hostap/wlantest/bip.c

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/*
* BIP
* Copyright (c) 2010-2012, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "utils/includes.h"
#include "utils/common.h"
#include "common/ieee802_11_defs.h"
#include "crypto/aes_wrap.h"
#include "wlantest.h"
u8 * bip_protect(const u8 *igtk, u8 *frame, size_t len, u8 *ipn, int keyid,
size_t *prot_len)
{
u8 *prot, *pos, *buf;
u8 mic[16];
u16 fc;
struct ieee80211_hdr *hdr;
size_t plen;
plen = len + 18;
prot = os_malloc(plen);
if (prot == NULL)
return NULL;
os_memcpy(prot, frame, len);
pos = prot + len;
*pos++ = WLAN_EID_MMIE;
*pos++ = 16;
WPA_PUT_LE16(pos, keyid);
pos += 2;
os_memcpy(pos, ipn, 6);
pos += 6;
os_memset(pos, 0, 8); /* MIC */
buf = os_malloc(plen + 20 - 24);
if (buf == NULL) {
os_free(prot);
return NULL;
}
/* BIP AAD: FC(masked) A1 A2 A3 */
hdr = (struct ieee80211_hdr *) frame;
fc = le_to_host16(hdr->frame_control);
fc &= ~(WLAN_FC_RETRY | WLAN_FC_PWRMGT | WLAN_FC_MOREDATA);
WPA_PUT_LE16(buf, fc);
os_memcpy(buf + 2, hdr->addr1, 3 * ETH_ALEN);
os_memcpy(buf + 20, prot + 24, plen - 24);
wpa_hexdump(MSG_MSGDUMP, "BIP: AAD|Body(masked)", buf, plen + 20 - 24);
/* MIC = L(AES-128-CMAC(AAD || Frame Body(masked)), 0, 64) */
if (omac1_aes_128(igtk, buf, plen + 20 - 24, mic) < 0) {
os_free(prot);
os_free(buf);
return NULL;
}
os_free(buf);
os_memcpy(pos, mic, 8);
wpa_hexdump(MSG_DEBUG, "BIP MMIE MIC", pos, 8);
*prot_len = plen;
return prot;
}
u8 * bip_gmac_protect(const u8 *igtk, size_t igtk_len, u8 *frame, size_t len,
u8 *ipn, int keyid, size_t *prot_len)
{
u8 *prot, *pos, *buf;
u16 fc;
struct ieee80211_hdr *hdr;
size_t plen;
u8 nonce[12], *npos;
plen = len + 26;
prot = os_malloc(plen);
if (prot == NULL)
return NULL;
os_memcpy(prot, frame, len);
pos = prot + len;
*pos++ = WLAN_EID_MMIE;
*pos++ = 24;
WPA_PUT_LE16(pos, keyid);
pos += 2;
os_memcpy(pos, ipn, 6);
pos += 6;
os_memset(pos, 0, 16); /* MIC */
buf = os_malloc(plen + 20 - 24);
if (buf == NULL) {
os_free(prot);
return NULL;
}
/* BIP AAD: FC(masked) A1 A2 A3 */
hdr = (struct ieee80211_hdr *) frame;
fc = le_to_host16(hdr->frame_control);
fc &= ~(WLAN_FC_RETRY | WLAN_FC_PWRMGT | WLAN_FC_MOREDATA);
WPA_PUT_LE16(buf, fc);
os_memcpy(buf + 2, hdr->addr1, 3 * ETH_ALEN);
os_memcpy(buf + 20, prot + 24, plen - 24);
wpa_hexdump(MSG_MSGDUMP, "BIP-GMAC: AAD|Body(masked)",
buf, plen + 20 - 24);
/* Nonce: A2 | IPN */
os_memcpy(nonce, hdr->addr2, ETH_ALEN);
npos = nonce + ETH_ALEN;
*npos++ = ipn[5];
*npos++ = ipn[4];
*npos++ = ipn[3];
*npos++ = ipn[2];
*npos++ = ipn[1];
*npos++ = ipn[0];
wpa_hexdump(MSG_EXCESSIVE, "BIP-GMAC: Nonce", nonce, sizeof(nonce));
/* MIC = AES-GMAC(AAD || Frame Body(masked)) */
if (aes_gmac(igtk, igtk_len, nonce, sizeof(nonce),
buf, plen + 20 - 24, pos) < 0) {
os_free(prot);
os_free(buf);
return NULL;
}
os_free(buf);
wpa_hexdump(MSG_DEBUG, "BIP-GMAC MMIE MIC", pos, 16);
*prot_len = plen;
return prot;
}