Internet DRAFT - draft-sah-resinfo-doh
draft-sah-resinfo-doh
Network Working Group P. Sood
Internet-Draft Google
Intended status: Standards Track R. Arends
Expires: November 23, 2019 P. Hoffman
ICANN
May 22, 2019
DNS Resolver Information: "doh"
draft-sah-resinfo-doh-00
Abstract
This document defines a name-value pair, "doh", for the "DNS Resolver
Information Self-publication" protocol described in draft-sah-
resolver-information. This name-value pair describes whether the
resolver acts as a DoH server and, if so, the URI template for it.
Status of This Memo
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This Internet-Draft will expire on November 23, 2019.
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the Trust Legal Provisions and are provided without warranty as
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Definitions . . . . . . . . . . . . . . . . . . . . . . . 2
2. Definition of the "doh" Name-value Pair . . . . . . . . . . . 2
3. Use of Data from the "doh" Name-value Pair . . . . . . . . . 3
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3
4.1. Entry for the "Registry for DNS Resolver Information" . . 3
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 4
6.1. Normative References . . . . . . . . . . . . . . . . . . 4
6.2. Informative References . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4
1. Introduction
[I-D.sah-resolver-information] defines a format for information about
a DNS resolver and protocols to get that information. Stub resolvers
and applications that can act as DoH clients [RFC8484] may want to
know the URI templates used by a resolver that is acting as a DoH
server.
1.1. Definitions
In this document, the term "resolver" without qualification means
"recursive resolver" as defined in [RFC8499]. Also, the term "stub"
is used to mean "stub resolver".
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.
2. Definition of the "doh" Name-value Pair
The "doh" name has a value of a JSON object. That object has the
following name-value pairs. The "templates" name MUST be present;
the "domain-to-match" name is OPTIONAL.
templates: array of strings. Each string is a URI template for the
DoH server. The array MAY have zero values; if so, this indicates
that the resolver does not support DoH. The values MUST NOT be
empty.
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domain-to-match: array of strings. Each string is a fully-qualified
domain name that is expected to appear in the certificate used for
TLS. These names can be used for matching in the TLS handshake if
the DoH client accesses the DoH server with a template that has an
IP address. The array MAY have zero values; if so, this indicates
that the certificate should only be matched using IP addresses as
subject names. The values MUST NOT be empty.
For example, a pair might look like:
{ "doh":
{ "domain-to-match": [ "resolver.example.net" ],
"templates: [ "https://resolver.example.net/dns-query{?dns}",
"https://192.0.1.2/dns-query{?dns}" ]
}
}
As another example, where the TLS certificate is expected to have
identifiers of IP addresses, not domain names:
{ "doh":
{ "templates: [ "https://192.0.1.2/dns-query{?dns}" ],
"domain-to-match": [ ]
}
}
3. Use of Data from the "doh" Name-value Pair
If the "template" array has more than one string, a client can
consider them all to be of equal value when finding a DoH server
associated with the resolver.
4. IANA Considerations
4.1. Entry for the "Registry for DNS Resolver Information"
This document adds one new entry to the "Registry for DNS Resolver
Information".
Name: doh
Value type: object
Specification: This document
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5. Security Considerations
The data in the "doh" object MUST be received from an authoritative
source, and MUST be authenticated. Currently, that means either
using DNSSEC validation if using DNS to get the data, or TLS
certificate validation if using DNS-over-TLS [RFC7858] or DNS-over-
HTTPS from the resolver itself.
6. References
6.1. Normative References
[I-D.sah-resolver-information]
Sood, P., Arends, R., and P. Hoffman, "DNS Resolver
Information Self-publication", draft-sah-resolver-
information-00 (work in progress), April 2019.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8484] Hoffman, P. and P. McManus, "DNS Queries over HTTPS
(DoH)", RFC 8484, DOI 10.17487/RFC8484, October 2018,
<https://www.rfc-editor.org/info/rfc8484>.
6.2. Informative References
[RFC7858] Hu, Z., Zhu, L., Heidemann, J., Mankin, A., Wessels, D.,
and P. Hoffman, "Specification for DNS over Transport
Layer Security (TLS)", RFC 7858, DOI 10.17487/RFC7858, May
2016, <https://www.rfc-editor.org/info/rfc7858>.
[RFC8499] Hoffman, P., Sullivan, A., and K. Fujiwara, "DNS
Terminology", BCP 219, RFC 8499, DOI 10.17487/RFC8499,
January 2019, <https://www.rfc-editor.org/info/rfc8499>.
Authors' Addresses
Puneet Sood
Google
Email: puneets@google.com
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Roy Arends
ICANN
Email: roy.arends@icann.org
Paul Hoffman
ICANN
Email: paul.hoffman@icann.org
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