1 /*
2  * WPA Supplicant - PeerKey for Direct Link Setup (DLS)
3  * Copyright (c) 2006-2015, Jouni Malinen <j@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 #ifdef CONFIG_PEERKEY
12 
13 #include "common.h"
14 #include "eloop.h"
15 #include "crypto/sha1.h"
16 #include "crypto/sha256.h"
17 #include "crypto/random.h"
18 #include "common/ieee802_11_defs.h"
19 #include "wpa.h"
20 #include "wpa_i.h"
21 #include "wpa_ie.h"
22 #include "peerkey.h"
23 
24 
wpa_add_ie(u8 * pos,const u8 * ie,size_t ie_len)25 static u8 * wpa_add_ie(u8 *pos, const u8 *ie, size_t ie_len)
26 {
27 	os_memcpy(pos, ie, ie_len);
28 	return pos + ie_len;
29 }
30 
31 
wpa_add_kde(u8 * pos,u32 kde,const u8 * data,size_t data_len)32 static u8 * wpa_add_kde(u8 *pos, u32 kde, const u8 *data, size_t data_len)
33 {
34 	*pos++ = WLAN_EID_VENDOR_SPECIFIC;
35 	*pos++ = RSN_SELECTOR_LEN + data_len;
36 	RSN_SELECTOR_PUT(pos, kde);
37 	pos += RSN_SELECTOR_LEN;
38 	os_memcpy(pos, data, data_len);
39 	pos += data_len;
40 	return pos;
41 }
42 
43 
wpa_supplicant_smk_timeout(void * eloop_ctx,void * timeout_ctx)44 static void wpa_supplicant_smk_timeout(void *eloop_ctx, void *timeout_ctx)
45 {
46 #if 0
47 	struct wpa_sm *sm = eloop_ctx;
48 	struct wpa_peerkey *peerkey = timeout_ctx;
49 #endif
50 	/* TODO: time out SMK and any STK that was generated using this SMK */
51 }
52 
53 
wpa_supplicant_peerkey_free(struct wpa_sm * sm,struct wpa_peerkey * peerkey)54 static void wpa_supplicant_peerkey_free(struct wpa_sm *sm,
55 					struct wpa_peerkey *peerkey)
56 {
57 	eloop_cancel_timeout(wpa_supplicant_smk_timeout, sm, peerkey);
58 	os_free(peerkey);
59 }
60 
61 
wpa_supplicant_send_smk_error(struct wpa_sm * sm,const u8 * dst,const u8 * peer,u16 mui,u16 error_type,int ver)62 static int wpa_supplicant_send_smk_error(struct wpa_sm *sm, const u8 *dst,
63 					 const u8 *peer,
64 					 u16 mui, u16 error_type, int ver)
65 {
66 	size_t rlen;
67 	struct wpa_eapol_key *err;
68 	struct wpa_eapol_key_192 *err192;
69 	struct rsn_error_kde error;
70 	u8 *rbuf, *pos;
71 	size_t kde_len;
72 	u16 key_info;
73 
74 	kde_len = 2 + RSN_SELECTOR_LEN + sizeof(error);
75 	if (peer)
76 		kde_len += 2 + RSN_SELECTOR_LEN + ETH_ALEN;
77 
78 	rbuf = wpa_sm_alloc_eapol(sm, IEEE802_1X_TYPE_EAPOL_KEY,
79 				  NULL, sizeof(*err) + kde_len, &rlen,
80 				  (void *) &err);
81 	if (rbuf == NULL)
82 		return -1;
83 	err192 = (struct wpa_eapol_key_192 *) err;
84 
85 	err->type = EAPOL_KEY_TYPE_RSN;
86 	key_info = ver | WPA_KEY_INFO_SMK_MESSAGE | WPA_KEY_INFO_MIC |
87 		WPA_KEY_INFO_SECURE | WPA_KEY_INFO_ERROR |
88 		WPA_KEY_INFO_REQUEST;
89 	WPA_PUT_BE16(err->key_info, key_info);
90 	WPA_PUT_BE16(err->key_length, 0);
91 	os_memcpy(err->replay_counter, sm->request_counter,
92 		  WPA_REPLAY_COUNTER_LEN);
93 	inc_byte_array(sm->request_counter, WPA_REPLAY_COUNTER_LEN);
94 
95 	WPA_PUT_BE16(err->key_data_length, (u16) kde_len);
96 	pos = (u8 *) (err + 1);
97 
98 	if (peer) {
99 		/* Peer MAC Address KDE */
100 		pos = wpa_add_kde(pos, RSN_KEY_DATA_MAC_ADDR, peer, ETH_ALEN);
101 	}
102 
103 	/* Error KDE */
104 	error.mui = host_to_be16(mui);
105 	error.error_type = host_to_be16(error_type);
106 	wpa_add_kde(pos, RSN_KEY_DATA_ERROR, (u8 *) &error, sizeof(error));
107 
108 	if (peer) {
109 		wpa_printf(MSG_DEBUG, "RSN: Sending EAPOL-Key SMK Error (peer "
110 			   MACSTR " mui %d error_type %d)",
111 			   MAC2STR(peer), mui, error_type);
112 	} else {
113 		wpa_printf(MSG_DEBUG, "RSN: Sending EAPOL-Key SMK Error "
114 			   "(mui %d error_type %d)", mui, error_type);
115 	}
116 
117 	wpa_eapol_key_send(sm, sm->ptk.kck, sm->ptk.kck_len, ver, dst,
118 			   ETH_P_EAPOL, rbuf, rlen, err192->key_mic);
119 
120 	return 0;
121 }
122 
123 
wpa_supplicant_send_smk_m3(struct wpa_sm * sm,const unsigned char * src_addr,const struct wpa_eapol_key * key,int ver,struct wpa_peerkey * peerkey)124 static int wpa_supplicant_send_smk_m3(struct wpa_sm *sm,
125 				      const unsigned char *src_addr,
126 				      const struct wpa_eapol_key *key,
127 				      int ver, struct wpa_peerkey *peerkey)
128 {
129 	size_t rlen;
130 	struct wpa_eapol_key *reply;
131 	struct wpa_eapol_key_192 *reply192;
132 	u8 *rbuf, *pos;
133 	size_t kde_len;
134 	u16 key_info;
135 
136 	/* KDEs: Peer RSN IE, Initiator MAC Address, Initiator Nonce */
137 	kde_len = peerkey->rsnie_p_len +
138 		2 + RSN_SELECTOR_LEN + ETH_ALEN +
139 		2 + RSN_SELECTOR_LEN + WPA_NONCE_LEN;
140 
141 	rbuf = wpa_sm_alloc_eapol(sm, IEEE802_1X_TYPE_EAPOL_KEY,
142 				  NULL, sizeof(*reply) + kde_len, &rlen,
143 				  (void *) &reply);
144 	if (rbuf == NULL)
145 		return -1;
146 	reply192 = (struct wpa_eapol_key_192 *) reply;
147 
148 	reply->type = EAPOL_KEY_TYPE_RSN;
149 	key_info = ver | WPA_KEY_INFO_SMK_MESSAGE | WPA_KEY_INFO_MIC |
150 		WPA_KEY_INFO_SECURE;
151 	WPA_PUT_BE16(reply->key_info, key_info);
152 	WPA_PUT_BE16(reply->key_length, 0);
153 	os_memcpy(reply->replay_counter, key->replay_counter,
154 		  WPA_REPLAY_COUNTER_LEN);
155 
156 	os_memcpy(reply->key_nonce, peerkey->pnonce, WPA_NONCE_LEN);
157 
158 	WPA_PUT_BE16(reply->key_data_length, (u16) kde_len);
159 	pos = (u8 *) (reply + 1);
160 
161 	/* Peer RSN IE */
162 	pos = wpa_add_ie(pos, peerkey->rsnie_p, peerkey->rsnie_p_len);
163 
164 	/* Initiator MAC Address KDE */
165 	pos = wpa_add_kde(pos, RSN_KEY_DATA_MAC_ADDR, peerkey->addr, ETH_ALEN);
166 
167 	/* Initiator Nonce */
168 	wpa_add_kde(pos, RSN_KEY_DATA_NONCE, peerkey->inonce, WPA_NONCE_LEN);
169 
170 	wpa_printf(MSG_DEBUG, "RSN: Sending EAPOL-Key SMK M3");
171 	wpa_eapol_key_send(sm, sm->ptk.kck, sm->ptk.kck_len, ver, src_addr,
172 			   ETH_P_EAPOL, rbuf, rlen, reply192->key_mic);
173 
174 	return 0;
175 }
176 
177 
wpa_supplicant_process_smk_m2(struct wpa_sm * sm,const unsigned char * src_addr,const struct wpa_eapol_key * key,size_t extra_len,int ver)178 static int wpa_supplicant_process_smk_m2(
179 	struct wpa_sm *sm, const unsigned char *src_addr,
180 	const struct wpa_eapol_key *key, size_t extra_len, int ver)
181 {
182 	struct wpa_peerkey *peerkey;
183 	struct wpa_eapol_ie_parse kde;
184 	struct wpa_ie_data ie;
185 	int cipher;
186 	struct rsn_ie_hdr *hdr;
187 	u8 *pos;
188 
189 	wpa_printf(MSG_DEBUG, "RSN: Received SMK M2");
190 
191 	if (!sm->peerkey_enabled || sm->proto != WPA_PROTO_RSN) {
192 		wpa_printf(MSG_INFO, "RSN: SMK handshake not allowed for "
193 			   "the current network");
194 		return -1;
195 	}
196 
197 	if (wpa_supplicant_parse_ies((const u8 *) (key + 1), extra_len, &kde) <
198 	    0) {
199 		wpa_printf(MSG_INFO, "RSN: Failed to parse KDEs in SMK M2");
200 		return -1;
201 	}
202 
203 	if (kde.rsn_ie == NULL || kde.mac_addr == NULL ||
204 	    kde.mac_addr_len < ETH_ALEN) {
205 		wpa_printf(MSG_INFO, "RSN: No RSN IE or MAC address KDE in "
206 			   "SMK M2");
207 		return -1;
208 	}
209 
210 	wpa_printf(MSG_DEBUG, "RSN: SMK M2 - SMK initiator " MACSTR,
211 		   MAC2STR(kde.mac_addr));
212 
213 	if (kde.rsn_ie_len > PEERKEY_MAX_IE_LEN) {
214 		wpa_printf(MSG_INFO, "RSN: Too long Initiator RSN IE in SMK "
215 			   "M2");
216 		return -1;
217 	}
218 
219 	if (wpa_parse_wpa_ie_rsn(kde.rsn_ie, kde.rsn_ie_len, &ie) < 0) {
220 		wpa_printf(MSG_INFO, "RSN: Failed to parse RSN IE in SMK M2");
221 		return -1;
222 	}
223 
224 	cipher = wpa_pick_pairwise_cipher(ie.pairwise_cipher &
225 					  sm->allowed_pairwise_cipher, 0);
226 	if (cipher < 0) {
227 		wpa_printf(MSG_INFO, "RSN: No acceptable cipher in SMK M2");
228 		wpa_supplicant_send_smk_error(sm, src_addr, kde.mac_addr,
229 					      STK_MUI_SMK, STK_ERR_CPHR_NS,
230 					      ver);
231 		return -1;
232 	}
233 	wpa_printf(MSG_DEBUG, "RSN: Using %s for PeerKey",
234 		   wpa_cipher_txt(cipher));
235 
236 	/* TODO: find existing entry and if found, use that instead of adding
237 	 * a new one; how to handle the case where both ends initiate at the
238 	 * same time? */
239 	peerkey = os_zalloc(sizeof(*peerkey));
240 	if (peerkey == NULL)
241 		return -1;
242 	os_memcpy(peerkey->addr, kde.mac_addr, ETH_ALEN);
243 	os_memcpy(peerkey->inonce, key->key_nonce, WPA_NONCE_LEN);
244 	os_memcpy(peerkey->rsnie_i, kde.rsn_ie, kde.rsn_ie_len);
245 	peerkey->rsnie_i_len = kde.rsn_ie_len;
246 	peerkey->cipher = cipher;
247 	peerkey->akmp = ie.key_mgmt;
248 
249 	if (random_get_bytes(peerkey->pnonce, WPA_NONCE_LEN)) {
250 		wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
251 			"WPA: Failed to get random data for PNonce");
252 		wpa_supplicant_peerkey_free(sm, peerkey);
253 		return -1;
254 	}
255 
256 	hdr = (struct rsn_ie_hdr *) peerkey->rsnie_p;
257 	hdr->elem_id = WLAN_EID_RSN;
258 	WPA_PUT_LE16(hdr->version, RSN_VERSION);
259 	pos = (u8 *) (hdr + 1);
260 	/* Group Suite can be anything for SMK RSN IE; receiver will just
261 	 * ignore it. */
262 	RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
263 	pos += RSN_SELECTOR_LEN;
264 	/* Include only the selected cipher in pairwise cipher suite */
265 	WPA_PUT_LE16(pos, 1);
266 	pos += 2;
267 	RSN_SELECTOR_PUT(pos, wpa_cipher_to_suite(WPA_PROTO_RSN, cipher));
268 	pos += RSN_SELECTOR_LEN;
269 
270 	hdr->len = (pos - peerkey->rsnie_p) - 2;
271 	peerkey->rsnie_p_len = pos - peerkey->rsnie_p;
272 	wpa_hexdump(MSG_DEBUG, "WPA: RSN IE for SMK handshake",
273 		    peerkey->rsnie_p, peerkey->rsnie_p_len);
274 
275 	wpa_supplicant_send_smk_m3(sm, src_addr, key, ver, peerkey);
276 
277 	peerkey->next = sm->peerkey;
278 	sm->peerkey = peerkey;
279 
280 	return 0;
281 }
282 
283 
284 /**
285  * rsn_smkid - Derive SMK identifier
286  * @smk: Station master key (32 bytes)
287  * @pnonce: Peer Nonce
288  * @mac_p: Peer MAC address
289  * @inonce: Initiator Nonce
290  * @mac_i: Initiator MAC address
291  * @akmp: Negotiated AKM
292  *
293  * 8.5.1.4 Station to station (STK) key hierarchy
294  * SMKID = HMAC-SHA1-128(SMK, "SMK Name" || PNonce || MAC_P || INonce || MAC_I)
295  */
rsn_smkid(const u8 * smk,const u8 * pnonce,const u8 * mac_p,const u8 * inonce,const u8 * mac_i,u8 * smkid,int akmp)296 static void rsn_smkid(const u8 *smk, const u8 *pnonce, const u8 *mac_p,
297 		      const u8 *inonce, const u8 *mac_i, u8 *smkid,
298 		      int akmp)
299 {
300 	char *title = "SMK Name";
301 	const u8 *addr[5];
302 	const size_t len[5] = { 8, WPA_NONCE_LEN, ETH_ALEN, WPA_NONCE_LEN,
303 				ETH_ALEN };
304 	unsigned char hash[SHA256_MAC_LEN];
305 
306 	addr[0] = (u8 *) title;
307 	addr[1] = pnonce;
308 	addr[2] = mac_p;
309 	addr[3] = inonce;
310 	addr[4] = mac_i;
311 
312 #ifdef CONFIG_IEEE80211W
313 	if (wpa_key_mgmt_sha256(akmp))
314 		hmac_sha256_vector(smk, PMK_LEN, 5, addr, len, hash);
315 	else
316 #endif /* CONFIG_IEEE80211W */
317 		hmac_sha1_vector(smk, PMK_LEN, 5, addr, len, hash);
318 	os_memcpy(smkid, hash, PMKID_LEN);
319 }
320 
321 
wpa_supplicant_send_stk_1_of_4(struct wpa_sm * sm,struct wpa_peerkey * peerkey)322 static void wpa_supplicant_send_stk_1_of_4(struct wpa_sm *sm,
323 					   struct wpa_peerkey *peerkey)
324 {
325 	size_t mlen;
326 	struct wpa_eapol_key *msg;
327 	u8 *mbuf;
328 	size_t kde_len;
329 	u16 key_info, ver;
330 
331 	kde_len = 2 + RSN_SELECTOR_LEN + PMKID_LEN;
332 
333 	mbuf = wpa_sm_alloc_eapol(sm, IEEE802_1X_TYPE_EAPOL_KEY, NULL,
334 				  sizeof(*msg) + kde_len, &mlen,
335 				  (void *) &msg);
336 	if (mbuf == NULL)
337 		return;
338 
339 	msg->type = EAPOL_KEY_TYPE_RSN;
340 
341 	if (peerkey->cipher != WPA_CIPHER_TKIP)
342 		ver = WPA_KEY_INFO_TYPE_HMAC_SHA1_AES;
343 	else
344 		ver = WPA_KEY_INFO_TYPE_HMAC_MD5_RC4;
345 
346 	key_info = ver | WPA_KEY_INFO_KEY_TYPE | WPA_KEY_INFO_ACK;
347 	WPA_PUT_BE16(msg->key_info, key_info);
348 
349 	if (peerkey->cipher != WPA_CIPHER_TKIP)
350 		WPA_PUT_BE16(msg->key_length, 16);
351 	else
352 		WPA_PUT_BE16(msg->key_length, 32);
353 
354 	os_memcpy(msg->replay_counter, peerkey->replay_counter,
355 		  WPA_REPLAY_COUNTER_LEN);
356 	inc_byte_array(peerkey->replay_counter, WPA_REPLAY_COUNTER_LEN);
357 
358 	WPA_PUT_BE16(msg->key_data_length, kde_len);
359 	wpa_add_kde((u8 *) (msg + 1), RSN_KEY_DATA_PMKID,
360 		    peerkey->smkid, PMKID_LEN);
361 
362 	if (random_get_bytes(peerkey->inonce, WPA_NONCE_LEN)) {
363 		wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
364 			"RSN: Failed to get random data for INonce (STK)");
365 		os_free(mbuf);
366 		return;
367 	}
368 	wpa_hexdump(MSG_DEBUG, "RSN: INonce for STK 4-Way Handshake",
369 		    peerkey->inonce, WPA_NONCE_LEN);
370 	os_memcpy(msg->key_nonce, peerkey->inonce, WPA_NONCE_LEN);
371 
372 	wpa_printf(MSG_DEBUG, "RSN: Sending EAPOL-Key STK 1/4 to " MACSTR,
373 		   MAC2STR(peerkey->addr));
374 	wpa_eapol_key_send(sm, NULL, 0, ver, peerkey->addr, ETH_P_EAPOL,
375 			   mbuf, mlen, NULL);
376 }
377 
378 
wpa_supplicant_send_stk_3_of_4(struct wpa_sm * sm,struct wpa_peerkey * peerkey)379 static void wpa_supplicant_send_stk_3_of_4(struct wpa_sm *sm,
380 					   struct wpa_peerkey *peerkey)
381 {
382 	size_t mlen;
383 	struct wpa_eapol_key *msg;
384 	u8 *mbuf, *pos;
385 	size_t kde_len;
386 	u16 key_info, ver;
387 	be32 lifetime;
388 
389 	kde_len = peerkey->rsnie_i_len +
390 		2 + RSN_SELECTOR_LEN + sizeof(lifetime);
391 
392 	mbuf = wpa_sm_alloc_eapol(sm, IEEE802_1X_TYPE_EAPOL_KEY, NULL,
393 				  sizeof(*msg) + kde_len, &mlen,
394 				  (void *) &msg);
395 	if (mbuf == NULL)
396 		return;
397 
398 	msg->type = EAPOL_KEY_TYPE_RSN;
399 
400 	if (peerkey->cipher != WPA_CIPHER_TKIP)
401 		ver = WPA_KEY_INFO_TYPE_HMAC_SHA1_AES;
402 	else
403 		ver = WPA_KEY_INFO_TYPE_HMAC_MD5_RC4;
404 
405 	key_info = ver | WPA_KEY_INFO_KEY_TYPE | WPA_KEY_INFO_ACK |
406 		WPA_KEY_INFO_MIC | WPA_KEY_INFO_SECURE;
407 	WPA_PUT_BE16(msg->key_info, key_info);
408 
409 	if (peerkey->cipher != WPA_CIPHER_TKIP)
410 		WPA_PUT_BE16(msg->key_length, 16);
411 	else
412 		WPA_PUT_BE16(msg->key_length, 32);
413 
414 	os_memcpy(msg->replay_counter, peerkey->replay_counter,
415 		  WPA_REPLAY_COUNTER_LEN);
416 	inc_byte_array(peerkey->replay_counter, WPA_REPLAY_COUNTER_LEN);
417 
418 	WPA_PUT_BE16(msg->key_data_length, kde_len);
419 	pos = (u8 *) (msg + 1);
420 	pos = wpa_add_ie(pos, peerkey->rsnie_i, peerkey->rsnie_i_len);
421 	lifetime = host_to_be32(peerkey->lifetime);
422 	wpa_add_kde(pos, RSN_KEY_DATA_LIFETIME,
423 		    (u8 *) &lifetime, sizeof(lifetime));
424 
425 	os_memcpy(msg->key_nonce, peerkey->inonce, WPA_NONCE_LEN);
426 
427 	wpa_printf(MSG_DEBUG, "RSN: Sending EAPOL-Key STK 3/4 to " MACSTR,
428 		   MAC2STR(peerkey->addr));
429 	wpa_eapol_key_send(sm, peerkey->stk.kck, peerkey->stk.kck_len, ver,
430 			   peerkey->addr, ETH_P_EAPOL, mbuf, mlen,
431 			   msg->key_mic);
432 }
433 
434 
wpa_supplicant_process_smk_m4(struct wpa_peerkey * peerkey,struct wpa_eapol_ie_parse * kde)435 static int wpa_supplicant_process_smk_m4(struct wpa_peerkey *peerkey,
436 					 struct wpa_eapol_ie_parse *kde)
437 {
438 	wpa_printf(MSG_DEBUG, "RSN: Received SMK M4 (Initiator " MACSTR ")",
439 		   MAC2STR(kde->mac_addr));
440 
441 	if (os_memcmp(kde->smk + PMK_LEN, peerkey->pnonce, WPA_NONCE_LEN) != 0)
442 	{
443 		wpa_printf(MSG_INFO, "RSN: PNonce in SMK KDE does not "
444 			   "match with the one used in SMK M3");
445 		return -1;
446 	}
447 
448 	if (os_memcmp(kde->nonce, peerkey->inonce, WPA_NONCE_LEN) != 0) {
449 		wpa_printf(MSG_INFO, "RSN: INonce in SMK M4 did not "
450 			   "match with the one received in SMK M2");
451 		return -1;
452 	}
453 
454 	return 0;
455 }
456 
457 
wpa_supplicant_process_smk_m5(struct wpa_sm * sm,const unsigned char * src_addr,const struct wpa_eapol_key * key,int ver,struct wpa_peerkey * peerkey,struct wpa_eapol_ie_parse * kde)458 static int wpa_supplicant_process_smk_m5(struct wpa_sm *sm,
459 					 const unsigned char *src_addr,
460 					 const struct wpa_eapol_key *key,
461 					 int ver,
462 					 struct wpa_peerkey *peerkey,
463 					 struct wpa_eapol_ie_parse *kde)
464 {
465 	int cipher;
466 	struct wpa_ie_data ie;
467 
468 	wpa_printf(MSG_DEBUG, "RSN: Received SMK M5 (Peer " MACSTR ")",
469 		   MAC2STR(kde->mac_addr));
470 	if (kde->rsn_ie == NULL || kde->rsn_ie_len > PEERKEY_MAX_IE_LEN ||
471 	    wpa_parse_wpa_ie_rsn(kde->rsn_ie, kde->rsn_ie_len, &ie) < 0) {
472 		wpa_printf(MSG_INFO, "RSN: No RSN IE in SMK M5");
473 		/* TODO: abort negotiation */
474 		return -1;
475 	}
476 
477 	if (os_memcmp(key->key_nonce, peerkey->inonce, WPA_NONCE_LEN) != 0) {
478 		wpa_printf(MSG_INFO, "RSN: Key Nonce in SMK M5 does "
479 			   "not match with INonce used in SMK M1");
480 		return -1;
481 	}
482 
483 	if (os_memcmp(kde->smk + PMK_LEN, peerkey->inonce, WPA_NONCE_LEN) != 0)
484 	{
485 		wpa_printf(MSG_INFO, "RSN: INonce in SMK KDE does not "
486 			   "match with the one used in SMK M1");
487 		return -1;
488 	}
489 
490 	os_memcpy(peerkey->rsnie_p, kde->rsn_ie, kde->rsn_ie_len);
491 	peerkey->rsnie_p_len = kde->rsn_ie_len;
492 	os_memcpy(peerkey->pnonce, kde->nonce, WPA_NONCE_LEN);
493 
494 	cipher = wpa_pick_pairwise_cipher(ie.pairwise_cipher &
495 					  sm->allowed_pairwise_cipher, 0);
496 	if (cipher < 0) {
497 		wpa_printf(MSG_INFO, "RSN: SMK Peer STA " MACSTR " selected "
498 			   "unacceptable cipher", MAC2STR(kde->mac_addr));
499 		wpa_supplicant_send_smk_error(sm, src_addr, kde->mac_addr,
500 					      STK_MUI_SMK, STK_ERR_CPHR_NS,
501 					      ver);
502 		/* TODO: abort negotiation */
503 		return -1;
504 	}
505 	wpa_printf(MSG_DEBUG, "RSN: Using %s for PeerKey",
506 		   wpa_cipher_txt(cipher));
507 	peerkey->cipher = cipher;
508 
509 	return 0;
510 }
511 
512 
wpa_supplicant_process_smk_m45(struct wpa_sm * sm,const unsigned char * src_addr,const struct wpa_eapol_key * key,size_t extra_len,int ver)513 static int wpa_supplicant_process_smk_m45(
514 	struct wpa_sm *sm, const unsigned char *src_addr,
515 	const struct wpa_eapol_key *key, size_t extra_len, int ver)
516 {
517 	struct wpa_peerkey *peerkey;
518 	struct wpa_eapol_ie_parse kde;
519 	u32 lifetime;
520 
521 	if (!sm->peerkey_enabled || sm->proto != WPA_PROTO_RSN) {
522 		wpa_printf(MSG_DEBUG, "RSN: SMK handshake not allowed for "
523 			   "the current network");
524 		return -1;
525 	}
526 
527 	if (wpa_supplicant_parse_ies((const u8 *) (key + 1), extra_len, &kde) <
528 	    0) {
529 		wpa_printf(MSG_INFO, "RSN: Failed to parse KDEs in SMK M4/M5");
530 		return -1;
531 	}
532 
533 	if (kde.mac_addr == NULL || kde.mac_addr_len < ETH_ALEN ||
534 	    kde.nonce == NULL || kde.nonce_len < WPA_NONCE_LEN ||
535 	    kde.smk == NULL || kde.smk_len < PMK_LEN + WPA_NONCE_LEN ||
536 	    kde.lifetime == NULL || kde.lifetime_len < 4) {
537 		wpa_printf(MSG_INFO, "RSN: No MAC Address, Nonce, SMK, or "
538 			   "Lifetime KDE in SMK M4/M5");
539 		return -1;
540 	}
541 
542 	for (peerkey = sm->peerkey; peerkey; peerkey = peerkey->next) {
543 		if (os_memcmp(peerkey->addr, kde.mac_addr, ETH_ALEN) == 0 &&
544 		    os_memcmp(peerkey->initiator ? peerkey->inonce :
545 			   peerkey->pnonce,
546 			   key->key_nonce, WPA_NONCE_LEN) == 0)
547 			break;
548 	}
549 	if (peerkey == NULL) {
550 		wpa_printf(MSG_INFO, "RSN: No matching SMK handshake found "
551 			   "for SMK M4/M5: peer " MACSTR,
552 			   MAC2STR(kde.mac_addr));
553 		return -1;
554 	}
555 
556 	if (peerkey->initiator) {
557 		if (wpa_supplicant_process_smk_m5(sm, src_addr, key, ver,
558 						  peerkey, &kde) < 0)
559 			return -1;
560 	} else {
561 		if (wpa_supplicant_process_smk_m4(peerkey, &kde) < 0)
562 			return -1;
563 	}
564 
565 	os_memcpy(peerkey->smk, kde.smk, PMK_LEN);
566 	peerkey->smk_complete = 1;
567 	wpa_hexdump_key(MSG_DEBUG, "RSN: SMK", peerkey->smk, PMK_LEN);
568 	lifetime = WPA_GET_BE32(kde.lifetime);
569 	wpa_printf(MSG_DEBUG, "RSN: SMK lifetime %u seconds", lifetime);
570 	if (lifetime > 1000000000)
571 		lifetime = 1000000000; /* avoid overflowing eloop time */
572 	peerkey->lifetime = lifetime;
573 	eloop_register_timeout(lifetime, 0, wpa_supplicant_smk_timeout,
574 			       sm, peerkey);
575 
576 	if (peerkey->initiator) {
577 		rsn_smkid(peerkey->smk, peerkey->pnonce, peerkey->addr,
578 			  peerkey->inonce, sm->own_addr, peerkey->smkid,
579 			  peerkey->akmp);
580 		wpa_supplicant_send_stk_1_of_4(sm, peerkey);
581 	} else {
582 		rsn_smkid(peerkey->smk, peerkey->pnonce, sm->own_addr,
583 			  peerkey->inonce, peerkey->addr, peerkey->smkid,
584 			  peerkey->akmp);
585 	}
586 	wpa_hexdump(MSG_DEBUG, "RSN: SMKID", peerkey->smkid, PMKID_LEN);
587 
588 	return 0;
589 }
590 
591 
wpa_supplicant_process_smk_error(struct wpa_sm * sm,const unsigned char * src_addr,const struct wpa_eapol_key * key,size_t extra_len)592 static int wpa_supplicant_process_smk_error(
593 	struct wpa_sm *sm, const unsigned char *src_addr,
594 	const struct wpa_eapol_key *key, size_t extra_len)
595 {
596 	struct wpa_eapol_ie_parse kde;
597 	struct rsn_error_kde error;
598 	u8 peer[ETH_ALEN];
599 	u16 error_type;
600 
601 	wpa_printf(MSG_DEBUG, "RSN: Received SMK Error");
602 
603 	if (!sm->peerkey_enabled || sm->proto != WPA_PROTO_RSN) {
604 		wpa_printf(MSG_DEBUG, "RSN: SMK handshake not allowed for "
605 			   "the current network");
606 		return -1;
607 	}
608 
609 	if (wpa_supplicant_parse_ies((const u8 *) (key + 1), extra_len, &kde) <
610 	    0) {
611 		wpa_printf(MSG_INFO, "RSN: Failed to parse KDEs in SMK Error");
612 		return -1;
613 	}
614 
615 	if (kde.error == NULL || kde.error_len < sizeof(error)) {
616 		wpa_printf(MSG_INFO, "RSN: No Error KDE in SMK Error");
617 		return -1;
618 	}
619 
620 	if (kde.mac_addr && kde.mac_addr_len >= ETH_ALEN)
621 		os_memcpy(peer, kde.mac_addr, ETH_ALEN);
622 	else
623 		os_memset(peer, 0, ETH_ALEN);
624 	os_memcpy(&error, kde.error, sizeof(error));
625 	error_type = be_to_host16(error.error_type);
626 	wpa_msg(sm->ctx->msg_ctx, MSG_INFO,
627 		"RSN: SMK Error KDE received: MUI %d error_type %d peer "
628 		MACSTR,
629 		be_to_host16(error.mui), error_type,
630 		MAC2STR(peer));
631 
632 	if (kde.mac_addr &&
633 	    (error_type == STK_ERR_STA_NR || error_type == STK_ERR_STA_NRSN ||
634 	     error_type == STK_ERR_CPHR_NS)) {
635 		struct wpa_peerkey *peerkey;
636 
637 		for (peerkey = sm->peerkey; peerkey; peerkey = peerkey->next) {
638 			if (os_memcmp(peerkey->addr, kde.mac_addr, ETH_ALEN) ==
639 			    0)
640 				break;
641 		}
642 		if (peerkey == NULL) {
643 			wpa_printf(MSG_DEBUG, "RSN: No matching SMK handshake "
644 				   "found for SMK Error");
645 			return -1;
646 		}
647 		/* TODO: abort SMK/STK handshake and remove all related keys */
648 	}
649 
650 	return 0;
651 }
652 
653 
wpa_supplicant_process_stk_1_of_4(struct wpa_sm * sm,struct wpa_peerkey * peerkey,const struct wpa_eapol_key * key,u16 ver,const u8 * key_data,size_t key_data_len)654 static void wpa_supplicant_process_stk_1_of_4(struct wpa_sm *sm,
655 					      struct wpa_peerkey *peerkey,
656 					      const struct wpa_eapol_key *key,
657 					      u16 ver, const u8 *key_data,
658 					      size_t key_data_len)
659 {
660 	struct wpa_eapol_ie_parse ie;
661 	size_t kde_buf_len;
662 	struct wpa_ptk *stk;
663 	u8 buf[8], *kde_buf, *pos;
664 	be32 lifetime;
665 
666 	wpa_printf(MSG_DEBUG, "RSN: RX message 1 of STK 4-Way Handshake from "
667 		   MACSTR " (ver=%d)", MAC2STR(peerkey->addr), ver);
668 
669 	os_memset(&ie, 0, sizeof(ie));
670 
671 	/* RSN: msg 1/4 should contain SMKID for the selected SMK */
672 	wpa_hexdump(MSG_DEBUG, "RSN: msg 1/4 key data", key_data, key_data_len);
673 	if (wpa_supplicant_parse_ies(key_data, key_data_len, &ie) < 0 ||
674 	    ie.pmkid == NULL) {
675 		wpa_printf(MSG_DEBUG, "RSN: No SMKID in STK 1/4");
676 		return;
677 	}
678 	if (os_memcmp_const(ie.pmkid, peerkey->smkid, PMKID_LEN) != 0) {
679 		wpa_hexdump(MSG_DEBUG, "RSN: Unknown SMKID in STK 1/4",
680 			    ie.pmkid, PMKID_LEN);
681 		return;
682 	}
683 
684 	if (random_get_bytes(peerkey->pnonce, WPA_NONCE_LEN)) {
685 		wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
686 			"RSN: Failed to get random data for PNonce");
687 		return;
688 	}
689 	wpa_hexdump(MSG_DEBUG, "WPA: Renewed PNonce",
690 		    peerkey->pnonce, WPA_NONCE_LEN);
691 
692 	/* Calculate STK which will be stored as a temporary STK until it has
693 	 * been verified when processing message 3/4. */
694 	stk = &peerkey->tstk;
695 	wpa_pmk_to_ptk(peerkey->smk, PMK_LEN, "Peer key expansion",
696 		       sm->own_addr, peerkey->addr,
697 		       peerkey->pnonce, key->key_nonce,
698 		       stk, peerkey->akmp, peerkey->cipher);
699 	/* Supplicant: swap tx/rx Mic keys */
700 	os_memcpy(buf, &stk->tk[16], 8);
701 	os_memcpy(&stk->tk[16], &stk->tk[24], 8);
702 	os_memcpy(&stk->tk[24], buf, 8);
703 	peerkey->tstk_set = 1;
704 
705 	kde_buf_len = peerkey->rsnie_p_len +
706 		2 + RSN_SELECTOR_LEN + sizeof(lifetime) +
707 		2 + RSN_SELECTOR_LEN + PMKID_LEN;
708 	kde_buf = os_malloc(kde_buf_len);
709 	if (kde_buf == NULL)
710 		return;
711 	pos = kde_buf;
712 	pos = wpa_add_ie(pos, peerkey->rsnie_p, peerkey->rsnie_p_len);
713 	lifetime = host_to_be32(peerkey->lifetime);
714 	pos = wpa_add_kde(pos, RSN_KEY_DATA_LIFETIME,
715 			  (u8 *) &lifetime, sizeof(lifetime));
716 	wpa_add_kde(pos, RSN_KEY_DATA_PMKID, peerkey->smkid, PMKID_LEN);
717 
718 	if (wpa_supplicant_send_2_of_4(sm, peerkey->addr, key, ver,
719 				       peerkey->pnonce, kde_buf, kde_buf_len,
720 				       stk)) {
721 		os_free(kde_buf);
722 		return;
723 	}
724 	os_free(kde_buf);
725 
726 	os_memcpy(peerkey->inonce, key->key_nonce, WPA_NONCE_LEN);
727 }
728 
729 
wpa_supplicant_update_smk_lifetime(struct wpa_sm * sm,struct wpa_peerkey * peerkey,struct wpa_eapol_ie_parse * kde)730 static void wpa_supplicant_update_smk_lifetime(struct wpa_sm *sm,
731 					       struct wpa_peerkey *peerkey,
732 					       struct wpa_eapol_ie_parse *kde)
733 {
734 	u32 lifetime;
735 
736 	if (kde->lifetime == NULL || kde->lifetime_len < sizeof(lifetime))
737 		return;
738 
739 	lifetime = WPA_GET_BE32(kde->lifetime);
740 
741 	if (lifetime >= peerkey->lifetime) {
742 		wpa_printf(MSG_DEBUG, "RSN: Peer used SMK lifetime %u seconds "
743 			   "which is larger than or equal to own value %u "
744 			   "seconds - ignored", lifetime, peerkey->lifetime);
745 		return;
746 	}
747 
748 	wpa_printf(MSG_DEBUG, "RSN: Peer used shorter SMK lifetime %u seconds "
749 		   "(own was %u seconds) - updated",
750 		   lifetime, peerkey->lifetime);
751 	peerkey->lifetime = lifetime;
752 
753 	eloop_cancel_timeout(wpa_supplicant_smk_timeout, sm, peerkey);
754 	eloop_register_timeout(lifetime, 0, wpa_supplicant_smk_timeout,
755 			       sm, peerkey);
756 }
757 
758 
wpa_supplicant_process_stk_2_of_4(struct wpa_sm * sm,struct wpa_peerkey * peerkey,const struct wpa_eapol_key * key,u16 ver,const u8 * key_data,size_t key_data_len)759 static void wpa_supplicant_process_stk_2_of_4(struct wpa_sm *sm,
760 					      struct wpa_peerkey *peerkey,
761 					      const struct wpa_eapol_key *key,
762 					      u16 ver, const u8 *key_data,
763 					      size_t key_data_len)
764 {
765 	struct wpa_eapol_ie_parse kde;
766 
767 	wpa_printf(MSG_DEBUG, "RSN: RX message 2 of STK 4-Way Handshake from "
768 		   MACSTR " (ver=%d)", MAC2STR(peerkey->addr), ver);
769 
770 	os_memset(&kde, 0, sizeof(kde));
771 
772 	/* RSN: msg 2/4 should contain SMKID for the selected SMK and RSN IE
773 	 * from the peer. It may also include Lifetime KDE. */
774 	wpa_hexdump(MSG_DEBUG, "RSN: msg 2/4 key data", key_data, key_data_len);
775 	if (wpa_supplicant_parse_ies(key_data, key_data_len, &kde) < 0 ||
776 	    kde.pmkid == NULL || kde.rsn_ie == NULL) {
777 		wpa_printf(MSG_DEBUG, "RSN: No SMKID or RSN IE in STK 2/4");
778 		return;
779 	}
780 
781 	if (os_memcmp_const(kde.pmkid, peerkey->smkid, PMKID_LEN) != 0) {
782 		wpa_hexdump(MSG_DEBUG, "RSN: Unknown SMKID in STK 2/4",
783 			    kde.pmkid, PMKID_LEN);
784 		return;
785 	}
786 
787 	if (kde.rsn_ie_len != peerkey->rsnie_p_len ||
788 	    os_memcmp(kde.rsn_ie, peerkey->rsnie_p, kde.rsn_ie_len) != 0) {
789 		wpa_printf(MSG_INFO, "RSN: Peer RSN IE in SMK and STK "
790 			   "handshakes did not match");
791 		wpa_hexdump(MSG_DEBUG, "RSN: Peer RSN IE in SMK handshake",
792 			    peerkey->rsnie_p, peerkey->rsnie_p_len);
793 		wpa_hexdump(MSG_DEBUG, "RSN: Peer RSN IE in STK handshake",
794 			    kde.rsn_ie, kde.rsn_ie_len);
795 		return;
796 	}
797 
798 	wpa_supplicant_update_smk_lifetime(sm, peerkey, &kde);
799 
800 	wpa_supplicant_send_stk_3_of_4(sm, peerkey);
801 	os_memcpy(peerkey->pnonce, key->key_nonce, WPA_NONCE_LEN);
802 }
803 
804 
wpa_supplicant_process_stk_3_of_4(struct wpa_sm * sm,struct wpa_peerkey * peerkey,const struct wpa_eapol_key * key,u16 ver,const u8 * key_data,size_t key_data_len)805 static void wpa_supplicant_process_stk_3_of_4(struct wpa_sm *sm,
806 					      struct wpa_peerkey *peerkey,
807 					      const struct wpa_eapol_key *key,
808 					      u16 ver, const u8 *key_data,
809 					      size_t key_data_len)
810 {
811 	struct wpa_eapol_ie_parse kde;
812 	size_t key_len;
813 	const u8 *_key;
814 	u8 key_buf[32], rsc[6];
815 
816 	wpa_printf(MSG_DEBUG, "RSN: RX message 3 of STK 4-Way Handshake from "
817 		   MACSTR " (ver=%d)", MAC2STR(peerkey->addr), ver);
818 
819 	os_memset(&kde, 0, sizeof(kde));
820 
821 	/* RSN: msg 3/4 should contain Initiator RSN IE. It may also include
822 	 * Lifetime KDE. */
823 	wpa_hexdump(MSG_DEBUG, "RSN: msg 3/4 key data", key_data, key_data_len);
824 	if (wpa_supplicant_parse_ies(key_data, key_data_len, &kde) < 0) {
825 		wpa_printf(MSG_DEBUG, "RSN: Failed to parse key data in "
826 			   "STK 3/4");
827 		return;
828 	}
829 
830 	if (kde.rsn_ie_len != peerkey->rsnie_i_len ||
831 	    os_memcmp(kde.rsn_ie, peerkey->rsnie_i, kde.rsn_ie_len) != 0) {
832 		wpa_printf(MSG_INFO, "RSN: Initiator RSN IE in SMK and STK "
833 			   "handshakes did not match");
834 		wpa_hexdump(MSG_DEBUG, "RSN: Initiator RSN IE in SMK "
835 			    "handshake",
836 			    peerkey->rsnie_i, peerkey->rsnie_i_len);
837 		wpa_hexdump(MSG_DEBUG, "RSN: Initiator RSN IE in STK "
838 			    "handshake",
839 			    kde.rsn_ie, kde.rsn_ie_len);
840 		return;
841 	}
842 
843 	if (os_memcmp(peerkey->inonce, key->key_nonce, WPA_NONCE_LEN) != 0) {
844 		wpa_printf(MSG_WARNING, "RSN: INonce from message 1 of STK "
845 			   "4-Way Handshake differs from 3 of STK 4-Way "
846 			   "Handshake - drop packet (src=" MACSTR ")",
847 			   MAC2STR(peerkey->addr));
848 		return;
849 	}
850 
851 	wpa_supplicant_update_smk_lifetime(sm, peerkey, &kde);
852 
853 	if (wpa_supplicant_send_4_of_4(sm, peerkey->addr, key, ver,
854 				       WPA_GET_BE16(key->key_info),
855 				       &peerkey->stk))
856 		return;
857 
858 	_key = peerkey->stk.tk;
859 	if (peerkey->cipher == WPA_CIPHER_TKIP) {
860 		/* Swap Tx/Rx keys for Michael MIC */
861 		os_memcpy(key_buf, _key, 16);
862 		os_memcpy(key_buf + 16, _key + 24, 8);
863 		os_memcpy(key_buf + 24, _key + 16, 8);
864 		_key = key_buf;
865 		key_len = 32;
866 	} else
867 		key_len = 16;
868 
869 	os_memset(rsc, 0, 6);
870 	if (wpa_sm_set_key(sm, peerkey->cipher, peerkey->addr, 0, 1,
871 			   rsc, sizeof(rsc), _key, key_len) < 0) {
872 		os_memset(key_buf, 0, sizeof(key_buf));
873 		wpa_printf(MSG_WARNING, "RSN: Failed to set STK to the "
874 			   "driver.");
875 		return;
876 	}
877 	os_memset(key_buf, 0, sizeof(key_buf));
878 }
879 
880 
wpa_supplicant_process_stk_4_of_4(struct wpa_sm * sm,struct wpa_peerkey * peerkey,const struct wpa_eapol_key * key,u16 ver)881 static void wpa_supplicant_process_stk_4_of_4(struct wpa_sm *sm,
882 					      struct wpa_peerkey *peerkey,
883 					      const struct wpa_eapol_key *key,
884 					      u16 ver)
885 {
886 	u8 rsc[6];
887 
888 	wpa_printf(MSG_DEBUG, "RSN: RX message 4 of STK 4-Way Handshake from "
889 		   MACSTR " (ver=%d)", MAC2STR(peerkey->addr), ver);
890 
891 	os_memset(rsc, 0, 6);
892 	if (wpa_sm_set_key(sm, peerkey->cipher, peerkey->addr, 0, 1,
893 			   rsc, sizeof(rsc), peerkey->stk.tk,
894 			   peerkey->cipher == WPA_CIPHER_TKIP ? 32 : 16) < 0) {
895 		wpa_printf(MSG_WARNING, "RSN: Failed to set STK to the "
896 			   "driver.");
897 		return;
898 	}
899 }
900 
901 
902 /**
903  * peerkey_verify_eapol_key_mic - Verify PeerKey MIC
904  * @sm: Pointer to WPA state machine data from wpa_sm_init()
905  * @peerkey: Pointer to the PeerKey data for the peer
906  * @key: Pointer to the EAPOL-Key frame header
907  * @ver: Version bits from EAPOL-Key Key Info
908  * @buf: Pointer to the beginning of EAPOL-Key frame
909  * @len: Length of the EAPOL-Key frame
910  * Returns: 0 on success, -1 on failure
911  */
peerkey_verify_eapol_key_mic(struct wpa_sm * sm,struct wpa_peerkey * peerkey,struct wpa_eapol_key_192 * key,u16 ver,const u8 * buf,size_t len)912 int peerkey_verify_eapol_key_mic(struct wpa_sm *sm,
913 				 struct wpa_peerkey *peerkey,
914 				 struct wpa_eapol_key_192 *key, u16 ver,
915 				 const u8 *buf, size_t len)
916 {
917 	u8 mic[WPA_EAPOL_KEY_MIC_MAX_LEN];
918 	size_t mic_len = 16;
919 	int ok = 0;
920 
921 	if (peerkey->initiator && !peerkey->stk_set) {
922 		wpa_pmk_to_ptk(peerkey->smk, PMK_LEN, "Peer key expansion",
923 			       sm->own_addr, peerkey->addr,
924 			       peerkey->inonce, key->key_nonce,
925 			       &peerkey->stk, peerkey->akmp, peerkey->cipher);
926 		peerkey->stk_set = 1;
927 	}
928 
929 	os_memcpy(mic, key->key_mic, mic_len);
930 	if (peerkey->tstk_set) {
931 		os_memset(key->key_mic, 0, mic_len);
932 		wpa_eapol_key_mic(peerkey->tstk.kck, peerkey->tstk.kck_len,
933 				  sm->key_mgmt, ver, buf, len, key->key_mic);
934 		if (os_memcmp_const(mic, key->key_mic, mic_len) != 0) {
935 			wpa_printf(MSG_WARNING, "RSN: Invalid EAPOL-Key MIC "
936 				   "when using TSTK - ignoring TSTK");
937 		} else {
938 			ok = 1;
939 			peerkey->tstk_set = 0;
940 			peerkey->stk_set = 1;
941 			os_memcpy(&peerkey->stk, &peerkey->tstk,
942 				  sizeof(peerkey->stk));
943 			os_memset(&peerkey->tstk, 0, sizeof(peerkey->tstk));
944 		}
945 	}
946 
947 	if (!ok && peerkey->stk_set) {
948 		os_memset(key->key_mic, 0, mic_len);
949 		wpa_eapol_key_mic(peerkey->stk.kck, peerkey->stk.kck_len,
950 				  sm->key_mgmt, ver, buf, len, key->key_mic);
951 		if (os_memcmp_const(mic, key->key_mic, mic_len) != 0) {
952 			wpa_printf(MSG_WARNING, "RSN: Invalid EAPOL-Key MIC "
953 				   "- dropping packet");
954 			return -1;
955 		}
956 		ok = 1;
957 	}
958 
959 	if (!ok) {
960 		wpa_printf(MSG_WARNING, "RSN: Could not verify EAPOL-Key MIC "
961 			   "- dropping packet");
962 		return -1;
963 	}
964 
965 	os_memcpy(peerkey->replay_counter, key->replay_counter,
966 		  WPA_REPLAY_COUNTER_LEN);
967 	peerkey->replay_counter_set = 1;
968 	return 0;
969 }
970 
971 
972 /**
973  * wpa_sm_stkstart - Send EAPOL-Key Request for STK handshake (STK M1)
974  * @sm: Pointer to WPA state machine data from wpa_sm_init()
975  * @peer: MAC address of the peer STA
976  * Returns: 0 on success, or -1 on failure
977  *
978  * Send an EAPOL-Key Request to the current authenticator to start STK
979  * handshake with the peer.
980  */
wpa_sm_stkstart(struct wpa_sm * sm,const u8 * peer)981 int wpa_sm_stkstart(struct wpa_sm *sm, const u8 *peer)
982 {
983 	size_t rlen, kde_len;
984 	struct wpa_eapol_key *req;
985 	int key_info, ver;
986 	u8 bssid[ETH_ALEN], *rbuf, *pos, *count_pos;
987 	u16 count;
988 	struct rsn_ie_hdr *hdr;
989 	struct wpa_peerkey *peerkey;
990 	struct wpa_ie_data ie;
991 
992 	if (sm->proto != WPA_PROTO_RSN || !sm->ptk_set || !sm->peerkey_enabled)
993 		return -1;
994 
995 	if (sm->ap_rsn_ie &&
996 	    wpa_parse_wpa_ie_rsn(sm->ap_rsn_ie, sm->ap_rsn_ie_len, &ie) == 0 &&
997 	    !(ie.capabilities & WPA_CAPABILITY_PEERKEY_ENABLED)) {
998 		wpa_printf(MSG_DEBUG, "RSN: Current AP does not support STK");
999 		return -1;
1000 	}
1001 
1002 	if (sm->pairwise_cipher != WPA_CIPHER_TKIP)
1003 		ver = WPA_KEY_INFO_TYPE_HMAC_SHA1_AES;
1004 	else
1005 		ver = WPA_KEY_INFO_TYPE_HMAC_MD5_RC4;
1006 
1007 	if (wpa_sm_get_bssid(sm, bssid) < 0) {
1008 		wpa_printf(MSG_WARNING, "Failed to read BSSID for EAPOL-Key "
1009 			   "SMK M1");
1010 		return -1;
1011 	}
1012 
1013 	/* TODO: find existing entry and if found, use that instead of adding
1014 	 * a new one */
1015 	peerkey = os_zalloc(sizeof(*peerkey));
1016 	if (peerkey == NULL)
1017 		return -1;
1018 	peerkey->initiator = 1;
1019 	os_memcpy(peerkey->addr, peer, ETH_ALEN);
1020 	peerkey->akmp = sm->key_mgmt;
1021 
1022 	/* SMK M1:
1023 	 * EAPOL-Key(S=1, M=1, A=0, I=0, K=0, SM=1, KeyRSC=0, Nonce=INonce,
1024 	 *           MIC=MIC, DataKDs=(RSNIE_I, MAC_P KDE))
1025 	 */
1026 
1027 	hdr = (struct rsn_ie_hdr *) peerkey->rsnie_i;
1028 	hdr->elem_id = WLAN_EID_RSN;
1029 	WPA_PUT_LE16(hdr->version, RSN_VERSION);
1030 	pos = (u8 *) (hdr + 1);
1031 	/* Group Suite can be anything for SMK RSN IE; receiver will just
1032 	 * ignore it. */
1033 	RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
1034 	pos += RSN_SELECTOR_LEN;
1035 	count_pos = pos;
1036 	pos += 2;
1037 
1038 	count = rsn_cipher_put_suites(pos, sm->allowed_pairwise_cipher);
1039 	pos += count * RSN_SELECTOR_LEN;
1040 	WPA_PUT_LE16(count_pos, count);
1041 
1042 	hdr->len = (pos - peerkey->rsnie_i) - 2;
1043 	peerkey->rsnie_i_len = pos - peerkey->rsnie_i;
1044 	wpa_hexdump(MSG_DEBUG, "WPA: RSN IE for SMK handshake",
1045 		    peerkey->rsnie_i, peerkey->rsnie_i_len);
1046 
1047 	kde_len = peerkey->rsnie_i_len + 2 + RSN_SELECTOR_LEN + ETH_ALEN;
1048 
1049 	rbuf = wpa_sm_alloc_eapol(sm, IEEE802_1X_TYPE_EAPOL_KEY, NULL,
1050 				  sizeof(*req) + kde_len, &rlen,
1051 				  (void *) &req);
1052 	if (rbuf == NULL) {
1053 		wpa_supplicant_peerkey_free(sm, peerkey);
1054 		return -1;
1055 	}
1056 
1057 	req->type = EAPOL_KEY_TYPE_RSN;
1058 	key_info = WPA_KEY_INFO_SMK_MESSAGE | WPA_KEY_INFO_MIC |
1059 		WPA_KEY_INFO_SECURE | WPA_KEY_INFO_REQUEST | ver;
1060 	WPA_PUT_BE16(req->key_info, key_info);
1061 	WPA_PUT_BE16(req->key_length, 0);
1062 	os_memcpy(req->replay_counter, sm->request_counter,
1063 		  WPA_REPLAY_COUNTER_LEN);
1064 	inc_byte_array(sm->request_counter, WPA_REPLAY_COUNTER_LEN);
1065 
1066 	if (random_get_bytes(peerkey->inonce, WPA_NONCE_LEN)) {
1067 		wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
1068 			"WPA: Failed to get random data for INonce");
1069 		os_free(rbuf);
1070 		wpa_supplicant_peerkey_free(sm, peerkey);
1071 		return -1;
1072 	}
1073 	os_memcpy(req->key_nonce, peerkey->inonce, WPA_NONCE_LEN);
1074 	wpa_hexdump(MSG_DEBUG, "WPA: INonce for SMK handshake",
1075 		    req->key_nonce, WPA_NONCE_LEN);
1076 
1077 	WPA_PUT_BE16(req->key_data_length, (u16) kde_len);
1078 	pos = (u8 *) (req + 1);
1079 
1080 	/* Initiator RSN IE */
1081 	pos = wpa_add_ie(pos, peerkey->rsnie_i, peerkey->rsnie_i_len);
1082 	/* Peer MAC address KDE */
1083 	wpa_add_kde(pos, RSN_KEY_DATA_MAC_ADDR, peer, ETH_ALEN);
1084 
1085 	wpa_printf(MSG_INFO, "RSN: Sending EAPOL-Key SMK M1 Request (peer "
1086 		   MACSTR ")", MAC2STR(peer));
1087 	wpa_eapol_key_send(sm, sm->ptk.kck, sm->ptk.kck_len, ver, bssid,
1088 			   ETH_P_EAPOL, rbuf, rlen, req->key_mic);
1089 
1090 	peerkey->next = sm->peerkey;
1091 	sm->peerkey = peerkey;
1092 
1093 	return 0;
1094 }
1095 
1096 
1097 /**
1098  * peerkey_deinit - Free PeerKey values
1099  * @sm: Pointer to WPA state machine data from wpa_sm_init()
1100  */
peerkey_deinit(struct wpa_sm * sm)1101 void peerkey_deinit(struct wpa_sm *sm)
1102 {
1103 	struct wpa_peerkey *prev, *peerkey = sm->peerkey;
1104 	while (peerkey) {
1105 		prev = peerkey;
1106 		peerkey = peerkey->next;
1107 		wpa_supplicant_peerkey_free(sm, prev);
1108 	}
1109 	sm->peerkey = NULL;
1110 }
1111 
1112 
peerkey_rx_eapol_4way(struct wpa_sm * sm,struct wpa_peerkey * peerkey,struct wpa_eapol_key * key,u16 key_info,u16 ver,const u8 * key_data,size_t key_data_len)1113 void peerkey_rx_eapol_4way(struct wpa_sm *sm, struct wpa_peerkey *peerkey,
1114 			   struct wpa_eapol_key *key, u16 key_info, u16 ver,
1115 			   const u8 *key_data, size_t key_data_len)
1116 {
1117 	if ((key_info & (WPA_KEY_INFO_MIC | WPA_KEY_INFO_ACK)) ==
1118 	    (WPA_KEY_INFO_MIC | WPA_KEY_INFO_ACK)) {
1119 		/* 3/4 STK 4-Way Handshake */
1120 		wpa_supplicant_process_stk_3_of_4(sm, peerkey, key, ver,
1121 						  key_data, key_data_len);
1122 	} else if (key_info & WPA_KEY_INFO_ACK) {
1123 		/* 1/4 STK 4-Way Handshake */
1124 		wpa_supplicant_process_stk_1_of_4(sm, peerkey, key, ver,
1125 						  key_data, key_data_len);
1126 	} else if (key_info & WPA_KEY_INFO_SECURE) {
1127 		/* 4/4 STK 4-Way Handshake */
1128 		wpa_supplicant_process_stk_4_of_4(sm, peerkey, key, ver);
1129 	} else {
1130 		/* 2/4 STK 4-Way Handshake */
1131 		wpa_supplicant_process_stk_2_of_4(sm, peerkey, key, ver,
1132 						  key_data, key_data_len);
1133 	}
1134 }
1135 
1136 
peerkey_rx_eapol_smk(struct wpa_sm * sm,const u8 * src_addr,struct wpa_eapol_key * key,size_t extra_len,u16 key_info,u16 ver)1137 void peerkey_rx_eapol_smk(struct wpa_sm *sm, const u8 *src_addr,
1138 			  struct wpa_eapol_key *key, size_t extra_len,
1139 			  u16 key_info, u16 ver)
1140 {
1141 	if (key_info & WPA_KEY_INFO_ERROR) {
1142 		/* SMK Error */
1143 		wpa_supplicant_process_smk_error(sm, src_addr, key, extra_len);
1144 	} else if (key_info & WPA_KEY_INFO_ACK) {
1145 		/* SMK M2 */
1146 		wpa_supplicant_process_smk_m2(sm, src_addr, key, extra_len,
1147 					      ver);
1148 	} else {
1149 		/* SMK M4 or M5 */
1150 		wpa_supplicant_process_smk_m45(sm, src_addr, key, extra_len,
1151 					       ver);
1152 	}
1153 }
1154 
1155 #endif /* CONFIG_PEERKEY */
1156