Mistborn

A secure platform for easily standing up and managing your own cloud services: including firewall, ad-blocking, and multi-factor WireGuard VPN access

WireGuard Management in Mistborn

As featured in Linux Magazine (Linux Pro Magazine in North America) in November 2020

Table of Contents

[[TOC]]

What is Mistborn

The term Mistborn is inspired by Brandon Sanderson's Cosmere.

Mistborn started as a passion project for a husband and father protecting his family. Certain family members insisted on connecting their devices to free public WiFi networks. We needed a way to secure all family devices with a solid VPN (WireGuard). Once we had that we wanted to control DNS to block ads to all devices and block malicious websites across all family devices. Then we wanted chat, file-sharing, and webchat services that we could use for ourselves without entrusting our data to some big tech company. And then... home automation. I know I'll be adding more services so I made that easy to do.

As a Certified Information Systems Security Professional (CISSP) and an Offensive Security Certified Professional (OSCP), I designed Mistborn thinking about how it would be attacked by both external and internal threats. In making design trade-off decisions I tend to the paranoid. See Technical and Security Insights.

Ideal for teams who:

• hate internet ads
• need to be protected from malicious internet domains
• need to collaborate securely
• need multi-factor authentication for WireGuard
• want to retain sole ownership of their data
• want to easily grant and revoke access to people and devices via a simple web interface
• want secure internet access wherever they are
• want to limit or stop data collecting services
• want to prevent being detected/blocked for using a proxy or VPN service

See the Mistborn Network Security wiki page to see the network scan results for Mistborn.

Mistborn depends on these core open source technologies:

• Docker: containerization
• WireGuard: secure VPN access
• SSH: secure remote management

These tools are not vital to Mistborn itself but are integrated to enhance security, ease, and features:

• iptables: The powerful Linux netfilter firewall tool
• cockpit: A Graphical User Interface for system management, including container management
• Pi-hole: A DNS server for network-wide ad blocking, etc
• DNScrypt: prevents DNS spoofing via cryptographic signatures to verify that responses originate from the chosen DNS resolver and haven't been tampered
• Traefik: A modern, efficient reverse-proxy

These tools can be turned on from the Mistborn Security Operations Center:

• Wazuh: Wazuh is a free, open source and enterprise-ready security monitoring solution for threat detection, integrity monitoring, incident response and compliance.
• Suricata: Suricata is a free and open source, mature, fast and robust network threat detection engine. The Suricata engine is capable of real time intrusion detection (IDS), inline intrusion prevention (IPS), network security monitoring (NSM) and offline pcap processing. Suricata inspects the network traffic using a powerful and extensive rules and signature language, and has powerful Lua scripting support for detection of complex threats.

Within Mistborn is a panel to enable and manage these free extra services (off by default), locally hosted in Docker containers:

• Home Assistant: Open source home automation that puts local control and privacy first
• Nextcloud: Nextcloud offers the industry-leading, on-premises content collaboration platform. It combines the convenience and ease of use of consumer-grade solutions like Dropbox and Google Drive with the security, privacy and control business needs.
• Vaultwarden: Password manager. An unofficial Bitwarden server implementation written in Rust. It is compatible with the official Bitwarden clients, and is ideal for self-hosted deployments where running the official resource-heavy service is undesirable.
• Syncthing: Syncthing is a continuous file synchronization program. It synchronizes files between two or more computers in real time, safely protected from prying eyes.
• OnlyOffice: Cloud office suite. ONLYOFFICE provides you with the most secure way to create, edit and collaborate on business documents online.
• Rocket.Chat: Free, Open Source, Enterprise Team Chat.
• Jellyfin: The Free Media Software System.
• Tor: The Onion Router. One tool in the arsenal of online security and privacy.
• Jitsi: Multi-platform open-source video conferencing
• Guacamole: A clientless remote desktop gateway that supports standard protocols like VNC, RDP, and SSH.
• RaspAP: The easiest, full-featured wireless router setup for Debian-based devices. Period. (Mistborn integration in alpha testing).

Quickstart

Tested Operating Systems (in order of thoroughness):

• Debian 12 (Bookworm)

Formerly supported Operating Systems (your mileage may vary):

• Ubuntu 20.04 LTS
• Ubuntu 22.04 LTS
• Debian 11 (Bullseye)
• Raspberry Pi OS (formerly Raspbian) Buster
• Ubuntu 18.04 LTS
• Debian 10 (Buster)

Note: Install operating system updates and restart. Raspberry Pi OS particularly needs to be restarted after kernel updates (kernel modules for the currently running kernel may be missing).

Tested Browsers:

• Firefox

The default tests are run on DigitalOcean Droplets: 2GB RAM, 1 CPU, 50GB hard disk.

The Mistborn docker images exist for these architectures:

Mistborn Docker Images (hub.docker.com)	Architectures
mistborn (django, celery{worker,beat})	amd64, arm64, arm/v7
dnscrypt-proxy	amd64, arm64, arm/v7

Recommended System Specifications:

Use Case	Description	RAM	Hard Disk
Bare bones	WireGuard, Pihole (no Cockpit, no extra services)	2 GB	15 GB
Default	Bare bones + Cockpit	2 GB+	15 GB
Low-resource services	Default + Vaultwarden, Tor, Syncthing	4 GB	20 GB
High-resource services	Default + Jitsi, Nextcloud, Jellyfin, Rocket.Chat, Home Assistant, OnlyOffice	6 GB+	25 GB+
SIEM	Default + Wazuh + Extras	16 GB+	100 GB+

One line direct installation

wget -O install.sh https://gitlab.com/cyber5k/mistborn/-/raw/master/scripts/install.sh && sudo -E bash ./install.sh

OR

Clone repository and examine files first

git clone https://gitlab.com/cyber5k/mistborn.git
# Examine files if desired
sudo -E bash ./mistborn/scripts/install.sh

Get default admin WireGuard profile wait 1 minute after "Mistborn Installed" message

sudo mistborn-cli getconf 

Connect via WireGuard then visit http://home.mistborn

For more information, see the Installation section below.

Network Diagram

Mistborn protects your data in a variety of ways:

• All of your devices are protected wherever they go with the WireGuard VPN protocol
• The Mistborn firewall blocks unsolicited incoming internet packets
• Pi-hole running on Mistborn blocks outgoing internet requests to configurable blocked domains (ads, malicious/phishing domains, etc.)

See the Mistborn Network Security wiki page to see more network diagrams and the network scan results for Mistborn.

Status

The home page receives WireGuard status updates from the server via WebSocket connections. Superusers receive detailed updates about all connections and profiles. Regular users see details about their own devices.

Security Information & Event Management (SIEM)

The Mistborn Security Operations Center provides SIEM services with Wazuh. The Wazuh Manager requires an Open Distro for Elasticsearch backend. When the Mistborn host has >8 GB RAM the provided Elasticsearch backend can be used. Just click "Start Wazuh" on the Security Center page and enjoy your Enterprise-grade SIEM. Wazuh agents can be installed on just about any OS and all Wazuh agent traffic is communicated over the WireGuard connections. Instructions for adding endpoint agents can be found within Wazuh itself.

Mistborn's Wazuh installs and integrates with Suricata running on Mistborn with logs ingested into Wazuh.

The Wazuh Kibana plugin leverages the power of Elasticsearch:

Coppercloud

Pihole provides a way to block outgoing DNS requests for given lists of blocked domains. Coppercloud provides a way to block outgoing network calls of all types to given lists of IP addresses (IPv4 only for now). This is especially useful for blocking outgoing telemetry (data and state sharing) to owners of software running on all of your devices.

This example shows Coppercloud blocking a list of Microsoft IP addresses on a network with Windows 10 clients.

Gateways [deprecated]

Gateways have been deprecated in Mistborn 2+

Note: Since in Mistborn 2+ a single (or few) WireGuard ports are exposed, simple router port-forwarding enables the same features formerly allowed by Gateways.

Former documentation:

We were getting frustrated at being forced to choose between being connected to our VPN and using streaming services that we have paid for.

Netflix blocking my connections that it sees coming from a DigitalOcean droplet

In Mistborn, Gateways are upstream from the VPN server so connections to third-party services (e.g. Netflix, Hulu, etc.) will appear to be coming from the public IP address of the Gateway. I setup a Gateway at home (Raspberry Pi with wireguard and openresolv installed) and with our Mistborn on DigitalOcean, all WireGuard profiles created with this Gateway will appear to be coming from my house and are not blocked. No port-forwarding required (assuming Mistborn is publicly accessible).

The Gateway adds an extra network hop. DNS is still resolved in Mistborn so pihole is still blocking ads.

Remote Desktop

Remote desktops enable multiple users to share desktop resources and data. Remote desktops also enable groups to prevent sensitive data from ever entering an endpoint devices such as a smartphone. For reference, some United States Government regulations require controls to protect Controlled Unclassified Information (CUI) that are not feasible to implement on all endpoint devices and remote desktops prevent the data from entering the device (see NIST SP 800-171 3.1.19, CMMC AC.3.022).

Mistborn enables remote desktop access via the Apache Guacamole extra service, which supports VNC, RDP, SSH, and other protocols.

Guacamole implements its own users and groups access controls to manage access to individual desktops. All Mistborn users must be authenticated with Mistborn (via WireGuard only or MFA) to access the Guacamole interface.

Client to client communication

By default direct communication between network clients is blocked. Mistborn clients can all talk to Mistborn and communicate via shared services (Jitsi, Nextcloud, etc). Direct client to client communication can be enabled via the "client-to-client" toggle.

Installation

Mistborn is regularly tested on Ubuntu 20.04 LTS (DigitalOcean droplet with 2 GB RAM). It has also been successfully used on Debian Buster and Raspbian Buster systems (though not regularly tested). Make sure to install OS updates and restart before installing Mistborn (WireGuard installs differently on recent kernels).

Clone the git repository and run the install script:

git clone https://gitlab.com/cyber5k/mistborn.git
sudo -E bash ./mistborn/scripts/install.sh

Running install.sh will do the following:

• create a mistborn system user
• clone the mistborn repo to /opt/mistborn
• setup iptables and ip6tables rules and chains
• install iptables-persistent
• install Docker
• install OpenSSH
• install WireGuard
• install Cockpit (optional)
• create a cockpit system user (if Cockpit is installed)
• configure unattended-upgrades
• generate a self-signed TLS certificate/key (WebRTC functionality requires TLS)
• create and populate traefik.toml
• create /opt/mistborn_volumes and setup folders for services that will be mounted within
• backup original contents of /opt/mistborn_volumes in /opt/mistborn_backup
• Pull docker images for base.yml
• Build docker images for base.yml
• Disable competing DNS services (systemd-resolved and dnsmasq)
• copy Mistborn systemd service files to /etc/systemd/system
• start and enable Mistborn-base

Non-Interactive Installation

In order to install without interaction some environment variables need to be pre-set.

Environment Variables

See the environment variables needed in ./scripts/noninteractive/.install_barebones

Example Noninteractive Install

This will perform a noninteractive install with the default environment variables set in .install_barebones.

git clone https://gitlab.com/cyber5k/mistborn.git
sudo -E bash -c "source ./mistborn/scripts/noninteractive/.install_barebones && ./mistborn/scripts/install.sh"

Post-Installation

When Mistborn-base starts up it will create volumes, initialize the PostgreSQL database, start pihole, run Django migrations and then check to see if a Mistborn superuser named admin exists yet. If not, it will create the superuser admin along with an accompanying default WireGuard configuration file and start the WireGuard service. You can watch all of this happen with:

sudo journalctl -xfu Mistborn-base

The default WireGuard configuration file for admin may be obtained via:

sudo mistborn-cli getconf 

Please notice that the following lines are NOT part of the WireGuard config:

Starting mistborn_production_postgres ... done
Starting mistborn_production_redis    ... done
PostgreSQL is available

The WireGuard config will look like this:

# "10.15.91.2" - WireGuard Client Profile
[Interface]
Address = 10.15.91.2/32
# The use of DNS below effectively expands to:
#   PostUp = echo nameserver 10.15.91.1 | resolvconf -a tun.%i -m 0 -x
#   PostDown = resolvconf -d tun.%i
# If the use of resolvconf is not desirable, simply remove the DNS line
# and use a variant of the PostUp/PostDown lines above.
# The IP address of the DNS server that is available via the encrypted
# WireGuard interface is 10.15.91.1.
DNS = 10.15.91.1
PrivateKey = cPPflVGsxVFw2/lMmhiFTXMmH345bGqoqArD/NgjiXU=

[Peer]
PublicKey = DfIV1urYZXqXKiU4rOSfO0Iu589pEO+59dHV5w5N0mU=
PresharedKey = Z1SO5NuAnZ7JhzVCuUnYOQLWOQYmMoqG0pG1SNXUlh0=
AllowedIPs = 0.0.0.0/0,::/0
Endpoint = <Mistborn public IP address>:39207

Login via WireGuard

Install wireguard on your computer. If you get a resolvconf: command not found error when starting WireGuard then install openresolv: sudo apt-get install -y openresolv

• Copy the text of the default admin WireGuard config to /etc/wireguard/wg_admin.conf on your computer
• Run sudo systemctl start wg-quick@wg_admin
• Run sudo systemctl enable wg-quick@wg_admin
• Open your browser and go to "http://home.mistborn"
• Browse your Mistborn system!
  Note: The home.mistborn server takes a minute to come up after Mistborn is up (collectstatic on all that frontend JavaScript and CSS)

WireGuard Management

Mistborn users can be added (non-privileged or superuser) and removed by superusers. Multiple WireGuard profiles can be created for each user. A non-privileged user can create profiles for themselves. WireGuard Management in Mistborn

Extra Services

Mistborn makes extra services available. Mistborn Extra Services Available

Mistborn Firewall Metrics

Mistborn functions as a network firewall and provides metrics on blocked probes from the internet. Mistborn Firewall Metrics

Authentication

There are multiple ways to authenticate and use the system.

Mistborn Multi Factor Authentication - Authenticator App Setup

Profile: WireGuard Authentication

Mistborn always authenticates with WireGuard. You must have a valid WireGuard configuration file associated with the correct internal IP address. A classic Mistborn profile (WireGuard Only) will allow you to access the internet and all services hosted by Mistborn once you have connected via WireGuard. Note: individual services may require passwords or additional authentication.

Profile: Multi Factor Authentication (MFA)

In addition to WireGuard, you may create a Mistborn profile enabling multi-factor authentication (MFA). You must first connect to Mistborn via WireGuard. Then all internet traffic will route you to the Mistborn webserver where you must first setup and thereafter authenticate with an app (Google Authenticator, Authy, etc.). You must go to http://home.mistborn to complete the authentication process.

Mistborn Multi Factor Authentication Prompt

MFA Internet Access

Internet access is blocked via iptables until authentication is completed for an MFA profile. You must go to http://home.mistborn to complete the authentication process. Click "Sign Out" to re-block internet access until authentication completes again.

Mistborn Multi Factor Authentication - Token Prompt

MFA Mistborn Service Access - Fixed on 4 December 2020

Mistborn service access is blocked via traefik until Mistborn authentication is complete. You will not be able to access the web pages for pihole, cockpit, or any extra services until authentication is complete for an MFA profile. Attempting to visit one of these pages will produce a "Mistborn: Not authorized" HTTP 403. Click "Sign Out" to re-block access until authentication completes again.

Mistborn Multi Factor Authentication - Not Authorized (Login Incomplete)

Notes

• Sessions: Traefik checks the authenticated sessions on the server side to determine whether to allow access to the Mistborn service web pages. If an open session exists for your Mistborn IP address then access will be granted. You may close all sessions by clicking "Sign Out" on the Mistborn home page. Expired sessions are regularly cleaned by the Mistborn system (celery periodic task).

Mistborn Subdomains

Mistborn uses the following domains (that can be reached by all WireGuard clients):

Service	Domain	Default Status
Home	home.mistborn	On
Pihole	pihole.mistborn	On
Cockpit	cockpit.mistborn	On
Nextcloud	nextcloud.mistborn	Off
Rocket.Chat	chat.mistborn	Off
Home Assistant	homeassistant.mistborn	Off
Vaultwarden	bitwarden.mistborn	Off
Jellyfin	jellyfin.mistborn	Off
Syncthing	syncthing.mistborn	Off
OnlyOffice	onlyoffice.mistborn	Off
Jitsi	jitsi.mistborn	Off
Guacamole	guac.mistborn	Off
RaspAP	raspap.mistborn	Off
Wazuh	wazuh.mistborn	Off

Default Credentials

These are the default credentials to use in the services you choose to use:

Service	Username	Password
Pihole		{{default mistborn password}}
Cockpit	cockpit	{{default mistborn password}}
Wazuh	mistborn	{{default mistborn password}}
Nextcloud	mistborn	{{default mistborn password}}
Guacamole	mistborn	{{default mistborn password }}
RaspAP	mistborn	{{default mistborn password}}

You can find the credentials sent to the Docker containers in: /opt/mistborn/.envs/.production/

Gateway Setup

Mistborn will generate the WireGuard configuration script for the Gateway. From a base Ubuntu/Debian/Raspbian operating system the following packages are recommended to be installed beforehand:

Gateway Requirements

• WireGuard (you can consult the Mistborn WireGuard installer: mistborn/scripts/subinstallers/wireguard.sh)
• Openresolv (a WireGuard dependency that is also installed via the Mistborn WireGuard installer)
• Fail2ban

Install Gateway WireGuard config file

On Mistborn:

• Click View Config on the Gateways tab in Mistborn
• Highlight the config
• Copy (Ctrl-C)

On Gateway:

• Paste the config to /etc/wireguard/gateway.conf
• Run sudo systemctl start wg-quick@gateway
• Run sudo systemctl enable wg-quick@gateway

Phones and Mobile Devices

All your devices can be connected to Mistborn as WireGuard clients.

First steps:

1. Device: Download the WireGuard app on your device. Links: Android Apple
2. Mistborn: Create a WireGuard profile for the device.
3. Device: Scan WireGuard client QR code in WireGuard app.
4. Device: Enable WireGuard connection.

All of you device network traffic is now being routed through WireGuard. Ads and malicious sites are blocked by pihole. DNS queries are verified via DNScrypt.

But wait, there's more! You can:

• visit the Mistborn web interface through your phone's browser.
• download the apps for any extra services you have running and connect them to your Mistborn using the Mistborn domains.

App Links

	Android	Apple
Nextcloud	Nextcloud	Nextcloud
Syncthing	Syncthing
Jitsi Meet	Jitsi Meet	Jitsi Meet
Bitwarden	Bitwarden	Bitwarden
Jellyfin	Jellyfin	Jellyfin
Home Assistant	Home Assistant	Home Assistant
Rocket.Chat	Rocket.Chat	Rocket.Chat

TLS Certificate

Some apps require TLS (HTTPS). All traffic to Mistborn domains already occurs over WireGuard but to keep apps running, a TLS certificate exists for Mistborn and can be imported into your device's trusted credentials in the security settings. This certificate is checked every day and will be re-generated when expiration is less than 30 days away.

The TLS certificate can be found here:

/opt/mistborn_volumes/base/tls/cert.crt

FAQ

Frequently Asked Questions

Where is my data?

The Docker services mount volumes located in:

/opt/mistborn_volumes

The core Mistborn services have volumes mounted in /opt/mistborn_volumes/base. These should not be modified. The extra services' volumes are mounted in:

/opt/mistborn_volumes/extra

Your data from Nextcloud, Syncthing, Vaultwarden, etc. will be located there.

How do I SSH into Mistborn?

If Mistborn is installed via SSH then an iptables rule is added allowing external SSH connections from the same source IP address only. If Mistborn was installed locally then no external SSH is permitted.

SSH is permitted from any device connected to Mistborn by WireGuard.

Password authentication in enabled. Fail2ban blocks IPs with excessive failed login attempts.

You can SSH using the Mistborn domain when connected by WireGuard:

ssh [email protected]

How do I change the upstream DNSCrypt servers?

The upstream servers used by dnscrypt-proxy are set in:

base.yml:

services:
...
  dnscrypt-proxy:
  ...
    environment:
    ...
      - DNSCRYPT_SERVER_NAMES=[...]

The available options are here: https://download.dnscrypt.info/dnscrypt-resolvers/v2/public-resolvers.md

How do I purge an extra service/start fresh?

This is a manual process for the foreseeable future because it is destructive and cannot be undone. In order to purge an extra service do the following:

• Stop and disable the service

This can be done from the Mistborn GUI or:

sudo systemctl stop Mistborn-<service name>
sudo systemctl disable Mistborn-<service name>

• Remove the data folder

Locate the correct folder: sudo ls -ahl /opt/mistborn_volumes/extra/

Be careful: Now remove the folder: sudo rm -r /opt/mistborn_volumes/extra/<service name>

• Remove the variables file

Locate the file: sudo ls -ahl /opt/mistborn/.envs/.production/

Be careful: Now remove the file: sudo rm /opt/mistborn/.envs/.production/.<service name>

Now you can restart the service from the GUI or manually and it should be a first run experience.

Troubleshooting

Once you're connected to WireGuard you should see .mistborn domains and the internet should work as expected. Be sure to use http (http://home.mistborn). WireGuard is the encrypted channel so there's usually no need to bother with TLS certs (WebRTC functionality and some mobile apps require TLS so it is available). Here are some things to check if you have issues:

Check if you can ping an external IP address:

ping 1.1.1.1

Check if you can resolve local DNS queries:

dig home.mistborn

Check if you can resolve external DNS queries:

dig cyber5k.com

See if any docker containers are stopped:

sudo docker container ls -a

Check the running log for Mistborn-base:

sudo journalctl -xfu Mistborn-base

Mistborn-base is a systemd process and at any time restarting it should get you to a working state:

sudo systemctl restart Mistborn-base

The WireGuard processes run independently of Mistborn and will still be up if Mistborn is down. You can check running WireGuard interfaces with:

sudo wg show

Note the Mistborn naming convention for WireGuard interfaces on the server is wg. So if the particular WireGuard process is listening on UDP port 56392 then the interface will be named wg56392 and the config will be in /etc/wireguard/wg56392.conf

The dev/ folder contains a script for completing a hard reset: destroying and rebuilding the system from the original backup:

sudo ./dev/rebuild.sh

Troubleshooting WireGuard

Ensure that your public IP address in your client profile (e.g. Endpoint = <Mistborn public IP address>:<random port>) is actually publicly available (not in 10.0.0.0/8, 172.16.0.0/12, or 192.168.0.0/16) if you are attempting to access Mistborn across the internet.

Troubleshooting Extra Services

Each extra service has its own systemd process which can be monitored:

sudo journalctl -xfu Mistborn-homeassistant
sudo journalctl -xfu Mistborn-bitwarden
sudo journalctl -xfu Mistborn-syncthing
sudo journalctl -xfu Mistborn-jellyfin
sudo journalctl -xfu Mistborn-nextcloud
sudo journalctl -xfu Mistborn-jitsi
sudo journalctl -xfu Mistborn-guacamole
sudo journalctl -xfu Mistborn-rocketchat
sudo journalctl -xfu Mistborn-onlyoffice
sudo journalctl -xfu Mistborn-tor
sudo journalctl -xfu Mistborn-raspap
sudo journalctl -xfu Mistborn-wazuh

Troubleshooting Docker

Instead of defaulting to a system DNS server, Docker will try to use a public DNS server (e.g. 8.8.8.8). If you're having issues pulling or building Docker containers with "failure to connect" errors, this is the likely problem. You can manually set the DNS server Docker should use with the DOCKER_OPTS field in /etc/default/docker. Example:

DOCKER_OPTS="--dns 192.168.50.1 --dns 1.1.1.1"

Be sure to restart Docker afterward:

sudo systemctl restart docker

Troubleshooting Upgrade from Ubuntu 18.04 to 20.04

New installations of 18.04 and 20.04 after 25 April 2020 don't seem to be having issues. If you installed Mistborn on Ubuntu 18.04 prior to 25 April 2020 and then upgrade to 20.04 you may have one minor issue described below.

Owing to changes in docker NAT rules and container DNS resolution, some WireGuard client configurations generated with Mistborn before 25 April 2020 (be sure to update Mistborn) may experience issues after upgrading to Ubuntu 20.04 LTS. Symptoms: can ping but can't resolve DNS.

Solution: Edit the WireGuard client config and set the DNS directive as follows:

DNS = 10.2.3.1

Close the config and restart the client WireGuard process.

Troubleshooting Raspberry Pi OS (Raspbian)

Be sure to always reboot after updating the kernel. When the kernel is updated the kernel modules are deleted (for the currently running kernel) and you will have issues with any function requiring kernel modules (e.g. iptables or wireguard).

Note: The Raspberry Pi OS 64-bit BETA (versions from May 2020 and prior) have a bug where the os-release info indicates that it is Debian. Mistborn proceeds to install as though it were Debian. Since it's not Debian there are errors.

Troubleshooting Debian 10

Run updates and restart before installing Mistborn (sudo apt-get update && sudo apt-get -y dist-upgrade && sudo shutdown -r now). Some older Linux kernels will prevent newer WireGuard versions from installing.

Troubleshooting PostgreSQL 11 to 16

The update (or update.sh underneath) process will automatically upgrade existing PostgreSQL 11 databases to PostgreSQL 16. This is accomplished by:

• Dumping the existing PostgreSQL 11 database to a compressed .sql.gz file in backups
• Checking the major version of the dump file
• If it's a version before 16 then the PostgreSQL data volume is dropped and PostgreSQL 16 recovers the backup

If the initial dump fails then the automatic process will stop. When Mistborn starts up you will see errors indicating that the current Django and PostgreSQL tools cannot connect to PostgreSQL 11. If manual remediation is required these commands may be helpful:

cd /opt/mistborn

# create a backup
mistborn-cli dbbackup

# identify backup files available
mistborn-cli dbbackuplist

# build from backup
mistborn-cli dbupgrade --backup-filename backup_xxxxxx.sql.gz

Technical and Security Insights

These are some notes regarding the technical design and implementations of Mistborn. Feel free to contact me for additional details.

Attack Surface

See the Mistborn Network Security wiki entry.

• WireGuard: WireGuard is the only way in to Mistborn. When new WireGuard profiles are generated they are attached to a random UDP port. WireGuard does not respond to unauthenticated traffic. External probes on the active WireGuard listening ports are not logged and do not appear on the Metrics page.
• SSH: If Mistborn is installed over SSH (most common) then an iptables rule is added allowing future SSH connections from the same source IP address. All other external SSH is blocked. Internal SSH (over the WireGuard tunnels) is allowed. Password authentication is allowed. The SSH key for the mistborn user is only accepted from internal source IP addresses. Fail2ban is also installed.
• Traefik: Iptables closes web ports (TCP 80 and 443) from external access and additonally all web interfaces are behind the Traefik reverse-proxy. All web requests (e.g. home.mistborn) must be resolved by Mistborn DNS (Pihole/dnsmasq) and originate from a WireGuard tunnel.
• Docker: When Docker exposes a port it creates a PREROUTING rule in the NAT table to catch eligible network requests. This means that even if your INPUT chain policy is DROP, your docker containers with exposed ports can receive and respond to traffic. Whenever Mistborn brings up a docker container with an exposed port it creates an iptables rule to block external traffic to that service.

Firewall

• IPtables: Iptables rules and chains are manipulated directly. If UFW is present it is disabled. IPtables-persistent is used to save a simple set of secure default rules (most importantly setting the INPUT and FORWARD policies to DROP and allowing ESTABLISHED and RELATED traffic) that will be effective immediately upon system startup. Additional rules and chains are created by Docker on startup. Mistborn also creates some iptables chains during installation that are saved in the persistent rules. Mistborn iptables chains and rules are designed to work with Docker's with logic that is easy to follow. A power cycle will always result in a working state.
• PostUp/PostDown: WireGuard configuration files on Mistborn include PostUp and PostDown directives that set routes and iptables rules for each WireGuard client individually.
• WireGuard: There is a one-to-one mapping between each WireGuard client and server instance listening on Mistborn. By default WireGuard clients cannot talk directly to each other but can use shared services and resources on Mistborn (e.g. Syncthing, Nextcloud, Jitisi, etc). Toggling the "client-to-client" option will enable direct client-to-client communication.
• Metrics: In addition to the iptables INPUT policy set to DROP, an iptables chain exists that logs the packet meta data before dropping it. Mistborn redirects packets that will be dropped to this chain instead. A summary of the data about these dropped packets (unsolicited network traffic) can be found on the Metrics page.
• Coppercloud: Coppercloud works by populating ipsets with the ipset module in iptables to DROP (blacklist) or ACCEPT (whitelist) a given set of IP addresses. Upon system startup a celery task will compile the IP addresses, create the ipsets, and iptables rules.

Additonal Notes

• Interface names are not hardcoded anywhere in Mistborn. Two commands that are used in different circumstances to determine the default network interface and the interface that would route a public IP address are: ip -o -4 route show to default and ip -o -4 route get 1.1.1.1.
• The "Update" button will pull updated Docker images for mistborn, postgresql, redis, pihole, and dnscrypt. Those services will then be restarted.
• The generated TLS certificate has an RSA modulus of 4096 bits, is signed with SHA-256, and is good for 397 days. The certificate is checked daily and will regenerate when expiration is within 30 days.
• Outbound UDP on port 53 is blocked. All DNS requests should be handled by the dnscrypt_proxy service and if any client, service, etc. tries to circumvent that it is blocked.
• Unattended upgrades are set to automatically install operating system security updates.
• Ownership of mistborn files is set to the system mistborn user and access to environment variables is disabled for users other than the owner.

Firewall Penetration

WireGuard runs over UDP. A shortcoming of WireGuard is that there is no simple option for using WireGuard over TCP, which is a slower protocol than UDP. However there are a few UDP ports that are often allowed through firewalls:

• UDP/53: The domain name system (DNS) protocol commonly uses this port and is essential to internet traffic
• UDP/443: The QUIC protocol uses this port and is becoming more commonly used to make internet traffic more efficient

By default the WireGuard configs generated in Mistborn use a random UDP port. However, after version v2.3.0, that port can be changed to either 53 or 443 and the server will accept connections to those UDP ports.

UDP 53 example

Original (example)

[Peer]
PublicKey = pt/503ILuzQB4uPbdgdXJ7RoRO+FTff69Gn/vLC4my0=
PresharedKey = YuAY+0v5/dVeaIVElGdvd/R+nKQP4pa5sG4BwjiSClg=
AllowedIPs = 0.0.0.0/0,::/0
Endpoint = 167.71.xxx.xxx:53028

Change the Endpoint = line to attempt to connect on UDP port 53:

[Peer]
PublicKey = pt/503ILuzQB4uPbdgdXJ7RoRO+FTff69Gn/vLC4my0=
PresharedKey = YuAY+0v5/dVeaIVElGdvd/R+nKQP4pa5sG4BwjiSClg=
AllowedIPs = 0.0.0.0/0,::/0
Endpoint = 167.71.xxx.xxx:53

Featured In

• Linux Magazine November 2020 (featuring Mistborn version from early May 2020)
• Awesome Open Source July 2020
• DB Tech May 2021

Languages

Translations are planned for:

• de: German
• pt: Portuguese
• fr: French
• es: Spanish

If you would like to assist with these or other languages, please reach out to me at [email protected]

Support Mistborn

If you are enjoying Mistborn please support the ongoing maintenance and testing effort

Reselling Mistborn Enterprise

If you would like to resell Mistborn Enterprise (includes unlocking the professional features plus branding) send a proposal of terms to me at [email protected]