Calculate the password requested by ethernet gateways from the Legrand / Bticino MyHome OpenWebNet home automation system when the user's ip address is not in the gateway's whitelist

'''Note:''' Factory default password is '12345'. Changing it is highly recommended !

conversation goes as follows

<pre>← *#*1##
→ *99*0##
← *#603356072##</pre>

at which point a password should be sent back, calculated from the "password open" that is set in the gateway, and the nonce that was just sent

<pre>→ *#25280520##
← *#*1##</pre>