1/*
2 * IKEv2 responder (RFC 4306) for EAP-IKEV2
3 * Copyright (c) 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 "dh_groups.h"
19#include "ikev2.h"
20
21
22void ikev2_responder_deinit(struct ikev2_responder_data *data)
23{
24	ikev2_free_keys(&data->keys);
25	wpabuf_free(data->i_dh_public);
26	wpabuf_free(data->r_dh_private);
27	os_free(data->IDi);
28	os_free(data->IDr);
29	os_free(data->shared_secret);
30	wpabuf_free(data->i_sign_msg);
31	wpabuf_free(data->r_sign_msg);
32	os_free(data->key_pad);
33}
34
35
36static int ikev2_derive_keys(struct ikev2_responder_data *data)
37{
38	u8 *buf, *pos, *pad, skeyseed[IKEV2_MAX_HASH_LEN];
39	size_t buf_len, pad_len;
40	struct wpabuf *shared;
41	const struct ikev2_integ_alg *integ;
42	const struct ikev2_prf_alg *prf;
43	const struct ikev2_encr_alg *encr;
44	int ret;
45	const u8 *addr[2];
46	size_t len[2];
47
48	/* RFC 4306, Sect. 2.14 */
49
50	integ = ikev2_get_integ(data->proposal.integ);
51	prf = ikev2_get_prf(data->proposal.prf);
52	encr = ikev2_get_encr(data->proposal.encr);
53	if (integ == NULL || prf == NULL || encr == NULL) {
54		wpa_printf(MSG_INFO, "IKEV2: Unsupported proposal");
55		return -1;
56	}
57
58	shared = dh_derive_shared(data->i_dh_public, data->r_dh_private,
59				  data->dh);
60	if (shared == NULL)
61		return -1;
62
63	/* Construct Ni | Nr | SPIi | SPIr */
64
65	buf_len = data->i_nonce_len + data->r_nonce_len + 2 * IKEV2_SPI_LEN;
66	buf = os_malloc(buf_len);
67	if (buf == NULL) {
68		wpabuf_free(shared);
69		return -1;
70	}
71
72	pos = buf;
73	os_memcpy(pos, data->i_nonce, data->i_nonce_len);
74	pos += data->i_nonce_len;
75	os_memcpy(pos, data->r_nonce, data->r_nonce_len);
76	pos += data->r_nonce_len;
77	os_memcpy(pos, data->i_spi, IKEV2_SPI_LEN);
78	pos += IKEV2_SPI_LEN;
79	os_memcpy(pos, data->r_spi, IKEV2_SPI_LEN);
80#ifdef CCNS_PL
81#if __BYTE_ORDER == __LITTLE_ENDIAN
82	{
83		int i;
84		u8 *tmp = pos - IKEV2_SPI_LEN;
85		/* Incorrect byte re-ordering on little endian hosts.. */
86		for (i = 0; i < IKEV2_SPI_LEN; i++)
87			*tmp++ = data->i_spi[IKEV2_SPI_LEN - 1 - i];
88		for (i = 0; i < IKEV2_SPI_LEN; i++)
89			*tmp++ = data->r_spi[IKEV2_SPI_LEN - 1 - i];
90	}
91#endif
92#endif /* CCNS_PL */
93
94	/* SKEYSEED = prf(Ni | Nr, g^ir) */
95	/* Use zero-padding per RFC 4306, Sect. 2.14 */
96	pad_len = data->dh->prime_len - wpabuf_len(shared);
97#ifdef CCNS_PL
98	/* Shared secret is not zero-padded correctly */
99	pad_len = 0;
100#endif /* CCNS_PL */
101	pad = os_zalloc(pad_len ? pad_len : 1);
102	if (pad == NULL) {
103		wpabuf_free(shared);
104		os_free(buf);
105		return -1;
106	}
107
108	addr[0] = pad;
109	len[0] = pad_len;
110	addr[1] = wpabuf_head(shared);
111	len[1] = wpabuf_len(shared);
112	if (ikev2_prf_hash(prf->id, buf, data->i_nonce_len + data->r_nonce_len,
113			   2, addr, len, skeyseed) < 0) {
114		wpabuf_free(shared);
115		os_free(buf);
116		os_free(pad);
117		return -1;
118	}
119	os_free(pad);
120	wpabuf_free(shared);
121
122	/* DH parameters are not needed anymore, so free them */
123	wpabuf_free(data->i_dh_public);
124	data->i_dh_public = NULL;
125	wpabuf_free(data->r_dh_private);
126	data->r_dh_private = NULL;
127
128	wpa_hexdump_key(MSG_DEBUG, "IKEV2: SKEYSEED",
129			skeyseed, prf->hash_len);
130
131	ret = ikev2_derive_sk_keys(prf, integ, encr, skeyseed, buf, buf_len,
132				   &data->keys);
133	os_free(buf);
134	return ret;
135}
136
137
138static int ikev2_parse_transform(struct ikev2_proposal_data *prop,
139				 const u8 *pos, const u8 *end)
140{
141	int transform_len;
142	const struct ikev2_transform *t;
143	u16 transform_id;
144	const u8 *tend;
145
146	if (end - pos < (int) sizeof(*t)) {
147		wpa_printf(MSG_INFO, "IKEV2: Too short transform");
148		return -1;
149	}
150
151	t = (const struct ikev2_transform *) pos;
152	transform_len = WPA_GET_BE16(t->transform_length);
153	if (transform_len < (int) sizeof(*t) || pos + transform_len > end) {
154		wpa_printf(MSG_INFO, "IKEV2: Invalid transform length %d",
155			   transform_len);
156		return -1;
157	}
158	tend = pos + transform_len;
159
160	transform_id = WPA_GET_BE16(t->transform_id);
161
162	wpa_printf(MSG_DEBUG, "IKEV2:   Transform:");
163	wpa_printf(MSG_DEBUG, "IKEV2:     Type: %d  Transform Length: %d  "
164		   "Transform Type: %d  Transform ID: %d",
165		   t->type, transform_len, t->transform_type, transform_id);
166
167	if (t->type != 0 && t->type != 3) {
168		wpa_printf(MSG_INFO, "IKEV2: Unexpected Transform type");
169		return -1;
170	}
171
172	pos = (const u8 *) (t + 1);
173	if (pos < tend) {
174		wpa_hexdump(MSG_DEBUG, "IKEV2:     Transform Attributes",
175			    pos, tend - pos);
176	}
177
178	switch (t->transform_type) {
179	case IKEV2_TRANSFORM_ENCR:
180		if (ikev2_get_encr(transform_id)) {
181			if (transform_id == ENCR_AES_CBC) {
182				if (tend - pos != 4) {
183					wpa_printf(MSG_DEBUG, "IKEV2: No "
184						   "Transform Attr for AES");
185					break;
186				}
187#ifdef CCNS_PL
188				if (WPA_GET_BE16(pos) != 0x001d /* ?? */) {
189					wpa_printf(MSG_DEBUG, "IKEV2: Not a "
190						   "Key Size attribute for "
191						   "AES");
192					break;
193				}
194#else /* CCNS_PL */
195				if (WPA_GET_BE16(pos) != 0x800e) {
196					wpa_printf(MSG_DEBUG, "IKEV2: Not a "
197						   "Key Size attribute for "
198						   "AES");
199					break;
200				}
201#endif /* CCNS_PL */
202				if (WPA_GET_BE16(pos + 2) != 128) {
203					wpa_printf(MSG_DEBUG, "IKEV2: "
204						   "Unsupported AES key size "
205						   "%d bits",
206						   WPA_GET_BE16(pos + 2));
207					break;
208				}
209			}
210			prop->encr = transform_id;
211		}
212		break;
213	case IKEV2_TRANSFORM_PRF:
214		if (ikev2_get_prf(transform_id))
215			prop->prf = transform_id;
216		break;
217	case IKEV2_TRANSFORM_INTEG:
218		if (ikev2_get_integ(transform_id))
219			prop->integ = transform_id;
220		break;
221	case IKEV2_TRANSFORM_DH:
222		if (dh_groups_get(transform_id))
223			prop->dh = transform_id;
224		break;
225	}
226
227	return transform_len;
228}
229
230
231static int ikev2_parse_proposal(struct ikev2_proposal_data *prop,
232				const u8 *pos, const u8 *end)
233{
234	const u8 *pend, *ppos;
235	int proposal_len, i;
236	const struct ikev2_proposal *p;
237
238	if (end - pos < (int) sizeof(*p)) {
239		wpa_printf(MSG_INFO, "IKEV2: Too short proposal");
240		return -1;
241	}
242
243	/* FIX: AND processing if multiple proposals use the same # */
244
245	p = (const struct ikev2_proposal *) pos;
246	proposal_len = WPA_GET_BE16(p->proposal_length);
247	if (proposal_len < (int) sizeof(*p) || pos + proposal_len > end) {
248		wpa_printf(MSG_INFO, "IKEV2: Invalid proposal length %d",
249			   proposal_len);
250		return -1;
251	}
252	wpa_printf(MSG_DEBUG, "IKEV2: SAi1 Proposal # %d",
253		   p->proposal_num);
254	wpa_printf(MSG_DEBUG, "IKEV2:   Type: %d  Proposal Length: %d "
255		   " Protocol ID: %d",
256		   p->type, proposal_len, p->protocol_id);
257	wpa_printf(MSG_DEBUG, "IKEV2:   SPI Size: %d  Transforms: %d",
258		   p->spi_size, p->num_transforms);
259
260	if (p->type != 0 && p->type != 2) {
261		wpa_printf(MSG_INFO, "IKEV2: Unexpected Proposal type");
262		return -1;
263	}
264
265	if (p->protocol_id != IKEV2_PROTOCOL_IKE) {
266		wpa_printf(MSG_DEBUG, "IKEV2: Unexpected Protocol ID "
267			   "(only IKE allowed for EAP-IKEv2)");
268		return -1;
269	}
270
271	if (p->proposal_num != prop->proposal_num) {
272		if (p->proposal_num == prop->proposal_num + 1)
273			prop->proposal_num = p->proposal_num;
274		else {
275			wpa_printf(MSG_INFO, "IKEV2: Unexpected Proposal #");
276			return -1;
277		}
278	}
279
280	ppos = (const u8 *) (p + 1);
281	pend = pos + proposal_len;
282	if (ppos + p->spi_size > pend) {
283		wpa_printf(MSG_INFO, "IKEV2: Not enough room for SPI "
284			   "in proposal");
285		return -1;
286	}
287	if (p->spi_size) {
288		wpa_hexdump(MSG_DEBUG, "IKEV2:    SPI",
289			    ppos, p->spi_size);
290		ppos += p->spi_size;
291	}
292
293	/*
294	 * For initial IKE_SA negotiation, SPI Size MUST be zero; for
295	 * subsequent negotiations, it must be 8 for IKE. We only support
296	 * initial case for now.
297	 */
298	if (p->spi_size != 0) {
299		wpa_printf(MSG_INFO, "IKEV2: Unexpected SPI Size");
300		return -1;
301	}
302
303	if (p->num_transforms == 0) {
304		wpa_printf(MSG_INFO, "IKEV2: At least one transform required");
305		return -1;
306	}
307
308	for (i = 0; i < (int) p->num_transforms; i++) {
309		int tlen = ikev2_parse_transform(prop, ppos, pend);
310		if (tlen < 0)
311			return -1;
312		ppos += tlen;
313	}
314
315	if (ppos != pend) {
316		wpa_printf(MSG_INFO, "IKEV2: Unexpected data after "
317			   "transforms");
318		return -1;
319	}
320
321	return proposal_len;
322}
323
324
325static int ikev2_process_sai1(struct ikev2_responder_data *data,
326			      const u8 *sai1, size_t sai1_len)
327{
328	struct ikev2_proposal_data prop;
329	const u8 *pos, *end;
330	int found = 0;
331
332	/* Security Association Payloads: <Proposals> */
333
334	if (sai1 == NULL) {
335		wpa_printf(MSG_INFO, "IKEV2: SAi1 not received");
336		return -1;
337	}
338
339	os_memset(&prop, 0, sizeof(prop));
340	prop.proposal_num = 1;
341
342	pos = sai1;
343	end = sai1 + sai1_len;
344
345	while (pos < end) {
346		int plen;
347
348		prop.integ = -1;
349		prop.prf = -1;
350		prop.encr = -1;
351		prop.dh = -1;
352		plen = ikev2_parse_proposal(&prop, pos, end);
353		if (plen < 0)
354			return -1;
355
356		if (!found && prop.integ != -1 && prop.prf != -1 &&
357		    prop.encr != -1 && prop.dh != -1) {
358			os_memcpy(&data->proposal, &prop, sizeof(prop));
359			data->dh = dh_groups_get(prop.dh);
360			found = 1;
361		}
362
363		pos += plen;
364	}
365
366	if (pos != end) {
367		wpa_printf(MSG_INFO, "IKEV2: Unexpected data after proposals");
368		return -1;
369	}
370
371	if (!found) {
372		wpa_printf(MSG_INFO, "IKEV2: No acceptable proposal found");
373		return -1;
374	}
375
376	wpa_printf(MSG_DEBUG, "IKEV2: Accepted proposal #%d: ENCR:%d PRF:%d "
377		   "INTEG:%d D-H:%d", data->proposal.proposal_num,
378		   data->proposal.encr, data->proposal.prf,
379		   data->proposal.integ, data->proposal.dh);
380
381	return 0;
382}
383
384
385static int ikev2_process_kei(struct ikev2_responder_data *data,
386			     const u8 *kei, size_t kei_len)
387{
388	u16 group;
389
390	/*
391	 * Key Exchange Payload:
392	 * DH Group # (16 bits)
393	 * RESERVED (16 bits)
394	 * Key Exchange Data (Diffie-Hellman public value)
395	 */
396
397	if (kei == NULL) {
398		wpa_printf(MSG_INFO, "IKEV2: KEi not received");
399		return -1;
400	}
401
402	if (kei_len < 4 + 96) {
403		wpa_printf(MSG_INFO, "IKEV2: Too show Key Exchange Payload");
404		return -1;
405	}
406
407	group = WPA_GET_BE16(kei);
408	wpa_printf(MSG_DEBUG, "IKEV2: KEi DH Group #%u", group);
409
410	if (group != data->proposal.dh) {
411		wpa_printf(MSG_DEBUG, "IKEV2: KEi DH Group #%u does not match "
412			   "with the selected proposal (%u)",
413			   group, data->proposal.dh);
414		/* Reject message with Notify payload of type
415		 * INVALID_KE_PAYLOAD (RFC 4306, Sect. 3.4) */
416		data->error_type = INVALID_KE_PAYLOAD;
417		data->state = NOTIFY;
418		return -1;
419	}
420
421	if (data->dh == NULL) {
422		wpa_printf(MSG_INFO, "IKEV2: Unsupported DH group");
423		return -1;
424	}
425
426	/* RFC 4306, Section 3.4:
427	 * The length of DH public value MUST be equal to the lenght of the
428	 * prime modulus.
429	 */
430	if (kei_len - 4 != data->dh->prime_len) {
431		wpa_printf(MSG_INFO, "IKEV2: Invalid DH public value length "
432			   "%ld (expected %ld)",
433			   (long) (kei_len - 4), (long) data->dh->prime_len);
434		return -1;
435	}
436
437	wpabuf_free(data->i_dh_public);
438	data->i_dh_public = wpabuf_alloc(kei_len - 4);
439	if (data->i_dh_public == NULL)
440		return -1;
441	wpabuf_put_data(data->i_dh_public, kei + 4, kei_len - 4);
442
443	wpa_hexdump_buf(MSG_DEBUG, "IKEV2: KEi Diffie-Hellman Public Value",
444			data->i_dh_public);
445
446	return 0;
447}
448
449
450static int ikev2_process_ni(struct ikev2_responder_data *data,
451			    const u8 *ni, size_t ni_len)
452{
453	if (ni == NULL) {
454		wpa_printf(MSG_INFO, "IKEV2: Ni not received");
455		return -1;
456	}
457
458	if (ni_len < IKEV2_NONCE_MIN_LEN || ni_len > IKEV2_NONCE_MAX_LEN) {
459		wpa_printf(MSG_INFO, "IKEV2: Invalid Ni length %ld",
460		           (long) ni_len);
461		return -1;
462	}
463
464#ifdef CCNS_PL
465	/* Zeros are removed incorrectly from the beginning of the nonces */
466	while (ni_len > 1 && *ni == 0) {
467		ni_len--;
468		ni++;
469	}
470#endif /* CCNS_PL */
471
472	data->i_nonce_len = ni_len;
473	os_memcpy(data->i_nonce, ni, ni_len);
474	wpa_hexdump(MSG_MSGDUMP, "IKEV2: Ni",
475		    data->i_nonce, data->i_nonce_len);
476
477	return 0;
478}
479
480
481static int ikev2_process_sa_init(struct ikev2_responder_data *data,
482				 const struct ikev2_hdr *hdr,
483				 struct ikev2_payloads *pl)
484{
485	if (ikev2_process_sai1(data, pl->sa, pl->sa_len) < 0 ||
486	    ikev2_process_kei(data, pl->ke, pl->ke_len) < 0 ||
487	    ikev2_process_ni(data, pl->nonce, pl->nonce_len) < 0)
488		return -1;
489
490	os_memcpy(data->i_spi, hdr->i_spi, IKEV2_SPI_LEN);
491
492	return 0;
493}
494
495
496static int ikev2_process_idi(struct ikev2_responder_data *data,
497			     const u8 *idi, size_t idi_len)
498{
499	u8 id_type;
500
501	if (idi == NULL) {
502		wpa_printf(MSG_INFO, "IKEV2: No IDi received");
503		return -1;
504	}
505
506	if (idi_len < 4) {
507		wpa_printf(MSG_INFO, "IKEV2: Too short IDi payload");
508		return -1;
509	}
510
511	id_type = idi[0];
512	idi += 4;
513	idi_len -= 4;
514
515	wpa_printf(MSG_DEBUG, "IKEV2: IDi ID Type %d", id_type);
516	wpa_hexdump_ascii(MSG_DEBUG, "IKEV2: IDi", idi, idi_len);
517	os_free(data->IDi);
518	data->IDi = os_malloc(idi_len);
519	if (data->IDi == NULL)
520		return -1;
521	os_memcpy(data->IDi, idi, idi_len);
522	data->IDi_len = idi_len;
523	data->IDi_type = id_type;
524
525	return 0;
526}
527
528
529static int ikev2_process_cert(struct ikev2_responder_data *data,
530			      const u8 *cert, size_t cert_len)
531{
532	u8 cert_encoding;
533
534	if (cert == NULL) {
535		if (data->peer_auth == PEER_AUTH_CERT) {
536			wpa_printf(MSG_INFO, "IKEV2: No Certificate received");
537			return -1;
538		}
539		return 0;
540	}
541
542	if (cert_len < 1) {
543		wpa_printf(MSG_INFO, "IKEV2: No Cert Encoding field");
544		return -1;
545	}
546
547	cert_encoding = cert[0];
548	cert++;
549	cert_len--;
550
551	wpa_printf(MSG_DEBUG, "IKEV2: Cert Encoding %d", cert_encoding);
552	wpa_hexdump(MSG_MSGDUMP, "IKEV2: Certificate Data", cert, cert_len);
553
554	/* TODO: validate certificate */
555
556	return 0;
557}
558
559
560static int ikev2_process_auth_cert(struct ikev2_responder_data *data,
561				   u8 method, const u8 *auth, size_t auth_len)
562{
563	if (method != AUTH_RSA_SIGN) {
564		wpa_printf(MSG_INFO, "IKEV2: Unsupported authentication "
565			   "method %d", method);
566		return -1;
567	}
568
569	/* TODO: validate AUTH */
570	return 0;
571}
572
573
574static int ikev2_process_auth_secret(struct ikev2_responder_data *data,
575				     u8 method, const u8 *auth,
576				     size_t auth_len)
577{
578	u8 auth_data[IKEV2_MAX_HASH_LEN];
579	const struct ikev2_prf_alg *prf;
580
581	if (method != AUTH_SHARED_KEY_MIC) {
582		wpa_printf(MSG_INFO, "IKEV2: Unsupported authentication "
583			   "method %d", method);
584		return -1;
585	}
586
587	/* msg | Nr | prf(SK_pi,IDi') */
588	if (ikev2_derive_auth_data(data->proposal.prf, data->i_sign_msg,
589				   data->IDi, data->IDi_len, data->IDi_type,
590				   &data->keys, 1, data->shared_secret,
591				   data->shared_secret_len,
592				   data->r_nonce, data->r_nonce_len,
593				   data->key_pad, data->key_pad_len,
594				   auth_data) < 0) {
595		wpa_printf(MSG_INFO, "IKEV2: Could not derive AUTH data");
596		return -1;
597	}
598
599	wpabuf_free(data->i_sign_msg);
600	data->i_sign_msg = NULL;
601
602	prf = ikev2_get_prf(data->proposal.prf);
603	if (prf == NULL)
604		return -1;
605
606	if (auth_len != prf->hash_len ||
607	    os_memcmp(auth, auth_data, auth_len) != 0) {
608		wpa_printf(MSG_INFO, "IKEV2: Invalid Authentication Data");
609		wpa_hexdump(MSG_DEBUG, "IKEV2: Received Authentication Data",
610			    auth, auth_len);
611		wpa_hexdump(MSG_DEBUG, "IKEV2: Expected Authentication Data",
612			    auth_data, prf->hash_len);
613		data->error_type = AUTHENTICATION_FAILED;
614		data->state = NOTIFY;
615		return -1;
616	}
617
618	wpa_printf(MSG_DEBUG, "IKEV2: Server authenticated successfully "
619		   "using shared keys");
620
621	return 0;
622}
623
624
625static int ikev2_process_auth(struct ikev2_responder_data *data,
626			      const u8 *auth, size_t auth_len)
627{
628	u8 auth_method;
629
630	if (auth == NULL) {
631		wpa_printf(MSG_INFO, "IKEV2: No Authentication Payload");
632		return -1;
633	}
634
635	if (auth_len < 4) {
636		wpa_printf(MSG_INFO, "IKEV2: Too short Authentication "
637			   "Payload");
638		return -1;
639	}
640
641	auth_method = auth[0];
642	auth += 4;
643	auth_len -= 4;
644
645	wpa_printf(MSG_DEBUG, "IKEV2: Auth Method %d", auth_method);
646	wpa_hexdump(MSG_MSGDUMP, "IKEV2: Authentication Data", auth, auth_len);
647
648	switch (data->peer_auth) {
649	case PEER_AUTH_CERT:
650		return ikev2_process_auth_cert(data, auth_method, auth,
651					       auth_len);
652	case PEER_AUTH_SECRET:
653		return ikev2_process_auth_secret(data, auth_method, auth,
654						 auth_len);
655	}
656
657	return -1;
658}
659
660
661static int ikev2_process_sa_auth_decrypted(struct ikev2_responder_data *data,
662					   u8 next_payload,
663					   u8 *payload, size_t payload_len)
664{
665	struct ikev2_payloads pl;
666
667	wpa_printf(MSG_DEBUG, "IKEV2: Processing decrypted payloads");
668
669	if (ikev2_parse_payloads(&pl, next_payload, payload, payload +
670				 payload_len) < 0) {
671		wpa_printf(MSG_INFO, "IKEV2: Failed to parse decrypted "
672			   "payloads");
673		return -1;
674	}
675
676	if (ikev2_process_idi(data, pl.idi, pl.idi_len) < 0 ||
677	    ikev2_process_cert(data, pl.cert, pl.cert_len) < 0 ||
678	    ikev2_process_auth(data, pl.auth, pl.auth_len) < 0)
679		return -1;
680
681	return 0;
682}
683
684
685static int ikev2_process_sa_auth(struct ikev2_responder_data *data,
686				 const struct ikev2_hdr *hdr,
687				 struct ikev2_payloads *pl)
688{
689	u8 *decrypted;
690	size_t decrypted_len;
691	int ret;
692
693	decrypted = ikev2_decrypt_payload(data->proposal.encr,
694					  data->proposal.integ,
695					  &data->keys, 1, hdr, pl->encrypted,
696					  pl->encrypted_len, &decrypted_len);
697	if (decrypted == NULL)
698		return -1;
699
700	ret = ikev2_process_sa_auth_decrypted(data, pl->encr_next_payload,
701					      decrypted, decrypted_len);
702	os_free(decrypted);
703
704	return ret;
705}
706
707
708static int ikev2_validate_rx_state(struct ikev2_responder_data *data,
709				   u8 exchange_type, u32 message_id)
710{
711	switch (data->state) {
712	case SA_INIT:
713		/* Expect to receive IKE_SA_INIT: HDR, SAi1, KEi, Ni */
714		if (exchange_type != IKE_SA_INIT) {
715			wpa_printf(MSG_INFO, "IKEV2: Unexpected Exchange Type "
716				   "%u in SA_INIT state", exchange_type);
717			return -1;
718		}
719		if (message_id != 0) {
720			wpa_printf(MSG_INFO, "IKEV2: Unexpected Message ID %u "
721				   "in SA_INIT state", message_id);
722			return -1;
723		}
724		break;
725	case SA_AUTH:
726		/* Expect to receive IKE_SA_AUTH:
727		 * HDR, SK {IDi, [CERT,] [CERTREQ,] [IDr,]
728		 *	AUTH, SAi2, TSi, TSr}
729		 */
730		if (exchange_type != IKE_SA_AUTH) {
731			wpa_printf(MSG_INFO, "IKEV2: Unexpected Exchange Type "
732				   "%u in SA_AUTH state", exchange_type);
733			return -1;
734		}
735		if (message_id != 1) {
736			wpa_printf(MSG_INFO, "IKEV2: Unexpected Message ID %u "
737				   "in SA_AUTH state", message_id);
738			return -1;
739		}
740		break;
741	case CHILD_SA:
742		if (exchange_type != CREATE_CHILD_SA) {
743			wpa_printf(MSG_INFO, "IKEV2: Unexpected Exchange Type "
744				   "%u in CHILD_SA state", exchange_type);
745			return -1;
746		}
747		if (message_id != 2) {
748			wpa_printf(MSG_INFO, "IKEV2: Unexpected Message ID %u "
749				   "in CHILD_SA state", message_id);
750			return -1;
751		}
752		break;
753	case NOTIFY:
754	case IKEV2_DONE:
755	case IKEV2_FAILED:
756		return -1;
757	}
758
759	return 0;
760}
761
762
763int ikev2_responder_process(struct ikev2_responder_data *data,
764			    const struct wpabuf *buf)
765{
766	const struct ikev2_hdr *hdr;
767	u32 length, message_id;
768	const u8 *pos, *end;
769	struct ikev2_payloads pl;
770
771	wpa_printf(MSG_MSGDUMP, "IKEV2: Received message (len %lu)",
772		   (unsigned long) wpabuf_len(buf));
773
774	if (wpabuf_len(buf) < sizeof(*hdr)) {
775		wpa_printf(MSG_INFO, "IKEV2: Too short frame to include HDR");
776		return -1;
777	}
778
779	data->error_type = 0;
780	hdr = (const struct ikev2_hdr *) wpabuf_head(buf);
781	end = wpabuf_head_u8(buf) + wpabuf_len(buf);
782	message_id = WPA_GET_BE32(hdr->message_id);
783	length = WPA_GET_BE32(hdr->length);
784
785	wpa_hexdump(MSG_DEBUG, "IKEV2:   IKE_SA Initiator's SPI",
786		    hdr->i_spi, IKEV2_SPI_LEN);
787	wpa_hexdump(MSG_DEBUG, "IKEV2:   IKE_SA Responder's SPI",
788		    hdr->r_spi, IKEV2_SPI_LEN);
789	wpa_printf(MSG_DEBUG, "IKEV2:   Next Payload: %u  Version: 0x%x  "
790		   "Exchange Type: %u",
791		   hdr->next_payload, hdr->version, hdr->exchange_type);
792	wpa_printf(MSG_DEBUG, "IKEV2:   Message ID: %u  Length: %u",
793		   message_id, length);
794
795	if (hdr->version != IKEV2_VERSION) {
796		wpa_printf(MSG_INFO, "IKEV2: Unsupported HDR version 0x%x "
797			   "(expected 0x%x)", hdr->version, IKEV2_VERSION);
798		return -1;
799	}
800
801	if (length != wpabuf_len(buf)) {
802		wpa_printf(MSG_INFO, "IKEV2: Invalid length (HDR: %lu != "
803			   "RX: %lu)", (unsigned long) length,
804			   (unsigned long) wpabuf_len(buf));
805		return -1;
806	}
807
808	if (ikev2_validate_rx_state(data, hdr->exchange_type, message_id) < 0)
809		return -1;
810
811	if ((hdr->flags & (IKEV2_HDR_INITIATOR | IKEV2_HDR_RESPONSE)) !=
812	    IKEV2_HDR_INITIATOR) {
813		wpa_printf(MSG_INFO, "IKEV2: Unexpected Flags value 0x%x",
814			   hdr->flags);
815		return -1;
816	}
817
818	if (data->state != SA_INIT) {
819		if (os_memcmp(data->i_spi, hdr->i_spi, IKEV2_SPI_LEN) != 0) {
820			wpa_printf(MSG_INFO, "IKEV2: Unexpected IKE_SA "
821				   "Initiator's SPI");
822			return -1;
823		}
824		if (os_memcmp(data->r_spi, hdr->r_spi, IKEV2_SPI_LEN) != 0) {
825			wpa_printf(MSG_INFO, "IKEV2: Unexpected IKE_SA "
826				   "Responder's SPI");
827			return -1;
828		}
829	}
830
831	pos = (const u8 *) (hdr + 1);
832	if (ikev2_parse_payloads(&pl, hdr->next_payload, pos, end) < 0)
833		return -1;
834
835	if (data->state == SA_INIT) {
836		data->last_msg = LAST_MSG_SA_INIT;
837		if (ikev2_process_sa_init(data, hdr, &pl) < 0) {
838			if (data->state == NOTIFY)
839				return 0;
840			return -1;
841		}
842		wpabuf_free(data->i_sign_msg);
843		data->i_sign_msg = wpabuf_dup(buf);
844	}
845
846	if (data->state == SA_AUTH) {
847		data->last_msg = LAST_MSG_SA_AUTH;
848		if (ikev2_process_sa_auth(data, hdr, &pl) < 0) {
849			if (data->state == NOTIFY)
850				return 0;
851			return -1;
852		}
853	}
854
855	return 0;
856}
857
858
859static void ikev2_build_hdr(struct ikev2_responder_data *data,
860			    struct wpabuf *msg, u8 exchange_type,
861			    u8 next_payload, u32 message_id)
862{
863	struct ikev2_hdr *hdr;
864
865	wpa_printf(MSG_DEBUG, "IKEV2: Adding HDR");
866
867	/* HDR - RFC 4306, Sect. 3.1 */
868	hdr = wpabuf_put(msg, sizeof(*hdr));
869	os_memcpy(hdr->i_spi, data->i_spi, IKEV2_SPI_LEN);
870	os_memcpy(hdr->r_spi, data->r_spi, IKEV2_SPI_LEN);
871	hdr->next_payload = next_payload;
872	hdr->version = IKEV2_VERSION;
873	hdr->exchange_type = exchange_type;
874	hdr->flags = IKEV2_HDR_RESPONSE;
875	WPA_PUT_BE32(hdr->message_id, message_id);
876}
877
878
879static int ikev2_build_sar1(struct ikev2_responder_data *data,
880			    struct wpabuf *msg, u8 next_payload)
881{
882	struct ikev2_payload_hdr *phdr;
883	size_t plen;
884	struct ikev2_proposal *p;
885	struct ikev2_transform *t;
886
887	wpa_printf(MSG_DEBUG, "IKEV2: Adding SAr1 payload");
888
889	/* SAr1 - RFC 4306, Sect. 2.7 and 3.3 */
890	phdr = wpabuf_put(msg, sizeof(*phdr));
891	phdr->next_payload = next_payload;
892	phdr->flags = 0;
893
894	p = wpabuf_put(msg, sizeof(*p));
895#ifdef CCNS_PL
896	/* Seems to require that the Proposal # is 1 even though RFC 4306
897	 * Sect 3.3.1 has following requirement "When a proposal is accepted,
898	 * all of the proposal numbers in the SA payload MUST be the same and
899	 * MUST match the number on the proposal sent that was accepted.".
900	 */
901	p->proposal_num = 1;
902#else /* CCNS_PL */
903	p->proposal_num = data->proposal.proposal_num;
904#endif /* CCNS_PL */
905	p->protocol_id = IKEV2_PROTOCOL_IKE;
906	p->num_transforms = 4;
907
908	t = wpabuf_put(msg, sizeof(*t));
909	t->type = 3;
910	t->transform_type = IKEV2_TRANSFORM_ENCR;
911	WPA_PUT_BE16(t->transform_id, data->proposal.encr);
912	if (data->proposal.encr == ENCR_AES_CBC) {
913		/* Transform Attribute: Key Len = 128 bits */
914#ifdef CCNS_PL
915		wpabuf_put_be16(msg, 0x001d); /* ?? */
916#else /* CCNS_PL */
917		wpabuf_put_be16(msg, 0x800e); /* AF=1, AttrType=14 */
918#endif /* CCNS_PL */
919		wpabuf_put_be16(msg, 128); /* 128-bit key */
920	}
921	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) t;
922	WPA_PUT_BE16(t->transform_length, plen);
923
924	t = wpabuf_put(msg, sizeof(*t));
925	t->type = 3;
926	WPA_PUT_BE16(t->transform_length, sizeof(*t));
927	t->transform_type = IKEV2_TRANSFORM_PRF;
928	WPA_PUT_BE16(t->transform_id, data->proposal.prf);
929
930	t = wpabuf_put(msg, sizeof(*t));
931	t->type = 3;
932	WPA_PUT_BE16(t->transform_length, sizeof(*t));
933	t->transform_type = IKEV2_TRANSFORM_INTEG;
934	WPA_PUT_BE16(t->transform_id, data->proposal.integ);
935
936	t = wpabuf_put(msg, sizeof(*t));
937	WPA_PUT_BE16(t->transform_length, sizeof(*t));
938	t->transform_type = IKEV2_TRANSFORM_DH;
939	WPA_PUT_BE16(t->transform_id, data->proposal.dh);
940
941	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) p;
942	WPA_PUT_BE16(p->proposal_length, plen);
943
944	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
945	WPA_PUT_BE16(phdr->payload_length, plen);
946
947	return 0;
948}
949
950
951static int ikev2_build_ker(struct ikev2_responder_data *data,
952			   struct wpabuf *msg, u8 next_payload)
953{
954	struct ikev2_payload_hdr *phdr;
955	size_t plen;
956	struct wpabuf *pv;
957
958	wpa_printf(MSG_DEBUG, "IKEV2: Adding KEr payload");
959
960	pv = dh_init(data->dh, &data->r_dh_private);
961	if (pv == NULL) {
962		wpa_printf(MSG_DEBUG, "IKEV2: Failed to initialize DH");
963		return -1;
964	}
965
966	/* KEr - RFC 4306, Sect. 3.4 */
967	phdr = wpabuf_put(msg, sizeof(*phdr));
968	phdr->next_payload = next_payload;
969	phdr->flags = 0;
970
971	wpabuf_put_be16(msg, data->proposal.dh); /* DH Group # */
972	wpabuf_put(msg, 2); /* RESERVED */
973	/*
974	 * RFC 4306, Sect. 3.4: possible zero padding for public value to
975	 * match the length of the prime.
976	 */
977	wpabuf_put(msg, data->dh->prime_len - wpabuf_len(pv));
978	wpabuf_put_buf(msg, pv);
979	wpabuf_free(pv);
980
981	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
982	WPA_PUT_BE16(phdr->payload_length, plen);
983	return 0;
984}
985
986
987static int ikev2_build_nr(struct ikev2_responder_data *data,
988			  struct wpabuf *msg, u8 next_payload)
989{
990	struct ikev2_payload_hdr *phdr;
991	size_t plen;
992
993	wpa_printf(MSG_DEBUG, "IKEV2: Adding Nr payload");
994
995	/* Nr - RFC 4306, Sect. 3.9 */
996	phdr = wpabuf_put(msg, sizeof(*phdr));
997	phdr->next_payload = next_payload;
998	phdr->flags = 0;
999	wpabuf_put_data(msg, data->r_nonce, data->r_nonce_len);
1000	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
1001	WPA_PUT_BE16(phdr->payload_length, plen);
1002	return 0;
1003}
1004
1005
1006static int ikev2_build_idr(struct ikev2_responder_data *data,
1007			   struct wpabuf *msg, u8 next_payload)
1008{
1009	struct ikev2_payload_hdr *phdr;
1010	size_t plen;
1011
1012	wpa_printf(MSG_DEBUG, "IKEV2: Adding IDr payload");
1013
1014	if (data->IDr == NULL) {
1015		wpa_printf(MSG_INFO, "IKEV2: No IDr available");
1016		return -1;
1017	}
1018
1019	/* IDr - RFC 4306, Sect. 3.5 */
1020	phdr = wpabuf_put(msg, sizeof(*phdr));
1021	phdr->next_payload = next_payload;
1022	phdr->flags = 0;
1023	wpabuf_put_u8(msg, ID_KEY_ID);
1024	wpabuf_put(msg, 3); /* RESERVED */
1025	wpabuf_put_data(msg, data->IDr, data->IDr_len);
1026	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
1027	WPA_PUT_BE16(phdr->payload_length, plen);
1028	return 0;
1029}
1030
1031
1032static int ikev2_build_auth(struct ikev2_responder_data *data,
1033			    struct wpabuf *msg, u8 next_payload)
1034{
1035	struct ikev2_payload_hdr *phdr;
1036	size_t plen;
1037	const struct ikev2_prf_alg *prf;
1038
1039	wpa_printf(MSG_DEBUG, "IKEV2: Adding AUTH payload");
1040
1041	prf = ikev2_get_prf(data->proposal.prf);
1042	if (prf == NULL)
1043		return -1;
1044
1045	/* Authentication - RFC 4306, Sect. 3.8 */
1046	phdr = wpabuf_put(msg, sizeof(*phdr));
1047	phdr->next_payload = next_payload;
1048	phdr->flags = 0;
1049	wpabuf_put_u8(msg, AUTH_SHARED_KEY_MIC);
1050	wpabuf_put(msg, 3); /* RESERVED */
1051
1052	/* msg | Ni | prf(SK_pr,IDr') */
1053	if (ikev2_derive_auth_data(data->proposal.prf, data->r_sign_msg,
1054				   data->IDr, data->IDr_len, ID_KEY_ID,
1055				   &data->keys, 0, data->shared_secret,
1056				   data->shared_secret_len,
1057				   data->i_nonce, data->i_nonce_len,
1058				   data->key_pad, data->key_pad_len,
1059				   wpabuf_put(msg, prf->hash_len)) < 0) {
1060		wpa_printf(MSG_INFO, "IKEV2: Could not derive AUTH data");
1061		return -1;
1062	}
1063	wpabuf_free(data->r_sign_msg);
1064	data->r_sign_msg = NULL;
1065
1066	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
1067	WPA_PUT_BE16(phdr->payload_length, plen);
1068	return 0;
1069}
1070
1071
1072static int ikev2_build_notification(struct ikev2_responder_data *data,
1073				    struct wpabuf *msg, u8 next_payload)
1074{
1075	struct ikev2_payload_hdr *phdr;
1076	size_t plen;
1077
1078	wpa_printf(MSG_DEBUG, "IKEV2: Adding Notification payload");
1079
1080	if (data->error_type == 0) {
1081		wpa_printf(MSG_INFO, "IKEV2: No Notify Message Type "
1082			   "available");
1083		return -1;
1084	}
1085
1086	/* Notify - RFC 4306, Sect. 3.10 */
1087	phdr = wpabuf_put(msg, sizeof(*phdr));
1088	phdr->next_payload = next_payload;
1089	phdr->flags = 0;
1090#ifdef CCNS_PL
1091	wpabuf_put_u8(msg, 1); /* Protocol ID: IKE_SA notification */
1092#else /* CCNS_PL */
1093	wpabuf_put_u8(msg, 0); /* Protocol ID: no existing SA */
1094#endif /* CCNS_PL */
1095	wpabuf_put_u8(msg, 0); /* SPI Size */
1096	wpabuf_put_be16(msg, data->error_type);
1097
1098	switch (data->error_type) {
1099	case INVALID_KE_PAYLOAD:
1100		if (data->proposal.dh == -1) {
1101			wpa_printf(MSG_INFO, "IKEV2: No DH Group selected for "
1102				   "INVALID_KE_PAYLOAD notifications");
1103			return -1;
1104		}
1105		wpabuf_put_be16(msg, data->proposal.dh);
1106		wpa_printf(MSG_DEBUG, "IKEV2: INVALID_KE_PAYLOAD - request "
1107			   "DH Group #%d", data->proposal.dh);
1108		break;
1109	case AUTHENTICATION_FAILED:
1110		/* no associated data */
1111		break;
1112	default:
1113		wpa_printf(MSG_INFO, "IKEV2: Unsupported Notify Message Type "
1114			   "%d", data->error_type);
1115		return -1;
1116	}
1117
1118	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
1119	WPA_PUT_BE16(phdr->payload_length, plen);
1120	return 0;
1121}
1122
1123
1124static struct wpabuf * ikev2_build_sa_init(struct ikev2_responder_data *data)
1125{
1126	struct wpabuf *msg;
1127
1128	/* build IKE_SA_INIT: HDR, SAr1, KEr, Nr, [CERTREQ], [SK{IDr}] */
1129
1130	if (os_get_random(data->r_spi, IKEV2_SPI_LEN))
1131		return NULL;
1132	wpa_hexdump(MSG_DEBUG, "IKEV2: IKE_SA Responder's SPI",
1133		    data->r_spi, IKEV2_SPI_LEN);
1134
1135	data->r_nonce_len = IKEV2_NONCE_MIN_LEN;
1136	if (os_get_random(data->r_nonce, data->r_nonce_len))
1137		return NULL;
1138#ifdef CCNS_PL
1139	/* Zeros are removed incorrectly from the beginning of the nonces in
1140	 * key derivation; as a workaround, make sure Nr does not start with
1141	 * zero.. */
1142	if (data->r_nonce[0] == 0)
1143		data->r_nonce[0] = 1;
1144#endif /* CCNS_PL */
1145	wpa_hexdump(MSG_DEBUG, "IKEV2: Nr", data->r_nonce, data->r_nonce_len);
1146
1147	msg = wpabuf_alloc(sizeof(struct ikev2_hdr) + data->IDr_len + 1500);
1148	if (msg == NULL)
1149		return NULL;
1150
1151	ikev2_build_hdr(data, msg, IKE_SA_INIT, IKEV2_PAYLOAD_SA, 0);
1152	if (ikev2_build_sar1(data, msg, IKEV2_PAYLOAD_KEY_EXCHANGE) ||
1153	    ikev2_build_ker(data, msg, IKEV2_PAYLOAD_NONCE) ||
1154	    ikev2_build_nr(data, msg, data->peer_auth == PEER_AUTH_SECRET ?
1155			   IKEV2_PAYLOAD_ENCRYPTED :
1156			   IKEV2_PAYLOAD_NO_NEXT_PAYLOAD)) {
1157		wpabuf_free(msg);
1158		return NULL;
1159	}
1160
1161	if (ikev2_derive_keys(data)) {
1162		wpabuf_free(msg);
1163		return NULL;
1164	}
1165
1166	if (data->peer_auth == PEER_AUTH_CERT) {
1167		/* TODO: CERTREQ with SHA-1 hashes of Subject Public Key Info
1168		 * for trust agents */
1169	}
1170
1171	if (data->peer_auth == PEER_AUTH_SECRET) {
1172		struct wpabuf *plain = wpabuf_alloc(data->IDr_len + 1000);
1173		if (plain == NULL) {
1174			wpabuf_free(msg);
1175			return NULL;
1176		}
1177		if (ikev2_build_idr(data, plain,
1178				    IKEV2_PAYLOAD_NO_NEXT_PAYLOAD) ||
1179		    ikev2_build_encrypted(data->proposal.encr,
1180					  data->proposal.integ,
1181					  &data->keys, 0, msg, plain,
1182					  IKEV2_PAYLOAD_IDr)) {
1183			wpabuf_free(plain);
1184			wpabuf_free(msg);
1185			return NULL;
1186		}
1187		wpabuf_free(plain);
1188	}
1189
1190	ikev2_update_hdr(msg);
1191
1192	wpa_hexdump_buf(MSG_MSGDUMP, "IKEV2: Sending message (SA_INIT)", msg);
1193
1194	data->state = SA_AUTH;
1195
1196	wpabuf_free(data->r_sign_msg);
1197	data->r_sign_msg = wpabuf_dup(msg);
1198
1199	return msg;
1200}
1201
1202
1203static struct wpabuf * ikev2_build_sa_auth(struct ikev2_responder_data *data)
1204{
1205	struct wpabuf *msg, *plain;
1206
1207	/* build IKE_SA_AUTH: HDR, SK {IDr, [CERT,] AUTH} */
1208
1209	msg = wpabuf_alloc(sizeof(struct ikev2_hdr) + data->IDr_len + 1000);
1210	if (msg == NULL)
1211		return NULL;
1212	ikev2_build_hdr(data, msg, IKE_SA_AUTH, IKEV2_PAYLOAD_ENCRYPTED, 1);
1213
1214	plain = wpabuf_alloc(data->IDr_len + 1000);
1215	if (plain == NULL) {
1216		wpabuf_free(msg);
1217		return NULL;
1218	}
1219
1220	if (ikev2_build_idr(data, plain, IKEV2_PAYLOAD_AUTHENTICATION) ||
1221	    ikev2_build_auth(data, plain, IKEV2_PAYLOAD_NO_NEXT_PAYLOAD) ||
1222	    ikev2_build_encrypted(data->proposal.encr, data->proposal.integ,
1223				  &data->keys, 0, msg, plain,
1224				  IKEV2_PAYLOAD_IDr)) {
1225		wpabuf_free(plain);
1226		wpabuf_free(msg);
1227		return NULL;
1228	}
1229	wpabuf_free(plain);
1230
1231	wpa_hexdump_buf(MSG_MSGDUMP, "IKEV2: Sending message (SA_AUTH)", msg);
1232
1233	data->state = IKEV2_DONE;
1234
1235	return msg;
1236}
1237
1238
1239static struct wpabuf * ikev2_build_notify(struct ikev2_responder_data *data)
1240{
1241	struct wpabuf *msg;
1242
1243	msg = wpabuf_alloc(sizeof(struct ikev2_hdr) + 1000);
1244	if (msg == NULL)
1245		return NULL;
1246	if (data->last_msg == LAST_MSG_SA_AUTH) {
1247		/* HDR, SK{N} */
1248		struct wpabuf *plain = wpabuf_alloc(100);
1249		if (plain == NULL) {
1250			wpabuf_free(msg);
1251			return NULL;
1252		}
1253		ikev2_build_hdr(data, msg, IKE_SA_AUTH,
1254				IKEV2_PAYLOAD_ENCRYPTED, 1);
1255		if (ikev2_build_notification(data, plain,
1256					     IKEV2_PAYLOAD_NO_NEXT_PAYLOAD) ||
1257		    ikev2_build_encrypted(data->proposal.encr,
1258					  data->proposal.integ,
1259					  &data->keys, 0, msg, plain,
1260					  IKEV2_PAYLOAD_NOTIFICATION)) {
1261			wpabuf_free(plain);
1262			wpabuf_free(msg);
1263			return NULL;
1264		}
1265		data->state = IKEV2_FAILED;
1266	} else {
1267		/* HDR, N */
1268		ikev2_build_hdr(data, msg, IKE_SA_INIT,
1269				IKEV2_PAYLOAD_NOTIFICATION, 0);
1270		if (ikev2_build_notification(data, msg,
1271					     IKEV2_PAYLOAD_NO_NEXT_PAYLOAD)) {
1272			wpabuf_free(msg);
1273			return NULL;
1274		}
1275		data->state = SA_INIT;
1276	}
1277
1278	ikev2_update_hdr(msg);
1279
1280	wpa_hexdump_buf(MSG_MSGDUMP, "IKEV2: Sending message (Notification)",
1281			msg);
1282
1283	return msg;
1284}
1285
1286
1287struct wpabuf * ikev2_responder_build(struct ikev2_responder_data *data)
1288{
1289	switch (data->state) {
1290	case SA_INIT:
1291		return ikev2_build_sa_init(data);
1292	case SA_AUTH:
1293		return ikev2_build_sa_auth(data);
1294	case CHILD_SA:
1295		return NULL;
1296	case NOTIFY:
1297		return ikev2_build_notify(data);
1298	case IKEV2_DONE:
1299	case IKEV2_FAILED:
1300		return NULL;
1301	}
1302	return NULL;
1303}
1304