INTERNET-DRAFT P. J. Leach
Expires: April 1998 Y. Y. Goland
Standards Track Microsoft Eric Sedlar, Oracle Corporation
WebDAV Working Group
draft-ietf-webdav-acl-01.txt Geoffrey Clemm, Rational Software
Expires November 10, 1997 1, 2000 May 1, 2000
Access Control Extensions to WebDAV ACL Protocol
draft-ietf-webdav-acl-00.txt
Status of this Memo
This document is an Internet-Draft. Internet-Draft and is in full conformance with all
provisions of Section 10 of RFC2026.
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Abstract
This memo document specifies the format a set of methods, headers, and manipulation mechanisms for
access control lists (ACLs) for resource-types
that define the WebDAV objects.
Contents
Status Access Control extensions to the HTTP/1.1
protocol.
Sedlar, Clemm [Page 1]
Table of this Memo................................................1
Abstract...........................................................1
Contents...........................................................1
1. Introduction....................................................2
2. Principals Identifiers..........................................2
3. Granting and Denying Rights.....................................3
4. ACL Inheritance.................................................4
5. Properties and ACLs.............................................4
6. Contents
1 INTRODUCTION............................................3
1.1 Notational Conventions................................3
2 PRINCIPALS..............................................3
3 RIGHTS..................................................4
3.1 RIGHTS-DISCOVERY method...............................5
3.2 Rights Definitions..............................................5
7. Default Principal Types.........................................7
8. ACL Method......................................................7
9. Examples.......................................................11
10.Authors' Addresses.............................................13
11.Bibliography...................................................14
1. Introduction defined by WebDAV..............................6
3.2.1 read Right........................................6
3.2.2 write Right.......................................6
3.2.3 readacl Right.....................................6
3.2.4 writeacl Right....................................6
3.2.5 all Right.........................................6
4 ACCESS CONTROL PROPERTIES...............................7
4.1 Example 1 - Retrieving Access Control information.....8
5 USING ACLS..............................................9
6 ACL METHOD.............................................10
6.1 Example 1 - Setting ACLs.............................10
7 ACL INHERITANCE / DEFAULT ACLS.........................11
8 XML SCHEMA FOR DEFINED ELEMENTS........................12
9 INTERNATIONALIZATION CONSIDERATIONS....................13
10 SECURITY CONSIDERATIONS..............................13
11 SCALABILITY..........................................13
12 AUTHENTICATION.......................................13
13 IANA CONSIDERATIONS..................................13
14 INTELLECTUAL PROPERTY................................13
15 ACKNOWLEDGEMENTS.....................................14
16 INDEX................................................14
17 REFERENCES...........................................14
18 AUTHORS' ADDRESSES...................................15
19 STILL TO DO :........................................15
Sedlar, Clemm [Page 2]
1 INTRODUCTION
The basic model for underlying principle of access control, informally expressed, control is that who you are
determines how you can access a resource. The "who you are" is
defined by a principal "principal" identifier; users, client software,
servers
servers, and groups of the previous have principal identifiers.
The "how" is determined by an "access control list" (ACL)
associated with a resource. An ACL contains Access Control Elements (ACE). An ACE specifies a set of principals, "access
control entries" (ACEs), where each ACE specifies a set of granted rights, principal and
a set of denied
rights.
Rights may be generic, such as "read", "write", or "delete", rights that are either granted or they
might be specific denied to the kind of resource protected by that ACL,
such as (perhaps) "send-to", "unsubscribe", and "administer" for
mailing lists.
When a resource
principal.
1.1 Notational Conventions
The augmented BNF used by this document to describe protocol
elements is created it inherits a set described in Section 2.1 of default ACL
properties from a designated resource, referred [RFC2068]. Because this
augmented BNF uses the basic production rules provided in Section
2.2 of [RFC2068], those rules apply to this document as an ACL source. well.
The inheritance can key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be "static", so interpreted as described in
[RFC2119].
2 PRINCIPALS
A principal identifies an entity that subsequent changes can be given access rights
to the
ACL source do not effect the new resources ACL properties; HTTP resources. On many implementations, a user or it can a group
will be "dynamic", so that subsequent changes examples of principals, but other types of principals are reflected in the new
resource's ACL properties.
Properties on a resource, by default, dynamically inherit from the
ACL on
possible. For the resource. In most part, any classification or other words,
information about the resource entity identified by a principal is opaque
with respect to this specification, and is dependent on the ACL source
for the properties. However individual properties can be given their
own ACL.
2.
implementation.
Principals Identifiers are manifested to clients as a HTTP resource,
identified by a URL. The set of properties exposed by that
resource are implementation dependent, although certain
properties are required by this specification. Those properties
include:
@ <dav:principalname>: A "live" property containing the
name used to authenticate this principal identifier can identify
(typically typed into a single principal or login prompt/dialog).
[OPTIONAL]
@ <dav:displayname>: A property containing a compound human-readable
description of this principal. This property
may be "live" and not settable via PROPPATCH.
[REQUIRED]
@ <dav:principal-type>: A single principal identifier refers to "live" property containing a single
principal, such
classification word for this principal. The
values <dav:user/> and <dav:group/> are
choices for value of this property
recommended by this spec. The presence of
Sedlar, Clemm [Page 3]
this property can be used to distinguish it
as a person or principal from other resources on a program. A compound
WebDAV server. (Note that <dav:resourcetype>
may not be used, as all collections must use
the value "collection" for <resourcetype>,
which wouldn't distinguish normal collections
from principal
identifier specifies one or more principals. collections.) [REQUIRED]
Server implementations may include any other descriptive
information for a principal via properties.
A compound principal resource may or may not necessarily just be a list collection. A
collection principal may only contain other principals (not other
types of resources). Servers that support aggregation of
principals (e.g. groups of users or other groups) MUST manifest
them as collection principals. It The WebDAV methods for examining
maintaining collections (e.g. BIND, DELETE, PROPFIND) may in
fact be used
to maintain collection principals. Membership in a program that accepts collection
principal is recusive, so a principal identifier as input and
output true or false to indicate membership.
This specification relies upon in a collection principal A
contained by collection principal B is a member of both
collection principals. Implementations not supporting recursive
membership in principal collections can return an error if the underlying authentication
mechanism(s)
client attempts to provide bind collection principals into other
collection principals. Using WebDAV methods to alter the syntax content
of a principal identifiers. Thus,
for (e.g. using PROPPATCH or PUT) is outside the purposes scope
of this specification, principal identifiers are
opaque.
3. Granting and Denying Rights
An ACL can both grant and deny rights. The reason both types of
grants are required is because not required, recommended, or
forbidden by this spec.
3 RIGHTS
A right controls access to a particular set of compound principals. HTTP operations on
a resource. The consequence of the existence set of compound principals is rights that
there are times when apply to a compound principal particular
resource may be granted a right but
a particular member vary with the <dav:resourcetype> of the compound principal may need to resource, as
well as between different server implementations. To promote
interoperability, however, WebDAV defines a set of well-known
rights (e.g. <dav:read> and <dav:write>), which can at least be denied
access. In order
used to make this possible an ACL must be able set some context to list
principals both allowed and denied a right.
By default all the other rights for defined on a principal MUST be denied.
particular resource.
Rights MAY
only may be granted to a principal by an explicit listing of that
principal in a "grant" section aggregates of an ACL.
Additionally it is possible for access rights to collide in scope. other rights. For example, a container one
implementation may have an access split out a right which specifies controlling the ability of principals to delete the
BIND children of that container.
This would affect into a collection from the right allowing a
resource to be removed from a principal's collection. Since these rights
control the ability to use write to a collection, these rights would
be aggregated by the DELETE method.
However <dav:write> right. The relationships
between atomic rights and aggregate rights can be discovered via
the RIGHTS-DISCOVERY HTTP method on a particular internal child resource.
Servers may have granted access specify some rights as abstract, which means that it
may not appear in an ACL, but is described in the RIGHTS-
DISCOVERY method to aid in setting context. Server
implementations must return the same response to DELETE. As such, the two RIGHTS-
DISCOVERY method on all of the resources with the same
<dav:resourcetype> value.
Sedlar, Clemm [Page 4]
3.1 RIGHTS-DISCOVERY method
Rights discovery is a method with no arguments, that returns the
rights could collide.
The aggregation tree. Each right appears as an XML element,
where aggregate rights list all of their children as sub-
elements. Each right element can contain the following rules, processed in order, MUST
attributes:
@ abstract (Boolean): "true" if this right cannot be used in
an ACL/ACE. Defaults to resolve
scope conflicts between rights.
1) In a conflict between a "false"
@ description (string): a human readable description of what
this right granted by controls access to. Required.
For example, the following response might be generated to a parent and
RIGHTS-DISCOVERY request on a right
granted WebDAV server implemented by a child,
relational database (where the right specified by the child MUST override.
2) In a conflict between resource in this case corresponds
to a right granted or denied to table):
Request
RIGHTS-DISCOVERY /schemas/scott/emp HTTP/1.1
Host: www.foo.bar
Content-type: text/xml; charset="utf-8"
Content-Length: 0
Response
HTTP/1.1 200 Success
Content-Type: text/xml
Content-Length: xxxxx
<?xml version="1.0" encoding="utf-8" ?>
<?namespace href = "http://www.oracle.com/webdav/ AS = ORA"?>
<D:response>
<D:all abstract=true description="All access">
<D:write abstract=true description="Write any database row">
<ORA:insert abstract=false description="Insert a row"/>
<ORA:update abstract=false description="Update a row"/>
<ORA:delete abstract=false description="Delete a row"/>
</D:write>
<D:read abstract=false description="SELECT data from a compound
principal row"/>
<D:readacl abstract=false description="Read the ACL"/>
<D:acadmin abstract=false description="Update the ACL and
owner"/>
</D:all>
</D:response>
It is envisioned that a right granted or denied to a member of WebDAV ACL-aware administrative client
would list the compound
principal, available in a dialog box, and allow the reference user to the member of the compound principal
MUST override.
Note that rule 2 is conceptually identical
choose non-abstract rights to rule 1. apply in an ACE. The concept
represented by rules 1 and 2, stated generally, rights tree
is useful programmatically to map well-known rights (defined by
WebDAV or other standards groups) into rights that a specific
references always overrides a more general reference.
3.1. Examples are supported
by any particular server implementation.
Sedlar, Clemm [Page 5]
3.2 Rights defined by WebDAV
The following examples demonstrate a situation where the specified
conflict resolution rule would rights defined by WebDAV access control MUST be applied.
3.1.1. Rule 1
A resource specifies that principal A is granted present in
the right response to delete the resource. A property RIGHTS-DISCOVERY method, although they may be
abstract (and not usable within an ACE on the resource specifies that principal A
is denied the a particular
implementation).
3.2.1read Right
Name: <dav:read>
Purpose: The read right provides and restricts access to delete
information regarding the property. The conflict is resolved
by rule 1, state of the resource is resource, including the parent
resource's properties. Affected methods include GET and PROPFIND.
The read right does not affect the property is the child.
As such OPTIONS method since it
reflects capabilities rather than state.
3.2.2write Right
Name: <dav:write>
Purpose: The <write> right affects the child's declaration overrides and principal A is denied same methods as
the right Write Lock. Please refer to delete [WEBDAV] section 5.3 for the resource.
Note, list
of affected methods. Note however, that if other properties do not deny principal A a write lock is a
different mechanism than a write access change, although they
affect the
right same methods, they have independent methods to delete set
them then principal A could delete all properties
but the one mentioned above and could PUT an empty body to the
resource. However it could not successfully execute a DELETE on independent error codes.
3.2.3readacl Right
Name: <dav:readacl>
Purpose: The <readacl> right provides and restricts
access to the
resource, as <dav:acl> property of this would have resource, rather than
the effect of deleting <dav:read> right. If a user has the property
along with <readacl> right and not
the resource.
3.1.2. Rule 2
A resource specifies that principal A is denied <read> right, the read right. The
same resource also specifies that principal B <dav:acl> property ONLY is granted accessible via
PROPFIND, and the read
right. Principal A, however, is a compound principal of which
Principal B GET method is not authorized. If a member. Rule 1 does user has
the <read> right and not apply because the rights <readacl> right, the <dav:acl>
property will not be included in
question are defined any PROPFIND requests on the same
associated resource.
3.2.4writeacl Right
Name: <dav:writeacl>
Purpose: The conflict <writeacl> (Access Control ADMINistration)
right provides and restricts access to ACL method, which is resolved
by rule 2 as the conflict is between a compound principal and one
only means of
its members. In that case principal B has the right to read altering the
resource.
4. ACL Inheritance
When <dav:acl> (and indirectly,
<dav:rights>) property of a new resource is created it may inherit its ACL from its
containing resource.
3.2.5all Right
Name: <dav:all>
Sedlar, Clemm [Page 6]
Purpose: The <dav:all> right controls all other rights on
this resource. If no inheritance method is specified then the
resource has no ACL. Note, however, that the owner value is
automatically set when a resource <dav:all> right appears in an ACE, it is created, so even without
inheritance, there will always be
an owner.
An inherited ACL MUST be applied error to the resource before it have any other right in that ACE. This right is
available
merely shorthand for manipulation. Thus, if inheritance is used, all of the
resource will never be rights enumerated in a state where it does the RIGHTS-
DISCOVERY method, and should not have control access to rights not
exposed via that route.
4 ACCESS CONTROL PROPERTIES
This specification defines a number of new properties for WebDAV
resources. Access control protection.
Inheritance can either properties may be static or dynamic.
Static inheritance means that retrieved just like
other WebDAV properties, using the ACL specified by PROPFIND method. An HTTP
resource on a WebDAV ACL-compliant server MUST contain the parent will
be used to define the ACL for the child. Any subsequent changes made
to the parent will not cause the child's ACL to be altered.
Dynamic inheritance means that the ACL specified by the parent is
used to define the ACL for
following properties:
@ <dav:owner>: A property containing the child but any changes on principal
information identifying a particular user as
the parent's
ACL MUST automatically be made to any inheriting children. The child
is still allowed to define its own ACL values that MUST override any
conflicting inherited ACL.
5. Properties and ACLs
Properties MAY have their own ACL independent owner of the associated resource. By default a property's ACL MUST be dynamically inherited
from This property is
readable by anyone with read access to the associated resource. Note that properties can only inherit
from their associated
resource.
It There is legal no provision for a client
updating this property to carry a setting for what sort of
inheritance its children will have. Currently in this value has no
meaning as properties can not have children, but spec, however
it is expected in
the future recommended that hierarchical properties will any authenticated user
with appropriate administrative privileges be adopted, so
allowed to issue a PROPPATCH to update its
value. Normally, an attempt to PROPPATCH this
setting
property will then have meaning. For now compliant resources MUST
record this value but do not have to do anything with it.
For purposes result in a 401 (Not
Authorized) error. [REQUIRED]
@ <dav:owner-name>: A "live" property containing a human-
readable description of applying scoping conflict resolution rules the
resource is <dav:owner>
[OPTIONAL]
@ <dav:rights>: A "live" property containing the parent and list of
rights of the currently authenticated HTTP
user. Read access to this property is
controlled by the child.
Compliant resources <read> right. This
property can NEVER be set directly.
[REQUIRED]
@ <dav:acl>: A "live" property containing one or more
<dav:ace> tags, which specify which
principals are not required to support setting ACLs
directly on properties.
6. Rights Definitions
The following define a variety of rights. A compliant get access to what rights,
for the resource MUST
support all with this ACL property.
[REQUIRED]
The <dav:acl> element (property) contains 0 or more of the
following XML elements:
@ <dav:ace>: An access control entry, which specifies the
set of rights contained herein.
6.1. all Right
Name: all
Namespace: http://www.ietf.org/standards/acl/
Purpose: The all right provides all rights.
Values: None
Description: In to be granted to a conflict between the "all" right and other
rights, the "all" right is considered a parent and the other rights
a "child." Thus one ACE could provide the ALL right for a particular
principal but another ACE in the same ACL could deny the same
principal a particular right. The conflict would be resolved by
denying the specified principal the more specific right.
6.2. read Right
Name: read
Namespace: http://www.ietf.org/standards/acl/
Purpose: The read right provides and restricts access to
information regarding the state of the resource, including the
resource's properties. Effected methods are GET, INDEX, and
PROPFIND. OPTIONS is not covered by a Read ACL as it reflects
capabilities rather than state.
Values: None
6.3. write Right
Name: write
Namespace: http://www.ietf.org/standards/acl/
Purpose: The Write right affects the same methods as the
Write Lock. Please refer to [WEBDAV] section 5.3 for the list of
affected methods. Note however, that a write lock is a different
mechanism than a write access change, although they affect the same
methods, they have independent methods to set them and independent
error codes.
Values: None
6.4. delete Right
Name: delete
Namespace: http://www.ietf.org/standards/acl/
Purpose: The delete right controls access to the DELETE
method. This method does not affect the ability to remove
properties.
Values: None
6.5. createchild Right
Name: createchild
Namespace: http://www.ietf.org/standards/acl/
Purpose: This right controls the ability to PUT internal
members of a collection and ADDREF external members of a collection.
This ACL has no affect if set on non-collections.
Values: None
6.6. deletechild Right
Name: deletechild
Namespace: http://www.ietf.org/standards/acl/
Purpose: The deletechild right controls the ability to the
DELETE internal members of a collection and DELREF external members
of a collection. This ACL has no affect if set on non-collections.
Values: None
6.7. writeowner Right
Name: writeowner
Namespace: http://www.ietf.org/standards/acl/
Purpose: The writeowner right controls the ability to change
the value of the owner right.
Values: None
6.8. readacl Right
Name: readacl
Namespace: http://www.ietf.org/standards/acl/
Purpose: The readacl right controls the ability to read the
ACL property.
Values: None
6.9. writeacl Right
Name: writeacl
Namespace: http://www.ietf.org/standards/acl/
Purpose: The writeacl right controls the ability to alter
the ACL property.
Values: None
7. Default Principal Types
The following two XML elements are defined principal types.
7.1. allprincipals XML Element
Name: allprincipals
Namespace: http://www.ietf.org/standards/acl/
Purpose: The allprincipals XML element represents all
principals. It is used to specify rights belonging to all
principals, regardless of authentication.
Values: None
7.2. allauthprincipals XML Element
Name: allauthprincipals
Namespace: http://www.ietf.org/standards/acl/
Purpose: The allauthprincipals XML element represents all
authenticated principals. It is used to specify rights belonging to
all authenticated principals.
Values: None
8. ACL Method
The ACL Method serves two distinct purposes. Its request body is
used to define alterations to the ACL of the resource and its
properties. The response contains the ACL for the associated
resource and its properties.
The Request-URI of the ACL method identifies the resource whose ACL
information is to be retrieved and possibly altered.
Change requests through the ACL method MUST be atomic, additionally
changes are all or nothing. If any part of the change request fails
then all changes MUST fail.
8.1. Request
The request may contain up to four XML elements, owner,
aclinheritance, and ACL. The presence of an element, except as
otherwise specified, in the request body causes the associated value
to change.
The presence of an empty ACL causes all ACEs in the ACL, including
ACEs for associated properties, to be deleted.
If an ACE is specified in a request it completely replaces the ACE
currently use for the same principal, if it exists. If an ACE is
submitted with empty grant and deny lists then single
principal.
The <dav:ace> element contains the ACE is deleted.
It is a syntax error for two ACEs following XML elements:
Sedlar, Clemm [Page 7]
@ <dav:grant>: Contains the set of XML elements
corresponding to reference the same principal.
Additionally, although an ACE can be submitted which references
multiple principals, rights being granted via
this is primarily a convenience feature.
Strictly speaking, what the user has done is specify an ACE for
every principal specified. The same logic applies to results that
aggregate principals into a single ACE.
It is illegal to delete any value, ACE, owner, aclinheritance, etc.
with a redundant value. For example, if Must contain at least one ACE grants all
principals read rights and another ACE grants a single principal
read rights, both ACEs MUST be maintained. The reason being that in
the future all principals may have their read rights removed but the
single principal will retain the read right because
@ <dav:deny>: Contains the more
specific ACE will override set of XML elements
corresponding to the more general rights being denied via
this ACE. Additionally Must contain at least one right,
if present.
@ <dav:principal-id>: A URL of the
currently inherited principal resource this ACE
applies to, or one of the tags <dav:owner> or
<dav:all-principals>. Always present. The
value of owner is "someuser" and this element must be unique within
an ACL.
@ <dav:principal>: Contains properties of the principal
explicitly requests that the owner by set
resource (made available here to "someuser", avoid the
information MUST be recorded
need for a separate PROPFIND request).
Optional.
A PROPFIND on the resource. That way if owner a resource on
the source a WebDAV ACL is changed, the proper value as requested by the
client will remain on server might produce the inheriting ACL.
An empty request body will cause
following XML output:
4.1 Example 1 - Retrieving Access Control information
Request
PROPFIND /top/container HTTP/1.1
Host: www.foo.bar
Content-type: text/xml; charset="utf-8"
Content-Length: 0
Depth: 0
<?xml version="1.0">
<D:propfind xmlns:D="DAV:">
<D:allprop/>
</D:propfind>
Response
HTTP/1.1 200 Success
Content-Type: text/xml
Content-Length: xxxxx
<?xml version="1.0" encoding="utf-8" ?>
<?namespace href = "http://www.ietf.org/standards/webdav/ AS =
D"?>
<D:response>
<D:propstat>
<D:creationdate>1997-12-01T17:42:21-08:00</D:creationdate>
<D:displayname>Example collection</D:displayname>
<D:resourcetype><D:collection/></D:resourcetype>
<D:supportedlock> XXXXX</D:supportedlock>
<D:owner>http://www.rational.com/principals/users/gclemm</d:owner
>
<D:owner-name>Geoffrey Clemm</d:owner-name>
Sedlar, Clemm [Page 8]
<D:rights>
<D:read/><D:readacl/>
</D:rights>
<D:acl>
<D:ace>
<D:grant><D:read/><D:write/><D:readacl/></D:grant>
<D:principal-id>
<D:href>http://www.foo.com/users/esedlar</D:href>
</D:principal-id>
<D:principal>
<D:principal-type>User</D:principal-type>
<D:principalname>esedlar</D:principalname>
<D:displayname>Eric Sedlar</D:displayname>
</D:principal>
</D:ace>
<D:ace>
<D:grant><D:read/><D:readacl/></D:grant>
<D:deny><D:writeacl/></D:deny>
<D:principal-id>
<D:href>http://www.foo.com/groups/marketing</d:href>
</D:principal-id>
<D:principal>
<D:principal-type>Group</D:principal-type>
<D:displayname>Foo.Com marketing
department</D:displayname>
<D:principalname>mktdept</D:principalname>
</D:principal>
</D:ace>
<D:ace>
<D:grant><D:read/></D:grant>
<D:principal-id><d:all/></D:principal-id>
</D:ace>
</D:acl>
<D:propstat>
<D:response>
5 USING ACLS
By default, a principal has no change access rights to the ACL or associated
values.
8.2. Response
If the request body was empty an object
protected by an ACL. A particular ACE may either grant or if the changes were successful deny a
200 Success response MUST be returned with
set of rights to a response body
containing single principal. It is illegal for an ACL to
have two ACEs applying to the owner, aclinheritance, and same principal. However, since a
server may match the acl XML elements with
values for all properties.
[Ed Note - I am not dealing currently authenticated HTTP user with error conditions yet as the error
reporting format
multiple principals, it is going possible for multiple ACEs to have apply to be pretty complex and I want
the current user. In this case, if a particular right is denied
to
get buy off on the ACL model and current user by any ACE, this supercedes any ACE that
might grant that right. This is the request format before I write
up case regardless if a couple of pages on how ("more
specific") ACE granting access applied to do errors for a principal identifying
the user directly, while the ACE denying access applied to a
collection principal containing that format.]
8.3. acl XML element
Name: acl
Namespace: http://www.ietf.org/standards/acl/
Purpose: Defines an ACL.
Parent: Any
Values= (inheritance [owner] [aclinheritance] *ACE
*property)
Description: An empty ACL element will delete all ACEs contained
in an ACL, including user. The particular order
of the ACEs of any properties. Note, however, that
there MUST always be within an ACL value defined on a resource, even if it is empty.
8.4. owner XML Element
Name: owner
Namespace: http://www.ietf.org/standards/acl/
Purpose: Specifies irrelevant. The <principal-id> tag
can also contain the owner of following special tags: <owner>, <all>,
<unauthenticated>. These tags have the resource.
Parent= acl
Values= Principal
Description: following meaning:
Sedlar, Clemm [Page 9]
@ owner: The owner XML element specifies the principal who
owns identified by the resource. The default value for owner MUST be the principal
who created property on
this resource is granted or denied the resource. rights specified in
this ACE.
@ all: The owner current user always retains matches this ACE, whether or
not s/he is authenticated.
@ unauthenticated: The current user matches this ACE if not
authenticated
Server implementations may limit the right number of ACEs in an ACL.
However, ACL-compliant servers are required to support at least
one ACE granting rights to a single principal, and one ACE
granting rights to a collection principal. The server should
return an error "Too many ACEs" in this case.
6 ACL METHOD
The ACL Method provides a mechanism to
alter the ACL. So, for example, an owner who was not granted the
right set ACL information. Its
request body is used to define alterations to read the resource could not read ACL of the resource. However
resource identified by the
owner could alter request-URI. Its response body
contains the current ACL so as to grant for that resource. The ACL method
replaces the read right to
themselves. A principal MUST have <acl> and <owner> properties on the writeowner right to change specified
resource with the
owner property's value. An empty Owner element submitted in a
request will not cause a change properties in the Onwer value. Owner MUST
always have a value. request. All compliant resources MUST support the owner
value.
8.5. aclinheritance XML Element
Name: aclinheritance
Namespace: http://www.ietf.org/standards/acl/
Parent= acl
Purpose: The aclinheritance XML element identifies readable ACEs
previously stored in the type
of inheritance to be used with children of ACL on the associated resource.
The AclInheritance value MUST default to Dynamic. An empty
AclInheritance submitted in indicated resource are
removed, so an ACL method on a request resource with an unreadable <acl>
property will not cause a change in be ignored. (If the
AclInheritance value. This element has no meaning on non-
collections. However, collections MUST provide this property.
Values= ("Dynamic" | "Static" | "None" | Extension)
;Extension is defined, somewhere server implements rights
outside of those defined in DAV. URL is defined, someplace,
somewhere.
Description: Although this element has no meaning when defined
on a property, resources MUST record its value.
8.6. inheritance XML Element
Name: inheritance
Namespace: http://www.ietf.org/standards/acl/
Purpose: Defines the inheritance used for a particular ACL.
Parent: acl
Values= ("Dynamic" | "None" | Extension)
Description: Specifies if the ACL is inheriting its value
dynamically or not at all. Static is not an option since static
inheritance can specification, they might allow
only some ACEs to be visibleùin this case, only occur when part of the ACL was created and so was
controlled by
will be replaced).
Change requests through the ACL source.
8.7. principal XML Element
Name: principal
Namespace: http://www.ietf.org/standards/acl/
Purpose: To identify a principal.
Parent: any
Values= *cdata
8.8. ace XML Element
Name: ace
Namespace: http://www.ietf.org/standards/acl/
Purpose: Contains access right information associated with
one or more principals.
Parent: acl
Values= Principal Allow Deny
Description: A principal method MUST NOT be directly referred to in
more than one ACE on a resource. That is, each principal has a
particular ACE which specifies atomic. If any
part of the change request fails then all changes MUST fail. The
presence of its directly granted rights.
Thus specifying two an empty ACL causes all ACEs which directly reference the same principal in a request is a syntax error.
8.9. grant XML Element
Name: grant
Namespace: http://www.ietf.org/standards/acl/
Purpose: Identifies the rights the ACL, including
ACEs for associated principals are
granted.
Parent: ACE
Values: Right Identifiers
8.10. deny XML Element
Name: deny
Namespace: http://www.ietf.org/standards/acl/
Purpose: Identifies the rights properties, to be deleted. An empty request
body will cause no change to the associated principals are
denied.
Parent: ACE
Values: Right Identifiers
8.11. property XML Element
Name: property
Namespace: http://www.ietf.org/standards/acl/
Purpose: Provides ACL for properties.
Parent: ACL
Values= Prop ACL
Description: The properties in or associated values. If
the Prop XML <principal> element MUST be
empty.
9. Examples
9.1. (specifying properties of the resource
identified by the ACE's <principal-id>) is specified, it (and its
children) is ignored.
6.1 Example 1 - Retrieving Setting ACLs
An ACL information request body is an acl-info XML element. The <dav:acl-
info> element contains properties that can be set by the ACL
method (currently just <acl>).
Request
ACL /top/container/ /top/container HTTP/1.1
Host: www.foo.bar
Content-Length: xxxx
Content-Type: text/xml
HTTP/1.1 200 Success www.foo.com
Content-Type: text/xml
Content-Length: xxxxx
<?namespace href = "http://www.ietf.org/standards/acl/" AS = "a"?> xxxx
<?namespace href = "http://www.ietf.org/standards/dav/" "http://www.ietf.org/standards/webdav/ AS = "d"?>
<a:acl>
<a:inheritance>dynamic</a:inheritance>
<a:owner>someonesomewhere</a:owner>
<a:ace>
<a:principal>domain/joebob</a:principal>
<a:grant/>
<a:deny><a:all/></a:deny>
</a:ace>
<a:property>
<d:prop><d:creationdate></d:prop>
<a:acl>
<a:inheritance>dynamic</a:inheritance>
<a:owner>blah</a:owner>
<a:ace>
<a:principal>domain/joebob</a:principal>
<a:grant/><a:all/></a:grant>
<a:deny/>
</a:ace>
</a:acl>
</a:property>
<a:property>
<d:prop>
<d:displayname><d:get-content-language><d:get-content-
length><d:get-content-type><d:get-etag><d:get-
lastmodified><d:index-content-language><d:index-content-
length><d:index-etag><d:index-last-modified><d:resourcetype>
</d:prop>
<a:acl>
<a:inheritance>dynamic</a:inheritance>
</a:acl>
</a:property>
</a:acl>
The
D"?>
<D:acl-info>
Sedlar, Clemm [Page 10]
<D:acl>
<D:ace>
<D:grant><D:read/><D:write/><D:readacl/></D:grant>
<D:principal-id>
<D:href>http://www.foo.com/users/esedlar</D:href>
</D:principal-id>
</D:ace>
<D:ace>
<D:grant><D:read/> </D:grant>
<D:principal-id>
<D:href>http://www.foo.com/groups/marketing</D:href>
</D:principal-id>
</D:ace>
</D:acl>
</D:acl-info>
Response
HTTP/1.1 200 Success
Content-Length: 0
This request was empty so no changes will the group ACE to disallow read access to the
ACL for the marketing group. The other information had to be made, rather
recopied from the
response ACL retrieved in the previous example.
7 ACL INHERITANCE / DEFAULT ACLS
To be added
Sedlar, Clemm [Page 11]
8 XML SCHEMA FOR DEFINED ELEMENTS
<?xml version='1.0'?>
<!-- XML Schema for WebDAV ACLs -->
<!DOCTYPE schema PUBLIC "-//IETF//DTD WEBDAVACL 20000420//EN"
"WebDAVACL.dtd" >
<schema xmlns="http://www.w3.org/1999/XMLSchema"
targetNamespace="http://www.ietf.org/standards/webdav"
xmlns:dav="http://www.ietf.org/standards/webdav"
blockDefault="#all" elementFormDefault="qualified">
<element name="right" abstract="true">
<complexType content="empty">
</element>
<!--For those folks not familiar with XML Schema, minOccurs
defaults to 0, and maxOccurs defaults to 1 -->
<element name="dav:read" base="right" equivClass="right"/>
<element name="dav:write" base="right" equivClass="right"/>
<element name="dav:readacl" base="right" equivClass="right"/>
<element name="dav:writeacl" base="right"
equivClass="right"/>
<element name="dav:all" base="right" equivClass="right"/>
<complexType name="dav:rights-list">
<choice minOccurs="1" maxOccurs="unbounded">
<element ref="dav:right">
<element name="dav:unauthenticated" content="empty"/>
<element name="dav:all" content="empty"/>
<element name="dav:owner" content="empty"/>
</complexType>
<complexType name="dav:ace">
<element name="dav:grant" type="dav:rights-list"
minOccurs="0" maxOccurs="1">
<element name="dav:deny" type="dav:rights-list"
minOccurs="0" maxOccurs="1">
<element name="dav:principal-id" minOccurs="1"/>
<complexType>
<choice minOccurs="1">
<element name="dav:owner" content="empty"/>
<element name="dav:all" content="empty"/>
<element name="dav:unauthenticated" content="empty"/>
<element name="dav:href" type="uri"/>
</choice>
</complexType>
</element>
<element name="dav:principal" minOccurs="0" maxOccurs="1">
<complexType>
<element name="dav:principal-name" type="string"
minOccurs="1"/>
Sedlar, Clemm [Page 12]
<element name="dav:principal-type" type="string"
minOccurs="1"/>
</complexType>
</element>
</complexType>
<element name="dav:acl">
<complexType>
<element name="dav:ace" type="dav:ace"
minOccurs="0" maxOccurs="unbounded"/>
</complexType>
</element>
<element name="dav:rights">
<complexType>
<choice minOccurs="1" maxOccurs="unbounded">
<element ref="dav:right"/>
</choice>
</complexType>
</element>
</schema>
9 INTERNATIONALIZATION CONSIDERATIONS
To be supplied.
10 SECURITY CONSIDERATIONS
To be supplied.
11 SCALABILITY
To be supplied.
12 AUTHENTICATION
Authentication mechanisms defined in WebDAV will just contain all also apply to
WebDAV ACL.
13 IANA CONSIDERATIONS
This document uses the relevant values. namespace defined by [RFC2518] for XML
elements. All other IANA considerations mentioned in [RFC2518]
also applicable to WebDAV ACL.
14 INTELLECTUAL PROPERTY
The resource
gets its own ACL dynamically following notice is copied from its parent, top. However this
resource does override RFC 2026, section 10.4, and
describes the inherited ACL. Specifically, it defines
its owner, someonesomewhere, rather than inheriting it. However, position of the IETF concerning intellectual
property claims made against this document.
Sedlar, Clemm [Page 13]
The IETF takes no position regarding the
absence validity or scope of an aclinheritance element indicates any
intellectual property or other rights that might be claimed to
pertain to the resource
inherits that value. Additional implementation or use other technology described
in this document or the principal domain/joebob is
denied all 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. So regardless of what
Information on the IETF's procedures with respect to rights domain/joebob may
have been granted in top's ACL, all those rights are denied
standards-track and standards-related documentation can be found
in
relation to top/container. While the ACL BCP-11. Copies of claims of rights made available for creationdate is also
inherited it has its own owner, blah,
publication and has any assurances of licenses to be made available,
or the result of an additional ACE attempt made to obtain a general license or
permission for
joebob. All the rest use of the properties have their ACLs inherited such proprietary rights by implementers
or users of this specification can be obtained from the resource. Therefore the denial of all IETF
Secretariat.
The IETF invites any interested party to bring to its attention
any copyrights, patents or patent applications, or other
proprietary rights that may cover technology that may be required
to
domain/joebob would also apply practice this standard. Please address the information to the resource's properties but
creationdate..
9.2. Example 2 - Setting ACLs
ACL /top/container.html HTTP/1.1
Host: www.foo.com
Content-Type: text/xml
Content-Length: xxxx
<?namespace href = "http://www.ietf.org/standards/dav/" AS = "D"?>
<?namespace href = "http://www.ietf.org/standards/acl/ AS = "A"?>
<a:acl>
<a:property>
<a:aclinheritance>none</a:aclinheritance>
<d:prop>
<d:creationdate/>
</d:prop>
<a:acl>
<a:ace>
<a:principal>domain/joebob</a:principal>
<a:grant/><a:deny/>
</a:ace>
</a:acl>
</a:property>
</a:acl>
HTTP/1.1 200 Success
Content-Type: text/xml
Content-Length: xxxxx
<?namespace href = "http://www.ietf.org/standards/acl/" AS = "a"?>
<?namespace href = "http://www.ietf.org/standards/dav/" AS = "d"?>
<a:acl>
<a:inheritance>dynamic</a:inheritance>
<a:owner>someonesomewhere</a:owner>
<a:aclinheritance>none</a:aclinheritance>
<a:ace>
<a:principal>domain/joebob</a:principal>
<a:grant/>
<a:deny><a:all/></a:deny>
</a:ace>
<a:property>
<d:prop><d:creationdate></d:prop>
<a:acl>
<a:inheritance>dynamic</a:inheritance>
<a:owner>blah</a:owner>
</a:acl>
</a:property>
<a:property>
<d:prop>
<d:displayname><d:get-content-language><d:get-content-
length><d:get-content-type><d:get-etag><d:get-
lastmodified><d:index-content-language><d:index-content-
length><d:index-etag><d:index-last-modified><d:resourcetype>
</d:prop>
<a:acl>
<a:inheritance>dynamic</a:inheritance>
</a:acl>
</a:property>
</a:acl>
IETF Executive Director.
15 ACKNOWLEDGEMENTS
This example assumes the state left from example 1. In the request protocol is the user asks that collaborative product of the aclinheritance value be set WebDAV ACL
design team: xxx, yyy, zzz. We would like to none and that
the ACE on acknowledge the property creationdate
foundation laid for us by the principal domain/joebob
be removed. Even if authors of the inherited aclinheritance value WebDAV and HTTP
protocols upon which this protocol is none, the
resource MUST still record the redundant value as layered, and the value on invaluable
feedback from the
source ACL may change.
10. Authors' Addresses
Paul J. Leach
Yaron Y. Goland
Microsoft
1 Microsoft Way
Redmond, WA 98052
Phone: (425)936-4765
Email: {paulle, yarong}@microsoft.com
11. Bibliography WebDAV working group.
16 INDEX
To be supplied.
17 REFERENCES
[RFC2026] S.Bradner, "The Internet Standards Process", Harvard,
1996, <http://www.ietf.org/rfc/rfc2026.txt>.
[RFC2068] R. Fielding, J. Gettys, J. Mogul, H. Frystyk, T. Berners-
Lee, 'Hypertext R.Fielding, J.Gettys, J.C.Mogul, H.Frystyk, and
T.Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1', HTTP/1.1", RFC
2068, January U.C. Irvine, DEC, MIT/LCS, 1997,
<http://www.ietf.org/rfc/rfc2068.txt >.
[RFC2119] S.Bradner, "Key words for use in RFCs to Indicate
Requirement Levels", Harvard, 1997, <URL:ftp://ds.internic.net/rfc/rfc2068.txt>
[WebDAV]
<http://www.ietf.org/rfc/rfc2119.txt >.
[RFC2518] Y. Goland, E. J. Whitehead, Jr., Asad Faizi, Stephen R.
Carter, Del Jensen 'Extensions E.Whitehead, A.Faizi, S.R.Carter, D.Jensen,
"HTTP Extensions for Distributed Authoring and
Versioning on the World Wide Web -- WEBDAV', October 1997, WORK
IN PROGRESS, <URL:ftp://ftp.ietf.org/internet-drafts/draft-ietf-
webdav-protocol-04.txt>
[XML] W3C, 'Extensible Markup Language - Part1. Syntax', March 1997
<URL:http://www.w3.org/pub/WWW/TR/WD-xml-lang.html> WEBDAV", Microsoft,
U.C.Irvine, Netscape, Novell, 1999
<http://www.ietf.org/rfc/rfc2518.txt>.
Sedlar, Clemm [Page 14]
18 AUTHORS' ADDRESSES
Eric Sedlar
Oracle Corporation
500 Oracle Parkway
Redwood Shores, CA 94065
Email: esedlar@us.oracle.com
Geoffrey Clemm
Rational Software
20 Maguire Road
Lexington, MA
Email: geoffrey.clemm@rational.com
19 STILL TO DO :
@ Describe the interactions with resource locking. I'm not
clear what the resolution was as far as locking the ACL
separately from locking the resource.