1 /*
2 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
3 * Use is subject to license terms.
4 */
5
6 /*
7 * Copyright (c) 2001 Atsushi Onoe
8 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. The name of the author may not be used to endorse or promote products
20 * derived from this software without specific prior written permission.
21 *
22 * Alternatively, this software may be distributed under the terms of the
23 * GNU General Public License ("GPL") version 2 as published by the Free
24 * Software Foundation.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 */
37
38 #pragma ident "%Z%%M% %I% %E% SMI"
39
40 /*
41 * IEEE 802.11 generic crypto support
42 */
43 #include <sys/types.h>
44 #include <sys/note.h>
45 #include <sys/crypto/common.h>
46 #include <sys/crypto/api.h>
47 #include <sys/strsun.h>
48 #include "net80211_impl.h"
49
50 extern const struct ieee80211_cipher wep;
51 extern const struct ieee80211_cipher tkip;
52 extern const struct ieee80211_cipher ccmp;
53
54 /*
55 * Table of registered cipher modules.
56 */
57 static const char *cipher_modnames[] = {
58 "wlan_wep", /* IEEE80211_CIPHER_WEP */
59 "wlan_tkip", /* IEEE80211_CIPHER_TKIP */
60 "wlan_aes_ocb", /* IEEE80211_CIPHER_AES_OCB */
61 "wlan_ccmp", /* IEEE80211_CIPHER_AES_CCM */
62 "wlan_ckip", /* IEEE80211_CIPHER_CKIP */
63 };
64
65 /*
66 * Default "null" key management routines.
67 */
68 /* ARGSUSED */
69 static int
nulldev_key_alloc(ieee80211com_t * ic,const struct ieee80211_key * k,ieee80211_keyix * keyix,ieee80211_keyix * rxkeyix)70 nulldev_key_alloc(ieee80211com_t *ic, const struct ieee80211_key *k,
71 ieee80211_keyix *keyix, ieee80211_keyix *rxkeyix)
72 {
73 *keyix = 0; /* use key index 0 for ucast key */
74 *rxkeyix = IEEE80211_KEYIX_NONE;
75 return (1);
76 }
77
78 /* ARGSUSED */
79 static int
nulldev_key_delete(ieee80211com_t * ic,const struct ieee80211_key * k)80 nulldev_key_delete(ieee80211com_t *ic, const struct ieee80211_key *k)
81 {
82 return (1);
83 }
84
85 /* ARGSUSED */
86 static int
nulldev_key_set(ieee80211com_t * ic,const struct ieee80211_key * k,const uint8_t * mac)87 nulldev_key_set(ieee80211com_t *ic, const struct ieee80211_key *k,
88 const uint8_t *mac)
89 {
90 return (1);
91 }
92
93 /* ARGSUSED */
94 static void
nulldev_key_update(ieee80211com_t * ic)95 nulldev_key_update(ieee80211com_t *ic)
96 {
97 /* noop */
98 }
99
100 /*
101 * Reset key state to an unused state. The crypto
102 * key allocation mechanism insures other state (e.g.
103 * key data) is properly setup before a key is used.
104 */
105 void
ieee80211_crypto_resetkey(ieee80211com_t * ic,struct ieee80211_key * k,ieee80211_keyix ix)106 ieee80211_crypto_resetkey(ieee80211com_t *ic,
107 struct ieee80211_key *k, ieee80211_keyix ix)
108 {
109 k->wk_cipher = &ieee80211_cipher_none;
110 k->wk_private = k->wk_cipher->ic_attach(ic, k);
111 k->wk_keyix = ix;
112 k->wk_flags = IEEE80211_KEY_XMIT | IEEE80211_KEY_RECV;
113 }
114
115 /*
116 * Establish a relationship between the specified key and cipher
117 * and, if necessary, allocate a hardware index from the driver.
118 * Note that when a fixed key index is required it must be specified
119 * and we blindly assign it w/o consulting the driver.
120 *
121 * This must be the first call applied to a key; all the other key
122 * routines assume wk_cipher is setup.
123 *
124 * Locking must be handled by the caller using:
125 * ieee80211_key_update_begin(ic);
126 * ieee80211_key_update_end(ic);
127 */
128 int
ieee80211_crypto_newkey(ieee80211com_t * ic,int cipher,int flags,struct ieee80211_key * key)129 ieee80211_crypto_newkey(ieee80211com_t *ic, int cipher, int flags,
130 struct ieee80211_key *key)
131 {
132 const struct ieee80211_cipher *cip;
133 ieee80211_keyix keyix, rxkeyix;
134 void *keyctx;
135 uint16_t oflags;
136
137 /*
138 * Validate cipher and set reference to cipher routines.
139 */
140 if (cipher >= IEEE80211_CIPHER_MAX) {
141 ieee80211_dbg(IEEE80211_MSG_CRYPTO, "ieee80211_crypto_newkey: "
142 "invalid cipher %u\n", cipher);
143 return (0);
144 }
145 cip = ic->ic_ciphers[cipher];
146 /* already load all the ciphers, cip can't be NULL */
147 if (cip == NULL) {
148 ieee80211_dbg(IEEE80211_MSG_CRYPTO, "ieee80211_crypto_newkey: "
149 "unable to load cipher %u, module %s\n",
150 cipher, cipher < IEEE80211_N(cipher_modnames) ?
151 cipher_modnames[cipher] : "<unknown>");
152 return (0);
153 }
154
155 oflags = key->wk_flags;
156 flags &= IEEE80211_KEY_COMMON;
157 /*
158 * If the hardware does not support the cipher then
159 * fallback to a host-based implementation.
160 */
161 if ((ic->ic_caps & (1<<cipher)) == 0) {
162 ieee80211_dbg(IEEE80211_MSG_CRYPTO, "ieee80211_crypto_newkey: "
163 "no h/w support for cipher %s, falling back to s/w\n",
164 cip->ic_name);
165 flags |= IEEE80211_KEY_SWCRYPT;
166 }
167 /*
168 * Hardware TKIP with software MIC is an important
169 * combination; we handle it by flagging each key,
170 * the cipher modules honor it.
171 */
172 if (cipher == IEEE80211_CIPHER_TKIP &&
173 (ic->ic_caps & IEEE80211_C_TKIPMIC) == 0) {
174 ieee80211_dbg(IEEE80211_MSG_CRYPTO,
175 "no h/w support for TKIP MIC, falling back to s/w\n");
176 flags |= IEEE80211_KEY_SWMIC;
177 }
178
179 /*
180 * Bind cipher to key instance. Note we do this
181 * after checking the device capabilities so the
182 * cipher module can optimize space usage based on
183 * whether or not it needs to do the cipher work.
184 */
185 if (key->wk_cipher != cip || key->wk_flags != flags) {
186 again:
187 /*
188 * Fillin the flags so cipher modules can see s/w
189 * crypto requirements and potentially allocate
190 * different state and/or attach different method
191 * pointers.
192 */
193 key->wk_flags = (uint16_t)flags;
194 keyctx = cip->ic_attach(ic, key);
195 if (keyctx == NULL) {
196 ieee80211_dbg(IEEE80211_MSG_CRYPTO, "crypto_setkey: "
197 "unable to attach cipher %s\n", cip->ic_name);
198 key->wk_flags = oflags; /* restore old flags */
199 return (0);
200 }
201 CIPHER_DETACH(key); /* Detach old cipher */
202 key->wk_cipher = cip;
203 key->wk_private = keyctx;
204 }
205 /*
206 * Commit to requested usage so driver can see the flags.
207 */
208 key->wk_flags = (uint16_t)flags;
209
210 /*
211 * Ask the driver for a key index if we don't have one.
212 * Note that entries in the global key table always have
213 * an index; this means it's safe to call this routine
214 * for these entries just to setup the reference to the
215 * cipher template. Note also that when using software
216 * crypto we also call the driver to give us a key index.
217 */
218 if (key->wk_keyix == IEEE80211_KEYIX_NONE) {
219 if (!DEV_KEY_ALLOC(ic, key, &keyix, &rxkeyix)) {
220 /*
221 * Driver has no room; fallback to doing crypto
222 * in the host. We change the flags and start the
223 * procedure over. If we get back here then there's
224 * no hope and we bail. Note that this can leave
225 * the key in a inconsistent state if the caller
226 * continues to use it.
227 */
228 if ((key->wk_flags & IEEE80211_KEY_SWCRYPT) == 0) {
229 ieee80211_dbg(IEEE80211_MSG_CRYPTO,
230 "crypto_setkey: "
231 "no h/w resources for cipher %s, "
232 "falling back to s/w\n", cip->ic_name);
233 oflags = key->wk_flags;
234 flags |= IEEE80211_KEY_SWCRYPT;
235 if (cipher == IEEE80211_CIPHER_TKIP)
236 flags |= IEEE80211_KEY_SWMIC;
237 goto again;
238 }
239 ieee80211_dbg(IEEE80211_MSG_CRYPTO, "crypto_setkey: "
240 "unable to setup cipher %s\n", cip->ic_name);
241 return (0);
242 }
243 key->wk_keyix = keyix;
244 key->wk_rxkeyix = rxkeyix;
245 }
246 return (1);
247 }
248
249 /*
250 * Remove the key (no locking, for internal use).
251 */
252 static int
ieee80211_crypto_delkey_locked(ieee80211com_t * ic,struct ieee80211_key * key)253 ieee80211_crypto_delkey_locked(ieee80211com_t *ic, struct ieee80211_key *key)
254 {
255 uint16_t keyix;
256
257 ASSERT(key->wk_cipher != NULL);
258
259 keyix = key->wk_keyix;
260 if (keyix != IEEE80211_KEYIX_NONE) {
261 /*
262 * Remove hardware entry.
263 */
264 if (!DEV_KEY_DELETE(ic, key)) {
265 ieee80211_dbg(IEEE80211_MSG_CRYPTO,
266 "ieee80211_crypto_delkey_locked: ",
267 "driverdeletes key %u failed\n", keyix);
268 }
269 }
270 CIPHER_DETACH(key);
271 bzero(key, sizeof (struct ieee80211_key));
272 /* NB: cannot depend on key index to decide this */
273 ieee80211_crypto_resetkey(ic, key, IEEE80211_KEYIX_NONE);
274 return (1);
275 }
276
277 /*
278 * Remove the specified key.
279 */
280 int
ieee80211_crypto_delkey(ieee80211com_t * ic,struct ieee80211_key * key)281 ieee80211_crypto_delkey(ieee80211com_t *ic, struct ieee80211_key *key)
282 {
283 int status;
284
285 KEY_UPDATE_BEGIN(ic);
286 status = ieee80211_crypto_delkey_locked(ic, key);
287 KEY_UPDATE_END(ic);
288 return (status);
289 }
290
291 /*
292 * Clear the global key table.
293 */
294 static void
ieee80211_crypto_delglobalkeys(ieee80211com_t * ic)295 ieee80211_crypto_delglobalkeys(ieee80211com_t *ic)
296 {
297 int i;
298
299 KEY_UPDATE_BEGIN(ic);
300 for (i = 0; i < IEEE80211_WEP_NKID; i++)
301 (void) ieee80211_crypto_delkey_locked(ic, &ic->ic_nw_keys[i]);
302 KEY_UPDATE_END(ic);
303 }
304
305 /*
306 * Set the contents of the specified key.
307 *
308 * Locking must be handled by the caller using:
309 * ieee80211_key_update_begin(ic);
310 * ieee80211_key_update_end(ic);
311 */
312 int
ieee80211_crypto_setkey(ieee80211com_t * ic,struct ieee80211_key * key,const uint8_t * macaddr)313 ieee80211_crypto_setkey(ieee80211com_t *ic, struct ieee80211_key *key,
314 const uint8_t *macaddr)
315 {
316 const struct ieee80211_cipher *cip = key->wk_cipher;
317
318 ASSERT(cip != NULL);
319
320 ieee80211_dbg(IEEE80211_MSG_CRYPTO, "ieee80211_crypto_setkey: "
321 "%s keyix %u flags 0x%x mac %s len %u\n",
322 cip->ic_name, key->wk_keyix, key->wk_flags,
323 ieee80211_macaddr_sprintf(macaddr), key->wk_keylen);
324
325 /*
326 * Give cipher a chance to validate key contents.
327 * should happen before modifying state.
328 */
329 if (cip->ic_setkey(key) == 0) {
330 ieee80211_dbg(IEEE80211_MSG_CRYPTO, "ieee80211_crypto_setkey: "
331 "cipher %s rejected key index %u len %u flags 0x%x\n",
332 cip->ic_name, key->wk_keyix, key->wk_keylen,
333 key->wk_flags);
334 return (0);
335 }
336 if (key->wk_keyix == IEEE80211_KEYIX_NONE) {
337 ieee80211_dbg(IEEE80211_MSG_CRYPTO, "ieee80211_crypto_setkey: "
338 "no key index; should not happen!\n");
339 return (0);
340 }
341 return (DEV_KEY_SET(ic, key, macaddr));
342 }
343
344 /*
345 * Return the transmit key to use in sending a frame.
346 */
347 struct ieee80211_key *
ieee80211_crypto_getkey(ieee80211com_t * ic)348 ieee80211_crypto_getkey(ieee80211com_t *ic)
349 {
350 if (ic->ic_def_txkey == IEEE80211_KEYIX_NONE ||
351 KEY_UNDEFINED(ic->ic_nw_keys[ic->ic_def_txkey]))
352 return (NULL);
353 return (&ic->ic_nw_keys[ic->ic_def_txkey]);
354 }
355
356 uint8_t
ieee80211_crypto_getciphertype(ieee80211com_t * ic)357 ieee80211_crypto_getciphertype(ieee80211com_t *ic)
358 {
359 struct ieee80211_key *key;
360 uint32_t cipher;
361 static const uint8_t ciphermap[] = {
362 WIFI_SEC_WEP, /* IEEE80211_CIPHER_WEP */
363 WIFI_SEC_WPA, /* IEEE80211_CIPHER_TKIP */
364 (uint8_t)-1, /* IEEE80211_CIPHER_AES_OCB */
365 WIFI_SEC_WPA, /* IEEE80211_CIPHER_AES_CCM */
366 (uint8_t)-1, /* IEEE80211_CIPHER_CKIP */
367 WIFI_SEC_NONE, /* IEEE80211_CIPHER_NONE */
368 };
369
370 if ((ic->ic_flags & IEEE80211_F_PRIVACY) == 0)
371 return (WIFI_SEC_NONE);
372
373 key = ieee80211_crypto_getkey(ic);
374 if (key == NULL)
375 return (WIFI_SEC_NONE);
376
377 cipher = key->wk_cipher->ic_cipher;
378 ASSERT(cipher < IEEE80211_N(ciphermap));
379 return (ciphermap[cipher]);
380 }
381
382 /*
383 * Add privacy headers appropriate for the specified key.
384 */
385 struct ieee80211_key *
ieee80211_crypto_encap(ieee80211com_t * ic,mblk_t * mp)386 ieee80211_crypto_encap(ieee80211com_t *ic, mblk_t *mp)
387 {
388 struct ieee80211_key *k;
389 const struct ieee80211_cipher *cip;
390 uint8_t keyix;
391
392 if (ic->ic_def_txkey == IEEE80211_KEYIX_NONE) {
393 ieee80211_dbg(IEEE80211_MSG_CRYPTO,
394 "ieee80211_crypto_encap: %s",
395 " No default xmit key for frame\n");
396 return (NULL);
397 }
398 keyix = ic->ic_def_txkey;
399 k = &ic->ic_nw_keys[ic->ic_def_txkey];
400 cip = k->wk_cipher;
401 return (cip->ic_encap(k, mp, keyix<<6) ? k : NULL);
402 }
403
404 /*
405 * Validate and strip privacy headers (and trailer) for a
406 * received frame that has the WEP/Privacy bit set.
407 */
408 struct ieee80211_key *
ieee80211_crypto_decap(ieee80211com_t * ic,mblk_t * mp,int hdrlen)409 ieee80211_crypto_decap(ieee80211com_t *ic, mblk_t *mp, int hdrlen)
410 {
411 struct ieee80211_key *k;
412 const struct ieee80211_cipher *cip;
413 uint8_t *ivp;
414 uint8_t keyid;
415
416 /* NB: this minimum size data frame could be bigger */
417 if (MBLKL(mp) < IEEE80211_WEP_MINLEN) {
418 ieee80211_dbg(IEEE80211_MSG_CRYPTO, "ieee80211_crypto_decap:"
419 " WEP data frame too short, len %u\n",
420 MBLKL(mp));
421 return (NULL);
422 }
423 /*
424 * Locate the key. If unicast and there is no unicast
425 * key then we fall back to the key id in the header.
426 * This assumes unicast keys are only configured when
427 * the key id in the header is meaningless (typically 0).
428 */
429 ivp = mp->b_rptr + hdrlen;
430 keyid = ivp[IEEE80211_WEP_IVLEN];
431 k = &ic->ic_nw_keys[keyid >> 6];
432
433 /* check to avoid panic when wep is on but key is not set */
434 if (k->wk_cipher == &ieee80211_cipher_none ||
435 k->wk_cipher == NULL)
436 return (NULL);
437
438 cip = k->wk_cipher;
439 return ((cip->ic_decap)(k, mp, hdrlen) ? k : NULL);
440 }
441
442 /*
443 * Setup crypto support.
444 */
445 void
ieee80211_crypto_attach(ieee80211com_t * ic)446 ieee80211_crypto_attach(ieee80211com_t *ic)
447 {
448 struct ieee80211_crypto_state *cs = &ic->ic_crypto;
449 int i;
450
451 (void) crypto_mech2id(SUN_CKM_RC4); /* Load RC4 */
452 (void) crypto_mech2id(SUN_CKM_AES_CBC); /* Load AES-CBC */
453 (void) crypto_mech2id(SUN_CKM_AES_CCM); /* Load AES-CCM */
454
455 /* NB: we assume everything is pre-zero'd */
456 cs->cs_def_txkey = IEEE80211_KEYIX_NONE;
457 for (i = 0; i < IEEE80211_WEP_NKID; i++) {
458 ieee80211_crypto_resetkey(ic, &cs->cs_nw_keys[i],
459 IEEE80211_KEYIX_NONE);
460 }
461
462 /*
463 * Initialize the driver key support routines to noop entries.
464 * This is useful especially for the cipher test modules.
465 */
466 cs->cs_key_alloc = nulldev_key_alloc;
467 cs->cs_key_set = nulldev_key_set;
468 cs->cs_key_delete = nulldev_key_delete;
469 cs->cs_key_update_begin = nulldev_key_update;
470 cs->cs_key_update_end = nulldev_key_update;
471
472 ieee80211_crypto_register(ic, &wep);
473 ieee80211_crypto_register(ic, &tkip);
474 ieee80211_crypto_register(ic, &ccmp);
475 }
476
477 /*
478 * Teardown crypto support.
479 */
480 void
ieee80211_crypto_detach(ieee80211com_t * ic)481 ieee80211_crypto_detach(ieee80211com_t *ic)
482 {
483 ieee80211_crypto_delglobalkeys(ic);
484
485 ieee80211_crypto_unregister(ic, &wep);
486 ieee80211_crypto_unregister(ic, &tkip);
487 ieee80211_crypto_unregister(ic, &ccmp);
488 }
489
490 /*
491 * Register a crypto cipher module.
492 */
493 void
ieee80211_crypto_register(ieee80211com_t * ic,const struct ieee80211_cipher * cip)494 ieee80211_crypto_register(ieee80211com_t *ic,
495 const struct ieee80211_cipher *cip)
496 {
497 if (cip->ic_cipher >= IEEE80211_CIPHER_MAX) {
498 ieee80211_err("ieee80211_crypto_register: "
499 "cipher %s has an invalid cipher index %u\n",
500 cip->ic_name, cip->ic_cipher);
501 return;
502 }
503 if (ic->ic_ciphers[cip->ic_cipher] != NULL &&
504 ic->ic_ciphers[cip->ic_cipher] != cip) {
505 ieee80211_err("ieee80211_crypto_register: "
506 "cipher %s registered with a different template\n",
507 cip->ic_name);
508 return;
509 }
510 ic->ic_ciphers[cip->ic_cipher] = cip;
511 }
512
513 /*
514 * Unregister a crypto cipher module.
515 */
516 void
ieee80211_crypto_unregister(ieee80211com_t * ic,const struct ieee80211_cipher * cip)517 ieee80211_crypto_unregister(ieee80211com_t *ic,
518 const struct ieee80211_cipher *cip)
519 {
520 if (cip->ic_cipher >= IEEE80211_CIPHER_MAX) {
521 ieee80211_err("ieee80211_crypto_unregister: "
522 "cipher %s has an invalid cipher index %u\n",
523 cip->ic_name, cip->ic_cipher);
524 return;
525 }
526 if (ic->ic_ciphers[cip->ic_cipher] != NULL &&
527 ic->ic_ciphers[cip->ic_cipher] != cip) {
528 ieee80211_err("ieee80211_crypto_unregister: "
529 "cipher %s registered with a different template\n",
530 cip->ic_name);
531 return;
532 }
533 /* NB: don't complain about not being registered */
534 ic->ic_ciphers[cip->ic_cipher] = NULL;
535 }
536