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;
31 hdr = (struct ieee80211_hdr *) skb->data;
32 fc = le16_to_cpu(hdr->frame_control);
35 if ((fc & (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) ==
36 (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
40 } else if (fc & IEEE80211_FCTL_FROMDS) {
43 } else if (fc & IEEE80211_FCTL_TODS) {
54 *data = skb->data + hdrlen;
55 *data_len = skb->len - hdrlen;
57 a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
58 (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
59 if ((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
60 fc & IEEE80211_STYPE_QOS_DATA) {
61 pos = (u8 *) &hdr->addr4;
64 *qos_tid = pos[0] & 0x0f;
65 *qos_tid |= 0x80; /* qos_included flag */
69 return skb->len < hdrlen ? -1 : 0;
74 ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
76 u8 *data, *sa, *da, *key, *mic, qos_tid;
79 struct sk_buff *skb = tx->skb;
86 if (!tx->key || tx->key->conf.alg != ALG_TKIP || skb->len < 24 ||
87 !WLAN_FC_DATA_PRESENT(fc))
90 if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len))
93 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
94 !(tx->flags & IEEE80211_TX_FRAGMENTED) &&
95 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) &&
97 /* hwaccel - with no need for preallocated room for Michael MIC
102 tail = MICHAEL_MIC_LEN;
103 if (!(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
104 tail += TKIP_ICV_LEN;
106 if (WARN_ON(skb_tailroom(skb) < tail ||
107 skb_headroom(skb) < TKIP_IV_LEN))
111 authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
115 key = &tx->key->conf.key[authenticator ? ALG_TKIP_TEMP_AUTH_TX_MIC_KEY :
116 ALG_TKIP_TEMP_AUTH_RX_MIC_KEY];
117 mic = skb_put(skb, MICHAEL_MIC_LEN);
118 michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
125 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
127 u8 *data, *sa, *da, *key = NULL, qos_tid;
130 u8 mic[MICHAEL_MIC_LEN];
131 struct sk_buff *skb = rx->skb;
132 int authenticator = 1, wpa_test = 0;
133 DECLARE_MAC_BUF(mac);
138 * No way to verify the MIC if the hardware stripped it
140 if (rx->status->flag & RX_FLAG_MMIC_STRIPPED)
143 if (!rx->key || rx->key->conf.alg != ALG_TKIP ||
144 !(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc))
147 if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)
148 || data_len < MICHAEL_MIC_LEN)
149 return RX_DROP_UNUSABLE;
151 data_len -= MICHAEL_MIC_LEN;
154 authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
158 key = &rx->key->conf.key[authenticator ? ALG_TKIP_TEMP_AUTH_RX_MIC_KEY :
159 ALG_TKIP_TEMP_AUTH_TX_MIC_KEY];
160 michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
161 if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) {
162 if (!(rx->flags & IEEE80211_RX_RA_MATCH))
163 return RX_DROP_UNUSABLE;
165 printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from "
166 "%s\n", rx->dev->name, print_mac(mac, sa));
168 mac80211_ev_michael_mic_failure(rx->dev, rx->key->conf.keyidx,
170 return RX_DROP_UNUSABLE;
173 /* remove Michael MIC from payload */
174 skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
176 /* update IV in key information to be able to detect replays */
177 rx->key->u.tkip.rx[rx->queue].iv32 = rx->tkip_iv32;
178 rx->key->u.tkip.rx[rx->queue].iv16 = rx->tkip_iv16;
184 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
186 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
187 struct ieee80211_key *key = tx->key;
188 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
189 int hdrlen, len, tail;
193 info->control.icv_len = TKIP_ICV_LEN;
194 info->control.iv_len = TKIP_IV_LEN;
196 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
197 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
198 /* hwaccel - with no need for preallocated room for IV/ICV */
199 info->control.hw_key = &tx->key->conf;
203 fc = le16_to_cpu(hdr->frame_control);
204 hdrlen = ieee80211_get_hdrlen(fc);
205 len = skb->len - hdrlen;
207 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
212 if (WARN_ON(skb_tailroom(skb) < tail ||
213 skb_headroom(skb) < TKIP_IV_LEN))
216 pos = skb_push(skb, TKIP_IV_LEN);
217 memmove(pos, pos + TKIP_IV_LEN, hdrlen);
220 /* Increase IV for the frame */
221 key->u.tkip.tx.iv16++;
222 if (key->u.tkip.tx.iv16 == 0)
223 key->u.tkip.tx.iv32++;
225 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
226 hdr = (struct ieee80211_hdr *)skb->data;
228 /* hwaccel - with preallocated room for IV */
229 ieee80211_tkip_add_iv(pos, key,
230 (u8) (key->u.tkip.tx.iv16 >> 8),
231 (u8) (((key->u.tkip.tx.iv16 >> 8) | 0x20) &
233 (u8) key->u.tkip.tx.iv16);
235 info->control.hw_key = &tx->key->conf;
239 /* Add room for ICV */
240 skb_put(skb, TKIP_ICV_LEN);
242 hdr = (struct ieee80211_hdr *) skb->data;
243 ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
244 key, pos, len, hdr->addr2);
250 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
252 struct sk_buff *skb = tx->skb;
254 ieee80211_tx_set_protected(tx);
256 if (tkip_encrypt_skb(tx, skb) < 0)
259 if (tx->extra_frag) {
261 for (i = 0; i < tx->num_extra_frag; i++) {
262 if (tkip_encrypt_skb(tx, tx->extra_frag[i]) < 0)
272 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
274 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
276 int hdrlen, res, hwaccel = 0, wpa_test = 0;
277 struct ieee80211_key *key = rx->key;
278 struct sk_buff *skb = rx->skb;
279 DECLARE_MAC_BUF(mac);
281 fc = le16_to_cpu(hdr->frame_control);
282 hdrlen = ieee80211_get_hdrlen(fc);
284 if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
287 if (!rx->sta || skb->len - hdrlen < 12)
288 return RX_DROP_UNUSABLE;
290 if (rx->status->flag & RX_FLAG_DECRYPTED) {
291 if (rx->status->flag & RX_FLAG_IV_STRIPPED) {
293 * Hardware took care of all processing, including
294 * replay protection, and stripped the ICV/IV so
295 * we cannot do any checks here.
300 /* let TKIP code verify IV, but skip decryption */
304 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
305 key, skb->data + hdrlen,
306 skb->len - hdrlen, rx->sta->addr,
307 hdr->addr1, hwaccel, rx->queue,
310 if (res != TKIP_DECRYPT_OK || wpa_test) {
311 #ifdef CONFIG_MAC80211_DEBUG
313 printk(KERN_DEBUG "%s: TKIP decrypt failed for RX "
314 "frame from %s (res=%d)\n", rx->dev->name,
315 print_mac(mac, rx->sta->addr), res);
316 #endif /* CONFIG_MAC80211_DEBUG */
317 return RX_DROP_UNUSABLE;
321 skb_trim(skb, skb->len - TKIP_ICV_LEN);
324 memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
325 skb_pull(skb, TKIP_IV_LEN);
331 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
335 int a4_included, qos_included;
336 u8 qos_tid, *fc_pos, *data, *sa, *da;
339 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
341 fc_pos = (u8 *) &hdr->frame_control;
342 fc = fc_pos[0] ^ (fc_pos[1] << 8);
343 a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
344 (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
346 ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len);
347 data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0);
348 if (qos_tid & 0x80) {
353 /* First block, b_0 */
355 b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
356 /* Nonce: QoS Priority | A2 | PN */
358 memcpy(&b_0[2], hdr->addr2, 6);
359 memcpy(&b_0[8], pn, CCMP_PN_LEN);
361 b_0[14] = (data_len >> 8) & 0xff;
362 b_0[15] = data_len & 0xff;
365 /* AAD (extra authenticate-only data) / masked 802.11 header
366 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
368 len_a = a4_included ? 28 : 22;
372 aad[0] = 0; /* (len_a >> 8) & 0xff; */
373 aad[1] = len_a & 0xff;
374 /* Mask FC: zero subtype b4 b5 b6 */
375 aad[2] = fc_pos[0] & ~(BIT(4) | BIT(5) | BIT(6));
376 /* Retry, PwrMgt, MoreData; set Protected */
377 aad[3] = (fc_pos[1] & ~(BIT(3) | BIT(4) | BIT(5))) | BIT(6);
378 memcpy(&aad[4], &hdr->addr1, 18);
380 /* Mask Seq#, leave Frag# */
381 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
384 memcpy(&aad[24], hdr->addr4, 6);
388 memset(&aad[24], 0, 8);
390 u8 *dpos = &aad[a4_included ? 30 : 24];
392 /* Mask QoS Control field */
399 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
404 hdr[3] = 0x20 | (key_id << 6);
412 static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr)
420 return (hdr[3] >> 6) & 0x03;
424 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
426 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
427 struct ieee80211_key *key = tx->key;
428 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
429 int hdrlen, len, tail;
431 u8 *pos, *pn, *b_0, *aad, *scratch;
434 info->control.icv_len = CCMP_MIC_LEN;
435 info->control.iv_len = CCMP_HDR_LEN;
437 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
438 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
439 /* hwaccel - with no need for preallocated room for CCMP "
440 * header or MIC fields */
441 info->control.hw_key = &tx->key->conf;
445 scratch = key->u.ccmp.tx_crypto_buf;
446 b_0 = scratch + 3 * AES_BLOCK_LEN;
447 aad = scratch + 4 * AES_BLOCK_LEN;
449 fc = le16_to_cpu(hdr->frame_control);
450 hdrlen = ieee80211_get_hdrlen(fc);
451 len = skb->len - hdrlen;
453 if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
458 if (WARN_ON(skb_tailroom(skb) < tail ||
459 skb_headroom(skb) < CCMP_HDR_LEN))
462 pos = skb_push(skb, CCMP_HDR_LEN);
463 memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
464 hdr = (struct ieee80211_hdr *) pos;
468 pn = key->u.ccmp.tx_pn;
470 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
476 ccmp_pn2hdr(pos, pn, key->conf.keyidx);
478 if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
479 /* hwaccel - with preallocated room for CCMP header */
480 info->control.hw_key = &tx->key->conf;
485 ccmp_special_blocks(skb, pn, b_0, aad, 0);
486 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, b_0, aad, pos, len,
487 pos, skb_put(skb, CCMP_MIC_LEN));
494 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx)
496 struct sk_buff *skb = tx->skb;
498 ieee80211_tx_set_protected(tx);
500 if (ccmp_encrypt_skb(tx, skb) < 0)
503 if (tx->extra_frag) {
505 for (i = 0; i < tx->num_extra_frag; i++) {
506 if (ccmp_encrypt_skb(tx, tx->extra_frag[i]) < 0)
516 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx)
518 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
521 struct ieee80211_key *key = rx->key;
522 struct sk_buff *skb = rx->skb;
525 DECLARE_MAC_BUF(mac);
527 fc = le16_to_cpu(hdr->frame_control);
528 hdrlen = ieee80211_get_hdrlen(fc);
530 if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
533 data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
534 if (!rx->sta || data_len < 0)
535 return RX_DROP_UNUSABLE;
537 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
538 (rx->status->flag & RX_FLAG_IV_STRIPPED))
541 (void) ccmp_hdr2pn(pn, skb->data + hdrlen);
543 if (memcmp(pn, key->u.ccmp.rx_pn[rx->queue], CCMP_PN_LEN) <= 0) {
544 #ifdef CONFIG_MAC80211_DEBUG
545 u8 *ppn = key->u.ccmp.rx_pn[rx->queue];
547 printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from "
548 "%s (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN "
549 "%02x%02x%02x%02x%02x%02x)\n", rx->dev->name,
550 print_mac(mac, rx->sta->addr),
551 pn[0], pn[1], pn[2], pn[3], pn[4], pn[5],
552 ppn[0], ppn[1], ppn[2], ppn[3], ppn[4], ppn[5]);
553 #endif /* CONFIG_MAC80211_DEBUG */
554 key->u.ccmp.replays++;
555 return RX_DROP_UNUSABLE;
558 if (!(rx->status->flag & RX_FLAG_DECRYPTED)) {
559 /* hardware didn't decrypt/verify MIC */
560 u8 *scratch, *b_0, *aad;
562 scratch = key->u.ccmp.rx_crypto_buf;
563 b_0 = scratch + 3 * AES_BLOCK_LEN;
564 aad = scratch + 4 * AES_BLOCK_LEN;
566 ccmp_special_blocks(skb, pn, b_0, aad, 1);
568 if (ieee80211_aes_ccm_decrypt(
569 key->u.ccmp.tfm, scratch, b_0, aad,
570 skb->data + hdrlen + CCMP_HDR_LEN, data_len,
571 skb->data + skb->len - CCMP_MIC_LEN,
572 skb->data + hdrlen + CCMP_HDR_LEN)) {
573 #ifdef CONFIG_MAC80211_DEBUG
575 printk(KERN_DEBUG "%s: CCMP decrypt failed "
576 "for RX frame from %s\n", rx->dev->name,
577 print_mac(mac, rx->sta->addr));
578 #endif /* CONFIG_MAC80211_DEBUG */
579 return RX_DROP_UNUSABLE;
583 memcpy(key->u.ccmp.rx_pn[rx->queue], pn, CCMP_PN_LEN);
585 /* Remove CCMP header and MIC */
586 skb_trim(skb, skb->len - CCMP_MIC_LEN);
587 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
588 skb_pull(skb, CCMP_HDR_LEN);