Internet DRAFT - draft-shoemaker-caa-ip
draft-shoemaker-caa-ip
Network Working Group R. Shoemaker
Internet-Draft ISRG
Intended status: Standards Track September 13, 2017
Expires: March 17, 2018
Certification Authority Authorization (CAA) Validation for IP Addresses
draft-shoemaker-caa-ip-01
Abstract
The Certification Authority Authorization (CAA) RFC specifies a
method for users to restrict which Certificate Authorities (CAs) are
authorized to issue certificates for their DNS domain names. This
document extends that specification to provide a method for holders
of IP addresses to do the same.
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 http://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 March 17, 2018.
Copyright Notice
Copyright (c) 2017 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
(http://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
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.
Shoemaker Expires March 17, 2018 [Page 1]
Internet-Draft CAA-IP September 2017
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . 2
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3
4.1. Certification Authority Restriction Properties . . . . . 3
5. Normative References . . . . . . . . . . . . . . . . . . . . 3
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 4
1. Introduction
This document describes an extension to RFC 6844 [RFC6844] which
allows for the use of Certification Authority Authorization DNS
Records to be used to restrict issuance of certificates to IP
addresses instead of just DNS names. This is done by defining a new
lookup mechanism for IPv4 and IPv6 addresses as previously a
mechanism only existed for DNS names.
2. Terminology
In this document, the key words "MUST", "MUST NOT", "REQUIRED",
"SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
and "OPTIONAL" are to be interpreted as described in BCP 14, RFC 2119
[RFC2119].
3. Mechanism
Before issuing a certificate containing a IP address a compliant CA
MUST check for the relevant CAA Resource Record set. If such a
record set exists a CA MUST NOT issue a certificate unless the
records in the set are consistent with the request and the policies
of the CA.
A certificate request MAY specify more than one IP address in which
case CAs MUST verify the CA Resource Record set for all the IP
addresses specified in the request.
As defined in RFC 2818 [RFC2818] IP addresses in certificates must
match exactly with the requested URI so CAs MUST NOT consider CAA
records with the "issuewild" tag to be part of the relevant Resource
Record set for a IP address.
Unlike the mechanism defined in RFC 6844 [RFC6844] this mechanism
doesn't involve climbing the DNS tree and only requires querying a
single DNS name. The relevant Resource Record set for a given IP
address is found by querying the reverse mapping zone for the IP for
CAA records.
Shoemaker Expires March 17, 2018 [Page 2]
Internet-Draft CAA-IP September 2017
Given a certificate request containing the IPv6 address "2001:db8::1"
the relevant query for the reverse mapping within the IP6.ARPA
[RFC3596] zone would be:
1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa. IN CAA
And for a request containing the IPv4 address "192.0.2.1" the
relevant query for the reverse mapping within the IN-ADDR.ARPA
[RFC1034] zone would be:
1.2.0.192.in-addr.arpa. IN CAA
When doing queries CAs SHOULD either use a resolver that chases CNAME
records or manually chase CNAMEs themselves in order to allow for
zone delegations [RFC2317].
4. IANA Considerations
4.1. Certification Authority Restriction Properties
Change the contents of the Meaning column for the "issue" Tag to say
"Authorization Entry by Domain or IP address" and add "draft-
shoemaker-caa-ip" to the References column.
5. Normative References
[RFC1034] Mockapetris, P., "Domain names - concepts and facilities",
STD 13, RFC 1034, DOI 10.17487/RFC1034, November 1987,
<https://www.rfc-editor.org/info/rfc1034>.
[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>.
[RFC2317] Eidnes, H., de Groot, G., and P. Vixie, "Classless IN-
ADDR.ARPA delegation", BCP 20, RFC 2317,
DOI 10.17487/RFC2317, March 1998, <https://www.rfc-
editor.org/info/rfc2317>.
[RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818,
DOI 10.17487/RFC2818, May 2000, <https://www.rfc-
editor.org/info/rfc2818>.
[RFC3596] Thomson, S., Huitema, C., Ksinant, V., and M. Souissi,
"DNS Extensions to Support IP Version 6", STD 88,
RFC 3596, DOI 10.17487/RFC3596, October 2003,
<https://www.rfc-editor.org/info/rfc3596>.
Shoemaker Expires March 17, 2018 [Page 3]
Internet-Draft CAA-IP September 2017
[RFC6844] Hallam-Baker, P. and R. Stradling, "DNS Certification
Authority Authorization (CAA) Resource Record", RFC 6844,
DOI 10.17487/RFC6844, January 2013, <https://www.rfc-
editor.org/info/rfc6844>.
Author's Address
Roland Bracewell Shoemaker
ISRG
Email: roland@letsencrypt.org
Shoemaker Expires March 17, 2018 [Page 4]