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wpa.c
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wpa.c
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/*
* Copyright 2002-2004, Instant802 Networks, Inc.
* Copyright 2008, Jouni Malinen <j@w1.fi>
* Copyright (C) 2016 Intel Deutschland GmbH
*
* 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/skbuff.h>
#include <linux/compiler.h>
#include <linux/ieee80211.h>
#include <linux/gfp.h>
#include <asm/unaligned.h>
#include <net/mac80211.h>
#include <crypto/aes.h>
#include "ieee80211_i.h"
#include "michael.h"
#include "tkip.h"
#include "aes_ccm.h"
#include "aes_cmac.h"
#include "aes_gmac.h"
#include "aes_gcm.h"
#include "wpa.h"
ieee80211_tx_result
ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
{
u8 *data, *key, *mic;
size_t data_len;
unsigned int hdrlen;
struct ieee80211_hdr *hdr;
struct sk_buff *skb = tx->skb;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
int tail;
hdr = (struct ieee80211_hdr *)skb->data;
if (!tx->key || tx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
skb->len < 24 || !ieee80211_is_data_present(hdr->frame_control))
return TX_CONTINUE;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
if (skb->len < hdrlen)
return TX_DROP;
data = skb->data + hdrlen;
data_len = skb->len - hdrlen;
if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE)) {
/* Need to use software crypto for the test */
info->control.hw_key = NULL;
}
if (info->control.hw_key &&
(info->flags & IEEE80211_TX_CTL_DONTFRAG ||
ieee80211_hw_check(&tx->local->hw, SUPPORTS_TX_FRAG)) &&
!(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) {
/* hwaccel - with no need for SW-generated MMIC */
return TX_CONTINUE;
}
tail = MICHAEL_MIC_LEN;
if (!info->control.hw_key)
tail += IEEE80211_TKIP_ICV_LEN;
if (WARN(skb_tailroom(skb) < tail ||
skb_headroom(skb) < IEEE80211_TKIP_IV_LEN,
"mmic: not enough head/tail (%d/%d,%d/%d)\n",
skb_headroom(skb), IEEE80211_TKIP_IV_LEN,
skb_tailroom(skb), tail))
return TX_DROP;
key = &tx->key->conf.key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY];
mic = skb_put(skb, MICHAEL_MIC_LEN);
michael_mic(key, hdr, data, data_len, mic);
if (unlikely(info->flags & IEEE80211_TX_INTFL_TKIP_MIC_FAILURE))
mic[0]++;
return TX_CONTINUE;
}
ieee80211_rx_result
ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
{
u8 *data, *key = NULL;
size_t data_len;
unsigned int hdrlen;
u8 mic[MICHAEL_MIC_LEN];
struct sk_buff *skb = rx->skb;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
/*
* it makes no sense to check for MIC errors on anything other
* than data frames.
*/
if (!ieee80211_is_data_present(hdr->frame_control))
return RX_CONTINUE;
/*
* No way to verify the MIC if the hardware stripped it or
* the IV with the key index. In this case we have solely rely
* on the driver to set RX_FLAG_MMIC_ERROR in the event of a
* MIC failure report.
*/
if (status->flag & (RX_FLAG_MMIC_STRIPPED | RX_FLAG_IV_STRIPPED)) {
if (status->flag & RX_FLAG_MMIC_ERROR)
goto mic_fail_no_key;
if (!(status->flag & RX_FLAG_IV_STRIPPED) && rx->key &&
rx->key->conf.cipher == WLAN_CIPHER_SUITE_TKIP)
goto update_iv;
return RX_CONTINUE;
}
/*
* Some hardware seems to generate Michael MIC failure reports; even
* though, the frame was not encrypted with TKIP and therefore has no
* MIC. Ignore the flag them to avoid triggering countermeasures.
*/
if (!rx->key || rx->key->conf.cipher != WLAN_CIPHER_SUITE_TKIP ||
!(status->flag & RX_FLAG_DECRYPTED))
return RX_CONTINUE;
if (rx->sdata->vif.type == NL80211_IFTYPE_AP && rx->key->conf.keyidx) {
/*
* APs with pairwise keys should never receive Michael MIC
* errors for non-zero keyidx because these are reserved for
* group keys and only the AP is sending real multicast
* frames in the BSS.
*/
return RX_DROP_UNUSABLE;
}
if (status->flag & RX_FLAG_MMIC_ERROR)
goto mic_fail;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
if (skb->len < hdrlen + MICHAEL_MIC_LEN)
return RX_DROP_UNUSABLE;
if (skb_linearize(rx->skb))
return RX_DROP_UNUSABLE;
hdr = (void *)skb->data;
data = skb->data + hdrlen;
data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;
key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY];
michael_mic(key, hdr, data, data_len, mic);
if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0)
goto mic_fail;
/* remove Michael MIC from payload */
skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
update_iv:
/* update IV in key information to be able to detect replays */
rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip_iv32;
rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip_iv16;
return RX_CONTINUE;
mic_fail:
rx->key->u.tkip.mic_failures++;
mic_fail_no_key:
/*
* In some cases the key can be unset - e.g. a multicast packet, in
* a driver that supports HW encryption. Send up the key idx only if
* the key is set.
*/
cfg80211_michael_mic_failure(rx->sdata->dev, hdr->addr2,
is_multicast_ether_addr(hdr->addr1) ?
NL80211_KEYTYPE_GROUP :
NL80211_KEYTYPE_PAIRWISE,
rx->key ? rx->key->conf.keyidx : -1,
NULL, GFP_ATOMIC);
return RX_DROP_UNUSABLE;
}
static int tkip_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ieee80211_key *key = tx->key;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
unsigned int hdrlen;
int len, tail;
u64 pn;
u8 *pos;
if (info->control.hw_key &&
!(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
!(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
/* hwaccel - with no need for software-generated IV */
return 0;
}
hdrlen = ieee80211_hdrlen(hdr->frame_control);
len = skb->len - hdrlen;
if (info->control.hw_key)
tail = 0;
else
tail = IEEE80211_TKIP_ICV_LEN;
if (WARN_ON(skb_tailroom(skb) < tail ||
skb_headroom(skb) < IEEE80211_TKIP_IV_LEN))
return -1;
pos = skb_push(skb, IEEE80211_TKIP_IV_LEN);
memmove(pos, pos + IEEE80211_TKIP_IV_LEN, hdrlen);
pos += hdrlen;
/* the HW only needs room for the IV, but not the actual IV */
if (info->control.hw_key &&
(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
return 0;
/* Increase IV for the frame */
pn = atomic64_inc_return(&key->conf.tx_pn);
pos = ieee80211_tkip_add_iv(pos, &key->conf, pn);
/* hwaccel - with software IV */
if (info->control.hw_key)
return 0;
/* Add room for ICV */
skb_put(skb, IEEE80211_TKIP_ICV_LEN);
return ieee80211_tkip_encrypt_data(tx->local->wep_tx_tfm,
key, skb, pos, len);
}
ieee80211_tx_result
ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
{
struct sk_buff *skb;
ieee80211_tx_set_protected(tx);
skb_queue_walk(&tx->skbs, skb) {
if (tkip_encrypt_skb(tx, skb) < 0)
return TX_DROP;
}
return TX_CONTINUE;
}
ieee80211_rx_result
ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
int hdrlen, res, hwaccel = 0;
struct ieee80211_key *key = rx->key;
struct sk_buff *skb = rx->skb;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
hdrlen = ieee80211_hdrlen(hdr->frame_control);
if (!ieee80211_is_data(hdr->frame_control))
return RX_CONTINUE;
if (!rx->sta || skb->len - hdrlen < 12)
return RX_DROP_UNUSABLE;
/* it may be possible to optimize this a bit more */
if (skb_linearize(rx->skb))
return RX_DROP_UNUSABLE;
hdr = (void *)skb->data;
/*
* Let TKIP code verify IV, but skip decryption.
* In the case where hardware checks the IV as well,
* we don't even get here, see ieee80211_rx_h_decrypt()
*/
if (status->flag & RX_FLAG_DECRYPTED)
hwaccel = 1;
res = ieee80211_tkip_decrypt_data(rx->local->wep_rx_tfm,
key, skb->data + hdrlen,
skb->len - hdrlen, rx->sta->sta.addr,
hdr->addr1, hwaccel, rx->security_idx,
&rx->tkip_iv32,
&rx->tkip_iv16);
if (res != TKIP_DECRYPT_OK)
return RX_DROP_UNUSABLE;
/* Trim ICV */
if (!(status->flag & RX_FLAG_ICV_STRIPPED))
skb_trim(skb, skb->len - IEEE80211_TKIP_ICV_LEN);
/* Remove IV */
memmove(skb->data + IEEE80211_TKIP_IV_LEN, skb->data, hdrlen);
skb_pull(skb, IEEE80211_TKIP_IV_LEN);
return RX_CONTINUE;
}
static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad)
{
__le16 mask_fc;
int a4_included, mgmt;
u8 qos_tid;
u16 len_a;
unsigned int hdrlen;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
/*
* Mask FC: zero subtype b4 b5 b6 (if not mgmt)
* Retry, PwrMgt, MoreData; set Protected
*/
mgmt = ieee80211_is_mgmt(hdr->frame_control);
mask_fc = hdr->frame_control;
mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
if (!mgmt)
mask_fc &= ~cpu_to_le16(0x0070);
mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
hdrlen = ieee80211_hdrlen(hdr->frame_control);
len_a = hdrlen - 2;
a4_included = ieee80211_has_a4(hdr->frame_control);
if (ieee80211_is_data_qos(hdr->frame_control))
qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
else
qos_tid = 0;
/* In CCM, the initial vectors (IV) used for CTR mode encryption and CBC
* mode authentication are not allowed to collide, yet both are derived
* from this vector b_0. We only set L := 1 here to indicate that the
* data size can be represented in (L+1) bytes. The CCM layer will take
* care of storing the data length in the top (L+1) bytes and setting
* and clearing the other bits as is required to derive the two IVs.
*/
b_0[0] = 0x1;
/* Nonce: Nonce Flags | A2 | PN
* Nonce Flags: Priority (b0..b3) | Management (b4) | Reserved (b5..b7)
*/
b_0[1] = qos_tid | (mgmt << 4);
memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
memcpy(&b_0[8], pn, IEEE80211_CCMP_PN_LEN);
/* AAD (extra authenticate-only data) / masked 802.11 header
* FC | A1 | A2 | A3 | SC | [A4] | [QC] */
put_unaligned_be16(len_a, &aad[0]);
put_unaligned(mask_fc, (__le16 *)&aad[2]);
memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
/* Mask Seq#, leave Frag# */
aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
aad[23] = 0;
if (a4_included) {
memcpy(&aad[24], hdr->addr4, ETH_ALEN);
aad[30] = qos_tid;
aad[31] = 0;
} else {
memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
aad[24] = qos_tid;
}
}
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 void 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];
}
static int ccmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb,
unsigned int mic_len)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ieee80211_key *key = tx->key;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
int hdrlen, len, tail;
u8 *pos;
u8 pn[6];
u64 pn64;
u8 aad[CCM_AAD_LEN];
u8 b_0[AES_BLOCK_SIZE];
if (info->control.hw_key &&
!(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
!(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
!((info->control.hw_key->flags &
IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
ieee80211_is_mgmt(hdr->frame_control))) {
/*
* hwaccel has no need for preallocated room for CCMP
* header or MIC fields
*/
return 0;
}
hdrlen = ieee80211_hdrlen(hdr->frame_control);
len = skb->len - hdrlen;
if (info->control.hw_key)
tail = 0;
else
tail = mic_len;
if (WARN_ON(skb_tailroom(skb) < tail ||
skb_headroom(skb) < IEEE80211_CCMP_HDR_LEN))
return -1;
pos = skb_push(skb, IEEE80211_CCMP_HDR_LEN);
memmove(pos, pos + IEEE80211_CCMP_HDR_LEN, hdrlen);
/* the HW only needs room for the IV, but not the actual IV */
if (info->control.hw_key &&
(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
return 0;
hdr = (struct ieee80211_hdr *) pos;
pos += hdrlen;
pn64 = atomic64_inc_return(&key->conf.tx_pn);
pn[5] = pn64;
pn[4] = pn64 >> 8;
pn[3] = pn64 >> 16;
pn[2] = pn64 >> 24;
pn[1] = pn64 >> 32;
pn[0] = pn64 >> 40;
ccmp_pn2hdr(pos, pn, key->conf.keyidx);
/* hwaccel - with software CCMP header */
if (info->control.hw_key)
return 0;
pos += IEEE80211_CCMP_HDR_LEN;
ccmp_special_blocks(skb, pn, b_0, aad);
return ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,
skb_put(skb, mic_len), mic_len);
}
ieee80211_tx_result
ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx,
unsigned int mic_len)
{
struct sk_buff *skb;
ieee80211_tx_set_protected(tx);
skb_queue_walk(&tx->skbs, skb) {
if (ccmp_encrypt_skb(tx, skb, mic_len) < 0)
return TX_DROP;
}
return TX_CONTINUE;
}
ieee80211_rx_result
ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
unsigned int mic_len)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
int hdrlen;
struct ieee80211_key *key = rx->key;
struct sk_buff *skb = rx->skb;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
u8 pn[IEEE80211_CCMP_PN_LEN];
int data_len;
int queue;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
if (!ieee80211_is_data(hdr->frame_control) &&
!ieee80211_is_robust_mgmt_frame(skb))
return RX_CONTINUE;
if (status->flag & RX_FLAG_DECRYPTED) {
if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_CCMP_HDR_LEN))
return RX_DROP_UNUSABLE;
if (status->flag & RX_FLAG_MIC_STRIPPED)
mic_len = 0;
} else {
if (skb_linearize(rx->skb))
return RX_DROP_UNUSABLE;
}
data_len = skb->len - hdrlen - IEEE80211_CCMP_HDR_LEN - mic_len;
if (!rx->sta || data_len < 0)
return RX_DROP_UNUSABLE;
if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
int res;
ccmp_hdr2pn(pn, skb->data + hdrlen);
queue = rx->security_idx;
res = memcmp(pn, key->u.ccmp.rx_pn[queue],
IEEE80211_CCMP_PN_LEN);
if (res < 0 ||
(!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
key->u.ccmp.replays++;
return RX_DROP_UNUSABLE;
}
if (!(status->flag & RX_FLAG_DECRYPTED)) {
u8 aad[2 * AES_BLOCK_SIZE];
u8 b_0[AES_BLOCK_SIZE];
/* hardware didn't decrypt/verify MIC */
ccmp_special_blocks(skb, pn, b_0, aad);
if (ieee80211_aes_ccm_decrypt(
key->u.ccmp.tfm, b_0, aad,
skb->data + hdrlen + IEEE80211_CCMP_HDR_LEN,
data_len,
skb->data + skb->len - mic_len, mic_len))
return RX_DROP_UNUSABLE;
}
memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN);
}
/* Remove CCMP header and MIC */
if (pskb_trim(skb, skb->len - mic_len))
return RX_DROP_UNUSABLE;
memmove(skb->data + IEEE80211_CCMP_HDR_LEN, skb->data, hdrlen);
skb_pull(skb, IEEE80211_CCMP_HDR_LEN);
return RX_CONTINUE;
}
static void gcmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *j_0, u8 *aad)
{
__le16 mask_fc;
u8 qos_tid;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
memcpy(j_0, hdr->addr2, ETH_ALEN);
memcpy(&j_0[ETH_ALEN], pn, IEEE80211_GCMP_PN_LEN);
j_0[13] = 0;
j_0[14] = 0;
j_0[AES_BLOCK_SIZE - 1] = 0x01;
/* AAD (extra authenticate-only data) / masked 802.11 header
* FC | A1 | A2 | A3 | SC | [A4] | [QC]
*/
put_unaligned_be16(ieee80211_hdrlen(hdr->frame_control) - 2, &aad[0]);
/* Mask FC: zero subtype b4 b5 b6 (if not mgmt)
* Retry, PwrMgt, MoreData; set Protected
*/
mask_fc = hdr->frame_control;
mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY |
IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
if (!ieee80211_is_mgmt(hdr->frame_control))
mask_fc &= ~cpu_to_le16(0x0070);
mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
put_unaligned(mask_fc, (__le16 *)&aad[2]);
memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
/* Mask Seq#, leave Frag# */
aad[22] = *((u8 *)&hdr->seq_ctrl) & 0x0f;
aad[23] = 0;
if (ieee80211_is_data_qos(hdr->frame_control))
qos_tid = *ieee80211_get_qos_ctl(hdr) &
IEEE80211_QOS_CTL_TID_MASK;
else
qos_tid = 0;
if (ieee80211_has_a4(hdr->frame_control)) {
memcpy(&aad[24], hdr->addr4, ETH_ALEN);
aad[30] = qos_tid;
aad[31] = 0;
} else {
memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
aad[24] = qos_tid;
}
}
static inline void gcmp_pn2hdr(u8 *hdr, const 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 void gcmp_hdr2pn(u8 *pn, const 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];
}
static int gcmp_encrypt_skb(struct ieee80211_tx_data *tx, struct sk_buff *skb)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
struct ieee80211_key *key = tx->key;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
int hdrlen, len, tail;
u8 *pos;
u8 pn[6];
u64 pn64;
u8 aad[GCM_AAD_LEN];
u8 j_0[AES_BLOCK_SIZE];
if (info->control.hw_key &&
!(info->control.hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
!(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
!((info->control.hw_key->flags &
IEEE80211_KEY_FLAG_GENERATE_IV_MGMT) &&
ieee80211_is_mgmt(hdr->frame_control))) {
/* hwaccel has no need for preallocated room for GCMP
* header or MIC fields
*/
return 0;
}
hdrlen = ieee80211_hdrlen(hdr->frame_control);
len = skb->len - hdrlen;
if (info->control.hw_key)
tail = 0;
else
tail = IEEE80211_GCMP_MIC_LEN;
if (WARN_ON(skb_tailroom(skb) < tail ||
skb_headroom(skb) < IEEE80211_GCMP_HDR_LEN))
return -1;
pos = skb_push(skb, IEEE80211_GCMP_HDR_LEN);
memmove(pos, pos + IEEE80211_GCMP_HDR_LEN, hdrlen);
skb_set_network_header(skb, skb_network_offset(skb) +
IEEE80211_GCMP_HDR_LEN);
/* the HW only needs room for the IV, but not the actual IV */
if (info->control.hw_key &&
(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE))
return 0;
hdr = (struct ieee80211_hdr *)pos;
pos += hdrlen;
pn64 = atomic64_inc_return(&key->conf.tx_pn);
pn[5] = pn64;
pn[4] = pn64 >> 8;
pn[3] = pn64 >> 16;
pn[2] = pn64 >> 24;
pn[1] = pn64 >> 32;
pn[0] = pn64 >> 40;
gcmp_pn2hdr(pos, pn, key->conf.keyidx);
/* hwaccel - with software GCMP header */
if (info->control.hw_key)
return 0;
pos += IEEE80211_GCMP_HDR_LEN;
gcmp_special_blocks(skb, pn, j_0, aad);
return ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len,
skb_put(skb, IEEE80211_GCMP_MIC_LEN));
}
ieee80211_tx_result
ieee80211_crypto_gcmp_encrypt(struct ieee80211_tx_data *tx)
{
struct sk_buff *skb;
ieee80211_tx_set_protected(tx);
skb_queue_walk(&tx->skbs, skb) {
if (gcmp_encrypt_skb(tx, skb) < 0)
return TX_DROP;
}
return TX_CONTINUE;
}
ieee80211_rx_result
ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
int hdrlen;
struct ieee80211_key *key = rx->key;
struct sk_buff *skb = rx->skb;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
u8 pn[IEEE80211_GCMP_PN_LEN];
int data_len, queue, mic_len = IEEE80211_GCMP_MIC_LEN;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
if (!ieee80211_is_data(hdr->frame_control) &&
!ieee80211_is_robust_mgmt_frame(skb))
return RX_CONTINUE;
if (status->flag & RX_FLAG_DECRYPTED) {
if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN))
return RX_DROP_UNUSABLE;
if (status->flag & RX_FLAG_MIC_STRIPPED)
mic_len = 0;
} else {
if (skb_linearize(rx->skb))
return RX_DROP_UNUSABLE;
}
data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN - mic_len;
if (!rx->sta || data_len < 0)
return RX_DROP_UNUSABLE;
if (!(status->flag & RX_FLAG_PN_VALIDATED)) {
int res;
gcmp_hdr2pn(pn, skb->data + hdrlen);
queue = rx->security_idx;
res = memcmp(pn, key->u.gcmp.rx_pn[queue],
IEEE80211_GCMP_PN_LEN);
if (res < 0 ||
(!res && !(status->flag & RX_FLAG_ALLOW_SAME_PN))) {
key->u.gcmp.replays++;
return RX_DROP_UNUSABLE;
}
if (!(status->flag & RX_FLAG_DECRYPTED)) {
u8 aad[2 * AES_BLOCK_SIZE];
u8 j_0[AES_BLOCK_SIZE];
/* hardware didn't decrypt/verify MIC */
gcmp_special_blocks(skb, pn, j_0, aad);
if (ieee80211_aes_gcm_decrypt(
key->u.gcmp.tfm, j_0, aad,
skb->data + hdrlen + IEEE80211_GCMP_HDR_LEN,
data_len,
skb->data + skb->len -
IEEE80211_GCMP_MIC_LEN))
return RX_DROP_UNUSABLE;
}
memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN);
}
/* Remove GCMP header and MIC */
if (pskb_trim(skb, skb->len - mic_len))
return RX_DROP_UNUSABLE;
memmove(skb->data + IEEE80211_GCMP_HDR_LEN, skb->data, hdrlen);
skb_pull(skb, IEEE80211_GCMP_HDR_LEN);
return RX_CONTINUE;
}
static ieee80211_tx_result
ieee80211_crypto_cs_encrypt(struct ieee80211_tx_data *tx,
struct sk_buff *skb)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
struct ieee80211_key *key = tx->key;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
int hdrlen;
u8 *pos, iv_len = key->conf.iv_len;
if (info->control.hw_key &&
!(info->control.hw_key->flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE)) {
/* hwaccel has no need for preallocated head room */
return TX_CONTINUE;
}
if (unlikely(skb_headroom(skb) < iv_len &&
pskb_expand_head(skb, iv_len, 0, GFP_ATOMIC)))
return TX_DROP;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
pos = skb_push(skb, iv_len);
memmove(pos, pos + iv_len, hdrlen);
return TX_CONTINUE;
}
static inline int ieee80211_crypto_cs_pn_compare(u8 *pn1, u8 *pn2, int len)
{
int i;
/* pn is little endian */
for (i = len - 1; i >= 0; i--) {
if (pn1[i] < pn2[i])
return -1;
else if (pn1[i] > pn2[i])
return 1;
}
return 0;
}
static ieee80211_rx_result
ieee80211_crypto_cs_decrypt(struct ieee80211_rx_data *rx)
{
struct ieee80211_key *key = rx->key;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
const struct ieee80211_cipher_scheme *cs = NULL;
int hdrlen = ieee80211_hdrlen(hdr->frame_control);
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
int data_len;
u8 *rx_pn;
u8 *skb_pn;
u8 qos_tid;
if (!rx->sta || !rx->sta->cipher_scheme ||
!(status->flag & RX_FLAG_DECRYPTED))
return RX_DROP_UNUSABLE;
if (!ieee80211_is_data(hdr->frame_control))
return RX_CONTINUE;
cs = rx->sta->cipher_scheme;
data_len = rx->skb->len - hdrlen - cs->hdr_len;
if (data_len < 0)
return RX_DROP_UNUSABLE;
if (ieee80211_is_data_qos(hdr->frame_control))
qos_tid = *ieee80211_get_qos_ctl(hdr) &
IEEE80211_QOS_CTL_TID_MASK;
else
qos_tid = 0;
if (skb_linearize(rx->skb))
return RX_DROP_UNUSABLE;
hdr = (struct ieee80211_hdr *)rx->skb->data;
rx_pn = key->u.gen.rx_pn[qos_tid];
skb_pn = rx->skb->data + hdrlen + cs->pn_off;
if (ieee80211_crypto_cs_pn_compare(skb_pn, rx_pn, cs->pn_len) <= 0)
return RX_DROP_UNUSABLE;
memcpy(rx_pn, skb_pn, cs->pn_len);
/* remove security header and MIC */
if (pskb_trim(rx->skb, rx->skb->len - cs->mic_len))
return RX_DROP_UNUSABLE;
memmove(rx->skb->data + cs->hdr_len, rx->skb->data, hdrlen);
skb_pull(rx->skb, cs->hdr_len);
return RX_CONTINUE;
}
static void bip_aad(struct sk_buff *skb, u8 *aad)
{
__le16 mask_fc;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
/* BIP AAD: FC(masked) || A1 || A2 || A3 */
/* FC type/subtype */
/* Mask FC Retry, PwrMgt, MoreData flags to zero */
mask_fc = hdr->frame_control;
mask_fc &= ~cpu_to_le16(IEEE80211_FCTL_RETRY | IEEE80211_FCTL_PM |
IEEE80211_FCTL_MOREDATA);
put_unaligned(mask_fc, (__le16 *) &aad[0]);
/* A1 || A2 || A3 */
memcpy(aad + 2, &hdr->addr1, 3 * ETH_ALEN);
}
static inline void bip_ipn_set64(u8 *d, u64 pn)
{
*d++ = pn;
*d++ = pn >> 8;
*d++ = pn >> 16;
*d++ = pn >> 24;
*d++ = pn >> 32;
*d = pn >> 40;
}
static inline void bip_ipn_swap(u8 *d, const u8 *s)
{
*d++ = s[5];
*d++ = s[4];
*d++ = s[3];
*d++ = s[2];
*d++ = s[1];
*d = s[0];
}
ieee80211_tx_result
ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
{
struct sk_buff *skb;
struct ieee80211_tx_info *info;
struct ieee80211_key *key = tx->key;
struct ieee80211_mmie *mmie;
u8 aad[20];
u64 pn64;
if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
return TX_DROP;
skb = skb_peek(&tx->skbs);
info = IEEE80211_SKB_CB(skb);
if (info->control.hw_key)
return TX_CONTINUE;
if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
return TX_DROP;
mmie = (struct ieee80211_mmie *) skb_put(skb, sizeof(*mmie));
mmie->element_id = WLAN_EID_MMIE;
mmie->length = sizeof(*mmie) - 2;
mmie->key_id = cpu_to_le16(key->conf.keyidx);
/* PN = PN + 1 */
pn64 = atomic64_inc_return(&key->conf.tx_pn);
bip_ipn_set64(mmie->sequence_number, pn64);
bip_aad(skb, aad);
/*
* MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
*/
ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
skb->data + 24, skb->len - 24, mmie->mic);
return TX_CONTINUE;
}
ieee80211_tx_result
ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx)
{
struct sk_buff *skb;
struct ieee80211_tx_info *info;
struct ieee80211_key *key = tx->key;
struct ieee80211_mmie_16 *mmie;
u8 aad[20];
u64 pn64;
if (WARN_ON(skb_queue_len(&tx->skbs) != 1))
return TX_DROP;
skb = skb_peek(&tx->skbs);
info = IEEE80211_SKB_CB(skb);
if (info->control.hw_key)
return TX_CONTINUE;
if (WARN_ON(skb_tailroom(skb) < sizeof(*mmie)))
return TX_DROP;
mmie = (struct ieee80211_mmie_16 *)skb_put(skb, sizeof(*mmie));
mmie->element_id = WLAN_EID_MMIE;
mmie->length = sizeof(*mmie) - 2;
mmie->key_id = cpu_to_le16(key->conf.keyidx);
/* PN = PN + 1 */