xref: /freebsd/contrib/wpa/src/eap_peer/ikev2.c (revision f8ea072a542112d5e0e74a2d6ecf75d967c3054c)
1 /*
2  * IKEv2 responder (RFC 4306) for EAP-IKEV2
3  * Copyright (c) 2007, 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/dh_groups.h"
13 #include "crypto/random.h"
14 #include "ikev2.h"
15 
16 
17 void ikev2_responder_deinit(struct ikev2_responder_data *data)
18 {
19 	ikev2_free_keys(&data->keys);
20 	wpabuf_free(data->i_dh_public);
21 	wpabuf_free(data->r_dh_private);
22 	os_free(data->IDi);
23 	os_free(data->IDr);
24 	os_free(data->shared_secret);
25 	wpabuf_free(data->i_sign_msg);
26 	wpabuf_free(data->r_sign_msg);
27 	os_free(data->key_pad);
28 }
29 
30 
31 static int ikev2_derive_keys(struct ikev2_responder_data *data)
32 {
33 	u8 *buf, *pos, *pad, skeyseed[IKEV2_MAX_HASH_LEN];
34 	size_t buf_len, pad_len;
35 	struct wpabuf *shared;
36 	const struct ikev2_integ_alg *integ;
37 	const struct ikev2_prf_alg *prf;
38 	const struct ikev2_encr_alg *encr;
39 	int ret;
40 	const u8 *addr[2];
41 	size_t len[2];
42 
43 	/* RFC 4306, Sect. 2.14 */
44 
45 	integ = ikev2_get_integ(data->proposal.integ);
46 	prf = ikev2_get_prf(data->proposal.prf);
47 	encr = ikev2_get_encr(data->proposal.encr);
48 	if (integ == NULL || prf == NULL || encr == NULL) {
49 		wpa_printf(MSG_INFO, "IKEV2: Unsupported proposal");
50 		return -1;
51 	}
52 
53 	shared = dh_derive_shared(data->i_dh_public, data->r_dh_private,
54 				  data->dh);
55 	if (shared == NULL)
56 		return -1;
57 
58 	/* Construct Ni | Nr | SPIi | SPIr */
59 
60 	buf_len = data->i_nonce_len + data->r_nonce_len + 2 * IKEV2_SPI_LEN;
61 	buf = os_malloc(buf_len);
62 	if (buf == NULL) {
63 		wpabuf_free(shared);
64 		return -1;
65 	}
66 
67 	pos = buf;
68 	os_memcpy(pos, data->i_nonce, data->i_nonce_len);
69 	pos += data->i_nonce_len;
70 	os_memcpy(pos, data->r_nonce, data->r_nonce_len);
71 	pos += data->r_nonce_len;
72 	os_memcpy(pos, data->i_spi, IKEV2_SPI_LEN);
73 	pos += IKEV2_SPI_LEN;
74 	os_memcpy(pos, data->r_spi, IKEV2_SPI_LEN);
75 #ifdef CCNS_PL
76 #if __BYTE_ORDER == __LITTLE_ENDIAN
77 	{
78 		int i;
79 		u8 *tmp = pos - IKEV2_SPI_LEN;
80 		/* Incorrect byte re-ordering on little endian hosts.. */
81 		for (i = 0; i < IKEV2_SPI_LEN; i++)
82 			*tmp++ = data->i_spi[IKEV2_SPI_LEN - 1 - i];
83 		for (i = 0; i < IKEV2_SPI_LEN; i++)
84 			*tmp++ = data->r_spi[IKEV2_SPI_LEN - 1 - i];
85 	}
86 #endif
87 #endif /* CCNS_PL */
88 
89 	/* SKEYSEED = prf(Ni | Nr, g^ir) */
90 	/* Use zero-padding per RFC 4306, Sect. 2.14 */
91 	pad_len = data->dh->prime_len - wpabuf_len(shared);
92 #ifdef CCNS_PL
93 	/* Shared secret is not zero-padded correctly */
94 	pad_len = 0;
95 #endif /* CCNS_PL */
96 	pad = os_zalloc(pad_len ? pad_len : 1);
97 	if (pad == NULL) {
98 		wpabuf_free(shared);
99 		os_free(buf);
100 		return -1;
101 	}
102 
103 	addr[0] = pad;
104 	len[0] = pad_len;
105 	addr[1] = wpabuf_head(shared);
106 	len[1] = wpabuf_len(shared);
107 	if (ikev2_prf_hash(prf->id, buf, data->i_nonce_len + data->r_nonce_len,
108 			   2, addr, len, skeyseed) < 0) {
109 		wpabuf_free(shared);
110 		os_free(buf);
111 		os_free(pad);
112 		return -1;
113 	}
114 	os_free(pad);
115 	wpabuf_free(shared);
116 
117 	/* DH parameters are not needed anymore, so free them */
118 	wpabuf_free(data->i_dh_public);
119 	data->i_dh_public = NULL;
120 	wpabuf_free(data->r_dh_private);
121 	data->r_dh_private = NULL;
122 
123 	wpa_hexdump_key(MSG_DEBUG, "IKEV2: SKEYSEED",
124 			skeyseed, prf->hash_len);
125 
126 	ret = ikev2_derive_sk_keys(prf, integ, encr, skeyseed, buf, buf_len,
127 				   &data->keys);
128 	os_free(buf);
129 	return ret;
130 }
131 
132 
133 static int ikev2_parse_transform(struct ikev2_proposal_data *prop,
134 				 const u8 *pos, const u8 *end)
135 {
136 	int transform_len;
137 	const struct ikev2_transform *t;
138 	u16 transform_id;
139 	const u8 *tend;
140 
141 	if (end - pos < (int) sizeof(*t)) {
142 		wpa_printf(MSG_INFO, "IKEV2: Too short transform");
143 		return -1;
144 	}
145 
146 	t = (const struct ikev2_transform *) pos;
147 	transform_len = WPA_GET_BE16(t->transform_length);
148 	if (transform_len < (int) sizeof(*t) || pos + transform_len > end) {
149 		wpa_printf(MSG_INFO, "IKEV2: Invalid transform length %d",
150 			   transform_len);
151 		return -1;
152 	}
153 	tend = pos + transform_len;
154 
155 	transform_id = WPA_GET_BE16(t->transform_id);
156 
157 	wpa_printf(MSG_DEBUG, "IKEV2:   Transform:");
158 	wpa_printf(MSG_DEBUG, "IKEV2:     Type: %d  Transform Length: %d  "
159 		   "Transform Type: %d  Transform ID: %d",
160 		   t->type, transform_len, t->transform_type, transform_id);
161 
162 	if (t->type != 0 && t->type != 3) {
163 		wpa_printf(MSG_INFO, "IKEV2: Unexpected Transform type");
164 		return -1;
165 	}
166 
167 	pos = (const u8 *) (t + 1);
168 	if (pos < tend) {
169 		wpa_hexdump(MSG_DEBUG, "IKEV2:     Transform Attributes",
170 			    pos, tend - pos);
171 	}
172 
173 	switch (t->transform_type) {
174 	case IKEV2_TRANSFORM_ENCR:
175 		if (ikev2_get_encr(transform_id)) {
176 			if (transform_id == ENCR_AES_CBC) {
177 				if (tend - pos != 4) {
178 					wpa_printf(MSG_DEBUG, "IKEV2: No "
179 						   "Transform Attr for AES");
180 					break;
181 				}
182 #ifdef CCNS_PL
183 				if (WPA_GET_BE16(pos) != 0x001d /* ?? */) {
184 					wpa_printf(MSG_DEBUG, "IKEV2: Not a "
185 						   "Key Size attribute for "
186 						   "AES");
187 					break;
188 				}
189 #else /* CCNS_PL */
190 				if (WPA_GET_BE16(pos) != 0x800e) {
191 					wpa_printf(MSG_DEBUG, "IKEV2: Not a "
192 						   "Key Size attribute for "
193 						   "AES");
194 					break;
195 				}
196 #endif /* CCNS_PL */
197 				if (WPA_GET_BE16(pos + 2) != 128) {
198 					wpa_printf(MSG_DEBUG, "IKEV2: "
199 						   "Unsupported AES key size "
200 						   "%d bits",
201 						   WPA_GET_BE16(pos + 2));
202 					break;
203 				}
204 			}
205 			prop->encr = transform_id;
206 		}
207 		break;
208 	case IKEV2_TRANSFORM_PRF:
209 		if (ikev2_get_prf(transform_id))
210 			prop->prf = transform_id;
211 		break;
212 	case IKEV2_TRANSFORM_INTEG:
213 		if (ikev2_get_integ(transform_id))
214 			prop->integ = transform_id;
215 		break;
216 	case IKEV2_TRANSFORM_DH:
217 		if (dh_groups_get(transform_id))
218 			prop->dh = transform_id;
219 		break;
220 	}
221 
222 	return transform_len;
223 }
224 
225 
226 static int ikev2_parse_proposal(struct ikev2_proposal_data *prop,
227 				const u8 *pos, const u8 *end)
228 {
229 	const u8 *pend, *ppos;
230 	int proposal_len, i;
231 	const struct ikev2_proposal *p;
232 
233 	if (end - pos < (int) sizeof(*p)) {
234 		wpa_printf(MSG_INFO, "IKEV2: Too short proposal");
235 		return -1;
236 	}
237 
238 	/* FIX: AND processing if multiple proposals use the same # */
239 
240 	p = (const struct ikev2_proposal *) pos;
241 	proposal_len = WPA_GET_BE16(p->proposal_length);
242 	if (proposal_len < (int) sizeof(*p) || pos + proposal_len > end) {
243 		wpa_printf(MSG_INFO, "IKEV2: Invalid proposal length %d",
244 			   proposal_len);
245 		return -1;
246 	}
247 	wpa_printf(MSG_DEBUG, "IKEV2: SAi1 Proposal # %d",
248 		   p->proposal_num);
249 	wpa_printf(MSG_DEBUG, "IKEV2:   Type: %d  Proposal Length: %d "
250 		   " Protocol ID: %d",
251 		   p->type, proposal_len, p->protocol_id);
252 	wpa_printf(MSG_DEBUG, "IKEV2:   SPI Size: %d  Transforms: %d",
253 		   p->spi_size, p->num_transforms);
254 
255 	if (p->type != 0 && p->type != 2) {
256 		wpa_printf(MSG_INFO, "IKEV2: Unexpected Proposal type");
257 		return -1;
258 	}
259 
260 	if (p->protocol_id != IKEV2_PROTOCOL_IKE) {
261 		wpa_printf(MSG_DEBUG, "IKEV2: Unexpected Protocol ID "
262 			   "(only IKE allowed for EAP-IKEv2)");
263 		return -1;
264 	}
265 
266 	if (p->proposal_num != prop->proposal_num) {
267 		if (p->proposal_num == prop->proposal_num + 1)
268 			prop->proposal_num = p->proposal_num;
269 		else {
270 			wpa_printf(MSG_INFO, "IKEV2: Unexpected Proposal #");
271 			return -1;
272 		}
273 	}
274 
275 	ppos = (const u8 *) (p + 1);
276 	pend = pos + proposal_len;
277 	if (ppos + p->spi_size > pend) {
278 		wpa_printf(MSG_INFO, "IKEV2: Not enough room for SPI "
279 			   "in proposal");
280 		return -1;
281 	}
282 	if (p->spi_size) {
283 		wpa_hexdump(MSG_DEBUG, "IKEV2:    SPI",
284 			    ppos, p->spi_size);
285 		ppos += p->spi_size;
286 	}
287 
288 	/*
289 	 * For initial IKE_SA negotiation, SPI Size MUST be zero; for
290 	 * subsequent negotiations, it must be 8 for IKE. We only support
291 	 * initial case for now.
292 	 */
293 	if (p->spi_size != 0) {
294 		wpa_printf(MSG_INFO, "IKEV2: Unexpected SPI Size");
295 		return -1;
296 	}
297 
298 	if (p->num_transforms == 0) {
299 		wpa_printf(MSG_INFO, "IKEV2: At least one transform required");
300 		return -1;
301 	}
302 
303 	for (i = 0; i < (int) p->num_transforms; i++) {
304 		int tlen = ikev2_parse_transform(prop, ppos, pend);
305 		if (tlen < 0)
306 			return -1;
307 		ppos += tlen;
308 	}
309 
310 	if (ppos != pend) {
311 		wpa_printf(MSG_INFO, "IKEV2: Unexpected data after "
312 			   "transforms");
313 		return -1;
314 	}
315 
316 	return proposal_len;
317 }
318 
319 
320 static int ikev2_process_sai1(struct ikev2_responder_data *data,
321 			      const u8 *sai1, size_t sai1_len)
322 {
323 	struct ikev2_proposal_data prop;
324 	const u8 *pos, *end;
325 	int found = 0;
326 
327 	/* Security Association Payloads: <Proposals> */
328 
329 	if (sai1 == NULL) {
330 		wpa_printf(MSG_INFO, "IKEV2: SAi1 not received");
331 		return -1;
332 	}
333 
334 	os_memset(&prop, 0, sizeof(prop));
335 	prop.proposal_num = 1;
336 
337 	pos = sai1;
338 	end = sai1 + sai1_len;
339 
340 	while (pos < end) {
341 		int plen;
342 
343 		prop.integ = -1;
344 		prop.prf = -1;
345 		prop.encr = -1;
346 		prop.dh = -1;
347 		plen = ikev2_parse_proposal(&prop, pos, end);
348 		if (plen < 0)
349 			return -1;
350 
351 		if (!found && prop.integ != -1 && prop.prf != -1 &&
352 		    prop.encr != -1 && prop.dh != -1) {
353 			os_memcpy(&data->proposal, &prop, sizeof(prop));
354 			data->dh = dh_groups_get(prop.dh);
355 			found = 1;
356 		}
357 
358 		pos += plen;
359 	}
360 
361 	if (pos != end) {
362 		wpa_printf(MSG_INFO, "IKEV2: Unexpected data after proposals");
363 		return -1;
364 	}
365 
366 	if (!found) {
367 		wpa_printf(MSG_INFO, "IKEV2: No acceptable proposal found");
368 		return -1;
369 	}
370 
371 	wpa_printf(MSG_DEBUG, "IKEV2: Accepted proposal #%d: ENCR:%d PRF:%d "
372 		   "INTEG:%d D-H:%d", data->proposal.proposal_num,
373 		   data->proposal.encr, data->proposal.prf,
374 		   data->proposal.integ, data->proposal.dh);
375 
376 	return 0;
377 }
378 
379 
380 static int ikev2_process_kei(struct ikev2_responder_data *data,
381 			     const u8 *kei, size_t kei_len)
382 {
383 	u16 group;
384 
385 	/*
386 	 * Key Exchange Payload:
387 	 * DH Group # (16 bits)
388 	 * RESERVED (16 bits)
389 	 * Key Exchange Data (Diffie-Hellman public value)
390 	 */
391 
392 	if (kei == NULL) {
393 		wpa_printf(MSG_INFO, "IKEV2: KEi not received");
394 		return -1;
395 	}
396 
397 	if (kei_len < 4 + 96) {
398 		wpa_printf(MSG_INFO, "IKEV2: Too show Key Exchange Payload");
399 		return -1;
400 	}
401 
402 	group = WPA_GET_BE16(kei);
403 	wpa_printf(MSG_DEBUG, "IKEV2: KEi DH Group #%u", group);
404 
405 	if (group != data->proposal.dh) {
406 		wpa_printf(MSG_DEBUG, "IKEV2: KEi DH Group #%u does not match "
407 			   "with the selected proposal (%u)",
408 			   group, data->proposal.dh);
409 		/* Reject message with Notify payload of type
410 		 * INVALID_KE_PAYLOAD (RFC 4306, Sect. 3.4) */
411 		data->error_type = INVALID_KE_PAYLOAD;
412 		data->state = NOTIFY;
413 		return -1;
414 	}
415 
416 	if (data->dh == NULL) {
417 		wpa_printf(MSG_INFO, "IKEV2: Unsupported DH group");
418 		return -1;
419 	}
420 
421 	/* RFC 4306, Section 3.4:
422 	 * The length of DH public value MUST be equal to the length of the
423 	 * prime modulus.
424 	 */
425 	if (kei_len - 4 != data->dh->prime_len) {
426 		wpa_printf(MSG_INFO, "IKEV2: Invalid DH public value length "
427 			   "%ld (expected %ld)",
428 			   (long) (kei_len - 4), (long) data->dh->prime_len);
429 		return -1;
430 	}
431 
432 	wpabuf_free(data->i_dh_public);
433 	data->i_dh_public = wpabuf_alloc(kei_len - 4);
434 	if (data->i_dh_public == NULL)
435 		return -1;
436 	wpabuf_put_data(data->i_dh_public, kei + 4, kei_len - 4);
437 
438 	wpa_hexdump_buf(MSG_DEBUG, "IKEV2: KEi Diffie-Hellman Public Value",
439 			data->i_dh_public);
440 
441 	return 0;
442 }
443 
444 
445 static int ikev2_process_ni(struct ikev2_responder_data *data,
446 			    const u8 *ni, size_t ni_len)
447 {
448 	if (ni == NULL) {
449 		wpa_printf(MSG_INFO, "IKEV2: Ni not received");
450 		return -1;
451 	}
452 
453 	if (ni_len < IKEV2_NONCE_MIN_LEN || ni_len > IKEV2_NONCE_MAX_LEN) {
454 		wpa_printf(MSG_INFO, "IKEV2: Invalid Ni length %ld",
455 		           (long) ni_len);
456 		return -1;
457 	}
458 
459 #ifdef CCNS_PL
460 	/* Zeros are removed incorrectly from the beginning of the nonces */
461 	while (ni_len > 1 && *ni == 0) {
462 		ni_len--;
463 		ni++;
464 	}
465 #endif /* CCNS_PL */
466 
467 	data->i_nonce_len = ni_len;
468 	os_memcpy(data->i_nonce, ni, ni_len);
469 	wpa_hexdump(MSG_MSGDUMP, "IKEV2: Ni",
470 		    data->i_nonce, data->i_nonce_len);
471 
472 	return 0;
473 }
474 
475 
476 static int ikev2_process_sa_init(struct ikev2_responder_data *data,
477 				 const struct ikev2_hdr *hdr,
478 				 struct ikev2_payloads *pl)
479 {
480 	if (ikev2_process_sai1(data, pl->sa, pl->sa_len) < 0 ||
481 	    ikev2_process_kei(data, pl->ke, pl->ke_len) < 0 ||
482 	    ikev2_process_ni(data, pl->nonce, pl->nonce_len) < 0)
483 		return -1;
484 
485 	os_memcpy(data->i_spi, hdr->i_spi, IKEV2_SPI_LEN);
486 
487 	return 0;
488 }
489 
490 
491 static int ikev2_process_idi(struct ikev2_responder_data *data,
492 			     const u8 *idi, size_t idi_len)
493 {
494 	u8 id_type;
495 
496 	if (idi == NULL) {
497 		wpa_printf(MSG_INFO, "IKEV2: No IDi received");
498 		return -1;
499 	}
500 
501 	if (idi_len < 4) {
502 		wpa_printf(MSG_INFO, "IKEV2: Too short IDi payload");
503 		return -1;
504 	}
505 
506 	id_type = idi[0];
507 	idi += 4;
508 	idi_len -= 4;
509 
510 	wpa_printf(MSG_DEBUG, "IKEV2: IDi ID Type %d", id_type);
511 	wpa_hexdump_ascii(MSG_DEBUG, "IKEV2: IDi", idi, idi_len);
512 	os_free(data->IDi);
513 	data->IDi = os_malloc(idi_len);
514 	if (data->IDi == NULL)
515 		return -1;
516 	os_memcpy(data->IDi, idi, idi_len);
517 	data->IDi_len = idi_len;
518 	data->IDi_type = id_type;
519 
520 	return 0;
521 }
522 
523 
524 static int ikev2_process_cert(struct ikev2_responder_data *data,
525 			      const u8 *cert, size_t cert_len)
526 {
527 	u8 cert_encoding;
528 
529 	if (cert == NULL) {
530 		if (data->peer_auth == PEER_AUTH_CERT) {
531 			wpa_printf(MSG_INFO, "IKEV2: No Certificate received");
532 			return -1;
533 		}
534 		return 0;
535 	}
536 
537 	if (cert_len < 1) {
538 		wpa_printf(MSG_INFO, "IKEV2: No Cert Encoding field");
539 		return -1;
540 	}
541 
542 	cert_encoding = cert[0];
543 	cert++;
544 	cert_len--;
545 
546 	wpa_printf(MSG_DEBUG, "IKEV2: Cert Encoding %d", cert_encoding);
547 	wpa_hexdump(MSG_MSGDUMP, "IKEV2: Certificate Data", cert, cert_len);
548 
549 	/* TODO: validate certificate */
550 
551 	return 0;
552 }
553 
554 
555 static int ikev2_process_auth_cert(struct ikev2_responder_data *data,
556 				   u8 method, const u8 *auth, size_t auth_len)
557 {
558 	if (method != AUTH_RSA_SIGN) {
559 		wpa_printf(MSG_INFO, "IKEV2: Unsupported authentication "
560 			   "method %d", method);
561 		return -1;
562 	}
563 
564 	/* TODO: validate AUTH */
565 	return 0;
566 }
567 
568 
569 static int ikev2_process_auth_secret(struct ikev2_responder_data *data,
570 				     u8 method, const u8 *auth,
571 				     size_t auth_len)
572 {
573 	u8 auth_data[IKEV2_MAX_HASH_LEN];
574 	const struct ikev2_prf_alg *prf;
575 
576 	if (method != AUTH_SHARED_KEY_MIC) {
577 		wpa_printf(MSG_INFO, "IKEV2: Unsupported authentication "
578 			   "method %d", method);
579 		return -1;
580 	}
581 
582 	/* msg | Nr | prf(SK_pi,IDi') */
583 	if (ikev2_derive_auth_data(data->proposal.prf, data->i_sign_msg,
584 				   data->IDi, data->IDi_len, data->IDi_type,
585 				   &data->keys, 1, data->shared_secret,
586 				   data->shared_secret_len,
587 				   data->r_nonce, data->r_nonce_len,
588 				   data->key_pad, data->key_pad_len,
589 				   auth_data) < 0) {
590 		wpa_printf(MSG_INFO, "IKEV2: Could not derive AUTH data");
591 		return -1;
592 	}
593 
594 	wpabuf_free(data->i_sign_msg);
595 	data->i_sign_msg = NULL;
596 
597 	prf = ikev2_get_prf(data->proposal.prf);
598 	if (prf == NULL)
599 		return -1;
600 
601 	if (auth_len != prf->hash_len ||
602 	    os_memcmp(auth, auth_data, auth_len) != 0) {
603 		wpa_printf(MSG_INFO, "IKEV2: Invalid Authentication Data");
604 		wpa_hexdump(MSG_DEBUG, "IKEV2: Received Authentication Data",
605 			    auth, auth_len);
606 		wpa_hexdump(MSG_DEBUG, "IKEV2: Expected Authentication Data",
607 			    auth_data, prf->hash_len);
608 		data->error_type = AUTHENTICATION_FAILED;
609 		data->state = NOTIFY;
610 		return -1;
611 	}
612 
613 	wpa_printf(MSG_DEBUG, "IKEV2: Server authenticated successfully "
614 		   "using shared keys");
615 
616 	return 0;
617 }
618 
619 
620 static int ikev2_process_auth(struct ikev2_responder_data *data,
621 			      const u8 *auth, size_t auth_len)
622 {
623 	u8 auth_method;
624 
625 	if (auth == NULL) {
626 		wpa_printf(MSG_INFO, "IKEV2: No Authentication Payload");
627 		return -1;
628 	}
629 
630 	if (auth_len < 4) {
631 		wpa_printf(MSG_INFO, "IKEV2: Too short Authentication "
632 			   "Payload");
633 		return -1;
634 	}
635 
636 	auth_method = auth[0];
637 	auth += 4;
638 	auth_len -= 4;
639 
640 	wpa_printf(MSG_DEBUG, "IKEV2: Auth Method %d", auth_method);
641 	wpa_hexdump(MSG_MSGDUMP, "IKEV2: Authentication Data", auth, auth_len);
642 
643 	switch (data->peer_auth) {
644 	case PEER_AUTH_CERT:
645 		return ikev2_process_auth_cert(data, auth_method, auth,
646 					       auth_len);
647 	case PEER_AUTH_SECRET:
648 		return ikev2_process_auth_secret(data, auth_method, auth,
649 						 auth_len);
650 	}
651 
652 	return -1;
653 }
654 
655 
656 static int ikev2_process_sa_auth_decrypted(struct ikev2_responder_data *data,
657 					   u8 next_payload,
658 					   u8 *payload, size_t payload_len)
659 {
660 	struct ikev2_payloads pl;
661 
662 	wpa_printf(MSG_DEBUG, "IKEV2: Processing decrypted payloads");
663 
664 	if (ikev2_parse_payloads(&pl, next_payload, payload, payload +
665 				 payload_len) < 0) {
666 		wpa_printf(MSG_INFO, "IKEV2: Failed to parse decrypted "
667 			   "payloads");
668 		return -1;
669 	}
670 
671 	if (ikev2_process_idi(data, pl.idi, pl.idi_len) < 0 ||
672 	    ikev2_process_cert(data, pl.cert, pl.cert_len) < 0 ||
673 	    ikev2_process_auth(data, pl.auth, pl.auth_len) < 0)
674 		return -1;
675 
676 	return 0;
677 }
678 
679 
680 static int ikev2_process_sa_auth(struct ikev2_responder_data *data,
681 				 const struct ikev2_hdr *hdr,
682 				 struct ikev2_payloads *pl)
683 {
684 	u8 *decrypted;
685 	size_t decrypted_len;
686 	int ret;
687 
688 	decrypted = ikev2_decrypt_payload(data->proposal.encr,
689 					  data->proposal.integ,
690 					  &data->keys, 1, hdr, pl->encrypted,
691 					  pl->encrypted_len, &decrypted_len);
692 	if (decrypted == NULL)
693 		return -1;
694 
695 	ret = ikev2_process_sa_auth_decrypted(data, pl->encr_next_payload,
696 					      decrypted, decrypted_len);
697 	os_free(decrypted);
698 
699 	return ret;
700 }
701 
702 
703 static int ikev2_validate_rx_state(struct ikev2_responder_data *data,
704 				   u8 exchange_type, u32 message_id)
705 {
706 	switch (data->state) {
707 	case SA_INIT:
708 		/* Expect to receive IKE_SA_INIT: HDR, SAi1, KEi, Ni */
709 		if (exchange_type != IKE_SA_INIT) {
710 			wpa_printf(MSG_INFO, "IKEV2: Unexpected Exchange Type "
711 				   "%u in SA_INIT state", exchange_type);
712 			return -1;
713 		}
714 		if (message_id != 0) {
715 			wpa_printf(MSG_INFO, "IKEV2: Unexpected Message ID %u "
716 				   "in SA_INIT state", message_id);
717 			return -1;
718 		}
719 		break;
720 	case SA_AUTH:
721 		/* Expect to receive IKE_SA_AUTH:
722 		 * HDR, SK {IDi, [CERT,] [CERTREQ,] [IDr,]
723 		 *	AUTH, SAi2, TSi, TSr}
724 		 */
725 		if (exchange_type != IKE_SA_AUTH) {
726 			wpa_printf(MSG_INFO, "IKEV2: Unexpected Exchange Type "
727 				   "%u in SA_AUTH state", exchange_type);
728 			return -1;
729 		}
730 		if (message_id != 1) {
731 			wpa_printf(MSG_INFO, "IKEV2: Unexpected Message ID %u "
732 				   "in SA_AUTH state", message_id);
733 			return -1;
734 		}
735 		break;
736 	case CHILD_SA:
737 		if (exchange_type != CREATE_CHILD_SA) {
738 			wpa_printf(MSG_INFO, "IKEV2: Unexpected Exchange Type "
739 				   "%u in CHILD_SA state", exchange_type);
740 			return -1;
741 		}
742 		if (message_id != 2) {
743 			wpa_printf(MSG_INFO, "IKEV2: Unexpected Message ID %u "
744 				   "in CHILD_SA state", message_id);
745 			return -1;
746 		}
747 		break;
748 	case NOTIFY:
749 	case IKEV2_DONE:
750 	case IKEV2_FAILED:
751 		return -1;
752 	}
753 
754 	return 0;
755 }
756 
757 
758 int ikev2_responder_process(struct ikev2_responder_data *data,
759 			    const struct wpabuf *buf)
760 {
761 	const struct ikev2_hdr *hdr;
762 	u32 length, message_id;
763 	const u8 *pos, *end;
764 	struct ikev2_payloads pl;
765 
766 	wpa_printf(MSG_MSGDUMP, "IKEV2: Received message (len %lu)",
767 		   (unsigned long) wpabuf_len(buf));
768 
769 	if (wpabuf_len(buf) < sizeof(*hdr)) {
770 		wpa_printf(MSG_INFO, "IKEV2: Too short frame to include HDR");
771 		return -1;
772 	}
773 
774 	data->error_type = 0;
775 	hdr = (const struct ikev2_hdr *) wpabuf_head(buf);
776 	end = wpabuf_head_u8(buf) + wpabuf_len(buf);
777 	message_id = WPA_GET_BE32(hdr->message_id);
778 	length = WPA_GET_BE32(hdr->length);
779 
780 	wpa_hexdump(MSG_DEBUG, "IKEV2:   IKE_SA Initiator's SPI",
781 		    hdr->i_spi, IKEV2_SPI_LEN);
782 	wpa_hexdump(MSG_DEBUG, "IKEV2:   IKE_SA Responder's SPI",
783 		    hdr->r_spi, IKEV2_SPI_LEN);
784 	wpa_printf(MSG_DEBUG, "IKEV2:   Next Payload: %u  Version: 0x%x  "
785 		   "Exchange Type: %u",
786 		   hdr->next_payload, hdr->version, hdr->exchange_type);
787 	wpa_printf(MSG_DEBUG, "IKEV2:   Message ID: %u  Length: %u",
788 		   message_id, length);
789 
790 	if (hdr->version != IKEV2_VERSION) {
791 		wpa_printf(MSG_INFO, "IKEV2: Unsupported HDR version 0x%x "
792 			   "(expected 0x%x)", hdr->version, IKEV2_VERSION);
793 		return -1;
794 	}
795 
796 	if (length != wpabuf_len(buf)) {
797 		wpa_printf(MSG_INFO, "IKEV2: Invalid length (HDR: %lu != "
798 			   "RX: %lu)", (unsigned long) length,
799 			   (unsigned long) wpabuf_len(buf));
800 		return -1;
801 	}
802 
803 	if (ikev2_validate_rx_state(data, hdr->exchange_type, message_id) < 0)
804 		return -1;
805 
806 	if ((hdr->flags & (IKEV2_HDR_INITIATOR | IKEV2_HDR_RESPONSE)) !=
807 	    IKEV2_HDR_INITIATOR) {
808 		wpa_printf(MSG_INFO, "IKEV2: Unexpected Flags value 0x%x",
809 			   hdr->flags);
810 		return -1;
811 	}
812 
813 	if (data->state != SA_INIT) {
814 		if (os_memcmp(data->i_spi, hdr->i_spi, IKEV2_SPI_LEN) != 0) {
815 			wpa_printf(MSG_INFO, "IKEV2: Unexpected IKE_SA "
816 				   "Initiator's SPI");
817 			return -1;
818 		}
819 		if (os_memcmp(data->r_spi, hdr->r_spi, IKEV2_SPI_LEN) != 0) {
820 			wpa_printf(MSG_INFO, "IKEV2: Unexpected IKE_SA "
821 				   "Responder's SPI");
822 			return -1;
823 		}
824 	}
825 
826 	pos = (const u8 *) (hdr + 1);
827 	if (ikev2_parse_payloads(&pl, hdr->next_payload, pos, end) < 0)
828 		return -1;
829 
830 	if (data->state == SA_INIT) {
831 		data->last_msg = LAST_MSG_SA_INIT;
832 		if (ikev2_process_sa_init(data, hdr, &pl) < 0) {
833 			if (data->state == NOTIFY)
834 				return 0;
835 			return -1;
836 		}
837 		wpabuf_free(data->i_sign_msg);
838 		data->i_sign_msg = wpabuf_dup(buf);
839 	}
840 
841 	if (data->state == SA_AUTH) {
842 		data->last_msg = LAST_MSG_SA_AUTH;
843 		if (ikev2_process_sa_auth(data, hdr, &pl) < 0) {
844 			if (data->state == NOTIFY)
845 				return 0;
846 			return -1;
847 		}
848 	}
849 
850 	return 0;
851 }
852 
853 
854 static void ikev2_build_hdr(struct ikev2_responder_data *data,
855 			    struct wpabuf *msg, u8 exchange_type,
856 			    u8 next_payload, u32 message_id)
857 {
858 	struct ikev2_hdr *hdr;
859 
860 	wpa_printf(MSG_DEBUG, "IKEV2: Adding HDR");
861 
862 	/* HDR - RFC 4306, Sect. 3.1 */
863 	hdr = wpabuf_put(msg, sizeof(*hdr));
864 	os_memcpy(hdr->i_spi, data->i_spi, IKEV2_SPI_LEN);
865 	os_memcpy(hdr->r_spi, data->r_spi, IKEV2_SPI_LEN);
866 	hdr->next_payload = next_payload;
867 	hdr->version = IKEV2_VERSION;
868 	hdr->exchange_type = exchange_type;
869 	hdr->flags = IKEV2_HDR_RESPONSE;
870 	WPA_PUT_BE32(hdr->message_id, message_id);
871 }
872 
873 
874 static int ikev2_build_sar1(struct ikev2_responder_data *data,
875 			    struct wpabuf *msg, u8 next_payload)
876 {
877 	struct ikev2_payload_hdr *phdr;
878 	size_t plen;
879 	struct ikev2_proposal *p;
880 	struct ikev2_transform *t;
881 
882 	wpa_printf(MSG_DEBUG, "IKEV2: Adding SAr1 payload");
883 
884 	/* SAr1 - RFC 4306, Sect. 2.7 and 3.3 */
885 	phdr = wpabuf_put(msg, sizeof(*phdr));
886 	phdr->next_payload = next_payload;
887 	phdr->flags = 0;
888 
889 	p = wpabuf_put(msg, sizeof(*p));
890 #ifdef CCNS_PL
891 	/* Seems to require that the Proposal # is 1 even though RFC 4306
892 	 * Sect 3.3.1 has following requirement "When a proposal is accepted,
893 	 * all of the proposal numbers in the SA payload MUST be the same and
894 	 * MUST match the number on the proposal sent that was accepted.".
895 	 */
896 	p->proposal_num = 1;
897 #else /* CCNS_PL */
898 	p->proposal_num = data->proposal.proposal_num;
899 #endif /* CCNS_PL */
900 	p->protocol_id = IKEV2_PROTOCOL_IKE;
901 	p->num_transforms = 4;
902 
903 	t = wpabuf_put(msg, sizeof(*t));
904 	t->type = 3;
905 	t->transform_type = IKEV2_TRANSFORM_ENCR;
906 	WPA_PUT_BE16(t->transform_id, data->proposal.encr);
907 	if (data->proposal.encr == ENCR_AES_CBC) {
908 		/* Transform Attribute: Key Len = 128 bits */
909 #ifdef CCNS_PL
910 		wpabuf_put_be16(msg, 0x001d); /* ?? */
911 #else /* CCNS_PL */
912 		wpabuf_put_be16(msg, 0x800e); /* AF=1, AttrType=14 */
913 #endif /* CCNS_PL */
914 		wpabuf_put_be16(msg, 128); /* 128-bit key */
915 	}
916 	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) t;
917 	WPA_PUT_BE16(t->transform_length, plen);
918 
919 	t = wpabuf_put(msg, sizeof(*t));
920 	t->type = 3;
921 	WPA_PUT_BE16(t->transform_length, sizeof(*t));
922 	t->transform_type = IKEV2_TRANSFORM_PRF;
923 	WPA_PUT_BE16(t->transform_id, data->proposal.prf);
924 
925 	t = wpabuf_put(msg, sizeof(*t));
926 	t->type = 3;
927 	WPA_PUT_BE16(t->transform_length, sizeof(*t));
928 	t->transform_type = IKEV2_TRANSFORM_INTEG;
929 	WPA_PUT_BE16(t->transform_id, data->proposal.integ);
930 
931 	t = wpabuf_put(msg, sizeof(*t));
932 	WPA_PUT_BE16(t->transform_length, sizeof(*t));
933 	t->transform_type = IKEV2_TRANSFORM_DH;
934 	WPA_PUT_BE16(t->transform_id, data->proposal.dh);
935 
936 	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) p;
937 	WPA_PUT_BE16(p->proposal_length, plen);
938 
939 	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
940 	WPA_PUT_BE16(phdr->payload_length, plen);
941 
942 	return 0;
943 }
944 
945 
946 static int ikev2_build_ker(struct ikev2_responder_data *data,
947 			   struct wpabuf *msg, u8 next_payload)
948 {
949 	struct ikev2_payload_hdr *phdr;
950 	size_t plen;
951 	struct wpabuf *pv;
952 
953 	wpa_printf(MSG_DEBUG, "IKEV2: Adding KEr payload");
954 
955 	pv = dh_init(data->dh, &data->r_dh_private);
956 	if (pv == NULL) {
957 		wpa_printf(MSG_DEBUG, "IKEV2: Failed to initialize DH");
958 		return -1;
959 	}
960 
961 	/* KEr - RFC 4306, Sect. 3.4 */
962 	phdr = wpabuf_put(msg, sizeof(*phdr));
963 	phdr->next_payload = next_payload;
964 	phdr->flags = 0;
965 
966 	wpabuf_put_be16(msg, data->proposal.dh); /* DH Group # */
967 	wpabuf_put(msg, 2); /* RESERVED */
968 	/*
969 	 * RFC 4306, Sect. 3.4: possible zero padding for public value to
970 	 * match the length of the prime.
971 	 */
972 	wpabuf_put(msg, data->dh->prime_len - wpabuf_len(pv));
973 	wpabuf_put_buf(msg, pv);
974 	wpabuf_free(pv);
975 
976 	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
977 	WPA_PUT_BE16(phdr->payload_length, plen);
978 	return 0;
979 }
980 
981 
982 static int ikev2_build_nr(struct ikev2_responder_data *data,
983 			  struct wpabuf *msg, u8 next_payload)
984 {
985 	struct ikev2_payload_hdr *phdr;
986 	size_t plen;
987 
988 	wpa_printf(MSG_DEBUG, "IKEV2: Adding Nr payload");
989 
990 	/* Nr - RFC 4306, Sect. 3.9 */
991 	phdr = wpabuf_put(msg, sizeof(*phdr));
992 	phdr->next_payload = next_payload;
993 	phdr->flags = 0;
994 	wpabuf_put_data(msg, data->r_nonce, data->r_nonce_len);
995 	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
996 	WPA_PUT_BE16(phdr->payload_length, plen);
997 	return 0;
998 }
999 
1000 
1001 static int ikev2_build_idr(struct ikev2_responder_data *data,
1002 			   struct wpabuf *msg, u8 next_payload)
1003 {
1004 	struct ikev2_payload_hdr *phdr;
1005 	size_t plen;
1006 
1007 	wpa_printf(MSG_DEBUG, "IKEV2: Adding IDr payload");
1008 
1009 	if (data->IDr == NULL) {
1010 		wpa_printf(MSG_INFO, "IKEV2: No IDr available");
1011 		return -1;
1012 	}
1013 
1014 	/* IDr - RFC 4306, Sect. 3.5 */
1015 	phdr = wpabuf_put(msg, sizeof(*phdr));
1016 	phdr->next_payload = next_payload;
1017 	phdr->flags = 0;
1018 	wpabuf_put_u8(msg, ID_KEY_ID);
1019 	wpabuf_put(msg, 3); /* RESERVED */
1020 	wpabuf_put_data(msg, data->IDr, data->IDr_len);
1021 	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
1022 	WPA_PUT_BE16(phdr->payload_length, plen);
1023 	return 0;
1024 }
1025 
1026 
1027 static int ikev2_build_auth(struct ikev2_responder_data *data,
1028 			    struct wpabuf *msg, u8 next_payload)
1029 {
1030 	struct ikev2_payload_hdr *phdr;
1031 	size_t plen;
1032 	const struct ikev2_prf_alg *prf;
1033 
1034 	wpa_printf(MSG_DEBUG, "IKEV2: Adding AUTH payload");
1035 
1036 	prf = ikev2_get_prf(data->proposal.prf);
1037 	if (prf == NULL)
1038 		return -1;
1039 
1040 	/* Authentication - RFC 4306, Sect. 3.8 */
1041 	phdr = wpabuf_put(msg, sizeof(*phdr));
1042 	phdr->next_payload = next_payload;
1043 	phdr->flags = 0;
1044 	wpabuf_put_u8(msg, AUTH_SHARED_KEY_MIC);
1045 	wpabuf_put(msg, 3); /* RESERVED */
1046 
1047 	/* msg | Ni | prf(SK_pr,IDr') */
1048 	if (ikev2_derive_auth_data(data->proposal.prf, data->r_sign_msg,
1049 				   data->IDr, data->IDr_len, ID_KEY_ID,
1050 				   &data->keys, 0, data->shared_secret,
1051 				   data->shared_secret_len,
1052 				   data->i_nonce, data->i_nonce_len,
1053 				   data->key_pad, data->key_pad_len,
1054 				   wpabuf_put(msg, prf->hash_len)) < 0) {
1055 		wpa_printf(MSG_INFO, "IKEV2: Could not derive AUTH data");
1056 		return -1;
1057 	}
1058 	wpabuf_free(data->r_sign_msg);
1059 	data->r_sign_msg = NULL;
1060 
1061 	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
1062 	WPA_PUT_BE16(phdr->payload_length, plen);
1063 	return 0;
1064 }
1065 
1066 
1067 static int ikev2_build_notification(struct ikev2_responder_data *data,
1068 				    struct wpabuf *msg, u8 next_payload)
1069 {
1070 	struct ikev2_payload_hdr *phdr;
1071 	size_t plen;
1072 
1073 	wpa_printf(MSG_DEBUG, "IKEV2: Adding Notification payload");
1074 
1075 	if (data->error_type == 0) {
1076 		wpa_printf(MSG_INFO, "IKEV2: No Notify Message Type "
1077 			   "available");
1078 		return -1;
1079 	}
1080 
1081 	/* Notify - RFC 4306, Sect. 3.10 */
1082 	phdr = wpabuf_put(msg, sizeof(*phdr));
1083 	phdr->next_payload = next_payload;
1084 	phdr->flags = 0;
1085 #ifdef CCNS_PL
1086 	wpabuf_put_u8(msg, 1); /* Protocol ID: IKE_SA notification */
1087 #else /* CCNS_PL */
1088 	wpabuf_put_u8(msg, 0); /* Protocol ID: no existing SA */
1089 #endif /* CCNS_PL */
1090 	wpabuf_put_u8(msg, 0); /* SPI Size */
1091 	wpabuf_put_be16(msg, data->error_type);
1092 
1093 	switch (data->error_type) {
1094 	case INVALID_KE_PAYLOAD:
1095 		if (data->proposal.dh == -1) {
1096 			wpa_printf(MSG_INFO, "IKEV2: No DH Group selected for "
1097 				   "INVALID_KE_PAYLOAD notifications");
1098 			return -1;
1099 		}
1100 		wpabuf_put_be16(msg, data->proposal.dh);
1101 		wpa_printf(MSG_DEBUG, "IKEV2: INVALID_KE_PAYLOAD - request "
1102 			   "DH Group #%d", data->proposal.dh);
1103 		break;
1104 	case AUTHENTICATION_FAILED:
1105 		/* no associated data */
1106 		break;
1107 	default:
1108 		wpa_printf(MSG_INFO, "IKEV2: Unsupported Notify Message Type "
1109 			   "%d", data->error_type);
1110 		return -1;
1111 	}
1112 
1113 	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
1114 	WPA_PUT_BE16(phdr->payload_length, plen);
1115 	return 0;
1116 }
1117 
1118 
1119 static struct wpabuf * ikev2_build_sa_init(struct ikev2_responder_data *data)
1120 {
1121 	struct wpabuf *msg;
1122 
1123 	/* build IKE_SA_INIT: HDR, SAr1, KEr, Nr, [CERTREQ], [SK{IDr}] */
1124 
1125 	if (os_get_random(data->r_spi, IKEV2_SPI_LEN))
1126 		return NULL;
1127 	wpa_hexdump(MSG_DEBUG, "IKEV2: IKE_SA Responder's SPI",
1128 		    data->r_spi, IKEV2_SPI_LEN);
1129 
1130 	data->r_nonce_len = IKEV2_NONCE_MIN_LEN;
1131 	if (random_get_bytes(data->r_nonce, data->r_nonce_len))
1132 		return NULL;
1133 #ifdef CCNS_PL
1134 	/* Zeros are removed incorrectly from the beginning of the nonces in
1135 	 * key derivation; as a workaround, make sure Nr does not start with
1136 	 * zero.. */
1137 	if (data->r_nonce[0] == 0)
1138 		data->r_nonce[0] = 1;
1139 #endif /* CCNS_PL */
1140 	wpa_hexdump(MSG_DEBUG, "IKEV2: Nr", data->r_nonce, data->r_nonce_len);
1141 
1142 	msg = wpabuf_alloc(sizeof(struct ikev2_hdr) + data->IDr_len + 1500);
1143 	if (msg == NULL)
1144 		return NULL;
1145 
1146 	ikev2_build_hdr(data, msg, IKE_SA_INIT, IKEV2_PAYLOAD_SA, 0);
1147 	if (ikev2_build_sar1(data, msg, IKEV2_PAYLOAD_KEY_EXCHANGE) ||
1148 	    ikev2_build_ker(data, msg, IKEV2_PAYLOAD_NONCE) ||
1149 	    ikev2_build_nr(data, msg, data->peer_auth == PEER_AUTH_SECRET ?
1150 			   IKEV2_PAYLOAD_ENCRYPTED :
1151 			   IKEV2_PAYLOAD_NO_NEXT_PAYLOAD)) {
1152 		wpabuf_free(msg);
1153 		return NULL;
1154 	}
1155 
1156 	if (ikev2_derive_keys(data)) {
1157 		wpabuf_free(msg);
1158 		return NULL;
1159 	}
1160 
1161 	if (data->peer_auth == PEER_AUTH_CERT) {
1162 		/* TODO: CERTREQ with SHA-1 hashes of Subject Public Key Info
1163 		 * for trust agents */
1164 	}
1165 
1166 	if (data->peer_auth == PEER_AUTH_SECRET) {
1167 		struct wpabuf *plain = wpabuf_alloc(data->IDr_len + 1000);
1168 		if (plain == NULL) {
1169 			wpabuf_free(msg);
1170 			return NULL;
1171 		}
1172 		if (ikev2_build_idr(data, plain,
1173 				    IKEV2_PAYLOAD_NO_NEXT_PAYLOAD) ||
1174 		    ikev2_build_encrypted(data->proposal.encr,
1175 					  data->proposal.integ,
1176 					  &data->keys, 0, msg, plain,
1177 					  IKEV2_PAYLOAD_IDr)) {
1178 			wpabuf_free(plain);
1179 			wpabuf_free(msg);
1180 			return NULL;
1181 		}
1182 		wpabuf_free(plain);
1183 	}
1184 
1185 	ikev2_update_hdr(msg);
1186 
1187 	wpa_hexdump_buf(MSG_MSGDUMP, "IKEV2: Sending message (SA_INIT)", msg);
1188 
1189 	data->state = SA_AUTH;
1190 
1191 	wpabuf_free(data->r_sign_msg);
1192 	data->r_sign_msg = wpabuf_dup(msg);
1193 
1194 	return msg;
1195 }
1196 
1197 
1198 static struct wpabuf * ikev2_build_sa_auth(struct ikev2_responder_data *data)
1199 {
1200 	struct wpabuf *msg, *plain;
1201 
1202 	/* build IKE_SA_AUTH: HDR, SK {IDr, [CERT,] AUTH} */
1203 
1204 	msg = wpabuf_alloc(sizeof(struct ikev2_hdr) + data->IDr_len + 1000);
1205 	if (msg == NULL)
1206 		return NULL;
1207 	ikev2_build_hdr(data, msg, IKE_SA_AUTH, IKEV2_PAYLOAD_ENCRYPTED, 1);
1208 
1209 	plain = wpabuf_alloc(data->IDr_len + 1000);
1210 	if (plain == NULL) {
1211 		wpabuf_free(msg);
1212 		return NULL;
1213 	}
1214 
1215 	if (ikev2_build_idr(data, plain, IKEV2_PAYLOAD_AUTHENTICATION) ||
1216 	    ikev2_build_auth(data, plain, IKEV2_PAYLOAD_NO_NEXT_PAYLOAD) ||
1217 	    ikev2_build_encrypted(data->proposal.encr, data->proposal.integ,
1218 				  &data->keys, 0, msg, plain,
1219 				  IKEV2_PAYLOAD_IDr)) {
1220 		wpabuf_free(plain);
1221 		wpabuf_free(msg);
1222 		return NULL;
1223 	}
1224 	wpabuf_free(plain);
1225 
1226 	wpa_hexdump_buf(MSG_MSGDUMP, "IKEV2: Sending message (SA_AUTH)", msg);
1227 
1228 	data->state = IKEV2_DONE;
1229 
1230 	return msg;
1231 }
1232 
1233 
1234 static struct wpabuf * ikev2_build_notify(struct ikev2_responder_data *data)
1235 {
1236 	struct wpabuf *msg;
1237 
1238 	msg = wpabuf_alloc(sizeof(struct ikev2_hdr) + 1000);
1239 	if (msg == NULL)
1240 		return NULL;
1241 	if (data->last_msg == LAST_MSG_SA_AUTH) {
1242 		/* HDR, SK{N} */
1243 		struct wpabuf *plain = wpabuf_alloc(100);
1244 		if (plain == NULL) {
1245 			wpabuf_free(msg);
1246 			return NULL;
1247 		}
1248 		ikev2_build_hdr(data, msg, IKE_SA_AUTH,
1249 				IKEV2_PAYLOAD_ENCRYPTED, 1);
1250 		if (ikev2_build_notification(data, plain,
1251 					     IKEV2_PAYLOAD_NO_NEXT_PAYLOAD) ||
1252 		    ikev2_build_encrypted(data->proposal.encr,
1253 					  data->proposal.integ,
1254 					  &data->keys, 0, msg, plain,
1255 					  IKEV2_PAYLOAD_NOTIFICATION)) {
1256 			wpabuf_free(plain);
1257 			wpabuf_free(msg);
1258 			return NULL;
1259 		}
1260 		data->state = IKEV2_FAILED;
1261 	} else {
1262 		/* HDR, N */
1263 		ikev2_build_hdr(data, msg, IKE_SA_INIT,
1264 				IKEV2_PAYLOAD_NOTIFICATION, 0);
1265 		if (ikev2_build_notification(data, msg,
1266 					     IKEV2_PAYLOAD_NO_NEXT_PAYLOAD)) {
1267 			wpabuf_free(msg);
1268 			return NULL;
1269 		}
1270 		data->state = SA_INIT;
1271 	}
1272 
1273 	ikev2_update_hdr(msg);
1274 
1275 	wpa_hexdump_buf(MSG_MSGDUMP, "IKEV2: Sending message (Notification)",
1276 			msg);
1277 
1278 	return msg;
1279 }
1280 
1281 
1282 struct wpabuf * ikev2_responder_build(struct ikev2_responder_data *data)
1283 {
1284 	switch (data->state) {
1285 	case SA_INIT:
1286 		return ikev2_build_sa_init(data);
1287 	case SA_AUTH:
1288 		return ikev2_build_sa_auth(data);
1289 	case CHILD_SA:
1290 		return NULL;
1291 	case NOTIFY:
1292 		return ikev2_build_notify(data);
1293 	case IKEV2_DONE:
1294 	case IKEV2_FAILED:
1295 		return NULL;
1296 	}
1297 	return NULL;
1298 }
1299