SSH connection to a database using a tunnel

Question

SSH connection to a database using a tunnel

Nelson Soares 0

I´m trying to connect to a postgres db through an ssh tunnel.

I´m using the following code:

But i´m allaways getting the error "Invalid private key". I´ve already using putty gen load key-> Export open ssh key but i got allaways the same key format and the same error (Invalid private key).

Can you please helP ??

the code above i´ve tryed. i hope to get the right key to connect correctly trough the tunnel

Nelson Soares 0

CODE

var key = "xxxxxx";

MemoryStream keyStream = new MemoryStream(Encoding.UTF8.GetBytes(key));

   Renci.SshNet.ConnectionInfo connn = new Renci.SshNet.ConnectionInfo(

       "xxx.xxx.xx.xx",


      

       "tml",

       new AuthenticationMethod[]

       {
```new PrivateKeyAuthenticationMethod("tml", new PrivateKeyFile[]

{

   new PrivateKeyFile(keyStream, ""),

}),

```typescript
       });

   SshClient client = new SshClient(connn);

   {

       client.Connect();

       if (!client.IsConnected)

       {

           // Display error

           Console.WriteLine("Client not connected!");

       }

       else

       {

           Console.WriteLine("Client connected!");

       }

       var port = new ForwardedPortLocal("10.5.10.43", 8080, "141.147.35.80", 22);

       client.AddForwardedPort(port);

       port.Start();

       using (var conn = new NpgsqlConnection("Server=10.5.10.43;Database=trino;Port=8080;User Id=admin;Password=;"))

       {

           conn.Open();

       }

       port.Stop();

       client.Disconnect();

   }

1 answer

Your answer

Nelson Soares 0 Reputation points

2025-04-03T15:37:52.7866667+00:00

CODE

var key = "xxxxxx";

MemoryStream keyStream = new MemoryStream(Encoding.UTF8.GetBytes(key));

Renci.SshNet.ConnectionInfo connn = new Renci.SshNet.ConnectionInfo( "xxx.xxx.xx.xx", "tml", new AuthenticationMethod[] { ```new PrivateKeyAuthenticationMethod("tml", new PrivateKeyFile[] { new PrivateKeyFile(keyStream, ""), }), ```typescript }); SshClient client = new SshClient(connn); { client.Connect(); if (!client.IsConnected) { // Display error Console.WriteLine("Client not connected!"); } else { Console.WriteLine("Client connected!"); } var port = new ForwardedPortLocal("10.5.10.43", 8080, "141.147.35.80", 22); client.AddForwardedPort(port); port.Start(); using (var conn = new NpgsqlConnection("Server=10.5.10.43;Database=trino;Port=8080;User Id=admin;Password=;")) { conn.Open(); } port.Stop(); client.Disconnect(); }

Answer 1

Anonymous

Hi @Nelson Soares ,

Please check the SSH.Net usage documentation. https://github.com/sshnet/SSH.NET

Renci.SshNet only supports OpenSSH format private keys, you seem to be using a public key. First you'd better test whether your key is correct. Run the OpenSSH ssh command in Windows (with OpenSSH), Mac or Linux terminal to see if the connection is successful or the reason for the error.

If the key is fine, modify it to the format supported by Renci.SshNet according to the documentation.

Best Regards,

Jiale

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Nelson Soares 0 Reputation points

2025-04-04T11:03:30.2633333+00:00

So, I´m using an windows computer, and i´m trying to connect to a database using an SSH tunnel.

The key file was given to me by the IT department in my department.

So I opened the windows command line and I run:

ssh -N -i C:\Users\NelsonSoares\Documents\Trino*tml_rsa_prod2.key* tml@141.147.35.80 -L 38085:10.5.10.43:8080

And i can sucessfully connect through the tunnel. But, when I use the key (tml_rsa_prod2.key) in my C# code , I get the error "INVALID OPENSSH KEY".

I tried to convert to RSA key format and i use the file with an RSA format, however I get the error: Permission Denied : Public Key .

The error appears in the line client.Connect();

Can you please help?

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SSH connection to a database using a tunnel

1 answer

Your answer