<chapter xmlns="http://docbook.org/ns/docbook"
         xmlns:xlink="http://www.w3.org/1999/xlink"
         xmlns:xi="http://www.w3.org/2001/XInclude"
         version="5.0"
         xml:id="sec-dnscrypt-proxy">

  <title>DNSCrypt client proxy</title>

  <para>
    The DNSCrypt client proxy relays DNS queries to a DNSCrypt enabled
    upstream resolver. The traffic between the client and the upstream
    resolver is encrypted and authenticated, mitigating the risk of MITM
    attacks, DNS poisoning attacks, and third-party snooping (assuming the
    upstream is trustworthy).
  </para>

  <sect1><title>Basic configuration</title>

  <para>
    To enable the client proxy, set
    <programlisting>
      services.dnscrypt-proxy.enable = true;
    </programlisting>
  </para>

  <para>
    Enabling the client proxy does not alter the system nameserver; to
    relay local queries, prepend <literal>127.0.0.1</literal> to
    <option>networking.nameservers</option>.
  </para>

  </sect1>

  <sect1><title>As a forwarder for another DNS client</title>

  <para>
    To run the DNSCrypt proxy client as a forwarder for another
    DNS client, change the default proxy listening port to a
    non-standard value and point the other client to it:
    <programlisting>
      services.dnscrypt-proxy.localPort = 43;
    </programlisting>
  </para>

  <sect2><title>dnsmasq</title>
  <para>
    <programlisting>
      {
        services.dnsmasq.enable = true;
        services.dnsmasq.servers = [ "127.0.0.1#43" ];
      }
    </programlisting>
  </para>
  </sect2>

  <sect2><title>unbound</title>
  <para>
    <programlisting>
      {
        services.unbound.enable = true;
        services.unbound.forwardAddresses = [ "127.0.0.1@43" ];
      }
    </programlisting>
  </para>
  </sect2>

  </sect1>

</chapter>
