A Comprehensive Guide to Using dnscrypt-proxy on Linux in 2024

Are you concerned about your online privacy and the security of your DNS queries? Do you want to prevent your ISP or other third parties from snooping on your internet activity? If so, it‘s time to take a closer look at dnscrypt-proxy – a powerful tool for encrypting your DNS traffic and keeping your browsing habits confidential.

In this in-depth guide, we‘ll walk you through everything you need to know about dnscrypt-proxy on Linux systems. From installation and configuration to advanced use cases and troubleshooting, you‘ll come away with a solid understanding of how to leverage this valuable open-source utility. Let‘s dive in!

What is dnscrypt-proxy?

At its core, dnscrypt-proxy is a DNS proxy with support for encrypted DNS protocols. It acts as an intermediary between your device and a remote DNS resolver, ensuring that all DNS queries are securely encrypted before leaving your network.

Why is this important? By default, most DNS queries are sent in plain text over an unencrypted connection. This means that anyone with access to your network traffic (like your ISP, government agencies, or malicious actors) can easily see which websites you‘re visiting and when. DNS encryption helps mitigate this privacy risk by making it much harder for outsiders to intercept and analyze your DNS queries.

dnscrypt-proxy supports several different DNS encryption protocols, including:

• DNSCrypt: An open specification for securing communications between a client and a DNS resolver, using high-speed high-security elliptic-curve cryptography.
• DNS over HTTPS (DoH): A protocol for performing DNS resolution via the HTTPS protocol, providing increased security and privacy compared to plain text DNS.
• DNS over TLS (DoT): Similar to DoH but uses TLS instead of HTTPS for transport security.
• Anonymized DNSCrypt: Routes encrypted DNS queries through an anonymizing network like Tor for even greater privacy.

By leveraging one or more of these protocols, dnscrypt-proxy helps keep your DNS traffic safe from prying eyes and potential manipulations. But how do you actually set it up and configure it on a Linux system? Read on to find out.

Installing dnscrypt-proxy on Linux

The process of installing dnscrypt-proxy varies slightly depending on your Linux distribution, but it‘s generally quite straightforward. Most major distros offer dnscrypt-proxy through their standard package repositories.

On Debian/Ubuntu:

sudo apt update
sudo apt install dnscrypt-proxy

On Fedora:

sudo dnf install dnscrypt-proxy

On Arch Linux:

sudo pacman -S dnscrypt-proxy

If your distribution doesn‘t provide an official package, you can also download the latest release directly from the dnscrypt-proxy GitHub page and compile it from source. Check the project‘s README file for detailed compilation instructions.

Once installed, you‘ll need to configure dnscrypt-proxy to use your desired DNS resolver and encryption settings. The default configuration file is usually located at /etc/dnscrypt-proxy/dnscrypt-proxy.toml – open this in your favorite text editor.

Some key settings to look for:

• server_names: A list of one or more DNS resolver names to use. You can find a list of public DNSCrypt/DoH/DoT resolvers at https://dnscrypt.info/public-servers
• listen_addresses: The local IP address(es) and port(s) on which dnscrypt-proxy should listen for incoming DNS queries. The default is 127.0.0.1:53 (which only listens on localhost).
• daemonize: Set to "true" to run dnscrypt-proxy as a background daemon
• require_dnssec: Set to "true" to require DNSSEC validation of responses (recommended)

Here‘s an example minimal configuration using Cloudflare‘s DNS resolver:

server_names = [‘cloudflare‘]
listen_addresses = [‘127.0.0.1:53‘]

[sources]
  [sources.‘public-resolvers‘]
  urls = [‘https://raw.githubusercontent.com/DNSCrypt/dnscrypt-resolvers/master/v3/public-resolvers.md‘, ‘https://download.dnscrypt.info/resolvers-list/v3/public-resolvers.md‘]
  cache_file = ‘public-resolvers.md‘
  minisign_key = ‘RWQf6LRCGA9i53mlYecO4IzT51TGPpvWucNSCh1CBM0QTaLn73Y7GFO3‘
  refresh_delay = 72
  prefix = ‘‘

Save the file and start the dnscrypt-proxy service:

sudo systemctl start dnscrypt-proxy

To make it start automatically on boot:

sudo systemctl enable dnscrypt-proxy

At this point, dnscrypt-proxy should be up and running, listening for DNS queries on localhost and forwarding them to the configured resolver over an encrypted connection. But there‘s one more step needed to make sure ALL your system‘s DNS queries go through dnscrypt-proxy, and that‘s where systemd-resolved comes in.

Using dnscrypt-proxy with systemd-resolved

On many modern Linux distributions, a service called systemd-resolved is responsible for handling system-wide DNS configuration. By default, it may ignore dnscrypt-proxy and send queries directly to your configured DNS servers, bypassing the encrypted tunnel.

To fix this, we need to tell systemd-resolved to forward all DNS queries to dnscrypt-proxy instead. Here‘s how:

1. Open the systemd-resolved configuration file in your editor:

sudo nano /etc/systemd/resolved.conf

2. Add the following line to the [Resolve] section:

DNSStubListener=no

This disables the local DNS stub resolver, so systemd-resolved will no longer listen for DNS queries itself.

3. Save the file and restart systemd-resolved:

sudo systemctl restart systemd-resolved

4. Next, open the NetworkManager configuration file:

sudo nano /etc/NetworkManager/NetworkManager.conf 

Add the following line to the [main] section:

dns=none

This tells NetworkManager not to touch resolv.conf, so your manual DNS configuration won‘t get overwritten.

5. Finally, edit /etc/resolv.conf to point to dnscrypt-proxy‘s listening address:

nameserver 127.0.0.1
options edns0

The "options edns0" line enables EDNS0 extensions, which are required for DNSSEC validation and other advanced DNS features.

6. Restart NetworkManager:

sudo systemctl restart NetworkManager

Now all your system‘s DNS queries should be routed through dnscrypt-proxy, giving you the full benefit of encrypted DNS resolution. You can verify this by running a DNS lookup and checking that the server field shows 127.0.0.1:

$ dig google.com

; <<>> DiG 9.11.3-1ubuntu1.11-Ubuntu <<>> google.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 29319
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1452
;; QUESTION SECTION:
;google.com.            IN  A

;; ANSWER SECTION:
google.com.     197 IN  A   172.217.16.142

;; Query time: 35 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Thu Feb 06 09:25:19 PST 2020
;; MSG SIZE  rcvd: 65

Troubleshooting tips

Even with proper installation and configuration, you may occasionally run into issues with dnscrypt-proxy. Here are a few common problems and how to resolve them:

• dnscrypt-proxy fails to start

  • Check the logs for error messages: sudo journalctl -u dnscrypt-proxy
  • Make sure your config file syntax is valid and all necessary options are set
  • Verify that the configured listen port(s) are not already in use by another process

• DNS queries are not being encrypted

  • Confirm that dnscrypt-proxy is running: sudo systemctl status dnscrypt-proxy
  • Check that your system‘s /etc/resolv.conf points to 127.0.0.1
  • Ensure that no other local DNS services (like dnsmasq or unbound) are overriding dnscrypt-proxy
  • Review the dnscrypt-proxy logs for errors indicating a failure to connect to the upstream resolver

• Certain domains fail to resolve

  • Make sure your upstream resolver is reliable and not blocking any queries
  • Check if the domain has DNSSEC enabled; if so, ensure dnscrypt-proxy is configured to validate DNSSEC responses
  • Try temporarily disabling EDNS0 options in /etc/resolv.conf to rule out MTU-related issues

• Performance seems slow

  • Measure your query speeds with an ./dnscrypt-proxy -resolve mysite.com to see if latency is due to dnscrypt-proxy or the upstream resolver
  • Consider using a geographically closer resolver to minimize round-trip time
  • Ensure your system has adequate free memory and CPU resources to handle the encryption overhead

In most cases, careful review of the configuration settings and service states will reveal the underlying cause of any problems. Don‘t hesitate to consult the dnscrypt-proxy documentation or reach out to the community for further assistance.

Advanced usage

While the basic setup steps will suffice for most users, there are many ways to customize and extend dnscrypt-proxy for more advanced use cases. A few possibilities worth exploring:

• Specifying multiple resolvers for redundancy and failover
• Filtering queries based on predefined allow/deny lists
• Logging and monitoring query metrics for analysis
• Enabling automatic updates of resolver lists
• Building custom resolvers with your own DNSSEC keys
• Containerizing dnscrypt-proxy with Docker for easier deployment

See the official documentation (link) for details on these and other advanced features. With a little extra configuration, you can turn dnscrypt-proxy into an incredibly powerful and flexible DNS security solution.

Alternatives and the future

Of course, dnscrypt-proxy is not the only tool available for encrypting DNS traffic. Some popular alternatives include:

• Stubby – An application that acts as a local DNS Privacy stub resolver, using DoT to encrypt queries
• Unbound – A full-featured recursive DNS resolver with support for DNS over TLS
• dnsmasq – A lightweight DNS forwarder and DHCP server, often used in combination with dnscrypt-proxy

However, I believe dnscrypt-proxy remains one of the most robust and flexible solutions, especially for power users who value customization. Its support for multiple encryption protocols, extensive configuration options, and active development make it a top choice.

Looking ahead, the dnscrypt-proxy project shows no signs of slowing down. Recent releases have added support for the latest DNS encryption standards, as well as performance optimizations and bug fixes. The developers are committed to keeping pace with the evolving DNS security landscape.

Additionally, there is growing awareness of the importance of encrypting DNS traffic, as more and more internet users prioritize privacy and data protection. This trend bodes well for the future of projects like dnscrypt-proxy.

As long as there is a need for secure, confidential DNS resolution, dnscrypt-proxy will have a role to play. And with ongoing development and a supportive community behind it, I expect dnscrypt-proxy to remain a vital tool for Linux users well into 2024 and beyond.

Conclusion

In this guide, we‘ve taken a comprehensive look at dnscrypt-proxy and how it can dramatically enhance the privacy and security of your DNS queries on Linux.

We covered the importance of DNS encryption, the installation and configuration process on various distributions, integration with systemd-resolved, troubleshooting common issues, advanced usage tips, and even touched on some alternative tools and the future outlook of the project.

Hopefully you now feel empowered to implement dnscrypt-proxy in your own environment and start reaping the benefits of encrypted DNS. It may seem like a small change, but the peace of mind that comes with knowing your DNS queries are safe from snooping is truly priceless.

So go ahead and give dnscrypt-proxy a try – your privacy will thank you! And as always, feel free to reach out with any questions or feedback. Stay safe out there!