1/*	$NetBSD: ieee80211_crypto_tkip.c,v 1.18 2023/06/24 05:12:03 msaitoh Exp $	*/
2
3/*
4 * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 *    derived from this software without specific prior written permission.
17 *
18 * Alternatively, this software may be distributed under the terms of the
19 * GNU General Public License ("GPL") version 2 as published by the Free
20 * Software Foundation.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34#include <sys/cdefs.h>
35#ifdef __FreeBSD__
36__FBSDID("$FreeBSD: src/sys/net80211/ieee80211_crypto_tkip.c,v 1.10 2005/08/08 18:46:35 sam Exp $");
37#endif
38#ifdef __NetBSD__
39__KERNEL_RCSID(0, "$NetBSD: ieee80211_crypto_tkip.c,v 1.18 2023/06/24 05:12:03 msaitoh Exp $");
40#endif
41
42/*
43 * IEEE 802.11i TKIP crypto support.
44 *
45 * Part of this module is derived from similar code in the Host
46 * AP driver. The code is used with the consent of the author and
47 * its license is included below.
48 */
49#include <sys/param.h>
50#include <sys/systm.h>
51#include <sys/mbuf.h>
52#include <sys/kmem.h>
53#include <sys/kernel.h>
54#include <sys/endian.h>
55
56#include <sys/socket.h>
57
58#include <net/if.h>
59#include <net/if_ether.h>
60#include <net/if_media.h>
61
62#include <net80211/ieee80211_var.h>
63
64static	void *tkip_attach(struct ieee80211com *, struct ieee80211_key *);
65static	void tkip_detach(struct ieee80211_key *);
66static	int tkip_setkey(struct ieee80211_key *);
67static	int tkip_encap(struct ieee80211_key *, struct mbuf *m, u_int8_t keyid);
68static	int tkip_enmic(struct ieee80211_key *, struct mbuf *, int);
69static	int tkip_decap(struct ieee80211_key *, struct mbuf *, int);
70static	int tkip_demic(struct ieee80211_key *, struct mbuf *, int);
71
72const struct ieee80211_cipher ieee80211_cipher_tkip  = {
73	.ic_name	= "TKIP",
74	.ic_cipher	= IEEE80211_CIPHER_TKIP,
75	.ic_header	= IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN +
76			  IEEE80211_WEP_EXTIVLEN,
77	.ic_trailer	= IEEE80211_WEP_CRCLEN,
78	.ic_miclen	= IEEE80211_WEP_MICLEN,
79	.ic_attach	= tkip_attach,
80	.ic_detach	= tkip_detach,
81	.ic_setkey	= tkip_setkey,
82	.ic_encap	= tkip_encap,
83	.ic_decap	= tkip_decap,
84	.ic_enmic	= tkip_enmic,
85	.ic_demic	= tkip_demic,
86};
87
88#define	tkip	ieee80211_cipher_tkip
89
90typedef	uint8_t u8;
91typedef	uint16_t u16;
92typedef	uint32_t __u32;
93typedef	uint32_t u32;
94
95struct tkip_ctx {
96	struct ieee80211com *tc_ic;	/* for diagnostics */
97
98	u16	tx_ttak[5];
99	int	tx_phase1_done;
100	u8	tx_rc4key[16];		/* XXX for test module; make locals? */
101
102	u16	rx_ttak[5];
103	int	rx_phase1_done;
104	u8	rx_rc4key[16];		/* XXX for test module; make locals? */
105	uint64_t rx_rsc;		/* held until MIC verified */
106};
107
108static	void michael_mic(struct tkip_ctx *, const u8 *key,
109		struct mbuf *m, u_int off, size_t data_len,
110		u8 mic[IEEE80211_WEP_MICLEN]);
111static	int tkip_encrypt(struct tkip_ctx *, struct ieee80211_key *,
112		struct mbuf *, int hdr_len);
113static	int tkip_decrypt(struct tkip_ctx *, struct ieee80211_key *,
114		struct mbuf *, int hdr_len);
115
116static void *
117tkip_attach(struct ieee80211com *ic, struct ieee80211_key *k)
118{
119	struct tkip_ctx *ctx;
120
121	ctx = kmem_intr_zalloc(sizeof(struct tkip_ctx), KM_NOSLEEP);
122	if (ctx == NULL) {
123		ic->ic_stats.is_crypto_nomem++;
124		return NULL;
125	}
126
127	ctx->tc_ic = ic;
128	return ctx;
129}
130
131static void
132tkip_detach(struct ieee80211_key *k)
133{
134	struct tkip_ctx *ctx = k->wk_private;
135
136	kmem_intr_free(ctx, sizeof(struct tkip_ctx));
137}
138
139static int
140tkip_setkey(struct ieee80211_key *k)
141{
142	struct tkip_ctx *ctx = k->wk_private;
143
144	if (k->wk_keylen != (128/NBBY)) {
145		(void) ctx;		/* XXX */
146		IEEE80211_DPRINTF(ctx->tc_ic, IEEE80211_MSG_CRYPTO,
147			"%s: Invalid key length %u, expecting %u\n",
148			__func__, k->wk_keylen, 128/NBBY);
149		return 0;
150	}
151	k->wk_keytsc = 1;		/* TSC starts at 1 */
152	return 1;
153}
154
155/*
156 * Add privacy headers and do any s/w encryption required.
157 */
158static int
159tkip_encap(struct ieee80211_key *k, struct mbuf *m, u_int8_t keyid)
160{
161	struct tkip_ctx *ctx = k->wk_private;
162	struct ieee80211com *ic = ctx->tc_ic;
163	u_int8_t *ivp;
164	int hdrlen;
165
166	/*
167	 * Handle TKIP counter measures requirement.
168	 */
169	if (ic->ic_flags & IEEE80211_F_COUNTERM) {
170#ifdef IEEE80211_DEBUG
171		struct ieee80211_frame *wh = mtod(m, struct ieee80211_frame *);
172#endif
173
174		IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO,
175			"[%s] Discard frame due to countermeasures (%s)\n",
176			ether_sprintf(wh->i_addr2), __func__);
177		ic->ic_stats.is_crypto_tkipcm++;
178		return 0;
179	}
180
181	hdrlen = ieee80211_hdrspace(ic, mtod(m, void *));
182	ivp = mtod(m, u_int8_t *) + hdrlen;
183
184	ivp[0] = k->wk_keytsc >> 8;		/* TSC1 */
185	ivp[1] = (ivp[0] | 0x20) & 0x7f;	/* WEP seed */
186	ivp[2] = k->wk_keytsc >> 0;		/* TSC0 */
187	ivp[3] = keyid | IEEE80211_WEP_EXTIV;	/* KeyID | ExtID */
188	ivp[4] = k->wk_keytsc >> 16;		/* TSC2 */
189	ivp[5] = k->wk_keytsc >> 24;		/* TSC3 */
190	ivp[6] = k->wk_keytsc >> 32;		/* TSC4 */
191	ivp[7] = k->wk_keytsc >> 40;		/* TSC5 */
192
193	/*
194	 * Finally, do software encrypt if need.
195	 */
196	if (k->wk_flags & IEEE80211_KEY_SWCRYPT) {
197		if (!tkip_encrypt(ctx, k, m, hdrlen))
198			return 0;
199		/* NB: tkip_encrypt handles wk_keytsc */
200	} else
201		k->wk_keytsc++;
202
203	return 1;
204}
205
206/*
207 * Add MIC to the frame as needed.
208 */
209static int
210tkip_enmic(struct ieee80211_key *k, struct mbuf *m, int force)
211{
212	struct tkip_ctx *ctx = k->wk_private;
213
214	if (force || (k->wk_flags & IEEE80211_KEY_SWMIC)) {
215		struct ieee80211_frame *wh = mtod(m, struct ieee80211_frame *);
216		struct ieee80211com *ic = ctx->tc_ic;
217		int hdrlen;
218		uint8_t mic[IEEE80211_WEP_MICLEN];
219
220		ic->ic_stats.is_crypto_tkipenmic++;
221
222		hdrlen = ieee80211_hdrspace(ic, wh);
223
224		michael_mic(ctx, k->wk_txmic,
225			m, hdrlen, m->m_pkthdr.len - hdrlen, mic);
226		return m_append(m, tkip.ic_miclen, mic);
227	}
228	return 1;
229}
230
231static __inline uint64_t
232READ_6(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3, uint8_t b4, uint8_t b5)
233{
234	uint32_t iv32 = (b0 << 0) | (b1 << 8) | (b2 << 16) | ((u32)b3 << 24);
235	uint16_t iv16 = (b4 << 0) | (b5 << 8);
236	return (((uint64_t)iv16) << 32) | iv32;
237}
238
239/*
240 * Validate and strip privacy headers (and trailer) for a
241 * received frame.  If necessary, decrypt the frame using
242 * the specified key.
243 */
244static int
245tkip_decap(struct ieee80211_key *k, struct mbuf *m, int hdrlen)
246{
247	struct tkip_ctx *ctx = k->wk_private;
248	struct ieee80211com *ic = ctx->tc_ic;
249	struct ieee80211_frame *wh;
250	uint8_t *ivp;
251
252	/*
253	 * Header should have extended IV and sequence number;
254	 * verify the former and validate the latter.
255	 */
256	wh = mtod(m, struct ieee80211_frame *);
257	ivp = mtod(m, uint8_t *) + hdrlen;
258	if ((ivp[IEEE80211_WEP_IVLEN] & IEEE80211_WEP_EXTIV) == 0) {
259		/*
260		 * No extended IV; discard frame.
261		 */
262		IEEE80211_DPRINTF(ctx->tc_ic, IEEE80211_MSG_CRYPTO,
263			"[%s] missing ExtIV for TKIP cipher\n",
264			ether_sprintf(wh->i_addr2));
265		ctx->tc_ic->ic_stats.is_rx_tkipformat++;
266		return 0;
267	}
268	/*
269	 * Handle TKIP counter measures requirement.
270	 */
271	if (ic->ic_flags & IEEE80211_F_COUNTERM) {
272		IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO,
273			"[%s] discard frame due to countermeasures (%s)\n",
274			ether_sprintf(wh->i_addr2), __func__);
275		ic->ic_stats.is_crypto_tkipcm++;
276		return 0;
277	}
278
279	ctx->rx_rsc = READ_6(ivp[2], ivp[0], ivp[4], ivp[5], ivp[6], ivp[7]);
280	if (ctx->rx_rsc <= k->wk_keyrsc) {
281		/*
282		 * Replay violation; notify upper layer.
283		 */
284		ieee80211_notify_replay_failure(ctx->tc_ic, wh, k, ctx->rx_rsc);
285		ctx->tc_ic->ic_stats.is_rx_tkipreplay++;
286		return 0;
287	}
288	/*
289	 * NB: We can't update the rsc in the key until MIC is verified.
290	 *
291	 * We assume we are not preempted between doing the check above
292	 * and updating wk_keyrsc when stripping the MIC in tkip_demic.
293	 * Otherwise we might process another packet and discard it as
294	 * a replay.
295	 */
296
297	/*
298	 * Check if the device handled the decrypt in hardware.
299	 * If so we just strip the header; otherwise we need to
300	 * handle the decrypt in software.
301	 */
302	if ((k->wk_flags & IEEE80211_KEY_SWCRYPT) &&
303	    !tkip_decrypt(ctx, k, m, hdrlen))
304		return 0;
305
306	/*
307	 * Copy up 802.11 header and strip crypto bits.
308	 */
309	memmove(mtod(m, uint8_t *) + tkip.ic_header, mtod(m, void *), hdrlen);
310	m_adj(m, tkip.ic_header);
311	m_adj(m, -tkip.ic_trailer);
312
313	return 1;
314}
315
316/*
317 * Verify and strip MIC from the frame.
318 */
319static int
320tkip_demic(struct ieee80211_key *k, struct mbuf *m, int force)
321{
322	struct tkip_ctx *ctx = k->wk_private;
323
324	if (force || (k->wk_flags & IEEE80211_KEY_SWMIC)) {
325		struct ieee80211_frame *wh = mtod(m, struct ieee80211_frame *);
326		struct ieee80211com *ic = ctx->tc_ic;
327		int hdrlen = ieee80211_hdrspace(ic, wh);
328		u8 mic[IEEE80211_WEP_MICLEN];
329		u8 mic0[IEEE80211_WEP_MICLEN];
330
331		ic->ic_stats.is_crypto_tkipdemic++;
332
333		michael_mic(ctx, k->wk_rxmic,
334			m, hdrlen, m->m_pkthdr.len - (hdrlen + tkip.ic_miclen),
335			mic);
336		m_copydata(m, m->m_pkthdr.len - tkip.ic_miclen,
337			tkip.ic_miclen, mic0);
338		if (memcmp(mic, mic0, tkip.ic_miclen)) {
339			/* NB: 802.11 layer handles statistic and debug msg */
340			ieee80211_notify_michael_failure(ic, wh,
341				k->wk_rxkeyix != IEEE80211_KEYIX_NONE ?
342					k->wk_rxkeyix : k->wk_keyix);
343			return 0;
344		}
345	}
346	/*
347	 * Strip MIC from the tail.
348	 */
349	m_adj(m, -tkip.ic_miclen);
350
351	/*
352	 * Ok to update rsc now that MIC has been verified.
353	 */
354	k->wk_keyrsc = ctx->rx_rsc;
355
356	return 1;
357}
358
359/*
360 * Host AP crypt: host-based TKIP encryption implementation for Host AP driver
361 *
362 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi>
363 *
364 * This program is free software; you can redistribute it and/or modify
365 * it under the terms of the GNU General Public License version 2 as
366 * published by the Free Software Foundation. See README and COPYING for
367 * more details.
368 *
369 * Alternatively, this software may be distributed under the terms of BSD
370 * license.
371 */
372
373static const __u32 crc32_table[256] = {
374	0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
375	0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
376	0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
377	0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
378	0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
379	0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
380	0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
381	0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
382	0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
383	0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
384	0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
385	0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
386	0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
387	0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
388	0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
389	0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
390	0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
391	0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
392	0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
393	0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
394	0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
395	0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
396	0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
397	0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
398	0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
399	0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
400	0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
401	0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
402	0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
403	0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
404	0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
405	0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
406	0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
407	0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
408	0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
409	0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
410	0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
411	0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
412	0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
413	0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
414	0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
415	0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
416	0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
417	0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
418	0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
419	0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
420	0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
421	0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
422	0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
423	0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
424	0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
425	0x2d02ef8dL
426};
427
428static __inline u16 RotR1(u16 val)
429{
430	return (val >> 1) | (val << 15);
431}
432
433static __inline u8 Lo8(u16 val)
434{
435	return val & 0xff;
436}
437
438static __inline u8 Hi8(u16 val)
439{
440	return val >> 8;
441}
442
443static __inline u16 Lo16(u32 val)
444{
445	return val & 0xffff;
446}
447
448static __inline u16 Hi16(u32 val)
449{
450	return val >> 16;
451}
452
453static __inline u16 Mk16(u8 hi, u8 lo)
454{
455	return lo | (((u16) hi) << 8);
456}
457
458static __inline u16 Mk16_le(const u16 *v)
459{
460	return le16toh(*v);
461}
462
463static const u16 Sbox[256] = {
464	0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154,
465	0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A,
466	0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B,
467	0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B,
468	0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F,
469	0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F,
470	0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5,
471	0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F,
472	0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB,
473	0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397,
474	0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED,
475	0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A,
476	0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194,
477	0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3,
478	0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104,
479	0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D,
480	0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39,
481	0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695,
482	0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83,
483	0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76,
484	0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4,
485	0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B,
486	0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0,
487	0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018,
488	0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751,
489	0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85,
490	0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12,
491	0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9,
492	0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7,
493	0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A,
494	0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8,
495	0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A,
496};
497
498static __inline u16 _S_(u16 v)
499{
500	u16 t = Sbox[Hi8(v)];
501	return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8));
502}
503
504#define PHASE1_LOOP_COUNT 8
505
506static void tkip_mixing_phase1(u16 *TTAK, const u8 *TK, const u8 *TA, u32 IV32)
507{
508	int i, j;
509
510	/* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */
511	TTAK[0] = Lo16(IV32);
512	TTAK[1] = Hi16(IV32);
513	TTAK[2] = Mk16(TA[1], TA[0]);
514	TTAK[3] = Mk16(TA[3], TA[2]);
515	TTAK[4] = Mk16(TA[5], TA[4]);
516
517	for (i = 0; i < PHASE1_LOOP_COUNT; i++) {
518		j = 2 * (i & 1);
519		TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j]));
520		TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j]));
521		TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j]));
522		TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j]));
523		TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i;
524	}
525}
526
527#ifndef _BYTE_ORDER
528#error "Don't know native byte order"
529#endif
530
531static void tkip_mixing_phase2(u8 *WEPSeed, const u8 *TK, const u16 *TTAK,
532			       u16 IV16)
533{
534	/* Make temporary area overlap WEP seed so that the final copy can be
535	 * avoided on little endian hosts. */
536	u16 *PPK = (u16 *) &WEPSeed[4];
537
538	/* Step 1 - make copy of TTAK and bring in TSC */
539	PPK[0] = TTAK[0];
540	PPK[1] = TTAK[1];
541	PPK[2] = TTAK[2];
542	PPK[3] = TTAK[3];
543	PPK[4] = TTAK[4];
544	PPK[5] = TTAK[4] + IV16;
545
546	/* Step 2 - 96-bit bijective mixing using S-box */
547	PPK[0] += _S_(PPK[5] ^ Mk16_le((const u16 *) &TK[0]));
548	PPK[1] += _S_(PPK[0] ^ Mk16_le((const u16 *) &TK[2]));
549	PPK[2] += _S_(PPK[1] ^ Mk16_le((const u16 *) &TK[4]));
550	PPK[3] += _S_(PPK[2] ^ Mk16_le((const u16 *) &TK[6]));
551	PPK[4] += _S_(PPK[3] ^ Mk16_le((const u16 *) &TK[8]));
552	PPK[5] += _S_(PPK[4] ^ Mk16_le((const u16 *) &TK[10]));
553
554	PPK[0] += RotR1(PPK[5] ^ Mk16_le((const u16 *) &TK[12]));
555	PPK[1] += RotR1(PPK[0] ^ Mk16_le((const u16 *) &TK[14]));
556	PPK[2] += RotR1(PPK[1]);
557	PPK[3] += RotR1(PPK[2]);
558	PPK[4] += RotR1(PPK[3]);
559	PPK[5] += RotR1(PPK[4]);
560
561	/* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value
562	 * WEPSeed[0..2] is transmitted as WEP IV */
563	WEPSeed[0] = Hi8(IV16);
564	WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F;
565	WEPSeed[2] = Lo8(IV16);
566	WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((const u16 *) &TK[0])) >> 1);
567
568#if _BYTE_ORDER == _BIG_ENDIAN
569	{
570		int i;
571		for (i = 0; i < 6; i++)
572			PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8);
573	}
574#endif
575}
576
577static void
578wep_encrypt(u8 *key, struct mbuf *m0, u_int off, size_t data_len,
579	uint8_t icv[IEEE80211_WEP_CRCLEN])
580{
581	u32 i, j, k, crc;
582	size_t buflen;
583	u8 S[256];
584	u8 *pos;
585	struct mbuf *m;
586#define S_SWAP(a,b) do { u8 t = S[a]; S[a] = S[b]; S[b] = t; } while(0)
587
588	/* Setup RC4 state */
589	for (i = 0; i < 256; i++)
590		S[i] = i;
591	j = 0;
592	for (i = 0; i < 256; i++) {
593		j = (j + S[i] + key[i & 0x0f]) & 0xff;
594		S_SWAP(i, j);
595	}
596
597	/* Compute CRC32 over unencrypted data and apply RC4 to data */
598	crc = ~0;
599	i = j = 0;
600	m = m0;
601	pos = mtod(m, uint8_t *) + off;
602	buflen = m->m_len - off;
603	for (;;) {
604		if (buflen > data_len)
605			buflen = data_len;
606		data_len -= buflen;
607		for (k = 0; k < buflen; k++) {
608			crc = crc32_table[(crc ^ *pos) & 0xff] ^ (crc >> 8);
609			i = (i + 1) & 0xff;
610			j = (j + S[i]) & 0xff;
611			S_SWAP(i, j);
612			*pos++ ^= S[(S[i] + S[j]) & 0xff];
613		}
614		m = m->m_next;
615		if (m == NULL) {
616			IASSERT(data_len == 0,
617			    ("out of buffers with data_len %zu\n", data_len));
618			break;
619		}
620		pos = mtod(m, uint8_t *);
621		buflen = m->m_len;
622	}
623	crc = ~crc;
624
625	/* Append little-endian CRC32 and encrypt it to produce ICV */
626	icv[0] = crc;
627	icv[1] = crc >> 8;
628	icv[2] = crc >> 16;
629	icv[3] = crc >> 24;
630	for (k = 0; k < IEEE80211_WEP_CRCLEN; k++) {
631		i = (i + 1) & 0xff;
632		j = (j + S[i]) & 0xff;
633		S_SWAP(i, j);
634		icv[k] ^= S[(S[i] + S[j]) & 0xff];
635	}
636}
637
638static int
639wep_decrypt(u8 *key, struct mbuf *m, u_int off, size_t data_len)
640{
641	u32 i, j, k, crc;
642	u8 S[256];
643	u8 *pos, icv[4];
644	size_t buflen;
645
646	/* Setup RC4 state */
647	for (i = 0; i < 256; i++)
648		S[i] = i;
649	j = 0;
650	for (i = 0; i < 256; i++) {
651		j = (j + S[i] + key[i & 0x0f]) & 0xff;
652		S_SWAP(i, j);
653	}
654
655	/* Apply RC4 to data and compute CRC32 over decrypted data */
656	crc = ~0;
657	i = j = 0;
658	pos = mtod(m, uint8_t *) + off;
659	buflen = m->m_len - off;
660	for (;;) {
661		if (buflen > data_len)
662			buflen = data_len;
663		data_len -= buflen;
664		for (k = 0; k < buflen; k++) {
665			i = (i + 1) & 0xff;
666			j = (j + S[i]) & 0xff;
667			S_SWAP(i, j);
668			*pos ^= S[(S[i] + S[j]) & 0xff];
669			crc = crc32_table[(crc ^ *pos) & 0xff] ^ (crc >> 8);
670			pos++;
671		}
672		m = m->m_next;
673		if (m == NULL) {
674			IASSERT(data_len == 0,
675			    ("out of buffers with data_len %zu\n", data_len));
676			break;
677		}
678		pos = mtod(m, uint8_t *);
679		buflen = m->m_len;
680	}
681	crc = ~crc;
682
683	/* Encrypt little-endian CRC32 and verify that it matches with the
684	 * received ICV */
685	icv[0] = crc;
686	icv[1] = crc >> 8;
687	icv[2] = crc >> 16;
688	icv[3] = crc >> 24;
689	for (k = 0; k < 4; k++) {
690		i = (i + 1) & 0xff;
691		j = (j + S[i]) & 0xff;
692		S_SWAP(i, j);
693		if ((icv[k] ^ S[(S[i] + S[j]) & 0xff]) != *pos++) {
694			/* ICV mismatch - drop frame */
695			return -1;
696		}
697	}
698
699	return 0;
700}
701
702
703static __inline u32 rotl(u32 val, int bits)
704{
705	return (val << bits) | (val >> (32 - bits));
706}
707
708
709static __inline u32 rotr(u32 val, int bits)
710{
711	return (val >> bits) | (val << (32 - bits));
712}
713
714
715static __inline u32 xswap(u32 val)
716{
717	return ((val & 0x00ff00ff) << 8) | ((val & 0xff00ff00) >> 8);
718}
719
720
721#define michael_block(l, r)	\
722do {				\
723	r ^= rotl(l, 17);	\
724	l += r;			\
725	r ^= xswap(l);		\
726	l += r;			\
727	r ^= rotl(l, 3);	\
728	l += r;			\
729	r ^= rotr(l, 2);	\
730	l += r;			\
731} while (0)
732
733
734static __inline u32 get_le32_split(u8 b0, u8 b1, u8 b2, u8 b3)
735{
736	return b0 | (b1 << 8) | (b2 << 16) | ((u32)b3 << 24);
737}
738
739static __inline u32 get_le32(const u8 *p)
740{
741	return get_le32_split(p[0], p[1], p[2], p[3]);
742}
743
744
745static __inline void put_le32(u8 *p, u32 v)
746{
747	p[0] = v;
748	p[1] = v >> 8;
749	p[2] = v >> 16;
750	p[3] = v >> 24;
751}
752
753/*
754 * Craft pseudo header used to calculate the MIC.
755 */
756static void
757michael_mic_hdr(const struct ieee80211_frame *wh0, uint8_t hdr[16])
758{
759	const struct ieee80211_frame_addr4 *wh =
760		(const struct ieee80211_frame_addr4 *) wh0;
761
762	switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) {
763	case IEEE80211_FC1_DIR_NODS:
764		IEEE80211_ADDR_COPY(hdr, wh->i_addr1); /* DA */
765		IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr2);
766		break;
767	case IEEE80211_FC1_DIR_TODS:
768		IEEE80211_ADDR_COPY(hdr, wh->i_addr3); /* DA */
769		IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr2);
770		break;
771	case IEEE80211_FC1_DIR_FROMDS:
772		IEEE80211_ADDR_COPY(hdr, wh->i_addr1); /* DA */
773		IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr3);
774		break;
775	case IEEE80211_FC1_DIR_DSTODS:
776		IEEE80211_ADDR_COPY(hdr, wh->i_addr3); /* DA */
777		IEEE80211_ADDR_COPY(hdr + IEEE80211_ADDR_LEN, wh->i_addr4);
778		break;
779	}
780
781	if (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_QOS) {
782		const struct ieee80211_qosframe *qwh =
783			(const struct ieee80211_qosframe *) wh;
784		hdr[12] = qwh->i_qos[0] & IEEE80211_QOS_TID;
785	} else
786		hdr[12] = 0;
787	hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */
788}
789
790static void
791michael_mic(struct tkip_ctx *ctx, const u8 *key,
792	struct mbuf *m, u_int off, size_t data_len,
793	u8 mic[IEEE80211_WEP_MICLEN])
794{
795	uint8_t hdr[16];
796	u32 l, r;
797	const uint8_t *data;
798	u_int space;
799	uint8_t spill[4];
800	int nspill = 0;
801
802	michael_mic_hdr(mtod(m, struct ieee80211_frame *), hdr);
803
804	l = get_le32(key);
805	r = get_le32(key + 4);
806
807	/* Michael MIC pseudo header: DA, SA, 3 x 0, Priority */
808	l ^= get_le32(hdr);
809	michael_block(l, r);
810	l ^= get_le32(&hdr[4]);
811	michael_block(l, r);
812	l ^= get_le32(&hdr[8]);
813	michael_block(l, r);
814	l ^= get_le32(&hdr[12]);
815	michael_block(l, r);
816
817	/* first buffer has special handling */
818	data = mtod(m, const uint8_t *) + off;
819	space = m->m_len - off;
820	for (;;) {
821		if (space > data_len)
822			space = data_len;
823		if (nspill) {
824			int n = uimin(4 - nspill, space);
825			memcpy(spill + nspill, data, n);
826			nspill += n;
827			data += n;
828			space -= n;
829			data_len -= n;
830			if (nspill == 4) {
831				l ^= get_le32(spill);
832				michael_block(l, r);
833				nspill = 0;
834			} else
835				goto next;
836		}
837		/* collect 32-bit blocks from current buffer */
838		while (space >= sizeof(uint32_t)) {
839			l ^= get_le32(data);
840			michael_block(l, r);
841			data += sizeof(uint32_t);
842			space -= sizeof(uint32_t);
843			data_len -= sizeof(uint32_t);
844		}
845		if (space) {
846			memcpy(spill, data, space);
847			nspill = space;
848			data_len -= space;
849		}
850next:
851		if (!data_len)
852			break;
853		m = m->m_next;
854		KASSERT(m);
855		/*
856		 * Setup for next buffer.
857		 */
858		data = mtod(m, const uint8_t *);
859		space = m->m_len;
860	}
861	/* Last block and padding (0x5a, 4..7 x 0) */
862	spill[nspill++] = 0x5a;
863	for (; nspill < 4; nspill++)
864		spill[nspill] = 0;
865	l ^= get_le32(spill);
866	michael_block(l, r);
867	/* l ^= 0; */
868	michael_block(l, r);
869
870	put_le32(mic, l);
871	put_le32(mic + 4, r);
872}
873
874static int
875tkip_encrypt(struct tkip_ctx *ctx, struct ieee80211_key *key,
876	struct mbuf *m, int hdrlen)
877{
878	struct ieee80211_frame *wh;
879	uint8_t icv[IEEE80211_WEP_CRCLEN];
880
881	ctx->tc_ic->ic_stats.is_crypto_tkip++;
882
883	wh = mtod(m, struct ieee80211_frame *);
884	if (!ctx->tx_phase1_done) {
885		tkip_mixing_phase1(ctx->tx_ttak, key->wk_key, wh->i_addr2,
886				   (u32)(key->wk_keytsc >> 16));
887		ctx->tx_phase1_done = 1;
888	}
889	tkip_mixing_phase2(ctx->tx_rc4key, key->wk_key, ctx->tx_ttak,
890		(u16)key->wk_keytsc);
891
892	wep_encrypt(ctx->tx_rc4key,
893		m, hdrlen + tkip.ic_header,
894		m->m_pkthdr.len - (hdrlen + tkip.ic_header),
895		icv);
896
897	if (!m_append(m, IEEE80211_WEP_CRCLEN, icv)) {
898		return 0;
899	}
900
901	key->wk_keytsc++;
902	if ((u16)(key->wk_keytsc) == 0)
903		ctx->tx_phase1_done = 0;
904
905	return 1;
906}
907
908static int
909tkip_decrypt(struct tkip_ctx *ctx, struct ieee80211_key *key,
910	struct mbuf *m, int hdrlen)
911{
912	struct ieee80211_frame *wh;
913	u32 iv32;
914	u16 iv16;
915
916	ctx->tc_ic->ic_stats.is_crypto_tkip++;
917
918	wh = mtod(m, struct ieee80211_frame *);
919	/* NB: tkip_decap already verified header and left seq in rx_rsc */
920	iv16 = (u16) ctx->rx_rsc;
921	iv32 = (u32) (ctx->rx_rsc >> 16);
922
923	if (iv32 != (u32)(key->wk_keyrsc >> 16) || !ctx->rx_phase1_done) {
924		tkip_mixing_phase1(ctx->rx_ttak, key->wk_key,
925			wh->i_addr2, iv32);
926		ctx->rx_phase1_done = 1;
927	}
928	tkip_mixing_phase2(ctx->rx_rc4key, key->wk_key, ctx->rx_ttak, iv16);
929
930	/* NB: m is unstripped; deduct headers + ICV to get payload */
931	if (wep_decrypt(ctx->rx_rc4key, m, hdrlen + tkip.ic_header,
932	    m->m_pkthdr.len - (hdrlen + tkip.ic_header + tkip.ic_trailer))) {
933		if (iv32 != (u32)(key->wk_keyrsc >> 16)) {
934			/* Previously cached Phase1 result was already lost, so
935			 * it needs to be recalculated for the next packet. */
936			ctx->rx_phase1_done = 0;
937		}
938		IEEE80211_DPRINTF(ctx->tc_ic, IEEE80211_MSG_CRYPTO,
939		    "[%s] TKIP ICV mismatch on decrypt\n",
940		    ether_sprintf(wh->i_addr2));
941		ctx->tc_ic->ic_stats.is_rx_tkipicv++;
942		return 0;
943	}
944
945	return 1;
946}
947
948IEEE80211_CRYPTO_SETUP(tkip_register)
949{
950	ieee80211_crypto_register(&tkip);
951}
952