linux/net/mac80211/wpa.c
John W. Linville 7f3ad8943e mac80211: make "decrypt failed" messages conditional upon MAC80211_DEBUG
Make "decrypt failed" and "have no key" debugging messages compile
conditionally upon CONFIG_MAC80211_DEBUG.  They have been useful for
finding certain problems in the past, but in many cases they just
clutter a user's logs.

A typical example is an enviornment where multiple SSIDs are using a
single BSSID but with different protection schemes or different keys
for each SSID.  In such an environment these messages are just noise.
Let's just leave them for those interested enough to turn-on debugging.

Signed-off-by: John W. Linville <linville@tuxdriver.com>
2007-11-10 22:01:34 -08:00

618 lines
16 KiB
C

/*
* 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;
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->conf.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->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
!(tx->flags & IEEE80211_TXRXD_FRAGMENTED) &&
!(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_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->conf.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;
DECLARE_MAC_BUF(mac);
fc = rx->fc;
/*
* No way to verify the MIC if the hardware stripped it
*/
if (rx->u.rx.status->flag & RX_FLAG_MMIC_STRIPPED)
return TXRX_CONTINUE;
if (!rx->key || rx->key->conf.alg != ALG_TKIP ||
!(rx->fc & IEEE80211_FCTL_PROTECTED) || !WLAN_FC_DATA_PRESENT(fc))
return TXRX_CONTINUE;
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->conf.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->flags & IEEE80211_TXRXD_RXRA_MATCH))
return TXRX_DROP;
printk(KERN_DEBUG "%s: invalid Michael MIC in data frame from "
"%s\n", rx->dev->name, print_mac(mac, sa));
mac80211_ev_michael_mic_failure(rx->dev, rx->key->conf.keyidx,
(void *) skb->data);
return TXRX_DROP;
}
/* 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.iv32_rx[rx->u.rx.queue] = rx->u.rx.tkip_iv32;
rx->key->u.tkip.iv16_rx[rx->u.rx.queue] = rx->u.rx.tkip_iv16;
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;
if (tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
tailneed = 0;
else
tailneed = 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->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
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);
tx->u.tx.control->key_idx = tx->key->conf.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_crypto_tkip_encrypt(struct ieee80211_txrx_data *tx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
u16 fc;
struct sk_buff *skb = tx->skb;
int wpa_test = 0, test = 0;
fc = le16_to_cpu(hdr->frame_control);
if (!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->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
!(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
!wpa_test) {
/* hwaccel - with no need for preallocated room for IV/ICV */
tx->u.tx.control->key_idx = tx->key->conf.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_crypto_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;
DECLARE_MAC_BUF(mac);
fc = le16_to_cpu(hdr->frame_control);
hdrlen = ieee80211_get_hdrlen(fc);
if ((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) {
if (rx->u.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 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,
&rx->u.rx.tkip_iv32,
&rx->u.rx.tkip_iv16);
if (res != TKIP_DECRYPT_OK || wpa_test) {
#ifdef CONFIG_MAC80211_DEBUG
if (net_ratelimit())
printk(KERN_DEBUG "%s: TKIP decrypt failed for RX "
"frame from %s (res=%d)\n", rx->dev->name,
print_mac(mac, rx->sta->addr), res);
#endif /* CONFIG_MAC80211_DEBUG */
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;
if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
tailneed = 0;
else
tailneed = 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->conf.keyidx);
if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
/* hwaccel - with preallocated room for CCMP header */
tx->u.tx.control->key_idx = key->conf.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_crypto_ccmp_encrypt(struct ieee80211_txrx_data *tx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
u16 fc;
struct sk_buff *skb = tx->skb;
int test = 0;
fc = le16_to_cpu(hdr->frame_control);
if (!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->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 */
tx->u.tx.control->key_idx = tx->key->conf.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_crypto_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;
DECLARE_MAC_BUF(mac);
fc = le16_to_cpu(hdr->frame_control);
hdrlen = ieee80211_get_hdrlen(fc);
if ((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) &&
(rx->u.rx.status->flag & RX_FLAG_IV_STRIPPED))
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 "
"%s (RX PN %02x%02x%02x%02x%02x%02x <= prev. PN "
"%02x%02x%02x%02x%02x%02x)\n", rx->dev->name,
print_mac(mac, 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)) {
/* 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)) {
#ifdef CONFIG_MAC80211_DEBUG
if (net_ratelimit())
printk(KERN_DEBUG "%s: CCMP decrypt failed "
"for RX frame from %s\n", rx->dev->name,
print_mac(mac, rx->sta->addr));
#endif /* CONFIG_MAC80211_DEBUG */
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;
}