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FILS: Add FILS SK auth PFS support in STA mode

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This adds an option to configure wpa_supplicant to use the perfect
forward secrecy option in FILS shared key authentication. A new build
option CONFIG_FILS_SK_PFS=y can be used to include this functionality. A
new runtime network profile parameter fils_dh_group is used to enable
this by specifying which DH group to use. For example, fils_dh_group=19
would use FILS SK PFS with a 256-bit random ECP group.

Signed-off-by: Jouni Malinen <j@w1.fi>
This commit is contained in:
Jouni Malinen 2017-03-12 22:45:35 +02:00
parent 1764559eef
commit 76e20f4fa7
12 changed files with 170 additions and 28 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

123
src/rsn_supp/wpa.c
View file

@ -2461,6 +2461,9 @@ void wpa_sm_deinit(struct wpa_sm *sm)
#ifdef CONFIG_TESTING_OPTIONS
wpabuf_free(sm->test_assoc_ie);
#endif /* CONFIG_TESTING_OPTIONS */
#ifdef CONFIG_FILS
crypto_ecdh_deinit(sm->fils_ecdh);
#endif /* CONFIG_FILS */
#ifdef CONFIG_OWE
crypto_ecdh_deinit(sm->owe_ecdh);
#endif /* CONFIG_OWE */
@ -3265,10 +3268,11 @@ void wpa_sm_set_test_assoc_ie(struct wpa_sm *sm, struct wpabuf *buf)
#ifdef CONFIG_FILS
struct wpabuf * fils_build_auth(struct wpa_sm *sm)
struct wpabuf * fils_build_auth(struct wpa_sm *sm, int dh_group)
{
struct wpabuf *buf = NULL;
struct wpabuf *erp_msg;
struct wpabuf *pub = NULL;
erp_msg = eapol_sm_build_erp_reauth_start(sm->eapol);
if (!erp_msg && !sm->cur_pmksa) {
@ -3296,7 +3300,28 @@ struct wpabuf * fils_build_auth(struct wpa_sm *sm)
wpa_hexdump(MSG_DEBUG, "FILS: Generated FILS Session",
sm->fils_session, FILS_SESSION_LEN);
buf = wpabuf_alloc(1000 + sm->assoc_wpa_ie_len);
#ifdef CONFIG_FILS_SK_PFS
sm->fils_dh_group = dh_group;
if (dh_group) {
crypto_ecdh_deinit(sm->fils_ecdh);
sm->fils_ecdh = crypto_ecdh_init(dh_group);
if (!sm->fils_ecdh) {
wpa_printf(MSG_INFO,
"FILS: Could not initialize ECDH with group %d",
dh_group);
goto fail;
}
pub = crypto_ecdh_get_pubkey(sm->fils_ecdh, 1);
if (!pub)
goto fail;
wpa_hexdump_buf(MSG_DEBUG, "FILS: Element (DH public key)",
pub);
sm->fils_dh_elem_len = wpabuf_len(pub);
}
#endif /* CONFIG_FILS_SK_PFS */
buf = wpabuf_alloc(1000 + sm->assoc_wpa_ie_len +
(pub ? wpabuf_len(pub) : 0));
if (!buf)
goto fail;
@ -3308,8 +3333,15 @@ struct wpabuf * fils_build_auth(struct wpa_sm *sm)
/* Status Code */
wpabuf_put_le16(buf, WLAN_STATUS_SUCCESS);
/* TODO: Finite Cyclic Group when using PK or PFS */
/* TODO: Element when using PK or PFS */
/* TODO: FILS PK */
#ifdef CONFIG_FILS_SK_PFS
if (dh_group) {
/* Finite Cyclic Group */
wpabuf_put_le16(buf, dh_group);
/* Element */
wpabuf_put_buf(buf, pub);
}
#endif /* CONFIG_FILS_SK_PFS */
/* RSNE */
wpa_hexdump(MSG_DEBUG, "FILS: RSNE in FILS Authentication frame",
@ -3354,6 +3386,7 @@ struct wpabuf * fils_build_auth(struct wpa_sm *sm)
fail:
wpabuf_free(erp_msg);
wpabuf_free(pub);
return buf;
}
@ -3368,6 +3401,7 @@ int fils_process_auth(struct wpa_sm *sm, const u8 *bssid, const u8 *data,
u8 ick[FILS_ICK_MAX_LEN];
size_t ick_len;
int res;
struct wpabuf *dh_ss = NULL;
os_memcpy(sm->bssid, bssid, ETH_ALEN);
@ -3376,13 +3410,53 @@ int fils_process_auth(struct wpa_sm *sm, const u8 *bssid, const u8 *data,
pos = data;
end = data + len;
/* TODO: Finite Cyclic Group when using PK or PFS */
/* TODO: Element when using PK or PFS */
/* TODO: FILS PK */
#ifdef CONFIG_FILS_SK_PFS
if (sm->fils_dh_group) {
u16 group;
/* Using FILS PFS */
/* Finite Cyclic Group */
if (end - pos < 2) {
wpa_printf(MSG_DEBUG,
"FILS: No room for Finite Cyclic Group");
goto fail;
}
group = WPA_GET_LE16(pos);
pos += 2;
if (group != sm->fils_dh_group) {
wpa_printf(MSG_DEBUG,
"FILS: Unexpected change in Finite Cyclic Group: %u (expected %u)",
group, sm->fils_dh_group);
goto fail;
}
/* Element */
if ((size_t) (end - pos) < sm->fils_dh_elem_len) {
wpa_printf(MSG_DEBUG, "FILS: No room for Element");
goto fail;
}
if (!sm->fils_ecdh) {
wpa_printf(MSG_DEBUG, "FILS: No ECDH state available");
goto fail;
}
dh_ss = crypto_ecdh_set_peerkey(sm->fils_ecdh, 1, pos,
sm->fils_dh_elem_len);
if (!dh_ss) {
wpa_printf(MSG_DEBUG, "FILS: ECDH operation failed");
goto fail;
}
wpa_hexdump_buf_key(MSG_DEBUG, "FILS: DH_SS", dh_ss);
pos += sm->fils_dh_elem_len;
}
#endif /* CONFIG_FILS_SK_PFS */
wpa_hexdump(MSG_DEBUG, "FILS: Remaining IEs", pos, end - pos);
if (ieee802_11_parse_elems(pos, end - pos, &elems, 1) == ParseFailed) {
wpa_printf(MSG_DEBUG, "FILS: Could not parse elements");
return -1;
goto fail;
}
/* RSNE */
@ -3392,12 +3466,12 @@ int fils_process_auth(struct wpa_sm *sm, const u8 *bssid, const u8 *data,
wpa_parse_wpa_ie_rsn(elems.rsn_ie - 2, elems.rsn_ie_len + 2,
&rsn) < 0) {
wpa_printf(MSG_DEBUG, "FILS: No RSN element");
return -1;
goto fail;
}
if (!elems.fils_nonce) {
wpa_printf(MSG_DEBUG, "FILS: No FILS Nonce field");
return -1;
goto fail;
}
os_memcpy(sm->fils_anonce, elems.fils_nonce, FILS_NONCE_LEN);
wpa_hexdump(MSG_DEBUG, "FILS: ANonce", sm->fils_anonce, FILS_NONCE_LEN);
@ -3412,7 +3486,7 @@ int fils_process_auth(struct wpa_sm *sm, const u8 *bssid, const u8 *data,
if (rsn.num_pmkid != 1) {
wpa_printf(MSG_DEBUG, "FILS: Invalid PMKID selection");
return -1;
goto fail;
}
wpa_hexdump(MSG_DEBUG, "FILS: PMKID", rsn.pmkid, PMKID_LEN);
if (os_memcmp(sm->cur_pmksa->pmkid, rsn.pmkid, PMKID_LEN) != 0)
@ -3420,7 +3494,7 @@ int fils_process_auth(struct wpa_sm *sm, const u8 *bssid, const u8 *data,
wpa_printf(MSG_DEBUG, "FILS: PMKID mismatch");
wpa_hexdump(MSG_DEBUG, "FILS: Expected PMKID",
sm->cur_pmksa->pmkid, PMKID_LEN);
return -1;
goto fail;
}
wpa_printf(MSG_DEBUG,
"FILS: Matching PMKID - continue using PMKSA caching");
@ -3435,7 +3509,7 @@ int fils_process_auth(struct wpa_sm *sm, const u8 *bssid, const u8 *data,
/* FILS Session */
if (!elems.fils_session) {
wpa_printf(MSG_DEBUG, "FILS: No FILS Session element");
return -1;
goto fail;
}
wpa_hexdump(MSG_DEBUG, "FILS: FILS Session", elems.fils_session,
FILS_SESSION_LEN);
@ -3444,7 +3518,7 @@ int fils_process_auth(struct wpa_sm *sm, const u8 *bssid, const u8 *data,
wpa_printf(MSG_DEBUG, "FILS: Session mismatch");
wpa_hexdump(MSG_DEBUG, "FILS: Expected FILS Session",
sm->fils_session, FILS_SESSION_LEN);
return -1;
goto fail;
}
/* FILS Wrapped Data */
@ -3458,7 +3532,7 @@ int fils_process_auth(struct wpa_sm *sm, const u8 *bssid, const u8 *data,
eapol_sm_process_erp_finish(sm->eapol, elems.fils_wrapped_data,
elems.fils_wrapped_data_len);
if (eapol_sm_failed(sm->eapol))
return -1;
goto fail;
rmsk_len = ERP_MAX_KEY_LEN;
res = eapol_sm_get_key(sm->eapol, rmsk, rmsk_len);
@ -3467,18 +3541,22 @@ int fils_process_auth(struct wpa_sm *sm, const u8 *bssid, const u8 *data,
res = eapol_sm_get_key(sm->eapol, rmsk, rmsk_len);
}
if (res)
return -1;
goto fail;
res = fils_rmsk_to_pmk(sm->key_mgmt, rmsk, rmsk_len,
sm->fils_nonce, sm->fils_anonce, NULL, 0,
sm->fils_nonce, sm->fils_anonce,
dh_ss ? wpabuf_head(dh_ss) : NULL,
dh_ss ? wpabuf_len(dh_ss) : 0,
sm->pmk, &sm->pmk_len);
os_memset(rmsk, 0, sizeof(rmsk));
wpabuf_clear_free(dh_ss);
dh_ss = NULL;
if (res)
return -1;
goto fail;
if (!sm->fils_erp_pmkid_set) {
wpa_printf(MSG_DEBUG, "FILS: PMKID not available");
return -1;
goto fail;
}
wpa_hexdump(MSG_DEBUG, "FILS: PMKID", sm->fils_erp_pmkid,
PMKID_LEN);
@ -3493,7 +3571,7 @@ int fils_process_auth(struct wpa_sm *sm, const u8 *bssid, const u8 *data,
if (!sm->cur_pmksa) {
wpa_printf(MSG_DEBUG,
"FILS: No remaining options to continue FILS authentication");
return -1;
goto fail;
}
if (fils_pmk_to_ptk(sm->pmk, sm->pmk_len, sm->own_addr, sm->bssid,
@ -3501,7 +3579,7 @@ int fils_process_auth(struct wpa_sm *sm, const u8 *bssid, const u8 *data,
ick, &ick_len, sm->key_mgmt, sm->pairwise_cipher) <
0) {
wpa_printf(MSG_DEBUG, "FILS: Failed to derive PTK");
return -1;
goto fail;
}
sm->ptk_set = 1;
sm->tptk_set = 0;
@ -3509,12 +3587,15 @@ int fils_process_auth(struct wpa_sm *sm, const u8 *bssid, const u8 *data,
res = fils_key_auth_sk(ick, ick_len, sm->fils_nonce,
sm->fils_anonce, sm->own_addr, sm->bssid,
NULL, 0, NULL, 0, /* TODO: SK+PFS */
NULL, 0, NULL, 0, /* TODO: PK */
sm->key_mgmt, sm->fils_key_auth_sta,
sm->fils_key_auth_ap,
&sm->fils_key_auth_len);
os_memset(ick, 0, sizeof(ick));
return res;
fail:
wpabuf_clear_free(dh_ss);
return -1;
}

2
src/rsn_supp/wpa.h
View file

@ -435,7 +435,7 @@ extern unsigned int tdls_testing;
int wpa_wnmsleep_install_key(struct wpa_sm *sm, u8 subelem_id, u8 *buf);
void wpa_sm_set_test_assoc_ie(struct wpa_sm *sm, struct wpabuf *buf);
struct wpabuf * fils_build_auth(struct wpa_sm *sm);
struct wpabuf * fils_build_auth(struct wpa_sm *sm, int dh_group);
int fils_process_auth(struct wpa_sm *sm, const u8 *bssid, const u8 *data,
size_t len);
struct wpabuf * fils_build_assoc_req(struct wpa_sm *sm, const u8 **kek,

3
src/rsn_supp/wpa_i.h
View file

@ -151,6 +151,9 @@ struct wpa_sm {
unsigned int fils_cache_id_set:1;
u8 fils_erp_pmkid[PMKID_LEN];
u8 fils_cache_id[FILS_CACHE_ID_LEN];
struct crypto_ecdh *fils_ecdh;
int fils_dh_group;
size_t fils_dh_elem_len;
#endif /* CONFIG_FILS */
#ifdef CONFIG_OWE

4
wpa_supplicant/Android.mk
View file

@ -253,6 +253,10 @@ ifdef CONFIG_FILS
L_CFLAGS += -DCONFIG_FILS
NEED_SHA384=y
NEED_AES_SIV=y
ifdef CONFIG_FILS_SK_PFS
L_CFLAGS += -DCONFIG_FILS_SK_PFS
NEED_ECC=y
endif
endif
ifdef CONFIG_WNM

4
wpa_supplicant/Makefile
View file

@ -286,6 +286,10 @@ ifdef CONFIG_FILS
CFLAGS += -DCONFIG_FILS
NEED_SHA384=y
NEED_AES_SIV=y
ifdef CONFIG_FILS_SK_PFS
CFLAGS += -DCONFIG_FILS_SK_PFS
NEED_ECC=y
endif
endif
ifdef CONFIG_WNM

1
wpa_supplicant/config.c
View file

@ -2147,6 +2147,7 @@ static const struct parse_data ssid_fields[] = {
{ INT_RANGE(mac_addr, 0, 2) },
{ INT_RANGE(pbss, 0, 2) },
{ INT_RANGE(wps_disabled, 0, 1) },
{ INT_RANGE(fils_dh_group, 0, 65535) },
};
#undef OFFSET

1
wpa_supplicant/config_file.c
View file

@ -800,6 +800,7 @@ static void wpa_config_write_network(FILE *f, struct wpa_ssid *ssid)
INT(vht_center_freq2);
INT(pbss);
INT(wps_disabled);
INT(fils_dh_group);
#ifdef CONFIG_IEEE80211W
write_int(f, "ieee80211w", ssid->ieee80211w,
MGMT_FRAME_PROTECTION_DEFAULT);

8
wpa_supplicant/config_ssid.h
View file

@ -814,6 +814,14 @@ struct wpa_ssid {
* 1 = WPS disabled
*/
int wps_disabled;
/**
* fils_dh_group - FILS DH Group
*
* 0 = PFS disabled with FILS shared key authentication
* 1-65535 DH Group to use for FILS PFS
*/
int fils_dh_group;
};
#endif /* CONFIG_SSID_H */

2
wpa_supplicant/defconfig
View file

@ -558,6 +558,8 @@ CONFIG_PEERKEY=y
# Note: This is an experimental and not yet complete implementation. This
# should not be enabled for production use.
#CONFIG_FILS=y
# FILS shared key authentication with PFS
#CONFIG_FILS_SK_PFS=y
# Support RSN on IBSS networks
# This is needed to be able to use mode=1 network profile with proto=RSN and

3
wpa_supplicant/events.c
View file

@ -2214,7 +2214,8 @@ static int wpa_supplicant_event_associnfo(struct wpa_supplicant *wpa_s,
#ifdef CONFIG_FILS
#ifdef CONFIG_SME
if (wpa_s->sme.auth_alg == WPA_AUTH_ALG_FILS &&
if ((wpa_s->sme.auth_alg == WPA_AUTH_ALG_FILS ||
wpa_s->sme.auth_alg == WPA_AUTH_ALG_FILS_SK_PFS) &&
(!data->assoc_info.resp_frame ||
fils_process_assoc_resp(wpa_s->wpa,
data->assoc_info.resp_frame,

42
wpa_supplicant/sme.c
View file

@ -563,12 +563,23 @@ static void sme_send_authentication(struct wpa_supplicant *wpa_s,
0)
wpa_printf(MSG_DEBUG,
"SME: Try to use FILS with PMKSA caching");
resp = fils_build_auth(wpa_s->wpa);
resp = fils_build_auth(wpa_s->wpa, ssid->fils_dh_group);
if (resp) {
params.auth_alg = WPA_AUTH_ALG_FILS;
int auth_alg;
if (ssid->fils_dh_group)
wpa_printf(MSG_DEBUG,
"SME: Try to use FILS SK authentication with PFS (DH Group %u)",
ssid->fils_dh_group);
else
wpa_printf(MSG_DEBUG,
"SME: Try to use FILS SK authentication without PFS");
auth_alg = ssid->fils_dh_group ?
WPA_AUTH_ALG_FILS_SK_PFS : WPA_AUTH_ALG_FILS;
params.auth_alg = auth_alg;
params.auth_data = wpabuf_head(resp);
params.auth_data_len = wpabuf_len(resp);
wpa_s->sme.auth_alg = WPA_AUTH_ALG_FILS;
wpa_s->sme.auth_alg = auth_alg;
}
}
#endif /* CONFIG_FILS */
@ -968,7 +979,27 @@ void sme_event_auth(struct wpa_supplicant *wpa_s, union wpa_event_data *data)
#endif /* CONFIG_IEEE80211R */
#ifdef CONFIG_FILS
if (data->auth.auth_type == WLAN_AUTH_FILS_SK) {
if (data->auth.auth_type == WLAN_AUTH_FILS_SK ||
data->auth.auth_type == WLAN_AUTH_FILS_SK_PFS) {
u16 expect_auth_type;
expect_auth_type = wpa_s->sme.auth_alg ==
WPA_AUTH_ALG_FILS_SK_PFS ? WLAN_AUTH_FILS_SK_PFS :
WLAN_AUTH_FILS_SK;
if (data->auth.auth_type != expect_auth_type) {
wpa_dbg(wpa_s, MSG_DEBUG,
"SME: FILS Authentication response used different auth alg (%u; expected %u)",
data->auth.auth_type, expect_auth_type);
wpa_msg(wpa_s, MSG_INFO, WPA_EVENT_DISCONNECTED "bssid="
MACSTR
" reason=%d locally_generated=1",
MAC2STR(wpa_s->pending_bssid),
WLAN_REASON_DEAUTH_LEAVING);
wpas_connection_failed(wpa_s, wpa_s->pending_bssid);
wpa_supplicant_mark_disassoc(wpa_s);
return;
}
if (fils_process_auth(wpa_s->wpa, wpa_s->pending_bssid,
data->auth.ies, data->auth.ies_len) < 0) {
wpa_dbg(wpa_s, MSG_DEBUG,
@ -1010,7 +1041,8 @@ void sme_associate(struct wpa_supplicant *wpa_s, enum wpas_mode mode,
os_memset(&params, 0, sizeof(params));
#ifdef CONFIG_FILS
if (auth_type == WLAN_AUTH_FILS_SK) {
if (auth_type == WLAN_AUTH_FILS_SK ||
auth_type == WLAN_AUTH_FILS_SK_PFS) {
struct wpabuf *buf;
const u8 *snonce, *anonce;
const unsigned int max_hlp = 20;

5
wpa_supplicant/wpa_supplicant.conf
View file

@ -1248,6 +1248,11 @@ fast_reauth=1
# 1 = WPS disabled
#wps_disabled=0
# FILS DH Group
# 0 = PFS disabled with FILS shared key authentication (default)
# 1-65535 = DH Group to use for FILS PFS
#fils_dh_group=0
# MAC address policy
# 0 = use permanent MAC address
# 1 = use random MAC address for each ESS connection