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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2002-2004, Instant802 Networks, Inc.
4 * Copyright 2008, Jouni Malinen <j@w1.fi>
5 * Copyright (C) 2016-2017 Intel Deutschland GmbH
6 * Copyright (C) 2020-2021 Intel Corporation
7 */
8
9#include <linux/netdevice.h>
10#include <linux/types.h>
11#include <linux/skbuff.h>
12#include <linux/compiler.h>
13#include <linux/ieee80211.h>
14#include <linux/gfp.h>
15#include <asm/unaligned.h>
16#include <net/mac80211.h>
17#include <crypto/aes.h>
18#include <crypto/algapi.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 "aes_gmac.h"
26#include "aes_gcm.h"
27#include "wpa.h"
28
29ieee80211_tx_result
30ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
31{
32 u8 *data, *key, *mic;
33 size_t data_len;
34 unsigned int hdrlen;
35 struct ieee80211_hdr *hdr;
36 struct sk_buff *skb = tx->skb;
37 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
38 int tail;
39
40 hdr = (struct ieee80211_hdr *)skb->data;
41 if (!tx->key || tx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
42 skb->len < 24 || !ieee80211_is_data_present(hdr->frame_control))
43 return TX_CONTINUE;
44
45 hdrlen = ieee80211_hdrlen(hdr->frame_control);
46 if (skb->len < hdrlen)
47 return TX_DROP;
48
49 data = skb->data + hdrlen;
50 data_len = skb->len - hdrlen;
51
52 if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) {
53 /* Need to use software crypto for the test */
54 info->control.hw_key = NULL;
55 }
56
57 if (info->control.hw_key &&
58 (info->flags & IEEE80211_TX_CTL_DONTFRAG ||
59 ieee80211_hw_check(&tx->local->hw, SUPPORTS_TX_FRAG)) &&
60 !(tx->key->conf.flags & (IEEE80211_KEY_FLAG_GENERATE_MMIC |
61 IEEE80211_KEY_FLAG_PUT_MIC_SPACE))) {
62 /* hwaccel - with no need for SW-generated MMIC or MIC space */
63 return TX_CONTINUE;
64 }
65
66 tail = MICHAEL_MIC_LEN;
67 if (!info->control.hw_key)
68 tail += IEEE80211_TKIP_ICV_LEN;
69
70 if (WARN(skb_tailroom(skb) < tail ||
71 skb_headroom(skb) < IEEE80211_TKIP_IV_LEN,
72 "mmic: not enough head/tail (%d/%d,%d/%d)\n",
73 skb_headroom(skb), IEEE80211_TKIP_IV_LEN,
74 skb_tailroom(skb), tail))
75 return TX_DROP;
76
77 mic = skb_put(skb, MICHAEL_MIC_LEN);
78
79 if (tx->key->conf.flags & IEEE80211_KEY_FLAG_PUT_MIC_SPACE) {
80 /* Zeroed MIC can help with debug */
81 memset(mic, 0, MICHAEL_MIC_LEN);
82 return TX_CONTINUE;
83 }
84
85 key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY];
86 michael_mic(key, hdr, data, data_len, mic);
87 if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE))
88 mic[0]++;
89
90 return TX_CONTINUE;
91}
92
93
94ieee80211_rx_result
95ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
96{
97 u8 *data, *key = NULL;
98 size_t data_len;
99 unsigned int hdrlen;
100 u8 mic[MICHAEL_MIC_LEN];
101 struct sk_buff *skb = rx->skb;
102 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
103 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
104
105 /*
106 * it makes no sense to check for MIC errors on anything other
107 * than data frames.
108 */
109 if (!ieee80211_is_data_present(hdr->frame_control))
110 return RX_CONTINUE;
111
112 /*
113 * No way to verify the MIC if the hardware stripped it or
114 * the IV with the key index. In this case we have solely rely
115 * on the driver to set RX_FLAG_MMIC_ERROR in the event of a
116 * MIC failure report.
117 */
118 if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) {
119 if (status->flag & RX_FLAG_MMIC_ERROR)
120 goto mic_fail_no_key;
121
122 if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key &&
123 rx->key->conf.cipher == WLAN_CIPHER_SUITE_TKIP)
124 goto update_iv;
125
126 return RX_CONTINUE;
127 }
128
129 /*
130 * Some hardware seems to generate Michael MIC failure reports; even
131 * though, the frame was not encrypted with TKIP and therefore has no
132 * MIC. Ignore the flag them to avoid triggering countermeasures.
133 */
134 if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
135 !(status->flag & RX_FLAG_DECRYPTED))
136 return RX_CONTINUE;
137
138 if (rx->sdata->vif.type == NL80211_IFTYPE_AP && rx->key->conf.keyidx) {
139 /*
140 * APs with pairwise keys should never receive Michael MIC
141 * errors for non-zero keyidx because these are reserved for
142 * group keys and only the AP is sending real multicast
143 * frames in the BSS.
144 */
145 return RX_DROP_UNUSABLE;
146 }
147
148 if (status->flag & RX_FLAG_MMIC_ERROR)
149 goto mic_fail;
150
151 hdrlen = ieee80211_hdrlen(hdr->frame_control);
152 if (skb->len < hdrlen + MICHAEL_MIC_LEN)
153 return RX_DROP_UNUSABLE;
154
155 if (skb_linearize(rx->skb))
156 return RX_DROP_UNUSABLE;
157 hdr = (void *)skb->data;
158
159 data = skb->data + hdrlen;
160 data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;
161 key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY];
162 michael_mic(key, hdr, data, data_len, mic);
163 if (crypto_memneq(mic, data + data_len, MICHAEL_MIC_LEN))
164 goto mic_fail;
165
166 /* remove Michael MIC from payload */
167 skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
168
169update_iv:
170 /* update IV in key information to be able to detect replays */
171 rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip.iv32;
172 rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip.iv16;
173
174 return RX_CONTINUE;
175
176mic_fail:
177 rx->key->u.tkip.mic_failures++;
178
179mic_fail_no_key:
180 /*
181 * In some cases the key can be unset - e.g. a multicast packet, in
182 * a driver that supports HW encryption. Send up the key idx only if
183 * the key is set.
184 */
185 cfg80211_michael_mic_failure(rx->sdata->dev, hdr->addr2,
186 is_multicast_ether_addr(hdr->addr1) ?
187 NL80211_KEYTYPE_GROUP :
188 NL80211_KEYTYPE_PAIRWISE,
189 rx->key ? rx->key->conf.keyidx : -1,
190 NULL, GFP_ATOMIC);
191 return RX_DROP_UNUSABLE;
192}
193
194static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
195{
196 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
197 struct ieee80211_key *key = tx->key;
198 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
199 unsigned int hdrlen;
200 int len, tail;
201 u64 pn;
202 u8 *pos;
203
204 if (info->control.hw_key &&
205 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
206 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
207 /* hwaccel - with no need for software-generated IV */
208 return 0;
209 }
210
211 hdrlen = ieee80211_hdrlen(hdr->frame_control);
212 len = skb->len - hdrlen;
213
214 if (info->control.hw_key)
215 tail = 0;
216 else
217 tail = IEEE80211_TKIP_ICV_LEN;
218
219 if (WARN_ON(skb_tailroom(skb) < tail ||
220 skb_headroom(skb) < IEEE80211_TKIP_IV_LEN))
221 return -1;
222
223 pos = skb_push(skb, IEEE80211_TKIP_IV_LEN);
224 memmove(pos, pos + IEEE80211_TKIP_IV_LEN, hdrlen);
225 pos += hdrlen;
226
227 /* the HW only needs room for the IV, but not the actual IV */
228 if (info->control.hw_key &&
229 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
230 return 0;
231
232 /* Increase IV for the frame */
233 pn = atomic64_inc_return(&key->conf.tx_pn);
234 pos = ieee80211_tkip_add_iv(pos, &key->conf, pn);
235
236 /* hwaccel - with software IV */
237 if (info->control.hw_key)
238 return 0;
239
240 /* Add room for ICV */
241 skb_put(skb, IEEE80211_TKIP_ICV_LEN);
242
243 return ieee80211_tkip_encrypt_data(&tx->local->wep_tx_ctx,
244 key, skb, pos, len);
245}
246
247
248ieee80211_tx_result
249ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
250{
251 struct sk_buff *skb;
252
253 ieee80211_tx_set_protected(tx);
254
255 skb_queue_walk(&tx->skbs, skb) {
256 if (tkip_encrypt_skb(tx, skb) < 0)
257 return TX_DROP;
258 }
259
260 return TX_CONTINUE;
261}
262
263
264ieee80211_rx_result
265ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
266{
267 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
268 int hdrlen, res, hwaccel = 0;
269 struct ieee80211_key *key = rx->key;
270 struct sk_buff *skb = rx->skb;
271 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
272
273 hdrlen = ieee80211_hdrlen(hdr->frame_control);
274
275 if (!ieee80211_is_data(hdr->frame_control))
276 return RX_CONTINUE;
277
278 if (!rx->sta || skb->len - hdrlen < 12)
279 return RX_DROP_UNUSABLE;
280
281 /* it may be possible to optimize this a bit more */
282 if (skb_linearize(rx->skb))
283 return RX_DROP_UNUSABLE;
284 hdr = (void *)skb->data;
285
286 /*
287 * Let TKIP code verify IV, but skip decryption.
288 * In the case where hardware checks the IV as well,
289 * we don't even get here, see ieee80211_rx_h_decrypt()
290 */
291 if (status->flag & RX_FLAG_DECRYPTED)
292 hwaccel = 1;
293
294 res = ieee80211_tkip_decrypt_data(&rx->local->wep_rx_ctx,
295 key, skb->data + hdrlen,
296 skb->len - hdrlen, rx->sta->sta.addr,
297 hdr->addr1, hwaccel, rx->security_idx,
298 &rx->tkip.iv32,
299 &rx->tkip.iv16);
300 if (res != TKIP_DECRYPT_OK)
301 return RX_DROP_UNUSABLE;
302
303 /* Trim ICV */
304 if (!(status->flag & RX_FLAG_ICV_STRIPPED))
305 skb_trim(skb, skb->len - IEEE80211_TKIP_ICV_LEN);
306
307 /* Remove IV */
308 memmove(skb->data + IEEE80211_TKIP_IV_LEN, skb->data, hdrlen);
309 skb_pull(skb, IEEE80211_TKIP_IV_LEN);
310
311 return RX_CONTINUE;
312}
313
314
315static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad)
316{
317 __le16 mask_fc;
318 int a4_included, mgmt;
319 u8 qos_tid;
320 u16 len_a;
321 unsigned int hdrlen;
322 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
323
324 /*
325 * Mask FC: zero subtype b4 b5 b6 (if not mgmt)
326 * Retry, PwrMgt, MoreData; set Protected
327 */
328 mgmt = ieee80211_is_mgmt(hdr->frame_control);
329 mask_fc = hdr->frame_control;
330 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
331 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
332 if (!mgmt)
333 mask_fc &= ~cpu_to_le16(0x0070);
334 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
335
336 hdrlen = ieee80211_hdrlen(hdr->frame_control);
337 len_a = hdrlen - 2;
338 a4_included = ieee80211_has_a4(hdr->frame_control);
339
340 if (ieee80211_is_data_qos(hdr->frame_control))
341 qos_tid = ieee80211_get_tid(hdr);
342 else
343 qos_tid = 0;
344
345 /* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC
346 * mode authentication are not allowed to collide, yet both are derived
347 * from this vector b_0. We only set L := 1 here to indicate that the
348 * data size can be represented in (L+1) bytes. The CCM layer will take
349 * care of storing the data length in the top (L+1) bytes and setting
350 * and clearing the other bits as is required to derive the two IVs.
351 */
352 b_0[0] = 0x1;
353
354 /* Nonce: Nonce Flags | A2 | PN
355 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)
356 */
357 b_0[1] = qos_tid | (mgmt << 4);
358 memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
359 memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN);
360
361 /* AAD (extra authenticate-only data) / masked 802.11 header
362 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
363 put_unaligned_be16(len_a, &aad[0]);
364 put_unaligned(mask_fc, (__le16 *)&aad[2]);
365 memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
366
367 /* Mask Seq#, leave Frag# */
368 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
369 aad[23] = 0;
370
371 if (a4_included) {
372 memcpy(&aad[24], hdr->addr4, ETH_ALEN);
373 aad[30] = qos_tid;
374 aad[31] = 0;
375 } else {
376 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
377 aad[24] = qos_tid;
378 }
379}
380
381
382static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
383{
384 hdr[0] = pn[5];
385 hdr[1] = pn[4];
386 hdr[2] = 0;
387 hdr[3] = 0x20 | (key_id << 6);
388 hdr[4] = pn[3];
389 hdr[5] = pn[2];
390 hdr[6] = pn[1];
391 hdr[7] = pn[0];
392}
393
394
395static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr)
396{
397 pn[0] = hdr[7];
398 pn[1] = hdr[6];
399 pn[2] = hdr[5];
400 pn[3] = hdr[4];
401 pn[4] = hdr[1];
402 pn[5] = hdr[0];
403}
404
405
406static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb,
407 unsigned int mic_len)
408{
409 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
410 struct ieee80211_key *key = tx->key;
411 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
412 int hdrlen, len, tail;
413 u8 *pos;
414 u8 pn[6];
415 u64 pn64;
416 u8 aad[CCM_AAD_LEN];
417 u8 b_0[AES_BLOCK_SIZE];
418
419 if (info->control.hw_key &&
420 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
421 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
422 !((info->control.hw_key->flags &
423 IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
424 ieee80211_is_mgmt(hdr->frame_control))) {
425 /*
426 * hwaccel has no need for preallocated room for CCMP
427 * header or MIC fields
428 */
429 return 0;
430 }
431
432 hdrlen = ieee80211_hdrlen(hdr->frame_control);
433 len = skb->len - hdrlen;
434
435 if (info->control.hw_key)
436 tail = 0;
437 else
438 tail = mic_len;
439
440 if (WARN_ON(skb_tailroom(skb) < tail ||
441 skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN))
442 return -1;
443
444 pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN);
445 memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen);
446
447 /* the HW only needs room for the IV, but not the actual IV */
448 if (info->control.hw_key &&
449 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
450 return 0;
451
452 hdr = (struct ieee80211_hdr *) pos;
453 pos += hdrlen;
454
455 pn64 = atomic64_inc_return(&key->conf.tx_pn);
456
457 pn[5] = pn64;
458 pn[4] = pn64 >> 8;
459 pn[3] = pn64 >> 16;
460 pn[2] = pn64 >> 24;
461 pn[1] = pn64 >> 32;
462 pn[0] = pn64 >> 40;
463
464 ccmp_pn2hdr(pos, pn, key->conf.keyidx);
465
466 /* hwaccel - with software CCMP header */
467 if (info->control.hw_key)
468 return 0;
469
470 pos += IEEE80211_CCMP_HDR_LEN;
471 ccmp_special_blocks(skb, pn, b_0, aad);
472 return ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,
473 skb_put(skb, mic_len));
474}
475
476
477ieee80211_tx_result
478ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx,
479 unsigned int mic_len)
480{
481 struct sk_buff *skb;
482
483 ieee80211_tx_set_protected(tx);
484
485 skb_queue_walk(&tx->skbs, skb) {
486 if (ccmp_encrypt_skb(tx, skb, mic_len) < 0)
487 return TX_DROP;
488 }
489
490 return TX_CONTINUE;
491}
492
493
494ieee80211_rx_result
495ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
496 unsigned int mic_len)
497{
498 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
499 int hdrlen;
500 struct ieee80211_key *key = rx->key;
501 struct sk_buff *skb = rx->skb;
502 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
503 u8 pn[IEEE80211_CCMP_PN_LEN];
504 int data_len;
505 int queue;
506
507 hdrlen = ieee80211_hdrlen(hdr->frame_control);
508
509 if (!ieee80211_is_data(hdr->frame_control) &&
510 !ieee80211_is_robust_mgmt_frame(skb))
511 return RX_CONTINUE;
512
513 if (status->flag & RX_FLAG_DECRYPTED) {
514 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_CCMP_HDR_LEN))
515 return RX_DROP_UNUSABLE;
516 if (status->flag & RX_FLAG_MIC_STRIPPED)
517 mic_len = 0;
518 } else {
519 if (skb_linearize(rx->skb))
520 return RX_DROP_UNUSABLE;
521 }
522
523 /* reload hdr - skb might have been reallocated */
524 hdr = (void *)rx->skb->data;
525
526 data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - mic_len;
527 if (!rx->sta || data_len < 0)
528 return RX_DROP_UNUSABLE;
529
530 if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
531 int res;
532
533 ccmp_hdr2pn(pn, skb->data + hdrlen);
534
535 queue = rx->security_idx;
536
537 res = memcmp(pn, key->u.ccmp.rx_pn[queue],
538 IEEE80211_CCMP_PN_LEN);
539 if (res < 0 ||
540 (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
541 key->u.ccmp.replays++;
542 return RX_DROP_UNUSABLE;
543 }
544
545 if (!(status->flag & RX_FLAG_DECRYPTED)) {
546 u8 aad[2 * AES_BLOCK_SIZE];
547 u8 b_0[AES_BLOCK_SIZE];
548 /* hardware didn't decrypt/verify MIC */
549 ccmp_special_blocks(skb, pn, b_0, aad);
550
551 if (ieee80211_aes_ccm_decrypt(
552 key->u.ccmp.tfm, b_0, aad,
553 skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN,
554 data_len,
555 skb->data + skb->len - mic_len))
556 return RX_DROP_UNUSABLE;
557 }
558
559 memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN);
560 if (unlikely(ieee80211_is_frag(hdr)))
561 memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN);
562 }
563
564 /* Remove CCMP header and MIC */
565 if (pskb_trim(skb, skb->len - mic_len))
566 return RX_DROP_UNUSABLE;
567 memmove(skb->data + IEEE80211_CCMP_HDR_LEN, skb->data, hdrlen);
568 skb_pull(skb, IEEE80211_CCMP_HDR_LEN);
569
570 return RX_CONTINUE;
571}
572
573static void gcmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *j_0, u8 *aad)
574{
575 __le16 mask_fc;
576 u8 qos_tid;
577 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
578
579 memcpy(j_0, hdr->addr2, ETH_ALEN);
580 memcpy(&j_0[ETH_ALEN], pn, IEEE80211_GCMP_PN_LEN);
581 j_0[13] = 0;
582 j_0[14] = 0;
583 j_0[AES_BLOCK_SIZE - 1] = 0x01;
584
585 /* AAD (extra authenticate-only data) / masked 802.11 header
586 * FC | A1 | A2 | A3 | SC | [A4] | [QC]
587 */
588 put_unaligned_be16(ieee80211_hdrlen(hdr->frame_control) - 2, &aad[0]);
589 /* Mask FC: zero subtype b4 b5 b6 (if not mgmt)
590 * Retry, PwrMgt, MoreData; set Protected
591 */
592 mask_fc = hdr->frame_control;
593 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
594 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
595 if (!ieee80211_is_mgmt(hdr->frame_control))
596 mask_fc &= ~cpu_to_le16(0x0070);
597 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
598
599 put_unaligned(mask_fc, (__le16 *)&aad[2]);
600 memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
601
602 /* Mask Seq#, leave Frag# */
603 aad[22] = *((u8 *)&hdr->seq_ctrl) & 0x0f;
604 aad[23] = 0;
605
606 if (ieee80211_is_data_qos(hdr->frame_control))
607 qos_tid = ieee80211_get_tid(hdr);
608 else
609 qos_tid = 0;
610
611 if (ieee80211_has_a4(hdr->frame_control)) {
612 memcpy(&aad[24], hdr->addr4, ETH_ALEN);
613 aad[30] = qos_tid;
614 aad[31] = 0;
615 } else {
616 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
617 aad[24] = qos_tid;
618 }
619}
620
621static inline void gcmp_pn2hdr(u8 *hdr, const u8 *pn, int key_id)
622{
623 hdr[0] = pn[5];
624 hdr[1] = pn[4];
625 hdr[2] = 0;
626 hdr[3] = 0x20 | (key_id << 6);
627 hdr[4] = pn[3];
628 hdr[5] = pn[2];
629 hdr[6] = pn[1];
630 hdr[7] = pn[0];
631}
632
633static inline void gcmp_hdr2pn(u8 *pn, const u8 *hdr)
634{
635 pn[0] = hdr[7];
636 pn[1] = hdr[6];
637 pn[2] = hdr[5];
638 pn[3] = hdr[4];
639 pn[4] = hdr[1];
640 pn[5] = hdr[0];
641}
642
643static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
644{
645 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
646 struct ieee80211_key *key = tx->key;
647 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
648 int hdrlen, len, tail;
649 u8 *pos;
650 u8 pn[6];
651 u64 pn64;
652 u8 aad[GCM_AAD_LEN];
653 u8 j_0[AES_BLOCK_SIZE];
654
655 if (info->control.hw_key &&
656 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
657 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
658 !((info->control.hw_key->flags &
659 IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
660 ieee80211_is_mgmt(hdr->frame_control))) {
661 /* hwaccel has no need for preallocated room for GCMP
662 * header or MIC fields
663 */
664 return 0;
665 }
666
667 hdrlen = ieee80211_hdrlen(hdr->frame_control);
668 len = skb->len - hdrlen;
669
670 if (info->control.hw_key)
671 tail = 0;
672 else
673 tail = IEEE80211_GCMP_MIC_LEN;
674
675 if (WARN_ON(skb_tailroom(skb) < tail ||
676 skb_headroom(skb) < IEEE80211_GCMP_HDR_LEN))
677 return -1;
678
679 pos = skb_push(skb, IEEE80211_GCMP_HDR_LEN);
680 memmove(pos, pos + IEEE80211_GCMP_HDR_LEN, hdrlen);
681 skb_set_network_header(skb, skb_network_offset(skb) +
682 IEEE80211_GCMP_HDR_LEN);
683
684 /* the HW only needs room for the IV, but not the actual IV */
685 if (info->control.hw_key &&
686 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
687 return 0;
688
689 hdr = (struct ieee80211_hdr *)pos;
690 pos += hdrlen;
691
692 pn64 = atomic64_inc_return(&key->conf.tx_pn);
693
694 pn[5] = pn64;
695 pn[4] = pn64 >> 8;
696 pn[3] = pn64 >> 16;
697 pn[2] = pn64 >> 24;
698 pn[1] = pn64 >> 32;
699 pn[0] = pn64 >> 40;
700
701 gcmp_pn2hdr(pos, pn, key->conf.keyidx);
702
703 /* hwaccel - with software GCMP header */
704 if (info->control.hw_key)
705 return 0;
706
707 pos += IEEE80211_GCMP_HDR_LEN;
708 gcmp_special_blocks(skb, pn, j_0, aad);
709 return ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len,
710 skb_put(skb, IEEE80211_GCMP_MIC_LEN));
711}
712
713ieee80211_tx_result
714ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data *tx)
715{
716 struct sk_buff *skb;
717
718 ieee80211_tx_set_protected(tx);
719
720 skb_queue_walk(&tx->skbs, skb) {
721 if (gcmp_encrypt_skb(tx, skb) < 0)
722 return TX_DROP;
723 }
724
725 return TX_CONTINUE;
726}
727
728ieee80211_rx_result
729ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx)
730{
731 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
732 int hdrlen;
733 struct ieee80211_key *key = rx->key;
734 struct sk_buff *skb = rx->skb;
735 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
736 u8 pn[IEEE80211_GCMP_PN_LEN];
737 int data_len, queue, mic_len = IEEE80211_GCMP_MIC_LEN;
738
739 hdrlen = ieee80211_hdrlen(hdr->frame_control);
740
741 if (!ieee80211_is_data(hdr->frame_control) &&
742 !ieee80211_is_robust_mgmt_frame(skb))
743 return RX_CONTINUE;
744
745 if (status->flag & RX_FLAG_DECRYPTED) {
746 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN))
747 return RX_DROP_UNUSABLE;
748 if (status->flag & RX_FLAG_MIC_STRIPPED)
749 mic_len = 0;
750 } else {
751 if (skb_linearize(rx->skb))
752 return RX_DROP_UNUSABLE;
753 }
754
755 /* reload hdr - skb might have been reallocated */
756 hdr = (void *)rx->skb->data;
757
758 data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - mic_len;
759 if (!rx->sta || data_len < 0)
760 return RX_DROP_UNUSABLE;
761
762 if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
763 int res;
764
765 gcmp_hdr2pn(pn, skb->data + hdrlen);
766
767 queue = rx->security_idx;
768
769 res = memcmp(pn, key->u.gcmp.rx_pn[queue],
770 IEEE80211_GCMP_PN_LEN);
771 if (res < 0 ||
772 (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
773 key->u.gcmp.replays++;
774 return RX_DROP_UNUSABLE;
775 }
776
777 if (!(status->flag & RX_FLAG_DECRYPTED)) {
778 u8 aad[2 * AES_BLOCK_SIZE];
779 u8 j_0[AES_BLOCK_SIZE];
780 /* hardware didn't decrypt/verify MIC */
781 gcmp_special_blocks(skb, pn, j_0, aad);
782
783 if (ieee80211_aes_gcm_decrypt(
784 key->u.gcmp.tfm, j_0, aad,
785 skb->data + hdrlen + IEEE80211_GCMP_HDR_LEN,
786 data_len,
787 skb->data + skb->len -
788 IEEE80211_GCMP_MIC_LEN))
789 return RX_DROP_UNUSABLE;
790 }
791
792 memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN);
793 if (unlikely(ieee80211_is_frag(hdr)))
794 memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN);
795 }
796
797 /* Remove GCMP header and MIC */
798 if (pskb_trim(skb, skb->len - mic_len))
799 return RX_DROP_UNUSABLE;
800 memmove(skb->data + IEEE80211_GCMP_HDR_LEN, skb->data, hdrlen);
801 skb_pull(skb, IEEE80211_GCMP_HDR_LEN);
802
803 return RX_CONTINUE;
804}
805
806static ieee80211_tx_result
807ieee80211_crypto_cs_encrypt(struct ieee80211_tx_data *tx,
808 struct sk_buff *skb)
809{
810 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
811 struct ieee80211_key *key = tx->key;
812 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
813 int hdrlen;
814 u8 *pos, iv_len = key->conf.iv_len;
815
816 if (info->control.hw_key &&
817 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
818 /* hwaccel has no need for preallocated head room */
819 return TX_CONTINUE;
820 }
821
822 if (unlikely(skb_headroom(skb) < iv_len &&
823 pskb_expand_head(skb, iv_len, 0, GFP_ATOMIC)))
824 return TX_DROP;
825
826 hdrlen = ieee80211_hdrlen(hdr->frame_control);
827
828 pos = skb_push(skb, iv_len);
829 memmove(pos, pos + iv_len, hdrlen);
830
831 return TX_CONTINUE;
832}
833
834static inline int ieee80211_crypto_cs_pn_compare(u8 *pn1, u8 *pn2, int len)
835{
836 int i;
837
838 /* pn is little endian */
839 for (i = len - 1; i >= 0; i--) {
840 if (pn1[i] < pn2[i])
841 return -1;
842 else if (pn1[i] > pn2[i])
843 return 1;
844 }
845
846 return 0;
847}
848
849static ieee80211_rx_result
850ieee80211_crypto_cs_decrypt(struct ieee80211_rx_data *rx)
851{
852 struct ieee80211_key *key = rx->key;
853 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
854 const struct ieee80211_cipher_scheme *cs = NULL;
855 int hdrlen = ieee80211_hdrlen(hdr->frame_control);
856 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
857 int data_len;
858 u8 *rx_pn;
859 u8 *skb_pn;
860 u8 qos_tid;
861
862 if (!rx->sta || !rx->sta->cipher_scheme ||
863 !(status->flag & RX_FLAG_DECRYPTED))
864 return RX_DROP_UNUSABLE;
865
866 if (!ieee80211_is_data(hdr->frame_control))
867 return RX_CONTINUE;
868
869 cs = rx->sta->cipher_scheme;
870
871 data_len = rx->skb->len - hdrlen - cs->hdr_len;
872
873 if (data_len < 0)
874 return RX_DROP_UNUSABLE;
875
876 if (ieee80211_is_data_qos(hdr->frame_control))
877 qos_tid = ieee80211_get_tid(hdr);
878 else
879 qos_tid = 0;
880
881 if (skb_linearize(rx->skb))
882 return RX_DROP_UNUSABLE;
883
884 hdr = (struct ieee80211_hdr *)rx->skb->data;
885
886 rx_pn = key->u.gen.rx_pn[qos_tid];
887 skb_pn = rx->skb->data + hdrlen + cs->pn_off;
888
889 if (ieee80211_crypto_cs_pn_compare(skb_pn, rx_pn, cs->pn_len) <= 0)
890 return RX_DROP_UNUSABLE;
891
892 memcpy(rx_pn, skb_pn, cs->pn_len);
893
894 /* remove security header and MIC */
895 if (pskb_trim(rx->skb, rx->skb->len - cs->mic_len))
896 return RX_DROP_UNUSABLE;
897
898 memmove(rx->skb->data + cs->hdr_len, rx->skb->data, hdrlen);
899 skb_pull(rx->skb, cs->hdr_len);
900
901 return RX_CONTINUE;
902}
903
904static void bip_aad(struct sk_buff *skb, u8 *aad)
905{
906 __le16 mask_fc;
907 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
908
909 /* BIP AAD: FC(masked) || A1 || A2 || A3 */
910
911 /* FC type/subtype */
912 /* Mask FC Retry, PwrMgt, MoreData flags to zero */
913 mask_fc = hdr->frame_control;
914 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM |
915 IEEE80211_FCTL_MOREDATA);
916 put_unaligned(mask_fc, (__le16 *) &aad[0]);
917 /* A1 || A2 || A3 */
918 memcpy(aad + 2, &hdr->addr1, 3 * ETH_ALEN);
919}
920
921
922static inline void bip_ipn_set64(u8 *d, u64 pn)
923{
924 *d++ = pn;
925 *d++ = pn >> 8;
926 *d++ = pn >> 16;
927 *d++ = pn >> 24;
928 *d++ = pn >> 32;
929 *d = pn >> 40;
930}
931
932static inline void bip_ipn_swap(u8 *d, const u8 *s)
933{
934 *d++ = s[5];
935 *d++ = s[4];
936 *d++ = s[3];
937 *d++ = s[2];
938 *d++ = s[1];
939 *d = s[0];
940}
941
942
943ieee80211_tx_result
944ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
945{
946 struct sk_buff *skb;
947 struct ieee80211_tx_info *info;
948 struct ieee80211_key *key = tx->key;
949 struct ieee80211_mmie *mmie;
950 u8 aad[20];
951 u64 pn64;
952
953 if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
954 return TX_DROP;
955
956 skb = skb_peek(&tx->skbs);
957
958 info = IEEE80211_SKB_CB(skb);
959
960 if (info->control.hw_key &&
961 !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE))
962 return TX_CONTINUE;
963
964 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
965 return TX_DROP;
966
967 mmie = skb_put(skb, sizeof(*mmie));
968 mmie->element_id = WLAN_EID_MMIE;
969 mmie->length = sizeof(*mmie) - 2;
970 mmie->key_id = cpu_to_le16(key->conf.keyidx);
971
972 /* PN = PN + 1 */
973 pn64 = atomic64_inc_return(&key->conf.tx_pn);
974
975 bip_ipn_set64(mmie->sequence_number, pn64);
976
977 if (info->control.hw_key)
978 return TX_CONTINUE;
979
980 bip_aad(skb, aad);
981
982 /*
983 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
984 */
985 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
986 skb->data + 24, skb->len - 24, mmie->mic);
987
988 return TX_CONTINUE;
989}
990
991ieee80211_tx_result
992ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx)
993{
994 struct sk_buff *skb;
995 struct ieee80211_tx_info *info;
996 struct ieee80211_key *key = tx->key;
997 struct ieee80211_mmie_16 *mmie;
998 u8 aad[20];
999 u64 pn64;
1000
1001 if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
1002 return TX_DROP;
1003
1004 skb = skb_peek(&tx->skbs);
1005
1006 info = IEEE80211_SKB_CB(skb);
1007
1008 if (info->control.hw_key)
1009 return TX_CONTINUE;
1010
1011 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
1012 return TX_DROP;
1013
1014 mmie = skb_put(skb, sizeof(*mmie));
1015 mmie->element_id = WLAN_EID_MMIE;
1016 mmie->length = sizeof(*mmie) - 2;
1017 mmie->key_id = cpu_to_le16(key->conf.keyidx);
1018
1019 /* PN = PN + 1 */
1020 pn64 = atomic64_inc_return(&key->conf.tx_pn);
1021
1022 bip_ipn_set64(mmie->sequence_number, pn64);
1023
1024 bip_aad(skb, aad);
1025
1026 /* MIC = AES-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128)
1027 */
1028 ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1029 skb->data + 24, skb->len - 24, mmie->mic);
1030
1031 return TX_CONTINUE;
1032}
1033
1034ieee80211_rx_result
1035ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
1036{
1037 struct sk_buff *skb = rx->skb;
1038 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1039 struct ieee80211_key *key = rx->key;
1040 struct ieee80211_mmie *mmie;
1041 u8 aad[20], mic[8], ipn[6];
1042 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1043
1044 if (!ieee80211_is_mgmt(hdr->frame_control))
1045 return RX_CONTINUE;
1046
1047 /* management frames are already linear */
1048
1049 if (skb->len < 24 + sizeof(*mmie))
1050 return RX_DROP_UNUSABLE;
1051
1052 mmie = (struct ieee80211_mmie *)
1053 (skb->data + skb->len - sizeof(*mmie));
1054 if (mmie->element_id != WLAN_EID_MMIE ||
1055 mmie->length != sizeof(*mmie) - 2)
1056 return RX_DROP_UNUSABLE; /* Invalid MMIE */
1057
1058 bip_ipn_swap(ipn, mmie->sequence_number);
1059
1060 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1061 key->u.aes_cmac.replays++;
1062 return RX_DROP_UNUSABLE;
1063 }
1064
1065 if (!(status->flag & RX_FLAG_DECRYPTED)) {
1066 /* hardware didn't decrypt/verify MIC */
1067 bip_aad(skb, aad);
1068 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
1069 skb->data + 24, skb->len - 24, mic);
1070 if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1071 key->u.aes_cmac.icverrors++;
1072 return RX_DROP_UNUSABLE;
1073 }
1074 }
1075
1076 memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1077
1078 /* Remove MMIE */
1079 skb_trim(skb, skb->len - sizeof(*mmie));
1080
1081 return RX_CONTINUE;
1082}
1083
1084ieee80211_rx_result
1085ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx)
1086{
1087 struct sk_buff *skb = rx->skb;
1088 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1089 struct ieee80211_key *key = rx->key;
1090 struct ieee80211_mmie_16 *mmie;
1091 u8 aad[20], mic[16], ipn[6];
1092 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1093
1094 if (!ieee80211_is_mgmt(hdr->frame_control))
1095 return RX_CONTINUE;
1096
1097 /* management frames are already linear */
1098
1099 if (skb->len < 24 + sizeof(*mmie))
1100 return RX_DROP_UNUSABLE;
1101
1102 mmie = (struct ieee80211_mmie_16 *)
1103 (skb->data + skb->len - sizeof(*mmie));
1104 if (mmie->element_id != WLAN_EID_MMIE ||
1105 mmie->length != sizeof(*mmie) - 2)
1106 return RX_DROP_UNUSABLE; /* Invalid MMIE */
1107
1108 bip_ipn_swap(ipn, mmie->sequence_number);
1109
1110 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1111 key->u.aes_cmac.replays++;
1112 return RX_DROP_UNUSABLE;
1113 }
1114
1115 if (!(status->flag & RX_FLAG_DECRYPTED)) {
1116 /* hardware didn't decrypt/verify MIC */
1117 bip_aad(skb, aad);
1118 ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1119 skb->data + 24, skb->len - 24, mic);
1120 if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1121 key->u.aes_cmac.icverrors++;
1122 return RX_DROP_UNUSABLE;
1123 }
1124 }
1125
1126 memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1127
1128 /* Remove MMIE */
1129 skb_trim(skb, skb->len - sizeof(*mmie));
1130
1131 return RX_CONTINUE;
1132}
1133
1134ieee80211_tx_result
1135ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data *tx)
1136{
1137 struct sk_buff *skb;
1138 struct ieee80211_tx_info *info;
1139 struct ieee80211_key *key = tx->key;
1140 struct ieee80211_mmie_16 *mmie;
1141 struct ieee80211_hdr *hdr;
1142 u8 aad[GMAC_AAD_LEN];
1143 u64 pn64;
1144 u8 nonce[GMAC_NONCE_LEN];
1145
1146 if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
1147 return TX_DROP;
1148
1149 skb = skb_peek(&tx->skbs);
1150
1151 info = IEEE80211_SKB_CB(skb);
1152
1153 if (info->control.hw_key)
1154 return TX_CONTINUE;
1155
1156 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
1157 return TX_DROP;
1158
1159 mmie = skb_put(skb, sizeof(*mmie));
1160 mmie->element_id = WLAN_EID_MMIE;
1161 mmie->length = sizeof(*mmie) - 2;
1162 mmie->key_id = cpu_to_le16(key->conf.keyidx);
1163
1164 /* PN = PN + 1 */
1165 pn64 = atomic64_inc_return(&key->conf.tx_pn);
1166
1167 bip_ipn_set64(mmie->sequence_number, pn64);
1168
1169 bip_aad(skb, aad);
1170
1171 hdr = (struct ieee80211_hdr *)skb->data;
1172 memcpy(nonce, hdr->addr2, ETH_ALEN);
1173 bip_ipn_swap(nonce + ETH_ALEN, mmie->sequence_number);
1174
1175 /* MIC = AES-GMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */
1176 if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1177 skb->data + 24, skb->len - 24, mmie->mic) < 0)
1178 return TX_DROP;
1179
1180 return TX_CONTINUE;
1181}
1182
1183ieee80211_rx_result
1184ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data *rx)
1185{
1186 struct sk_buff *skb = rx->skb;
1187 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1188 struct ieee80211_key *key = rx->key;
1189 struct ieee80211_mmie_16 *mmie;
1190 u8 aad[GMAC_AAD_LEN], *mic, ipn[6], nonce[GMAC_NONCE_LEN];
1191 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1192
1193 if (!ieee80211_is_mgmt(hdr->frame_control))
1194 return RX_CONTINUE;
1195
1196 /* management frames are already linear */
1197
1198 if (skb->len < 24 + sizeof(*mmie))
1199 return RX_DROP_UNUSABLE;
1200
1201 mmie = (struct ieee80211_mmie_16 *)
1202 (skb->data + skb->len - sizeof(*mmie));
1203 if (mmie->element_id != WLAN_EID_MMIE ||
1204 mmie->length != sizeof(*mmie) - 2)
1205 return RX_DROP_UNUSABLE; /* Invalid MMIE */
1206
1207 bip_ipn_swap(ipn, mmie->sequence_number);
1208
1209 if (memcmp(ipn, key->u.aes_gmac.rx_pn, 6) <= 0) {
1210 key->u.aes_gmac.replays++;
1211 return RX_DROP_UNUSABLE;
1212 }
1213
1214 if (!(status->flag & RX_FLAG_DECRYPTED)) {
1215 /* hardware didn't decrypt/verify MIC */
1216 bip_aad(skb, aad);
1217
1218 memcpy(nonce, hdr->addr2, ETH_ALEN);
1219 memcpy(nonce + ETH_ALEN, ipn, 6);
1220
1221 mic = kmalloc(GMAC_MIC_LEN, GFP_ATOMIC);
1222 if (!mic)
1223 return RX_DROP_UNUSABLE;
1224 if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1225 skb->data + 24, skb->len - 24,
1226 mic) < 0 ||
1227 crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1228 key->u.aes_gmac.icverrors++;
1229 kfree(mic);
1230 return RX_DROP_UNUSABLE;
1231 }
1232 kfree(mic);
1233 }
1234
1235 memcpy(key->u.aes_gmac.rx_pn, ipn, 6);
1236
1237 /* Remove MMIE */
1238 skb_trim(skb, skb->len - sizeof(*mmie));
1239
1240 return RX_CONTINUE;
1241}
1242
1243ieee80211_tx_result
1244ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx)
1245{
1246 struct sk_buff *skb;
1247 struct ieee80211_tx_info *info = NULL;
1248 ieee80211_tx_result res;
1249
1250 skb_queue_walk(&tx->skbs, skb) {
1251 info = IEEE80211_SKB_CB(skb);
1252
1253 /* handle hw-only algorithm */
1254 if (!info->control.hw_key)
1255 return TX_DROP;
1256
1257 if (tx->key->flags & KEY_FLAG_CIPHER_SCHEME) {
1258 res = ieee80211_crypto_cs_encrypt(tx, skb);
1259 if (res != TX_CONTINUE)
1260 return res;
1261 }
1262 }
1263
1264 ieee80211_tx_set_protected(tx);
1265
1266 return TX_CONTINUE;
1267}
1268
1269ieee80211_rx_result
1270ieee80211_crypto_hw_decrypt(struct ieee80211_rx_data *rx)
1271{
1272 if (rx->sta && rx->sta->cipher_scheme)
1273 return ieee80211_crypto_cs_decrypt(rx);
1274
1275 return RX_DROP_UNUSABLE;
1276}
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
27ieee80211_tx_result
28ieee80211_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
81ieee80211_rx_result
82ieee80211_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
155update_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
162mic_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
175static 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
234ieee80211_tx_result
235ieee80211_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
250ieee80211_rx_result
251ieee80211_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
300static 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
373static 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
386static 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
397static 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
466ieee80211_tx_result
467ieee80211_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
482ieee80211_rx_result
483ieee80211_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
546static 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
559static 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
569static 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
580ieee80211_tx_result
581ieee80211_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
625ieee80211_rx_result
626ieee80211_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
675ieee80211_tx_result
676ieee80211_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}