Network Working Group W. Sanchez Internet-Draft C. Daboo Expires: November 30, 2008 Apple Inc. May 29, 2008 WebDAV Current Principal Extension draft-sanchez-webdav-current-principal-01 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 November 30, 2008. Abstract This specification defines a new WebDAV property that allows clients to quickly determine the principal corresponding to the current authenticated user. Sanchez & Daboo Expires November 30, 2008 [Page 1] Internet-Draft WebDAV Current Principal May 2008 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions Used in This Document . . . . . . . . . . . . . . . 3 3. DAV:current-user-principal . . . . . . . . . . . . . . . . . . 3 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 5 7. Normative References . . . . . . . . . . . . . . . . . . . . . 5 Appendix A. Change History (to be removed prior to publication as an RFC) . . . . . . . . . . . . . . . . 5 Sanchez & Daboo Expires November 30, 2008 [Page 2] Internet-Draft WebDAV Current Principal May 2008 1. Introduction WebDAV [RFC4918] is an extension to HTTP [RFC2616] to support improved document authoring capabilities. The WebDAV ACL [RFC3744] extension adds access control capabilities to WebDAV. It introduces the concept of a "principal resource" which is used to represent information about authenticated entities on the system. Some clients have a need to determine the [RFC3744] principal that a server is associating with the currently authenticated HTTP user. While [RFC3744] defines a DAV:current-user-privilege-set property for retrieving the privileges granted to that principal, there is no recommended way to do identify the principal in question, which is necessary to perform other useful operations. For example, a client may wish to determine which groups the current user is a member of, or modify a property of the principal resource associated with the current user. The DAV:principal-match REPORT provides some useful functionality, but there are common situations where the results from that query can be ambiguous (e.g. not only is an individual user principal returned, but also every group principal that the user is a member of, and there is no clear way to distinguish which is which). This specification proposes an extension to WebDAV ACL that adds a DAV:current-user-principal property to resources under access control on the server. This property specifies the principal resource corresponding to the currently authenticated user. 2. Conventions Used in This Document 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]. When XML element types in the namespace "DAV:" are referenced in this document outside of the context of an XML fragment, the string "DAV:" will be prefixed to the element type names. 3. DAV:current-user-principal Name: current-user-principal Namespace: DAV: Sanchez & Daboo Expires November 30, 2008 [Page 3] Internet-Draft WebDAV Current Principal May 2008 Purpose: Indicates a URL for the current authenticated user's principal resource on the server. Value: Single DAV:href element. Protected: This property is computed on a per-request basis, and therefore is protected. Description: The DAV:current-user-principal property contains either a DAV:href or DAV:unauthenticated XML element. The DAV:href element contains a URL to a principal resource corresponding to the currently authenticated user. That URL MUST be one of the URLs in the DAV:principal-URL or DAV:alternate-URI-set properties defined on the principal resource and MUST be an http(s) scheme URL. When authentication has not been done or has failed, this property MUST contain the DAV:unauthenticated pseudo-principal. In some cases there may be multiple principal resources corresponding to the same authenticated principal. In that case the server is free to choose any one of the principal resource URIs for the value of the DAV:current-user-principal property. However, servers SHOULD be consistent and use the same principal resource URI for each authenticated principal. COPY/MOVE behavior: This property is computed on a per-request basis, and is thus never copied or moved. Definition: Example: /principals/users/cdaboo 4. Security Considerations This specification does not introduce any additional security issues beyond those defined in HTTP [RFC2616], WebDAV [RFC4918] and WebDAV ACL [RFC3744]. 5. IANA Considerations This document does not require any actions on the part of IANA. Sanchez & Daboo Expires November 30, 2008 [Page 4] Internet-Draft WebDAV Current Principal May 2008 6. Acknowledgments This specification is based on discussions that took place within the Calendaring and Scheduling Consortium's CalDAV Technical Committee. The authors thank the participants of that group for their input. The authors thank Julian Reschke for his valuable input via the WebDAV working group mailing list. 7. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2616] 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. [RFC3744] Clemm, G., Reschke, J., Sedlar, E., and J. Whitehead, "Web Distributed Authoring and Versioning (WebDAV) Access Control Protocol", RFC 3744, May 2004. [RFC4918] Dusseault, L., "HTTP Extensions for Web Distributed Authoring and Versioning (WebDAV)", RFC 4918, June 2007. Appendix A. Change History (to be removed prior to publication as an RFC) Changes from -00: 1. Changed DAV:current-user-principal-resource to DAV:current-user- principal. 2. Correct DAV:current-user-principal element definition to use valid XML and not use the "DAV:" prefix for children. 3. Typo "DAV:unauthenticed" should be spelled "DAV:unauthenticated". Sanchez & Daboo Expires November 30, 2008 [Page 5] Internet-Draft WebDAV Current Principal May 2008 Authors' Addresses Wilfredo Sanchez Apple Inc. 1 Infinite Loop Cupertino, CA 95014 USA EMail: wsanchez@wsanchez.net URI: http://www.apple.com/ Cyrus Daboo Apple Inc. 1 Infinite Loop Cupertino, CA 95014 USA EMail: cyrus@daboo.name URI: http://www.apple.com/ Sanchez & Daboo Expires November 30, 2008 [Page 6] Internet-Draft WebDAV Current Principal May 2008 Full Copyright Statement Copyright (C) The IETF Trust (2008). 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. Sanchez & Daboo Expires November 30, 2008 [Page 7]