Network Working Group J. Miller Internet-Draft Individual Intended status: Informational P. Saint-Andre Expires: February 8, 2008 XMPP Standards Foundation F. Stutzman ClaimID August 7, 2007 MicroID draft-miller-microid-00 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on February 8, 2008. Copyright Notice Copyright (C) The IETF Trust (2007). Abstract This specification defines the semantics of MicroID, a lightweight identity technology that enables the creation of a portable identity token based on any two Uniform Resource Identifiers. Miller, et al. Expires February 8, 2008 [Page 1] Internet-Draft MicroID August 2007 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Architecture . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 5. Generation . . . . . . . . . . . . . . . . . . . . . . . . . . 5 6. Processing . . . . . . . . . . . . . . . . . . . . . . . . . . 7 7. Using Technologies . . . . . . . . . . . . . . . . . . . . . . 7 7.1. HTML Class Attribute . . . . . . . . . . . . . . . . . . . 7 7.2. HTML Meta Data . . . . . . . . . . . . . . . . . . . . . . 8 8. Internationalization Considerations . . . . . . . . . . . . . 8 9. Security Considerations . . . . . . . . . . . . . . . . . . . 8 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9 10.1. Normative References . . . . . . . . . . . . . . . . . . . 9 10.2. Informative References . . . . . . . . . . . . . . . . . . 9 Appendix A. Legacy Support . . . . . . . . . . . . . . . . . . . 10 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 10 Intellectual Property and Copyright Statements . . . . . . . . . . 11 Miller, et al. Expires February 8, 2008 [Page 2] Internet-Draft MicroID August 2007 1. Introduction MicroID is a lightweight identity technology that enables the creation of a portable identity token from any two Uniform Resource Identifiers ([URI]). Such identity tokens are desirable for several reasons: o They enable individuals to assert ownership over information published and reputation earned on the Internet in a granular manner, even if that information or reputation is hosted at a third-party service. o They enable service providers to "stamp" information and reputation based on a validated URI associated with an individual who uses the service. Note: The preferred discussion forum for this specification is the MicroID mailing list; subscription information is located at and the mailing list archives are located at . 2. Terminology The following terms describe the parties involved in the production and consumption of a MicroID: o Consumer -- Any party that reads a MicroID issued by an Issuer (in other identity systems, a Consumer is sometimes called a Relying Party). o Entity -- Either party identified by a URI or IRI that is used to construct a MicroID. o Individual -- An Entity that generates information or earns reputation. o Issuer -- The party that generates a MicroID. The Issuer can be a third party and need not be an Entity. o Service Provider -- An Entity that is responsible for hosting information or reputation; a Service Provider may or may not be an Issuer. The following keywords as used in this document are to be interpreted as described in [TERMS]: "MUST", "SHALL", "REQUIRED"; "MUST NOT", "SHALL NOT"; "SHOULD", "RECOMMENDED"; "SHOULD NOT", "NOT RECOMMENDED"; "MAY", "OPTIONAL". Miller, et al. Expires February 8, 2008 [Page 3] Internet-Draft MicroID August 2007 3. Architecture In general we assume that MicroID technology will be used by service providers to stamp information or reputation that is hosted by the service provider on behalf of individuals. In this architecture, the Service Provider is both the Issuer and one of the Entities, where the other Entity is an Individual. +--------+ | Entity | +--------+ | | registration | +-------------------+ | Service Provider | | (Entity + Issuer) | +-------------------+ | | issuance | MicroID However, a MicroID can also be issued by a trusted third party with which both a Service Provider and Individual have registered. In this architecture, the Service Provider is merely one of the Entities. +--------+ +------------------+ | Entity | | Service Provider | +--------+ +------------------+ | | | | +-----------------+ | | registration | +--------+ | Issuer | +--------+ | | issuance | MicroID Miller, et al. Expires February 8, 2008 [Page 4] Internet-Draft MicroID August 2007 4. Format The syntax for a MicroID is defined below using the Augmented Backus- Naur Form as defined in [ABNF]. microid = inputs ":" algo ":" hash inputs = scheme "+" scheme scheme = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." ) ; a URI scheme name (e.g., mailto) algo = ALPHA *( ALPHA / DIGIT ) ; the short name of a hashing ; algorithm (e.g., sha256), hash = *( ALPHA / DIGIT ) ; a hash of the URIs for both entities Note: See the Legacy Support (Appendix A) section of this document for information regarding the original MicroID format. 5. Generation A MicroID MUST be generated by an Issuer, not by an Individual. The Issuer MAY be the Service Provider that hosts the information about, content created by, or reputation earned by an Individual, or it MAY be a third party trusted by both the Individual and the Service Provider. An Issuer MUST NOT generate a MicroID until it has verified that the Individual or Service Provider has control over a given EntityURI. Methods for such verification are out of scope for this specification and may vary according to local service policies and the URI scheme in question. In general, the method for generating the hash is: hash = algo( algo(EntityURI) + algo(EntityURI) ) The "algo" MAY be any recognized hashing algorithm, such as those defined in [SHA]. Support for the sha1 and sha256 algorithms is REQUIRED for interoperability. The algorithm names shall be as registered with the IANA in the Hash Function Textual Names registry located at . The output MUST be in hexadecimal (not base64) format. The same Miller, et al. Expires February 8, 2008 [Page 5] Internet-Draft MicroID August 2007 algorithm MUST be used for all hashing functions when generating a given MicroID. The "EntityURI" MAY conform to any URI scheme, such as [HTTP], [MAILTO], [SIP], or [XMPP]. The first EntityURI MUST be that of the Individual and the second EntityURI MUST be that of the Service Provider. Any given EntityURI MAY have meaning above and beyond that encapsulated in the relevant URI scheme; for example, the HTTP URI for an Individual could be hosted by an OpenID service (see ). However, MicroID places no restrictions on the semantics of a given EntityURI. As an example, consider the following inputs, from which a MicroID is generated using the sha1 algorithm: o The first Entity is an Individual identified by an XMPP URI of "xmpp:stpeter@jabber.org". o The second Entity is a Service Provider identified by a HTTP URI of "https://www.xmpp.net/". The hash is generated as follows (note: the line break in the third example is included only for the sake of readability): sha1( sha1(xmpp:stpeter@jabber.org) + sha1(https://www.xmpp.net/) ) sha1( afa6353518f818af2f036da336c3097dedc00dee + 3115de01ebfa34a34314060b5f30038b0fa359f8 ) sha1( afa6353518f818af2f036da336c3097dedc00dee 3115de01ebfa34a34314060b5f30038b0fa359f8 ) 6196ea6709be2a4cbdf2bc0cfaeac491f2fb8921 Thus the issued MicroID is: xmpp+https:sha1:6196ea6709be2a4cbdf2bc0cfaeac491f2fb8921 Miller, et al. Expires February 8, 2008 [Page 6] Internet-Draft MicroID August 2007 6. Processing A processing application MAY use only the hash portion of the MicroID for comparison purposes. An implementation SHOULD be liberal in accepting MicroIDs that conform to the legacy format (see the Legacy Support (Appendix A) section of this document). 7. Using Technologies This specification does not limit the technologies that might make use of MicroIDs, and future versions of this specification might describe a wide range of such uses. Here we describe two such uses. Note: The scope of information (e.g., markup) covered by a MicroID depends on the nature of the using technology and must be defined separately by each using technology. 7.1. HTML Class Attribute One possible use is to include a MicroID in the [HTML] class attribute. The RECOMMENDED format is to prepend the MicroID itself with the string "microid-", as shown in the following example:

mycontent

In this usage, the scope of the MicroID is all information contained within the element that possesses the class attribute, whether that information is represented as attributes, character data, or child elements. However, any given child element MAY itself possess a class attribute specifying a MicroID that overrides the content claim asserted by the parent element. In all cases, the relevant claim is always that of the nearest containing element in the hierarchy. A MicroID can be used on its own to mark content as created by a certain Individual (e.g., a comment made on a web forum):

This is a great idea!

A MicroID can be also used in concert with other lightweight identity technologies such as the rel='me' value defined by XHTML Friends Network (XFN) as specified at : Miller, et al. Expires February 8, 2008 [Page 7] Internet-Draft MicroID August 2007

This is a great idea!

-- stpeter

7.2. HTML Meta Data Another possible use is in meta data about an [HTML] file (e.g., to signify that a given web page is created by, owned by, or about a given Individual). This is done by including a tag whose 'name' attribute is "microid" and whose 'content' attribute specifies the MicroID, as shown in the following example: In this usage, the scope of the MicroID is the page itself. However, the whole-page claim represented in the META tag can be overridden by claims represented in class attributes possessed by elements within the HTML body. A file MAY contain multiple META tags with a name of "microid" (e.g., to claim ownership by multiple authors or to represent multiple identities associated with the same individual). 8. Internationalization Considerations A MicroID SHOULD be constructed using two Uniform Resource Identifiers ([URI]) but one or both inputs MAY instead be an Internationalized Resource Identifier ([IRI]). 9. Security Considerations MicroID is a technology for identifying the ownership or authorship of information on the Internet. It is not a mechanism for authentication, authorization, security, or encryption. Use of MicroID technology results only in weak verification of identities. MicroID may be susceptible to [DNS] poisoning attacks unless [DNSSEC] is used, since most URIs depend on DNS. 10. References Miller, et al. Expires February 8, 2008 [Page 8] Internet-Draft MicroID August 2007 10.1. Normative References [ABNF] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 4234, October 2005. [SHA] National Institute of Standards and Technology, "Secure Hash Standard", FIPS PUB 180-2, August 2002, . [TERMS] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [URI] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, January 2005. 10.2. Informative References [DNS] Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, November 1987. [DNSSEC] Arends, R., Austein, R., Larson, M., Massey, D., and S. Rose, "DNS Security Introduction and Requirements", RFC 4033, March 2005. [HTML] Jacobs, I., Raggett, D., and A. Hors, "HTML 4.01 Specification", World Wide Web Consortium Recommendation REC-html401-19991224, December 1999, . [HTTP] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999. [IRI] Duerst, M. and M. Suignard, "Internationalized Resource Identifiers (IRIs)", RFC 3987, January 2005. [MAILTO] Hoffman, P., Masinter, L., and J. Zawinski, "The mailto URL scheme", RFC 2368, July 1998. [SIP] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP: Session Initiation Protocol", RFC 3261, June 2002. [XMPP] Saint-Andre, P., "Internationalized Resource Identifiers (IRIs) and Uniform Resource Identifiers (URIs) for the Extensible Messaging and Presence Protocol (XMPP)", Miller, et al. Expires February 8, 2008 [Page 9] Internet-Draft MicroID August 2007 RFC 4622, August 2006. Appendix A. Legacy Support MicroID originally assumed the use of sha1 as the hashing algorithm and did not specify the schemes of the EntityURI inputs, resulting in the following format: microid = hash hash = *( ALPHA / DIGIT ) ; a hash of the URIs for both entities For example, using the same inputs as shown in the body of this specification, the MicroID in legacy format would be: 6196ea6709be2a4cbdf2bc0cfaeac491f2fb8921 An implementation MUST generate MicroIDs in the format specified in the Format (Section 4) section of this document, but SHOULD process MicroIDs generated using the legacy format for the sake of backward compatibility. Authors' Addresses Jeremie Miller Individual Email: jeremie@jabber.org Peter Saint-Andre XMPP Standards Foundation Email: stpeter@jabber.org Fred Stutzman ClaimID Email: fred@metalab.unc.edu Miller, et al. Expires February 8, 2008 [Page 10] Internet-Draft MicroID 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. 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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. Acknowledgment Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA). Miller, et al. Expires February 8, 2008 [Page 11]