appsawg L. Goix Internet-Draft Telecom Italia Intended status: Standards Track K. Li Expires: January 12, 2013 Huawei Technologies July 11, 2012 ENUM Service Registration for Social Networking (SN) Services draft-goix-appsawg-enum-sn-service-02 Abstract This document registers a Telephone Number Mapping (ENUM) service for Social Networking (SN). Specifically, this document focuses on provisioning 'acct:' URIs (Uniform Resource Identifiers) in ENUM. 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 January 12, 2013. Copyright Notice Copyright (c) 2012 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. Goix & Li Expires January 12, 2013 [Page 1] Internet-Draft Enum Service SN registration July 2012 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Justification . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. IANA Registration . . . . . . . . . . . . . . . . . . . . . . 3 3. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. DNS Considerations . . . . . . . . . . . . . . . . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . 5 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6 8. Change log (to be deleted before publication) . . . . . . . . 6 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 9.1. Normative References . . . . . . . . . . . . . . . . . . . . 7 9.2. Informative References . . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 8 Goix & Li Expires January 12, 2013 [Page 2] Internet-Draft Enum Service SN registration July 2012 1. Introduction ENUM (E.164 Number Mapping, [RFC6116]) is a system that uses DNS (Domain Name Service, [RFC1034]) to translate telephone numbers, such as '+44 01632 960123', into URIs (Uniform Resource Identifiers, [RFC3986], such as 'acct:user@example.com'. ENUM exists primarily to facilitate the interconnection of systems that rely on telephone numbers with those that use URIs to identify resources. Social Networking (SN) services allow users to post and retrieve activities (e.g. status updates or media uploads) and related replies. [I-D.saintandre-acct-uri] is proposing a generic URI to identify an SN service account for a particular resource: the 'acct:' URI scheme. This document registers an enumservice for advertising account information associated with an E.164 number. 1.1. Justification The requirement to map an SN account with an E.164 number is from the Open Mobile Alliance (OMA) Social Network Web Enabler Release [OMA-SNeW-ER]. In Mobile networks, users are traditionally identified through a Mobile Subscriber ISDN (MSISDN) number. In order to provide SN functionality to mobile subscribers identified by their MSISDN, a mapping is needed to identify a corresponding SN account and provider. 1.2. 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 [RFC2119]. 2. IANA Registration As defined in [RFC6117], the following is a template covering information needed for the registration of the enumservice specified in this document: Goix & Li Expires January 12, 2013 [Page 3] Internet-Draft Enum Service SN registration July 2012 Application-Based, Common sn acct This Enumservice indicates that the resource can be addressed by the associated URI using SN protocols, including to discover additional information. See . COMMON This document. Laurent-Walter Goix Telecom Italia mailto:laurentwalter.goix@telecomitalia.it 2012-07-10 3. Examples The following is an example of the use of the enumservice registered by this document in a NAPTR resource record for phone number +44 01632 960123. $ORIGIN 3.2.1.0.6.9.2.3.6.1.0.4.4.e164.arpa. IN NAPTR 10 100 "u" "E2U+sn" "!^.*$!acct:john.doe@example.com!" . Goix & Li Expires January 12, 2013 [Page 4] Internet-Draft Enum Service SN registration July 2012 4. DNS Considerations If no "E2U+sn" NAPTR record exist for the requested number, the resolution process over issuing ENUM queries may be recursively performed over E.164 numbers identified by other NAPTR records for the requested number pointing to "tel" URIs [RFC3966]. Whilst this process is useful to support, amongst others, number portability as per [RFC4769], Section 4, this may also create potential loops in this resolution process. As such ENUM clients performing such ENUM queries over "tel" URIs to identify "acct" URIs SHOULD understand the "enumdi" indicator defined in [RFC4759]. In particular, if the result of the query does not include "E2U+sn" NAPTR records, and includes a NAPTR resource record containing a "tel" URI that has the same E.164 number, or a "tel" URI with the "enumdi" parameter set, that client SHOULD NOT perform subsequent ENUM queries over such numbers and SHOULD consider that the original requested number cannot be mapped. Furthermore the client MAY stop performing subsequent ENUM queries after the fifth recursive query as suggested in [RFC6116] section 5.2.1. 5. Security Considerations DNS, as used by ENUM, is a global, distributed database. Should implementers of this specification use e164.arpa or any other publicly available domain as the tree for maintaining PSTN Enumservice data, this information would be visible to anyone anonymously. As noted earlier, carriers, service providers, and other users may choose not to publish such information in the public e164.arpa tree. They may instead simply publish this in an internal ENUM infrastructure that is only able to be queried by trusted elements of their network, thus limiting threats. Per se, this enumservice does not introduce specific security considerations beyond [RFC6116], section 7. However, it has to be acknowledged that the proposed Enumservice could lead to the discovery or disclosure of Personally Identifiable Information (PII) if used in combination with the WebFinger protocol. Please see [I-D.ietf-appsawg-webfinger], section 10 for additional information regarding WebFinger security to avoid unwanted disclosure of information. Similar security concerns are associated with potential attacks against an underlying Social Networking system. Unlike a traditional Goix & Li Expires January 12, 2013 [Page 5] Internet-Draft Enum Service SN registration July 2012 telephone number, and as per the indirect nature of SN communication (typically through an intermediary network element), the resource identified by an 'acct:' URI may not be subject to direct communication with other peers. However (e.g. in case of private message exchange) it may require that peers provide cryptographic credentials for authentication and authorization before messages are exchanged. For this reason, SN protocols should have a number of security requirements that call for authentication, integrity and confidentiality properties, and similar measures to prevent such attacks. 6. IANA Considerations This document requests the IANA registration of the Enumservice with Type "sn" according to the definitions in this document, [RFC6116] and [RFC6117]. Details of the registration are given in Section 2. 7. Acknowledgements The authors would like to thank Gonzalo Salgueiro, Paul Jones, Lawrence Conroy, and Enrico Marocco for their valuable feedback to improve this document. 8. Change log (to be deleted before publication) -02 Draft * Updated references to acct: URI I-D and OMA specifications * Added changelog section -01 Draft * Made changes to example phone numbers * Updated security and DNS considerations * Fixed IANA registration template * Added acknowledgment section 9. References Goix & Li Expires January 12, 2013 [Page 6] Internet-Draft Enum Service SN registration July 2012 9.1. Normative References [I-D.ietf-appsawg-webfinger] Jones, P., Salgueiro, G., and J. Smarr, "WebFinger", draft-ietf-appsawg-webfinger-00 (work in progress), July 2012. [I-D.saintandre-acct-uri] Saint-Andre, P., "The 'acct' URI Scheme", draft-saintandre-acct-uri-01 (work in progress), July 2012. [RFC1034] Mockapetris, P., "Domain names - concepts and facilities", STD 13, RFC 1034, November 1987. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3966] Schulzrinne, H., "The tel URI for Telephone Numbers", RFC 3966, December 2004. [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, January 2005. [RFC4759] Stastny, R., Shockey, R., and L. Conroy, "The ENUM Dip Indicator Parameter for the "tel" URI", RFC 4759, December 2006. [RFC4769] Livingood, J. and R. Shockey, "IANA Registration for an Enumservice Containing Public Switched Telephone Network (PSTN) Signaling Information", RFC 4769, November 2006. [RFC6116] Bradner, S., Conroy, L., and K. Fujiwara, "The E.164 to Uniform Resource Identifiers (URI) Dynamic Delegation Discovery System (DDDS) Application (ENUM)", RFC 6116, March 2011. [RFC6117] Hoeneisen, B., Mayrhofer, A., and J. Livingood, "IANA Registration of Enumservices: Guide, Template, and IANA Considerations", RFC 6117, March 2011. 9.2. Informative References [OMA-SNeW-ER] Open Mobile Alliance, "Social Network Web Enabler", OMA- ER-SNeW-V1_0 20120702-D, July 2012. Goix & Li Expires January 12, 2013 [Page 7] Internet-Draft Enum Service SN registration July 2012 Authors' Addresses Laurent-Walter Goix Telecom Italia P.za Einaudi, 8 Milano 20124 Italy Email: laurentwalter.goix@telecomitalia.it Kepeng Li Huawei Technologies Huawei Base, Bantian, Longgang District Shenzhen, Guangdong 518129 P. R. China Phone: +86-755-28974289 Email: likepeng@huawei.com Goix & Li Expires January 12, 2013 [Page 8]