Thank you to Wireguard VPN for making this blog possible.
Given all the false advertising around virtual private networks (VPNs), it sounds counter-intuitive that the same thing would be used to “expose” something to the internet.
But not all VPN advertising is fake, and some aspects of it are rather useful—in ways that are not often portrayed by VPN providers.
Skip the ranting tangent (Not recommended)
What is a VPN?
In essence, it is exactly what it says. A private network that is virtual.
What is a network?
Connection between two more devices. In the context of the internet, the connection is usually established using
- copper cables
- radio waves
- fiber optic cables
A virtual nework?
In computing, virtual refers to hardware that does not exist physically. It is existing hardware but in software it appears as a device that is distinct from what exists physically.
A now common example is virtualised CPUs. A physical CPU that has sixteen cores can be presented in software as two CPUs with eight cores each.
Likewise, virtual networks use the existing network hardware but appear as a completely separate network in software.
So a Virutal Private Network?
To be fair, a lot of networks are private in that they cannot be accessed by members who are not directly connected to the network. Every home router of today sets up a LAN—local area network. And only the devices connected directly to the router can access resources on the network (printers, other computers, etc.)
Normally such networks are restricted and no other computer from the internet is allowed access. While it is possible to open the network to others on the internet, it poses the security risk of unauthorised access.
Instead, by using virtualised networks one can allow access to certain devices on a network while using the existing hardware of the internet. Such networks, at least the modern implementations, typically use more secure ways to communicate and authenticate devices to one another.
XXXXX VPN encrypts and routes your network through our secure servers in N global locations…
It’s exactly what it says. Instead of joining the virtual network to access other devices on it, all connections to the internet are made through only one device of the network.
- the internet service provider sees a lot of requests
to XXXXX VPN’s server
- but not the actual site that you visit
- The site that you visit sees a lot of requests from the XXXXX
- but not from your actual device/IP address
This functionality is proxying – communication between two devices via an intermediary called a proxy.
It could be sort of anonymous. But VPN services are obliged to log and share logs with government authorities in some countries. And if the site has a way for users to login (as do most common ones today) the site knows who it is, just not your actual location, unless it already had access to device location and does not rely on IP address for locating in the first place.
The service offerred by majority of consumer VPN providers is essentially a web proxy. While they offer partial anonymitiy, it really depends on how it is being used. It irks me that advertising today makes it look like an all in one solution.
…allowing you to access geo-restricted content…
This is possibly the only real use for most consummer VPN services. And luckily, a lot more advertising is stressing on this more than the “encryption” and “anonymity” that they offer. Hurray! 🎊
Perhaps this Tom Scott video on VPN advertising claims from 2019 shifted the industry. Notably later on in 2022, Tom Scott himself concedes that VPNs are useful in the sponsor segment of a video. And the conecession was that they are useful forrr pretending you are visiting a site from a different country. 🥁
But not all VPNs are the same. Many large organisations deploy and use their own VPNs to allow their staff access to company resources from outside the premises. Using a VPN adds a layer of protection against unauthorised access by keeping the network private.
Using VPN to Expose the Home Network
Today is the third day of writing this post, and I have entered the main topic only now. Will I ever stop wandering?
I run some network-accessible services on a Raspberry Pi 400 on the home network that acts as my “server.” It’s mostly just a Syncthing instance to handle backup of my phone’s camera folder and a Photoprism instance to view said backups.
I would expand on it some day. But for now, it’s just two services.
And sometimes, I wished I could access these from outside home: on my phone, on a 4G connection.
How does one set that up?
By hosting one’s own VPN. Which often requires having at least one device with a public IP address.
I tried setting up OpenVPN first. But I could not understand any of what I was doing. I did set up a docker container based on docker.io/kylemann/openvpn. But not knowing what I was doing was troubling.
Wireguard was supposed to be easier to set up. It’s new and reportedly more secure out of the box.
Um… I didn’t check 😅
Wiring up Wireguard
sudo apt update sudo apt install wireguard-tools
It wasn’t too bad with Raspbian, eh? Good thing it’s based on Debian 11. I won’t be complaining for a while.
Then I went to read the documentation. Okay, I did read some beforehand too. I read the quickstart guides off the official website.
I understood a little. Then I read the man pages. And I stopped trying to understand and just started smashing buttons.
Also it has been a week since I started writing this post and I don’t remember what I did.
I started by using
wg set but soon realised it wasn’t easy.
I somehow figured out
Finally found the systemd
wg-quick@.service. So now I had an
/etc/wireguard/wg0.conf file to manage my configuration.
Eventually got it setup on two devices. Using the systemd
service. But what I didn’t know was that the service had
reload command. I could have used
systemctl reload wg-quick@wg0. But I realised it only
I used a very complicated
wg syncconf <(wg-quick strip wg0)
that seemed to fail at times
The configuration file itself was simple enough
[Interface] Address = 192.168.2.2/31 PrivateKey = RandomKeyThatIsWeirdlyShort [Peer 1] PublicKey = AnotherKeyButPublicStyle [Peer 2] PublicKey = AnotherKeyButPublicStyle [Peer n] PublicKey = AnotherKeyButPublicStyle
I had added every single device’s public key to every device’s configuration. So every wirguard instance had the public key of all its peers.
Everything should be working fine, right?
Of course not. The ‘public key’ was not enough to make a connection. Key exchanges are for authentication. Wireguard also needs an ‘endpoint.’
At first I had expected there to be some kind of global signalling server that handled this. Similar to how Syncthing establishes connections between devices.
Since that did not happen, I tried giving the private IP address assigned to each interface as the public endpoint. Of course it didn’t work. But I tried it because one of my peers had a public IP as its endpoint, so I thought if all peers connected to said public peer they should also be able to speak to each other via the public peer. And since the public peer would know the internal IPs I hoped they would suffice as endpoints.
Nope. They did not suffice. IP forwarding and things were needed. Things I did not know or understand until…
Unofficial WireGuard Documentation to Detangle
I discovered some community-created documentation for WireGuard and found out that the setup I was going for is called a “bounce server.”
To configure a WireGuard network composed of a mixture of devices with public and private IPs, one or more fo the public peers would be configured as bounce servers.
A bounce server
So far I configured peers as having an internal IP address with a 32-bit prefix. But instead a bounce server has a 24-bit (or smaller prefix)
[Interface] Address = 192.168.2.1/24
In doing so, I let wireguard know that the current peer may receive and forward traffic for other peers within the same subnet.
A peer that handles connections to the internet would have a prefix of 0 presumably.
Connecting to a peer via a bounce server
Normally each peer needs the public key of every peer it expects to connect to. But when part of a network that involves a bounce only the bounce is configured as a peer. I expect this means the bounce server decrypts traffic from one peer, then encrypts and sends it to the next using its own keys.
I am not too concerned by this since I have complete control over my bounce server. And also because the alternatives are STUN server which are more complicated.
Bounce not forwarding
I had set everything up as I should, and every peer was connected to the bounce. But I could not connect from one peer to the next over the wirguard network.
I decided to try enabling the
net.ipv4.ip_forward kernel parameter
that every guide was talking about. But
it was already enabled.
IRC for help
Seeing no other way to resolve and get it up and running I went to the recommended IRC room for help.
Turns out my firewall was blocking IP forwards. My server, running Fedora, used firewalld— the opposite of uncomplicated.
It has been a month and half since I started writing this post by the way. I am just going to get this over with as soon as possible.
Future me intervenes
Today is 11 January, 2023. It has been more than four months since I started this piece.
I do not even remember the exact details. I got my Wireguard VPN working. And while I did not have many uses for it at first, it has now become one of the most important (to me) internet services I manage.
I use it to provide my Nextcloud with an external storage backend via SSH over Wireguard to my home server. So I can move off old large files that I need access to, but don’t need to store on my rented VPS.
Eventually I have come to realise that I sidetracked too much, purs uing perfection and comprehensiveness that is not suited for this blog. This entry is neither bite-sized nor journalish.
As such, this ends the entry and I will move on to other ones. And try to stick to the idea of bitesyzed tech journal