_error++;
762		data->num_id_req++;
763		break;
764	case PERMANENT_ID:
765		if (data->num_id_req > 2)
766			id_error++;
767		data->num_id_req++;
768		break;
769	}
770	if (id_error) {
771		wpa_printf(MSG_INFO, "EAP-AKA: Too many ID requests "
772			   "used within one authentication");
773		return eap_aka_client_error(data, id,
774					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
775	}
776
777	buf = eap_aka_response_identity(sm, data, id, attr->id_req);
778
779	if (data->prev_id != id) {
780		eap_aka_add_id_msg(data, reqData);
781		eap_aka_add_id_msg(data, buf);
782		data->prev_id = id;
783	}
784
785	return buf;
786}
787
788
789static int eap_aka_verify_mac(struct eap_aka_data *data,
790			      const struct wpabuf *req,
791			      const u8 *mac, const u8 *extra,
792			      size_t extra_len)
793{
794	if (data->eap_method == EAP_TYPE_AKA_PRIME)
795		return eap_sim_verify_mac_sha256(data->k_aut, req, mac, extra,
796						 extra_len);
797	return eap_sim_verify_mac(data->k_aut, req, mac, extra, extra_len);
798}
799
800
801#ifdef EAP_AKA_PRIME
802static struct wpabuf * eap_aka_prime_kdf_select(struct eap_aka_data *data,
803						u8 id, u16 kdf)
804{
805	struct eap_sim_msg *msg;
806
807	data->kdf_negotiation = 1;
808	data->kdf = kdf;
809	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Challenge (id=%d) (KDF "
810		   "select)", id);
811	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
812			       EAP_AKA_SUBTYPE_CHALLENGE);
813	wpa_printf(MSG_DEBUG, "   AT_KDF");
814	eap_sim_msg_add(msg, EAP_SIM_AT_KDF, kdf, NULL, 0);
815	return eap_sim_msg_finish(msg, data->eap_method, NULL, NULL, 0);
816}
817
818
819static struct wpabuf * eap_aka_prime_kdf_neg(struct eap_aka_data *data,
820					     u8 id, struct eap_sim_attrs *attr)
821{
822	size_t i;
823
824	for (i = 0; i < attr->kdf_count; i++) {
825		if (attr->kdf[i] == EAP_AKA_PRIME_KDF)
826			return eap_aka_prime_kdf_select(data, id,
827							EAP_AKA_PRIME_KDF);
828	}
829
830	/* No matching KDF found - fail authentication as if AUTN had been
831	 * incorrect */
832	return eap_aka_authentication_reject(data, id);
833}
834
835
836static int eap_aka_prime_kdf_valid(struct eap_aka_data *data,
837				   struct eap_sim_attrs *attr)
838{
839	size_t i, j;
840
841	if (attr->kdf_count == 0)
842		return 0;
843
844	/* The only allowed (and required) duplication of a KDF is the addition
845	 * of the selected KDF into the beginning of the list. */
846
847	if (data->kdf_negotiation) {
848		if (attr->kdf[0] != data->kdf) {
849			wpa_printf(MSG_WARNING, "EAP-AKA': The server did not "
850				   "accept the selected KDF");
851			return 0;
852		}
853
854		for (i = 1; i < attr->kdf_count; i++) {
855			if (attr->kdf[i] == data->kdf)
856				break;
857		}
858		if (i == attr->kdf_count &&
859		    attr->kdf_count < EAP_AKA_PRIME_KDF_MAX) {
860			wpa_printf(MSG_WARNING, "EAP-AKA': The server did not "
861				   "duplicate the selected KDF");
862			return 0;
863		}
864
865		/* TODO: should check that the list is identical to the one
866		 * used in the previous Challenge message apart from the added
867		 * entry in the beginning. */
868	}
869
870	for (i = data->kdf ? 1 : 0; i < attr->kdf_count; i++) {
871		for (j = i + 1; j < attr->kdf_count; j++) {
872			if (attr->kdf[i] == attr->kdf[j]) {
873				wpa_printf(MSG_WARNING, "EAP-AKA': The server "
874					   "included a duplicated KDF");
875				return 0;
876			}
877		}
878	}
879
880	return 1;
881}
882#endif /* EAP_AKA_PRIME */
883
884
885static struct wpabuf * eap_aka_process_challenge(struct eap_sm *sm,
886						 struct eap_aka_data *data,
887						 u8 id,
888						 const struct wpabuf *reqData,
889						 struct eap_sim_attrs *attr)
890{
891	const u8 *identity;
892	size_t identity_len;
893	int res;
894	struct eap_sim_attrs eattr;
895
896	wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Challenge");
897
898	if (attr->checkcode &&
899	    eap_aka_verify_checkcode(data, attr->checkcode,
900				     attr->checkcode_len)) {
901		wpa_printf(MSG_WARNING, "EAP-AKA: Invalid AT_CHECKCODE in the "
902			   "message");
903		return eap_aka_client_error(data, id,
904					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
905	}
906
907#ifdef EAP_AKA_PRIME
908	if (data->eap_method == EAP_TYPE_AKA_PRIME) {
909		if (!attr->kdf_input || attr->kdf_input_len == 0) {
910			wpa_printf(MSG_WARNING, "EAP-AKA': Challenge message "
911				   "did not include non-empty AT_KDF_INPUT");
912			/* Fail authentication as if AUTN had been incorrect */
913			return eap_aka_authentication_reject(data, id);
914		}
915		os_free(data->network_name);
916		data->network_name = os_malloc(attr->kdf_input_len);
917		if (data->network_name == NULL) {
918			wpa_printf(MSG_WARNING, "EAP-AKA': No memory for "
919				   "storing Network Name");
920			return eap_aka_authentication_reject(data, id);
921		}
922		os_memcpy(data->network_name, attr->kdf_input,
923			  attr->kdf_input_len);
924		data->network_name_len = attr->kdf_input_len;
925		wpa_hexdump_ascii(MSG_DEBUG, "EAP-AKA': Network Name "
926				  "(AT_KDF_INPUT)",
927				  data->network_name, data->network_name_len);
928		/* TODO: check Network Name per 3GPP.33.402 */
929
930		if (!eap_aka_prime_kdf_valid(data, attr))
931			return eap_aka_authentication_reject(data, id);
932
933		if (attr->kdf[0] != EAP_AKA_PRIME_KDF)
934			return eap_aka_prime_kdf_neg(data, id, attr);
935
936		data->kdf = EAP_AKA_PRIME_KDF;
937		wpa_printf(MSG_DEBUG, "EAP-AKA': KDF %d selected", data->kdf);
938	}
939
940	if (data->eap_method == EAP_TYPE_AKA && attr->bidding) {
941		u16 flags = WPA_GET_BE16(attr->bidding);
942		if ((flags & EAP_AKA_BIDDING_FLAG_D) &&
943		    eap_allowed_method(sm, EAP_VENDOR_IETF,
944				       EAP_TYPE_AKA_PRIME)) {
945			wpa_printf(MSG_WARNING, "EAP-AKA: Bidding down from "
946				   "AKA' to AKA detected");
947			/* Fail authentication as if AUTN had been incorrect */
948			return eap_aka_authentication_reject(data, id);
949		}
950	}
951#endif /* EAP_AKA_PRIME */
952
953	data->reauth = 0;
954	if (!attr->mac || !attr->rand || !attr->autn) {
955		wpa_printf(MSG_WARNING, "EAP-AKA: Challenge message "
956			   "did not include%s%s%s",
957			   !attr->mac ? " AT_MAC" : "",
958			   !attr->rand ? " AT_RAND" : "",
959			   !attr->autn ? " AT_AUTN" : "");
960		return eap_aka_client_error(data, id,
961					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
962	}
963	os_memcpy(data->rand, attr->rand, EAP_AKA_RAND_LEN);
964	os_memcpy(data->autn, attr->autn, EAP_AKA_AUTN_LEN);
965
966	res = eap_aka_umts_auth(sm, data);
967	if (res == -1) {
968		wpa_printf(MSG_WARNING, "EAP-AKA: UMTS authentication "
969			   "failed (AUTN)");
970		return eap_aka_authentication_reject(data, id);
971	} else if (res == -2) {
972		wpa_printf(MSG_WARNING, "EAP-AKA: UMTS authentication "
973			   "failed (AUTN seq# -> AUTS)");
974		return eap_aka_synchronization_failure(data, id);
975	} else if (res > 0) {
976		wpa_printf(MSG_DEBUG, "EAP-AKA: Wait for external USIM processing");
977		return NULL;
978	} else if (res) {
979		wpa_printf(MSG_WARNING, "EAP-AKA: UMTS authentication failed");
980		return eap_aka_client_error(data, id,
981					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
982	}
983#ifdef EAP_AKA_PRIME
984	if (data->eap_method == EAP_TYPE_AKA_PRIME) {
985		/* Note: AUTN = (SQN ^ AK) || AMF || MAC which gives us the
986		 * needed 6-octet SQN ^ AK for CK',IK' derivation */
987		u16 amf = WPA_GET_BE16(data->autn + 6);
988		if (!(amf & 0x8000)) {
989			wpa_printf(MSG_WARNING, "EAP-AKA': AMF separation bit "
990				   "not set (AMF=0x%4x)", amf);
991			return eap_aka_authentication_reject(data, id);
992		}
993		eap_aka_prime_derive_ck_ik_prime(data->ck, data->ik,
994						 data->autn,
995						 data->network_name,
996						 data->network_name_len);
997	}
998#endif /* EAP_AKA_PRIME */
999	if (data->last_eap_identity) {
1000		identity = data->last_eap_identity;
1001		identity_len = data->last_eap_identity_len;
1002	} else if (data->pseudonym) {
1003		identity = data->pseudonym;
1004		identity_len = data->pseudonym_len;
1005	} else
1006		identity = eap_get_config_identity(sm, &identity_len);
1007	wpa_hexdump_ascii(MSG_DEBUG, "EAP-AKA: Selected identity for MK "
1008			  "derivation", identity, identity_len);
1009	if (data->eap_method == EAP_TYPE_AKA_PRIME) {
1010		eap_aka_prime_derive_keys(identity, identity_len, data->ik,
1011					  data->ck, data->k_encr, data->k_aut,
1012					  data->k_re, data->msk, data->emsk);
1013	} else {
1014		eap_aka_derive_mk(identity, identity_len, data->ik, data->ck,
1015				  data->mk);
1016		eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut,
1017				    data->msk, data->emsk);
1018	}
1019	if (eap_aka_verify_mac(data, reqData, attr->mac, (u8 *) "", 0)) {
1020		wpa_printf(MSG_WARNING, "EAP-AKA: Challenge message "
1021			   "used invalid AT_MAC");
1022		return eap_aka_client_error(data, id,
1023					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1024	}
1025
1026	/* Old reauthentication identity must not be used anymore. In
1027	 * other words, if no new identities are received, full
1028	 * authentication will be used on next reauthentication (using
1029	 * pseudonym identity or permanent identity). */
1030	eap_aka_clear_identities(sm, data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
1031
1032	if (attr->encr_data) {
1033		u8 *decrypted;
1034		decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
1035					       attr->encr_data_len, attr->iv,
1036					       &eattr, 0);
1037		if (decrypted == NULL) {
1038			return eap_aka_client_error(
1039				data, id, EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1040		}
1041		eap_aka_learn_ids(sm, data, &eattr);
1042		os_free(decrypted);
1043	}
1044
1045	if (data->result_ind && attr->result_ind)
1046		data->use_result_ind = 1;
1047
1048	if (data->state != FAILURE) {
1049		eap_aka_state(data, data->use_result_ind ?
1050			      RESULT_SUCCESS : SUCCESS);
1051	}
1052
1053	data->num_id_req = 0;
1054	data->num_notification = 0;
1055	/* RFC 4187 specifies that counter is initialized to one after
1056	 * fullauth, but initializing it to zero makes it easier to implement
1057	 * reauth verification. */
1058	data->counter = 0;
1059	return eap_aka_response_challenge(data, id);
1060}
1061
1062
1063static int eap_aka_process_notification_reauth(struct eap_aka_data *data,
1064					       struct eap_sim_attrs *attr)
1065{
1066	struct eap_sim_attrs eattr;
1067	u8 *decrypted;
1068
1069	if (attr->encr_data == NULL || attr->iv == NULL) {
1070		wpa_printf(MSG_WARNING, "EAP-AKA: Notification message after "
1071			   "reauth did not include encrypted data");
1072		return -1;
1073	}
1074
1075	decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
1076				       attr->encr_data_len, attr->iv, &eattr,
1077				       0);
1078	if (decrypted == NULL) {
1079		wpa_printf(MSG_WARNING, "EAP-AKA: Failed to parse encrypted "
1080			   "data from notification message");
1081		return -1;
1082	}
1083
1084	if (eattr.counter < 0 || (size_t) eattr.counter != data->counter) {
1085		wpa_printf(MSG_WARNING, "EAP-AKA: Counter in notification "
1086			   "message does not match with counter in reauth "
1087			   "message");
1088		os_free(decrypted);
1089		return -1;
1090	}
1091
1092	os_free(decrypted);
1093	return 0;
1094}
1095
1096
1097static int eap_aka_process_notification_auth(struct eap_aka_data *data,
1098					     const struct wpabuf *reqData,
1099					     struct eap_sim_attrs *attr)
1100{
1101	if (attr->mac == NULL) {
1102		wpa_printf(MSG_INFO, "EAP-AKA: no AT_MAC in after_auth "
1103			   "Notification message");
1104		return -1;
1105	}
1106
1107	if (eap_aka_verify_mac(data, reqData, attr->mac, (u8 *) "", 0)) {
1108		wpa_printf(MSG_WARNING, "EAP-AKA: Notification message "
1109			   "used invalid AT_MAC");
1110		return -1;
1111	}
1112
1113	if (data->reauth &&
1114	    eap_aka_process_notification_reauth(data, attr)) {
1115		wpa_printf(MSG_WARNING, "EAP-AKA: Invalid notification "
1116			   "message after reauth");
1117		return -1;
1118	}
1119
1120	return 0;
1121}
1122
1123
1124static struct wpabuf * eap_aka_process_notification(
1125	struct eap_sm *sm, struct eap_aka_data *data, u8 id,
1126	const struct wpabuf *reqData, struct eap_sim_attrs *attr)
1127{
1128	wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Notification");
1129	if (data->num_notification > 0) {
1130		wpa_printf(MSG_INFO, "EAP-AKA: too many notification "
1131			   "rounds (only one allowed)");
1132		return eap_aka_client_error(data, id,
1133					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1134	}
1135	data->num_notification++;
1136	if (attr->notification == -1) {
1137		wpa_printf(MSG_INFO, "EAP-AKA: no AT_NOTIFICATION in "
1138			   "Notification message");
1139		return eap_aka_client_error(data, id,
1140					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1141	}
1142
1143	if ((attr->notification & 0x4000) == 0 &&
1144	    eap_aka_process_notification_auth(data, reqData, attr)) {
1145		return eap_aka_client_error(data, id,
1146					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1147	}
1148
1149	eap_sim_report_notification(sm->msg_ctx, attr->notification, 1);
1150	if (attr->notification >= 0 && attr->notification < 32768) {
1151		eap_aka_state(data, FAILURE);
1152	} else if (attr->notification == EAP_SIM_SUCCESS &&
1153		   data->state == RESULT_SUCCESS)
1154		eap_aka_state(data, SUCCESS);
1155	return eap_aka_response_notification(data, id, attr->notification);
1156}
1157
1158
1159static struct wpabuf * eap_aka_process_reauthentication(
1160	struct eap_sm *sm, struct eap_aka_data *data, u8 id,
1161	const struct wpabuf *reqData, struct eap_sim_attrs *attr)
1162{
1163	struct eap_sim_attrs eattr;
1164	u8 *decrypted;
1165
1166	wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Reauthentication");
1167
1168	if (attr->checkcode &&
1169	    eap_aka_verify_checkcode(data, attr->checkcode,
1170				     attr->checkcode_len)) {
1171		wpa_printf(MSG_WARNING, "EAP-AKA: Invalid AT_CHECKCODE in the "
1172			   "message");
1173		return eap_aka_client_error(data, id,
1174					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1175	}
1176
1177	if (data->reauth_id == NULL) {
1178		wpa_printf(MSG_WARNING, "EAP-AKA: Server is trying "
1179			   "reauthentication, but no reauth_id available");
1180		return eap_aka_client_error(data, id,
1181					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1182	}
1183
1184	data->reauth = 1;
1185	if (eap_aka_verify_mac(data, reqData, attr->mac, (u8 *) "", 0)) {
1186		wpa_printf(MSG_WARNING, "EAP-AKA: Reauthentication "
1187			   "did not have valid AT_MAC");
1188		return eap_aka_client_error(data, id,
1189					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1190	}
1191
1192	if (attr->encr_data == NULL || attr->iv == NULL) {
1193		wpa_printf(MSG_WARNING, "EAP-AKA: Reauthentication "
1194			   "message did not include encrypted data");
1195		return eap_aka_client_error(data, id,
1196					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1197	}
1198
1199	decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
1200				       attr->encr_data_len, attr->iv, &eattr,
1201				       0);
1202	if (decrypted == NULL) {
1203		wpa_printf(MSG_WARNING, "EAP-AKA: Failed to parse encrypted "
1204			   "data from reauthentication message");
1205		return eap_aka_client_error(data, id,
1206					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1207	}
1208
1209	if (eattr.nonce_s == NULL || eattr.counter < 0) {
1210		wpa_printf(MSG_INFO, "EAP-AKA: (encr) No%s%s in reauth packet",
1211			   !eattr.nonce_s ? " AT_NONCE_S" : "",
1212			   eattr.counter < 0 ? " AT_COUNTER" : "");
1213		os_free(decrypted);
1214		return eap_aka_client_error(data, id,
1215					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1216	}
1217
1218	if (eattr.counter < 0 || (size_t) eattr.counter <= data->counter) {
1219		struct wpabuf *res;
1220		wpa_printf(MSG_INFO, "EAP-AKA: (encr) Invalid counter "
1221			   "(%d <= %d)", eattr.counter, data->counter);
1222		data->counter_too_small = eattr.counter;
1223
1224		/* Reply using Re-auth w/ AT_COUNTER_TOO_SMALL. The current
1225		 * reauth_id must not be used to start a new reauthentication.
1226		 * However, since it was used in the last EAP-Response-Identity
1227		 * packet, it has to saved for the following fullauth to be
1228		 * used in MK derivation. */
1229		os_free(data->last_eap_identity);
1230		data->last_eap_identity = data->reauth_id;
1231		data->last_eap_identity_len = data->reauth_id_len;
1232		data->reauth_id = NULL;
1233		data->reauth_id_len = 0;
1234
1235		res = eap_aka_response_reauth(data, id, 1, eattr.nonce_s);
1236		os_free(decrypted);
1237
1238		return res;
1239	}
1240	data->counter = eattr.counter;
1241
1242	os_memcpy(data->nonce_s, eattr.nonce_s, EAP_SIM_NONCE_S_LEN);
1243	wpa_hexdump(MSG_DEBUG, "EAP-AKA: (encr) AT_NONCE_S",
1244		    data->nonce_s, EAP_SIM_NONCE_S_LEN);
1245
1246	if (data->eap_method == EAP_TYPE_AKA_PRIME) {
1247		eap_aka_prime_derive_keys_reauth(data->k_re, data->counter,
1248						 data->reauth_id,
1249						 data->reauth_id_len,
1250						 data->nonce_s,
1251						 data->msk, data->emsk);
1252	} else {
1253		eap_sim_derive_keys_reauth(data->counter, data->reauth_id,
1254					   data->reauth_id_len,
1255					   data->nonce_s, data->mk,
1256					   data->msk, data->emsk);
1257	}
1258	eap_aka_clear_identities(sm, data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
1259	eap_aka_learn_ids(sm, data, &eattr);
1260
1261	if (data->result_ind && attr->result_ind)
1262		data->use_result_ind = 1;
1263
1264	if (data->state != FAILURE) {
1265		eap_aka_state(data, data->use_result_ind ?
1266			      RESULT_SUCCESS : SUCCESS);
1267	}
1268
1269	data->num_id_req = 0;
1270	data->num_notification = 0;
1271	if (data->counter > EAP_AKA_MAX_FAST_REAUTHS) {
1272		wpa_printf(MSG_DEBUG, "EAP-AKA: Maximum number of "
1273			   "fast reauths performed - force fullauth");
1274		eap_aka_clear_identities(sm, data,
1275					 CLEAR_REAUTH_ID | CLEAR_EAP_ID);
1276	}
1277	os_free(decrypted);
1278	return eap_aka_response_reauth(data, id, 0, data->nonce_s);
1279}
1280
1281
1282static struct wpabuf * eap_aka_process(struct eap_sm *sm, void *priv,
1283				       struct eap_method_ret *ret,
1284				       const struct wpabuf *reqData)
1285{
1286	struct eap_aka_data *data = priv;
1287	const struct eap_hdr *req;
1288	u8 subtype, id;
1289	struct wpabuf *res;
1290	const u8 *pos;
1291	struct eap_sim_attrs attr;
1292	size_t len;
1293
1294	wpa_hexdump_buf(MSG_DEBUG, "EAP-AKA: EAP data", reqData);
1295	if (eap_get_config_identity(sm, &len) == NULL) {
1296		wpa_printf(MSG_INFO, "EAP-AKA: Identity not configured");
1297		eap_sm_request_identity(sm);
1298		ret->ignore = TRUE;
1299		return NULL;
1300	}
1301
1302	pos = eap_hdr_validate(EAP_VENDOR_IETF, data->eap_method, reqData,
1303			       &len);
1304	if (pos == NULL || len < 3) {
1305		ret->ignore = TRUE;
1306		return NULL;
1307	}
1308	req = wpabuf_head(reqData);
1309	id = req->identifier;
1310	len = be_to_host16(req->length);
1311
1312	ret->ignore = FALSE;
1313	ret->methodState = METHOD_MAY_CONT;
1314	ret->decision = DECISION_FAIL;
1315	ret->allowNotifications = TRUE;
1316
1317	subtype = *pos++;
1318	wpa_printf(MSG_DEBUG, "EAP-AKA: Subtype=%d", subtype);
1319	pos += 2; /* Reserved */
1320
1321	if (eap_sim_parse_attr(pos, wpabuf_head_u8(reqData) + len, &attr,
1322			       data->eap_method == EAP_TYPE_AKA_PRIME ? 2 : 1,
1323			       0)) {
1324		res = eap_aka_client_error(data, id,
1325					   EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1326		goto done;
1327	}
1328
1329	switch (subtype) {
1330	case EAP_AKA_SUBTYPE_IDENTITY:
1331		res = eap_aka_process_identity(sm, data, id, reqData, &attr);
1332		break;
1333	case EAP_AKA_SUBTYPE_CHALLENGE:
1334		res = eap_aka_process_challenge(sm, data, id, reqData, &attr);
1335		break;
1336	case EAP_AKA_SUBTYPE_NOTIFICATION:
1337		res = eap_aka_process_notification(sm, data, id, reqData,
1338						   &attr);
1339		break;
1340	case EAP_AKA_SUBTYPE_REAUTHENTICATION:
1341		res = eap_aka_process_reauthentication(sm, data, id, reqData,
1342						       &attr);
1343		break;
1344	case EAP_AKA_SUBTYPE_CLIENT_ERROR:
1345		wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Client-Error");
1346		res = eap_aka_client_error(data, id,
1347					   EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1348		break;
1349	default:
1350		wpa_printf(MSG_DEBUG, "EAP-AKA: Unknown subtype=%d", subtype);
1351		res = eap_aka_client_error(data, id,
1352					   EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1353		break;
1354	}
1355
1356done:
1357	if (data->state == FAILURE) {
1358		ret->decision = DECISION_FAIL;
1359		ret->methodState = METHOD_DONE;
1360	} else if (data->state == SUCCESS) {
1361		ret->decision = data->use_result_ind ?
1362			DECISION_UNCOND_SUCC : DECISION_COND_SUCC;
1363		/*
1364		 * It is possible for the server to reply with AKA
1365		 * Notification, so we must allow the method to continue and
1366		 * not only accept EAP-Success at this point.
1367		 */
1368		ret->methodState = data->use_result_ind ?
1369			METHOD_DONE : METHOD_MAY_CONT;
1370	} else if (data->state == RESULT_SUCCESS)
1371		ret->methodState = METHOD_CONT;
1372
1373	if (ret->methodState == METHOD_DONE) {
1374		ret->allowNotifications = FALSE;
1375	}
1376
1377	return res;
1378}
1379
1380
1381static Boolean eap_aka_has_reauth_data(struct eap_sm *sm, void *priv)
1382{
1383	struct eap_aka_data *data = priv;
1384	return data->pseudonym || data->reauth_id;
1385}
1386
1387
1388static void eap_aka_deinit_for_reauth(struct eap_sm *sm, void *priv)
1389{
1390	struct eap_aka_data *data = priv;
1391	eap_aka_clear_identities(sm, data, CLEAR_EAP_ID);
1392	data->prev_id = -1;
1393	wpabuf_free(data->id_msgs);
1394	data->id_msgs = NULL;
1395	data->use_result_ind = 0;
1396	data->kdf_negotiation = 0;
1397	eap_aka_clear_keys(data, 1);
1398}
1399
1400
1401static void * eap_aka_init_for_reauth(struct eap_sm *sm, void *priv)
1402{
1403	struct eap_aka_data *data = priv;
1404	data->num_id_req = 0;
1405	data->num_notification = 0;
1406	eap_aka_state(data, CONTINUE);
1407	return priv;
1408}
1409
1410
1411static const u8 * eap_aka_get_identity(struct eap_sm *sm, void *priv,
1412				       size_t *len)
1413{
1414	struct eap_aka_data *data = priv;
1415
1416	if (data->reauth_id) {
1417		*len = data->reauth_id_len;
1418		return data->reauth_id;
1419	}
1420
1421	if (data->pseudonym) {
1422		*len = data->pseudonym_len;
1423		return data->pseudonym;
1424	}
1425
1426	return NULL;
1427}
1428
1429
1430static Boolean eap_aka_isKeyAvailable(struct eap_sm *sm, void *priv)
1431{
1432	struct eap_aka_data *data = priv;
1433	return data->state == SUCCESS;
1434}
1435
1436
1437static u8 * eap_aka_getKey(struct eap_sm *sm, void *priv, size_t *len)
1438{
1439	struct eap_aka_data *data = priv;
1440	u8 *key;
1441
1442	if (data->state != SUCCESS)
1443		return NULL;
1444
1445	key = os_malloc(EAP_SIM_KEYING_DATA_LEN);
1446	if (key == NULL)
1447		return NULL;
1448
1449	*len = EAP_SIM_KEYING_DATA_LEN;
1450	os_memcpy(key, data->msk, EAP_SIM_KEYING_DATA_LEN);
1451
1452	return key;
1453}
1454
1455
1456static u8 * eap_aka_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
1457{
1458	struct eap_aka_data *data = priv;
1459	u8 *id;
1460
1461	if (data->state != SUCCESS)
1462		return NULL;
1463
1464	*len = 1 + EAP_AKA_RAND_LEN + EAP_AKA_AUTN_LEN;
1465	id = os_malloc(*len);
1466	if (id == NULL)
1467		return NULL;
1468
1469	id[0] = data->eap_method;
1470	os_memcpy(id + 1, data->rand, EAP_AKA_RAND_LEN);
1471	os_memcpy(id + 1 + EAP_AKA_RAND_LEN, data->autn, EAP_AKA_AUTN_LEN);
1472	wpa_hexdump(MSG_DEBUG, "EAP-AKA: Derived Session-Id", id, *len);
1473
1474	return id;
1475}
1476
1477
1478static u8 * eap_aka_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
1479{
1480	struct eap_aka_data *data = priv;
1481	u8 *key;
1482
1483	if (data->state != SUCCESS)
1484		return NULL;
1485
1486	key = os_malloc(EAP_EMSK_LEN);
1487	if (key == NULL)
1488		return NULL;
1489
1490	*len = EAP_EMSK_LEN;
1491	os_memcpy(key, data->emsk, EAP_EMSK_LEN);
1492
1493	return key;
1494}
1495
1496
1497int eap_peer_aka_register(void)
1498{
1499	struct eap_method *eap;
1500
1501	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
1502				    EAP_VENDOR_IETF, EAP_TYPE_AKA, "AKA");
1503	if (eap == NULL)
1504		return -1;
1505
1506	eap->init = eap_aka_init;
1507	eap->deinit = eap_aka_deinit;
1508	eap->process = eap_aka_process;
1509	eap->isKeyAvailable = eap_aka_isKeyAvailable;
1510	eap->getKey = eap_aka_getKey;
1511	eap->getSessionId = eap_aka_get_session_id;
1512	eap->has_reauth_data = eap_aka_has_reauth_data;
1513	eap->deinit_for_reauth = eap_aka_deinit_for_reauth;
1514	eap->init_for_reauth = eap_aka_init_for_reauth;
1515	eap->get_identity = eap_aka_get_identity;
1516	eap->get_emsk = eap_aka_get_emsk;
1517
1518	return eap_peer_method_register(eap);
1519}
1520
1521
1522#ifdef EAP_AKA_PRIME
1523int eap_peer_aka_prime_register(void)
1524{
1525	struct eap_method *eap;
1526
1527	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
1528				    EAP_VENDOR_IETF, EAP_TYPE_AKA_PRIME,
1529				    "AKA'");
1530	if (eap == NULL)
1531		return -1;
1532
1533	eap->init = eap_aka_prime_init;
1534	eap->deinit = eap_aka_deinit;
1535	eap->process = eap_aka_process;
1536	eap->isKeyAvailable = eap_aka_isKeyAvailable;
1537	eap->getKey = eap_aka_getKey;
1538	eap->getSessionId = eap_aka_get_session_id;
1539	eap->has_reauth_data = eap_aka_has_reauth_data;
1540	eap->deinit_for_reauth = eap_aka_deinit_for_reauth;
1541	eap->init_for_reauth = eap_aka_init_for_reauth;
1542	eap->get_identity = eap_aka_get_identity;
1543	eap->get_emsk = eap_aka_get_emsk;
1544
1545	return eap_peer_method_register(eap);
1546}
1547#endif /* EAP_AKA_PRIME */
1548