Using TLS in untrusted networks

Let’s assume that you have installed gokrazy on a Raspberry Pi and are currently successfully updating it over the network like so:

gok update

Enabling TLS

To start using TLS, edit your gokrazy instance’s config.json:

gok edit

In the config.json, in the Update field, add a "UseTLS": "self-signed" line (don’t forget adding a comma to the previous line):

{
    "Hostname": "docs",
    "Update": {
        "HTTPPassword": "secret",
        "UseTLS": "self-signed"
    },
    "Packages": [
        "github.com/gokrazy/fbstatus",
        "github.com/gokrazy/hello",
        "github.com/gokrazy/serial-busybox",
        "github.com/gokrazy/breakglass"
    ]
}

Save your changes and close the file, then run a first update with the --insecure flag:

gok update --insecure

The gok CLI will:

• generate a self-signed certificate
• include the certificate in the gokrazy installation
• verify the certificate fingerprint in future updates

The gokrazy installation will start listening on TCP port 443 for HTTPS connections and redirect any HTTP traffic to HTTPS. When opening the gokrazy web interface in your browser, you will need to explicitly permit communication due to the self-signed certificate.

For all future updates, remove the --insecure flag:

gok update

You can now safely update your gokrazy installation over untrusted networks, such as unencrypted WiFi networks.

Disabling TLS

Change the UseTLS line to "UseTLS": "off" in your instance’s config.json.

Run gok update --insecure, and afterwards gokrazy will no longer contain the certificates and will serve unencrypted HTTP again.