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Network Working Group                                           E. LewisRequest for Comments: 3130                                      NAI LabsCategory: Informational                                        June 2001Notes from the State-Of-The-Technology: DNSSECStatus 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 (2001).  All Rights Reserved.Abstract   This is a memo of a DNSSEC (Domain Name System Security Extensions)   status meeting.1.0 Introduction   A meeting of groups involved in the development of the DNS Security   Extensions (DNSSEC) was held in conjunction with the 49th IETF.  The   discussion covered the extent of current efforts, a discussion of   what questions are being asked of DNSSEC, and what is needed by the   IETF to progress the definition to the Draft Standard level.   DNSSEC [RFC 2535] has been under consideration for quite a few years,   withRFC 2535 being the core of the most recent definition.  DNSSEC   is part of the charter of two working groups, DNSEXT and DNSOP.   ISC's BIND v8.2 implemented part of the specification, BIND v9   represents the first full implementation.  In 1999 and 2000, more   than a half dozen workshops have been held to test the concepts and   the earliest versions of implementations.  But to date, DNSSEC is not   in common use.   The current collective wisdom is that DNSSEC is 1) important, 2) a   buzzword, 3) hard, 4) immature.  To capture the true state of the   technology and identify where work is needed, an informal gathering   of groups known to be involved in DNSSEC was held in conjunction with   the 49th IETF.  The attendees represented NLnet Labs, The Foundation   for Internet Infrastructure, RIPE NCC, ARIN, CAIRN (ISI and NAI   Labs), NIST, DISA, RSSAC, Network Associates and Verisign   (COM/NET/ORG TLDs).Lewis                        Informational                      [Page 1]

RFC 3130              DNSSEC Status Meeting Report             June 2001   The agenda of the meeting consisted of three items.  Reports from   each group on their current research goals were followed by a   discussion of questions being asked of DNSSEC.  Finally, with   reaching Draft Standard status as a goal, what was needed to make   this happen was considered.   This report is not simply a transcript of the meeting, it is a   summary.  Some of the information presented here was obtained in   direct contact with participants after the meeting.1.1 What does the term "DNSSEC" mean?   One of the comments made during discussions is that DNSSEC does not   refer to just one monolithic technology.  The term has come to refer   to "toolbox" of techniques and methodologies, that when used properly   can improve the integrity of the DNS.  Given this observation, it can   be seen that some portions of DNSSEC are evolving much more rapidly   than other portions.  In particular, TSIG [RFC 2845] has certainly   reached a level "being deployable" for zone transfers.   The following four components are considered to be part of DNSSEC.   The concept of digital signature protection of DNS traffic as   described inRFC 2535 and a few support documents (such as [RFC   3008]), which is designed to protect the transfer of data on an   Internet scale.  The concept of protecting queries and responses   through the less-scalable but more efficient TSIG mechanism [RFC   2845], which has applicability to zone transfers, DHCP registrations,   and other resolver to name server traffic.  Secure dynamic updates   [RFC 3007], by virtue of using TSIG, can be considered to be part of   DNSSEC.  Finally, the definition of the CERT resource record [RFC   2538] gives DNS the ability to become a distribution mechanism for   security data.   This definition of the components of DNSSEC is in no way definitive.   To be honest, this is a somewhat artificial grouping.  DNSSEC does   not encompass all of the security practiced in DNS today, for   example, the redefinition of when and how data is cached [RFC 2181],   plays a big role in hardening the DNS system.  The four elements of   DNSSEC described in the previous paragraph are grouped together   mostly because they do interrelate, but also they were developed at   approximately the same time.2.0 Group Reports   The first part of the meeting consisted of reports of goals.  From   this a taxonomy of efforts has been made to see if there are gaps in   the work.Lewis                        Informational                      [Page 2]

RFC 3130              DNSSEC Status Meeting Report             June 20012.1 NLnet Labs   Efforts by NLnet Labs are directed towards yielding an understanding   of the impact of DNSSEC on ccTLDs, specifically .de (Germany), .nl   (The Netherlands), and .se (Sweden).  Work to date has studied the   problem of applying digital signatures and NXT records to a zone.   The conclusion drawn is that there are no real problems regarding   memory or CPU speed when signing large zones, not even for ".com."   NLnet Labs has offered to work with Verisign to examine this further.   NLnet Labs is trying to define and document procedures for TLD   registries, registrars and registrants to properly handle actions   like zone-resigning and key-rollover at the root, TLD, and lower   levels.  The outcome so far is that the DNSOP Roll Over proposal   seems impractical or possibly even impossible to implement at large   TLDs.  NLnet Labs will produce a draft on an alternative KEY+SIG   handling scheme where SIGs are only kept in the zone where the   corresponding zone-KEY is located.  This scheme reduces the necessary   actions for resigning zones from 2 levels (current zone and all   children) to 1 level (current zone), and for key-rollover from 3   levels (parent, current zone and all children) to 2 levels (parent   and current zone).2.2 Verisign   Verisign's registry operations and corporate components have been   investigating what DNSSEC means to very large zones, not just from a   hardware point of view, but from an institutional point of view.   With the service of providing delegations already commercialized,   they are attempting to define what it would take to provide a DNSSEC   service.  An important issue is the parent validation of each   delegated zone's keys.2.3 The Foundation for Internet Infrastructure   The Foundation for Internet Infrastructure, an organization in   Sweden, is running a project with two parts.  One part is directed at   the "topology" of the participants in DNSSEC, the other part of the   project is directed towards general development of tools.   The study is examining the administrative issues of running DNSSEC.   One issue is the possible 4-party interaction in the use of DNSSEC.   The four parties are the registry, the registrar, the registrant, and   the DNS operator.  Of these four parties, any combination may occur   within one entity, such as a registrant that operates their own DNS   as part of their information technology department.Lewis                        Informational                      [Page 3]

RFC 3130              DNSSEC Status Meeting Report             June 2001   The other part of the study is looking at what happens in the   resolver.  Goals include DNSSEC-enabling tools such as ISAKMPd (an   IPSEC key negotiation software) secure NTP4, and e-mail.  Part of   this effort is implemented in the sigz.net experiment, information on   this exists at www.sigz.net.2.4 RSSAC   The RSSAC (Root Server System Advisory Committee) has come to the   conclusion that TSIG is worthwhile and should be deployed.  There is   no schedule for deployment, however.   As for the rest of DNSSEC, there is a need to better understand the   impact of the new features before being introduced into production.   Currently issues regarding potential testbeds are being documented.   Two fundamental assumptions are that a DNSSEC testbed involving the   root servers is desirable and that such a testbed would allow for   long term testing.  The latter assumption is based upon the need to   understand how repeated zone key validations can occur at multiple   independent levels of the DNS hierarchy.2.5 CAIRN   CAIRN (Collaborative Advanced Interagency Research Network) is a   DARPA-sponsored network for collaborative research.  A funded   activity that involves DNSSEC is FMESHD, shorthand for Fault-Tolerant   Mesh of Trust in DNSSEC.  The effort of this activity is to determine   a means of building a resolver's chain of trust when some of the DNS   tree is unavailable or unsecured.  An early deliverable of this is an   extension of secure shell to retrieve keys from DNSSEC.  As part of   this activity, the use of DNSSEC in a non-major provider zone is   being implemented and studied.2.6 NIST   NIST is collecting performance information regarding DNSSEC.  One of   the fears in adopting DNSSEC is the workload it adds to existing DNS   machine workload.  The hopes of this effort is to quantify the fear,   to see if it is real or imagined.   If time permits, there may be an effort to implement a zone integrity   checking program (implemented in Java) that will look for missteps in   the use of DNSSEC.  Base code exists, but needs work (beyond the   current baseline).Lewis                        Informational                      [Page 4]

RFC 3130              DNSSEC Status Meeting Report             June 20012.7 DISA   The U.S. Defense Information Systems Agency is providing funds to   have DNSSEC implemented in BIND.  Of particular interest is making   sure that the DNSSEC specifications are correct, that BIND adheres to   the specifications, and that BIND is available on the operating   systems in use by the US Department of Defense.  DISA expects that   every line of code developed through this effort be made publicly   available as part of stock BIND releases.2.8 RIPE NCC   The RIPE NCC is looking at the impact of DNSSEC on IP-registries.   The RIPE NCC is planning to coordinate and assist in the deployment   of DNSSEC.  Because the RIPE NCC is the Regional Internet Registry   for Europe the focus will be on the deployment of DNSSEC on the   reverse map tree (in-addr.arpa for IPv4).2.9 ARIN   ARIN is investigating DNSSEC for use in signing its delegated zones   under in-addr.arpa.  It participated in a dnssec workshop following   NANOG 20 held in Washington, DC in October, 2000.  It also   participated in an ipv6-dnssec workshop that followed IETF 49 in San   Diego, California.  Additionally, ARIN has stood up a server   dedicated to testing various dns experimentation, including dnssec   and carrying out limited testing.2.10 Network Associates   NAI is pressing to get the tislabs.com zone running in accordance   with DNSSEC.  This is an example of a non-Internet service provider   (neither an IP transit, IP address allocation, nor a domain name   managing entity) making use of DNSSEC within the normal operations of   the Information Technology department.2.11 ip6.int. domain   The name servers authoritative for the ip6.int. domain are mostly   upgraded to be able to support CERT records and TSIG.  Once this is   fully accomplished and proposals are approved, TSIG and CERT records   will be used.  Further DNSSEC work is unknown.2.12 Topology Based Domain Search   Topology Based Domain Search (TBDS), is a DARPA funded activity   investigating how DNS may continue to run in disconnected parts of   the Internet.  Topics of interest (either covered by this project, orLewis                        Informational                      [Page 5]

RFC 3130              DNSSEC Status Meeting Report             June 2001   associated with the project) are the use of split keys, self-signed   zone (keys), and multiple signing algorithms.  A goal is the   establishment of signed infrastructure zones, facilitating the   creation of a distributed CA for activities like IPSEC and FreeSwan.3.0 Taxonomy of efforts and What is missing   The efforts being undertaken appear to cover a broad range of work   areas, from large domain registries to domain name consumers.  Work   has been progressing in the production of zones (signing, key   management), and is starting in the use (resolver) of DNSSEC secured   data.   From the discussion, there were no apparent areas lacking attention.   Additional input in some areas is needed however, particularly in   making use (applications and IT department) of DNSSEC.4.0 Questions facing DNSSEC   By the 49th IETF meeting, the most pressing question on DNSSEC is "is   it deployable?"  From just the emphasis placed on this question, the   meeting generated a list of questions and made sure that either the   answer was known, or work was being done to address the question.4.1 Is it deployable?When?   The usual answer to this has been "not now."  When is always off into   the future - "about a year."  To get to a deployable point, a series   of workshops have been held since the spring of 1999.   At this point, it is becoming clearer that longer term workshops are   needed.  In going through the motions of any workshop, the number of   issues raised that impact the protocol's specification is   diminishing, as well as implementation issues.  As such, one or two   day workshops have been helping less and less in reaching deployment.   What is needed is to run longer term test configurations, possibly   workshops that are help in conjunction with other events and that   assume continuity.  This will allow a better assessment of the issues   that involve the passage of time - expirations on key validations,   etc.   As was noted insection 1.1, and touched on insection 2, one   component of DNSSEC, TSIG, is more advanced that the others.  Use of   TSIG to protect zone transfers is already matured to the "really good   idea to do stage" even if other elements of DNSSEC are not.  Using   TSIG to protect traffic between local resolver and their "default"   recursive name server still needs more work, however.Lewis                        Informational                      [Page 6]

RFC 3130              DNSSEC Status Meeting Report             June 20014.2 Does DNSSEC work?Is it the right approach?   Currently there is a lot of effort into making the specification as   proposed work.  There is some effort in assessing the specification   at this point, particularly the value of the NXT records and possible   replacements of it.   There seems little question on value of the KEY and SIG records.   There is some research still needed on KEY validation across zone   boundaries.  Such work is at least scheduled.4.3 How will client software make use of DNSSEC?   There are a number of efforts to take existing applications and have   them make direct use of DNSSEC to carry out their functions.  One   such example is secure shell.   When or whether DNSSEC will be understood in the (using POSIX-like   terms) operating systems "gethostbyname" and similar routines has not   been addressed.4.4 What are the remaining issues?   There are still a few protocol issues.  The NXT resource record is   designed to provide a means to authentically deny data exists.  The   problem is that the solution proposed may be worse than the problem,   in the eyes of some.  There is an alternative proposal, the NO   resource record, under consideration in the DNSEXT working group.  At   the present time, the DNSEXT working is considering the following   question: Is there a need to authentically deny existence of data, if   so, which is better, NXT (being incumbent) or NO?   Another less defined issue is the mechanism for parent validation of   children signatures.  Although the protocol elements of this are   becoming settled, the operational considerations are not, as   evidenced by work mentioned insection 2.  DNSSEC interactions have   also been referenced in discussions over a standard registry-   registrar protocol.5.0 Progressing to Draft Standard   The IETF goal for DNSSEC is to progress the documents through the   standards track [RFC 2026].  Currently,RFC 2535 is the second   iteration at the Proposed standard level.  There is a need to cycle   through Proposed once more.  Following this, the next goal is Draft.Lewis                        Informational                      [Page 7]

RFC 3130              DNSSEC Status Meeting Report             June 2001   To pass to the Draft Standard level, two main requirements must be   met.  There must be two or more interoperable implementations.  There   must also be sufficient successful operational experience.5.1 Revision ofRFC 2535 via DNSEXT   DNSEXT will soon begin a rewrite of theRFC 2535 specification (and   its support documents), rolling in updates and clarifications based   upon implementation and testing experience.5.2 Operations document(s) via DNSOP   DNSOP will continue to be the forum for operations documents based   upon DNSSEC activity.  There is a need for the community to provide   more documents to this group.5.3 Interoperability   Demonstrating interoperability of DNSSEC, meaning the interaction of   two different implementations when performing DNSSEC work, poses an   issue because, to date, only BIND is seriously being fitted with   DNSSEC.  There are other partial implementations of DNSSEC   functionality, so the potential for partial interoperability   demonstrations may exist.   During the meeting, it was realized that given goals stated, a second   DNSSEC implementation is needed in 18 months.  Various folks in the   room mentioned that they would begin see what could be done about   this.6.0 Acknowledgements   The following people attended the meeting and/or provided text for   this report (in no particular order): Mark Kosters (Network   Solutions), Patrik Faltstrom (Cisco), Ted Lindgreen and Miek Gieben   (NLnet Labs), Jaap Akerhuis (SIDN), Olaf Kolkmann (RIPE NCC), Bill   Manning and Dan Massey (ISI), Martin Fredriksson, Hakan Olsson and   Jakob Schlyter (Carlstedt Research & Technology), Doug Montgomery and   Scott Rose (NIST), Johan Ihren and Lars-Johan Liman (Autonomica),   Brian Wellington (Nominum), Kevin Meynell (CENTR), Ed Lewis and   Olafur Gudmundsson (NAI Labs).7.0 IANA Considerations   This document does not involve assigned numbers in any way.Lewis                        Informational                      [Page 8]

RFC 3130              DNSSEC Status Meeting Report             June 20018.0 Security Considerations   This document, although a discussion of security enhancements to the   DNS, does not itself impact security.  Where security issues arise,   they will be discussed in the Security Considerations of the   appropriate document.9.0 References   The text of any RFC may be retrieved by a web browser by requesting   the URL:ftp://ftp.isi.edu/in-notes/rfc<wxyz>.txt, where "wxyz" is   the number of the RFC.   [RFC 2026] Bradner, S., "The Internet Standards Process -- Revision              3",BCP 9,RFC 2026, October 1996.   [RFC 2181] Elz, R. and R. Bush, "Clarifications to the DNS              Specification", July 1997.   [RFC 2535] Eastlake, D., "Domain Name System Security Extensions",              March 1999.   [RFC 2538] Eastlake, D. and O. Gudmundsson, "Storing Certificates in              the Domain Name System", March 1999.   [RFC 2845] Vixie, P., Gudmundsson, O., Eastlake, D. and B.              Wellington, "Secret Key Transaction Authentication for DNS              (TSIG)", May 2000.   [RFC 3007] Wellington, B., "Secure Domain Name System Dynamic              Update", November 2000.   [RFC 3008] Wellington, B., "Domain Name System Security Signing              Authority", November 2000.10.0 Editor's Address   Edward Lewis   3060 Washington Rd (Rte 97)   Glenwood, MD 21738   Phone: +1(443)259-2352   EMail: lewis@tislabs.comLewis                        Informational                      [Page 9]

RFC 3130              DNSSEC Status Meeting Report             June 200111.0 Full Copyright Statement   Copyright (C) The Internet Society (2001).  All Rights Reserved.   This document and translations of it may be copied and furnished to   others, and derivative works that comment on or otherwise explain it   or assist in its implementation may be prepared, copied, published   and distributed, in whole or in part, without restriction of any   kind, provided that the above copyright notice and this paragraph are   included on all such copies and derivative works.  However, this   document itself may not be modified in any way, such as by removing   the copyright notice or references to the Internet Society or other   Internet organizations, except as needed for the purpose of   developing Internet standards in which case the procedures for   copyrights defined in the Internet Standards process must be   followed, or as required to translate it into languages other than   English.   The limited permissions granted above are perpetual and will not be   revoked by the Internet Society or its successors or assigns.   This document and the information contained herein is provided on an   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING   TASK FORCE DISCLAIMS 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.Acknowledgement   Funding for the RFC Editor function is currently provided by the   Internet Society.Lewis                        Informational                     [Page 10]