How to connect SFTP With Public Key and Private Key File with Passphrase through codebehind C# SharpSsh

Question

How can I set Public key File and Private key File with Pass-phrase. Also I need to accept the fingerprint sent by the connecting sftp. I am using Tamir.SharpSsh source. Is it possible to incorporate there in the source ? Please suggest.

Answer 1

I have successfully used the SSH.NET open source library to work with SFTP. You can see this gist for more code on creating a folder, uploading, etc.

This is the code to connect to SFTP with keyfile + passphrase.

    public void Connect(string host, int port, string user, string passPhrase, string privateKeyFilePath) {

        var keyFiles = new[] { new PrivateKeyFile(privateKeyFilePath, passPhrase) };

        var methods = new List<AuthenticationMethod>();
        methods.Add(new PasswordAuthenticationMethod(user, passPhrase));
        methods.Add(new PrivateKeyAuthenticationMethod(user, keyFiles));

        var con = new ConnectionInfo(host, port, user, methods.ToArray());
        var client = new SftpClient(con);
        client.Connect();

        // .....

        client.Disconnect();
    }

Private key file format

Please note that your private key file must be in OpenSSH format. If you open the key file in Notepad++ it must have "BEGIN RSA PRIVATE KEY" on the first line.

If not then convert your private key file to an OpenSSH format using puttygen.

1. Open the private key in puttygen
2. Go to the Conversions menu and choose Export OpenSSH Key.
3. Save that new key to a file and use it.