wpa_ie.c revision c5ec7f57ead87efa365800228aa0b09a12d9e6c4 
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_TKIP) {
136		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_TKIP);
137	} else if (group_cipher == WPA_CIPHER_WEP104) {
138		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_WEP104);
139	} else if (group_cipher == WPA_CIPHER_WEP40) {
140		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_WEP40);
141	} else {
142		wpa_printf(MSG_WARNING, "Invalid group cipher (%d).",
143			   group_cipher);
144		return -1;
145	}
146	pos += RSN_SELECTOR_LEN;
147
148	*pos++ = 1;
149	*pos++ = 0;
150	if (pairwise_cipher == WPA_CIPHER_CCMP) {
151		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
152	} else if (pairwise_cipher == WPA_CIPHER_TKIP) {
153		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_TKIP);
154	} else if (pairwise_cipher == WPA_CIPHER_NONE) {
155		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_NONE);
156	} else {
157		wpa_printf(MSG_WARNING, "Invalid pairwise cipher (%d).",
158			   pairwise_cipher);
159		return -1;
160	}
161	pos += RSN_SELECTOR_LEN;
162
163	*pos++ = 1;
164	*pos++ = 0;
165	if (key_mgmt == WPA_KEY_MGMT_IEEE8021X) {
166		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_UNSPEC_802_1X);
167	} else if (key_mgmt == WPA_KEY_MGMT_PSK) {
168		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_PSK_OVER_802_1X);
169#ifdef CONFIG_IEEE80211R
170	} else if (key_mgmt == WPA_KEY_MGMT_FT_IEEE8021X) {
171		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_FT_802_1X);
172	} else if (key_mgmt == WPA_KEY_MGMT_FT_PSK) {
173		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_FT_PSK);
174#endif /* CONFIG_IEEE80211R */
175#ifdef CONFIG_IEEE80211W
176	} else if (key_mgmt == WPA_KEY_MGMT_IEEE8021X_SHA256) {
177		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_802_1X_SHA256);
178	} else if (key_mgmt == WPA_KEY_MGMT_PSK_SHA256) {
179		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_PSK_SHA256);
180#endif /* CONFIG_IEEE80211W */
181	} else {
182		wpa_printf(MSG_WARNING, "Invalid key management type (%d).",
183			   key_mgmt);
184		return -1;
185	}
186	pos += RSN_SELECTOR_LEN;
187
188	/* RSN Capabilities */
189	capab = 0;
190#ifdef CONFIG_IEEE80211W
191	if (sm->mfp)
192		capab |= WPA_CAPABILITY_MFPC;
193	if (sm->mfp == 2)
194		capab |= WPA_CAPABILITY_MFPR;
195#endif /* CONFIG_IEEE80211W */
196	WPA_PUT_LE16(pos, capab);
197	pos += 2;
198
199	if (sm->cur_pmksa) {
200		/* PMKID Count (2 octets, little endian) */
201		*pos++ = 1;
202		*pos++ = 0;
203		/* PMKID */
204		os_memcpy(pos, sm->cur_pmksa->pmkid, PMKID_LEN);
205		pos += PMKID_LEN;
206	}
207
208#ifdef CONFIG_IEEE80211W
209	if (mgmt_group_cipher == WPA_CIPHER_AES_128_CMAC) {
210		if (!sm->cur_pmksa) {
211			/* PMKID Count */
212			WPA_PUT_LE16(pos, 0);
213			pos += 2;
214		}
215
216		/* Management Group Cipher Suite */
217		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_AES_128_CMAC);
218		pos += RSN_SELECTOR_LEN;
219	}
220#endif /* CONFIG_IEEE80211W */
221
222	hdr->len = (pos - rsn_ie) - 2;
223
224	WPA_ASSERT((size_t) (pos - rsn_ie) <= rsn_ie_len);
225
226	return pos - rsn_ie;
227#else /* CONFIG_NO_WPA2 */
228	return -1;
229#endif /* CONFIG_NO_WPA2 */
230}
231
232
233/**
234 * wpa_gen_wpa_ie - Generate WPA/RSN IE based on current security policy
235 * @sm: Pointer to WPA state machine data from wpa_sm_init()
236 * @wpa_ie: Pointer to memory area for the generated WPA/RSN IE
237 * @wpa_ie_len: Maximum length of the generated WPA/RSN IE
238 * Returns: Length of the generated WPA/RSN IE or -1 on failure
239 */
240int wpa_gen_wpa_ie(struct wpa_sm *sm, u8 *wpa_ie, size_t wpa_ie_len)
241{
242	if (sm->proto == WPA_PROTO_RSN)
243		return wpa_gen_wpa_ie_rsn(wpa_ie, wpa_ie_len,
244					  sm->pairwise_cipher,
245					  sm->group_cipher,
246					  sm->key_mgmt, sm->mgmt_group_cipher,
247					  sm);
248	else
249		return wpa_gen_wpa_ie_wpa(wpa_ie, wpa_ie_len,
250					  sm->pairwise_cipher,
251					  sm->group_cipher,
252					  sm->key_mgmt);
253}
254
255
256/**
257 * wpa_parse_generic - Parse EAPOL-Key Key Data Generic IEs
258 * @pos: Pointer to the IE header
259 * @end: Pointer to the end of the Key Data buffer
260 * @ie: Pointer to parsed IE data
261 * Returns: 0 on success, 1 if end mark is found, -1 on failure
262 */
263static int wpa_parse_generic(const u8 *pos, const u8 *end,
264			     struct wpa_eapol_ie_parse *ie)
265{
266	if (pos[1] == 0)
267		return 1;
268
269	if (pos[1] >= 6 &&
270	    RSN_SELECTOR_GET(pos + 2) == WPA_OUI_TYPE &&
271	    pos[2 + WPA_SELECTOR_LEN] == 1 &&
272	    pos[2 + WPA_SELECTOR_LEN + 1] == 0) {
273		ie->wpa_ie = pos;
274		ie->wpa_ie_len = pos[1] + 2;
275		wpa_hexdump(MSG_DEBUG, "WPA: WPA IE in EAPOL-Key",
276			    ie->wpa_ie, ie->wpa_ie_len);
277		return 0;
278	}
279
280	if (pos + 1 + RSN_SELECTOR_LEN < end &&
281	    pos[1] >= RSN_SELECTOR_LEN + PMKID_LEN &&
282	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_PMKID) {
283		ie->pmkid = pos + 2 + RSN_SELECTOR_LEN;
284		wpa_hexdump(MSG_DEBUG, "WPA: PMKID in EAPOL-Key",
285			    pos, pos[1] + 2);
286		return 0;
287	}
288
289	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
290	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_GROUPKEY) {
291		ie->gtk = pos + 2 + RSN_SELECTOR_LEN;
292		ie->gtk_len = pos[1] - RSN_SELECTOR_LEN;
293		wpa_hexdump_key(MSG_DEBUG, "WPA: GTK in EAPOL-Key",
294				pos, pos[1] + 2);
295		return 0;
296	}
297
298	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
299	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_MAC_ADDR) {
300		ie->mac_addr = pos + 2 + RSN_SELECTOR_LEN;
301		ie->mac_addr_len = pos[1] - RSN_SELECTOR_LEN;
302		wpa_hexdump(MSG_DEBUG, "WPA: MAC Address in EAPOL-Key",
303			    pos, pos[1] + 2);
304		return 0;
305	}
306
307#ifdef CONFIG_PEERKEY
308	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
309	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_SMK) {
310		ie->smk = pos + 2 + RSN_SELECTOR_LEN;
311		ie->smk_len = pos[1] - RSN_SELECTOR_LEN;
312		wpa_hexdump_key(MSG_DEBUG, "WPA: SMK in EAPOL-Key",
313				pos, pos[1] + 2);
314		return 0;
315	}
316
317	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
318	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_NONCE) {
319		ie->nonce = pos + 2 + RSN_SELECTOR_LEN;
320		ie->nonce_len = pos[1] - RSN_SELECTOR_LEN;
321		wpa_hexdump(MSG_DEBUG, "WPA: Nonce in EAPOL-Key",
322			    pos, pos[1] + 2);
323		return 0;
324	}
325
326	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
327	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_LIFETIME) {
328		ie->lifetime = pos + 2 + RSN_SELECTOR_LEN;
329		ie->lifetime_len = pos[1] - RSN_SELECTOR_LEN;
330		wpa_hexdump(MSG_DEBUG, "WPA: Lifetime in EAPOL-Key",
331			    pos, pos[1] + 2);
332		return 0;
333	}
334
335	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
336	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_ERROR) {
337		ie->error = pos + 2 + RSN_SELECTOR_LEN;
338		ie->error_len = pos[1] - RSN_SELECTOR_LEN;
339		wpa_hexdump(MSG_DEBUG, "WPA: Error in EAPOL-Key",
340			    pos, pos[1] + 2);
341		return 0;
342	}
343#endif /* CONFIG_PEERKEY */
344
345#ifdef CONFIG_IEEE80211W
346	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
347	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_IGTK) {
348		ie->igtk = pos + 2 + RSN_SELECTOR_LEN;
349		ie->igtk_len = pos[1] - RSN_SELECTOR_LEN;
350		wpa_hexdump_key(MSG_DEBUG, "WPA: IGTK in EAPOL-Key",
351				pos, pos[1] + 2);
352		return 0;
353	}
354#endif /* CONFIG_IEEE80211W */
355
356	return 0;
357}
358
359
360/**
361 * wpa_supplicant_parse_ies - Parse EAPOL-Key Key Data IEs
362 * @buf: Pointer to the Key Data buffer
363 * @len: Key Data Length
364 * @ie: Pointer to parsed IE data
365 * Returns: 0 on success, -1 on failure
366 */
367int wpa_supplicant_parse_ies(const u8 *buf, size_t len,
368			     struct wpa_eapol_ie_parse *ie)
369{
370	const u8 *pos, *end;
371	int ret = 0;
372
373	os_memset(ie, 0, sizeof(*ie));
374	for (pos = buf, end = pos + len; pos + 1 < end; pos += 2 + pos[1]) {
375		if (pos[0] == 0xdd &&
376		    ((pos == buf + len - 1) || pos[1] == 0)) {
377			/* Ignore padding */
378			break;
379		}
380		if (pos + 2 + pos[1] > end) {
381			wpa_printf(MSG_DEBUG, "WPA: EAPOL-Key Key Data "
382				   "underflow (ie=%d len=%d pos=%d)",
383				   pos[0], pos[1], (int) (pos - buf));
384			wpa_hexdump_key(MSG_DEBUG, "WPA: Key Data",
385					buf, len);
386			ret = -1;
387			break;
388		}
389		if (*pos == WLAN_EID_RSN) {
390			ie->rsn_ie = pos;
391			ie->rsn_ie_len = pos[1] + 2;
392			wpa_hexdump(MSG_DEBUG, "WPA: RSN IE in EAPOL-Key",
393				    ie->rsn_ie, ie->rsn_ie_len);
394		} else if (*pos == WLAN_EID_MOBILITY_DOMAIN) {
395			ie->mdie = pos;
396			ie->mdie_len = pos[1] + 2;
397			wpa_hexdump(MSG_DEBUG, "WPA: MDIE in EAPOL-Key",
398				    ie->mdie, ie->mdie_len);
399		} else if (*pos == WLAN_EID_FAST_BSS_TRANSITION) {
400			ie->ftie = pos;
401			ie->ftie_len = pos[1] + 2;
402			wpa_hexdump(MSG_DEBUG, "WPA: FTIE in EAPOL-Key",
403				    ie->ftie, ie->ftie_len);
404		} else if (*pos == WLAN_EID_TIMEOUT_INTERVAL && pos[1] >= 5) {
405			if (pos[2] == WLAN_TIMEOUT_REASSOC_DEADLINE) {
406				ie->reassoc_deadline = pos;
407				wpa_hexdump(MSG_DEBUG, "WPA: Reassoc Deadline "
408					    "in EAPOL-Key",
409					    ie->reassoc_deadline, pos[1] + 2);
410			} else if (pos[2] == WLAN_TIMEOUT_KEY_LIFETIME) {
411				ie->key_lifetime = pos;
412				wpa_hexdump(MSG_DEBUG, "WPA: KeyLifetime "
413					    "in EAPOL-Key",
414					    ie->key_lifetime, pos[1] + 2);
415			} else {
416				wpa_hexdump(MSG_DEBUG, "WPA: Unrecognized "
417					    "EAPOL-Key Key Data IE",
418					    pos, 2 + pos[1]);
419			}
420		} else if (*pos == WLAN_EID_LINK_ID) {
421			if (pos[1] >= 18) {
422				ie->lnkid = pos;
423				ie->lnkid_len = pos[1] + 2;
424			}
425		} else if (*pos == WLAN_EID_EXT_CAPAB) {
426			ie->ext_capab = pos;
427			ie->ext_capab_len = pos[1] + 2;
428		} else if (*pos == WLAN_EID_SUPP_RATES) {
429			ie->supp_rates = pos;
430			ie->supp_rates_len = pos[1] + 2;
431		} else if (*pos == WLAN_EID_EXT_SUPP_RATES) {
432			ie->ext_supp_rates = pos;
433			ie->ext_supp_rates_len = pos[1] + 2;
434		} else if (*pos == WLAN_EID_VENDOR_SPECIFIC) {
435			ret = wpa_parse_generic(pos, end, ie);
436			if (ret < 0)
437				break;
438			if (ret > 0) {
439				ret = 0;
440				break;
441			}
442		} else {
443			wpa_hexdump(MSG_DEBUG, "WPA: Unrecognized EAPOL-Key "
444				    "Key Data IE", pos, 2 + pos[1]);
445		}
446	}
447
448	return ret;
449}
450