Debian setup DNS-over-TLS over haproxy with TLS-1.3 support

 Finally, final version of TLS 1.3 has now been published as of August 2018

TLS 1.3 in 2018, encrypted connections are now more secure and faster than ever.

What is TLS?

TLS stands for Transport Layer Security and is the successor to SSL (Secure Sockets Layer). TLS provides secure communication between web browsers and servers. The connection itself is secure because symmetric cryptography is used to encrypt the data transmitted. The keys are uniquely generated for each connection and are based on a shared secret negotiated at the beginning of the session, also known as a TLS handshake.

Who providing DNS-over-TLS service?
1. Quad9
2. Cloudflare
3. Dnsprivacy.org public test servers ( blahdns.com )

Who using DNS-over-TLS?
1. Router
2. Stubby
3. Unbound 
4. Knot-resolver
5. Android 9 PIE
6. Linux systemd

Below is a demo how I migrate from knot-resolver TLS to haproxy TLS to support TLS 1.3

// ENV, Debian9, with certbot, knot-resolver, haproxy ready

// certbot standalone cert
$ certbot certonly --standalone -d dns.jp.blahdns.com --non-interactive --agree-tos --email [email protected]

// Merge fullchain & privkey into one file
$ cat /etc/letsencrypt/archive/dns.jp.blahdns.com/fullchain1.pem /etc/letsencrypt/archive/dns.jp.blahdns.com/privkey1.pem > /etc/haproxy/dns.jp.blahdns.pem

// Install gcc, make, etc. component
$ apt install build-essential libpcre2-dev zlib1g-dev

// Install openssl 1.1.1
$ wget https://www.openssl.org/source/openssl-1.1.1.tar.gz
$ tar -xzf openssl-1.1.1.tar.gz
$ cd openssl-1.1.1
$ ./config --prefix=/opt/openssl-1.1.1 shared
$ make && make install

// haproxy.cfg sample file

global
        log /dev/log    local0
        chroot /var/lib/haproxy
        user haproxy
        group haproxy
        maxconn  4000
        pidfile  /var/run/haproxy.pid
        tune.ssl.default-dh-param  2048
        ssl-default-bind-ciphers TLS13-AES-256-GCM-SHA384:TLS13-AES-128-GCM-SHA256:TLS13-CHACHA20-POLY1305-SHA256:EECDH+AESGCM:EECDH+CHACHA20
        ssl-default-bind-options no-sslv3 no-tlsv10 no-tlsv11

        # Default SSL material locations
        ca-base /etc/ssl/certs
        crt-base /etc/ssl/private

defaults
        mode    http
        option  dontlognull
        option  redispatch
        option  http-server-close
        retries 3
        maxconn 2000
        timeout connect 5s
        timeout check 10s
        timeout client 20s
        timeout server 15s

listen dot-in
    bind :::853 v4v6 tfo ssl crt /etc/haproxy/dns.jp.blahdns.pem
    mode tcp
    server dot-server 127.0.0.1:50

Besure your haproxy is support TLSv.13

References
1. https://www.cloudflare.com/ssl/encrypted-sni/
2. https://serversforhackers.com/c/letsencrypt-with-haproxy
3. https://dnsprivacy.org/wiki/display/DP/DNS+Privacy+Test+Servers
4. https://limbenjamin.com/articles/running-https-ssh-vpn-on-port-443.html
5. https://discourse.haproxy.org/t/tls-termination-proxy-with-both-tls-and-plain-tcp-on-the-same-port/2885/10
6. https://blog.chmd.fr/ssh-over-ssl-episode-4-a-haproxy-based-configuration.html