u8 * ccmp_256_encrypt(const u8 *tk, u8 *frame, size_t len, size_t hdrlen,
u8 *qos, u8 *pn, int keyid, size_t *encrypted_len)
{
u8 aad[30], nonce[13];
size_t aad_len, plen;
u8 *crypt, *pos;
struct ieee80211_hdr *hdr;
if (len < hdrlen || hdrlen < 24)
return NULL;
plen = len - hdrlen;
crypt = os_malloc(hdrlen + 8 + plen + 16 + AES_BLOCK_SIZE);
if (crypt == NULL)
return NULL;
os_memcpy(crypt, frame, hdrlen);
hdr = (struct ieee80211_hdr *) crypt;
hdr->frame_control |= host_to_le16(WLAN_FC_ISWEP);
pos = crypt + hdrlen;
*pos++ = pn[5]; /* PN0 */
*pos++ = pn[4]; /* PN1 */
*pos++ = 0x00; /* Rsvd */
*pos++ = 0x20 | (keyid << 6);
*pos++ = pn[3]; /* PN2 */
*pos++ = pn[2]; /* PN3 */
*pos++ = pn[1]; /* PN4 */
*pos++ = pn[0]; /* PN5 */
os_memset(aad, 0, sizeof(aad));
ccmp_aad_nonce(hdr, crypt + hdrlen, aad, &aad_len, nonce);
wpa_hexdump(MSG_EXCESSIVE, "CCMP-256 AAD", aad, aad_len);
wpa_hexdump(MSG_EXCESSIVE, "CCMP-256 nonce", nonce, 13);
if (aes_ccm_ae(tk, 32, nonce, 16, frame + hdrlen, plen, aad, aad_len,
pos, pos + plen) < 0) {
os_free(crypt);
return NULL;
}
wpa_hexdump(MSG_EXCESSIVE, "CCMP-256 encrypted", crypt + hdrlen + 8,
plen);
*encrypted_len = hdrlen + 8 + plen + 16;
return crypt;
}
u8 * ccmp_decrypt(const u8 *tk, const struct ieee80211_hdr *hdr,
const u8 *data, size_t data_len, size_t *decrypted_len)
{
u8 aad[30], nonce[13];
size_t aad_len;
size_t mlen;
u8 *plain;
if (data_len < 8 + 8)
return NULL;
plain = os_malloc(data_len + AES_BLOCK_SIZE);
if (plain == NULL)
return NULL;
mlen = data_len - 8 - 8;
os_memset(aad, 0, sizeof(aad));
ccmp_aad_nonce(hdr, data, aad, &aad_len, nonce);
wpa_hexdump(MSG_EXCESSIVE, "CCMP AAD", aad, aad_len);
wpa_hexdump(MSG_EXCESSIVE, "CCMP nonce", nonce, 13);
if (aes_ccm_ad(tk, 16, nonce, 8, data + 8, mlen, aad, aad_len,
data + 8 + mlen, plain) < 0) {
u16 seq_ctrl = le_to_host16(hdr->seq_ctrl);
wpa_printf(MSG_INFO, "Invalid CCMP MIC in frame: A1=" MACSTR
" A2=" MACSTR " A3=" MACSTR " seq=%u frag=%u",
MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
MAC2STR(hdr->addr3),
WLAN_GET_SEQ_SEQ(seq_ctrl),
WLAN_GET_SEQ_FRAG(seq_ctrl));
os_free(plain);
return NULL;
}
wpa_hexdump(MSG_EXCESSIVE, "CCMP decrypted", plain, mlen);
*decrypted_len = mlen;
return plain;
}
u8 * ccmp_decrypt(const u8 *tk, const struct ieee80211_hdr *hdr,
const u8 *data, size_t data_len, size_t *decrypted_len)
{
u8 aad[2 + 30], nonce[13];
size_t aad_len;
u8 b[AES_BLOCK_SIZE], x[AES_BLOCK_SIZE], a[AES_BLOCK_SIZE];
void *aes;
const u8 *m, *mpos, *mic;
size_t mlen, last;
int i;
u8 *plain, *ppos;
u8 t[8];
if (data_len < 8 + 8)
return NULL;
plain = os_malloc(data_len + AES_BLOCK_SIZE);
if (plain == NULL)
return NULL;
aes = aes_encrypt_init(tk, 16);
if (aes == NULL) {
os_free(plain);
return NULL;
}
m = data + 8;
mlen = data_len - 8 - 8;
last = mlen % AES_BLOCK_SIZE;
os_memset(aad, 0, sizeof(aad));
ccmp_aad_nonce(hdr, data, &aad[2], &aad_len, nonce);
WPA_PUT_BE16(aad, aad_len);
wpa_hexdump(MSG_EXCESSIVE, "CCMP AAD", &aad[2], aad_len);
wpa_hexdump(MSG_EXCESSIVE, "CCMP nonce", nonce, 13);
/* CCM: M=8 L=2, Adata=1, M' = (M-2)/2 = 3, L' = L-1 = 1 */
/* A_i = Flags | Nonce N | Counter i */
a[0] = 0x01; /* Flags = L' */
os_memcpy(&a[1], nonce, 13);
/* Decryption */
mic = data + data_len - 8;
wpa_hexdump(MSG_EXCESSIVE, "CCMP U", mic, 8);
/* U = T XOR S_0; S_0 = E(K, A_0) */
WPA_PUT_BE16(&a[14], 0);
aes_encrypt(aes, a, x);
for (i = 0; i < 8; i++)
t[i] = mic[i] ^ x[i];
wpa_hexdump(MSG_EXCESSIVE, "CCMP T", t, 8);
/* plaintext = msg XOR (S_1 | S_2 | ... | S_n) */
ppos = plain;
mpos = m;
for (i = 1; i <= mlen / AES_BLOCK_SIZE; i++) {
WPA_PUT_BE16(&a[14], i);
/* S_i = E(K, A_i) */
aes_encrypt(aes, a, ppos);
xor_aes_block(ppos, mpos);
ppos += AES_BLOCK_SIZE;
mpos += AES_BLOCK_SIZE;
}
if (last) {
WPA_PUT_BE16(&a[14], i);
aes_encrypt(aes, a, ppos);
/* XOR zero-padded last block */
for (i = 0; i < last; i++)
*ppos++ ^= *mpos++;
}
wpa_hexdump(MSG_EXCESSIVE, "CCMP decrypted", plain, mlen);
/* Authentication */
/* B_0: Flags | Nonce N | l(m) */
b[0] = 0x40 /* Adata */ | (3 /* M' */ << 3) | 1 /* L' */;
os_memcpy(&b[1], nonce, 13);
WPA_PUT_BE16(&b[14], mlen);
wpa_hexdump(MSG_EXCESSIVE, "CCMP B_0", b, AES_BLOCK_SIZE);
aes_encrypt(aes, b, x); /* X_1 = E(K, B_0) */
wpa_hexdump(MSG_EXCESSIVE, "CCMP B_1", aad, AES_BLOCK_SIZE);
xor_aes_block(aad, x);
aes_encrypt(aes, aad, x); /* X_2 = E(K, X_1 XOR B_1) */
wpa_hexdump(MSG_EXCESSIVE, "CCMP B_2", &aad[AES_BLOCK_SIZE],
AES_BLOCK_SIZE);
xor_aes_block(&aad[AES_BLOCK_SIZE], x);
aes_encrypt(aes, &aad[AES_BLOCK_SIZE], x); /* X_3 = E(K, X_2 XOR B_2)
*/
ppos = plain;
for (i = 0; i < mlen / AES_BLOCK_SIZE; i++) {
/* X_i+1 = E(K, X_i XOR B_i) */
xor_aes_block(x, ppos);
ppos += AES_BLOCK_SIZE;
aes_encrypt(aes, x, x);
}
if (last) {
/* XOR zero-padded last block */
for (i = 0; i < last; i++)
x[i] ^= *ppos++;
aes_encrypt(aes, x, x);
}
aes_encrypt_deinit(aes);
if (os_memcmp(x, t, 8) != 0) {
u16 seq_ctrl = le_to_host16(hdr->seq_ctrl);
wpa_printf(MSG_INFO, "Invalid CCMP MIC in frame: A1=" MACSTR
" A2=" MACSTR " A3=" MACSTR " seq=%u frag=%u",
MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
MAC2STR(hdr->addr3),
WLAN_GET_SEQ_SEQ(seq_ctrl),
WLAN_GET_SEQ_FRAG(seq_ctrl));
wpa_hexdump(MSG_DEBUG, "CCMP decrypted", plain, mlen);
os_free(plain);
return NULL;
}
*decrypted_len = mlen;
return plain;
}
u8 * ccmp_encrypt(const u8 *tk, u8 *frame, size_t len, size_t hdrlen, u8 *qos,
u8 *pn, int keyid, size_t *encrypted_len)
{
u8 aad[2 + 30], nonce[13];
size_t aad_len;
u8 b[AES_BLOCK_SIZE], x[AES_BLOCK_SIZE], a[AES_BLOCK_SIZE];
void *aes;
u8 *crypt, *pos, *ppos, *mpos;
size_t plen, last;
struct ieee80211_hdr *hdr;
int i;
if (len < hdrlen || hdrlen < 24)
return NULL;
plen = len - hdrlen;
last = plen % AES_BLOCK_SIZE;
crypt = os_malloc(hdrlen + 8 + plen + 8 + AES_BLOCK_SIZE);
if (crypt == NULL)
return NULL;
os_memcpy(crypt, frame, hdrlen);
hdr = (struct ieee80211_hdr *) crypt;
hdr->frame_control |= host_to_le16(WLAN_FC_ISWEP);
pos = crypt + hdrlen;
*pos++ = pn[5]; /* PN0 */
*pos++ = pn[4]; /* PN1 */
*pos++ = 0x00; /* Rsvd */
*pos++ = 0x20 | (keyid << 6);
*pos++ = pn[3]; /* PN2 */
*pos++ = pn[2]; /* PN3 */
*pos++ = pn[1]; /* PN4 */
*pos++ = pn[0]; /* PN5 */
aes = aes_encrypt_init(tk, 16);
if (aes == NULL) {
os_free(crypt);
return NULL;
}
os_memset(aad, 0, sizeof(aad));
ccmp_aad_nonce(hdr, crypt + hdrlen, &aad[2], &aad_len, nonce);
WPA_PUT_BE16(aad, aad_len);
wpa_hexdump(MSG_EXCESSIVE, "CCMP AAD", &aad[2], aad_len);
wpa_hexdump(MSG_EXCESSIVE, "CCMP nonce", nonce, 13);
/* Authentication */
/* B_0: Flags | Nonce N | l(m) */
b[0] = 0x40 /* Adata */ | (3 /* M' */ << 3) | 1 /* L' */;
os_memcpy(&b[1], nonce, 13);
WPA_PUT_BE16(&b[14], plen);
wpa_hexdump(MSG_EXCESSIVE, "CCMP B_0", b, AES_BLOCK_SIZE);
aes_encrypt(aes, b, x); /* X_1 = E(K, B_0) */
wpa_hexdump(MSG_EXCESSIVE, "CCMP B_1", aad, AES_BLOCK_SIZE);
xor_aes_block(aad, x);
aes_encrypt(aes, aad, x); /* X_2 = E(K, X_1 XOR B_1) */
wpa_hexdump(MSG_EXCESSIVE, "CCMP B_2", &aad[AES_BLOCK_SIZE],
AES_BLOCK_SIZE);
xor_aes_block(&aad[AES_BLOCK_SIZE], x);
aes_encrypt(aes, &aad[AES_BLOCK_SIZE], x); /* X_3 = E(K, X_2 XOR B_2)
*/
ppos = frame + hdrlen;
for (i = 0; i < plen / AES_BLOCK_SIZE; i++) {
/* X_i+1 = E(K, X_i XOR B_i) */
xor_aes_block(x, ppos);
ppos += AES_BLOCK_SIZE;
aes_encrypt(aes, x, x);
}
if (last) {
/* XOR zero-padded last block */
for (i = 0; i < last; i++)
x[i] ^= *ppos++;
aes_encrypt(aes, x, x);
}
/* Encryption */
/* CCM: M=8 L=2, Adata=1, M' = (M-2)/2 = 3, L' = L-1 = 1 */
/* A_i = Flags | Nonce N | Counter i */
a[0] = 0x01; /* Flags = L' */
os_memcpy(&a[1], nonce, 13);
ppos = crypt + hdrlen + 8;
/* crypt = msg XOR (S_1 | S_2 | ... | S_n) */
mpos = frame + hdrlen;
for (i = 1; i <= plen / AES_BLOCK_SIZE; i++) {
WPA_PUT_BE16(&a[14], i);
/* S_i = E(K, A_i) */
aes_encrypt(aes, a, ppos);
xor_aes_block(ppos, mpos);
ppos += AES_BLOCK_SIZE;
mpos += AES_BLOCK_SIZE;
}
if (last) {
WPA_PUT_BE16(&a[14], i);
aes_encrypt(aes, a, ppos);
/* XOR zero-padded last block */
for (i = 0; i < last; i++)
*ppos++ ^= *mpos++;
}
wpa_hexdump(MSG_EXCESSIVE, "CCMP T", x, 8);
/* U = T XOR S_0; S_0 = E(K, A_0) */
WPA_PUT_BE16(&a[14], 0);
aes_encrypt(aes, a, b);
for (i = 0; i < 8; i++)
ppos[i] = x[i] ^ b[i];
wpa_hexdump(MSG_EXCESSIVE, "CCMP U", ppos, 8);
wpa_hexdump(MSG_EXCESSIVE, "CCMP encrypted", crypt + hdrlen + 8, plen);
aes_encrypt_deinit(aes);
*encrypted_len = hdrlen + 8 + plen + 8;
return crypt;
}