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How to implement send and receive hl7 data in .NET in ssh connection

I'm implementing an application in .Net. I have to create a connection by SSH which is works, but the HL7 data receiving fails. The destination is a raspberry pi. So when I'm debugging the ssh client is connected, the port is forwarded, the tcp client also connected, but there is no answer for my queries. Plese suggest me some examples!
In this project I have already implemented it on Android - it works fine.
So in .Net I tried the NHapiTools library and I also tried the direct TcpClient way too. localPort = remotePort. I used localIP = "localhost"
static void Main(string[] args)
{
try
{
PrivateKeyFile file = new PrivateKeyFile(#"./key/private.key");
using (var client = new SshClient(remoteIP, sshPort, username, file))
{
client.Connect();
var ci = client.ConnectionInfo;
var port = new ForwardedPortLocal(localIP, localPort, client.ConnectionInfo.Host, remotePort);
client.AddForwardedPort(port);
port.Start();
var req = "MSH|^~\\&|TestAppName||AVR||20181107201939.357+0000||QRY^R02^QRY_R02|923456|P|2.5";
////TCP
var tcpClient = new TcpClient();
tcpClient.Connect(localIP, (int)localPort);
Byte[] data = System.Text.Encoding.ASCII.GetBytes(req);
using (var stream = tcpClient.GetStream())
{
stream.Write(data, 0, data.Length);
using (var buffer = new MemoryStream())
{
byte[] chunk = new byte[4096];
int bytesRead;
while ((bytesRead = stream.Read(chunk, 0, chunk.Length)) > 0)
{
buffer.Write(chunk, 0, bytesRead);
}
data = buffer.ToArray();
}
}
//I used this also with same result -> no respond
//SimpleMLLP
/*
var connection = new SimpleMLLPClient(localIP, localPort,
Encoding.UTF8);
var response = connection.SendHL7Message(req);
*/
}
}
catch (Exception ex)
{
Console.WriteLine(ex);
}
Console.ReadLine();
}
}
So I experinced that the buffer size is 0 in TCP (due to time out). In the SimpleMLLP test SendHK7Message method never returns

You are not implementing MLLP (also called LLP) protocol while sending message.
Description HEX ASCII Symbol
Message starting character 0B 11 <VT>
Message ending characters 1C,0D 28,13 <FS>,<CR>
This way, when you send a message to Listener (TCP/MLLP server), it looks for Start Block in your incoming data. It never finds it. It just discards your entire message considering garbage. Hence, you get nothing back from Listener.
With MLLP implemented, your message (the stuff you are writing on socket) should look something like below:
<VT>MSH|^~\\&|TestAppName||AVR||20181107201939.357+0000||QRY^R02^QRY_R02|923456|P|2.5<FS><CR>
Note the <VT>, <CR> and <FS> are place holders in above message.
You may refer to this article for detailed information (Read step 4 and onward):
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
namespace SimpleMllpHl7ClientAdvanced
{
public class Program
{
private static char END_OF_BLOCK = '\u001c';
private static char START_OF_BLOCK = '\u000b';
private static char CARRIAGE_RETURN = (char)13;
static void Main(string[] args)
{
TcpClient ourTcpClient = null;
NetworkStream networkStream = null;
var testHl7MessageToTransmit = new StringBuilder();
//a HL7 test message that is enveloped with MLLP as described in my article
testHl7MessageToTransmit.Append(START_OF_BLOCK)
.Append("MSH|^~\\&|AcmeHIS|StJohn|CATH|StJohn|20061019172719||ORM^O01|MSGID12349876|P|2.3")
.Append(CARRIAGE_RETURN)
.Append("PID|||20301||Durden^Tyler^^^Mr.||19700312|M|||88 Punchward Dr.^^Los Angeles^CA^11221^USA|||||||")
.Append(CARRIAGE_RETURN)
.Append("PV1||O|OP^^||||4652^Paulson^Robert|||OP|||||||||9|||||||||||||||||||||||||20061019172717|20061019172718")
.Append(CARRIAGE_RETURN)
.Append("ORC|NW|20061019172719")
.Append(CARRIAGE_RETURN)
.Append("OBR|1|20061019172719||76770^Ultrasound: retroperitoneal^C4|||12349876")
.Append(CARRIAGE_RETURN)
.Append(END_OF_BLOCK)
.Append(CARRIAGE_RETURN);
try
{
//initiate a TCP client connection to local loopback address at port 1080
ourTcpClient = new TcpClient();
ourTcpClient.Connect(new IPEndPoint(IPAddress.Loopback, 1080));
Console.WriteLine("Connected to server....");
//get the IO stream on this connection to write to
networkStream = ourTcpClient.GetStream();
//use UTF-8 and either 8-bit encoding due to MLLP-related recommendations
var sendMessageByteBuffer = Encoding.UTF8.GetBytes(testHl7MessageToTransmit.ToString());
if (networkStream.CanWrite)
{
//send a message through this connection using the IO stream
networkStream.Write(sendMessageByteBuffer, 0, sendMessageByteBuffer.Length);
Console.WriteLine("Data was sent data to server successfully....");
var receiveMessageByteBuffer = Encoding.UTF8.GetBytes(testHl7MessageToTransmit.ToString());
var bytesReceivedFromServer = networkStream.Read(receiveMessageByteBuffer, 0, receiveMessageByteBuffer.Length);
// Our server for this example has been designed to echo back the message
// keep reading from this stream until the message is echoed back
while (bytesReceivedFromServer > 0)
{
if (networkStream.CanRead)
{
bytesReceivedFromServer = networkStream.Read(receiveMessageByteBuffer, 0, receiveMessageByteBuffer.Length);
if (bytesReceivedFromServer == 0)
{
break;
}
}
}
var receivedMessage = Encoding.UTF8.GetString(receiveMessageByteBuffer);
Console.WriteLine("Received message from server: {0}", receivedMessage);
}
Console.WriteLine("Press any key to exit...");
Console.ReadLine();
}
catch (Exception ex)
{
//display any exceptions that occur to console
Console.WriteLine(ex.Message);
}
finally
{
//close the IO strem and the TCP connection
networkStream?.Close();
ourTcpClient?.Close();
}
}
}
}
You should modify your following line of code as below:
var req = START_OF_BLOCK + "MSH|^~\\&|TestAppName||AVR||20181107201939.357+0000||QRY^R02^QRY_R02|923456|P|2.5" + END_OF_BLOCK + CARRIAGE_RETURN;
For more open source code, you may refer to this github project.

After days of struggling I have solved the problem. The main error was with the port forwarding.
I would reccomend to use SSH.Net by Renci (There was algorithm error with Tamir ssh).
After ssh connection created I used this to port forward:
var port = new ForwardedPortLocal(localIP, localPort, "localhost", remotePort);
Check your localIP with ipconfig /all in cmd. Or use 127.0.0.1 as a loopback IP.
SimpleMLLPClient did not worked for me so I used the direct tcp client query way. Like this:
TcpClient ourTcpClient = new TcpClient();
ourTcpClient.Connect(localIP, (int)localPort);
NetworkStream networkStream = ourTcpClient.GetStream();
var sendMessageByteBuffer = Encoding.UTF8.GetBytes(testHl7MessageToTransmit.ToString());
if (networkStream.CanWrite)
{
networkStream.Write(sendMessageByteBuffer, 0, sendMessageByteBuffer.Length);
Console.WriteLine("Data was sent to server successfully....");
byte[] receiveMessageByteBuffer = new byte[ourTcpClient.ReceiveBufferSize];
var bytesReceivedFromServer = networkStream.Read(receiveMessageByteBuffer, 0, receiveMessageByteBuffer.Length);
if (bytesReceivedFromServer > 0 && networkStream.CanRead)
{
receivedMessage.Append(Encoding.UTF8.GetString(receiveMessageByteBuffer));
}
var message = receivedMessage.Replace("\0", string.Empty);
Console.WriteLine("Received message from server: {0}", message);
}
So it gave me instant answer with 0 bytes (not due timeout). And here comes Amit Joshi help. I used a query what he suggested with START_OF_BLOCK, CARRIAGE_RETURN and END_OF_BLOCK and finally started to work. Thank you Amit Joshi!
Additional info:
In Android (java/Kotlin) jsch session setPortForwardingL works fine with three params:
val session = jsch.getSession("user", sshIP, sshPort)
session.setPassword("")
jsch.addIdentity(privatekey.getAbsolutePath())
// Avoid asking for key confirmation
val prop = Properties()
prop.setProperty("StrictHostKeyChecking", "no")
session.setConfig(prop)
session.connect(5000)
session.setPortForwardingL(localForwardPort, "localhost", remotePort)
val useTls = false
val context = DefaultHapiContext()
connection = context.newClient("localhost", localForwardPort, useTls)

POP3 protocol. Operations STAT and LIST

I try to realize simple mail client. Now I can retriev messages:
// create an instance of TcpClient
TcpClient tcpclient = new TcpClient();
// HOST NAME POP SERVER and gmail uses port number 995 for POP
tcpclient.Connect("pop.gmail.com", 995);
// This is Secure Stream // opened the connection between client and POP Server
System.Net.Security.SslStream sslstream = new SslStream(tcpclient.GetStream());
// authenticate as client
sslstream.AuthenticateAsClient("pop.gmail.com");
//bool flag = sslstream.IsAuthenticated; // check flag
// Asssigned the writer to stream
StreamWriter sw = new StreamWriter(sslstream);
// Assigned reader to stream
StreamReader reader = new StreamReader(sslstream);
// refer POP rfc command, there very few around 6-9 command
sw.WriteLine("USER my_mail#gmail.com");
// sent to server
sw.Flush();
sw.WriteLine("PASS my_pass");
sw.Flush();
// this will retrive your first email
sw.WriteLine("RETR 1");
sw.Flush();
string str = string.Empty;
string strTemp = string.Empty;
while ((strTemp = reader.ReadLine()) != null)
{
// find the . character in line
if (strTemp == ".")
{
break;
}
if (strTemp.IndexOf("-ERR") != -1)
{
break;
}
str += strTemp;
}
//str = reader.ReadToEnd();
// close the connection
sw.WriteLine("QUIT");
sw.Flush();
richTextBox2.Text = str;
But when I try to realize operations STAT and LIST my programm crashes. I think there is a problem in cycle of reading streams. For operation STAT I try to read until "\r\n" (strTemp = "\r\n") and for operation LIST - ".\r\n" respectively.
This is my code for STAT:
// create an instance of TcpClient
TcpClient tcpclient = new TcpClient();
// HOST NAME POP SERVER and gmail uses port number 995 for POP
tcpclient.Connect("pop.gmail.com", 995);
// This is Secure Stream // opened the connection between client and POP Server
System.Net.Security.SslStream sslstream = new SslStream(tcpclient.GetStream());
// authenticate as client
sslstream.AuthenticateAsClient("pop.gmail.com");
//bool flag = sslstream.IsAuthenticated; // check flag
// Asssigned the writer to stream
StreamWriter sw = new StreamWriter(sslstream);
// Assigned reader to stream
StreamReader reader = new StreamReader(sslstream);
// refer POP rfc command, there very few around 6-9 command
sw.WriteLine("USER my_mail#gmail.com");
// sent to server
sw.Flush();
sw.WriteLine("PASS my_pass");
sw.Flush();
// this will retrive your first email
sw.WriteLine("STAT");
sw.Flush();
string str = string.Empty;
string strTemp = string.Empty;
while ((strTemp = reader.ReadLine()) != null)
{
// find the . character in line
if (strTemp == "\r\n")
{
break;
}
if (strTemp.IndexOf("-ERR") != -1)
{
break;
}
str += strTemp;
}
//str = reader.ReadToEnd();
// close the connection
sw.WriteLine("QUIT");
sw.Flush();
richTextBox2.Text = str;
After I press the button my main window is not responding. Where is my mistake?
Thank you!

Your app is most likely hung on ReadLine(). Note that StreamReader.ReadLine() does not include the \r\n. So your check for \r\n will never hit, hence that break statement will never hit.
You may simply need to change it to if (strTemp == ""). If that doesn't do the trick, you'll have to step through in the debugger.
Also note that blocking calls like this are not a good idea in the UI thread. You really should offload this to a background worker.

How to read the body of the message in the mail retrieve from gmail by using pop3 in c #?

This is code:
protected void Button9_Click(object sender, EventArgs e)
{
try
{
// create an instance of TcpClient
TcpClient tcpclient = new TcpClient();
// HOST NAME POP SERVER and gmail uses port number 995 for POP
tcpclient.Connect("pop.gmail.com", 995);
// This is Secure Stream // opened the connection between client and POP Server
System.Net.Security.SslStream sslstream = new SslStream(tcpclient.GetStream());
// authenticate as client
sslstream.AuthenticateAsClient("pop.gmail.com");
//bool flag = sslstream.IsAuthenticated; // check flag
// Asssigned the writer to stream
System.IO.StreamWriter sw = new StreamWriter(sslstream);
// Assigned reader to stream
System.IO.StreamReader reader = new StreamReader(sslstream);
// refer POP rfc command, there very few around 6-9 command
sw.WriteLine("USER your_gmail_user_name#gmail.com");
// sent to server
sw.Flush(); sw.WriteLine("PASS your_gmail_password");
sw.Flush();
// RETR 1 will retrive your first email. it will read content of your first email
sw.WriteLine("RETR 1");
sw.Flush();
// close the connection
sw.WriteLine("Quit ");
sw.Flush(); string str = string.Empty;
string strTemp = string.Empty;
while ((strTemp = reader.ReadLine()) != null)
{
// find the . character in line
if (strTemp == ".")
{
break;
}
if (strTemp.IndexOf("-ERR") != -1)
{
break;
}
str += strTemp;
}
textbox1.text = str;
textbox1.text += "<BR>" + "Congratulation.. ....!!! You read your first gmail email ";
}
catch (Exception ex)
{
Response.Write(ex.Message);
}
}
The message body is a bunch of what appears to be random characters. I know it's not just a bunch of random characters but some code that needs to be parsed and converted. How can I read content in "message body"?

I know i'm not directly replying to your answer but reading email is a really complex task and I think you can achieve this better and faster with an external library instead of implementing it by yourself.
There are many good implementation, i usually use OpenPop.NET which works fine and is opensource.
https://sourceforge.net/projects/hpop/
You can find many example on internet because it is really popular.
http://hpop.sourceforge.net/examples.php
you can get all mail easly:
using(Pop3Client client = new Pop3Client())
{
// Connect to the server
client.Connect("pop.gmail.com", 995, true);
// Authenticate ourselves towards the server
client.Authenticate("username#gmail.com", "password", AuthenticationMethod.UsernameAndPassword);
// Get the number of messages in the inbox
int messageCount = client.GetMessageCount();
// We want to download all messages
List<Message> allMessages = new List<Message>(messageCount);
// Messages are numbered in the interval: [1, messageCount]
// Ergo: message numbers are 1-based.
// Most servers give the latest message the highest number
for (int i = messageCount; i > 0; i--)
{
allMessages.Add(client.GetMessage(i));
}
}
you can get the full raw message
var mailbody = ASCIIEncoding.ASCII.GetString(message.RawMessage);
or if it is an utf8 encoded email:
var encodedStringAsBytes = System.Convert.FromBase64String(message.RawMessage);
var rawMessage =System.Text.Encoding.UTF8.GetString(encodedStringAsBytes);
Instead if you want only the mail body you have to dig into the mail structure:
http://hpop.sourceforge.net/documentation/OpenPop~OpenPop.Mime.MessagePart.html
I know it is not an easy task but as I stated above emails are complex objects.

Pipe is being closed Exception

Sometimes, on some machines often and on some seldom, the clients which are using my program are getting a "pipe is being closed" exception. This happens on the NamedPipeServerStream that is on .WaitForConnection(). After that, the Application totally crashes and releases a windows exception. This happens when a NamedPipeClientStream transfers information to the standalone application.
main Funktionality:
I wrote several Tools (Office Toolbars, a Service, a standalone .net Application, and a litle starter exe) that communicate together with NamedPipes.
The Service runs a NamedPipeServerStream that is always open (in state .WaitForConnection();) and the Standalone Application has a NamedPipeServerStream too.
The Toolbars and starter .exe communicate with the service. The Service then with the Standalone Application.
what kind of problems can release the pipe is being closed Exception?
Is it possible that the server sends information to the Standalone Application but closes the stream to early because the Standalone Application is not ready or something? on each NamedPipeClientStream i do a waitforpipedrain if pipeClient.IsConnected befor i close the pipeclient..
thanks for help
edit: Here an Example of a clientstream
using (NamedPipeClientStream pipeClient =
new NamedPipeClientStream(".", pipename, PipeDirection.Out))
{
// Wait for a client to connect
try
{
pipeClient.Connect(3000);
// send params to the form
using (StreamWriter sw = new StreamWriter(pipeClient))
{
sw.AutoFlush = true;
sw.WriteLine(sendtext);
}
}
// Catch the IOException that is raised if the pipe is
// broken or disconnected.
catch (Exception e)
{
if (sid != "")
{
connections.Remove(conName);
}
eventLog1.WriteEntry("SendText Fehler 1 " + e.Message);
}
finally
{
if (pipeClient.IsConnected)
{
pipeClient.WaitForPipeDrain();
}
pipeClient.Close();
pipeClient.Dispose();
}
Example of an pipeserver (that runs in a seperad thread)
NamedPipeServerStream pipeServer;
PipeSecurity pipe_security = CreateSystemIoPipeSecurity();
do
string pipename = global::TOfficeCenter.Properties.Settings.Default.pipename;
string aText = "";
pipeServer = new NamedPipeServerStream(pipename, PipeDirection.In, ONE_INSTANCE, PipeTransmissionMode.Byte,
PipeOptions.None, IN_BUF_SIZE, OUT_BUF_SIZE, pipe_security);
try
{
// Verbindung zu TOfficeCenter.exe aufbauen
try
{
IsWaiting = true;
pipeServer.WaitForConnection();
IsWaiting = false;
using (StreamReader sr = new StreamReader(pipeServer))
{
string temp;
while ((temp = sr.ReadLine()) != null)
{
aText = aText + temp;
}
}
try
{
if (aText == "")
{
empfang(null);
}
else
{
if (aText != "KillPipe")
{ // XML empfangen
XmlDocumentTC xml = new XmlDocumentTC();
xml.LoadXml(aText);
empfang(xml);
}
}
}
catch (Exception)
{
empfang(null);
}
}
catch
{...........
}
}
catch (Exception e)
{...........
}
} while (running);
pipeServer.Close();

It's possible that i finally found the problem..
I found out that after this code:
using (StreamWriter sw = new StreamWriter(pipeClient))
{
sw.AutoFlush = true;
sw.WriteLine(sendtext);
}
the pipeClient.IsConnected(); returns directly false, so that it never comes to the WaitForPipeDrain. I Now did it like that and hope that the client does not close the connection before the server is finished with reading..
using (StreamWriter sw = new StreamWriter(pipeClient))
{
sw.AutoFlush = true;
sw.WriteLine(sendtext);
pipeClient.WaitForPipeDrain();
}
Do You Think that could have solved the problem? Since i did it, i never got the error on two test-machines. But the Errors anyway happened seldom..

My use is a bit different, but I'll include the server thread in sum as it's mostly being hacked from the MSDN page at present:
MSDN: How to Use Named Pipes
Not sure if the "WaitForPipeToDrain()" is needed for me, but I took it from your code :)
I think the reset of the pipeServer each time is what cleaned up my IOException.
int threadId = Thread.CurrentThread.ManagedThreadId;
bool sentinel = true;
while (sentinel)
{
NamedPipeServerStream pipeServer =
new NamedPipeServerStream("shapspipe", PipeDirection.InOut, 1);
// Wait for a client to connect
pipeServer.WaitForConnection();
Console.WriteLine("Client connected on thread[{0}].", threadId);
try
{
// Read the request from the client. Once the client has
// written to the pipe its security token will be available.
StreamString ss = new StreamString(pipeServer);
// Verify our identity to the connected client using a
// string that the client anticipates.
ss.WriteString("I am the one true server!");
string message = ss.ReadString();
Console.WriteLine("received from client: " + message);
ss.WriteString("echo from server: " + message);
Console.WriteLine("Received from client: {0} on thread[{1}] as user: {2}.",
message, threadId, pipeServer.GetImpersonationUserName());
}
// Catch the IOException that is raised if the pipe is broken
// or disconnected.
catch (IOException e)
{
Console.WriteLine("ERROR: {0}", e.Message);
}
pipeServer.WaitForPipeDrain();
pipeServer.Close();
}

Send IMAP commands to GMail using C#

I've been trying to access my GMail account to retrieve the unread emails from my email account. However, I only con perform login... Anything after that doesn't work.
First of all I connect to the server, then send the login command and finally the examine command. The thing is that the responses that are receive refers only to the connection and to the login. After that, it just stops waiting for someting to read from the StreamReader.
try
{
// create an instance of TcpClient
TcpClient tcpclient = new TcpClient();
// HOST NAME POP SERVER and gmail uses port number 995 for POP
//tcpclient.Connect("pop.gmail.com", 995);
tcpclient.Connect("imap.gmail.com", 993);
// This is Secure Stream // opened the connection between client and POP Server
SslStream sslstream = new SslStream(tcpclient.GetStream());
// authenticate as client
sslstream.AuthenticateAsClient("imap.gmail.com");
bool flag = sslstream.IsAuthenticated; // check flag
// Asssigned the writer to stream
System.IO.StreamWriter sw = new StreamWriter(sslstream);
// Assigned reader to stream
System.IO.StreamReader reader = new StreamReader(sslstream);
sw.WriteLine("tag LOGIN user#gmail.com pass");
sw.Flush();
sw.WriteLine("tag2 EXAMINE inbox");
sw.Flush();
sw.WriteLine("tag3 LOGOUT ");
sw.Flush();
string str = string.Empty;
string strTemp = string.Empty;
try
{
while ((strTemp = reader.ReadLine()) != null)
{
Console.WriteLine(strTemp);
// find the . character in line
if (strTemp == ".")
{
//reader.Close();
break;
}
if (strTemp.IndexOf("-ERR") != -1)
{
//reader.Close();
break;
}
str += strTemp;
}
}
catch (Exception ex)
{
string s = ex.Message;
}
//reader.Close();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}

I was looking for just this sort of "Hello World" example to get me started. With the help of dkarp's answers, here's my take on Miguel's example:
static void Main( string[] args ) {
try {
TcpClient tcpclient = new TcpClient();
tcpclient.Connect( "imap.gmail.com", 993 );
SslStream sslstream = new SslStream( tcpclient.GetStream() );
sslstream.AuthenticateAsClient( "imap.gmail.com" );
if ( sslstream.IsAuthenticated ) {
StreamWriter sw = new StreamWriter( sslstream );
StreamReader sr = new StreamReader( sslstream );
sw.WriteLine( "tag LOGIN user#gmail.com pass" );
sw.Flush();
ReadResponse( "tag", sr );
sw.WriteLine( "tag2 EXAMINE inbox" );
sw.Flush();
ReadResponse( "tag2", sr );
sw.WriteLine( "tag3 LOGOUT" );
sw.Flush();
ReadResponse( "tag3", sr );
}
}
catch ( Exception ex ) {
Console.WriteLine( ex.Message );
}
}
private static void ReadResponse( string tag, StreamReader sr ) {
string response;
while ( ( response = sr.ReadLine() ) != null ) {
Console.WriteLine( response );
if ( response.StartsWith( tag, StringComparison.Ordinal ) ) {
break;
}
}
}

You might look at using a canned IMAP/SSL library instead - there is one that is still active here.
This alternative is not free.
The basis for one of these has source code that might be helpful since you want to roll your own protocol handler.

Your problem is that you're expecting POP responses from an IMAP server. POP terminates fetched messages with . and responds to other commands with a line beginning with either +OK or -ERR. IMAP doesn't. You're consuming all the server responses and then hanging, waiting for something to match your POP-like response parser. If you examine the returned data, you should see the remainder of the server's responses to your (properly-formatted) requests.
There is a possibility that the server isn't sending back responses to your second and third commands. This could be because you're trying to pipeline three requests; that is, you're sending the requests without waiting for the responses. The server is obliged to allow pipelining while in the SELECTED state, but the protocol doesn't guarantee that you can pipeline commands from the NOT AUTHENTICATED state.