Configure DNS over HTTPS

With Cloudflare Gateway, you can filter DNS over HTTPS (DoH) requests by location or by user without needing to install the WARP client on your devices.

Location-based policies require that you send DNS requests to a location-specific DoH endpoint, while identity-based policies require that requests include a user-specific DoH token.

​​ Filter DoH requests by location

Location-based policies require that you send DNS requests to a unique DoH endpoint assigned to the location:

https://<YOUR_DOH_SUBDOMAIN>.cloudflare-gateway.com/dns-query

​​ Prerequisites

Obtain your location’s DoH subdomain.

​​ Configure browser for DoH

Browsers can be configured to use any DNS over HTTPS (DoH) endpoint. If you choose to configure DoH directly in your browser, you must choose a Gateway location as your DoH endpoint, otherwise Gateway DNS filtering will not occur in that browser.

Your DNS queries will now be sent to Gateway for filtering. To filter these requests, build a DNS policy using the Location selector.

​​ Filter DoH requests by user

In order to filter DoH queries based on user identity, each query must include a user-specific authentication token. If you have several devices per user and want to apply device-specific policies, you will need to map each device to a different email.

Currently, authentication tokens can only be generated through the API. You can run this interactive Python script which automates the setup procedure, or follow the steps described below.

​​ 1. Create a service token for the account

curl -X POST "https://api.cloudflare.com/client/v4/accounts/<ACCOUNT_ID>/access/service_tokens" \
     -H "X-Auth-Email: <EMAIL>" \
     -H "X-Auth-Key: <API_KEY>" \
     -H "Content-Type: application/json" \
     --data '{"name":"ACME Corporation service token"}'

Save the service token’s client_id, client_secret, and id.

{
  "result": {
    "client_id": "88bf3b6d86161464f6509f7219099e57.access",
    "client_secret": "bdd31cbc4dec990953e39163fbbb194c93313ca9f0a6e420346af9d326b1d2a5",
    "created_at": "2022-06-09T01:59:17Z",
    "expires_at": "2023-06-09T01:59:17Z",
    "id": "f174e90a-fafe-4643-bbbc-4a0ed4fc8415",
    "name": "ACME Corporation service token",
    "updated_at": "2022-06-09T01:59:17Z"
  },
  "success": true,
  "errors": [],
  "messages": []
}

​​ 2. Enable DoH functionality for the service token

curl -X PUT "https://api.cloudflare.com/client/v4/accounts/<ACCOUNT_ID>/access/organizations/doh/<ID>" \
     -H "X-Auth-Email: <EMAIL>" \
     -H "X-Auth-Key: <API_KEY>" \
     -H "Content-Type: application/json" \

If you get an access.api.error.service_token_not_found error, check that <SERVICE_TOKEN_ID> is the value of id and not client_id.

{
  "result": {
    "client_id": "88bf3b6d86161464f6509f7219099e57.access",
    "created_at": "2022-06-09T01:59:17Z",
    "expires_at": "2023-06-09T01:59:17Z",
    "id": "f174e90a-fafe-4643-bbbc-4a0ed4fc8415",
    "name": "ACME Corporation service token",
    "updated_at": "2022-06-09T01:59:17Z",
    "duration": "8760h"
  },
  "success": true,
  "errors": [],
  "messages": []
}

​​ 3. Create a user

Create a new user and optionally add them to a group.

curl -X POST "https://api.cloudflare.com/client/v4/accounts/<ACCOUNT_ID>/access/users" \
     -H "X-Auth-Email: <EMAIL>" \
     -H "X-Auth-Key: <API_KEY>" \
     -H "Content-Type: application/json" \
     --data '{
        "name":"John Doe",
        "email":"jdoe@acme.com",
        "custom": {"groups":[{"id": "02fk6b3p3majl10", "email": "finance@acme.com", "name": "Finance"}]}
        }'

Save the user’s id returned in the response.

{
  "result": {
    "id": "54d425de-7a78-4186-9975-d43c88ee7899",
    "created_at": "2022-03-16T21:18:39.93598Z",
    "updated_at": "2022-05-17T23:50:39.598345Z",
    "uid": "54d425de-7a78-4186-9975-d43c88ee7899",
    "name": "John Doe",
    "email": "jdoe@acme.com",
    "custom": {
        "groups": [
            {
                "email": "finance@acme.com",
                "id": "02fk6b3p3majl10",
                "name": "Finance"
            }
        ]
    }
  },
  "success": true,
  "errors": [],
  "messages": []
}

​​ 4. Generate a DoH token for the user

Request a DoH token for the user, using your service token to authenticate into your team domain.

curl -s -X GET "https://<TEAM_NAME>.cloudflareaccess.com/cdn-cgi/access/doh-token?account-id=<ACCOUNT_ID>&user-id=<USER_ID>&auth-domain=<TEAM_NAME>.cloudflareaccess.com" \
     -H "Cf-Access-Client-Id: <CLIENT_ID>" \
     -H "Cf-Access-Client-Secret: <CLIENT_SECRET>"
     -H "Content-Type: application/json" \

The response contains a unique DoH token associated with the user. This token expires in 24 hours. We recommend setting up a refresh flow for the DoH token instead of generating a new one for every DoH query.

{"token":"y2khbGciOiJSUzI1NiIsImtpZCI6ImJlZjVkYjg4ZTEwMjk3ZDEwNzhkMmEyYjE0MjMxZTljYTQwMjQ2NjAwOTQzNmJhOTQwOGJkODY3ZmI4OWFiOGQifQ.eyJ0eXBlIjoiZG9oIiwiYXVkIjoiY2xvdWRmbGFyZS1nYXRld2F5LmNvbSIsImlhdCI6MTY1NDc1MTg3NSwiZXhwIjoxNjU0ODM4Mjc1LCJhY2NvdW50LWlkIjoiMTA4MDM0OGIyZGYzYmQwN2QxZmI1MjM3Y2Q1ZDU5M2EiLCJ1c2VyLWlkIjoiNTRkNDI1ZGUtN2E3OC00MTg2LTk5NzUtZDQzYzg4ZWU3ODk5In0.I5p4WsH2dPhQ8vwy84zF05PsoBHCsUSXAaMpNhEH36oFZ3tXcs9ksLz7OzpZ_x3HxUfO3n57LlpAF1VehaBt2i94XCkvSgtHpYcwd_qZydLp-BGtcyfU1LbdXQC3m6zxKcIWu5VySi8I-J25UYlpyJhYgZ4DQUZIpqbSSt6WcVRKvA7OBa7xjkTux4OcqWAViO_ZS-GLwl-fqhvolmiwk37seBD3YuV1zG06VeWXfrMkZ5MbhooHD1DZDBHOZpTtmN8MbeKeI4tlY1mb_O3-jE-um6F9Hrl4NQm89MKFzsum-_Rywi5m4PTSlDza7fjdJs7RzFgJd3VWgzG-jgyQKw"}%

​​ 5. Send an authenticated DoH query

Send DoH queries to the resolver at https://<ACCOUNT_ID>.cloudflare-gateway.com/dns-query, making sure to include the user’s DoH token in the CF-Authorization header.

curl -s 'https://<ACCOUNT_ID>.cloudflare-gateway.com/dns-query?name=example.com' \
     -H 'accept: application/dns-json' \
     -H 'CF-Authorization: <USER_DOH_TOKEN>' | jq

If the site is blocked and you have enabled Display block page for the policy, the query will return 162.159.36.12 (the IP address of the Gateway block page). If the block page is disabled, the response will be 0.0.0.0.

{
  "Status": 0,
  "TC": false,
  "RD": true,
  "RA": true,
  "AD": false,
  "CD": false,
  "Question": [
    {
      "name": "example.com",
      "type": 1
    }
  ],
  "Answer": [
    {
      "name": "example.com",
      "type": 1,
      "TTL": 60,
      "data": "162.159.36.12"
    }
  ]
}

You can verify that the request was associated with the correct user email by checking your Gateway DNS logs. To filter these requests, build a DNS policy using any of the Gateway identity-based selectors.