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	u16 last_kdf_attrs[EAP_AKA_PRIME_KDF_MAX];
58	size_t last_kdf_count;
59	int error_code;
60};
61
62
63#ifndef CONFIG_NO_STDOUT_DEBUG
64static const char * eap_aka_state_txt(int state)
65{
66	switch (state) {
67	case CONTINUE:
68		return "CONTINUE";
69	case RESULT_SUCCESS:
70		return "RESULT_SUCCESS";
71	case SUCCESS:
72		return "SUCCESS";
73	case FAILURE:
74		return "FAILURE";
75	default:
76		return "?";
77	}
78}
79#endif /* CONFIG_NO_STDOUT_DEBUG */
80
81
82static void eap_aka_state(struct eap_aka_data *data, int state)
83{
84	wpa_printf(MSG_DEBUG, "EAP-AKA: %s -> %s",
85		   eap_aka_state_txt(data->state),
86		   eap_aka_state_txt(state));
87	data->state = state;
88}
89
90
91static void * eap_aka_init(struct eap_sm *sm)
92{
93	struct eap_aka_data *data;
94	const char *phase1 = eap_get_config_phase1(sm);
95	struct eap_peer_config *config = eap_get_config(sm);
96
97	data = os_zalloc(sizeof(*data));
98	if (data == NULL)
99		return NULL;
100
101	data->eap_method = EAP_TYPE_AKA;
102
103	/* Zero is a valid error code, so we need to initialize */
104	data->error_code = NO_EAP_METHOD_ERROR;
105
106	eap_aka_state(data, CONTINUE);
107	data->prev_id = -1;
108
109	data->result_ind = phase1 && os_strstr(phase1, "result_ind=1") != NULL;
110
111	data->use_pseudonym = !sm->init_phase2;
112	if (config && config->anonymous_identity && data->use_pseudonym) {
113		data->pseudonym = os_malloc(config->anonymous_identity_len);
114		if (data->pseudonym) {
115			os_memcpy(data->pseudonym, config->anonymous_identity,
116				  config->anonymous_identity_len);
117			data->pseudonym_len = config->anonymous_identity_len;
118		}
119	}
120
121	return data;
122}
123
124
125#ifdef EAP_AKA_PRIME
126static void * eap_aka_prime_init(struct eap_sm *sm)
127{
128	struct eap_aka_data *data = eap_aka_init(sm);
129	if (data == NULL)
130		return NULL;
131	data->eap_method = EAP_TYPE_AKA_PRIME;
132	return data;
133}
134#endif /* EAP_AKA_PRIME */
135
136
137static void eap_aka_clear_keys(struct eap_aka_data *data, int reauth)
138{
139	if (!reauth) {
140		os_memset(data->mk, 0, EAP_SIM_MK_LEN);
141		os_memset(data->k_aut, 0, EAP_AKA_PRIME_K_AUT_LEN);
142		os_memset(data->k_encr, 0, EAP_SIM_K_ENCR_LEN);
143		os_memset(data->k_re, 0, EAP_AKA_PRIME_K_RE_LEN);
144	}
145	os_memset(data->msk, 0, EAP_SIM_KEYING_DATA_LEN);
146	os_memset(data->emsk, 0, EAP_EMSK_LEN);
147	os_memset(data->autn, 0, EAP_AKA_AUTN_LEN);
148	os_memset(data->auts, 0, EAP_AKA_AUTS_LEN);
149}
150
151
152static void eap_aka_deinit(struct eap_sm *sm, void *priv)
153{
154	struct eap_aka_data *data = priv;
155	if (data) {
156		os_free(data->pseudonym);
157		os_free(data->reauth_id);
158		os_free(data->last_eap_identity);
159		wpabuf_free(data->id_msgs);
160		os_free(data->network_name);
161		eap_aka_clear_keys(data, 0);
162		os_free(data);
163	}
164}
165
166
167static int eap_aka_ext_sim_req(struct eap_sm *sm, struct eap_aka_data *data)
168{
169	char req[200], *pos, *end;
170
171	wpa_printf(MSG_DEBUG, "EAP-AKA: Use external USIM processing");
172	pos = req;
173	end = pos + sizeof(req);
174	pos += os_snprintf(pos, end - pos, "UMTS-AUTH");
175	pos += os_snprintf(pos, end - pos, ":");
176	pos += wpa_snprintf_hex(pos, end - pos, data->rand, EAP_AKA_RAND_LEN);
177	pos += os_snprintf(pos, end - pos, ":");
178	wpa_snprintf_hex(pos, end - pos, data->autn, EAP_AKA_AUTN_LEN);
179
180	eap_sm_request_sim(sm, req);
181	return 1;
182}
183
184
185static int eap_aka_ext_sim_result(struct eap_sm *sm, struct eap_aka_data *data,
186				  struct eap_peer_config *conf)
187{
188	char *resp, *pos;
189
190	wpa_printf(MSG_DEBUG,
191		   "EAP-AKA: Use result from external USIM processing");
192
193	resp = conf->external_sim_resp;
194	conf->external_sim_resp = NULL;
195
196	if (os_strncmp(resp, "UMTS-AUTS:", 10) == 0) {
197		pos = resp + 10;
198		if (hexstr2bin(pos, data->auts, EAP_AKA_AUTS_LEN) < 0)
199			goto invalid;
200		wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: AUTS", data->auts,
201				EAP_AKA_AUTS_LEN);
202		os_free(resp);
203		return -2;
204	}
205
206	if (os_strncmp(resp, "UMTS-AUTH:", 10) != 0) {
207		wpa_printf(MSG_DEBUG, "EAP-AKA: Unrecognized external USIM processing response");
208		os_free(resp);
209		return -1;
210	}
211
212	pos = resp + 10;
213	wpa_hexdump(MSG_DEBUG, "EAP-AKA: RAND", data->rand, EAP_AKA_RAND_LEN);
214
215	if (hexstr2bin(pos, data->ik, EAP_AKA_IK_LEN) < 0)
216		goto invalid;
217	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: IK", data->ik, EAP_AKA_IK_LEN);
218	pos += EAP_AKA_IK_LEN * 2;
219	if (*pos != ':')
220		goto invalid;
221	pos++;
222
223	if (hexstr2bin(pos, data->ck, EAP_AKA_CK_LEN) < 0)
224		goto invalid;
225	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: CK", data->ck, EAP_AKA_CK_LEN);
226	pos += EAP_AKA_CK_LEN * 2;
227	if (*pos != ':')
228		goto invalid;
229	pos++;
230
231	data->res_len = os_strlen(pos) / 2;
232	if (data->res_len > EAP_AKA_RES_MAX_LEN) {
233		data->res_len = 0;
234		goto invalid;
235	}
236	if (hexstr2bin(pos, data->res, data->res_len) < 0)
237		goto invalid;
238	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: RES", data->res, data->res_len);
239
240	os_free(resp);
241	return 0;
242
243invalid:
244	wpa_printf(MSG_DEBUG, "EAP-AKA: Invalid external USIM processing UMTS-AUTH response");
245	os_free(resp);
246	return -1;
247}
248
249
250static int eap_aka_umts_auth(struct eap_sm *sm, struct eap_aka_data *data)
251{
252	struct eap_peer_config *conf;
253
254	wpa_printf(MSG_DEBUG, "EAP-AKA: UMTS authentication algorithm");
255
256	conf = eap_get_config(sm);
257	if (conf == NULL)
258		return -1;
259
260	if (sm->external_sim) {
261		if (conf->external_sim_resp)
262			return eap_aka_ext_sim_result(sm, data, conf);
263		else
264			return eap_aka_ext_sim_req(sm, data);
265	}
266
267	if (conf->pcsc) {
268		return scard_umts_auth(sm->scard_ctx, data->rand,
269				       data->autn, data->res, &data->res_len,
270				       data->ik, data->ck, data->auts);
271	}
272
273#ifdef CONFIG_USIM_SIMULATOR
274	if (conf->password) {
275		u8 opc[16], k[16], sqn[6];
276		const char *pos;
277		wpa_printf(MSG_DEBUG, "EAP-AKA: Use internal Milenage "
278			   "implementation for UMTS authentication");
279		if (conf->password_len < 78) {
280			wpa_printf(MSG_DEBUG, "EAP-AKA: invalid Milenage "
281				   "password");
282			return -1;
283		}
284		pos = (const char *) conf->password;
285		if (hexstr2bin(pos, k, 16))
286			return -1;
287		pos += 32;
288		if (*pos != ':')
289			return -1;
290		pos++;
291
292		if (hexstr2bin(pos, opc, 16))
293			return -1;
294		pos += 32;
295		if (*pos != ':')
296			return -1;
297		pos++;
298
299		if (hexstr2bin(pos, sqn, 6))
300			return -1;
301
302		return milenage_check(opc, k, sqn, data->rand, data->autn,
303				      data->ik, data->ck,
304				      data->res, &data->res_len, data->auts);
305	}
306#endif /* CONFIG_USIM_SIMULATOR */
307
308#ifdef CONFIG_USIM_HARDCODED
309	wpa_printf(MSG_DEBUG, "EAP-AKA: Use hardcoded Kc and SRES values for "
310		   "testing");
311
312	/* These hardcoded Kc and SRES values are used for testing.
313	 * Could consider making them configurable. */
314	os_memset(data->res, '2', EAP_AKA_RES_MAX_LEN);
315	data->res_len = EAP_AKA_RES_MAX_LEN;
316	os_memset(data->ik, '3', EAP_AKA_IK_LEN);
317	os_memset(data->ck, '4', EAP_AKA_CK_LEN);
318	{
319		u8 autn[EAP_AKA_AUTN_LEN];
320		os_memset(autn, '1', EAP_AKA_AUTN_LEN);
321		if (os_memcmp_const(autn, data->autn, EAP_AKA_AUTN_LEN) != 0) {
322			wpa_printf(MSG_WARNING, "EAP-AKA: AUTN did not match "
323				   "with expected value");
324			return -1;
325		}
326	}
327#if 0
328	{
329		static int test_resync = 1;
330		if (test_resync) {
331			/* Test Resynchronization */
332			test_resync = 0;
333			return -2;
334		}
335	}
336#endif
337	return 0;
338
339#else /* CONFIG_USIM_HARDCODED */
340
341	wpa_printf(MSG_DEBUG, "EAP-AKA: No UMTS authentication algorithm "
342		   "enabled");
343	return -1;
344
345#endif /* CONFIG_USIM_HARDCODED */
346}
347
348
349#define CLEAR_PSEUDONYM	0x01
350#define CLEAR_REAUTH_ID	0x02
351#define CLEAR_EAP_ID	0x04
352
353static void eap_aka_clear_identities(struct eap_sm *sm,
354				     struct eap_aka_data *data, int id)
355{
356	if ((id & CLEAR_PSEUDONYM) && data->pseudonym) {
357		wpa_printf(MSG_DEBUG, "EAP-AKA: forgetting old pseudonym");
358		os_free(data->pseudonym);
359		data->pseudonym = NULL;
360		data->pseudonym_len = 0;
361		if (data->use_pseudonym)
362			eap_set_anon_id(sm, NULL, 0);
363	}
364	if ((id & CLEAR_REAUTH_ID) && data->reauth_id) {
365		wpa_printf(MSG_DEBUG, "EAP-AKA: forgetting old reauth_id");
366		os_free(data->reauth_id);
367		data->reauth_id = NULL;
368		data->reauth_id_len = 0;
369	}
370	if ((id & CLEAR_EAP_ID) && data->last_eap_identity) {
371		wpa_printf(MSG_DEBUG, "EAP-AKA: forgetting old eap_id");
372		os_free(data->last_eap_identity);
373		data->last_eap_identity = NULL;
374		data->last_eap_identity_len = 0;
375	}
376}
377
378
379static int eap_aka_learn_ids(struct eap_sm *sm, struct eap_aka_data *data,
380			     struct eap_sim_attrs *attr)
381{
382	if (attr->next_pseudonym) {
383		const u8 *identity = NULL;
384		size_t identity_len = 0;
385		const u8 *realm = NULL;
386		size_t realm_len = 0;
387
388		wpa_hexdump_ascii(MSG_DEBUG,
389				  "EAP-AKA: (encr) AT_NEXT_PSEUDONYM",
390				  attr->next_pseudonym,
391				  attr->next_pseudonym_len);
392		os_free(data->pseudonym);
393		/* Look for the realm of the permanent identity */
394		identity = eap_get_config_identity(sm, &identity_len);
395		if (identity) {
396			for (realm = identity, realm_len = identity_len;
397			     realm_len > 0; realm_len--, realm++) {
398				if (*realm == '@')
399					break;
400			}
401		}
402		data->pseudonym = os_malloc(attr->next_pseudonym_len +
403					    realm_len);
404		if (data->pseudonym == NULL) {
405			wpa_printf(MSG_INFO, "EAP-AKA: (encr) No memory for "
406				   "next pseudonym");
407			data->pseudonym_len = 0;
408			return -1;
409		}
410		os_memcpy(data->pseudonym, attr->next_pseudonym,
411			  attr->next_pseudonym_len);
412		if (realm_len) {
413			os_memcpy(data->pseudonym + attr->next_pseudonym_len,
414				  realm, realm_len);
415		}
416		data->pseudonym_len = attr->next_pseudonym_len + realm_len;
417		if (data->use_pseudonym)
418			eap_set_anon_id(sm, data->pseudonym,
419					data->pseudonym_len);
420	}
421
422	if (attr->next_reauth_id) {
423		os_free(data->reauth_id);
424		data->reauth_id = os_memdup(attr->next_reauth_id,
425					    attr->next_reauth_id_len);
426		if (data->reauth_id == NULL) {
427			wpa_printf(MSG_INFO, "EAP-AKA: (encr) No memory for "
428				   "next reauth_id");
429			data->reauth_id_len = 0;
430			return -1;
431		}
432		data->reauth_id_len = attr->next_reauth_id_len;
433		wpa_hexdump_ascii(MSG_DEBUG,
434				  "EAP-AKA: (encr) AT_NEXT_REAUTH_ID",
435				  data->reauth_id,
436				  data->reauth_id_len);
437	}
438
439	return 0;
440}
441
442
443static int eap_aka_add_id_msg(struct eap_aka_data *data,
444			      const struct wpabuf *msg)
445{
446	if (msg == NULL)
447		return -1;
448
449	if (data->id_msgs == NULL) {
450		data->id_msgs = wpabuf_dup(msg);
451		return data->id_msgs == NULL ? -1 : 0;
452	}
453
454	if (wpabuf_resize(&data->id_msgs, wpabuf_len(msg)) < 0)
455		return -1;
456	wpabuf_put_buf(data->id_msgs, msg);
457
458	return 0;
459}
460
461
462static void eap_aka_add_checkcode(struct eap_aka_data *data,
463				  struct eap_sim_msg *msg)
464{
465	const u8 *addr;
466	size_t len;
467	u8 hash[SHA256_MAC_LEN];
468
469	wpa_printf(MSG_DEBUG, "   AT_CHECKCODE");
470
471	if (data->id_msgs == NULL) {
472		/*
473		 * No EAP-AKA/Identity packets were exchanged - send empty
474		 * checkcode.
475		 */
476		eap_sim_msg_add(msg, EAP_SIM_AT_CHECKCODE, 0, NULL, 0);
477		return;
478	}
479
480	/* Checkcode is SHA1/SHA256 hash over all EAP-AKA/Identity packets. */
481	addr = wpabuf_head(data->id_msgs);
482	len = wpabuf_len(data->id_msgs);
483	wpa_hexdump(MSG_MSGDUMP, "EAP-AKA: AT_CHECKCODE data", addr, len);
484#ifdef EAP_AKA_PRIME
485	if (data->eap_method == EAP_TYPE_AKA_PRIME)
486		sha256_vector(1, &addr, &len, hash);
487	else
488#endif /* EAP_AKA_PRIME */
489		sha1_vector(1, &addr, &len, hash);
490
491	eap_sim_msg_add(msg, EAP_SIM_AT_CHECKCODE, 0, hash,
492			data->eap_method == EAP_TYPE_AKA_PRIME ?
493			EAP_AKA_PRIME_CHECKCODE_LEN : EAP_AKA_CHECKCODE_LEN);
494}
495
496
497static int eap_aka_verify_checkcode(struct eap_aka_data *data,
498				    const u8 *checkcode, size_t checkcode_len)
499{
500	const u8 *addr;
501	size_t len;
502	u8 hash[SHA256_MAC_LEN];
503	size_t hash_len;
504
505	if (checkcode == NULL)
506		return -1;
507
508	if (data->id_msgs == NULL) {
509		if (checkcode_len != 0) {
510			wpa_printf(MSG_DEBUG, "EAP-AKA: Checkcode from server "
511				   "indicates that AKA/Identity messages were "
512				   "used, but they were not");
513			return -1;
514		}
515		return 0;
516	}
517
518	hash_len = data->eap_method == EAP_TYPE_AKA_PRIME ?
519		EAP_AKA_PRIME_CHECKCODE_LEN : EAP_AKA_CHECKCODE_LEN;
520
521	if (checkcode_len != hash_len) {
522		wpa_printf(MSG_DEBUG, "EAP-AKA: Checkcode from server "
523			   "indicates that AKA/Identity message were not "
524			   "used, but they were");
525		return -1;
526	}
527
528	/* Checkcode is SHA1/SHA256 hash over all EAP-AKA/Identity packets. */
529	addr = wpabuf_head(data->id_msgs);
530	len = wpabuf_len(data->id_msgs);
531#ifdef EAP_AKA_PRIME
532	if (data->eap_method == EAP_TYPE_AKA_PRIME)
533		sha256_vector(1, &addr, &len, hash);
534	else
535#endif /* EAP_AKA_PRIME */
536		sha1_vector(1, &addr, &len, hash);
537
538	if (os_memcmp_const(hash, checkcode, hash_len) != 0) {
539		wpa_printf(MSG_DEBUG, "EAP-AKA: Mismatch in AT_CHECKCODE");
540		return -1;
541	}
542
543	return 0;
544}
545
546
547static struct wpabuf * eap_aka_client_error(struct eap_aka_data *data, u8 id,
548					    int err)
549{
550	struct eap_sim_msg *msg;
551
552	eap_aka_state(data, FAILURE);
553	data->num_id_req = 0;
554	data->num_notification = 0;
555
556	wpa_printf(MSG_DEBUG, "EAP-AKA: Send Client-Error (error code %d)",
557		   err);
558	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
559			       EAP_AKA_SUBTYPE_CLIENT_ERROR);
560	eap_sim_msg_add(msg, EAP_SIM_AT_CLIENT_ERROR_CODE, err, NULL, 0);
561	return eap_sim_msg_finish(msg, data->eap_method, NULL, NULL, 0);
562}
563
564
565static struct wpabuf * eap_aka_authentication_reject(struct eap_aka_data *data,
566						     u8 id)
567{
568	struct eap_sim_msg *msg;
569
570	eap_aka_state(data, FAILURE);
571	data->num_id_req = 0;
572	data->num_notification = 0;
573
574	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Authentication-Reject "
575		   "(id=%d)", id);
576	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
577			       EAP_AKA_SUBTYPE_AUTHENTICATION_REJECT);
578	return eap_sim_msg_finish(msg, data->eap_method, NULL, NULL, 0);
579}
580
581
582static struct wpabuf * eap_aka_synchronization_failure(
583	struct eap_aka_data *data, u8 id, struct eap_sim_attrs *attr)
584{
585	struct eap_sim_msg *msg;
586
587	data->num_id_req = 0;
588	data->num_notification = 0;
589
590	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Synchronization-Failure "
591		   "(id=%d)", id);
592	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
593			       EAP_AKA_SUBTYPE_SYNCHRONIZATION_FAILURE);
594	wpa_printf(MSG_DEBUG, "   AT_AUTS");
595	eap_sim_msg_add_full(msg, EAP_SIM_AT_AUTS, data->auts,
596			     EAP_AKA_AUTS_LEN);
597	if (data->eap_method == EAP_TYPE_AKA_PRIME) {
598		size_t i;
599
600		for (i = 0; i < attr->kdf_count; i++) {
601			wpa_printf(MSG_DEBUG, "   AT_KDF");
602			eap_sim_msg_add(msg, EAP_SIM_AT_KDF, attr->kdf[i],
603					NULL, 0);
604		}
605	}
606	return eap_sim_msg_finish(msg, data->eap_method, NULL, NULL, 0);
607}
608
609
610static struct wpabuf * eap_aka_response_identity(struct eap_sm *sm,
611						 struct eap_aka_data *data,
612						 u8 id,
613						 enum eap_sim_id_req id_req)
614{
615	const u8 *identity = NULL;
616	size_t identity_len = 0;
617	struct eap_sim_msg *msg;
618
619	data->reauth = 0;
620	if (id_req == ANY_ID && data->reauth_id) {
621		identity = data->reauth_id;
622		identity_len = data->reauth_id_len;
623		data->reauth = 1;
624	} else if ((id_req == ANY_ID || id_req == FULLAUTH_ID) &&
625		   data->pseudonym) {
626		identity = data->pseudonym;
627		identity_len = data->pseudonym_len;
628		eap_aka_clear_identities(sm, data, CLEAR_REAUTH_ID);
629	} else if (id_req != NO_ID_REQ) {
630		identity = eap_get_config_identity(sm, &identity_len);
631		if (identity) {
632			eap_aka_clear_identities(sm, data, CLEAR_PSEUDONYM |
633						 CLEAR_REAUTH_ID);
634		}
635	}
636	if (id_req != NO_ID_REQ)
637		eap_aka_clear_identities(sm, data, CLEAR_EAP_ID);
638
639	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Identity (id=%d)", id);
640	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
641			       EAP_AKA_SUBTYPE_IDENTITY);
642
643	if (identity) {
644		wpa_hexdump_ascii(MSG_DEBUG, "   AT_IDENTITY",
645				  identity, identity_len);
646		eap_sim_msg_add(msg, EAP_SIM_AT_IDENTITY, identity_len,
647				identity, identity_len);
648	}
649
650	return eap_sim_msg_finish(msg, data->eap_method, NULL, NULL, 0);
651}
652
653
654static struct wpabuf * eap_aka_response_challenge(struct eap_aka_data *data,
655						  u8 id)
656{
657	struct eap_sim_msg *msg;
658
659	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Challenge (id=%d)", id);
660	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
661			       EAP_AKA_SUBTYPE_CHALLENGE);
662	wpa_printf(MSG_DEBUG, "   AT_RES");
663	eap_sim_msg_add(msg, EAP_SIM_AT_RES, data->res_len * 8,
664			data->res, data->res_len);
665	eap_aka_add_checkcode(data, msg);
666	if (data->use_result_ind) {
667		wpa_printf(MSG_DEBUG, "   AT_RESULT_IND");
668		eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
669	}
670	wpa_printf(MSG_DEBUG, "   AT_MAC");
671	eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
672	return eap_sim_msg_finish(msg, data->eap_method, data->k_aut, (u8 *) "",
673				  0);
674}
675
676
677static struct wpabuf * eap_aka_response_reauth(struct eap_aka_data *data,
678					       u8 id, int counter_too_small,
679					       const u8 *nonce_s)
680{
681	struct eap_sim_msg *msg;
682	unsigned int counter;
683
684	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Reauthentication (id=%d)",
685		   id);
686	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
687			       EAP_AKA_SUBTYPE_REAUTHENTICATION);
688	wpa_printf(MSG_DEBUG, "   AT_IV");
689	wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
690	eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA);
691
692	if (counter_too_small) {
693		wpa_printf(MSG_DEBUG, "   *AT_COUNTER_TOO_SMALL");
694		eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER_TOO_SMALL, 0, NULL, 0);
695		counter = data->counter_too_small;
696	} else
697		counter = data->counter;
698
699	wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", counter);
700	eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0);
701
702	if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) {
703		wpa_printf(MSG_WARNING, "EAP-AKA: Failed to encrypt "
704			   "AT_ENCR_DATA");
705		eap_sim_msg_free(msg);
706		return NULL;
707	}
708	eap_aka_add_checkcode(data, msg);
709	if (data->use_result_ind) {
710		wpa_printf(MSG_DEBUG, "   AT_RESULT_IND");
711		eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
712	}
713	wpa_printf(MSG_DEBUG, "   AT_MAC");
714	eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
715	return eap_sim_msg_finish(msg, data->eap_method, data->k_aut, nonce_s,
716				  EAP_SIM_NONCE_S_LEN);
717}
718
719
720static struct wpabuf * eap_aka_response_notification(struct eap_aka_data *data,
721						     u8 id, u16 notification)
722{
723	struct eap_sim_msg *msg;
724	u8 *k_aut = (notification & 0x4000) == 0 ? data->k_aut : NULL;
725
726	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Notification (id=%d)", id);
727	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
728			       EAP_AKA_SUBTYPE_NOTIFICATION);
729	if (k_aut && data->reauth) {
730		wpa_printf(MSG_DEBUG, "   AT_IV");
731		wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
732		eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
733					   EAP_SIM_AT_ENCR_DATA);
734		wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", data->counter);
735		eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
736				NULL, 0);
737		if (eap_sim_msg_add_encr_end(msg, data->k_encr,
738					     EAP_SIM_AT_PADDING)) {
739			wpa_printf(MSG_WARNING, "EAP-AKA: Failed to encrypt "
740				   "AT_ENCR_DATA");
741			eap_sim_msg_free(msg);
742			return NULL;
743		}
744	}
745	if (k_aut) {
746		wpa_printf(MSG_DEBUG, "   AT_MAC");
747		eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
748	}
749	return eap_sim_msg_finish(msg, data->eap_method, k_aut, (u8 *) "", 0);
750}
751
752
753static struct wpabuf * eap_aka_process_identity(struct eap_sm *sm,
754						struct eap_aka_data *data,
755						u8 id,
756						const struct wpabuf *reqData,
757						struct eap_sim_attrs *attr)
758{
759	int id_error;
760	struct wpabuf *buf;
761
762	wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Identity");
763
764	id_error = 0;
765	switch (attr->id_req) {
766	case NO_ID_REQ:
767		break;
768	case ANY_ID:
769		if (data->num_id_req > 0)
770			id_error++;
771		data->num_id_req++;
772		break;
773	case FULLAUTH_ID:
774		if (data->num_id_req > 1)
775			id_error++;
776		data->num_id_req++;
777		break;
778	case PERMANENT_ID:
779		if (data->num_id_req > 2)
780			id_error++;
781		data->num_id_req++;
782		break;
783	}
784	if (id_error) {
785		wpa_printf(MSG_INFO, "EAP-AKA: Too many ID requests "
786			   "used within one authentication");
787		return eap_aka_client_error(data, id,
788					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
789	}
790
791	buf = eap_aka_response_identity(sm, data, id, attr->id_req);
792
793	if (data->prev_id != id) {
794		eap_aka_add_id_msg(data, reqData);
795		eap_aka_add_id_msg(data, buf);
796		data->prev_id = id;
797	}
798
799	return buf;
800}
801
802
803static int eap_aka_verify_mac(struct eap_aka_data *data,
804			      const struct wpabuf *req,
805			      const u8 *mac, const u8 *extra,
806			      size_t extra_len)
807{
808	if (data->eap_method == EAP_TYPE_AKA_PRIME)
809		return eap_sim_verify_mac_sha256(data->k_aut, req, mac, extra,
810						 extra_len);
811	return eap_sim_verify_mac(data->k_aut, req, mac, extra, extra_len);
812}
813
814
815#ifdef EAP_AKA_PRIME
816static struct wpabuf * eap_aka_prime_kdf_select(struct eap_aka_data *data,
817						u8 id, u16 kdf)
818{
819	struct eap_sim_msg *msg;
820
821	data->kdf_negotiation = 1;
822	data->kdf = kdf;
823	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Challenge (id=%d) (KDF "
824		   "select)", id);
825	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
826			       EAP_AKA_SUBTYPE_CHALLENGE);
827	wpa_printf(MSG_DEBUG, "   AT_KDF");
828	eap_sim_msg_add(msg, EAP_SIM_AT_KDF, kdf, NULL, 0);
829	return eap_sim_msg_finish(msg, data->eap_method, NULL, NULL, 0);
830}
831
832
833static struct wpabuf * eap_aka_prime_kdf_neg(struct eap_aka_data *data,
834					     u8 id, struct eap_sim_attrs *attr)
835{
836	size_t i;
837
838	for (i = 0; i < attr->kdf_count; i++) {
839		if (attr->kdf[i] == EAP_AKA_PRIME_KDF) {
840			os_memcpy(data->last_kdf_attrs, attr->kdf,
841				  sizeof(u16) * attr->kdf_count);
842			data->last_kdf_count = attr->kdf_count;
843			return eap_aka_prime_kdf_select(data, id,
844							EAP_AKA_PRIME_KDF);
845		}
846	}
847
848	/* No matching KDF found - fail authentication as if AUTN had been
849	 * incorrect */
850	return eap_aka_authentication_reject(data, id);
851}
852
853
854static int eap_aka_prime_kdf_valid(struct eap_aka_data *data,
855				   struct eap_sim_attrs *attr)
856{
857	size_t i, j;
858
859	if (attr->kdf_count == 0)
860		return 0;
861
862	/* The only allowed (and required) duplication of a KDF is the addition
863	 * of the selected KDF into the beginning of the list. */
864
865	if (data->kdf_negotiation) {
866		/* When the peer receives the new EAP-Request/AKA'-Challenge
867		 * message, must check only requested change occurred in the
868		 * list of AT_KDF attributes. If there are any other changes,
869		 * the peer must behave like the case that AT_MAC had been
870		 * incorrect and authentication is failed. These are defined in
871		 * EAP-AKA' specification RFC 5448, Section 3.2. */
872		if (attr->kdf[0] != data->kdf) {
873			wpa_printf(MSG_WARNING, "EAP-AKA': The server did not "
874				   "accept the selected KDF");
875			return -1;
876		}
877
878		if (attr->kdf_count > EAP_AKA_PRIME_KDF_MAX ||
879		    attr->kdf_count != data->last_kdf_count + 1) {
880			wpa_printf(MSG_WARNING,
881				   "EAP-AKA': The length of KDF attributes is wrong");
882			return -1;
883		}
884
885		for (i = 1; i < attr->kdf_count; i++) {
886			if (attr->kdf[i] != data->last_kdf_attrs[i - 1]) {
887				wpa_printf(MSG_WARNING,
888					   "EAP-AKA': The KDF attributes except selected KDF are not same as original one");
889				return -1;
890			}
891		}
892	}
893
894	for (i = data->kdf ? 1 : 0; i < attr->kdf_count; i++) {
895		for (j = i + 1; j < attr->kdf_count; j++) {
896			if (attr->kdf[i] == attr->kdf[j]) {
897				wpa_printf(MSG_WARNING, "EAP-AKA': The server "
898					   "included a duplicated KDF");
899				return 0;
900			}
901		}
902	}
903
904	return 1;
905}
906#endif /* EAP_AKA_PRIME */
907
908
909static struct wpabuf * eap_aka_process_challenge(struct eap_sm *sm,
910						 struct eap_aka_data *data,
911						 u8 id,
912						 const struct wpabuf *reqData,
913						 struct eap_sim_attrs *attr)
914{
915	const u8 *identity;
916	size_t identity_len;
917	int res;
918	struct eap_sim_attrs eattr;
919
920	wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Challenge");
921
922	if (attr->checkcode &&
923	    eap_aka_verify_checkcode(data, attr->checkcode,
924				     attr->checkcode_len)) {
925		wpa_printf(MSG_WARNING, "EAP-AKA: Invalid AT_CHECKCODE in the "
926			   "message");
927		return eap_aka_client_error(data, id,
928					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
929	}
930
931#ifdef EAP_AKA_PRIME
932	if (data->eap_method == EAP_TYPE_AKA_PRIME) {
933		if (!attr->kdf_input || attr->kdf_input_len == 0) {
934			wpa_printf(MSG_WARNING, "EAP-AKA': Challenge message "
935				   "did not include non-empty AT_KDF_INPUT");
936			/* Fail authentication as if AUTN had been incorrect */
937			return eap_aka_authentication_reject(data, id);
938		}
939		os_free(data->network_name);
940		data->network_name = os_memdup(attr->kdf_input,
941					       attr->kdf_input_len);
942		if (data->network_name == NULL) {
943			wpa_printf(MSG_WARNING, "EAP-AKA': No memory for "
944				   "storing Network Name");
945			return eap_aka_authentication_reject(data, id);
946		}
947		data->network_name_len = attr->kdf_input_len;
948		wpa_hexdump_ascii(MSG_DEBUG, "EAP-AKA': Network Name "
949				  "(AT_KDF_INPUT)",
950				  data->network_name, data->network_name_len);
951		/* TODO: check Network Name per 3GPP.33.402 */
952
953		res = eap_aka_prime_kdf_valid(data, attr);
954		if (res == 0)
955			return eap_aka_authentication_reject(data, id);
956		else if (res == -1)
957			return eap_aka_client_error(
958				data, id, EAP_AKA_UNABLE_TO_PROCESS_PACKET);
959
960		if (attr->kdf[0] != EAP_AKA_PRIME_KDF)
961			return eap_aka_prime_kdf_neg(data, id, attr);
962
963		data->kdf = EAP_AKA_PRIME_KDF;
964		wpa_printf(MSG_DEBUG, "EAP-AKA': KDF %d selected", data->kdf);
965	}
966
967	if (data->eap_method == EAP_TYPE_AKA && attr->bidding) {
968		u16 flags = WPA_GET_BE16(attr->bidding);
969		if ((flags & EAP_AKA_BIDDING_FLAG_D) &&
970		    eap_allowed_method(sm, EAP_VENDOR_IETF,
971				       EAP_TYPE_AKA_PRIME)) {
972			wpa_printf(MSG_WARNING, "EAP-AKA: Bidding down from "
973				   "AKA' to AKA detected");
974			/* Fail authentication as if AUTN had been incorrect */
975			return eap_aka_authentication_reject(data, id);
976		}
977	}
978#endif /* EAP_AKA_PRIME */
979
980	data->reauth = 0;
981	if (!attr->mac || !attr->rand || !attr->autn) {
982		wpa_printf(MSG_WARNING, "EAP-AKA: Challenge message "
983			   "did not include%s%s%s",
984			   !attr->mac ? " AT_MAC" : "",
985			   !attr->rand ? " AT_RAND" : "",
986			   !attr->autn ? " AT_AUTN" : "");
987		return eap_aka_client_error(data, id,
988					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
989	}
990	os_memcpy(data->rand, attr->rand, EAP_AKA_RAND_LEN);
991	os_memcpy(data->autn, attr->autn, EAP_AKA_AUTN_LEN);
992
993	res = eap_aka_umts_auth(sm, data);
994	if (res == -1) {
995		wpa_printf(MSG_WARNING, "EAP-AKA: UMTS authentication "
996			   "failed (AUTN)");
997		return eap_aka_authentication_reject(data, id);
998	} else if (res == -2) {
999		wpa_printf(MSG_WARNING, "EAP-AKA: UMTS authentication "
1000			   "failed (AUTN seq# -> AUTS)");
1001		return eap_aka_synchronization_failure(data, id, attr);
1002	} else if (res > 0) {
1003		wpa_printf(MSG_DEBUG, "EAP-AKA: Wait for external USIM processing");
1004		return NULL;
1005	} else if (res) {
1006		wpa_printf(MSG_WARNING, "EAP-AKA: UMTS authentication failed");
1007		return eap_aka_client_error(data, id,
1008					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1009	}
1010#ifdef EAP_AKA_PRIME
1011	if (data->eap_method == EAP_TYPE_AKA_PRIME) {
1012		/* Note: AUTN = (SQN ^ AK) || AMF || MAC which gives us the
1013		 * needed 6-octet SQN ^ AK for CK',IK' derivation */
1014		u16 amf = WPA_GET_BE16(data->autn + 6);
1015		if (!(amf & 0x8000)) {
1016			wpa_printf(MSG_WARNING, "EAP-AKA': AMF separation bit "
1017				   "not set (AMF=0x%4x)", amf);
1018			return eap_aka_authentication_reject(data, id);
1019		}
1020		eap_aka_prime_derive_ck_ik_prime(data->ck, data->ik,
1021						 data->autn,
1022						 data->network_name,
1023						 data->network_name_len);
1024	}
1025#endif /* EAP_AKA_PRIME */
1026	if (data->last_eap_identity) {
1027		identity = data->last_eap_identity;
1028		identity_len = data->last_eap_identity_len;
1029	} else if (data->pseudonym) {
1030		identity = data->pseudonym;
1031		identity_len = data->pseudonym_len;
1032	} else {
1033		struct eap_peer_config *config;
1034
1035		config = eap_get_config(sm);
1036		if (config && config->imsi_identity) {
1037			identity = config->imsi_identity;
1038			identity_len = config->imsi_identity_len;
1039		} else {
1040			identity = eap_get_config_identity(sm, &identity_len);
1041		}
1042	}
1043	wpa_hexdump_ascii(MSG_DEBUG, "EAP-AKA: Selected identity for MK "
1044			  "derivation", identity, identity_len);
1045	if (data->eap_method == EAP_TYPE_AKA_PRIME) {
1046		eap_aka_prime_derive_keys(identity, identity_len, data->ik,
1047					  data->ck, data->k_encr, data->k_aut,
1048					  data->k_re, data->msk, data->emsk);
1049	} else {
1050		eap_aka_derive_mk(identity, identity_len, data->ik, data->ck,
1051				  data->mk);
1052		eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut,
1053				    data->msk, data->emsk);
1054	}
1055	if (eap_aka_verify_mac(data, reqData, attr->mac, (u8 *) "", 0)) {
1056		wpa_printf(MSG_WARNING, "EAP-AKA: Challenge message "
1057			   "used invalid AT_MAC");
1058		return eap_aka_client_error(data, id,
1059					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1060	}
1061
1062	/* Old reauthentication identity must not be used anymore. In
1063	 * other words, if no new identities are received, full
1064	 * authentication will be used on next reauthentication (using
1065	 * pseudonym identity or permanent identity). */
1066	eap_aka_clear_identities(sm, data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
1067
1068	if (attr->encr_data) {
1069		u8 *decrypted;
1070		decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
1071					       attr->encr_data_len, attr->iv,
1072					       &eattr, 0);
1073		if (decrypted == NULL) {
1074			return eap_aka_client_error(
1075				data, id, EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1076		}
1077		eap_aka_learn_ids(sm, data, &eattr);
1078		os_free(decrypted);
1079	}
1080
1081	if (data->result_ind && attr->result_ind)
1082		data->use_result_ind = 1;
1083
1084	if (data->state != FAILURE) {
1085		eap_aka_state(data, data->use_result_ind ?
1086			      RESULT_SUCCESS : SUCCESS);
1087	}
1088
1089	data->num_id_req = 0;
1090	data->num_notification = 0;
1091	/* RFC 4187 specifies that counter is initialized to one after
1092	 * fullauth, but initializing it to zero makes it easier to implement
1093	 * reauth verification. */
1094	data->counter = 0;
1095	return eap_aka_response_challenge(data, id);
1096}
1097
1098
1099static int eap_aka_process_notification_reauth(struct eap_aka_data *data,
1100					       struct eap_sim_attrs *attr)
1101{
1102	struct eap_sim_attrs eattr;
1103	u8 *decrypted;
1104
1105	if (attr->encr_data == NULL || attr->iv == NULL) {
1106		wpa_printf(MSG_WARNING, "EAP-AKA: Notification message after "
1107			   "reauth did not include encrypted data");
1108		return -1;
1109	}
1110
1111	decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
1112				       attr->encr_data_len, attr->iv, &eattr,
1113				       0);
1114	if (decrypted == NULL) {
1115		wpa_printf(MSG_WARNING, "EAP-AKA: Failed to parse encrypted "
1116			   "data from notification message");
1117		return -1;
1118	}
1119
1120	if (eattr.counter < 0 || (size_t) eattr.counter != data->counter) {
1121		wpa_printf(MSG_WARNING, "EAP-AKA: Counter in notification "
1122			   "message does not match with counter in reauth "
1123			   "message");
1124		os_free(decrypted);
1125		return -1;
1126	}
1127
1128	os_free(decrypted);
1129	return 0;
1130}
1131
1132
1133static int eap_aka_process_notification_auth(struct eap_aka_data *data,
1134					     const struct wpabuf *reqData,
1135					     struct eap_sim_attrs *attr)
1136{
1137	if (attr->mac == NULL) {
1138		wpa_printf(MSG_INFO, "EAP-AKA: no AT_MAC in after_auth "
1139			   "Notification message");
1140		return -1;
1141	}
1142
1143	if (eap_aka_verify_mac(data, reqData, attr->mac, (u8 *) "", 0)) {
1144		wpa_printf(MSG_WARNING, "EAP-AKA: Notification message "
1145			   "used invalid AT_MAC");
1146		return -1;
1147	}
1148
1149	if (data->reauth &&
1150	    eap_aka_process_notification_reauth(data, attr)) {
1151		wpa_printf(MSG_WARNING, "EAP-AKA: Invalid notification "
1152			   "message after reauth");
1153		return -1;
1154	}
1155
1156	return 0;
1157}
1158
1159
1160static struct wpabuf * eap_aka_process_notification(
1161	struct eap_sm *sm, struct eap_aka_data *data, u8 id,
1162	const struct wpabuf *reqData, struct eap_sim_attrs *attr)
1163{
1164	wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Notification");
1165	if (data->num_notification > 0) {
1166		wpa_printf(MSG_INFO, "EAP-AKA: too many notification "
1167			   "rounds (only one allowed)");
1168		return eap_aka_client_error(data, id,
1169					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1170	}
1171	data->num_notification++;
1172	if (attr->notification == -1) {
1173		wpa_printf(MSG_INFO, "EAP-AKA: no AT_NOTIFICATION in "
1174			   "Notification message");
1175		return eap_aka_client_error(data, id,
1176					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1177	}
1178
1179	if ((attr->notification & 0x4000) == 0 &&
1180	    eap_aka_process_notification_auth(data, reqData, attr)) {
1181		return eap_aka_client_error(data, id,
1182					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1183	}
1184
1185	eap_sim_report_notification(sm->msg_ctx, attr->notification, 1);
1186	if (attr->notification >= 0 && attr->notification < 32768) {
1187		data->error_code = attr->notification;
1188		eap_aka_state(data, FAILURE);
1189	} else if (attr->notification == EAP_SIM_SUCCESS &&
1190		   data->state == RESULT_SUCCESS)
1191		eap_aka_state(data, SUCCESS);
1192	return eap_aka_response_notification(data, id, attr->notification);
1193}
1194
1195
1196static struct wpabuf * eap_aka_process_reauthentication(
1197	struct eap_sm *sm, struct eap_aka_data *data, u8 id,
1198	const struct wpabuf *reqData, struct eap_sim_attrs *attr)
1199{
1200	struct eap_sim_attrs eattr;
1201	u8 *decrypted;
1202
1203	wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Reauthentication");
1204
1205	if (attr->checkcode &&
1206	    eap_aka_verify_checkcode(data, attr->checkcode,
1207				     attr->checkcode_len)) {
1208		wpa_printf(MSG_WARNING, "EAP-AKA: Invalid AT_CHECKCODE in the "
1209			   "message");
1210		return eap_aka_client_error(data, id,
1211					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1212	}
1213
1214	if (data->reauth_id == NULL) {
1215		wpa_printf(MSG_WARNING, "EAP-AKA: Server is trying "
1216			   "reauthentication, but no reauth_id available");
1217		return eap_aka_client_error(data, id,
1218					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1219	}
1220
1221	data->reauth = 1;
1222	if (eap_aka_verify_mac(data, reqData, attr->mac, (u8 *) "", 0)) {
1223		wpa_printf(MSG_WARNING, "EAP-AKA: Reauthentication "
1224			   "did not have valid AT_MAC");
1225		return eap_aka_client_error(data, id,
1226					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1227	}
1228
1229	if (attr->encr_data == NULL || attr->iv == NULL) {
1230		wpa_printf(MSG_WARNING, "EAP-AKA: Reauthentication "
1231			   "message did not include encrypted data");
1232		return eap_aka_client_error(data, id,
1233					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1234	}
1235
1236	decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
1237				       attr->encr_data_len, attr->iv, &eattr,
1238				       0);
1239	if (decrypted == NULL) {
1240		wpa_printf(MSG_WARNING, "EAP-AKA: Failed to parse encrypted "
1241			   "data from reauthentication message");
1242		return eap_aka_client_error(data, id,
1243					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1244	}
1245
1246	if (eattr.nonce_s == NULL || eattr.counter < 0) {
1247		wpa_printf(MSG_INFO, "EAP-AKA: (encr) No%s%s in reauth packet",
1248			   !eattr.nonce_s ? " AT_NONCE_S" : "",
1249			   eattr.counter < 0 ? " AT_COUNTER" : "");
1250		os_free(decrypted);
1251		return eap_aka_client_error(data, id,
1252					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1253	}
1254
1255	if (eattr.counter < 0 || (size_t) eattr.counter <= data->counter) {
1256		struct wpabuf *res;
1257		wpa_printf(MSG_INFO, "EAP-AKA: (encr) Invalid counter "
1258			   "(%d <= %d)", eattr.counter, data->counter);
1259		data->counter_too_small = eattr.counter;
1260
1261		/* Reply using Re-auth w/ AT_COUNTER_TOO_SMALL. The current
1262		 * reauth_id must not be used to start a new reauthentication.
1263		 * However, since it was used in the last EAP-Response-Identity
1264		 * packet, it has to saved for the following fullauth to be
1265		 * used in MK derivation. */
1266		os_free(data->last_eap_identity);
1267		data->last_eap_identity = data->reauth_id;
1268		data->last_eap_identity_len = data->reauth_id_len;
1269		data->reauth_id = NULL;
1270		data->reauth_id_len = 0;
1271
1272		res = eap_aka_response_reauth(data, id, 1, eattr.nonce_s);
1273		os_free(decrypted);
1274
1275		return res;
1276	}
1277	data->counter = eattr.counter;
1278
1279	os_memcpy(data->nonce_s, eattr.nonce_s, EAP_SIM_NONCE_S_LEN);
1280	wpa_hexdump(MSG_DEBUG, "EAP-AKA: (encr) AT_NONCE_S",
1281		    data->nonce_s, EAP_SIM_NONCE_S_LEN);
1282
1283	if (data->eap_method == EAP_TYPE_AKA_PRIME) {
1284		eap_aka_prime_derive_keys_reauth(data->k_re, data->counter,
1285						 data->reauth_id,
1286						 data->reauth_id_len,
1287						 data->nonce_s,
1288						 data->msk, data->emsk);
1289	} else {
1290		eap_sim_derive_keys_reauth(data->counter, data->reauth_id,
1291					   data->reauth_id_len,
1292					   data->nonce_s, data->mk,
1293					   data->msk, data->emsk);
1294	}
1295	eap_aka_clear_identities(sm, data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
1296	eap_aka_learn_ids(sm, data, &eattr);
1297
1298	if (data->result_ind && attr->result_ind)
1299		data->use_result_ind = 1;
1300
1301	if (data->state != FAILURE) {
1302		eap_aka_state(data, data->use_result_ind ?
1303			      RESULT_SUCCESS : SUCCESS);
1304	}
1305
1306	data->num_id_req = 0;
1307	data->num_notification = 0;
1308	if (data->counter > EAP_AKA_MAX_FAST_REAUTHS) {
1309		wpa_printf(MSG_DEBUG, "EAP-AKA: Maximum number of "
1310			   "fast reauths performed - force fullauth");
1311		eap_aka_clear_identities(sm, data,
1312					 CLEAR_REAUTH_ID | CLEAR_EAP_ID);
1313	}
1314	os_free(decrypted);
1315	return eap_aka_response_reauth(data, id, 0, data->nonce_s);
1316}
1317
1318
1319static struct wpabuf * eap_aka_process(struct eap_sm *sm, void *priv,
1320				       struct eap_method_ret *ret,
1321				       const struct wpabuf *reqData)
1322{
1323	struct eap_aka_data *data = priv;
1324	const struct eap_hdr *req;
1325	u8 subtype, id;
1326	struct wpabuf *res;
1327	const u8 *pos;
1328	struct eap_sim_attrs attr;
1329	size_t len;
1330
1331	wpa_hexdump_buf(MSG_DEBUG, "EAP-AKA: EAP data", reqData);
1332	if (eap_get_config_identity(sm, &len) == NULL) {
1333		wpa_printf(MSG_INFO, "EAP-AKA: Identity not configured");
1334		eap_sm_request_identity(sm);
1335		ret->ignore = TRUE;
1336		return NULL;
1337	}
1338
1339	pos = eap_hdr_validate(EAP_VENDOR_IETF, data->eap_method, reqData,
1340			       &len);
1341	if (pos == NULL || len < 3) {
1342		ret->ignore = TRUE;
1343		return NULL;
1344	}
1345	req = wpabuf_head(reqData);
1346	id = req->identifier;
1347	len = be_to_host16(req->length);
1348
1349	ret->ignore = FALSE;
1350	ret->methodState = METHOD_MAY_CONT;
1351	ret->decision = DECISION_FAIL;
1352	ret->allowNotifications = TRUE;
1353
1354	subtype = *pos++;
1355	wpa_printf(MSG_DEBUG, "EAP-AKA: Subtype=%d", subtype);
1356	pos += 2; /* Reserved */
1357
1358	if (eap_sim_parse_attr(pos, wpabuf_head_u8(reqData) + len, &attr,
1359			       data->eap_method == EAP_TYPE_AKA_PRIME ? 2 : 1,
1360			       0)) {
1361		res = eap_aka_client_error(data, id,
1362					   EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1363		goto done;
1364	}
1365
1366	switch (subtype) {
1367	case EAP_AKA_SUBTYPE_IDENTITY:
1368		res = eap_aka_process_identity(sm, data, id, reqData, &attr);
1369		break;
1370	case EAP_AKA_SUBTYPE_CHALLENGE:
1371		res = eap_aka_process_challenge(sm, data, id, reqData, &attr);
1372		break;
1373	case EAP_AKA_SUBTYPE_NOTIFICATION:
1374		res = eap_aka_process_notification(sm, data, id, reqData,
1375						   &attr);
1376		break;
1377	case EAP_AKA_SUBTYPE_REAUTHENTICATION:
1378		res = eap_aka_process_reauthentication(sm, data, id, reqData,
1379						       &attr);
1380		break;
1381	case EAP_AKA_SUBTYPE_CLIENT_ERROR:
1382		wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Client-Error");
1383		res = eap_aka_client_error(data, id,
1384					   EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1385		break;
1386	default:
1387		wpa_printf(MSG_DEBUG, "EAP-AKA: Unknown subtype=%d", subtype);
1388		res = eap_aka_client_error(data, id,
1389					   EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1390		break;
1391	}
1392
1393done:
1394	if (data->state == FAILURE) {
1395		ret->decision = DECISION_FAIL;
1396		ret->methodState = METHOD_DONE;
1397	} else if (data->state == SUCCESS) {
1398		ret->decision = data->use_result_ind ?
1399			DECISION_UNCOND_SUCC : DECISION_COND_SUCC;
1400		/*
1401		 * It is possible for the server to reply with AKA
1402		 * Notification, so we must allow the method to continue and
1403		 * not only accept EAP-Success at this point.
1404		 */
1405		ret->methodState = data->use_result_ind ?
1406			METHOD_DONE : METHOD_MAY_CONT;
1407	} else if (data->state == RESULT_SUCCESS)
1408		ret->methodState = METHOD_CONT;
1409
1410	if (ret->methodState == METHOD_DONE) {
1411		ret->allowNotifications = FALSE;
1412	}
1413
1414	return res;
1415}
1416
1417
1418static Boolean eap_aka_has_reauth_data(struct eap_sm *sm, void *priv)
1419{
1420	struct eap_aka_data *data = priv;
1421	return data->pseudonym || data->reauth_id;
1422}
1423
1424
1425static void eap_aka_deinit_for_reauth(struct eap_sm *sm, void *priv)
1426{
1427	struct eap_aka_data *data = priv;
1428	eap_aka_clear_identities(sm, data, CLEAR_EAP_ID);
1429	data->prev_id = -1;
1430	wpabuf_free(data->id_msgs);
1431	data->id_msgs = NULL;
1432	data->use_result_ind = 0;
1433	data->kdf_negotiation = 0;
1434	eap_aka_clear_keys(data, 1);
1435}
1436
1437
1438static void * eap_aka_init_for_reauth(struct eap_sm *sm, void *priv)
1439{
1440	struct eap_aka_data *data = priv;
1441	data->num_id_req = 0;
1442	data->num_notification = 0;
1443	eap_aka_state(data, CONTINUE);
1444	return priv;
1445}
1446
1447
1448static const u8 * eap_aka_get_identity(struct eap_sm *sm, void *priv,
1449				       size_t *len)
1450{
1451	struct eap_aka_data *data = priv;
1452
1453	if (data->reauth_id) {
1454		*len = data->reauth_id_len;
1455		return data->reauth_id;
1456	}
1457
1458	if (data->pseudonym) {
1459		*len = data->pseudonym_len;
1460		return data->pseudonym;
1461	}
1462
1463	return NULL;
1464}
1465
1466
1467static Boolean eap_aka_isKeyAvailable(struct eap_sm *sm, void *priv)
1468{
1469	struct eap_aka_data *data = priv;
1470	return data->state == SUCCESS;
1471}
1472
1473
1474static u8 * eap_aka_getKey(struct eap_sm *sm, void *priv, size_t *len)
1475{
1476	struct eap_aka_data *data = priv;
1477	u8 *key;
1478
1479	if (data->state != SUCCESS)
1480		return NULL;
1481
1482	key = os_memdup(data->msk, EAP_SIM_KEYING_DATA_LEN);
1483	if (key == NULL)
1484		return NULL;
1485
1486	*len = EAP_SIM_KEYING_DATA_LEN;
1487
1488	return key;
1489}
1490
1491
1492static u8 * eap_aka_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
1493{
1494	struct eap_aka_data *data = priv;
1495	u8 *id;
1496
1497	if (data->state != SUCCESS)
1498		return NULL;
1499
1500	*len = 1 + EAP_AKA_RAND_LEN + EAP_AKA_AUTN_LEN;
1501	id = os_malloc(*len);
1502	if (id == NULL)
1503		return NULL;
1504
1505	id[0] = data->eap_method;
1506	os_memcpy(id + 1, data->rand, EAP_AKA_RAND_LEN);
1507	os_memcpy(id + 1 + EAP_AKA_RAND_LEN, data->autn, EAP_AKA_AUTN_LEN);
1508	wpa_hexdump(MSG_DEBUG, "EAP-AKA: Derived Session-Id", id, *len);
1509
1510	return id;
1511}
1512
1513
1514static u8 * eap_aka_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
1515{
1516	struct eap_aka_data *data = priv;
1517	u8 *key;
1518
1519	if (data->state != SUCCESS)
1520		return NULL;
1521
1522	key = os_memdup(data->emsk, EAP_EMSK_LEN);
1523	if (key == NULL)
1524		return NULL;
1525
1526	*len = EAP_EMSK_LEN;
1527
1528	return key;
1529}
1530
1531static int eap_aka_get_error_code(void *priv)
1532{
1533	struct eap_aka_data *data = priv;
1534
1535	if (!data)
1536		return NO_EAP_METHOD_ERROR;
1537
1538	int current_data_error = data->error_code;
1539
1540	/* Now reset for next transaction */
1541	data->error_code = NO_EAP_METHOD_ERROR;
1542
1543	return current_data_error;
1544}
1545
1546int eap_peer_aka_register(void)
1547{
1548	struct eap_method *eap;
1549
1550	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
1551				    EAP_VENDOR_IETF, EAP_TYPE_AKA, "AKA");
1552	if (eap == NULL)
1553		return -1;
1554
1555	eap->init = eap_aka_init;
1556	eap->deinit = eap_aka_deinit;
1557	eap->process = eap_aka_process;
1558	eap->isKeyAvailable = eap_aka_isKeyAvailable;
1559	eap->getKey = eap_aka_getKey;
1560	eap->getSessionId = eap_aka_get_session_id;
1561	eap->has_reauth_data = eap_aka_has_reauth_data;
1562	eap->deinit_for_reauth = eap_aka_deinit_for_reauth;
1563	eap->init_for_reauth = eap_aka_init_for_reauth;
1564	eap->get_identity = eap_aka_get_identity;
1565	eap->get_emsk = eap_aka_get_emsk;
1566	eap->get_error_code = eap_aka_get_error_code;
1567
1568	return eap_peer_method_register(eap);
1569}
1570
1571
1572#ifdef EAP_AKA_PRIME
1573int eap_peer_aka_prime_register(void)
1574{
1575	struct eap_method *eap;
1576
1577	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
1578				    EAP_VENDOR_IETF, EAP_TYPE_AKA_PRIME,
1579				    "AKA'");
1580	if (eap == NULL)
1581		return -1;
1582
1583	eap->init = eap_aka_prime_init;
1584	eap->deinit = eap_aka_deinit;
1585	eap->process = eap_aka_process;
1586	eap->isKeyAvailable = eap_aka_isKeyAvailable;
1587	eap->getKey = eap_aka_getKey;
1588	eap->getSessionId = eap_aka_get_session_id;
1589	eap->has_reauth_data = eap_aka_has_reauth_data;
1590	eap->deinit_for_reauth = eap_aka_deinit_for_reauth;
1591	eap->init_for_reauth = eap_aka_init_for_reauth;
1592	eap->get_identity = eap_aka_get_identity;
1593	eap->get_emsk = eap_aka_get_emsk;
1594	eap->get_error_code = eap_aka_get_error_code;
1595
1596	return eap_peer_method_register(eap);
1597}
1598#endif /* EAP_AKA_PRIME */
1599