README
¶
DNS-over-HTTPS
Client and server software to query DNS over HTTPS, using Google DNS-over-HTTPS protocol and IETF DNS-over-HTTPS (RFC 8484).
Guide
Tutorial to setup your own DNS-over-HTTPS (DoH) server. (Thanks to Antoine Aflalo)
Installing
Install Go, at least version 1.10.
(Note for Debian/Ubuntu users: You need to set $GOROOT if you could not get your new version of Go selected by the Makefile.)
First create an empty directory, used for $GOPATH:
mkdir ~/gopath
export GOPATH=~/gopath
To build the program, type:
make
To install DNS-over-HTTPS as Systemd services, type:
sudo make install
By default, Google DNS over HTTPS is used. It should work for most users (except for People's Republic of China). If you need to modify the default settings, type:
sudoedit /etc/dns-over-https/doh-client.conf
To automatically start DNS-over-HTTPS client as a system service, type:
sudo systemctl start doh-client.service
sudo systemctl enable doh-client.service
Then, modify your DNS settings (usually with NetworkManager) to 127.0.0.1.
To test your configuration, type:
dig www.google.com
If it is OK, you will see:
;; SERVER: 127.0.0.1#53(127.0.0.1)
Uninstalling
To uninstall, type:
sudo make uninstall
The configuration files are kept at /etc/dns-over-https. Remove them manually if you want.
Server Configuration
The following is a typical DNS-over-HTTPS architecture:
+--------------+ +------------------------+
| Application | | Recursive DNS Server |
+-------+------+ +-----------+------------+
| |
+-------+------+ +-----------+------------+
| Client side | | doh-server |
| cache (nscd) | +-----------+------------+
+-------+------+ |
| +--------------------------+ +-----------+------------+
+-------+------+ | HTTP cache server / | | HTTP service muxer |
| doh-client +--+ Content Delivery Network +--+ (Apache, Nginx, Caddy) |
+--------------+ +--------------------------+ +------------------------+
Although DNS-over-HTTPS can work alone, a HTTP service muxer would be useful as you can host DNS-over-HTTPS along with other HTTPS services.
HTTP/2 with at least TLS v1.3 is recommended. OCSP stapling must be enabled, otherwise DNS recursion may happen.
Configuration file
The main configuration file is doh-client.conf.
Server selectors. If several upstream servers are set, one is selected according to upstream_selector for each request. With upstream_selector = "random", a random upstream server will be chosen for each request.
# available selector: random (default) or weighted_round_robin or lvs_weighted_round_robin
upstream_selector = "random"
Example configuration: Apache
SSLProtocol TLSv1.2
SSLHonorCipherOrder On
SSLCipherSuite ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:ECDH+3DES:DH+3DES:RSA+3DES:!aNULL:!MD5:!DSS:!eNULL:!EXP:!LOW:!MD5
SSLUseStapling on
SSLStaplingCache shmcb:/var/lib/apache2/stapling_cache(512000)
<VirtualHost *:443>
ServerName MY_SERVER_NAME
Protocols h2 http/1.1
ProxyPass /dns-query http://[::1]:8053/dns-query
ProxyPassReverse /dns-query http://[::1]:8053/dns-query
</VirtualHost>
(Credit: Joan Moreau)
Example configuration: Nginx
server {
listen 443 ssl http2 default_server;
listen [::]:443 ssl http2 default_server;
server_name MY_SERVER_NAME;
server_tokens off;
ssl_protocols TLSv1.2 TLSv1.3; # TLS 1.3 requires nginx >= 1.13.0
ssl_prefer_server_ciphers on;
ssl_dhparam /etc/nginx/dhparam.pem; # openssl dhparam -dsaparam -out /etc/nginx/dhparam.pem 4096
ssl_ciphers EECDH+AESGCM:EDH+AESGCM;
ssl_ecdh_curve secp384r1; # Requires nginx >= 1.1.0
ssl_session_timeout 10m;
ssl_session_cache shared:SSL:10m;
ssl_session_tickets off; # Requires nginx >= 1.5.9
ssl_stapling on; # Requires nginx >= 1.3.7
ssl_stapling_verify on; # Requires nginx => 1.3.7
ssl_early_data off; # 0-RTT, enable if desired - Requires nginx >= 1.15.4
resolver 1.1.1.1 valid=300s; # Replace with your local resolver
resolver_timeout 5s;
# HTTP Security Headers
add_header X-Frame-Options DENY;
add_header X-Content-Type-Options nosniff;
add_header X-XSS-Protection "1; mode=block";
add_header Strict-Transport-Security "max-age=63072000";
ssl_certificate /path/to/your/server/certificates/fullchain.pem;
ssl_certificate_key /path/to/your/server/certificates/privkey.pem;
location /dns-query {
proxy_pass http://localhost:8053/dns-query;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
}
}
(Credit: Cipherli.st)
Example configuration: Caddy
https://MY_SERVER_NAME {
log / syslog "{remote} - {user} [{when}] \"{method} {scheme}://{host}{uri} {proto}\" {status} {size} \"{>Referer}\" \"{>User-Agent}\" {>X-Forwarded-For}"
errors syslog
gzip
proxy /dns-query http://[::1]:18053 {
header_upstream Host {host}
header_upstream X-Real-IP {remote}
header_upstream X-Forwarded-For {>X-Forwarded-For},{remote}
header_upstream X-Forwarded-Proto {scheme}
}
root /var/www
tls {
ciphers ECDHE-ECDSA-WITH-CHACHA20-POLY1305 ECDHE-RSA-WITH-CHACHA20-POLY1305 ECDHE-ECDSA-AES256-GCM-SHA384 ECDHE-RSA-AES256-GCM-SHA384 ECDHE-ECDSA-AES128-GCM-SHA256 ECDHE-RSA-AES128-GCM-SHA256
curves X25519 p384 p521
must_staple
}
}
DNSSEC
DNS-over-HTTPS is compatible with DNSSEC, and requests DNSSEC signatures by
default. However signature validation is not built-in. It is highly recommended
that you install unbound or bind and pass results for them to validate DNS
records.
EDNS0-Client-Subnet (GeoDNS)
DNS-over-HTTPS supports EDNS0-Client-Subnet protocol, which submits part of the client's IP address (/24 for IPv4, /56 for IPv6 by default) to the upstream server. This is useful for GeoDNS and CDNs to work, and is exactly the same configuration as most public DNS servers.
Keep in mind that /24 is not enough to track a single user, although it is
precise enough to know the city where the user is located. If you think
EDNS0-Client-Subnet is affecting your privacy, you can set no_ecs = true in
/etc/dns-over-https/doh-client.conf, with the cost of slower video streaming
or software downloading speed.
To ultilize ECS, X-Forwarded-For or X-Real-IP should be enabled on your
HTTP service muxer. If your server is backed by unbound or bind, you
probably want to configure it to enable the EDNS0-Client-Subnet feature as
well.
Protocol compatibility
Google DNS-over-HTTPS Protocol
DNS-over-HTTPS uses a protocol compatible to Google DNS-over-HTTPS, except for absolute expire time is preferred to relative TTL value. Refer to json-dns/response.go for a complete description of the API.
IETF DNS-over-HTTPS Protocol
DNS-over-HTTPS uses a protocol compatible to IETF DNS-over-HTTPS (RFC 8484).
Supported features
Currently supported features are:
- IPv4 / IPv6
- EDNS0 large UDP packet (4 KiB by default)
- EDNS0-Client-Subnet (/24 for IPv4, /56 for IPv6 by default)
The name of the project
This project is named "DNS-over-HTTPS" because it was written before the IETF DoH project. Although this project is compatible with IETF DoH, the project is not affiliated with IETF.
To avoid confusion, you may also call this project "m13253/DNS-over-HTTPS" or anything you like.
License
DNS-over-HTTPS is licensed under the MIT License. You are encouraged to embed DNS-over-HTTPS into your other projects, as long as the license permits.
You are also encouraged to disclose your improvements to the public, so that others may benefit from your modification, in the same way you receive benefits from this project.
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