Movatterモバイル変換

Network Working Group                                         M. AndrewsRequest for Comments: 4431                   Internet Systems ConsortiumCategory: Informational                                        S. Weiler                                                            SPARTA, Inc.                                                           February 2006The DNSSEC Lookaside Validation (DLV) DNS Resource RecordStatus of This Memo   This memo provides information for the Internet community.  It does   not specify an Internet standard of any kind.  Distribution of this   memo is unlimited.Copyright Notice   Copyright (C) The Internet Society (2006).Abstract   This document defines a new DNS resource record, called the DNSSEC   Lookaside Validation (DLV) RR, for publishing DNSSEC trust anchors   outside of the DNS delegation chain.1.  Introduction   DNSSEC [1] [2] [3] authenticates DNS data by building public-key   signature chains along the DNS delegation chain from a trust anchor,   ideally a trust anchor for the DNS root.   This document defines a new resource record for publishing such trust   anchors outside of the DNS's normal delegation chain.  Use of these   records by DNSSEC validators is outside the scope of this document,   but it is expected that these records will help resolvers validate   DNSSEC-signed data from zones whose ancestors either aren't signed or   refuse to publish delegation signer (DS) records for their children.2.  DLV Resource Record   The DLV resource record has exactly the same wire and presentation   formats as the DS resource record, defined inRFC 4034, Section 5.   It uses the same IANA-assigned values in the algorithm and digest   type fields as the DS record.  (Those IANA registries are known as   the "DNS Security Algorithm Numbers" and "DS RR Type Algorithm   Numbers" registries.)Andrews & Weiler             Informational                      [Page 1]

RFC 4431                  DLV Resource Record              February 2006   The DLV record is a normal DNS record type without any special   processing requirements.  In particular, the DLV record does not   inherit any of the special processing or handling requirements of the   DS record type (described inSection 3.1.4.1 of RFC 4035).  Unlike   the DS record, the DLV record may not appear on the parent's side of   a zone cut.  A DLV record may, however, appear at the apex of a zone.3.  Security Considerations   For authoritative servers and resolvers that do not attempt to use   DLV RRs as part of DNSSEC validation, there are no particular   security concerns -- DLV RRs are just like any other DNS data.   Software using DLV RRs as part of DNSSEC validation will almost   certainly want to impose constraints on their use, but those   constraints are best left to be described by the documents that more   fully describe the particulars of how the records are used.  At a   minimum, it would be unwise to use the records without some sort of   cryptographic authentication.  More likely than not, DNSSEC itself   will be used to authenticate the DLV RRs.  Depending on how a DLV RR   is used, failure to properly authenticate it could lead to   significant additional security problems including failure to detect   spoofed DNS data.RFC 4034, Section 8, describes security considerations specific to   the DS RR.  Those considerations are equally applicable to DLV RRs.   Of particular note, the key tag field is used to help select DNSKEY   RRs efficiently, but it does not uniquely identify a single DNSKEY   RR.  It is possible for two distinct DNSKEY RRs to have the same   owner name, the same algorithm type, and the same key tag.  An   implementation that uses only the key tag to select a DNSKEY RR might   select the wrong public key in some circumstances.   For further discussion of the security implications of DNSSEC, seeRFC 4033,RFC 4034, andRFC 4035.4.  IANA Considerations   IANA has assigned DNS type code 32769 to the DLV resource record from   the Specification Required portion of the DNS Resource Record Type   registry, as defined in [4].   The DLV resource record reuses the same algorithm and digest type   registries already used for the DS resource record, currently known   as the "DNS Security Algorithm Numbers" and "DS RR Type Algorithm   Numbers" registries.Andrews & Weiler             Informational                      [Page 2]

RFC 4431                  DLV Resource Record              February 20065.  Normative References   [1]  Arends, R., Austein, R., Larson, M., Massey, D., and S. Rose,        "DNS Security Introduction and Requirements",RFC 4033,        March 2005.   [2]  Arends, R., Austein, R., Larson, M., Massey, D., and S. Rose,        "Resource Records for the DNS Security Extensions",RFC 4034,        March 2005.   [3]  Arends, R., Austein, R., Larson, M., Massey, D., and S. Rose,        "Protocol Modifications for the DNS Security Extensions",RFC 4035, March 2005.   [4]  Eastlake, D., Brunner-Williams, E., and B. Manning, "Domain Name        System (DNS) IANA Considerations",BCP 42,RFC 2929,        September 2000.Authors' Addresses   Mark Andrews   Internet Systems Consortium   950 Charter St.   Redwood City, CA  94063   US   EMail: Mark_Andrews@isc.org   Samuel Weiler   SPARTA, Inc.   7075 Samuel Morse Drive   Columbia, Maryland  21046   US   EMail: weiler@tislabs.comAndrews & Weiler             Informational                      [Page 3]

RFC 4431                  DLV Resource Record              February 2006Full Copyright Statement   Copyright (C) The Internet Society (2006).   This document is subject to the rights, licenses and restrictions   contained inBCP 78, and except as set forth therein, the authors   retain all their rights.   This document and the information contained herein are provided on an   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET   ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,   INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE   INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.Intellectual Property   The IETF takes no position regarding the validity or scope of any   Intellectual Property Rights or other rights that might be claimed to   pertain to the implementation or use of the technology described in   this document or the extent to which any license under such rights   might or might not be available; nor does it represent that it has   made any independent effort to identify any such rights.  Information   on the procedures with respect to rights in RFC documents can be   found inBCP 78 andBCP 79.   Copies of IPR disclosures made to the IETF Secretariat and any   assurances of licenses to be made available, or the result of an   attempt made to obtain a general license or permission for the use of   such proprietary rights by implementers or users of this   specification can be obtained from the IETF on-line IPR repository athttp://www.ietf.org/ipr.   The IETF invites any interested party to bring to its attention any   copyrights, patents or patent applications, or other proprietary   rights that may cover technology that may be required to implement   this standard.  Please address the information to the IETF at   ietf-ipr@ietf.org.Acknowledgement   Funding for the RFC Editor function is provided by the IETF   Administrative Support Activity (IASA).Andrews & Weiler             Informational                      [Page 4]