From 982508d30f887b4fe8b2a855792ae1e33f378222 Mon Sep 17 00:00:00 2001 From: Aldo Cortesi Date: Thu, 22 Feb 2018 17:21:34 +1300 Subject: All new documentation This patch does a lot. - Ditch sphinx in favor of hugo. This gives us complete control of the layout and presentation of our docs. Henceforth, docs will be hosted on our website rather than ReadTheDocs. - Create a simple, clean doc layout and theme. - Remove large parts of the documentaion. I've ditched anything that was a) woefully out of date, b) too detailed, or c) too hard to maintain in the long term. - Huge updates to the docs themselves: completely rewrite addons documentation, add docs for core concepts like commands and options, and revise and tweak a lot of the existing docs. With this patch, we're also changing the way we publish and maintain the docs. From now on, we don't publish docs for every release. Instead, the website will contain ONE set of docs for each major release. The online docs will be updated if needed as minor releases are made. Docs are free to improve during minor releases, but anything that changes behaviour sufficiently to require a doc change warrants a new major release. This also leaves us free to progressively update and improve docs out of step with our release cadence. With this new scheme, I feel CI over the docs is less important. I've removed it for now, but won't object if someone wants to add it back in. --- docs/src/content/howto-transparent-vms.md | 114 ++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) create mode 100644 docs/src/content/howto-transparent-vms.md (limited to 'docs/src/content/howto-transparent-vms.md') diff --git a/docs/src/content/howto-transparent-vms.md b/docs/src/content/howto-transparent-vms.md new file mode 100644 index 00000000..b186fd39 --- /dev/null +++ b/docs/src/content/howto-transparent-vms.md @@ -0,0 +1,114 @@ +--- +title: "Transparently Proxying VMs" +menu: + howto: + weight: 3 +--- + +# Transparently proxify virtual machines + +This walkthrough illustrates how to set up transparent proxying with +mitmproxy. We use VirtualBox VMs with an Ubuntu proxy machine in this +example, but the general *Internet \<--\> Proxy VM \<--\> (Virtual) +Internal Network* setup can be applied to other setups. + +## 1. Configure Proxy VM + +On the proxy machine, **eth0** is connected to the internet. **eth1** is +connected to the internal network that will be proxified and configured +to use a static ip (192.168.3.1). + +### VirtualBox configuration + + +{{< figure src="/transparent-vms/step1_vbox_eth0.png" >}} + +{{< figure src="/transparent-vms/step1_vbox_eth1.png" >}} + + +### VM Network Configuration + +{{< figure src="/transparent-vms/step1_proxy.png" >}} + +## 2. Configure DHCP and DNS + +We use dnsmasq to provide DHCP and DNS in our internal network. Dnsmasq is a +lightweight server designed to provide DNS (and optionally DHCP and TFTP) +services to a small-scale network. Before we get to that, we need to fix some +Ubuntu quirks: **Ubuntu \>12.04** runs an internal dnsmasq instance (listening +on loopback only) by default +[\[1\]](https://www.stgraber.org/2012/02/24/dns-in-ubuntu-12-04/). For our use +case, this needs to be disabled by changing `dns=dnsmasq` to `#dns=dnsmasq` in +**/etc/NetworkManager/NetworkManager.conf** and if on Ubuntu 16.04 or newer +running: + +{{< highlight bash >}} +sudo systemctl restart NetworkManager +{{< / highlight >}} + +If on Ubuntu 12.04 or 14.04 running: + +{{< highlight bash >}} +sudo restart network-manager +{{< / highlight >}} + +afterwards. + +Now, dnsmasq can be be installed and configured: + +{{< highlight bash >}} +sudo apt-get install dnsmasq +{{< / highlight >}} + +Replace **/etc/dnsmasq.conf** with the following configuration: + +{{< highlight none >}} +# Listen for DNS requests on the internal network +interface=eth1 +# Act as a DHCP server, assign IP addresses to clients +dhcp-range=192.168.3.10,192.168.3.100,96h +# Broadcast gateway and dns server information +dhcp-option=option:router,192.168.3.1 +dhcp-option=option:dns-server,192.168.3.1 +{{< / highlight >}} + +Apply changes: + +If on Ubuntu 16.04 or newer: + +{{< highlight bash >}} +sudo systemctl restart dnsmasq +{{< / highlight >}} + +If on Ubuntu 12.04 or 14.04: + +{{< highlight bash >}} +sudo service dnsmasq restart +{{< / highlight >}} + +Your **proxied machine** in the internal virtual network should now receive an +IP address via DHCP: + +{{< figure src="/transparent-vms/step2_proxied_vm.png" >}} + +## 3. Redirect traffic to mitmproxy + +To redirect traffic to mitmproxy, we need to add two iptables +rules: + +{{< highlight bash >}} +sudo iptables -t nat -A PREROUTING -i eth1 -p tcp --dport 80 -j REDIRECT --to-port 8080 +sudo iptables -t nat -A PREROUTING -i eth1 -p tcp --dport 443 -j REDIRECT --to-port 8080 +{{< / highlight >}} + +## 4. Run mitmproxy + +Finally, we can run mitmproxy in transparent mode with + +{{< highlight bash >}} +mitmproxy -T +{{< / highlight >}} + +The proxied machine cannot to leak any data outside of HTTP or DNS requests. If +required, you can now [install the mitmproxy certificates on the proxied +machine]({{< relref "concepts-certificates" >}}). -- cgit v1.2.3