blob: b414d5d92f38f97aea43c37dc1d395d302fb0c5b [file] [log] [blame]
/*
* 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/mac80211.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;
__le16 fc;
hdr = (struct ieee80211_hdr *)skb->data;
fc = hdr->frame_control;
hdrlen = ieee80211_hdrlen(fc);
*sa = ieee80211_get_SA(hdr);
*da = ieee80211_get_DA(hdr);
*data = skb->data + hdrlen;
*data_len = skb->len - hdrlen;
if (ieee80211_is_data_qos(fc))
*qos_tid = (*ieee80211_get_qos_ctl(hdr) & 0x0f) | 0x80;
else
*qos_tid = 0;
return skb->len < hdrlen ? -1 : 0;
}
ieee80211_tx_result
ieee80211_tx_h_michael_mic_add(struct ieee80211_tx_data *tx)
{
u8 *data, *sa, *da, *key, *mic, qos_tid, key_offset;
size_t data_len;
u16 fc;
struct sk_buff *skb = tx->skb;
int authenticator;
int wpa_test = 0;
int tail;
fc = tx->fc;
if (!tx->key || tx->key->conf.alg != ALG_TKIP || skb->len < 24 ||
!WLAN_FC_DATA_PRESENT(fc))
return TX_CONTINUE;
if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len))
return TX_DROP;
if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
!(tx->flags & IEEE80211_TX_FRAGMENTED) &&
!(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC) &&
!wpa_test) {
/* hwaccel - with no need for preallocated room for Michael MIC
*/
return TX_CONTINUE;
}
tail = MICHAEL_MIC_LEN;
if (!(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
tail += TKIP_ICV_LEN;
if (WARN_ON(skb_tailroom(skb) < tail ||
skb_headroom(skb) < TKIP_IV_LEN))
return TX_DROP;
#if 0
authenticator = fc & IEEE80211_FCTL_FROMDS; /* FIX */
#else
authenticator = 1;
#endif
/* At this point we know we're using ALG_TKIP. To get the MIC key
* we now will rely on the offset from the ieee80211_key_conf::key */
key_offset = authenticator ?
NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY :
NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY;
key = &tx->key->conf.key[key_offset];
mic = skb_put(skb, MICHAEL_MIC_LEN);
michael_mic(key, da, sa, qos_tid & 0x0f, data, data_len, mic);
return TX_CONTINUE;
}
ieee80211_rx_result
ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
{
u8 *data, *sa, *da, *key = NULL, qos_tid, key_offset;
size_t data_len;
u16 fc;
u8 mic[MICHAEL_MIC_LEN];
struct sk_buff *skb = rx->skb;
int authenticator = 1, wpa_test = 0;
DECLARE_MAC_BUF(mac);
fc = rx->fc;
/*
* No way to verify the MIC if the hardware stripped it
*/
if (rx->status->flag & RX_FLAG_MMIC_STRIPPED)
return RX_CONTINUE;
if (!rx->key || rx->key->conf.alg != ALG_TKIP ||
!(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc))
return RX_CONTINUE;
if (ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len)
|| data_len < MICHAEL_MIC_LEN)
return RX_DROP_UNUSABLE;
data_len -= MICHAEL_MIC_LEN;
#if 0
authenticator = fc & IEEE80211_FCTL_TODS; /* FIX */
#else
authenticator = 1;
#endif
/* At this point we know we're using ALG_TKIP. To get the MIC key
* we now will rely on the offset from the ieee80211_key_conf::key */
key_offset = authenticator ?
NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY :
NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY;
key = &rx->key->conf.key[key_offset];
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->flags & IEEE80211_RX_RA_MATCH))
return RX_DROP_UNUSABLE;
mac80211_ev_michael_mic_failure(rx->dev, rx->key->conf.keyidx,
(void *) skb->data);
return RX_DROP_UNUSABLE;
}
/* remove Michael MIC from payload */
skb_trim(skb, skb->len - MICHAEL_MIC_LEN);
/* update IV in key information to be able to detect replays */
rx->key->u.tkip.rx[rx->queue].iv32 = rx->tkip_iv32;
rx->key->u.tkip.rx[rx->queue].iv16 = rx->tkip_iv16;
return RX_CONTINUE;
}
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;
info->control.icv_len = TKIP_ICV_LEN;
info->control.iv_len = TKIP_IV_LEN;
if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
!(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
/* hwaccel - with no need for preallocated room for IV/ICV */
info->control.hw_key = &tx->key->conf;
return 0;
}
hdrlen = ieee80211_hdrlen(hdr->frame_control);
len = skb->len - hdrlen;
if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
tail = 0;
else
tail = TKIP_ICV_LEN;
if (WARN_ON(skb_tailroom(skb) < tail ||
skb_headroom(skb) < TKIP_IV_LEN))
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.tx.iv16++;
if (key->u.tkip.tx.iv16 == 0)
key->u.tkip.tx.iv32++;
if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
/* hwaccel - with preallocated room for IV */
ieee80211_tkip_add_iv(pos, key, key->u.tkip.tx.iv16);
info->control.hw_key = &tx->key->conf;
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_tx_result
ieee80211_crypto_tkip_encrypt(struct ieee80211_tx_data *tx)
{
struct sk_buff *skb = tx->skb;
ieee80211_tx_set_protected(tx);
if (tkip_encrypt_skb(tx, skb) < 0)
return TX_DROP;
if (tx->extra_frag) {
int i;
for (i = 0; i < tx->num_extra_frag; i++) {
if (tkip_encrypt_skb(tx, tx->extra_frag[i]) < 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, wpa_test = 0;
struct ieee80211_key *key = rx->key;
struct sk_buff *skb = rx->skb;
DECLARE_MAC_BUF(mac);
hdrlen = ieee80211_hdrlen(hdr->frame_control);
if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
return RX_CONTINUE;
if (!rx->sta || skb->len - hdrlen < 12)
return RX_DROP_UNUSABLE;
if (rx->status->flag & RX_FLAG_DECRYPTED) {
if (rx->status->flag & RX_FLAG_IV_STRIPPED) {
/*
* Hardware took care of all processing, including
* replay protection, and stripped the ICV/IV so
* we cannot do any checks here.
*/
return RX_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,
hdr->addr1, hwaccel, rx->queue,
&rx->tkip_iv32,
&rx->tkip_iv16);
if (res != TKIP_DECRYPT_OK || wpa_test)
return RX_DROP_UNUSABLE;
/* 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 RX_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_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, *pn, *b_0, *aad, *scratch;
int i;
info->control.icv_len = CCMP_MIC_LEN;
info->control.iv_len = CCMP_HDR_LEN;
if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
!(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV)) {
/* hwaccel - with no need for preallocated room for CCMP "
* header or MIC fields */
info->control.hw_key = &tx->key->conf;
return 0;
}
scratch = key->u.ccmp.tx_crypto_buf;
b_0 = scratch + 3 * AES_BLOCK_LEN;
aad = scratch + 4 * AES_BLOCK_LEN;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
len = skb->len - hdrlen;
if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
tail = 0;
else
tail = CCMP_MIC_LEN;
if (WARN_ON(skb_tailroom(skb) < tail ||
skb_headroom(skb) < CCMP_HDR_LEN))
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->conf.keyidx);
if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
/* hwaccel - with preallocated room for CCMP header */
info->control.hw_key = &tx->key->conf;
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_tx_result
ieee80211_crypto_ccmp_encrypt(struct ieee80211_tx_data *tx)
{
struct sk_buff *skb = tx->skb;
ieee80211_tx_set_protected(tx);
if (ccmp_encrypt_skb(tx, skb) < 0)
return TX_DROP;
if (tx->extra_frag) {
int i;
for (i = 0; i < tx->num_extra_frag; i++) {
if (ccmp_encrypt_skb(tx, tx->extra_frag[i]) < 0)
return TX_DROP;
}
}
return TX_CONTINUE;
}
ieee80211_rx_result
ieee80211_crypto_ccmp_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;
u8 pn[CCMP_PN_LEN];
int data_len;
DECLARE_MAC_BUF(mac);
hdrlen = ieee80211_hdrlen(hdr->frame_control);
if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)
return RX_CONTINUE;
data_len = skb->len - hdrlen - CCMP_HDR_LEN - CCMP_MIC_LEN;
if (!rx->sta || data_len < 0)
return RX_DROP_UNUSABLE;
if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
(rx->status->flag & RX_FLAG_IV_STRIPPED))
return RX_CONTINUE;
(void) ccmp_hdr2pn(pn, skb->data + hdrlen);
if (memcmp(pn, key->u.ccmp.rx_pn[rx->queue], CCMP_PN_LEN) <= 0) {
key->u.ccmp.replays++;
return RX_DROP_UNUSABLE;
}
if (!(rx->status->flag & RX_FLAG_DECRYPTED)) {
/* hardware didn't decrypt/verify MIC */
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)) {
return RX_DROP_UNUSABLE;
}
}
memcpy(key->u.ccmp.rx_pn[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 RX_CONTINUE;
}