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[net-next-2.6.git] / net / ieee80211 / ieee80211_crypt_tkip.c
CommitLineData
b453872c
JG		 1/*
2 * Host AP crypt: host-based TKIP encryption implementation for Host AP driver
3 *
4 * Copyright (c) 2003-2004, Jouni Malinen <jkmaline@cc.hut.fi>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation. See README and COPYING for
9 * more details.
10 */
11
f12cc209 12#include <linux/err.h>
b453872c
JG		 13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/slab.h>
16#include <linux/random.h>
17#include <linux/skbuff.h>
18#include <linux/netdevice.h>
d7fe0f24 19#include <linux/mm.h>
b453872c
JG		 20#include <linux/if_ether.h>
21#include <linux/if_arp.h>
22#include <asm/string.h>
23
24#include <net/ieee80211.h>
25
b453872c
JG		 26#include <linux/crypto.h>
27#include <asm/scatterlist.h>
28#include <linux/crc32.h>
29
30MODULE_AUTHOR("Jouni Malinen");
31MODULE_DESCRIPTION("Host AP crypt: TKIP");
32MODULE_LICENSE("GPL");
33
34struct ieee80211_tkip_data {
35#define TKIP_KEY_LEN 32
36 u8 key[TKIP_KEY_LEN];
37 int key_set;
38
39 u32 tx_iv32;
40 u16 tx_iv16;
41 u16 tx_ttak[5];
42 int tx_phase1_done;
43
44 u32 rx_iv32;
45 u16 rx_iv16;
46 u16 rx_ttak[5];
47 int rx_phase1_done;
48 u32 rx_iv32_new;
49 u16 rx_iv16_new;
50
51 u32 dot11RSNAStatsTKIPReplays;
52 u32 dot11RSNAStatsTKIPICVErrors;
53 u32 dot11RSNAStatsTKIPLocalMICFailures;
54
55 int key_idx;
56
28eb177d
JG		 57 struct crypto_blkcipher *rx_tfm_arc4;
58 struct crypto_hash *rx_tfm_michael;
59 struct crypto_blkcipher *tx_tfm_arc4;
60 struct crypto_hash *tx_tfm_michael;
b453872c
JG		 61
62 /* scratch buffers for virt_to_page() (crypto API) */
63 u8 rx_hdr[16], tx_hdr[16];
20d64713 64
6eb6edf0 65 unsigned long flags;
b453872c
JG		 66};
67
6eb6edf0
JK		 68static unsigned long ieee80211_tkip_set_flags(unsigned long flags, void *priv)
69{
70 struct ieee80211_tkip_data *_priv = priv;
71 unsigned long old_flags = _priv->flags;
72 _priv->flags = flags;
73 return old_flags;
74}
75
76static unsigned long ieee80211_tkip_get_flags(void *priv)
77{
78 struct ieee80211_tkip_data *_priv = priv;
79 return _priv->flags;
80}
81
82static void *ieee80211_tkip_init(int key_idx)
b453872c
JG		 83{
84 struct ieee80211_tkip_data *priv;
85
8aa914b7 86 priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
b453872c
JG		 87 if (priv == NULL)
88 goto fail;
20d64713 89
b453872c
JG		 90 priv->key_idx = key_idx;
91
28eb177d 92 priv->tx_tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0,
f12cc209 93 CRYPTO_ALG_ASYNC);
28eb177d 94 if (IS_ERR(priv->tx_tfm_arc4)) {
b453872c
JG		 95 printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
96 "crypto API arc4\n");
18379879 97 priv->tx_tfm_arc4 = NULL;
b453872c
JG		 98 goto fail;
99 }
100
28eb177d
JG		 101 priv->tx_tfm_michael = crypto_alloc_hash("michael_mic", 0,
102 CRYPTO_ALG_ASYNC);
103 if (IS_ERR(priv->tx_tfm_michael)) {
5a656949
ZY		 104 printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
105 "crypto API michael_mic\n");
18379879 106 priv->tx_tfm_michael = NULL;
5a656949
ZY		 107 goto fail;
108 }
109
28eb177d
JG		 110 priv->rx_tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0,
111 CRYPTO_ALG_ASYNC);
112 if (IS_ERR(priv->rx_tfm_arc4)) {
5a656949
ZY		 113 printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
114 "crypto API arc4\n");
18379879 115 priv->rx_tfm_arc4 = NULL;
5a656949
ZY		 116 goto fail;
117 }
118
28eb177d
JG		 119 priv->rx_tfm_michael = crypto_alloc_hash("michael_mic", 0,
120 CRYPTO_ALG_ASYNC);
121 if (IS_ERR(priv->rx_tfm_michael)) {
b453872c
JG		 122 printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate "
123 "crypto API michael_mic\n");
18379879 124 priv->rx_tfm_michael = NULL;
b453872c
JG		 125 goto fail;
126 }
127
128 return priv;
129
0edd5b44 130 fail:
b453872c 131 if (priv) {
5a656949 132 if (priv->tx_tfm_michael)
28eb177d 133 crypto_free_hash(priv->tx_tfm_michael);
5a656949 134 if (priv->tx_tfm_arc4)
28eb177d 135 crypto_free_blkcipher(priv->tx_tfm_arc4);
5a656949 136 if (priv->rx_tfm_michael)
28eb177d 137 crypto_free_hash(priv->rx_tfm_michael);
5a656949 138 if (priv->rx_tfm_arc4)
28eb177d 139 crypto_free_blkcipher(priv->rx_tfm_arc4);
b453872c
JG		 140 kfree(priv);
141 }
142
143 return NULL;
144}
145
b453872c
JG		 146static void ieee80211_tkip_deinit(void *priv)
147{
148 struct ieee80211_tkip_data *_priv = priv;
5a656949
ZY		 149 if (_priv) {
150 if (_priv->tx_tfm_michael)
28eb177d 151 crypto_free_hash(_priv->tx_tfm_michael);
5a656949 152 if (_priv->tx_tfm_arc4)
28eb177d 153 crypto_free_blkcipher(_priv->tx_tfm_arc4);
5a656949 154 if (_priv->rx_tfm_michael)
28eb177d 155 crypto_free_hash(_priv->rx_tfm_michael);
5a656949 156 if (_priv->rx_tfm_arc4)
28eb177d 157 crypto_free_blkcipher(_priv->rx_tfm_arc4);
5a656949 158 }
b453872c
JG		 159 kfree(priv);
160}
161
b453872c
JG		 162static inline u16 RotR1(u16 val)
163{
164 return (val >> 1) | (val << 15);
165}
166
b453872c
JG		 167static inline u8 Lo8(u16 val)
168{
169 return val & 0xff;
170}
171
b453872c
JG		 172static inline u8 Hi8(u16 val)
173{
174 return val >> 8;
175}
176
b453872c
JG		 177static inline u16 Lo16(u32 val)
178{
179 return val & 0xffff;
180}
181
b453872c
JG		 182static inline u16 Hi16(u32 val)
183{
184 return val >> 16;
185}
186
b453872c
JG		 187static inline u16 Mk16(u8 hi, u8 lo)
188{
189 return lo | (((u16) hi) << 8);
190}
191
0edd5b44 192static inline u16 Mk16_le(u16 * v)
b453872c
JG		 193{
194 return le16_to_cpu(*v);
195}
196
0edd5b44 197static const u16 Sbox[256] = {
b453872c
JG		 198 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154,
199 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A,
200 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B,
201 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B,
202 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F,
203 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F,
204 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5,
205 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F,
206 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB,
207 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397,
208 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED,
209 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A,
210 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194,
211 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3,
212 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104,
213 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D,
214 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39,
215 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695,
216 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83,
217 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76,
218 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4,
219 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B,
220 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0,
221 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018,
222 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751,
223 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85,
224 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12,
225 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9,
226 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7,
227 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A,
228 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8,
229 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A,
230};
231
b453872c
JG		 232static inline u16 _S_(u16 v)
233{
234 u16 t = Sbox[Hi8(v)];
235 return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8));
236}
237
b453872c
JG		 238#define PHASE1_LOOP_COUNT 8
239
0edd5b44
JG		 240static void tkip_mixing_phase1(u16 * TTAK, const u8 * TK, const u8 * TA,
241 u32 IV32)
b453872c
JG		 242{
243 int i, j;
244
245 /* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */
246 TTAK[0] = Lo16(IV32);
247 TTAK[1] = Hi16(IV32);
248 TTAK[2] = Mk16(TA[1], TA[0]);
249 TTAK[3] = Mk16(TA[3], TA[2]);
250 TTAK[4] = Mk16(TA[5], TA[4]);
251
252 for (i = 0; i < PHASE1_LOOP_COUNT; i++) {
253 j = 2 * (i & 1);
254 TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j]));
255 TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j]));
256 TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j]));
257 TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j]));
258 TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i;
259 }
260}
261
0edd5b44 262static void tkip_mixing_phase2(u8 * WEPSeed, const u8 * TK, const u16 * TTAK,
b453872c
JG		 263 u16 IV16)
264{
265 /* Make temporary area overlap WEP seed so that the final copy can be
266 * avoided on little endian hosts. */
0edd5b44 267 u16 *PPK = (u16 *) & WEPSeed[4];
b453872c
JG		 268
269 /* Step 1 - make copy of TTAK and bring in TSC */
270 PPK[0] = TTAK[0];
271 PPK[1] = TTAK[1];
272 PPK[2] = TTAK[2];
273 PPK[3] = TTAK[3];
274 PPK[4] = TTAK[4];
275 PPK[5] = TTAK[4] + IV16;
276
277 /* Step 2 - 96-bit bijective mixing using S-box */
0edd5b44
JG		 278 PPK[0] += _S_(PPK[5] ^ Mk16_le((u16 *) & TK[0]));
279 PPK[1] += _S_(PPK[0] ^ Mk16_le((u16 *) & TK[2]));
280 PPK[2] += _S_(PPK[1] ^ Mk16_le((u16 *) & TK[4]));
281 PPK[3] += _S_(PPK[2] ^ Mk16_le((u16 *) & TK[6]));
282 PPK[4] += _S_(PPK[3] ^ Mk16_le((u16 *) & TK[8]));
283 PPK[5] += _S_(PPK[4] ^ Mk16_le((u16 *) & TK[10]));
284
285 PPK[0] += RotR1(PPK[5] ^ Mk16_le((u16 *) & TK[12]));
286 PPK[1] += RotR1(PPK[0] ^ Mk16_le((u16 *) & TK[14]));
b453872c
JG		 287 PPK[2] += RotR1(PPK[1]);
288 PPK[3] += RotR1(PPK[2]);
289 PPK[4] += RotR1(PPK[3]);
290 PPK[5] += RotR1(PPK[4]);
291
292 /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value
293 * WEPSeed[0..2] is transmitted as WEP IV */
294 WEPSeed[0] = Hi8(IV16);
295 WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F;
296 WEPSeed[2] = Lo8(IV16);
0edd5b44 297 WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((u16 *) & TK[0])) >> 1);
b453872c
JG		 298
299#ifdef __BIG_ENDIAN
300 {
301 int i;
302 for (i = 0; i < 6; i++)
303 PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8);
304 }
305#endif
306}
307
9184d934
ZY		 308static int ieee80211_tkip_hdr(struct sk_buff *skb, int hdr_len,
309 u8 * rc4key, int keylen, void *priv)
b453872c
JG		 310{
311 struct ieee80211_tkip_data *tkey = priv;
312 int len;
9184d934 313 u8 *pos;
ee34af37 314 struct ieee80211_hdr_4addr *hdr;
b453872c 315
ee34af37 316 hdr = (struct ieee80211_hdr_4addr *)skb->data;
20d64713 317
31b59eae 318 if (skb_headroom(skb) < 8 || skb->len < hdr_len)
9184d934
ZY		 319 return -1;
320
321 if (rc4key == NULL || keylen < 16)
322 return -1;
b453872c 323
b453872c
JG		 324 if (!tkey->tx_phase1_done) {
325 tkip_mixing_phase1(tkey->tx_ttak, tkey->key, hdr->addr2,
326 tkey->tx_iv32);
327 tkey->tx_phase1_done = 1;
328 }
329 tkip_mixing_phase2(rc4key, tkey->key, tkey->tx_ttak, tkey->tx_iv16);
330
331 len = skb->len - hdr_len;
332 pos = skb_push(skb, 8);
333 memmove(pos, pos + 8, hdr_len);
334 pos += hdr_len;
b453872c 335
31b59eae
JK		 336 *pos++ = *rc4key;
337 *pos++ = *(rc4key + 1);
338 *pos++ = *(rc4key + 2);
0edd5b44 339 *pos++ = (tkey->key_idx << 6) | (1 << 5) /* Ext IV included */ ;
b453872c
JG		 340 *pos++ = tkey->tx_iv32 & 0xff;
341 *pos++ = (tkey->tx_iv32 >> 8) & 0xff;
342 *pos++ = (tkey->tx_iv32 >> 16) & 0xff;
343 *pos++ = (tkey->tx_iv32 >> 24) & 0xff;
344
9184d934
ZY		 345 tkey->tx_iv16++;
346 if (tkey->tx_iv16 == 0) {
347 tkey->tx_phase1_done = 0;
348 tkey->tx_iv32++;
349 }
b453872c 350
9184d934 351 return 8;
31b59eae
JK		 352}
353
354static int ieee80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
355{
356 struct ieee80211_tkip_data *tkey = priv;
28eb177d 357 struct blkcipher_desc desc = { .tfm = tkey->tx_tfm_arc4 };
31b59eae 358 int len;
9184d934
ZY		 359 u8 rc4key[16], *pos, *icv;
360 u32 crc;
31b59eae
JK		 361 struct scatterlist sg;
362
6eb6edf0 363 if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
31b59eae
JK		 364 if (net_ratelimit()) {
365 struct ieee80211_hdr_4addr *hdr =
366 (struct ieee80211_hdr_4addr *)skb->data;
9184d934 367 printk(KERN_DEBUG ": TKIP countermeasures: dropped "
31b59eae 368 "TX packet to " MAC_FMT "\n",
6eb6edf0 369 MAC_ARG(hdr->addr1));
31b59eae
JK		 370 }
371 return -1;
372 }
373
374 if (skb_tailroom(skb) < 4 || skb->len < hdr_len)
375 return -1;
376
377 len = skb->len - hdr_len;
378 pos = skb->data + hdr_len;
379
9184d934 380 if ((ieee80211_tkip_hdr(skb, hdr_len, rc4key, 16, priv)) < 0)
31b59eae
JK		 381 return -1;
382
9184d934
ZY		 383 icv = skb_put(skb, 4);
384
385 crc = ~crc32_le(~0, pos, len);
386 icv[0] = crc;
387 icv[1] = crc >> 8;
388 icv[2] = crc >> 16;
389 icv[3] = crc >> 24;
390
28eb177d 391 crypto_blkcipher_setkey(tkey->tx_tfm_arc4, rc4key, 16);
b453872c
JG		 392 sg.page = virt_to_page(pos);
393 sg.offset = offset_in_page(pos);
394 sg.length = len + 4;
f12cc209 395 return crypto_blkcipher_encrypt(&desc, &sg, &sg, len + 4);
b4328d87
ZY		 396}
397
18379879
JG		 398/*
399 * deal with seq counter wrapping correctly.
400 * refer to timer_after() for jiffies wrapping handling
401 */
402static inline int tkip_replay_check(u32 iv32_n, u16 iv16_n,
403 u32 iv32_o, u16 iv16_o)
404{
405 if ((s32)iv32_n - (s32)iv32_o < 0 ||
406 (iv32_n == iv32_o && iv16_n <= iv16_o))
407 return 1;
408 return 0;
409}
410
b453872c
JG		 411static int ieee80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
412{
413 struct ieee80211_tkip_data *tkey = priv;
28eb177d 414 struct blkcipher_desc desc = { .tfm = tkey->rx_tfm_arc4 };
b453872c
JG		 415 u8 rc4key[16];
416 u8 keyidx, *pos;
417 u32 iv32;
418 u16 iv16;
ee34af37 419 struct ieee80211_hdr_4addr *hdr;
b453872c
JG		 420 u8 icv[4];
421 u32 crc;
422 struct scatterlist sg;
423 int plen;
424
ee34af37 425 hdr = (struct ieee80211_hdr_4addr *)skb->data;
20d64713 426
6eb6edf0 427 if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
20d64713 428 if (net_ratelimit()) {
9184d934 429 printk(KERN_DEBUG ": TKIP countermeasures: dropped "
20d64713 430 "received packet from " MAC_FMT "\n",
6eb6edf0 431 MAC_ARG(hdr->addr2));
20d64713
JK		 432 }
433 return -1;
434 }
435
b453872c
JG		 436 if (skb->len < hdr_len + 8 + 4)
437 return -1;
438
b453872c
JG		 439 pos = skb->data + hdr_len;
440 keyidx = pos[3];
441 if (!(keyidx & (1 << 5))) {
442 if (net_ratelimit()) {
443 printk(KERN_DEBUG "TKIP: received packet without ExtIV"
444 " flag from " MAC_FMT "\n", MAC_ARG(hdr->addr2));
445 }
446 return -2;
447 }
448 keyidx >>= 6;
449 if (tkey->key_idx != keyidx) {
450 printk(KERN_DEBUG "TKIP: RX tkey->key_idx=%d frame "
451 "keyidx=%d priv=%p\n", tkey->key_idx, keyidx, priv);
452 return -6;
453 }
454 if (!tkey->key_set) {
455 if (net_ratelimit()) {
456 printk(KERN_DEBUG "TKIP: received packet from " MAC_FMT
457 " with keyid=%d that does not have a configured"
458 " key\n", MAC_ARG(hdr->addr2), keyidx);
459 }
460 return -3;
461 }
462 iv16 = (pos[0] << 8) | pos[2];
463 iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24);
464 pos += 8;
465
b4328d87 466 if (tkip_replay_check(iv32, iv16, tkey->rx_iv32, tkey->rx_iv16)) {
b453872c
JG		 467 if (net_ratelimit()) {
468 printk(KERN_DEBUG "TKIP: replay detected: STA=" MAC_FMT
469 " previous TSC %08x%04x received TSC "
470 "%08x%04x\n", MAC_ARG(hdr->addr2),
471 tkey->rx_iv32, tkey->rx_iv16, iv32, iv16);
472 }
473 tkey->dot11RSNAStatsTKIPReplays++;
474 return -4;
475 }
476
477 if (iv32 != tkey->rx_iv32 || !tkey->rx_phase1_done) {
478 tkip_mixing_phase1(tkey->rx_ttak, tkey->key, hdr->addr2, iv32);
479 tkey->rx_phase1_done = 1;
480 }
481 tkip_mixing_phase2(rc4key, tkey->key, tkey->rx_ttak, iv16);
482
483 plen = skb->len - hdr_len - 12;
484
28eb177d 485 crypto_blkcipher_setkey(tkey->rx_tfm_arc4, rc4key, 16);
b453872c
JG		 486 sg.page = virt_to_page(pos);
487 sg.offset = offset_in_page(pos);
488 sg.length = plen + 4;
f12cc209
HX		 489 if (crypto_blkcipher_decrypt(&desc, &sg, &sg, plen + 4)) {
490 if (net_ratelimit()) {
491 printk(KERN_DEBUG ": TKIP: failed to decrypt "
492 "received packet from " MAC_FMT "\n",
493 MAC_ARG(hdr->addr2));
494 }
495 return -7;
496 }
b453872c
JG		 497
498 crc = ~crc32_le(~0, pos, plen);
499 icv[0] = crc;
500 icv[1] = crc >> 8;
501 icv[2] = crc >> 16;
502 icv[3] = crc >> 24;
503 if (memcmp(icv, pos + plen, 4) != 0) {
504 if (iv32 != tkey->rx_iv32) {
505 /* Previously cached Phase1 result was already lost, so
506 * it needs to be recalculated for the next packet. */
507 tkey->rx_phase1_done = 0;
508 }
509 if (net_ratelimit()) {
510 printk(KERN_DEBUG "TKIP: ICV error detected: STA="
511 MAC_FMT "\n", MAC_ARG(hdr->addr2));
512 }
513 tkey->dot11RSNAStatsTKIPICVErrors++;
514 return -5;
515 }
516
517 /* Update real counters only after Michael MIC verification has
518 * completed */
519 tkey->rx_iv32_new = iv32;
520 tkey->rx_iv16_new = iv16;
521
522 /* Remove IV and ICV */
523 memmove(skb->data + 8, skb->data, hdr_len);
524 skb_pull(skb, 8);
525 skb_trim(skb, skb->len - 4);
526
527 return keyidx;
528}
529
28eb177d 530static int michael_mic(struct crypto_hash *tfm_michael, u8 * key, u8 * hdr,
0edd5b44 531 u8 * data, size_t data_len, u8 * mic)
b453872c 532{
35058687 533 struct hash_desc desc;
b453872c
JG		 534 struct scatterlist sg[2];
535
5a656949 536 if (tfm_michael == NULL) {
b453872c
JG		 537 printk(KERN_WARNING "michael_mic: tfm_michael == NULL\n");
538 return -1;
539 }
540 sg[0].page = virt_to_page(hdr);
541 sg[0].offset = offset_in_page(hdr);
542 sg[0].length = 16;
543
544 sg[1].page = virt_to_page(data);
545 sg[1].offset = offset_in_page(data);
546 sg[1].length = data_len;
547
28eb177d 548 if (crypto_hash_setkey(tfm_michael, key, 8))
35058687 549 return -1;
b453872c 550
28eb177d 551 desc.tfm = tfm_michael;
35058687
HX		 552 desc.flags = 0;
553 return crypto_hash_digest(&desc, sg, data_len + 16, mic);
b453872c
JG		 554}
555
0edd5b44 556static void michael_mic_hdr(struct sk_buff *skb, u8 * hdr)
b453872c 557{
ee34af37 558 struct ieee80211_hdr_4addr *hdr11;
ea284152 559 u16 stype;
b453872c 560
ee34af37 561 hdr11 = (struct ieee80211_hdr_4addr *)skb->data;
ea284152
ZY		 562 stype = WLAN_FC_GET_STYPE(le16_to_cpu(hdr11->frame_ctl));
563
b453872c
JG		 564 switch (le16_to_cpu(hdr11->frame_ctl) &
565 (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
566 case IEEE80211_FCTL_TODS:
0edd5b44
JG		 567 memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
568 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
b453872c
JG		 569 break;
570 case IEEE80211_FCTL_FROMDS:
0edd5b44
JG		 571 memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
572 memcpy(hdr + ETH_ALEN, hdr11->addr3, ETH_ALEN); /* SA */
b453872c
JG		 573 break;
574 case IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS:
0edd5b44
JG		 575 memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
576 memcpy(hdr + ETH_ALEN, hdr11->addr4, ETH_ALEN); /* SA */
b453872c
JG		 577 break;
578 case 0:
0edd5b44
JG		 579 memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
580 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
b453872c
JG		 581 break;
582 }
583
ea284152
ZY		 584 if (stype & IEEE80211_STYPE_QOS_DATA) {
585 const struct ieee80211_hdr_3addrqos *qoshdr =
586 (struct ieee80211_hdr_3addrqos *)skb->data;
65b6a277 587 hdr[12] = qoshdr->qos_ctl & cpu_to_le16(IEEE80211_QCTL_TID);
ea284152
ZY		 588 } else
589 hdr[12] = 0; /* priority */
590
0edd5b44 591 hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */
b453872c
JG		 592}
593
0edd5b44
JG		 594static int ieee80211_michael_mic_add(struct sk_buff *skb, int hdr_len,
595 void *priv)
b453872c
JG		 596{
597 struct ieee80211_tkip_data *tkey = priv;
598 u8 *pos;
599
600 if (skb_tailroom(skb) < 8 || skb->len < hdr_len) {
601 printk(KERN_DEBUG "Invalid packet for Michael MIC add "
602 "(tailroom=%d hdr_len=%d skb->len=%d)\n",
603 skb_tailroom(skb), hdr_len, skb->len);
604 return -1;
605 }
606
607 michael_mic_hdr(skb, tkey->tx_hdr);
608 pos = skb_put(skb, 8);
5a656949 609 if (michael_mic(tkey->tx_tfm_michael, &tkey->key[16], tkey->tx_hdr,
b453872c
JG		 610 skb->data + hdr_len, skb->len - 8 - hdr_len, pos))
611 return -1;
612
613 return 0;
614}
615
b453872c 616static void ieee80211_michael_mic_failure(struct net_device *dev,
ee34af37
JK		 617 struct ieee80211_hdr_4addr *hdr,
618 int keyidx)
b453872c
JG		 619{
620 union iwreq_data wrqu;
621 struct iw_michaelmicfailure ev;
622
623 /* TODO: needed parameters: count, keyid, key type, TSC */
624 memset(&ev, 0, sizeof(ev));
625 ev.flags = keyidx & IW_MICFAILURE_KEY_ID;
626 if (hdr->addr1[0] & 0x01)
627 ev.flags |= IW_MICFAILURE_GROUP;
628 else
629 ev.flags |= IW_MICFAILURE_PAIRWISE;
630 ev.src_addr.sa_family = ARPHRD_ETHER;
631 memcpy(ev.src_addr.sa_data, hdr->addr2, ETH_ALEN);
632 memset(&wrqu, 0, sizeof(wrqu));
633 wrqu.data.length = sizeof(ev);
0edd5b44 634 wireless_send_event(dev, IWEVMICHAELMICFAILURE, &wrqu, (char *)&ev);
b453872c 635}
b453872c
JG		 636
637static int ieee80211_michael_mic_verify(struct sk_buff *skb, int keyidx,
0edd5b44 638 int hdr_len, void *priv)
b453872c
JG		 639{
640 struct ieee80211_tkip_data *tkey = priv;
641 u8 mic[8];
642
643 if (!tkey->key_set)
644 return -1;
645
646 michael_mic_hdr(skb, tkey->rx_hdr);
5a656949 647 if (michael_mic(tkey->rx_tfm_michael, &tkey->key[24], tkey->rx_hdr,
b453872c
JG		 648 skb->data + hdr_len, skb->len - 8 - hdr_len, mic))
649 return -1;
650 if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) {
ee34af37
JK		 651 struct ieee80211_hdr_4addr *hdr;
652 hdr = (struct ieee80211_hdr_4addr *)skb->data;
b453872c
JG		 653 printk(KERN_DEBUG "%s: Michael MIC verification failed for "
654 "MSDU from " MAC_FMT " keyidx=%d\n",
655 skb->dev ? skb->dev->name : "N/A", MAC_ARG(hdr->addr2),
656 keyidx);
657 if (skb->dev)
658 ieee80211_michael_mic_failure(skb->dev, hdr, keyidx);
659 tkey->dot11RSNAStatsTKIPLocalMICFailures++;
660 return -1;
661 }
662
663 /* Update TSC counters for RX now that the packet verification has
664 * completed. */
665 tkey->rx_iv32 = tkey->rx_iv32_new;
666 tkey->rx_iv16 = tkey->rx_iv16_new;
667
668 skb_trim(skb, skb->len - 8);
669
670 return 0;
671}
672
0edd5b44 673static int ieee80211_tkip_set_key(void *key, int len, u8 * seq, void *priv)
b453872c
JG		 674{
675 struct ieee80211_tkip_data *tkey = priv;
676 int keyidx;
28eb177d
JG		 677 struct crypto_hash *tfm = tkey->tx_tfm_michael;
678 struct crypto_blkcipher *tfm2 = tkey->tx_tfm_arc4;
679 struct crypto_hash *tfm3 = tkey->rx_tfm_michael;
680 struct crypto_blkcipher *tfm4 = tkey->rx_tfm_arc4;
b453872c
JG		 681
682 keyidx = tkey->key_idx;
683 memset(tkey, 0, sizeof(*tkey));
684 tkey->key_idx = keyidx;
5a656949
ZY		 685 tkey->tx_tfm_michael = tfm;
686 tkey->tx_tfm_arc4 = tfm2;
687 tkey->rx_tfm_michael = tfm3;
688 tkey->rx_tfm_arc4 = tfm4;
b453872c
JG		 689 if (len == TKIP_KEY_LEN) {
690 memcpy(tkey->key, key, TKIP_KEY_LEN);
691 tkey->key_set = 1;
0edd5b44 692 tkey->tx_iv16 = 1; /* TSC is initialized to 1 */
b453872c
JG		 693 if (seq) {
694 tkey->rx_iv32 = (seq[5] << 24) | (seq[4] << 16) |
0edd5b44 695 (seq[3] << 8) | seq[2];
b453872c
JG		 696 tkey->rx_iv16 = (seq[1] << 8) | seq[0];
697 }
698 } else if (len == 0)
699 tkey->key_set = 0;
700 else
701 return -1;
702
703 return 0;
704}
705
0edd5b44 706static int ieee80211_tkip_get_key(void *key, int len, u8 * seq, void *priv)
b453872c
JG		 707{
708 struct ieee80211_tkip_data *tkey = priv;
709
710 if (len < TKIP_KEY_LEN)
711 return -1;
712
713 if (!tkey->key_set)
714 return 0;
715 memcpy(key, tkey->key, TKIP_KEY_LEN);
716
717 if (seq) {
718 /* Return the sequence number of the last transmitted frame. */
719 u16 iv16 = tkey->tx_iv16;
720 u32 iv32 = tkey->tx_iv32;
721 if (iv16 == 0)
722 iv32--;
723 iv16--;
724 seq[0] = tkey->tx_iv16;
725 seq[1] = tkey->tx_iv16 >> 8;
726 seq[2] = tkey->tx_iv32;
727 seq[3] = tkey->tx_iv32 >> 8;
728 seq[4] = tkey->tx_iv32 >> 16;
729 seq[5] = tkey->tx_iv32 >> 24;
730 }
731
732 return TKIP_KEY_LEN;
733}
734
0edd5b44 735static char *ieee80211_tkip_print_stats(char *p, void *priv)
b453872c
JG		 736{
737 struct ieee80211_tkip_data *tkip = priv;
738 p += sprintf(p, "key[%d] alg=TKIP key_set=%d "
739 "tx_pn=%02x%02x%02x%02x%02x%02x "
740 "rx_pn=%02x%02x%02x%02x%02x%02x "
741 "replays=%d icv_errors=%d local_mic_failures=%d\n",
742 tkip->key_idx, tkip->key_set,
743 (tkip->tx_iv32 >> 24) & 0xff,
744 (tkip->tx_iv32 >> 16) & 0xff,
745 (tkip->tx_iv32 >> 8) & 0xff,
746 tkip->tx_iv32 & 0xff,
747 (tkip->tx_iv16 >> 8) & 0xff,
748 tkip->tx_iv16 & 0xff,
749 (tkip->rx_iv32 >> 24) & 0xff,
750 (tkip->rx_iv32 >> 16) & 0xff,
751 (tkip->rx_iv32 >> 8) & 0xff,
752 tkip->rx_iv32 & 0xff,
753 (tkip->rx_iv16 >> 8) & 0xff,
754 tkip->rx_iv16 & 0xff,
755 tkip->dot11RSNAStatsTKIPReplays,
756 tkip->dot11RSNAStatsTKIPICVErrors,
757 tkip->dot11RSNAStatsTKIPLocalMICFailures);
758 return p;
759}
760
b453872c 761static struct ieee80211_crypto_ops ieee80211_crypt_tkip = {
74079fdc
JK		 762 .name = "TKIP",
763 .init = ieee80211_tkip_init,
764 .deinit = ieee80211_tkip_deinit,
9184d934 765 .build_iv = ieee80211_tkip_hdr,
74079fdc
JK		 766 .encrypt_mpdu = ieee80211_tkip_encrypt,
767 .decrypt_mpdu = ieee80211_tkip_decrypt,
768 .encrypt_msdu = ieee80211_michael_mic_add,
769 .decrypt_msdu = ieee80211_michael_mic_verify,
770 .set_key = ieee80211_tkip_set_key,
771 .get_key = ieee80211_tkip_get_key,
772 .print_stats = ieee80211_tkip_print_stats,
1264fc04
JK		 773 .extra_mpdu_prefix_len = 4 + 4, /* IV + ExtIV */
774 .extra_mpdu_postfix_len = 4, /* ICV */
775 .extra_msdu_postfix_len = 8, /* MIC */
6eb6edf0
JK		 776 .get_flags = ieee80211_tkip_get_flags,
777 .set_flags = ieee80211_tkip_set_flags,
74079fdc 778 .owner = THIS_MODULE,
b453872c
JG		 779};
780
b453872c
JG		 781static int __init ieee80211_crypto_tkip_init(void)
782{
783 return ieee80211_register_crypto_ops(&ieee80211_crypt_tkip);
784}
785
b453872c
JG		 786static void __exit ieee80211_crypto_tkip_exit(void)
787{
788 ieee80211_unregister_crypto_ops(&ieee80211_crypt_tkip);
789}
790
b453872c
JG		 791module_init(ieee80211_crypto_tkip_init);
792module_exit(ieee80211_crypto_tkip_exit);
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