public static byte[] authenticatedEncryption(CosemParameters parameters, byte[] data)
{
if (parameters.securityType == SecurityType.NONE)
{
return(data);
}
int ivCounter = parameters.getInvocationCounter();
int sc = 0;
switch (parameters.securityType)
{
case SecurityType.AUTHENTICATION:
sc = SC_AUTHENTICATION;
byte[] authData = new byte[parameters.ak.Length + data.Length + 1];
authData[0] = SC_AUTHENTICATION;
Array.Copy(parameters.ak, 0, authData, 1, parameters.ak.Length);
Array.Copy(data, 0, authData, parameters.ak.Length + 1, data.Length);
byte[] mac = aesGcm(new byte[0], authData, parameters, ivCounter);
byte[] data_ = new byte[data.Length + mac.Length];
Array.Copy(data, 0, data_, 0, data.Length);
Array.Copy(mac, 0, data_, data.Length, mac.Length);
data = data_;
break;
case SecurityType.AUTHENTICATION_ENCRYPTION:
sc = SC_AUTHENTICATION_ENCRYPTION;
authData = new byte[parameters.ak.Length + 1];
authData[0] = SC_AUTHENTICATION_ENCRYPTION;
Array.Copy(parameters.ak, 0, authData, 1, parameters.ak.Length);
data = aesGcm(data, authData, parameters, ivCounter);
break;
case SecurityType.ENCRYPTION:
sc = SC_ENCRYPTION;
data = aesGcm(data, new byte[0], parameters, ivCounter);
break;
default:
throw new System.InvalidOperationException();
}
try
{
System.IO.MemoryStream stream = new System.IO.MemoryStream();
stream.WriteByte((byte)sc);
stream.WriteByte((byte)(ivCounter >> 24));
stream.WriteByte((byte)(ivCounter >> 16));
stream.WriteByte((byte)(ivCounter >> 8));
stream.WriteByte((byte)(ivCounter));
stream.Write(data, 0, data.Length);
return(stream.ToArray());
}
catch (IOException)
{
throw new DlmsException(DlmsException.DlmsExceptionReason.INTERNAL_ERROR);
}
}
internal static byte[] processChallanger(CosemParameters parameters, CosemConnection connection)
{
try
{
switch (parameters.authenticationType.innerEnumValue)
{
case AuthenticationType.InnerEnum.PUBLIC:
case AuthenticationType.InnerEnum.LLS:
throw new System.InvalidOperationException();
case AuthenticationType.InnerEnum.HLS:
return(aes128(connection.challengeServerToClient, parameters.llsHlsSecret));
case AuthenticationType.InnerEnum.HLS_MD5:
return(md5(connection.challengeServerToClient, parameters.llsHlsSecret));
case AuthenticationType.InnerEnum.HLS_SHA1:
return(sha1(connection.challengeServerToClient, parameters.llsHlsSecret));
case AuthenticationType.InnerEnum.HLS_GMAC:
int ivCounter = parameters.getInvocationCounter();
System.IO.MemoryStream data = new System.IO.MemoryStream();
data.WriteByte(SC_AUTHENTICATION);
data.Write(parameters.ak, 0, parameters.ak.Length);
data.Write(connection.challengeServerToClient, 0, connection.challengeServerToClient.Length);
System.IO.MemoryStream stream = new System.IO.MemoryStream();
stream.WriteByte(SC_AUTHENTICATION);
stream.WriteByte((byte)(ivCounter >> 24));
stream.WriteByte((byte)(ivCounter >> 16));
stream.WriteByte((byte)(ivCounter >> 8));
stream.WriteByte((byte)(ivCounter));
byte[] aux = Security.aesGcm(new byte[0], data.ToArray(), parameters, ivCounter);
stream.Write(aux, 0, aux.Length);
return(stream.ToArray());
default:
throw new System.ArgumentException();
}
}
catch (IOException)
{
throw new DlmsException(DlmsException.DlmsExceptionReason.INTERNAL_ERROR);
}
}
