Interworking: Add credential realm to EAP-TLS identity

If the configured credential includes a username without '@' (i.e., no
realm) in it and a realm, combine these to form the EAP-Request/Identity
value as "<username>@<realm>" for EAP-TLS. This was already done for
EAP-TTLS as part of the anonymous NAI conversion, but EAP-TLS could have
ended up using a username without any realm information which would be
unlikely to work properly with roaming cases.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

wpa_supplicant/interworking.c

@@ -1451,7 +1451,24 @@ static int interworking_set_eap_params(struct wpa_ssid *ssid,
 		os_free(anon);
 	}
 
-	if (cred->username && cred->username[0] &&
+	if (!ttls && cred->username && cred->username[0] && cred->realm &&
+	    !os_strchr(cred->username, '@')) {
+		char *id;
+		size_t buflen;
+		int res;
+
+		buflen = os_strlen(cred->username) + 1 +
+			os_strlen(cred->realm) + 1;
+
+		id = os_malloc(buflen);
+		if (!id)
+			return -1;
+		os_snprintf(id, buflen, "%s@%s", cred->username, cred->realm);
+		res = wpa_config_set_quoted(ssid, "identity", id);
+		os_free(id);
+		if (res < 0)
+			return -1;
+	} else if (cred->username && cred->username[0] &&
 	    wpa_config_set_quoted(ssid, "identity", cred->username) < 0)
 		return -1;