aboutsummaryrefslogtreecommitdiff
path: root/net/mac80211/wpa.c
blob: c628fa93f5746f201387983fb022e549d7d14a8a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
/*
 * Copyright 2002-2004, Instant802 Networks, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/compiler.h>
#include <net/mac80211.h>

#include "ieee80211_i.h"
#include "michael.h"
#include "tkip.h"
#include "aes_ccm.h"
#include "wpa.h"

static int ieee80211_get_hdr_info(const struct sk_buff *skb, u8 **sa, u8 **da,
				  u8 *qos_tid, u8 **data, size_t *data_len)
{
	struct ieee80211_hdr *hdr;
	size_t hdrlen;
	u16 fc;
	int a4_included;
	u8 *pos;

	hdr = (struct ieee80211_hdr *) skb->data;
	fc = le16_to_cpu(hdr->frame_control);

	hdrlen = 24;
	if ((fc & (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) ==
	    (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
		hdrlen += ETH_ALEN;
		*sa = hdr->addr4;
		*da = hdr->addr3;
	} else if (fc & IEEE80211_FCTL_FROMDS) {
		*sa = hdr->addr3;
		*da = hdr->addr1;
	} else if (fc & IEEE80211_FCTL_TODS) {
		*sa = hdr->addr2;
		*da = hdr->addr3;
	} else {
		*sa = hdr->addr2;
		*da = hdr->addr1;
	}

	if (fc & 0x80)
		hdrlen += 2;

	*data = skb->data + hdrlen;
	*data_len = skb->len - hdrlen;

	a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
		(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
	if ((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
	    fc & IEEE80211_STYPE_QOS_DATA) {
		pos = (u8 *) &hdr->addr4;
		if (a4_included)
			pos += 6;
		*qos_tid = pos[0] & 0x0f;
		*qos_tid |= 0x80; /* qos_included flag */
	} else
		*qos_tid = 0;

	return skb->len < hdrlen ? -1 : 0;
}


ieee80211_tx_result
ieee80211_tx_h_michael_mic_add(struct ieee80211_txrx_data *tx)
{
	u8 *data, *sa, *da, *key, *mic, qos_tid;
	size_t data_len;
	u16 fc;
	struct sk_buff *skb = tx->skb;
	int authenticator;
	int wpa_test = 0;

	fc = tx->fc;

	if (!tx->key || tx->key->conf.alg != ALG_TKIP || skb->len < 24 ||
	    !WLAN_FC_DATA_PRESENT(fc))
		return TX_CONTINUE;

	if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len))
		return TX_DROP;

	if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
	    !(tx->flags & IEEE80211_TXRXD_FRAGMENTED) &&
	    !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) &&
	    !wpa_test) {
		/* hwaccel - with no need for preallocated room for Michael MIC
		 */
		return TX_CONTINUE;
	}

	if (skb_tailroom(skb) < MICHAEL_MIC_LEN) {
		I802_DEBUG_INC(tx->local->tx_expand_skb_head);
		if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN,
					      MICHAEL_MIC_LEN + TKIP_ICV_LEN,
					      GFP_ATOMIC))) {
			printk(KERN_DEBUG "%s: failed to allocate more memory "
			       "for Michael MIC\n", tx->dev->name);
			return TX_DROP;
		}
	}

#if 0
	authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
#else
	authenticator = 1;
#endif
	key = &tx->key->conf.key[authenticator ? ALG_TKIP_TEMP_AUTH_TX_MIC_KEY :
				 ALG_TKIP_TEMP_AUTH_RX_MIC_KEY];
	mic = skb_put(skb, MICHAEL_MIC_LEN);
	michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);

	return TX_CONTINUE;
}


ieee80211_rx_result
ieee80211_rx_h_michael_mic_verify(struct ieee80211_txrx_data *rx)
{
	u8 *data, *sa, *da, *key = NULL, qos_tid;
	size_t data_len;
	u16 fc;
	u8 mic[MICHAEL_MIC_LEN];
	struct sk_buff *skb = rx->skb;
	int authenticator = 1, wpa_test = 0;
	DECLARE_MAC_BUF(mac);

	fc = rx->fc;

	/*
	 * No way to verify the MIC if the hardware stripped it
	 */
	if (rx->u.rx.status->flag & RX_FLAG_MMIC_STRIPPED)
		return RX_CONTINUE;

	if (!rx->key || rx->key->conf.alg != ALG_TKIP ||
	    !(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc))
		return RX_CONTINUE;

	if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)
	    || data_len < MICHAEL_MIC_LEN)
		return RX_DROP;

	data_len -= MICHAEL_MIC_LEN;

#if 0
	authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
#else
	authenticator = 1;
#endif
	key = &rx->key->conf.key[authenticator ? ALG_TKIP_TEMP_AUTH_RX_MIC_KEY :
				 ALG_TKIP_TEMP_AUTH_TX_MIC_KEY];
	michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
	if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) {
		if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
			return RX_DROP;

		printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from "
		       "%s\n", rx->dev->name, print_mac(mac, sa));

		mac80211_ev_michael_mic_failure(rx->dev, rx->key->conf.keyidx,
						(void *) skb->data);
		return RX_DROP;
	}

	/* remove Michael MIC from payload */
	skb_trim(skb, skb->len - MICHAEL_MIC_LEN);

	/* update IV in key information to be able to detect replays */
	rx->key->u.tkip.iv32_rx[rx->u.rx.queue] = rx->u.rx.tkip_iv32;
	rx->key->u.tkip.iv16_rx[rx->u.rx.queue] = rx->u.rx.tkip_iv16;

	return RX_CONTINUE;
}


static int tkip_encrypt_skb(struct ieee80211_txrx_data *tx,
			    struct sk_buff *skb, int test)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	struct ieee80211_key *key = tx->key;
	int hdrlen, len, tailneed;
	u16 fc;
	u8 *pos;

	fc = le16_to_cpu(hdr->frame_control);
	hdrlen = ieee80211_get_hdrlen(fc);
	len = skb->len - hdrlen;

	if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
		tailneed = 0;
	else
		tailneed = TKIP_ICV_LEN;

	if ((skb_headroom(skb) < TKIP_IV_LEN ||
	     skb_tailroom(skb) < tailneed)) {
		I802_DEBUG_INC(tx->local->tx_expand_skb_head);
		if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN, tailneed,
					      GFP_ATOMIC)))
			return -1;
	}

	pos = skb_push(skb, TKIP_IV_LEN);
	memmove(pos, pos + TKIP_IV_LEN, hdrlen);
	pos += hdrlen;

	/* Increase IV for the frame */
	key->u.tkip.iv16++;
	if (key->u.tkip.iv16 == 0)
		key->u.tkip.iv32++;

	if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
		hdr = (struct ieee80211_hdr *)skb->data;

		/* hwaccel - with preallocated room for IV */
		ieee80211_tkip_add_iv(pos, key,
				      (u8) (key->u.tkip.iv16 >> 8),
				      (u8) (((key->u.tkip.iv16 >> 8) | 0x20) &
					    0x7f),
				      (u8) key->u.tkip.iv16);

		tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx;
		return 0;
	}

	/* Add room for ICV */
	skb_put(skb, TKIP_ICV_LEN);

	hdr = (struct ieee80211_hdr *) skb->data;
	ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
				    key, pos, len, hdr->addr2);
	return 0;
}


ieee80211_tx_result
ieee80211_crypto_tkip_encrypt(struct ieee80211_txrx_data *tx)
{
	struct sk_buff *skb = tx->skb;
	int wpa_test = 0, test = 0;

	tx->u.tx.control->icv_len = TKIP_ICV_LEN;
	tx->u.tx.control->iv_len = TKIP_IV_LEN;
	ieee80211_tx_set_iswep(tx);

	if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
	    !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
	    !wpa_test) {
		/* hwaccel - with no need for preallocated room for IV/ICV */
		tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx;
		return TX_CONTINUE;
	}

	if (tkip_encrypt_skb(tx, skb, test) < 0)
		return TX_DROP;

	if (tx->u.tx.extra_frag) {
		int i;
		for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
			if (tkip_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
			    < 0)
				return TX_DROP;
		}
	}

	return TX_CONTINUE;
}


ieee80211_rx_result
ieee80211_crypto_tkip_decrypt(struct ieee80211_txrx_data *rx)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
	u16 fc;
	int hdrlen, res, hwaccel = 0, wpa_test = 0;
	struct ieee80211_key *key = rx->key;
	struct sk_buff *skb = rx->skb;
	DECLARE_MAC_BUF(mac);

	fc = le16_to_cpu(hdr->frame_control);
	hdrlen = ieee80211_get_hdrlen(fc);

	if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
		return RX_CONTINUE;

	if (!rx->sta || skb->len - hdrlen < 12)
		return RX_DROP;

	if (rx->u.rx.status->flag & RX_FLAG_DECRYPTED) {
		if (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED) {
			/*
			 * Hardware took care of all processing, including
			 * replay protection, and stripped the ICV/IV so
			 * we cannot do any checks here.
			 */
			return RX_CONTINUE;
		}

		/* let TKIP code verify IV, but skip decryption */
		hwaccel = 1;
	}

	res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
					  key, skb->data + hdrlen,
					  skb->len - hdrlen, rx->sta->addr,
					  hwaccel, rx->u.rx.queue,
					  &rx->u.rx.tkip_iv32,
					  &rx->u.rx.tkip_iv16);
	if (res != TKIP_DECRYPT_OK || wpa_test) {
#ifdef CONFIG_MAC80211_DEBUG
		if (net_ratelimit())
			printk(KERN_DEBUG "%s: TKIP decrypt failed for RX "
			       "frame from %s (res=%d)\n", rx->dev->name,
			       print_mac(mac, rx->sta->addr), res);
#endif /* CONFIG_MAC80211_DEBUG */
		return RX_DROP;
	}

	/* Trim ICV */
	skb_trim(skb, skb->len - TKIP_ICV_LEN);

	/* Remove IV */
	memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
	skb_pull(skb, TKIP_IV_LEN);

	return RX_CONTINUE;
}


static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
				int encrypted)
{
	u16 fc;
	int a4_included, qos_included;
	u8 qos_tid, *fc_pos, *data, *sa, *da;
	int len_a;
	size_t data_len;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;

	fc_pos = (u8 *) &hdr->frame_control;
	fc = fc_pos[0] ^ (fc_pos[1] << 8);
	a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
		(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);

	ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len);
	data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0);
	if (qos_tid & 0x80) {
		qos_included = 1;
		qos_tid &= 0x0f;
	} else
		qos_included = 0;
	/* First block, b_0 */

	b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
	/* Nonce: QoS Priority | A2 | PN */
	b_0[1] = qos_tid;
	memcpy(&b_0[2], hdr->addr2, 6);
	memcpy(&b_0[8], pn, CCMP_PN_LEN);
	/* l(m) */
	b_0[14] = (data_len >> 8) & 0xff;
	b_0[15] = data_len & 0xff;


	/* AAD (extra authenticate-only data) / masked 802.11 header
	 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */

	len_a = a4_included ? 28 : 22;
	if (qos_included)
		len_a += 2;

	aad[0] = 0; /* (len_a >> 8) & 0xff; */
	aad[1] = len_a & 0xff;
	/* Mask FC: zero subtype b4 b5 b6 */
	aad[2] = fc_pos[0] & ~(BIT(4) | BIT(5) | BIT(6));
	/* Retry, PwrMgt, MoreData; set Protected */
	aad[3] = (fc_pos[1] & ~(BIT(3) | BIT(4) | BIT(5))) | BIT(6);
	memcpy(&aad[4], &hdr->addr1, 18);

	/* Mask Seq#, leave Frag# */
	aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
	aad[23] = 0;
	if (a4_included) {
		memcpy(&aad[24], hdr->addr4, 6);
		aad[30] = 0;
		aad[31] = 0;
	} else
		memset(&aad[24], 0, 8);
	if (qos_included) {
		u8 *dpos = &aad[a4_included ? 30 : 24];

		/* Mask QoS Control field */
		dpos[0] = qos_tid;
		dpos[1] = 0;
	}
}


static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
{
	hdr[0] = pn[5];
	hdr[1] = pn[4];
	hdr[2] = 0;
	hdr[3] = 0x20 | (key_id << 6);
	hdr[4] = pn[3];
	hdr[5] = pn[2];
	hdr[6] = pn[1];
	hdr[7] = pn[0];
}


static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr)
{
	pn[0] = hdr[7];
	pn[1] = hdr[6];
	pn[2] = hdr[5];
	pn[3] = hdr[4];
	pn[4] = hdr[1];
	pn[5] = hdr[0];
	return (hdr[3] >> 6) & 0x03;
}


static int ccmp_encrypt_skb(struct ieee80211_txrx_data *tx,
			    struct sk_buff *skb, int test)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	struct ieee80211_key *key = tx->key;
	int hdrlen, len, tailneed;
	u16 fc;
	u8 *pos, *pn, *b_0, *aad, *scratch;
	int i;

	scratch = key->u.ccmp.tx_crypto_buf;
	b_0 = scratch + 3 * AES_BLOCK_LEN;
	aad = scratch + 4 * AES_BLOCK_LEN;

	fc = le16_to_cpu(hdr->frame_control);
	hdrlen = ieee80211_get_hdrlen(fc);
	len = skb->len - hdrlen;

	if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
		tailneed = 0;
	else
		tailneed = CCMP_MIC_LEN;

	if ((skb_headroom(skb) < CCMP_HDR_LEN ||
	     skb_tailroom(skb) < tailneed)) {
		I802_DEBUG_INC(tx->local->tx_expand_skb_head);
		if (unlikely(pskb_expand_head(skb, CCMP_HDR_LEN, tailneed,
					      GFP_ATOMIC)))
			return -1;
	}

	pos = skb_push(skb, CCMP_HDR_LEN);
	memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
	hdr = (struct ieee80211_hdr *) pos;
	pos += hdrlen;

	/* PN = PN + 1 */
	pn = key->u.ccmp.tx_pn;

	for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
		pn[i]++;
		if (pn[i])
			break;
	}

	ccmp_pn2hdr(pos, pn, key->conf.keyidx);

	if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
		/* hwaccel - with preallocated room for CCMP header */
		tx->u.tx.control->key_idx = key->conf.hw_key_idx;
		return 0;
	}

	pos += CCMP_HDR_LEN;
	ccmp_special_blocks(skb, pn, b_0, aad, 0);
	ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, b_0, aad, pos, len,
				  pos, skb_put(skb, CCMP_MIC_LEN));

	return 0;
}


ieee80211_tx_result
ieee80211_crypto_ccmp_encrypt(struct ieee80211_txrx_data *tx)
{
	struct sk_buff *skb = tx->skb;
	int test = 0;

	tx->u.tx.control->icv_len = CCMP_MIC_LEN;
	tx->u.tx.control->iv_len = CCMP_HDR_LEN;
	ieee80211_tx_set_iswep(tx);

	if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
	    !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
		/* hwaccel - with no need for preallocated room for CCMP "
		 * header or MIC fields */
		tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx;
		return TX_CONTINUE;
	}

	if (ccmp_encrypt_skb(tx, skb, test) < 0)
		return TX_DROP;

	if (tx->u.tx.extra_frag) {
		int i;
		for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
			if (ccmp_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
			    < 0)
				return TX_DROP;
		}
	}

	return TX_CONTINUE;
}


ieee80211_rx_result
ieee80211_crypto_ccmp_decrypt(struct ieee80211_txrx_data *rx)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
	u16 fc;
	int hdrlen;
	struct ieee80211_key *key = rx->key;
	struct sk_buff *skb = rx->skb;
	u8 pn[CCMP_PN_LEN];
	int data_len;
	DECLARE_MAC_BUF(mac);

	fc = le16_to_cpu(hdr->frame_control);
	hdrlen = ieee80211_get_hdrlen(fc);

	if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
		return RX_CONTINUE;

	data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
	if (!rx->sta || data_len < 0)
		return RX_DROP;

	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
	    (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED))
		return RX_CONTINUE;

	(void) ccmp_hdr2pn(pn, skb->data + hdrlen);

	if (memcmp(pn, key->u.ccmp.rx_pn[rx->u.rx.queue], CCMP_PN_LEN) <= 0) {
#ifdef CONFIG_MAC80211_DEBUG
		u8 *ppn = key->u.ccmp.rx_pn[rx->u.rx.queue];

		printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from "
		       "%s (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN "
		       "%02x%02x%02x%02x%02x%02x)\n", rx->dev->name,
		       print_mac(mac, rx->sta->addr),
		       pn[0], pn[1], pn[2], pn[3], pn[4], pn[5],
		       ppn[0], ppn[1], ppn[2], ppn[3], ppn[4], ppn[5]);
#endif /* CONFIG_MAC80211_DEBUG */
		key->u.ccmp.replays++;
		return RX_DROP;
	}

	if (!(rx->u.rx.status->flag & RX_FLAG_DECRYPTED)) {
		/* hardware didn't decrypt/verify MIC */
		u8 *scratch, *b_0, *aad;

		scratch = key->u.ccmp.rx_crypto_buf;
		b_0 = scratch + 3 * AES_BLOCK_LEN;
		aad = scratch + 4 * AES_BLOCK_LEN;

		ccmp_special_blocks(skb, pn, b_0, aad, 1);

		if (ieee80211_aes_ccm_decrypt(
			    key->u.ccmp.tfm, scratch, b_0, aad,
			    skb->data + hdrlen + CCMP_HDR_LEN, data_len,
			    skb->data + skb->len - CCMP_MIC_LEN,
			    skb->data + hdrlen + CCMP_HDR_LEN)) {
#ifdef CONFIG_MAC80211_DEBUG
			if (net_ratelimit())
				printk(KERN_DEBUG "%s: CCMP decrypt failed "
				       "for RX frame from %s\n", rx->dev->name,
				       print_mac(mac, rx->sta->addr));
#endif /* CONFIG_MAC80211_DEBUG */
			return RX_DROP;
		}
	}

	memcpy(key->u.ccmp.rx_pn[rx->u.rx.queue], pn, CCMP_PN_LEN);

	/* Remove CCMP header and MIC */
	skb_trim(skb, skb->len - CCMP_MIC_LEN);
	memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
	skb_pull(skb, CCMP_HDR_LEN);

	return RX_CONTINUE;
}