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# dnscrypt-proxy (Magyar)

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- Domain name resolution

This article or section needs expansion.

Reason: What is the difference to dnscrypt-wrapper? (Discuss in Talk:Dnscrypt-proxy (Magyar))

dnscrypt-proxy is a DNS proxy client with support for the encrypted DNS protocols DNS over HTTPS and DNSCrypt, which can be used to prevent man-in-the-middle attacks and eavesdropping. dnscrypt-proxy is also compatible with DNSSEC.

## Installation

Install the dnscrypt-proxy package.

## Configuration

The default configuration file referred to is at `/etc/dnscrypt-proxy/dnscrypt-proxy.toml`.

Tip While dnscrypt-proxy has no manual currently, the project maintains an extensive configuration wiki.

### Startup

Note Even though there are two ways to start the proxy, upstream recommends the `service` one.[1][2]

The service can be started in two mutually exclusive ways (i.e. only one of the two may be enabled):

1. With the systemd service `dnscrypt-proxy.service`.
   - The `listen_addresses` option must be configured (e.g. `listen_addresses = ['127.0.0.1:53', '[::1]:53']`) in the configuration file when using the service.
2. Through socket activation using `dnscrypt-proxy.socket`.
   - The `listen_addresses` option must be set to empty (i.e. `listen_addresses = [ ]`) in the configuration file, since systemd is taking care of the socket configuration.

### Select resolver

By leaving `server_names` commented out in the configuration file, dnscrypt-proxy will choose the fastest server from the sources already configured under `[sources]` [3]. The lists will be downloaded, verified, and automatically updated [4]. Thus, configuring a specific set of servers is optional.

To manually set which server is used, uncomment the `server_names` variable in the configuration file and select one or more of the servers. For example, to use Cloudflare's servers:

    server_names = ['cloudflare', 'cloudflare-ipv6']

Note This example uses Cloudflare's public DNS resolver. Replace it with a DNS resolver you trust. See Domain name resolution#Third-party DNS services.

A full list of resolvers is located at the upstream page or Github. If dnscrypt-proxy has run successfully on the system before, `/var/cache/dnscrypt-proxy/public-resolvers.md` will also contain a list. Look at the description for servers note which validate DNSSEC, do not log, and are uncensored. These requirements can be configured globally with the `require_dnssec`, `require_nolog`, `require_nofilter` options.

### Modify resolv.conf and coordinate with other local domain name resolvers

Modify the resolv.conf file and replace the current set of resolver addresses with the loopback IP addresses and options[5]:

    /etc/resolv.conf

    nameserver ::1
    nameserver 127.0.0.1
    options edns0

Next, existing services doing domain name resolution must be configured not to overwrite the settings. See resolv.conf#Overwriting of /etc/resolv.conf for details. They can be used, if they are configured to bind to different addresses than localhost and forward DNS requests to localhost port `53`. For example, systemd-resolved uses address `127.0.0.53` by default.

#### Disable any services bound to port 53

Tip If using #Unbound as your local DNS cache this section can be ignored, as unbound runs on port 53 by default.

To see if any programs are using port `53`, run:

    $ ss -lp 'sport = :domain'

If the output contains more than the first line of column names, you need to disable whatever service is using port `53`. For example, NetworkManager may try to activate a resolver automatically, but other network managers may have analogous components. You are ready to proceed once the above command outputs nothing more than the header line:

    Netid State   Recv-Q  Send-Q   Local Address:Port     Peer Address:Port Process

### Start systemd service

Finally, start/enable the `dnscrypt-proxy.service` unit or `dnscrypt-proxy.socket`, depending on which method you chose above.

### Check if dnscrypt-proxy is working

Open the browser and head to DnsLeakTest and do an extended test, if the results show servers that you have set in the configuration files it means that dnscrypt-proxy is working, otherwise something is wrong.

## Tips and tricks

### Enabling, downloading and auto-updating filter lists / block lists

This article or section is being considered for removal.

Reason: Overwriting files in `/usr/share/dnscrypt-proxy/utils/generate-domains-blocklist/` that are owned by the dnscrypt-proxy package is not a good idea. (Discuss in Talk:Dnscrypt-proxy (Magyar)#automatic blocklist updates)

Configure filter list sources in /usr/share/dnscrypt-proxy/utils/generate-domains-blocklist/domains-blocklist.conf. For example:

    # NextDNS CNAME cloaking list
    https://raw.githubusercontent.com/nextdns/cname-cloaking-blocklist/master/domains
    # AdGuard Simplified Domain Names filter
    https://adguardteam.github.io/AdGuardSDNSFilter/Filters/filter.txt
    # OISD.NL Big:
    https://big.oisd.nl/domainswild
    # HaGeZi Multi Pro
    https://raw.githubusercontent.com/hagezi/dns-blocklists/main/wildcard/pro-onlydomains.txt
    # HaGeZi Thread Intelligence Feeds
    https://raw.githubusercontent.com/hagezi/dns-blocklists/main/wildcard/tif-onlydomains.txt

Create a service to download & combine filter lists. /etc/systemd/system/dnscrypt-filterlist-update.service:

    [Unit]
    Description=DNSCrypt Filterlist Update

    [Service]
    Type=oneshot
    User=root
    WorkingDirectory=/usr/share/dnscrypt-proxy/utils/generate-domains-blocklist/
    ExecStart=generate-domains-blocklist -a domains-allowlist.txt -o blocklist.txt ; sleep 2 ; systemctl restart dnscrypt-proxy.service

    [Install]
    WantedBy=multi-user.target

Create a time to run on boot but also every 5 hours. /etc/systemd/system/dnscrypt-filterlist-update.timer:

    [Unit]
    Description=Run 15min after boot and every 5 hours (DNSCrypt Filterlist Update)

    [Timer]
    OnBootSec=15min
    OnUnitActiveSec=5h

    [Install]
    WantedBy=timers.target

Enable the timer:

    systemctl daemon-reload
    systemctl enable dnscrypt-filterlist-update.timer

Configure DNSCrypt to apply the created filter rules. /etc/dnscrypt-proxy/dnscrypt-proxy.toml:

    blocked_names_file = '/usr/share/dnscrypt-proxy/utils/generate-domains-blocklist/blocklist.txt'
    log_file = '/var/log/dnscrypt-proxy/blocked-names.log'

### Local DNS cache configuration

Tip dnscrypt-proxy can cache entries without relying on another program. This feature is enabled by default with the line `cache = true` in the configuration file.

It is recommended to run dnscrypt-proxy as a forwarder for a local DNS cache if not using dnscrypt-proxy's cache feature; otherwise, every single query will make a round-trip to the upstream resolver. Any local DNS caching program should work. In addition to setting up dnscrypt-proxy, you must setup your local DNS cache program.

#### Change port

In order to forward queries from a local DNS cache, dnscrypt-proxy should listen on a port different from the default `53`, since the DNS cache itself needs to listen on `53` and query dnscrypt-proxy on a different port. Port number `54` is used as an example in this section.

There are two methods for changing the default port:

Socket method

Edit `dnscrypt-proxy.socket` with the following contents:

    [Socket]
    ListenStream=
    ListenDatagram=
    ListenStream=127.0.0.1:54
    ListenStream=[::1]:54
    ListenDatagram=127.0.0.1:54
    ListenDatagram=[::1]:54

When queries are forwarded from the local DNS cache to `54`, `dnscrypt-proxy.socket` will start `dnscrypt-proxy.service`.

Service method

Edit the `listen_addresses` option in `/etc/dnscrypt-proxy/dnscrypt-proxy.toml` with the following:

    listen_addresses = ['127.0.0.1:54', '[::1]:54']

#### Example local DNS cache configurations

The following configurations should work with dnscrypt-proxy and assume that it is listening on port `54`.

##### Unbound

Configure Unbound to your liking (in particular, see Unbound#Local DNS server) and add the following lines to the end of the `server` section in `/etc/unbound/unbound.conf`:

      do-not-query-localhost: no
    forward-zone:
      name: "."
      forward-addr: ::1@54
      forward-addr: 127.0.0.1@54

Tip If you are setting up a server, add `interface: 0.0.0.0@53` and `access-control: your-network/subnet-mask allow` inside the `server:` section so that the other computers can connect to the server. A client must be configured with `nameserver address-of-your-server` in `/etc/resolv.conf`.

Restart `unbound.service` to apply the changes.

##### dnsmasq

Configure dnsmasq as a local DNS cache. The basic configuration to work with dnscrypt-proxy:

    /etc/dnsmasq.conf

    no-resolv
    server=::1#54
    server=127.0.0.1#54
    listen-address=::1,127.0.0.1

If you configured dnscrypt-proxy to use a resolver with enabled DNSSEC validation, make sure to enable it also in dnsmasq:

    /etc/dnsmasq.conf

    conf-file=/usr/share/dnsmasq/trust-anchors.conf
    dnssec

Restart `dnsmasq.service` to apply the changes.

##### pdnsd

Install pdnsd. A basic configuration to work with dnscrypt-proxy is:

    /etc/pdnsd.conf

    global {
        perm_cache = 1024;
        cache_dir = "/var/cache/pdnsd";
        run_as = "pdnsd";
        server_ip = 127.0.0.1;
        status_ctl = on;
        query_method = udp_tcp;
        min_ttl = 15m;       # Retain cached entries at least 15 minutes.
        max_ttl = 1w;        # One week.
        timeout = 10;        # Global timeout option (10 seconds).
        neg_domain_pol = on;
        udpbufsize = 1024;   # Upper limit on the size of UDP messages.
    }

    server {
        label = "dnscrypt-proxy";
        ip = 127.0.0.1;
        port = 54;
        timeout = 4;
        proxy_only = on;
    }

    source {
        owner = localhost;
        file = "/etc/hosts";
    }

Restart `pdnsd.service` to apply the changes.

### Enable EDNS0

This article or section needs expansion.

Reason: Name the advantages/motivation for enabling this. (Discuss in Talk:Dnscrypt-proxy (Magyar))

Extension Mechanisms for DNS that, among other things, allows a client to specify how large a reply over UDP can be.

Add the following line to your `/etc/resolv.conf`:

    options edns0

#### Test EDNS0

This article or section is out of date.

Reason: OARC's DNS Reply Size Test Server has been decommissioned. (Discuss in Talk:Dnscrypt-proxy (Magyar))

Make use of the DNS Reply Size Test Server, use the drill command line tool to issue a TXT query for the name rs.dns-oarc.net:

    $ drill rs.dns-oarc.net TXT

With EDNS0 supported, the "answer section" of the output should look similar to this:

    rst.x3827.rs.dns-oarc.net.
    rst.x4049.x3827.rs.dns-oarc.net.
    rst.x4055.x4049.x3827.rs.dns-oarc.net.
    "2a00:d880:3:1::a6c1:2e89 DNS reply size limit is at least 4055 bytes"
    "2a00:d880:3:1::a6c1:2e89 sent EDNS buffer size 4096"

## Troubleshooting

### "read-only file system" or "no such file or directory" when caching file

Set the correct ownership of `/var/cache/dnscrypt-proxy`, usually `dnscrypt-proxy:dnscrypt-proxy`.

Categories:

- Domain Name System (Magyar)
- Encryption (Magyar)

Hidden categories:

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