dnss

dnss is a daemon for using DNS over HTTPS.

It can act as a proxy (the most common use case), and as a server (in case you want end to end control).

Features

• Supports the JSON-based protocol as implemented by dns.google.com (reference).
• Supports the DNS Queries over HTTPS (DoH) proposed standard (and implemented by Cloudflare's 1.1.1.1).
• Local cache (optional).
• HTTP(s) proxy support, autodetected from the environment.
• Monitoring HTTP server, with exported variables and tracing to help debugging.
• Separate resolution for specific domains, useful for home networks with local DNS servers.

Install

Debian/Ubuntu

The dnss package installs the daemon configured in proxy mode and ready to use, using Google's public resolvers (and easily changed via configuration).

sudo apt install dnss

Manual install

To download and build the binary:

go install blitiri.com.ar/go/dnss

And if you want to configure the daemon to be automatically run by systemd:

# Copy the binary to a system-wide location.
sudo cp "$GOPATH/bin/dnss" /usr/local/bin/

# Set it up in systemd.
sudo cp "$GOPATH"/src/blitiri.com.ar/go/dnss/etc/systemd/dns-to-https/* \
	/etc/systemd/system/

sudo systemctl dnss enable

Examples

DNS server (proxy mode)

Listens on port 53 for DNS queries, resolves them using the given HTTPS URL.

# Use the default HTTPS URL (currently, dns.google.com):
dnss -enable_dns_to_https

# Use Cloudflare's 1.1.1.1:
dnss -enable_dns_to_https -https_upstream="https://1.1.1.1/dns-query"

# Use Google's dns.google.com:
dnss -enable_dns_to_https -https_upstream="https://dns.google.com/resolve"

HTTPS server

Receives DNS over HTTPS requests, resolves them using the machine's configured DNS servers, and returns the replies. You will need to have certificates for the domains you want to serve.

Supports both DoH and JSON modes automatically, and the endpoints are /dns-query and /resolve.

# Serve DNS over HTTPS requests, take certificates from letsencrypt.
DOMAIN=yourdomain.com
dnss -enable_https_to_dns \
  -https_key=/etc/letsencrypt/live/$DOMAIN/privkey.pem \
  -https_cert=/etc/letsencrypt/live/$DOMAIN/fullchain.pem