Domain Connect Protocol - DNS provisioning between Services and DNS Providers
draft-kowalik-domainconnect-00
| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Authors | Paweł Kowalik , A Blinn , Jody Kolker , S Kerola | ||
| Last updated | 2024-10-21 (Latest revision 2024-10-20) | ||
| Replaces | draft-kowalik-regext-domainconnect | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | Proposed Standard | ||
| Formats | |||
| Reviews |
HTTPDIR Early Review due 2024-12-01
Incomplete
|
||
| Additional resources |
Additional Web Page
GitHub Repository Mailing List |
||
| Stream | WG state | (None) | |
| Document shepherd | Peter Thomassen | ||
| IESG | IESG state | Publication Requested::Revised I-D Needed | |
| Action Holders | |||
| Consensus boilerplate | Yes | ||
| Telechat date | (None) | ||
| Responsible AD | Orie Steele | ||
| Send notices to | peter@desec.io |
draft-kowalik-domainconnect-00
Network Working Group P. Kowalik
Internet-Draft DENIC eG
Intended status: Standards Track A. Blinn
Expires: 23 April 2025
J. Kolker
GoDaddy Inc.
S. Kerola
Cloudflare, Inc.
20 October 2024
Domain Connect Protocol - DNS provisioning between Services and DNS
Providers
draft-kowalik-domainconnect-00
Abstract
This document provides specification of the Domain Connect Protocol
that was built to support DNS configuration provisioning between
Service Providers (hosting, social, email, hardware, etc.) and DNS
Providers.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 23 April 2025.
Copyright Notice
Copyright (c) 2024 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
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and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 3
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Protocol design . . . . . . . . . . . . . . . . . . . . . . . 5
4.1. Templates . . . . . . . . . . . . . . . . . . . . . . . . 5
5. End User Flows . . . . . . . . . . . . . . . . . . . . . . . 6
5.1. General information . . . . . . . . . . . . . . . . . . . 6
5.2. The Synchronous Flow . . . . . . . . . . . . . . . . . . 6
5.3. The Asynchronous Flow . . . . . . . . . . . . . . . . . . 9
6. DNS Provider Discovery . . . . . . . . . . . . . . . . . . . 9
7. Applying Domain Connect . . . . . . . . . . . . . . . . . . . 13
7.1. Endpoints . . . . . . . . . . . . . . . . . . . . . . . . 14
7.2. Synchronous Flow . . . . . . . . . . . . . . . . . . . . 14
7.2.1. Query Supported Template . . . . . . . . . . . . . . 14
7.2.2. Apply Template . . . . . . . . . . . . . . . . . . . 15
7.2.3. Security Considerations . . . . . . . . . . . . . . . 19
7.2.4. Shared Templates . . . . . . . . . . . . . . . . . . 21
7.2.5. Verification of Changes . . . . . . . . . . . . . . . 22
7.3. Asynchronous Flow: OAuth . . . . . . . . . . . . . . . . 22
7.3.1. General information . . . . . . . . . . . . . . . . . 23
7.3.2. OAuth Flow: Setup . . . . . . . . . . . . . . . . . . 23
7.3.3. OAuth Flow: Getting an Authorization Code . . . . . . 23
7.3.4. OAuth Flow: Requesting an Access Token . . . . . . . 27
7.3.5. OAuth Flow: Making Requests with Access Tokens . . . 30
7.3.6. OAuth Flow: Apply Template to Domain. . . . . . . . . 31
7.3.7. OAuth Flow: Revert Template . . . . . . . . . . . . . 35
7.3.8. OAuth Flow: Revoking access . . . . . . . . . . . . . 36
8. Domain Connect Objects and Templates . . . . . . . . . . . . 36
8.1. Template Versioning . . . . . . . . . . . . . . . . . . . 37
8.2. Template Definition . . . . . . . . . . . . . . . . . . . 37
8.3. Template Record . . . . . . . . . . . . . . . . . . . . . 41
9. Template Considerations . . . . . . . . . . . . . . . . . . . 49
9.1. Template State in DNS . . . . . . . . . . . . . . . . . . 49
9.2. Disclosure of Changes and Conflicts . . . . . . . . . . . 49
9.3. Record Types and Conflicts . . . . . . . . . . . . . . . 51
9.4. Apply, Re-apply, and Multi-Instance . . . . . . . . . . . 51
9.5. Non-essential records . . . . . . . . . . . . . . . . . . 52
9.6. Template Scope . . . . . . . . . . . . . . . . . . . . . 52
9.7. Host/Name in Template . . . . . . . . . . . . . . . . . . 52
9.8. PointsTo in Template . . . . . . . . . . . . . . . . . . 53
9.9. Variables . . . . . . . . . . . . . . . . . . . . . . . . 53
9.9.1. Variables and Host/Name in Template . . . . . . . . . 53
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9.9.2. Variable Values . . . . . . . . . . . . . . . . . . . 54
9.9.3. Variables and Security . . . . . . . . . . . . . . . 55
9.9.4. Variable Examples . . . . . . . . . . . . . . . . . . 55
9.10. SPF TXT Record . . . . . . . . . . . . . . . . . . . . . 56
9.10.1. What is SPF? . . . . . . . . . . . . . . . . . . . . 56
9.10.2. Multiple Services . . . . . . . . . . . . . . . . . 56
9.10.3. SPF Record Merging . . . . . . . . . . . . . . . . . 57
9.10.4. Alternatives . . . . . . . . . . . . . . . . . . . . 59
9.11. Public Template Repository . . . . . . . . . . . . . . . 59
9.11.1. General information . . . . . . . . . . . . . . . . 59
9.11.2. Repository Location . . . . . . . . . . . . . . . . 59
9.11.3. File naming requirements . . . . . . . . . . . . . . 59
9.11.4. Template Integrity . . . . . . . . . . . . . . . . . 60
10. General considerations . . . . . . . . . . . . . . . . . . . 60
10.1. Onboarding . . . . . . . . . . . . . . . . . . . . . . . 60
10.2. Case Sensitivity . . . . . . . . . . . . . . . . . . . . 60
11. Extensions/Exclusions . . . . . . . . . . . . . . . . . . . . 61
11.1. General information . . . . . . . . . . . . . . . . . . 61
11.2. APEXCNAME . . . . . . . . . . . . . . . . . . . . . . . 61
11.3. Redirection . . . . . . . . . . . . . . . . . . . . . . 61
11.4. Nameservers . . . . . . . . . . . . . . . . . . . . . . 62
11.5. DS (DNSSEC) . . . . . . . . . . . . . . . . . . . . . . 62
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 62
Implementation Status . . . . . . . . . . . . . . . . . . . . . . 63
Change History . . . . . . . . . . . . . . . . . . . . . . . . . 63
Normative References . . . . . . . . . . . . . . . . . . . . . . 64
Informative References . . . . . . . . . . . . . . . . . . . . . 65
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 65
A.1. Example Template . . . . . . . . . . . . . . . . . . . . 65
A.2. Example Records: Single static host record . . . . . . . 66
A.3. Example Records: Single variable host record for A . . . 67
A.4. Example Records: Unspecified record type CAA . . . . . . 67
A.5. Example: DNS Zone merging . . . . . . . . . . . . . . . . 68
A.6. Example: SPF Record Merging . . . . . . . . . . . . . . . 69
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 71
1. Acknowledgements
The authors wish to thank the following persons for their feedback
and suggestions as well as for the previous work on the standard:
* Roger Carney of GoDaddy Inc.
* Chris Ambler of GoDaddy Inc.
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2. Introduction
Configuring a service at a Service Provider to work with a domain has
historically been a complex task that is difficult for users.
Typically, a customer would try to configure their service by
entering their domain name with the Service Provider. The Service
Provider then used a number of techniques with mixed reliability to
discover the DNS Provider. This might include DNS queries for
nameservers, queries to whois, and mapping tables to determine the
registrar or the company providing DNS.
Once the Service Provider discovered the DNS Provider, they typically
gave the customer instructions for proper configuration of DNS. This
might include help text, screen shots, or even links to the
appropriate tools.
Discovery of the DNS Provider in this manner is unreliable, and
providing instructions to users would present a number of
technologies (DNS record types, TTLs, Hostnames, etc.) and processes
they didn't understand. These instructions authored by the Service
Provider often quickly become out of date, further confusing the
issue for users.
The goal of this specificatoin is to create a system where Service
Providers can easily enable their applications/services to work with
the domain names of their customers. This includes both discovery of
the DNS Provider and subsequent modification of DNS.
The system will be implemented using simple web based interactions
and standard authentication protocols. The creation and modification
of DNS settings will be done through the application of templates
instead of direct manipulation of individual DNS records.
3. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
Service Providers refers to entities that provide products and
services attached to domain names. Examples include web hosting
providers (such as Wix or SquareSpace), email Service Providers
(such as Microsoft or Google) and potentially even hardware
manufacturers with DNS-enabled devices like home routers or
automation controls (such as Linksys, Nest, and Philips).
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DNS Providers refers to entities that provide DNS services such as
registrars (such as GoDaddy or 1and1) or standalone DNS services
(like Cloudflare).
Registrar refers to entities that register domain names with
registries. It is noted that the DNS Provider and Registrar can
be different entities for a given domain name and DNS Zone.
Customer/User refers to the end-user of these services.
Templates/Service Templates refers to a file that describes a set of
changes to DNS and domain functionality to enable a specific
service.
Public Template Repository refers to a public repository of
Templates in a standarised format (read more: Section 9.11).
Root Domain refers to a registered domain (e.g. example.com or
example.co.uk), or to a delegated zone in DNS.
Sub Domain refers to a sub-domain of a root domain (e.g.
sub.example.com or sub.example.co.uk).
4. Protocol design
4.1. Templates
Templates are core to Domain Connect, as they fully describe a
service owned by a Service Provider and contain all of the
information necessary to enable and operate/maintain the service in
the form of a set of records.
The individual records in a template may be identified by a groupId.
This allows for the application of templates in different stages.
For example, an email provider might first set a TXT record to verify
the domain, and later set an MX record to configure email delivery.
While done separately, both changes are fundamentally part of the
same service.
Templates may also contain variable portions, as often values of data
in DNS change based on the implementation and/or user of the service
(e.g. the IP address of a service, a customer id, etc.).
The template is defined by the Service Provider and manually
onboarded with the DNS Provider, according to a template definition
published in the Public Repository (Section 9.11) or agreed out-of-
band between the Service Provider and the DNS Provider.
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By basing the protocol on templates instead of DNS Records, several
advantages are achieved. The DNS Provider has very explicit
knowledge and control of the settings being changed to enable a
service. And the system is more secure as templates are controlled
and contained.
5. End User Flows
5.1. General information
To attach a domain name to a service provided by a Service Provider,
the customer would first enter their domain name.
Instead of relying on examination of the nameservers and mapping
these to DNS Providers, DNS Provider discovery is handled through
simple records in DNS and an API. The Service Provider queries for a
specific record in the zone that returns a REST endpoint to initiate
the protocol. When this endpoint is called, a Domain Connect
compliant DNS Provider returns information about that domain and how
to configure it using Domain Connect.
To apply the changes to DNS, there are two use cases. The first is a
synchronous web flow, and the second is an asynchronous flow using
OAuth and an API.
It is noted that a DNS Provider may choose to only implement one of
the flows. As a matter of practice many Service Providers are based
on the synchronous flow, with only a handful of them based on the
asynchronous OAuth flow. So many DNS providers may opt to only
implement the synchronous flow.
It is also be noted that individual services may work with the
synchronous flow only, the asynchronous flow only, or with both.
5.2. The Synchronous Flow
This flow is tailored for the Service Provider that requires a one
time synchronous change to DNS.
The user first enters their domain name at the Service Provider
website.
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+-----------------------------------------------+
| https://acmewebsiteserviceprovider.example |
+-----------------------------------------------+
| ACME Web Site Service Provider |
| |
| Please enter the domain you wish to enable |
| with your Acme Website and click Next |
| |
| +-------------------------------+ |
| Domain Name | | |
| +-------------------------------+ |
| |
| +-----------------------+ |
| | Next | |
| +-----------------------+ |
| |
+-----------------------------------------------+
Figure 1: Service Provider domain input
After the Service Provider determines the DNS Provider using
discovery, the Service Provider should display a link to the user
indicating that they can "Connect their Domain" to the service.
+-----------------------------------------------+
| https://acmewebsiteserviceprovider.example |
+-----------------------------------------------+
| ACME Web Site Service Provider |
| |
| It looks like the domain "example.com" is |
| currently at Virtucon Domains. To configure |
| this domain to work with Acme Website, click |
| Next. |
| +-----------------------+ |
| | Next | |
| +-----------------------+ |
| |
+-----------------------------------------------+
Figure 2: Service Provider displays discovery results and offers
setup with a DNS provider
After clicking the link, the user is directed to a browser window on
the DNS Provider's site. This may be done in another tab or in a new
browser window, but may also be an in place navigation with a return
url. This link passes the domain name being modified, the service
provider/template being enabled, and any additional parameters
(variables) needed to apply the template and configure the service.
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Once at the DNS Provider site, the user is asked to authenticate if
necessary.
+-----------------------------------------------+
| https://virtucondomains.example |
+-----------------------------------------------+
| Virtucon Domains |
| |
| Please sign in to Virtucon domains |
| |
| +-------------------------+ |
| Login |user@xyz.example | |
| +-------------------------+ |
| |
| +-------------------------+ |
| Password |****** | |
| +-------------------------+ |
| |
| +-----------------------+ |
| | Next | |
| +-----------------------+ |
| |
+-----------------------------------------------+
Figure 3: DNS provider user authentication
After authenticating at the DNS Provider, the DNS Provider must
verify the DNS zone of the domain name is controlled by the user.
The DNS Provider must verify other parameters passed in are valid,
and must prompt the user for consent to make the changes to DNS. The
DNS Provider may also warn the user of services that would be
disabled by applying this change to DNS.
+-----------------------------------------------+
| https://virtucondomains.example |
+-----------------------------------------------+
| Virtucon Domains |
| |
| ACME would like to make your domain |
| example.com work with ACME Web Sites. |
| |
| Click Confirm to make the changes or Cancel |
| |
| +-----------------+ +-----------------+ |
| | Confirm | | Cancel | |
| +-----------------+ +-----------------+ |
| |
+-----------------------------------------------+
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Figure 4: User authorization at the DNS provider of the DNS setup
for ACME
Assuming the user grants this consent, the DNS changes are be
applied.
If invoked in a pop-up window or tab, the browser window should be
closed after the changes are applied. If invoked in place, the user
must be navigated back to the Service Provider after the changes are
applied.
5.3. The Asynchronous Flow
The asynchronous OAuth flow is tailored for the Service Provider that
wishes to make changes to DNS asynchronously with respect to the user
interaction, or wishes to make multiple or additional changes to DNS
over time.
The asynchronous flow begins similarly to the synchronous flow. The
Service Provider determines the DNS Provider and links to a consent
dialog at the DNS Provider. Once at the DNS Provider the user signs
in, control of the DNS zone for the domain is verified, and consent
is granted.
Instead of applying the DNS changes on user consent, OAuth access is
granted to the Service Provider. An OAuth access code is generated
and handed back to the Service Provider. The Service Provider then
requests an access (bearer) token.
The permission granted in the OAuth token is a right for the Service
Provider to apply a requested template (or templates) to the specific
domain (and specific subdomains) DNS under control of a specific user
at the DNS Provider.
The Service Provider would later call the API of the DNS provider to
apply a template using the access token.
Additional parameters must be passed as name/value pairs when
applying the template.
6. DNS Provider Discovery
To facilitate discovery of the DNS Provider from a domain name DNS is
utilized. This is done by returning a TXT record for
__domainconnect_ in the zone.
An example of the contents of this record:
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domainconnect.virtucondomains.example
As a practical matter of implementation, the DNS Provider may or may
not contain a copy of this data in each and every zone. Instead, the
DNS Provider must simply respond to the DNS query for the
__domainconnect_ TXT record with the appropriate data.
How this is implemented is up to the DNS Provider.
For example, the DNS Provider may not store the data inside a TXT
record for the domain, opting instead to put a CNAME in the zone and
have the TXT record in the target of the CNAME. Another DNS Provider
may simply respond with the appropriate records at the DNS layer
without having the data in each zone.
The URL prefix returned is subsequently used by the Service Provider
to determine the additional settings for using Domain Connect on this
domain at the DNS Provider. This is done by calling a REST API.
GET
https://{_domainconnect}/v2/{domain}/settings
This must return a JSON structure containing the settings to use for
Domain Connect on the domain name (passed in on the path) at the DNS
Provider. This JSON structure must contain the following fields
unless otherwise specified.
+==============+=====================+========+=====================+
| *Field* | *Key* | *Type* | *Description* |
+==============+=====================+========+=====================+
| *Provider | providerId | String | (REQUIRED) Unique |
| Id* | | | identifier for the |
| | | | DNS Provider. To |
| | | | ensure non- |
| | | | coordinated |
| | | | uniqueness, this |
| | | | should be the |
| | | | domain name of the |
| | | | DNS Provider (e.g. |
| | | | virtucom.example). |
+--------------+---------------------+--------+---------------------+
| *Provider | providerName | String | (REQUIRED) The |
| Name* | | | name of the DNS |
| | | | Provider. |
+--------------+---------------------+--------+---------------------+
| *Provider | providerDisplayName | String | (OPTIONAL) The |
| Display | | | name of the DNS |
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| Name* | | | Provider that |
| | | | should be |
| | | | displayed by the |
| | | | Service Provider. |
| | | | This may change |
| | | | per domain for |
| | | | some DNS Providers |
| | | | that power |
| | | | multiple brands. |
+--------------+---------------------+--------+---------------------+
| *UX URL | urlSyncUX | String | (OPTIONAL) The URL |
| Prefix for | | | Prefix for linking |
| Synchronous | | | to the UX of |
| Flows* | | | Domain Connect for |
| | | | the synchronous |
| | | | flow at the DNS |
| | | | Provider. If not |
| | | | returned, the DNS |
| | | | Provider is not |
| | | | supporting the |
| | | | synchronous flow |
| | | | on this domain. |
+--------------+---------------------+--------+---------------------+
| *UX URL | urlAsyncUX | String | (OPTIONAL) The URL |
| Prefix for | | | Prefix for linking |
| Asynchronous | | | to the UX elements |
| Flows* | | | of Domain Connect |
| | | | for the |
| | | | asynchronous flow |
| | | | at the DNS |
| | | | Provider. If not |
| | | | returned, the DNS |
| | | | Provider is not |
| | | | supporting the |
| | | | asynchronous flow |
| | | | on this domain. |
+--------------+---------------------+--------+---------------------+
| *API URL | urlAPI | String | (REQUIRED) The URL |
| Prefix* | | | Prefix for the |
| | | | REST API |
+--------------+---------------------+--------+---------------------+
| *Width of | width | Number | (OPTIONAL) This is |
| Window* | | | the desired width |
| | | | of the window for |
| | | | granting consent |
| | | | when navigated in |
| | | | a popup. Default |
| | | | value if not |
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| | | | returned should be |
| | | | 750px. |
+--------------+---------------------+--------+---------------------+
| *Height of | height | Number | (OPTIONAL) This is |
| Window* | | | the desired height |
| | | | of the window for |
| | | | granting consent |
| | | | when navigated in |
| | | | a popup. Default |
| | | | value if not |
| | | | returned should be |
| | | | 750px. |
+--------------+---------------------+--------+---------------------+
| *UX URL | urlControlPanel | String | (OPTIONAL) This is |
| Control | | | a URL to the |
| Panel* | | | control panel for |
| | | | editing DNS at the |
| | | | DNS Provider. |
| | | | This field allows |
| | | | a Service Provider |
| | | | whose template |
| | | | isn't supported at |
| | | | the DNS Provider |
| | | | to provide a |
| | | | direct link to |
| | | | perform manual |
| | | | edits. To allow |
| | | | deep links to the |
| | | | specific domain, |
| | | | this string may |
| | | | contain %domain% |
| | | | which must be |
| | | | replaced with the |
| | | | domain name. |
+--------------+---------------------+--------+---------------------+
| *Name | nameServers | String | (OPTIONAL) This is |
| Servers* | | List | the list of |
| | | | nameservers |
| | | | desired by the DNS |
| | | | Provider for the |
| | | | zone to be |
| | | | authoritative. |
| | | | This does not |
| | | | indicate the |
| | | | authoritative |
| | | | nameservers; for |
| | | | this the registry |
| | | | would be queried. |
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+--------------+---------------------+--------+---------------------+
Table 1: properties of the settings data structure
{
"providerId": "virtucondomains.example",
"providerName": "Virtucon Domains",
"providerDisplayName": "Virtucon Domains",
"urlSyncUX": "https://domainconnect.virtucondomains.example",
"urlAsyncUX": "https://domainconnect.virtucondomains.example",
"urlAPI": "https://api.domainconnect.virtucondomains.example",
"width": 750,
"height": 750,
"urlControlPanel": "https://domaincontrolpanel.virtucondomains.ex
ample/?domain=%domain%",
"nameServers": ["ns01.virtucondomainsdns.example", "ns02.virtucon
domainsdns.example"]
}
Discovery must work on the root domain (zone) only. Bear in mind
that zones can be delegated to other users, making this information
valuable to Service Providers since DNS changes may be different for
an apex zone vs. a sub-domain for an individual service.
The Service Provider must handle the condition when a query for the
_domainconnect TXT record suceeds, but a call to query for the JSON
fails. This can happen if the zone is hosted with another DNS
Provider, but contains an incorrect _domainconnect TXT record.
The DNS Provider must return a 404 if they do not contain the zone.
+===========+==========+===========================================+
| Status | Response | Description |
+===========+==========+===========================================+
| *Success* | 2xx | A response of an http status code of 2xx |
| | | indicates that the call was successful. |
| | | The response is the JSON described above. |
+-----------+----------+-------------------------------------------+
| *Not | 404 | A response of a 404 indicates that the |
| Found* | | DNS Provider does not have the zone. |
+-----------+----------+-------------------------------------------+
Table 2: HTTP status codes for the settings end-point
7. Applying Domain Connect
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7.1. Endpoints
The Domain Connect endpoints returned in the JSON during discovery
are in the form of URLs.
The first set of endpoints are for the UX that the Service Provider
links to. These are for the synchronous flow where the user can
click to grant consent and have changes applied, and for the
asynchronous OAuth flow where the user can grant consent for OAuth
access.
The second set of endpoints are for the REST API.
All endpoints begin with a root URL for the DNS Provider such as:
https://connect.dnsprovider.example
They may also include any prefix at the discretion of the DNS
Provider. For example:
https://connect.dnsprovider.example/api
The root URLs for the UX endpoints and the API endpoints are returned
in the JSON payload during DNS Provider discovery.
7.2. Synchronous Flow
7.2.1. Query Supported Template
GET
{urlAPI}/v2/domainTemplates/providers/{providerId}/services
/{serviceId}
This URL is be used by the Service Provider to determine if the DNS
Provider supports a specific template through the synchronous flow.
Returning a status of 200 without a body indicates the template is
supported. The DNS provider may decide to disclose the version of
the template in a JSON object with field _version_ (see: version
field (Section 8.2) or the full JSON object of deployed template.
Returning a status of 404 indicates the template is not supported.
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+===========+==========+======================================+
| Status | Response | Description |
+===========+==========+======================================+
| *Success* | 2xx | A response of an http status code of |
| | | 2xx indicates that the call was |
| | | successful. The response OPTIONALLY |
| | | contains the version or template. |
+-----------+----------+--------------------------------------+
| *Not | 404 | A response of a 404 indicates that |
| Found* | | the template is not supported |
+-----------+----------+--------------------------------------+
Table 3: https status codes for the Query Supported
Template end-point
7.2.2. Apply Template
7.2.2.1. Apply Template URL
GET
{urlSyncUX}/v2/domainTemplates/providers/{providerId}/services
/{serviceId}/apply?[properties]
This is the URL where the user is sent to apply a template to a
domain they own. It is called from the Service Provider to start the
synchronous Domain Connect Protocol.
This URL can be called in one of two ways.
7.2.2.2. New Browser Window
The first is through a new browser tab or in a popup browser window.
The DNS Provider signs the user in if necessary, verifies domain
ownership, and asks for confirmation before application of the
template. After application of the template, the DNS Provider should
automatically close the browser tab or window.
7.2.2.3. Same Browser Window
The second is in the current browser tab/window. As above the DNS
Provider signs the user in if necessary, verifies the user control of
the DNS Zone for the domain, and asks for confirmation before
application of the template. After application of the template (or
cancellation by the user), the DNS Provider must redirect the browser
to a return URL (redirect_uri).
Several parameters must be appended to the end of this redirect_uri.
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* State
If a state parameter is passed in on the query string, this must
be passed back as state= on the redirect_uri.
* Error
If authorization could not be obtained or an error has occurred,
the parameter error= must be appended. For consistency with the
asynchronous OAuth flows the valid values for the error parameter
will be as specified in OAuth 2.0 [RFC6749] (4.1.2.1. Error
Response - "error" parameter). Valid values are: invalid_request,
unauthorized_client, access_denied, unsupported_response_type,
invalid_scope, server_error, and temporarily_unavailable.
* Error Description
When an error occurs, an OPTIONAL error description containing a
developer focused error description may be returned.
Under normal operation the access_denied error can be returned for
a number of reasons. For example, the user may not have access to
the account that owns the domain. Even if they do and
successfully sign-in, the account or the domain may be suspended.
It is unlikely that the DNS Provider would want to leak this
information to the Service Provider, and as such the description
may be vague.
There is one piece of information that may be interesting to
communicate to the Service Provider. This is when the end user
decided to cancel the operation. If the DNS Provider wishes to
communicate this to the Service Provider, when the
error=access_denied the error_description may contain the prefix
"user_cancel". Again, this is left to the discretion of the DNS
Provider.
To prevent an open redirect, unless the request is digitally signed
the redirect_uri must be within the domains specified in the template
in syncRedirectDomain.
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7.2.2.4. Parameters/properties
+=============+==============+======================================+
| Property | Request | Description |
| | Parameter | |
+=============+==============+======================================+
| *Domain* | domain | (REQUIRED) The domain name being |
| | | configured. This is the root |
| | | domain (the registered domain or |
| | | delegated zone). |
+-------------+--------------+--------------------------------------+
| *Host* | host | (OPTIONAL) This is the host name of |
| | | the sub domain. If left blank, the |
| | | template is being applied to the |
| | | root domain. Otherwise the |
| | | template is applied to the sub |
| | | domain of the domain. |
+-------------+--------------+--------------------------------------+
| *Redirect | redirect_uri | (OPTIONAL) The location to direct |
| URI* | | the client browser to upon |
| | | successful authorization, or upon |
| | | error. If omitted the DNS Provider |
| | | will close the browser window upon |
| | | completion. It must be scoped to |
| | | the syncRedirectDomain from the |
| | | template, or the request must be |
| | | signed. |
+-------------+--------------+--------------------------------------+
| *State* | state | (OPTIONAL) A random and unique |
| | | string passed along to prevent |
| | | CSRF, or to pass back state. It |
| | | must be returned as a parameter |
| | | when redirecting to the |
| | | redirect_uri described above. |
+-------------+--------------+--------------------------------------+
| *Name/Value | * | (REQUIRED) Any key that will be |
| Pairs* | | used as a replacement for the "% |
| | | surrounded" variables in the |
| | | template. The name portion of this |
| | | API call corresponds to the |
| | | variable(s) specified in the |
| | | template and the value corresponds |
| | | to the value that will be used when |
| | | applying the template. |
+-------------+--------------+--------------------------------------+
| *Provider | providerName | (OPTIONAL) This parameter allows |
| Name* | | for the caller to provide |
| | | additional text for display with |
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| | | the template providerName. This |
| | | text should be used to augment the |
| | | providerName value from the |
| | | template, not replace it. This |
| | | parameter is only allowed when the |
| | | "sharedProviderName" attribute is |
| | | set in the template. Note: this |
| | | used to be controlled by the |
| | | "shared" attribute in the template, |
| | | which has been deprecated. |
+-------------+--------------+--------------------------------------+
| *Service | serviceName | (OPTIONAL) This parameter allows |
| Name* | | for the caller to provide |
| | | additional text for display with |
| | | the template serviceName. It |
| | | should be used to augment the |
| | | serviceName value from the |
| | | template, not replace it. This |
| | | parameter is only allowed when the |
| | | "sharedServiceName" attribute is |
| | | set in the template. |
+-------------+--------------+--------------------------------------+
| *Group Id* | groupId | (OPTIONAL) This parameter specifies |
| | | the groups from the template to |
| | | apply. If no group is specified, |
| | | all groups are applied. Multiple |
| | | groups may be specified in a comma |
| | | delimited format. |
+-------------+--------------+--------------------------------------+
| *Signature* | sig | (OPTIONAL) A signature of the query |
| | | string. See Security |
| | | Considerations section below. |
+-------------+--------------+--------------------------------------+
| *Key* | key | (OPTIONAL) A value containing the |
| | | host in DNS where the public key |
| | | for the signature can be obtained. |
| | | The domain for this host is in the |
| | | template in syncPubKeyDomain. See |
| | | Security Considerations section |
| | | below. |
+-------------+--------------+--------------------------------------+
Table 4: query parameters of the apply call in the sync flow
An example query string:
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GET
https://web-connect.dnsprovider.example/v2/domainTemplates/providers/
exampleservice.example/services/template1/apply?domain=example.com
&IP=192.168.42.42&RANDOMTEXT=shm%3A1542108821%3AHello
This call indicates that the Service Provider wishes to connect the
domain example.com to the service using the template identified by
the composite key of the provider (exampleservice.example) and the
service template owned by them (template1). In this example, there
are two variables in this template, "IP" and "RANDOMTEXT". These
variables are passed as name/value pairs.
7.2.3. Security Considerations
7.2.3.1. Risk of phishing with open template parameters
By applying a template with parameters there is a security
consideration that must be taken into account.
Consider the template above where the IP address of the A record is
passed in through a variable. A bad actor could generate a URL with
a malicious IP and phish users by sending out emails asking them to
"re-configure" their service. If an end user is convinced to click
on this link, they would land on the DNS Provider site to confirm the
change. To the user, this would appear to be a valid request to
configure the domain. Yet the IP would be hijacking the service.
Not all templates have this problem. But when they do, there are
several options.
7.2.3.2. Disable Synchronous
One option is to disable the synchronous flow and use asynchronous
OAuth. This can be controlled with the syncBlock value from the
template. However, as will be seen below OAuth has a higher
implementation burden and requires onboarding between each Service
and DNS Provider.
7.2.3.3. Digitally Sign Requests
Another option is to digitally sign the query string. A signature is
appended as an additional query string parameter, properly URL
encoded and of the form:
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sig=V2te9zWMU7G3plxBTsmYSJTvn2vzMvNwAjWQ%2BwTe91DxuJhdVf4cVc4vZBYfEYV
7u5d7PzTO7se7OrkhyiB7TpoJJW1yB5qHR7HKM5SZldUsdtg5%2B1SzEtIX0Uq8b2mCmQ
F%2FuJGXpqCyFrEajvpTM7fFKPk1kuctmtkjV7%2BATcvNPLWY7KyE4%2Bqc8jpfN61cP
5l8iA4krAa3%2BfTro5cmWR8YUJ5yrnRs6KT4b5D71HFvOUk0sGEUddUUlsyRQKRHUFN6
HjEya50YDHfZJlYHkHlK0xX6Yqeii9QZ2I35U9eJbSvZGQko5beqviWFXdsVDbvd3DYcb
SHgJq9%2FXoMTTw%3D%3D
The Service Provider generates this signature using a private key.
As indicated, this signature is generated from the query string
properly URL encoded.
The Service provider must publish their public key and place it in a
DNS TXT record in a domain specified in the template in
*syncPubKeyDomain*. To allow for key rotation, the host name of the
TXT record must be appended as another variable on the query string
of the form:
key=_dcpubkeyv1
This example indicates that the public key can be found by doing a
DNS query for a TXT record called _dcpubkeyv1 in the domain specified
in the syncPubKeyDomain from the template.
To account for DNS Servers with limits to the size of a TXT record,
multiple records may exist for the DNS TXT query. For example, a
public key of:
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA18SgvpmeasN4BHkkv0SBjAzIc
4grYLjiAXRtNiBUiGUDMeTzQrKTsWvy9NuxU1dIHCZy9o1CrKNg5EzLIZLNyMfI6qiXnM
+HMd4byp97zs/3D39Q8iR5poubQcRaGozWx8yQpG0OcVdmEVcTfyR/XSEWC5u16EBNvRn
NAOAvZYUdWqVyQvXsjnxQot8KcK0QP8iHpoL/1dbdRy2opRPQ2FdZpovUgknybq/6FkeD
tW7uCQ6Mvu4QxcUa3+WP9nYHKtgWip/eFxpeb+qLvcLHf1h0JXtxLVdyy6OLk3f2JRYUX
2ZZVDvG3biTpeJz6iRzjGg6MfGxXZHjI8weDjXrJwIDAQAB
may contain several TXT records. The records would be of the form:
p=1,a=RS256,d=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA18SgvpmeasN
4BHkkv0SBjAzIc4grYLjiAXRtNiBUiGUDMeTzQrKTsWvy9NuxU1dIHCZy9o1CrKNg5EzL
IZLNyMfI6qiXnM+HMd4byp97zs/3D39Q8iR5poubQcRaGozWx8yQpG0OcVdmEVcTfy
p=2,a=RS256,d=R/XSEWC5u16EBNvRnNAOAvZYUdWqVyQvXsjnxQot8KcK0QP8iHpoL/1
dbdRy2opRPQ2FdZpovUgknybq/6FkeDtW7uCQ6Mvu4QxcUa3+WP9nYHKtgWip/eFxpeb+
qLvcLHf1h0JXtxLVdyy6OLk3f2JRYUX2ZZVDvG3biTpeJz6iRzjGg6MfGxXZHjI8
p=3,a=RS256,d=weDjXrJwIDAQAB
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Here the public key is broken into four records in DNS, and the data
also indicates that the signing algorithm is an RSA Signature with
SHA-256 using an x509 certificate. The value for "a" if omitted will
be assumed to be RS256, and for "t" will be assumed to be x509.
Note: The only algorithm currently supported is SHA-256 with x509
certificates. The values are placed here for future compatibility.
The above data was generated for a query string:
a=1&b=2&ip=10.10.10.10&domain=example.net
Signing the query string by the Service Provider is OPTIONAL. Not
all Services Provider templates require or are able to provide this
level of security. Presence of the *syncPubKeyDomain* in the
template indicates that the template requires signature verification.
Notes:
The digital signature will be generated on the full query string
only, excluding the sig and key parameters. This is everything after
the ?, except the sig and key values.
The values of each query string value key/value pair must be properly
URL Encoded before the signature is generated.
7.2.3.4. Warnings
Some applications aren't able to use OAuth and/or sign requests.
If the template require variables, and OAuth and signing isn't
available, the flag *warnPhishing* must be set to true in the
template.
When set this indicates to the DNS Provider that they should display
extra warnings to the user to have them verify the link was/is from a
reputable source before applying the template.
7.2.4. Shared Templates
Some templates can be called by multiple companies, or be used for
different purposes.
For example, most services are sold and provided by the same company.
However, some Service Providers have a reseller channel. This allows
the service to be provided by the Service Provider, but sold through
third parties. It is often this third party reseller that configures
DNS.
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While each reseller could enable Domain Connect, this is inefficient
for the DNS Providers. Enabling a single template that is shared by
multiple resellers would be more optimal.
As another example, some templates may be used for different purposes
by the same company.
To facilitate these use cases, the ability to pass in additional
context for the display of the providerName and serviceName is
enabled. This is only allowed when the template enables the
capability through the sharedProviderName and/or sharedServiceName
flags.
Note: The shared flag used to be used for this purpose, but has been
deprecated.
The exact message presented to the user is up to the DNS Provider.
However it is recommended that these fields be used to augment the
display of the serviceName and providerName from the template, not
replace it.
Note: When a Service Provider has a large reseller channel, it is
highly recommended that the Service Provider creates an API for their
resellers to ease the implementation of Domain Connect. There are
elements of convenience in doing this around Domain Discovery and URL
Formatting. But this would be required if the template required
signatures.
7.2.5. Verification of Changes
There are circumstances where the Service Provider may wish to verify
that the template was successfully applied. Without Domain Donnect,
this typically involved the Service Provider querying DNS to see if
the changes to DNS had been made.
This same technique works with Domain Connect, and if necessary can
be triggered either manually on the Service Provider site or
automatically upon page/window activation in the browser when the
browser window for the DNS Provider is closed.
When the redirect_uri is used and an error is not present in the URI,
the Service Provider can not assume the changes were applied to DNS.
While true in most circumstances, users can tamper with or alter the
return url in the browser. As such it is recommend that enablement
of a service be based on verification of changes to DNS.
7.3. Asynchronous Flow: OAuth
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7.3.1. General information
Using the OAuth flow is a more advanced use case needed by Service
Providers that have more complex configurations that may require
multiple steps and/or are asynchronous from the user's interaction.
Details of an OAuth implementation are beyond the scope of this
specification. Instead, an overview of how OAuth is used by Domain
Connect is given here.
Not all DNS Providers will support the asyncronous flow. As such it
is recommended that Service Providers relying on an OAuth
implementation also implement a synchronous implementation.
7.3.2. OAuth Flow: Setup
Service providers wishing to use the OAuth flow must register as an
OAuth client with each DNS provider. This is a manual process.
To register, the Service Provider would provide (in addition to their
template) any configuration necessary for the DNS Providers OAuth
implementation. This includes valid URLs and Domains for redirects
upon success or errors.
Note: The validity of redirects are very important in any OAuth
implementation. Most OAuth vulnerabilities are a combination of an
open redirect and/or a compromised secret.
In return, the DNS provider will give the Service Provider a client
id and a secret which will be used when requesting tokens. For
simplicity the client id should be the same as the providerId.
7.3.3. OAuth Flow: Getting an Authorization Code
GET
{urlAsyncUX}/v2/domainTemplates/providers/{providerId}
To initiate the OAuth flow the Service Provider first links to the
DNS Provider to gain consent.
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This endpoint is similar to the synchronous flow described above.
The DNS Provider must authenticate the user, verify the user has
control of the DNS Zone for the domain, and ask the user for
permission. Instead of permission to make a change to DNS, the
permission is now to allow the Service Provider to make the changes
on their behalf. Similarly the DNS Provider may warn the user that
(the eventual) application of a template might change existing
records and/or disrupt existing services attached to the domain.
While the variables for the applied template would be provided later,
the values of some variables may be necessary to determine conflicts.
As such, any variables impacting conflicting records should be
provided in the consent flow. Today this includes variables in
hosts, and variables in the data portion for certain TXT records. As
conflict resolution evolves, this list may grow.
The protocol allows for the Service Provider to gain consent to apply
multiple templates. These templates are specified in the *scope*
parameter. It also allows for the Service Provider to gain consent
to apply these templates to the domain or to the domain with multiple
sub-domains. These are specified in the *domain* and *host*
parameter. If conflict detection is implemented by the DNS Provider,
they should account for all permutations.
The scope parameter is a space separated list (as per the OAuth
protocol) of the template serviceIds. The host parameter is an
OPTIONAL comma separated list of hosts. A blank entry for the host
implies the template can be applied to the root domain. For example:
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+===================================+=====================+
| *Query String* | *Description* |
+===================================+=====================+
| scope=t1+t2=example.com | Templates "t1" and |
| | "t2" can be applied |
| | to example.com |
+-----------------------------------+---------------------+
| scope=t1+t2=example.com=sub1,sub2 | Templates "t1" and |
| | "t2" can be applied |
| | to sub1.example.com |
| | or sub2.example.com |
+-----------------------------------+---------------------+
| scope=t1+t2=example.com=sub1, | Templates "t1" and |
| | "t2" can be applied |
| | to example.com or |
| | sub1.example.com |
+-----------------------------------+---------------------+
Table 5: examples of scope and host parameter values in
the async flow
Upon successful authorization/verification/consent from the user, the
DNS Provider will direct the end user's browser to the redirect URI.
The authorization code will be appended to this URI as a query
parameter of "code=" as per the OAuth specification.
Similar to the synchronous flow, upon error the DNS provider may
append an error code as query parameter "error". These errors are
also from the OAuth 2.0 [RFC6749] (4.1.2.1. Error Response - "error"
parameter). Valid values include: invalid_request,
unauthorized_client, access_denied, unsupported_response_type,
invalid_scope, server_error, and temporarilly_unavailable. An
OPTIONAL error_description suitable for developers may also be
returned at the discretion of the DNS Provider. The same
considerations as in the synchronous flow apply here.
The state value passed into the call must be passed back on the query
string as "state=".
The following table describes the values in the query string
parameters for the request for the OAuth consent flow that must be
included unless otherwise indicated
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+===========+===============+==================================+
| Property | Key | Description |
+===========+===============+==================================+
| *Domain* | domain | (REQUIRED) The domain name being |
| | | configured. This is the root |
| | | domain (the registered domain or |
| | | delegated zone). |
+-----------+---------------+----------------------------------+
| *Host* | host | (OPTIONAL) An list of comma |
| | | separated host names upon which |
| | | the template may be applied. An |
| | | empty string implies the root. |
+-----------+---------------+----------------------------------+
| *Client | client_id | (REQUIRED) The client id that |
| Id* | | was provided by the DNS provider |
| | | to the service provider during |
| | | registration. It is recommended |
| | | that this should be the same as |
| | | the providerId in the template. |
+-----------+---------------+----------------------------------+
| *Redirect | redirect_uri | (REQUIRED) The location to |
| URI* | | direct the client's browser upon |
| | | successful authorization or upon |
| | | error. Validation of the |
| | | redirect_uri will be done by the |
| | | DNS Provider to match the values |
| | | provided during onboarding. |
+-----------+---------------+----------------------------------+
| *Response | response_type | (OPTIONAL) If included it must |
| type* | | be the string 'code' to indicate |
| | | an authorization code is being |
| | | requested. |
+-----------+---------------+----------------------------------+
| *Scope* | scope | (REQUIRED) The OAuth scope |
| | | corresponds to the requested |
| | | templates. This is list of |
| | | space separated serviceIds. |
+-----------+---------------+----------------------------------+
| *Provider | providerName | (OPTIONAL) This parameter allows |
| Name* | | for the caller to provide |
| | | additional text for display with |
| | | the template providerName. This |
| | | text should be used to augment |
| | | the providerName value from the |
| | | template, not replace it. |
+-----------+---------------+----------------------------------+
| *Service | serviceName | (OPTIONAL) This parameter allows |
| Name* | | for the caller to provide |
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| | | additional text for display with |
| | | the template serviceName(s). It |
| | | should be used to augment the |
| | | serviceName value(s) from the |
| | | template, not replace. |
+-----------+---------------+----------------------------------+
| *State* | state | (OPTIONAL) This is a random, |
| | | unique string passed along to |
| | | prevent CSRF or to pass state |
| | | value back to the caller. It |
| | | will be returned as a parameter |
| | | appended to the redirect_url |
| | | described above. |
+-----------+---------------+----------------------------------+
| *Name/ | * | (OPTIONAL) Any key that will be |
| Value | | used as a replacement for the "% |
| Pairs* | | surrounded" value(s) in a |
| | | template required for conflict |
| | | detection. This includes |
| | | variables used in hosts and data |
| | | in certain TXT records. |
+-----------+---------------+----------------------------------+
Table 6: query parameters of the authorization end-point in
async flow
7.3.4. OAuth Flow: Requesting an Access Token
POST
{urlAPI}/v2/oauth/access_token
Once authorization has been granted, the Service Provider must use
the Authorization Code provided to request an Access Token. The
OAuth specification recommends that the Authorization Code be a short
lived token, and a reasonable recommended setting is ten minutes. As
such this exchange needs to be completed before that time has expired
or the process will need to be repeated.
This token exchange is typically done via a server to server API call
from the Service Provider to the DNS Provider using a POST. When
called in this manner a secret is provided along with the
Authorization Code.
OAuth does allow for retrieving the access token without a secret.
This is typically done when the OAuth client is a client application.
When onboarding with the DNS Provider this would need to be enabled.
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When the secret is provided (which is the normal case), care must be
taken. A malicious user could create a domain that returns a false
__domainconnect_ TXT record, and subsequently a JSON call to their
own server for the API end point. By doing so, they could then run
Domain Connect on their domain and retrieve the secret.
As such the urlAPI used for OAuth by the Service Provider should be
maintained per DNS Provider and not the value retrieved during
discovery.
The following table describes the POST parameters that must be
included in the request for the access token unless otherwise
indicated. The parameters should be accepted via the query string or
the body of the post. This is again particularly important for the
client_secret, as passing secrets via a query string is generally
frowned upon given that various systems often log URLs.
The body of the post is application/json encoded.
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+================+===============+=================================+
| Property | Key | Description |
+================+===============+=================================+
| *Authorization | code/ | (REQUIRED) The authorization |
| Code/Refresh | refresh_token | code that was provided in the |
| Code* | | previous step when the customer |
| | | accepted the authorization |
| | | request, or the refresh_token |
| | | for a subsequent access token. |
+----------------+---------------+---------------------------------+
| *Redirect URI* | redirect_uri | (OPTIONAL) This is REQUIRED if |
| | | a redirect_uri was passed to |
| | | request the authorization code. |
| | | When included, it needs to be |
| | | the same redirect_uri provided |
| | | in this step. |
+----------------+---------------+---------------------------------+
| *Grant type* | grant_type | (REQUIRED) The type of code in |
| | | the request. Usually the |
| | | string 'authorization_code' or |
| | | 'refresh_token' |
+----------------+---------------+---------------------------------+
| *Client ID* | client_id | (REQUIRED) This is the client |
| | | id that was provided by the DNS |
| | | provider to the Service |
| | | Provider during registration |
+----------------+---------------+---------------------------------+
| *Client | client_secret | (REQUIRED) The secret provided |
| Secret* | | to the Service Provider during |
| | | registration. Typically |
| | | required unless the rare |
| | | circumstance with secret-less |
| | | OAuth. |
+----------------+---------------+---------------------------------+
Table 7: parameters of the token end-point
Upon successful token exchange, the DNS Provider will return a
response with 4 properties in the body of the response.
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+=================+===========================================+
| Property | Description |
+=================+===========================================+
| *access_token* | The access token to be used when making |
| | API requests |
+-----------------+-------------------------------------------+
| *token_type* | Always the string "bearer" |
+-----------------+-------------------------------------------+
| *expires_in* | The number of seconds until the |
| | access_token expires |
+-----------------+-------------------------------------------+
| *refresh_token* | The token that can be used to request new |
| | access tokens when this one has expired. |
+-----------------+-------------------------------------------+
Table 8: properties of the token end-point response
+===========+==========+===========================================+
| Status | Response | Description |
+===========+==========+===========================================+
| *Success* | 2xx | A response of an http status code of 2xx |
| | | indicates that the call was successful. |
| | | The response is the JSON described above. |
+-----------+----------+-------------------------------------------+
| *Errors* | 4** | All other responses indicate an error. |
+-----------+----------+-------------------------------------------+
Table 9: http status codes of the token end-point response
7.3.5. OAuth Flow: Making Requests with Access Tokens
Once the Service Provider has the access token, they can call the DNS
Provider's API to make changes to DNS on the domain by applying and
(OPTIONALLY) removing authorized templates. These templates can be
applied to the root domain or to any sub-domain of the root domain
that has been authorized.
All calls to this API pass the access token in the Authorization
Header of the request to the call to the API. More details can be
found in the OAuth specifications, but as an example:
GET /resource/1 HTTP/1.1
Host: example.com
Authorization: Bearer mF_9.B5f-4.1JqM
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While the calls below do not have the same security consideration of
passing the secret, it is recommend that the urlAPI be from a stored
value vs. the value returned during discovery here as well.
7.3.6. OAuth Flow: Apply Template to Domain.
POST
{urlAPI}/v2/domainTemplates/providers/{providerId}/services
/{serviceId}/apply?[properties]
The primary function of the API is to apply a template to a customer
domain.
While the providerId is implied in the authorization, this is on the
path for consistency with the synchronous flows and other APIs. If
not matching what was authorized, an error must be returned.
When applying a template to a domain, it is possible that a conflict
may exist with previous settings. While it is recommended that
conflicts be detected when the user grants consent, because OAuth is
asynchronous it is possible that a new conflict was introduced by the
user.
While it is up to the DNS Provider to determine what constitutes a
conflict (see section on Conflicts below), when one is detected
calling this API must return an error. This error should enumerate
the conflicting records in a format described below.
Because the user often isn't present at the time of this error, it is
up the Service Provider to determine how to handle this condition.
Some providers may decide to notify the user. Others may decide to
apply their template anyway using the "force" parameter. This
parameter will bypass error checks for conflicts, and after the call
the service will be in its desired state.
Calls to apply a template via OAuth require the following parameters
posted to the above URL unless otherwise indicated. The DNS Provider
must accept parameters in query string or body of this post.
The body is application/json encoded.
+==============+==============+===================================+
| Property | Key | Description |
+==============+==============+===================================+
| *Domain* | domain | (REQUIRED) The root domain name |
| | | being configured. It must match |
| | | the domain that was authorized in |
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| | | the token. |
+--------------+--------------+-----------------------------------+
| *Host* | host | (OPTIONAL) The host name of the |
| | | sub domain of the root domain |
| | | that was authorized in the token. |
| | | If omitted or left blank, the |
| | | template is being applied to the |
| | | root domain. |
+--------------+--------------+-----------------------------------+
| *Name/Value | * | (REQUIRED) Any variable fields |
| Pairs* | | consumed by this template. The |
| | | name portion of this API call |
| | | corresponds to the variable(s) |
| | | specified in the record and the |
| | | value corresponds to the value |
| | | that must be used when applying |
| | | the template as per the |
| | | implementation notes. |
+--------------+--------------+-----------------------------------+
| *Group ID* | groupId | (OPTIONAL) Specifies the group of |
| | | changes in the template to apply. |
| | | If omitted, all changes are |
| | | applied. This can also be a |
| | | comma separated list of groupIds. |
+--------------+--------------+-----------------------------------+
| *Force* | force | (OPTIONAL) Specifies that the |
| | | template must be applied |
| | | independently of any conflicts |
| | | that may exist on the domain. |
| | | This can be a value of 0 or 1. |
+--------------+--------------+-----------------------------------+
| *Provider | providerName | (OPTIONAL) This parameter allows |
| Name* | | for the caller to provide |
| | | additional context for the |
| | | providerName that applied the |
| | | template. It may be used by some |
| | | DNS Providers that display state |
| | | regarding which templates have |
| | | been applied. It is only allowed |
| | | when the "sharedProviderName" |
| | | attribute is set in the template |
| | | being applied. |
+--------------+--------------+-----------------------------------+
| *Service | serviceName | (OPTIONAL) This parameter allows |
| Name* | | for the caller to provide |
| | | additional context for the |
| | | serviceName that applied the |
| | | template. It may be used by some |
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| | | DNS Providers that display state |
| | | regarding which templates have |
| | | been applied. It is only allowed |
| | | when the "sharedProviderName" |
| | | attribute is set in the template |
| | | being applied. |
+--------------+--------------+-----------------------------------+
| *InstanceId* | instanceId | (OPTIONAL) Only applicable to |
| | | templates supporting multiple |
| | | instances (see multiInstance |
| | | (Section 8.2) template property). |
| | | Allows for later removal of one |
| | | template instance by DNS |
| | | Providers storing this |
| | | information. |
+--------------+--------------+-----------------------------------+
Table 10: query parameters of the apply end-point in the async flow
An example call is below. In this example, it is contemplated that
there are two variables in this template, "IP" and "RANDOMTEXT" which
both require values. These variables are passed as name/value pairs.
POST
https://connect.dnsprovider.example/v2/domainTemplates/providers/
exampleservice.example/services/template1/apply?IP=192.0.2.42
&RANDOMTEXT=shm%3A1542108821%3AHello&force=1
The API must validate the access token, and that the domain belongs
to the customer and is represented by the token being presented. Any
errors with variables, conflicting templates, or problems with the
state of the domain are returned; otherwise the template is applied.
Results of this call can include information indicating success or an
error. Errors will be 400 status codes, with the following codes
defined.
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+================+==========+==================================+
| Status | Response | Description |
+================+==========+==================================+
| *Success* | 2xx | A response of an http status |
| | | code of 204 indicates that call |
| | | was successful and the template |
| | | applied. Note that any 200 |
| | | level code must be considered a |
| | | success. |
+----------------+----------+----------------------------------+
| *Bad Request* | 400 | A response of a 400 indicates |
| | | that the server cannot process |
| | | the request because it was |
| | | malformed or had errors. This |
| | | response code is intended for |
| | | programming errors. |
+----------------+----------+----------------------------------+
| *Unauthorized* | 401 | A response of a 401 indicates |
| | | that caller is not authorized to |
| | | make this call. This can be |
| | | because the token was revoked, |
| | | or other access issues. |
+----------------+----------+----------------------------------+
| *Conflict* | 409 | This indicates that the call was |
| | | good, and the caller authorized, |
| | | but the change could not be |
| | | applied due to a conflicting |
| | | template. Errors due to |
| | | conflicts will only be returned |
| | | when force is not equal to 1. |
+----------------+----------+----------------------------------+
| *Error* | 4xx | Other 4xx error codes may be |
| | | returned when something is wrong |
| | | with the request that makes |
| | | applying the template |
| | | problematic; most often |
| | | something that is wrong with the |
| | | account and requires attention. |
+----------------+----------+----------------------------------+
Table 11: http status codes of the apply end-point in the
async flow
When a 409 is returned, the body of the response should contain
details of the conflicting records. This should be JSON containing
the error code, a message suitable for developers, and an array of
tuples containing the conflicting records type, host, and data
element.
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As an example:
{
"code": "409",
"message": "Conflicting records",
"records": [
{
"type": "CNAME",
"host": "www",
"data": "@"
},
{
"type": "A",
"host": "@",
"data": "random ip"
}
]
}
In this example, the Service Provider tried to apply a new hosting
template. The domain had an existing service applied for hosting.
7.3.7. OAuth Flow: Revert Template
This call reverts the application of a specific template from a
domain.
Implementation of this call is OPTIONAL. If not supported a 501 MUST
be returned.
POST
{urlAPI}/v2/domainTemplates/providers/{providerId}/services
/{serviceId}/revert?domain={domain}&host={host}
This API allows the removal of a template from a customer domain/host
using an OAuth request.
The provider and service name in the URL must match the values
provided during authorization.
This call must validate that the template exists and has been applied
to the domain by the Service Provider, or a warning must be returned
that the call would have no effect.
An example query string might look like:
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POST
https://connect.dnsprovider.example/v2/domainTemplates/providers
/exampleservice.example/services/template1/revert?domain=example.com
Allowed parameters:
+==============+============+======================================+
| Property | Key | Description |
+==============+============+======================================+
| *Domain* | domain | (REQUIRED) The root domain name |
| | | being configured. It must match the |
| | | domain that was authorized in the |
| | | token. |
+--------------+------------+--------------------------------------+
| *Host* | host | (OPTIONAL) The host name of the sub |
| | | domain of the root domain that was |
| | | authorized in the token. If omitted |
| | | or left blank, the template is being |
| | | applied to the root domain. |
+--------------+------------+--------------------------------------+
| *InstanceId* | instanceId | (OPTIONAL) Only applicable to |
| | | templates supporting multiple |
| | | instances (see multiInstance |
| | | (Section 8.2) template property). |
| | | For DNS Provider storing information |
| | | about applied templates allows |
| | | removal of single instance of |
| | | template. If missing all instances |
| | | of template should be removed. |
+--------------+------------+--------------------------------------+
Table 12: query parameters of the revert end-point in the async flow
The DNS Provider should be able to accept these on the query string
or in the body of the POST with application/json encoding.
Response codes Success, Authorization, and Errors are identical to
above with the addition of the 501 code.
7.3.8. OAuth Flow: Revoking access
Like all OAuth flows, the user may revoke the access at any time
using UX at the DNS Provider site. As such the Service Provider
needs to be aware that their access to the API may be denied.
8. Domain Connect Objects and Templates
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8.1. Template Versioning
If a breaking change is made to a template it is recommended that a
new template be created. While on the surface versioning looks
appealing, in reality this is rarely needed.
Any changes to the template need to account for existing customers
with settings in DNS, some applied through Domain Connect and some
manual. So when changes are made, they are often backward
compatible.
Note that when a template changes, it does need to be on-boarded with
the DNS Providers.
The version field (Section 8.2) of the template definition serves the
purpose of transparency between the DNS Provider and the Service
Provider in case of such changes.
8.2. Template Definition
A template is defined as a standard JSON data structure containing
the following data. Fields are required unless otherwise indicated.
+=============+========+===================+========================+
|Data Element |Type |Key |Description |
+=============+========+===================+========================+
|*Service |String |providerId |(REQUIRED) The unique |
|Provider Id* | | |identifier of the |
| | | |Service Provider that |
| | | |created this template. |
| | | |This is used in the URLs|
| | | |to identify the Service |
| | | |Provider. To ensure |
| | | |non-coordinated |
| | | |uniqueness, this should |
| | | |be the domain name of |
| | | |the Service Provider |
| | | |(e.g. |
| | | |exampleservice.example).|
+-------------+--------+-------------------+------------------------+
|*Service |String |providerName |(REQUIRED) The name of |
|Provider | | |the Service Provider |
|Name* | | |suitable for display. |
| | | |This may be displayed to|
| | | |the user on the DNS |
| | | |Provider consent UX. |
+-------------+--------+-------------------+------------------------+
|*Service Id* |String |serviceId |(REQUIRED) The name or |
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| | | |identifier of the |
| | | |template. This is used |
| | | |in URLs to identify the |
| | | |template. It is also |
| | | |used in the scope |
| | | |parameter for OAuth. It|
| | | |MUST NOT contain space |
| | | |characters, and must be |
| | | |URL friendly. |
+-------------+--------+-------------------+------------------------+
|*Service |String |serviceName |(REQUIRED) The name of |
|Name* | | |the service suitable for|
| | | |display to the user. |
| | | |This may be displayed to|
| | | |the user on the DNS |
| | | |Provider consent UX. |
+-------------+--------+-------------------+------------------------+
|*Version* |Integer |version |(OPTIONAL) If present |
| | | |this represents a |
| | | |version of the template |
| | | |and should be increased |
| | | |with each update of the |
| | | |template content. This |
| | | |value is mainly |
| | | |informational to improve|
| | | |communication and |
| | | |transparency between |
| | | |providers. |
+-------------+--------+-------------------+------------------------+
|*Logo* |String |logoUrl |(OPTIONAL) A graphical |
| | | |logo representing the |
| | | |Service Provider and/or |
| | | |Service for use in any |
| | | |web-based flow. If |
| | | |present this may be |
| | | |displayed to the user on|
| | | |the DNS Provider consent|
| | | |UX. |
+-------------+--------+-------------------+------------------------+
|*Description*|Text |description |(OPTIONAL) A textual |
| | | |description of what this|
| | | |template attempts to do.|
| | | |This is meant to assist |
| | | |developers and MUST NOT |
| | | |be displayed to the |
| | | |user. |
+-------------+--------+-------------------+------------------------+
|*Variable |Text |variableDescription|(OPTIONAL) A textual |
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|Description* | | |description of what the |
| | | |variables are. This is |
| | | |meant to assist |
| | | |developers and MUST NOT |
| | | |be displayed to the |
| | | |user. |
+-------------+--------+-------------------+------------------------+
|*Synchronous |Boolean |syncBlock |(OPTIONAL) Indicates |
|Block* | | |that the synchronous |
| | | |protocol must be |
| | | |disabled for this |
| | | |template. The default |
| | | |for this is false. |
+-------------+--------+-------------------+------------------------+
|*Shared* |Boolean |shared |(OPTIONAL) This flag has|
| | | |been deprecated. It |
| | | |used to indicate that |
| | | |the template allowed a |
| | | |dynamic providerName on |
| | | |the query string. It is|
| | | |replaced with the |
| | | |sharedProviderName flag |
| | | |in v2.2 of the spec. |
+-------------+--------+-------------------+------------------------+
|*Shared |Boolean |sharedProviderName |(OPTIONAL) This flag |
|Provider | | |indicates that the |
|Name* | | |template allows the |
| | | |caller to pass in |
| | | |additional information |
| | | |for the providerName. |
| | | |This information should |
| | | |augment the display of |
| | | |the providerName from |
| | | |the template. The |
| | | |default for this is |
| | | |false. For backward |
| | | |compatability with DNS |
| | | |Providers not at V2.2 of|
| | | |the spec it is |
| | | |recommended that the |
| | | |shared flag also be set.|
+-------------+--------+-------------------+------------------------+
|*Shared |Boolean |sharedServiceName |(OPTIONAL) This flag |
|Service Name*| | |indicates that the |
| | | |template allows the |
| | | |caller to pass in |
| | | |additional information |
| | | |for the serviceName. |
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| | | |This information should |
| | | |augment the display of |
| | | |the serviceName from the|
| | | |template. The default |
| | | |for this is false. |
+-------------+--------+-------------------+------------------------+
|*Synchronous |String |syncPubKeyDomain |(OPTIONAL) When present,|
|Public Key | | |indicates that calls to |
|Domain* | | |apply a template |
| | | |synchronously must be |
| | | |digitally signed. The |
| | | |value indicates the |
| | | |domain name for querying|
| | | |the TXT record from DNS |
| | | |that contains the public|
| | | |key used for signing. |
+-------------+--------+-------------------+------------------------+
|*Synchronous |String |syncRedirectDomain |(OPTIONAL) When present,|
|Redirect | | |this is a comma |
|Domains* | | |separated list of domain|
| | | |names for which |
| | | |redirects must be sent |
| | | |to after applying a |
| | | |template for the |
| | | |synchronous flow. |
+-------------+--------+-------------------+------------------------+
|*Multiple |Boolean |multiInstance |(OPTIONAL) Defaults to |
|Instance* | | |False. When set to |
| | | |True, it indicates that |
| | | |the template may be |
| | | |applied multiple times. |
| | | |This only impacts DNS |
| | | |Providers that maintain |
| | | |template state in DNS. |
+-------------+--------+-------------------+------------------------+
|*Warn |Boolean |warnPhishing |(OPTIONAL) When present,|
|Phishing* | | |this tells the DNS |
| | | |Provider that the |
| | | |template may contain |
| | | |variables susceptible to|
| | | |phishing attacks and the|
| | | |provider is unable to |
| | | |digitally sign the |
| | | |requests. When set the |
| | | |DNS Provider should |
| | | |display warnings to the |
| | | |user. The default value|
| | | |for this is false. |
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+-------------+--------+-------------------+------------------------+
|*Host |Boolean |hostRequired |(OPTIONAL) Defaults to |
|Required* | | |false. When present |
| | | |this indicates that the |
| | | |template has been |
| | | |authored to work only |
| | | |when both domain and |
| | | |host are provided. An |
| | | |example where this would|
| | | |be true would be a |
| | | |template where CNAME is |
| | | |set on the fully |
| | | |qualified domain name. |
| | | |This is largely |
| | | |informational, as most |
| | | |DNS Providers already |
| | | |enforce such rules. |
+-------------+--------+-------------------+------------------------+
|*Template |Array of|records |(REQUIRED) A list of |
|Records* |Template| |records for the |
| |Records | |template. |
+-------------+--------+-------------------+------------------------+
Table 13: properties of the template definition
8.3. Template Record
Each template record is an entry that contains a type and several
other values depending on the type.
Many of these values can contain variables. There are three built in
variables.
* %host%: This is the host passed from the query string
* %domain%: This is the domain passed from the query string
* %fqdn%: This is the fully qualified domain name e.g. [host.]domain
The @ symbol has special meaning, and can be used in the host/name
field or in the pointsTo/data field in isolation.
For the host/name field it is a shortcut for the value "%fqdn%.".
When applying the template to a domain only, it represents
"example.com.". When applying with a sub-domain (host) it represents
"subdomain.example.com.".
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Note: The trailing dot here is equal to the DNS master file notation
[RFC1035], which indicates the value is absolute. Without the
trailing ".", the value in this field is relative to the
[host.]example.com value.
For the pointsTo/data field it is a shortcut for for the "%fqdn%".
When appling the template to a domain only, it represents
"example.com". When applying with a sub- domain (host) it represents
"subdomain.example.com".
Note: The pointsTo and data files are always absolute for these
fields.
It is noted that as a best practice the variable portions should be
constrained to as small as possible a portion of the resulting DNS
record.
For example, say a Service Provider requires a CNAME of one of three
values for their users: s01.example.com, s02.example.com, and
s03.example.com.
The value in the template could simply contain %servercluster%, and
the fully qualified string passed in. Alternatively, the value in
the template could contain %var%.example.com and a value of 01, 02,
or 03 passed in. By placing more fixed data into the template, the
template is more secure.
Each record will contain the following elements.
+===========+======+=========================+======================+
|Data |Type |Key |Description |
|Element | | | |
+===========+======+=========================+======================+
|*Type* |enum |type |(REQUIRED) Describes |
| | | |the type of record in |
| | | |DNS, or the operation |
| | | |impacting DNS. |
| | | |Valid values include: |
| | | |A, AAAA, CNAME, MX, |
| | | |TXT, SRV, or SPFM. |
| | | |The DNS provider MUST |
| | | |support the core set |
| | | |of records A, AAAA, |
| | | |CNAME, MX, TXT, SRV. |
| | | |The DNS provider |
| | | |SHOULD support SPFM |
| | | |record for high |
| | | |interoperability with |
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| | | |existing templates |
| | | | |
| | | |All other record types|
| | | |MAY be specified by |
| | | |type name as listed in|
| | | |IANA registry for DNS |
| | | |Resource Record (RR) |
| | | |TYPEs. Unknown record|
| | | |types MAY be specified|
| | | |as per [RFC3597] by |
| | | |the word "TYPE" |
| | | |immediately followed |
| | | |by the decimal RR type|
| | | |number, with no |
| | | |intervening |
| | | |whitespace. Support |
| | | |for other record types|
| | | |is OPTIONAL. |
| | | |For each type, |
| | | |additional fields |
| | | |would be REQUIRED. |
| | | |* A: host, pointsTo, |
| | | |TTL |
| | | |* AAAA: host, |
| | | |pointsTo, TTL |
| | | |* CNAME: host, |
| | | |pointsTo, TTL (host |
| | | |MUST NOT be null or @ |
| | | |unless hostRequired is|
| | | |defined true for the |
| | | |template) |
| | | |* NS: host, pointsTo, |
| | | |TTL (host MUST NOT be |
| | | |null or @ unless |
| | | |hostRequired is |
| | | |defined true for the |
| | | |template) |
| | | |* TXT: host, data, |
| | | |TTL, txtConflict- |
| | | |MatchingMode, |
| | | |txtConflict- |
| | | |MatchingPrefix |
| | | |* MX: host, pointsTo, |
| | | |TTL, priority |
| | | |* SRV: name, target, |
| | | |TTL, priority, |
| | | |protocol, service, |
| | | |weight, port |
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| | | |* SPFM: host, spfRules|
| | | |* other record types: |
| | | |host, data, TTL |
+-----------+------+-------------------------+----------------------+
|*Group Id* |String|groupId |(OPTIONAL) This |
| | | |parameter identifies |
| | | |the group the record |
| | | |belongs to when |
| | | |applying changes. |
| | | |This must not contain |
| | | |variables. |
+-----------+------+-------------------------+----------------------+
|*Essential*|enum |essential |(OPTIONAL) This |
| | | |parameter indicates |
| | | |how the record is |
| | | |treated during |
| | | |conflict detection |
| | | |with existing |
| | | |templates. |
| | | |If the DNS Provider is|
| | | |not implementing |
| | | |applied template state|
| | | |in DNS this is |
| | | |ignored. |
| | | |Always (default) - |
| | | |record MUST be applied|
| | | |and kept with the |
| | | |template |
| | | |OnApply - record MUST |
| | | |be applied but can be |
| | | |later removed without |
| | | |dropping the whole |
| | | |template |
+-----------+------+-------------------------+----------------------+
|*Host* |String|host |(REQUIRED) The host |
| | | |for A, AAAA, CNAME, |
| | | |NS, TXT, MX and other |
| | | |unspecified record |
| | | |type values. |
| | | |This value is relative|
| | | |to the applied host |
| | | |and domain, unless |
| | | |trailed by a ".". |
| | | |A value of empty or @ |
| | | |indicates the root of |
| | | |the applied host and |
| | | |domain. In other |
| | | |words |
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| | | |"[host.]example.com.".|
| | | |This value should not |
| | | |contain variables |
| | | |unless absolutely |
| | | |necessary. This is |
| | | |discussed below. |
+-----------+------+-------------------------+----------------------+
|*Name* |String|name |The name for the SRV |
| | | |record. |
| | | |This value is relative|
| | | |to the applied host |
| | | |and domain. A value |
| | | |of empty or @ |
| | | |indicates the root of |
| | | |the applied host and |
| | | |domain. |
| | | |This value should not |
| | | |contain variables |
| | | |unless absolutely |
| | | |necessary. This is |
| | | |discussed below. |
+-----------+------+-------------------------+----------------------+
|*Points To*|String|pointsTo |The pointsTo location |
| | | |for A, AAAA, CNAME, NS|
| | | |and MX records. |
| | | |A value of empty or @ |
| | | |indicates the host and|
| | | |domain name being |
| | | |applied or |
| | | |[host.]example.com |
+-----------+------+-------------------------+----------------------+
|*TTL* |Int or|ttl |The time-to-live for |
| |string| |the record in DNS. |
| |repr. | |Valid for A, AAAA, |
| |of Int| |CNAME, NS, TXT, MX, |
| | | |and SRV records. In |
| | | |order to avoid |
| | | |operational |
| | | |unpredactibility of |
| | | |the template and the |
| | | |challenges outlined |
| | | |below this SHOULD NOT |
| | | |contain variables |
| | | |unless absolutely |
| | | |necessary. If it |
| | | |does, the variable |
| | | |MUST be included as |
| | | |string in the template|
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| | | |definition to build a |
| | | |valid JSON and the |
| | | |variable MUST be the |
| | | |only value content. |
| | | |Prefixes, suffixes or |
| | | |multiple variables |
| | | |MUST NOT be used. |
| | | |This value, no matter |
| | | |if variable or |
| | | |constant, is |
| | | |understood as "best |
| | | |effort" by DNS |
| | | |provider and MAY be |
| | | |limited or adjusted by|
| | | |local policy at |
| | | |runtime or during |
| | | |template onboarding, |
| | | |like applying a |
| | | |certain minimum or |
| | | |maximum value of TTL |
| | | |or an enumeration of |
| | | |TTL values supported |
| | | |by the DNS provider. |
| | | |The DNS provider |
| | | |SHOULD NOT reject |
| | | |template application |
| | | |because of invalid |
| | | |value, rather pick the|
| | | |nearest supported |
| | | |value or a default, in|
| | | |order to avoid |
| | | |necessity of per |
| | | |provider adjustment to|
| | | |the application flow. |
| | | |Support of variables |
| | | |in this field is |
| | | |OPTIONAL for DNS |
| | | |Provider. |
+-----------+------+-------------------------+----------------------+
|*Data* |String|data |The data for a TXT |
| | | |record in DNS. A |
| | | |value of empty or @ |
| | | |indicates the host and|
| | | |domain name being |
| | | |applied or |
| | | |[host.]example.com For|
| | | |any unspecified record|
| | | |type this field |
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| | | |contains the canonical|
| | | |presentation format of|
| | | |the given record. The|
| | | |representation SHALL |
| | | |follow [RFC3597] as |
| | | |generic or type- |
| | | |specific encoding. |
| | | |This MUST NOT be used |
| | | |for any record type |
| | | |explicitly listed in |
| | | |the Type field with |
| | | |specific data fields. |
+-----------+------+-------------------------+----------------------+
|*TXT |String|txtConflictMatchingMode |Describes how |
|Conflict | | |conflicts on the TXT |
|Matching | | |record are detected. |
|Mode* | | |Possible values are |
| | | |None, All, or Prefix. |
| | | |The default value is |
| | | |None. See below |
| | | |(Section 9.3). |
+-----------+------+-------------------------+----------------------+
|*TXT |String|txtConflictMatchingPrefix|The prefix to detect |
|Conflict | | |conflicts when |
|Matching | | |txtConflict- |
|Prefix* | | |MatchingMode is |
| | | |"Prefix". This MUST |
| | | |NOT contain variables.|
| | | |See below |
| | | |(Section 9.3). |
+-----------+------+-------------------------+----------------------+
|*Priority* |Int or|priority |The priority for an MX|
| |string| |or SRV record. This |
| |repr. | |MAY contain variable |
| |of Int| |but if it does the |
| | | |variable MUST be |
| | | |included as string in |
| | | |the template |
| | | |definition to build a |
| | | |valid JSON and the |
| | | |variable MUST be the |
| | | |only content of the |
| | | |value field. |
| | | |Prefixes, suffixes or |
| | | |multiple variables |
| | | |MUST NOT be used. |
| | | |Support of variables |
| | | |in this field is |
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| | | |OPTIONAL for DNS |
| | | |Provider. |
+-----------+------+-------------------------+----------------------+
|*Weight* |Int or|weight |The weight for the SRV|
| |string| |record. This MAY |
| |repr. | |contain variable but |
| |of Int| |if it does the |
| | | |variable MUST be |
| | | |included as string in |
| | | |the template |
| | | |definition to build a |
| | | |valid JSON and the |
| | | |variable MUST be the |
| | | |only content of the |
| | | |value field. |
| | | |Prefixes, suffixes or |
| | | |multiple variables |
| | | |MUST NOT be used. |
| | | |Support of variables |
| | | |in this field is |
| | | |OPTIONAL for DNS |
| | | |Provider. |
+-----------+------+-------------------------+----------------------+
|*Port* |Int or|port |The port for the SRV |
| |string| |record. This MAY |
| |repr. | |contain variable but |
| |of Int| |if it does the |
| | | |variable MUST be |
| | | |included as string in |
| | | |the template |
| | | |definition to build a |
| | | |valid JSON and the |
| | | |variable MUST be the |
| | | |only content of the |
| | | |value field. |
| | | |Prefixes, suffixes or |
| | | |multiple variables |
| | | |MUST NOT be used. |
| | | |Support of variables |
| | | |in this field is |
| | | |OPTIONAL for DNS |
| | | |Provider. |
+-----------+------+-------------------------+----------------------+
|*Protocol* |String|protocol |The protocol for the |
| | | |SRV record. |
+-----------+------+-------------------------+----------------------+
|*Service* |String|service |The symbolic name for |
| | | |the SRV record. |
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+-----------+------+-------------------------+----------------------+
|*Target* |String|target |The target for the SRV|
| | | |record. |
+-----------+------+-------------------------+----------------------+
|*SPF Rules*|String|spfRules |These are desired |
| | | |rules for the SPF TXT |
| | | |record. These rules |
| | | |will be merged with |
| | | |other SPFM records |
| | | |into final SPF TXT |
| | | |record. See |
| | | |Section 9.10. |
+-----------+------+-------------------------+----------------------+
Table 14: properties of the template record definition
9. Template Considerations
9.1. Template State in DNS
DNS Providers may chose to maintain state inside records in DNS
indicating the templates writing the records. Other providers may
chose to not maintain this state.
A DNS Provider that maintains this state may be able to provide an
improved experience for customers, telling them the services enabled.
They also may be able to have more advanced handling of conflicts.
To make the implementation burden reasonable for DNS Providers,
Domain Connect does not dictate the approach.
9.2. Disclosure of Changes and Conflicts
It is left to the discretion of the DNS Provider to determine what is
disclosed to the user when granting permission and/or applying
changes to DNS. This includes disclosing the records being applied
and the records that may be overwritten.
For changes being made, one DNS Provider may decide to simply tell
the user the name of the service being enabled. Another may decide
to display the records being set. And another may progressively
display both.
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For conflict detection, one DNS Provider may simply overwrite changed
records without warning. Another may detect conflicts and warn the
user of the records that will change. And another may implement
logic to further detect, warn, and remove any of the existing
templates that overlap with the new template once applied (this
assumes they are a DNS Provider that maintains template state in
DNS).
As an example, consider applying a template that sets two records
(recordA and recordB) into a zone. Next consider applying a second
template that overlaps with the first template (recordB and recordC).
If the DNS maintains template state and removes conflicting
templates, applying the second template would remove the first
template. Application of the second template would conflict with
recordB and the entire first template would be removed.
Manual changes made by the user at the DNS Provider may also have
appropriate warnings in place to prevent unwanted changes; with
overrides being possible and removal of conflicting templates.
For the synchronous flow, this happens while the user is present.
For the asynchronous flow, the consent UX is similar. However, the
changes are made later using the API and OAuth. The DNS Provider may
decide to detect conflicts and return these from the API without
applying the change using the proper response code. If the force
parameter is set, the changes must be applied regardless of
conflicts.
It is ultimately left to the DNS Provider to determine the amount of
disclosure and/or conflict detection. The only requirement is that
after a template is applied the new records must be applied in
totality.
A reasonable set of recommendations for the UX might consist of:
* The consent UX should inform the customer of the service that will
be enabled. If the customer want to know the specifics, the DNS
Provider could provide a "show details" link to the user. This
could display to them the specific records that are being set in
DNS.
* If there are conflicts, either at the template or record level,
the consent UX should warn the user about these conflicts. For
templates, this would be services that would be disabled. For
records, this would be records that would be deleted or
overwritten. This could be progressively disclosed.
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9.3. Record Types and Conflicts
Conflict detection done by the DNS provider prior to template
application has to take into consideration specifics of each DNS
record type. The rules outlined below ensure predictable conflict
resolution between DNS providers. Each rule applies to the records
on the very same host, unless specifed otherwise.
* CNAME record conflicts with TXT, MX, AAAA, A and existing CNAME
records, and any other records of these types conflict with an
existing CNAME record. Note: CNAME records cannot be at the root
of the zone.
* NS records conflict with all other records. This includes of the
same host, and for any record ending with the NS host. For
example, an NS record of foo will conflict with any foo, www.foo,
bar.foo, etc. Similarly all other record type conflict with NS
records in the same manner.
* MX, SRV records always conflict with records of the same type
* A and AAAA records conflict with any other A and/or AAAA record,
to avoid IPv4 and IPv6 pointing to different services.
* TXT records conflict detection is handled looking at
txtConflictMatchingMode parameter
- None: This indicates that the TXT records do not conflict with
any other TXT record. This is the default setting, if not
specified.
- All: This indicates that the TXT records conflict with any
other TXT record
- Prefix: This indicates that TXT record conflict with any other
TXT containing value starting with txtConflictMatchingPrefix
9.4. Apply, Re-apply, and Multi-Instance
There is an additional consideration for DNS Providers that maintain
the state of an applied template when re-applying a template.
To avoid unnecessary conflict warnings to the user, under normal use
when re-applying a template such a DNS Provider should remove the
previously applied template on the same host.
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This may not be desireable for all templates, as a limited set of
templates are designed to be applied multiple times. To faciliate
this the template can have the flag multiInstance (Section 8.2) set.
This tells the DNS Provider that the template is expected to be
written multiple times and that a re-apply MUST NOT remove previous
instances.
This setting only impacts DNS Providers that maintain applied
template state. DNS Providers that do not maintain applied template
state must rely on the normal conflict resolution rules, and this
flag has no impact.
9.5. Non-essential records
Typically a template specifies a list of DNS records which are
required for the service. There may be cases where some records are
only required for a very short period of time, and removing or
altering the record later (either by the end user or through
application of another template) should not trigger conflict
detection.
This can be controlled by the essential (Section 8.3) property of a
record in the template.
Again, this setting only impacts DNS Providers that maintain applied
template state.
9.6. Template Scope
For DNS Providers that maintain template state, an individual
template is scoped to the set of records applied to a fully qualified
domain. This includes the root domain and the host (aka sub-domain)
at apply time.
As an example, if a template is applied on domain=example.com=sub1 a
later application of the template on domain=example.com=sub2 must be
treated as a distinct template. If a conflict is detected later with
the records set into "sub2.example.com", only the records set with
this template would be removed.
9.7. Host/Name in Template
Template records contain the host name of the record to set into the
zone (called name for SRV records). This value must be considered
relative to the domain/host when the template is applied, unless
followed by a trailing ".".
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Consider a template record of type A with a host value of "xyz".
When the template is applied to a domain=example.com and an empty
host value, the resulting zone after the template is applied will
contain an A record of "xyz" (or "xyz.example.com." as absolute
domain name in DNS master file notation).
If the same template is applied to a domain=example.com and host=bar,
the zone will contain an A record of "xyz.bar" (or
"xyz.bar.example.com." as absolute domain name).
A value of @ for host in the template is a placeholder for an empty
value. In other words @ would point to "bar.example.com." when the
same template is applied to domain=example.com and host=bar.
9.8. PointsTo in Template
Template records of certain types contain the pointsTo value to set
in the zone. For record types such as CNAME where this can be a
fully qualified domain name.
A value of @ in pointsTo field in the template is a shortcut for the
fully qualified domain name of the domain/host being applied.
Consider a template record of type CNAME with a pointsTo value of
"@". After a template of domain=example.com and an empty host is
applied, the pointsTo value (or corresponding field) in the resulting
zone would be "example.com". After a template of domain=example.com
with host=bar is applied, the points to value would be
"bar.example.com".
Any domain in a pointsTo field in a template must be considered fully
qualified and not relative.
9.9. Variables
9.9.1. Variables and Host/Name in Template
While templates do allow for variables in a host or name field
values, these should be used very sparingly.
As an example, consider setting up hosting for a site. But instead
of applying the template to a domain/host, the name of the host is
placed as a variable in the template.
Such a template might contain an A record of the form:
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{
"type": "A",
"host": "%var%",
"pointsTo": "192.0.2.2",
"ttl": 1800
}
This template could be applied on a domain like example.com with the
var set to "sub", "sub1", "sub2", etc.
Application of this template would be at the domain level for
"example.com". This causes problems for application/re-application
of the template, conflict detection, and template removal.
Since this template would be applied to the domain only, DNS
providers that maintain template state would remove previous
instances of the template before re-application. This means applying
this template with var=sub would result in the A record for
sub.example.com to be set to the value 192.0.2.2. Later, applying
the template on "example.com" with the var=sub2 should remove the old
template before setting the new one. sub.example.com would be
removed, and sub2.example.com would be set to the value 192.0.2.2.
Furthermore, determining conflicts would be impossible when the user
is granting consent for asynchronous operations (OAuth). This is
because the host would be indeterminate.
To solve this problem, templates are scoped to a domain and a host
value. For synchronous operations, the host value is specified in
the url. For asynchronous operations, permissions are granted for
specific host values, whose value is later specified when applying
the template.
Note: There are some templates that utilize CNAME or TXT records with
host values containing some form of user identification for
validation of domain ownership, and these are often passed in
variables.
To support this use case, variables are allowed for the host name.
But only in this limited circumstance.
9.9.2. Variable Values
To allow for the use of the host name or domain name in templates,
the values of %host% and %domain% are available. A third value of
%fqdn% is also available. This value is the result of combining the
host and domain name with the necessary ".".
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For example, with the query string "domain=example.com=", %fqdn% in a
template would be "example.com", and with "domain=example.com=sub1",
%fqdn% in a template would be "sub1.example.com".
9.9.3. Variables and Security
As discussed, with variables consideration is necessary to prevent
certain styles of phishing attacks.
The more static the value in the template record, the more secure the
template. When static values are not possible, a carefully crafted
link could hijack DNS settings.
Mitigations to this are discussed above.
9.9.4. Variable Examples
Example template:
[{
"type": "CNAME",
"host": "www",
"pointsTo": "@",
"ttl": 1800
},
{
"type": "A",
"host": "@",
"pointsTo": "192.0.2.1",
"ttl": 1800
}]
Template applied with _domain_=example.com and _host_ parameter
missing or empty:
www 1800 IN CNAME example.com.
@ 1800 IN A 192.0.2.1
_alternatively_
www.example.com. 1800 IN CNAME example.com.
example.com. 1800 IN A 192.0.2.1
Template applied with _domain_=example.com and _host_=bar:
www.bar 1800 IN CNAME bar.example.com.
bar 1800 IN A 192.0.2.1
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_alternatively_
www.bar.example.com. 1800 IN CNAME bar.example.com.
bar.example.com. 1800 IN A 192.0.2.1
9.10. SPF TXT Record
9.10.1. What is SPF?
SPF stands for Sender Policy Framework specified in [RFC7208]. It is
a record that specifies a list of authorized host names and/or IP
addresses from which mail can originate from for a given domain name.
It manifests itself as a TXT record. The format of which starts with
v=spf1 followed by a list of "rules" of what to include/exclude. If
a rule passes, the mail is allowed. If it fails, it moves to the
next rule. Typical record might appear as:
v=spf1 include:policy.exampleprovider.example -all
This is an SPF record with two rules. The first rule indicates that
the rules for SPF record _policy.exampleprovider.example be included
in this record. The second rule is a catch all (_all_). The default
modifier for a rule is _pass_ (+). Other modifiers are _hard
failure_(-), _soft failure_ (~) and _neutral_ (?).
Note: A failure in SPF doesn't mean delivery won't happen, however
depending on the policies of the receiving system, messages
classified with _hard failure_ or _soft failure_ may not be delivered
or marked as spam.
The use of "all" at the end is pretty common, although some providers
mark it as ~ (soft fail) or ? (neutral). The reality is that a good
SPF record is tuned based on what services are attached to a domain.
Not just one individual service.
9.10.2. Multiple Services
If only one email sending service were active, the SPF record
recommended by the provider is sufficient. But mail from a domain
can often come from several different services.
A very typical use case might be end user mail and an email
newsletter service. Let's look at the SPF records recommended for
individual services.
Mailer1: v=spf1 include:spf.mailer1.example -all Newsletter1: v=spf1
include:_spf.newsletter.example ~all
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All of these examples use the include syntax. This is fairly common.
The use of all at the end is common, although is often inconsistent
with the modifier.
If a customer installed Mailer1 and Newsletter1, their combined SPF
record ought to be something like:
v=spf1 include:spf.mailer1.example include:_spf.newsletter.example
~all
We combined the two rules, and in this case picked the least
restrictive all modifier.
9.10.3. SPF Record Merging
The challenge with SPF records and Domain Connect is that an
individual service might recommend an SPF record. If only one
service were active, this would be accurate. But with several
services together only the DNS Provider is able to determine the
valid shape of a SPF TXT record.
One solution to this problem is to merge all related records. At the
highest level, this means taking everything between the "v=spf1" and
the "all" from each of the records and merging them together,
terminating with hard-coded modifier on _all_ at the end. For an SPF
record to fulfill it's purpose of protection against malicious email
delivery, Domain Connect advises a fixed modifier _"~"_ advising
lower rating of the messages from other sources not specified in SPF.
This setup offers a reasonable level of protection of mail delivery,
on the other side does not reject the message in case forwarding
facility is in place.
@ TXT v=spf1 include:spf.mailer1.example include:_spf.newsletter.exam
ple ~all
The other would be to write intermediate records, and reference these
locally.
r1.example.com. TXT v=spf1 include:spf.mailer1.example ~all
r2.example.com. TXT v=spf1 include:_spf.newsletter.example ~all
@ TXT v=spf1 include:r1.example.com include:r2.example.com ~all
There are advantages and disadvantages to both approaches. SPF
records have a limit of 10 DNS lookups and record length is limited
to 255 characters. So depending on the embedded records both
approaches might have advantages.
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The implementation would be left to the DNS Provider, but to
facilitate this SPF records must NOT be included in templates.
Instead, we introduce a new pseudo-record type in the template called
_SPFM_. This has the following attribute:
spfRules Determines the desired rules, basically everything but
leading "v=spf1" and trailing _all_ rule - see: SPF Rules
(Section 8.3)
When a template is added or removed with an _SPFM_ record in the
template, some code would need to take the aggregate value of all
_SPFM_ records in all templates applied as well as existing SPF TXT
record on the host and recalculate the resulting SPF TXT record. In
case several sources specify the same rule with a different policy
DNS Provider SHOULD apply the least restrictive one as a result.
_soft failure_ SHOULD be preferred over _hard failure_, _neutral_
SHOULD be preferred over _soft failure_.
DNS Provider SHOULD also allow the end user to modify the SPF record
after merging.
Due to merging step in between, the resulting SPF TXT records are
considered non-essential (see: Section 9.5). That means the user may
decide to override the final calculated value or remove the whole SPF
record. This action MUST NOT lead to removal of any related
templates in conflict detection and template integrity routines if
implemented by the DNS provider.
If the existing TXT record makes the merging operation not possible,
the DNS provider must handle this situation the same way as a
conflict and either let the end-user resolve it in the UX (both in
Synchronous and Asynchronous flow) or return the conflict as an error
in the Asynchronous flow unless the _force=true_ parameter is used,
effectively removing the existing record.
Service providers should avoid exact match checking content of TXT
SPF record, as it might be strongly influenced by the DNS Provider
merging strategy and user actions.
See Appendix A.6.
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9.10.4. Alternatives
Some DNS Providers may decide not to support the SPFM record. The
following alternative solution should allow general interoperability
of the templates for those providers: onboard the templates with SPFM
record in variable-compatible form using a regular TXT record with
content _"v=spf1 %spfRules% ~all"_, using property
_essential=OnApply_ set to avoid removal of the whole template by a
conflict.
9.11. Public Template Repository
9.11.1. General information
The Public Template Repository is an open accessible location where
Service Providers MAY publish their Service Templates in the format
specified in this specification. DNS Providers MAY support all of
the published templates, just a subset or none of them according to
own onboarding policies (see also: Section 10.1).
The template format is intended largely for documentation and
communication between the DNS Providers and Service Providers, and
there are no codified endpoints for creation or modification of these
objects. Instead, Domain Connect references a template by ID.
As such, DNS Providers may or may not use templates in this format in
their internal implementations. By defining a standard template
format, it is believed it will make it easier for Service Providers
to share their configuration across DNS Providers.
9.11.2. Repository Location
The repository of the templates is maintained under
https://github.com/Domain-Connect/templates.
9.11.3. File naming requirements
The file names in this repository MUST be all lower case, including
the providerId and serviceId. As a result, while the providerId and
serviceId can be mixed case, all providerIds and serviceIds in this
repository must be unique when lower case.
Templates MUST be named according the following pattern:
providerId.serviceId.json
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providerId: example.com
serviceId: WebsiteBuilder
Template file name: example.com.websitebuilder.json
9.11.4. Template Integrity
Implementers are responsible for data integrity and should use the
record type field to validate that variable input meets the criteria
for each different data type.
Hard-coded host names are the responsibility of the DNS Provider to
protect. That is, DNS Providers are responsible for ensuring that
host names do not interfere with known values (such as m. or www. or
mail.) or internal names that provide critical functionality that is
outside the scope of this specification.
10. General considerations
10.1. Onboarding
This specification is an open standard that describes the protocol,
messages and formats used to enable Domain Connect between a Service
Provider and a DNS Provider.
Any Service Provider is free to define and publish a template.
However, the terms and conditions for a DNS Provider onboarding a
Service Provider template is beyond the scope of this document. A
DNS Provider can be selective in what templates they support, can
require a contractual relationship, or even charge a fee for
onboarding.
One way a Service Provider can be selective in which DNS Providers
they accept is to implement a whitelist of providerIds. A Service
Provider who chooses to whitelist must use providerId to distinguish
between unique DNS Providers. The DNS providerId is typically a
domain name.
10.2. Case Sensitivity
All values are case sensitive. This includes variable names, values,
parameters and objects returned.
One exception is the domain/host name. This is because a fully
qualified domain name is case insensitive.
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The values for providerId/serviceId in the template and passed
through URIs in the path or query string are case sensitive.
Different rules apply to the file naming in the Public Template
Repository (Section 9.11.3).
11. Extensions/Exclusions
11.1. General information
Additional record types and/or extensions to records in the template
can be implemented on a per DNS Provider basis. However, care should
be taken when defining extensions so as to not conflict with other
protocols and standards. Certain record names are reserved for use
in DNS for protocols like DNSSEC (DNSKEY, RRSIG) [RFC9364] at the
registry level.
Defining these OPTIONAL extensions in an open manner as part of this
specification is done to provide consistency. The following are the
initial OPTIONAL extensions a DNS Provider/Service Provider may
support.
11.2. APEXCNAME
Some Service Providers desire the behavior of a CNAME record, but in
the apex record. This would allow for an A Record at the root of the
domain but dynamically determined at runtime.
The recommended record type for DNS Providers that wish to support
this is an APEXCNAME record. Additional fields included with this
record would include pointsTo and TTL.
Defining a standard for such functionality in DNS is beyond the scope
of this specification. But for DNS Providers that support this
functionality, using the same record type name across DNS Providers
allows template reuse.
11.3. Redirection
Some Service Providers desire a redirection service associated with
the A Record. A typical example is a service that requires a
redirect of the domain (e.g. example.com) to the www variant
(www.example.com). The www would often contain a CNAME.
Since implementation of a redirection service is typically simple, it
is recommended that service providers implement redirection on their
own. But for DNS Providers that have a redirection service,
supporting simple templates with this functionality may be desired.
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While technically not a "record" in DNS, when supporting this
OPTIONAL functionality it is recommended that this should be
implemented using two new record types.
REDIR301 and REDIR302 would implement 301 and 302 redirects
respectively. Associated with this record would be a single field
called the "target", containing the target url of the redirect.
11.4. Nameservers
Several service providers have asked for functionality supporting an
update to the nameserver records at the registry associated with the
domain.
When implementing this, two records should be provided. NS1 and NS2,
each containing a pointsTo argument.
It will be noted that a nameserver update would require that the DNS
Provider is the registrar. This is not always the case.
This functionality is again deemed as OPTIONAL and up to the DNS
Provider to determine if they will support this.
11.5. DS (DNSSEC)
Requests have been made to allow for updates to the DS record for
DNSSEC. This record is required at the registry to enable DNSSEC,
but can only be written by the registrar.
For DNS Providers that support this record, the record type should be
DS. Values will be keyTag, algorithm, digestType, and digest.
Again it should be noted that a DS update would require that the DNS
Provider is the registrar, and is again deemed as optional and up to
the DNS Provider to determine if they will support.
12. IANA Considerations
Per [RFC8552], please add the following entry to the "Underscored and
Globally Scoped DNS Node Names" registry:
+=========+================+================+
| RR Type | _NODE NAME | Reference |
+=========+================+================+
| TXT | _domainconnect | This document. |
+---------+----------------+----------------+
Table 15
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Implementation Status
This section is to be removed before publishing as an RFC.
DNS Providers
Open Source
* Server library (Python): https://github.com/Domain-Connect/
DomainConnectApplyZone
Priopriatery implementations
* ~20 providers, incl. GoDaddy, IONOS, Cloudflare, Squarespace
Domains (former Google), Wordpress.com or Plesk
* 35% of the .com zone (May'24)
Service Providers
Open Source
* Example service: https://exampleservice.domainconnect.org/
https://github.com/Domain-Connect/exampleservice
* Client library (Python): https://github.com/Domain-Connect/
domainconnect_python
Priopriatery implementations
* 300 templates from over 120 providers, incl. O365, Google
Workspace, Apple Cloud+, Weebly, Squarespace...
https://github.com/Domain-Connect/Templates
Change History
This section is to be removed before publishing as an RFC.
Change from draft-kowalik-regext-domainconnect-00 to draft-kowalik-
domainconnect-00
* Added possibility to specify any DNS record type in a generic
manner.
* Added possibility to define variables for numeric fields.
* Added IANA registration for _domainconnect record as per RFC8552
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Change from draft-carney-regext-domainconnect-03 to draft-kowalik-
regext-domainconnect-00
* Version synchronized with 2.2 version rev. 66 of the public Domain
Connect specification.
Change from -02 to -03
* Added width/height JSON values returned by DNS Provider Discovery.
* Corrected text of GET method for getting the authorization token.
* Added clarifying text to Group ID description parameter of the
apply template POST method. Quite a few minor edits and
clarifications that were found during implementation, especially
in the Implementation Considerations section.
Change from -01 to -02
* Added new GET method for Service Providers to determine if the DNS
Provider supports a specific template. Some other minor edits for
clarification.
Change from draft-carney-regext-domainconnect-00 to -01
* Minor edits and clarifications found during implementation.
Normative References
[RFC1035] Mockapetris, P., "Domain names - implementation and
specification", IETF, STD 13, DOI 10.17487/RFC1035,
BCP 13, RFC 1035, November 1987,
<https://www.rfc-editor.org/info/rfc1035>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", IETF, DOI 10.17487/RFC2119, BCP 14,
RFC 2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC7208] Kitterman, S., "Sender Policy Framework (SPF) for
Authorizing Use of Domains in Email, Version 1", IETF,
DOI 10.17487/RFC7208, RFC 7208, April 2014,
<https://www.rfc-editor.org/info/rfc7208>.
[RFC6749] Hardt, D., "The OAuth 2.0 Authorization Framework", IETF,
DOI 10.17487/RFC6749, RFC 6749, October 2012,
<https://www.rfc-editor.org/info/rfc6749>.
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[RFC3597] Gustafsson, A., "Handling of Unknown DNS Resource Record
(RR) Types", IETF, DOI 10.17487/RFC3597, RFC 3597,
September 2003, <https://www.rfc-editor.org/info/rfc3597>.
[RFC8552] Crocker, D., "Scoped Interpretation of DNS Resource
Records through "Underscored" Naming of Attribute Leaves",
IETF, DOI 10.17487/RFC8552, BCP 222, RFC 8552, March 2019,
<https://www.rfc-editor.org/info/rfc8552>.
Informative References
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", IETF, DOI 10.17487/RFC8174, BCP 14,
RFC 8174, May 2017,
<https://www.rfc-editor.org/info/rfc8174>.
[RFC9364] Hoffman, P., "DNS Security Extensions (DNSSEC)", IETF,
DOI 10.17487/RFC9364, BCP 237, RFC 9364, February 2023,
<https://www.rfc-editor.org/info/rfc9364>.
Appendix A. Examples
A.1. Example Template
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{
"providerId": "example.com",
"providerName": "Example Web Hosting",
"serviceId": "hosting",
"serviceName": "Wordpress by example.com",
"version": 1,
"logoUrl": "https://www.example.com/images/billthecat.jpg",
"description": "This connects your domain to our web hosting",
"records": [
{
"type": "A",
"groupId": "service",
"host": "www",
"pointsTo": "%var1%",
"ttl": 600
},
{
"type": "A",
"groupId": "service",
"host": "m",
"pointsTo": "%var2%",
"ttl": 600
},
{
"type": "CNAME",
"groupId": "service",
"host": "webmail",
"pointsTo": "%var3%",
"ttl": 600
},
{
"type": "TXT",
"groupId": "verification",
"host": "example",
"ttl": 600,
"data": "%var4%"
}
]
}
A.2. Example Records: Single static host record
Consider a template for setting a single host record. The records
section of the template would have a single record of type "A" and
could have a value of:
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[{
"type": "A",
"host": "www",
"pointsTo": "192.0.2.1",
"ttl": 600
}]
This would have no variable substitution and the application of this
template to a domain would simply set the host name "www" to the IP
address "192.0.2.1"
A.3. Example Records: Single variable host record for A
In the case of a template for setting a single host record from a
variable, the template would have a single record of type "A" and
could have a value of:
[{
"type": "A",
"host": "@",
"pointsTo": "198.51.100.%srv%",
"ttl": 600
}]
A query string with a key/value pair of
srv=2
would cause the application of this template to a domain to set the
host name for the apex A record to the IP address "198.51.100.2" with
a TTL of 600
A.4. Example Records: Unspecified record type CAA
This example shows how to include a set of unspecified record types
on an example of CAA records:
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[
{
"type": "CAA",
"host": "@",
"data": "0 issue \"ca1.example.net\"",
"ttl": 1800
},
{
"type": "CAA",
"host": "@",
"data": "0 issuewild \"ca2.example.\"",
"ttl": 1800
}
]
This would have no variable substitution and the application of this
template to a domain would add 2 CAA records.
A.5. Example: DNS Zone merging
Consider a DNS Zone before a template application:
$ORIGIN example.com.
@ 3600 IN SOA ns11.example.net. support.example.net. 2017050817 7200
1800 1209600 3600
@ 3600 IN NS ns11.example.net.
@ 3600 IN NS ns12.example.net.
@ 3600 IN A 192.0.2.1
@ 3600 IN A 192.0.2.2
@ 3600 IN AAAA 2001:db8:1234:0000:0000:0000:0000:0000
@ 3600 IN AAAA 2001:db8:1234:0000:0000:0000:0000:0001
@ 3600 IN MX 10 mx1.example.net.
@ 3600 IN MX 10 mx2.example.net.
@ 3600 IN TXT "v=spf1 a include:spf.example.org ~all"
www 3600 IN CNAME other.host.example.
Now application of the following template:
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[
{
"type":"A",
"host":"@",
"pointsTo":"203.0.113.2",
"ttl":"1800"
},
{
"type":"A",
"host":"www",
"pointsTo":"203.0.113.2",
"ttl":"1800"
},
{
"type":"SPFM",
"host":"@",
"spfRules":"a include:spf.hoster.example"
}
]
The following DNS Zone should be generated after the template is
applied:
$ORIGIN example.com.
@ 3600 IN SOA ns11.example.net. support.example.net. 2017050920 7200
1800 1209600 3600
@ 3600 IN NS ns11.example.net.
@ 3600 IN NS ns12.example.net.
@ 1800 IN A 203.0.113.2
@ 3600 IN MX 10 mx1.example.net.
@ 3600 IN MX 10 mx2.example.net.
@ 1800 IN TXT "v=spf1 a include:spf.example.org include:spf.hoster.ex
ample ~all"
www 1800 IN A 203.0.113.2
A.6. Example: SPF Record Merging
Consider a DNS Zone before a template application:
$ORIGIN example.com.
@ 3600 IN SOA ns11.example.net. support.example.net. 2017050817 7200
1800 1209600 3600
@ 3600 IN NS ns11.example.net.
@ 3600 IN NS ns12.example.net.
Now application of the following template of Mail service:
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[
{
"type":"MX",
"host":"@",
"priority": "10",
"pointsTo":"mx1.example.net",
"ttl":"1800"
},
{
"type":"MX",
"host":"www",
"priority": "10",
"pointsTo":"mx2.example.net",
"ttl":"1800"
},
{
"type":"SPFM",
"host":"@",
"spfRules":"a include:spf.example.net"
}
]
Expected result in the DNS Zone
$ORIGIN example.com.
@ 3600 IN SOA ns11.example.net. support.example.net. 2017050817 7200
1800 1209600 3600
@ 3600 IN NS ns11.example.net.
@ 3600 IN NS ns12.example.net.
@ 3600 IN MX 10 mx1.example.net.
@ 3600 IN MX 10 mx2.example.net.
@ 3600 IN TXT "v=spf1 a include:spf.example.net ~all"
In the next step application of the following template of Newsletter
service:
[
{
"type":"SPFM",
"host":"@",
"spfRules":"include:_spf.newsletter.example"
}
]
Expected result in the DNS Zone
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$ORIGIN example.com.
@ 3600 IN SOA ns11.example.net. support.example.net. 2017050817 7200
1800 1209600 3600
@ 3600 IN NS ns11.example.net.
@ 3600 IN NS ns12.example.net.
@ 3600 IN MX 10 mx1.example.net.
@ 3600 IN MX 10 mx2.example.net.
@ 3600 IN TXT "v=spf1 a include:spf.example.net include:_spf.newslett
er.
example ~all"
Authors' Addresses
P Kowalik
DENIC eG
Theodor-Stern-Kai 1
Frankfurt am Main
Germany
Email: pawel.kowalik@denic.de
URI: https://denic.de
A Blinn
Email: arnold@arnoldblinn.com
J Kolker
GoDaddy Inc.
14455 N. Hayden Rd. #219
Scottsdale,
United States of America
Email: jkolker@godaddy.com
URI: https://www.godaddy.com
S Kerola
Cloudflare, Inc.
101 Townsend St
San Francisco,
United States of America
Email: kerolasa@cloudflare.com
URI: https://cloudflare.com
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