forked from friendica/friendica-addons
282 lines
8.6 KiB
Plaintext
282 lines
8.6 KiB
Plaintext
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Network Working Group W. Sanchez
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Request for Comments: 5397 C. Daboo
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Category: Standards Track Apple Inc.
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December 2008
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WebDAV Current Principal Extension
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Status of This Memo
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This document specifies an Internet standards track protocol for the
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Internet community, and requests discussion and suggestions for
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improvements. Please refer to the current edition of the "Internet
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Official Protocol Standards" (STD 1) for the standardization state
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and status of this protocol. Distribution of this memo is unlimited.
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Copyright Notice
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Copyright (c) 2008 IETF Trust and the persons identified as the
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document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
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Provisions Relating to IETF Documents
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(http://trustee.ietf.org/license-info) in effect on the date of
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publication of this document. Please review these documents
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carefully, as they describe your rights and restrictions with respect
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to this document.
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Abstract
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This specification defines a new WebDAV property that allows clients
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to quickly determine the principal corresponding to the current
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authenticated user.
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Table of Contents
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1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
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2. Conventions Used in This Document . . . . . . . . . . . . . . . 2
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3. DAV:current-user-principal . . . . . . . . . . . . . . . . . . 3
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4. Security Considerations . . . . . . . . . . . . . . . . . . . . 4
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5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 4
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6. Normative References . . . . . . . . . . . . . . . . . . . . . 4
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Sanchez & Daboo Standards Track [Page 1]
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RFC 5397 WebDAV Current Principal December 2008
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1. Introduction
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WebDAV [RFC4918] is an extension to HTTP [RFC2616] to support
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improved document authoring capabilities. The WebDAV Access Control
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Protocol ("WebDAV ACL") [RFC3744] extension adds access control
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capabilities to WebDAV. It introduces the concept of a "principal"
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resource, which is used to represent information about authenticated
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entities on the system.
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Some clients have a need to determine which [RFC3744] principal a
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server is associating with the currently authenticated HTTP user.
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While [RFC3744] defines a DAV:current-user-privilege-set property for
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retrieving the privileges granted to that principal, there is no
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recommended way to identify the principal in question, which is
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necessary to perform other useful operations. For example, a client
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may wish to determine which groups the current user is a member of,
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or modify a property of the principal resource associated with the
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current user.
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The DAV:principal-match REPORT provides some useful functionality,
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but there are common situations where the results from that query can
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be ambiguous. For example, not only is an individual user principal
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returned, but also every group principal that the user is a member
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of, and there is no clear way to distinguish which is which.
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This specification proposes an extension to WebDAV ACL that adds a
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DAV:current-user-principal property to resources under access control
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on the server. This property provides a URL to a principal resource
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corresponding to the currently authenticated user. This allows a
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client to "bootstrap" itself by performing additional queries on the
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principal resource to obtain additional information from that
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resource, which is the purpose of this extension. Note that while it
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is possible for multiple URLs to refer to the same principal
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resource, or for multiple principal resources to correspond to a
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single principal, this specification only allows for a single http(s)
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URL in the DAV:current-user-principal property. If a client wishes
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to obtain alternate URLs for the principal, it can query the
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principal resource for this information; it is not the purpose of
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this extension to provide a complete list of such URLs, but simply to
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provide a means to locate a resource which contains that (and other)
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information.
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2. Conventions Used in This Document
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The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
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"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
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document are to be interpreted as described in [RFC2119].
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Sanchez & Daboo Standards Track [Page 2]
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RFC 5397 WebDAV Current Principal December 2008
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When XML element types in the namespace "DAV:" are referenced in this
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document outside of the context of an XML fragment, the string "DAV:"
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will be prefixed to the element type names.
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Processing of XML by clients and servers MUST follow the rules
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defined in Section 17 of WebDAV [RFC4918].
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Some of the declarations refer to XML elements defined by WebDAV
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[RFC4918].
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3. DAV:current-user-principal
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Name: current-user-principal
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Namespace: DAV:
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Purpose: Indicates a URL for the currently authenticated user's
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principal resource on the server.
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Value: A single DAV:href or DAV:unauthenticated element.
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Protected: This property is computed on a per-request basis, and
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therefore is protected.
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Description: The DAV:current-user-principal property contains either
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a DAV:href or DAV:unauthenticated XML element. The DAV:href
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element contains a URL to a principal resource corresponding to
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the currently authenticated user. That URL MUST be one of the
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URLs in the DAV:principal-URL or DAV:alternate-URI-set properties
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defined on the principal resource and MUST be an http(s) scheme
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URL. When authentication has not been done or has failed, this
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property MUST contain the DAV:unauthenticated pseudo-principal.
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In some cases, there may be multiple principal resources
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corresponding to the same authenticated principal. In that case,
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the server is free to choose any one of the principal resource
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URIs for the value of the DAV:current-user-principal property.
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However, servers SHOULD be consistent and use the same principal
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resource URI for each authenticated principal.
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COPY/MOVE behavior: This property is computed on a per-request
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basis, and is thus never copied or moved.
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Definition:
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<!ELEMENT current-user-principal (unauthenticated | href)>
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<!-- href value: a URL to a principal resource -->
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Sanchez & Daboo Standards Track [Page 3]
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RFC 5397 WebDAV Current Principal December 2008
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Example:
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<D:current-user-principal xmlns:D="DAV:">
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<D:href>/principals/users/cdaboo</D:href>
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</D:current-user-principal>
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4. Security Considerations
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This specification does not introduce any additional security issues
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beyond those defined for HTTP [RFC2616], WebDAV [RFC4918], and WebDAV
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ACL [RFC3744].
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5. Acknowledgments
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This specification is based on discussions that took place within the
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Calendaring and Scheduling Consortium's CalDAV Technical Committee.
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The authors thank the participants of that group for their input.
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The authors thank Julian Reschke for his valuable input via the
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WebDAV working group mailing list.
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6. Normative References
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[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
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Requirement Levels", BCP 14, RFC 2119, March 1997.
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[RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
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Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
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Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
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[RFC3744] Clemm, G., Reschke, J., Sedlar, E., and J. Whitehead, "Web
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Distributed Authoring and Versioning (WebDAV)
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Access Control Protocol", RFC 3744, May 2004.
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[RFC4918] Dusseault, L., "HTTP Extensions for Web Distributed
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Authoring and Versioning (WebDAV)", RFC 4918, June 2007.
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Authors' Addresses
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Wilfredo Sanchez
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Apple Inc.
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1 Infinite Loop
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Cupertino, CA 95014
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USA
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EMail: wsanchez@wsanchez.net
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URI: http://www.apple.com/
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Sanchez & Daboo Standards Track [Page 4]
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RFC 5397 WebDAV Current Principal December 2008
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Cyrus Daboo
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Apple Inc.
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1 Infinite Loop
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Cupertino, CA 95014
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USA
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EMail: cyrus@daboo.name
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URI: http://www.apple.com/
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Sanchez & Daboo Standards Track [Page 5]
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