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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 software may be distributed under the terms of the BSD license.
      6  * See README for more details.
      7  */
      8 
      9 #include "includes.h"
     10 
     11 #include "common.h"
     12 #include "crypto/dh_groups.h"
     13 #include "crypto/random.h"
     14 #include "ikev2.h"
     15 
     16 
     17 void ikev2_responder_deinit(struct ikev2_responder_data *data)
     18 {
     19 	ikev2_free_keys(&data->keys);
     20 	wpabuf_free(data->i_dh_public);
     21 	wpabuf_free(data->r_dh_private);
     22 	os_free(data->IDi);
     23 	os_free(data->IDr);
     24 	os_free(data->shared_secret);
     25 	wpabuf_free(data->i_sign_msg);
     26 	wpabuf_free(data->r_sign_msg);
     27 	os_free(data->key_pad);
     28 }
     29 
     30 
     31 static int ikev2_derive_keys(struct ikev2_responder_data *data)
     32 {
     33 	u8 *buf, *pos, *pad, skeyseed[IKEV2_MAX_HASH_LEN];
     34 	size_t buf_len, pad_len;
     35 	struct wpabuf *shared;
     36 	const struct ikev2_integ_alg *integ;
     37 	const struct ikev2_prf_alg *prf;
     38 	const struct ikev2_encr_alg *encr;
     39 	int ret;
     40 	const u8 *addr[2];
     41 	size_t len[2];
     42 
     43 	/* RFC 4306, Sect. 2.14 */
     44 
     45 	integ = ikev2_get_integ(data->proposal.integ);
     46 	prf = ikev2_get_prf(data->proposal.prf);
     47 	encr = ikev2_get_encr(data->proposal.encr);
     48 	if (integ == NULL || prf == NULL || encr == NULL) {
     49 		wpa_printf(MSG_INFO, "IKEV2: Unsupported proposal");
     50 		return -1;
     51 	}
     52 
     53 	shared = dh_derive_shared(data->i_dh_public, data->r_dh_private,
     54 				  data->dh);
     55 	if (shared == NULL)
     56 		return -1;
     57 
     58 	/* Construct Ni | Nr | SPIi | SPIr */
     59 
     60 	buf_len = data->i_nonce_len + data->r_nonce_len + 2 * IKEV2_SPI_LEN;
     61 	buf = os_malloc(buf_len);
     62 	if (buf == NULL) {
     63 		wpabuf_free(shared);
     64 		return -1;
     65 	}
     66 
     67 	pos = buf;
     68 	os_memcpy(pos, data->i_nonce, data->i_nonce_len);
     69 	pos += data->i_nonce_len;
     70 	os_memcpy(pos, data->r_nonce, data->r_nonce_len);
     71 	pos += data->r_nonce_len;
     72 	os_memcpy(pos, data->i_spi, IKEV2_SPI_LEN);
     73 	pos += IKEV2_SPI_LEN;
     74 	os_memcpy(pos, data->r_spi, IKEV2_SPI_LEN);
     75 #ifdef CCNS_PL
     76 #if __BYTE_ORDER == __LITTLE_ENDIAN
     77 	{
     78 		int i;
     79 		u8 *tmp = pos - IKEV2_SPI_LEN;
     80 		/* Incorrect byte re-ordering on little endian hosts.. */
     81 		for (i = 0; i < IKEV2_SPI_LEN; i++)
     82 			*tmp++ = data->i_spi[IKEV2_SPI_LEN - 1 - i];
     83 		for (i = 0; i < IKEV2_SPI_LEN; i++)
     84 			*tmp++ = data->r_spi[IKEV2_SPI_LEN - 1 - i];
     85 	}
     86 #endif
     87 #endif /* CCNS_PL */
     88 
     89 	/* SKEYSEED = prf(Ni | Nr, g^ir) */
     90 	/* Use zero-padding per RFC 4306, Sect. 2.14 */
     91 	pad_len = data->dh->prime_len - wpabuf_len(shared);
     92 #ifdef CCNS_PL
     93 	/* Shared secret is not zero-padded correctly */
     94 	pad_len = 0;
     95 #endif /* CCNS_PL */
     96 	pad = os_zalloc(pad_len ? pad_len : 1);
     97 	if (pad == NULL) {
     98 		wpabuf_free(shared);
     99 		os_free(buf);
    100 		return -1;
    101 	}
    102 
    103 	addr[0] = pad;
    104 	len[0] = pad_len;
    105 	addr[1] = wpabuf_head(shared);
    106 	len[1] = wpabuf_len(shared);
    107 	if (ikev2_prf_hash(prf->id, buf, data->i_nonce_len + data->r_nonce_len,
    108 			   2, addr, len, skeyseed) < 0) {
    109 		wpabuf_free(shared);
    110 		os_free(buf);
    111 		os_free(pad);
    112 		return -1;
    113 	}
    114 	os_free(pad);
    115 	wpabuf_free(shared);
    116 
    117 	/* DH parameters are not needed anymore, so free them */
    118 	wpabuf_free(data->i_dh_public);
    119 	data->i_dh_public = NULL;
    120 	wpabuf_free(data->r_dh_private);
    121 	data->r_dh_private = NULL;
    122 
    123 	wpa_hexdump_key(MSG_DEBUG, "IKEV2: SKEYSEED",
    124 			skeyseed, prf->hash_len);
    125 
    126 	ret = ikev2_derive_sk_keys(prf, integ, encr, skeyseed, buf, buf_len,
    127 				   &data->keys);
    128 	os_free(buf);
    129 	return ret;
    130 }
    131 
    132 
    133 static int ikev2_parse_transform(struct ikev2_proposal_data *prop,
    134 				 const u8 *pos, const u8 *end)
    135 {
    136 	int transform_len;
    137 	const struct ikev2_transform *t;
    138 	u16 transform_id;
    139 	const u8 *tend;
    140 
    141 	if (end - pos < (int) sizeof(*t)) {
    142 		wpa_printf(MSG_INFO, "IKEV2: Too short transform");
    143 		return -1;
    144 	}
    145 
    146 	t = (const struct ikev2_transform *) pos;
    147 	transform_len = WPA_GET_BE16(t->transform_length);
    148 	if (transform_len < (int) sizeof(*t) || pos + transform_len > end) {
    149 		wpa_printf(MSG_INFO, "IKEV2: Invalid transform length %d",
    150 			   transform_len);
    151 		return -1;
    152 	}
    153 	tend = pos + transform_len;
    154 
    155 	transform_id = WPA_GET_BE16(t->transform_id);
    156 
    157 	wpa_printf(MSG_DEBUG, "IKEV2:   Transform:");
    158 	wpa_printf(MSG_DEBUG, "IKEV2:     Type: %d  Transform Length: %d  "
    159 		   "Transform Type: %d  Transform ID: %d",
    160 		   t->type, transform_len, t->transform_type, transform_id);
    161 
    162 	if (t->type != 0 && t->type != 3) {
    163 		wpa_printf(MSG_INFO, "IKEV2: Unexpected Transform type");
    164 		return -1;
    165 	}
    166 
    167 	pos = (const u8 *) (t + 1);
    168 	if (pos < tend) {
    169 		wpa_hexdump(MSG_DEBUG, "IKEV2:     Transform Attributes",
    170 			    pos, tend - pos);
    171 	}
    172 
    173 	switch (t->transform_type) {
    174 	case IKEV2_TRANSFORM_ENCR:
    175 		if (ikev2_get_encr(transform_id)) {
    176 			if (transform_id == ENCR_AES_CBC) {
    177 				if (tend - pos != 4) {
    178 					wpa_printf(MSG_DEBUG, "IKEV2: No "
    179 						   "Transform Attr for AES");
    180 					break;
    181 				}
    182 #ifdef CCNS_PL
    183 				if (WPA_GET_BE16(pos) != 0x001d /* ?? */) {
    184 					wpa_printf(MSG_DEBUG, "IKEV2: Not a "
    185 						   "Key Size attribute for "
    186 						   "AES");
    187 					break;
    188 				}
    189 #else /* CCNS_PL */
    190 				if (WPA_GET_BE16(pos) != 0x800e) {
    191 					wpa_printf(MSG_DEBUG, "IKEV2: Not a "
    192 						   "Key Size attribute for "
    193 						   "AES");
    194 					break;
    195 				}
    196 #endif /* CCNS_PL */
    197 				if (WPA_GET_BE16(pos + 2) != 128) {
    198 					wpa_printf(MSG_DEBUG, "IKEV2: "
    199 						   "Unsupported AES key size "
    200 						   "%d bits",
    201 						   WPA_GET_BE16(pos + 2));
    202 					break;
    203 				}
    204 			}
    205 			prop->encr = transform_id;
    206 		}
    207 		break;
    208 	case IKEV2_TRANSFORM_PRF:
    209 		if (ikev2_get_prf(transform_id))
    210 			prop->prf = transform_id;
    211 		break;
    212 	case IKEV2_TRANSFORM_INTEG:
    213 		if (ikev2_get_integ(transform_id))
    214 			prop->integ = transform_id;
    215 		break;
    216 	case IKEV2_TRANSFORM_DH:
    217 		if (dh_groups_get(transform_id))
    218 			prop->dh = transform_id;
    219 		break;
    220 	}
    221 
    222 	return transform_len;
    223 }
    224 
    225 
    226 static int ikev2_parse_proposal(struct ikev2_proposal_data *prop,
    227 				const u8 *pos, const u8 *end)
    228 {
    229 	const u8 *pend, *ppos;
    230 	int proposal_len, i;
    231 	const struct ikev2_proposal *p;
    232 
    233 	if (end - pos < (int) sizeof(*p)) {
    234 		wpa_printf(MSG_INFO, "IKEV2: Too short proposal");
    235 		return -1;
    236 	}
    237 
    238 	/* FIX: AND processing if multiple proposals use the same # */
    239 
    240 	p = (const struct ikev2_proposal *) pos;
    241 	proposal_len = WPA_GET_BE16(p->proposal_length);
    242 	if (proposal_len < (int) sizeof(*p) || pos + proposal_len > end) {
    243 		wpa_printf(MSG_INFO, "IKEV2: Invalid proposal length %d",
    244 			   proposal_len);
    245 		return -1;
    246 	}
    247 	wpa_printf(MSG_DEBUG, "IKEV2: SAi1 Proposal # %d",
    248 		   p->proposal_num);
    249 	wpa_printf(MSG_DEBUG, "IKEV2:   Type: %d  Proposal Length: %d "
    250 		   " Protocol ID: %d",
    251 		   p->type, proposal_len, p->protocol_id);
    252 	wpa_printf(MSG_DEBUG, "IKEV2:   SPI Size: %d  Transforms: %d",
    253 		   p->spi_size, p->num_transforms);
    254 
    255 	if (p->type != 0 && p->type != 2) {
    256 		wpa_printf(MSG_INFO, "IKEV2: Unexpected Proposal type");
    257 		return -1;
    258 	}
    259 
    260 	if (p->protocol_id != IKEV2_PROTOCOL_IKE) {
    261 		wpa_printf(MSG_DEBUG, "IKEV2: Unexpected Protocol ID "
    262 			   "(only IKE allowed for EAP-IKEv2)");
    263 		return -1;
    264 	}
    265 
    266 	if (p->proposal_num != prop->proposal_num) {
    267 		if (p->proposal_num == prop->proposal_num + 1)
    268 			prop->proposal_num = p->proposal_num;
    269 		else {
    270 			wpa_printf(MSG_INFO, "IKEV2: Unexpected Proposal #");
    271 			return -1;
    272 		}
    273 	}
    274 
    275 	ppos = (const u8 *) (p + 1);
    276 	pend = pos + proposal_len;
    277 	if (ppos + p->spi_size > pend) {
    278 		wpa_printf(MSG_INFO, "IKEV2: Not enough room for SPI "
    279 			   "in proposal");
    280 		return -1;
    281 	}
    282 	if (p->spi_size) {
    283 		wpa_hexdump(MSG_DEBUG, "IKEV2:    SPI",
    284 			    ppos, p->spi_size);
    285 		ppos += p->spi_size;
    286 	}
    287 
    288 	/*
    289 	 * For initial IKE_SA negotiation, SPI Size MUST be zero; for
    290 	 * subsequent negotiations, it must be 8 for IKE. We only support
    291 	 * initial case for now.
    292 	 */
    293 	if (p->spi_size != 0) {
    294 		wpa_printf(MSG_INFO, "IKEV2: Unexpected SPI Size");
    295 		return -1;
    296 	}
    297 
    298 	if (p->num_transforms == 0) {
    299 		wpa_printf(MSG_INFO, "IKEV2: At least one transform required");
    300 		return -1;
    301 	}
    302 
    303 	for (i = 0; i < (int) p->num_transforms; i++) {
    304 		int tlen = ikev2_parse_transform(prop, ppos, pend);
    305 		if (tlen < 0)
    306 			return -1;
    307 		ppos += tlen;
    308 	}
    309 
    310 	if (ppos != pend) {
    311 		wpa_printf(MSG_INFO, "IKEV2: Unexpected data after "
    312 			   "transforms");
    313 		return -1;
    314 	}
    315 
    316 	return proposal_len;
    317 }
    318 
    319 
    320 static int ikev2_process_sai1(struct ikev2_responder_data *data,
    321 			      const u8 *sai1, size_t sai1_len)
    322 {
    323 	struct ikev2_proposal_data prop;
    324 	const u8 *pos, *end;
    325 	int found = 0;
    326 
    327 	/* Security Association Payloads: <Proposals> */
    328 
    329 	if (sai1 == NULL) {
    330 		wpa_printf(MSG_INFO, "IKEV2: SAi1 not received");
    331 		return -1;
    332 	}
    333 
    334 	os_memset(&prop, 0, sizeof(prop));
    335 	prop.proposal_num = 1;
    336 
    337 	pos = sai1;
    338 	end = sai1 + sai1_len;
    339 
    340 	while (pos < end) {
    341 		int plen;
    342 
    343 		prop.integ = -1;
    344 		prop.prf = -1;
    345 		prop.encr = -1;
    346 		prop.dh = -1;
    347 		plen = ikev2_parse_proposal(&prop, pos, end);
    348 		if (plen < 0)
    349 			return -1;
    350 
    351 		if (!found && prop.integ != -1 && prop.prf != -1 &&
    352 		    prop.encr != -1 && prop.dh != -1) {
    353 			os_memcpy(&data->proposal, &prop, sizeof(prop));
    354 			data->dh = dh_groups_get(prop.dh);
    355 			found = 1;
    356 		}
    357 
    358 		pos += plen;
    359 	}
    360 
    361 	if (pos != end) {
    362 		wpa_printf(MSG_INFO, "IKEV2: Unexpected data after proposals");
    363 		return -1;
    364 	}
    365 
    366 	if (!found) {
    367 		wpa_printf(MSG_INFO, "IKEV2: No acceptable proposal found");
    368 		return -1;
    369 	}
    370 
    371 	wpa_printf(MSG_DEBUG, "IKEV2: Accepted proposal #%d: ENCR:%d PRF:%d "
    372 		   "INTEG:%d D-H:%d", data->proposal.proposal_num,
    373 		   data->proposal.encr, data->proposal.prf,
    374 		   data->proposal.integ, data->proposal.dh);
    375 
    376 	return 0;
    377 }
    378 
    379 
    380 static int ikev2_process_kei(struct ikev2_responder_data *data,
    381 			     const u8 *kei, size_t kei_len)
    382 {
    383 	u16 group;
    384 
    385 	/*
    386 	 * Key Exchange Payload:
    387 	 * DH Group # (16 bits)
    388 	 * RESERVED (16 bits)
    389 	 * Key Exchange Data (Diffie-Hellman public value)
    390 	 */
    391 
    392 	if (kei == NULL) {
    393 		wpa_printf(MSG_INFO, "IKEV2: KEi not received");
    394 		return -1;
    395 	}
    396 
    397 	if (kei_len < 4 + 96) {
    398 		wpa_printf(MSG_INFO, "IKEV2: Too show Key Exchange Payload");
    399 		return -1;
    400 	}
    401 
    402 	group = WPA_GET_BE16(kei);
    403 	wpa_printf(MSG_DEBUG, "IKEV2: KEi DH Group #%u", group);
    404 
    405 	if (group != data->proposal.dh) {
    406 		wpa_printf(MSG_DEBUG, "IKEV2: KEi DH Group #%u does not match "
    407 			   "with the selected proposal (%u)",
    408 			   group, data->proposal.dh);
    409 		/* Reject message with Notify payload of type
    410 		 * INVALID_KE_PAYLOAD (RFC 4306, Sect. 3.4) */
    411 		data->error_type = INVALID_KE_PAYLOAD;
    412 		data->state = NOTIFY;
    413 		return -1;
    414 	}
    415 
    416 	if (data->dh == NULL) {
    417 		wpa_printf(MSG_INFO, "IKEV2: Unsupported DH group");
    418 		return -1;
    419 	}
    420 
    421 	/* RFC 4306, Section 3.4:
    422 	 * The length of DH public value MUST be equal to the length of the
    423 	 * prime modulus.
    424 	 */
    425 	if (kei_len - 4 != data->dh->prime_len) {
    426 		wpa_printf(MSG_INFO, "IKEV2: Invalid DH public value length "
    427 			   "%ld (expected %ld)",
    428 			   (long) (kei_len - 4), (long) data->dh->prime_len);
    429 		return -1;
    430 	}
    431 
    432 	wpabuf_free(data->i_dh_public);
    433 	data->i_dh_public = wpabuf_alloc(kei_len - 4);
    434 	if (data->i_dh_public == NULL)
    435 		return -1;
    436 	wpabuf_put_data(data->i_dh_public, kei + 4, kei_len - 4);
    437 
    438 	wpa_hexdump_buf(MSG_DEBUG, "IKEV2: KEi Diffie-Hellman Public Value",
    439 			data->i_dh_public);
    440 
    441 	return 0;
    442 }
    443 
    444 
    445 static int ikev2_process_ni(struct ikev2_responder_data *data,
    446 			    const u8 *ni, size_t ni_len)
    447 {
    448 	if (ni == NULL) {
    449 		wpa_printf(MSG_INFO, "IKEV2: Ni not received");
    450 		return -1;
    451 	}
    452 
    453 	if (ni_len < IKEV2_NONCE_MIN_LEN || ni_len > IKEV2_NONCE_MAX_LEN) {
    454 		wpa_printf(MSG_INFO, "IKEV2: Invalid Ni length %ld",
    455 		           (long) ni_len);
    456 		return -1;
    457 	}
    458 
    459 #ifdef CCNS_PL
    460 	/* Zeros are removed incorrectly from the beginning of the nonces */
    461 	while (ni_len > 1 && *ni == 0) {
    462 		ni_len--;
    463 		ni++;
    464 	}
    465 #endif /* CCNS_PL */
    466 
    467 	data->i_nonce_len = ni_len;
    468 	os_memcpy(data->i_nonce, ni, ni_len);
    469 	wpa_hexdump(MSG_MSGDUMP, "IKEV2: Ni",
    470 		    data->i_nonce, data->i_nonce_len);
    471 
    472 	return 0;
    473 }
    474 
    475 
    476 static int ikev2_process_sa_init(struct ikev2_responder_data *data,
    477 				 const struct ikev2_hdr *hdr,
    478 				 struct ikev2_payloads *pl)
    479 {
    480 	if (ikev2_process_sai1(data, pl->sa, pl->sa_len) < 0 ||
    481 	    ikev2_process_kei(data, pl->ke, pl->ke_len) < 0 ||
    482 	    ikev2_process_ni(data, pl->nonce, pl->nonce_len) < 0)
    483 		return -1;
    484 
    485 	os_memcpy(data->i_spi, hdr->i_spi, IKEV2_SPI_LEN);
    486 
    487 	return 0;
    488 }
    489 
    490 
    491 static int ikev2_process_idi(struct ikev2_responder_data *data,
    492 			     const u8 *idi, size_t idi_len)
    493 {
    494 	u8 id_type;
    495 
    496 	if (idi == NULL) {
    497 		wpa_printf(MSG_INFO, "IKEV2: No IDi received");
    498 		return -1;
    499 	}
    500 
    501 	if (idi_len < 4) {
    502 		wpa_printf(MSG_INFO, "IKEV2: Too short IDi payload");
    503 		return -1;
    504 	}
    505 
    506 	id_type = idi[0];
    507 	idi += 4;
    508 	idi_len -= 4;
    509 
    510 	wpa_printf(MSG_DEBUG, "IKEV2: IDi ID Type %d", id_type);
    511 	wpa_hexdump_ascii(MSG_DEBUG, "IKEV2: IDi", idi, idi_len);
    512 	os_free(data->IDi);
    513 	data->IDi = os_malloc(idi_len);
    514 	if (data->IDi == NULL)
    515 		return -1;
    516 	os_memcpy(data->IDi, idi, idi_len);
    517 	data->IDi_len = idi_len;
    518 	data->IDi_type = id_type;
    519 
    520 	return 0;
    521 }
    522 
    523 
    524 static int ikev2_process_cert(struct ikev2_responder_data *data,
    525 			      const u8 *cert, size_t cert_len)
    526 {
    527 	u8 cert_encoding;
    528 
    529 	if (cert == NULL) {
    530 		if (data->peer_auth == PEER_AUTH_CERT) {
    531 			wpa_printf(MSG_INFO, "IKEV2: No Certificate received");
    532 			return -1;
    533 		}
    534 		return 0;
    535 	}
    536 
    537 	if (cert_len < 1) {
    538 		wpa_printf(MSG_INFO, "IKEV2: No Cert Encoding field");
    539 		return -1;
    540 	}
    541 
    542 	cert_encoding = cert[0];
    543 	cert++;
    544 	cert_len--;
    545 
    546 	wpa_printf(MSG_DEBUG, "IKEV2: Cert Encoding %d", cert_encoding);
    547 	wpa_hexdump(MSG_MSGDUMP, "IKEV2: Certificate Data", cert, cert_len);
    548 
    549 	/* TODO: validate certificate */
    550 
    551 	return 0;
    552 }
    553 
    554 
    555 static int ikev2_process_auth_cert(struct ikev2_responder_data *data,
    556 				   u8 method, const u8 *auth, size_t auth_len)
    557 {
    558 	if (method != AUTH_RSA_SIGN) {
    559 		wpa_printf(MSG_INFO, "IKEV2: Unsupported authentication "
    560 			   "method %d", method);
    561 		return -1;
    562 	}
    563 
    564 	/* TODO: validate AUTH */
    565 	return 0;
    566 }
    567 
    568 
    569 static int ikev2_process_auth_secret(struct ikev2_responder_data *data,
    570 				     u8 method, const u8 *auth,
    571 				     size_t auth_len)
    572 {
    573 	u8 auth_data[IKEV2_MAX_HASH_LEN];
    574 	const struct ikev2_prf_alg *prf;
    575 
    576 	if (method != AUTH_SHARED_KEY_MIC) {
    577 		wpa_printf(MSG_INFO, "IKEV2: Unsupported authentication "
    578 			   "method %d", method);
    579 		return -1;
    580 	}
    581 
    582 	/* msg | Nr | prf(SK_pi,IDi') */
    583 	if (ikev2_derive_auth_data(data->proposal.prf, data->i_sign_msg,
    584 				   data->IDi, data->IDi_len, data->IDi_type,
    585 				   &data->keys, 1, data->shared_secret,
    586 				   data->shared_secret_len,
    587 				   data->r_nonce, data->r_nonce_len,
    588 				   data->key_pad, data->key_pad_len,
    589 				   auth_data) < 0) {
    590 		wpa_printf(MSG_INFO, "IKEV2: Could not derive AUTH data");
    591 		return -1;
    592 	}
    593 
    594 	wpabuf_free(data->i_sign_msg);
    595 	data->i_sign_msg = NULL;
    596 
    597 	prf = ikev2_get_prf(data->proposal.prf);
    598 	if (prf == NULL)
    599 		return -1;
    600 
    601 	if (auth_len != prf->hash_len ||
    602 	    os_memcmp(auth, auth_data, auth_len) != 0) {
    603 		wpa_printf(MSG_INFO, "IKEV2: Invalid Authentication Data");
    604 		wpa_hexdump(MSG_DEBUG, "IKEV2: Received Authentication Data",
    605 			    auth, auth_len);
    606 		wpa_hexdump(MSG_DEBUG, "IKEV2: Expected Authentication Data",
    607 			    auth_data, prf->hash_len);
    608 		data->error_type = AUTHENTICATION_FAILED;
    609 		data->state = NOTIFY;
    610 		return -1;
    611 	}
    612 
    613 	wpa_printf(MSG_DEBUG, "IKEV2: Server authenticated successfully "
    614 		   "using shared keys");
    615 
    616 	return 0;
    617 }
    618 
    619 
    620 static int ikev2_process_auth(struct ikev2_responder_data *data,
    621 			      const u8 *auth, size_t auth_len)
    622 {
    623 	u8 auth_method;
    624 
    625 	if (auth == NULL) {
    626 		wpa_printf(MSG_INFO, "IKEV2: No Authentication Payload");
    627 		return -1;
    628 	}
    629 
    630 	if (auth_len < 4) {
    631 		wpa_printf(MSG_INFO, "IKEV2: Too short Authentication "
    632 			   "Payload");
    633 		return -1;
    634 	}
    635 
    636 	auth_method = auth[0];
    637 	auth += 4;
    638 	auth_len -= 4;
    639 
    640 	wpa_printf(MSG_DEBUG, "IKEV2: Auth Method %d", auth_method);
    641 	wpa_hexdump(MSG_MSGDUMP, "IKEV2: Authentication Data", auth, auth_len);
    642 
    643 	switch (data->peer_auth) {
    644 	case PEER_AUTH_CERT:
    645 		return ikev2_process_auth_cert(data, auth_method, auth,
    646 					       auth_len);
    647 	case PEER_AUTH_SECRET:
    648 		return ikev2_process_auth_secret(data, auth_method, auth,
    649 						 auth_len);
    650 	}
    651 
    652 	return -1;
    653 }
    654 
    655 
    656 static int ikev2_process_sa_auth_decrypted(struct ikev2_responder_data *data,
    657 					   u8 next_payload,
    658 					   u8 *payload, size_t payload_len)
    659 {
    660 	struct ikev2_payloads pl;
    661 
    662 	wpa_printf(MSG_DEBUG, "IKEV2: Processing decrypted payloads");
    663 
    664 	if (ikev2_parse_payloads(&pl, next_payload, payload, payload +
    665 				 payload_len) < 0) {
    666 		wpa_printf(MSG_INFO, "IKEV2: Failed to parse decrypted "
    667 			   "payloads");
    668 		return -1;
    669 	}
    670 
    671 	if (ikev2_process_idi(data, pl.idi, pl.idi_len) < 0 ||
    672 	    ikev2_process_cert(data, pl.cert, pl.cert_len) < 0 ||
    673 	    ikev2_process_auth(data, pl.auth, pl.auth_len) < 0)
    674 		return -1;
    675 
    676 	return 0;
    677 }
    678 
    679 
    680 static int ikev2_process_sa_auth(struct ikev2_responder_data *data,
    681 				 const struct ikev2_hdr *hdr,
    682 				 struct ikev2_payloads *pl)
    683 {
    684 	u8 *decrypted;
    685 	size_t decrypted_len;
    686 	int ret;
    687 
    688 	decrypted = ikev2_decrypt_payload(data->proposal.encr,
    689 					  data->proposal.integ,
    690 					  &data->keys, 1, hdr, pl->encrypted,
    691 					  pl->encrypted_len, &decrypted_len);
    692 	if (decrypted == NULL)
    693 		return -1;
    694 
    695 	ret = ikev2_process_sa_auth_decrypted(data, pl->encr_next_payload,
    696 					      decrypted, decrypted_len);
    697 	os_free(decrypted);
    698 
    699 	return ret;
    700 }
    701 
    702 
    703 static int ikev2_validate_rx_state(struct ikev2_responder_data *data,
    704 				   u8 exchange_type, u32 message_id)
    705 {
    706 	switch (data->state) {
    707 	case SA_INIT:
    708 		/* Expect to receive IKE_SA_INIT: HDR, SAi1, KEi, Ni */
    709 		if (exchange_type != IKE_SA_INIT) {
    710 			wpa_printf(MSG_INFO, "IKEV2: Unexpected Exchange Type "
    711 				   "%u in SA_INIT state", exchange_type);
    712 			return -1;
    713 		}
    714 		if (message_id != 0) {
    715 			wpa_printf(MSG_INFO, "IKEV2: Unexpected Message ID %u "
    716 				   "in SA_INIT state", message_id);
    717 			return -1;
    718 		}
    719 		break;
    720 	case SA_AUTH:
    721 		/* Expect to receive IKE_SA_AUTH:
    722 		 * HDR, SK {IDi, [CERT,] [CERTREQ,] [IDr,]
    723 		 *	AUTH, SAi2, TSi, TSr}
    724 		 */
    725 		if (exchange_type != IKE_SA_AUTH) {
    726 			wpa_printf(MSG_INFO, "IKEV2: Unexpected Exchange Type "
    727 				   "%u in SA_AUTH state", exchange_type);
    728 			return -1;
    729 		}
    730 		if (message_id != 1) {
    731 			wpa_printf(MSG_INFO, "IKEV2: Unexpected Message ID %u "
    732 				   "in SA_AUTH state", message_id);
    733 			return -1;
    734 		}
    735 		break;
    736 	case CHILD_SA:
    737 		if (exchange_type != CREATE_CHILD_SA) {
    738 			wpa_printf(MSG_INFO, "IKEV2: Unexpected Exchange Type "
    739 				   "%u in CHILD_SA state", exchange_type);
    740 			return -1;
    741 		}
    742 		if (message_id != 2) {
    743 			wpa_printf(MSG_INFO, "IKEV2: Unexpected Message ID %u "
    744 				   "in CHILD_SA state", message_id);
    745 			return -1;
    746 		}
    747 		break;
    748 	case NOTIFY:
    749 	case IKEV2_DONE:
    750 	case IKEV2_FAILED:
    751 		return -1;
    752 	}
    753 
    754 	return 0;
    755 }
    756 
    757 
    758 int ikev2_responder_process(struct ikev2_responder_data *data,
    759 			    const struct wpabuf *buf)
    760 {
    761 	const struct ikev2_hdr *hdr;
    762 	u32 length, message_id;
    763 	const u8 *pos, *end;
    764 	struct ikev2_payloads pl;
    765 
    766 	wpa_printf(MSG_MSGDUMP, "IKEV2: Received message (len %lu)",
    767 		   (unsigned long) wpabuf_len(buf));
    768 
    769 	if (wpabuf_len(buf) < sizeof(*hdr)) {
    770 		wpa_printf(MSG_INFO, "IKEV2: Too short frame to include HDR");
    771 		return -1;
    772 	}
    773 
    774 	data->error_type = 0;
    775 	hdr = (const struct ikev2_hdr *) wpabuf_head(buf);
    776 	end = wpabuf_head_u8(buf) + wpabuf_len(buf);
    777 	message_id = WPA_GET_BE32(hdr->message_id);
    778 	length = WPA_GET_BE32(hdr->length);
    779 
    780 	wpa_hexdump(MSG_DEBUG, "IKEV2:   IKE_SA Initiator's SPI",
    781 		    hdr->i_spi, IKEV2_SPI_LEN);
    782 	wpa_hexdump(MSG_DEBUG, "IKEV2:   IKE_SA Responder's SPI",
    783 		    hdr->r_spi, IKEV2_SPI_LEN);
    784 	wpa_printf(MSG_DEBUG, "IKEV2:   Next Payload: %u  Version: 0x%x  "
    785 		   "Exchange Type: %u",
    786 		   hdr->next_payload, hdr->version, hdr->exchange_type);
    787 	wpa_printf(MSG_DEBUG, "IKEV2:   Message ID: %u  Length: %u",
    788 		   message_id, length);
    789 
    790 	if (hdr->version != IKEV2_VERSION) {
    791 		wpa_printf(MSG_INFO, "IKEV2: Unsupported HDR version 0x%x "
    792 			   "(expected 0x%x)", hdr->version, IKEV2_VERSION);
    793 		return -1;
    794 	}
    795 
    796 	if (length != wpabuf_len(buf)) {
    797 		wpa_printf(MSG_INFO, "IKEV2: Invalid length (HDR: %lu != "
    798 			   "RX: %lu)", (unsigned long) length,
    799 			   (unsigned long) wpabuf_len(buf));
    800 		return -1;
    801 	}
    802 
    803 	if (ikev2_validate_rx_state(data, hdr->exchange_type, message_id) < 0)
    804 		return -1;
    805 
    806 	if ((hdr->flags & (IKEV2_HDR_INITIATOR | IKEV2_HDR_RESPONSE)) !=
    807 	    IKEV2_HDR_INITIATOR) {
    808 		wpa_printf(MSG_INFO, "IKEV2: Unexpected Flags value 0x%x",
    809 			   hdr->flags);
    810 		return -1;
    811 	}
    812 
    813 	if (data->state != SA_INIT) {
    814 		if (os_memcmp(data->i_spi, hdr->i_spi, IKEV2_SPI_LEN) != 0) {
    815 			wpa_printf(MSG_INFO, "IKEV2: Unexpected IKE_SA "
    816 				   "Initiator's SPI");
    817 			return -1;
    818 		}
    819 		if (os_memcmp(data->r_spi, hdr->r_spi, IKEV2_SPI_LEN) != 0) {
    820 			wpa_printf(MSG_INFO, "IKEV2: Unexpected IKE_SA "
    821 				   "Responder's SPI");
    822 			return -1;
    823 		}
    824 	}
    825 
    826 	pos = (const u8 *) (hdr + 1);
    827 	if (ikev2_parse_payloads(&pl, hdr->next_payload, pos, end) < 0)
    828 		return -1;
    829 
    830 	if (data->state == SA_INIT) {
    831 		data->last_msg = LAST_MSG_SA_INIT;
    832 		if (ikev2_process_sa_init(data, hdr, &pl) < 0) {
    833 			if (data->state == NOTIFY)
    834 				return 0;
    835 			return -1;
    836 		}
    837 		wpabuf_free(data->i_sign_msg);
    838 		data->i_sign_msg = wpabuf_dup(buf);
    839 	}
    840 
    841 	if (data->state == SA_AUTH) {
    842 		data->last_msg = LAST_MSG_SA_AUTH;
    843 		if (ikev2_process_sa_auth(data, hdr, &pl) < 0) {
    844 			if (data->state == NOTIFY)
    845 				return 0;
    846 			return -1;
    847 		}
    848 	}
    849 
    850 	return 0;
    851 }
    852 
    853 
    854 static void ikev2_build_hdr(struct ikev2_responder_data *data,
    855 			    struct wpabuf *msg, u8 exchange_type,
    856 			    u8 next_payload, u32 message_id)
    857 {
    858 	struct ikev2_hdr *hdr;
    859 
    860 	wpa_printf(MSG_DEBUG, "IKEV2: Adding HDR");
    861 
    862 	/* HDR - RFC 4306, Sect. 3.1 */
    863 	hdr = wpabuf_put(msg, sizeof(*hdr));
    864 	os_memcpy(hdr->i_spi, data->i_spi, IKEV2_SPI_LEN);
    865 	os_memcpy(hdr->r_spi, data->r_spi, IKEV2_SPI_LEN);
    866 	hdr->next_payload = next_payload;
    867 	hdr->version = IKEV2_VERSION;
    868 	hdr->exchange_type = exchange_type;
    869 	hdr->flags = IKEV2_HDR_RESPONSE;
    870 	WPA_PUT_BE32(hdr->message_id, message_id);
    871 }
    872 
    873 
    874 static int ikev2_build_sar1(struct ikev2_responder_data *data,
    875 			    struct wpabuf *msg, u8 next_payload)
    876 {
    877 	struct ikev2_payload_hdr *phdr;
    878 	size_t plen;
    879 	struct ikev2_proposal *p;
    880 	struct ikev2_transform *t;
    881 
    882 	wpa_printf(MSG_DEBUG, "IKEV2: Adding SAr1 payload");
    883 
    884 	/* SAr1 - RFC 4306, Sect. 2.7 and 3.3 */
    885 	phdr = wpabuf_put(msg, sizeof(*phdr));
    886 	phdr->next_payload = next_payload;
    887 	phdr->flags = 0;
    888 
    889 	p = wpabuf_put(msg, sizeof(*p));
    890 #ifdef CCNS_PL
    891 	/* Seems to require that the Proposal # is 1 even though RFC 4306
    892 	 * Sect 3.3.1 has following requirement "When a proposal is accepted,
    893 	 * all of the proposal numbers in the SA payload MUST be the same and
    894 	 * MUST match the number on the proposal sent that was accepted.".
    895 	 */
    896 	p->proposal_num = 1;
    897 #else /* CCNS_PL */
    898 	p->proposal_num = data->proposal.proposal_num;
    899 #endif /* CCNS_PL */
    900 	p->protocol_id = IKEV2_PROTOCOL_IKE;
    901 	p->num_transforms = 4;
    902 
    903 	t = wpabuf_put(msg, sizeof(*t));
    904 	t->type = 3;
    905 	t->transform_type = IKEV2_TRANSFORM_ENCR;
    906 	WPA_PUT_BE16(t->transform_id, data->proposal.encr);
    907 	if (data->proposal.encr == ENCR_AES_CBC) {
    908 		/* Transform Attribute: Key Len = 128 bits */
    909 #ifdef CCNS_PL
    910 		wpabuf_put_be16(msg, 0x001d); /* ?? */
    911 #else /* CCNS_PL */
    912 		wpabuf_put_be16(msg, 0x800e); /* AF=1, AttrType=14 */
    913 #endif /* CCNS_PL */
    914 		wpabuf_put_be16(msg, 128); /* 128-bit key */
    915 	}
    916 	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) t;
    917 	WPA_PUT_BE16(t->transform_length, plen);
    918 
    919 	t = wpabuf_put(msg, sizeof(*t));
    920 	t->type = 3;
    921 	WPA_PUT_BE16(t->transform_length, sizeof(*t));
    922 	t->transform_type = IKEV2_TRANSFORM_PRF;
    923 	WPA_PUT_BE16(t->transform_id, data->proposal.prf);
    924 
    925 	t = wpabuf_put(msg, sizeof(*t));
    926 	t->type = 3;
    927 	WPA_PUT_BE16(t->transform_length, sizeof(*t));
    928 	t->transform_type = IKEV2_TRANSFORM_INTEG;
    929 	WPA_PUT_BE16(t->transform_id, data->proposal.integ);
    930 
    931 	t = wpabuf_put(msg, sizeof(*t));
    932 	WPA_PUT_BE16(t->transform_length, sizeof(*t));
    933 	t->transform_type = IKEV2_TRANSFORM_DH;
    934 	WPA_PUT_BE16(t->transform_id, data->proposal.dh);
    935 
    936 	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) p;
    937 	WPA_PUT_BE16(p->proposal_length, plen);
    938 
    939 	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
    940 	WPA_PUT_BE16(phdr->payload_length, plen);
    941 
    942 	return 0;
    943 }
    944 
    945 
    946 static int ikev2_build_ker(struct ikev2_responder_data *data,
    947 			   struct wpabuf *msg, u8 next_payload)
    948 {
    949 	struct ikev2_payload_hdr *phdr;
    950 	size_t plen;
    951 	struct wpabuf *pv;
    952 
    953 	wpa_printf(MSG_DEBUG, "IKEV2: Adding KEr payload");
    954 
    955 	pv = dh_init(data->dh, &data->r_dh_private);
    956 	if (pv == NULL) {
    957 		wpa_printf(MSG_DEBUG, "IKEV2: Failed to initialize DH");
    958 		return -1;
    959 	}
    960 
    961 	/* KEr - RFC 4306, Sect. 3.4 */
    962 	phdr = wpabuf_put(msg, sizeof(*phdr));
    963 	phdr->next_payload = next_payload;
    964 	phdr->flags = 0;
    965 
    966 	wpabuf_put_be16(msg, data->proposal.dh); /* DH Group # */
    967 	wpabuf_put(msg, 2); /* RESERVED */
    968 	/*
    969 	 * RFC 4306, Sect. 3.4: possible zero padding for public value to
    970 	 * match the length of the prime.
    971 	 */
    972 	wpabuf_put(msg, data->dh->prime_len - wpabuf_len(pv));
    973 	wpabuf_put_buf(msg, pv);
    974 	wpabuf_free(pv);
    975 
    976 	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
    977 	WPA_PUT_BE16(phdr->payload_length, plen);
    978 	return 0;
    979 }
    980 
    981 
    982 static int ikev2_build_nr(struct ikev2_responder_data *data,
    983 			  struct wpabuf *msg, u8 next_payload)
    984 {
    985 	struct ikev2_payload_hdr *phdr;
    986 	size_t plen;
    987 
    988 	wpa_printf(MSG_DEBUG, "IKEV2: Adding Nr payload");
    989 
    990 	/* Nr - RFC 4306, Sect. 3.9 */
    991 	phdr = wpabuf_put(msg, sizeof(*phdr));
    992 	phdr->next_payload = next_payload;
    993 	phdr->flags = 0;
    994 	wpabuf_put_data(msg, data->r_nonce, data->r_nonce_len);
    995 	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
    996 	WPA_PUT_BE16(phdr->payload_length, plen);
    997 	return 0;
    998 }
    999 
   1000 
   1001 static int ikev2_build_idr(struct ikev2_responder_data *data,
   1002 			   struct wpabuf *msg, u8 next_payload)
   1003 {
   1004 	struct ikev2_payload_hdr *phdr;
   1005 	size_t plen;
   1006 
   1007 	wpa_printf(MSG_DEBUG, "IKEV2: Adding IDr payload");
   1008 
   1009 	if (data->IDr == NULL) {
   1010 		wpa_printf(MSG_INFO, "IKEV2: No IDr available");
   1011 		return -1;
   1012 	}
   1013 
   1014 	/* IDr - RFC 4306, Sect. 3.5 */
   1015 	phdr = wpabuf_put(msg, sizeof(*phdr));
   1016 	phdr->next_payload = next_payload;
   1017 	phdr->flags = 0;
   1018 	wpabuf_put_u8(msg, ID_KEY_ID);
   1019 	wpabuf_put(msg, 3); /* RESERVED */
   1020 	wpabuf_put_data(msg, data->IDr, data->IDr_len);
   1021 	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
   1022 	WPA_PUT_BE16(phdr->payload_length, plen);
   1023 	return 0;
   1024 }
   1025 
   1026 
   1027 static int ikev2_build_auth(struct ikev2_responder_data *data,
   1028 			    struct wpabuf *msg, u8 next_payload)
   1029 {
   1030 	struct ikev2_payload_hdr *phdr;
   1031 	size_t plen;
   1032 	const struct ikev2_prf_alg *prf;
   1033 
   1034 	wpa_printf(MSG_DEBUG, "IKEV2: Adding AUTH payload");
   1035 
   1036 	prf = ikev2_get_prf(data->proposal.prf);
   1037 	if (prf == NULL)
   1038 		return -1;
   1039 
   1040 	/* Authentication - RFC 4306, Sect. 3.8 */
   1041 	phdr = wpabuf_put(msg, sizeof(*phdr));
   1042 	phdr->next_payload = next_payload;
   1043 	phdr->flags = 0;
   1044 	wpabuf_put_u8(msg, AUTH_SHARED_KEY_MIC);
   1045 	wpabuf_put(msg, 3); /* RESERVED */
   1046 
   1047 	/* msg | Ni | prf(SK_pr,IDr') */
   1048 	if (ikev2_derive_auth_data(data->proposal.prf, data->r_sign_msg,
   1049 				   data->IDr, data->IDr_len, ID_KEY_ID,
   1050 				   &data->keys, 0, data->shared_secret,
   1051 				   data->shared_secret_len,
   1052 				   data->i_nonce, data->i_nonce_len,
   1053 				   data->key_pad, data->key_pad_len,
   1054 				   wpabuf_put(msg, prf->hash_len)) < 0) {
   1055 		wpa_printf(MSG_INFO, "IKEV2: Could not derive AUTH data");
   1056 		return -1;
   1057 	}
   1058 	wpabuf_free(data->r_sign_msg);
   1059 	data->r_sign_msg = NULL;
   1060 
   1061 	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
   1062 	WPA_PUT_BE16(phdr->payload_length, plen);
   1063 	return 0;
   1064 }
   1065 
   1066 
   1067 static int ikev2_build_notification(struct ikev2_responder_data *data,
   1068 				    struct wpabuf *msg, u8 next_payload)
   1069 {
   1070 	struct ikev2_payload_hdr *phdr;
   1071 	size_t plen;
   1072 
   1073 	wpa_printf(MSG_DEBUG, "IKEV2: Adding Notification payload");
   1074 
   1075 	if (data->error_type == 0) {
   1076 		wpa_printf(MSG_INFO, "IKEV2: No Notify Message Type "
   1077 			   "available");
   1078 		return -1;
   1079 	}
   1080 
   1081 	/* Notify - RFC 4306, Sect. 3.10 */
   1082 	phdr = wpabuf_put(msg, sizeof(*phdr));
   1083 	phdr->next_payload = next_payload;
   1084 	phdr->flags = 0;
   1085 #ifdef CCNS_PL
   1086 	wpabuf_put_u8(msg, 1); /* Protocol ID: IKE_SA notification */
   1087 #else /* CCNS_PL */
   1088 	wpabuf_put_u8(msg, 0); /* Protocol ID: no existing SA */
   1089 #endif /* CCNS_PL */
   1090 	wpabuf_put_u8(msg, 0); /* SPI Size */
   1091 	wpabuf_put_be16(msg, data->error_type);
   1092 
   1093 	switch (data->error_type) {
   1094 	case INVALID_KE_PAYLOAD:
   1095 		if (data->proposal.dh == -1) {
   1096 			wpa_printf(MSG_INFO, "IKEV2: No DH Group selected for "
   1097 				   "INVALID_KE_PAYLOAD notifications");
   1098 			return -1;
   1099 		}
   1100 		wpabuf_put_be16(msg, data->proposal.dh);
   1101 		wpa_printf(MSG_DEBUG, "IKEV2: INVALID_KE_PAYLOAD - request "
   1102 			   "DH Group #%d", data->proposal.dh);
   1103 		break;
   1104 	case AUTHENTICATION_FAILED:
   1105 		/* no associated data */
   1106 		break;
   1107 	default:
   1108 		wpa_printf(MSG_INFO, "IKEV2: Unsupported Notify Message Type "
   1109 			   "%d", data->error_type);
   1110 		return -1;
   1111 	}
   1112 
   1113 	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
   1114 	WPA_PUT_BE16(phdr->payload_length, plen);
   1115 	return 0;
   1116 }
   1117 
   1118 
   1119 static struct wpabuf * ikev2_build_sa_init(struct ikev2_responder_data *data)
   1120 {
   1121 	struct wpabuf *msg;
   1122 
   1123 	/* build IKE_SA_INIT: HDR, SAr1, KEr, Nr, [CERTREQ], [SK{IDr}] */
   1124 
   1125 	if (os_get_random(data->r_spi, IKEV2_SPI_LEN))
   1126 		return NULL;
   1127 	wpa_hexdump(MSG_DEBUG, "IKEV2: IKE_SA Responder's SPI",
   1128 		    data->r_spi, IKEV2_SPI_LEN);
   1129 
   1130 	data->r_nonce_len = IKEV2_NONCE_MIN_LEN;
   1131 	if (random_get_bytes(data->r_nonce, data->r_nonce_len))
   1132 		return NULL;
   1133 #ifdef CCNS_PL
   1134 	/* Zeros are removed incorrectly from the beginning of the nonces in
   1135 	 * key derivation; as a workaround, make sure Nr does not start with
   1136 	 * zero.. */
   1137 	if (data->r_nonce[0] == 0)
   1138 		data->r_nonce[0] = 1;
   1139 #endif /* CCNS_PL */
   1140 	wpa_hexdump(MSG_DEBUG, "IKEV2: Nr", data->r_nonce, data->r_nonce_len);
   1141 
   1142 	msg = wpabuf_alloc(sizeof(struct ikev2_hdr) + data->IDr_len + 1500);
   1143 	if (msg == NULL)
   1144 		return NULL;
   1145 
   1146 	ikev2_build_hdr(data, msg, IKE_SA_INIT, IKEV2_PAYLOAD_SA, 0);
   1147 	if (ikev2_build_sar1(data, msg, IKEV2_PAYLOAD_KEY_EXCHANGE) ||
   1148 	    ikev2_build_ker(data, msg, IKEV2_PAYLOAD_NONCE) ||
   1149 	    ikev2_build_nr(data, msg, data->peer_auth == PEER_AUTH_SECRET ?
   1150 			   IKEV2_PAYLOAD_ENCRYPTED :
   1151 			   IKEV2_PAYLOAD_NO_NEXT_PAYLOAD)) {
   1152 		wpabuf_free(msg);
   1153 		return NULL;
   1154 	}
   1155 
   1156 	if (ikev2_derive_keys(data)) {
   1157 		wpabuf_free(msg);
   1158 		return NULL;
   1159 	}
   1160 
   1161 	if (data->peer_auth == PEER_AUTH_CERT) {
   1162 		/* TODO: CERTREQ with SHA-1 hashes of Subject Public Key Info
   1163 		 * for trust agents */
   1164 	}
   1165 
   1166 	if (data->peer_auth == PEER_AUTH_SECRET) {
   1167 		struct wpabuf *plain = wpabuf_alloc(data->IDr_len + 1000);
   1168 		if (plain == NULL) {
   1169 			wpabuf_free(msg);
   1170 			return NULL;
   1171 		}
   1172 		if (ikev2_build_idr(data, plain,
   1173 				    IKEV2_PAYLOAD_NO_NEXT_PAYLOAD) ||
   1174 		    ikev2_build_encrypted(data->proposal.encr,
   1175 					  data->proposal.integ,
   1176 					  &data->keys, 0, msg, plain,
   1177 					  IKEV2_PAYLOAD_IDr)) {
   1178 			wpabuf_free(plain);
   1179 			wpabuf_free(msg);
   1180 			return NULL;
   1181 		}
   1182 		wpabuf_free(plain);
   1183 	}
   1184 
   1185 	ikev2_update_hdr(msg);
   1186 
   1187 	wpa_hexdump_buf(MSG_MSGDUMP, "IKEV2: Sending message (SA_INIT)", msg);
   1188 
   1189 	data->state = SA_AUTH;
   1190 
   1191 	wpabuf_free(data->r_sign_msg);
   1192 	data->r_sign_msg = wpabuf_dup(msg);
   1193 
   1194 	return msg;
   1195 }
   1196 
   1197 
   1198 static struct wpabuf * ikev2_build_sa_auth(struct ikev2_responder_data *data)
   1199 {
   1200 	struct wpabuf *msg, *plain;
   1201 
   1202 	/* build IKE_SA_AUTH: HDR, SK {IDr, [CERT,] AUTH} */
   1203 
   1204 	msg = wpabuf_alloc(sizeof(struct ikev2_hdr) + data->IDr_len + 1000);
   1205 	if (msg == NULL)
   1206 		return NULL;
   1207 	ikev2_build_hdr(data, msg, IKE_SA_AUTH, IKEV2_PAYLOAD_ENCRYPTED, 1);
   1208 
   1209 	plain = wpabuf_alloc(data->IDr_len + 1000);
   1210 	if (plain == NULL) {
   1211 		wpabuf_free(msg);
   1212 		return NULL;
   1213 	}
   1214 
   1215 	if (ikev2_build_idr(data, plain, IKEV2_PAYLOAD_AUTHENTICATION) ||
   1216 	    ikev2_build_auth(data, plain, IKEV2_PAYLOAD_NO_NEXT_PAYLOAD) ||
   1217 	    ikev2_build_encrypted(data->proposal.encr, data->proposal.integ,
   1218 				  &data->keys, 0, msg, plain,
   1219 				  IKEV2_PAYLOAD_IDr)) {
   1220 		wpabuf_free(plain);
   1221 		wpabuf_free(msg);
   1222 		return NULL;
   1223 	}
   1224 	wpabuf_free(plain);
   1225 
   1226 	wpa_hexdump_buf(MSG_MSGDUMP, "IKEV2: Sending message (SA_AUTH)", msg);
   1227 
   1228 	data->state = IKEV2_DONE;
   1229 
   1230 	return msg;
   1231 }
   1232 
   1233 
   1234 static struct wpabuf * ikev2_build_notify(struct ikev2_responder_data *data)
   1235 {
   1236 	struct wpabuf *msg;
   1237 
   1238 	msg = wpabuf_alloc(sizeof(struct ikev2_hdr) + 1000);
   1239 	if (msg == NULL)
   1240 		return NULL;
   1241 	if (data->last_msg == LAST_MSG_SA_AUTH) {
   1242 		/* HDR, SK{N} */
   1243 		struct wpabuf *plain = wpabuf_alloc(100);
   1244 		if (plain == NULL) {
   1245 			wpabuf_free(msg);
   1246 			return NULL;
   1247 		}
   1248 		ikev2_build_hdr(data, msg, IKE_SA_AUTH,
   1249 				IKEV2_PAYLOAD_ENCRYPTED, 1);
   1250 		if (ikev2_build_notification(data, plain,
   1251 					     IKEV2_PAYLOAD_NO_NEXT_PAYLOAD) ||
   1252 		    ikev2_build_encrypted(data->proposal.encr,
   1253 					  data->proposal.integ,
   1254 					  &data->keys, 0, msg, plain,
   1255 					  IKEV2_PAYLOAD_NOTIFICATION)) {
   1256 			wpabuf_free(plain);
   1257 			wpabuf_free(msg);
   1258 			return NULL;
   1259 		}
   1260 		data->state = IKEV2_FAILED;
   1261 	} else {
   1262 		/* HDR, N */
   1263 		ikev2_build_hdr(data, msg, IKE_SA_INIT,
   1264 				IKEV2_PAYLOAD_NOTIFICATION, 0);
   1265 		if (ikev2_build_notification(data, msg,
   1266 					     IKEV2_PAYLOAD_NO_NEXT_PAYLOAD)) {
   1267 			wpabuf_free(msg);
   1268 			return NULL;
   1269 		}
   1270 		data->state = SA_INIT;
   1271 	}
   1272 
   1273 	ikev2_update_hdr(msg);
   1274 
   1275 	wpa_hexdump_buf(MSG_MSGDUMP, "IKEV2: Sending message (Notification)",
   1276 			msg);
   1277 
   1278 	return msg;
   1279 }
   1280 
   1281 
   1282 struct wpabuf * ikev2_responder_build(struct ikev2_responder_data *data)
   1283 {
   1284 	switch (data->state) {
   1285 	case SA_INIT:
   1286 		return ikev2_build_sa_init(data);
   1287 	case SA_AUTH:
   1288 		return ikev2_build_sa_auth(data);
   1289 	case CHILD_SA:
   1290 		return NULL;
   1291 	case NOTIFY:
   1292 		return ikev2_build_notify(data);
   1293 	case IKEV2_DONE:
   1294 	case IKEV2_FAILED:
   1295 		return NULL;
   1296 	}
   1297 	return NULL;
   1298 }
   1299