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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  */
wpa_parse_wpa_ie(const u8 * wpa_ie,size_t wpa_ie_len,struct wpa_ie_data * data)28 int 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 
wpa_gen_wpa_ie_wpa(u8 * wpa_ie,size_t wpa_ie_len,int pairwise_cipher,int group_cipher,int key_mgmt)38 static 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 
wpa_gen_wpa_ie_rsn(u8 * rsn_ie,size_t rsn_ie_len,int pairwise_cipher,int group_cipher,int key_mgmt,int mgmt_group_cipher,struct wpa_sm * sm)110 static 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  */
wpa_gen_wpa_ie(struct wpa_sm * sm,u8 * wpa_ie,size_t wpa_ie_len)240 int 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  */
wpa_parse_generic(const u8 * pos,const u8 * end,struct wpa_eapol_ie_parse * ie)263 static 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  */
wpa_supplicant_parse_ies(const u8 * buf,size_t len,struct wpa_eapol_ie_parse * ie)367 int 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