SSH Tunnel using an HTTP proxy

Demonstrates how to establish an SSH tunnel that uses an HTTP proxy.

CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @sshTunnel int
    EXEC @hr = sp_OACreate 'Chilkat.SshTunnel', @sshTunnel OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @success int

    EXEC sp_OAMethod @sshTunnel, 'UnlockComponent', @success OUT, '30-day trial'
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @sshTunnel, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  The DestHostname / DestPort is the server with which we
    --  are ultimately communicating.
    EXEC sp_OASetProperty @sshTunnel, 'DestPort', 1433
    EXEC sp_OASetProperty @sshTunnel, 'DestHostname', 'myServer.com'

    --  Provide information about the location of the SSH server,
    --  and the authentication to be used with it. This is the
    --  login information for the SSH server.
    EXEC sp_OASetProperty @sshTunnel, 'SshHostname', '192.168.1.108'
    EXEC sp_OASetProperty @sshTunnel, 'SshPort', 22
    EXEC sp_OASetProperty @sshTunnel, 'SshLogin', 'mySshLogin'
    EXEC sp_OASetProperty @sshTunnel, 'SshPassword', 'mySshPassword'

    --  To connect through an HTTP proxy, set the HttpProxyHostname
    --  and HttpProxyPort properties to the hostname (or IP address)
    --  and port of the HTTP proxy.  Typical port numbers used by
    --  HTTP proxy servers are 3128 and 8080.
    EXEC sp_OASetProperty @sshTunnel, 'HttpProxyHostname', 'www.my-http-proxy.com'
    EXEC sp_OASetProperty @sshTunnel, 'HttpProxyPort', 3128

    --  Important:  Your HTTP proxy server must allow non-HTTP
    --  traffic to pass.  Otherwise this does not work.

    --  Start accepting connections in a background thread.
    --  The SSH tunnels are autonomously run in a background
    --  thread.  There is one background thread for accepting
    --  connections, and another for managing the tunnel pool.
    DECLARE @listenPort int

    SELECT @listenPort = 3316
    EXEC sp_OAMethod @sshTunnel, 'BeginAccepting', @success OUT, @listenPort
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @sshTunnel, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    --  At this point you may write code to communicate with
    --  the server at DestHostname/DestPort.  This could be anything --
    --  it could be WinSock, ADO/ODBC code, Chilkat Socket, etc.
    --  However, instead of connecting directly to DestHostname/DestPort,
    --  your code would connect to localhost:3316 (because this
    --  is the listenPort of the SSH Tunnel

    --  This is what happens when you connect to localhost:3316
    --  1) The connection is accepted by the SSH tunnel
    --      background thread (which was started in the call to BeginAccepting).
    --  2) In the background thread, a connection to a remote SSH
    --      server is established via an HTTP proxy.
    --  3) Port-forwarding is setup so that the remote SSH server connects
    --     to the DestHostname/DestPort.
    --  4) Data sent by your application to localhost:3316 is ultimately forwarded to DestHostname/DestPort
    --   5) Data sent back from DestHostname/DestPort is forwarded back and received by your application

    --  When you're finished with the  connection, you may
    --  stop the background tunnel threads:
    --  Stop the background thread that accepts new connections:
    EXEC sp_OAMethod @sshTunnel, 'StopAccepting', @success OUT
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @sshTunnel, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END
    --  If any background tunnels are still in existence (and managed
    --  by a single SSH tunnel pool background thread), stop them...
    DECLARE @maxWaitMs int

    SELECT @maxWaitMs = 1000
    EXEC sp_OAMethod @sshTunnel, 'StopAllTunnels', @success OUT, @maxWaitMs
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @sshTunnel, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END
END
GO