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b453872c JG |
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 <asm/string.h> | |
23 | ||
24 | #include <net/ieee80211.h> | |
25 | ||
b453872c JG |
26 | #include <linux/crypto.h> |
27 | #include <asm/scatterlist.h> | |
28 | #include <linux/crc32.h> | |
29 | ||
30 | MODULE_AUTHOR("Jouni Malinen"); | |
31 | MODULE_DESCRIPTION("Host AP crypt: TKIP"); | |
32 | MODULE_LICENSE("GPL"); | |
33 | ||
34 | struct ieee80211_tkip_data { | |
35 | #define TKIP_KEY_LEN 32 | |
36 | u8 key[TKIP_KEY_LEN]; | |
37 | int key_set; | |
38 | ||
39 | u32 tx_iv32; | |
40 | u16 tx_iv16; | |
41 | u16 tx_ttak[5]; | |
42 | int tx_phase1_done; | |
43 | ||
44 | u32 rx_iv32; | |
45 | u16 rx_iv16; | |
46 | u16 rx_ttak[5]; | |
47 | int rx_phase1_done; | |
48 | u32 rx_iv32_new; | |
49 | u16 rx_iv16_new; | |
50 | ||
51 | u32 dot11RSNAStatsTKIPReplays; | |
52 | u32 dot11RSNAStatsTKIPICVErrors; | |
53 | u32 dot11RSNAStatsTKIPLocalMICFailures; | |
54 | ||
55 | int key_idx; | |
56 | ||
57 | struct crypto_tfm *tfm_arc4; | |
58 | struct crypto_tfm *tfm_michael; | |
59 | ||
60 | /* scratch buffers for virt_to_page() (crypto API) */ | |
61 | u8 rx_hdr[16], tx_hdr[16]; | |
20d64713 JK |
62 | |
63 | struct ieee80211_device *ieee; | |
b453872c JG |
64 | }; |
65 | ||
20d64713 | 66 | static void *ieee80211_tkip_init(struct ieee80211_device *ieee, int key_idx) |
b453872c JG |
67 | { |
68 | struct ieee80211_tkip_data *priv; | |
69 | ||
70 | priv = kmalloc(sizeof(*priv), GFP_ATOMIC); | |
71 | if (priv == NULL) | |
72 | goto fail; | |
73 | memset(priv, 0, sizeof(*priv)); | |
20d64713 JK |
74 | |
75 | priv->ieee = ieee; | |
76 | ||
b453872c JG |
77 | priv->key_idx = key_idx; |
78 | ||
79 | priv->tfm_arc4 = crypto_alloc_tfm("arc4", 0); | |
80 | if (priv->tfm_arc4 == NULL) { | |
81 | printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate " | |
82 | "crypto API arc4\n"); | |
83 | goto fail; | |
84 | } | |
85 | ||
86 | priv->tfm_michael = crypto_alloc_tfm("michael_mic", 0); | |
87 | if (priv->tfm_michael == NULL) { | |
88 | printk(KERN_DEBUG "ieee80211_crypt_tkip: could not allocate " | |
89 | "crypto API michael_mic\n"); | |
90 | goto fail; | |
91 | } | |
92 | ||
93 | return priv; | |
94 | ||
0edd5b44 | 95 | fail: |
b453872c JG |
96 | if (priv) { |
97 | if (priv->tfm_michael) | |
98 | crypto_free_tfm(priv->tfm_michael); | |
99 | if (priv->tfm_arc4) | |
100 | crypto_free_tfm(priv->tfm_arc4); | |
101 | kfree(priv); | |
102 | } | |
103 | ||
104 | return NULL; | |
105 | } | |
106 | ||
b453872c JG |
107 | static void ieee80211_tkip_deinit(void *priv) |
108 | { | |
109 | struct ieee80211_tkip_data *_priv = priv; | |
110 | if (_priv && _priv->tfm_michael) | |
111 | crypto_free_tfm(_priv->tfm_michael); | |
112 | if (_priv && _priv->tfm_arc4) | |
113 | crypto_free_tfm(_priv->tfm_arc4); | |
114 | kfree(priv); | |
115 | } | |
116 | ||
b453872c JG |
117 | static inline u16 RotR1(u16 val) |
118 | { | |
119 | return (val >> 1) | (val << 15); | |
120 | } | |
121 | ||
b453872c JG |
122 | static inline u8 Lo8(u16 val) |
123 | { | |
124 | return val & 0xff; | |
125 | } | |
126 | ||
b453872c JG |
127 | static inline u8 Hi8(u16 val) |
128 | { | |
129 | return val >> 8; | |
130 | } | |
131 | ||
b453872c JG |
132 | static inline u16 Lo16(u32 val) |
133 | { | |
134 | return val & 0xffff; | |
135 | } | |
136 | ||
b453872c JG |
137 | static inline u16 Hi16(u32 val) |
138 | { | |
139 | return val >> 16; | |
140 | } | |
141 | ||
b453872c JG |
142 | static inline u16 Mk16(u8 hi, u8 lo) |
143 | { | |
144 | return lo | (((u16) hi) << 8); | |
145 | } | |
146 | ||
0edd5b44 | 147 | static inline u16 Mk16_le(u16 * v) |
b453872c JG |
148 | { |
149 | return le16_to_cpu(*v); | |
150 | } | |
151 | ||
0edd5b44 | 152 | static const u16 Sbox[256] = { |
b453872c JG |
153 | 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154, |
154 | 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A, | |
155 | 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B, | |
156 | 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B, | |
157 | 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F, | |
158 | 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F, | |
159 | 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5, | |
160 | 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F, | |
161 | 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB, | |
162 | 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397, | |
163 | 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED, | |
164 | 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A, | |
165 | 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194, | |
166 | 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3, | |
167 | 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104, | |
168 | 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D, | |
169 | 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39, | |
170 | 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695, | |
171 | 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83, | |
172 | 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76, | |
173 | 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4, | |
174 | 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B, | |
175 | 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0, | |
176 | 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018, | |
177 | 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751, | |
178 | 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85, | |
179 | 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12, | |
180 | 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9, | |
181 | 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7, | |
182 | 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A, | |
183 | 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8, | |
184 | 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A, | |
185 | }; | |
186 | ||
b453872c JG |
187 | static inline u16 _S_(u16 v) |
188 | { | |
189 | u16 t = Sbox[Hi8(v)]; | |
190 | return Sbox[Lo8(v)] ^ ((t << 8) | (t >> 8)); | |
191 | } | |
192 | ||
b453872c JG |
193 | #define PHASE1_LOOP_COUNT 8 |
194 | ||
0edd5b44 JG |
195 | static void tkip_mixing_phase1(u16 * TTAK, const u8 * TK, const u8 * TA, |
196 | u32 IV32) | |
b453872c JG |
197 | { |
198 | int i, j; | |
199 | ||
200 | /* Initialize the 80-bit TTAK from TSC (IV32) and TA[0..5] */ | |
201 | TTAK[0] = Lo16(IV32); | |
202 | TTAK[1] = Hi16(IV32); | |
203 | TTAK[2] = Mk16(TA[1], TA[0]); | |
204 | TTAK[3] = Mk16(TA[3], TA[2]); | |
205 | TTAK[4] = Mk16(TA[5], TA[4]); | |
206 | ||
207 | for (i = 0; i < PHASE1_LOOP_COUNT; i++) { | |
208 | j = 2 * (i & 1); | |
209 | TTAK[0] += _S_(TTAK[4] ^ Mk16(TK[1 + j], TK[0 + j])); | |
210 | TTAK[1] += _S_(TTAK[0] ^ Mk16(TK[5 + j], TK[4 + j])); | |
211 | TTAK[2] += _S_(TTAK[1] ^ Mk16(TK[9 + j], TK[8 + j])); | |
212 | TTAK[3] += _S_(TTAK[2] ^ Mk16(TK[13 + j], TK[12 + j])); | |
213 | TTAK[4] += _S_(TTAK[3] ^ Mk16(TK[1 + j], TK[0 + j])) + i; | |
214 | } | |
215 | } | |
216 | ||
0edd5b44 | 217 | static void tkip_mixing_phase2(u8 * WEPSeed, const u8 * TK, const u16 * TTAK, |
b453872c JG |
218 | u16 IV16) |
219 | { | |
220 | /* Make temporary area overlap WEP seed so that the final copy can be | |
221 | * avoided on little endian hosts. */ | |
0edd5b44 | 222 | u16 *PPK = (u16 *) & WEPSeed[4]; |
b453872c JG |
223 | |
224 | /* Step 1 - make copy of TTAK and bring in TSC */ | |
225 | PPK[0] = TTAK[0]; | |
226 | PPK[1] = TTAK[1]; | |
227 | PPK[2] = TTAK[2]; | |
228 | PPK[3] = TTAK[3]; | |
229 | PPK[4] = TTAK[4]; | |
230 | PPK[5] = TTAK[4] + IV16; | |
231 | ||
232 | /* Step 2 - 96-bit bijective mixing using S-box */ | |
0edd5b44 JG |
233 | PPK[0] += _S_(PPK[5] ^ Mk16_le((u16 *) & TK[0])); |
234 | PPK[1] += _S_(PPK[0] ^ Mk16_le((u16 *) & TK[2])); | |
235 | PPK[2] += _S_(PPK[1] ^ Mk16_le((u16 *) & TK[4])); | |
236 | PPK[3] += _S_(PPK[2] ^ Mk16_le((u16 *) & TK[6])); | |
237 | PPK[4] += _S_(PPK[3] ^ Mk16_le((u16 *) & TK[8])); | |
238 | PPK[5] += _S_(PPK[4] ^ Mk16_le((u16 *) & TK[10])); | |
239 | ||
240 | PPK[0] += RotR1(PPK[5] ^ Mk16_le((u16 *) & TK[12])); | |
241 | PPK[1] += RotR1(PPK[0] ^ Mk16_le((u16 *) & TK[14])); | |
b453872c JG |
242 | PPK[2] += RotR1(PPK[1]); |
243 | PPK[3] += RotR1(PPK[2]); | |
244 | PPK[4] += RotR1(PPK[3]); | |
245 | PPK[5] += RotR1(PPK[4]); | |
246 | ||
247 | /* Step 3 - bring in last of TK bits, assign 24-bit WEP IV value | |
248 | * WEPSeed[0..2] is transmitted as WEP IV */ | |
249 | WEPSeed[0] = Hi8(IV16); | |
250 | WEPSeed[1] = (Hi8(IV16) | 0x20) & 0x7F; | |
251 | WEPSeed[2] = Lo8(IV16); | |
0edd5b44 | 252 | WEPSeed[3] = Lo8((PPK[5] ^ Mk16_le((u16 *) & TK[0])) >> 1); |
b453872c JG |
253 | |
254 | #ifdef __BIG_ENDIAN | |
255 | { | |
256 | int i; | |
257 | for (i = 0; i < 6; i++) | |
258 | PPK[i] = (PPK[i] << 8) | (PPK[i] >> 8); | |
259 | } | |
260 | #endif | |
261 | } | |
262 | ||
263 | static int ieee80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv) | |
264 | { | |
265 | struct ieee80211_tkip_data *tkey = priv; | |
266 | int len; | |
267 | u8 rc4key[16], *pos, *icv; | |
268 | struct ieee80211_hdr *hdr; | |
269 | u32 crc; | |
270 | struct scatterlist sg; | |
271 | ||
20d64713 JK |
272 | hdr = (struct ieee80211_hdr *)skb->data; |
273 | ||
274 | if (tkey->ieee->tkip_countermeasures) { | |
275 | if (net_ratelimit()) { | |
276 | printk(KERN_DEBUG "%s: TKIP countermeasures: dropped " | |
277 | "TX packet to " MAC_FMT "\n", | |
278 | tkey->ieee->dev->name, MAC_ARG(hdr->addr1)); | |
279 | } | |
280 | return -1; | |
281 | } | |
282 | ||
b453872c JG |
283 | if (skb_headroom(skb) < 8 || skb_tailroom(skb) < 4 || |
284 | skb->len < hdr_len) | |
285 | return -1; | |
286 | ||
b453872c JG |
287 | if (!tkey->tx_phase1_done) { |
288 | tkip_mixing_phase1(tkey->tx_ttak, tkey->key, hdr->addr2, | |
289 | tkey->tx_iv32); | |
290 | tkey->tx_phase1_done = 1; | |
291 | } | |
292 | tkip_mixing_phase2(rc4key, tkey->key, tkey->tx_ttak, tkey->tx_iv16); | |
293 | ||
294 | len = skb->len - hdr_len; | |
295 | pos = skb_push(skb, 8); | |
296 | memmove(pos, pos + 8, hdr_len); | |
297 | pos += hdr_len; | |
298 | icv = skb_put(skb, 4); | |
299 | ||
300 | *pos++ = rc4key[0]; | |
301 | *pos++ = rc4key[1]; | |
302 | *pos++ = rc4key[2]; | |
0edd5b44 | 303 | *pos++ = (tkey->key_idx << 6) | (1 << 5) /* Ext IV included */ ; |
b453872c JG |
304 | *pos++ = tkey->tx_iv32 & 0xff; |
305 | *pos++ = (tkey->tx_iv32 >> 8) & 0xff; | |
306 | *pos++ = (tkey->tx_iv32 >> 16) & 0xff; | |
307 | *pos++ = (tkey->tx_iv32 >> 24) & 0xff; | |
308 | ||
309 | crc = ~crc32_le(~0, pos, len); | |
310 | icv[0] = crc; | |
311 | icv[1] = crc >> 8; | |
312 | icv[2] = crc >> 16; | |
313 | icv[3] = crc >> 24; | |
314 | ||
315 | crypto_cipher_setkey(tkey->tfm_arc4, rc4key, 16); | |
316 | sg.page = virt_to_page(pos); | |
317 | sg.offset = offset_in_page(pos); | |
318 | sg.length = len + 4; | |
319 | crypto_cipher_encrypt(tkey->tfm_arc4, &sg, &sg, len + 4); | |
320 | ||
321 | tkey->tx_iv16++; | |
322 | if (tkey->tx_iv16 == 0) { | |
323 | tkey->tx_phase1_done = 0; | |
324 | tkey->tx_iv32++; | |
325 | } | |
326 | ||
327 | return 0; | |
328 | } | |
329 | ||
330 | static int ieee80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv) | |
331 | { | |
332 | struct ieee80211_tkip_data *tkey = priv; | |
333 | u8 rc4key[16]; | |
334 | u8 keyidx, *pos; | |
335 | u32 iv32; | |
336 | u16 iv16; | |
337 | struct ieee80211_hdr *hdr; | |
338 | u8 icv[4]; | |
339 | u32 crc; | |
340 | struct scatterlist sg; | |
341 | int plen; | |
342 | ||
20d64713 JK |
343 | hdr = (struct ieee80211_hdr *)skb->data; |
344 | ||
345 | if (tkey->ieee->tkip_countermeasures) { | |
346 | if (net_ratelimit()) { | |
347 | printk(KERN_DEBUG "%s: TKIP countermeasures: dropped " | |
348 | "received packet from " MAC_FMT "\n", | |
349 | tkey->ieee->dev->name, MAC_ARG(hdr->addr2)); | |
350 | } | |
351 | return -1; | |
352 | } | |
353 | ||
b453872c JG |
354 | if (skb->len < hdr_len + 8 + 4) |
355 | return -1; | |
356 | ||
b453872c JG |
357 | pos = skb->data + hdr_len; |
358 | keyidx = pos[3]; | |
359 | if (!(keyidx & (1 << 5))) { | |
360 | if (net_ratelimit()) { | |
361 | printk(KERN_DEBUG "TKIP: received packet without ExtIV" | |
362 | " flag from " MAC_FMT "\n", MAC_ARG(hdr->addr2)); | |
363 | } | |
364 | return -2; | |
365 | } | |
366 | keyidx >>= 6; | |
367 | if (tkey->key_idx != keyidx) { | |
368 | printk(KERN_DEBUG "TKIP: RX tkey->key_idx=%d frame " | |
369 | "keyidx=%d priv=%p\n", tkey->key_idx, keyidx, priv); | |
370 | return -6; | |
371 | } | |
372 | if (!tkey->key_set) { | |
373 | if (net_ratelimit()) { | |
374 | printk(KERN_DEBUG "TKIP: received packet from " MAC_FMT | |
375 | " with keyid=%d that does not have a configured" | |
376 | " key\n", MAC_ARG(hdr->addr2), keyidx); | |
377 | } | |
378 | return -3; | |
379 | } | |
380 | iv16 = (pos[0] << 8) | pos[2]; | |
381 | iv32 = pos[4] | (pos[5] << 8) | (pos[6] << 16) | (pos[7] << 24); | |
382 | pos += 8; | |
383 | ||
384 | if (iv32 < tkey->rx_iv32 || | |
385 | (iv32 == tkey->rx_iv32 && iv16 <= tkey->rx_iv16)) { | |
386 | if (net_ratelimit()) { | |
387 | printk(KERN_DEBUG "TKIP: replay detected: STA=" MAC_FMT | |
388 | " previous TSC %08x%04x received TSC " | |
389 | "%08x%04x\n", MAC_ARG(hdr->addr2), | |
390 | tkey->rx_iv32, tkey->rx_iv16, iv32, iv16); | |
391 | } | |
392 | tkey->dot11RSNAStatsTKIPReplays++; | |
393 | return -4; | |
394 | } | |
395 | ||
396 | if (iv32 != tkey->rx_iv32 || !tkey->rx_phase1_done) { | |
397 | tkip_mixing_phase1(tkey->rx_ttak, tkey->key, hdr->addr2, iv32); | |
398 | tkey->rx_phase1_done = 1; | |
399 | } | |
400 | tkip_mixing_phase2(rc4key, tkey->key, tkey->rx_ttak, iv16); | |
401 | ||
402 | plen = skb->len - hdr_len - 12; | |
403 | ||
404 | crypto_cipher_setkey(tkey->tfm_arc4, rc4key, 16); | |
405 | sg.page = virt_to_page(pos); | |
406 | sg.offset = offset_in_page(pos); | |
407 | sg.length = plen + 4; | |
408 | crypto_cipher_decrypt(tkey->tfm_arc4, &sg, &sg, plen + 4); | |
409 | ||
410 | crc = ~crc32_le(~0, pos, plen); | |
411 | icv[0] = crc; | |
412 | icv[1] = crc >> 8; | |
413 | icv[2] = crc >> 16; | |
414 | icv[3] = crc >> 24; | |
415 | if (memcmp(icv, pos + plen, 4) != 0) { | |
416 | if (iv32 != tkey->rx_iv32) { | |
417 | /* Previously cached Phase1 result was already lost, so | |
418 | * it needs to be recalculated for the next packet. */ | |
419 | tkey->rx_phase1_done = 0; | |
420 | } | |
421 | if (net_ratelimit()) { | |
422 | printk(KERN_DEBUG "TKIP: ICV error detected: STA=" | |
423 | MAC_FMT "\n", MAC_ARG(hdr->addr2)); | |
424 | } | |
425 | tkey->dot11RSNAStatsTKIPICVErrors++; | |
426 | return -5; | |
427 | } | |
428 | ||
429 | /* Update real counters only after Michael MIC verification has | |
430 | * completed */ | |
431 | tkey->rx_iv32_new = iv32; | |
432 | tkey->rx_iv16_new = iv16; | |
433 | ||
434 | /* Remove IV and ICV */ | |
435 | memmove(skb->data + 8, skb->data, hdr_len); | |
436 | skb_pull(skb, 8); | |
437 | skb_trim(skb, skb->len - 4); | |
438 | ||
439 | return keyidx; | |
440 | } | |
441 | ||
0edd5b44 JG |
442 | static int michael_mic(struct ieee80211_tkip_data *tkey, u8 * key, u8 * hdr, |
443 | u8 * data, size_t data_len, u8 * mic) | |
b453872c JG |
444 | { |
445 | struct scatterlist sg[2]; | |
446 | ||
447 | if (tkey->tfm_michael == NULL) { | |
448 | printk(KERN_WARNING "michael_mic: tfm_michael == NULL\n"); | |
449 | return -1; | |
450 | } | |
451 | sg[0].page = virt_to_page(hdr); | |
452 | sg[0].offset = offset_in_page(hdr); | |
453 | sg[0].length = 16; | |
454 | ||
455 | sg[1].page = virt_to_page(data); | |
456 | sg[1].offset = offset_in_page(data); | |
457 | sg[1].length = data_len; | |
458 | ||
459 | crypto_digest_init(tkey->tfm_michael); | |
460 | crypto_digest_setkey(tkey->tfm_michael, key, 8); | |
461 | crypto_digest_update(tkey->tfm_michael, sg, 2); | |
462 | crypto_digest_final(tkey->tfm_michael, mic); | |
463 | ||
464 | return 0; | |
465 | } | |
466 | ||
0edd5b44 | 467 | static void michael_mic_hdr(struct sk_buff *skb, u8 * hdr) |
b453872c JG |
468 | { |
469 | struct ieee80211_hdr *hdr11; | |
470 | ||
0edd5b44 | 471 | hdr11 = (struct ieee80211_hdr *)skb->data; |
b453872c JG |
472 | switch (le16_to_cpu(hdr11->frame_ctl) & |
473 | (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) { | |
474 | case IEEE80211_FCTL_TODS: | |
0edd5b44 JG |
475 | memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */ |
476 | memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */ | |
b453872c JG |
477 | break; |
478 | case IEEE80211_FCTL_FROMDS: | |
0edd5b44 JG |
479 | memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */ |
480 | memcpy(hdr + ETH_ALEN, hdr11->addr3, ETH_ALEN); /* SA */ | |
b453872c JG |
481 | break; |
482 | case IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS: | |
0edd5b44 JG |
483 | memcpy(hdr, hdr11->addr3, ETH_ALEN); /* DA */ |
484 | memcpy(hdr + ETH_ALEN, hdr11->addr4, ETH_ALEN); /* SA */ | |
b453872c JG |
485 | break; |
486 | case 0: | |
0edd5b44 JG |
487 | memcpy(hdr, hdr11->addr1, ETH_ALEN); /* DA */ |
488 | memcpy(hdr + ETH_ALEN, hdr11->addr2, ETH_ALEN); /* SA */ | |
b453872c JG |
489 | break; |
490 | } | |
491 | ||
0edd5b44 JG |
492 | hdr[12] = 0; /* priority */ |
493 | hdr[13] = hdr[14] = hdr[15] = 0; /* reserved */ | |
b453872c JG |
494 | } |
495 | ||
0edd5b44 JG |
496 | static int ieee80211_michael_mic_add(struct sk_buff *skb, int hdr_len, |
497 | void *priv) | |
b453872c JG |
498 | { |
499 | struct ieee80211_tkip_data *tkey = priv; | |
500 | u8 *pos; | |
501 | ||
502 | if (skb_tailroom(skb) < 8 || skb->len < hdr_len) { | |
503 | printk(KERN_DEBUG "Invalid packet for Michael MIC add " | |
504 | "(tailroom=%d hdr_len=%d skb->len=%d)\n", | |
505 | skb_tailroom(skb), hdr_len, skb->len); | |
506 | return -1; | |
507 | } | |
508 | ||
509 | michael_mic_hdr(skb, tkey->tx_hdr); | |
510 | pos = skb_put(skb, 8); | |
511 | if (michael_mic(tkey, &tkey->key[16], tkey->tx_hdr, | |
512 | skb->data + hdr_len, skb->len - 8 - hdr_len, pos)) | |
513 | return -1; | |
514 | ||
515 | return 0; | |
516 | } | |
517 | ||
b453872c JG |
518 | #if WIRELESS_EXT >= 18 |
519 | static void ieee80211_michael_mic_failure(struct net_device *dev, | |
0edd5b44 | 520 | struct ieee80211_hdr *hdr, int keyidx) |
b453872c JG |
521 | { |
522 | union iwreq_data wrqu; | |
523 | struct iw_michaelmicfailure ev; | |
524 | ||
525 | /* TODO: needed parameters: count, keyid, key type, TSC */ | |
526 | memset(&ev, 0, sizeof(ev)); | |
527 | ev.flags = keyidx & IW_MICFAILURE_KEY_ID; | |
528 | if (hdr->addr1[0] & 0x01) | |
529 | ev.flags |= IW_MICFAILURE_GROUP; | |
530 | else | |
531 | ev.flags |= IW_MICFAILURE_PAIRWISE; | |
532 | ev.src_addr.sa_family = ARPHRD_ETHER; | |
533 | memcpy(ev.src_addr.sa_data, hdr->addr2, ETH_ALEN); | |
534 | memset(&wrqu, 0, sizeof(wrqu)); | |
535 | wrqu.data.length = sizeof(ev); | |
0edd5b44 | 536 | wireless_send_event(dev, IWEVMICHAELMICFAILURE, &wrqu, (char *)&ev); |
b453872c JG |
537 | } |
538 | #elif WIRELESS_EXT >= 15 | |
539 | static void ieee80211_michael_mic_failure(struct net_device *dev, | |
0edd5b44 | 540 | struct ieee80211_hdr *hdr, int keyidx) |
b453872c JG |
541 | { |
542 | union iwreq_data wrqu; | |
543 | char buf[128]; | |
544 | ||
545 | /* TODO: needed parameters: count, keyid, key type, TSC */ | |
546 | sprintf(buf, "MLME-MICHAELMICFAILURE.indication(keyid=%d %scast addr=" | |
547 | MAC_FMT ")", keyidx, hdr->addr1[0] & 0x01 ? "broad" : "uni", | |
548 | MAC_ARG(hdr->addr2)); | |
549 | memset(&wrqu, 0, sizeof(wrqu)); | |
550 | wrqu.data.length = strlen(buf); | |
551 | wireless_send_event(dev, IWEVCUSTOM, &wrqu, buf); | |
552 | } | |
0edd5b44 | 553 | #else /* WIRELESS_EXT >= 15 */ |
b453872c | 554 | static inline void ieee80211_michael_mic_failure(struct net_device *dev, |
0edd5b44 JG |
555 | struct ieee80211_hdr *hdr, |
556 | int keyidx) | |
b453872c JG |
557 | { |
558 | } | |
0edd5b44 | 559 | #endif /* WIRELESS_EXT >= 15 */ |
b453872c JG |
560 | |
561 | static int ieee80211_michael_mic_verify(struct sk_buff *skb, int keyidx, | |
0edd5b44 | 562 | int hdr_len, void *priv) |
b453872c JG |
563 | { |
564 | struct ieee80211_tkip_data *tkey = priv; | |
565 | u8 mic[8]; | |
566 | ||
567 | if (!tkey->key_set) | |
568 | return -1; | |
569 | ||
570 | michael_mic_hdr(skb, tkey->rx_hdr); | |
571 | if (michael_mic(tkey, &tkey->key[24], tkey->rx_hdr, | |
572 | skb->data + hdr_len, skb->len - 8 - hdr_len, mic)) | |
573 | return -1; | |
574 | if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) { | |
575 | struct ieee80211_hdr *hdr; | |
0edd5b44 | 576 | hdr = (struct ieee80211_hdr *)skb->data; |
b453872c JG |
577 | printk(KERN_DEBUG "%s: Michael MIC verification failed for " |
578 | "MSDU from " MAC_FMT " keyidx=%d\n", | |
579 | skb->dev ? skb->dev->name : "N/A", MAC_ARG(hdr->addr2), | |
580 | keyidx); | |
581 | if (skb->dev) | |
582 | ieee80211_michael_mic_failure(skb->dev, hdr, keyidx); | |
583 | tkey->dot11RSNAStatsTKIPLocalMICFailures++; | |
584 | return -1; | |
585 | } | |
586 | ||
587 | /* Update TSC counters for RX now that the packet verification has | |
588 | * completed. */ | |
589 | tkey->rx_iv32 = tkey->rx_iv32_new; | |
590 | tkey->rx_iv16 = tkey->rx_iv16_new; | |
591 | ||
592 | skb_trim(skb, skb->len - 8); | |
593 | ||
594 | return 0; | |
595 | } | |
596 | ||
0edd5b44 | 597 | static int ieee80211_tkip_set_key(void *key, int len, u8 * seq, void *priv) |
b453872c JG |
598 | { |
599 | struct ieee80211_tkip_data *tkey = priv; | |
600 | int keyidx; | |
601 | struct crypto_tfm *tfm = tkey->tfm_michael; | |
602 | struct crypto_tfm *tfm2 = tkey->tfm_arc4; | |
603 | ||
604 | keyidx = tkey->key_idx; | |
605 | memset(tkey, 0, sizeof(*tkey)); | |
606 | tkey->key_idx = keyidx; | |
607 | tkey->tfm_michael = tfm; | |
608 | tkey->tfm_arc4 = tfm2; | |
609 | if (len == TKIP_KEY_LEN) { | |
610 | memcpy(tkey->key, key, TKIP_KEY_LEN); | |
611 | tkey->key_set = 1; | |
0edd5b44 | 612 | tkey->tx_iv16 = 1; /* TSC is initialized to 1 */ |
b453872c JG |
613 | if (seq) { |
614 | tkey->rx_iv32 = (seq[5] << 24) | (seq[4] << 16) | | |
0edd5b44 | 615 | (seq[3] << 8) | seq[2]; |
b453872c JG |
616 | tkey->rx_iv16 = (seq[1] << 8) | seq[0]; |
617 | } | |
618 | } else if (len == 0) | |
619 | tkey->key_set = 0; | |
620 | else | |
621 | return -1; | |
622 | ||
623 | return 0; | |
624 | } | |
625 | ||
0edd5b44 | 626 | static int ieee80211_tkip_get_key(void *key, int len, u8 * seq, void *priv) |
b453872c JG |
627 | { |
628 | struct ieee80211_tkip_data *tkey = priv; | |
629 | ||
630 | if (len < TKIP_KEY_LEN) | |
631 | return -1; | |
632 | ||
633 | if (!tkey->key_set) | |
634 | return 0; | |
635 | memcpy(key, tkey->key, TKIP_KEY_LEN); | |
636 | ||
637 | if (seq) { | |
638 | /* Return the sequence number of the last transmitted frame. */ | |
639 | u16 iv16 = tkey->tx_iv16; | |
640 | u32 iv32 = tkey->tx_iv32; | |
641 | if (iv16 == 0) | |
642 | iv32--; | |
643 | iv16--; | |
644 | seq[0] = tkey->tx_iv16; | |
645 | seq[1] = tkey->tx_iv16 >> 8; | |
646 | seq[2] = tkey->tx_iv32; | |
647 | seq[3] = tkey->tx_iv32 >> 8; | |
648 | seq[4] = tkey->tx_iv32 >> 16; | |
649 | seq[5] = tkey->tx_iv32 >> 24; | |
650 | } | |
651 | ||
652 | return TKIP_KEY_LEN; | |
653 | } | |
654 | ||
0edd5b44 | 655 | static char *ieee80211_tkip_print_stats(char *p, void *priv) |
b453872c JG |
656 | { |
657 | struct ieee80211_tkip_data *tkip = priv; | |
658 | p += sprintf(p, "key[%d] alg=TKIP key_set=%d " | |
659 | "tx_pn=%02x%02x%02x%02x%02x%02x " | |
660 | "rx_pn=%02x%02x%02x%02x%02x%02x " | |
661 | "replays=%d icv_errors=%d local_mic_failures=%d\n", | |
662 | tkip->key_idx, tkip->key_set, | |
663 | (tkip->tx_iv32 >> 24) & 0xff, | |
664 | (tkip->tx_iv32 >> 16) & 0xff, | |
665 | (tkip->tx_iv32 >> 8) & 0xff, | |
666 | tkip->tx_iv32 & 0xff, | |
667 | (tkip->tx_iv16 >> 8) & 0xff, | |
668 | tkip->tx_iv16 & 0xff, | |
669 | (tkip->rx_iv32 >> 24) & 0xff, | |
670 | (tkip->rx_iv32 >> 16) & 0xff, | |
671 | (tkip->rx_iv32 >> 8) & 0xff, | |
672 | tkip->rx_iv32 & 0xff, | |
673 | (tkip->rx_iv16 >> 8) & 0xff, | |
674 | tkip->rx_iv16 & 0xff, | |
675 | tkip->dot11RSNAStatsTKIPReplays, | |
676 | tkip->dot11RSNAStatsTKIPICVErrors, | |
677 | tkip->dot11RSNAStatsTKIPLocalMICFailures); | |
678 | return p; | |
679 | } | |
680 | ||
b453872c | 681 | static struct ieee80211_crypto_ops ieee80211_crypt_tkip = { |
74079fdc JK |
682 | .name = "TKIP", |
683 | .init = ieee80211_tkip_init, | |
684 | .deinit = ieee80211_tkip_deinit, | |
685 | .encrypt_mpdu = ieee80211_tkip_encrypt, | |
686 | .decrypt_mpdu = ieee80211_tkip_decrypt, | |
687 | .encrypt_msdu = ieee80211_michael_mic_add, | |
688 | .decrypt_msdu = ieee80211_michael_mic_verify, | |
689 | .set_key = ieee80211_tkip_set_key, | |
690 | .get_key = ieee80211_tkip_get_key, | |
691 | .print_stats = ieee80211_tkip_print_stats, | |
692 | .extra_prefix_len = 4 + 4, /* IV + ExtIV */ | |
693 | .extra_postfix_len = 8 + 4, /* MIC + ICV */ | |
694 | .owner = THIS_MODULE, | |
b453872c JG |
695 | }; |
696 | ||
b453872c JG |
697 | static int __init ieee80211_crypto_tkip_init(void) |
698 | { | |
699 | return ieee80211_register_crypto_ops(&ieee80211_crypt_tkip); | |
700 | } | |
701 | ||
b453872c JG |
702 | static void __exit ieee80211_crypto_tkip_exit(void) |
703 | { | |
704 | ieee80211_unregister_crypto_ops(&ieee80211_crypt_tkip); | |
705 | } | |
706 | ||
b453872c JG |
707 | module_init(ieee80211_crypto_tkip_init); |
708 | module_exit(ieee80211_crypto_tkip_exit); |