Service binding and parameter specification via the DNS (DNS SVCB and HTTPS RRs)
draft-ietf-dnsop-svcb-https-01
DNSOP Working Group B. Schwartz
Internet-Draft Google
Intended status: Standards Track M. Bishop
Expires: January 14, 2021 E. Nygren
Akamai Technologies
July 13, 2020
Service binding and parameter specification via the DNS (DNS SVCB and
HTTPS RRs)
draft-ietf-dnsop-svcb-https-01
Abstract
This document specifies the "SVCB" and "HTTPS" DNS resource record
(RR) types to facilitate the lookup of information needed to make
connections to network services, such as for HTTPS origins. SVCB
records allow a service to be provided from multiple alternative
endpoints, each with associated parameters (such as transport
protocol configuration and keys for encrypting the TLS ClientHello).
They also enable aliasing of apex domains, which is not possible with
CNAME. The HTTPS RR is a variation of SVCB for HTTPS and HTTP
origins. By providing more information to the client before it
attempts to establish a connection, these records offer potential
benefits to both performance and privacy.
TO BE REMOVED: This proposal is inspired by and based on recent DNS
usage proposals such as ALTSVC, ANAME, and ESNIKEYS (as well as long
standing desires to have SRV or a functional equivalent implemented
for HTTP). These proposals each provide an important function but
are potentially incompatible with each other, such as when an origin
is load-balanced across multiple hosting providers (multi-CDN).
Furthermore, these each add potential cases for adding additional
record lookups in addition to AAAA/A lookups. This design attempts
to provide a unified framework that encompasses the key functionality
of these proposals, as well as providing some extensibility for
addressing similar future challenges.
TO BE REMOVED: This document is being collaborated on in Github at:
https://github.com/MikeBishop/dns-alt-svc [1]. The most recent
working version of the document, open issues, etc. should all be
available there. The authors (gratefully) accept pull requests.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Schwartz, et al. Expires January 14, 2021 [Page 1]
Internet-Draft SVCB and HTTPS RRs for DNS July 2020
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Copyright (c) 2020 IETF Trust and the persons identified as the
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Goals of the SVCB RR . . . . . . . . . . . . . . . . . . 5
1.2. Overview of the SVCB RR . . . . . . . . . . . . . . . . . 6
1.3. Parameter for Encrypted ClientHello . . . . . . . . . . . 7
1.4. Terminology . . . . . . . . . . . . . . . . . . . . . . . 7
2. The SVCB record type . . . . . . . . . . . . . . . . . . . . 7
2.1. Zone file presentation format . . . . . . . . . . . . . . 8
2.2. RDATA wire format . . . . . . . . . . . . . . . . . . . . 9
2.3. SVCB owner names . . . . . . . . . . . . . . . . . . . . 10
2.4. Modes . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.4.1. AliasMode . . . . . . . . . . . . . . . . . . . . . . 11
2.4.2. ServiceMode . . . . . . . . . . . . . . . . . . . . . 12
2.4.3. SvcPriority . . . . . . . . . . . . . . . . . . . . . 12
2.5. Special handling of "." in TargetName . . . . . . . . . . 12
2.5.1. AliasMode . . . . . . . . . . . . . . . . . . . . . . 13
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