WireGuard is an exciting, new, extremely simple VPN system that uses state-of-the-art cryptography. Its Linux implementation runs in the kernel, which provides a significant performance boost compared to traditional userspace VPN implementations
The WireGuard kernel module is great, but sometimes you might not be able to install new kernel modules. One example scenario is on a VPS that uses OpenVZ or LXC. For these cases, we can use wireguard-go, a userspace implementation of WireGuard. This is the same implementation used on MacOS and Windows.
This post focuses on Debian, however the instructions should mostly work on other Linux distros too.
Install WireGuard Tools
We need to install the WireGuard tools (
wg-quick). On Debian, you can run this as root:
echo "deb http://deb.debian.org/debian/ unstable main" > /etc/apt/sources.list.d/unstable.list printf 'Package: *\nPin: release a=unstable\nPin-Priority: 90\n' > /etc/apt/preferences.d/limit-unstable apt update apt install wireguard-tools --no-install-recommends
(see the WireGuard site for instructions if you're not on Debian)
Unfortunately, since wireguard-go is not packaged for Debian, we need to compile it ourselves. To compile it, we first need to install the latest version of the Go programming language (currently version 1.12.6):
cd /tmp wget https://dl.google.com/go/go1.12.6.linux-amd64.tar.gz tar zvxf go1.12.6.linux-amd64.tar.gz sudo mv go /opt/go1.12.6 sudo ln -s /opt/go1.12.6/bin/go /usr/local/bin/go
go version should show the version number.
Now that we've got Go, we can download and compile wireguard-go. Download the code:
cd /usr/local/src git clone https://git.zx2c4.com/wireguard-go
If you are on a system with limited RAM (such as a 64 MB or 128 MB "LowEndSpirit" VPS), you will need to do a small tweak to the wireguard-go code to make it use less RAM. Open
device/queueconstants_default.go and replace this:
MaxSegmentSize = (1 << 16) - 1 // largest possible UDP datagram PreallocatedBuffersPerPool = 0 // Disable and allow for infinite memory growth
With these values (taken from
MaxSegmentSize = 1700 PreallocatedBuffersPerPool = 1024
This will make it use a fixed amount of RAM (~20 MB max), rather than allowing memory usage to grow infinitely.
Now we can compile it:
cd wireguard-go make # "Install" it sudo cp wireguard-go /usr/local/bin
wireguard-go --version should work and show the version number.
You'll need to configure
/etc/wireguard/wg0.conf to contain the configuration for your peer. This post won't go into significant detail about this; please refer to another general WireGuard guide (like this one) for more details. Your
wg0.conf should end up looking something like:
[Interface] Address = 10.123.0.2 PrivateKey = 12345678912345678912345678912345678912345678 ListenPort = 51820 [Peer] PublicKey = 987654321987654321987654321987654321987654321 AllowedIPs = 10.123.0.1/32 Endpoint = 198.51.100.1:51820
We need to modify the systemd unit to pass the
WG_I_PREFER_BUGGY_USERSPACE_TO_POLISHED_KMOD flag to wireguard-go, to allow it to run on Linux. Open
and add this line directly below:
Finally, enable and start the systemd service:
systemctl enable wg-quick@wg0 systemctl start wg-quick@wg0
Enabling the systemd service will connect the VPN on boot, and starting the systemd service will connect it right now.
Now, everything should be working! You can check the status of
wg-quick by running
systemctl status wg-quick@wg0, which should return something like:
● firstname.lastname@example.org - WireGuard via wg-quick(8) for wg0 Loaded: loaded (/lib/systemd/system/wg-quick@.service; enabled; vendor preset: enabled) Active: active (exited) since Mon 2019-07-01 06:30:30 UTC; 1 day 22h ago
wg will give you a list of all the peers, and some details about them:
interface: wg0 public key: 987654321987654321987654321987654321987654321 private key: (hidden) listening port: 38917 peer: 987654321987654321987654321987654321987654321 endpoint: 198.51.100.1:51820 allowed ips: 10.123.0.1/32 latest handshake: 1 day, 22 hours, 59 minutes, 34 seconds ago transfer: 2.75 KiB received, 2.83 KiB sent