VB.NET

SSH Tunnel Authenticate with a SecureString Password

Demonstrates the Chilkat SshTunnel.AuthenticateSecPw method, which authenticates using SecureString login and password objects. The first argument is the login and the second is the password.

Background: Because a tunnel process is long-lived and holds its SSH credentials for its entire lifetime, protecting them in memory is worthwhile. A SecureString keeps the value encrypted under a randomly generated session key. Populate it from a value obtained at runtime rather than a hard-coded literal.

Chilkat VB.NET Downloads

Download Chilkat for VB.NET

VB.NET

Dim success As Boolean = False

'  Demonstrates the SshTunnel.AuthenticateSecPw method, which authenticates using SecureString
'  login and password objects.  The 1st argument is the login and the 2nd is the password.

Dim tunnel As New Chilkat.SshTunnel

'  The tunnel forwards accepted local connections to this destination through the SSH server.
tunnel.DestHostname = "db.internal.example.com"
tunnel.DestPort = 5432

'  Connect to the SSH server.  This performs the TCP/proxy connection and SSH handshake, but
'  does not authenticate yet.
Dim sshPort As Integer = 22
success = tunnel.Connect("ssh.example.com",sshPort)
If (success = False) Then
    Debug.WriteLine(tunnel.LastErrorText)
    Exit Sub
End If


'  Normally you would not hard-code the password in source.  You should instead obtain it
'  from an interactive prompt, environment variable, or a secrets vault.
Dim password As String = "mySshPassword"

'  Place the login and password into SecureString objects.
Dim secureLogin As New Chilkat.SecureString
secureLogin.Append("mySshLogin")
Dim securePassword As New Chilkat.SecureString
securePassword.Append(password)

success = tunnel.AuthenticateSecPw(secureLogin,securePassword)
If (success = False) Then
    Debug.WriteLine(tunnel.LastErrorText)
    Exit Sub
End If

Debug.WriteLine("Authenticated with secure strings.")

'  After authenticating, call BeginAccepting to start listening for local connections to forward.

Dim waitForThreadExit As Boolean = True
success = tunnel.CloseTunnel(waitForThreadExit)
If (success = False) Then
    Debug.WriteLine(tunnel.LastErrorText)
    Exit Sub
End If