Visual Basic 6.0

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.

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Visual Basic 6.0

Dim success As Long
success = 0

'  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 ChilkatSshTunnel

'  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 Long
sshPort = 22
success = tunnel.Connect("ssh.example.com",sshPort)
If (success = 0) Then
    Debug.Print 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
password = "mySshPassword"

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

success = tunnel.AuthenticateSecPw(secureLogin,securePassword)
If (success = 0) Then
    Debug.Print tunnel.LastErrorText
    Exit Sub
End If

Debug.Print "Authenticated with secure strings."

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

Dim waitForThreadExit As Long
waitForThreadExit = 1
success = tunnel.CloseTunnel(waitForThreadExit)
If (success = 0) Then
    Debug.Print tunnel.LastErrorText
    Exit Sub
End If