ikev2.c revision 8d520ff1dc2da35cdca849e982051b86468016d8
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 "crypto/dh_groups.h"
19#include "crypto/random.h"
20#include "ikev2.h"
21
22
23void ikev2_responder_deinit(struct ikev2_responder_data *data)
24{
25	ikev2_free_keys(&data->keys);
26	wpabuf_free(data->i_dh_public);
27	wpabuf_free(data->r_dh_private);
28	os_free(data->IDi);
29	os_free(data->IDr);
30	os_free(data->shared_secret);
31	wpabuf_free(data->i_sign_msg);
32	wpabuf_free(data->r_sign_msg);
33	os_free(data->key_pad);
34}
35
36
37static int ikev2_derive_keys(struct ikev2_responder_data *data)
38{
39	u8 *buf, *pos, *pad, skeyseed[IKEV2_MAX_HASH_LEN];
40	size_t buf_len, pad_len;
41	struct wpabuf *shared;
42	const struct ikev2_integ_alg *integ;
43	const struct ikev2_prf_alg *prf;
44	const struct ikev2_encr_alg *encr;
45	int ret;
46	const u8 *addr[2];
47	size_t len[2];
48
49	/* RFC 4306, Sect. 2.14 */
50
51	integ = ikev2_get_integ(data->proposal.integ);
52	prf = ikev2_get_prf(data->proposal.prf);
53	encr = ikev2_get_encr(data->proposal.encr);
54	if (integ == NULL || prf == NULL || encr == NULL) {
55		wpa_printf(MSG_INFO, "IKEV2: Unsupported proposal");
56		return -1;
57	}
58
59	shared = dh_derive_shared(data->i_dh_public, data->r_dh_private,
60				  data->dh);
61	if (shared == NULL)
62		return -1;
63
64	/* Construct Ni | Nr | SPIi | SPIr */
65
66	buf_len = data->i_nonce_len + data->r_nonce_len + 2 * IKEV2_SPI_LEN;
67	buf = os_malloc(buf_len);
68	if (buf == NULL) {
69		wpabuf_free(shared);
70		return -1;
71	}
72
73	pos = buf;
74	os_memcpy(pos, data->i_nonce, data->i_nonce_len);
75	pos += data->i_nonce_len;
76	os_memcpy(pos, data->r_nonce, data->r_nonce_len);
77	pos += data->r_nonce_len;
78	os_memcpy(pos, data->i_spi, IKEV2_SPI_LEN);
79	pos += IKEV2_SPI_LEN;
80	os_memcpy(pos, data->r_spi, IKEV2_SPI_LEN);
81#ifdef CCNS_PL
82#if __BYTE_ORDER == __LITTLE_ENDIAN
83	{
84		int i;
85		u8 *tmp = pos - IKEV2_SPI_LEN;
86		/* Incorrect byte re-ordering on little endian hosts.. */
87		for (i = 0; i < IKEV2_SPI_LEN; i++)
88			*tmp++ = data->i_spi[IKEV2_SPI_LEN - 1 - i];
89		for (i = 0; i < IKEV2_SPI_LEN; i++)
90			*tmp++ = data->r_spi[IKEV2_SPI_LEN - 1 - i];
91	}
92#endif
93#endif /* CCNS_PL */
94
95	/* SKEYSEED = prf(Ni | Nr, g^ir) */
96	/* Use zero-padding per RFC 4306, Sect. 2.14 */
97	pad_len = data->dh->prime_len - wpabuf_len(shared);
98#ifdef CCNS_PL
99	/* Shared secret is not zero-padded correctly */
100	pad_len = 0;
101#endif /* CCNS_PL */
102	pad = os_zalloc(pad_len ? pad_len : 1);
103	if (pad == NULL) {
104		wpabuf_free(shared);
105		os_free(buf);
106		return -1;
107	}
108
109	addr[0] = pad;
110	len[0] = pad_len;
111	addr[1] = wpabuf_head(shared);
112	len[1] = wpabuf_len(shared);
113	if (ikev2_prf_hash(prf->id, buf, data->i_nonce_len + data->r_nonce_len,
114			   2, addr, len, skeyseed) < 0) {
115		wpabuf_free(shared);
116		os_free(buf);
117		os_free(pad);
118		return -1;
119	}
120	os_free(pad);
121	wpabuf_free(shared);
122
123	/* DH parameters are not needed anymore, so free them */
124	wpabuf_free(data->i_dh_public);
125	data->i_dh_public = NULL;
126	wpabuf_free(data->r_dh_private);
127	data->r_dh_private = NULL;
128
129	wpa_hexdump_key(MSG_DEBUG, "IKEV2: SKEYSEED",
130			skeyseed, prf->hash_len);
131
132	ret = ikev2_derive_sk_keys(prf, integ, encr, skeyseed, buf, buf_len,
133				   &data->keys);
134	os_free(buf);
135	return ret;
136}
137
138
139static int ikev2_parse_transform(struct ikev2_proposal_data *prop,
140				 const u8 *pos, const u8 *end)
141{
142	int transform_len;
143	const struct ikev2_transform *t;
144	u16 transform_id;
145	const u8 *tend;
146
147	if (end - pos < (int) sizeof(*t)) {
148		wpa_printf(MSG_INFO, "IKEV2: Too short transform");
149		return -1;
150	}
151
152	t = (const struct ikev2_transform *) pos;
153	transform_len = WPA_GET_BE16(t->transform_length);
154	if (transform_len < (int) sizeof(*t) || pos + transform_len > end) {
155		wpa_printf(MSG_INFO, "IKEV2: Invalid transform length %d",
156			   transform_len);
157		return -1;
158	}
159	tend = pos + transform_len;
160
161	transform_id = WPA_GET_BE16(t->transform_id);
162
163	wpa_printf(MSG_DEBUG, "IKEV2:   Transform:");
164	wpa_printf(MSG_DEBUG, "IKEV2:     Type: %d  Transform Length: %d  "
165		   "Transform Type: %d  Transform ID: %d",
166		   t->type, transform_len, t->transform_type, transform_id);
167
168	if (t->type != 0 && t->type != 3) {
169		wpa_printf(MSG_INFO, "IKEV2: Unexpected Transform type");
170		return -1;
171	}
172
173	pos = (const u8 *) (t + 1);
174	if (pos < tend) {
175		wpa_hexdump(MSG_DEBUG, "IKEV2:     Transform Attributes",
176			    pos, tend - pos);
177	}
178
179	switch (t->transform_type) {
180	case IKEV2_TRANSFORM_ENCR:
181		if (ikev2_get_encr(transform_id)) {
182			if (transform_id == ENCR_AES_CBC) {
183				if (tend - pos != 4) {
184					wpa_printf(MSG_DEBUG, "IKEV2: No "
185						   "Transform Attr for AES");
186					break;
187				}
188#ifdef CCNS_PL
189				if (WPA_GET_BE16(pos) != 0x001d /* ?? */) {
190					wpa_printf(MSG_DEBUG, "IKEV2: Not a "
191						   "Key Size attribute for "
192						   "AES");
193					break;
194				}
195#else /* CCNS_PL */
196				if (WPA_GET_BE16(pos) != 0x800e) {
197					wpa_printf(MSG_DEBUG, "IKEV2: Not a "
198						   "Key Size attribute for "
199						   "AES");
200					break;
201				}
202#endif /* CCNS_PL */
203				if (WPA_GET_BE16(pos + 2) != 128) {
204					wpa_printf(MSG_DEBUG, "IKEV2: "
205						   "Unsupported AES key size "
206						   "%d bits",
207						   WPA_GET_BE16(pos + 2));
208					break;
209				}
210			}
211			prop->encr = transform_id;
212		}
213		break;
214	case IKEV2_TRANSFORM_PRF:
215		if (ikev2_get_prf(transform_id))
216			prop->prf = transform_id;
217		break;
218	case IKEV2_TRANSFORM_INTEG:
219		if (ikev2_get_integ(transform_id))
220			prop->integ = transform_id;
221		break;
222	case IKEV2_TRANSFORM_DH:
223		if (dh_groups_get(transform_id))
224			prop->dh = transform_id;
225		break;
226	}
227
228	return transform_len;
229}
230
231
232static int ikev2_parse_proposal(struct ikev2_proposal_data *prop,
233				const u8 *pos, const u8 *end)
234{
235	const u8 *pend, *ppos;
236	int proposal_len, i;
237	const struct ikev2_proposal *p;
238
239	if (end - pos < (int) sizeof(*p)) {
240		wpa_printf(MSG_INFO, "IKEV2: Too short proposal");
241		return -1;
242	}
243
244	/* FIX: AND processing if multiple proposals use the same # */
245
246	p = (const struct ikev2_proposal *) pos;
247	proposal_len = WPA_GET_BE16(p->proposal_length);
248	if (proposal_len < (int) sizeof(*p) || pos + proposal_len > end) {
249		wpa_printf(MSG_INFO, "IKEV2: Invalid proposal length %d",
250			   proposal_len);
251		return -1;
252	}
253	wpa_printf(MSG_DEBUG, "IKEV2: SAi1 Proposal # %d",
254		   p->proposal_num);
255	wpa_printf(MSG_DEBUG, "IKEV2:   Type: %d  Proposal Length: %d "
256		   " Protocol ID: %d",
257		   p->type, proposal_len, p->protocol_id);
258	wpa_printf(MSG_DEBUG, "IKEV2:   SPI Size: %d  Transforms: %d",
259		   p->spi_size, p->num_transforms);
260
261	if (p->type != 0 && p->type != 2) {
262		wpa_printf(MSG_INFO, "IKEV2: Unexpected Proposal type");
263		return -1;
264	}
265
266	if (p->protocol_id != IKEV2_PROTOCOL_IKE) {
267		wpa_printf(MSG_DEBUG, "IKEV2: Unexpected Protocol ID "
268			   "(only IKE allowed for EAP-IKEv2)");
269		return -1;
270	}
271
272	if (p->proposal_num != prop->proposal_num) {
273		if (p->proposal_num == prop->proposal_num + 1)
274			prop->proposal_num = p->proposal_num;
275		else {
276			wpa_printf(MSG_INFO, "IKEV2: Unexpected Proposal #");
277			return -1;
278		}
279	}
280
281	ppos = (const u8 *) (p + 1);
282	pend = pos + proposal_len;
283	if (ppos + p->spi_size > pend) {
284		wpa_printf(MSG_INFO, "IKEV2: Not enough room for SPI "
285			   "in proposal");
286		return -1;
287	}
288	if (p->spi_size) {
289		wpa_hexdump(MSG_DEBUG, "IKEV2:    SPI",
290			    ppos, p->spi_size);
291		ppos += p->spi_size;
292	}
293
294	/*
295	 * For initial IKE_SA negotiation, SPI Size MUST be zero; for
296	 * subsequent negotiations, it must be 8 for IKE. We only support
297	 * initial case for now.
298	 */
299	if (p->spi_size != 0) {
300		wpa_printf(MSG_INFO, "IKEV2: Unexpected SPI Size");
301		return -1;
302	}
303
304	if (p->num_transforms == 0) {
305		wpa_printf(MSG_INFO, "IKEV2: At least one transform required");
306		return -1;
307	}
308
309	for (i = 0; i < (int) p->num_transforms; i++) {
310		int tlen = ikev2_parse_transform(prop, ppos, pend);
311		if (tlen < 0)
312			return -1;
313		ppos += tlen;
314	}
315
316	if (ppos != pend) {
317		wpa_printf(MSG_INFO, "IKEV2: Unexpected data after "
318			   "transforms");
319		return -1;
320	}
321
322	return proposal_len;
323}
324
325
326static int ikev2_process_sai1(struct ikev2_responder_data *data,
327			      const u8 *sai1, size_t sai1_len)
328{
329	struct ikev2_proposal_data prop;
330	const u8 *pos, *end;
331	int found = 0;
332
333	/* Security Association Payloads: <Proposals> */
334
335	if (sai1 == NULL) {
336		wpa_printf(MSG_INFO, "IKEV2: SAi1 not received");
337		return -1;
338	}
339
340	os_memset(&prop, 0, sizeof(prop));
341	prop.proposal_num = 1;
342
343	pos = sai1;
344	end = sai1 + sai1_len;
345
346	while (pos < end) {
347		int plen;
348
349		prop.integ = -1;
350		prop.prf = -1;
351		prop.encr = -1;
352		prop.dh = -1;
353		plen = ikev2_parse_proposal(&prop, pos, end);
354		if (plen < 0)
355			return -1;
356
357		if (!found && prop.integ != -1 && prop.prf != -1 &&
358		    prop.encr != -1 && prop.dh != -1) {
359			os_memcpy(&data->proposal, &prop, sizeof(prop));
360			data->dh = dh_groups_get(prop.dh);
361			found = 1;
362		}
363
364		pos += plen;
365	}
366
367	if (pos != end) {
368		wpa_printf(MSG_INFO, "IKEV2: Unexpected data after proposals");
369		return -1;
370	}
371
372	if (!found) {
373		wpa_printf(MSG_INFO, "IKEV2: No acceptable proposal found");
374		return -1;
375	}
376
377	wpa_printf(MSG_DEBUG, "IKEV2: Accepted proposal #%d: ENCR:%d PRF:%d "
378		   "INTEG:%d D-H:%d", data->proposal.proposal_num,
379		   data->proposal.encr, data->proposal.prf,
380		   data->proposal.integ, data->proposal.dh);
381
382	return 0;
383}
384
385
386static int ikev2_process_kei(struct ikev2_responder_data *data,
387			     const u8 *kei, size_t kei_len)
388{
389	u16 group;
390
391	/*
392	 * Key Exchange Payload:
393	 * DH Group # (16 bits)
394	 * RESERVED (16 bits)
395	 * Key Exchange Data (Diffie-Hellman public value)
396	 */
397
398	if (kei == NULL) {
399		wpa_printf(MSG_INFO, "IKEV2: KEi not received");
400		return -1;
401	}
402
403	if (kei_len < 4 + 96) {
404		wpa_printf(MSG_INFO, "IKEV2: Too show Key Exchange Payload");
405		return -1;
406	}
407
408	group = WPA_GET_BE16(kei);
409	wpa_printf(MSG_DEBUG, "IKEV2: KEi DH Group #%u", group);
410
411	if (group != data->proposal.dh) {
412		wpa_printf(MSG_DEBUG, "IKEV2: KEi DH Group #%u does not match "
413			   "with the selected proposal (%u)",
414			   group, data->proposal.dh);
415		/* Reject message with Notify payload of type
416		 * INVALID_KE_PAYLOAD (RFC 4306, Sect. 3.4) */
417		data->error_type = INVALID_KE_PAYLOAD;
418		data->state = NOTIFY;
419		return -1;
420	}
421
422	if (data->dh == NULL) {
423		wpa_printf(MSG_INFO, "IKEV2: Unsupported DH group");
424		return -1;
425	}
426
427	/* RFC 4306, Section 3.4:
428	 * The length of DH public value MUST be equal to the lenght of the
429	 * prime modulus.
430	 */
431	if (kei_len - 4 != data->dh->prime_len) {
432		wpa_printf(MSG_INFO, "IKEV2: Invalid DH public value length "
433			   "%ld (expected %ld)",
434			   (long) (kei_len - 4), (long) data->dh->prime_len);
435		return -1;
436	}
437
438	wpabuf_free(data->i_dh_public);
439	data->i_dh_public = wpabuf_alloc(kei_len - 4);
440	if (data->i_dh_public == NULL)
441		return -1;
442	wpabuf_put_data(data->i_dh_public, kei + 4, kei_len - 4);
443
444	wpa_hexdump_buf(MSG_DEBUG, "IKEV2: KEi Diffie-Hellman Public Value",
445			data->i_dh_public);
446
447	return 0;
448}
449
450
451static int ikev2_process_ni(struct ikev2_responder_data *data,
452			    const u8 *ni, size_t ni_len)
453{
454	if (ni == NULL) {
455		wpa_printf(MSG_INFO, "IKEV2: Ni not received");
456		return -1;
457	}
458
459	if (ni_len < IKEV2_NONCE_MIN_LEN || ni_len > IKEV2_NONCE_MAX_LEN) {
460		wpa_printf(MSG_INFO, "IKEV2: Invalid Ni length %ld",
461		           (long) ni_len);
462		return -1;
463	}
464
465#ifdef CCNS_PL
466	/* Zeros are removed incorrectly from the beginning of the nonces */
467	while (ni_len > 1 && *ni == 0) {
468		ni_len--;
469		ni++;
470	}
471#endif /* CCNS_PL */
472
473	data->i_nonce_len = ni_len;
474	os_memcpy(data->i_nonce, ni, ni_len);
475	wpa_hexdump(MSG_MSGDUMP, "IKEV2: Ni",
476		    data->i_nonce, data->i_nonce_len);
477
478	return 0;
479}
480
481
482static int ikev2_process_sa_init(struct ikev2_responder_data *data,
483				 const struct ikev2_hdr *hdr,
484				 struct ikev2_payloads *pl)
485{
486	if (ikev2_process_sai1(data, pl->sa, pl->sa_len) < 0 ||
487	    ikev2_process_kei(data, pl->ke, pl->ke_len) < 0 ||
488	    ikev2_process_ni(data, pl->nonce, pl->nonce_len) < 0)
489		return -1;
490
491	os_memcpy(data->i_spi, hdr->i_spi, IKEV2_SPI_LEN);
492
493	return 0;
494}
495
496
497static int ikev2_process_idi(struct ikev2_responder_data *data,
498			     const u8 *idi, size_t idi_len)
499{
500	u8 id_type;
501
502	if (idi == NULL) {
503		wpa_printf(MSG_INFO, "IKEV2: No IDi received");
504		return -1;
505	}
506
507	if (idi_len < 4) {
508		wpa_printf(MSG_INFO, "IKEV2: Too short IDi payload");
509		return -1;
510	}
511
512	id_type = idi[0];
513	idi += 4;
514	idi_len -= 4;
515
516	wpa_printf(MSG_DEBUG, "IKEV2: IDi ID Type %d", id_type);
517	wpa_hexdump_ascii(MSG_DEBUG, "IKEV2: IDi", idi, idi_len);
518	os_free(data->IDi);
519	data->IDi = os_malloc(idi_len);
520	if (data->IDi == NULL)
521		return -1;
522	os_memcpy(data->IDi, idi, idi_len);
523	data->IDi_len = idi_len;
524	data->IDi_type = id_type;
525
526	return 0;
527}
528
529
530static int ikev2_process_cert(struct ikev2_responder_data *data,
531			      const u8 *cert, size_t cert_len)
532{
533	u8 cert_encoding;
534
535	if (cert == NULL) {
536		if (data->peer_auth == PEER_AUTH_CERT) {
537			wpa_printf(MSG_INFO, "IKEV2: No Certificate received");
538			return -1;
539		}
540		return 0;
541	}
542
543	if (cert_len < 1) {
544		wpa_printf(MSG_INFO, "IKEV2: No Cert Encoding field");
545		return -1;
546	}
547
548	cert_encoding = cert[0];
549	cert++;
550	cert_len--;
551
552	wpa_printf(MSG_DEBUG, "IKEV2: Cert Encoding %d", cert_encoding);
553	wpa_hexdump(MSG_MSGDUMP, "IKEV2: Certificate Data", cert, cert_len);
554
555	/* TODO: validate certificate */
556
557	return 0;
558}
559
560
561static int ikev2_process_auth_cert(struct ikev2_responder_data *data,
562				   u8 method, const u8 *auth, size_t auth_len)
563{
564	if (method != AUTH_RSA_SIGN) {
565		wpa_printf(MSG_INFO, "IKEV2: Unsupported authentication "
566			   "method %d", method);
567		return -1;
568	}
569
570	/* TODO: validate AUTH */
571	return 0;
572}
573
574
575static int ikev2_process_auth_secret(struct ikev2_responder_data *data,
576				     u8 method, const u8 *auth,
577				     size_t auth_len)
578{
579	u8 auth_data[IKEV2_MAX_HASH_LEN];
580	const struct ikev2_prf_alg *prf;
581
582	if (method != AUTH_SHARED_KEY_MIC) {
583		wpa_printf(MSG_INFO, "IKEV2: Unsupported authentication "
584			   "method %d", method);
585		return -1;
586	}
587
588	/* msg | Nr | prf(SK_pi,IDi') */
589	if (ikev2_derive_auth_data(data->proposal.prf, data->i_sign_msg,
590				   data->IDi, data->IDi_len, data->IDi_type,
591				   &data->keys, 1, data->shared_secret,
592				   data->shared_secret_len,
593				   data->r_nonce, data->r_nonce_len,
594				   data->key_pad, data->key_pad_len,
595				   auth_data) < 0) {
596		wpa_printf(MSG_INFO, "IKEV2: Could not derive AUTH data");
597		return -1;
598	}
599
600	wpabuf_free(data->i_sign_msg);
601	data->i_sign_msg = NULL;
602
603	prf = ikev2_get_prf(data->proposal.prf);
604	if (prf == NULL)
605		return -1;
606
607	if (auth_len != prf->hash_len ||
608	    os_memcmp(auth, auth_data, auth_len) != 0) {
609		wpa_printf(MSG_INFO, "IKEV2: Invalid Authentication Data");
610		wpa_hexdump(MSG_DEBUG, "IKEV2: Received Authentication Data",
611			    auth, auth_len);
612		wpa_hexdump(MSG_DEBUG, "IKEV2: Expected Authentication Data",
613			    auth_data, prf->hash_len);
614		data->error_type = AUTHENTICATION_FAILED;
615		data->state = NOTIFY;
616		return -1;
617	}
618
619	wpa_printf(MSG_DEBUG, "IKEV2: Server authenticated successfully "
620		   "using shared keys");
621
622	return 0;
623}
624
625
626static int ikev2_process_auth(struct ikev2_responder_data *data,
627			      const u8 *auth, size_t auth_len)
628{
629	u8 auth_method;
630
631	if (auth == NULL) {
632		wpa_printf(MSG_INFO, "IKEV2: No Authentication Payload");
633		return -1;
634	}
635
636	if (auth_len < 4) {
637		wpa_printf(MSG_INFO, "IKEV2: Too short Authentication "
638			   "Payload");
639		return -1;
640	}
641
642	auth_method = auth[0];
643	auth += 4;
644	auth_len -= 4;
645
646	wpa_printf(MSG_DEBUG, "IKEV2: Auth Method %d", auth_method);
647	wpa_hexdump(MSG_MSGDUMP, "IKEV2: Authentication Data", auth, auth_len);
648
649	switch (data->peer_auth) {
650	case PEER_AUTH_CERT:
651		return ikev2_process_auth_cert(data, auth_method, auth,
652					       auth_len);
653	case PEER_AUTH_SECRET:
654		return ikev2_process_auth_secret(data, auth_method, auth,
655						 auth_len);
656	}
657
658	return -1;
659}
660
661
662static int ikev2_process_sa_auth_decrypted(struct ikev2_responder_data *data,
663					   u8 next_payload,
664					   u8 *payload, size_t payload_len)
665{
666	struct ikev2_payloads pl;
667
668	wpa_printf(MSG_DEBUG, "IKEV2: Processing decrypted payloads");
669
670	if (ikev2_parse_payloads(&pl, next_payload, payload, payload +
671				 payload_len) < 0) {
672		wpa_printf(MSG_INFO, "IKEV2: Failed to parse decrypted "
673			   "payloads");
674		return -1;
675	}
676
677	if (ikev2_process_idi(data, pl.idi, pl.idi_len) < 0 ||
678	    ikev2_process_cert(data, pl.cert, pl.cert_len) < 0 ||
679	    ikev2_process_auth(data, pl.auth, pl.auth_len) < 0)
680		return -1;
681
682	return 0;
683}
684
685
686static int ikev2_process_sa_auth(struct ikev2_responder_data *data,
687				 const struct ikev2_hdr *hdr,
688				 struct ikev2_payloads *pl)
689{
690	u8 *decrypted;
691	size_t decrypted_len;
692	int ret;
693
694	decrypted = ikev2_decrypt_payload(data->proposal.encr,
695					  data->proposal.integ,
696					  &data->keys, 1, hdr, pl->encrypted,
697					  pl->encrypted_len, &decrypted_len);
698	if (decrypted == NULL)
699		return -1;
700
701	ret = ikev2_process_sa_auth_decrypted(data, pl->encr_next_payload,
702					      decrypted, decrypted_len);
703	os_free(decrypted);
704
705	return ret;
706}
707
708
709static int ikev2_validate_rx_state(struct ikev2_responder_data *data,
710				   u8 exchange_type, u32 message_id)
711{
712	switch (data->state) {
713	case SA_INIT:
714		/* Expect to receive IKE_SA_INIT: HDR, SAi1, KEi, Ni */
715		if (exchange_type != IKE_SA_INIT) {
716			wpa_printf(MSG_INFO, "IKEV2: Unexpected Exchange Type "
717				   "%u in SA_INIT state", exchange_type);
718			return -1;
719		}
720		if (message_id != 0) {
721			wpa_printf(MSG_INFO, "IKEV2: Unexpected Message ID %u "
722				   "in SA_INIT state", message_id);
723			return -1;
724		}
725		break;
726	case SA_AUTH:
727		/* Expect to receive IKE_SA_AUTH:
728		 * HDR, SK {IDi, [CERT,] [CERTREQ,] [IDr,]
729		 *	AUTH, SAi2, TSi, TSr}
730		 */
731		if (exchange_type != IKE_SA_AUTH) {
732			wpa_printf(MSG_INFO, "IKEV2: Unexpected Exchange Type "
733				   "%u in SA_AUTH state", exchange_type);
734			return -1;
735		}
736		if (message_id != 1) {
737			wpa_printf(MSG_INFO, "IKEV2: Unexpected Message ID %u "
738				   "in SA_AUTH state", message_id);
739			return -1;
740		}
741		break;
742	case CHILD_SA:
743		if (exchange_type != CREATE_CHILD_SA) {
744			wpa_printf(MSG_INFO, "IKEV2: Unexpected Exchange Type "
745				   "%u in CHILD_SA state", exchange_type);
746			return -1;
747		}
748		if (message_id != 2) {
749			wpa_printf(MSG_INFO, "IKEV2: Unexpected Message ID %u "
750				   "in CHILD_SA state", message_id);
751			return -1;
752		}
753		break;
754	case NOTIFY:
755	case IKEV2_DONE:
756	case IKEV2_FAILED:
757		return -1;
758	}
759
760	return 0;
761}
762
763
764int ikev2_responder_process(struct ikev2_responder_data *data,
765			    const struct wpabuf *buf)
766{
767	const struct ikev2_hdr *hdr;
768	u32 length, message_id;
769	const u8 *pos, *end;
770	struct ikev2_payloads pl;
771
772	wpa_printf(MSG_MSGDUMP, "IKEV2: Received message (len %lu)",
773		   (unsigned long) wpabuf_len(buf));
774
775	if (wpabuf_len(buf) < sizeof(*hdr)) {
776		wpa_printf(MSG_INFO, "IKEV2: Too short frame to include HDR");
777		return -1;
778	}
779
780	data->error_type = 0;
781	hdr = (const struct ikev2_hdr *) wpabuf_head(buf);
782	end = wpabuf_head_u8(buf) + wpabuf_len(buf);
783	message_id = WPA_GET_BE32(hdr->message_id);
784	length = WPA_GET_BE32(hdr->length);
785
786	wpa_hexdump(MSG_DEBUG, "IKEV2:   IKE_SA Initiator's SPI",
787		    hdr->i_spi, IKEV2_SPI_LEN);
788	wpa_hexdump(MSG_DEBUG, "IKEV2:   IKE_SA Responder's SPI",
789		    hdr->r_spi, IKEV2_SPI_LEN);
790	wpa_printf(MSG_DEBUG, "IKEV2:   Next Payload: %u  Version: 0x%x  "
791		   "Exchange Type: %u",
792		   hdr->next_payload, hdr->version, hdr->exchange_type);
793	wpa_printf(MSG_DEBUG, "IKEV2:   Message ID: %u  Length: %u",
794		   message_id, length);
795
796	if (hdr->version != IKEV2_VERSION) {
797		wpa_printf(MSG_INFO, "IKEV2: Unsupported HDR version 0x%x "
798			   "(expected 0x%x)", hdr->version, IKEV2_VERSION);
799		return -1;
800	}
801
802	if (length != wpabuf_len(buf)) {
803		wpa_printf(MSG_INFO, "IKEV2: Invalid length (HDR: %lu != "
804			   "RX: %lu)", (unsigned long) length,
805			   (unsigned long) wpabuf_len(buf));
806		return -1;
807	}
808
809	if (ikev2_validate_rx_state(data, hdr->exchange_type, message_id) < 0)
810		return -1;
811
812	if ((hdr->flags & (IKEV2_HDR_INITIATOR | IKEV2_HDR_RESPONSE)) !=
813	    IKEV2_HDR_INITIATOR) {
814		wpa_printf(MSG_INFO, "IKEV2: Unexpected Flags value 0x%x",
815			   hdr->flags);
816		return -1;
817	}
818
819	if (data->state != SA_INIT) {
820		if (os_memcmp(data->i_spi, hdr->i_spi, IKEV2_SPI_LEN) != 0) {
821			wpa_printf(MSG_INFO, "IKEV2: Unexpected IKE_SA "
822				   "Initiator's SPI");
823			return -1;
824		}
825		if (os_memcmp(data->r_spi, hdr->r_spi, IKEV2_SPI_LEN) != 0) {
826			wpa_printf(MSG_INFO, "IKEV2: Unexpected IKE_SA "
827				   "Responder's SPI");
828			return -1;
829		}
830	}
831
832	pos = (const u8 *) (hdr + 1);
833	if (ikev2_parse_payloads(&pl, hdr->next_payload, pos, end) < 0)
834		return -1;
835
836	if (data->state == SA_INIT) {
837		data->last_msg = LAST_MSG_SA_INIT;
838		if (ikev2_process_sa_init(data, hdr, &pl) < 0) {
839			if (data->state == NOTIFY)
840				return 0;
841			return -1;
842		}
843		wpabuf_free(data->i_sign_msg);
844		data->i_sign_msg = wpabuf_dup(buf);
845	}
846
847	if (data->state == SA_AUTH) {
848		data->last_msg = LAST_MSG_SA_AUTH;
849		if (ikev2_process_sa_auth(data, hdr, &pl) < 0) {
850			if (data->state == NOTIFY)
851				return 0;
852			return -1;
853		}
854	}
855
856	return 0;
857}
858
859
860static void ikev2_build_hdr(struct ikev2_responder_data *data,
861			    struct wpabuf *msg, u8 exchange_type,
862			    u8 next_payload, u32 message_id)
863{
864	struct ikev2_hdr *hdr;
865
866	wpa_printf(MSG_DEBUG, "IKEV2: Adding HDR");
867
868	/* HDR - RFC 4306, Sect. 3.1 */
869	hdr = wpabuf_put(msg, sizeof(*hdr));
870	os_memcpy(hdr->i_spi, data->i_spi, IKEV2_SPI_LEN);
871	os_memcpy(hdr->r_spi, data->r_spi, IKEV2_SPI_LEN);
872	hdr->next_payload = next_payload;
873	hdr->version = IKEV2_VERSION;
874	hdr->exchange_type = exchange_type;
875	hdr->flags = IKEV2_HDR_RESPONSE;
876	WPA_PUT_BE32(hdr->message_id, message_id);
877}
878
879
880static int ikev2_build_sar1(struct ikev2_responder_data *data,
881			    struct wpabuf *msg, u8 next_payload)
882{
883	struct ikev2_payload_hdr *phdr;
884	size_t plen;
885	struct ikev2_proposal *p;
886	struct ikev2_transform *t;
887
888	wpa_printf(MSG_DEBUG, "IKEV2: Adding SAr1 payload");
889
890	/* SAr1 - RFC 4306, Sect. 2.7 and 3.3 */
891	phdr = wpabuf_put(msg, sizeof(*phdr));
892	phdr->next_payload = next_payload;
893	phdr->flags = 0;
894
895	p = wpabuf_put(msg, sizeof(*p));
896#ifdef CCNS_PL
897	/* Seems to require that the Proposal # is 1 even though RFC 4306
898	 * Sect 3.3.1 has following requirement "When a proposal is accepted,
899	 * all of the proposal numbers in the SA payload MUST be the same and
900	 * MUST match the number on the proposal sent that was accepted.".
901	 */
902	p->proposal_num = 1;
903#else /* CCNS_PL */
904	p->proposal_num = data->proposal.proposal_num;
905#endif /* CCNS_PL */
906	p->protocol_id = IKEV2_PROTOCOL_IKE;
907	p->num_transforms = 4;
908
909	t = wpabuf_put(msg, sizeof(*t));
910	t->type = 3;
911	t->transform_type = IKEV2_TRANSFORM_ENCR;
912	WPA_PUT_BE16(t->transform_id, data->proposal.encr);
913	if (data->proposal.encr == ENCR_AES_CBC) {
914		/* Transform Attribute: Key Len = 128 bits */
915#ifdef CCNS_PL
916		wpabuf_put_be16(msg, 0x001d); /* ?? */
917#else /* CCNS_PL */
918		wpabuf_put_be16(msg, 0x800e); /* AF=1, AttrType=14 */
919#endif /* CCNS_PL */
920		wpabuf_put_be16(msg, 128); /* 128-bit key */
921	}
922	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) t;
923	WPA_PUT_BE16(t->transform_length, plen);
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_PRF;
929	WPA_PUT_BE16(t->transform_id, data->proposal.prf);
930
931	t = wpabuf_put(msg, sizeof(*t));
932	t->type = 3;
933	WPA_PUT_BE16(t->transform_length, sizeof(*t));
934	t->transform_type = IKEV2_TRANSFORM_INTEG;
935	WPA_PUT_BE16(t->transform_id, data->proposal.integ);
936
937	t = wpabuf_put(msg, sizeof(*t));
938	WPA_PUT_BE16(t->transform_length, sizeof(*t));
939	t->transform_type = IKEV2_TRANSFORM_DH;
940	WPA_PUT_BE16(t->transform_id, data->proposal.dh);
941
942	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) p;
943	WPA_PUT_BE16(p->proposal_length, plen);
944
945	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
946	WPA_PUT_BE16(phdr->payload_length, plen);
947
948	return 0;
949}
950
951
952static int ikev2_build_ker(struct ikev2_responder_data *data,
953			   struct wpabuf *msg, u8 next_payload)
954{
955	struct ikev2_payload_hdr *phdr;
956	size_t plen;
957	struct wpabuf *pv;
958
959	wpa_printf(MSG_DEBUG, "IKEV2: Adding KEr payload");
960
961	pv = dh_init(data->dh, &data->r_dh_private);
962	if (pv == NULL) {
963		wpa_printf(MSG_DEBUG, "IKEV2: Failed to initialize DH");
964		return -1;
965	}
966
967	/* KEr - RFC 4306, Sect. 3.4 */
968	phdr = wpabuf_put(msg, sizeof(*phdr));
969	phdr->next_payload = next_payload;
970	phdr->flags = 0;
971
972	wpabuf_put_be16(msg, data->proposal.dh); /* DH Group # */
973	wpabuf_put(msg, 2); /* RESERVED */
974	/*
975	 * RFC 4306, Sect. 3.4: possible zero padding for public value to
976	 * match the length of the prime.
977	 */
978	wpabuf_put(msg, data->dh->prime_len - wpabuf_len(pv));
979	wpabuf_put_buf(msg, pv);
980	wpabuf_free(pv);
981
982	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
983	WPA_PUT_BE16(phdr->payload_length, plen);
984	return 0;
985}
986
987
988static int ikev2_build_nr(struct ikev2_responder_data *data,
989			  struct wpabuf *msg, u8 next_payload)
990{
991	struct ikev2_payload_hdr *phdr;
992	size_t plen;
993
994	wpa_printf(MSG_DEBUG, "IKEV2: Adding Nr payload");
995
996	/* Nr - RFC 4306, Sect. 3.9 */
997	phdr = wpabuf_put(msg, sizeof(*phdr));
998	phdr->next_payload = next_payload;
999	phdr->flags = 0;
1000	wpabuf_put_data(msg, data->r_nonce, data->r_nonce_len);
1001	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
1002	WPA_PUT_BE16(phdr->payload_length, plen);
1003	return 0;
1004}
1005
1006
1007static int ikev2_build_idr(struct ikev2_responder_data *data,
1008			   struct wpabuf *msg, u8 next_payload)
1009{
1010	struct ikev2_payload_hdr *phdr;
1011	size_t plen;
1012
1013	wpa_printf(MSG_DEBUG, "IKEV2: Adding IDr payload");
1014
1015	if (data->IDr == NULL) {
1016		wpa_printf(MSG_INFO, "IKEV2: No IDr available");
1017		return -1;
1018	}
1019
1020	/* IDr - RFC 4306, Sect. 3.5 */
1021	phdr = wpabuf_put(msg, sizeof(*phdr));
1022	phdr->next_payload = next_payload;
1023	phdr->flags = 0;
1024	wpabuf_put_u8(msg, ID_KEY_ID);
1025	wpabuf_put(msg, 3); /* RESERVED */
1026	wpabuf_put_data(msg, data->IDr, data->IDr_len);
1027	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
1028	WPA_PUT_BE16(phdr->payload_length, plen);
1029	return 0;
1030}
1031
1032
1033static int ikev2_build_auth(struct ikev2_responder_data *data,
1034			    struct wpabuf *msg, u8 next_payload)
1035{
1036	struct ikev2_payload_hdr *phdr;
1037	size_t plen;
1038	const struct ikev2_prf_alg *prf;
1039
1040	wpa_printf(MSG_DEBUG, "IKEV2: Adding AUTH payload");
1041
1042	prf = ikev2_get_prf(data->proposal.prf);
1043	if (prf == NULL)
1044		return -1;
1045
1046	/* Authentication - RFC 4306, Sect. 3.8 */
1047	phdr = wpabuf_put(msg, sizeof(*phdr));
1048	phdr->next_payload = next_payload;
1049	phdr->flags = 0;
1050	wpabuf_put_u8(msg, AUTH_SHARED_KEY_MIC);
1051	wpabuf_put(msg, 3); /* RESERVED */
1052
1053	/* msg | Ni | prf(SK_pr,IDr') */
1054	if (ikev2_derive_auth_data(data->proposal.prf, data->r_sign_msg,
1055				   data->IDr, data->IDr_len, ID_KEY_ID,
1056				   &data->keys, 0, data->shared_secret,
1057				   data->shared_secret_len,
1058				   data->i_nonce, data->i_nonce_len,
1059				   data->key_pad, data->key_pad_len,
1060				   wpabuf_put(msg, prf->hash_len)) < 0) {
1061		wpa_printf(MSG_INFO, "IKEV2: Could not derive AUTH data");
1062		return -1;
1063	}
1064	wpabuf_free(data->r_sign_msg);
1065	data->r_sign_msg = NULL;
1066
1067	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
1068	WPA_PUT_BE16(phdr->payload_length, plen);
1069	return 0;
1070}
1071
1072
1073static int ikev2_build_notification(struct ikev2_responder_data *data,
1074				    struct wpabuf *msg, u8 next_payload)
1075{
1076	struct ikev2_payload_hdr *phdr;
1077	size_t plen;
1078
1079	wpa_printf(MSG_DEBUG, "IKEV2: Adding Notification payload");
1080
1081	if (data->error_type == 0) {
1082		wpa_printf(MSG_INFO, "IKEV2: No Notify Message Type "
1083			   "available");
1084		return -1;
1085	}
1086
1087	/* Notify - RFC 4306, Sect. 3.10 */
1088	phdr = wpabuf_put(msg, sizeof(*phdr));
1089	phdr->next_payload = next_payload;
1090	phdr->flags = 0;
1091#ifdef CCNS_PL
1092	wpabuf_put_u8(msg, 1); /* Protocol ID: IKE_SA notification */
1093#else /* CCNS_PL */
1094	wpabuf_put_u8(msg, 0); /* Protocol ID: no existing SA */
1095#endif /* CCNS_PL */
1096	wpabuf_put_u8(msg, 0); /* SPI Size */
1097	wpabuf_put_be16(msg, data->error_type);
1098
1099	switch (data->error_type) {
1100	case INVALID_KE_PAYLOAD:
1101		if (data->proposal.dh == -1) {
1102			wpa_printf(MSG_INFO, "IKEV2: No DH Group selected for "
1103				   "INVALID_KE_PAYLOAD notifications");
1104			return -1;
1105		}
1106		wpabuf_put_be16(msg, data->proposal.dh);
1107		wpa_printf(MSG_DEBUG, "IKEV2: INVALID_KE_PAYLOAD - request "
1108			   "DH Group #%d", data->proposal.dh);
1109		break;
1110	case AUTHENTICATION_FAILED:
1111		/* no associated data */
1112		break;
1113	default:
1114		wpa_printf(MSG_INFO, "IKEV2: Unsupported Notify Message Type "
1115			   "%d", data->error_type);
1116		return -1;
1117	}
1118
1119	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
1120	WPA_PUT_BE16(phdr->payload_length, plen);
1121	return 0;
1122}
1123
1124
1125static struct wpabuf * ikev2_build_sa_init(struct ikev2_responder_data *data)
1126{
1127	struct wpabuf *msg;
1128
1129	/* build IKE_SA_INIT: HDR, SAr1, KEr, Nr, [CERTREQ], [SK{IDr}] */
1130
1131	if (os_get_random(data->r_spi, IKEV2_SPI_LEN))
1132		return NULL;
1133	wpa_hexdump(MSG_DEBUG, "IKEV2: IKE_SA Responder's SPI",
1134		    data->r_spi, IKEV2_SPI_LEN);
1135
1136	data->r_nonce_len = IKEV2_NONCE_MIN_LEN;
1137	if (random_get_bytes(data->r_nonce, data->r_nonce_len))
1138		return NULL;
1139#ifdef CCNS_PL
1140	/* Zeros are removed incorrectly from the beginning of the nonces in
1141	 * key derivation; as a workaround, make sure Nr does not start with
1142	 * zero.. */
1143	if (data->r_nonce[0] == 0)
1144		data->r_nonce[0] = 1;
1145#endif /* CCNS_PL */
1146	wpa_hexdump(MSG_DEBUG, "IKEV2: Nr", data->r_nonce, data->r_nonce_len);
1147
1148	msg = wpabuf_alloc(sizeof(struct ikev2_hdr) + data->IDr_len + 1500);
1149	if (msg == NULL)
1150		return NULL;
1151
1152	ikev2_build_hdr(data, msg, IKE_SA_INIT, IKEV2_PAYLOAD_SA, 0);
1153	if (ikev2_build_sar1(data, msg, IKEV2_PAYLOAD_KEY_EXCHANGE) ||
1154	    ikev2_build_ker(data, msg, IKEV2_PAYLOAD_NONCE) ||
1155	    ikev2_build_nr(data, msg, data->peer_auth == PEER_AUTH_SECRET ?
1156			   IKEV2_PAYLOAD_ENCRYPTED :
1157			   IKEV2_PAYLOAD_NO_NEXT_PAYLOAD)) {
1158		wpabuf_free(msg);
1159		return NULL;
1160	}
1161
1162	if (ikev2_derive_keys(data)) {
1163		wpabuf_free(msg);
1164		return NULL;
1165	}
1166
1167	if (data->peer_auth == PEER_AUTH_CERT) {
1168		/* TODO: CERTREQ with SHA-1 hashes of Subject Public Key Info
1169		 * for trust agents */
1170	}
1171
1172	if (data->peer_auth == PEER_AUTH_SECRET) {
1173		struct wpabuf *plain = wpabuf_alloc(data->IDr_len + 1000);
1174		if (plain == NULL) {
1175			wpabuf_free(msg);
1176			return NULL;
1177		}
1178		if (ikev2_build_idr(data, plain,
1179				    IKEV2_PAYLOAD_NO_NEXT_PAYLOAD) ||
1180		    ikev2_build_encrypted(data->proposal.encr,
1181					  data->proposal.integ,
1182					  &data->keys, 0, msg, plain,
1183					  IKEV2_PAYLOAD_IDr)) {
1184			wpabuf_free(plain);
1185			wpabuf_free(msg);
1186			return NULL;
1187		}
1188		wpabuf_free(plain);
1189	}
1190
1191	ikev2_update_hdr(msg);
1192
1193	wpa_hexdump_buf(MSG_MSGDUMP, "IKEV2: Sending message (SA_INIT)", msg);
1194
1195	data->state = SA_AUTH;
1196
1197	wpabuf_free(data->r_sign_msg);
1198	data->r_sign_msg = wpabuf_dup(msg);
1199
1200	return msg;
1201}
1202
1203
1204static struct wpabuf * ikev2_build_sa_auth(struct ikev2_responder_data *data)
1205{
1206	struct wpabuf *msg, *plain;
1207
1208	/* build IKE_SA_AUTH: HDR, SK {IDr, [CERT,] AUTH} */
1209
1210	msg = wpabuf_alloc(sizeof(struct ikev2_hdr) + data->IDr_len + 1000);
1211	if (msg == NULL)
1212		return NULL;
1213	ikev2_build_hdr(data, msg, IKE_SA_AUTH, IKEV2_PAYLOAD_ENCRYPTED, 1);
1214
1215	plain = wpabuf_alloc(data->IDr_len + 1000);
1216	if (plain == NULL) {
1217		wpabuf_free(msg);
1218		return NULL;
1219	}
1220
1221	if (ikev2_build_idr(data, plain, IKEV2_PAYLOAD_AUTHENTICATION) ||
1222	    ikev2_build_auth(data, plain, IKEV2_PAYLOAD_NO_NEXT_PAYLOAD) ||
1223	    ikev2_build_encrypted(data->proposal.encr, data->proposal.integ,
1224				  &data->keys, 0, msg, plain,
1225				  IKEV2_PAYLOAD_IDr)) {
1226		wpabuf_free(plain);
1227		wpabuf_free(msg);
1228		return NULL;
1229	}
1230	wpabuf_free(plain);
1231
1232	wpa_hexdump_buf(MSG_MSGDUMP, "IKEV2: Sending message (SA_AUTH)", msg);
1233
1234	data->state = IKEV2_DONE;
1235
1236	return msg;
1237}
1238
1239
1240static struct wpabuf * ikev2_build_notify(struct ikev2_responder_data *data)
1241{
1242	struct wpabuf *msg;
1243
1244	msg = wpabuf_alloc(sizeof(struct ikev2_hdr) + 1000);
1245	if (msg == NULL)
1246		return NULL;
1247	if (data->last_msg == LAST_MSG_SA_AUTH) {
1248		/* HDR, SK{N} */
1249		struct wpabuf *plain = wpabuf_alloc(100);
1250		if (plain == NULL) {
1251			wpabuf_free(msg);
1252			return NULL;
1253		}
1254		ikev2_build_hdr(data, msg, IKE_SA_AUTH,
1255				IKEV2_PAYLOAD_ENCRYPTED, 1);
1256		if (ikev2_build_notification(data, plain,
1257					     IKEV2_PAYLOAD_NO_NEXT_PAYLOAD) ||
1258		    ikev2_build_encrypted(data->proposal.encr,
1259					  data->proposal.integ,
1260					  &data->keys, 0, msg, plain,
1261					  IKEV2_PAYLOAD_NOTIFICATION)) {
1262			wpabuf_free(plain);
1263			wpabuf_free(msg);
1264			return NULL;
1265		}
1266		data->state = IKEV2_FAILED;
1267	} else {
1268		/* HDR, N */
1269		ikev2_build_hdr(data, msg, IKE_SA_INIT,
1270				IKEV2_PAYLOAD_NOTIFICATION, 0);
1271		if (ikev2_build_notification(data, msg,
1272					     IKEV2_PAYLOAD_NO_NEXT_PAYLOAD)) {
1273			wpabuf_free(msg);
1274			return NULL;
1275		}
1276		data->state = SA_INIT;
1277	}
1278
1279	ikev2_update_hdr(msg);
1280
1281	wpa_hexdump_buf(MSG_MSGDUMP, "IKEV2: Sending message (Notification)",
1282			msg);
1283
1284	return msg;
1285}
1286
1287
1288struct wpabuf * ikev2_responder_build(struct ikev2_responder_data *data)
1289{
1290	switch (data->state) {
1291	case SA_INIT:
1292		return ikev2_build_sa_init(data);
1293	case SA_AUTH:
1294		return ikev2_build_sa_auth(data);
1295	case CHILD_SA:
1296		return NULL;
1297	case NOTIFY:
1298		return ikev2_build_notify(data);
1299	case IKEV2_DONE:
1300	case IKEV2_FAILED:
1301		return NULL;
1302	}
1303	return NULL;
1304}
1305