Revised IANA Considerations for DNSSEC

Revised IANA Considerations for DNSSEC ICANN

paul.hoffman@icann.org

This document changes the review requirements needed to get DNSSEC algorithms and resource records added to IANA registries. It updates RFC 6014 to include hash algorithms for Delegation Signer (DS) records and NextSECure version 3 (NSEC3) parameters (for Hashed Authenticated Denial of Existence). It also updates RFCs 5155 and 6014, which have requirements for DNSSEC algorithms, and updates RFC 8624 to clarify the implementation recommendation related to the algorithms described in RFCs that are not on the standards track. The rationale for these changes is to bring the requirements for DS records and hash algorithms used in NSEC3 in line with the requirements for all other DNSSEC algorithms.

Introduction DNSSEC is primarily described in , , and . DNSSEC commonly uses another resource record beyond those defined in : NSEC3 . DS resource records were originally defined in , and that definition was obsoleted by . updates the requirements for how DNSSEC cryptographic algorithm identifiers in the IANA registries are assigned, reducing the requirements from "Standards Action" to "RFC Required". However, the IANA registry requirements for hash algorithms for DS records and for the hash algorithms used in NSEC3 records are still "Standards Action". This document updates those IANA registry requirements. (For a reference on how IANA registries can be updated in general, see .)

Requirements Language 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 when, and only when, they appear in all capitals, as shown here.

Update to RFC 6014 updates to bring the requirements for DS records and NSEC3 hash algorithms in line with the rest of the DNSSEC cryptographic algorithms by allowing any DS hash algorithms, NSEC3 hash algorithms, NSEC3 parameters, and NSEC3 flags that are fully described in an RFC to have identifiers assigned in the IANA registries. This is an addition to the IANA considerations in .

Update to RFC 8624 This document updates for all DNSKEY and DS algorithms that are not on the standards track. The second paragraph of currently says:

This document only provides recommendations with respect to mandatory-to-implement algorithms or algorithms so weak that they cannot be recommended. Any algorithm listed in the [DNSKEY-IANA] and [DS-IANA] registries that are not mentioned in this document MAY be implemented. For clarification and consistency, an algorithm will be specified as MAY in this document only when it has been downgraded from a MUST or a RECOMMENDED to a MAY.

That paragraph is now replaced with the following:

This document provides recommendations with respect to mandatory-to-implement algorithms, algorithms so weak that they cannot be recommended, and algorithms defined in RFCs that are not on the standards track. Any algorithm listed in the [DNSKEY-IANA] and [DS-IANA] registries that are not mentioned in this document MAY be implemented. For clarification and consistency, an algorithm will be specified as MAY in this document only when it has been downgraded from a MUST or a RECOMMENDED to a MAY.

This update is also reflected in the IANA considerations in .

IANA Considerations In the "Domain Name System Security (DNSSEC) NextSECure3 (NSEC3) Parameters" registry, the registration procedure for "DNSSEC NSEC3 Flags", "DNSSEC NSEC3 Hash Algorithms", and "DNSSEC NSEC3PARAM Flags" has been changed from "Standards Action" to "RFC Required", and this document has been added as a reference. In the "DNSSEC Delegation Signer (DS) Resource Record (RR) Type Digest Algorithms" registry, the registration procedure for "Digest Algorithms" has been changed from "Standards Action" to "RFC Required", and this document has been added as a reference.

Security Considerations Changing the requirements for adding security algorithms to IANA registries as described in this document will make it easier to add both good and bad algorithms to the registries. It is impossible to weigh the security impact of those two changes. Administrators of DNSSEC-signed zones and validating resolvers may have been making security decisions based on the contents of the IANA registries. This was a bad idea in the past, and now it is an even worse idea because there will be more algorithms in those registries that may not have gone through IETF review. Security decisions about which algorithms are safe and not safe should be made by reading the security literature, not by looking in IANA registries.

References Normative References Informative References

Acknowledgements , , , , and contributed to this document.