2 * Copyright 2002-2004, Instant802 Networks, Inc.
3 * Copyright 2008, Jouni Malinen <j@w1.fi>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
10 #include <linux/netdevice.h>
11 #include <linux/types.h>
12 #include <linux/slab.h>
13 #include <linux/skbuff.h>
14 #include <linux/compiler.h>
15 #include <linux/ieee80211.h>
16 #include <asm/unaligned.h>
17 #include <net/mac80211.h>
19 #include "ieee80211_i.h"
27 ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
29 u8 *data, *key, *mic, key_offset;
32 struct ieee80211_hdr *hdr;
33 struct sk_buff *skb = tx->skb;
38 hdr = (struct ieee80211_hdr *)skb->data;
39 if (!tx->key || tx->key->conf.alg != ALG_TKIP || skb->len < 24 ||
40 !ieee80211_is_data_present(hdr->frame_control))
43 hdrlen = ieee80211_hdrlen(hdr->frame_control);
44 if (skb->len < hdrlen)
47 data = skb->data + hdrlen;
48 data_len = skb->len - hdrlen;
50 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
51 !(tx->flags & IEEE80211_TX_FRAGMENTED) &&
52 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) &&
54 /* hwaccel - with no need for preallocated room for MMIC */
58 tail = MICHAEL_MIC_LEN;
59 if (!(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
62 if (WARN_ON(skb_tailroom(skb) < tail ||
63 skb_headroom(skb) < TKIP_IV_LEN))
67 authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
71 key_offset = authenticator ?
72 NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY :
73 NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY;
74 key = &tx->key->conf.key[key_offset];
75 mic = skb_put(skb, MICHAEL_MIC_LEN);
76 michael_mic(key, hdr, data, data_len, mic);
83 ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
85 u8 *data, *key = NULL, key_offset;
88 struct ieee80211_hdr *hdr;
89 u8 mic[MICHAEL_MIC_LEN];
90 struct sk_buff *skb = rx->skb;
91 int authenticator = 1, wpa_test = 0;
93 /* No way to verify the MIC if the hardware stripped it */
94 if (rx->status->flag & RX_FLAG_MMIC_STRIPPED)
97 hdr = (struct ieee80211_hdr *)skb->data;
98 if (!rx->key || rx->key->conf.alg != ALG_TKIP ||
99 !ieee80211_has_protected(hdr->frame_control) ||
100 !ieee80211_is_data_present(hdr->frame_control))
103 hdrlen = ieee80211_hdrlen(hdr->frame_control);
104 if (skb->len < hdrlen + MICHAEL_MIC_LEN)
105 return RX_DROP_UNUSABLE;
107 data = skb->data + hdrlen;
108 data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;
111 authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
115 key_offset = authenticator ?
116 NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY :
117 NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY;
118 key = &rx->key->conf.key[key_offset];
119 michael_mic(key, hdr, data, data_len, mic);
120 if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) {
121 if (!(rx->flags & IEEE80211_RX_RA_MATCH))
122 return RX_DROP_UNUSABLE;
124 mac80211_ev_michael_mic_failure(rx->sdata, rx->key->conf.keyidx,
125 (void *) skb->data, NULL,
127 return RX_DROP_UNUSABLE;
130 /* remove Michael MIC from payload */
131 skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
133 /* update IV in key information to be able to detect replays */
134 rx->key->u.tkip.rx[rx->queue].iv32 = rx->tkip_iv32;
135 rx->key->u.tkip.rx[rx->queue].iv16 = rx->tkip_iv16;
141 static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
143 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
144 struct ieee80211_key *key = tx->key;
145 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
150 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
151 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
152 /* hwaccel - with no need for preallocated room for IV/ICV */
153 info->control.hw_key = &tx->key->conf;
157 hdrlen = ieee80211_hdrlen(hdr->frame_control);
158 len = skb->len - hdrlen;
160 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
165 if (WARN_ON(skb_tailroom(skb) < tail ||
166 skb_headroom(skb) < TKIP_IV_LEN))
169 pos = skb_push(skb, TKIP_IV_LEN);
170 memmove(pos, pos + TKIP_IV_LEN, hdrlen);
173 /* Increase IV for the frame */
174 key->u.tkip.tx.iv16++;
175 if (key->u.tkip.tx.iv16 == 0)
176 key->u.tkip.tx.iv32++;
178 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
179 /* hwaccel - with preallocated room for IV */
180 ieee80211_tkip_add_iv(pos, key, key->u.tkip.tx.iv16);
182 info->control.hw_key = &tx->key->conf;
186 /* Add room for ICV */
187 skb_put(skb, TKIP_ICV_LEN);
189 hdr = (struct ieee80211_hdr *) skb->data;
190 ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
191 key, pos, len, hdr->addr2);
197 ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
199 struct sk_buff *skb = tx->skb;
201 ieee80211_tx_set_protected(tx);
204 if (tkip_encrypt_skb(tx, skb) < 0)
206 } while ((skb = skb->next));
213 ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
215 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
216 int hdrlen, res, hwaccel = 0, wpa_test = 0;
217 struct ieee80211_key *key = rx->key;
218 struct sk_buff *skb = rx->skb;
220 hdrlen = ieee80211_hdrlen(hdr->frame_control);
222 if (!ieee80211_is_data(hdr->frame_control))
225 if (!rx->sta || skb->len - hdrlen < 12)
226 return RX_DROP_UNUSABLE;
228 if (rx->status->flag & RX_FLAG_DECRYPTED) {
229 if (rx->status->flag & RX_FLAG_IV_STRIPPED) {
231 * Hardware took care of all processing, including
232 * replay protection, and stripped the ICV/IV so
233 * we cannot do any checks here.
238 /* let TKIP code verify IV, but skip decryption */
242 res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
243 key, skb->data + hdrlen,
244 skb->len - hdrlen, rx->sta->sta.addr,
245 hdr->addr1, hwaccel, rx->queue,
248 if (res != TKIP_DECRYPT_OK || wpa_test)
249 return RX_DROP_UNUSABLE;
252 skb_trim(skb, skb->len - TKIP_ICV_LEN);
255 memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
256 skb_pull(skb, TKIP_IV_LEN);
262 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *scratch,
266 int a4_included, mgmt;
271 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
273 b_0 = scratch + 3 * AES_BLOCK_LEN;
274 aad = scratch + 4 * AES_BLOCK_LEN;
277 * Mask FC: zero subtype b4 b5 b6 (if not mgmt)
278 * Retry, PwrMgt, MoreData; set Protected
280 mgmt = ieee80211_is_mgmt(hdr->frame_control);
281 mask_fc = hdr->frame_control;
282 mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
283 IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
285 mask_fc &= ~cpu_to_le16(0x0070);
286 mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
288 hdrlen = ieee80211_hdrlen(hdr->frame_control);
290 a4_included = ieee80211_has_a4(hdr->frame_control);
292 if (ieee80211_is_data_qos(hdr->frame_control))
293 qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
297 data_len = skb->len - hdrlen - CCMP_HDR_LEN;
299 data_len -= CCMP_MIC_LEN;
301 /* First block, b_0 */
302 b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
303 /* Nonce: Nonce Flags | A2 | PN
304 * Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)
306 b_0[1] = qos_tid | (mgmt << 4);
307 memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
308 memcpy(&b_0[8], pn, CCMP_PN_LEN);
310 put_unaligned_be16(data_len, &b_0[14]);
312 /* AAD (extra authenticate-only data) / masked 802.11 header
313 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
314 put_unaligned_be16(len_a, &aad[0]);
315 put_unaligned(mask_fc, (__le16 *)&aad[2]);
316 memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
318 /* Mask Seq#, leave Frag# */
319 aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
323 memcpy(&aad[24], hdr->addr4, ETH_ALEN);
327 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
333 static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
338 hdr[3] = 0x20 | (key_id << 6);
346 static inline void ccmp_hdr2pn(u8 *pn, u8 *hdr)
357 static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
359 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
360 struct ieee80211_key *key = tx->key;
361 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
362 int hdrlen, len, tail;
367 skip_hw = (tx->key->conf.flags & IEEE80211_KEY_FLAG_SW_MGMT) &&
368 ieee80211_is_mgmt(hdr->frame_control);
370 if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
371 !(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
373 /* hwaccel - with no need for preallocated room for CCMP
374 * header or MIC fields */
375 info->control.hw_key = &tx->key->conf;
379 hdrlen = ieee80211_hdrlen(hdr->frame_control);
380 len = skb->len - hdrlen;
382 if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
387 if (WARN_ON(skb_tailroom(skb) < tail ||
388 skb_headroom(skb) < CCMP_HDR_LEN))
391 pos = skb_push(skb, CCMP_HDR_LEN);
392 memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
393 hdr = (struct ieee80211_hdr *) pos;
397 pn = key->u.ccmp.tx_pn;
399 for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
405 ccmp_pn2hdr(pos, pn, key->conf.keyidx);
407 if ((key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) && !skip_hw) {
408 /* hwaccel - with preallocated room for CCMP header */
409 info->control.hw_key = &tx->key->conf;
414 ccmp_special_blocks(skb, pn, key->u.ccmp.tx_crypto_buf, 0);
415 ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, key->u.ccmp.tx_crypto_buf, pos, len,
416 pos, skb_put(skb, CCMP_MIC_LEN));
423 ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx)
425 struct sk_buff *skb = tx->skb;
427 ieee80211_tx_set_protected(tx);
430 if (ccmp_encrypt_skb(tx, skb) < 0)
432 } while ((skb = skb->next));
439 ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx)
441 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
443 struct ieee80211_key *key = rx->key;
444 struct sk_buff *skb = rx->skb;
448 hdrlen = ieee80211_hdrlen(hdr->frame_control);
450 if (!ieee80211_is_data(hdr->frame_control) &&
451 !ieee80211_is_robust_mgmt_frame(hdr))
454 data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
455 if (!rx->sta || data_len < 0)
456 return RX_DROP_UNUSABLE;
458 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
459 (rx->status->flag & RX_FLAG_IV_STRIPPED))
462 ccmp_hdr2pn(pn, skb->data + hdrlen);
464 if (memcmp(pn, key->u.ccmp.rx_pn[rx->queue], CCMP_PN_LEN) <= 0) {
465 key->u.ccmp.replays++;
466 return RX_DROP_UNUSABLE;
469 if (!(rx->status->flag & RX_FLAG_DECRYPTED)) {
470 /* hardware didn't decrypt/verify MIC */
471 ccmp_special_blocks(skb, pn, key->u.ccmp.rx_crypto_buf, 1);
473 if (ieee80211_aes_ccm_decrypt(
474 key->u.ccmp.tfm, key->u.ccmp.rx_crypto_buf,
475 skb->data + hdrlen + CCMP_HDR_LEN, data_len,
476 skb->data + skb->len - CCMP_MIC_LEN,
477 skb->data + hdrlen + CCMP_HDR_LEN))
478 return RX_DROP_UNUSABLE;
481 memcpy(key->u.ccmp.rx_pn[rx->queue], pn, CCMP_PN_LEN);
483 /* Remove CCMP header and MIC */
484 skb_trim(skb, skb->len - CCMP_MIC_LEN);
485 memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
486 skb_pull(skb, CCMP_HDR_LEN);
492 static void bip_aad(struct sk_buff *skb, u8 *aad)
494 /* BIP AAD: FC(masked) || A1 || A2 || A3 */
496 /* FC type/subtype */
497 aad[0] = skb->data[0];
498 /* Mask FC Retry, PwrMgt, MoreData flags to zero */
499 aad[1] = skb->data[1] & ~(BIT(4) | BIT(5) | BIT(6));
501 memcpy(aad + 2, skb->data + 4, 3 * ETH_ALEN);
505 static inline void bip_ipn_swap(u8 *d, const u8 *s)
517 ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
519 struct sk_buff *skb = tx->skb;
520 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
521 struct ieee80211_key *key = tx->key;
522 struct ieee80211_mmie *mmie;
526 if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
528 info->control.hw_key = &tx->key->conf;
532 if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
535 mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie));
536 mmie->element_id = WLAN_EID_MMIE;
537 mmie->length = sizeof(*mmie) - 2;
538 mmie->key_id = cpu_to_le16(key->conf.keyidx);
541 pn = key->u.aes_cmac.tx_pn;
543 for (i = sizeof(key->u.aes_cmac.tx_pn) - 1; i >= 0; i--) {
548 bip_ipn_swap(mmie->sequence_number, pn);
553 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
555 ieee80211_aes_cmac(key->u.aes_cmac.tfm, key->u.aes_cmac.tx_crypto_buf,
556 aad, skb->data + 24, skb->len - 24, mmie->mic);
563 ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
565 struct sk_buff *skb = rx->skb;
566 struct ieee80211_key *key = rx->key;
567 struct ieee80211_mmie *mmie;
568 u8 aad[20], mic[8], ipn[6];
569 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
571 if (!ieee80211_is_mgmt(hdr->frame_control))
574 if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
575 (rx->status->flag & RX_FLAG_IV_STRIPPED))
578 if (skb->len < 24 + sizeof(*mmie))
579 return RX_DROP_UNUSABLE;
581 mmie = (struct ieee80211_mmie *)
582 (skb->data + skb->len - sizeof(*mmie));
583 if (mmie->element_id != WLAN_EID_MMIE ||
584 mmie->length != sizeof(*mmie) - 2)
585 return RX_DROP_UNUSABLE; /* Invalid MMIE */
587 bip_ipn_swap(ipn, mmie->sequence_number);
589 if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
590 key->u.aes_cmac.replays++;
591 return RX_DROP_UNUSABLE;
594 if (!(rx->status->flag & RX_FLAG_DECRYPTED)) {
595 /* hardware didn't decrypt/verify MIC */
597 ieee80211_aes_cmac(key->u.aes_cmac.tfm,
598 key->u.aes_cmac.rx_crypto_buf, aad,
599 skb->data + 24, skb->len - 24, mic);
600 if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
601 key->u.aes_cmac.icverrors++;
602 return RX_DROP_UNUSABLE;
606 memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
609 skb_trim(skb, skb->len - sizeof(*mmie));