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We're at a time where we're reminded by Edward Snowden (Twitter link)[1] himself, that large corporations hosting VPNs should not be trusted.
1: reminded by Edward Snowden (Twitter link)
{{< twitter_simple 1438291654239215619 >}}
For traveling and some form of privacy enhancements we are however in need for VPN solutions. Given trust in big tech is at an all time low, I'm looking to setup my own VPN using a recent open source solution WireGuard[1] on Vultr[2].
WireGuard logo[1]
WireGuard is a project by Jason Donenfeld (Twitter link)[1]. It was designed with the goals of **ease of use, simplicity and modern cryptography**. A counterweight to OpenVPN and IPsec. The spec is meant to be easy to implement in very few lines of code, allowing auditability for security vulnerabilities and the claim of having "a minimal attack surface".
1: Jason Donenfeld (Twitter link)
Contrary to common solutions, it passes traffic only over UDP.
WireGuard was incorporated into the Linux 5.6 kernel and released in March 2020. As we all know, there is no greater honor for software engineers to receive the praise of Linus Torvalds. Linus called the implementation "work of art compared to OpenVPN and IPSec" on the mailing list[1]:
Can I just once again state my love for it and hope it gets merged soon? Maybe the code isn't perfect, but I've skimmed it, and compared to the horrors that are OpenVPN and IPSec, it's a work of art.
The second operating system after Linux with integrated WireGuard support, and my personal favorite for servers, was OpenBSD. Matt Dunwoodie's implementation for OpenBSD, written in C landed in OpenBSD 6.8, October 2020 and was announced on the OpenBSD mailing list[1] by Jason A. Donenfeld himself:
I should also note that the upstreaming process to OpenBSD was extremely pleasant.
We did three patch revisions, with useful feedback on each one and a very supportive community.
The OpenBSD code is distributed under a free ISC license. We can consider this solution one of the safest and easiest to use VPNs available to us.
We create a $5 VPS on Vultr[1] in either Germany or Japan, both countries with a high internet freedom index. The setup here is similar to what I noted down earlier on a OpenBSD base configuration[2]. Create a user and add the public keys for ssh that Vultr added to our root user:
adduser cp .ssh/authorized_keys /home/<user>/.ssh/
Allow `doas` for our new user
vi /etc/doas.conf permit persist :wheel usermod -G wheel <user>
And disallow root to ssh into the box
vi /etc/ssh/sshd_config PermitRootLogin no PasswordAuthentication no
Install updates and reboot
syspatch reboot
We can now begin the VPN setup.
Install WireGuard tools
doas pkg_add wireguard-tools
Enable IP and IPv6 forwarding to allow packets to move between the WireGuard interface and the egress interface.
doas sysctl net.inet.ip.forwarding=1 doas sysctl net.inet6.ip6.forwarding=1
And ensure it persists a reboot
doas vi /etc/sysctl.conf
sysctl net.inet.ip.forwarding=1 sysctl net.inet6.ip6.forwarding=1
Create the WireGuard keys
doas mkdir /etc/wireguard doas chmod 700 /etc/wireguard doas su # become root cd /etc/wireguard wg genkey > secret.key chmod 600 secret.key wg pubkey < secret.key > public.key
While being located in `/etc/wireguard`, create the file `vi /etc/wireguard/wg0.conf` with these contents:
[Interface] PrivateKey = <SERVER PRIVKEY> ListenPort = 51820 # iOS / Android smartphone [Peer] PublicKey = <CLIENT PUBKEY> AllowedIPs = 10.0.0.2/32
Navigate with vi to the private key and use the `:r private.key` shortcut to paste the contents into the right place. Each peer is assigned a key pair (a public and private key) and an internal IP address. The outgoing traffic from a client is encrypted with the servers public key and enveloped in UDP. We use the `10.0.0.0/24` subnet for the VPN. The IP `10.0.0.1` will be the server through which traffic is tunneled.
Create `vi /etc/hostname.wg0` with the following contents:
inet 10.0.0.1 255.255.255.0 NONE up !/usr/local/bin/wg setconf wg0 /etc/wireguard/wg0.conf
Next we configure the firewall pf and allow connections from clients. We open the port 51820 on which WireGuard will listen. Configure pf with `vi /etc/pf.conf`. Note that `ifconfig` shows our network device is `vio0` but yours might be different:
pass in on wg0 pass in inet proto udp from any to any port 51820 pass out on egress inet from (wg0:network) nat-to (vio0:0)
That's it. Optionally assign a A and AAAA DNS record from a domain you're owning for quick access.
Install WireGuard on your iOS or Android phone
We can generate QR codes on terminals with the utility `qrencode`. Install and test it with
doas pkg_add libqrencode qrencode -s 6 "Your text here!" --type=UTF8 --level=M
Example qrencode[1]
Now create the client config:
umask 077 && wg genkey > wg-private-client.key wg pubkey < wg-private-client.key > wg-public-client.key
Print the client pubkey and add it to the server config to the peer section in `/etc/wireguard/wg0.conf` from above.
cat wg-public-client.key
Then reboot the server or run
doas sh /etc/netstart wg0 doas pfctl -f /etc/pf.conf
We're done with the WireGuard server (for one client configured).
We can check if the port is open with netcat `nc -zv -u <IP or FQDN> 51820`.
Print the client private key for our client config:
cat wg-private-client.key
Create `~/wg-client.conf` with the following content:
[Interface] PrivateKey = <CLIENT PRIVKEY> Address=10.0.0.2/32 DNS = 9.9.9.9 # Server [Peer] PublicKey = <SERVER PUBKEY> Endpoint = <IP or FQDN>:51820 AllowedIPs = ::/0, 0.0.0.0/0 PersistentKeepalive = 25
The first client will be assigned 10.0.0.2, if we add more peers we just increment this number.
AllowedIPs 0.0.0.0/0 and ::/0 mean all IP addresses in IPv4 and IPv6 will use the WireGuard tunnel.
Print the QR code for the config above and scan it with your smartphone for importing the config:
qrencode --read-from=wg-client.conf --type=UTF8 --level=M
Show the status of connected peers
doas wg show wg0
We're done.
I'm running Ubuntu Server on my Raspberry Pi and want it to enjoy the same privacy considerations as my other clients.
Install WireGuard and resolvconf on the Ubuntu client machine:
sudo apt-get install wireguard resolvconf
Follow the key creation and create a client config, see that I incremented the interface address to 3 here.
[Interface] PrivateKey = <CLIENT PRIVKEY> Address=10.0.0.3/32 DNS = 9.9.9.9 # Server [Peer] PublicKey = <SERVER PUBKEY> Endpoint = <IP or FQDN>:51820 AllowedIPs = ::/0, 0.0.0.0/0 PersistentKeepalive = 25
Copy the config in place on the Ubuntu client `/etc/wireguard/wg0.conf`. And test the configuration with
systemctl start wg-quick@wg0 curl ifconfig.me
We expect the IP of the VPN server to be shown. If this works, enable WireGuard to run on reboot
sudo systemctl enable wg-quick@wg0
Voilà!
See a snippet on how to add any client configuration to a WireGuard server[1].
1: snippet on how to add any client configuration to a WireGuard server
On the server, we can show the connected clients and the bandwidth of each with the show command:
doas wg show
WireGuard wg show output[1]
Enjoy your private and secure VPN!
