1/*-
2 * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include <sys/cdefs.h>
27__FBSDID("$FreeBSD$");
28
29/*
30 * IEEE 802.11i AES-CCMP crypto support.
31 *
32 * Part of this module is derived from similar code in the Host
33 * AP driver. The code is used with the consent of the author and
34 * it's license is included below.
35 */
36#include "opt_wlan.h"
37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/mbuf.h>
41#include <sys/malloc.h>
42#include <sys/kernel.h>
43#include <sys/module.h>
44
45#include <sys/socket.h>
46
47#include <net/if.h>
48#include <net/if_media.h>
49#include <net/ethernet.h>
50
51#include <net80211/ieee80211_var.h>
52
53#include <crypto/rijndael/rijndael.h>
54
55#define AES_BLOCK_LEN 16
56
57struct ccmp_ctx {
58	struct ieee80211vap *cc_vap;	/* for diagnostics+statistics */
59	struct ieee80211com *cc_ic;
60	rijndael_ctx	     cc_aes;
61};
62
63static	void *ccmp_attach(struct ieee80211vap *, struct ieee80211_key *);
64static	void ccmp_detach(struct ieee80211_key *);
65static	int ccmp_setkey(struct ieee80211_key *);
66static	int ccmp_encap(struct ieee80211_key *k, struct mbuf *, uint8_t keyid);
67static	int ccmp_decap(struct ieee80211_key *, struct mbuf *, int);
68static	int ccmp_enmic(struct ieee80211_key *, struct mbuf *, int);
69static	int ccmp_demic(struct ieee80211_key *, struct mbuf *, int);
70
71static const struct ieee80211_cipher ccmp = {
72	.ic_name	= "AES-CCM",
73	.ic_cipher	= IEEE80211_CIPHER_AES_CCM,
74	.ic_header	= IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN +
75			  IEEE80211_WEP_EXTIVLEN,
76	.ic_trailer	= IEEE80211_WEP_MICLEN,
77	.ic_miclen	= 0,
78	.ic_attach	= ccmp_attach,
79	.ic_detach	= ccmp_detach,
80	.ic_setkey	= ccmp_setkey,
81	.ic_encap	= ccmp_encap,
82	.ic_decap	= ccmp_decap,
83	.ic_enmic	= ccmp_enmic,
84	.ic_demic	= ccmp_demic,
85};
86
87static	int ccmp_encrypt(struct ieee80211_key *, struct mbuf *, int hdrlen);
88static	int ccmp_decrypt(struct ieee80211_key *, u_int64_t pn,
89		struct mbuf *, int hdrlen);
90
91/* number of references from net80211 layer */
92static	int nrefs = 0;
93
94static void *
95ccmp_attach(struct ieee80211vap *vap, struct ieee80211_key *k)
96{
97	struct ccmp_ctx *ctx;
98
99	ctx = (struct ccmp_ctx *) malloc(sizeof(struct ccmp_ctx),
100		M_80211_CRYPTO, M_NOWAIT | M_ZERO);
101	if (ctx == NULL) {
102		vap->iv_stats.is_crypto_nomem++;
103		return NULL;
104	}
105	ctx->cc_vap = vap;
106	ctx->cc_ic = vap->iv_ic;
107	nrefs++;			/* NB: we assume caller locking */
108	return ctx;
109}
110
111static void
112ccmp_detach(struct ieee80211_key *k)
113{
114	struct ccmp_ctx *ctx = k->wk_private;
115
116	free(ctx, M_80211_CRYPTO);
117	KASSERT(nrefs > 0, ("imbalanced attach/detach"));
118	nrefs--;			/* NB: we assume caller locking */
119}
120
121static int
122ccmp_setkey(struct ieee80211_key *k)
123{
124	struct ccmp_ctx *ctx = k->wk_private;
125
126	if (k->wk_keylen != (128/NBBY)) {
127		IEEE80211_DPRINTF(ctx->cc_vap, IEEE80211_MSG_CRYPTO,
128			"%s: Invalid key length %u, expecting %u\n",
129			__func__, k->wk_keylen, 128/NBBY);
130		return 0;
131	}
132	if (k->wk_flags & IEEE80211_KEY_SWENCRYPT)
133		rijndael_set_key(&ctx->cc_aes, k->wk_key, k->wk_keylen*NBBY);
134	return 1;
135}
136
137/*
138 * Add privacy headers appropriate for the specified key.
139 */
140static int
141ccmp_encap(struct ieee80211_key *k, struct mbuf *m, uint8_t keyid)
142{
143	struct ccmp_ctx *ctx = k->wk_private;
144	struct ieee80211com *ic = ctx->cc_ic;
145	uint8_t *ivp;
146	int hdrlen;
147
148	hdrlen = ieee80211_hdrspace(ic, mtod(m, void *));
149
150	/*
151	 * Copy down 802.11 header and add the IV, KeyID, and ExtIV.
152	 */
153	M_PREPEND(m, ccmp.ic_header, M_NOWAIT);
154	if (m == NULL)
155		return 0;
156	ivp = mtod(m, uint8_t *);
157	ovbcopy(ivp + ccmp.ic_header, ivp, hdrlen);
158	ivp += hdrlen;
159
160	k->wk_keytsc++;		/* XXX wrap at 48 bits */
161	ivp[0] = k->wk_keytsc >> 0;		/* PN0 */
162	ivp[1] = k->wk_keytsc >> 8;		/* PN1 */
163	ivp[2] = 0;				/* Reserved */
164	ivp[3] = keyid | IEEE80211_WEP_EXTIV;	/* KeyID | ExtID */
165	ivp[4] = k->wk_keytsc >> 16;		/* PN2 */
166	ivp[5] = k->wk_keytsc >> 24;		/* PN3 */
167	ivp[6] = k->wk_keytsc >> 32;		/* PN4 */
168	ivp[7] = k->wk_keytsc >> 40;		/* PN5 */
169
170	/*
171	 * Finally, do software encrypt if neeed.
172	 */
173	if ((k->wk_flags & IEEE80211_KEY_SWENCRYPT) &&
174	    !ccmp_encrypt(k, m, hdrlen))
175		return 0;
176
177	return 1;
178}
179
180/*
181 * Add MIC to the frame as needed.
182 */
183static int
184ccmp_enmic(struct ieee80211_key *k, struct mbuf *m, int force)
185{
186
187	return 1;
188}
189
190static __inline uint64_t
191READ_6(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3, uint8_t b4, uint8_t b5)
192{
193	uint32_t iv32 = (b0 << 0) | (b1 << 8) | (b2 << 16) | (b3 << 24);
194	uint16_t iv16 = (b4 << 0) | (b5 << 8);
195	return (((uint64_t)iv16) << 32) | iv32;
196}
197
198/*
199 * Validate and strip privacy headers (and trailer) for a
200 * received frame. The specified key should be correct but
201 * is also verified.
202 */
203static int
204ccmp_decap(struct ieee80211_key *k, struct mbuf *m, int hdrlen)
205{
206	struct ccmp_ctx *ctx = k->wk_private;
207	struct ieee80211vap *vap = ctx->cc_vap;
208	struct ieee80211_frame *wh;
209	uint8_t *ivp, tid;
210	uint64_t pn;
211
212	/*
213	 * Header should have extended IV and sequence number;
214	 * verify the former and validate the latter.
215	 */
216	wh = mtod(m, struct ieee80211_frame *);
217	ivp = mtod(m, uint8_t *) + hdrlen;
218	if ((ivp[IEEE80211_WEP_IVLEN] & IEEE80211_WEP_EXTIV) == 0) {
219		/*
220		 * No extended IV; discard frame.
221		 */
222		IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO, wh->i_addr2,
223			"%s", "missing ExtIV for AES-CCM cipher");
224		vap->iv_stats.is_rx_ccmpformat++;
225		return 0;
226	}
227	tid = ieee80211_gettid(wh);
228	pn = READ_6(ivp[0], ivp[1], ivp[4], ivp[5], ivp[6], ivp[7]);
229	if (pn <= k->wk_keyrsc[tid] &&
230	    (k->wk_flags & IEEE80211_KEY_NOREPLAY) == 0) {
231		/*
232		 * Replay violation.
233		 */
234		ieee80211_notify_replay_failure(vap, wh, k, pn, tid);
235		vap->iv_stats.is_rx_ccmpreplay++;
236		return 0;
237	}
238
239	/*
240	 * Check if the device handled the decrypt in hardware.
241	 * If so we just strip the header; otherwise we need to
242	 * handle the decrypt in software.  Note that for the
243	 * latter we leave the header in place for use in the
244	 * decryption work.
245	 */
246	if ((k->wk_flags & IEEE80211_KEY_SWDECRYPT) &&
247	    !ccmp_decrypt(k, pn, m, hdrlen))
248		return 0;
249
250	/*
251	 * Copy up 802.11 header and strip crypto bits.
252	 */
253	ovbcopy(mtod(m, void *), mtod(m, uint8_t *) + ccmp.ic_header, hdrlen);
254	m_adj(m, ccmp.ic_header);
255	m_adj(m, -ccmp.ic_trailer);
256
257	/*
258	 * Ok to update rsc now.
259	 */
260	k->wk_keyrsc[tid] = pn;
261
262	return 1;
263}
264
265/*
266 * Verify and strip MIC from the frame.
267 */
268static int
269ccmp_demic(struct ieee80211_key *k, struct mbuf *m, int force)
270{
271	return 1;
272}
273
274static __inline void
275xor_block(uint8_t *b, const uint8_t *a, size_t len)
276{
277	int i;
278	for (i = 0; i < len; i++)
279		b[i] ^= a[i];
280}
281
282/*
283 * Host AP crypt: host-based CCMP encryption implementation for Host AP driver
284 *
285 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi>
286 *
287 * This program is free software; you can redistribute it and/or modify
288 * it under the terms of the GNU General Public License version 2 as
289 * published by the Free Software Foundation. See README and COPYING for
290 * more details.
291 *
292 * Alternatively, this software may be distributed under the terms of BSD
293 * license.
294 */
295
296static void
297ccmp_init_blocks(rijndael_ctx *ctx, struct ieee80211_frame *wh,
298	u_int64_t pn, size_t dlen,
299	uint8_t b0[AES_BLOCK_LEN], uint8_t aad[2 * AES_BLOCK_LEN],
300	uint8_t auth[AES_BLOCK_LEN], uint8_t s0[AES_BLOCK_LEN])
301{
302#define	IS_QOS_DATA(wh)	IEEE80211_QOS_HAS_SEQ(wh)
303
304	/* CCM Initial Block:
305	 * Flag (Include authentication header, M=3 (8-octet MIC),
306	 *       L=1 (2-octet Dlen))
307	 * Nonce: 0x00 | A2 | PN
308	 * Dlen */
309	b0[0] = 0x59;
310	/* NB: b0[1] set below */
311	IEEE80211_ADDR_COPY(b0 + 2, wh->i_addr2);
312	b0[8] = pn >> 40;
313	b0[9] = pn >> 32;
314	b0[10] = pn >> 24;
315	b0[11] = pn >> 16;
316	b0[12] = pn >> 8;
317	b0[13] = pn >> 0;
318	b0[14] = (dlen >> 8) & 0xff;
319	b0[15] = dlen & 0xff;
320
321	/* AAD:
322	 * FC with bits 4..6 and 11..13 masked to zero; 14 is always one
323	 * A1 | A2 | A3
324	 * SC with bits 4..15 (seq#) masked to zero
325	 * A4 (if present)
326	 * QC (if present)
327	 */
328	aad[0] = 0;	/* AAD length >> 8 */
329	/* NB: aad[1] set below */
330	aad[2] = wh->i_fc[0] & 0x8f;	/* XXX magic #s */
331	aad[3] = wh->i_fc[1] & 0xc7;	/* XXX magic #s */
332	/* NB: we know 3 addresses are contiguous */
333	memcpy(aad + 4, wh->i_addr1, 3 * IEEE80211_ADDR_LEN);
334	aad[22] = wh->i_seq[0] & IEEE80211_SEQ_FRAG_MASK;
335	aad[23] = 0; /* all bits masked */
336	/*
337	 * Construct variable-length portion of AAD based
338	 * on whether this is a 4-address frame/QOS frame.
339	 * We always zero-pad to 32 bytes before running it
340	 * through the cipher.
341	 *
342	 * We also fill in the priority bits of the CCM
343	 * initial block as we know whether or not we have
344	 * a QOS frame.
345	 */
346	if (IEEE80211_IS_DSTODS(wh)) {
347		IEEE80211_ADDR_COPY(aad + 24,
348			((struct ieee80211_frame_addr4 *)wh)->i_addr4);
349		if (IS_QOS_DATA(wh)) {
350			struct ieee80211_qosframe_addr4 *qwh4 =
351				(struct ieee80211_qosframe_addr4 *) wh;
352			aad[30] = qwh4->i_qos[0] & 0x0f;/* just priority bits */
353			aad[31] = 0;
354			b0[1] = aad[30];
355			aad[1] = 22 + IEEE80211_ADDR_LEN + 2;
356		} else {
357			*(uint16_t *)&aad[30] = 0;
358			b0[1] = 0;
359			aad[1] = 22 + IEEE80211_ADDR_LEN;
360		}
361	} else {
362		if (IS_QOS_DATA(wh)) {
363			struct ieee80211_qosframe *qwh =
364				(struct ieee80211_qosframe*) wh;
365			aad[24] = qwh->i_qos[0] & 0x0f;	/* just priority bits */
366			aad[25] = 0;
367			b0[1] = aad[24];
368			aad[1] = 22 + 2;
369		} else {
370			*(uint16_t *)&aad[24] = 0;
371			b0[1] = 0;
372			aad[1] = 22;
373		}
374		*(uint16_t *)&aad[26] = 0;
375		*(uint32_t *)&aad[28] = 0;
376	}
377
378	/* Start with the first block and AAD */
379	rijndael_encrypt(ctx, b0, auth);
380	xor_block(auth, aad, AES_BLOCK_LEN);
381	rijndael_encrypt(ctx, auth, auth);
382	xor_block(auth, &aad[AES_BLOCK_LEN], AES_BLOCK_LEN);
383	rijndael_encrypt(ctx, auth, auth);
384	b0[0] &= 0x07;
385	b0[14] = b0[15] = 0;
386	rijndael_encrypt(ctx, b0, s0);
387#undef	IS_QOS_DATA
388}
389
390#define	CCMP_ENCRYPT(_i, _b, _b0, _pos, _e, _len) do {	\
391	/* Authentication */				\
392	xor_block(_b, _pos, _len);			\
393	rijndael_encrypt(&ctx->cc_aes, _b, _b);		\
394	/* Encryption, with counter */			\
395	_b0[14] = (_i >> 8) & 0xff;			\
396	_b0[15] = _i & 0xff;				\
397	rijndael_encrypt(&ctx->cc_aes, _b0, _e);	\
398	xor_block(_pos, _e, _len);			\
399} while (0)
400
401static int
402ccmp_encrypt(struct ieee80211_key *key, struct mbuf *m0, int hdrlen)
403{
404	struct ccmp_ctx *ctx = key->wk_private;
405	struct ieee80211_frame *wh;
406	struct mbuf *m = m0;
407	int data_len, i, space;
408	uint8_t aad[2 * AES_BLOCK_LEN], b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN],
409		e[AES_BLOCK_LEN], s0[AES_BLOCK_LEN];
410	uint8_t *pos;
411
412	ctx->cc_vap->iv_stats.is_crypto_ccmp++;
413
414	wh = mtod(m, struct ieee80211_frame *);
415	data_len = m->m_pkthdr.len - (hdrlen + ccmp.ic_header);
416	ccmp_init_blocks(&ctx->cc_aes, wh, key->wk_keytsc,
417		data_len, b0, aad, b, s0);
418
419	i = 1;
420	pos = mtod(m, uint8_t *) + hdrlen + ccmp.ic_header;
421	/* NB: assumes header is entirely in first mbuf */
422	space = m->m_len - (hdrlen + ccmp.ic_header);
423	for (;;) {
424		if (space > data_len)
425			space = data_len;
426		/*
427		 * Do full blocks.
428		 */
429		while (space >= AES_BLOCK_LEN) {
430			CCMP_ENCRYPT(i, b, b0, pos, e, AES_BLOCK_LEN);
431			pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN;
432			data_len -= AES_BLOCK_LEN;
433			i++;
434		}
435		if (data_len <= 0)		/* no more data */
436			break;
437		m = m->m_next;
438		if (m == NULL) {		/* last buffer */
439			if (space != 0) {
440				/*
441				 * Short last block.
442				 */
443				CCMP_ENCRYPT(i, b, b0, pos, e, space);
444			}
445			break;
446		}
447		if (space != 0) {
448			uint8_t *pos_next;
449			int space_next;
450			int len, dl, sp;
451			struct mbuf *n;
452
453			/*
454			 * Block straddles one or more mbufs, gather data
455			 * into the block buffer b, apply the cipher, then
456			 * scatter the results back into the mbuf chain.
457			 * The buffer will automatically get space bytes
458			 * of data at offset 0 copied in+out by the
459			 * CCMP_ENCRYPT request so we must take care of
460			 * the remaining data.
461			 */
462			n = m;
463			dl = data_len;
464			sp = space;
465			for (;;) {
466				pos_next = mtod(n, uint8_t *);
467				len = min(dl, AES_BLOCK_LEN);
468				space_next = len > sp ? len - sp : 0;
469				if (n->m_len >= space_next) {
470					/*
471					 * This mbuf has enough data; just grab
472					 * what we need and stop.
473					 */
474					xor_block(b+sp, pos_next, space_next);
475					break;
476				}
477				/*
478				 * This mbuf's contents are insufficient,
479				 * take 'em all and prepare to advance to
480				 * the next mbuf.
481				 */
482				xor_block(b+sp, pos_next, n->m_len);
483				sp += n->m_len, dl -= n->m_len;
484				n = n->m_next;
485				if (n == NULL)
486					break;
487			}
488
489			CCMP_ENCRYPT(i, b, b0, pos, e, space);
490
491			/* NB: just like above, but scatter data to mbufs */
492			dl = data_len;
493			sp = space;
494			for (;;) {
495				pos_next = mtod(m, uint8_t *);
496				len = min(dl, AES_BLOCK_LEN);
497				space_next = len > sp ? len - sp : 0;
498				if (m->m_len >= space_next) {
499					xor_block(pos_next, e+sp, space_next);
500					break;
501				}
502				xor_block(pos_next, e+sp, m->m_len);
503				sp += m->m_len, dl -= m->m_len;
504				m = m->m_next;
505				if (m == NULL)
506					goto done;
507			}
508			/*
509			 * Do bookkeeping.  m now points to the last mbuf
510			 * we grabbed data from.  We know we consumed a
511			 * full block of data as otherwise we'd have hit
512			 * the end of the mbuf chain, so deduct from data_len.
513			 * Otherwise advance the block number (i) and setup
514			 * pos+space to reflect contents of the new mbuf.
515			 */
516			data_len -= AES_BLOCK_LEN;
517			i++;
518			pos = pos_next + space_next;
519			space = m->m_len - space_next;
520		} else {
521			/*
522			 * Setup for next buffer.
523			 */
524			pos = mtod(m, uint8_t *);
525			space = m->m_len;
526		}
527	}
528done:
529	/* tack on MIC */
530	xor_block(b, s0, ccmp.ic_trailer);
531	return m_append(m0, ccmp.ic_trailer, b);
532}
533#undef CCMP_ENCRYPT
534
535#define	CCMP_DECRYPT(_i, _b, _b0, _pos, _a, _len) do {	\
536	/* Decrypt, with counter */			\
537	_b0[14] = (_i >> 8) & 0xff;			\
538	_b0[15] = _i & 0xff;				\
539	rijndael_encrypt(&ctx->cc_aes, _b0, _b);	\
540	xor_block(_pos, _b, _len);			\
541	/* Authentication */				\
542	xor_block(_a, _pos, _len);			\
543	rijndael_encrypt(&ctx->cc_aes, _a, _a);		\
544} while (0)
545
546static int
547ccmp_decrypt(struct ieee80211_key *key, u_int64_t pn, struct mbuf *m, int hdrlen)
548{
549	struct ccmp_ctx *ctx = key->wk_private;
550	struct ieee80211vap *vap = ctx->cc_vap;
551	struct ieee80211_frame *wh;
552	uint8_t aad[2 * AES_BLOCK_LEN];
553	uint8_t b0[AES_BLOCK_LEN], b[AES_BLOCK_LEN], a[AES_BLOCK_LEN];
554	uint8_t mic[AES_BLOCK_LEN];
555	size_t data_len;
556	int i;
557	uint8_t *pos;
558	u_int space;
559
560	ctx->cc_vap->iv_stats.is_crypto_ccmp++;
561
562	wh = mtod(m, struct ieee80211_frame *);
563	data_len = m->m_pkthdr.len - (hdrlen + ccmp.ic_header + ccmp.ic_trailer);
564	ccmp_init_blocks(&ctx->cc_aes, wh, pn, data_len, b0, aad, a, b);
565	m_copydata(m, m->m_pkthdr.len - ccmp.ic_trailer, ccmp.ic_trailer, mic);
566	xor_block(mic, b, ccmp.ic_trailer);
567
568	i = 1;
569	pos = mtod(m, uint8_t *) + hdrlen + ccmp.ic_header;
570	space = m->m_len - (hdrlen + ccmp.ic_header);
571	for (;;) {
572		if (space > data_len)
573			space = data_len;
574		while (space >= AES_BLOCK_LEN) {
575			CCMP_DECRYPT(i, b, b0, pos, a, AES_BLOCK_LEN);
576			pos += AES_BLOCK_LEN, space -= AES_BLOCK_LEN;
577			data_len -= AES_BLOCK_LEN;
578			i++;
579		}
580		if (data_len <= 0)		/* no more data */
581			break;
582		m = m->m_next;
583		if (m == NULL) {		/* last buffer */
584			if (space != 0)		/* short last block */
585				CCMP_DECRYPT(i, b, b0, pos, a, space);
586			break;
587		}
588		if (space != 0) {
589			uint8_t *pos_next;
590			u_int space_next;
591			u_int len;
592
593			/*
594			 * Block straddles buffers, split references.  We
595			 * do not handle splits that require >2 buffers
596			 * since rx'd frames are never badly fragmented
597			 * because drivers typically recv in clusters.
598			 */
599			pos_next = mtod(m, uint8_t *);
600			len = min(data_len, AES_BLOCK_LEN);
601			space_next = len > space ? len - space : 0;
602			KASSERT(m->m_len >= space_next,
603				("not enough data in following buffer, "
604				"m_len %u need %u\n", m->m_len, space_next));
605
606			xor_block(b+space, pos_next, space_next);
607			CCMP_DECRYPT(i, b, b0, pos, a, space);
608			xor_block(pos_next, b+space, space_next);
609			data_len -= len;
610			i++;
611
612			pos = pos_next + space_next;
613			space = m->m_len - space_next;
614		} else {
615			/*
616			 * Setup for next buffer.
617			 */
618			pos = mtod(m, uint8_t *);
619			space = m->m_len;
620		}
621	}
622	if (memcmp(mic, a, ccmp.ic_trailer) != 0) {
623		IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO, wh->i_addr2,
624		    "%s", "AES-CCM decrypt failed; MIC mismatch");
625		vap->iv_stats.is_rx_ccmpmic++;
626		return 0;
627	}
628	return 1;
629}
630#undef CCMP_DECRYPT
631
632/*
633 * Module glue.
634 */
635IEEE80211_CRYPTO_MODULE(ccmp, 1);
636