Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetoot...
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / mac80211 / wpa.c
1 /*
2 * Copyright 2002-2004, Instant802 Networks, Inc.
3 * Copyright 2008, Jouni Malinen <j@w1.fi>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9
10 #include <linux/netdevice.h>
11 #include <linux/types.h>
12 #include <linux/skbuff.h>
13 #include <linux/compiler.h>
14 #include <linux/ieee80211.h>
15 #include <linux/gfp.h>
16 #include <asm/unaligned.h>
17 #include <net/mac80211.h>
18 #include <crypto/aes.h>
19
20 #include "ieee80211_i.h"
21 #include "michael.h"
22 #include "tkip.h"
23 #include "aes_ccm.h"
24 #include "aes_cmac.h"
25 #include "wpa.h"
26
27 ieee80211_tx_result
28 ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
29 {
30 u8 *data, *key, *mic;
31 size_t data_len;
32 unsigned int hdrlen;
33 struct ieee80211_hdr *hdr;
34 struct sk_buff *skb = tx->skb;
35 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
36 int tail;
37
38 hdr = (struct ieee80211_hdr *)skb->data;
39 if (!tx->key || tx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
40 skb->len < 24 || !ieee80211_is_data_present(hdr->frame_control))
41 return TX_CONTINUE;
42
43 hdrlen = ieee80211_hdrlen(hdr->frame_control);
44 if (skb->len < hdrlen)
45 return TX_DROP;
46
47 data = skb->data + hdrlen;
48 data_len = skb->len - hdrlen;
49
50 if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) {
51 /* Need to use software crypto for the test */
52 info->control.hw_key = NULL;
53 }
54
55 if (info->control.hw_key &&
56 (info->flags & IEEE80211_TX_CTL_DONTFRAG ||
57 tx->local->ops->set_frag_threshold) &&
58 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) {
59 /* hwaccel - with no need for SW-generated MMIC */
60 return TX_CONTINUE;
61 }
62
63 tail = MICHAEL_MIC_LEN;
64 if (!info->control.hw_key)
65 tail += TKIP_ICV_LEN;
66
67 if (WARN_ON(skb_tailroom(skb) < tail ||
68 skb_headroom(skb) < TKIP_IV_LEN))
69 return TX_DROP;
70
71 key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY];
72 mic = skb_put(skb, MICHAEL_MIC_LEN);
73 michael_mic(key, hdr, data, data_len, mic);
74 if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE))
75 mic[0]++;
76
77 return TX_CONTINUE;
78 }
79
80
81 ieee80211_rx_result
82 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
83 {
84 u8 *data, *key = NULL;
85 size_t data_len;
86 unsigned int hdrlen;
87 u8 mic[MICHAEL_MIC_LEN];
88 struct sk_buff *skb = rx->skb;
89 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
90 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
91
92 /*
93 * it makes no sense to check for MIC errors on anything other
94 * than data frames.
95 */
96 if (!ieee80211_is_data_present(hdr->frame_control))
97 return RX_CONTINUE;
98
99 /*
100 * No way to verify the MIC if the hardware stripped it or
101 * the IV with the key index. In this case we have solely rely
102 * on the driver to set RX_FLAG_MMIC_ERROR in the event of a
103 * MIC failure report.
104 */
105 if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) {
106 if (status->flag & RX_FLAG_MMIC_ERROR)
107 goto mic_fail;
108
109 if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key)
110 goto update_iv;
111
112 return RX_CONTINUE;
113 }
114
115 /*
116 * Some hardware seems to generate Michael MIC failure reports; even
117 * though, the frame was not encrypted with TKIP and therefore has no
118 * MIC. Ignore the flag them to avoid triggering countermeasures.
119 */
120 if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
121 !(status->flag & RX_FLAG_DECRYPTED))
122 return RX_CONTINUE;
123
124 if (rx->sdata->vif.type == NL80211_IFTYPE_AP && rx->key->conf.keyidx) {
125 /*
126 * APs with pairwise keys should never receive Michael MIC
127 * errors for non-zero keyidx because these are reserved for
128 * group keys and only the AP is sending real multicast
129 * frames in the BSS. (
130 */
131 return RX_DROP_UNUSABLE;
132 }
133
134 if (status->flag & RX_FLAG_MMIC_ERROR)
135 goto mic_fail;
136
137 hdrlen = ieee80211_hdrlen(hdr->frame_control);
138 if (skb->len < hdrlen + MICHAEL_MIC_LEN)
139 return RX_DROP_UNUSABLE;
140
141 if (skb_linearize(rx->skb))
142 return RX_DROP_UNUSABLE;
143 hdr = (void *)skb->data;
144
145 data = skb->data + hdrlen;
146 data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;
147 key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY];
148 michael_mic(key, hdr, data, data_len, mic);
149 if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0)
150 goto mic_fail;
151
152 /* remove Michael MIC from payload */
153 skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
154
155 update_iv:
156 /* update IV in key information to be able to detect replays */
157 rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip_iv32;
158 rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip_iv16;
159
160 return RX_CONTINUE;
161
162 mic_fail:
163 /*
164 * In some cases the key can be unset - e.g. a multicast packet, in
165 * a driver that supports HW encryption. Send up the key idx only if
166 * the key is set.
167 */
168 mac80211_ev_michael_mic_failure(rx->sdata,
169 rx->key ? rx->key->conf.keyidx : -1,
170 (void *) skb->data, NULL, GFP_ATOMIC);
171 return RX_DROP_UNUSABLE;
172 }
173
174
175 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
176 {
177 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
178 struct ieee80211_key *key = tx->key;
179 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
180 unsigned long flags;
181 unsigned int hdrlen;
182 int len, tail;
183 u8 *pos;
184
185 if (info->control.hw_key &&
186 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
187 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
188 /* hwaccel - with no need for software-generated IV */
189 return 0;
190 }
191
192 hdrlen = ieee80211_hdrlen(hdr->frame_control);
193 len = skb->len - hdrlen;
194
195 if (info->control.hw_key)
196 tail = 0;
197 else
198 tail = TKIP_ICV_LEN;
199
200 if (WARN_ON(skb_tailroom(skb) < tail ||
201 skb_headroom(skb) < TKIP_IV_LEN))
202 return -1;
203
204 pos = skb_push(skb, TKIP_IV_LEN);
205 memmove(pos, pos + TKIP_IV_LEN, hdrlen);
206 skb_set_network_header(skb, skb_network_offset(skb) + TKIP_IV_LEN);
207 pos += hdrlen;
208
209 /* the HW only needs room for the IV, but not the actual IV */
210 if (info->control.hw_key &&
211 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
212 return 0;
213
214 /* Increase IV for the frame */
215 spin_lock_irqsave(&key->u.tkip.txlock, flags);
216 key->u.tkip.tx.iv16++;
217 if (key->u.tkip.tx.iv16 == 0)
218 key->u.tkip.tx.iv32++;
219 pos = ieee80211_tkip_add_iv(pos, key);
220 spin_unlock_irqrestore(&key->u.tkip.txlock, flags);
221
222 /* hwaccel - with software IV */
223 if (info->control.hw_key)
224 return 0;
225
226 /* Add room for ICV */
227 skb_put(skb, TKIP_ICV_LEN);
228
229 return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
230 key, skb, pos, len);
231 }
232
233
234 ieee80211_tx_result
235 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
236 {
237 struct sk_buff *skb;
238
239 ieee80211_tx_set_protected(tx);
240
241 skb_queue_walk(&tx->skbs, skb) {
242 if (tkip_encrypt_skb(tx, skb) < 0)
243 return TX_DROP;
244 }
245
246 return TX_CONTINUE;
247 }
248
249
250 ieee80211_rx_result
251 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
252 {
253 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
254 int hdrlen, res, hwaccel = 0;
255 struct ieee80211_key *key = rx->key;
256 struct sk_buff *skb = rx->skb;
257 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
258
259 hdrlen = ieee80211_hdrlen(hdr->frame_control);
260
261 if (!ieee80211_is_data(hdr->frame_control))
262 return RX_CONTINUE;
263
264 if (!rx->sta || skb->len - hdrlen < 12)
265 return RX_DROP_UNUSABLE;
266
267 /* it may be possible to optimize this a bit more */
268 if (skb_linearize(rx->skb))
269 return RX_DROP_UNUSABLE;
270 hdr = (void *)skb->data;
271
272 /*
273 * Let TKIP code verify IV, but skip decryption.
274 * In the case where hardware checks the IV as well,
275 * we don't even get here, see ieee80211_rx_h_decrypt()
276 */
277 if (status->flag & RX_FLAG_DECRYPTED)
278 hwaccel = 1;
279
280 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
281 key, skb->data + hdrlen,
282 skb->len - hdrlen, rx->sta->sta.addr,
283 hdr->addr1, hwaccel, rx->security_idx,
284 &rx->tkip_iv32,
285 &rx->tkip_iv16);
286 if (res != TKIP_DECRYPT_OK)
287 return RX_DROP_UNUSABLE;
288
289 /* Trim ICV */
290 skb_trim(skb, skb->len - TKIP_ICV_LEN);
291
292 /* Remove IV */
293 memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
294 skb_pull(skb, TKIP_IV_LEN);
295
296 return RX_CONTINUE;
297 }
298
299
300 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch,
301 int encrypted)
302 {
303 __le16 mask_fc;
304 int a4_included, mgmt;
305 u8 qos_tid;
306 u8 *b_0, *aad;
307 u16 data_len, len_a;
308 unsigned int hdrlen;
309 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
310
311 memset(scratch, 0, 6 * AES_BLOCK_SIZE);
312
313 b_0 = scratch + 3 * AES_BLOCK_SIZE;
314 aad = scratch + 4 * AES_BLOCK_SIZE;
315
316 /*
317 * Mask FC: zero subtype b4 b5 b6 (if not mgmt)
318 * Retry, PwrMgt, MoreData; set Protected
319 */
320 mgmt = ieee80211_is_mgmt(hdr->frame_control);
321 mask_fc = hdr->frame_control;
322 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
323 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
324 if (!mgmt)
325 mask_fc &= ~cpu_to_le16(0x0070);
326 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
327
328 hdrlen = ieee80211_hdrlen(hdr->frame_control);
329 len_a = hdrlen - 2;
330 a4_included = ieee80211_has_a4(hdr->frame_control);
331
332 if (ieee80211_is_data_qos(hdr->frame_control))
333 qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
334 else
335 qos_tid = 0;
336
337 data_len = skb->len - hdrlen - CCMP_HDR_LEN;
338 if (encrypted)
339 data_len -= CCMP_MIC_LEN;
340
341 /* First block, b_0 */
342 b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
343 /* Nonce: Nonce Flags | A2 | PN
344 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)
345 */
346 b_0[1] = qos_tid | (mgmt << 4);
347 memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
348 memcpy(&b_0[8], pn, CCMP_PN_LEN);
349 /* l(m) */
350 put_unaligned_be16(data_len, &b_0[14]);
351
352 /* AAD (extra authenticate-only data) / masked 802.11 header
353 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
354 put_unaligned_be16(len_a, &aad[0]);
355 put_unaligned(mask_fc, (__le16 *)&aad[2]);
356 memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
357
358 /* Mask Seq#, leave Frag# */
359 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
360 aad[23] = 0;
361
362 if (a4_included) {
363 memcpy(&aad[24], hdr->addr4, ETH_ALEN);
364 aad[30] = qos_tid;
365 aad[31] = 0;
366 } else {
367 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
368 aad[24] = qos_tid;
369 }
370 }
371
372
373 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
374 {
375 hdr[0] = pn[5];
376 hdr[1] = pn[4];
377 hdr[2] = 0;
378 hdr[3] = 0x20 | (key_id << 6);
379 hdr[4] = pn[3];
380 hdr[5] = pn[2];
381 hdr[6] = pn[1];
382 hdr[7] = pn[0];
383 }
384
385
386 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr)
387 {
388 pn[0] = hdr[7];
389 pn[1] = hdr[6];
390 pn[2] = hdr[5];
391 pn[3] = hdr[4];
392 pn[4] = hdr[1];
393 pn[5] = hdr[0];
394 }
395
396
397 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
398 {
399 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
400 struct ieee80211_key *key = tx->key;
401 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
402 int hdrlen, len, tail;
403 u8 *pos;
404 u8 pn[6];
405 u64 pn64;
406 u8 scratch[6 * AES_BLOCK_SIZE];
407
408 if (info->control.hw_key &&
409 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
410 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
411 /*
412 * hwaccel has no need for preallocated room for CCMP
413 * header or MIC fields
414 */
415 return 0;
416 }
417
418 hdrlen = ieee80211_hdrlen(hdr->frame_control);
419 len = skb->len - hdrlen;
420
421 if (info->control.hw_key)
422 tail = 0;
423 else
424 tail = CCMP_MIC_LEN;
425
426 if (WARN_ON(skb_tailroom(skb) < tail ||
427 skb_headroom(skb) < CCMP_HDR_LEN))
428 return -1;
429
430 pos = skb_push(skb, CCMP_HDR_LEN);
431 memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
432 skb_set_network_header(skb, skb_network_offset(skb) + CCMP_HDR_LEN);
433
434 /* the HW only needs room for the IV, but not the actual IV */
435 if (info->control.hw_key &&
436 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
437 return 0;
438
439 hdr = (struct ieee80211_hdr *) pos;
440 pos += hdrlen;
441
442 pn64 = atomic64_inc_return(&key->u.ccmp.tx_pn);
443
444 pn[5] = pn64;
445 pn[4] = pn64 >> 8;
446 pn[3] = pn64 >> 16;
447 pn[2] = pn64 >> 24;
448 pn[1] = pn64 >> 32;
449 pn[0] = pn64 >> 40;
450
451 ccmp_pn2hdr(pos, pn, key->conf.keyidx);
452
453 /* hwaccel - with software CCMP header */
454 if (info->control.hw_key)
455 return 0;
456
457 pos += CCMP_HDR_LEN;
458 ccmp_special_blocks(skb, pn, scratch, 0);
459 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, pos, len,
460 pos, skb_put(skb, CCMP_MIC_LEN));
461
462 return 0;
463 }
464
465
466 ieee80211_tx_result
467 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx)
468 {
469 struct sk_buff *skb;
470
471 ieee80211_tx_set_protected(tx);
472
473 skb_queue_walk(&tx->skbs, skb) {
474 if (ccmp_encrypt_skb(tx, skb) < 0)
475 return TX_DROP;
476 }
477
478 return TX_CONTINUE;
479 }
480
481
482 ieee80211_rx_result
483 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx)
484 {
485 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
486 int hdrlen;
487 struct ieee80211_key *key = rx->key;
488 struct sk_buff *skb = rx->skb;
489 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
490 u8 pn[CCMP_PN_LEN];
491 int data_len;
492 int queue;
493
494 hdrlen = ieee80211_hdrlen(hdr->frame_control);
495
496 if (!ieee80211_is_data(hdr->frame_control) &&
497 !ieee80211_is_robust_mgmt_frame(hdr))
498 return RX_CONTINUE;
499
500 data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
501 if (!rx->sta || data_len < 0)
502 return RX_DROP_UNUSABLE;
503
504 if (status->flag & RX_FLAG_DECRYPTED) {
505 if (!pskb_may_pull(rx->skb, hdrlen + CCMP_HDR_LEN))
506 return RX_DROP_UNUSABLE;
507 } else {
508 if (skb_linearize(rx->skb))
509 return RX_DROP_UNUSABLE;
510 }
511
512 ccmp_hdr2pn(pn, skb->data + hdrlen);
513
514 queue = rx->security_idx;
515
516 if (memcmp(pn, key->u.ccmp.rx_pn[queue], CCMP_PN_LEN) <= 0) {
517 key->u.ccmp.replays++;
518 return RX_DROP_UNUSABLE;
519 }
520
521 if (!(status->flag & RX_FLAG_DECRYPTED)) {
522 u8 scratch[6 * AES_BLOCK_SIZE];
523 /* hardware didn't decrypt/verify MIC */
524 ccmp_special_blocks(skb, pn, scratch, 1);
525
526 if (ieee80211_aes_ccm_decrypt(
527 key->u.ccmp.tfm, scratch,
528 skb->data + hdrlen + CCMP_HDR_LEN, data_len,
529 skb->data + skb->len - CCMP_MIC_LEN,
530 skb->data + hdrlen + CCMP_HDR_LEN))
531 return RX_DROP_UNUSABLE;
532 }
533
534 memcpy(key->u.ccmp.rx_pn[queue], pn, CCMP_PN_LEN);
535
536 /* Remove CCMP header and MIC */
537 if (pskb_trim(skb, skb->len - CCMP_MIC_LEN))
538 return RX_DROP_UNUSABLE;
539 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
540 skb_pull(skb, CCMP_HDR_LEN);
541
542 return RX_CONTINUE;
543 }
544
545
546 static void bip_aad(struct sk_buff *skb, u8 *aad)
547 {
548 /* BIP AAD: FC(masked) || A1 || A2 || A3 */
549
550 /* FC type/subtype */
551 aad[0] = skb->data[0];
552 /* Mask FC Retry, PwrMgt, MoreData flags to zero */
553 aad[1] = skb->data[1] & ~(BIT(4) | BIT(5) | BIT(6));
554 /* A1 || A2 || A3 */
555 memcpy(aad + 2, skb->data + 4, 3 * ETH_ALEN);
556 }
557
558
559 static inline void bip_ipn_set64(u8 *d, u64 pn)
560 {
561 *d++ = pn;
562 *d++ = pn >> 8;
563 *d++ = pn >> 16;
564 *d++ = pn >> 24;
565 *d++ = pn >> 32;
566 *d = pn >> 40;
567 }
568
569 static inline void bip_ipn_swap(u8 *d, const u8 *s)
570 {
571 *d++ = s[5];
572 *d++ = s[4];
573 *d++ = s[3];
574 *d++ = s[2];
575 *d++ = s[1];
576 *d = s[0];
577 }
578
579
580 ieee80211_tx_result
581 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
582 {
583 struct sk_buff *skb;
584 struct ieee80211_tx_info *info;
585 struct ieee80211_key *key = tx->key;
586 struct ieee80211_mmie *mmie;
587 u8 aad[20];
588 u64 pn64;
589
590 if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
591 return TX_DROP;
592
593 skb = skb_peek(&tx->skbs);
594
595 info = IEEE80211_SKB_CB(skb);
596
597 if (info->control.hw_key)
598 return TX_CONTINUE;
599
600 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
601 return TX_DROP;
602
603 mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie));
604 mmie->element_id = WLAN_EID_MMIE;
605 mmie->length = sizeof(*mmie) - 2;
606 mmie->key_id = cpu_to_le16(key->conf.keyidx);
607
608 /* PN = PN + 1 */
609 pn64 = atomic64_inc_return(&key->u.aes_cmac.tx_pn);
610
611 bip_ipn_set64(mmie->sequence_number, pn64);
612
613 bip_aad(skb, aad);
614
615 /*
616 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
617 */
618 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
619 skb->data + 24, skb->len - 24, mmie->mic);
620
621 return TX_CONTINUE;
622 }
623
624
625 ieee80211_rx_result
626 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
627 {
628 struct sk_buff *skb = rx->skb;
629 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
630 struct ieee80211_key *key = rx->key;
631 struct ieee80211_mmie *mmie;
632 u8 aad[20], mic[8], ipn[6];
633 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
634
635 if (!ieee80211_is_mgmt(hdr->frame_control))
636 return RX_CONTINUE;
637
638 /* management frames are already linear */
639
640 if (skb->len < 24 + sizeof(*mmie))
641 return RX_DROP_UNUSABLE;
642
643 mmie = (struct ieee80211_mmie *)
644 (skb->data + skb->len - sizeof(*mmie));
645 if (mmie->element_id != WLAN_EID_MMIE ||
646 mmie->length != sizeof(*mmie) - 2)
647 return RX_DROP_UNUSABLE; /* Invalid MMIE */
648
649 bip_ipn_swap(ipn, mmie->sequence_number);
650
651 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
652 key->u.aes_cmac.replays++;
653 return RX_DROP_UNUSABLE;
654 }
655
656 if (!(status->flag & RX_FLAG_DECRYPTED)) {
657 /* hardware didn't decrypt/verify MIC */
658 bip_aad(skb, aad);
659 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
660 skb->data + 24, skb->len - 24, mic);
661 if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
662 key->u.aes_cmac.icverrors++;
663 return RX_DROP_UNUSABLE;
664 }
665 }
666
667 memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
668
669 /* Remove MMIE */
670 skb_trim(skb, skb->len - sizeof(*mmie));
671
672 return RX_CONTINUE;
673 }
674
675 ieee80211_tx_result
676 ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx)
677 {
678 struct sk_buff *skb;
679 struct ieee80211_tx_info *info = NULL;
680
681 skb_queue_walk(&tx->skbs, skb) {
682 info = IEEE80211_SKB_CB(skb);
683
684 /* handle hw-only algorithm */
685 if (!info->control.hw_key)
686 return TX_DROP;
687 }
688
689 ieee80211_tx_set_protected(tx);
690
691 return TX_CONTINUE;
692 }