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3017b80bf0
android_kernel_xiaomi_sdm845/net/mac80211/wpa.c
Johannes Berg 3017b80bf0 [MAC80211]: fix software decryption 
When doing key selection for software decryption, mac80211 gets
a few things wrong: it always uses pairwise keys if configured,
even if the frame is addressed to a multicast address. Also, it
doesn't allow using a key index of zero if a pairwise key has
also been found.

This patch changes the key selection code to be (more) in line
with the 802.11 specification. I have confirmed that with this,
multicast frames are correctly decrypted and I've tested with
WEP as well.

While at it, I've cleaned up the semantics of the hardware flags
IEEE80211_HW_WEP_INCLUDE_IV and IEEE80211_HW_DEVICE_HIDES_WEP
and clarified them in the mac80211.h header; it is also now
allowed to set the IEEE80211_HW_DEVICE_HIDES_WEP option even if
it only applies to frames that have been decrypted by the hw,
unencrypted frames must be dropped but encrypted frames that
the hardware couldn't handle can be passed up unmodified.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2007-10-10 16:48:44 -07:00

662 lines
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/*
* Copyright 2002-2004, Instant802 Networks, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/compiler.h>
#include <net/iw_handler.h>
#include <net/mac80211.h>
#include "ieee80211_common.h"
#include "ieee80211_i.h"
#include "michael.h"
#include "tkip.h"
#include "aes_ccm.h"
#include "wpa.h"
static int ieee80211_get_hdr_info(const struct sk_buff *skb, u8 **sa, u8 **da,
u8 *qos_tid, u8 **data, size_t *data_len)
{
struct ieee80211_hdr *hdr;
size_t hdrlen;
u16 fc;
int a4_included;
u8 *pos;
hdr = (struct ieee80211_hdr *) skb->data;
fc = le16_to_cpu(hdr->frame_control);
hdrlen = 24;
if ((fc & (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) ==
(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
hdrlen += ETH_ALEN;
*sa = hdr->addr4;
*da = hdr->addr3;
} else if (fc & IEEE80211_FCTL_FROMDS) {
*sa = hdr->addr3;
*da = hdr->addr1;
} else if (fc & IEEE80211_FCTL_TODS) {
*sa = hdr->addr2;
*da = hdr->addr3;
} else {
*sa = hdr->addr2;
*da = hdr->addr1;
}
if (fc & 0x80)
hdrlen += 2;
*data = skb->data + hdrlen;
*data_len = skb->len - hdrlen;
a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
if ((fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
fc & IEEE80211_STYPE_QOS_DATA) {
pos = (u8 *) &hdr->addr4;
if (a4_included)
pos += 6;
*qos_tid = pos[0] & 0x0f;
*qos_tid |= 0x80; /* qos_included flag */
} else
*qos_tid = 0;
return skb->len < hdrlen ? -1 : 0;
}
ieee80211_txrx_result
ieee80211_tx_h_michael_mic_add(struct ieee80211_txrx_data *tx)
{
u8 *data, *sa, *da, *key, *mic, qos_tid;
size_t data_len;
u16 fc;
struct sk_buff *skb = tx->skb;
int authenticator;
int wpa_test = 0;
fc = tx->fc;
if (!tx->key || tx->key->alg != ALG_TKIP || skb->len < 24 ||
!WLAN_FC_DATA_PRESENT(fc))
return TXRX_CONTINUE;
if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len))
return TXRX_DROP;
if (!tx->key->force_sw_encrypt &&
!tx->fragmented &&
!(tx->local->hw.flags & IEEE80211_HW_TKIP_INCLUDE_MMIC) &&
!wpa_test) {
/* hwaccel - with no need for preallocated room for Michael MIC
*/
return TXRX_CONTINUE;
}
if (skb_tailroom(skb) < MICHAEL_MIC_LEN) {
I802_DEBUG_INC(tx->local->tx_expand_skb_head);
if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN,
MICHAEL_MIC_LEN + TKIP_ICV_LEN,
GFP_ATOMIC))) {
printk(KERN_DEBUG "%s: failed to allocate more memory "
"for Michael MIC\n", tx->dev->name);
return TXRX_DROP;
}
}
#if 0
authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
#else
authenticator = 1;
#endif
key = &tx->key->key[authenticator ? ALG_TKIP_TEMP_AUTH_TX_MIC_KEY :
ALG_TKIP_TEMP_AUTH_RX_MIC_KEY];
mic = skb_put(skb, MICHAEL_MIC_LEN);
michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
return TXRX_CONTINUE;
}
ieee80211_txrx_result
ieee80211_rx_h_michael_mic_verify(struct ieee80211_txrx_data *rx)
{
u8 *data, *sa, *da, *key = NULL, qos_tid;
size_t data_len;
u16 fc;
u8 mic[MICHAEL_MIC_LEN];
struct sk_buff *skb = rx->skb;
int authenticator = 1, wpa_test = 0;
fc = rx->fc;
/*
* No way to verify the MIC if the hardware stripped it
*/
if (rx->local->hw.flags & IEEE80211_HW_DEVICE_STRIPS_MIC)
return TXRX_CONTINUE;
if (!rx->key || rx->key->alg != ALG_TKIP ||
!(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc))
return TXRX_CONTINUE;
if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
!rx->key->force_sw_encrypt) {
if (rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) {
if (skb->len < MICHAEL_MIC_LEN)
return TXRX_DROP;
}
/* Need to verify Michael MIC sometimes in software even when
* hwaccel is used. Atheros ar5212: fragmented frames and QoS
* frames. */
if (!rx->fragmented && !wpa_test)
goto remove_mic;
}
if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)
|| data_len < MICHAEL_MIC_LEN)
return TXRX_DROP;
data_len -= MICHAEL_MIC_LEN;
#if 0
authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
#else
authenticator = 1;
#endif
key = &rx->key->key[authenticator ? ALG_TKIP_TEMP_AUTH_RX_MIC_KEY :
ALG_TKIP_TEMP_AUTH_TX_MIC_KEY];
michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0 || wpa_test) {
if (!rx->u.rx.ra_match)
return TXRX_DROP;
printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from "
MAC_FMT "\n", rx->dev->name, MAC_ARG(sa));
do {
struct ieee80211_hdr *hdr;
union iwreq_data wrqu;
char *buf = kmalloc(128, GFP_ATOMIC);
if (!buf)
break;
/* TODO: needed parameters: count, key type, TSC */
hdr = (struct ieee80211_hdr *) skb->data;
sprintf(buf, "MLME-MICHAELMICFAILURE.indication("
"keyid=%d %scast addr=" MAC_FMT ")",
rx->key->keyidx,
hdr->addr1[0] & 0x01 ? "broad" : "uni",
MAC_ARG(hdr->addr2));
memset(&wrqu, 0, sizeof(wrqu));
wrqu.data.length = strlen(buf);
wireless_send_event(rx->dev, IWEVCUSTOM, &wrqu, buf);
kfree(buf);
} while (0);
if (!rx->local->apdev)
return TXRX_DROP;
ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
ieee80211_msg_michael_mic_failure);
return TXRX_QUEUED;
}
remove_mic:
/* remove Michael MIC from payload */
skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
return TXRX_CONTINUE;
}
static int tkip_encrypt_skb(struct ieee80211_txrx_data *tx,
struct sk_buff *skb, int test)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ieee80211_key *key = tx->key;
int hdrlen, len, tailneed;
u16 fc;
u8 *pos;
fc = le16_to_cpu(hdr->frame_control);
hdrlen = ieee80211_get_hdrlen(fc);
len = skb->len - hdrlen;
tailneed = !tx->key->force_sw_encrypt ? 0 : TKIP_ICV_LEN;
if ((skb_headroom(skb) < TKIP_IV_LEN ||
skb_tailroom(skb) < tailneed)) {
I802_DEBUG_INC(tx->local->tx_expand_skb_head);
if (unlikely(pskb_expand_head(skb, TKIP_IV_LEN, tailneed,
GFP_ATOMIC)))
return -1;
}
pos = skb_push(skb, TKIP_IV_LEN);
memmove(pos, pos + TKIP_IV_LEN, hdrlen);
pos += hdrlen;
/* Increase IV for the frame */
key->u.tkip.iv16++;
if (key->u.tkip.iv16 == 0)
key->u.tkip.iv32++;
if (!tx->key->force_sw_encrypt) {
u32 flags = tx->local->hw.flags;
hdr = (struct ieee80211_hdr *)skb->data;
/* hwaccel - with preallocated room for IV */
ieee80211_tkip_add_iv(pos, key,
(u8) (key->u.tkip.iv16 >> 8),
(u8) (((key->u.tkip.iv16 >> 8) | 0x20) &
0x7f),
(u8) key->u.tkip.iv16);
if (flags & IEEE80211_HW_TKIP_REQ_PHASE2_KEY)
ieee80211_tkip_gen_rc4key(key, hdr->addr2,
tx->u.tx.control->tkip_key);
else if (flags & IEEE80211_HW_TKIP_REQ_PHASE1_KEY) {
if (key->u.tkip.iv16 == 0 ||
!key->u.tkip.tx_initialized) {
ieee80211_tkip_gen_phase1key(key, hdr->addr2,
(u16 *)tx->u.tx.control->tkip_key);
key->u.tkip.tx_initialized = 1;
tx->u.tx.control->flags |=
IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY;
} else
tx->u.tx.control->flags &=
~IEEE80211_TXCTL_TKIP_NEW_PHASE1_KEY;
}
tx->u.tx.control->key_idx = tx->key->hw_key_idx;
return 0;
}
/* Add room for ICV */
skb_put(skb, TKIP_ICV_LEN);
hdr = (struct ieee80211_hdr *) skb->data;
ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
key, pos, len, hdr->addr2);
return 0;
}
ieee80211_txrx_result
ieee80211_tx_h_tkip_encrypt(struct ieee80211_txrx_data *tx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
u16 fc;
struct ieee80211_key *key = tx->key;
struct sk_buff *skb = tx->skb;
int wpa_test = 0, test = 0;
fc = le16_to_cpu(hdr->frame_control);
if (!key || key->alg != ALG_TKIP || !WLAN_FC_DATA_PRESENT(fc))
return TXRX_CONTINUE;
tx->u.tx.control->icv_len = TKIP_ICV_LEN;
tx->u.tx.control->iv_len = TKIP_IV_LEN;
ieee80211_tx_set_iswep(tx);
if (!tx->key->force_sw_encrypt &&
!(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) &&
!wpa_test) {
/* hwaccel - with no need for preallocated room for IV/ICV */
tx->u.tx.control->key_idx = tx->key->hw_key_idx;
return TXRX_CONTINUE;
}
if (tkip_encrypt_skb(tx, skb, test) < 0)
return TXRX_DROP;
if (tx->u.tx.extra_frag) {
int i;
for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
if (tkip_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
< 0)
return TXRX_DROP;
}
}
return TXRX_CONTINUE;
}
ieee80211_txrx_result
ieee80211_rx_h_tkip_decrypt(struct ieee80211_txrx_data *rx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
u16 fc;
int hdrlen, res, hwaccel = 0, wpa_test = 0;
struct ieee80211_key *key = rx->key;
struct sk_buff *skb = rx->skb;
fc = le16_to_cpu(hdr->frame_control);
hdrlen = ieee80211_get_hdrlen(fc);
if (!rx->key || rx->key->alg != ALG_TKIP ||
!(rx->fc & IEEE80211_FCTL_PROTECTED) ||
(rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
return TXRX_CONTINUE;
if (!rx->sta || skb->len - hdrlen < 12)
return TXRX_DROP;
if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
!rx->key->force_sw_encrypt) {
if (!(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) {
/* Hardware takes care of all processing, including
* replay protection, so no need to continue here. */
return TXRX_CONTINUE;
}
/* let TKIP code verify IV, but skip decryption */
hwaccel = 1;
}
res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
key, skb->data + hdrlen,
skb->len - hdrlen, rx->sta->addr,
hwaccel, rx->u.rx.queue);
if (res != TKIP_DECRYPT_OK || wpa_test) {
printk(KERN_DEBUG "%s: TKIP decrypt failed for RX frame from "
MAC_FMT " (res=%d)\n",
rx->dev->name, MAC_ARG(rx->sta->addr), res);
return TXRX_DROP;
}
/* Trim ICV */
skb_trim(skb, skb->len - TKIP_ICV_LEN);
/* Remove IV */
memmove(skb->data + TKIP_IV_LEN, skb->data, hdrlen);
skb_pull(skb, TKIP_IV_LEN);
return TXRX_CONTINUE;
}
static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
int encrypted)
{
u16 fc;
int a4_included, qos_included;
u8 qos_tid, *fc_pos, *data, *sa, *da;
int len_a;
size_t data_len;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
fc_pos = (u8 *) &hdr->frame_control;
fc = fc_pos[0] ^ (fc_pos[1] << 8);
a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len);
data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0);
if (qos_tid & 0x80) {
qos_included = 1;
qos_tid &= 0x0f;
} else
qos_included = 0;
/* First block, b_0 */
b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
/* Nonce: QoS Priority | A2 | PN */
b_0[1] = qos_tid;
memcpy(&b_0[2], hdr->addr2, 6);
memcpy(&b_0[8], pn, CCMP_PN_LEN);
/* l(m) */
b_0[14] = (data_len >> 8) & 0xff;
b_0[15] = data_len & 0xff;
/* AAD (extra authenticate-only data) / masked 802.11 header
* FC | A1 | A2 | A3 | SC | [A4] | [QC] */
len_a = a4_included ? 28 : 22;
if (qos_included)
len_a += 2;
aad[0] = 0; /* (len_a >> 8) & 0xff; */
aad[1] = len_a & 0xff;
/* Mask FC: zero subtype b4 b5 b6 */
aad[2] = fc_pos[0] & ~(BIT(4) | BIT(5) | BIT(6));
/* Retry, PwrMgt, MoreData; set Protected */
aad[3] = (fc_pos[1] & ~(BIT(3) | BIT(4) | BIT(5))) | BIT(6);
memcpy(&aad[4], &hdr->addr1, 18);
/* Mask Seq#, leave Frag# */
aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
aad[23] = 0;
if (a4_included) {
memcpy(&aad[24], hdr->addr4, 6);
aad[30] = 0;
aad[31] = 0;
} else
memset(&aad[24], 0, 8);
if (qos_included) {
u8 *dpos = &aad[a4_included ? 30 : 24];
/* Mask QoS Control field */
dpos[0] = qos_tid;
dpos[1] = 0;
}
}
static inline void ccmp_pn2hdr(u8 *hdr, u8 *pn, int key_id)
{
hdr[0] = pn[5];
hdr[1] = pn[4];
hdr[2] = 0;
hdr[3] = 0x20 | (key_id << 6);
hdr[4] = pn[3];
hdr[5] = pn[2];
hdr[6] = pn[1];
hdr[7] = pn[0];
}
static inline int ccmp_hdr2pn(u8 *pn, u8 *hdr)
{
pn[0] = hdr[7];
pn[1] = hdr[6];
pn[2] = hdr[5];
pn[3] = hdr[4];
pn[4] = hdr[1];
pn[5] = hdr[0];
return (hdr[3] >> 6) & 0x03;
}
static int ccmp_encrypt_skb(struct ieee80211_txrx_data *tx,
struct sk_buff *skb, int test)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ieee80211_key *key = tx->key;
int hdrlen, len, tailneed;
u16 fc;
u8 *pos, *pn, *b_0, *aad, *scratch;
int i;
scratch = key->u.ccmp.tx_crypto_buf;
b_0 = scratch + 3 * AES_BLOCK_LEN;
aad = scratch + 4 * AES_BLOCK_LEN;
fc = le16_to_cpu(hdr->frame_control);
hdrlen = ieee80211_get_hdrlen(fc);
len = skb->len - hdrlen;
tailneed = !key->force_sw_encrypt ? 0 : CCMP_MIC_LEN;
if ((skb_headroom(skb) < CCMP_HDR_LEN ||
skb_tailroom(skb) < tailneed)) {
I802_DEBUG_INC(tx->local->tx_expand_skb_head);
if (unlikely(pskb_expand_head(skb, CCMP_HDR_LEN, tailneed,
GFP_ATOMIC)))
return -1;
}
pos = skb_push(skb, CCMP_HDR_LEN);
memmove(pos, pos + CCMP_HDR_LEN, hdrlen);
hdr = (struct ieee80211_hdr *) pos;
pos += hdrlen;
/* PN = PN + 1 */
pn = key->u.ccmp.tx_pn;
for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
pn[i]++;
if (pn[i])
break;
}
ccmp_pn2hdr(pos, pn, key->keyidx);
if (!key->force_sw_encrypt) {
/* hwaccel - with preallocated room for CCMP header */
tx->u.tx.control->key_idx = key->hw_key_idx;
return 0;
}
pos += CCMP_HDR_LEN;
ccmp_special_blocks(skb, pn, b_0, aad, 0);
ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, scratch, b_0, aad, pos, len,
pos, skb_put(skb, CCMP_MIC_LEN));
return 0;
}
ieee80211_txrx_result
ieee80211_tx_h_ccmp_encrypt(struct ieee80211_txrx_data *tx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
struct ieee80211_key *key = tx->key;
u16 fc;
struct sk_buff *skb = tx->skb;
int test = 0;
fc = le16_to_cpu(hdr->frame_control);
if (!key || key->alg != ALG_CCMP || !WLAN_FC_DATA_PRESENT(fc))
return TXRX_CONTINUE;
tx->u.tx.control->icv_len = CCMP_MIC_LEN;
tx->u.tx.control->iv_len = CCMP_HDR_LEN;
ieee80211_tx_set_iswep(tx);
if (!tx->key->force_sw_encrypt &&
!(tx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) {
/* hwaccel - with no need for preallocated room for CCMP "
* header or MIC fields */
tx->u.tx.control->key_idx = tx->key->hw_key_idx;
return TXRX_CONTINUE;
}
if (ccmp_encrypt_skb(tx, skb, test) < 0)
return TXRX_DROP;
if (tx->u.tx.extra_frag) {
int i;
for (i = 0; i < tx->u.tx.num_extra_frag; i++) {
if (ccmp_encrypt_skb(tx, tx->u.tx.extra_frag[i], test)
< 0)
return TXRX_DROP;
}
}
return TXRX_CONTINUE;
}
ieee80211_txrx_result
ieee80211_rx_h_ccmp_decrypt(struct ieee80211_txrx_data *rx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
u16 fc;
int hdrlen;
struct ieee80211_key *key = rx->key;
struct sk_buff *skb = rx->skb;
u8 pn[CCMP_PN_LEN];
int data_len;
fc = le16_to_cpu(hdr->frame_control);
hdrlen = ieee80211_get_hdrlen(fc);
if (!key || key->alg != ALG_CCMP ||
!(rx->fc & IEEE80211_FCTL_PROTECTED) ||
(rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
return TXRX_CONTINUE;
data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
if (!rx->sta || data_len < 0)
return TXRX_DROP;
if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
!key->force_sw_encrypt &&
!(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV))
return TXRX_CONTINUE;
(void) ccmp_hdr2pn(pn, skb->data + hdrlen);
if (memcmp(pn, key->u.ccmp.rx_pn[rx->u.rx.queue], CCMP_PN_LEN) <= 0) {
#ifdef CONFIG_MAC80211_DEBUG
u8 *ppn = key->u.ccmp.rx_pn[rx->u.rx.queue];
printk(KERN_DEBUG "%s: CCMP replay detected for RX frame from "
MAC_FMT " (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN "
"%02x%02x%02x%02x%02x%02x)\n", rx->dev->name,
MAC_ARG(rx->sta->addr),
pn[0], pn[1], pn[2], pn[3], pn[4], pn[5],
ppn[0], ppn[1], ppn[2], ppn[3], ppn[4], ppn[5]);
#endif /* CONFIG_MAC80211_DEBUG */
key->u.ccmp.replays++;
return TXRX_DROP;
}
if ((rx->u.rx.status->flag & RX_FLAG_DECRYPTED) &&
!key->force_sw_encrypt) {
/* hwaccel has already decrypted frame and verified MIC */
} else {
u8 *scratch, *b_0, *aad;
scratch = key->u.ccmp.rx_crypto_buf;
b_0 = scratch + 3 * AES_BLOCK_LEN;
aad = scratch + 4 * AES_BLOCK_LEN;
ccmp_special_blocks(skb, pn, b_0, aad, 1);
if (ieee80211_aes_ccm_decrypt(
key->u.ccmp.tfm, scratch, b_0, aad,
skb->data + hdrlen + CCMP_HDR_LEN, data_len,
skb->data + skb->len - CCMP_MIC_LEN,
skb->data + hdrlen + CCMP_HDR_LEN)) {
printk(KERN_DEBUG "%s: CCMP decrypt failed for RX "
"frame from " MAC_FMT "\n", rx->dev->name,
MAC_ARG(rx->sta->addr));
return TXRX_DROP;
}
}
memcpy(key->u.ccmp.rx_pn[rx->u.rx.queue], pn, CCMP_PN_LEN);
/* Remove CCMP header and MIC */
skb_trim(skb, skb->len - CCMP_MIC_LEN);
memmove(skb->data + CCMP_HDR_LEN, skb->data, hdrlen);
skb_pull(skb, CCMP_HDR_LEN);
return TXRX_CONTINUE;
}
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