wpa_ie.c revision 61d9df3e62aaa0e87ad05452fcb95142159a17b6 
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
45	if (wpa_ie_len < sizeof(*hdr) + WPA_SELECTOR_LEN +
46	    2 + WPA_SELECTOR_LEN + 2 + WPA_SELECTOR_LEN)
47		return -1;
48
49	hdr = (struct wpa_ie_hdr *) wpa_ie;
50	hdr->elem_id = WLAN_EID_VENDOR_SPECIFIC;
51	RSN_SELECTOR_PUT(hdr->oui, WPA_OUI_TYPE);
52	WPA_PUT_LE16(hdr->version, WPA_VERSION);
53	pos = (u8 *) (hdr + 1);
54
55	if (group_cipher == WPA_CIPHER_CCMP) {
56		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_CCMP);
57	} else if (group_cipher == WPA_CIPHER_TKIP) {
58		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_TKIP);
59	} else if (group_cipher == WPA_CIPHER_WEP104) {
60		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_WEP104);
61	} else if (group_cipher == WPA_CIPHER_WEP40) {
62		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_WEP40);
63	} else {
64		wpa_printf(MSG_WARNING, "Invalid group cipher (%d).",
65			   group_cipher);
66		return -1;
67	}
68	pos += WPA_SELECTOR_LEN;
69
70	*pos++ = 1;
71	*pos++ = 0;
72	if (pairwise_cipher == WPA_CIPHER_CCMP) {
73		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_CCMP);
74	} else if (pairwise_cipher == WPA_CIPHER_TKIP) {
75		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_TKIP);
76	} else if (pairwise_cipher == WPA_CIPHER_NONE) {
77		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_NONE);
78	} else {
79		wpa_printf(MSG_WARNING, "Invalid pairwise cipher (%d).",
80			   pairwise_cipher);
81		return -1;
82	}
83	pos += WPA_SELECTOR_LEN;
84
85	*pos++ = 1;
86	*pos++ = 0;
87	if (key_mgmt == WPA_KEY_MGMT_IEEE8021X) {
88		RSN_SELECTOR_PUT(pos, WPA_AUTH_KEY_MGMT_UNSPEC_802_1X);
89	} else if (key_mgmt == WPA_KEY_MGMT_PSK) {
90		RSN_SELECTOR_PUT(pos, WPA_AUTH_KEY_MGMT_PSK_OVER_802_1X);
91	} else if (key_mgmt == WPA_KEY_MGMT_WPA_NONE) {
92		RSN_SELECTOR_PUT(pos, WPA_AUTH_KEY_MGMT_NONE);
93	} else {
94		wpa_printf(MSG_WARNING, "Invalid key management type (%d).",
95			   key_mgmt);
96		return -1;
97	}
98	pos += WPA_SELECTOR_LEN;
99
100	/* WPA Capabilities; use defaults, so no need to include it */
101
102	hdr->len = (pos - wpa_ie) - 2;
103
104	WPA_ASSERT((size_t) (pos - wpa_ie) <= wpa_ie_len);
105
106	return pos - wpa_ie;
107}
108
109
110static int wpa_gen_wpa_ie_rsn(u8 *rsn_ie, size_t rsn_ie_len,
111			      int pairwise_cipher, int group_cipher,
112			      int key_mgmt, int mgmt_group_cipher,
113			      struct wpa_sm *sm)
114{
115#ifndef CONFIG_NO_WPA2
116	u8 *pos;
117	struct rsn_ie_hdr *hdr;
118	u16 capab;
119
120	if (rsn_ie_len < sizeof(*hdr) + RSN_SELECTOR_LEN +
121	    2 + RSN_SELECTOR_LEN + 2 + RSN_SELECTOR_LEN + 2 +
122	    (sm->cur_pmksa ? 2 + PMKID_LEN : 0)) {
123		wpa_printf(MSG_DEBUG, "RSN: Too short IE buffer (%lu bytes)",
124			   (unsigned long) rsn_ie_len);
125		return -1;
126	}
127
128	hdr = (struct rsn_ie_hdr *) rsn_ie;
129	hdr->elem_id = WLAN_EID_RSN;
130	WPA_PUT_LE16(hdr->version, RSN_VERSION);
131	pos = (u8 *) (hdr + 1);
132
133	if (group_cipher == WPA_CIPHER_CCMP) {
134		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
135	} else if (group_cipher == WPA_CIPHER_GCMP) {
136		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_GCMP);
137	} else if (group_cipher == WPA_CIPHER_TKIP) {
138		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_TKIP);
139	} else if (group_cipher == WPA_CIPHER_WEP104) {
140		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_WEP104);
141	} else if (group_cipher == WPA_CIPHER_WEP40) {
142		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_WEP40);
143	} else {
144		wpa_printf(MSG_WARNING, "Invalid group cipher (%d).",
145			   group_cipher);
146		return -1;
147	}
148	pos += RSN_SELECTOR_LEN;
149
150	*pos++ = 1;
151	*pos++ = 0;
152	if (pairwise_cipher == WPA_CIPHER_CCMP) {
153		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
154	} else if (pairwise_cipher == WPA_CIPHER_GCMP) {
155		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_GCMP);
156	} else if (pairwise_cipher == WPA_CIPHER_TKIP) {
157		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_TKIP);
158	} else if (pairwise_cipher == WPA_CIPHER_NONE) {
159		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_NONE);
160	} else {
161		wpa_printf(MSG_WARNING, "Invalid pairwise cipher (%d).",
162			   pairwise_cipher);
163		return -1;
164	}
165	pos += RSN_SELECTOR_LEN;
166
167	*pos++ = 1;
168	*pos++ = 0;
169	if (key_mgmt == WPA_KEY_MGMT_IEEE8021X) {
170		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_UNSPEC_802_1X);
171	} else if (key_mgmt == WPA_KEY_MGMT_PSK) {
172		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_PSK_OVER_802_1X);
173#ifdef CONFIG_IEEE80211R
174	} else if (key_mgmt == WPA_KEY_MGMT_FT_IEEE8021X) {
175		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_FT_802_1X);
176	} else if (key_mgmt == WPA_KEY_MGMT_FT_PSK) {
177		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_FT_PSK);
178#endif /* CONFIG_IEEE80211R */
179#ifdef CONFIG_IEEE80211W
180	} else if (key_mgmt == WPA_KEY_MGMT_IEEE8021X_SHA256) {
181		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_802_1X_SHA256);
182	} else if (key_mgmt == WPA_KEY_MGMT_PSK_SHA256) {
183		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_PSK_SHA256);
184#endif /* CONFIG_IEEE80211W */
185	} else {
186		wpa_printf(MSG_WARNING, "Invalid key management type (%d).",
187			   key_mgmt);
188		return -1;
189	}
190	pos += RSN_SELECTOR_LEN;
191
192	/* RSN Capabilities */
193	capab = 0;
194#ifdef CONFIG_IEEE80211W
195	if (sm->mfp)
196		capab |= WPA_CAPABILITY_MFPC;
197	if (sm->mfp == 2)
198		capab |= WPA_CAPABILITY_MFPR;
199#endif /* CONFIG_IEEE80211W */
200	WPA_PUT_LE16(pos, capab);
201	pos += 2;
202
203	if (sm->cur_pmksa) {
204		/* PMKID Count (2 octets, little endian) */
205		*pos++ = 1;
206		*pos++ = 0;
207		/* PMKID */
208		os_memcpy(pos, sm->cur_pmksa->pmkid, PMKID_LEN);
209		pos += PMKID_LEN;
210	}
211
212#ifdef CONFIG_IEEE80211W
213	if (mgmt_group_cipher == WPA_CIPHER_AES_128_CMAC) {
214		if (!sm->cur_pmksa) {
215			/* PMKID Count */
216			WPA_PUT_LE16(pos, 0);
217			pos += 2;
218		}
219
220		/* Management Group Cipher Suite */
221		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_AES_128_CMAC);
222		pos += RSN_SELECTOR_LEN;
223	}
224#endif /* CONFIG_IEEE80211W */
225
226	hdr->len = (pos - rsn_ie) - 2;
227
228	WPA_ASSERT((size_t) (pos - rsn_ie) <= rsn_ie_len);
229
230	return pos - rsn_ie;
231#else /* CONFIG_NO_WPA2 */
232	return -1;
233#endif /* CONFIG_NO_WPA2 */
234}
235
236
237/**
238 * wpa_gen_wpa_ie - Generate WPA/RSN IE based on current security policy
239 * @sm: Pointer to WPA state machine data from wpa_sm_init()
240 * @wpa_ie: Pointer to memory area for the generated WPA/RSN IE
241 * @wpa_ie_len: Maximum length of the generated WPA/RSN IE
242 * Returns: Length of the generated WPA/RSN IE or -1 on failure
243 */
244int wpa_gen_wpa_ie(struct wpa_sm *sm, u8 *wpa_ie, size_t wpa_ie_len)
245{
246	if (sm->proto == WPA_PROTO_RSN)
247		return wpa_gen_wpa_ie_rsn(wpa_ie, wpa_ie_len,
248					  sm->pairwise_cipher,
249					  sm->group_cipher,
250					  sm->key_mgmt, sm->mgmt_group_cipher,
251					  sm);
252	else
253		return wpa_gen_wpa_ie_wpa(wpa_ie, wpa_ie_len,
254					  sm->pairwise_cipher,
255					  sm->group_cipher,
256					  sm->key_mgmt);
257}
258
259
260/**
261 * wpa_parse_generic - Parse EAPOL-Key Key Data Generic IEs
262 * @pos: Pointer to the IE header
263 * @end: Pointer to the end of the Key Data buffer
264 * @ie: Pointer to parsed IE data
265 * Returns: 0 on success, 1 if end mark is found, -1 on failure
266 */
267static int wpa_parse_generic(const u8 *pos, const u8 *end,
268			     struct wpa_eapol_ie_parse *ie)
269{
270	if (pos[1] == 0)
271		return 1;
272
273	if (pos[1] >= 6 &&
274	    RSN_SELECTOR_GET(pos + 2) == WPA_OUI_TYPE &&
275	    pos[2 + WPA_SELECTOR_LEN] == 1 &&
276	    pos[2 + WPA_SELECTOR_LEN + 1] == 0) {
277		ie->wpa_ie = pos;
278		ie->wpa_ie_len = pos[1] + 2;
279		wpa_hexdump(MSG_DEBUG, "WPA: WPA IE in EAPOL-Key",
280			    ie->wpa_ie, ie->wpa_ie_len);
281		return 0;
282	}
283
284	if (pos + 1 + RSN_SELECTOR_LEN < end &&
285	    pos[1] >= RSN_SELECTOR_LEN + PMKID_LEN &&
286	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_PMKID) {
287		ie->pmkid = pos + 2 + RSN_SELECTOR_LEN;
288		wpa_hexdump(MSG_DEBUG, "WPA: PMKID in EAPOL-Key",
289			    pos, pos[1] + 2);
290		return 0;
291	}
292
293	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
294	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_GROUPKEY) {
295		ie->gtk = pos + 2 + RSN_SELECTOR_LEN;
296		ie->gtk_len = pos[1] - RSN_SELECTOR_LEN;
297		wpa_hexdump_key(MSG_DEBUG, "WPA: GTK in EAPOL-Key",
298				pos, pos[1] + 2);
299		return 0;
300	}
301
302	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
303	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_MAC_ADDR) {
304		ie->mac_addr = pos + 2 + RSN_SELECTOR_LEN;
305		ie->mac_addr_len = pos[1] - RSN_SELECTOR_LEN;
306		wpa_hexdump(MSG_DEBUG, "WPA: MAC Address in EAPOL-Key",
307			    pos, pos[1] + 2);
308		return 0;
309	}
310
311#ifdef CONFIG_PEERKEY
312	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
313	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_SMK) {
314		ie->smk = pos + 2 + RSN_SELECTOR_LEN;
315		ie->smk_len = pos[1] - RSN_SELECTOR_LEN;
316		wpa_hexdump_key(MSG_DEBUG, "WPA: SMK 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_NONCE) {
323		ie->nonce = pos + 2 + RSN_SELECTOR_LEN;
324		ie->nonce_len = pos[1] - RSN_SELECTOR_LEN;
325		wpa_hexdump(MSG_DEBUG, "WPA: Nonce in EAPOL-Key",
326			    pos, pos[1] + 2);
327		return 0;
328	}
329
330	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
331	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_LIFETIME) {
332		ie->lifetime = pos + 2 + RSN_SELECTOR_LEN;
333		ie->lifetime_len = pos[1] - RSN_SELECTOR_LEN;
334		wpa_hexdump(MSG_DEBUG, "WPA: Lifetime in EAPOL-Key",
335			    pos, pos[1] + 2);
336		return 0;
337	}
338
339	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
340	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_ERROR) {
341		ie->error = pos + 2 + RSN_SELECTOR_LEN;
342		ie->error_len = pos[1] - RSN_SELECTOR_LEN;
343		wpa_hexdump(MSG_DEBUG, "WPA: Error in EAPOL-Key",
344			    pos, pos[1] + 2);
345		return 0;
346	}
347#endif /* CONFIG_PEERKEY */
348
349#ifdef CONFIG_IEEE80211W
350	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
351	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_IGTK) {
352		ie->igtk = pos + 2 + RSN_SELECTOR_LEN;
353		ie->igtk_len = pos[1] - RSN_SELECTOR_LEN;
354		wpa_hexdump_key(MSG_DEBUG, "WPA: IGTK in EAPOL-Key",
355				pos, pos[1] + 2);
356		return 0;
357	}
358#endif /* CONFIG_IEEE80211W */
359
360	return 0;
361}
362
363
364/**
365 * wpa_supplicant_parse_ies - Parse EAPOL-Key Key Data IEs
366 * @buf: Pointer to the Key Data buffer
367 * @len: Key Data Length
368 * @ie: Pointer to parsed IE data
369 * Returns: 0 on success, -1 on failure
370 */
371int wpa_supplicant_parse_ies(const u8 *buf, size_t len,
372			     struct wpa_eapol_ie_parse *ie)
373{
374	const u8 *pos, *end;
375	int ret = 0;
376
377	os_memset(ie, 0, sizeof(*ie));
378	for (pos = buf, end = pos + len; pos + 1 < end; pos += 2 + pos[1]) {
379		if (pos[0] == 0xdd &&
380		    ((pos == buf + len - 1) || pos[1] == 0)) {
381			/* Ignore padding */
382			break;
383		}
384		if (pos + 2 + pos[1] > end) {
385			wpa_printf(MSG_DEBUG, "WPA: EAPOL-Key Key Data "
386				   "underflow (ie=%d len=%d pos=%d)",
387				   pos[0], pos[1], (int) (pos - buf));
388			wpa_hexdump_key(MSG_DEBUG, "WPA: Key Data",
389					buf, len);
390			ret = -1;
391			break;
392		}
393		if (*pos == WLAN_EID_RSN) {
394			ie->rsn_ie = pos;
395			ie->rsn_ie_len = pos[1] + 2;
396			wpa_hexdump(MSG_DEBUG, "WPA: RSN IE in EAPOL-Key",
397				    ie->rsn_ie, ie->rsn_ie_len);
398		} else if (*pos == WLAN_EID_MOBILITY_DOMAIN) {
399			ie->mdie = pos;
400			ie->mdie_len = pos[1] + 2;
401			wpa_hexdump(MSG_DEBUG, "WPA: MDIE in EAPOL-Key",
402				    ie->mdie, ie->mdie_len);
403		} else if (*pos == WLAN_EID_FAST_BSS_TRANSITION) {
404			ie->ftie = pos;
405			ie->ftie_len = pos[1] + 2;
406			wpa_hexdump(MSG_DEBUG, "WPA: FTIE in EAPOL-Key",
407				    ie->ftie, ie->ftie_len);
408		} else if (*pos == WLAN_EID_TIMEOUT_INTERVAL && pos[1] >= 5) {
409			if (pos[2] == WLAN_TIMEOUT_REASSOC_DEADLINE) {
410				ie->reassoc_deadline = pos;
411				wpa_hexdump(MSG_DEBUG, "WPA: Reassoc Deadline "
412					    "in EAPOL-Key",
413					    ie->reassoc_deadline, pos[1] + 2);
414			} else if (pos[2] == WLAN_TIMEOUT_KEY_LIFETIME) {
415				ie->key_lifetime = pos;
416				wpa_hexdump(MSG_DEBUG, "WPA: KeyLifetime "
417					    "in EAPOL-Key",
418					    ie->key_lifetime, pos[1] + 2);
419			} else {
420				wpa_hexdump(MSG_DEBUG, "WPA: Unrecognized "
421					    "EAPOL-Key Key Data IE",
422					    pos, 2 + pos[1]);
423			}
424		} else if (*pos == WLAN_EID_LINK_ID) {
425			if (pos[1] >= 18) {
426				ie->lnkid = pos;
427				ie->lnkid_len = pos[1] + 2;
428			}
429		} else if (*pos == WLAN_EID_EXT_CAPAB) {
430			ie->ext_capab = pos;
431			ie->ext_capab_len = pos[1] + 2;
432		} else if (*pos == WLAN_EID_SUPP_RATES) {
433			ie->supp_rates = pos;
434			ie->supp_rates_len = pos[1] + 2;
435		} else if (*pos == WLAN_EID_EXT_SUPP_RATES) {
436			ie->ext_supp_rates = pos;
437			ie->ext_supp_rates_len = pos[1] + 2;
438		} else if (*pos == WLAN_EID_VENDOR_SPECIFIC) {
439			ret = wpa_parse_generic(pos, end, ie);
440			if (ret < 0)
441				break;
442			if (ret > 0) {
443				ret = 0;
444				break;
445			}
446		} else {
447			wpa_hexdump(MSG_DEBUG, "WPA: Unrecognized EAPOL-Key "
448				    "Key Data IE", pos, 2 + pos[1]);
449		}
450	}
451
452	return ret;
453}
454