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      1 /*
      2  * IKEv2 responder (RFC 4306) for EAP-IKEV2
      3  * Copyright (c) 2007, Jouni Malinen <j (at) 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 
     22 void 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 
     36 static 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 
    138 static 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 
    231 static 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 
    325 static 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 
    385 static 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 
    450 static 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 
    481 static 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 
    496 static 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 
    529 static 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 
    560 static 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 
    574 static 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 
    625 static 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 
    661 static 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 
    685 static 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 
    708 static 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 
    763 int 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 
    859 static 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 
    879 static 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 
    951 static 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 
    987 static 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 
   1006 static 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 
   1032 static 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 
   1072 static 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 
   1124 static 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 
   1203 static 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 
   1239 static 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 
   1287 struct 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