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Commit | Line | Data |
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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> | |
f0706e82 JB |
12 | #include <linux/skbuff.h> |
13 | #include <linux/compiler.h> | |
f14df804 | 14 | #include <linux/ieee80211.h> |
5a0e3ad6 | 15 | #include <linux/gfp.h> |
f14df804 | 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; |
97359d12 JB |
39 | if (!tx->key || tx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP || |
40 | skb->len < 24 || !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 | |
97359d12 | 97 | if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_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) { |
554891e6 | 120 | if (!(status->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; | |
3473187d JL |
186 | return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm, |
187 | key, pos, len, hdr->addr2); | |
f0706e82 JB |
188 | } |
189 | ||
190 | ||
9ae54c84 | 191 | ieee80211_tx_result |
5cf121c3 | 192 | ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx) |
f0706e82 | 193 | { |
f0706e82 | 194 | struct sk_buff *skb = tx->skb; |
f0706e82 | 195 | |
5cf121c3 | 196 | ieee80211_tx_set_protected(tx); |
f0706e82 | 197 | |
2de8e0d9 JB |
198 | do { |
199 | if (tkip_encrypt_skb(tx, skb) < 0) | |
200 | return TX_DROP; | |
201 | } while ((skb = skb->next)); | |
f0706e82 | 202 | |
9ae54c84 | 203 | return TX_CONTINUE; |
f0706e82 JB |
204 | } |
205 | ||
206 | ||
9ae54c84 | 207 | ieee80211_rx_result |
5cf121c3 | 208 | ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx) |
f0706e82 JB |
209 | { |
210 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; | |
f0706e82 JB |
211 | int hdrlen, res, hwaccel = 0, wpa_test = 0; |
212 | struct ieee80211_key *key = rx->key; | |
213 | struct sk_buff *skb = rx->skb; | |
eb9fb5b8 | 214 | struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); |
f0706e82 | 215 | |
d5184cac | 216 | hdrlen = ieee80211_hdrlen(hdr->frame_control); |
f0706e82 | 217 | |
c34498b9 | 218 | if (!ieee80211_is_data(hdr->frame_control)) |
9ae54c84 | 219 | return RX_CONTINUE; |
f0706e82 JB |
220 | |
221 | if (!rx->sta || skb->len - hdrlen < 12) | |
e4c26add | 222 | return RX_DROP_UNUSABLE; |
f0706e82 | 223 | |
dc1580dd JB |
224 | /* |
225 | * Let TKIP code verify IV, but skip decryption. | |
226 | * In the case where hardware checks the IV as well, | |
227 | * we don't even get here, see ieee80211_rx_h_decrypt() | |
228 | */ | |
229 | if (status->flag & RX_FLAG_DECRYPTED) | |
f0706e82 | 230 | hwaccel = 1; |
f0706e82 JB |
231 | |
232 | res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm, | |
233 | key, skb->data + hdrlen, | |
17741cdc | 234 | skb->len - hdrlen, rx->sta->sta.addr, |
9ae4fda3 | 235 | hdr->addr1, hwaccel, rx->queue, |
5cf121c3 JB |
236 | &rx->tkip_iv32, |
237 | &rx->tkip_iv16); | |
f4ea83dd | 238 | if (res != TKIP_DECRYPT_OK || wpa_test) |
e4c26add | 239 | return RX_DROP_UNUSABLE; |
f0706e82 JB |
240 | |
241 | /* Trim ICV */ | |
242 | skb_trim(skb, skb->len - TKIP_ICV_LEN); | |
243 | ||
244 | /* Remove IV */ | |
245 | memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen); | |
246 | skb_pull(skb, TKIP_IV_LEN); | |
247 | ||
9ae54c84 | 248 | return RX_CONTINUE; |
f0706e82 JB |
249 | } |
250 | ||
251 | ||
feccb466 | 252 | static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch, |
f0706e82 JB |
253 | int encrypted) |
254 | { | |
f14df804 | 255 | __le16 mask_fc; |
fb733336 | 256 | int a4_included, mgmt; |
f14df804 | 257 | u8 qos_tid; |
feccb466 | 258 | u8 *b_0, *aad; |
f14df804 HH |
259 | u16 data_len, len_a; |
260 | unsigned int hdrlen; | |
261 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; | |
f0706e82 | 262 | |
feccb466 HH |
263 | b_0 = scratch + 3 * AES_BLOCK_LEN; |
264 | aad = scratch + 4 * AES_BLOCK_LEN; | |
265 | ||
f14df804 | 266 | /* |
fb733336 | 267 | * Mask FC: zero subtype b4 b5 b6 (if not mgmt) |
f14df804 HH |
268 | * Retry, PwrMgt, MoreData; set Protected |
269 | */ | |
fb733336 | 270 | mgmt = ieee80211_is_mgmt(hdr->frame_control); |
f14df804 | 271 | mask_fc = hdr->frame_control; |
fb733336 | 272 | mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | |
f14df804 | 273 | IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA); |
fb733336 JM |
274 | if (!mgmt) |
275 | mask_fc &= ~cpu_to_le16(0x0070); | |
f14df804 HH |
276 | mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); |
277 | ||
278 | hdrlen = ieee80211_hdrlen(hdr->frame_control); | |
279 | len_a = hdrlen - 2; | |
280 | a4_included = ieee80211_has_a4(hdr->frame_control); | |
f0706e82 | 281 | |
f14df804 HH |
282 | if (ieee80211_is_data_qos(hdr->frame_control)) |
283 | qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK; | |
284 | else | |
285 | qos_tid = 0; | |
286 | ||
287 | data_len = skb->len - hdrlen - CCMP_HDR_LEN; | |
288 | if (encrypted) | |
289 | data_len -= CCMP_MIC_LEN; | |
290 | ||
291 | /* First block, b_0 */ | |
f0706e82 | 292 | b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */ |
fb733336 JM |
293 | /* Nonce: Nonce Flags | A2 | PN |
294 | * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7) | |
295 | */ | |
296 | b_0[1] = qos_tid | (mgmt << 4); | |
73e1f7c8 | 297 | memcpy(&b_0[2], hdr->addr2, ETH_ALEN); |
f0706e82 JB |
298 | memcpy(&b_0[8], pn, CCMP_PN_LEN); |
299 | /* l(m) */ | |
f14df804 | 300 | put_unaligned_be16(data_len, &b_0[14]); |
f0706e82 JB |
301 | |
302 | /* AAD (extra authenticate-only data) / masked 802.11 header | |
303 | * FC | A1 | A2 | A3 | SC | [A4] | [QC] */ | |
f14df804 HH |
304 | put_unaligned_be16(len_a, &aad[0]); |
305 | put_unaligned(mask_fc, (__le16 *)&aad[2]); | |
73e1f7c8 | 306 | memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN); |
f0706e82 JB |
307 | |
308 | /* Mask Seq#, leave Frag# */ | |
309 | aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f; | |
310 | aad[23] = 0; | |
f14df804 | 311 | |
f0706e82 | 312 | if (a4_included) { |
73e1f7c8 | 313 | memcpy(&aad[24], hdr->addr4, ETH_ALEN); |
f14df804 | 314 | aad[30] = qos_tid; |
f0706e82 | 315 | aad[31] = 0; |
f14df804 | 316 | } else { |
73e1f7c8 | 317 | memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN); |
f14df804 | 318 | aad[24] = qos_tid; |
f0706e82 JB |
319 | } |
320 | } | |
321 | ||
322 | ||
323 | static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id) | |
324 | { | |
325 | hdr[0] = pn[5]; | |
326 | hdr[1] = pn[4]; | |
327 | hdr[2] = 0; | |
328 | hdr[3] = 0x20 | (key_id << 6); | |
329 | hdr[4] = pn[3]; | |
330 | hdr[5] = pn[2]; | |
331 | hdr[6] = pn[1]; | |
332 | hdr[7] = pn[0]; | |
333 | } | |
334 | ||
335 | ||
c6a1fa12 | 336 | static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr) |
f0706e82 JB |
337 | { |
338 | pn[0] = hdr[7]; | |
339 | pn[1] = hdr[6]; | |
340 | pn[2] = hdr[5]; | |
341 | pn[3] = hdr[4]; | |
342 | pn[4] = hdr[1]; | |
343 | pn[5] = hdr[0]; | |
f0706e82 JB |
344 | } |
345 | ||
346 | ||
e039fa4a | 347 | static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb) |
f0706e82 JB |
348 | { |
349 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; | |
350 | struct ieee80211_key *key = tx->key; | |
e039fa4a | 351 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
23c0752a | 352 | int hdrlen, len, tail; |
feccb466 | 353 | u8 *pos, *pn; |
f0706e82 JB |
354 | int i; |
355 | ||
813d7669 JB |
356 | if (info->control.hw_key && |
357 | !(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV)) { | |
358 | /* | |
359 | * hwaccel has no need for preallocated room for CCMP | |
360 | * header or MIC fields | |
361 | */ | |
23c0752a | 362 | return 0; |
e039fa4a JB |
363 | } |
364 | ||
d5184cac | 365 | hdrlen = ieee80211_hdrlen(hdr->frame_control); |
f0706e82 JB |
366 | len = skb->len - hdrlen; |
367 | ||
813d7669 | 368 | if (info->control.hw_key) |
23c0752a | 369 | tail = 0; |
11a843b7 | 370 | else |
23c0752a JB |
371 | tail = CCMP_MIC_LEN; |
372 | ||
373 | if (WARN_ON(skb_tailroom(skb) < tail || | |
374 | skb_headroom(skb) < CCMP_HDR_LEN)) | |
375 | return -1; | |
f0706e82 JB |
376 | |
377 | pos = skb_push(skb, CCMP_HDR_LEN); | |
378 | memmove(pos, pos + CCMP_HDR_LEN, hdrlen); | |
379 | hdr = (struct ieee80211_hdr *) pos; | |
380 | pos += hdrlen; | |
381 | ||
382 | /* PN = PN + 1 */ | |
383 | pn = key->u.ccmp.tx_pn; | |
384 | ||
385 | for (i = CCMP_PN_LEN - 1; i >= 0; i--) { | |
386 | pn[i]++; | |
387 | if (pn[i]) | |
388 | break; | |
389 | } | |
390 | ||
8f20fc24 | 391 | ccmp_pn2hdr(pos, pn, key->conf.keyidx); |
f0706e82 | 392 | |
813d7669 JB |
393 | /* hwaccel - with software CCMP header */ |
394 | if (info->control.hw_key) | |
f0706e82 | 395 | return 0; |
f0706e82 JB |
396 | |
397 | pos += CCMP_HDR_LEN; | |
feccb466 HH |
398 | ccmp_special_blocks(skb, pn, key->u.ccmp.tx_crypto_buf, 0); |
399 | ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, key->u.ccmp.tx_crypto_buf, pos, len, | |
f0706e82 JB |
400 | pos, skb_put(skb, CCMP_MIC_LEN)); |
401 | ||
402 | return 0; | |
403 | } | |
404 | ||
405 | ||
9ae54c84 | 406 | ieee80211_tx_result |
5cf121c3 | 407 | ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx) |
f0706e82 | 408 | { |
f0706e82 | 409 | struct sk_buff *skb = tx->skb; |
f0706e82 | 410 | |
5cf121c3 | 411 | ieee80211_tx_set_protected(tx); |
f0706e82 | 412 | |
2de8e0d9 JB |
413 | do { |
414 | if (ccmp_encrypt_skb(tx, skb) < 0) | |
415 | return TX_DROP; | |
416 | } while ((skb = skb->next)); | |
f0706e82 | 417 | |
9ae54c84 | 418 | return TX_CONTINUE; |
f0706e82 JB |
419 | } |
420 | ||
421 | ||
9ae54c84 | 422 | ieee80211_rx_result |
5cf121c3 | 423 | ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx) |
f0706e82 | 424 | { |
c34498b9 | 425 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data; |
f0706e82 JB |
426 | int hdrlen; |
427 | struct ieee80211_key *key = rx->key; | |
428 | struct sk_buff *skb = rx->skb; | |
eb9fb5b8 | 429 | struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); |
f0706e82 JB |
430 | u8 pn[CCMP_PN_LEN]; |
431 | int data_len; | |
9190252c | 432 | int queue; |
f0706e82 | 433 | |
d5184cac | 434 | hdrlen = ieee80211_hdrlen(hdr->frame_control); |
f0706e82 | 435 | |
fb733336 JM |
436 | if (!ieee80211_is_data(hdr->frame_control) && |
437 | !ieee80211_is_robust_mgmt_frame(hdr)) | |
9ae54c84 | 438 | return RX_CONTINUE; |
f0706e82 JB |
439 | |
440 | data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN; | |
441 | if (!rx->sta || data_len < 0) | |
e4c26add | 442 | return RX_DROP_UNUSABLE; |
f0706e82 | 443 | |
c6a1fa12 | 444 | ccmp_hdr2pn(pn, skb->data + hdrlen); |
f0706e82 | 445 | |
9190252c JM |
446 | queue = ieee80211_is_mgmt(hdr->frame_control) ? |
447 | NUM_RX_DATA_QUEUES : rx->queue; | |
448 | ||
449 | if (memcmp(pn, key->u.ccmp.rx_pn[queue], CCMP_PN_LEN) <= 0) { | |
f0706e82 | 450 | key->u.ccmp.replays++; |
e4c26add | 451 | return RX_DROP_UNUSABLE; |
f0706e82 JB |
452 | } |
453 | ||
eb9fb5b8 | 454 | if (!(status->flag & RX_FLAG_DECRYPTED)) { |
7848ba7d | 455 | /* hardware didn't decrypt/verify MIC */ |
feccb466 | 456 | ccmp_special_blocks(skb, pn, key->u.ccmp.rx_crypto_buf, 1); |
f0706e82 JB |
457 | |
458 | if (ieee80211_aes_ccm_decrypt( | |
feccb466 | 459 | key->u.ccmp.tfm, key->u.ccmp.rx_crypto_buf, |
f0706e82 JB |
460 | skb->data + hdrlen + CCMP_HDR_LEN, data_len, |
461 | skb->data + skb->len - CCMP_MIC_LEN, | |
c6a1fa12 | 462 | skb->data + hdrlen + CCMP_HDR_LEN)) |
e4c26add | 463 | return RX_DROP_UNUSABLE; |
f0706e82 JB |
464 | } |
465 | ||
9190252c | 466 | memcpy(key->u.ccmp.rx_pn[queue], pn, CCMP_PN_LEN); |
f0706e82 JB |
467 | |
468 | /* Remove CCMP header and MIC */ | |
469 | skb_trim(skb, skb->len - CCMP_MIC_LEN); | |
470 | memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen); | |
471 | skb_pull(skb, CCMP_HDR_LEN); | |
472 | ||
9ae54c84 | 473 | return RX_CONTINUE; |
f0706e82 | 474 | } |
765cb46a JM |
475 | |
476 | ||
477 | static void bip_aad(struct sk_buff *skb, u8 *aad) | |
478 | { | |
479 | /* BIP AAD: FC(masked) || A1 || A2 || A3 */ | |
480 | ||
481 | /* FC type/subtype */ | |
482 | aad[0] = skb->data[0]; | |
483 | /* Mask FC Retry, PwrMgt, MoreData flags to zero */ | |
484 | aad[1] = skb->data[1] & ~(BIT(4) | BIT(5) | BIT(6)); | |
485 | /* A1 || A2 || A3 */ | |
486 | memcpy(aad + 2, skb->data + 4, 3 * ETH_ALEN); | |
487 | } | |
488 | ||
489 | ||
490 | static inline void bip_ipn_swap(u8 *d, const u8 *s) | |
491 | { | |
492 | *d++ = s[5]; | |
493 | *d++ = s[4]; | |
494 | *d++ = s[3]; | |
495 | *d++ = s[2]; | |
496 | *d++ = s[1]; | |
497 | *d = s[0]; | |
498 | } | |
499 | ||
500 | ||
501 | ieee80211_tx_result | |
502 | ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx) | |
503 | { | |
504 | struct sk_buff *skb = tx->skb; | |
505 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); | |
506 | struct ieee80211_key *key = tx->key; | |
507 | struct ieee80211_mmie *mmie; | |
508 | u8 *pn, aad[20]; | |
509 | int i; | |
510 | ||
813d7669 | 511 | if (info->control.hw_key) |
765cb46a | 512 | return 0; |
765cb46a JM |
513 | |
514 | if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie))) | |
515 | return TX_DROP; | |
516 | ||
517 | mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie)); | |
518 | mmie->element_id = WLAN_EID_MMIE; | |
519 | mmie->length = sizeof(*mmie) - 2; | |
520 | mmie->key_id = cpu_to_le16(key->conf.keyidx); | |
521 | ||
522 | /* PN = PN + 1 */ | |
523 | pn = key->u.aes_cmac.tx_pn; | |
524 | ||
525 | for (i = sizeof(key->u.aes_cmac.tx_pn) - 1; i >= 0; i--) { | |
526 | pn[i]++; | |
527 | if (pn[i]) | |
528 | break; | |
529 | } | |
530 | bip_ipn_swap(mmie->sequence_number, pn); | |
531 | ||
532 | bip_aad(skb, aad); | |
533 | ||
534 | /* | |
535 | * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64) | |
536 | */ | |
537 | ieee80211_aes_cmac(key->u.aes_cmac.tfm, key->u.aes_cmac.tx_crypto_buf, | |
538 | aad, skb->data + 24, skb->len - 24, mmie->mic); | |
539 | ||
540 | return TX_CONTINUE; | |
541 | } | |
542 | ||
543 | ||
544 | ieee80211_rx_result | |
545 | ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx) | |
546 | { | |
547 | struct sk_buff *skb = rx->skb; | |
eb9fb5b8 | 548 | struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); |
765cb46a JM |
549 | struct ieee80211_key *key = rx->key; |
550 | struct ieee80211_mmie *mmie; | |
551 | u8 aad[20], mic[8], ipn[6]; | |
552 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; | |
553 | ||
554 | if (!ieee80211_is_mgmt(hdr->frame_control)) | |
555 | return RX_CONTINUE; | |
556 | ||
765cb46a JM |
557 | if (skb->len < 24 + sizeof(*mmie)) |
558 | return RX_DROP_UNUSABLE; | |
559 | ||
560 | mmie = (struct ieee80211_mmie *) | |
561 | (skb->data + skb->len - sizeof(*mmie)); | |
562 | if (mmie->element_id != WLAN_EID_MMIE || | |
563 | mmie->length != sizeof(*mmie) - 2) | |
564 | return RX_DROP_UNUSABLE; /* Invalid MMIE */ | |
565 | ||
566 | bip_ipn_swap(ipn, mmie->sequence_number); | |
567 | ||
568 | if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) { | |
569 | key->u.aes_cmac.replays++; | |
570 | return RX_DROP_UNUSABLE; | |
571 | } | |
572 | ||
eb9fb5b8 | 573 | if (!(status->flag & RX_FLAG_DECRYPTED)) { |
765cb46a JM |
574 | /* hardware didn't decrypt/verify MIC */ |
575 | bip_aad(skb, aad); | |
576 | ieee80211_aes_cmac(key->u.aes_cmac.tfm, | |
577 | key->u.aes_cmac.rx_crypto_buf, aad, | |
578 | skb->data + 24, skb->len - 24, mic); | |
579 | if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) { | |
580 | key->u.aes_cmac.icverrors++; | |
581 | return RX_DROP_UNUSABLE; | |
582 | } | |
583 | } | |
584 | ||
585 | memcpy(key->u.aes_cmac.rx_pn, ipn, 6); | |
586 | ||
587 | /* Remove MMIE */ | |
588 | skb_trim(skb, skb->len - sizeof(*mmie)); | |
589 | ||
590 | return RX_CONTINUE; | |
591 | } |