does anybody know why UPNP GetSecurityKeys option gives me null wpa password?

the WLANConfiguration.xml

the part where GetSecurityKeys is mentioned

<action>
<name>GetSecurityKeys</name>
<argumentList>
<argument>
<name>NewWEPKey0</name>
<direction>out</direction>
<relatedStateVariable>WEPKey</relatedStateVariable>
</argument>
<argument>
<name>NewWEPKey1</name>
<direction>out</direction>
<relatedStateVariable>WEPKey</relatedStateVariable>
</argument>
<argument>
<name>NewWEPKey2</name>
<direction>out</direction>
<relatedStateVariable>WEPKey</relatedStateVariable>
</argument>
<argument>
<name>NewWEPKey3</name>
<direction>out</direction>
<relatedStateVariable>WEPKey</relatedStateVariable>
</argument>
<argument>
<name>NewPreSharedKey</name>
<direction>out</direction>
<relatedStateVariable>PreSharedKey</relatedStateVariable>
</argument>
<argument>
<name>NewKeyPassphrase</name>
<direction>out</direction>
<relatedStateVariable>KeyPassphrase</relatedStateVariable>
</argument>
</argumentList>

i tried googling and the only thing i found was a pdf file called UPnP-gw-WLANConfiguration-v1-Service.pdf the only null word i found in it is this and it have nothing to do with my problem !

i don’t even have that NewPreSharedKeyIndex that is mentioned there in my wlan xml file

It’s an intended security mechanism

As critical info like the WIFI password shouldn’t be Grabbable thro some insecure service like UPNP