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 #include <crypto/algapi.h>
20
21 #include "ieee80211_i.h"
22 #include "michael.h"
23 #include "tkip.h"
24 #include "aes_ccm.h"
25 #include "aes_cmac.h"
26 #include "aes_gmac.h"
27 #include "aes_gcm.h"
28 #include "wpa.h"
29
30 ieee80211_tx_result
ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data * tx)31 ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
32 {
33 u8 *data, *key, *mic;
34 size_t data_len;
35 unsigned int hdrlen;
36 struct ieee80211_hdr *hdr;
37 struct sk_buff *skb = tx->skb;
38 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
39 int tail;
40
41 hdr = (struct ieee80211_hdr *)skb->data;
42 if (!tx->key || tx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
43 skb->len < 24 || !ieee80211_is_data_present(hdr->frame_control))
44 return TX_CONTINUE;
45
46 hdrlen = ieee80211_hdrlen(hdr->frame_control);
47 if (skb->len < hdrlen)
48 return TX_DROP;
49
50 data = skb->data + hdrlen;
51 data_len = skb->len - hdrlen;
52
53 if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) {
54 /* Need to use software crypto for the test */
55 info->control.hw_key = NULL;
56 }
57
58 if (info->control.hw_key &&
59 (info->flags & IEEE80211_TX_CTL_DONTFRAG ||
60 tx->local->ops->set_frag_threshold) &&
61 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) {
62 /* hwaccel - with no need for SW-generated MMIC */
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 key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY];
78 mic = skb_put(skb, MICHAEL_MIC_LEN);
79 michael_mic(key, hdr, data, data_len, mic);
80 if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE))
81 mic[0]++;
82
83 return TX_CONTINUE;
84 }
85
86
87 ieee80211_rx_result
ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data * rx)88 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
89 {
90 u8 *data, *key = NULL;
91 size_t data_len;
92 unsigned int hdrlen;
93 u8 mic[MICHAEL_MIC_LEN];
94 struct sk_buff *skb = rx->skb;
95 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
96 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
97
98 /*
99 * it makes no sense to check for MIC errors on anything other
100 * than data frames.
101 */
102 if (!ieee80211_is_data_present(hdr->frame_control))
103 return RX_CONTINUE;
104
105 /*
106 * No way to verify the MIC if the hardware stripped it or
107 * the IV with the key index. In this case we have solely rely
108 * on the driver to set RX_FLAG_MMIC_ERROR in the event of a
109 * MIC failure report.
110 */
111 if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) {
112 if (status->flag & RX_FLAG_MMIC_ERROR)
113 goto mic_fail_no_key;
114
115 if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key &&
116 rx->key->conf.cipher == WLAN_CIPHER_SUITE_TKIP)
117 goto update_iv;
118
119 return RX_CONTINUE;
120 }
121
122 /*
123 * Some hardware seems to generate Michael MIC failure reports; even
124 * though, the frame was not encrypted with TKIP and therefore has no
125 * MIC. Ignore the flag them to avoid triggering countermeasures.
126 */
127 if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
128 !(status->flag & RX_FLAG_DECRYPTED))
129 return RX_CONTINUE;
130
131 if (rx->sdata->vif.type == NL80211_IFTYPE_AP && rx->key->conf.keyidx) {
132 /*
133 * APs with pairwise keys should never receive Michael MIC
134 * errors for non-zero keyidx because these are reserved for
135 * group keys and only the AP is sending real multicast
136 * frames in the BSS.
137 */
138 return RX_DROP_UNUSABLE;
139 }
140
141 if (status->flag & RX_FLAG_MMIC_ERROR)
142 goto mic_fail;
143
144 hdrlen = ieee80211_hdrlen(hdr->frame_control);
145 if (skb->len < hdrlen + MICHAEL_MIC_LEN)
146 return RX_DROP_UNUSABLE;
147
148 if (skb_linearize(rx->skb))
149 return RX_DROP_UNUSABLE;
150 hdr = (void *)skb->data;
151
152 data = skb->data + hdrlen;
153 data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;
154 key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY];
155 michael_mic(key, hdr, data, data_len, mic);
156 if (crypto_memneq(mic, data + data_len, MICHAEL_MIC_LEN))
157 goto mic_fail;
158
159 /* remove Michael MIC from payload */
160 skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
161
162 update_iv:
163 /* update IV in key information to be able to detect replays */
164 rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip.iv32;
165 rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip.iv16;
166
167 return RX_CONTINUE;
168
169 mic_fail:
170 rx->key->u.tkip.mic_failures++;
171
172 mic_fail_no_key:
173 /*
174 * In some cases the key can be unset - e.g. a multicast packet, in
175 * a driver that supports HW encryption. Send up the key idx only if
176 * the key is set.
177 */
178 cfg80211_michael_mic_failure(rx->sdata->dev, hdr->addr2,
179 is_multicast_ether_addr(hdr->addr1) ?
180 NL80211_KEYTYPE_GROUP :
181 NL80211_KEYTYPE_PAIRWISE,
182 rx->key ? rx->key->conf.keyidx : -1,
183 NULL, GFP_ATOMIC);
184 return RX_DROP_UNUSABLE;
185 }
186
187
tkip_encrypt_skb(struct ieee80211_tx_data * tx,struct sk_buff * skb)188 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
189 {
190 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
191 struct ieee80211_key *key = tx->key;
192 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
193 unsigned int hdrlen;
194 int len, tail;
195 u8 *pos;
196
197 if (info->control.hw_key &&
198 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
199 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
200 /* hwaccel - with no need for software-generated IV */
201 return 0;
202 }
203
204 hdrlen = ieee80211_hdrlen(hdr->frame_control);
205 len = skb->len - hdrlen;
206
207 if (info->control.hw_key)
208 tail = 0;
209 else
210 tail = IEEE80211_TKIP_ICV_LEN;
211
212 if (WARN_ON(skb_tailroom(skb) < tail ||
213 skb_headroom(skb) < IEEE80211_TKIP_IV_LEN))
214 return -1;
215
216 pos = skb_push(skb, IEEE80211_TKIP_IV_LEN);
217 memmove(pos, pos + IEEE80211_TKIP_IV_LEN, hdrlen);
218 pos += hdrlen;
219
220 /* the HW only needs room for the IV, but not the actual IV */
221 if (info->control.hw_key &&
222 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
223 return 0;
224
225 /* Increase IV for the frame */
226 spin_lock(&key->u.tkip.txlock);
227 key->u.tkip.tx.iv16++;
228 if (key->u.tkip.tx.iv16 == 0)
229 key->u.tkip.tx.iv32++;
230 pos = ieee80211_tkip_add_iv(pos, key);
231 spin_unlock(&key->u.tkip.txlock);
232
233 /* hwaccel - with software IV */
234 if (info->control.hw_key)
235 return 0;
236
237 /* Add room for ICV */
238 skb_put(skb, IEEE80211_TKIP_ICV_LEN);
239
240 return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
241 key, skb, pos, len);
242 }
243
244
245 ieee80211_tx_result
ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data * tx)246 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
247 {
248 struct sk_buff *skb;
249
250 ieee80211_tx_set_protected(tx);
251
252 skb_queue_walk(&tx->skbs, skb) {
253 if (tkip_encrypt_skb(tx, skb) < 0)
254 return TX_DROP;
255 }
256
257 return TX_CONTINUE;
258 }
259
260
261 ieee80211_rx_result
ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data * rx)262 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
263 {
264 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
265 int hdrlen, res, hwaccel = 0;
266 struct ieee80211_key *key = rx->key;
267 struct sk_buff *skb = rx->skb;
268 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
269
270 hdrlen = ieee80211_hdrlen(hdr->frame_control);
271
272 if (!ieee80211_is_data(hdr->frame_control))
273 return RX_CONTINUE;
274
275 if (!rx->sta || skb->len - hdrlen < 12)
276 return RX_DROP_UNUSABLE;
277
278 /* it may be possible to optimize this a bit more */
279 if (skb_linearize(rx->skb))
280 return RX_DROP_UNUSABLE;
281 hdr = (void *)skb->data;
282
283 /*
284 * Let TKIP code verify IV, but skip decryption.
285 * In the case where hardware checks the IV as well,
286 * we don't even get here, see ieee80211_rx_h_decrypt()
287 */
288 if (status->flag & RX_FLAG_DECRYPTED)
289 hwaccel = 1;
290
291 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
292 key, skb->data + hdrlen,
293 skb->len - hdrlen, rx->sta->sta.addr,
294 hdr->addr1, hwaccel, rx->security_idx,
295 &rx->tkip.iv32,
296 &rx->tkip.iv16);
297 if (res != TKIP_DECRYPT_OK)
298 return RX_DROP_UNUSABLE;
299
300 /* Trim ICV */
301 if (!(status->flag & RX_FLAG_ICV_STRIPPED))
302 skb_trim(skb, skb->len - IEEE80211_TKIP_ICV_LEN);
303
304 /* Remove IV */
305 memmove(skb->data + IEEE80211_TKIP_IV_LEN, skb->data, hdrlen);
306 skb_pull(skb, IEEE80211_TKIP_IV_LEN);
307
308 return RX_CONTINUE;
309 }
310
311
ccmp_special_blocks(struct sk_buff * skb,u8 * pn,u8 * b_0,u8 * aad)312 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad)
313 {
314 __le16 mask_fc;
315 int a4_included, mgmt;
316 u8 qos_tid;
317 u16 len_a;
318 unsigned int hdrlen;
319 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
320
321 /*
322 * Mask FC: zero subtype b4 b5 b6 (if not mgmt)
323 * Retry, PwrMgt, MoreData; set Protected
324 */
325 mgmt = ieee80211_is_mgmt(hdr->frame_control);
326 mask_fc = hdr->frame_control;
327 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
328 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
329 if (!mgmt)
330 mask_fc &= ~cpu_to_le16(0x0070);
331 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
332
333 hdrlen = ieee80211_hdrlen(hdr->frame_control);
334 len_a = hdrlen - 2;
335 a4_included = ieee80211_has_a4(hdr->frame_control);
336
337 if (ieee80211_is_data_qos(hdr->frame_control))
338 qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
339 else
340 qos_tid = 0;
341
342 /* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC
343 * mode authentication are not allowed to collide, yet both are derived
344 * from this vector b_0. We only set L := 1 here to indicate that the
345 * data size can be represented in (L+1) bytes. The CCM layer will take
346 * care of storing the data length in the top (L+1) bytes and setting
347 * and clearing the other bits as is required to derive the two IVs.
348 */
349 b_0[0] = 0x1;
350
351 /* Nonce: Nonce Flags | A2 | PN
352 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)
353 */
354 b_0[1] = qos_tid | (mgmt << 4);
355 memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
356 memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN);
357
358 /* AAD (extra authenticate-only data) / masked 802.11 header
359 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
360 put_unaligned_be16(len_a, &aad[0]);
361 put_unaligned(mask_fc, (__le16 *)&aad[2]);
362 memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
363
364 /* Mask Seq#, leave Frag# */
365 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
366 aad[23] = 0;
367
368 if (a4_included) {
369 memcpy(&aad[24], hdr->addr4, ETH_ALEN);
370 aad[30] = qos_tid;
371 aad[31] = 0;
372 } else {
373 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
374 aad[24] = qos_tid;
375 }
376 }
377
378
ccmp_pn2hdr(u8 * hdr,u8 * pn,int key_id)379 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
380 {
381 hdr[0] = pn[5];
382 hdr[1] = pn[4];
383 hdr[2] = 0;
384 hdr[3] = 0x20 | (key_id << 6);
385 hdr[4] = pn[3];
386 hdr[5] = pn[2];
387 hdr[6] = pn[1];
388 hdr[7] = pn[0];
389 }
390
391
ccmp_hdr2pn(u8 * pn,u8 * hdr)392 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr)
393 {
394 pn[0] = hdr[7];
395 pn[1] = hdr[6];
396 pn[2] = hdr[5];
397 pn[3] = hdr[4];
398 pn[4] = hdr[1];
399 pn[5] = hdr[0];
400 }
401
402
ccmp_encrypt_skb(struct ieee80211_tx_data * tx,struct sk_buff * skb,unsigned int mic_len)403 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb,
404 unsigned int mic_len)
405 {
406 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
407 struct ieee80211_key *key = tx->key;
408 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
409 int hdrlen, len, tail;
410 u8 *pos;
411 u8 pn[6];
412 u64 pn64;
413 u8 aad[2 * AES_BLOCK_SIZE];
414 u8 b_0[AES_BLOCK_SIZE];
415
416 if (info->control.hw_key &&
417 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
418 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
419 !((info->control.hw_key->flags &
420 IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
421 ieee80211_is_mgmt(hdr->frame_control))) {
422 /*
423 * hwaccel has no need for preallocated room for CCMP
424 * header or MIC fields
425 */
426 return 0;
427 }
428
429 hdrlen = ieee80211_hdrlen(hdr->frame_control);
430 len = skb->len - hdrlen;
431
432 if (info->control.hw_key)
433 tail = 0;
434 else
435 tail = mic_len;
436
437 if (WARN_ON(skb_tailroom(skb) < tail ||
438 skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN))
439 return -1;
440
441 pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN);
442 memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen);
443
444 /* the HW only needs room for the IV, but not the actual IV */
445 if (info->control.hw_key &&
446 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
447 return 0;
448
449 hdr = (struct ieee80211_hdr *) pos;
450 pos += hdrlen;
451
452 pn64 = atomic64_inc_return(&key->conf.tx_pn);
453
454 pn[5] = pn64;
455 pn[4] = pn64 >> 8;
456 pn[3] = pn64 >> 16;
457 pn[2] = pn64 >> 24;
458 pn[1] = pn64 >> 32;
459 pn[0] = pn64 >> 40;
460
461 ccmp_pn2hdr(pos, pn, key->conf.keyidx);
462
463 /* hwaccel - with software CCMP header */
464 if (info->control.hw_key)
465 return 0;
466
467 pos += IEEE80211_CCMP_HDR_LEN;
468 ccmp_special_blocks(skb, pn, b_0, aad);
469 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,
470 skb_put(skb, mic_len), mic_len);
471
472 return 0;
473 }
474
475
476 ieee80211_tx_result
ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data * tx,unsigned int mic_len)477 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx,
478 unsigned int mic_len)
479 {
480 struct sk_buff *skb;
481
482 ieee80211_tx_set_protected(tx);
483
484 skb_queue_walk(&tx->skbs, skb) {
485 if (ccmp_encrypt_skb(tx, skb, mic_len) < 0)
486 return TX_DROP;
487 }
488
489 return TX_CONTINUE;
490 }
491
492
493 ieee80211_rx_result
ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data * rx,unsigned int mic_len)494 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
495 unsigned int mic_len)
496 {
497 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
498 int hdrlen;
499 struct ieee80211_key *key = rx->key;
500 struct sk_buff *skb = rx->skb;
501 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
502 u8 pn[IEEE80211_CCMP_PN_LEN];
503 int data_len;
504 int queue;
505
506 hdrlen = ieee80211_hdrlen(hdr->frame_control);
507
508 if (!ieee80211_is_data(hdr->frame_control) &&
509 !ieee80211_is_robust_mgmt_frame(skb))
510 return RX_CONTINUE;
511
512 if (status->flag & RX_FLAG_DECRYPTED) {
513 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_CCMP_HDR_LEN))
514 return RX_DROP_UNUSABLE;
515 if (status->flag & RX_FLAG_MIC_STRIPPED)
516 mic_len = 0;
517 } else {
518 if (skb_linearize(rx->skb))
519 return RX_DROP_UNUSABLE;
520 }
521
522 /* reload hdr - skb might have been reallocated */
523 hdr = (void *)rx->skb->data;
524
525 data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - mic_len;
526 if (!rx->sta || data_len < 0)
527 return RX_DROP_UNUSABLE;
528
529 if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
530 int res;
531
532 ccmp_hdr2pn(pn, skb->data + hdrlen);
533
534 queue = rx->security_idx;
535
536 res = memcmp(pn, key->u.ccmp.rx_pn[queue],
537 IEEE80211_CCMP_PN_LEN);
538 if (res < 0 ||
539 (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
540 key->u.ccmp.replays++;
541 return RX_DROP_UNUSABLE;
542 }
543
544 if (!(status->flag & RX_FLAG_DECRYPTED)) {
545 u8 aad[2 * AES_BLOCK_SIZE];
546 u8 b_0[AES_BLOCK_SIZE];
547 /* hardware didn't decrypt/verify MIC */
548 ccmp_special_blocks(skb, pn, b_0, aad);
549
550 if (ieee80211_aes_ccm_decrypt(
551 key->u.ccmp.tfm, b_0, aad,
552 skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN,
553 data_len,
554 skb->data + skb->len - mic_len, mic_len))
555 return RX_DROP_UNUSABLE;
556 }
557
558 memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN);
559 if (unlikely(ieee80211_is_frag(hdr)))
560 memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN);
561 }
562
563 /* Remove CCMP header and MIC */
564 if (pskb_trim(skb, skb->len - mic_len))
565 return RX_DROP_UNUSABLE;
566 memmove(skb->data + IEEE80211_CCMP_HDR_LEN, skb->data, hdrlen);
567 skb_pull(skb, IEEE80211_CCMP_HDR_LEN);
568
569 return RX_CONTINUE;
570 }
571
gcmp_special_blocks(struct sk_buff * skb,u8 * pn,u8 * j_0,u8 * aad)572 static void gcmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *j_0, u8 *aad)
573 {
574 __le16 mask_fc;
575 u8 qos_tid;
576 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
577
578 memcpy(j_0, hdr->addr2, ETH_ALEN);
579 memcpy(&j_0[ETH_ALEN], pn, IEEE80211_GCMP_PN_LEN);
580 j_0[13] = 0;
581 j_0[14] = 0;
582 j_0[AES_BLOCK_SIZE - 1] = 0x01;
583
584 /* AAD (extra authenticate-only data) / masked 802.11 header
585 * FC | A1 | A2 | A3 | SC | [A4] | [QC]
586 */
587 put_unaligned_be16(ieee80211_hdrlen(hdr->frame_control) - 2, &aad[0]);
588 /* Mask FC: zero subtype b4 b5 b6 (if not mgmt)
589 * Retry, PwrMgt, MoreData; set Protected
590 */
591 mask_fc = hdr->frame_control;
592 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
593 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
594 if (!ieee80211_is_mgmt(hdr->frame_control))
595 mask_fc &= ~cpu_to_le16(0x0070);
596 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
597
598 put_unaligned(mask_fc, (__le16 *)&aad[2]);
599 memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
600
601 /* Mask Seq#, leave Frag# */
602 aad[22] = *((u8 *)&hdr->seq_ctrl) & 0x0f;
603 aad[23] = 0;
604
605 if (ieee80211_is_data_qos(hdr->frame_control))
606 qos_tid = *ieee80211_get_qos_ctl(hdr) &
607 IEEE80211_QOS_CTL_TID_MASK;
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
gcmp_pn2hdr(u8 * hdr,const u8 * pn,int key_id)621 static 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
gcmp_hdr2pn(u8 * pn,const u8 * hdr)633 static 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
gcmp_encrypt_skb(struct ieee80211_tx_data * tx,struct sk_buff * skb)643 static 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[2 * AES_BLOCK_SIZE];
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 ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len,
710 skb_put(skb, IEEE80211_GCMP_MIC_LEN));
711
712 return 0;
713 }
714
715 ieee80211_tx_result
ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data * tx)716 ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data *tx)
717 {
718 struct sk_buff *skb;
719
720 ieee80211_tx_set_protected(tx);
721
722 skb_queue_walk(&tx->skbs, skb) {
723 if (gcmp_encrypt_skb(tx, skb) < 0)
724 return TX_DROP;
725 }
726
727 return TX_CONTINUE;
728 }
729
730 ieee80211_rx_result
ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data * rx)731 ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx)
732 {
733 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
734 int hdrlen;
735 struct ieee80211_key *key = rx->key;
736 struct sk_buff *skb = rx->skb;
737 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
738 u8 pn[IEEE80211_GCMP_PN_LEN];
739 int data_len, queue, mic_len = IEEE80211_GCMP_MIC_LEN;
740
741 hdrlen = ieee80211_hdrlen(hdr->frame_control);
742
743 if (!ieee80211_is_data(hdr->frame_control) &&
744 !ieee80211_is_robust_mgmt_frame(skb))
745 return RX_CONTINUE;
746
747 if (status->flag & RX_FLAG_DECRYPTED) {
748 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN))
749 return RX_DROP_UNUSABLE;
750 if (status->flag & RX_FLAG_MIC_STRIPPED)
751 mic_len = 0;
752 } else {
753 if (skb_linearize(rx->skb))
754 return RX_DROP_UNUSABLE;
755 }
756
757 /* reload hdr - skb might have been reallocated */
758 hdr = (void *)rx->skb->data;
759
760 data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - mic_len;
761 if (!rx->sta || data_len < 0)
762 return RX_DROP_UNUSABLE;
763
764 if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
765 int res;
766
767 gcmp_hdr2pn(pn, skb->data + hdrlen);
768
769 queue = rx->security_idx;
770
771 res = memcmp(pn, key->u.gcmp.rx_pn[queue],
772 IEEE80211_GCMP_PN_LEN);
773 if (res < 0 ||
774 (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
775 key->u.gcmp.replays++;
776 return RX_DROP_UNUSABLE;
777 }
778
779 if (!(status->flag & RX_FLAG_DECRYPTED)) {
780 u8 aad[2 * AES_BLOCK_SIZE];
781 u8 j_0[AES_BLOCK_SIZE];
782 /* hardware didn't decrypt/verify MIC */
783 gcmp_special_blocks(skb, pn, j_0, aad);
784
785 if (ieee80211_aes_gcm_decrypt(
786 key->u.gcmp.tfm, j_0, aad,
787 skb->data + hdrlen + IEEE80211_GCMP_HDR_LEN,
788 data_len,
789 skb->data + skb->len -
790 IEEE80211_GCMP_MIC_LEN))
791 return RX_DROP_UNUSABLE;
792 }
793
794 memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN);
795 if (unlikely(ieee80211_is_frag(hdr)))
796 memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN);
797 }
798
799 /* Remove GCMP header and MIC */
800 if (pskb_trim(skb, skb->len - mic_len))
801 return RX_DROP_UNUSABLE;
802 memmove(skb->data + IEEE80211_GCMP_HDR_LEN, skb->data, hdrlen);
803 skb_pull(skb, IEEE80211_GCMP_HDR_LEN);
804
805 return RX_CONTINUE;
806 }
807
808 static ieee80211_tx_result
ieee80211_crypto_cs_encrypt(struct ieee80211_tx_data * tx,struct sk_buff * skb)809 ieee80211_crypto_cs_encrypt(struct ieee80211_tx_data *tx,
810 struct sk_buff *skb)
811 {
812 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
813 struct ieee80211_key *key = tx->key;
814 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
815 int hdrlen;
816 u8 *pos, iv_len = key->conf.iv_len;
817
818 if (info->control.hw_key &&
819 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
820 /* hwaccel has no need for preallocated head room */
821 return TX_CONTINUE;
822 }
823
824 if (unlikely(skb_headroom(skb) < iv_len &&
825 pskb_expand_head(skb, iv_len, 0, GFP_ATOMIC)))
826 return TX_DROP;
827
828 hdrlen = ieee80211_hdrlen(hdr->frame_control);
829
830 pos = skb_push(skb, iv_len);
831 memmove(pos, pos + iv_len, hdrlen);
832
833 return TX_CONTINUE;
834 }
835
ieee80211_crypto_cs_pn_compare(u8 * pn1,u8 * pn2,int len)836 static inline int ieee80211_crypto_cs_pn_compare(u8 *pn1, u8 *pn2, int len)
837 {
838 int i;
839
840 /* pn is little endian */
841 for (i = len - 1; i >= 0; i--) {
842 if (pn1[i] < pn2[i])
843 return -1;
844 else if (pn1[i] > pn2[i])
845 return 1;
846 }
847
848 return 0;
849 }
850
851 static ieee80211_rx_result
ieee80211_crypto_cs_decrypt(struct ieee80211_rx_data * rx)852 ieee80211_crypto_cs_decrypt(struct ieee80211_rx_data *rx)
853 {
854 struct ieee80211_key *key = rx->key;
855 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
856 const struct ieee80211_cipher_scheme *cs = NULL;
857 int hdrlen = ieee80211_hdrlen(hdr->frame_control);
858 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
859 int data_len;
860 u8 *rx_pn;
861 u8 *skb_pn;
862 u8 qos_tid;
863
864 if (!rx->sta || !rx->sta->cipher_scheme ||
865 !(status->flag & RX_FLAG_DECRYPTED))
866 return RX_DROP_UNUSABLE;
867
868 if (!ieee80211_is_data(hdr->frame_control))
869 return RX_CONTINUE;
870
871 cs = rx->sta->cipher_scheme;
872
873 data_len = rx->skb->len - hdrlen - cs->hdr_len;
874
875 if (data_len < 0)
876 return RX_DROP_UNUSABLE;
877
878 if (ieee80211_is_data_qos(hdr->frame_control))
879 qos_tid = *ieee80211_get_qos_ctl(hdr) &
880 IEEE80211_QOS_CTL_TID_MASK;
881 else
882 qos_tid = 0;
883
884 if (skb_linearize(rx->skb))
885 return RX_DROP_UNUSABLE;
886
887 hdr = (struct ieee80211_hdr *)rx->skb->data;
888
889 rx_pn = key->u.gen.rx_pn[qos_tid];
890 skb_pn = rx->skb->data + hdrlen + cs->pn_off;
891
892 if (ieee80211_crypto_cs_pn_compare(skb_pn, rx_pn, cs->pn_len) <= 0)
893 return RX_DROP_UNUSABLE;
894
895 memcpy(rx_pn, skb_pn, cs->pn_len);
896
897 /* remove security header and MIC */
898 if (pskb_trim(rx->skb, rx->skb->len - cs->mic_len))
899 return RX_DROP_UNUSABLE;
900
901 memmove(rx->skb->data + cs->hdr_len, rx->skb->data, hdrlen);
902 skb_pull(rx->skb, cs->hdr_len);
903
904 return RX_CONTINUE;
905 }
906
bip_aad(struct sk_buff * skb,u8 * aad)907 static void bip_aad(struct sk_buff *skb, u8 *aad)
908 {
909 __le16 mask_fc;
910 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
911
912 /* BIP AAD: FC(masked) || A1 || A2 || A3 */
913
914 /* FC type/subtype */
915 /* Mask FC Retry, PwrMgt, MoreData flags to zero */
916 mask_fc = hdr->frame_control;
917 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM |
918 IEEE80211_FCTL_MOREDATA);
919 put_unaligned(mask_fc, (__le16 *) &aad[0]);
920 /* A1 || A2 || A3 */
921 memcpy(aad + 2, &hdr->addr1, 3 * ETH_ALEN);
922 }
923
924
bip_ipn_set64(u8 * d,u64 pn)925 static inline void bip_ipn_set64(u8 *d, u64 pn)
926 {
927 *d++ = pn;
928 *d++ = pn >> 8;
929 *d++ = pn >> 16;
930 *d++ = pn >> 24;
931 *d++ = pn >> 32;
932 *d = pn >> 40;
933 }
934
bip_ipn_swap(u8 * d,const u8 * s)935 static inline void bip_ipn_swap(u8 *d, const u8 *s)
936 {
937 *d++ = s[5];
938 *d++ = s[4];
939 *d++ = s[3];
940 *d++ = s[2];
941 *d++ = s[1];
942 *d = s[0];
943 }
944
945
946 ieee80211_tx_result
ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data * tx)947 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
948 {
949 struct sk_buff *skb;
950 struct ieee80211_tx_info *info;
951 struct ieee80211_key *key = tx->key;
952 struct ieee80211_mmie *mmie;
953 u8 aad[20];
954 u64 pn64;
955
956 if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
957 return TX_DROP;
958
959 skb = skb_peek(&tx->skbs);
960
961 info = IEEE80211_SKB_CB(skb);
962
963 if (info->control.hw_key)
964 return TX_CONTINUE;
965
966 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
967 return TX_DROP;
968
969 mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie));
970 mmie->element_id = WLAN_EID_MMIE;
971 mmie->length = sizeof(*mmie) - 2;
972 mmie->key_id = cpu_to_le16(key->conf.keyidx);
973
974 /* PN = PN + 1 */
975 pn64 = atomic64_inc_return(&key->conf.tx_pn);
976
977 bip_ipn_set64(mmie->sequence_number, pn64);
978
979 bip_aad(skb, aad);
980
981 /*
982 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
983 */
984 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
985 skb->data + 24, skb->len - 24, mmie->mic);
986
987 return TX_CONTINUE;
988 }
989
990 ieee80211_tx_result
ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data * tx)991 ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx)
992 {
993 struct sk_buff *skb;
994 struct ieee80211_tx_info *info;
995 struct ieee80211_key *key = tx->key;
996 struct ieee80211_mmie_16 *mmie;
997 u8 aad[20];
998 u64 pn64;
999
1000 if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
1001 return TX_DROP;
1002
1003 skb = skb_peek(&tx->skbs);
1004
1005 info = IEEE80211_SKB_CB(skb);
1006
1007 if (info->control.hw_key)
1008 return TX_CONTINUE;
1009
1010 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
1011 return TX_DROP;
1012
1013 mmie = (struct ieee80211_mmie_16 *)skb_put(skb, sizeof(*mmie));
1014 mmie->element_id = WLAN_EID_MMIE;
1015 mmie->length = sizeof(*mmie) - 2;
1016 mmie->key_id = cpu_to_le16(key->conf.keyidx);
1017
1018 /* PN = PN + 1 */
1019 pn64 = atomic64_inc_return(&key->conf.tx_pn);
1020
1021 bip_ipn_set64(mmie->sequence_number, pn64);
1022
1023 bip_aad(skb, aad);
1024
1025 /* MIC = AES-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128)
1026 */
1027 ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1028 skb->data + 24, skb->len - 24, mmie->mic);
1029
1030 return TX_CONTINUE;
1031 }
1032
1033 ieee80211_rx_result
ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data * rx)1034 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
1035 {
1036 struct sk_buff *skb = rx->skb;
1037 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1038 struct ieee80211_key *key = rx->key;
1039 struct ieee80211_mmie *mmie;
1040 u8 aad[20], mic[8], ipn[6];
1041 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1042
1043 if (!ieee80211_is_mgmt(hdr->frame_control))
1044 return RX_CONTINUE;
1045
1046 /* management frames are already linear */
1047
1048 if (skb->len < 24 + sizeof(*mmie))
1049 return RX_DROP_UNUSABLE;
1050
1051 mmie = (struct ieee80211_mmie *)
1052 (skb->data + skb->len - sizeof(*mmie));
1053 if (mmie->element_id != WLAN_EID_MMIE ||
1054 mmie->length != sizeof(*mmie) - 2)
1055 return RX_DROP_UNUSABLE; /* Invalid MMIE */
1056
1057 bip_ipn_swap(ipn, mmie->sequence_number);
1058
1059 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1060 key->u.aes_cmac.replays++;
1061 return RX_DROP_UNUSABLE;
1062 }
1063
1064 if (!(status->flag & RX_FLAG_DECRYPTED)) {
1065 /* hardware didn't decrypt/verify MIC */
1066 bip_aad(skb, aad);
1067 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
1068 skb->data + 24, skb->len - 24, mic);
1069 if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1070 key->u.aes_cmac.icverrors++;
1071 return RX_DROP_UNUSABLE;
1072 }
1073 }
1074
1075 memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1076
1077 /* Remove MMIE */
1078 skb_trim(skb, skb->len - sizeof(*mmie));
1079
1080 return RX_CONTINUE;
1081 }
1082
1083 ieee80211_rx_result
ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data * rx)1084 ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx)
1085 {
1086 struct sk_buff *skb = rx->skb;
1087 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1088 struct ieee80211_key *key = rx->key;
1089 struct ieee80211_mmie_16 *mmie;
1090 u8 aad[20], mic[16], ipn[6];
1091 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1092
1093 if (!ieee80211_is_mgmt(hdr->frame_control))
1094 return RX_CONTINUE;
1095
1096 /* management frames are already linear */
1097
1098 if (skb->len < 24 + sizeof(*mmie))
1099 return RX_DROP_UNUSABLE;
1100
1101 mmie = (struct ieee80211_mmie_16 *)
1102 (skb->data + skb->len - sizeof(*mmie));
1103 if (mmie->element_id != WLAN_EID_MMIE ||
1104 mmie->length != sizeof(*mmie) - 2)
1105 return RX_DROP_UNUSABLE; /* Invalid MMIE */
1106
1107 bip_ipn_swap(ipn, mmie->sequence_number);
1108
1109 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1110 key->u.aes_cmac.replays++;
1111 return RX_DROP_UNUSABLE;
1112 }
1113
1114 if (!(status->flag & RX_FLAG_DECRYPTED)) {
1115 /* hardware didn't decrypt/verify MIC */
1116 bip_aad(skb, aad);
1117 ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1118 skb->data + 24, skb->len - 24, mic);
1119 if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1120 key->u.aes_cmac.icverrors++;
1121 return RX_DROP_UNUSABLE;
1122 }
1123 }
1124
1125 memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1126
1127 /* Remove MMIE */
1128 skb_trim(skb, skb->len - sizeof(*mmie));
1129
1130 return RX_CONTINUE;
1131 }
1132
1133 ieee80211_tx_result
ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data * tx)1134 ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data *tx)
1135 {
1136 struct sk_buff *skb;
1137 struct ieee80211_tx_info *info;
1138 struct ieee80211_key *key = tx->key;
1139 struct ieee80211_mmie_16 *mmie;
1140 struct ieee80211_hdr *hdr;
1141 u8 aad[20];
1142 u64 pn64;
1143 u8 nonce[12];
1144
1145 if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
1146 return TX_DROP;
1147
1148 skb = skb_peek(&tx->skbs);
1149
1150 info = IEEE80211_SKB_CB(skb);
1151
1152 if (info->control.hw_key)
1153 return TX_CONTINUE;
1154
1155 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
1156 return TX_DROP;
1157
1158 mmie = (struct ieee80211_mmie_16 *)skb_put(skb, sizeof(*mmie));
1159 mmie->element_id = WLAN_EID_MMIE;
1160 mmie->length = sizeof(*mmie) - 2;
1161 mmie->key_id = cpu_to_le16(key->conf.keyidx);
1162
1163 /* PN = PN + 1 */
1164 pn64 = atomic64_inc_return(&key->conf.tx_pn);
1165
1166 bip_ipn_set64(mmie->sequence_number, pn64);
1167
1168 bip_aad(skb, aad);
1169
1170 hdr = (struct ieee80211_hdr *)skb->data;
1171 memcpy(nonce, hdr->addr2, ETH_ALEN);
1172 bip_ipn_swap(nonce + ETH_ALEN, mmie->sequence_number);
1173
1174 /* MIC = AES-GMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */
1175 if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1176 skb->data + 24, skb->len - 24, mmie->mic) < 0)
1177 return TX_DROP;
1178
1179 return TX_CONTINUE;
1180 }
1181
1182 ieee80211_rx_result
ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data * rx)1183 ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data *rx)
1184 {
1185 struct sk_buff *skb = rx->skb;
1186 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1187 struct ieee80211_key *key = rx->key;
1188 struct ieee80211_mmie_16 *mmie;
1189 u8 aad[20], mic[16], ipn[6], nonce[12];
1190 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1191
1192 if (!ieee80211_is_mgmt(hdr->frame_control))
1193 return RX_CONTINUE;
1194
1195 /* management frames are already linear */
1196
1197 if (skb->len < 24 + sizeof(*mmie))
1198 return RX_DROP_UNUSABLE;
1199
1200 mmie = (struct ieee80211_mmie_16 *)
1201 (skb->data + skb->len - sizeof(*mmie));
1202 if (mmie->element_id != WLAN_EID_MMIE ||
1203 mmie->length != sizeof(*mmie) - 2)
1204 return RX_DROP_UNUSABLE; /* Invalid MMIE */
1205
1206 bip_ipn_swap(ipn, mmie->sequence_number);
1207
1208 if (memcmp(ipn, key->u.aes_gmac.rx_pn, 6) <= 0) {
1209 key->u.aes_gmac.replays++;
1210 return RX_DROP_UNUSABLE;
1211 }
1212
1213 if (!(status->flag & RX_FLAG_DECRYPTED)) {
1214 /* hardware didn't decrypt/verify MIC */
1215 bip_aad(skb, aad);
1216
1217 memcpy(nonce, hdr->addr2, ETH_ALEN);
1218 memcpy(nonce + ETH_ALEN, ipn, 6);
1219
1220 if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1221 skb->data + 24, skb->len - 24,
1222 mic) < 0 ||
1223 crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1224 key->u.aes_gmac.icverrors++;
1225 return RX_DROP_UNUSABLE;
1226 }
1227 }
1228
1229 memcpy(key->u.aes_gmac.rx_pn, ipn, 6);
1230
1231 /* Remove MMIE */
1232 skb_trim(skb, skb->len - sizeof(*mmie));
1233
1234 return RX_CONTINUE;
1235 }
1236
1237 ieee80211_tx_result
ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data * tx)1238 ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx)
1239 {
1240 struct sk_buff *skb;
1241 struct ieee80211_tx_info *info = NULL;
1242 ieee80211_tx_result res;
1243
1244 skb_queue_walk(&tx->skbs, skb) {
1245 info = IEEE80211_SKB_CB(skb);
1246
1247 /* handle hw-only algorithm */
1248 if (!info->control.hw_key)
1249 return TX_DROP;
1250
1251 if (tx->key->flags & KEY_FLAG_CIPHER_SCHEME) {
1252 res = ieee80211_crypto_cs_encrypt(tx, skb);
1253 if (res != TX_CONTINUE)
1254 return res;
1255 }
1256 }
1257
1258 ieee80211_tx_set_protected(tx);
1259
1260 return TX_CONTINUE;
1261 }
1262
1263 ieee80211_rx_result
ieee80211_crypto_hw_decrypt(struct ieee80211_rx_data * rx)1264 ieee80211_crypto_hw_decrypt(struct ieee80211_rx_data *rx)
1265 {
1266 if (rx->sta && rx->sta->cipher_scheme)
1267 return ieee80211_crypto_cs_decrypt(rx);
1268
1269 return RX_DROP_UNUSABLE;
1270 }
1271