OWE: Support DH groups 20 (NIST P-384) and 21 (NIST P-521) in station

This extends OWE support in wpa_supplicant to allow DH groups 20 and 21
to be used in addition to the mandatory group 19 (NIST P-256). The group
is configured using the new network profile parameter owe_group.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
This commit is contained in:
Jouni Malinen 2017-10-08 16:39:08 +03:00 committed by Jouni Malinen
parent 7a12edd163
commit ec9f483774
9 changed files with 97 additions and 18 deletions

View file

@ -16,6 +16,8 @@
#include "crypto/random.h"
#include "crypto/aes_siv.h"
#include "crypto/sha256.h"
#include "crypto/sha384.h"
#include "crypto/sha512.h"
#include "common/ieee802_11_defs.h"
#include "common/ieee802_11_common.h"
#include "eap_common/eap_defs.h"
@ -4168,15 +4170,27 @@ int wpa_fils_is_completed(struct wpa_sm *sm)
#ifdef CONFIG_OWE
struct wpabuf * owe_build_assoc_req(struct wpa_sm *sm)
struct wpabuf * owe_build_assoc_req(struct wpa_sm *sm, u16 group)
{
struct wpabuf *ie = NULL, *pub = NULL;
size_t prime_len;
if (group == 19)
prime_len = 32;
else if (group == 20)
prime_len = 48;
else if (group == 21)
prime_len = 66;
else
return NULL;
crypto_ecdh_deinit(sm->owe_ecdh);
sm->owe_ecdh = crypto_ecdh_init(OWE_DH_GROUP);
sm->owe_ecdh = crypto_ecdh_init(group);
if (!sm->owe_ecdh)
goto fail;
sm->owe_group = group;
pub = crypto_ecdh_get_pubkey(sm->owe_ecdh, 0);
pub = wpabuf_zeropad(pub, prime_len);
if (!pub)
goto fail;
@ -4186,7 +4200,7 @@ struct wpabuf * owe_build_assoc_req(struct wpa_sm *sm)
wpabuf_put_u8(ie, WLAN_EID_EXTENSION);
wpabuf_put_u8(ie, 1 + 2 + wpabuf_len(pub));
wpabuf_put_u8(ie, WLAN_EID_EXT_OWE_DH_PARAM);
wpabuf_put_le16(ie, OWE_DH_GROUP);
wpabuf_put_le16(ie, group);
wpabuf_put_buf(ie, pub);
wpabuf_free(pub);
wpa_hexdump_buf(MSG_DEBUG, "OWE: Diffie-Hellman Parameter element",
@ -4208,10 +4222,11 @@ int owe_process_assoc_resp(struct wpa_sm *sm, const u8 *resp_ies,
u16 group;
struct wpabuf *secret, *pub, *hkey;
int res;
u8 prk[SHA256_MAC_LEN], pmkid[SHA256_MAC_LEN];
u8 prk[SHA512_MAC_LEN], pmkid[SHA512_MAC_LEN];
const char *info = "OWE Key Generation";
const u8 *addr[2];
size_t len[2];
size_t hash_len, prime_len;
if (!resp_ies ||
ieee802_11_parse_elems(resp_ies, resp_ies_len, &elems, 1) ==
@ -4223,7 +4238,7 @@ int owe_process_assoc_resp(struct wpa_sm *sm, const u8 *resp_ies,
}
group = WPA_GET_LE16(elems.owe_dh);
if (group != OWE_DH_GROUP) {
if (group != sm->owe_group) {
wpa_printf(MSG_INFO,
"OWE: Unexpected Diffie-Hellman group in response: %u",
group);
@ -4235,9 +4250,19 @@ int owe_process_assoc_resp(struct wpa_sm *sm, const u8 *resp_ies,
return -1;
}
if (group == 19)
prime_len = 32;
else if (group == 20)
prime_len = 48;
else if (group == 21)
prime_len = 66;
else
return -1;
secret = crypto_ecdh_set_peerkey(sm->owe_ecdh, 0,
elems.owe_dh + 2,
elems.owe_dh_len - 2);
secret = wpabuf_zeropad(secret, prime_len);
if (!secret) {
wpa_printf(MSG_DEBUG, "OWE: Invalid peer DH public key");
return -1;
@ -4257,8 +4282,21 @@ int owe_process_assoc_resp(struct wpa_sm *sm, const u8 *resp_ies,
len[0] = wpabuf_len(pub);
addr[1] = elems.owe_dh + 2;
len[1] = elems.owe_dh_len - 2;
res = sha256_vector(2, addr, len, pmkid);
if (res < 0) {
if (group == 19) {
res = sha256_vector(2, addr, len, pmkid);
hash_len = SHA256_MAC_LEN;
} else if (group == 20) {
res = sha384_vector(2, addr, len, pmkid);
hash_len = SHA384_MAC_LEN;
} else if (group == 21) {
res = sha512_vector(2, addr, len, pmkid);
hash_len = SHA512_MAC_LEN;
} else {
res = -1;
hash_len = 0;
}
pub = wpabuf_zeropad(pub, prime_len);
if (res < 0 || !pub) {
wpabuf_free(pub);
wpabuf_clear_free(secret);
return -1;
@ -4274,26 +4312,40 @@ int owe_process_assoc_resp(struct wpa_sm *sm, const u8 *resp_ies,
wpabuf_put_buf(hkey, pub); /* C */
wpabuf_free(pub);
wpabuf_put_data(hkey, elems.owe_dh + 2, elems.owe_dh_len - 2); /* A */
wpabuf_put_le16(hkey, OWE_DH_GROUP); /* group */
res = hmac_sha256(wpabuf_head(hkey), wpabuf_len(hkey),
wpabuf_head(secret), wpabuf_len(secret), prk);
wpabuf_put_le16(hkey, sm->owe_group); /* group */
if (group == 19)
res = hmac_sha256(wpabuf_head(hkey), wpabuf_len(hkey),
wpabuf_head(secret), wpabuf_len(secret), prk);
else if (group == 20)
res = hmac_sha384(wpabuf_head(hkey), wpabuf_len(hkey),
wpabuf_head(secret), wpabuf_len(secret), prk);
else if (group == 21)
res = hmac_sha512(wpabuf_head(hkey), wpabuf_len(hkey),
wpabuf_head(secret), wpabuf_len(secret), prk);
wpabuf_clear_free(hkey);
wpabuf_clear_free(secret);
if (res < 0)
return -1;
wpa_hexdump_key(MSG_DEBUG, "OWE: prk", prk, SHA256_MAC_LEN);
wpa_hexdump_key(MSG_DEBUG, "OWE: prk", prk, hash_len);
/* PMK = HKDF-expand(prk, "OWE Key Generation", n) */
res = hmac_sha256_kdf(prk, SHA256_MAC_LEN, NULL, (const u8 *) info,
os_strlen(info), sm->pmk, PMK_LEN);
os_memset(prk, 0, SHA256_MAC_LEN);
if (group == 19)
res = hmac_sha256_kdf(prk, hash_len, NULL, (const u8 *) info,
os_strlen(info), sm->pmk, hash_len);
else if (group == 20)
res = hmac_sha384_kdf(prk, hash_len, NULL, (const u8 *) info,
os_strlen(info), sm->pmk, hash_len);
else if (group == 21)
res = hmac_sha512_kdf(prk, hash_len, NULL, (const u8 *) info,
os_strlen(info), sm->pmk, hash_len);
os_memset(prk, 0, SHA512_MAC_LEN);
if (res < 0)
return -1;
sm->pmk_len = PMK_LEN;
sm->pmk_len = hash_len;
wpa_hexdump_key(MSG_DEBUG, "OWE: PMK", sm->pmk, PMK_LEN);
wpa_hexdump_key(MSG_DEBUG, "OWE: PMK", sm->pmk, sm->pmk_len);
wpa_hexdump(MSG_DEBUG, "OWE: PMKID", pmkid, PMKID_LEN);
/* TODO: Add PMKSA cache entry */

View file

@ -457,7 +457,7 @@ struct wpabuf * fils_build_assoc_req(struct wpa_sm *sm, const u8 **kek,
unsigned int num_hlp);
int fils_process_assoc_resp(struct wpa_sm *sm, const u8 *resp, size_t len);
struct wpabuf * owe_build_assoc_req(struct wpa_sm *sm);
struct wpabuf * owe_build_assoc_req(struct wpa_sm *sm, u16 group);
int owe_process_assoc_resp(struct wpa_sm *sm, const u8 *resp_ies,
size_t resp_ies_len);

View file

@ -161,6 +161,7 @@ struct wpa_sm {
#ifdef CONFIG_OWE
struct crypto_ecdh *owe_ecdh;
u16 owe_group;
#endif /* CONFIG_OWE */
};

View file

@ -263,6 +263,11 @@ ifdef CONFIG_OWE
L_CFLAGS += -DCONFIG_OWE
NEED_ECC=y
NEED_HMAC_SHA256_KDF=y
NEED_HMAC_SHA384_KDF=y
NEED_HMAC_SHA512_KDF=y
NEED_SHA256=y
NEED_SHA384=y
NEED_SHA512=y
endif
ifdef CONFIG_FILS

View file

@ -296,6 +296,11 @@ ifdef CONFIG_OWE
CFLAGS += -DCONFIG_OWE
NEED_ECC=y
NEED_HMAC_SHA256_KDF=y
NEED_HMAC_SHA384_KDF=y
NEED_HMAC_SHA512_KDF=y
NEED_SHA256=y
NEED_SHA384=y
NEED_SHA512=y
endif
ifdef CONFIG_FILS

View file

@ -2281,6 +2281,7 @@ static const struct parse_data ssid_fields[] = {
{ STR_LEN(dpp_csign) },
{ INT(dpp_csign_expiry) },
#endif /* CONFIG_DPP */
{ INT_RANGE(owe_group, 0, 65535) },
};
#undef OFFSET

View file

@ -873,6 +873,7 @@ static void wpa_config_write_network(FILE *f, struct wpa_ssid *ssid)
STR(dpp_csign);
INT(dpp_csign_expiry);
#endif /* CONFIG_DPP */
INT(owe_group);
#ifdef CONFIG_HT_OVERRIDES
INT_DEF(disable_ht, DEFAULT_DISABLE_HT);
INT_DEF(disable_ht40, DEFAULT_DISABLE_HT40);

View file

@ -893,6 +893,17 @@ struct wpa_ssid {
* 0 indicates no expiration.
*/
unsigned int dpp_csign_expiry;
/**
* owe_group - OWE DH Group
*
* 0 = use default (19)
* 1-65535 DH Group to use for OWE
*
* Groups 19 (NIST P-256), 20 (NIST P-384), and 21 (NIST P-521) are
* currently supported.
*/
int owe_group;
};
#endif /* CONFIG_SSID_H */

View file

@ -1195,8 +1195,11 @@ void sme_associate(struct wpa_supplicant *wpa_s, enum wpas_mode mode,
if (auth_type == WLAN_AUTH_OPEN &&
wpa_s->key_mgmt == WPA_KEY_MGMT_OWE) {
struct wpabuf *owe_ie;
u16 group = OWE_DH_GROUP;
owe_ie = owe_build_assoc_req(wpa_s->wpa);
if (wpa_s->current_ssid && wpa_s->current_ssid->owe_group)
group = wpa_s->current_ssid->owe_group;
owe_ie = owe_build_assoc_req(wpa_s->wpa, group);
if (!owe_ie) {
wpa_printf(MSG_ERROR,
"OWE: Failed to build IE for Association Request frame");