ACME for Subdomains
draft-friel-acme-subdomains-01

Document Type Active Internet-Draft (individual)
Last updated 2020-01-20
Stream (None)
Intended RFC status (None)
Formats plain text pdf htmlized bibtex
Stream Stream state (No stream defined)
Consensus Boilerplate Unknown
RFC Editor Note (None)
IESG IESG state I-D Exists
Telechat date
Responsible AD (None)
Send notices to (None)
Network Working Group                                           O. Friel
Internet-Draft                                                 R. Barnes
Intended status: Standards Track                                   Cisco
Expires: July 23, 2020                                      T. Hollebeek
                                                                DigiCert
                                                        January 20, 2020

                          ACME for Subdomains
                     draft-friel-acme-subdomains-01

Abstract

   This document outlines how ACME can be used by a client to obtain a
   certificate for a subdomain identifier from a certificate 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 authority policy allows issuance of the subdomain
   certificate without explicit subdomain ownership proof.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on July 23, 2020.

Copyright Notice

   Copyright (c) 2020 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must

Friel, et al.             Expires July 23, 2020                 [Page 1]
Internet-Draft               ACME-SUBDOMAINS                January 2020

   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   2
   3.  ACME Workflow and Identifier Requirements . . . . . . . . . .   3
   4.  ACME Issuance of Subdomain Certificates . . . . . . . . . . .   4
     4.1.  newOrder and newAuthz Handling  . . . . . . . . . . . . .   5
     4.2.  Examples  . . . . . . . . . . . . . . . . . . . . . . . .   6
   5.  Resource Enhancements . . . . . . . . . . . . . . . . . . . .   7
     5.1.  Authorization Object  . . . . . . . . . . . . . . . . . .   7
     5.2.  Directory Object Metadata . . . . . . . . . . . . . . . .   8
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   8
     6.1.  Authorization Object Fields Registry  . . . . . . . . . .   8
     6.2.  Directory Object Metadata Fields Registry . . . . . . . .   8
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .   8
   8.  Informative References  . . . . . . . . . . . . . . . . . . .   8
   Appendix A.  CA Browser Forum Baseline Requirements . . . . . . .   9
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   9

1.  Introduction

   ACME [RFC8555] defines a protocol that a certificate authority (CA)
   and an applicant can use to automate the process of domain name
   ownership validation and X.509 (PKIX) 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.

   The following terms are used in this document:

   o  CA: Certificate Authority

   o  CSR: Certificate Signing Request

Friel, et al.             Expires July 23, 2020                 [Page 2]
Internet-Draft               ACME-SUBDOMAINS                January 2020

   o  FQDN: Fully Qualified Domain Name

3.  ACME Workflow and Identifier Requirements

   A typical ACME workflow for issuance of certificates is as follows:
Show full document text