ietf-dkim
[Top] [All Lists]

Re: [ietf-dkim] Draft minutes...

2006-07-12 16:31:27
A few comments on my action items:

1308 (language recommending use of t=s): In the description of the t=s flag, I've added "Use of this flag is RECOMMENDED unless subdomaining is required."

DNS discussion: There's a note from Olafur suggesting that the document add "do not use wildcards." I'm not completely clear where this belongs: it can't be for _domainkey.*.example.com, so perhaps this means for *._domainkey.example.com? Or is this about policy?

1316 #1 (define plain-text): It turns out it's already defined for tag=value lists (which is what matters for us) in the ABNF for VALCHAR. I've added "INFORMATIVE IMPLEMENTATION NOTE: Although the "plain text" defined below only includes 7-bit characters, an implementation that wished to anticipate future standards would be advised to not preclude the use of UTF8-encoded text in tag=value lists."

1316 #22 (guidance on limiting trace headers): Section 5.4 now includes the text "Signers choosing to sign an existing header field that occurs more than once in the message (such as Received) MUST sign the physically last instance of that header field in the header block. Signers wishing to sign multiple instances of such a header field MUST include the header field name multiple times in the h= tag of the DKIM-Signature header field, and MUST sign such header fields in order from the bottom of the header field block to the top. The signer MAY include more instances of a header field name in h= than there are actual corresponding header fields to indicate that additional header fields of that name SHOULD NOT be added."

1317 #33 (use cases for 3rd party MTAs --- the notes have this listed as #30-#34, but I believe that is incorrect): I have added Appendix B.7 reading (sorry for the XML):

       <section
       title="SMTP Servers for Roaming Users"
       ><t
       >Roaming users may find themselves in circumstances where it
       is convenient or necessary to use an SMTP server other than
       their home server; examples are IETF conferences and many
       hotels.  In such circumstances the signature, if any, will be
       added by a party other than the user's home system.</t
       ><t
       >Ideally roaming users would connect back to their home
       server using either a VPN or a SUBMISSION server running with
       SMTP AUTHentication on port 587.  If the signing can be
       performed on the roaming user's laptop then they can sign
       before submission, although the risk of further modification
       may be high.  If neither of these are possible, these roaming
       users will not be able to send mail signed using their own
       domain key.</t
       ></section
       >

Not explicitly listed in the notes:

Section 5.4 (Determine the header fields to sign) now has the following language (again, sorry for the XML):

       The From header field MUST be signed (that is, included in
       the h= tag of the resulting DKIM-Signature header field); any
       header field defined as an Originator Field in <xref
       target="RFC2822"
       ></xref
       > section 3.6.2, Resent-From, and Resent-Sender MUST also be
       included. The signed header fields SHOULD also include the
       Subject and Date header fields as well as all MIME header
       fields. Signers SHOULD NOT sign an existing header field
       likely to be legitimately modified or removed in transit. In
       particular, <xref
       target="RFC2821"
       ></xref
       > explicitly permits modification or removal of the
       "Return-Path" header field in transit. Signers MAY include
       any other header fields present at the time of signing at the
       discretion of the signer.<list
       style="empty"
       ><t
       >INFORMATIVE OPERATIONS NOTE: The choice of which header
       fields to sign is non-obvious. One strategy is to sign all
       existing, non-repeatable header fields. An alternative
       strategy is to sign only header fields that are likely to be
       displayed to or otherwise be likely to affect the processing
       of the message at the receiver. A third strategy is to sign
       only "well known" headers. Note that verifiers may treat
       unsigned header fields with extreme skepticism, including
       refusing to display them to the end user.</t
       ></list
       >

eric
_______________________________________________
NOTE WELL: This list operates according to http://mipassoc.org/dkim/ietf-list-rules.html