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_txrx_data *tx)
76 u8 *data, *sa, *da, *key, *mic, qos_tid;
79 struct sk_buff *skb = tx->skb;
85 if (!tx->key || tx->key->alg != ALG_TKIP || skb->len < 24 ||
86 !WLAN_FC_DATA_PRESENT(fc))
89 if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len))
92 if (!tx->key->force_sw_encrypt &&
94 !(tx->local->hw.flags & IEEE80211_HW_TKIP_INCLUDE_MMIC) &&
96 /* hwaccel - with no need for preallocated room for Michael MIC
101 if (skb_tailroom(skb) < MICHAEL_MIC_LEN) {
102 I802_DEBUG_INC(tx->local->tx_expand_skb_head);
103 if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN,
104 MICHAEL_MIC_LEN + TKIP_ICV_LEN,
106 printk(KERN_DEBUG "%s: failed to allocate more memory "
107 "for Michael MIC\n", tx->dev->name);
113 authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
117 key = &tx->key->key[authenticator ? ALG_TKIP_TEMP_AUTH_TX_MIC_KEY :
118 ALG_TKIP_TEMP_AUTH_RX_MIC_KEY];
119 mic = skb_put(skb, MICHAEL_MIC_LEN);
120 michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
122 return TXRX_CONTINUE;
126 ieee80211_txrx_result
127 ieee80211_rx_h_michael_mic_verify(struct ieee80211_txrx_data *rx)
129 u8 *data, *sa, *da, *key = NULL, qos_tid;
132 u8 mic[MICHAEL_MIC_LEN];
133 struct sk_buff *skb = rx->skb;
134 int authenticator = 1, wpa_test = 0;
139 * No way to verify the MIC if the hardware stripped it
141 if (rx->local->hw.flags & IEEE80211_HW_DEVICE_STRIPS_MIC)
142 return TXRX_CONTINUE;
144 if (!rx->key || rx->key->alg != ALG_TKIP ||
145 !(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc))
146 return TXRX_CONTINUE;
148 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
149 !rx->key->force_sw_encrypt) {
150 if (rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) {
151 if (skb->len < MICHAEL_MIC_LEN)
154 /* Need to verify Michael MIC sometimes in software even when
155 * hwaccel is used. Atheros ar5212: fragmented frames and QoS
157 if (!rx->fragmented && !wpa_test)
161 if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)
162 || data_len < MICHAEL_MIC_LEN)
165 data_len -= MICHAEL_MIC_LEN;
168 authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
172 key = &rx->key->key[authenticator ? ALG_TKIP_TEMP_AUTH_RX_MIC_KEY :
173 ALG_TKIP_TEMP_AUTH_TX_MIC_KEY];
174 michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
175 if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) {
176 if (!rx->u.rx.ra_match)
179 printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from "
180 MAC_FMT "\n", rx->dev->name, MAC_ARG(sa));
182 mac80211_ev_michael_mic_failure(rx->dev, rx->key->keyidx,
188 /* remove Michael MIC from payload */
189 skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
191 return TXRX_CONTINUE;
195 static int tkip_encrypt_skb(struct ieee80211_txrx_data *tx,
196 struct sk_buff *skb, int test)
198 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
199 struct ieee80211_key *key = tx->key;
200 int hdrlen, len, tailneed;
204 fc = le16_to_cpu(hdr->frame_control);
205 hdrlen = ieee80211_get_hdrlen(fc);
206 len = skb->len - hdrlen;
208 tailneed = !tx->key->force_sw_encrypt ? 0 : TKIP_ICV_LEN;
209 if ((skb_headroom(skb) < TKIP_IV_LEN ||
210 skb_tailroom(skb) < tailneed)) {
211 I802_DEBUG_INC(tx->local->tx_expand_skb_head);
212 if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN, tailneed,
217 pos = skb_push(skb, TKIP_IV_LEN);
218 memmove(pos, pos + TKIP_IV_LEN, hdrlen);
221 /* Increase IV for the frame */
223 if (key->u.tkip.iv16 == 0)
226 if (!tx->key->force_sw_encrypt) {
227 u32 flags = tx->local->hw.flags;
228 hdr = (struct ieee80211_hdr *)skb->data;
230 /* hwaccel - with preallocated room for IV */
231 ieee80211_tkip_add_iv(pos, key,
232 (u8) (key->u.tkip.iv16 >> 8),
233 (u8) (((key->u.tkip.iv16 >> 8) | 0x20) &
235 (u8) key->u.tkip.iv16);
237 if (flags & IEEE80211_HW_TKIP_REQ_PHASE2_KEY)
238 ieee80211_tkip_gen_rc4key(key, hdr->addr2,
239 tx->u.tx.control->tkip_key);
240 else if (flags & IEEE80211_HW_TKIP_REQ_PHASE1_KEY) {
241 if (key->u.tkip.iv16 == 0 ||
242 !key->u.tkip.tx_initialized) {
243 ieee80211_tkip_gen_phase1key(key, hdr->addr2,
244 (u16 *)tx->u.tx.control->tkip_key);
245 key->u.tkip.tx_initialized = 1;
246 tx->u.tx.control->flags |=
247 IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY;
249 tx->u.tx.control->flags &=
250 ~IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY;
253 tx->u.tx.control->key_idx = tx->key->hw_key_idx;
257 /* Add room for ICV */
258 skb_put(skb, TKIP_ICV_LEN);
260 hdr = (struct ieee80211_hdr *) skb->data;
261 ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
262 key, pos, len, hdr->addr2);
267 ieee80211_txrx_result
268 ieee80211_tx_h_tkip_encrypt(struct ieee80211_txrx_data *tx)
270 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
272 struct ieee80211_key *key = tx->key;
273 struct sk_buff *skb = tx->skb;
274 int wpa_test = 0, test = 0;
276 fc = le16_to_cpu(hdr->frame_control);
278 if (!key || key->alg != ALG_TKIP || !WLAN_FC_DATA_PRESENT(fc))
279 return TXRX_CONTINUE;
281 tx->u.tx.control->icv_len = TKIP_ICV_LEN;
282 tx->u.tx.control->iv_len = TKIP_IV_LEN;
283 ieee80211_tx_set_iswep(tx);
285 if (!tx->key->force_sw_encrypt &&
286 !(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) &&
288 /* hwaccel - with no need for preallocated room for IV/ICV */
289 tx->u.tx.control->key_idx = tx->key->hw_key_idx;
290 return TXRX_CONTINUE;
293 if (tkip_encrypt_skb(tx, skb, test) < 0)
296 if (tx->u.tx.extra_frag) {
298 for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
299 if (tkip_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
305 return TXRX_CONTINUE;
309 ieee80211_txrx_result
310 ieee80211_rx_h_tkip_decrypt(struct ieee80211_txrx_data *rx)
312 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
314 int hdrlen, res, hwaccel = 0, wpa_test = 0;
315 struct ieee80211_key *key = rx->key;
316 struct sk_buff *skb = rx->skb;
318 fc = le16_to_cpu(hdr->frame_control);
319 hdrlen = ieee80211_get_hdrlen(fc);
321 if (!rx->key || rx->key->alg != ALG_TKIP ||
322 !(rx->fc & IEEE80211_FCTL_PROTECTED) ||
323 (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
324 return TXRX_CONTINUE;
326 if (!rx->sta || skb->len - hdrlen < 12)
329 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
330 !rx->key->force_sw_encrypt) {
331 if (!(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) {
332 /* Hardware takes care of all processing, including
333 * replay protection, so no need to continue here. */
334 return TXRX_CONTINUE;
337 /* let TKIP code verify IV, but skip decryption */
341 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
342 key, skb->data + hdrlen,
343 skb->len - hdrlen, rx->sta->addr,
344 hwaccel, rx->u.rx.queue);
345 if (res != TKIP_DECRYPT_OK || wpa_test) {
346 printk(KERN_DEBUG "%s: TKIP decrypt failed for RX frame from "
347 MAC_FMT " (res=%d)\n",
348 rx->dev->name, MAC_ARG(rx->sta->addr), res);
353 skb_trim(skb, skb->len - TKIP_ICV_LEN);
356 memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
357 skb_pull(skb, TKIP_IV_LEN);
359 return TXRX_CONTINUE;
363 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
367 int a4_included, qos_included;
368 u8 qos_tid, *fc_pos, *data, *sa, *da;
371 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
373 fc_pos = (u8 *) &hdr->frame_control;
374 fc = fc_pos[0] ^ (fc_pos[1] << 8);
375 a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
376 (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
378 ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len);
379 data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0);
380 if (qos_tid & 0x80) {
385 /* First block, b_0 */
387 b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
388 /* Nonce: QoS Priority | A2 | PN */
390 memcpy(&b_0[2], hdr->addr2, 6);
391 memcpy(&b_0[8], pn, CCMP_PN_LEN);
393 b_0[14] = (data_len >> 8) & 0xff;
394 b_0[15] = data_len & 0xff;
397 /* AAD (extra authenticate-only data) / masked 802.11 header
398 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
400 len_a = a4_included ? 28 : 22;
404 aad[0] = 0; /* (len_a >> 8) & 0xff; */
405 aad[1] = len_a & 0xff;
406 /* Mask FC: zero subtype b4 b5 b6 */
407 aad[2] = fc_pos[0] & ~(BIT(4) | BIT(5) | BIT(6));
408 /* Retry, PwrMgt, MoreData; set Protected */
409 aad[3] = (fc_pos[1] & ~(BIT(3) | BIT(4) | BIT(5))) | BIT(6);
410 memcpy(&aad[4], &hdr->addr1, 18);
412 /* Mask Seq#, leave Frag# */
413 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
416 memcpy(&aad[24], hdr->addr4, 6);
420 memset(&aad[24], 0, 8);
422 u8 *dpos = &aad[a4_included ? 30 : 24];
424 /* Mask QoS Control field */
431 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
436 hdr[3] = 0x20 | (key_id << 6);
444 static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr)
452 return (hdr[3] >> 6) & 0x03;
456 static int ccmp_encrypt_skb(struct ieee80211_txrx_data *tx,
457 struct sk_buff *skb, int test)
459 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
460 struct ieee80211_key *key = tx->key;
461 int hdrlen, len, tailneed;
463 u8 *pos, *pn, *b_0, *aad, *scratch;
466 scratch = key->u.ccmp.tx_crypto_buf;
467 b_0 = scratch + 3 * AES_BLOCK_LEN;
468 aad = scratch + 4 * AES_BLOCK_LEN;
470 fc = le16_to_cpu(hdr->frame_control);
471 hdrlen = ieee80211_get_hdrlen(fc);
472 len = skb->len - hdrlen;
474 tailneed = !key->force_sw_encrypt ? 0 : CCMP_MIC_LEN;
476 if ((skb_headroom(skb) < CCMP_HDR_LEN ||
477 skb_tailroom(skb) < tailneed)) {
478 I802_DEBUG_INC(tx->local->tx_expand_skb_head);
479 if (unlikely(pskb_expand_head(skb, CCMP_HDR_LEN, tailneed,
484 pos = skb_push(skb, CCMP_HDR_LEN);
485 memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
486 hdr = (struct ieee80211_hdr *) pos;
490 pn = key->u.ccmp.tx_pn;
492 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
498 ccmp_pn2hdr(pos, pn, key->keyidx);
500 if (!key->force_sw_encrypt) {
501 /* hwaccel - with preallocated room for CCMP header */
502 tx->u.tx.control->key_idx = key->hw_key_idx;
507 ccmp_special_blocks(skb, pn, b_0, aad, 0);
508 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, b_0, aad, pos, len,
509 pos, skb_put(skb, CCMP_MIC_LEN));
515 ieee80211_txrx_result
516 ieee80211_tx_h_ccmp_encrypt(struct ieee80211_txrx_data *tx)
518 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
519 struct ieee80211_key *key = tx->key;
521 struct sk_buff *skb = tx->skb;
524 fc = le16_to_cpu(hdr->frame_control);
526 if (!key || key->alg != ALG_CCMP || !WLAN_FC_DATA_PRESENT(fc))
527 return TXRX_CONTINUE;
529 tx->u.tx.control->icv_len = CCMP_MIC_LEN;
530 tx->u.tx.control->iv_len = CCMP_HDR_LEN;
531 ieee80211_tx_set_iswep(tx);
533 if (!tx->key->force_sw_encrypt &&
534 !(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) {
535 /* hwaccel - with no need for preallocated room for CCMP "
536 * header or MIC fields */
537 tx->u.tx.control->key_idx = tx->key->hw_key_idx;
538 return TXRX_CONTINUE;
541 if (ccmp_encrypt_skb(tx, skb, test) < 0)
544 if (tx->u.tx.extra_frag) {
547 for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
548 if (ccmp_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
554 return TXRX_CONTINUE;
558 ieee80211_txrx_result
559 ieee80211_rx_h_ccmp_decrypt(struct ieee80211_txrx_data *rx)
561 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
564 struct ieee80211_key *key = rx->key;
565 struct sk_buff *skb = rx->skb;
569 fc = le16_to_cpu(hdr->frame_control);
570 hdrlen = ieee80211_get_hdrlen(fc);
572 if (!key || key->alg != ALG_CCMP ||
573 !(rx->fc & IEEE80211_FCTL_PROTECTED) ||
574 (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
575 return TXRX_CONTINUE;
577 data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
578 if (!rx->sta || data_len < 0)
581 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
582 !key->force_sw_encrypt &&
583 !(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV))
584 return TXRX_CONTINUE;
586 (void) ccmp_hdr2pn(pn, skb->data + hdrlen);
588 if (memcmp(pn, key->u.ccmp.rx_pn[rx->u.rx.queue], CCMP_PN_LEN) <= 0) {
589 #ifdef CONFIG_MAC80211_DEBUG
590 u8 *ppn = key->u.ccmp.rx_pn[rx->u.rx.queue];
591 printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from "
592 MAC_FMT " (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN "
593 "%02x%02x%02x%02x%02x%02x)\n", rx->dev->name,
594 MAC_ARG(rx->sta->addr),
595 pn[0], pn[1], pn[2], pn[3], pn[4], pn[5],
596 ppn[0], ppn[1], ppn[2], ppn[3], ppn[4], ppn[5]);
597 #endif /* CONFIG_MAC80211_DEBUG */
598 key->u.ccmp.replays++;
602 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
603 !key->force_sw_encrypt) {
604 /* hwaccel has already decrypted frame and verified MIC */
606 u8 *scratch, *b_0, *aad;
608 scratch = key->u.ccmp.rx_crypto_buf;
609 b_0 = scratch + 3 * AES_BLOCK_LEN;
610 aad = scratch + 4 * AES_BLOCK_LEN;
612 ccmp_special_blocks(skb, pn, b_0, aad, 1);
614 if (ieee80211_aes_ccm_decrypt(
615 key->u.ccmp.tfm, scratch, b_0, aad,
616 skb->data + hdrlen + CCMP_HDR_LEN, data_len,
617 skb->data + skb->len - CCMP_MIC_LEN,
618 skb->data + hdrlen + CCMP_HDR_LEN)) {
619 printk(KERN_DEBUG "%s: CCMP decrypt failed for RX "
620 "frame from " MAC_FMT "\n", rx->dev->name,
621 MAC_ARG(rx->sta->addr));
626 memcpy(key->u.ccmp.rx_pn[rx->u.rx.queue], pn, CCMP_PN_LEN);
628 /* Remove CCMP header and MIC */
629 skb_trim(skb, skb->len - CCMP_MIC_LEN);
630 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
631 skb_pull(skb, CCMP_HDR_LEN);
633 return TXRX_CONTINUE;