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DPP: Use Transaction ID in Peer Discovery Request/Response frames

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DPP tech spec changed the contents of these frames by replacing the
public key hash attributes with a Transaction ID attribute that gets
copied from the request to the response to identify the transaction in a
simpler manner.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
This commit is contained in:
Jouni Malinen 2017-08-23 12:49:22 +03:00 committed by Jouni Malinen
parent a28675da23
commit 85fd8263a5
4 changed files with 42 additions and 79 deletions
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28
src/ap/dpp_hostapd.c
View file

@ -895,8 +895,8 @@ static void hostapd_dpp_rx_peer_disc_req(struct hostapd_data *hapd,
const u8 *buf, size_t len,
unsigned int freq)
{
const u8 *connector;
u16 connector_len;
const u8 *connector, *trans_id;
u16 connector_len, trans_id_len;
struct os_time now;
struct dpp_introduction intro;
os_time_t expire;
@ -931,6 +931,14 @@ static void hostapd_dpp_rx_peer_disc_req(struct hostapd_data *hapd,
return;
}
trans_id = dpp_get_attr(buf, len, DPP_ATTR_TRANSACTION_ID,
&trans_id_len);
if (!trans_id || trans_id_len != 1) {
wpa_printf(MSG_DEBUG,
"DPP: Peer did not include Transaction ID");
return;
}
connector = dpp_get_attr(buf, len, DPP_ATTR_CONNECTOR, &connector_len);
if (!connector) {
wpa_printf(MSG_DEBUG,
@ -966,20 +974,14 @@ static void hostapd_dpp_rx_peer_disc_req(struct hostapd_data *hapd,
}
msg = dpp_alloc_msg(DPP_PA_PEER_DISCOVERY_RESP,
2 * (4 + SHA256_MAC_LEN) +
4 + os_strlen(hapd->conf->dpp_connector));
5 + 4 + os_strlen(hapd->conf->dpp_connector));
if (!msg)
return;
/* SHA256(PK) */
wpabuf_put_le16(msg, DPP_ATTR_PEER_NET_PK_HASH);
wpabuf_put_le16(msg, SHA256_MAC_LEN);
wpabuf_put_data(msg, intro.pk_hash, SHA256_MAC_LEN);
/* SHA256(NK) */
wpabuf_put_le16(msg, DPP_ATTR_OWN_NET_NK_HASH);
wpabuf_put_le16(msg, SHA256_MAC_LEN);
wpabuf_put_data(msg, intro.nk_hash, SHA256_MAC_LEN);
/* Transaction ID */
wpabuf_put_le16(msg, DPP_ATTR_TRANSACTION_ID);
wpabuf_put_le16(msg, 1);
wpabuf_put_u8(msg, trans_id[0]);
/* DPP Connector */
wpabuf_put_le16(msg, DPP_ATTR_CONNECTOR);

30
src/common/dpp.c
View file

@ -4577,30 +4577,6 @@ fail:
}
static int dpp_netkey_hash(EVP_PKEY *key, u8 *hash)
{
EC_KEY *eckey;
unsigned char *der = NULL;
int ret, der_len;
const u8 *addr[1];
size_t len[1];
eckey = EVP_PKEY_get1_EC_KEY(key);
if (!eckey)
return -1;
EC_KEY_set_conv_form(eckey, POINT_CONVERSION_COMPRESSED);
der_len = i2d_EC_PUBKEY(eckey, &der);
EC_KEY_free(eckey);
if (der_len <= 0)
return -1;
addr[0] = der;
len[0] = der_len;
ret = sha256_vector(1, addr, len, hash);
OPENSSL_free(der);
return ret;
}
int dpp_peer_intro(struct dpp_introduction *intro, const char *own_connector,
const u8 *net_access_key, size_t net_access_key_len,
const u8 *csign_key, size_t csign_key_len,
@ -4753,12 +4729,6 @@ int dpp_peer_intro(struct dpp_introduction *intro, const char *own_connector,
goto fail;
}
if (dpp_netkey_hash(own_key, intro->nk_hash) < 0 ||
dpp_netkey_hash(peer_key, intro->pk_hash) < 0) {
wpa_printf(MSG_ERROR, "DPP: Failed to derive NK/PK hash");
goto fail;
}
ret = 0;
fail:
if (ret < 0)

4
src/common/dpp.h
View file

@ -44,12 +44,12 @@ enum dpp_attribute_id {
DPP_ATTR_CONNECTOR = 0x100D,
DPP_ATTR_CONFIG_ATTR_OBJ = 0x100E,
DPP_ATTR_BOOTSTRAP_KEY = 0x100F,
DPP_ATTR_PEER_NET_PK_HASH = 0x1010,
DPP_ATTR_OWN_NET_NK_HASH = 0x1011,
DPP_ATTR_FINITE_CYCLIC_GROUP = 0x1012,
DPP_ATTR_ENCRYPTED_KEY = 0x1013,
DPP_ATTR_ENROLLEE_NONCE = 0x1014,
DPP_ATTR_CODE_IDENTIFIER = 0x1015,
DPP_ATTR_TRANSACTION_ID = 0x1016,
};
enum dpp_status_error {
@ -201,8 +201,6 @@ struct dpp_introduction {
u8 pmkid[PMKID_LEN];
u8 pmk[PMK_LEN_MAX];
size_t pmk_len;
u8 pk_hash[SHA256_MAC_LEN];
u8 nk_hash[SHA256_MAC_LEN];
};
void dpp_bootstrap_info_free(struct dpp_bootstrap_info *info);

59
wpa_supplicant/dpp_supplicant.c
View file

@ -38,6 +38,10 @@ static void wpas_dpp_tx_status(struct wpa_supplicant *wpa_s,
static const u8 broadcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
/* Use a hardcoded Transaction ID 1 in Peer Discovery frames since there is only
* a single transaction in progress at any point in time. */
static const u8 TRANSACTION_ID = 1;
static struct dpp_configurator *
dpp_configurator_get_id(struct wpa_supplicant *wpa_s, unsigned int id)
@ -1256,8 +1260,8 @@ static void wpas_dpp_rx_peer_disc_resp(struct wpa_supplicant *wpa_s,
const u8 *buf, size_t len)
{
struct wpa_ssid *ssid;
const u8 *connector, *pk_hash, *nk_hash;
u16 connector_len, pk_hash_len, nk_hash_len;
const u8 *connector, *trans_id;
u16 connector_len, trans_id_len;
struct dpp_introduction intro;
struct rsn_pmksa_cache_entry *entry;
struct os_time now;
@ -1286,6 +1290,20 @@ static void wpas_dpp_rx_peer_disc_resp(struct wpa_supplicant *wpa_s,
return;
}
trans_id = dpp_get_attr(buf, len, DPP_ATTR_TRANSACTION_ID,
&trans_id_len);
if (!trans_id || trans_id_len != 1) {
wpa_printf(MSG_DEBUG,
"DPP: Peer did not include Transaction ID");
goto fail;
}
if (trans_id[0] != TRANSACTION_ID) {
wpa_printf(MSG_DEBUG,
"DPP: Ignore frame with unexpected Transaction ID %u",
trans_id[0]);
goto fail;
}
connector = dpp_get_attr(buf, len, DPP_ATTR_CONNECTOR, &connector_len);
if (!connector) {
wpa_printf(MSG_DEBUG,
@ -1304,36 +1322,6 @@ static void wpas_dpp_rx_peer_disc_resp(struct wpa_supplicant *wpa_s,
goto fail;
}
pk_hash = dpp_get_attr(buf, len, DPP_ATTR_PEER_NET_PK_HASH,
&pk_hash_len);
if (!pk_hash || pk_hash_len != SHA256_MAC_LEN) {
wpa_printf(MSG_DEBUG, "DPP: Peer did not include SHA256(PK)");
goto fail;
}
if (os_memcmp(pk_hash, intro.nk_hash, SHA256_MAC_LEN) != 0) {
wpa_printf(MSG_DEBUG, "DPP: SHA256(PK) mismatch");
wpa_hexdump(MSG_DEBUG, "DPP: Received SHA256(PK)",
pk_hash, pk_hash_len);
wpa_hexdump(MSG_DEBUG, "DPP: Calculated SHA256(PK)",
intro.nk_hash, SHA256_MAC_LEN);
goto fail;
}
nk_hash = dpp_get_attr(buf, len, DPP_ATTR_OWN_NET_NK_HASH,
&nk_hash_len);
if (!nk_hash || nk_hash_len != SHA256_MAC_LEN) {
wpa_printf(MSG_DEBUG, "DPP: Peer did not include SHA256(NK)");
goto fail;
}
if (os_memcmp(nk_hash, intro.pk_hash, SHA256_MAC_LEN) != 0) {
wpa_printf(MSG_DEBUG, "DPP: SHA256(NK) mismatch");
wpa_hexdump(MSG_DEBUG, "DPP: Received SHA256(NK)",
nk_hash, nk_hash_len);
wpa_hexdump(MSG_DEBUG, "DPP: Calculated SHA256(NK)",
intro.pk_hash, SHA256_MAC_LEN);
goto fail;
}
entry = os_zalloc(sizeof(*entry));
if (!entry)
goto fail;
@ -1872,10 +1860,15 @@ int wpas_dpp_check_connect(struct wpa_supplicant *wpa_s, struct wpa_ssid *ssid,
MACSTR, MAC2STR(bss->bssid));
msg = dpp_alloc_msg(DPP_PA_PEER_DISCOVERY_REQ,
4 + os_strlen(ssid->dpp_connector));
5 + 4 + os_strlen(ssid->dpp_connector));
if (!msg)
return -1;
/* Transaction ID */
wpabuf_put_le16(msg, DPP_ATTR_TRANSACTION_ID);
wpabuf_put_le16(msg, 1);
wpabuf_put_u8(msg, TRANSACTION_ID);
/* DPP Connector */
wpabuf_put_le16(msg, DPP_ATTR_CONNECTOR);
wpabuf_put_le16(msg, os_strlen(ssid->dpp_connector));