Fwd: Callout Protocol Core - Kept parameter

Martin Thelian <[email protected]> Tue, 25 Apr 2006 06:39:53 +0200
Newsgroups gmane.ietf.opes
Message-ID <[email protected]> 
Hi,

Is there anyone out there who can answer my question regarding the Kept 
parameter of the opes core protocol "Data Use Mine" message? The 
inconstancy I've pointed out does not only affect this parameter but 
would cause a OCP agent to terminate the transaction because of a 
invalid message format caused by this parameter.

Furthermore I've found another inconstancy in the specification. It is 
in RFC 4236, section 3.9 (examples) where the server sends back the 
following answer:
|>    S: DUM 55 0
|>       AM-Part: response-header
|>
|>       76:HTTP/1.1 403 Forbidden
|>       Content-Type: text/html
|>       Proxy-Connection: close
|>
|>       ;
|>    S: DUM 55 0
|>       AM-Part: response-body
|>
|>       67:<html><body>You are not allowed to
|>       access this page.</body></html>
|>       ;

Please note the my-offset parameter of the DUM messages. It's 0 in both 
messages. This would cause a non http-profile aware agent (e.g. if the 
callout server simply forward the messages to an other agent) to belief 
that a AME message is missing.

Regards,
Martin Thelian

-------- Original-Nachricht --------
Betreff: 	Callout Protocol Core - Kept parameter
Datum: 	Mon, 17 Apr 2006 16:21:46 +0200
Von: 	Martin Thelian <[email protected]>
An: 	[email protected]



Hi,

I am confused about the definition of the Kept parameter of a DUM 
message. The parameter is defined in rfc4037 as follows
|>   DUM: extends message with {
|>           xid my-offset;
|>           [As-is: org-offset];
|>           [Kept: org-offset org-size ];
|>           [Modp: modp];
|>   } and payload;

And in rfc4236 the Kept parameter is e.g. used in the following example:
|>    P: DUM 88 65
|>       Kept: 65 64
|>       AM-Part: response-header
|>
|>       64:HTTP/1.1 200 OK
|>       Content-Type: text/html
|>       Content-Length: 95

I'm confused, because the value of the Kept parameter doesn't follow the 
rules for a valid message format (see: rfc 4037, 3.1). A value can be a 
struct, list or atom. The value shown in the example is not a struct or 
list, so it must be an atom value. But a atom value must not have 
spaces, or the value has to be quoted.

So, what's the correct representation of the Kept parameter value?

As list?
|> Kept: (65,64)

As structure?
|> Kept: {65 64}

Quoted?
|> Kept: "65 64"

Regards,
Martin Thelian