2 * Copyright (c) 2001 Atsushi Onoe
3 * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
31 * IEEE 802.11 generic crypto support.
35 #include <sys/param.h>
36 #include <sys/kernel.h>
37 #include <sys/malloc.h>
40 #include <sys/socket.h>
43 #include <net/if_media.h>
44 #include <net/ethernet.h> /* XXX ETHER_HDR_LEN */
46 #include <netproto/802_11/ieee80211_var.h>
48 MALLOC_DEFINE(M_80211_CRYPTO, "80211crypto", "802.11 crypto state");
50 static int _ieee80211_crypto_delkey(struct ieee80211vap *,
51 struct ieee80211_key *);
54 * Table of registered cipher modules.
56 static const struct ieee80211_cipher *ciphers[IEEE80211_CIPHER_MAX];
59 * Default "null" key management routines.
62 null_key_alloc(struct ieee80211vap *vap, struct ieee80211_key *k,
63 ieee80211_keyix *keyix, ieee80211_keyix *rxkeyix)
65 if (!(&vap->iv_nw_keys[0] <= k &&
66 k < &vap->iv_nw_keys[IEEE80211_WEP_NKID])) {
68 * Not in the global key table, the driver should handle this
69 * by allocating a slot in the h/w key table/cache. In
70 * lieu of that return key slot 0 for any unicast key
71 * request. We disallow the request if this is a group key.
72 * This default policy does the right thing for legacy hardware
73 * with a 4 key table. It also handles devices that pass
74 * packets through untouched when marked with the WEP bit
77 if (k->wk_flags & IEEE80211_KEY_GROUP)
79 *keyix = 0; /* NB: use key index 0 for ucast key */
81 *keyix = k - vap->iv_nw_keys;
83 *rxkeyix = IEEE80211_KEYIX_NONE; /* XXX maybe *keyix? */
87 null_key_delete(struct ieee80211vap *vap, const struct ieee80211_key *k)
92 null_key_set(struct ieee80211vap *vap, const struct ieee80211_key *k)
96 static void null_key_update(struct ieee80211vap *vap) {}
99 * Write-arounds for common operations.
102 cipher_detach(struct ieee80211_key *key)
104 key->wk_cipher->ic_detach(key);
107 static __inline void *
108 cipher_attach(struct ieee80211vap *vap, struct ieee80211_key *key)
110 return key->wk_cipher->ic_attach(vap, key);
114 * Wrappers for driver key management methods.
117 dev_key_alloc(struct ieee80211vap *vap,
118 struct ieee80211_key *key,
119 ieee80211_keyix *keyix, ieee80211_keyix *rxkeyix)
121 return vap->iv_key_alloc(vap, key, keyix, rxkeyix);
125 dev_key_delete(struct ieee80211vap *vap,
126 const struct ieee80211_key *key)
128 return vap->iv_key_delete(vap, key);
132 dev_key_set(struct ieee80211vap *vap, const struct ieee80211_key *key)
134 return vap->iv_key_set(vap, key);
138 * Setup crypto support for a device/shared instance.
141 ieee80211_crypto_attach(struct ieee80211com *ic)
143 /* NB: we assume everything is pre-zero'd */
144 ciphers[IEEE80211_CIPHER_NONE] = &ieee80211_cipher_none;
148 * Teardown crypto support.
151 ieee80211_crypto_detach(struct ieee80211com *ic)
156 * Setup crypto support for a vap.
159 ieee80211_crypto_vattach(struct ieee80211vap *vap)
163 /* NB: we assume everything is pre-zero'd */
164 vap->iv_max_keyix = IEEE80211_WEP_NKID;
165 vap->iv_def_txkey = IEEE80211_KEYIX_NONE;
166 for (i = 0; i < IEEE80211_WEP_NKID; i++)
167 ieee80211_crypto_resetkey(vap, &vap->iv_nw_keys[i],
168 IEEE80211_KEYIX_NONE);
170 * Initialize the driver key support routines to noop entries.
171 * This is useful especially for the cipher test modules.
173 vap->iv_key_alloc = null_key_alloc;
174 vap->iv_key_set = null_key_set;
175 vap->iv_key_delete = null_key_delete;
176 vap->iv_key_update_begin = null_key_update;
177 vap->iv_key_update_end = null_key_update;
181 * Teardown crypto support for a vap.
184 ieee80211_crypto_vdetach(struct ieee80211vap *vap)
186 ieee80211_crypto_delglobalkeys(vap);
190 * Register a crypto cipher module.
193 ieee80211_crypto_register(const struct ieee80211_cipher *cip)
195 if (cip->ic_cipher >= IEEE80211_CIPHER_MAX) {
196 kprintf("%s: cipher %s has an invalid cipher index %u\n",
197 __func__, cip->ic_name, cip->ic_cipher);
200 if (ciphers[cip->ic_cipher] != NULL && ciphers[cip->ic_cipher] != cip) {
201 kprintf("%s: cipher %s registered with a different template\n",
202 __func__, cip->ic_name);
205 ciphers[cip->ic_cipher] = cip;
209 * Unregister a crypto cipher module.
212 ieee80211_crypto_unregister(const struct ieee80211_cipher *cip)
214 if (cip->ic_cipher >= IEEE80211_CIPHER_MAX) {
215 kprintf("%s: cipher %s has an invalid cipher index %u\n",
216 __func__, cip->ic_name, cip->ic_cipher);
219 if (ciphers[cip->ic_cipher] != NULL && ciphers[cip->ic_cipher] != cip) {
220 kprintf("%s: cipher %s registered with a different template\n",
221 __func__, cip->ic_name);
224 /* NB: don't complain about not being registered */
225 /* XXX disallow if references */
226 ciphers[cip->ic_cipher] = NULL;
230 ieee80211_crypto_available(u_int cipher)
232 return cipher < IEEE80211_CIPHER_MAX && ciphers[cipher] != NULL;
235 /* XXX well-known names! */
236 static const char *cipher_modnames[IEEE80211_CIPHER_MAX] = {
237 [IEEE80211_CIPHER_WEP] = "wlan_wep",
238 [IEEE80211_CIPHER_TKIP] = "wlan_tkip",
239 [IEEE80211_CIPHER_AES_OCB] = "wlan_aes_ocb",
240 [IEEE80211_CIPHER_AES_CCM] = "wlan_ccmp",
241 [IEEE80211_CIPHER_TKIPMIC] = "#4", /* NB: reserved */
242 [IEEE80211_CIPHER_CKIP] = "wlan_ckip",
243 [IEEE80211_CIPHER_NONE] = "wlan_none",
246 /* NB: there must be no overlap between user-supplied and device-owned flags */
247 CTASSERT((IEEE80211_KEY_COMMON & IEEE80211_KEY_DEVICE) == 0);
250 * Establish a relationship between the specified key and cipher
251 * and, if necessary, allocate a hardware index from the driver.
252 * Note that when a fixed key index is required it must be specified.
254 * This must be the first call applied to a key; all the other key
255 * routines assume wk_cipher is setup.
257 * Locking must be handled by the caller using:
258 * ieee80211_key_update_begin(vap);
259 * ieee80211_key_update_end(vap);
262 ieee80211_crypto_newkey(struct ieee80211vap *vap,
263 int cipher, int flags, struct ieee80211_key *key)
265 struct ieee80211com *ic = vap->iv_ic;
266 const struct ieee80211_cipher *cip;
267 ieee80211_keyix keyix, rxkeyix;
271 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
272 "%s: cipher %u flags 0x%x keyix %u\n",
273 __func__, cipher, flags, key->wk_keyix);
276 * Validate cipher and set reference to cipher routines.
278 if (cipher >= IEEE80211_CIPHER_MAX) {
279 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
280 "%s: invalid cipher %u\n", __func__, cipher);
281 vap->iv_stats.is_crypto_badcipher++;
284 cip = ciphers[cipher];
287 * Auto-load cipher module if we have a well-known name
288 * for it. It might be better to use string names rather
289 * than numbers and craft a module name based on the cipher
290 * name; e.g. wlan_cipher_<cipher-name>.
292 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
293 "%s: unregistered cipher %u, load module %s\n",
294 __func__, cipher, cipher_modnames[cipher]);
295 ieee80211_load_module(cipher_modnames[cipher]);
297 * If cipher module loaded it should immediately
298 * call ieee80211_crypto_register which will fill
299 * in the entry in the ciphers array.
301 cip = ciphers[cipher];
303 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
304 "%s: unable to load cipher %u, module %s\n",
305 __func__, cipher, cipher_modnames[cipher]);
306 vap->iv_stats.is_crypto_nocipher++;
311 oflags = key->wk_flags;
312 flags &= IEEE80211_KEY_COMMON;
313 /* NB: preserve device attributes */
314 flags |= (oflags & IEEE80211_KEY_DEVICE);
316 * If the hardware does not support the cipher then
317 * fallback to a host-based implementation.
319 if ((ic->ic_cryptocaps & (1<<cipher)) == 0) {
320 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
321 "%s: no h/w support for cipher %s, falling back to s/w\n",
322 __func__, cip->ic_name);
323 flags |= IEEE80211_KEY_SWCRYPT;
326 * Hardware TKIP with software MIC is an important
327 * combination; we handle it by flagging each key,
328 * the cipher modules honor it.
330 if (cipher == IEEE80211_CIPHER_TKIP &&
331 (ic->ic_cryptocaps & IEEE80211_CRYPTO_TKIPMIC) == 0) {
332 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
333 "%s: no h/w support for TKIP MIC, falling back to s/w\n",
335 flags |= IEEE80211_KEY_SWMIC;
339 * Bind cipher to key instance. Note we do this
340 * after checking the device capabilities so the
341 * cipher module can optimize space usage based on
342 * whether or not it needs to do the cipher work.
344 if (key->wk_cipher != cip || key->wk_flags != flags) {
346 * Fillin the flags so cipher modules can see s/w
347 * crypto requirements and potentially allocate
348 * different state and/or attach different method
351 key->wk_flags = flags;
352 keyctx = cip->ic_attach(vap, key);
353 if (keyctx == NULL) {
354 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
355 "%s: unable to attach cipher %s\n",
356 __func__, cip->ic_name);
357 key->wk_flags = oflags; /* restore old flags */
358 vap->iv_stats.is_crypto_attachfail++;
362 key->wk_cipher = cip; /* XXX refcnt? */
363 key->wk_private = keyctx;
367 * Ask the driver for a key index if we don't have one.
368 * Note that entries in the global key table always have
369 * an index; this means it's safe to call this routine
370 * for these entries just to setup the reference to the
371 * cipher template. Note also that when using software
372 * crypto we also call the driver to give us a key index.
374 if ((key->wk_flags & IEEE80211_KEY_DEVKEY) == 0) {
375 if (!dev_key_alloc(vap, key, &keyix, &rxkeyix)) {
377 * Unable to setup driver state.
379 vap->iv_stats.is_crypto_keyfail++;
380 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
381 "%s: unable to setup cipher %s\n",
382 __func__, cip->ic_name);
385 if (key->wk_flags != flags) {
387 * Driver overrode flags we setup; typically because
388 * resources were unavailable to handle _this_ key.
389 * Re-attach the cipher context to allow cipher
390 * modules to handle differing requirements.
392 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
393 "%s: driver override for cipher %s, flags "
394 "0x%x -> 0x%x\n", __func__, cip->ic_name,
395 oflags, key->wk_flags);
396 keyctx = cip->ic_attach(vap, key);
397 if (keyctx == NULL) {
398 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
399 "%s: unable to attach cipher %s with "
400 "flags 0x%x\n", __func__, cip->ic_name,
402 key->wk_flags = oflags; /* restore old flags */
403 vap->iv_stats.is_crypto_attachfail++;
407 key->wk_cipher = cip; /* XXX refcnt? */
408 key->wk_private = keyctx;
410 key->wk_keyix = keyix;
411 key->wk_rxkeyix = rxkeyix;
412 key->wk_flags |= IEEE80211_KEY_DEVKEY;
418 * Remove the key (no locking, for internal use).
421 _ieee80211_crypto_delkey(struct ieee80211vap *vap, struct ieee80211_key *key)
423 KASSERT(key->wk_cipher != NULL, ("No cipher!"));
425 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
426 "%s: %s keyix %u flags 0x%x rsc %ju tsc %ju len %u\n",
427 __func__, key->wk_cipher->ic_name,
428 key->wk_keyix, key->wk_flags,
429 key->wk_keyrsc[IEEE80211_NONQOS_TID], key->wk_keytsc,
432 if (key->wk_flags & IEEE80211_KEY_DEVKEY) {
434 * Remove hardware entry.
437 if (!dev_key_delete(vap, key)) {
438 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
439 "%s: driver did not delete key index %u\n",
440 __func__, key->wk_keyix);
441 vap->iv_stats.is_crypto_delkey++;
446 memset(key, 0, sizeof(*key));
447 ieee80211_crypto_resetkey(vap, key, IEEE80211_KEYIX_NONE);
452 * Remove the specified key.
455 ieee80211_crypto_delkey(struct ieee80211vap *vap, struct ieee80211_key *key)
459 ieee80211_key_update_begin(vap);
460 status = _ieee80211_crypto_delkey(vap, key);
461 ieee80211_key_update_end(vap);
466 * Clear the global key table.
469 ieee80211_crypto_delglobalkeys(struct ieee80211vap *vap)
473 ieee80211_key_update_begin(vap);
474 for (i = 0; i < IEEE80211_WEP_NKID; i++)
475 (void) _ieee80211_crypto_delkey(vap, &vap->iv_nw_keys[i]);
476 ieee80211_key_update_end(vap);
480 * Set the contents of the specified key.
482 * Locking must be handled by the caller using:
483 * ieee80211_key_update_begin(vap);
484 * ieee80211_key_update_end(vap);
487 ieee80211_crypto_setkey(struct ieee80211vap *vap, struct ieee80211_key *key)
489 const struct ieee80211_cipher *cip = key->wk_cipher;
491 KASSERT(cip != NULL, ("No cipher!"));
493 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
494 "%s: %s keyix %u flags 0x%x mac %s rsc %ju tsc %ju len %u\n",
495 __func__, cip->ic_name, key->wk_keyix,
496 key->wk_flags, ether_sprintf(key->wk_macaddr),
497 key->wk_keyrsc[IEEE80211_NONQOS_TID], key->wk_keytsc,
500 if ((key->wk_flags & IEEE80211_KEY_DEVKEY) == 0) {
501 /* XXX nothing allocated, should not happen */
502 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
503 "%s: no device key setup done; should not happen!\n",
505 vap->iv_stats.is_crypto_setkey_nokey++;
509 * Give cipher a chance to validate key contents.
510 * XXX should happen before modifying state.
512 if (!cip->ic_setkey(key)) {
513 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
514 "%s: cipher %s rejected key index %u len %u flags 0x%x\n",
515 __func__, cip->ic_name, key->wk_keyix,
516 key->wk_keylen, key->wk_flags);
517 vap->iv_stats.is_crypto_setkey_cipher++;
520 return dev_key_set(vap, key);
524 ieee80211_crypto_get_keyid(struct ieee80211vap *vap, struct ieee80211_key *k)
526 if (k >= &vap->iv_nw_keys[0] &&
527 k < &vap->iv_nw_keys[IEEE80211_WEP_NKID])
528 return (k - vap->iv_nw_keys);
533 struct ieee80211_key *
534 ieee80211_crypto_get_txkey(struct ieee80211_node *ni, struct mbuf *m)
536 struct ieee80211vap *vap = ni->ni_vap;
537 struct ieee80211_frame *wh;
540 * Multicast traffic always uses the multicast key.
541 * Otherwise if a unicast key is set we use that and
542 * it is always key index 0. When no unicast key is
543 * set we fall back to the default transmit key.
545 wh = mtod(m, struct ieee80211_frame *);
546 if (IEEE80211_IS_MULTICAST(wh->i_addr1) ||
547 IEEE80211_KEY_UNDEFINED(&ni->ni_ucastkey)) {
548 if (vap->iv_def_txkey == IEEE80211_KEYIX_NONE) {
549 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO,
551 "no default transmit key (%s) deftxkey %u",
552 __func__, vap->iv_def_txkey);
553 vap->iv_stats.is_tx_nodefkey++;
556 return &vap->iv_nw_keys[vap->iv_def_txkey];
559 return &ni->ni_ucastkey;
563 * Add privacy headers appropriate for the specified key.
565 struct ieee80211_key *
566 ieee80211_crypto_encap(struct ieee80211_node *ni, struct mbuf *m)
568 struct ieee80211_key *k;
569 const struct ieee80211_cipher *cip;
571 if ((k = ieee80211_crypto_get_txkey(ni, m)) != NULL) {
573 return (cip->ic_encap(k, m) ? k : NULL);
580 * Validate and strip privacy headers (and trailer) for a
581 * received frame that has the WEP/Privacy bit set.
583 struct ieee80211_key *
584 ieee80211_crypto_decap(struct ieee80211_node *ni, struct mbuf *m, int hdrlen)
586 #define IEEE80211_WEP_HDRLEN (IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN)
587 #define IEEE80211_WEP_MINLEN \
588 (sizeof(struct ieee80211_frame) + \
589 IEEE80211_WEP_HDRLEN + IEEE80211_WEP_CRCLEN)
590 struct ieee80211vap *vap = ni->ni_vap;
591 struct ieee80211_key *k;
592 struct ieee80211_frame *wh;
593 const struct ieee80211_cipher *cip;
596 /* NB: this minimum size data frame could be bigger */
597 if (m->m_pkthdr.len < IEEE80211_WEP_MINLEN) {
598 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ANY,
599 "%s: WEP data frame too short, len %u\n",
600 __func__, m->m_pkthdr.len);
601 vap->iv_stats.is_rx_tooshort++; /* XXX need unique stat? */
606 * Locate the key. If unicast and there is no unicast
607 * key then we fall back to the key id in the header.
608 * This assumes unicast keys are only configured when
609 * the key id in the header is meaningless (typically 0).
611 wh = mtod(m, struct ieee80211_frame *);
612 m_copydata(m, hdrlen + IEEE80211_WEP_IVLEN, sizeof(keyid), &keyid);
613 if (IEEE80211_IS_MULTICAST(wh->i_addr1) ||
614 IEEE80211_KEY_UNDEFINED(&ni->ni_ucastkey))
615 k = &vap->iv_nw_keys[keyid >> 6];
617 k = &ni->ni_ucastkey;
620 * Insure crypto header is contiguous for all decap work.
623 if (m->m_len < hdrlen + cip->ic_header &&
624 (m = m_pullup(m, hdrlen + cip->ic_header)) == NULL) {
625 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO, wh->i_addr2,
626 "unable to pullup %s header", cip->ic_name);
627 vap->iv_stats.is_rx_wepfail++; /* XXX */
631 return (cip->ic_decap(k, m, hdrlen) ? k : NULL);
632 #undef IEEE80211_WEP_MINLEN
633 #undef IEEE80211_WEP_HDRLEN
637 load_ucastkey(void *arg, struct ieee80211_node *ni)
639 struct ieee80211vap *vap = ni->ni_vap;
640 struct ieee80211_key *k;
642 if (vap->iv_state != IEEE80211_S_RUN)
644 k = &ni->ni_ucastkey;
645 if (k->wk_flags & IEEE80211_KEY_DEVKEY)
650 * Re-load all keys known to the 802.11 layer that may
651 * have hardware state backing them. This is used by
652 * drivers on resume to push keys down into the device.
655 ieee80211_crypto_reload_keys(struct ieee80211com *ic)
657 struct ieee80211vap *vap;
661 * Keys in the global key table of each vap.
663 /* NB: used only during resume so don't lock for now */
664 TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
665 if (vap->iv_state != IEEE80211_S_RUN)
667 for (i = 0; i < IEEE80211_WEP_NKID; i++) {
668 const struct ieee80211_key *k = &vap->iv_nw_keys[i];
669 if (k->wk_flags & IEEE80211_KEY_DEVKEY)
676 ieee80211_iterate_nodes(&ic->ic_sta, load_ucastkey, NULL);