xref: /freebsd/contrib/wpa/src/eap_peer/eap_aka.c (revision 1f4bcc459a76b7aa664f3fd557684cd0ba6da352)
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 	u8 eap_method;
52 	u8 *network_name;
53 	size_t network_name_len;
54 	u16 kdf;
55 	int kdf_negotiation;
56 };
57 
58 
59 #ifndef CONFIG_NO_STDOUT_DEBUG
60 static const char * eap_aka_state_txt(int state)
61 {
62 	switch (state) {
63 	case CONTINUE:
64 		return "CONTINUE";
65 	case RESULT_SUCCESS:
66 		return "RESULT_SUCCESS";
67 	case SUCCESS:
68 		return "SUCCESS";
69 	case FAILURE:
70 		return "FAILURE";
71 	default:
72 		return "?";
73 	}
74 }
75 #endif /* CONFIG_NO_STDOUT_DEBUG */
76 
77 
78 static void eap_aka_state(struct eap_aka_data *data, int state)
79 {
80 	wpa_printf(MSG_DEBUG, "EAP-AKA: %s -> %s",
81 		   eap_aka_state_txt(data->state),
82 		   eap_aka_state_txt(state));
83 	data->state = state;
84 }
85 
86 
87 static void * eap_aka_init(struct eap_sm *sm)
88 {
89 	struct eap_aka_data *data;
90 	const char *phase1 = eap_get_config_phase1(sm);
91 	struct eap_peer_config *config = eap_get_config(sm);
92 
93 	data = os_zalloc(sizeof(*data));
94 	if (data == NULL)
95 		return NULL;
96 
97 	data->eap_method = EAP_TYPE_AKA;
98 
99 	eap_aka_state(data, CONTINUE);
100 	data->prev_id = -1;
101 
102 	data->result_ind = phase1 && os_strstr(phase1, "result_ind=1") != NULL;
103 
104 	if (config && config->anonymous_identity) {
105 		data->pseudonym = os_malloc(config->anonymous_identity_len);
106 		if (data->pseudonym) {
107 			os_memcpy(data->pseudonym, config->anonymous_identity,
108 				  config->anonymous_identity_len);
109 			data->pseudonym_len = config->anonymous_identity_len;
110 		}
111 	}
112 
113 	return data;
114 }
115 
116 
117 #ifdef EAP_AKA_PRIME
118 static void * eap_aka_prime_init(struct eap_sm *sm)
119 {
120 	struct eap_aka_data *data = eap_aka_init(sm);
121 	if (data == NULL)
122 		return NULL;
123 	data->eap_method = EAP_TYPE_AKA_PRIME;
124 	return data;
125 }
126 #endif /* EAP_AKA_PRIME */
127 
128 
129 static void eap_aka_clear_keys(struct eap_aka_data *data, int reauth)
130 {
131 	if (!reauth) {
132 		os_memset(data->mk, 0, EAP_SIM_MK_LEN);
133 		os_memset(data->k_aut, 0, EAP_AKA_PRIME_K_AUT_LEN);
134 		os_memset(data->k_encr, 0, EAP_SIM_K_ENCR_LEN);
135 		os_memset(data->k_re, 0, EAP_AKA_PRIME_K_RE_LEN);
136 	}
137 	os_memset(data->msk, 0, EAP_SIM_KEYING_DATA_LEN);
138 	os_memset(data->emsk, 0, EAP_EMSK_LEN);
139 	os_memset(data->autn, 0, EAP_AKA_AUTN_LEN);
140 	os_memset(data->auts, 0, EAP_AKA_AUTS_LEN);
141 }
142 
143 
144 static void eap_aka_deinit(struct eap_sm *sm, void *priv)
145 {
146 	struct eap_aka_data *data = priv;
147 	if (data) {
148 		os_free(data->pseudonym);
149 		os_free(data->reauth_id);
150 		os_free(data->last_eap_identity);
151 		wpabuf_free(data->id_msgs);
152 		os_free(data->network_name);
153 		eap_aka_clear_keys(data, 0);
154 		os_free(data);
155 	}
156 }
157 
158 
159 static int eap_aka_ext_sim_req(struct eap_sm *sm, struct eap_aka_data *data)
160 {
161 	char req[200], *pos, *end;
162 
163 	wpa_printf(MSG_DEBUG, "EAP-AKA: Use external USIM processing");
164 	pos = req;
165 	end = pos + sizeof(req);
166 	pos += os_snprintf(pos, end - pos, "UMTS-AUTH");
167 	pos += os_snprintf(pos, end - pos, ":");
168 	pos += wpa_snprintf_hex(pos, end - pos, data->rand, EAP_AKA_RAND_LEN);
169 	pos += os_snprintf(pos, end - pos, ":");
170 	wpa_snprintf_hex(pos, end - pos, data->autn, EAP_AKA_AUTN_LEN);
171 
172 	eap_sm_request_sim(sm, req);
173 	return 1;
174 }
175 
176 
177 static int eap_aka_ext_sim_result(struct eap_sm *sm, struct eap_aka_data *data,
178 				  struct eap_peer_config *conf)
179 {
180 	char *resp, *pos;
181 
182 	wpa_printf(MSG_DEBUG,
183 		   "EAP-AKA: Use result from external USIM processing");
184 
185 	resp = conf->external_sim_resp;
186 	conf->external_sim_resp = NULL;
187 
188 	if (os_strncmp(resp, "UMTS-AUTS:", 10) == 0) {
189 		pos = resp + 10;
190 		if (hexstr2bin(pos, data->auts, EAP_AKA_AUTS_LEN) < 0)
191 			goto invalid;
192 		wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: AUTS", data->auts,
193 				EAP_AKA_AUTS_LEN);
194 		os_free(resp);
195 		return -2;
196 	}
197 
198 	if (os_strncmp(resp, "UMTS-AUTH:", 10) != 0) {
199 		wpa_printf(MSG_DEBUG, "EAP-AKA: Unrecognized external USIM processing response");
200 		os_free(resp);
201 		return -1;
202 	}
203 
204 	pos = resp + 10;
205 	wpa_hexdump(MSG_DEBUG, "EAP-AKA: RAND", data->rand, EAP_AKA_RAND_LEN);
206 
207 	if (hexstr2bin(pos, data->ik, EAP_AKA_IK_LEN) < 0)
208 		goto invalid;
209 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: IK", data->ik, EAP_AKA_IK_LEN);
210 	pos += EAP_AKA_IK_LEN * 2;
211 	if (*pos != ':')
212 		goto invalid;
213 	pos++;
214 
215 	if (hexstr2bin(pos, data->ck, EAP_AKA_CK_LEN) < 0)
216 		goto invalid;
217 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: CK", data->ck, EAP_AKA_CK_LEN);
218 	pos += EAP_AKA_CK_LEN * 2;
219 	if (*pos != ':')
220 		goto invalid;
221 	pos++;
222 
223 	data->res_len = os_strlen(pos) / 2;
224 	if (data->res_len > EAP_AKA_RES_MAX_LEN) {
225 		data->res_len = 0;
226 		goto invalid;
227 	}
228 	if (hexstr2bin(pos, data->res, data->res_len) < 0)
229 		goto invalid;
230 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: RES", data->res, data->res_len);
231 
232 	os_free(resp);
233 	return 0;
234 
235 invalid:
236 	wpa_printf(MSG_DEBUG, "EAP-AKA: Invalid external USIM processing UMTS-AUTH response");
237 	os_free(resp);
238 	return -1;
239 }
240 
241 
242 static int eap_aka_umts_auth(struct eap_sm *sm, struct eap_aka_data *data)
243 {
244 	struct eap_peer_config *conf;
245 
246 	wpa_printf(MSG_DEBUG, "EAP-AKA: UMTS authentication algorithm");
247 
248 	conf = eap_get_config(sm);
249 	if (conf == NULL)
250 		return -1;
251 
252 	if (sm->external_sim) {
253 		if (conf->external_sim_resp)
254 			return eap_aka_ext_sim_result(sm, data, conf);
255 		else
256 			return eap_aka_ext_sim_req(sm, data);
257 	}
258 
259 	if (conf->pcsc) {
260 		return scard_umts_auth(sm->scard_ctx, data->rand,
261 				       data->autn, data->res, &data->res_len,
262 				       data->ik, data->ck, data->auts);
263 	}
264 
265 #ifdef CONFIG_USIM_SIMULATOR
266 	if (conf->password) {
267 		u8 opc[16], k[16], sqn[6];
268 		const char *pos;
269 		wpa_printf(MSG_DEBUG, "EAP-AKA: Use internal Milenage "
270 			   "implementation for UMTS authentication");
271 		if (conf->password_len < 78) {
272 			wpa_printf(MSG_DEBUG, "EAP-AKA: invalid Milenage "
273 				   "password");
274 			return -1;
275 		}
276 		pos = (const char *) conf->password;
277 		if (hexstr2bin(pos, k, 16))
278 			return -1;
279 		pos += 32;
280 		if (*pos != ':')
281 			return -1;
282 		pos++;
283 
284 		if (hexstr2bin(pos, opc, 16))
285 			return -1;
286 		pos += 32;
287 		if (*pos != ':')
288 			return -1;
289 		pos++;
290 
291 		if (hexstr2bin(pos, sqn, 6))
292 			return -1;
293 
294 		return milenage_check(opc, k, sqn, data->rand, data->autn,
295 				      data->ik, data->ck,
296 				      data->res, &data->res_len, data->auts);
297 	}
298 #endif /* CONFIG_USIM_SIMULATOR */
299 
300 #ifdef CONFIG_USIM_HARDCODED
301 	wpa_printf(MSG_DEBUG, "EAP-AKA: Use hardcoded Kc and SRES values for "
302 		   "testing");
303 
304 	/* These hardcoded Kc and SRES values are used for testing.
305 	 * Could consider making them configurable. */
306 	os_memset(data->res, '2', EAP_AKA_RES_MAX_LEN);
307 	data->res_len = EAP_AKA_RES_MAX_LEN;
308 	os_memset(data->ik, '3', EAP_AKA_IK_LEN);
309 	os_memset(data->ck, '4', EAP_AKA_CK_LEN);
310 	{
311 		u8 autn[EAP_AKA_AUTN_LEN];
312 		os_memset(autn, '1', EAP_AKA_AUTN_LEN);
313 		if (os_memcmp_const(autn, data->autn, EAP_AKA_AUTN_LEN) != 0) {
314 			wpa_printf(MSG_WARNING, "EAP-AKA: AUTN did not match "
315 				   "with expected value");
316 			return -1;
317 		}
318 	}
319 #if 0
320 	{
321 		static int test_resync = 1;
322 		if (test_resync) {
323 			/* Test Resynchronization */
324 			test_resync = 0;
325 			return -2;
326 		}
327 	}
328 #endif
329 	return 0;
330 
331 #else /* CONFIG_USIM_HARDCODED */
332 
333 	wpa_printf(MSG_DEBUG, "EAP-AKA: No UMTS authentication algorithm "
334 		   "enabled");
335 	return -1;
336 
337 #endif /* CONFIG_USIM_HARDCODED */
338 }
339 
340 
341 #define CLEAR_PSEUDONYM	0x01
342 #define CLEAR_REAUTH_ID	0x02
343 #define CLEAR_EAP_ID	0x04
344 
345 static void eap_aka_clear_identities(struct eap_sm *sm,
346 				     struct eap_aka_data *data, int id)
347 {
348 	if ((id & CLEAR_PSEUDONYM) && data->pseudonym) {
349 		wpa_printf(MSG_DEBUG, "EAP-AKA: forgetting old pseudonym");
350 		os_free(data->pseudonym);
351 		data->pseudonym = NULL;
352 		data->pseudonym_len = 0;
353 		eap_set_anon_id(sm, NULL, 0);
354 	}
355 	if ((id & CLEAR_REAUTH_ID) && data->reauth_id) {
356 		wpa_printf(MSG_DEBUG, "EAP-AKA: forgetting old reauth_id");
357 		os_free(data->reauth_id);
358 		data->reauth_id = NULL;
359 		data->reauth_id_len = 0;
360 	}
361 	if ((id & CLEAR_EAP_ID) && data->last_eap_identity) {
362 		wpa_printf(MSG_DEBUG, "EAP-AKA: forgetting old eap_id");
363 		os_free(data->last_eap_identity);
364 		data->last_eap_identity = NULL;
365 		data->last_eap_identity_len = 0;
366 	}
367 }
368 
369 
370 static int eap_aka_learn_ids(struct eap_sm *sm, struct eap_aka_data *data,
371 			     struct eap_sim_attrs *attr)
372 {
373 	if (attr->next_pseudonym) {
374 		const u8 *identity = NULL;
375 		size_t identity_len = 0;
376 		const u8 *realm = NULL;
377 		size_t realm_len = 0;
378 
379 		wpa_hexdump_ascii(MSG_DEBUG,
380 				  "EAP-AKA: (encr) AT_NEXT_PSEUDONYM",
381 				  attr->next_pseudonym,
382 				  attr->next_pseudonym_len);
383 		os_free(data->pseudonym);
384 		/* Look for the realm of the permanent identity */
385 		identity = eap_get_config_identity(sm, &identity_len);
386 		if (identity) {
387 			for (realm = identity, realm_len = identity_len;
388 			     realm_len > 0; realm_len--, realm++) {
389 				if (*realm == '@')
390 					break;
391 			}
392 		}
393 		data->pseudonym = os_malloc(attr->next_pseudonym_len +
394 					    realm_len);
395 		if (data->pseudonym == NULL) {
396 			wpa_printf(MSG_INFO, "EAP-AKA: (encr) No memory for "
397 				   "next pseudonym");
398 			data->pseudonym_len = 0;
399 			return -1;
400 		}
401 		os_memcpy(data->pseudonym, attr->next_pseudonym,
402 			  attr->next_pseudonym_len);
403 		if (realm_len) {
404 			os_memcpy(data->pseudonym + attr->next_pseudonym_len,
405 				  realm, realm_len);
406 		}
407 		data->pseudonym_len = attr->next_pseudonym_len + realm_len;
408 		eap_set_anon_id(sm, data->pseudonym, data->pseudonym_len);
409 	}
410 
411 	if (attr->next_reauth_id) {
412 		os_free(data->reauth_id);
413 		data->reauth_id = os_malloc(attr->next_reauth_id_len);
414 		if (data->reauth_id == NULL) {
415 			wpa_printf(MSG_INFO, "EAP-AKA: (encr) No memory for "
416 				   "next reauth_id");
417 			data->reauth_id_len = 0;
418 			return -1;
419 		}
420 		os_memcpy(data->reauth_id, attr->next_reauth_id,
421 			  attr->next_reauth_id_len);
422 		data->reauth_id_len = attr->next_reauth_id_len;
423 		wpa_hexdump_ascii(MSG_DEBUG,
424 				  "EAP-AKA: (encr) AT_NEXT_REAUTH_ID",
425 				  data->reauth_id,
426 				  data->reauth_id_len);
427 	}
428 
429 	return 0;
430 }
431 
432 
433 static int eap_aka_add_id_msg(struct eap_aka_data *data,
434 			      const struct wpabuf *msg)
435 {
436 	if (msg == NULL)
437 		return -1;
438 
439 	if (data->id_msgs == NULL) {
440 		data->id_msgs = wpabuf_dup(msg);
441 		return data->id_msgs == NULL ? -1 : 0;
442 	}
443 
444 	if (wpabuf_resize(&data->id_msgs, wpabuf_len(msg)) < 0)
445 		return -1;
446 	wpabuf_put_buf(data->id_msgs, msg);
447 
448 	return 0;
449 }
450 
451 
452 static void eap_aka_add_checkcode(struct eap_aka_data *data,
453 				  struct eap_sim_msg *msg)
454 {
455 	const u8 *addr;
456 	size_t len;
457 	u8 hash[SHA256_MAC_LEN];
458 
459 	wpa_printf(MSG_DEBUG, "   AT_CHECKCODE");
460 
461 	if (data->id_msgs == NULL) {
462 		/*
463 		 * No EAP-AKA/Identity packets were exchanged - send empty
464 		 * checkcode.
465 		 */
466 		eap_sim_msg_add(msg, EAP_SIM_AT_CHECKCODE, 0, NULL, 0);
467 		return;
468 	}
469 
470 	/* Checkcode is SHA1/SHA256 hash over all EAP-AKA/Identity packets. */
471 	addr = wpabuf_head(data->id_msgs);
472 	len = wpabuf_len(data->id_msgs);
473 	wpa_hexdump(MSG_MSGDUMP, "EAP-AKA: AT_CHECKCODE data", addr, len);
474 #ifdef EAP_AKA_PRIME
475 	if (data->eap_method == EAP_TYPE_AKA_PRIME)
476 		sha256_vector(1, &addr, &len, hash);
477 	else
478 #endif /* EAP_AKA_PRIME */
479 		sha1_vector(1, &addr, &len, hash);
480 
481 	eap_sim_msg_add(msg, EAP_SIM_AT_CHECKCODE, 0, hash,
482 			data->eap_method == EAP_TYPE_AKA_PRIME ?
483 			EAP_AKA_PRIME_CHECKCODE_LEN : EAP_AKA_CHECKCODE_LEN);
484 }
485 
486 
487 static int eap_aka_verify_checkcode(struct eap_aka_data *data,
488 				    const u8 *checkcode, size_t checkcode_len)
489 {
490 	const u8 *addr;
491 	size_t len;
492 	u8 hash[SHA256_MAC_LEN];
493 	size_t hash_len;
494 
495 	if (checkcode == NULL)
496 		return -1;
497 
498 	if (data->id_msgs == NULL) {
499 		if (checkcode_len != 0) {
500 			wpa_printf(MSG_DEBUG, "EAP-AKA: Checkcode from server "
501 				   "indicates that AKA/Identity messages were "
502 				   "used, but they were not");
503 			return -1;
504 		}
505 		return 0;
506 	}
507 
508 	hash_len = data->eap_method == EAP_TYPE_AKA_PRIME ?
509 		EAP_AKA_PRIME_CHECKCODE_LEN : EAP_AKA_CHECKCODE_LEN;
510 
511 	if (checkcode_len != hash_len) {
512 		wpa_printf(MSG_DEBUG, "EAP-AKA: Checkcode from server "
513 			   "indicates that AKA/Identity message were not "
514 			   "used, but they were");
515 		return -1;
516 	}
517 
518 	/* Checkcode is SHA1/SHA256 hash over all EAP-AKA/Identity packets. */
519 	addr = wpabuf_head(data->id_msgs);
520 	len = wpabuf_len(data->id_msgs);
521 #ifdef EAP_AKA_PRIME
522 	if (data->eap_method == EAP_TYPE_AKA_PRIME)
523 		sha256_vector(1, &addr, &len, hash);
524 	else
525 #endif /* EAP_AKA_PRIME */
526 		sha1_vector(1, &addr, &len, hash);
527 
528 	if (os_memcmp_const(hash, checkcode, hash_len) != 0) {
529 		wpa_printf(MSG_DEBUG, "EAP-AKA: Mismatch in AT_CHECKCODE");
530 		return -1;
531 	}
532 
533 	return 0;
534 }
535 
536 
537 static struct wpabuf * eap_aka_client_error(struct eap_aka_data *data, u8 id,
538 					    int err)
539 {
540 	struct eap_sim_msg *msg;
541 
542 	eap_aka_state(data, FAILURE);
543 	data->num_id_req = 0;
544 	data->num_notification = 0;
545 
546 	wpa_printf(MSG_DEBUG, "EAP-AKA: Send Client-Error (error code %d)",
547 		   err);
548 	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
549 			       EAP_AKA_SUBTYPE_CLIENT_ERROR);
550 	eap_sim_msg_add(msg, EAP_SIM_AT_CLIENT_ERROR_CODE, err, NULL, 0);
551 	return eap_sim_msg_finish(msg, data->eap_method, NULL, NULL, 0);
552 }
553 
554 
555 static struct wpabuf * eap_aka_authentication_reject(struct eap_aka_data *data,
556 						     u8 id)
557 {
558 	struct eap_sim_msg *msg;
559 
560 	eap_aka_state(data, FAILURE);
561 	data->num_id_req = 0;
562 	data->num_notification = 0;
563 
564 	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Authentication-Reject "
565 		   "(id=%d)", id);
566 	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
567 			       EAP_AKA_SUBTYPE_AUTHENTICATION_REJECT);
568 	return eap_sim_msg_finish(msg, data->eap_method, NULL, NULL, 0);
569 }
570 
571 
572 static struct wpabuf * eap_aka_synchronization_failure(
573 	struct eap_aka_data *data, u8 id)
574 {
575 	struct eap_sim_msg *msg;
576 
577 	data->num_id_req = 0;
578 	data->num_notification = 0;
579 
580 	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Synchronization-Failure "
581 		   "(id=%d)", id);
582 	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
583 			       EAP_AKA_SUBTYPE_SYNCHRONIZATION_FAILURE);
584 	wpa_printf(MSG_DEBUG, "   AT_AUTS");
585 	eap_sim_msg_add_full(msg, EAP_SIM_AT_AUTS, data->auts,
586 			     EAP_AKA_AUTS_LEN);
587 	return eap_sim_msg_finish(msg, data->eap_method, NULL, NULL, 0);
588 }
589 
590 
591 static struct wpabuf * eap_aka_response_identity(struct eap_sm *sm,
592 						 struct eap_aka_data *data,
593 						 u8 id,
594 						 enum eap_sim_id_req id_req)
595 {
596 	const u8 *identity = NULL;
597 	size_t identity_len = 0;
598 	struct eap_sim_msg *msg;
599 
600 	data->reauth = 0;
601 	if (id_req == ANY_ID && data->reauth_id) {
602 		identity = data->reauth_id;
603 		identity_len = data->reauth_id_len;
604 		data->reauth = 1;
605 	} else if ((id_req == ANY_ID || id_req == FULLAUTH_ID) &&
606 		   data->pseudonym) {
607 		identity = data->pseudonym;
608 		identity_len = data->pseudonym_len;
609 		eap_aka_clear_identities(sm, data, CLEAR_REAUTH_ID);
610 	} else if (id_req != NO_ID_REQ) {
611 		identity = eap_get_config_identity(sm, &identity_len);
612 		if (identity) {
613 			eap_aka_clear_identities(sm, data, CLEAR_PSEUDONYM |
614 						 CLEAR_REAUTH_ID);
615 		}
616 	}
617 	if (id_req != NO_ID_REQ)
618 		eap_aka_clear_identities(sm, data, CLEAR_EAP_ID);
619 
620 	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Identity (id=%d)", id);
621 	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
622 			       EAP_AKA_SUBTYPE_IDENTITY);
623 
624 	if (identity) {
625 		wpa_hexdump_ascii(MSG_DEBUG, "   AT_IDENTITY",
626 				  identity, identity_len);
627 		eap_sim_msg_add(msg, EAP_SIM_AT_IDENTITY, identity_len,
628 				identity, identity_len);
629 	}
630 
631 	return eap_sim_msg_finish(msg, data->eap_method, NULL, NULL, 0);
632 }
633 
634 
635 static struct wpabuf * eap_aka_response_challenge(struct eap_aka_data *data,
636 						  u8 id)
637 {
638 	struct eap_sim_msg *msg;
639 
640 	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Challenge (id=%d)", id);
641 	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
642 			       EAP_AKA_SUBTYPE_CHALLENGE);
643 	wpa_printf(MSG_DEBUG, "   AT_RES");
644 	eap_sim_msg_add(msg, EAP_SIM_AT_RES, data->res_len * 8,
645 			data->res, data->res_len);
646 	eap_aka_add_checkcode(data, msg);
647 	if (data->use_result_ind) {
648 		wpa_printf(MSG_DEBUG, "   AT_RESULT_IND");
649 		eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
650 	}
651 	wpa_printf(MSG_DEBUG, "   AT_MAC");
652 	eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
653 	return eap_sim_msg_finish(msg, data->eap_method, data->k_aut, (u8 *) "",
654 				  0);
655 }
656 
657 
658 static struct wpabuf * eap_aka_response_reauth(struct eap_aka_data *data,
659 					       u8 id, int counter_too_small,
660 					       const u8 *nonce_s)
661 {
662 	struct eap_sim_msg *msg;
663 	unsigned int counter;
664 
665 	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Reauthentication (id=%d)",
666 		   id);
667 	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
668 			       EAP_AKA_SUBTYPE_REAUTHENTICATION);
669 	wpa_printf(MSG_DEBUG, "   AT_IV");
670 	wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
671 	eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA);
672 
673 	if (counter_too_small) {
674 		wpa_printf(MSG_DEBUG, "   *AT_COUNTER_TOO_SMALL");
675 		eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER_TOO_SMALL, 0, NULL, 0);
676 		counter = data->counter_too_small;
677 	} else
678 		counter = data->counter;
679 
680 	wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", counter);
681 	eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0);
682 
683 	if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) {
684 		wpa_printf(MSG_WARNING, "EAP-AKA: Failed to encrypt "
685 			   "AT_ENCR_DATA");
686 		eap_sim_msg_free(msg);
687 		return NULL;
688 	}
689 	eap_aka_add_checkcode(data, msg);
690 	if (data->use_result_ind) {
691 		wpa_printf(MSG_DEBUG, "   AT_RESULT_IND");
692 		eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
693 	}
694 	wpa_printf(MSG_DEBUG, "   AT_MAC");
695 	eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
696 	return eap_sim_msg_finish(msg, data->eap_method, data->k_aut, nonce_s,
697 				  EAP_SIM_NONCE_S_LEN);
698 }
699 
700 
701 static struct wpabuf * eap_aka_response_notification(struct eap_aka_data *data,
702 						     u8 id, u16 notification)
703 {
704 	struct eap_sim_msg *msg;
705 	u8 *k_aut = (notification & 0x4000) == 0 ? data->k_aut : NULL;
706 
707 	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Notification (id=%d)", id);
708 	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
709 			       EAP_AKA_SUBTYPE_NOTIFICATION);
710 	if (k_aut && data->reauth) {
711 		wpa_printf(MSG_DEBUG, "   AT_IV");
712 		wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
713 		eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
714 					   EAP_SIM_AT_ENCR_DATA);
715 		wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", data->counter);
716 		eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
717 				NULL, 0);
718 		if (eap_sim_msg_add_encr_end(msg, data->k_encr,
719 					     EAP_SIM_AT_PADDING)) {
720 			wpa_printf(MSG_WARNING, "EAP-AKA: Failed to encrypt "
721 				   "AT_ENCR_DATA");
722 			eap_sim_msg_free(msg);
723 			return NULL;
724 		}
725 	}
726 	if (k_aut) {
727 		wpa_printf(MSG_DEBUG, "   AT_MAC");
728 		eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
729 	}
730 	return eap_sim_msg_finish(msg, data->eap_method, k_aut, (u8 *) "", 0);
731 }
732 
733 
734 static struct wpabuf * eap_aka_process_identity(struct eap_sm *sm,
735 						struct eap_aka_data *data,
736 						u8 id,
737 						const struct wpabuf *reqData,
738 						struct eap_sim_attrs *attr)
739 {
740 	int id_error;
741 	struct wpabuf *buf;
742 
743 	wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Identity");
744 
745 	id_error = 0;
746 	switch (attr->id_req) {
747 	case NO_ID_REQ:
748 		break;
749 	case ANY_ID:
750 		if (data->num_id_req > 0)
751 			id_error++;
752 		data->num_id_req++;
753 		break;
754 	case FULLAUTH_ID:
755 		if (data->num_id_req > 1)
756 			id_error++;
757 		data->num_id_req++;
758 		break;
759 	case PERMANENT_ID:
760 		if (data->num_id_req > 2)
761 			id_error++;
762 		data->num_id_req++;
763 		break;
764 	}
765 	if (id_error) {
766 		wpa_printf(MSG_INFO, "EAP-AKA: Too many ID requests "
767 			   "used within one authentication");
768 		return eap_aka_client_error(data, id,
769 					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
770 	}
771 
772 	buf = eap_aka_response_identity(sm, data, id, attr->id_req);
773 
774 	if (data->prev_id != id) {
775 		eap_aka_add_id_msg(data, reqData);
776 		eap_aka_add_id_msg(data, buf);
777 		data->prev_id = id;
778 	}
779 
780 	return buf;
781 }
782 
783 
784 static int eap_aka_verify_mac(struct eap_aka_data *data,
785 			      const struct wpabuf *req,
786 			      const u8 *mac, const u8 *extra,
787 			      size_t extra_len)
788 {
789 	if (data->eap_method == EAP_TYPE_AKA_PRIME)
790 		return eap_sim_verify_mac_sha256(data->k_aut, req, mac, extra,
791 						 extra_len);
792 	return eap_sim_verify_mac(data->k_aut, req, mac, extra, extra_len);
793 }
794 
795 
796 #ifdef EAP_AKA_PRIME
797 static struct wpabuf * eap_aka_prime_kdf_select(struct eap_aka_data *data,
798 						u8 id, u16 kdf)
799 {
800 	struct eap_sim_msg *msg;
801 
802 	data->kdf_negotiation = 1;
803 	data->kdf = kdf;
804 	wpa_printf(MSG_DEBUG, "Generating EAP-AKA Challenge (id=%d) (KDF "
805 		   "select)", id);
806 	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, data->eap_method,
807 			       EAP_AKA_SUBTYPE_CHALLENGE);
808 	wpa_printf(MSG_DEBUG, "   AT_KDF");
809 	eap_sim_msg_add(msg, EAP_SIM_AT_KDF, kdf, NULL, 0);
810 	return eap_sim_msg_finish(msg, data->eap_method, NULL, NULL, 0);
811 }
812 
813 
814 static struct wpabuf * eap_aka_prime_kdf_neg(struct eap_aka_data *data,
815 					     u8 id, struct eap_sim_attrs *attr)
816 {
817 	size_t i;
818 
819 	for (i = 0; i < attr->kdf_count; i++) {
820 		if (attr->kdf[i] == EAP_AKA_PRIME_KDF)
821 			return eap_aka_prime_kdf_select(data, id,
822 							EAP_AKA_PRIME_KDF);
823 	}
824 
825 	/* No matching KDF found - fail authentication as if AUTN had been
826 	 * incorrect */
827 	return eap_aka_authentication_reject(data, id);
828 }
829 
830 
831 static int eap_aka_prime_kdf_valid(struct eap_aka_data *data,
832 				   struct eap_sim_attrs *attr)
833 {
834 	size_t i, j;
835 
836 	if (attr->kdf_count == 0)
837 		return 0;
838 
839 	/* The only allowed (and required) duplication of a KDF is the addition
840 	 * of the selected KDF into the beginning of the list. */
841 
842 	if (data->kdf_negotiation) {
843 		if (attr->kdf[0] != data->kdf) {
844 			wpa_printf(MSG_WARNING, "EAP-AKA': The server did not "
845 				   "accept the selected KDF");
846 			return 0;
847 		}
848 
849 		for (i = 1; i < attr->kdf_count; i++) {
850 			if (attr->kdf[i] == data->kdf)
851 				break;
852 		}
853 		if (i == attr->kdf_count &&
854 		    attr->kdf_count < EAP_AKA_PRIME_KDF_MAX) {
855 			wpa_printf(MSG_WARNING, "EAP-AKA': The server did not "
856 				   "duplicate the selected KDF");
857 			return 0;
858 		}
859 
860 		/* TODO: should check that the list is identical to the one
861 		 * used in the previous Challenge message apart from the added
862 		 * entry in the beginning. */
863 	}
864 
865 	for (i = data->kdf ? 1 : 0; i < attr->kdf_count; i++) {
866 		for (j = i + 1; j < attr->kdf_count; j++) {
867 			if (attr->kdf[i] == attr->kdf[j]) {
868 				wpa_printf(MSG_WARNING, "EAP-AKA': The server "
869 					   "included a duplicated KDF");
870 				return 0;
871 			}
872 		}
873 	}
874 
875 	return 1;
876 }
877 #endif /* EAP_AKA_PRIME */
878 
879 
880 static struct wpabuf * eap_aka_process_challenge(struct eap_sm *sm,
881 						 struct eap_aka_data *data,
882 						 u8 id,
883 						 const struct wpabuf *reqData,
884 						 struct eap_sim_attrs *attr)
885 {
886 	const u8 *identity;
887 	size_t identity_len;
888 	int res;
889 	struct eap_sim_attrs eattr;
890 
891 	wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Challenge");
892 
893 	if (attr->checkcode &&
894 	    eap_aka_verify_checkcode(data, attr->checkcode,
895 				     attr->checkcode_len)) {
896 		wpa_printf(MSG_WARNING, "EAP-AKA: Invalid AT_CHECKCODE in the "
897 			   "message");
898 		return eap_aka_client_error(data, id,
899 					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
900 	}
901 
902 #ifdef EAP_AKA_PRIME
903 	if (data->eap_method == EAP_TYPE_AKA_PRIME) {
904 		if (!attr->kdf_input || attr->kdf_input_len == 0) {
905 			wpa_printf(MSG_WARNING, "EAP-AKA': Challenge message "
906 				   "did not include non-empty AT_KDF_INPUT");
907 			/* Fail authentication as if AUTN had been incorrect */
908 			return eap_aka_authentication_reject(data, id);
909 		}
910 		os_free(data->network_name);
911 		data->network_name = os_malloc(attr->kdf_input_len);
912 		if (data->network_name == NULL) {
913 			wpa_printf(MSG_WARNING, "EAP-AKA': No memory for "
914 				   "storing Network Name");
915 			return eap_aka_authentication_reject(data, id);
916 		}
917 		os_memcpy(data->network_name, attr->kdf_input,
918 			  attr->kdf_input_len);
919 		data->network_name_len = attr->kdf_input_len;
920 		wpa_hexdump_ascii(MSG_DEBUG, "EAP-AKA': Network Name "
921 				  "(AT_KDF_INPUT)",
922 				  data->network_name, data->network_name_len);
923 		/* TODO: check Network Name per 3GPP.33.402 */
924 
925 		if (!eap_aka_prime_kdf_valid(data, attr))
926 			return eap_aka_authentication_reject(data, id);
927 
928 		if (attr->kdf[0] != EAP_AKA_PRIME_KDF)
929 			return eap_aka_prime_kdf_neg(data, id, attr);
930 
931 		data->kdf = EAP_AKA_PRIME_KDF;
932 		wpa_printf(MSG_DEBUG, "EAP-AKA': KDF %d selected", data->kdf);
933 	}
934 
935 	if (data->eap_method == EAP_TYPE_AKA && attr->bidding) {
936 		u16 flags = WPA_GET_BE16(attr->bidding);
937 		if ((flags & EAP_AKA_BIDDING_FLAG_D) &&
938 		    eap_allowed_method(sm, EAP_VENDOR_IETF,
939 				       EAP_TYPE_AKA_PRIME)) {
940 			wpa_printf(MSG_WARNING, "EAP-AKA: Bidding down from "
941 				   "AKA' to AKA detected");
942 			/* Fail authentication as if AUTN had been incorrect */
943 			return eap_aka_authentication_reject(data, id);
944 		}
945 	}
946 #endif /* EAP_AKA_PRIME */
947 
948 	data->reauth = 0;
949 	if (!attr->mac || !attr->rand || !attr->autn) {
950 		wpa_printf(MSG_WARNING, "EAP-AKA: Challenge message "
951 			   "did not include%s%s%s",
952 			   !attr->mac ? " AT_MAC" : "",
953 			   !attr->rand ? " AT_RAND" : "",
954 			   !attr->autn ? " AT_AUTN" : "");
955 		return eap_aka_client_error(data, id,
956 					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
957 	}
958 	os_memcpy(data->rand, attr->rand, EAP_AKA_RAND_LEN);
959 	os_memcpy(data->autn, attr->autn, EAP_AKA_AUTN_LEN);
960 
961 	res = eap_aka_umts_auth(sm, data);
962 	if (res == -1) {
963 		wpa_printf(MSG_WARNING, "EAP-AKA: UMTS authentication "
964 			   "failed (AUTN)");
965 		return eap_aka_authentication_reject(data, id);
966 	} else if (res == -2) {
967 		wpa_printf(MSG_WARNING, "EAP-AKA: UMTS authentication "
968 			   "failed (AUTN seq# -> AUTS)");
969 		return eap_aka_synchronization_failure(data, id);
970 	} else if (res > 0) {
971 		wpa_printf(MSG_DEBUG, "EAP-AKA: Wait for external USIM processing");
972 		return NULL;
973 	} else if (res) {
974 		wpa_printf(MSG_WARNING, "EAP-AKA: UMTS authentication failed");
975 		return eap_aka_client_error(data, id,
976 					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
977 	}
978 #ifdef EAP_AKA_PRIME
979 	if (data->eap_method == EAP_TYPE_AKA_PRIME) {
980 		/* Note: AUTN = (SQN ^ AK) || AMF || MAC which gives us the
981 		 * needed 6-octet SQN ^ AK for CK',IK' derivation */
982 		u16 amf = WPA_GET_BE16(data->autn + 6);
983 		if (!(amf & 0x8000)) {
984 			wpa_printf(MSG_WARNING, "EAP-AKA': AMF separation bit "
985 				   "not set (AMF=0x%4x)", amf);
986 			return eap_aka_authentication_reject(data, id);
987 		}
988 		eap_aka_prime_derive_ck_ik_prime(data->ck, data->ik,
989 						 data->autn,
990 						 data->network_name,
991 						 data->network_name_len);
992 	}
993 #endif /* EAP_AKA_PRIME */
994 	if (data->last_eap_identity) {
995 		identity = data->last_eap_identity;
996 		identity_len = data->last_eap_identity_len;
997 	} else if (data->pseudonym) {
998 		identity = data->pseudonym;
999 		identity_len = data->pseudonym_len;
1000 	} else
1001 		identity = eap_get_config_identity(sm, &identity_len);
1002 	wpa_hexdump_ascii(MSG_DEBUG, "EAP-AKA: Selected identity for MK "
1003 			  "derivation", identity, identity_len);
1004 	if (data->eap_method == EAP_TYPE_AKA_PRIME) {
1005 		eap_aka_prime_derive_keys(identity, identity_len, data->ik,
1006 					  data->ck, data->k_encr, data->k_aut,
1007 					  data->k_re, data->msk, data->emsk);
1008 	} else {
1009 		eap_aka_derive_mk(identity, identity_len, data->ik, data->ck,
1010 				  data->mk);
1011 		eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut,
1012 				    data->msk, data->emsk);
1013 	}
1014 	if (eap_aka_verify_mac(data, reqData, attr->mac, (u8 *) "", 0)) {
1015 		wpa_printf(MSG_WARNING, "EAP-AKA: Challenge message "
1016 			   "used invalid AT_MAC");
1017 		return eap_aka_client_error(data, id,
1018 					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1019 	}
1020 
1021 	/* Old reauthentication identity must not be used anymore. In
1022 	 * other words, if no new identities are received, full
1023 	 * authentication will be used on next reauthentication (using
1024 	 * pseudonym identity or permanent identity). */
1025 	eap_aka_clear_identities(sm, data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
1026 
1027 	if (attr->encr_data) {
1028 		u8 *decrypted;
1029 		decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
1030 					       attr->encr_data_len, attr->iv,
1031 					       &eattr, 0);
1032 		if (decrypted == NULL) {
1033 			return eap_aka_client_error(
1034 				data, id, EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1035 		}
1036 		eap_aka_learn_ids(sm, data, &eattr);
1037 		os_free(decrypted);
1038 	}
1039 
1040 	if (data->result_ind && attr->result_ind)
1041 		data->use_result_ind = 1;
1042 
1043 	if (data->state != FAILURE) {
1044 		eap_aka_state(data, data->use_result_ind ?
1045 			      RESULT_SUCCESS : SUCCESS);
1046 	}
1047 
1048 	data->num_id_req = 0;
1049 	data->num_notification = 0;
1050 	/* RFC 4187 specifies that counter is initialized to one after
1051 	 * fullauth, but initializing it to zero makes it easier to implement
1052 	 * reauth verification. */
1053 	data->counter = 0;
1054 	return eap_aka_response_challenge(data, id);
1055 }
1056 
1057 
1058 static int eap_aka_process_notification_reauth(struct eap_aka_data *data,
1059 					       struct eap_sim_attrs *attr)
1060 {
1061 	struct eap_sim_attrs eattr;
1062 	u8 *decrypted;
1063 
1064 	if (attr->encr_data == NULL || attr->iv == NULL) {
1065 		wpa_printf(MSG_WARNING, "EAP-AKA: Notification message after "
1066 			   "reauth did not include encrypted data");
1067 		return -1;
1068 	}
1069 
1070 	decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
1071 				       attr->encr_data_len, attr->iv, &eattr,
1072 				       0);
1073 	if (decrypted == NULL) {
1074 		wpa_printf(MSG_WARNING, "EAP-AKA: Failed to parse encrypted "
1075 			   "data from notification message");
1076 		return -1;
1077 	}
1078 
1079 	if (eattr.counter < 0 || (size_t) eattr.counter != data->counter) {
1080 		wpa_printf(MSG_WARNING, "EAP-AKA: Counter in notification "
1081 			   "message does not match with counter in reauth "
1082 			   "message");
1083 		os_free(decrypted);
1084 		return -1;
1085 	}
1086 
1087 	os_free(decrypted);
1088 	return 0;
1089 }
1090 
1091 
1092 static int eap_aka_process_notification_auth(struct eap_aka_data *data,
1093 					     const struct wpabuf *reqData,
1094 					     struct eap_sim_attrs *attr)
1095 {
1096 	if (attr->mac == NULL) {
1097 		wpa_printf(MSG_INFO, "EAP-AKA: no AT_MAC in after_auth "
1098 			   "Notification message");
1099 		return -1;
1100 	}
1101 
1102 	if (eap_aka_verify_mac(data, reqData, attr->mac, (u8 *) "", 0)) {
1103 		wpa_printf(MSG_WARNING, "EAP-AKA: Notification message "
1104 			   "used invalid AT_MAC");
1105 		return -1;
1106 	}
1107 
1108 	if (data->reauth &&
1109 	    eap_aka_process_notification_reauth(data, attr)) {
1110 		wpa_printf(MSG_WARNING, "EAP-AKA: Invalid notification "
1111 			   "message after reauth");
1112 		return -1;
1113 	}
1114 
1115 	return 0;
1116 }
1117 
1118 
1119 static struct wpabuf * eap_aka_process_notification(
1120 	struct eap_sm *sm, struct eap_aka_data *data, u8 id,
1121 	const struct wpabuf *reqData, struct eap_sim_attrs *attr)
1122 {
1123 	wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Notification");
1124 	if (data->num_notification > 0) {
1125 		wpa_printf(MSG_INFO, "EAP-AKA: too many notification "
1126 			   "rounds (only one allowed)");
1127 		return eap_aka_client_error(data, id,
1128 					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1129 	}
1130 	data->num_notification++;
1131 	if (attr->notification == -1) {
1132 		wpa_printf(MSG_INFO, "EAP-AKA: no AT_NOTIFICATION in "
1133 			   "Notification message");
1134 		return eap_aka_client_error(data, id,
1135 					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1136 	}
1137 
1138 	if ((attr->notification & 0x4000) == 0 &&
1139 	    eap_aka_process_notification_auth(data, reqData, attr)) {
1140 		return eap_aka_client_error(data, id,
1141 					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1142 	}
1143 
1144 	eap_sim_report_notification(sm->msg_ctx, attr->notification, 1);
1145 	if (attr->notification >= 0 && attr->notification < 32768) {
1146 		eap_aka_state(data, FAILURE);
1147 	} else if (attr->notification == EAP_SIM_SUCCESS &&
1148 		   data->state == RESULT_SUCCESS)
1149 		eap_aka_state(data, SUCCESS);
1150 	return eap_aka_response_notification(data, id, attr->notification);
1151 }
1152 
1153 
1154 static struct wpabuf * eap_aka_process_reauthentication(
1155 	struct eap_sm *sm, struct eap_aka_data *data, u8 id,
1156 	const struct wpabuf *reqData, struct eap_sim_attrs *attr)
1157 {
1158 	struct eap_sim_attrs eattr;
1159 	u8 *decrypted;
1160 
1161 	wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Reauthentication");
1162 
1163 	if (attr->checkcode &&
1164 	    eap_aka_verify_checkcode(data, attr->checkcode,
1165 				     attr->checkcode_len)) {
1166 		wpa_printf(MSG_WARNING, "EAP-AKA: Invalid AT_CHECKCODE in the "
1167 			   "message");
1168 		return eap_aka_client_error(data, id,
1169 					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1170 	}
1171 
1172 	if (data->reauth_id == NULL) {
1173 		wpa_printf(MSG_WARNING, "EAP-AKA: Server is trying "
1174 			   "reauthentication, but no reauth_id available");
1175 		return eap_aka_client_error(data, id,
1176 					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1177 	}
1178 
1179 	data->reauth = 1;
1180 	if (eap_aka_verify_mac(data, reqData, attr->mac, (u8 *) "", 0)) {
1181 		wpa_printf(MSG_WARNING, "EAP-AKA: Reauthentication "
1182 			   "did not have valid AT_MAC");
1183 		return eap_aka_client_error(data, id,
1184 					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1185 	}
1186 
1187 	if (attr->encr_data == NULL || attr->iv == NULL) {
1188 		wpa_printf(MSG_WARNING, "EAP-AKA: Reauthentication "
1189 			   "message did not include encrypted data");
1190 		return eap_aka_client_error(data, id,
1191 					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1192 	}
1193 
1194 	decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
1195 				       attr->encr_data_len, attr->iv, &eattr,
1196 				       0);
1197 	if (decrypted == NULL) {
1198 		wpa_printf(MSG_WARNING, "EAP-AKA: Failed to parse encrypted "
1199 			   "data from reauthentication message");
1200 		return eap_aka_client_error(data, id,
1201 					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1202 	}
1203 
1204 	if (eattr.nonce_s == NULL || eattr.counter < 0) {
1205 		wpa_printf(MSG_INFO, "EAP-AKA: (encr) No%s%s in reauth packet",
1206 			   !eattr.nonce_s ? " AT_NONCE_S" : "",
1207 			   eattr.counter < 0 ? " AT_COUNTER" : "");
1208 		os_free(decrypted);
1209 		return eap_aka_client_error(data, id,
1210 					    EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1211 	}
1212 
1213 	if (eattr.counter < 0 || (size_t) eattr.counter <= data->counter) {
1214 		struct wpabuf *res;
1215 		wpa_printf(MSG_INFO, "EAP-AKA: (encr) Invalid counter "
1216 			   "(%d <= %d)", eattr.counter, data->counter);
1217 		data->counter_too_small = eattr.counter;
1218 
1219 		/* Reply using Re-auth w/ AT_COUNTER_TOO_SMALL. The current
1220 		 * reauth_id must not be used to start a new reauthentication.
1221 		 * However, since it was used in the last EAP-Response-Identity
1222 		 * packet, it has to saved for the following fullauth to be
1223 		 * used in MK derivation. */
1224 		os_free(data->last_eap_identity);
1225 		data->last_eap_identity = data->reauth_id;
1226 		data->last_eap_identity_len = data->reauth_id_len;
1227 		data->reauth_id = NULL;
1228 		data->reauth_id_len = 0;
1229 
1230 		res = eap_aka_response_reauth(data, id, 1, eattr.nonce_s);
1231 		os_free(decrypted);
1232 
1233 		return res;
1234 	}
1235 	data->counter = eattr.counter;
1236 
1237 	os_memcpy(data->nonce_s, eattr.nonce_s, EAP_SIM_NONCE_S_LEN);
1238 	wpa_hexdump(MSG_DEBUG, "EAP-AKA: (encr) AT_NONCE_S",
1239 		    data->nonce_s, EAP_SIM_NONCE_S_LEN);
1240 
1241 	if (data->eap_method == EAP_TYPE_AKA_PRIME) {
1242 		eap_aka_prime_derive_keys_reauth(data->k_re, data->counter,
1243 						 data->reauth_id,
1244 						 data->reauth_id_len,
1245 						 data->nonce_s,
1246 						 data->msk, data->emsk);
1247 	} else {
1248 		eap_sim_derive_keys_reauth(data->counter, data->reauth_id,
1249 					   data->reauth_id_len,
1250 					   data->nonce_s, data->mk,
1251 					   data->msk, data->emsk);
1252 	}
1253 	eap_aka_clear_identities(sm, data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
1254 	eap_aka_learn_ids(sm, data, &eattr);
1255 
1256 	if (data->result_ind && attr->result_ind)
1257 		data->use_result_ind = 1;
1258 
1259 	if (data->state != FAILURE) {
1260 		eap_aka_state(data, data->use_result_ind ?
1261 			      RESULT_SUCCESS : SUCCESS);
1262 	}
1263 
1264 	data->num_id_req = 0;
1265 	data->num_notification = 0;
1266 	if (data->counter > EAP_AKA_MAX_FAST_REAUTHS) {
1267 		wpa_printf(MSG_DEBUG, "EAP-AKA: Maximum number of "
1268 			   "fast reauths performed - force fullauth");
1269 		eap_aka_clear_identities(sm, data,
1270 					 CLEAR_REAUTH_ID | CLEAR_EAP_ID);
1271 	}
1272 	os_free(decrypted);
1273 	return eap_aka_response_reauth(data, id, 0, data->nonce_s);
1274 }
1275 
1276 
1277 static struct wpabuf * eap_aka_process(struct eap_sm *sm, void *priv,
1278 				       struct eap_method_ret *ret,
1279 				       const struct wpabuf *reqData)
1280 {
1281 	struct eap_aka_data *data = priv;
1282 	const struct eap_hdr *req;
1283 	u8 subtype, id;
1284 	struct wpabuf *res;
1285 	const u8 *pos;
1286 	struct eap_sim_attrs attr;
1287 	size_t len;
1288 
1289 	wpa_hexdump_buf(MSG_DEBUG, "EAP-AKA: EAP data", reqData);
1290 	if (eap_get_config_identity(sm, &len) == NULL) {
1291 		wpa_printf(MSG_INFO, "EAP-AKA: Identity not configured");
1292 		eap_sm_request_identity(sm);
1293 		ret->ignore = TRUE;
1294 		return NULL;
1295 	}
1296 
1297 	pos = eap_hdr_validate(EAP_VENDOR_IETF, data->eap_method, reqData,
1298 			       &len);
1299 	if (pos == NULL || len < 3) {
1300 		ret->ignore = TRUE;
1301 		return NULL;
1302 	}
1303 	req = wpabuf_head(reqData);
1304 	id = req->identifier;
1305 	len = be_to_host16(req->length);
1306 
1307 	ret->ignore = FALSE;
1308 	ret->methodState = METHOD_MAY_CONT;
1309 	ret->decision = DECISION_FAIL;
1310 	ret->allowNotifications = TRUE;
1311 
1312 	subtype = *pos++;
1313 	wpa_printf(MSG_DEBUG, "EAP-AKA: Subtype=%d", subtype);
1314 	pos += 2; /* Reserved */
1315 
1316 	if (eap_sim_parse_attr(pos, wpabuf_head_u8(reqData) + len, &attr,
1317 			       data->eap_method == EAP_TYPE_AKA_PRIME ? 2 : 1,
1318 			       0)) {
1319 		res = eap_aka_client_error(data, id,
1320 					   EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1321 		goto done;
1322 	}
1323 
1324 	switch (subtype) {
1325 	case EAP_AKA_SUBTYPE_IDENTITY:
1326 		res = eap_aka_process_identity(sm, data, id, reqData, &attr);
1327 		break;
1328 	case EAP_AKA_SUBTYPE_CHALLENGE:
1329 		res = eap_aka_process_challenge(sm, data, id, reqData, &attr);
1330 		break;
1331 	case EAP_AKA_SUBTYPE_NOTIFICATION:
1332 		res = eap_aka_process_notification(sm, data, id, reqData,
1333 						   &attr);
1334 		break;
1335 	case EAP_AKA_SUBTYPE_REAUTHENTICATION:
1336 		res = eap_aka_process_reauthentication(sm, data, id, reqData,
1337 						       &attr);
1338 		break;
1339 	case EAP_AKA_SUBTYPE_CLIENT_ERROR:
1340 		wpa_printf(MSG_DEBUG, "EAP-AKA: subtype Client-Error");
1341 		res = eap_aka_client_error(data, id,
1342 					   EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1343 		break;
1344 	default:
1345 		wpa_printf(MSG_DEBUG, "EAP-AKA: Unknown subtype=%d", subtype);
1346 		res = eap_aka_client_error(data, id,
1347 					   EAP_AKA_UNABLE_TO_PROCESS_PACKET);
1348 		break;
1349 	}
1350 
1351 done:
1352 	if (data->state == FAILURE) {
1353 		ret->decision = DECISION_FAIL;
1354 		ret->methodState = METHOD_DONE;
1355 	} else if (data->state == SUCCESS) {
1356 		ret->decision = data->use_result_ind ?
1357 			DECISION_UNCOND_SUCC : DECISION_COND_SUCC;
1358 		/*
1359 		 * It is possible for the server to reply with AKA
1360 		 * Notification, so we must allow the method to continue and
1361 		 * not only accept EAP-Success at this point.
1362 		 */
1363 		ret->methodState = data->use_result_ind ?
1364 			METHOD_DONE : METHOD_MAY_CONT;
1365 	} else if (data->state == RESULT_SUCCESS)
1366 		ret->methodState = METHOD_CONT;
1367 
1368 	if (ret->methodState == METHOD_DONE) {
1369 		ret->allowNotifications = FALSE;
1370 	}
1371 
1372 	return res;
1373 }
1374 
1375 
1376 static Boolean eap_aka_has_reauth_data(struct eap_sm *sm, void *priv)
1377 {
1378 	struct eap_aka_data *data = priv;
1379 	return data->pseudonym || data->reauth_id;
1380 }
1381 
1382 
1383 static void eap_aka_deinit_for_reauth(struct eap_sm *sm, void *priv)
1384 {
1385 	struct eap_aka_data *data = priv;
1386 	eap_aka_clear_identities(sm, data, CLEAR_EAP_ID);
1387 	data->prev_id = -1;
1388 	wpabuf_free(data->id_msgs);
1389 	data->id_msgs = NULL;
1390 	data->use_result_ind = 0;
1391 	data->kdf_negotiation = 0;
1392 	eap_aka_clear_keys(data, 1);
1393 }
1394 
1395 
1396 static void * eap_aka_init_for_reauth(struct eap_sm *sm, void *priv)
1397 {
1398 	struct eap_aka_data *data = priv;
1399 	data->num_id_req = 0;
1400 	data->num_notification = 0;
1401 	eap_aka_state(data, CONTINUE);
1402 	return priv;
1403 }
1404 
1405 
1406 static const u8 * eap_aka_get_identity(struct eap_sm *sm, void *priv,
1407 				       size_t *len)
1408 {
1409 	struct eap_aka_data *data = priv;
1410 
1411 	if (data->reauth_id) {
1412 		*len = data->reauth_id_len;
1413 		return data->reauth_id;
1414 	}
1415 
1416 	if (data->pseudonym) {
1417 		*len = data->pseudonym_len;
1418 		return data->pseudonym;
1419 	}
1420 
1421 	return NULL;
1422 }
1423 
1424 
1425 static Boolean eap_aka_isKeyAvailable(struct eap_sm *sm, void *priv)
1426 {
1427 	struct eap_aka_data *data = priv;
1428 	return data->state == SUCCESS;
1429 }
1430 
1431 
1432 static u8 * eap_aka_getKey(struct eap_sm *sm, void *priv, size_t *len)
1433 {
1434 	struct eap_aka_data *data = priv;
1435 	u8 *key;
1436 
1437 	if (data->state != SUCCESS)
1438 		return NULL;
1439 
1440 	key = os_malloc(EAP_SIM_KEYING_DATA_LEN);
1441 	if (key == NULL)
1442 		return NULL;
1443 
1444 	*len = EAP_SIM_KEYING_DATA_LEN;
1445 	os_memcpy(key, data->msk, EAP_SIM_KEYING_DATA_LEN);
1446 
1447 	return key;
1448 }
1449 
1450 
1451 static u8 * eap_aka_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
1452 {
1453 	struct eap_aka_data *data = priv;
1454 	u8 *id;
1455 
1456 	if (data->state != SUCCESS)
1457 		return NULL;
1458 
1459 	*len = 1 + EAP_AKA_RAND_LEN + EAP_AKA_AUTN_LEN;
1460 	id = os_malloc(*len);
1461 	if (id == NULL)
1462 		return NULL;
1463 
1464 	id[0] = data->eap_method;
1465 	os_memcpy(id + 1, data->rand, EAP_AKA_RAND_LEN);
1466 	os_memcpy(id + 1 + EAP_AKA_RAND_LEN, data->autn, EAP_AKA_AUTN_LEN);
1467 	wpa_hexdump(MSG_DEBUG, "EAP-AKA: Derived Session-Id", id, *len);
1468 
1469 	return id;
1470 }
1471 
1472 
1473 static u8 * eap_aka_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
1474 {
1475 	struct eap_aka_data *data = priv;
1476 	u8 *key;
1477 
1478 	if (data->state != SUCCESS)
1479 		return NULL;
1480 
1481 	key = os_malloc(EAP_EMSK_LEN);
1482 	if (key == NULL)
1483 		return NULL;
1484 
1485 	*len = EAP_EMSK_LEN;
1486 	os_memcpy(key, data->emsk, EAP_EMSK_LEN);
1487 
1488 	return key;
1489 }
1490 
1491 
1492 int eap_peer_aka_register(void)
1493 {
1494 	struct eap_method *eap;
1495 	int ret;
1496 
1497 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
1498 				    EAP_VENDOR_IETF, EAP_TYPE_AKA, "AKA");
1499 	if (eap == NULL)
1500 		return -1;
1501 
1502 	eap->init = eap_aka_init;
1503 	eap->deinit = eap_aka_deinit;
1504 	eap->process = eap_aka_process;
1505 	eap->isKeyAvailable = eap_aka_isKeyAvailable;
1506 	eap->getKey = eap_aka_getKey;
1507 	eap->getSessionId = eap_aka_get_session_id;
1508 	eap->has_reauth_data = eap_aka_has_reauth_data;
1509 	eap->deinit_for_reauth = eap_aka_deinit_for_reauth;
1510 	eap->init_for_reauth = eap_aka_init_for_reauth;
1511 	eap->get_identity = eap_aka_get_identity;
1512 	eap->get_emsk = eap_aka_get_emsk;
1513 
1514 	ret = eap_peer_method_register(eap);
1515 	if (ret)
1516 		eap_peer_method_free(eap);
1517 	return ret;
1518 }
1519 
1520 
1521 #ifdef EAP_AKA_PRIME
1522 int eap_peer_aka_prime_register(void)
1523 {
1524 	struct eap_method *eap;
1525 	int ret;
1526 
1527 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
1528 				    EAP_VENDOR_IETF, EAP_TYPE_AKA_PRIME,
1529 				    "AKA'");
1530 	if (eap == NULL)
1531 		return -1;
1532 
1533 	eap->init = eap_aka_prime_init;
1534 	eap->deinit = eap_aka_deinit;
1535 	eap->process = eap_aka_process;
1536 	eap->isKeyAvailable = eap_aka_isKeyAvailable;
1537 	eap->getKey = eap_aka_getKey;
1538 	eap->getSessionId = eap_aka_get_session_id;
1539 	eap->has_reauth_data = eap_aka_has_reauth_data;
1540 	eap->deinit_for_reauth = eap_aka_deinit_for_reauth;
1541 	eap->init_for_reauth = eap_aka_init_for_reauth;
1542 	eap->get_identity = eap_aka_get_identity;
1543 	eap->get_emsk = eap_aka_get_emsk;
1544 
1545 	ret = eap_peer_method_register(eap);
1546 	if (ret)
1547 		eap_peer_method_free(eap);
1548 
1549 	return ret;
1550 }
1551 #endif /* EAP_AKA_PRIME */
1552