[ietf-dkim] draft-ietf-dkim-mailinglists-01 review request
Rolf E. Sonneveld
R.E.Sonneveld at sonnection.nl
Fri Aug 6 15:11:16 PDT 2010
Murray S. Kucherawy wrote:
> The -01 draft was briefly presented in Maastricht. We'd like to get more review of and feedback about it from people with an ideal in mind of starting a WGLC toward the end of September.
> Please take some time to review it and provide comments, even if it's just "I've read it, looks good." We need to record even that sort of thing as part of the rough consensus record before advancing.
> You MUST NOT [RFC2119] use this thread for debating the technical or political points of ADSP. Please start a different thread for that or any other tangent. It makes the author's job much harder when trying to locate feedback that needs to be applied.
> And thanks to Daniel for the quick feedback!
> NOTE WELL: This list operates according to
finally got some time to review the -01 draft. Below are my comments.
3.2: typo: "... a address..." should be "...an address..."
3.3: in the light of the discussion on message digests, I'd suggest to
add text to this paragraph about MLM's turning multiple messages from
potentially multiple senders/authors into a new message, invalidating
the DKIM signature of the original message(s).
3.3: Just a note on subject tags you may or may not wish to add: some
MLM's offer the choice of appending a postfix (as an alternative to
prepending a prefix).
3.4: "... entire entire..." should be "... entire..."
3.4: "... but this not workable..." should be "... but this is not
3.4: in addition to making the recommendation of sending periodic,
automatic mailings to the list, I would suggest to make the (implicitely
present) recommendation for an MLM, to not add header- and footer
sections, more explicit.
4. (and 5.) I would suggest to add one or two lines to the Introduction
paragraph (par. 1.2 or par 1.4, or add a par. 1.5) to explain that there
are different types of MLM's and they each are addressed in this
document, in different sections. Something along the lines of:
"In general there are, in relation to DKIM, two categories of MLMs:
participating and non-participating MLMs. As both types have their own
issues, regarding DKIM signed messages that are handled by them, they
are discussed in two different chapters (possibly a link to chapter 4
4.1 I get confused here: you write "the author is advised to be cautious
when deciding whether or not to sign the message". However, according to
par. 3.1 the author does not sign a message; that is being done by the
signer. Furthermore, if we change this phrase into "the signer is
advised to be cautious when deciding whether or not to sign the message"
then the question is: how can a signer (which is by definition not a
human being) know whether the MLM is non-participating. If the signer is
not a human being, there must be some mechanism by which the signer can
learn from the MLM that is is non-participating, but as the MLM is not
participating, it is difficult to propose a protocol between MLM and
signer to make the signer aware that the MLM is not DKIM aware :-)
The remainder of that paragraph explains things pretty well, but the
first few lines causes some confusion.
4.3 Under [ADSP]. "... Per that specification, when a message is
unsigned or the signature can no longer be verified, the verifier must
discard the message. ...". But this is only true if the author domain
publishes 'discardable'. So I suggest to change this phrase into: "...
Per that specification, when a message is unsigned or the signature can
no longer be verified, the verifier must discard the message in case the
author domain publishes an ADSP policy of discardable. ..."
5.1 Section 2: I wonder whether this paragraph is still required, in the
light of the 'reject policy' described in par. 5.5. After all, why
bother non-posting subscribers with these warnings? As soon as they
start posting, they will get a warning (i.e. a reject) when submitting
their first message and then they can change their policy or post using
another address/(sub)domain. I would suggest to remove this paragraph,
unless I'm overlooking something.
5.4 The title "Pros and Cons of Signature Removal" does not really cover
the contents of the paragraph. I would suggest "Signature Removal" as title.
5.4 I wonder whether there's any wording required here to describe what
an MLM should do in case of sending a digest. For example, MailMan
supports two types of digest, one of them being the multipart/digest
MIME type, where each message is sent as bodypart inside a mail. Should
the MLM try to verify the DKIM signature of all messages within the
digest and put the A-R for all of them in the header? And remove them
all? Presumably the answer is 'yes', but it won't hurt to describe this
5.6 At the end of page 18, beginning of page 19: should there not be
explicitely added "o 5322.From field"? As [DKIM] also _requires_ the
From to be used for the header hash.
5.6 Under "Operators of non-DKIM-aware MLMs are advised ...will be
sigend" the following remark: if a non-DKIM-aware MLM send its mail via
an MSA that performs the signing, we run the same risk as having a
DKIM-aware MLM which does not remove the original DKIM signature, don't
we? Another remark about this paragraph: shouldn't this be moved to
chapter 4 (non-DKIM aware MLM's)?
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