From: http://tools.ietf.org/id/draft-daboo-carddav-directory-gateway-00.txt Title: CardDAV Directory Gateway Extension Reference: IETF Network Working Group, Internet Draft 'draft-daboo-carddav-directory-gateway-00' Date: February 26, 2010 Data Tracker: https://datatracker.ietf.org/doc/draft-daboo-carddav-directory-gateway/ Tracker Listing: http://ietfreport.isoc.org/idref/draft-daboo-carddav-directory-gateway/ Tools: http://tools.ietf.org/html/draft-daboo-carddav-directory-gateway-00 (HTML) Announced: http://www.ietf.org/mail-archive/web/i-d-announce/current/msg29716.html http://www.ietf.org/mail-archive/web/vcarddav/current/threads.html#01357 See also: IETF vCard and CardDAV (VCARDDAV) Working Group Charter http://www.ietf.org/html.charters/vcarddav-charter.html IETF vCard and CardDAV Working Group Status Pages http://tools.ietf.org/wg/vcarddav/ IETF vCard and CardDAV Wiki http://www.vcarddav.org/wiki VCARDDAV: vCard and CardDAV Engineering Discussion List https://www1.ietf.org/mailman/listinfo/vcarddav IETF Applications Area http://www.ietf.org/html.charters/wg-dir.html#Applications%20Area The IETF Applications Area Web Site http://www.apps.ietf.org/ XEP-0054: vcard-temp (vCard-XML format used within the Jabber community as of 2008-07-16) http://xmpp.org/extensions/xep-0054.html vCard XML Schema http://tools.ietf.org/html/draft-perreault-vcarddav-vcardxml-00 Microformats: Suggestions for vCard Revision http://microformats.org/wiki/vcard-suggestions ============================================================================== Network Working Group C. Daboo Internet-Draft Apple Inc. Intended status: Standards Track February 26, 2010 Expires: August 30, 2010 CardDAV Directory Gateway Extension draft-daboo-carddav-directory-gateway-00 Abstract This document defines and extension to the vCard Extensions to WebDAV (CardDAV) protocol that allows a server to expose a directory as a read-only address book collection. Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and 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 August 30, 2010. Copyright Notice Copyright (c) 2010 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 Daboo Expires August 30, 2010 [Page 1] Internet-Draft CardDAV Directory Gateway Extension February 2010 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 BSD License. Table of Contents 1. Introduction and Overview . . . . . . . . . . . . . . . . . . . 3 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. CARDDAV:directory-gateway Property . . . . . . . . . . . . . . 4 4. Client Guidelines . . . . . . . . . . . . . . . . . . . . . . . 4 5. Server Guidelines . . . . . . . . . . . . . . . . . . . . . . . 5 6. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 7. IANA Consideration . . . . . . . . . . . . . . . . . . . . . . 6 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 6 9. Normative References . . . . . . . . . . . . . . . . . . . . . 6 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 7 Daboo Expires August 30, 2010 [Page 2] Internet-Draft CardDAV Directory Gateway Extension February 2010 1. Introduction and Overview The CardDAV [I-D.ietf-vcarddav-carddav] protocol defines a standard way of accessing, managing, and sharing contact information based on the vCard [RFC2426] format. Often, in an enterprise or service provider environment, a directory of all users hosted on the server (or elsewhere) is available. It would be convenient for CardDAV clients if this directory were exposed as a "global" address book on the CardDAV server so it could be searched just as personal address books are. This specification defines a "directory gateway" feature extension to CardDAV to enable this. This specification adds one new WebDAV property to principal resources that contains the URI to the directory gateway address book collection resource. Note that this feature is in no way intended to replace full directory access - it is meant to simply provide a convenient way for CardDAV clients to query contact-related attributes in directory records. 2. Conventions 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]. The term "protected" is used in the Conformance field of property definitions as defined in Section 15 of [RFC4918]. This document uses XML DTD fragments ([W3C.REC-xml-20081126], Section 3.2) as a purely notational convention. WebDAV request and response bodies cannot be validated by a DTD due to the specific extensibility rules defined in Section 17 of [RFC4918] and due to the fact that all XML elements defined by this specification use the XML namespace name "DAV:". In particular: 1. element names use the "DAV:" namespace, 2. element ordering is irrelevant unless explicitly stated, 3. extension elements (elements not already defined as valid child elements) may be added anywhere, except when explicitly stated otherwise, 4. extension attributes (attributes not already defined as valid for this element) may be added anywhere, except when explicitly Daboo Expires August 30, 2010 [Page 3] Internet-Draft CardDAV Directory Gateway Extension February 2010 stated otherwise. When XML element types in the namespaces "DAV:" and "urn:ietf:params:xml:ns:carddav" are referenced in this document outside of the context of an XML fragment, the strings "DAV:" and "CARDDAV:" will be prefixed to the element types, respectively. 3. CARDDAV:directory-gateway Property Name: directory-gateway Namespace: urn:ietf:params:xml:ns:carddav Purpose: Identifies the URL of a CardDAV address book collection acting as the directory gateway for the server. Protected: MUST be protected. allprop behavior: SHOULD NOT be returned by a PROPFIND DAV:allprop request. Description: The CARDDAV:directory-gateway identifies an address book collection resource that is the directory gateway address book for the server. Definition: Example: /directory 4. Client Guidelines Clients wishing to make use of the directory gateway address book can request the CARDDAV:directory-gateway property when examining other properties on the principal resource for the user. If the property is not present, then the directory gateway feature is not supported by the server at that time. Since the directory being exposed via the directory gateway address book collection could be large, clients SHOULD use the feature to Daboo Expires August 30, 2010 [Page 4] Internet-Draft CardDAV Directory Gateway Extension February 2010 limit the number of results returned in an CARDDAV:addressbook-query REPORT as defined in Section 8.6.1 of [I-D.ietf-vcarddav-carddav]. Clients MUST treat the directory gateway address book collection as a read-only collection, so HTTP methods that modify resource data or properties in the address book collection MUST NOT be used. Clients SHOULD NOT attempt to cache the entire contents of the directory gateway address book collection resource by retrieving all resources. Instead, CARDDAV:addressbook-query REPORTs are used to search for specific address book object resources. 5. Server Guidelines Servers wishing to expose a directory gateway as an address book collection MUST include the CARDDAV:directory-gateway property on all principal resources of users expected to use the feature. Since the directory being exposed via the directory gateway address book collection could be large, servers SHOULD use the feature to truncate the number of results returned in an CARDDAV:addressbook- query REPORT as defined in Section 8.6.2 of [I-D.ietf-vcarddav-carddav]. Since the directory being exposed via the directory gateway address book collection could be large, servers SHOULD use the feature to truncate the number of results returned in an CARDDAV:addressbook- query REPORT as defined in Section 8.6.2 of [I-D.ietf-vcarddav-carddav]. In addition, servers SHOULD disallow requests that effectively enumerate the collection contents (e.g., PROPFIND Depth:1, trivial CARDDAV:addressbook-query, DAV:sync- collection REPORT). Servers need to expose the directory information as a set of address book object resources in the directory gateway address book collection resource. To do that, a mapping between the directory record format and the vCard data has to be applied. In general, only directory record attributes that have a direct equivalent in vCard SHOULD be mapped. It is up to individual implementations to determine which attributes to map. But in all cases servers MUST generate valid vCard data as returned to the client. 6. Security Considerations Servers MUST ensure that client requests against the directory gateway address book collection cannot use excessive resources (CPU, Daboo Expires August 30, 2010 [Page 5] Internet-Draft CardDAV Directory Gateway Extension February 2010 memory, network bandwidth etc), given that the directory could be large. Servers MUST take care not to expose sensitive directory record attributes in the vCard data via the directory gateway address book. In general only those properties that have direct correspondence in vCard SHOULD be exposed. Servers need to determine whether it is appropriate for the directory information to be available via CardDAV to unauthenticated users. If not, servers MUST ensure that unauthenticated users do not have access to the directory gateway address book object resource and its contents. If unauthenticated access is allowed, servers MAY choose to limit the set of vCard properties that are searchable or returned in the address book object resources when unauthenticated requests are made. 7. IANA Consideration This document does not require any actions on the part of IANA. 8. Acknowledgments 9. Normative References [I-D.ietf-vcarddav-carddav] Daboo, C., "vCard Extensions to WebDAV (CardDAV)", draft-ietf-vcarddav-carddav-10 (work in progress), November 2009. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2426] Dawson, F. and T. Howes, "vCard MIME Directory Profile", RFC 2426, September 1998. [RFC4918] Dusseault, L., "HTTP Extensions for Web Distributed Authoring and Versioning (WebDAV)", RFC 4918, June 2007. [W3C.REC-xml-20081126] Paoli, J., Yergeau, F., Bray, T., Sperberg-McQueen, C., and E. Maler, "Extensible Markup Language (XML) 1.0 (Fifth Edition)", World Wide Web Consortium Recommendation REC- xml-20081126, November 2008, . Daboo Expires August 30, 2010 [Page 6] Internet-Draft CardDAV Directory Gateway Extension February 2010 Author's Address Cyrus Daboo Apple Inc. 1 Infinite Loop Cupertino, CA 95014 USA Email: cyrus@daboo.name URI: http://www.apple.com/ Daboo Expires August 30, 2010 [Page 7]