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Re: [ietf-dkim] Modified Introduction text forrfc4871-errata (resend)

2009-06-17 13:17:52
API Definition? The socket example? Come on.

BTW, What is the definition of an Application Programming Interface 
and what portion of DKIM is like an API definition.

This is incomprehensible, overdone to get some simple concept across 
that only needs 1 or 2 paragraphs.  Dave, these paragraphs is really 
obscure. You can do better and get this API angle out.

If you going to this level, you need to be more specific with software 
engineering terminologies and how it applies to SMTP.  Murray's API is 
not going to be same as MY API or that guys API and it may not be just 
in C or C++, but in multiple of languages, and the API be COM 
interface, a .NET interface,  including a JAVA interface.  It may come 
in the form of shims, hooks, callouts, triggers, events or what have 
you.

If the functional model is attempted be described, a simple paragraph 
that ALL developers with SMTP knowledge will understand might be:

   DKIM Verification and Assessors Processing can be done during
   the SMTP session or post acceptance level.  In order to provide
   assessors the available data it might need, the DKIM
   verification result, the RFC 5321 envelope fields and RFC 5322
   payload SHOULD be made available for internal and external
   Assessor processing.

   At a minimum, the DKIM verification result and the DKIM-Signature
   signing domain identity (D=) value MUST be made available to
   assessors.

   How the information is provided to Assessors is implementation
   dependent and not in scope of this document.

Simple? Huh?

---

Dave CROCKER wrote:


MH Michael Hammer (5304) wrote:
+1

From: ietf-dkim-bounces(_at_)mipassoc(_dot_)org [mailto:ietf-dkim-


Hmmm.  Noting two quick +1s to Murray's text and in the interest of still 
trying 
to bring this "quick" errata/update effort to a close, I'm inclined to 
suggest 
adding his explanatory text to the existing proposed addition.

While it's entirely plausible that Murray can formulate a superior version of 
the basic text for the addition, I think that the existing +1s for the 
existing 
text and the +1s for Murray's commentary offers us something quicker.

So, here's a suggested merging of the two:

       <t>This currently leaves signers and assessors with the potential for
         making different interpretations between the two identifiers and may
         lead to interoperability problems. A signer could intend one to be
         used for assessment, and have a non-reputation intent in setting the
         value in the other. However the verifier might choose the wrong value
         to deliver to the assessor, thereby producing an unintended (and
         inaccurate) assessment.</t>

       <t>This update resolves that confusion.  It defines additional, 
semantic
         labels for the two values, clarifies their nature and specifies their
         relationship.  More specifically, it clarifies that the identifier
         intended for delivery to the assessor -- such as one that consults a
         white list -- is the value of the "d=" tag. However, this does not
         prohibit message filtering engines from using the "i=" tag, or any
         other information in the message's header, for filtering decisions.
       </t>

       <t>For signers and verifiers that have been using the i= tag as the
         primary value that is delivered to the assessor, a software change to
         using the d= tag is intended.
       </t>

      <t>So, this Update clarifies the formal interface to DKIM, after
        signature verification has been performed. It distinguishes DKIM's
        internal signing and
        verification activity, from its standardized delivery of data to that
        interface.</t>

       <t>The focus of the Update is on the portion of DKIM that is much like
         an API definition.  If DKIM is implemented as a software library for
         use by others, it needs to define what outputs are provided, that is,
         what data that an application developer who uses the library can 
expect
         to obtain as a result of invoking DKIM on a message.</t>

       <t>This Update draft defines the output of that library to include the
         yes/no result of the verification and the "d=" value.  In other 
words,
         it says what (one) identifier was formally specified for use by the
         signer and whether the use of that identifier has been validated. For
         a particular library, other information can be provided at the
         discretion of the library developer, since developers of assessors --
         these are the consumers of the DKIM library -- well might want more
         information than the standardized two pieces of information. However
         that standardized set is the minimum that is required to be provided
         to a consuming module, in order to be able to claim that the library
         is DKIM compliant.</t>

       <t>This does not state what the implicit value of "i=" is, relative to
        "d=".  In this context, that fact is irrelevant.</t>

       <t>Another example is the difference between the socket interface to 
TCP
         versus the TCP protocol itself.  There is the activity within the
         protocol
         stack, and then there is the activity within in the software 
libraries
         that are actually used.</t>


Comments? (And yes, quick +1s are eagerly sought.)

d/


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