xref: /freebsd/contrib/wpa/src/eap_peer/eap_aka.c (revision 0957b409)
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 
22 struct 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
64 static 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 
82 static 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 
91 static 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
126 static 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 
137 static 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 
152 static 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 
167 static 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 
185 static 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 
243 invalid:
244 	wpa_printf(MSG_DEBUG, "EAP-AKA: Invalid external USIM processing UMTS-AUTH response");
245 	os_free(resp);
246 	return -1;
247 }
248 
249 
250 static 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 
353 static 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 
379 static 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 
443 static 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 
462 static 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 
497 static 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 
547 static 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 
565 static 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 
582 static 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 
610 static 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 
654 static 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 
677 static 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 
720 static 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 
753 static 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 
803 static 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
816 static 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 
833 static 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 
854 static 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 
909 static 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 
1099 static 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 
1133 static 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 
1160 static 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 
1196 static 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 
1319 static 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 
1393 done:
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 
1418 static 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 
1425 static 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 
1438 static 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 
1448 static 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 
1467 static 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 
1474 static 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 
1492 static 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 
1514 static 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 
1531 
1532 static int eap_aka_get_error_code(void *priv)
1533 {
1534 	struct eap_aka_data *data = priv;
1535 	int current_data_error;
1536 
1537 	if (!data)
1538 		return NO_EAP_METHOD_ERROR;
1539 
1540 	current_data_error = data->error_code;
1541 
1542 	/* Now reset for next transaction */
1543 	data->error_code = NO_EAP_METHOD_ERROR;
1544 
1545 	return current_data_error;
1546 }
1547 
1548 
1549 int eap_peer_aka_register(void)
1550 {
1551 	struct eap_method *eap;
1552 
1553 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
1554 				    EAP_VENDOR_IETF, EAP_TYPE_AKA, "AKA");
1555 	if (eap == NULL)
1556 		return -1;
1557 
1558 	eap->init = eap_aka_init;
1559 	eap->deinit = eap_aka_deinit;
1560 	eap->process = eap_aka_process;
1561 	eap->isKeyAvailable = eap_aka_isKeyAvailable;
1562 	eap->getKey = eap_aka_getKey;
1563 	eap->getSessionId = eap_aka_get_session_id;
1564 	eap->has_reauth_data = eap_aka_has_reauth_data;
1565 	eap->deinit_for_reauth = eap_aka_deinit_for_reauth;
1566 	eap->init_for_reauth = eap_aka_init_for_reauth;
1567 	eap->get_identity = eap_aka_get_identity;
1568 	eap->get_emsk = eap_aka_get_emsk;
1569 	eap->get_error_code = eap_aka_get_error_code;
1570 
1571 	return eap_peer_method_register(eap);
1572 }
1573 
1574 
1575 #ifdef EAP_AKA_PRIME
1576 int eap_peer_aka_prime_register(void)
1577 {
1578 	struct eap_method *eap;
1579 
1580 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
1581 				    EAP_VENDOR_IETF, EAP_TYPE_AKA_PRIME,
1582 				    "AKA'");
1583 	if (eap == NULL)
1584 		return -1;
1585 
1586 	eap->init = eap_aka_prime_init;
1587 	eap->deinit = eap_aka_deinit;
1588 	eap->process = eap_aka_process;
1589 	eap->isKeyAvailable = eap_aka_isKeyAvailable;
1590 	eap->getKey = eap_aka_getKey;
1591 	eap->getSessionId = eap_aka_get_session_id;
1592 	eap->has_reauth_data = eap_aka_has_reauth_data;
1593 	eap->deinit_for_reauth = eap_aka_deinit_for_reauth;
1594 	eap->init_for_reauth = eap_aka_init_for_reauth;
1595 	eap->get_identity = eap_aka_get_identity;
1596 	eap->get_emsk = eap_aka_get_emsk;
1597 	eap->get_error_code = eap_aka_get_error_code;
1598 
1599 	return eap_peer_method_register(eap);
1600 }
1601 #endif /* EAP_AKA_PRIME */
1602