Network Working Group A. Mayrhofer Request for Comments: 4979 enum.at Category: Standards Track August 2007 IANA Registration for Enumservice 'XMPP' Status of This Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The IETF Trust (2007). Abstract This document requests IANA registration of an Enumservice for XMPP, the Extensible Messaging and Presence Protocol. This Enumservice specifically allows the use of 'xmpp' Uniform Resource Identifiers (URIs) in the context of E.164 Number Mapping (ENUM). Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Enumservice Registration - XMPP . . . . . . . . . . . . . . . . 2 4. XMPP IRI/URI Considerations for ENUM . . . . . . . . . . . . . 3 4.1. Authority Component . . . . . . . . . . . . . . . . . . . . 3 4.2. IRI-to-URI mapping . . . . . . . . . . . . . . . . . . . . 3 5. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 6. Security and Privacy Considerations . . . . . . . . . . . . . . 4 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 4 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 9.1. Normative References . . . . . . . . . . . . . . . . . . . 5 9.2. Informative References . . . . . . . . . . . . . . . . . . 5 Mayrhofer Standards Track [Page 1] RFC 4979 XMPP Enumservice August 2007 1. Introduction E.164 Number Mapping (ENUM) [1] uses the Domain Name System (DNS) [6] to refer from E.164 numbers [7] to Uniform Resource Identifiers (URIs) [3]. Specific services to be used with ENUM must be registered with IANA. Section 3 of RFC 3761 describes the process of such an Enumservice registration. The Extensible Messaging and Presence Protocol (XMPP) [9] provides means for streaming Extensible Markup Language (XML) [8] elements between endpoints in close to real time. The XMPP framework is mainly used to provide instant messaging, presence, and streaming media services. RFC 4622 [5] registers a Uniform Resource Identifier (URI) scheme for identifying an XMPP entity as a URI or as an Internationalized Resource Identifier (IRI) [4]. The Enumservice specified in this document allows the provisioning of such "xmpp" URIs (and the URI representations of "xmpp" IRIs) in ENUM. 2. Terminology 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 RFC 2119 [2]. 3. Enumservice Registration - XMPP The following template contains information required for the IANA registrations of the 'XMPP' Enumservice, according to Section 3 of RFC 3761: Enumservice Name: "XMPP" Enumservice Type: "xmpp" Enumservice Subtype: n/a URI Schemes: "xmpp" Functional Specification: This Enumservice indicates that the resource identified is an XMPP entity. Security Considerations: see Section 6 Mayrhofer Standards Track [Page 2] RFC 4979 XMPP Enumservice August 2007 Intended Usage: COMMON Author: Alexander Mayrhofer 4. XMPP IRI/URI Considerations for ENUM 4.1. Authority Component XMPP IRIs/URIs optionally contain an "Authority Component" (see Section 2.3 of RFC 4622). The presence of such an Authority Component in an IRI/URI signals the processing application to authenticate as the user indicated in the URI/IRI rather than using the preconfigured identity. In the context of this Enumservice, arbitrary clients may discover and use the XMPP URIs/IRIs associated to an E.164 number. Hence, in most cases, those clients will not be able to authenticate as requested in the Authority Component. Therefore, URIs/IRIs that result from processing an XMPP Enumservice record SHOULD NOT contain an Authority Component. 4.2. IRI-to-URI mapping While XMPP supports IRIs as well as 'plain' URIs, ENUM itself supports only the use of URIs for Enumservices. Therefore, XMPP IRIs MUST be mapped to URIs for use in an XMPP Enumservice record. The mapping MUST follow the procedures outlined in Section 3.1 of RFC 3987. 5. Example An example ENUM entry referencing to a XMPP URI could look like: $ORIGIN 6.9.4.0.6.9.4.5.1.1.4.4.e164.arpa. @ IN NAPTR ( 100 10 "u" "E2U+xmpp" "!^.*$!xmpp:some-user@example.com!" . ) Mayrhofer Standards Track [Page 3] RFC 4979 XMPP Enumservice August 2007 6. Security and Privacy Considerations General security considerations of the protocols on which this Enumservice registration is based are addressed in Sections 3.1.3 and 6 of RFC 3761 (ENUM) and Section 14 of RFC 3920 (XMPP). Since ENUM uses DNS -- a publicly available database -- any information contained in records provisioned in ENUM domains must be considered public as well. Even after revoking the DNS entry and removing the referred resource, copies of the information could still be available. Information published in ENUM records could reveal associations between E.164 numbers and their owners -- especially if IRIs/URIs contain personal identifiers or domain names for which ownership information can be obtained easily. However, it is important to note that the ENUM record itself does not need to contain any personal information. It just points to a location where access to personal information could be granted. ENUM records pointing to third-party resources can easily be provisioned on purpose by the ENUM domain owner -- so any assumption about the association between a number and an entity could therefore be completely bogus unless some kind of identity verification is in place. This verification is out of scope for this memo. 7. IANA Considerations This memo requests IANA to add a new "XMPP" Enumservice to the 'Enumservice Registrations' registry, according to the definitions in this document and RFC 3761 [1]. The required template is contained in Section 3. 8. Acknowledgements Some text from RFC 4622 was used in the Introduction of this document. Charles Clancy, Miguel Garcia, Andrew Newton, Jon Peterson, and Peter Saint-Andre provided extensive reviews and valuable feedback. Mayrhofer Standards Track [Page 4] RFC 4979 XMPP Enumservice August 2007 9. References 9.1. Normative References [1] Faltstrom, P. and M. Mealling, "The E.164 to Uniform Resource Identifiers (URI) Dynamic Delegation Discovery System (DDDS) Application (ENUM)", RFC 3761, April 2004. [2] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [3] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, January 2005. [4] Duerst, M. and M. Suignard, "Internationalized Resource Identifiers (IRIs)", RFC 3987, January 2005. [5] Saint-Andre, P., "Internationalized Resource Identifiers (IRIs) and Uniform Resource Identifiers (URIs) for the Extensible Messaging and Presence Protocol (XMPP)", RFC 4622, July 2006. 9.2. Informative References [6] Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, November 1987. [7] ITU-T, "The international public telecommunication numbering plan", Recommendation E.164 (02/05), Feb. 2005. [8] Maler, E., Paoli, J., Bray, T., Yergeau, F., and C. Sperberg- McQueen, "Extensible Markup Language (XML) 1.0 (Third Edition)", World Wide Web Consortium FirstEdition REC-xml-20040204, February 2004, . [9] Saint-Andre, P., Ed., "Extensible Messaging and Presence Protocol (XMPP): Core", RFC 3920, October 2004. Mayrhofer Standards Track [Page 5] RFC 4979 XMPP Enumservice August 2007 Author's Address Alexander Mayrhofer enum.at GmbH Karlsplatz 1/2/9 Wien A-1010 Austria Phone: +43 1 5056416 34 EMail: alexander.mayrhofer@enum.at URI: http://www.enum.at/ Mayrhofer Standards Track [Page 6] RFC 4979 XMPP Enumservice August 2007 Full Copyright Statement Copyright (C) The IETF Trust (2007). This document is subject to the rights, licenses and restrictions contained in BCP 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, THE IETF TRUST 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 in BCP 78 and BCP 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 at http://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 currently provided by the Internet Society. Mayrhofer Standards Track [Page 7]