xref: /openbmc/linux/net/mac80211/wpa.c (revision 643d1f7f) 
1 /*
2  * Copyright 2002-2004, Instant802 Networks, Inc.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 
9 #include <linux/netdevice.h>
10 #include <linux/types.h>
11 #include <linux/slab.h>
12 #include <linux/skbuff.h>
13 #include <linux/compiler.h>
14 #include <net/mac80211.h>
15 
16 #include "ieee80211_i.h"
17 #include "michael.h"
18 #include "tkip.h"
19 #include "aes_ccm.h"
20 #include "wpa.h"
21 
22 static int ieee80211_get_hdr_info(const struct sk_buff *skb, u8 **sa, u8 **da,
23 				  u8 *qos_tid, u8 **data, size_t *data_len)
24 {
25 	struct ieee80211_hdr *hdr;
26 	size_t hdrlen;
27 	u16 fc;
28 	int a4_included;
29 	u8 *pos;
30 
31 	hdr = (struct ieee80211_hdr *) skb->data;
32 	fc = le16_to_cpu(hdr->frame_control);
33 
34 	hdrlen = 24;
35 	if ((fc & (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) ==
36 	    (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
37 		hdrlen += ETH_ALEN;
38 		*sa = hdr->addr4;
39 		*da = hdr->addr3;
40 	} else if (fc & IEEE80211_FCTL_FROMDS) {
41 		*sa = hdr->addr3;
42 		*da = hdr->addr1;
43 	} else if (fc & IEEE80211_FCTL_TODS) {
44 		*sa = hdr->addr2;
45 		*da = hdr->addr3;
46 	} else {
47 		*sa = hdr->addr2;
48 		*da = hdr->addr1;
49 	}
50 
51 	if (fc & 0x80)
52 		hdrlen += 2;
53 
54 	*data = skb->data + hdrlen;
55 	*data_len = skb->len - hdrlen;
56 
57 	a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
58 		(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
59 	if ((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
60 	    fc & IEEE80211_STYPE_QOS_DATA) {
61 		pos = (u8 *) &hdr->addr4;
62 		if (a4_included)
63 			pos += 6;
64 		*qos_tid = pos[0] & 0x0f;
65 		*qos_tid |= 0x80; /* qos_included flag */
66 	} else
67 		*qos_tid = 0;
68 
69 	return skb->len < hdrlen ? -1 : 0;
70 }
71 
72 
73 ieee80211_txrx_result
74 ieee80211_tx_h_michael_mic_add(struct ieee80211_txrx_data *tx)
75 {
76 	u8 *data, *sa, *da, *key, *mic, qos_tid;
77 	size_t data_len;
78 	u16 fc;
79 	struct sk_buff *skb = tx->skb;
80 	int authenticator;
81 	int wpa_test = 0;
82 
83 	fc = tx->fc;
84 
85 	if (!tx->key || tx->key->conf.alg != ALG_TKIP || skb->len < 24 ||
86 	    !WLAN_FC_DATA_PRESENT(fc))
87 		return TXRX_CONTINUE;
88 
89 	if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len))
90 		return TXRX_DROP;
91 
92 	if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
93 	    !(tx->flags & IEEE80211_TXRXD_FRAGMENTED) &&
94 	    !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) &&
95 	    !wpa_test) {
96 		/* hwaccel - with no need for preallocated room for Michael MIC
97 		 */
98 		return TXRX_CONTINUE;
99 	}
100 
101 	if (skb_tailroom(skb) < MICHAEL_MIC_LEN) {
102 		I802_DEBUG_INC(tx->local->tx_expand_skb_head);
103 		if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN,
104 					      MICHAEL_MIC_LEN + TKIP_ICV_LEN,
105 					      GFP_ATOMIC))) {
106 			printk(KERN_DEBUG "%s: failed to allocate more memory "
107 			       "for Michael MIC\n", tx->dev->name);
108 			return TXRX_DROP;
109 		}
110 	}
111 
112 #if 0
113 	authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
114 #else
115 	authenticator = 1;
116 #endif
117 	key = &tx->key->conf.key[authenticator ? ALG_TKIP_TEMP_AUTH_TX_MIC_KEY :
118 				 ALG_TKIP_TEMP_AUTH_RX_MIC_KEY];
119 	mic = skb_put(skb, MICHAEL_MIC_LEN);
120 	michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
121 
122 	return TXRX_CONTINUE;
123 }
124 
125 
126 ieee80211_txrx_result
127 ieee80211_rx_h_michael_mic_verify(struct ieee80211_txrx_data *rx)
128 {
129 	u8 *data, *sa, *da, *key = NULL, qos_tid;
130 	size_t data_len;
131 	u16 fc;
132 	u8 mic[MICHAEL_MIC_LEN];
133 	struct sk_buff *skb = rx->skb;
134 	int authenticator = 1, wpa_test = 0;
135 	DECLARE_MAC_BUF(mac);
136 
137 	fc = rx->fc;
138 
139 	/*
140 	 * No way to verify the MIC if the hardware stripped it
141 	 */
142 	if (rx->u.rx.status->flag & RX_FLAG_MMIC_STRIPPED)
143 		return TXRX_CONTINUE;
144 
145 	if (!rx->key || rx->key->conf.alg != ALG_TKIP ||
146 	    !(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc))
147 		return TXRX_CONTINUE;
148 
149 	if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)
150 	    || data_len < MICHAEL_MIC_LEN)
151 		return TXRX_DROP;
152 
153 	data_len -= MICHAEL_MIC_LEN;
154 
155 #if 0
156 	authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
157 #else
158 	authenticator = 1;
159 #endif
160 	key = &rx->key->conf.key[authenticator ? ALG_TKIP_TEMP_AUTH_RX_MIC_KEY :
161 				 ALG_TKIP_TEMP_AUTH_TX_MIC_KEY];
162 	michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
163 	if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) {
164 		if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
165 			return TXRX_DROP;
166 
167 		printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from "
168 		       "%s\n", rx->dev->name, print_mac(mac, sa));
169 
170 		mac80211_ev_michael_mic_failure(rx->dev, rx->key->conf.keyidx,
171 						(void *) skb->data);
172 		return TXRX_DROP;
173 	}
174 
175 	/* remove Michael MIC from payload */
176 	skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
177 
178 	/* update IV in key information to be able to detect replays */
179 	rx->key->u.tkip.iv32_rx[rx->u.rx.queue] = rx->u.rx.tkip_iv32;
180 	rx->key->u.tkip.iv16_rx[rx->u.rx.queue] = rx->u.rx.tkip_iv16;
181 
182 	return TXRX_CONTINUE;
183 }
184 
185 
186 static int tkip_encrypt_skb(struct ieee80211_txrx_data *tx,
187 			    struct sk_buff *skb, int test)
188 {
189 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
190 	struct ieee80211_key *key = tx->key;
191 	int hdrlen, len, tailneed;
192 	u16 fc;
193 	u8 *pos;
194 
195 	fc = le16_to_cpu(hdr->frame_control);
196 	hdrlen = ieee80211_get_hdrlen(fc);
197 	len = skb->len - hdrlen;
198 
199 	if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
200 		tailneed = 0;
201 	else
202 		tailneed = TKIP_ICV_LEN;
203 
204 	if ((skb_headroom(skb) < TKIP_IV_LEN ||
205 	     skb_tailroom(skb) < tailneed)) {
206 		I802_DEBUG_INC(tx->local->tx_expand_skb_head);
207 		if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN, tailneed,
208 					      GFP_ATOMIC)))
209 			return -1;
210 	}
211 
212 	pos = skb_push(skb, TKIP_IV_LEN);
213 	memmove(pos, pos + TKIP_IV_LEN, hdrlen);
214 	pos += hdrlen;
215 
216 	/* Increase IV for the frame */
217 	key->u.tkip.iv16++;
218 	if (key->u.tkip.iv16 == 0)
219 		key->u.tkip.iv32++;
220 
221 	if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
222 		hdr = (struct ieee80211_hdr *)skb->data;
223 
224 		/* hwaccel - with preallocated room for IV */
225 		ieee80211_tkip_add_iv(pos, key,
226 				      (u8) (key->u.tkip.iv16 >> 8),
227 				      (u8) (((key->u.tkip.iv16 >> 8) | 0x20) &
228 					    0x7f),
229 				      (u8) key->u.tkip.iv16);
230 
231 		tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx;
232 		return 0;
233 	}
234 
235 	/* Add room for ICV */
236 	skb_put(skb, TKIP_ICV_LEN);
237 
238 	hdr = (struct ieee80211_hdr *) skb->data;
239 	ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
240 				    key, pos, len, hdr->addr2);
241 	return 0;
242 }
243 
244 
245 ieee80211_txrx_result
246 ieee80211_crypto_tkip_encrypt(struct ieee80211_txrx_data *tx)
247 {
248 	struct sk_buff *skb = tx->skb;
249 	int wpa_test = 0, test = 0;
250 
251 	tx->u.tx.control->icv_len = TKIP_ICV_LEN;
252 	tx->u.tx.control->iv_len = TKIP_IV_LEN;
253 	ieee80211_tx_set_iswep(tx);
254 
255 	if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
256 	    !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
257 	    !wpa_test) {
258 		/* hwaccel - with no need for preallocated room for IV/ICV */
259 		tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx;
260 		return TXRX_CONTINUE;
261 	}
262 
263 	if (tkip_encrypt_skb(tx, skb, test) < 0)
264 		return TXRX_DROP;
265 
266 	if (tx->u.tx.extra_frag) {
267 		int i;
268 		for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
269 			if (tkip_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
270 			    < 0)
271 				return TXRX_DROP;
272 		}
273 	}
274 
275 	return TXRX_CONTINUE;
276 }
277 
278 
279 ieee80211_txrx_result
280 ieee80211_crypto_tkip_decrypt(struct ieee80211_txrx_data *rx)
281 {
282 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
283 	u16 fc;
284 	int hdrlen, res, hwaccel = 0, wpa_test = 0;
285 	struct ieee80211_key *key = rx->key;
286 	struct sk_buff *skb = rx->skb;
287 	DECLARE_MAC_BUF(mac);
288 
289 	fc = le16_to_cpu(hdr->frame_control);
290 	hdrlen = ieee80211_get_hdrlen(fc);
291 
292 	if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
293 		return TXRX_CONTINUE;
294 
295 	if (!rx->sta || skb->len - hdrlen < 12)
296 		return TXRX_DROP;
297 
298 	if (rx->u.rx.status->flag & RX_FLAG_DECRYPTED) {
299 		if (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED) {
300 			/*
301 			 * Hardware took care of all processing, including
302 			 * replay protection, and stripped the ICV/IV so
303 			 * we cannot do any checks here.
304 			 */
305 			return TXRX_CONTINUE;
306 		}
307 
308 		/* let TKIP code verify IV, but skip decryption */
309 		hwaccel = 1;
310 	}
311 
312 	res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
313 					  key, skb->data + hdrlen,
314 					  skb->len - hdrlen, rx->sta->addr,
315 					  hwaccel, rx->u.rx.queue,
316 					  &rx->u.rx.tkip_iv32,
317 					  &rx->u.rx.tkip_iv16);
318 	if (res != TKIP_DECRYPT_OK || wpa_test) {
319 #ifdef CONFIG_MAC80211_DEBUG
320 		if (net_ratelimit())
321 			printk(KERN_DEBUG "%s: TKIP decrypt failed for RX "
322 			       "frame from %s (res=%d)\n", rx->dev->name,
323 			       print_mac(mac, rx->sta->addr), res);
324 #endif /* CONFIG_MAC80211_DEBUG */
325 		return TXRX_DROP;
326 	}
327 
328 	/* Trim ICV */
329 	skb_trim(skb, skb->len - TKIP_ICV_LEN);
330 
331 	/* Remove IV */
332 	memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
333 	skb_pull(skb, TKIP_IV_LEN);
334 
335 	return TXRX_CONTINUE;
336 }
337 
338 
339 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
340 				int encrypted)
341 {
342 	u16 fc;
343 	int a4_included, qos_included;
344 	u8 qos_tid, *fc_pos, *data, *sa, *da;
345 	int len_a;
346 	size_t data_len;
347 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
348 
349 	fc_pos = (u8 *) &hdr->frame_control;
350 	fc = fc_pos[0] ^ (fc_pos[1] << 8);
351 	a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
352 		(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
353 
354 	ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len);
355 	data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0);
356 	if (qos_tid & 0x80) {
357 		qos_included = 1;
358 		qos_tid &= 0x0f;
359 	} else
360 		qos_included = 0;
361 	/* First block, b_0 */
362 
363 	b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
364 	/* Nonce: QoS Priority | A2 | PN */
365 	b_0[1] = qos_tid;
366 	memcpy(&b_0[2], hdr->addr2, 6);
367 	memcpy(&b_0[8], pn, CCMP_PN_LEN);
368 	/* l(m) */
369 	b_0[14] = (data_len >> 8) & 0xff;
370 	b_0[15] = data_len & 0xff;
371 
372 
373 	/* AAD (extra authenticate-only data) / masked 802.11 header
374 	 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
375 
376 	len_a = a4_included ? 28 : 22;
377 	if (qos_included)
378 		len_a += 2;
379 
380 	aad[0] = 0; /* (len_a >> 8) & 0xff; */
381 	aad[1] = len_a & 0xff;
382 	/* Mask FC: zero subtype b4 b5 b6 */
383 	aad[2] = fc_pos[0] & ~(BIT(4) | BIT(5) | BIT(6));
384 	/* Retry, PwrMgt, MoreData; set Protected */
385 	aad[3] = (fc_pos[1] & ~(BIT(3) | BIT(4) | BIT(5))) | BIT(6);
386 	memcpy(&aad[4], &hdr->addr1, 18);
387 
388 	/* Mask Seq#, leave Frag# */
389 	aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
390 	aad[23] = 0;
391 	if (a4_included) {
392 		memcpy(&aad[24], hdr->addr4, 6);
393 		aad[30] = 0;
394 		aad[31] = 0;
395 	} else
396 		memset(&aad[24], 0, 8);
397 	if (qos_included) {
398 		u8 *dpos = &aad[a4_included ? 30 : 24];
399 
400 		/* Mask QoS Control field */
401 		dpos[0] = qos_tid;
402 		dpos[1] = 0;
403 	}
404 }
405 
406 
407 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
408 {
409 	hdr[0] = pn[5];
410 	hdr[1] = pn[4];
411 	hdr[2] = 0;
412 	hdr[3] = 0x20 | (key_id << 6);
413 	hdr[4] = pn[3];
414 	hdr[5] = pn[2];
415 	hdr[6] = pn[1];
416 	hdr[7] = pn[0];
417 }
418 
419 
420 static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr)
421 {
422 	pn[0] = hdr[7];
423 	pn[1] = hdr[6];
424 	pn[2] = hdr[5];
425 	pn[3] = hdr[4];
426 	pn[4] = hdr[1];
427 	pn[5] = hdr[0];
428 	return (hdr[3] >> 6) & 0x03;
429 }
430 
431 
432 static int ccmp_encrypt_skb(struct ieee80211_txrx_data *tx,
433 			    struct sk_buff *skb, int test)
434 {
435 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
436 	struct ieee80211_key *key = tx->key;
437 	int hdrlen, len, tailneed;
438 	u16 fc;
439 	u8 *pos, *pn, *b_0, *aad, *scratch;
440 	int i;
441 
442 	scratch = key->u.ccmp.tx_crypto_buf;
443 	b_0 = scratch + 3 * AES_BLOCK_LEN;
444 	aad = scratch + 4 * AES_BLOCK_LEN;
445 
446 	fc = le16_to_cpu(hdr->frame_control);
447 	hdrlen = ieee80211_get_hdrlen(fc);
448 	len = skb->len - hdrlen;
449 
450 	if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
451 		tailneed = 0;
452 	else
453 		tailneed = CCMP_MIC_LEN;
454 
455 	if ((skb_headroom(skb) < CCMP_HDR_LEN ||
456 	     skb_tailroom(skb) < tailneed)) {
457 		I802_DEBUG_INC(tx->local->tx_expand_skb_head);
458 		if (unlikely(pskb_expand_head(skb, CCMP_HDR_LEN, tailneed,
459 					      GFP_ATOMIC)))
460 			return -1;
461 	}
462 
463 	pos = skb_push(skb, CCMP_HDR_LEN);
464 	memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
465 	hdr = (struct ieee80211_hdr *) pos;
466 	pos += hdrlen;
467 
468 	/* PN = PN + 1 */
469 	pn = key->u.ccmp.tx_pn;
470 
471 	for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
472 		pn[i]++;
473 		if (pn[i])
474 			break;
475 	}
476 
477 	ccmp_pn2hdr(pos, pn, key->conf.keyidx);
478 
479 	if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
480 		/* hwaccel - with preallocated room for CCMP header */
481 		tx->u.tx.control->key_idx = key->conf.hw_key_idx;
482 		return 0;
483 	}
484 
485 	pos += CCMP_HDR_LEN;
486 	ccmp_special_blocks(skb, pn, b_0, aad, 0);
487 	ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, b_0, aad, pos, len,
488 				  pos, skb_put(skb, CCMP_MIC_LEN));
489 
490 	return 0;
491 }
492 
493 
494 ieee80211_txrx_result
495 ieee80211_crypto_ccmp_encrypt(struct ieee80211_txrx_data *tx)
496 {
497 	struct sk_buff *skb = tx->skb;
498 	int test = 0;
499 
500 	tx->u.tx.control->icv_len = CCMP_MIC_LEN;
501 	tx->u.tx.control->iv_len = CCMP_HDR_LEN;
502 	ieee80211_tx_set_iswep(tx);
503 
504 	if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
505 	    !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
506 		/* hwaccel - with no need for preallocated room for CCMP "
507 		 * header or MIC fields */
508 		tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx;
509 		return TXRX_CONTINUE;
510 	}
511 
512 	if (ccmp_encrypt_skb(tx, skb, test) < 0)
513 		return TXRX_DROP;
514 
515 	if (tx->u.tx.extra_frag) {
516 		int i;
517 		for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
518 			if (ccmp_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
519 			    < 0)
520 				return TXRX_DROP;
521 		}
522 	}
523 
524 	return TXRX_CONTINUE;
525 }
526 
527 
528 ieee80211_txrx_result
529 ieee80211_crypto_ccmp_decrypt(struct ieee80211_txrx_data *rx)
530 {
531 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
532 	u16 fc;
533 	int hdrlen;
534 	struct ieee80211_key *key = rx->key;
535 	struct sk_buff *skb = rx->skb;
536 	u8 pn[CCMP_PN_LEN];
537 	int data_len;
538 	DECLARE_MAC_BUF(mac);
539 
540 	fc = le16_to_cpu(hdr->frame_control);
541 	hdrlen = ieee80211_get_hdrlen(fc);
542 
543 	if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
544 		return TXRX_CONTINUE;
545 
546 	data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
547 	if (!rx->sta || data_len < 0)
548 		return TXRX_DROP;
549 
550 	if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
551 	    (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED))
552 		return TXRX_CONTINUE;
553 
554 	(void) ccmp_hdr2pn(pn, skb->data + hdrlen);
555 
556 	if (memcmp(pn, key->u.ccmp.rx_pn[rx->u.rx.queue], CCMP_PN_LEN) <= 0) {
557 #ifdef CONFIG_MAC80211_DEBUG
558 		u8 *ppn = key->u.ccmp.rx_pn[rx->u.rx.queue];
559 
560 		printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from "
561 		       "%s (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN "
562 		       "%02x%02x%02x%02x%02x%02x)\n", rx->dev->name,
563 		       print_mac(mac, rx->sta->addr),
564 		       pn[0], pn[1], pn[2], pn[3], pn[4], pn[5],
565 		       ppn[0], ppn[1], ppn[2], ppn[3], ppn[4], ppn[5]);
566 #endif /* CONFIG_MAC80211_DEBUG */
567 		key->u.ccmp.replays++;
568 		return TXRX_DROP;
569 	}
570 
571 	if (!(rx->u.rx.status->flag & RX_FLAG_DECRYPTED)) {
572 		/* hardware didn't decrypt/verify MIC */
573 		u8 *scratch, *b_0, *aad;
574 
575 		scratch = key->u.ccmp.rx_crypto_buf;
576 		b_0 = scratch + 3 * AES_BLOCK_LEN;
577 		aad = scratch + 4 * AES_BLOCK_LEN;
578 
579 		ccmp_special_blocks(skb, pn, b_0, aad, 1);
580 
581 		if (ieee80211_aes_ccm_decrypt(
582 			    key->u.ccmp.tfm, scratch, b_0, aad,
583 			    skb->data + hdrlen + CCMP_HDR_LEN, data_len,
584 			    skb->data + skb->len - CCMP_MIC_LEN,
585 			    skb->data + hdrlen + CCMP_HDR_LEN)) {
586 #ifdef CONFIG_MAC80211_DEBUG
587 			if (net_ratelimit())
588 				printk(KERN_DEBUG "%s: CCMP decrypt failed "
589 				       "for RX frame from %s\n", rx->dev->name,
590 				       print_mac(mac, rx->sta->addr));
591 #endif /* CONFIG_MAC80211_DEBUG */
592 			return TXRX_DROP;
593 		}
594 	}
595 
596 	memcpy(key->u.ccmp.rx_pn[rx->u.rx.queue], pn, CCMP_PN_LEN);
597 
598 	/* Remove CCMP header and MIC */
599 	skb_trim(skb, skb->len - CCMP_MIC_LEN);
600 	memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
601 	skb_pull(skb, CCMP_HDR_LEN);
602 
603 	return TXRX_CONTINUE;
604 }
605