Unable to upload a file SFTP using SSH.NET in C# - Permission Denied

Question

I am trying to upload a file using SFTP protocol using C# using SSH.NET library. Below is the code I am using

FileInfo f=new FileInfo("C:\\mdu\\abcd.xml");            
string uploadfile=f.FullName;    
Console.WriteLine(f.Name);
Console.WriteLine("uploadfile"+uploadfile);
var client = new SftpClient(host, port, username, password);
client.Connect();
if(client.IsConnected){
       Console.WriteLine("I AM CONNECTED");
}
var fileStream = new FileStream(uploadfile, FileMode.Open);  
if(fileStream!=null){
            Console.WriteLine("YOU ARE NOT NULL");
}
client.BufferSize = 4 * 1024; 
client.UploadFile(fileStream, f.Name,null);
client.Disconnect();
client.Dispose();

I am able to connect and the filestream is also not NULL. But I am getting PermissionDeniedException while attempting to upload a file.

Unhandled Exception: Renci.SshNet.Common.SftpPermissionDeniedException: Permission denied
   at Renci.SshNet.Sftp.SftpSession.RequestOpen(String path, Flags flags, Boolean nullOnError)
   at Renci.SshNet.SftpClient.InternalUploadFile(Stream input, String path, Flags flags, SftpUploadAsyncResult asyncResult, Action`1 uploadCallback)
   at Renci.SshNet.SftpClient.UploadFile(Stream input, String path, Boolean canOverride, Action`1 uploadCallback)
   at Renci.SshNet.SftpClient.UploadFile(Stream input, String path, Action`1 uploadCallback)
   at movemsi.Program.UploadFile()
   at movemsi.Program.Main(String[] args)

Is there any settings I am missing from the above code. Any help is much appreciated.

Solution 1

You need to specify a full path to upload the file to.

For example:

client.UploadFile(fileStream, "/home/user/" + f.Name, null);

Without the path, the SFTP server probably tries to write the file to a root folder or other folder that you do not have a write access to (hence the Permission denied).

Solution 2

You can do this:

FileInfo f = new FileInfo("C:\\mdu\\abcd.xml");            
string uploadfile = f.FullName;    
Console.WriteLine(f.Name);
Console.WriteLine("uploadfile" + uploadfile);

//Passing the sftp host without the "sftp://"
var client = new SftpClient("ftp.example.com", port, username, password);
client.Connect();
if(client.IsConnected)
{
    var fileStream = new FileStream(uploadfile, FileMode.Open);  
    if(fileStream != null)
    {
        //If you have a folder located at sftp://ftp.example.com/share
        //then you can add this like:
        client.UploadFile(fileStream, "/share/" + f.Name,null);
        client.Disconnect();
        client.Dispose();
    }
}

Solution 3

I was getting this error because I was using Path.Combine() for my UploadFile argument, like this:

client.UploadFile(fileStream, Path.Combine("/home/user", f.Name), null);

I think it makes the slashes the wrong way around. So just do normal string concatenation like the answer above:

client.UploadFile(fileStream, "/home/user/" + f.Name, null);