1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * lib80211 crypt: host-based TKIP encryption implementation for lib80211
4 *
5 * Copyright (c) 2003-2004, Jouni Malinen <j@w1.fi>
6 * Copyright (c) 2008, John W. Linville <linville@tuxdriver.com>
7 */
8
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11 #include <linux/err.h>
12 #include <linux/fips.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/slab.h>
16 #include <linux/random.h>
17 #include <linux/scatterlist.h>
18 #include <linux/skbuff.h>
19 #include <linux/netdevice.h>
20 #include <linux/mm.h>
21 #include <linux/if_ether.h>
22 #include <linux/if_arp.h>
23 #include <asm/string.h>
24
25 #include <linux/wireless.h>
26 #include <linux/ieee80211.h>
27 #include <net/iw_handler.h>
28
29 #include <crypto/arc4.h>
30 #include <crypto/hash.h>
31 #include <linux/crypto.h>
32 #include <linux/crc32.h>
33
34 #include <net/lib80211.h>
35
36 MODULE_AUTHOR("Jouni Malinen");
37 MODULE_DESCRIPTION("lib80211 crypt: TKIP");
38 MODULE_LICENSE("GPL");
39
40 #define TKIP_HDR_LEN 8
41
42 struct lib80211_tkip_data {
43 #define TKIP_KEY_LEN 32
44 u8 key[TKIP_KEY_LEN];
45 int key_set;
46
47 u32 tx_iv32;
48 u16 tx_iv16;
49 u16 tx_ttak[5];
50 int tx_phase1_done;
51
52 u32 rx_iv32;
53 u16 rx_iv16;
54 u16 rx_ttak[5];
55 int rx_phase1_done;
56 u32 rx_iv32_new;
57 u16 rx_iv16_new;
58
59 u32 dot11RSNAStatsTKIPReplays;
60 u32 dot11RSNAStatsTKIPICVErrors;
61 u32 dot11RSNAStatsTKIPLocalMICFailures;
62
63 int key_idx;
64
65 struct arc4_ctx rx_ctx_arc4;
66 struct arc4_ctx tx_ctx_arc4;
67 struct crypto_shash *rx_tfm_michael;
68 struct crypto_shash *tx_tfm_michael;
69
70 /* scratch buffers for virt_to_page() (crypto API) */
71 u8 rx_hdr[16], tx_hdr[16];
72
73 unsigned long flags;
74 };
75
76 static unsigned long lib80211_tkip_set_flags(unsigned long flags, void *priv)
77 {
78 struct lib80211_tkip_data *_priv = priv;
79 unsigned long old_flags = _priv->flags;
80 _priv->flags = flags;
81 return old_flags;
82 }
83
84 static unsigned long lib80211_tkip_get_flags(void *priv)
85 {
86 struct lib80211_tkip_data *_priv = priv;
87 return _priv->flags;
88 }
89
90 static void *lib80211_tkip_init(int key_idx)
91 {
92 struct lib80211_tkip_data *priv;
93
94 if (fips_enabled)
95 return NULL;
96
97 priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
98 if (priv == NULL)
99 goto fail;
100
101 priv->key_idx = key_idx;
102
103 priv->tx_tfm_michael = crypto_alloc_shash("michael_mic", 0, 0);
104 if (IS_ERR(priv->tx_tfm_michael)) {
105 priv->tx_tfm_michael = NULL;
106 goto fail;
107 }
108
109 priv->rx_tfm_michael = crypto_alloc_shash("michael_mic", 0, 0);
110 if (IS_ERR(priv->rx_tfm_michael)) {
111 priv->rx_tfm_michael = NULL;
112 goto fail;
113 }
114
115 return priv;
116
117 fail:
118 if (priv) {
119 crypto_free_shash(priv->tx_tfm_michael);
120 crypto_free_shash(priv->rx_tfm_michael);
121 kfree(priv);
122 }
123
124 return NULL;
125 }
126
127 static void lib80211_tkip_deinit(void *priv)
128 {
129 struct lib80211_tkip_data *_priv = priv;
130 if (_priv) {
131 crypto_free_shash(_priv->tx_tfm_michael);
132 crypto_free_shash(_priv->rx_tfm_michael);
133 }
134 kfree_sensitive(priv);
135 }
136
137 static inline u16 RotR1(u16 val)
138 {
139 return (val >> 1) | (val << 15);
140 }
141
142 static inline u8 Lo8(u16 val)
143 {
144 return val & 0xff;
145 }
146
147 static inline u8 Hi8(u16 val)
148 {
149 return val >> 8;
150 }
151
152 static inline u16 Lo16(u32 val)
153 {
154 return val & 0xffff;
155 }
156
157 static inline u16 Hi16(u32 val)
158 {
159 return val >> 16;
160 }
161
162 static inline u16 Mk16(u8 hi, u8 lo)
163 {
164 return lo | (((u16) hi) << 8);
165 }
166
167 static inline u16 Mk16_le(__le16 * v)
168 {
169 return le16_to_cpu(*v);
170 }
171
172 static const u16 Sbox[256] = {
173 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154,
174 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A,
175 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B,
176 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B,
177 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F,
178 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F,
179 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5,
180 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F,
181 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB,
182 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397,
183 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED,
184 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A,
185 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194,
186 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3,
187 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104,
188 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D,
189 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39,
190 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695,
191 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83,
192 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76,
193 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4,
194 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B,
195 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0,
196 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018,
197 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751,
198 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85,
199 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12,
200 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9,
201 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7,
202 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A,
203 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8,
204 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A,
205 };
206
207 static inline u16 _S_(u16 v)
208 {
209 u16 t = Sbox[Hi8(v)];
210 return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8));
211 }
212
213 #define PHASE1_LOOP_COUNT 8
214
215 static void tkip_mixing_phase1(u16 * TTAK, const u8 * TK, const u8 * TA,
216 u32 IV32)
217 {
218 int i, j;
219
220 /* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */
221 TTAK[0] = Lo16(IV32);
222 TTAK[1] = Hi16(IV32);
223 TTAK[2] = Mk16(TA[1], TA[0]);
224 TTAK[3] = Mk16(TA[3], TA[2]);
225 TTAK[4] = Mk16(TA[5], TA[4]);
226
227 for (i = 0; i < PHASE1_LOOP_COUNT; i++) {
228 j = 2 * (i & 1);
229 TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j]));
230 TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j]));
231 TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j]));
232 TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j]));
233 TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i;
234 }
235 }
236
237 static void tkip_mixing_phase2(u8 * WEPSeed, const u8 * TK, const u16 * TTAK,
238 u16 IV16)
239 {
240 /* Make temporary area overlap WEP seed so that the final copy can be
241 * avoided on little endian hosts. */
242 u16 *PPK = (u16 *) & WEPSeed[4];
243
244 /* Step 1 - make copy of TTAK and bring in TSC */
245 PPK[0] = TTAK[0];
246 PPK[1] = TTAK[1];
247 PPK[2] = TTAK[2];
248 PPK[3] = TTAK[3];
249 PPK[4] = TTAK[4];
250 PPK[5] = TTAK[4] + IV16;
251
252 /* Step 2 - 96-bit bijective mixing using S-box */
253 PPK[0] += _S_(PPK[5] ^ Mk16_le((__le16 *) & TK[0]));
254 PPK[1] += _S_(PPK[0] ^ Mk16_le((__le16 *) & TK[2]));
255 PPK[2] += _S_(PPK[1] ^ Mk16_le((__le16 *) & TK[4]));
256 PPK[3] += _S_(PPK[2] ^ Mk16_le((__le16 *) & TK[6]));
257 PPK[4] += _S_(PPK[3] ^ Mk16_le((__le16 *) & TK[8]));
258 PPK[5] += _S_(PPK[4] ^ Mk16_le((__le16 *) & TK[10]));
259
260 PPK[0] += RotR1(PPK[5] ^ Mk16_le((__le16 *) & TK[12]));
261 PPK[1] += RotR1(PPK[0] ^ Mk16_le((__le16 *) & TK[14]));
262 PPK[2] += RotR1(PPK[1]);
263 PPK[3] += RotR1(PPK[2]);
264 PPK[4] += RotR1(PPK[3]);
265 PPK[5] += RotR1(PPK[4]);
266
267 /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value
268 * WEPSeed[0..2] is transmitted as WEP IV */
269 WEPSeed[0] = Hi8(IV16);
270 WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F;
271 WEPSeed[2] = Lo8(IV16);
272 WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((__le16 *) & TK[0])) >> 1);
273
274 #ifdef __BIG_ENDIAN
275 {
276 int i;
277 for (i = 0; i < 6; i++)
278 PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8);
279 }
280 #endif
281 }
282
283 static int lib80211_tkip_hdr(struct sk_buff *skb, int hdr_len,
284 u8 * rc4key, int keylen, void *priv)
285 {
286 struct lib80211_tkip_data *tkey = priv;
287 u8 *pos;
288 struct ieee80211_hdr *hdr;
289
290 hdr = (struct ieee80211_hdr *)skb->data;
291
292 if (skb_headroom(skb) < TKIP_HDR_LEN || skb->len < hdr_len)
293 return -1;
294
295 if (rc4key == NULL || keylen < 16)
296 return -1;
297
298 if (!tkey->tx_phase1_done) {
299 tkip_mixing_phase1(tkey->tx_ttak, tkey->key, hdr->addr2,
300 tkey->tx_iv32);
301 tkey->tx_phase1_done = 1;
302 }
303 tkip_mixing_phase2(rc4key, tkey->key, tkey->tx_ttak, tkey->tx_iv16);
304
305 pos = skb_push(skb, TKIP_HDR_LEN);
306 memmove(pos, pos + TKIP_HDR_LEN, hdr_len);
307 pos += hdr_len;
308
309 *pos++ = *rc4key;
310 *pos++ = *(rc4key + 1);
311 *pos++ = *(rc4key + 2);
312 *pos++ = (tkey->key_idx << 6) | (1 << 5) /* Ext IV included */ ;
313 *pos++ = tkey->tx_iv32 & 0xff;
314 *pos++ = (tkey->tx_iv32 >> 8) & 0xff;
315 *pos++ = (tkey->tx_iv32 >> 16) & 0xff;
316 *pos++ = (tkey->tx_iv32 >> 24) & 0xff;
317
318 tkey->tx_iv16++;
319 if (tkey->tx_iv16 == 0) {
320 tkey->tx_phase1_done = 0;
321 tkey->tx_iv32++;
322 }
323
324 return TKIP_HDR_LEN;
325 }
326
327 static int lib80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
328 {
329 struct lib80211_tkip_data *tkey = priv;
330 int len;
331 u8 rc4key[16], *pos, *icv;
332 u32 crc;
333
334 if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
335 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
336 net_dbg_ratelimited("TKIP countermeasures: dropped TX packet to %pM\n",
337 hdr->addr1);
338 return -1;
339 }
340
341 if (skb_tailroom(skb) < 4 || skb->len < hdr_len)
342 return -1;
343
344 len = skb->len - hdr_len;
345 pos = skb->data + hdr_len;
346
347 if ((lib80211_tkip_hdr(skb, hdr_len, rc4key, 16, priv)) < 0)
348 return -1;
349
350 crc = ~crc32_le(~0, pos, len);
351 icv = skb_put(skb, 4);
352 icv[0] = crc;
353 icv[1] = crc >> 8;
354 icv[2] = crc >> 16;
355 icv[3] = crc >> 24;
356
357 arc4_setkey(&tkey->tx_ctx_arc4, rc4key, 16);
358 arc4_crypt(&tkey->tx_ctx_arc4, pos, pos, len + 4);
359
360 return 0;
361 }
362
363 /*
364 * deal with seq counter wrapping correctly.
365 * refer to timer_after() for jiffies wrapping handling
366 */
367 static inline int tkip_replay_check(u32 iv32_n, u16 iv16_n,
368 u32 iv32_o, u16 iv16_o)
369 {
370 if ((s32)iv32_n - (s32)iv32_o < 0 ||
371 (iv32_n == iv32_o && iv16_n <= iv16_o))
372 return 1;
373 return 0;
374 }
375
376 static int lib80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
377 {
378 struct lib80211_tkip_data *tkey = priv;
379 u8 rc4key[16];
380 u8 keyidx, *pos;
381 u32 iv32;
382 u16 iv16;
383 struct ieee80211_hdr *hdr;
384 u8 icv[4];
385 u32 crc;
386 int plen;
387
388 hdr = (struct ieee80211_hdr *)skb->data;
389
390 if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
391 net_dbg_ratelimited("TKIP countermeasures: dropped received packet from %pM\n",
392 hdr->addr2);
393 return -1;
394 }
395
396 if (skb->len < hdr_len + TKIP_HDR_LEN + 4)
397 return -1;
398
399 pos = skb->data + hdr_len;
400 keyidx = pos[3];
401 if (!(keyidx & (1 << 5))) {
402 net_dbg_ratelimited("TKIP: received packet without ExtIV flag from %pM\n",
403 hdr->addr2);
404 return -2;
405 }
406 keyidx >>= 6;
407 if (tkey->key_idx != keyidx) {
408 net_dbg_ratelimited("TKIP: RX tkey->key_idx=%d frame keyidx=%d\n",
409 tkey->key_idx, keyidx);
410 return -6;
411 }
412 if (!tkey->key_set) {
413 net_dbg_ratelimited("TKIP: received packet from %pM with keyid=%d that does not have a configured key\n",
414 hdr->addr2, keyidx);
415 return -3;
416 }
417 iv16 = (pos[0] << 8) | pos[2];
418 iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24);
419 pos += TKIP_HDR_LEN;
420
421 if (tkip_replay_check(iv32, iv16, tkey->rx_iv32, tkey->rx_iv16)) {
422 #ifdef CONFIG_LIB80211_DEBUG
423 net_dbg_ratelimited("TKIP: replay detected: STA=%pM previous TSC %08x%04x received TSC %08x%04x\n",
424 hdr->addr2, tkey->rx_iv32, tkey->rx_iv16,
425 iv32, iv16);
426 #endif
427 tkey->dot11RSNAStatsTKIPReplays++;
428 return -4;
429 }
430
431 if (iv32 != tkey->rx_iv32 || !tkey->rx_phase1_done) {
432 tkip_mixing_phase1(tkey->rx_ttak, tkey->key, hdr->addr2, iv32);
433 tkey->rx_phase1_done = 1;
434 }
435 tkip_mixing_phase2(rc4key, tkey->key, tkey->rx_ttak, iv16);
436
437 plen = skb->len - hdr_len - 12;
438
439 arc4_setkey(&tkey->rx_ctx_arc4, rc4key, 16);
440 arc4_crypt(&tkey->rx_ctx_arc4, pos, pos, plen + 4);
441
442 crc = ~crc32_le(~0, pos, plen);
443 icv[0] = crc;
444 icv[1] = crc >> 8;
445 icv[2] = crc >> 16;
446 icv[3] = crc >> 24;
447 if (memcmp(icv, pos + plen, 4) != 0) {
448 if (iv32 != tkey->rx_iv32) {
449 /* Previously cached Phase1 result was already lost, so
450 * it needs to be recalculated for the next packet. */
451 tkey->rx_phase1_done = 0;
452 }
453 #ifdef CONFIG_LIB80211_DEBUG
454 net_dbg_ratelimited("TKIP: ICV error detected: STA=%pM\n",
455 hdr->addr2);
456 #endif
457 tkey->dot11RSNAStatsTKIPICVErrors++;
458 return -5;
459 }
460
461 /* Update real counters only after Michael MIC verification has
462 * completed */
463 tkey->rx_iv32_new = iv32;
464 tkey->rx_iv16_new = iv16;
465
466 /* Remove IV and ICV */
467 memmove(skb->data + TKIP_HDR_LEN, skb->data, hdr_len);
468 skb_pull(skb, TKIP_HDR_LEN);
469 skb_trim(skb, skb->len - 4);
470
471 return keyidx;
472 }
473
474 static int michael_mic(struct crypto_shash *tfm_michael, u8 *key, u8 *hdr,
475 u8 *data, size_t data_len, u8 *mic)
476 {
477 SHASH_DESC_ON_STACK(desc, tfm_michael);
478 int err;
479
480 if (tfm_michael == NULL) {
481 pr_warn("%s(): tfm_michael == NULL\n", __func__);
482 return -1;
483 }
484
485 desc->tfm = tfm_michael;
486
487 if (crypto_shash_setkey(tfm_michael, key, 8))
488 return -1;
489
490 err = crypto_shash_init(desc);
491 if (err)
492 goto out;
493 err = crypto_shash_update(desc, hdr, 16);
494 if (err)
495 goto out;
496 err = crypto_shash_update(desc, data, data_len);
497 if (err)
498 goto out;
499 err = crypto_shash_final(desc, mic);
500
501 out:
502 shash_desc_zero(desc);
503 return err;
504 }
505
506 static void michael_mic_hdr(struct sk_buff *skb, u8 * hdr)
507 {
508 struct ieee80211_hdr *hdr11;
509
510 hdr11 = (struct ieee80211_hdr *)skb->data;
511
512 switch (le16_to_cpu(hdr11->frame_control) &
513 (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
514 case IEEE80211_FCTL_TODS:
515 memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
516 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
517 break;
518 case IEEE80211_FCTL_FROMDS:
519 memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
520 memcpy(hdr + ETH_ALEN, hdr11->addr3, ETH_ALEN); /* SA */
521 break;
522 case IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS:
523 memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */
524 memcpy(hdr + ETH_ALEN, hdr11->addr4, ETH_ALEN); /* SA */
525 break;
526 default:
527 memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */
528 memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */
529 break;
530 }
531
532 if (ieee80211_is_data_qos(hdr11->frame_control)) {
533 hdr[12] = le16_to_cpu(*((__le16 *)ieee80211_get_qos_ctl(hdr11)))
534 & IEEE80211_QOS_CTL_TID_MASK;
535 } else
536 hdr[12] = 0; /* priority */
537
538 hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */
539 }
540
541 static int lib80211_michael_mic_add(struct sk_buff *skb, int hdr_len,
542 void *priv)
543 {
544 struct lib80211_tkip_data *tkey = priv;
545 u8 *pos;
546
547 if (skb_tailroom(skb) < 8 || skb->len < hdr_len) {
548 printk(KERN_DEBUG "Invalid packet for Michael MIC add "
549 "(tailroom=%d hdr_len=%d skb->len=%d)\n",
550 skb_tailroom(skb), hdr_len, skb->len);
551 return -1;
552 }
553
554 michael_mic_hdr(skb, tkey->tx_hdr);
555 pos = skb_put(skb, 8);
556 if (michael_mic(tkey->tx_tfm_michael, &tkey->key[16], tkey->tx_hdr,
557 skb->data + hdr_len, skb->len - 8 - hdr_len, pos))
558 return -1;
559
560 return 0;
561 }
562
563 static void lib80211_michael_mic_failure(struct net_device *dev,
564 struct ieee80211_hdr *hdr,
565 int keyidx)
566 {
567 union iwreq_data wrqu;
568 struct iw_michaelmicfailure ev;
569
570 /* TODO: needed parameters: count, keyid, key type, TSC */
571 memset(&ev, 0, sizeof(ev));
572 ev.flags = keyidx & IW_MICFAILURE_KEY_ID;
573 if (hdr->addr1[0] & 0x01)
574 ev.flags |= IW_MICFAILURE_GROUP;
575 else
576 ev.flags |= IW_MICFAILURE_PAIRWISE;
577 ev.src_addr.sa_family = ARPHRD_ETHER;
578 memcpy(ev.src_addr.sa_data, hdr->addr2, ETH_ALEN);
579 memset(&wrqu, 0, sizeof(wrqu));
580 wrqu.data.length = sizeof(ev);
581 wireless_send_event(dev, IWEVMICHAELMICFAILURE, &wrqu, (char *)&ev);
582 }
583
584 static int lib80211_michael_mic_verify(struct sk_buff *skb, int keyidx,
585 int hdr_len, void *priv)
586 {
587 struct lib80211_tkip_data *tkey = priv;
588 u8 mic[8];
589
590 if (!tkey->key_set)
591 return -1;
592
593 michael_mic_hdr(skb, tkey->rx_hdr);
594 if (michael_mic(tkey->rx_tfm_michael, &tkey->key[24], tkey->rx_hdr,
595 skb->data + hdr_len, skb->len - 8 - hdr_len, mic))
596 return -1;
597 if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) {
598 struct ieee80211_hdr *hdr;
599 hdr = (struct ieee80211_hdr *)skb->data;
600 printk(KERN_DEBUG "%s: Michael MIC verification failed for "
601 "MSDU from %pM keyidx=%d\n",
602 skb->dev ? skb->dev->name : "N/A", hdr->addr2,
603 keyidx);
604 if (skb->dev)
605 lib80211_michael_mic_failure(skb->dev, hdr, keyidx);
606 tkey->dot11RSNAStatsTKIPLocalMICFailures++;
607 return -1;
608 }
609
610 /* Update TSC counters for RX now that the packet verification has
611 * completed. */
612 tkey->rx_iv32 = tkey->rx_iv32_new;
613 tkey->rx_iv16 = tkey->rx_iv16_new;
614
615 skb_trim(skb, skb->len - 8);
616
617 return 0;
618 }
619
620 static int lib80211_tkip_set_key(void *key, int len, u8 * seq, void *priv)
621 {
622 struct lib80211_tkip_data *tkey = priv;
623 int keyidx;
624 struct crypto_shash *tfm = tkey->tx_tfm_michael;
625 struct arc4_ctx *tfm2 = &tkey->tx_ctx_arc4;
626 struct crypto_shash *tfm3 = tkey->rx_tfm_michael;
627 struct arc4_ctx *tfm4 = &tkey->rx_ctx_arc4;
628
629 keyidx = tkey->key_idx;
630 memset(tkey, 0, sizeof(*tkey));
631 tkey->key_idx = keyidx;
632 tkey->tx_tfm_michael = tfm;
633 tkey->tx_ctx_arc4 = *tfm2;
634 tkey->rx_tfm_michael = tfm3;
635 tkey->rx_ctx_arc4 = *tfm4;
636 if (len == TKIP_KEY_LEN) {
637 memcpy(tkey->key, key, TKIP_KEY_LEN);
638 tkey->key_set = 1;
639 tkey->tx_iv16 = 1; /* TSC is initialized to 1 */
640 if (seq) {
641 tkey->rx_iv32 = (seq[5] << 24) | (seq[4] << 16) |
642 (seq[3] << 8) | seq[2];
643 tkey->rx_iv16 = (seq[1] << 8) | seq[0];
644 }
645 } else if (len == 0)
646 tkey->key_set = 0;
647 else
648 return -1;
649
650 return 0;
651 }
652
653 static int lib80211_tkip_get_key(void *key, int len, u8 * seq, void *priv)
654 {
655 struct lib80211_tkip_data *tkey = priv;
656
657 if (len < TKIP_KEY_LEN)
658 return -1;
659
660 if (!tkey->key_set)
661 return 0;
662 memcpy(key, tkey->key, TKIP_KEY_LEN);
663
664 if (seq) {
665 /*
666 * Not clear if this should return the value as is
667 * or - as the code previously seemed to partially
668 * have been written as - subtract one from it. It
669 * was working this way for a long time so leave it.
670 */
671 seq[0] = tkey->tx_iv16;
672 seq[1] = tkey->tx_iv16 >> 8;
673 seq[2] = tkey->tx_iv32;
674 seq[3] = tkey->tx_iv32 >> 8;
675 seq[4] = tkey->tx_iv32 >> 16;
676 seq[5] = tkey->tx_iv32 >> 24;
677 }
678
679 return TKIP_KEY_LEN;
680 }
681
682 static void lib80211_tkip_print_stats(struct seq_file *m, void *priv)
683 {
684 struct lib80211_tkip_data *tkip = priv;
685 seq_printf(m,
686 "key[%d] alg=TKIP key_set=%d "
687 "tx_pn=%02x%02x%02x%02x%02x%02x "
688 "rx_pn=%02x%02x%02x%02x%02x%02x "
689 "replays=%d icv_errors=%d local_mic_failures=%d\n",
690 tkip->key_idx, tkip->key_set,
691 (tkip->tx_iv32 >> 24) & 0xff,
692 (tkip->tx_iv32 >> 16) & 0xff,
693 (tkip->tx_iv32 >> 8) & 0xff,
694 tkip->tx_iv32 & 0xff,
695 (tkip->tx_iv16 >> 8) & 0xff,
696 tkip->tx_iv16 & 0xff,
697 (tkip->rx_iv32 >> 24) & 0xff,
698 (tkip->rx_iv32 >> 16) & 0xff,
699 (tkip->rx_iv32 >> 8) & 0xff,
700 tkip->rx_iv32 & 0xff,
701 (tkip->rx_iv16 >> 8) & 0xff,
702 tkip->rx_iv16 & 0xff,
703 tkip->dot11RSNAStatsTKIPReplays,
704 tkip->dot11RSNAStatsTKIPICVErrors,
705 tkip->dot11RSNAStatsTKIPLocalMICFailures);
706 }
707
708 static struct lib80211_crypto_ops lib80211_crypt_tkip = {
709 .name = "TKIP",
710 .init = lib80211_tkip_init,
711 .deinit = lib80211_tkip_deinit,
712 .encrypt_mpdu = lib80211_tkip_encrypt,
713 .decrypt_mpdu = lib80211_tkip_decrypt,
714 .encrypt_msdu = lib80211_michael_mic_add,
715 .decrypt_msdu = lib80211_michael_mic_verify,
716 .set_key = lib80211_tkip_set_key,
717 .get_key = lib80211_tkip_get_key,
718 .print_stats = lib80211_tkip_print_stats,
719 .extra_mpdu_prefix_len = 4 + 4, /* IV + ExtIV */
720 .extra_mpdu_postfix_len = 4, /* ICV */
721 .extra_msdu_postfix_len = 8, /* MIC */
722 .get_flags = lib80211_tkip_get_flags,
723 .set_flags = lib80211_tkip_set_flags,
724 .owner = THIS_MODULE,
725 };
726
727 static int __init lib80211_crypto_tkip_init(void)
728 {
729 return lib80211_register_crypto_ops(&lib80211_crypt_tkip);
730 }
731
732 static void __exit lib80211_crypto_tkip_exit(void)
733 {
734 lib80211_unregister_crypto_ops(&lib80211_crypt_tkip);
735 }
736
737 module_init(lib80211_crypto_tkip_init);
738 module_exit(lib80211_crypto_tkip_exit);
739
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