void devif_iob_send(FAR struct net_driver_s *dev, FAR struct iob_s *iob,
unsigned int len, unsigned int offset)
{
DEBUGASSERT(dev && len > 0 && len < NET_DEV_MTU(dev));
/* Copy the data from the I/O buffer chain to the device buffer */
iob_copyout(dev->d_snddata, iob, len, offset);
dev->d_sndlen = len;
#ifdef CONFIG_NET_TCP_WRBUFFER_DUMP
/* Dump the outgoing device buffer */
lib_dumpbuffer("devif_iob_send", dev->d_snddata, len);
#endif
}
struct iob_s *ieee80211_ccmp_decrypt(struct ieee80211_s *ic, struct iob_s *iob0,
struct ieee80211_key *k)
{
struct ieee80211_ccmp_ctx *ctx = k->k_priv;
struct ieee80211_frame *wh;
uint64_t pn, *prsc;
const uint8_t *ivp;
const uint8_t *src;
uint8_t *dst;
uint8_t mic0[IEEE80211_CCMP_MICLEN];
uint8_t a[16];
uint8_t b[16];
uint8_t s0[16];
uint8_t s[16];
struct iob_s *next0;
struct iob_s *iob;
struct iob_s *next;
int hdrlen;
int left;
int moff;
int noff;
int len;
uint16_t ctr;
int i;
int j;
wh = (FAR struct ieee80211_frame *)IOB_DATA(iob0);
hdrlen = ieee80211_get_hdrlen(wh);
ivp = (uint8_t *) wh + hdrlen;
if (iob0->io_pktlen < hdrlen + IEEE80211_CCMP_HDRLEN + IEEE80211_CCMP_MICLEN)
{
iob_free_chain(iob0);
return NULL;
}
/* Check that ExtIV bit is set */
if (!(ivp[3] & IEEE80211_WEP_EXTIV))
{
iob_free_chain(iob0);
return NULL;
}
/* Retrieve last seen packet number for this frame type/priority */
if ((wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_DATA)
{
uint8_t tid =
ieee80211_has_qos(wh) ? ieee80211_get_qos(wh) & IEEE80211_QOS_TID : 0;
prsc = &k->k_rsc[tid];
}
else
{
/* 11w: management frames have their own counters */
prsc = &k->k_mgmt_rsc;
}
/* Extract the 48-bit PN from the CCMP header */
pn = (uint64_t) ivp[0] |
(uint64_t) ivp[1] << 8 |
(uint64_t) ivp[4] << 16 |
(uint64_t) ivp[5] << 24 | (uint64_t) ivp[6] << 32 | (uint64_t) ivp[7] << 40;
if (pn <= *prsc)
{
/* Replayed frame, discard */
iob_free_chain(iob0);
return NULL;
}
next0 = iob_alloc(false);
if (next0 == NULL)
{
goto nospace;
}
if (iob_clone(next0, iob0) < 0)
{
goto nospace;
}
next0->io_pktlen -= IEEE80211_CCMP_HDRLEN + IEEE80211_CCMP_MICLEN;
next0->io_len = CONFIG_IEEE80211_BUFSIZE;
if (next0->io_len > next0->io_pktlen)
{
next0->io_len = next0->io_pktlen;
}
/* Construct initial B, A and S_0 blocks */
ieee80211_ccmp_phase1(&ctx->rijndael, wh, pn,
next0->io_pktlen - hdrlen, b, a, s0);
/* Copy 802.11 header and clear protected bit */
memcpy(IOB_DATA(next0), wh, hdrlen);
wh = (FAR struct ieee80211_frame *)IOB_DATA(next0);
wh->i_fc[1] &= ~IEEE80211_FC1_PROTECTED;
/* construct S_1 */
ctr = 1;
a[14] = ctr >> 8;
a[15] = ctr & 0xff;
rijndael_encrypt(&ctx->rijndael, a, s);
/* decrypt frame body and compute MIC */
j = 0;
iob = iob0;
next = next0;
moff = hdrlen + IEEE80211_CCMP_HDRLEN;
noff = hdrlen;
left = next0->io_pktlen - noff;
while (left > 0)
{
if (moff == iob->io_len)
{
/* Nothing left to copy from iob */
iob = iob->io_flink;
moff = 0;
}
if (noff == next->io_len)
{
struct iob_s *newbuf;
/* next is full and there's more data to copy */
newbuf = iob_alloc(false);
if (newbuf == NULL)
{
goto nospace;
}
next->io_flink = newbuf;
next = newbuf;
next->io_len = 0;
if (next->io_len > left)
{
next->io_len = left;
}
noff = 0;
}
len = MIN(iob->io_len - moff, next->io_len - noff);
src = (FAR uint8_t *) IOB_DATA(iob) + moff;
dst = (FAR uint8_t *) IOB_DATA(next) + noff;
for (i = 0; i < len; i++)
{
/* decrypt message */
dst[i] = src[i] ^ s[j];
/* update MIC with clear text */
b[j] ^= dst[i];
if (++j < 16)
continue;
/* we have a full block, encrypt MIC */
rijndael_encrypt(&ctx->rijndael, b, b);
/* construct a new S_ctr block */
ctr++;
a[14] = ctr >> 8;
a[15] = ctr & 0xff;
rijndael_encrypt(&ctx->rijndael, a, s);
j = 0;
}
moff += len;
noff += len;
left -= len;
}
if (j != 0)
{
/* Partial block, encrypt MIC */
rijndael_encrypt(&ctx->rijndael, b, b);
}
/* Finalize MIC, U := T XOR first-M-bytes( S_0 ) */
for (i = 0; i < IEEE80211_CCMP_MICLEN; i++)
b[i] ^= s0[i];
/* Check that it matches the MIC in received frame */
iob_copyout(mic0, iob, moff, IEEE80211_CCMP_MICLEN);
if (memcmp(mic0, b, IEEE80211_CCMP_MICLEN) != 0)
{
iob_free_chain(iob0);
iob_free_chain(next0);
return NULL;
}
/* update last seen packet number (MIC is validated) */
*prsc = pn;
iob_free_chain(iob0);
return next0;
nospace:
iob_free_chain(iob0);
if (next0 != NULL)
{
iob_free_chain(next0);
}
return NULL;
}