PolarProxy in Podman

Podman is a daemonless Linux container engine, which can be used as a more secure alternative to Docker. This blog post demonstrates how to run PolarProxy in a rootless container using Podman. If you still prefer to run PolarProxy in Docker, then please read our blog post "PolarProxy in Docker" instead.

Install Podman and fuse-overlayfs

Install Podman according to the official Podman installation instructions. Then install fuse-overlayfs, which is an overlay file system for rootless containers. Fuse-overlayfs can be installed in Debian/Ubuntu with "sudo apt install fuse-overlayfs" and in CentOS with "sudo yum install fuse-overlayfs".

Create a Podman Image for PolarProxy

Create a Dockerfile with the following contents:

Save the Docker file as "Dockerfile" (no extension) in an empty directory and start a shell in that directory. Build a PolarProxy Podman image with:

Test the PolarProxy Podman Image

Take the polarproxy Podman image for a test run. Start it with:

Establish an HTTPS connection through PolarProxy by running this curl command from another shell on the same machine:

If everything works alright, then curl should output HTML and the interactive Podman session running the polarproxy image should print something like:

<6>[10443] 127.0.0.1 -> N/A Connection from: 127.0.0.1:44122
<6>[10443] 127.0.0.1 -> www.netresec.com Connection request for: www.netresec.com from 127.0.0.1:44122
<6>[10443] 127.0.0.1 -> www.netresec.com Action: DECRYPT

Create a Podman Container for PolarProxy

Create directories "pcap" and "polarproxy", where PolarProxy should store the decrypted network traffic and its root CA certificate.

Create a container called "polarproxy", which has the "pcap" and "polarproxy" directories mounted as volumes. The service on TCP 10080 will serve the proxy's public root cert over HTTP. The localhost:57012 service is a Pcap-over-IP server, from which the decrypted network traffic can be streamed in real-time.

Create and enable a systemd user service that will run the container.

Start the systemd user service to activate the PolarProxy container.

Verify that the service is running and that you can view the logs from PolarProxy.

Expose PolarProxy to the Network

Try making an HTTPS connection via PolarProxy from another PC on the network.

Don't forget to save the firewall redirect rule if it is working as desired!

Redirect HTTPS and Trust the Root CA

You can now redirect outgoing TCP 443 traffic from your network to your Podman/PolarProxy host. Review the "Routing HTTPS Traffic to the Proxy" section on the PolarProxy page for recommendations on how to redirect outgoing traffic to PolarProxy.

Finally, configure the operating system, browsers and other applications that will get their TLS traffic proxied by PolarProxy to trust the root CA of the PolarProxy service running in your Podman container. Follow the steps in the "Trusting the PolarProxy root CA" section of the PolarProxy documentation in order to install the root cert.

Accessing Decrypted TLS Traffic

You should be able to access PCAP files with the decrypted HTTPS traffic in the "pcap" directory.

It is also possible view the decrypted traffic in real-time by using netcat and tcpdump as a Pcap-over-IP client like this:

It probably makes more sense to forward the decrypted traffic to an IDS or other type of network security monitoring tool though. See our blog posts "Sniffing Decrypted TLS Traffic with Security Onion" and "Capturing Decrypted TLS Traffic with Arkime" for instructions on how to forward the decrypted network traffic to a network monitoring solution like Security Onion or Arkime.

PolarProxy in Podman on ARM Linux

PolarProxy can also run on ARM Linux installations, such as a Raspberry Pi. However, the Dockerfile must be modified slightly in order to do so.

Don't know if you're running a 32-bit or 64-bit OS? Run "uname -m" and check if the output says "armv7*" (arm32) or "armv8*" (arm64).

See our blog post "Raspberry PI WiFi Access Point with TLS Inspection" for more details about deploying PolarProxy on a Raspberry Pi.

ʕ•ᴥ•ʔ + 🦭 = 💜

Posted by Erik Hjelmvik on Tuesday, 27 October 2020 18:33:00 (UTC/GMT)

Tags: #PolarProxy​ #Docker​ #TLS​ #HTTPS​ #Proxy​ #curl​ #PCAP​ #Dockerfile​ #DNAT​ #container​ #arm32​ #arm64​ #AArch64​ #PCAP-over-IP​ #pcapoverip​ #systemctl​ #systemd​

PolarProxy in Docker

Our transparent TLS proxy PolarProxy is gaining lots of popularity due to how effective it is at generating decrypted PCAP files in combination with how easy it is to deploy. In this blog post we will show how to run PolarProxy in Docker.

Installation Instructions

Create a Dockerfile with the following contents:

Save the Docker file as "Dockerfile" (no extension) in an empty directory and start a shell in that directory with root privileges. Build the PolarProxy Docker image with:

Next, create a Docker container named "polarproxy":

It is now time to start the polarproxy container:

Verify that PolarProxy is running:

Try fetching PolarProxy's public root CA certificate with curl and then connect to a website over HTTPS through the proxy:

Redirect HTTPS and Trust the Root CA

You can now redirect outgoing TCP 443 traffic from your network to your Docker host. Review the "Routing HTTPS Traffic to the Proxy" section on the PolarProxy page for recommendations on how to redirect outgoing traffic to PolarProxy.

Finally, configure the operating system, browsers and other applications that will get their TLS traffic proxied by PolarProxy to trust the root CA of the PolarProxy service running in your Docker container. Follow the steps in the "Trusting the PolarProxy root CA" section of the PolarProxy documentation in order to install the root cert.

Docker Volumes

The Docker file we used in this blog post defines two volumes. The first volume is mounted on "/var/log/PolarProxy" in the container, which is where the decrypted network traffic will be stored as hourly rotated PCAP files. The second volume is the polarproxy home directory, under which PolarProxy will store its private root CA certificate.

The volumes are typically located under "/var/lib/docker/volumes" on the Docker host's file system. You can find the exact path by running:

Or use find to list *.pcap files in the Docker volumes directory:

The full path of your private PolarProxy Root CA certificate, which is located under "/home/polarproxy/" in the Docker container, can also be located using find:

We recommend reusing the "/home/polarproxy/" volume, when deploying new PolarProxy instances or upgrading to a new version of PolarProxy, in order to avoid having to re-configure clients to trust a new root CA every time a new PolarProxy container is created.

PolarProxy in Docker on ARM Linux

PolarProxy can also run on ARM Linux installations, such as a Raspberry Pi. However, the Dockerfile must be modified slightly in order to do so.

Don't know if you're running a 32-bit or 64-bit OS? Run "uname -m" and check if the output says "armv7*" (arm32) or "armv8*" (arm64).

See our blog post "Raspberry PI WiFi Access Point with TLS Inspection" for more details about deploying PolarProxy on a Raspberry Pi (without Docker).

Credits

We'd like to thank Jonas Lejon for contacting us back in February about the work he had done to get PolarProxy running in Docker. We used Jonas' work as a starting point when building the installation instructions in this how-to guide.

We also want to thank Erik Ahlström for providing valuable feedback on the instructions in this guide.

ʕ•ᴥ•ʔ + 🐳 = 💜

Posted by Erik Hjelmvik on Wednesday, 07 October 2020 08:09:00 (UTC/GMT)

Tags: #PolarProxy​ #Docker​ #TLS​ #HTTPS​ #Proxy​ #TLSI​ #Dockerfile​ #curl​ #x509​ #X.509​ #PCAP​ #DNAT​ #container​ #DNAT​ #arm32​ #arm64​ #AArch64​ #PCAP-over-IP​ #pcapoverip​