INTERNET-DRAFT Geoffrey Clemm,
Network Working Group G. Clemm
Internet-Draft IBM
draft-ietf-webdav-acl-12 Anne Hopkins, Microsoft Corporation
Eric Sedlar,
Expires: June 22, 2004 J. Reschke
greenbytes
E. Sedlar
Oracle Corporation
Jim Whitehead,
J. Whitehead
U.C. Santa Cruz
Expires April 10, 2004 October 10,
December 23, 2003
WebDAV Access Control Protocol
draft-ietf-webdav-acl-13
Status of this Memo
This document is an Internet-Draft and is subject to in full conformance with
all provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on June 22, 2004.
Copyright Notice
Copyright (C) The Internet Society (2003). 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
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 http://www.example.com/acl/, [2], and
http://www.ics.uci.edu/pub/ietf/webdav/.
Clemm, Hopkins, Sedlar, Whitehead
[Page 1] [3].
Table of Contents
1 INTRODUCTION.................................................4
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1 Terms......................................................6 Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.2 Notational Conventions.....................................7
2 PRINCIPALS...................................................7
3 PRIVILEGES...................................................8 Conventions . . . . . . . . . . . . . . . . . . . 8
2. Principals . . . . . . . . . . . . . . . . . . . . . . . . . 8
3. Privileges . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1 DAV:read Privilege.........................................9 Privilege . . . . . . . . . . . . . . . . . . . . . 10
3.2 DAV:write Privilege........................................9 Privilege . . . . . . . . . . . . . . . . . . . . 11
3.3 DAV:write-properties.......................................9 DAV:write-properties Privilege . . . . . . . . . . . . . . . 11
3.4 DAV:write-content.........................................10 DAV:write-content Privilege . . . . . . . . . . . . . . . . 11
3.5 DAV:unlock................................................10
3.6 DAV:read-acl Privilege....................................10
3.7 DAV:read-current-user-privilege-set Privilege.............10
3.8 DAV:write-acl Privilege...................................11
3.9 DAV:unlock Privilege . . . . . . . . . . . . . . . . . . . . 12
3.6 DAV:read-acl Privilege . . . . . . . . . . . . . . . . . . . 12
3.7 DAV:read-current-user-privilege-set Privilege . . . . . . . 12
3.8 DAV:write-acl Privilege . . . . . . . . . . . . . . . . . . 13
3.9 DAV:bind Privilege........................................11 Privilege . . . . . . . . . . . . . . . . . . . . . 13
3.10 DAV:unbind Privilege.....................................11 Privilege . . . . . . . . . . . . . . . . . . . . 13
3.11 DAV:all Privilege........................................11 Privilege . . . . . . . . . . . . . . . . . . . . . 13
3.12 Aggregation of Predefined Privileges.....................11
4 PRINCIPAL PROPERTIES........................................12 Privileges . . . . . . . . . . . . 13
4. Principal Properties . . . . . . . . . . . . . . . . . . . . 14
4.1 DAV:alternate-URI-set.....................................12 DAV:alternate-URI-set . . . . . . . . . . . . . . . . . . . 14
4.2 DAV:principal-URL.........................................12 DAV:principal-URL . . . . . . . . . . . . . . . . . . . . . 15
4.3 DAV:group-member-set......................................12 DAV:group-member-set . . . . . . . . . . . . . . . . . . . . 15
4.4 DAV:group-membership......................................13
5 ACCESS CONTROL PROPERTIES...................................13
5.1 DAV:owner.................................................13
5.1.1 DAV:group-membership . . . . . . . . . . . . . . . . . . . . 15
5. Access Control Properties . . . . . . . . . . . . . . . . . 15
5.1 DAV:owner . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.1.1 Example: Retrieving DAV:owner..........................13 DAV:owner . . . . . . . . . . . . . . . 16
5.1.2 Example: An Attempt to Set DAV:owner...................14 DAV:owner . . . . . . . . . . . . 17
5.2 DAV:supported-privilege-set...............................15
5.2.1 DAV:group . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.3 DAV:supported-privilege-set . . . . . . . . . . . . . . . . 19
5.3.1 Example: Retrieving a List of Privileges Supported on a Resource.............................................16
5.3 DAV:current-user-privilege-set............................18
5.3.1
Resource . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.4 DAV:current-user-privilege-set . . . . . . . . . . . . . . . 22
5.4.1 Example: Retrieving the User's Current Set of Assigned
Privileges...................................................19
5.4 DAV:acl...................................................20
5.4.1 ACE Principal..........................................20
5.4.2 ACE Grant and Deny.....................................21
5.4.3 ACE Protection.........................................21
5.4.4 ACE Inheritance........................................21
5.4.5 Example: Retrieving a Resource's Access Control List ..22
Privileges . . . . . . . . . . . . . . . . . . . . . . . . . 23
5.5 DAV: acl-restrictions.....................................23
5.5.1 DAV:grant-only.........................................23
5.5.2 DAV:no-invert ACE Constraint...........................24
5.5.3 DAV:deny-before-grant..................................24
5.5.4 Required Principals....................................24
Example: Retrieving DAV:acl-restrictions............. ...24
5.6 DAV:inherited-acl-set.....................................25
5.7 DAV:principal-collection-set..............................25
5.7.1 Example: Retrieving DAV:principal-collection-set.......26
5.8 Example: PROPFIND to retrieve access control properties...27
Clemm, Hopkins, Sedlar, Whitehead [Page 2]
6 ACL EVALUATION..............................................30
7 ACCESS CONTROL AND EXISTING METHODS.........................31
7.1 ANY HTTP METHOD...........................................32
7.1.1 Error Handling.........................................32
7.2 OPTIONS...................................................32
7.2.1 Example - OPTIONS......................................33
7.3 MOVE......................................................33
7.4 COPY......................................................33
7.5 LOCK......................................................33
8 ACCESS CONTROL METHODS......................................33
8.1 ACL.......................................................33
8.1.1 ACL Preconditions......................................34
8.1.2 Example: the ACL method................................35
8.1.3 Example: ACL method failure due to protected DAV:acl . . . . . . . . . . . . . . . . . . . . . . . . . . 24
5.5.1 ACE
conflict...............................................36
8.1.4 Example: ACL method failure due to an inherited Principal . . . . . . . . . . . . . . . . . . . . . . . 24
5.5.2 ACE
conflict...............................................37
8.1.5 Example: ACL method failure due to an attempt to set
grant Grant and deny in a single ACE.........................38
9 ACCESS CONTROL REPORTS......................................39
9.1 REPORT Method.............................................39
9.2 DAV:acl-principal-prop-set Report.........................39
9.2.1 Example: DAV:acl-principal-prop-set Report.............40
9.3 DAV:principal-match REPORT................................42
9.3.1 Example: DAV:principal-match REPORT....................43
9.4 DAV:principal-property-search REPORT......................43
9.4.1 Matching...............................................45
9.4.2 Example: successful DAV:principal-property-search
REPORT.................................................46
9.5 DAV:principal-search-property-set REPORT..................48
9.5.1 Deny . . . . . . . . . . . . . . . . . . . . . 26
5.5.3 ACE Protection . . . . . . . . . . . . . . . . . . . . . . . 26
5.5.4 ACE Inheritance . . . . . . . . . . . . . . . . . . . . . . 26
5.5.5 Example: DAV:principal-search-property-set REPORT......49
10 XML PROCESSING............................................50
11 INTERNATIONALIZATION CONSIDERATIONS.......................50
12 SECURITY CONSIDERATIONS...................................51
12.1 Increased Risk of Compromised Users......................51
12.2 Risks of the DAV:read-acl Retrieving a Resource's Access Control List . . . . 26
5.6 DAV:acl-restrictions . . . . . . . . . . . . . . . . . . . . 28
5.6.1 DAV:grant-only . . . . . . . . . . . . . . . . . . . . . . . 29
5.6.2 DAV:no-invert ACE Constraint . . . . . . . . . . . . . . . . 29
5.6.3 DAV:deny-before-grant . . . . . . . . . . . . . . . . . . . 29
5.6.4 Required Principals . . . . . . . . . . . . . . . . . . . . 29
5.6.5 Example: Retrieving DAV:acl-restrictions . . . . . . . . . . 30
5.7 DAV:inherited-acl-set . . . . . . . . . . . . . . . . . . . 31
5.8 DAV:principal-collection-set . . . . . . . . . . . . . . . . 31
5.8.1 Example: Retrieving DAV:principal-collection-set . . . . . . 32
5.9 Example: PROPFIND to retrieve access control properties . . 33
6. ACL Evaluation . . . . . . . . . . . . . . . . . . . . . . . 37
7. Access Control and existing methods . . . . . . . . . . . . 39
7.1 Any HTTP method . . . . . . . . . . . . . . . . . . . . . . 39
7.1.1 Error Handling . . . . . . . . . . . . . . . . . . . . . . . 39
7.2 OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . 40
7.2.1 Example - OPTIONS . . . . . . . . . . . . . . . . . . . . . 40
7.3 MOVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
7.4 COPY . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
7.5 LOCK . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
8. Access Control Methods . . . . . . . . . . . . . . . . . . . 41
8.1 ACL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
8.1.1 ACL Preconditions . . . . . . . . . . . . . . . . . . . . . 42
8.1.2 Example: the ACL method . . . . . . . . . . . . . . . . . . 44
8.1.3 Example: ACL method failure due to protected ACE conflict . 45
8.1.4 Example: ACL method failure due to an inherited ACE
conflict . . . . . . . . . . . . . . . . . . . . . . . . . . 46
8.1.5 Example: ACL method failure due to an attempt to set
grant and deny in a single ACE . . . . . . . . . . . . . . . 47
9. Access Control Reports . . . . . . . . . . . . . . . . . . . 48
9.1 REPORT Method . . . . . . . . . . . . . . . . . . . . . . . 48
9.2 DAV:acl-principal-prop-set Report . . . . . . . . . . . . . 49
9.2.1 Example: DAV:acl-principal-prop-set Report . . . . . . . . . 50
9.3 DAV:principal-match REPORT . . . . . . . . . . . . . . . . . 51
9.3.1 Example: DAV:principal-match REPORT . . . . . . . . . . . . 52
9.4 DAV:principal-property-search REPORT . . . . . . . . . . . . 53
9.4.1 Matching . . . . . . . . . . . . . . . . . . . . . . . . . . 56
9.4.2 Example: successful DAV:principal-property-search REPORT . . 56
9.5 DAV:principal-search-property-set REPORT . . . . . . . . . . 58
9.5.1 Example: DAV:principal-search-property-set REPORT . . . . . 60
10. XML Processing . . . . . . . . . . . . . . . . . . . . . . . 61
11. Internationalization Considerations . . . . . . . . . . . . 61
12. Security Considerations . . . . . . . . . . . . . . . . . . 62
12.1 Increased Risk of Compromised Users . . . . . . . . . . . . 62
12.2 Risks of the DAV:read-acl and
DAV:current-user-privilege-set Privileges . . . . . . . . . 63
12.3 No Foreknowledge of Initial ACL . . . . . . . . . . . . . . 63
13. Authentication . . . . . . . . . . . . . . . . . . . . . . . 64
14. IANA Considerations . . . . . . . . . . . . . . . . . . . . 64
15. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 64
Normative References . . . . . . . . . . . . . . . . . . . . 64
Informative References . . . . . . . . . . . . . . . . . . . 65
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 66
A. WebDAV XML Document Type Definition Addendum . . . . . . . . 67
B. WebDAV Method Privilege Table (Normative) . . . . . . . . . 70
C. Resolved issues (to be removed by RFC Editor before
publication) . . . . . . . . . . . . . . . . . . . . . . . . 71
C.1 ED_references_names . . . . . . . . . . . . . . . . . . . . 72
C.2 ED_RFC2386 . . . . . . . . . . . . . . . . . . . . . . . . . 72
C.3 ED_example_host_names . . . . . . . . . . . . . . . . . . . 72
C.4 ED_authors_list . . . . . . . . . . . . . . . . . . . . . . 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
DAV:current-user-privilege-set Privileges................51
12.3 No Foreknowledge of Initial ACL..........................52
13 AUTHENTICATION............................................52
14 IANA CONSIDERATIONS.......................................52
15 INTELLECTUAL PROPERTY.....................................53
16 ACKNOWLEDGEMENTS..........................................53
17 REFERENCES................................................53
17.1 Normative References.....................................53
Clemm, Hopkins, Sedlar, Whitehead [Page 3]
17.2 Informational References.................................54
18 AUTHORS' ADDRESSES........................................55
19 APPENDICES................................................56
19.1 WebDAV XML Document Type Definition Addendum.............56
19.2 WebDAV Method Privilege Table (Normative)................58
1 INTRODUCTION Copyright Statements . . . . . . . 82
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 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 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 http://www.example.com/people/
Greg.Stein also affects the principal at http://www.example.com/u/256432. 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.
Clemm, Hopkins, Sedlar, Whitehead [Page 4]
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
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
computational agents (principals), and groups of these.
Clemm, Hopkins, Sedlar, Whitehead [Page 5]
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 Section 6. Client discovery of access control capability
using OPTIONS is described in Section 7.1. 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 (Section 19.1) (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
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 . 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)
(non-abstract) privileges for a particular principal.
Clemm, Hopkins, Sedlar, Whitehead [Page 6]
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 of an
XML fragment, the string "DAV:" will be prefixed to the element name.
2 PRINCIPALS
2. Principals
A principal is a network resource that represents a distinct human or
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 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 an implementation SHOULD support
PROPFIND and MAY support PROPPATCH to access and modify information
about a principal, it is not required to do so.
A principal resource may be a group, where a group is a principal
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 of a group, they also match the group.
Membership in a group is recursive, so if a principal is a member of
group GRPA, and GRPA is a member of group GRPB, then the principal is
also a member of GRPB.
Clemm, Hopkins, Sedlar, Whitehead [Page 7]
3 PRIVILEGES
3. Privileges
Ability to perform a given method on a resource MUST be controlled by
one or more privileges. Authors of protocol extensions that define
new HTTP methods SHOULD specify which privileges (by defining new
privileges, or mapping to ones below) are required to perform the
method. A principal with no privileges to a resource MUST be denied
any HTTP access to that resource, unless the principal matches an ACE
constructed using the DAV:all, DAV:authenticated, or
DAV:unauthenticated pseudo-principals (see Section 5.4.1). 5.5.1). Servers
MUST report a 403 "Forbidden" error if access is denied, except in
the case where the privilege restricts the ability to know the
resource exists, in 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 principal is granted or
denied an aggregate privilege, it is semantically equivalent to
granting or denying each of the aggregated privileges individually.
For example, an implementation may define add-
member add-member and
remove-member privileges that control the ability to add and remove a
member of a group. Since these privileges control the ability to
update the state of a group, these privileges would be aggregated by
the DAV:write privilege on a 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 given resource, in
which case they cannot be set in an ACE on that resource. Aggregate
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 the
privileges defined in this specification. For example, if a server
is incapable of separating the read resource capability from the 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 non-abstract aggregate privilege (say,
read-all) that holds DAV:read, and DAV:read-acl. In this way, it is
possible to set the aggregate privilege, read-all, thus coupling the
setting of DAV:read and DAV:read-acl, but it is not possible to set
DAV:read, or DAV:read-
acl 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
itself. For example, DAV:read cannot contain DAV:read.
The set of privileges that apply to a particular resource may vary
with the DAV:resourcetype of the resource, as well as between
different server implementations. To promote interoperability,
however, this specification defines a set of well-known privileges
(e.g. DAV:read, DAV:write, DAV:read-acl, DAV:write-acl, DAV:read-
current-user-privilege-set,
DAV:read-current-user-privilege-set, and DAV:all), which can at least
be used to classify the other privileges defined on a particular
Clemm, Hopkins, Sedlar, Whitehead [Page 8]
resource. The 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 access control properties
specified in Section 5 are not defined on null resources). On the
transition from null to 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 implementation-defined
privilege that also controls access to GET and PROPFIND must be
aggregated under DAV:readùif DAV:read - if an ACL grants access to DAV:read, the
client may expect that no other privilege needs to be granted to have
access to GET and PROPFIND. Additionally, the read privilege MUST
control the OPTIONS method.
<!ELEMENT read EMPTY>
3.2 DAV:write Privilege
The write privilege controls methods that lock a resource or modify
the content, dead properties, or (in the case of a collection)
membership of the resource, such as PUT and PROPPATCH. Note that
state modification is also controlled via locking (see section 5.3 of [WEBDAV]),
[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 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
dead properties of the resource, such as PROPPATCH. Whether this
privilege may be used to control access to any live properties is
determined by the implementation. Any implementation-defined
privilege that also controls access to methods modifying dead
properties must be aggregated under
DAV:write-propertiesùe.g. DAV:write-properties - e.g. if an
ACL grants access to DAV:write-
properties, DAV:write-properties, the client can safely
expect that no other privilege needs to be granted to have access to
PROPPATCH.
Clemm, Hopkins, Sedlar, Whitehead [Page 9]
<!ELEMENT write-properties EMPTY>
3.4 DAV:write-content Privilege
The DAV:write-content privilege controls methods that modify the
content or (in the case of a collection) membership of the an existing resource, such as PUT and DELETE. PUT. Any
implementation-defined privilege that also controls access to content or alteration of
collection membership
must be aggregated under DAV:write-contentù DAV:write-content - e.g. if an ACL grants
access to DAV:write-content, the client can safely expect that no
other privilege needs to be granted to have access to PUT. Note that
PUT or DELETE. - when applied to an unmapped URI - creates a new resource and
therefore is controlled by the DAV:bind privilege on the parent
collection.
<!ELEMENT write-content EMPTY>
3.5 DAV:unlock Privilege
The DAV:unlock privilege controls the use of the UNLOCK method by a
principal other than the lock owner (the principal that created a
lock can always perform an UNLOCK). While the set of users who may
lock a resource 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 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 a
lock only if they have DAV:unlock privilege and they issue an UNLOCK
with the correct lock token. Lock timeout is not affected by the
DAV:unlock privilege.
<!ELEMENT unlock EMPTY>
3.6 DAV:read-acl Privilege
The DAV:read-acl privilege controls the use of PROPFIND to retrieve
the DAV:acl property of the resource.
<!ELEMENT read-acl EMPTY>
3.7 DAV:read-current-user-privilege-set Privilege
The DAV:read-current-user-privilege-set privilege controls the use of
PROPFIND to retrieve the DAV:current-user-privilege-set property of
the resource.
Clients are intended to use this property to visually indicate in
their UI items that are dependent on the permissions of a resource,
for example, by graying out resources that are not writeable.
This privilege is separate from DAV:read-acl because there is a need
to allow most users access to the privileges permitted the current
user (due to its use in creating the UI), while the full
Clemm, Hopkins, Sedlar, Whitehead [Page 10] ACL contains
information that may not be appropriate for the current authenticated
user. As a result, the set of users who can view the full ACL is
expected to 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>
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 allows a method to add a new member URL to the
specified collection (for example via PUT or MKCOL). It is ignored
for resources that are not collections.
<!ELEMENT bind EMPTY>
3.10DAV:unbind
3.10 DAV:unbind Privilege
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 are not collections.
<!ELEMENT unbind EMPTY>
3.11 DAV:all Privilege
DAV:all is an aggregate privilege that contains the entire set of
privileges that can be applied to the resource.
<!ELEMENT all EMPTY>
3.12 Aggregation of Predefined Privileges
Server implementations are free to aggregate the predefined
privileges (defined above in Sections 3.1-3.9) 3.1-3.10) subject 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: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-current-user-privilege-set.
DAV:read MUST NOT contain DAV:write, DAV:write-acl, DAV:write-
properties,
DAV:write-properties, or DAV:write-content.
Clemm, Hopkins, Sedlar, Whitehead [Page 11]
DAV:write MUST contain DAV:bind, DAV:unbind, DAV:write-properties and
DAV:write-content.
4 PRINCIPAL PROPERTIES
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 Section 13.2 of [RFC2518]), and a DAV:resourcetype
property (defined in Section 13.9 of [RFC2518]). Additionally, a
principal MUST report the DAV:principal XML element in the value of
the DAV:resourcetype property. The element type declaration for
DAV:principal is:
<!ELEMENT principal EMPTY>
This 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 may be consulted by a
client to gain additional knowledge concerning a principal. One
expected use for this property is the storage of an LDAP [RFC2255]
scheme URL. A user-agent encountering an LDAP URL could use LDAP [RFC2589]
[RFC2251] to retrieve additional machine-readable directory
information about the principal, and display that information in its
user interface. Support for this property is REQUIRED, and the value
is empty if no alternate URI exists for the principal.
<!ELEMENT alternate-URI-set (href*)>
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 the URL that MUST be used to identify
this principal in an ACL request. Support for this property is
REQUIRED.
<!ELEMENT principal-URL (href)>
4.3 DAV:group-member-set
This property of a group principal identifies the principals that are
direct members of this group. Since a group may be a member of
another group, a group may also have indirect members (i.e. the
members of its direct members). A URL in the DAV:group-member-set
for a principal MUST be the DAV:principal-URL of that principal.
<!ELEMENT group-member-set (href*)>
Clemm, Hopkins, Sedlar, Whitehead [Page 12]
4.4 DAV:group-membership
This protected property identifies the groups in which the principal
is directly a member. Note that a server may allow a group to be a
member of another group, in which case the DAV:group-membership of
those other groups would need to be queried in order to determine the
groups in which the principal is indirectly a member. Support for
this property is REQUIRED.
<!ELEMENT group-membership (href*)>
5 ACCESS CONTROL PROPERTIES
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 properties
defined in this section.
Access control properties (especially DAV:acl and DAV:inherited-
acl-set)
DAV:inherited-acl-set) are defined on the resource identified by the
Request-URI of a PROPFIND request. A direct consequence is that if
the resource is accessible via multiple URI, the value of access
control properties is the same across these URI.
HTTP resources that support the WebDAV Access Control Protocol MUST
contain the following properties. Null resources (described in
Section 3 of [RFC2518]) MUST NOT contain the following properties.
5.1 DAV:owner
This protected property identifies a particular principal as being the "owner"
of the resource. Since the owner of a resource often has special
access control capabilities (e.g., the owner frequently has permanent
DAV:write-acl privilege), clients might display the 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)> (href?)>
5.1.1 Example: Retrieving DAV:owner
This example shows a client request for the value of the DAV:owner
property from a collection resource with URL
http://www.example.com/papers/. http://www.example.com/
papers/. The principal making the request is authenticated using
Digest authentication. The value of DAV:owner is the URL http://www.example.com/acl/users/gstein, http://
www.example.com/acl/users/gstein, wrapped in the DAV:href XML
element.
>> Request <<
Clemm, Hopkins, Sedlar, Whitehead [Page 13]
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="jim@webdav.org",
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: An Attempt to Set DAV:owner
The following example shows a client request to modify the value of
the DAV:owner property on the resource with URL
<http://www.example.com/papers>. <http://
www.example.com/papers>. Since DAV:owner is a protected
property, the server property on
this 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, and Section 11 of [RFC2518] describes the Multi-
Status response.
Multi-Status response and Sections 1.6 and 3.12 of [RFC3253] describe
additional error marshalling for PROPPATCH attempts on protected
properties.
>> Request <<
PROPPATCH /papers/ HTTP/1.1
Host: www.example.com
Content-type: text/xml; charset="utf-8"
Clemm, Hopkins, Sedlar, Whitehead [Page 14]
Content-Length: xxx
Depth: 0
Authorization: Digest username="jim",
realm="jim@webdav.org",
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 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 the "group"
of 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 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 privileges defined
for the 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>
Clemm, Hopkins, Sedlar, Whitehead [Page 15]
An abstract privilege MUST NOT be used in an ACE for that resource.
Servers MUST fail an attempt to set an abstract privilege.
<!ELEMENT abstract EMPTY>
A description is a human-readable description of what this privilege
controls access to. Servers MUST indicate the 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 would
list the supported privileges in a dialog box, and allow the user to
choose non-abstract privileges to apply in an ACE. The privileges
tree is useful programmatically to map well-known privileges (defined
by WebDAV or other standards groups) into privileges that are
supported by any particular server implementation. The privilege
tree also serves to hide complexity in implementations allowing large
number of privileges to be defined by displaying aggregates to the
user.
5.2.1
5.3.1 Example: Retrieving a List of Privileges Supported on a Resource
This example shows a client request for the DAV:supported-
privilege-set
DAV:supported-privilege-set property on the resource
http://www.example.com/papers/. http://
www.example.com/papers/. The value of the DAV:supported-
privilege-set 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
normative aggregation rules given in Section 3.12), and many possible
privilege trees are possible.
>> Request <<
Clemm, Hopkins, Sedlar, Whitehead [Page 16]
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="gclemm@webdav.org",
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
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:privilege><D:all/></D:privilege>
<D:abstract/>
<D:description xml:lang="en">
Any operation</D:description> operation
</D:description>
<D:supported-privilege>
<D:privilege> <D:read/> </D:privilege>
<D:privilege><D:read/></D:privilege>
<D:description xml:lang="en">
Read any object</D:description> object
</D:description>
<D:supported-privilege>
<D:privilege> <D:read-acl/> </D:privilege>
<D:privilege><D:read-acl/></D:privilege>
<D:abstract/>
<D:description xml:lang="en">
Read
<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>
Clemm, Hopkins, Sedlar, Whitehead [Page 17]
<D:supported-privilege>
<D:privilege> <D:write/> </D:privilege>
<D:privilege><D:write/></D:privilege>
<D:description xml:lang="en">
Write any object</D:description> object
</D:description>
<D:supported-privilege>
<D:privilege> <D:write-acl/> </D:privilege>
<D:privilege><D:write-acl/></D:privilege>
<D:description xml:lang="en">
Write ACL</D:description> ACL
</D:description>
<D:abstract/>
</D:supported-privilege>
<D:supported-privilege>
<D:privilege> <D:write-properties/> </D:privilege>
<D:privilege><D:write-properties/></D:privilege>
<D:description xml:lang="en">
Write properties</D:description> properties
</D:description>
</D:supported-privilege>
<D:supported-privilege>
<D:privilege> <D:write-content/> </D:privilege>
<D:privilege><D:write-content/></D:privilege>
<D:description xml:lang="en">
Write resource content</D:description> content
</D:description>
</D:supported-privilege>
</D:supported-privilege>
<D:supported-privilege>
<D:privilege> <D:unlock/> </D:privilege>
<D:privilege><D:unlock/></D:privilege>
<D:description xml:lang="en">
Unlock resource</D:description> 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>
5.3
5.4 DAV:current-user-privilege-set
DAV:current-user-privilege-set is a protected property containing the
exact set of privileges (as computed by the server) granted to the
currently authenticated HTTP user. Aggregate privileges and their
contained privileges are listed. A user-agent can use the value of
this property to adjust its user interface to make actions
inaccessible (e.g., by graying out a menu item or button) for which
the current principal does not have permission. This property is also
useful for determining what operations the current principal can
perform, without having to actually execute an operation.
<!ELEMENT current-user-privilege-set (privilege*)>
<!ELEMENT privilege ANY>
If the current user is granted a specific privilege, that privilege
must belong to the set of privileges that may be set on this
resource. Therefore, each element in the DAV:current-user-
Clemm, Hopkins, Sedlar, Whitehead [Page 18]
privilege-set
DAV:current-user-privilege-set property MUST identify a non-abstract
privilege from the DAV:supported-privilege-set property.
5.3.1
5.4.1 Example: Retrieving the User's Current Set of Assigned Privileges
Continuing the example from Section 5.2.1, 5.3.1, this example shows a
client requesting the DAV:current-user-privilege-set property from
the resource with URL http://www.example.com/papers/. The username of
the principal making the request is "khare", and Digest
authentication is used 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 and DAV:read-current-
user-privilege-set
DAV:read-current-user-privilege-set privileges (see Section 5.2.1), 5.3.1),
the principal with username "khare" can read the ACL property, and
the DAV:current-user-privilege-set property. However, the DAV:all,
DAV:read-acl, DAV:write-acl and DAV:read-current-user-privilege-
set DAV:read-current-user-privilege-set
privileges are not listed in the value of DAV:current-user-
privilege-set,
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 /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="khare@webdav.org",
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>
>> 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>
Clemm, Hopkins, Sedlar, Whitehead [Page 19]
<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>
5.4
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?)>
5.4.1
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.
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 identified property
of that resource contains at most one DAV:href XML
Clemm, Hopkins, Sedlar, Whitehead [Page 20] element, the URI
value of DAV:href identifies a principal, and the current user is
authenticated as being (or being a member of) that 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 current user matches DAV:self in a DAV:acl property of the
resource only if that resource is a principal and that principal
matches the current user or, if the principal is a group, a member of
that group matches the current user.
<!ELEMENT self EMPTY>
Some servers may 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>
5.4.2
5.5.2 ACE Grant and Deny
Each DAV:grant or DAV:deny element specifies the set of privileges to
be either granted or denied to the specified principal. A DAV:grant
or DAV:deny element of the DAV:acl of a resource MUST only contain
non-abstract elements specified in the DAV:supported-
privilege-set DAV:supported-privilege-set of
that resource.
<!ELEMENT grant (privilege+)>
<!ELEMENT deny (privilege+)>
<!ELEMENT privilege ANY>
5.4.3
5.5.3 ACE Protection
A server indicates an ACE is protected by including the DAV:protected
element in the ACE. If the ACL of a resource contains an ACE with a
DAV:protected element, an attempt to remove that ACE from the ACL
MUST fail.
<!ELEMENT protected EMPTY>
5.4.4
5.5.4 ACE Inheritance
The presence of a DAV:inherited element indicates that this ACE is
inherited from another resource that is identified by the URL
contained in a DAV:href 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
Clemm, Hopkins, Sedlar, Whitehead [Page 21] 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)>
5.4.5
5.5.5 Example: Retrieving a Resource's Access Control List
Continuing the example from Sections 5.2.1 5.3.1 and 5.3.1, 5.4.1, this example
shows a client requesting the DAV:acl property from the resource with
URL http://www.example.com/papers/. There are two ACEs defined in
this ACL:
ACE #1: The group identified by URL
http://www.example.com/acl/groups/maintainers 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 5.2.1), 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 and
DAV:read-current-user-privilege-set, this means all users (including
all members of the "maintainers" group) can read the DAV:acl property
and the 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="webdav.org",
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>
Clemm, Hopkins, Sedlar, Whitehead [Page 22]
<D:propstat>
<D:prop>
<D:acl>
<D:ace>
<D:principal>
<D:href>http://www.example.com/acl/groups/maintainers</D:href>
<D:href
>http://www.example.com/acl/groups/maintainers</D:href>
</D:principal>
<D:grant>
<D:privilege> <D:write/> </D:privilege>
<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: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>
5.5 DAV: acl-restrictions
5.6 DAV:acl-restrictions
This protected property defines the types of ACLs supported by this
server, to avoid clients needlessly getting errors. When a client
tries to set an ACL via the ACL method, the server may reject the
attempt to set the ACL as specified. The following properties
indicate the restrictions the 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 principals are required to be
present
<!ELEMENT acl-restrictions (grant-only?, no-invert?, deny-before-
grant?,
deny-before-grant?,
required-principal?)>
5.5.1
5.6.1 DAV:grant-only
This element indicates that ACEs with deny clauses are not allowed.
Clemm, Hopkins, Sedlar, Whitehead [Page 23]
<!ELEMENT grant-only EMPTY>
5.5.2
5.6.2 DAV:no-invert ACE Constraint
This element indicates that ACEs with the <invert> element are not
allowed.
<!ELEMENT no-invert EMPTY>
5.5.3
5.6.3 DAV:deny-before-grant
This element indicates that all deny ACEs must precede all grant
ACEs.
<!ELEMENT deny-before-grant EMPTY>
5.5.4
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 the ACL contain a
DAV:owner property ACE:
<D:required-principal xmlns:D="DAV:">
<D:property> <D:owner/> </D:property>
<D:property><D:owner/></D:property>
</D:required-principal>
5.6.5 Example: Retrieving DAV:acl-restrictions
In this example, the client requests the value of the DAV:acl-
restrictions
DAV:acl-restrictions property. Digest authentication provides
credentials for the principal operating the client.
>> 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",
realm="srcarter@webdav.org",
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:prop>
Clemm, Hopkins, Sedlar, Whitehead [Page 24]
</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:response>
</D:multistatus>
5.6
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 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*)>
5.7
5.8 DAV:principal-collection-set
This protected property of a 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. A WebDAV
Access Control Protocol user agent could use the contents of
DAV:principal-collection-set to retrieve the DAV:displayname property
(specified in Section 13.2 of [RFC2518]) of 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*)>
Clemm, Hopkins, Sedlar, Whitehead [Page 25]
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 the DAV:principal-property-search REPORT to populate
their user interface with a list of principals. Therefore, servers
that limit a client's ability to obtain principal information will
interfere with the client's ability to manipulate access control
lists, due to the difficulty of getting the URL of a principal for
use in an ACE.
5.7.1
5.8.1 Example: Retrieving DAV:principal-collection-set
In this example, the client requests the value of the
DAV:principal-collection-set property on the collection resource
identified by 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/, http://
www.example.com/acl/groups/, both wrapped in DAV:href XML elements.
Digest authentication provides credentials for the principal
operating 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 and /acl/groups). This
information could be used when displaying a 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="yarong@webdav.org",
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>
Clemm, Hopkins, Sedlar, Whitehead [Page 26]
>> 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>
5.8
5.9 Example: PROPFIND to retrieve access control properties
The following example shows how access control information can be
retrieved by using the PROPFIND method to fetch the values of the
DAV:owner, DAV:supported-privilege-set, DAV:current-user-
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@foo.org",
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
Clemm, Hopkins, Sedlar, Whitehead [Page 27]
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:privilege><D:all/></D:privilege>
<D:abstract/>
<D:description xml:lang="en">Any operation</D:description> xml:lang="en">
Any operation
</D:description>
<D:supported-privilege>
<D:privilege> <D:read/> </D:privilege>
<D:privilege><D:read/></D:privilege>
<D:description xml:lang="en">Read xml:lang="en">
Read any
object</D:description> object
</D:description>
</D:supported-privilege>
<D:supported-privilege>
<D:privilege> <D:write/> </D:privilege>
<D:privilege><D:write/></D:privilege>
<D:abstract/>
<D:description xml:lang="en">Write xml:lang="en">
Write any
object</D:description> object
</D:description>
<D:supported-privilege>
<D:privilege> <A:create/> </D:privilege>
<D:privilege><A:create/></D:privilege>
<D:description xml:lang="en">Create xml:lang="en">
Create an
object</D:description> object
</D:description>
</D:supported-privilege>
<D:supported-privilege>
<D:privilege> <A:update/> </D:privilege>
<D:privilege><A:update/></D:privilege>
<D:description xml:lang="en">Update xml:lang="en">
Update an
object</D:description> object
</D:description>
</D:supported-privilege>
</D:supported-privilege>
<D:supported-privilege>
<D:privilege> <A:unbind/> </D:privilege>
<D:privilege><A:delete/></D:privilege>
<D:description xml:lang="en">Remove binding to xml:lang="en">
Delete an
object</D:description>
</D:supported-privilege> object
</D:description>
</D:supported-privilege>
<D:supported-privilege>
<D:privilege> <D:read-acl/> </D:privilege>
<D:privilege><D:read-acl/></D:privilege>
<D:description xml:lang="en">Read xml:lang="en">
Read the
ACL</D:description> ACL
</D:description>
</D:supported-privilege>
<D:supported-privilege>
<D:privilege> <D:write-acl/> </D:privilege>
<D:privilege><D:write-acl/></D:privilege>
<D:description xml:lang="en">Write xml:lang="en">
Write the
ACL</D:description> ACL
</D:description>
</D:supported-privilege>
Clemm, Hopkins, Sedlar, Whitehead [Page 28]
</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: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: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:privilege><D:read/></D:privilege>
</D:deny>
</D:ace>
<D:ace>
<D:principal>
<D:property> <D:owner/> </D:property>
<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: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:principal><D:all/></D:principal>
<D:grant>
<D:privilege> <D:read/> </D:privilege></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>
The value of the DAV:owner property is a single DAV:href XML element
containing the URL of the principal that owns this resource.
The value of the DAV:supported-privilege-set property is a tree of
supported privileges (using "[XML Namespace , localname]" to identify
each privilege):
Clemm, Hopkins, Sedlar, Whitehead [Page 29]
[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 DAV:read-acl. This indicates that the current
authenticated user only has the ability to read the resource, and
read the DAV:acl property on the resource. The DAV:acl property
contains a set of four ACEs:
ACE #1: The principal identified by the URL
http://www.example.com/users/esedlar http://www.example.com/
users/esedlar is granted the DAV:read, DAV:write, and DAV:read-acl
privileges.
ACE #2: The principals identified by the URL
http://www.example.com/groups/marketing http://www.example.com/
groups/marketing are denied the DAV:read privilege. In this example,
the principal URL identifies a group.
ACE #3: In this ACE, the principal is a property principal,
specifically the DAV:owner property. When evaluating this ACE, the
value of the DAV:owner property is retrieved, and is examined to see
if it contains a 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 ACE grants the DAV:all principal (all users) the
DAV:read privilege. This ACE is inherited from the resource
http://www.example.com/top, http://
www.example.com/top, the parent collection of this resource.
6
6. ACL EVALUATION Evaluation
WebDAV ACLs are evaluated in similar manner as ACLs on Windows NT and
in NFSv4 [NFSV4]). [RFC3530]). An ACL is evaluated to determine whether or not
access will be granted for a WebDAV request. ACEs are maintained in
a particular order, and are evaluated until all of the permissions
required by the current request have been granted, at which point the
ACL evaluation is terminated and access is granted. If, during ACL
evaluation, a <deny> ACE (matching the current user) is encountered
for a privilege which has not yet been granted, the ACL evaluation is
terminated and access is denied. Failure to have all required
privileges granted results in access being denied.
Note that the semantics of many other existing ACL systems may be
represented via this mechanism, by mixing deny and grant ACEs. For
example, consider the standard "rwx" privilege scheme used by UNIX.
In this scheme, if the current user is the owner of the file, access
is granted if the corresponding privilege bit is set and denied if
not set, regardless of the permissions set on the
Clemm, Hopkins, Sedlar, Whitehead [Page 30]
fileÆs file's group and
for the world. An ACL for UNIX permissions of
"r--rw-r--"might "r--rw-r--" might be
constructed like:
<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: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: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:principal>
<D:grant><D:privilege><D:read/></D:privilege>
<D:privilege><D:write/></D:privilege></D:grant>
<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:ace>
<D:principal><D:property>
<D:group/> </D:property></D:principal>
<D:deny><D:privilege><D:all/></D:privilege></D:deny>
<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>
<D:grant>
<D:privilege><D:read/></D:privilege>
</D:grant>
</D:ace>
</D:acl>
and the <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 client can still get errors from a UNIX server in spite
of obeying the <acl-restrictions>, including <D:allowed-
principal> <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
7. Access Control and existing methods
This section defines the impact of access control functionality on
existing methods.
Clemm, Hopkins, Sedlar, Whitehead [Page 31]
7.1 ANY Any HTTP METHOD 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 additional precondition called
DAV:need-privileges. If an HTTP method fails due to insufficient
privileges, the response body to the "403 Forbidden" error MUST
contain the <DAV:error> element, which in turn contains the
<DAV:need-privileges> element, which contains one or more
<DAV:resource> elements indicating which resource had insufficient
privileges, and 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 resolve any ambiguity. There
is no requirement that all privilege violations be reportedù reported - for
implementation reasons, some servers may only report the first
privilege violation. For example:
>> 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 the server supports access control, it MUST return "access-
control"
"access-control" as a field in 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 the server
Clemm, Hopkins, Sedlar, Whitehead [Page 32]
supports all MUST level requirements and REQUIRED features specified
in this document.
7.2.1 Example - OPTIONS
>> Request <<
OPTIONS /foo.html HTTP/1.1
Host: www.example.com
Content-Length: 0
>> Response <<
HTTP/1.1 200 OK
DAV: 1, 2, access-control
Allow: OPTIONS, GET, PUT, PROPFIND, PROPPATCH, ACL
In this example, the OPTIONS response indicates that the 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 a MOVE
request, the non-inherited and non-protected ACEs in the DAV:acl
property of the resource MUST NOT be modified, or the MOVE request
fails. Handling 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 resource at the destination of a COPY
MUST be the 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 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 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.
8 ACCESS CONTROL METHODS
8. Access Control Methods
8.1 ACL
The ACL method modifies the access control list (which can be read
via the DAV:acl property) of a resource. Specifically, the ACL
Clemm, Hopkins, Sedlar, Whitehead [Page 33] 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
non-inherited and non-protected ACEs in a resource's access control
list to exactly match the ACEs contained within in the DAV:acl XML
element (specified in Section 5.4) 5.5) of the request body. An ACL
request body MUST contain only one DAV:acl XML element. Unless the
non-inherited and non-protected ACEs of the DAV:acl property of the
resource can be updated to be exactly the value specified in the ACL
request, the ACL request MUST fail.
It is possible that the ACEs visible to the current user in the
DAV:acl property may only be a portion of the complete set of ACEs on
that resource. If this is the case, an ACL request 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 another client, a
client SHOULD acquire a WebDAV lock on the resource before retrieving
the DAV:acl property of a resource 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 PROPFIND method to retrieve the value of the
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 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 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 DTD), implementations MAY
return additional descriptive XML elements as children of the status
element. Clients MUST be able to accept children of these status
elements. Clients that do not understand the additional XML elements
should ignore them.
(DAV:no-ace-conflict): The ACEs submitted in 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): The ACEs submitted in the ACL
request MUST NOT conflict with the protected ACEs on the resource.
For example, if the resource has a protected ACE granting DAV:write
to a given principal, then it would not be consistent if
Clemm, Hopkins, Sedlar, Whitehead [Page 34] the ACL
request submitted an ACE denying DAV:write to the same principal.
(DAV:no-inherited-ace-conflict): The ACEs submitted in the ACL
request MUST NOT conflict with the inherited ACEs on the resource.
For example, if the resource inherits an ACE from its parent
collection granting DAV:write to a given principal, then it would not
be consistent if the ACL request submitted an ACE denying DAV:write
to the same principal. Note that reporting of this 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 specific principal.
(DAV:limited-number-of-aces): The number of ACEs submitted in the ACL
request MUST NOT exceed the number of ACEs allowed on that resource.
However, ACL-compliant servers MUST support at least one ACE granting
privileges to a 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 precondition applies only when the ACL
restrictions of the resource include the DAV:grant-only constraint
(defined in Section 5.5.1). 5.6.1).
(DAV:no-invert): The ACL request MUST NOT include a DAV:invert
element. This precondition applies only when the ACL semantics of
the resource includes the DAV:no-invert constraint (defined in
Section 6.3.4). 5.6.2).
(DAV:no-abstract): The ACL request MUST NOT attempt to grant or deny
an abstract privilege (see Section 5.2). 5.3).
(DAV:not-supported-privilege): The ACEs submitted in the ACL request
MUST be supported by the resource.
(DAV:missing-required-principal): The result of the ACL request MUST
have at least one ACE for each principal identified in a
DAV:required-principal XML element in the ACL semantics of that
resource (see Section 5.5.4). 5.5).
(DAV:recognized-principal): Every principal URL in the ACL request
MUST identify a principal resource.
(DAV:allowed-principal): The principals specified in the ACEs
submitted in the ACL request MUST be allowed as principals for the
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: the the ACL method
In the following example, user "fielding", authenticated by
information in the Authorization header, grants the principal
identified by the URL http://www.example.com/users/esedlar (i.e.,
the user "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 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>
<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 <<
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:">
<D:ace>
<D:principal>
<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/1.1 403 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 example, request, user "fielding", "ejw", authenticated by information in
the Authorization header, tries to change the access control list on
the resource http://www.example.com/top/index.html. This resource has
two inherited ACEs.
Inherited ACE #1 grants the principal identified by the URL http://www.example.com/users/esedlar http://
www.example.com/users/ejw (i.e.,
Clemm, Hopkins, Sedlar, Whitehead [Page 35] the user "esedlar") read "ejw") http://
www.example.com/privs/write-all and write privileges, DAV:read-acl privileges. On this
server, http://www.example.com/privs/write-all is an aggregate
privilege containing DAV:write, and DAV:write-acl.
Inherited ACE #2 grants principal DAV:all the owner of DAV:read privilege.
The request attempts to set a (non-inherited) ACE, denying the resource read-acl and write-acl privileges,
principal identified by the URL http://www.example.com/users/ejw
(i.e., the user "ejw") DAV:write permission. This conflicts with
inherited ACE #1. Note that the decision to report an inherited ACE
conflict is specific to this server implementation. Another server
implementation could have allowed the new ACE to be set, and grants
everyone read privileges. then
used normal ACE evaluation rules to determine whether the new ACE has
any impact on the privileges available to a principal.
>> Request <<
ACL /top/container/ /top/index.html HTTP/1.1
Host: www.example.com
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
Authorization: Digest username="fielding",
realm="users@foo.org", username="ejw",
realm="users@example.com", nonce="...",
uri="/top/container/",
uri="/top/index.html", 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>
<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> xmlns:D="DAV:" xmlns:F="http://www.example.com/privs/">
<D:ace>
<D:principal> <D:all/>
<D:href>http://www.example.com/users/ejw</D:href>
</D:principal>
<D:grant>
<D:privilege> <D:read/> </D:privilege>
</D:grant>
<D:grant><D:write/></D:grant>
</D:ace>
</D:acl>
>> Response <<
HTTP/1.1 200 OK
8.1.3 403 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 protected ACE conflict
In an attempt to set grant and
deny in a single ACE
In this example, user "ygoland", authenticated by information in the
Authorization header, tries to change the access control list on the
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 following request, user "fielding", authenticated group identified by
information in the Authorization header, attempts to URL http://
www.example.com/users/friends DAV:read privilege and deny the
principal identified by the URL
http://www.example.com/users/esedlar http://www.example.com/users/ygoland-so
(i.e., the user "esedlar")
write privileges. Prior "ygoland-so") DAV:read privilege. However, it is
illegal to the request, the DAV:acl property on
the resource contained have multiple principal elements, as well as both a protected ACE (see Section 5.4.3)
granting DAV:owner the DAV:read grant
and DAV:write privileges. The
Clemm, Hopkins, Sedlar, Whitehead [Page 36]
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 deny element in the protected same ACE, thus
violating so the semantics of ACE protection. request fails due to poor
syntax.
>> Request <<
ACL /top/container/ /diamond/engagement-ring.gif HTTP/1.1
Host: www.example.com
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
Authorization: Digest username="fielding",
realm="users@foo.org", username="ygoland",
realm="users@example.com", nonce="...",
uri="/top/container/",
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/esedlar</D:href>
<D:href>http://www.example.com/users/friends</D:href>
</D:principal>
<D:deny>
<D:privilege> <D:write/> </D:privilege>
</D:deny>
<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/1.1 403 Forbidden
Content-Type: text/xml; charset="utf-8" 400 Bad Request
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 0
Note that if the request had been divided into two ACEs, one to
grant, and one to deny, the request would have been syntactically
well formed.
9. Access Control Reports
9.1 REPORT Method
The REPORT method failure due (defined in Section 3.6 of [RFC3253]) provides an
extensible mechanism for obtaining information about a resource.
Unlike the PROPFIND method, which returns the value of one or more
named properties, the REPORT method can involve more complex
processing. REPORT is valuable in cases where the server has access
to all of the information needed to perform the complex request (such
as a query), and where it would require multiple requests for the
client to an inherited ACE conflict
In retrieve the following request, user "ejw", authenticated by information
in the Authorization header, tries needed to change perform the access control
list on same
request.
A server that supports the resource http://www.example.com/top/index.html. This
resource has two inherited ACEs.
Inherited ACE #1 grants WebDAV Access Control Protocol MUST
support the principal DAV:expand-property report (defined in Section 3.8 of
[RFC3253]).
9.2 DAV:acl-principal-prop-set Report
The DAV:acl-principal-prop-set report returns, for all principals in
the DAV:acl property (of the Request-URI) that are identified by URL
http://www.example.com/users/ejw (i.e.,
http(s) URLs or by a DAV:property principal, 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 an aggregate privilege containing DAV:write, and DAV:write-acl.
Inherited ACE #2 grants principal DAV:all value of the DAV:read privilege.
The
properties specified in the REPORT request attempts to set body. In the case where a (non-inherited) ACE, denying
principal URL appears multiple times, the DAV:acl-principal-prop-set
report MUST return the properties for that principal identified by only once.
Support for this report is REQUIRED.
One expected use of this report is to retrieve the URL http://www.example.com/users/ejw
(i.e., human readable
name (found in the user "ejw") DAV:write permission. DAV:displayname property) of each principal found
in an ACL. This conflicts with
Clemm, Hopkins, Sedlar, Whitehead [Page 37]
inherited is useful for constructing user interfaces that show
each ACE #1. in a 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 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 decision to report an inherited
ACE conflict Depth header is specific to this server implementation. Another
server implementation could have allowed the new ACE
not present, it defaults to a value of "0".
The response body for a successful request MUST be set,
and then used normal ACE evaluation rules to determine whether a
DAV:multistatus XML element (i.e., the
new ACE has any impact on response uses the privileges available to a principal.
>> 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@foo.org", 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 xmlns:D="DAV:"/>
</D:error>
8.1.5 Example: ACL method failure due to an attempt to set grant and
deny in a single ACE.
In this example, user "ygoland", authenticated by information in same
format as the Authorization header, tries to change response for PROPFIND). In the access control list
on case where there are
no response elements, the resource http://www.example.com/diamond/engagement-
ring.gif. returned multistatus XML element is
empty.
multistatus: see RFC 2518, Section 12.9
The ACL response body for a successful DAV:acl-principal-prop-set
REPORT request includes MUST contain a single, syntactically and
semantically incorrect ACE, which attempts to grant DAV:response element for each
principal identified by an http(s) URL listed in a DAV:principal
XML element of an ACE within the group DAV:acl property of the resource
identified by the URL http://www.example.com/users/friends Request-URI.
Postconditions:
(DAV:number-of-matches-within-limits): The number 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 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 privilege and deny the
DAV:read-current-user-privilege-set access.
ACE #2: The principal identified by URL
http://www.example.com/users/ygoland-so (i.e., the http://www.example.com/people/
gstein (the user "ygoland-
so") DAV:read privilege. However, it "gstein") is illegal to have multiple
principal elements, as well as both a grant 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) is granted DAV:write and deny element in DAV:read-acl
privileges.
The following example shows a DAV:acl-principal-prop-set report
requesting the same ACE, so DAV:displayname property. It returns the request fails due to poor syntax. value 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 <<
ACL /diamond/engagement-ring.gif
REPORT /index.html HTTP/1.1
Clemm, Hopkins, Sedlar, Whitehead [Page 38]
Host: www.example.com
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
Authorization: Digest username="ygoland",
realm="users@foo.org", nonce="...",
uri="/diamond/engagement-ring.gif", response="...",
opaque="..."
Depth: 0
<?xml version="1.0" encoding="utf-8" ?>
<D:acl
<D:acl-principal-prop-set 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>
<D:prop>
<D:displayname/>
</D:prop>
</D:acl-principal-prop-set>
>> Response <<
HTTP/1.1 400 Bad Request 207 Multi-Status
Content-Type: text/xml; charset="utf-8"
Content-Length: 0
Note that if the request had been divided into two ACEs, one to
grant, and one 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 the PROPFIND method, which returns the value of
one or more named properties, the 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 method can involve more
complex processing.
The DAV:principal-match REPORT is valuable in cases where the server
has access used to identify all members (at
any depth) of the information needed to perform collection identified by the complex
request (such as a query), Request-URI that are
principals and where it would require multiple
requests for that match the client to retrieve current user. In particular, if the information needed
collection contains principals, the report can be used to
perform identify
all members of the same request.
A server collection that supports the WebDAV Access Control Protocol MUST
support match the DAV:expand-property report (defined in Section 3.8 of
[RFC3253]).
9.2 DAV:acl-principal-prop-set Report
The DAV:acl-principal-prop-set report returns, for all principals
in current user.
Alternatively, if the DAV:acl collection contains resources that have a
property (of the Request-URI) that are identified
by http(s) URLs or by identifies a DAV:property principal, principal (e.g. DAV:owner), the value report can
be used to identify all members of the
Clemm, Hopkins, Sedlar, Whitehead [Page 39]
properties specified in the REPORT request body. In the case where collection whose property
identifies a principal URL appears multiple times, that matches the DAV:acl-principal-
prop-set current user. For example,
this report MUST can return all of the properties for resources in a collection hierarchy
that principal only
once. are owned by the current user. Support for this report is
REQUIRED.
One expected use of this report is 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
that show each ACE in a human readable form.
Marshalling
Marshalling:
The request body MUST be a DAV:acl-principal-prop-set DAV:principal-match XML element.
<!ELEMENT acl-principal-prop-set principal-match ((principal-property | self), prop?)>
<!ELEMENT principal-property ANY>
ANY value: an element whose value identifies a sequence property. The
expectation is the value of one or more elements, with at most one
DAV:prop element. 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:multistatus XML element (i.e., the response uses the same
format as the response for PROPFIND). element. In the
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 successful DAV:acl-principal-prop-set DAV:principal-match REPORT
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 the principal identified by an http(s) URL listed the URI
found in a DAV:principal
XML the DAV:href element of an ACE within the DAV:acl property of the resource identified by the Request-URI.
Postconditions:
(DAV:number-of-matches-within-limits): The number of matching
principals must fall within server-specific, predefined limits.
For example, this condition might be triggered
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 search
specification would cause member identifies the 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 same principal identified by
http://www.example.com/people/gstein (the user "gstein") is
granted DAV:write, DAV:write-acl, DAV:read-acl privileges.
Clemm, Hopkins, Sedlar, Whitehead [Page 40]
ACE #3: The group identified by
http://www.example.com/groups/authors (the "authors" group) as the current
user.
If DAV:prop is
granted DAV:write and DAV:read-acl privileges.
The following example shows a DAV:acl-principal-prop-set report
requesting specified in the DAV:displayname property. It returns request body, the properties
specified in the DAV:prop element MUST be reported in the
DAV:response elements.
9.3.1 Example: DAV:principal-match REPORT
The following example identifies the value members 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 the collection
identified by the URL http://www.example.com/doc that are owned by
the current user. The current user ("gclemm") is not an http(s) URL. authenticated using
Digest authentication.
>> Request <<
REPORT /index.html /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: xxxx
Depth: 0
<?xml version="1.0" encoding="utf-8" ?>
<D:acl-principal-prop-set
<D:principal-match xmlns:D="DAV:">
<D:prop>
<D:displayname/>
</D:prop>
</D:acl-principal-prop-set>
<D:principal-property>
<D:owner/>
</D:principal-property>
</D:principal-match>
>> 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:href>http://www.example.com/doc/foo.html</D:href>
<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:href>http://www.example.com/doc/img/bar.gif</D:href>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>
Clemm, Hopkins, Sedlar, Whitehead [Page 41]
9.3 DAV:principal-match
9.4 DAV:principal-property-search REPORT
The DAV:principal-match DAV:principal-property-search REPORT is used to identify performs a search for all members (at
any depth) of the collection identified by the Request-URI that
are
principals and whose properties contain character data that match the current user. In particular, if matches the collection contains principals,
search criteria specified in the request. One expected use of this
report can be used is to
identify all members of the collection that match the current
user. Alternatively, if discover the collection contains resources that
have a property that identifies URL of a principal (e.g. DAV:owner), associated with a given
person or group by searching for them by name. This is done 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 is left to the
report can be used server
implementation to identify all members allow implementation on a wide set of possible user
management systems. In cases where the collection whose
property identifies a principal that matches implementation of
DAV:principal-property-search is not constrained by the current user. semantics of
an underlying user management repository, preferred default semantics
are caseless substring matches.
For
example, this report can return implementation efficiency, servers do not typically support
searching on all of the resources in a
collection hierarchy properties. A search requesting properties that are owned by the current user.
not searchable for a particular principal will not match that
principal.
Support for this the DAV:principal-property-search report is REQUIRED.
Marshalling:
Implementation Note: The request body MUST be a DAV:principal-match XML element.
<!ELEMENT principal-match ((principal-property | self), prop?)>
<!ELEMENT principal-property ANY>
ANY value: an element whose value identifies of a property. The
expectation WebDAV property is the value a sequence
of well-formed XML, and hence can include any character in the named property typically contains
an href element
Unicode/ISO-10646 standard, 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 is, most known characters in a 400 (Bad Request) error response. Note
that [RFC3253], Section 3.6, states that if the Depth header is
not present, it defaults
human languages. Due to a value of "0".
The response body for a successful request MUST be a
DAV:multistatus XML element. In the idiosyncrasies of case where there are no
response elements, the returned multistatus XML element mapping across
human languages, implementation of case-insensitive matching is empty.
multistatus: see RFC 2518,
non-trivial. Implementors of servers that do perform substring
matching are strongly encouraged to consult "The Unicode Standard"
[UNICODE4], especially Section 12.9
The response body 5.18, Subsection "Caseless
Matching", for a successful DAV:principal-match REPORT
request MUST contain a DAV:response element guidance when implementing their case-insensitive
matching algorithms.
Implementation Note: Some implementations of this protocol will
use an LDAP repository for each member storage 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 the principal identified by the URI found metadata. The
schema describing each attribute (akin to a WebDAV property) in the
DAV:href element an
LDAP repository specifies whether it supports case-sensitive or
caseless searching. One of the property 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 benefits of leaving the
group if a member identifies search
method to the same principal as discretion of the current
user.
If DAV:prop server implementation is specified in the request body, the properties
specified in the DAV:prop element MUST
default LDAP attribute search behavior can be reported in the
DAV:response elements.
Clemm, Hopkins, Sedlar, Whitehead [Page 42]
9.3.1 Example: DAV:principal-match REPORT
The following example identifies the members of the collection
identified by the URL http://www.example.com/doc that are owned by used when
implementing the current user. The current user ("gclemm") is authenticated
using Digest authentication.
>> Request <<
REPORT /doc/ HTTP/1.1
Host: www.example.com
Authorization: Digest username="gclemm",
realm="gclemm@webdav.org", nonce="...",
uri="/papers/", response="...", opaque="..."
Content-Type: text/xml; charset="utf-8"
Content-Length: xxxx
Depth: 0
<?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/1.1 207 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/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 report.
Marshalling:
The DAV:principal-property-search REPORT performs request body MUST be a search for all
principals whose properties contain character data DAV:principal-property-search XML
element containing a search specification and an optional list of
properties. For every principal that matches the search criteria specified in
specification, the request. One expected use response will contain the value of
this report is to discover the URL
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 a principal associated with
a given person or group by searching for them by name. This is
done the
collection identified by searching over DAV:displayname, which the Request-URI. If
DAV:apply-to-principal-collection-set is defined on all
principals.
The actual search method (exact matching vs. substring matching
vs, prefix-matching, case-sensitivity) deliberately specified in the request
body, the request is left applied instead to each collection identified
by the
Clemm, Hopkins, Sedlar, Whitehead [Page 43]
server implementation to allow implementation on a wide set DAV:prinicipal-collection-set property of
possible user management systems. In cases where the
implementation of DAV:principal-property-search is not constrained resource
identified by the 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 Request-URI.
The DAV:property-search element contains a prop element
enumerating the properties that
are not searchable for to be searched and a particular principal will not match element,
containing the search string.
<!ELEMENT property-search (prop, match) >
prop: see RFC 2518, Section 12.11
<!ELEMENT match #PCDATA >
Multiple property-search elements or multiple elements within a
DAV:prop element will be interpreted with a logical AND.
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
principal.
Support for if the DAV:principal-property-search report Depth header is REQUIRED.
Implementation Note: The
not present, it defaults to a value of "0".
The response body for a WebDAV property is successful request MUST be a
sequence of well-formed XML, and hence can include any
character in the Unicode/ISO-10646 standard, that is, most
known characters in human languages. Due to
DAV:multistatus XML element. In the idiosyncrasies
of case mapping across human languages, implementation of case-
insensitive matching is non-trivial. Implementors of servers
that do perform substring matching where there are strongly encouraged to
consult [CaseMap], especially no
response elements, the returned multistatus XML element is empty.
multistatus: see RFC 2518, Section 2.3 ("Caseless
Matching"), 12.9
The response body for guidance when implementing their case-
insensitive matching algorithms.
Implementation Note: Some implementations of this protocol will
use an LDAP repository a successful DAV:principal-property-search
REPORT request MUST contain a DAV:response element for storage of principal metadata. The
schema describing each attribute (akin to a WebDAV property)
principal whose property values satisfy the search specification
given in DAV:principal-property-search.
The response body for an LDAP repository specifies whether it supports case-sensitive unsuccessful
DAV:principal-property-search REPORT request MUST contain, after
the XML element indicating the failed precondition or caseless searching. One
postcondition, a DAV:prop element containing the property that
caused the pre/postcondition to fail.
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 matching
principals must fall within server-specific, predefined limits.
For example, this condition might be triggered if a search
specification would cause the benefits return of an extremely large number
of leaving responses.
9.4.1 Matching
There are several cases to consider when matching strings. The
easiest case is when a property value is "simple" and has only
character information item content (see [REC-XML-INFOSET]). For
example, the search method to string "julian" would match the discretion DAV:displayname
property with value "Julian Reschke". Note that the on-the-wire
marshalling of DAV:displayname in this case is:
<D:displayname xmlns:D="DAV:">Julian Reschke</D:displayname>
The name of the server implementation property is encoded into the default LDAP attribute search behavior can be used when
implementing the DAV:principal-property-search report.
Marshalling:
The request body MUST be a DAV:principal-property-search XML element containing a search specification information
item, and an optional list of
properties. For every principal that matches the search
specification, the response will contain the value character information item content of the
requested property is
"Julian Reschke".
A more complicated case occurs when 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) have mixed content
(that is, compound values consisting of multiple child element items,
other types of information items, and character information item
content). Consider the
collection identified by property "aprop" in the Request-URI. If DAV:apply-to-
principal-collection-set 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 specified in performed on each individual contiguous
sequence of character information items. In the request body, example above, a
search string would be compared to the 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 this example, the
request is applied instead to each collection identified by client requests the
DAV:prinicipal-collection-set property principal URLs of all users
whose DAV:displayname property contains the resource identified
by substring "doE" and whose
"title" property in the Request-URI.
The DAV:property-search element namespace "http://BigCorp.com/ns/" (that is,
their professional title) contains a prop element
enumerating "Sales". In addition, the client
requests five properties to be searched and a match element,
containing returned with the matching principals:
In the DAV: namespace: displayname
In the http://www.example.com/ns/ namespace: department, phone,
office, salary
The response shows that two principal resources meet the search string.
<!ELEMENT property-search (prop, match) >
prop: see RFC 2518, Section 12.11
Clemm, Hopkins, Sedlar, Whitehead [Page 44]
<!ELEMENT match #PCDATA >
Multiple property-search elements or multiple elements within a
DAV:prop element will
specification, "John Doe" and "Zygdoebert Smith". The property
"salary" in namespace "http://www.example.com/ns/" is not returned,
since the principal making the request does not have sufficient
access permissions to read this 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>
<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 may be interpreted with a logical AND.
This report is only defined when searched using the Depth header has value "0";
other values result
DAV:principal-property-search REPORT (defined in a 400 (Bad Request) error response. Note
that [RFC3253], Section 3.6, states that if 9.4).
Servers MUST support the DAV:principal-search-property-set REPORT on
all collections identified in the Depth header is
not present, it defaults to a value of "0".
The response body for a successful request MUST be a
DAV:multistatus XML element. In
DAV:principal-collection-set property.
An access control protocol user agent could use the case where there are no
response elements, results of the returned multistatus XML element is empty.
multistatus: see RFC 2518, Section 12.9
The response body for a successful DAV:principal-property-search
DAV:principal-search-property-set REPORT request MUST contain to present a DAV:response element for each
principal whose property values satisfy query interface
to the search specification
given in DAV:principal-property-search.
The response body user for retrieving principals.
Support for this report is REQUIRED.
Implementation Note: Some clients will have only limited screen
real estate for an unsuccessful DAV:principal-property-
search REPORT request MUST contain, after the XML element
indicating the failed precondition or postcondition, display of lists of searchable properties. In
this case, a DAV:prop
element containing the property that caused user might appreciate having the pre/postcondition most frequently
searched properties be displayed on-screen, rather than having to fail.
If DAV:prop
scroll through a long list of searchable properties. One mechanism
for signaling the most frequently searched properties is specified in to return
them towards the request body, start of a list of properties. A client can then
preferentially display the list of properties
specified in order, increasing
the DAV:prop element MUST be reported in likelihood that the
DAV:response elements.
Preconditions:
None
Postconditions:
(DAV:number-of-matches-within-limits): most frequently searched properties will
appear on-screen, and will not require scrolling for their
selection.
Marshalling:
The number of matching
principals must fall within server-specific, predefined limits.
For example, this condition might request body MUST be triggered if a search
specification would cause the return of an extremely large number
of responses.
9.4.1 Matching
There are several cases to consider when matching strings. The
easiest case is when a property value empty
DAV:principal-search-property-set XML element.
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 MUST be a DAV:principal-search-property-set XML
element, containing a DAV:principal-search-property XML element
information item, and the character information item content of
the
for each property is "Julian Reschke".
Clemm, Hopkins, Sedlar, Whitehead [Page 45] that may be searched with the
DAV:principal-property-search REPORT. A more complicated case occurs when properties have mixed content
(that is, compound values consisting of multiple child element
items, other types server MAY limit its
response to just a subset of information items, 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 XML element contains exactly
one searchable property, and character information
item content). Consider a description of the property.
<!ELEMENT principal-search-property (prop, description) >
The DAV:prop element contains one principal property "aprop" in on which 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
server is performed on each individual contiguous
sequence able to perform a DAV:principal-property-search REPORT.
prop: see RFC 2518, Section 12.11
The description element is a human-readable description of character what
information items. In this property represents. Servers MUST indicate the example above, a
search string would be compared to
human language of the 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}, description using the xml:lang attribute and {cdata 3}.
9.4.2
SHOULD consider the HTTP Accept-Language request header when
selecting one of multiple available languages.
<!ELEMENT description #PCDATA >
9.5.1 Example: successful DAV:principal-property-search DAV:principal-search-property-set REPORT
In this example, the client requests determines the principal URLs set of all
users whose DAV:displayname property contains the substring "doE"
and whose "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 matching principals:
In the DAV: namespace: displayname
In the http://www.example.com/ns/ namespace: department, phone,
office, salary
The response shows that two principal resources meet the search
specification, "John Doe" and "Zygdoebert Smith". The property
"salary" in namespace "http://www.example.com/ns/" is not
returned, since the searchable
principal making the request does not have
sufficient access permissions to read this property. 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 charset="utf-8"
Content-Length: xxxx xxx
Accept-Language: en, de
Authorization: BASIC d2FubmFtYWs6cGFzc3dvcmQ=
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>
Clemm, Hopkins, Sedlar, Whitehead [Page 46]
<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>
<D:principal-search-property-set xmlns:D="DAV:"/>
>> Response <<
HTTP/1.1 207 Multi-Status 200 OK
Content-Type: text/xml; charset=utf-8 charset="utf-8"
Content-Length: xxxx xxx
<?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>
<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:principal-search-property-set xmlns:D="DAV:">
<D:principal-search-property>
<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/>
</D:prop>
Clemm, Hopkins, Sedlar, Whitehead [Page 47]
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
<D:propstat>
<D:prop>
<B:salary/>
<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: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 may be searched using the DAV:principal-property-
search REPORT (defined in Section 9.4).
Servers
<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 DAV:principal-search-property-set REPORT
on all collections identified XML element
ignore rule, as specified in the value Section 23.3.2 of a DAV:principal-
collection-set property.
An access control protocol user agent could use [RFC2518], and the results XML
Namespace recommendation [REC-XML-NAMES].
Note that use of the
DAV:principal-search-property-set REPORT to present a query
interface to the user for retrieving principals.
Support for this report DAV namespace is REQUIRED.
Implementation Note: Some clients will have only limited screen
real estate reserved for the display of lists of searchable properties.
In this case, XML elements and
property names defined in a user might appreciate having standards-track or Experimental IETF RFC.
11. Internationalization Considerations
In this specification, the most
frequently searched properties only human-readable content can be displayed on-screen, rather
than having to scroll through a long list of searchable
properties. One mechanism for signaling found
in the most frequently
searched properties is to return them towards description XML element, found within the start of
DAV:supported-privilege-set property. This element contains a
list
human-readable description of properties. A client can then preferentially display the list capabilities controlled by a
privilege. As a result, the description element must be capable of properties
representing descriptions in order, increasing multiple character sets. Since the likelihood that
description element is found within a WebDAV property, it is
represented on the most frequently searched properties will appear on-screen, wire as XML [REC-XML], and will not require scrolling for their selection.
Marshalling:
The request body MUST be an empty DAV:principal-search-property- hence can leverage
XML's language tagging and character set encoding capabilities.
Specifically, XML element.
This report is only defined when processors at minimum must be able to read XML
elements encoded using the Depth header has value "0";
other values result UTF-8 [RFC3629] encoding of the ISO 10646
multilingual plane. XML examples in a 400 (Bad Request) error response. Note
that [RFC3253], Section 3.6, states that if this specification demonstrate
use of the Depth header is
not present, it defaults to a value charset parameter of "0".
The response body MUST be a DAV:principal-search-property-set XML
element, containing a DAV:principal-search-property the Content-Type header, as defined
in [RFC3023], as well as the XML element "encoding" attribute, which together
provide charset identification information for each property that may be searched MIME and XML
processors. Futhermore, this specification requires server
implementations to tag description fields with the DAV:principal-
property-search REPORT. A xml:lang attribute
(see Section 2.12 of [REC-XML]), which specifies the human language
of the description. Additionally, server MAY limit its response to just a
subset implementations should take
into account the value of the searchable properties, such as those likely Accept-Language HTTP header to be
useful
determine which description string to an interactive access control client.
Clemm, Hopkins, Sedlar, Whitehead [Page 48]
<!ELEMENT principal-search-property-set (principal-search-
property*) >
Each DAV:principal-search-property return.
For XML element contains exactly
one searchable property, and a elements other than the description of element, it is expected
that implementations will treat the property.
<!ELEMENT principal-search-property (prop, description) >
The DAV:prop element contains one principal property on which names, privilege names,
and values as tokens, and convert these tokens into human-readable
text in the
server is able user's language and character set when displayed to perform a DAV:principal-property-search REPORT.
prop: see RFC 2518, Section 12.11
The description element is
person. Only a human-readable description of what
information this generic WebDAV property represents. Servers MUST indicate the display utility would display
these values in their raw form to a human language of user.
For error reporting, we follow the convention of HTTP/1.1 status
codes, including with each status code a short, English description using
of the xml:lang attribute code (e.g., 200 (OK)). While the possibility exists that a
poorly crafted user agent would display this message to a user,
internationalized applications will ignore this message, and
SHOULD consider display
an appropriate message in the HTTP Accept-Language request header when
selecting one 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 multiple available languages.
<!ELEMENT description #PCDATA >
9.5.1 Example: DAV:principal-search-property-set REPORT
In this example, the client determines the set access control protocol should be
aware of searchable
principal properties by requesting several security considerations, detailed below. In addition
to the DAV:principal-search-
property-set REPORT on discussion in this document, the root of security considerations
detailed in 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>
Clemm, Hopkins, Sedlar, Whitehead [Page 49]
<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 [RFC2616], the XML element
ignore rule, as specified in Section 23.3.2 of WebDAV
Distributed Authoring Protocol specification [RFC2518], and the XML Namespace recommendation [REC-XML-NAMES].
Note that use of the DAV namespace is reserved for XML elements
and property names defined
Media Types specification [RFC3023] should be considered in a standards-track or Experimental
IETF RFC.
11 INTERNATIONALIZATION CONSIDERATIONS
In
security analysis of this specification, 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 human-readable content those resources for which the user has access
permission can be
found in read, modified, moved, or deleted. With the description XML element, found within
introduction of this access control protocol, if a single compromised
user has the
DAV:supported-privilege-set property. This element contains ability to change ACLs for a
human-readable description broad range of other users
(e.g., a super-user), the capabilities controlled number of resources that could be altered
by a
privilege. As a result, the description element must single compromised user increases. This risk can be capable
of representing descriptions in multiple character sets. Since mitigated by
limiting the description element is found within number of people who have write-acl privileges across a WebDAV property, it is
represented on
broad range of resources.
12.2 Risks of the wire as XML [REC-XML], and hence can leverage
XML's language tagging DAV:read-acl and character set encoding capabilities.
Specifically, XML processors at minimum must be able DAV:current-user-privilege-set
Privileges
The ability to read XML
elements encoded using the UTF-8 [UTF-8] encoding of access privileges (stored in the ISO 10646
multilingual plane. XML examples DAV:acl
property), or the privileges permitted the currently authenticated
user (stored in this specification demonstrate
use of the charset parameter of DAV:current-user-privilege-set property) on a
resource may seem innocuous, since reading an ACL cannot possibly
affect the Content-Type header, as
defined 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 [RFC3023], as well a
vulnerable state, such as being world-writeable. In particular, the XML "encoding" attribute,
which together provide charset identification information for MIME
and XML processors. Futhermore, this specification requires server
implementations to tag description fields
property retrieval method PROPFIND, executed 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 Depth infinity on
an entire hierarchy, is a very efficient way to determine retrieve the DAV:acl
or DAV:current-user-privilege-set properties. Once found, this
vulnerability can be exploited by a denial of service attack in which description string to
return.
For XML elements other than
the description element, it open resource is
expected that implementations will treat the property names,
privilege names, and values as tokens, and convert these tokens
into human-readable text repeatedly overwritten. Alternately, writeable
resources can be modified in the user's language undesirable ways.
To reduce this risk, read-acl privileges should not be granted to
unauthenticated principals, and character set restrictions on read-acl and
read-current-user-privilege-set privileges for authenticated
principals should be carefully analyzed when displayed to a person. Only a generic WebDAV property
display utility would display these values in their raw form deploying this protocol.
Access to a
human user.
For error reporting, we follow the convention of HTTP/1.1 status
codes, including with each status code current-user-privilege-set property will involve a short, English
description
tradeoff of usability versus security. When the code (e.g., 200 (OK)). While the possibility
Clemm, Hopkins, Sedlar, Whitehead [Page 50]
exists that a poorly crafted
current-user-privilege-set is visible, user agent would display this message interfaces are expected
to a user, internationalized applications will ignore this
message, and display an appropriate message in the user's language provide enhanced information concerning permitted and character set.
Further internationalization considerations for restricted
operations, yet this information may also indicate a vulnerability
that could be exploited. Deployment of this protocol are
described will need to
evaluate this tradeoff in light of the WebDAV Distributed Authoring protocol
specification [RFC2518].
12 SECURITY CONSIDERATIONS
Applications and users requirements of this access control protocol should be
aware the deployment
environment.
12.3 No Foreknowledge of several security considerations, detailed below. Initial ACL
In
addition an effort to the discussion in reduce protocol complexity, this document, the security
considerations detailed in the HTTP/1.1 specification [RFC2616],
the WebDAV Distributed Authoring Protocol protocol
specification [RFC2518],
and intentionally does not address the XML Media Types specification [RFC3023] should be
considered in a security analysis of this protocol.
12.1 Increased Risk issue of Compromised Users
In how to
manage or discover the absence of a mechanism for remotely manipulating access
control lists, if initial ACL that is placed upon a single user's authentication credentials are
compromised, resource
when it is created. The only those resources for which way to discover the user has access
permission can be read, modified, moved, or deleted. With initial ACL is to
create a new resource, then retrieve the
introduction value of this access control protocol, if a single
compromised user the DAV:acl
property. This assumes the principal creating the resource also has
been granted the ability to change ACLs for DAV:read-acl privilege.
As a broad range
of other users (e.g., result, it is possible that a super-user), the number of resources principal could create a resource,
and then discover that its ACL grants privileges that are
undesirable. Furthermore, this protocol makes it possible (though
unlikely) that the creating principal could be altered by unable to modify the
ACL, or even delete the resource. Even when the ACL can be modified,
there will be a single compromised user increases. This risk short period of time when the resource exists with
the initial ACL before its new ACL can be mitigated by 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 number of people who have write-
acl
privileges across a broad range of resources.
12.2 Risks of granted by the DAV:read-acl initial ACL.
13. Authentication
Authentication mechanisms defined for use with HTTP and DAV:current-user-privilege-set
Privileges
The ability WebDAV also
apply to read this WebDAV Access Control Protocol, in particular the access privileges (stored Basic
and Digest authentication mechanisms defined in [RFC2617].
Implementation of the DAV:acl
property), or ACL spec requires that Basic authentication, if
used, MUST only be supported over secure transport such as TLS.
14. IANA Considerations
This document uses the privileges permitted namespace defined by [RFC2518] for XML
elements. That is, this specification uses the currently authenticated
user (stored "DAV:" URI namespace,
previously registered in the DAV:current-user-privilege-set property) on a
resource may seem innocuous, since reading an 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 the WebDAV ACL cannot possibly
affect design
team: Bernard Chester, Geoff Clemm, Anne Hopkins, Barry Lind, Sean
Lyndersay, Eric Sedlar, Greg Stein, and Jim Whitehead. The authors
are grateful for the resource's state. However, if all resources have world-
readable ACLs, it is possible to perform an exhaustive search 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 for
those resources that have inadvertently left themselves in a
vulnerable state, such as being world-writeable. In particular, the
initial text of the principal property retrieval method PROPFIND, executed with Depth
infinity search sections. Prior work on an entire hierarchy, is a very efficient way
WebDAV access control protocols has been performed by Yaron Goland,
Paul Leach, Lisa Dusseault, Howard Palmer, and Jon Radoff. We would
like to
retrieve acknowledge the DAV:acl or DAV:current-user-privilege-set properties.
Once found, this vulnerability can be exploited foundation laid for us by a denial the authors of
service attack in which the open resource
DeltaV, WebDAV and HTTP protocols upon which this protocol is repeatedly
overwritten. Alternately, writeable resources can be modified
layered, and the invaluable feedback from 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]
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
undesirable ways.
To reduce this risk, read-acl privileges should not be granted
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
unauthenticated principals, and restrictions on read-acl Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2518] Goland, Y., Whitehead, E., Faizi, A., Carter, S. and read-
current-user-privilege-set privileges D.
Jensen, "HTTP Extensions for authenticated principals
should be carefully analyzed when deploying this protocol. 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 1999.
[RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S.,
Leach, P., Luotonen, A. and L. Stewart, "HTTP
Authentication: Basic and Digest Access Authentication",
RFC 2617, June 1999.
[RFC3023] Makoto, M., St.Laurent, S. and D. Kohn, "XML Media Types",
RFC 3023, January 2001.
[RFC3253] Clemm, Hopkins, Sedlar, Whitehead [Page 51]
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 G., Amsden, J., Ellison, T., Kaler, C. 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 J.
Whitehead, "Versioning Extensions to
create 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 new resource, then retrieve the value transformation format 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, 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. and then discover that its ACL grants privileges that
are undesirable. Furthermore, S. Kille, "Lightweight Directory
Access Protocol (v3)", RFC 2251, December 1997.
[RFC2255] Howes, T. and 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 [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
J. Whitehead
U.C. Santa Cruz, Dept. of Computer Science
1156 High Street
Santa Cruz, CA 95064
EMail: ejw@cse.ucsc.edu
Appendix A. WebDAV XML Document Type Definition Addendum
All XML elements defined in this protocol makes it possible
(though unlikely) that the creating principal could be unable Document Type Definition (DTD)
belong 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 exists with the initial ACL before its new ACL can DAV namespace. This DTD should be
set.
Several factors mitigate this risk. Human principals are often
aware of viewed as an addendum
to the default access permissions DTD provided in their editing
environments and take this into account when writing information.
Furthermore, default [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>
<!-- 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 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 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) -->
<!ELEMENT principal-collection-set (href*)>
<!-- Access Control Protocol, in particular
the Basic and Digest authentication mechanisms defined in
[RFC2617]. Implementation of the Existing Methods (Section 7) -->
<!ELEMENT need-privileges (resource)* >
<!ELEMENT resource ( href, privilege )
<!-- ACL spec requires 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] for XML
elements. That is, this specification uses the "DAV:" URI
namespace, previously registered in the URI schemes registry. All
other IANA considerations mentioned in [RFC2518] are also
applicable to this specification.
Clemm, Hopkins, Sedlar, Whitehead [Page 52]
15 INTELLECTUAL PROPERTY 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 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 following notice
expectation is copied from RFC 2026, section 10.4, and
describes the position value of the IETF concerning intellectual
property claims made against this document.
The IETF takes no position regarding the validity or scope of any
intellectual named property or other rights that might be claimed to
pertain to the implementation or use other technology described in
this document or the extent to which any license under such rights
might or might not be available; neither does it represent typically contains
an href element that it
has made any effort to identify any such rights. Information on
the IETF's procedures with respect to rights in standards-track
and standards-related documentation can be found in BCP-11. Copies
of claims of rights made available for publication and any
assurances of licenses to be made available, or contains the result URI of an
attempt made to obtain a general license or permission for the use
of such proprietary rights by implementers or users 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. WebDAV Method Privilege Table (Normative)
The following table of this
specification can be obtained from WebDAV methods (as defined in RFC 2518, 2616,
and 3253) clarifies which privileges are required for access for each
method. Note that the IETF Secretariat.
The IETF invites any interested party to bring privileges listed, if denied, MUST cause
access to its attention
any copyrights, patents or patent applications, or other
proprietary rights that may cover technology that may be required denied. However, given that a specific implementation
MAY define an additional custom privilege to practice this standard. Please address the information control access to the
IETF Executive Director.
16 ACKNOWLEDGEMENTS
This protocol is the collaborative product
existing methods, having all of the WebDAV ACL
design team: Bernard Chester, Geoff Clemm, Anne Hopkins, Barry
Lind, Sean Lyndersay, Eric Sedlar, Greg Stein, and Jim Whitehead.
The authors are grateful for indicated privileges does not
mean that access will be granted. Note that lack of 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 for indicated
privileges does not imply that access will be denied, since a
particular implementation may use a sub-privilege aggregated under
the initial text of indicated privilege to control access. Privileges required refer
to the principal property
search sections. Prior work current resource being processed unless otherwise specified.
+---------------------------------+---------------------------------+
| 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 WebDAV access control protocols has
been performed by Yaron Goland, Paul Leach, Lisa Dusseault, Howard
Palmer, and Jon Radoff. We would like to acknowledge the
foundation laid for us by the authors parent collection |
| | of the DeltaV, WebDAV target |
| PROPPATCH | <D:write-properties> |
| ACL | <D:write-acl> |
| PROPFIND | <D:read> (plus <D:read-acl> and
HTTP protocols upon which this protocol is layered, |
| | <D:read-current-user-privilege- |
| | set> as needed) |
| COPY (target exists) | <D:read>, <D:write-content> and the
invaluable feedback from the WebDAV working group.
17 REFERENCES
17.1 Normative References
[RFC2119] S.Bradner, "Key words for use in RFCs to Indicate
Requirement Levels." RFC 2119, BCP 14, March, 1997.
[REC-XML] T. Bray, J. Paoli, C.M. Sperberg-McQueen, "Extensible
Markup Language (XML)." World Wide Web Consortium Recommendation
REC-xml.http://www.w3.org/TR/REC-xml
Clemm, Hopkins, Sedlar, Whitehead [Page 53]
[REC-XML-NAMES] T. Bray, D. Hollander, A. Layman, "Name Spaces in
XML" World Wide Web Consortium Recommendation REC-xml-names.
http://www.w3.org/TR/REC-xml-names/
[RFC3253] G. Clemm, J. Amsden, T. Ellison, C. Kaler, J. Whitehead,
"Versioning Extensions to WebDAV." RFC 3253, March 2002.
[REC-XML-INFOSET] J. Cowan, R. Tobin, "XML Information Set." World
Wide Web Consortium Recommendation REC-xml-infoset.
http://www.w3.org/TR/xml-infoset/
[RFC2616] R. Fielding, J. Gettys, J. C. Mogul, H. Frystyk, L.
Masinter, P. Leach, |
| | <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 T. Berners-Lee, "Hypertext Transfer
Protocol -- HTTP/1.1." RFC 2616, June, 1999.
[RFC2617] J. Franks, P. Hallam-Baker, J. Hostetler, S. Lawrence,
P. Leach, A. Luotonen, L. Stewart, "HTTP Authentication: Basic <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> and
Digest Access Authentication." RFC 2617, June, 1999.
[RFC2518] Y. Goland, E. Whitehead, A. Faizi, S. R. Carter, D.
Jensen, "HTTP Extensions for Distributed Authoring -- WEBDAV." RFC
2518, February, 1999.
[RFC2368] P. Hoffman, L. Masinter, J. Zawinski, "The mailto URL
scheme." RFC 2368, July, 1998.
[RFC3023] M. Murata, S. St.Laurent, D. Kohn, "XML Media Types."
RFC 3023, January, 2001.
[RFC3010] S. Shepler, B. Callaghan, D. Robinson, R. Thurlow, |
| | <D:write-content> |
| MKACTIVITY | <D:write-content> on parent |
| | collection |
+---------------------------------+---------------------------------+
Appendix C.
Beame, M. Eisler, D.Noveck "NFS version 4 Protocol." Resolved issues (to be removed by RFC 3010,
December 2000.
[UTF-8] F. Yergeau, "UTF-8, a transformation format Editor before
publication)
Issues that were either rejected or resolved in this version of Unicode
and ISO 10646." RFC 2279, January, 1998.
17.2 Informational References
[RFC2026] S.Bradner, "The Internet Standards Process - Revision
3." RFC 2026, BCP 9. Harvard, October, 1996.
[RFC2255] T. Howes, M. Smith, "The LDAP URL Format." RFC 2255.
Netscape, December, 1997.
[RFC2251] M. Wahl, T. Howes, S. Kille, "Lightweight Directory
Access Protocol (v3)." RFC 2251. Critical Angle, Netscape, Isode,
December, 1997.
[CaseMap] M. Davis, "Case Mappings", Unicode Standard Annex #21,
March 26, 2001. http://www.unicode.org/unicode/reports/tr21
Clemm, Hopkins, Sedlar, Whitehead [Page 54]
18 AUTHORS' ADDRESSES
Geoffrey Clemm
IBM
20 Maguire Road
Lexington, MA 02421
Email: 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
Microsoft Corporation
One Microsoft Way
Redmond, WA 98052
Email: annehop@microsoft.com
Eric Sedlar
Oracle Corporation
500 Oracle Parkway
Redwood Shores, CA 94065
Email: eric.sedlar@oracle.com
Jim Whitehead
U.C. Santa Cruz
Dept. from
authors list (keep her name in the Acknowledgements section).
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 Computer Science
Baskin Engineering
1156 High Street
Santa Cruz, CA 95064
Email: ejw@cse.ucsc.edu
Clemm, Hopkins, Sedlar, Whitehead [Page 55]
19 APPENDICES
19.1 WebDAV 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 Document Type Definition Addendum
All examples
Resolution (2003-11-04): Several XML elements defined message bodies fixed (no change
tracking).
C.8 1_ref_options
Type: edit
<http://mailman.webdav.org/pipermail/acl/2003-November/001718.html>
julian.reschke@greenbytes.de (2003-11-04): "Client discovery 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" 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 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 is not an
aggregate why does it exist?
Resolution (2003-11-18): Update description 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 an unmapped URI (creating a new resource, requiring
privileges on the parent collection). Define aggregation of DAV:bind
and DAV:unbind in 3.12.
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 this Document Type Definition (DTD)
belong to 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 DAV namespace. This DTD
server can't provide the information.
Resolution (2003-11-08): Added paragraphs stating both for both
properties.
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 viewed as an
addendum to
optional in case the server doesn't have owner information.
Resolution (2003-11-06): Updated DTD provided 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 in [RFC2518], example 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 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:supported-privilege-set Property (Section 5.2) -->
<!ELEMENT supported-privilege-set (supported-privilege*)>
<!ELEMENT supported-privilege
(privilege, abstract?, description, supported-privilege*)>
<!ELEMENT numbering
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 the XML response
should be rolled back. "delete" is a custom privilege in the
example.
Resolution (2003-11-04): Changed example response back to use
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 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 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 not essential, can this
example rewritten without 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 a particular vendor wants to add <vendor:group>
that's great, but I think we are going to have minimal
interoperability with this. We discussed this before 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
DAV:no-invert should refer to section 5.5.2 for 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 and Section
19.2 to Appendix B.
Index
A
ACL method 41
C
Condition Names
DAV:allowed-principal (pre) 43
DAV:deny-before-grant (pre) 43
DAV:grant-only (pre) 43
DAV:limited-number-of-aces (pre) 43
DAV:missing-required-principal (pre) 43
DAV:no-abstract (pre) 43
DAV:no-ace-conflict (pre) 42
DAV:no-inherited-ace-conflict (pre) 42
DAV:no-invert (pre) 43
DAV:no-protected-ace-conflict (pre) 42
DAV:not-supported-privilege (pre) 43
DAV:number-of-matches-within-limits (post) 50, 55
DAV:recognized-principal (pre) 43
D
DAV header
compliance class 'access-control' 40
DAV:acl property 24
DAV:acl-principal-prop-set report 49
DAV:acl-restrictions property 28
DAV:all privilege ANY>
<!ELEMENT abstract EMPTY>
<!ELEMENT description #PCDATA>
<!-- 13
DAV:allowed-principal precondition 43
DAV:alternate-URI-set property 14
DAV:bind privilege 13
DAV:current-user-privilege-set Property (Section 5.3) -->
<!ELEMENT current-user-privilege-set (privilege*)>
Clemm, Hopkins, Sedlar, Whitehead [Page 56]
<!-- DAV:acl Property (Section 5.4) -->
<!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 22
DAV:deny-before-grant precondition 43
DAV:grant-only precondition 43
DAV:group property ANY>
<!ELEMENT self EMPTY>
<!ELEMENT invert principal>
<!ELEMENT grant (privilege+)>
<!ELEMENT deny (privilege+)>
<!ELEMENT 18
DAV:group-member-set property 15
DAV:group-membership property 15
DAV:inherited-acl-set property 31
DAV:limited-number-of-aces precondition 43
DAV:missing-required-principal precondition 43
DAV:no-abstract precondition 43
DAV:no-ace-conflict precondition 42
DAV:no-inherited-ace-conflict precondition 42
DAV:no-invert precondition 43
DAV:no-protected-ace-conflict precondition 42
DAV:not-supported-privilege precondition 43
DAV:number-of-matches-within-limits postcondition 50, 55
DAV:owner property 16
DAV:principal resource type 14
DAV:principal-collection-set property 31
DAV:principal-match report 51
DAV:principal-property-search 53
DAV:principal-search-property-set 58
DAV:principal-URL property 15
DAV:read privilege ANY>
<!ELEMENT protected EMPTY>
<!ELEMENT inherited (href)>
<!-- 10
DAV:read-acl privilege 12
DAV:read-current-user-privilege-set privilege 12
DAV:recognized-principal precondition 43
DAV:supported-privilege-set property 19
DAV:unbind privilege 13
DAV:unlock privilege 12
DAV:write privilege 11
DAV:write-acl privilege 13
DAV:write-content privilege 11
DAV:write-properties privilege 11
M
Methods
ACL 41
P
Privileges
DAV:all 13
DAV:bind 13
DAV:read 10
DAV:read-acl 12
DAV:read-current-user-privilege-set 12
DAV:unbind 13
DAV:unlock 12
DAV:write 11
DAV:write-acl 13
DAV:write-content 11
DAV:write-properties 11
Properties
DAV:acl 24
DAV:acl-restrictions Property (Section 5.5) -->
<!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*)>
Clemm, Hopkins, Sedlar, Whitehead [Page 57]
<!-- 28
DAV:alternate-URI-set 14
DAV:current-user-privilege-set 22
DAV:group 18
DAV:group-member-set 15
DAV:group-membership 15
DAV:inherited-acl-set Property (Section 5.6) -->
<!ELEMENT inherited-acl-set (href*)>
<!-- 31
DAV:owner 16
DAV:principal-collection-set 31
DAV:principal-URL 15
DAV:supported-privilege-set 19
R
Reports
DAV:acl-principal-prop-set 49
DAV:principal-match 51
DAV:principal-property-search 53
DAV:principal-search-property-set 58
Resource Types
DAV:principal 14
Intellectual Property (Section 5.6) -->
<!ELEMENT principal-collection-set (href*)>
<!-- Access Control Statement
The IETF takes no position regarding the validity or scope of any
intellectual property or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; neither does it represent that it
has made any effort to identify any such rights. Information on the
IETF's procedures with respect to rights in standards-track 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
standards-related documentation can be found in BCP-11. Copies of one
claims of rights made available for publication and any assurances of
licenses to be made available, 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 the value result of the named property typically contains an href element that contains attempt made to
obtain a general license or permission for the URI use 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 >
19.2 WebDAV Method Privilege Table (Normative)
The following table such
proprietary rights by implementors or users of WebDAV methods (as defined in RFC 2518, 2616,
and 3253) clarifies which privileges are required for access for each
method. Note that this specification can
be obtained from the privileges listed, if denied, MUST cause access IETF Secretariat.
The IETF invites any interested party to be denied. However, given bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights which may cover technology that a specific implementation MAY define
an additional custom privilege may be required to control access practice
this standard. Please address the information to existing methods,
having all of the indicated privileges does not mean IETF Executive
Director.
Full Copyright Statement
Copyright (C) The Internet Society (2003). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that access will
Clemm, Hopkins, Sedlar, Whitehead [Page 58] comment on or otherwise explain it
or assist in its implementation may be granted. Note prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that lack of the indicated privileges does above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not imply
that access will be denied, since a particular implementation may use a
sub-privilege aggregated under modified in any way, such as by removing
the indicated privilege to control
access. Privileges required refer copyright notice or references to the current resource being
processed unless otherwise specified.
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 Internet Society or other
Internet organizations, except as needed for the purpose of target
PROPPATCH <D:write-properties>
ACL <D:write-acl>
PROPFIND <D:read> (plus <D:read-acl> and
<D:read-current-user-privilege-set>
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or 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 required to translate it into languages other than
English.
The limited permissions granted above are perpetual and <D:bind>
on target collection
MOVE (target exists) As above, plus <D:unbind> on will not be
revoked by 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> Internet Society or its successors or assignees.
This document and <D:write-content>
MKACTIVITY <D:write-content> the information contained herein is provided on parent collection
Clemm, Hopkins, Sedlar, Whitehead [Page 59] an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Acknowledgment
Funding for the RFC Editor function is currently provided by the
Internet Society.