Dynamics Community Forum Thread Details

Hi,

I'm working on a scenario in D365 F&O where I need to connect to an SFTP server to send and read files. The SFTP server requires authentication using a username and private key (no password).
To achieve this, I created a C# class library that uses Renci.SshNet to establish the SFTP connection. I then call this C# code from X++. The connection returns success, which means the authentication is working.

However, when I try to access the SftpClient instance from X++ -- for example, to check if the connection is still active or to perform operations like file listing -- I encounter the below error:

Cannot access a disposed object. Object name: 'Renci.SshNet.SftpClient'.

Has anyone encountered this issue before? Is there a recommended pattern for handling SftpClient in a way that it works reliably with X++?

Any help or examples would be greatly appreciated.

My X++ code:

using SFTPConnection;
using Renci.SshNet;
using Renci.SshNet.Sftp;
using Renci.SshNet.SftpClient;

public class ConnectSFTPServer
{
    public static void main(Args args)
    {
        System.Exception ex;
        //Renci.SshNet.SftpClient sftpClient;
        SftpClient sftpClient;
        System.IO.Stream  stream;
        str connectionStatus;

        try
        {
            System.IO.Stream publicKeyStream;
            
            //I get my private key's stream here
            sftpClient = SFTPConnection.SFTPConnectionAndUploadFile::ConnectSFTP('000.000.000.00', 22, 'XYZXYZ', 'XYZXYZ', publicKeyStream, 'XYZXYZ');

            if(sftpClient != null)
            {
                ttsBegin;
                
                if (sftpClient.IsConnected) //I got error in this line
                    connectionStatus += 'Connected';
                else
                {
                    sftpClient.Connect();
                }
                sftpClient.Disconnect();
                sftpClient.Dispose();
                ttscommit;
            }
            Info(connectionStatus);
        }
        catch(ex)
        {
            System.String messageEx = ex.Message;
            info(strFmt("%1 - %2", connectionStatus, messageEx));
        }
    }
}

My C# code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Renci.SshNet;
using Renci.SshNet.Sftp;
using System.IO;
using System.Net;
using System.Linq;
using System.Runtime.CompilerServices;

namespace SFTPConnection
{
    public class SFTPConnectionAndUploadFile
    {
        public static SftpClient ConnectSFTP(string host, int port, string username, string password, Stream privateKeyFileStream, string passphrase)
        {
            List<AuthenticationMethod> methods;
            SftpClient sftpClient = (SftpClient)null;

            if (privateKeyFileStream != null)
            {
                PrivateKeyFile privateKeyFile = new PrivateKeyFile(privateKeyFileStream, passphrase);
                methods = new List<AuthenticationMethod>
                {
                    new PrivateKeyAuthenticationMethod(username, privateKeyFile)
                };
            }
            else
            {
                methods = new List<AuthenticationMethod>
                {
                    new PasswordAuthenticationMethod(username, password)
                };
            }
            try
            {
                var connectionInfo = new ConnectionInfo(host, port, username, methods.ToArray());
                using (sftpClient = new SftpClient(connectionInfo))
                {
                    sftpClient.Connect();
                    if (!sftpClient.IsConnected)
                    {
                        sftpClient = null;
                    }
                }
                return sftpClient;
            }

            catch (Exception ex)
            {
                ((BaseClient)sftpClient)?.Dispose();
                return (SftpClient)null;
            }
        }
    }
}

Note: If I call the C# method from X++, I got "Success" message only.

C# Code:

public static string SFTPConnect(string host, int port, string username, string password, Stream privateKeyFileStream, string passphrase)
        {
            List<AuthenticationMethod> methods;
            string successStr;

            if (privateKeyFileStream != null)
            {
                PrivateKeyFile privateKeyFile = new PrivateKeyFile(privateKeyFileStream, passphrase);
                methods = new List<AuthenticationMethod>
                {
                    new PrivateKeyAuthenticationMethod(username, privateKeyFile)
                };
            }
            else
            {
                methods = new List<AuthenticationMethod>
                {
                    new PasswordAuthenticationMethod(username, password)
                };
}
            try
            {
                var connectionInfo = new ConnectionInfo(host, port, username, methods.ToArray());
                using (SftpClient sftpclient = new SftpClient(connectionInfo))
                {
                    sftpclient.Connect();
                    if (sftpclient.IsConnected)
                        successStr = "Connected";
                    else
                        successStr = "Not Connected";

                    sftpclient.Disconnect();
                    sftpclient.Dispose();
                }
            }

            catch (Exception ex)
            {
                successStr = "Fail";
            }
            return successStr;
        }

Categories:

Dynamics 365 Finance