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Fix Suite B 192-bit AKM to use proper PMK length

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In addition to the PTK length increasing, the length of the PMK was
increased (from 256 to 384 bits) for the 00-0f-ac:12 AKM. This part was
missing from the initial implementation and a fixed length (256-bit) PMK
was used for all AKMs.

Fix this by adding more complete support for variable length PMK and use
384 bits from MSK instead of 256 bits when using this AKM. This is not
backwards compatible with the earlier implementations.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
This commit is contained in:
Jouni Malinen 2015-10-14 01:18:11 +03:00 • committed by Jouni Malinen
parent ae7d9fbd3d
commit 207976f053
11 changed files with 73 additions and 27 deletions
Download patch file Download diff file Expand all files Collapse all files

60
src/ap/wpa_auth.c
View file

@ -44,7 +44,8 @@ static int wpa_gtk_update(struct wpa_authenticator *wpa_auth,
static int wpa_group_config_group_keys(struct wpa_authenticator *wpa_auth,
struct wpa_group *group);
static int wpa_derive_ptk(struct wpa_state_machine *sm, const u8 *snonce,
const u8 *pmk, struct wpa_ptk *ptk);
const u8 *pmk, unsigned int pmk_len,
struct wpa_ptk *ptk);
static void wpa_group_free(struct wpa_authenticator *wpa_auth,
struct wpa_group *group);
static void wpa_group_get(struct wpa_authenticator *wpa_auth,
@ -827,6 +828,7 @@ static int wpa_try_alt_snonce(struct wpa_state_machine *sm, u8 *data,
struct wpa_ptk PTK;
int ok = 0;
const u8 *pmk = NULL;
unsigned int pmk_len;
for (;;) {
if (wpa_key_mgmt_wpa_psk(sm->wpa_key_mgmt)) {
@ -834,10 +836,13 @@ static int wpa_try_alt_snonce(struct wpa_state_machine *sm, u8 *data,
sm->p2p_dev_addr, pmk);
if (pmk == NULL)
break;
} else
pmk_len = PMK_LEN;
} else {
pmk = sm->PMK;
pmk_len = sm->pmk_len;
}
wpa_derive_ptk(sm, sm->alt_SNonce, pmk, &PTK);
wpa_derive_ptk(sm, sm->alt_SNonce, pmk, pmk_len, &PTK);
if (wpa_verify_key_mic(sm->wpa_key_mgmt, &PTK, data, data_len)
== 0) {
@ -1904,11 +1909,27 @@ SM_STATE(WPA_PTK, INITPMK)
#endif /* CONFIG_IEEE80211R */
if (sm->pmksa) {
wpa_printf(MSG_DEBUG, "WPA: PMK from PMKSA cache");
os_memcpy(sm->PMK, sm->pmksa->pmk, PMK_LEN);
os_memcpy(sm->PMK, sm->pmksa->pmk, sm->pmksa->pmk_len);
sm->pmk_len = sm->pmksa->pmk_len;
} else if (wpa_auth_get_msk(sm->wpa_auth, sm->addr, msk, &len) == 0) {
unsigned int pmk_len;
if (sm->wpa_key_mgmt & WPA_KEY_MGMT_IEEE8021X_SUITE_B_192)
pmk_len = PMK_LEN_SUITE_B_192;
else
pmk_len = PMK_LEN;
wpa_printf(MSG_DEBUG, "WPA: PMK from EAPOL state machine "
"(len=%lu)", (unsigned long) len);
os_memcpy(sm->PMK, msk, PMK_LEN);
"(MSK len=%lu PMK len=%u)", (unsigned long) len,
pmk_len);
if (len < pmk_len) {
wpa_printf(MSG_DEBUG,
"WPA: MSK not long enough (%u) to create PMK (%u)",
(unsigned int) len, (unsigned int) pmk_len);
sm->Disconnect = TRUE;
return;
}
os_memcpy(sm->PMK, msk, pmk_len);
sm->pmk_len = pmk_len;
#ifdef CONFIG_IEEE80211R
if (len >= 2 * PMK_LEN) {
os_memcpy(sm->xxkey, msk + PMK_LEN, PMK_LEN);
@ -1943,6 +1964,7 @@ SM_STATE(WPA_PTK, INITPSK)
psk = wpa_auth_get_psk(sm->wpa_auth, sm->addr, sm->p2p_dev_addr, NULL);
if (psk) {
os_memcpy(sm->PMK, psk, PMK_LEN);
sm->pmk_len = PMK_LEN;
#ifdef CONFIG_IEEE80211R
os_memcpy(sm->xxkey, psk, PMK_LEN);
sm->xxkey_len = PMK_LEN;
@ -1994,7 +2016,7 @@ SM_STATE(WPA_PTK, PTKSTART)
* Calculate PMKID since no PMKSA cache entry was
* available with pre-calculated PMKID.
*/
rsn_pmkid(sm->PMK, PMK_LEN, sm->wpa_auth->addr,
rsn_pmkid(sm->PMK, sm->pmk_len, sm->wpa_auth->addr,
sm->addr, &pmkid[2 + RSN_SELECTOR_LEN],
wpa_key_mgmt_sha256(sm->wpa_key_mgmt));
}
@ -2006,14 +2028,15 @@ SM_STATE(WPA_PTK, PTKSTART)
static int wpa_derive_ptk(struct wpa_state_machine *sm, const u8 *snonce,
const u8 *pmk, struct wpa_ptk *ptk)
const u8 *pmk, unsigned int pmk_len,
struct wpa_ptk *ptk)
{
#ifdef CONFIG_IEEE80211R
if (wpa_key_mgmt_ft(sm->wpa_key_mgmt))
return wpa_auth_derive_ptk_ft(sm, pmk, ptk);
#endif /* CONFIG_IEEE80211R */
return wpa_pmk_to_ptk(pmk, PMK_LEN, "Pairwise key expansion",
return wpa_pmk_to_ptk(pmk, pmk_len, "Pairwise key expansion",
sm->wpa_auth->addr, sm->addr, sm->ANonce, snonce,
ptk, sm->wpa_key_mgmt, sm->pairwise);
}
@ -2024,6 +2047,7 @@ SM_STATE(WPA_PTK, PTKCALCNEGOTIATING)
struct wpa_ptk PTK;
int ok = 0, psk_found = 0;
const u8 *pmk = NULL;
unsigned int pmk_len;
SM_ENTRY_MA(WPA_PTK, PTKCALCNEGOTIATING, wpa_ptk);
sm->EAPOLKeyReceived = FALSE;
@ -2039,10 +2063,13 @@ SM_STATE(WPA_PTK, PTKCALCNEGOTIATING)
if (pmk == NULL)
break;
psk_found = 1;
} else
pmk_len = PMK_LEN;
} else {
pmk = sm->PMK;
pmk_len = sm->pmk_len;
}
wpa_derive_ptk(sm, sm->SNonce, pmk, &PTK);
wpa_derive_ptk(sm, sm->SNonce, pmk, pmk_len, &PTK);
if (wpa_verify_key_mic(sm->wpa_key_mgmt, &PTK,
sm->last_rx_eapol_key,
@ -2092,6 +2119,7 @@ SM_STATE(WPA_PTK, PTKCALCNEGOTIATING)
* state machine data based on whatever PSK was selected here.
*/
os_memcpy(sm->PMK, pmk, PMK_LEN);
sm->pmk_len = PMK_LEN;
}
sm->MICVerified = TRUE;
@ -3243,13 +3271,21 @@ const u8 * wpa_auth_get_wpa_ie(struct wpa_authenticator *wpa_auth, size_t *len)
int wpa_auth_pmksa_add(struct wpa_state_machine *sm, const u8 *pmk,
unsigned int pmk_len,
int session_timeout, struct eapol_state_machine *eapol)
{
if (sm == NULL || sm->wpa != WPA_VERSION_WPA2 ||
sm->wpa_auth->conf.disable_pmksa_caching)
return -1;
if (pmksa_cache_auth_add(sm->wpa_auth->pmksa, pmk, PMK_LEN,
if (sm->wpa_key_mgmt & WPA_KEY_MGMT_IEEE8021X_SUITE_B_192) {
if (pmk_len > PMK_LEN_SUITE_B_192)
pmk_len = PMK_LEN_SUITE_B_192;
} else if (pmk_len > PMK_LEN) {
pmk_len = PMK_LEN;
}
if (pmksa_cache_auth_add(sm->wpa_auth->pmksa, pmk, pmk_len,
sm->PTK.kck, sm->PTK.kck_len,
sm->wpa_auth->addr, sm->addr, session_timeout,
eapol, sm->wpa_key_mgmt))