NewCamdMessage ParseMessage(byte[] buffer)
{
_logger.Debug("Read TripleDES Initialization Vector from encrypted message");
var ivec = buffer.Skip(buffer.Length - 8).Take(8).ToArray();
_logger.Debug("Decrypt the rest of the message");
var decryptedData = _crypto.Decrypt(buffer, buffer.Length - 8, _keyblock, ivec);
_logger.Debug("Parse decrypted message");
var len = (((decryptedData[3 + NewCamdMessage.HeaderLength] << 8) | decryptedData[4 + NewCamdMessage.HeaderLength]) & 0x0FFF) + 3;
if (len > decryptedData.Length)
{
throw new InvalidNewcamdMessage($"Decryption of the message from {Name} failed");
}
var retValue = new NewCamdMessage
{
MessageId = ((decryptedData[0] << 8) | decryptedData[1]) & 0xFFFF,
ServiceId = ((decryptedData[2] << 8) | decryptedData[3]) & 0xFFFF,
ProviderId = decryptedData[4] << 16 | decryptedData[5] << 8 | decryptedData[6],
Data = decryptedData.Skip(2 + NewCamdMessage.HeaderLength).Take(len).ToArray(),
Type = (NewCamdMessageType)decryptedData[2 + NewCamdMessage.HeaderLength]
};
_logger.Debug($"Received decrypted message msgid: {retValue.MessageId}, serviceid: {retValue.ServiceId}, providerid: {retValue.ProviderId}, length: {len}, type {retValue.Type} from {Name}");
return(retValue);
}
#pragma warning disable CA1822 // Mark members as static
public void EncryptAndDecrypt()
#pragma warning restore CA1822 // Mark members as static
{
const string Unencoded = "Foo";
byte[] encoded = EncryptionHelpers.Encrypt(
Encoding.UTF8.GetBytes(Unencoded));
string decoded = Encoding.UTF8.GetString(
EncryptionHelpers.Decrypt(encoded));
Assert.Equal(Unencoded, decoded);
}