Third Party DNS operator to Registrars/Registries Protocol

Third Party DNS operator to Registrars/Registries Protocol CIRA

jacques.latour@cira.ca

Cloudflare, Inc.

olafur+ietf@cloudflare.com

Red Hat

paul@nohats.ca

Rightside Group, Ltd.

matt@conundrum.com

Applications regext dnssec delegation maintenance trust anchors There are several problems that arise in the standard Registrant/Registrar/Registry model when the operator of a zone is neither the Registrant nor the Registrar for the delegation. Historically the issues have been minor, and limited to difficulty guiding the Registrant through the initial changes to the NS records for the delegation. As this is usually a one time activity when the operator first takes charge of the zone it has not been treated as a serious issue. When the domain on the other hand uses DNSSEC it necessary to make regular (sometimes annual) changes to the delegation, in order to track KSK rollover, by updating the delegation's DS record(s). Under the current model this is prone to delays and errors. Even when the Registrant has outsourced the operation of DNS to a third party the registrant still has to be in the loop to update the DS record. There is a need for a simple protocol that allows a third party DNS operator to update DS and NS records in a trusted manner for a delegation without involving the registrant for each operation. This same protocol can be used by Registrants. The protocol described in this draft is REST based, and when used through an authenticated channel can be used to establish the DNSSEC Initial Trust (to turn on DNSSEC or bootstrap DNSSEC). Once DNSSEC trust is established this channel can be used to trigger maintenance of delegation records such as DS, NS, and glue records. The protocol is kept as simple as possible.

Why is this needed? DNS registration systems today are designed around making registrations easy and fast. After the domain has been registered there are really three options on who maintains the DNS zone that is loaded on the "primary" DNS servers for the domain this can be the Registrant, Registrar, or a third party DNS Operator. Unfortunately the ease to make changes differs for each one of these options. The Registrant needs to use the interface that the registrar provides to update NS and DS records. The Registrar on the other hand can make changes directly into the registration system. The third party DNS Operator on the hand needs to go through the Registrant to update any delegation information. Current system does not work well, there are many types of failures have been reported and they have been at all levels in the registration model. The failures result either inability to use DNSSEC or in validation failures that case the domain to become invalid and all users that are behind validating resolvers will not be able to to access the domain. The goal of this document is to create an automated interface that will reduce the friction in maintaining DNSSEC delegations.

For the purposes of this draft, a third-party DNS Operator is any DNS Operator responsible for a zone where the operator is neither the Registrant nor the Registrar of record for the delegation. Uses of the word 'Registrar' in this document may also be applied to resellers: an entity that sells delegations through a registrar with whom the entity has a reseller agreement.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in .

The primary goal is to have a protocol to establish a secure chain of trust that involves parties that are not in the traditional RRR EPP model, or when EPP is not used. In the general case there should be a way to find the right Registrar/Registry entity to talk to, but it does not exist. Whois[] is the natural protocol to carry such information but that protocol but is unreliable and hard to parse. Its proposed successor RDAP has yet be deployed on most TLD's. The preferred communication mechanism is to use is to use a REST call to start processing of the requested delegation information.

DNSSEC provides data authentication for DNS answers, having DNSSEC enabled makes it possible to trust the answers. The biggest obstacle in DNSSEC adoption is the initial configuration of the DNSSEC domain trust anchor at the parent, the DS record.

The child needs first to sign the domain, then the child can "upload" the DS record to its parent. The "normal" way to upload is to go through registration interface, but that fails frequently. The DNS Operator may not have access to the interface thus the registrant needs to relay the information. For large operations this does not scale, as evident in lack of Trust Anchors for signed deployments that are operated by third parties. The child can signal its desire to have DNSSEC validation enabled by publishing one of the special DNS records CDS and/or CDNSKEY and its proposed extension . Once the "parent" "sees" these records it SHOULD start acceptance processing. This document covers how to make the CDS records visible to the right parental agent. This document and argue that the publication of CDS/CDNSKEY record is sufficient for the parent to start the acceptance processing. The main point is to provide authentication thus if the child is in "good" state then the DS upload should be simple to accept and publish. If there is any problem the parent does not add the DS. In the event this protocols and its associated authentication mechanism does not address the Registrant's security requirements to create a secure Trust Anchor delegation then the Registrant always has recourse by submitting its DS record via its Registrar interface with EPP submission to the Registry.

The parent upon receiving a signal that it check the child for desire for DS record publication. The basic tests include,

1. Is the zone is signed 2. The zone has a CDS signed by a KSK referenced in the current DS, referring to a at least one key in the current DNSKEY RRset 3. All the name-servers for the zone agree on the CDS RRset contents Parents can perform additional tests, defined delays, queries over TCP, ensure zone delegation best practice as per and even ask the DNS Operator to prove they can add data to the zone, or provide a code that is tied to the affected zone. The protocol is partially-synchronous, i.e. the server can elect to hold connection open until the operation has concluded or it can return that it received the request. It is up to the child to monitor the parent for completion of the operation and issue possible follow-up calls.

The specification of this API is minimalist, but a realistic one. Registry Lock mechanisms that prevents domain hijacking block domains prevent certain attributes in the registry to be changed. This API may be denied access to change the DS records for domains that are Registry Locked (HTTP Status code 401).

The API does not impose any unique server authentication requirements. The server authentication provided by TLS fully addresses the needs. In general, the API SHOULD be provided over TLS-protected transport (e.g., HTTPS) or VPN.

Authorization is outside the scope of this document. The CDS records present in the zone file are indications of intention to sign/unsign/update the DS records of the domain in the parent zone. This means the proceeding of the action is not determined by who issued the request. Therefore, authorization is out of scope. Registries and registrars who plan to provide this service can, however, implement their own policy such as IP white listing, API key, etc.

The base URL for registries or registrars who want to provide this service to DNS Operators can be made auto-discoverable as an RDAP extension.

Path: /domains/{domain}/cds {domain}: is the domain name to be operated on

Syntax: POST /domains/{domain}/cds A DS record based on the CDS record in the child zone file will be inserted into the registry and the parent zone file upon the successful completion of such request. If there are multiple CDS records in the CDS RRset, multiple DS records will be added. Either the CDS/CDNSKEY or the DNSKEY can be used to create the DS record. Note: entity expecting CDNSKEY is still expected accept the /cds command.

HTTP Status code 201 indicates a success. HTTP Status code 400 indicates a failure due to validation. HTTP Status code 401 indicates an unauthorized resource access. HTTP Status code 403 indicates a failure due to an invalid challenge token. HTTP Status code 404 indicates the domain does not exist. HTTP Status code 500 indicates a failure due to unforeseeable reasons.

Syntax: DELETE /domains/{domain}/cds A null CDS or CDNSKEY record mean the entire DS RRset must be removed.

HTTP Status code 200 indicates a success. HTTP Status code 400 indicates a failure due to validation. HTTP Status code 401 indicates an unauthorized resource access. HTTP Status code 404 indicates the domain does not exist. HTTP Status code 500 indicates a failure due to unforeseeable reasons.

Syntax: PUT /domains/{domain}/cds Maintenance activities are performed based on the CDS available in the child zone. DS records may be added, removed. But the entire DS RRset must not be deleted.

Path: /domains/{domain}/tokens {domain}: is the domain name to be operated on

Syntax: POST /domains/{domain}/tokens A random token to be included as a _delegate TXT record prior establishing the DNSSEC initial trust.

HTTP Status code 200 indicates a success. Token included in the body of the response, as a valid TXT record HTTP Status code 404 indicates the domain does not exist. HTTP Status code 500 indicates a failure due to unforeseeable reasons.

Service providers can provide a customized error message in the response body in addition to the HTTP status code defined in the previous section. This can include an Identifying number/string that can be used to track the requests. #Using the definitions This section at the moment contains comments from early implementers

The basic reaction to a 403 on POST /domains/{domain}/cds is to issue POST /domains/{domain}/tokens command to fetch the challenge to insert into the zone.

Supplying the DS record as proof of control is not realistic since the domain is already publicly signed and the CDS/DS is readily available. Open question:?? JL?: It is not recommended the protocol be used with high profile domains such as TLDs and governments that are DNS operators. This protocol is meant to allow third party DNS operator to submit the initial DS in a trusted manner without involving the registrant. This protocol should increase the adoption of DNSSEC and get more zones to become validated thus overall the security gain outweighs the possible drawbacks. TBD This will hopefully get more zones to become validated thus overall the security gain out weights the possible drawbacks. risk of takeover ? risk of validation errors < declines transfer issues

URI ??? TBD

This protocol is designed for machine to machine communications

Rewrote Abstract and Into (MP) Introduced code 401 when changes are not allowed Text edits and clarifications.

Working group document same as 03, just track changed to standard

Clarified based on comments and questions from early implementors

Reflected comments on mailing lists

This version adds a full REST definition this is based on suggestions from Jakob Schlyter.

First rough version