1/*
2 * wpa_supplicant - WPA/RSN IE and KDE processing
3 * Copyright (c) 2003-2008, 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 "wpa.h"
19#include "pmksa_cache.h"
20#include "ieee802_11_defs.h"
21#include "wpa_i.h"
22#include "wpa_ie.h"
23
24
25static int wpa_selector_to_bitfield(const u8 *s)
26{
27	if (RSN_SELECTOR_GET(s) == WPA_CIPHER_SUITE_NONE)
28		return WPA_CIPHER_NONE;
29	if (RSN_SELECTOR_GET(s) == WPA_CIPHER_SUITE_WEP40)
30		return WPA_CIPHER_WEP40;
31	if (RSN_SELECTOR_GET(s) == WPA_CIPHER_SUITE_TKIP)
32		return WPA_CIPHER_TKIP;
33	if (RSN_SELECTOR_GET(s) == WPA_CIPHER_SUITE_CCMP)
34		return WPA_CIPHER_CCMP;
35	if (RSN_SELECTOR_GET(s) == WPA_CIPHER_SUITE_WEP104)
36		return WPA_CIPHER_WEP104;
37	return 0;
38}
39
40
41static int wpa_key_mgmt_to_bitfield(const u8 *s)
42{
43	if (RSN_SELECTOR_GET(s) == WPA_AUTH_KEY_MGMT_UNSPEC_802_1X)
44		return WPA_KEY_MGMT_IEEE8021X;
45	if (RSN_SELECTOR_GET(s) == WPA_AUTH_KEY_MGMT_PSK_OVER_802_1X)
46		return WPA_KEY_MGMT_PSK;
47	if (RSN_SELECTOR_GET(s) == WPA_AUTH_KEY_MGMT_NONE)
48		return WPA_KEY_MGMT_WPA_NONE;
49	return 0;
50}
51
52
53static int wpa_parse_wpa_ie_wpa(const u8 *wpa_ie, size_t wpa_ie_len,
54				struct wpa_ie_data *data)
55{
56	const struct wpa_ie_hdr *hdr;
57	const u8 *pos;
58	int left;
59	int i, count;
60
61	os_memset(data, 0, sizeof(*data));
62	data->proto = WPA_PROTO_WPA;
63	data->pairwise_cipher = WPA_CIPHER_TKIP;
64	data->group_cipher = WPA_CIPHER_TKIP;
65	data->key_mgmt = WPA_KEY_MGMT_IEEE8021X;
66	data->capabilities = 0;
67	data->pmkid = NULL;
68	data->num_pmkid = 0;
69	data->mgmt_group_cipher = 0;
70
71	if (wpa_ie_len == 0) {
72		/* No WPA IE - fail silently */
73		return -1;
74	}
75
76	if (wpa_ie_len < sizeof(struct wpa_ie_hdr)) {
77		wpa_printf(MSG_DEBUG, "%s: ie len too short %lu",
78			   __func__, (unsigned long) wpa_ie_len);
79		return -1;
80	}
81
82	hdr = (const struct wpa_ie_hdr *) wpa_ie;
83
84	if (hdr->elem_id != WLAN_EID_VENDOR_SPECIFIC ||
85	    hdr->len != wpa_ie_len - 2 ||
86	    RSN_SELECTOR_GET(hdr->oui) != WPA_OUI_TYPE ||
87	    WPA_GET_LE16(hdr->version) != WPA_VERSION) {
88		wpa_printf(MSG_DEBUG, "%s: malformed ie or unknown version",
89			   __func__);
90		return -1;
91	}
92
93	pos = (const u8 *) (hdr + 1);
94	left = wpa_ie_len - sizeof(*hdr);
95
96	if (left >= WPA_SELECTOR_LEN) {
97		data->group_cipher = wpa_selector_to_bitfield(pos);
98		pos += WPA_SELECTOR_LEN;
99		left -= WPA_SELECTOR_LEN;
100	} else if (left > 0) {
101		wpa_printf(MSG_DEBUG, "%s: ie length mismatch, %u too much",
102			   __func__, left);
103		return -1;
104	}
105
106	if (left >= 2) {
107		data->pairwise_cipher = 0;
108		count = WPA_GET_LE16(pos);
109		pos += 2;
110		left -= 2;
111		if (count == 0 || left < count * WPA_SELECTOR_LEN) {
112			wpa_printf(MSG_DEBUG, "%s: ie count botch (pairwise), "
113				   "count %u left %u", __func__, count, left);
114			return -1;
115		}
116		for (i = 0; i < count; i++) {
117			data->pairwise_cipher |= wpa_selector_to_bitfield(pos);
118			pos += WPA_SELECTOR_LEN;
119			left -= WPA_SELECTOR_LEN;
120		}
121	} else if (left == 1) {
122		wpa_printf(MSG_DEBUG, "%s: ie too short (for key mgmt)",
123			   __func__);
124		return -1;
125	}
126
127	if (left >= 2) {
128		data->key_mgmt = 0;
129		count = WPA_GET_LE16(pos);
130		pos += 2;
131		left -= 2;
132		if (count == 0 || left < count * WPA_SELECTOR_LEN) {
133			wpa_printf(MSG_DEBUG, "%s: ie count botch (key mgmt), "
134				   "count %u left %u", __func__, count, left);
135			return -1;
136		}
137		for (i = 0; i < count; i++) {
138			data->key_mgmt |= wpa_key_mgmt_to_bitfield(pos);
139			pos += WPA_SELECTOR_LEN;
140			left -= WPA_SELECTOR_LEN;
141		}
142	} else if (left == 1) {
143		wpa_printf(MSG_DEBUG, "%s: ie too short (for capabilities)",
144			   __func__);
145		return -1;
146	}
147
148	if (left >= 2) {
149		data->capabilities = WPA_GET_LE16(pos);
150		pos += 2;
151		left -= 2;
152	}
153
154	if (left > 0) {
155		wpa_printf(MSG_DEBUG, "%s: ie has %u trailing bytes - ignored",
156			   __func__, left);
157	}
158
159	return 0;
160}
161
162
163/**
164 * wpa_parse_wpa_ie - Parse WPA/RSN IE
165 * @wpa_ie: Pointer to WPA or RSN IE
166 * @wpa_ie_len: Length of the WPA/RSN IE
167 * @data: Pointer to data area for parsing results
168 * Returns: 0 on success, -1 on failure
169 *
170 * Parse the contents of WPA or RSN IE and write the parsed data into data.
171 */
172int wpa_parse_wpa_ie(const u8 *wpa_ie, size_t wpa_ie_len,
173		     struct wpa_ie_data *data)
174{
175	if (wpa_ie_len >= 1 && wpa_ie[0] == WLAN_EID_RSN)
176		return wpa_parse_wpa_ie_rsn(wpa_ie, wpa_ie_len, data);
177	else
178		return wpa_parse_wpa_ie_wpa(wpa_ie, wpa_ie_len, data);
179}
180
181
182static int wpa_gen_wpa_ie_wpa(u8 *wpa_ie, size_t wpa_ie_len,
183			      int pairwise_cipher, int group_cipher,
184			      int key_mgmt)
185{
186	u8 *pos;
187	struct wpa_ie_hdr *hdr;
188
189	if (wpa_ie_len < sizeof(*hdr) + WPA_SELECTOR_LEN +
190	    2 + WPA_SELECTOR_LEN + 2 + WPA_SELECTOR_LEN)
191		return -1;
192
193	hdr = (struct wpa_ie_hdr *) wpa_ie;
194	hdr->elem_id = WLAN_EID_VENDOR_SPECIFIC;
195	RSN_SELECTOR_PUT(hdr->oui, WPA_OUI_TYPE);
196	WPA_PUT_LE16(hdr->version, WPA_VERSION);
197	pos = (u8 *) (hdr + 1);
198
199	if (group_cipher == WPA_CIPHER_CCMP) {
200		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_CCMP);
201	} else if (group_cipher == WPA_CIPHER_TKIP) {
202		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_TKIP);
203	} else if (group_cipher == WPA_CIPHER_WEP104) {
204		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_WEP104);
205	} else if (group_cipher == WPA_CIPHER_WEP40) {
206		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_WEP40);
207	} else {
208		wpa_printf(MSG_WARNING, "Invalid group cipher (%d).",
209			   group_cipher);
210		return -1;
211	}
212	pos += WPA_SELECTOR_LEN;
213
214	*pos++ = 1;
215	*pos++ = 0;
216	if (pairwise_cipher == WPA_CIPHER_CCMP) {
217		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_CCMP);
218	} else if (pairwise_cipher == WPA_CIPHER_TKIP) {
219		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_TKIP);
220	} else if (pairwise_cipher == WPA_CIPHER_NONE) {
221		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_NONE);
222	} else {
223		wpa_printf(MSG_WARNING, "Invalid pairwise cipher (%d).",
224			   pairwise_cipher);
225		return -1;
226	}
227	pos += WPA_SELECTOR_LEN;
228
229	*pos++ = 1;
230	*pos++ = 0;
231	if (key_mgmt == WPA_KEY_MGMT_IEEE8021X) {
232		RSN_SELECTOR_PUT(pos, WPA_AUTH_KEY_MGMT_UNSPEC_802_1X);
233	} else if (key_mgmt == WPA_KEY_MGMT_PSK) {
234		RSN_SELECTOR_PUT(pos, WPA_AUTH_KEY_MGMT_PSK_OVER_802_1X);
235	} else if (key_mgmt == WPA_KEY_MGMT_WPA_NONE) {
236		RSN_SELECTOR_PUT(pos, WPA_AUTH_KEY_MGMT_NONE);
237	} else {
238		wpa_printf(MSG_WARNING, "Invalid key management type (%d).",
239			   key_mgmt);
240		return -1;
241	}
242	pos += WPA_SELECTOR_LEN;
243
244	/* WPA Capabilities; use defaults, so no need to include it */
245
246	hdr->len = (pos - wpa_ie) - 2;
247
248	WPA_ASSERT((size_t) (pos - wpa_ie) <= wpa_ie_len);
249
250	return pos - wpa_ie;
251}
252
253
254static int wpa_gen_wpa_ie_rsn(u8 *rsn_ie, size_t rsn_ie_len,
255			      int pairwise_cipher, int group_cipher,
256			      int key_mgmt, int mgmt_group_cipher,
257			      struct wpa_sm *sm)
258{
259#ifndef CONFIG_NO_WPA2
260	u8 *pos;
261	struct rsn_ie_hdr *hdr;
262	u16 capab;
263
264	if (rsn_ie_len < sizeof(*hdr) + RSN_SELECTOR_LEN +
265	    2 + RSN_SELECTOR_LEN + 2 + RSN_SELECTOR_LEN + 2 +
266	    (sm->cur_pmksa ? 2 + PMKID_LEN : 0)) {
267		wpa_printf(MSG_DEBUG, "RSN: Too short IE buffer (%lu bytes)",
268			   (unsigned long) rsn_ie_len);
269		return -1;
270	}
271
272	hdr = (struct rsn_ie_hdr *) rsn_ie;
273	hdr->elem_id = WLAN_EID_RSN;
274	WPA_PUT_LE16(hdr->version, RSN_VERSION);
275	pos = (u8 *) (hdr + 1);
276
277	if (group_cipher == WPA_CIPHER_CCMP) {
278		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
279	} else if (group_cipher == WPA_CIPHER_TKIP) {
280		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_TKIP);
281	} else if (group_cipher == WPA_CIPHER_WEP104) {
282		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_WEP104);
283	} else if (group_cipher == WPA_CIPHER_WEP40) {
284		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_WEP40);
285	} else {
286		wpa_printf(MSG_WARNING, "Invalid group cipher (%d).",
287			   group_cipher);
288		return -1;
289	}
290	pos += RSN_SELECTOR_LEN;
291
292	*pos++ = 1;
293	*pos++ = 0;
294	if (pairwise_cipher == WPA_CIPHER_CCMP) {
295		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
296	} else if (pairwise_cipher == WPA_CIPHER_TKIP) {
297		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_TKIP);
298	} else if (pairwise_cipher == WPA_CIPHER_NONE) {
299		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_NONE);
300	} else {
301		wpa_printf(MSG_WARNING, "Invalid pairwise cipher (%d).",
302			   pairwise_cipher);
303		return -1;
304	}
305	pos += RSN_SELECTOR_LEN;
306
307	*pos++ = 1;
308	*pos++ = 0;
309	if (key_mgmt == WPA_KEY_MGMT_IEEE8021X) {
310		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_UNSPEC_802_1X);
311	} else if (key_mgmt == WPA_KEY_MGMT_PSK) {
312		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_PSK_OVER_802_1X);
313#ifdef CONFIG_IEEE80211R
314	} else if (key_mgmt == WPA_KEY_MGMT_FT_IEEE8021X) {
315		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_FT_802_1X);
316	} else if (key_mgmt == WPA_KEY_MGMT_FT_PSK) {
317		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_FT_PSK);
318#endif /* CONFIG_IEEE80211R */
319#ifdef CONFIG_IEEE80211W
320	} else if (key_mgmt == WPA_KEY_MGMT_IEEE8021X_SHA256) {
321		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_802_1X_SHA256);
322	} else if (key_mgmt == WPA_KEY_MGMT_PSK_SHA256) {
323		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_PSK_SHA256);
324#endif /* CONFIG_IEEE80211W */
325	} else {
326		wpa_printf(MSG_WARNING, "Invalid key management type (%d).",
327			   key_mgmt);
328		return -1;
329	}
330	pos += RSN_SELECTOR_LEN;
331
332	/* RSN Capabilities */
333	capab = 0;
334#ifdef CONFIG_IEEE80211W
335	if (mgmt_group_cipher == WPA_CIPHER_AES_128_CMAC)
336		capab |= WPA_CAPABILITY_MFPC;
337#endif /* CONFIG_IEEE80211W */
338	WPA_PUT_LE16(pos, capab);
339	pos += 2;
340
341	if (sm->cur_pmksa) {
342		/* PMKID Count (2 octets, little endian) */
343		*pos++ = 1;
344		*pos++ = 0;
345		/* PMKID */
346		os_memcpy(pos, sm->cur_pmksa->pmkid, PMKID_LEN);
347		pos += PMKID_LEN;
348	}
349
350#ifdef CONFIG_IEEE80211W
351	if (mgmt_group_cipher == WPA_CIPHER_AES_128_CMAC) {
352		if (!sm->cur_pmksa) {
353			/* PMKID Count */
354			WPA_PUT_LE16(pos, 0);
355			pos += 2;
356		}
357
358		/* Management Group Cipher Suite */
359		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_AES_128_CMAC);
360		pos += RSN_SELECTOR_LEN;
361	}
362#endif /* CONFIG_IEEE80211W */
363
364	hdr->len = (pos - rsn_ie) - 2;
365
366	WPA_ASSERT((size_t) (pos - rsn_ie) <= rsn_ie_len);
367
368	return pos - rsn_ie;
369#else /* CONFIG_NO_WPA2 */
370	return -1;
371#endif /* CONFIG_NO_WPA2 */
372}
373
374
375/**
376 * wpa_gen_wpa_ie - Generate WPA/RSN IE based on current security policy
377 * @sm: Pointer to WPA state machine data from wpa_sm_init()
378 * @wpa_ie: Pointer to memory area for the generated WPA/RSN IE
379 * @wpa_ie_len: Maximum length of the generated WPA/RSN IE
380 * Returns: Length of the generated WPA/RSN IE or -1 on failure
381 */
382int wpa_gen_wpa_ie(struct wpa_sm *sm, u8 *wpa_ie, size_t wpa_ie_len)
383{
384	if (sm->proto == WPA_PROTO_RSN)
385		return wpa_gen_wpa_ie_rsn(wpa_ie, wpa_ie_len,
386					  sm->pairwise_cipher,
387					  sm->group_cipher,
388					  sm->key_mgmt, sm->mgmt_group_cipher,
389					  sm);
390	else
391		return wpa_gen_wpa_ie_wpa(wpa_ie, wpa_ie_len,
392					  sm->pairwise_cipher,
393					  sm->group_cipher,
394					  sm->key_mgmt);
395}
396
397
398/**
399 * wpa_parse_generic - Parse EAPOL-Key Key Data Generic IEs
400 * @pos: Pointer to the IE header
401 * @end: Pointer to the end of the Key Data buffer
402 * @ie: Pointer to parsed IE data
403 * Returns: 0 on success, 1 if end mark is found, -1 on failure
404 */
405static int wpa_parse_generic(const u8 *pos, const u8 *end,
406			     struct wpa_eapol_ie_parse *ie)
407{
408	if (pos[1] == 0)
409		return 1;
410
411	if (pos[1] >= 6 &&
412	    RSN_SELECTOR_GET(pos + 2) == WPA_OUI_TYPE &&
413	    pos[2 + WPA_SELECTOR_LEN] == 1 &&
414	    pos[2 + WPA_SELECTOR_LEN + 1] == 0) {
415		ie->wpa_ie = pos;
416		ie->wpa_ie_len = pos[1] + 2;
417		return 0;
418	}
419
420	if (pos + 1 + RSN_SELECTOR_LEN < end &&
421	    pos[1] >= RSN_SELECTOR_LEN + PMKID_LEN &&
422	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_PMKID) {
423		ie->pmkid = pos + 2 + RSN_SELECTOR_LEN;
424		return 0;
425	}
426
427	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
428	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_GROUPKEY) {
429		ie->gtk = pos + 2 + RSN_SELECTOR_LEN;
430		ie->gtk_len = pos[1] - RSN_SELECTOR_LEN;
431		return 0;
432	}
433
434	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
435	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_MAC_ADDR) {
436		ie->mac_addr = pos + 2 + RSN_SELECTOR_LEN;
437		ie->mac_addr_len = pos[1] - RSN_SELECTOR_LEN;
438		return 0;
439	}
440
441#ifdef CONFIG_PEERKEY
442	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
443	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_SMK) {
444		ie->smk = pos + 2 + RSN_SELECTOR_LEN;
445		ie->smk_len = pos[1] - RSN_SELECTOR_LEN;
446		return 0;
447	}
448
449	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
450	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_NONCE) {
451		ie->nonce = pos + 2 + RSN_SELECTOR_LEN;
452		ie->nonce_len = pos[1] - RSN_SELECTOR_LEN;
453		return 0;
454	}
455
456	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
457	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_LIFETIME) {
458		ie->lifetime = pos + 2 + RSN_SELECTOR_LEN;
459		ie->lifetime_len = pos[1] - RSN_SELECTOR_LEN;
460		return 0;
461	}
462
463	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
464	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_ERROR) {
465		ie->error = pos + 2 + RSN_SELECTOR_LEN;
466		ie->error_len = pos[1] - RSN_SELECTOR_LEN;
467		return 0;
468	}
469#endif /* CONFIG_PEERKEY */
470
471#ifdef CONFIG_IEEE80211W
472	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
473	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_IGTK) {
474		ie->igtk = pos + 2 + RSN_SELECTOR_LEN;
475		ie->igtk_len = pos[1] - RSN_SELECTOR_LEN;
476		return 0;
477	}
478#endif /* CONFIG_IEEE80211W */
479
480	return 0;
481}
482
483
484/**
485 * wpa_supplicant_parse_ies - Parse EAPOL-Key Key Data IEs
486 * @buf: Pointer to the Key Data buffer
487 * @len: Key Data Length
488 * @ie: Pointer to parsed IE data
489 * Returns: 0 on success, -1 on failure
490 */
491int wpa_supplicant_parse_ies(const u8 *buf, size_t len,
492			     struct wpa_eapol_ie_parse *ie)
493{
494	const u8 *pos, *end;
495	int ret = 0;
496
497	os_memset(ie, 0, sizeof(*ie));
498	for (pos = buf, end = pos + len; pos + 1 < end; pos += 2 + pos[1]) {
499		if (pos[0] == 0xdd &&
500		    ((pos == buf + len - 1) || pos[1] == 0)) {
501			/* Ignore padding */
502			break;
503		}
504		if (pos + 2 + pos[1] > end) {
505			wpa_printf(MSG_DEBUG, "WPA: EAPOL-Key Key Data "
506				   "underflow (ie=%d len=%d pos=%d)",
507				   pos[0], pos[1], (int) (pos - buf));
508			wpa_hexdump_key(MSG_DEBUG, "WPA: Key Data",
509					buf, len);
510			ret = -1;
511			break;
512		}
513		if (*pos == WLAN_EID_RSN) {
514			ie->rsn_ie = pos;
515			ie->rsn_ie_len = pos[1] + 2;
516#ifdef CONFIG_IEEE80211R
517		} else if (*pos == WLAN_EID_MOBILITY_DOMAIN) {
518			ie->mdie = pos;
519			ie->mdie_len = pos[1] + 2;
520#endif /* CONFIG_IEEE80211R */
521		} else if (*pos == WLAN_EID_VENDOR_SPECIFIC) {
522			ret = wpa_parse_generic(pos, end, ie);
523			if (ret < 0)
524				break;
525			if (ret > 0) {
526				ret = 0;
527				break;
528			}
529		} else {
530			wpa_hexdump(MSG_DEBUG, "WPA: Unrecognized EAPOL-Key "
531				    "Key Data IE", pos, 2 + pos[1]);
532		}
533	}
534
535	return ret;
536}
537