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About a year ago I wrote about creating a HTTP tunnel through a HTTP proxy server using GNU HTTP Tunnel.   Unfortunately if the proxy server was run by a ISA server then GNU HTTP Tunnel would not work since it doesn’t support NTLM authentication.

BoutDuTunnel is an open source project written in C# and is compatible with HTTP proxy servers, even if they use NTLM authentication (like ISA Server) and even if they prohibit the “connect method”.

To setup BoutDuTunnel on Ubuntu I had to install Mono.  When using Mono 2.0.1 or 2.4 an error occurred Unexpected binary element: 21 when running the BdtClient.exe. Therefore I installed Mono 1.9.1 by building it from the source.

Instead of installing the latest version of BoutDuTunnel, I installed 1.4.3066 because an error would occur on the BoutDuTunnel server moments after the BoutDuTunnel client connected to it.

Unhandled Exception: System.MethodAccessException: Method `Bdt.Server.Service.TunnelSession:CheckTimeout (Bdt.Shared.Logs.ILogger)' is inaccessible from method `Bdt.Server.Service.TimeoutObject:CheckTimeout (Bdt.Shared.Logs.ILogger,System.Collections.Generic.Dictionary`2)'

Setting Up the HTTP Tunnel

Setting Up BdtServer (on the home computer)

The BdtServer can be setup through the command line or hosted inside Apache/mod_mono.  To setup BdtServer with the command line extract the BoutDuTunnel and modify the BdtServer configuration file.

$ unzip bdt.bin.1.4.3066.mono.zip
$ cd bdt.bin.1.4.3066.mono/BdtServer
$ nano BdtServerCfg.xml

The configuration file is well commented and should be similar to the following:

Configure binary stream/HTTP as the communication protocol to be used.

<service
name     = "BdtServer"
protocol = "Bdt.Shared.Protocol.HttpBinaryRemoting"
port     = "8080"
/>

Require user be authenticated before establishing a communication.

<users>
<username
enabled  = "true"
password = "password"
/>
</users>

To start up BdtServer execute the following:

$ cd bdt.bin.1.4.3066.mono/BdtServer/
$ mono BdtServer.exe

Setting Up BdtClient (on the office computer)

There are two types of client available for BoutDuTunnel:

• BdtClient run by the command line
• BdtGuiClient which provides a GUI interface

To setup BdtClient modify the BdtClientCfg.xml configuration file.

Configure hostname and communication protocol for server with BdtServer.

  <service
    name     = "BdtServer"
    protocol = "Bdt.Shared.Protocol.HttpBinaryRemoting"
    address  = "my.server"
    port     = "8080"
    username = "my.username"
    password = "my.password"
  />

Configure the proxy/ISA server to be used.

  <proxy
    enabled  = "true">
    <authentification
      auto     = "false"
      username = "proxy.username"
      password = "proxy.password"
      domain   = "proxy.domain"
    />
    <configuration
      auto     = "false"
      address  = "proxy.hostname"
      port     = "proxy.port"
    />
  </proxy>

Configure the ports to be forwarded.

  <forward>
    <port22
      shared  = "false"
      enabled = "true"
      address = "my.ssh.server"
      port    = "22"
    />
  </forward>

Run the BoutDuTunnel client to establish a tunnel connection to the BdtServer.

C:\bdt.bin.1.4.3066.mono\BdtClient>BdtClient

Now a SSH connection can be establish to your home computer by connecting through localhost:22

Related posts:

1. Installing BoutDuTunnel Server on Mono XSP
2. SSH through HTTP Proxies
3. Surfing the Web using SSH Tunnel
4. Integrating Tomcat and Apache Using Proxy
5. Apache mod_proxy and Reverse Proxy