diff options
Diffstat (limited to 'drivers/net/wireless/hostap/hostap_crypt_tkip.c')
-rw-r--r-- | drivers/net/wireless/hostap/hostap_crypt_tkip.c | 696 |
1 files changed, 696 insertions, 0 deletions
diff --git a/drivers/net/wireless/hostap/hostap_crypt_tkip.c b/drivers/net/wireless/hostap/hostap_crypt_tkip.c new file mode 100644 index 000000000000..e8d56bc280aa --- /dev/null +++ b/drivers/net/wireless/hostap/hostap_crypt_tkip.c | |||
@@ -0,0 +1,696 @@ | |||
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/config.h> | ||
13 | #include <linux/version.h> | ||
14 | #include <linux/module.h> | ||
15 | #include <linux/init.h> | ||
16 | #include <linux/slab.h> | ||
17 | #include <linux/random.h> | ||
18 | #include <linux/skbuff.h> | ||
19 | #include <linux/netdevice.h> | ||
20 | #include <linux/if_ether.h> | ||
21 | #include <linux/if_arp.h> | ||
22 | #include <linux/wireless.h> | ||
23 | #include <net/iw_handler.h> | ||
24 | #include <asm/string.h> | ||
25 | |||
26 | #include "hostap_crypt.h" | ||
27 | #include "hostap_wlan.h" | ||
28 | #include "hostap_80211.h" | ||
29 | #include "hostap_config.h" | ||
30 | |||
31 | #ifndef CONFIG_CRYPTO | ||
32 | #error CONFIG_CRYPTO is required to build this module. | ||
33 | #endif | ||
34 | #include <linux/crypto.h> | ||
35 | #include <asm/scatterlist.h> | ||
36 | #include <linux/crc32.h> | ||
37 | |||
38 | MODULE_AUTHOR("Jouni Malinen"); | ||
39 | MODULE_DESCRIPTION("Host AP crypt: TKIP"); | ||
40 | MODULE_LICENSE("GPL"); | ||
41 | |||
42 | |||
43 | struct hostap_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_tfm *tfm_arc4; | ||
67 | struct crypto_tfm *tfm_michael; | ||
68 | |||
69 | /* scratch buffers for virt_to_page() (crypto API) */ | ||
70 | u8 rx_hdr[16], tx_hdr[16]; | ||
71 | }; | ||
72 | |||
73 | |||
74 | static void * hostap_tkip_init(int key_idx) | ||
75 | { | ||
76 | struct hostap_tkip_data *priv; | ||
77 | |||
78 | if (!try_module_get(THIS_MODULE)) | ||
79 | return NULL; | ||
80 | |||
81 | priv = (struct hostap_tkip_data *) kmalloc(sizeof(*priv), GFP_ATOMIC); | ||
82 | if (priv == NULL) | ||
83 | goto fail; | ||
84 | memset(priv, 0, sizeof(*priv)); | ||
85 | priv->key_idx = key_idx; | ||
86 | |||
87 | priv->tfm_arc4 = crypto_alloc_tfm("arc4", 0); | ||
88 | if (priv->tfm_arc4 == NULL) { | ||
89 | printk(KERN_DEBUG "hostap_crypt_tkip: could not allocate " | ||
90 | "crypto API arc4\n"); | ||
91 | goto fail; | ||
92 | } | ||
93 | |||
94 | priv->tfm_michael = crypto_alloc_tfm("michael_mic", 0); | ||
95 | if (priv->tfm_michael == NULL) { | ||
96 | printk(KERN_DEBUG "hostap_crypt_tkip: could not allocate " | ||
97 | "crypto API michael_mic\n"); | ||
98 | goto fail; | ||
99 | } | ||
100 | |||
101 | return priv; | ||
102 | |||
103 | fail: | ||
104 | if (priv) { | ||
105 | if (priv->tfm_michael) | ||
106 | crypto_free_tfm(priv->tfm_michael); | ||
107 | if (priv->tfm_arc4) | ||
108 | crypto_free_tfm(priv->tfm_arc4); | ||
109 | kfree(priv); | ||
110 | } | ||
111 | module_put(THIS_MODULE); | ||
112 | return NULL; | ||
113 | } | ||
114 | |||
115 | |||
116 | static void hostap_tkip_deinit(void *priv) | ||
117 | { | ||
118 | struct hostap_tkip_data *_priv = priv; | ||
119 | if (_priv && _priv->tfm_michael) | ||
120 | crypto_free_tfm(_priv->tfm_michael); | ||
121 | if (_priv && _priv->tfm_arc4) | ||
122 | crypto_free_tfm(_priv->tfm_arc4); | ||
123 | kfree(priv); | ||
124 | module_put(THIS_MODULE); | ||
125 | } | ||
126 | |||
127 | |||
128 | static inline u16 RotR1(u16 val) | ||
129 | { | ||
130 | return (val >> 1) | (val << 15); | ||
131 | } | ||
132 | |||
133 | |||
134 | static inline u8 Lo8(u16 val) | ||
135 | { | ||
136 | return val & 0xff; | ||
137 | } | ||
138 | |||
139 | |||
140 | static inline u8 Hi8(u16 val) | ||
141 | { | ||
142 | return val >> 8; | ||
143 | } | ||
144 | |||
145 | |||
146 | static inline u16 Lo16(u32 val) | ||
147 | { | ||
148 | return val & 0xffff; | ||
149 | } | ||
150 | |||
151 | |||
152 | static inline u16 Hi16(u32 val) | ||
153 | { | ||
154 | return val >> 16; | ||
155 | } | ||
156 | |||
157 | |||
158 | static inline u16 Mk16(u8 hi, u8 lo) | ||
159 | { | ||
160 | return lo | (((u16) hi) << 8); | ||
161 | } | ||
162 | |||
163 | |||
164 | static inline u16 Mk16_le(u16 *v) | ||
165 | { | ||
166 | return le16_to_cpu(*v); | ||
167 | } | ||
168 | |||
169 | |||
170 | static const u16 Sbox[256] = | ||
171 | { | ||
172 | 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154, | ||
173 | 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A, | ||
174 | 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B, | ||
175 | 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B, | ||
176 | 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F, | ||
177 | 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F, | ||
178 | 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5, | ||
179 | 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F, | ||
180 | 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB, | ||
181 | 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397, | ||
182 | 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED, | ||
183 | 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A, | ||
184 | 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194, | ||
185 | 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3, | ||
186 | 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104, | ||
187 | 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D, | ||
188 | 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39, | ||
189 | 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695, | ||
190 | 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83, | ||
191 | 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76, | ||
192 | 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4, | ||
193 | 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B, | ||
194 | 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0, | ||
195 | 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018, | ||
196 | 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751, | ||
197 | 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85, | ||
198 | 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12, | ||
199 | 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9, | ||
200 | 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7, | ||
201 | 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A, | ||
202 | 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8, | ||
203 | 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A, | ||
204 | }; | ||
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 | |||
214 | #define PHASE1_LOOP_COUNT 8 | ||
215 | |||
216 | static void tkip_mixing_phase1(u16 *TTAK, const u8 *TK, const u8 *TA, 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 | |||
238 | static void tkip_mixing_phase2(u8 *WEPSeed, const u8 *TK, const u16 *TTAK, | ||
239 | u16 IV16) | ||
240 | { | ||
241 | /* Make temporary area overlap WEP seed so that the final copy can be | ||
242 | * avoided on little endian hosts. */ | ||
243 | u16 *PPK = (u16 *) &WEPSeed[4]; | ||
244 | |||
245 | /* Step 1 - make copy of TTAK and bring in TSC */ | ||
246 | PPK[0] = TTAK[0]; | ||
247 | PPK[1] = TTAK[1]; | ||
248 | PPK[2] = TTAK[2]; | ||
249 | PPK[3] = TTAK[3]; | ||
250 | PPK[4] = TTAK[4]; | ||
251 | PPK[5] = TTAK[4] + IV16; | ||
252 | |||
253 | /* Step 2 - 96-bit bijective mixing using S-box */ | ||
254 | PPK[0] += _S_(PPK[5] ^ Mk16_le((u16 *) &TK[0])); | ||
255 | PPK[1] += _S_(PPK[0] ^ Mk16_le((u16 *) &TK[2])); | ||
256 | PPK[2] += _S_(PPK[1] ^ Mk16_le((u16 *) &TK[4])); | ||
257 | PPK[3] += _S_(PPK[2] ^ Mk16_le((u16 *) &TK[6])); | ||
258 | PPK[4] += _S_(PPK[3] ^ Mk16_le((u16 *) &TK[8])); | ||
259 | PPK[5] += _S_(PPK[4] ^ Mk16_le((u16 *) &TK[10])); | ||
260 | |||
261 | PPK[0] += RotR1(PPK[5] ^ Mk16_le((u16 *) &TK[12])); | ||
262 | PPK[1] += RotR1(PPK[0] ^ Mk16_le((u16 *) &TK[14])); | ||
263 | PPK[2] += RotR1(PPK[1]); | ||
264 | PPK[3] += RotR1(PPK[2]); | ||
265 | PPK[4] += RotR1(PPK[3]); | ||
266 | PPK[5] += RotR1(PPK[4]); | ||
267 | |||
268 | /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value | ||
269 | * WEPSeed[0..2] is transmitted as WEP IV */ | ||
270 | WEPSeed[0] = Hi8(IV16); | ||
271 | WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F; | ||
272 | WEPSeed[2] = Lo8(IV16); | ||
273 | WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((u16 *) &TK[0])) >> 1); | ||
274 | |||
275 | #ifdef __BIG_ENDIAN | ||
276 | { | ||
277 | int i; | ||
278 | for (i = 0; i < 6; i++) | ||
279 | PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8); | ||
280 | } | ||
281 | #endif | ||
282 | } | ||
283 | |||
284 | |||
285 | static int hostap_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv) | ||
286 | { | ||
287 | struct hostap_tkip_data *tkey = priv; | ||
288 | int len; | ||
289 | u8 rc4key[16], *pos, *icv; | ||
290 | struct hostap_ieee80211_hdr *hdr; | ||
291 | u32 crc; | ||
292 | struct scatterlist sg; | ||
293 | |||
294 | if (skb_headroom(skb) < 8 || skb_tailroom(skb) < 4 || | ||
295 | skb->len < hdr_len) | ||
296 | return -1; | ||
297 | |||
298 | hdr = (struct hostap_ieee80211_hdr *) skb->data; | ||
299 | if (!tkey->tx_phase1_done) { | ||
300 | tkip_mixing_phase1(tkey->tx_ttak, tkey->key, hdr->addr2, | ||
301 | tkey->tx_iv32); | ||
302 | tkey->tx_phase1_done = 1; | ||
303 | } | ||
304 | tkip_mixing_phase2(rc4key, tkey->key, tkey->tx_ttak, tkey->tx_iv16); | ||
305 | |||
306 | len = skb->len - hdr_len; | ||
307 | pos = skb_push(skb, 8); | ||
308 | memmove(pos, pos + 8, hdr_len); | ||
309 | pos += hdr_len; | ||
310 | icv = skb_put(skb, 4); | ||
311 | |||
312 | *pos++ = rc4key[0]; | ||
313 | *pos++ = rc4key[1]; | ||
314 | *pos++ = rc4key[2]; | ||
315 | *pos++ = (tkey->key_idx << 6) | (1 << 5) /* Ext IV included */; | ||
316 | *pos++ = tkey->tx_iv32 & 0xff; | ||
317 | *pos++ = (tkey->tx_iv32 >> 8) & 0xff; | ||
318 | *pos++ = (tkey->tx_iv32 >> 16) & 0xff; | ||
319 | *pos++ = (tkey->tx_iv32 >> 24) & 0xff; | ||
320 | |||
321 | crc = ~crc32_le(~0, pos, len); | ||
322 | icv[0] = crc; | ||
323 | icv[1] = crc >> 8; | ||
324 | icv[2] = crc >> 16; | ||
325 | icv[3] = crc >> 24; | ||
326 | |||
327 | crypto_cipher_setkey(tkey->tfm_arc4, rc4key, 16); | ||
328 | sg.page = virt_to_page(pos); | ||
329 | sg.offset = offset_in_page(pos); | ||
330 | sg.length = len + 4; | ||
331 | crypto_cipher_encrypt(tkey->tfm_arc4, &sg, &sg, len + 4); | ||
332 | |||
333 | tkey->tx_iv16++; | ||
334 | if (tkey->tx_iv16 == 0) { | ||
335 | tkey->tx_phase1_done = 0; | ||
336 | tkey->tx_iv32++; | ||
337 | } | ||
338 | |||
339 | return 0; | ||
340 | } | ||
341 | |||
342 | |||
343 | static int hostap_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv) | ||
344 | { | ||
345 | struct hostap_tkip_data *tkey = priv; | ||
346 | u8 rc4key[16]; | ||
347 | u8 keyidx, *pos, icv[4]; | ||
348 | u32 iv32; | ||
349 | u16 iv16; | ||
350 | struct hostap_ieee80211_hdr *hdr; | ||
351 | u32 crc; | ||
352 | struct scatterlist sg; | ||
353 | int plen; | ||
354 | |||
355 | if (skb->len < hdr_len + 8 + 4) | ||
356 | return -1; | ||
357 | |||
358 | hdr = (struct hostap_ieee80211_hdr *) skb->data; | ||
359 | pos = skb->data + hdr_len; | ||
360 | keyidx = pos[3]; | ||
361 | if (!(keyidx & (1 << 5))) { | ||
362 | if (net_ratelimit()) { | ||
363 | printk(KERN_DEBUG "TKIP: received packet without ExtIV" | ||
364 | " flag from " MACSTR "\n", MAC2STR(hdr->addr2)); | ||
365 | } | ||
366 | return -2; | ||
367 | } | ||
368 | keyidx >>= 6; | ||
369 | if (tkey->key_idx != keyidx) { | ||
370 | printk(KERN_DEBUG "TKIP: RX tkey->key_idx=%d frame " | ||
371 | "keyidx=%d priv=%p\n", tkey->key_idx, keyidx, priv); | ||
372 | return -6; | ||
373 | } | ||
374 | if (!tkey->key_set) { | ||
375 | if (net_ratelimit()) { | ||
376 | printk(KERN_DEBUG "TKIP: received packet from " MACSTR | ||
377 | " with keyid=%d that does not have a configured" | ||
378 | " key\n", MAC2STR(hdr->addr2), keyidx); | ||
379 | } | ||
380 | return -3; | ||
381 | } | ||
382 | iv16 = (pos[0] << 8) | pos[2]; | ||
383 | iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24); | ||
384 | pos += 8; | ||
385 | |||
386 | if (iv32 < tkey->rx_iv32 || | ||
387 | (iv32 == tkey->rx_iv32 && iv16 <= tkey->rx_iv16)) { | ||
388 | if (net_ratelimit()) { | ||
389 | printk(KERN_DEBUG "TKIP: replay detected: STA=" MACSTR | ||
390 | " previous TSC %08x%04x received TSC " | ||
391 | "%08x%04x\n", MAC2STR(hdr->addr2), | ||
392 | tkey->rx_iv32, tkey->rx_iv16, iv32, iv16); | ||
393 | } | ||
394 | tkey->dot11RSNAStatsTKIPReplays++; | ||
395 | return -4; | ||
396 | } | ||
397 | |||
398 | if (iv32 != tkey->rx_iv32 || !tkey->rx_phase1_done) { | ||
399 | tkip_mixing_phase1(tkey->rx_ttak, tkey->key, hdr->addr2, iv32); | ||
400 | tkey->rx_phase1_done = 1; | ||
401 | } | ||
402 | tkip_mixing_phase2(rc4key, tkey->key, tkey->rx_ttak, iv16); | ||
403 | |||
404 | plen = skb->len - hdr_len - 12; | ||
405 | |||
406 | crypto_cipher_setkey(tkey->tfm_arc4, rc4key, 16); | ||
407 | sg.page = virt_to_page(pos); | ||
408 | sg.offset = offset_in_page(pos); | ||
409 | sg.length = plen + 4; | ||
410 | crypto_cipher_decrypt(tkey->tfm_arc4, &sg, &sg, plen + 4); | ||
411 | |||
412 | crc = ~crc32_le(~0, pos, plen); | ||
413 | icv[0] = crc; | ||
414 | icv[1] = crc >> 8; | ||
415 | icv[2] = crc >> 16; | ||
416 | icv[3] = crc >> 24; | ||
417 | if (memcmp(icv, pos + plen, 4) != 0) { | ||
418 | if (iv32 != tkey->rx_iv32) { | ||
419 | /* Previously cached Phase1 result was already lost, so | ||
420 | * it needs to be recalculated for the next packet. */ | ||
421 | tkey->rx_phase1_done = 0; | ||
422 | } | ||
423 | if (net_ratelimit()) { | ||
424 | printk(KERN_DEBUG "TKIP: ICV error detected: STA=" | ||
425 | MACSTR "\n", MAC2STR(hdr->addr2)); | ||
426 | } | ||
427 | tkey->dot11RSNAStatsTKIPICVErrors++; | ||
428 | return -5; | ||
429 | } | ||
430 | |||
431 | /* Update real counters only after Michael MIC verification has | ||
432 | * completed */ | ||
433 | tkey->rx_iv32_new = iv32; | ||
434 | tkey->rx_iv16_new = iv16; | ||
435 | |||
436 | /* Remove IV and ICV */ | ||
437 | memmove(skb->data + 8, skb->data, hdr_len); | ||
438 | skb_pull(skb, 8); | ||
439 | skb_trim(skb, skb->len - 4); | ||
440 | |||
441 | return keyidx; | ||
442 | } | ||
443 | |||
444 | |||
445 | static int michael_mic(struct hostap_tkip_data *tkey, u8 *key, u8 *hdr, | ||
446 | u8 *data, size_t data_len, u8 *mic) | ||
447 | { | ||
448 | struct scatterlist sg[2]; | ||
449 | |||
450 | if (tkey->tfm_michael == NULL) { | ||
451 | printk(KERN_WARNING "michael_mic: tfm_michael == NULL\n"); | ||
452 | return -1; | ||
453 | } | ||
454 | sg[0].page = virt_to_page(hdr); | ||
455 | sg[0].offset = offset_in_page(hdr); | ||
456 | sg[0].length = 16; | ||
457 | |||
458 | sg[1].page = virt_to_page(data); | ||
459 | sg[1].offset = offset_in_page(data); | ||
460 | sg[1].length = data_len; | ||
461 | |||
462 | crypto_digest_init(tkey->tfm_michael); | ||
463 | crypto_digest_setkey(tkey->tfm_michael, key, 8); | ||
464 | crypto_digest_update(tkey->tfm_michael, sg, 2); | ||
465 | crypto_digest_final(tkey->tfm_michael, mic); | ||
466 | |||
467 | return 0; | ||
468 | } | ||
469 | |||
470 | |||
471 | static void michael_mic_hdr(struct sk_buff *skb, u8 *hdr) | ||
472 | { | ||
473 | struct hostap_ieee80211_hdr *hdr11; | ||
474 | |||
475 | hdr11 = (struct hostap_ieee80211_hdr *) skb->data; | ||
476 | switch (le16_to_cpu(hdr11->frame_control) & | ||
477 | (WLAN_FC_FROMDS | WLAN_FC_TODS)) { | ||
478 | case WLAN_FC_TODS: | ||
479 | memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */ | ||
480 | memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */ | ||
481 | break; | ||
482 | case WLAN_FC_FROMDS: | ||
483 | memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */ | ||
484 | memcpy(hdr + ETH_ALEN, hdr11->addr3, ETH_ALEN); /* SA */ | ||
485 | break; | ||
486 | case WLAN_FC_FROMDS | WLAN_FC_TODS: | ||
487 | memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */ | ||
488 | memcpy(hdr + ETH_ALEN, hdr11->addr4, ETH_ALEN); /* SA */ | ||
489 | break; | ||
490 | case 0: | ||
491 | memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */ | ||
492 | memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */ | ||
493 | break; | ||
494 | } | ||
495 | |||
496 | hdr[12] = 0; /* priority */ | ||
497 | hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */ | ||
498 | } | ||
499 | |||
500 | |||
501 | static int hostap_michael_mic_add(struct sk_buff *skb, int hdr_len, void *priv) | ||
502 | { | ||
503 | struct hostap_tkip_data *tkey = priv; | ||
504 | u8 *pos; | ||
505 | |||
506 | if (skb_tailroom(skb) < 8 || skb->len < hdr_len) { | ||
507 | printk(KERN_DEBUG "Invalid packet for Michael MIC add " | ||
508 | "(tailroom=%d hdr_len=%d skb->len=%d)\n", | ||
509 | skb_tailroom(skb), hdr_len, skb->len); | ||
510 | return -1; | ||
511 | } | ||
512 | |||
513 | michael_mic_hdr(skb, tkey->tx_hdr); | ||
514 | pos = skb_put(skb, 8); | ||
515 | if (michael_mic(tkey, &tkey->key[16], tkey->tx_hdr, | ||
516 | skb->data + hdr_len, skb->len - 8 - hdr_len, pos)) | ||
517 | return -1; | ||
518 | |||
519 | return 0; | ||
520 | } | ||
521 | |||
522 | |||
523 | static void hostap_michael_mic_failure(struct net_device *dev, | ||
524 | struct hostap_ieee80211_hdr *hdr, | ||
525 | int keyidx) | ||
526 | { | ||
527 | union iwreq_data wrqu; | ||
528 | char buf[128]; | ||
529 | |||
530 | /* TODO: needed parameters: count, keyid, key type, src address, TSC */ | ||
531 | sprintf(buf, "MLME-MICHAELMICFAILURE.indication(keyid=%d %scast addr=" | ||
532 | MACSTR ")", keyidx, hdr->addr1[0] & 0x01 ? "broad" : "uni", | ||
533 | MAC2STR(hdr->addr2)); | ||
534 | memset(&wrqu, 0, sizeof(wrqu)); | ||
535 | wrqu.data.length = strlen(buf); | ||
536 | wireless_send_event(dev, IWEVCUSTOM, &wrqu, buf); | ||
537 | } | ||
538 | |||
539 | |||
540 | static int hostap_michael_mic_verify(struct sk_buff *skb, int keyidx, | ||
541 | int hdr_len, void *priv) | ||
542 | { | ||
543 | struct hostap_tkip_data *tkey = priv; | ||
544 | u8 mic[8]; | ||
545 | |||
546 | if (!tkey->key_set) | ||
547 | return -1; | ||
548 | |||
549 | michael_mic_hdr(skb, tkey->rx_hdr); | ||
550 | if (michael_mic(tkey, &tkey->key[24], tkey->rx_hdr, | ||
551 | skb->data + hdr_len, skb->len - 8 - hdr_len, mic)) | ||
552 | return -1; | ||
553 | if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) { | ||
554 | struct hostap_ieee80211_hdr *hdr; | ||
555 | hdr = (struct hostap_ieee80211_hdr *) skb->data; | ||
556 | printk(KERN_DEBUG "%s: Michael MIC verification failed for " | ||
557 | "MSDU from " MACSTR " keyidx=%d\n", | ||
558 | skb->dev ? skb->dev->name : "N/A", MAC2STR(hdr->addr2), | ||
559 | keyidx); | ||
560 | if (skb->dev) | ||
561 | hostap_michael_mic_failure(skb->dev, hdr, keyidx); | ||
562 | tkey->dot11RSNAStatsTKIPLocalMICFailures++; | ||
563 | return -1; | ||
564 | } | ||
565 | |||
566 | /* Update TSC counters for RX now that the packet verification has | ||
567 | * completed. */ | ||
568 | tkey->rx_iv32 = tkey->rx_iv32_new; | ||
569 | tkey->rx_iv16 = tkey->rx_iv16_new; | ||
570 | |||
571 | skb_trim(skb, skb->len - 8); | ||
572 | |||
573 | return 0; | ||
574 | } | ||
575 | |||
576 | |||
577 | static int hostap_tkip_set_key(void *key, int len, u8 *seq, void *priv) | ||
578 | { | ||
579 | struct hostap_tkip_data *tkey = priv; | ||
580 | int keyidx; | ||
581 | struct crypto_tfm *tfm = tkey->tfm_michael; | ||
582 | struct crypto_tfm *tfm2 = tkey->tfm_arc4; | ||
583 | |||
584 | keyidx = tkey->key_idx; | ||
585 | memset(tkey, 0, sizeof(*tkey)); | ||
586 | tkey->key_idx = keyidx; | ||
587 | tkey->tfm_michael = tfm; | ||
588 | tkey->tfm_arc4 = tfm2; | ||
589 | if (len == TKIP_KEY_LEN) { | ||
590 | memcpy(tkey->key, key, TKIP_KEY_LEN); | ||
591 | tkey->key_set = 1; | ||
592 | tkey->tx_iv16 = 1; /* TSC is initialized to 1 */ | ||
593 | if (seq) { | ||
594 | tkey->rx_iv32 = (seq[5] << 24) | (seq[4] << 16) | | ||
595 | (seq[3] << 8) | seq[2]; | ||
596 | tkey->rx_iv16 = (seq[1] << 8) | seq[0]; | ||
597 | } | ||
598 | } else if (len == 0) { | ||
599 | tkey->key_set = 0; | ||
600 | } else | ||
601 | return -1; | ||
602 | |||
603 | return 0; | ||
604 | } | ||
605 | |||
606 | |||
607 | static int hostap_tkip_get_key(void *key, int len, u8 *seq, void *priv) | ||
608 | { | ||
609 | struct hostap_tkip_data *tkey = priv; | ||
610 | |||
611 | if (len < TKIP_KEY_LEN) | ||
612 | return -1; | ||
613 | |||
614 | if (!tkey->key_set) | ||
615 | return 0; | ||
616 | memcpy(key, tkey->key, TKIP_KEY_LEN); | ||
617 | |||
618 | if (seq) { | ||
619 | /* Return the sequence number of the last transmitted frame. */ | ||
620 | u16 iv16 = tkey->tx_iv16; | ||
621 | u32 iv32 = tkey->tx_iv32; | ||
622 | if (iv16 == 0) | ||
623 | iv32--; | ||
624 | iv16--; | ||
625 | seq[0] = tkey->tx_iv16; | ||
626 | seq[1] = tkey->tx_iv16 >> 8; | ||
627 | seq[2] = tkey->tx_iv32; | ||
628 | seq[3] = tkey->tx_iv32 >> 8; | ||
629 | seq[4] = tkey->tx_iv32 >> 16; | ||
630 | seq[5] = tkey->tx_iv32 >> 24; | ||
631 | } | ||
632 | |||
633 | return TKIP_KEY_LEN; | ||
634 | } | ||
635 | |||
636 | |||
637 | static char * hostap_tkip_print_stats(char *p, void *priv) | ||
638 | { | ||
639 | struct hostap_tkip_data *tkip = priv; | ||
640 | p += sprintf(p, "key[%d] alg=TKIP key_set=%d " | ||
641 | "tx_pn=%02x%02x%02x%02x%02x%02x " | ||
642 | "rx_pn=%02x%02x%02x%02x%02x%02x " | ||
643 | "replays=%d icv_errors=%d local_mic_failures=%d\n", | ||
644 | tkip->key_idx, tkip->key_set, | ||
645 | (tkip->tx_iv32 >> 24) & 0xff, | ||
646 | (tkip->tx_iv32 >> 16) & 0xff, | ||
647 | (tkip->tx_iv32 >> 8) & 0xff, | ||
648 | tkip->tx_iv32 & 0xff, | ||
649 | (tkip->tx_iv16 >> 8) & 0xff, | ||
650 | tkip->tx_iv16 & 0xff, | ||
651 | (tkip->rx_iv32 >> 24) & 0xff, | ||
652 | (tkip->rx_iv32 >> 16) & 0xff, | ||
653 | (tkip->rx_iv32 >> 8) & 0xff, | ||
654 | tkip->rx_iv32 & 0xff, | ||
655 | (tkip->rx_iv16 >> 8) & 0xff, | ||
656 | tkip->rx_iv16 & 0xff, | ||
657 | tkip->dot11RSNAStatsTKIPReplays, | ||
658 | tkip->dot11RSNAStatsTKIPICVErrors, | ||
659 | tkip->dot11RSNAStatsTKIPLocalMICFailures); | ||
660 | return p; | ||
661 | } | ||
662 | |||
663 | |||
664 | static struct hostap_crypto_ops hostap_crypt_tkip = { | ||
665 | .name = "TKIP", | ||
666 | .init = hostap_tkip_init, | ||
667 | .deinit = hostap_tkip_deinit, | ||
668 | .encrypt_mpdu = hostap_tkip_encrypt, | ||
669 | .decrypt_mpdu = hostap_tkip_decrypt, | ||
670 | .encrypt_msdu = hostap_michael_mic_add, | ||
671 | .decrypt_msdu = hostap_michael_mic_verify, | ||
672 | .set_key = hostap_tkip_set_key, | ||
673 | .get_key = hostap_tkip_get_key, | ||
674 | .print_stats = hostap_tkip_print_stats, | ||
675 | .extra_prefix_len = 4 + 4 /* IV + ExtIV */, | ||
676 | .extra_postfix_len = 8 + 4 /* MIC + ICV */ | ||
677 | }; | ||
678 | |||
679 | |||
680 | static int __init hostap_crypto_tkip_init(void) | ||
681 | { | ||
682 | if (hostap_register_crypto_ops(&hostap_crypt_tkip) < 0) | ||
683 | return -1; | ||
684 | |||
685 | return 0; | ||
686 | } | ||
687 | |||
688 | |||
689 | static void __exit hostap_crypto_tkip_exit(void) | ||
690 | { | ||
691 | hostap_unregister_crypto_ops(&hostap_crypt_tkip); | ||
692 | } | ||
693 | |||
694 | |||
695 | module_init(hostap_crypto_tkip_init); | ||
696 | module_exit(hostap_crypto_tkip_exit); | ||