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1 /*
2  * EAP peer method: EAP-GPSK (draft-ietf-emu-eap-gpsk-08.txt)
3  * Copyright (c) 2006-2007, Jouni Malinen <j@w1.fi>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  *
9  * Alternatively, this software may be distributed under the terms of BSD
10  * license.
11  *
12  * See README and COPYING for more details.
13  */
14 
15 #include "includes.h"
16 
17 #include "common.h"
18 #include "eap_i.h"
19 #include "config_ssid.h"
20 #include "eap_gpsk_common.h"
21 
22 struct eap_gpsk_data {
23 	enum { GPSK_1, GPSK_3, SUCCESS, FAILURE } state;
24 	u8 rand_server[EAP_GPSK_RAND_LEN];
25 	u8 rand_peer[EAP_GPSK_RAND_LEN];
26 	u8 msk[EAP_MSK_LEN];
27 	u8 emsk[EAP_EMSK_LEN];
28 	u8 sk[EAP_GPSK_MAX_SK_LEN];
29 	size_t sk_len;
30 	u8 pk[EAP_GPSK_MAX_PK_LEN];
31 	size_t pk_len;
32 	u8 session_id;
33 	int session_id_set;
34 	u8 *id_peer;
35 	size_t id_peer_len;
36 	u8 *id_server;
37 	size_t id_server_len;
38 	int vendor; /* CSuite/Specifier */
39 	int specifier; /* CSuite/Specifier */
40 	u8 *psk;
41 	size_t psk_len;
42 };
43 
44 
45 static u8 * eap_gpsk_send_gpsk_2(struct eap_gpsk_data *data, u8 identifier,
46 				 const u8 *csuite_list, size_t csuite_list_len,
47 				 size_t *respDataLen);
48 static u8 * eap_gpsk_send_gpsk_4(struct eap_gpsk_data *data, u8 identifier,
49 				 size_t *respDataLen);
50 
51 
52 #ifndef CONFIG_NO_STDOUT_DEBUG
eap_gpsk_state_txt(int state)53 static const char * eap_gpsk_state_txt(int state)
54 {
55 	switch (state) {
56 	case GPSK_1:
57 		return "GPSK-1";
58 	case GPSK_3:
59 		return "GPSK-3";
60 	case SUCCESS:
61 		return "SUCCESS";
62 	case FAILURE:
63 		return "FAILURE";
64 	default:
65 		return "?";
66 	}
67 }
68 #endif /* CONFIG_NO_STDOUT_DEBUG */
69 
70 
eap_gpsk_state(struct eap_gpsk_data * data,int state)71 static void eap_gpsk_state(struct eap_gpsk_data *data, int state)
72 {
73 	wpa_printf(MSG_DEBUG, "EAP-GPSK: %s -> %s",
74 		   eap_gpsk_state_txt(data->state),
75 		   eap_gpsk_state_txt(state));
76 	data->state = state;
77 }
78 
79 
80 static void eap_gpsk_deinit(struct eap_sm *sm, void *priv);
81 
82 
eap_gpsk_init(struct eap_sm * sm)83 static void * eap_gpsk_init(struct eap_sm *sm)
84 {
85 	struct wpa_ssid *config = eap_get_config(sm);
86 	struct eap_gpsk_data *data;
87 
88 	if (config == NULL) {
89 		wpa_printf(MSG_INFO, "EAP-GPSK: No configuration found");
90 		return NULL;
91 	}
92 
93 	if (config->eappsk == NULL) {
94 		wpa_printf(MSG_INFO, "EAP-GPSK: No key (eappsk) configured");
95 		return NULL;
96 	}
97 
98 	data = os_zalloc(sizeof(*data));
99 	if (data == NULL)
100 		return NULL;
101 	data->state = GPSK_1;
102 
103 	if (config->nai) {
104 		data->id_peer = os_malloc(config->nai_len);
105 		if (data->id_peer == NULL) {
106 			eap_gpsk_deinit(sm, data);
107 			return NULL;
108 		}
109 		os_memcpy(data->id_peer, config->nai, config->nai_len);
110 		data->id_peer_len = config->nai_len;
111 	}
112 
113 	data->psk = os_malloc(config->eappsk_len);
114 	if (data->psk == NULL) {
115 		eap_gpsk_deinit(sm, data);
116 		return NULL;
117 	}
118 	os_memcpy(data->psk, config->eappsk, config->eappsk_len);
119 	data->psk_len = config->eappsk_len;
120 
121 	return data;
122 }
123 
124 
eap_gpsk_deinit(struct eap_sm * sm,void * priv)125 static void eap_gpsk_deinit(struct eap_sm *sm, void *priv)
126 {
127 	struct eap_gpsk_data *data = priv;
128 	os_free(data->id_server);
129 	os_free(data->id_peer);
130 	os_free(data->psk);
131 	os_free(data);
132 }
133 
134 
eap_gpsk_process_id_server(struct eap_gpsk_data * data,const u8 * pos,const u8 * end)135 const u8 * eap_gpsk_process_id_server(struct eap_gpsk_data *data,
136 				      const u8 *pos, const u8 *end)
137 {
138 	u16 alen;
139 
140 	if (end - pos < 2) {
141 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short GPSK-1 packet");
142 		return NULL;
143 	}
144 	alen = WPA_GET_BE16(pos);
145 	pos += 2;
146 	if (end - pos < alen) {
147 		wpa_printf(MSG_DEBUG, "EAP-GPSK: ID_Server overflow");
148 		return NULL;
149 	}
150 	os_free(data->id_server);
151 	data->id_server = os_malloc(alen);
152 	if (data->id_server == NULL) {
153 		wpa_printf(MSG_DEBUG, "EAP-GPSK: No memory for ID_Server");
154 		return NULL;
155 	}
156 	os_memcpy(data->id_server, pos, alen);
157 	data->id_server_len = alen;
158 	wpa_hexdump_ascii(MSG_DEBUG, "EAP-GPSK: ID_Server",
159 			  data->id_server, data->id_server_len);
160 	pos += alen;
161 
162 	return pos;
163 }
164 
165 
eap_gpsk_process_rand_server(struct eap_gpsk_data * data,const u8 * pos,const u8 * end)166 const u8 * eap_gpsk_process_rand_server(struct eap_gpsk_data *data,
167 					const u8 *pos, const u8 *end)
168 {
169 	if (pos == NULL)
170 		return NULL;
171 
172 	if (end - pos < EAP_GPSK_RAND_LEN) {
173 		wpa_printf(MSG_DEBUG, "EAP-GPSK: RAND_Server overflow");
174 		return NULL;
175 	}
176 	os_memcpy(data->rand_server, pos, EAP_GPSK_RAND_LEN);
177 	wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Server",
178 		    data->rand_server, EAP_GPSK_RAND_LEN);
179 	pos += EAP_GPSK_RAND_LEN;
180 
181 	return pos;
182 }
183 
184 
eap_gpsk_select_csuite(struct eap_sm * sm,struct eap_gpsk_data * data,const u8 * csuite_list,size_t csuite_list_len)185 static int eap_gpsk_select_csuite(struct eap_sm *sm,
186 				  struct eap_gpsk_data *data,
187 				  const u8 *csuite_list,
188 				  size_t csuite_list_len)
189 {
190 	struct eap_gpsk_csuite *csuite;
191 	int i, count;
192 
193 	count = csuite_list_len / sizeof(struct eap_gpsk_csuite);
194 	data->vendor = EAP_GPSK_VENDOR_IETF;
195 	data->specifier = EAP_GPSK_CIPHER_RESERVED;
196 	csuite = (struct eap_gpsk_csuite *) csuite_list;
197 	for (i = 0; i < count; i++) {
198 		int vendor, specifier;
199 		vendor = WPA_GET_BE32(csuite->vendor);
200 		specifier = WPA_GET_BE16(csuite->specifier);
201 		wpa_printf(MSG_DEBUG, "EAP-GPSK: CSuite[%d]: %d:%d",
202 			   i, vendor, specifier);
203 		if (data->vendor == EAP_GPSK_VENDOR_IETF &&
204 		    data->specifier == EAP_GPSK_CIPHER_RESERVED &&
205 		    eap_gpsk_supported_ciphersuite(vendor, specifier)) {
206 			data->vendor = vendor;
207 			data->specifier = specifier;
208 		}
209 		csuite++;
210 	}
211 	if (data->vendor == EAP_GPSK_VENDOR_IETF &&
212 	    data->specifier == EAP_GPSK_CIPHER_RESERVED) {
213 		wpa_msg(sm->msg_ctx, MSG_INFO, "EAP-GPSK: No supported "
214 			"ciphersuite found");
215 		return -1;
216 	}
217 	wpa_printf(MSG_DEBUG, "EAP-GPSK: Selected ciphersuite %d:%d",
218 		   data->vendor, data->specifier);
219 
220 	return 0;
221 }
222 
223 
eap_gpsk_process_csuite_list(struct eap_sm * sm,struct eap_gpsk_data * data,const u8 ** list,size_t * list_len,const u8 * pos,const u8 * end)224 const u8 * eap_gpsk_process_csuite_list(struct eap_sm *sm,
225 					struct eap_gpsk_data *data,
226 					const u8 **list, size_t *list_len,
227 					const u8 *pos, const u8 *end)
228 {
229 	if (pos == NULL)
230 		return NULL;
231 
232 	if (end - pos < 2) {
233 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Too short GPSK-1 packet");
234 		return NULL;
235 	}
236 	*list_len = WPA_GET_BE16(pos);
237 	pos += 2;
238 	if (end - pos < (int) *list_len) {
239 		wpa_printf(MSG_DEBUG, "EAP-GPSK: CSuite_List overflow");
240 		return NULL;
241 	}
242 	if (*list_len == 0 || (*list_len % sizeof(struct eap_gpsk_csuite))) {
243 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Invalid CSuite_List len %lu",
244 			   (unsigned long) *list_len);
245 		return NULL;
246 	}
247 	*list = pos;
248 	pos += *list_len;
249 
250 	if (eap_gpsk_select_csuite(sm, data, *list, *list_len) < 0)
251 		return NULL;
252 
253 	return pos;
254 }
255 
256 
eap_gpsk_process_gpsk_1(struct eap_sm * sm,struct eap_gpsk_data * data,struct eap_method_ret * ret,const u8 * reqData,size_t reqDataLen,const u8 * payload,size_t payload_len,size_t * respDataLen)257 static u8 * eap_gpsk_process_gpsk_1(struct eap_sm *sm,
258 				    struct eap_gpsk_data *data,
259 				    struct eap_method_ret *ret,
260 				    const u8 *reqData, size_t reqDataLen,
261 				    const u8 *payload, size_t payload_len,
262 				    size_t *respDataLen)
263 {
264 	size_t csuite_list_len;
265 	const u8 *csuite_list, *pos, *end;
266 	const struct eap_hdr *req;
267 	u8 *resp;
268 
269 	if (data->state != GPSK_1) {
270 		ret->ignore = TRUE;
271 		return NULL;
272 	}
273 
274 	wpa_printf(MSG_DEBUG, "EAP-GPSK: Received Request/GPSK-1");
275 
276 	end = payload + payload_len;
277 
278 	pos = eap_gpsk_process_id_server(data, payload, end);
279 	pos = eap_gpsk_process_rand_server(data, pos, end);
280 	pos = eap_gpsk_process_csuite_list(sm, data, &csuite_list,
281 					   &csuite_list_len, pos, end);
282 	if (pos == NULL) {
283 		eap_gpsk_state(data, FAILURE);
284 		return NULL;
285 	}
286 
287 	req = (const struct eap_hdr *) reqData;
288 	resp = eap_gpsk_send_gpsk_2(data, req->identifier,
289 				    csuite_list, csuite_list_len,
290 				    respDataLen);
291 	if (resp == NULL)
292 		return NULL;
293 
294 	eap_gpsk_state(data, GPSK_3);
295 
296 	return (u8 *) resp;
297 }
298 
299 
eap_gpsk_send_gpsk_2(struct eap_gpsk_data * data,u8 identifier,const u8 * csuite_list,size_t csuite_list_len,size_t * respDataLen)300 static u8 * eap_gpsk_send_gpsk_2(struct eap_gpsk_data *data, u8 identifier,
301 				 const u8 *csuite_list, size_t csuite_list_len,
302 				 size_t *respDataLen)
303 {
304 	struct eap_hdr *resp;
305 	size_t len, miclen;
306 	u8 *rpos, *start;
307 	struct eap_gpsk_csuite *csuite;
308 
309 	wpa_printf(MSG_DEBUG, "EAP-GPSK: Sending Response/GPSK-2");
310 
311 	miclen = eap_gpsk_mic_len(data->vendor, data->specifier);
312 	len = 1 + 2 + data->id_peer_len + 2 + data->id_server_len +
313 		2 * EAP_GPSK_RAND_LEN + 2 + csuite_list_len +
314 		sizeof(struct eap_gpsk_csuite) + 2 + miclen;
315 
316 	resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_GPSK, respDataLen, len,
317 			     EAP_CODE_RESPONSE, identifier, &rpos);
318 	if (resp == NULL)
319 		return NULL;
320 
321 	*rpos++ = EAP_GPSK_OPCODE_GPSK_2;
322 	start = rpos;
323 
324 	wpa_hexdump_ascii(MSG_DEBUG, "EAP-GPSK: ID_Peer",
325 			  data->id_peer, data->id_peer_len);
326 	WPA_PUT_BE16(rpos, data->id_peer_len);
327 	rpos += 2;
328 	if (data->id_peer)
329 		os_memcpy(rpos, data->id_peer, data->id_peer_len);
330 	rpos += data->id_peer_len;
331 
332 	WPA_PUT_BE16(rpos, data->id_server_len);
333 	rpos += 2;
334 	if (data->id_server)
335 		os_memcpy(rpos, data->id_server, data->id_server_len);
336 	rpos += data->id_server_len;
337 
338 	if (os_get_random(data->rand_peer, EAP_GPSK_RAND_LEN)) {
339 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Failed to get random data "
340 			   "for RAND_Peer");
341 		eap_gpsk_state(data, FAILURE);
342 		os_free(resp);
343 		return NULL;
344 	}
345 	wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Peer",
346 		    data->rand_peer, EAP_GPSK_RAND_LEN);
347 	os_memcpy(rpos, data->rand_peer, EAP_GPSK_RAND_LEN);
348 	rpos += EAP_GPSK_RAND_LEN;
349 
350 	os_memcpy(rpos, data->rand_server, EAP_GPSK_RAND_LEN);
351 	rpos += EAP_GPSK_RAND_LEN;
352 
353 	WPA_PUT_BE16(rpos, csuite_list_len);
354 	rpos += 2;
355 	os_memcpy(rpos, csuite_list, csuite_list_len);
356 	rpos += csuite_list_len;
357 
358 	csuite = (struct eap_gpsk_csuite *) rpos;
359 	WPA_PUT_BE32(csuite->vendor, data->vendor);
360 	WPA_PUT_BE16(csuite->specifier, data->specifier);
361 	rpos = (u8 *) (csuite + 1);
362 
363 	if (eap_gpsk_derive_keys(data->psk, data->psk_len,
364 				 data->vendor, data->specifier,
365 				 data->rand_peer, data->rand_server,
366 				 data->id_peer, data->id_peer_len,
367 				 data->id_server, data->id_server_len,
368 				 data->msk, data->emsk,
369 				 data->sk, &data->sk_len,
370 				 data->pk, &data->pk_len) < 0) {
371 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Failed to derive keys");
372 		eap_gpsk_state(data, FAILURE);
373 		os_free(resp);
374 		return NULL;
375 	}
376 
377 	/* No PD_Payload_1 */
378 	WPA_PUT_BE16(rpos, 0);
379 	rpos += 2;
380 
381 	if (eap_gpsk_compute_mic(data->sk, data->sk_len, data->vendor,
382 				 data->specifier, start, rpos - start, rpos) <
383 	    0) {
384 		eap_gpsk_state(data, FAILURE);
385 		os_free(resp);
386 		return NULL;
387 	}
388 
389 	return (u8 *) resp;
390 }
391 
392 
eap_gpsk_validate_rand(struct eap_gpsk_data * data,const u8 * pos,const u8 * end)393 const u8 * eap_gpsk_validate_rand(struct eap_gpsk_data *data, const u8 *pos,
394 				  const u8 *end)
395 {
396 	if (end - pos < EAP_GPSK_RAND_LEN) {
397 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for "
398 			   "RAND_Peer");
399 		return NULL;
400 	}
401 	if (os_memcmp(pos, data->rand_peer, EAP_GPSK_RAND_LEN) != 0) {
402 		wpa_printf(MSG_DEBUG, "EAP-GPSK: RAND_Peer in GPSK-2 and "
403 			   "GPSK-3 did not match");
404 		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Peer in GPSK-2",
405 			    data->rand_peer, EAP_GPSK_RAND_LEN);
406 		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Peer in GPSK-3",
407 			    pos, EAP_GPSK_RAND_LEN);
408 		return NULL;
409 	}
410 	pos += EAP_GPSK_RAND_LEN;
411 
412 	if (end - pos < EAP_GPSK_RAND_LEN) {
413 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for "
414 			   "RAND_Server");
415 		return NULL;
416 	}
417 	if (os_memcmp(pos, data->rand_server, EAP_GPSK_RAND_LEN) != 0) {
418 		wpa_printf(MSG_DEBUG, "EAP-GPSK: RAND_Server in GPSK-1 and "
419 			   "GPSK-3 did not match");
420 		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Server in GPSK-1",
421 			    data->rand_server, EAP_GPSK_RAND_LEN);
422 		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: RAND_Server in GPSK-3",
423 			    pos, EAP_GPSK_RAND_LEN);
424 		return NULL;
425 	}
426 	pos += EAP_GPSK_RAND_LEN;
427 
428 	return pos;
429 }
430 
431 
eap_gpsk_validate_id_server(struct eap_gpsk_data * data,const u8 * pos,const u8 * end)432 const u8 * eap_gpsk_validate_id_server(struct eap_gpsk_data *data,
433 				       const u8 *pos, const u8 *end)
434 {
435 	size_t len;
436 
437 	if (pos == NULL)
438 		return NULL;
439 
440 	if (end - pos < (int) 2) {
441 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for "
442 			   "length(ID_Server)");
443 		return NULL;
444 	}
445 
446 	len = WPA_GET_BE16(pos);
447 	pos += 2;
448 
449 	if (end - pos < (int) len) {
450 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for "
451 			   "ID_Server");
452 		return NULL;
453 	}
454 
455 	if (len != data->id_server_len ||
456 	    os_memcmp(pos, data->id_server, len) != 0) {
457 		wpa_printf(MSG_INFO, "EAP-GPSK: ID_Server did not match with "
458 			   "the one used in GPSK-1");
459 		wpa_hexdump_ascii(MSG_DEBUG, "EAP-GPSK: ID_Server in GPSK-1",
460 				  data->id_server, data->id_server_len);
461 		wpa_hexdump_ascii(MSG_DEBUG, "EAP-GPSK: ID_Server in GPSK-3",
462 				  pos, len);
463 		return NULL;
464 	}
465 
466 	pos += len;
467 
468 	return pos;
469 }
470 
471 
eap_gpsk_validate_csuite(struct eap_gpsk_data * data,const u8 * pos,const u8 * end)472 const u8 * eap_gpsk_validate_csuite(struct eap_gpsk_data *data, const u8 *pos,
473 				    const u8 *end)
474 {
475 	int vendor, specifier;
476 	const struct eap_gpsk_csuite *csuite;
477 
478 	if (pos == NULL)
479 		return NULL;
480 
481 	if (end - pos < (int) sizeof(*csuite)) {
482 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for "
483 			   "CSuite_Sel");
484 		return NULL;
485 	}
486 	csuite = (const struct eap_gpsk_csuite *) pos;
487 	vendor = WPA_GET_BE32(csuite->vendor);
488 	specifier = WPA_GET_BE16(csuite->specifier);
489 	pos += sizeof(*csuite);
490 	if (vendor != data->vendor || specifier != data->specifier) {
491 		wpa_printf(MSG_DEBUG, "EAP-GPSK: CSuite_Sel (%d:%d) does not "
492 			   "match with the one sent in GPSK-2 (%d:%d)",
493 			   vendor, specifier, data->vendor, data->specifier);
494 		return NULL;
495 	}
496 
497 	return pos;
498 }
499 
500 
eap_gpsk_validate_pd_payload_2(struct eap_gpsk_data * data,const u8 * pos,const u8 * end)501 const u8 * eap_gpsk_validate_pd_payload_2(struct eap_gpsk_data *data,
502 					  const u8 *pos, const u8 *end)
503 {
504 	u16 alen;
505 
506 	if (pos == NULL)
507 		return NULL;
508 
509 	if (end - pos < 2) {
510 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for "
511 			   "PD_Payload_2 length");
512 		return NULL;
513 	}
514 	alen = WPA_GET_BE16(pos);
515 	pos += 2;
516 	if (end - pos < alen) {
517 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for "
518 			   "%d-octet PD_Payload_2", alen);
519 		return NULL;
520 	}
521 	wpa_hexdump(MSG_DEBUG, "EAP-GPSK: PD_Payload_2", pos, alen);
522 	pos += alen;
523 
524 	return pos;
525 }
526 
527 
eap_gpsk_validate_gpsk_3_mic(struct eap_gpsk_data * data,const u8 * payload,const u8 * pos,const u8 * end)528 const u8 * eap_gpsk_validate_gpsk_3_mic(struct eap_gpsk_data *data,
529 					const u8 *payload,
530 					const u8 *pos, const u8 *end)
531 {
532 	size_t miclen;
533 	u8 mic[EAP_GPSK_MAX_MIC_LEN];
534 
535 	if (pos == NULL)
536 		return NULL;
537 
538 	miclen = eap_gpsk_mic_len(data->vendor, data->specifier);
539 	if (end - pos < (int) miclen) {
540 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Message too short for MIC "
541 			   "(left=%lu miclen=%lu)",
542 			   (unsigned long) (end - pos),
543 			   (unsigned long) miclen);
544 		return NULL;
545 	}
546 	if (eap_gpsk_compute_mic(data->sk, data->sk_len, data->vendor,
547 				 data->specifier, payload, pos - payload, mic)
548 	    < 0) {
549 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Failed to compute MIC");
550 		return NULL;
551 	}
552 	if (os_memcmp(mic, pos, miclen) != 0) {
553 		wpa_printf(MSG_INFO, "EAP-GPSK: Incorrect MIC in GPSK-3");
554 		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Received MIC", pos, miclen);
555 		wpa_hexdump(MSG_DEBUG, "EAP-GPSK: Computed MIC", mic, miclen);
556 		return NULL;
557 	}
558 	pos += miclen;
559 
560 	return pos;
561 }
562 
563 
eap_gpsk_process_gpsk_3(struct eap_sm * sm,struct eap_gpsk_data * data,struct eap_method_ret * ret,const u8 * reqData,size_t reqDataLen,const u8 * payload,size_t payload_len,size_t * respDataLen)564 static u8 * eap_gpsk_process_gpsk_3(struct eap_sm *sm,
565 				    struct eap_gpsk_data *data,
566 				    struct eap_method_ret *ret,
567 				    const u8 *reqData, size_t reqDataLen,
568 				    const u8 *payload, size_t payload_len,
569 				    size_t *respDataLen)
570 {
571 	u8 *resp;
572 	const struct eap_hdr *req;
573 	const u8 *pos, *end;
574 
575 	if (data->state != GPSK_3) {
576 		ret->ignore = TRUE;
577 		return NULL;
578 	}
579 
580 	wpa_printf(MSG_DEBUG, "EAP-GPSK: Received Request/GPSK-3");
581 
582 	end = payload + payload_len;
583 
584 	pos = eap_gpsk_validate_rand(data, payload, end);
585 	pos = eap_gpsk_validate_id_server(data, pos, end);
586 	pos = eap_gpsk_validate_csuite(data, pos, end);
587 	pos = eap_gpsk_validate_pd_payload_2(data, pos, end);
588 	pos = eap_gpsk_validate_gpsk_3_mic(data, payload, pos, end);
589 
590 	if (pos == NULL) {
591 		eap_gpsk_state(data, FAILURE);
592 		return NULL;
593 	}
594 	if (pos != end) {
595 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Ignored %lu bytes of extra "
596 			   "data in the end of GPSK-2",
597 			   (unsigned long) (end - pos));
598 	}
599 
600 	req = (const struct eap_hdr *) reqData;
601 	resp = eap_gpsk_send_gpsk_4(data, req->identifier, respDataLen);
602 	if (resp == NULL)
603 		return NULL;
604 
605 	eap_gpsk_state(data, SUCCESS);
606 	ret->methodState = METHOD_DONE;
607 	ret->decision = DECISION_UNCOND_SUCC;
608 
609 	return (u8 *) resp;
610 }
611 
612 
eap_gpsk_send_gpsk_4(struct eap_gpsk_data * data,u8 identifier,size_t * respDataLen)613 static u8 * eap_gpsk_send_gpsk_4(struct eap_gpsk_data *data, u8 identifier,
614 				 size_t *respDataLen)
615 {
616 	struct eap_hdr *resp;
617 	u8 *rpos, *start;
618 	size_t len;
619 
620 	wpa_printf(MSG_DEBUG, "EAP-GPSK: Sending Response/GPSK-4");
621 
622 	len = 1 + 2 + eap_gpsk_mic_len(data->vendor, data->specifier);
623 
624 	resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_GPSK, respDataLen, len,
625 			     EAP_CODE_RESPONSE, identifier, &rpos);
626 	if (resp == NULL)
627 		return NULL;
628 
629 	*rpos++ = EAP_GPSK_OPCODE_GPSK_4;
630 	start = rpos;
631 
632 	/* No PD_Payload_3 */
633 	WPA_PUT_BE16(rpos, 0);
634 	rpos += 2;
635 
636 	if (eap_gpsk_compute_mic(data->sk, data->sk_len, data->vendor,
637 				 data->specifier, start, rpos - start, rpos) <
638 	    0) {
639 		eap_gpsk_state(data, FAILURE);
640 		os_free(resp);
641 		return NULL;
642 	}
643 
644 	return (u8 *) resp;
645 }
646 
647 
eap_gpsk_process(struct eap_sm * sm,void * priv,struct eap_method_ret * ret,const u8 * reqData,size_t reqDataLen,size_t * respDataLen)648 static u8 * eap_gpsk_process(struct eap_sm *sm, void *priv,
649 			    struct eap_method_ret *ret,
650 			    const u8 *reqData, size_t reqDataLen,
651 			    size_t *respDataLen)
652 {
653 	struct eap_gpsk_data *data = priv;
654 	u8 *resp;
655 	const u8 *pos;
656 	size_t len;
657 
658 	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_GPSK,
659 			       reqData, reqDataLen, &len);
660 	if (pos == NULL || len < 1) {
661 		ret->ignore = TRUE;
662 		return NULL;
663 	}
664 
665 	wpa_printf(MSG_DEBUG, "EAP-GPSK: Received frame: opcode %d", *pos);
666 
667 	ret->ignore = FALSE;
668 	ret->methodState = METHOD_MAY_CONT;
669 	ret->decision = DECISION_FAIL;
670 	ret->allowNotifications = FALSE;
671 
672 	switch (*pos) {
673 	case EAP_GPSK_OPCODE_GPSK_1:
674 		resp = eap_gpsk_process_gpsk_1(sm, data, ret, reqData,
675 					       reqDataLen, pos + 1, len - 1,
676 					       respDataLen);
677 		break;
678 	case EAP_GPSK_OPCODE_GPSK_3:
679 		resp = eap_gpsk_process_gpsk_3(sm, data, ret, reqData,
680 					       reqDataLen, pos + 1, len - 1,
681 					       respDataLen);
682 		break;
683 	default:
684 		wpa_printf(MSG_DEBUG, "EAP-GPSK: Ignoring message with "
685 			   "unknown opcode %d", *pos);
686 		ret->ignore = TRUE;
687 		return NULL;
688 	}
689 
690 	return resp;
691 }
692 
693 
eap_gpsk_isKeyAvailable(struct eap_sm * sm,void * priv)694 static Boolean eap_gpsk_isKeyAvailable(struct eap_sm *sm, void *priv)
695 {
696 	struct eap_gpsk_data *data = priv;
697 	return data->state == SUCCESS;
698 }
699 
700 
eap_gpsk_getKey(struct eap_sm * sm,void * priv,size_t * len)701 static u8 * eap_gpsk_getKey(struct eap_sm *sm, void *priv, size_t *len)
702 {
703 	struct eap_gpsk_data *data = priv;
704 	u8 *key;
705 
706 	if (data->state != SUCCESS)
707 		return NULL;
708 
709 	key = os_malloc(EAP_MSK_LEN);
710 	if (key == NULL)
711 		return NULL;
712 	os_memcpy(key, data->msk, EAP_MSK_LEN);
713 	*len = EAP_MSK_LEN;
714 
715 	return key;
716 }
717 
718 
eap_gpsk_get_emsk(struct eap_sm * sm,void * priv,size_t * len)719 static u8 * eap_gpsk_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
720 {
721 	struct eap_gpsk_data *data = priv;
722 	u8 *key;
723 
724 	if (data->state != SUCCESS)
725 		return NULL;
726 
727 	key = os_malloc(EAP_EMSK_LEN);
728 	if (key == NULL)
729 		return NULL;
730 	os_memcpy(key, data->emsk, EAP_EMSK_LEN);
731 	*len = EAP_EMSK_LEN;
732 
733 	return key;
734 }
735 
736 
eap_peer_gpsk_register(void)737 int eap_peer_gpsk_register(void)
738 {
739 	struct eap_method *eap;
740 	int ret;
741 
742 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
743 				    EAP_VENDOR_IETF, EAP_TYPE_GPSK, "GPSK");
744 	if (eap == NULL)
745 		return -1;
746 
747 	eap->init = eap_gpsk_init;
748 	eap->deinit = eap_gpsk_deinit;
749 	eap->process = eap_gpsk_process;
750 	eap->isKeyAvailable = eap_gpsk_isKeyAvailable;
751 	eap->getKey = eap_gpsk_getKey;
752 	eap->get_emsk = eap_gpsk_get_emsk;
753 
754 	ret = eap_peer_method_register(eap);
755 	if (ret)
756 		eap_peer_method_free(eap);
757 	return ret;
758 }
759