1/*
2 * wpa_supplicant - WPA/RSN IE and KDE processing
3 * Copyright (c) 2003-2008, 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#include "common.h"
12#include "wpa.h"
13#include "pmksa_cache.h"
14#include "common/ieee802_11_defs.h"
15#include "wpa_i.h"
16#include "wpa_ie.h"
17
18
19/**
20 * wpa_parse_wpa_ie - Parse WPA/RSN IE
21 * @wpa_ie: Pointer to WPA or RSN IE
22 * @wpa_ie_len: Length of the WPA/RSN IE
23 * @data: Pointer to data area for parsing results
24 * Returns: 0 on success, -1 on failure
25 *
26 * Parse the contents of WPA or RSN IE and write the parsed data into data.
27 */
28int wpa_parse_wpa_ie(const u8 *wpa_ie, size_t wpa_ie_len,
29		     struct wpa_ie_data *data)
30{
31	if (wpa_ie_len >= 1 && wpa_ie[0] == WLAN_EID_RSN)
32		return wpa_parse_wpa_ie_rsn(wpa_ie, wpa_ie_len, data);
33	else
34		return wpa_parse_wpa_ie_wpa(wpa_ie, wpa_ie_len, data);
35}
36
37
38static int wpa_gen_wpa_ie_wpa(u8 *wpa_ie, size_t wpa_ie_len,
39			      int pairwise_cipher, int group_cipher,
40			      int key_mgmt)
41{
42	u8 *pos;
43	struct wpa_ie_hdr *hdr;
44	u32 suite;
45
46	if (wpa_ie_len < sizeof(*hdr) + WPA_SELECTOR_LEN +
47	    2 + WPA_SELECTOR_LEN + 2 + WPA_SELECTOR_LEN)
48		return -1;
49
50	hdr = (struct wpa_ie_hdr *) wpa_ie;
51	hdr->elem_id = WLAN_EID_VENDOR_SPECIFIC;
52	RSN_SELECTOR_PUT(hdr->oui, WPA_OUI_TYPE);
53	WPA_PUT_LE16(hdr->version, WPA_VERSION);
54	pos = (u8 *) (hdr + 1);
55
56	suite = wpa_cipher_to_suite(WPA_PROTO_WPA, group_cipher);
57	if (suite == 0) {
58		wpa_printf(MSG_WARNING, "Invalid group cipher (%d).",
59			   group_cipher);
60		return -1;
61	}
62	RSN_SELECTOR_PUT(pos, suite);
63	pos += WPA_SELECTOR_LEN;
64
65	*pos++ = 1;
66	*pos++ = 0;
67	suite = wpa_cipher_to_suite(WPA_PROTO_WPA, pairwise_cipher);
68	if (suite == 0 ||
69	    (!wpa_cipher_valid_pairwise(pairwise_cipher) &&
70	     pairwise_cipher != WPA_CIPHER_NONE)) {
71		wpa_printf(MSG_WARNING, "Invalid pairwise cipher (%d).",
72			   pairwise_cipher);
73		return -1;
74	}
75	RSN_SELECTOR_PUT(pos, suite);
76	pos += WPA_SELECTOR_LEN;
77
78	*pos++ = 1;
79	*pos++ = 0;
80	if (key_mgmt == WPA_KEY_MGMT_IEEE8021X) {
81		RSN_SELECTOR_PUT(pos, WPA_AUTH_KEY_MGMT_UNSPEC_802_1X);
82	} else if (key_mgmt == WPA_KEY_MGMT_PSK) {
83		RSN_SELECTOR_PUT(pos, WPA_AUTH_KEY_MGMT_PSK_OVER_802_1X);
84	} else if (key_mgmt == WPA_KEY_MGMT_WPA_NONE) {
85		RSN_SELECTOR_PUT(pos, WPA_AUTH_KEY_MGMT_NONE);
86	} else {
87		wpa_printf(MSG_WARNING, "Invalid key management type (%d).",
88			   key_mgmt);
89		return -1;
90	}
91	pos += WPA_SELECTOR_LEN;
92
93	/* WPA Capabilities; use defaults, so no need to include it */
94
95	hdr->len = (pos - wpa_ie) - 2;
96
97	WPA_ASSERT((size_t) (pos - wpa_ie) <= wpa_ie_len);
98
99	return pos - wpa_ie;
100}
101
102
103static int wpa_gen_wpa_ie_rsn(u8 *rsn_ie, size_t rsn_ie_len,
104			      int pairwise_cipher, int group_cipher,
105			      int key_mgmt, int mgmt_group_cipher,
106			      struct wpa_sm *sm)
107{
108#ifndef CONFIG_NO_WPA2
109	u8 *pos;
110	struct rsn_ie_hdr *hdr;
111	u16 capab;
112	u32 suite;
113
114	if (rsn_ie_len < sizeof(*hdr) + RSN_SELECTOR_LEN +
115	    2 + RSN_SELECTOR_LEN + 2 + RSN_SELECTOR_LEN + 2 +
116	    (sm->cur_pmksa ? 2 + PMKID_LEN : 0)) {
117		wpa_printf(MSG_DEBUG, "RSN: Too short IE buffer (%lu bytes)",
118			   (unsigned long) rsn_ie_len);
119		return -1;
120	}
121
122	hdr = (struct rsn_ie_hdr *) rsn_ie;
123	hdr->elem_id = WLAN_EID_RSN;
124	WPA_PUT_LE16(hdr->version, RSN_VERSION);
125	pos = (u8 *) (hdr + 1);
126
127	suite = wpa_cipher_to_suite(WPA_PROTO_RSN, group_cipher);
128	if (suite == 0) {
129		wpa_printf(MSG_WARNING, "Invalid group cipher (%d).",
130			   group_cipher);
131		return -1;
132	}
133	RSN_SELECTOR_PUT(pos, suite);
134	pos += RSN_SELECTOR_LEN;
135
136	*pos++ = 1;
137	*pos++ = 0;
138	suite = wpa_cipher_to_suite(WPA_PROTO_RSN, pairwise_cipher);
139	if (suite == 0 ||
140	    (!wpa_cipher_valid_pairwise(pairwise_cipher) &&
141	     pairwise_cipher != WPA_CIPHER_NONE)) {
142		wpa_printf(MSG_WARNING, "Invalid pairwise cipher (%d).",
143			   pairwise_cipher);
144		return -1;
145	}
146	RSN_SELECTOR_PUT(pos, suite);
147	pos += RSN_SELECTOR_LEN;
148
149	*pos++ = 1;
150	*pos++ = 0;
151	if (key_mgmt == WPA_KEY_MGMT_IEEE8021X) {
152		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_UNSPEC_802_1X);
153	} else if (key_mgmt == WPA_KEY_MGMT_PSK) {
154		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_PSK_OVER_802_1X);
155#ifdef CONFIG_IEEE80211R
156	} else if (key_mgmt == WPA_KEY_MGMT_FT_IEEE8021X) {
157		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_FT_802_1X);
158	} else if (key_mgmt == WPA_KEY_MGMT_FT_PSK) {
159		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_FT_PSK);
160#endif /* CONFIG_IEEE80211R */
161#ifdef CONFIG_IEEE80211W
162	} else if (key_mgmt == WPA_KEY_MGMT_IEEE8021X_SHA256) {
163		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_802_1X_SHA256);
164	} else if (key_mgmt == WPA_KEY_MGMT_PSK_SHA256) {
165		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_PSK_SHA256);
166#endif /* CONFIG_IEEE80211W */
167	} else {
168		wpa_printf(MSG_WARNING, "Invalid key management type (%d).",
169			   key_mgmt);
170		return -1;
171	}
172	pos += RSN_SELECTOR_LEN;
173
174	/* RSN Capabilities */
175	capab = 0;
176#ifdef CONFIG_IEEE80211W
177	if (sm->mfp)
178		capab |= WPA_CAPABILITY_MFPC;
179	if (sm->mfp == 2)
180		capab |= WPA_CAPABILITY_MFPR;
181#endif /* CONFIG_IEEE80211W */
182	WPA_PUT_LE16(pos, capab);
183	pos += 2;
184
185	if (sm->cur_pmksa) {
186		/* PMKID Count (2 octets, little endian) */
187		*pos++ = 1;
188		*pos++ = 0;
189		/* PMKID */
190		os_memcpy(pos, sm->cur_pmksa->pmkid, PMKID_LEN);
191		pos += PMKID_LEN;
192	}
193
194#ifdef CONFIG_IEEE80211W
195	if (mgmt_group_cipher == WPA_CIPHER_AES_128_CMAC) {
196		if (!sm->cur_pmksa) {
197			/* PMKID Count */
198			WPA_PUT_LE16(pos, 0);
199			pos += 2;
200		}
201
202		/* Management Group Cipher Suite */
203		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_AES_128_CMAC);
204		pos += RSN_SELECTOR_LEN;
205	}
206#endif /* CONFIG_IEEE80211W */
207
208	hdr->len = (pos - rsn_ie) - 2;
209
210	WPA_ASSERT((size_t) (pos - rsn_ie) <= rsn_ie_len);
211
212	return pos - rsn_ie;
213#else /* CONFIG_NO_WPA2 */
214	return -1;
215#endif /* CONFIG_NO_WPA2 */
216}
217
218
219/**
220 * wpa_gen_wpa_ie - Generate WPA/RSN IE based on current security policy
221 * @sm: Pointer to WPA state machine data from wpa_sm_init()
222 * @wpa_ie: Pointer to memory area for the generated WPA/RSN IE
223 * @wpa_ie_len: Maximum length of the generated WPA/RSN IE
224 * Returns: Length of the generated WPA/RSN IE or -1 on failure
225 */
226int wpa_gen_wpa_ie(struct wpa_sm *sm, u8 *wpa_ie, size_t wpa_ie_len)
227{
228	if (sm->proto == WPA_PROTO_RSN)
229		return wpa_gen_wpa_ie_rsn(wpa_ie, wpa_ie_len,
230					  sm->pairwise_cipher,
231					  sm->group_cipher,
232					  sm->key_mgmt, sm->mgmt_group_cipher,
233					  sm);
234	else
235		return wpa_gen_wpa_ie_wpa(wpa_ie, wpa_ie_len,
236					  sm->pairwise_cipher,
237					  sm->group_cipher,
238					  sm->key_mgmt);
239}
240
241
242/**
243 * wpa_parse_generic - Parse EAPOL-Key Key Data Generic IEs
244 * @pos: Pointer to the IE header
245 * @end: Pointer to the end of the Key Data buffer
246 * @ie: Pointer to parsed IE data
247 * Returns: 0 on success, 1 if end mark is found, -1 on failure
248 */
249static int wpa_parse_generic(const u8 *pos, const u8 *end,
250			     struct wpa_eapol_ie_parse *ie)
251{
252	if (pos[1] == 0)
253		return 1;
254
255	if (pos[1] >= 6 &&
256	    RSN_SELECTOR_GET(pos + 2) == WPA_OUI_TYPE &&
257	    pos[2 + WPA_SELECTOR_LEN] == 1 &&
258	    pos[2 + WPA_SELECTOR_LEN + 1] == 0) {
259		ie->wpa_ie = pos;
260		ie->wpa_ie_len = pos[1] + 2;
261		wpa_hexdump(MSG_DEBUG, "WPA: WPA IE in EAPOL-Key",
262			    ie->wpa_ie, ie->wpa_ie_len);
263		return 0;
264	}
265
266	if (pos + 1 + RSN_SELECTOR_LEN < end &&
267	    pos[1] >= RSN_SELECTOR_LEN + PMKID_LEN &&
268	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_PMKID) {
269		ie->pmkid = pos + 2 + RSN_SELECTOR_LEN;
270		wpa_hexdump(MSG_DEBUG, "WPA: PMKID in EAPOL-Key",
271			    pos, pos[1] + 2);
272		return 0;
273	}
274
275	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
276	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_GROUPKEY) {
277		ie->gtk = pos + 2 + RSN_SELECTOR_LEN;
278		ie->gtk_len = pos[1] - RSN_SELECTOR_LEN;
279		wpa_hexdump_key(MSG_DEBUG, "WPA: GTK in EAPOL-Key",
280				pos, pos[1] + 2);
281		return 0;
282	}
283
284	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
285	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_MAC_ADDR) {
286		ie->mac_addr = pos + 2 + RSN_SELECTOR_LEN;
287		ie->mac_addr_len = pos[1] - RSN_SELECTOR_LEN;
288		wpa_hexdump(MSG_DEBUG, "WPA: MAC Address in EAPOL-Key",
289			    pos, pos[1] + 2);
290		return 0;
291	}
292
293#ifdef CONFIG_PEERKEY
294	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
295	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_SMK) {
296		ie->smk = pos + 2 + RSN_SELECTOR_LEN;
297		ie->smk_len = pos[1] - RSN_SELECTOR_LEN;
298		wpa_hexdump_key(MSG_DEBUG, "WPA: SMK in EAPOL-Key",
299				pos, pos[1] + 2);
300		return 0;
301	}
302
303	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
304	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_NONCE) {
305		ie->nonce = pos + 2 + RSN_SELECTOR_LEN;
306		ie->nonce_len = pos[1] - RSN_SELECTOR_LEN;
307		wpa_hexdump(MSG_DEBUG, "WPA: Nonce in EAPOL-Key",
308			    pos, pos[1] + 2);
309		return 0;
310	}
311
312	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
313	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_LIFETIME) {
314		ie->lifetime = pos + 2 + RSN_SELECTOR_LEN;
315		ie->lifetime_len = pos[1] - RSN_SELECTOR_LEN;
316		wpa_hexdump(MSG_DEBUG, "WPA: Lifetime in EAPOL-Key",
317			    pos, pos[1] + 2);
318		return 0;
319	}
320
321	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
322	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_ERROR) {
323		ie->error = pos + 2 + RSN_SELECTOR_LEN;
324		ie->error_len = pos[1] - RSN_SELECTOR_LEN;
325		wpa_hexdump(MSG_DEBUG, "WPA: Error in EAPOL-Key",
326			    pos, pos[1] + 2);
327		return 0;
328	}
329#endif /* CONFIG_PEERKEY */
330
331#ifdef CONFIG_IEEE80211W
332	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
333	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_IGTK) {
334		ie->igtk = pos + 2 + RSN_SELECTOR_LEN;
335		ie->igtk_len = pos[1] - RSN_SELECTOR_LEN;
336		wpa_hexdump_key(MSG_DEBUG, "WPA: IGTK in EAPOL-Key",
337				pos, pos[1] + 2);
338		return 0;
339	}
340#endif /* CONFIG_IEEE80211W */
341
342	return 0;
343}
344
345
346/**
347 * wpa_supplicant_parse_ies - Parse EAPOL-Key Key Data IEs
348 * @buf: Pointer to the Key Data buffer
349 * @len: Key Data Length
350 * @ie: Pointer to parsed IE data
351 * Returns: 0 on success, -1 on failure
352 */
353int wpa_supplicant_parse_ies(const u8 *buf, size_t len,
354			     struct wpa_eapol_ie_parse *ie)
355{
356	const u8 *pos, *end;
357	int ret = 0;
358
359	os_memset(ie, 0, sizeof(*ie));
360	for (pos = buf, end = pos + len; pos + 1 < end; pos += 2 + pos[1]) {
361		if (pos[0] == 0xdd &&
362		    ((pos == buf + len - 1) || pos[1] == 0)) {
363			/* Ignore padding */
364			break;
365		}
366		if (pos + 2 + pos[1] > end) {
367			wpa_printf(MSG_DEBUG, "WPA: EAPOL-Key Key Data "
368				   "underflow (ie=%d len=%d pos=%d)",
369				   pos[0], pos[1], (int) (pos - buf));
370			wpa_hexdump_key(MSG_DEBUG, "WPA: Key Data",
371					buf, len);
372			ret = -1;
373			break;
374		}
375		if (*pos == WLAN_EID_RSN) {
376			ie->rsn_ie = pos;
377			ie->rsn_ie_len = pos[1] + 2;
378			wpa_hexdump(MSG_DEBUG, "WPA: RSN IE in EAPOL-Key",
379				    ie->rsn_ie, ie->rsn_ie_len);
380		} else if (*pos == WLAN_EID_MOBILITY_DOMAIN) {
381			ie->mdie = pos;
382			ie->mdie_len = pos[1] + 2;
383			wpa_hexdump(MSG_DEBUG, "WPA: MDIE in EAPOL-Key",
384				    ie->mdie, ie->mdie_len);
385		} else if (*pos == WLAN_EID_FAST_BSS_TRANSITION) {
386			ie->ftie = pos;
387			ie->ftie_len = pos[1] + 2;
388			wpa_hexdump(MSG_DEBUG, "WPA: FTIE in EAPOL-Key",
389				    ie->ftie, ie->ftie_len);
390		} else if (*pos == WLAN_EID_TIMEOUT_INTERVAL && pos[1] >= 5) {
391			if (pos[2] == WLAN_TIMEOUT_REASSOC_DEADLINE) {
392				ie->reassoc_deadline = pos;
393				wpa_hexdump(MSG_DEBUG, "WPA: Reassoc Deadline "
394					    "in EAPOL-Key",
395					    ie->reassoc_deadline, pos[1] + 2);
396			} else if (pos[2] == WLAN_TIMEOUT_KEY_LIFETIME) {
397				ie->key_lifetime = pos;
398				wpa_hexdump(MSG_DEBUG, "WPA: KeyLifetime "
399					    "in EAPOL-Key",
400					    ie->key_lifetime, pos[1] + 2);
401			} else {
402				wpa_hexdump(MSG_DEBUG, "WPA: Unrecognized "
403					    "EAPOL-Key Key Data IE",
404					    pos, 2 + pos[1]);
405			}
406		} else if (*pos == WLAN_EID_LINK_ID) {
407			if (pos[1] >= 18) {
408				ie->lnkid = pos;
409				ie->lnkid_len = pos[1] + 2;
410			}
411		} else if (*pos == WLAN_EID_EXT_CAPAB) {
412			ie->ext_capab = pos;
413			ie->ext_capab_len = pos[1] + 2;
414		} else if (*pos == WLAN_EID_SUPP_RATES) {
415			ie->supp_rates = pos;
416			ie->supp_rates_len = pos[1] + 2;
417		} else if (*pos == WLAN_EID_EXT_SUPP_RATES) {
418			ie->ext_supp_rates = pos;
419			ie->ext_supp_rates_len = pos[1] + 2;
420		} else if (*pos == WLAN_EID_VENDOR_SPECIFIC) {
421			ret = wpa_parse_generic(pos, end, ie);
422			if (ret < 0)
423				break;
424			if (ret > 0) {
425				ret = 0;
426				break;
427			}
428		} else {
429			wpa_hexdump(MSG_DEBUG, "WPA: Unrecognized EAPOL-Key "
430				    "Key Data IE", pos, 2 + pos[1]);
431		}
432	}
433
434	return ret;
435}
436