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
29 ieee80211_tx_result
ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data * tx)30 ieee80211_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
94 ieee80211_rx_result
ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data * rx)95 ieee80211_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
169 update_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
176 mic_fail:
177 rx->key->u.tkip.mic_failures++;
178
179 mic_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
tkip_encrypt_skb(struct ieee80211_tx_data * tx,struct sk_buff * skb)194 static 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
248 ieee80211_tx_result
ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data * tx)249 ieee80211_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
264 ieee80211_rx_result
ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data * rx)265 ieee80211_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 /*
315 * Calculate AAD for CCMP/GCMP, returning qos_tid since we
316 * need that in CCMP also for b_0.
317 */
ccmp_gcmp_aad(struct sk_buff * skb,u8 * aad)318 static u8 ccmp_gcmp_aad(struct sk_buff *skb, u8 *aad)
319 {
320 struct ieee80211_hdr *hdr = (void *)skb->data;
321 __le16 mask_fc;
322 int a4_included, mgmt;
323 u8 qos_tid;
324 u16 len_a = 22;
325
326 /*
327 * Mask FC: zero subtype b4 b5 b6 (if not mgmt)
328 * Retry, PwrMgt, MoreData, Order (if Qos Data); set Protected
329 */
330 mgmt = ieee80211_is_mgmt(hdr->frame_control);
331 mask_fc = hdr->frame_control;
332 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
333 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
334 if (!mgmt)
335 mask_fc &= ~cpu_to_le16(0x0070);
336 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
337
338 a4_included = ieee80211_has_a4(hdr->frame_control);
339 if (a4_included)
340 len_a += 6;
341
342 if (ieee80211_is_data_qos(hdr->frame_control)) {
343 qos_tid = ieee80211_get_tid(hdr);
344 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_ORDER);
345 len_a += 2;
346 } else {
347 qos_tid = 0;
348 }
349
350 /* AAD (extra authenticate-only data) / masked 802.11 header
351 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
352 put_unaligned_be16(len_a, &aad[0]);
353 put_unaligned(mask_fc, (__le16 *)&aad[2]);
354 memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
355
356 /* Mask Seq#, leave Frag# */
357 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
358 aad[23] = 0;
359
360 if (a4_included) {
361 memcpy(&aad[24], hdr->addr4, ETH_ALEN);
362 aad[30] = qos_tid;
363 aad[31] = 0;
364 } else {
365 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
366 aad[24] = qos_tid;
367 }
368
369 return qos_tid;
370 }
371
ccmp_special_blocks(struct sk_buff * skb,u8 * pn,u8 * b_0,u8 * aad)372 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad)
373 {
374 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
375 u8 qos_tid = ccmp_gcmp_aad(skb, aad);
376
377 /* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC
378 * mode authentication are not allowed to collide, yet both are derived
379 * from this vector b_0. We only set L := 1 here to indicate that the
380 * data size can be represented in (L+1) bytes. The CCM layer will take
381 * care of storing the data length in the top (L+1) bytes and setting
382 * and clearing the other bits as is required to derive the two IVs.
383 */
384 b_0[0] = 0x1;
385
386 /* Nonce: Nonce Flags | A2 | PN
387 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)
388 */
389 b_0[1] = qos_tid | (ieee80211_is_mgmt(hdr->frame_control) << 4);
390 memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
391 memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN);
392 }
393
ccmp_pn2hdr(u8 * hdr,u8 * pn,int key_id)394 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
395 {
396 hdr[0] = pn[5];
397 hdr[1] = pn[4];
398 hdr[2] = 0;
399 hdr[3] = 0x20 | (key_id << 6);
400 hdr[4] = pn[3];
401 hdr[5] = pn[2];
402 hdr[6] = pn[1];
403 hdr[7] = pn[0];
404 }
405
406
ccmp_hdr2pn(u8 * pn,u8 * hdr)407 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr)
408 {
409 pn[0] = hdr[7];
410 pn[1] = hdr[6];
411 pn[2] = hdr[5];
412 pn[3] = hdr[4];
413 pn[4] = hdr[1];
414 pn[5] = hdr[0];
415 }
416
417
ccmp_encrypt_skb(struct ieee80211_tx_data * tx,struct sk_buff * skb,unsigned int mic_len)418 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb,
419 unsigned int mic_len)
420 {
421 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
422 struct ieee80211_key *key = tx->key;
423 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
424 int hdrlen, len, tail;
425 u8 *pos;
426 u8 pn[6];
427 u64 pn64;
428 u8 aad[CCM_AAD_LEN];
429 u8 b_0[AES_BLOCK_SIZE];
430
431 if (info->control.hw_key &&
432 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
433 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
434 !((info->control.hw_key->flags &
435 IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
436 ieee80211_is_mgmt(hdr->frame_control))) {
437 /*
438 * hwaccel has no need for preallocated room for CCMP
439 * header or MIC fields
440 */
441 return 0;
442 }
443
444 hdrlen = ieee80211_hdrlen(hdr->frame_control);
445 len = skb->len - hdrlen;
446
447 if (info->control.hw_key)
448 tail = 0;
449 else
450 tail = mic_len;
451
452 if (WARN_ON(skb_tailroom(skb) < tail ||
453 skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN))
454 return -1;
455
456 pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN);
457 memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen);
458
459 /* the HW only needs room for the IV, but not the actual IV */
460 if (info->control.hw_key &&
461 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
462 return 0;
463
464 pos += hdrlen;
465
466 pn64 = atomic64_inc_return(&key->conf.tx_pn);
467
468 pn[5] = pn64;
469 pn[4] = pn64 >> 8;
470 pn[3] = pn64 >> 16;
471 pn[2] = pn64 >> 24;
472 pn[1] = pn64 >> 32;
473 pn[0] = pn64 >> 40;
474
475 ccmp_pn2hdr(pos, pn, key->conf.keyidx);
476
477 /* hwaccel - with software CCMP header */
478 if (info->control.hw_key)
479 return 0;
480
481 pos += IEEE80211_CCMP_HDR_LEN;
482 ccmp_special_blocks(skb, pn, b_0, aad);
483 return ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,
484 skb_put(skb, mic_len));
485 }
486
487
488 ieee80211_tx_result
ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data * tx,unsigned int mic_len)489 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx,
490 unsigned int mic_len)
491 {
492 struct sk_buff *skb;
493
494 ieee80211_tx_set_protected(tx);
495
496 skb_queue_walk(&tx->skbs, skb) {
497 if (ccmp_encrypt_skb(tx, skb, mic_len) < 0)
498 return TX_DROP;
499 }
500
501 return TX_CONTINUE;
502 }
503
504
505 ieee80211_rx_result
ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data * rx,unsigned int mic_len)506 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
507 unsigned int mic_len)
508 {
509 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
510 int hdrlen;
511 struct ieee80211_key *key = rx->key;
512 struct sk_buff *skb = rx->skb;
513 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
514 u8 pn[IEEE80211_CCMP_PN_LEN];
515 int data_len;
516 int queue;
517
518 hdrlen = ieee80211_hdrlen(hdr->frame_control);
519
520 if (!ieee80211_is_data(hdr->frame_control) &&
521 !ieee80211_is_robust_mgmt_frame(skb))
522 return RX_CONTINUE;
523
524 if (status->flag & RX_FLAG_DECRYPTED) {
525 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_CCMP_HDR_LEN))
526 return RX_DROP_UNUSABLE;
527 if (status->flag & RX_FLAG_MIC_STRIPPED)
528 mic_len = 0;
529 } else {
530 if (skb_linearize(rx->skb))
531 return RX_DROP_UNUSABLE;
532 }
533
534 /* reload hdr - skb might have been reallocated */
535 hdr = (void *)rx->skb->data;
536
537 data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - mic_len;
538 if (!rx->sta || data_len < 0)
539 return RX_DROP_UNUSABLE;
540
541 if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
542 int res;
543
544 ccmp_hdr2pn(pn, skb->data + hdrlen);
545
546 queue = rx->security_idx;
547
548 res = memcmp(pn, key->u.ccmp.rx_pn[queue],
549 IEEE80211_CCMP_PN_LEN);
550 if (res < 0 ||
551 (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
552 key->u.ccmp.replays++;
553 return RX_DROP_UNUSABLE;
554 }
555
556 if (!(status->flag & RX_FLAG_DECRYPTED)) {
557 u8 aad[2 * AES_BLOCK_SIZE];
558 u8 b_0[AES_BLOCK_SIZE];
559 /* hardware didn't decrypt/verify MIC */
560 ccmp_special_blocks(skb, pn, b_0, aad);
561
562 if (ieee80211_aes_ccm_decrypt(
563 key->u.ccmp.tfm, b_0, aad,
564 skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN,
565 data_len,
566 skb->data + skb->len - mic_len))
567 return RX_DROP_UNUSABLE;
568 }
569
570 memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN);
571 if (unlikely(ieee80211_is_frag(hdr)))
572 memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN);
573 }
574
575 /* Remove CCMP header and MIC */
576 if (pskb_trim(skb, skb->len - mic_len))
577 return RX_DROP_UNUSABLE;
578 memmove(skb->data + IEEE80211_CCMP_HDR_LEN, skb->data, hdrlen);
579 skb_pull(skb, IEEE80211_CCMP_HDR_LEN);
580
581 return RX_CONTINUE;
582 }
583
gcmp_special_blocks(struct sk_buff * skb,u8 * pn,u8 * j_0,u8 * aad)584 static void gcmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *j_0, u8 *aad)
585 {
586 struct ieee80211_hdr *hdr = (void *)skb->data;
587
588 memcpy(j_0, hdr->addr2, ETH_ALEN);
589 memcpy(&j_0[ETH_ALEN], pn, IEEE80211_GCMP_PN_LEN);
590 j_0[13] = 0;
591 j_0[14] = 0;
592 j_0[AES_BLOCK_SIZE - 1] = 0x01;
593
594 ccmp_gcmp_aad(skb, aad);
595 }
596
gcmp_pn2hdr(u8 * hdr,const u8 * pn,int key_id)597 static inline void gcmp_pn2hdr(u8 *hdr, const u8 *pn, int key_id)
598 {
599 hdr[0] = pn[5];
600 hdr[1] = pn[4];
601 hdr[2] = 0;
602 hdr[3] = 0x20 | (key_id << 6);
603 hdr[4] = pn[3];
604 hdr[5] = pn[2];
605 hdr[6] = pn[1];
606 hdr[7] = pn[0];
607 }
608
gcmp_hdr2pn(u8 * pn,const u8 * hdr)609 static inline void gcmp_hdr2pn(u8 *pn, const u8 *hdr)
610 {
611 pn[0] = hdr[7];
612 pn[1] = hdr[6];
613 pn[2] = hdr[5];
614 pn[3] = hdr[4];
615 pn[4] = hdr[1];
616 pn[5] = hdr[0];
617 }
618
gcmp_encrypt_skb(struct ieee80211_tx_data * tx,struct sk_buff * skb)619 static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
620 {
621 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
622 struct ieee80211_key *key = tx->key;
623 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
624 int hdrlen, len, tail;
625 u8 *pos;
626 u8 pn[6];
627 u64 pn64;
628 u8 aad[GCM_AAD_LEN];
629 u8 j_0[AES_BLOCK_SIZE];
630
631 if (info->control.hw_key &&
632 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
633 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
634 !((info->control.hw_key->flags &
635 IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
636 ieee80211_is_mgmt(hdr->frame_control))) {
637 /* hwaccel has no need for preallocated room for GCMP
638 * header or MIC fields
639 */
640 return 0;
641 }
642
643 hdrlen = ieee80211_hdrlen(hdr->frame_control);
644 len = skb->len - hdrlen;
645
646 if (info->control.hw_key)
647 tail = 0;
648 else
649 tail = IEEE80211_GCMP_MIC_LEN;
650
651 if (WARN_ON(skb_tailroom(skb) < tail ||
652 skb_headroom(skb) < IEEE80211_GCMP_HDR_LEN))
653 return -1;
654
655 pos = skb_push(skb, IEEE80211_GCMP_HDR_LEN);
656 memmove(pos, pos + IEEE80211_GCMP_HDR_LEN, hdrlen);
657 skb_set_network_header(skb, skb_network_offset(skb) +
658 IEEE80211_GCMP_HDR_LEN);
659
660 /* the HW only needs room for the IV, but not the actual IV */
661 if (info->control.hw_key &&
662 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
663 return 0;
664
665 pos += hdrlen;
666
667 pn64 = atomic64_inc_return(&key->conf.tx_pn);
668
669 pn[5] = pn64;
670 pn[4] = pn64 >> 8;
671 pn[3] = pn64 >> 16;
672 pn[2] = pn64 >> 24;
673 pn[1] = pn64 >> 32;
674 pn[0] = pn64 >> 40;
675
676 gcmp_pn2hdr(pos, pn, key->conf.keyidx);
677
678 /* hwaccel - with software GCMP header */
679 if (info->control.hw_key)
680 return 0;
681
682 pos += IEEE80211_GCMP_HDR_LEN;
683 gcmp_special_blocks(skb, pn, j_0, aad);
684 return ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len,
685 skb_put(skb, IEEE80211_GCMP_MIC_LEN));
686 }
687
688 ieee80211_tx_result
ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data * tx)689 ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data *tx)
690 {
691 struct sk_buff *skb;
692
693 ieee80211_tx_set_protected(tx);
694
695 skb_queue_walk(&tx->skbs, skb) {
696 if (gcmp_encrypt_skb(tx, skb) < 0)
697 return TX_DROP;
698 }
699
700 return TX_CONTINUE;
701 }
702
703 ieee80211_rx_result
ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data * rx)704 ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx)
705 {
706 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
707 int hdrlen;
708 struct ieee80211_key *key = rx->key;
709 struct sk_buff *skb = rx->skb;
710 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
711 u8 pn[IEEE80211_GCMP_PN_LEN];
712 int data_len, queue, mic_len = IEEE80211_GCMP_MIC_LEN;
713
714 hdrlen = ieee80211_hdrlen(hdr->frame_control);
715
716 if (!ieee80211_is_data(hdr->frame_control) &&
717 !ieee80211_is_robust_mgmt_frame(skb))
718 return RX_CONTINUE;
719
720 if (status->flag & RX_FLAG_DECRYPTED) {
721 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN))
722 return RX_DROP_UNUSABLE;
723 if (status->flag & RX_FLAG_MIC_STRIPPED)
724 mic_len = 0;
725 } else {
726 if (skb_linearize(rx->skb))
727 return RX_DROP_UNUSABLE;
728 }
729
730 /* reload hdr - skb might have been reallocated */
731 hdr = (void *)rx->skb->data;
732
733 data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - mic_len;
734 if (!rx->sta || data_len < 0)
735 return RX_DROP_UNUSABLE;
736
737 if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
738 int res;
739
740 gcmp_hdr2pn(pn, skb->data + hdrlen);
741
742 queue = rx->security_idx;
743
744 res = memcmp(pn, key->u.gcmp.rx_pn[queue],
745 IEEE80211_GCMP_PN_LEN);
746 if (res < 0 ||
747 (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
748 key->u.gcmp.replays++;
749 return RX_DROP_UNUSABLE;
750 }
751
752 if (!(status->flag & RX_FLAG_DECRYPTED)) {
753 u8 aad[2 * AES_BLOCK_SIZE];
754 u8 j_0[AES_BLOCK_SIZE];
755 /* hardware didn't decrypt/verify MIC */
756 gcmp_special_blocks(skb, pn, j_0, aad);
757
758 if (ieee80211_aes_gcm_decrypt(
759 key->u.gcmp.tfm, j_0, aad,
760 skb->data + hdrlen + IEEE80211_GCMP_HDR_LEN,
761 data_len,
762 skb->data + skb->len -
763 IEEE80211_GCMP_MIC_LEN))
764 return RX_DROP_UNUSABLE;
765 }
766
767 memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN);
768 if (unlikely(ieee80211_is_frag(hdr)))
769 memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN);
770 }
771
772 /* Remove GCMP header and MIC */
773 if (pskb_trim(skb, skb->len - mic_len))
774 return RX_DROP_UNUSABLE;
775 memmove(skb->data + IEEE80211_GCMP_HDR_LEN, skb->data, hdrlen);
776 skb_pull(skb, IEEE80211_GCMP_HDR_LEN);
777
778 return RX_CONTINUE;
779 }
780
781 static ieee80211_tx_result
ieee80211_crypto_cs_encrypt(struct ieee80211_tx_data * tx,struct sk_buff * skb)782 ieee80211_crypto_cs_encrypt(struct ieee80211_tx_data *tx,
783 struct sk_buff *skb)
784 {
785 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
786 struct ieee80211_key *key = tx->key;
787 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
788 int hdrlen;
789 u8 *pos, iv_len = key->conf.iv_len;
790
791 if (info->control.hw_key &&
792 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
793 /* hwaccel has no need for preallocated head room */
794 return TX_CONTINUE;
795 }
796
797 if (unlikely(skb_headroom(skb) < iv_len &&
798 pskb_expand_head(skb, iv_len, 0, GFP_ATOMIC)))
799 return TX_DROP;
800
801 hdrlen = ieee80211_hdrlen(hdr->frame_control);
802
803 pos = skb_push(skb, iv_len);
804 memmove(pos, pos + iv_len, hdrlen);
805
806 return TX_CONTINUE;
807 }
808
ieee80211_crypto_cs_pn_compare(u8 * pn1,u8 * pn2,int len)809 static inline int ieee80211_crypto_cs_pn_compare(u8 *pn1, u8 *pn2, int len)
810 {
811 int i;
812
813 /* pn is little endian */
814 for (i = len - 1; i >= 0; i--) {
815 if (pn1[i] < pn2[i])
816 return -1;
817 else if (pn1[i] > pn2[i])
818 return 1;
819 }
820
821 return 0;
822 }
823
824 static ieee80211_rx_result
ieee80211_crypto_cs_decrypt(struct ieee80211_rx_data * rx)825 ieee80211_crypto_cs_decrypt(struct ieee80211_rx_data *rx)
826 {
827 struct ieee80211_key *key = rx->key;
828 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
829 const struct ieee80211_cipher_scheme *cs = NULL;
830 int hdrlen = ieee80211_hdrlen(hdr->frame_control);
831 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
832 int data_len;
833 u8 *rx_pn;
834 u8 *skb_pn;
835 u8 qos_tid;
836
837 if (!rx->sta || !rx->sta->cipher_scheme ||
838 !(status->flag & RX_FLAG_DECRYPTED))
839 return RX_DROP_UNUSABLE;
840
841 if (!ieee80211_is_data(hdr->frame_control))
842 return RX_CONTINUE;
843
844 cs = rx->sta->cipher_scheme;
845
846 data_len = rx->skb->len - hdrlen - cs->hdr_len;
847
848 if (data_len < 0)
849 return RX_DROP_UNUSABLE;
850
851 if (ieee80211_is_data_qos(hdr->frame_control))
852 qos_tid = ieee80211_get_tid(hdr);
853 else
854 qos_tid = 0;
855
856 if (skb_linearize(rx->skb))
857 return RX_DROP_UNUSABLE;
858
859 rx_pn = key->u.gen.rx_pn[qos_tid];
860 skb_pn = rx->skb->data + hdrlen + cs->pn_off;
861
862 if (ieee80211_crypto_cs_pn_compare(skb_pn, rx_pn, cs->pn_len) <= 0)
863 return RX_DROP_UNUSABLE;
864
865 memcpy(rx_pn, skb_pn, cs->pn_len);
866
867 /* remove security header and MIC */
868 if (pskb_trim(rx->skb, rx->skb->len - cs->mic_len))
869 return RX_DROP_UNUSABLE;
870
871 memmove(rx->skb->data + cs->hdr_len, rx->skb->data, hdrlen);
872 skb_pull(rx->skb, cs->hdr_len);
873
874 return RX_CONTINUE;
875 }
876
bip_aad(struct sk_buff * skb,u8 * aad)877 static void bip_aad(struct sk_buff *skb, u8 *aad)
878 {
879 __le16 mask_fc;
880 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
881
882 /* BIP AAD: FC(masked) || A1 || A2 || A3 */
883
884 /* FC type/subtype */
885 /* Mask FC Retry, PwrMgt, MoreData flags to zero */
886 mask_fc = hdr->frame_control;
887 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM |
888 IEEE80211_FCTL_MOREDATA);
889 put_unaligned(mask_fc, (__le16 *) &aad[0]);
890 /* A1 || A2 || A3 */
891 memcpy(aad + 2, &hdr->addr1, 3 * ETH_ALEN);
892 }
893
894
bip_ipn_set64(u8 * d,u64 pn)895 static inline void bip_ipn_set64(u8 *d, u64 pn)
896 {
897 *d++ = pn;
898 *d++ = pn >> 8;
899 *d++ = pn >> 16;
900 *d++ = pn >> 24;
901 *d++ = pn >> 32;
902 *d = pn >> 40;
903 }
904
bip_ipn_swap(u8 * d,const u8 * s)905 static inline void bip_ipn_swap(u8 *d, const u8 *s)
906 {
907 *d++ = s[5];
908 *d++ = s[4];
909 *d++ = s[3];
910 *d++ = s[2];
911 *d++ = s[1];
912 *d = s[0];
913 }
914
915
916 ieee80211_tx_result
ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data * tx)917 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
918 {
919 struct sk_buff *skb;
920 struct ieee80211_tx_info *info;
921 struct ieee80211_key *key = tx->key;
922 struct ieee80211_mmie *mmie;
923 u8 aad[20];
924 u64 pn64;
925
926 if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
927 return TX_DROP;
928
929 skb = skb_peek(&tx->skbs);
930
931 info = IEEE80211_SKB_CB(skb);
932
933 if (info->control.hw_key &&
934 !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE))
935 return TX_CONTINUE;
936
937 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
938 return TX_DROP;
939
940 mmie = skb_put(skb, sizeof(*mmie));
941 mmie->element_id = WLAN_EID_MMIE;
942 mmie->length = sizeof(*mmie) - 2;
943 mmie->key_id = cpu_to_le16(key->conf.keyidx);
944
945 /* PN = PN + 1 */
946 pn64 = atomic64_inc_return(&key->conf.tx_pn);
947
948 bip_ipn_set64(mmie->sequence_number, pn64);
949
950 if (info->control.hw_key)
951 return TX_CONTINUE;
952
953 bip_aad(skb, aad);
954
955 /*
956 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
957 */
958 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
959 skb->data + 24, skb->len - 24, mmie->mic);
960
961 return TX_CONTINUE;
962 }
963
964 ieee80211_tx_result
ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data * tx)965 ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx)
966 {
967 struct sk_buff *skb;
968 struct ieee80211_tx_info *info;
969 struct ieee80211_key *key = tx->key;
970 struct ieee80211_mmie_16 *mmie;
971 u8 aad[20];
972 u64 pn64;
973
974 if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
975 return TX_DROP;
976
977 skb = skb_peek(&tx->skbs);
978
979 info = IEEE80211_SKB_CB(skb);
980
981 if (info->control.hw_key)
982 return TX_CONTINUE;
983
984 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
985 return TX_DROP;
986
987 mmie = skb_put(skb, sizeof(*mmie));
988 mmie->element_id = WLAN_EID_MMIE;
989 mmie->length = sizeof(*mmie) - 2;
990 mmie->key_id = cpu_to_le16(key->conf.keyidx);
991
992 /* PN = PN + 1 */
993 pn64 = atomic64_inc_return(&key->conf.tx_pn);
994
995 bip_ipn_set64(mmie->sequence_number, pn64);
996
997 bip_aad(skb, aad);
998
999 /* MIC = AES-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128)
1000 */
1001 ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1002 skb->data + 24, skb->len - 24, mmie->mic);
1003
1004 return TX_CONTINUE;
1005 }
1006
1007 ieee80211_rx_result
ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data * rx)1008 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
1009 {
1010 struct sk_buff *skb = rx->skb;
1011 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1012 struct ieee80211_key *key = rx->key;
1013 struct ieee80211_mmie *mmie;
1014 u8 aad[20], mic[8], ipn[6];
1015 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1016
1017 if (!ieee80211_is_mgmt(hdr->frame_control))
1018 return RX_CONTINUE;
1019
1020 /* management frames are already linear */
1021
1022 if (skb->len < 24 + sizeof(*mmie))
1023 return RX_DROP_UNUSABLE;
1024
1025 mmie = (struct ieee80211_mmie *)
1026 (skb->data + skb->len - sizeof(*mmie));
1027 if (mmie->element_id != WLAN_EID_MMIE ||
1028 mmie->length != sizeof(*mmie) - 2)
1029 return RX_DROP_UNUSABLE; /* Invalid MMIE */
1030
1031 bip_ipn_swap(ipn, mmie->sequence_number);
1032
1033 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1034 key->u.aes_cmac.replays++;
1035 return RX_DROP_UNUSABLE;
1036 }
1037
1038 if (!(status->flag & RX_FLAG_DECRYPTED)) {
1039 /* hardware didn't decrypt/verify MIC */
1040 bip_aad(skb, aad);
1041 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
1042 skb->data + 24, skb->len - 24, mic);
1043 if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1044 key->u.aes_cmac.icverrors++;
1045 return RX_DROP_UNUSABLE;
1046 }
1047 }
1048
1049 memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1050
1051 /* Remove MMIE */
1052 skb_trim(skb, skb->len - sizeof(*mmie));
1053
1054 return RX_CONTINUE;
1055 }
1056
1057 ieee80211_rx_result
ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data * rx)1058 ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx)
1059 {
1060 struct sk_buff *skb = rx->skb;
1061 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1062 struct ieee80211_key *key = rx->key;
1063 struct ieee80211_mmie_16 *mmie;
1064 u8 aad[20], mic[16], ipn[6];
1065 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1066
1067 if (!ieee80211_is_mgmt(hdr->frame_control))
1068 return RX_CONTINUE;
1069
1070 /* management frames are already linear */
1071
1072 if (skb->len < 24 + sizeof(*mmie))
1073 return RX_DROP_UNUSABLE;
1074
1075 mmie = (struct ieee80211_mmie_16 *)
1076 (skb->data + skb->len - sizeof(*mmie));
1077 if (mmie->element_id != WLAN_EID_MMIE ||
1078 mmie->length != sizeof(*mmie) - 2)
1079 return RX_DROP_UNUSABLE; /* Invalid MMIE */
1080
1081 bip_ipn_swap(ipn, mmie->sequence_number);
1082
1083 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1084 key->u.aes_cmac.replays++;
1085 return RX_DROP_UNUSABLE;
1086 }
1087
1088 if (!(status->flag & RX_FLAG_DECRYPTED)) {
1089 /* hardware didn't decrypt/verify MIC */
1090 bip_aad(skb, aad);
1091 ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1092 skb->data + 24, skb->len - 24, mic);
1093 if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1094 key->u.aes_cmac.icverrors++;
1095 return RX_DROP_UNUSABLE;
1096 }
1097 }
1098
1099 memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1100
1101 /* Remove MMIE */
1102 skb_trim(skb, skb->len - sizeof(*mmie));
1103
1104 return RX_CONTINUE;
1105 }
1106
1107 ieee80211_tx_result
ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data * tx)1108 ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data *tx)
1109 {
1110 struct sk_buff *skb;
1111 struct ieee80211_tx_info *info;
1112 struct ieee80211_key *key = tx->key;
1113 struct ieee80211_mmie_16 *mmie;
1114 struct ieee80211_hdr *hdr;
1115 u8 aad[GMAC_AAD_LEN];
1116 u64 pn64;
1117 u8 nonce[GMAC_NONCE_LEN];
1118
1119 if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
1120 return TX_DROP;
1121
1122 skb = skb_peek(&tx->skbs);
1123
1124 info = IEEE80211_SKB_CB(skb);
1125
1126 if (info->control.hw_key)
1127 return TX_CONTINUE;
1128
1129 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
1130 return TX_DROP;
1131
1132 mmie = skb_put(skb, sizeof(*mmie));
1133 mmie->element_id = WLAN_EID_MMIE;
1134 mmie->length = sizeof(*mmie) - 2;
1135 mmie->key_id = cpu_to_le16(key->conf.keyidx);
1136
1137 /* PN = PN + 1 */
1138 pn64 = atomic64_inc_return(&key->conf.tx_pn);
1139
1140 bip_ipn_set64(mmie->sequence_number, pn64);
1141
1142 bip_aad(skb, aad);
1143
1144 hdr = (struct ieee80211_hdr *)skb->data;
1145 memcpy(nonce, hdr->addr2, ETH_ALEN);
1146 bip_ipn_swap(nonce + ETH_ALEN, mmie->sequence_number);
1147
1148 /* MIC = AES-GMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */
1149 if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1150 skb->data + 24, skb->len - 24, mmie->mic) < 0)
1151 return TX_DROP;
1152
1153 return TX_CONTINUE;
1154 }
1155
1156 ieee80211_rx_result
ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data * rx)1157 ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data *rx)
1158 {
1159 struct sk_buff *skb = rx->skb;
1160 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1161 struct ieee80211_key *key = rx->key;
1162 struct ieee80211_mmie_16 *mmie;
1163 u8 aad[GMAC_AAD_LEN], *mic, ipn[6], nonce[GMAC_NONCE_LEN];
1164 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1165
1166 if (!ieee80211_is_mgmt(hdr->frame_control))
1167 return RX_CONTINUE;
1168
1169 /* management frames are already linear */
1170
1171 if (skb->len < 24 + sizeof(*mmie))
1172 return RX_DROP_UNUSABLE;
1173
1174 mmie = (struct ieee80211_mmie_16 *)
1175 (skb->data + skb->len - sizeof(*mmie));
1176 if (mmie->element_id != WLAN_EID_MMIE ||
1177 mmie->length != sizeof(*mmie) - 2)
1178 return RX_DROP_UNUSABLE; /* Invalid MMIE */
1179
1180 bip_ipn_swap(ipn, mmie->sequence_number);
1181
1182 if (memcmp(ipn, key->u.aes_gmac.rx_pn, 6) <= 0) {
1183 key->u.aes_gmac.replays++;
1184 return RX_DROP_UNUSABLE;
1185 }
1186
1187 if (!(status->flag & RX_FLAG_DECRYPTED)) {
1188 /* hardware didn't decrypt/verify MIC */
1189 bip_aad(skb, aad);
1190
1191 memcpy(nonce, hdr->addr2, ETH_ALEN);
1192 memcpy(nonce + ETH_ALEN, ipn, 6);
1193
1194 mic = kmalloc(GMAC_MIC_LEN, GFP_ATOMIC);
1195 if (!mic)
1196 return RX_DROP_UNUSABLE;
1197 if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1198 skb->data + 24, skb->len - 24,
1199 mic) < 0 ||
1200 crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1201 key->u.aes_gmac.icverrors++;
1202 kfree(mic);
1203 return RX_DROP_UNUSABLE;
1204 }
1205 kfree(mic);
1206 }
1207
1208 memcpy(key->u.aes_gmac.rx_pn, ipn, 6);
1209
1210 /* Remove MMIE */
1211 skb_trim(skb, skb->len - sizeof(*mmie));
1212
1213 return RX_CONTINUE;
1214 }
1215
1216 ieee80211_tx_result
ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data * tx)1217 ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx)
1218 {
1219 struct sk_buff *skb;
1220 struct ieee80211_tx_info *info = NULL;
1221 ieee80211_tx_result res;
1222
1223 skb_queue_walk(&tx->skbs, skb) {
1224 info = IEEE80211_SKB_CB(skb);
1225
1226 /* handle hw-only algorithm */
1227 if (!info->control.hw_key)
1228 return TX_DROP;
1229
1230 if (tx->key->flags & KEY_FLAG_CIPHER_SCHEME) {
1231 res = ieee80211_crypto_cs_encrypt(tx, skb);
1232 if (res != TX_CONTINUE)
1233 return res;
1234 }
1235 }
1236
1237 ieee80211_tx_set_protected(tx);
1238
1239 return TX_CONTINUE;
1240 }
1241
1242 ieee80211_rx_result
ieee80211_crypto_hw_decrypt(struct ieee80211_rx_data * rx)1243 ieee80211_crypto_hw_decrypt(struct ieee80211_rx_data *rx)
1244 {
1245 if (rx->sta && rx->sta->cipher_scheme)
1246 return ieee80211_crypto_cs_decrypt(rx);
1247
1248 return RX_DROP_UNUSABLE;
1249 }
1250