/// <summary>
/// This is to be called from the concrete communication channel.S
/// </summary>
/// <param name="receivedData"></param>
protected void OnRaisePortRequestReceived(byte[] receivedData, string sender)
{
Int32 port = 0;
try
{
var ms = new MemoryStream(receivedData);
using BinaryReader sr = new BinaryReader(ms);
var salt = sr.ReadBytes(EncryptionUtils.saltSize);
port = sr.ReadInt32();
var encryptedText = sr.ReadBytes(1000);
//now we should try to decrypt the data.
var portRule = _configuration.GetRuleFromTcpPort(port);
if (portRule == null)
{
throw new SecurityException($"Unable to find rule for requested port {port}");
}
var decrypted = Encryptor.SimmetricDecrypt(portRule.Secret, salt, encryptedText);
var decryptedDeserializedText = Encoding.UTF8.GetString(decrypted);
var request = JsonConvert.DeserializeObject <OpenPortRequest>(decryptedDeserializedText);
OpenPortRequestReceived?.Invoke(this, new OpenPortRequestEventArgs(request));
}
catch (CryptographicException)
{
throw new SecurityException($"Wrong password received trying to access port {port} from {sender}");
}
catch (Exception ex)
{
throw new SecurityException($"Malformed packets received from {sender} - {ex}");
}
}
/// <summary>
/// This is to be called from the concrete communication channel.S
/// </summary>
/// <param name="receivedData"></param>
protected void OnRaisePortRequestReceived(byte[] receivedData, string sender)
{
var transmissionData = JsonConvert.DeserializeObject <TransmissionData>(
Encoding.UTF8.GetString(receivedData));
var loadPublicKey = _configuration.LoadPublicKey(transmissionData.Sender);
Encryptor.Verify(transmissionData.Request, transmissionData.Signature, loadPublicKey);
//if we reach here, signature is ok, we can simply proceed
var request = JsonConvert.DeserializeObject <OpenPortRequest>(
Encoding.UTF8.GetString(transmissionData.Request));
//port rule exists?
var rule = _configuration.GetRuleFromTcpPort(request.PortToOpen);
if (rule == null)
{
Log.Error("Received valid message to open port {port} that has no rule", request.PortToOpen);
throw new SecurityException("Error");
}
OpenPortRequestReceived?.Invoke(this, new OpenPortRequestEventArgs(request));
}