VB.NET

SSH Through a SOCKS Proxy

Demonstrates connecting to an SSH server through a SOCKS4 or SOCKS5 proxy. Set the SOCKS properties before calling Connect, and set SocksVersion to match the proxy server.

Background: SOCKS is a general-purpose TCP relay, so unlike an HTTP proxy it is designed from the start to carry arbitrary protocols — usually the smoother option for SSH. The version matters: SOCKS4 supports only a username with no password, while SOCKS5 supports full login/password authentication as well as IPv6 and remote DNS resolution. Note this is the inverse of dynamic port forwarding: here a SOCKS proxy is used to reach the SSH server, rather than SSH providing a SOCKS proxy.

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Dim success As Boolean = False

'  This example requires the Chilkat API to have been previously unlocked.
'  See Global Unlock Sample for sample code.

'  Demonstrates connecting to an SSH server through a SOCKS4 or SOCKS5 proxy.

Dim ssh As New Chilkat.Ssh

'  Set the SOCKS proxy properties before connecting.  The hostname may be a domain name or an
'  IP address.
ssh.SocksHostname = "socks.example.com"
ssh.SocksPort = 1080
ssh.SocksUsername = "mySocksLogin"
ssh.SocksPassword = "mySocksPassword"

'  Set the version to match the proxy server: 4 or 5.
'  Note: SOCKS4 supports only a username, with no password.  SOCKS5 supports full
'  login/password authentication.
ssh.SocksVersion = 5

Dim hostname As String = "ssh.example.com"
Dim port As Integer = 22
success = ssh.Connect(hostname,port)
If (success = False) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


Debug.WriteLine("Connected to the SSH server through the SOCKS proxy.")

'  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"

success = ssh.AuthenticatePw("mySshLogin",password)
If (success = False) Then
    Debug.WriteLine(ssh.LastErrorText)
    Exit Sub
End If


'  ... use the SSH connection normally ...

ssh.Disconnect()