ACME for Subdomains
draft-friel-acme-subdomains-03
Network Working Group O. Friel
Internet-Draft R. Barnes
Intended status: Standards Track Cisco
Expires: April 12, 2021 T. Hollebeek
DigiCert
M. Richardson
Sandelman Software Works
October 09, 2020
ACME for Subdomains
draft-friel-acme-subdomains-03
Abstract
This document outlines how ACME can be used by a client to obtain a
certificate for a subdomain identifier from a certification
authority. The client has fulfilled a challenge against a parent
domain but does not need to fulfil a challenge against the explicit
subdomain as certificate policy allows issuance of the subdomain
certificate without explicit subdomain ownership proof.
Status of This Memo
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This Internet-Draft will expire on April 12, 2021.
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Friel, et al. Expires April 12, 2021 [Page 1]
Internet-Draft ACME-SUBDOMAINS October 2020
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. ACME Workflow and Identifier Requirements . . . . . . . . . . 3
4. Open Items . . . . . . . . . . . . . . . . . . . . . . . . . 4
5. ACME Issuance of Subdomain Certificates . . . . . . . . . . . 5
5.1. Pre-Authorization . . . . . . . . . . . . . . . . . . . . 5
5.2. Illustrative Call Flow . . . . . . . . . . . . . . . . . 6
5.3. newOrder and newAuthz Handling . . . . . . . . . . . . . 7
5.4. Examples . . . . . . . . . . . . . . . . . . . . . . . . 8
6. Resource Enhancements . . . . . . . . . . . . . . . . . . . . 9
6.1. Authorization Object . . . . . . . . . . . . . . . . . . 9
6.2. Directory Object Metadata . . . . . . . . . . . . . . . . 9
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
7.1. Authorization Object Fields Registry . . . . . . . . . . 9
7.2. Directory Object Metadata Fields Registry . . . . . . . . 9
8. Security Considerations . . . . . . . . . . . . . . . . . . . 10
8.1. ACME Server Policy Considerations . . . . . . . . . . . . 11
9. Informative References . . . . . . . . . . . . . . . . . . . 11
Appendix A. CA Browser Forum Baseline Requirements Extracts . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction
ACME [RFC8555] defines a protocol that a certification authority (CA)
and an applicant can use to automate the process of domain name
ownership validation and X.509v3 (PKIX) [RFC5280] certificate
issuance. This document outlines how ACME can be used to issue
subdomain certificates, without requiring the ACME client to
explicitly fulfil an ownership challenge against the subdomain
identifiers - the ACME client need only fulfil an ownership challenge
against a parent domain identifier.
2. 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.
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