Internet DRAFT - draft-latour-dnsoperator-to-rrr-protocol
draft-latour-dnsoperator-to-rrr-protocol
Network Working Group J. Latour
Internet-Draft CIRA
Intended status: Informational O. Gudmundsson
Expires: September 22, 2016 Cloudflare, Inc.
P. Wouters
Red Hat
M. Pounsett
Rightside Group, Ltd.
March 21, 2016
Third Party DNS operator to Registrars/Registries Protocol
draft-latour-dnsoperator-to-rrr-protocol-03.txt
Abstract
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 for the
Registrant in this situation 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 Registrant error and significant delays. 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.
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.
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Status of This Memo
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This Internet-Draft will expire on September 22, 2016.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Notional Conventions . . . . . . . . . . . . . . . . . . . . 4
2.1. Definitions . . . . . . . . . . . . . . . . . . . . . . . 4
2.2. RFC2119 Keywords . . . . . . . . . . . . . . . . . . . . 4
3. What is the goal? . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Why DNSSEC? . . . . . . . . . . . . . . . . . . . . . . . 4
3.2. How does a child signal its parent it wants DNSSEC Trust
Anchor? The child . . . . . . . . . . . . . . . . . . . 4
3.3. What checks are needed by parent? . . . . . . . . . . . . 5
4. OP-3-DNS-RR RESTful API . . . . . . . . . . . . . . . . . . . 5
4.1. Authentication . . . . . . . . . . . . . . . . . . . . . 6
4.2. Authorization . . . . . . . . . . . . . . . . . . . . . . 6
4.3. Base URL Locator . . . . . . . . . . . . . . . . . . . . 6
4.4. CDS resource . . . . . . . . . . . . . . . . . . . . . . 6
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4.4.1. Initial Trust Establishment (Enable DNSSEC
validation) . . . . . . . . . . . . . . . . . . . . . 6
4.4.2. Removing a DS (turn off DNSSEC) . . . . . . . . . . . 7
4.4.3. DS Maintenance (Key roll over) . . . . . . . . . . . 7
4.5. Tokens resource . . . . . . . . . . . . . . . . . . . . . 7
4.5.1. Setup Initial Trust Establishment with Challenge . . 8
4.6. Customized Error Messages . . . . . . . . . . . . . . . . 8
4.7. How to react to 403 on POST cds . . . . . . . . . . . . . 8
5. Security considerations . . . . . . . . . . . . . . . . . . . 8
6. IANA Actions . . . . . . . . . . . . . . . . . . . . . . . . 9
7. Internationalization Considerations . . . . . . . . . . . . . 9
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
8.1. Normative References . . . . . . . . . . . . . . . . . . 9
8.2. Informative References . . . . . . . . . . . . . . . . . 9
Appendix A. Document History . . . . . . . . . . . . . . . . . . 10
A.1. Version 03 . . . . . . . . . . . . . . . . . . . . . . . 10
A.2. Version 02 . . . . . . . . . . . . . . . . . . . . . . . 10
A.3. Version 01 . . . . . . . . . . . . . . . . . . . . . . . 10
A.4. Version 00 . . . . . . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction
Why is this needed? DNS registration systems today are designed
around making registrations easy and fast. After the domain has been
registered the 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 examples of
failures including the inability to upload DS records due to non-
support by Registrar interface, the registrant forgets/does-not
perform action but tools proceed with key roll-over without checking
that the new DS is in place. Another common failure is the DS record
is not removed when the DNS Operator changes from one that supports
DNSSEC signing to one that does not.
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.
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2. Notional Conventions
2.1. Definitions
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.
2.2. RFC2119 Keywords
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 [RFC2119].
3. What is the goal?
The primary goal is to use the DNS protocol to provide information
from child zone to the parent zone, to maintain the delegation
information. The precondition for this to be practical is that the
domain is DNSSEC signed.
In the general case there should be a way to find the right
Registrar/Registry entity to talk to but that does not exist.
Whois[] is the natural protocol to carry such information but that
protocol is unreliable and hard to parse. Its proposed successor
RDAP [RFC7480] has yet be deployed on most TLD's.
The preferred communication mechanism is to use is to use a REST
[RFC6690] call to start processing of the requested delegation
information.
3.1. Why DNSSEC?
DNSSEC [RFC4035] provides data authentication for DNS answers, having
DNSSEC enabled makes it possible to trust the answers. The biggest
stumbling block is deploying DNSSEC is the initial configuration of
the DNSSEC domain trust anchor in the parent, DS record.
3.2. How does a child signal its parent it wants DNSSEC Trust Anchor?
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
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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[RFC7344]
and its proposed extension [I-D.ietf-dnsop-maintain-ds].
Once the "parent" "sees" these records it SHOULD start acceptance
processing. This document will cover below how to make the CDS
records visible to the right parental agent.
We and [I-D.ogud-dnsop-maintain-ds] 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 a problem the parent has
ability to not add the DS.
3.3. What checks are needed by parent?
The parent upon receiving a signal that it check the child for desire
for DS record publication. The basic tests include,
1. 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 have additional tests, defined delays, queries over TCP,
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.
4. OP-3-DNS-RR RESTful API
The specification of this API is minimalist, but a realistic one.
Question: How to respond if the party contacted is not ALLOWED to
make the requested change?
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4.1. Authentication
The API does not impose any unique server authentication
requirements. The server authentication provided by TLS fully
addresses the needs. In general, for the API SHOULD be provided over
TLS-protected transport (e.g., HTTPS) or VPN.
4.2. Authorization
Authorization is out of 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 the scope. Registries
and registrars who plan to provide this service can, however,
implement their own policy such as IP white listing, API key, etc.
4.3. Base URL Locator
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.
4.4. CDS resource
Path: /domains/{domain}/cds {domain}: is the domain name to be
operated on
4.4.1. Initial Trust Establishment (Enable DNSSEC validation)
4.4.1.1. Request
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.
4.4.1.2. Response
o HTTP Status code 201 indicates a success.
o HTTP Status code 400 indicates a failure due to validation.
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o HTTP Status code 403 indicates a failure due to an invalid
challenge token.
o HTTP Status code 404 indicates the domain does not exist.
o HTTP Status code 500 indicates a failure due to unforeseeable
reasons.
4.4.2. Removing a DS (turn off DNSSEC)
4.4.2.1. Request
Syntax: DELETE /domains/{domain}/cds
4.4.2.2. Response
o HTTP Status code 200 indicates a success.
o HTTP Status code 400 indicates a failure due to validation.
o HTTP Status code 404 indicates the domain does not exist.
o HTTP Status code 500 indicates a failure due to unforeseeable
reasons.
4.4.3. DS Maintenance (Key roll over)
4.4.3.1. Request
Syntax: PUT /domains/{domain}/cds
4.4.3.2. Response
o HTTP Status code 200 indicates a success.
o HTTP Status code 400 indicates a failure due to validation.
o HTTP Status code 404 indicates the domain does not exist.
o HTTP Status code 500 indicates a failure due to unforeseeable
reasons.
4.5. Tokens resource
Path: /domains/{domain}/tokens {domain}: is the domain name to be
operated on
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4.5.1. Setup Initial Trust Establishment with Challenge
4.5.1.1. Request
Syntax: POST /domains/{domain}/tokens
A random token to be included as a _delegate TXT record prior
establishing the DNSSEC initial trust.
4.5.1.2. Response
o HTTP Status code 200 indicates a success. Token included in the
body of the response, as a valid TXT record
o HTTP Status code 404 indicates the domain does not exist.
o HTTP Status code 500 indicates a failure due to unforeseeable
reasons.
4.6. Customized Error Messages
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 Identifiying number/string that can be used to
track the requests.
#Using the definitions This section at the moment contains comments
from early implementers
4.7. How to react to 403 on POST cds
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.
5. Security considerations
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
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6. IANA Actions
URI ??? TBD
7. Internationalization Considerations
This protocol is designed for machine to machine communications
8. References
8.1. Normative References
[I-D.ietf-dnsop-maintain-ds]
Gu[eth]mundsson, O. and P. Wouters, "Managing DS records
from parent via CDS/CDNSKEY", draft-ietf-dnsop-maintain-
ds-00 (work in progress), December 2015.
[RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Protocol Modifications for the DNS Security
Extensions", RFC 4035, DOI 10.17487/RFC4035, March 2005,
<http://www.rfc-editor.org/info/rfc4035>.
[RFC7344] Kumari, W., Gudmundsson, O., and G. Barwood, "Automating
DNSSEC Delegation Trust Maintenance", RFC 7344, DOI
10.17487/RFC7344, September 2014,
<http://www.rfc-editor.org/info/rfc7344>.
8.2. Informative References
[I-D.ogud-dnsop-maintain-ds]
Gu[eth]mundsson, O. and P. Wouters, "Managing DS records
from parent via CDS/CDNSKEY", draft-ogud-dnsop-maintain-
ds-00 (work in progress), October 2015.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/
RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC6690] Shelby, Z., "Constrained RESTful Environments (CoRE) Link
Format", RFC 6690, DOI 10.17487/RFC6690, August 2012,
<http://www.rfc-editor.org/info/rfc6690>.
[RFC7480] Newton, A., Ellacott, B., and N. Kong, "HTTP Usage in the
Registration Data Access Protocol (RDAP)", RFC 7480, DOI
10.17487/RFC7480, March 2015,
<http://www.rfc-editor.org/info/rfc7480>.
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Appendix A. Document History
A.1. Version 03
Clarified based on comments and questions from early implementors
A.2. Version 02
Reflected comments on mailing lists
A.3. Version 01
This version adds a full REST definition this is based on suggestions
from Jakob Schlyter.
A.4. Version 00
First rough version
Authors' Addresses
Jacques Latour
CIRA
Email: jacques.latour@cira.ca
Olafur Gudmundsson
Cloudflare, Inc.
Email: olafur+ietf@cloudflare.com
Paul Wouters
Red Hat
Email: paul@nohats.ca
Matthew Pounsett
Rightside Group, Ltd.
Email: matt@conundrum.com
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