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10#include <linux/netdevice.h>
11#include <linux/types.h>
12#include <linux/slab.h>
13#include <linux/skbuff.h>
14#include <linux/compiler.h>
15#include <linux/ieee80211.h>
16#include <asm/unaligned.h>
17#include <net/mac80211.h>
18
19#include "ieee80211_i.h"
20#include "michael.h"
21#include "tkip.h"
22#include "aes_ccm.h"
23#include "aes_cmac.h"
24#include "wpa.h"
25
26ieee80211_tx_result
27ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
28{
29 u8 *data, *key, *mic, key_offset;
30 size_t data_len;
31 unsigned int hdrlen;
32 struct ieee80211_hdr *hdr;
33 struct sk_buff *skb = tx->skb;
34 int authenticator;
35 int wpa_test = 0;
36 int tail;
37
38 hdr = (struct ieee80211_hdr *)skb->data;
39 if (!tx->key || tx->key->conf.alg != ALG_TKIP || skb->len < 24 ||
40 !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 ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
51 !(tx->flags & IEEE80211_TX_FRAGMENTED) &&
52 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) &&
53 !wpa_test) {
54
55 return TX_CONTINUE;
56 }
57
58 tail = MICHAEL_MIC_LEN;
59 if (!(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
60 tail += TKIP_ICV_LEN;
61
62 if (WARN_ON(skb_tailroom(skb) < tail ||
63 skb_headroom(skb) < TKIP_IV_LEN))
64 return TX_DROP;
65
66#if 0
67 authenticator = fc & IEEE80211_FCTL_FROMDS;
68#else
69 authenticator = 1;
70#endif
71 key_offset = authenticator ?
72 NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY :
73 NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY;
74 key = &tx->key->conf.key[key_offset];
75 mic = skb_put(skb, MICHAEL_MIC_LEN);
76 michael_mic(key, hdr, data, data_len, mic);
77
78 return TX_CONTINUE;
79}
80
81
82ieee80211_rx_result
83ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
84{
85 u8 *data, *key = NULL, key_offset;
86 size_t data_len;
87 unsigned int hdrlen;
88 struct ieee80211_hdr *hdr;
89 u8 mic[MICHAEL_MIC_LEN];
90 struct sk_buff *skb = rx->skb;
91 int authenticator = 1, wpa_test = 0;
92
93
94 if (rx->status->flag & RX_FLAG_MMIC_STRIPPED)
95 return RX_CONTINUE;
96
97 hdr = (struct ieee80211_hdr *)skb->data;
98 if (!rx->key || rx->key->conf.alg != ALG_TKIP ||
99 !ieee80211_has_protected(hdr->frame_control) ||
100 !ieee80211_is_data_present(hdr->frame_control))
101 return RX_CONTINUE;
102
103 hdrlen = ieee80211_hdrlen(hdr->frame_control);
104 if (skb->len < hdrlen + MICHAEL_MIC_LEN)
105 return RX_DROP_UNUSABLE;
106
107 data = skb->data + hdrlen;
108 data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;
109
110#if 0
111 authenticator = fc & IEEE80211_FCTL_TODS;
112#else
113 authenticator = 1;
114#endif
115 key_offset = authenticator ?
116 NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY :
117 NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY;
118 key = &rx->key->conf.key[key_offset];
119 michael_mic(key, hdr, data, data_len, mic);
120 if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) {
121 if (!(rx->flags & IEEE80211_RX_RA_MATCH))
122 return RX_DROP_UNUSABLE;
123
124 mac80211_ev_michael_mic_failure(rx->sdata, rx->key->conf.keyidx,
125 (void *) skb->data, NULL,
126 GFP_ATOMIC);
127 return RX_DROP_UNUSABLE;
128 }
129
130
131 skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
132
133
134 rx->key->u.tkip.rx[rx->queue].iv32 = rx->tkip_iv32;
135 rx->key->u.tkip.rx[rx->queue].iv16 = rx->tkip_iv16;
136
137 return RX_CONTINUE;
138}
139
140
141static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
142{
143 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
144 struct ieee80211_key *key = tx->key;
145 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
146 unsigned int hdrlen;
147 int len, tail;
148 u8 *pos;
149
150 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
151 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
152
153 info->control.hw_key = &tx->key->conf;
154 return 0;
155 }
156
157 hdrlen = ieee80211_hdrlen(hdr->frame_control);
158 len = skb->len - hdrlen;
159
160 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
161 tail = 0;
162 else
163 tail = TKIP_ICV_LEN;
164
165 if (WARN_ON(skb_tailroom(skb) < tail ||
166 skb_headroom(skb) < TKIP_IV_LEN))
167 return -1;
168
169 pos = skb_push(skb, TKIP_IV_LEN);
170 memmove(pos, pos + TKIP_IV_LEN, hdrlen);
171 pos += hdrlen;
172
173
174 key->u.tkip.tx.iv16++;
175 if (key->u.tkip.tx.iv16 == 0)
176 key->u.tkip.tx.iv32++;
177
178 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
179
180 ieee80211_tkip_add_iv(pos, key, key->u.tkip.tx.iv16);
181
182 info->control.hw_key = &tx->key->conf;
183 return 0;
184 }
185
186
187 skb_put(skb, TKIP_ICV_LEN);
188
189 hdr = (struct ieee80211_hdr *) skb->data;
190 ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
191 key, pos, len, hdr->addr2);
192 return 0;
193}
194
195
196ieee80211_tx_result
197ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
198{
199 struct sk_buff *skb = tx->skb;
200
201 ieee80211_tx_set_protected(tx);
202
203 do {
204 if (tkip_encrypt_skb(tx, skb) < 0)
205 return TX_DROP;
206 } while ((skb = skb->next));
207
208 return TX_CONTINUE;
209}
210
211
212ieee80211_rx_result
213ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
214{
215 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
216 int hdrlen, res, hwaccel = 0, wpa_test = 0;
217 struct ieee80211_key *key = rx->key;
218 struct sk_buff *skb = rx->skb;
219
220 hdrlen = ieee80211_hdrlen(hdr->frame_control);
221
222 if (!ieee80211_is_data(hdr->frame_control))
223 return RX_CONTINUE;
224
225 if (!rx->sta || skb->len - hdrlen < 12)
226 return RX_DROP_UNUSABLE;
227
228 if (rx->status->flag & RX_FLAG_DECRYPTED) {
229 if (rx->status->flag & RX_FLAG_IV_STRIPPED) {
230
231
232
233
234
235 return RX_CONTINUE;
236 }
237
238
239 hwaccel = 1;
240 }
241
242 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
243 key, skb->data + hdrlen,
244 skb->len - hdrlen, rx->sta->sta.addr,
245 hdr->addr1, hwaccel, rx->queue,
246 &rx->tkip_iv32,
247 &rx->tkip_iv16);
248 if (res != TKIP_DECRYPT_OK || wpa_test)
249 return RX_DROP_UNUSABLE;
250
251
252 skb_trim(skb, skb->len - TKIP_ICV_LEN);
253
254
255 memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
256 skb_pull(skb, TKIP_IV_LEN);
257
258 return RX_CONTINUE;
259}
260
261
262static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch,
263 int encrypted)
264{
265 __le16 mask_fc;
266 int a4_included, mgmt;
267 u8 qos_tid;
268 u8 *b_0, *aad;
269 u16 data_len, len_a;
270 unsigned int hdrlen;
271 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
272
273 b_0 = scratch + 3 * AES_BLOCK_LEN;
274 aad = scratch + 4 * AES_BLOCK_LEN;
275
276
277
278
279
280 mgmt = ieee80211_is_mgmt(hdr->frame_control);
281 mask_fc = hdr->frame_control;
282 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
283 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
284 if (!mgmt)
285 mask_fc &= ~cpu_to_le16(0x0070);
286 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
287
288 hdrlen = ieee80211_hdrlen(hdr->frame_control);
289 len_a = hdrlen - 2;
290 a4_included = ieee80211_has_a4(hdr->frame_control);
291
292 if (ieee80211_is_data_qos(hdr->frame_control))
293 qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
294 else
295 qos_tid = 0;
296
297 data_len = skb->len - hdrlen - CCMP_HDR_LEN;
298 if (encrypted)
299 data_len -= CCMP_MIC_LEN;
300
301
302 b_0[0] = 0x59;
303
304
305
306 b_0[1] = qos_tid | (mgmt << 4);
307 memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
308 memcpy(&b_0[8], pn, CCMP_PN_LEN);
309
310 put_unaligned_be16(data_len, &b_0[14]);
311
312
313
314 put_unaligned_be16(len_a, &aad[0]);
315 put_unaligned(mask_fc, (__le16 *)&aad[2]);
316 memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
317
318
319 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
320 aad[23] = 0;
321
322 if (a4_included) {
323 memcpy(&aad[24], hdr->addr4, ETH_ALEN);
324 aad[30] = qos_tid;
325 aad[31] = 0;
326 } else {
327 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
328 aad[24] = qos_tid;
329 }
330}
331
332
333static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
334{
335 hdr[0] = pn[5];
336 hdr[1] = pn[4];
337 hdr[2] = 0;
338 hdr[3] = 0x20 | (key_id << 6);
339 hdr[4] = pn[3];
340 hdr[5] = pn[2];
341 hdr[6] = pn[1];
342 hdr[7] = pn[0];
343}
344
345
346static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr)
347{
348 pn[0] = hdr[7];
349 pn[1] = hdr[6];
350 pn[2] = hdr[5];
351 pn[3] = hdr[4];
352 pn[4] = hdr[1];
353 pn[5] = hdr[0];
354}
355
356
357static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
358{
359 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
360 struct ieee80211_key *key = tx->key;
361 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
362 int hdrlen, len, tail;
363 u8 *pos, *pn;
364 int i;
365 bool skip_hw;
366
367 skip_hw = (tx->key->conf.flags & IEEE80211_KEY_FLAG_SW_MGMT) &&
368 ieee80211_is_mgmt(hdr->frame_control);
369
370 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
371 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
372 !skip_hw) {
373
374
375 info->control.hw_key = &tx->key->conf;
376 return 0;
377 }
378
379 hdrlen = ieee80211_hdrlen(hdr->frame_control);
380 len = skb->len - hdrlen;
381
382 if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
383 tail = 0;
384 else
385 tail = CCMP_MIC_LEN;
386
387 if (WARN_ON(skb_tailroom(skb) < tail ||
388 skb_headroom(skb) < CCMP_HDR_LEN))
389 return -1;
390
391 pos = skb_push(skb, CCMP_HDR_LEN);
392 memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
393 hdr = (struct ieee80211_hdr *) pos;
394 pos += hdrlen;
395
396
397 pn = key->u.ccmp.tx_pn;
398
399 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
400 pn[i]++;
401 if (pn[i])
402 break;
403 }
404
405 ccmp_pn2hdr(pos, pn, key->conf.keyidx);
406
407 if ((key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) && !skip_hw) {
408
409 info->control.hw_key = &tx->key->conf;
410 return 0;
411 }
412
413 pos += CCMP_HDR_LEN;
414 ccmp_special_blocks(skb, pn, key->u.ccmp.tx_crypto_buf, 0);
415 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, key->u.ccmp.tx_crypto_buf, pos, len,
416 pos, skb_put(skb, CCMP_MIC_LEN));
417
418 return 0;
419}
420
421
422ieee80211_tx_result
423ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx)
424{
425 struct sk_buff *skb = tx->skb;
426
427 ieee80211_tx_set_protected(tx);
428
429 do {
430 if (ccmp_encrypt_skb(tx, skb) < 0)
431 return TX_DROP;
432 } while ((skb = skb->next));
433
434 return TX_CONTINUE;
435}
436
437
438ieee80211_rx_result
439ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx)
440{
441 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
442 int hdrlen;
443 struct ieee80211_key *key = rx->key;
444 struct sk_buff *skb = rx->skb;
445 u8 pn[CCMP_PN_LEN];
446 int data_len;
447
448 hdrlen = ieee80211_hdrlen(hdr->frame_control);
449
450 if (!ieee80211_is_data(hdr->frame_control) &&
451 !ieee80211_is_robust_mgmt_frame(hdr))
452 return RX_CONTINUE;
453
454 data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
455 if (!rx->sta || data_len < 0)
456 return RX_DROP_UNUSABLE;
457
458 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
459 (rx->status->flag & RX_FLAG_IV_STRIPPED))
460 return RX_CONTINUE;
461
462 ccmp_hdr2pn(pn, skb->data + hdrlen);
463
464 if (memcmp(pn, key->u.ccmp.rx_pn[rx->queue], CCMP_PN_LEN) <= 0) {
465 key->u.ccmp.replays++;
466 return RX_DROP_UNUSABLE;
467 }
468
469 if (!(rx->status->flag & RX_FLAG_DECRYPTED)) {
470
471 ccmp_special_blocks(skb, pn, key->u.ccmp.rx_crypto_buf, 1);
472
473 if (ieee80211_aes_ccm_decrypt(
474 key->u.ccmp.tfm, key->u.ccmp.rx_crypto_buf,
475 skb->data + hdrlen + CCMP_HDR_LEN, data_len,
476 skb->data + skb->len - CCMP_MIC_LEN,
477 skb->data + hdrlen + CCMP_HDR_LEN))
478 return RX_DROP_UNUSABLE;
479 }
480
481 memcpy(key->u.ccmp.rx_pn[rx->queue], pn, CCMP_PN_LEN);
482
483
484 skb_trim(skb, skb->len - CCMP_MIC_LEN);
485 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
486 skb_pull(skb, CCMP_HDR_LEN);
487
488 return RX_CONTINUE;
489}
490
491
492static void bip_aad(struct sk_buff *skb, u8 *aad)
493{
494
495
496
497 aad[0] = skb->data[0];
498
499 aad[1] = skb->data[1] & ~(BIT(4) | BIT(5) | BIT(6));
500
501 memcpy(aad + 2, skb->data + 4, 3 * ETH_ALEN);
502}
503
504
505static inline void bip_ipn_swap(u8 *d, const u8 *s)
506{
507 *d++ = s[5];
508 *d++ = s[4];
509 *d++ = s[3];
510 *d++ = s[2];
511 *d++ = s[1];
512 *d = s[0];
513}
514
515
516ieee80211_tx_result
517ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
518{
519 struct sk_buff *skb = tx->skb;
520 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
521 struct ieee80211_key *key = tx->key;
522 struct ieee80211_mmie *mmie;
523 u8 *pn, aad[20];
524 int i;
525
526 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
527
528 info->control.hw_key = &tx->key->conf;
529 return 0;
530 }
531
532 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
533 return TX_DROP;
534
535 mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie));
536 mmie->element_id = WLAN_EID_MMIE;
537 mmie->length = sizeof(*mmie) - 2;
538 mmie->key_id = cpu_to_le16(key->conf.keyidx);
539
540
541 pn = key->u.aes_cmac.tx_pn;
542
543 for (i = sizeof(key->u.aes_cmac.tx_pn) - 1; i >= 0; i--) {
544 pn[i]++;
545 if (pn[i])
546 break;
547 }
548 bip_ipn_swap(mmie->sequence_number, pn);
549
550 bip_aad(skb, aad);
551
552
553
554
555 ieee80211_aes_cmac(key->u.aes_cmac.tfm, key->u.aes_cmac.tx_crypto_buf,
556 aad, skb->data + 24, skb->len - 24, mmie->mic);
557
558 return TX_CONTINUE;
559}
560
561
562ieee80211_rx_result
563ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
564{
565 struct sk_buff *skb = rx->skb;
566 struct ieee80211_key *key = rx->key;
567 struct ieee80211_mmie *mmie;
568 u8 aad[20], mic[8], ipn[6];
569 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
570
571 if (!ieee80211_is_mgmt(hdr->frame_control))
572 return RX_CONTINUE;
573
574 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
575 (rx->status->flag & RX_FLAG_IV_STRIPPED))
576 return RX_CONTINUE;
577
578 if (skb->len < 24 + sizeof(*mmie))
579 return RX_DROP_UNUSABLE;
580
581 mmie = (struct ieee80211_mmie *)
582 (skb->data + skb->len - sizeof(*mmie));
583 if (mmie->element_id != WLAN_EID_MMIE ||
584 mmie->length != sizeof(*mmie) - 2)
585 return RX_DROP_UNUSABLE;
586
587 bip_ipn_swap(ipn, mmie->sequence_number);
588
589 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
590 key->u.aes_cmac.replays++;
591 return RX_DROP_UNUSABLE;
592 }
593
594 if (!(rx->status->flag & RX_FLAG_DECRYPTED)) {
595
596 bip_aad(skb, aad);
597 ieee80211_aes_cmac(key->u.aes_cmac.tfm,
598 key->u.aes_cmac.rx_crypto_buf, aad,
599 skb->data + 24, skb->len - 24, mic);
600 if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
601 key->u.aes_cmac.icverrors++;
602 return RX_DROP_UNUSABLE;
603 }
604 }
605
606 memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
607
608
609 skb_trim(skb, skb->len - sizeof(*mmie));
610
611 return RX_CONTINUE;
612}
613
