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
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/slab.h>
15 #include <linux/random.h>
16 #include <linux/skbuff.h>
17 #include <linux/netdevice.h>
18 #include <linux/if_ether.h>
19 #include <linux/if_arp.h>
20 #include <linux/string.h>
21 #include <linux/crypto.h>
22 #include <linux/scatterlist.h>
23 #include <linux/crc32.h>
24
25 #include "rtllib.h"
26
27 struct rtllib_tkip_data {
28 #define TKIP_KEY_LEN 32
29 u8 key[TKIP_KEY_LEN];
30 int key_set;
31
32 u32 tx_iv32;
33 u16 tx_iv16;
34 u16 tx_ttak[5];
35 int tx_phase1_done;
36
37 u32 rx_iv32;
38 u16 rx_iv16;
39 bool initialized;
40 u16 rx_ttak[5];
41 int rx_phase1_done;
42 u32 rx_iv32_new;
43 u16 rx_iv16_new;
44
45 u32 dot11RSNAStatsTKIPReplays;
46 u32 dot11RSNAStatsTKIPICVErrors;
47 u32 dot11RSNAStatsTKIPLocalMICFailures;
48
49 int key_idx;
50 struct crypto_blkcipher *rx_tfm_arc4;
51 struct crypto_hash *rx_tfm_michael;
52 struct crypto_blkcipher *tx_tfm_arc4;
53 struct crypto_hash *tx_tfm_michael;
54 /* scratch buffers for virt_to_page() (crypto API) */
55 u8 rx_hdr[16], tx_hdr[16];
56 };
57
rtllib_tkip_init(int key_idx)58 static void *rtllib_tkip_init(int key_idx)
59 {
60 struct rtllib_tkip_data *priv;
61
62 priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
63 if (priv == NULL)
64 goto fail;
65 priv->key_idx = key_idx;
66 priv->tx_tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0,
67 CRYPTO_ALG_ASYNC);
68 if (IS_ERR(priv->tx_tfm_arc4)) {
69 printk(KERN_DEBUG "rtllib_crypt_tkip: could not allocate "
70 "crypto API arc4\n");
71 priv->tx_tfm_arc4 = NULL;
72 goto fail;
73 }
74
75 priv->tx_tfm_michael = crypto_alloc_hash("michael_mic", 0,
76 CRYPTO_ALG_ASYNC);
77 if (IS_ERR(priv->tx_tfm_michael)) {
78 printk(KERN_DEBUG "rtllib_crypt_tkip: could not allocate "
79 "crypto API michael_mic\n");
80 priv->tx_tfm_michael = NULL;
81 goto fail;
82 }
83
84 priv->rx_tfm_arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0,
85 CRYPTO_ALG_ASYNC);
86 if (IS_ERR(priv->rx_tfm_arc4)) {
87 printk(KERN_DEBUG "rtllib_crypt_tkip: could not allocate "
88 "crypto API arc4\n");
89 priv->rx_tfm_arc4 = NULL;
90 goto fail;
91 }
92
93 priv->rx_tfm_michael = crypto_alloc_hash("michael_mic", 0,
94 CRYPTO_ALG_ASYNC);
95 if (IS_ERR(priv->rx_tfm_michael)) {
96 printk(KERN_DEBUG "rtllib_crypt_tkip: could not allocate "
97 "crypto API michael_mic\n");
98 priv->rx_tfm_michael = NULL;
99 goto fail;
100 }
101 return priv;
102
103 fail:
104 if (priv) {
105 if (priv->tx_tfm_michael)
106 crypto_free_hash(priv->tx_tfm_michael);
107 if (priv->tx_tfm_arc4)
108 crypto_free_blkcipher(priv->tx_tfm_arc4);
109 if (priv->rx_tfm_michael)
110 crypto_free_hash(priv->rx_tfm_michael);
111 if (priv->rx_tfm_arc4)
112 crypto_free_blkcipher(priv->rx_tfm_arc4);
113 kfree(priv);
114 }
115
116 return NULL;
117 }
118
119
rtllib_tkip_deinit(void * priv)120 static void rtllib_tkip_deinit(void *priv)
121 {
122 struct rtllib_tkip_data *_priv = priv;
123
124 if (_priv) {
125 if (_priv->tx_tfm_michael)
126 crypto_free_hash(_priv->tx_tfm_michael);
127 if (_priv->tx_tfm_arc4)
128 crypto_free_blkcipher(_priv->tx_tfm_arc4);
129 if (_priv->rx_tfm_michael)
130 crypto_free_hash(_priv->rx_tfm_michael);
131 if (_priv->rx_tfm_arc4)
132 crypto_free_blkcipher(_priv->rx_tfm_arc4);
133 }
134 kfree(priv);
135 }
136
137
RotR1(u16 val)138 static inline u16 RotR1(u16 val)
139 {
140 return (val >> 1) | (val << 15);
141 }
142
143
Lo8(u16 val)144 static inline u8 Lo8(u16 val)
145 {
146 return val & 0xff;
147 }
148
149
Hi8(u16 val)150 static inline u8 Hi8(u16 val)
151 {
152 return val >> 8;
153 }
154
155
Lo16(u32 val)156 static inline u16 Lo16(u32 val)
157 {
158 return val & 0xffff;
159 }
160
161
Hi16(u32 val)162 static inline u16 Hi16(u32 val)
163 {
164 return val >> 16;
165 }
166
167
Mk16(u8 hi,u8 lo)168 static inline u16 Mk16(u8 hi, u8 lo)
169 {
170 return lo | (((u16) hi) << 8);
171 }
172
173
Mk16_le(u16 * v)174 static inline u16 Mk16_le(u16 *v)
175 {
176 return le16_to_cpu(*v);
177 }
178
179
180 static const u16 Sbox[256] = {
181 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154,
182 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A,
183 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B,
184 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B,
185 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F,
186 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F,
187 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5,
188 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F,
189 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB,
190 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397,
191 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED,
192 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A,
193 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194,
194 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3,
195 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104,
196 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D,
197 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39,
198 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695,
199 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83,
200 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76,
201 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4,
202 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B,
203 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0,
204 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018,
205 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751,
206 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85,
207 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12,
208 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9,
209 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7,
210 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A,
211 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8,
212 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A,
213 };
214
215
_S_(u16 v)216 static inline u16 _S_(u16 v)
217 {
218 u16 t = Sbox[Hi8(v)];
219 return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8));
220 }
221
222
223 #define PHASE1_LOOP_COUNT 8
224
225
tkip_mixing_phase1(u16 * TTAK,const u8 * TK,const u8 * TA,u32 IV32)226 static void tkip_mixing_phase1(u16 *TTAK, const u8 *TK, const u8 *TA, u32 IV32)
227 {
228 int i, j;
229
230 /* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */
231 TTAK[0] = Lo16(IV32);
232 TTAK[1] = Hi16(IV32);
233 TTAK[2] = Mk16(TA[1], TA[0]);
234 TTAK[3] = Mk16(TA[3], TA[2]);
235 TTAK[4] = Mk16(TA[5], TA[4]);
236
237 for (i = 0; i < PHASE1_LOOP_COUNT; i++) {
238 j = 2 * (i & 1);
239 TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j]));
240 TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j]));
241 TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j]));
242 TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j]));
243 TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i;
244 }
245 }
246
247
tkip_mixing_phase2(u8 * WEPSeed,const u8 * TK,const u16 * TTAK,u16 IV16)248 static void tkip_mixing_phase2(u8 *WEPSeed, const u8 *TK, const u16 *TTAK,
249 u16 IV16)
250 {
251 /* Make temporary area overlap WEP seed so that the final copy can be
252 * avoided on little endian hosts. */
253 u16 *PPK = (u16 *) &WEPSeed[4];
254
255 /* Step 1 - make copy of TTAK and bring in TSC */
256 PPK[0] = TTAK[0];
257 PPK[1] = TTAK[1];
258 PPK[2] = TTAK[2];
259 PPK[3] = TTAK[3];
260 PPK[4] = TTAK[4];
261 PPK[5] = TTAK[4] + IV16;
262
263 /* Step 2 - 96-bit bijective mixing using S-box */
264 PPK[0] += _S_(PPK[5] ^ Mk16_le((u16 *) &TK[0]));
265 PPK[1] += _S_(PPK[0] ^ Mk16_le((u16 *) &TK[2]));
266 PPK[2] += _S_(PPK[1] ^ Mk16_le((u16 *) &TK[4]));
267 PPK[3] += _S_(PPK[2] ^ Mk16_le((u16 *) &TK[6]));
268 PPK[4] += _S_(PPK[3] ^ Mk16_le((u16 *) &TK[8]));
269 PPK[5] += _S_(PPK[4] ^ Mk16_le((u16 *) &TK[10]));
270
271 PPK[0] += RotR1(PPK[5] ^ Mk16_le((u16 *) &TK[12]));
272 PPK[1] += RotR1(PPK[0] ^ Mk16_le((u16 *) &TK[14]));
273 PPK[2] += RotR1(PPK[1]);
274 PPK[3] += RotR1(PPK[2]);
275 PPK[4] += RotR1(PPK[3]);
276 PPK[5] += RotR1(PPK[4]);
277
278 /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value
279 * WEPSeed[0..2] is transmitted as WEP IV */
280 WEPSeed[0] = Hi8(IV16);
281 WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F;
282 WEPSeed[2] = Lo8(IV16);
283 WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((u16 *) &TK[0])) >> 1);
284
285 #ifdef __BIG_ENDIAN
286 {
287 int i;
288 for (i = 0; i < 6; i++)
289 PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8);
290 }
291 #endif
292 }
293
294
rtllib_tkip_encrypt(struct sk_buff * skb,int hdr_len,void * priv)295 static int rtllib_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
296 {
297 struct rtllib_tkip_data *tkey = priv;
298 int len;
299 u8 *pos;
300 struct rtllib_hdr_4addr *hdr;
301 struct cb_desc *tcb_desc = (struct cb_desc *)(skb->cb +
302 MAX_DEV_ADDR_SIZE);
303 struct blkcipher_desc desc = {.tfm = tkey->tx_tfm_arc4};
304 int ret = 0;
305 u8 rc4key[16], *icv;
306 u32 crc;
307 struct scatterlist sg;
308
309 if (skb_headroom(skb) < 8 || skb_tailroom(skb) < 4 ||
310 skb->len < hdr_len)
311 return -1;
312
313 hdr = (struct rtllib_hdr_4addr *) skb->data;
314
315 if (!tcb_desc->bHwSec) {
316 if (!tkey->tx_phase1_done) {
317 tkip_mixing_phase1(tkey->tx_ttak, tkey->key, hdr->addr2,
318 tkey->tx_iv32);
319 tkey->tx_phase1_done = 1;
320 }
321 tkip_mixing_phase2(rc4key, tkey->key, tkey->tx_ttak,
322 tkey->tx_iv16);
323 } else
324 tkey->tx_phase1_done = 1;
325
326
327 len = skb->len - hdr_len;
328 pos = skb_push(skb, 8);
329 memmove(pos, pos + 8, hdr_len);
330 pos += hdr_len;
331
332 if (tcb_desc->bHwSec) {
333 *pos++ = Hi8(tkey->tx_iv16);
334 *pos++ = (Hi8(tkey->tx_iv16) | 0x20) & 0x7F;
335 *pos++ = Lo8(tkey->tx_iv16);
336 } else {
337 *pos++ = rc4key[0];
338 *pos++ = rc4key[1];
339 *pos++ = rc4key[2];
340 }
341
342 *pos++ = (tkey->key_idx << 6) | (1 << 5) /* Ext IV included */;
343 *pos++ = tkey->tx_iv32 & 0xff;
344 *pos++ = (tkey->tx_iv32 >> 8) & 0xff;
345 *pos++ = (tkey->tx_iv32 >> 16) & 0xff;
346 *pos++ = (tkey->tx_iv32 >> 24) & 0xff;
347
348 if (!tcb_desc->bHwSec) {
349 icv = skb_put(skb, 4);
350 crc = ~crc32_le(~0, pos, len);
351 icv[0] = crc;
352 icv[1] = crc >> 8;
353 icv[2] = crc >> 16;
354 icv[3] = crc >> 24;
355
356 sg_init_one(&sg, pos, len+4);
357
358
359 crypto_blkcipher_setkey(tkey->tx_tfm_arc4, rc4key, 16);
360 ret = crypto_blkcipher_encrypt(&desc, &sg, &sg, len + 4);
361 }
362
363 tkey->tx_iv16++;
364 if (tkey->tx_iv16 == 0) {
365 tkey->tx_phase1_done = 0;
366 tkey->tx_iv32++;
367 }
368
369 if (!tcb_desc->bHwSec)
370 return ret;
371 else
372 return 0;
373
374
375 }
376
rtllib_tkip_decrypt(struct sk_buff * skb,int hdr_len,void * priv)377 static int rtllib_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
378 {
379 struct rtllib_tkip_data *tkey = priv;
380 u8 keyidx, *pos;
381 u32 iv32;
382 u16 iv16;
383 struct rtllib_hdr_4addr *hdr;
384 struct cb_desc *tcb_desc = (struct cb_desc *)(skb->cb +
385 MAX_DEV_ADDR_SIZE);
386 struct blkcipher_desc desc = {.tfm = tkey->rx_tfm_arc4};
387 u8 rc4key[16];
388 u8 icv[4];
389 u32 crc;
390 struct scatterlist sg;
391 int plen;
392 if (skb->len < hdr_len + 8 + 4)
393 return -1;
394
395 hdr = (struct rtllib_hdr_4addr *) skb->data;
396 pos = skb->data + hdr_len;
397 keyidx = pos[3];
398 if (!(keyidx & (1 << 5))) {
399 if (net_ratelimit()) {
400 printk(KERN_DEBUG "TKIP: received packet without ExtIV"
401 " flag from %pM\n", hdr->addr2);
402 }
403 return -2;
404 }
405 keyidx >>= 6;
406 if (tkey->key_idx != keyidx) {
407 printk(KERN_DEBUG "TKIP: RX tkey->key_idx=%d frame "
408 "keyidx=%d priv=%p\n", tkey->key_idx, keyidx, priv);
409 return -6;
410 }
411 if (!tkey->key_set) {
412 if (net_ratelimit()) {
413 printk(KERN_DEBUG "TKIP: received packet from %pM"
414 " with keyid=%d that does not have a configured"
415 " key\n", hdr->addr2, keyidx);
416 }
417 return -3;
418 }
419 iv16 = (pos[0] << 8) | pos[2];
420 iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24);
421 pos += 8;
422
423 if (!tcb_desc->bHwSec || (skb->cb[0] == 1)) {
424 if ((iv32 < tkey->rx_iv32 ||
425 (iv32 == tkey->rx_iv32 && iv16 <= tkey->rx_iv16)) &&
426 tkey->initialized) {
427 if (net_ratelimit()) {
428 printk(KERN_DEBUG "TKIP: replay detected: STA="
429 " %pM previous TSC %08x%04x received "
430 "TSC %08x%04x\n",hdr->addr2,
431 tkey->rx_iv32, tkey->rx_iv16, iv32, iv16);
432 }
433 tkey->dot11RSNAStatsTKIPReplays++;
434 return -4;
435 }
436 tkey->initialized = true;
437
438 if (iv32 != tkey->rx_iv32 || !tkey->rx_phase1_done) {
439 tkip_mixing_phase1(tkey->rx_ttak, tkey->key,
440 hdr->addr2, iv32);
441 tkey->rx_phase1_done = 1;
442 }
443 tkip_mixing_phase2(rc4key, tkey->key, tkey->rx_ttak, iv16);
444
445 plen = skb->len - hdr_len - 12;
446
447 sg_init_one(&sg, pos, plen+4);
448
449 crypto_blkcipher_setkey(tkey->rx_tfm_arc4, rc4key, 16);
450 if (crypto_blkcipher_decrypt(&desc, &sg, &sg, plen + 4)) {
451 if (net_ratelimit()) {
452 printk(KERN_DEBUG ": TKIP: failed to decrypt "
453 "received packet from %pM\n",
454 hdr->addr2);
455 }
456 return -7;
457 }
458
459 crc = ~crc32_le(~0, pos, plen);
460 icv[0] = crc;
461 icv[1] = crc >> 8;
462 icv[2] = crc >> 16;
463 icv[3] = crc >> 24;
464
465 if (memcmp(icv, pos + plen, 4) != 0) {
466 if (iv32 != tkey->rx_iv32) {
467 /* Previously cached Phase1 result was already
468 * lost, so it needs to be recalculated for the
469 * next packet. */
470 tkey->rx_phase1_done = 0;
471 }
472 if (net_ratelimit()) {
473 printk(KERN_DEBUG "TKIP: ICV error detected: STA="
474 " %pM\n", hdr->addr2);
475 }
476 tkey->dot11RSNAStatsTKIPICVErrors++;
477 return -5;
478 }
479
480 }
481
482 /* Update real counters only after Michael MIC verification has
483 * completed */
484 tkey->rx_iv32_new = iv32;
485 tkey->rx_iv16_new = iv16;
486
487 /* Remove IV and ICV */
488 memmove(skb->data + 8, skb->data, hdr_len);
489 skb_pull(skb, 8);
490 skb_trim(skb, skb->len - 4);
491
492 return keyidx;
493 }
494
495
michael_mic(struct crypto_hash * tfm_michael,u8 * key,u8 * hdr,u8 * data,size_t data_len,u8 * mic)496 static int michael_mic(struct crypto_hash *tfm_michael, u8 *key, u8 *hdr,
497 u8 *data, size_t data_len, u8 *mic)
498 {
499 struct hash_desc desc;
500 struct scatterlist sg[2];
501
502 if (tfm_michael == NULL) {
503 printk(KERN_WARNING "michael_mic: tfm_michael == NULL\n");
504 return -1;
505 }
506 sg_init_table(sg, 2);
507 sg_set_buf(&sg[0], hdr, 16);
508 sg_set_buf(&sg[1], data, data_len);
509
510 if (crypto_hash_setkey(tfm_michael, key, 8))
511 return -1;
512
513 desc.tfm = tfm_michael;
514 desc.flags = 0;
515 return crypto_hash_digest(&desc, sg, data_len + 16, mic);
516 }
517
michael_mic_hdr(struct sk_buff * skb,u8 * hdr)518 static void michael_mic_hdr(struct sk_buff *skb, u8 *hdr)
519 {
520 struct rtllib_hdr_4addr *hdr11;
521
522 hdr11 = (struct rtllib_hdr_4addr *) skb->data;
523 switch (le16_to_cpu(hdr11->frame_ctl) &
524 (RTLLIB_FCTL_FROMDS | RTLLIB_FCTL_TODS)) {
525 case RTLLIB_FCTL_TODS:
526 memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
527 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
528 break;
529 case RTLLIB_FCTL_FROMDS:
530 memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
531 memcpy(hdr + ETH_ALEN, hdr11->addr3, ETH_ALEN); /* SA */
532 break;
533 case RTLLIB_FCTL_FROMDS | RTLLIB_FCTL_TODS:
534 memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
535 memcpy(hdr + ETH_ALEN, hdr11->addr4, ETH_ALEN); /* SA */
536 break;
537 case 0:
538 memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
539 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
540 break;
541 }
542
543 hdr[12] = 0; /* priority */
544
545 hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */
546 }
547
548
rtllib_michael_mic_add(struct sk_buff * skb,int hdr_len,void * priv)549 static int rtllib_michael_mic_add(struct sk_buff *skb, int hdr_len, void *priv)
550 {
551 struct rtllib_tkip_data *tkey = priv;
552 u8 *pos;
553 struct rtllib_hdr_4addr *hdr;
554
555 hdr = (struct rtllib_hdr_4addr *) skb->data;
556
557 if (skb_tailroom(skb) < 8 || skb->len < hdr_len) {
558 printk(KERN_DEBUG "Invalid packet for Michael MIC add "
559 "(tailroom=%d hdr_len=%d skb->len=%d)\n",
560 skb_tailroom(skb), hdr_len, skb->len);
561 return -1;
562 }
563
564 michael_mic_hdr(skb, tkey->tx_hdr);
565
566 if (RTLLIB_QOS_HAS_SEQ(le16_to_cpu(hdr->frame_ctl)))
567 tkey->tx_hdr[12] = *(skb->data + hdr_len - 2) & 0x07;
568 pos = skb_put(skb, 8);
569 if (michael_mic(tkey->tx_tfm_michael, &tkey->key[16], tkey->tx_hdr,
570 skb->data + hdr_len, skb->len - 8 - hdr_len, pos))
571 return -1;
572
573 return 0;
574 }
575
576
rtllib_michael_mic_failure(struct net_device * dev,struct rtllib_hdr_4addr * hdr,int keyidx)577 static void rtllib_michael_mic_failure(struct net_device *dev,
578 struct rtllib_hdr_4addr *hdr,
579 int keyidx)
580 {
581 union iwreq_data wrqu;
582 struct iw_michaelmicfailure ev;
583
584 /* TODO: needed parameters: count, keyid, key type, TSC */
585 memset(&ev, 0, sizeof(ev));
586 ev.flags = keyidx & IW_MICFAILURE_KEY_ID;
587 if (hdr->addr1[0] & 0x01)
588 ev.flags |= IW_MICFAILURE_GROUP;
589 else
590 ev.flags |= IW_MICFAILURE_PAIRWISE;
591 ev.src_addr.sa_family = ARPHRD_ETHER;
592 memcpy(ev.src_addr.sa_data, hdr->addr2, ETH_ALEN);
593 memset(&wrqu, 0, sizeof(wrqu));
594 wrqu.data.length = sizeof(ev);
595 wireless_send_event(dev, IWEVMICHAELMICFAILURE, &wrqu, (char *) &ev);
596 }
597
rtllib_michael_mic_verify(struct sk_buff * skb,int keyidx,int hdr_len,void * priv)598 static int rtllib_michael_mic_verify(struct sk_buff *skb, int keyidx,
599 int hdr_len, void *priv)
600 {
601 struct rtllib_tkip_data *tkey = priv;
602 u8 mic[8];
603 struct rtllib_hdr_4addr *hdr;
604
605 hdr = (struct rtllib_hdr_4addr *) skb->data;
606
607 if (!tkey->key_set)
608 return -1;
609
610 michael_mic_hdr(skb, tkey->rx_hdr);
611 if (RTLLIB_QOS_HAS_SEQ(le16_to_cpu(hdr->frame_ctl)))
612 tkey->rx_hdr[12] = *(skb->data + hdr_len - 2) & 0x07;
613
614 if (michael_mic(tkey->rx_tfm_michael, &tkey->key[24], tkey->rx_hdr,
615 skb->data + hdr_len, skb->len - 8 - hdr_len, mic))
616 return -1;
617
618 if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) {
619 struct rtllib_hdr_4addr *hdr;
620 hdr = (struct rtllib_hdr_4addr *) skb->data;
621 printk(KERN_DEBUG "%s: Michael MIC verification failed for "
622 "MSDU from %pM keyidx=%d\n",
623 skb->dev ? skb->dev->name : "N/A", hdr->addr2,
624 keyidx);
625 printk(KERN_DEBUG "%d\n",
626 memcmp(mic, skb->data + skb->len - 8, 8) != 0);
627 if (skb->dev) {
628 printk(KERN_INFO "skb->dev != NULL\n");
629 rtllib_michael_mic_failure(skb->dev, hdr, keyidx);
630 }
631 tkey->dot11RSNAStatsTKIPLocalMICFailures++;
632 return -1;
633 }
634
635 /* Update TSC counters for RX now that the packet verification has
636 * completed. */
637 tkey->rx_iv32 = tkey->rx_iv32_new;
638 tkey->rx_iv16 = tkey->rx_iv16_new;
639
640 skb_trim(skb, skb->len - 8);
641
642 return 0;
643 }
644
645
rtllib_tkip_set_key(void * key,int len,u8 * seq,void * priv)646 static int rtllib_tkip_set_key(void *key, int len, u8 *seq, void *priv)
647 {
648 struct rtllib_tkip_data *tkey = priv;
649 int keyidx;
650 struct crypto_hash *tfm = tkey->tx_tfm_michael;
651 struct crypto_blkcipher *tfm2 = tkey->tx_tfm_arc4;
652 struct crypto_hash *tfm3 = tkey->rx_tfm_michael;
653 struct crypto_blkcipher *tfm4 = tkey->rx_tfm_arc4;
654
655 keyidx = tkey->key_idx;
656 memset(tkey, 0, sizeof(*tkey));
657 tkey->key_idx = keyidx;
658 tkey->tx_tfm_michael = tfm;
659 tkey->tx_tfm_arc4 = tfm2;
660 tkey->rx_tfm_michael = tfm3;
661 tkey->rx_tfm_arc4 = tfm4;
662
663 if (len == TKIP_KEY_LEN) {
664 memcpy(tkey->key, key, TKIP_KEY_LEN);
665 tkey->key_set = 1;
666 tkey->tx_iv16 = 1; /* TSC is initialized to 1 */
667 if (seq) {
668 tkey->rx_iv32 = (seq[5] << 24) | (seq[4] << 16) |
669 (seq[3] << 8) | seq[2];
670 tkey->rx_iv16 = (seq[1] << 8) | seq[0];
671 }
672 } else if (len == 0)
673 tkey->key_set = 0;
674 else
675 return -1;
676
677 return 0;
678 }
679
680
rtllib_tkip_get_key(void * key,int len,u8 * seq,void * priv)681 static int rtllib_tkip_get_key(void *key, int len, u8 *seq, void *priv)
682 {
683 struct rtllib_tkip_data *tkey = priv;
684
685 if (len < TKIP_KEY_LEN)
686 return -1;
687
688 if (!tkey->key_set)
689 return 0;
690 memcpy(key, tkey->key, TKIP_KEY_LEN);
691
692 if (seq) {
693 /* Return the sequence number of the last transmitted frame. */
694 u16 iv16 = tkey->tx_iv16;
695 u32 iv32 = tkey->tx_iv32;
696 if (iv16 == 0)
697 iv32--;
698 iv16--;
699 seq[0] = tkey->tx_iv16;
700 seq[1] = tkey->tx_iv16 >> 8;
701 seq[2] = tkey->tx_iv32;
702 seq[3] = tkey->tx_iv32 >> 8;
703 seq[4] = tkey->tx_iv32 >> 16;
704 seq[5] = tkey->tx_iv32 >> 24;
705 }
706
707 return TKIP_KEY_LEN;
708 }
709
710
rtllib_tkip_print_stats(char * p,void * priv)711 static char *rtllib_tkip_print_stats(char *p, void *priv)
712 {
713 struct rtllib_tkip_data *tkip = priv;
714 p += sprintf(p, "key[%d] alg=TKIP key_set=%d "
715 "tx_pn=%02x%02x%02x%02x%02x%02x "
716 "rx_pn=%02x%02x%02x%02x%02x%02x "
717 "replays=%d icv_errors=%d local_mic_failures=%d\n",
718 tkip->key_idx, tkip->key_set,
719 (tkip->tx_iv32 >> 24) & 0xff,
720 (tkip->tx_iv32 >> 16) & 0xff,
721 (tkip->tx_iv32 >> 8) & 0xff,
722 tkip->tx_iv32 & 0xff,
723 (tkip->tx_iv16 >> 8) & 0xff,
724 tkip->tx_iv16 & 0xff,
725 (tkip->rx_iv32 >> 24) & 0xff,
726 (tkip->rx_iv32 >> 16) & 0xff,
727 (tkip->rx_iv32 >> 8) & 0xff,
728 tkip->rx_iv32 & 0xff,
729 (tkip->rx_iv16 >> 8) & 0xff,
730 tkip->rx_iv16 & 0xff,
731 tkip->dot11RSNAStatsTKIPReplays,
732 tkip->dot11RSNAStatsTKIPICVErrors,
733 tkip->dot11RSNAStatsTKIPLocalMICFailures);
734 return p;
735 }
736
737 static struct lib80211_crypto_ops rtllib_crypt_tkip = {
738 .name = "R-TKIP",
739 .init = rtllib_tkip_init,
740 .deinit = rtllib_tkip_deinit,
741 .encrypt_mpdu = rtllib_tkip_encrypt,
742 .decrypt_mpdu = rtllib_tkip_decrypt,
743 .encrypt_msdu = rtllib_michael_mic_add,
744 .decrypt_msdu = rtllib_michael_mic_verify,
745 .set_key = rtllib_tkip_set_key,
746 .get_key = rtllib_tkip_get_key,
747 .print_stats = rtllib_tkip_print_stats,
748 .extra_mpdu_prefix_len = 4 + 4, /* IV + ExtIV */
749 .extra_mpdu_postfix_len = 4, /* ICV */
750 .extra_msdu_postfix_len = 8, /* MIC */
751 .owner = THIS_MODULE,
752 };
753
754
rtllib_crypto_tkip_init(void)755 int __init rtllib_crypto_tkip_init(void)
756 {
757 return lib80211_register_crypto_ops(&rtllib_crypt_tkip);
758 }
759
760
rtllib_crypto_tkip_exit(void)761 void __exit rtllib_crypto_tkip_exit(void)
762 {
763 lib80211_unregister_crypto_ops(&rtllib_crypt_tkip);
764 }
765
766 module_init(rtllib_crypto_tkip_init);
767 module_exit(rtllib_crypto_tkip_exit);
768
769 MODULE_LICENSE("GPL");
770