xref: /freebsd/contrib/wpa/wpa_supplicant/wpas_kay.c (revision 9db3eed934f5ddc3c7a9ad4b831c78b3e789637e)
1 /*
2  * IEEE 802.1X-2010 KaY Interface
3  * Copyright (c) 2013-2014, Qualcomm Atheros, Inc.
4  *
5  * This software may be distributed under the terms of the BSD license.
6  * See README for more details.
7  */
8 #include <openssl/ssl.h>
9 #include "utils/includes.h"
10 
11 #include "utils/common.h"
12 #include "eap_peer/eap.h"
13 #include "eap_peer/eap_i.h"
14 #include "eapol_supp/eapol_supp_sm.h"
15 #include "pae/ieee802_1x_key.h"
16 #include "pae/ieee802_1x_kay.h"
17 #include "wpa_supplicant_i.h"
18 #include "config.h"
19 #include "config_ssid.h"
20 #include "driver_i.h"
21 #include "wpas_kay.h"
22 
23 
24 #define DEFAULT_KEY_LEN		16
25 /* secure Connectivity Association Key Name (CKN) */
26 #define DEFAULT_CKN_LEN		16
27 
28 
29 static int wpas_macsec_init(void *priv, struct macsec_init_params *params)
30 {
31 	return wpa_drv_macsec_init(priv, params);
32 }
33 
34 
35 static int wpas_macsec_deinit(void *priv)
36 {
37 	return wpa_drv_macsec_deinit(priv);
38 }
39 
40 
41 static int wpas_enable_protect_frames(void *wpa_s, Boolean enabled)
42 {
43 	return wpa_drv_enable_protect_frames(wpa_s, enabled);
44 }
45 
46 
47 static int wpas_set_replay_protect(void *wpa_s, Boolean enabled, u32 window)
48 {
49 	return wpa_drv_set_replay_protect(wpa_s, enabled, window);
50 }
51 
52 
53 static int wpas_set_current_cipher_suite(void *wpa_s, u64 cs)
54 {
55 	return wpa_drv_set_current_cipher_suite(wpa_s, cs);
56 }
57 
58 
59 static int wpas_enable_controlled_port(void *wpa_s, Boolean enabled)
60 {
61 	return wpa_drv_enable_controlled_port(wpa_s, enabled);
62 }
63 
64 
65 static int wpas_get_receive_lowest_pn(void *wpa_s, u32 channel,
66 				      u8 an, u32 *lowest_pn)
67 {
68 	return wpa_drv_get_receive_lowest_pn(wpa_s, channel, an, lowest_pn);
69 }
70 
71 
72 static int wpas_get_transmit_next_pn(void *wpa_s, u32 channel,
73 				      u8 an, u32 *next_pn)
74 {
75 	return wpa_drv_get_transmit_next_pn(wpa_s, channel, an, next_pn);
76 }
77 
78 
79 static int wpas_set_transmit_next_pn(void *wpa_s, u32 channel,
80 				      u8 an, u32 next_pn)
81 {
82 	return wpa_drv_set_transmit_next_pn(wpa_s, channel, an, next_pn);
83 }
84 
85 
86 static int wpas_get_available_receive_sc(void *wpa_s, u32 *channel)
87 {
88 	return wpa_drv_get_available_receive_sc(wpa_s, channel);
89 }
90 
91 
92 static unsigned int conf_offset_val(enum confidentiality_offset co)
93 {
94 	switch (co) {
95 	case CONFIDENTIALITY_OFFSET_30:
96 		return 30;
97 		break;
98 	case CONFIDENTIALITY_OFFSET_50:
99 		return 50;
100 	default:
101 		return 0;
102 	}
103 }
104 
105 
106 static int wpas_create_receive_sc(void *wpa_s, u32 channel,
107 				  struct ieee802_1x_mka_sci *sci,
108 				  enum validate_frames vf,
109 				  enum confidentiality_offset co)
110 {
111 	return wpa_drv_create_receive_sc(wpa_s, channel, sci->addr,
112 					 be_to_host16(sci->port),
113 					 conf_offset_val(co), vf);
114 }
115 
116 
117 static int wpas_delete_receive_sc(void *wpa_s, u32 channel)
118 {
119 	return wpa_drv_delete_receive_sc(wpa_s, channel);
120 }
121 
122 
123 static int wpas_create_receive_sa(void *wpa_s, u32 channel, u8 an,
124 				  u32 lowest_pn, const u8 *sak)
125 {
126 	return wpa_drv_create_receive_sa(wpa_s, channel, an, lowest_pn, sak);
127 }
128 
129 
130 static int wpas_enable_receive_sa(void *wpa_s, u32 channel, u8 an)
131 {
132 	return wpa_drv_enable_receive_sa(wpa_s, channel, an);
133 }
134 
135 
136 static int wpas_disable_receive_sa(void *wpa_s, u32 channel, u8 an)
137 {
138 	return wpa_drv_disable_receive_sa(wpa_s, channel, an);
139 }
140 
141 
142 static int wpas_get_available_transmit_sc(void *wpa_s, u32 *channel)
143 {
144 	return wpa_drv_get_available_transmit_sc(wpa_s, channel);
145 }
146 
147 
148 static int
149 wpas_create_transmit_sc(void *wpa_s, u32 channel,
150 			const struct ieee802_1x_mka_sci *sci,
151 			enum confidentiality_offset co)
152 {
153 	return wpa_drv_create_transmit_sc(wpa_s, channel, sci->addr,
154 					  be_to_host16(sci->port),
155 					  conf_offset_val(co));
156 }
157 
158 
159 static int wpas_delete_transmit_sc(void *wpa_s, u32 channel)
160 {
161 	return wpa_drv_delete_transmit_sc(wpa_s, channel);
162 }
163 
164 
165 static int wpas_create_transmit_sa(void *wpa_s, u32 channel, u8 an,
166 				   u32 next_pn, Boolean confidentiality,
167 				   const u8 *sak)
168 {
169 	return wpa_drv_create_transmit_sa(wpa_s, channel, an, next_pn,
170 					  confidentiality, sak);
171 }
172 
173 
174 static int wpas_enable_transmit_sa(void *wpa_s, u32 channel, u8 an)
175 {
176 	return wpa_drv_enable_transmit_sa(wpa_s, channel, an);
177 }
178 
179 
180 static int wpas_disable_transmit_sa(void *wpa_s, u32 channel, u8 an)
181 {
182 	return wpa_drv_disable_transmit_sa(wpa_s, channel, an);
183 }
184 
185 
186 int ieee802_1x_alloc_kay_sm(struct wpa_supplicant *wpa_s, struct wpa_ssid *ssid)
187 {
188 	struct ieee802_1x_kay_ctx *kay_ctx;
189 	struct ieee802_1x_kay *res = NULL;
190 	enum macsec_policy policy;
191 
192 	ieee802_1x_dealloc_kay_sm(wpa_s);
193 
194 	if (!ssid || ssid->macsec_policy == 0)
195 		return 0;
196 
197 	policy = ssid->macsec_policy == 1 ? SHOULD_SECURE : DO_NOT_SECURE;
198 
199 	kay_ctx = os_zalloc(sizeof(*kay_ctx));
200 	if (!kay_ctx)
201 		return -1;
202 
203 	kay_ctx->ctx = wpa_s;
204 
205 	kay_ctx->macsec_init = wpas_macsec_init;
206 	kay_ctx->macsec_deinit = wpas_macsec_deinit;
207 	kay_ctx->enable_protect_frames = wpas_enable_protect_frames;
208 	kay_ctx->set_replay_protect = wpas_set_replay_protect;
209 	kay_ctx->set_current_cipher_suite = wpas_set_current_cipher_suite;
210 	kay_ctx->enable_controlled_port = wpas_enable_controlled_port;
211 	kay_ctx->get_receive_lowest_pn = wpas_get_receive_lowest_pn;
212 	kay_ctx->get_transmit_next_pn = wpas_get_transmit_next_pn;
213 	kay_ctx->set_transmit_next_pn = wpas_set_transmit_next_pn;
214 	kay_ctx->get_available_receive_sc = wpas_get_available_receive_sc;
215 	kay_ctx->create_receive_sc = wpas_create_receive_sc;
216 	kay_ctx->delete_receive_sc = wpas_delete_receive_sc;
217 	kay_ctx->create_receive_sa = wpas_create_receive_sa;
218 	kay_ctx->enable_receive_sa = wpas_enable_receive_sa;
219 	kay_ctx->disable_receive_sa = wpas_disable_receive_sa;
220 	kay_ctx->get_available_transmit_sc = wpas_get_available_transmit_sc;
221 	kay_ctx->create_transmit_sc = wpas_create_transmit_sc;
222 	kay_ctx->delete_transmit_sc = wpas_delete_transmit_sc;
223 	kay_ctx->create_transmit_sa = wpas_create_transmit_sa;
224 	kay_ctx->enable_transmit_sa = wpas_enable_transmit_sa;
225 	kay_ctx->disable_transmit_sa = wpas_disable_transmit_sa;
226 
227 	res = ieee802_1x_kay_init(kay_ctx, policy, wpa_s->ifname,
228 				  wpa_s->own_addr);
229 	if (res == NULL) {
230 		os_free(kay_ctx);
231 		return -1;
232 	}
233 
234 	wpa_s->kay = res;
235 
236 	return 0;
237 }
238 
239 
240 void ieee802_1x_dealloc_kay_sm(struct wpa_supplicant *wpa_s)
241 {
242 	if (!wpa_s->kay)
243 		return;
244 
245 	ieee802_1x_kay_deinit(wpa_s->kay);
246 	wpa_s->kay = NULL;
247 }
248 
249 
250 static int ieee802_1x_auth_get_session_id(struct wpa_supplicant *wpa_s,
251 					  const u8 *addr, u8 *sid, size_t *len)
252 {
253 	const u8 *session_id;
254 	size_t id_len, need_len;
255 
256 	session_id = eapol_sm_get_session_id(wpa_s->eapol, &id_len);
257 	if (session_id == NULL) {
258 		wpa_printf(MSG_DEBUG,
259 			   "Failed to get SessionID from EAPOL state machines");
260 		return -1;
261 	}
262 
263 	need_len = 1 + 2 * SSL3_RANDOM_SIZE;
264 	if (need_len > id_len) {
265 		wpa_printf(MSG_DEBUG, "EAP Session-Id not long enough");
266 		return -1;
267 	}
268 
269 	os_memcpy(sid, session_id, need_len);
270 	*len = need_len;
271 
272 	return 0;
273 }
274 
275 
276 static int ieee802_1x_auth_get_msk(struct wpa_supplicant *wpa_s, const u8 *addr,
277 				   u8 *msk, size_t *len)
278 {
279 	u8 key[EAP_MSK_LEN];
280 	size_t keylen;
281 	struct eapol_sm *sm;
282 	int res;
283 
284 	sm = wpa_s->eapol;
285 	if (sm == NULL)
286 		return -1;
287 
288 	keylen = EAP_MSK_LEN;
289 	res = eapol_sm_get_key(sm, key, keylen);
290 	if (res) {
291 		wpa_printf(MSG_DEBUG,
292 			   "Failed to get MSK from EAPOL state machines");
293 		return -1;
294 	}
295 
296 	if (keylen > *len)
297 		keylen = *len;
298 	os_memcpy(msk, key, keylen);
299 	*len = keylen;
300 
301 	return 0;
302 }
303 
304 
305 void * ieee802_1x_notify_create_actor(struct wpa_supplicant *wpa_s,
306 				      const u8 *peer_addr)
307 {
308 	u8 *sid;
309 	size_t sid_len = 128;
310 	struct mka_key_name *ckn;
311 	struct mka_key *cak;
312 	struct mka_key *msk;
313 	void *res = NULL;
314 
315 	if (!wpa_s->kay || wpa_s->kay->policy == DO_NOT_SECURE)
316 		return NULL;
317 
318 	wpa_printf(MSG_DEBUG,
319 		   "IEEE 802.1X: External notification - Create MKA for "
320 		   MACSTR, MAC2STR(peer_addr));
321 
322 	msk = os_zalloc(sizeof(*msk));
323 	sid = os_zalloc(sid_len);
324 	ckn = os_zalloc(sizeof(*ckn));
325 	cak = os_zalloc(sizeof(*cak));
326 	if (!msk || !sid || !ckn || !cak)
327 		goto fail;
328 
329 	msk->len = DEFAULT_KEY_LEN;
330 	if (ieee802_1x_auth_get_msk(wpa_s, wpa_s->bssid, msk->key, &msk->len)) {
331 		wpa_printf(MSG_ERROR, "IEEE 802.1X: Could not get MSK");
332 		goto fail;
333 	}
334 
335 	if (ieee802_1x_auth_get_session_id(wpa_s, wpa_s->bssid, sid, &sid_len))
336 	{
337 		wpa_printf(MSG_ERROR,
338 			   "IEEE 802.1X: Could not get EAP Session Id");
339 		goto fail;
340 	}
341 
342 	/* Derive CAK from MSK */
343 	cak->len = DEFAULT_KEY_LEN;
344 	if (ieee802_1x_cak_128bits_aes_cmac(msk->key, wpa_s->own_addr,
345 					    peer_addr, cak->key)) {
346 		wpa_printf(MSG_ERROR,
347 			   "IEEE 802.1X: Deriving CAK failed");
348 		goto fail;
349 	}
350 	wpa_hexdump_key(MSG_DEBUG, "Derived CAK", cak->key, cak->len);
351 
352 	/* Derive CKN from MSK */
353 	ckn->len = DEFAULT_CKN_LEN;
354 	if (ieee802_1x_ckn_128bits_aes_cmac(msk->key, wpa_s->own_addr,
355 					    peer_addr, sid, sid_len,
356 					    ckn->name)) {
357 		wpa_printf(MSG_ERROR,
358 			   "IEEE 802.1X: Deriving CKN failed");
359 		goto fail;
360 	}
361 	wpa_hexdump(MSG_DEBUG, "Derived CKN", ckn->name, ckn->len);
362 
363 	res = ieee802_1x_kay_create_mka(wpa_s->kay, ckn, cak, 0,
364 					EAP_EXCHANGE, FALSE);
365 
366 fail:
367 	if (msk) {
368 		os_memset(msk, 0, sizeof(*msk));
369 		os_free(msk);
370 	}
371 	os_free(sid);
372 	os_free(ckn);
373 	if (cak) {
374 		os_memset(cak, 0, sizeof(*cak));
375 		os_free(cak);
376 	}
377 
378 	return res;
379 }
380