ikev2.c revision 189261
1/* 2 * IKEv2 initiator (RFC 4306) for EAP-IKEV2 3 * Copyright (c) 2007, Jouni Malinen <j@w1.fi> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * Alternatively, this software may be distributed under the terms of BSD 10 * license. 11 * 12 * See README and COPYING for more details. 13 */ 14 15#include "includes.h" 16 17#include "common.h" 18#include "dh_groups.h" 19#include "ikev2.h" 20 21 22static int ikev2_process_idr(struct ikev2_initiator_data *data, 23 const u8 *idr, size_t idr_len); 24 25 26void ikev2_initiator_deinit(struct ikev2_initiator_data *data) 27{ 28 ikev2_free_keys(&data->keys); 29 wpabuf_free(data->r_dh_public); 30 wpabuf_free(data->i_dh_private); 31 os_free(data->IDi); 32 os_free(data->IDr); 33 os_free(data->shared_secret); 34 wpabuf_free(data->i_sign_msg); 35 wpabuf_free(data->r_sign_msg); 36 os_free(data->key_pad); 37} 38 39 40static int ikev2_derive_keys(struct ikev2_initiator_data *data) 41{ 42 u8 *buf, *pos, *pad, skeyseed[IKEV2_MAX_HASH_LEN]; 43 size_t buf_len, pad_len; 44 struct wpabuf *shared; 45 const struct ikev2_integ_alg *integ; 46 const struct ikev2_prf_alg *prf; 47 const struct ikev2_encr_alg *encr; 48 int ret; 49 const u8 *addr[2]; 50 size_t len[2]; 51 52 /* RFC 4306, Sect. 2.14 */ 53 54 integ = ikev2_get_integ(data->proposal.integ); 55 prf = ikev2_get_prf(data->proposal.prf); 56 encr = ikev2_get_encr(data->proposal.encr); 57 if (integ == NULL || prf == NULL || encr == NULL) { 58 wpa_printf(MSG_INFO, "IKEV2: Unsupported proposal"); 59 return -1; 60 } 61 62 shared = dh_derive_shared(data->r_dh_public, data->i_dh_private, 63 data->dh); 64 if (shared == NULL) 65 return -1; 66 67 /* Construct Ni | Nr | SPIi | SPIr */ 68 69 buf_len = data->i_nonce_len + data->r_nonce_len + 2 * IKEV2_SPI_LEN; 70 buf = os_malloc(buf_len); 71 if (buf == NULL) { 72 wpabuf_free(shared); 73 return -1; 74 } 75 76 pos = buf; 77 os_memcpy(pos, data->i_nonce, data->i_nonce_len); 78 pos += data->i_nonce_len; 79 os_memcpy(pos, data->r_nonce, data->r_nonce_len); 80 pos += data->r_nonce_len; 81 os_memcpy(pos, data->i_spi, IKEV2_SPI_LEN); 82 pos += IKEV2_SPI_LEN; 83 os_memcpy(pos, data->r_spi, IKEV2_SPI_LEN); 84 85 /* SKEYSEED = prf(Ni | Nr, g^ir) */ 86 87 /* Use zero-padding per RFC 4306, Sect. 2.14 */ 88 pad_len = data->dh->prime_len - wpabuf_len(shared); 89 pad = os_zalloc(pad_len ? pad_len : 1); 90 if (pad == NULL) { 91 wpabuf_free(shared); 92 os_free(buf); 93 return -1; 94 } 95 addr[0] = pad; 96 len[0] = pad_len; 97 addr[1] = wpabuf_head(shared); 98 len[1] = wpabuf_len(shared); 99 if (ikev2_prf_hash(prf->id, buf, data->i_nonce_len + data->r_nonce_len, 100 2, addr, len, skeyseed) < 0) { 101 wpabuf_free(shared); 102 os_free(buf); 103 os_free(pad); 104 return -1; 105 } 106 os_free(pad); 107 wpabuf_free(shared); 108 109 /* DH parameters are not needed anymore, so free them */ 110 wpabuf_free(data->r_dh_public); 111 data->r_dh_public = NULL; 112 wpabuf_free(data->i_dh_private); 113 data->i_dh_private = NULL; 114 115 wpa_hexdump_key(MSG_DEBUG, "IKEV2: SKEYSEED", 116 skeyseed, prf->hash_len); 117 118 ret = ikev2_derive_sk_keys(prf, integ, encr, skeyseed, buf, buf_len, 119 &data->keys); 120 os_free(buf); 121 return ret; 122} 123 124 125static int ikev2_parse_transform(struct ikev2_initiator_data *data, 126 struct ikev2_proposal_data *prop, 127 const u8 *pos, const u8 *end) 128{ 129 int transform_len; 130 const struct ikev2_transform *t; 131 u16 transform_id; 132 const u8 *tend; 133 134 if (end - pos < (int) sizeof(*t)) { 135 wpa_printf(MSG_INFO, "IKEV2: Too short transform"); 136 return -1; 137 } 138 139 t = (const struct ikev2_transform *) pos; 140 transform_len = WPA_GET_BE16(t->transform_length); 141 if (transform_len < (int) sizeof(*t) || pos + transform_len > end) { 142 wpa_printf(MSG_INFO, "IKEV2: Invalid transform length %d", 143 transform_len); 144 return -1; 145 } 146 tend = pos + transform_len; 147 148 transform_id = WPA_GET_BE16(t->transform_id); 149 150 wpa_printf(MSG_DEBUG, "IKEV2: Transform:"); 151 wpa_printf(MSG_DEBUG, "IKEV2: Type: %d Transform Length: %d " 152 "Transform Type: %d Transform ID: %d", 153 t->type, transform_len, t->transform_type, transform_id); 154 155 if (t->type != 0 && t->type != 3) { 156 wpa_printf(MSG_INFO, "IKEV2: Unexpected Transform type"); 157 return -1; 158 } 159 160 pos = (const u8 *) (t + 1); 161 if (pos < tend) { 162 wpa_hexdump(MSG_DEBUG, "IKEV2: Transform Attributes", 163 pos, tend - pos); 164 } 165 166 switch (t->transform_type) { 167 case IKEV2_TRANSFORM_ENCR: 168 if (ikev2_get_encr(transform_id) && 169 transform_id == data->proposal.encr) { 170 if (transform_id == ENCR_AES_CBC) { 171 if (tend - pos != 4) { 172 wpa_printf(MSG_DEBUG, "IKEV2: No " 173 "Transform Attr for AES"); 174 break; 175 } 176 if (WPA_GET_BE16(pos) != 0x800e) { 177 wpa_printf(MSG_DEBUG, "IKEV2: Not a " 178 "Key Size attribute for " 179 "AES"); 180 break; 181 } 182 if (WPA_GET_BE16(pos + 2) != 128) { 183 wpa_printf(MSG_DEBUG, "IKEV2: " 184 "Unsupported AES key size " 185 "%d bits", 186 WPA_GET_BE16(pos + 2)); 187 break; 188 } 189 } 190 prop->encr = transform_id; 191 } 192 break; 193 case IKEV2_TRANSFORM_PRF: 194 if (ikev2_get_prf(transform_id) && 195 transform_id == data->proposal.prf) 196 prop->prf = transform_id; 197 break; 198 case IKEV2_TRANSFORM_INTEG: 199 if (ikev2_get_integ(transform_id) && 200 transform_id == data->proposal.integ) 201 prop->integ = transform_id; 202 break; 203 case IKEV2_TRANSFORM_DH: 204 if (dh_groups_get(transform_id) && 205 transform_id == data->proposal.dh) 206 prop->dh = transform_id; 207 break; 208 } 209 210 return transform_len; 211} 212 213 214static int ikev2_parse_proposal(struct ikev2_initiator_data *data, 215 struct ikev2_proposal_data *prop, 216 const u8 *pos, const u8 *end) 217{ 218 const u8 *pend, *ppos; 219 int proposal_len, i; 220 const struct ikev2_proposal *p; 221 222 if (end - pos < (int) sizeof(*p)) { 223 wpa_printf(MSG_INFO, "IKEV2: Too short proposal"); 224 return -1; 225 } 226 227 p = (const struct ikev2_proposal *) pos; 228 proposal_len = WPA_GET_BE16(p->proposal_length); 229 if (proposal_len < (int) sizeof(*p) || pos + proposal_len > end) { 230 wpa_printf(MSG_INFO, "IKEV2: Invalid proposal length %d", 231 proposal_len); 232 return -1; 233 } 234 wpa_printf(MSG_DEBUG, "IKEV2: SAi1 Proposal # %d", 235 p->proposal_num); 236 wpa_printf(MSG_DEBUG, "IKEV2: Type: %d Proposal Length: %d " 237 " Protocol ID: %d", 238 p->type, proposal_len, p->protocol_id); 239 wpa_printf(MSG_DEBUG, "IKEV2: SPI Size: %d Transforms: %d", 240 p->spi_size, p->num_transforms); 241 242 if (p->type != 0 && p->type != 2) { 243 wpa_printf(MSG_INFO, "IKEV2: Unexpected Proposal type"); 244 return -1; 245 } 246 247 if (p->protocol_id != IKEV2_PROTOCOL_IKE) { 248 wpa_printf(MSG_DEBUG, "IKEV2: Unexpected Protocol ID " 249 "(only IKE allowed for EAP-IKEv2)"); 250 return -1; 251 } 252 253 if (p->proposal_num != prop->proposal_num) { 254 if (p->proposal_num == prop->proposal_num + 1) 255 prop->proposal_num = p->proposal_num; 256 else { 257 wpa_printf(MSG_INFO, "IKEV2: Unexpected Proposal #"); 258 return -1; 259 } 260 } 261 262 ppos = (const u8 *) (p + 1); 263 pend = pos + proposal_len; 264 if (ppos + p->spi_size > pend) { 265 wpa_printf(MSG_INFO, "IKEV2: Not enough room for SPI " 266 "in proposal"); 267 return -1; 268 } 269 if (p->spi_size) { 270 wpa_hexdump(MSG_DEBUG, "IKEV2: SPI", 271 ppos, p->spi_size); 272 ppos += p->spi_size; 273 } 274 275 /* 276 * For initial IKE_SA negotiation, SPI Size MUST be zero; for 277 * subsequent negotiations, it must be 8 for IKE. We only support 278 * initial case for now. 279 */ 280 if (p->spi_size != 0) { 281 wpa_printf(MSG_INFO, "IKEV2: Unexpected SPI Size"); 282 return -1; 283 } 284 285 if (p->num_transforms == 0) { 286 wpa_printf(MSG_INFO, "IKEV2: At least one transform required"); 287 return -1; 288 } 289 290 for (i = 0; i < (int) p->num_transforms; i++) { 291 int tlen = ikev2_parse_transform(data, prop, ppos, pend); 292 if (tlen < 0) 293 return -1; 294 ppos += tlen; 295 } 296 297 if (ppos != pend) { 298 wpa_printf(MSG_INFO, "IKEV2: Unexpected data after " 299 "transforms"); 300 return -1; 301 } 302 303 return proposal_len; 304} 305 306 307static int ikev2_process_sar1(struct ikev2_initiator_data *data, 308 const u8 *sar1, size_t sar1_len) 309{ 310 struct ikev2_proposal_data prop; 311 const u8 *pos, *end; 312 int found = 0; 313 314 /* Security Association Payloads: <Proposals> */ 315 316 if (sar1 == NULL) { 317 wpa_printf(MSG_INFO, "IKEV2: SAr1 not received"); 318 return -1; 319 } 320 321 os_memset(&prop, 0, sizeof(prop)); 322 prop.proposal_num = 1; 323 324 pos = sar1; 325 end = sar1 + sar1_len; 326 327 while (pos < end) { 328 int plen; 329 330 prop.integ = -1; 331 prop.prf = -1; 332 prop.encr = -1; 333 prop.dh = -1; 334 plen = ikev2_parse_proposal(data, &prop, pos, end); 335 if (plen < 0) 336 return -1; 337 338 if (!found && prop.integ != -1 && prop.prf != -1 && 339 prop.encr != -1 && prop.dh != -1) { 340 found = 1; 341 } 342 343 pos += plen; 344 345 /* Only one proposal expected in SAr */ 346 break; 347 } 348 349 if (pos != end) { 350 wpa_printf(MSG_INFO, "IKEV2: Unexpected data after proposal"); 351 return -1; 352 } 353 354 if (!found) { 355 wpa_printf(MSG_INFO, "IKEV2: No acceptable proposal found"); 356 return -1; 357 } 358 359 wpa_printf(MSG_DEBUG, "IKEV2: Accepted proposal #%d: ENCR:%d PRF:%d " 360 "INTEG:%d D-H:%d", data->proposal.proposal_num, 361 data->proposal.encr, data->proposal.prf, 362 data->proposal.integ, data->proposal.dh); 363 364 return 0; 365} 366 367 368static int ikev2_process_ker(struct ikev2_initiator_data *data, 369 const u8 *ker, size_t ker_len) 370{ 371 u16 group; 372 373 /* 374 * Key Exchange Payload: 375 * DH Group # (16 bits) 376 * RESERVED (16 bits) 377 * Key Exchange Data (Diffie-Hellman public value) 378 */ 379 380 if (ker == NULL) { 381 wpa_printf(MSG_INFO, "IKEV2: KEr not received"); 382 return -1; 383 } 384 385 if (ker_len < 4 + 96) { 386 wpa_printf(MSG_INFO, "IKEV2: Too show Key Exchange Payload"); 387 return -1; 388 } 389 390 group = WPA_GET_BE16(ker); 391 wpa_printf(MSG_DEBUG, "IKEV2: KEr DH Group #%u", group); 392 393 if (group != data->proposal.dh) { 394 wpa_printf(MSG_DEBUG, "IKEV2: KEr DH Group #%u does not match " 395 "with the selected proposal (%u)", 396 group, data->proposal.dh); 397 return -1; 398 } 399 400 if (data->dh == NULL) { 401 wpa_printf(MSG_INFO, "IKEV2: Unsupported DH group"); 402 return -1; 403 } 404 405 /* RFC 4306, Section 3.4: 406 * The length of DH public value MUST be equal to the lenght of the 407 * prime modulus. 408 */ 409 if (ker_len - 4 != data->dh->prime_len) { 410 wpa_printf(MSG_INFO, "IKEV2: Invalid DH public value length " 411 "%ld (expected %ld)", 412 (long) (ker_len - 4), (long) data->dh->prime_len); 413 return -1; 414 } 415 416 wpabuf_free(data->r_dh_public); 417 data->r_dh_public = wpabuf_alloc_copy(ker + 4, ker_len - 4); 418 if (data->r_dh_public == NULL) 419 return -1; 420 421 wpa_hexdump_buf(MSG_DEBUG, "IKEV2: KEr Diffie-Hellman Public Value", 422 data->r_dh_public); 423 424 return 0; 425} 426 427 428static int ikev2_process_nr(struct ikev2_initiator_data *data, 429 const u8 *nr, size_t nr_len) 430{ 431 if (nr == NULL) { 432 wpa_printf(MSG_INFO, "IKEV2: Nr not received"); 433 return -1; 434 } 435 436 if (nr_len < IKEV2_NONCE_MIN_LEN || nr_len > IKEV2_NONCE_MAX_LEN) { 437 wpa_printf(MSG_INFO, "IKEV2: Invalid Nr length %ld", 438 (long) nr_len); 439 return -1; 440 } 441 442 data->r_nonce_len = nr_len; 443 os_memcpy(data->r_nonce, nr, nr_len); 444 wpa_hexdump(MSG_MSGDUMP, "IKEV2: Nr", 445 data->r_nonce, data->r_nonce_len); 446 447 return 0; 448} 449 450 451static int ikev2_process_sa_init_encr(struct ikev2_initiator_data *data, 452 const struct ikev2_hdr *hdr, 453 const u8 *encrypted, 454 size_t encrypted_len, u8 next_payload) 455{ 456 u8 *decrypted; 457 size_t decrypted_len; 458 struct ikev2_payloads pl; 459 int ret = 0; 460 461 decrypted = ikev2_decrypt_payload(data->proposal.encr, 462 data->proposal.integ, &data->keys, 0, 463 hdr, encrypted, encrypted_len, 464 &decrypted_len); 465 if (decrypted == NULL) 466 return -1; 467 468 wpa_printf(MSG_DEBUG, "IKEV2: Processing decrypted payloads"); 469 470 if (ikev2_parse_payloads(&pl, next_payload, decrypted, 471 decrypted + decrypted_len) < 0) { 472 wpa_printf(MSG_INFO, "IKEV2: Failed to parse decrypted " 473 "payloads"); 474 return -1; 475 } 476 477 if (pl.idr) 478 ret = ikev2_process_idr(data, pl.idr, pl.idr_len); 479 480 os_free(decrypted); 481 482 return ret; 483} 484 485 486static int ikev2_process_sa_init(struct ikev2_initiator_data *data, 487 const struct ikev2_hdr *hdr, 488 struct ikev2_payloads *pl) 489{ 490 if (ikev2_process_sar1(data, pl->sa, pl->sa_len) < 0 || 491 ikev2_process_ker(data, pl->ke, pl->ke_len) < 0 || 492 ikev2_process_nr(data, pl->nonce, pl->nonce_len) < 0) 493 return -1; 494 495 os_memcpy(data->r_spi, hdr->r_spi, IKEV2_SPI_LEN); 496 497 if (ikev2_derive_keys(data) < 0) 498 return -1; 499 500 if (pl->encrypted) { 501 wpa_printf(MSG_DEBUG, "IKEV2: Encrypted payload in SA_INIT - " 502 "try to get IDr from it"); 503 if (ikev2_process_sa_init_encr(data, hdr, pl->encrypted, 504 pl->encrypted_len, 505 pl->encr_next_payload) < 0) { 506 wpa_printf(MSG_INFO, "IKEV2: Failed to process " 507 "encrypted payload"); 508 return -1; 509 } 510 } 511 512 data->state = SA_AUTH; 513 514 return 0; 515} 516 517 518static int ikev2_process_idr(struct ikev2_initiator_data *data, 519 const u8 *idr, size_t idr_len) 520{ 521 u8 id_type; 522 523 if (idr == NULL) { 524 wpa_printf(MSG_INFO, "IKEV2: No IDr received"); 525 return -1; 526 } 527 528 if (idr_len < 4) { 529 wpa_printf(MSG_INFO, "IKEV2: Too short IDr payload"); 530 return -1; 531 } 532 533 id_type = idr[0]; 534 idr += 4; 535 idr_len -= 4; 536 537 wpa_printf(MSG_DEBUG, "IKEV2: IDr ID Type %d", id_type); 538 wpa_hexdump_ascii(MSG_DEBUG, "IKEV2: IDr", idr, idr_len); 539 if (data->IDr) { 540 if (id_type != data->IDr_type || idr_len != data->IDr_len || 541 os_memcmp(idr, data->IDr, idr_len) != 0) { 542 wpa_printf(MSG_INFO, "IKEV2: IDr differs from the one " 543 "received earlier"); 544 wpa_printf(MSG_DEBUG, "IKEV2: Previous IDr ID Type %d", 545 id_type); 546 wpa_hexdump_ascii(MSG_DEBUG, "Previous IKEV2: IDr", 547 data->IDr, data->IDr_len); 548 return -1; 549 } 550 os_free(data->IDr); 551 } 552 data->IDr = os_malloc(idr_len); 553 if (data->IDr == NULL) 554 return -1; 555 os_memcpy(data->IDr, idr, idr_len); 556 data->IDr_len = idr_len; 557 data->IDr_type = id_type; 558 559 return 0; 560} 561 562 563static int ikev2_process_cert(struct ikev2_initiator_data *data, 564 const u8 *cert, size_t cert_len) 565{ 566 u8 cert_encoding; 567 568 if (cert == NULL) { 569 if (data->peer_auth == PEER_AUTH_CERT) { 570 wpa_printf(MSG_INFO, "IKEV2: No Certificate received"); 571 return -1; 572 } 573 return 0; 574 } 575 576 if (cert_len < 1) { 577 wpa_printf(MSG_INFO, "IKEV2: No Cert Encoding field"); 578 return -1; 579 } 580 581 cert_encoding = cert[0]; 582 cert++; 583 cert_len--; 584 585 wpa_printf(MSG_DEBUG, "IKEV2: Cert Encoding %d", cert_encoding); 586 wpa_hexdump(MSG_MSGDUMP, "IKEV2: Certificate Data", cert, cert_len); 587 588 /* TODO: validate certificate */ 589 590 return 0; 591} 592 593 594static int ikev2_process_auth_cert(struct ikev2_initiator_data *data, 595 u8 method, const u8 *auth, size_t auth_len) 596{ 597 if (method != AUTH_RSA_SIGN) { 598 wpa_printf(MSG_INFO, "IKEV2: Unsupported authentication " 599 "method %d", method); 600 return -1; 601 } 602 603 /* TODO: validate AUTH */ 604 return 0; 605} 606 607 608static int ikev2_process_auth_secret(struct ikev2_initiator_data *data, 609 u8 method, const u8 *auth, 610 size_t auth_len) 611{ 612 u8 auth_data[IKEV2_MAX_HASH_LEN]; 613 const struct ikev2_prf_alg *prf; 614 615 if (method != AUTH_SHARED_KEY_MIC) { 616 wpa_printf(MSG_INFO, "IKEV2: Unsupported authentication " 617 "method %d", method); 618 return -1; 619 } 620 621 /* msg | Ni | prf(SK_pr,IDr') */ 622 if (ikev2_derive_auth_data(data->proposal.prf, data->r_sign_msg, 623 data->IDr, data->IDr_len, data->IDr_type, 624 &data->keys, 0, data->shared_secret, 625 data->shared_secret_len, 626 data->i_nonce, data->i_nonce_len, 627 data->key_pad, data->key_pad_len, 628 auth_data) < 0) { 629 wpa_printf(MSG_INFO, "IKEV2: Could not derive AUTH data"); 630 return -1; 631 } 632 633 wpabuf_free(data->r_sign_msg); 634 data->r_sign_msg = NULL; 635 636 prf = ikev2_get_prf(data->proposal.prf); 637 if (prf == NULL) 638 return -1; 639 640 if (auth_len != prf->hash_len || 641 os_memcmp(auth, auth_data, auth_len) != 0) { 642 wpa_printf(MSG_INFO, "IKEV2: Invalid Authentication Data"); 643 wpa_hexdump(MSG_DEBUG, "IKEV2: Received Authentication Data", 644 auth, auth_len); 645 wpa_hexdump(MSG_DEBUG, "IKEV2: Expected Authentication Data", 646 auth_data, prf->hash_len); 647 return -1; 648 } 649 650 wpa_printf(MSG_DEBUG, "IKEV2: Peer authenticated successfully " 651 "using shared keys"); 652 653 return 0; 654} 655 656 657static int ikev2_process_auth(struct ikev2_initiator_data *data, 658 const u8 *auth, size_t auth_len) 659{ 660 u8 auth_method; 661 662 if (auth == NULL) { 663 wpa_printf(MSG_INFO, "IKEV2: No Authentication Payload"); 664 return -1; 665 } 666 667 if (auth_len < 4) { 668 wpa_printf(MSG_INFO, "IKEV2: Too short Authentication " 669 "Payload"); 670 return -1; 671 } 672 673 auth_method = auth[0]; 674 auth += 4; 675 auth_len -= 4; 676 677 wpa_printf(MSG_DEBUG, "IKEV2: Auth Method %d", auth_method); 678 wpa_hexdump(MSG_MSGDUMP, "IKEV2: Authentication Data", auth, auth_len); 679 680 switch (data->peer_auth) { 681 case PEER_AUTH_CERT: 682 return ikev2_process_auth_cert(data, auth_method, auth, 683 auth_len); 684 case PEER_AUTH_SECRET: 685 return ikev2_process_auth_secret(data, auth_method, auth, 686 auth_len); 687 } 688 689 return -1; 690} 691 692 693static int ikev2_process_sa_auth_decrypted(struct ikev2_initiator_data *data, 694 u8 next_payload, 695 u8 *payload, size_t payload_len) 696{ 697 struct ikev2_payloads pl; 698 699 wpa_printf(MSG_DEBUG, "IKEV2: Processing decrypted payloads"); 700 701 if (ikev2_parse_payloads(&pl, next_payload, payload, payload + 702 payload_len) < 0) { 703 wpa_printf(MSG_INFO, "IKEV2: Failed to parse decrypted " 704 "payloads"); 705 return -1; 706 } 707 708 if (ikev2_process_idr(data, pl.idr, pl.idr_len) < 0 || 709 ikev2_process_cert(data, pl.cert, pl.cert_len) < 0 || 710 ikev2_process_auth(data, pl.auth, pl.auth_len) < 0) 711 return -1; 712 713 return 0; 714} 715 716 717static int ikev2_process_sa_auth(struct ikev2_initiator_data *data, 718 const struct ikev2_hdr *hdr, 719 struct ikev2_payloads *pl) 720{ 721 u8 *decrypted; 722 size_t decrypted_len; 723 int ret; 724 725 decrypted = ikev2_decrypt_payload(data->proposal.encr, 726 data->proposal.integ, 727 &data->keys, 0, hdr, pl->encrypted, 728 pl->encrypted_len, &decrypted_len); 729 if (decrypted == NULL) 730 return -1; 731 732 ret = ikev2_process_sa_auth_decrypted(data, pl->encr_next_payload, 733 decrypted, decrypted_len); 734 os_free(decrypted); 735 736 if (ret == 0 && !data->unknown_user) { 737 wpa_printf(MSG_DEBUG, "IKEV2: Authentication completed"); 738 data->state = IKEV2_DONE; 739 } 740 741 return ret; 742} 743 744 745static int ikev2_validate_rx_state(struct ikev2_initiator_data *data, 746 u8 exchange_type, u32 message_id) 747{ 748 switch (data->state) { 749 case SA_INIT: 750 /* Expect to receive IKE_SA_INIT: HDR, SAr, KEr, Nr, [CERTREQ], 751 * [SK{IDr}] */ 752 if (exchange_type != IKE_SA_INIT) { 753 wpa_printf(MSG_INFO, "IKEV2: Unexpected Exchange Type " 754 "%u in SA_INIT state", exchange_type); 755 return -1; 756 } 757 if (message_id != 0) { 758 wpa_printf(MSG_INFO, "IKEV2: Unexpected Message ID %u " 759 "in SA_INIT state", message_id); 760 return -1; 761 } 762 break; 763 case SA_AUTH: 764 /* Expect to receive IKE_SA_AUTH: 765 * HDR, SK {IDr, [CERT,] [CERTREQ,] [NFID,] AUTH} 766 */ 767 if (exchange_type != IKE_SA_AUTH) { 768 wpa_printf(MSG_INFO, "IKEV2: Unexpected Exchange Type " 769 "%u in SA_AUTH state", exchange_type); 770 return -1; 771 } 772 if (message_id != 1) { 773 wpa_printf(MSG_INFO, "IKEV2: Unexpected Message ID %u " 774 "in SA_AUTH state", message_id); 775 return -1; 776 } 777 break; 778 case CHILD_SA: 779 if (exchange_type != CREATE_CHILD_SA) { 780 wpa_printf(MSG_INFO, "IKEV2: Unexpected Exchange Type " 781 "%u in CHILD_SA state", exchange_type); 782 return -1; 783 } 784 if (message_id != 2) { 785 wpa_printf(MSG_INFO, "IKEV2: Unexpected Message ID %u " 786 "in CHILD_SA state", message_id); 787 return -1; 788 } 789 break; 790 case IKEV2_DONE: 791 return -1; 792 } 793 794 return 0; 795} 796 797 798int ikev2_initiator_process(struct ikev2_initiator_data *data, 799 const struct wpabuf *buf) 800{ 801 const struct ikev2_hdr *hdr; 802 u32 length, message_id; 803 const u8 *pos, *end; 804 struct ikev2_payloads pl; 805 806 wpa_printf(MSG_MSGDUMP, "IKEV2: Received message (len %lu)", 807 (unsigned long) wpabuf_len(buf)); 808 809 if (wpabuf_len(buf) < sizeof(*hdr)) { 810 wpa_printf(MSG_INFO, "IKEV2: Too short frame to include HDR"); 811 return -1; 812 } 813 814 hdr = (const struct ikev2_hdr *) wpabuf_head(buf); 815 end = wpabuf_head_u8(buf) + wpabuf_len(buf); 816 message_id = WPA_GET_BE32(hdr->message_id); 817 length = WPA_GET_BE32(hdr->length); 818 819 wpa_hexdump(MSG_DEBUG, "IKEV2: IKE_SA Initiator's SPI", 820 hdr->i_spi, IKEV2_SPI_LEN); 821 wpa_hexdump(MSG_DEBUG, "IKEV2: IKE_SA Initiator's SPI", 822 hdr->r_spi, IKEV2_SPI_LEN); 823 wpa_printf(MSG_DEBUG, "IKEV2: Next Payload: %u Version: 0x%x " 824 "Exchange Type: %u", 825 hdr->next_payload, hdr->version, hdr->exchange_type); 826 wpa_printf(MSG_DEBUG, "IKEV2: Message ID: %u Length: %u", 827 message_id, length); 828 829 if (hdr->version != IKEV2_VERSION) { 830 wpa_printf(MSG_INFO, "IKEV2: Unsupported HDR version 0x%x " 831 "(expected 0x%x)", hdr->version, IKEV2_VERSION); 832 return -1; 833 } 834 835 if (length != wpabuf_len(buf)) { 836 wpa_printf(MSG_INFO, "IKEV2: Invalid length (HDR: %lu != " 837 "RX: %lu)", (unsigned long) length, 838 (unsigned long) wpabuf_len(buf)); 839 return -1; 840 } 841 842 if (ikev2_validate_rx_state(data, hdr->exchange_type, message_id) < 0) 843 return -1; 844 845 if ((hdr->flags & (IKEV2_HDR_INITIATOR | IKEV2_HDR_RESPONSE)) != 846 IKEV2_HDR_RESPONSE) { 847 wpa_printf(MSG_INFO, "IKEV2: Unexpected Flags value 0x%x", 848 hdr->flags); 849 return -1; 850 } 851 852 if (data->state != SA_INIT) { 853 if (os_memcmp(data->i_spi, hdr->i_spi, IKEV2_SPI_LEN) != 0) { 854 wpa_printf(MSG_INFO, "IKEV2: Unexpected IKE_SA " 855 "Initiator's SPI"); 856 return -1; 857 } 858 if (os_memcmp(data->r_spi, hdr->r_spi, IKEV2_SPI_LEN) != 0) { 859 wpa_printf(MSG_INFO, "IKEV2: Unexpected IKE_SA " 860 "Responder's SPI"); 861 return -1; 862 } 863 } 864 865 pos = (const u8 *) (hdr + 1); 866 if (ikev2_parse_payloads(&pl, hdr->next_payload, pos, end) < 0) 867 return -1; 868 869 switch (data->state) { 870 case SA_INIT: 871 if (ikev2_process_sa_init(data, hdr, &pl) < 0) 872 return -1; 873 wpabuf_free(data->r_sign_msg); 874 data->r_sign_msg = wpabuf_dup(buf); 875 break; 876 case SA_AUTH: 877 if (ikev2_process_sa_auth(data, hdr, &pl) < 0) 878 return -1; 879 break; 880 case CHILD_SA: 881 case IKEV2_DONE: 882 break; 883 } 884 885 return 0; 886} 887 888 889static void ikev2_build_hdr(struct ikev2_initiator_data *data, 890 struct wpabuf *msg, u8 exchange_type, 891 u8 next_payload, u32 message_id) 892{ 893 struct ikev2_hdr *hdr; 894 895 wpa_printf(MSG_DEBUG, "IKEV2: Adding HDR"); 896 897 /* HDR - RFC 4306, Sect. 3.1 */ 898 hdr = wpabuf_put(msg, sizeof(*hdr)); 899 os_memcpy(hdr->i_spi, data->i_spi, IKEV2_SPI_LEN); 900 os_memcpy(hdr->r_spi, data->r_spi, IKEV2_SPI_LEN); 901 hdr->next_payload = next_payload; 902 hdr->version = IKEV2_VERSION; 903 hdr->exchange_type = exchange_type; 904 hdr->flags = IKEV2_HDR_INITIATOR; 905 WPA_PUT_BE32(hdr->message_id, message_id); 906} 907 908 909static int ikev2_build_sai(struct ikev2_initiator_data *data, 910 struct wpabuf *msg, u8 next_payload) 911{ 912 struct ikev2_payload_hdr *phdr; 913 size_t plen; 914 struct ikev2_proposal *p; 915 struct ikev2_transform *t; 916 917 wpa_printf(MSG_DEBUG, "IKEV2: Adding SAi payload"); 918 919 /* SAi1 - RFC 4306, Sect. 2.7 and 3.3 */ 920 phdr = wpabuf_put(msg, sizeof(*phdr)); 921 phdr->next_payload = next_payload; 922 phdr->flags = 0; 923 924 /* TODO: support for multiple proposals */ 925 p = wpabuf_put(msg, sizeof(*p)); 926 p->proposal_num = data->proposal.proposal_num; 927 p->protocol_id = IKEV2_PROTOCOL_IKE; 928 p->num_transforms = 4; 929 930 t = wpabuf_put(msg, sizeof(*t)); 931 t->type = 3; 932 t->transform_type = IKEV2_TRANSFORM_ENCR; 933 WPA_PUT_BE16(t->transform_id, data->proposal.encr); 934 if (data->proposal.encr == ENCR_AES_CBC) { 935 /* Transform Attribute: Key Len = 128 bits */ 936 wpabuf_put_be16(msg, 0x800e); /* AF=1, AttrType=14 */ 937 wpabuf_put_be16(msg, 128); /* 128-bit key */ 938 } 939 plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) t; 940 WPA_PUT_BE16(t->transform_length, plen); 941 942 t = wpabuf_put(msg, sizeof(*t)); 943 t->type = 3; 944 WPA_PUT_BE16(t->transform_length, sizeof(*t)); 945 t->transform_type = IKEV2_TRANSFORM_PRF; 946 WPA_PUT_BE16(t->transform_id, data->proposal.prf); 947 948 t = wpabuf_put(msg, sizeof(*t)); 949 t->type = 3; 950 WPA_PUT_BE16(t->transform_length, sizeof(*t)); 951 t->transform_type = IKEV2_TRANSFORM_INTEG; 952 WPA_PUT_BE16(t->transform_id, data->proposal.integ); 953 954 t = wpabuf_put(msg, sizeof(*t)); 955 WPA_PUT_BE16(t->transform_length, sizeof(*t)); 956 t->transform_type = IKEV2_TRANSFORM_DH; 957 WPA_PUT_BE16(t->transform_id, data->proposal.dh); 958 959 plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) p; 960 WPA_PUT_BE16(p->proposal_length, plen); 961 962 plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr; 963 WPA_PUT_BE16(phdr->payload_length, plen); 964 965 return 0; 966} 967 968 969static int ikev2_build_kei(struct ikev2_initiator_data *data, 970 struct wpabuf *msg, u8 next_payload) 971{ 972 struct ikev2_payload_hdr *phdr; 973 size_t plen; 974 struct wpabuf *pv; 975 976 wpa_printf(MSG_DEBUG, "IKEV2: Adding KEi payload"); 977 978 data->dh = dh_groups_get(data->proposal.dh); 979 pv = dh_init(data->dh, &data->i_dh_private); 980 if (pv == NULL) { 981 wpa_printf(MSG_DEBUG, "IKEV2: Failed to initialize DH"); 982 return -1; 983 } 984 985 /* KEi - RFC 4306, Sect. 3.4 */ 986 phdr = wpabuf_put(msg, sizeof(*phdr)); 987 phdr->next_payload = next_payload; 988 phdr->flags = 0; 989 990 wpabuf_put_be16(msg, data->proposal.dh); /* DH Group # */ 991 wpabuf_put(msg, 2); /* RESERVED */ 992 /* 993 * RFC 4306, Sect. 3.4: possible zero padding for public value to 994 * match the length of the prime. 995 */ 996 wpabuf_put(msg, data->dh->prime_len - wpabuf_len(pv)); 997 wpabuf_put_buf(msg, pv); 998 os_free(pv); 999 1000 plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr; 1001 WPA_PUT_BE16(phdr->payload_length, plen); 1002 return 0; 1003} 1004 1005 1006static int ikev2_build_ni(struct ikev2_initiator_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 Ni payload"); 1013 1014 /* Ni - RFC 4306, Sect. 3.9 */ 1015 phdr = wpabuf_put(msg, sizeof(*phdr)); 1016 phdr->next_payload = next_payload; 1017 phdr->flags = 0; 1018 wpabuf_put_data(msg, data->i_nonce, data->i_nonce_len); 1019 plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr; 1020 WPA_PUT_BE16(phdr->payload_length, plen); 1021 return 0; 1022} 1023 1024 1025static int ikev2_build_idi(struct ikev2_initiator_data *data, 1026 struct wpabuf *msg, u8 next_payload) 1027{ 1028 struct ikev2_payload_hdr *phdr; 1029 size_t plen; 1030 1031 wpa_printf(MSG_DEBUG, "IKEV2: Adding IDi payload"); 1032 1033 if (data->IDi == NULL) { 1034 wpa_printf(MSG_INFO, "IKEV2: No IDi available"); 1035 return -1; 1036 } 1037 1038 /* IDi - RFC 4306, Sect. 3.5 */ 1039 phdr = wpabuf_put(msg, sizeof(*phdr)); 1040 phdr->next_payload = next_payload; 1041 phdr->flags = 0; 1042 wpabuf_put_u8(msg, ID_KEY_ID); 1043 wpabuf_put(msg, 3); /* RESERVED */ 1044 wpabuf_put_data(msg, data->IDi, data->IDi_len); 1045 plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr; 1046 WPA_PUT_BE16(phdr->payload_length, plen); 1047 return 0; 1048} 1049 1050 1051static int ikev2_build_auth(struct ikev2_initiator_data *data, 1052 struct wpabuf *msg, u8 next_payload) 1053{ 1054 struct ikev2_payload_hdr *phdr; 1055 size_t plen; 1056 const struct ikev2_prf_alg *prf; 1057 1058 wpa_printf(MSG_DEBUG, "IKEV2: Adding AUTH payload"); 1059 1060 prf = ikev2_get_prf(data->proposal.prf); 1061 if (prf == NULL) 1062 return -1; 1063 1064 /* Authentication - RFC 4306, Sect. 3.8 */ 1065 phdr = wpabuf_put(msg, sizeof(*phdr)); 1066 phdr->next_payload = next_payload; 1067 phdr->flags = 0; 1068 wpabuf_put_u8(msg, AUTH_SHARED_KEY_MIC); 1069 wpabuf_put(msg, 3); /* RESERVED */ 1070 1071 /* msg | Nr | prf(SK_pi,IDi') */ 1072 if (ikev2_derive_auth_data(data->proposal.prf, data->i_sign_msg, 1073 data->IDi, data->IDi_len, ID_KEY_ID, 1074 &data->keys, 1, data->shared_secret, 1075 data->shared_secret_len, 1076 data->r_nonce, data->r_nonce_len, 1077 data->key_pad, data->key_pad_len, 1078 wpabuf_put(msg, prf->hash_len)) < 0) { 1079 wpa_printf(MSG_INFO, "IKEV2: Could not derive AUTH data"); 1080 return -1; 1081 } 1082 wpabuf_free(data->i_sign_msg); 1083 data->i_sign_msg = NULL; 1084 1085 plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr; 1086 WPA_PUT_BE16(phdr->payload_length, plen); 1087 return 0; 1088} 1089 1090 1091static struct wpabuf * ikev2_build_sa_init(struct ikev2_initiator_data *data) 1092{ 1093 struct wpabuf *msg; 1094 1095 /* build IKE_SA_INIT: HDR, SAi, KEi, Ni */ 1096 1097 if (os_get_random(data->i_spi, IKEV2_SPI_LEN)) 1098 return NULL; 1099 wpa_hexdump(MSG_DEBUG, "IKEV2: IKE_SA Initiator's SPI", 1100 data->i_spi, IKEV2_SPI_LEN); 1101 1102 data->i_nonce_len = IKEV2_NONCE_MIN_LEN; 1103 if (os_get_random(data->i_nonce, data->i_nonce_len)) 1104 return NULL; 1105 wpa_hexdump(MSG_DEBUG, "IKEV2: Ni", data->i_nonce, data->i_nonce_len); 1106 1107 msg = wpabuf_alloc(sizeof(struct ikev2_hdr) + 1000); 1108 if (msg == NULL) 1109 return NULL; 1110 1111 ikev2_build_hdr(data, msg, IKE_SA_INIT, IKEV2_PAYLOAD_SA, 0); 1112 if (ikev2_build_sai(data, msg, IKEV2_PAYLOAD_KEY_EXCHANGE) || 1113 ikev2_build_kei(data, msg, IKEV2_PAYLOAD_NONCE) || 1114 ikev2_build_ni(data, msg, IKEV2_PAYLOAD_NO_NEXT_PAYLOAD)) { 1115 wpabuf_free(msg); 1116 return NULL; 1117 } 1118 1119 ikev2_update_hdr(msg); 1120 1121 wpa_hexdump_buf(MSG_MSGDUMP, "IKEV2: Sending message (SA_INIT)", msg); 1122 1123 wpabuf_free(data->i_sign_msg); 1124 data->i_sign_msg = wpabuf_dup(msg); 1125 1126 return msg; 1127} 1128 1129 1130static struct wpabuf * ikev2_build_sa_auth(struct ikev2_initiator_data *data) 1131{ 1132 struct wpabuf *msg, *plain; 1133 const u8 *secret; 1134 size_t secret_len; 1135 1136 secret = data->get_shared_secret(data->cb_ctx, data->IDr, 1137 data->IDr_len, &secret_len); 1138 if (secret == NULL) { 1139 wpa_printf(MSG_INFO, "IKEV2: Could not get shared secret - " 1140 "use fake value"); 1141 /* RFC 5106, Sect. 7: 1142 * Use a random key to fake AUTH generation in order to prevent 1143 * probing of user identities. 1144 */ 1145 data->unknown_user = 1; 1146 os_free(data->shared_secret); 1147 data->shared_secret = os_malloc(16); 1148 if (data->shared_secret == NULL) 1149 return NULL; 1150 data->shared_secret_len = 16; 1151 if (os_get_random(data->shared_secret, 16)) 1152 return NULL; 1153 } else { 1154 os_free(data->shared_secret); 1155 data->shared_secret = os_malloc(secret_len); 1156 if (data->shared_secret == NULL) 1157 return NULL; 1158 os_memcpy(data->shared_secret, secret, secret_len); 1159 data->shared_secret_len = secret_len; 1160 } 1161 1162 /* build IKE_SA_AUTH: HDR, SK {IDi, [CERT,] [CERTREQ,] AUTH} */ 1163 1164 msg = wpabuf_alloc(sizeof(struct ikev2_hdr) + data->IDr_len + 1000); 1165 if (msg == NULL) 1166 return NULL; 1167 ikev2_build_hdr(data, msg, IKE_SA_AUTH, IKEV2_PAYLOAD_ENCRYPTED, 1); 1168 1169 plain = wpabuf_alloc(data->IDr_len + 1000); 1170 if (plain == NULL) { 1171 wpabuf_free(msg); 1172 return NULL; 1173 } 1174 1175 if (ikev2_build_idi(data, plain, IKEV2_PAYLOAD_AUTHENTICATION) || 1176 ikev2_build_auth(data, plain, IKEV2_PAYLOAD_NO_NEXT_PAYLOAD) || 1177 ikev2_build_encrypted(data->proposal.encr, data->proposal.integ, 1178 &data->keys, 1, msg, plain, 1179 IKEV2_PAYLOAD_IDi)) { 1180 wpabuf_free(plain); 1181 wpabuf_free(msg); 1182 return NULL; 1183 } 1184 wpabuf_free(plain); 1185 1186 wpa_hexdump_buf(MSG_MSGDUMP, "IKEV2: Sending message (SA_AUTH)", msg); 1187 1188 return msg; 1189} 1190 1191 1192struct wpabuf * ikev2_initiator_build(struct ikev2_initiator_data *data) 1193{ 1194 switch (data->state) { 1195 case SA_INIT: 1196 return ikev2_build_sa_init(data); 1197 case SA_AUTH: 1198 return ikev2_build_sa_auth(data); 1199 case CHILD_SA: 1200 return NULL; 1201 case IKEV2_DONE: 1202 return NULL; 1203 } 1204 return NULL; 1205} 1206