2 * IKEv2 common routines for initiator and responder
3 * Copyright (c) 2007, Jouni Malinen <j@w1.fi>
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
12 #include "crypto/crypto.h"
13 #include "crypto/md5.h"
14 #include "crypto/sha1.h"
15 #include "crypto/random.h"
16 #include "ikev2_common.h"
19 static struct ikev2_integ_alg ikev2_integ_algs[] = {
20 { AUTH_HMAC_SHA1_96, 20, 12 },
21 { AUTH_HMAC_MD5_96, 16, 12 }
24 #define NUM_INTEG_ALGS ARRAY_SIZE(ikev2_integ_algs)
27 static struct ikev2_prf_alg ikev2_prf_algs[] = {
28 { PRF_HMAC_SHA1, 20, 20 },
29 { PRF_HMAC_MD5, 16, 16 }
32 #define NUM_PRF_ALGS ARRAY_SIZE(ikev2_prf_algs)
35 static struct ikev2_encr_alg ikev2_encr_algs[] = {
36 { ENCR_AES_CBC, 16, 16 }, /* only 128-bit keys supported for now */
40 #define NUM_ENCR_ALGS ARRAY_SIZE(ikev2_encr_algs)
43 const struct ikev2_integ_alg * ikev2_get_integ(int id)
47 for (i = 0; i < NUM_INTEG_ALGS; i++) {
48 if (ikev2_integ_algs[i].id == id)
49 return &ikev2_integ_algs[i];
56 int ikev2_integ_hash(int alg, const u8 *key, size_t key_len, const u8 *data,
57 size_t data_len, u8 *hash)
59 u8 tmphash[IKEV2_MAX_HASH_LEN];
62 case AUTH_HMAC_SHA1_96:
65 hmac_sha1(key, key_len, data, data_len, tmphash);
66 os_memcpy(hash, tmphash, 12);
68 case AUTH_HMAC_MD5_96:
71 hmac_md5(key, key_len, data, data_len, tmphash);
72 os_memcpy(hash, tmphash, 12);
82 const struct ikev2_prf_alg * ikev2_get_prf(int id)
86 for (i = 0; i < NUM_PRF_ALGS; i++) {
87 if (ikev2_prf_algs[i].id == id)
88 return &ikev2_prf_algs[i];
95 int ikev2_prf_hash(int alg, const u8 *key, size_t key_len,
96 size_t num_elem, const u8 *addr[], const size_t *len,
101 hmac_sha1_vector(key, key_len, num_elem, addr, len, hash);
104 hmac_md5_vector(key, key_len, num_elem, addr, len, hash);
114 int ikev2_prf_plus(int alg, const u8 *key, size_t key_len,
115 const u8 *data, size_t data_len,
116 u8 *out, size_t out_len)
118 u8 hash[IKEV2_MAX_HASH_LEN];
123 const struct ikev2_prf_alg *prf;
126 prf = ikev2_get_prf(alg);
129 hash_len = prf->hash_len;
144 res = ikev2_prf_hash(alg, key, key_len, 2, &addr[1],
147 res = ikev2_prf_hash(alg, key, key_len, 3, addr, len,
152 if ((int) clen > end - pos)
154 os_memcpy(pos, hash, clen);
163 const struct ikev2_encr_alg * ikev2_get_encr(int id)
167 for (i = 0; i < NUM_ENCR_ALGS; i++) {
168 if (ikev2_encr_algs[i].id == id)
169 return &ikev2_encr_algs[i];
176 int ikev2_encr_encrypt(int alg, const u8 *key, size_t key_len, const u8 *iv,
177 const u8 *plain, u8 *crypt, size_t len)
179 struct crypto_cipher *cipher;
184 encr_alg = CRYPTO_CIPHER_ALG_3DES;
187 encr_alg = CRYPTO_CIPHER_ALG_AES;
190 wpa_printf(MSG_DEBUG, "IKEV2: Unsupported encr alg %d", alg);
194 cipher = crypto_cipher_init(encr_alg, iv, key, key_len);
195 if (cipher == NULL) {
196 wpa_printf(MSG_INFO, "IKEV2: Failed to initialize cipher");
200 if (crypto_cipher_encrypt(cipher, plain, crypt, len) < 0) {
201 wpa_printf(MSG_INFO, "IKEV2: Encryption failed");
202 crypto_cipher_deinit(cipher);
205 crypto_cipher_deinit(cipher);
211 int ikev2_encr_decrypt(int alg, const u8 *key, size_t key_len, const u8 *iv,
212 const u8 *crypt, u8 *plain, size_t len)
214 struct crypto_cipher *cipher;
219 encr_alg = CRYPTO_CIPHER_ALG_3DES;
222 encr_alg = CRYPTO_CIPHER_ALG_AES;
225 wpa_printf(MSG_DEBUG, "IKEV2: Unsupported encr alg %d", alg);
229 cipher = crypto_cipher_init(encr_alg, iv, key, key_len);
230 if (cipher == NULL) {
231 wpa_printf(MSG_INFO, "IKEV2: Failed to initialize cipher");
235 if (crypto_cipher_decrypt(cipher, crypt, plain, len) < 0) {
236 wpa_printf(MSG_INFO, "IKEV2: Decryption failed");
237 crypto_cipher_deinit(cipher);
240 crypto_cipher_deinit(cipher);
246 int ikev2_parse_payloads(struct ikev2_payloads *payloads,
247 u8 next_payload, const u8 *pos, const u8 *end)
249 const struct ikev2_payload_hdr *phdr;
251 os_memset(payloads, 0, sizeof(*payloads));
253 while (next_payload != IKEV2_PAYLOAD_NO_NEXT_PAYLOAD) {
254 unsigned int plen, pdatalen, left;
256 wpa_printf(MSG_DEBUG, "IKEV2: Processing payload %u",
261 if (left < sizeof(*phdr)) {
262 wpa_printf(MSG_INFO, "IKEV2: Too short message for "
263 "payload header (left=%ld)",
267 phdr = (const struct ikev2_payload_hdr *) pos;
268 plen = WPA_GET_BE16(phdr->payload_length);
269 if (plen < sizeof(*phdr) || plen > left) {
270 wpa_printf(MSG_INFO, "IKEV2: Invalid payload header "
275 wpa_printf(MSG_DEBUG, "IKEV2: Next Payload: %u Flags: 0x%x"
276 " Payload Length: %u",
277 phdr->next_payload, phdr->flags, plen);
279 pdata = (const u8 *) (phdr + 1);
280 pdatalen = plen - sizeof(*phdr);
282 switch (next_payload) {
283 case IKEV2_PAYLOAD_SA:
284 wpa_printf(MSG_DEBUG, "IKEV2: Payload: Security "
286 payloads->sa = pdata;
287 payloads->sa_len = pdatalen;
289 case IKEV2_PAYLOAD_KEY_EXCHANGE:
290 wpa_printf(MSG_DEBUG, "IKEV2: Payload: Key "
292 payloads->ke = pdata;
293 payloads->ke_len = pdatalen;
295 case IKEV2_PAYLOAD_IDi:
296 wpa_printf(MSG_DEBUG, "IKEV2: Payload: IDi");
297 payloads->idi = pdata;
298 payloads->idi_len = pdatalen;
300 case IKEV2_PAYLOAD_IDr:
301 wpa_printf(MSG_DEBUG, "IKEV2: Payload: IDr");
302 payloads->idr = pdata;
303 payloads->idr_len = pdatalen;
305 case IKEV2_PAYLOAD_CERTIFICATE:
306 wpa_printf(MSG_DEBUG, "IKEV2: Payload: Certificate");
307 payloads->cert = pdata;
308 payloads->cert_len = pdatalen;
310 case IKEV2_PAYLOAD_AUTHENTICATION:
311 wpa_printf(MSG_DEBUG, "IKEV2: Payload: "
313 payloads->auth = pdata;
314 payloads->auth_len = pdatalen;
316 case IKEV2_PAYLOAD_NONCE:
317 wpa_printf(MSG_DEBUG, "IKEV2: Payload: Nonce");
318 payloads->nonce = pdata;
319 payloads->nonce_len = pdatalen;
321 case IKEV2_PAYLOAD_ENCRYPTED:
322 wpa_printf(MSG_DEBUG, "IKEV2: Payload: Encrypted");
323 payloads->encrypted = pdata;
324 payloads->encrypted_len = pdatalen;
326 case IKEV2_PAYLOAD_NOTIFICATION:
327 wpa_printf(MSG_DEBUG, "IKEV2: Payload: "
329 payloads->notification = pdata;
330 payloads->notification_len = pdatalen;
333 if (phdr->flags & IKEV2_PAYLOAD_FLAGS_CRITICAL) {
334 wpa_printf(MSG_INFO, "IKEV2: Unsupported "
335 "critical payload %u - reject the "
336 "entire message", next_payload);
339 wpa_printf(MSG_DEBUG, "IKEV2: Skipped "
340 "unsupported payload %u",
345 if (next_payload == IKEV2_PAYLOAD_ENCRYPTED &&
348 * Next Payload in the case of Encrypted Payload is
349 * actually the payload type for the first embedded
352 payloads->encr_next_payload = phdr->next_payload;
353 next_payload = IKEV2_PAYLOAD_NO_NEXT_PAYLOAD;
355 next_payload = phdr->next_payload;
361 wpa_printf(MSG_INFO, "IKEV2: Unexpected extra data after "
370 int ikev2_derive_auth_data(int prf_alg, const struct wpabuf *sign_msg,
371 const u8 *ID, size_t ID_len, u8 ID_type,
372 struct ikev2_keys *keys, int initiator,
373 const u8 *shared_secret, size_t shared_secret_len,
374 const u8 *nonce, size_t nonce_len,
375 const u8 *key_pad, size_t key_pad_len,
378 size_t sign_len, buf_len;
379 u8 *sign_data, *pos, *buf, hash[IKEV2_MAX_HASH_LEN];
380 const struct ikev2_prf_alg *prf;
381 const u8 *SK_p = initiator ? keys->SK_pi : keys->SK_pr;
383 prf = ikev2_get_prf(prf_alg);
384 if (sign_msg == NULL || ID == NULL || SK_p == NULL ||
385 shared_secret == NULL || nonce == NULL || prf == NULL)
388 /* prf(SK_pi/r,IDi/r') */
389 buf_len = 4 + ID_len;
390 buf = os_zalloc(buf_len);
394 os_memcpy(buf + 4, ID, ID_len);
395 if (ikev2_prf_hash(prf->id, SK_p, keys->SK_prf_len,
396 1, (const u8 **) &buf, &buf_len, hash) < 0) {
402 /* sign_data = msg | Nr/i | prf(SK_pi/r,IDi/r') */
403 sign_len = wpabuf_len(sign_msg) + nonce_len + prf->hash_len;
404 sign_data = os_malloc(sign_len);
405 if (sign_data == NULL)
408 os_memcpy(pos, wpabuf_head(sign_msg), wpabuf_len(sign_msg));
409 pos += wpabuf_len(sign_msg);
410 os_memcpy(pos, nonce, nonce_len);
412 os_memcpy(pos, hash, prf->hash_len);
414 /* AUTH = prf(prf(Shared Secret, key pad, sign_data) */
415 if (ikev2_prf_hash(prf->id, shared_secret, shared_secret_len, 1,
416 &key_pad, &key_pad_len, hash) < 0 ||
417 ikev2_prf_hash(prf->id, hash, prf->hash_len, 1,
418 (const u8 **) &sign_data, &sign_len, auth_data) < 0)
429 u8 * ikev2_decrypt_payload(int encr_id, int integ_id,
430 struct ikev2_keys *keys, int initiator,
431 const struct ikev2_hdr *hdr,
432 const u8 *encrypted, size_t encrypted_len,
436 const u8 *pos, *end, *iv, *integ;
437 u8 hash[IKEV2_MAX_HASH_LEN], *decrypted;
438 size_t decrypted_len, pad_len;
439 const struct ikev2_integ_alg *integ_alg;
440 const struct ikev2_encr_alg *encr_alg;
441 const u8 *SK_e = initiator ? keys->SK_ei : keys->SK_er;
442 const u8 *SK_a = initiator ? keys->SK_ai : keys->SK_ar;
444 if (encrypted == NULL) {
445 wpa_printf(MSG_INFO, "IKEV2: No Encrypted payload in SA_AUTH");
449 encr_alg = ikev2_get_encr(encr_id);
450 if (encr_alg == NULL) {
451 wpa_printf(MSG_INFO, "IKEV2: Unsupported encryption type");
454 iv_len = encr_alg->block_size;
456 integ_alg = ikev2_get_integ(integ_id);
457 if (integ_alg == NULL) {
458 wpa_printf(MSG_INFO, "IKEV2: Unsupported intergrity type");
462 if (encrypted_len < iv_len + 1 + integ_alg->hash_len) {
463 wpa_printf(MSG_INFO, "IKEV2: No room for IV or Integrity "
470 end = encrypted + encrypted_len;
471 integ = end - integ_alg->hash_len;
474 wpa_printf(MSG_INFO, "IKEV2: No SK_a available");
477 if (ikev2_integ_hash(integ_id, SK_a, keys->SK_integ_len,
479 integ - (const u8 *) hdr, hash) < 0) {
480 wpa_printf(MSG_INFO, "IKEV2: Failed to calculate integrity "
484 if (os_memcmp_const(integ, hash, integ_alg->hash_len) != 0) {
485 wpa_printf(MSG_INFO, "IKEV2: Incorrect Integrity Checksum "
491 wpa_printf(MSG_INFO, "IKEV2: No SK_e available");
495 decrypted_len = integ - pos;
496 decrypted = os_malloc(decrypted_len);
497 if (decrypted == NULL)
500 if (ikev2_encr_decrypt(encr_alg->id, SK_e, keys->SK_encr_len, iv, pos,
501 decrypted, decrypted_len) < 0) {
506 pad_len = decrypted[decrypted_len - 1];
507 if (decrypted_len < pad_len + 1) {
508 wpa_printf(MSG_INFO, "IKEV2: Invalid padding in encrypted "
514 decrypted_len -= pad_len + 1;
516 *res_len = decrypted_len;
521 void ikev2_update_hdr(struct wpabuf *msg)
523 struct ikev2_hdr *hdr;
525 /* Update lenth field in HDR */
526 hdr = wpabuf_mhead(msg);
527 WPA_PUT_BE32(hdr->length, wpabuf_len(msg));
531 int ikev2_build_encrypted(int encr_id, int integ_id, struct ikev2_keys *keys,
532 int initiator, struct wpabuf *msg,
533 struct wpabuf *plain, u8 next_payload)
535 struct ikev2_payload_hdr *phdr;
537 size_t iv_len, pad_len;
539 const struct ikev2_integ_alg *integ_alg;
540 const struct ikev2_encr_alg *encr_alg;
541 const u8 *SK_e = initiator ? keys->SK_ei : keys->SK_er;
542 const u8 *SK_a = initiator ? keys->SK_ai : keys->SK_ar;
544 wpa_printf(MSG_DEBUG, "IKEV2: Adding Encrypted payload");
546 /* Encr - RFC 4306, Sect. 3.14 */
548 encr_alg = ikev2_get_encr(encr_id);
549 if (encr_alg == NULL) {
550 wpa_printf(MSG_INFO, "IKEV2: Unsupported encryption type");
553 iv_len = encr_alg->block_size;
555 integ_alg = ikev2_get_integ(integ_id);
556 if (integ_alg == NULL) {
557 wpa_printf(MSG_INFO, "IKEV2: Unsupported intergrity type");
562 wpa_printf(MSG_INFO, "IKEV2: No SK_e available");
567 wpa_printf(MSG_INFO, "IKEV2: No SK_a available");
571 phdr = wpabuf_put(msg, sizeof(*phdr));
572 phdr->next_payload = next_payload;
575 iv = wpabuf_put(msg, iv_len);
576 if (random_get_bytes(iv, iv_len)) {
577 wpa_printf(MSG_INFO, "IKEV2: Could not generate IV");
581 pad_len = iv_len - (wpabuf_len(plain) + 1) % iv_len;
582 if (pad_len == iv_len)
584 wpabuf_put(plain, pad_len);
585 wpabuf_put_u8(plain, pad_len);
587 if (ikev2_encr_encrypt(encr_alg->id, SK_e, keys->SK_encr_len, iv,
588 wpabuf_head(plain), wpabuf_mhead(plain),
589 wpabuf_len(plain)) < 0)
592 wpabuf_put_buf(msg, plain);
594 /* Need to update all headers (Length fields) prior to hash func */
595 icv = wpabuf_put(msg, integ_alg->hash_len);
596 plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
597 WPA_PUT_BE16(phdr->payload_length, plen);
599 ikev2_update_hdr(msg);
601 return ikev2_integ_hash(integ_id, SK_a, keys->SK_integ_len,
603 wpabuf_len(msg) - integ_alg->hash_len, icv);
609 int ikev2_keys_set(struct ikev2_keys *keys)
611 return keys->SK_d && keys->SK_ai && keys->SK_ar && keys->SK_ei &&
612 keys->SK_er && keys->SK_pi && keys->SK_pr;
616 void ikev2_free_keys(struct ikev2_keys *keys)
619 os_free(keys->SK_ai);
620 os_free(keys->SK_ar);
621 os_free(keys->SK_ei);
622 os_free(keys->SK_er);
623 os_free(keys->SK_pi);
624 os_free(keys->SK_pr);
625 keys->SK_d = keys->SK_ai = keys->SK_ar = keys->SK_ei = keys->SK_er =
626 keys->SK_pi = keys->SK_pr = NULL;
630 int ikev2_derive_sk_keys(const struct ikev2_prf_alg *prf,
631 const struct ikev2_integ_alg *integ,
632 const struct ikev2_encr_alg *encr,
633 const u8 *skeyseed, const u8 *data, size_t data_len,
634 struct ikev2_keys *keys)
640 * {SK_d | SK_ai | SK_ar | SK_ei | SK_er | SK_pi | SK_pr } =
641 * prf+(SKEYSEED, Ni | Nr | SPIi | SPIr )
643 ikev2_free_keys(keys);
644 keys->SK_d_len = prf->key_len;
645 keys->SK_integ_len = integ->key_len;
646 keys->SK_encr_len = encr->key_len;
647 keys->SK_prf_len = prf->key_len;
649 keybuf_len = keys->SK_d_len + 2 * keys->SK_integ_len +
650 2 * keys->SK_encr_len + 2 * keys->SK_prf_len;
651 keybuf = os_malloc(keybuf_len);
655 if (ikev2_prf_plus(prf->id, skeyseed, prf->hash_len,
656 data, data_len, keybuf, keybuf_len)) {
663 keys->SK_d = os_malloc(keys->SK_d_len);
665 os_memcpy(keys->SK_d, pos, keys->SK_d_len);
666 wpa_hexdump_key(MSG_DEBUG, "IKEV2: SK_d",
667 keys->SK_d, keys->SK_d_len);
669 pos += keys->SK_d_len;
671 keys->SK_ai = os_malloc(keys->SK_integ_len);
673 os_memcpy(keys->SK_ai, pos, keys->SK_integ_len);
674 wpa_hexdump_key(MSG_DEBUG, "IKEV2: SK_ai",
675 keys->SK_ai, keys->SK_integ_len);
677 pos += keys->SK_integ_len;
679 keys->SK_ar = os_malloc(keys->SK_integ_len);
681 os_memcpy(keys->SK_ar, pos, keys->SK_integ_len);
682 wpa_hexdump_key(MSG_DEBUG, "IKEV2: SK_ar",
683 keys->SK_ar, keys->SK_integ_len);
685 pos += keys->SK_integ_len;
687 keys->SK_ei = os_malloc(keys->SK_encr_len);
689 os_memcpy(keys->SK_ei, pos, keys->SK_encr_len);
690 wpa_hexdump_key(MSG_DEBUG, "IKEV2: SK_ei",
691 keys->SK_ei, keys->SK_encr_len);
693 pos += keys->SK_encr_len;
695 keys->SK_er = os_malloc(keys->SK_encr_len);
697 os_memcpy(keys->SK_er, pos, keys->SK_encr_len);
698 wpa_hexdump_key(MSG_DEBUG, "IKEV2: SK_er",
699 keys->SK_er, keys->SK_encr_len);
701 pos += keys->SK_encr_len;
703 keys->SK_pi = os_malloc(keys->SK_prf_len);
705 os_memcpy(keys->SK_pi, pos, keys->SK_prf_len);
706 wpa_hexdump_key(MSG_DEBUG, "IKEV2: SK_pi",
707 keys->SK_pi, keys->SK_prf_len);
709 pos += keys->SK_prf_len;
711 keys->SK_pr = os_malloc(keys->SK_prf_len);
713 os_memcpy(keys->SK_pr, pos, keys->SK_prf_len);
714 wpa_hexdump_key(MSG_DEBUG, "IKEV2: SK_pr",
715 keys->SK_pr, keys->SK_prf_len);
720 if (!ikev2_keys_set(keys)) {
721 ikev2_free_keys(keys);