Decode WienerNetze Smartmeter ISKRAEMECO AM550 HDLC packets from your infrared interface

decode_wn_isk_am550_smartmeter.php

<?php
# use this to decode WienerNetze Smartmeter ISKRAEMECO AM550 HDLC packets from your infrared interface
# example key and data is designed to decipher as real example

#paste your AES-key here, taken from WienerNetze Webportal https://www.wienernetze.at/wnapp/smapp/ -> Anlagedaten
$key='aabbccddeeff00112233445566778899';

#paste a full HDLC frame here: starting 7ea067 ending 7e, should be 210 hex digits = 105 bytes = 0x69 -> length byte 3 shows 0x67
$data='7ea067cf022313fbf1e6e700db0844556677889900aa4f20888877775540d5496ab897685e9b7e469942209b881fe280526f77c9d1dee763afb463a9bbe88449cb3fe79725875de945a405cb0f3119d3e06e3c4790130a29bc090cdf4b323cd7019d628ca255fce57e';

#prepare
$st=substr($data, 28,16);
$ic=substr($data, 48, 8);
$iv=$st.$ic.'00000002';
$enc=substr($data, 56, 148);

#decode
$dec=bin2hex(openssl_decrypt(hex2bin($enc), 'aes-128-ctr', hex2bin($key), 1, hex2bin($iv)));
print $dec;

#parse
$a=substr($dec, 70, 8);
$b=substr($dec, 80, 8);
$c=substr($dec, 90, 8);
$d=substr($dec,100, 8);
$e=substr($dec,110, 8);
$f=substr($dec,120, 8);
$g=substr($dec,130, 8);
$h=substr($dec,140, 8);

#output
print "+A: ".hexdec($a)/1000 . "kWh";
print "-A: ".hexdec($b)/1000 . "kWh";
print "+R: ".hexdec($c)/1000 . "kvarh";
print "-R: ".hexdec($d)/1000 . "kvarh";
print "+P: ".hexdec($e) . "W";
print "-P: ".hexdec($f) . "W";
print "+Q: ".hexdec($g) . "var";
print "-Q: ".hexdec($h) . "var";

?>