2 * Copyright 2002-2004, Instant802 Networks, Inc.
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
9 #include <linux/netdevice.h>
10 #include <linux/types.h>
11 #include <linux/slab.h>
12 #include <linux/skbuff.h>
13 #include <linux/compiler.h>
14 #include <linux/ieee80211.h>
15 #include <asm/unaligned.h>
16 #include <net/mac80211.h>
18 #include "ieee80211_i.h"
25 ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
27 u8 *data, *key, *mic, key_offset;
30 struct ieee80211_hdr *hdr;
31 struct sk_buff *skb = tx->skb;
36 hdr = (struct ieee80211_hdr *)skb->data;
37 if (!tx->key || tx->key->conf.alg != ALG_TKIP || skb->len < 24 ||
38 !ieee80211_is_data_present(hdr->frame_control))
41 hdrlen = ieee80211_hdrlen(hdr->frame_control);
42 if (skb->len < hdrlen)
45 data = skb->data + hdrlen;
46 data_len = skb->len - hdrlen;
48 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
49 !(tx->flags & IEEE80211_TX_FRAGMENTED) &&
50 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) &&
52 /* hwaccel - with no need for preallocated room for Michael MIC
57 tail = MICHAEL_MIC_LEN;
58 if (!(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
61 if (WARN_ON(skb_tailroom(skb) < tail ||
62 skb_headroom(skb) < TKIP_IV_LEN))
66 authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
70 /* At this point we know we're using ALG_TKIP. To get the MIC key
71 * we now will rely on the offset from the ieee80211_key_conf::key */
72 key_offset = authenticator ?
73 NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY :
74 NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY;
75 key = &tx->key->conf.key[key_offset];
76 mic = skb_put(skb, MICHAEL_MIC_LEN);
77 michael_mic(key, hdr, data, data_len, mic);
84 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
86 u8 *data, *key = NULL, key_offset;
89 struct ieee80211_hdr *hdr;
90 u8 mic[MICHAEL_MIC_LEN];
91 struct sk_buff *skb = rx->skb;
92 int authenticator = 1, wpa_test = 0;
95 * No way to verify the MIC if the hardware stripped it
97 if (rx->status->flag & RX_FLAG_MMIC_STRIPPED)
100 hdr = (struct ieee80211_hdr *)skb->data;
101 if (!rx->key || rx->key->conf.alg != ALG_TKIP ||
102 !ieee80211_has_protected(hdr->frame_control) ||
103 !ieee80211_is_data_present(hdr->frame_control))
106 hdrlen = ieee80211_hdrlen(hdr->frame_control);
107 if (skb->len < hdrlen + MICHAEL_MIC_LEN)
108 return RX_DROP_UNUSABLE;
110 data = skb->data + hdrlen;
111 data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;
114 authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
118 /* At this point we know we're using ALG_TKIP. To get the MIC key
119 * we now will rely on the offset from the ieee80211_key_conf::key */
120 key_offset = authenticator ?
121 NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY :
122 NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY;
123 key = &rx->key->conf.key[key_offset];
124 michael_mic(key, hdr, data, data_len, mic);
125 if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) {
126 if (!(rx->flags & IEEE80211_RX_RA_MATCH))
127 return RX_DROP_UNUSABLE;
129 mac80211_ev_michael_mic_failure(rx->sdata, rx->key->conf.keyidx,
131 return RX_DROP_UNUSABLE;
134 /* remove Michael MIC from payload */
135 skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
137 /* update IV in key information to be able to detect replays */
138 rx->key->u.tkip.rx[rx->queue].iv32 = rx->tkip_iv32;
139 rx->key->u.tkip.rx[rx->queue].iv16 = rx->tkip_iv16;
145 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
147 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
148 struct ieee80211_key *key = tx->key;
149 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
154 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
155 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
156 /* hwaccel - with no need for preallocated room for IV/ICV */
157 info->control.hw_key = &tx->key->conf;
161 hdrlen = ieee80211_hdrlen(hdr->frame_control);
162 len = skb->len - hdrlen;
164 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
169 if (WARN_ON(skb_tailroom(skb) < tail ||
170 skb_headroom(skb) < TKIP_IV_LEN))
173 pos = skb_push(skb, TKIP_IV_LEN);
174 memmove(pos, pos + TKIP_IV_LEN, hdrlen);
177 /* Increase IV for the frame */
178 key->u.tkip.tx.iv16++;
179 if (key->u.tkip.tx.iv16 == 0)
180 key->u.tkip.tx.iv32++;
182 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
183 /* hwaccel - with preallocated room for IV */
184 ieee80211_tkip_add_iv(pos, key, key->u.tkip.tx.iv16);
186 info->control.hw_key = &tx->key->conf;
190 /* Add room for ICV */
191 skb_put(skb, TKIP_ICV_LEN);
193 hdr = (struct ieee80211_hdr *) skb->data;
194 ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
195 key, pos, len, hdr->addr2);
201 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
203 struct sk_buff *skb = tx->skb;
205 ieee80211_tx_set_protected(tx);
207 if (tkip_encrypt_skb(tx, skb) < 0)
210 if (tx->extra_frag) {
212 for (i = 0; i < tx->num_extra_frag; i++) {
213 if (tkip_encrypt_skb(tx, tx->extra_frag[i]) < 0)
223 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
225 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
226 int hdrlen, res, hwaccel = 0, wpa_test = 0;
227 struct ieee80211_key *key = rx->key;
228 struct sk_buff *skb = rx->skb;
230 hdrlen = ieee80211_hdrlen(hdr->frame_control);
232 if (!ieee80211_is_data(hdr->frame_control))
235 if (!rx->sta || skb->len - hdrlen < 12)
236 return RX_DROP_UNUSABLE;
238 if (rx->status->flag & RX_FLAG_DECRYPTED) {
239 if (rx->status->flag & RX_FLAG_IV_STRIPPED) {
241 * Hardware took care of all processing, including
242 * replay protection, and stripped the ICV/IV so
243 * we cannot do any checks here.
248 /* let TKIP code verify IV, but skip decryption */
252 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
253 key, skb->data + hdrlen,
254 skb->len - hdrlen, rx->sta->sta.addr,
255 hdr->addr1, hwaccel, rx->queue,
258 if (res != TKIP_DECRYPT_OK || wpa_test)
259 return RX_DROP_UNUSABLE;
262 skb_trim(skb, skb->len - TKIP_ICV_LEN);
265 memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
266 skb_pull(skb, TKIP_IV_LEN);
272 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch,
281 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
283 b_0 = scratch + 3 * AES_BLOCK_LEN;
284 aad = scratch + 4 * AES_BLOCK_LEN;
287 * Mask FC: zero subtype b4 b5 b6
288 * Retry, PwrMgt, MoreData; set Protected
290 mask_fc = hdr->frame_control;
291 mask_fc &= ~cpu_to_le16(0x0070 | IEEE80211_FCTL_RETRY |
292 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
293 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
295 hdrlen = ieee80211_hdrlen(hdr->frame_control);
297 a4_included = ieee80211_has_a4(hdr->frame_control);
299 if (ieee80211_is_data_qos(hdr->frame_control))
300 qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
304 data_len = skb->len - hdrlen - CCMP_HDR_LEN;
306 data_len -= CCMP_MIC_LEN;
308 /* First block, b_0 */
309 b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
310 /* Nonce: QoS Priority | A2 | PN */
312 memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
313 memcpy(&b_0[8], pn, CCMP_PN_LEN);
315 put_unaligned_be16(data_len, &b_0[14]);
317 /* AAD (extra authenticate-only data) / masked 802.11 header
318 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
319 put_unaligned_be16(len_a, &aad[0]);
320 put_unaligned(mask_fc, (__le16 *)&aad[2]);
321 memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
323 /* Mask Seq#, leave Frag# */
324 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
328 memcpy(&aad[24], hdr->addr4, ETH_ALEN);
332 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
338 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
343 hdr[3] = 0x20 | (key_id << 6);
351 static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr)
359 return (hdr[3] >> 6) & 0x03;
363 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
365 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
366 struct ieee80211_key *key = tx->key;
367 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
368 int hdrlen, len, tail;
372 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
373 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
374 /* hwaccel - with no need for preallocated room for CCMP "
375 * header or MIC fields */
376 info->control.hw_key = &tx->key->conf;
380 hdrlen = ieee80211_hdrlen(hdr->frame_control);
381 len = skb->len - hdrlen;
383 if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
388 if (WARN_ON(skb_tailroom(skb) < tail ||
389 skb_headroom(skb) < CCMP_HDR_LEN))
392 pos = skb_push(skb, CCMP_HDR_LEN);
393 memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
394 hdr = (struct ieee80211_hdr *) pos;
398 pn = key->u.ccmp.tx_pn;
400 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
406 ccmp_pn2hdr(pos, pn, key->conf.keyidx);
408 if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
409 /* hwaccel - with preallocated room for CCMP header */
410 info->control.hw_key = &tx->key->conf;
415 ccmp_special_blocks(skb, pn, key->u.ccmp.tx_crypto_buf, 0);
416 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, key->u.ccmp.tx_crypto_buf, pos, len,
417 pos, skb_put(skb, CCMP_MIC_LEN));
424 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx)
426 struct sk_buff *skb = tx->skb;
428 ieee80211_tx_set_protected(tx);
430 if (ccmp_encrypt_skb(tx, skb) < 0)
433 if (tx->extra_frag) {
435 for (i = 0; i < tx->num_extra_frag; i++) {
436 if (ccmp_encrypt_skb(tx, tx->extra_frag[i]) < 0)
446 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx)
448 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
450 struct ieee80211_key *key = rx->key;
451 struct sk_buff *skb = rx->skb;
455 hdrlen = ieee80211_hdrlen(hdr->frame_control);
457 if (!ieee80211_is_data(hdr->frame_control))
460 data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
461 if (!rx->sta || data_len < 0)
462 return RX_DROP_UNUSABLE;
464 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
465 (rx->status->flag & RX_FLAG_IV_STRIPPED))
468 (void) ccmp_hdr2pn(pn, skb->data + hdrlen);
470 if (memcmp(pn, key->u.ccmp.rx_pn[rx->queue], CCMP_PN_LEN) <= 0) {
471 key->u.ccmp.replays++;
472 return RX_DROP_UNUSABLE;
475 if (!(rx->status->flag & RX_FLAG_DECRYPTED)) {
476 /* hardware didn't decrypt/verify MIC */
477 ccmp_special_blocks(skb, pn, key->u.ccmp.rx_crypto_buf, 1);
479 if (ieee80211_aes_ccm_decrypt(
480 key->u.ccmp.tfm, key->u.ccmp.rx_crypto_buf,
481 skb->data + hdrlen + CCMP_HDR_LEN, data_len,
482 skb->data + skb->len - CCMP_MIC_LEN,
483 skb->data + hdrlen + CCMP_HDR_LEN)) {
484 return RX_DROP_UNUSABLE;
488 memcpy(key->u.ccmp.rx_pn[rx->queue], pn, CCMP_PN_LEN);
490 /* Remove CCMP header and MIC */
491 skb_trim(skb, skb->len - CCMP_MIC_LEN);
492 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
493 skb_pull(skb, CCMP_HDR_LEN);