Applicability Statement: DNS Security (DNSSEC) DNSKEY Algorithm IANA Registry
draft-ietf-dnsext-dnssec-registry-fixes-08

Abstract

The DNS Security Extensions (DNSSEC) requires the use of cryptographic algorithm suites for generating digital signatures over DNS data. There is currently an IANA registry for these algorithms that is incomplete in that it lacks the implementation status of each algorithm. This document provides an applicability statement on algorithm implementation compliance status for DNSSEC implementations. This status is to measure compliance to this RFC only. This document replaces that registry table with a new IANA registry table for Domain Name System Security (DNSSEC) Algorithm Numbers that lists (or assigns) each algorithm's status based on the current reference.

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 November 27, 2011.

Copyright Notice

Copyright (c) 2011 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.

Table of Contents

• 1. Introduction
• 1.1. Requirements Language
• 2. The DNS Security Algorithm Number Sub-registry
• 2.1. Updates and Additions
• 2.2. Domain Name System (DNS) Security Algorithm Number Registry Table
• 2.3. Specifying New Algorithms and Updating Status of Existing Entries
• 3. IANA Considerations
• 4. Security Considerations
• 5. References
• Author's Address

1. Introduction

The Domain Name System (DNS) Security Extensions (DNSSEC) [RFC4033], [RFC4034], [RFC4035], [RFC4509], [RFC5155], and [RFC5702] uses digital signatures over DNS data to provide source authentication and integrity protection. DNSSEC uses an IANA registry to list codes for digital signature algorithms (consisting of a cryptographic algorithm and one-way hash function).

The original list of algorithm status is found in [RFC4034]. Other DNSSEC RFC's have added new algorithms or changed the status of algorithms in the registry. However, implementers must read through all the documents in order to discover which algorithms are considered wise to implement, which are not, and which algorithms may become widely used in the future. This document replaces the original list with a new table that includes the current compliance status for certain algorithms.

This compliance status indication is only to be considered for implementation, not deployment or operations. Operators are free to deploy any digital signature algorithm available in implementations or algorithms chosen by local security policies. This status is to measure compliance to this RFC only.

This document replaces the current IANA registry for Domain Name System Security (DNSSEC) Algorithm Numbers with a newly defined registry table. This new table (Section 2.2 below) contains a column that will list the current compliance status of each digital signature algorithm in the registry at the time of writing and assigns status for some algorithms used with DNSSEC that did not have an identified status in their specification. This document updates the following: [RFC2536], [RFC2539], [RFC3110], [RFC4034], [RFC4398], [RFC5155], [RFC5702], and [RFC5933].

1.1. Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].

2. The DNS Security Algorithm Number Sub-registry

The DNS Security Algorithm Number sub-registry (part of the Domain Name System (DNS) Security Number registry) will be replaced with the table below. This table is based on the existing DNS Security Algorithm Number sub-registry and adds a column that contains the current implementation status of the given algorithm.

There are additional differences to entries that are described in sub-section 2.1. The overall new registry table is in sub-section 2.2. The values for the compliance status were obtained from [RFC4034] with updates for algorithms specified after the original DNSSEC specification. If no status was listed in the original specification, this document assigns one.

2.1. Updates and Additions

This document updates three entries in the Domain Name System Security (DNSSEC) Algorithm Registry. They are:

The description for assignment number 4 is changed to "Reserved until 2020".

The description for assignment number 9 is changed to "Reserved until 2020".

The description for assignment number 11 is changed to "Reserved until 2020".

Registry entries 13-251 remains Unassigned.

The status of RSASHA1-NSEC3-SHA1 is set to RECOMMENDED TO IMPLEMENT. This is due to the fact that RSA/SHA-1 is a MUST IMPLEMENT. The status of RSA/SHA-256 and RSA/SHA-512 are also set to RECOMMENDED TO IMPLEMENT as it is believed that these algorithms will replace an older algorithm (e.g. RSA/SHA-1) that have a perceived weakness in its hash algorithm (SHA-1).

2.2. Domain Name System (DNS) Security Algorithm Number Registry Table

The Domain Name System (DNS) Security Algorithm Number registry is hereby specified as follows below. The new column is titled "Compliance to RFC TBD" (where TBD will change when published) as the IANA Registry table is not normative. The IANA registry table is only a reflection of the RFC, which is normative.

                                       Trans-  
                                 Zone  action  Compliance to
Number  Description    Mnemonic   Sign  Sign     RFC TBD1     Reference
------  -----------     ------    ----  -----  ------------   ---------
 0      Reserved                                              [RFC4398]
 1      RSA/MD5         RSAMD5     N     Y      MUST NOT      [RFC2537]
                                                IMPLEMENT
 2      Diffie-Hellman  DH         N     Y                    [RFC2539]
 3      DSA/SHA-1       DSASHA1    Y     Y                    [RFC2536]
 4      Reserved until
        2020
 5      RSA/SHA-1       RSASHA1    Y     Y      MUST          [RFC3110]
                                                IMPLEMENT
 6      DSA-NSEC3-SHA1  DSA-NSEC3  Y     Y                    [RFC5155]
                        -SHA1
 7      RSASHA1-NSEC3   RSASHA1-   Y     Y     RECOMMENDED    [RFC5155]
        -SHA1           NSEC3-                 TO IMPLEMENT
                        SHA1
 8      RSA/SHA-256     RSASHA256  Y     *     RECOMMENDED    [RFC5702]
                                               TO IMPLEMENT
 9      Reserved until
        2020
 10      RSA/SHA-512     RSASHA512  Y     *    RECOMMENDED    [RFC5702]
                                               TO IMPLEMENT
 11      Reserved until
        2020
 12      GOST R          GOST-ECC   Y     *                   [RFC5933]
        34.10-2001
13-251   Unassigned
 252     Reserved for    INDIRECT   N     N                   [RFC4034]
        Indirect keys
 253     private         PRIVATE    Y     Y                   [RFC4034]
        algorithm
 254     private         PRIVATEOID Y     Y                   [RFC4034]
        algorithm OID
 255     Reserved

Table rows where the compliance column is not filled in are left to the discretion of implementers. Their implementation (or lack thereof) therefore cannot be included when judging compliance to this document.

2.3. Specifying New Algorithms and Updating Status of Existing Entries

[RFC6014] establishes a parallel procedure for adding a registry entry for a new algorithm other than a standards track document. Algorithms entered into the registry using that procedure do not have a listed compliance status. Specifications that follow this path do not need to obsolete or update this document.

Adding a newly specified algorithm to the registry with a compliance status SHALL entail obsolescing this document and replacing the registry table (with the new algorithm entry). Altering the status column value of any existing algorithm in the registry SHALL entail obsoleting this document and replacing the registry table.

This document cannot be updated, only made obsolete and replaced by a successor document.

3. IANA Considerations

This document replaces the Domain Name System (DNS) Security Algorithm Numbers registry. The new registry table is in Section 2.2. In the column "Compliance to RFC TBD", "RFC TBD" should be changed to the official RFC when published.

The original Domain Name System (DNS) Security Algorithm Number registry is available at http://www.iana.org/assignments/dns-sec-alg-numbers.

4. Security Considerations

This document replaces the Domain Name System (DNS) Security Algorithm Numbers registry. It is not meant to be a discussion on algorithm superiority. No new security considerations are raised in this document.

5. References

Author's Address