Skip to content

Commit

Permalink
[PATCH] ieee80211: Add TKIP crypt->build_iv
Browse files Browse the repository at this point in the history 
This patch adds ieee80211 TKIP build_iv() method to support hardwares
that can do TKIP encryption but relies on ieee80211 layer to build
the IV. It also changes the build_iv() interface to return the key
if possible after the IV is built (this is required by TKIP).

Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
  • Loading branch information
Zhu Yi authored and John W. Linville committed Jan 27, 2006
1 parent 41a25c6 commit 9184d93
Show file tree
Hide file tree
Showing 5 changed files with 41 additions and 32 deletions.
3 changes: 2 additions & 1 deletion include/net/ieee80211_crypt.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -47,7 +47,8 @@ struct ieee80211_crypto_ops {
/* deinitialize crypto context and free allocated private data */
void (*deinit) (void *priv);

int (*build_iv) (struct sk_buff * skb, int hdr_len, void *priv);
int (*build_iv) (struct sk_buff * skb, int hdr_len,
u8 *key, int keylen, void *priv);

/* encrypt/decrypt return < 0 on error or >= 0 on success. The return
* value from decrypt_mpdu is passed as the keyidx value for
Expand Down
8 changes: 6 additions & 2 deletions net/ieee80211/ieee80211_crypt_ccmp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -190,7 +190,8 @@ static void ccmp_init_blocks(struct crypto_tfm *tfm,
ieee80211_ccmp_aes_encrypt(tfm, b0, s0);
}

static int ieee80211_ccmp_hdr(struct sk_buff *skb, int hdr_len, void *priv)
static int ieee80211_ccmp_hdr(struct sk_buff *skb, int hdr_len,
u8 *aeskey, int keylen, void *priv)
{
struct ieee80211_ccmp_data *key = priv;
int i;
Expand All @@ -199,6 +200,9 @@ static int ieee80211_ccmp_hdr(struct sk_buff *skb, int hdr_len, void *priv)
if (skb_headroom(skb) < CCMP_HDR_LEN || skb->len < hdr_len)
return -1;

if (aeskey != NULL && keylen >= CCMP_TK_LEN)
memcpy(aeskey, key->key, CCMP_TK_LEN);

pos = skb_push(skb, CCMP_HDR_LEN);
memmove(pos, pos + CCMP_HDR_LEN, hdr_len);
pos += hdr_len;
Expand Down Expand Up @@ -238,7 +242,7 @@ static int ieee80211_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
return -1;

data_len = skb->len - hdr_len;
len = ieee80211_ccmp_hdr(skb, hdr_len, priv);
len = ieee80211_ccmp_hdr(skb, hdr_len, NULL, 0, priv);
if (len < 0)
return -1;

Expand Down
53 changes: 27 additions & 26 deletions net/ieee80211/ieee80211_crypt_tkip.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -270,34 +270,33 @@ static void tkip_mixing_phase2(u8 * WEPSeed, const u8 * TK, const u16 * TTAK,
#endif
}

static u8 *ieee80211_tkip_hdr(struct sk_buff *skb, int hdr_len, void *priv)
static int ieee80211_tkip_hdr(struct sk_buff *skb, int hdr_len,
u8 * rc4key, int keylen, void *priv)
{
struct ieee80211_tkip_data *tkey = priv;
int len;
u8 *rc4key, *pos, *icv;
u8 *pos;
struct ieee80211_hdr_4addr *hdr;
u32 crc;

hdr = (struct ieee80211_hdr_4addr *)skb->data;

if (skb_headroom(skb) < 8 || skb->len < hdr_len)
return NULL;
return -1;

if (rc4key == NULL || keylen < 16)
return -1;

if (!tkey->tx_phase1_done) {
tkip_mixing_phase1(tkey->tx_ttak, tkey->key, hdr->addr2,
tkey->tx_iv32);
tkey->tx_phase1_done = 1;
}
rc4key = kmalloc(16, GFP_ATOMIC);
if (!rc4key)
return NULL;
tkip_mixing_phase2(rc4key, tkey->key, tkey->tx_ttak, tkey->tx_iv16);

len = skb->len - hdr_len;
pos = skb_push(skb, 8);
memmove(pos, pos + 8, hdr_len);
pos += hdr_len;
icv = skb_put(skb, 4);

*pos++ = *rc4key;
*pos++ = *(rc4key + 1);
Expand All @@ -308,28 +307,28 @@ static u8 *ieee80211_tkip_hdr(struct sk_buff *skb, int hdr_len, void *priv)
*pos++ = (tkey->tx_iv32 >> 16) & 0xff;
*pos++ = (tkey->tx_iv32 >> 24) & 0xff;

crc = ~crc32_le(~0, pos, len);
icv[0] = crc;
icv[1] = crc >> 8;
icv[2] = crc >> 16;
icv[3] = crc >> 24;
tkey->tx_iv16++;
if (tkey->tx_iv16 == 0) {
tkey->tx_phase1_done = 0;
tkey->tx_iv32++;
}

return rc4key;
return 8;
}

static int ieee80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
{
struct ieee80211_tkip_data *tkey = priv;
int len;
const u8 *rc4key;
u8 *pos;
u8 rc4key[16], *pos, *icv;
u32 crc;
struct scatterlist sg;

if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
if (net_ratelimit()) {
struct ieee80211_hdr_4addr *hdr =
(struct ieee80211_hdr_4addr *)skb->data;
printk(KERN_DEBUG "TKIP countermeasures: dropped "
printk(KERN_DEBUG ": TKIP countermeasures: dropped "
"TX packet to " MAC_FMT "\n",
MAC_ARG(hdr->addr1));
}
Expand All @@ -342,22 +341,23 @@ static int ieee80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
len = skb->len - hdr_len;
pos = skb->data + hdr_len;

rc4key = ieee80211_tkip_hdr(skb, hdr_len, priv);
if (!rc4key)
if ((ieee80211_tkip_hdr(skb, hdr_len, rc4key, 16, priv)) < 0)
return -1;

icv = skb_put(skb, 4);

crc = ~crc32_le(~0, pos, len);
icv[0] = crc;
icv[1] = crc >> 8;
icv[2] = crc >> 16;
icv[3] = crc >> 24;

crypto_cipher_setkey(tkey->tfm_arc4, rc4key, 16);
sg.page = virt_to_page(pos);
sg.offset = offset_in_page(pos);
sg.length = len + 4;
crypto_cipher_encrypt(tkey->tfm_arc4, &sg, &sg, len + 4);

tkey->tx_iv16++;
if (tkey->tx_iv16 == 0) {
tkey->tx_phase1_done = 0;
tkey->tx_iv32++;
}

return 0;
}

Expand All @@ -378,7 +378,7 @@ static int ieee80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)

if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
if (net_ratelimit()) {
printk(KERN_DEBUG "TKIP countermeasures: dropped "
printk(KERN_DEBUG ": TKIP countermeasures: dropped "
"received packet from " MAC_FMT "\n",
MAC_ARG(hdr->addr2));
}
Expand Down Expand Up @@ -694,6 +694,7 @@ static struct ieee80211_crypto_ops ieee80211_crypt_tkip = {
.name = "TKIP",
.init = ieee80211_tkip_init,
.deinit = ieee80211_tkip_deinit,
.build_iv = ieee80211_tkip_hdr,
.encrypt_mpdu = ieee80211_tkip_encrypt,
.decrypt_mpdu = ieee80211_tkip_decrypt,
.encrypt_msdu = ieee80211_michael_mic_add,
Expand Down
5 changes: 3 additions & 2 deletions net/ieee80211/ieee80211_crypt_wep.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -76,7 +76,8 @@ static void prism2_wep_deinit(void *priv)
}

/* Add WEP IV/key info to a frame that has at least 4 bytes of headroom */
static int prism2_wep_build_iv(struct sk_buff *skb, int hdr_len, void *priv)
static int prism2_wep_build_iv(struct sk_buff *skb, int hdr_len,
u8 *key, int keylen, void *priv)
{
struct prism2_wep_data *wep = priv;
u32 klen, len;
Expand Down Expand Up @@ -131,7 +132,7 @@ static int prism2_wep_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
return -1;

/* add the IV to the frame */
if (prism2_wep_build_iv(skb, hdr_len, priv))
if (prism2_wep_build_iv(skb, hdr_len, NULL, 0, priv))
return -1;

/* Copy the IV into the first 3 bytes of the key */
Expand Down
4 changes: 3 additions & 1 deletion net/ieee80211/ieee80211_tx.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -470,7 +470,9 @@ int ieee80211_xmit(struct sk_buff *skb, struct net_device *dev)
atomic_inc(&crypt->refcnt);
if (crypt->ops->build_iv)
crypt->ops->build_iv(skb_frag, hdr_len,
crypt->priv);
ieee->sec.keys[ieee->sec.active_key],
ieee->sec.key_sizes[ieee->sec.active_key],
crypt->priv);
atomic_dec(&crypt->refcnt);
}

Expand Down

0 comments on commit 9184d93

Please sign in to comment.