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General Internet Engineering Task Force DNS DNSSEC RESINFO This document specifies a DNS Resolver Information Key (RFC 9606) for DNSSEC validation capability, "dnssecval".

Introduction RFC 9606 specifies a DNS resource record (RR) type RESINFO to allow resolvers to publish information about their capabilities and policies. This information is encoded as {key, value} pairs, with each information is unambiguously identified with a key. Keys are maintained in an IANA registry. This specification adds a new key, to indicate that the resolver validates with DNSSEC . Such key may be used, for example, by a DNS client to prefer resolvers that enable DNSSEC validation.

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.

The key "dnssecval" The name of the key is "dnssecval", for "DNSSEC validating [resolver]". The presence of this key indicates that the DNS resolver validates all answers with DNSSEC . Note that, per the rules for the keys defined in Section 6.4 of if there is no '=' in a key, then it is a boolean attribute, simply identified as being present, with no value. A resolver that announces this capability in a RESINFO record MAY add DNSSEC-specific EDE (Extended DNS Error Codes, ) to the value of the "exterr" key, e.g., "Unsupported DNSKEY Algorithm", "Unsupported DS Digest Type", and "DNSSEC Bogus". Refer to the "Extended DNS Error Codes" registry for a definitive list of these EDEs.

IANA Considerations TODO find how to make a table with XML, to do like RFC 9606 This document requests IANA to add the key "dnssecval", with the explanation text "The presence of the key name indicates that DNSSEC validation is enabled", and a reference to this document to the registry "DNS Resolver Information Keys" under the "Domain Name System (DNS) Parameters" registry group.

Security Considerations DNSSEC is a very important tool for the security of the DNS. Therefore it is important for users to know in advance whether the resolver they consider supports DNSSEC. It would be better to assume that every resolver validates (thus rendering this document useless) but it is not the case today. As with any information published in the DNS, the key in the RESINFO may be wrong or outdated. They should be regarded with care. The security considerations discussed in Section 7 of apply.

References Normative References Informative References

Acknowledgements Original idea by Marco Davids.