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 <net/mac80211.h>
16 #include "ieee80211_i.h"
22 static int ieee80211_get_hdr_info(const struct sk_buff *skb, u8 **sa, u8 **da,
23 u8 *qos_tid, u8 **data, size_t *data_len)
25 struct ieee80211_hdr *hdr;
29 hdr = (struct ieee80211_hdr *)skb->data;
30 fc = hdr->frame_control;
32 hdrlen = ieee80211_hdrlen(fc);
34 *sa = ieee80211_get_SA(hdr);
35 *da = ieee80211_get_DA(hdr);
37 *data = skb->data + hdrlen;
38 *data_len = skb->len - hdrlen;
40 if (ieee80211_is_data_qos(fc))
41 *qos_tid = (*ieee80211_get_qos_ctl(hdr) & 0x0f) | 0x80;
45 return skb->len < hdrlen ? -1 : 0;
50 ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
52 u8 *data, *sa, *da, *key, *mic, qos_tid;
55 struct sk_buff *skb = tx->skb;
62 if (!tx->key || tx->key->conf.alg != ALG_TKIP || skb->len < 24 ||
63 !WLAN_FC_DATA_PRESENT(fc))
66 if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len))
69 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
70 !(tx->flags & IEEE80211_TX_FRAGMENTED) &&
71 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) &&
73 /* hwaccel - with no need for preallocated room for Michael MIC
78 tail = MICHAEL_MIC_LEN;
79 if (!(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
82 if (WARN_ON(skb_tailroom(skb) < tail ||
83 skb_headroom(skb) < TKIP_IV_LEN))
87 authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
91 key = &tx->key->conf.key[authenticator ? ALG_TKIP_TEMP_AUTH_TX_MIC_KEY :
92 ALG_TKIP_TEMP_AUTH_RX_MIC_KEY];
93 mic = skb_put(skb, MICHAEL_MIC_LEN);
94 michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
101 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
103 u8 *data, *sa, *da, *key = NULL, qos_tid;
106 u8 mic[MICHAEL_MIC_LEN];
107 struct sk_buff *skb = rx->skb;
108 int authenticator = 1, wpa_test = 0;
109 DECLARE_MAC_BUF(mac);
114 * No way to verify the MIC if the hardware stripped it
116 if (rx->status->flag & RX_FLAG_MMIC_STRIPPED)
119 if (!rx->key || rx->key->conf.alg != ALG_TKIP ||
120 !(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc))
123 if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)
124 || data_len < MICHAEL_MIC_LEN)
125 return RX_DROP_UNUSABLE;
127 data_len -= MICHAEL_MIC_LEN;
130 authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
134 key = &rx->key->conf.key[authenticator ? ALG_TKIP_TEMP_AUTH_RX_MIC_KEY :
135 ALG_TKIP_TEMP_AUTH_TX_MIC_KEY];
136 michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
137 if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) {
138 if (!(rx->flags & IEEE80211_RX_RA_MATCH))
139 return RX_DROP_UNUSABLE;
141 printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from "
142 "%s\n", rx->dev->name, print_mac(mac, sa));
144 mac80211_ev_michael_mic_failure(rx->dev, rx->key->conf.keyidx,
146 return RX_DROP_UNUSABLE;
149 /* remove Michael MIC from payload */
150 skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
152 /* update IV in key information to be able to detect replays */
153 rx->key->u.tkip.rx[rx->queue].iv32 = rx->tkip_iv32;
154 rx->key->u.tkip.rx[rx->queue].iv16 = rx->tkip_iv16;
160 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
162 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
163 struct ieee80211_key *key = tx->key;
164 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
169 info->control.icv_len = TKIP_ICV_LEN;
170 info->control.iv_len = TKIP_IV_LEN;
172 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
173 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
174 /* hwaccel - with no need for preallocated room for IV/ICV */
175 info->control.hw_key = &tx->key->conf;
179 hdrlen = ieee80211_hdrlen(hdr->frame_control);
180 len = skb->len - hdrlen;
182 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
187 if (WARN_ON(skb_tailroom(skb) < tail ||
188 skb_headroom(skb) < TKIP_IV_LEN))
191 pos = skb_push(skb, TKIP_IV_LEN);
192 memmove(pos, pos + TKIP_IV_LEN, hdrlen);
195 /* Increase IV for the frame */
196 key->u.tkip.tx.iv16++;
197 if (key->u.tkip.tx.iv16 == 0)
198 key->u.tkip.tx.iv32++;
200 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
201 /* hwaccel - with preallocated room for IV */
202 ieee80211_tkip_add_iv(pos, key, key->u.tkip.tx.iv16);
204 info->control.hw_key = &tx->key->conf;
208 /* Add room for ICV */
209 skb_put(skb, TKIP_ICV_LEN);
211 hdr = (struct ieee80211_hdr *) skb->data;
212 ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
213 key, pos, len, hdr->addr2);
219 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
221 struct sk_buff *skb = tx->skb;
223 ieee80211_tx_set_protected(tx);
225 if (tkip_encrypt_skb(tx, skb) < 0)
228 if (tx->extra_frag) {
230 for (i = 0; i < tx->num_extra_frag; i++) {
231 if (tkip_encrypt_skb(tx, tx->extra_frag[i]) < 0)
241 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
243 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
244 int hdrlen, res, hwaccel = 0, wpa_test = 0;
245 struct ieee80211_key *key = rx->key;
246 struct sk_buff *skb = rx->skb;
247 DECLARE_MAC_BUF(mac);
249 hdrlen = ieee80211_hdrlen(hdr->frame_control);
251 if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
254 if (!rx->sta || skb->len - hdrlen < 12)
255 return RX_DROP_UNUSABLE;
257 if (rx->status->flag & RX_FLAG_DECRYPTED) {
258 if (rx->status->flag & RX_FLAG_IV_STRIPPED) {
260 * Hardware took care of all processing, including
261 * replay protection, and stripped the ICV/IV so
262 * we cannot do any checks here.
267 /* let TKIP code verify IV, but skip decryption */
271 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
272 key, skb->data + hdrlen,
273 skb->len - hdrlen, rx->sta->addr,
274 hdr->addr1, hwaccel, rx->queue,
277 if (res != TKIP_DECRYPT_OK || wpa_test) {
278 #ifdef CONFIG_MAC80211_DEBUG
280 printk(KERN_DEBUG "%s: TKIP decrypt failed for RX "
281 "frame from %s (res=%d)\n", rx->dev->name,
282 print_mac(mac, rx->sta->addr), res);
283 #endif /* CONFIG_MAC80211_DEBUG */
284 return RX_DROP_UNUSABLE;
288 skb_trim(skb, skb->len - TKIP_ICV_LEN);
291 memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
292 skb_pull(skb, TKIP_IV_LEN);
298 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
302 int a4_included, qos_included;
303 u8 qos_tid, *fc_pos, *data, *sa, *da;
306 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
308 fc_pos = (u8 *) &hdr->frame_control;
309 fc = fc_pos[0] ^ (fc_pos[1] << 8);
310 a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
311 (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
313 ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len);
314 data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0);
315 if (qos_tid & 0x80) {
320 /* First block, b_0 */
322 b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
323 /* Nonce: QoS Priority | A2 | PN */
325 memcpy(&b_0[2], hdr->addr2, 6);
326 memcpy(&b_0[8], pn, CCMP_PN_LEN);
328 b_0[14] = (data_len >> 8) & 0xff;
329 b_0[15] = data_len & 0xff;
332 /* AAD (extra authenticate-only data) / masked 802.11 header
333 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
335 len_a = a4_included ? 28 : 22;
339 aad[0] = 0; /* (len_a >> 8) & 0xff; */
340 aad[1] = len_a & 0xff;
341 /* Mask FC: zero subtype b4 b5 b6 */
342 aad[2] = fc_pos[0] & ~(BIT(4) | BIT(5) | BIT(6));
343 /* Retry, PwrMgt, MoreData; set Protected */
344 aad[3] = (fc_pos[1] & ~(BIT(3) | BIT(4) | BIT(5))) | BIT(6);
345 memcpy(&aad[4], &hdr->addr1, 18);
347 /* Mask Seq#, leave Frag# */
348 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
351 memcpy(&aad[24], hdr->addr4, 6);
355 memset(&aad[24], 0, 8);
357 u8 *dpos = &aad[a4_included ? 30 : 24];
359 /* Mask QoS Control field */
366 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
371 hdr[3] = 0x20 | (key_id << 6);
379 static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr)
387 return (hdr[3] >> 6) & 0x03;
391 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
393 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
394 struct ieee80211_key *key = tx->key;
395 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
396 int hdrlen, len, tail;
397 u8 *pos, *pn, *b_0, *aad, *scratch;
400 info->control.icv_len = CCMP_MIC_LEN;
401 info->control.iv_len = CCMP_HDR_LEN;
403 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
404 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
405 /* hwaccel - with no need for preallocated room for CCMP "
406 * header or MIC fields */
407 info->control.hw_key = &tx->key->conf;
411 scratch = key->u.ccmp.tx_crypto_buf;
412 b_0 = scratch + 3 * AES_BLOCK_LEN;
413 aad = scratch + 4 * AES_BLOCK_LEN;
415 hdrlen = ieee80211_hdrlen(hdr->frame_control);
416 len = skb->len - hdrlen;
418 if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
423 if (WARN_ON(skb_tailroom(skb) < tail ||
424 skb_headroom(skb) < CCMP_HDR_LEN))
427 pos = skb_push(skb, CCMP_HDR_LEN);
428 memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
429 hdr = (struct ieee80211_hdr *) pos;
433 pn = key->u.ccmp.tx_pn;
435 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
441 ccmp_pn2hdr(pos, pn, key->conf.keyidx);
443 if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
444 /* hwaccel - with preallocated room for CCMP header */
445 info->control.hw_key = &tx->key->conf;
450 ccmp_special_blocks(skb, pn, b_0, aad, 0);
451 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, b_0, aad, pos, len,
452 pos, skb_put(skb, CCMP_MIC_LEN));
459 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx)
461 struct sk_buff *skb = tx->skb;
463 ieee80211_tx_set_protected(tx);
465 if (ccmp_encrypt_skb(tx, skb) < 0)
468 if (tx->extra_frag) {
470 for (i = 0; i < tx->num_extra_frag; i++) {
471 if (ccmp_encrypt_skb(tx, tx->extra_frag[i]) < 0)
481 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx)
483 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
485 struct ieee80211_key *key = rx->key;
486 struct sk_buff *skb = rx->skb;
489 DECLARE_MAC_BUF(mac);
491 hdrlen = ieee80211_hdrlen(hdr->frame_control);
493 if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
496 data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
497 if (!rx->sta || data_len < 0)
498 return RX_DROP_UNUSABLE;
500 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
501 (rx->status->flag & RX_FLAG_IV_STRIPPED))
504 (void) ccmp_hdr2pn(pn, skb->data + hdrlen);
506 if (memcmp(pn, key->u.ccmp.rx_pn[rx->queue], CCMP_PN_LEN) <= 0) {
507 #ifdef CONFIG_MAC80211_DEBUG
508 u8 *ppn = key->u.ccmp.rx_pn[rx->queue];
510 printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from "
511 "%s (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN "
512 "%02x%02x%02x%02x%02x%02x)\n", rx->dev->name,
513 print_mac(mac, rx->sta->addr),
514 pn[0], pn[1], pn[2], pn[3], pn[4], pn[5],
515 ppn[0], ppn[1], ppn[2], ppn[3], ppn[4], ppn[5]);
516 #endif /* CONFIG_MAC80211_DEBUG */
517 key->u.ccmp.replays++;
518 return RX_DROP_UNUSABLE;
521 if (!(rx->status->flag & RX_FLAG_DECRYPTED)) {
522 /* hardware didn't decrypt/verify MIC */
523 u8 *scratch, *b_0, *aad;
525 scratch = key->u.ccmp.rx_crypto_buf;
526 b_0 = scratch + 3 * AES_BLOCK_LEN;
527 aad = scratch + 4 * AES_BLOCK_LEN;
529 ccmp_special_blocks(skb, pn, b_0, aad, 1);
531 if (ieee80211_aes_ccm_decrypt(
532 key->u.ccmp.tfm, scratch, b_0, aad,
533 skb->data + hdrlen + CCMP_HDR_LEN, data_len,
534 skb->data + skb->len - CCMP_MIC_LEN,
535 skb->data + hdrlen + CCMP_HDR_LEN)) {
536 #ifdef CONFIG_MAC80211_DEBUG
538 printk(KERN_DEBUG "%s: CCMP decrypt failed "
539 "for RX frame from %s\n", rx->dev->name,
540 print_mac(mac, rx->sta->addr));
541 #endif /* CONFIG_MAC80211_DEBUG */
542 return RX_DROP_UNUSABLE;
546 memcpy(key->u.ccmp.rx_pn[rx->queue], pn, CCMP_PN_LEN);
548 /* Remove CCMP header and MIC */
549 skb_trim(skb, skb->len - CCMP_MIC_LEN);
550 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
551 skb_pull(skb, CCMP_HDR_LEN);