Movatterモバイル変換

Internet Engineering Task Force (IETF)                    O. GudmundssonRequest for Comments: 7218                                 Shinkuro Inc.Updates:6698                                                 April 2014Category: Standards TrackISSN: 2070-1721Adding Acronyms to Simplify Conversations aboutDNS-Based Authentication of Named Entities (DANE)Abstract   Experience has shown that people get confused when discussing the   three numeric fields of the TLSA record.  This document specifies   descriptive acronyms for the three numeric fields in TLSA records.   This document updates the format of the IANA registry created byRFC6698.Status of This Memo   This is an Internet Standards Track document.   This document is a product of the Internet Engineering Task Force   (IETF).  It represents the consensus of the IETF community.  It has   received public review and has been approved for publication by the   Internet Engineering Steering Group (IESG).  Further information on   Internet Standards is available inSection 2 of RFC 5741.   Information about the current status of this document, any errata,   and how to provide feedback on it may be obtained athttp://www.rfc-editor.org/info/rfc7218.Copyright Notice   Copyright (c) 2014 IETF Trust and the persons identified as the   document authors.  All rights reserved.   This document is subject toBCP 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.Gudmundsson                  Standards Track                    [Page 1]

RFC 7218           Adding Acronyms to DANE Registries         April 2014Table of Contents1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .22.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .22.1.  TLSA Certificate Usages Registry  . . . . . . . . . . . .32.2.  TLSA Selectors  . . . . . . . . . . . . . . . . . . . . .32.3.  TLSA Matching Types . . . . . . . . . . . . . . . . . . .43.  Examples of Usage . . . . . . . . . . . . . . . . . . . . . .43.1.  TLSA Records Using/Displaying the Acronyms  . . . . . . .43.2.  Acronym Use in a Specification Example  . . . . . . . . .44.  Security Considerations . . . . . . . . . . . . . . . . . . .45.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .46.  References  . . . . . . . . . . . . . . . . . . . . . . . . .56.1.  Normative References  . . . . . . . . . . . . . . . . . .56.2.  Informative References  . . . . . . . . . . . . . . . . .51.  Introduction   During discussions on how to add DNS-Based Authentication of Named   Entities (DANE) [RFC6698] technology to new protocols and services,   people were repeatedly confused as to what the numeric values stood   for and even the order of the fields of a TLSA record (note that TLSA   is not an acronym but a name).  This document updates the IANA   registry definition for the TLSA record to add a column containing an   acronym for each specified field, in order to reduce confusion.  This   document does not change the DANE protocol in any way.   It is expected that DANE parsers in applications and DNS software can   adopt parsing the acronyms for each field.2.  IANA Considerations   This document applies to the "DNS-Based Authentication of Named   Entities (DANE) Parameters" registry located at <http://www.iana.org/assignments/dane-parameters>.  IANA has added a column with an   acronym to each of the sub-registries.   [RFC6698] and this document are the referenced documents for the   three sub-registries.   As these acronyms are offered for human consumption, case does not   matter; it is expected that software that parses TLSA records will   handle upper-, mixed-, or lower-case characters as input.Gudmundsson                  Standards Track                    [Page 2]

RFC 7218           Adding Acronyms to DANE Registries         April 20142.1.  TLSA Certificate Usages Registry   The reference for this registry has been updated to include both   [RFC6698] and this document.    +-------+----------+--------------------------------+-------------+    | Value | Acronym  | Short Description              | Reference   |    +-------+----------+--------------------------------+-------------+    |   0   | PKIX-TA  | CA constraint                  | [RFC6698]   |    |   1   | PKIX-EE  | Service certificate constraint | [RFC6698]   |    |   2   | DANE-TA  | Trust anchor assertion         | [RFC6698]   |    |   3   | DANE-EE  | Domain-issued certificate      | [RFC6698]   |    | 4-254 |          | Unassigned                     |             |    |  255  | PrivCert | Reserved for Private Use       | [RFC6698]   |    +-------+----------+--------------------------------+-------------+                     Table 1: TLSA Certificate Usages2.2.  TLSA Selectors   The reference for this registry has been updated to include both   [RFC6698] and this document.       +-------+---------+--------------------------+-------------+       | Value | Acronym | Short Description        | Reference   |       +-------+---------+--------------------------+-------------+       |   0   | Cert    | Full certificate         | [RFC6698]   |       |   1   | SPKI    | SubjectPublicKeyInfo     | [RFC6698]   |       | 2-254 |         | Unassigned               |             |       |  255  | PrivSel | Reserved for Private Use | [RFC6698]   |       +-------+---------+--------------------------+-------------+                          Table 2: TLSA SelectorsGudmundsson                  Standards Track                    [Page 3]

RFC 7218           Adding Acronyms to DANE Registries         April 20142.3.  TLSA Matching Types   The reference for this registry has been updated to include both   [RFC6698] and this document.      +-------+-----------+--------------------------+-------------+      | Value | Acronym   | Short Description        | Reference   |      +-------+-----------+--------------------------+-------------+      |   0   | Full      | No hash used             | [RFC6698]   |      |   1   | SHA2-256  | 256 bit hash by SHA2     | [RFC6234]   |      |   2   | SHA2-512  | 512 bit hash by SHA2     | [RFC6234]   |      | 3-254 |           | Unassigned               |             |      |  255  | PrivMatch | Reserved for Private Use | [RFC6698]   |      +-------+-----------+--------------------------+-------------+                       Table 3: TLSA Matching Types3.  Examples of Usage   Two examples are described below.3.1.  TLSA Records Using/Displaying the Acronyms   _666._tcp.first.example.  TLSA PKIX-TA CERT SHA2-512 {blob}   _666._tcp.second.example.  TLSA DANE-TA SPKI SHA2-256 {blob}3.2.  Acronym Use in a Specification Example   Protocol FOO only allows TLSA records using PKIX-EE and DANE-EE, with   selector SPKI, and using SHA2-512.4.  Security Considerations   This document only changes registry fields and does not change the   behavior of any protocol.  The hope is to reduce confusion, which   would lead to better specification and operations.5.  Acknowledgements   Scott Schmit offered really good suggestions to decrease the   possibility of confusion.  Viktor Dukhovni provided comments from the   expert point of view.  Jim Schaad, Wes Hardaker, and Paul Hoffman   provided feedback during WGLC.  Dan Romascanu and Tobias Gondrom   pointed out a few defects during the IESG last call.Gudmundsson                  Standards Track                    [Page 4]

RFC 7218           Adding Acronyms to DANE Registries         April 20146.  References6.1.  Normative References   [RFC6698]  Hoffman, P. and J. Schlyter, "The DNS-Based Authentication              of Named Entities (DANE) Transport Layer Security (TLS)              Protocol: TLSA",RFC 6698, August 2012.6.2.  Informative References   [RFC6234]  Eastlake, D. and T. Hansen, "US Secure Hash Algorithms              (SHA and SHA-based HMAC and HKDF)",RFC 6234, May 2011.Author's Address   Olafur Gudmundsson   Shinkuro Inc.   4922 Fairmont Av, Suite 250   Bethesda, MD  20814   USA   EMail: ogud@ogud.comGudmundsson                  Standards Track                    [Page 5]