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) 2020-2023 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/utils.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
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
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_U_AP_RX_GROUPCAST;
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_U_SHORT_MMIC;
154
155 if (skb_linearize(rx->skb))
156 return RX_DROP_U_OOM;
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_U_MMIC_FAIL;
192 }
193
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
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
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_U_SHORT_TKIP;
280
281 /* it may be possible to optimize this a bit more */
282 if (skb_linearize(rx->skb))
283 return RX_DROP_U_OOM;
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_U_TKIP_FAIL;
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 */
318 static u8 ccmp_gcmp_aad(struct sk_buff *skb, u8 *aad, bool spp_amsdu)
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_qos_ctl(hdr);
344
345 if (spp_amsdu)
346 qos_tid &= IEEE80211_QOS_CTL_TID_MASK |
347 IEEE80211_QOS_CTL_A_MSDU_PRESENT;
348 else
349 qos_tid &= IEEE80211_QOS_CTL_TID_MASK;
350
351 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_ORDER);
352 len_a += 2;
353 } else {
354 qos_tid = 0;
355 }
356
357 /* AAD (extra authenticate-only data) / masked 802.11 header
358 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
359 put_unaligned_be16(len_a, &aad[0]);
360 put_unaligned(mask_fc, (__le16 *)&aad[2]);
361 memcpy(&aad[4], &hdr->addrs, 3 * ETH_ALEN);
362
363 /* Mask Seq#, leave Frag# */
364 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
365 aad[23] = 0;
366
367 if (a4_included) {
368 memcpy(&aad[24], hdr->addr4, ETH_ALEN);
369 aad[30] = qos_tid;
370 aad[31] = 0;
371 } else {
372 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
373 aad[24] = qos_tid;
374 }
375
376 return qos_tid;
377 }
378
379 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
380 bool spp_amsdu)
381 {
382 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
383 u8 qos_tid = ccmp_gcmp_aad(skb, aad, spp_amsdu);
384
385 /* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC
386 * mode authentication are not allowed to collide, yet both are derived
387 * from this vector b_0. We only set L := 1 here to indicate that the
388 * data size can be represented in (L+1) bytes. The CCM layer will take
389 * care of storing the data length in the top (L+1) bytes and setting
390 * and clearing the other bits as is required to derive the two IVs.
391 */
392 b_0[0] = 0x1;
393
394 /* Nonce: Nonce Flags | A2 | PN
395 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)
396 */
397 b_0[1] = qos_tid | (ieee80211_is_mgmt(hdr->frame_control) << 4);
398 memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
399 memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN);
400 }
401
402 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
403 {
404 hdr[0] = pn[5];
405 hdr[1] = pn[4];
406 hdr[2] = 0;
407 hdr[3] = 0x20 | (key_id << 6);
408 hdr[4] = pn[3];
409 hdr[5] = pn[2];
410 hdr[6] = pn[1];
411 hdr[7] = pn[0];
412 }
413
414
415 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr)
416 {
417 pn[0] = hdr[7];
418 pn[1] = hdr[6];
419 pn[2] = hdr[5];
420 pn[3] = hdr[4];
421 pn[4] = hdr[1];
422 pn[5] = hdr[0];
423 }
424
425
426 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb,
427 unsigned int mic_len)
428 {
429 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
430 struct ieee80211_key *key = tx->key;
431 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
432 int hdrlen, len, tail;
433 u8 *pos;
434 u8 pn[6];
435 u64 pn64;
436 u8 aad[CCM_AAD_LEN];
437 u8 b_0[AES_BLOCK_SIZE];
438
439 if (info->control.hw_key &&
440 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
441 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
442 !((info->control.hw_key->flags &
443 IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
444 ieee80211_is_mgmt(hdr->frame_control))) {
445 /*
446 * hwaccel has no need for preallocated room for CCMP
447 * header or MIC fields
448 */
449 return 0;
450 }
451
452 hdrlen = ieee80211_hdrlen(hdr->frame_control);
453 len = skb->len - hdrlen;
454
455 if (info->control.hw_key)
456 tail = 0;
457 else
458 tail = mic_len;
459
460 if (WARN_ON(skb_tailroom(skb) < tail ||
461 skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN))
462 return -1;
463
464 pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN);
465 memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen);
466
467 /* the HW only needs room for the IV, but not the actual IV */
468 if (info->control.hw_key &&
469 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
470 return 0;
471
472 pos += hdrlen;
473
474 pn64 = atomic64_inc_return(&key->conf.tx_pn);
475
476 pn[5] = pn64;
477 pn[4] = pn64 >> 8;
478 pn[3] = pn64 >> 16;
479 pn[2] = pn64 >> 24;
480 pn[1] = pn64 >> 32;
481 pn[0] = pn64 >> 40;
482
483 ccmp_pn2hdr(pos, pn, key->conf.keyidx);
484
485 /* hwaccel - with software CCMP header */
486 if (info->control.hw_key)
487 return 0;
488
489 pos += IEEE80211_CCMP_HDR_LEN;
490 ccmp_special_blocks(skb, pn, b_0, aad,
491 key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU);
492 return ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,
493 skb_put(skb, mic_len));
494 }
495
496
497 ieee80211_tx_result
498 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx,
499 unsigned int mic_len)
500 {
501 struct sk_buff *skb;
502
503 ieee80211_tx_set_protected(tx);
504
505 skb_queue_walk(&tx->skbs, skb) {
506 if (ccmp_encrypt_skb(tx, skb, mic_len) < 0)
507 return TX_DROP;
508 }
509
510 return TX_CONTINUE;
511 }
512
513
514 ieee80211_rx_result
515 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
516 unsigned int mic_len)
517 {
518 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
519 int hdrlen;
520 struct ieee80211_key *key = rx->key;
521 struct sk_buff *skb = rx->skb;
522 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
523 u8 pn[IEEE80211_CCMP_PN_LEN];
524 int data_len;
525 int queue;
526
527 hdrlen = ieee80211_hdrlen(hdr->frame_control);
528
529 if (!ieee80211_is_data(hdr->frame_control) &&
530 !ieee80211_is_robust_mgmt_frame(skb))
531 return RX_CONTINUE;
532
533 if (status->flag & RX_FLAG_DECRYPTED) {
534 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_CCMP_HDR_LEN))
535 return RX_DROP_U_SHORT_CCMP;
536 if (status->flag & RX_FLAG_MIC_STRIPPED)
537 mic_len = 0;
538 } else {
539 if (skb_linearize(rx->skb))
540 return RX_DROP_U_OOM;
541 }
542
543 /* reload hdr - skb might have been reallocated */
544 hdr = (void *)rx->skb->data;
545
546 data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - mic_len;
547 if (!rx->sta || data_len < 0)
548 return RX_DROP_U_SHORT_CCMP;
549
550 if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
551 int res;
552
553 ccmp_hdr2pn(pn, skb->data + hdrlen);
554
555 queue = rx->security_idx;
556
557 res = memcmp(pn, key->u.ccmp.rx_pn[queue],
558 IEEE80211_CCMP_PN_LEN);
559 if (res < 0 ||
560 (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
561 key->u.ccmp.replays++;
562 return RX_DROP_U_REPLAY;
563 }
564
565 if (!(status->flag & RX_FLAG_DECRYPTED)) {
566 u8 aad[2 * AES_BLOCK_SIZE];
567 u8 b_0[AES_BLOCK_SIZE];
568 /* hardware didn't decrypt/verify MIC */
569 ccmp_special_blocks(skb, pn, b_0, aad,
570 key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU);
571
572 if (ieee80211_aes_ccm_decrypt(
573 key->u.ccmp.tfm, b_0, aad,
574 skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN,
575 data_len,
576 skb->data + skb->len - mic_len))
577 return RX_DROP_U_MIC_FAIL;
578 }
579
580 memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN);
581 if (unlikely(ieee80211_is_frag(hdr)))
582 memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN);
583 }
584
585 /* Remove CCMP header and MIC */
586 if (pskb_trim(skb, skb->len - mic_len))
587 return RX_DROP_U_SHORT_CCMP_MIC;
588 memmove(skb->data + IEEE80211_CCMP_HDR_LEN, skb->data, hdrlen);
589 skb_pull(skb, IEEE80211_CCMP_HDR_LEN);
590
591 return RX_CONTINUE;
592 }
593
594 static void gcmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *j_0, u8 *aad,
595 bool spp_amsdu)
596 {
597 struct ieee80211_hdr *hdr = (void *)skb->data;
598
599 memcpy(j_0, hdr->addr2, ETH_ALEN);
600 memcpy(&j_0[ETH_ALEN], pn, IEEE80211_GCMP_PN_LEN);
601 j_0[13] = 0;
602 j_0[14] = 0;
603 j_0[AES_BLOCK_SIZE - 1] = 0x01;
604
605 ccmp_gcmp_aad(skb, aad, spp_amsdu);
606 }
607
608 static inline void gcmp_pn2hdr(u8 *hdr, const u8 *pn, int key_id)
609 {
610 hdr[0] = pn[5];
611 hdr[1] = pn[4];
612 hdr[2] = 0;
613 hdr[3] = 0x20 | (key_id << 6);
614 hdr[4] = pn[3];
615 hdr[5] = pn[2];
616 hdr[6] = pn[1];
617 hdr[7] = pn[0];
618 }
619
620 static inline void gcmp_hdr2pn(u8 *pn, const u8 *hdr)
621 {
622 pn[0] = hdr[7];
623 pn[1] = hdr[6];
624 pn[2] = hdr[5];
625 pn[3] = hdr[4];
626 pn[4] = hdr[1];
627 pn[5] = hdr[0];
628 }
629
630 static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
631 {
632 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
633 struct ieee80211_key *key = tx->key;
634 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
635 int hdrlen, len, tail;
636 u8 *pos;
637 u8 pn[6];
638 u64 pn64;
639 u8 aad[GCM_AAD_LEN];
640 u8 j_0[AES_BLOCK_SIZE];
641
642 if (info->control.hw_key &&
643 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
644 !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
645 !((info->control.hw_key->flags &
646 IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
647 ieee80211_is_mgmt(hdr->frame_control))) {
648 /* hwaccel has no need for preallocated room for GCMP
649 * header or MIC fields
650 */
651 return 0;
652 }
653
654 hdrlen = ieee80211_hdrlen(hdr->frame_control);
655 len = skb->len - hdrlen;
656
657 if (info->control.hw_key)
658 tail = 0;
659 else
660 tail = IEEE80211_GCMP_MIC_LEN;
661
662 if (WARN_ON(skb_tailroom(skb) < tail ||
663 skb_headroom(skb) < IEEE80211_GCMP_HDR_LEN))
664 return -1;
665
666 pos = skb_push(skb, IEEE80211_GCMP_HDR_LEN);
667 memmove(pos, pos + IEEE80211_GCMP_HDR_LEN, hdrlen);
668 skb_set_network_header(skb, skb_network_offset(skb) +
669 IEEE80211_GCMP_HDR_LEN);
670
671 /* the HW only needs room for the IV, but not the actual IV */
672 if (info->control.hw_key &&
673 (info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
674 return 0;
675
676 pos += hdrlen;
677
678 pn64 = atomic64_inc_return(&key->conf.tx_pn);
679
680 pn[5] = pn64;
681 pn[4] = pn64 >> 8;
682 pn[3] = pn64 >> 16;
683 pn[2] = pn64 >> 24;
684 pn[1] = pn64 >> 32;
685 pn[0] = pn64 >> 40;
686
687 gcmp_pn2hdr(pos, pn, key->conf.keyidx);
688
689 /* hwaccel - with software GCMP header */
690 if (info->control.hw_key)
691 return 0;
692
693 pos += IEEE80211_GCMP_HDR_LEN;
694 gcmp_special_blocks(skb, pn, j_0, aad,
695 key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU);
696 return ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len,
697 skb_put(skb, IEEE80211_GCMP_MIC_LEN));
698 }
699
700 ieee80211_tx_result
701 ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data *tx)
702 {
703 struct sk_buff *skb;
704
705 ieee80211_tx_set_protected(tx);
706
707 skb_queue_walk(&tx->skbs, skb) {
708 if (gcmp_encrypt_skb(tx, skb) < 0)
709 return TX_DROP;
710 }
711
712 return TX_CONTINUE;
713 }
714
715 ieee80211_rx_result
716 ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx)
717 {
718 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
719 int hdrlen;
720 struct ieee80211_key *key = rx->key;
721 struct sk_buff *skb = rx->skb;
722 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
723 u8 pn[IEEE80211_GCMP_PN_LEN];
724 int data_len, queue, mic_len = IEEE80211_GCMP_MIC_LEN;
725
726 hdrlen = ieee80211_hdrlen(hdr->frame_control);
727
728 if (!ieee80211_is_data(hdr->frame_control) &&
729 !ieee80211_is_robust_mgmt_frame(skb))
730 return RX_CONTINUE;
731
732 if (status->flag & RX_FLAG_DECRYPTED) {
733 if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN))
734 return RX_DROP_U_SHORT_GCMP;
735 if (status->flag & RX_FLAG_MIC_STRIPPED)
736 mic_len = 0;
737 } else {
738 if (skb_linearize(rx->skb))
739 return RX_DROP_U_OOM;
740 }
741
742 /* reload hdr - skb might have been reallocated */
743 hdr = (void *)rx->skb->data;
744
745 data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - mic_len;
746 if (!rx->sta || data_len < 0)
747 return RX_DROP_U_SHORT_GCMP;
748
749 if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
750 int res;
751
752 gcmp_hdr2pn(pn, skb->data + hdrlen);
753
754 queue = rx->security_idx;
755
756 res = memcmp(pn, key->u.gcmp.rx_pn[queue],
757 IEEE80211_GCMP_PN_LEN);
758 if (res < 0 ||
759 (!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
760 key->u.gcmp.replays++;
761 return RX_DROP_U_REPLAY;
762 }
763
764 if (!(status->flag & RX_FLAG_DECRYPTED)) {
765 u8 aad[2 * AES_BLOCK_SIZE];
766 u8 j_0[AES_BLOCK_SIZE];
767 /* hardware didn't decrypt/verify MIC */
768 gcmp_special_blocks(skb, pn, j_0, aad,
769 key->conf.flags & IEEE80211_KEY_FLAG_SPP_AMSDU);
770
771 if (ieee80211_aes_gcm_decrypt(
772 key->u.gcmp.tfm, j_0, aad,
773 skb->data + hdrlen + IEEE80211_GCMP_HDR_LEN,
774 data_len,
775 skb->data + skb->len -
776 IEEE80211_GCMP_MIC_LEN))
777 return RX_DROP_U_MIC_FAIL;
778 }
779
780 memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN);
781 if (unlikely(ieee80211_is_frag(hdr)))
782 memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN);
783 }
784
785 /* Remove GCMP header and MIC */
786 if (pskb_trim(skb, skb->len - mic_len))
787 return RX_DROP_U_SHORT_GCMP_MIC;
788 memmove(skb->data + IEEE80211_GCMP_HDR_LEN, skb->data, hdrlen);
789 skb_pull(skb, IEEE80211_GCMP_HDR_LEN);
790
791 return RX_CONTINUE;
792 }
793
794 static void bip_aad(struct sk_buff *skb, u8 *aad)
795 {
796 __le16 mask_fc;
797 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
798
799 /* BIP AAD: FC(masked) || A1 || A2 || A3 */
800
801 /* FC type/subtype */
802 /* Mask FC Retry, PwrMgt, MoreData flags to zero */
803 mask_fc = hdr->frame_control;
804 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM |
805 IEEE80211_FCTL_MOREDATA);
806 put_unaligned(mask_fc, (__le16 *) &aad[0]);
807 /* A1 || A2 || A3 */
808 memcpy(aad + 2, &hdr->addrs, 3 * ETH_ALEN);
809 }
810
811
812 static inline void bip_ipn_set64(u8 *d, u64 pn)
813 {
814 *d++ = pn;
815 *d++ = pn >> 8;
816 *d++ = pn >> 16;
817 *d++ = pn >> 24;
818 *d++ = pn >> 32;
819 *d = pn >> 40;
820 }
821
822 static inline void bip_ipn_swap(u8 *d, const u8 *s)
823 {
824 *d++ = s[5];
825 *d++ = s[4];
826 *d++ = s[3];
827 *d++ = s[2];
828 *d++ = s[1];
829 *d = s[0];
830 }
831
832
833 ieee80211_tx_result
834 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
835 {
836 struct sk_buff *skb;
837 struct ieee80211_tx_info *info;
838 struct ieee80211_key *key = tx->key;
839 struct ieee80211_mmie *mmie;
840 u8 aad[20];
841 u64 pn64;
842
843 if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
844 return TX_DROP;
845
846 skb = skb_peek(&tx->skbs);
847
848 info = IEEE80211_SKB_CB(skb);
849
850 if (info->control.hw_key &&
851 !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE))
852 return TX_CONTINUE;
853
854 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
855 return TX_DROP;
856
857 mmie = skb_put(skb, sizeof(*mmie));
858 mmie->element_id = WLAN_EID_MMIE;
859 mmie->length = sizeof(*mmie) - 2;
860 mmie->key_id = cpu_to_le16(key->conf.keyidx);
861
862 /* PN = PN + 1 */
863 pn64 = atomic64_inc_return(&key->conf.tx_pn);
864
865 bip_ipn_set64(mmie->sequence_number, pn64);
866
867 if (info->control.hw_key)
868 return TX_CONTINUE;
869
870 bip_aad(skb, aad);
871
872 /*
873 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
874 */
875 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
876 skb->data + 24, skb->len - 24, mmie->mic);
877
878 return TX_CONTINUE;
879 }
880
881 ieee80211_tx_result
882 ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx)
883 {
884 struct sk_buff *skb;
885 struct ieee80211_tx_info *info;
886 struct ieee80211_key *key = tx->key;
887 struct ieee80211_mmie_16 *mmie;
888 u8 aad[20];
889 u64 pn64;
890
891 if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
892 return TX_DROP;
893
894 skb = skb_peek(&tx->skbs);
895
896 info = IEEE80211_SKB_CB(skb);
897
898 if (info->control.hw_key &&
899 !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE))
900 return TX_CONTINUE;
901
902 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
903 return TX_DROP;
904
905 mmie = skb_put(skb, sizeof(*mmie));
906 mmie->element_id = WLAN_EID_MMIE;
907 mmie->length = sizeof(*mmie) - 2;
908 mmie->key_id = cpu_to_le16(key->conf.keyidx);
909
910 /* PN = PN + 1 */
911 pn64 = atomic64_inc_return(&key->conf.tx_pn);
912
913 bip_ipn_set64(mmie->sequence_number, pn64);
914
915 if (info->control.hw_key)
916 return TX_CONTINUE;
917
918 bip_aad(skb, aad);
919
920 /* MIC = AES-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128)
921 */
922 ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
923 skb->data + 24, skb->len - 24, mmie->mic);
924
925 return TX_CONTINUE;
926 }
927
928 ieee80211_rx_result
929 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
930 {
931 struct sk_buff *skb = rx->skb;
932 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
933 struct ieee80211_key *key = rx->key;
934 struct ieee80211_mmie *mmie;
935 u8 aad[20], mic[8], ipn[6];
936 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
937
938 if (!ieee80211_is_mgmt(hdr->frame_control))
939 return RX_CONTINUE;
940
941 /* management frames are already linear */
942
943 if (skb->len < 24 + sizeof(*mmie))
944 return RX_DROP_U_SHORT_CMAC;
945
946 mmie = (struct ieee80211_mmie *)
947 (skb->data + skb->len - sizeof(*mmie));
948 if (mmie->element_id != WLAN_EID_MMIE ||
949 mmie->length != sizeof(*mmie) - 2)
950 return RX_DROP_U_BAD_MMIE; /* Invalid MMIE */
951
952 bip_ipn_swap(ipn, mmie->sequence_number);
953
954 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
955 key->u.aes_cmac.replays++;
956 return RX_DROP_U_REPLAY;
957 }
958
959 if (!(status->flag & RX_FLAG_DECRYPTED)) {
960 /* hardware didn't decrypt/verify MIC */
961 bip_aad(skb, aad);
962 ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
963 skb->data + 24, skb->len - 24, mic);
964 if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
965 key->u.aes_cmac.icverrors++;
966 return RX_DROP_U_MIC_FAIL;
967 }
968 }
969
970 memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
971
972 /* Remove MMIE */
973 skb_trim(skb, skb->len - sizeof(*mmie));
974
975 return RX_CONTINUE;
976 }
977
978 ieee80211_rx_result
979 ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx)
980 {
981 struct sk_buff *skb = rx->skb;
982 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
983 struct ieee80211_key *key = rx->key;
984 struct ieee80211_mmie_16 *mmie;
985 u8 aad[20], mic[16], ipn[6];
986 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
987
988 if (!ieee80211_is_mgmt(hdr->frame_control))
989 return RX_CONTINUE;
990
991 /* management frames are already linear */
992
993 if (skb->len < 24 + sizeof(*mmie))
994 return RX_DROP_U_SHORT_CMAC256;
995
996 mmie = (struct ieee80211_mmie_16 *)
997 (skb->data + skb->len - sizeof(*mmie));
998 if (mmie->element_id != WLAN_EID_MMIE ||
999 mmie->length != sizeof(*mmie) - 2)
1000 return RX_DROP_U_BAD_MMIE; /* Invalid MMIE */
1001
1002 bip_ipn_swap(ipn, mmie->sequence_number);
1003
1004 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
1005 key->u.aes_cmac.replays++;
1006 return RX_DROP_U_REPLAY;
1007 }
1008
1009 if (!(status->flag & RX_FLAG_DECRYPTED)) {
1010 /* hardware didn't decrypt/verify MIC */
1011 bip_aad(skb, aad);
1012 ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
1013 skb->data + 24, skb->len - 24, mic);
1014 if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1015 key->u.aes_cmac.icverrors++;
1016 return RX_DROP_U_MIC_FAIL;
1017 }
1018 }
1019
1020 memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
1021
1022 /* Remove MMIE */
1023 skb_trim(skb, skb->len - sizeof(*mmie));
1024
1025 return RX_CONTINUE;
1026 }
1027
1028 ieee80211_tx_result
1029 ieee80211_crypto_aes_gmac_encrypt(struct ieee80211_tx_data *tx)
1030 {
1031 struct sk_buff *skb;
1032 struct ieee80211_tx_info *info;
1033 struct ieee80211_key *key = tx->key;
1034 struct ieee80211_mmie_16 *mmie;
1035 struct ieee80211_hdr *hdr;
1036 u8 aad[GMAC_AAD_LEN];
1037 u64 pn64;
1038 u8 nonce[GMAC_NONCE_LEN];
1039
1040 if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
1041 return TX_DROP;
1042
1043 skb = skb_peek(&tx->skbs);
1044
1045 info = IEEE80211_SKB_CB(skb);
1046
1047 if (info->control.hw_key &&
1048 !(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIE))
1049 return TX_CONTINUE;
1050
1051 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
1052 return TX_DROP;
1053
1054 mmie = skb_put(skb, sizeof(*mmie));
1055 mmie->element_id = WLAN_EID_MMIE;
1056 mmie->length = sizeof(*mmie) - 2;
1057 mmie->key_id = cpu_to_le16(key->conf.keyidx);
1058
1059 /* PN = PN + 1 */
1060 pn64 = atomic64_inc_return(&key->conf.tx_pn);
1061
1062 bip_ipn_set64(mmie->sequence_number, pn64);
1063
1064 if (info->control.hw_key)
1065 return TX_CONTINUE;
1066
1067 bip_aad(skb, aad);
1068
1069 hdr = (struct ieee80211_hdr *)skb->data;
1070 memcpy(nonce, hdr->addr2, ETH_ALEN);
1071 bip_ipn_swap(nonce + ETH_ALEN, mmie->sequence_number);
1072
1073 /* MIC = AES-GMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */
1074 if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1075 skb->data + 24, skb->len - 24, mmie->mic) < 0)
1076 return TX_DROP;
1077
1078 return TX_CONTINUE;
1079 }
1080
1081 ieee80211_rx_result
1082 ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data *rx)
1083 {
1084 struct sk_buff *skb = rx->skb;
1085 struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
1086 struct ieee80211_key *key = rx->key;
1087 struct ieee80211_mmie_16 *mmie;
1088 u8 aad[GMAC_AAD_LEN], *mic, ipn[6], nonce[GMAC_NONCE_LEN];
1089 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
1090
1091 if (!ieee80211_is_mgmt(hdr->frame_control))
1092 return RX_CONTINUE;
1093
1094 /* management frames are already linear */
1095
1096 if (skb->len < 24 + sizeof(*mmie))
1097 return RX_DROP_U_SHORT_GMAC;
1098
1099 mmie = (struct ieee80211_mmie_16 *)
1100 (skb->data + skb->len - sizeof(*mmie));
1101 if (mmie->element_id != WLAN_EID_MMIE ||
1102 mmie->length != sizeof(*mmie) - 2)
1103 return RX_DROP_U_BAD_MMIE; /* Invalid MMIE */
1104
1105 bip_ipn_swap(ipn, mmie->sequence_number);
1106
1107 if (memcmp(ipn, key->u.aes_gmac.rx_pn, 6) <= 0) {
1108 key->u.aes_gmac.replays++;
1109 return RX_DROP_U_REPLAY;
1110 }
1111
1112 if (!(status->flag & RX_FLAG_DECRYPTED)) {
1113 /* hardware didn't decrypt/verify MIC */
1114 bip_aad(skb, aad);
1115
1116 memcpy(nonce, hdr->addr2, ETH_ALEN);
1117 memcpy(nonce + ETH_ALEN, ipn, 6);
1118
1119 mic = kmalloc(GMAC_MIC_LEN, GFP_ATOMIC);
1120 if (!mic)
1121 return RX_DROP_U_OOM;
1122 if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
1123 skb->data + 24, skb->len - 24,
1124 mic) < 0 ||
1125 crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
1126 key->u.aes_gmac.icverrors++;
1127 kfree(mic);
1128 return RX_DROP_U_MIC_FAIL;
1129 }
1130 kfree(mic);
1131 }
1132
1133 memcpy(key->u.aes_gmac.rx_pn, ipn, 6);
1134
1135 /* Remove MMIE */
1136 skb_trim(skb, skb->len - sizeof(*mmie));
1137
1138 return RX_CONTINUE;
1139 }
1140
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.