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->conf.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->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
93 !(tx->flags & IEEE80211_TXRXD_FRAGMENTED) &&
94 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_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->conf.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->u.rx.status->flag & RX_FLAG_MMIC_STRIPPED)
142 return TXRX_CONTINUE;
144 if (!rx->key || rx->key->conf.alg != ALG_TKIP ||
145 !(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc))
146 return TXRX_CONTINUE;
148 if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)
149 || data_len < MICHAEL_MIC_LEN)
152 data_len -= MICHAEL_MIC_LEN;
155 authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
159 key = &rx->key->conf.key[authenticator ? ALG_TKIP_TEMP_AUTH_RX_MIC_KEY :
160 ALG_TKIP_TEMP_AUTH_TX_MIC_KEY];
161 michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
162 if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) {
163 if (!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH))
166 printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from "
167 MAC_FMT "\n", rx->dev->name, MAC_ARG(sa));
169 mac80211_ev_michael_mic_failure(rx->dev, rx->key->conf.keyidx,
174 /* remove Michael MIC from payload */
175 skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
177 /* update IV in key information to be able to detect replays */
178 rx->key->u.tkip.iv32_rx[rx->u.rx.queue] = rx->u.rx.tkip_iv32;
179 rx->key->u.tkip.iv16_rx[rx->u.rx.queue] = rx->u.rx.tkip_iv16;
181 return TXRX_CONTINUE;
185 static int tkip_encrypt_skb(struct ieee80211_txrx_data *tx,
186 struct sk_buff *skb, int test)
188 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
189 struct ieee80211_key *key = tx->key;
190 int hdrlen, len, tailneed;
194 fc = le16_to_cpu(hdr->frame_control);
195 hdrlen = ieee80211_get_hdrlen(fc);
196 len = skb->len - hdrlen;
198 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
201 tailneed = TKIP_ICV_LEN;
203 if ((skb_headroom(skb) < TKIP_IV_LEN ||
204 skb_tailroom(skb) < tailneed)) {
205 I802_DEBUG_INC(tx->local->tx_expand_skb_head);
206 if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN, tailneed,
211 pos = skb_push(skb, TKIP_IV_LEN);
212 memmove(pos, pos + TKIP_IV_LEN, hdrlen);
215 /* Increase IV for the frame */
217 if (key->u.tkip.iv16 == 0)
220 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
221 hdr = (struct ieee80211_hdr *)skb->data;
223 /* hwaccel - with preallocated room for IV */
224 ieee80211_tkip_add_iv(pos, key,
225 (u8) (key->u.tkip.iv16 >> 8),
226 (u8) (((key->u.tkip.iv16 >> 8) | 0x20) &
228 (u8) key->u.tkip.iv16);
230 tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx;
234 /* Add room for ICV */
235 skb_put(skb, TKIP_ICV_LEN);
237 hdr = (struct ieee80211_hdr *) skb->data;
238 ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
239 key, pos, len, hdr->addr2);
244 ieee80211_txrx_result
245 ieee80211_crypto_tkip_encrypt(struct ieee80211_txrx_data *tx)
247 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
249 struct sk_buff *skb = tx->skb;
250 int wpa_test = 0, test = 0;
252 fc = le16_to_cpu(hdr->frame_control);
254 if (!WLAN_FC_DATA_PRESENT(fc))
255 return TXRX_CONTINUE;
257 tx->u.tx.control->icv_len = TKIP_ICV_LEN;
258 tx->u.tx.control->iv_len = TKIP_IV_LEN;
259 ieee80211_tx_set_iswep(tx);
261 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
262 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
264 /* hwaccel - with no need for preallocated room for IV/ICV */
265 tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx;
266 return TXRX_CONTINUE;
269 if (tkip_encrypt_skb(tx, skb, test) < 0)
272 if (tx->u.tx.extra_frag) {
274 for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
275 if (tkip_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
281 return TXRX_CONTINUE;
285 ieee80211_txrx_result
286 ieee80211_crypto_tkip_decrypt(struct ieee80211_txrx_data *rx)
288 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
290 int hdrlen, res, hwaccel = 0, wpa_test = 0;
291 struct ieee80211_key *key = rx->key;
292 struct sk_buff *skb = rx->skb;
294 fc = le16_to_cpu(hdr->frame_control);
295 hdrlen = ieee80211_get_hdrlen(fc);
297 if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
298 return TXRX_CONTINUE;
300 if (!rx->sta || skb->len - hdrlen < 12)
303 if (rx->u.rx.status->flag & RX_FLAG_DECRYPTED) {
304 if (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED) {
306 * Hardware took care of all processing, including
307 * replay protection, and stripped the ICV/IV so
308 * we cannot do any checks here.
310 return TXRX_CONTINUE;
313 /* let TKIP code verify IV, but skip decryption */
317 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
318 key, skb->data + hdrlen,
319 skb->len - hdrlen, rx->sta->addr,
320 hwaccel, rx->u.rx.queue,
322 &rx->u.rx.tkip_iv16);
323 if (res != TKIP_DECRYPT_OK || wpa_test) {
324 printk(KERN_DEBUG "%s: TKIP decrypt failed for RX frame from "
325 MAC_FMT " (res=%d)\n",
326 rx->dev->name, MAC_ARG(rx->sta->addr), res);
331 skb_trim(skb, skb->len - TKIP_ICV_LEN);
334 memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
335 skb_pull(skb, TKIP_IV_LEN);
337 return TXRX_CONTINUE;
341 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
345 int a4_included, qos_included;
346 u8 qos_tid, *fc_pos, *data, *sa, *da;
349 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
351 fc_pos = (u8 *) &hdr->frame_control;
352 fc = fc_pos[0] ^ (fc_pos[1] << 8);
353 a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
354 (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
356 ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len);
357 data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0);
358 if (qos_tid & 0x80) {
363 /* First block, b_0 */
365 b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
366 /* Nonce: QoS Priority | A2 | PN */
368 memcpy(&b_0[2], hdr->addr2, 6);
369 memcpy(&b_0[8], pn, CCMP_PN_LEN);
371 b_0[14] = (data_len >> 8) & 0xff;
372 b_0[15] = data_len & 0xff;
375 /* AAD (extra authenticate-only data) / masked 802.11 header
376 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
378 len_a = a4_included ? 28 : 22;
382 aad[0] = 0; /* (len_a >> 8) & 0xff; */
383 aad[1] = len_a & 0xff;
384 /* Mask FC: zero subtype b4 b5 b6 */
385 aad[2] = fc_pos[0] & ~(BIT(4) | BIT(5) | BIT(6));
386 /* Retry, PwrMgt, MoreData; set Protected */
387 aad[3] = (fc_pos[1] & ~(BIT(3) | BIT(4) | BIT(5))) | BIT(6);
388 memcpy(&aad[4], &hdr->addr1, 18);
390 /* Mask Seq#, leave Frag# */
391 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
394 memcpy(&aad[24], hdr->addr4, 6);
398 memset(&aad[24], 0, 8);
400 u8 *dpos = &aad[a4_included ? 30 : 24];
402 /* Mask QoS Control field */
409 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
414 hdr[3] = 0x20 | (key_id << 6);
422 static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr)
430 return (hdr[3] >> 6) & 0x03;
434 static int ccmp_encrypt_skb(struct ieee80211_txrx_data *tx,
435 struct sk_buff *skb, int test)
437 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
438 struct ieee80211_key *key = tx->key;
439 int hdrlen, len, tailneed;
441 u8 *pos, *pn, *b_0, *aad, *scratch;
444 scratch = key->u.ccmp.tx_crypto_buf;
445 b_0 = scratch + 3 * AES_BLOCK_LEN;
446 aad = scratch + 4 * AES_BLOCK_LEN;
448 fc = le16_to_cpu(hdr->frame_control);
449 hdrlen = ieee80211_get_hdrlen(fc);
450 len = skb->len - hdrlen;
452 if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
455 tailneed = CCMP_MIC_LEN;
457 if ((skb_headroom(skb) < CCMP_HDR_LEN ||
458 skb_tailroom(skb) < tailneed)) {
459 I802_DEBUG_INC(tx->local->tx_expand_skb_head);
460 if (unlikely(pskb_expand_head(skb, CCMP_HDR_LEN, tailneed,
465 pos = skb_push(skb, CCMP_HDR_LEN);
466 memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
467 hdr = (struct ieee80211_hdr *) pos;
471 pn = key->u.ccmp.tx_pn;
473 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
479 ccmp_pn2hdr(pos, pn, key->conf.keyidx);
481 if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
482 /* hwaccel - with preallocated room for CCMP header */
483 tx->u.tx.control->key_idx = key->conf.hw_key_idx;
488 ccmp_special_blocks(skb, pn, b_0, aad, 0);
489 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, b_0, aad, pos, len,
490 pos, skb_put(skb, CCMP_MIC_LEN));
496 ieee80211_txrx_result
497 ieee80211_crypto_ccmp_encrypt(struct ieee80211_txrx_data *tx)
499 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
501 struct sk_buff *skb = tx->skb;
504 fc = le16_to_cpu(hdr->frame_control);
506 if (!WLAN_FC_DATA_PRESENT(fc))
507 return TXRX_CONTINUE;
509 tx->u.tx.control->icv_len = CCMP_MIC_LEN;
510 tx->u.tx.control->iv_len = CCMP_HDR_LEN;
511 ieee80211_tx_set_iswep(tx);
513 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
514 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
515 /* hwaccel - with no need for preallocated room for CCMP "
516 * header or MIC fields */
517 tx->u.tx.control->key_idx = tx->key->conf.hw_key_idx;
518 return TXRX_CONTINUE;
521 if (ccmp_encrypt_skb(tx, skb, test) < 0)
524 if (tx->u.tx.extra_frag) {
526 for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
527 if (ccmp_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
533 return TXRX_CONTINUE;
537 ieee80211_txrx_result
538 ieee80211_crypto_ccmp_decrypt(struct ieee80211_txrx_data *rx)
540 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
543 struct ieee80211_key *key = rx->key;
544 struct sk_buff *skb = rx->skb;
548 fc = le16_to_cpu(hdr->frame_control);
549 hdrlen = ieee80211_get_hdrlen(fc);
551 if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
552 return TXRX_CONTINUE;
554 data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
555 if (!rx->sta || data_len < 0)
558 if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
559 (rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED))
560 return TXRX_CONTINUE;
562 (void) ccmp_hdr2pn(pn, skb->data + hdrlen);
564 if (memcmp(pn, key->u.ccmp.rx_pn[rx->u.rx.queue], CCMP_PN_LEN) <= 0) {
565 #ifdef CONFIG_MAC80211_DEBUG
566 u8 *ppn = key->u.ccmp.rx_pn[rx->u.rx.queue];
567 printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from "
568 MAC_FMT " (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN "
569 "%02x%02x%02x%02x%02x%02x)\n", rx->dev->name,
570 MAC_ARG(rx->sta->addr),
571 pn[0], pn[1], pn[2], pn[3], pn[4], pn[5],
572 ppn[0], ppn[1], ppn[2], ppn[3], ppn[4], ppn[5]);
573 #endif /* CONFIG_MAC80211_DEBUG */
574 key->u.ccmp.replays++;
578 if (!(rx->u.rx.status->flag & RX_FLAG_DECRYPTED)) {
579 /* hardware didn't decrypt/verify MIC */
580 u8 *scratch, *b_0, *aad;
582 scratch = key->u.ccmp.rx_crypto_buf;
583 b_0 = scratch + 3 * AES_BLOCK_LEN;
584 aad = scratch + 4 * AES_BLOCK_LEN;
586 ccmp_special_blocks(skb, pn, b_0, aad, 1);
588 if (ieee80211_aes_ccm_decrypt(
589 key->u.ccmp.tfm, scratch, b_0, aad,
590 skb->data + hdrlen + CCMP_HDR_LEN, data_len,
591 skb->data + skb->len - CCMP_MIC_LEN,
592 skb->data + hdrlen + CCMP_HDR_LEN)) {
593 printk(KERN_DEBUG "%s: CCMP decrypt failed for RX "
594 "frame from " MAC_FMT "\n", rx->dev->name,
595 MAC_ARG(rx->sta->addr));
600 memcpy(key->u.ccmp.rx_pn[rx->u.rx.queue], pn, CCMP_PN_LEN);
602 /* Remove CCMP header and MIC */
603 skb_trim(skb, skb->len - CCMP_MIC_LEN);
604 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
605 skb_pull(skb, CCMP_HDR_LEN);
607 return TXRX_CONTINUE;