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1 /*
2  * EAP peer method: EAP-SIM (RFC 4186)
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 "utils/base64.h"
13 #include "pcsc_funcs.h"
14 #include "crypto/crypto.h"
15 #include "crypto/milenage.h"
16 #include "crypto/random.h"
17 #include "eap_peer/eap_i.h"
18 #include "eap_config.h"
19 #include "eap_common/eap_sim_common.h"
20 
21 
22 struct eap_sim_data {
23 	u8 *ver_list;
24 	size_t ver_list_len;
25 	int selected_version;
26 	size_t min_num_chal, num_chal;
27 
28 	u8 kc[3][EAP_SIM_KC_LEN];
29 	u8 sres[3][EAP_SIM_SRES_LEN];
30 	u8 nonce_mt[EAP_SIM_NONCE_MT_LEN], nonce_s[EAP_SIM_NONCE_S_LEN];
31 	u8 mk[EAP_SIM_MK_LEN];
32 	u8 k_aut[EAP_SIM_K_AUT_LEN];
33 	u8 k_encr[EAP_SIM_K_ENCR_LEN];
34 	u8 msk[EAP_SIM_KEYING_DATA_LEN];
35 	u8 emsk[EAP_EMSK_LEN];
36 	u8 rand[3][GSM_RAND_LEN];
37 	u8 reauth_mac[EAP_SIM_MAC_LEN];
38 
39 	int num_id_req, num_notification;
40 	u8 *pseudonym;
41 	size_t pseudonym_len;
42 	u8 *reauth_id;
43 	size_t reauth_id_len;
44 	int reauth;
45 	unsigned int counter, counter_too_small;
46 	u8 *last_eap_identity;
47 	size_t last_eap_identity_len;
48 	enum {
49 		CONTINUE, START_DONE, RESULT_SUCCESS, SUCCESS, FAILURE
50 	} state;
51 	int result_ind, use_result_ind;
52 	int use_pseudonym;
53 	int error_code;
54 	struct crypto_rsa_key *imsi_privacy_key;
55 };
56 
57 
58 #ifndef CONFIG_NO_STDOUT_DEBUG
eap_sim_state_txt(int state)59 static const char * eap_sim_state_txt(int state)
60 {
61 	switch (state) {
62 	case CONTINUE:
63 		return "CONTINUE";
64 	case START_DONE:
65 		return "START_DONE";
66 	case RESULT_SUCCESS:
67 		return "RESULT_SUCCESS";
68 	case SUCCESS:
69 		return "SUCCESS";
70 	case FAILURE:
71 		return "FAILURE";
72 	default:
73 		return "?";
74 	}
75 }
76 #endif /* CONFIG_NO_STDOUT_DEBUG */
77 
78 
eap_sim_state(struct eap_sim_data * data,int state)79 static void eap_sim_state(struct eap_sim_data *data, int state)
80 {
81 	wpa_printf(MSG_DEBUG, "EAP-SIM: %s -> %s",
82 		   eap_sim_state_txt(data->state),
83 		   eap_sim_state_txt(state));
84 	data->state = state;
85 }
86 
87 
eap_sim_init(struct eap_sm * sm)88 static void * eap_sim_init(struct eap_sm *sm)
89 {
90 	struct eap_sim_data *data;
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 	if (random_get_bytes(data->nonce_mt, EAP_SIM_NONCE_MT_LEN)) {
98 		wpa_printf(MSG_WARNING, "EAP-SIM: Failed to get random data "
99 			   "for NONCE_MT");
100 		os_free(data);
101 		return NULL;
102 	}
103 
104 	if (config && config->imsi_privacy_cert) {
105 #ifdef CRYPTO_RSA_OAEP_SHA256
106 		data->imsi_privacy_key = crypto_rsa_key_read(
107 			config->imsi_privacy_cert, false);
108 		if (!data->imsi_privacy_key) {
109 			wpa_printf(MSG_ERROR,
110 				   "EAP-SIM: Failed to read/parse IMSI privacy certificate %s",
111 				   config->imsi_privacy_cert);
112 			os_free(data);
113 			return NULL;
114 		}
115 #else /* CRYPTO_RSA_OAEP_SHA256 */
116 		wpa_printf(MSG_ERROR,
117 			   "EAP-SIM: No support for imsi_privacy_cert in the build");
118 		os_free(data);
119 		return NULL;
120 #endif /* CRYPTO_RSA_OAEP_SHA256 */
121 	}
122 
123 	/* Zero is a valid error code, so we need to initialize */
124 	data->error_code = NO_EAP_METHOD_ERROR;
125 
126 	data->min_num_chal = 2;
127 	if (config && config->phase1) {
128 		char *pos = os_strstr(config->phase1, "sim_min_num_chal=");
129 		if (pos) {
130 			data->min_num_chal = atoi(pos + 17);
131 			if (data->min_num_chal < 2 || data->min_num_chal > 3) {
132 				wpa_printf(MSG_WARNING, "EAP-SIM: Invalid "
133 					   "sim_min_num_chal configuration "
134 					   "(%lu, expected 2 or 3)",
135 					   (unsigned long) data->min_num_chal);
136 #ifdef CRYPTO_RSA_OAEP_SHA256
137 				crypto_rsa_key_free(data->imsi_privacy_key);
138 #endif /* CRYPTO_RSA_OAEP_SHA256 */
139 				os_free(data);
140 				return NULL;
141 			}
142 			wpa_printf(MSG_DEBUG, "EAP-SIM: Set minimum number of "
143 				   "challenges to %lu",
144 				   (unsigned long) data->min_num_chal);
145 		}
146 
147 		data->result_ind = os_strstr(config->phase1, "result_ind=1") !=
148 			NULL;
149 	}
150 
151 	data->use_pseudonym = !sm->init_phase2;
152 	if (config && config->anonymous_identity && data->use_pseudonym) {
153 		data->pseudonym = os_malloc(config->anonymous_identity_len);
154 		if (data->pseudonym) {
155 			os_memcpy(data->pseudonym, config->anonymous_identity,
156 				  config->anonymous_identity_len);
157 			data->pseudonym_len = config->anonymous_identity_len;
158 		}
159 	}
160 
161 	eap_sim_state(data, CONTINUE);
162 
163 	return data;
164 }
165 
166 
eap_sim_clear_keys(struct eap_sim_data * data,int reauth)167 static void eap_sim_clear_keys(struct eap_sim_data *data, int reauth)
168 {
169 	if (!reauth) {
170 		os_memset(data->mk, 0, EAP_SIM_MK_LEN);
171 		os_memset(data->k_aut, 0, EAP_SIM_K_AUT_LEN);
172 		os_memset(data->k_encr, 0, EAP_SIM_K_ENCR_LEN);
173 	}
174 	os_memset(data->kc, 0, 3 * EAP_SIM_KC_LEN);
175 	os_memset(data->sres, 0, 3 * EAP_SIM_SRES_LEN);
176 	os_memset(data->msk, 0, EAP_SIM_KEYING_DATA_LEN);
177 	os_memset(data->emsk, 0, EAP_EMSK_LEN);
178 }
179 
180 
eap_sim_deinit(struct eap_sm * sm,void * priv)181 static void eap_sim_deinit(struct eap_sm *sm, void *priv)
182 {
183 	struct eap_sim_data *data = priv;
184 	if (data) {
185 		os_free(data->ver_list);
186 		os_free(data->pseudonym);
187 		os_free(data->reauth_id);
188 		os_free(data->last_eap_identity);
189 		eap_sim_clear_keys(data, 0);
190 #ifdef CRYPTO_RSA_OAEP_SHA256
191 		crypto_rsa_key_free(data->imsi_privacy_key);
192 #endif /* CRYPTO_RSA_OAEP_SHA256 */
193 		os_free(data);
194 	}
195 }
196 
197 
eap_sim_ext_sim_req(struct eap_sm * sm,struct eap_sim_data * data)198 static int eap_sim_ext_sim_req(struct eap_sm *sm, struct eap_sim_data *data)
199 {
200 	char req[200], *pos, *end;
201 	size_t i;
202 
203 	wpa_printf(MSG_DEBUG, "EAP-SIM: Use external SIM processing");
204 	pos = req;
205 	end = pos + sizeof(req);
206 	pos += os_snprintf(pos, end - pos, "GSM-AUTH");
207 	for (i = 0; i < data->num_chal; i++) {
208 		pos += os_snprintf(pos, end - pos, ":");
209 		pos += wpa_snprintf_hex(pos, end - pos, data->rand[i],
210 					GSM_RAND_LEN);
211 	}
212 
213 	eap_sm_request_sim(sm, req);
214 	return 1;
215 }
216 
217 
eap_sim_ext_sim_result(struct eap_sm * sm,struct eap_sim_data * data,struct eap_peer_config * conf)218 static int eap_sim_ext_sim_result(struct eap_sm *sm, struct eap_sim_data *data,
219 				  struct eap_peer_config *conf)
220 {
221 	char *resp, *pos;
222 	size_t i;
223 
224 	wpa_printf(MSG_DEBUG,
225 		   "EAP-SIM: Use result from external SIM processing");
226 
227 	resp = conf->external_sim_resp;
228 	conf->external_sim_resp = NULL;
229 
230 	if (os_strncmp(resp, "GSM-AUTH:", 9) != 0) {
231 		wpa_printf(MSG_DEBUG, "EAP-SIM: Unrecognized external SIM processing response");
232 		os_free(resp);
233 		return -1;
234 	}
235 
236 	pos = resp + 9;
237 	for (i = 0; i < data->num_chal; i++) {
238 		wpa_hexdump(MSG_DEBUG, "EAP-SIM: RAND",
239 			    data->rand[i], GSM_RAND_LEN);
240 
241 		if (hexstr2bin(pos, data->kc[i], EAP_SIM_KC_LEN) < 0)
242 			goto invalid;
243 		wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: Kc",
244 				data->kc[i], EAP_SIM_KC_LEN);
245 		pos += EAP_SIM_KC_LEN * 2;
246 		if (*pos != ':')
247 			goto invalid;
248 		pos++;
249 
250 		if (hexstr2bin(pos, data->sres[i], EAP_SIM_SRES_LEN) < 0)
251 			goto invalid;
252 		wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: SRES",
253 				data->sres[i], EAP_SIM_SRES_LEN);
254 		pos += EAP_SIM_SRES_LEN * 2;
255 		if (i + 1 < data->num_chal) {
256 			if (*pos != ':')
257 				goto invalid;
258 			pos++;
259 		}
260 	}
261 
262 	os_free(resp);
263 	return 0;
264 
265 invalid:
266 	wpa_printf(MSG_DEBUG, "EAP-SIM: Invalid external SIM processing GSM-AUTH response");
267 	os_free(resp);
268 	return -1;
269 }
270 
271 
eap_sim_gsm_auth(struct eap_sm * sm,struct eap_sim_data * data)272 static int eap_sim_gsm_auth(struct eap_sm *sm, struct eap_sim_data *data)
273 {
274 	struct eap_peer_config *conf;
275 
276 	wpa_printf(MSG_DEBUG, "EAP-SIM: GSM authentication algorithm");
277 
278 	conf = eap_get_config(sm);
279 	if (conf == NULL)
280 		return -1;
281 
282 	if (sm->external_sim) {
283 		if (conf->external_sim_resp)
284 			return eap_sim_ext_sim_result(sm, data, conf);
285 		else
286 			return eap_sim_ext_sim_req(sm, data);
287 	}
288 
289 #ifdef PCSC_FUNCS
290 	if (conf->pcsc) {
291 		if (scard_gsm_auth(sm->scard_ctx, data->rand[0],
292 				   data->sres[0], data->kc[0]) ||
293 		    scard_gsm_auth(sm->scard_ctx, data->rand[1],
294 				   data->sres[1], data->kc[1]) ||
295 		    (data->num_chal > 2 &&
296 		     scard_gsm_auth(sm->scard_ctx, data->rand[2],
297 				    data->sres[2], data->kc[2]))) {
298 			wpa_printf(MSG_DEBUG, "EAP-SIM: GSM SIM "
299 				   "authentication could not be completed");
300 			return -1;
301 		}
302 		return 0;
303 	}
304 #endif /* PCSC_FUNCS */
305 
306 #ifdef CONFIG_SIM_SIMULATOR
307 	if (conf->password) {
308 		u8 opc[16], k[16];
309 		const char *pos;
310 		size_t i;
311 		wpa_printf(MSG_DEBUG, "EAP-SIM: Use internal GSM-Milenage "
312 			   "implementation for authentication");
313 		if (conf->password_len < 65) {
314 			wpa_printf(MSG_DEBUG, "EAP-SIM: invalid GSM-Milenage "
315 				   "password");
316 			return -1;
317 		}
318 		pos = (const char *) conf->password;
319 		if (hexstr2bin(pos, k, 16))
320 			return -1;
321 		pos += 32;
322 		if (*pos != ':')
323 			return -1;
324 		pos++;
325 
326 		if (hexstr2bin(pos, opc, 16))
327 			return -1;
328 
329 		for (i = 0; i < data->num_chal; i++) {
330 			if (gsm_milenage(opc, k, data->rand[i],
331 					 data->sres[i], data->kc[i])) {
332 				wpa_printf(MSG_DEBUG, "EAP-SIM: "
333 					   "GSM-Milenage authentication "
334 					   "could not be completed");
335 				return -1;
336 			}
337 			wpa_hexdump(MSG_DEBUG, "EAP-SIM: RAND",
338 				    data->rand[i], GSM_RAND_LEN);
339 			wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: SRES",
340 					data->sres[i], EAP_SIM_SRES_LEN);
341 			wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: Kc",
342 					data->kc[i], EAP_SIM_KC_LEN);
343 		}
344 		return 0;
345 	}
346 #endif /* CONFIG_SIM_SIMULATOR */
347 
348 #ifdef CONFIG_SIM_HARDCODED
349 	/* These hardcoded Kc and SRES values are used for testing. RAND to
350 	 * KC/SREC mapping is very bogus as far as real authentication is
351 	 * concerned, but it is quite useful for cases where the AS is rotating
352 	 * the order of pre-configured values. */
353 	{
354 		size_t i;
355 
356 		wpa_printf(MSG_DEBUG, "EAP-SIM: Use hardcoded Kc and SRES "
357 			   "values for testing");
358 
359 		for (i = 0; i < data->num_chal; i++) {
360 			if (data->rand[i][0] == 0xaa) {
361 				os_memcpy(data->kc[i],
362 					  "\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7",
363 					  EAP_SIM_KC_LEN);
364 				os_memcpy(data->sres[i], "\xd1\xd2\xd3\xd4",
365 					  EAP_SIM_SRES_LEN);
366 			} else if (data->rand[i][0] == 0xbb) {
367 				os_memcpy(data->kc[i],
368 					  "\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7",
369 					  EAP_SIM_KC_LEN);
370 				os_memcpy(data->sres[i], "\xe1\xe2\xe3\xe4",
371 					  EAP_SIM_SRES_LEN);
372 			} else {
373 				os_memcpy(data->kc[i],
374 					  "\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7",
375 					  EAP_SIM_KC_LEN);
376 				os_memcpy(data->sres[i], "\xf1\xf2\xf3\xf4",
377 					  EAP_SIM_SRES_LEN);
378 			}
379 		}
380 	}
381 
382 	return 0;
383 
384 #else /* CONFIG_SIM_HARDCODED */
385 
386 	wpa_printf(MSG_DEBUG, "EAP-SIM: No GSM authentication algorithm "
387 		   "enabled");
388 	return -1;
389 
390 #endif /* CONFIG_SIM_HARDCODED */
391 }
392 
393 
eap_sim_supported_ver(int version)394 static int eap_sim_supported_ver(int version)
395 {
396 	return version == EAP_SIM_VERSION;
397 }
398 
399 
400 #define CLEAR_PSEUDONYM	0x01
401 #define CLEAR_REAUTH_ID	0x02
402 #define CLEAR_EAP_ID	0x04
403 
eap_sim_clear_identities(struct eap_sm * sm,struct eap_sim_data * data,int id)404 static void eap_sim_clear_identities(struct eap_sm *sm,
405 				     struct eap_sim_data *data, int id)
406 {
407 	if ((id & CLEAR_PSEUDONYM) && data->pseudonym) {
408 		wpa_printf(MSG_DEBUG, "EAP-SIM: forgetting old pseudonym");
409 		os_free(data->pseudonym);
410 		data->pseudonym = NULL;
411 		data->pseudonym_len = 0;
412 		if (data->use_pseudonym)
413 			eap_set_anon_id(sm, NULL, 0);
414 	}
415 	if ((id & CLEAR_REAUTH_ID) && data->reauth_id) {
416 		wpa_printf(MSG_DEBUG, "EAP-SIM: forgetting old reauth_id");
417 		os_free(data->reauth_id);
418 		data->reauth_id = NULL;
419 		data->reauth_id_len = 0;
420 	}
421 	if ((id & CLEAR_EAP_ID) && data->last_eap_identity) {
422 		wpa_printf(MSG_DEBUG, "EAP-SIM: forgetting old eap_id");
423 		os_free(data->last_eap_identity);
424 		data->last_eap_identity = NULL;
425 		data->last_eap_identity_len = 0;
426 	}
427 }
428 
429 
eap_sim_learn_ids(struct eap_sm * sm,struct eap_sim_data * data,struct eap_sim_attrs * attr)430 static int eap_sim_learn_ids(struct eap_sm *sm, struct eap_sim_data *data,
431 			     struct eap_sim_attrs *attr)
432 {
433 	if (attr->next_pseudonym) {
434 		const u8 *identity = NULL;
435 		size_t identity_len = 0;
436 		const u8 *realm = NULL;
437 		size_t realm_len = 0;
438 
439 		wpa_hexdump_ascii(MSG_DEBUG,
440 				  "EAP-SIM: (encr) AT_NEXT_PSEUDONYM",
441 				  attr->next_pseudonym,
442 				  attr->next_pseudonym_len);
443 		os_free(data->pseudonym);
444 
445 		/* Get realm from identities to decorate pseudonym. */
446 		realm = eap_get_config_realm(sm, &realm_len);
447 
448 		data->pseudonym = os_malloc(attr->next_pseudonym_len +
449 					    realm_len);
450 		if (data->pseudonym == NULL) {
451 			wpa_printf(MSG_INFO, "EAP-SIM: (encr) No memory for "
452 				   "next pseudonym");
453 			data->pseudonym_len = 0;
454 			return -1;
455 		}
456 		os_memcpy(data->pseudonym, attr->next_pseudonym,
457 			  attr->next_pseudonym_len);
458 		if (realm_len) {
459 			os_memcpy(data->pseudonym + attr->next_pseudonym_len,
460 				  realm, realm_len);
461 		}
462 		data->pseudonym_len = attr->next_pseudonym_len + realm_len;
463 		if (data->use_pseudonym)
464 			eap_set_anon_id(sm, data->pseudonym,
465 					data->pseudonym_len);
466 	}
467 
468 	if (attr->next_reauth_id) {
469 		os_free(data->reauth_id);
470 		data->reauth_id = os_memdup(attr->next_reauth_id,
471 					    attr->next_reauth_id_len);
472 		if (data->reauth_id == NULL) {
473 			wpa_printf(MSG_INFO, "EAP-SIM: (encr) No memory for "
474 				   "next reauth_id");
475 			data->reauth_id_len = 0;
476 			return -1;
477 		}
478 		data->reauth_id_len = attr->next_reauth_id_len;
479 		wpa_hexdump_ascii(MSG_DEBUG,
480 				  "EAP-SIM: (encr) AT_NEXT_REAUTH_ID",
481 				  data->reauth_id,
482 				  data->reauth_id_len);
483 	}
484 
485 	return 0;
486 }
487 
488 
eap_sim_client_error(struct eap_sim_data * data,u8 id,int err)489 static struct wpabuf * eap_sim_client_error(struct eap_sim_data *data, u8 id,
490 					    int err)
491 {
492 	struct eap_sim_msg *msg;
493 
494 	eap_sim_state(data, FAILURE);
495 	data->num_id_req = 0;
496 	data->num_notification = 0;
497 
498 	wpa_printf(MSG_DEBUG, "EAP-SIM: Send Client-Error (error code %d)",
499 		   err);
500 	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, EAP_TYPE_SIM,
501 			       EAP_SIM_SUBTYPE_CLIENT_ERROR);
502 	eap_sim_msg_add(msg, EAP_SIM_AT_CLIENT_ERROR_CODE, err, NULL, 0);
503 	return eap_sim_msg_finish(msg, EAP_TYPE_SIM, NULL, NULL, 0);
504 }
505 
506 
507 #ifdef CRYPTO_RSA_OAEP_SHA256
508 static struct wpabuf *
eap_sim_encrypt_identity(struct crypto_rsa_key * imsi_privacy_key,const u8 * identity,size_t identity_len,const char * attr)509 eap_sim_encrypt_identity(struct crypto_rsa_key *imsi_privacy_key,
510 			 const u8 *identity, size_t identity_len,
511 			 const char *attr)
512 {
513 	struct wpabuf *imsi_buf, *enc;
514 	char *b64;
515 	size_t b64_len, len;
516 
517 	wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Encrypt permanent identity",
518 			  identity, identity_len);
519 
520 	imsi_buf = wpabuf_alloc_copy(identity, identity_len);
521 	if (!imsi_buf)
522 		return NULL;
523 	enc = crypto_rsa_oaep_sha256_encrypt(imsi_privacy_key, imsi_buf);
524 	wpabuf_free(imsi_buf);
525 	if (!enc)
526 		return NULL;
527 
528 	b64 = base64_encode_no_lf(wpabuf_head(enc), wpabuf_len(enc), &b64_len);
529 	wpabuf_free(enc);
530 	if (!b64)
531 		return NULL;
532 
533 	len = 1 + b64_len;
534 	if (attr)
535 		len += 1 + os_strlen(attr);
536 	enc = wpabuf_alloc(len);
537 	if (!enc) {
538 		os_free(b64);
539 		return NULL;
540 	}
541 	wpabuf_put_u8(enc, '\0');
542 	wpabuf_put_data(enc, b64, b64_len);
543 	os_free(b64);
544 	if (attr) {
545 		wpabuf_put_u8(enc, ',');
546 		wpabuf_put_str(enc, attr);
547 	}
548 	wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Encrypted permanent identity",
549 			  wpabuf_head(enc), wpabuf_len(enc));
550 
551 	return enc;
552 }
553 #endif /* CRYPTO_RSA_OAEP_SHA256 */
554 
555 
eap_sim_response_start(struct eap_sm * sm,struct eap_sim_data * data,u8 id,enum eap_sim_id_req id_req)556 static struct wpabuf * eap_sim_response_start(struct eap_sm *sm,
557 					      struct eap_sim_data *data, u8 id,
558 					      enum eap_sim_id_req id_req)
559 {
560 	const u8 *identity = NULL;
561 	size_t identity_len = 0;
562 	struct eap_sim_msg *msg;
563 	struct wpabuf *resp;
564 	struct wpabuf *enc_identity = NULL;
565 
566 	data->reauth = 0;
567 	if (id_req == ANY_ID && data->reauth_id) {
568 		identity = data->reauth_id;
569 		identity_len = data->reauth_id_len;
570 		data->reauth = 1;
571 	} else if ((id_req == ANY_ID || id_req == FULLAUTH_ID) &&
572 		   data->pseudonym &&
573 		   !eap_sim_anonymous_username(data->pseudonym,
574 					       data->pseudonym_len)) {
575 		identity = data->pseudonym;
576 		identity_len = data->pseudonym_len;
577 		eap_sim_clear_identities(sm, data, CLEAR_REAUTH_ID);
578 	} else if (id_req != NO_ID_REQ) {
579 		if (id_req == PERMANENT_ID && eap_get_config_strict_conservative_peer_mode(sm)) {
580 			wpa_printf(MSG_INFO, "EAP-SIM: permanent_id_req is denied in "
581 				   "the strict conservative peer mode");
582 			eap_notify_permanent_id_req_denied(sm);
583 			return  eap_sim_client_error(data, id, EAP_SIM_UNABLE_TO_PROCESS_PACKET);
584 		}
585 		identity = eap_get_config_identity(sm, &identity_len);
586 		if (identity) {
587 			int ids = CLEAR_PSEUDONYM | CLEAR_REAUTH_ID;
588 
589 			if (data->pseudonym &&
590 			    eap_sim_anonymous_username(data->pseudonym,
591 						       data->pseudonym_len))
592 				ids &= ~CLEAR_PSEUDONYM;
593 			eap_sim_clear_identities(sm, data, ids);
594 		}
595 #ifdef CRYPTO_RSA_OAEP_SHA256
596 		if (identity && data->imsi_privacy_key) {
597 			struct eap_peer_config *config;
598 			const char *attr = NULL;
599 
600 			config = eap_get_config(sm);
601 			if (config)
602 				attr = config->imsi_privacy_attr;
603 			enc_identity = eap_sim_encrypt_identity(
604 				data->imsi_privacy_key,
605 				identity, identity_len, attr);
606 			if (!enc_identity) {
607 				wpa_printf(MSG_INFO,
608 					   "EAP-SIM: Failed to encrypt permanent identity");
609 				return eap_sim_client_error(
610 					data, id,
611 					EAP_SIM_UNABLE_TO_PROCESS_PACKET);
612 			}
613 			identity = wpabuf_head(enc_identity);
614 			identity_len = wpabuf_len(enc_identity);
615 		}
616 #endif /* CRYPTO_RSA_OAEP_SHA256 */
617 	}
618 	if (id_req != NO_ID_REQ)
619 		eap_sim_clear_identities(sm, data, CLEAR_EAP_ID);
620 
621 	wpa_printf(MSG_DEBUG, "Generating EAP-SIM Start (id=%d)", id);
622 	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id,
623 			       EAP_TYPE_SIM, EAP_SIM_SUBTYPE_START);
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 	wpabuf_free(enc_identity);
631 	if (!data->reauth) {
632 		wpa_hexdump(MSG_DEBUG, "   AT_NONCE_MT",
633 			    data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
634 		eap_sim_msg_add(msg, EAP_SIM_AT_NONCE_MT, 0,
635 				data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
636 		wpa_printf(MSG_DEBUG, "   AT_SELECTED_VERSION %d",
637 			   data->selected_version);
638 		eap_sim_msg_add(msg, EAP_SIM_AT_SELECTED_VERSION,
639 				data->selected_version, NULL, 0);
640 	}
641 
642 	resp = eap_sim_msg_finish(msg, EAP_TYPE_SIM, NULL, NULL, 0);
643 	if (resp)
644 		eap_sim_state(data, START_DONE);
645 	return resp;
646 }
647 
648 
eap_sim_response_challenge(struct eap_sim_data * data,u8 id)649 static struct wpabuf * eap_sim_response_challenge(struct eap_sim_data *data,
650 						  u8 id)
651 {
652 	struct eap_sim_msg *msg;
653 
654 	wpa_printf(MSG_DEBUG, "Generating EAP-SIM Challenge (id=%d)", id);
655 	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, EAP_TYPE_SIM,
656 			       EAP_SIM_SUBTYPE_CHALLENGE);
657 	if (data->use_result_ind) {
658 		wpa_printf(MSG_DEBUG, "   AT_RESULT_IND");
659 		eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
660 	}
661 	wpa_printf(MSG_DEBUG, "   AT_MAC");
662 	eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
663 	return eap_sim_msg_finish(msg, EAP_TYPE_SIM, data->k_aut,
664 				  (u8 *) data->sres,
665 				  data->num_chal * EAP_SIM_SRES_LEN);
666 }
667 
668 
eap_sim_response_reauth(struct eap_sim_data * data,u8 id,int counter_too_small,const u8 * nonce_s)669 static struct wpabuf * eap_sim_response_reauth(struct eap_sim_data *data,
670 					       u8 id, int counter_too_small,
671 					       const u8 *nonce_s)
672 {
673 	struct eap_sim_msg *msg;
674 	unsigned int counter;
675 
676 	wpa_printf(MSG_DEBUG, "Generating EAP-SIM Reauthentication (id=%d)",
677 		   id);
678 	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id, EAP_TYPE_SIM,
679 			       EAP_SIM_SUBTYPE_REAUTHENTICATION);
680 	wpa_printf(MSG_DEBUG, "   AT_IV");
681 	wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
682 	eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV, EAP_SIM_AT_ENCR_DATA);
683 
684 	if (counter_too_small) {
685 		wpa_printf(MSG_DEBUG, "   *AT_COUNTER_TOO_SMALL");
686 		eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER_TOO_SMALL, 0, NULL, 0);
687 		counter = data->counter_too_small;
688 	} else
689 		counter = data->counter;
690 
691 	wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", counter);
692 	eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, counter, NULL, 0);
693 
694 	if (eap_sim_msg_add_encr_end(msg, data->k_encr, EAP_SIM_AT_PADDING)) {
695 		wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
696 			   "AT_ENCR_DATA");
697 		eap_sim_msg_free(msg);
698 		return NULL;
699 	}
700 	if (data->use_result_ind) {
701 		wpa_printf(MSG_DEBUG, "   AT_RESULT_IND");
702 		eap_sim_msg_add(msg, EAP_SIM_AT_RESULT_IND, 0, NULL, 0);
703 	}
704 	wpa_printf(MSG_DEBUG, "   AT_MAC");
705 	eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
706 	return eap_sim_msg_finish(msg, EAP_TYPE_SIM, data->k_aut, nonce_s,
707 				  EAP_SIM_NONCE_S_LEN);
708 }
709 
710 
eap_sim_response_notification(struct eap_sim_data * data,u8 id,u16 notification)711 static struct wpabuf * eap_sim_response_notification(struct eap_sim_data *data,
712 						     u8 id, u16 notification)
713 {
714 	struct eap_sim_msg *msg;
715 	u8 *k_aut = (notification & 0x4000) == 0 ? data->k_aut : NULL;
716 
717 	wpa_printf(MSG_DEBUG, "Generating EAP-SIM Notification (id=%d)", id);
718 	msg = eap_sim_msg_init(EAP_CODE_RESPONSE, id,
719 			       EAP_TYPE_SIM, EAP_SIM_SUBTYPE_NOTIFICATION);
720 	if (k_aut && data->reauth) {
721 		wpa_printf(MSG_DEBUG, "   AT_IV");
722 		wpa_printf(MSG_DEBUG, "   AT_ENCR_DATA");
723 		eap_sim_msg_add_encr_start(msg, EAP_SIM_AT_IV,
724 					   EAP_SIM_AT_ENCR_DATA);
725 		wpa_printf(MSG_DEBUG, "   *AT_COUNTER %d", data->counter);
726 		eap_sim_msg_add(msg, EAP_SIM_AT_COUNTER, data->counter,
727 				NULL, 0);
728 		if (eap_sim_msg_add_encr_end(msg, data->k_encr,
729 					     EAP_SIM_AT_PADDING)) {
730 			wpa_printf(MSG_WARNING, "EAP-SIM: Failed to encrypt "
731 				   "AT_ENCR_DATA");
732 			eap_sim_msg_free(msg);
733 			return NULL;
734 		}
735 	}
736 	if (k_aut) {
737 		wpa_printf(MSG_DEBUG, "   AT_MAC");
738 		eap_sim_msg_add_mac(msg, EAP_SIM_AT_MAC);
739 	}
740 	return eap_sim_msg_finish(msg, EAP_TYPE_SIM, k_aut, (u8 *) "", 0);
741 }
742 
743 
eap_sim_process_start(struct eap_sm * sm,struct eap_sim_data * data,u8 id,struct eap_sim_attrs * attr)744 static struct wpabuf * eap_sim_process_start(struct eap_sm *sm,
745 					     struct eap_sim_data *data, u8 id,
746 					     struct eap_sim_attrs *attr)
747 {
748 	int selected_version = -1, id_error;
749 	size_t i;
750 	u8 *pos;
751 
752 	wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Start");
753 	if (attr->version_list == NULL) {
754 		wpa_printf(MSG_INFO, "EAP-SIM: No AT_VERSION_LIST in "
755 			   "SIM/Start");
756 		return eap_sim_client_error(data, id,
757 					    EAP_SIM_UNSUPPORTED_VERSION);
758 	}
759 
760 	os_free(data->ver_list);
761 	data->ver_list = os_memdup(attr->version_list, attr->version_list_len);
762 	if (data->ver_list == NULL) {
763 		wpa_printf(MSG_DEBUG, "EAP-SIM: Failed to allocate "
764 			   "memory for version list");
765 		return eap_sim_client_error(data, id,
766 					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
767 	}
768 	data->ver_list_len = attr->version_list_len;
769 	pos = data->ver_list;
770 	for (i = 0; i < data->ver_list_len / 2; i++) {
771 		int ver = pos[0] * 256 + pos[1];
772 		pos += 2;
773 		if (eap_sim_supported_ver(ver)) {
774 			selected_version = ver;
775 			break;
776 		}
777 	}
778 	if (selected_version < 0) {
779 		wpa_printf(MSG_INFO, "EAP-SIM: Could not find a supported "
780 			   "version");
781 		return eap_sim_client_error(data, id,
782 					    EAP_SIM_UNSUPPORTED_VERSION);
783 	}
784 	wpa_printf(MSG_DEBUG, "EAP-SIM: Selected Version %d",
785 		   selected_version);
786 	data->selected_version = selected_version;
787 
788 	id_error = 0;
789 	switch (attr->id_req) {
790 	case NO_ID_REQ:
791 		break;
792 	case ANY_ID:
793 		if (data->num_id_req > 0)
794 			id_error++;
795 		data->num_id_req++;
796 		break;
797 	case FULLAUTH_ID:
798 		if (data->num_id_req > 1)
799 			id_error++;
800 		data->num_id_req++;
801 		break;
802 	case PERMANENT_ID:
803 		if (data->num_id_req > 2)
804 			id_error++;
805 		data->num_id_req++;
806 		break;
807 	}
808 	if (id_error) {
809 		wpa_printf(MSG_INFO, "EAP-SIM: Too many ID requests "
810 			   "used within one authentication");
811 		return eap_sim_client_error(data, id,
812 					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
813 	}
814 
815 	return eap_sim_response_start(sm, data, id, attr->id_req);
816 }
817 
818 
eap_sim_process_challenge(struct eap_sm * sm,struct eap_sim_data * data,u8 id,const struct wpabuf * reqData,struct eap_sim_attrs * attr)819 static struct wpabuf * eap_sim_process_challenge(struct eap_sm *sm,
820 						 struct eap_sim_data *data,
821 						 u8 id,
822 						 const struct wpabuf *reqData,
823 						 struct eap_sim_attrs *attr)
824 {
825 	const u8 *identity;
826 	size_t identity_len;
827 	struct eap_sim_attrs eattr;
828 	int res;
829 
830 	wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Challenge");
831 	if (data->state != START_DONE) {
832 		wpa_printf(MSG_DEBUG,
833 			   "EAP-SIM: Unexpected Challenge in state %s",
834 			   eap_sim_state_txt(data->state));
835 		return eap_sim_client_error(data, id,
836 					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
837 	}
838 	data->reauth = 0;
839 	if (!attr->mac || !attr->rand) {
840 		wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
841 			   "did not include%s%s",
842 			   !attr->mac ? " AT_MAC" : "",
843 			   !attr->rand ? " AT_RAND" : "");
844 		return eap_sim_client_error(data, id,
845 					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
846 	}
847 
848 	wpa_printf(MSG_DEBUG, "EAP-SIM: %lu challenges",
849 		   (unsigned long) attr->num_chal);
850 	if (attr->num_chal < data->min_num_chal) {
851 		wpa_printf(MSG_INFO, "EAP-SIM: Insufficient number of "
852 			   "challenges (%lu)", (unsigned long) attr->num_chal);
853 		return eap_sim_client_error(data, id,
854 					    EAP_SIM_INSUFFICIENT_NUM_OF_CHAL);
855 	}
856 	if (attr->num_chal > 3) {
857 		wpa_printf(MSG_INFO, "EAP-SIM: Too many challenges "
858 			   "(%lu)", (unsigned long) attr->num_chal);
859 		return eap_sim_client_error(data, id,
860 					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
861 	}
862 
863 	/* Verify that RANDs are different */
864 	if (os_memcmp(attr->rand, attr->rand + GSM_RAND_LEN,
865 		   GSM_RAND_LEN) == 0 ||
866 	    (attr->num_chal > 2 &&
867 	     (os_memcmp(attr->rand, attr->rand + 2 * GSM_RAND_LEN,
868 			GSM_RAND_LEN) == 0 ||
869 	      os_memcmp(attr->rand + GSM_RAND_LEN,
870 			attr->rand + 2 * GSM_RAND_LEN,
871 			GSM_RAND_LEN) == 0))) {
872 		wpa_printf(MSG_INFO, "EAP-SIM: Same RAND used multiple times");
873 		return eap_sim_client_error(data, id,
874 					    EAP_SIM_RAND_NOT_FRESH);
875 	}
876 
877 	os_memcpy(data->rand, attr->rand, attr->num_chal * GSM_RAND_LEN);
878 	data->num_chal = attr->num_chal;
879 
880 	res = eap_sim_gsm_auth(sm, data);
881 	if (res > 0) {
882 		wpa_printf(MSG_DEBUG, "EAP-SIM: Wait for external SIM processing");
883 		return NULL;
884 	}
885 	if (res) {
886 		wpa_printf(MSG_WARNING, "EAP-SIM: GSM authentication failed");
887 		return eap_sim_client_error(data, id,
888 					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
889 	}
890 	if (data->last_eap_identity) {
891 		identity = data->last_eap_identity;
892 		identity_len = data->last_eap_identity_len;
893 	} else if (data->pseudonym &&
894 		   !eap_sim_anonymous_username(data->pseudonym,
895 					       data->pseudonym_len)) {
896 		identity = data->pseudonym;
897 		identity_len = data->pseudonym_len;
898 	} else {
899 		struct eap_peer_config *config;
900 
901 		config = eap_get_config(sm);
902 		if (config && config->imsi_identity) {
903 			identity = config->imsi_identity;
904 			identity_len = config->imsi_identity_len;
905 		} else {
906 			identity = eap_get_config_identity(sm, &identity_len);
907 		}
908 	}
909 	wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Selected identity for MK "
910 			  "derivation", identity, identity_len);
911 	eap_sim_derive_mk(identity, identity_len, data->nonce_mt,
912 			  data->selected_version, data->ver_list,
913 			  data->ver_list_len, data->num_chal,
914 			  (const u8 *) data->kc, data->mk);
915 	eap_sim_derive_keys(data->mk, data->k_encr, data->k_aut, data->msk,
916 			    data->emsk);
917 	if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, data->nonce_mt,
918 			       EAP_SIM_NONCE_MT_LEN)) {
919 		wpa_printf(MSG_WARNING, "EAP-SIM: Challenge message "
920 			   "used invalid AT_MAC");
921 #ifdef TEST_FUZZ
922 		wpa_printf(MSG_INFO,
923 			   "TEST: Ignore AT_MAC mismatch for fuzz testing");
924 #else /* TEST_FUZZ */
925 		return eap_sim_client_error(data, id,
926 					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
927 #endif /* TEST_FUZZ */
928 	}
929 
930 	/* Old reauthentication identity must not be used anymore. In
931 	 * other words, if no new reauth identity is received, full
932 	 * authentication will be used on next reauthentication (using
933 	 * pseudonym identity or permanent identity). */
934 	eap_sim_clear_identities(sm, data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
935 
936 	if (attr->encr_data) {
937 		u8 *decrypted;
938 		decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
939 					       attr->encr_data_len, attr->iv,
940 					       &eattr, 0);
941 		if (decrypted == NULL) {
942 			return eap_sim_client_error(
943 				data, id, EAP_SIM_UNABLE_TO_PROCESS_PACKET);
944 		}
945 		eap_sim_learn_ids(sm, data, &eattr);
946 		os_free(decrypted);
947 	}
948 
949 	if (data->result_ind && attr->result_ind)
950 		data->use_result_ind = 1;
951 
952 	if (data->state != FAILURE) {
953 		eap_sim_state(data, data->use_result_ind ?
954 			      RESULT_SUCCESS : SUCCESS);
955 	}
956 
957 	data->num_id_req = 0;
958 	data->num_notification = 0;
959 	/* RFC 4186 specifies that counter is initialized to one after
960 	 * fullauth, but initializing it to zero makes it easier to implement
961 	 * reauth verification. */
962 	data->counter = 0;
963 	return eap_sim_response_challenge(data, id);
964 }
965 
966 
eap_sim_process_notification_reauth(struct eap_sim_data * data,struct eap_sim_attrs * attr)967 static int eap_sim_process_notification_reauth(struct eap_sim_data *data,
968 					       struct eap_sim_attrs *attr)
969 {
970 	struct eap_sim_attrs eattr;
971 	u8 *decrypted;
972 
973 	if (attr->encr_data == NULL || attr->iv == NULL) {
974 		wpa_printf(MSG_WARNING, "EAP-SIM: Notification message after "
975 			   "reauth did not include encrypted data");
976 		return -1;
977 	}
978 
979 	decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
980 				       attr->encr_data_len, attr->iv, &eattr,
981 				       0);
982 	if (decrypted == NULL) {
983 		wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
984 			   "data from notification message");
985 		return -1;
986 	}
987 
988 	if (eattr.counter < 0 || (size_t) eattr.counter != data->counter) {
989 		wpa_printf(MSG_WARNING, "EAP-SIM: Counter in notification "
990 			   "message does not match with counter in reauth "
991 			   "message");
992 		os_free(decrypted);
993 		return -1;
994 	}
995 
996 	os_free(decrypted);
997 	return 0;
998 }
999 
1000 
eap_sim_process_notification_auth(struct eap_sim_data * data,const struct wpabuf * reqData,struct eap_sim_attrs * attr)1001 static int eap_sim_process_notification_auth(struct eap_sim_data *data,
1002 					     const struct wpabuf *reqData,
1003 					     struct eap_sim_attrs *attr)
1004 {
1005 	if (attr->mac == NULL) {
1006 		wpa_printf(MSG_INFO, "EAP-SIM: no AT_MAC in after_auth "
1007 			   "Notification message");
1008 		return -1;
1009 	}
1010 
1011 	if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, (u8 *) "", 0))
1012 	{
1013 		wpa_printf(MSG_WARNING, "EAP-SIM: Notification message "
1014 			   "used invalid AT_MAC");
1015 		return -1;
1016 	}
1017 
1018 	if (data->reauth &&
1019 	    eap_sim_process_notification_reauth(data, attr)) {
1020 		wpa_printf(MSG_WARNING, "EAP-SIM: Invalid notification "
1021 			   "message after reauth");
1022 		return -1;
1023 	}
1024 
1025 	return 0;
1026 }
1027 
1028 
eap_sim_process_notification(struct eap_sm * sm,struct eap_sim_data * data,u8 id,const struct wpabuf * reqData,struct eap_sim_attrs * attr)1029 static struct wpabuf * eap_sim_process_notification(
1030 	struct eap_sm *sm, struct eap_sim_data *data, u8 id,
1031 	const struct wpabuf *reqData, struct eap_sim_attrs *attr)
1032 {
1033 	wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Notification");
1034 	if (data->num_notification > 0) {
1035 		wpa_printf(MSG_INFO, "EAP-SIM: too many notification "
1036 			   "rounds (only one allowed)");
1037 		return eap_sim_client_error(data, id,
1038 					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
1039 	}
1040 	data->num_notification++;
1041 	if (attr->notification == -1) {
1042 		wpa_printf(MSG_INFO, "EAP-SIM: no AT_NOTIFICATION in "
1043 			   "Notification message");
1044 		return eap_sim_client_error(data, id,
1045 					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
1046 	}
1047 
1048 	if ((attr->notification & 0x4000) == 0 &&
1049 	    eap_sim_process_notification_auth(data, reqData, attr)) {
1050 		return eap_sim_client_error(data, id,
1051 					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
1052 	}
1053 
1054 	eap_sim_report_notification(sm->msg_ctx, attr->notification, 0);
1055 	if (attr->notification >= 0 && attr->notification < 32768) {
1056 		data->error_code = attr->notification;
1057 		eap_sim_state(data, FAILURE);
1058 	} else if (attr->notification == EAP_SIM_SUCCESS &&
1059 		   data->state == RESULT_SUCCESS)
1060 		eap_sim_state(data, SUCCESS);
1061 	return eap_sim_response_notification(data, id, attr->notification);
1062 }
1063 
1064 
eap_sim_process_reauthentication(struct eap_sm * sm,struct eap_sim_data * data,u8 id,const struct wpabuf * reqData,struct eap_sim_attrs * attr)1065 static struct wpabuf * eap_sim_process_reauthentication(
1066 	struct eap_sm *sm, struct eap_sim_data *data, u8 id,
1067 	const struct wpabuf *reqData, struct eap_sim_attrs *attr)
1068 {
1069 	struct eap_sim_attrs eattr;
1070 	u8 *decrypted;
1071 
1072 	wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Reauthentication");
1073 
1074 	if (data->reauth_id == NULL) {
1075 		wpa_printf(MSG_WARNING, "EAP-SIM: Server is trying "
1076 			   "reauthentication, but no reauth_id available");
1077 		return eap_sim_client_error(data, id,
1078 					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
1079 	}
1080 
1081 	data->reauth = 1;
1082 	if (eap_sim_verify_mac(data->k_aut, reqData, attr->mac, (u8 *) "", 0))
1083 	{
1084 		wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
1085 			   "did not have valid AT_MAC");
1086 #ifdef TEST_FUZZ
1087 		wpa_printf(MSG_INFO,
1088 			   "TEST: Ignore AT_MAC mismatch for fuzz testing");
1089 #else /* TEST_FUZZ */
1090 		return eap_sim_client_error(data, id,
1091 					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
1092 #endif /* TEST_FUZZ */
1093 	}
1094 
1095 	/* At this stage the received MAC has been verified. Use this MAC for
1096 	 * reauth Session-Id calculation if all other checks pass.
1097 	 * The peer does not use the local MAC but the received MAC in deriving
1098 	 * Session-Id. */
1099 #ifdef TEST_FUZZ
1100 	if (attr->mac)
1101 		os_memcpy(data->reauth_mac, attr->mac, EAP_SIM_MAC_LEN);
1102 	else
1103 		os_memset(data->reauth_mac, 0x12, EAP_SIM_MAC_LEN);
1104 #else /* TEST_FUZZ */
1105 	os_memcpy(data->reauth_mac, attr->mac, EAP_SIM_MAC_LEN);
1106 #endif /* TEST_FUZZ */
1107 	wpa_hexdump(MSG_DEBUG, "EAP-SIM: Server MAC",
1108 		    data->reauth_mac, EAP_SIM_MAC_LEN);
1109 
1110 	if (attr->encr_data == NULL || attr->iv == NULL) {
1111 		wpa_printf(MSG_WARNING, "EAP-SIM: Reauthentication "
1112 			   "message did not include encrypted data");
1113 		return eap_sim_client_error(data, id,
1114 					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
1115 	}
1116 
1117 	decrypted = eap_sim_parse_encr(data->k_encr, attr->encr_data,
1118 				       attr->encr_data_len, attr->iv, &eattr,
1119 				       0);
1120 	if (decrypted == NULL) {
1121 		wpa_printf(MSG_WARNING, "EAP-SIM: Failed to parse encrypted "
1122 			   "data from reauthentication message");
1123 		return eap_sim_client_error(data, id,
1124 					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
1125 	}
1126 
1127 	if (eattr.nonce_s == NULL || eattr.counter < 0) {
1128 		wpa_printf(MSG_INFO, "EAP-SIM: (encr) No%s%s in reauth packet",
1129 			   !eattr.nonce_s ? " AT_NONCE_S" : "",
1130 			   eattr.counter < 0 ? " AT_COUNTER" : "");
1131 		os_free(decrypted);
1132 		return eap_sim_client_error(data, id,
1133 					    EAP_SIM_UNABLE_TO_PROCESS_PACKET);
1134 	}
1135 
1136 	if (eattr.counter < 0 || (size_t) eattr.counter <= data->counter) {
1137 		struct wpabuf *res;
1138 		wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid counter "
1139 			   "(%d <= %d)", eattr.counter, data->counter);
1140 		data->counter_too_small = eattr.counter;
1141 
1142 		/* Reply using Re-auth w/ AT_COUNTER_TOO_SMALL. The current
1143 		 * reauth_id must not be used to start a new reauthentication.
1144 		 * However, since it was used in the last EAP-Response-Identity
1145 		 * packet, it has to saved for the following fullauth to be
1146 		 * used in MK derivation. */
1147 		os_free(data->last_eap_identity);
1148 		data->last_eap_identity = data->reauth_id;
1149 		data->last_eap_identity_len = data->reauth_id_len;
1150 		data->reauth_id = NULL;
1151 		data->reauth_id_len = 0;
1152 
1153 		res = eap_sim_response_reauth(data, id, 1, eattr.nonce_s);
1154 		os_free(decrypted);
1155 
1156 		return res;
1157 	}
1158 	data->counter = eattr.counter;
1159 
1160 	os_memcpy(data->nonce_s, eattr.nonce_s, EAP_SIM_NONCE_S_LEN);
1161 	wpa_hexdump(MSG_DEBUG, "EAP-SIM: (encr) AT_NONCE_S",
1162 		    data->nonce_s, EAP_SIM_NONCE_S_LEN);
1163 
1164 	eap_sim_derive_keys_reauth(data->counter,
1165 				   data->reauth_id, data->reauth_id_len,
1166 				   data->nonce_s, data->mk, data->msk,
1167 				   data->emsk);
1168 	eap_sim_clear_identities(sm, data, CLEAR_REAUTH_ID | CLEAR_EAP_ID);
1169 	eap_sim_learn_ids(sm, data, &eattr);
1170 
1171 	if (data->result_ind && attr->result_ind)
1172 		data->use_result_ind = 1;
1173 
1174 	if (data->state != FAILURE) {
1175 		eap_sim_state(data, data->use_result_ind ?
1176 			      RESULT_SUCCESS : SUCCESS);
1177 	}
1178 
1179 	data->num_id_req = 0;
1180 	data->num_notification = 0;
1181 	if (data->counter > EAP_SIM_MAX_FAST_REAUTHS) {
1182 		wpa_printf(MSG_DEBUG, "EAP-SIM: Maximum number of "
1183 			   "fast reauths performed - force fullauth");
1184 		eap_sim_clear_identities(sm, data,
1185 					 CLEAR_REAUTH_ID | CLEAR_EAP_ID);
1186 	}
1187 	os_free(decrypted);
1188 	return eap_sim_response_reauth(data, id, 0, data->nonce_s);
1189 }
1190 
1191 
eap_sim_process(struct eap_sm * sm,void * priv,struct eap_method_ret * ret,const struct wpabuf * reqData)1192 static struct wpabuf * eap_sim_process(struct eap_sm *sm, void *priv,
1193 				       struct eap_method_ret *ret,
1194 				       const struct wpabuf *reqData)
1195 {
1196 	struct eap_sim_data *data = priv;
1197 	const struct eap_hdr *req;
1198 	u8 subtype, id;
1199 	struct wpabuf *res;
1200 	const u8 *pos;
1201 	struct eap_sim_attrs attr;
1202 	size_t len;
1203 
1204 	wpa_hexdump_buf(MSG_DEBUG, "EAP-SIM: EAP data", reqData);
1205 	if (eap_get_config_identity(sm, &len) == NULL) {
1206 		wpa_printf(MSG_INFO, "EAP-SIM: Identity not configured");
1207 		eap_sm_request_identity(sm);
1208 		ret->ignore = true;
1209 		return NULL;
1210 	}
1211 
1212 	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_SIM, reqData, &len);
1213 	if (pos == NULL || len < 3) {
1214 		ret->ignore = true;
1215 		return NULL;
1216 	}
1217 	req = wpabuf_head(reqData);
1218 	id = req->identifier;
1219 	len = be_to_host16(req->length);
1220 
1221 	ret->ignore = false;
1222 	ret->methodState = METHOD_MAY_CONT;
1223 	ret->decision = DECISION_FAIL;
1224 	ret->allowNotifications = true;
1225 
1226 	subtype = *pos++;
1227 	wpa_printf(MSG_DEBUG, "EAP-SIM: Subtype=%d", subtype);
1228 	pos += 2; /* Reserved */
1229 
1230 	if (eap_sim_parse_attr(pos, wpabuf_head_u8(reqData) + len, &attr, 0,
1231 			       0)) {
1232 		res = eap_sim_client_error(data, id,
1233 					   EAP_SIM_UNABLE_TO_PROCESS_PACKET);
1234 		goto done;
1235 	}
1236 
1237 	switch (subtype) {
1238 	case EAP_SIM_SUBTYPE_START:
1239 		res = eap_sim_process_start(sm, data, id, &attr);
1240 		break;
1241 	case EAP_SIM_SUBTYPE_CHALLENGE:
1242 		res = eap_sim_process_challenge(sm, data, id, reqData, &attr);
1243 		break;
1244 	case EAP_SIM_SUBTYPE_NOTIFICATION:
1245 		res = eap_sim_process_notification(sm, data, id, reqData,
1246 						   &attr);
1247 		break;
1248 	case EAP_SIM_SUBTYPE_REAUTHENTICATION:
1249 		res = eap_sim_process_reauthentication(sm, data, id, reqData,
1250 						       &attr);
1251 		break;
1252 	case EAP_SIM_SUBTYPE_CLIENT_ERROR:
1253 		wpa_printf(MSG_DEBUG, "EAP-SIM: subtype Client-Error");
1254 		res = eap_sim_client_error(data, id,
1255 					   EAP_SIM_UNABLE_TO_PROCESS_PACKET);
1256 		break;
1257 	default:
1258 		wpa_printf(MSG_DEBUG, "EAP-SIM: Unknown subtype=%d", subtype);
1259 		res = eap_sim_client_error(data, id,
1260 					   EAP_SIM_UNABLE_TO_PROCESS_PACKET);
1261 		break;
1262 	}
1263 
1264 done:
1265 	if (data->state == FAILURE) {
1266 		ret->decision = DECISION_FAIL;
1267 		ret->methodState = METHOD_DONE;
1268 	} else if (data->state == SUCCESS) {
1269 		ret->decision = data->use_result_ind ?
1270 			DECISION_UNCOND_SUCC : DECISION_COND_SUCC;
1271 		ret->methodState = data->use_result_ind ?
1272 			METHOD_DONE : METHOD_MAY_CONT;
1273 	} else if (data->state == RESULT_SUCCESS)
1274 		ret->methodState = METHOD_CONT;
1275 
1276 	if (ret->methodState == METHOD_DONE) {
1277 		ret->allowNotifications = false;
1278 	}
1279 
1280 	return res;
1281 }
1282 
1283 
eap_sim_has_reauth_data(struct eap_sm * sm,void * priv)1284 static bool eap_sim_has_reauth_data(struct eap_sm *sm, void *priv)
1285 {
1286 	struct eap_sim_data *data = priv;
1287 	return data->pseudonym || data->reauth_id;
1288 }
1289 
1290 
eap_sim_deinit_for_reauth(struct eap_sm * sm,void * priv)1291 static void eap_sim_deinit_for_reauth(struct eap_sm *sm, void *priv)
1292 {
1293 	struct eap_sim_data *data = priv;
1294 	eap_sim_clear_identities(sm, data, CLEAR_EAP_ID);
1295 	data->use_result_ind = 0;
1296 	eap_sim_clear_keys(data, 1);
1297 }
1298 
1299 
eap_sim_init_for_reauth(struct eap_sm * sm,void * priv)1300 static void * eap_sim_init_for_reauth(struct eap_sm *sm, void *priv)
1301 {
1302 	struct eap_sim_data *data = priv;
1303 	if (random_get_bytes(data->nonce_mt, EAP_SIM_NONCE_MT_LEN)) {
1304 		wpa_printf(MSG_WARNING, "EAP-SIM: Failed to get random data "
1305 			   "for NONCE_MT");
1306 		eap_sim_deinit(sm, data);
1307 		return NULL;
1308 	}
1309 	data->num_id_req = 0;
1310 	data->num_notification = 0;
1311 	eap_sim_state(data, CONTINUE);
1312 	return priv;
1313 }
1314 
1315 
eap_sim_get_identity(struct eap_sm * sm,void * priv,size_t * len)1316 static const u8 * eap_sim_get_identity(struct eap_sm *sm, void *priv,
1317 				       size_t *len)
1318 {
1319 	struct eap_sim_data *data = priv;
1320 
1321 	if (data->reauth_id) {
1322 		*len = data->reauth_id_len;
1323 		return data->reauth_id;
1324 	}
1325 
1326 	if (data->pseudonym) {
1327 		*len = data->pseudonym_len;
1328 		return data->pseudonym;
1329 	}
1330 
1331 	return NULL;
1332 }
1333 
1334 
eap_sim_isKeyAvailable(struct eap_sm * sm,void * priv)1335 static bool eap_sim_isKeyAvailable(struct eap_sm *sm, void *priv)
1336 {
1337 	struct eap_sim_data *data = priv;
1338 	return data->state == SUCCESS;
1339 }
1340 
1341 
eap_sim_getKey(struct eap_sm * sm,void * priv,size_t * len)1342 static u8 * eap_sim_getKey(struct eap_sm *sm, void *priv, size_t *len)
1343 {
1344 	struct eap_sim_data *data = priv;
1345 	u8 *key;
1346 
1347 	if (data->state != SUCCESS)
1348 		return NULL;
1349 
1350 	key = os_memdup(data->msk, EAP_SIM_KEYING_DATA_LEN);
1351 	if (key == NULL)
1352 		return NULL;
1353 
1354 	*len = EAP_SIM_KEYING_DATA_LEN;
1355 
1356 	return key;
1357 }
1358 
1359 
eap_sim_get_session_id(struct eap_sm * sm,void * priv,size_t * len)1360 static u8 * eap_sim_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
1361 {
1362 	struct eap_sim_data *data = priv;
1363 	u8 *id;
1364 
1365 	if (data->state != SUCCESS)
1366 		return NULL;
1367 
1368 	if (!data->reauth)
1369 		*len = 1 + data->num_chal * GSM_RAND_LEN + EAP_SIM_NONCE_MT_LEN;
1370 	else
1371 		*len = 1 + EAP_SIM_NONCE_S_LEN + EAP_SIM_MAC_LEN;
1372 	id = os_malloc(*len);
1373 	if (id == NULL)
1374 		return NULL;
1375 
1376 	id[0] = EAP_TYPE_SIM;
1377 	if (!data->reauth) {
1378 		os_memcpy(id + 1, data->rand, data->num_chal * GSM_RAND_LEN);
1379 		os_memcpy(id + 1 + data->num_chal * GSM_RAND_LEN,
1380 			  data->nonce_mt, EAP_SIM_NONCE_MT_LEN);
1381 	} else {
1382 		os_memcpy(id + 1, data->nonce_s, EAP_SIM_NONCE_S_LEN);
1383 		os_memcpy(id + 1 + EAP_SIM_NONCE_S_LEN, data->reauth_mac,
1384 			  EAP_SIM_MAC_LEN);
1385 	}
1386 	wpa_hexdump(MSG_DEBUG, "EAP-SIM: Derived Session-Id", id, *len);
1387 
1388 	return id;
1389 }
1390 
1391 
eap_sim_get_emsk(struct eap_sm * sm,void * priv,size_t * len)1392 static u8 * eap_sim_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
1393 {
1394 	struct eap_sim_data *data = priv;
1395 	u8 *key;
1396 
1397 	if (data->state != SUCCESS)
1398 		return NULL;
1399 
1400 	key = os_memdup(data->emsk, EAP_EMSK_LEN);
1401 	if (key == NULL)
1402 		return NULL;
1403 
1404 	*len = EAP_EMSK_LEN;
1405 
1406 	return key;
1407 }
1408 
1409 
eap_sim_get_error_code(void * priv)1410 static int eap_sim_get_error_code(void *priv)
1411 {
1412 	struct eap_sim_data *data = priv;
1413 	int current_data_error;
1414 
1415 	if (!data)
1416 		return NO_EAP_METHOD_ERROR;
1417 
1418 	current_data_error = data->error_code;
1419 
1420 	/* Now reset for next transaction */
1421 	data->error_code = NO_EAP_METHOD_ERROR;
1422 
1423 	return current_data_error;
1424 }
1425 
1426 
eap_peer_sim_register(void)1427 int eap_peer_sim_register(void)
1428 {
1429 	struct eap_method *eap;
1430 
1431 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
1432 				    EAP_VENDOR_IETF, EAP_TYPE_SIM, "SIM");
1433 	if (eap == NULL)
1434 		return -1;
1435 
1436 	eap->init = eap_sim_init;
1437 	eap->deinit = eap_sim_deinit;
1438 	eap->process = eap_sim_process;
1439 	eap->isKeyAvailable = eap_sim_isKeyAvailable;
1440 	eap->getKey = eap_sim_getKey;
1441 	eap->getSessionId = eap_sim_get_session_id;
1442 	eap->has_reauth_data = eap_sim_has_reauth_data;
1443 	eap->deinit_for_reauth = eap_sim_deinit_for_reauth;
1444 	eap->init_for_reauth = eap_sim_init_for_reauth;
1445 	eap->get_identity = eap_sim_get_identity;
1446 	eap->get_emsk = eap_sim_get_emsk;
1447 	eap->get_error_code = eap_sim_get_error_code;
1448 
1449 	return eap_peer_method_register(eap);
1450 }
1451