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1/*
2 * lib80211 crypt: host-based TKIP encryption implementation for lib80211
3 *
4 * Copyright (c) 2003-2004, Jouni Malinen <j@w1.fi>
5 * Copyright (c) 2008, John W. Linville <linville@tuxdriver.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation. See README and COPYING for
10 * more details.
11 */
12
13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15#include <linux/err.h>
16#include <linux/module.h>
17#include <linux/init.h>
18#include <linux/slab.h>
19#include <linux/random.h>
20#include <linux/scatterlist.h>
21#include <linux/skbuff.h>
22#include <linux/netdevice.h>
23#include <linux/mm.h>
24#include <linux/if_ether.h>
25#include <linux/if_arp.h>
26#include <asm/string.h>
27
28#include <linux/wireless.h>
29#include <linux/ieee80211.h>
30#include <net/iw_handler.h>
31
32#include <crypto/hash.h>
33#include <crypto/skcipher.h>
34#include <linux/crc32.h>
35
36#include <net/lib80211.h>
37
38MODULE_AUTHOR("Jouni Malinen");
39MODULE_DESCRIPTION("lib80211 crypt: TKIP");
40MODULE_LICENSE("GPL");
41
42#define TKIP_HDR_LEN 8
43
44struct lib80211_tkip_data {
45#define TKIP_KEY_LEN 32
46 u8 key[TKIP_KEY_LEN];
47 int key_set;
48
49 u32 tx_iv32;
50 u16 tx_iv16;
51 u16 tx_ttak[5];
52 int tx_phase1_done;
53
54 u32 rx_iv32;
55 u16 rx_iv16;
56 u16 rx_ttak[5];
57 int rx_phase1_done;
58 u32 rx_iv32_new;
59 u16 rx_iv16_new;
60
61 u32 dot11RSNAStatsTKIPReplays;
62 u32 dot11RSNAStatsTKIPICVErrors;
63 u32 dot11RSNAStatsTKIPLocalMICFailures;
64
65 int key_idx;
66
67 struct crypto_skcipher *rx_tfm_arc4;
68 struct crypto_ahash *rx_tfm_michael;
69 struct crypto_skcipher *tx_tfm_arc4;
70 struct crypto_ahash *tx_tfm_michael;
71
72 /* scratch buffers for virt_to_page() (crypto API) */
73 u8 rx_hdr[16], tx_hdr[16];
74
75 unsigned long flags;
76};
77
78static unsigned long lib80211_tkip_set_flags(unsigned long flags, void *priv)
79{
80 struct lib80211_tkip_data *_priv = priv;
81 unsigned long old_flags = _priv->flags;
82 _priv->flags = flags;
83 return old_flags;
84}
85
86static unsigned long lib80211_tkip_get_flags(void *priv)
87{
88 struct lib80211_tkip_data *_priv = priv;
89 return _priv->flags;
90}
91
92static void *lib80211_tkip_init(int key_idx)
93{
94 struct lib80211_tkip_data *priv;
95
96 priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
97 if (priv == NULL)
98 goto fail;
99
100 priv->key_idx = key_idx;
101
102 priv->tx_tfm_arc4 = crypto_alloc_skcipher("ecb(arc4)", 0,
103 CRYPTO_ALG_ASYNC);
104 if (IS_ERR(priv->tx_tfm_arc4)) {
105 priv->tx_tfm_arc4 = NULL;
106 goto fail;
107 }
108
109 priv->tx_tfm_michael = crypto_alloc_ahash("michael_mic", 0,
110 CRYPTO_ALG_ASYNC);
111 if (IS_ERR(priv->tx_tfm_michael)) {
112 priv->tx_tfm_michael = NULL;
113 goto fail;
114 }
115
116 priv->rx_tfm_arc4 = crypto_alloc_skcipher("ecb(arc4)", 0,
117 CRYPTO_ALG_ASYNC);
118 if (IS_ERR(priv->rx_tfm_arc4)) {
119 priv->rx_tfm_arc4 = NULL;
120 goto fail;
121 }
122
123 priv->rx_tfm_michael = crypto_alloc_ahash("michael_mic", 0,
124 CRYPTO_ALG_ASYNC);
125 if (IS_ERR(priv->rx_tfm_michael)) {
126 priv->rx_tfm_michael = NULL;
127 goto fail;
128 }
129
130 return priv;
131
132 fail:
133 if (priv) {
134 crypto_free_ahash(priv->tx_tfm_michael);
135 crypto_free_skcipher(priv->tx_tfm_arc4);
136 crypto_free_ahash(priv->rx_tfm_michael);
137 crypto_free_skcipher(priv->rx_tfm_arc4);
138 kfree(priv);
139 }
140
141 return NULL;
142}
143
144static void lib80211_tkip_deinit(void *priv)
145{
146 struct lib80211_tkip_data *_priv = priv;
147 if (_priv) {
148 crypto_free_ahash(_priv->tx_tfm_michael);
149 crypto_free_skcipher(_priv->tx_tfm_arc4);
150 crypto_free_ahash(_priv->rx_tfm_michael);
151 crypto_free_skcipher(_priv->rx_tfm_arc4);
152 }
153 kfree(priv);
154}
155
156static inline u16 RotR1(u16 val)
157{
158 return (val >> 1) | (val << 15);
159}
160
161static inline u8 Lo8(u16 val)
162{
163 return val & 0xff;
164}
165
166static inline u8 Hi8(u16 val)
167{
168 return val >> 8;
169}
170
171static inline u16 Lo16(u32 val)
172{
173 return val & 0xffff;
174}
175
176static inline u16 Hi16(u32 val)
177{
178 return val >> 16;
179}
180
181static inline u16 Mk16(u8 hi, u8 lo)
182{
183 return lo | (((u16) hi) << 8);
184}
185
186static inline u16 Mk16_le(__le16 * v)
187{
188 return le16_to_cpu(*v);
189}
190
191static const u16 Sbox[256] = {
192 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154,
193 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A,
194 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B,
195 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B,
196 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F,
197 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F,
198 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5,
199 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F,
200 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB,
201 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397,
202 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED,
203 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A,
204 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194,
205 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3,
206 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104,
207 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D,
208 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39,
209 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695,
210 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83,
211 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76,
212 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4,
213 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B,
214 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0,
215 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018,
216 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751,
217 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85,
218 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12,
219 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9,
220 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7,
221 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A,
222 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8,
223 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A,
224};
225
226static inline u16 _S_(u16 v)
227{
228 u16 t = Sbox[Hi8(v)];
229 return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8));
230}
231
232#define PHASE1_LOOP_COUNT 8
233
234static void tkip_mixing_phase1(u16 * TTAK, const u8 * TK, const u8 * TA,
235 u32 IV32)
236{
237 int i, j;
238
239 /* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */
240 TTAK[0] = Lo16(IV32);
241 TTAK[1] = Hi16(IV32);
242 TTAK[2] = Mk16(TA[1], TA[0]);
243 TTAK[3] = Mk16(TA[3], TA[2]);
244 TTAK[4] = Mk16(TA[5], TA[4]);
245
246 for (i = 0; i < PHASE1_LOOP_COUNT; i++) {
247 j = 2 * (i & 1);
248 TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j]));
249 TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j]));
250 TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j]));
251 TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j]));
252 TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i;
253 }
254}
255
256static void tkip_mixing_phase2(u8 * WEPSeed, const u8 * TK, const u16 * TTAK,
257 u16 IV16)
258{
259 /* Make temporary area overlap WEP seed so that the final copy can be
260 * avoided on little endian hosts. */
261 u16 *PPK = (u16 *) & WEPSeed[4];
262
263 /* Step 1 - make copy of TTAK and bring in TSC */
264 PPK[0] = TTAK[0];
265 PPK[1] = TTAK[1];
266 PPK[2] = TTAK[2];
267 PPK[3] = TTAK[3];
268 PPK[4] = TTAK[4];
269 PPK[5] = TTAK[4] + IV16;
270
271 /* Step 2 - 96-bit bijective mixing using S-box */
272 PPK[0] += _S_(PPK[5] ^ Mk16_le((__le16 *) & TK[0]));
273 PPK[1] += _S_(PPK[0] ^ Mk16_le((__le16 *) & TK[2]));
274 PPK[2] += _S_(PPK[1] ^ Mk16_le((__le16 *) & TK[4]));
275 PPK[3] += _S_(PPK[2] ^ Mk16_le((__le16 *) & TK[6]));
276 PPK[4] += _S_(PPK[3] ^ Mk16_le((__le16 *) & TK[8]));
277 PPK[5] += _S_(PPK[4] ^ Mk16_le((__le16 *) & TK[10]));
278
279 PPK[0] += RotR1(PPK[5] ^ Mk16_le((__le16 *) & TK[12]));
280 PPK[1] += RotR1(PPK[0] ^ Mk16_le((__le16 *) & TK[14]));
281 PPK[2] += RotR1(PPK[1]);
282 PPK[3] += RotR1(PPK[2]);
283 PPK[4] += RotR1(PPK[3]);
284 PPK[5] += RotR1(PPK[4]);
285
286 /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value
287 * WEPSeed[0..2] is transmitted as WEP IV */
288 WEPSeed[0] = Hi8(IV16);
289 WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F;
290 WEPSeed[2] = Lo8(IV16);
291 WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((__le16 *) & TK[0])) >> 1);
292
293#ifdef __BIG_ENDIAN
294 {
295 int i;
296 for (i = 0; i < 6; i++)
297 PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8);
298 }
299#endif
300}
301
302static int lib80211_tkip_hdr(struct sk_buff *skb, int hdr_len,
303 u8 * rc4key, int keylen, void *priv)
304{
305 struct lib80211_tkip_data *tkey = priv;
306 u8 *pos;
307 struct ieee80211_hdr *hdr;
308
309 hdr = (struct ieee80211_hdr *)skb->data;
310
311 if (skb_headroom(skb) < TKIP_HDR_LEN || skb->len < hdr_len)
312 return -1;
313
314 if (rc4key == NULL || keylen < 16)
315 return -1;
316
317 if (!tkey->tx_phase1_done) {
318 tkip_mixing_phase1(tkey->tx_ttak, tkey->key, hdr->addr2,
319 tkey->tx_iv32);
320 tkey->tx_phase1_done = 1;
321 }
322 tkip_mixing_phase2(rc4key, tkey->key, tkey->tx_ttak, tkey->tx_iv16);
323
324 pos = skb_push(skb, TKIP_HDR_LEN);
325 memmove(pos, pos + TKIP_HDR_LEN, hdr_len);
326 pos += hdr_len;
327
328 *pos++ = *rc4key;
329 *pos++ = *(rc4key + 1);
330 *pos++ = *(rc4key + 2);
331 *pos++ = (tkey->key_idx << 6) | (1 << 5) /* Ext IV included */ ;
332 *pos++ = tkey->tx_iv32 & 0xff;
333 *pos++ = (tkey->tx_iv32 >> 8) & 0xff;
334 *pos++ = (tkey->tx_iv32 >> 16) & 0xff;
335 *pos++ = (tkey->tx_iv32 >> 24) & 0xff;
336
337 tkey->tx_iv16++;
338 if (tkey->tx_iv16 == 0) {
339 tkey->tx_phase1_done = 0;
340 tkey->tx_iv32++;
341 }
342
343 return TKIP_HDR_LEN;
344}
345
346static int lib80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
347{
348 struct lib80211_tkip_data *tkey = priv;
349 SKCIPHER_REQUEST_ON_STACK(req, tkey->tx_tfm_arc4);
350 int len;
351 u8 rc4key[16], *pos, *icv;
352 u32 crc;
353 struct scatterlist sg;
354 int err;
355
356 if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
357 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
358 net_dbg_ratelimited("TKIP countermeasures: dropped TX packet to %pM\n",
359 hdr->addr1);
360 return -1;
361 }
362
363 if (skb_tailroom(skb) < 4 || skb->len < hdr_len)
364 return -1;
365
366 len = skb->len - hdr_len;
367 pos = skb->data + hdr_len;
368
369 if ((lib80211_tkip_hdr(skb, hdr_len, rc4key, 16, priv)) < 0)
370 return -1;
371
372 crc = ~crc32_le(~0, pos, len);
373 icv = skb_put(skb, 4);
374 icv[0] = crc;
375 icv[1] = crc >> 8;
376 icv[2] = crc >> 16;
377 icv[3] = crc >> 24;
378
379 crypto_skcipher_setkey(tkey->tx_tfm_arc4, rc4key, 16);
380 sg_init_one(&sg, pos, len + 4);
381 skcipher_request_set_tfm(req, tkey->tx_tfm_arc4);
382 skcipher_request_set_callback(req, 0, NULL, NULL);
383 skcipher_request_set_crypt(req, &sg, &sg, len + 4, NULL);
384 err = crypto_skcipher_encrypt(req);
385 skcipher_request_zero(req);
386 return err;
387}
388
389/*
390 * deal with seq counter wrapping correctly.
391 * refer to timer_after() for jiffies wrapping handling
392 */
393static inline int tkip_replay_check(u32 iv32_n, u16 iv16_n,
394 u32 iv32_o, u16 iv16_o)
395{
396 if ((s32)iv32_n - (s32)iv32_o < 0 ||
397 (iv32_n == iv32_o && iv16_n <= iv16_o))
398 return 1;
399 return 0;
400}
401
402static int lib80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
403{
404 struct lib80211_tkip_data *tkey = priv;
405 SKCIPHER_REQUEST_ON_STACK(req, tkey->rx_tfm_arc4);
406 u8 rc4key[16];
407 u8 keyidx, *pos;
408 u32 iv32;
409 u16 iv16;
410 struct ieee80211_hdr *hdr;
411 u8 icv[4];
412 u32 crc;
413 struct scatterlist sg;
414 int plen;
415 int err;
416
417 hdr = (struct ieee80211_hdr *)skb->data;
418
419 if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
420 net_dbg_ratelimited("TKIP countermeasures: dropped received packet from %pM\n",
421 hdr->addr2);
422 return -1;
423 }
424
425 if (skb->len < hdr_len + TKIP_HDR_LEN + 4)
426 return -1;
427
428 pos = skb->data + hdr_len;
429 keyidx = pos[3];
430 if (!(keyidx & (1 << 5))) {
431 net_dbg_ratelimited("TKIP: received packet without ExtIV flag from %pM\n",
432 hdr->addr2);
433 return -2;
434 }
435 keyidx >>= 6;
436 if (tkey->key_idx != keyidx) {
437 net_dbg_ratelimited("TKIP: RX tkey->key_idx=%d frame keyidx=%d\n",
438 tkey->key_idx, keyidx);
439 return -6;
440 }
441 if (!tkey->key_set) {
442 net_dbg_ratelimited("TKIP: received packet from %pM with keyid=%d that does not have a configured key\n",
443 hdr->addr2, keyidx);
444 return -3;
445 }
446 iv16 = (pos[0] << 8) | pos[2];
447 iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24);
448 pos += TKIP_HDR_LEN;
449
450 if (tkip_replay_check(iv32, iv16, tkey->rx_iv32, tkey->rx_iv16)) {
451#ifdef CONFIG_LIB80211_DEBUG
452 net_dbg_ratelimited("TKIP: replay detected: STA=%pM previous TSC %08x%04x received TSC %08x%04x\n",
453 hdr->addr2, tkey->rx_iv32, tkey->rx_iv16,
454 iv32, iv16);
455#endif
456 tkey->dot11RSNAStatsTKIPReplays++;
457 return -4;
458 }
459
460 if (iv32 != tkey->rx_iv32 || !tkey->rx_phase1_done) {
461 tkip_mixing_phase1(tkey->rx_ttak, tkey->key, hdr->addr2, iv32);
462 tkey->rx_phase1_done = 1;
463 }
464 tkip_mixing_phase2(rc4key, tkey->key, tkey->rx_ttak, iv16);
465
466 plen = skb->len - hdr_len - 12;
467
468 crypto_skcipher_setkey(tkey->rx_tfm_arc4, rc4key, 16);
469 sg_init_one(&sg, pos, plen + 4);
470 skcipher_request_set_tfm(req, tkey->rx_tfm_arc4);
471 skcipher_request_set_callback(req, 0, NULL, NULL);
472 skcipher_request_set_crypt(req, &sg, &sg, plen + 4, NULL);
473 err = crypto_skcipher_decrypt(req);
474 skcipher_request_zero(req);
475 if (err) {
476 net_dbg_ratelimited("TKIP: failed to decrypt received packet from %pM\n",
477 hdr->addr2);
478 return -7;
479 }
480
481 crc = ~crc32_le(~0, pos, plen);
482 icv[0] = crc;
483 icv[1] = crc >> 8;
484 icv[2] = crc >> 16;
485 icv[3] = crc >> 24;
486 if (memcmp(icv, pos + plen, 4) != 0) {
487 if (iv32 != tkey->rx_iv32) {
488 /* Previously cached Phase1 result was already lost, so
489 * it needs to be recalculated for the next packet. */
490 tkey->rx_phase1_done = 0;
491 }
492#ifdef CONFIG_LIB80211_DEBUG
493 net_dbg_ratelimited("TKIP: ICV error detected: STA=%pM\n",
494 hdr->addr2);
495#endif
496 tkey->dot11RSNAStatsTKIPICVErrors++;
497 return -5;
498 }
499
500 /* Update real counters only after Michael MIC verification has
501 * completed */
502 tkey->rx_iv32_new = iv32;
503 tkey->rx_iv16_new = iv16;
504
505 /* Remove IV and ICV */
506 memmove(skb->data + TKIP_HDR_LEN, skb->data, hdr_len);
507 skb_pull(skb, TKIP_HDR_LEN);
508 skb_trim(skb, skb->len - 4);
509
510 return keyidx;
511}
512
513static int michael_mic(struct crypto_ahash *tfm_michael, u8 * key, u8 * hdr,
514 u8 * data, size_t data_len, u8 * mic)
515{
516 AHASH_REQUEST_ON_STACK(req, tfm_michael);
517 struct scatterlist sg[2];
518 int err;
519
520 if (tfm_michael == NULL) {
521 pr_warn("%s(): tfm_michael == NULL\n", __func__);
522 return -1;
523 }
524 sg_init_table(sg, 2);
525 sg_set_buf(&sg[0], hdr, 16);
526 sg_set_buf(&sg[1], data, data_len);
527
528 if (crypto_ahash_setkey(tfm_michael, key, 8))
529 return -1;
530
531 ahash_request_set_tfm(req, tfm_michael);
532 ahash_request_set_callback(req, 0, NULL, NULL);
533 ahash_request_set_crypt(req, sg, mic, data_len + 16);
534 err = crypto_ahash_digest(req);
535 ahash_request_zero(req);
536 return err;
537}
538
539static void michael_mic_hdr(struct sk_buff *skb, u8 * hdr)
540{
541 struct ieee80211_hdr *hdr11;
542
543 hdr11 = (struct ieee80211_hdr *)skb->data;
544
545 switch (le16_to_cpu(hdr11->frame_control) &
546 (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
547 case IEEE80211_FCTL_TODS:
548 memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
549 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
550 break;
551 case IEEE80211_FCTL_FROMDS:
552 memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
553 memcpy(hdr + ETH_ALEN, hdr11->addr3, ETH_ALEN); /* SA */
554 break;
555 case IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS:
556 memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
557 memcpy(hdr + ETH_ALEN, hdr11->addr4, ETH_ALEN); /* SA */
558 break;
559 default:
560 memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
561 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
562 break;
563 }
564
565 if (ieee80211_is_data_qos(hdr11->frame_control)) {
566 hdr[12] = le16_to_cpu(*((__le16 *)ieee80211_get_qos_ctl(hdr11)))
567 & IEEE80211_QOS_CTL_TID_MASK;
568 } else
569 hdr[12] = 0; /* priority */
570
571 hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */
572}
573
574static int lib80211_michael_mic_add(struct sk_buff *skb, int hdr_len,
575 void *priv)
576{
577 struct lib80211_tkip_data *tkey = priv;
578 u8 *pos;
579
580 if (skb_tailroom(skb) < 8 || skb->len < hdr_len) {
581 printk(KERN_DEBUG "Invalid packet for Michael MIC add "
582 "(tailroom=%d hdr_len=%d skb->len=%d)\n",
583 skb_tailroom(skb), hdr_len, skb->len);
584 return -1;
585 }
586
587 michael_mic_hdr(skb, tkey->tx_hdr);
588 pos = skb_put(skb, 8);
589 if (michael_mic(tkey->tx_tfm_michael, &tkey->key[16], tkey->tx_hdr,
590 skb->data + hdr_len, skb->len - 8 - hdr_len, pos))
591 return -1;
592
593 return 0;
594}
595
596static void lib80211_michael_mic_failure(struct net_device *dev,
597 struct ieee80211_hdr *hdr,
598 int keyidx)
599{
600 union iwreq_data wrqu;
601 struct iw_michaelmicfailure ev;
602
603 /* TODO: needed parameters: count, keyid, key type, TSC */
604 memset(&ev, 0, sizeof(ev));
605 ev.flags = keyidx & IW_MICFAILURE_KEY_ID;
606 if (hdr->addr1[0] & 0x01)
607 ev.flags |= IW_MICFAILURE_GROUP;
608 else
609 ev.flags |= IW_MICFAILURE_PAIRWISE;
610 ev.src_addr.sa_family = ARPHRD_ETHER;
611 memcpy(ev.src_addr.sa_data, hdr->addr2, ETH_ALEN);
612 memset(&wrqu, 0, sizeof(wrqu));
613 wrqu.data.length = sizeof(ev);
614 wireless_send_event(dev, IWEVMICHAELMICFAILURE, &wrqu, (char *)&ev);
615}
616
617static int lib80211_michael_mic_verify(struct sk_buff *skb, int keyidx,
618 int hdr_len, void *priv)
619{
620 struct lib80211_tkip_data *tkey = priv;
621 u8 mic[8];
622
623 if (!tkey->key_set)
624 return -1;
625
626 michael_mic_hdr(skb, tkey->rx_hdr);
627 if (michael_mic(tkey->rx_tfm_michael, &tkey->key[24], tkey->rx_hdr,
628 skb->data + hdr_len, skb->len - 8 - hdr_len, mic))
629 return -1;
630 if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) {
631 struct ieee80211_hdr *hdr;
632 hdr = (struct ieee80211_hdr *)skb->data;
633 printk(KERN_DEBUG "%s: Michael MIC verification failed for "
634 "MSDU from %pM keyidx=%d\n",
635 skb->dev ? skb->dev->name : "N/A", hdr->addr2,
636 keyidx);
637 if (skb->dev)
638 lib80211_michael_mic_failure(skb->dev, hdr, keyidx);
639 tkey->dot11RSNAStatsTKIPLocalMICFailures++;
640 return -1;
641 }
642
643 /* Update TSC counters for RX now that the packet verification has
644 * completed. */
645 tkey->rx_iv32 = tkey->rx_iv32_new;
646 tkey->rx_iv16 = tkey->rx_iv16_new;
647
648 skb_trim(skb, skb->len - 8);
649
650 return 0;
651}
652
653static int lib80211_tkip_set_key(void *key, int len, u8 * seq, void *priv)
654{
655 struct lib80211_tkip_data *tkey = priv;
656 int keyidx;
657 struct crypto_ahash *tfm = tkey->tx_tfm_michael;
658 struct crypto_skcipher *tfm2 = tkey->tx_tfm_arc4;
659 struct crypto_ahash *tfm3 = tkey->rx_tfm_michael;
660 struct crypto_skcipher *tfm4 = tkey->rx_tfm_arc4;
661
662 keyidx = tkey->key_idx;
663 memset(tkey, 0, sizeof(*tkey));
664 tkey->key_idx = keyidx;
665 tkey->tx_tfm_michael = tfm;
666 tkey->tx_tfm_arc4 = tfm2;
667 tkey->rx_tfm_michael = tfm3;
668 tkey->rx_tfm_arc4 = tfm4;
669 if (len == TKIP_KEY_LEN) {
670 memcpy(tkey->key, key, TKIP_KEY_LEN);
671 tkey->key_set = 1;
672 tkey->tx_iv16 = 1; /* TSC is initialized to 1 */
673 if (seq) {
674 tkey->rx_iv32 = (seq[5] << 24) | (seq[4] << 16) |
675 (seq[3] << 8) | seq[2];
676 tkey->rx_iv16 = (seq[1] << 8) | seq[0];
677 }
678 } else if (len == 0)
679 tkey->key_set = 0;
680 else
681 return -1;
682
683 return 0;
684}
685
686static int lib80211_tkip_get_key(void *key, int len, u8 * seq, void *priv)
687{
688 struct lib80211_tkip_data *tkey = priv;
689
690 if (len < TKIP_KEY_LEN)
691 return -1;
692
693 if (!tkey->key_set)
694 return 0;
695 memcpy(key, tkey->key, TKIP_KEY_LEN);
696
697 if (seq) {
698 /* Return the sequence number of the last transmitted frame. */
699 u16 iv16 = tkey->tx_iv16;
700 u32 iv32 = tkey->tx_iv32;
701 if (iv16 == 0)
702 iv32--;
703 iv16--;
704 seq[0] = tkey->tx_iv16;
705 seq[1] = tkey->tx_iv16 >> 8;
706 seq[2] = tkey->tx_iv32;
707 seq[3] = tkey->tx_iv32 >> 8;
708 seq[4] = tkey->tx_iv32 >> 16;
709 seq[5] = tkey->tx_iv32 >> 24;
710 }
711
712 return TKIP_KEY_LEN;
713}
714
715static void lib80211_tkip_print_stats(struct seq_file *m, void *priv)
716{
717 struct lib80211_tkip_data *tkip = priv;
718 seq_printf(m,
719 "key[%d] alg=TKIP key_set=%d "
720 "tx_pn=%02x%02x%02x%02x%02x%02x "
721 "rx_pn=%02x%02x%02x%02x%02x%02x "
722 "replays=%d icv_errors=%d local_mic_failures=%d\n",
723 tkip->key_idx, tkip->key_set,
724 (tkip->tx_iv32 >> 24) & 0xff,
725 (tkip->tx_iv32 >> 16) & 0xff,
726 (tkip->tx_iv32 >> 8) & 0xff,
727 tkip->tx_iv32 & 0xff,
728 (tkip->tx_iv16 >> 8) & 0xff,
729 tkip->tx_iv16 & 0xff,
730 (tkip->rx_iv32 >> 24) & 0xff,
731 (tkip->rx_iv32 >> 16) & 0xff,
732 (tkip->rx_iv32 >> 8) & 0xff,
733 tkip->rx_iv32 & 0xff,
734 (tkip->rx_iv16 >> 8) & 0xff,
735 tkip->rx_iv16 & 0xff,
736 tkip->dot11RSNAStatsTKIPReplays,
737 tkip->dot11RSNAStatsTKIPICVErrors,
738 tkip->dot11RSNAStatsTKIPLocalMICFailures);
739}
740
741static struct lib80211_crypto_ops lib80211_crypt_tkip = {
742 .name = "TKIP",
743 .init = lib80211_tkip_init,
744 .deinit = lib80211_tkip_deinit,
745 .encrypt_mpdu = lib80211_tkip_encrypt,
746 .decrypt_mpdu = lib80211_tkip_decrypt,
747 .encrypt_msdu = lib80211_michael_mic_add,
748 .decrypt_msdu = lib80211_michael_mic_verify,
749 .set_key = lib80211_tkip_set_key,
750 .get_key = lib80211_tkip_get_key,
751 .print_stats = lib80211_tkip_print_stats,
752 .extra_mpdu_prefix_len = 4 + 4, /* IV + ExtIV */
753 .extra_mpdu_postfix_len = 4, /* ICV */
754 .extra_msdu_postfix_len = 8, /* MIC */
755 .get_flags = lib80211_tkip_get_flags,
756 .set_flags = lib80211_tkip_set_flags,
757 .owner = THIS_MODULE,
758};
759
760static int __init lib80211_crypto_tkip_init(void)
761{
762 return lib80211_register_crypto_ops(&lib80211_crypt_tkip);
763}
764
765static void __exit lib80211_crypto_tkip_exit(void)
766{
767 lib80211_unregister_crypto_ops(&lib80211_crypt_tkip);
768}
769
770module_init(lib80211_crypto_tkip_init);
771module_exit(lib80211_crypto_tkip_exit);