2.1.11 WWW Distributed Authoring and Versioning (webdav)

Last Modified: 2003-06-16

Chair(s):
Jim Whitehead <ejw@cse.ucsc.edu>
Lisa Dusseault <lisa@xythos.com>
Applications Area Director(s):
Ned Freed <ned.freed@mrochek.com>
Ted Hardie <hardie@qualcomm.com>
Applications Area Advisor:
Ted Hardie <hardie@qualcomm.com>
Mailing Lists:
General Discussion: w3c-dist-auth@w3.org
To Subscribe: w3c-dist-auth-request@w3.org
In Body: Subject of subscribe
Archive: http://www.w3.org/pub/WWW/Archives/Public/w3c-dist-auth/
Description of Working Group:
The goal of this working group is to define extensions to the Hypertext
Transfer Protocol (HTTP) that enable remote collaborative authoring of
Web resources.

When the WebDAV working group was initially formed, it was reacting to
experience from circa-1995/96 HTML authoring tools that showed they
were
unable to meet their user's needs using the facilities of the HTTP
protocol. The observed consequences were either postponed introduction
of distributed authoring capability, or the addition of nonstandard
extensions to the HTTP protocol. These extensions, developed in
isolation, are not interoperable. The WebDAV Distributed Authoring
Protocol, RFC 2518, addressed these concerns by providing facilities
for
overwrite prevention (locking), metadata management (properties), and
namespace management (copy, move, collections).

Despite their utility, several important capabilities were not
supported
in the initial Distributed Authoring Protocol. It is a goal to create
protocols to support these capabilities:

* Referential Containment (Bindings): The WebDAV Distributed Authoring
  Protocol has unusual containment semantics where multiple containment
  is allowed, but not supported by any protocol operations, yet
  container deletion assumes inclusion containment, deleting the
  container and its members. Most object management systems provide
full
  support for referential containment, and have delete semantics that
  only remove the container without affecting contained objects.

* Ordered Collections: Collection contents have a persistently
  maintained ordering.

* Namespace Redirection (Redirect References): HTTP, via its 301 and
  302 responses, supports namespace redirection where a request on one
  URL is returned to the client with instructions to resubmit the same
  request to another URL.

* Access Control: Remote management of access permissions on Web
  resources.

Experience to date with WebDAV properties has suggested that
interoperability of these properties would be improved by the creation
of a voluntary, central registry of WebDAV properties. Procedures for
registering new properties, updating existing property descriptions,
and the contents of each registry item need to be detailed.

As with most application layer protocols, implementation and field
experience on the WebDAV Distributed Authoring Protocol has highlighted
many issues that should be addressed as the protocol is advanced from
proposed to draft standard status. Some of these issues will require
additional deliberation within the WebDAV working group.

NOT IN SCOPE:

The following items were initially identified as being out of scope for
the WebDAV working group, and continue to be such:

* Definition of core attribute sets, beyond those attributes necessary
  for the implementation of distributed authoring and versioning
  functionality

* Creation of new authentication schemes

* HTTP server to server communication protocols

* Distributed authoring via protocols other than HTTP and SMTP

* Implementation of functionality by non-origin proxies

The WebDAV working group initially had a goal of supporting remote
versioning operations as well. However, when this scope was found to be
too broad, the DeltaV working group was formed. As a result,
development
of a versioning protocol is currently not in scope for WebDAV, though
discussions related to compatibility between versioning and remote
authoring are still in scope.

Deliverables

The final output of this working group is expected to be these
documents:

1. A Bindings Protocol, providing a specification of operations 
  supporting referential containment for WebDAV collections. [Proposed
  Standard]

2. An Ordered Collections Protocol, providing a specification of
  operations for manipulating and listing persistent orderings for
  WebDAV collections.[Proposed Standard]

3. A Redirect References Protocol, providing a specification of
  operations for remote maintenance of namespace redirections, and the
  interaction of these redirections with existing HTTP and WebDAV
  methods. [Proposed Standard]

4. An Access Control Goals document, providing a list of goals the
  access control protocol should meet, and not meet. [Informational]

5. An Access Control Protocol, providing extensions to WebDAV that
  allow remote control over the access rights for Web resources.
  [Proposed Standard]

6. A Property Registry, describing a process for registering WebDAV
  properties, and the contents of each registry item. [Informational]

7. An updated version of WebDAV Distributed Authoring Protocol that
  resolves known issues with the protocol. [Draft Standard]

At present, the Binding Protocol and Redirect Reference protocol have
both been through a working group last call for comments process, and
are very close to completion. The Ordered Colletions protocol has also
had significant review, and is also close to completion. The access
control, and property registry documents are new work, as is the
revision of the WebDAV Distributed Authoring Protocol.

In addition to the IETF Internet-Draft repository
(http://www.ietf.org/ID.html), the most recent versions of these
documents are accessible via links from the WebDAV Home Page,
(http://www.ics.uci.edu/pub/ietf/webdav/), and on WebDAV Resources,
(http://www.webdav.org/).
Goals and Milestones:
Done  Revise Access Control Protocol document. Submit as Internet-Draft.
Done  Meet at Pittsburgh IETF. Discuss Access Control Goals and Protocol documents. Discuss issues in WebDAV Distributed Authoring Protocol
Done  Revise Access Control Protocol document. Submit as Internet Draft.
Oct 00  Revise Binding Protocol document, submit as Internet-Draft. Begin working group last call for comments.
Done  Revise Access Control Protocol, and Access Control Goals documents. Submit as Internet Draft. Begin working group last call for comments.
Done  Revise WebDAV Distributed Authoring Protocol. Submit as Internet-Draft
Dec 00  Revise Redirect References Protocol. Begin working group last call for comments.
Done  Meet at San Diego IETF. Hold a review of the Access Control Goals and Protocol documents. Discuss comments raised during working group last call for comments. Discuss issues in WebDAV Distributed Authoring Protocol.
Jan 01  Revise Access Control Protocol and Goals documents. Submit as Internet Draft. Submit Access Control Protocol to IESG for approval as Proposed Standard. Submit Access Control Goals to IESG for approval as Informational RFC.
Feb 01  Submit revised Redirect References protocol as Internet-Draft. Submit to IESG for approval as Proposed Standard.
Done  Submit revised Ordered Collections protocol as Internet-Draft. Begin working group last call for comments.
Mar 01  Submit initial WebDAV properties registry document as Internet-Draft
Mar 01  Submit revised Distributed Authoring Protocol as Internet-Draft.
Done  Meet at Minneapolis IETF. Discuss issues in WebDAV Distributed Authoring Protocol, and WebDAV property registry.
Apr 01  Submit revised Ordered Collections protocol as Internet-Draft. Submit to IESG for approval as a Proposed Standard.
May 01  Submit revised WebDAV properties registry document as Internet-Draft
Jun 01  Submit revised WebDAV properties registry document as Internet-Draft. Submit to IESG for approval as Informational RFC.
Jun 01  Submit revised Distributed Authoring Protocol as Internet-Draft. Begin working group last call for comments.
Aug 01  Submit revised Distributed Authoring Protocol as Internet-Draft. Submit to IESG for approval as Draft Standard.
Internet-Drafts:
  • - draft-ietf-webdav-acl-10.txt
  • - draft-ietf-webdav-redirectref-protocol-03.txt
  • - draft-ietf-webdav-ordering-protocol-10.txt
  • - draft-ietf-webdav-rfc2518bis-04.txt
  • - draft-ietf-webdav-bind-02.txt
  • - draft-ietf-webdav-quota-01.txt
  • Request For Comments:
    Requirements for a Distributed Authoring and Versioning Protocol for the World Wide Web (RFC 2291) (44036 bytes)
    HTTP Extensions for Distributed Authoring -- WEBDAV (RFC 2518) (202829 bytes)

    Current Meeting Report

    adjurned.WebDAV Working Group
    Vienna IETF
    July 2003
    
    AGENDA
     - Interop plans  5 min
     - Various draft status
     - ACL progress
     - RFC2518bis issues
     - Possible SIP needs
    
    VARIOUS DRAFT STATUS
    
    Ordering
     - Minor nits but approved by IESG
     - Last check on specific changes
    Binding
     - Still requires significant explanation if not changes
    Search
     - Minor progress
    
    ACL PROGRESS
    
    Addressed IESG review issues
    Issue: too many possible semantics
     - Resolution: chose one
    Issue: hard for clients to tell what ACL server will allow
     - Resolution: added acl-semantics info property
    Issue: no clear privilege for DELETE method
     - Resolution: added "unbind" privilege
    Issue: allows insecure "Basic" auth
     - Resolution: "Implementation of the ACL spec requires that Basic 
    authentication, if used, MUST only be supported over secure transport such as 
    TLS."
    Attempt to make mapping between methods and permissions more clear The "who 
    am I" request header, response header contains answer
    
    RFC2518 BIS ISSUES
    
    DTD usage
     - Do we include DTDs at all
     - Do we use content ANY or content a specific list of child elements
     - How do we show/enforce extensibility?
     - How do we show namespace usage (e.g. on attributes)?
     - ELEMENT foo | ns (bar, baz?, ANY)
    207 response to DELETE failures
     - Again"¦
     - Keep or toss
    Stronger requirement for ETag support
     - Still not 

    Slides

    None received.