Commit | Line | Data |
---|---|---|
f0706e82 JB |
1 | /* |
2 | * Copyright 2002-2004, Instant802 Networks, Inc. | |
765cb46a | 3 | * Copyright 2008, Jouni Malinen <j@w1.fi> |
f0706e82 JB |
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/slab.h> | |
13 | #include <linux/skbuff.h> | |
14 | #include <linux/compiler.h> | |
f14df804 HH |
15 | #include <linux/ieee80211.h> |
16 | #include <asm/unaligned.h> | |
f0706e82 | 17 | #include <net/mac80211.h> |
eb063c17 | 18 | |
f0706e82 JB |
19 | #include "ieee80211_i.h" |
20 | #include "michael.h" | |
21 | #include "tkip.h" | |
22 | #include "aes_ccm.h" | |
765cb46a | 23 | #include "aes_cmac.h" |
f0706e82 JB |
24 | #include "wpa.h" |
25 | ||
9ae54c84 | 26 | ieee80211_tx_result |
5cf121c3 | 27 | ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx) |
f0706e82 | 28 | { |
8e8862b7 | 29 | u8 *data, *key, *mic, key_offset; |
f0706e82 | 30 | size_t data_len; |
8e8862b7 HH |
31 | unsigned int hdrlen; |
32 | struct ieee80211_hdr *hdr; | |
f0706e82 | 33 | struct sk_buff *skb = tx->skb; |
813d7669 | 34 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
f0706e82 | 35 | int authenticator; |
23c0752a | 36 | int tail; |
f0706e82 | 37 | |
c34498b9 | 38 | hdr = (struct ieee80211_hdr *)skb->data; |
8f20fc24 | 39 | if (!tx->key || tx->key->conf.alg != ALG_TKIP || skb->len < 24 || |
c34498b9 | 40 | !ieee80211_is_data_present(hdr->frame_control)) |
9ae54c84 | 41 | return TX_CONTINUE; |
f0706e82 | 42 | |
8e8862b7 HH |
43 | hdrlen = ieee80211_hdrlen(hdr->frame_control); |
44 | if (skb->len < hdrlen) | |
9ae54c84 | 45 | return TX_DROP; |
f0706e82 | 46 | |
8e8862b7 HH |
47 | data = skb->data + hdrlen; |
48 | data_len = skb->len - hdrlen; | |
49 | ||
813d7669 | 50 | if (info->control.hw_key && |
5cf121c3 | 51 | !(tx->flags & IEEE80211_TX_FRAGMENTED) && |
813d7669 JB |
52 | !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) { |
53 | /* hwaccel - with no need for SW-generated MMIC */ | |
9ae54c84 | 54 | return TX_CONTINUE; |
f0706e82 JB |
55 | } |
56 | ||
23c0752a | 57 | tail = MICHAEL_MIC_LEN; |
813d7669 | 58 | if (!info->control.hw_key) |
23c0752a JB |
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; | |
f0706e82 JB |
64 | |
65 | #if 0 | |
66 | authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */ | |
67 | #else | |
68 | authenticator = 1; | |
69 | #endif | |
ffd7891d LR |
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]; | |
f0706e82 | 74 | mic = skb_put(skb, MICHAEL_MIC_LEN); |
8e8862b7 | 75 | michael_mic(key, hdr, data, data_len, mic); |
f0706e82 | 76 | |
9ae54c84 | 77 | return TX_CONTINUE; |
f0706e82 JB |
78 | } |
79 | ||
80 | ||
9ae54c84 | 81 | ieee80211_rx_result |
5cf121c3 | 82 | ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx) |
f0706e82 | 83 | { |
8e8862b7 | 84 | u8 *data, *key = NULL, key_offset; |
f0706e82 | 85 | size_t data_len; |
8e8862b7 | 86 | unsigned int hdrlen; |
f0706e82 JB |
87 | u8 mic[MICHAEL_MIC_LEN]; |
88 | struct sk_buff *skb = rx->skb; | |
eb9fb5b8 JB |
89 | struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); |
90 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; | |
f0706e82 JB |
91 | int authenticator = 1, wpa_test = 0; |
92 | ||
c6a1fa12 | 93 | /* No way to verify the MIC if the hardware stripped it */ |
eb9fb5b8 | 94 | if (status->flag & RX_FLAG_MMIC_STRIPPED) |
9ae54c84 | 95 | return RX_CONTINUE; |
f0706e82 | 96 | |
8f20fc24 | 97 | if (!rx->key || rx->key->conf.alg != ALG_TKIP || |
c34498b9 HH |
98 | !ieee80211_has_protected(hdr->frame_control) || |
99 | !ieee80211_is_data_present(hdr->frame_control)) | |
9ae54c84 | 100 | return RX_CONTINUE; |
f0706e82 | 101 | |
8e8862b7 HH |
102 | hdrlen = ieee80211_hdrlen(hdr->frame_control); |
103 | if (skb->len < hdrlen + MICHAEL_MIC_LEN) | |
e4c26add | 104 | return RX_DROP_UNUSABLE; |
f0706e82 | 105 | |
8e8862b7 HH |
106 | data = skb->data + hdrlen; |
107 | data_len = skb->len - hdrlen - MICHAEL_MIC_LEN; | |
f0706e82 JB |
108 | |
109 | #if 0 | |
110 | authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */ | |
111 | #else | |
112 | authenticator = 1; | |
113 | #endif | |
ffd7891d LR |
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]; | |
8e8862b7 | 118 | michael_mic(key, hdr, data, data_len, mic); |
f0706e82 | 119 | if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) { |
5cf121c3 | 120 | if (!(rx->flags & IEEE80211_RX_RA_MATCH)) |
e4c26add | 121 | return RX_DROP_UNUSABLE; |
f0706e82 | 122 | |
f698d856 | 123 | mac80211_ev_michael_mic_failure(rx->sdata, rx->key->conf.keyidx, |
e6d6e342 JB |
124 | (void *) skb->data, NULL, |
125 | GFP_ATOMIC); | |
e4c26add | 126 | return RX_DROP_UNUSABLE; |
f0706e82 JB |
127 | } |
128 | ||
f0706e82 JB |
129 | /* remove Michael MIC from payload */ |
130 | skb_trim(skb, skb->len - MICHAEL_MIC_LEN); | |
131 | ||
50741ae0 | 132 | /* update IV in key information to be able to detect replays */ |
b0f76b33 HH |
133 | rx->key->u.tkip.rx[rx->queue].iv32 = rx->tkip_iv32; |
134 | rx->key->u.tkip.rx[rx->queue].iv16 = rx->tkip_iv16; | |
50741ae0 | 135 | |
9ae54c84 | 136 | return RX_CONTINUE; |
f0706e82 JB |
137 | } |
138 | ||
139 | ||
e039fa4a | 140 | static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) |
f0706e82 JB |
141 | { |
142 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; | |
143 | struct ieee80211_key *key = tx->key; | |
e039fa4a | 144 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
d5184cac HH |
145 | unsigned int hdrlen; |
146 | int len, tail; | |
f0706e82 JB |
147 | u8 *pos; |
148 | ||
813d7669 JB |
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 */ | |
23c0752a | 152 | return 0; |
e039fa4a JB |
153 | } |
154 | ||
d5184cac | 155 | hdrlen = ieee80211_hdrlen(hdr->frame_control); |
f0706e82 JB |
156 | len = skb->len - hdrlen; |
157 | ||
813d7669 | 158 | if (info->control.hw_key) |
23c0752a | 159 | tail = 0; |
11a843b7 | 160 | else |
23c0752a JB |
161 | tail = TKIP_ICV_LEN; |
162 | ||
163 | if (WARN_ON(skb_tailroom(skb) < tail || | |
164 | skb_headroom(skb) < TKIP_IV_LEN)) | |
165 | return -1; | |
f0706e82 JB |
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 */ | |
b0f76b33 HH |
172 | key->u.tkip.tx.iv16++; |
173 | if (key->u.tkip.tx.iv16 == 0) | |
174 | key->u.tkip.tx.iv32++; | |
f0706e82 | 175 | |
813d7669 | 176 | pos = ieee80211_tkip_add_iv(pos, key, key->u.tkip.tx.iv16); |
f0706e82 | 177 | |
813d7669 JB |
178 | /* hwaccel - with software IV */ |
179 | if (info->control.hw_key) | |
f0706e82 | 180 | return 0; |
f0706e82 JB |
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 | ||
9ae54c84 | 192 | ieee80211_tx_result |
5cf121c3 | 193 | ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx) |
f0706e82 | 194 | { |
f0706e82 | 195 | struct sk_buff *skb = tx->skb; |
f0706e82 | 196 | |
5cf121c3 | 197 | ieee80211_tx_set_protected(tx); |
f0706e82 | 198 | |
2de8e0d9 JB |
199 | do { |
200 | if (tkip_encrypt_skb(tx, skb) < 0) | |
201 | return TX_DROP; | |
202 | } while ((skb = skb->next)); | |
f0706e82 | 203 | |
9ae54c84 | 204 | return TX_CONTINUE; |
f0706e82 JB |
205 | } |
206 | ||
207 | ||
9ae54c84 | 208 | ieee80211_rx_result |
5cf121c3 | 209 | ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx) |
f0706e82 JB |
210 | { |
211 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; | |
f0706e82 JB |
212 | int hdrlen, res, hwaccel = 0, wpa_test = 0; |
213 | struct ieee80211_key *key = rx->key; | |
214 | struct sk_buff *skb = rx->skb; | |
eb9fb5b8 | 215 | struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); |
f0706e82 | 216 | |
d5184cac | 217 | hdrlen = ieee80211_hdrlen(hdr->frame_control); |
f0706e82 | 218 | |
c34498b9 | 219 | if (!ieee80211_is_data(hdr->frame_control)) |
9ae54c84 | 220 | return RX_CONTINUE; |
f0706e82 JB |
221 | |
222 | if (!rx->sta || skb->len - hdrlen < 12) | |
e4c26add | 223 | return RX_DROP_UNUSABLE; |
f0706e82 | 224 | |
eb9fb5b8 JB |
225 | if (status->flag & RX_FLAG_DECRYPTED) { |
226 | if (status->flag & RX_FLAG_IV_STRIPPED) { | |
7848ba7d JB |
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 | */ | |
9ae54c84 | 232 | return RX_CONTINUE; |
f0706e82 JB |
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, | |
17741cdc | 241 | skb->len - hdrlen, rx->sta->sta.addr, |
9ae4fda3 | 242 | hdr->addr1, hwaccel, rx->queue, |
5cf121c3 JB |
243 | &rx->tkip_iv32, |
244 | &rx->tkip_iv16); | |
f4ea83dd | 245 | if (res != TKIP_DECRYPT_OK || wpa_test) |
e4c26add | 246 | return RX_DROP_UNUSABLE; |
f0706e82 JB |
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 | ||
9ae54c84 | 255 | return RX_CONTINUE; |
f0706e82 JB |
256 | } |
257 | ||
258 | ||
feccb466 | 259 | static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch, |
f0706e82 JB |
260 | int encrypted) |
261 | { | |
f14df804 | 262 | __le16 mask_fc; |
fb733336 | 263 | int a4_included, mgmt; |
f14df804 | 264 | u8 qos_tid; |
feccb466 | 265 | u8 *b_0, *aad; |
f14df804 HH |
266 | u16 data_len, len_a; |
267 | unsigned int hdrlen; | |
268 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; | |
f0706e82 | 269 | |
feccb466 HH |
270 | b_0 = scratch + 3 * AES_BLOCK_LEN; |
271 | aad = scratch + 4 * AES_BLOCK_LEN; | |
272 | ||
f14df804 | 273 | /* |
fb733336 | 274 | * Mask FC: zero subtype b4 b5 b6 (if not mgmt) |
f14df804 HH |
275 | * Retry, PwrMgt, MoreData; set Protected |
276 | */ | |
fb733336 | 277 | mgmt = ieee80211_is_mgmt(hdr->frame_control); |
f14df804 | 278 | mask_fc = hdr->frame_control; |
fb733336 | 279 | mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | |
f14df804 | 280 | IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA); |
fb733336 JM |
281 | if (!mgmt) |
282 | mask_fc &= ~cpu_to_le16(0x0070); | |
f14df804 HH |
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); | |
f0706e82 | 288 | |
f14df804 HH |
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 */ | |
f0706e82 | 299 | b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */ |
fb733336 JM |
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); | |
73e1f7c8 | 304 | memcpy(&b_0[2], hdr->addr2, ETH_ALEN); |
f0706e82 JB |
305 | memcpy(&b_0[8], pn, CCMP_PN_LEN); |
306 | /* l(m) */ | |
f14df804 | 307 | put_unaligned_be16(data_len, &b_0[14]); |
f0706e82 JB |
308 | |
309 | /* AAD (extra authenticate-only data) / masked 802.11 header | |
310 | * FC | A1 | A2 | A3 | SC | [A4] | [QC] */ | |
f14df804 HH |
311 | put_unaligned_be16(len_a, &aad[0]); |
312 | put_unaligned(mask_fc, (__le16 *)&aad[2]); | |
73e1f7c8 | 313 | memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN); |
f0706e82 JB |
314 | |
315 | /* Mask Seq#, leave Frag# */ | |
316 | aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f; | |
317 | aad[23] = 0; | |
f14df804 | 318 | |
f0706e82 | 319 | if (a4_included) { |
73e1f7c8 | 320 | memcpy(&aad[24], hdr->addr4, ETH_ALEN); |
f14df804 | 321 | aad[30] = qos_tid; |
f0706e82 | 322 | aad[31] = 0; |
f14df804 | 323 | } else { |
73e1f7c8 | 324 | memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN); |
f14df804 | 325 | aad[24] = qos_tid; |
f0706e82 JB |
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 | ||
c6a1fa12 | 343 | static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr) |
f0706e82 JB |
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]; | |
f0706e82 JB |
351 | } |
352 | ||
353 | ||
e039fa4a | 354 | static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) |
f0706e82 JB |
355 | { |
356 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; | |
357 | struct ieee80211_key *key = tx->key; | |
e039fa4a | 358 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
23c0752a | 359 | int hdrlen, len, tail; |
feccb466 | 360 | u8 *pos, *pn; |
f0706e82 JB |
361 | int i; |
362 | ||
813d7669 JB |
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 | */ | |
23c0752a | 369 | return 0; |
e039fa4a JB |
370 | } |
371 | ||
d5184cac | 372 | hdrlen = ieee80211_hdrlen(hdr->frame_control); |
f0706e82 JB |
373 | len = skb->len - hdrlen; |
374 | ||
813d7669 | 375 | if (info->control.hw_key) |
23c0752a | 376 | tail = 0; |
11a843b7 | 377 | else |
23c0752a JB |
378 | tail = CCMP_MIC_LEN; |
379 | ||
380 | if (WARN_ON(skb_tailroom(skb) < tail || | |
381 | skb_headroom(skb) < CCMP_HDR_LEN)) | |
382 | return -1; | |
f0706e82 JB |
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 | ||
8f20fc24 | 398 | ccmp_pn2hdr(pos, pn, key->conf.keyidx); |
f0706e82 | 399 | |
813d7669 JB |
400 | /* hwaccel - with software CCMP header */ |
401 | if (info->control.hw_key) | |
f0706e82 | 402 | return 0; |
f0706e82 JB |
403 | |
404 | pos += CCMP_HDR_LEN; | |
feccb466 HH |
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, | |
f0706e82 JB |
407 | pos, skb_put(skb, CCMP_MIC_LEN)); |
408 | ||
409 | return 0; | |
410 | } | |
411 | ||
412 | ||
9ae54c84 | 413 | ieee80211_tx_result |
5cf121c3 | 414 | ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx) |
f0706e82 | 415 | { |
f0706e82 | 416 | struct sk_buff *skb = tx->skb; |
f0706e82 | 417 | |
5cf121c3 | 418 | ieee80211_tx_set_protected(tx); |
f0706e82 | 419 | |
2de8e0d9 JB |
420 | do { |
421 | if (ccmp_encrypt_skb(tx, skb) < 0) | |
422 | return TX_DROP; | |
423 | } while ((skb = skb->next)); | |
f0706e82 | 424 | |
9ae54c84 | 425 | return TX_CONTINUE; |
f0706e82 JB |
426 | } |
427 | ||
428 | ||
9ae54c84 | 429 | ieee80211_rx_result |
5cf121c3 | 430 | ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx) |
f0706e82 | 431 | { |
c34498b9 | 432 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data; |
f0706e82 JB |
433 | int hdrlen; |
434 | struct ieee80211_key *key = rx->key; | |
435 | struct sk_buff *skb = rx->skb; | |
eb9fb5b8 | 436 | struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); |
f0706e82 JB |
437 | u8 pn[CCMP_PN_LEN]; |
438 | int data_len; | |
439 | ||
d5184cac | 440 | hdrlen = ieee80211_hdrlen(hdr->frame_control); |
f0706e82 | 441 | |
fb733336 JM |
442 | if (!ieee80211_is_data(hdr->frame_control) && |
443 | !ieee80211_is_robust_mgmt_frame(hdr)) | |
9ae54c84 | 444 | return RX_CONTINUE; |
f0706e82 JB |
445 | |
446 | data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN; | |
447 | if (!rx->sta || data_len < 0) | |
e4c26add | 448 | return RX_DROP_UNUSABLE; |
f0706e82 | 449 | |
eb9fb5b8 JB |
450 | if ((status->flag & RX_FLAG_DECRYPTED) && |
451 | (status->flag & RX_FLAG_IV_STRIPPED)) | |
9ae54c84 | 452 | return RX_CONTINUE; |
f0706e82 | 453 | |
c6a1fa12 | 454 | ccmp_hdr2pn(pn, skb->data + hdrlen); |
f0706e82 | 455 | |
5cf121c3 | 456 | if (memcmp(pn, key->u.ccmp.rx_pn[rx->queue], CCMP_PN_LEN) <= 0) { |
f0706e82 | 457 | key->u.ccmp.replays++; |
e4c26add | 458 | return RX_DROP_UNUSABLE; |
f0706e82 JB |
459 | } |
460 | ||
eb9fb5b8 | 461 | if (!(status->flag & RX_FLAG_DECRYPTED)) { |
7848ba7d | 462 | /* hardware didn't decrypt/verify MIC */ |
feccb466 | 463 | ccmp_special_blocks(skb, pn, key->u.ccmp.rx_crypto_buf, 1); |
f0706e82 JB |
464 | |
465 | if (ieee80211_aes_ccm_decrypt( | |
feccb466 | 466 | key->u.ccmp.tfm, key->u.ccmp.rx_crypto_buf, |
f0706e82 JB |
467 | skb->data + hdrlen + CCMP_HDR_LEN, data_len, |
468 | skb->data + skb->len - CCMP_MIC_LEN, | |
c6a1fa12 | 469 | skb->data + hdrlen + CCMP_HDR_LEN)) |
e4c26add | 470 | return RX_DROP_UNUSABLE; |
f0706e82 JB |
471 | } |
472 | ||
5cf121c3 | 473 | memcpy(key->u.ccmp.rx_pn[rx->queue], pn, CCMP_PN_LEN); |
f0706e82 JB |
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 | ||
9ae54c84 | 480 | return RX_CONTINUE; |
f0706e82 | 481 | } |
765cb46a JM |
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 | ||
813d7669 | 518 | if (info->control.hw_key) |
765cb46a | 519 | return 0; |
765cb46a JM |
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; | |
eb9fb5b8 | 555 | struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); |
765cb46a JM |
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 | ||
eb9fb5b8 JB |
564 | if ((status->flag & RX_FLAG_DECRYPTED) && |
565 | (status->flag & RX_FLAG_IV_STRIPPED)) | |
765cb46a JM |
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 | ||
eb9fb5b8 | 584 | if (!(status->flag & RX_FLAG_DECRYPTED)) { |
765cb46a JM |
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 | } |