ikev2_common.c revision 214734
1189251Ssam/*
2189251Ssam * IKEv2 common routines for initiator and responder
3189251Ssam * Copyright (c) 2007, Jouni Malinen <j@w1.fi>
4189251Ssam *
5189251Ssam * This program is free software; you can redistribute it and/or modify
6189251Ssam * it under the terms of the GNU General Public License version 2 as
7189251Ssam * published by the Free Software Foundation.
8189251Ssam *
9189251Ssam * Alternatively, this software may be distributed under the terms of BSD
10189251Ssam * license.
11189251Ssam *
12189251Ssam * See README and COPYING for more details.
13189251Ssam */
14189251Ssam
15189251Ssam#include "includes.h"
16189251Ssam
17189251Ssam#include "common.h"
18214734Srpaulo#include "crypto/crypto.h"
19214734Srpaulo#include "crypto/md5.h"
20214734Srpaulo#include "crypto/sha1.h"
21189251Ssam#include "ikev2_common.h"
22189251Ssam
23189251Ssam
24189251Ssamstatic struct ikev2_integ_alg ikev2_integ_algs[] = {
25189251Ssam	{ AUTH_HMAC_SHA1_96, 20, 12 },
26189251Ssam	{ AUTH_HMAC_MD5_96, 16, 12 }
27189251Ssam};
28189251Ssam
29189251Ssam#define NUM_INTEG_ALGS (sizeof(ikev2_integ_algs) / sizeof(ikev2_integ_algs[0]))
30189251Ssam
31189251Ssam
32189251Ssamstatic struct ikev2_prf_alg ikev2_prf_algs[] = {
33189251Ssam	{ PRF_HMAC_SHA1, 20, 20 },
34189251Ssam	{ PRF_HMAC_MD5, 16, 16 }
35189251Ssam};
36189251Ssam
37189251Ssam#define NUM_PRF_ALGS (sizeof(ikev2_prf_algs) / sizeof(ikev2_prf_algs[0]))
38189251Ssam
39189251Ssam
40189251Ssamstatic struct ikev2_encr_alg ikev2_encr_algs[] = {
41189251Ssam	{ ENCR_AES_CBC, 16, 16 }, /* only 128-bit keys supported for now */
42189251Ssam	{ ENCR_3DES, 24, 8 }
43189251Ssam};
44189251Ssam
45189251Ssam#define NUM_ENCR_ALGS (sizeof(ikev2_encr_algs) / sizeof(ikev2_encr_algs[0]))
46189251Ssam
47189251Ssam
48189251Ssamconst struct ikev2_integ_alg * ikev2_get_integ(int id)
49189251Ssam{
50189251Ssam	size_t i;
51189251Ssam
52189251Ssam	for (i = 0; i < NUM_INTEG_ALGS; i++) {
53189251Ssam		if (ikev2_integ_algs[i].id == id)
54189251Ssam			return &ikev2_integ_algs[i];
55189251Ssam	}
56189251Ssam
57189251Ssam	return NULL;
58189251Ssam}
59189251Ssam
60189251Ssam
61189251Ssamint ikev2_integ_hash(int alg, const u8 *key, size_t key_len, const u8 *data,
62189251Ssam		     size_t data_len, u8 *hash)
63189251Ssam{
64189251Ssam	u8 tmphash[IKEV2_MAX_HASH_LEN];
65189251Ssam
66189251Ssam	switch (alg) {
67189251Ssam	case AUTH_HMAC_SHA1_96:
68189251Ssam		if (key_len != 20)
69189251Ssam			return -1;
70189251Ssam		hmac_sha1(key, key_len, data, data_len, tmphash);
71189251Ssam		os_memcpy(hash, tmphash, 12);
72189251Ssam		break;
73189251Ssam	case AUTH_HMAC_MD5_96:
74189251Ssam		if (key_len != 16)
75189251Ssam			return -1;
76189251Ssam		hmac_md5(key, key_len, data, data_len, tmphash);
77189251Ssam		os_memcpy(hash, tmphash, 12);
78189251Ssam		break;
79189251Ssam	default:
80189251Ssam		return -1;
81189251Ssam	}
82189251Ssam
83189251Ssam	return 0;
84189251Ssam}
85189251Ssam
86189251Ssam
87189251Ssamconst struct ikev2_prf_alg * ikev2_get_prf(int id)
88189251Ssam{
89189251Ssam	size_t i;
90189251Ssam
91189251Ssam	for (i = 0; i < NUM_PRF_ALGS; i++) {
92189251Ssam		if (ikev2_prf_algs[i].id == id)
93189251Ssam			return &ikev2_prf_algs[i];
94189251Ssam	}
95189251Ssam
96189251Ssam	return NULL;
97189251Ssam}
98189251Ssam
99189251Ssam
100189251Ssamint ikev2_prf_hash(int alg, const u8 *key, size_t key_len,
101189251Ssam		   size_t num_elem, const u8 *addr[], const size_t *len,
102189251Ssam		   u8 *hash)
103189251Ssam{
104189251Ssam	switch (alg) {
105189251Ssam	case PRF_HMAC_SHA1:
106189251Ssam		hmac_sha1_vector(key, key_len, num_elem, addr, len, hash);
107189251Ssam		break;
108189251Ssam	case PRF_HMAC_MD5:
109189251Ssam		hmac_md5_vector(key, key_len, num_elem, addr, len, hash);
110189251Ssam		break;
111189251Ssam	default:
112189251Ssam		return -1;
113189251Ssam	}
114189251Ssam
115189251Ssam	return 0;
116189251Ssam}
117189251Ssam
118189251Ssam
119189251Ssamint ikev2_prf_plus(int alg, const u8 *key, size_t key_len,
120189251Ssam		   const u8 *data, size_t data_len,
121189251Ssam		   u8 *out, size_t out_len)
122189251Ssam{
123189251Ssam	u8 hash[IKEV2_MAX_HASH_LEN];
124189251Ssam	size_t hash_len;
125189251Ssam	u8 iter, *pos, *end;
126189251Ssam	const u8 *addr[3];
127189251Ssam	size_t len[3];
128189251Ssam	const struct ikev2_prf_alg *prf;
129189251Ssam	int res;
130189251Ssam
131189251Ssam	prf = ikev2_get_prf(alg);
132189251Ssam	if (prf == NULL)
133189251Ssam		return -1;
134189251Ssam	hash_len = prf->hash_len;
135189251Ssam
136189251Ssam	addr[0] = hash;
137189251Ssam	len[0] = hash_len;
138189251Ssam	addr[1] = data;
139189251Ssam	len[1] = data_len;
140189251Ssam	addr[2] = &iter;
141189251Ssam	len[2] = 1;
142189251Ssam
143189251Ssam	pos = out;
144189251Ssam	end = out + out_len;
145189251Ssam	iter = 1;
146189251Ssam	while (pos < end) {
147189251Ssam		size_t clen;
148189251Ssam		if (iter == 1)
149189251Ssam			res = ikev2_prf_hash(alg, key, key_len, 2, &addr[1],
150189251Ssam					     &len[1], hash);
151189251Ssam		else
152189251Ssam			res = ikev2_prf_hash(alg, key, key_len, 3, addr, len,
153189251Ssam					     hash);
154189251Ssam		if (res < 0)
155189251Ssam			return -1;
156189251Ssam		clen = hash_len;
157189251Ssam		if ((int) clen > end - pos)
158189251Ssam			clen = end - pos;
159189251Ssam		os_memcpy(pos, hash, clen);
160189251Ssam		pos += clen;
161189251Ssam		iter++;
162189251Ssam	}
163189251Ssam
164189251Ssam	return 0;
165189251Ssam}
166189251Ssam
167189251Ssam
168189251Ssamconst struct ikev2_encr_alg * ikev2_get_encr(int id)
169189251Ssam{
170189251Ssam	size_t i;
171189251Ssam
172189251Ssam	for (i = 0; i < NUM_ENCR_ALGS; i++) {
173189251Ssam		if (ikev2_encr_algs[i].id == id)
174189251Ssam			return &ikev2_encr_algs[i];
175189251Ssam	}
176189251Ssam
177189251Ssam	return NULL;
178189251Ssam}
179189251Ssam
180189251Ssam
181189251Ssam#ifdef CCNS_PL
182189251Ssam/* from des.c */
183189251Ssamstruct des3_key_s {
184189251Ssam	u32 ek[3][32];
185189251Ssam	u32 dk[3][32];
186189251Ssam};
187189251Ssam
188189251Ssamvoid des3_key_setup(const u8 *key, struct des3_key_s *dkey);
189189251Ssamvoid des3_encrypt(const u8 *plain, const struct des3_key_s *key, u8 *crypt);
190189251Ssamvoid des3_decrypt(const u8 *crypt, const struct des3_key_s *key, u8 *plain);
191189251Ssam#endif /* CCNS_PL */
192189251Ssam
193189251Ssam
194189251Ssamint ikev2_encr_encrypt(int alg, const u8 *key, size_t key_len, const u8 *iv,
195189251Ssam		       const u8 *plain, u8 *crypt, size_t len)
196189251Ssam{
197189251Ssam	struct crypto_cipher *cipher;
198189251Ssam	int encr_alg;
199189251Ssam
200189251Ssam#ifdef CCNS_PL
201189251Ssam	if (alg == ENCR_3DES) {
202189251Ssam		struct des3_key_s des3key;
203189251Ssam		size_t i, blocks;
204189251Ssam		u8 *pos;
205189251Ssam
206189251Ssam		/* ECB mode is used incorrectly for 3DES!? */
207189251Ssam		if (key_len != 24) {
208189251Ssam			wpa_printf(MSG_INFO, "IKEV2: Invalid encr key length");
209189251Ssam			return -1;
210189251Ssam		}
211189251Ssam		des3_key_setup(key, &des3key);
212189251Ssam
213189251Ssam		blocks = len / 8;
214189251Ssam		pos = crypt;
215189251Ssam		for (i = 0; i < blocks; i++) {
216189251Ssam			des3_encrypt(pos, &des3key, pos);
217189251Ssam			pos += 8;
218189251Ssam		}
219189251Ssam	} else {
220189251Ssam#endif /* CCNS_PL */
221189251Ssam	switch (alg) {
222189251Ssam	case ENCR_3DES:
223189251Ssam		encr_alg = CRYPTO_CIPHER_ALG_3DES;
224189251Ssam		break;
225189251Ssam	case ENCR_AES_CBC:
226189251Ssam		encr_alg = CRYPTO_CIPHER_ALG_AES;
227189251Ssam		break;
228189251Ssam	default:
229189251Ssam		wpa_printf(MSG_DEBUG, "IKEV2: Unsupported encr alg %d", alg);
230189251Ssam		return -1;
231189251Ssam	}
232189251Ssam
233189251Ssam	cipher = crypto_cipher_init(encr_alg, iv, key, key_len);
234189251Ssam	if (cipher == NULL) {
235189251Ssam		wpa_printf(MSG_INFO, "IKEV2: Failed to initialize cipher");
236189251Ssam		return -1;
237189251Ssam	}
238189251Ssam
239189251Ssam	if (crypto_cipher_encrypt(cipher, plain, crypt, len) < 0) {
240189251Ssam		wpa_printf(MSG_INFO, "IKEV2: Encryption failed");
241189251Ssam		crypto_cipher_deinit(cipher);
242189251Ssam		return -1;
243189251Ssam	}
244189251Ssam	crypto_cipher_deinit(cipher);
245189251Ssam#ifdef CCNS_PL
246189251Ssam	}
247189251Ssam#endif /* CCNS_PL */
248189251Ssam
249189251Ssam	return 0;
250189251Ssam}
251189251Ssam
252189251Ssam
253189251Ssamint ikev2_encr_decrypt(int alg, const u8 *key, size_t key_len, const u8 *iv,
254189251Ssam		       const u8 *crypt, u8 *plain, size_t len)
255189251Ssam{
256189251Ssam	struct crypto_cipher *cipher;
257189251Ssam	int encr_alg;
258189251Ssam
259189251Ssam#ifdef CCNS_PL
260189251Ssam	if (alg == ENCR_3DES) {
261189251Ssam		struct des3_key_s des3key;
262189251Ssam		size_t i, blocks;
263189251Ssam
264189251Ssam		/* ECB mode is used incorrectly for 3DES!? */
265189251Ssam		if (key_len != 24) {
266189251Ssam			wpa_printf(MSG_INFO, "IKEV2: Invalid encr key length");
267189251Ssam			return -1;
268189251Ssam		}
269189251Ssam		des3_key_setup(key, &des3key);
270189251Ssam
271189251Ssam		if (len % 8) {
272189251Ssam			wpa_printf(MSG_INFO, "IKEV2: Invalid encrypted "
273189251Ssam				   "length");
274189251Ssam			return -1;
275189251Ssam		}
276189251Ssam		blocks = len / 8;
277189251Ssam		for (i = 0; i < blocks; i++) {
278189251Ssam			des3_decrypt(crypt, &des3key, plain);
279189251Ssam			plain += 8;
280189251Ssam			crypt += 8;
281189251Ssam		}
282189251Ssam	} else {
283189251Ssam#endif /* CCNS_PL */
284189251Ssam	switch (alg) {
285189251Ssam	case ENCR_3DES:
286189251Ssam		encr_alg = CRYPTO_CIPHER_ALG_3DES;
287189251Ssam		break;
288189251Ssam	case ENCR_AES_CBC:
289189251Ssam		encr_alg = CRYPTO_CIPHER_ALG_AES;
290189251Ssam		break;
291189251Ssam	default:
292189251Ssam		wpa_printf(MSG_DEBUG, "IKEV2: Unsupported encr alg %d", alg);
293189251Ssam		return -1;
294189251Ssam	}
295189251Ssam
296189251Ssam	cipher = crypto_cipher_init(encr_alg, iv, key, key_len);
297189251Ssam	if (cipher == NULL) {
298189251Ssam		wpa_printf(MSG_INFO, "IKEV2: Failed to initialize cipher");
299189251Ssam		return -1;
300189251Ssam	}
301189251Ssam
302189251Ssam	if (crypto_cipher_decrypt(cipher, crypt, plain, len) < 0) {
303189251Ssam		wpa_printf(MSG_INFO, "IKEV2: Decryption failed");
304189251Ssam		crypto_cipher_deinit(cipher);
305189251Ssam		return -1;
306189251Ssam	}
307189251Ssam	crypto_cipher_deinit(cipher);
308189251Ssam#ifdef CCNS_PL
309189251Ssam	}
310189251Ssam#endif /* CCNS_PL */
311189251Ssam
312189251Ssam	return 0;
313189251Ssam}
314189251Ssam
315189251Ssam
316189251Ssamint ikev2_parse_payloads(struct ikev2_payloads *payloads,
317189251Ssam			 u8 next_payload, const u8 *pos, const u8 *end)
318189251Ssam{
319189251Ssam	const struct ikev2_payload_hdr *phdr;
320189251Ssam
321189251Ssam	os_memset(payloads, 0, sizeof(*payloads));
322189251Ssam
323189251Ssam	while (next_payload != IKEV2_PAYLOAD_NO_NEXT_PAYLOAD) {
324189251Ssam		int plen, pdatalen;
325189251Ssam		const u8 *pdata;
326189251Ssam		wpa_printf(MSG_DEBUG, "IKEV2: Processing payload %u",
327189251Ssam			   next_payload);
328189251Ssam		if (end - pos < (int) sizeof(*phdr)) {
329189251Ssam			wpa_printf(MSG_INFO, "IKEV2:   Too short message for "
330189251Ssam				   "payload header (left=%ld)",
331189251Ssam				   (long) (end - pos));
332189251Ssam		}
333189251Ssam		phdr = (const struct ikev2_payload_hdr *) pos;
334189251Ssam		plen = WPA_GET_BE16(phdr->payload_length);
335189251Ssam		if (plen < (int) sizeof(*phdr) || pos + plen > end) {
336189251Ssam			wpa_printf(MSG_INFO, "IKEV2:   Invalid payload header "
337189251Ssam				   "length %d", plen);
338189251Ssam			return -1;
339189251Ssam		}
340189251Ssam
341189251Ssam		wpa_printf(MSG_DEBUG, "IKEV2:   Next Payload: %u  Flags: 0x%x"
342189251Ssam			   "  Payload Length: %d",
343189251Ssam			   phdr->next_payload, phdr->flags, plen);
344189251Ssam
345189251Ssam		pdata = (const u8 *) (phdr + 1);
346189251Ssam		pdatalen = plen - sizeof(*phdr);
347189251Ssam
348189251Ssam		switch (next_payload) {
349189251Ssam		case IKEV2_PAYLOAD_SA:
350189251Ssam			wpa_printf(MSG_DEBUG, "IKEV2:   Payload: Security "
351189251Ssam				   "Association");
352189251Ssam			payloads->sa = pdata;
353189251Ssam			payloads->sa_len = pdatalen;
354189251Ssam			break;
355189251Ssam		case IKEV2_PAYLOAD_KEY_EXCHANGE:
356189251Ssam			wpa_printf(MSG_DEBUG, "IKEV2:   Payload: Key "
357189251Ssam				   "Exchange");
358189251Ssam			payloads->ke = pdata;
359189251Ssam			payloads->ke_len = pdatalen;
360189251Ssam			break;
361189251Ssam		case IKEV2_PAYLOAD_IDi:
362189251Ssam			wpa_printf(MSG_DEBUG, "IKEV2:   Payload: IDi");
363189251Ssam			payloads->idi = pdata;
364189251Ssam			payloads->idi_len = pdatalen;
365189251Ssam			break;
366189251Ssam		case IKEV2_PAYLOAD_IDr:
367189251Ssam			wpa_printf(MSG_DEBUG, "IKEV2:   Payload: IDr");
368189251Ssam			payloads->idr = pdata;
369189251Ssam			payloads->idr_len = pdatalen;
370189251Ssam			break;
371189251Ssam		case IKEV2_PAYLOAD_CERTIFICATE:
372189251Ssam			wpa_printf(MSG_DEBUG, "IKEV2:   Payload: Certificate");
373189251Ssam			payloads->cert = pdata;
374189251Ssam			payloads->cert_len = pdatalen;
375189251Ssam			break;
376189251Ssam		case IKEV2_PAYLOAD_AUTHENTICATION:
377189251Ssam			wpa_printf(MSG_DEBUG, "IKEV2:   Payload: "
378189251Ssam				   "Authentication");
379189251Ssam			payloads->auth = pdata;
380189251Ssam			payloads->auth_len = pdatalen;
381189251Ssam			break;
382189251Ssam		case IKEV2_PAYLOAD_NONCE:
383189251Ssam			wpa_printf(MSG_DEBUG, "IKEV2:   Payload: Nonce");
384189251Ssam			payloads->nonce = pdata;
385189251Ssam			payloads->nonce_len = pdatalen;
386189251Ssam			break;
387189251Ssam		case IKEV2_PAYLOAD_ENCRYPTED:
388189251Ssam			wpa_printf(MSG_DEBUG, "IKEV2:   Payload: Encrypted");
389189251Ssam			payloads->encrypted = pdata;
390189251Ssam			payloads->encrypted_len = pdatalen;
391189251Ssam			break;
392189251Ssam		case IKEV2_PAYLOAD_NOTIFICATION:
393189251Ssam			wpa_printf(MSG_DEBUG, "IKEV2:   Payload: "
394189251Ssam				   "Notification");
395189251Ssam			payloads->notification = pdata;
396189251Ssam			payloads->notification_len = pdatalen;
397189251Ssam			break;
398189251Ssam		default:
399189251Ssam			if (phdr->flags & IKEV2_PAYLOAD_FLAGS_CRITICAL) {
400189251Ssam				wpa_printf(MSG_INFO, "IKEV2:   Unsupported "
401189251Ssam					   "critical payload %u - reject the "
402189251Ssam					   "entire message", next_payload);
403189251Ssam				return -1;
404189251Ssam			} else {
405189251Ssam				wpa_printf(MSG_DEBUG, "IKEV2:   Skipped "
406189251Ssam					   "unsupported payload %u",
407189251Ssam					   next_payload);
408189251Ssam			}
409189251Ssam		}
410189251Ssam
411189251Ssam		if (next_payload == IKEV2_PAYLOAD_ENCRYPTED &&
412189251Ssam		    pos + plen == end) {
413189251Ssam			/*
414189251Ssam			 * Next Payload in the case of Encrypted Payload is
415189251Ssam			 * actually the payload type for the first embedded
416189251Ssam			 * payload.
417189251Ssam			 */
418189251Ssam			payloads->encr_next_payload = phdr->next_payload;
419189251Ssam			next_payload = IKEV2_PAYLOAD_NO_NEXT_PAYLOAD;
420189251Ssam		} else
421189251Ssam			next_payload = phdr->next_payload;
422189251Ssam
423189251Ssam		pos += plen;
424189251Ssam	}
425189251Ssam
426189251Ssam	if (pos != end) {
427189251Ssam		wpa_printf(MSG_INFO, "IKEV2: Unexpected extra data after "
428189251Ssam			   "payloads");
429189251Ssam		return -1;
430189251Ssam	}
431189251Ssam
432189251Ssam	return 0;
433189251Ssam}
434189251Ssam
435189251Ssam
436189251Ssamint ikev2_derive_auth_data(int prf_alg, const struct wpabuf *sign_msg,
437189251Ssam			   const u8 *ID, size_t ID_len, u8 ID_type,
438189251Ssam			   struct ikev2_keys *keys, int initiator,
439189251Ssam			   const u8 *shared_secret, size_t shared_secret_len,
440189251Ssam			   const u8 *nonce, size_t nonce_len,
441189251Ssam			   const u8 *key_pad, size_t key_pad_len,
442189251Ssam			   u8 *auth_data)
443189251Ssam{
444189251Ssam	size_t sign_len, buf_len;
445189251Ssam	u8 *sign_data, *pos, *buf, hash[IKEV2_MAX_HASH_LEN];
446189251Ssam	const struct ikev2_prf_alg *prf;
447189251Ssam	const u8 *SK_p = initiator ? keys->SK_pi : keys->SK_pr;
448189251Ssam
449189251Ssam	prf = ikev2_get_prf(prf_alg);
450189251Ssam	if (sign_msg == NULL || ID == NULL || SK_p == NULL ||
451189251Ssam	    shared_secret == NULL || nonce == NULL || prf == NULL)
452189251Ssam		return -1;
453189251Ssam
454189251Ssam	/* prf(SK_pi/r,IDi/r') */
455189251Ssam	buf_len = 4 + ID_len;
456189251Ssam	buf = os_zalloc(buf_len);
457189251Ssam	if (buf == NULL)
458189251Ssam		return -1;
459189251Ssam	buf[0] = ID_type;
460189251Ssam	os_memcpy(buf + 4, ID, ID_len);
461189251Ssam	if (ikev2_prf_hash(prf->id, SK_p, keys->SK_prf_len,
462189251Ssam			   1, (const u8 **) &buf, &buf_len, hash) < 0) {
463189251Ssam		os_free(buf);
464189251Ssam		return -1;
465189251Ssam	}
466189251Ssam	os_free(buf);
467189251Ssam
468189251Ssam	/* sign_data = msg | Nr/i | prf(SK_pi/r,IDi/r') */
469189251Ssam	sign_len = wpabuf_len(sign_msg) + nonce_len + prf->hash_len;
470189251Ssam	sign_data = os_malloc(sign_len);
471189251Ssam	if (sign_data == NULL)
472189251Ssam		return -1;
473189251Ssam	pos = sign_data;
474189251Ssam	os_memcpy(pos, wpabuf_head(sign_msg), wpabuf_len(sign_msg));
475189251Ssam	pos += wpabuf_len(sign_msg);
476189251Ssam	os_memcpy(pos, nonce, nonce_len);
477189251Ssam	pos += nonce_len;
478189251Ssam	os_memcpy(pos, hash, prf->hash_len);
479189251Ssam
480189251Ssam	/* AUTH = prf(prf(Shared Secret, key pad, sign_data) */
481189251Ssam	if (ikev2_prf_hash(prf->id, shared_secret, shared_secret_len, 1,
482189251Ssam			   &key_pad, &key_pad_len, hash) < 0 ||
483189251Ssam	    ikev2_prf_hash(prf->id, hash, prf->hash_len, 1,
484189251Ssam			   (const u8 **) &sign_data, &sign_len, auth_data) < 0)
485189251Ssam	{
486189251Ssam		os_free(sign_data);
487189251Ssam		return -1;
488189251Ssam	}
489189251Ssam	os_free(sign_data);
490189251Ssam
491189251Ssam	return 0;
492189251Ssam}
493189251Ssam
494189251Ssam
495189251Ssamu8 * ikev2_decrypt_payload(int encr_id, int integ_id,
496189251Ssam			   struct ikev2_keys *keys, int initiator,
497189251Ssam			   const struct ikev2_hdr *hdr,
498189251Ssam			   const u8 *encrypted, size_t encrypted_len,
499189251Ssam			   size_t *res_len)
500189251Ssam{
501189251Ssam	size_t iv_len;
502189251Ssam	const u8 *pos, *end, *iv, *integ;
503189251Ssam	u8 hash[IKEV2_MAX_HASH_LEN], *decrypted;
504189251Ssam	size_t decrypted_len, pad_len;
505189251Ssam	const struct ikev2_integ_alg *integ_alg;
506189251Ssam	const struct ikev2_encr_alg *encr_alg;
507189251Ssam	const u8 *SK_e = initiator ? keys->SK_ei : keys->SK_er;
508189251Ssam	const u8 *SK_a = initiator ? keys->SK_ai : keys->SK_ar;
509189251Ssam
510189251Ssam	if (encrypted == NULL) {
511189251Ssam		wpa_printf(MSG_INFO, "IKEV2: No Encrypted payload in SA_AUTH");
512189251Ssam		return NULL;
513189251Ssam	}
514189251Ssam
515189251Ssam	encr_alg = ikev2_get_encr(encr_id);
516189251Ssam	if (encr_alg == NULL) {
517189251Ssam		wpa_printf(MSG_INFO, "IKEV2: Unsupported encryption type");
518189251Ssam		return NULL;
519189251Ssam	}
520189251Ssam	iv_len = encr_alg->block_size;
521189251Ssam
522189251Ssam	integ_alg = ikev2_get_integ(integ_id);
523189251Ssam	if (integ_alg == NULL) {
524189251Ssam		wpa_printf(MSG_INFO, "IKEV2: Unsupported intergrity type");
525189251Ssam		return NULL;
526189251Ssam	}
527189251Ssam
528189251Ssam	if (encrypted_len < iv_len + 1 + integ_alg->hash_len) {
529189251Ssam		wpa_printf(MSG_INFO, "IKEV2: No room for IV or Integrity "
530189251Ssam			  "Checksum");
531189251Ssam		return NULL;
532189251Ssam	}
533189251Ssam
534189251Ssam	iv = encrypted;
535189251Ssam	pos = iv + iv_len;
536189251Ssam	end = encrypted + encrypted_len;
537189251Ssam	integ = end - integ_alg->hash_len;
538189251Ssam
539189251Ssam	if (SK_a == NULL) {
540189251Ssam		wpa_printf(MSG_INFO, "IKEV2: No SK_a available");
541189251Ssam		return NULL;
542189251Ssam	}
543189251Ssam	if (ikev2_integ_hash(integ_id, SK_a, keys->SK_integ_len,
544189251Ssam			     (const u8 *) hdr,
545189251Ssam			     integ - (const u8 *) hdr, hash) < 0) {
546189251Ssam		wpa_printf(MSG_INFO, "IKEV2: Failed to calculate integrity "
547189251Ssam			   "hash");
548189251Ssam		return NULL;
549189251Ssam	}
550189251Ssam	if (os_memcmp(integ, hash, integ_alg->hash_len) != 0) {
551189251Ssam		wpa_printf(MSG_INFO, "IKEV2: Incorrect Integrity Checksum "
552189251Ssam			   "Data");
553189251Ssam		return NULL;
554189251Ssam	}
555189251Ssam
556189251Ssam	if (SK_e == NULL) {
557189251Ssam		wpa_printf(MSG_INFO, "IKEV2: No SK_e available");
558189251Ssam		return NULL;
559189251Ssam	}
560189251Ssam
561189251Ssam	decrypted_len = integ - pos;
562189251Ssam	decrypted = os_malloc(decrypted_len);
563189251Ssam	if (decrypted == NULL)
564189251Ssam		return NULL;
565189251Ssam
566189251Ssam	if (ikev2_encr_decrypt(encr_alg->id, SK_e, keys->SK_encr_len, iv, pos,
567189251Ssam			       decrypted, decrypted_len) < 0) {
568189251Ssam		os_free(decrypted);
569189251Ssam		return NULL;
570189251Ssam	}
571189251Ssam
572189251Ssam	pad_len = decrypted[decrypted_len - 1];
573189251Ssam	if (decrypted_len < pad_len + 1) {
574189251Ssam		wpa_printf(MSG_INFO, "IKEV2: Invalid padding in encrypted "
575189251Ssam			   "payload");
576189251Ssam		os_free(decrypted);
577189251Ssam		return NULL;
578189251Ssam	}
579189251Ssam
580189251Ssam	decrypted_len -= pad_len + 1;
581189251Ssam
582189251Ssam	*res_len = decrypted_len;
583189251Ssam	return decrypted;
584189251Ssam}
585189251Ssam
586189251Ssam
587189251Ssamvoid ikev2_update_hdr(struct wpabuf *msg)
588189251Ssam{
589189251Ssam	struct ikev2_hdr *hdr;
590189251Ssam
591189251Ssam	/* Update lenth field in HDR */
592189251Ssam	hdr = wpabuf_mhead(msg);
593189251Ssam	WPA_PUT_BE32(hdr->length, wpabuf_len(msg));
594189251Ssam}
595189251Ssam
596189251Ssam
597189251Ssamint ikev2_build_encrypted(int encr_id, int integ_id, struct ikev2_keys *keys,
598189251Ssam			  int initiator, struct wpabuf *msg,
599189251Ssam			  struct wpabuf *plain, u8 next_payload)
600189251Ssam{
601189251Ssam	struct ikev2_payload_hdr *phdr;
602189251Ssam	size_t plen;
603189251Ssam	size_t iv_len, pad_len;
604189251Ssam	u8 *icv, *iv;
605189251Ssam	const struct ikev2_integ_alg *integ_alg;
606189251Ssam	const struct ikev2_encr_alg *encr_alg;
607189251Ssam	const u8 *SK_e = initiator ? keys->SK_ei : keys->SK_er;
608189251Ssam	const u8 *SK_a = initiator ? keys->SK_ai : keys->SK_ar;
609189251Ssam
610189251Ssam	wpa_printf(MSG_DEBUG, "IKEV2: Adding Encrypted payload");
611189251Ssam
612189251Ssam	/* Encr - RFC 4306, Sect. 3.14 */
613189251Ssam
614189251Ssam	encr_alg = ikev2_get_encr(encr_id);
615189251Ssam	if (encr_alg == NULL) {
616189251Ssam		wpa_printf(MSG_INFO, "IKEV2: Unsupported encryption type");
617189251Ssam		return -1;
618189251Ssam	}
619189251Ssam	iv_len = encr_alg->block_size;
620189251Ssam
621189251Ssam	integ_alg = ikev2_get_integ(integ_id);
622189251Ssam	if (integ_alg == NULL) {
623189251Ssam		wpa_printf(MSG_INFO, "IKEV2: Unsupported intergrity type");
624189251Ssam		return -1;
625189251Ssam	}
626189251Ssam
627189251Ssam	if (SK_e == NULL) {
628189251Ssam		wpa_printf(MSG_INFO, "IKEV2: No SK_e available");
629189251Ssam		return -1;
630189251Ssam	}
631189251Ssam
632189251Ssam	if (SK_a == NULL) {
633189251Ssam		wpa_printf(MSG_INFO, "IKEV2: No SK_a available");
634189251Ssam		return -1;
635189251Ssam	}
636189251Ssam
637189251Ssam	phdr = wpabuf_put(msg, sizeof(*phdr));
638189251Ssam	phdr->next_payload = next_payload;
639189251Ssam	phdr->flags = 0;
640189251Ssam
641189251Ssam	iv = wpabuf_put(msg, iv_len);
642189251Ssam	if (os_get_random(iv, iv_len)) {
643189251Ssam		wpa_printf(MSG_INFO, "IKEV2: Could not generate IV");
644189251Ssam		return -1;
645189251Ssam	}
646189251Ssam
647189251Ssam	pad_len = iv_len - (wpabuf_len(plain) + 1) % iv_len;
648189251Ssam	if (pad_len == iv_len)
649189251Ssam		pad_len = 0;
650189251Ssam	wpabuf_put(plain, pad_len);
651189251Ssam	wpabuf_put_u8(plain, pad_len);
652189251Ssam
653189251Ssam	if (ikev2_encr_encrypt(encr_alg->id, SK_e, keys->SK_encr_len, iv,
654189251Ssam			       wpabuf_head(plain), wpabuf_mhead(plain),
655189251Ssam			       wpabuf_len(plain)) < 0)
656189251Ssam		return -1;
657189251Ssam
658189251Ssam	wpabuf_put_buf(msg, plain);
659189251Ssam
660189251Ssam	/* Need to update all headers (Length fields) prior to hash func */
661189251Ssam	icv = wpabuf_put(msg, integ_alg->hash_len);
662189251Ssam	plen = (u8 *) wpabuf_put(msg, 0) - (u8 *) phdr;
663189251Ssam	WPA_PUT_BE16(phdr->payload_length, plen);
664189251Ssam
665189251Ssam	ikev2_update_hdr(msg);
666189251Ssam
667189251Ssam	return ikev2_integ_hash(integ_id, SK_a, keys->SK_integ_len,
668189251Ssam				wpabuf_head(msg),
669189251Ssam				wpabuf_len(msg) - integ_alg->hash_len, icv);
670189251Ssam
671189251Ssam	return 0;
672189251Ssam}
673189251Ssam
674189251Ssam
675189251Ssamint ikev2_keys_set(struct ikev2_keys *keys)
676189251Ssam{
677189251Ssam	return keys->SK_d && keys->SK_ai && keys->SK_ar && keys->SK_ei &&
678189251Ssam		keys->SK_er && keys->SK_pi && keys->SK_pr;
679189251Ssam}
680189251Ssam
681189251Ssam
682189251Ssamvoid ikev2_free_keys(struct ikev2_keys *keys)
683189251Ssam{
684189251Ssam	os_free(keys->SK_d);
685189251Ssam	os_free(keys->SK_ai);
686189251Ssam	os_free(keys->SK_ar);
687189251Ssam	os_free(keys->SK_ei);
688189251Ssam	os_free(keys->SK_er);
689189251Ssam	os_free(keys->SK_pi);
690189251Ssam	os_free(keys->SK_pr);
691189251Ssam	keys->SK_d = keys->SK_ai = keys->SK_ar = keys->SK_ei = keys->SK_er =
692189251Ssam		keys->SK_pi = keys->SK_pr = NULL;
693189251Ssam}
694189251Ssam
695189251Ssam
696189251Ssamint ikev2_derive_sk_keys(const struct ikev2_prf_alg *prf,
697189251Ssam			 const struct ikev2_integ_alg *integ,
698189251Ssam			 const struct ikev2_encr_alg *encr,
699189251Ssam			 const u8 *skeyseed, const u8 *data, size_t data_len,
700189251Ssam			 struct ikev2_keys *keys)
701189251Ssam{
702189251Ssam	u8 *keybuf, *pos;
703189251Ssam	size_t keybuf_len;
704189251Ssam
705189251Ssam	/*
706189251Ssam	 * {SK_d | SK_ai | SK_ar | SK_ei | SK_er | SK_pi | SK_pr } =
707189251Ssam	 *	prf+(SKEYSEED, Ni | Nr | SPIi | SPIr )
708189251Ssam	 */
709189251Ssam	ikev2_free_keys(keys);
710189251Ssam	keys->SK_d_len = prf->key_len;
711189251Ssam	keys->SK_integ_len = integ->key_len;
712189251Ssam	keys->SK_encr_len = encr->key_len;
713189251Ssam	keys->SK_prf_len = prf->key_len;
714189251Ssam#ifdef CCNS_PL
715189251Ssam	/* Uses encryption key length for SK_d; should be PRF length */
716189251Ssam	keys->SK_d_len = keys->SK_encr_len;
717189251Ssam#endif /* CCNS_PL */
718189251Ssam
719189251Ssam	keybuf_len = keys->SK_d_len + 2 * keys->SK_integ_len +
720189251Ssam		2 * keys->SK_encr_len + 2 * keys->SK_prf_len;
721189251Ssam	keybuf = os_malloc(keybuf_len);
722189251Ssam	if (keybuf == NULL)
723189251Ssam		return -1;
724189251Ssam
725189251Ssam	if (ikev2_prf_plus(prf->id, skeyseed, prf->hash_len,
726189251Ssam			   data, data_len, keybuf, keybuf_len)) {
727189251Ssam		os_free(keybuf);
728189251Ssam		return -1;
729189251Ssam	}
730189251Ssam
731189251Ssam	pos = keybuf;
732189251Ssam
733189251Ssam	keys->SK_d = os_malloc(keys->SK_d_len);
734189251Ssam	if (keys->SK_d) {
735189251Ssam		os_memcpy(keys->SK_d, pos, keys->SK_d_len);
736189251Ssam		wpa_hexdump_key(MSG_DEBUG, "IKEV2: SK_d",
737189251Ssam				keys->SK_d, keys->SK_d_len);
738189251Ssam	}
739189251Ssam	pos += keys->SK_d_len;
740189251Ssam
741189251Ssam	keys->SK_ai = os_malloc(keys->SK_integ_len);
742189251Ssam	if (keys->SK_ai) {
743189251Ssam		os_memcpy(keys->SK_ai, pos, keys->SK_integ_len);
744189251Ssam		wpa_hexdump_key(MSG_DEBUG, "IKEV2: SK_ai",
745189251Ssam				keys->SK_ai, keys->SK_integ_len);
746189251Ssam	}
747189251Ssam	pos += keys->SK_integ_len;
748189251Ssam
749189251Ssam	keys->SK_ar = os_malloc(keys->SK_integ_len);
750189251Ssam	if (keys->SK_ar) {
751189251Ssam		os_memcpy(keys->SK_ar, pos, keys->SK_integ_len);
752189251Ssam		wpa_hexdump_key(MSG_DEBUG, "IKEV2: SK_ar",
753189251Ssam				keys->SK_ar, keys->SK_integ_len);
754189251Ssam	}
755189251Ssam	pos += keys->SK_integ_len;
756189251Ssam
757189251Ssam	keys->SK_ei = os_malloc(keys->SK_encr_len);
758189251Ssam	if (keys->SK_ei) {
759189251Ssam		os_memcpy(keys->SK_ei, pos, keys->SK_encr_len);
760189251Ssam		wpa_hexdump_key(MSG_DEBUG, "IKEV2: SK_ei",
761189251Ssam				keys->SK_ei, keys->SK_encr_len);
762189251Ssam	}
763189251Ssam	pos += keys->SK_encr_len;
764189251Ssam
765189251Ssam	keys->SK_er = os_malloc(keys->SK_encr_len);
766189251Ssam	if (keys->SK_er) {
767189251Ssam		os_memcpy(keys->SK_er, pos, keys->SK_encr_len);
768189251Ssam		wpa_hexdump_key(MSG_DEBUG, "IKEV2: SK_er",
769189251Ssam				keys->SK_er, keys->SK_encr_len);
770189251Ssam	}
771189251Ssam	pos += keys->SK_encr_len;
772189251Ssam
773189251Ssam	keys->SK_pi = os_malloc(keys->SK_prf_len);
774189251Ssam	if (keys->SK_pi) {
775189251Ssam		os_memcpy(keys->SK_pi, pos, keys->SK_prf_len);
776189251Ssam		wpa_hexdump_key(MSG_DEBUG, "IKEV2: SK_pi",
777189251Ssam				keys->SK_pi, keys->SK_prf_len);
778189251Ssam	}
779189251Ssam	pos += keys->SK_prf_len;
780189251Ssam
781189251Ssam	keys->SK_pr = os_malloc(keys->SK_prf_len);
782189251Ssam	if (keys->SK_pr) {
783189251Ssam		os_memcpy(keys->SK_pr, pos, keys->SK_prf_len);
784189251Ssam		wpa_hexdump_key(MSG_DEBUG, "IKEV2: SK_pr",
785189251Ssam				keys->SK_pr, keys->SK_prf_len);
786189251Ssam	}
787189251Ssam
788189251Ssam	os_free(keybuf);
789189251Ssam
790189251Ssam	if (!ikev2_keys_set(keys)) {
791189251Ssam		ikev2_free_keys(keys);
792189251Ssam		return -1;
793189251Ssam	}
794189251Ssam
795189251Ssam	return 0;
796189251Ssam}
797