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(size: 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(alg_name: "michael_mic" , type: 0, mask: 0); |
104 | if (IS_ERR(ptr: priv->tx_tfm_michael)) { |
105 | priv->tx_tfm_michael = NULL; |
106 | goto fail; |
107 | } |
108 | |
109 | priv->rx_tfm_michael = crypto_alloc_shash(alg_name: "michael_mic" , type: 0, mask: 0); |
110 | if (IS_ERR(ptr: 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(tfm: priv->tx_tfm_michael); |
120 | crypto_free_shash(tfm: priv->rx_tfm_michael); |
121 | kfree(objp: 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(tfm: _priv->tx_tfm_michael); |
132 | crypto_free_shash(tfm: _priv->rx_tfm_michael); |
133 | } |
134 | kfree_sensitive(objp: 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(val: v)]; |
210 | return Sbox[Lo8(val: 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(val: IV32); |
222 | TTAK[1] = Hi16(val: IV32); |
223 | TTAK[2] = Mk16(hi: TA[1], lo: TA[0]); |
224 | TTAK[3] = Mk16(hi: TA[3], lo: TA[2]); |
225 | TTAK[4] = Mk16(hi: TA[5], lo: TA[4]); |
226 | |
227 | for (i = 0; i < PHASE1_LOOP_COUNT; i++) { |
228 | j = 2 * (i & 1); |
229 | TTAK[0] += _S_(v: TTAK[4] ^ Mk16(hi: TK[1 + j], lo: TK[0 + j])); |
230 | TTAK[1] += _S_(v: TTAK[0] ^ Mk16(hi: TK[5 + j], lo: TK[4 + j])); |
231 | TTAK[2] += _S_(v: TTAK[1] ^ Mk16(hi: TK[9 + j], lo: TK[8 + j])); |
232 | TTAK[3] += _S_(v: TTAK[2] ^ Mk16(hi: TK[13 + j], lo: TK[12 + j])); |
233 | TTAK[4] += _S_(v: TTAK[3] ^ Mk16(hi: TK[1 + j], lo: 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_(v: PPK[5] ^ Mk16_le(v: (__le16 *) & TK[0])); |
254 | PPK[1] += _S_(v: PPK[0] ^ Mk16_le(v: (__le16 *) & TK[2])); |
255 | PPK[2] += _S_(v: PPK[1] ^ Mk16_le(v: (__le16 *) & TK[4])); |
256 | PPK[3] += _S_(v: PPK[2] ^ Mk16_le(v: (__le16 *) & TK[6])); |
257 | PPK[4] += _S_(v: PPK[3] ^ Mk16_le(v: (__le16 *) & TK[8])); |
258 | PPK[5] += _S_(v: PPK[4] ^ Mk16_le(v: (__le16 *) & TK[10])); |
259 | |
260 | PPK[0] += RotR1(val: PPK[5] ^ Mk16_le(v: (__le16 *) & TK[12])); |
261 | PPK[1] += RotR1(val: PPK[0] ^ Mk16_le(v: (__le16 *) & TK[14])); |
262 | PPK[2] += RotR1(val: PPK[1]); |
263 | PPK[3] += RotR1(val: PPK[2]); |
264 | PPK[4] += RotR1(val: PPK[3]); |
265 | PPK[5] += RotR1(val: 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(val: IV16); |
270 | WEPSeed[1] = (Hi8(val: IV16) | 0x20) & 0x7F; |
271 | WEPSeed[2] = Lo8(val: IV16); |
272 | WEPSeed[3] = Lo8(val: (PPK[5] ^ Mk16_le(v: (__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(TTAK: tkey->tx_ttak, TK: tkey->key, TA: hdr->addr2, |
300 | IV32: tkey->tx_iv32); |
301 | tkey->tx_phase1_done = 1; |
302 | } |
303 | tkip_mixing_phase2(WEPSeed: rc4key, TK: tkey->key, TTAK: tkey->tx_ttak, IV16: 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, keylen: 16, priv)) < 0) |
348 | return -1; |
349 | |
350 | crc = ~crc32_le(crc: ~0, p: pos, len); |
351 | icv = skb_put(skb, len: 4); |
352 | icv[0] = crc; |
353 | icv[1] = crc >> 8; |
354 | icv[2] = crc >> 16; |
355 | icv[3] = crc >> 24; |
356 | |
357 | arc4_setkey(ctx: &tkey->tx_ctx_arc4, in_key: rc4key, key_len: 16); |
358 | arc4_crypt(ctx: &tkey->tx_ctx_arc4, out: pos, in: pos, len: 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_n: iv32, iv16_n: iv16, iv32_o: tkey->rx_iv32, iv16_o: 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(TTAK: tkey->rx_ttak, TK: tkey->key, TA: hdr->addr2, IV32: iv32); |
433 | tkey->rx_phase1_done = 1; |
434 | } |
435 | tkip_mixing_phase2(WEPSeed: rc4key, TK: tkey->key, TTAK: tkey->rx_ttak, IV16: iv16); |
436 | |
437 | plen = skb->len - hdr_len - 12; |
438 | |
439 | arc4_setkey(ctx: &tkey->rx_ctx_arc4, in_key: rc4key, key_len: 16); |
440 | arc4_crypt(ctx: &tkey->rx_ctx_arc4, out: pos, in: pos, len: plen + 4); |
441 | |
442 | crc = ~crc32_le(crc: ~0, p: pos, len: plen); |
443 | icv[0] = crc; |
444 | icv[1] = crc >> 8; |
445 | icv[2] = crc >> 16; |
446 | icv[3] = crc >> 24; |
447 | if (memcmp(p: icv, q: pos + plen, size: 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, len: 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: tfm_michael, key, keylen: 8)) |
488 | return -1; |
489 | |
490 | err = crypto_shash_init(desc); |
491 | if (err) |
492 | goto out; |
493 | err = crypto_shash_update(desc, data: hdr, len: 16); |
494 | if (err) |
495 | goto out; |
496 | err = crypto_shash_update(desc, data, len: data_len); |
497 | if (err) |
498 | goto out; |
499 | err = crypto_shash_final(desc, out: 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(fc: 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, hdr: tkey->tx_hdr); |
555 | pos = skb_put(skb, len: 8); |
556 | if (michael_mic(tfm_michael: tkey->tx_tfm_michael, key: &tkey->key[16], hdr: tkey->tx_hdr, |
557 | data: skb->data + hdr_len, data_len: skb->len - 8 - hdr_len, mic: 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: &wrqu, extra: (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, hdr: tkey->rx_hdr); |
594 | if (michael_mic(tfm_michael: tkey->rx_tfm_michael, key: &tkey->key[24], hdr: tkey->rx_hdr, |
595 | data: skb->data + hdr_len, data_len: skb->len - 8 - hdr_len, mic)) |
596 | return -1; |
597 | if (memcmp(p: mic, q: skb->data + skb->len - 8, size: 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(dev: 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, len: 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 | fmt: "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(ops: &lib80211_crypt_tkip); |
730 | } |
731 | |
732 | static void __exit lib80211_crypto_tkip_exit(void) |
733 | { |
734 | lib80211_unregister_crypto_ops(ops: &lib80211_crypt_tkip); |
735 | } |
736 | |
737 | module_init(lib80211_crypto_tkip_init); |
738 | module_exit(lib80211_crypto_tkip_exit); |
739 | |