Alternative DNS Certification Authority Authorization (CAA) Resource Record
draft-wicinski-lamps-caa-00

Abstract

[RFC6844] defines the Certification Authority Authorization (CAA) DNS Resource Record type to specify one or more Certification Authorities (CAs) authorized to issue certificates for that domain name. With large domains covering multiple web properties, defining all possible certificate authorities for the domain has security implications. It would be beneficial to define a CAA for individual host names. This will allow CAA records that can be managed with fine grain control.

This document provides an alternative CAA record using a _caa prefix label that will take precedent on a per Fully Qualified Domain Name (FQDN), if it exists. It will override any CAA record at the zone apex. This will not change current CAA record behavior, but will be an additional option.

Status of This Memo

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

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This Internet-Draft will expire on September 25, 2019.

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Table of Contents

• 1. Introduction
• 1.1. Definitions
• 2. The _caa prefix label
• 3. IANA Considerations
• 4. Normative References
• Author's Address

1. Introduction

In [RFC6844] the Certification Authority Authorization (CAA) DNS Resource Record is defined to allow a DNS domain name holder to specify the Certification Authorities (CAs) authorized to issue certificates for that domain name.

1.1. Definitions

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. The _caa prefix label

[_caa.www.example.com CAA 0 issue "ca.example.net"

_caa.www.example.com CNAME _caa.cdn.example.net

_]

3. IANA Considerations

IANA is requested to add an entry in the "Underscored and Globally Scoped DNS Node Names" Registry with the fields "RR Type" = "CAA" and "Node Name" = "_caa",

4. Normative References

Author's Address