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alistair23-linux/net/mac80211/wpa.c
Johannes Berg db388a567f mac80211: move TX PN to public part of key struct 
For drivers supporting TSO or similar features, but that still have
PN assignment in software, there's a need to have some memory to
store the current PN value. As mac80211 already stores this and it's
somewhat complicated to add a per-driver area to the key struct (due
to the dynamic sizing thereof) it makes sense to just move the TX PN
to the keyconf, i.e. the public part of the key struct.

As TKIP is more complicated and we won't able to offload it in this
way right now (fast-xmit is skipped for TKIP unless the HW does it
all, and our hardware needs MMIC calculation in software) I've not
moved that for now - it's possible but requires exposing a lot of
the internal TKIP state.

As an bonus side effect, we can remove a lot of code by assuming the
keyseq struct has a certain layout - with BUILD_BUG_ON to verify it.

This might also improve performance, since now TX and RX no longer
share a cacheline.

Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-06-02 11:16:35 +02:00

1239 lines
31 KiB
C
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/*
* Copyright 2002-2004, Instant802 Networks, Inc.
* Copyright 2008, Jouni Malinen <j@w1.fi>
*
* 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 ||
tx->local->ops->set_frag_threshold) &&
!(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.
*/
mac80211_ev_michael_mic_failure(rx->sdata,
rx->key ? rx->key->conf.keyidx : -1,
(void *) skb->data, 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;
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 */
spin_lock(&key->u.tkip.txlock);
key->u.tkip.tx.iv16++;
if (key->u.tkip.tx.iv16 == 0)
key->u.tkip.tx.iv32++;
pos = ieee80211_tkip_add_iv(pos, key);
spin_unlock(&key->u.tkip.txlock);
/* 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 */
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[2 * AES_BLOCK_SIZE];
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);
ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, b_0, aad, pos, len,
skb_put(skb, mic_len), mic_len);
return 0;
}
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;
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_DECRYPTED) {
if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_CCMP_HDR_LEN))
return RX_DROP_UNUSABLE;
} else {
if (skb_linearize(rx->skb))
return RX_DROP_UNUSABLE;
}
ccmp_hdr2pn(pn, skb->data + hdrlen);
queue = rx->security_idx;
if (memcmp(pn, key->u.ccmp.rx_pn[queue], IEEE80211_CCMP_PN_LEN) <= 0) {
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[2 * AES_BLOCK_SIZE];
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);
ieee80211_aes_gcm_encrypt(key->u.gcmp.tfm, j_0, aad, pos, len,
skb_put(skb, IEEE80211_GCMP_MIC_LEN));
return 0;
}
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;
int queue;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
if (!ieee80211_is_data(hdr->frame_control) &&
!ieee80211_is_robust_mgmt_frame(skb))
return RX_CONTINUE;
data_len = skb->len - hdrlen - IEEE80211_GCMP_HDR_LEN -
IEEE80211_GCMP_MIC_LEN;
if (!rx->sta || data_len < 0)
return RX_DROP_UNUSABLE;
if (status->flag & RX_FLAG_DECRYPTED) {
if (!pskb_may_pull(rx->skb, hdrlen + IEEE80211_GCMP_HDR_LEN))
return RX_DROP_UNUSABLE;
} else {
if (skb_linearize(rx->skb))
return RX_DROP_UNUSABLE;
}
gcmp_hdr2pn(pn, skb->data + hdrlen);
queue = rx->security_idx;
if (memcmp(pn, key->u.gcmp.rx_pn[queue], IEEE80211_GCMP_PN_LEN) <= 0) {
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 - IEEE80211_GCMP_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 */
pn64 = atomic64_inc_return(&key->conf.tx_pn);
bip_ipn_set64(mmie->sequence_number, pn64);
bip_aad(skb, aad);
/* MIC = AES-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128)
*/
ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
skb->data + 24, skb->len - 24, mmie->mic);
return TX_CONTINUE;
}
ieee80211_rx_result
ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
{
struct sk_buff *skb = rx->skb;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
struct ieee80211_key *key = rx->key;
struct ieee80211_mmie *mmie;
u8 aad[20], mic[8], ipn[6];
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
if (!ieee80211_is_mgmt(hdr->frame_control))
return RX_CONTINUE;
/* management frames are already linear */
if (skb->len < 24 + sizeof(*mmie))
return RX_DROP_UNUSABLE;
mmie = (struct ieee80211_mmie *)
(skb->data + skb->len - sizeof(*mmie));
if (mmie->element_id != WLAN_EID_MMIE ||
mmie->length != sizeof(*mmie) - 2)
return RX_DROP_UNUSABLE; /* Invalid MMIE */
bip_ipn_swap(ipn, mmie->sequence_number);
if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
key->u.aes_cmac.replays++;
return RX_DROP_UNUSABLE;
}
if (!(status->flag & RX_FLAG_DECRYPTED)) {
/* hardware didn't decrypt/verify MIC */
bip_aad(skb, aad);
ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
skb->data + 24, skb->len - 24, mic);
if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
key->u.aes_cmac.icverrors++;
return RX_DROP_UNUSABLE;
}
}
memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
/* Remove MMIE */
skb_trim(skb, skb->len - sizeof(*mmie));
return RX_CONTINUE;
}
ieee80211_rx_result
ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx)
{
struct sk_buff *skb = rx->skb;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
struct ieee80211_key *key = rx->key;
struct ieee80211_mmie_16 *mmie;
u8 aad[20], mic[16], ipn[6];
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
if (!ieee80211_is_mgmt(hdr->frame_control))
return RX_CONTINUE;
/* management frames are already linear */
if (skb->len < 24 + sizeof(*mmie))
return RX_DROP_UNUSABLE;
mmie = (struct ieee80211_mmie_16 *)
(skb->data + skb->len - sizeof(*mmie));
if (mmie->element_id != WLAN_EID_MMIE ||
mmie->length != sizeof(*mmie) - 2)
return RX_DROP_UNUSABLE; /* Invalid MMIE */
bip_ipn_swap(ipn, mmie->sequence_number);
if (memcmp(ipn, key->u.aes_cmac.rx_pn, 6) <= 0) {
key->u.aes_cmac.replays++;
return RX_DROP_UNUSABLE;
}
if (!(status->flag & RX_FLAG_DECRYPTED)) {
/* hardware didn't decrypt/verify MIC */
bip_aad(skb, aad);
ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
skb->data + 24, skb->len - 24, mic);
if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
key->u.aes_cmac.icverrors++;
return RX_DROP_UNUSABLE;
}
}
memcpy(key->u.aes_cmac.rx_pn, ipn, 6);
/* Remove MMIE */
skb_trim(skb, skb->len - sizeof(*mmie));
return RX_CONTINUE;
}
ieee80211_tx_result
ieee80211_crypto_aes_gmac_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;
struct ieee80211_hdr *hdr;
u8 aad[20];
u64 pn64;
u8 nonce[12];
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 */
pn64 = atomic64_inc_return(&key->conf.tx_pn);
bip_ipn_set64(mmie->sequence_number, pn64);
bip_aad(skb, aad);
hdr = (struct ieee80211_hdr *)skb->data;
memcpy(nonce, hdr->addr2, ETH_ALEN);
bip_ipn_swap(nonce + ETH_ALEN, mmie->sequence_number);
/* MIC = AES-GMAC(IGTK, AAD || Management Frame Body || MMIE, 128) */
if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
skb->data + 24, skb->len - 24, mmie->mic) < 0)
return TX_DROP;
return TX_CONTINUE;
}
ieee80211_rx_result
ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data *rx)
{
struct sk_buff *skb = rx->skb;
struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
struct ieee80211_key *key = rx->key;
struct ieee80211_mmie_16 *mmie;
u8 aad[20], mic[16], ipn[6], nonce[12];
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
if (!ieee80211_is_mgmt(hdr->frame_control))
return RX_CONTINUE;
/* management frames are already linear */
if (skb->len < 24 + sizeof(*mmie))
return RX_DROP_UNUSABLE;
mmie = (struct ieee80211_mmie_16 *)
(skb->data + skb->len - sizeof(*mmie));
if (mmie->element_id != WLAN_EID_MMIE ||
mmie->length != sizeof(*mmie) - 2)
return RX_DROP_UNUSABLE; /* Invalid MMIE */
bip_ipn_swap(ipn, mmie->sequence_number);
if (memcmp(ipn, key->u.aes_gmac.rx_pn, 6) <= 0) {
key->u.aes_gmac.replays++;
return RX_DROP_UNUSABLE;
}
if (!(status->flag & RX_FLAG_DECRYPTED)) {
/* hardware didn't decrypt/verify MIC */
bip_aad(skb, aad);
memcpy(nonce, hdr->addr2, ETH_ALEN);
memcpy(nonce + ETH_ALEN, ipn, 6);
if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
skb->data + 24, skb->len - 24,
mic) < 0 ||
memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
key->u.aes_gmac.icverrors++;
return RX_DROP_UNUSABLE;
}
}
memcpy(key->u.aes_gmac.rx_pn, ipn, 6);
/* Remove MMIE */
skb_trim(skb, skb->len - sizeof(*mmie));
return RX_CONTINUE;
}
ieee80211_tx_result
ieee80211_crypto_hw_encrypt(struct ieee80211_tx_data *tx)
{
struct sk_buff *skb;
struct ieee80211_tx_info *info = NULL;
ieee80211_tx_result res;
skb_queue_walk(&tx->skbs, skb) {
info = IEEE80211_SKB_CB(skb);
/* handle hw-only algorithm */
if (!info->control.hw_key)
return TX_DROP;
if (tx->key->flags & KEY_FLAG_CIPHER_SCHEME) {
res = ieee80211_crypto_cs_encrypt(tx, skb);
if (res != TX_CONTINUE)
return res;
}
}
ieee80211_tx_set_protected(tx);
return TX_CONTINUE;
}
ieee80211_rx_result
ieee80211_crypto_hw_decrypt(struct ieee80211_rx_data *rx)
{
if (rx->sta && rx->sta->cipher_scheme)
return ieee80211_crypto_cs_decrypt(rx);
return RX_DROP_UNUSABLE;
}
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