/* Compute Message Integrity Code (MIC) over EAPOL message */
bool
BCMROMFN(wpa_make_mic)(eapol_header_t *eapol, uint key_desc, uint8 *mic_key, uchar *mic)
{
int mic_length;
/* length of eapol pkt from the version field on */
mic_length = 4 + ntoh16_ua((uint8 *)&eapol->length);
/* Create the MIC for the pkt */
switch (key_desc) {
case WPA_KEY_DESC_V1:
hmac_md5(&eapol->version, mic_length, mic_key,
EAPOL_WPA_KEY_MIC_LEN, mic);
break;
case WPA_KEY_DESC_V2:
hmac_sha1(&eapol->version, mic_length, mic_key,
EAPOL_WPA_KEY_MIC_LEN, mic);
break;
case WPA_KEY_DESC_V3:
aes_cmac_calc(&eapol->version, mic_length, mic_key,
EAPOL_WPA_KEY_MIC_LEN, mic);
break;
default:
return FALSE;
}
return TRUE;
}
/* calculates BIP; mic must be at least AES_BLOCK_SZ */
static void bip_calc(const struct dot11_header *hdr,
const uint8 *data, int data_len, const uint8 *key, uint8 * mic)
{
uint len;
uint8* micdata;
uint16 fc;
memset(mic, 0 , AES_BLOCK_SZ);
micdata = malloc(2 + 3 * ETHER_ADDR_LEN + data_len);
if (!micdata)
return;
fc = htol16(ltoh16(hdr->fc) & ~(FC_RETRY | FC_PM | FC_MOREDATA));
len = 0;
memcpy((char *)&micdata[len], (uint8 *)&fc, 2);
len += 2;
memcpy(&micdata[len], (uint8 *)&hdr->a1, ETHER_ADDR_LEN);
len += ETHER_ADDR_LEN;
memcpy(&micdata[len], (uint8 *)&hdr->a2, ETHER_ADDR_LEN);
len += ETHER_ADDR_LEN;
memcpy(&micdata[len], (uint8 *)&hdr->a3, ETHER_ADDR_LEN);
len += ETHER_ADDR_LEN;
memcpy(&micdata[len], data, data_len);
len += data_len;
aes_cmac_calc(micdata, len, key, BIP_KEY_SIZE, mic);
free(micdata);
}
