private void DecryptFrame(MBusFrame data)
{
DriverContext.Logger.LogTrace($"Check frame {data?.CiField}");
if (data != null && data.CiField == 0x5B)
{
var controlHigh = data.RawData.Span[18];
DriverContext.Logger.LogTrace($"Check frame if frame is supported {controlHigh}");
switch (controlHigh & 0x0F)
{
case 5:
{
if (!(OmsHelper.AesDecrypt(_aesKey, data, _logger) is VariableDataFrame variableDataFrame))
{
DriverContext.Logger.LogError("Could not encrypt data frame");
return;
}
foreach (var child in Children)
{
if (child is OmsDriverAttribute att)
{
att.SetData(variableDataFrame);
}
}
break;
}
}
}
}
public void Test_MBusFrame_Get_Iv()
{
var excpectedIv = Automatica.Core.Driver.Utility.Utils.StringToByteArray("2D4C00000000010E0D0D0D0D0D0D0D0D");
var frame = MBusFrame.FromByteArray(MBusFrameType.LongFrame, NullLogger.Instance,
Automatica.Core.Driver.Utility.Utils.StringToByteArray(
"685F5F6853F05B000000002D4C010E0D0050053FD0FEB726760CC7AAF0B52B41F0C541BD6306DCD8B91B3DA2311EF13D2514D0960082161EFEC4B6CB1E0B3328BE6177DCA594C1280024A835F1D655BA7182B256E94BD33AC0A6B08DA46781EB4E91E01216"));
var iv = OmsHelper.GetIvFromMBusFrame(frame);
Assert.Equal(excpectedIv, iv);
}
public void Test_MBusFrame_Decrypt()
{
var expectedData = Automatica.Core.Driver.Utility.Utils.StringToByteArray(
"2F2F066D42222C5024100403C9D58D0004833C2BCA4B008410FB827386291D008410FB82F33CE5555900042B0000000004AB3CCD05000004FB140000000004FB943CA30100000483FF04000000002F2F");
var frame = MBusFrame.FromByteArray(MBusFrameType.LongFrame, NullLogger.Instance,
Automatica.Core.Driver.Utility.Utils.StringToByteArray(
"685F5F6873F05B000000002D4C010E00005005F72A3BA99D9128AB6008BEEE5336CA296EA1FFD143471C72DEAE2F716AB169FF071CC08605BC4EE99FC9D36ADE999BC910605B159ECBA642961D47560EB9C1E18071A883A18E7D5D9C8D81B9989880D6B016"));
var key = "57B7CBDF2154C01795C75CCCEAD572CF";
var aesKey = Automatica.Core.Driver.Utility.Utils.StringToByteArray(key);
var decryptedFrame = OmsHelper.AesDecryptFrame(aesKey, frame);
Assert.Equal(expectedData, decryptedFrame);
}
private void DecryptFrame(MBusFrame data)
{
if (data != null && data.CiField == 0x5B)
{
var controlHigh = data.RawData.Span[OffsetUserData + 11];
var controlLow = data.RawData.Span[OffsetUserData + 10];
switch (controlHigh & 0x0F)
{
case 5:
{
int countEncBlocks = controlLow >> 4;
System.Console.WriteLine(
$"AES with dyn.init vector {countEncBlocks} d 16 byte blocks plus % d unencrypted data {data.RawData.Length - 12 - 16 * countEncBlocks}");
var encrypted = OmsHelper.AesDecrypt(_aesKey, data, NullLogger.Instance);
break;
}
}
}
}
