DataFlex

SSH Tunnel Through an Outbound SOCKS Proxy

Demonstrates reaching the SSH server through an outbound SOCKS proxy using the SocksVersion, SocksHostname, SocksPort, SocksUsername, and SocksPassword properties.

Background: This is the reverse direction from dynamic forwarding: here a SOCKS proxy is used to reach the SSH server, for networks where outbound connections must pass through one. SocksVersion is the switch — 0 means no SOCKS, while 4 or 5 selects the protocol. SOCKS5 supports username/password authentication and remote DNS; SOCKS4 supports only a username.

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DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoTunnel
    Integer iSshPort
    String sPassword
    Integer iListenPort
    Boolean iWaitForThreadExit
    String sTemp1

    Move False To iSuccess

    //  Demonstrates reaching the SSH server through an outbound SOCKS proxy using the SshTunnel
    //  properties SocksVersion, SocksHostname, SocksPort, SocksUsername, and SocksPassword.

    Get Create (RefClass(cComChilkatSshTunnel)) To hoTunnel
    If (Not(IsComObjectCreated(hoTunnel))) Begin
        Send CreateComObject of hoTunnel
    End

    //  Set SocksVersion to 4 or 5 to route the outbound connection to the SSH server through a SOCKS
    //  proxy.  A value of 0 (the default) means no SOCKS proxy.
    Set ComSocksVersion Of hoTunnel To 5
    Set ComSocksHostname Of hoTunnel To "socks.example.com"
    Set ComSocksPort Of hoTunnel To 1080

    //  SOCKS4 supports only a username; SOCKS5 supports username and password.
    Set ComSocksUsername Of hoTunnel To "myProxyLogin"
    Set ComSocksPassword Of hoTunnel To "myProxyPassword"

    Set ComDestHostname Of hoTunnel To "db.internal.example.com"
    Set ComDestPort Of hoTunnel To 5432

    //  Connect to the SSH server through the SOCKS proxy configured above.
    Move 22 To iSshPort
    Get ComConnect Of hoTunnel "ssh.example.com" iSshPort To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoTunnel To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  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.
    Move "mySshPassword" To sPassword

    Get ComAuthenticatePw Of hoTunnel "mySshLogin" sPassword To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoTunnel To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Move 1080 To iListenPort
    Get ComBeginAccepting Of hoTunnel iListenPort To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoTunnel To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Tunnel established through the SOCKS proxy."

    Move True To iWaitForThreadExit
    Get ComCloseTunnel Of hoTunnel iWaitForThreadExit To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoTunnel To sTemp1
        Showln sTemp1
        Procedure_Return
    End



End_Procedure