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1 | /* |
2 | * Copyright 2002-2004, Instant802 Networks, Inc. |
3 | * Copyright 2008, Jouni Malinen <j@w1.fi> |
4 | * |
5 | * This program is free software; you can redistribute it and/or modify |
6 | * it under the terms of the GNU General Public License version 2 as |
7 | * published by the Free Software Foundation. |
8 | */ |
9 | |
10 | #include <linux/netdevice.h> |
11 | #include <linux/types.h> |
12 | #include <linux/skbuff.h> |
13 | #include <linux/compiler.h> |
14 | #include <linux/ieee80211.h> |
15 | #include <linux/gfp.h> |
16 | #include <asm/unaligned.h> |
17 | #include <net/mac80211.h> |
18 | |
19 | #include "ieee80211_i.h" |
20 | #include "michael.h" |
21 | #include "tkip.h" |
22 | #include "aes_ccm.h" |
23 | #include "aes_cmac.h" |
24 | #include "wpa.h" |
25 | |
26 | ieee80211_tx_result |
27 | ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx) |
28 | { |
29 | u8 *data, *key, *mic, key_offset; |
30 | size_t data_len; |
31 | unsigned int hdrlen; |
32 | struct ieee80211_hdr *hdr; |
33 | struct sk_buff *skb = tx->skb; |
34 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
35 | int authenticator; |
36 | int tail; |
37 | |
38 | hdr = (struct ieee80211_hdr *)skb->data; |
39 | if (!tx->key || tx->key->conf.alg != ALG_TKIP || skb->len < 24 || |
40 | !ieee80211_is_data_present(hdr->frame_control)) |
41 | return TX_CONTINUE; |
42 | |
43 | hdrlen = ieee80211_hdrlen(hdr->frame_control); |
44 | if (skb->len < hdrlen) |
45 | return TX_DROP; |
46 | |
47 | data = skb->data + hdrlen; |
48 | data_len = skb->len - hdrlen; |
49 | |
50 | if (info->control.hw_key && |
51 | !(tx->flags & IEEE80211_TX_FRAGMENTED) && |
52 | !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) { |
53 | /* hwaccel - with no need for SW-generated MMIC */ |
54 | return TX_CONTINUE; |
55 | } |
56 | |
57 | tail = MICHAEL_MIC_LEN; |
58 | if (!info->control.hw_key) |
59 | tail += TKIP_ICV_LEN; |
60 | |
61 | if (WARN_ON(skb_tailroom(skb) < tail || |
62 | skb_headroom(skb) < TKIP_IV_LEN)) |
63 | return TX_DROP; |
64 | |
65 | #if 0 |
66 | authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */ |
67 | #else |
68 | authenticator = 1; |
69 | #endif |
70 | key_offset = authenticator ? |
71 | NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY : |
72 | NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY; |
73 | key = &tx->key->conf.key[key_offset]; |
74 | mic = skb_put(skb, MICHAEL_MIC_LEN); |
75 | michael_mic(key, hdr, data, data_len, mic); |
76 | |
77 | return TX_CONTINUE; |
78 | } |
79 | |
80 | |
81 | ieee80211_rx_result |
82 | ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx) |
83 | { |
84 | u8 *data, *key = NULL, key_offset; |
85 | size_t data_len; |
86 | unsigned int hdrlen; |
87 | u8 mic[MICHAEL_MIC_LEN]; |
88 | struct sk_buff *skb = rx->skb; |
89 | struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); |
90 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; |
91 | int authenticator = 1, wpa_test = 0; |
92 | |
93 | /* No way to verify the MIC if the hardware stripped it */ |
94 | if (status->flag & RX_FLAG_MMIC_STRIPPED) |
95 | return RX_CONTINUE; |
96 | |
97 | if (!rx->key || rx->key->conf.alg != ALG_TKIP || |
98 | !ieee80211_has_protected(hdr->frame_control) || |
99 | !ieee80211_is_data_present(hdr->frame_control)) |
100 | return RX_CONTINUE; |
101 | |
102 | hdrlen = ieee80211_hdrlen(hdr->frame_control); |
103 | if (skb->len < hdrlen + MICHAEL_MIC_LEN) |
104 | return RX_DROP_UNUSABLE; |
105 | |
106 | data = skb->data + hdrlen; |
107 | data_len = skb->len - hdrlen - MICHAEL_MIC_LEN; |
108 | |
109 | #if 0 |
110 | authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */ |
111 | #else |
112 | authenticator = 1; |
113 | #endif |
114 | key_offset = authenticator ? |
115 | NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY : |
116 | NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY; |
117 | key = &rx->key->conf.key[key_offset]; |
118 | michael_mic(key, hdr, data, data_len, mic); |
119 | if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) { |
120 | if (!(rx->flags & IEEE80211_RX_RA_MATCH)) |
121 | return RX_DROP_UNUSABLE; |
122 | |
123 | mac80211_ev_michael_mic_failure(rx->sdata, rx->key->conf.keyidx, |
124 | (void *) skb->data, NULL, |
125 | GFP_ATOMIC); |
126 | return RX_DROP_UNUSABLE; |
127 | } |
128 | |
129 | /* remove Michael MIC from payload */ |
130 | skb_trim(skb, skb->len - MICHAEL_MIC_LEN); |
131 | |
132 | /* update IV in key information to be able to detect replays */ |
133 | rx->key->u.tkip.rx[rx->queue].iv32 = rx->tkip_iv32; |
134 | rx->key->u.tkip.rx[rx->queue].iv16 = rx->tkip_iv16; |
135 | |
136 | return RX_CONTINUE; |
137 | } |
138 | |
139 | |
140 | static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) |
141 | { |
142 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; |
143 | struct ieee80211_key *key = tx->key; |
144 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
145 | unsigned int hdrlen; |
146 | int len, tail; |
147 | u8 *pos; |
148 | |
149 | if (info->control.hw_key && |
150 | !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV)) { |
151 | /* hwaccel - with no need for software-generated IV */ |
152 | return 0; |
153 | } |
154 | |
155 | hdrlen = ieee80211_hdrlen(hdr->frame_control); |
156 | len = skb->len - hdrlen; |
157 | |
158 | if (info->control.hw_key) |
159 | tail = 0; |
160 | else |
161 | tail = TKIP_ICV_LEN; |
162 | |
163 | if (WARN_ON(skb_tailroom(skb) < tail || |
164 | skb_headroom(skb) < TKIP_IV_LEN)) |
165 | return -1; |
166 | |
167 | pos = skb_push(skb, TKIP_IV_LEN); |
168 | memmove(pos, pos + TKIP_IV_LEN, hdrlen); |
169 | pos += hdrlen; |
170 | |
171 | /* Increase IV for the frame */ |
172 | key->u.tkip.tx.iv16++; |
173 | if (key->u.tkip.tx.iv16 == 0) |
174 | key->u.tkip.tx.iv32++; |
175 | |
176 | pos = ieee80211_tkip_add_iv(pos, key, key->u.tkip.tx.iv16); |
177 | |
178 | /* hwaccel - with software IV */ |
179 | if (info->control.hw_key) |
180 | return 0; |
181 | |
182 | /* Add room for ICV */ |
183 | skb_put(skb, TKIP_ICV_LEN); |
184 | |
185 | hdr = (struct ieee80211_hdr *) skb->data; |
186 | ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm, |
187 | key, pos, len, hdr->addr2); |
188 | return 0; |
189 | } |
190 | |
191 | |
192 | ieee80211_tx_result |
193 | ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx) |
194 | { |
195 | struct sk_buff *skb = tx->skb; |
196 | |
197 | ieee80211_tx_set_protected(tx); |
198 | |
199 | do { |
200 | if (tkip_encrypt_skb(tx, skb) < 0) |
201 | return TX_DROP; |
202 | } while ((skb = skb->next)); |
203 | |
204 | return TX_CONTINUE; |
205 | } |
206 | |
207 | |
208 | ieee80211_rx_result |
209 | ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx) |
210 | { |
211 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; |
212 | int hdrlen, res, hwaccel = 0, wpa_test = 0; |
213 | struct ieee80211_key *key = rx->key; |
214 | struct sk_buff *skb = rx->skb; |
215 | struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); |
216 | |
217 | hdrlen = ieee80211_hdrlen(hdr->frame_control); |
218 | |
219 | if (!ieee80211_is_data(hdr->frame_control)) |
220 | return RX_CONTINUE; |
221 | |
222 | if (!rx->sta || skb->len - hdrlen < 12) |
223 | return RX_DROP_UNUSABLE; |
224 | |
225 | if (status->flag & RX_FLAG_DECRYPTED) { |
226 | if (status->flag & RX_FLAG_IV_STRIPPED) { |
227 | /* |
228 | * Hardware took care of all processing, including |
229 | * replay protection, and stripped the ICV/IV so |
230 | * we cannot do any checks here. |
231 | */ |
232 | return RX_CONTINUE; |
233 | } |
234 | |
235 | /* let TKIP code verify IV, but skip decryption */ |
236 | hwaccel = 1; |
237 | } |
238 | |
239 | res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm, |
240 | key, skb->data + hdrlen, |
241 | skb->len - hdrlen, rx->sta->sta.addr, |
242 | hdr->addr1, hwaccel, rx->queue, |
243 | &rx->tkip_iv32, |
244 | &rx->tkip_iv16); |
245 | if (res != TKIP_DECRYPT_OK || wpa_test) |
246 | return RX_DROP_UNUSABLE; |
247 | |
248 | /* Trim ICV */ |
249 | skb_trim(skb, skb->len - TKIP_ICV_LEN); |
250 | |
251 | /* Remove IV */ |
252 | memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen); |
253 | skb_pull(skb, TKIP_IV_LEN); |
254 | |
255 | return RX_CONTINUE; |
256 | } |
257 | |
258 | |
259 | static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch, |
260 | int encrypted) |
261 | { |
262 | __le16 mask_fc; |
263 | int a4_included, mgmt; |
264 | u8 qos_tid; |
265 | u8 *b_0, *aad; |
266 | u16 data_len, len_a; |
267 | unsigned int hdrlen; |
268 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; |
269 | |
270 | b_0 = scratch + 3 * AES_BLOCK_LEN; |
271 | aad = scratch + 4 * AES_BLOCK_LEN; |
272 | |
273 | /* |
274 | * Mask FC: zero subtype b4 b5 b6 (if not mgmt) |
275 | * Retry, PwrMgt, MoreData; set Protected |
276 | */ |
277 | mgmt = ieee80211_is_mgmt(hdr->frame_control); |
278 | mask_fc = hdr->frame_control; |
279 | mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | |
280 | IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA); |
281 | if (!mgmt) |
282 | mask_fc &= ~cpu_to_le16(0x0070); |
283 | mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); |
284 | |
285 | hdrlen = ieee80211_hdrlen(hdr->frame_control); |
286 | len_a = hdrlen - 2; |
287 | a4_included = ieee80211_has_a4(hdr->frame_control); |
288 | |
289 | if (ieee80211_is_data_qos(hdr->frame_control)) |
290 | qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK; |
291 | else |
292 | qos_tid = 0; |
293 | |
294 | data_len = skb->len - hdrlen - CCMP_HDR_LEN; |
295 | if (encrypted) |
296 | data_len -= CCMP_MIC_LEN; |
297 | |
298 | /* First block, b_0 */ |
299 | b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */ |
300 | /* Nonce: Nonce Flags | A2 | PN |
301 | * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7) |
302 | */ |
303 | b_0[1] = qos_tid | (mgmt << 4); |
304 | memcpy(&b_0[2], hdr->addr2, ETH_ALEN); |
305 | memcpy(&b_0[8], pn, CCMP_PN_LEN); |
306 | /* l(m) */ |
307 | put_unaligned_be16(data_len, &b_0[14]); |
308 | |
309 | /* AAD (extra authenticate-only data) / masked 802.11 header |
310 | * FC | A1 | A2 | A3 | SC | [A4] | [QC] */ |
311 | put_unaligned_be16(len_a, &aad[0]); |
312 | put_unaligned(mask_fc, (__le16 *)&aad[2]); |
313 | memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN); |
314 | |
315 | /* Mask Seq#, leave Frag# */ |
316 | aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f; |
317 | aad[23] = 0; |
318 | |
319 | if (a4_included) { |
320 | memcpy(&aad[24], hdr->addr4, ETH_ALEN); |
321 | aad[30] = qos_tid; |
322 | aad[31] = 0; |
323 | } else { |
324 | memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN); |
325 | aad[24] = qos_tid; |
326 | } |
327 | } |
328 | |
329 | |
330 | static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id) |
331 | { |
332 | hdr[0] = pn[5]; |
333 | hdr[1] = pn[4]; |
334 | hdr[2] = 0; |
335 | hdr[3] = 0x20 | (key_id << 6); |
336 | hdr[4] = pn[3]; |
337 | hdr[5] = pn[2]; |
338 | hdr[6] = pn[1]; |
339 | hdr[7] = pn[0]; |
340 | } |
341 | |
342 | |
343 | static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr) |
344 | { |
345 | pn[0] = hdr[7]; |
346 | pn[1] = hdr[6]; |
347 | pn[2] = hdr[5]; |
348 | pn[3] = hdr[4]; |
349 | pn[4] = hdr[1]; |
350 | pn[5] = hdr[0]; |
351 | } |
352 | |
353 | |
354 | static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) |
355 | { |
356 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; |
357 | struct ieee80211_key *key = tx->key; |
358 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
359 | int hdrlen, len, tail; |
360 | u8 *pos, *pn; |
361 | int i; |
362 | |
363 | if (info->control.hw_key && |
364 | !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV)) { |
365 | /* |
366 | * hwaccel has no need for preallocated room for CCMP |
367 | * header or MIC fields |
368 | */ |
369 | return 0; |
370 | } |
371 | |
372 | hdrlen = ieee80211_hdrlen(hdr->frame_control); |
373 | len = skb->len - hdrlen; |
374 | |
375 | if (info->control.hw_key) |
376 | tail = 0; |
377 | else |
378 | tail = CCMP_MIC_LEN; |
379 | |
380 | if (WARN_ON(skb_tailroom(skb) < tail || |
381 | skb_headroom(skb) < CCMP_HDR_LEN)) |
382 | return -1; |
383 | |
384 | pos = skb_push(skb, CCMP_HDR_LEN); |
385 | memmove(pos, pos + CCMP_HDR_LEN, hdrlen); |
386 | hdr = (struct ieee80211_hdr *) pos; |
387 | pos += hdrlen; |
388 | |
389 | /* PN = PN + 1 */ |
390 | pn = key->u.ccmp.tx_pn; |
391 | |
392 | for (i = CCMP_PN_LEN - 1; i >= 0; i--) { |
393 | pn[i]++; |
394 | if (pn[i]) |
395 | break; |
396 | } |
397 | |
398 | ccmp_pn2hdr(pos, pn, key->conf.keyidx); |
399 | |
400 | /* hwaccel - with software CCMP header */ |
401 | if (info->control.hw_key) |
402 | return 0; |
403 | |
404 | pos += CCMP_HDR_LEN; |
405 | ccmp_special_blocks(skb, pn, key->u.ccmp.tx_crypto_buf, 0); |
406 | ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, key->u.ccmp.tx_crypto_buf, pos, len, |
407 | pos, skb_put(skb, CCMP_MIC_LEN)); |
408 | |
409 | return 0; |
410 | } |
411 | |
412 | |
413 | ieee80211_tx_result |
414 | ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx) |
415 | { |
416 | struct sk_buff *skb = tx->skb; |
417 | |
418 | ieee80211_tx_set_protected(tx); |
419 | |
420 | do { |
421 | if (ccmp_encrypt_skb(tx, skb) < 0) |
422 | return TX_DROP; |
423 | } while ((skb = skb->next)); |
424 | |
425 | return TX_CONTINUE; |
426 | } |
427 | |
428 | |
429 | ieee80211_rx_result |
430 | ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx) |
431 | { |
432 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data; |
433 | int hdrlen; |
434 | struct ieee80211_key *key = rx->key; |
435 | struct sk_buff *skb = rx->skb; |
436 | struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); |
437 | u8 pn[CCMP_PN_LEN]; |
438 | int data_len; |
439 | |
440 | hdrlen = ieee80211_hdrlen(hdr->frame_control); |
441 | |
442 | if (!ieee80211_is_data(hdr->frame_control) && |
443 | !ieee80211_is_robust_mgmt_frame(hdr)) |
444 | return RX_CONTINUE; |
445 | |
446 | data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN; |
447 | if (!rx->sta || data_len < 0) |
448 | return RX_DROP_UNUSABLE; |
449 | |
450 | if ((status->flag & RX_FLAG_DECRYPTED) && |
451 | (status->flag & RX_FLAG_IV_STRIPPED)) |
452 | return RX_CONTINUE; |
453 | |
454 | ccmp_hdr2pn(pn, skb->data + hdrlen); |
455 | |
456 | if (memcmp(pn, key->u.ccmp.rx_pn[rx->queue], CCMP_PN_LEN) <= 0) { |
457 | key->u.ccmp.replays++; |
458 | return RX_DROP_UNUSABLE; |
459 | } |
460 | |
461 | if (!(status->flag & RX_FLAG_DECRYPTED)) { |
462 | /* hardware didn't decrypt/verify MIC */ |
463 | ccmp_special_blocks(skb, pn, key->u.ccmp.rx_crypto_buf, 1); |
464 | |
465 | if (ieee80211_aes_ccm_decrypt( |
466 | key->u.ccmp.tfm, key->u.ccmp.rx_crypto_buf, |
467 | skb->data + hdrlen + CCMP_HDR_LEN, data_len, |
468 | skb->data + skb->len - CCMP_MIC_LEN, |
469 | skb->data + hdrlen + CCMP_HDR_LEN)) |
470 | return RX_DROP_UNUSABLE; |
471 | } |
472 | |
473 | memcpy(key->u.ccmp.rx_pn[rx->queue], pn, CCMP_PN_LEN); |
474 | |
475 | /* Remove CCMP header and MIC */ |
476 | skb_trim(skb, skb->len - CCMP_MIC_LEN); |
477 | memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen); |
478 | skb_pull(skb, CCMP_HDR_LEN); |
479 | |
480 | return RX_CONTINUE; |
481 | } |
482 | |
483 | |
484 | static void bip_aad(struct sk_buff *skb, u8 *aad) |
485 | { |
486 | /* BIP AAD: FC(masked) || A1 || A2 || A3 */ |
487 | |
488 | /* FC type/subtype */ |
489 | aad[0] = skb->data[0]; |
490 | /* Mask FC Retry, PwrMgt, MoreData flags to zero */ |
491 | aad[1] = skb->data[1] & ~(BIT(4) | BIT(5) | BIT(6)); |
492 | /* A1 || A2 || A3 */ |
493 | memcpy(aad + 2, skb->data + 4, 3 * ETH_ALEN); |
494 | } |
495 | |
496 | |
497 | static inline void bip_ipn_swap(u8 *d, const u8 *s) |
498 | { |
499 | *d++ = s[5]; |
500 | *d++ = s[4]; |
501 | *d++ = s[3]; |
502 | *d++ = s[2]; |
503 | *d++ = s[1]; |
504 | *d = s[0]; |
505 | } |
506 | |
507 | |
508 | ieee80211_tx_result |
509 | ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx) |
510 | { |
511 | struct sk_buff *skb = tx->skb; |
512 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
513 | struct ieee80211_key *key = tx->key; |
514 | struct ieee80211_mmie *mmie; |
515 | u8 *pn, aad[20]; |
516 | int i; |
517 | |
518 | if (info->control.hw_key) |
519 | return 0; |
520 | |
521 | if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie))) |
522 | return TX_DROP; |
523 | |
524 | mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie)); |
525 | mmie->element_id = WLAN_EID_MMIE; |
526 | mmie->length = sizeof(*mmie) - 2; |
527 | mmie->key_id = cpu_to_le16(key->conf.keyidx); |
528 | |
529 | /* PN = PN + 1 */ |
530 | pn = key->u.aes_cmac.tx_pn; |
531 | |
532 | for (i = sizeof(key->u.aes_cmac.tx_pn) - 1; i >= 0; i--) { |
533 | pn[i]++; |
534 | if (pn[i]) |
535 | break; |
536 | } |
537 | bip_ipn_swap(mmie->sequence_number, pn); |
538 | |
539 | bip_aad(skb, aad); |
540 | |
541 | /* |
542 | * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64) |
543 | */ |
544 | ieee80211_aes_cmac(key->u.aes_cmac.tfm, key->u.aes_cmac.tx_crypto_buf, |
545 | aad, skb->data + 24, skb->len - 24, mmie->mic); |
546 | |
547 | return TX_CONTINUE; |
548 | } |
549 | |
550 | |
551 | ieee80211_rx_result |
552 | ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx) |
553 | { |
554 | struct sk_buff *skb = rx->skb; |
555 | struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); |
556 | struct ieee80211_key *key = rx->key; |
557 | struct ieee80211_mmie *mmie; |
558 | u8 aad[20], mic[8], ipn[6]; |
559 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; |
560 | |
561 | if (!ieee80211_is_mgmt(hdr->frame_control)) |
562 | return RX_CONTINUE; |
563 | |
564 | if ((status->flag & RX_FLAG_DECRYPTED) && |
565 | (status->flag & RX_FLAG_IV_STRIPPED)) |
566 | return RX_CONTINUE; |
567 | |
568 | if (skb->len < 24 + sizeof(*mmie)) |
569 | return RX_DROP_UNUSABLE; |
570 | |
571 | mmie = (struct ieee80211_mmie *) |
572 | (skb->data + skb->len - sizeof(*mmie)); |
573 | if (mmie->element_id != WLAN_EID_MMIE || |
574 | mmie->length != sizeof(*mmie) - 2) |
575 | return RX_DROP_UNUSABLE; /* Invalid MMIE */ |
576 | |
577 | bip_ipn_swap(ipn, mmie->sequence_number); |
578 | |
579 | if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) { |
580 | key->u.aes_cmac.replays++; |
581 | return RX_DROP_UNUSABLE; |
582 | } |
583 | |
584 | if (!(status->flag & RX_FLAG_DECRYPTED)) { |
585 | /* hardware didn't decrypt/verify MIC */ |
586 | bip_aad(skb, aad); |
587 | ieee80211_aes_cmac(key->u.aes_cmac.tfm, |
588 | key->u.aes_cmac.rx_crypto_buf, aad, |
589 | skb->data + 24, skb->len - 24, mic); |
590 | if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) { |
591 | key->u.aes_cmac.icverrors++; |
592 | return RX_DROP_UNUSABLE; |
593 | } |
594 | } |
595 | |
596 | memcpy(key->u.aes_cmac.rx_pn, ipn, 6); |
597 | |
598 | /* Remove MMIE */ |
599 | skb_trim(skb, skb->len - sizeof(*mmie)); |
600 | |
601 | return RX_CONTINUE; |
602 | } |
603 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9