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Network Working Group                                           G. Clemm
Internet-Draft
Request for Comments: 3744                                           IBM
Expires: June 22, 2004
Category: Standards Track                                     J. Reschke
                                                              greenbytes
                                                               E. Sedlar
                                                      Oracle Corporation
                                                            J. Whitehead
                                                         U.C. Santa Cruz
                                                       December 23, 2003


                     WebDAV
                                                                May 2004


           Web Distributed Authoring and Versioning (WebDAV)
                        Access Control Protocol
                        draft-ietf-webdav-acl-13

Status of this Memo

   This document is specifies an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026.

   Internet-Drafts are working documents of Internet standards track protocol for the
   Internet Engineering
   Task Force (IETF), its areas, community, and its working groups. Note that other
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   Internet-Drafts are draft documents valid requests discussion and suggestions for a maximum
   improvements.  Please refer to the current edition of six months the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   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 status of current Internet-Drafts can be accessed at http://
   www.ietf.org/ietf/1id-abstracts.txt.

   The list this protocol.  Distribution of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on June 22, 2004. this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2003). (2004).  All Rights Reserved.

Abstract

   This document specifies a set of methods, headers, message bodies,
   properties, and reports that define Access Control extensions to the
   WebDAV Distributed Authoring Protocol.  This protocol permits a
   client to read and modify access control lists that instruct a server
   whether to allow or deny operations upon a resource (such as
   HyperText Transfer Protocol (HTTP) method invocations) by a given
   principal.  A lightweight representation of principals as Web



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   resources supports integration of a wide range of user management
   repositories.  Search operations allow discovery and manipulation of
   principals using human names.

   This document is a product of the Web Distributed Authoring and
   Versioning (WebDAV) working group of the Internet Engineering Task
   Force. Comments on this draft are welcomed, and should be addressed
   to the acl@webdav.org [1] mailing list. Other related documents can
   be found at [2], and [3].













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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . .  5
   1.1   Terms  . .  4
       1.1.  Terms. . . . . . . . . . . . . . . . . . . . . . . . . .  7
   1.2  6
       1.2.  Notational Conventions . . . . . . . . . . . . . . . . . . .  8
   2.  Principals . . . . . . . . . . . . . . . . . . . . . . . . . .  8
   3.  Privileges . . . . . . . . . . . . . . . . . . . . . . . . .  9
   3.1 .  8
       3.1.  DAV:read Privilege . . . . . . . . . . . . . . . . . . . . . 10
   3.2
       3.2.  DAV:write Privilege Privilege. . . . . . . . . . . . . . . . . . . . . 11
   3.3 10
       3.3.  DAV:write-properties Privilege . . . . . . . . . . . . . . . 11
   3.4 10
       3.4.  DAV:write-content Privilege  . . Privilege. . . . . . . . . . . . . . . 11
   3.5
       3.5.  DAV:unlock Privilege . . . . . . . . . . . . . . . . . . . . 12
   3.6 11
       3.6.  DAV:read-acl Privilege . . . . . . . . . . . . . . . . . . . 12
   3.7 11
       3.7.  DAV:read-current-user-privilege-set Privilege  . . Privilege. . . . . . 12
   3.8
       3.8.  DAV:write-acl Privilege  . Privilege. . . . . . . . . . . . . . . . . . 13
   3.9 12
       3.9.  DAV:bind Privilege . . . . . . . . . . . . . . . . . . . . . 13
   3.10 12
       3.10. DAV:unbind Privilege . . . . . . . . . . . . . . . . . . . . 13
   3.11 12
       3.11. DAV:all Privilege  . . Privilege. . . . . . . . . . . . . . . . . . . . 13
   3.12
       3.12. Aggregation of Predefined Privileges . . . . . . . . . . . . 13
   4.  Principal Properties . . . . . . . . . . . . . . . . . . . . 14
   4.1   DAV:alternate-URI-set  . . 13
       4.1.  DAV:alternate-URI-set. . . . . . . . . . . . . . . . . . 14
   4.2   DAV:principal-URL  .
       4.2.  DAV:principal-URL. . . . . . . . . . . . . . . . . . . . . 15
   4.3 14
       4.3.  DAV:group-member-set . . . . . . . . . . . . . . . . . . . . 15
   4.4 14
       4.4.  DAV:group-membership . . . . . . . . . . . . . . . . . . . . 15 14
   5.  Access Control Properties Properties. . . . . . . . . . . . . . . . . . 15
   5.1   DAV:owner  . . 15
       5.1.  DAV:owner. . . . . . . . . . . . . . . . . . . . . . . . 16
   5.1.1 15
             5.1.1. Example: Retrieving DAV:owner . . . . . . . . . . . . . . . 16
   5.1.2 15
             5.1.2. Example: An Attempt to Set DAV:owner DAV:owner. . . . . . . . . . . . . 17
   5.2   DAV:group  . . 16
       5.2.  DAV:group. . . . . . . . . . . . . . . . . . . . . . . . 18
   5.3   DAV:supported-privilege-set  . .
       5.3.  DAV:supported-privilege-set. . . . . . . . . . . . . . . 19
   5.3.1 18
             5.3.1. Example: Retrieving a List of Privileges
                    Supported on a Resource . . . . . . . . . . . . . . . . . . . . . . . . . . 20
   5.4 19
       5.4.  DAV:current-user-privilege-set . . . . . . . . . . . . . . . 22
   5.4.1 21
             5.4.1. Example: Retrieving the User's Current Set of
                    Assigned Privileges . . . . . . . . . . . . . . . . . . . . . . . . . 23
   5.5   DAV:acl  . . 22
       5.5.  DAV:acl. . . . . . . . . . . . . . . . . . . . . . . . . 24
   5.5.1 23
             5.5.1. ACE Principal . . . . . . . . . . . . . . . . . . . . . . . 24
   5.5.2 23
             5.5.2. ACE Grant and Deny Deny. . . . . . . . . . . . . . . . . . . . . . 26



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   5.5.3 25
             5.5.3. ACE Protection . . . . . Protection. . . . . . . . . . . . . . . . . . . 26
   5.5.4 25
             5.5.4. ACE Inheritance . . . . . . . . . . . . . . . . . . . . . . 26
   5.5.5 25
             5.5.5. Example: Retrieving a Resource's Access Control List .
                    List. . . . 26
   5.6   DAV:acl-restrictions . . . . . . . . . . . . . . . . . . . 25
       5.6.  DAV:acl-restrictions . 28
   5.6.1 DAV:grant-only . . . . . . . . . . . . . . . . . 27
             5.6.1. DAV:grant-only. . . . . . . 29
   5.6.2 DAV:no-invert ACE Constraint . . . . . . . . . . . 27
             5.6.2. DAV:no-invert ACE Constraint. . . . . . 29
   5.6.3 DAV:deny-before-grant . . . . . 28
             5.6.3. DAV:deny-before-grant . . . . . . . . . . . . . . 29
   5.6.4 28
             5.6.4. Required Principals . . . . . . . . . . . . . . . . . . . . 29
   5.6.5 28
             5.6.5. Example: Retrieving DAV:acl-restrictions DAV:acl-restrictions. . . . . . . . . . . 30
   5.7   DAV:inherited-acl-set  . . 28



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       5.7.  DAV:inherited-acl-set. . . . . . . . . . . . . . . . . . 31
   5.8 29
       5.8.  DAV:principal-collection-set . . . . . . . . . . . . . . . . 31
   5.8.1 30
             5.8.1. Example: Retrieving DAV:principal-collection-set . . . . . . 32
   5.9 DAV:principal-collection-set. 30
       5.9.  Example: PROPFIND to retrieve access control properties  . . 33 properties. 32
   6.  ACL Evaluation . . . . . . . . . . . . . . . . . . . . . . . 37 . 36
   7.  Access Control and existing methods methods. . . . . . . . . . . . . 39
   7.1 . 37
       7.1.  Any HTTP method  . . method. . . . . . . . . . . . . . . . . . . . . 39
   7.1.1 37
             7.1.1. Error Handling . . . . . . . Handling. . . . . . . . . . . . . . . . . 39
   7.2   OPTIONS  . . 37
       7.2.  OPTIONS. . . . . . . . . . . . . . . . . . . . . . . . . 40
   7.2.1 38
             7.2.1. Example - OPTIONS . . . . . . . . . . . . . . . . . . . . . 40
   7.3 39
       7.3.  MOVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
   7.4 39
       7.4.  COPY . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
   7.5 39
       7.5.  LOCK . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 39
   8.  Access Control Methods . . . . . . . . . . . . . . . . . . . 41
   8.1   ACL  . . 40
       8.1.  ACL. . . . . . . . . . . . . . . . . . . . . . . . . . . 41
   8.1.1 40
             8.1.1. ACL Preconditions . . . . . . . . . . . . . . . . . . . . . 42
   8.1.2 40
             8.1.2. Example: the ACL method . . . . . . . . . . . . . . . . . . 44
   8.1.3 42
             8.1.3. Example: ACL method failure due to protected
                    ACE conflict conflict. . . . 45
   8.1.4 Example: ACL method failure due to an inherited ACE
         conflict . . . . . . . . . . . . . . . 43
             8.1.4. Example: ACL method failure due to an
                    inherited ACE conflict. . . . . . . . . . . . . . 46
   8.1.5 44
             8.1.5. Example: ACL method failure due to an attempt
                    to set grant and deny in a single ACE . . . . . . 45
   9.  Access Control Reports . . . . . . . . . 47
   9.    Access Control Reports . . . . . . . . . . . . . . 46
       9.1.  REPORT Method. . . . . . 48
   9.1   REPORT Method . . . . . . . . . . . . . . . . 46
       9.2.  DAV:acl-principal-prop-set Report. . . . . . . . 48
   9.2   DAV:acl-principal-prop-set Report . . . . 47
             9.2.1. Example: DAV:acl-principal-prop-set Report. . . . 48
       9.3.  DAV:principal-match REPORT . . . . . . 49
   9.2.1 Example: DAV:acl-principal-prop-set Report . . . . . . . . . 50
   9.3 49
             9.3.1. Example: DAV:principal-match REPORT . . . . . . . 50
       9.4.  DAV:principal-property-search REPORT . . . . . . . . . . 51
   9.3.1 Example: DAV:principal-match REPORT
             9.4.1. Matching. . . . . . . . . . . . . 52
   9.4   DAV:principal-property-search REPORT . . . . . . . . . 53
             9.4.2. Example: successful DAV:principal-property-search
                    REPORT. . . . 53
   9.4.1 Matching . . . . . . . . . . . . . . . . . . 54
       9.5.  DAV:principal-search-property-set REPORT . . . . . . . . 56
   9.4.2
             9.5.1. Example: successful DAV:principal-property-search REPORT DAV:principal-search-property-set
                    REPORT. . . 56
   9.5   DAV:principal-search-property-set REPORT . . . . . . . . . . 58
   9.5.1 Example: DAV:principal-search-property-set REPORT . . . . . 60 . . . . 58
   10. XML Processing . . . . . . . . . . . . . . . . . . . . . . . 61 . 59
   11. Internationalization Considerations Considerations. . . . . . . . . . . . . 61 . 59
   12. Security Considerations Considerations. . . . . . . . . . . . . . . . . . . 62
   12.1 . 60
       12.1. Increased Risk of Compromised Users Users. . . . . . . . . . . . . 62
   12.2 60
       12.2. Risks of the DAV:read-acl and
             DAV:current-user-privilege-set Privileges  . Privileges. . . . . . . . . 63



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   12.3 60
       12.3. No Foreknowledge of Initial ACL  . . ACL. . . . . . . . . . . . . 63 61
   13. Authentication . . . . . . . . . . . . . . . . . . . . . . . 64 . 61
   14. IANA Considerations Considerations. . . . . . . . . . . . . . . . . . . . . 64 . 62
   15. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 64
         Normative . 62





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   16. References . . . . . . . . . . . . . . . . . . . . 64
         Informative References . . . . . . 62
       16.1. Normative References . . . . . . . . . . . . . . 65
         Authors' Addresses . . . . 62
       16.2. Informative References . . . . . . . . . . . . . . . . . 66 63
   Appendices
   A.  WebDAV XML Document Type Definition Addendum . . . . . . . . 67 . 64
   B.  WebDAV Method Privilege Table (Normative)  . . . . . . . . . 70
   C.    Resolved issues (to be removed by RFC Editor before
         publication) . . . . . . . . . . . . . . . . . . . . . . . . 71
   C.1   ED_references_names  . . (Normative). . . . . . . . . . . 67
   Index. . . . . . . . . 72
   C.2   ED_RFC2386 . . . . . . . . . . . . . . . . . . . . . . 69
   Authors' Addresses . . . 72
   C.3   ED_example_host_names . . . . . . . . . . . . . . . . . . . 72
   C.4   ED_authors_list . . 71
   Full Copyright Statement. . . . . . . . . . . . .  . . . . . . . . 72
   C.5   ED_non_ASCII . . . . . . . . . . . . . . . . . . . . . . . . 73
   C.6   ED_artwork_line_width  . . . . . . . . . . . . . . . . . . . 73
   C.7   ED_xml_typos . . . . . . . . . . . . . . . . . . . . . . . . 73
   C.8   1_ref_options  . . . . . . . . . . . . . . . . . . . . . . . 73
   C.9   3.2_ED_RFC2518 . . . . . . . . . . . . . . . . . . . . . . . 74
   C.10  3.3_ED_priv_section_titles . . . . . . . . . . . . . . . . . 74
   C.11  3.4_write-content-description  . . . . . . . . . . . . . . . 74
   C.12  3.12_ED_bad_reference  . . . . . . . . . . . . . . . . . . . 75
   C.13  4.1_ED_RFC2589 . . . . . . . . . . . . . . . . . . . . . . . 75
   C.14  5.1_owner_group_details  . . . . . . . . . . . . . . . . . . 75
   C.15  5.1_owner_href_optional  . . . . . . . . . . . . . . . . . . 76
   C.16  5.1.2_responsedescription  . . . . . . . . . . . . . . . . . 76
   C.17  5.5.5_ED_section_numbering . . . . . . . . . . . . . . . . . 76
   C.18  5.8_unbind . . . . . . . . . . . . . . . . . . . . . . . . . 76
   C.19  6_ED_RFC3010 . . . . . . . . . . . . . . . . . . . . . . . . 77
   C.20  6_group_property . . . . . . . . . . . . . . . . . . . . . . 77
   C.21  5.5.2_TYPO . . . . . . . . . . . . . . . . . . . . . . . . . 77
   C.22  9.4_ED_reference_casemap . . . . . . . . . . . . . . . . . . 78
   C.23  11_ED_RFC2279  . . . . . . . . . . . . . . . . . . . . . . . 78
   C.24  A_ED_appendices  . . . . . . . . . . . . . . . . . . . . . . 78
         Index  . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
         Intellectual Property and Copyright Statements . . . . . . . 82














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1. Introduction

   The goal of the WebDAV access control extensions is to provide an
   interoperable mechanism for handling discretionary access control for
   content and metadata managed by WebDAV servers.  WebDAV access
   control can be implemented on content repositories with security as
   simple as that of a UNIX file system, as well as more sophisticated
   models.  The underlying principle of access control is that who you
   are determines what operations you can perform on a resource. The
   "who you are" is defined by a "principal" identifier; users, client
   software, servers, and groups of the previous have principal
   identifiers. The "operations you can perform" are determined by a
   single "access control list" (ACL) associated with a resource.  An
   ACL contains a set of "access control entries" (ACEs), where each ACE
   specifies a principal and a set of privileges that are either granted
   or denied to that principal. When a principal submits an operation
   (such as an HTTP or WebDAV method) to a resource for execution, the
   server evaluates the ACEs in the ACL to determine if the principal
   has permission for that operation.

   Since every ACE contains the identifier of a principal, client
   software operated by a human must provide a mechanism for selecting
   this principal. This specification uses http(s) scheme URLs to
   identify principals, which are represented as WebDAV-capable
   resources. There is no guarantee that the URLs identifying principals
   will be meaningful to a human. For example, http://www.example.com/u/
   256432 and http://www.example.com/people/Greg.Stein are both valid
   URLs that could be used to identify the same principal. To remedy
   this, every principal resource has the DAV:displayname property
   containing a human-readable name for the principal.

   Since a principal can be identified by multiple URLs, it raises the
   problem of determining exactly which principal is being referenced in
   a given ACE. It is impossible for a client to determine that an ACE
   granting the read privilege to http://www.example.com/people/
   Greg.Stein also affects the principal at http://www.example.com/u/
   256432. That is, a client has no mechanism for determining that two
   URLs identify the same principal resource.  As a result, this
   specification requires clients to use just one of the many possible
   URLs for a principal when creating ACEs. A client can discover which
   URL to use by retrieving the DAV:principal-URL property (Section 4.2)
   from a principal resource. No matter which of the principal's URLs is
   used with PROPFIND, the property always returns the same URL.

   With a system having hundreds to thousands of principals, the problem
   arises of how to allow a human operator of client software to select
   just one of these principals. One approach is to use broad collection
   hierarchies to spread the principals over a large number of



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   collections, yielding few principals per collection. An example of
   this is a two level hierarchy with the first level containing 36
   collections (a-z, 0-9), and the second level being another 36,
   creating collections /a/a/, /a/b/, ..., /a/z/, such that a principal
   with last name "Stein" would appear at /s/t/Stein. In effect, this
   pre-computes a common query, search on last name, and encodes it into
   a hierarchy. The drawback with this scheme is that it handles only a
   small set of predefined queries, and drilling down through the
   collection hierarchy adds unnecessary steps (navigate down/up) when
   the user already knows the principal's name. While organizing
   principal URLs into a hierarchy is a valid namespace organization,
   users should not be forced to navigate this hierarchy to select a
   principal.

   This specification provides the capability to perform substring
   searches over a small set of properties on the resources representing
   principals. This permits searches based on last name, first name,
   user name, job title, etc. Two separate searches are supported, both
   via the REPORT method, one to search principal resources
   (DAV:principal-property-search, Section 9.4), the other to determine
   which properties may be searched at all
   (DAV:principal-search-property-set, Section 9.5).

   Once a principal has been identified in an ACE, a server evaluating
   that ACE must know the identity of the principal making a protocol
   request, and must validate that that principal is who they claim to
   be, a process known as authentication. This specification
   intentionally omits discussion of authentication, as the HTTP
   protocol already has a number of authentication mechanisms [RFC2617].
   Some authentication mechanism (such as HTTP Digest Authentication,
   which all WebDAV compliant implementations are required to support)
   must be available to validate the identity of a principal.

   The following issues are out of scope for this document:

   o  Access control that applies only to a particular property on a
      resource (excepting the access control properties DAV:acl and
      DAV:current-user-privilege-set), rather than the entire resource,

   o  Role-based security (where a role can be seen as a dynamically
      defined group of principals),

   o  Specification of the ways an ACL on a resource is initialized,

   o  Specification of an ACL that applies globally to all resources,
      rather than to a particular resource.

   o  Creation and maintenance of resources representing people or



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      computational agents (principals), and groups of these.

   This specification is organized as follows. Section 1.1 defines key
   concepts used throughout the specification, and is followed by a more
   in-depth discussion of principals (Section 2), and privileges
   (Section 3). Properties defined on principals are specified in
   Section 4, and access control properties for content resources are
   specified in Section 5. The ways ACLs are to be evaluated is
   described in Section 6. Client discovery of access control capability
   using OPTIONS is described in Section 7.2. Interactions between
   access control functionality and existing HTTP and WebDAV methods are
   described in the remainder of Section 7. The access control setting
   method, ACL, is specified in Section 8. Four reports that provide
   limited server-side searching capabilities are described in Section
   9. Sections on XML processing (Section 10), Internationalization
   considerations (Section 11), security considerations (Section 12),
   and authentication (Section 13) round out the specification. An
   appendix (Appendix A) provides an XML Document Type Definition (DTD)
   for the XML elements defined in the specification.

1.1 Terms

   This draft uses the terms defined in HTTP [RFC2616] and WebDAV
   [RFC2518].  In addition, the following terms are defined:

   principal

      A "principal" is a distinct human or computational actor that
      initiates access to network resources.  In this protocol, a
      principal is an HTTP resource that represents such an actor.

   group

      A "group" is a principal that represents a set of other
      principals.

   privilege

      A "privilege" controls access to a particular set of HTTP
      operations on a resource.

   aggregate privilege

      An "aggregate privilege" is a privilege that contains a set of
      other privileges.

   abstract privilege




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      The modifier "abstract", when applied to a privilege on a
      resource, means the privilege cannot be set in an access control
      element (ACE) on that resource.

   access control list (ACL)

      An "ACL" is a list of access control elements that define access
      control to a particular resource.

   access control element (ACE)

      An "ACE" either grants or denies a particular set of
      (non-abstract) privileges for a particular principal.

   inherited ACE

      An "inherited ACE" is an ACE that is dynamically shared from the
      ACL of another resource. When a shared ACE changes on the primary
      resource, it is also changed on inheriting resources.

   protected property

      A "protected property" is one whose value cannot be updated except
      by a method explicitly defined as updating that specific property.
      In particular, a protected property cannot be updated with a
      PROPPATCH request.


1.2 Notational Conventions

   The augmented BNF used by this document to describe protocol elements
   is described in Section 2.1 of [RFC2616]. Because this augmented BNF
   uses the basic production rules provided in Section 2.2 of [RFC2616],
   those rules apply to this document as well.

   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].

   Definitions of XML elements in this document use XML element type
   declarations (as found in XML Document Type Declarations), described
   in Section 3.2 of [REC-XML]. When an XML element type in the "DAV:"
   namespace is referenced in this document outside of the context

1.  Introduction

   The goal of an
   XML fragment, the string "DAV:" will be prefixed to the element name.

2. Principals

   A principal is a network resource that represents a distinct human or



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   computational actor that initiates access to network resources. Users
   and groups are represented as principals in many implementations;
   other types of principals are also possible. A URI of any scheme MAY
   be used to identify a principal resource. However, servers
   implementing this specification MUST expose principal resources at an
   http(s) URL, which control extensions is a privileged scheme that points to resources
   that have additional properties, as described in Section 4. So, a
   principal resource can have multiple URIs, one of which has to be an
   http(s) scheme URL. Although provide an implementation SHOULD support
   PROPFIND and MAY support PROPPATCH to
   interoperable mechanism for handling discretionary access control for
   content and modify information
   about a principal, it is not required to do so.

   A principal resource may metadata managed by WebDAV servers.  WebDAV access
   control can be a group, where a group is a principal implemented on content repositories with security as
   simple as that represents a set of other principals, called the members of the
   group.  If a person or computational agent matches a principal
   resource that is a member UNIX file system, as well as more sophisticated
   models.  The underlying principle of a group, they also match the group.
   Membership in a group access control is recursive, so if that who you
   are determines what operations you can perform on a principal resource.  The
   "who you are" is defined by a member of
   group GRPA, "principal" identifier; users, client
   software, servers, and GRPA is a member groups of group GRPB, then the previous have principal is
   also
   identifiers.  The "operations you can perform" are determined by a member
   single "access control list" (ACL) associated with a resource.  An
   ACL contains a set of GRPB.

3. Privileges

   Ability to perform "access control entries" (ACEs), where each ACE
   specifies a given method on principal and a resource MUST be controlled by
   one or more privileges.  Authors set of protocol extensions that define
   new HTTP methods SHOULD specify which privileges (by defining new
   privileges, or mapping to ones below) that are required to perform the
   method.  A principal with no privileges to a resource MUST be either granted
   or denied
   any HTTP access to that resource, unless the principal.  When a principal matches submits an ACE
   constructed using the DAV:all, DAV:authenticated, operation
   (such as an HTTP or
   DAV:unauthenticated pseudo-principals (see Section 5.5.1).  Servers
   MUST report WebDAV method) to a 403 "Forbidden" error if access is denied, except in resource for execution, the case where
   server evaluates the privilege restricts ACEs in the ability ACL to know determine if the
   resource exists, in which case 404 "Not Found" may be returned.

   Privileges may be containers principal
   has permission for that operation.

   Since every ACE contains the identifier of other privileges, in which case they
   are termed "aggregate privileges".  If a principal is granted or
   denied an aggregate privilege, it principal, client
   software operated by a human must provide a mechanism for selecting
   this principal.  This specification uses http(s) scheme URLs to
   identify principals, which are represented as WebDAV-capable
   resources.  There is semantically equivalent to
   granting or denying each of no guarantee that the aggregated privileges individually. URLs identifying
   principals will be meaningful to a human.  For example, an implementation may define add-member
   http://www.example.com/u/256432 and
   remove-member privileges
   http://www.example.com/people/Greg.Stein are both valid URLs that control the ability
   could be used to add and remove a
   member of a group.  Since these privileges control identify the ability to
   update same principal.  To remedy this, every
   principal resource has the state of DAV:displayname property containing a group, these privileges would
   human-readable name for the principal.

   Since a principal can be aggregated identified by multiple URLs, it raises the DAV:write privilege on
   problem of determining exactly which principal is being referenced in
   a group, and given ACE.  It is impossible for a client to determine that an ACE
   granting the DAV:write read privilege on a group would to http://www.example.com/people/
   Greg.Stein also grant affects the add-member and
   remove-member privileges.

   Privileges may be declared to be "abstract" for principal at http://www.example.com/u/
   256432.  That is, a given resource, in
   which case they cannot be set in an ACE on client has no mechanism for determining that resource. Aggregate two



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   and non-aggregate privileges are both capable of being abstract.
   Abstract privileges are useful for modeling privileges that otherwise
   would not be exposed via the protocol. Abstract privileges also
   provide server implementations with flexibility in implementing             May 2004


   URLs identify the
   privileges defined in same principal resource.  As a result, this specification.  For example, if
   specification requires clients to use just one of the many possible
   URLs for a principal when creating ACEs.  A client can discover which
   URL to use by retrieving the DAV:principal-URL property (Section 4.2)
   from a server
   is incapable principal resource.  No matter which of separating the read resource capability from principal's URLs
   is used with PROPFIND, the read
   ACL capability, it can still model property always returns the DAV:read and DAV:read-acl
   privileges defined in this specification by declaring them abstract,
   and containing them within same URL.

   With a non-abstract aggregate privilege (say,
   read-all) that holds DAV:read, and DAV:read-acl. In this way, it is
   possible system having hundreds to set the aggregate privilege, read-all, thus coupling thousands of principals, the
   setting problem
   arises of DAV:read and DAV:read-acl, but it is not possible how to set
   DAV:read, or DAV:read-acl individually. Since aggregate privileges
   can be abstract, it allow a human operator of client software to select
   just one of these principals.  One approach is also possible to use abstract privileges broad
   collection hierarchies to
   group or organize non-abstract privileges. Privilege containment
   loops are not allowed; therefore, spread the principals over a privilege MUST NOT contain
   itself. For example, DAV:read cannot contain DAV:read.

   The set large number
   of privileges that apply to a particular resource may vary
   with the DAV:resourcetype collections, yielding few principals per collection.  An example
   of the resource, as well as between
   different server implementations.  To promote interoperability,
   however, this specification defines is a set of well-known privileges
   (e.g. DAV:read, DAV:write, DAV:read-acl, DAV:write-acl,
   DAV:read-current-user-privilege-set, two level hierarchy with the first level containing 36
   collections (a-z, 0-9), and DAV:all), which can at least
   be used to classify the other privileges defined second level being another 36,
   creating collections /a/a/, /a/b/, ..., /a/z/, such that a principal
   with last name "Stein" would appear at /s/t/Stein.  In effect, this
   pre-computes a common query, search on last name, and encodes it into
   a particular
   resource. hierarchy.  The access permissions on null resources (defined in
   [RFC2518], Section 3) are solely those they inherit (if any), drawback with this scheme is that it handles only a
   small set of predefined queries, and
   they are not discoverable (i.e., drilling down through the access control properties
   specified in Section 5 are not defined on null resources). On
   collection hierarchy adds unnecessary steps (navigate down/up) when
   the
   transition from null to stateful resource, user already knows the initial access control
   list principal's name.  While organizing
   principal URLs into a hierarchy is set by the server's default ACL value policy (if any).

   Server implementations MAY define new privileges beyond those defined
   in this specification. Privileges defined by individual
   implementations MUST NOT use the DAV: namespace, and instead should
   use a valid namespace that they control, such as an http scheme URL.

3.1 DAV:read Privilege

   The read privilege controls methods that return information about organization,
   users should not be forced to navigate this hierarchy to select a
   principal.

   This specification provides the
   state capability to perform substring
   searches over a small set of properties on the resource, including resources representing
   principals.  This permits searches based on last name, first name,
   user name, job title, etc.  Two separate searches are supported, both
   via the resource's properties. Affected
   methods include GET and PROPFIND.  Any implementation-defined
   privilege that also controls access to GET and PROPFIND must be
   aggregated under DAV:read - if an ACL grants access REPORT method, one to DAV:read, search principal resources
   (DAV:principal-property-search, Section 9.4), the
   client may expect that no other privilege needs to determine
   which properties may be granted to have
   access to GET and PROPFIND.  Additionally, the read privilege MUST
   control the OPTIONS method.




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   <!ELEMENT read EMPTY>


3.2 DAV:write Privilege

   The write privilege controls methods that lock searched at all (DAV:principal-search-
   property-set, Section 9.5).

   Once a resource or modify
   the content, dead properties, or (in the case of principal has been identified in an ACE, a collection)
   membership server evaluating
   that ACE must know the identity of the resource, such as PUT principal making a protocol
   request, and PROPPATCH. Note must validate that
   state modification that principal is also controlled via locking (see section 5.3 who they claim to
   be, a process known as authentication.  This specification
   intentionally omits discussion of
   [RFC2518]), so effective write access requires that both write
   privileges and write locking requirements authentication, as the HTTP
   protocol already has a number of authentication mechanisms [RFC2617].
   Some authentication mechanism (such as HTTP Digest Authentication,
   which all WebDAV compliant implementations are satisfied.  Any
   implementation-defined privilege that also controls access required to methods
   modifying content, dead properties or collection membership support)
   must be
   aggregated under DAV:write, e.g. if an ACL grants access available to
   DAV:write, validate the client may expect that no other privilege needs to be
   granted to have access to PUT and PROPPATCH.

   <!ELEMENT write EMPTY>


3.3 DAV:write-properties Privilege identity of a principal.








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   The DAV:write-properties privilege controls methods that modify the
   dead properties following issues are out of the resource, such as PROPPATCH.  Whether scope for this
   privilege may be used to document:

   o  Access control access that applies only to any live properties is
   determined by a particular property on a
      resource (excepting the implementation.  Any implementation-defined
   privilege that also controls access to methods modifying dead control properties must be aggregated under DAV:write-properties - e.g. if an
   ACL grants access to DAV:write-properties, DAV:acl and
      DAV:current-user-privilege-set), rather than the client entire resource,

   o  Role-based security (where a role can safely
   expect that no other privilege needs to be granted to have access to
   PROPPATCH.

   <!ELEMENT write-properties EMPTY>


3.4 DAV:write-content Privilege

   The DAV:write-content privilege controls methods that modify seen as a dynamically
      defined group of principals),

   o  Specification of the
   content ways an ACL on a resource is initialized,

   o  Specification of an existing resource, such as PUT.  Any
   implementation-defined privilege ACL that also controls access applies globally to content
   must be aggregated under DAV:write-content - e.g. if an ACL grants
   access all resources,
      rather than to DAV:write-content, a particular resource.

   o  Creation and maintenance of resources representing people or
      computational agents (principals), and groups of these.

   This specification is organized as follows.  Section 1.1 defines key
   concepts used throughout the client can safely expect that no
   other privilege needs specification, and is followed by a more
   in-depth discussion of principals (Section 2), and privileges
   (Section 3).  Properties defined on principals are specified in
   Section 4, and access control properties for content resources are
   specified in Section 5.  The ways ACLs are to be granted to have evaluated is
   described in Section 6.  Client discovery of access control
   capability using OPTIONS is described in Section 7.2.  Interactions
   between access control functionality and existing HTTP and WebDAV
   methods are described in the remainder of Section 7.  The access to PUT. Note
   control setting method, ACL, is specified in Section 8.  Four reports
   that
   PUT - when applied to an unmapped URI - creates a new resource provide limited server-side searching capabilities are described
   in Section 9.  Sections on XML processing (Section 10),
   Internationalization considerations (Section 11), security
   considerations (Section 12), and
   therefore is controlled by authentication (Section 13) round
   out the DAV:bind privilege on specification.  An appendix (Appendix A) provides an XML
   Document Type Definition (DTD) for the parent
   collection.

   <!ELEMENT write-content EMPTY>



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3.5 DAV:unlock Privilege

   The DAV:unlock privilege controls XML elements defined in the use of
   specification.

1.1.  Terms

   This document uses the UNLOCK method by a
   principal other than terms defined in HTTP [RFC2616] and WebDAV
   [RFC2518].  In addition, the lock owner (the following terms are defined:

   principal that created a
   lock can always perform an UNLOCK).  While the set of users who may
   lock a resource

      A "principal" is most commonly the same set of users who may modify a resource, servers may allow various kinds of administrators to
   unlock resources locked by others. Any privilege controlling distinct human or computational actor that
      initiates access
   by non-lock owners to UNLOCK MUST be aggregated under DAV:unlock.

   A lock owner can always remove a lock by issuing an UNLOCK with the
   correct lock token and authentication credentials. That is, even if a
   principal does not have DAV:unlock privilege, they can still remove
   locks they own. Principals other than the lock owner can remove network resources.  In this protocol, a
   lock only if they have DAV:unlock privilege and they issue
      principal is an UNLOCK
   with the correct lock token. Lock timeout HTTP resource that represents such an actor.





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   group

      A "group" is not affected by the
   DAV:unlock privilege.

   <!ELEMENT unlock EMPTY>


3.6 DAV:read-acl Privilege

   The DAV:read-acl a principal that represents a set of other
      principals.

   privilege

      A "privilege" controls the use of PROPFIND access to retrieve
   the DAV:acl property a particular set of the HTTP
      operations on a resource.

   <!ELEMENT read-acl EMPTY>


3.7 DAV:read-current-user-privilege-set Privilege

   The DAV:read-current-user-privilege-set

   aggregate privilege controls the use of
   PROPFIND to retrieve the DAV:current-user-privilege-set property

      An "aggregate privilege" is a privilege that contains a set of
   the resource.

   Clients are intended to use this property
      other privileges.

   abstract privilege

      The modifier "abstract", when applied to visually indicate in
   their UI items that are dependent a privilege on the permissions of a
      resource,
   for example, by graying out resources that are not writeable.

   This means the privilege is separate from DAV:read-acl because there cannot be set in an access control
      element (ACE) on that resource.

   access control list (ACL)

      An "ACL" is a need
   to allow most users list of access control elements that define access
      control to the a particular resource.

   access control element (ACE)

      An "ACE" either grants or denies a particular set of (non-
      abstract) privileges permitted the current
   user (due to its use in creating the UI), while the full ACL contains
   information that may not be appropriate for the current authenticated
   user. As a result, particular principal.

   inherited ACE

      An "inherited ACE" is an ACE that is dynamically shared from the set
      ACL of users who can view another resource.  When a shared ACE changes on the full ACL primary
      resource, it is
   expected to also changed on inheriting resources.

   protected property

      A "protected property" is one whose value cannot be much smaller than those who can read the current user
   privilege set, and hence distinct privileges are needed for each.

   <!ELEMENT read-current-user-privilege-set EMPTY> updated except
      by a method explicitly defined as updating that specific property.
      In particular, a protected property cannot be updated with a
      PROPPATCH request.








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3.8 DAV:write-acl Privilege             May 2004


1.2.  Notational Conventions

   The DAV:write-acl privilege controls use of the ACL method augmented BNF used by this document to modify
   the DAV:acl property describe protocol elements
   is described in Section 2.1 of [RFC2616].  Because this augmented BNF
   uses the resource.

   <!ELEMENT write-acl EMPTY>


3.9 DAV:bind Privilege

   The DAV:bind privilege allows a method to add a new member URL basic production rules provided in Section 2.2 of [RFC2616],
   those rules apply to the
   specified collection (for example via PUT or MKCOL).  It is ignored
   for resources that are not collections.

   <!ELEMENT bind EMPTY>


3.10 DAV:unbind Privilege this document as well.

   The DAV:unbind privilege allows a method to remove a member URL from
   the specified collection (for example via DELETE or MOVE). It is
   ignored for resources that key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are not collections.

   <!ELEMENT unbind EMPTY>


3.11 DAV:all Privilege

   DAV:all is to be interpreted as described in [RFC2119].

   Definitions of XML elements in this document use XML element type
   declarations (as found in XML Document Type Declarations), described
   in Section 3.2 of [REC-XML].  When an aggregate privilege that contains XML element type in the entire set "DAV:"
   namespace is referenced in this document outside of
   privileges that can be applied to the resource.

   <!ELEMENT all EMPTY>


3.12 Aggregation context of Predefined Privileges

   Server implementations are free to aggregate an
   XML fragment, the predefined
   privileges (defined above in Sections 3.1-3.10) subject string "DAV:" will be prefixed to the
   following limitations:

   DAV:read-acl MUST NOT contain DAV:read, DAV:write, DAV:write-acl,
   DAV:write-properties, DAV:write-content, or
   DAV:read-current-user-privilege-set.

   DAV:write-acl MUST NOT contain DAV:write, DAV:read, DAV:read-acl, or
   DAV:read-current-user-privilege-set.

   DAV:read-current-user-privilege-set MUST NOT contain DAV:write,



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   DAV:read, DAV:read-acl, or DAV:write-acl.

   DAV:write MUST NOT contain DAV:read, DAV:read-acl, or
   DAV:read-current-user-privilege-set.

   DAV:read MUST NOT contain DAV:write, DAV:write-acl,
   DAV:write-properties, element name.

2.  Principals

   A principal is a network resource that represents a distinct human or DAV:write-content.

   DAV:write MUST contain DAV:bind, DAV:unbind, DAV:write-properties
   computational actor that initiates access to network resources.
   Users and
   DAV:write-content.

4. Principal Properties

   Principals groups are manifested represented as principals in many
   implementations; other types of principals are also possible.  A URI
   of any scheme MAY be used to clients identify a principal resource.  However,
   servers implementing this specification MUST expose principal
   resources at an http(s) URL, which is a privileged scheme that points
   to resources that have additional properties, as described in Section
   4.  So, a WebDAV resource, identified
   by principal resource can have multiple URIs, one of which has
   to be an http(s) scheme URL.  Although an implementation SHOULD
   support PROPFIND and MAY support PROPPATCH to access and modify
   information about a URL. principal, it is not required to do so.

   A principal MUST have resource may be a non-empty DAV:displayname property
   (defined in Section 13.2 of [RFC2518]), and group, where a DAV:resourcetype
   property (defined in Section 13.9 of [RFC2518]).  Additionally, group is a principal MUST report the DAV:principal XML element in
   that represents a set of other principals, called the value members of the DAV:resourcetype property.  The element type declaration for
   DAV:principal is:

   <!ELEMENT
   group.  If a person or computational agent matches a principal EMPTY>

   This protocol defines the following additional properties for
   resource that is a
   principal. Since it can be expensive for member of a server to retrieve access
   control information, group, they also match the name and value group.
   Membership in a group is recursive, so if a principal is a member of these properties SHOULD
   NOT be returned by
   group GRPA, and GRPA is a PROPFIND allprop request (as defined in Section
   12.14.1 member of [RFC2518]).

4.1 DAV:alternate-URI-set

   This protected property, if non-empty, contains group GRPB, then the URIs principal is
   also a member of network
   resources with additional descriptive information about the
   principal. This property identifies additional network resources
   (i.e., it contains GRPB.

3.  Privileges

   Ability to perform a given method on a resource MUST be controlled by
   one or more URIs) that may be consulted by a
   client to gain additional knowledge concerning a principal. One
   expected use for this property is the storage privileges.  Authors of an LDAP [RFC2255]
   scheme URL. A user-agent encountering an LDAP URL could use LDAP
   [RFC2251] to retrieve additional machine-readable directory
   information about the principal, and display protocol extensions that information in its
   user interface. Support for this property is REQUIRED, and define
   new HTTP methods SHOULD specify which privileges (by defining new
   privileges, or mapping to ones below) are required to perform the value
   is empty if
   method.  A principal with no alternate URI exists for privileges to a resource MUST be denied
   any HTTP access to that resource, unless the principal.

   <!ELEMENT alternate-URI-set (href*)> principal matches an ACE



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4.2 DAV:principal-URL

   A principal may have many URLs, but there must be one "principal URL"
   that clients can use to uniquely identify a principal.  This
   protected property contains             May 2004


   constructed using the URL that DAV:all, DAV:authenticated, or
   DAV:unauthenticated pseudo-principals (see Section 5.5.1).  Servers
   MUST be used report a 403 "Forbidden" error if access is denied, except in
   the case where the privilege restricts the ability to identify
   this principal know the
   resource exists, in an ACL request. Support for this property is
   REQUIRED.

   <!ELEMENT principal-URL (href)>


4.3 DAV:group-member-set

   This property which case 404 "Not Found" may be returned.

   Privileges may be containers of other privileges, in which case they
   are termed "aggregate privileges".  If a group principal identifies the principals that are
   direct members is granted or
   denied an aggregate privilege, it is semantically equivalent to
   granting or denying each of this group. Since a group the aggregated privileges individually.
   For example, an implementation may be define add-member and remove-
   member privileges that control the ability to add and remove a member
   of
   another group, a group may also have indirect members (i.e. group.  Since these privileges control the
   members of its direct members).  A URL in ability to update the DAV:group-member-set
   for
   state of a principal MUST group, these privileges would be aggregated by the DAV:principal-URL of that principal.

   <!ELEMENT group-member-set (href*)>


4.4 DAV:group-membership

   This protected property identifies the groups in which the principal
   is directly a member.  Note that
   DAV:write privilege on a server may allow group, and granting the DAV:write privilege
   on a group would also grant the add-member and remove-member
   privileges.

   Privileges may be declared to be "abstract" for a
   member of another group, given resource, in
   which case the DAV:group-membership of
   those other groups would need to they cannot be queried in order to determine the
   groups set in which the principal is indirectly a member. Support for
   this property is REQUIRED.

   <!ELEMENT group-membership (href*)>


5. Access Control Properties

   This specification defines a number an ACE on that resource.  Aggregate
   and non-aggregate privileges are both capable of new properties being abstract.
   Abstract privileges are useful for WebDAV
   resources.  Access control properties may modeling privileges that otherwise
   would not be retrieved just like
   other WebDAV properties, using exposed via the PROPFIND method.  Since it is
   expensive, for many servers, to retrieve access control information,
   a PROPFIND allprop request (as defined protocol.  Abstract privileges also
   provide server implementations with flexibility in Section 12.14.1 of
   [RFC2518]) SHOULD NOT return the names and values of implementing the properties
   privileges defined in this section.

   Access control properties (especially DAV:acl and
   DAV:inherited-acl-set) are defined on the resource identified by the
   Request-URI of specification.  For example, if a PROPFIND request. A direct consequence server
   is that if incapable of separating the read resource is accessible via multiple URI, the value of access



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   control properties is capability from the same across these URI.

   HTTP resources read
   ACL capability, it can still model the DAV:read and DAV:read-acl
   privileges defined in this specification by declaring them abstract,
   and containing them within a non-abstract aggregate privilege (say,
   read-all) that support holds DAV:read, and DAV:read-acl.  In this way, it is
   possible to set the WebDAV Access Control Protocol MUST
   contain aggregate privilege, read-all, thus coupling the following properties. Null resources (described in
   Section 3
   setting of [RFC2518]) DAV:read and DAV:read-acl, but it is not possible to set
   DAV:read, or DAV:read-acl individually.  Since aggregate privileges
   can be abstract, it is also possible to use abstract privileges to
   group or organize non-abstract privileges.  Privilege containment
   loops are not allowed; therefore, a privilege MUST NOT contain the following properties.

5.1 DAV:owner

   This  property identifies a particular principal as being the "owner"
   of the resource. Since the owner
   itself.  For example, DAV:read cannot contain DAV:read.

   The set of privileges that apply to a particular resource often has special
   access control capabilities (e.g., may vary
   with the owner frequently has permanent
   DAV:write-acl privilege), clients might display DAV:resourcetype of the resource owner in
   their user interface.

   Servers MAY implement DAV:owner resource, as protected property and MAY return
   an empty DAV:owner element well as property value in case no owner
   information is available.

   <!ELEMENT owner (href?)>


5.1.1 Example: Retrieving DAV:owner

   This example shows between
   different server implementations.  To promote interoperability,
   however, this specification defines a client request for the value set of well-known privileges
   (e.g., DAV:read, DAV:write, DAV:read-acl, DAV:write-acl, DAV:read-
   current-user-privilege-set, and DAV:all), which can at least be used
   to classify the DAV:owner
   property from a collection resource with URL http://www.example.com/
   papers/. The principal making the request is authenticated using
   Digest authentication. other privileges defined on a particular resource.
   The value of DAV:owner is the URL http://
   www.example.com/acl/users/gstein, wrapped access permissions on null resources (defined in [RFC2518],
   Section 3) are solely those they inherit (if any), and they are not
   discoverable (i.e., the DAV:href XML
   element.

   >> Request <<

   PROPFIND /papers/ HTTP/1.1
   Host: www.example.com
   Content-type: text/xml; charset="utf-8"
   Content-Length: xxx
   Depth: 0
   Authorization: Digest username="jim",
     realm="users@example.com", nonce="...",
     uri="/papers/", response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:propfind xmlns:D="DAV:">
     <D:prop>
       <D:owner/>
     </D:prop>
   </D:propfind> access control properties specified in



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   >> Response <<

   HTTP/1.1 207 Multi-Status
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:">
     <D:response>
       <D:href>http://www.example.com/papers/</D:href>
       <D:propstat>
         <D:prop>
           <D:owner>
             <D:href>http://www.example.com/acl/users/gstein</D:href>
           </D:owner>
         </D:prop>
         <D:status>HTTP/1.1 200 OK</D:status>
       </D:propstat>
     </D:response>
   </D:multistatus>


5.1.2 Example: An Attempt             May 2004


   Section 5 are not defined on null resources).  On the transition from
   null to Set DAV:owner

   The following example shows stateful resource, the initial access control list is set by
   the server's default ACL value policy (if any).

   Server implementations MAY define new privileges beyond those defined
   in this specification.  Privileges defined by individual
   implementations MUST NOT use the DAV: namespace, and instead should
   use a namespace that they control, such as an http scheme URL.

3.1.  DAV:read Privilege

   The read privilege controls methods that return information about the
   state of the resource, including the resource's properties.  Affected
   methods include GET and PROPFIND.  Any implementation-defined
   privilege that also controls access to GET and PROPFIND must be
   aggregated under DAV:read - if an ACL grants access to DAV:read, the
   client request may expect that no other privilege needs to modify the value of be granted to have
   access to GET and PROPFIND.  Additionally, the DAV:owner property on read privilege MUST
   control the resource with URL <http://
   www.example.com/papers>. Since DAV:owner is a protected property on
   this particular server, it responds with a 207 (Multi-Status)
   response OPTIONS method.

   <!ELEMENT read EMPTY>

3.2.  DAV:write Privilege

   The write privilege controls methods that contains lock a 403 (Forbidden) status code for resource or modify
   the act of
   setting DAV:owner. Section 8.2.1 content, dead properties, or (in the case of [RFC2518] describes PROPPATCH
   status code information,  Section 11 a collection)
   membership of [RFC2518] describes the
   Multi-Status response and Sections 1.6 resource, such as PUT and 3.12 PROPPATCH.  Note that
   state modification is also controlled via locking (see section 5.3 of [RFC3253] describe
   additional error marshalling for PROPPATCH attempts on protected
   properties.

















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   >> Request <<

   PROPPATCH /papers/ HTTP/1.1
   Host: www.example.com
   Content-type: text/xml; charset="utf-8"
   Content-Length: xxx
   Depth: 0
   Authorization: Digest username="jim",
     realm="users@example.com", nonce="...",
     uri="/papers/", response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:propertyupdate xmlns:D="DAV:">
     <D:set>
       <D:prop>
         <D:owner>
           <D:href>http://www.example.com/acl/users/jim</D:href>
         </D:owner>
       </D:prop>
     </D:set>
   </D:propertyupdate>

   >> Response <<

   HTTP/1.1 207 Multi-Status
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:">
     <D:response>
       <D:href>http://www.example.com/papers/</D:href>
       <D:propstat>
         <D:prop><D:owner/></D:prop>
         <D:status>HTTP/1.1 403 Forbidden</D:status>
         <D:responsedescription>
           <D:error><D:cannot-modify-protected-property/></D:error>
           Failure
   [RFC2518]), so effective write access requires that both write
   privileges and write locking requirements are satisfied.  Any
   implementation-defined privilege that also controls access to methods
   modifying content, dead properties or collection membership must be
   aggregated under DAV:write, e.g., if an ACL grants access to
   DAV:write, the client may expect that no other privilege needs to set protected property (DAV:owner)
         </D:responsedescription>
       </D:propstat>
     </D:response>
   </D:multistatus>


5.2 DAV:group

   This property identifies a particular principal as being be
   granted to have access to PUT and PROPPATCH.

   <!ELEMENT write EMPTY>

3.3.  DAV:write-properties Privilege

   The DAV:write-properties privilege controls methods that modify the "group"
   dead properties of the resource. This property resource, such as PROPPATCH.  Whether this
   privilege may be used to control access to any live properties is commonly found on repositories
   determined by the implementation.  Any implementation-defined
   privilege that also controls access to methods modifying dead
   properties must be aggregated under DAV:write-properties - e.g., if





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   implement the Unix privileges model.

   Servers MAY implement DAV:group as protected property and MAY return             May 2004


   an empty DAV:group element as property value in case ACL grants access to DAV:write-properties, the client can safely
   expect that no group
   information is available. other privilege needs to be granted to have access to
   PROPPATCH.

   <!ELEMENT group (href?)>


5.3 DAV:supported-privilege-set

   This is a protected property write-properties EMPTY>

3.4.  DAV:write-content Privilege

   The DAV:write-content privilege controls methods that identifies modify the privileges
   content of an existing resource, such as PUT.  Any implementation-
   defined
   for the resource.

   <!ELEMENT supported-privilege-set (supported-privilege*)>

   Each privilege appears as that also controls access to content must be
   aggregated under DAV:write-content - e.g., if an XML element, where aggregate privileges
   list as sub-elements all of ACL grants access to
   DAV:write-content, the privileges client can safely expect that they aggregate.

   <!ELEMENT supported-privilege
    (privilege, abstract?, description, supported-privilege*)>
   <!ELEMENT privilege ANY>

   An abstract no other
   privilege MUST NOT needs to be used in an ACE for granted to have access to PUT.  Note that resource.
   Servers MUST fail an attempt PUT -
   when applied to set an abstract privilege. unmapped URI - creates a new resource and
   therefore is controlled by the DAV:bind privilege on the parent
   collection.

   <!ELEMENT abstract write-content EMPTY>

   A description is a human-readable description of what this

3.5.  DAV:unlock Privilege

   The DAV:unlock privilege controls access to. Servers MUST indicate the human language use of the
   description using UNLOCK method by a
   principal other than the xml:lang attribute and SHOULD consider lock owner (the principal that created a
   lock can always perform an UNLOCK).  While the HTTP
   Accept-Language request header when selecting one set of multiple
   available languages.

   <!ELEMENT description #PCDATA>

   It is envisioned that users who may
   lock a WebDAV ACL-aware administrative client would
   list resource is most commonly the supported privileges in same set of users who may modify
   a dialog box, and resource, servers may allow the user to
   choose non-abstract privileges to apply in an ACE.  The privileges
   tree is useful programmatically various kinds of administrators to map well-known privileges (defined
   by WebDAV or other standards groups) into privileges that are
   supported
   unlock resources locked by any particular server implementation.  The others.  Any privilege
   tree also serves to hide complexity in implementations allowing large
   number of privileges to be defined controlling access
   by displaying aggregates non-lock owners to the
   user.






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5.3.1 Example: Retrieving a List of Privileges Supported on a Resource

   This example shows UNLOCK MUST be aggregated under DAV:unlock.

   A lock owner can always remove a client request for the
   DAV:supported-privilege-set property on lock by issuing an UNLOCK with the resource http://
   www.example.com/papers/. The value of
   correct lock token and authentication credentials.  That is, even if
   a principal does not have DAV:unlock privilege, they can still remove
   locks they own.  Principals other than the DAV:supported-privilege-set
   property is lock owner can remove a tree of supported privileges (using "[XML Namespace ,
   localname]" to identify each privilege):

     [DAV:, all] (aggregate, abstract)
        |
        +-- [DAV:, read] (aggregate)
               |
               +-- [DAV:, read-acl] (abstract)
               +-- [DAV:, read-current-user-privilege-set] (abstract)
        |
        +-- [DAV:, write] (aggregate)
               |
               +-- [DAV:, write-acl] (abstract)
               +-- [DAV:, write-properties]
               +-- [DAV:, write-content]
        |
        +-- [DAV:, unlock]

   This
   lock only if they have DAV:unlock privilege tree and they issue an UNLOCK
   with the correct lock token.  Lock timeout is not normative (except that it reflects affected by the
   normative aggregation rules given in Section 3.12), and many possible
   DAV:unlock privilege.

   <!ELEMENT unlock EMPTY>

3.6.  DAV:read-acl Privilege

   The DAV:read-acl privilege trees are possible.

   >> Request << controls the use of PROPFIND /papers/ HTTP/1.1
   Host: www.example.com
   Content-type: text/xml; charset="utf-8"
   Content-Length: xxx
   Depth: 0
   Authorization: Digest username="gclemm",
     realm="users@example.com", nonce="...",
     uri="/papers/", response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:propfind xmlns:D="DAV:">
     <D:prop>
       <D:supported-privilege-set/>
     </D:prop>
   </D:propfind>

   >> Response <<

   HTTP/1.1 207 Multi-Status



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   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:">
     <D:response>
       <D:href>http://www.example.com/papers/</D:href>
       <D:propstat>
         <D:prop>
           <D:supported-privilege-set>
             <D:supported-privilege>
               <D:privilege><D:all/></D:privilege>
              <D:abstract/>
               <D:description xml:lang="en">
                 Any operation
               </D:description>
               <D:supported-privilege>
                 <D:privilege><D:read/></D:privilege>
                 <D:description xml:lang="en">
                   Read any object
                 </D:description>
                 <D:supported-privilege>
                   <D:privilege><D:read-acl/></D:privilege>
                   <D:abstract/>
                   <D:description xml:lang="en">Read ACL</D:description>
                 </D:supported-privilege>
                 <D:supported-privilege>
                   <D:privilege>
                     <D:read-current-user-privilege-set/>
                   </D:privilege>
                   <D:abstract/>
                   <D:description xml:lang="en">
                     Read current user privilege set to retrieve
   the DAV:acl property
                   </D:description>
                 </D:supported-privilege>
               </D:supported-privilege>
               <D:supported-privilege>
                 <D:privilege><D:write/></D:privilege>
                 <D:description xml:lang="en">
                   Write any object
                 </D:description>
                 <D:supported-privilege>
                   <D:privilege><D:write-acl/></D:privilege>
                   <D:description xml:lang="en">
                     Write ACL
                   </D:description>
                   <D:abstract/>
                 </D:supported-privilege> of the resource.

   <!ELEMENT read-acl EMPTY>





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                 <D:supported-privilege>
                   <D:privilege><D:write-properties/></D:privilege>
                   <D:description xml:lang="en">
                     Write properties
                   </D:description>
                 </D:supported-privilege>
                 <D:supported-privilege>
                   <D:privilege><D:write-content/></D:privilege>
                   <D:description xml:lang="en">
                     Write resource content
                   </D:description>
                 </D:supported-privilege>
               </D:supported-privilege>
               <D:supported-privilege>
                 <D:privilege><D:unlock/></D:privilege>
                 <D:description xml:lang="en">
                   Unlock resource
                 </D:description>
               </D:supported-privilege>
             </D:supported-privilege>
           </D:supported-privilege-set>
         </D:prop>
         <D:status>HTTP/1.1 200 OK</D:status>
       </D:propstat>
     </D:response>
   </D:multistatus>


5.4 DAV:current-user-privilege-set

   DAV:current-user-privilege-set is a protected property containing             May 2004


3.7.  DAV:read-current-user-privilege-set Privilege

   The DAV:read-current-user-privilege-set privilege controls the
   exact set use of privileges (as computed by the server) granted
   PROPFIND to retrieve the
   currently authenticated HTTP user. Aggregate privileges and their
   contained privileges DAV:current-user-privilege-set property of
   the resource.

   Clients are listed. A user-agent can intended to use the value of this property to adjust its user interface to make actions
   inaccessible (e.g., visually indicate in
   their UI items that are dependent on the permissions of a resource,
   for example, by graying out resources that are not writable.

   This privilege is separate from DAV:read-acl because there is a menu item or button) for which need
   to allow most users access to the privileges permitted the current principal does
   user (due to its use in creating the UI), while the full ACL contains
   information that may not have permission. This property is also
   useful be appropriate for determining what operations the current principal authenticated
   user.  As a result, the set of users who can
   perform, without having view the full ACL is
   expected to actually execute an operation. be much smaller than those who can read the current user
   privilege set, and hence distinct privileges are needed for each.

   <!ELEMENT current-user-privilege-set (privilege*)> read-current-user-privilege-set EMPTY>

3.8.  DAV:write-acl Privilege

   The DAV:write-acl privilege controls use of the ACL method to modify
   the DAV:acl property of the resource.

   <!ELEMENT write-acl EMPTY>

3.9.  DAV:bind Privilege

   The DAV:bind privilege ANY>

   If allows a method to add a new member URL to the current user
   specified collection (for example via PUT or MKCOL).  It is granted a specific privilege, ignored
   for resources that are not collections.

   <!ELEMENT bind EMPTY>

3.10.  DAV:unbind Privilege

   The DAV:unbind privilege
   must belong allows a method to the set of privileges that may be set on this
   resource. Therefore, each element in the
   DAV:current-user-privilege-set property MUST identify remove a non-abstract
   privilege member URL from
   the DAV:supported-privilege-set property. specified collection (for example via DELETE or MOVE).  It is
   ignored for resources that are not collections.

   <!ELEMENT unbind EMPTY>









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5.4.1 Example: Retrieving             May 2004


3.11.  DAV:all Privilege

   DAV:all is an aggregate privilege that contains the User's Current Set entire set of Assigned Privileges

   Continuing the example from Section 5.3.1, this example shows a
   client requesting the DAV:current-user-privilege-set property from
   privileges that can be applied to the resource with URL http://www.example.com/papers/. The username resource.

   <!ELEMENT all EMPTY>

3.12.  Aggregation of Predefined Privileges

   Server implementations are free to aggregate the principal making predefined
   privileges (defined above in Sections 3.1-3.10) subject to the request is "khare",
   following limitations:

   DAV:read-acl MUST NOT contain DAV:read, DAV:write, DAV:write-acl,
   DAV:write-properties, DAV:write-content, or DAV:read-current-user-
   privilege-set.

   DAV:write-acl MUST NOT contain DAV:write, DAV:read, DAV:read-acl, or
   DAV:read-current-user-privilege-set.

   DAV:read-current-user-privilege-set MUST NOT contain DAV:write,
   DAV:read, DAV:read-acl, or DAV:write-acl.

   DAV:write MUST NOT contain DAV:read, DAV:read-acl, or DAV:read-
   current-user-privilege-set.

   DAV:read MUST NOT contain DAV:write, DAV:write-acl, DAV:write-
   properties, or DAV:write-content.

   DAV:write MUST contain DAV:bind, DAV:unbind, DAV:write-properties and Digest
   authentication is used
   DAV:write-content.

4.  Principal Properties

   Principals are manifested to clients as a WebDAV resource, identified
   by a URL.  A principal MUST have a non-empty DAV:displayname property
   (defined in the request. The principal with username
   "khare" has been granted the DAV:read privilege. Since the DAV:read
   privilege contains the DAV:read-acl Section 13.2 of [RFC2518]), and
   DAV:read-current-user-privilege-set privileges (see a DAV:resourcetype
   property (defined in Section 5.3.1),
   the 13.9 of [RFC2518]).  Additionally, a
   principal with username "khare" can read the ACL property, and
   the DAV:current-user-privilege-set property. However, MUST report the DAV:all,
   DAV:read-acl, DAV:write-acl and DAV:read-current-user-privilege-set
   privileges are not listed DAV:principal XML element in the value of
   DAV:current-user-privilege-set, since (for this example) they are
   abstract privileges. DAV:write is not listed since
   the DAV:resourcetype property.  The element type declaration for
   DAV:principal is:

   <!ELEMENT principal with
   username "khare" is not listed in an ACE granting that principal
   write permission.

   >> Request <<

   PROPFIND /papers/ HTTP/1.1
   Host: www.example.com
   Content-type: text/xml; charset="utf-8"
   Content-Length: xxx
   Depth: 0
   Authorization: Digest username="khare",
     realm="users@example.com", nonce="...",
     uri="/papers/", response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:propfind xmlns:D="DAV:">
     <D:prop>
       <D:current-user-privilege-set/>
     </D:prop>
   </D:propfind> EMPTY>








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   >> Response <<

   HTTP/1.1 207 Multi-Status
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:">
     <D:response>
     <D:href>http://www.example.com/papers/</D:href>
     <D:propstat>
       <D:prop>
         <D:current-user-privilege-set>
           <D:privilege><D:read/></D:privilege>
         </D:current-user-privilege-set>
       </D:prop>
       <D:status>HTTP/1.1 200 OK</D:status>
     </D:propstat>
     </D:response>
   </D:multistatus>


5.5 DAV:acl             May 2004


   This is protocol defines the following additional properties for a
   principal.  Since it can be expensive for a server to retrieve access
   control information, the name and value of these properties SHOULD
   NOT be returned by a PROPFIND allprop request (as defined in Section
   12.14.1 of [RFC2518]).

4.1.  DAV:alternate-URI-set

   This protected property, if non-empty, contains the URIs of network
   resources with additional descriptive information about the
   principal.  This property identifies additional network resources
   (i.e., it contains one or more URIs) that specifies the list of access
   control entries (ACEs), which define what principals are may be consulted by a
   client to get what
   privileges gain additional knowledge concerning a principal.  One
   expected use for this resource.

   <!ELEMENT acl (ace*) >

   Each DAV:ace element specifies property is the set storage of privileges to be either
   granted or denied an LDAP [RFC2255]
   scheme URL.  A user-agent encountering an LDAP URL could use LDAP
   [RFC2251] to a single principal.  If retrieve additional machine-readable directory
   information about the DAV:acl principal, and display that information in its
   user interface.  Support for this property is
   empty, no principal REQUIRED, and the value
   is granted any privilege.

   <!ELEMENT ace ((principal | invert), (grant|deny), protected?,
                  inherited?)>


5.5.1 ACE Principal

   The DAV:principal element identifies empty if no alternate URI exists for the principal to which this ACE
   applies. principal.

   <!ELEMENT alternate-URI-set (href*)>

4.2.  DAV:principal-URL

   A principal (href | all | authenticated | unauthenticated
    | property | self)>

   The current user matches DAV:href only if may have many URLs, but there must be one "principal URL"
   that user is authenticated
   as being (or being clients can use to uniquely identify a member of) the principal identified by principal.  This
   protected property contains the URL



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   contained by that DAV:href.

   The current user always matches DAV:all.

   <!ELEMENT all EMPTY>

   The current user matches DAV:authenticated only if authenticated.

   <!ELEMENT authenticated EMPTY>

   The current user matches DAV:unauthenticated only if not
   authenticated.

   <!ELEMENT unauthenticated EMPTY>

   DAV:all MUST be used to identify
   this principal in an ACL request.  Support for this property is the union
   REQUIRED.

   <!ELEMENT principal-URL (href)>

4.3.  DAV:group-member-set

   This property of DAV:authenticated, and DAV:unauthenticated.
   For a given request, group principal identifies the user matches either DAV:authenticated, or
   DAV:unauthenticated, but not both (that is, DAV:authenticated and
   DAV:unauthenticated principals that are disjoint sets).

   The current user matches
   direct members of this group.  Since a DAV:property principal in group may be a DAV:acl
   property member of
   another group, a resource only if group may also have indirect members (i.e., the value
   members of its direct members).  A URL in the identified property
   of that resource contains at most one DAV:href XML element, DAV:group-member-set
   for a principal MUST be the URI
   value DAV:principal-URL of DAV:href that principal.

   <!ELEMENT group-member-set (href*)>

4.4.  DAV:group-membership

   This protected property identifies a principal, and the current user groups in which the principal
   is
   authenticated as being (or being directly a member of) member.  Note that principal.  For
   example, if the DAV:property element contained <DAV:owner/>, a server may allow a group to be a
   member of another group, in which case the
   current user DAV:group-membership of




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   those other groups would match the DAV:property principal only if need to be queried in order to determine the
   current user is authenticated as matching
   groups in which the principal identified by
   the DAV:owner is indirectly a member.  Support for
   this property is REQUIRED.

   <!ELEMENT group-membership (href*)>

5.  Access Control Properties

   This specification defines a number of new properties for WebDAV
   resources.  Access control properties may be retrieved just like
   other WebDAV properties, using the PROPFIND method.  Since it is
   expensive, for many servers, to retrieve access control information,
   a PROPFIND allprop request (as defined in Section 12.14.1 of
   [RFC2518]) SHOULD NOT return the names and values of the resource.

   <!ELEMENT property ANY>

   The current user matches DAV:self properties
   defined in a this section.

   Access control properties (especially DAV:acl property of and DAV:inherited-acl-
   set) are defined on the resource only if that resource is identified by the Request-URI of a principal and
   PROPFIND request.  A direct consequence is that principal
   matches the current user or, if the principal resource is a group, a member
   accessible via multiple URI, the value of
   that group matches access control properties
   is the current user.

   <!ELEMENT self EMPTY>

   Some servers may same across these URI.

   HTTP resources that support ACEs applying to those users NOT matching
   the current principal, e.g. all users not in a particular group.
   This can be done by wrapping the DAV:principal element with
   DAV:invert.

   <!ELEMENT invert principal>






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5.5.2 ACE Grant and Deny

   Each DAV:grant or DAV:deny element specifies MUST
   contain the set following properties.  Null resources (described in
   Section 3 of privileges to
   be either granted or denied to [RFC2518]) MUST NOT contain the specified principal.  A DAV:grant
   or DAV:deny element following properties.

5.1.  DAV:owner

   This  property identifies a particular principal as being the "owner"
   of the DAV:acl resource.  Since the owner of a resource MUST only contain
   non-abstract elements specified in often has special
   access control capabilities (e.g., the DAV:supported-privilege-set of
   that resource.

   <!ELEMENT grant (privilege+)>
   <!ELEMENT deny (privilege+)>
   <!ELEMENT privilege ANY>


5.5.3 ACE Protection

   A server indicates an ACE is protected by including owner frequently has permanent
   DAV:write-acl privilege), clients might display the DAV:protected
   element resource owner in
   their user interface.

   Servers MAY implement DAV:owner as protected property and MAY return
   an empty DAV:owner element as property value in case no owner
   information is available.

   <!ELEMENT owner (href?)>

5.1.1.  Example: Retrieving DAV:owner

   This example shows a client request for the ACE. If the ACL value of the DAV:owner
   property from a collection resource contains an ACE with a
   DAV:protected element, an attempt to remove that ACE from URL http://www.example.com/
   papers/.  The principal making the ACL
   MUST fail.

   <!ELEMENT protected EMPTY>


5.5.4 ACE Inheritance request is authenticated using
   Digest authentication.  The presence value of a DAV:inherited element indicates that this ACE is
   inherited from another resource that DAV:owner is identified by the URL
   contained http://
   www.example.com/acl/users/gstein, wrapped in a the DAV:href XML
   element.  An inherited ACE cannot be modified
   directly, but instead the ACL on the resource from which it is
   inherited must be modified.

   Note that ACE inheritance is not the same as ACL initialization. ACL
   initialization defines the ACL that a newly created resource will use
   (if not specified).  ACE inheritance refers to an ACE that is
   logically shared - where an update to the resource containing an ACE
   will affect the ACE of each resource that inherits that ACE.  The
   method by which ACLs are initialized or by which ACEs are inherited
   is not defined by this document.

   <!ELEMENT inherited (href)>


5.5.5



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   >> Request <<

   PROPFIND /papers/ HTTP/1.1
   Host: www.example.com
   Content-type: text/xml; charset="utf-8"
   Content-Length: xxx
   Depth: 0
   Authorization: Digest username="jim",
     realm="users@example.com", nonce="...",
     uri="/papers/", response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:propfind xmlns:D="DAV:">
     <D:prop>
       <D:owner/>
     </D:prop>
   </D:propfind>

   >> Response <<

   HTTP/1.1 207 Multi-Status
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:">
     <D:response>
       <D:href>http://www.example.com/papers/</D:href>
       <D:propstat>
         <D:prop>
           <D:owner>
             <D:href>http://www.example.com/acl/users/gstein</D:href>
           </D:owner>
         </D:prop>
         <D:status>HTTP/1.1 200 OK</D:status>
       </D:propstat>
     </D:response>
   </D:multistatus>

5.1.2.  Example: Retrieving a Resource's Access Control List

   Continuing the example from Sections 5.3.1 and 5.4.1, this An Attempt to Set DAV:owner

   The following example shows a client requesting request to modify the DAV:acl value of
   the DAV:owner property from on the resource with URL http://www.example.com/papers/. There are two ACEs defined in <http://
   www.example.com/papers>.  Since DAV:owner is a protected property on
   this ACL: particular server, it responds with a 207 (Multi-Status)
   response that contains a 403 (Forbidden) status code for the act of
   setting DAV:owner.  Section 8.2.1 of [RFC2518] describes PROPPATCH
   status code information,  Section 11 of [RFC2518] describes the



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   ACE #1: The group identified by URL http://www.example.com/acl/
   groups/maintainers (the group of site maintainers) is granted
   DAV:write privilege. Since (for this example) DAV:write contains the
   DAV:write-acl privilege (see Section 5.3.1), this means the
   "maintainers" group can also modify the access control list.

   ACE #2: All principals (DAV:all) are granted the DAV:read privilege.
   Since (for this example) DAV:read contains DAV:read-acl             May 2004


   Multi-Status response and
   DAV:read-current-user-privilege-set, this means all users (including
   all members of the "maintainers" group) can read the DAV:acl property Sections 1.6 and the DAV:current-user-privilege-set property. 3.12 of [RFC3253] describe
   additional error marshaling for PROPPATCH attempts on protected
   properties.

   >> Request <<

   PROPFIND

   PROPPATCH /papers/ HTTP/1.1
   Host: www.example.com
   Content-type: text/xml; charset="utf-8"
   Content-Length: xxx
   Depth: 0
   Authorization: Digest username="masinter", username="jim",
     realm="users@example.com", nonce="...",
     uri="/papers/", response="...", opaque="..."

   <D:propfind

   <?xml version="1.0" encoding="utf-8" ?>
   <D:propertyupdate xmlns:D="DAV:">
     <D:set>
       <D:prop>
       <D:acl/>
         <D:owner>
           <D:href>http://www.example.com/acl/users/jim</D:href>
         </D:owner>
       </D:prop>
   </D:propfind>























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     </D:set>
   </D:propertyupdate>

   >> Response <<

   HTTP/1.1 207 Multi-Status
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:">
     <D:response>
       <D:href>http://www.example.com/papers/</D:href>
       <D:propstat>
         <D:prop>
           <D:acl>
           <D:ace>
             <D:principal>
               <D:href
               >http://www.example.com/acl/groups/maintainers</D:href>
             </D:principal>
             <D:grant>
               <D:privilege><D:write/></D:privilege>
             </D:grant>
           </D:ace>
           <D:ace>
             <D:principal>
               <D:all/>
             </D:principal>
             <D:grant>
               <D:privilege><D:read/></D:privilege>
             </D:grant>
           </D:ace>
         </D:acl>
         </D:prop>
         <D:prop><D:owner/></D:prop>
         <D:status>HTTP/1.1 200 OK</D:status> 403 Forbidden</D:status>
         <D:responsedescription>
           <D:error><D:cannot-modify-protected-property/></D:error>
           Failure to set protected property (DAV:owner)
         </D:responsedescription>
       </D:propstat>
     </D:response>
   </D:multistatus>


5.6 DAV:acl-restrictions





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5.2.  DAV:group

   This protected property defines identifies a particular principal as being the types "group"
   of ACLs supported by this
   server, to avoid clients needlessly getting errors.  When a client
   tries to set the resource.  This property is commonly found on repositories
   that implement the Unix privileges model.

   Servers MAY implement DAV:group as protected property and MAY return
   an ACL via empty DAV:group element as property value in case no group
   information is available.

   <!ELEMENT group (href?)>

5.3.  DAV:supported-privilege-set

   This is a protected property that identifies the ACL method, privileges defined
   for the server may reject resource.

   <!ELEMENT supported-privilege-set (supported-privilege*)>

   Each privilege appears as an XML element, where aggregate privileges
   list as sub-elements all of the privileges that they aggregate.

   <!ELEMENT supported-privilege
    (privilege, abstract?, description, supported-privilege*)>
   <!ELEMENT privilege ANY>

   An abstract privilege MUST NOT be used in an ACE for that resource.
   Servers MUST fail an attempt to set the ACL as specified.  The following properties an abstract privilege.

   <!ELEMENT abstract EMPTY>

   A description is a human-readable description of what this privilege
   controls access to.  Servers MUST indicate the restrictions human language of the
   description using the xml:lang attribute and SHOULD consider the HTTP
   Accept-Language request header when selecting one of multiple
   available languages.

   <!ELEMENT description #PCDATA>

   It is envisioned that a WebDAV ACL-aware administrative client must observe before setting would
   list the supported privileges in a dialog box, and allow the user to
   choose non-abstract privileges to apply in an
   ACL:






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   tree is useful programmatically to map well-known privileges (defined
   by WebDAV Access Control Protocol        December 2003


   <grant-only> Deny ACEs are not supported

   <no-invert> Inverted ACEs or other standards groups) into privileges that are not
   supported

   <deny-before-grant> All deny ACEs must occur before by any grant ACEs

   <required-principal> Indicates which principals are required particular server implementation.  The privilege
   tree also serves to hide complexity in implementations allowing large
   number of privileges to be
      present


   <!ELEMENT acl-restrictions (grant-only?, no-invert?,
                               deny-before-grant?,
                               required-principal?)>


5.6.1 DAV:grant-only

   This element indicates that ACEs with deny clauses are not allowed.

   <!ELEMENT grant-only EMPTY>


5.6.2 DAV:no-invert ACE Constraint

   This element indicates that ACEs with the <invert> element are not
   allowed.

   <!ELEMENT no-invert EMPTY>


5.6.3 DAV:deny-before-grant

   This element indicates that all deny ACEs must precede all grant
   ACEs.

   <!ELEMENT deny-before-grant EMPTY>


5.6.4 Required Principals

   The required principal elements identify which principals must have
   an ACE defined in the ACL.

   <!ELEMENT required-principal
     (all? | authenticated? | unauthenticated? | self? | href* |
      property*)>

   For example, the following element requires that by displaying aggregates to the ACL contain a
   user.



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   DAV:owner property ACE:

   <D:required-principal xmlns:D="DAV:">
     <D:property><D:owner/></D:property>
   </D:required-principal>


5.6.5             May 2004


5.3.1.  Example: Retrieving DAV:acl-restrictions

   In this example, the a List of Privileges Supported on a Resource

   This example shows a client requests request for the DAV:supported-privilege-
   set property on the resource http://www.example.com/papers/.  The
   value of the
   DAV:acl-restrictions property. Digest authentication provides
   credentials for the principal operating DAV:supported-privilege-set property is a tree of
   supported privileges (using "[XML Namespace , localname]" to identify
   each privilege):

   [DAV:, all] (aggregate, abstract)
      |
      +-- [DAV:, read] (aggregate)
             |
             +-- [DAV:, read-acl] (abstract)
             +-- [DAV:, read-current-user-privilege-set] (abstract)
      |
      +-- [DAV:, write] (aggregate)
             |
             +-- [DAV:, write-acl] (abstract)
             +-- [DAV:, write-properties]
             +-- [DAV:, write-content]
      |
      +-- [DAV:, unlock]

   This privilege tree is not normative (except that it reflects the client.
   normative aggregation rules given in Section 3.12), and many possible
   privilege trees are possible.

   >> Request <<

   PROPFIND /papers/ HTTP/1.1
   Host: www.example.com
   Content-type: text/xml; charset="utf-8"
   Content-Length: xxx
   Depth: 0
   Authorization: Digest username="srcarter", username="gclemm",
     realm="users@example.com", nonce="...",
     uri="/papers/", response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:propfind xmlns:D="DAV:">
     <D:prop>
       <D:acl-restrictions/>
       <D:supported-privilege-set/>
     </D:prop>
   </D:propfind>







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   >> Response <<

   HTTP/1.1 207 Multi-Status

   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:">
     <D:response>
       <D:href>http://www.example.com/papers/</D:href>
       <D:propstat>
         <D:prop>
           <D:acl-restrictions>
             <D:grant-only/>
             <D:required-principal>
               <D:all/>
             </D:required-principal>
           </D:acl-restrictions>
           <D:supported-privilege-set>
             <D:supported-privilege>
               <D:privilege><D:all/></D:privilege>
              <D:abstract/>
               <D:description xml:lang="en">
                 Any operation
               </D:description>
               <D:supported-privilege>
                 <D:privilege><D:read/></D:privilege>
                 <D:description xml:lang="en">
                   Read any object
                 </D:description>
                 <D:supported-privilege>
                   <D:privilege><D:read-acl/></D:privilege>
                   <D:abstract/>
                   <D:description xml:lang="en">Read ACL</D:description>
                 </D:supported-privilege>
                 <D:supported-privilege>
                   <D:privilege>
                     <D:read-current-user-privilege-set/>
                   </D:privilege>
                   <D:abstract/>
                   <D:description xml:lang="en">
                     Read current user privilege set property
                   </D:description>
                 </D:supported-privilege>
               </D:supported-privilege>
               <D:supported-privilege>
                 <D:privilege><D:write/></D:privilege>
                 <D:description xml:lang="en">
                   Write any object
                 </D:description>
                 <D:supported-privilege>
                   <D:privilege><D:write-acl/></D:privilege>
                   <D:description xml:lang="en">



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                     Write ACL
                   </D:description>
                   <D:abstract/>
                 </D:supported-privilege>
                 <D:supported-privilege>
                   <D:privilege><D:write-properties/></D:privilege>
                   <D:description xml:lang="en">
                     Write properties
                   </D:description>
                 </D:supported-privilege>
                 <D:supported-privilege>
                   <D:privilege><D:write-content/></D:privilege>
                   <D:description xml:lang="en">
                     Write resource content
                   </D:description>
                 </D:supported-privilege>
               </D:supported-privilege>
               <D:supported-privilege>
                 <D:privilege><D:unlock/></D:privilege>
                 <D:description xml:lang="en">
                   Unlock resource
                 </D:description>
               </D:supported-privilege>
             </D:supported-privilege>
           </D:supported-privilege-set>
         </D:prop>
         <D:status>HTTP/1.1 200 OK</D:status>
       </D:propstat>
     </D:response>
   </D:multistatus>


5.7 DAV:inherited-acl-set

   This protected property contains a set of URLs that identify other
   resources that also control the access to this resource.  To have a
   privilege on

5.4.  DAV:current-user-privilege-set

   DAV:current-user-privilege-set is a resource, not only must the ACL on that resource
   (specified in the DAV:acl property of that resource) grant the
   privilege, but so must the ACL of each resource identified in the
   DAV:inherited-acl-set property of that resource.  Effectively, the
   privileges granted by the current ACL are ANDed with the privileges
   granted by each inherited ACL.

   <!ELEMENT inherited-acl-set (href*)>


5.8 DAV:principal-collection-set

   This protected property of a resource contains a containing the
   exact set of URLs that
   identify of privileges (as computed by the root collections that contain server) granted to the principals that
   currently authenticated HTTP user.  Aggregate privileges and their
   contained privileges are
   available on the server that implements this resource. listed.  A WebDAV
   Access Control Protocol user agent could user-agent can use the contents value of
   DAV:principal-collection-set
   this property to retrieve adjust its user interface to make actions
   inaccessible (e.g., by graying out a menu item or button) for which
   the DAV:displayname current principal does not have permission.  This property
   (specified in Section 13.2 of [RFC2518]) of all principals on that
   server, thereby yielding human-readable names is
   also useful for each determining what operations the current principal that can
   perform, without having to actually execute an operation.

   <!ELEMENT current-user-privilege-set (privilege*)>
   <!ELEMENT privilege ANY>






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   could be displayed in a user interface.

   <!ELEMENT principal-collection-set (href*)>

   Since different servers can control different parts of the URL
   namespace, different resources on the same host MAY have different
   DAV:principal-collection-set values. The collections specified in the
   DAV:principal-collection-set MAY be located on different hosts from
   the resource. The URLs in DAV:principal-collection-set SHOULD be http
   or https scheme URLs. For security and scalability reasons, a server
   MAY report only a subset of the entire set of known principal
   collections, and therefore clients should not assume they have
   retrieved an exhaustive listing. Additionally, a server MAY elect to
   report none of the principal collections it knows about, in which
   case the property value would be empty.

   The value of DAV:principal-collection-set gives the scope of the
   DAV:principal-property-search REPORT (defined in Section 9.4).
   Clients use             May 2004


   If the DAV:principal-property-search REPORT to populate
   their current user interface with is granted a list of principals. Therefore, servers specific privilege, that limit a client's ability to obtain principal information will
   interfere with the client's ability to manipulate access control
   lists, due privilege
   must belong to the difficulty set of getting privileges that may be set on this
   resource.  Therefore, each element in the URL of DAV:current-user-
   privilege-set property MUST identify a principal for
   use in an ACE.

5.8.1 non-abstract privilege from
   the DAV:supported-privilege-set property.

5.4.1.  Example: Retrieving DAV:principal-collection-set

   In this example, the client requests the value User's Current Set of Assigned
        Privileges

   Continuing the
   DAV:principal-collection-set example from Section 5.3.1, this example shows a
   client requesting the DAV:current-user-privilege-set property on from
   the collection resource
   identified by with URL http://www.example.com/papers/.  The property
   contains the two URLs, http://www.example.com/acl/users/ and http://
   www.example.com/acl/groups/, both wrapped in DAV:href XML elements.
   Digest authentication provides credentials for username
   of the principal
   operating making the client.

   The client might reasonably follow this request with two separate
   PROPFIND requests to retrieve the DAV:displayname property of the
   members of the two collections (/acl/users is "khare", and /acl/groups). This
   information could be used when displaying a user interface for
   creating access control entries.











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   >> Request <<

   PROPFIND /papers/ HTTP/1.1
   Host: www.example.com
   Content-type: text/xml; charset="utf-8"
   Content-Length: xxx
   Depth: 0
   Authorization: Digest username="yarong",
     realm="users@example.com", nonce="...",
     uri="/papers/", response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:propfind xmlns:D="DAV:">
     <D:prop>
       <D:principal-collection-set/>
     </D:prop>
   </D:propfind>

   >> Response <<

   HTTP/1.1 207 Multi-Status
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:">
     <D:response>
       <D:href>http://www.example.com/papers/</D:href>
       <D:propstat>
         <D:prop>
           <D:principal-collection-set>
             <D:href>http://www.example.com/acl/users/</D:href>
             <D:href>http://www.example.com/acl/groups/</D:href>
           </D:principal-collection-set>
         </D:prop>
       <D:status>HTTP/1.1 200 OK</D:status>
       </D:propstat>
     </D:response>
   </D:multistatus>


5.9 Example: PROPFIND to retrieve access control properties Digest
   authentication is used in the request.  The following example shows how access control information principal with username
   "khare" has been granted the DAV:read privilege.  Since the DAV:read
   privilege contains the DAV:read-acl and DAV:read-current-user-
   privilege-set privileges (see Section 5.3.1), the principal with
   username "khare" can be
   retrieved by using read the PROPFIND method to fetch ACL property, and the values of DAV:current-
   user-privilege-set property.  However, the
   DAV:owner, DAV:supported-privilege-set,
   DAV:current-user-privilege-set, DAV:all, DAV:read-acl,
   DAV:write-acl and DAV:acl properties.




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   not listed in the value of DAV:current-user-privilege-set, since (for
   this example) they are abstract privileges.  DAV:write is not listed
   since the principal with username "khare" is not listed in an ACE
   granting that principal write permission.

   >> Request <<

   PROPFIND /top/container/ /papers/ HTTP/1.1
   Host: www.example.com
   Content-type: text/xml; charset="utf-8"
   Content-Length: xxx
   Depth: 0
   Authorization: Digest username="ejw", username="khare",
     realm="users@example.com", nonce="...",
     uri="/top/container/", response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:propfind xmlns:D="DAV:">
     <D:prop>
       <D:owner/>
       <D:supported-privilege-set/>
       <D:current-user-privilege-set/>
       <D:acl/>
     </D:prop>
   </D:propfind>

   >> Response <<

   HTTP/1.1 207 Multi-Status
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:"
                  xmlns:A="http://www.example.com/acl/">
     <D:response>
       <D:href>http://www.example.com/top/container/</D:href>
       <D:propstat>
         <D:prop>
           <D:owner>
             <D:href>http://www.example.com/users/gclemm</D:href>
           </D:owner>
           <D:supported-privilege-set>
             <D:supported-privilege>
               <D:privilege><D:all/></D:privilege>
               <D:abstract/>
               <D:description xml:lang="en">
                 Any operation
               </D:description>
               <D:supported-privilege>
                 <D:privilege><D:read/></D:privilege>
                 <D:description xml:lang="en">
                   Read any object



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                 </D:description>
               </D:supported-privilege>
               <D:supported-privilege>
                 <D:privilege><D:write/></D:privilege>
                 <D:abstract/>
                 <D:description xml:lang="en">
                   Write any object
                 </D:description>
                 <D:supported-privilege>
                   <D:privilege><A:create/></D:privilege>
                   <D:description xml:lang="en">
                     Create an object
                   </D:description>
                 </D:supported-privilege>
                 <D:supported-privilege>
                   <D:privilege><A:update/></D:privilege>
                   <D:description xml:lang="en">
                     Update an object
                   </D:description>
                 </D:supported-privilege>
               </D:supported-privilege>
               <D:supported-privilege>
                 <D:privilege><A:delete/></D:privilege>
                 <D:description xml:lang="en">
                   Delete an object
                 </D:description>
               </D:supported-privilege>
               <D:supported-privilege>
                 <D:privilege><D:read-acl/></D:privilege>
                 <D:description xml:lang="en">
                   Read the ACL
                 </D:description>
               </D:supported-privilege>
               <D:supported-privilege>
                 <D:privilege><D:write-acl/></D:privilege>
                 <D:description xml:lang="en">
                   Write the ACL
                 </D:description>
               </D:supported-privilege>
             </D:supported-privilege>
           </D:supported-privilege-set>
           <D:current-user-privilege-set>
             <D:privilege><D:read/></D:privilege>
             <D:privilege><D:read-acl/></D:privilege>
           </D:current-user-privilege-set>
           <D:acl>
             <D:ace>
               <D:principal> nonce="...",
     uri="/papers/", response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:propfind xmlns:D="DAV:">
     <D:prop>
       <D:current-user-privilege-set/>
     </D:prop>
   </D:propfind>









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                 <D:href>http://www.example.com/users/esedlar</D:href>
               </D:principal>
               <D:grant>
                 <D:privilege><D:read/></D:privilege>
                 <D:privilege><D:write/></D:privilege>
                 <D:privilege><D:read-acl/></D:privilege>
               </D:grant>
             </D:ace>
             <D:ace>
               <D:principal>
                 <D:href>http://www.example.com/groups/marketing</D:href>
               </D:principal>
               <D:deny>
                 <D:privilege><D:read/></D:privilege>
               </D:deny>
             </D:ace>
             <D:ace>
               <D:principal>
                 <D:property><D:owner/></D:property>
               </D:principal>
               <D:grant>
                 <D:privilege><D:read-acl/></D:privilege>
                 <D:privilege><D:write-acl/></D:privilege>
               </D:grant>
             </D:ace>
             <D:ace>
               <D:principal><D:all/></D:principal>
               <D:grant>             May 2004


   >> Response <<

   HTTP/1.1 207 Multi-Status
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:">
     <D:response>
     <D:href>http://www.example.com/papers/</D:href>
     <D:propstat>
       <D:prop>
         <D:current-user-privilege-set>
           <D:privilege><D:read/></D:privilege>
               </D:grant>
               <D:inherited>
                 <D:href>http://www.example.com/top</D:href>
               </D:inherited>
             </D:ace>
           </D:acl>
         </D:current-user-privilege-set>
       </D:prop>
       <D:status>HTTP/1.1 200 OK</D:status>
     </D:propstat>
     </D:response>
   </D:multistatus>

5.5.  DAV:acl

   This is a protected property that specifies the list of access
   control entries (ACEs), which define what principals are to get what
   privileges for this resource.

   <!ELEMENT acl (ace*) >

   Each DAV:ace element specifies the set of privileges to be either
   granted or denied to a single principal.  If the DAV:acl property is
   empty, no principal is granted any privilege.

   <!ELEMENT ace ((principal | invert), (grant|deny), protected?,
                  inherited?)>

5.5.1.  ACE Principal

   The DAV:principal element identifies the principal to which this ACE
   applies.

   <!ELEMENT principal (href | all | authenticated | unauthenticated
    | property | self)>

   The current user matches DAV:href only if that user is authenticated
   as being (or being a member of) the principal identified by the URL
   contained by that DAV:href.




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   The current user always matches DAV:all.

   <!ELEMENT all EMPTY>

   The current user matches DAV:authenticated only if authenticated.

   <!ELEMENT authenticated EMPTY>

   The current user matches DAV:unauthenticated only if not
   authenticated.

   <!ELEMENT unauthenticated EMPTY>

   DAV:all is the union of DAV:authenticated, and DAV:unauthenticated.
   For a given request, the user matches either DAV:authenticated, or
   DAV:unauthenticated, but not both (that is, DAV:authenticated and
   DAV:unauthenticated are disjoint sets).

   The current user matches a DAV:property principal in a DAV:acl
   property of a resource only if the value of the DAV:owner identified property is a single
   of that resource contains at most one DAV:href XML element
   containing element, the URL URI
   value of DAV:href identifies a principal, and the principal current user is
   authenticated as being (or being a member of) that owns this principal.  For
   example, if the DAV:property element contained <DAV:owner/>, the
   current user would match the DAV:property principal only if the
   current user is authenticated as matching the principal identified by
   the DAV:owner property of the resource.

   <!ELEMENT property ANY>

   The value current user matches DAV:self in a DAV:acl property of the DAV:supported-privilege-set property
   resource only if that resource is a tree principal and that principal
   matches the current user or, if the principal is a group, a member of
   supported privileges (using "[XML Namespace , localname]"
   that group matches the current user.

   <!ELEMENT self EMPTY>

   Some servers may support ACEs applying to identify
   each privilege): those users NOT matching
   the current principal, e.g., all users not in a particular group.
   This can be done by wrapping the DAV:principal element with
   DAV:invert.

   <!ELEMENT invert principal>








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   [DAV:, all] (aggregate, abstract)
      |
      +-- [DAV:, read]
      +-- [DAV:, write] (aggregate, abstract)
             |
             +-- [http://www.example.com/acl, create]
             +-- [http://www.example.com/acl, update]
             +-- [http://www.example.com/acl, delete]
      +-- [DAV:, read-acl]
      +-- [DAV:, write-acl]

   The DAV:current-user-privilege-set property contains two privileges,
   DAV:read,             May 2004


5.5.2.  ACE Grant and DAV:read-acl. This indicates that the current
   authenticated user only has Deny

   Each DAV:grant or DAV:deny element specifies the ability set of privileges to
   be either granted or denied to read the resource, and
   read the DAV:acl property on specified principal.  A DAV:grant
   or DAV:deny element of the resource. The DAV:acl property
   contains of a set resource MUST only contain
   non-abstract elements specified in the DAV:supported-privilege-set of four ACEs:
   that resource.

   <!ELEMENT grant (privilege+)>
   <!ELEMENT deny (privilege+)>
   <!ELEMENT privilege ANY>

5.5.3.  ACE #1: The principal identified by the URL http://www.example.com/
   users/esedlar is granted the DAV:read, DAV:write, and DAV:read-acl
   privileges. Protection

   A server indicates an ACE #2: The principals identified is protected by including the URL http://www.example.com/
   groups/marketing are denied DAV:protected
   element in the DAV:read privilege.  In this example, ACE.  If the principal URL identifies ACL of a group. resource contains an ACE #3: In this ACE, the principal is with a property principal,
   specifically the DAV:owner property. When evaluating this ACE,
   DAV:protected element, an attempt to remove that ACE from the
   value ACL
   MUST fail.

   <!ELEMENT protected EMPTY>

5.5.4.  ACE Inheritance

   The presence of the DAV:owner property a DAV:inherited element indicates that this ACE is retrieved, and
   inherited from another resource that is examined to see
   if it contains identified by the URL
   contained in a DAV:href XML element. If so, the URL within  An inherited ACE cannot be modified
   directly, but instead the
   DAV:href element is read, and identifies a principal. In this ACE, ACL on the owner resource from which it is granted DAV:read-acl, and DAV:write-acl privileges.

   ACE #4: This
   inherited must be modified.

   Note that ACE grants inheritance is not the DAV:all principal (all users) same as ACL initialization.  ACL
   initialization defines the
   DAV:read privilege. This ACL that a newly created resource will use
   (if not specified).  ACE inheritance refers to an ACE that is inherited from
   logically shared - where an update to the resource http://
   www.example.com/top, containing an ACE
   will affect the parent collection ACE of this resource.

6. ACL Evaluation

   WebDAV each resource that inherits that ACE.  The
   method by which ACLs are evaluated in similar manner as ACLs on Windows NT and
   in NFSv4 [RFC3530]).  An ACL is evaluated to determine whether initialized or not
   access will be granted for a WebDAV request. by which ACEs are maintained in
   a particular order, and are evaluated until all of the permissions
   required inherited
   is not defined by this document.

   <!ELEMENT inherited (href)>

5.5.5.  Example: Retrieving a Resource's Access Control List

   Continuing the current request have been granted, at which point the
   ACL evaluation is terminated example from Sections 5.3.1 and access is granted.  If, during ACL
   evaluation, 5.4.1, this example
   shows a <deny> ACE (matching client requesting the current user) is encountered
   for a privilege which has not yet been granted, DAV:acl property from the ACL evaluation is
   terminated and access is denied.  Failure to have all required
   privileges granted results resource with
   URL http://www.example.com/papers/.  There are two ACEs defined in access being denied.
   this ACL:






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   Note that the semantics             May 2004


   ACE #1: The group identified by URL http://www.example.com/acl/
   groups/maintainers (the group of many other existing ACL systems may be
   represented via site maintainers) is granted
   DAV:write privilege.  Since (for this mechanism, by mixing deny and grant ACEs. For
   example, consider example) DAV:write contains the standard "rwx"
   DAV:write-acl privilege scheme used by UNIX.
   In (see Section 5.3.1), this scheme, if the current user is means the owner of
   "maintainers" group can also modify the file, access
   is control list.

   ACE #2: All principals (DAV:all) are granted if the corresponding privilege bit is set DAV:read privilege.
   Since (for this example) DAV:read contains DAV:read-acl and denied if
   not set, regardless
   DAV:read-current-user-privilege-set, this means all users (including
   all members of the permissions set on "maintainers" group) can read the file's group DAV:acl property
   and
   for the world.  An ACL for UNIX permissions of "r--rw-r--" might be
   constructed like: DAV:current-user-privilege-set property.

   >> Request <<

   PROPFIND /papers/ HTTP/1.1
   Host: www.example.com
   Content-type: text/xml; charset="utf-8"
   Content-Length: xxx
   Depth: 0
   Authorization: Digest username="masinter",
     realm="users@example.com", nonce="...",
     uri="/papers/", response="...", opaque="..."

   <D:propfind xmlns:D="DAV:">
     <D:prop>
       <D:acl/>
     </D:prop>
   </D:propfind>

   >> Response <<

   HTTP/1.1 207 Multi-Status
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <D:multistatus xmlns:D="DAV:">
     <D:response>
       <D:href>http://www.example.com/papers/</D:href>
       <D:propstat>
         <D:prop>
           <D:acl>
           <D:ace>
             <D:principal>
         <D:property><D:owner/></D:property>
       </D:principal>
       <D:grant>
         <D:privilege><D:read/></D:privilege>
       </D:grant>
     </D:ace>
     <D:ace>
       <D:principal>
         <D:property><D:owner/></D:property>
       </D:principal>
       <D:deny>
         <D:privilege><D:all/></D:privilege>
       </D:deny>
     </D:ace>
     <D:ace>
       <D:principal>
         <D:property><D:group/></D:property>
               <D:href
               >http://www.example.com/acl/groups/maintainers</D:href>
             </D:principal>
             <D:grant>
         <D:privilege><D:read/></D:privilege>
               <D:privilege><D:write/></D:privilege>
       </D:grant>
     </D:ace>
     <D:ace>
       <D:principal>
         <D:property><D:group/></D:property>
       </D:principal>
       <D:deny>
         <D:privilege><D:all/></D:privilege>
       </D:deny>
     </D:ace>
     <D:ace>
       <D:principal><D:all></D:principal>
       <D:grant>
         <D:privilege><D:read/></D:privilege>
       </D:grant>



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             </D:grant>
           </D:ace>
   </D:acl>

   and the <acl-restrictions> would be defined as:

   <D:no-invert/>
   <D:required-principal>
           <D:ace>
             <D:principal>
               <D:all/>
     <D:property><D:owner/></D:property>
     <D:property><D:group/><D:group/>
   </D:required-principal>

   Note that the client can still get errors from a UNIX server in spite
   of obeying the <acl-restrictions>, including <D:allowed-principal>
   (adding an ACE specifying a principal other than the ones in the ACL
   above) or <D:ace-conflict> (by trying to reorder the ACEs in the
   example above), as these particular implementation semantics are too
   complex to be captured with the simple (but general) declarative
   restrictions.

7. Access Control and existing methods
             </D:principal>
             <D:grant>
               <D:privilege><D:read/></D:privilege>
             </D:grant>
           </D:ace>
         </D:acl>
         </D:prop>
         <D:status>HTTP/1.1 200 OK</D:status>
       </D:propstat>
     </D:response>
   </D:multistatus>

5.6.  DAV:acl-restrictions

   This section protected property defines the impact types of access control functionality on
   existing methods.

7.1 Any HTTP method

7.1.1 Error Handling

   The WebDAV ACLs supported by this
   server, to avoid clients needlessly getting errors.  When a client
   tries to set an ACL mechanism requires via the usage of HTTP method
   "preconditions" as described in section 1.6 of RFC3253 for ALL HTTP
   methods.  All HTTP methods have an additional precondition called
   DAV:need-privileges.  If an HTTP method fails due to insufficient
   privileges, ACL method, the response body server may reject the
   attempt to set the "403 Forbidden" error MUST
   contain ACL as specified.  The following properties
   indicate the <DAV:error> element, which in turn contains restrictions the
   <DAV:need-privileges> element, which contains one or more
   <DAV:resource> elements indicating client must observe before setting an
   ACL:

   <grant-only> Deny ACEs are not supported

   <no-invert> Inverted ACEs are not supported

   <deny-before-grant> All deny ACEs must occur before any grant ACEs

   <required-principal> Indicates which resource had insufficient
   privileges, and what the lacking privileges were: principals are required to be
      present


   <!ELEMENT need-privileges (resource)* > acl-restrictions (grant-only?, no-invert?,
                               deny-before-grant?,
                               required-principal?)>

5.6.1.  DAV:grant-only

   This element indicates that ACEs with deny clauses are not allowed.

   <!ELEMENT resource ( href , privilege ) >

   Since some methods require multiple permissions on multiple
   resources, this information is needed to resolve any ambiguity. There
   is no requirement grant-only EMPTY>






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5.6.2.  DAV:no-invert ACE Constraint

   This element indicates that all privilege violations be reported - for
   implementation reasons, some servers may only report ACEs with the <invert> element are not
   allowed.

   <!ELEMENT no-invert EMPTY>

5.6.3.  DAV:deny-before-grant

   This element indicates that all deny ACEs must precede all grant
   ACEs.

   <!ELEMENT deny-before-grant EMPTY>

5.6.4.  Required Principals

   The required principal elements identify which principals must have
   an ACE defined in the first
   privilege violation. ACL.

   <!ELEMENT required-principal
     (all? | authenticated? | unauthenticated? | self? | href* |
      property*)>

   For example:




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   >> Request <<

   MOVE /a/b/ HTTP/1.1
   Host: www.example.com
   Destination: http://www.example.com/c/d

   >> Response <<

   HTTP/1.1 403 Forbidden
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <D:error xmlns:D="DAV:">
     <D:need-privileges>
       <D:resource>
         <D:href>/a</D:href>
         <D:privilege><D:unbind/></D:privilege>
       </D:resource>
       <D:resource>
         <D:href>/c</D:href>
         <D:privilege><D:bind/></D:privilege>
       </D:resource>
     </D:need-privileges>
   </D:error>


7.2 OPTIONS

   If example, the server supports access control, it MUST return
   "access-control" as following element requires that the ACL contain a field in

   DAV:owner property ACE:

   <D:required-principal xmlns:D="DAV:">
     <D:property><D:owner/></D:property>
   </D:required-principal>

5.6.5.  Example: Retrieving DAV:acl-restrictions

   In this example, the client requests the DAV response header from an
   OPTIONS request on any resource implemented by that server. A value of "access-control" in the DAV header MUST indicate that DAV:acl-
   restrictions property.  Digest authentication provides credentials
   for the server
   supports all MUST level requirements and REQUIRED features specified
   in this document.

7.2.1 Example - OPTIONS principal operating the client.

   >> Request <<

   OPTIONS /foo.html

   PROPFIND /papers/ HTTP/1.1
   Host: www.example.com
   Content-type: text/xml; charset="utf-8"
   Content-Length: xxx
   Depth: 0

   >> Response <<

   HTTP/1.1 200 OK
   DAV: 1, 2, access-control
   Allow: OPTIONS, GET, PUT, PROPFIND, PROPPATCH, ACL
   Authorization: Digest username="srcarter",
     realm="users@example.com", nonce="...",
     uri="/papers/", response="...", opaque="..."




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   In this example, the OPTIONS response indicates             May 2004


   <?xml version="1.0" encoding="utf-8" ?>
   <D:propfind xmlns:D="DAV:">
     <D:prop>
       <D:acl-restrictions/>
     </D:prop>
   </D:propfind>

   >> Response <<

   HTTP/1.1 207 Multi-Status
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:">
     <D:response>
       <D:href>http://www.example.com/papers/</D:href>
       <D:propstat>
         <D:prop>
           <D:acl-restrictions>
             <D:grant-only/>
             <D:required-principal>
               <D:all/>
             </D:required-principal>
           </D:acl-restrictions>
         </D:prop>
         <D:status>HTTP/1.1 200 OK</D:status>
       </D:propstat>
     </D:response>
   </D:multistatus>

5.7.  DAV:inherited-acl-set

   This protected property contains a set of URLs that the server
   supports access control and identify other
   resources that /foo.html can have its access also control list modified by the ACL method.

7.3 MOVE

   When a resource is moved from one location to another due access to this resource.  To have a MOVE
   request,
   privilege on a resource, not only must the non-inherited and non-protected ACEs ACL on that resource
   (specified in the DAV:acl property of that resource) grant the resource MUST NOT be modified, or
   privilege, but so must the MOVE request
   fails. Handling ACL of inherited and protected ACEs is intentionally
   undefined to give server implementations flexibility in how they
   implement ACE inheritance and protection.

7.4 COPY

   The DAV:acl property on the each resource at identified in the destination
   DAV:inherited-acl-set property of a COPY
   MUST be the same as if that resource.  Effectively, the resource was created
   privileges granted by an individual
   resource creation request (e.g. MKCOL, PUT). Clients wishing to
   preserve the DAV:acl property across a copy need to read the DAV:acl
   property prior to the COPY, then perform an current ACL operation on the new
   resource at the destination to restore, insofar as this is possible,
   the original access control list.

7.5 LOCK

   A lock on a resource ensures that only the lock owner can modify ACEs
   that are not inherited and not protected  (these are the only ACEs
   that a client can modify ANDed with an ACL request). A lock does not
   protect the privileges
   granted by each inherited or ACL.

   <!ELEMENT inherited-acl-set (href*)>








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5.8.  DAV:principal-collection-set

   This protected ACEs, since property of a client cannot modify
   them with an ACL request resource contains a set of URLs that
   identify the root collections that contain the principals that are
   available on the server that implements this resource.

8.  A WebDAV
   Access Control Methods

8.1 ACL

   The ACL method modifies the access control list (which can be read
   via Protocol user agent could use the DAV:acl property) contents of a resource.  Specifically, the ACL
   method only permits modification to ACEs that are not inherited, and
   are not protected. An ACL method invocation modifies all
   non-inherited and non-protected ACEs in a resource's access control
   list
   DAV:principal-collection-set to exactly match the ACEs contained within in retrieve the DAV:acl XML
   element DAV:displayname property
   (specified in Section 5.5) 13.2 of the request body. An ACL
   request body MUST contain only one DAV:acl XML element. Unless the
   non-inherited and non-protected ACEs [RFC2518]) of the DAV:acl property all principals on that
   server, thereby yielding human-readable names for each principal that
   could be displayed in a user interface.

   <!ELEMENT principal-collection-set (href*)>

   Since different servers can control different parts of the
   resource can be updated to be exactly URL
   namespace, different resources on the value same host MAY have different
   DAV:principal-collection-set values.  The collections specified in
   the ACL
   request, DAV:principal-collection-set MAY be located on different hosts
   from the ACL request MUST fail.

   It is possible that resource. The URLs in DAV:principal-collection-set SHOULD be
   http or https scheme URLs.  For security and scalability reasons, a
   server MAY report only a subset of the ACEs visible entire set of known principal
   collections, and therefore clients should not assume they have
   retrieved an exhaustive listing.  Additionally, a server MAY elect to
   report none of the current user principal collections it knows about, in which
   case the



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   DAV:acl property may only value would be a portion empty.

   The value of DAV:principal-collection-set gives the complete set scope of ACEs on
   that resource. If this is the case, an ACL request only modifies the
   set of ACEs visible to
   DAV:principal-property-search REPORT (defined in Section 9.4).
   Clients use the current user, and does not affect any
   non-visible ACE.

   In order DAV:principal-property-search REPORT to avoid overwriting DAV:acl changes by another client, a
   client SHOULD acquire populate
   their user interface with a WebDAV lock on the resource before retrieving
   the DAV:acl property list of a resource principals.  Therefore, servers
   that it intends on updating.

      Implementation Note: Two common operations are to add or remove an
      ACE from an existing access control list. To accomplish this, limit a
      client uses the PROPFIND method client's ability to retrieve the value of the
      DAV:acl property, then parses obtain principal information will
   interfere with the returned client's ability to manipulate access control list
   lists, due to
      remove all inherited and protected ACEs (these ACEs are tagged
      with the DAV:inherited and DAV:protected XML elements). In the
      remaining set of non-inherited, non-protected ACEs, the client can
      add or remove one or more ACEs before submitting the final ACE set
      in the request body of the ACL method.


8.1.1 ACL Preconditions

   An implementation MUST enforce the following constraints on an ACL
   request.  If the constraint is violated, a 403 (Forbidden) or 409
   (Conflict) response MUST be returned and the indicated XML element
   MUST be returned as a child difficulty of getting the URL of a top level DAV:error element principal for
   use in an
   XML response body.

   Though these status elements are generally expressed as empty XML
   elements (and are defined as EMPTY in ACE.

5.8.1.  Example: Retrieving DAV:principal-collection-set

   In this example, the DTD), implementations MAY
   return additional descriptive XML elements as children of client requests the status
   element. Clients MUST be able to accept children value of these status
   elements. Clients that do not understand the additional XML elements
   should ignore them.

   (DAV:no-ace-conflict): The ACEs submitted in DAV:principal-
   collection-set property on the ACL request MUST NOT
   conflict with each other.  This is a catchall error code indicating
   that an implementation-specific ACL restriction has been violated.

   (DAV:no-protected-ace-conflict): collection resource identified by URL
   http://www.example.com/papers/.  The ACEs submitted property contains the two URLs,
   http://www.example.com/acl/users/ and http://
   www.example.com/acl/groups/, both wrapped in DAV:href XML elements.
   Digest authentication provides credentials for the ACL principal
   operating the client.








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   The client might reasonably follow this request MUST NOT conflict with two separate
   PROPFIND requests to retrieve the protected ACEs on DAV:displayname property of the resource.
   For example, if
   members of the resource has two collections (/acl/users and /acl/groups).  This
   information could be used when displaying a protected ACE granting DAV:write user interface for
   creating access control entries.

   >> Request <<

   PROPFIND /papers/ HTTP/1.1
   Host: www.example.com
   Content-type: text/xml; charset="utf-8"
   Content-Length: xxx
   Depth: 0
   Authorization: Digest username="yarong",
     realm="users@example.com", nonce="...",
     uri="/papers/", response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:propfind xmlns:D="DAV:">
     <D:prop>
       <D:principal-collection-set/>
     </D:prop>
   </D:propfind>

   >> Response <<

   HTTP/1.1 207 Multi-Status
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:">
     <D:response>
       <D:href>http://www.example.com/papers/</D:href>
       <D:propstat>
         <D:prop>
           <D:principal-collection-set>
             <D:href>http://www.example.com/acl/users/</D:href>
             <D:href>http://www.example.com/acl/groups/</D:href>
           </D:principal-collection-set>
         </D:prop>
       <D:status>HTTP/1.1 200 OK</D:status>
       </D:propstat>
     </D:response>
   </D:multistatus>






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5.9.  Example: PROPFIND to a given principal, then it would not retrieve access control properties

   The following example shows how access control information can be consistent if
   retrieved by using the ACL
   request submitted an ACE denying DAV:write PROPFIND method to fetch the same principal.

   (DAV:no-inherited-ace-conflict): The ACEs submitted in the ACL
   request MUST NOT conflict with values of the inherited ACEs on
   DAV:owner, DAV:supported-privilege-set, DAV:current-user-privilege-
   set, and DAV:acl properties.

   >> Request <<

   PROPFIND /top/container/ HTTP/1.1
   Host: www.example.com
   Content-type: text/xml; charset="utf-8"
   Content-Length: xxx
   Depth: 0
   Authorization: Digest username="ejw",
     realm="users@example.com", nonce="...",
     uri="/top/container/", response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:propfind xmlns:D="DAV:">
     <D:prop>
       <D:owner/>
       <D:supported-privilege-set/>
       <D:current-user-privilege-set/>
       <D:acl/>
     </D:prop>
   </D:propfind>

   >> Response <<

   HTTP/1.1 207 Multi-Status
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:"
                  xmlns:A="http://www.example.com/acl/">
     <D:response>
       <D:href>http://www.example.com/top/container/</D:href>
       <D:propstat>
         <D:prop>
           <D:owner>
             <D:href>http://www.example.com/users/gclemm</D:href>
           </D:owner>
           <D:supported-privilege-set>
             <D:supported-privilege>
               <D:privilege><D:all/></D:privilege>
               <D:abstract/>



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               <D:description xml:lang="en">
                 Any operation
               </D:description>
               <D:supported-privilege>
                 <D:privilege><D:read/></D:privilege>
                 <D:description xml:lang="en">
                   Read any object
                 </D:description>
               </D:supported-privilege>
               <D:supported-privilege>
                 <D:privilege><D:write/></D:privilege>
                 <D:abstract/>
                 <D:description xml:lang="en">
                   Write any object
                 </D:description>
                 <D:supported-privilege>
                   <D:privilege><A:create/></D:privilege>
                   <D:description xml:lang="en">
                     Create an object
                   </D:description>
                 </D:supported-privilege>
                 <D:supported-privilege>
                   <D:privilege><A:update/></D:privilege>
                   <D:description xml:lang="en">
                     Update an object
                   </D:description>
                 </D:supported-privilege>
               </D:supported-privilege>
               <D:supported-privilege>
                 <D:privilege><A:delete/></D:privilege>
                 <D:description xml:lang="en">
                   Delete an object
                 </D:description>
               </D:supported-privilege>
               <D:supported-privilege>
                 <D:privilege><D:read-acl/></D:privilege>
                 <D:description xml:lang="en">
                   Read the resource.
   For example, if ACL
                 </D:description>
               </D:supported-privilege>
               <D:supported-privilege>
                 <D:privilege><D:write-acl/></D:privilege>
                 <D:description xml:lang="en">
                   Write the resource inherits an ACE from its parent ACL
                 </D:description>
               </D:supported-privilege>
             </D:supported-privilege>
           </D:supported-privilege-set>



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           <D:current-user-privilege-set>
             <D:privilege><D:read/></D:privilege>
             <D:privilege><D:read-acl/></D:privilege>
           </D:current-user-privilege-set>
           <D:acl>
             <D:ace>
               <D:principal>
                 <D:href>http://www.example.com/users/esedlar</D:href>
               </D:principal>
               <D:grant>
                 <D:privilege><D:read/></D:privilege>
                 <D:privilege><D:write/></D:privilege>
                 <D:privilege><D:read-acl/></D:privilege>
               </D:grant>
             </D:ace>
             <D:ace>
               <D:principal>
                 <D:href>http://www.example.com/groups/mrktng</D:href>
               </D:principal>
               <D:deny>
                 <D:privilege><D:read/></D:privilege>
               </D:deny>
             </D:ace>
             <D:ace>
               <D:principal>
                 <D:property><D:owner/></D:property>
               </D:principal>
               <D:grant>
                 <D:privilege><D:read-acl/></D:privilege>
                 <D:privilege><D:write-acl/></D:privilege>
               </D:grant>
             </D:ace>
             <D:ace>
               <D:principal><D:all/></D:principal>
               <D:grant>
                 <D:privilege><D:read/></D:privilege>
               </D:grant>
               <D:inherited>
                 <D:href>http://www.example.com/top</D:href>
               </D:inherited>
             </D:ace>
           </D:acl>
         </D:prop>
         <D:status>HTTP/1.1 200 OK</D:status>
       </D:propstat>
     </D:response>
   </D:multistatus>




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   collection granting DAV:write to             May 2004


   The value of the DAV:owner property is a given principal, then it would not
   be consistent if single DAV:href XML element
   containing the ACL request submitted an ACE denying DAV:write
   to URL of the same principal. Note principal that reporting of this error will be
   implementation-dependent. Implementations MUST either report owns this
   error or allow resource.

   The value of the ACE DAV:supported-privilege-set property is a tree of
   supported privileges (using "[XML Namespace , localname]" to be set, identify
   each privilege):

   [DAV:, all] (aggregate, abstract)
      |
      +-- [DAV:, read]
      +-- [DAV:, write] (aggregate, abstract)
             |
             +-- [http://www.example.com/acl, create]
             +-- [http://www.example.com/acl, update]
             +-- [http://www.example.com/acl, delete]
      +-- [DAV:, read-acl]
      +-- [DAV:, write-acl]

   The DAV:current-user-privilege-set property contains two privileges,
   DAV:read, and then let normal ACE evaluation
   rules determine whether DAV:read-acl.  This indicates that the new ACE current
   authenticated user only has any impact on the privileges
   available ability to a specific principal.

   (DAV:limited-number-of-aces): The number of ACEs submitted in read the ACL
   request MUST NOT exceed resource, and
   read the number of ACEs allowed DAV:acl property on that the resource.
   However, ACL-compliant servers MUST support at least one ACE granting
   privileges to  The DAV:acl property
   contains a single principal, set of four ACEs:

   ACE #1: The principal identified by the URL http://www.example.com/
   users/esedlar is granted the DAV:read, DAV:write, and one DAV:read-acl
   privileges.

   ACE granting privileges to #2: The principals identified by the URL http://www.example.com/
   groups/mrktng are denied the DAV:read privilege.  In this example,
   the principal URL identifies a group.

   (DAV:deny-before-grant): All non-inherited deny ACEs MUST precede all
   non-inherited grant ACEs.

   (DAV:grant-only): The ACEs submitted in

   ACE #3: In this ACE, the ACL request MUST NOT
   include principal is a deny ACE.  This precondition applies only when property principal,
   specifically the ACL
   restrictions of DAV:owner property.  When evaluating this ACE, the resource include
   value of the DAV:grant-only constraint
   (defined in Section 5.6.1).

   (DAV:no-invert):  The ACL request MUST NOT include DAV:owner property is retrieved, and is examined to see
   if it contains a DAV:invert DAV:href XML element.  If so, the URL within the
   DAV:href element is read, and identifies a principal.  In this ACE,
   the owner is granted DAV:read-acl, and DAV:write-acl privileges.

   ACE #4: This precondition applies only when ACE grants the ACL semantics of DAV:all principal (all users) the
   DAV:read privilege.  This ACE is inherited from the resource includes http://
   www.example.com/top, the DAV:no-invert constraint (defined parent collection of this resource.









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6.  ACL Evaluation

   WebDAV ACLs are evaluated in
   Section 5.6.2).

   (DAV:no-abstract): The similar manner as ACLs on Windows NT and
   in NFSv4 [RFC3530]).  An ACL request MUST NOT attempt is evaluated to grant determine whether or deny
   an abstract privilege (see Section 5.3).

   (DAV:not-supported-privilege): The not
   access will be granted for a WebDAV request.  ACEs submitted are maintained in
   a particular order, and are evaluated until all of the ACL request
   MUST be supported permissions
   required by the resource.

   (DAV:missing-required-principal): The result of the ACL current request MUST have been granted, at least one ACE for each principal identified in a
   DAV:required-principal XML element in which point the
   ACL semantics of that
   resource (see Section 5.5).

   (DAV:recognized-principal): Every principal URL in the evaluation is terminated and access is granted.  If, during ACL request
   MUST identify
   evaluation, a principal resource.

   (DAV:allowed-principal): The principals specified in the ACEs
   submitted in <deny> ACE (matching the ACL request MUST be allowed as principals current user) is encountered
   for the
   resource. For example, a server where only authenticated principals
   can access resources would privilege which has not allow yet been granted, the DAV:all or
   DAV:unauthenticated principals ACL evaluation is
   terminated and access is denied.  Failure to be used have all required
   privileges granted results in an ACE, since these
   would allow unauthenticated access to resources.




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8.1.2 Example: being denied.

   Note that the semantics of many other existing ACL method

   In the following example, user "fielding", authenticated systems may be
   represented via this mechanism, by
   information in the Authorization header, grants mixing deny and grant ACEs.  For
   example, consider the principal
   identified standard "rwx" privilege scheme used by UNIX.
   In this scheme, if the URL http://www.example.com/users/esedlar  (i.e.,
   the current user "esedlar") read and write privileges, grants is the owner of the resource read-acl file, access
   is granted if the corresponding privilege bit is set and write-acl privileges, denied if
   not set, regardless of the permissions set on the file's group and grants everyone
   read privileges.

   >> Request <<
   for the world.  An ACL /top/container/ HTTP/1.1
   Host: www.example.com
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx
   Authorization: Digest username="fielding",
     realm="users@example.com", nonce="...",
     uri="/top/container/", response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:acl xmlns:D="DAV:"> for UNIX permissions of "r--rw-r--" might be
   constructed like:

   <D:acl>
     <D:ace>
       <D:principal>
         <D:href>http://www.example.com/users/esedlar</D:href>
         <D:property><D:owner/></D:property>
       </D:principal>
       <D:grant>
         <D:privilege><D:read/></D:privilege>
         <D:privilege><D:write/></D:privilege>
       </D:grant>
     </D:ace>
     <D:ace>
       <D:principal>
         <D:property><D:owner/></D:property>
       </D:principal>
       <D:grant>
         <D:privilege><D:read-acl/></D:privilege>
         <D:privilege><D:write-acl/></D:privilege>
       </D:grant>
       <D:deny>
         <D:privilege><D:all/></D:privilege>
       </D:deny>
     </D:ace>
     <D:ace>
       <D:principal><D:all/></D:principal>
       <D:principal>
         <D:property><D:group/></D:property>
       </D:principal>
       <D:grant>
         <D:privilege><D:read/></D:privilege>
         <D:privilege><D:write/></D:privilege>
       </D:grant>
     </D:ace>
   </D:acl>



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   >> Response <<

   HTTP/1.1 200 OK


8.1.3 Example: ACL method failure due to protected ACE conflict

   In the following request, user "fielding", authenticated by
   information in the Authorization header, attempts to deny the
   principal identified by the URL http://www.example.com/users/esedlar
   (i.e., the user "esedlar") write privileges. Prior to the request,
   the DAV:acl property on the resource contained a protected ACE (see
   Section 5.5.3) granting DAV:owner the DAV:read and DAV:write
   privileges. The principal identified by URL http://www.example.com/
   users/esedlar is the owner of the resource. The ACL method invocation
   fails because the submitted ACE conflicts with the protected ACE,
   thus violating the semantics of ACE protection.

   >> Request <<

   ACL /top/container/ HTTP/1.1
   Host: www.example.com
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx
   Authorization: Digest username="fielding",
     realm="users@example.com", nonce="...",
     uri="/top/container/", response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:acl xmlns:D="DAV:">             May 2004


     <D:ace>
       <D:principal>
         <D:href>http://www.example.com/users/esedlar</D:href>
         <D:property><D:group/></D:property>
       </D:principal>
       <D:deny>
         <D:privilege><D:write/></D:privilege>
         <D:privilege><D:all/></D:privilege>
       </D:deny>
     </D:ace>
     <D:ace>
       <D:principal><D:all></D:principal>
       <D:grant>
         <D:privilege><D:read/></D:privilege>
       </D:grant>
     </D:ace>
   </D:acl>












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   >> Response <<

   HTTP/1.1 403 Forbidden
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:error xmlns:D="DAV:">
     <D:no-protected-ace-conflict/>
   </D:error>


8.1.4 Example: ACL method failure due to an inherited ACE conflict

   In the following request, user "ejw", authenticated by information in
   the Authorization header, tries to change the access control list on

   and the resource http://www.example.com/top/index.html. This resource has
   two inherited ACEs.

   Inherited ACE #1 grants <acl-restrictions> would be defined as:

   <D:no-invert/>
   <D:required-principal>
     <D:all/>
     <D:property><D:owner/></D:property>
     <D:property><D:group/><D:group/>
   </D:required-principal>

   Note that the principal identified by URL http://
   www.example.com/users/ejw (i.e., client can still get errors from a UNIX server in spite
   of obeying the user "ejw") http://
   www.example.com/privs/write-all and DAV:read-acl privileges. On this
   server, http://www.example.com/privs/write-all is <acl-restrictions>, including <D:allowed-principal>
   (adding an aggregate
   privilege containing DAV:write, and DAV:write-acl.

   Inherited ACE #2 grants specifying a principal DAV:all other than the DAV:read privilege.

   The request attempts ones in the ACL
   above) or <D:ace-conflict> (by trying to set a (non-inherited) ACE, denying reorder the
   principal identified by ACEs in the URL http://www.example.com/users/ejw
   (i.e.,
   example above), as these particular implementation semantics are too
   complex to be captured with the user "ejw") DAV:write permission. simple (but general) declarative
   restrictions.

7.  Access Control and existing methods

   This conflicts with
   inherited ACE #1. Note that section defines the decision to report impact of access control functionality on
   existing methods.

7.1.  Any HTTP method

7.1.1.  Error Handling

   The WebDAV ACL mechanism requires the usage of HTTP method
   "preconditions" as described in section 1.6 of RFC3253 for ALL HTTP
   methods.  All HTTP methods have an inherited ACE
   conflict is specific additional precondition called
   DAV:need-privileges.  If an HTTP method fails due to this server implementation. Another server
   implementation could have allowed insufficient
   privileges, the new ACE response body to be set, the "403 Forbidden" error MUST
   contain the <DAV:error> element, which in turn contains the



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   <DAV:need-privileges> element, which contains one or more
   <DAV:resource> elements indicating which resource had insufficient
   privileges, and then
   used normal ACE evaluation rules what the lacking privileges were:

   <!ELEMENT need-privileges (resource)* >
   <!ELEMENT resource ( href , privilege ) >

   Since some methods require multiple permissions on multiple
   resources, this information is needed to determine whether the new ACE has resolve any impact on ambiguity.
   There is no requirement that all privilege violations be reported -
   for implementation reasons, some servers may only report the privileges available to a principal.
















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   privilege violation.  For example:

   >> Request <<

   ACL /top/index.html

   MOVE /a/b/ HTTP/1.1
   Host: www.example.com
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx
   Authorization: Digest username="ejw",
     realm="users@example.com", nonce="...",
     uri="/top/index.html", response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:acl xmlns:D="DAV:" xmlns:F="http://www.example.com/privs/">
     <D:ace>
       <D:principal>
          <D:href>http://www.example.com/users/ejw</D:href>
       </D:principal>
       <D:grant><D:write/></D:grant>
     </D:ace>
   </D:acl>
   Destination: http://www.example.com/c/d

   >> Response <<

   HTTP/1.1 403 Forbidden
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <?xml version="1.0" encoding="utf-8" ?>

   <D:error xmlns:D="DAV:">
     <D:no-inherited-ace-conflict/>
     <D:need-privileges>
       <D:resource>
         <D:href>/a</D:href>
         <D:privilege><D:unbind/></D:privilege>
       </D:resource>
       <D:resource>
         <D:href>/c</D:href>
         <D:privilege><D:bind/></D:privilege>
       </D:resource>
     </D:need-privileges>
   </D:error>


8.1.5 Example: ACL method failure due to an attempt to set grant and
      deny in

7.2.  OPTIONS

   If the server supports access control, it MUST return "access-
   control" as a single ACE

   In this example, user "ygoland", authenticated by information field in the
   Authorization header, tries to change the access control list DAV response header from an OPTIONS
   request on the any resource http://www.example.com/diamond/engagement-ring.gif. The ACL
   request includes a single, syntactically and semantically incorrect
   ACE, which attempts to grant the group identified implemented by that server.  A value of
   "access-control" in the URL http://
   www.example.com/users/friends DAV:read privilege and deny the
   principal identified by URL http://www.example.com/users/ygoland-so
   (i.e., DAV header MUST indicate that the user "ygoland-so") DAV:read privilege. However, it is
   illegal to have multiple principal elements, as well as both a grant server
   supports all MUST level requirements and deny element REQUIRED features specified
   in the same ACE, so the request fails due to poor
   syntax. this document.





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7.2.1.  Example - OPTIONS

   >> Request <<

   ACL /diamond/engagement-ring.gif

   OPTIONS /foo.html HTTP/1.1
   Host: www.example.com
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx
   Authorization: Digest username="ygoland",
     realm="users@example.com", nonce="...",
     uri="/diamond/engagement-ring.gif", response="...",
     opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:acl xmlns:D="DAV:">
     <D:ace>
       <D:principal>
         <D:href>http://www.example.com/users/friends</D:href>
       </D:principal>
       <D:grant><D:read/></D:grant>
       <D:principal>
         <D:href>http://www.example.com/users/ygoland-so</D:href>
       </D:principal>
       <D:deny><D:read/></D:deny>
     </D:ace>
   </D:acl> 0

   >> Response <<

   HTTP/1.1 400 Bad Request
   Content-Length: 0

   Note 200 OK
   DAV: 1, 2, access-control
   Allow: OPTIONS, GET, PUT, PROPFIND, PROPPATCH, ACL

   In this example, the OPTIONS response indicates that if the request had been divided into two ACEs, one to
   grant, server
   supports access control and that /foo.html can have its access
   control list modified by the ACL method.

7.3.  MOVE

   When a resource is moved from one location to another due to deny, the request would have been syntactically
   well formed.

9. Access Control Reports

9.1 REPORT Method

   The REPORT method (defined in Section 3.6 of [RFC3253]) provides an
   extensible mechanism for obtaining information about a resource.
   Unlike MOVE
   request, the PROPFIND method, which returns non-inherited and non-protected ACEs in the value DAV:acl
   property of one the resource MUST NOT be modified, or more
   named properties, the REPORT method can involve more complex
   processing. REPORT MOVE request
   fails.  Handling of inherited and protected ACEs is valuable intentionally
   undefined to give server implementations flexibility in cases where how they
   implement ACE inheritance and protection.

7.4.  COPY

   The DAV:acl property on the server has access
   to all resource at the destination of a COPY
   MUST be the information needed same as if the resource was created by an individual
   resource creation request (e.g., MKCOL, PUT).  Clients wishing to
   preserve the DAV:acl property across a copy need to read the DAV:acl
   property prior to the COPY, then perform an ACL operation on the complex request (such new
   resource at the destination to restore, insofar as this is possible,
   the original access control list.

7.5.  LOCK

   A lock on a query), resource ensures that only the lock owner can modify ACEs
   that are not inherited and where it would require multiple requests for not protected  (these are the only ACEs
   that a client to retrieve the information needed to perform the same
   request. can modify with an ACL request).  A lock does not
   protect inherited or protected ACEs, since a client cannot modify
   them with an ACL request on that resource.







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   A server that supports the WebDAV             May 2004


8.  Access Control Protocol MUST
   support the DAV:expand-property report (defined in Section 3.8 of
   [RFC3253]).

9.2 DAV:acl-principal-prop-set Report Methods

8.1.  ACL

   The DAV:acl-principal-prop-set report returns, for all principals in
   the DAV:acl property (of ACL method modifies the Request-URI) that are identified by
   http(s) URLs or by a DAV:property principal, access control list (which can be read
   via the value DAV:acl property) of the
   properties specified in the REPORT request body. In the case where a
   principal URL appears multiple times, the DAV:acl-principal-prop-set
   report MUST return resource.  Specifically, the properties for that principal ACL
   method only once.
   Support for this report is REQUIRED.

   One expected use of this report is permits modification to retrieve the human readable
   name (found in the DAV:displayname property) of each principal found
   in an ACL. This is useful for constructing user interfaces ACEs that show
   each ACE are not inherited, and
   are not protected.  An ACL method invocation modifies all non-
   inherited and non-protected ACEs in a human readable form.

   Marshalling

      The resource's access control list
   to exactly match the ACEs contained within in the DAV:acl XML element
   (specified in Section 5.5) of the request body.  An ACL request body
   MUST be a DAV:acl-principal-prop-set contain only one DAV:acl XML element.

      <!ELEMENT acl-principal-prop-set ANY>
      ANY value: a sequence  Unless the non-inherited
   and non-protected ACEs of one or more elements, with at most one
                 DAV:prop element.
      prop: see RFC 2518, Section 12.11

      This report is only defined when the Depth header has value "0";
      other values result in a 400 (Bad Request) error response. Note
      that [RFC3253], Section 3.6, states that if DAV:acl property of the Depth header is
      not present, it defaults resource can be
   updated to a be exactly the value of "0".

      The response body for a successful specified in the ACL request, the ACL
   request MUST be a
      DAV:multistatus XML element (i.e., the response uses fail.

   It is possible that the same
      format as ACEs visible to the response for PROPFIND). In current user in the case where there are
      no response elements,
   DAV:acl property may only be a portion of the returned multistatus XML element complete set of ACEs on
   that resource.  If this is
      empty.

      multistatus: see RFC 2518, Section 12.9

      The response body for a successful DAV:acl-principal-prop-set
      REPORT the case, an ACL request MUST contain a DAV:response element for each
      principal identified only modifies the
   set of ACEs visible to the current user, and does not affect any
   non-visible ACE.

   In order to avoid overwriting DAV:acl changes by an http(s) URL listed in another client, a DAV:principal
      XML element of an ACE within
   client SHOULD acquire a WebDAV lock on the resource before retrieving
   the DAV:acl property of the a resource
      identified by that it intends on updating.

      Implementation Note: Two common operations are to add or remove an
      ACE from an existing access control list.  To accomplish this, a
      client uses the Request-URI.

   Postconditions:



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      (DAV:number-of-matches-within-limits): The number PROPFIND method to retrieve the value of matching
      principals must fall within server-specific, predefined limits.
      For example, this condition might be triggered if a search
      specification would cause the return
      DAV:acl property, then parses the returned access control list to
      remove all inherited and protected ACEs (these ACEs are tagged
      with the DAV:inherited and DAV:protected XML elements).  In the
      remaining set of an extremely large number non-inherited, non-protected ACEs, the client can
      add or remove one or more ACEs before submitting the final ACE set
      in the request body of responses.


9.2.1 Example: DAV:acl-principal-prop-set Report

   Resource http://www.example.com/index.html has the ACL method.

8.1.1.  ACL Preconditions

   An implementation MUST enforce the following constraints on an ACL with three
   ACEs:

   ACE #1: All principals (DAV:all) have DAV:read and
   DAV:read-current-user-privilege-set access.

   ACE #2: The principal identified by http://www.example.com/people/
   gstein (the user "gstein") is granted DAV:write,  DAV:write-acl,
   DAV:read-acl privileges.

   ACE #3: The group identified by http://www.example.com/groups/authors
   (the "authors" group)
   request.  If the constraint is granted DAV:write and DAV:read-acl
   privileges.

   The following example shows violated, a DAV:acl-principal-prop-set report
   requesting 403 (Forbidden) or 409
   (Conflict) response MUST be returned and the DAV:displayname property. It returns indicated XML element
   MUST be returned as a child of a top level DAV:error element in an
   XML response body.

   Though these status elements are generally expressed as empty XML
   elements (and are defined as EMPTY in the value DTD), implementations MAY
   return additional descriptive XML elements as children of
   DAV:displayname for resources http://www.example.com/people/gstein
   and http://www.example.com/groups/authors , but not for DAV:all,
   since this is not an http(s) URL.

   >> Request <<

   REPORT /index.html HTTP/1.1
   Host: www.example.com
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx
   Depth: 0

   <?xml version="1.0" encoding="utf-8" ?>
   <D:acl-principal-prop-set xmlns:D="DAV:">
     <D:prop>
       <D:displayname/>
     </D:prop>
   </D:acl-principal-prop-set> the status




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   >> Response <<

   HTTP/1.1 207 Multi-Status
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:">
     <D:response>
       <D:href>http://www.example.com/people/gstein</D:href>
       <D:propstat>
         <D:prop>
           <D:displayname>Greg Stein</D:displayname>
         </D:prop>
         <D:status>HTTP/1.1 200 OK</D:status>
       </D:propstat>
     </D:response>
     <D:response>
       <D:href>http://www.example.com/groups/authors</D:href>
       <D:propstat>
         <D:prop>
           <D:displayname>Site authors</D:displayname>
         </D:prop>
         <D:status>HTTP/1.1 200 OK</D:status>
       </D:propstat>
     </D:response>
   </D:multistatus>


9.3 DAV:principal-match REPORT

   The DAV:principal-match REPORT is used             May 2004


   element.  Clients MUST be able to identify all members (at
   any depth) accept children of these status
   elements.  Clients that do not understand the collection identified by additional XML elements
   should ignore them.

   (DAV:no-ace-conflict): The ACEs submitted in the Request-URI that are
   principals and ACL request MUST NOT
   conflict with each other.  This is a catchall error code indicating
   that match an implementation-specific ACL restriction has been violated.

   (DAV:no-protected-ace-conflict): The ACEs submitted in the current user. In particular, if ACL
   request MUST NOT conflict with the
   collection contains principals, protected ACEs on the report can resource.
   For example, if the resource has a protected ACE granting DAV:write
   to a given principal, then it would not be used consistent if the ACL
   request submitted an ACE denying DAV:write to identify
   all members of the collection that match same principal.

   (DAV:no-inherited-ace-conflict): The ACEs submitted in the ACL
   request MUST NOT conflict with the current user.
   Alternatively, inherited ACEs on the resource.
   For example, if the resource inherits an ACE from its parent
   collection contains resources that have a
   property that identifies granting DAV:write to a principal (e.g. DAV:owner), the report can given principal, then it would not
   be used consistent if the ACL request submitted an ACE denying DAV:write
   to identify all members of the collection whose property
   identifies a principal same principal.  Note that matches the current user. For example,
   this report can return all reporting of the resources in a collection hierarchy
   that are owned by the current user. Support for this report is
   REQUIRED.

   Marshalling:

      The request body error will be
   implementation-dependent.  Implementations MUST either report this
   error or allow the ACE to be set, and then let normal ACE evaluation
   rules determine whether the new ACE has any impact on the privileges
   available to a DAV:principal-match XML element.




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      <!ELEMENT principal-match ((principal-property | self), prop?)>
      <!ELEMENT principal-property ANY>
      ANY value: an element whose value identifies a property. specific principal.

   (DAV:limited-number-of-aces): The
      expectation is the value number of ACEs submitted in the named property typically contains
      an href element that contains ACL
   request MUST NOT exceed the URI number of ACEs allowed on that resource.
   However, ACL-compliant servers MUST support at least one ACE granting
   privileges to a principal
      <!ELEMENT self EMPTY>
      prop: see RFC 2518, Section 12.11 single principal, and one ACE granting privileges to
   a group.

   (DAV:deny-before-grant): All non-inherited deny ACEs MUST precede all
   non-inherited grant ACEs.

   (DAV:grant-only): The ACEs submitted in the ACL request MUST NOT
   include a deny ACE.  This report is precondition applies only defined when the Depth header has value "0";
      other values result ACL
   restrictions of the resource include the DAV:grant-only constraint
   (defined in a 400 (Bad Request) error response. Note
      that [RFC3253], Section 3.6, states that if the Depth header is
      not present, it defaults to a value of "0". 5.6.1).

   (DAV:no-invert):  The response body for
      a successful ACL request MUST be NOT include a DAV:multistatus XML DAV:invert
   element. In  This precondition applies only when the
      case where there are no response elements, ACL semantics of
   the returned
      multistatus XML element is empty.

      multistatus: see RFC 2518, resource includes the DAV:no-invert constraint (defined in
   Section 12.9 5.6.2).

   (DAV:no-abstract): The response body for a successful DAV:principal-match REPORT ACL request MUST contain a DAV:response element for each member of the
      collection that matches the current user. When the
      DAV:principal-property element is used, a match occurs if the
      current user is matched by NOT attempt to grant or deny
   an abstract privilege (see Section 5.3).





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   (DAV:not-supported-privilege): The ACEs submitted in the principal identified ACL request
   MUST be supported by the URI
      found in the DAV:href element resource.

   (DAV:missing-required-principal): The result of the property ACL request MUST
   have at least one ACE for each principal identified by the
      DAV:principal-property element. When the DAV:self element is used in a DAV:principal-match report issued against a group, it matches
      the group if a member identifies
   DAV:required-principal XML element in the same ACL semantics of that
   resource (see Section 5.5).

   (DAV:recognized-principal): Every principal as URL in the current
      user.

      If DAV:prop is ACL request
   MUST identify a principal resource.

   (DAV:allowed-principal): The principals specified in the request body, the properties
      specified ACEs
   submitted in the DAV:prop element ACL request MUST be reported in allowed as principals for the
      DAV:response elements.


9.3.1
   resource.  For example, a server where only authenticated principals
   can access resources would not allow the DAV:all or
   DAV:unauthenticated principals to be used in an ACE, since these
   would allow unauthenticated access to resources.

8.1.2.  Example: DAV:principal-match REPORT

   The the ACL method

   In the following example identifies example, user "fielding", authenticated by
   information in the members of Authorization header, grants the collection principal
   identified by the URL http://www.example.com/doc that are owned by http://www.example.com/users/esedlar (i.e., the current user. The current
   user ("gclemm") is authenticated using "esedlar") read and write privileges, grants the owner of the
   resource read-acl and write-acl privileges, and grants everyone read
   privileges.

   >> Request <<

   ACL /top/container/ HTTP/1.1
   Host: www.example.com
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx
   Authorization: Digest authentication. username="fielding",
     realm="users@example.com", nonce="...",
     uri="/top/container/", response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:acl xmlns:D="DAV:">
     <D:ace>
       <D:principal>
         <D:href>http://www.example.com/users/esedlar</D:href>
       </D:principal>
       <D:grant>
         <D:privilege><D:read/></D:privilege>
         <D:privilege><D:write/></D:privilege>
       </D:grant>
     </D:ace>



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     <D:ace>
       <D:principal>
         <D:property><D:owner/></D:property>
       </D:principal>
       <D:grant>
         <D:privilege><D:read-acl/></D:privilege>
         <D:privilege><D:write-acl/></D:privilege>
       </D:grant>
     </D:ace>
     <D:ace>
       <D:principal><D:all/></D:principal>
       <D:grant>
         <D:privilege><D:read/></D:privilege>
       </D:grant>
     </D:ace>
   </D:acl>

   >> Response <<

   HTTP/1.1 200 OK

8.1.3.  Example: ACL method failure due to protected ACE conflict

   In the following request, user "fielding", authenticated by
   information in the Authorization header, attempts to deny the
   principal identified by the URL http://www.example.com/users/esedlar
   (i.e., the user "esedlar") write privileges.  Prior to the request,
   the DAV:acl property on the resource contained a protected ACE (see
   Section 5.5.3) granting DAV:owner the DAV:read and DAV:write
   privileges.  The principal identified by URL http://www.example.com/
   users/esedlar is the owner of the resource.  The ACL method
   invocation fails because the submitted ACE conflicts with the
   protected ACE, thus violating the semantics of ACE protection.

   >> Request <<

   REPORT /doc/

   ACL /top/container/ HTTP/1.1
   Host: www.example.com
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx
   Authorization: Digest username="gclemm", username="fielding",
     realm="users@example.com", nonce="...",
     uri="/papers/",
     uri="/top/container/", response="...", opaque="..."
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx
   Depth: 0

   <?xml version="1.0" encoding="utf-8" ?>
   <D:principal-match
   <D:acl xmlns:D="DAV:">
     <D:principal-property>
       <D:owner/>
     </D:principal-property>
   </D:principal-match>
     <D:ace>
       <D:principal>



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         <D:href>http://www.example.com/users/esedlar</D:href>
       </D:principal>
       <D:deny>
         <D:privilege><D:write/></D:privilege>
       </D:deny>
     </D:ace>
   </D:acl>

   >> Response <<

   HTTP/1.1 207 Multi-Status 403 Forbidden
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx xxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus
   <D:error xmlns:D="DAV:">
     <D:response>
       <D:href>http://www.example.com/doc/foo.html</D:href>
       <D:status>HTTP/1.1 200 OK</D:status>
     </D:response>
     <D:response>
       <D:href>http://www.example.com/doc/img/bar.gif</D:href>
       <D:status>HTTP/1.1 200 OK</D:status>
     </D:response>
   </D:multistatus>


9.4 DAV:principal-property-search REPORT

   The DAV:principal-property-search REPORT performs a search for all
   principals whose properties contain character data that matches
     <D:no-protected-ace-conflict/>
   </D:error>

8.1.4.  Example: ACL method failure due to an inherited ACE conflict

   In the
   search criteria specified following request, user "ejw", authenticated by information in
   the request. One expected use of this
   report is Authorization header, tries to discover change the URL of a principal associated with a given
   person or group by searching for them by name. access control list on
   the resource http://www.example.com/top/index.html.  This is done resource
   has two inherited ACEs.

   Inherited ACE #1 grants the principal identified by
   searching over DAV:displayname, which is defined on all principals.

   The actual search method (exact matching vs. substring matching vs,
   prefix-matching, case-sensitivity) deliberately URL http://
   www.example.com/users/ejw (i.e., the user "ejw") http://
   www.example.com/privs/write-all and DAV:read-acl privileges.  On this
   server, http://www.example.com/privs/write-all is left to an aggregate
   privilege containing DAV:write, and DAV:write-acl.

   Inherited ACE #2 grants principal DAV:all the server



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   implementation DAV:read privilege.

   The request attempts to allow implementation on a wide set of possible user
   management systems. In cases where a (non-inherited) ACE, denying the implementation of
   DAV:principal-property-search is not constrained
   principal identified by the semantics of
   an underlying URL http://www.example.com/users/ejw
   (i.e., the user management repository, preferred default semantics
   are caseless substring matches.

   For implementation efficiency, servers do not typically support
   searching on all properties. A search requesting properties that are
   not searchable for a particular principal will not match "ejw") DAV:write permission.  This conflicts with
   inherited ACE #1.  Note that
   principal.

   Support for the DAV:principal-property-search decision to report an inherited ACE
   conflict is REQUIRED.

      Implementation Note: The value of a WebDAV property is a sequence
      of well-formed XML, and hence can include any character in specific to this server implementation.  Another server
   implementation could have allowed the
      Unicode/ISO-10646 standard, that is, most known characters in
      human languages. Due new ACE to be set, and then
   used normal ACE evaluation rules to determine whether the idiosyncrasies of case mapping across
      human languages, implementation of case-insensitive matching is
      non-trivial. Implementors of servers that do perform substring
      matching are strongly encouraged new ACE has
   any impact on the privileges available to a principal.









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   >> Request <<

   ACL /top/index.html HTTP/1.1
   Host: www.example.com
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx
   Authorization: Digest username="ejw",
     realm="users@example.com", nonce="...",
     uri="/top/index.html", response="...", opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:acl xmlns:D="DAV:" xmlns:F="http://www.example.com/privs/">
     <D:ace>
       <D:principal>
          <D:href>http://www.example.com/users/ejw</D:href>
       </D:principal>
       <D:grant><D:write/></D:grant>
     </D:ace>
   </D:acl>

   >> Response <<

   HTTP/1.1 403 Forbidden
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:error xmlns:D="DAV:">
     <D:no-inherited-ace-conflict/>
   </D:error>

8.1.5.  Example: ACL method failure due to consult "The Unicode Standard"
      [UNICODE4], especially Section 5.18, Subsection "Caseless
      Matching", for guidance when implementing their case-insensitive
      matching algorithms.

      Implementation Note: Some implementations of this protocol will
      use an LDAP repository for storage of principal metadata. The
      schema describing each attribute (akin attempt to set grant and
        deny in a WebDAV property) single ACE

   In this example, user "ygoland", authenticated by information in an
      LDAP repository specifies whether it supports case-sensitive or
      caseless searching. One of the benefits of leaving the search
      method
   Authorization header, tries to change the discretion of the server implementation is the
      default LDAP attribute search behavior can be used when
      implementing access control list on the DAV:principal-property-search report.

   Marshalling:
   resource http://www.example.com/diamond/engagement-ring.gif.  The ACL
   request body MUST be a DAV:principal-property-search XML
      element containing includes a search specification single, syntactically and an optional list of
      properties. For every principal that matches the search
      specification, the response will contain the value of semantically incorrect
   ACE, which attempts to grant the
      requested properties on that principal.

      <!ELEMENT principal-property-search
       ((property-search+), prop?, apply-to-principal-collection-set?) >

      By default, group identified by the report searches all members (at any depth) of URL http://
   www.example.com/users/friends DAV:read privilege and deny the
      collection
   principal identified by URL http://www.example.com/users/ygoland-so
   (i.e., the Request-URI.  If
      DAV:apply-to-principal-collection-set user "ygoland-so") DAV:read privilege.  However, it is specified
   illegal to have multiple principal elements, as well as both a grant
   and deny element in the same ACE, so the request fails due to poor
   syntax.






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   >> Request <<

   ACL /diamond/engagement-ring.gif HTTP/1.1
   Host: www.example.com
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxxx
   Authorization: Digest username="ygoland",
     realm="users@example.com", nonce="...",
     uri="/diamond/engagement-ring.gif", response="...",
     opaque="..."

   <?xml version="1.0" encoding="utf-8" ?>
   <D:acl xmlns:D="DAV:">
     <D:ace>
       <D:principal>
         <D:href>http://www.example.com/users/friends</D:href>
       </D:principal>
       <D:grant><D:read/></D:grant>
       <D:principal>
         <D:href>http://www.example.com/users/ygoland-so</D:href>
       </D:principal>
       <D:deny><D:read/></D:deny>
     </D:ace>
   </D:acl>

   >> Response <<

   HTTP/1.1 400 Bad Request
   Content-Length: 0

   Note that if the request
      body, had been divided into two ACEs, one to
   grant, and one to deny, the request is applied instead to each collection identified



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9.  Access Control Protocol        December 2003


      by the DAV:prinicipal-collection-set property of the resource
      identified by the Request-URI. Reports

9.1.  REPORT Method

   The DAV:property-search element contains REPORT method (defined in Section 3.6 of [RFC3253]) provides an
   extensible mechanism for obtaining information about a prop element
      enumerating resource.
   Unlike the properties to be searched and a match element,
      containing PROPFIND method, which returns the search string.

      <!ELEMENT property-search (prop, match) >
      prop: see RFC 2518, Section 12.11

      <!ELEMENT match #PCDATA >

      Multiple property-search elements value of one or multiple elements within a
      DAV:prop element will be interpreted with a logical AND.

      This report is only defined when more
   named properties, the Depth header has value "0";
      other values result REPORT method can involve more complex
   processing.  REPORT is valuable in a 400 (Bad Request) error response. Note
      that [RFC3253], Section 3.6, states that if cases where the Depth header is
      not present, it defaults server has access
   to a value all of "0".

      The response body for a successful the information needed to perform the complex request MUST be (such
   as a
      DAV:multistatus XML element. In the case query), and where there are no
      response elements, it would require multiple requests for the returned multistatus XML element is empty.

      multistatus: see
   client to retrieve the information needed to perform the same
   request.




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RFC 2518, Section 12.9

      The response body for a successful DAV:principal-property-search
      REPORT request 3744             WebDAV Access Control Protocol             May 2004


   A server that supports the WebDAV Access Control Protocol MUST contain  a DAV:response element for each
      principal whose property values satisfy
   support the search specification
      given DAV:expand-property report (defined in DAV:principal-property-search. Section 3.8 of
   [RFC3253]).

9.2.  DAV:acl-principal-prop-set Report

   The response body DAV:acl-principal-prop-set report returns, for an unsuccessful
      DAV:principal-property-search REPORT request MUST contain, after all principals in
   the XML element indicating DAV:acl property (of the failed precondition Request-URI) that are identified by
   http(s) URLs or
      postcondition, by a DAV:prop element containing DAV:property principal, the property that
      caused value of the pre/postcondition to fail.

      If DAV:prop is
   properties specified in the REPORT request body, body.  In the properties
      specified in case where a
   principal URL appears multiple times, the DAV:prop element DAV:acl-principal-prop-set
   report MUST be reported in return the
      DAV:response elements.

   Preconditions:

      None

   Postconditions:

      (DAV:number-of-matches-within-limits): The number properties for that principal only once.
   Support for this report is REQUIRED.

   One expected use of matching



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      principals must fall within server-specific, predefined limits.
      For example, this condition might be triggered if a search
      specification would cause report is to retrieve the return human readable
   name (found in the DAV:displayname property) of each principal found
   in an extremely large number
      of responses.


9.4.1 Matching

   There are several cases to consider when matching strings. The
   easiest case ACL.  This is when useful for constructing user interfaces that show
   each ACE in a property value human readable form.

   Marshalling

      The request body MUST be a DAV:acl-principal-prop-set XML element.

      <!ELEMENT acl-principal-prop-set ANY>
      ANY value: a sequence of one or more elements, with at most one
                 DAV:prop element.
      prop: see RFC 2518, Section 12.11

      This report is "simple" and has only
   character information item content (see [REC-XML-INFOSET]). For
   example, the search string "julian" would match defined when the DAV:displayname
   property with Depth header has value "Julian Reschke". "0";
      other values result in a 400 (Bad Request) error response.  Note
      that [RFC3253], Section 3.6, states that if the on-the-wire
   marshalling Depth header is
      not present, it defaults to a value of DAV:displayname in this case is:

   <D:displayname xmlns:D="DAV:">Julian Reschke</D:displayname> "0".

      The name of the property is encoded into the response body for a successful request MUST be a
      DAV:multistatus XML element information
   item, and the character information item content of (i.e., the property is
   "Julian Reschke".

   A more complicated case occurs when properties have mixed content
   (that is, compound values consisting of multiple child element items,
   other types of information items, and character information item
   content). Consider response uses the property "aprop" in same
      format as the namespace "http://
   www.example.com/props/", marshalled as:

   <W:aprop xmlns:W="http://www.example.com/props/">
     {cdata 0}<W:elem1>{cdata 1}</W:elem1>
     <W:elem2>{cdata 2}</W:elem2>{cdata 3}
   </W:aprop>

   In this case, matching is performed on each individual contiguous
   sequence of character information items. response for PROPFIND).  In the example above, a
   search string would be compared to case where there are
      no response elements, the four following strings:

   {cdata 0}
   {cdata 1}
   {cdata 2}
   {cdata 3}

   That is, four individual matches would be performed, one each returned multistatus XML element is
      empty.

      multistatus: see RFC 2518, Section 12.9

      The response body for
   {cdata 0}, {cdata 1}, {cdata 2}, and {cdata 3}.

9.4.2 Example: a successful DAV:principal-property-search DAV:acl-principal-prop-set
      REPORT

   In this example, the client requests the request MUST contain a DAV:response element for each
      principal URLs identified by an http(s) URL listed in a DAV:principal
      XML element of all users
   whose DAV:displayname an ACE within the DAV:acl property contains of the substring "doE" and whose resource
      identified by the Request-URI.





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   "title" property in the namespace "http://BigCorp.com/ns/" (that is,
   their professional title) contains "Sales".  In addition, the client
   requests five properties to be returned with the             May 2004


   Postconditions:

      (DAV:number-of-matches-within-limits): The number of matching principals:

   In the DAV: namespace: displayname

   In
      principals must fall within server-specific, predefined limits.
      For example, this condition might be triggered if a search
      specification would cause the http://www.example.com/ns/ namespace: department, phone,
   office, salary return of an extremely large number
      of responses.

9.2.1.  Example: DAV:acl-principal-prop-set Report

   Resource http://www.example.com/index.html has an ACL with three
   ACEs:

   ACE #1: All principals (DAV:all) have DAV:read and DAV:read-current-
   user-privilege-set access.

   ACE #2: The response shows that two principal resources meet the search
   specification, "John Doe" and "Zygdoebert Smith". identified by http://www.example.com/people/
   gstein (the user "gstein") is granted DAV:write,  DAV:write-acl,
   DAV:read-acl privileges.

   ACE #3: The property
   "salary" in namespace "http://www.example.com/ns/" group identified by http://www.example.com/groups/authors
   (the "authors" group) is not returned,
   since granted DAV:write and DAV:read-acl
   privileges.

   The following example shows a DAV:acl-principal-prop-set report
   requesting the principal making DAV:displayname property.  It returns the request does value of
   DAV:displayname for resources http://www.example.com/people/gstein
   and http://www.example.com/groups/authors , but not have sufficient
   access permissions to read for DAV:all,
   since this property. is not an http(s) URL.

   >> Request <<

   REPORT /users/ /index.html HTTP/1.1
   Host: www.example.com
   Content-Type: text/xml; charset=utf-8
   Content-Length: xxxx
   Depth: 0

   <?xml version="1.0" encoding="utf-8" ?>
   <D:principal-property-search xmlns:D="DAV:">
     <D:property-search>
       <D:prop>
         <D:displayname/>
       </D:prop>
       <D:match>doE</D:match>
     </D:property-search>
     <D:property-search>
       <D:prop xmlns:B="http://www.example.com/ns/">
         <B:title/>
       </D:prop>
       <D:match>Sales</D:match>
     </D:property-search>
     <D:prop xmlns:B="http://www.example.com/ns/"> charset="utf-8"
   Content-Length: xxxx
   Depth: 0

   <?xml version="1.0" encoding="utf-8" ?>
   <D:acl-principal-prop-set xmlns:D="DAV:">
     <D:prop>
       <D:displayname/>
       <B:department/>
       <B:phone/>
       <B:office/>
       <B:salary/>
     </D:prop>
   </D:principal-property-search>

   >> Response <<
   </D:acl-principal-prop-set>







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   >> Response <<

   HTTP/1.1 207 Multi-Status
   Content-Type: text/xml; charset=utf-8 charset="utf-8"
   Content-Length: xxxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:" xmlns:B="http://BigCorp.com/ns/"> xmlns:D="DAV:">
     <D:response>
       <D:href>http://www.example.com/users/jdoe</D:href>
       <D:href>http://www.example.com/people/gstein</D:href>
       <D:propstat>
         <D:prop>
           <D:displayname>John Doe</D:displayname>
           <B:department>Widget Sales</B:department>
           <B:phone>234-4567</B:phone>
           <B:office>209</B:office>
           <D:displayname>Greg Stein</D:displayname>
         </D:prop>
         <D:status>HTTP/1.1 200 OK</D:status>
       </D:propstat>
       <D:propstat>
         <D:prop>
           <B:salary/>
         </D:prop>
         <D:status>HTTP/1.1 403 Forbidden</D:status>
       </D:propstat>
     </D:response>
     <D:response>
       <D:href>http://www.example.com/users/zsmith</D:href>
       <D:href>http://www.example.com/groups/authors</D:href>
       <D:propstat>
         <D:prop>
           <D:displayname>Zygdoebert Smith</D:displayname>
           <B:department>Gadget Sales</B:department>
           <B:phone>234-7654</B:phone>
           <B:office>114</B:office>
           <D:displayname>Site authors</D:displayname>
         </D:prop>
         <D:status>HTTP/1.1 200 OK</D:status>
       </D:propstat>
       <D:propstat>
         <D:prop>
           <B:salary/>
         </D:prop>
         <D:status>HTTP/1.1 403 Forbidden</D:status>
       </D:propstat>
     </D:response>
   </D:multistatus>


9.5 DAV:principal-search-property-set

9.3.  DAV:principal-match REPORT

   The DAV:principal-search-property-set REPORT identifies those



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   properties that may be searched using the
   DAV:principal-property-search REPORT (defined in Section 9.4).

   Servers MUST support the DAV:principal-search-property-set DAV:principal-match REPORT on is used to identify all collections identified in the value of a
   DAV:principal-collection-set property.

   An access control protocol user agent could use the results members (at
   any depth) of the
   DAV:principal-search-property-set REPORT to present a query interface
   to collection identified by the user for retrieving principals.

   Support for this report is REQUIRED.

      Implementation Note: Some clients will have only limited screen
      real estate for Request-URI that are
   principals and that match the display of lists of searchable properties. current user.  In
      this case, a user might appreciate having particular, if the most frequently
      searched properties
   collection contains principals, the report can be displayed on-screen, rather than having used to
      scroll through a long list identify
   all members of searchable properties. One mechanism
      for signaling the most frequently searched properties is to return
      them towards collection that match the current user.
   Alternatively, if the collection contains resources that have a
   property that identifies a principal (e.g., DAV:owner), the start report
   can be used to identify all members of the collection whose property
   identifies a list of properties. A client can then
      preferentially display principal that matches the list current user.  For example,
   this report can return all of properties in order, increasing the likelihood resources in a collection hierarchy
   that are owned by the most frequently searched properties will
      appear on-screen, and will not require scrolling current user.  Support for their
      selection. this report is
   REQUIRED.

   Marshalling:

      The request body MUST be an empty
      DAV:principal-search-property-set a DAV:principal-match XML element.
      <!ELEMENT principal-match ((principal-property | self), prop?)>
      <!ELEMENT principal-property ANY>



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      ANY value: an element whose value identifies a property.  The
      expectation is the value of the named property typically contains
      an href element that contains the URI of a principal
      <!ELEMENT self EMPTY>
      prop: see RFC 2518, Section 12.11

      This report is only defined when the Depth header has value "0";
      other values result in a 400 (Bad Request) error response.  Note
      that [RFC3253], Section 3.6, states that if the Depth header is
      not present, it defaults to a value of "0".  The response body for
      a successful request MUST be a DAV:principal-search-property-set XML
      element, containing a DAV:principal-search-property DAV:multistatus XML element
      for each property that may be searched with element.  In
      the
      DAV:principal-property-search REPORT. A server MAY limit its case where there are no response to just a subset of elements, the searchable properties, such as
      those likely to be useful to an interactive access control client.

      <!ELEMENT principal-search-property-set
       (principal-search-property*) >

      Each DAV:principal-search-property returned
      multistatus XML element contains exactly
      one searchable property, and is empty.

      multistatus: see RFC 2518, Section 12.9

      The response body for a description successful DAV:principal-match REPORT
      request MUST contain a DAV:response element for each member of the property.




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      <!ELEMENT principal-search-property (prop, description) >

      The DAV:prop
      collection that matches the current user.  When the
      DAV:principal-property element contains one is used, a match occurs if the
      current user is matched by the principal identified by the URI
      found in the DAV:href element of the property on which identified by the
      server is able to perform a DAV:principal-property-search REPORT.

      prop: see RFC 2518, Section 12.11

      The description
      DAV:principal-property element.  When the DAV:self element is used
      in a human-readable description of what
      information this property represents. Servers MUST indicate DAV:principal-match report issued against a group, it matches
      the
      human language of group if a member identifies the description using same principal as the xml:lang attribute and
      SHOULD consider current
      user.

      If DAV:prop is specified in the HTTP Accept-Language request header when
      selecting one of multiple available languages.

      <!ELEMENT description #PCDATA >


9.5.1 Example: DAV:principal-search-property-set REPORT

   In this example, the client determines body, the set of searchable
   principal properties by requesting
      specified in the
   DAV:principal-search-property-set DAV:prop element MUST be reported in the
      DAV:response elements.

9.3.1.  Example: DAV:principal-match REPORT on

   The following example identifies the root members of the server's
   principal URL collection set,
   identified by http://www.example.com/
   users/. the URL http://www.example.com/doc that are owned by
   the current user.  The current user ("gclemm") is authenticated using
   Digest authentication.

   >> Request <<

   REPORT /users/ /doc/ HTTP/1.1
   Host: www.example.com
   Authorization: Digest username="gclemm",
     realm="users@example.com", nonce="...",
     uri="/papers/", response="...", opaque="..."
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx
   Accept-Language: en, de
   Authorization: BASIC d2FubmFtYWs6cGFzc3dvcmQ= xxxx
   Depth: 0

   <?xml version="1.0" encoding="utf-8" ?>
   <D:principal-search-property-set xmlns:D="DAV:"/>



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   <?xml version="1.0" encoding="utf-8" ?>
   <D:principal-match xmlns:D="DAV:">
     <D:principal-property>
       <D:owner/>
     </D:principal-property>
   </D:principal-match>

   >> Response <<

   HTTP/1.1 200 OK 207 Multi-Status
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx xxxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:principal-search-property-set
   <D:multistatus xmlns:D="DAV:">
     <D:principal-search-property>
       <D:prop>
         <D:displayname/>
       </D:prop>
       <D:description xml:lang="en">Full name</D:description>
     </D:principal-search-property>
     <D:principal-search-property>
       <D:prop xmlns:B="http://BigCorp.com/ns/">
         <B:title/>
       </D:prop>
       <D:description xml:lang="en">Job title</D:description>
     </D:principal-search-property>
   </D:principal-search-property-set>


10. XML Processing

   Implementations of this specification MUST support
     <D:response>
       <D:href>http://www.example.com/doc/foo.html</D:href>
       <D:status>HTTP/1.1 200 OK</D:status>
     </D:response>
     <D:response>
       <D:href>http://www.example.com/doc/img/bar.gif</D:href>
       <D:status>HTTP/1.1 200 OK</D:status>
     </D:response>
   </D:multistatus>

9.4.  DAV:principal-property-search REPORT

   The DAV:principal-property-search REPORT performs a search for all
   principals whose properties contain character data that matches the XML element
   ignore rule, as
   search criteria specified in Section 23.3.2 of [RFC2518], and the XML
   Namespace recommendation [REC-XML-NAMES].

   Note that request.  One expected use of the DAV namespace is reserved for XML elements and
   property names defined in a standards-track or Experimental IETF RFC.

11. Internationalization Considerations

   In this specification, the only human-readable content can be found
   in the description XML element, found within
   report is to discover the
   DAV:supported-privilege-set property.  This element contains a
   human-readable description URL of the capabilities controlled by a
   privilege.  As principal associated with a result, the description element must be capable of
   representing descriptions in multiple character sets.  Since the
   description element given
   person or group by searching for them by name.  This is found within a WebDAV property, it done by
   searching over DAV:displayname, which is
   represented defined on the wire as XML [REC-XML], and hence can leverage
   XML's language tagging and character set encoding capabilities.
   Specifically, XML processors at minimum must be able all principals.

   The actual search method (exact matching vs. substring matching vs,
   prefix-matching, case-sensitivity) deliberately is left to read XML
   elements encoded using the UTF-8 [RFC3629] encoding server
   implementation to allow implementation on a wide set of possible user
   management systems.  In cases where the ISO 10646
   multilingual plane. XML examples in this specification demonstrate
   use implementation of
   DAV:principal-property-search is not constrained by the charset parameter semantics of
   an underlying user management repository, preferred default semantics
   are caseless substring matches.

   For implementation efficiency, servers do not typically support
   searching on all properties.  A search requesting properties that are
   not searchable for a particular principal will not match that
   principal.

   Support for the Content-Type header, as defined
   in [RFC3023], as well as the XML "encoding" attribute, which together DAV:principal-property-search report is REQUIRED.



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   provide charset identification information for MIME             May 2004


      Implementation Note: The value of a WebDAV property is a sequence
      of well-formed XML, and XML
   processors. Futhermore, this specification requires server
   implementations hence can include any character in the
      Unicode/ISO-10646 standard, that is, most known characters in
      human languages.  Due to tag description fields with the xml:lang attribute
   (see Section 2.12 idiosyncrasies of [REC-XML]), which specifies the case mapping across
      human language
   of the description. Additionally, server implementations should take
   into account the value languages, implementation of the Accept-Language HTTP header to
   determine which description string to return.

   For XML elements other than the description element, it case-insensitive matching is expected
      non-trivial.  Implementors of servers that implementations will treat the property names, privilege names,
   and values as tokens, and convert these tokens into human-readable
   text in the user's language and character set when displayed do perform substring
      matching are strongly encouraged to a
   person.  Only a generic WebDAV property display utility would display
   these values in consult "The Unicode Standard"
      [UNICODE4], especially Section 5.18, Subsection "Caseless
      Matching", for guidance when implementing their raw form to a human user.

   For error reporting, we follow the convention case-insensitive
      matching algorithms.

      Implementation Note: Some implementations of HTTP/1.1 status
   codes, including with this protocol will
      use an LDAP repository for storage of principal metadata.  The
      schema describing each status code attribute (akin to a short, English description WebDAV property) in an
      LDAP repository specifies whether it supports case-sensitive or
      caseless searching.  One of the code (e.g., 200 (OK)).  While benefits of leaving the possibility exists that a
   poorly crafted user agent would display this message search
      method to the discretion of the server implementation is the
      default LDAP attribute search behavior can be used when
      implementing the DAV:principal-property-search report.

   Marshalling:

      The request body MUST be a user,
   internationalized applications will ignore this message, DAV:principal-property-search XML
      element containing a search specification and display an appropriate message in optional list of
      properties.  For every principal that matches the user's language and character set.

   Further internationalization considerations for this protocol are
   described in search
      specification, the WebDAV Distributed Authoring protocol specification
   [RFC2518].

12. Security Considerations

   Applications and users response will contain the value of this access control protocol should be
   aware the
      requested properties on that principal.

      <!ELEMENT principal-property-search
       ((property-search+), prop?, apply-to-principal-collection-set?) >

      By default, the report searches all members (at any depth) of several security considerations, detailed below. In addition
   to the discussion in this document,
      collection identified by the security considerations
   detailed Request-URI.  If DAV:apply-to-
      principal-collection-set is specified in the HTTP/1.1 specification [RFC2616], request body, the WebDAV
   Distributed Authoring
      request is applied instead to each collection identified by the
      DAV:principal-collection-set property of the resource identified
      by the Request-URI.

      The DAV:property-search element contains a prop element
      enumerating the properties to be searched and a match element,
      containing the search string.

      <!ELEMENT property-search (prop, match) >
      prop: see RFC 2518, Section 12.11

      <!ELEMENT match #PCDATA >





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      Multiple property-search elements or multiple elements within a
      DAV:prop element will be considered in interpreted with a
   security analysis of this protocol.

12.1 Increased Risk of Compromised Users

   In logical AND.

      This report is only defined when the absence of Depth header has value "0";
      other values result in a mechanism for remotely manipulating access
   control lists, 400 (Bad Request) error response.  Note
      that [RFC3253], Section 3.6, states that if the Depth header is
      not present, it defaults to a single user's authentication credentials are
   compromised, only those resources value of "0".

      The response body for which the user has access
   permission can a successful request MUST be read, modified, moved, or deleted. With the
   introduction of this access control protocol, if a single compromised
   user has
      DAV:multistatus XML element.  In the ability to change ACLs case where there are no
      response elements, the returned multistatus XML element is empty.

      multistatus: see RFC 2518, Section 12.9

      The response body for a broad range of other users
   (e.g., successful DAV:principal-property-search
      REPORT request MUST contain  a super-user), DAV:response element for each
      principal whose property values satisfy the search specification
      given in DAV:principal-property-search.

      If DAV:prop is specified in the request body, the properties
      specified in the DAV:prop element MUST be reported in the
      DAV:response elements.

   Preconditions:

      None

   Postconditions:

      (DAV:number-of-matches-within-limits): The number of resources that could matching
      principals must fall within server-specific, predefined limits.
      For example, this condition might be altered
   by triggered if a single compromised user increases. This risk can be mitigated by
   limiting search
      specification would cause the return of an extremely large number
      of people who have write-acl privileges across responses.

9.4.1.  Matching

   There are several cases to consider when matching strings.  The
   easiest case is when a
   broad range property value is "simple" and has only
   character information item content (see [REC-XML-INFOSET]).  For
   example, the search string "julian" would match the DAV:displayname
   property with value "Julian Reschke".  Note that the on-the-wire
   marshaling of resources. DAV:displayname in this case is:

   <D:displayname xmlns:D="DAV:">Julian Reschke</D:displayname>






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12.2 Risks of the DAV:read-acl and DAV:current-user-privilege-set
     Privileges             May 2004


   The ability to read the access privileges (stored in the DAV:acl
   property), or the privileges permitted the currently authenticated
   user (stored in the DAV:current-user-privilege-set property) on a
   resource may seem innocuous, since reading an ACL cannot possibly
   affect the resource's state. However, if all resources have
   world-readable ACLs, it is possible to perform an exhaustive search
   for those resources that have inadvertently left themselves in a
   vulnerable state, such as being world-writeable. In particular, name of the property retrieval method PROPFIND, executed with Depth infinity on
   an entire hierarchy, is a very efficient way to retrieve encoded into the DAV:acl
   or DAV:current-user-privilege-set properties. Once found, this
   vulnerability can be exploited by a denial XML element information
   item, and the character information item content of service attack in which the open resource property is repeatedly overwritten. Alternately, writeable
   resources can be modified in undesirable ways.

   To reduce this risk, read-acl privileges should not be granted to
   unauthenticated principals, and restrictions on read-acl
   "Julian Reschke".

   A more complicated case occurs when properties have mixed content
   (that is, compound values consisting of multiple child element items,
   other types of information items, and
   read-current-user-privilege-set privileges for authenticated
   principals should be carefully analyzed when deploying this protocol.
   Access to character information item
   content).  Consider the current-user-privilege-set property will involve a
   tradeoff of usability versus security. When "aprop" in the
   current-user-privilege-set is visible, user interfaces are expected
   to provide enhanced information concerning permitted and restricted
   operations, yet namespace "http://
   www.example.com/props/", marshaled as:

   <W:aprop xmlns:W="http://www.example.com/props/">
     {cdata 0}<W:elem1>{cdata 1}</W:elem1>
     <W:elem2>{cdata 2}</W:elem2>{cdata 3}
   </W:aprop>

   In this case, matching is performed on each individual contiguous
   sequence of character information may also indicate items.  In the example above, a vulnerability
   that could
   search string would be exploited. Deployment of this protocol will need compared to
   evaluate this tradeoff in light of the requirements of the deployment
   environment.

12.3 No Foreknowledge of Initial ACL four following strings:

   {cdata 0}
   {cdata 1}
   {cdata 2}
   {cdata 3}

   That is, four individual matches would be performed, one each for
   {cdata 0}, {cdata 1}, {cdata 2}, and {cdata 3}.

9.4.2.  Example: successful DAV:principal-property-search REPORT

   In an effort to reduce protocol complexity, this protocol
   specification intentionally does not address example, the issue client requests the principal URLs of how to
   manage or discover all users
   whose DAV:displayname property contains the initial ACL that is placed upon a resource
   when it is created. The only way to discover substring "doE" and whose
   "title" property in the initial ACL is namespace "http://BigCorp.com/ns/" (that is,
   their professional title) contains "Sales".  In addition, the client
   requests five properties to
   create a new resource, then retrieve be returned with the value of matching principals:

   In the DAV:acl
   property. This assumes DAV: namespace: displayname

   In the http://www.example.com/ns/ namespace: department, phone,
   office, salary












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   The response shows that two principal creating the resource also has
   been granted resources meet the DAV:read-acl privilege.

   As a result, it search
   specification, "John Doe" and "Zygdoebert Smith".  The property
   "salary" in namespace "http://www.example.com/ns/" is possible that a not returned,
   since the principal could create a resource,
   and then discover that its ACL grants privileges that are
   undesirable. Furthermore, making the request does not have sufficient
   access permissions to read this protocol makes it possible (though
   unlikely) property.

   >> Request <<

   REPORT /users/ HTTP/1.1
   Host: www.example.com
   Content-Type: text/xml; charset=utf-8
   Content-Length: xxxx
   Depth: 0

   <?xml version="1.0" encoding="utf-8" ?>
   <D:principal-property-search xmlns:D="DAV:">
     <D:property-search>
       <D:prop>
         <D:displayname/>
       </D:prop>
       <D:match>doE</D:match>
     </D:property-search>
     <D:property-search>
       <D:prop xmlns:B="http://www.example.com/ns/">
         <B:title/>
       </D:prop>
       <D:match>Sales</D:match>
     </D:property-search>
     <D:prop xmlns:B="http://www.example.com/ns/">
       <D:displayname/>
       <B:department/>
       <B:phone/>
       <B:office/>
       <B:salary/>
     </D:prop>
   </D:principal-property-search>

   >> Response <<

   HTTP/1.1 207 Multi-Status
   Content-Type: text/xml; charset=utf-8
   Content-Length: xxxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:multistatus xmlns:D="DAV:" xmlns:B="http://BigCorp.com/ns/">
     <D:response>
       <D:href>http://www.example.com/users/jdoe</D:href>
       <D:propstat>



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         <D:prop>
           <D:displayname>John Doe</D:displayname>
           <B:department>Widget Sales</B:department>
           <B:phone>234-4567</B:phone>
           <B:office>209</B:office>
         </D:prop>
         <D:status>HTTP/1.1 200 OK</D:status>
       </D:propstat>
       <D:propstat>
         <D:prop>
           <B:salary/>
         </D:prop>
         <D:status>HTTP/1.1 403 Forbidden</D:status>
       </D:propstat>
     </D:response>
     <D:response>
       <D:href>http://www.example.com/users/zsmith</D:href>
       <D:propstat>
         <D:prop>
           <D:displayname>Zygdoebert Smith</D:displayname>
           <B:department>Gadget Sales</B:department>
           <B:phone>234-7654</B:phone>
           <B:office>114</B:office>
         </D:prop>
         <D:status>HTTP/1.1 200 OK</D:status>
       </D:propstat>
       <D:propstat>
         <D:prop>
           <B:salary/>
         </D:prop>
         <D:status>HTTP/1.1 403 Forbidden</D:status>
       </D:propstat>
     </D:response>
   </D:multistatus>

9.5.  DAV:principal-search-property-set REPORT

   The DAV:principal-search-property-set REPORT identifies those
   properties that the creating principal could may be unable to modify searched using the
   ACL, or even delete DAV:principal-property-
   search REPORT (defined in Section 9.4).

   Servers MUST support the resource. Even when DAV:principal-search-property-set REPORT on
   all collections identified in the ACL can be modified,
   there will be value of a short period DAV:principal-
   collection-set property.

   An access control protocol user agent could use the results of time when the resource exists with
   DAV:principal-search-property-set REPORT to present a query interface
   to the initial ACL before its new ACL can be set. user for retrieving principals.



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   Several factors mitigate             May 2004


   Support for this risk. Human principals are often aware
   of report is REQUIRED.

      Implementation Note: Some clients will have only limited screen
      real estate for the default access permissions in their editing environments and
   take display of lists of searchable properties.  In
      this into account when writing information. Furthermore, default
   privilege policies are usually very conservative, limiting the
   privileges granted by case, a user might appreciate having the initial ACL.

13. Authentication

   Authentication mechanisms defined most frequently
      searched properties be displayed on-screen, rather than having to
      scroll through a long list of searchable properties.  One
      mechanism for use with HTTP and WebDAV also
   apply signaling the most frequently searched properties is
      to this WebDAV Access Control Protocol, in particular return them towards the Basic
   and Digest authentication mechanisms defined in [RFC2617].
   Implementation start of a list of properties.  A
      client can then preferentially display the list of properties in
      order, increasing the ACL spec requires likelihood that Basic authentication, if
   used, MUST only be supported over secure transport such as TLS.

14. IANA Considerations

   This document uses the namespace defined by [RFC2518] most frequently searched
      properties will appear on-screen, and will not require scrolling
      for their selection.

   Marshalling:

      The request body MUST be an empty DAV:principal-search-property-
      set XML
   elements. That is, this specification uses the "DAV:" URI namespace,
   previously registered in element.

      This report is only defined when the URI schemes registry. All Depth header has value "0";
      other IANA
   considerations mentioned values result in [RFC2518] are also applicable to this
   specification.

15. Acknowledgements

   This protocol is a 400 (Bad Request) error response.  Note
      that [RFC3253], Section 3.6, states that if the collaborative product Depth header is
      not present, it defaults to a value of the WebDAV ACL design
   team: Bernard Chester, Geoff Clemm, Anne Hopkins, Barry Lind, Sean
   Lyndersay, Eric Sedlar, Greg Stein, and Jim Whitehead. "0".

      The authors
   are grateful for the detailed review and comments provided by Jim
   Amsden, Dylan Barrell, Gino Basso, Murthy Chintalapati, Lisa
   Dusseault, Stefan Eissing, Tim Ellison, Yaron Goland, Dennis
   Hamilton, Laurie Harper, Eckehard Hermann, Ron Jacobs, Chris Knight,
   Remy Maucherat, Larry Masinter, Joe Orton, Peter Raymond, Julian
   Reschke, and Keith Wannamaker. We thank Keith Wannamaker response body MUST be  a DAV:principal-search-property-set XML
      element, containing a DAV:principal-search-property XML element
      for each property that may be searched with the
   initial text DAV:principal-
      property-search REPORT.  A server MAY limit its response to just a
      subset of the principal property search sections. Prior work on
   WebDAV searchable properties, such as those likely to be
      useful to an interactive access control protocols has been performed by Yaron Goland,
   Paul Leach, Lisa Dusseault, Howard Palmer, client.

      <!ELEMENT principal-search-property-set
       (principal-search-property*) >

      Each DAV:principal-search-property XML element contains exactly
      one searchable property, and Jon Radoff. We would
   like to acknowledge the foundation laid for us by the authors a description of the
   DeltaV, WebDAV and HTTP protocols upon which this protocol is
   layered, and the invaluable feedback from property.

      <!ELEMENT principal-search-property (prop, description) >

      The DAV:prop element contains one principal property on which the WebDAV working group.

Normative References

   [REC-XML]  Bray, T., Paoli, J., Sperberg-McQueen, C. and E. Maler,
              "Extensible Markup Language (XML) 1.0 (2nd ed)", W3C REC
              REC-xml-20001006, October 2000, <http://www.w3.org/TR/
              2000/REC-xml-20001006>.

   [REC-XML-INFOSET]
      server is able to perform a DAV:principal-property-search REPORT.

      prop: see RFC 2518, Section 12.11








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              Cowan, J. and R. Tobin, "XML Information Set", W3C REC
              REC-xml-infoset-20011024, October 2001, <http://
              www.w3.org/TR/2001/REC-xml-infoset-20011024>.

   [REC-XML-NAMES]
              Bray, T., Hollander, D. and A. Layman, "Namespaces in
              XML", W3C REC REC-xml-names-19990114, January 1999,
              <http://www.w3.org/TR/1999/REC-xml-names-19990114>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2518]  Goland, Y., Whitehead, E., Faizi, A., Carter, S. and D.
              Jensen, "HTTP Extensions for Distributed Authoring --
              WEBDAV", RFC 2518, February 1999.

   [RFC2616]  Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
              Masinter, L., Leach, P.             May 2004


      The description element is a human-readable description of what
      information this property represents.  Servers MUST indicate the
      human language of the description using the xml:lang attribute and T. Berners-Lee, "Hypertext
              Transfer Protocol -- HTTP/1.1",
      SHOULD consider the HTTP Accept-Language request header when
      selecting one of multiple available languages.

      <!ELEMENT description #PCDATA >

9.5.1.  Example: DAV:principal-search-property-set REPORT

   In this example, the client determines the set of searchable
   principal properties by requesting the DAV:principal-search-
   property-set REPORT on the root of the server's principal URL
   collection set, identified by http://www.example.com/users/.

   >> Request <<

   REPORT /users/ HTTP/1.1
   Host: www.example.com
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx
   Accept-Language: en, de
   Authorization: BASIC d2FubmFtYWs6cGFzc3dvcmQ=
   Depth: 0

   <?xml version="1.0" encoding="utf-8" ?>
   <D:principal-search-property-set xmlns:D="DAV:"/>

   >> Response <<

   HTTP/1.1 200 OK
   Content-Type: text/xml; charset="utf-8"
   Content-Length: xxx

   <?xml version="1.0" encoding="utf-8" ?>
   <D:principal-search-property-set xmlns:D="DAV:">
     <D:principal-search-property>
       <D:prop>
         <D:displayname/>
       </D:prop>
       <D:description xml:lang="en">Full name</D:description>
     </D:principal-search-property>
     <D:principal-search-property>
       <D:prop xmlns:B="http://BigCorp.com/ns/">
         <B:title/>






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RFC 2616, June 1999.

   [RFC2617]  Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S.,
              Leach, P., Luotonen, A. 3744             WebDAV Access Control Protocol             May 2004


       </D:prop>
       <D:description xml:lang="en">Job title</D:description>
     </D:principal-search-property>
   </D:principal-search-property-set>

10.  XML Processing

   Implementations of this specification MUST support the XML element
   ignore rule, as specified in Section 23.3.2 of [RFC2518], and L. Stewart, "HTTP
              Authentication: Basic the XML
   Namespace recommendation [REC-XML-NAMES].

   Note that use of the DAV namespace is reserved for XML elements and Digest Access Authentication",
              RFC 2617, June 1999.

   [RFC3023]  Makoto, M., St.Laurent, S.
   property names defined in a standards-track or Experimental IETF RFC.

11.  Internationalization Considerations

   In this specification, the only human-readable content can be found
   in the description XML element, found within the DAV:supported-
   privilege-set property.  This element contains a human-readable
   description of the capabilities controlled by a privilege.  As a
   result, the description element must be capable of representing
   descriptions in multiple character sets.  Since the description
   element is found within a WebDAV property, it is represented on the
   wire as XML [REC-XML], and D. Kohn, "XML Media Types",
              RFC 3023, January 2001.

   [RFC3253]  Clemm, G., Amsden, J., Ellison, T., Kaler, C. hence can leverage XML's language tagging
   and J.
              Whitehead, "Versioning Extensions character set encoding capabilities.  Specifically, XML
   processors at minimum must be able to WebDAV", RFC 3253,
              March 2002.

   [RFC3530]  Shepler, S., Ed., Callaghan, B., Robinson, D., Thurlow,
              R., Beame, C., Eisler, M. and D. Noveck, "Network File
              System (NFS) version 4 Protocol", RFC 3530, April 2003. read XML elements encoded using
   the UTF-8 [RFC3629]  Yergeau, F., "UTF-8, a transformation format encoding of the ISO
              10646", RFC 3629, STD 63, November 2003.

Informative References

   [RFC2026]  Bradner, S., "The Internet Standards Process -- Revision
              3", BCP 9, RFC 2026, October 1996.

   [RFC2251]  Wahl, M., Howes, T. 10646 multilingual plane.
   XML examples in this specification demonstrate use of the charset
   parameter of the Content-Type header, as defined in [RFC3023], as
   well as the XML "encoding" attribute, which together provide charset
   identification information for MIME and S. Kille, "Lightweight Directory
              Access Protocol (v3)", RFC 2251, December 1997.

   [RFC2255]  Howes, T. XML processors.  Furthermore,
   this specification requires server implementations to tag description
   fields with the xml:lang attribute (see Section 2.12 of [REC-XML]),
   which specifies the human language of the description.  Additionally,
   server implementations should take into account the value of the
   Accept-Language HTTP header to determine which description string to
   return.

   For XML elements other than the description element, it is expected
   that implementations will treat the property names, privilege names,
   and M. Smith, "The LDAP URL Format", RFC 2255,



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   text in the user's language and character set when displayed to a
   person.  Only a generic WebDAV Access Control Protocol        December 2003


              December 1997.

   [UNICODE4]
              The Unicode Consortium, "The Unicode Standard - Version
              4.0", Addison-Wesley , August 2003, <http://
              www.unicode.org/versions/Unicode4.0.0/>.

              ISBN 0321185781 [4].

URIs

   [1]  <mailto:acl@webdav.org>

   [2]  <http://www.example.com/acl/>

   [3]  <http://www.ics.uci.edu/pub/ietf/webdav/>

   [4]  <urn:isbn:0321185781>


Authors' Addresses

   G. Clemm
   IBM
   20 Maguire Road
   Lexington, MA  02421

   EMail: geoffrey.clemm@us.ibm.com


   Julian F. Reschke
   greenbytes GmbH
   Salzmannstrasse 152
   Muenster, NW  48159
   Germany

   EMail: julian.reschke@greenbytes.de


   E. Sedlar
   Oracle Corporation
   500 Oracle Parkway
   Redwood Shores, CA  94065

   EMail: eric.sedlar@oracle.com property display utility would display
   these values in their raw form to a human user.

   For error reporting, we follow the convention of HTTP/1.1 status
   codes, including with each status code a short, English description
   of the code (e.g., 200 (OK)).  While the possibility exists that a



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   J. Whitehead
   U.C. Santa Cruz, Dept.             May 2004


   poorly crafted user agent would display this message to a user,
   internationalized applications will ignore this message, and display
   an appropriate message in the user's language and character set.

   Further internationalization considerations for this protocol are
   described in the WebDAV Distributed Authoring protocol specification
   [RFC2518].

12.  Security Considerations

   Applications and users of Computer Science
   1156 High Street
   Santa Cruz, CA  95064

   EMail: ejw@cse.ucsc.edu

Appendix A. this access control protocol should be
   aware of several security considerations, detailed below.  In
   addition to the discussion in this document, the security
   considerations detailed in the HTTP/1.1 specification [RFC2616], the
   WebDAV Distributed Authoring Protocol specification [RFC2518], and
   the XML Document Type Definition Addendum

   All XML elements defined Media Types specification [RFC3023] should be considered in a
   security analysis of this Document Type Definition (DTD)
   belong protocol.

12.1.  Increased Risk of Compromised Users

   In the absence of a mechanism for remotely manipulating access
   control lists, if a single user's authentication credentials are
   compromised, only those resources for which the user has access
   permission can be read, modified, moved, or deleted.  With the
   introduction of this access control protocol, if a single compromised
   user has the ability to change ACLs for a broad range of other users
   (e.g., a super-user), the DAV namespace. number of resources that could be altered
   by a single compromised user increases.  This DTD should risk can be viewed mitigated
   by limiting the number of people who have write-acl privileges across
   a broad range of resources.

12.2.  Risks of the DAV:read-acl and DAV:current-user-privilege-set
       Privileges

   The ability to read the access privileges (stored in the DAV:acl
   property), or the privileges permitted the currently authenticated
   user (stored in the DAV:current-user-privilege-set property) on a
   resource may seem innocuous, since reading an ACL cannot possibly
   affect the resource's state.  However, if all resources have world-
   readable ACLs, it is possible to perform an exhaustive search for
   those resources that have inadvertently left themselves in a
   vulnerable state, such as being world-writable.  In particular, the
   property retrieval method PROPFIND, executed with Depth infinity on
   an addendum entire hierarchy, is a very efficient way to retrieve the DTD provided DAV:acl
   or DAV:current-user-privilege-set properties.  Once found, this
   vulnerability can be exploited by a denial of service attack in [RFC2518], section 23.1.

   <!-- Privileges -- (Section 3)>

   <!ELEMENT read EMPTY>
   <!ELEMENT write EMPTY>
   <!ELEMENT write-properties EMPTY>
   <!ELEMENT write-content EMPTY>
   <!ELEMENT unlock EMPTY>
   <!ELEMENT read-acl EMPTY>
   <!ELEMENT read-current-user-privilege-set EMPTY>
   <!ELEMENT write-acl EMPTY>
   <!ELEMENT bind EMPTY>
   <!ELEMENT unbind EMPTY>
   <!ELEMENT all EMPTY>

   <!-- Principal Properties (Section 4) -->

   <!ELEMENT principal EMPTY>

   <!ELEMENT alternate-URI-set (href*)>
   <!ELEMENT principal-URL (href)>
   <!ELEMENT group-member-set (href*)>
   <!ELEMENT group-membership (href*)>

   <!-- Access Control Properties (Section 5) -->

   <!-- DAV:owner Property (Section 5.1) -->

   <!ELEMENT owner (href?)>

   <!-- DAV:group Property (Section 5.2) -->

   <!ELEMENT group (href?)> which
   the open resource is repeatedly overwritten.  Alternately, writable
   resources can be modified in undesirable ways.



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   <!-- DAV:supported-privilege-set Property (Section 5.3) -->

   <!ELEMENT supported-privilege-set (supported-privilege*)>
   <!ELEMENT supported-privilege
    (privilege, abstract?, description, supported-privilege*)>

   <!ELEMENT privilege ANY>
   <!ELEMENT abstract EMPTY>
   <!ELEMENT description #PCDATA>

   <!-- DAV:current-user-privilege-set Property (Section 5.4) -->

   <!ELEMENT current-user-privilege-set (privilege*)>

   <!-- DAV:acl Property (Section 5.5) -->

   <!ELEMENT acl (ace)* >
   <!ELEMENT ace ((principal | invert), (grant|deny), protected?,
    inherited?)>

   <!ELEMENT principal (href)
    | all | authenticated |             May 2004


   To reduce this risk, read-acl privileges should not be granted to
   unauthenticated
    | property | self)>

   <!ELEMENT all EMPTY>
   <!ELEMENT principals, and restrictions on read-acl and read-
   current-user-privilege-set privileges for authenticated EMPTY>
   <!ELEMENT unauthenticated EMPTY>
   <!ELEMENT property ANY>
   <!ELEMENT self EMPTY>

   <!ELEMENT invert principal>

   <!ELEMENT grant (privilege+)>
   <!ELEMENT deny (privilege+)>
   <!ELEMENT privilege ANY>

   <!ELEMENT protected EMPTY>

   <!ELEMENT inherited (href)>












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   <!-- DAV:acl-restrictions Property (Section 5.6) -->

   <!ELEMENT acl-restrictions (grant-only?, no-invert?,
    deny-before-grant?, required-principal?)>

   <!ELEMENT grant-only EMPTY>
   <!ELEMENT no-invert EMPTY>
   <!ELEMENT deny-before-grant EMPTY>

   <!ELEMENT required-principal
    (all? | authenticated? | unauthenticated? | self? | href*
    |property*)>

   <!-- DAV:inherited-acl-set Property (Section 5.7) -->

   <!ELEMENT inherited-acl-set (href*)>

   <!-- DAV:principal-collection-set Property (Section 5.8) -->

   <!ELEMENT principal-collection-set (href*)>

   <!-- principals
   should be carefully analyzed when deploying this protocol.  Access Control to
   the current-user-privilege-set property will involve a tradeoff of
   usability versus security.  When the current-user-privilege-set is
   visible, user interfaces are expected to provide enhanced information
   concerning permitted and restricted operations, yet this information
   may also indicate a vulnerability that could be exploited.
   Deployment of this protocol will need to evaluate this tradeoff in
   light of the requirements of the deployment environment.

12.3.  No Foreknowledge of Initial ACL

   In an effort to reduce protocol complexity, this protocol
   specification intentionally does not address the issue of how to
   manage or discover the initial ACL that is placed upon a resource
   when it is created.  The only way to discover the initial ACL is to
   create a new resource, then retrieve the value of the DAV:acl
   property.  This assumes the principal creating the resource also has
   been granted the DAV:read-acl privilege.

   As a result, it is possible that a principal could create a resource,
   and Existing Methods (Section 7) -->

   <!ELEMENT need-privileges (resource)* >
   <!ELEMENT then discover that its ACL grants privileges that are
   undesirable.  Furthermore, this protocol makes it possible (though
   unlikely) that the creating principal could be unable to modify the
   ACL, or even delete the resource.  Even when the ACL can be modified,
   there will be a short period of time when the resource ( href, privilege )

   <!-- exists with
   the initial ACL method preconditions (Section 8.1.1) -->

   <!ELEMENT no-ace-conflict EMPTY>
   <!ELEMENT no-protected-ace-conflict EMPTY>
   <!ELEMENT no-inherited-ace-conflict EMPTY>
   <!ELEMENT limited-number-of-aces EMPTY>
   <!ELEMENT grant-only EMPTY>
   <!ELEMENT no-invert EMPTY>
   <!ELEMENT deny-before-grant EMPTY>
   <!ELEMENT no-abstract EMPTY>
   <!ELEMENT not-supported-privilege EMPTY>
   <!ELEMENT missing-required-principal EMPTY>
   <!ELEMENT recognized-principal EMPTY>
   <!ELEMENT allowed-principal EMPTY> before its new ACL can be set.

   Several factors mitigate this risk.  Human principals are often aware
   of the default access permissions in their editing environments and
   take this into account when writing information.  Furthermore,
   default privilege policies are usually very conservative, limiting
   the privileges granted by the initial ACL.

13.  Authentication

   Authentication mechanisms defined for use with HTTP and WebDAV also
   apply to this WebDAV Access Control Protocol, in particular the Basic
   and Digest authentication mechanisms defined in [RFC2617].
   Implementation of the ACL spec requires that Basic authentication, if
   used, MUST only be supported over secure transport such as TLS.








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   <!-- REPORTs (Section 9) -->

   <!ELEMENT acl-principal-prop-set ANY>
   ANY value: a sequence of one or more elements, with at most one
   DAV:prop element.

   <!ELEMENT principal-match ((principal-property | self), prop?)>
   <!ELEMENT principal-property ANY>
   ANY value: an element whose value identifies a property. The
   expectation is             May 2004


14.  IANA Considerations

   This document uses the value of namespace defined by [RFC2518] for XML
   elements.  That is, this specification uses the named property typically contains
   an href element that contains "DAV:" URI namespace,
   previously registered in the URI schemes registry.  All other IANA
   considerations mentioned in [RFC2518] are also applicable to this
   specification.

15.  Acknowledgements

   This protocol is the collaborative product of a principal
   <!ELEMENT self EMPTY>

   <!ELEMENT principal-property-search ((property-search+), prop?) >
   <!ELEMENT property-search (prop, match) >
   <!ELEMENT match #PCDATA >

   <!ELEMENT principal-search-property-set (
    principal-search-property*) >
   <!ELEMENT principal-search-property (prop, description) >
   <!ELEMENT description #PCDATA >


Appendix B. the WebDAV Method Privilege Table (Normative) ACL design
   team: Bernard Chester, Geoff Clemm, Anne Hopkins, Barry Lind, Sean
   Lyndersay, Eric Sedlar, Greg Stein, and Jim Whitehead.  The following table of WebDAV methods (as defined in RFC 2518, 2616, authors
   are grateful for the detailed review and comments provided by Jim
   Amsden, Dylan Barrell, Gino Basso, Murthy Chintalapati, Lisa
   Dusseault, Stefan Eissing, Tim Ellison, Yaron Goland, Dennis
   Hamilton, Laurie Harper, Eckehard Hermann, Ron Jacobs, Chris Knight,
   Remy Maucherat, Larry Masinter, Joe Orton, Peter Raymond, and 3253) clarifies which privileges are required for access Keith
   Wannamaker.  We thank Keith Wannamaker for each
   method.  Note that the privileges listed, if denied, MUST cause initial text of the
   principal property search sections.  Prior work on WebDAV access to be denied.  However, given that a specific implementation
   MAY define an additional custom privilege to
   control access protocols has been performed by Yaron Goland, Paul Leach,
   Lisa Dusseault, Howard Palmer, and Jon Radoff.  We would like to
   existing methods, having all of
   acknowledge the indicated privileges does not
   mean that access will be granted.  Note that lack foundation laid for us by the authors of the indicated
   privileges does not imply that access will be denied, since a
   particular implementation may use a sub-privilege aggregated under DeltaV,
   WebDAV and HTTP protocols upon which this protocol is layered, and
   the indicated privilege to control access.  Privileges required refer
   to invaluable feedback from the current resource being processed unless otherwise specified. WebDAV working group.

16.  References

16.1.  Normative References

   [REC-XML]         Bray, T., Paoli, J., Sperberg-McQueen, C. and E.
                     Maler, "Extensible Markup Language (XML) 1.0
                     ((Third ed)", W3C REC REC-xml-20040204, February
                     2004, <http://www.w3.org/TR/2004/REC-xml-20040204>.

   [REC-XML-INFOSET] Cowan, J. and R. Tobin, "XML Information Set
                     (Second Edition)", W3C REC REC-xml-infoset-
                     20040204, February 2004,
                     <http://www.w3.org/TR/2004/REC-xml-infoset-
                     20040204/>.

   [REC-XML-NAMES]   Bray, T., Hollander, D. and A. Layman, "Namespaces
                     in XML", W3C REC REC-xml-names-19990114, January
                     1999, <http://www.w3.org/TR/1999/REC-xml-names-
                     19990114>.

   [RFC2119]         Bradner, S., "Key words for use in RFCs to Indicate
                     Requirement Levels", BCP 14, RFC 2119, March 1997.



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   [RFC2518]         Goland, Y., Whitehead, E., Faizi, A., Carter, S.
                     and D. Jensen, "HTTP Extensions for Distributed
                     Authoring -- WEBDAV", RFC 2518, February 1999.

   [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 22, 2004                 [Page 70]

Internet-Draft       WebDAV 1999.

   [RFC2617]         Franks, J., Hallam-Baker, P., Hostetler, J.,
                     Lawrence, S., Leach, P., Luotonen, A. and L.
                     Stewart, "HTTP Authentication: Basic and Digest
                     Access Control Protocol        December 2003


   +---------------------------------+---------------------------------+
   | METHOD                          | PRIVILEGES                      |
   +---------------------------------+---------------------------------+
   | GET                             | <D:read>                        |
   | HEAD                            | <D:read>                        |
   | OPTIONS                         | <D:read>                        |
   | PUT (target exists)             | <D:write-content> on target     |
   |                                 | resource                        |
   | PUT (no target exists)          | <D:bind> on parent collection   |
   |                                 | of target                       |
   | PROPPATCH                       | <D:write-properties>            |
   | ACL                             | <D:write-acl>                   |
   | PROPFIND                        | <D:read> (plus <D:read-acl> Authentication", RFC 2617, June 1999.

   [RFC3023]         Murata, M., St.Laurent, S. and |
   |                                 | <D:read-current-user-privilege- |
   |                                 | set> as needed)                 |
   | COPY (target exists)            | <D:read>, <D:write-content> D. Kohn, "XML Media
                     Types", RFC 3023, January 2001.

   [RFC3253]         Clemm, G., Amsden, J., Ellison, T., Kaler, C. and |
   |                                 | <D:write-properties> on target  |
   |                                 | resource                        |
   | COPY (no target exists)         | <D:read>, <D:bind> on target    |
   |                                 | collection                      |
   | MOVE (no target exists)         | <D:unbind> on source collection |
   |                                 |
                     J. Whitehead, "Versioning Extensions to WebDAV",
                     RFC 3253, March 2002.

   [RFC3530]         Shepler, S., Ed., Callaghan, B., Robinson, D.,
                     Thurlow, R., Beame, C., Eisler, M. and D. Noveck,
                     "Network File System (NFS) version 4 Protocol", RFC
                     3530, April 2003.

   [RFC3629]         Yergeau, F., "UTF-8, a transformation format of ISO
                     10646", STD 63, RFC 3629 November 2003.

16.2.  Informative References

   [RFC2251]         Wahl, M., Howes, T. and <D:bind> on target          |
   |                                 | collection                      |
   | MOVE (target exists)            | As above, plus <D:unbind> on    |
   |                                 | the target collection           |
   | DELETE                          | <D:unbind> on parent collection |
   | LOCK (target exists)            | <D:write-content>               |
   | LOCK (no target exists)         | <D:bind> on parent collection   |
   | MKCOL                           | <D:bind> on parent collection   |
   | UNLOCK                          | <D:unlock>                      |
   | CHECKOUT                        | <D:write-properties>            |
   | CHECKIN                         | <D:write-properties>            |
   | REPORT                          | <D:read> (on all referenced     |
   |                                 | resources)                      |
   | VERSION-CONTROL                 | <D:write-properties>            |
   | MERGE                           | <D:write-content>               |
   | MKWORKSPACE                     | <D:write-content> on parent     |
   |                                 | collection                      |
   | BASELINE-CONTROL                | <D:write-properties> S. Kille, "Lightweight
                     Directory Access Protocol (v3)", RFC 2251, December
                     1997.

   [RFC2255]         Howes, T. and        |
   |                                 | <D:write-content>               |
   | MKACTIVITY                      | <D:write-content> on parent     |
   |                                 | collection                      |
   +---------------------------------+---------------------------------+ M. Smith, "The LDAP URL Format", RFC
                     2255, December 1997.

   [UNICODE4]        The Unicode Consortium, "The Unicode Standard -
                     Version 4.0", Addison-Wesley , August 2003,
                     <http://www.unicode.org/versions/Unicode4.0.0/>.
                     ISBN 0321185781.









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Appendix C. Resolved issues (to A. WebDAV XML Document Type Definition Addendum

   All XML elements defined in this Document Type Definition (DTD)
   belong to the DAV namespace. This DTD should be removed by RFC Editor before
            publication) viewed as an addendum
   to the DTD provided in [RFC2518], section 23.1.

   <!-- Privileges -- (Section 3)>

   <!ELEMENT read EMPTY>
   <!ELEMENT write EMPTY>
   <!ELEMENT write-properties EMPTY>
   <!ELEMENT write-content EMPTY>
   <!ELEMENT unlock EMPTY>
   <!ELEMENT read-acl EMPTY>
   <!ELEMENT read-current-user-privilege-set EMPTY>
   <!ELEMENT write-acl EMPTY>
   <!ELEMENT bind EMPTY>
   <!ELEMENT unbind EMPTY>
   <!ELEMENT all EMPTY>

   <!-- Principal Properties (Section 4) -->

   <!ELEMENT principal EMPTY>

   <!ELEMENT alternate-URI-set (href*)>
   <!ELEMENT principal-URL (href)>
   <!ELEMENT group-member-set (href*)>
   <!ELEMENT group-membership (href*)>

   <!-- Access Control Properties (Section 5) -->

   <!-- DAV:owner Property (Section 5.1) -->

   <!ELEMENT owner (href?)>

   <!-- DAV:group Property (Section 5.2) -->

   <!ELEMENT group (href?)>

   <!-- DAV:supported-privilege-set Property (Section 5.3) -->

   <!ELEMENT supported-privilege-set (supported-privilege*)>
   <!ELEMENT supported-privilege
    (privilege, abstract?, description, supported-privilege*)>

   <!ELEMENT privilege ANY>
   <!ELEMENT abstract EMPTY>
   <!ELEMENT description #PCDATA>



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   Issues that were either rejected or resolved in this version of this
   document.

C.1 ED_references_names

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001711.html>

   julian.reschke@greenbytes.de (2003-11-03): Replace "Informative
   References" by "Informational References".

   Resolution (2003-11-06): Section title renamed from "Informative
   References" to "Informational References" (no change tracking).

C.2 ED_RFC2386

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001711.html>

   julian.reschke@greenbytes.de (2003-11-03): RFC2386 is listed, but not
   mentioned in the spec.

   Resolution (2003-11-06): Entry RFC2386 removed from references (no
   change tracking).

C.3 ED_example_host_names

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001719.html>

   julian.reschke@greenbytes.de (2003-11-06): When changing the host
   names, we forgot to also update user names that appear in
   "Authorization" headers (such as "gclemm@webdav.org"). I'd recommend
   to just replace "@webdav.org" with "@example.com". Also fix broken
   realms (always say "users@example.com").

   Resolution (2003-11-06): All realms changed to "users@example.com".

C.4 ED_authors_list

   Type: edit

   geoffrey.clemm@us.ibm.com (2003-11-06): Remove Anne Hopkins from
   authors list (keep her name in the Acknowledgements section).             May 2004


   <!-- DAV:current-user-privilege-set Property (Section 5.4) -->

   <!ELEMENT current-user-privilege-set (privilege*)>

   <!-- DAV:acl Property (Section 5.5) -->

   <!ELEMENT acl (ace)* >
   <!ELEMENT ace ((principal | invert), (grant|deny), protected?,
    inherited?)>

   <!ELEMENT principal (href)
    | all | authenticated | unauthenticated
    | property | self)>

   <!ELEMENT all EMPTY>
   <!ELEMENT authenticated EMPTY>
   <!ELEMENT unauthenticated EMPTY>
   <!ELEMENT property ANY>
   <!ELEMENT self EMPTY>

   <!ELEMENT invert principal>

   <!ELEMENT grant (privilege+)>
   <!ELEMENT deny (privilege+)>
   <!ELEMENT privilege ANY>

   <!ELEMENT protected EMPTY>

   <!ELEMENT inherited (href)>

   <!-- DAV:acl-restrictions Property (Section 5.6) -->

   <!ELEMENT acl-restrictions (grant-only?, no-invert?,
    deny-before-grant?, required-principal?)>

   <!ELEMENT grant-only EMPTY>
   <!ELEMENT no-invert EMPTY>
   <!ELEMENT deny-before-grant EMPTY>

   <!ELEMENT required-principal
    (all? | authenticated? | unauthenticated? | self? | href*
    |property*)>

   <!-- DAV:inherited-acl-set Property (Section 5.7) -->

   <!ELEMENT inherited-acl-set (href*)>

   <!-- DAV:principal-collection-set Property (Section 5.8) -->



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   geoffrey.clemm@us.ibm.com (2003-12-20): Add Julian Reschke to authors
   list.

   Resolution (2003-12-20): Removed Anne Hopkins from authors list (both
   in front page and in "authors" section). Added Julian Reschke to
   authors list.

C.5 ED_non_ASCII

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001712.html>

   julian.reschke@greenbytes.de (2003-11-03): some non-ASCII characters
   (long dashes and quotes) are present

   Resolution (2003-11-04): Fixed in Sections 3.1, 3.3, 3.4, 6, 7.1.1.

C.6 ED_artwork_line_width

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001712.html>

   julian.reschke@greenbytes.de (2003-11-03): In request/responses/DTDs,
   the line width sometimes exceeds what's allowed in an RFC (I think 72
   characters).

   Resolution (2003-11-04): Added line breaks and/or changed indention
   in some of the figures (no change tracking).

C.7 ED_xml_typos

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001712.html>

   julian.reschke@greenbytes.de (2003-11-03): There were a few typos in
   the XML examples

   Resolution (2003-11-04): Several XML message bodies fixed (no change
   tracking).

C.8 1_ref_options

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001718.html>



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   <!ELEMENT principal-collection-set (href*)>

   <!-- Access Control Protocol        December 2003


   julian.reschke@greenbytes.de (2003-11-04): "Client discovery and Existing Methods (Section 7) -->

   <!ELEMENT need-privileges (resource)* >
   <!ELEMENT resource ( href, privilege )

   <!-- ACL method preconditions (Section 8.1.1) -->

   <!ELEMENT no-ace-conflict EMPTY>
   <!ELEMENT no-protected-ace-conflict EMPTY>
   <!ELEMENT no-inherited-ace-conflict EMPTY>
   <!ELEMENT limited-number-of-aces EMPTY>
   <!ELEMENT grant-only EMPTY>
   <!ELEMENT no-invert EMPTY>
   <!ELEMENT deny-before-grant EMPTY>
   <!ELEMENT no-abstract EMPTY>
   <!ELEMENT not-supported-privilege EMPTY>
   <!ELEMENT missing-required-principal EMPTY>
   <!ELEMENT recognized-principal EMPTY>
   <!ELEMENT allowed-principal EMPTY>

   <!-- REPORTs (Section 9) -->

   <!ELEMENT acl-principal-prop-set ANY>
   ANY value: a sequence of
   access control capability using OPTIONS is described in Section 7.1."
   The reference should be to "7.2".

   Resolution (2003-11-04): Replaced "7.1" one or more elements, with "7.2"

C.9 3.2_ED_RFC2518

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001711.html>

   julian.reschke@greenbytes.de (2003-11-03): Fix references
   ("[WEBDAV]") to RFC2518.

   Resolution (2003-11-05): Replaced "[WEBDAV]" by "[RFC2518]".

C.10 3.3_ED_priv_section_titles

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001741.html>

   julian.reschke@greenbytes.de (2003-11-07): Section titles for
   DAV:write-properties, DAV:write-content and DAV:unlock missing word
   "Privilege".

   Resolution (2003-11-07): Added "Privilege" to the section titles (no
   change tracking).

C.11 3.4_write-content-description

   Type: change

   <http://mailman.webdav.org/pipermail/acl/2003-November/001757.html>

   csharp@mac.com (2003-11-18): If DAV:write-content is just at most one
   DAV:prop element.

   <!ELEMENT principal-match ((principal-property | self), prop?)>
   <!ELEMENT principal-property ANY>
   ANY value: an
   aggregate of DAV:bind and DAV:unbind why doesn't it state that "the
   client can safely expect that no other privilege needs to be granted
   to have access to MKCOL,PUT, DELETE,MOVE, COPY"? If it element whose value identifies a property. The
   expectation is not an
   aggregate why does it exist?

   Resolution (2003-11-18): Update description the value of DAV:write-content so
   that it doesn't refer to collection membership; clarify the
   distinction between PUT to an existing reource (modifying content)
   and PUT on named property typically contains
   an unmapped URI (creating a new resource, requiring
   privileges on href element that contains the parent collection). Define aggregation URI of DAV:bind
   and DAV:unbind in 3.12. a principal
   <!ELEMENT self EMPTY>

   <!ELEMENT principal-property-search ((property-search+), prop?) >
   <!ELEMENT property-search (prop, match) >
   <!ELEMENT match #PCDATA >

   <!ELEMENT principal-search-property-set (
    principal-search-property*) >
   <!ELEMENT principal-search-property (prop, description) >
   <!ELEMENT description #PCDATA >








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C.12 3.12_ED_bad_reference

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001712.html>

   julian.reschke@greenbytes.de (2003-11-03): section 3.12 talks about
   "defined above in Sections 3.1-3.9". I think this should be "defined
   above in Sections 3.1-3.11" or simply "defined in above sections"

   geoffrey.clemm@us.ibm.com (2003-11-06): For the section 3.12 issue,
   I'd prefer to change it to say "Sections 3.1-3.10" (the DAV:all
   privilege from section 3.11 should not be included in another
   privilege).

   Resolution (2003-11-06): Replace "Sections 3.1-3.9" by "Sections
   3.1-3.10".

C.13 4.1_ED_RFC2589

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001711.html>

   julian.reschke@greenbytes.de (2003-11-03): text quotes RFC2589
   ("Lightweight Directory Access Protocol (v3): Extensions for Dynamic
   Directory Services"), but references section has RFC2251
   ("Lightweight Directory Access Protocol (v3)")

   geoffrey.clemm@us.ibm.com (2003-11-06): The LDAP reference should be
   RFC2251 (not RFC2589).

   Resolution (2003-11-06): Replaced "[RFC2589]" by "[RFC2251]".

C.14 5.1_owner_group_details

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001737.html>

   julian.reschke@greenbytes.de (2003-11-07): State that DAV:owner and
   DAV:group MAY be protected. Also state that they MAY be empty if the
   server can't provide the information.

   Resolution (2003-11-08): Added paragraphs stating both for both
   properties.





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Appendix B. WebDAV Access Control Protocol        December 2003


C.15 5.1_owner_href_optional

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001728.html>

   julian.reschke@greenbytes.de (2003-11-06): href element should be
   optional in case the server doesn't have owner information.

   Resolution (2003-11-06): Updated DTD fragment.

C.16 5.1.2_responsedescription

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001737.html>

   julian.reschke@greenbytes.de (2003-11-07): Add DAV:error element to
   DAV:responsedescription Method Privilege Table (Normative)

   The following table of WebDAV methods (as defined in example RFC 2518, 2616,
   and update explanation.

   Resolution (2003-11-08): DAV:error subelement added to
   DAV:responsedescription in response.

C.17 5.5.5_ED_section_numbering

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001712.html>

   julian.reschke@greenbytes.de (2003-11-03): missing section numbering 3253) clarifies which privileges are required for "Example: Retrieving DAV:acl-restrictions"

   Resolution (2003-11-04): Added section number (no change tracking).

C.18 5.8_unbind

   Type: change

   <http://mailman.webdav.org/pipermail/acl/2003-November/001714.html>

   julian.reschke@greenbytes.de (2003-11-03): A:unbind: mismatch between
   XML response and privilege tree in figure.

   eric.sedlar@oracle.com (2003-11-04): The change in access for each
   method.  Note that the XML response
   should privileges listed, if denied, MUST cause
   access to be rolled back.  "delete" is denied.  However, given that a specific implementation
   MAY define an additional custom privilege in the
   example.

   Resolution (2003-11-04): Changed example response back to use



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   A:delete.

C.19 6_ED_RFC3010

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001711.html>

   julian.reschke@greenbytes.de (2003-11-03): Fix references ("[NFSV4]")
   to RFC3010.

   Resolution (2003-11-11): Replaced "[NVSV4]" by "[RFC3530]" (which
   obsoletes RFC3010).

C.20 6_group_property

   Type: change

   <http://mailman.webdav.org/pipermail/acl/2003-November/001713.html>

   julian.reschke@greenbytes.de (2003-11-03): in section 6 control access to
   existing methods, having all of the following
   example is used...: <D:principal><D:property><D:group/></
   D:property></D:principal> However, there is no such thing as a
   DAV:group property. I'm indicated privileges does not sure what the best fix for this would
   be... If the "group" thing is essential, this may
   mean that an
   important live property is missing? If it's access will be granted.  Note that lack of the indicated
   privileges does not essential, can this
   example rewritten without imply that property? (Or with a non-DAV: property
   from an example namespace?)

   geoffry.clemm@us.ibm.com (2003-11-06): Proposal to add DAV:group
   property.

   eric.sedlar@oracle.com (2003-11-06): I have a problem with adding
   this property.  If access will be denied, since a
   particular vendor wants implementation may use a sub-privilege aggregated under
   the indicated privilege to add <vendor:group>
   that's great, but I think we are going control access.  Privileges required refer
   to have minimal
   interoperability with this.  We discussed this before the current resource being processed unless otherwise specified.






































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   +---------------------------------+---------------------------------+
   | METHOD                          | PRIVILEGES                      |
   +---------------------------------+---------------------------------+
   | GET                             | <D:read>                        |
   | HEAD                            | <D:read>                        |
   | OPTIONS                         | <D:read>                        |
   | PUT (target exists)             | <D:write-content> on target     |
   |                                 | resource                        |
   | PUT (no target exists)          | <D:bind> on parent collection   |
   |                                 | of target                       |
   | PROPPATCH                       | <D:write-properties>            |
   | ACL                             | <D:write-acl>                   |
   | PROPFIND                        | <D:read> (plus <D:read-acl> and |
   |                                 | <D:read-current-user-privilege- |
   |                                 | set> as needed)                 |
   | COPY (target exists)            | <D:read>, <D:write-content> and |
   |                                 | <D:write-properties> on target  |
   |                                 | resource                        |
   | COPY (no target exists)         | <D:read>, <D:bind> on target    |
   |                                 | collection                      |
   | MOVE (no target exists)         | <D:unbind> on source collection |
   |                                 | and weren't
   able to find anyone who actually wanted to use this.

   Resolution (2003-11-06): Added section 5.2 ("DAV:group"). Subsequent
   sections renumbered.

C.21 5.5.2_TYPO

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-October/001691.html>

   peter.nevermann@softwareag.com (2003-10-22): Precondition



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   DAV:no-invert should refer to section 5.5.2 for <D:bind> on target          |
   |                                 | collection                      |
   | MOVE (target exists)            | As above, plus <D:unbind> on    |
   |                                 | the DAV:no-invert
   constraint ... not 6.3.4.

   Resolution (2003-11-04): Reference fixed.

C.22 9.4_ED_reference_casemap

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001711.html>

   julian.reschke@greenbytes.de (2003-11-03): Update [CaseMap] reference
   to "[UNICODE4]      The Unicode Consortium, "The Unicode Standard -
   Version 4.0", Addison-Wesley, August 2003. ISBN 0321185781" (section
   5.18).

   Resolution (2003-11-06): Removed "[CaseMap]" from references, add
   "[UNICODE]" to references. Cite using '...especially Section 2.3
   ("Caseless Matching"), Section 5.18, Subsection "Caseless
   Matching"...'.

C.23 11_ED_RFC2279

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001711.html>

   julian.reschke@greenbytes.de (2003-11-03): Replace [UTF-8] by
   [RFC2279] for consistency.

   Resolution (2003-11-11): Reference name changed both in text and
   references section to RFC3629 (update of RFC2279).

C.24 A_ED_appendices

   Type: edit

   <http://mailman.webdav.org/pipermail/acl/2003-November/001712.html>

   julian.reschke@greenbytes.de (2003-11-03): Appendices should indeed
   be appendices, not a regular section (see
   draft-rfc-editor-rfc2223bis).

   Resolution (2003-11-04): Moved Section 19.1 to Appendix A target collection           |
   | DELETE                          | <D:unbind> on parent collection |
   | LOCK (target exists)            | <D:write-content>               |
   | LOCK (no target exists)         | <D:bind> on parent collection   |
   | MKCOL                           | <D:bind> on parent collection   |
   | UNLOCK                          | <D:unlock>                      |
   | CHECKOUT                        | <D:write-properties>            |
   | CHECKIN                         | <D:write-properties>            |
   | REPORT                          | <D:read> (on all referenced     |
   |                                 | resources)                      |
   | VERSION-CONTROL                 | <D:write-properties>            |
   | MERGE                           | <D:write-content>               |
   | MKWORKSPACE                     | <D:write-content> on parent     |
   |                                 | collection                      |
   | BASELINE-CONTROL                | <D:write-properties> and Section
   19.2 to Appendix B.        |
   |                                 | <D:write-content>               |
   | MKACTIVITY                      | <D:write-content> on parent     |
   |                                 | collection                      |
   +---------------------------------+---------------------------------+








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Index

   A
      ACL method  41  40

   C
      Condition Names
         DAV:allowed-principal (pre)  43  42
         DAV:deny-before-grant (pre)  43  41
         DAV:grant-only (pre)  43  41
         DAV:limited-number-of-aces (pre)  43  41
         DAV:missing-required-principal (pre)  43  42
         DAV:no-abstract (pre)  43  41
         DAV:no-ace-conflict (pre)  42  41
         DAV:no-inherited-ace-conflict (pre)  42  41
         DAV:no-invert (pre)  43  41
         DAV:no-protected-ace-conflict (pre)  42  41
         DAV:not-supported-privilege (pre)  43  42
         DAV:number-of-matches-within-limits (post)  50, 55  48, 53
         DAV:recognized-principal (pre)  43  42

   D
      DAV header
         compliance class 'access-control'  40  38
      DAV:acl property  24  23
      DAV:acl-principal-prop-set report  49  48
      DAV:acl-restrictions property  28  27
      DAV:all privilege  13
      DAV:allowed-principal precondition  43  42
      DAV:alternate-URI-set property  14
      DAV:bind privilege  13  12
      DAV:current-user-privilege-set property  22  21
      DAV:deny-before-grant precondition  43  41
      DAV:grant-only precondition  43  41
      DAV:group property  18
      DAV:group-member-set property  15  14
      DAV:group-membership property  15  14
      DAV:inherited-acl-set property  31  29
      DAV:limited-number-of-aces precondition  43  41
      DAV:missing-required-principal precondition  43  42
      DAV:no-abstract precondition  43  41
      DAV:no-ace-conflict precondition  42  41
      DAV:no-inherited-ace-conflict precondition  42  41
      DAV:no-invert precondition  43  41
      DAV:no-protected-ace-conflict precondition  42  41
      DAV:not-supported-privilege precondition  43  42
      DAV:number-of-matches-within-limits postcondition  50, 55  48, 53
      DAV:owner property  16  15



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      DAV:principal resource type  14  13
      DAV:principal-collection-set property  31  30
      DAV:principal-match report  51  50
      DAV:principal-property-search  53  51
      DAV:principal-search-property-set  58  56
      DAV:principal-URL property  15  14
      DAV:read privilege  10
      DAV:read-acl privilege  12  11
      DAV:read-current-user-privilege-set privilege  12
      DAV:recognized-principal precondition  43  42
      DAV:supported-privilege-set property  19  18
      DAV:unbind privilege  13  12
      DAV:unlock privilege  12  11
      DAV:write privilege  11  10
      DAV:write-acl privilege  13  12
      DAV:write-content privilege  11  10
      DAV:write-properties privilege  11  10

   M
      Methods
         ACL  41  40

   P
      Privileges
         DAV:all  13
         DAV:bind  13  12
         DAV:read  10
         DAV:read-acl  12  11
         DAV:read-current-user-privilege-set  12
         DAV:unbind  13
      DAV:unlock  12
      DAV:write
         DAV:unlock  11
         DAV:write  10
         DAV:write-acl  13  12
         DAV:write-content  11
         DAV:write-properties  11  10
      Properties
         DAV:acl  24  23
         DAV:acl-restrictions  28  27
         DAV:alternate-URI-set  14
         DAV:current-user-privilege-set  22  21
         DAV:group  18
         DAV:group-member-set  15  14
         DAV:group-membership  15  14
         DAV:inherited-acl-set  31  29
         DAV:owner  16  15
         DAV:principal-collection-set  31  30
         DAV:principal-URL  15  14
         DAV:supported-privilege-set  19  18



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   R
      Reports
         DAV:acl-principal-prop-set  49  47
         DAV:principal-match  51  49
         DAV:principal-property-search  53  51
         DAV:principal-search-property-set  58  56
      Resource Types
         DAV:principal  14  13

Authors' Addresses

   Geoffrey Clemm
   IBM
   20 Maguire Road
   Lexington, MA  02421

   EMail: geoffrey.clemm@us.ibm.com


   Julian F. Reschke
   greenbytes GmbH
   Salzmannstrasse 152
   Muenster, NW  48159
   Germany

   EMail: julian.reschke@greenbytes.de


   Eric Sedlar
   Oracle Corporation
   500 Oracle Parkway
   Redwood Shores, CA  94065

   EMail: eric.sedlar@oracle.com


   Jim Whitehead
   U.C. Santa Cruz, Dept. of Computer Science
   1156 High Street
   Santa Cruz, CA  95064

   EMail: ejw@cse.ucsc.edu









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   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
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Acknowledgment at ietf-ipr@ietf.org.

Acknowledgement

   Funding for the RFC Editor function is currently provided by the
   Internet Society.









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