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