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[mirror_ubuntu-jammy-kernel.git] / net / mac80211 / wpa.c
1 /*
2 * Copyright 2002-2004, Instant802 Networks, Inc.
3 * Copyright 2008, Jouni Malinen <j@w1.fi>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9
10 #include <linux/netdevice.h>
11 #include <linux/types.h>
12 #include <linux/skbuff.h>
13 #include <linux/compiler.h>
14 #include <linux/ieee80211.h>
15 #include <linux/gfp.h>
16 #include <asm/unaligned.h>
17 #include <net/mac80211.h>
18 #include <crypto/aes.h>
19
20 #include "ieee80211_i.h"
21 #include "michael.h"
22 #include "tkip.h"
23 #include "aes_ccm.h"
24 #include "aes_cmac.h"
25 #include "wpa.h"
26
27 ieee80211_tx_result
28 ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
29 {
30 u8 *data, *key, *mic;
31 size_t data_len;
32 unsigned int hdrlen;
33 struct ieee80211_hdr *hdr;
34 struct sk_buff *skb = tx->skb;
35 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
36 int tail;
37
38 hdr = (struct ieee80211_hdr *)skb->data;
39 if (!tx->key || tx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
40 skb->len < 24 || !ieee80211_is_data_present(hdr->frame_control))
41 return TX_CONTINUE;
42
43 hdrlen = ieee80211_hdrlen(hdr->frame_control);
44 if (skb->len < hdrlen)
45 return TX_DROP;
46
47 data = skb->data + hdrlen;
48 data_len = skb->len - hdrlen;
49
50 if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) {
51 /* Need to use software crypto for the test */
52 info->control.hw_key = NULL;
53 }
54
55 if (info->control.hw_key &&
56 (info->flags & IEEE80211_TX_CTL_DONTFRAG ||
57 tx->local->ops->set_frag_threshold) &&
58 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) {
59 /* hwaccel - with no need for SW-generated MMIC */
60 return TX_CONTINUE;
61 }
62
63 tail = MICHAEL_MIC_LEN;
64 if (!info->control.hw_key)
65 tail += IEEE80211_TKIP_ICV_LEN;
66
67 if (WARN_ON(skb_tailroom(skb) < tail ||
68 skb_headroom(skb) < IEEE80211_TKIP_IV_LEN))
69 return TX_DROP;
70
71 key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY];
72 mic = skb_put(skb, MICHAEL_MIC_LEN);
73 michael_mic(key, hdr, data, data_len, mic);
74 if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE))
75 mic[0]++;
76
77 return TX_CONTINUE;
78 }
79
80
81 ieee80211_rx_result
82 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
83 {
84 u8 *data, *key = NULL;
85 size_t data_len;
86 unsigned int hdrlen;
87 u8 mic[MICHAEL_MIC_LEN];
88 struct sk_buff *skb = rx->skb;
89 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
90 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
91
92 /*
93 * it makes no sense to check for MIC errors on anything other
94 * than data frames.
95 */
96 if (!ieee80211_is_data_present(hdr->frame_control))
97 return RX_CONTINUE;
98
99 /*
100 * No way to verify the MIC if the hardware stripped it or
101 * the IV with the key index. In this case we have solely rely
102 * on the driver to set RX_FLAG_MMIC_ERROR in the event of a
103 * MIC failure report.
104 */
105 if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) {
106 if (status->flag & RX_FLAG_MMIC_ERROR)
107 goto mic_fail_no_key;
108
109 if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key &&
110 rx->key->conf.cipher == WLAN_CIPHER_SUITE_TKIP)
111 goto update_iv;
112
113 return RX_CONTINUE;
114 }
115
116 /*
117 * Some hardware seems to generate Michael MIC failure reports; even
118 * though, the frame was not encrypted with TKIP and therefore has no
119 * MIC. Ignore the flag them to avoid triggering countermeasures.
120 */
121 if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
122 !(status->flag & RX_FLAG_DECRYPTED))
123 return RX_CONTINUE;
124
125 if (rx->sdata->vif.type == NL80211_IFTYPE_AP && rx->key->conf.keyidx) {
126 /*
127 * APs with pairwise keys should never receive Michael MIC
128 * errors for non-zero keyidx because these are reserved for
129 * group keys and only the AP is sending real multicast
130 * frames in the BSS.
131 */
132 return RX_DROP_UNUSABLE;
133 }
134
135 if (status->flag & RX_FLAG_MMIC_ERROR)
136 goto mic_fail;
137
138 hdrlen = ieee80211_hdrlen(hdr->frame_control);
139 if (skb->len < hdrlen + MICHAEL_MIC_LEN)
140 return RX_DROP_UNUSABLE;
141
142 if (skb_linearize(rx->skb))
143 return RX_DROP_UNUSABLE;
144 hdr = (void *)skb->data;
145
146 data = skb->data + hdrlen;
147 data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;
148 key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY];
149 michael_mic(key, hdr, data, data_len, mic);
150 if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0)
151 goto mic_fail;
152
153 /* remove Michael MIC from payload */
154 skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
155
156 update_iv:
157 /* update IV in key information to be able to detect replays */
158 rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip_iv32;
159 rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip_iv16;
160
161 return RX_CONTINUE;
162
163 mic_fail:
164 rx->key->u.tkip.mic_failures++;
165
166 mic_fail_no_key:
167 /*
168 * In some cases the key can be unset - e.g. a multicast packet, in
169 * a driver that supports HW encryption. Send up the key idx only if
170 * the key is set.
171 */
172 mac80211_ev_michael_mic_failure(rx->sdata,
173 rx->key ? rx->key->conf.keyidx : -1,
174 (void *) skb->data, NULL, GFP_ATOMIC);
175 return RX_DROP_UNUSABLE;
176 }
177
178
179 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
180 {
181 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
182 struct ieee80211_key *key = tx->key;
183 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
184 unsigned int hdrlen;
185 int len, tail;
186 u8 *pos;
187
188 if (info->control.hw_key &&
189 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
190 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
191 /* hwaccel - with no need for software-generated IV */
192 return 0;
193 }
194
195 hdrlen = ieee80211_hdrlen(hdr->frame_control);
196 len = skb->len - hdrlen;
197
198 if (info->control.hw_key)
199 tail = 0;
200 else
201 tail = IEEE80211_TKIP_ICV_LEN;
202
203 if (WARN_ON(skb_tailroom(skb) < tail ||
204 skb_headroom(skb) < IEEE80211_TKIP_IV_LEN))
205 return -1;
206
207 pos = skb_push(skb, IEEE80211_TKIP_IV_LEN);
208 memmove(pos, pos + IEEE80211_TKIP_IV_LEN, hdrlen);
209 skb_set_network_header(skb, skb_network_offset(skb) +
210 IEEE80211_TKIP_IV_LEN);
211 pos += hdrlen;
212
213 /* the HW only needs room for the IV, but not the actual IV */
214 if (info->control.hw_key &&
215 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
216 return 0;
217
218 /* Increase IV for the frame */
219 spin_lock(&key->u.tkip.txlock);
220 key->u.tkip.tx.iv16++;
221 if (key->u.tkip.tx.iv16 == 0)
222 key->u.tkip.tx.iv32++;
223 pos = ieee80211_tkip_add_iv(pos, key);
224 spin_unlock(&key->u.tkip.txlock);
225
226 /* hwaccel - with software IV */
227 if (info->control.hw_key)
228 return 0;
229
230 /* Add room for ICV */
231 skb_put(skb, IEEE80211_TKIP_ICV_LEN);
232
233 return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
234 key, skb, pos, len);
235 }
236
237
238 ieee80211_tx_result
239 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
240 {
241 struct sk_buff *skb;
242
243 ieee80211_tx_set_protected(tx);
244
245 skb_queue_walk(&tx->skbs, skb) {
246 if (tkip_encrypt_skb(tx, skb) < 0)
247 return TX_DROP;
248 }
249
250 return TX_CONTINUE;
251 }
252
253
254 ieee80211_rx_result
255 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
256 {
257 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
258 int hdrlen, res, hwaccel = 0;
259 struct ieee80211_key *key = rx->key;
260 struct sk_buff *skb = rx->skb;
261 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
262
263 hdrlen = ieee80211_hdrlen(hdr->frame_control);
264
265 if (!ieee80211_is_data(hdr->frame_control))
266 return RX_CONTINUE;
267
268 if (!rx->sta || skb->len - hdrlen < 12)
269 return RX_DROP_UNUSABLE;
270
271 /* it may be possible to optimize this a bit more */
272 if (skb_linearize(rx->skb))
273 return RX_DROP_UNUSABLE;
274 hdr = (void *)skb->data;
275
276 /*
277 * Let TKIP code verify IV, but skip decryption.
278 * In the case where hardware checks the IV as well,
279 * we don't even get here, see ieee80211_rx_h_decrypt()
280 */
281 if (status->flag & RX_FLAG_DECRYPTED)
282 hwaccel = 1;
283
284 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
285 key, skb->data + hdrlen,
286 skb->len - hdrlen, rx->sta->sta.addr,
287 hdr->addr1, hwaccel, rx->security_idx,
288 &rx->tkip_iv32,
289 &rx->tkip_iv16);
290 if (res != TKIP_DECRYPT_OK)
291 return RX_DROP_UNUSABLE;
292
293 /* Trim ICV */
294 skb_trim(skb, skb->len - IEEE80211_TKIP_ICV_LEN);
295
296 /* Remove IV */
297 memmove(skb->data + IEEE80211_TKIP_IV_LEN, skb->data, hdrlen);
298 skb_pull(skb, IEEE80211_TKIP_IV_LEN);
299
300 return RX_CONTINUE;
301 }
302
303
304 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad)
305 {
306 __le16 mask_fc;
307 int a4_included, mgmt;
308 u8 qos_tid;
309 u16 len_a;
310 unsigned int hdrlen;
311 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
312
313 /*
314 * Mask FC: zero subtype b4 b5 b6 (if not mgmt)
315 * Retry, PwrMgt, MoreData; set Protected
316 */
317 mgmt = ieee80211_is_mgmt(hdr->frame_control);
318 mask_fc = hdr->frame_control;
319 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
320 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
321 if (!mgmt)
322 mask_fc &= ~cpu_to_le16(0x0070);
323 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
324
325 hdrlen = ieee80211_hdrlen(hdr->frame_control);
326 len_a = hdrlen - 2;
327 a4_included = ieee80211_has_a4(hdr->frame_control);
328
329 if (ieee80211_is_data_qos(hdr->frame_control))
330 qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
331 else
332 qos_tid = 0;
333
334 /* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC
335 * mode authentication are not allowed to collide, yet both are derived
336 * from this vector b_0. We only set L := 1 here to indicate that the
337 * data size can be represented in (L+1) bytes. The CCM layer will take
338 * care of storing the data length in the top (L+1) bytes and setting
339 * and clearing the other bits as is required to derive the two IVs.
340 */
341 b_0[0] = 0x1;
342
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, IEEE80211_CCMP_PN_LEN);
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
370
371 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
372 {
373 hdr[0] = pn[5];
374 hdr[1] = pn[4];
375 hdr[2] = 0;
376 hdr[3] = 0x20 | (key_id << 6);
377 hdr[4] = pn[3];
378 hdr[5] = pn[2];
379 hdr[6] = pn[1];
380 hdr[7] = pn[0];
381 }
382
383
384 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr)
385 {
386 pn[0] = hdr[7];
387 pn[1] = hdr[6];
388 pn[2] = hdr[5];
389 pn[3] = hdr[4];
390 pn[4] = hdr[1];
391 pn[5] = hdr[0];
392 }
393
394
395 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
396 {
397 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
398 struct ieee80211_key *key = tx->key;
399 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
400 int hdrlen, len, tail;
401 u8 *pos;
402 u8 pn[6];
403 u64 pn64;
404 u8 aad[2 * AES_BLOCK_SIZE];
405 u8 b_0[AES_BLOCK_SIZE];
406
407 if (info->control.hw_key &&
408 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
409 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
410 /*
411 * hwaccel has no need for preallocated room for CCMP
412 * header or MIC fields
413 */
414 return 0;
415 }
416
417 hdrlen = ieee80211_hdrlen(hdr->frame_control);
418 len = skb->len - hdrlen;
419
420 if (info->control.hw_key)
421 tail = 0;
422 else
423 tail = IEEE80211_CCMP_MIC_LEN;
424
425 if (WARN_ON(skb_tailroom(skb) < tail ||
426 skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN))
427 return -1;
428
429 pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN);
430 memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen);
431 skb_set_network_header(skb, skb_network_offset(skb) +
432 IEEE80211_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 += IEEE80211_CCMP_HDR_LEN;
458 ccmp_special_blocks(skb, pn, b_0, aad);
459 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,
460 skb_put(skb, IEEE80211_CCMP_MIC_LEN));
461
462 return 0;
463 }
464
465
466 ieee80211_tx_result
467 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx)
468 {
469 struct sk_buff *skb;
470
471 ieee80211_tx_set_protected(tx);
472
473 skb_queue_walk(&tx->skbs, skb) {
474 if (ccmp_encrypt_skb(tx, skb) < 0)
475 return TX_DROP;
476 }
477
478 return TX_CONTINUE;
479 }
480
481
482 ieee80211_rx_result
483 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx)
484 {
485 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
486 int hdrlen;
487 struct ieee80211_key *key = rx->key;
488 struct sk_buff *skb = rx->skb;
489 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
490 u8 pn[IEEE80211_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(skb))
498 return RX_CONTINUE;
499
500 data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN -
501 IEEE80211_CCMP_MIC_LEN;
502 if (!rx->sta || data_len < 0)
503 return RX_DROP_UNUSABLE;
504
505 if (status->flag & RX_FLAG_DECRYPTED) {
506 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_CCMP_HDR_LEN))
507 return RX_DROP_UNUSABLE;
508 } else {
509 if (skb_linearize(rx->skb))
510 return RX_DROP_UNUSABLE;
511 }
512
513 ccmp_hdr2pn(pn, skb->data + hdrlen);
514
515 queue = rx->security_idx;
516
517 if (memcmp(pn, key->u.ccmp.rx_pn[queue], IEEE80211_CCMP_PN_LEN) <= 0) {
518 key->u.ccmp.replays++;
519 return RX_DROP_UNUSABLE;
520 }
521
522 if (!(status->flag & RX_FLAG_DECRYPTED)) {
523 u8 aad[2 * AES_BLOCK_SIZE];
524 u8 b_0[AES_BLOCK_SIZE];
525 /* hardware didn't decrypt/verify MIC */
526 ccmp_special_blocks(skb, pn, b_0, aad);
527
528 if (ieee80211_aes_ccm_decrypt(
529 key->u.ccmp.tfm, b_0, aad,
530 skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN,
531 data_len,
532 skb->data + skb->len - IEEE80211_CCMP_MIC_LEN))
533 return RX_DROP_UNUSABLE;
534 }
535
536 memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN);
537
538 /* Remove CCMP header and MIC */
539 if (pskb_trim(skb, skb->len - IEEE80211_CCMP_MIC_LEN))
540 return RX_DROP_UNUSABLE;
541 memmove(skb->data + IEEE80211_CCMP_HDR_LEN, skb->data, hdrlen);
542 skb_pull(skb, IEEE80211_CCMP_HDR_LEN);
543
544 return RX_CONTINUE;
545 }
546
547 static ieee80211_tx_result
548 ieee80211_crypto_cs_encrypt(struct ieee80211_tx_data *tx,
549 struct sk_buff *skb)
550 {
551 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
552 struct ieee80211_key *key = tx->key;
553 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
554 const struct ieee80211_cipher_scheme *cs = key->sta->cipher_scheme;
555 int hdrlen;
556 u8 *pos;
557
558 if (info->control.hw_key &&
559 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
560 /* hwaccel has no need for preallocated head room */
561 return TX_CONTINUE;
562 }
563
564 if (unlikely(skb_headroom(skb) < cs->hdr_len &&
565 pskb_expand_head(skb, cs->hdr_len, 0, GFP_ATOMIC)))
566 return TX_DROP;
567
568 hdrlen = ieee80211_hdrlen(hdr->frame_control);
569
570 pos = skb_push(skb, cs->hdr_len);
571 memmove(pos, pos + cs->hdr_len, hdrlen);
572 skb_set_network_header(skb, skb_network_offset(skb) + cs->hdr_len);
573
574 return TX_CONTINUE;
575 }
576
577 static inline int ieee80211_crypto_cs_pn_compare(u8 *pn1, u8 *pn2, int len)
578 {
579 int i;
580
581 /* pn is little endian */
582 for (i = len - 1; i >= 0; i--) {
583 if (pn1[i] < pn2[i])
584 return -1;
585 else if (pn1[i] > pn2[i])
586 return 1;
587 }
588
589 return 0;
590 }
591
592 static ieee80211_rx_result
593 ieee80211_crypto_cs_decrypt(struct ieee80211_rx_data *rx)
594 {
595 struct ieee80211_key *key = rx->key;
596 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
597 const struct ieee80211_cipher_scheme *cs = NULL;
598 int hdrlen = ieee80211_hdrlen(hdr->frame_control);
599 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
600 int data_len;
601 u8 *rx_pn;
602 u8 *skb_pn;
603 u8 qos_tid;
604
605 if (!rx->sta || !rx->sta->cipher_scheme ||
606 !(status->flag & RX_FLAG_DECRYPTED))
607 return RX_DROP_UNUSABLE;
608
609 if (!ieee80211_is_data(hdr->frame_control))
610 return RX_CONTINUE;
611
612 cs = rx->sta->cipher_scheme;
613
614 data_len = rx->skb->len - hdrlen - cs->hdr_len;
615
616 if (data_len < 0)
617 return RX_DROP_UNUSABLE;
618
619 if (ieee80211_is_data_qos(hdr->frame_control))
620 qos_tid = *ieee80211_get_qos_ctl(hdr) &
621 IEEE80211_QOS_CTL_TID_MASK;
622 else
623 qos_tid = 0;
624
625 if (skb_linearize(rx->skb))
626 return RX_DROP_UNUSABLE;
627
628 hdr = (struct ieee80211_hdr *)rx->skb->data;
629
630 rx_pn = key->u.gen.rx_pn[qos_tid];
631 skb_pn = rx->skb->data + hdrlen + cs->pn_off;
632
633 if (ieee80211_crypto_cs_pn_compare(skb_pn, rx_pn, cs->pn_len) <= 0)
634 return RX_DROP_UNUSABLE;
635
636 memcpy(rx_pn, skb_pn, cs->pn_len);
637
638 /* remove security header and MIC */
639 if (pskb_trim(rx->skb, rx->skb->len - cs->mic_len))
640 return RX_DROP_UNUSABLE;
641
642 memmove(rx->skb->data + cs->hdr_len, rx->skb->data, hdrlen);
643 skb_pull(rx->skb, cs->hdr_len);
644
645 return RX_CONTINUE;
646 }
647
648 static void bip_aad(struct sk_buff *skb, u8 *aad)
649 {
650 __le16 mask_fc;
651 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
652
653 /* BIP AAD: FC(masked) || A1 || A2 || A3 */
654
655 /* FC type/subtype */
656 /* Mask FC Retry, PwrMgt, MoreData flags to zero */
657 mask_fc = hdr->frame_control;
658 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM |
659 IEEE80211_FCTL_MOREDATA);
660 put_unaligned(mask_fc, (__le16 *) &aad[0]);
661 /* A1 || A2 || A3 */
662 memcpy(aad + 2, &hdr->addr1, 3 * ETH_ALEN);
663 }
664
665
666 static inline void bip_ipn_set64(u8 *d, u64 pn)
667 {
668 *d++ = pn;
669 *d++ = pn >> 8;
670 *d++ = pn >> 16;
671 *d++ = pn >> 24;
672 *d++ = pn >> 32;
673 *d = pn >> 40;
674 }
675
676 static inline void bip_ipn_swap(u8 *d, const u8 *s)
677 {
678 *d++ = s[5];
679 *d++ = s[4];
680 *d++ = s[3];
681 *d++ = s[2];
682 *d++ = s[1];
683 *d = s[0];
684 }
685
686
687 ieee80211_tx_result
688 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
689 {
690 struct sk_buff *skb;
691 struct ieee80211_tx_info *info;
692 struct ieee80211_key *key = tx->key;
693 struct ieee80211_mmie *mmie;
694 u8 aad[20];
695 u64 pn64;
696
697 if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
698 return TX_DROP;
699
700 skb = skb_peek(&tx->skbs);
701
702 info = IEEE80211_SKB_CB(skb);
703
704 if (info->control.hw_key)
705 return TX_CONTINUE;
706
707 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
708 return TX_DROP;
709
710 mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie));
711 mmie->element_id = WLAN_EID_MMIE;
712 mmie->length = sizeof(*mmie) - 2;
713 mmie->key_id = cpu_to_le16(key->conf.keyidx);
714
715 /* PN = PN + 1 */
716 pn64 = atomic64_inc_return(&key->u.aes_cmac.tx_pn);
717
718 bip_ipn_set64(mmie->sequence_number, pn64);
719
720 bip_aad(skb, aad);
721
722 /*
723 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
724 */
725 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
726 skb->data + 24, skb->len - 24, mmie->mic);
727
728 return TX_CONTINUE;
729 }
730
731
732 ieee80211_rx_result
733 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
734 {
735 struct sk_buff *skb = rx->skb;
736 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
737 struct ieee80211_key *key = rx->key;
738 struct ieee80211_mmie *mmie;
739 u8 aad[20], mic[8], ipn[6];
740 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
741
742 if (!ieee80211_is_mgmt(hdr->frame_control))
743 return RX_CONTINUE;
744
745 /* management frames are already linear */
746
747 if (skb->len < 24 + sizeof(*mmie))
748 return RX_DROP_UNUSABLE;
749
750 mmie = (struct ieee80211_mmie *)
751 (skb->data + skb->len - sizeof(*mmie));
752 if (mmie->element_id != WLAN_EID_MMIE ||
753 mmie->length != sizeof(*mmie) - 2)
754 return RX_DROP_UNUSABLE; /* Invalid MMIE */
755
756 bip_ipn_swap(ipn, mmie->sequence_number);
757
758 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
759 key->u.aes_cmac.replays++;
760 return RX_DROP_UNUSABLE;
761 }
762
763 if (!(status->flag & RX_FLAG_DECRYPTED)) {
764 /* hardware didn't decrypt/verify MIC */
765 bip_aad(skb, aad);
766 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
767 skb->data + 24, skb->len - 24, mic);
768 if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
769 key->u.aes_cmac.icverrors++;
770 return RX_DROP_UNUSABLE;
771 }
772 }
773
774 memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
775
776 /* Remove MMIE */
777 skb_trim(skb, skb->len - sizeof(*mmie));
778
779 return RX_CONTINUE;
780 }
781
782 ieee80211_tx_result
783 ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx)
784 {
785 struct sk_buff *skb;
786 struct ieee80211_tx_info *info = NULL;
787 ieee80211_tx_result res;
788
789 skb_queue_walk(&tx->skbs, skb) {
790 info = IEEE80211_SKB_CB(skb);
791
792 /* handle hw-only algorithm */
793 if (!info->control.hw_key)
794 return TX_DROP;
795
796 if (tx->key->sta->cipher_scheme) {
797 res = ieee80211_crypto_cs_encrypt(tx, skb);
798 if (res != TX_CONTINUE)
799 return res;
800 }
801 }
802
803 ieee80211_tx_set_protected(tx);
804
805 return TX_CONTINUE;
806 }
807
808 ieee80211_rx_result
809 ieee80211_crypto_hw_decrypt(struct ieee80211_rx_data *rx)
810 {
811 if (rx->sta->cipher_scheme)
812 return ieee80211_crypto_cs_decrypt(rx);
813
814 return RX_DROP_UNUSABLE;
815 }