static int wpa_ft_install_ptk(struct wpa_sm *sm, const u8 *bssid)
{
int keylen;
enum wpa_alg alg;
u8 null_rsc[6] = { 0, 0, 0, 0, 0, 0 };
wpa_printf(MSG_DEBUG, "FT: Installing PTK to the driver.");
if (!wpa_cipher_valid_pairwise(sm->pairwise_cipher)) {
wpa_printf(MSG_WARNING, "FT: Unsupported pairwise cipher %d",
sm->pairwise_cipher);
return -1;
}
alg = wpa_cipher_to_alg(sm->pairwise_cipher);
keylen = wpa_cipher_key_len(sm->pairwise_cipher);
if (wpa_sm_set_key(sm, alg, bssid, 0, 1, null_rsc,
sizeof(null_rsc), (u8 *) sm->ptk.tk, keylen) < 0) {
wpa_printf(MSG_WARNING, "FT: Failed to set PTK to the driver");
return -1;
}
return 0;
}
void wpa_ft_install_ptk(struct wpa_state_machine *sm)
{
enum wpa_alg alg;
int klen;
/* MLME-SETKEYS.request(PTK) */
alg = wpa_cipher_to_alg(sm->pairwise);
klen = wpa_cipher_key_len(sm->pairwise);
if (!wpa_cipher_valid_pairwise(sm->pairwise)) {
wpa_printf(MSG_DEBUG, "FT: Unknown pairwise alg 0x%x - skip "
"PTK configuration", sm->pairwise);
return;
}
/* FIX: add STA entry to kernel/driver here? The set_key will fail
* most likely without this.. At the moment, STA entry is added only
* after association has been completed. This function will be called
* again after association to get the PTK configured, but that could be
* optimized by adding the STA entry earlier.
*/
if (wpa_auth_set_key(sm->wpa_auth, 0, alg, sm->addr, 0,
sm->PTK.tk1, klen))
return;
/* FIX: MLME-SetProtection.Request(TA, Tx_Rx) */
sm->pairwise_set = TRUE;
}
/**
* wpa_pmk_to_ptk - Calculate PTK from PMK, addresses, and nonces
* @pmk: Pairwise master key
* @pmk_len: Length of PMK
* @label: Label to use in derivation
* @addr1: AA or SA
* @addr2: SA or AA
* @nonce1: ANonce or SNonce
* @nonce2: SNonce or ANonce
* @ptk: Buffer for pairwise transient key
* @akmp: Negotiated AKM
* @cipher: Negotiated pairwise cipher
* Returns: 0 on success, -1 on failure
*
* IEEE Std 802.11i-2004 - 8.5.1.2 Pairwise key hierarchy
* PTK = PRF-X(PMK, "Pairwise key expansion",
* Min(AA, SA) || Max(AA, SA) ||
* Min(ANonce, SNonce) || Max(ANonce, SNonce))
*
* STK = PRF-X(SMK, "Peer key expansion",
* Min(MAC_I, MAC_P) || Max(MAC_I, MAC_P) ||
* Min(INonce, PNonce) || Max(INonce, PNonce))
*/
int wpa_pmk_to_ptk(const u8 *pmk, size_t pmk_len, const char *label,
const u8 *addr1, const u8 *addr2,
const u8 *nonce1, const u8 *nonce2,
struct wpa_ptk *ptk, int akmp, int cipher)
{
u8 data[2 * ETH_ALEN + 2 * WPA_NONCE_LEN];
u8 tmp[WPA_KCK_MAX_LEN + WPA_KEK_MAX_LEN + WPA_TK_MAX_LEN];
size_t ptk_len;
if (os_memcmp(addr1, addr2, ETH_ALEN) < 0) {
os_memcpy(data, addr1, ETH_ALEN);
os_memcpy(data + ETH_ALEN, addr2, ETH_ALEN);
} else {
os_memcpy(data, addr2, ETH_ALEN);
os_memcpy(data + ETH_ALEN, addr1, ETH_ALEN);
}
if (os_memcmp(nonce1, nonce2, WPA_NONCE_LEN) < 0) {
os_memcpy(data + 2 * ETH_ALEN, nonce1, WPA_NONCE_LEN);
os_memcpy(data + 2 * ETH_ALEN + WPA_NONCE_LEN, nonce2,
WPA_NONCE_LEN);
} else {
os_memcpy(data + 2 * ETH_ALEN, nonce2, WPA_NONCE_LEN);
os_memcpy(data + 2 * ETH_ALEN + WPA_NONCE_LEN, nonce1,
WPA_NONCE_LEN);
}
ptk->kck_len = wpa_kck_len(akmp);
ptk->kek_len = wpa_kek_len(akmp);
ptk->tk_len = wpa_cipher_key_len(cipher);
ptk_len = ptk->kck_len + ptk->kek_len + ptk->tk_len;
#ifdef CONFIG_IEEE80211W
if (wpa_key_mgmt_sha256(akmp))
sha256_prf(pmk, pmk_len, label, data, sizeof(data),
tmp, ptk_len);
else
#endif /* CONFIG_IEEE80211W */
sha1_prf(pmk, pmk_len, label, data, sizeof(data), tmp, ptk_len);
wpa_printf(MSG_DEBUG, "WPA: PTK derivation - A1=" MACSTR " A2=" MACSTR,
MAC2STR(addr1), MAC2STR(addr2));
wpa_hexdump(MSG_DEBUG, "WPA: Nonce1", nonce1, WPA_NONCE_LEN);
wpa_hexdump(MSG_DEBUG, "WPA: Nonce2", nonce2, WPA_NONCE_LEN);
wpa_hexdump_key(MSG_DEBUG, "WPA: PMK", pmk, pmk_len);
wpa_hexdump_key(MSG_DEBUG, "WPA: PTK", tmp, ptk_len);
os_memcpy(ptk->kck, tmp, ptk->kck_len);
wpa_hexdump_key(MSG_DEBUG, "WPA: KCK", ptk->kck, ptk->kck_len);
os_memcpy(ptk->kek, tmp + ptk->kck_len, ptk->kek_len);
wpa_hexdump_key(MSG_DEBUG, "WPA: KEK", ptk->kek, ptk->kek_len);
os_memcpy(ptk->tk, tmp + ptk->kck_len + ptk->kek_len, ptk->tk_len);
wpa_hexdump_key(MSG_DEBUG, "WPA: TK", ptk->tk, ptk->tk_len);
os_memset(tmp, 0, sizeof(tmp));
return 0;
}
static int wpa_ft_process_gtk_subelem(struct wpa_sm *sm, const u8 *gtk_elem,
size_t gtk_elem_len)
{
u8 gtk[32];
int keyidx;
enum wpa_alg alg;
size_t gtk_len, keylen, rsc_len;
if (gtk_elem == NULL) {
wpa_printf(MSG_DEBUG, "FT: No GTK included in FTIE");
return 0;
}
wpa_hexdump_key(MSG_DEBUG, "FT: Received GTK in Reassoc Resp",
gtk_elem, gtk_elem_len);
if (gtk_elem_len < 11 + 24 || (gtk_elem_len - 11) % 8 ||
gtk_elem_len - 19 > sizeof(gtk)) {
wpa_printf(MSG_DEBUG, "FT: Invalid GTK sub-elem "
"length %lu", (unsigned long) gtk_elem_len);
return -1;
}
gtk_len = gtk_elem_len - 19;
if (aes_unwrap(sm->ptk.kek, sm->ptk.kek_len, gtk_len / 8, gtk_elem + 11,
gtk)) {
wpa_printf(MSG_WARNING, "FT: AES unwrap failed - could not "
"decrypt GTK");
return -1;
}
keylen = wpa_cipher_key_len(sm->group_cipher);
rsc_len = wpa_cipher_rsc_len(sm->group_cipher);
alg = wpa_cipher_to_alg(sm->group_cipher);
if (alg == WPA_ALG_NONE) {
wpa_printf(MSG_WARNING, "WPA: Unsupported Group Cipher %d",
sm->group_cipher);
return -1;
}
if (gtk_len < keylen) {
wpa_printf(MSG_DEBUG, "FT: Too short GTK in FTIE");
return -1;
}
/* Key Info[2] | Key Length[1] | RSC[8] | Key[5..32]. */
keyidx = WPA_GET_LE16(gtk_elem) & 0x03;
if (gtk_elem[2] != keylen) {
wpa_printf(MSG_DEBUG, "FT: GTK length mismatch: received %d "
"negotiated %lu",
gtk_elem[2], (unsigned long) keylen);
return -1;
}
wpa_hexdump_key(MSG_DEBUG, "FT: GTK from Reassoc Resp", gtk, keylen);
if (sm->group_cipher == WPA_CIPHER_TKIP) {
/* Swap Tx/Rx keys for Michael MIC */
u8 tmp[8];
os_memcpy(tmp, gtk + 16, 8);
os_memcpy(gtk + 16, gtk + 24, 8);
os_memcpy(gtk + 24, tmp, 8);
}
if (wpa_sm_set_key(sm, alg, broadcast_ether_addr, keyidx, 0,
gtk_elem + 3, rsc_len, gtk, keylen) < 0) {
wpa_printf(MSG_WARNING, "WPA: Failed to set GTK to the "
"driver.");
return -1;
}
return 0;
}
/**
* wpa_pmk_r1_to_ptk - Derive PTK and PTKName from PMK-R1
*
* IEEE Std 802.11r-2008 - 8.5.1.5.5
*/
int wpa_pmk_r1_to_ptk(const u8 *pmk_r1, const u8 *snonce, const u8 *anonce,
const u8 *sta_addr, const u8 *bssid,
const u8 *pmk_r1_name,
struct wpa_ptk *ptk, u8 *ptk_name, int akmp, int cipher)
{
u8 buf[2 * WPA_NONCE_LEN + 2 * ETH_ALEN];
u8 *pos, hash[32];
const u8 *addr[6];
size_t len[6];
u8 tmp[WPA_KCK_MAX_LEN + WPA_KEK_MAX_LEN + WPA_TK_MAX_LEN];
size_t ptk_len;
/*
* PTK = KDF-PTKLen(PMK-R1, "FT-PTK", SNonce || ANonce ||
* BSSID || STA-ADDR)
*/
pos = buf;
os_memcpy(pos, snonce, WPA_NONCE_LEN);
pos += WPA_NONCE_LEN;
os_memcpy(pos, anonce, WPA_NONCE_LEN);
pos += WPA_NONCE_LEN;
os_memcpy(pos, bssid, ETH_ALEN);
pos += ETH_ALEN;
os_memcpy(pos, sta_addr, ETH_ALEN);
pos += ETH_ALEN;
ptk->kck_len = wpa_kck_len(akmp);
ptk->kek_len = wpa_kek_len(akmp);
ptk->tk_len = wpa_cipher_key_len(cipher);
ptk_len = ptk->kck_len + ptk->kek_len + ptk->tk_len;
sha256_prf(pmk_r1, PMK_LEN, "FT-PTK", buf, pos - buf, tmp, ptk_len);
/*
* PTKName = Truncate-128(SHA-256(PMKR1Name || "FT-PTKN" || SNonce ||
* ANonce || BSSID || STA-ADDR))
*/
addr[0] = pmk_r1_name;
len[0] = WPA_PMK_NAME_LEN;
addr[1] = (const u8 *) "FT-PTKN";
len[1] = 7;
addr[2] = snonce;
len[2] = WPA_NONCE_LEN;
addr[3] = anonce;
len[3] = WPA_NONCE_LEN;
addr[4] = bssid;
len[4] = ETH_ALEN;
addr[5] = sta_addr;
len[5] = ETH_ALEN;
sha256_vector(6, addr, len, hash);
os_memcpy(ptk_name, hash, WPA_PMK_NAME_LEN);
os_memcpy(ptk->kck, tmp, ptk->kck_len);
os_memcpy(ptk->kek, tmp + ptk->kck_len, ptk->kek_len);
os_memcpy(ptk->tk, tmp + ptk->kck_len + ptk->kek_len, ptk->tk_len);
wpa_hexdump_key(MSG_DEBUG, "FT: KCK", ptk->kck, ptk->kck_len);
wpa_hexdump_key(MSG_DEBUG, "FT: KEK", ptk->kek, ptk->kek_len);
wpa_hexdump_key(MSG_DEBUG, "FT: TK", ptk->tk, ptk->tk_len);
wpa_hexdump(MSG_DEBUG, "FT: PTKName", ptk_name, WPA_PMK_NAME_LEN);
os_memset(tmp, 0, sizeof(tmp));
return 0;
}
