The VERBATIM Digest Algorithm for DS records

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Table of Contents

1. Introduction

The currently defined DS Digest Algorithms take the input data and hash it into a fixed-length form using well defined hashing algorithms (several SHA variants, and one mostly unused GOST algorithm). That hashing operation makes any data inside the (C)DNSKEY record unreachable until that data is retrieved from the child zone. Thus, DS records do not actually convey information; they merely verify information that can be retrieved elsewhere.¶

A DS record set can only answer the question 'this data that I have here, do you recognise it?'. For several imagined use cases for signed data at the parent, this might not be sufficient.¶

This document introduces a new Digest Algorithm, proposed name VERBATIM (alternative suggestion: NULL). The VERBATIM Digest Algorithm takes the input data (DNSKEY owner name | DNSKEY RDATA per section 5.1.4 of [RFC4034]) and copies it unmodified into the DS Digest field.¶

2. Document work

This document lives on GitHub; proposed text and editorial changes are very much welcomed there, but any functional changes should always first be discussed on the IETF DNSOP WG mailing list.¶

3. Conventions and 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.¶

4. Implementation

The subsection titles in this section attempt to follow the terminology from [RFC8499] in as far as it has suitable terms. 'Implementation' is understood to mean both 'code changes' and 'operational changes' here.¶

5. Security Considerations

FIXME¶

6. Implementation Status

[RFC Editor: please remove this section before publication]¶

7. IANA Considerations

This document updates the IANA registry "Delegation Signer (DS) Resource Record (RR) Type Digest Algorithms" at https://www.iana.org/assignments/ds-rr-types/ds-rr-types.xhtml¶

The following entry is added to the registry:¶

+--------------+----------------+
| Value        | TBD            |
| Description  | VERBATIM       |
| Status       | OPTIONAL       |
| Reference    | RFC TBD2       |
+--------------+----------------+

8. Acknowledgements

Appendix A. Document history

Author's Address