EAP-PEAP peer: Check SHA1 result when deriving Compond_MAC

This handles a mostly theoretical case where hmac_sha1_vector() might
fail for some reason.

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

src/eap_peer/eap_peap.c

@@ -334,7 +334,8 @@ static int eap_tlv_add_cryptobinding(struct eap_sm *sm,
 		    addr[0], len[0]);
 	wpa_hexdump(MSG_MSGDUMP, "EAP-PEAP: Compound_MAC data 2",
 		    addr[1], len[1]);
-	hmac_sha1_vector(data->cmk, 20, 2, addr, len, mac);
+	if (hmac_sha1_vector(data->cmk, 20, 2, addr, len, mac) < 0)
+		return -1;
 	wpa_hexdump(MSG_MSGDUMP, "EAP-PEAP: Compound_MAC", mac, SHA1_MAC_LEN);
 	data->crypto_binding_used = 1;