An implementation of RFC 8484 - DNS Queries over HTTPS (DoH). Host your own DoH web service using ASP.NET 7 Runtime that can transform any DNS server to be accessible via the DoH standard protocol.

• Requires .NET 7 installed. Install Hosting Bundle for running on Microsoft IIS web server.
• Windows, Linux and macOS supported.

• Cross-Platform: doh-aspnetcore.zip

• Windows:

1. Download the doh-aspnetcore.zip zip file.
2. Edit the appsettings.json file in notepad to set the DNS server of your choice.
3. Install the DoH app on Windows IIS web server by creating a new website and extracting the doh-aspnetcore.zip zip file into the wwwroot folder of the website.
4. Configure SSL certificate on IIS for the website so that the service works over HTTPS.

Note: You can also run the DNS-over-HTTPS.exe to directly run the DoH console app with built in web server for quick testing.

• Linux:

1. Download and extract doh-aspnetcore.zip zip file to /var/aspnetcore/doh

sudo mkdir -p /var/aspnetcore/doh
cd /var/aspnetcore/doh
sudo wget https://download.technitium.com/doh/doh-aspnetcore.zip
sudo unzip doh-aspnetcore.zip

2. Edit the appsettings.json file in nano to set the DNS server of your choice.

sudo nano appsettings.json

3. Install the DoH app as a systemd daemon:

sudo cp systemd.service /etc/systemd/system/doh.service
sudo systemctl enable doh
sudo systemctl start doh

4. Make sure that the DoH daemon is running without issues by running:

journalctl --unit doh --follow

5. Configure a reverse proxy using a web server like nginx that does the SSL termination for the DoH service. Install the nginx web server using:

sudo apt-get -y install nginx

Create a config file for your domain name at /etc/nginx/sites-enabled/doh.example.com with the config shown below. Save the certificate and key files to path given as in the config.

server {
    listen 443 ssl;
    server_name doh.example.com;

    ssl_certificate /etc/nginx/ssl/doh-server.crt;
    ssl_certificate_key /etc/nginx/ssl/doh-server.key;

    location / {
        proxy_pass http://127.0.0.1:8053;
    }
}

Reload nginx web server to finish the configuration.

sudo service nginx reload

Note: You can also run dotnet DNS-over-HTTPS.dll command to directly run the DoH console app for quick testing.

The DoH service is available on the /dns-query location on the web site that you are running. If you are running it directly as a console app then your DoH end point URL will be http://localhost:5000/dns-query. For Linux systemd daemon, the DoH end point will be http://localhost:8053/dns-query as per the argument provided in the systemd.service file.

Configuring DNS-over-TLS and DNS-over-HTTPS with any DNS Server

For support, send an email to [email protected]. For any issues, feedback, or feature request, create an issue on GitHub.

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