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