Re: z= question with X headers

----- Original Message -----
From: "Eric Allman" <eric+dkim@xxxxxxxxxxxx>
To: <arvel.hathcock@xxxxxxxx>
Cc: <ietf-dkim@xxxxxxxxxxxx>
Sent: Friday, April 28, 2006 3:34 PM
Subject: Re: [ietf-dkim] z= question with X headers


> > Perhaps:
> >
> > "A vertical-bar-separated list of select header field names and
> > copies of header field values that identify the header fields
> > present when the message was signed.  It is not required to include
> > all header field names and values."
>
> I've added essentially this wording.  Sorry for the confusion; it was
> definitely ambiguous.

Thanks.  This was one of the issues I had brought in the issues list.

I think what is may be important is what to do when a header is different
from a possible copy in the z= list.

I.e., for a mailing server that may alter the subject line to add the
[mailinglist_name] subject tag.

Example:  This might be the correction.

    // Hash Headers

    hash = empty;
    for each hdr in (dkim_h_list) do

      s  = mail_headers[hdr];
      sz = dkim_z_list[hdr];  // see is copy is available

      if (s != sz) {
         WHAT? INVALID?  Should they be the same?
         What can cause this? Mailing list?
      }

      if (s == "") s = sz;  // correction

      if (s != "")
         hash += hash_string(s)
      else
         WHAT? INVALID?

    end for

Make sense?

---
Hector