struct mbuf *
ieee80211_ccmp_decrypt(struct ieee80211com *ic, struct mbuf *m0,
struct ieee80211_key *k)
{
struct ieee80211_ccmp_ctx *ctx = k->k_priv;
struct ieee80211_frame *wh;
u_int64_t pn, *prsc;
const u_int8_t *ivp, *src;
u_int8_t *dst;
u_int8_t mic0[IEEE80211_CCMP_MICLEN];
u_int8_t a[16], b[16], s0[16], s[16];
struct mbuf *n0, *m, *n;
int hdrlen, left, moff, noff, len;
u_int16_t ctr;
int i, j;
wh = mtod(m0, struct ieee80211_frame *);
hdrlen = ieee80211_get_hdrlen(wh);
ivp = (u_int8_t *)wh + hdrlen;
if (m0->m_pkthdr.len < hdrlen + IEEE80211_CCMP_HDRLEN +
IEEE80211_CCMP_MICLEN) {
m_freem(m0);
return NULL;
}
/* check that ExtIV bit is set */
if (!(ivp[3] & IEEE80211_WEP_EXTIV)) {
m_freem(m0);
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) {
u_int8_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 = (u_int64_t)ivp[0] |
(u_int64_t)ivp[1] << 8 |
(u_int64_t)ivp[4] << 16 |
(u_int64_t)ivp[5] << 24 |
(u_int64_t)ivp[6] << 32 |
(u_int64_t)ivp[7] << 40;
if (pn <= *prsc) {
/* replayed frame, discard */
ic->ic_stats.is_ccmp_replays++;
m_freem(m0);
return NULL;
}
MGET(n0, M_DONTWAIT, m0->m_type);
if (n0 == NULL)
goto nospace;
if (m_dup_pkthdr(n0, m0, M_DONTWAIT))
goto nospace;
n0->m_pkthdr.len -= IEEE80211_CCMP_HDRLEN + IEEE80211_CCMP_MICLEN;
n0->m_len = MHLEN;
if (n0->m_pkthdr.len >= MINCLSIZE) {
MCLGET(n0, M_DONTWAIT);
if (n0->m_flags & M_EXT)
n0->m_len = n0->m_ext.ext_size;
}
if (n0->m_len > n0->m_pkthdr.len)
n0->m_len = n0->m_pkthdr.len;
/* construct initial B, A and S_0 blocks */
ieee80211_ccmp_phase1(&ctx->rijndael, wh, pn,
n0->m_pkthdr.len - hdrlen, b, a, s0);
/* copy 802.11 header and clear protected bit */
memcpy(mtod(n0, caddr_t), wh, hdrlen);
wh = mtod(n0, struct ieee80211_frame *);
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;
m = m0;
n = n0;
moff = hdrlen + IEEE80211_CCMP_HDRLEN;
noff = hdrlen;
left = n0->m_pkthdr.len - noff;
while (left > 0) {
if (moff == m->m_len) {
/* nothing left to copy from m */
m = m->m_next;
moff = 0;
}
if (noff == n->m_len) {
/* n is full and there's more data to copy */
MGET(n->m_next, M_DONTWAIT, n->m_type);
if (n->m_next == NULL)
goto nospace;
n = n->m_next;
n->m_len = MLEN;
if (left >= MINCLSIZE) {
MCLGET(n, M_DONTWAIT);
if (n->m_flags & M_EXT)
n->m_len = n->m_ext.ext_size;
}
if (n->m_len > left)
n->m_len = left;
noff = 0;
}
len = min(m->m_len - moff, n->m_len - noff);
src = mtod(m, u_int8_t *) + moff;
dst = mtod(n, u_int8_t *) + 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 */
m_copydata(m, moff, IEEE80211_CCMP_MICLEN, mic0);
if (timingsafe_bcmp(mic0, b, IEEE80211_CCMP_MICLEN) != 0) {
ic->ic_stats.is_ccmp_dec_errs++;
m_freem(m0);
m_freem(n0);
return NULL;
}
/* update last seen packet number (MIC is validated) */
*prsc = pn;
m_freem(m0);
return n0;
nospace:
ic->ic_stats.is_rx_nombuf++;
m_freem(m0);
if (n0 != NULL)
m_freem(n0);
return NULL;
}
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;
}
struct mbuf *
ieee80211_ccmp_encrypt(struct ieee80211com *ic, struct mbuf *m0,
struct ieee80211_key *k)
{
struct ieee80211_ccmp_ctx *ctx = k->k_priv;
const struct ieee80211_frame *wh;
const u_int8_t *src;
u_int8_t *ivp, *mic, *dst;
u_int8_t a[16], b[16], s0[16], s[16];
struct mbuf *n0, *m, *n;
int hdrlen, left, moff, noff, len;
u_int16_t ctr;
int i, j;
MGET(n0, M_DONTWAIT, m0->m_type);
if (n0 == NULL)
goto nospace;
if (m_dup_pkthdr(n0, m0, M_DONTWAIT))
goto nospace;
n0->m_pkthdr.len += IEEE80211_CCMP_HDRLEN;
n0->m_len = MHLEN;
if (n0->m_pkthdr.len >= MINCLSIZE - IEEE80211_CCMP_MICLEN) {
MCLGET(n0, M_DONTWAIT);
if (n0->m_flags & M_EXT)
n0->m_len = n0->m_ext.ext_size;
}
if (n0->m_len > n0->m_pkthdr.len)
n0->m_len = n0->m_pkthdr.len;
/* copy 802.11 header */
wh = mtod(m0, struct ieee80211_frame *);
hdrlen = ieee80211_get_hdrlen(wh);
memcpy(mtod(n0, caddr_t), wh, hdrlen);
k->k_tsc++; /* increment the 48-bit PN */
/* construct CCMP header */
ivp = mtod(n0, u_int8_t *) + hdrlen;
ivp[0] = k->k_tsc; /* PN0 */
ivp[1] = k->k_tsc >> 8; /* PN1 */
ivp[2] = 0; /* Rsvd */
ivp[3] = k->k_id << 6 | IEEE80211_WEP_EXTIV; /* KeyID | ExtIV */
ivp[4] = k->k_tsc >> 16; /* PN2 */
ivp[5] = k->k_tsc >> 24; /* PN3 */
ivp[6] = k->k_tsc >> 32; /* PN4 */
ivp[7] = k->k_tsc >> 40; /* PN5 */
/* construct initial B, A and S_0 blocks */
ieee80211_ccmp_phase1(&ctx->rijndael, wh, k->k_tsc,
m0->m_pkthdr.len - hdrlen, b, a, s0);
/* construct S_1 */
ctr = 1;
a[14] = ctr >> 8;
a[15] = ctr & 0xff;
rijndael_encrypt(&ctx->rijndael, a, s);
/* encrypt frame body and compute MIC */
j = 0;
m = m0;
n = n0;
moff = hdrlen;
noff = hdrlen + IEEE80211_CCMP_HDRLEN;
left = m0->m_pkthdr.len - moff;
while (left > 0) {
if (moff == m->m_len) {
/* nothing left to copy from m */
m = m->m_next;
moff = 0;
}
if (noff == n->m_len) {
/* n is full and there's more data to copy */
MGET(n->m_next, M_DONTWAIT, n->m_type);
if (n->m_next == NULL)
goto nospace;
n = n->m_next;
n->m_len = MLEN;
if (left >= MINCLSIZE - IEEE80211_CCMP_MICLEN) {
MCLGET(n, M_DONTWAIT);
if (n->m_flags & M_EXT)
n->m_len = n->m_ext.ext_size;
}
if (n->m_len > left)
n->m_len = left;
noff = 0;
}
len = min(m->m_len - moff, n->m_len - noff);
src = mtod(m, u_int8_t *) + moff;
dst = mtod(n, u_int8_t *) + noff;
for (i = 0; i < len; i++) {
/* update MIC with clear text */
b[j] ^= src[i];
/* encrypt message */
dst[i] = src[i] ^ s[j];
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);
/* reserve trailing space for MIC */
if (M_TRAILINGSPACE(n) < IEEE80211_CCMP_MICLEN) {
MGET(n->m_next, M_DONTWAIT, n->m_type);
if (n->m_next == NULL)
goto nospace;
n = n->m_next;
n->m_len = 0;
}
/* finalize MIC, U := T XOR first-M-bytes( S_0 ) */
mic = mtod(n, u_int8_t *) + n->m_len;
for (i = 0; i < IEEE80211_CCMP_MICLEN; i++)
mic[i] = b[i] ^ s0[i];
n->m_len += IEEE80211_CCMP_MICLEN;
n0->m_pkthdr.len += IEEE80211_CCMP_MICLEN;
m_freem(m0);
return n0;
nospace:
ic->ic_stats.is_tx_nombuf++;
m_freem(m0);
if (n0 != NULL)
m_freem(n0);
return NULL;
}
struct iob_s *ieee80211_ccmp_encrypt(struct ieee80211_s *ic, struct iob_s *iob0,
struct ieee80211_key *k)
{
struct ieee80211_ccmp_ctx *ctx = k->k_priv;
const struct ieee80211_frame *wh;
const uint8_t *src;
uint8_t *ivp, *mic, *dst;
uint8_t a[16], b[16], s0[16], s[16];
struct iob_s *next0, *iob, *next;
int hdrlen, left, moff, noff, len;
uint16_t ctr;
int i, j;
next0 = iob_alloc(false);
if (next0 == NULL)
{
goto nospace;
}
if (iob_clone(next0, iob0) < 0)
{
goto nospace;
}
next0->io_pktlen += IEEE80211_CCMP_HDRLEN;
next0->io_len = CONFIG_IEEE80211_BUFSIZE;
if (next0->io_len > next0->io_pktlen)
{
next0->io_len = next0->io_pktlen;
}
/* Copy 802.11 header */
wh = (FAR struct ieee80211_frame *)IOB_DATA(iob0);
hdrlen = ieee80211_get_hdrlen(wh);
memcpy(IOB_DATA(next0), wh, hdrlen);
k->k_tsc++; /* increment the 48-bit PN */
/* construct CCMP header */
ivp = (FAR uint8_t *) IOB_DATA(next0) + hdrlen;
ivp[0] = k->k_tsc; /* PN0 */
ivp[1] = k->k_tsc >> 8; /* PN1 */
ivp[2] = 0; /* Rsvd */
ivp[3] = k->k_id << 6 | IEEE80211_WEP_EXTIV; /* KeyID | ExtIV */
ivp[4] = k->k_tsc >> 16; /* PN2 */
ivp[5] = k->k_tsc >> 24; /* PN3 */
ivp[6] = k->k_tsc >> 32; /* PN4 */
ivp[7] = k->k_tsc >> 40; /* PN5 */
/* construct initial B, A and S_0 blocks */
ieee80211_ccmp_phase1(&ctx->rijndael, wh, k->k_tsc,
iob0->io_pktlen - hdrlen, b, a, s0);
/* construct S_1 */
ctr = 1;
a[14] = ctr >> 8;
a[15] = ctr & 0xff;
rijndael_encrypt(&ctx->rijndael, a, s);
/* encrypt frame body and compute MIC */
j = 0;
iob = iob0;
next = next0;
moff = hdrlen;
noff = hdrlen + IEEE80211_CCMP_HDRLEN;
left = iob0->io_pktlen - moff;
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++)
{
/* update MIC with clear text */
b[j] ^= src[i];
/* encrypt message */
dst[i] = src[i] ^ s[j];
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);
/* Reserve trailing space for MIC */
if (IOB_FREESPACE(next) < IEEE80211_CCMP_MICLEN)
{
struct iob_s *newbuf;
newbuf = iob_alloc(false);
if (newbuf == NULL)
{
goto nospace;
}
next->io_flink = newbuf;
next = newbuf;
next->io_len = 0;
}
/* Finalize MIC, U := T XOR first-M-bytes( S_0 ) */
mic = (FAR uint8_t *) IOB_DATA(next) + next->io_len;
for (i = 0; i < IEEE80211_CCMP_MICLEN; i++)
{
mic[i] = b[i] ^ s0[i];
}
next->io_len += IEEE80211_CCMP_MICLEN;
next0->io_pktlen += IEEE80211_CCMP_MICLEN;
iob_free_chain(iob0);
return next0;
nospace:
iob_free_chain(iob0);
if (next0 != NULL)
{
iob_free_chain(next0);
}
return NULL;
}
