EAP-PAX: Check hmac_sha1_vector() return value

This function can fail at least in theory, so check its return value
before proceeding. This is mainly helping automated test case coverage
to reach some more error paths.

Signed-off-by: Jouni Malinen <j@w1.fi>

src/eap_common/eap_pax_common.c

@@ -57,7 +57,8 @@ int eap_pax_kdf(u8 mac_id, const u8 *key, size_t key_len,
 	left = output_len;
 	for (counter = 1; counter <= (u8) num_blocks; counter++) {
 		size_t clen = left > EAP_PAX_MAC_LEN ? EAP_PAX_MAC_LEN : left;
-		hmac_sha1_vector(key, key_len, 3, addr, len, mac);
+		if (hmac_sha1_vector(key, key_len, 3, addr, len, mac) < 0)
+			return -1;
 		os_memcpy(pos, mac, clen);
 		pos += clen;
 		left -= clen;
@@ -106,7 +107,8 @@ int eap_pax_mac(u8 mac_id, const u8 *key, size_t key_len,
 	len[2] = data3_len;
 
 	count = (data1 ? 1 : 0) + (data2 ? 1 : 0) + (data3 ? 1 : 0);
-	hmac_sha1_vector(key, key_len, count, addr, len, hash);
+	if (hmac_sha1_vector(key, key_len, count, addr, len, hash) < 0)
+		return -1;
 	os_memcpy(mac, hash, EAP_PAX_MAC_LEN);
 
 	return 0;

src/eap_peer/eap_pax.c

@@ -276,10 +276,10 @@ static struct wpabuf * eap_pax_process_std_3(struct eap_pax_data *data,
 	left -= 2;
 	wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: MAC_CK(B, CID)",
 		    pos, EAP_PAX_MAC_LEN);
-	eap_pax_mac(data->mac_id, data->ck, EAP_PAX_CK_LEN,
-		    data->rand.r.y, EAP_PAX_RAND_LEN,
-		    (u8 *) data->cid, data->cid_len, NULL, 0, mac);
-	if (os_memcmp_const(pos, mac, EAP_PAX_MAC_LEN) != 0) {
+	if (eap_pax_mac(data->mac_id, data->ck, EAP_PAX_CK_LEN,
+			data->rand.r.y, EAP_PAX_RAND_LEN,
+			(u8 *) data->cid, data->cid_len, NULL, 0, mac) < 0 ||
+	    os_memcmp_const(pos, mac, EAP_PAX_MAC_LEN) != 0) {
 		wpa_printf(MSG_INFO, "EAP-PAX: Invalid MAC_CK(B, CID) "
 			   "received");
 		wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: expected MAC_CK(B, CID)",
@@ -306,9 +306,12 @@ static struct wpabuf * eap_pax_process_std_3(struct eap_pax_data *data,
 	/* Optional ADE could be added here, if needed */
 
 	rpos = wpabuf_put(resp, EAP_PAX_ICV_LEN);
-	eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
-		    wpabuf_head(resp), wpabuf_len(resp) - EAP_PAX_ICV_LEN,
-		    NULL, 0, NULL, 0, rpos);
+	if (eap_pax_mac(data->mac_id, data->ick, EAP_PAX_ICK_LEN,
+			wpabuf_head(resp), wpabuf_len(resp) - EAP_PAX_ICV_LEN,
+			NULL, 0, NULL, 0, rpos) < 0) {
+		wpabuf_free(resp);
+		return NULL;
+	}
 	wpa_hexdump(MSG_MSGDUMP, "EAP-PAX: ICV", rpos, EAP_PAX_ICV_LEN);
 
 	data->state = PAX_DONE;
@@ -472,9 +475,13 @@ static u8 * eap_pax_getKey(struct eap_sm *sm, void *priv, size_t *len)
 		return NULL;
 
 	*len = EAP_MSK_LEN;
-	eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN,
-		    "Master Session Key", data->rand.e, 2 * EAP_PAX_RAND_LEN,
-		    EAP_MSK_LEN, key);
+	if (eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN,
+			"Master Session Key",
+			data->rand.e, 2 * EAP_PAX_RAND_LEN,
+			EAP_MSK_LEN, key) < 0) {
+		os_free(key);
+		return NULL;
+	}
 
 	return key;
 }
@@ -493,10 +500,13 @@ static u8 * eap_pax_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
 		return NULL;
 
 	*len = EAP_EMSK_LEN;
-	eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN,
-		    "Extended Master Session Key",
-		    data->rand.e, 2 * EAP_PAX_RAND_LEN,
-		    EAP_EMSK_LEN, key);
+	if (eap_pax_kdf(data->mac_id, data->mk, EAP_PAX_MK_LEN,
+			"Extended Master Session Key",
+			data->rand.e, 2 * EAP_PAX_RAND_LEN,
+			EAP_EMSK_LEN, key) < 0) {
+		os_free(key);
+		return NULL;
+	}
 
 	return key;
 }