1 /*
2  * EAP peer method: EAP-GPSK (RFC 5433)
3  * Copyright (c) 2006-2014, 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 "crypto/random.h"
13 #include "eap_peer/eap_i.h"
14 #include "eap_common/eap_gpsk_common.h"
15 
16 struct eap_gpsk_data {
17 	enum { GPSK_1, GPSK_3, SUCCESS, FAILURE } state;
18 	u8 rand_server[EAP_GPSK_RAND_LEN];
19 	u8 rand_peer[EAP_GPSK_RAND_LEN];
20 	u8 msk[EAP_MSK_LEN];
21 	u8 emsk[EAP_EMSK_LEN];
22 	u8 sk[EAP_GPSK_MAX_SK_LEN];
23 	size_t sk_len;
24 	u8 pk[EAP_GPSK_MAX_PK_LEN];
25 	size_t pk_len;
26 	u8 session_id[128];
27 	size_t id_len;
28 	u8 *id_peer;
29 	size_t id_peer_len;
30 	u8 *id_server;
31 	size_t id_server_len;
32 	int vendor; /* CSuite/Specifier */
33 	int specifier; /* CSuite/Specifier */
34 	u8 *psk;
35 	size_t psk_len;
36 	u16 forced_cipher; /* force cipher or 0 to allow all supported */
37 };
38 
39 
40 static struct wpabuf * eap_gpsk_send_gpsk_2(struct eap_gpsk_data *data,
41 					    u8 identifier,
42 					    const u8 *csuite_list,
43 					    size_t csuite_list_len);
44 static struct wpabuf * eap_gpsk_send_gpsk_4(struct eap_gpsk_data *data,
45 					    u8 identifier);
46 
47 
48 #ifndef CONFIG_NO_STDOUT_DEBUG
49 static const char * eap_gpsk_state_txt(int state)
50 {
51 	switch (state) {
52 	case GPSK_1:
53 		return "GPSK-1";
54 	case GPSK_3:
55 		return "GPSK-3";
56 	case SUCCESS:
57 		return "SUCCESS";
58 	case FAILURE:
59 		return "FAILURE";
60 	default:
61 		return "?";
62 	}
63 }
64 #endif /* CONFIG_NO_STDOUT_DEBUG */
65 
66 
67 static void eap_gpsk_state(struct eap_gpsk_data *data, int state)
68 {
69 	wpa_printf(MSG_DEBUG, "EAP-GPSK: %s -> %s",
70 		   eap_gpsk_state_txt(data->state),
71 		   eap_gpsk_state_txt(state));
72 	data->state = state;
73 }
74 
75 
76 static void eap_gpsk_deinit(struct eap_sm *sm, void *priv);
77 
78 
79 static void * eap_gpsk_init(struct eap_sm *sm)
80 {
81 	struct eap_gpsk_data *data;
82 	const u8 *identity, *password;
83 	size_t identity_len, password_len;
84 	const char *phase1;
85 
86 	password = eap_get_config_password(sm, &password_len);
87 	if (password == NULL) {
88 		wpa_printf(MSG_INFO, "EAP-GPSK: No key (password) configured");
89 		return NULL;
90 	}
91 
92 	data = os_zalloc(sizeof(*data));
93 	if (data == NULL)
94 		return NULL;
95 	data->state = GPSK_1;
96 
97 	identity = eap_get_config_identity(sm, &identity_len);
98 	if (identity) {
99 		data->id_peer = os_malloc(identity_len);
100 		if (data->id_peer == NULL) {
101 			eap_gpsk_deinit(sm, data);
102 			return NULL;
103 		}
104 		os_memcpy(data->id_peer, identity, identity_len);
105 		data->id_peer_len = identity_len;
106 	}
107 
108 	phase1 = eap_get_config_phase1(sm);
109 	if (phase1) {
110 		const char *pos;
111 
112 		pos = os_strstr(phase1, "cipher=");
113 		if (pos) {
114 			data->forced_cipher = atoi(pos + 7);
115 			wpa_printf(MSG_DEBUG, "EAP-GPSK: Forced cipher %u",
116 				   data->forced_cipher);
117 		}
118 	}
119 
120 	data->psk = os_malloc(password_len);
121 	if (data->psk == NULL) {
122 		eap_gpsk_deinit(sm, data);
123 		return NULL;
124 	}
125 	os_memcpy(data->psk, password, password_len);
126 	data->psk_len = password_len;
127 
128 	return data;
129 }
130 
131 
132 static void eap_gpsk_deinit(struct eap_sm *sm, void *priv)
133 {
134 	struct eap_gpsk_data *data = priv;
135 	os_free(data->id_server);
136 	os_free(data->id_peer);
137 	os_free(data->psk);
138 	os_free(data);
139 }
140 
141 
142 static const u8 * eap_gpsk_process_id_server(struct eap_gpsk_data *data,
143 					     const u8 *pos, const u8 *end)
144 {
145 	u16 alen;
146 
147 	if (end - pos < 2) {
148 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short GPSK-1 packet");
149 		return NULL;
150 	}
151 	alen = WPA_GET_BE16(pos);
152 	pos += 2;
153 	if (end - pos < alen) {
154 		wpa_printf(MSG_DEBUG, "EAP-GPSK: ID_Server overflow");
155 		return NULL;
156 	}
157 	os_free(data->id_server);
158 	data->id_server = os_malloc(alen);
159 	if (data->id_server == NULL) {
160 		wpa_printf(MSG_DEBUG, "EAP-GPSK: No memory for ID_Server");
161 		return NULL;
162 	}
163 	os_memcpy(data->id_server, pos, alen);
164 	data->id_server_len = alen;
165 	wpa_hexdump_ascii(MSG_DEBUG, "EAP-GPSK: ID_Server",
166 			  data->id_server, data->id_server_len);
167 	pos += alen;
168 
169 	return pos;
170 }
171 
172 
173 static const u8 * eap_gpsk_process_rand_server(struct eap_gpsk_data *data,
174 					       const u8 *pos, const u8 *end)
175 {
176 	if (pos == NULL)
177 		return NULL;
178 
179 	if (end - pos < EAP_GPSK_RAND_LEN) {
180 		wpa_printf(MSG_DEBUG, "EAP-GPSK: RAND_Server overflow");
181 		return NULL;
182 	}
183 	os_memcpy(data->rand_server, pos, EAP_GPSK_RAND_LEN);
184 	wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Server",
185 		    data->rand_server, EAP_GPSK_RAND_LEN);
186 	pos += EAP_GPSK_RAND_LEN;
187 
188 	return pos;
189 }
190 
191 
192 static int eap_gpsk_select_csuite(struct eap_sm *sm,
193 				  struct eap_gpsk_data *data,
194 				  const u8 *csuite_list,
195 				  size_t csuite_list_len)
196 {
197 	struct eap_gpsk_csuite *csuite;
198 	int i, count;
199 
200 	count = csuite_list_len / sizeof(struct eap_gpsk_csuite);
201 	data->vendor = EAP_GPSK_VENDOR_IETF;
202 	data->specifier = EAP_GPSK_CIPHER_RESERVED;
203 	csuite = (struct eap_gpsk_csuite *) csuite_list;
204 	for (i = 0; i < count; i++) {
205 		int vendor, specifier;
206 		vendor = WPA_GET_BE32(csuite->vendor);
207 		specifier = WPA_GET_BE16(csuite->specifier);
208 		wpa_printf(MSG_DEBUG, "EAP-GPSK: CSuite[%d]: %d:%d",
209 			   i, vendor, specifier);
210 		if (data->vendor == EAP_GPSK_VENDOR_IETF &&
211 		    data->specifier == EAP_GPSK_CIPHER_RESERVED &&
212 		    eap_gpsk_supported_ciphersuite(vendor, specifier) &&
213 		    (!data->forced_cipher || data->forced_cipher == specifier))
214 		{
215 			data->vendor = vendor;
216 			data->specifier = specifier;
217 		}
218 		csuite++;
219 	}
220 	if (data->vendor == EAP_GPSK_VENDOR_IETF &&
221 	    data->specifier == EAP_GPSK_CIPHER_RESERVED) {
222 		wpa_msg(sm->msg_ctx, MSG_INFO, "EAP-GPSK: No supported "
223 			"ciphersuite found");
224 		return -1;
225 	}
226 	wpa_printf(MSG_DEBUG, "EAP-GPSK: Selected ciphersuite %d:%d",
227 		   data->vendor, data->specifier);
228 
229 	return 0;
230 }
231 
232 
233 static const u8 * eap_gpsk_process_csuite_list(struct eap_sm *sm,
234 					       struct eap_gpsk_data *data,
235 					       const u8 **list,
236 					       size_t *list_len,
237 					       const u8 *pos, const u8 *end)
238 {
239 	if (pos == NULL)
240 		return NULL;
241 
242 	if (end - pos < 2) {
243 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short GPSK-1 packet");
244 		return NULL;
245 	}
246 	*list_len = WPA_GET_BE16(pos);
247 	pos += 2;
248 	if (end - pos < (int) *list_len) {
249 		wpa_printf(MSG_DEBUG, "EAP-GPSK: CSuite_List overflow");
250 		return NULL;
251 	}
252 	if (*list_len == 0 || (*list_len % sizeof(struct eap_gpsk_csuite))) {
253 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Invalid CSuite_List len %lu",
254 			   (unsigned long) *list_len);
255 		return NULL;
256 	}
257 	*list = pos;
258 	pos += *list_len;
259 
260 	if (eap_gpsk_select_csuite(sm, data, *list, *list_len) < 0)
261 		return NULL;
262 
263 	return pos;
264 }
265 
266 
267 static struct wpabuf * eap_gpsk_process_gpsk_1(struct eap_sm *sm,
268 					       struct eap_gpsk_data *data,
269 					       struct eap_method_ret *ret,
270 					       const struct wpabuf *reqData,
271 					       const u8 *payload,
272 					       size_t payload_len)
273 {
274 	size_t csuite_list_len;
275 	const u8 *csuite_list, *pos, *end;
276 	struct wpabuf *resp;
277 
278 	if (data->state != GPSK_1) {
279 		ret->ignore = TRUE;
280 		return NULL;
281 	}
282 
283 	wpa_printf(MSG_DEBUG, "EAP-GPSK: Received Request/GPSK-1");
284 
285 	end = payload + payload_len;
286 
287 	pos = eap_gpsk_process_id_server(data, payload, end);
288 	pos = eap_gpsk_process_rand_server(data, pos, end);
289 	pos = eap_gpsk_process_csuite_list(sm, data, &csuite_list,
290 					   &csuite_list_len, pos, end);
291 	if (pos == NULL) {
292 		ret->methodState = METHOD_DONE;
293 		eap_gpsk_state(data, FAILURE);
294 		return NULL;
295 	}
296 
297 	resp = eap_gpsk_send_gpsk_2(data, eap_get_id(reqData),
298 				    csuite_list, csuite_list_len);
299 	if (resp == NULL)
300 		return NULL;
301 
302 	eap_gpsk_state(data, GPSK_3);
303 
304 	return resp;
305 }
306 
307 
308 static struct wpabuf * eap_gpsk_send_gpsk_2(struct eap_gpsk_data *data,
309 					    u8 identifier,
310 					    const u8 *csuite_list,
311 					    size_t csuite_list_len)
312 {
313 	struct wpabuf *resp;
314 	size_t len, miclen;
315 	u8 *rpos, *start;
316 	struct eap_gpsk_csuite *csuite;
317 
318 	wpa_printf(MSG_DEBUG, "EAP-GPSK: Sending Response/GPSK-2");
319 
320 	miclen = eap_gpsk_mic_len(data->vendor, data->specifier);
321 	len = 1 + 2 + data->id_peer_len + 2 + data->id_server_len +
322 		2 * EAP_GPSK_RAND_LEN + 2 + csuite_list_len +
323 		sizeof(struct eap_gpsk_csuite) + 2 + miclen;
324 
325 	resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_GPSK, len,
326 			     EAP_CODE_RESPONSE, identifier);
327 	if (resp == NULL)
328 		return NULL;
329 
330 	wpabuf_put_u8(resp, EAP_GPSK_OPCODE_GPSK_2);
331 	start = wpabuf_put(resp, 0);
332 
333 	wpa_hexdump_ascii(MSG_DEBUG, "EAP-GPSK: ID_Peer",
334 			  data->id_peer, data->id_peer_len);
335 	wpabuf_put_be16(resp, data->id_peer_len);
336 	wpabuf_put_data(resp, data->id_peer, data->id_peer_len);
337 
338 	wpabuf_put_be16(resp, data->id_server_len);
339 	wpabuf_put_data(resp, data->id_server, data->id_server_len);
340 
341 	if (random_get_bytes(data->rand_peer, EAP_GPSK_RAND_LEN)) {
342 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Failed to get random data "
343 			   "for RAND_Peer");
344 		eap_gpsk_state(data, FAILURE);
345 		wpabuf_free(resp);
346 		return NULL;
347 	}
348 	wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Peer",
349 		    data->rand_peer, EAP_GPSK_RAND_LEN);
350 	wpabuf_put_data(resp, data->rand_peer, EAP_GPSK_RAND_LEN);
351 	wpabuf_put_data(resp, data->rand_server, EAP_GPSK_RAND_LEN);
352 
353 	wpabuf_put_be16(resp, csuite_list_len);
354 	wpabuf_put_data(resp, csuite_list, csuite_list_len);
355 
356 	csuite = wpabuf_put(resp, sizeof(*csuite));
357 	WPA_PUT_BE32(csuite->vendor, data->vendor);
358 	WPA_PUT_BE16(csuite->specifier, data->specifier);
359 
360 	if (eap_gpsk_derive_keys(data->psk, data->psk_len,
361 				 data->vendor, data->specifier,
362 				 data->rand_peer, data->rand_server,
363 				 data->id_peer, data->id_peer_len,
364 				 data->id_server, data->id_server_len,
365 				 data->msk, data->emsk,
366 				 data->sk, &data->sk_len,
367 				 data->pk, &data->pk_len) < 0) {
368 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Failed to derive keys");
369 		eap_gpsk_state(data, FAILURE);
370 		wpabuf_free(resp);
371 		return NULL;
372 	}
373 
374 	if (eap_gpsk_derive_session_id(data->psk, data->psk_len,
375 				       data->vendor, data->specifier,
376 				       data->rand_peer, data->rand_server,
377 				       data->id_peer, data->id_peer_len,
378 				       data->id_server, data->id_server_len,
379 				       EAP_TYPE_GPSK,
380 				       data->session_id, &data->id_len) < 0) {
381 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Failed to derive Session-Id");
382 		eap_gpsk_state(data, FAILURE);
383 		wpabuf_free(resp);
384 		return NULL;
385 	}
386 	wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Derived Session-Id",
387 		    data->session_id, data->id_len);
388 
389 	/* No PD_Payload_1 */
390 	wpabuf_put_be16(resp, 0);
391 
392 	rpos = wpabuf_put(resp, miclen);
393 	if (eap_gpsk_compute_mic(data->sk, data->sk_len, data->vendor,
394 				 data->specifier, start, rpos - start, rpos) <
395 	    0) {
396 		eap_gpsk_state(data, FAILURE);
397 		wpabuf_free(resp);
398 		return NULL;
399 	}
400 
401 	return resp;
402 }
403 
404 
405 static const u8 * eap_gpsk_validate_rand(struct eap_gpsk_data *data,
406 					 const u8 *pos, const u8 *end)
407 {
408 	if (end - pos < EAP_GPSK_RAND_LEN) {
409 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for "
410 			   "RAND_Peer");
411 		return NULL;
412 	}
413 	if (os_memcmp(pos, data->rand_peer, EAP_GPSK_RAND_LEN) != 0) {
414 		wpa_printf(MSG_DEBUG, "EAP-GPSK: RAND_Peer in GPSK-2 and "
415 			   "GPSK-3 did not match");
416 		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Peer in GPSK-2",
417 			    data->rand_peer, EAP_GPSK_RAND_LEN);
418 		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Peer in GPSK-3",
419 			    pos, EAP_GPSK_RAND_LEN);
420 		return NULL;
421 	}
422 	pos += EAP_GPSK_RAND_LEN;
423 
424 	if (end - pos < EAP_GPSK_RAND_LEN) {
425 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for "
426 			   "RAND_Server");
427 		return NULL;
428 	}
429 	if (os_memcmp(pos, data->rand_server, EAP_GPSK_RAND_LEN) != 0) {
430 		wpa_printf(MSG_DEBUG, "EAP-GPSK: RAND_Server in GPSK-1 and "
431 			   "GPSK-3 did not match");
432 		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Server in GPSK-1",
433 			    data->rand_server, EAP_GPSK_RAND_LEN);
434 		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Server in GPSK-3",
435 			    pos, EAP_GPSK_RAND_LEN);
436 		return NULL;
437 	}
438 	pos += EAP_GPSK_RAND_LEN;
439 
440 	return pos;
441 }
442 
443 
444 static const u8 * eap_gpsk_validate_id_server(struct eap_gpsk_data *data,
445 					      const u8 *pos, const u8 *end)
446 {
447 	size_t len;
448 
449 	if (pos == NULL)
450 		return NULL;
451 
452 	if (end - pos < (int) 2) {
453 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for "
454 			   "length(ID_Server)");
455 		return NULL;
456 	}
457 
458 	len = WPA_GET_BE16(pos);
459 	pos += 2;
460 
461 	if (end - pos < (int) len) {
462 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for "
463 			   "ID_Server");
464 		return NULL;
465 	}
466 
467 	if (len != data->id_server_len ||
468 	    os_memcmp(pos, data->id_server, len) != 0) {
469 		wpa_printf(MSG_INFO, "EAP-GPSK: ID_Server did not match with "
470 			   "the one used in GPSK-1");
471 		wpa_hexdump_ascii(MSG_DEBUG, "EAP-GPSK: ID_Server in GPSK-1",
472 				  data->id_server, data->id_server_len);
473 		wpa_hexdump_ascii(MSG_DEBUG, "EAP-GPSK: ID_Server in GPSK-3",
474 				  pos, len);
475 		return NULL;
476 	}
477 
478 	pos += len;
479 
480 	return pos;
481 }
482 
483 
484 static const u8 * eap_gpsk_validate_csuite(struct eap_gpsk_data *data,
485 					   const u8 *pos, const u8 *end)
486 {
487 	int vendor, specifier;
488 	const struct eap_gpsk_csuite *csuite;
489 
490 	if (pos == NULL)
491 		return NULL;
492 
493 	if (end - pos < (int) sizeof(*csuite)) {
494 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for "
495 			   "CSuite_Sel");
496 		return NULL;
497 	}
498 	csuite = (const struct eap_gpsk_csuite *) pos;
499 	vendor = WPA_GET_BE32(csuite->vendor);
500 	specifier = WPA_GET_BE16(csuite->specifier);
501 	pos += sizeof(*csuite);
502 	if (vendor != data->vendor || specifier != data->specifier) {
503 		wpa_printf(MSG_DEBUG, "EAP-GPSK: CSuite_Sel (%d:%d) does not "
504 			   "match with the one sent in GPSK-2 (%d:%d)",
505 			   vendor, specifier, data->vendor, data->specifier);
506 		return NULL;
507 	}
508 
509 	return pos;
510 }
511 
512 
513 static const u8 * eap_gpsk_validate_pd_payload_2(struct eap_gpsk_data *data,
514 						 const u8 *pos, const u8 *end)
515 {
516 	u16 alen;
517 
518 	if (pos == NULL)
519 		return NULL;
520 
521 	if (end - pos < 2) {
522 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for "
523 			   "PD_Payload_2 length");
524 		return NULL;
525 	}
526 	alen = WPA_GET_BE16(pos);
527 	pos += 2;
528 	if (end - pos < alen) {
529 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for "
530 			   "%d-octet PD_Payload_2", alen);
531 		return NULL;
532 	}
533 	wpa_hexdump(MSG_DEBUG, "EAP-GPSK: PD_Payload_2", pos, alen);
534 	pos += alen;
535 
536 	return pos;
537 }
538 
539 
540 static const u8 * eap_gpsk_validate_gpsk_3_mic(struct eap_gpsk_data *data,
541 					       const u8 *payload,
542 					       const u8 *pos, const u8 *end)
543 {
544 	size_t miclen;
545 	u8 mic[EAP_GPSK_MAX_MIC_LEN];
546 
547 	if (pos == NULL)
548 		return NULL;
549 
550 	miclen = eap_gpsk_mic_len(data->vendor, data->specifier);
551 	if (end - pos < (int) miclen) {
552 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for MIC "
553 			   "(left=%lu miclen=%lu)",
554 			   (unsigned long) (end - pos),
555 			   (unsigned long) miclen);
556 		return NULL;
557 	}
558 	if (eap_gpsk_compute_mic(data->sk, data->sk_len, data->vendor,
559 				 data->specifier, payload, pos - payload, mic)
560 	    < 0) {
561 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Failed to compute MIC");
562 		return NULL;
563 	}
564 	if (os_memcmp(mic, pos, miclen) != 0) {
565 		wpa_printf(MSG_INFO, "EAP-GPSK: Incorrect MIC in GPSK-3");
566 		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Received MIC", pos, miclen);
567 		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Computed MIC", mic, miclen);
568 		return NULL;
569 	}
570 	pos += miclen;
571 
572 	return pos;
573 }
574 
575 
576 static struct wpabuf * eap_gpsk_process_gpsk_3(struct eap_sm *sm,
577 					       struct eap_gpsk_data *data,
578 					       struct eap_method_ret *ret,
579 					       const struct wpabuf *reqData,
580 					       const u8 *payload,
581 					       size_t payload_len)
582 {
583 	struct wpabuf *resp;
584 	const u8 *pos, *end;
585 
586 	if (data->state != GPSK_3) {
587 		ret->ignore = TRUE;
588 		return NULL;
589 	}
590 
591 	wpa_printf(MSG_DEBUG, "EAP-GPSK: Received Request/GPSK-3");
592 
593 	end = payload + payload_len;
594 
595 	pos = eap_gpsk_validate_rand(data, payload, end);
596 	pos = eap_gpsk_validate_id_server(data, pos, end);
597 	pos = eap_gpsk_validate_csuite(data, pos, end);
598 	pos = eap_gpsk_validate_pd_payload_2(data, pos, end);
599 	pos = eap_gpsk_validate_gpsk_3_mic(data, payload, pos, end);
600 
601 	if (pos == NULL) {
602 		eap_gpsk_state(data, FAILURE);
603 		return NULL;
604 	}
605 	if (pos != end) {
606 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Ignored %lu bytes of extra "
607 			   "data in the end of GPSK-2",
608 			   (unsigned long) (end - pos));
609 	}
610 
611 	resp = eap_gpsk_send_gpsk_4(data, eap_get_id(reqData));
612 	if (resp == NULL)
613 		return NULL;
614 
615 	eap_gpsk_state(data, SUCCESS);
616 	ret->methodState = METHOD_DONE;
617 	ret->decision = DECISION_UNCOND_SUCC;
618 
619 	return resp;
620 }
621 
622 
623 static struct wpabuf * eap_gpsk_send_gpsk_4(struct eap_gpsk_data *data,
624 					    u8 identifier)
625 {
626 	struct wpabuf *resp;
627 	u8 *rpos, *start;
628 	size_t mlen;
629 
630 	wpa_printf(MSG_DEBUG, "EAP-GPSK: Sending Response/GPSK-4");
631 
632 	mlen = eap_gpsk_mic_len(data->vendor, data->specifier);
633 
634 	resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_GPSK, 1 + 2 + mlen,
635 			     EAP_CODE_RESPONSE, identifier);
636 	if (resp == NULL)
637 		return NULL;
638 
639 	wpabuf_put_u8(resp, EAP_GPSK_OPCODE_GPSK_4);
640 	start = wpabuf_put(resp, 0);
641 
642 	/* No PD_Payload_3 */
643 	wpabuf_put_be16(resp, 0);
644 
645 	rpos = wpabuf_put(resp, mlen);
646 	if (eap_gpsk_compute_mic(data->sk, data->sk_len, data->vendor,
647 				 data->specifier, start, rpos - start, rpos) <
648 	    0) {
649 		eap_gpsk_state(data, FAILURE);
650 		wpabuf_free(resp);
651 		return NULL;
652 	}
653 
654 	return resp;
655 }
656 
657 
658 static struct wpabuf * eap_gpsk_process(struct eap_sm *sm, void *priv,
659 					struct eap_method_ret *ret,
660 					const struct wpabuf *reqData)
661 {
662 	struct eap_gpsk_data *data = priv;
663 	struct wpabuf *resp;
664 	const u8 *pos;
665 	size_t len;
666 
667 	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_GPSK, reqData, &len);
668 	if (pos == NULL || len < 1) {
669 		ret->ignore = TRUE;
670 		return NULL;
671 	}
672 
673 	wpa_printf(MSG_DEBUG, "EAP-GPSK: Received frame: opcode %d", *pos);
674 
675 	ret->ignore = FALSE;
676 	ret->methodState = METHOD_MAY_CONT;
677 	ret->decision = DECISION_FAIL;
678 	ret->allowNotifications = FALSE;
679 
680 	switch (*pos) {
681 	case EAP_GPSK_OPCODE_GPSK_1:
682 		resp = eap_gpsk_process_gpsk_1(sm, data, ret, reqData,
683 					       pos + 1, len - 1);
684 		break;
685 	case EAP_GPSK_OPCODE_GPSK_3:
686 		resp = eap_gpsk_process_gpsk_3(sm, data, ret, reqData,
687 					       pos + 1, len - 1);
688 		break;
689 	default:
690 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Ignoring message with "
691 			   "unknown opcode %d", *pos);
692 		ret->ignore = TRUE;
693 		return NULL;
694 	}
695 
696 	return resp;
697 }
698 
699 
700 static Boolean eap_gpsk_isKeyAvailable(struct eap_sm *sm, void *priv)
701 {
702 	struct eap_gpsk_data *data = priv;
703 	return data->state == SUCCESS;
704 }
705 
706 
707 static u8 * eap_gpsk_getKey(struct eap_sm *sm, void *priv, size_t *len)
708 {
709 	struct eap_gpsk_data *data = priv;
710 	u8 *key;
711 
712 	if (data->state != SUCCESS)
713 		return NULL;
714 
715 	key = os_malloc(EAP_MSK_LEN);
716 	if (key == NULL)
717 		return NULL;
718 	os_memcpy(key, data->msk, EAP_MSK_LEN);
719 	*len = EAP_MSK_LEN;
720 
721 	return key;
722 }
723 
724 
725 static u8 * eap_gpsk_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
726 {
727 	struct eap_gpsk_data *data = priv;
728 	u8 *key;
729 
730 	if (data->state != SUCCESS)
731 		return NULL;
732 
733 	key = os_malloc(EAP_EMSK_LEN);
734 	if (key == NULL)
735 		return NULL;
736 	os_memcpy(key, data->emsk, EAP_EMSK_LEN);
737 	*len = EAP_EMSK_LEN;
738 
739 	return key;
740 }
741 
742 
743 static u8 * eap_gpsk_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
744 {
745 	struct eap_gpsk_data *data = priv;
746 	u8 *sid;
747 
748 	if (data->state != SUCCESS)
749 		return NULL;
750 
751 	sid = os_malloc(data->id_len);
752 	if (sid == NULL)
753 		return NULL;
754 	os_memcpy(sid, data->session_id, data->id_len);
755 	*len = data->id_len;
756 
757 	return sid;
758 }
759 
760 
761 int eap_peer_gpsk_register(void)
762 {
763 	struct eap_method *eap;
764 	int ret;
765 
766 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
767 				    EAP_VENDOR_IETF, EAP_TYPE_GPSK, "GPSK");
768 	if (eap == NULL)
769 		return -1;
770 
771 	eap->init = eap_gpsk_init;
772 	eap->deinit = eap_gpsk_deinit;
773 	eap->process = eap_gpsk_process;
774 	eap->isKeyAvailable = eap_gpsk_isKeyAvailable;
775 	eap->getKey = eap_gpsk_getKey;
776 	eap->get_emsk = eap_gpsk_get_emsk;
777 	eap->getSessionId = eap_gpsk_get_session_id;
778 
779 	ret = eap_peer_method_register(eap);
780 	if (ret)
781 		eap_peer_method_free(eap);
782 	return ret;
783 }
784