int ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm, struct sk_buff *skb,
const u64 pn, size_t mic_len)
{
u8 aad[2 * AES_BLOCK_SIZE];
u8 b_0[AES_BLOCK_SIZE];
u8 *data, *mic;
size_t data_len, hdr_len;
struct ieee80211_hdr *hdr = (void *)skb->data;
struct scatterlist sg[3];
char aead_req_data[sizeof(struct aead_request) +
crypto_aead_reqsize(tfm)]
__aligned(__alignof__(struct aead_request));
struct aead_request *aead_req = (void *) aead_req_data;
hdr_len = ieee80211_hdrlen(hdr->frame_control);
data_len = skb->len - hdr_len - mic_len;
if (data_len <= 0)
return -EINVAL;
ccmp_special_blocks(hdr, hdr_len, pn, b_0, aad);
memset(aead_req, 0, sizeof(aead_req_data));
mic = skb->data + skb->len - mic_len;
data = skb->data + hdr_len;
sg_init_table(sg, 3);
sg_set_buf(&sg[0], &aad[2], be16_to_cpup((__be16 *)aad));
sg_set_buf(&sg[1], data, data_len);
sg_set_buf(&sg[2], mic, mic_len);
aead_request_set_tfm(aead_req, tfm);
aead_request_set_crypt(aead_req, sg, sg, data_len + mic_len, b_0);
aead_request_set_ad(aead_req, sg[0].length);
return crypto_aead_decrypt(aead_req);
}
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;
int i;
bool skip_hw;
skip_hw = (tx->key->conf.flags & IEEE80211_KEY_FLAG_SW_MGMT) &&
ieee80211_is_mgmt(hdr->frame_control);
if ((tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) &&
!(tx->key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV) &&
!skip_hw) {
/* hwaccel - with no need for preallocated room for CCMP
* header or MIC fields */
info->control.hw_key = &tx->key->conf;
return 0;
}
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) && !skip_hw) {
/* 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, key->u.ccmp.tx_crypto_buf, 0);
ieee80211_aes_ccm_encrypt(key->u.ccmp.tfm, key->u.ccmp.tx_crypto_buf, pos, len,
pos, skb_put(skb, CCMP_MIC_LEN));
return 0;
}
