Re: Why MD5 Headers are Imperative

>
>There are now dozens of messages about this MD5 stuff.  Is there a  
>Pace or another suggestion for specific wording changes in the spec?   
>If not, you're wasting your time.  -Tim
>

I've been hashing out an idea and hoping to get some help with it, I never 
had the intention of first-time-authoring a Pace without any feedback from 
the group first.  Now that I do have some preliminary wording, any assistance 
in turning it into a Pace would be greatly appreciated, but I still worry 
that at this late date, with so much pressure to "just release something", 
it's far too easy to just shoot this down without really considering it.

I would feel so much better if anyone on the WG would even acknowledge that 
I'm not just clamoring for attention, but actually do have a point, and 
discuss the problem.  Then I could re-lurk and get back to my business.

Anyway, here's what I have, I know it needs work but that still isn't the 
point, the point remains that an Atom Publishing Protocol cannot and should 
not ignore the publisher-gets-control aspect of the underlying format by 
trying to make it WebDAV or something:

5.3     Once a resource has been created and the URI of its Atom Entry Document 
(its 
        'Member URI') is known, that URI may be used to update and delete the 
        resource.  The Member URI may also be used to retrieve a readable 
        representation of the resource or, using the Atom Protocol, a writable 
        representation of the resource.

5.3.1   Retrieving  a  Resource 
 
    Client                                      Server 
      |                                            | 
      |   1.)  APP-GET  to  Member  URI                 | 
      |------------------------------------------>| 
      |                                            | 
      |   2.)  Writable Member  Representation        | 
      |<------------------------------------------| 
      |                                            | 
 
    1.   The  client  sends  an APP-GET  request to  the  Member  URI  to  
        retrieve its  writable representation, as follows:

        1a.  The client MUST force revalidation on the server
        1b.  The client MUST send an X-APP-MD5 header with the value "GET"
        1c.  The client MAY send an URL parameter with a specific XML ID:
                http://example.com/resource;id={xml:id}
            This supports the selection of multiple revisions of a Member
            Resource when an @xml:id exists for <link rel='edit'/>
 
    2.   The  server  responds  with  the  writable representation  of  the 
        resource.  An APP-aware server MUST:

        2a.  Send a VARY:X-APP-MD5 header in response to any GET request 
            for the Member URI
        2b.  Send a Content-Md5 header in response to any APP-GET request 
            as per 1b
 
 
5.3.2   Updating  a  Resource 
 
    Client                                      Server 
      |                                            | 
      |   1.)  APP-PUT  to  Member  URI                 | 
      |------------------------------------------>| 
      |                                            | 
      |   2.)  409  Conflict                          | 
      |<------------------------------------------| 
      |                                            | 
      |   3.)  200  OK                                | 
      |<------------------------------------------|  
 
    1.   The client sends an updated representation  to  the  Member's URI 
        utilizing APP-PUT as follows:

        1a.  The client MUST send an X-APP-MD5 header whose content is equal to 
      the value the server returned in the Content-Md5 header

    2.   If the X-APP-MD5 value of the APP-PUT request is not equal to the 
      current Content-Md5 value of the Member URI the server MUST respond 
      with a status code of 409.
 
    3.   Upon  a  successful  update  of  the  resource  the  server  
      responds  with  a  status  code  of  200. 

-EJB

P.S. I would like to thank everyone for their time, who has chosen to give of 
it, throughout the course of the project and as pertains to my concerns.